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Clark University
1889-1899
Beeennial Celebration
^^t?
Worcester, Mass.
Printed for the University
1899
my 390/
Copyright, 1899,
Bt claek university.
WorfaoDli 3,3rcss
J. S. Gushing & Co. — Berwick & Smith
Norwood, JIasg. U. S. A.
1^
/ 377
PREFACE.
This volume is intended not only to commemorate the Decen-
nial Anniversary of Clark University, but also to make the Public
acquainted with its aims and ideals, and with the character, scope,
and amount of the work it has already done. Ever since it
opened its doors to students it has confined itself to truly post-
graduate work in a few departments, and has admitted such
students only as gave promise of the ability not only to pursue
the courses here offered with advantage to themselves, but to
benefit the world by advancing science along the lines here repre-
sented. It has thus taken a distinct position as a training school
for college professors and scientific investigators. Such a policy
is conducive neither to large numbers of students nor to popular
appreciation. But, small as the university is and few as are its
departments, it takes great satisfaction in pointing to this volume
as, in some sense, a record of its work and its methods. The
list of titles of the publications of its past and present members
is a witness of the quality and quantity of what it has accom-
plished. We believe that Clark University, opening, as it did,
at the beginning of a new university epoch in this country, has
had some special influence in suggesting new lines of scientific
research.
The five foreign professors who took part in the Decennial
Celebration were selected as the most eminent available scientific
men in their respective lines in Europe ; this was the first visit of
each to America, and four of them came here solely for this anni-
iv Preface.
versary. Their lectures are here reproduced in exteiiso and have
not been published elsewhere. The lectures of Professors Picard
and Boltzraann are given in the languages in which they were
delivered, and those of Professors Ramon y Cajal, Mosso, and
Forel in translations made by members of the Faculty and revised
by representatives of the departments to which they severally
belong. For these laborious services the editors desire to extend
their very particular thanks to the individuals who have rendered
them.
The reports of departments were prepared especially for this
occasion, and include not only an account of the work actually
done during the decade, but also a statement by the officer in
charge of each department of its aims and ideals and the lines
along which it hopes to advance. The responsibility for the
content and form of each report rests with the individual in
whose name it is published ; all modifications by the editors hav-
ing been made in the form of suggestions to the writers and
adopted only with their consent. It is perhaps unnecessary to
say that no attempt has been made to secure uniformity in the
various articles, excepting in the titles and in minor details of
arrangement.
The editors extend their hearty thanks to the authors of the
several portions of the volume for their cordial cooperation and
for the friendly spirit in which suggestions have been received,
and to all members of the Faculty for assistance in reading the
proof-sheets.
WILLIAM E. STORY,
LOUIS N. WILSON,
Editors.
TABLE OF CONTEK'TS
PAGE
HISTORICAL SKETCH 1
THE DECENNIAL CELEBRATION 13
EXTRACTS FROM CONGRATULATORY LETTERS ... 25
DECENNIAL ADDRESS 45
By G. Stanley Hall, President of the University.
EEPORTS OF DEPARTMENTS
THE DEPARTMENT OF MATHEMATICS 61
By William Edward Story.
THE DEPARTMENT OF PHYSICS 85
By Arthur Gordon Webster.
THE DEPARTMENT OF BIOLOGY 99
By Clifton F. Hodge.
THE DEPARTMENT OF PSYCHOLOGY 119
General Psychology 122
By Edmund C. Sanford.
Psycho-Pathology 144
By Adolf Meyer.
Anthropology 148
By Alexander F. Chamberlain.
Pedagogy 161
By William H. Burnham.
Philosophy 177
By G. Stanley Hall.
THE LIBRARY 187
By Louis N. Wilson.
REPORT OF THE TREASURER ....... 199
By Thomas H. Gage.
V
vi Table of Contents
SCIENTIFIC LECTUEES
DELIVERED IN CONNECTION WITH THE
DECENNIAL CELEBRATION
PAGE
JSmile Picard, Professor of Mathematics at the University of Paris.
1. Sur I'Extension de quelques Notions Mathematiques, et en parti-
culier de I'Idee de Fonction depuis un Siecle .... 207
2. Quelques Vues Generales sur la Theorie des ifiquations Differentielles 224
3. Sur la Theorie des Fonctions Analytiques et sur quelques Fonc-
tions Speciales 241
LuDWiG BoLTZMANx, Professor of TJieoretical Physics at the University of
Vienna.
Ueber die Grundprineipien und Grundgleichungen der Mechanik.
(Four Lectures) 261
Santiago Ramon y Cajal, Professor of Histology and Rector of the
University of Madrid.
1. Comparative Study of the Sensory Areas of the Human Cortex . 311
2. Layer of the Large Stellate Cells 336
3. The Sensori-Motor Cortex 360
Angelo Mosso, Professor of Physiology and Rector of the University of
Turin.
1. Psychic Processes and Muscular Exercise 383
2. The Mechanism of the Emotions 396
August Forel, Late Professor of Psychiatry at the University of Ziirich
and Director of the Burghdlzli Asylum.
1. Hypnotism and Cerebral Activity 409
2. A Sketch of the Biology of Ants 433
DEGREES CONFERRED, 1889-1899 453
TITLES OF PUBLISHED PAPERS 459
SPECIAL STUDENTS 565
HISTORICAL SKETCH.
HISTOEICAL SKETCH.
/ (2? (i* 3 (fi
Clark University was founded by the munificence of Jonas G. Clark,
a native of Worcester County, wliose plans, conceived more than twenty
years before, had gradually grown with his fortune. His affairs had been
so arranged as to allow long intervals for travel and study. During
eight years thus spent, the leading foreign institutions of learning, old
and new, were visited, and their records gathered and read. These
studies centred about the means by which the highest culture of one
generation is best transmitted to the ablest youths of the next, and
especially about the external conditions most favorable for increasing
the sum of human knowledge. To the improvement of these means and
the enlargement of these conditions, the new University was devoted.
It was the strong and express desire of the founder that the highest
possible academic standards be here forever maintained ; that special
opportunities and inducements be offered to research ; that to tliis end the
K instructors be not overburdened with teaching and examinations ; that
^ all available experience, both of older countries and our own, be freely
utilized ; and that new measures, and even innovations, if really helpful
\^ to the highest needs of modern science and culture, be no less freely
VJ adopted ; in fine, that the great opportunities of a new foundation in this
land and age be diligently explored and improved.
He chose Worcester as the seat of the new foundation after mature
deliberation, — first.
Because its location is central among the best colleges of the East, and
by supplementing rather than duplicating their work, he hoped to ad-
vance all their interests and to secure their good will and active support,
that together they might take further steps in the development of
superior education in New England ; and secondly,
Because he believed the culture of this city would insure that en-
lightened public opinion indispensable in maintaining these educational
2 Historical Sketch.
standards at their highest, and that its wealth would insure the perpetual
increase of revenue required by the rapid progress of science.
As the first positive step toward the realization of these long-formed
plans, Mr. Clark invited the following gentlemen to constitute with
himself a Board of Trustees : — .
Stephen- Salisbury, A.B., Harvard, 1856; Universities of Paris and Berlin,
1856-58; LL.B., Harvard, 1861; President Antiquarian Society since 1887;
State Senator, 1892-95.
Charles Devens, A.B., Harvard, 1838 ; LL.B., Harvard, 1840 ; Major-General,
1863 ; Associate Justice of the Massachusetts Superior Court, 1867-73 ;
Associate Justice of the Massachusetts Supreme Judicial Court, 1873-77,
and again, 1881-91 ; Attorney-General of the United States, 1877-81 ;
LL.D., Columbia and Harvard, 1877; Died January 7, 1891.
George F. Hoar, A.B., Harvard, 1846 ; LL.B., Harvard, 1849 ; United States
House of Eepresentatives, 1869-77 ; Member Electoral Commission, 1876 ;
United States Senate since 1877 ; Chairman of Judiciary Committee, 1891 — ;
LL.D., William and Mary, Amherst, Harvard, and Yale.
William W. Kice, A.B., Bowdoin, 1846; admitted to Bar, 1854; United States
House of Eepresentatives, 1876-86 ; LL.D., Bowdoin, 1886. Died March 1,
1896.
Joseph Sargekt, A.B., Harvard, 1834 ; M.D., Harvard, 1837 ; London and Paris
Hospitals, 1838-40. Died October 13, 1888.
JoHK D. WASHBUR^^, A.B., Harvard, 1853; LL.B., Harvard, 1856; Eepresenta-
tive, 1876-79 ; State Senate, 1884 ; United States Minister to Switzerland,
1889-92.
Frank P. Goulding, A.B., Dartmouth, 1863; Harvard Law School, 1866;
City Solicitor, 1881-93.
George Swan, A.B., Amherst, 1847 ; admitted to Bar, 1848 ; Member of
Worcester School Board, 1879-90 ; Chairman of High School Committee,
1887-90.
The following gentlemen have been added to the Board since to fill
vacancies caused by death. In place of Dr. Sargent : —
Edward Cowles, A.B., Dartmouth, 1859; M.D., Dartmouth, 1862, and Col-
lege of Physicians and Surgeons, N. Y., 1863 ; Assistant Surgeon, U. S. A.,
1863-72 ; Eesident Physician and Superintendent Boston City Hospital,
1872-79 ; Medical Superintendent McLean Asylum smce 1879 ; Professor of
Mental Diseases, Dartmouth IMedical School, since 1885 ; Clinical Instructor
in Mental Diseases, Harvard Medical School, since 1888.
In place of General Devens:
Thomas H. Gage, M.D., Harvard, 1852; President Massachusetts Medical
Society, 1886-88.
Historical Sketch. 3
On petition of this Board, the Legislature passed the following
Act of Incorporation, Chapter 133.
commonwealth of massachusetts, in the year one thousand eight hun-
dred and eighty-seven. an act to incorporate the trustees of
clark university in worcester.
Be it enacted by the Senate and House of Kepresentatives in General Court
assembled, and by authority of the same, as follows : —
Section 1. Jonas G. Clark, Stephen Salisbury, Charles Devens, George F.
Hoar, William W. Rice, Joseph Sargent, John D. Washburn, Frank P. Gould-
ing and George Swan, all of the city of Worcester, in the Commonwealth of
Massachusetts, and their successors, are hereby made a corporation by the name
of the Trustees of Clark University, to be located in said Worcester, for the
purpose of establishing and maintaining in said city of Worcester an institu-
tion for the promotion of education and investigation in science, literature and
art, to be called Clark University.
Section 2. Said corporation may receive and hold real or personal estate
by gift, grant, devise, bequest or otherwise, for the purpose aforesaid, and shall
have all the rights, privileges, immunities, and powers, including the conferring
of degrees, which similar incorporated institutions have in this Commonwealth.
Section 3. Said corporation shall have the power to organize said Univer-
sity in all its departments, to manage and control the same, to appoint its
officers, who shall not be members of said corporation, and to fix their com-
pensation and their tenure of office ; and said corporation may provide for the
appointment of an advisory board and for the election by the Alumni of said
University to fill any vacancies in said board.
Section 4. The number of members of said corporation shall not be less
than seven nor more than nine, and any vacancy therein may be filled by the
remaining members at a meeting duly called and notified therefor ; and when any
member thereof shall, by reason of infirmity or otherwise, become incapable, in
the judgment of the remaining members, of discharging the duties of his office,
or shall neglect or refuse to perform the same, he may be removed and another
be elected to fill his place, by the remaining members, at a meeting duly called
and notified for that purpose.
Section 5. This Act shall take effect upon its passage.
House of Eepresentatives, March 30, 1887, Passed to be Enacted.
Charles J. Noyes, Speaker.
Senate, March 31, 1887, Passed to be Enacted.
Halsey J. BoARDMAN, President.
During the previous five years, Mr. Clark had gradually acquired a
tract of land, comprising over eight acres, located on Main Street, about
4 Historical Sketch.
a mile from the heart of the city, with additional tracts near by. This
land has considerable elevation above that part of the city, is a watershed
sloping to the southeast, insuring sanitary excellence and a wide and
picturesque view. A park reservation of about 25 acres, directly oppo-
site, has been set apart by the city, and named University Park.
Plans for a main building were submitted to the Board by Mr. Clark,
which were approved, and its erection was at once begun. The corner-
stone was laid with impressive ceremonies, October 22, 1887. This build-
ing is plain, substantial, and well appointed, 204 x 114 feet, four stories high
and five in the centre, with superior facilities for heating, lighting, and
ventilation, and has been constructed of brick and granite, and finished
throughout in oak. On the whole it is a model of stability and solid work-
manship. It contains a total of 90 rooms, and in its tower is a clock with
three six-foot illuminated dials, which was presented by the citizens of
Worcester. The elevations and ground plan are published, and the heat-
ing, lighting, ventilation, walls, floors, etc., etc., are described in detail
in the Third Official Announcement.
On April 3, 1888, G. Stanley Hall, then a professor at Johns
Hopkins University, was invited to the presidency. The ofiicial letter
conveying the invitation to the president contained the following well-con-
sidered and significant expression of the spirit animating the trustees : —
" They desire to impose on you no trammels ; they have no friends for whom
they wish to provide at the expense of the interests of the institution ; no pet
theories to press upon you in derogation of your judgment ; no sectarian tests
to apply ; no guarantees to require, save such as are implied by your acceptance
of this trust. Their single desire is to fit men for the highest duties of life,
and to that end, that this institution, in whatever branches of sound learning
it may find itseK engaged, may be a leader and a light."
This invitation was accepted May 1, and the president was at once
granted one year's leave of absence, with full salary, to visit universities
in Europe. This year was diligently improved in gathering educational
literature and collecting information and advice from leading authorities.
Many reports based upon this work have already been made in the Peda-
gogical Seminary and more are in course of preparation.
During the absence of the president a Chemical Laboratory was begun.
This building in its main body has three stories, in its eastern wing four,
in its southwestern two. It contains 68 rooms. The outer walls are
2 feet in thickness and the partition walls from 12 to 16 inches. All par-
Historical Sketch. 5
titions are of brick, so that the building is nearly fireproof. The two
large laboratories are 24 x 58 feet and 22 feet high. This building is
also described with plans in the Third Official Annou7icement.
The opening exercises were held in a hall of the University, seating
1500 people, on Wednesday, October 2, 1889. The late General Charles
Devens presided, and made an opening address. Addresses were made
by Senator George F. Hoar and the president. The founder of the
University stated his purpose as follows : —
" When we first entered upon our work it was with a well-defined plan and
purpose, in which plan and purpose we have steadily persevered, turning
neither to the right nor to the left. We have wrought upon no vague concep-
tions nor suffered ourselves to be borne upon the fluctuating and unstable
current of public opinion or public suggestions. We started upon our career
with the determinate view of giving to the public all the benefits and advan-
tages of a university, comprehending full well what that implies, and feeling
the full force of the general understanding, that a university must, to a large
degree, be a creation of time and experience. We have, however, boldly
assumed as the foundation of our institution the principles, the tests, and the
responsibilities of universities as they are everywhere recognized — but with-
out making any claim for the prestige or flavor which age imparts to all things.
It has therefore been our purpose to lay our foundation broad and strong and
deep. In this we must necessarily lack the simple element of years. We
have what we believe to be more valuable — the vast storehouse of the knowl-
edge and learning which has been accumulating for the centuries that have
gone before us, availing ourselves of the privilege of drawing from this source,
open to all alike. We propose to go on to further and higher achievements.
We propose to put into the hands of those who are members of the University,
engaged in its several departments, every facility which money can command
— to the extent of our ability — in the way of apparatus and appliances that
can in any way promote our object in this direction. To our present depart-
ments we propose to add others from time to time, as our means shall warrant
and the exigencies of the University shall seem to demand, always taking those
first whose domain lies nearest to those already established, until the full
scope and purpose of the University shall have been accomplished.
" These benefits and advantages thus briefly outlined, we propose placing at
the service of those who from time to time seek, in good faith and honesty of
purpose, to pursue the study of science in its purity, and to engage in scientific
research and investigation — to such they are offered as far as possible free
from all trammels and hindrances, without any religious, political, or social
tests. All that will be required of any applicant will be evidence, disclosed
by examinations or otherwise, that his attainments are such as to qualify him
for the position that he seeks."
6 Historical Sketch.
After careful consideration it was decided to begin with graduate
work only and in the following five departments :
I. Mathematics.
II, Physics, Experimental and Theoretical.
III. Chemistry, Organic, Inorganic, Physical, and Crystallography.
IV. Biology, including Anatomy, Physiology, and Paleontology.
V. Psychology, including Neurology, Anthropology, and Education.
Mathematics is sometimes called the queen of all the sciences. As
the latter become exact, they approximate it, and are fructified by its
spirit and its methods. Its antiquity, its disciplinary value, its rapid
and recent development, make it obviously indispensable. Physics is
the field of the most immediate application of mathematics, and deals
with the fundamental forces of the material universe, — heat, sound,
light, electricity, — and the underlying problems of form and motion
generally, with their vast field of application in such sciences as astronomy
and dynamic geology. Chemistry, with its great and sudden development,
revealino- marvellous order and harmony in the constitution of matter,
is rapidly extending its dominion over industrial processes. Biology,
which seeks to fathom the laws of life, death, reproduction, and disease,
that underlies all the medical sciences, in its broader aspects has taught
man in recent decades far more concerning his origin and nature than all
that was known before. Psychology, or the study of man's faculties
and their education, is a new field into which all the sciences are bringing
so many of their richest and best ideas, which is now so full of promise
for the life of man.
A sub-department of Education was established in 1892, and the
department of Chemistry was temporarily discontinued in 1894.
To express more explicitly the character and policy of the institution,
the Trustees voted to approve and publish the following statement : —
" As the work of the University increases, its settled policy shall be always
to first strengthen departments already established, until they are as thorough,
as advanced, as special, and as efficient as possible, before proceeding to the
establishment of new ones.
"When this is done and new departments are established, those shall always
be chosen first which are scientifically most closely related to departments
already established ; that the body of sciences here represented may be kept
vigorous and compact, and that the strength of the University may always
rest, not upon the number of subjects, nor the breadth or length of its cur-
riculum, but upon its thoroughness and its unity.
Historical Sketch. 7
" This shall in no wise hinder the establishment, by other donors than the
founder, of other and more independent departments if approved by the
Trustees.
" While ability in teaching shall be held of great importance, the leading
consideration in all engagements, reappointments, and promotions shall be the
quality and quantity of successful investigation."
By thus limiting the work of the University in the beginning to
five departments, it appeals only to advanced men who desire to specialize
in one or more of these fundamental sciences, leaving college students
who require a larger range of studies, as well as those who desire to
devote themselves to language and literature, historical, technical, or pro-
fessional studies, to go elsewhere. Hence our work must be post-
graduate. This requires the best professors and apparatus, more books
and journals, and necessitates a system of fellowships, scholarships, and
provisions for original research. It thus becomes a training-school for
professors. This is the most expensive of all educational work, seeks
the fewest but the best men from the widest area, and to succeed must
be helpful in elevating the academic standards of the country to a higher
plane. It requires the highest degree of wisdom and foresight on the
part of the Founder and the Trustees, and possibly some sacrifices of
local sjrmpathy and support at first, till the nature of the work is well
understood. It requires the greatest effort and devotion to work on
the part of the Faculty and students. But the cause is itself an inspira-
tion. It appeals to the future, the country, and to the world, and seeks
quality more than numbers. It is in the current of all the best tenden-
cies in the best lands, and is now the ideal of perhaps every eminent
man of science everywhere. The inauguration and steady maintenance
of this clear and simple policy gives the University a reason for being,
and a distinct individuality it could not otherwise have, and also a real
leadership in this epoch of awakening and transition, which is the golden
time of opportunity for new institutions, and brings them to the front.
Such a period as the present gives the latter even greater relative influ-
ence and prominence than would be possible in periods of less public
interest in education. New institutions can and should lead, set new
fashions, and be the first upon the higher planes. Older institutions
are retarded by conservatism and must advance more slowly, but
when they move they carry great momentum. This condition makes
the present a moment of perhaps unprecedented opportunity, which
8 Historical Sketch,
has been long looked for and long delayed, and whicli renders
both funds and labor in this field more precious than they have
been, or will be when it is past. We may all be content if our Uni-
versity can transmit to future generations by means of its organization,
plan, and methods the best and highest educational tendencies and move-
ments now stirring the souls of the best men of the world, and uniting
men of all lands, races, creeds, and stations in a larger if not also a deeper
consensus of belief than history has ever known before.
Our University does not draw its chief earnings from, or do most of
its teaching for, undergraduates, and our so-called graduate students do
not take undergraduate courses. This makes the proportion of expendi-
ture to income very high here, and indeed we can admit and do justice
to but comparatively few students. Most of those who come here have
spent one or more years after graduation in teaching, or in study in
Europe or elsewhere. Most of those who have been members here have
already obtained professorships or other academic positions elsewhere.
The proportion of such is hardly excelled by the Ecole Normale of Paris,
the special function of which is to train professors from other collegiate
institutions. Every student who obtains original results is exjDected to
present them in the form of lectures to his department, and thus to
acquire experience in teaching under criticism. The work of the educa-
tional department deals with problems and history of higher educational
institutions, and is adaj^ted to all the body of fellows and scholars, and
seeks to increase the efficiency of every man both as a teacher of his own
specialty and in general helpfulness to the institution with which he is to
be connected.
Since the opening of the University not less than five hundred books,
memoirs, theses, or articles ^ have been published by members of the Uni-
versity, which attempt to make additions to the sum of human knowledge.
These contributions are of very different orders of value, but together they
constitute a body of knowledge in which the institution takes special pride.
Every member of the University is expected to make at least one long and
serious effort of this kind. Indeed, had its publications no value as contri-
butions to knowledge, its educational value is the highest for mature men.
Such effort gets minds into independent action, gives a sense of authority
and of true mental freedom, which no amount of acquisition can bring. It
brings out new powers of mind and of will, and, while one of the chief
1 A list of these publications will be found at the end of this volume.
Historical Sketch. 9
marks by which true University work is distinguished from that of lower
grades, is in the line of all present tendencies to place doing above know-
ing from the kindergarten up. Work that is published enlarges the
sphere of interests of the author, subjects him to the higher test of being
judged by his peers elsewhere, and brings in the potent and salutary
stimulus of wider competition. This baptism of ink has often marked a
new birth of ideals and ability in young men. Modern as distinct from
earlier culture culminates in the man-making training of will and judg-
ment thus given. Such work, too, gives teaching a new power and zest.
Instruction to a fit few by an investigator who stands on the frontier and
has once felt the light and heat in which discovery is wrought out is
inspiring, and is very different from information imparted at lower levels
by teachers further removed from the work of discovery and creation.
Clark University is exclusively what is called in Europe a Philo-
sophical Faculty, or a part of one so far as yet developed, devoted to a
group of the pure sciences which underlie technology and medicine, but
does not yet apply its work to these professional fields. These or a
college course could be added with relatively less expense. Our
method has brought us face to face with many new problems. Our
efforts at solving some of these are described in the department reports
which follow. Like all new institutions, we have not entirely escaped
trials, but we trust we have learned their lesson, and shall be the better
and stronger for them. Instead of dispersing our energies in university
extensions, we have followed the opposite course of university concentra-
tion, like the Ecole Pratique of France. Accepting the plain lesson of
history that the best educational influences work from above downward,
that universities create the material of culture, while lower institutions
are the canals for its distribution, we have sought aid for the latter work
by an educational sub-department and summer school. We are not like
the Smithsonian Institute, the Naples school, the Meichsanstalt, academies
of science, etc., devoted solely to research, but have to make our lectures
more condensed and fewer than usual, because addressed to advanced
men, and to devise ways of making seminary and laboratory, two of the
noblest words in the vocabulary of higher education, more effective. We
have tried to effect systematic exchanges with foreign institutions, — and
our library has profited largely from this source, — and have sought by
all the above means to aid in giving to universities and to professors the
position due them in a time when sciences have come to underlie all the
10 Historical Sketch.
arts of peace and war, and when the world, in all its activities, industry
and trade, professions, legislation, is coming to be more and more con-
trolled by experts, thus trained to the frontier of their specialties.
The degree of Doctor of Philosophy has been conferred upon can-
didates, whose names, together with the dates of their final examinations
and the subjects of their dissertations, are given later in this volume.
Other historical facts are given in the President's Address at the
Decennial Celebration.
REQUIREMENTS FOR THE DEGREE OF DOCTOR OF
PHILOSOPHY.
At least two years, and in most cases three years, of graduate work
will be necessary for this degree. Examinations for it, however, may
be taken at any time during the academic year when, in the judgment
of the University authorities, the candidate is prepared. A prearranged
period of serious work at the University itself is indispensable.
For this degree the first requirement is a dissertation upon an
approved subject, to which it must be an original contribution of value.
To this capital importance is attached. It must be reported on in
writing by the chief instructor before the examination, printed at the
expense of the candidate, and at least one hundred copies given to
the University. In case, however, of dissertations of very unusual
length, or containing very expensive plates, the Faculty shall have
power, at the request of the candidate, to reduce this number of presen-
tation copies to fifty.
Such formal or informal tests as the Faculty shall determine, shall
mark the acceptance of each student or fellow as a candidate for this
degree. One object of this preliminary test shall be to insure a good
reading knowledge of French and German. Such formal candidature
shall precede by at least one academic year the examination itself.
(See special rules below.)
The fee for the doctor's degree is $25, and in every case it must
be paid and the presentation copies of the dissertation must be in the
hands of the Librarian before the diploma is given. In exceptional
cases, however, and by special action of the Faculty, the ceremony
of promotion may precede the presentation of the printed copies of
Historical Sketch, 11
the dissertation. The latter, however, must always precede the actual
presentation of the diploma.
An oral but not a written examination is required upon at least
one minor subject in addition to the major, before an examination
jury composed of at least four members, including the head of the
department and the President of the University, who is authorized
to invite any person from within or without the University to be
present and to ask questions. The jury shall report the results of
the examination to the Faculty, which, if it is also satisfied, may
recommend the candidate for the degree.
For the bestowal of this degree, the approbation of the Board of
Trustees must in each case be obtained. They desire that the standard
of requirements for it be kept the highest practicable, that it be reserved
for men of superior ability and attainment only, and that its value
here be never suffered to depreciate.
It is to the needs of these students that the lectures, seminaries,
laboratories, collections of books, apparatus, etc., are specially shaped,
and no pains will be spared to afford them every needed stimulus
and opportunity. It is for them that the Fellowships and Scholarships
are primarily intended, although any of these honors may be awarded
to others.
SPECIAL RULES.
I. Residence. — No candidate shall receive the degree of Doctor of
Philosophy without at least one year's previous residence.
II. Candidature for the Doctors Degree. — Every applicant for the
doctor's degree shall fill out before October 15th the regular appli-
cation blank provided at the office. This schedule shall be submitted
to the head of the department and the instructor in the major subject.
Before affixing their signatures they shall satisfy themselves, in such
manner as they may desire, as to the fitness of the applicant.
III. When countersigned, this schedule shall be filed with the
President, who will appoint an examiner to serve with a representative
of the major subject as a committee to determine the proficiency of
the applicant in French and German.
IV. In case of a favorable report by this committee the applicant
shall be a regular candidate for the degree.
V. Candidates complying with all preliminary conditions, including
12 Historical Sketch.
the examinations in French and German, before November 1st, will
be allowed to proceed to the doctor's examination at any time between
May 15th following and the end of the academic year.
VI. Dissertation. — The dissertation must be presented to the in-
structor under whose direction it was before written, and reported upon
by him before the final examination. In every case the dissertation shall
be laid before the jury of examination, at the time of examination, in form
suitable for publication. This provision shall not, however, preclude the
making of such minor changes later as the chief instructor may approve.
VII. The dissertation shall be printed at the expense of the can-
didate, and the required copies deposited with the Librarian within
one calendar year from the 1st of October following the examination.
The candidate alone will be held responsible for the fulfilment of these
conditions.
VIII. The favorable report of the chief instructor, filed in writing
with the Clerk of the University, shall be a sufficient imprimatur or
authorization for printing as a dissertation. The printed copies shall
bear upon the cover the statement of approval in the following words,
over the name of the chief instructor : —
A Dissertation submitted to the Faculty of Clark University, Wor-
cester, Mass., in partial fulfilment of the requirements for the degree
of Doctor of Philosophy, and accepted on the recommendation of
(name of the chief instructor).
IX. Examinations for the Doctor'' s Degree. — The examinations for
the doctor's degree may be held at any time during the academic
year, provided that at least one academic year has elapsed since the
completion of the preliminaries of candidature, except in the case of
fulfilment of these conditions between the beginning of any academic
year and November 1st of that year, to which case Rule V. applies.
The examinations shall be held at such hours and places as the President
may appoint.
X. Examinations may also be held during the regular vacations
of the University, but for these an additional fee of five dollars to
each examiner, and the reasonable travelling expenses of any examiners
who are out of town, all payable in advance, will be required.
XI. All these special rules shall go into force immediately as far
as practicable, and shall govern all applicants for degrees in the academic
year 1899-1900.
THE DECENNIAL CELEBEATION.
The work of Clark University is so technical and special that it is
necessarily more or less withdrawn from popular interest. It has no
commencements, and comes in very little contact with the public or the
press in Worcester, or indeed with collegiate institutions in other parts of
the country. This is a disadvantage so far as local or general public
interest in its work is concerned, but the fact that it does not exercise
many of the usual functions of a college is also a distinct advantage to its
scientific work. The close of the tenth year of its existence presented an
opportunity to bring before the public, in a simple way, befitting at once
its size and its quality, a presentation of the work it has accomplished in
the past and of its hopes and needs for the future. Early last winter the
President began to consider plans of marking this anniversary, and, with
the efficient aid of the Faculty, they gradually took defuiite shape. A
personal appeal was then made to a number of public-spirited and wealthy
citizens of Worcester, and the scheme was rendered feasible by the gen-
erosity of the following gentlemen, who donated the sums affixed to their
names : —
Mr. Stephen Salisbury, f 1000
Mr. Philip W. Moen, 500
Mr. Thomas H. Dodge, 200
Mr. Edward D. Thayer, Jr., 200
Mr. Charles S. Barton, 100
Mr. John H. Goes, 100
Mr. Andrew H. Green, 100
Mr. Arthur M. Stone, 100
John 0. Marble, M.D., 50
Mr. C. Henry Hutchins, $500
Mr. William E. Rice, 500
Mr. Orlando W. Norcross, 200
Mr. Matthew J. Whittall, 150
Mr. A. Swan Brown, 100
Mr. Loring Goes, 100
Mr. James Logan, 100
Mr. Joseph H. Walker, 100
Mr. Frederick L. Goes, 25
Gharles L. Nichols, M.D., $25.
13
14 Decennial
It was decided that the close of the tenth academic year should be
celebrated (1) by courses of lectures delivered by distinguished foreign
scientific men, (2) by public exercises, and (3) by an evening reception.
A conference was then held concerning the most prominent leaders in
Europe in branches especially cultivated at the University, and after some
correspondence the following persons were invited to give from two to
four lectures each : —
Emile Picard, Professor of Mathematics at the University of Paris.
LuDwiG BoLTZMANN, Profcssor of Theoretical Physics at the University of
Vienna.
Angelo Mosso, Professor of Physiology and Kector of the University of Turin.
Santiago Ramon y Cajal, Professor of Histology and Eector of the Univer-
sity of Madrid.
August Forel, late Professor of Psychiatry at the University of Zurich and
Director of the Burgholzli Asylum.
Under the direction of a committee consisting of Assistant Professor
A. G. Webster and Professor W. E. Story, the following forms of
invitation to the various parts of the programme were prepared: —
Celebration. 15
^^^
/ '•'
:^^^:^^^^^=:^^^^^^.
16
Decennial
(Z/^€- ij%e(U^€^n^^j Cy'U4-4£^^d^^ t^^n-c^ iyiyCMf -a^
<)y^
^tea/a>& vt^U^.
Celebration. 17
18 Decennial
The invitations to the lectures were sent to such persons as were con-
sidered to be particularly interested in the subjects in question, of whom
over one hundred accepted. Many declinations were inevitable and
expected, owing to the unfavorable season of the year and, perhaps in
part, to the somewhat too short notice given. The lecturers all arrived
in due season, and were entertained as follows : —
Professor Emile Picard, by Professor W. E. Story.
Professor Ludwig Boltzmann, by Assistant Professor A. G. Webster.
Professor Angelo Mosso, by President G. Stanley Hall.
Professor S. Ramon y Cajal, by Hon. Stephen Salisbury.
Professor August Forel, by Dr. Adolf Meyer.
The lectures were held in the large lecture-room on the first floor, and
were well attended. Professors Picard and Cajal lectured in French, and
Professors Boltzmann, Mosso, and Forel in German. Their lectures are
printed in full elsewhere in this volume.
Many social functions occurred during the week ending July 8. On
Wednesday evening. Professor Story received informally the attendants
on the lectures of Professors Picard and Boltzmann ; on Thursday evening
President Hall gave a reception to all the visitors ; and on Friday after-
noon and evening the whole company was entertained by Hon. Stephen
Salisbury at the Quinsigamond Boat Club house.
The second part of the celebration occurred on Monday morning,
July 10, beginning at 10.30, in the University. The professors had
adopted academic costume, and many distinguished guests were seated
upon the platform. The exercises opened with prayer by the Rev. Alex-
ander H. Vinton, Rector of All Saints' Church.
A few extracts from congratulatory letters were read by Professor
Story, which are printed elsewhere in this volume. Brief congratulatory
addresses were made by President Faunce, of Brown University, repre-
senting the New England college presidents ; and Professor Bowditch of
the Harvard Medical School, representing the higher scientific institutions
of the state.
President Faunce said : —
" I count it a very happy fact that the first occasion on which I am to
officially speak, representing Brown University, is at this anniversary at
Clark University. I bring you to-day greetings from an institution of the
higher learning founded in 1764 to a university founded in 1887. It is
Celebration, 19
safe to say that Clark University has done more to widen the confines of
human knowledge than any other American college in one hundred and
fifty years.
" When Professor J. P. Cooke, of Harvard, applied to the Faculty for
chemicals and apparatus for experiment, he was told he must secure the
materials at his own expense, and that he must be responsible for any
explosions or damage in consequence of his experiments. From that day
to this is a long step. Our method of applying nature has been trans-
formed within a very few years. The distance between Achilles' coach
and the English stage-coach is not the same as that between the stage-
coach and the Empire State express. The difference between the Phceni-
cian galleys and the Bon Homme Richard is not the difference between
the Bon Homme Richard and the modern battleship. The little world of
Shakespeare has become one vast universe of learning, and the field has
broadened almost infinitely in all directions, and the goal is the far-off
divine event toward which the whole creation moves.
"In this movement of scholarship the enrichment of one institution
is the enrichment of all, the enfeeblement of one is the enfeeblement of
all. You have received at this celebration, almost Spartan-like in its sim-
plicity, the congratulations not alone of America, but of Berlin and
Munich and Vienna, because your advance and success is the advance
of all. Only geographically and superficially are the leaders of modern
scholarship divided, and so we congratulate you, not because you have
duplicated existing plants, but that you have filled a place hitherto
unfilled and have broken new ground.
" Here among all the institutions of learning you have not detracted
from the success of other institutions, you have placed fresh laurels on the
heads of each. All of us feel a warm interest and admiration for this
University because of the simple, quiet, and noble work done within these
walls."
Dr. Bowditch said that he was quite unprepared to say much, and he
thought it just as well, for he belonged, in the words of Dr. Holmes, to
the "silent profession." He paid a tribute to the felicitous speech of
Dr. Faunce, which left him little to say. Dr. Bowditch spoke of the
great work in scientific research being conducted by the institution, and,
after some wishes for its prosperity, congratulated the youngest college
in the name of the oldest college in Massachusetts.
20 Decennial
Then followed the address by President Hall, printed elsewhere in this
volume.
The honorary degree of Doctor of Laws, honoris causd, was then con-
ferred, for the first time, upon the five foreign professors in the following
terms : —
" By virtue of the authority vested by the Commonwealth of Massachu-
setts in the Board of Trustees of Clark University, and by them dele-
gated to me, I now create you Doctor of Laws, ho7ioris causd, and by this
token [presenting diploma] invest you with all the dignities thereunto
appertaining." Brief responses were made, of which translations follow.
LUDWIG BOLTZMANN.
The problem of science is a twofold one : first, to advance our knowledge
of nature independently of any practical application ; and second, to make
practical applications of the knowledge gained. Although to a superficial
observer it may seem that the latter is of greater importance, the develop-
ment of humanity has shown in the most convincing way that the first
kind of activity is not only of paramount importance, but that the leading
role belongs to it. In fact, it is only thanks to the pioneers of science
who, laying aside all practical applications, penetrate deeper and deeper
into the essence and arrangement of the forces of nature, that humanity
has obtained that sway over the laws of nature which makes possible the
present practical achievements.
The German universities have devoted themselves at all times to the
nurture of pure science apart from its practical applications, although but
one of the four university faculties is consecrated to it, and that one not
entirely. It must be considered as a good omen, therefore, that here in
America, which is usually taken to be the land of practical men, the ideal
of a place entirely consecrated to the service of pure science, unattainable
in Germany, has found its realization, so that I, who am body and soul a
German professor, deem it a great honor to have conferred on me in this
place, the greatest distinction which the University can grant. While
desiring Clark University to flourish and thrive in the intimate conviction
that the whole scientific world is interested in her prosperity, I express
my thanks to the President and all its members for the high honor
bestowed upon me to-day.
Celebration. 21
Santiago Ramon y Cajal.
I OFFER my most cordial thanks to Clark University for the honorable
distinction she has bestowed upon me in spite of my small deserts by
granting to me the degree of doctor of laws by this learned body, the
remembrance of which will never fade from my memory. This honor
I deem to be the prize of the greatest value which my modest researches
have procured for me, and the one which will encourage me most in my
worship of the laboratory tasks and of the study of nature. This
honorary distinction, as well as the invitation which Clark University
condescended to make me to take part in the conferences for solemnizing
the tenth anniversary of its foundation, shows once more that the men of
science know of no frontiers, and that they form a universal family, whose
solidarity and fellow-feeling place them high above the wrangle of mate-
rial interests and selfish struggles of nationalities.
It was truly a happy idea to create in America a university of higher
studies, devoted not only to the labor of teaching, but also very especially
to giving impulse to pure science. It has been said many times, but never
enough, that there is no lasting industrial progress if it is not connected,
as a brook with it^ source, with the creation of original science.
No matter how great the practical genius of a nation, it is impossible
for it to preserve its political, commercial, and industrial hegemony, unless
it comes out intellectually superior to other nations, unless it attends with
equal care to the laboratory and to the mill, to the ideas as well as to the
inventions, to the philosophy and to the science which guide as well as to
the art which carries out.
This happy alliance between theory and practice is what places Ger-
many to-day at the head of civilization. It would be easy to adduce num-
berless examples of the supremacy which industry, founded on science,
holds over empirical industry created at haphazard according to the
inventive character of each nation. I will quote only two — the chemical
industry of the aniline dyes created chiefly in Germany, which assures
to that nation an immense wealth ; and the optical industry representing
all kinds of apparatus (microscopes, photographical and astronomical
object-glasses) which sprung up under the inspiration of the great
mathematicians, Abbe, Rudolph, Goertz, and others, and which by its
manifest superiority over that of other nations procures to Prussia a
monopoly which makes the whole world her tributary.
22 Decennial
That is the right way, the only one which leads to glory, wealth,
and power. I trust that the creation of Clark University may give the
signal for foundino^ in America other similar institutions embracing a still
larger number of branches of science, and having as their primary object
the wresting of secrets from nature, supplying industry and arts with
principles and facts capable of fruitful applications, forming the research
spirit of the new generation, freeing it from the clogs of routine and
imitation, and finally forming the foundation of a splendid civilization
superior in groundwork, as well as in form, to that of the European
nations.
Atjgtjst Foeel.
I THANK you heartily for the great honor you have bestowed upon me
by conferring upon me the degree of doctor of laws, honoris causd, of
Clark University. But I accept this honor less in my own person than
as a representative of Switzerland at your celebration — in the name of
my little fatherland. Although nowadays the Swiss Federation disap-
pears beside the powerful republic of the United States, yet she prides
herself still on being the little old mother of democracy, which has fought
for her free rights for centuries, and has maintained them up to the
present day. I offer my heartiest congratulations for the brilliant success
which Clark University has achieved during the short time of its exis-
tence in the high domains of philosophy, pedagogy, and of many a scientific
foundation of social questions. But we must also offer our heartiest
thanks and congratulations for the generous and magnificent gifts of
American citizens for the furtherance of scientific and social progress.
Allow me to add a wish. Let Clark University continue to pursue —
under the successful guidance of her excellent President, Professor G.
Stanley Hall — her researches in the regions of psychology and pedagogy
together with those on the brain and its life, and thus to further the
investigation and the building up of truth in the teeth of all prejudices.
Let her help to bury the old roads of barren metaphysical dogmas and
speculations, and thus develop in its entirety the only fruitful ethically
built-up progressive method of scientific investigation in these domains,
as a blessing to our posterity and for the good of a better and happier
humanity.
Celebration. 23
Angelo Mosso.
I OFFER my thanks to Clark University for the honor bestowed upon
me. I shall carry with me to Italy a happy remembrance of the many
proofs of sympathy and friendship which I have received in the Uni-
versity and the city of Worcester. It is not only the expression of my
gratitude that I offer you, but also my great admiration for all that I
saw in your University, and especially the development in experimental
psychology under the happy impulse which the President has given to
this branch of science. It is not only on my own account that I offer
you my thanks, it is also because, on my return to Italy, I hope to found
in the University of Turin a school of experimental psychology.
Emile Picard.
I offer my heartiest thanks to the President and Professors of Clark
University for the degree just conferred upon me. I have been also greatly
touched by the honor you bestowed upon me by inviting me to give a few
lectures during this academic celebration. Your desire was thus to bear
witness to your sympathy with men of science in France. We follow on
our side, in France, with great interest the American scientific movement,
and we rejoice in seeing closer relations established between our universi-
ties and those of this country. Science treads its ascending march on
different roads, and research work requires to-day the most varied apti-
tudes. The initiative and the energy which are prevalent in this country
will not be wanting in occasions for displaying themselves, and, in all
branches of studies, the American scientists will be able to erect some-
thing equivalent to those large telescopes by means of which your astrono-
mers have made such beautiful discoveries. It is in the universities which,
like this one, are devoted to research, that the scientific movement is bound
to have its origin. From everything I have seen and heard for the last
few days, I am certain that the eminent professors of this University
devote themselves with success to this noble task, and I beg to offer my
most sincere wishes for the continuance of the brilliant development of
Clark University.
The exercises concluded with prayer by Dr. Vinton.
The closing exercise of the decennial was a reception which was
attended by between five hundred and six hundred ladies and gentlemen
24 Decennial Celebration,
of Worcester. The arrangements had been made under the direction of
Assistant Professor Henry Taber and Professor William E. Story. The
large lecture-room and corridors were decorated with festoons of green
and white, the flags of the United States and of the native countries of
the foreign guests, and with potted plants. A collation was served in the
library, and many pieces of apparatus were exhibited in operation in the
physical and psychological laboratories.
The following persons received : President G. Stanley Hall, Miss
Florence E. Smith of Newton Centre, Mass., Mrs. A. W. Beals of Stam-
ford, Conn., Hon. Stephen Salisbury, Dr. Edward Cowles, Miss Gage,
Professor and Mrs. William E. Story, Assistant Professor and Mrs. Arthur
G. Webster, Assistant Professor and Mrs. Clifton F. Hodge, Assistant
Professor Edmund C. Sanford, Miss Sanford, Assistant Professor Henry
Taber, Dr. and Mrs. A. F. Chamberlain, the foreign lecturers, Senora
Ramon y Cajal, and Frau Boltzmann.
The press of Worcester gave very full and detailed accounts of all
that transpired during the week except the scientific lectures, all of which
were in foreign languages and upon very technical subjects.
The following original documents have been bound and filed in the
University library : —
(1) The congratulatory letters, telegrams, etc.
(2) The correspondence with the foreign lecturers, and the letters of
acceptance and declination from American professors.
(3) The letters of acceptance and declination to the reception in the
evening.
The weather was somewhat warm during the first few days, but was
clear and cool on Saturday, Sunday, and Monday. The hospitality of
Worcester people was all that could be desired.
CONGRATULATIONS.
The following extracts are taken from many hundred congratulatory-
letters, personal, official, and from institutions and educators of all grades
and many lands.
Congratulations on the conclusion of the University's first decade, and best
wishes for the successful continuance of the work it has undertaken.
William McKinlbt, Washington, D.C.,
President of the United States.
The attraction will be strong to all who are interested in the great subjects
which these distinguished men will discuss, or in intellectual eminence for its
own sake. Your occasion will be the most distinguished gathering that will
occur in all New England this summer. . . .
The high plane of the work done at Clark University, the only institution
in our country exclusively devoted to original research and the instruction of
advanced investigators, so far as I am aware, is well known to all who have
followed the course of the University. Modestly, and without ostentation, it
has pursued its noble ideals. If, under your able direction, its means were more
extensive, the University would, doubtless, become the centre of a still larger
circle of influence in the training of men for the prosecution of original research
and the conduct of similar work in other institutions. I trust that your own
large plans and those of the founder of the University may enjoy a complete
realization, and that its future may be crowned with the high success which so
great an enterprise rightly deserves.
Felicitating the honored founder, yourself, the trustees, and your colleagues
in the faculty upon the great occasion you are soon to celebrate,
David J. Hill, Washington, D.C.,
Assistant Secretary of State.
It is one of the chief regrets of my life that I cannot attend the celebration
of Clark University, Be assured that no reason personal to myself has pre-
vented my attendance. I have seriously considered the question of crossing the
Atlantic for the purpose, and coming back here immediately afterward. But
that seems impracticable.
25
26 Extracts from
We have to congratulate the University upon ten years of success. It was
not to be expected that an institution whose aim is to lift the university educa-
tion, not only of this country, but of the world, to a higher plane, and to break
out a new and untrodden path, should command popularity in the beginning, or
that its success should at once be recognized by the general public. But we
have no cause for regret or for discouragement. Teachers whom we have edu-
cated are found in institutions of the first class in all parts of the country, and
all parts of the world have sent representatives to receive our instruction. This
is largely due to the wise and far-sighted intelligence of the founder, and, next,
to your own constant and self-sacrificing labors.
There have been times during these ten years when we have been tempted
to think that the people of Worcester have been cold, and have been lacking in
the liberality which we had hoped from them when we started. But in looking
at the history of other institutions which are now useful and flourishing, it will
be seen that they had in the beginning a like experience. I remember well a
time when it almost seemed impossible to get the people of Worcester to endow
a public library. But the hour came and the man came, and our public library
is now munificently endowed and is a model of library administration. The
Polytechnic Institute had its day of small things. But the liberality of two
citizens of Worcester of the same name and race, whose two lives seem almost
like the prolonged life of one individual, came to its aid, and it is now doing its
work with large endowments, and its scheme has been copied by other institu-
tions all over the country. I do not for a moment doubt that the time will come
when our endowments will enable us to maintain in the entire circle of univer-
sity education the position which we have taken and hold with regard to a few
subjects. Already an eloquent orator, formerly head of the National Catholic
University at Washington, has referred to Clark as " that little institution in
Worcester which has added a new story to university education, and
' Wliich allures to brighter worlds and leads the way.' "
An eminent professor of science from the English Cambridge declared at a
meeting in the British Association, in the presence of famous scholars from all
parts of the world, that there is one thing that England envies America, and
that is Clark University.
There is nothing except the country itself which ought to inspire a deeper
devotion in its children than a university. As time goes on this feeling, made
up of love and gratitude, will be found in fullest measure among the alumni of
Clark. As they go out to reap the harvests of success in life, they will repay
to their alma mater, in their own way, the great debt they owe her. When that
time comes I have no fear that her endowments will not be ample to accomplish
the work she has undertaken. In the meantime those of us to whom the con-
fidence of the founder has committed a share in her administration must renew
our own vows of fidelity to her service.
Among the many public honors which the undeserved kindness of my fellow-
Congratulatory Letters. 27
citizens has bestowed upon me, I count none higher than my selection as one of
the first board of trustees of this institution. I trust that your celebration will
be full of delight for those who gather there, that they will look forward with
bright hopes to the future, and that an immortality of fame and usefulness may
await the institution which now celebrates its tenth birthday.
George F. Hoar,
United States Senator.
I learn from your formal letters of invitation that you are to celebrate the
close of the first decade of Clark University. It is one of the most wonderful
careers to be chronicled in the history of American education. I congratulate
you on your eminent success in conducting your University in so efficient a
manner toward the improvement and elevation of pedagogy in the United
States. Your movement is all the more valviable because it challenges the aims
and purposes of the present existing education. It is an elementary force in
making the American teachers circumspect and reflective, and causing them to
seek deeper principles on which to ground their practice and on which to im-
prove it. Hoping that there will be a long series of equally useful decades in
the history of Clark University and in your own successful directorship of that
institution,
W. T. Harris, Washington, D.C.,
Commissioner of Education.
I cannot refrain from offering my congratulations to the President, Trustees,
and Faculty for securing the services of such distinguished lecturers, as well as
for the marked success that has attended Clark University during the first
decade of its existence.
Willis L. Moore, Washington, D.C.,
Chief of Weather Bureau.
I must add my profound appreciation of the great work for the highest
science that is being accomplished by you. The solid knowledge that consti-
tutes " Science" is a rather slow growth — it can only advance in proportion as
man frees himself from ancient errors and evolves higher powers of observation
and reason. The fine work done at Clark, the excellent memoirs published by
its professors, and now these attractive lectures, give us all the assurance that
your labors for the highest attainments in the study and teaching of science
will be abundantly rewarded.
Cleveland Abbe, Washington, D.C.,
Weather Bureau.
Congratulating you on the successful rounding out of the first decade of the
University, and with best wishes for the success of the institution in the
future, ^ , . -n. ^
W. J. McGee, Washington, D.C.,
Smithsonian Institution.
28 Extracts from
I send you most cordial greetings on the interesting occasion, and hope the
future of Clark will be as successful as the past, and that your plans for scien-
tific research may be realized in the fullest degree.
Carroll D. Wright, Washington, D.C.,
Commissioner of Labor.
One may well be envious of the gratification that the generous founder of
Clark University must feel at the world-wide recognition of its achievements
during the very first decade of its existence.
To have established a just claim upon the regard of foremost men associ-
ated with educational establishments in this country and in Europe is of great
significance.
The work that the University has done and is doing will continue to attract
to its halls those rare geniuses who, impressed with the transcendent importance
of the science of Pedagogy, of Physiology and Psychology, seek with unfailing
diligence to penetrate their inmost depth. This work can scarcely fail to exer-
cise a beneficial influence upon the schools of the country, and become a distin-
guished attraction to the city which is fortunately the home of the University,
whose citizens will give it welcome and encouragement and markedly recognize
the munificence of its founder, as well as the labors of those who have in so
brief a time established it among the foremost seats of learning.
Andrew H. Green,
214 Broadway., Neio York City.
As I shall not be able to be present during the exercises on Monday, July 10,
celebrating the completion of the tenth academic year of Clark University, I
desire to express in writing my feelings of sympathy and my strong desire for
the success of the University, and also to extend to you and your co-workers my
sincere congratulations on this auspicious occasion.
It is probably true that the initiative step of the institution was not fully
understood or appreciated by the public, but during the past ten years it has,
under your able and judicious direction, steadily pursued a course well calcu-
lated to win its way to public confidence and to an abiding position among
the most eminent and distinguished institutions of learning in the civilized
world.
The entire exercises attending the celebration are calculated to draw aside
the mystic veil, and when the occasion shall have been numbered among past
events, the general public will be led to see and know Clark University in the
future as it has been seen and known in the past by distinguished foreign scien-
tists and educators.
Yes, rest assured, President Hall, that before the last hour of the present
century has been struck by the unerring and mighty hand of time, Clark Uni-
versity, the far-seeing, noble, and generous founder, together with the Univer-
sity's learned and distinguished first president, will have been crowned by
Congratulatory Letters. , 29
truth and justice with the laurel wreath of victory, exalted merit, and uni-
versal appreciation.
Thomas H. Dodge, Esq.,
Worcestei'.
James Brice begs to be permitted to offer his congratulations upon that
occasion.
Will you please convey to them my best wishes for the continued prosperity
of Clark University. It has a high mission ; for gathering in new knowledge
is a much nobler task than distributing that which is known, useful as the latter
may be.
I feel confident that when your present age is lengthened tenfold and
your successors celebrate the centenary, they will hold up a great record of
influence for good in the States and in the world.
Pkofessor Michael Foster,
University of Cambridge, England.
Though thus tardily, it is none the less heartily, that I congratulate you and
your colleagues and fellow-citizens in this celebration — and this not simply on
reaching your first natural period of retrospect, but on the worthy manner of the
celebration also. You are certainly setting forth a feast of rare and varied
intellectual fare, and thereby also giving a great lesson to us in the Old World
of that return to the international unity of universities, which it is fitting that
you in America should lead. Agarn accept these my best wishes for the cele-
bration, with hearty congratulations upon your vigorous and productive youth
— with confident hope also of your yet more productive maturity.
Professor T. W. Geddes,
University of Edinburgh, Scotland.
Arthur Bienatme (Toulon, France) addresses to the President his most
sincere prayers for the prosperity of the University.
I address my wishes for the brilliant future of your University.
Professor Alfred Binet,
Paris, France.
I find it unfortunately impossible to avail myself of your invitation, for I
certainly would have desired to enter into personal relations with men who join
to their high science a largeness of view seldom to be met with.
Professor Jules Tannery,
Paris, France.
30 Extracts from
My congratulations on the completion of the tenth academic year of the Uni-
versity, with my best wishes for its increase and prosperity.
Pkofessor Adolf Baginskt,
University of Berlin, Germany.
I avail myself of this occasion to express my heartiest wishes for the further
prosperity of your University. I rejoice at the admirable way in which you are
to celebrate the foundation of your institution, thereby showing that it is to
remain what it has hitherto been: the home of scientific investigation and
culture.
Pkofessor Max Dessoir,
Berlin, Germany.
I express my heartiest wishes for the prosperity of your University, whose
scientific activity has so soon won for it a high place among the universities of
your country.
Professor Benno Erdmann,
Bonn, Germany.
In your effort to unite the nations under the banner of unselfish science,
accept my most cordial congratulations and wishes for prosperity.
Professor Paul Flechsig,
University of Leipzig, Germany.
I request you to receive my sincerest congratulations to this academical
solemnity, and the expression of my hope, that your institution, highly ad-
vanced through many difiiculties and sacrifices, may enjoy the most splendid
prosperity for many secula.
Professor Ernst Haeckel,
University of Jena, Germany.
I send to you and Clark University best wishes for success.
Professor Felix Klein,
University of Gottingen, Germany.
Permit me to express my warmest wishes for the future prosperity of your
University, which, called to life ten years ago, has already won such deserved
success.
Professor Kuhne,
University of Heidelberg, Germany.
Accept my heartiest congratulations on your approaching celebration, and
may it be the dawn of a still more momentous era than the preceding one has
already been.
Professor Oswald Kulpe,
University of Wurzburg, Germany.
Congratulatory Letters. 31
May the following decennium of Clark University be prosperous in its
development and rich in scientific results.
Professor Lindemann,
University of Munchen, Germany.
I express my good wishes on the occasion of the celebration.
Professor Max Noether,
University of Erlangen, Germany.
I do not want to let slip the opportunity of expressing my best wishes for
the University which has done so much for science, and is spoken of, particu-
larly in Germany, with the highest respect and esteem.
Professor Ranke,
University of Munchen, Germany.
With the best wishes for the growth and success of your University,
Professor W. Rein,
University of Jena, Germany.
I offer my best wishes for the welfare and progress of the University,
Professor C. Rdnge,
Hannover, Germany.
Permit me to send my heartiest congratulations on this celebration. Under
your guidance Clark University has, in the ten years of its existence, already
won for itself a high reputation in the whole scientific world. May the second
decennium continue like the first to advance and increase science, and may it
be granted to you, Mr. President, for many years to come to be the standard-
bearer of the scientific labors of Clark University.
Professor Hermann Schiller,
University of Giessen, Germany.
Wishing the University further prosperity and progress.
Professor P. Schur,
Karlsruhe, Germany.
I remember my sojourn in America and the kind reception which I met
with in Worcester. I should rejoice to have the opportunity to renew the
hospitality shown me by yourself and by your colleagues.
Professor E. Study,
University of Greifswald, Germany.
May the young University, which has already developed so auspiciously,
continue according to the old saying : Vivat, floreat, crescat !
Professor Waldeter,
«• University of Berlin, Germany.
32 Extracts from
I should have also been especially desirous of bringing to you my own
recognition of what has hitherto been accomplished and my cordial wishes for
the future. I follow with great interest particularly the psychological works
which proceed from your University and are published in the American Journal
of Psychology. I have always received from them the impression that the
psychological and pedagogical departments of your University belonged to the
most important institutions of their kind.
May Clark University complete the second decennium of its existence
with like, and where possible, increasing glory !
Professor W. Wdndt,
University of Leipzig, Germany.
Accept my warmest wishes for the development of the University.
Professor Ed. Wetr,
University of Prague, Austria.
I feel a great pleasure in congratulating your Clark University on the cele-
bration of the festival ; and allow me to express the hope that your University
may extend its activity with every year to the honor of its President, its
Trustees, and all its Members.
Professor S. E. Henschen,
University of Upsala, Sweden.
I beg you to receive my cordial congratulations on the occasion of the
beautiful decennium which your University has completed. I hope that this
seat of learning shall have a future correspondingly to the excellent manner in
which it has begun its life.
Professor H. Hoffding,
University of Copenhagen, Denmark.
I beg to present my sincere congratulations upon the erection of a scientific
centre, the decennium of which you are to celebrate in so fitting a manner.
Professor Zeuthen,
University of Copenhagen, Denmark.
I send you the best wishes for the success of your celebrated University,
Professor Vito Volterra,
University of Turin, Italy.
Eternal prosperity to the vigorous propagator of light.
Professor Stephanos,
University of Athens, Greece.
Dr. Wesley Mills (McG-ill University, Montreal, Canada) wishes the Uni-
versity every success in the future. •
Congratulatory Letters. 33
Witli best wishes for the continued prosperity of Clark University,
Professor J. Squair,
University of Toronto^ Canada.
President Angell (University of Michigan) congratulates them on the
useful work which the University has already accomplished.
With hearty congratulations for what you have already achieved as President
of Clark University, and in full assurance of a great future before you,
Henry Barnard, Hartford, Conn.,
Ex-U. S. Commissioner of Education.
William W. Birdsall (President Swarthmore College) desires to extend
congratulations upon the completion of the tenth year of Clark University.
I congratulate you most heartily on the splendid work which Clark Uni-
versity has accomplished during the ten years of its existence. Nothing in
our educational work has reflected greater honor upon the American system
than the high ideals so successfully maintained at Clark University.
President John E. Bradley,
Illinois College.
Good wishes to the University in all its undertakings, and congratulations to
President, Trustees, and Faculty upon the completion of ten years of distin-
guished usefulness. Professor C. L. Bristol,
New York University.
My deepest wish is that Clark may do as much more for the advancement of
science and the deepening of the true university spirit in the next decennium
as it has in the one now closing.
Professor Edward F. Buckner,
Teachers'' College, New York City.
I beg leave to extend to you my most sincere congratulations on the work
that Clark University has accomplished under your guidance, since the time of
its founding, ten years ago.
As a Fellow of the University, I enjoyed opportunities for work that other
institutions could not afford, and I found your efforts to provide books, instru-
ments, and material as effectual as they were untiring.
As a Graduate I have found inspiration in your zeal for the furtherance of
all that can advance education and science.
I have followed the development of the University with pride. The first
high ideals have not been lowered, and Clark remains, as it was at its founda-
tion, a University for Universities.
Professor H. C. Bumpus,
Brown University.
34 Extracts from
No undertaking nor movement has made so clear and definite impress upon
the educational thought of America nor established guiding lines of control
so distinctly in pedagogical and psychological progress as the suggestions and
tendencies which have emanated from Clark University. Though the institu-
tion is yet in its infancy, though the students in point of numbers have been
limited, yet its influence has penetrated every state in the Union, has entered
practically every educational institution of the land, from university to kinder-
garten, and has quickened the spirit of educational conferences, from those of
national repute to those of the little teachers' meetings of the village school.
Granting the truth of the educational view for which Clark University
stands, and allowing for the singularly forceful methods of instruction by the
President and Faculty within the institution, and the energy with which its
mission has been prosecuted, it is nevertheless still a marvel that its influence
should have become, in this brief space, so widespread and vigorous. The facts
which stand prove the wisdom of the plan of an institution which should be
exclusively graduate, selecting as its students a limited number of mature
thinkers who should be inspired by the power wliich ever comes from the con-
tact with original investigation and a faculty of original investigators.
rREDERicK BuRK, President State Normal School, San Francisco, and
President Clark University Alumni Association of California.
I send my best wishes for the success of the anniversary exercises and for
the continued and enlarged prosperity of the University.
President Nathaniel Butler,
Colby University.
Kindly accept my congratulations upon the completion of your tenth aca-
demic year.
Professor E. H. Chittenden,
Director Sheffield Scientific School.
I desire to congratulate the Faculty of the University on the great work
accomplished within a comparatively short period.
Brother Chrtsostom,
Manhattan College.
We rejoice with your many friends in the successful rounding out of Clark
University's first decade. It is a consolation to the generous benefactor that
the world recognizes the merit of the Institution, which his munificence estab-
lished and maintains. Coming into existence the same year, holding similar
views as to the place of graduate work, having the highest ideals of university
endeavor, striving earnestly to realize them in spite of all difiiculty, our two
Universities have always felt strong attachments for one another, and a more
than ordinary interest in one another's success. The Catholic University ten-
Congratulatory Letters, 35
ders you its most cordial greeting on this the day of your rejoicing. It bids me
extend to you and through you to the University its most sincere wishes for
still higher and greater success in its chosen fields.
Thos. J. CoNATT, Washington, D. C,
Rector Catholic University.
With many congratulations on the past ten years' work of the University,
Professor Charles K. Cross,
Massachusetts Institute of Technology.
Professor C. B. Davenport (Harvard University) desires to express his
appreciation of the brilliant example of research as a primary university func-
tion which Clark University has for a decade set.
The University and all connected with it are to be congratulated.
Professor Ellbrt W. Davis,
University of Nebraska.
I desire to express my appreciation of the splendid work done by Clark
University during these ten years.
Professor Nathaniel P. Davis,
Brown University.
I must content myself with rejoicing over the unique intellectual enterprise
you are carrying out. I may not be informed regarding such matters, but it
seems to me you have accomplished a sort of scientific coup cVetat in getting
such a group of scholars to come to America upon the occasion of your anniver-
sary. As a disciple of Clark University, and an admirer of everything it stands
for, I take pride in the impression that must necessarily be made upon Ameri-
can scholarship by the visit of such men. I congratulate all of you, and hope
that everything you desire in connection with the series of lectures may be
realized.
Professor George E. Dawson,
Bible Normal College, Springfield, Mass.
President Drown of Lehigh University begs for his colleagues and for
himself, to offer his hearty congratulations to the President, Trustees, and
Faculty of Clark University on the completion of a decade of usefulness in
the higher education, marked by distinguished services in many lines of
original research.
Permit me to express my admiration of the work you have done and are
doing.
Professor William P. Ddrfee,
Hohart College.
3Q Extracts from
Let me assure you that we are all grateful for what Clark University is do-
ing for sound education in this country, and I can only hope that you may have
many successful years in the development of the work which you are doing.
S. T. DuTTOx, Brookline, Mass.,
Superintendent of Schools.
In the opinion of many who have studied there, the peculiar advantage of
Clark University is mainly attributable to the close and personal relations
between professors and students under which the work is conducted. The
formal lecture delivered to a body of men in the class-room has but little of the
stimulative force imparted by a conversational discussion with the man alone in
the lecturer's private study, and too great praise can hardly be given to the
members of the faculty of Clark for their constant and generous sacrifice of time
to this most helpful method of instruction. The frequent assignment through-
out the course of problems involving research leads to the best of training for
the later performance of original work, and the presentation in the lecture-room
of the results thus obtained gives experience in the work of the lecturer. In
perhaps no other institution are these methods of the personal conference and
the "colloquium" so constantly applied; no doubt such methods are impossible
in most larger universities at present ; and one can hardly imagine such a course
followed with more kindness and devotion at any time than is now the case at
Clark.
Professor Frederick C. Ferry,
Williams College.
I take this means of expressing my interest in the noble success of the
University, and of wishing it continuance and increase.
Rabbi Charles Fleischer,
Boston, Mass.
Congratulating you and the University upon these years of achievement,
Alice C. Fletcher,
Washington, D. G.
I rejoice in the prosperity of your institution because it is one which sends
forth its light, not only for the few, but for the many.
President Wm. Goodell Frost,
Berea College.
Though my stay with you was short, yet it meant the inspiration that took
me abroad and pushed me on to undertake important work.
Professor John P. Fruit,
William Jewell College.
Congratulatory Letters. 37
The Johns Hopkins University sends its cordial greetings to the President,
the Trustees, and the Faculty of Clark University, on the completion of its first
decennium, with congratulations upon its successful maintenance of high ideals,
and with best wishes for its continued prosperity and power.
President Daniel C. Gilman.
I must add my congratulations on the success of your work, and my good
wishes for its continuance on even a larger scale.
Professok George L. Goodale, .
Harvard University.
Every educator especially owes a debt of gratitude to Clark for the fearless
work it has done in breaking down blind prejudice and advancing the truth.
Professor John Y. Graham,
University of Alabama.
You have certainly arranged a most dignified and impressive series of
lectures — wholly congruous with the work which you have been doing during
the decade.
Professor Edward H. Griffin,
Johns Hopkins University.
You will please accept the assurance that I am very glad indeed that your
institution, which has already done so much for the cause of progressive educa-
tion, has thus shown its vitality and power of endurance. No doubt these ten
years have meant much struggle and anxiety on the part of those whose heart
was in the work. Others may be able to express their appreciation of this work
with greater eloquence, but none can be more sincere and thankful than I am.
Truly, if there is such a thing as a science of education in this country now,
Clark University . . . (has) contributed the largest share toward this accom-
plishment. To me (its) work has meant an awakening and uplifting hardly
equalled by any other influences that have worked upon my soul. May your
anniversary week be a thorough success.
Professor M. P. E. Grossmann,
Milwaukee., Wis.
Allow me to extend cordial congratulations on the auspicious event.
Professor Charles W. Hargitt,
Syracuse University.
I extend for the University of Maine hearty congratulations, and wish con-
tinued prosperity for the future.
President A. W. Harris,
University of Maine.
38 Extracts from
I send you my hearty congratulations on your decennial celebration.
President Walter L. Hervet,
Teachers' College, Neio York City.
I congratulate you and the Trustees and Faculty upon these successful years
of your University work, and upon this most appropriate mode of celebrating
the anniversary. It is a mode worthy of universal following, and will, without
doubt, be more and more adopted by our institutions of higher learning.
Professor G. H. Howison,
University of California.
Allow me to offer my congratulations to you especially, and to your associ-
ates, for the marked success which has attended the career of Clark University.
We have felt that it not only increases the resources of high education for
youth, but it stands for progress and enlightenment in the commonwealth and
the country at large. There is a justifiable pride on the part of those who love
earnestness and progress in educational matters, as they review the past of this
institution, into whose good name and wide scope of influence you have thrown
so much of your personal enthusiasm as well as your scholarly ability.
Rev. Edward A. Horton,
Boston, Mass.
I have many pleasant memories of a year's profitable work at Clark, and
rejoice in the continued success of Clark University.
Professor L. S. Hulburt,
Johns Hopkins University.
The programme presented is most attractive and inspiring. I congratulate
you upon the successful work of the past ten years.
Dr. Henry M. Hdrd, Baltimore, Md.,
Superintendent Johns Hopkins Hospital.
I can't help expressing to you my feeling of satisfaction, and repeating the
satisfaction I heard such men as Cattell, Eoyce, Van Gieson, Mtinsterberg, and
Putnam express, with the excellent good taste and refinement of your little
celebration. All the refinements of the world seem now to take refuge in the
smaller things ; the bigger ones are getting too big for any virtue to remain with
them. You have done something original and succeeded perfectly, from the
point of view of the passive " assistant."
Professor William James,
Harvard University.
I beg you to accept my heartiest congratulations. Each year, I sincerely
believe, finds me more grateful and appreciative of the privileges I enjoyed at
Congratulatory Letters. 39
Clark, and especially do I realize more and more what you yourself did for me.
I trust you may be spared health and vigor many years to come in your labor,
for you are doing a great work.
George E. Johnson, Andover, Mass.,
Superintendent of Schools.
I have been very deeply interested in the work of Clark University, and in
the way it has held to its high purposes regardless of pressure of all sorts in
other directions. . . . Stanford congratulates Clark on ten years' noble work
for high thought and accurate investigation.
Pkesident David S. Jokdan,
Leland Stanford Jr. University.
For myself and all the staff of the University of California, I send you
hearty congratulations and good wishes. You have not attempted to do as
many things as some other universities, but what you have attempted you have
done exceedingly well. If excellent work is the standard of true success, you
have been successful among the foremost.
May your achievements and your reputation gain still greater lustre, and
your educational work confer still larger benefits on succeeding generations.
President Martin Kellogg,
University of California.
May I say that I think you have taken a most admirable course in the char-
acter of this celebration, and that I wish you every success, not only on this
occasion, but in all the future years of the University.
Professor J. S. Kingsley,
Tufts College.
I regret more than I can express my inability to be present at the decennial
celebration of your noble institution, and to hear the splendid series of lectures
which you have provided.
Professor Joseph LeConte,
University of California.
It is a pleasure to me to join in the celebration of the first decade of Clark
University. The method of celebrating the event is, I think, exceedingly fit-
ting. I enjoyed several of the most interesting years of my life in the lecture-
rooms and laboratories of Clark, and always recall them with great satisfaction.
Professor J. S. Lemon, Washington, D. C. ,
Columbian University.
Clark University stands unique among the universities of this country in the
work which it is attempting to do. No other institution has done more in the
40 Extracts from
line of original investigation, nor given during the same period greater inspira-
tion to the educators of the country.
Professor G. W. A. Lucket,
University of Nebraska.
Permit me to congratulate heartily the President, Trustees, and the Faculty
of Clark University upon the completion of the tenth academic year of the
University.
President George E. MacLean,
University of Nebraska.
We appreciate the great ■work done by Clark University, and send every best
wish for the future.
President James G. K. McClure,
Lake Forest University.
I have the highest feelings of regard for Clark University, for I feel that I
owe much to it. Its conception is the broadest and best of all our institutions,
and I hope the time will come when it can broaden out, and, all obstacles
being removed, go on to its full completeness.
Professor William S. Miller,
University of Wisconsin.
When one thinks of the amount of light that has spread from Clark Univer-
sity and of the place that it fills in American education to-day, it is hard to
realize that no such institution was in existence ten years ago. Please accept
my most sincere congratulations to this auspicious event, with the hope that a
long series of years of vigorous activity may be granted to you, so that you may
lead the University to ever new achievements, and continue to benefit the cause
of education in the future, as you have so splendidly done in the past. Vivat,
Jloreat, crescat.
Professor F. Monteser,
Neio York University.
It is with very great regret that I find it impossible to attend the rich cele-
bration you have prepared for the friends of Clark University and of all the
forward movements in science for which you have made Clark University stand,
and wish the University long-continued and increasing prosperity.
Professor E. H. Moore,
University of Chicago.
My participation in the treasures you offered was thus limited to one day —
but this one day, with the three lectures I listened to, and the very interesting
men I met, was so agreeable and valuable that I feel the desire to thank you
warmly for the distinguished and exquisite pleasure. I take special pleasure
in combining with my personal thanks my congratulations to the high success
Congratulatory Letters. 41
of the celebration and my very best wishes for the next ten years in the life of
Clark University.
Professor Hugo Munsterberg,
Harvard University.
Permit me to express here my sincere admiration and respect for the aims,
ideals, and plans of Clark University ; these are of such an ideal character that
they are bound to interest profoundly every man who loves science for its own
sake.
Professor J. U. Nef,
University of Chicago.
Permit me to offer my hearty congratulations on the work done and the
progress made in the ten years of Clark's existence, to express the hope that the
future may be marked by even greater achievements.
President Ctrus Northrop,
University of Minnesota.
Clark University does well to celebrate in such a becoming manner the noble
service which she has rendered to higher education in this country. May the
next ten years be no less fruitful and helpful to those who have become
accustomed to look to Clark University for inspiration and guidance.
Professor F. W. Osborx,
Adelphi College, Brooklyn, JSf. Y.
I write to congratulate you most cordially upon your celebration of the com-
pletion of the tenth academic year of Clark University.
Professor Henry F. Osborn,
Columbia University.
Allow me to congratulate you upon these lectures, and also upon the remark-
able results which you have been able to accomplish in ten years in connection
with Clark University.
Professor G. T. "W. Patrick,
University of Iowa.
The Provost, Trustees, and Faculty of the University of Pennsylvania
present their cordial congratulations to the President, Trustees, and Faculty of
Clark University on the happy completion of the tenth academic year of the
University.
The President, Trustees, and Faculty of Clark University certainly deserve
the thanks of all those interested in the cause of education.
Professor George H. Price,
Vanderbilt University.
42 Extracts from
Pray accept congratulations on the completion of a decade of grand work,
and on the prospects of even better work for the future.
John T. Prince, West Newton, Mass.,
Agent State Board of Education.
I send my heartiest congratulations on the great achievements of Clark
University during its first decade, and express my sincerest desire that its use-
fulness may continue and expand for many centuries to come.
Professor Ernst Richard,
New York City.
President H. W. Kogers (Northwestern University) desires to extend the
congratulations of Northwestern University, as well as his own, upon the great
success of Clark University and the distinction it has attained in the academic
world.
James E. Eussell (Dean, Teachers' College, New York) wishes to convey
to the President of the University his best wishes for the continued success
and prosperity of the institution.
President L. Clark Seelte (Smith College) offers his hearty congratula-
tions on the important educational work it has already accomplished.
With sincere thanks and hearty congratulations on the auspicious occasion,
Professor James Seth,
Columbia University.
Meanwhile I wish to join in the many congratulations I am sure you will
receive upon the quiet and dignified, but none the less eminent, manner in which
Clark University has carried on the work of the past decade, and upon the
manner in which it has reflected honor upon American scholarship in science
and philosophy.
Albert Shaw, New York, N. Y.,
Editor Beview of Beviews.
We shall always be grateful for the work that has already been accomplished
by the University, and especially for the ideals which it has brought to the
colleges and universities of the West. With high personal regard and warmest
congratulations from our faculty.
President William F. Slocum,
Colorado College.
With best wishes for the success of the celebration and for the continued
prosperity of your institution,
President F. H. Snow,
University of Kansas.
Congratulatory Letters. 43
Allow me to congratulate the University upon its happy completion of ten
years' life and work, and to wish it a long and prosperous future.
Professor Frederick Starr,
University of Chicago.
I wish to send my cordial congratulations and my wish that the next ten
years may witness the coming to the University of such ample endowments
as will enable it to accomplish its high ideals.
President James M. Taylor,
Vassar College.
Please accept my best wishes for continued prosperity.
President W. O. Thompson,
Ohio State University.
I do not like to let the present occasion pass without intimating to you my
appreciation and admiration of the methods and aims of university work for
which Clark University has stood in the past, and will, I hope, stand in a
long and prosperous future. My recent visit to Worcester merely confirmed a
belief which I have long held, — that the type of man that Clark University
calls to its professorial chairs, and the type of man that it sends into active life
at the close of its three or four years of graduate study, are types that represent
the highest ideal of scholarship, and are the very salt of American society. I
hope, most sincerely, that the coming celebration will prove to be the door
through which you and the University pass to greatly extended activity upon
your own high level.
Professor E. B. Titchener,
Cornell University.
I wish to express my sincere appreciation of the service to education and
investigation which Clark University is thus undertaking, a service which is
eminently in harmony with the work of Clark University from the beginning.
Professor James H. Tufts,
University of Chicago.
I wish to extend my hearty congratulations on the successful work of the
University during the last ten years, and ray best and most hearty good wishes.
Professor John M. Tyler,
Amherst College.
Professor Henry B. Ward (University of Nebraska) extends to the
President, Trustees, and Faculty his congratulations upon the occasion, and
best wishes for the continued success of the institution.
44 Extracts from Congratulatory Ldiers.
I express my sincere congratulations.
Professor Sho Watase.
University of Chicago.
With best wishes for the success of the University,
Professor J. B. Weems,
Iowa State College.
Please accept congratulations upon the honorable record of these ten com-
pleted years. The distinguished service of yourself and the University have
made the whole world your debtor.
President B. L. Whitman, Washington, D. C,
Columbian University.
The Clark University ideal as I understood it, when connected with its
early work, is the ideal which I place above any others thus far proposed, and
I hope that it may find strong friends to help it forward.
Professor Charles 0. Whitman,
University of Chicago.
Professor A. W. Wright (Yale University) sends congratulations and
best wishes for the prosperity of the University.
DECENNIAL ADDRESS.
By G. Stanley Hall, President of the University.
It has been said that decades are the best periods for studying historic
tendencies because they are long enough to contain a rich array of facts
and events, and short enough to be grasped by a single mind in the stage
of its prime. The ten years since Clark University was opened, the close
of which, by the cooperation of a few beneficent public-spirited citizens of
Worcester, we have sought to mark in a very quiet but dignified way that
should befit at once its size and its quality, constitute distinctly the most
important decade in the educational history of this country. The mere
index of a few of the well-known and accomplished facts of these years
has an eloquence beyond all words. They have witnessed the establish-
ment of the Catholic University at Washington, with its strong faculty
and its handful of picked graduates from the seventy Catholic colleges
of the country, the only university in the land besides Clark devoted
solely to graduate work, an institution related to us, not only by a
strong tie of sympathy in the struggle and sacrifice for ideals and high
standards, but by my own long and personal friendship with the first
rector, and by the fact that its present head was our Worcester neighbor
and kindly friend. The Leland Stanford University, now one of the
richest in the world, was planned and endowed by a long-time friend of
our Founder, and the wife of that founder lately told me that she still
counts ours among her wisest and most trusted advisers. The University
of Chicago, with possibilities of increase brighter and larger than any
other, from the very first the most rapid academic growth in history, has
leaped into existence with a Minerva-like completeness, owing in no small
part its first impulse to higher creative work in science to the sagacity of
the chief trustee of its Ogden Fund, our fellow-townsman, Andrew H.
Green, and which is still more closely affiliated to us by the fact that so
many of the leading members of its faculty honored us by doing three
years of their best work here, and for which we still cherish a little of
45
46 Decennial Address.
the feeling of a poor but proud and noble mother for her great son. The
new Methodist University at Washington has begun the unfoldment of
large and well-matured plans, for the fulfilment of which the vitality of
the strong religious body behind it is perhaps the best of guarantees.
The millions already provided and about to be expended at the State
University of California which will involve transformation and enlarge-
ment perhaps greater than all that has hitherto been done there, very
comprehensive and valuable as that is ; the magnificent new architectural
installation at Columbia and the federation of so many other affiliated
institutions about it, with all the possibilities of our greatest metropolis
open before it ; the steady development, whether for good or for ill, of
the plan of a great national university, to which at least all state, if not
private, colleges and universities may be tributary as feeders, and which
shall command all the vast resources of science in Washington, unify
them, and add the new vitalizing function of research and perhaps teach-
ing, a scheme that has enlisted most of the educational leaders of the
land and is sure of eventual fulfilment, — such are some of the events
which have seemed to many to threaten the academic preeminence of
New England, and even of the East, in the future ; that have stirred to
their very foundations the older and more conservative institutions, and
caused transformations not all apparent from the outside, but which
involve hardly less than an ultimate revolution of academic sentiments,
methods, and ideals. Fellowships, not for the indigent who need support
while preparing for the professions, but to give leisure, opportunity, and
incentive for full development to talent, the choicest of all national prod-
ucts ; research, with books, apparatus, above all, leaders competent to
guide and inspire ; new post-graduate departments for non-professional
specialization, with their own laboratories and libraries ; seminaries where
experts discuss the latest literature, best methods, instruments, and
results of investigation ; new journals devoted to the speedy publication
of such studies ; new chairs and topics ; a growing and ever widening
distinction between receptive learning and active creation, — these and the
gradual completion of a system that is truly national, and has not its
apex in Europe, where hundreds of our graduates still go yearly to get
what it should be a matter of simple patriotism to supply at home, must
suffice to mark the direction and progress of these years in which institu-
tions and work alike are becoming more and more plastic to the changing
and ever more imperative needs of learning and science which have them-
Decennial Address. 47
selves celebrated triumplis during the decade which could not even be
enumerated within the hour. It is no wonder that many old academic
problems have become obsolete and new ones have arisen, and that pres-
ent demands in men, methods, and instruments have changed from those
of ten years ago.
Again, within this time a wave of doubt and opposition to the public
support of intermediate education passed over the country, but the reac-
tion against that tendency has made the last few years preeminently the
age of high schools. More and statelier buildings than ever before,
longer courses and more of them, many modifications suggested by
committees and others, great increase in the number of students, rich
and well-planned departures like the Tome Institute, Mrs. Emmons
Blaine's new normal foundation, and several others contemplated or
assured but not yet established, the new associations of high schools
and colleges covering now all sections of the country, the ever increas-
ing collegiate character of the work done in such institutions, and the
consequent development of a distinct, and in some places urgent, small
college problem, — all this shows that even secondary education, the last
stage to be reached by reforms, has here been stirred and quickened as
never before.
If we extend our view to lower grades, we find all plastic and chang-
ing. This stronghold of conservatism is invaded by the spirit of reform,
often revolution, and sometimes even of rather wild experimentation.
New journals, pedagogical chairs, new methods, the new school hygiene,
broader views that relate teaching to all the great problems of science,
statescraft, and religion, have arisen, which have brought the university
and kindergarten and all between them into an organic unity, yet fitting
all features of the system to the vast variety of individual differences of
character, temperament, and ability. In this field, I think, the closing
decade has witnessed a change greater than the preceding quarter of a
century. New and better minds are enlisted, educational topics are of
increasingly central interest in the press and more dominant in the
church and pulpit, education is becoming more professional and scientific,
recognizing the necessity of expert leadership and mastery, and is at last
assuming its rightful and larger power, and its normal basal all-condition-
ing place as at bottom a biological science, revealing to us how state,
church, home, literature, science, art, and all else have their ultimate
justification only in so far as they are effective in bringing human beings
48 Dece7i7iial Address.
to the ever fuller maturity of mind and body on which civilization de-
pends, and which it is the work of education to accomplish in the world.
This is increasingly necessary as our country grows in population and in
territorial expansion, and educational progress is coming to be recognized
by history as the chief standard by which to test all other advancement.
Europe has progressed during this decade, although with less rapidity,
along nearly all these lines, and the next decennial promises not less, but
more advance. In such a time it is, indeed, glorious to be alive, and to
be young is heaven, for hope is even brighter than memory.
No time in the history of the country could have been more favorable
than the beginning of this period for a great and new university founda-
tion. The epoch-making work of the Johns Hopkins University, which
for the preceding decade had made Baltimore the brightest spot on the
educational map of the country, and was the pioneer in the upward move-
ment, had leavened the colleges and roused them from the life of mo-
notony and routine which then prevailed, and kindled a strong and
widespread desire for better things. The significance of the work of
that institution can hardly be overestimated. But financial clouds had
already begun to threaten this great Southern luminary, and there were
indications that, if the great work it had begun was to be carried on,
parts of it, at least, must be transplanted to new fields.
It was at this crisis that our munificent Founder entered the field with
the largest single gift ever made to education in New England, and one
of the largest in the world, and with the offer of more to come, if suffi-
cient cooperation was forthcoming. He selected Worcester as the site
of his great enterprise with a piety to the region of his nativity worthy of
the greatest respect and emulation, and in addition to the fulfilment of
his pledges gave it the benefit of his own previous wide studies of educa-
tion in Europe, and contributed wisely matured plans and constant per-
sonal oversight and labor for years. It is as strenuously engaged in this
highest of all human endeavors that the world knows him, and that we
shall remember him, and I am sure that we all unite to-day first of all
in sending him in the retirement his health demands (although it cannot
assuage his interest to see the work of his hands prosper) our most cordial
greetings and our most hearty congratulations.
With a dozen colleges within a radius of one hundred miles doing
graduate work, the plainest logic of events suggested at once a policy of
transplanting to this new field part of the spirit of the Johns Hopkins
Decennial Address. 49
University, and taking here the obvious and almost inevitable next step by
eliminating college work, although the chief source of income by fees was
thereby also sacrificed, and thus avoiding the hot and sometimes bitter
competition for students, waiving the test of numbers, and being the first
upon the higher plane of purely graduate work, selecting rigorously the
best students, seeking to train leaders only, educating professors, and ad-
vancing science by new discoveries. It was indeed a new field wide open
and inviting, the cultivation of which was needed to complete our
national life ; the preliminary stages of its occupancy all finished, yes,
necessary almost as a work of rescue for the few elite graduates who
wished to go beyond college but not into any of the three professions,
and who had had hitherto a pathetically hard time. The call to the
President gave assurance of the highest aims and of perfect academic
freedom, a pledge that has been absolutely kept. He was sent to Europe
a year on full pay to learn the best its institutions could teach, and the
Faculty that first fore-gathered here has never been excelled in strength,
if indeed it has ever been equalled anywhere for its size. Story, an
instructor at Harvard, colleague and friend of Sylvester, formerly acting
editor of the chief mathematical journal of the country and co-head of his
department at Baltimore, founder of another journal here, who has
enriched his department by contributions, the list of which printed else-
where in this volume tells its own story ; Michelson, who while here
accepted an invitation of the French Government to demonstrate in Paris
his epoch-making discoveries in the field of light, which he did while on
our pay-roll — lately especially honored by learned societies at home and
abroad, now head of one of the best-equipped and largest laboratories in
the world, and still continuing his brilliant contributions to the sum of
human knowledge ; Whitman, now head of another great university
laboratory, trainer of many young professors, founder and editor of
the best and most expensive biological journal, head of Woods HoU
marine laboratory and summer school, one of the best of its kind in the
world, himself a contributor to his science ; Michael, than whom America
had not produced a more promising or talented chemist, the list of
whose published works would be far too long to read here ; Nef, perhaps
our most brilliant young chemist, and now head of one of the largest
and best-equipped laboratories in the world, and with a power of sus-
tained original work rarely excelled ; Mall, now full professor at the
Johns Hopkins University, and head of the great new anatomical labora-
50 Decennial Address.
tory and museum there, whose published contributions are admirable
illustrations of both the great caution and boldness needed by a student
in his field ; Boas, the leading American in physical anthropology, now
a professor at Columbia ; Loeb, almost the first expert that this country
could boast in the new physical chemistry in the sense of Ostwald, now
head of his department in the University of the city of New York ;
Bolza, an almost ideal teacher, suggesting the great Kirchoff in the per-
fection of his demonstrations ; the brilliant and lamented Baur, leader
of the expedition to the Galapagos Islands made possible by the gift of
Worcester's patron saint of so many good enterprises, Mr. Salisbury;
Donaldson, now dean of the graduate school of the University of
Chicago, author of the best handbook in English on the brain, with
a caution, poise, and diligence befitting the successful investigator in that
dangerous but fascinating field ; MuUiken, suddenly placed in a position
of great diificulty, discharged its duties with rare ability and discretion
for one so young ; Lombard, now professor in Michigan, genial, assiduous,
a gifted teacher and enthusiastic student ; White, scholarly, able, a born
teacher and student ; McMurrich, an untiring investigator and a lucid
inquirer after knowledge ; those now here, who have since become so
well-known, Burnham, Chamberlain, Hodge, Perott, Sanford, Taber, and
Webster ; these, not to mention many others, then only fellows, but who
have achieved so much in their work and positions since, — these are the
men and others whose presence on this spot, whose high intercourse and
whose stimulating personal contact with each other, whose ardor and devo-
tion in the pursuit of knowledge, whose healthful emulation in achieve-
ment, made this almost classic ground and the cynosure of the eyes of
all those in this country who love science for its own sake. With the
wealth, wisdom, and interest of our Founder, with the high character
and culture of our Board of Trustees, with the intelligence of such a
community of old New England, with an atmosphere of intellectual free-
dom, with unique and precious exemption from the drudgery of excessive
teaching and examinations, with the youth of the Faculty, none of whom
had reached the zenith of their maturity, with substantial and ample
buildings, abundant and forthcoming funds for equipment, few rules and
almost no discipline or routine of faculty meetings, the motto on our seal,
fiat lux, our university color white, — is it any wonder if some of our
young men saw visions and dreamed dreams, or perhaps in some cases fell
in love with the highest ideals, or that the very memory of the first stage
Decennial Address. 51
of our history is to-day, as it lias been in darker hours, a most precious
memory and a basis of an all-sustaining hope ?
To these days of our prime to which our former students and profess-
ors recur with joy, and in whose breasts the processes of idealization of
them have already begun, days which were pervaded by sentiments of joy
and hope very like those which animated the best years of the Johns
Hopkins University, we have often reverted since in soberer hours with
longing thoughts of what might have been had the University continued
in all its pristine strength. Not one weak, dull, or bad man in our Faculty,
all given not only leisure, but every possible incentive to do the very best
work of which they were capable, with a Founder and a board of control
who realized that a new endowment should do new things, and that the
best use of money is to help the best men, we entered a field very largely
new and with as bright prospects as we could wish.
But life has its contrasts and competitions. The reductions of our
force, which occurred at the end of the third year, sad to us almost beyond
precedent, although helpful elsewhere, may be ascribed to fate, disease,
or to the very envy of the gods. Some incidents should remain unwritten,
but it should be known that our Trustees foresaw from the beginning of
the year one of the gravest of crises, and met it with an unanimity, a
wisdom, and a firmness which even in the light of all that has transpired
since, I think, could not be improved on. The pain of it all has faded,
the glad hand has been extended and accepted by nearly if not quite all
who left us ; the lessons of adversity have been learned and laid well to
heart, and we hope and believe that these and all their attendant incidents
may be considered closed.
Although nearly half our Faculty and students left us in the hegira,
and our income had dropped in almost the same proportion, and only the
departments of psychology and mathematics remained nearly intact, we
fortunately had left in every department young men as promising as any
in the land. They needed simply to grow, and never has there been such
an environment for a faculty to develop as in this "paradise of young
professors," as a leading college president has called this University. To
Darwin the greatest joy of life was to see growth ; and to see the unfold-
ment of these youthful, intellectual elite, and to feel the sense of growth
with them as all near them must, is a satisfaction almost akin to the
rapture of discovery itself. Now the years have done their work, and
our Faculty, although smaller, was never stronger, never more prolific.
62 Decennial Address.
stimulating, and attractive to students, in proportion to its size, than it is
to-day. There has never been such loyalty to the institution and its
ideals, such readiness to endure the petty and the great economies now
necessary, such prompt and frequent refusals of larger salaries elsewhere,
and so strong a sentiment that, so long as a man has growth in him, our
incentive, opportunity, and plan of work are of more value than a large
increase of salary.
Tliese changes involved, however, but little reduction of the number
of instructors or of students, but materially decreased for a time the effi-
ciency of the University. Since the end of the third year the President,
who was not required to teach, has done full professorial duty in addition
to that of administration, has established a seminary at his house three
hours each week through the entire academic year, and founded and con-
ducted at his own expense a new educational journal. The income-bear-
ing summer school has been organized and conducted during the past
seven years with the active and efficient coo^^eration of a large local
advisory board under the direction of Colonel E. B. Stoddard and Charles
M. Thayer, Esq., by which its social character, that has contributed
much to its success, has been established on a high plane. The summer
school represents only the departments of biology, psychology, and peda-
gogy, is open to every one of either sex on the payment of a small fee, is
popular rather than technical in its scientific character, has been numer-
ously attended, and in all ways is directly in contrast with the work of
the year. Hardly a ripple has marred the harmony within the Univer-
sity during these last seven years, and every man, student and instructor
alike, has been hard at work and enthusiastic for our own unique and
individual method and plan.
This institution must be judged from within and by educational and
scientific experts, and the commendations which we have lately received
from leading specialists, some of which are printed elsewhere in this
volume, have been so numerous, spontaneous, and hearty in response to
our invitation to be present, as almost to rival in cordiality and loyalty
to the now so definitely developed Clark idea and Clark spirit tliat of
our three alumni associations of the Pacific Coast, Illinois, and Indiana
organized during the present year.
Scientific work must be weighed and not measured, so that numbers
tell but little. Clark University has been instrumental in training well-
nigh three hundred professors or special academic instructors, has numbered
Decennial Address. 53
over twelve hundred different persons enrolled in its summer school, not
counting the hundreds who have attended more than one session. These,
especially the former, are in a sense our epistles known and read of all
men. The other output of a university like ours is its scientific work,
and here we have five hundred publications based upon work done here,
of which twenty-five are books. The University now publishes three
journals, with hope of a fourth as a more permanent way of marking the
beginning of its second decade.
Small as we are, if our departments and students are measured by the
significant criterion of the number of the doctorates annually conferred
here, we rank among the best and largest institutions of the land. Al-
though our fellowship funds have declined, and that, too, in the midst
of a competition, which never existed or was hitherto dreamed of, our
numbers of late years have slightly but steadily increased, although at
the same time we could go on forever and do invaluable work of research
and publication like the French Ecole des Hautes Etudes, or a few other
Old World institutions, even if we had no students ; and, indeed, America
may need in the future, if, indeed, she does not already, at least, one such
academic endowment for research only. One thing, at least, is true so
far, hardship has no whit lowered our aims or diluted our quality, but if
anything has had the reverse influence ; and I fervently trust (and think
I can speak on this point with confidence for the entire Faculty) that this
may be the case throughout all the infinite future that endowments like
this in a country like ours have a right to expect. Although influences
are too subtly psychological to be traced, I am writing our history, and
find it a most inspiring theme, and I believe it adds already a very bright
and hopeful page to the records of higher education in the country, and
one which history will brighten to epochal significance. It has, on
the whole, in it one clear note, not of discouragement, but of hope and
confidence.
Have we duly considered, even the best of us, what a real university
is and means, how widely it differs from a college, and what a wealth
of vast, new, and in themselves most educative problems it opens? A
college is for general, the university for special, culture. The former
develops a wide basis of training and information, while the latter brings
to a definite apex. One makes broad men, the other sharpens them to
a point. The college digests and impresses second-hand knowledge as
highly vitalized as good pedagogy can make it, while the university.
64 Decennial Address.
as one of its choicest functions, creates new knowledge by research and
discovery. The well-furnished bachelor of arts, on turning from the
receptivity of knowing to creative , research, is at first helpless as a
new-born babe, and needs abundant and personal direction and encour-
agement before he can walk alone ; but when the new powers are once
acquired they are veritable regeneration. He scorns the mere luxury
of knowing, and wishes to achieve, to become an authority and not an
echo. His ambition is to know how it looks near and beyond the
frontier of knowledge, and to wrest if possible a new inch of territory
from the nescient realm of chaos and old night, and this becomes a new
and consuming passion which makes him feel a certain kinship with the
great creative minds of all ages, and having contributed ever so little,
he realizes for the first time what true intellectual freedom is, and attains
intellectual manhood and maturity. This thrill of discovery, once felt,
is the royal accolade of science, which says to the novice, stand erect,
look about you, that henceforth you may light your own way with
independent knowledge.
This higher educational realm is full of new " phenomena of altitude."
Faculties, instead of discussing and elaborating plans for commencement
ceremonies, hearing recitations, preparing and then reading the results
of examination papers, and carefully marking each individual exercise,
grinding in the old mills of parietal regulations, discipline, and the rules
of conduct needful to civilize the adolescent homo sapiens ferus, revising
requirements for admission, tacking and shaping the policy to gather
in more students and keep ahead of others in the struggle to get the best
connections with high and fitting schools, are occupied with far different
problems wherever the university spirit has a true and real embodiment.
Here first of all men must be discriminated, and great issues hang upon
the success in differentiating superior from indifferent young men. To
detect the early manifestations of talent and genius in the different fields
of intellectual endeavor, which some presidents and professors can, and
others so eminently lack the power to do, is the crucial doorkeeping
problem, where great privileges are to be awarded to great promise.
This is almost a life and career saving function for not only the young
professors and students, but for the university. Men are not equal, and
there must be a touchstone of mental aristocracy to discriminate $500
from $10,000 men.
Second, having selected these, the university should bestow freely its
Decennial Address, 55
needed aid and equipment, and the professor his choicest time and
knowledge, to perfect the precious environment by which the later stages
of growth, so liable to be lost, but on the full development of which
civilization itself hangs, and perfected. How to select the best, ripest,
and most fruitful topics for investigation requires an almost prophetic
ken in which differences in individual professors are immense. To study
individuals enough to adapt each theme to each personality is another
problem as new as it is delicate and difficult. The right solution of both
these is the large half of the work. The professor should give his best
suggestion, with no reservation for himself, and the able student should
not be an apprentice to serve his master, but should be distinctly
educated toward leadership himself from the first.
Having thus sown fit seed in fit soil, it must be watched and watered
with constant suggestion. The best and newest literature ; the most
effective and original apparatus that can be devised and if possible
made on the spot ; how to insure in the best form and place the speedy
publication of work and to bring it under the eye of all experts ; how
to avoid conflict and duplication ; how general or how special thesis sub-
jects and work should be to best combine the two sometimes more or
less divergent ends of discovery and education ; the requirements for
perhaps the choicest of all degrees, the doctorate of philosophy ; the best
modes of individual examination for it ; the number and relation of
subjects required ; the migration of students so as to insure not only
the best environment for each, but to give to professors not only in the
same department, but in different institutions, the same stimulus that
was felt when the elective system aroused the dry-as-dust professors to
unwonted effort lest their class-rooms be left vacant ; the kindred ques-
tion of the relative value of graduate work at home and abroad for
each student and for each department ; the fit federation of graduate
clubs and their thirty-five hundred members in the twenty-three Ameri-
can institutions now recognized in the yearbook ; the great problem of
printing and special journals together with interchange of monographs ;
the vast new library problems of purveying for highly specialized, but
very voracious, appetites which make the true university librarian a man
of far different order from others, and gives him a wealth of new prob-
lems of exchange, foraging, etc. ; to maintain the true relations between
lecture work and individual guidance while duly emancipating the pro-
fessors from the drudgery of elementary teaching and mass treatment
66 Decennial Address.
of great bodies of students ; the many and wide-reaching differences
between pure and applied science, and the practical methods by which
this distinction is maintained ; the danger of great aggregations of
students and the advantages of few ; the wide differences between the
new kind of professor needed in the university and those in the college,
where no provision is made for the advancement of learning, and the
tests are mainly pedagogic ; the even greater contrasts between scholar-
ship funds for the aid of poverty to professional careers, which are a
doubtful advantage even in colleges where they belong, and the true
university fellowship as above described ; the growing dominance and
need of expertness in all fields for which graduate departments must
prepare as well as for professorship alone, — these and many great ques-
tions like them, destined more and more to eclipse all others which are
just looming up, and for the irrigation and ventilation of which we hope
to establish here soon a new educational journal — such questions con-
stitute this opening field of what may be called the higher educational
statesmanship.
The hastiest glance at the situation on an anniversary like this would
be incomplete unless we turned toward the future. Our own needs here
are many and our wants urgent, but our faith is firm that in a community
like this the time will soon come when no wills will be drawn by wealthy
people without carefully considering the conclusion of the largest parlia-
mentary report ever made, which fills near a score of volumes, was many
years in the making, and describes all the public bequests ever made in
England. The substance of the conclusion of that most competent tribu-
nal that has ever spoken upon this subject is that the best of all uses of
public benefactions is, not for charity to the poor or even the sick and de-
fective, noble and Christlike as those charities are, not for lower education
or religion, beneficient as these are, but rather for affording the very best
opportunities for the highest possible training of the very best minds in
universities, because in training these the ivhole work of church, state, school,
and charity is not only made more efficient, but raised to a higher level, and
in this service all other causes are at the same time best advanced. I beg
respectfully, but with all my heart and mind, to urge this conclusion by
the highest human authority upon all those contemplating the bestow-
ment of funds where they will accomplish most for the good of man.
Our very best department is the library, which is so well endowed that
we do not at present need to expend the income of the fund. In this
Decennial Address. 57
respect the sagacity and benevolence of our Founder has been more than
sufficient for our needs up to the present time, and our most efficient and
courteous librarian has found many means and devices, new to the most
advanced library science, of bringing out its utmost efficiency for our
work, and of making it in all the pregnant sense of that word attractive
to all who once come within the sphere of its influence. His work amply
merits all the growing recognition that it and his rare personnel are
so steadily gaining. His special report contains new suggestions and
exjDeriences.
The large and new demands upon the Public Library caused by the
presence of an university for research which involved a material addition
to its work, which is likely to increase in proportion to our growth, should
be distinctly recognized. The special privileges needed by investigators
have often been a strain upon the capacity of both its officers, its methods
of administration and service, and the resources of its alcoves. The
Public Library has on the whole well met the test, and I desire here to
express, not only for myself personally, but for the other members of the
University our gratitude to the city, the Trustees, and particularly to the
accomplished head of the library itself, whose cooperation, with his able
corps of assistants, has been a factor in an important part of our work.
Our two strongest departments are mathematics and psychology.
These two, as has been often said, are the root and heart of all other
branches. Mathematics is the grammar of all the sciences that deal with
inanimate nature, and the study of the human mind and soul opens the
field where all animate nature celebrates her highest triumph and which
underlies all the humanities. While we could expend with profit much
more than at present, perhaps the entire resources of the University, upon
these departments, or perhaps, even upon each of them, they are best
equipped and least in immediate need. We have books, journals, pro-
fessors, means of speedy publication, and well-developed traditions, and
can claim, we think with modesty, to be doing creditable work.
Our greatest and most pressing need, according to the policy first
formulated of strengthening the departments already established before
founding new ones, is to enlarge the biology to an independent position,
with due provision for botany and the related subject of paleontology.
The foundations of a building for this group of studies is already laid
on the grounds, and its completion, with an endowment of $150,000 or
$200,000 with what we now have, would give us a strong department able
58 Decennial Address.
to compete successfully with the best ; perhaps we may sometime dedi-
cate such a building and department to the name of some honored public-
spirited citizen of Worcester.
Physics, like biology, now represented by a single able and promising
man, needs enlargement to the same degree, with an annex department
of astronomy and astrophysics, and for the same sum could, in addition
to what we now have, be put upon a creditable footing.
The chemical building, admirably planned after careful studies of all
the best in Europe, and well equipped, especially for organic work, has
no endowment, and needs for its full development the income of at least
a quarter of a million of dollars.
Anthropology, so greatly needed in this land, but so lacking in
academic installation and tradition here, is already a precious germ with
one worthy representative, has been cherished from the first with us,
and it, too, needs enlargement and independence.
If we pass over into the humanities, there are, of course, the two
great groups of philology and literature, ancient and modern, and a
historical group culminating in political economy, sociology, and a grand
department of international law, nowhere adequately represented in this
country, and for the establishment of which somewhere Senator Hoar,
acting president of the Board of Trustees, the first citizen of Massachu-
setts, competent to-day to fill any one of four professional chairs in any
university, in learning, experience, character, and position more nearly
the American Gladstone than any other, has been so distinguished an
advocate.
Education, now coming to be the largest philosophy of life and the
natural field of applied psychology, needs a more adequate representa-
tion, and with a quarter of a million of dollars for an ideal university
school for children, we would almost guarantee in five years to make
this place an educational Mecca, by short circuit methods now well
demonstrated but nowhere embodied, which would greatly increase the
efficacy and reduce the expense and ease the labor of the lower grades
of education in this country.
Our summer school has become one of the largest and highest
grade institutions of its kind in the country, and appeals especially to
heads of fitting schools, with whom it would be important for us to be
en rapport if we had a college ; to normal schools, whose faculties are
a growing field for the employment of our pedagogical graduates ; to
Decennial Address. 59
young instructors in colleges, superintendents, parents, etc. If our two
weeks could become a summer quarter counting toward a degree, and
if the summer school could be adequately endowed and furnished, with
the interest which one department of our work has already enlisted
among the teachers of our country, the best of whom could spend their
summer here in work, this, too, could be made an institution of which
any city or university might well be proud.
We urgently need without delay the means for establishing a univer-
sity printing office, where we can publish our journals at less expense and
do our own printing ; and if this should grow to larger dimensions and
develop a life of its own, that, too, might be welcomed.
These needs are all on the university plane, where the beginnings
already made are precious beyond words, wrought out as they have been
with so much pain and labor, and the highest effort of so many choice
spirits. May the day never dawn when this in our country most sorely
needed and prayerfully cherished academic tradition shall fade or be
broken. The investments of wealth and effort already made are too
great, and achievements already attained and future promise too bright,
to permit this ever to be an open question here.
Satisfied, yes proud, as we are to-day to submit to Worcester, to sister
institutions, and the country, the records of our work when compared with
our means, we have lived, and even now live and walk, let us confess it,
to a great extent in faith and hope, looking confidently to a future larger
than our past has been, with steadfast and immovable conviction that our
cause is the very highest of all the causes of humanity, but ready even
ourselves, if need be, to labor on yet longer in the captivity of straitened
resources, being fully persuaded that our redeemer liveth and that in due
time he shall appear.
THE DEPAETMENT OF MATHEMATICS.
By William Edward Story.
PAST AND PRESENT STAFF.
William Edward Story, Ph.D., Professor of Mathematics since 1889.
OsKAR BoLZA, Ph.D., Associate in Mathematics, 1889-92.
Henry Taber, Ph.D., Doceut in Mathematics, 1889-92; Assistant Professor
of Mathematics since 1892.
Joseph de Perott, Docent in Mathematics since 1890.
Henry S. White, Ph.D., Assistant in Mathematics, 1890-92.
FELLOWS AND SCHOLARS.
Henry Benner, Fellow in Mathematics, 1889-90.
L. P. Cravens, Scholar in Mathematics, 1889-90.
EoLLiN A. Harris, Ph.D., Fellow in Mathematics, 1889-90.
J. F. McCuLLOCH, Fellow in Mathematics, 1889-90.
William H. Metzler, Fellow in Mathematics, 1889-92.
J. W. A. Young, Fellow in Mathematics, 1889-92.
Levi L. Conant, Scholar in Mathematics, 1890-91.
Alfred T. De Lury, Fellow in Mathematics, 1890-91.
James N. Hart, Scholar in Mathematics, 1890-91.
Thomas F. Holgate, Fellow in Mathematics, 1890-93.
John I. Hutchinson, Scholar in Mathematics, 1890-91; Fellow in Mathe-
matics, 1891-92.
Frank H. Loud, Scholar in Mathematics, 1890-91.
N. B. Heller, Scholar in Mathematics, 1891-92.
LoRRAiN S. HuLBURT, Fcllow in Mathematics, 1891-92.
John McGowan, Scholar in Mathematics, 1891-92.
Ernest B. Skinner, Scholar in Mathematics, 1891-92.
L. Wayland Dowling, Scholar in Mathematics, 1892-93; Fellow in Mathe-
matics, 1893-95.
John E. Hill, Fellow in Mathematics, 1892-95.
Herbert G. Keppel, Scholar in Mathematics, 1892-93; Fellow in Mathe-
matics, 1893-95.
61
62 Department of
Thomas F. Nichols, Scholar in Mathematics, 1892-93 ; Fellow in Mathematics,
1893-95.
F. E. Stinson, Scholar in Mathematics, 1892-93; Fellow in Mathematics,
1893-95.
W. J. Waggener, Scholar in Mathematics and Physics, 1892-93.
Warren G. Bullard, Scholar in Mathematics, 1893-96.
Schuyler C. Davisson, Fellow in Mathematics, 1895-96.
Frederick C. Ferry, Fellow in Mathematics, 1895-98.
John S. French, Scholar in Mathematics, 1895-96 ; Fellow in Mathematics,
1896-98.
E. W. Rettger, Fellow in Mathematics, 1895-98.
fS. Edward Ryerson, Fellow in Mathematics, 1895-96. Died March 25, 1896.
Hugh A. Snepp, Scholar in Mathematics, 1895-96.
James W. Boyce, Fellow in Mathematics, 1896-99.
Herbert 0. Clough, Scholar in Mathematics, 1896-97.
A. Harry Wheeler, Scholar in Mathematics, 1896-99.
Lindsay Duncan, Scholar in Mathematics, 1897-99.
Frederick H. Hodge, Scholar in Mathematics, 1897-98 ; Fellow in Mathe-
matics, 1898-99.
Halcott C. Moreno, Scholar in Mathematics, 1897-98; Fellow in Mathe-
matics, 1898-.
Stephen E. Slocum, Scholar in Mathematics, 1897-98 ; Fellow in Mathematics,
1898-.
John N. Van der Vries, Scholar in Mathematics, 1897-98 ; Fellow in Mathe-
matics, 1898-.
Frank B. Williams, Scholar in Mathematics, 1897-98; Fellow in Mathe-
matics, 1898-.
Elwin N. Lovewell, Scholar in Mathematics, 1898-99.
Louis Siff, Scholar in Mathematics, 1898-99.
Orlando S. Stetson, Scholar in Mathematics, 1898-99.
SPECIAL STUDENTS.
George F. Metzler, Ph.D., Honorary Fellow in Psychology, 1891-92.
Calvin H. Andrews, Mathematics and Pedagogy, 1894-95.
Walter E. Andrews, Mathematics and Pedagogy, 1894-95.
Whole number of students in mathematics in 10 years 44
Aggregate attendance (including 4 who remain in 1899-1900) ... 83 years.
Average number of students per year 8
Average attendance per student 2 years.
Mathematics. 63
Mathematics occupies a peculiar position relatively to the arts and
sciences. It is, par excellence, an art, inasmuch as its chief function
is to solve problems, — not such examples as are given in the text-books,
and which serve only as exercises in the application of methods, but any
problems that may arise in human experience and for whose correct solu-
tion sufficient data are at hand. When any line of investigation, to
whatever subject it may refer, has been carried so far that exact reason-
ing may be applied to it, mathematics is the authority to which the
results of observation are submitted for the final determination of their
consistency and the conclusions that may be drawn from them, and fur-
nishes the means of applying these conclusions to the prediction of phe-
nomena not yet observed. No science and no branch of technology is
exact, that is, capable of predicting with certainty what will happen
under given conditions, unless it rests upon a mathematical foundation.
Astronomy, physics, and applied mechanics already have this foundation
to a considerable extent, while the other sciences are still in the inductive
stage, in which material is being collected with which, it is to be hoped,
such foundation will ultimately be laid. Mathematics is also a science,
inasmuch as it has accumulated a large body of systematic knowledge
involving and leading to the methods that it employs in its solutions.
These methods are of such a peculiar nature, differing so widely from
other methods, that a special course of training is requisite if any one
would learn to use them, and their number and variety have become so
great that a lifetime would not suffice to acquire familiarity with them
all. But new problems are continually arising and demanding new
methods, and we need, therefore, a body of men who shall devote them-
selves especially to the task of supplying this demand. While the col-
leges are engaged in general liberal education, teaching a variety of
subjects that develop the mental faculties (and no subject is more effi-
cient than mathematics for this purpose) and make the student acquainted
with his own tastes and powers, thus enabling him to determine the life-
work for which he is best fitted, it is the special function of the university
to extend the limits of human knowledge, and to train those who have
unusual intellectual talents to employ them to the best advantage. We
believe this object is best accomplished by an institution devoted solely
to it, and whose teachers' energies are not diverted by the lower, though
no less important, aims of the college.
When the policy that should characterize this University was under
64 Department of
discussion, the first point decided was that its work should be strictly-
post-graduate, and that it should not compete with other institutions
in the work that is generally recognized as undergraduate. In accordance
. with this principle, the mathematical department fixed its standard of
admission so as to require such a knowledge of mathematics as can be
obtained in the average American college, and laid out upon this foun-
dation a curriculum of its own, as extensive and as thorough as circum-
stances allowed. In elaborating the details of this curriculum, we have
kept in mind the fact that those who pursue post-graduate studies in
pure mathematics almost always look forward to careers as professors
in colleges or other higher institutions of learning ; and we have taken
the view that, other things being equal, the ideal teacher is a master
of his subject, not only conversant with the general principles of all its
more important branches, the problems that have arisen in each, the
methods that have been devised for the solution of these problems, and
the results that have been obtained, but also unbiassed, ready and sound
in judgment, and actively engaged in scientific research. We believe
that the training that is best adapted to produce efficient specialists is
also the training that is best adapted to produce efficient teachers of
specialties.
While desirous of supplying all possible facilities to those who wish to
pursue studies in special branches, and to those who, already occupying
permanent positions, have but a limited leave of absence, we have made
it our chief object to provide a thorough training for those who, having
just completed a college course, have not yet entered upon their life-work.
This provision consists of such courses of lectures, seminaries, and indi-
vidual assistance as should enable a faithful student endowed with the
proper natural ability to satisfy the requirements for the degree of Doctor
of Philosophy at the end of his third year with us. The requirements
for this degree have been determined by our conception of the ideal
teacher, as already stated. To acquire the necessary breadth of knowl-
edge of mathematics as a whole, the candidate is expected to attend,
during his first two years, specified courses of lectures on the general
principles, methods, and results of all the more important branches of
pure mathematics, to supplement these lectures by private reading, and to
take an active part in the seminary. In the seminary, a special topic,
more or less directly connected with the subject of some lecture, is as-
signed, from time to time, to each student, who is required to read it up
Mathematics. 65
and make an oral report upon it before the class. Advanced courses of
lectures on special subjects that vary from year to year are also given,
and each candidate for the degree is expected to attend a number of such
courses. The student spends the greater part of his third year in the
original investigation, under the constant personal guidance of one of the
instructors, of a topic of his own selection. In preparing for this inves-
tigation, he is required to make a practically complete bibliography of the
subject, and to read all the more important available articles that have
been written on it. The results of the investigation, embodied in a dis-
sertation suitable for printing, must be submitted to the instructor under
whose direction the work was done, and must receive his approval before
the candidate will be admitted to the final examination for the degree.
This approval will not be given unless the dissertation is satisfactory in
form and completeness and the results are sufficiently novel and impor-
tant to constitute a real contribution to science. The dissertation is, in
fact, the main criterion by which the candidate is judged, and no amount
of other work will compensate for its defects. The ability of our grad-
uates to carry on research and the excellence of the work actually done
is assured by the regulation that each dissertation accepted by us as
worthy of the degree shall be printed with the explicit approval of a
member of our Faculty. It is evident that, whereas any one that has the
necessary preparation and taste for mathematics may profit by the advan-
tages here afforded, only those who have a certain amount of mathematical
genius can secure the degree.
In making appointments to fellowships and scholarships we have
endeavored to maintain the same high standard. We are on the lookout
for mathematical geniuses ; but it is difficult to determine from the evi-
dence of others whether candidates come up to our standard or not ; so
that we have adopted the general policy of giving the best appointments
to those only that have been with us for at least one year, and about
whom we are in position to judge for ourselves. Of course, this policy
could not be carried out during the earlier years of the University, and
its effect is apparent in the fact that, whereas seventy-five per cent of the
students that entered the mathematical department during the first three
years remained with us but one year, only twenty per cent of those that
have been admitted during the last seven years left at the end of their
first year. I do not mean to imply that those who left before completing
our course were inferior in ability to those who remained three years, but
66 Department of
we desire particularly to encourage men who can and will go forward to
the degree.
Nearly all of those who have studied mathematics with us have
adopted teaching as a profession, two-thirds are now members of college
faculties, and one-third are engaged in higher school work. Those who
have received the doctor's degree have generally secured at once desir-
able positions in which to begin their life-work, and most of them have
already acquired for themselves, by distinguished ability, very decided
influence in the institutions with which they are connected. Of those
who have left without the degree fully one-half ought to have continued,
and would have done so but for want of pecuniary means ; and we have
been obliged to turn away many men of very great promise on account of
our inability to assist them in providing the means of subsistence during
the unproductive period of student life. We could employ for fellow-
ships, with decided advantage, ten times the amount now at our disposal.
Although, as I believe, students will find here a broader post-graduate
curriculum in mathematics and greater personal attention from the in-
structors than at any other university in the country, we need greater
facilities to make our course what it ought to be. Four-fifths of the in-
struction in the department is now given by two men, and we are com-
pelled to give in alternate years lectures on fundamental subjects that
ought to be given every year. As I have said, we lay great stress upon
the ability of our students to investigate ; but this faculty can be fully
developed only under the personal guidance of one who is himself in the
habit of investigating and who has the facilities and opportunities neces-
sary for such work. A teacher's usefulness is greatly increased b}^ the
inspiration that comes from a personal identification with his subject,
from the fact that he has ideas of his own about it, and that he has ex-
tended it by his individual exertions ; and tlie investigator can have no
greater incentive to search for new results than the opportunity to pre-
sent his thoughts and discoveries to an intelligent and appreciative class
in the lecture-room. But the necessity of teaching many subjects simul-
taneously distracts the mind and is fatal to research. The ideal condi-
tions for an instructor in an institution like this would be those under
which he could teach one subject at a time, and that a subject that he
was himself developing, and follow this subject with his class to such
a point as to bring into evidence the scope and importance of his own
work. To apply this method to the courses that are actually given here
Mathematics. 67
would require the services of three additional instructors in mathematics.
We are actually laboring under the disadvantage that some of the im-
portant branches now taught by us are not of such paramount interest
to any one of our instructors as to be the subject of his personal investi-
gation. We are compelled to restrict ourselves to elementary courses in
many branches that ought to be carried to a much higher point, and to
omit altogether from our consideration applications of mathematics to
statistics, to the arts, and to other sciences. Applications to physics re-
ceive the attention of the physical department, to be sure, but the mathe-
matical department ought to do much more than it is at present able to
do in preparing students for higher work in physics. The number of
instructors necessary for such advanced work as we do is not to be deter-
mined by the number of our students, but by the number of subjects
taught.
Again, every expert investigator finds himself continually obliged to
spend much time in details that could just as well be worked out by a
younger man, to whom such work would be of immense advantage, not
only as an exercise in the practical application of methods, but also as
furnishing the opportunity for a prolonged study of the workings of an
investigator's mind ; and example is worth more than precept in the
development of the faculty of investigation. We ought to have the
means of retaining our best graduates for a year or two as personal assist-
ants to the instructors, during which period they might also be gaining
experience in the class-room by teaching a few hours a week under the
supervision of one of the regular instructors. Such work is not drudgery,
and would be, I think, sufficiently attractive to an ambitious young man
to induce him to remain with us on a moderate stipend while he is wait-
ing for such appointment as may seem to him desirable.
It is almost universally assumed that a mathematician needs no mate-
rial equipment other than brains, with, possibly, a few books. However
true this assumption may have been some decades ago, — and I fancy that
its truth then rested solely upon the difficulty of procuring such equi]3-
ment, — it is not true now, as must be apparent to any one who studied
carefully the German educational exhibit at the World's Fair in Chicago.
Ten years ago our department started out with a fair nucleus for a
mathematical library and a moderate collection of models, to which we
have not been able to make many additions. We have very few of the
older mathematical works that illustrate the history of the subject, and
68 Department of
we need particularly complete sets of many important mathematical jour-
nals and the transactions of learned societies. In these journals and
transactions have appeared most of the original investigations to which,
as investigators ourselves, we have continual occasion to refer, both for
suggestions and to avoid apparent plagiarism and the unnecessary dupli-
cation of research. We should also be greatly assisted in our class-work
by a more complete collection of models.
In short, what I have in mind as a model mathematical department
for post-graduate work would have, say, four professors and assistant
professors, each having his personal assistant, and at least two instructors
of lower grade for the more elementary work, and would be provided
with a complete mathematical library and -with all the apparatus that it
is now possible to prociu'e, with suitable provision for tlie purchase of
new books and apparatus as they appear in the market.
These schemes are not incapable of realization, although, perhaps,
opposed to the traditions of education in this country. This University
has never had any traditions excepting such as were based upon high
ideals. Its mathematical department was not modelled after that of any
other institution, but was determined by the conception of what would
constitute perfection in such a department. We have always lived up to
our ideals, in so far as Ave have done anything, without regard to consid-
erations of material interest. We are not here to do what is done else-
where, and we do not acknowledge that it Avould be best for us to do what
other institutions, in their experience, have thought wisest. We propose
to adopt no temporary policy that we shall sometime want to abandon,
confident that the ideal university of the future will be ideal from the
very root and not a graft upon inferior stock.
When the doors of the Universty were first opened to students, in the
fall of 1889, the mathematical staff consisted of William E. Stor}-, Pro-
fessor, Oskar Bolza, Associate, and Henry Taber, Decent ; a year later it
was increased by the appointment of Joseph de Perott, Doceut, and
Henry S. Wliite, Assistant ; and in 1892 Drs. Bolza and White resigned
their positions to accept Associate Professorships in the University of
Chicago and Northwestern Universit}^, respectively, and Dr. Taber was
promoted to an Assistant Professorship, thus leaving the department with
practically the same teaching force as it had during the first year.
The instruction has been given by lectures, seminaries, and individual
conferences. The number of lectures (of fifty minutes each) was sixteen
Mathematics. 69
a week the first year, nineteen and twenty a week in the second and
third years, respectively, and about fourteen a week, on the average, each
year since. In some years courses of lectures on certain mathematical
subjects having important physical applications have been given by
Assistant Professor Webster of the Department of Physics.
The subjects of the lecture courses given during the ten years include
the following : —
1. The History of Arithmetic and Algebra among various peoples from the
earliest times to 1650 a.d.
2. Theory of Numbers (introductory).
3. Theory of Numbers (advanced).
4. Numerical Computations.
6. Theory of Quadratic Forms.
6. Finite Differences.
7. Probabilities.
8. Theory of Errors and the Method of Least Squares.
9. Theory of Functions of a Real Variable.
10. Linear Transformations and Algebraic Invariants (introductory).
11. Theory of Substitutions, with applications to algebraic equations (intro-
ductory).
12. Theory of Transformation Groups.
13. The Application of Transformation Groups to Differential Equations.
14. Finite Continuous Groups.
15. Klein's Icosahedron Theory.
16. Simultaneous Equations, including Eestricted Systems.
17. Theory of Functions of a Complex Variable, according to Cauchy, Rie-
mann, and Weierstrass (introductory).
18. Definite Integrals and Fourier's Series (introductory).
19. Ordinary Differential Equations (introductory).
20. Ordinary Differential Equations (advanced).
21. Partial Differential Equations (introductory).
22. Elliptic Functions, according to Legendre and Jacobi (introductory).
23. Weierstrass's Theory of Elliptic Functions.
24. Elliptic Modular Functions.
25. Abelian Functions and Integrals.
2,6. Theta-Functions of Three and Four Variables.
27. Riemann's Theory of Hyperelliptic Integrals.
28. Riemann's Surfaces and Abelian Integrals.
29. Conic Sections by modern analytic methods (introductory).
30. Quadric Surfaces by modern analytic methods (introductory).
31. General Theory of Higher Plane Curves (introductory).
32. Plane Curves of the Third and Fourth Orders.
70 Department of
33. General Theory of Surfaces and Twisted Curves (introductory).
34. Surfaces of the Third and Fourth Orders.
35. Twisted Curves and Developable Surfaces (advanced).
36. Applications of the Infinitesimal Calculus to the Theory of Surfaces.
37. Rational and Uniform Transformations of Curves and Surfaces.
38. Enumerative Geometry.
39. Analysis Situs.
40. Hyperspace and Non-Euclidean Geometry.
41. Modern Synthetic Geometry (introductory),
42. Quaternions, with applications to geometry and mechanics.
43. Multiple Algebra, including matrices, quaternions, " Ausdehnungslehre,"
and extensive algebra in general.
44. Symbolic Logic.
Courses designated as " introductory " are given at least as often as
every other year, and attendance on tliem is required of all candidates
for the degree of Doctor of Philosophy that take mathematics as their
principal subject. The other courses, intended primarily for the more
advanced students, have been given less frequently and vs^ith particular
reference to the suggestion of topics for original investigation.
In connection with his lectures, Assistant Professor Taber has con-
ducted a weekly seminary for students in their first or second year, for
the purpose of cultivating in them an active attitude toward the subjects
treated, instead of the passive attitude usually resulting from hearing
lectures. Topics related to those of the lectures have been discussed
by the students, and their work has been criticised both with reference
to rigor of demonstration and manner of presentation. In this way some
of the advantages of the laboratory and the practice school are brought
into the field of mathematics. Professor Story, with the assistance of
the other instructors, has directed the more advanced students individ-
ually in the systematic investigation of special topics that promised to
afford opportunity for the discovery of new results and methods, — a task
that has sometimes required the professor to hold weekly three-hour
conferences with each of four students during nearly the entire academic
year ; but we believe the results have justified this unusual expenditure
of energy.
The average annual number of students taking mathematics as their
chief study has been about eight, the average duration of their residence
was about two years, and more than one-third of them have received (or will
undoubtedly receive) the Doctor's degree, which is a decided improve-
Mathematics. 71
ment in every respect over the record of the first three years. The pub-
lished investigations of these students are enumerated in the Bibliography
at the end of this volume.
The researches of an instructor in an institution of this kind are not
to be judged solely by the number and magnitude of his printed papers,
as many of them are naturally turned over, in a more or less incom-
plete form, to his pupils for further investigation and more adequate
presentation ; at least it seems most natural and desirable that an in-
structor should suggest to his pupils subjects for investigation on which
he has himself worked, and for whose treatment he has found adequate
methods.
My chief subjects of investigation have been : —
1. Hyperspace and Non-Euclidean Geometry.
2. Algebraic Invariants.
3. Curves on Ruled Surfaces, and Restricted Equations.
4. The History of Mathematics prior to the invention of the infinitesimal
calculus, and
5. A Mathematical Curriculum for Primary and Secondary Schools.
I have developed systematically the general theory of space of any
number of dimensions from assumptions that are precisely analogous to
those on which the scientific treatment of threefold space is usually based,
and which we recognize as the results of experience. In accordance with
this general theory, I have thoroughly investigated the properties of loci
of the first and second orders and some special loci of higher orders.
The introduction of the most general kind of measurement has then led
me to an equally thorough study of parallel and perpendicular loci, the
curvature of loci, areas, and volumes in the most extended sense. The
first part of these results has already appeared in the Mathematical
Review^ and I hope to publish the remainder within a short time.
Ever since the appearance of Clebsch's " Theorie der binaeren alge-
braischen Formen," toward the end of the year 1871, when I was study-
ing in Berlin, I have taken a lively interest in the theory of algebraic
invariants, — an interest that was greatly augmented by my association
with Sylvester at the Johns Hopkins University in 1876. I had thought
all along that there ought to be a direct process by which all such inva-
72 Department of
riants could be obtained, but my efforts to find it had failed. A course
of lectures on invariants that I have given every year or two since the
opening of Clark University caused me to renew my attempts, and the
classic paper of Hilbert in the 36th volume of the Mathematische
Annalen, in which a process devised by Mertens (and which I regarded
as indirect, inasmuch as it involved quantities extraneous to the matter
in question) suggested a new line of research, which happily led at length
to the long-sought direct process. I then applied this process, as Hilbert
had applied Mertens's process, to the proof of Gordon's theorem that all
the invariants of any finite system of quantics of finite orders can be
expressed rationally in terms of a finite number of such invariants.
These results were published in the Mathematische Annalen and in the
Proceedings of the London Mathematical Society. I have spent much time
in trying to find, by means of the process, an extension of Cayley's for-
mula for the number of linearly independent ground-forms of a single
binary quantic (extended by Sylvester to any system of binary quantics)
to the case of quantics involving three or more variables, but so far with-
out success.
In my lectures on surfaces of higher orders and twisted curves I have
paid particular attention to the algebraic curves that lie upon a given
algebraic surface. If the given surface is ruled, the curves on it can be
classified in such a way that certain problems relating to a curve can be
solved when the class of the curve is known. My investigations in this
direction have been communicated to my students, some of whom have
already solved such problems. In connection with my investigations on
twisted curves, I have also made a systematic study of restricted equa-
tions, and have carried the determination of the orders of such systems
much farther than had been done before.
I have lectured at various times on the early history of mathematics,
with special reference to the development of arithmetical and algebraic
symbolism, and have collected a large number of systems of such symbols,
which I hope sometime to utilize for a monograph on the subject.
In connection with a course of lectures delivered for two years at the
Summer School, I arranged a mathematical curriculum for primary and
secondary schools, which will be published when I can find the leisure
necessary to prepare the explanatory text.
At my request. Assistant Professor Taber has furnished the material
for an account of his personal researches, which involves such a complete
Mathematics. 73
and excellent history of the theory of matrices that it seems to me inad-
visable to abbreviate it ; I therefore append it to this report at length, for
the benefit of those readers who may be interested in the subject.
Dr. Taber's researches have been devoted to the development of the
theory of matrices, and its application to bilinear forms, multiple algebra,
and theory of finite continuous groups. The calculus or theory of matrices
was invented by Professor Cayley (see his " Memoir on the Theory of
Matrices," Phil. Trans.., 1858), and has proved an instrument of great
power in the theory of linear transformation, bilinear forms, and for the
investigation, generally, of the projective group. i In order to explain
the work done by Dr. Taber in this direction, a few words of explanation
will be necessary to describe the work done by Cayley and others.
Associated with any linear substitution
n
c/ =S\<^ijXj (i = 1, 2, ••• w)
is the bilinear form -^ = / / ('(■ij^iVj-i which may be regarded as repre-
senting this substitution, or vice versa ; and, in the theory of matrices, we
do not need to distinguish between this linear substitution and the asso-
ciated bilinear form, or between either and the matrix ( . , '^"
\i,j = 1, 2, ...w
n rt
common to both. If now B denotes the bilinear form y \ ^ya^t^^? or
1 1 ^
its associated linear substitution, A±B will denote the bilinear form
n n
y^ y^ (ajj + hjj)Xii/p or its associated linear transformation ; and AB
will denote the bilinear form / ^y ^\/ ^ cLii^ki]^%y}-> oi' its associated
linear substitution (obtained by the composition of the linear substitutions
A and B). Equivalence between two bilinear forms or linear substitu-
1 By means of this calculus very important results have been obtained by Cayley himself,
by Sylvester, Frobenius, Toss, Weyer, Study, and others ; and, by methods essentially simi-
lar, Kronecker obtained important theorems on the orthogonal group to which reference is
made below.
74 Department of
tions, A and B, is denoted by writing A = B. Further, in what follows,
I will denote the identical transformation, represented by 2^.a^.yo and
A-^ the form, or substitution, satisfying the symbolic equation AA-^
n n
= A-^A = I; A will denote the bilinear form V" >^ aj,a:,y,, transverse
or conjugate to A =y^ y" ayX^i/j, and \A\ will denote the determinant
1 1
of the matrix A. A is said to be symmetric if A = A, and alternate, or
skew symmetric, if A=: — A.^
Cayley was, perhaps, led to the invention of this calculus by his
researches upon orthogonal substitution, Crelle (1846), Vol. 32. For
in Crelle, Vol. 50, three years before the publication of his memoir on
matrices, he expressed the results of these researches in the notation of
matrices. Thus Cayley showed that the general expression for the proper
orthogonal substitution in n variables is (J— ^)(7+ -5)-\ where B
denotes an arbitrary alternate, or skew symmetric, linear substitution ;
and this expression gives Cayley's determination of the coefficients of a
proper orthogonal substitution in n variables as rational functions of the
essential parameters, |^w(w — 1) in number.
Again, in his " Memoir on the Automorphic Linear Transformation of
a Bipartite Quadrate Function" {Phil. Trans., 1858), Cayley showed that
the general automorphic linear transformation (linear transformation into
n n
itself) of a symmetric (alternate) bilinear form A = y \ ^tpiVj with
1 1
cogredient variables and of non-zero determinant, may be represented by
(A + X^~^(A — X), where X is an arbitrary alternate (symmetric) bi-
linear form. This expression gives in the first case (when A is symmet-
ric) Hermite's determination of the general proper automorphic linear
transformation of a symmetric bilinear form, and, in the second case
(when A is alternate), Cayley's determination of the transformation into
itself of an alternate bilinear form. Further, in this same memoir Cay-
ley showed how to reduce, to the solution of a system of n^ linear equa-
tions, the rational determination of the n^ coefficients of the automorphic
linear transformation of a general bilinear form A (neither symmetric
nor alternate) with cogredient variables and of non-zero determinant.
Namely, he showed that the general formula for such a substitution is
i In the first case aji = ay, in the second aji = — Oy (i, j = 1, 2, ••• n).
Mathematics. 75
{A + X)-\A-X), where X satisfies the condition (Jl)-^ X + A-^X = 0.
This result includes the determination of the general automorphic trans-
formation of A^ when A is symmetric and when A is alternate. It also
includes Cayley's determination of the coefficients of an orthogonal substi-
tution to which it reduces when A = I.
In what follows Cr will denote the group of proper automorphic linear
transformations of A (the a;'s and ^'s being cogredient), and Gr' the proper
orthogonal group. A transformation T oi Cr (or of 6r') is termed singular
if —1 is a root of its characteristic equation (namely, ] T— pl\ =0);
otherwise, non-singular. Every non-singular transformation of group G-
(or (^') is given by Cayley's formula, and may be termed a Cayleyan
transformation of the group. ^ No singular transformation of group G is
given by Cayley's expression or determination. But for A alternate, also
when A is neither symmetric nor alternate provided ( J. ± J. | ^0, Dr.
Taber showed in 1894 {Proc. Am. Acad. Arts and Sciences, Vol. 29) that
group G is generated by the Cayleyan transformations of the group, —
each transformation T of this group being obtained by the composition of
a finite number of Cayleyan transformations. In the same paper Dr. Taber
also showed that the sub-group of orthogonal transformations of G- is,
similarly, generated by the non-singular orthogonal transformations of
this sub-group, when A is alternate, and when A =^ ± A provided
\A± A\ =^0.
This theorem is similar to a theorem relating to the orthogonal group
(group G'} established by Kronecker in 1890 (" Ueber orthogonale Sys-
teme," Sitzungsherich. d. Freuss. Akad.}, who showed that this group
is generated by the Cayleyan transformations of the group, each trans-
formation T of this group being obtained by the composition of two
Cayleyan transformations, — the coefficients of each of the Cayleyan
transformations being rational functions of the coefficients of T.
In 1895 (Math. Ann., Vol. 46) Dr. Taber showed that, if A is real and
alternate, every real transformation T oi G can be obtained by the com-
position of two real Cayleyan transformations of this group. This
theorem was obtained independently and extended widely by Dr. Loewy,
who in 1896 (^Math. Ann., Vol. 48) showed that, if A is irreducible
1 For the case in which A is symmetric, the determination of the coefficients of T", given
by Cayley's formula, is properly Hermite's •, but it is not convenient to distinguish here
between this case and the other two cases, namely, when A is alternate, or is neither
symmetric nor alternate, when the determination is Cayley's.
76 Department of
(which case includes that in which A is alternate), every transformation
of Q-^ real or imaginary, can be obtained by the composition of two
Cayleyan transformations of the group, and that, therefore, when A is
irreducible, there is no transformation of the kind termed by Foss
essentially singular} that is to say, which cannot be obtained by the com-
position of two non-singular, or Cayleyan, transformations.
For a reducible form A not every singular transformation of G- can be
obtained by the composition of two Cayleyan transformations of this
group. Nevertheless, Dr. Taber showed in 1897 {Math. Review^ Vol. 1)
that in every case the Cayleyan transformations of Gr form a group by
themselves ; that the composition of any number of Cayleyan transforma-
tions of Gr results in a transformation that can be obtained by the
composition of two Cayleyan transformations of this group; and that thus
the composition of Cayleyan transformations never gives rise to an
essentially singular transformation.
It is to be noted that from Cayley's formula for a transformation T of
Cr^ namely,
T= iA -f Xy (^ - X) = (J- ^-iX)(J4- A-'xy\
we derive X=A(1 - T)(l + T)-^;
and, therefore, the parameters, namely, the coefficients of X, which enter
into the determination of T, can be expressed rationally in the coefficients
of T and of A.^ Similarly, in the memoir by Kronecker mentioned above,
he has shown that the coefficients of the two Cayleyan transformations,
whose composition gives the general transformation T of group Gr', can be
expressed rationally in the coefficients of T. For A real, alternate, and
orthogonal. Dr. Taber gave, in the paper in the Mathematische Annalen
mentioned above, the determination of the coefficients of the two Cayleyan
transformations C^ and O^, whose composition gives any real transforma-
tion T of Gr, as rational functions of the coefficients of T and of A. This
determination of (7j and C^ he has since extended to the case in which T
is imaginary, and A any alternate bilinear form.^
Dr. Taber has pointed out that the transformations of Gr, both when
A is irreducible and when A is reducible, are in general of two essentially
1 Abhand. d. k. Bayer. Akad. d. Wiss., II. CI., XVII. Bd., II. Abth. 1890, p. 77.
2 Between these parameters ■when A is neither symmetric nor alternate n^ equations
persist.
2 See papers to appear in Proc. Am. Acad, of Arts and Sciences, Vol. 35.
Mathematics. 77
different kinds. The difference between the two kinds of transformations
of Gr is given by the following theorem : —
(I.) If we designate a transformation of group G as of the first or sec-
ond kind according as it is or is not the second power of a transformation
of the group^ then every transformation of the first kind is the rath power
of a transformation of the group, for any positive integer m, and can he
generated hy the repetition of an infinitesimal transformation of the group.
A transformation of the second kind, hy definition not an even power of any
transformation of the group, is always the (2m + l)"* power of a transforma-
tion of the group for any odd exponent 2m + 1. But no transformation of
the second kind can he generated hy an infinitesimal transformation of the
group.
(II.) Every Cayleyan transformation of group G is a transformation
of the first kind ; whereas, a non- Cayleyan transformation is, in general, of
the second kind.^
Dr. Taber has also given the conditions necessary and sufficient that
a transformation T of group Gr may be of the first kind for the case in
which A is symmetric (which includes the case when ^ = /, in which case
G becomes Gr'), and for the case when A is alternate. ^
Dr. Taber has shown that, if A is neither symmetric nor alternate and
1 This was proved for the orthogonal group in 1894, Bull. Am. Math. Sac, Vol. 3. At
the conclusion of this paper it was stated that a precisely similar theorem held for what
is here designated as group G. In the Math. A7171., 1895, "Vol. 46, the theorem was proved
for group Gf when A is alternate; for the case in which A is symmetric, in the Proc.
Lond. Math. Soc, 1895, Vol. 26; and for the general case, in the Math. Beview, 1897,
Vol. 1.
2 For the orthogonal group, to which G reduces when A = I, the conditions necessary and
sufficient that a transformation shall be of the first kind were given by Dr. Taber in a com-
munication to the American Academy of Arts and Sciences, March, 1895. (See Proceedings,
Vol. 30, p. 551.) The necessity and sufficiency of these conditions was afterwards shown in
Proc. Lond. Math. Soc, 1895, Vol. 26, and the theory for the orthogonal group extended
to group G for A symmetric. It was not explicitly stated in this paper that the conditions
given for the orthogonal group hold for G when A is symmetric, being so obvious a conse-
quence of the considerations adduced. This does not seem to have been recognized by Dr.
Loewy, who refers to this paper but gives the necessary and sufficient conditions. Math.
Ann., Vol. 48, when A is symmetric as an extension of Dr. Taber's theorem for group G'.
For A alternate the necessary and sufficient conditions were given by Dr. Taber in a
communication to the American Academy of Arts and Sciences, January, 1896. (See Pro-
ceedings, Vol. 31, p. 349.) The necessity of these conditions has previously been shown by
Dr. Taber in the Math. Ann., Vol. 46. In Vol. 49 (1897), Dr. Loewy gave the conditions as
sufficient, undoubtedly without knowledge of Dr. Taber's priority in the statement of
this theorem.
78 Department of
|J[ ± AM 0, group 6r contains no transformation of the second kind. This
theorem leads, for the case mentioned, to the following rational represen-
tation of any transformation of this group, namely,
where (^A)~'^ X -\- A~'^ X = 0. Moreover, Dr. Taber has shown that the
sub-group of orthogonal transformations of Cr contains no transformation
of the second kind when A is alternate.^
The determination of the congruent transformations between two bi-
linear forms is the natural generalization of the problem to determine the
automorphic linear transformations oi A. A determination of the trans-
formations between A and B depending on the solution of a single equa-
tion of degree n has been given by Dr. Taber (^Mathematical Review^ Vol.
1, 1897), which holds for any case whatever in which A and B are both
symmetric or both alternate.
The theory of matrices, or bilinear forms, is closely related to the
theory of Hamilton's linear vector functions. In the American Journal
of Mathematics^ Vol. 12, Dr. Taber has given a development of the
theory of matrices, proving many of the fundamental theorems, from the
point of view of Hamilton's theory.
One of Sylvester's most important contributions to the theory of
matrices was a general formula, given in the Comptes Rendus, Vol. 94, 1882,
expressing any power, integral or fractional, of the bilinear form or matrix
A a.s a polynomial in A of degree n—1. Thus, ii B = A^^, where fi is any
fraction, and if p^, p^, . . . p^ are the roots of the characteristic equation
of A, we have
B = 2/)'^ (^ - P.J'yC^ - PJ) -"{A- pj)
^ (Pl-p2)iPl-p3)-- 2 also, the special linear homogeneous group in n variables is
continuous only in the neighborhood of the identical transformations.
For two variables, Study gave the conditions necessary and sufficient that
a transformation of this group may be generated by an infinitesimal trans-
formation of this group. Dr. Taber gave, in 1896 (^Bull. Am. Math. Soc,
Series 2, Vol. 2, p. 231), these conditions for n variables ; also the conditions
necessary and sufficient that a transformation of the special linear homo-
geneous group may be the mth power of a transformation of this group.
From these conditions it appears that the nth. power of any transforma-
tion of this group can be generated by an infinitesimal transformation of
this group; and that the transformations of this group can be divided into
as many genera as there are prime factors of n. Thus, if 8 is a prime
factor of n, there are transformations of this group whose w/Sth power, but
no lower power, can be generated thus.^
Dr. Taber has shown that the following groups are not continuous,
except in the neighborhood of the identical transformations, namely, the
group Gr, mentioned above, for A symmetric or alternate, and in general
when A is neither symmetric nor alternate, provided either | J^ 4- J. | or
1 J. — ^ I is equal to zero.^ For all these groups the infinitesimal trans-
formations satisfy Lie's criterion.
Dr. Taber has also shown that the following groups are continuous,
namely, group Gr when \A±A\=^0, the sub-group of orthogonal trans-
formations of 6r, for A alternate, and the group of automorphic linear
n n
transformations of a bilinear form A=y^ P^'if^iVi'^ of non-zero deter-
1 1
minant, the rr's and y's being contra-gredient.^
1 Leipzige Berichte, 1892.
2 See Proc, Vol. 30, p. 551. This result is referred to above on p. 77.
8 See Bull. Am. Math. Soc, Series 2, Vol. 3, p. 9. * See p. 77, note 1.
6 See p. 77 above, also Proc. Am. Acad. Arts and Sciences, Vol. 31, p. 181.
G
82 Department of
Investigations upon the continuity of the groups in two and three
variables have been carried on under Dr. Taber's supervision by certain
of the students in the mathematical department. Dr. E. G. Rettger has
investigated the continuity of all the two and three fold groups, fifty-nine
in number, enumerated by Lie, Continuierliche Gruppen, pp. 288 and 519 ;
and shown that twenty-one of these groups are discontinuous. ^ Mr. F.
P. Williams has investigated the continuity of certain groups of the
plane, not treated by Mr. Rettger; and Mr. S. E. Slocum has pointed
out the nature of Lie's error in his demonstration of the fundamental
theorem referred to above. ^
If a system of real infinitesimal transformations satisfy a modification
of the Lieschen criterion, Lie states that they generate a real continuous
group, that is, a group with continuous parameters, each transformation of
which can be generated by an infinitesimal transformation of the group.
But this theorem is subject to certain modifications.
Dr. Taber has shown that the group of real proper orthogonal trans-
formations is continuous; 3 also that in the groups of real transforma-
tions enumerated below not every transformation can be generated by an
infinitesimal transformation of the group, namely, —
the real projective group,*
the general and special real linear groups,
the general and the special real linear homogeneous groups,
the sub-group of real transformations of Cr, for A real and either
alternate or symmetric.
Further, that if G denotes either of the groups just enumerated, the first
part (I) of the theorem of p. 77 holds. And he has given the con-
ditions necessary and sufficient, for each of the first three of the groups
just enumerated, that a transformation of this group may be generated by
an infinitesimal transformation of this group. ^
Let G denote a group generated by the composition of r one-fold
1 Proc. Am. Acad, of Arts and Sciences, Vol. 33.
2 See papers to appear in Vol. 35 of the Proc. Am. Acad, of Arts and Sciences.
8 Bull. Am. Math. Soc. for July, 1894. See also Proc. Am. Acad, of Arts and Sciences,
Vol. 27, p. 163.
4 For the real projective group this was first pointed out by Professor H. B. Newson,
Kansas Univ. Quart., 1896.
6 B7iU. Am. Math. Soc, Series 2, Vol. 2, p. 228 et seq. Also Proc. Am. Acad, of Arts
and Sciences, Vol. 31, p. 336, and Vol. 32, p. 77.
^y\
Mathematics. 83
groups (each containing the identical transformation), namely, Gri<^\ G/^\
•••G/''\ whose infinitesimal transformations satisfy Lie's criterion. It may
happen that a transformation T of one (or more) of these one-fold
groups, as G/'^\ combined with any transformation of another of the one-
fold sub-groups, as Gi^"^ (in particular with the infinitesimal transforma-
tion of Gi^"^), results in a transformation that cannot be generated by an
infinitesimal transformation of G. Any such transformation T, together
with any transformation T of G that cannot be generated by an infinitesi-
mal transformation of this group, may be termed singular; all other
transformations of G will then be non-singular. In a paper, of which an
abstract was read at the February meeting of the American Mathematical
Society, 1899, Dr. Taber showed that, if G is a sub-group of the projective
group, any singular transformation of G can always be obtained by the
composition of two non-singular transformations of G ; and moreover
that, if T is any singular transformation of G not generated by an infini-
tesimal transformation of G, a transformation Tp^ generated by an infini-
tesimal transformation of G, can always be found which can be made to
approach as nearly as we please to T by taking p sufQciently small, so
that limp^o Tp = T.
DEPARTMENT OF PHYSICS.
By Arthur Gordon Webster.
STAFF.
Albert Abraham Michelson, Ph.D., Professor of Physics, 1889-92.
Arthur Gordon Webster, Ph.D., Docent in Mathematical Physics, 1890-92 ;
Assistant Professor of Physics, 1892-.
FELLOWS AND SCHOLARS.
Louis W. Austin, Scholar in Physics, 1890-91 ; Fellow, 1891-92.
Frank K. Bailey, Scholar in Physics, 1898-99.
William P. Boynton, Scholar in Physics, 1894-95 ; Fellow, 1895-97.
Arthur L. Clark, Scholar in Physics, 1896-97 ; Fellow, 1897-98.
D. Ellis Douty, Scholar in Physics, 1898-99.
William F. Durand, Scholar in Physics, Nov.-Dec, 1889.
Thomas W. Edmondson, Fellow in Physics, 1894-96.
Benjamin F. Ellis, Scholar in Physics, 1892-93.
T. Proctor Hall, Scholar in Physics, 1890-91 ; Fellow, 1891-93.
fBENjAMiN C. HiNDE, Fcllow and Assistant in Physics, 1892-93. Died Feb.
6, 1894.
Richard J. Holland, Ph.D., Honorary Fellow in Physics, 1893-94.
James Edmund Ives, Scholar in Physics, 1897-98 ; Fellow, 1898-.
Sidney J. Lochner, Scholar in Physics, 1892-93.
Alexander McAdie, Fellow in Physics, 1889-90.
Alfred G. Mayer, Assistant in Physics, 1889-90.
EoLLA R. Ramsey, Scholar in Physics, 1898-99.
Stanley H. Rood, Scholar in Physics, 1893-94.
t Clarence A. Saunders, Fellow in Physics, 1892-95. Died Dec. 19, 1898.
Benjamin F. Sharpe, Fellow in Physics, 1894-96 ; 1897-98.
Robert R. Tatnall, Ph.D., Honorary Fellow in Physics, 1897-98.
Samuel N. Taylor, Fellow in Physics, 1893-96.
Frank L. 0. Wadsworth, Fellow in Physics, 1889-90; Assistant, 1890-92.
Arthur J. Warner, Scholar in Physics, 1889-90.
Albert P. Wills, Scholar in Physics, 1894-95 ; Fellow, 1895-97.
85
86 Department of
SPECIAL STUDENTS.
Ervin W. Howard, 1892-93.
Albert B. Kimball, 1893-94.
William Nelson, 1892-93.
Joseph 0. Phelon, 1892-93.
Arthur L. Rice, 1892-93.
Stanley H. Rood, 1892-93.
Clayton 0. Smith, 1892-93.
Hugh M. Southgate, 1892-93.
The work of a Department of Physics in a university at the present
time may be best understood after a brief survey of some of the chief
achievements of the science during the present century. As we in this
country have our attention called more frequently to the achievements of
applied than to those of pure science, it is worth while to dwell somewhat
upon the influence of pure science upon applied, and upon its contribution
to the progress of civilization. At the beginning of the century, the
various subjects that together make up the science of Physics were in a
very imperfect state. Of heat, light, sound, electricity, and magnetism,
little that we now accept was known, while of that little still less had
been applied to practical matters. The science of mechanics, upon which
the whole superstructure of physics must inevitably rest, had indeed been
set upon a firm basis by the immortal Newton, while its principles had
recently been formulated by the distinguished mathematician Lagrange,
in a way so broad and powerful that it has not since been improved upon.
The science of pure mathematics had of course arrived at a high degree
of perfection, and many of the leading mathematicians had devoted their
best efforts to the subject of mechanics. But while a large number of
investigators had laid the foundations of our present knowledge by the
method of experiment, the habit of questioning nature, instruments in
hand, had as yet by no means become general. This habit of direct
experimental research is certainly in large degree to be credited to the
present century. Without stopping to enumerate the leading achieve-
ments of physics during the century, let us take as illustrations a few
leading cases. Nothing has, perhaps, done more to change the face of
the earth, from the point of view of man, than the invention of the steam-
engine and of the railway thereby made possible, of the telegraph and
telephone, while the transmission of energy by electricity bids fair to
rival them in importance. Let us then briefly consider what led to these
Physics. 87
inventions. At the beginning of the century it was universally held that
heat was a substance, which could be put into, or removed from, ordinary
matter. It is to the experiments of one of our own countrymen, the
celebrated Count Rumford, that was due the original assault on this
notion, the last blow at which was delivered by the Englishman, James
Prescott Joule, in his great discovery of the mutual convertibility of heat
and mechanical work, and of the doctrine of the Conservation of Energy.
This discovery, so simple that it may be understood by every one, namely,
that for whatever we do we get an exact equivalent, neither more nor
less, is the fundamental truth of physical science. It is in physics the
supreme achievement of the century. Until it was discovered, a true
understanding of the principles of the steam-engine could not be arrived
at, although the way had been prepared by the theoretical work of a
French engineer, the illustrious Sadi Carnot. To Carnot and Joule, then,
we owe the two laws of the new science of Thermodynamics, or the
relations between heat and work, which lie at the basis of all steam,
gas, oil, or other heat engines, as well as of all freezing machines, and
of transmission or storage of energy by means of compressed gases.
It would be well, therefore, for all intending investors in new and
promising compressed or liquid air companies, no matter how attrac-
tively advertised, to find out what thermodynamics has to say of the
propositions advanced.
The foundations having been laid by the experimental work of Joule
and the theoretical work of Carnot, the required knowledge of the prop-
erties of steam and other vapors used in engines and cooling machines
was furnished by a masterly series of experimental researches of the dis-
tinguished French physicist, Henri Regnault, who was set at work by
the French government, and whose work has ever since been classical.
No engineer could to-day design an engine without making use of the
data thus furnished.
Let us pass on to the telegraph. Here again it was the patient work
of our countryman Henry, working quietly with purely scientific aims in
his little laboratory in Albany, — it was Henry's investigations on the
electromagnet that made feasible the invention by Morse of the recording
telegraph, which is still in use more than any other system all over the
world. It is, however, when we come to the great question of submarine
telegraphy that we see most emphatically the practical contribution of
pure science. The problem of telegraphing through an insulated wire
88 Department of
immersed in water is totally different from the corresponding one for a
land line, and for years seemed hopeless of solution. The construction of
a cable reaching from Europe to America was such a costly undertaking
as to deter the most venturesome capitalists, unless they could be pre-
viously furnished with a reasonable guarantee of success. It was here
that the work of William Thomson, to-day known as Lord Kelvin, our
greatest living physicist, furnished the necessary assurance. Taking up
the purely mathematical problem of the propagation of an electrical
impulse in a submarine cable, he for the first time set its mode of work-
ing in a clear light, and by means of his solution predicted that the
American cable, if constructed in accordance with his specifications, was
bound to work. Led by faith in this statement, Cyrus W. Field col-
lected the money, the cable was laid, and the cable worked. That the
first cable of 1858 lasted but little more than a month was due to the
unfortunate mode of working adopted by the chief electrician, a so-called
practical man, who would however have been much better off if he had
possessed the theoretical knowledge of Professor Thomson. To-day
twelve working cables span the Atlantic, representing an investment of
eighty-five million dollars. Is this too large a sum to credit to theoretical
physics ? The problem of telegraphy that is to-day most interesting is
that of telephoning across the Atlantic, and I feel no hesitation in saying
that before this can be accomplished a large amount of theoretical research
will be necessary, together with such experimental work as may be car-
ried on in laboratories like ours, and is now being carried on by Professor
Pupin of Columbia University, before a single dollar is sunk under the
sea.
The question of electric power transmission is one whose genesis is
easy for all to remember. All do not remember, however, that far from
electrical science being, as the newspapers maintain, in its infancy, the
laws governing our dj^namos and motors were discovered in the first quar-
ter of the century, mainly by two princes among workers in physics, the
Frenchman Ampere and the Englishman Faraday. The achievement of
Ampere in discovering the laws of the action of electrical currents in
producing magnetic forces upon each other was, in its combination of
mathematical and experimental brilliancy, one of the most remarkable
achievements in the annals of science. Still more important practically
were the discoveries of Faraday, who deduced unaided all the laws upon
which the working of dynamo-machines depends.
Physics. 89
Another illustration of our point is the wireless telegraphy of Mar-
coni, of which we hear so much in the newspapers to-day. What the
newspapers do not tell us is that the electrical waves made use of in tele-
graphing across the English Channel were predicted in a paper published
in 1864 by the great English physicist, Clerk-Maxwell, who completely
remodelled the theory of electricity as it then existed. Twenty-three
years afterward his predictions were experimentally verified by Hein-
rich Hertz, who thus rendered the practical results of Marconi possible.
These researches, far-reaching as were their practical results, were
carried on by purely scientific workers, solely for the interest that they
presented by increasing our knowledge. This should always be the posi-
tion of the scientist, for, if he turns aside, attracted by the seductive
paths of moneymaking, he is almost sure to lose the prize of the great
discovery.
Let us now turn to the present means of advancing our scientific
knowledge. It is not to be overlooked that many of the great discoveries
above mentioned were made with very simple apparatus and with very
modest facilities. When we see the very primitive instruments of
Ampere, Henry, and Faraday, we are led to wonder that they could pro-
duce such accurate results. The days of such work are however over.
It is now possible to add to the knowledge already so richly harvested
only by experiments of the most careful nature and by measurements of
great refinement, involving often complicated and expensive apparatus.
It is for this reason that the great laboratories have sprung up, which we
find in such large numbers both in this country and in Europe. Until
about a quarter of a century ago there were none. It had, however, come
to be recognized that, in order to make an investigator of a student, it was
necessary not only that he should hear lectures, but that he should him-
self have practice in experimentation and in the making of exact meas-
urements. For these purposes, courses of instruction in physical measure-
ments were planned, and laboratories where they might be practically
carried on were erected. One of the earliest of these teaching labora-
tories was that of the Massachusetts Institute of Technology, presided over
by Professor Pickering, now director of the Harvard College Observatory.
Later came the laboratories at Yale, Harvard, Cornell, Johns Hopkins,
Chicago, and Columbia, costing between one and two hundred thousand
dollars each. In each case is to be added the sum of from twenty to
fifty thousand dollars for equipment with apparatus. During the same
90 Department of
time a large number of physical laboratories have been built in Europe,
some of them involving a still larger expenditure of money, notably the
one at Ziirich, in which the Swiss government invested about a quarter
of a million of dollars. At all these laboratories both teaching and the
performance of research were contemplated, and an idea of the results
achieved may be obtained from the statement that from the Johns Hop-
kins laboratory have issued upwards of five hundred papers, and from those
of Harvard and Cornell in the neighborhood of one hundred each.
Besides these institutions so immediately connected with teaching,
another type of laboratory has made its appearance within the last ten
years. Of this the most conspicuous example is the German Imperial
Physico-technical Institute, which is separated from teaching, and is
intended solely for the performance of research, especially for the per-
formance of such measurements as would require resources exceeding
those possessed by private or university laboratories. The work per-
formed in this great institution has been of the highest class, and has
drawn the attention of other governments to the desirability of establish-
ing such national laboratories, with the result that England has now fol-
lowed the example of Germany, though upon a smaller scale. A further
example is presented in the Faraday-Davy research laboratory in London,
the gift of a private individual, Mr. Ludwig Mond, a successful technical
chemist, who in this most appropriate manner recognized the debt of
applied to pure science by the foundation of a laboratory devoted espe-
cially to the furtherance of research in physical chemistry.
What, then, has been the position occupied by Clark University in
the ranks of this march of progress? Naturally it has been a modest one.
Without a separate laboratory building, with a small equipment, and a
staff reduced to the minimum, it has of course not been able to rival in
quantity the work of its greater predecessors. It may, however, be re-
marked that limitations of size are not necessarily limitations of quality.
The relatively small number of students coming here have received greater
individual attention than would have been possible at more crowded
institutions. In spite of our limited space and equipment, it has alwaj'^s
been found possible to put in possession of each student apparatus suitable
for the performance of original research, and to give him what is more
important, minute personal direction and encouragement. In this manner
students coming to us from the colleges, often ill prepared for the severe
mathematical work so necessary to the physicist, but to which they have
Physics. 91
been little accustomed, are rapidly pushed on, and recover their places in
line.
The Department of Physics was, during the first three years of the
history of the University, under the direction of the distinguished physi-
cist, Professor Albert A. Michelson, who was then called from it to take
the conduct of the larger department at the University of Chicago.
During his stay at Clark Professor Michelson was engaged in research
in the field of optics, inventing a method for the study of radiations from
both celestial and terrestrial bodies, by means of an instrument devised
by him, and depending on the interference of light. By means of this
ingenious and elegant method, valuable results in connection with spec-
troscopy and the measurement of small astronomical objects were obtained,
upon which a number of papers were published. Before the termination
of his labors here. Professor Michelson was invited by the International
Bureau of Weights and Measures to make, by means of his new apparatus,
a comparison between the international standard of length and the length
of a certain wave of light, thus establishing a natural unit of length.
A new apparatus having been designed and constructed under the direc-
tion of Mr. F. L. O. Wadsworth, preliminary observations were made at
the University, and, obtaining leave of absence. Professor Michelson and
Mr. Wadsworth proceeded to Paris, where the experiment was carried
out with marked success, constituting a performance in metrology that
will undoubtedly become classical.
During his conduct of the department. Professor Michelson delivered
usually one lecture a week, on various subjects concerning the Theory
of Light, especially connected with his own researches. Upon the be-
ginning of the incumbency of the writer, a consecutive course in theoreti-
cal or mathematical physics was planned, and has been regularly delivered,
the course covering five lectures a week for a term of two years. Per-
haps the principal claim that can be made for the department is the stress
that has been laid upon the subject of mathematical physics, undoubtedly
the most difficult branch for the student, and one which has not yet be-
come popular in this country, yet which is of prime importance, and
without which none can hope to reach the highest position in the science.
A gratifying testimonial to the truth of this contention is furnished by
the recent arrival at the University of two students, both doctors of phi-
losophy from German universities, who have come here impressed with
their need for more study of mathematical physics.
92 . Department of
In this course the several parts of the subject are treated in regular
order, as parts of a logically connected whole, starting from the funda-
mental basis of dynamics. The course is attended by every student in
the department, and he is held responsible for a knowledge of its subject-
matter in his examination for the doctor's degree. It is safe to say that
in this respect the requirement for the degree is not exceeded at any
institution in the country. The regular courses of the cycle are as
follows : —
1. Dynamics. — General Methods, Canonical Equations, Methods of Hamil-
ton and Jacobi, Systems of Particles, Eigid Bodies.
2. Newtonian and Logarithmic Potential Fmictions, Attraction of Ellipsoids.
3. Elasticity, Hydrodynamics, Wave and Vortex Motion, Dynamical Basis
of Sound and Light.
4. Electricity and Magnetism.
5. Optics, Physical and Geometrical. — Elastic and Electromagnetic Wave-
theories.
6. Thermodynamics, Thermo- and Electro-Chemistry, Kinetic Theory of
Gases.
7. The Partial Differential Equations of Mathematical Physics.
Laplace's Equation, Equation of Thermal and Electrical Conduction,
Equation of Wave-motion, Telegrapher's Equation, Developments in
Series, Legendre's, Laplace's, Bessel's, and Lame's Functions.
Besides these, it has been the practice to deliver each year at least one
new course, so that certain courses are delivered occasionally. A num-
ber of courses in pure mathematics have also been delivered at various
times, supplementing those of the mathematical department. These
extra courses have been as follows : —
Dynamics of Cyclic and Oscillatory Systems, with applications to the The-
ory of Electricity, Sound, and Light.
Comparison of the Theories of the Ether.
Theory of Functions of Real and Complex Variables.
Definite Integrals, Fourier's Series.
Ordinary Differential Equations.
Linear Differential Equations, particularly of the second order.
Elliptic Functions (notation of Weierstrass), with certain physical applica-
tions, including the theory of the Top.
Orthogonal Surfaces and Curvilinear Coordinates, and their applications.
Of the lectures in the above course one volume, on the theory of elec-
tricity and magnetism, has been published, and has apparently been of use
Physics. 93
to teachers in other institutions. Other volumes are in course of prep-
aration.
In addition to the lectures, a weekly colloquium or meeting for the
discussion of questions in experimental physics has been held. Here
reports upon current articles in the leading physical journals are deliv-
ered by the students, and the most important classical determinations are
also taken up, in order that familiarity may be gained with the methods
of the masters of research. These meetings have been of great help to
students, and have given them practice in presenting their ideas before
an auditory. Beside the work of instruction, research has been carried
on in the laboratory by every student and the professor. When a stu-
dent arrives at the University he is at first put at work upon a subject
designed to test his powers, and to give him familiarity with the princi-
ples of exact measurement. When he has shown his ability, he is encour-
aged to undertake a research for himself, under the continual guidance
of the professor. In this way the undertaking of research before the
necessary experience has been gained is prevented, and the publication of
trifling or ill-considered articles is discouraged. As a rule a student
devotes at least two years to the preparation of a doctor's dissertation.
Thus the number of published researches is limited. Six doctor's disser-
tations have been published, and another is ready for publication. Be-
side these a number of other researches, both theoretical and experimental,
have been published, one of which latter was honored by a substantial
money prize in an international competition. These researches have not
been confined to any one branch of physics, but have dealt with molecular
physics, electricity, magnetism, and sound. Most of them have been of
such a nature that the student was forced, not to work in a single narrow
specialized line, but to gain a large amount of experience in various parts
of the subject. A research of this nature is of far more value to the
student than one performed simply for the purpose of gaining him a de-
gree, and dealing only with a narrow range of ideas.
The subjects of the dissertations have been as follows : Mr. T. P. Hall
worked out a new method for the determination of the surface tension
of liquids, suggested by Professor Michelson, in which the pull upon a
film of liquid was directly weighed by a balance. Mr. C. A. Saunders
made a determination of the velocity of electric waves in parallel wires,
by a direct method, in which the wave-length and period of the waves
were measured, the latter by photographing the periodic spark giving
94 Department of
rise to the wave by means of a revolving Foucault mirror, the wave-
length by measuring the length of the wires, which was made to be a
quarter wave-length by means of electrical resonance. This research
demanded a large amount of time, and elaborate apparatus. In connec-
tion with the revolving mirror a convenient method devised by the writer
for maintaining a constant angular velocity was made use of. Mr. T. W.
Edmondson determined the distances necessary for the formation of a
spark at varying potentials between spheres of different sizes in air and
in various insulating liquids, the potentials being measured by means of
an absolute attracted disk electrometer. Mr. S. N. Taylor made a com-
parison between the important cadmium element devised by Weston with
the well-known Latimer Clark standard cell, in which he compared their
electromotive forces by means of an electro-dynamometer, obtaining
results agreeing remarkably well with those obtained by a quite different
method at the German Reichsanstalt. Mr. W. P. Boynton carried out
an experimental verification of the theory of the action of the peculiar
high-frequency induction coil invented by Elihu Thomson and Tesla,
which had never been mathematically treated in detail, not to say experi-
mented upon. This work involved a large number of difficult measure-
ments, including the currents, potentials, and frequencies of oscillation
involved in the working of the apparatus. The results were in excellent
agreement with the theory, considering the difficulty of the experiments.
Mr. A. P. Wills undertook the development of a new and ingenious
method, suggested by the writer, but materially improved by him, for
measuring the magnetic permeability of substances, whether magnetic
or diamagnetic, differing so little in this respect from air as to be not
amenable to the usual methods. By means of a simple arrangement
involving the use of a slab of the substance suspended in the field of a
powerful electromagnet with peculiarly shaped pole-pieces, the effect was
measured by the pull on a sensitive balance, so that accurate results were
easily obtained. This work of Mr. Wills resulted in his being received
into the laboratory of Professor du Bois, one of the leading authorities in
magnetism, in Berlin, where he performed a number of other interesting
pieces of research in the same subject. Mr. B. F. Sharpe spent the
greater part of three years in developing a method devised by the writer
for the measurement of the intensity of sound, a measurement of more
than ordinary difficulty. The instrument depends upon the application
of Michelson's interference methods to the measurement of the very small
Physics. 95
distances involved in the vibration of plates set in motion by sound.
The interference bands observed in an interferometer, of which one mova-
ble mirror is fixed upon a plate of thin glass forming the back of a reso-
nator, are observed through a moving telescope, or have their motion
photographically registered. In this manner a very sensitive means of
measurement is obtained, and it is possible to measure sound in absolute
measure, even when it is rapidly varying in intensity, a result not before
attainable. The applications of this method which have been already
suggested are very numerous and important.
Mention should not be omitted of the labors of Mr. F. L. O. Wads-
worth, who, as assistant to Professor Michelson, by his untiring energy
and especial skill in the design and construction of apparatus, contributed
in large measure to the success of the researches of the latter.
The most important experimental paper published by the writer was
a determination of the period of electrical oscillations in a circuit contain-
ing a condenser and a coil, the purpose of the investigation being to
verify the formula of Lord Kelvin, all the constants of the apparatus
being measured in absolute measure. For the research a new instru-
ment was devised capable of breaking two electrical contacts at instants
separated by a very small measured interval of time. The instrument
was very sensitive, permitting the appreciation of less than a millionth of
a second. This research, already begun in the attempt to improve a
method for the determination of the ratio of the two units of electricity,
was found to correspond to a question proposed by a committee in Paris
having in charge the prize established by Elihu Thomson, and being sub-
mitted for the competition, was awarded the prize of five thousand
francs.
During the first year of the history of the University a considerable
sum was spent upon a set of meteorological instruments, especially for
the study of atmospheric electricity, and research was begun in this
subject by Mr. Alexander McAdie, of the Weather Bureau, who has now
become a recognized authority upon the subject of lightning discharges.
This work came to an end upon the departure of Mr. McAdie from the
University, but it might with advantage be resumed, with the addition of
observations of phenomena of terrestrial magnetism.
In concluding this report, it will not be out of place to speak of the
needs and ideals of the department for the future. It is extremely
desirable that the courses in mathematical physics be repeated every year,
96 Department of
instead of once in two years as at present, this being as often as the time
and strength of a single lecturer will allow him to cover the subject. If
this were done, students could then begin each year at the most appropri-
ate part of the course, without waiting for the natural beginning in their
second year, as is now necessary for those students coming in alternate
years. Even more desirable than aid in instruction is assistance in
experimental work. Research in the laboratory can be carried out much
more economically if a number of assistants are available to carry out
details, leaving the professor free for the more important work of
planning and personally attending to the more difficult parts of the
work.
One of the most important adjuncts of the department, the workshop,
in which a skilled mechanic is constantly employed in the construction of
apparatus for research, is capable of great extension of facilities. The
absolute necessity of this work cannot be too strongly emphasized, and
the department could even at the present moment profitably employ two
or three men instead of one. Research in physics demands instruments
of great exactness, complication, and cost, so that the maintenance of
such a department in which research is done entails more expense than
that of any other scientific department, except engineering. Each partic-
ular research requires much of the apparatus used in it to be particularly
designed, so that in view of the frequent changes necessitated before
it exactly fits its purpose, and of the fact that it is impossible as a rule to
find it kept in stock by dealers, it is more economical to have apparatus
constructed in the workshop of the department under the eye of the
professor than to have it made elsewhere.
In designing an ideal laboratory, one of the first things to be con-
sidered would accordingly be a workshop well equipped with modern
machine tools, with an ample and convenient source of power for driving
them, and with a large electric storage plant, both as a source of supply
for investigations in electricity and magnetism, and for the purpose
of furnishing power in smaller quantities than would require the main
supply. An optical shop would greatly increase the capability of a
laboratory for work in light. That such a suggestion is not extrava-
gant is shown by the fact that Professor Michelson's new and ingenious
echelon spectroscope was constructed by methods devised by him in the
workshop of his laboratory, and could not have been so well constructed
anywhere else. The famous diffraction gratings of Professor Rowland
Physics. 97
have for years furnished a further striking example, forcing European
physicists to send to this country for their supply.
A laboratory should be provided with the means for the determina-
tion of the important physical constants of nature, such as the velocity
of light and of electric waves, of the Newtonian constant of gravitation,
of the mechanical equivalent of heat, and of the fundamental relation
between electricity and magnetism, the so-called " v " of Maxwell.
Thus it would be possible not only to initiate students into the most
precise methods, but even to hope to improve upon classical determina-
tions. Ample facilities should be always at hand for the comparison
and calibration of the important physical standards of measurement, such
as those of length, time, mass, of electrical and magnetic quantities.
The small facilities in this line possessed even by our national govern-
ment are in painful contrast to what is seen in Europe, particularly in
the German Imperial Physico-technical Institute, in which a million or
more of dollars is invested.
Beside the matter of accurate measurements of well-known phe-
nomena lies the wider field of research in fields which are sure to prove
fertile in new discoveries. The great domain of electrical waves, a
creation of the last decade, although already exploited by scores of
observers, is still full of interesting problems, that are sure to yield a
rich reward to those who shall devise more perfect methods of investiga-
tion. The field of spectroscopy, whether in its terrestrial or celestial
applications, is an enormous one. To this is to be added the study of
radiations in general, of whatever character. The recent discovery of
Rontgen was followed quickly by hundreds of researches bearing on the
rays discovered by him, resulting in the discovery of several closely
allied forms of radiation, and in a greatly increased interest in the
phenomena of electrical discharges in vacuum tubes. Here remain a
multitude of questions to be decided. The nature of cathode and of
Rontgen rays remains to be settled, and will probably be one of the
achievements of the early years of the next century. Research on the
liquefaction of gases, and on the properties of bodies at temperatures
not far removed from the absolute zero, until recently limited to a few
observers possessing far more than ordinary facilities, will soon furnish
a field for the labors of many, who will undoubtedly be well repaid.
The many relations predicted by the recent applications of thermody-
namics, especially in the domain of physical chemistry, remain in large
98 Deimrtment of Physics.
measure to be verified. The science of meteorology, hitherto largely
an empirical one, remains to be put upon a satisfactory theoretical basis,
and presents many problems for the physicist to attack in his laboratory.
The same may be said of geology, which is, for example, vitally con-
cerned with the thermal properties of rocks and other materials of the
substance of the earth, and with many problems concerning the physics
of the earth's crust.
The foregoing is but a brief sketch of the field of physical investiga-
tion. The enthusiasm of one devoted to the performance of research,
and considering it the most attractive form of human endeavor, would
enable him to enlarge the subject over many more pages than are here
available. The field is enormous, and each new discovery leads to new
paths of inquiry. It is obvious that, in order to enter upon these
attractive fields of work, one must be provided with large resources.
Is it unreasonable to look forward eagerly to the day when Clark
University shall possess a well-equipped physical laboratory building,
fitted out with the utmost that our knowledge can suggest, in which
we may hope to contribute our just share toward the enlargement of
the boundaries of science, and thus to the welfare of humanity?
DEPAKTMENT OF BIOLOGY.
By Clifton F. Hodge.
PAST AND PRESENT STAFF.
Charles 0. Whitman, Ph.D., Professor of Animal Morphology, 1889-92.
Franklin P. Mall, M.D., Adjunct Professor of Anatomy, 1889-92.
Henry H. Donaldson, Ph.D., Assistant Professor of Neurology, 1889-92.
Warren P. Lombard, M.D., Assistant Professor of Physiology, 1889-92.
Clifton F. Hodge, Ph.D., Assistant and Fellow in Neurology, 1889-91 ;
Assistant Professor of Physiology and Neurology, 1892-.
J. P. McMuRRiCH, Ph.D., Docent in Morphology, 1889-91; Assistant Pro-
fessor of Morphology, 1891-92.
Adolf Meyer, M.D., Docent in Psychiatry, 1895-.
fGEORGE Baur, Ph.D., Docent in Comparative Osteology and Paleontology,
1890-92. Died June 25, 1898.
John C. Cardwell, M.D., Assistant in Physiology, 1889-91.
Sho Watase, Ph.D., Lecturer and Assistant in Morphology, 1890-92.
FELLOWS AND SCHOLARS.
Franklin W. Barrows, M.D., Fellow in Physiology, 1893-94.
Charles L. Bristol, Fellow in Morphology, 1891-92.
Hermon C. Bumpus, Fellow in Biology, 1889-90.
Albert C. Eycleshymer, Fellow in Morphology, 1891-92.
Charles L. Edwards, Ph.D., Fellow in Morphology, 1890-92.
E. R. GuRLEY, M.D., Fellow in Biology, 1895-96.
Homer Gage, M.D., Honorary Scholar in Anatomy, 1889-90.
Edwin 0. Jordan, Fellow in Morphology, 1890-92.
Herbert P. Johnson, Fellow in Morphology, 1891-92.
F. C. Kenyon, Ph.D., Fellow in Biology, 1895-96.
tW. E. Lockwood, M.D., Fellow in Physiology, 1891-92. Died June 23, 1897.
Frank E. Lillie, Fellow in Morphology, 1891-92.
A. D. Mead, Fellow in Morphology, 1891-92.
William S. Miller, M.D., Honorary Scholar, 1889-90; Scholar in Anatomy,
1890-91 ; Fellow in Anatomy, 1891-92.
James E. Slonaker, Fellow in Biology, 1893-96.
100 Department of
Colin C. Stewart, Scholar in Physiology, 1894-95 ; Fellow in Physiology,
1895-97.
Frederick Tuckerman, M.D., Ph.D., Fellow in Anatomy, 1889-90,
William M. Wheeler, Fellow in Morphology, 1890-91 ; Assistant, 1891-92.
SPECIAL STUDENTS.
James Jenkixs, Special Student in Biology, 1894-95.
Preston Smith, Special Student in Physiology, 1899.
W. G. Watts, Laboratory Steward and Special Student, 1889-91.
HISTORICAL REVIEW.
It will be seen from the above list of appointments that the depart-
ment was organized to cover animal biology. Animal morphology, ver-
tebrate anatomy, physiology, comparative osteology and paleontology, and
neurology, which forms the natural transition to psychology, and has
been classed in that department, formed a compact and well-selected
group with which to begin work. This organization was still further
strengthened by a strong force of organic chemists in this fundamental
department.
A good share of the equipment necessary for different lines of research
work already in progress or planned by the different appointees had been
ordered during the previous summer, so that the work of the whole
department began practically with the opening of the University. Zeiss
microscopes of the most approved patterns and with full complements of
apochromatic eye-pieces and objectives, Thoma microtomes, together with
those of Minot, the Minot-Zimmerman, Schanze, and others, complete assort-
ments of chemical reagents, stains and laboratory tools, apparatus and
glassware, all were supplied with liberality. Abundant and suitable
rooms were also placed at the department's disposal in the main univer-
sity building. Two large rooms and a convenient dark room for photo-
graphic purposes on the fourth floor were assigned to physiology and
were devoted to laboratory and lecture-room with w^orkshop equipped with
lathe and tools for working both wood and metals. Four large rooms on the
third floor were arranged to accommodate anatomy and morphology for
laboratories, lecture-room and drafting room ; and, in addition, four small
rooms adjoining supplied office and library for the head of the depart-
Biology. 101
ment, and private laboratories for three of the docents and assistants.
Two rooms on the second floor, adjoining the psychological department,
were assigned to neurology, the one for private laboratory and office of
Assistant Professor Donaldson, the other for his general laboratory. All
of these rooms were equipped with water and gas, and some with hoods to
render them the most convenient and ideal laboratories possible, and the
morphological laboratories were furnished with five large aquaria, the
largest being eight feet in length, all supplied with running water, and a
large number of smaller glass aquaria which made it possible to keep all
sorts of aquatic animals both summer and winter.
While the chief emphasis both as to equipment and disposition of the
instructor's time was given to research, the side of instruction toward
breadth and depth of view, so necessary to the highest type of investiga-
tion, was not neglected. Models of the brain (Auzoux, Aeby, Ziegler),
as well as Ziegler 's models of classic embryological types, and a complete
set of Leuckart & Nitche's zoological charts, and an extensive library
of wall charts copied from various monographs and text-books, all
these, supplemented by anatomical and zoological specimens, gathered
as rapidly as possible to form the nucleus of a museum, imparted the
best possible quality to the work of instruction. In fact, instruction
and research began together and went hand in hand, the one aiding the
other.
Professor Whitman immediately began courses of lectures funda-
mental to the doctrine of evolution. The first of these treated,
entirely from original sources, the historical development of Compara-
tive Anatomy, beginning with its renaissance in the works of Marco
Aurelio Severino (" Zootomia Democritsea, id est Anatome generalis totius
animalium opificii libris quinque distincta," 1645), and bringing the sub-
ject down to the discussions, just preceding the Darwinian epoch,
between Etienne Geoffroy Saint Hilaire and Georges Cuvier (1830).
As Professor Whitman himself announced with reference to this early
course : " Attention will be directed particularly to the origin and
development of historic ideas, tendencies, methods, and schools, as pre-
sented in the early iatric and physiological stages of Zootomy ; in the
works of Haller, Geoffroy, and Cuvier ; in the ' Anatomic Philosophique '
of the French, and the ' Naturphilosophie ' of the Germans ; in the
doctrines of the ' Scale of Nature,' ' Unity of Composition,' and of
' Types ' ; in the hypotheses of Evolution and Epigenesis, in Homology
102 Deioartment of
and Teleology, etc. The biographical side of the subject will also
receive due consideration, especially in the cases of such representa-
tive men as Malpighi, Swammerdam, and Leeuwenhoek of the seven-
teenth century, and Haller, Buffon, Daubenton, Linn^, John Hunter,
Camper, Vicq-d'Azyr, Kielmeyer, Geoffroy, and Cuvier of the later
period."
A second and third historical course was devoted respectively to the
subjects of Generation and Comparative Embryology. These courses,
compactly coordinated, and following logically on the development of
comparative anatomy, were likewise worked up from original sources
in Aristotle, Harvey, John Hunter, Wolff, Von Baer, and others, and
led naturally up to the modern doctrines of heredity as developed by
Lamarck, Darwin, Weismann, and their followers. Especially in the
course in Comparative Embryology, the present phase of biological work,
cytological technique and terminology, were fully treated, together with
matters of interest in recent discussions as to origin and maturation
of ova and spermatozoa, phenomena of fecundation, cleavage of the
o\Tim, with comparison of different types of cleavage and experimental
researches in cleavage, gastrular and pre-gastrular stages, their differ-
ent types and derivations, germ layers, the trochosphere, budding and
fission, formation of the embryo in invertebrates and vertebrates, to-
gether with that of double and multiple monsters, and, finally, the
course culminated in a discussion of the origin and significance of
metameric segmentation.
Simultaneously with these courses Dr. McMurrich lectured on the
coelenterates and platyhelminths, sifting all discoverable evidences for
coelenterate ancestry of the worms, the origin of segmentation, and
the significance of ccelenterate structure in gastrular stages of vertebrate
embryos. Dr. Baur on the side of paleontology discussed the osteology
of reptiles and mammals, living and extinct. Dr. Bumpus also lectured
on the affinities of the Crustacea.
For two years, as a means of uniting still further instruction and
research, and of keeping all members of the department in touch with
one another, an active biological club was maintained. Monthly meet-
ings were held, and at each a carefully prepared lecture was read and
discussed. The subjects of these lectures indicate to such an extent
the lines of interest developed in the department, that a list for 1890-
92 is given in full.
Biology. 103
1. Scope and Aims of the Club. — C. 0. Whitman.
2. Ideas on the Origin of the Galapagos Islands and the Origin of Species.
— Geo. Baur.
3. Insect Metamorphosis. — W. M. Wheeler.
4. The Origin and Significance of the Blastopore. — J. P. McMurrich.
5. Nitrification and Nitrifying Organisms. — E. 0. Jordan.
6. The Animal Ovum. — Sho Watase.
1. The Salisbury Expedition to the Galapagos Islands. — Geo. Baur.
2. The Third Eye of Vertebrates. — A. C. Eycleshymer.
3. Some Points in the History of Bacteriology. — E. 0. Jordan.
4. Amphimixia in the Protozoa. — H. P. Johnson.
5. Nervous System of Mollusca. — F. R. Lillie.
6. Germ Cells. — Sho Watase.
7. Mammalian Spermatogenesis. — Sho Watase.
8. Metamerism in Arthropods. — W. M. Wheeler.
The scope of work of the morphological section will be seen more
fully in the list of investigations which follows, under the heading of
Research Work, which has been grouped together for all divisions of the
biological department.
In Vertebrate Anatomy, Dr. Mall lectured for three successive years
on the histology of tissues arising from the mesoderm, on the develop-
ment of serous and blood spaces in vertebrates, and on the development,
histology, and comparative anatomy of the organs arising from the
endoderm. Dr. Tuckerman lectured in connection with his research
work, on the gustatory organs of mammals, and Dr. Miller likewise on
the lobule of the lung with its blood-vessels.
In Physiology Dr. Lombard devoted a series of lectures of a year
each, supplemented by numerous demonstrations, to the following sub-
jects : —
1. Physiology of Muscle and Nerve.
2. Physiology of Circulation and Respiration and the Nervous Mechanisms
by which they are regulated.
3. Physiology of Muscle, Nerve, and Spinal Cord.
Dr. Cardwell gave a number of lectures upon Animal Locomotion
and Coordination. And Drs. Hodge and Jordan lectured respectively
on the Physiology of Spinal and Peripheral Ganglia, and the Physiology
of Leucocytes.
104 Department of
A convenient laboratory was fitted up with microscopes, microtomes,
and all needed instruments, materials, and reagents for neurology. A
number of brain and other neurological specimens were prepared for
purposes of instruction and demonstration, and the best neurological
models were purchased with this end in view.
Dr. Donaldson lectured during 1889-90 on the anatomy of the central
nervous system in man ; and in 1890-91 completed the course by treat-
ing the peripheral nervous system and discussing at length the various
physical measures, so-called, of intelligence as found in the brain, its size,
weight, convolution, thickness of cortex, and relative development of
lobes, as these have been presented in the history of neurology. The
course was repeated in 1891-92, together with a practice course in the
laboratory on the histology of the nervous system.
A seminary which met once a week was devoted to the reading of
papers on neurological topics, both of historical and current interest, and
to reports on work in progress in the laboratory.
The primary aim of the department, as Professor Whitman expressed
it, is to make " research men," men imbued with the spirit and desire for
original investigation. This purpose is seen in all the courses of instruc-
tion and becomes even more patent in the number of investigations actually
in progress in the different laboratories of the department. In fact, the
serious work of every member was research, for which lecture and semi-
nary combined to form an appropriate historical and philosophical back-
ground.
During this period. Professor Whitman being in charge of Woods
Holl Marine Laboratory, practically all the men in morphology continued
their studies there through the summer seasons, taking microscopes,
apparatus, and reagents from the University. Lectures were also given at
Woods Holl by Professors Donaldson, Lombard, and McMurrich, and
Drs. Watase, Wheeler, and Jordan assisted Professor Whitman with
the laboratory instruction.
The following resume is given to present a general picture of the
spirit and scope of the department's work during this three-year period.
RESEARCH WORK.
Professor Whitman, in addition to editing the Journal of Morphology^
equipping and directing a new and complicated laboratory, and giving
Biology. 105
regular lectures, spent most of his time investigating the Hirudinea,
publishing a series of papers on their classification, with descriptions of
new species, on their metamerism, and on their hypodermic impregnation
by means of spermatophores. " Specialization and Organization," " The
Naturalist's Occupation," and other papers show that he was following lines
of more general interest both in scientific work and in public education.
Dr. Baur was delving in problems of fundamental importance in com-
parative osteology of vertebrates, morphology of the vertebrate skull,
carpus, ribs, etc., and working out the descriptions of a number of forms
discovered during his successful paleontological expeditions. A good
share of his work grouped itself about the plan of his great expedition to
the Galapagos Islands, which was finally made possible by the munificence
of the Hon. Stephen Salisbury, together with contributions from Pro-
fessor H. F. Osbourn and from the Elizabeth Thompson Science Fund.
This trip Dr. Baur made (in company with Mr. C. F. Adams) be-
tween May and October of 1890, visiting all the islands, excepting Nar-
borough, Wenman, and Culypepper. Extensive collections of both flora
and fauna were obtained, which were worked up by Dr. Baur himself and
by specialists both in this country and in Europe. The main general
result of the expedition was a demonstration of the fact that the life on
these islands is harmonious, and hence that the islands themselves must be
explained on the subsidence theory, rather than on that of emergence as
held by Darwin, Wallace, and others.
Dr. McMurrich devoted his time chiefly to investigating the morphol-
ogy and embryology of the Actinozoa, and from these researches derived
his conclusions as to the phylogeny of the group. Dr. Watase was at work
on various fundamental problems on the cell, caryokinesis, cleavage of the
ovum, spermatogenesis, and sex differentiation.
The research work of other members of the department was dis-
tributed as follows : Mr. Johnson investigated the morphology and
biology of the Stentor. Mr. Lillie studied the embryology of Unio. Dr.
Wheeler worked upon the embryology of the Insecta, and in that connec-
tion investigated the neuroblasts in the Arthropod embryo. Dr. Bumpus
completed his study, already under way, upon the embryology of the
American lobster. Dr. Edwards studied the embryology of the Holo-
thurians. Dr. Jordan studied the life history and embryology of the
common newt ; and Mr. Eycleshymer made a special investigation of the
development of the optic vesicle in the amphibian embryo.
106 Department of
In the closely allied field of vertebrate anatomy, Dr. Mall was making
a minute study of a human embryo, investigating the formation of the
lesser peritoneal cavity in birds and mammals, the motor nerves of
the portal vein, and also completed his important work on a new connec-
tive tissue element, the reticulated connective tissue, with its distribu-
tion in the body. Dr. Tuckerman carried on an extended research on
the gustatory organs of a series of animals, and their development in man.
Dr. Miller also worked out the minute anatomy of the lung, and by a most
exhaustive and varied method succeeded in demonstrating for the first time
the manner of ending of the terminal bronchi, together with their relations
to the arteries, veins, and capillary system. On the side of practical surgery
Dr. Homer Gage conducted a series of experiments on intestinal suture.
In physiology Dr. Lombard continued his investigations on effect
of fatigue on voluntary muscular contractions and alterations in strength
which occur in severe muscular work, and on the conditions, barometric
pressure, temperature, sleep, food, alcohol, and tobacco, which effect
voluntary effort. Dr. Cardwell investigated the physiology of the
cerebellum with relation to animal locomotion and coordination.
For neurology Dr. Donaldson was pursuing a similar plan with that
followed by Dr. Whitman in morphology, viz., gathering the history of
the science from original sources, and reducing to uniform statements,
tables, and curves all the data as to size and weight, both relative and
absolute, of the brain. In this connection he made an exhaustive
study, both gross and microscopical, of the brain of Laura Bridgman.
An extended series of observations was also being carried on in the
laboratory upon the influence of hardening reagents upon brain weight
and specific gravity. Dr. Hodge worked for two years (1889-91)
on the physiology of nerve cells, their diurnal fatigue and recovery in
sleep, and their recovery from effects of electrical stimulation. Dr.
Donaldson, with Dr. Bolton, completed a study of the size of the cranial
nerves in man, and Dr. Bolton studied microscopically the spinal cord
of a horse affected with spring halt.
The above gives, in the main, a picture of the work in progress
during the first three years of the department's existence. All but
one or two of the researches mentioned have been published, together
with others not cited. For place of publication and the complete record
the reader is referred to list of publications by members of the University
for the corresponding years.
Biology. 107
If one science is entitled to claim the special interest of the founder
more than another, biology is that science ; and in the organization of this
department, the aim above all else was to make it the most ideal pos-
sible place for biological research. Foundations were laid at this time
for a special building more adequately to house this flourishing depart-
ment. How well the ideal was realized may be seen from the estimate
of Professor Whitman, whose experience in the laboratories of three
continents entitles him to an opinion. Writing in 1899, he says, " The
Clark University Ideal, as I understood it when connected with its early
work, is the ideal which I place above any other thus far proposed, and
I hope it may find strong friends to help it forward." Unencumbered
by the burden of undergraduate courses, untrammelled by red tape and
traditions, the laboratory formed for three brief years a veritable garden
spot in the field of biological history in this country. It was a place
where each man was free to devote all his best energies to just that
which he wanted most to discover ; where the best thing a man could
possibly do for himself constituted the highest service he could render
to the University.
A "Flying Squadron," has been suggested as the most fitting defi-
nition for a university. Scarcely had this splendid organization been
attained than it was carried off bodily, almost, to lay foundations for the
biological department in a new university. While no higher tribute
could have been paid to Clark University, it has left the department
sadly crippled both for men and means for work.
Since 1892 biology has been represented by but a single instructor.
Dr. Hodge, who was recalled from the University of Wisconsin, with
the title of Assistant Professor of Physiology and Neurology. For the
first year Dr. Hodge offered only courses on the physiology, anatomy,
and embryology of the nervous system. During the succeeding years,
owing to the great need of having the subject pl-esented, a course in gen-
eral biology has been given, the aim of which is to present the funda-
mental principles of the science. A sense of the importance of this
course has grown from year to year, with the conviction that the sub-
ject finds too little representation in most of our educational institutions ;
and it is hoped, as soon as practicable, to develop it into a solid course,
historical, philosophical, and practical, to extend through all of two and
possibly three years of university study. The main courses offered by
Dr. Hodge have related to anatomy and physiology of the nervous sys-
108 Departme7it of
tern, both comparative and human, including the sense organs as well,
and to the entire field of physiology and to that of embryology, especially
of the nervous system and sense organs. These have been supplemented,
wherever possible, by laboratory courses. A seminary meeting, usually
one evening weekly, has been maintained, the plan of which has been,
in the main, to spend a year upon each of the three following top-
ics : 1, history of medicine, with special reference to physiology, epochs,
schools, and men ; 2, history of, and present discussion centring about, the
doctrine of evolution ; 3, development of neurology. A journal club,
meeting weekly, has aided to bring all members of the department
together for discussion of articles in current literature. In general, all
seminaries and courses of instruction have been given with reference to
furnishing aid and stimulus to students in their research work.
In addition to the above, on the teaching side. Dr. Hodge has
become interested in lines, especially of biological education in ele-
mentary schools. A definite standpoint for elementary nature study has
been developed, which is a distinct reaction against the tendency toward
technicality, classification, and minutiae which have come to constitute so
large a part of our elementary science courses. It is planned to include
this in the general biology course by way of discussing the question.
What aspects of biological science shall be taught in the elementary
school ? The kind of physiology which should form a part of elementary
education has also been given considerable attention. Both subjects have
formed the basis for courses in the summer school.
In passing to consider the research work of the department since Dr.
Hodge took charge of it, a word as to its general purpose and plan will
simplify the discussion.
Science, in this country especially, has become unnecessarily arrogant.
We hear on all sides such expressions as " pure science," a term which
Huxley wished had never been invented, " truth for truth's sake " or
" science for the sake of science," and the " uselessness " of science is
made a boast. An important truth is stated in these expressions ; for
science is of such paramount use and importance to mankind that to
discuss this point with one who says it is not, is clearly " casting pearls
before swine." Possibly another reason for resorting to these expres-
sions is that the human values attaching to knowledge are so enor-
mous that we have no measures or terms with which to adequately
express them. However this may be, if science have a faith worthy
Biology. 109
of respect, it should result in mutual benefit to share it so far as pos-
sible with a reasonable and intelligent public.
A research laboratory is an institution the business of which is to
investigate those problems which have either never been attempted or
have hitherto baffled all efforts of the human mind to solve. These
problems are not far to seek, but crowd upon our lives at every point.
The values attaching to their solutions can be expressed only in terms of
human life and happiness, compared with which the output of Klondikes
and Cripple Creeks is but the small change of the hour. It is clearly
recognized that we may not be able to estimate the value of truth until it
be discovered, and that the investigator himself, who is willing to devote
his time and energies to the work, should be the one to estimate its values,
and that he should have the greatest freedom to select the task for which
he knows himself to be best fitted. Still, one must be a man before he
can be a scientist, and fundamental human values must be in the main
the same for all. And it would seem to be the first duty of a research
laboratory to devote its resources to the work of solving those problems
which concern human life most closely, and possess the greatest human
importance. A laboratory owes no less than this to a community ; or,
better stated, a laboratory is that part or organ of a community differ-
entiated to perform the special function of discovering and making avail-
able whatever truth is of greatest value to its common life.
In deciding the directions, therefore, which research work shall take,
the above general policy has been followed, and it is a satisfaction to note
that the same sentiment was prominently expressed at the founding of
the University. On that occasion Mr. Hoar spoke as follows : —
" Speaking now for myself alone, I have little sympathy with that arrogant
and disdainful spirit with which some men who undertake, with little title, to
represent science in this country, sneer at any attempt to make use of the
forces she reveals to us for the service of mankind. Some one said the other
day that science was becoming a 'hod-carrier.' I do not see why the term
' hod-carrier ' should express the relation rather than the term ' benefactress.'
I do not see, either, that there is anything degrading in the thought that
the knowledge of the learned man enables him to lift the burden beneath which
humanity is bowed and bent. I do not know that science is exempt from the
divine law, ' He that is greatest among you, let him be the servant of all.' If
the great forces of the universe perform all useful offices for man, if the sun-
shine warm and light our dwellings, if gravitation move the world and keep it
true to its hour, nay, if it keep the temple or cathedral in its place when the
110 Department of
hod-carrier has builded it, I do not see why it should not lend its beneficent aid
to him also. Our illustrious philosopher advised his countryman to " hitch his
wagon to a star." The star will move no less serenely on its sublime pathway
when the wagon is hitched to it. I do not know that any archangel or god-
dess, however resplendent the wings, has ever yet been constructed or imag-
ined without feet. I do not know that any archangel, however glorious, has
ever been created or imagined without sympathy for suffering humanity.
" I look for great advantage to the country, both in wealth and power and
in the comfort and moral improvement of the people, by the application of
science to the useful arts."
The maimer in which this fundamental purpose has been carried out
thus far may now be seen in part in the lines of work which have been
carried out, and, more fully, in plans for the future.
In this country of, so-called, nervous tension, nervousness and nervous
prostration, nothing could be of greater value to the common life than
knowledge of the fundamental laws of the working of nerve protoplasm.
It is only in discovery and obedience to these laws that we may hope for
escape from present evils and possession of sane and permanent national
health. Consequently lines of investigation upon the physiology of
the nerve cell have been kept open from the beginning. Continuing the
studies mentioned in speaking of an earlier period in the history of the
laboratory, the nerve cell has been studied during its electrical stimulation
.and also in connection with changes which occur in the process of aging
and in death from old age. Dr. Barrows has investigated its appearance
nnder various kinds of diet and when the body has been deprived of food,
Dr. Stewart has studied the effect of alcohol on the cells of the cerebrum,
cerebellum, and spinal cord. Drs. Starbuck and Lancaster respectively
studied effects on the nerve cell of artificial (by means of electrical stimu-
lation) and natural fatigue carried to an extreme degree. Dr. Kenyon
devoted a year to a most successful study of the brain of the honey-bee.
Dr. Burk devoted considerable time in working out the meduUation of
the brain in puppies. Dr. Goddard tested by especially rapid methods
of preparation theories as to the possible amoeboid movements of nerve
cells in conditions of activity and sleep. Further experiments are now in
progress on the influence of alcohol, and work has been begun on the
effect of other chemical substances, notably strychnine, morphine, and
nicotine on nerve cells. For the purpose of making possible a more prac-
tical study of the human brain, a brain microtome has been devised in the
laboratory by Dr. Goddard, with suggestions from Dr. Hodge. This
Biology. Ill
instrument is constructed on principles new to such microtomes thus far
made, and has rendered it possible to cut sections of the entire human
brain in any desired plane with the ease and uniformity with which smaller
sections are cut by the ordinary microtomes. The blade of this microtome
was made, and presented to the University, by the firm of Loring, Goes, &
Co. of Worcester.
A research less closely connected with the general plan, but still es-
sentially upon the nervous system, was carried out by Dr. Slonaker upon
the eyes of vertebrates.
This line of work in the physiology of the nervous system is one
which the department proposes to continue, as opportunities and properly
prepared men present themselves, until, it is hoped, the American public
may be able to live on more amicable terms with its "nerves."
In order to attack, in a more fundamental manner, problems centring
about the nerve cell and its normal activities, it has been necessary to
make a wide detour of investigation in two directions. The first of these
has consisted in a study of the microscopical appearances of lymph as
compared with different special protoplasms under various methods of
hardening and staining. This has proved to be a matter of fundamental
importance to histology in general, and has demonstrated that, until we
are able to gain some definite notion as to the substances in question, it is
useless to go on figuring and describing " granulations," and " fibrillse,"
" alveoli," and the like.
The other line of research to which study of the rhythms of the nerve
cell has led logically is that of the physiological conditions in general
which underlie and determine phases of animal activity. In other words,
if we wish to learn the condition of nerve cells in states of rest and fa-
tigue, we must study first the normal rhythms of activity and rest of our
animal. Knowing this, we may be able to examine the nerve tissues at
any desired point in the curve of functional activity. And in order to
gain the fundamental laws of nervous activity, we need to study these
rhythms of sleep and waking, rest and activity, which make up the normal
flow of an animal's life, in a series of animals. This fundamental work
has not been done for more than one or two forms as yet, and for those
only in a preliminary way. Dr. Aikin's study of vorticella, which
showed that a one-celled animal is capable of continuous activity so long
as food and environment remain suitable, was the first on the subject.
Stewart's experiments on the influence of barometric pressure and diet,
112 Department of
including alcohol, on the diurnal activity of rats and mice, together with
Dr. Hodge's similar work on dogs and squirrels, serve further to indicate
the possibilities in this field. These studies have pointed to the fact that
the activity of each animal conforms to a type as to periods and rhythms
which is characteristic of the species, and that the total amount of work
developed is profoundly influenced by physiological conditions thus far
investigated. These researches have been suspended for the present,
but it is hoped to push the work in the near future along two main
lines. The first of these aims to discover the typical rhythms of physio-
logical activity for a series of animals, both invertebrate and verte-
brate. It would seem that these physiological types are of even greater
ultimate interest and philosophical importance than the purely structural
and morphological types from which the comparative anatomists have
worked out the evolutionary series. When this has been done, we shall
be in position for the first time in the history of biological science to
study human rhythms of activity and repose in the light of similar rhythms
of the animal series, and to gain, possibly, some notion as to a norm for
human work. The second line of study in this field essays to analyze the
physiological conditions under which any particular animal is able to
develop the greatest possible amount of normal activity. This is no less
a problem at bottom than the study of the physiological conditions which
underlie the highest possible types of human life and activity.
The question naturally arises at this point as to what position the
biological department of Clark University assumes upon some of the
wider aspects of the science.
Since the times when Aristotle employed the armies of Alexander the
Great to collect specimens for his museums from all the then known
world, the greater portion of biological effort has been directed toward
classification and naming of animal and plant species. The uttermost
corners of the earth have been searched to the tops of the mountains and
dredged to the deepest ocean depths, all to discover some new species of
animal or plant, while the common plants and animals of our dooryards
are known scarcely more than in name. This classification work, ex-
tending from Aristotle in Greece through Linne and Cuvier, Buffon
and Brehm, to Agassiz in America, has been in part necessary and impor-
tant. But, when it is possible to find single species which have been
christened ten or even twenty times, it is safe to insist that the passion
for naming things has been carried too far. This passion for names is
Biology. 113
characteristic of a certain period in infancy in the individual, and, we
may hope, in the growth of a science as well ; and while it gives the best
promise for the future, is it not time to hope that this phase of biology
may wane, and the maturer work of learning the really important facts
concerning animals and plants be seriously undertaken ? These facts of
paramount importance have to do with the functions of species, the work
species do in the world. As a matter of fact, to work in classification by
methods of external characters the monumental work of Darwin and
Wallace has long since put a final period. Species are not fixed immu-
tably, but are plastic and normally variable. Embryological studies,
even by Louis Agassiz himself, proved that animals repeat simpler stages
of organization each in its own life history. With the doctrine of evolu-
tion the whole method of the science has been changed. Deeper char-
acters than those on the surface must be discovered, and only such as
reveal blood relationships and indicate the true position of the species in
the line of evolutionary descent can be of permanent importance in the
new classification. Thus the past two decades have been devoted in
biological laboratories largely to tracing most minutely the embryology
of different species, and in exhaustive studies into comparative anatomy
and embryology combined. There has been a constant gravitation, natu-
rally enough, to again consider the findings of the microscope, arrange-
ments of cells, and all the infinite variety of granule and rod and fibril as
fixed entities, rather than again as plastic and possibly changing with
every phase of functional activity. There has thus been no limit to the
careful drawing and figuring and coloring of what are supposed to be
important structures in living protoplasm. This may all be well enough
as pastime. But where the idea of functional changes has been left out
of account, the work is builded on the sand. It is like studying and map-
ping the positions, forms, and colors of the clouds by means of the nice
adjustments of the telescope. Many of the books of the past decade will
be museum junk before 1910, if they are not already. We need to real-
ize in our modern laboratories that turning the crank of a microtome in
and of itself has no more educational value, possibly not so much, as
turning the crank of a grindstone. In fact, our theories of laboratory
research and even of laboratory instruction in the brief period in which
these have come into prominence have gone far astray. In drifting
away from all considerations of human good and even common sense,
our modern laboratory work is in the same danger of becoming an end in
114 Departinent of
itself that sunk the old classification into a worse than imbecile waste of
time.
Furthermore, progress is the word which has characterized every
expression of the purpose of the biological department. The advance-
ment of science has been its fundamental raison d'etre from the beginning.
There is little danger that the world will have too many institutions de-
voted to the serious work of advancing science. The great difficulty has
been, and, we may add, still is, that, after a period of great achievement,
the inevitable tendency asserts itself to spin round and round about it as
though there were nothing else ahead worth working for. The endless
discussions of the past two decades reminds one of the hollow disputations
of the scholastics. The coursing over and over again of the ground
covered so well by Darwin and Wallace, and even by Aristotle, in great
part, has been enough to raise the shades of some of these good men to
urge us to cease hairsplitting and trifling, and go forward into the great
field which their works have opened up.
Their great contributions have consisted in demonstrating the plas-
ticity of living forms, and the field which this presents is that of infinite
possibilities of perfection and utilization in the future. It has opened up
before us, instead of the dead finality, the idiotic circle with its endless
round of " vanity of vanities," of the old philosophy, an infinite future
of progress. In this progress Science must worthily lead, but may well
hold Art by the hand, lest the doing of science, which is its consummation
in virtue, fall behind, and Science, herself, languish for very lack of
sustenance.
"We expect great help for the present status of biological science from
Brooks's " Foundations of Zoology." To the question which he imagines
Aristotle to ask : " Is not the biological laboratory which leaves out the
ocean and the mountains and meadows a monstrous absurdity ? " this
department would answer — Yes. And it would add that it is not enough
to bring our laboratories to the ocean and make fine trips to the mountains
and the ends of the earth, unless these great factors become a real part of
the scientific quest.
In a word, with the so-called discovery and naming of a species of
animal or plant, and even with its embryonic and adult anatomization,
biological science has scarcely touched the great problem which the
species presents. With the half million species of animals and plants of
which Science has told us scarcely more than the names. Art has stumbled
Biology. 115
haltingly along, with all too little help from Science, toward the perfection
and utilization of a very few, our domesticated species. Even with these
few the scientific biology of no single one has been adequately worked out,
and we are practically in the beginnings of scientific studies as to the
influence of environment in cultural conditions, and as to the possibilities
for improvement in cross fertilization. Biological science owes to the
world not only knowledge of the name, form, and structure of a species ;
it owes as well a clear statement of what the species does, considered as a
force in nature ; and further, the method by which this force can best be
utilized. And this is no whit less pure science because incalculable
human values attach to the knowledge. Biologically we are now at a
stage comparable from the standpoint of physical science with that of the
sail-boat and the stage-coach, before science had discovered, and discov-
ered a way to utilize, the forces of steam and electricity. And we find,
when we study carefully what one animal or a plant can c?o, and multiply
this by the number of individuals in the species, values and magnitudes,
which we scarcely possess terms to express. Add to the total amounts
of forces which different species represent, the nicety of adjustment,
the adaptation of means to ends, the intelligent direction of the forces,
which make comparative psychology a part of biology, and we begin to
realize the importance of biology as a science. No seed is too small to
contain the power, under proper conditions, of covering the world with
plants of its kind ; and, not only that, but generation after generation it
may be capable of indefinite improvement. The most minute organisms,
the bacteria, possess very few interesting features of form or structure
that we are able to discover, but they have the power to determine the
ultimate food supply of all animal life, on the one hand ; and, on the other,
to cause the disease, suffering, and death of untold numbers of animals,
and even human beings. Insects, on the one hand, have created flowers
and fruits by their work of cross fertilization, and, on the other, have laid
a tax on human industries heavier than that of bad government and even
of war.
Since the side of function, of the actual work which a species can do,
presents the greatest ultimate value connected with knowledge of living
things, if modern biology does not go forward into this great field, its
whole past history from Aristotle down will be an arrested development.
The laboratory that undertakes this work must be a unique affair as
biological laboratories go now. It should have greenhouses, terraria and
116 Department of
aquaria, aviaries and insectories, in order to provide the essential elements
of normal environment where the life and work of species may be conven-
iently studied in both their daily rhythms and in their larger life cycles.
It should especially have easily accessible the actual normal environment
of the species under investigation, the pond, ocean, stream, grove, forest,
hill, mountain, field, and garden, where results obtained in the laboratory
can be readily tested and confirmed in the actual environment of nature.
In fact, during favorable seasons much of this line of laboratory work
might well be done out of doors. A laboratory of this kind need not be
expensive, but should consist largely of rooms adapted for individual
investigators, so that researches upon the life and work of a number of
different forms may be carried on with the least possible mutual disturb-
ance and interference. This is an absolute essential to investigations
of this class. It should also be provided with sunny and sanitarily
perfect quarters for not only keeping, but rearing and breeding, a con-
siderable variety of animals.
These and many other considerations render it imperative, if work
of the best quality is to be turned out, that a biological laboratory have
a building of its own. At present this lack has been one of the chief
obstacles to prosecution of the important lines of work indicated. They
cannot be successfully studied in rooms used for other purposes, or in a
building shaken by the running of powerful dynamos and other heavy
machinery. Natural rhythms and periods of rest and activity may be
profoundly influenced by these disturbing conditions, and results thus
largely vitiated. As already stated, the foundations for a biological
laboratory have been laid, and an inexpensive building would greatly
facilitate the work of the department. It ought to be erected under
the idea, now gaining ground, that a laboratory should be a somewhat
temporary building, which could be altered and reconstructed from time
to time as new problems arise.
The matter of biological nature study has already been referred to,
and it is the opinion that such a research laboratory should be in
organic relationship with elementary education and the public school.
It is believed that this side of nature, the side of movement and activity,
is the natural side of approach for the child. It is peculiarly akin to
that animism of childhood which projects life and action even into
inanimate things. It is this side of living nature, which, from its
intrinsic fascinations and varied affinities with the passionate activity
Biology. 117
of child life, is calculated to create enduring love of nature ; and the
vast human values and interests connected with it constitute the most
natural wellspring for love of science.
In line with this idea, two nature-study leaflets have already been
printed, upon, respectively, the " Biology of the Common Toad " and the
"Biology of Our Common Birds." Both of these were written by Dr.
Hodge, and he has thus far assumed all financial responsibility for their
publication. He also has in course of preparation similar studies on a
series of biological subjects, insects, fishes, and reptiles, flowers, fruit,
and forest trees, bacteria and moulds, and a few others, which will
provide ample materials for nature study from the standpoint above
indicated for the entire school course. On the one hand, such connection
between the biological laboratory and the schools will furnish channels
for the distribution of information to the public, and, on the other, may
be made to supply, not only stimulus, but assistance to its work as well.
Bacteriology is a recently created department of biology which has
claimed recognition as an independent science by reason of its wonder-
ful development since about 1880, when the discoveries of Koch, Pasteur,
and Lister revealed the causal relations which exist between these
minute organisms and disease. We can express the enormous values
of scientific knowledge of these germs only in terms of human life itself.
And it is a worthy refutation of the charge sometimes brought against
science that it disregards the welfare of humanity that, as Professor
Ludwig said, laboratories devoted to other lines of biological work
have been depopulated, because their students have flocked into this
new and important field. The bacteria are coming to be recognized as
one of the most, if not the most, important element in the environment
of animal and even plant species ; hence their consideration is essential
in such studies as have been outlined above, which aim to determine
the influence of environmental conditions upon the activity, health, and
vigor of species. Still the pathological side will not be able long to
dominate the science of biology ; and even with relation to diseased
conditions, the side of normal function, physiology proper, must remain
preeminent. In fact, it may even now be stated as the highest contri-
bution of bacteriology, that it has revealed the fact that the highest
possible health level is the best practical safeguard against inroads of
microbic disease. Still the great importance of the subject has made it
cause for regret that the resources of the department have not permitted
118 Deimrtment of Biology.
the establishment of a well-equipped bacteriological laboratory. The
next step in the development of the department should be in this
direction.
The library of the biological department has been selected with a
view to making it the best possible working library for those engaged in
biological research.
THE DEPARTMENT OF PSYCHOLOGY.
By Edmund Clark Sanford.
PAST AND PRESENT STAFF, i
G. Stanley Hall, Ph.D., LL.D., President of the University and Professor
of Psychology and Education since 1889.
Henry H. Donaldson, Ph.D., Assistant Professor of Neurology, 1889-92.
Clifton F. Hodge, Ph.D., Assistant in Psychology, 1890-91 ; Assistant Pro-
fessor of Physiology and Neurology since 1892.
Edmund C. Sanford, Ph.D., Instructor in Psychology, 1889-92; Assistant
Professor of Psychology since 1892.
William H. Buknham, Ph.D., Docent in Pedagogy, 1890-92 ; Instructor in
Pedagogy since 1892.
Benjamin Ives Gilman, Instructor in Psychology, 1892-93.
Alexander F. Chamberlain, Ph.D., Lecturer in Anthropology since 1892.
Franz Boas, Ph.D., Docent in Anthropology, 1889-92.
B. C. Burt, A.M., Docent in Philosophy, 1889-90.
Alfred Cook, Ph.D., Docent in Philosophy, 1889-90.
Herman T. Lukens, Ph.D., Docent in Pedagogy since 1895.
Arthur MacDonald, A.M., Docent in Ethics, 1889-91.
Adolf Meyer, M.D., Docent in Psychiatry since 1896.
Charles A. Strong, Docent in Philosophy, 1890-91.
FELLOWS AND SCHOLARS.
H. Austin Aikins, Ph.D., Fellow in Psychology, 1892-93 ; Honorary Fellow,
1893-94.
Ernest Albee, Scholar in Psychology, 1889-90 ; Fellow, 1890-91.
Arthur Allin, Ph.D., Honorary Fellow in Philosophy, 1895-96.
N. P. Avery, Scholar in Psychology, 1895-96.
Thomas P. Bailey, Jr., Ph.D., Fellow in Psychology, 1892-93.
1 As this list shows, the Department of Psychology has included, Anthropology, Crimin-
ology, Neurology, Psychiatry, Education, and Philosophy. The report of work in Neurology
has been incorporated by Dr. Hodge with that in Physiology and Biology.
119
120 Department of
Henry K. Baker, Student in Psychology, 1894-95 ; Fellow, 1895-96 ; Honor-
ary Fellow, 1896-97, and 1898-99.
John A. Bergstrom, Fellow in Psychology, 1891-94.
Eugene W. Bohannon, Scholar in Pedagogy, 1895-96 ; Fellow in Psychology,
1896-98.
Frederick E. Bolton, Honorary Fellow in Psychology, 1897-98.
Thaddeus L. Bolton, Scholar in Psychology, 1890-91 ; Fellow, 1891-93.
Ernest N. Brown, Scholar in Psychology, 1891-92.
Elmer B. Bryan, Scholar in Philosophy, 1898-99.
William L. Bryan, Fellow in Psychology, 1891-93.
Frederic Burk, Scholar in Psychology, 1896-97 ; Honorary Fellow, 1897-98.
Will G. Chambers, Scholar in Psychology, 1897-98.
Walter Channing, Honorary Scholar in Psychology, 1889-90 ; Honorary
Fellow, 1890-92.
Oscar Chrisman, Fellow in Pedagogy, 1892-94.
Robert Clark, Scholar in Pedagogy, Jan., 1898-June, 1899.
Charles W. Clinton, Fellow in Psychology, 1897-98.
Frederick W. Colegrove, Honorary Fellow in Psychology, 1896-99.
Thomas R. Croswell, Scholar in Pedagogy, 1895-97.
Henry S. Curtis, Fellow in Psychology, 1895-97.
Arthur H. Daniels, Fellow in Psychology, 1892-93.
George E. Dawson, Fellow in Psychology, 1895-97.
Fletcher B. Dresslar, Scholar in Psychology, 1891-93 ; Fellow, 1893-94.
Frank Drew, Scholar in Psychology, 1892-93; Fellow, 1893-95.
Frederick Eby, Scholar in Pedagogy, 1898-99.
Stafford C. Edwards, Scholar in Pedagogy, 1897-98.
A. Caswell Ellis, Scholar in Pedagogy, 1894-95 ; Fellow in Psychology,
1895-97.
H. L. Everett, Scholar in Psychology, 1896-97 ; Honorary Fellow, 1897-98.
Daniel Folkmar, Fellow in Psychology, 1889-90.
Clemens J. France, Scholar in Psychology, 1898-99.
J. Irwin France, Scholar in Psychology, 1896-97.
Alexander Eraser, Fellow in Psychology, 1891-92.
John P. Fruit, Scholar in Psychology, 1891-92.
Henry H. Goddard, Scholar in Psychology, 1896-97 ; Fellow, 1897-99.
Cephas Guillet, Scholar in Psychology, 1895-96 ; Fellow, 1896-98.
John A. Hancock, Fellow in Pedagogy, 1893-94.
S. B. Haslett, Scholar in Psychology, 1898-99.
Clark W. Hetherington, Fellow in Psychology, 1898-99.
tR. C. Hollenbaugh, Ph.D., Scholar in Psychology, 1892-93. Died July 6, 1893.
William A. Hoyt, Scholar in Pedagogy, 1893-94.
Edmund B. Huey, Scholar in Psychology, 1897-98; Fellow, 1898-99.
D. D. Hugh, Fellow in Psychology, 1895-96.
John P. Hylan, Fellow in Psychology, 1895-97.
Psychology. 121
TiLMON Jenkins, Scholar in Pedagogy, 1897-98.
George E. Johnson, Scholar in Pedagogy, 1893-94 ; Fellow, 1894-95.
E. A. KiRKPATKicK, Scholar in Psychology, 1889-90 ; Fellow, 1890-91.
Milton S. Kistler, Scholar in Pedagogy, 1897-98.
Linus W. Kline, Scholar in Psychology, 1896-97 ; Fellow, 1897-98 ; Honorary
Fellow, 1898-99.
William O. Krohn, Ph.D., Fellow in Psychology, March-June, 1892.
E. G. Lancaster, Scholar in Psychology, 1895-96 ; Fellow, 1896-97.
James S. Lemon, Scholar in Psychology, 1891-93 ; Student, 1893-94.
James E. Le Rossignol, Ph.D., Fellow in Psychology, May-July, 1892.
James H. Leuba, Scholar in Psychology, 1892-93 ; Fellow, 1893-95 ; Honorary
Fellow, 1895-96.
Ernest H. Lindley, Fellow in Psychology, 1895-97.
George W. A. Luckey, Fellow in Psychology, 1894-95.
Frank H. McAssey, Scholar in Psychology, 1898-99.
George F. Metzler, Ph.D., Fellow in Psychology, 1891-92,
Dickinson S. Miller, Fellow in Psychology, 1889-90.
Herbert Nichols, Fellow in Psychology, 1889-91.
C. A. Orr, Scholar in Psychology, 1889-90.
George E. Partridge, Special Student in Philosophy, 1895-96; Scholar in
Psychology, 1896-98 ; Fellow, 1898-99.
T. Richard Peede, Special Student in Philosophy and Pedagogy, 1895-96 ;
Honorary Scholar in Philosophy, 1896-97.
Daniel E. Phillips, Scholar in Psychology, 1894-March, 95 ; Honorary Scholar,
Jan.-June, 97 ; Fellow, 1897-98.
Jefferson R. Potter, Scholar in Pedagogy, 1890-91.
J. 0. QuANTz, Ph.D., Honorary Fellow in Psychology, 1897-98.
J. F. RiEGART, Scholar in Psychology, 1890-91.
Robert J. Richardson, Fellow in Psychology, 1898-99.
Erwin W. Runkle, Ph.D., Honorary Fellow in Psychology, Jan.-June, 1899.
Albert Schinz, Ph.D., Honorary Fellow in Psychology, 1897-98.
Alva R. Scott, Honorary Scholar in Psychology, 1894-95 ; 1896-97.
Colin A. Scott, Fellow in Psychology, 1894-96.
E. W. Scripture, Ph.D., Fellow in Psychology, Jan.-June, 1891 ; 1891-92.
Charles H. Sears, Ph.D., Honorary Fellow in Pedagogy, 1897-99.
Albert E. Segsworth, Honorary Fellow in Psychology, 1893-94.
John C. Shaw, Scholar in Pedagogy, 1895-96 ; Fellow in Psychology, 1896-97.
Henry D. Sheldon, Fellow in Pedagogy, 1897-99.
Frederic D. Sherman, Ph.D., Honorary Fellow in Psychology, 1898-99.
TosHiHiDE Shinoda, Honorary Scholar in Pedagogy, 1889-90.
Maurice H. Small, Scholar in Psychology and Pedagogy, 1895-96 ; Fellow in
Psychology, 1896-98.
WiLLARD S. Small, Scholar in Psychology, 1897-98 ; Fellow, 1898-99.
Frank E. Spaulding, Ph.D., Honorary Fellow in Psychology, 1894-95.
122 Departme7it of
Edwin D. Starbuck, Fellow in Psychology, 1895-97.
J. Richard Street, Scholar in Pedagogy, 1895-96; Fellow in Psychology,
1896-98.
Charles H. Thurber, Honorary Fellow in Pedagogy, Jan.-April, 1899.
Frederick Tracy, Fellow in Psychology, 1892-93.
NoRMAx Triplett, Fcllow in Psychology, 1898-99.
Gerald M. West, Ph.D., Fellow in Anthropology, 1890-91 ; Assistant, 1891-92.
Guy M. Whipple, Scholar in Psychology, 1897-98.
MiNosuKE Yamaguchi, Scholar in Psychology, 1897-98.
Albert H. Yoder, Scholar in Pedagogy, 1893-94.
Lewis E. York, Scholar in Pedagogy, 1897-98.
HISTORICAL SKETCH OF THE WORK IN GENERAL PSYCHOLOGY.
The ten years covered by the history of the Psychological Depart-
ment in this University have been eventful in the history of Psycho-
logical Science in the country at large.
Before 1880 the science was taught as a stepping-stone to metaphysics
and ethics ; its method was chiefly introspective ; laboratories were
unheard of; and genetic and comparative psychology were a terra
incognita. During the early part of the eighties, however, the idea
that psychology was an independent science, to be advanced by experi-
ment and systematic observation, was gradually taking root, and in
1888 and 1889 began a vigorous growth. New interest was taken
in the subject, laboratories began to be opened, and a special journal
was started for the publication of psychological investigations (^The
American Journal of Psychology'). Since that time the interest has
continued ; the laboratories have increased at the rate of three or
four a year till they now number between thirty and forty, are found
in almost all the leading universities of the country, are often liberally
supported, and in some cases surpass the best European laboratories
in equipment ; and many workers trained at home and abroad have
entered the field. In 1892 the American Psychological Association
was started, and now numbers over one hundred members, nearly all
actively interested in psychological teaching or investigation. A little
later genetic and comparative psychology appeared in an awakened interest
in the study of childhood; and more recently still have been extended
PsycJiology. 123
into a new and fruitful study of the mind and habits of animals.
Since 189-4 a second psychological journal, The Psychological Review^
has been published; and many articles of psychological interest appear
in the Pedagogical Seminary (especially on Child Study) and in the
other educational magazines. It is with such a period of vigorous
interest in psychology and of rapid growth in facilities that our own
ten years' history coincides.
In turning now to this more particularly, I shall speak first of
the work in experimental psychology, which, though by no means
the whole of the new movement, has been so far rather its centre and
characteristic mark, and afterward of that of a more general character.
The distinctive feature of American laboratories generally is the
extent to which they are used for psychological teaching as distinct
from psychological investigation. Both foreign and home laboratories
have the double purpose of instruction and research, but in the American
laboratories a little greater emphasis seems to be laid on their pedagogical
usefulness. This emphasis is doubtless due in part to more deep-
seated differences between American and foreign universities, but it
has been favored also by the feeling that a general acquaintance with
laboratory problems and methods should precede the undertaking of
original investigation. In the case of the Clark laboratory, it has
been further enforced by the number of students of pedagogy for whom
a psychological groundwork must be provided.
The advantage of laboratory teaching of psychology is that of all
proper laboratory teaching, namely, that the student is brought face
to face with that about which he is studying, and knows the thing
itself at first hand rather than what some text-book or lecturer may
say about it. For those who intend to take up experimental investi-
gation later, it is of course the natural apprenticeship.
Such elementary laboratory teaching demands some sort of manual
or guide that can be put into the hands of the students, a fact that
became painfully evident in the first years of the department ; and as
at the time none whatever existed, it was necessary to make one. A
beginning was made with manuscript sheets struck off on the mimeo-
graph. Later these were worked over in part in a series of articles in the
Journal of Psychology^ and, finally, again revised and enlarged, this part
was regularly published, six chapters in 1894, and the remainder last year,
making altogether a volume of about 450 pages covering the topics of
124 Department of
sensation and perception. This work seems to have supplied a genuine
need — at least, has met with a wide acceptance in American laboratories.
Up to the year just passed the laboratory course has not extended
beyond the usual laboratory topics of sensation and perception, reaction-
times, Weber's law, and the like. But, beginning with the year 1898-99,
an important enlargement was made by the addition of laboratory
practice in comparative psychology. Under the special guidance of
Dr. Kline, opportunities have been given for the study of the habits
and mental life of a number of more or less typical animals. Starting
with the microscopical amceba, paramecium, and vorticella, the list has
been extended upward to include earthworms, slugs, fish, chickens,
white rats, and kittens. Though lectures have been regularly delivered,
demonstrations made, and seminaries held in connection with the labora-
tory work, the development of this practice course in both experimental
and comparative psychology, together with the manual mentioned and
the similar though briefer work of Dr. Kline, is regarded as the most
important product of the Clark laboratory on its teaching side.
The scientific work of the laboratory has resulted in ten or twelve
extended researches and in a considerable number of briefer studies. It
is not easy in short space to give an intelligible account of studies upon a
variety of topics so considerable as these have covered, but it has seemed
to the writer that a list of the titles of papers published, with a few
lines of explanation where necessary, might serve the purpose.
STUDIES FROM THE PSYCHOLOGICAL LABORATORY.
Time and Rhythm.
Nichols : The Psychology of Time. Am. Jour, of Psy.., Vol. 3, pp.
453-529, and Vol. 4, pp. 60-112 (1891). (Dissertation.) Repub-
lished in book form by Henry Holt, New York, 1891.
A general discussion of the time problem. The experimental portion
shows that a period of practice in keeping time at a slow rate tends to
slow a quicker rate tried immediately afterward, and vice versa, thus
demonstrating a dependence of time j udgments upon artificially acquired
rhythms.
Bolton, T. L. : On the Discrimination of Groups of Rapid Clicks.
lUd., Vol. 5, pp. 294-310 (1893).
An indirect determination of the fineness of discrimination for very
short periods of filled time.
Psychology. 125
Bolton, T. L. : Rhythm. Ibid., Vol. 6, pp. 145-238 (1894). (Dis-
sertation.)
A general account of the subject. The experimental portion deals
with the subjective rhythms observed in uniform series of sounds, and
with the structure of the rhythmic feet which result when sounds of
different length or intensity are regularly introduced in an otherwise
uniform series.
Hamlin, Alice J. : On the Least Observable Interval between Stimuli
addressed to Disparate Senses and to Different Organs of the Same
Sense. Ibid., Vol. 6, pp. 564-575 (1895).
Experimental determination of the interval that must separate nearly
simultaneous sensations in order that their order may be recognized.
Experiments with clicks and flashes, flashes and shocks, separate clicks
heard by the two ears, etc., and with indifferent and with specially
directed attention.
Whipple: On Nearly Simultaneous Clicks and Flashes. Ibid. ,Yo\.
10, pp. 280-286 (1899).
A study of the reason for the difference between the results of
Dr. Hamlin and of earlier European observers in the matter of which
order of stimuli (click-flash or flash-click) could be more readily recog-
nized. Dr. Hamlin's results are confirmed and the difference proved not
to lie in the fact that the European observers had made use of series of
pairs of clicks, which had been supposed a possible cause.
Memory.
Bolton, T. L. : The Growth of Memory in School Children. Ibid.,
Vol. 4, pp. 362-380 (1892).
A study by the memory-span method on upwards of fifteen hundred
children, made in connection with the anthropometric studies of Dr.
Boas, together with a theoretical treatment of the statistical curves
obtained.
Bergstrom : Experiments upon Physiological Memory by Means of
the Interference of Associations. Ibid., Vol. 5, pp. 356-369
(1893).
The Relation of the Interference to the Practice Effect of an
Association. Ibid., Vol. 6, pp. 433-442 (1894).
An Experimental Study of Some of the Conditions of Mental
126 Dejxirtment of
Activity. lUd., Vol. 6, pp. 247-274 (1894). (These three papers
were united to form a Dissertation.)
A pack of eighty cards (eight cards each of ten different kinds) is sorted
according to the kinds, and after an interval re-sorted, but with such an
arrangement that each kind occupies a different place on the table. The
second sorting takes longer because of interference between the new as-
sociations and those formed in the first sorting, and the excess of time
required measures indirectly the persistence of the first set of associa-
tions. The first paper gives curves showing the rate of falling away of
the first associations (curves of forgetting) determined by this method.
The second paper, by an ingenious application of the same method,
shows that the interference power of any association is practically equal
to the fixity given it by practice, — in other words, " that the work of
breaking up a habit is roughly proportional to the work of forming it."
The third paper gives determinations of the variations in mental abil-
ity during the work hours of the day made upon several different sub-
jects and with different sorts of tests.
Daniels : The Memory After-image and Attention. Ibid., Vol. 6,
pp. 558-564 (1895).
The aim was to measure the native persistence of bare impressions
as distinguished from that which they show when received with atten-
tion and held by association. The time was found to be very short, not
more than five or ten seconds.
Smith, Theodate L. : On Muscular Memory. Ibid., Vol. 7, pp.
453-490 (1896).
A painstaking comparative study of the memory of nonsense syl-
lables learned with and (as far as possible) without the cooperation of
the vocal mechanism. The memory assisted by even incipient move-
ments was, in all cases, distinctly better, — a result further confirmed
by a similar study on various combinations of the manual signs of the
deaf-mute alphabet learned with and without execution of the hand
postures involved.
COLEGEOVE: The Time required for Recognition. Ibid., Vol. 10,
pp. 286-292 (1899).
A chronoscopic study of the time required for deciding whether a
picture suddenly presented had been seen before or not.
Psychology. 127
Psychology of Movement.
Bryan, W. L. : On the Development of Voluntary Motor Ability.
Ibid., Vol. 5, pp. 125-204 (1892). (Dissertation.)
A study of the rate, precision, and strength of voluntary movements
in the case of adults, and of a large number of school children from six
to sixteen years old. Differences due to fatigue, to increasing age, to
sex, to bilateral asymmetry, and the like, are carefully worked out; the
mathematical treatment of the statistics (thanks in part to suggestions
from Dr. Boas) is unusually full and rigid.
Reigart and Sanfokd: On Reaction-times when the Stimulus is
Applied to the Reacting Hand. Ibid., Vol. 5, pp. 351-355
(1893).
The experiments bring into question the statement of Exner that
reactions are slower when the stimulus is applied to the reacting hand.
Hancock: A Preliminary Study of Motor Ability. Pedagogical
Seminary, Vol. 3, pp. 9-29 (1891).
The Relation of Strength to Flexibility in the Hands of Men
and Children. Ibid., Vol. 3, pp. 308-313 (1895).
The first is a study of the spontaneous movements of school children
from five to seven years old, — of the swayings and tremors displayed
in efforts to stand still with eyes open or closed, or to hold the hand or
forefinger still, — movements analogous to those of nervous disease. The
second paper shows for the persons tested (20 men, 22 boys, and 11
girls), greater flexibility in the hands of the men as measured by the
extent to which the joints could be flexed voluntarily. Both papers are
of avowedly pedagogical interest.
Lancaster : Warming Up. Colorado College Studies, Vol. 7, pp.
16-29 (1898).
Based upon ergographic experiments.
Sensation and Perception.
Scripture : Einige Beobachtungen iiber Schwebungen und Differenz-
tone. Philos. Studien, Vol. 7, pp. 630-632 (1892).
A brief experimental study of beats and difference tones produced by
forks sounding separately on either side of the head.
128 Department of
Dresslar: On the Pressure Sense of the Drum of the Ear and "Fa-
cial Vision." Am. Jour, of Psy., Vol. 5, pp. 344-350 (1893).
The study shows that the faculty of the blind of recognizing the
presence or absence of neighboring objects, which has been credited to
some sort of obscure visual sensation in the skin of the face, or to sen-
sations of pressure mediated by the drum of the ear, is probably a
matter of hearing.
Krohn : An Experimental Study of Simultaneous Stimulation of the
Sense of Touch. Journal of Nervous and Mental Disease, N. S.,
Vol. 18, pp. 169-184 (1893).
Based chiefly on experiments made in the Clark laboratory.
Leuba: a New Instrument for Weber's Law, with Indications of a
Law of Sense Memory. Am. Jour, of Fsy., Vol. 5, pp. 370-384
(1893).
Weber's law demonstrated in the classification of artificial stars.
The law of sense memory suggested is that memories of intensities of
sensation tend to shift toward the middle of the usual scale of intensities.
Dresslar : A New Illusion for Touch and an Explanation for the
Illusion of Certain Cross Lines in Vision. Ibid., Vol. 6, pp.
275-276 (1894).
This illusion is similar to that of the PoggendorfE illusion in vision,
and the obvious explanation in the case of the touch illusion is extended
to the visual one.
Sanford: a New Visual Illusion. Science, Feb. 17, 1893.
A visual illusion involving false judgments.
Dresslar : Studies in the Psychology of Touch. Am. Jour, of Psy.,
Vol. 6, pp. 313-368 (1894). (Dissertation.)
The study is in three sections : 1. On the Education of the Skin with
the ^sthesiometer, particularly of its bilateral effects ; 2. Experiments
on Filled and Open Space for Touch, showing that filled space seems
larger when the finger moves over it, or when the extents compared are
moved under the resting finger ; 3. On Apparent Weight as affected by
Apparent Size and Shape — tests upon school children and adults.
Psychology. 129
Circulation and Respiration.
Dawson : Effects of Mental States upon Circulation.
(Records in the instructor's hands but not worked up as yet.)
Preliminary note in the Proc. of the Am. Psychological Ass'n,
Psychological Review, Vol. 4, pp. 119-121 (189T).
An extended study made with the plethysmograph applied simidtane-
ously to the hand and eye.
Whipple : The Influence of Forced Respiration on Psychical and
Physical Activity. Am. Jour, of Pay., Vol. 9, pp. 560-571 (1898).
The effect of very rapid breathing on eight simple tasks involving
sensory or motor activities, or both. Effects slight in most cases ;
physical strength and endurance seem to be increased, while discrimi-
native powers seem to be depressed.
Comparative Psychology.
Kline : Methods in Animal Psychology. Ihid.^ Vol. 10, pp. 256-279
(1899).
Discussion of methods, and presentation of the results of experiments
upon vorticellae, wasps, chicks, and white rats.
Small, W. S. : Notes on the Psychic Development of the Young
White Rat. Ihid., Vol. 11, pp. 80-100 (1899).
The study consists of a careful record of the bodily and mental
development of the white rat from birth onward for a number of weeks.
Studies on Miscellaneous Topics.
Calkins, Mary Whiton : Statistics of Dreams. Ihid., Vol. 5, pp.
311-343 (1893).
A careful analytical and statistical study of dreams, recorded immedi-
ately after waking by two subjects during a period of six or eight
weeks. An effort to get as full a picture as possible of normal dream-
life.
LucKEY : Some Recent Studies of Pain. Ihid., Vol. 7, pp. 108-123
(1895).
A review of recent literature on the physiology and psychology of
pain.
130 Department of
Miles, Caroline : A Study of Individual Psychology. Ibid., Vol.
6, pp. 534-558 (1895).
A questionnaire study of a number of special points, made on one
hundred students in Wellesley College. Such topics are considered as :
How do you know your right hand from your left ? How do you con-
centrate attention ? Fears as children ? Things causing anger ? Favor-
ite color? Earliest memories? Early ideals? etc. (This study and
the preceding, though not experimental, were made in connection with
the work of the laboratory.)
Drew: Attention: Experimental and Critical. Ibid., Vol. 7, pp.
533-576 (1896). (Dissertation.)
The experimental portion of this paper consists of three sections :
1. Eeaction and Association Times with Differing Degrees of Distraction ;
2. A Qualitative Study of Associations with Full and with Distracted
Attention; 3. A Study of the Apparent Order of nearly Simultaneous
Stimuli with variously Directed Attention.
Hylan : The Fluctuation of Attention. Psychological Review, Mono-
graph Supplement, No. 6, pp. 1-78 (1898).
An experimental and expository paper, the experiments approaching
the question in several different ways.
HuEY : Preliminary Experiments in the Physiology and Psychology
of Reading. Am. Jour, of Psy., Vol. 9, pp. 575-586 (1898).
Tests of rate of reading in vertical and horizontal directions, of the
importance for recognition of the first and last parts of words, and of
the actual movements of the eye in reading, determined by apparatus
attached to the eye. This study was continued during the year 1898-99,
with results that are nearly ready for publication.
Technical Matters.
The following papers have been chiefly concerned with technical
matters and apparatus.
Scripture : Psychological Notes. Ibid., Vol. 4, pp. 577-584 (1892).
On the method of regular variation ; The least perceptible variation
in pitch ; The faintest perceptible sound ; Notation for intensity; A con-
stant blast for acoustical purposes ; Some psychological terms.
Scripture : An Instrument for Mapping Hot and Cold Spots on the
Skin. Science, Vol. 19, p. 258 (1892).
Psijcliology. 131
Dkesslar: a New and Simple Method for comparing the Perception
of Rate of Movement in the Direct and Indirect Fields of Vision.
Am. Jour, of Psy., Vol. 6, p. 312 (1894).
Sanfoed: a Simple and Inexpensive Chronoscope. Ibid., Vol. 3, pp.
174-181 (1890).
A New Pendulum Chronograph. Ibid., Vol. 5, pp. 384-389
(1898).
Some Practical Suggestions on the Equipment of a Psychologi-
cal Laboratory. Ibid., Vol. 5, pp. 429-438 (1893).
Notes on New Apparatus. Ibid., Vol. 6, pp. 575-584 (1895).
The Vernier Chronoscope. Ibid., Vol. 9, pp. 191-197 (1898).
While these studies have been going on in the laboratory, the work
in philosophy and education, and in the non-laboratory sections of
psychology, has been carried forward with perhaps even greater vigor.
President Hall, Dr. Burnham, Dr. Boas, Dr. Chamberlain, Dr. Meyer,
Messrs. MacDonald, Strong, Gilmau, and others, have lectured on various
aspects of the history of philosophy, pedagogy, psychiatry, aesthetics,
criminology, and anthropology. Some account of the work in education,
anthropology, and psychiatry will be found below in the special reports
of Drs. Burnham, Chamberlain, and Meyer; the rest will be spoken of
here.
The work of instruction has been carried on by means of seminaries as
well as lectures, and to a great extent also in the more informal but most
effective way of personal conference with individual students.
It is not possible from data now at hand to give a complete list of the
courses given by President Hall, but at different times he has lectured
upon the History of Philosophy, Ancient, Mediaeval, and Modern (taking
philosophy in a sense wide enough to include psychology, education, and
medicine) ; on Cosmology, on General Psychology, on Morbid Psychology
(with clinics at the Worcester Lunatic Hospital), on Genetic Psychology
(both in the animal series and in the child), Educational Philosophy and
Practice, Child Study, Adolescence, Curricula, Teaching of Special Sub-
jects, and upon other pedagogical topics. In addition to these lectures,
132 Department of
President Hall has, almost from the first, conducted a weekly seminary,
meeting in the evening at his own house. Here members of the depart-
ment have reported on the progress of their investigations and received
the benefit of mutual criticism, or have united in the study of some
special author or topic. Notes of the discussions of the seminary during
a period when chief attention was given to Plato have been published by
Dr. H. Austin Aikins in the Atlantic Monthly (September and October,
1894), under the title, "From the Reports of the Plato Club." Presi-
dent Hall has also directed the research of the greater part of the men
in the department, recommending topics, methods, literature, and lines of
thought, and in some cases has gone so far as to enter into joint author-
ship with the students, taking their incomplete results and putting them
into shape for publication.
In the first years after the opening of the University, President Hall
was assisted in the philosophical teaching by Dr. Alfred Cook, Dr. B. C.
Burt, and Mr. C. A. Strong as Docents. During the year 1889-90, Drs.
Burt and Cook gave courses on Greek philosophy and on modern philos-
ophy from Locke to Kant; and in 1890-91, Mr. Strong gave a brief course
on the history of psychology among the Greeks from Thales to Aristotle,
— an abstract of the lectures being later published in the American Jour-
nal of Psychology, Vol. 4, pp. 177-197 (1891). During 1892-93, Mr. Ben-
jamin Ives Gilman, as Instructor in Psychology, lectured on Pleasure and
Pain, and pursued independent investigations on the theory of musical
consonance. Abstracts of his lectures are to be found in the American
Journal of Psychology, Vol. 6, pp. 1-60 (1893). Mr. Arthur MacDonald,
as Docent in Ethics, devoted himself to theoretical and practical studies
in criminology, lecturing on that topic during the first year of the
University and conducting a seminary, with occasional lectures, during
the second. Since 1891 all the philosophical teaching of the department
has been done by President Hall himself.
The research of this section of the psychological department has been
devoted for the most part to questions that are too large and too unman-
ageable for successful treatment in the laboratory, — questions of the
origin and development of mental life in the race and in the child, of
adolescence and sex, of emotion, of religion, and the like. Its scope and
nature will be apparent from the following list of studies: —
Psychology. 133
Child Study and Psychogenesis.
Tracy: The Language of Childhood. Am. Jour, of Psy.^ Vol. 6, pp.
107-138 (1893).
The Psychology of Childhood. Boston, 1893. 94 pp. (Includes
a reprint of the preceding.) (Dissertation.)
The first paper is a careful study of extant data on the physiology,
phonetics, and psychology of infant language, together with new mate-
rial gathered by the author. The second is a similar treatment of
sensation, emotion, intellection, and volition as they appear in very
young children.
Shaw : A Test of Memory in School Children. Pedagogical Semi-
nary, Vol. 4, pp. 61-78 (1896).
An account of tests made with a carefully prepared story, which was
read to the children to test memory and lines of greatest interest.
Statistics of about seven hundred papers from children ranging from the
third year of school life to those in the higher classes of the high school.
Hall and Ellis: A Study of Dolls. Ihid., Vol. 4, pp. 129-175
(1896).
A study of the various aspects of the interest in dolls and of ways in
which they are used in play, based upon numerous replies to two qii.es-
tionnaires.
Small, M. H. : The Suggestibility of Children. Ihid., Vol. 4, pp.
176-220 (1896).
A record of experiments both on groups of children and on separate
individuals, together with a large number of returns from a question-
naire, with pedagogical inferences and applications.
Curtis : Inhibition. lUd., Vol. 6, pp. 65-113 (1898). (Dissertation.)
The four sections of the paper present : 1. A Summary of Facts and
Theories, Psychological, Biological, and Neurological ; 2. An Account of
the Influence of Different forms of Activity on one Another ; 3. A Study
of Kestlessness in Children ; and 4. Pedagogical Inferences from the Fore-
going. The third section gives results of experiments and observations
by the author together with questionnaire returns. The term " inhibition "
is taken in a very wide sense.
Partridge: Reverie. Ihid., Vol. 5, pp. 445-474 (1898).
A study of 337 questionnaire returns on day dreams and related phe-
nomena. The physical signs, the subjective state, the causes and condi-
134 Department of
tions, the content, and the awakening are considered. An appendix
contains records of the efforts of 330 children to describe an imaginary
animal, and of an attempt to gather statistics as to hypnagogic images
from upward of 800 children.
Dawson : A Study of Youthful Degeneracy. Ihid.^ Vol. 4, pp.
221-258 (1896).
A careful study of about 60 degenerate youths (including 26 boys
and 26 girls from the state reform schools of Massachusetts) as to
Vitality, Head and face configuration, Anomalies of physical structure,
Keenness of senses, Intellectual ability. Parentage, and Environment.
Hall: Some Aspects of the Early Sense of Self. Am. Jour, of Psy.^
Vol. 9, pp. 351-395 (1898).
A study of the growth and development of self-consciousness based
on questionnaire returns. Making acquaintance with hands, feet, and
other parts of the body, external and internal ; influence of dress
and adornment ; experiences with mirrors ; various pet names ; childish
. conceptions of the soul ; questionings of children about their own identity,
present reality, etc.; the effect of social environment, beginning espe-
cially with the mother.
Psychology of Religion.
Daniels: The New Life: a Study of Regeneration. Ihid.., Vol. 6,
pp. 61-106 (1893). (Dissertation.)
A study of adolescence in its anthropological and psychological as-
pects, with special reference to conversion and other religious experi-
ences occurring at that period, the whole being an effort to show the
means by which the fundamental truths of religion and theology may be
restated in accord with science and life.
Leuba : A Study of the Psychology of Religious Phenomena. Ihid..,
Vol. 7, pp. 309-385 (1896). (Dissertation.)
Based upon noted cases of conversion found in religious literature, on
material gathered by questionnaire and in personal interviews. The
headings of the first part are : The religious motive, Analysis of con-
version. Sense of sin, Self-surrender, Faith, Justification, Joy, Appear-
ance of newness. The second part treats of the current doctrines of
justification, faith, will, determinism, and the doctrine of the grace of
God as related to the experiences described. An appendix contains a
number of the cases in full.
Psychology. 135
Stakbuck: a Study of Conversion. Ihid.^ Vol. 8, pp. 268-308
(1897).
Contributions to the Psychology of Religion : Some Aspects of
Religious Growth. Ibid., Yol. 9, pp. 70-124(1897). (Dissertation.)
The first paper is a study of sudden conversions ; the second of more
gradual changes of a similar character. Both are based almost exclu-
sively on questionnaire returns ; the first on 137 cases, the second on 195.
The topics in the first paper are : Age of conversion, Motives and forces
leading to conversions, Experiences preceding conversion, The change
itself. Post-conversion phenomena, Other experiences similar to conver-
sion, General view of conversion. Those of the second paper are:
Statistics of material, Adolescent phenomena. The period of reconstruc-
tion. External influences. Cases without marked stages of growth, Adult
religious consciousness, Ideals, Significance of the facts.
Leuba: The Psycho-physiology of the Moral Imperative. Ibid.,
Vol. 8, pp. 528-559 (1897).
An analysis of the phenomena of conscience, together with argument
to show that the " moral imperative " is the psychical correlate of cer-
tain activities of the cerebro-spinal system (taken as the neural basis of
the life of relation) as opposed to activities of the sympathetic system
(taken as the neural basis of the vegetative and emotional life).
Philosophy and Criticism.
KiKKPATRiCK : Observations on College Seniors and Electives in
Psychological Subjects. Ibid., Vol. 3, pp. 168-173 (1890).
A study of questionnaire returns from college seniors as to their rea-
sons for studying philosophical and psychological subjects, benefit gained,
authors most impressive, and special topics found most interesting.
Hall: Contemporary Psychologists. I., Prof. EduardZeller. Ibid.,
Vol. 4, pp. 156-175 (1891).
An account of the life and writings of Zeller.
Fkaser : Visualization as a Chief Source of the Psychology of
Hobbes, Locke, Berkeley, and Hume. Ibid., Vol. 4, pp. 230-247
(1891).
The Psychological Foundation of Natural Realism. Ibid., Vol.
4, pp. 429-450 (1892).
136 Department of
The Psychological Basis of Hegelism. Ihid,^ Vol. 5, pp. 472-
495 (1893).
These papers are the result of an effort toward a " psychology of phi-
losophy." The fu-st two trace the influence of concepts derived from
vision and from touch on the philosophic schools in question, and the
third the influence of those derived from galvanism.
Bailey : Ejective Philosophy. Ihid., Vol. 5, pp. 465-471 (1893).
An attempt to describe briefly the philosophical "signs of the
times."
Leuba : National Destruction and Construction in France as seen in
Modern Literature and in the Neo-Christian Movement. Ihid.^
Vol. 5, pp. 496-539 (1893).
A review of these topics under the following heads : Artist sensual-
ists, The quest for new sensations, Nihilism and pessimism, School of the
decadents, Literary critics, Chronicles, The tormented, The Neo-Chris-
tian movement.
Allin : The " Recognition-theory " of Perception. Ihid.^ Vol. 7, pp.
237-248 (1896).
Recognition. lUd., Vol. 7, pp. 249-273 (1896).
The first paper is a critique of a theory of perception widely held in
the past and present ; the second is an analytical, critical, and expository
account of the mental experience of recognition.
Mental and Physical Peculiarities.
Scripture: Arithmetical Prodigies. Ilid.^ Vol. 4, pp. 1-59 (1891).
Accounts of a large number of phenomenal calculators collected from
widely scattered sources ; analysis and discussion of their mental pecu-
liarities, and pedagogical inferences.
Krohjst : Pseudo-chromsesthesia, or the Association of Colors with
Words, Letters, and Sounds. lUd., Vol. 5, pp. 20-41 (1892).
A summary of literature with presentation of several new cases, and a
discussion of the theory of the phenomenon, followed by a bibliography,
LiNDLEY : A Preliminar}' Study of some of the Motor Phenomena of
Mental Effort. Ihid., Vol. 7, pp. 491-517 (1896).
A study, on the basis of a questionnaire and special tests, of the tricks
and peculiarities of movement and posture that accompany mental effort.
Psychology. 137
LiNDLEY AND PARTRIDGE : Some Mental Automatisms. Pedagogical
Seminary, Vol. 5, pp. 41-60 (1897).
A qxiestionnaire study of 495 cases of such mental automatisms as the
avoidance of stepping on cracks, counting objects unnecessarily, group-
ing objects like small patterns in wall paper into regular figures, and
the picking out the middle one of rows of objects.
Phillips : Genesis of Number Forms. Am. Jour, of Psy.^ Vol. 8,
pp. 506-527 (1897).
A study, based on over 2000 cases (974 school children, and nearly
700 normal school pupils and adults personally questioned), showing the
almost universal presence of number forms, though often in very rudi-
mentary condition.
COLEGRO VE : Individual Memories. Ibid., Vol. 10, pp. 228-255 (1899) .
(Dissertation.)
The paper is a study of some sixteen hundred replies to a question-
naire on earliest memories, period of life best remembered, forgetful-
ness and false memories, aids to memory, etc. This paper is an extract
from a more extended work on memory in general.
Emotion.
Hall : A Study of Fears. lUd., Vol. 8, pp. 147-249 (1897).
Discussion of the chief fears of seventeen hundred people mostly
under twenty-three years of age, together with description of methods
used in reducing the original reports for general treatment. Fears of
high places and falling, of losing orientation, of being shut in, of water,
of wind, of celestial objects, of fire, of darkness ; dream fears ; shock ;
fears of thunder, of animals, of eyes, of teeth, of fur, of feathers ;
special fears of persons, of solitude, of death, of diseases ; moral and
religious fears ; fear of the end of the world, of ghosts ; morbid fears ;
school fears ; and the repression of fears, — are all treated in separate
sections.
Hall and Allin: The Psychology of Tickling, Laughing, and the
Comic. Ibid., Vol. 9, pp. 1-41 (1897).
A study based upon about seven hundred questionnaire returns. The
following rubrics are treated: The Physical act of laughing. Tickling,
Animals and their acts, Eecovery from slight fear. Laughter at calamity,
Practical jokes. Caricature, Wit, Laughter at what is forbidden or secret,
at the naive and unconscious, Animal laughter, Miscellaneous items, and
Notes on literature.
138 Department of
Hall : A Study of Anger. Ibid., Vol. 10, pp. 516-591 (1899).
A general summary of very widely gathered literary material, followed
by a discussion of over two thousand questionnaire returns ; General
descriptions of the state, Causes (with many sub-heads). Subjective
variations. Physical manifestations (with many sub-heads), Anger at
inanimate and insentient objects. Venting anger. Reaction, Control,
Treatment, Miscellaneous aspects.
Miscellaneous Topics.
MacDonald : Ethics as Applied to Criminology. Journal of Mental
Science, Vol. 37, pp. 10-16 (1891).
Criminal Aristocracy, or the Maffia. Medico-Legal Journal,
Vol. 9, pp. 21-26 (1891).
Le Rossignol : The Training of Animals. Am. Jour, of Psy., Vol.
5, pp. 205-213 (1892).
A review of literature on the subject.
Kkohn : Facilities in Experimental Psychology at Various German
Universities. Ibid., Vol. 4, pp. 585-594 (1892); Vol. 5, pp. 282-
284 (1892).
Notes on Heidelberg, Strasburg, Zurich, Freiburg, Munich, Prag, Ber-
lin, Leipzig, Halle, Jena, Bonn, and Gottingen.
Lemon: Psychic Effects of the Weather. Ibid., Vol. 6, pp. 277-279
(1894).
A preliminary note on the general question.
Scott : Sex and Art. Ibid., Vol. 7, pp. 153-226 (1896).
The study traces the higher enthusiasms of art and religion, as well as
the passions of sex, to the " fundamental quality of erethism found in
every animal cell." Beginning with erethism, the following topics are
discussed : Specialization among cells, Separation of the sexes, Radia-
tion, Selection, Combat, Courting, Fear and anger. Sex and care for
young, The aesthetic capacity. Courting instinct in the lower races,
Tattooing, Clothing, Shame, Jealousy and fear. Symbolism and fetich-
ism, Phallicism, Modern phallicism, General features and laws of court-
ing. Degeneration, Perversion, Ecstasy, Esthetics, Conclusion.
Scott : Old Age and Death. Ibid., Vol. 8, pp. 67-122 (1896). (Dis-
sertation.)
Old age and death treated from biological and physiological stand-
points, together with discussion of 226 returns to a questionnaire designed
Psychology. 139
to bring out the ideas of young people and others with regard to the
aged, to death, and to a future life.
Partridge : Blushing. Pedagogical Seminary^ Vol. 4, pp. 387-394
(1897).
A questionnaire study (120 cases, all normal school pupils): Objective
and subjective aspects. After-effects, Physiology, Psychology, Blushing
and sex.
Partridge: Second Breath. Ihid., Vol. 4, pp. 372-381 (1897).
A study based upon about two hundred questionnaire returns. The
following are the headings : Physical second breath, Mental second
breath, Over-play and abandon in children, Reaction, Physiology of
second breath.
LiNDLEY : A Study of Puzzles with Special Reference to the Psy-
chology of Mental Adaptation. Am. Jour, of Psy.^ Vol. 8, pp.
431-493 (1897). (Dissertation.)
The subject is introduced by a consideration of the biology and psy-
chology of play in general, followed by the classification of puzzles.
The time and conditions of greatest interest in puzzles are treated on the
basis of questionnaire returns. This is followed by a report of extended
experiments made upon school children to discover their growth in abil-
ity to deal with the difficulties presented by puzzles.
Kline: The Migratory Impulse vs. Love of Home. Ibid., Vol. 10,
pp. 1-81 (1898). (Dissertation.)
A biological and psychological study combining the results of experi-
ments upon animals with those of a questionnaire. Such topics as the
Influence of temperature, Spring fever. Migrations of wild and domestic
animals and of man, Wandering tendency in men, women, and children,
Love of home, and homesickness, are treated.
Qfantz : Dendro-psychoses. Ibid., Vol. 9, pp. 449-506 (1898).
A study on material gathered from biology, anthropology, and ques-
tionnaire returns of the psychic influence of experiences with trees.
Biological evidence of man's descent from arboreal ancestors. Psychical
reverberations from ancestral experience. Tree worship, The life tree,
The tree in folk-medicine. The tree in child life. The tree in poetry.
Bolton, F. E. : Hydro-psychoses. Ibid., Vol. 10, pp. 171-227
(1899). (Dissertation.)
A study, similar to the last, on the psychic effects of experiences with
water : Evidences of man's pelagic ancestry, Origin of animal life, Ani-
140 Departme7it of
mal retrogression to aquatic life, Water in primitive conceptions of life,
in philosophical speculation, Sacred waters. Water deities, Lustrations
and ceremonial purifications by water, Water in literature, Feelings of
people at present toward water.
GODDARD : The Effects of Mind, on Body as evidenced by Faith
Cures. Ihid., Vol. 10, pp. 431-502 (1899). (Dissertation.)
"■ Christian Science," " Divine Healing," hypnotism and other forms
of mental treatment of disease are briefly considered ; and " Mental Sci-
ence," taken as a type, is treated fully from data gathered by extended
correspondence and from hospital records. In the remainder of the
paper the following topics appear : Positive testimony of the influence
of mind on disease. Failures in the practice of mental therapeutics.
Hypnotism as a therapeutic agent, Theory of mental therapeutics. Psy-
chological problems suggested. Resume and conclusions.
Street : A Genetic Study of Immortality. Pedagogical Seminary^
Vol. 6, pp. 267-313 (1899). (Dissertation.)
A study of the origin and characteristics of ideas of the soul, im-
mortality, heaven, and a future life, made on the basis of the reports
of the thoughts of deaf mutes before training, on about five hundred
replies to a questionnaire, and on other material. Biological, psychologi-
cal, and moral aspects of the belief in immortality are also considered.
Besides the studies of these lists, which have been j)rinted, a number
more have been made and are in the hands of the instructors practically
ready for publication. Others still have been made and the data sub-
mitted without complete writing out ; a good part of these will ultimately
be made use of either in themselves or as the basis for further research
along the same lines.
After this outline of work done in the past, a few words may be per-
mitted with reference to the future of the department. This, like its
past, must be closely connected with the general progress of ]3sychological
science, and the question naturally becomes that of the directions in which
progress may be most reasonably expected. Let me begin, as before, with
the laboratory.
It seems to me that the two lines of greatest promise, conceding readily
Psychology. 141
the importance of continuing research along lines already undertaken, are
those of comparative and of individual psychology. Work has already
been begun in both fields. Especially in comparative psychology much
has already been done by the biologists, but much remains yet to be done.
There is surprisingly little accurate knovv^ledge of the mental life of even
the commonest animals ; there are many anecdotes, but not many reliable
observations, and very few experiments. In this field lie the questions of
instinct and heredity, belonging alike to psychology and biology, to which
run back so many of the most fundamental and practical of even strictly
psychological questions. Much may also be expected from the full intro-
duction into psychology of the comparative method which has so broad-
ened and enriched other sciences in which it has been applied. The
conception of mind, as of something not narrowly human or confined to a
few higher animals, but as in some sort present in all animals, even the
lowest, with a history as long as evolution, opens up vistas to which psy-
chologists have been too little accustomed. Much surely is to be expected
from this closer alliance of psychology with biology.
While the theoretical interest of comparative psychology is thus
hardly to be overestimated, the practical interest of the efforts toward an
individual psychology is hardly less important. We know something
about the mental differences of our fellow-men, but we know very little
about them in a scientific way. What underlies temperament? What
are the laws of the growth of character? Why do some pupils do well
with some teachers and not with others ? What is the best treatment for
reform school boys ? How shall one deal with exceptional and peculiar
children in the family? Individual psychology ought to answer such
questions as these, and many others. It is clear, of course, that many of
these questions extend far beyond the possibilities of the laboratory, but
the methods and standpoint and training of the laboratory will play no
small part in their final solution, and justify attacking them from that
side.
Closely connected with individual psychology, but lying a little fur-
ther from the laboratory, is another field which might be called the
" psychology of the permanent apperceptive groups " — the study of the
mental attitudes, that is, that result from the fundamental experiences of
life, a study of appercei)tion which does not stop at demonstrating the
fact of mental habit, but goes on to investigate the effect of one sort of
mental habit upon the rest ; how, for example, the fact of fatherhood or
142 Department of
a severe sickness may alter character distinctly and permanently. These
topics have not been neglected, but many questions remain that would
well repay the worker of proper equipment and insight. Coordinate with
these are the study of the more complex emotions, of religion and of
aesthetics, all of which promise much and should have an important place
in a psychological department as a counterweight to the laboratory. It
is on the data obtained from the study of these topics and those of the
last group, with others like them, that true mental and moral hygiene
must rest. Fortunately, here also we have beginnings.
Beyond these again, there are topics of great popular interest, like
those of Christian science and psychical research, upon which the lay-
man has a right to ask an expert opinion from science, and on which
psychology, after careful investigation, can and ought to speak.
What any particular department of psychology can do in realizing
these promises of the future, must depend upon the resources in men and
materials that it can command. Work in comparative psychology can be
begun at once wherever suitable accommodations can be provided for the
animals, — proper housing, cages, aquaria, and such attendance as shall
insure the health and happiness of the animals, which are essential factors
in any reliable study of their behavior, — and a properly qualified observer
can be secured. The first of these requirements is easier to fill at present
than the second, for as yet too few persons have equipped themselves both
as psychologists and naturalists, but this lack will not long exist if the
subject is taken up in earnest. For the portion of individual psychology
that comes within the scope of the laboratory, there is need of new instru-
ments of at least a relative precision, many of which must yet be devised
or slowly perfected by trial and failure, which involves a liberal subsidy.
For any of the more general problems mentioned, the first requisite is
men of proper natural equipment and training. Not every man of learn-
ing is fitted to handle them, and those devoted to them must not be so
much taken up with the routine and responsibility of elementary teaching,
that they lack the time and spirit for ardent research. And these men,
once secured, must be liberally supplied with such help in the way of
books and other materials as they need. Of these three things, — quarters
for comparative psychology, apparatus for individual psychology, and an
enlargement of the staff, — the last is, in all ways, by far the most impor-
tant. Competent and enthusiastic investigators can work with inadequate
facilities, but no facilities can take the place of the men or of the freedom
Psychology. 143
from routine teaching. The Clark department has already made such
efforts in all these lines as its opportunities have permitted. Its ten years'
history justifies the prophecy that, with enlarged opportunities, it would
make more than commensurate return in an increase of the advanced
teaching and research for which it was originally organized.
PSYCHO-PATHOLOGY.
By Adolf Meyer.
It is hardly necessary to insist to-day on the remarkably suggestive
influence which pathology has had on the biology of man, and especially
on psychology. Many of the most fundamental changes in psychology
are directly traceable to problems furnished by the study of abnormal
life, clinical and post-mortem pathology, and experimental reproduction
of diseases and of symptom-complexes. Under these conditions it is
evident that the curriculum of a psychologist, and of biologists generally,
is quite incomplete without, at least, some touch with results and problems
of general pathology, and more especially of neuro- and psycho-pathology.
Starting from the experience that certain types of psycho-pathology
lead very promptly into paths which have nothing to do with biology,
and put themselves directly on pre-biological traditions, it was considered
best to develop a course which would begin with the principles of general
pathology, the abnormalities of the most general biological factors, i.e.
with a chapter properly belonging to any general biology. In this
field, the experience in the domain of neurology and of psychiatry
would have to be worked up more carefully, as far as possible in constant
touch with the broader biological concepts.
Medicine, barely deserving the attribute of an applied science, is
not rich in literature breathing the biological spirit. To a great extent
it stands on a pre-biological, materialistic standpoint, and the orthodox
practitioner of medicine is usually anxious to keep to materialism and
to profess ignorance of the psychological aspect ; and, again, many of
those who look upon the psychological manifestations in their patients
very rapidly acquire one of the traditional exclusive standpoints, danger-
ously near certain mystical concepts. The psychology of hypnotism,
of hysteria, even that of aphasia, give good instances of such tendencies.
It is consequently desirable to build up a course from the elementary
to the more difficult, and starting from the least contested foundations
to proceed to the less comprehensible points.
144
Psycho-Pathology. 145
The plan outlined in the lectures and clinics of the spring of 1897
gives an idea of the work.
The course during the year covered the following ground : —
1. Introductory remarks on general biological conceptions. The gen-
eral biological principles applied to the study of abnormal life. Relation
between neurology and psychology, neuro-pathology and psychiatry, neuro-
logical and psychical phenomena from the biological standpoint. Appli-
cation of the point of view to alcoholic intoxication and to several forms
of mental disease. Demonstration : Cases of Febrile Delirium, General
Paralysis, Catatonia, and Idiocy.
2. Review of the general pathology on the grovmd of the aspect-
hypothesis. The terms " disease," " residual," " defective formation," and
"defective Anlage." Clinical and post-mortem pathology and their share
in general pathology. Only clinical pathology furnishes data on the psy-
chological and physiological side. Plan of clinical study. Anatomical
study. Our knowledge of the macroscopic and microscopic lesions
of the nervous system and the underlying pathological processes,
defective growth and nutrition, intoxication, abnormal function. Local
disorders : Abnormal circulation, local intoxications, traumatic disorders,
over activity, perverted function. Demonstration of abnormal brains and
histological changes.
3. The general plan of the nervous system and illustrations of
diseases of the various parts (levels). The neural tube; the segmentary
arrangement and the elements of the segments within the lowest level.
The middle level apparatus — cerebellum, midbrain, and forebrain, and
their afferent and efferent connections. Demonstrations : (1) Traumatic
paralysis of the nervus peroneus. (2) Infantile paralysis. (3) Cases of
hemiplegia. (4) Lead paralysis (Remak type). (5) Alcoholneuritis.
(6) Locomotor ataxia.
4. The principles of localization. The meaning of the connections
of neurones by numerous collaterals, of the " interruptions of the tracts
by gray matter," of the term "centre." Description of the most
important "centres," the lesions of the apparatus of mimic movements,
the sensorimotor areas, the principal " sensory " projection fields. An
outline of the principles of aphasia and its forms, of hemianopsia.
Highest level symptoms. Demonstration : Hemiplegia with hemianop-
sia ; two cases of hemiplegia with motor aphasia ; one case of sensory
aphasia. Reference to a case of Brown-Sequard paralysis.
146 Psyclio-Pathology.
5. General outline of mental diseases. Explanation of Kraepelin's
classification. Illustration of a paradigm of mental disease : General
Paralysis, its etiolog}^ symptomatology, and principal types. Demonstra-
tion of six cases.
6. Toxic psychoses and psychoses of disturbed metabolism. Sum-
mary of the data of psycho-physiological study of fatigue and intoxication
furnished by the school of Kraepelin. Review of the methods and the
results. Application to the clinical problems. Demonstration : Delirium
Tremens, Subacute Alcoholic Insanity. Cretinism. Dementia Precox and
Catatonia.
7. Periodic Insanity compared with the types of Verbloedungs-
processe. Demonstration of further types of Catatonia and of Periodic
Insanity; "Acute Mania," "Acute Melancholia."
8. Short sketch of Senile Dementia and demonstration of a case.
Constitutional psychoses. Resume of the methods and aims of individual
psychology (Cattell, Miinsterberg, Jastrow, Kraepelin, Gilbert, Binet et
Henri, Guicciardi and Ferrari). Value of "types" of character or
constitution. Their formation. Dominant ideas. Mysophobia as a
type of Neurosis of Fear. Development of Paranoia ; cases of Paranoia.
In the spring of 1896 a similar course of demonstrations had been
given (see the outline, American Journal of Psychology, April, 1896,
Vol. 7, pp. 449-450). In the spring of 1898 only one lecture was possible
(on the methods of individual psychology, especially Kraepelin's work)
and a short course of four clinics in the spring of 1899. The desire to
extend the studies into research work has remained unfulfilled. Several
attempts failed because the possibilities for such work were not mature,
neither on the side of the hospital nor on the part of the University.
The general principles of the work at Clark University tend toward
the education of workers. So far the sub-department of psycho-pathology
has been purely didactic, covered by the lectures of President Hall, on
the topics which have specially attracted psychology, e.g.^ border-line
phenomena, as seen in neurotic people, prodigies, and geniuses ; defec-
tives, such as the blind, deaf, criminal, idiotic ; mental and nervous
diseases, epilepsy, phobias, neurasthenia, hysteria ; morbid modifications
of will, personality, emotion, etc., and by the above attempt at giving a
course with clinics based on general pathology.
The research work along these lines depends on two important condi-
tions. For systematic work the organization of a clinic is necessary,
Psyclio-Patliology . 147
and on the part of the worker a fair knowledge of general and special
pathology (in its broadest sense — the knowledge of abnormal life, not
merely pathological anatomy and bacteriology) is an absolute pre-
requisite.
A training in general and special pathology on the ground of a
complete course of biology must be regarded as an absolutely necessary
pre-requisite for research in psycho-pathology. Whether most courses
of medicine offer what is needed, and whether a medical education
should be required, is a matter of some doubt ; since much of the ordinary
medical course is business training rather than work in pathology in
the true sense of the word, leaving out almost intentionally the broader
aspects which we have to require more especially for research in our
lines ; and most of the medical courses are so overburdened that the
training in the history of human thought and philosophical criticism
is completely crowded out, and this important safety-valve and balancing
apparatus is almost missing in the medical curriculum.
The other point, the creation of clinical possibilities, is not less
difficult. Our attempt at the Worcester Insane Hospital has hardly
matured sufficiently to allow of much research work. The work which
forms the foundation of research must be done first, and the reorganiza-
tion begun in 1896 is only just beginning to furnish the material for
some studies suggested by Dr. Sanford, and some investigations on
more closely psychiatric questions.
The study of the most protracted disorders of human life requires
such a patient spirit of work and an atmosphere of such tenacious
adherence to solid working principles, that the predilection for fads
and the haste for results are nowhere more lamentable. Should it be
the good fortune of this department to get strengthened by the State,
as well as by the University, a psychiatric clinic and research-station
might grow up. Efforts of this character are being made in New York
by an institute independent of the hospitals. Our plan is rather to develop
the research-station on the basis of the clinical work. The constant con-
tact with a field of experience such as a clinic offers furnishes the safest
working basis and prevents one from running away with hasty specula-
tion derived from too limited a number of facts. The best field for
getting problems for work is that of actual observation, such as a clinic
only can afford. To pick out curiosities merely will never lead to a
psycho-pathology worth its name.
ANTHKOPOLOGY.
By Alexander Francis Chamberlain.
The history of the Department of Anthropology at Clark University
forms an important chapter in the history of the study of anthropology in
America, since it was the first educational institution to distinctly recog-
nize anthropology as a subject of graduate study leading to the degree of
Doctor of Philosophy.
The first official announcement of the University, published in May,
1889, included, under the work to be undertaken in the Department of
Psychology, the following subjects : " The Psychology of Language ;
Myth, Custom, and Belief anthropologically considered." With the
opening of the academic year, anthropology was established as Section
C of the Department of Psychology, and a laboratory and departmental
library provided, with proper facilities for original investigation and
research. The laboratory contained crania for practical study, necessary
craniographic and craniometric instruments, together with the usual tools
of the anthropologist working in the field.
The library of the University, besides a special anthropological collec-
tion, contains a very complete selection of the literature on applied ethics
(criminology), embracing the chief works of the English, Italian, French,
and German writers. In the psychological library will be found also
many works relating to the subjects which anthropology and psychology
treat of in common.
In 1889 Dr. Franz Boas (now Professor of Anthropology at Columbia
University, New York), a graduate of the University of Kiel, who was
already well known through his researches among the Eskimo of Baffin
Land and the Indians of Alaska and British Columbia, was appointed
Docent in Anthropology, which position he held until the close of the
academic year, 1891-92, when he assumed the duties of director of the
sub-department of physical anthropology at the World's Columbian
Exposition, taking with him his fine collection of crania. At the Uni-
148
Anthropology. 149
versity Dr. Boas continued his studies of the anthropology of the
Northwest Coast, paying especial attention to a monograph on " The
Mythologies of the North Pacific Coast," which he prepared for pub-
lication, and to osteological studies of the material collected during his
several journeys.
In the summer of 1890 Dr. Boas was engaged in investigating the
anthropology, ethnology, and linguistics of the Indian tribes of the coast
of British Columbia, under the auspices of the British Association for
the Advancement of Science. His report, presented to the Leeds meeting
in 1891, treated of the customs and beliefs of the Bella Coola, who were
shown to be of Salishan stock, besides containing a general review of the
physical characteristics of the Indians of the North Pacific coast, with a
discussion of the problem of mixed races. Studies of the Chemakum and
Chinook languages were also continued and articles prepared for publica-
tion. Early in 1890, the approval of the school authorities having been
obtained, an extensive series of anthropological measurements was begun
in the schools of the city of Worcester, and carried to successful comple-
tion. Preparations were also made for the inauguration of similar
investigations in other parts of the Union and in Canada. These
measurements were undertaken with the object of studying the growth
of children as influenced by varying conditions. The investigations in
Worcester were carried on by Dr. Boas, with the assistance of the follow-
ing members of the University : Dr. G. M. West, Mr. A. F. Chamberlain,
Mr. T. L. Bolton, Mr. J. F. Reigart. In the spring of 1891 preparations
were made for extensive anthropological measurements of the American
Indians, under the auspices of the World's Columbian Exposition, Dr.
Boas being placed in charge of the sub-department of physical anthro-
pology. In prosecution of these investigations, the following students of
the University, trained in the anthropological laboratory, were engaged
during the summer : Dr. G. M. West, in Quebec and the maritime
provinces of Canada ; Mr. T. F. Holgate, in eastern Ontario ; Dr. T.
Proctor Hall, in western Ontario ; Mr. T. L. Bolton, in Idaho and Utah.
Other observers were similarly employed in Alaska, British Columbia,
the northwest territories of Canada, Labrador, Dakota, Wisconsin,
Washington, Oregon, New Mexico, Yucatan, etc. The chief object of
the extensive investigation thus begun is to show the distribution of
types over the American continent, and to settle, if possible, disputed
points regarding the physical anthropology of the Indians. In the
150 Anthropology.
summer of 1891 Dr. Boas resumed his investigations of the Indians of
British Cohxmbia for the British Association, and also visited the last
survivor of the Chinook tribe, from whom he obtained very valuable
ethnologic and linguistic data.
During the academic years, 1889-92, Dr. Walter Channing, of Brook-
line, Mass., Honorary Fellow of the University, carried on original investi-
gations in the laboratory of the department.
In November, 1890, Dr. G. M. West (afterward Instructor in
Anthropology in the University of Chicago), a graduate of Columbia
College, was appointed Fellow (and afterward Assistant) in Anthro-
pology, and devoted himself to the consideration of its physical side,
taking a large part in the anthropometric investigations begun in the
Worcester schools. During the summer of 1891 Dr. West was engaged
in anthropological measurements of the Indian tribes of Quebec and the
maritime provinces of Canada. Appointed Assistant in Anthropology in
1891, he continued in that position until the close of the academic year
1891-92, when he became associated with Dr. Boas in the sub-depart-
ment of anthropology in the World's Columbian Exposition, having
charge of the anthropological investigations during Dr. Boas's absence in
Europe.
During the Docentship of Dr. Boas the lectures of the department
were as follows : —
1. A course of lectures on : Physical Anthropology, Osteology, and
particularly Craniology. The Physical Character of the living subject :
Anatomy of Races. In connection with these lectures practical work was
carried on in the laboratory.
2. A course of lectures on : The Anthropology of Africa, embracing
the consideration of the geographical distribution, physical characters,
languages, and culture of the native tribes.
3. A course of lectures on: The Application of Statistics to Anthro-
pology.
In the spring of 1892 Dr. West delivered a course of lectures on
The Growth of School Children, based upon the results obtained in the
Worcester schools. These lectures have been published in Science and
the Archiv filr Anthropologie.
In the spring of 1890 Mr. A. F. Chamberlain, a graduate of the
University of Toronto, then Fellow in Modern Languages in University
College, Toronto, who had been a student in ethnology under the late Sir
Anthropology. 151
Daniel Wilson, was appointed to the first fellowship created in anthro-
pology in the University. Previous to entering upon the course of study
for the doctorate, Mr. Chamberlain had made special investigations of
the Algonkian Indian languages, and these he continued, offering as his
thesis an original monograph, " The Language of the Mississagas of
Skugog," which was published in 1892. Other briefer essays in the
same field have appeared in the Proceedings of the Canadian Institute
(Toronto), Canadian Indian, American Anthropologist, Journal of Ameri-
can Folk-Lore, Proceedings of the American Association for the Advancement
of Science, etc., during the years 1888-99.
Time snatched from busy hours from 1891 to 1893 was devoted to
original investigations in the language and folk-lore of the Canadian
French, some results of which have been published in Modern Language
Notes (Baltimore), Vols. 6-8. In 1892 was published the result of an
extensive investigation of the use of " Diminutives in -ing,'' in the Platt-
Deutsch (Low German) dialects, another study from which field, "Color
Comparisons in the Low German Dialects," subsequently appeared.
In the spring of 1891 Dr. Chamberlain delivered a brief course of
lectures on " The Relationship of Linguistics to Psychology and Anthro-
pology." In the fall of the same year he assisted in the anthropometric
investigations carried on in the schools of the city of Worcester under
the direction of Dr. Boas, and in April-May, 1892, superintended the
measurements of some 15,000 school children in Toronto, Canada, the
results of which work are being from time to time published (see Report
of Commissioner of Education, 1896-97, Vol. 2) by Dr. Boas, under whose
auspices it was carried out.
From June to October, 1891, he was absent among the Kootenay
Indians of southeastern British Columbia and Northern Idaho, having
been selected by the committee of the British Association for the Ad-
vancement of Science to carry on anthropological investigations among
the Indian tribes of northwestern Canada. His report (discussing in
detail the ethnography, physical anthropology, mythology, and language
of this comparatively unknown aboriginal people) was presented at the
Edinburgh (1892) meeting of the Association and printed, with an
introduction by Horatio Hale, as the " Eighth Report on the Northwestern
Tribes of Canada" (London, 1892, 71 pp.). Other briefer studies,
botanical, linguistic, mythological, psychological, based upon the material
gathered during this expedition, have been published in the American
152 Anthropology.
Anthropologist^ American Antiquarian^ Journal of American Folk-Lore^
Verhandlwigen der Berliner anthropologischen Gesellschaft, Archivio per
V Antropologia, Am Ur- Quell, Science, etc. The great mass of material,
however, is still in process of preparation for publication, and will, when
complete, make some four good-sized treatises or volumes as follows : —
1. Kootenay Indian Art. An Interpretative and Comparative Study of some
Three Hundred Drawings of Natural Objects, Human Beings, Animals, etc.,
made by various Indians of the Upper and Lower Kootenay.
2. Mythology of the Kootenay Indians. A Comparative and Interpretative Study
of some Fifty Animal Tales and Legends of the Kootenay Indians. With
original Indian Text, Translation, Explanatory- Notes, etc.
3-4. Dictionary of the Kootenay Language, with Introduction on Grammar and
Morphology. Part I., Kootenay-English ; Part II., English-Kootenay.
As much time as could reasonably be spared from other duties has
been devoted to the long and difficult task of compilation and revision of
these original studies.
During his tenure of the Lectureship in Anthropology, Dr. Chamber-
lain has lectured twice a week throughout the academic year, the following
courses having been delivered : —
1892-93. Mythology of the North American Indians.
The syllabus and bibliography of this detailed interpretative study have
been published in the " Third Annual Eeport of the President to the Trustees
of Clark University," 1893, pp. 123-125, 141-161. Several of the lectures have
appeared in full, or in abstract, in the Journal of American Folk-Lore.
1893-94. General Course : The Science of Anthropology in its Eelations to
Psychology and Pedagogy. Special Courses : (a) Comparative Mythology
of Ancient Greece and Italy ; (6) Child Life among Primitive Races, the
American Indians especially.
The introductory lecture of this course, under the title ''Anthropology in
Universities and Colleges," with brief historical bibliography, has been pub-
lished in part in the Pedagogical Seminary, Vol. 3, pp. 48-60. An abstract of
one of the lectures in course (b) has appeared as "Notes on Indian Child
Language," in the American Anthropologist, Vol. 3, pp. 237-241 ; Vol. 6, pp.
321-322.
1894-95. Besides the course in General Anthropology, the following brief
special courses were delivered : Anthropology and Ethnology of Sex ; The
Child amongst Primitive Peoples ; Comparative Mythology of America and
Anthropology. 153
the Old World; Psychology of Primitive Languages; The Beginnings of
Art and Language ; The iEsthetical Ideas of Primitive Peoples.
The lectures on the " Psychology of Primitive Languages " were based upon
original investigations among the Algonkian Indians of Canada, and the Koote-
nay Indians of British Columbia, and abstracts of several of them; have been
published in the American Anthropologist, Vol. 7 (1894), pp. 68-69, 186-192 ;
VerJiandlungen der Berliner antliropologischen Gesellschaft, 1893, pp. 421-425,
1895, pp. 551-556 ; Arcliivio per V Antropologia e la Etnologia (Firenze), Vol.
23 (1893), pp. 393-399.
The lectures on "The Child among Primitive Peoples," delivered also in
popular form at the Summer School in July, 1894, have been elaborated and
published as a book, with the title " The Child and Childhood in Folk-Thought "
(New York, Macmillan, 1896).
1895-96. Besides the course in General Anthropology, the following special
and briefer courses were delivered: Anthropometry of Children and Youth;
The Emotions and their Expression among Primitive Paces ; The Idea of
the Soul among Primitive Peoples ; Crime and Degeneracy among the Lower
Paces of Man ; Origin and Development of the Family ; Sociological History
of Woman.
Two of the lectures on " The Emotions and their Expression among Primi-
tive Peoples " have appeared in part in the American Journal of Psychology,
Vol. 10, pp. 301-305, "Fear," and Vol. 6, pp. 585-592, "Anger."
1896-97. Besides the course in General Anthropology, the following briefer
special courses were delivered : The Philosophy of Primitive Mythologies ;
Origin and Development of Social Institutions; Race-Psychology; The
Anthropology of Childhood ; Civilization and Evolution.
One of the lectures in the course on "The Philosophy of Primitive My-
thology" appears, under the title "Folk-Lore and Mythology of Invention," in
the Journal of American Folk-Lore, Vol. 10 (1897), pp. 89-100.
1897-98. Besides the course in General Anthropology, the following briefer
special courses were delivered : The Anthropology of Sex ; Primitive Children
and Children of Civilized Races ; Social Evolution ; Origin and Development
of Primitive Religions ; Anthropometry.
1898-99. Besides the course in General Anthropology, the following special
briefer courses have been delivered : Child Study in Italy, Variation and
Degeneration, Heredity and Environment.
Outside of the academic and summer school courses the following
lectures and addresses on topics of general interest have been delivered
from time to time in Worcester and elsewhere : —
154 An th 1 'opology.
1892. Aims and Methods of Anthropometry. Principals and Teachers of
Grammar Schools, Toronto.
1892. Optimism. Canadian Club, Clark University, Worcester.
1893. Savage Views of Nature. Natural History Society, Worcester.
1893. The American Indian. Men's Association, Pilgrim Church, Worcester,
Mass.
1894. Woman's Role in the Development of Eeligion and Civilization. Fort-
nightly Club, Woonsocket, R.I.
1895. The World's Debt to the Red Man. Natural History Society, Sterling,
Mass.
1895. The Mother and the Child in the Story of Religion and Civilization.
South Unitarian Church, Worcester, Mass.
1896. Childhood. Conference of Lend-a-Hand Clubs, Lowell, Mass.
1896. The American Indian. Universalist Church, New Britain, Conn.
1896. The Making of Abraham Lincoln. South Unitarian Church, Worcester,
Mass.
1897. Johanna Ambrosius. Lend-a-Hand Clubs, South Unitarian Church,
Worcester, Mass.
1897. Youth. Lend-a-Hand Conference, Boston, Mass.
1897. Lincoln and Darwin. South Unitarian Church, Worcester, Mass.
1897. In Memoriam : Henry George. South Unitarian Church, Worcester, Mass.
1897. The Unitarian Church and Alcoholism. Conference of Unitarian
Churches, Barre, Mass.
1898. Primitive Nature Study. Jacob Tome Institute, Port Deposit, Md.
1899. The Child and the Criminal. Monday Morning Club (Universalist Min-
isters), Boston, Mass.
At the meetings of various scientific societies, 1890-99, the following
papers have been presented, those marked * having been published since
their delivery : —
1. American Folk-Lore Society : —
1890. *Nanibozhu among the Otcipwe, etc.
1892. *Physiognomy and Physical Characteristics in Folk-Lore and Polk-
Speech.
1892. Christ in Folk-Lore.
1893. Mythology of the Columbian Discovery of America.
1895. *Poetical Aspects of American Aboriginal Speech.
1896. *Folk-Lore and Mythology of Invention.
1898. *American Indian Names of "White Men and Women.
2. Modern Language Association of America : —
1891. *The Use of Diminutives in -inrj by some writers in Low German
Dialects.
Anthropology. 155
3. American Association for the Advancement of Science : —
1893. Primitive Woman as Poet.
1894. *Translation into Primitive Languages. (Abstract.)
1894. *Incorporation in the Kootenay Language.
1894. ^'Primitive Anthropometry and its Folk-Lore. (Abstract.)
1895. *Kootenay Indian Personal Names.
=*Word Formation in the Kootenay Language.
4. British Association for tlie Advancement of Science : —
1892. *Kootenay Indians.
1897. *Kootenay Indian Drawings. (Abstract.)
1897. *The Kootenays and their Salishan Neighbors. (Abstract.)
5. Berliner Anthropologische Gesellschaf t : —
1893. *Wurzeln aus der Sprache der Kitonaqa-Indianer.
1895. *Beitrag zur Pflanzenkunde der Naturvolker America's.
6. International Congress of Anthropology (Chicago) : —
1893. *The Coyote and the Owl. (Tales of the Kootenay Indians.)
Dr. Chamberlain has been a Councillor of the American Folk-Lore
Society (1894), Secretary of the Anthropological Section of the Ameri-
can Association for the Advancement of Science (1894), and one of the
secretaries of the Anthropological Section of the British Association for
the Advancement of Science (1897).
Since 1894 anthropology has been represented on the programme of
the Summer School of the University, and each year Dr. Chamberlain has
delivered a course of twelve daily lectures upon anthropological questions
and topics of more or less interest to the teacher and to the general public.
These courses have been as follows : —
1894. Anthropology of Childhood. (The Child Among Primitive Peoples.)
1895. Pedagogical and Psychological Aspects of Anthropology.
1896. Anthropology of Childhood. (New Series.)
1897. Anthropological Aspects of Childhood.
1898. The Beginnings of Education and Educational Institutions. — Primitive
Pedagogy.
1899. Educational Aspects of Human Evolution.
At the various summer schools the following topics have also been
popularly treated in evening lectures : —
1896. (a) The Philosophy of Childhood with the Poets.
(6) The Genius of Childhood.
156 Anthropology.
1897. (a) The Divinity of Childhood.
(6) The Attitude of Primitive Peoples toward Nature.
1898. The Childhood of Genius.
1899. (a) The Prophecy of Childhood.
(&) The Making of a Genius. (Abraham Lincoln.)
Anthropology, while comparatively a new, is by no means an uncom-
mon, subject of academic instruction, and the time has distinctly passed
when it should be called upon to plead for its existence, or to make an
oratio pro domo.
Very many of the great European universities have specifically rec-
ognized anthropology as worthy of the highest positions in their gift,
and, in this country, institutions like Harvard, Columbia, Chicago, and
the University of Pennsylvania have endued this department with the
full dignity of a professorship. Moreover, nearly twenty other colleges
and universities in America now offer instruction in anthropology, as
such, while Sociology, one of the most important branches of the science,
is to be found on the curriculum of all such institutions as are making
any efforts whatsoever to keep abreast of the times. Other branches of
anthropology, such as Comparative Philology, Comparative Religion,
Race Psychology, Anthropometry, Archaeology, Culture-History, etc., are
finding more and more acceptance with the higher institutions of learning.
Both with respect to original research and to academic lectures, the
representatives of anthropology in American universities have no reason
to fear comparison with the professors and instructors in any other branch
of science, and their influence in broadening and humanizing some of
the more belated and conservative of the kindred branches of human
knowledge can hardly be overestimated.
It is a significant fact that the latest and most complete academic
recognition of anthropology, the promotion of Dr. Franz Boas to a profes-
sorship in Columbia University, does just honor to one who began his
academic career as a Decent in Clark University in 1890. How much of
the interest in anthropology in other institutions of learning can be legiti-
mately traced to this University, which, in 1892, conferred the first Ph.D.
ever granted in America for research and investigation in anthropological
science, cannot readily be ascertained, but its influence, both direct and
indirect, has been, no doubt, as it still is, very great. Proofs of this are
not wanting in the curricula of more than one of the higher institutions
of learning, while the course in anthropology in the University of Illinois,
Anthropology. 157
offered by Dr. Arthur H. Daniels, a graduate of Clark University, is
directly due to the initiative and encouragement of the department of
anthropology.
Through the lectures delivered at the University and during the
Summer School, the anthropological department has exercised an ever
increasing influence, which has been added to by the appearance of one
series of these lectures in book form. Another point of contact with the
teaching profession throughout the country lies in the use of the depart-
ment as a sort of bureau of information upon many and varied topics of
educational science. During the last year, especially, very many requests
for such information have been received and responded to, often in detail
and as the result of personal research. To the students of the University
the department of anthropology has always emphasized the great value
of a bibliographical knowledge of the subject under investigation, and
its services have always been at their disposal.
In this University anthropology ranks as a branch of psychology, and
to promote and advance it as such has been the constant aim and endeavor
of its representative on the Faculty. The lectures have been such as to
correlate with the instruction given in philosophy, psychology, and peda-
gogy, and their object has been to furnish the students in those depart-
ments with the most recent results of anthropological investigations, and
to imbue them with that wider and deeper thought that comes from the
contemplation of the history of individual and of racial man, and to lay
firm foundations upon which in years to come may rise a complete and per-
fectly equipped department of anthropology. A glance at the theses and
essays in the departments of philosophy and psychology will demonstrate
the way in which the department has advantaged those who have pro-
ceeded to their degrees in this University, such subjects as "Regeneration,"
"Dolls," "Migration," " Hydi'o-Psychoses," " Dendro-Psychoses," "Im-
mortality," " Teaching Instinct," " Philosophy of Education," "Adoles-
cence," "Degeneracy," etc., naturally calling upon anthropology for its
quota of fact and information, which has often been quite large and sig-
nificant. Especially has this been the case since "Child-study" has loomed
up so largely in the field of education, for questions of heredity and environ-
ment, recapitulation, atavism and reversion, degeneration, variation, genius,
and the like, must receive from anthropology, more or less, their true
orientation and interpretation, — the science of the child would be help-
less without the science of man, the story of the individual not half
158 Anthropologij.
understood without the story of the race. The greater prominence now
being given to individual psychology, brings psychology also into closer
and better touch with anthropology. That the first woman to hold a
fellowship in any department in Harvard University was an anthropolo-
gist is a fact, which, taken in connection with the great amount of excel-
lent original work done in anthropology by women, both in Europe and
in America, augurs well for the future advancement of the science, when
all institutions offering post-graduate instruction in anthropology and
facilities for original investigation shall have been opened to women upon
the same terms as to men. The composite character of the population of
the United States, the existence within its borders of several entirely dis-
tinct races, and the addition to these resulting from the recent acquisition
of outlying and distant possessions, must inevitably tend to make anthro-
pology more and more a real academic necessity, no less than a constant
factor in the determination of national welfare and progress. Unless
every sign fails, the history of anthropology in the next quarter century
of American university life will compare in brilliancy with that of any
other science similiarly stimulated and environed.
At this University, anthropology has accomplished, as the record of
the publications of the department shows, results out of proportion to its
financial resources and the facilities for investigation and research made
possible thereby. With other departments in the University it has striven
to overcome these serious handicaps as much as might be, and what has
already been done must serve to indicate what can be done in the future,
if the department is generously and satisfactorily endowed. Nowhere
else, perhaps, can the " sinews of science," rightly employed, give ampler
or juster returns, if the past foreshadows the years to come.
Clark University, the first institution in America to recognize anthro-
pology as a fit and proper subject for post-graduate researches and inves-
gation leading to the degree of Ph.D., and the first university to confer
such a degree, can justly hope for that recognition which comes to the
pioneers in all great educational movements.
But before the department can labor at its best, it must have the best
means of research and investigation, be equipped as well, at least, as any
similar department in any other institution in the country. Given these,
it can do as good work, or even better.
The professorships at Harvard, Columbia, Chicago, and Pennsylvania,
the Thaw Fellowship at Harvard, the library of 20,000 books and pam-
Antliroijology, 159
phlets in a single branch of anthropology at the University of Pennsyl-
vania, and the laboratory and museum facilities of all these institutions
which have come into such rich fruition during the last ten years, point
the way for us, if the good work of the past is to increase and multiply.
For comparison with the present state of affairs at this University, the
following data from the most recent official publications of the universi-
ties concerned, institutions which offer post-graduate courses in anthro-
pology and confer the degree of Ph.D. in that department, will suffice
(sociology, etc., not included): —
Harvard: Professor; Instructor; Thaw Fellow ($1050); Hemenway Fellow
($500) ; Winthrop Scholar ($200).
Chicago : Associate Professor ; one Fellow.
Columbia : Professor ; two Instructors ; President's University Scholar ($150) ;
one Fellow ; two Scholars.
One cannot escape seeing the necessity of enlargement and further
endowment at this University, if anthropology is to prosper fully.
Before the great things of which it is capable can, in all their rounded
completeness, be accomplished here, changes and improvements must
take place, and the following are among those most needed or most
desirable : —
(1) The department must ultimately be dignified by the existence
of a professorship, if it is to continue to hold its own among the similar
departments in other great educational institutions. Anthropology can
wait, as it has waited, but it scarcely deserves that refusal of academical
advancement, which is, of necessity, bound up with straitened financial
conditions.
(2) A complete departmental library, which shall include all cur-
rent periodicals and journals of anthropological interest and afford imme-
diate access to the very latest American and foreign publications in all
branches of anthropological science, is an absolute necessity. The ad-
vantage of having all these under one roof and procurable immediately
after their issuance is inestimable.
(3) A thoroughly equipped laboratory, for special researches and
investigations, is also among the things first to be desired, and what
investigators now, or formerly connected with the University, have done
in this field is a full guarantee that such an addition to the facilities of
the University would be well utilized and appreciated.
160 Anthropology.
(4) A museum, which shall contain materials and specimens illustrating
the parallel development of the individual and the race, is also a desidera-
tum, for this truly anthropological theory, so fecund for education and
psychology, has yet to undergo that stern test which zoology, palaeon-
tology, and geology have so successfully sustained.
(5) Generous endowment of fellowships and scholarships (intra-mural
and extra-mural) and other aids in investigation and field work is abso-
lutely necessitated by any adequate instalment of anthropology.
(6) More, perhaps, than is the case with most other departments, lib-
eral allowances for clerical work and for travelling expenses, the lack of
which so often delays good studies and inconveniences good men, are nec-
essary, and the department must be congratulated on what has been
achieved in the absence of all these. Often to be able means to accomplish.
Judged both by the work accomplished here and the status of anthro-
pology in other universities, the department has every reason to ask
and every right to expect such increased endowment as will enable it to
make the next ten years of its existence as notable as the same period in
the history of anthropology in any of the higher institutions of learning,
European or American.
PEDAGOGY.
By William Henry Burnham.
Soon after the opening of the University, President G. Stanley Hall
entered upon the duties of Professor of Psychology and Education.
During the first academic year no pedagogical courses were given, but
toward the close of the year Dr. William H. Burnham, the writer of this
report, was appointed Docent in Pedagogy and sent to Europe by the
University to study educational institutions, methods, etc. During the
year 1890-91, courses of lectures on pedagogy were given in the psycho-
logical department by Drs. Hall and Burnham, and a seminary met weekly
for the study and discussion of educational subjects. In 1893 the educa-
tional courses were designated as a sub-department of psychology offering
a minor for the doctor's degree. But the work has remained most inti-
mately connected with that in psychology and anthropology.
In any natural development of these three subjects, the subject-matter
overlaps and is interrelated. In this University no attempt has been
made to mark a line of division between them. Specially close has been
the connection between psychology and pedagogy, most of the students
in one subject taking courses in the other. Such vital connection of the
two subjects has mutual advantages. Pedagogy is based upon psychology
and owes to it the inspiration and stimulus to scientific work, and psy-
chology owes to pedagogy the suggestion of some of its most fruitful
fields of investigation.
With a limited staff no attempt has been made to cover the whole
field of pedagogy ; but by choosing specially important parts of the field,
and by extending the courses over two or three years, an effort has been
made to show how the subject should be studied. By this method lectures
have been given on the history of the modern reform movement in educa-
tion, begun on the one hand by the early Italian Humanists, and on
M 161
162 Pedagogy.
the other by Comenius, the present organization of schools in England,
France, and Germany, the Evolution of the Teaching Profession, the
Historical and Critical Study of Educational Principles, Mental and
Physical Development, Educational Psychology, and School Hygiene,
including the Hj'giene of Instruction. Other courses have been given
by Drs. Hall, Burnham, and Lukens on the following among other
topics : History of Methods in Reading, Physical Education, Child-study,
Adolescence, Ideal School, Herbartian Pedagogy, History of Curricula,
and leading present toj^ics in education.
A great variety of subjects have been studied in connection with the
seminaries, and the results of many of these studies have appeared in the
Pedagogical Seminary, an educational journal edited by G. Stanley Hall
and published at the University, beginning in 1891. The work of the
department is best seen, however, by noting its aims, methods, and
concrete results.
The aim of the department is twofold : first, to give instruction and
training to those who are preparing to be professors of pedagogy, super-
intendents, or -teachers in higher institutions ; second, to make scientific
contributions to education. These two ends are so closely related that
the pursuit of one involves much of the work required for the other also.
Suitable preparation for the course involves so much of general edu-
cation as is usually indicated by the B.A. degree. A good reading
knowledge of French and German is of vital importance, and an acquaint-
ance with elementary psychology is desirable, it being taken for granted,
of course, that those who intend to teach have adequate knowledge in
their own special departments.
Assuming that a student has adequate preparation, three things are
essential for higher pedagogical training : first, a general knowledge of
the organization of education in different countries and of literature in the
field of education, including the history of education, psychology in its
relation to education, and school hygiene; second, actual experience in
teaching, together with observation of good teaching, and some direct
study of educational institutions of different character and grade ; third,
some experience in independent research, involving not only the thorough
study of all authorities upon a subject, and of all work that has been done
in the same field in different countries, but also original investigation
leading to a scientific contribution.
These three kinds of work may be done simultaneously or successively.
Pedagogy. 163
In some of the best higher pedagogical seminaries in Germany they are
done simultaneously. Students study and report upon educational and
psychological literature. They visit classes of different grades, observing
the work of regular teachers, and also teach in a practice school. At the
same time they endeavor to investigate some special problem. In this
University the study of educational literature, by lectures and inde-
pendent reading, and the investigation of some problem, are usually car-
ried on simultaneously ; but practical experience in teaching must be
gained before or after the University course. There are some advan-
tages in doing actual teaching simultaneously with the study and investi-
gation of educational problems. Direct experience in the school makes
investigation more vital and practical, and is an important control in
scientific research. But, while at present the University has no practice
school, as a matter of fact, most of those who have been members of the
educational department have had experience in teaching before coming
to the University ; and the lack of direct connection with the schools is
in part supplied by visits to educational institutions. Moreover, there
is no rigid line between instructors and students in the department. Both
are teachers and learners in turn. Special emphasis is placed upon the
importance of research ; and much of the time of the instructors is spent
in consultation with individual students in regard to their investigations.
President Hall especially has given a large amount of attention to direct-
ing this work. The research undertaken has been largely in the field
of genetic psychology and related subjects ; and the students have
been assisted by the instructors in psychology, anthropology, and neu-
rology. A great variety of topics, however, have been studied ; and
a large part of the investigations have yielded results for publication.
The papers ^ that have already appeared may be roughly classified as
follows : —
Contributions to the Physiology and Psychology of Development.
BOHANNON, E. W. : A Study of Peculiar and Exceptional Children.
Pedagogical Seminary^ Oct., 1896, Vol. 4, pp. 3-60.
Based upon answers to a questionnaire reporting over a thousand
cases.
1 Many of the papers mentioned in this list are quite as much products of the department
of psychology as of that of pedagogy ; and, on the other hand, tlie pedagogical department
has contributed to many of the psychological studies mentioned above.
164 Pedagogy.
BOHANNON, E. W.: The Only Child in a Family. Pedagogical
Seminary, April, 1898, Vol. 5, pp. 475-496.
From a study of reports of 381 only children, it appears that only chil-
dren are below the average in vitality and unusually subject to mental
and physical defects of a grave character, and that, lacking the impor-
tant education from the constant companionship of other children, they
need special pedagogical care and training.
BUKK, Frederick: Growth of Children in Height and Weight.
Am. Jour, of Psg., April, 1898, Vol. 9, pp. 253-326.
A comprehensive resume of the numerous studies in this field, with a
discussion of their pedagogical significance.
BURK, Frederick : From Fundamental to Accessory in the Devel-
opment of the Nervous System and of Movements. Pedagogical
Seminary, Oct., 1898, Vol. 6, pp. 5-64.
A contribution to the physiology of development, especially a study
of the evolution of hand movements in the development of the normal
child. From a comprehensive review of the various neurological and
psychological studies upon this subject, the author makes among others
the following conclusion : that there is an early period in the develop-
ment of each part or process when the purpose of education must be to
follow the fixed innate heredity line of tendency (fundamental educa-
tion); that there follows a later period in an activity's development
when it passes partially out of the control of racial habit and becomes
more plastic to present environment (accessory education). Presented
as a dissertation.
BuKNHAM, Wm. H. : The Study of Adolescence. Ihid., June, 1891,
Vol. 1, pp. 174-195.
A brief introduction to the study of the adolescent problem.
BuRNHAM, Wm. H. : Individual Differences in the Imaginations of
Children. Ibid., March, 1893, Vol. 2, pp. 204-225.
Based upon literature and reports by students at the Worcester
Normal School.
Chrisman, Oscar : The Secret Language of Children. Science,
Dec. 1, 1893, Vol. 22, p. 303.
Pedagogy. 165
Croswell, T. R. : Amusements of Worcester School Children.
Pedagogical Seminary^ Sept., 1899, Vol. 6, pp. 267-371.
A study of the amusements of two thousand children based upon
reports by the children. A contribution to the problem of variation in
play as conditioned by age, sex, nationality, locality, and season. The
results indicate as characteristic of the games of adolescence the coopera-
tion of a number of individuals to secure a definite end, and the delight
in contest in contrast with the individualistic amusements of earlier
years.
Hall, G. Stanley: Initiations into Adolescence. Proc. Am.
Antiq. Soc, Worcester, Mass., Oct. 21, 1898, Vol. 12, pp. 367-400.
Includes a detailed account of certain rites of primitive peoples, and
discusses the relation of adolescent instincts in religion.
Lancaster, E. G. : The Psychology and Pedagogy of Adolescence.
Pedagogical Seminary, July, 1897, Vol. 5, pp. 61-128.
A comprehensive study by the questionnaire method. With a resume
of the work of others and practical suggestions. Presented as a disser-
tation.
YoDER, A. H. : The Study of the Boyhood of Great Men. Ihid.^
Oct., 1894, Vol. 3, pp. 134-156.
Based upon the study of a large number of biographies.
Studies of Special Branches of Education from the Genetic Point of View.
Ellis, A. Caswell : Sunday-school work and Bible Study in the
Light of Modern Pedagogy. Ihid.^ June, 1896, Vol. 3, pp. 363-
412.
An attempt to suggest the psychological method of religious instruc-
tion, together with an historical sketch of the Sunday-school idea.
Johnson, G. E. : Education by Plays and Games. Ihid.^ Oct., 1894,
Vol. 3, pp. 97-133.
Presents a classified list of about five hundred plays and games with
a study of their educational value.
HoYT, Wm. a. : The Love of Nature as the Root of teaching and
learning the Sciences. Ihid., Oct., 1894, Vol. 3, pp. 61-86.
Based chiefly upon literature, with pedagogical suggestions.
166 Pedagogy.
LuKENS, Herman T. : Preliminary Report on the Learning of Lan-
guage. Ihid., June, 1896, Vol. 3, pp. 424-460.
Traces the stages in a child's learning to talk, and presents much data
in regard to pronunciation and the development of the sentence.
LuKENS, Herman T. : A Study of Children's Drawings. Ihid.,
Oct., 1896, Vol. 4, pp. 79-110.
A genetic study based upon original reports and observations.
Phillips, D. E. : Number and its Application psychologically con-
sidered. lUd., Oct., 1897, Vol. 5, pp. 221-281.
Includes a study of over two thousand arithmetic papers prepared
by children in the schools, the results of a questionnaire research, a criti-
cal estimate of many text-books, and a discussion of the general sub-
ject from the genetic standpoint.
Street, J. R. : A Study in Moral Education. Ihid.^ July, 1897,
Vol. 5, pp. 5-40.
Based upon the reminiscent answers of adolescents to a questionnaire.
The results suggest the great role of imitation, instruction, the sentiments,
and heredity in moral action, and emphasize the significance of habit.
Street, J. R. : A Study in Language Teaching. Ihid.^ April, 1897,
Vol. 4, pp. 269-293.
Studies in School Hygiene.
BuRNHAM, Wm. H. : Outlines of School Hygiene. Ibid.., June,
1892, Vol. 2, pp. 9-71.
Includes, besides a general survey of school sanitation, brief studies
of such topics as fatigue, the period of study, school furniture, the
hygiene of writing, etc.
BuRNHAM, Wm. H. : Bibliography of School Hygiene. Proc. iV.
E. A., 1898, pp. 505-523.
A selected list of 436 titles.
Chrisman, Oscar: The Hearing of Children. Pedagogical Semi-
nary, Dec, 1893, Vol. 2, pp. 397-441.
A resume of the investigations of the hearing of school children in
different countries. Practically complete to the date of publication, with
practical suggestions collected from different authorities.
Pedagogy. 167
Dkesslae, F. B. : Fatigue. Ibid., June, 1892, Vol. 2, pp. 102-106.
An introduction to tlie general subject of mental fatigue.
Dkesslae, F. B. : A Sketch of Old Schoolhouses. lUd.^ June,
1892, Vol. 2, pp. 115-125.
A brief historical contribution to school hygiene.
Principles, Methods, and Organization of Education.
Croswell, T. li. : Courses of Study in the Elementary Schools of
the United States. Ibid., April, 1897, Vol. 4, pp. 294-335.
Devoted especially to state and city courses and legal requirements.
Ellis, A. Caswell : Suggestions for a Philosophy of Education.
Ibid., Oct., 1897, Vol. 5, pp. 159-201.
The closing chapter of an extended historical study of the philosophy
of education presented as a dissertation.
Hall, G. Stanley : Child Study the Basis of Exact Education.
Forum, Dec, 1893, Vol. 16, pp. 429-441.
LuKENS, Heemaist T. : The Correlation of Studies. Educational Re-
view, Nov., 1895, Vol. 10, pp. 364-383.
PoTTEE, J. R. : History of Methods of Instruction in Geography.
Pedagogical Seminary, Dec, 1891, Vol. 1, pp. 415-424.
Specially an account of German methods, based upon literature.
ScRiPTUEE, E. W. : Education as a Science. Ibid., June, 1892,
Vol. 2, pp. 111-114.
A plea for experimental education with report of illustrative experi-
ments.
Seaes, Chaeles H. : Home and School Punishments. 7S/t?., March,
1899, Vol. 6, pp. 159-187.
Based upon literature and the answers to a questionnaire.
The Training of Teachers.
BuEK, Feedeeick L. : The Training of Teachers. Atlantic Monthly.^
Oct., 1897, Vol. 80, pp. 547-561, and June, 1898, Vol. 81, pp.
769-779.
168 Pedagogy.
Btjrnham, Wm. H. : Higher Pedagogical Seminaries in Germany.
Pedagogical Seminary, Dec., 1891, Vol. 1, pp. 390-408.
A sketch of the history and present character of the different kinds
of pedagogical seminaries for training teachers for the higher schools in
Germany, based on literature and personal observation.
BuKNHAM, Wm. H. : Some Aspects of the Teaching Profession.
Forum, June, 1898, Vol. 25, pp. 481-495.
Hall, G. Stanley : American Universities and the Training of
Teachers. Ihid., April and May, 1894, Vol. 17, pp. 148-159,
297-309.
Hall, G. Stanley: The Training of Teachers. 75ic2., Sept., 1890,
Vol. 10, pp. 11-22.
Hall, G. Stanley : Research the Vital Spirit of Teaching. Ihid.^
July, 1894, Vol. 17, pp. 558-570.
Phillips, D. E. : The Teaching Instinct. Pedagogical Seminary^
March, 1899, Vol. 6, pp. 188-245.
A study of the phenomena of leadership and teaching among animals
and children, of the lives and motives of the great teachers, and of train-
ing in relation to the teaching instinct, including a contribution by the
questionnaire method. Presented as a dissertation.
Reigaet, J. F. : The Training of Teachers in England. Ibid., Dec,
1891, Vol. 1, pp. 409-415.
A brief sketch based upon literature.
Miscellaneous.
BuRK, Fredeeick L. : Teasing and Bullying. Pedagogical Seminary,
April, 1897, Vol. 4, pp. 336-371.
Based on returns to a questionnaire.
Hall, G. Stanley : Boy Life in a Massachusetts Country Town
Thirty Years Ago. Proe. Am. Antiq. Soe., Worcester, Mass., Oct.
21, 1890, N. S., Vol. 7, pp. 107-128.
An historical contribution showing the many-sidedness of the home
education of the New England country boy.
Pedagogy. 169
Hall, G. Stanley: The Case of the Public Schools. Atlantic
Montlily, March, 1896, Vol. 77, pp. 402-413.
Hall, G. Stanley : The Love and Study of Nature : a Part of
Education. Agriculture of Massachusetts, 1898, pp. 134-154.
Lectures delivered before the Massachusetts State Board of Agri-
culture at Amherst, Dec. 6, 1898.
Treats of the child's attitude toward nature.
Hancock, John A. : An Early Phase of the Manual Training Move-
ment. Ihid., Oct., 1897, Vol. 5, pp. 287-292.
A brief historical sketch of the old manual labor school.
Johnson, G. E. : Contribution to the Psychology and Pedagogy of
Feeble-minded Children. Ihid., Oct., 1895, Vol. 3, pp. 246-291.
Reports result of tests of memory span, motor ability, and association,
in feeble-minded children at the Massachusetts School for the Feeble-
minded at Waltham, together with an historical introduction and practi-
cal suggestions for their education.
KiSTLER, Milton S. : John Knox's Services to Education. Education,
Oct., 1898, Vol. 19, pp. 105-116.
Kline, Linus W. : Truancy as Related to the Migratory Instinct.
Pedagogical Seminary, Jan., 1898, Vol. 5, pp. 381-420.
Includes a comparison of the physical condition of truants as shown
by anthropometric tests with that of public school children.
Sheldon, Henry D. : The Institutional Activities of American Chil-
dren. Am. Jour, of Psy., July, 1898, Vol. 9, pp. 425-448.
Based largely on returns to a questionnaire.
Small, M. H. : Methods of manifesting the Instinct for Certainty.
Pedagogical Seminary, Jan., 1898, Vol. 5, pp. 313-380.
A comprehensive study of oaths based upon 2,263 answers to a ques-
tionnaire and a vast amount of literature.
Such have been the methods of the department, and such in part the
work done. The aim has been to treat a few subjects in a broad way,
170 Pedagogy.
rather than to exhaust the fiekl of conventional pedagogy. The necessity
and the advantages of this method are obvious from a brief consideration
of the subject of education, both theoretical and practical.
Jean Paul Richter quotes the French artist who required from a good
director of the ballet, besides the art of dancing, only geometry, music,
poetry, painting, and anatomy. " But," he adds, " to write upon educa-
tion means to write upon almost everything at once ; for it has to care for
and watch over the development of an entire . . . world in little, — a
microcosm of the macrocosm. ... If we carried the subject still fur-
ther, every century, every nation, and even every boy and every girl,
would require a distinct system of education, a different primer and do-
mestic French governess, etc."^ The subject of pedagogy is still more
encyclopaedic to-day than when Jean Paul Richter wrote these words.
Its foundation involves the whole physiology and psychology of develop-
ment in the individual, and the history of culture in the race, and its
superstructure includes, not only all the various forms and systems and
methods of education, but the study of the influence of environment in
the widest sense.
The conventional views minimize both the difficulties and the impor-
tance of the subject. It is said that pedagogy is applied psychology or
applied child study, and again that pedagogy must get its norms from the
history of education and from child study. This statement will do if one
knows what it involves. The history of education means the history of
civilization from its earliest traceable genesis among primitive peoples.
It means a study of types of culture and the conditions of their develop-
ment. In a word, it is a study of the evolution of education. Child
study means, too, the study of the physiology and psychology of develop-
ment in man. The science of development aims to give a complete
description of all the stages of phj'sical development from infancy to
maturity, to show their sequence and their relation to the acquisition of
organic, sensory, motor, and psychic processes. As far as psychology goes,
it is genetic psychology, which means more than is frequently connoted
by child study. Adult psychology is one thing, relatively fixed, except
for variations incident to environment or the individual. Child psychol-
ogy, even for a single individual and a given environment, varies con-
tinually because the individual is in the process of growth and rapid
development of function. It is one thing for the infant, a very different
1 Richter, " Levana, or the Doctrine of Educatiou," Author's Preface.
Pedagogy. 171
thing for the child who can walk and talk, still another at that plateau in
the curve of development that seems to come somewhere between nine
and twelve for girls and ten and fourteen for boys, still another for the
adolescent. The variation is seen in the period of a single year, almost
with the changing moons. This is true, not only on account of the grosser
acquisitions, but is seen in the sequence of interests and activities. Cliild
psychology is protean. It varies not only with the individual and the
environment, but especially with the stage of development. Further, the
science of development includes comparative psychology. Not only must
the child mind be compared with the adult mind, but the stages of devel-
opment in the child should be compared with the stages of development in
animals, the faculties of the child with those in animals, the motor ability
and activities of the child with those in animals. And again, the stages
of development in the child must be compared with those in the race;
ontogenesis in relation to phylogenesis must be studied.
All this is scientific study, not directly practical. Before deriving the
norms for practical pedagogy, a propaedeutic study must be made. As
Professor James has said: " Psychology is a science, and teaching is an
art ; and sciences never generate arts directly out of themselves. An
intermediary inventive mind must make the application by using its
originality." This mediating function is represented by two somewhat
vaguely defined branches of pedagogy — educational psychology, and the
general principles and methods of education.
Again, after the general principles of education have been derived from
psychology and history, and the theoretical norms established, they must
be verified by practical educational experiments. This brings us to the
practical side of pedagogy represented by such subjects as the organiza-
tion of schools, the art of teaching, and special didactics. And parallel
with the art of teaching in its derivation from the science of development
is school hygiene, which studies especially the conditions that favor the
healthy development of the school child. Thus pedagogy is both theoreti-
cal and practical, at once a science (at least potentially) and an art.
Such is the subject which, as the Italian proverb runs, is always poor
and naked, and, in the words of a German writer, has long sat as a drudge
at the academic hearth, and whose highest recognition in the great univer-
sities has usually been as the handmaid of philosophy. Everybody
believes in education, yet few believe in pedagogy. The reasons for this
are obvious. Apart from a few fundamentals that are almost common-
172 Pedajogy.
place, pedagogy has lacked a solid body of scientific knowledge and
universally accepted principles. Worse than this, it has lacked a definite
method and a definite ignorance.
Most of the works on the history of education are padded with accounts
of second-rate writers and second-rate books that happen to be labelled
educational ; while the really great educators have often been neglected,
and educational movements have been described as isolated currents in
the progress of civilization, without regard to their vital connection with
political, social, and industrial movements. The method has been the
elementary method of studying and describing isolated facts without
regard to historical perspective and causal relations; and even the works
of the classic writers have been chiefly the repetition and recasting of a
few old truths which had been forgotten or were ignored at the time in
which the reformers lived. For example, Comenius two hundred and fifty
years ago taught that we must study nature by the inductive method
and adapt education to the sequence of the stages of natural development;
but his writings were forgotten, and again and again the reformers have
had to teach again to a new generation the simplest principles of the
Comenian didactic. Most of the books on the educational systems of
to-day, in like manner, consist of the barren details of organization and
method, and the description often of inferior teachers and schools. The
forces that have produced these teachers and schools, the significance of
the educational movements, have not been seen; and the philosophical,
social, and religious thought that has determined educational ideals has
not been studied. These isolated facts are barren. Their real signifi-
cance is in their relation to other facts. We cannot, for example, under-
stand the educational events in England to-day unless we know something
of the wider relations of the school movement. The wrangling over the
question whether the parish of Eastbourne shall have a school board,
or whether the school education of the parish shall continue to be supplied
by voluntary schools, means a great deal more than a difference in taxes
of a few pence in the pound. This petty struggle is a part of the great
movement for the disestablishment of the Church of England. The com-
missioning of a new fellow for university extension work marks another
step in the progress of the democratic ideal, which, no longer satisfied with
provision for elementary education for every child, now demands also for
each individual, according to his ability, a share in higher education. A
new endowment for a technical school by the Worshipful Society of Gold-
Pedagogy. 173
smiths, or the like, may indicate a new dread of democracy on the part of
certain monopolists quite as much as any special interest in industrial
education. Oxford itself, with all its marvellous beauty and idealism, the
stronghold of conservatism, cannot keep aloof from the great social, indus-
trial, and educational movements outside. No better illustration could be
chosen to show the progress of the democratic ideal in education. At the
beginning of Queen Victoria's reign one could not even study at Oxford
without subscribing to the Thirty-nine Articles. A few years ago Jowett
advocated opening the university honors and emoluments to the world,
admitting anybody to any university examination without restriction of
sect, class, race, age, or residence. As was remarked at the time, if fifty
or perhaps twenty years ago a radical undergraduate were to have made
such suggestions, he would have stood a chance of being expelled from the
university, as Shelley was, for blasphemy; now they are the last words
of Jowett, quoted with approval before the vice-chancellor.
To miss these larger aspects is to miss everything of permanent value.
Historical literature in education has relatively little importance for its
direct practical teachings ; but the importance of the history of education
as a culture subject can hardly be put too high. Education represents
one of the deepest human interests, more vital than politics, and well-
nigh as universal as religion. The history of education is the history of
the development of civilization. It aims at nothing less than the study
of the school as a factor in the development of culture in relation to the
other factors in education, — the home, the church, the farm, the work-
shop, the playground, and the rest. And it aims at the study of educa-
tional movements in their genesis, and in relation to political, social,
industrial, scientific, and literary movements. This involves not merely
the study of educational writers so-called and school systems, but the
study of types of culture and the causes that condition them.
Likewise in the other parts of the field the failure to recognize the
wider significance of the subjects studied, and the attempt to build sys-
tems before the foundations were laid, have brought pedagogy into disre-
pute. But in recent years the conviction has grown that educational
problems must be studied inductively ; and, better still, important contri-
butions by the inductive method have actually been made. This has put
life into the subject and given hope for the future. Take child study as
an illustration. The significance of the modern study of children is not
merely the renewed emphasis on the old truth of adapting education to
174 Pedagogy.
the stages of development, but the insight that the only way to make this
principle vital is concrete inductive study to find out just what are the
stages of natural development. Thus every fact in regard to general
development or individual variation is deemed significant, and the student
is willing to wait for a new science of development before attempting a
permanent pedagogical system.
During the past ten years the opportunities for truly scientific work
in education have been shown as never before, methods of investigation
have been demonstrated, and in part the foundations of a science have
been laid. The things now needed are trained men and facilities. With
them a solid content of scientific knowledge can be acquired that will
place historical and social pedagogy on as firm a basis as general history
and sociology, and genetic pedagogy on a scientific footing comparable to
that of psychology. School hygiene has already its methods and a solid
body of knowledge, but it needs special laboratories for instruction and
research, either independent or in connection with psychology, physiology,
and anthropology.
The work in pedagogy in this University, although the practical
aspects of the subjects studied have not been neglected, has been chiefly
in the more scientific and theoretical parts of the field. It is not less
important on this account. Pedagogical study, like research in any
other field of history or science, is valuable for its own sake without
regard primarily to practical results. It is its own justification and its
own reward. With the nucleus of solid scientific contributions that now
exists, no university can long afford to omit courses in education from its
curriculum, whether they have any practical value or not. Such scien-
tific studies, however, cannot be divorced from the practical art of educa-
tion. The studies of children have emphasized the doctrine that the aim
of childhood is its own development, and the best guarantee of normal
maturity is normal childhood and immaturity ; in a word, they have
emphasized the principles of normal development. But these principles
are no longer pedagogical abstractions ; they are greatly modifying the
practical work of education, causing greater regard for individual chil-
dren rather than uniform classes, for health rather than scholastic prod-
ucts, for a psychological order of instruction adapted to the capacity and
interests of children rather than logical sequence and articulation of
grades. In a word, they are causing courses of study and methods to be
reconstructed with regard to the one fundamental principle of fostering
Pedagogy. 175
normal growth and development. To mention a few details, ten years
ago school baths, adjustable seats and desks, and vertical script, were
vagaries of university theorists ; to-day they are deemed essentials in
the best schools. Ten years ago suggestions of periodic disinfection of
school apparatus and school text-books, of investigating pupils' individual
capacity and power to resist fatigue, and of adapting education to indi-
vidual capacity and interest, in elementary and secondary schools, were
likely to be ridiculed ; now their soundness has been demonstrated by
practical experiments.
What part this University has had in this movement, it is not easy
to say ; but it has always advocated such reforms in the regular courses
of lectures ; many addresses on topics in school hygiene and pedagogy have
been given outside the University before schools and teachers' meetings ;
students from this University have become school superintendents, teachers
in secondary schools, professors of pedagogy or psychology in normal
schools, professors of pedagogy in colleges and universities ; and teachers
and educators from all parts of the country have attended lectures on
pedagogy during the sessions of the Summer School.
To make a department of pedagogy what it should be, it is necessary
that the whole field of education be covered by lectures as far as possible,
that the more elementary courses be given every year, that research
should be extended to the multitude of topics that offer opportunity
for study. Nowhere in the world is a complete course in pedagogy
covering all the important parts of the field given. Here and there
throughout this country and Europe are offered a few truly scientific
courses, but the subject will hardly attain its due academic dignity until
somewhere in one university are given courses which approximate an
adequate treatment of the whole field. That this University might
approximate a complete course in the subject are needed an addition to
the staff, especially for the study of historical and social pedagogy, the
establishment of special fellowships for educational research, a laboratory
for school anthropometry and school hygiene, a great enlargement of the
educational museum, a pedagogical library like that of the Musee peda-
gogiqne in Paris, where educational literature of every kind, both good
and bad, may be collected ; and, finally, a model school for the objectifi-
cation of ideals, under the direction of competent teachers who should
safeguard the interests of the pupils, but offer to university students op-
portunities for observation, and in some cases for practice in school work.
176 Pedagogy.
The aim of such a course in pedagogy, like that of the more limited
course already given in this University, would be twofold : first, to con-
tribute something to the body of knowledge in regard to education, the
content of pedagogy ; and, second, to give practical training to students
preparing to become teachers. These two aims are quite in harmony,
for an essential in the training of a teacher is the development of those
permanent professional interests and that professional apperception and
prevision acquired by the study of the more scientific parts of pedagogy.
PHILOSOPHY.
By G. Stanley Hall.
In addition to my own work in psychology and education, reported
in the preceding articles by my colleagues, Drs. Sanford and Burnham,
and in editing the American Journal of Psychology and the Pedagogical
Seminary, I have lectured during the last eight years on the History of
Philosophy. This course is felt to be of cardinal importance for those
studying either psychology or education, to give them breadth of view,
to teach what great problems have interested the race, and to give a
repertory of general ideas that will obviate some of the dangers of
specialization.
The course begins with a very brief survey of Oriental speculation,
treats the pre-Socratic Greek thinkers with considerable detail and with
constant reference to their fragmentary texts. Great stress is laid upon
Plato, and from a quarter to half of all his works are read aloud by the
students in turn from Jowett's translation, and on these dialogues the
examination for the doctorate is in some part based. Even for those
who read some Greek, the use of the English translation is preferred,
because more can be gained from Plato by men of this grade by extensive
reading than by intensive and critical study of text. Discussions often
arise in this work. Aristotle is treated in the same manner, and selec-
tions and sometimes large portions of some of his works are read in
English. From twelve to twenty lectures are given on the later schools,
ending with Plotenus and Proclus. This usually concludes the work of
the first year.
Until two years ago the second year began with the rise of scholasti-
cism and the third ended with Schopenhauer, Lotze, Hartmann, and con-
temporary writers. Special effort has always been made to go considerably
outside the stock text-book field and to deal to some extent with the
history of science, with some reference to medicine and with very slight
reference to literature, art, etc. The texts of Spinoza, Locke, Berkeley,
N 177
178 Pliilosoijliy.
i
Hume, Kant, Fichte, Schelling, Hegel, Schopenhauer, and Lotze have
been used at different times and with very different results. Ethics,
logic, metaphysics, and esthetics are included in this course, and no
special courses in any of these subjects have been given, although logical
and ethical questions are treated in my psychological course. Considera-
ble time is always given to epistemology.
Two years ago, after considerable previous preparation, a course in
Christology and Patristics was inserted between the ancient and the mod-
ern course as above described. The life of Jesus was treated concisely
and reverently from the standpoint of psychology, which is felt to be very
different from that of the current lives of Jesus. This course, although
at present being repeated with amplification, is still too incomplete to
warrant any final report upon its utility. On the whole this historic
course, which occupies three years, is earnestly recommended to all stu-
dents of psychology, religion, education, or any of the humanities, and
has generally been taken by all.
During the past eight years I have opened my house one evening
every week of the academic year to all students in the department of
psychology and related themes from seven to ten o'clock. We began
by discussing philosophical topics assigned beforehand to leaders in turn.
One year most of the time of tliis seminary was devoted to reading
and discussing Jowett's Plato. ^ Schopenhauer, Kant, and Hegel were
tried for briefer periods, but gradually, as the numbers have increased
and as the rule that each man should devote a portion of his time to some
original investigation has prevailed, the evening has been occupied by
each student in turn, who presents his thesis or subject, or a part of it,
which is then freely discussed by the other members. The debates are
often animated, as nearly every standpoint is represented. There are
clergymen, young professors from other institutions, Hegelian idealists,
Kantian epistemologists, and men of empirical science, and from these
various directions nearly every subject is really illuminated. Attendance
is never enforced, and the light refreshments served in the middle of the
evening have never been an attraction, but only a welcome break from
continued tension. The attendance for the last few years has rarely been
1 See a somewhat disguised account of the first semester's work in two articles by H.
Austin Aikins, entitled "From the Reports of the Plato Club." Atlantic Monthly, Sept.
and Oct., 1894, Vol. 74, pp. 359-368, 470-480.
Philosophy. 179
under fifteen and rarely over forty, so that the entire freedom and infor-
mality of conversation has been the rule. The themes assigned in a way
described later have been presented here in so compact and forcible a
way, that the seminary has been one of the most effective agents in my
own education, and I think all its members share my sentiments in this
respect. Here the new work on which each individual is spending so
much of his year's time is pooled for the common benefit, the reader has
the healthful stimulus of emulation in interesting his audience, acquires
valuable practice in the methods of effective presentation, and always
receives help in the way of new literature, references, the pointing out
of defects in argument or method ; and conflicts are thus most surely
avoided. Often other professors from the University attend, and the list
of distinguished guests from abroad who have either participated in the
discussions or introduced matter of their own is a long and dignified one.
There is rarely any lack of interest or reluctance to discuss, and very
infrequently is the animation too great for healthful mental circulation.
Here nearly everything that has been done by the student members of
this department of the University has been carefully wrought over, some
of it more than once.
Such stimulus I believe to be unsurpassed in educational value. The
dialectic give and take of the conversational method, the mental alertness
of debate, the charm of friendly intercourse upon high themes, which
Lotze, like some of the ancients, thought the highest joy of life and the
consummate fruition of friendship, are here combined in judicious propor-
tions most favorable to growth. Some European seminaries are devoted
to discussions of minute points ; in others the student is simply a literary
forager for the professors ; quite frequently some author is read ; but for
our American needs, at least for Clark University, I think the method
now settled upon is more educative than any other that I have seen.
A word should be said concerning student lectures. At various
periods during the decade each member of the department has been
requested to take his turn in presenting some subject in due form before
the class, taking my place at the lecturer's desk, and developing his theme
with the aid of charts, blackboard, and specimens if need be; and at
the close of the lecture I have a personal interview, stating very frankly
any faults of manner, automatism, voice, method of presentation, etc.,
liable to interfere with his usefulness as instructor or lecturer. More
180 Philosophy.
often, in place of an original lecture, each man takes his turn in digesting
with extracts some book or chapter of a standard work in the history
of philosophy, with the same criticisms. This personal relation together
with the many hours spent each week with individuals, elsewhere spoken
of, has been, I believe, of great value.
At the beginning of the year (or, for those who have already spent a
year at the University, near the close of the spring term) careful lists of
subjects which seem to the instructors in the department ripe for investi-
gation are prepared. Each jots down all suggestions in this direction
during the year, and all now meet to compare themes, consider whether
they have already been treated, what new books and apparatus each will
necessitate, by what paths each can best be approached and which are
likely to yield the best and (what for thesis work is of great impor-
tance) the most certain results of value. Conferences with each indi-
vidual are then held and each is urged to select some theme, either
because it is congenial or because it represents a field he desires to enter,
and to devote some considerable portion of the year to the effort to
master it and to add something new, however small, to the sum of the
world's knowledge.
A really good subject has aspects or divisions that bring the student
into contact with each professor in the department, and each gives
everything in the way of information, stimulus, and references that he
possibly can. Our plan has always been to allow the student to print
such work over his own name and to have full credit, although he usually
makes acknowledgements at the close of his paper to his helpers. This
plan we have found very congenial and stimulating to students, and it
has avoided all questions of ownership rights in intellectual property.
Again, a good subject must be midway between a very large and general
and a very minutely special standpoint. The student must not waste his
energy in vague generalities on the one hand, nor must he be shut up to
some petty problem, perhaps fitting into and aiding the professor's special
work, being thus unduly subordinated and apprenticed to him, as is so
common in Germany. Fitting the problem to the man so that it will
enlist all his interest and focus his knowledge and effort is half the work.
In beginning more or less independent research like this, our best
college graduates are often in a sense suddenly reduced back to infancy
and need constant individual help to go alone. For the last ten years
PJiilosophy. 181
most of several afternoons a week of my own time has been given in the
laboratory, library, and conference room in trying to assist and direct
young men to launch out in some modest yet effective way, as becomes
them, on the great life of discovery. Some, often the best scholars, are
so tied to authority that it is hard for them to be brought to realize that
the best things have neither been done nor said in the world, and that
mastery of the text-book is not final. Others are strongly inclined to
repeat experiments, multiply observations, and accumulate numbers, and
find it hard to make a serious study of the real significance of their
data. Some approach subjects with preconceived ideas and speculate
in a deductive way, abhorring details which others get lost in. Every
type of philosophical opinion and every shade of temperament, every de-
gree of intellectual enterprise at almost every rate of progress, is repre-
sented. Some are strong in the literary, historical, and antiquarian side
of their topic ; others in its experimental technique or in statistical pres-
entation and tabulation or in literary form ; some at once tend to lose
themselves in aspects of the subject that are so large that, instead of com-
ing to a conclusion in an academic year, they begin to anxiously plan a
life work and anticipate remote difficulties; while others can see abso-
lutely nothing in topics of great range and significance except some over
elaborately fortified or proven fact.
This form of modern university work is a new kind of high Socratic
midwifery, but in my opinion it is the most beneficial of all the points
of contact between professor and student. Some must be encouraged;
others must be roundly scolded. Some would devote all their time to an
interesting work of this kind, while others dawdle with it as a mere side
issue of doubtful educational value. A few do not want it, but are con-
tented with receptivity of what others have done. Restless ones often
seek change of theme, so that great discretion and great patience are
needed in this work.
Its rewards, however, are incomparably great. Having once discov-
ered a fact or made ever so small an original contribution and had the
baptism of printer's ink, the novitiate is henceforth a changed man. His
ideals of culture, standards of attainment and excellence, and his methods
of work are slowly revolutionized from this centre. Instead of being a
passive recipient, his mind has tasted a free and creative activity which
puts him on his mettle like the first taste of blood to a young tiger. He
has learned that achievement and not possession is the end and aim ; his
182 Philoso2)liy.
mind has been brought to a focus in such a way that he now knows what
real concentration means as never before. He realizes that almost every
subject in the universe, if broadly seen, is connected with every other, and
that the cosmos, like his own mind, is knit together into a unity of a
higher order. In all his works and ways he is more independent and more
inclined to seek, do, know, and experience for himself. By such personal
conference with individuals at all stages of their preparation in such a
work, which need not be a doctor's dissertation and often is not, I am con-
vinced, after a decade of experience here and some years of the same work
at the Johns Hopkins, that this is the highest criterion of an academic
teacher's real efficiency in his vocation, and that it is as much above the
mass teaching of the lecture-room as talent is above mere learning. The
necessity of this work is one of the chief reasons why truly university
work must always be done, if not at small institutions, at least in squads
so small that they can be thus individualized.
Having brought this work to some degree of completion, as should be
done at the close of each academic year, even at some sacrifice of scientific
quality (because educational values should take precedence even over
this, where the two conflict), an indispensable requisite is publicity and
that without delay. Any institution or department that confers a doc-
torate upon the ground of a dissertation that is unpublished conceals that
upon which the chief value of the degree rests. The older the student
the more stress should be laid upon this part of the work as compared
with acquisition. In most departments, science is progressing so rapidly
and work is so often duplicated that the necessity of announcing before-
hand the theme of each research has often been urged, and any con-
siderable interval between the completion of a work and its publication
involves danger of anticipation by others, as well as general loss of value
from the progress of science, which is always slowly leaving everything
behind. Chiefly to avoid this danger the journals of this University
were established, in which, without the cost to the students generally
insisted upon elsewhere and vsdth the advantage of a more or less extended
international circulation among experts, everything can be speedily
brought to the knowledge of those most interested and competent. To
know that results will thus appear without delay is itself a real stimulus,
and it is fortunate that evaluation of such work is coming to be a more
and more prominent factor in determining appointments to univei'sity
positions. The quality of mind which makes success here is infinitely
Philosophy. 183
more inspiring to students, even of lower grades, than the rehearsal of
second-hand knowledge perhaps many removes from its source. Very-
much might be said upon the effect of research as a stimulant to the
teacher, while, from still another point of view, the fact that the instruc-
tor has entered the great arena and submitted his productions to the
critical estimate of experts, gives his pupils confidence in him as an
authority and not a mere echo. The provision of a sufficient number
of reprints for circulation among special journals that will notice each
work, and for exchange with other productive workers or departments, is
another one of the new university problems unknown to the college, to
the fuller exploitation of which the new journal here contemplated and
elsewhere spoken of will be devoted.
Great importance has always been attached here to the methods of
bringing students into immediate and personal contact with the latest
literature, especially upon the topics of their theses or those related to the
original researches upon which they may be engaged. The exchanges of
the journals constitute a carefully selected list of nearly three score peri-
odicals, all of which, besides those regularly subscribed for by the library,
are immediately available. Besides these the journals receive a large
number of the most important books and pamphlets within their field,
especially from American, English, French, and German houses. These
works together with the smaller resources of my own library, which
mainly supplements that of the University, are at the disposal of students,
who are often encouraged to write brief book notices for publication.
The frequent personal conferences with each student in the department
keeps the instructor's mind alert to find out and bring to the immediate
notice of each anything bearing upon his theme. Meetings are occasion-
ally held in my library, where I spend the evening going through my
shelves, taking out the books that I deem most important and that have
helped me most, briefly characterizing each, and passing it around for
actual inspection. If I had at my disposal an hour's time of a dozen of the
most eminent men to utilize in such a way as would be of greatest benefit to
me, I think I should ask them to do precisely this, for they would thus be
giving me to some extent a key to their own intellectual activity and
direction. Where this method is extended to monographs and pamphlet
publications, the collection of which our system of exchanging theses
promises to greatly enrich, its value is still greater for special students.
184 PMlosoijhy.
Genetic psychology, which one sub-department of this University so
conspicuously represents, is far larger than the child-study of mothers'
clubs or teachers' associations. It is simply the entrance of Darwinism
into the field of mind. Underneath it lies the great transforming concep-
tion that the soul is as complex, as old, and as gradually unfolded as the
body, and like it must be studied comparatively in view of all that the
psychic life of the lower or even the lowest organisms can teach us.
The new methods cross-section the old classification methods which make
memory, will, perception, imagination, etc., so many faculties, and seek to
trace the origins of the higher mental powers to their faintest beginnings
near the dawn of animal life. The most fundamental activities are those
whose roots extend lowest down in the scale of existence, and these are
also they that send their tops highest. The conception that mind, as we
know it in consciousness, has been developed out of something very differ-
ent that, like organic forms, tends to vary and change indefinitely is a
new conception and is sure eventually to reconstruct out of new and old
elements a far larger and more adequate city of Man-soul with reformed
administrative, educational, religious, and other functions. This move-
ment appears in biology in the tendency to study psychic phenomena in
the most rudimentary and microcosmic organisms. It appears again in
the new and careful studies of instinct in the higher animals, where con-
ditions can be varied and educational experiments conducted with great
precaution and detail. Another root of the genetic movement is in the
anthropology of myth, custom and belief among primitive and savage
peoples ; another in the studies of degenerative types among the defective
classes, where decay has inverted the evolutionary order.
It is on this foundation that the child-study movement rests, and its
amazing development cannot be adequately explained without a due ap-
preciation of this wider field. The minute observation and annotation,
the measuring and weighing of a single child, or the collective study of
one topic upon the basis of returns from very large numbers of children
with the help of questionnaires, anthropometric work with its carefully
wrought out averages, — all this appeals to the instinctive love of children;
out of it has grown the new conception of childhood as the most generic
period of life, wherein the limitations of individuality are not yet so pain-
full}^ apparent as in adults, and it has given us new conceptions concern-
ing the nature of genius, the laws of growth, the origin of fear, anger,
love, the conditions of health, the nascent periods of maximal interest in
Philosophy. 185
special lines and topics, until at last education seems likely to have under
it a far more solid and scientific foundation than it has ever yet attained.
While this subject has as yet occupied but a slight and recent portion of
our curriculum, so much has already been accomplished as to warrant the
very fairest hopes for the future. Among the first results likely to be
witnessed are the gradual transformation of the methods of teaching and
of investigating the problems of the special philosophical disciplines some-
what analogous to the transformation of anatomy and morphology under
the influence of embryology. How far this movement will extend among
the other university studies, and whether with or without any new coor-
dination of the successive stages of individual growth with the historic
development of different philosophical systems as first presented by Hegel,
it is impossible to foretell.
THE LIBEAEY.
By Louis N. Wilson, Librarian.
Fkom the foundation of the University the library has been consid-
ered an important factor and has received a great deal of attention
from the Founder, President, and Faculty. Immediately upon his ap-
pointment, the President requested each member of the University to
draw up a list of books in his special field, laying particular stress upon
important serials and special monographs. These lists were carefully
collated, duplicates weeded out, and arranged in order for purchase.
The total number of items amounted in June, 1889, to upward of fifteen
thousand, a very large proportion being books and journals in foreign
languages. In order to secure for the University the best possible rates,
lists of standard works, both in sets and single volumes, were submitted
for competition to a number of well-known booksellers both in this
country and in Europe. This necessitated some delay, but it was fully
warranted by the resultant saving in cost.
To illustrate this point, the figures submitted by five firms for an
identical list of 742 items are given here, viz.: $1806.30, $1810.90,
$1971.86, $2038.89, $2166.41, showing a maximum difference of $360.11.
After carefully comparing all the lists sent in, and taking into con-
sideration the condition of the books offered, orders were placed with
firms in New York, Boston, London, Paris, Berlin, Leipzig, and Vienna.
During the past few years, owing to our very peculiar and constantly
changing customs and postal regulations, it has become more and more
desirable to import from Europe through some responsible bookseller in
this country, in order to avoid the frequent and often vexatious annoy-
ances consequent upon individual importations. Having decided upon
a particular bookseller, orders were freely placed with the understanding
that the library should receive the lowest possible rates consistent with
good service, and from time to time lists were sent to other firms in order
to be assured that the agreement was faithfully carried out. A recent
187
188 The Library.
test of this kind showed the following quotations for thirty-five volumes,
1105.26, $107.57, 1120.00. In general, the plan has worked exceedingly
well.
During the summer of 1889, while these orders were being executed,
Mr. Clark placed the first books in the library by donating about thirty-
two hundred volumes. A large proportion of these, on history, biogra-
phy and travel, were given with the original bookcases as they had
stood in his own private library. Another part of the collection con-
sisted of the following sets of bound periodicals, almost all complete
down to the end of 1883 : Atlantic Monthly^ Blackwood'' s Magazine^ Cen-
tury Magazine, Cornliill Magazine, Edi7ihurgh Bevieiv, Fortiiiglitly Review,
Cientlemaii's Magazine, Harper s Magazine, JjittelVs Living Age, Macmillan''s
Magazine, North American Revieiv, North British Review, Notes and
Queries, Popular Science Monthly, Putnam's Magazine, Quarterly Review,
and Scribner's Monthly, also a set of the Report on the Scientific Results
of the Voyage of H. M. S. Challenger, during the years 1872-76. Yet a
third part consisted of a large number of rare old books, some of which
are fine examples of early printing when there was no title-page, no
pagination, date, or printer's name, and where the initial letters were
omitted to be inserted later by hand. Of these fine old volumes, the
following are mentioned as examples : —
Paulus de Sancta Maria Scrutinium scripturarum. Probably the oldest book
in cm- library, with no title-page, colophon, pagination, or signatures.
Eubricated throughout.
Rationale divinorura officiorum. Supposed to have been printed at Basle in
1474-75.
Astexanis Suma. Libri VIII., de preceptis, de virtutibus et viciis; de sacra-
mentis de sacro penitentie, de sacramento ordinis, de excommunicatione ; de
matrimonio. Venetiis, 1478.
Robert! Caraczoli de Licio de timore divinorum judiciorum ac de morte.
Nuremberge, 1479.
Albert! de Padua expositio Evangeliorum dominicalium totius anni et concor-
dancia quatuor evangelistarum in passionem dominicam a Nicolao Vinekel-
spickel. Ulm, 1480.
Sancti Thome de Aquino ordinis predicatorum super quarto libro sententiarum
preclarum opus. Venetiis, 1481.
Liber moralitatum elegantissimus magnarum rerum naturalium lumen anime
dictus. 1482.
Sancti Hieronimi Vitse Patrum Sanctorum Egiptiorum. Ntirnberg (Koburger)
1483.
The Library. 189
Blondi Flavii historiarum ab inclinatione Eomanorum Imperii, libri XI.
Venetiis per Octavianum Scotum. 1483.
Johannis de Turrecremata questionum dignissimarum cum solutionibus earum-
den, etc. Davantrise, 1484. A work of the celebrated Spanish Dominican
Juan de Torquemada.
Legende de sancti composte per Jacobo de Voragine. Venetia, 1484.
An old German almanac beautifully printed in red and black and pasted on
one of the covers of Hieronimi Vitm Fatrum. It runs from 1486 to 1579,
and was probably printed at the earlier date.
Summa Eainerij de Pisis. Venetiis, 1486.
Liber Cronicarum cum figuris et imaginibus ab initio mundi usque nunc tem-
poris Impressum ac finitum in vigilia purificationis Marie in imperiali
urbe Augusta a Johanne Schensperger. Anno ab incarnatione domini 1497.
The so-called Nuremberg Chronicle, with numerous woodcuts by Wolge-
muth, the master of Albrecht Dlirer.
Sermones Pomerii de Tempore Hyemales et Estivales et sermones quadragesi-
males per Helbartum de Themeswar. Hagenaw, 1502, With rubricated
initials.
Pauli Jovii elogia virorum bellica virtute illustrium veris imaginibus supposita,
quae apud Musseum spectantur, Florentiae, 1551.
Ramusio, Primo volume, & Terza edizione delle navigationi et viaggi. Vene-
tia, Giunti, 1563. The first volume of Ramusio's well-known collection of
voyages and travels, containing among other things Pigafetta's log during
the first voyage around the world under Magalhaes.
Missale Romanum, ex Decreto Sacrosancti Concilii Tridentini restitutum, Pii V.
Pont. Max. jussu editum. Venetiis, apud Juntas, 1602.
The Bible : that is the Holy Scriptures contained in the Old and New Testa-
ment. London, 1610. A copy of the so-called Breeches Bible.
Missale Romanum, ex Decreto Sacrosancti concilii Tridentini restitutum, Pii V.
Pont. Max. jussu editum et Clementis VIII. auctoritate recognitum. Ingol.
stadii, 1610.
Montanus (Arnoldus) De Nieuwe en Onbekende Weereld of Beschryving van
America. Amsterdam, 1671. An old description of America in Dutch.
Esquemeling (John) and Ringrose (Basil), History of the Bucaniers of America.
London, 1695. Esquemeling, who spent many years at Tortuga, gives here
a very graphic account of the buccaneers.
Armenian Bible. Venice, 1805. Fleeing from the persecution of their ortho-
dox brethren, the Catholic Armenians of the mechitaristic order established
themselves at the island of San Lazzaro, granted them by the Republic of
Venice. Many a learned volume issued from their press, of which this is
a specimen.
New Testament in Lettish language. Mitau, 1816.
Select Fables ; with cuts, designed and engraved by Thomas and John Bewick,
previous to the year 1784 ; together with a Memoir and a descriptive cata^
190 The Library.
logue of the works of Messrs. Bewick. Newcastle, 1820. Thomas Bewick
is considered the restorer of wood engraving in England.
Cookson (Mrs. James). Flowers drawn and painted after nature in India.
1834.
In addition to a number of books presented to the library by Presi-
dent Hall, we are indebted for gifts to the following citizens of Worces-
ter : Hon. George F. Hoar, Mr. Henry J. Howland, Hon. Henry L.
Parker, Mr. Samuel H. Putnam,^ the late Hon. W. W. Rice, Hon.
Stephen Salisbury, Hon. John D. Washburn, and Hon. John E. Russell
of Leicester.
To receive the books temporary wooden stacks were erected in the
main library room, and so substantially were they constructed that they
are still serviceable. Solid oak shelving was put up on both sides of the
reading-room, adjoining the main library room, with a three-foot pro-
jecting shelf three and a half feet from the floor, upon which the current
numbers of periodicals are displayed.
To the problem of cataloguing and classification, always a difficult one,
both the President and the members of the Faculty gave a good deal of
time and attention. It was felt that the scheme of classification must not
be too rigid, and that nothing should be allowed to interfere with the free
use of the books by all members of the University. The books were first
carefully classified upon the shelves by departments, and marked as
follows : —
A. Works of General Eeference. I. Psychology.
B. Journals. J. Philosophy.
C. Mathematics. K. Ethics.
D. Physics. L. Criminology.
E. Chemistry. M. Anthropology.
F. Zoology. M". Education.
G. Physiology. 0. Botany.
H. Pathology.
The various subdivisions in each department may be inferred from
that of the mathematical department.
lA copy of '■'■Justini historici clarissimi in Trogi Pompeii historias Lihri XLIIIiy
Venice, Jenson. I4.70. Dukede Noailles' copy of the editio princeps. " Viroruni Illustrium
vita: ex Plutarcho Groeco in Latinum Versce Solertiqae, cura emendatce fceliciter expUciut : ""per
Nicolaum Jensen Gallicum Venetiis Ipressoe. 1478, die. II Januarii. 2 vols. "The
Scientific Papers of James Clerk Maxwell." Edited by W. D. Niven, F. R. S. The Univer-
sity Press, Cambridge, 1890. 2 vols.
The Library,
191
C. — Mathematics.
In Mathematics, C, the books are grouped in ten divisions, designated
by the numerals 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, immediately following the let-
ter C ; every division is subdivided into sections of which each is desig-
nated by a second numeral following that indicating the division. The
cipher, 0, always denotes a miscellaneous division or section. The math-
ematical works are arranged on the shelves in accordance with the fol-
lowing classification, the subdivisions of which, however, are not all used
at present. The italicized part of each title is that printed on the sliding
shelf label.
C 1. History and Philosophy.
CI. 1. Bibliography.
CI. 2. History.
C 1. 3. Biography.
C 1. 4. Philosophy.
C 2. Collections.
C 2. 1. Works, complete and select.
C 2. 2. Compendia, Dictionaries.
C 2. 3. Tables. Formulai.
C 3. Symbolism and Operation.
C 3. 1. Symbolic Methods.
C 3. 2. Operations.
C 3. 3. Multiple Algebra (ref. C 9).
C 3. 4. Symbolic Logic.
C 3. 0. Miscellaneous Symbols.
C 4. Arithmetic.
C 4. 1. Elementary Arithmetic.
C 4, 2. Coyitinued Fractions.
C 4. 3. Numerical Series.
C 4. 4. Finite Differences and Sum-
mation.
C 4. 5. Permutations and Combinor
tions.
C 4. 6. Probabilities.
C 4, 7. Theory of Numbers.
C 5. Algebra. (Per Multiple Alge-
bra see C 3. 3.)
C 5. 1. Elementary Algebra.
C 5. 2. Determinants.
C 5. 3. TJieory of Equations.
C 5. 4. Simidtaneous Equations.
C 5. 5. Transformation.
C 5, 6. Invariants.
C 6. Infinitesimal Calculus.
C6.
1.
Limits and Infinite Series.
C6.
2.
Functions of a Real Varia-
ble.
C6.
3.
Differential Calculus.
C6.
4.
Integral Calculus.
C6.
5.
Total i)i^erential Equations.
C6.
6.
Partial Di^erential Equa-
tions.
C6.
7.
Functions Derived from
Differential Equations.
Sp^herical Harmonics.
C6.
8.
Calcidus of Variations.
C 7. Theory of Functions.
C7.
1.
General Tlieory.
C7.
2.
Algebraic Functions.
C7.
3.
Exponential and Trigono-
metric Functions.
C7.
4.
Elliptic Functions and In-
tegrals.
C7.
5.
Hyperelliptic and Abelian
Functions and Integrals.
C7.
6.
Various Functions (fuch-
siennes, etc.).
C7.
7.
Functions of Several Varia-
bles.
192
The Library.
C 8. Geometry.
C 8. 1. Elementary Geometry and
Trigonometry.
C 8. 2. Analysis Situs.
C 8. 3. Analytic Geometry in Gen-
eral.
C 8. 4. Projective Geometry. Mod-
ern Synthetic Geometry.
C 8. 5. Special Systems of Geomet-
ric Analysis.
C 8. 6. Plane Loci in particular.
C 8. 7. Loci in 8 Dimensions in par-
ticular.
C 8. 8. Hyperspace and NonrEucli-
dean Geometry.
C 8. 9. Applications of Geometry.
C 9. Extensive Algebra (ref. C 3. 3).
C 9. 1. Geometric Representation of
the Lnaginary.
C 9. 2. Quaternions.
C 9. 3. Geometric Algebras (Clif-
ford).
C 9. 4. Ausdehnungslehre (Grass-
mann).
C 9. 5. Equipollences (Bellavitis).
CO. Miscellaneous.
C 0. 1. Apparatus.
C 0. 2. Recreations, Games, Puzzles,
etc.
C 0. 9. Paradoxes and Paradoxers.
Circle-squaring, etc.
As B is the general designation of periodicals, each periodical exclu-
sively devoted to one department is designated by B, followed by the
letter of the department to which it belongs, thus :
B C. Mathematical Periodicals.
B A. Miscellaneous Periodicals. Transactions of learned societies, etc.
So long as the number of books in any section is very small, they are
grouped under the division to which that section belongs, and are desig-
nated only by the number of that division. All books which refer to
several divisions are placed in the division C 2 (collections), and all
books referring to several sections of any one division are grouped under
that division, unless they refer but slightly to more than one division or
section. Volumes of a set are not separated, but the whole set is classed
as if it were a single volume. Otherwise, every book is placed in the
narrowest division or section to which it belongs.
The library has two card catalogues : —
I. An author's catalogue arranged alphabetically with miscellaneous
and anonymous sections, so that nearly all books in the library are
represented in it.
II. A subject catalogue which is at the same time a shelf and an
inventory catalogue. This is arranged as follows : Every volume and
every pamphlet has its card, so that each card represents a volume.
All the books are classified and arranged upon the shelves according to
the departments, divisions, and subdivisions, but under each subdivision
The Library. 193
books are placed alphabetically by authors. While each case, tier, and
shelf is permanently labelled, the demarcation between the subdivisions is
made by sliding shelf label holders bearing the subject, division, and sub-
division. These label holders being movable, the subdivisions can easily
be enlarged as new books are added.
In mathematics, for instance, C 1, history and philosophy, comes first,
with the first subdivision, CI, 1, bibliography. First on the top shelf,
and therefore first in the catalogue drawer set apart for these tiers,
comes bibliography, beginning with authors in A, and so on through the
alphabet to the end of the subject. Then come history, biography, etc.,
on through mathematics and the other departments, the order of cards
being identical with the order of the books upon the shelves, reading
down the tiers as down a printed page.
In the drawers the book cards are separated by red cards projecting
on the right above the others, and on these projections the tier and shelf
divisions are marked ; they are also separated by blue cards projecting
above the others on the left-hand side, on which the subjects are marked.
Whenever the position of any book is changed, it is only necessary to
make a corresponding change in the position of its card. The shelf posi-
tion of each book is marked in pencil, not upon these cards, but upon
each card in the author's catalogue, and in the book itself, in order that it
may be readily found and replaced.
New books, after being entered in the author's catalogue, are kept in a
case reserved for them for a few weeks before being permanently placed
on the shelves and entered in the inventory catalogue.
A full list of all serial publications taken by the library is kept in a
special drawer of the catalogue case, so that a person unfamiliar with the
library may ascertain, with very little trouble, what periodical publications
are to be found here.
Worcester is fortunate in possessing an excellent Public Library of
more than 120,000 volumes, and well supplied with serial publications.
In the early years of the University, it was the hope of the Founder that
we might confine our purchases to such books and journals as were not to
be found in the Public Library, and that the two might supplement each
other ; this plan was largely carried out in the earlier years, but later the
needs of our students demonstrated the necessity of the duplication of
the more important scientific publications, though we still depend upon
the Public Library for works of a less special character, and our students
194 The Library.
have availed themselves of the library privileges thus extended to them
to the fullest extent.
Besides its indebtedness to the Worcester Public Library the Uni-
versity is under great obligations to the following for frequent loans:
Library of the Surgeon-General's Office, Washington, D.C. ; Library of
Harvard University ; The City Library Association of Springfield, Mass. ;
Boston Public Library ; Public Library, Cleveland, Ohio ; Trinity College
Library and Case Memorial Library, of Hartford, Conn. ; Library of Yale
University ; Forbes Library, Northampton, Mass. ; Library of Vassar
College ; and many others. Several of these libraries have freely lent us
books and volumes of serial publications, often of the greatest importance
to those engaged in research work. No library, however large, can hope
or expect to be prepared to meet all the calls upon it, and a glance at
the diverse and advanced character of the publications issued from this
University i shows how varied and numerous are the demands upon this
department.
To the Library of the American Antiquarian Society we are especially
indebted for the kindly spirit of cooperation invariably shown. While
strictly a reference library, its officers have ever been ready and willing to
make reasonable exceptions in aid of the cause of historical and scientific
research.
The library is a veritable laboratory, and is looked upon as a work-
room, and not as a museum with contents too sacred to be profaned by
use. It is a favorite meeting-place for professors and students, where
the heads of departments meet their men to direct their reading and
demonstrate to them how to make the best use of a well-selected collection
of scientific books. The books are readily accessible to every member of
the University, and there is no limit to the number that may be taken
out. Each one enters the volumes he takes out upon a printed form pro-
vided for that purpose ; if not returned at the end of ten days, they are
renewed by the librarian for another period of ten days, at which time
they must be returned, but may be taken out again upon the following day.
The library is open to all persons outside the University who are
interested in any of its lines, and its books are freely lent to such persons,
who are thus placed for the time being upon the same footing as mem-
bers of the University ; and, while we borrow during term time an aver-
age of fifty volumes a month, we lend as freely. The library is rich in
1 See Bibliography at the end of this volume.
The Library. 195
certain special lines, and is often used by experts from other universities,
state and national institutions.
President Hall has an exceptionally fine private library, especially rich
in pamphlets and special monographs in the various fields of philosophy,
psychology, and education. During these ten years all students have
been permitted to draw upon it as freely as upon the University library,
and the efficiency of this department has been largely due to Dr. Hall's
broad-minded and liberal conception of the function of the printed vol-
ume. In his various courses he frequently gives demonstrations of books,
pointing out the best books in each subject, the best to buy, the best to
read, emphasizing and explaining the strong points in each, etc.
In spite of the absolute freedom of the library, the loss of books has
been surprisingly small. Once a year the books are carefully checked by
means of the shelf cards, and in very few years have the losses amounted
to more than two or three volumes. The missing volumes one year fre-
quently turn up later, so that a careful estimate recently made shows the
actual money value of the books lost in ten years to be less than fifty
dollars.
Almost all who are interested in libraries have ideals as to the future
development of their special fields, and the librarian has attempted, in the
course of the past ten years, to formulate an ideal of an university library.
He alone is responsible for his views, and is encouraged to state them here
by the fact that the President and Faculty have given him the greatest
freedom and their warmest support in all matters pertaining to his de-
partment.
The ideal library should be housed in its own building, and not rele-
gated to rooms in a building constructed for other purposes. In con-
structing such a building, the chief end in view should be to provide
every facility for the use of books, and this end should never be sacrificed
for architectural features or artistic purposes. Each department in the
University should have a working library in its own rooms, but whatever
books are placed in these department libraries should be duplicated in the
main library. The building should be large enough to allow the book
shelves to be arranged around the rooms, leaving the greatest amount of
open space in the centre. Movable working desks, liberally supplied with
196 The Library.
conveniences for writing, and containing ample drawer space for note-books
and papers, are mucli to be preferred to the large fixed tables usually
found in library buildings. The shelving should be of the most approved
modern type, insuring economy of space and the proper care of the books,
and the highest shelf within easy reach from the floor. The rooms should
be provided with every possible convenience, including a sufficient num-
ber of comfortable chairs, with cozy nooks and corners inviting to a quiet
half-hour with a book, when one would otherwise be disinclined to read.
That the light should be good, the ventilation absolutely perfect, and the
attendants have but one purpose — the service of the readers — are obvi-
ous essentials.
In these days of rapid multiplication of new libraries and enlargement
of many older ones, there is a great demand for complete sets of serial
publications, and many of the important journals are growing rapidly
scarce and difficult to obtain. It is, therefore, particularly desirable in an
institution of tliis character to procure, as soon as possible, full sets of all
the serial publications in its various departments and on all allied subjects,
and every effort should be made, and no expense spared, to procure all the
scientific contributions by specialists in the work represented here, or in
departments likely to be of service in research work.
The current numbers of all these publications should be placed before
the members of the University promptly, as it is imperative that those
engaged in original investigation be advised of the latest literatiu"e on the
subject, or of the work others are doing along similar lines.
A most important part of a good library is its catalogue. The day
has gone by when men can afford to spend hours in hunting among a mass
of books to ascertain what the library possesses upon a given subject, or
to rely upon the memory of the librarian and attendants, be the}^ ever so
erudite. While, therefore, the aim should be to keep in printed and card
form a list of all the books and articles that have been written upon a
given subject, nothing should be allowed to interfere with the prompt
cataloguing under subject headings of everything that the library pos-
sesses. Two questions always arise here, first, " Where can I find a list
of all printed matter upon my subject ? " and secondly, " How much of
that printed matter is to be found in this library ? " A complete card
catalogue can be so arranged as to answer perfectly these two questions.
In this, as in every well-regulated library, printed forms should be
provided to encourage readers to make suggestions and complaints to the
The Library. 197
library coramittee ; the latter, in no case, to pass through the hands of
the librarian.
The subject of binding is always an important one, and we feel very
keenly the need of united action on the part of all the libraries of the city
in this respect. A careful inquiry has developed the fact that between
$4000 and $5000 is expended yearly by the various institutions in this
city for this purpose. There are unmistakable signs that the art of book-
binding, which has for ages commanded the services of eminent crafts-
men, as well as of men and women eminent in art, is receiving increased
attention from book lovers here, and the time may not be far distant when
this question will be taken up by a committee representing the different
libraries.
There would seem to be no reason also why the various institutions
should not, in the near future, devise a system of cooperation, as is already
proposed in Toronto, by means of which the resources of all the libraries
in the city could be drawn upon by each.
KEPOET OF THE TREASURER.
At the first meeting of the Trustees of Clark University, May 4, 1887,
Mr. Clark proposed to give : —
(1) " The sum of $300,000 (payable as the same shall be needed) to the Gen-
eral Working or Construction Fund to be applied in the erection of
buildings and equipping them with such appliances and facilities as
may be deemed necessary for putting the University in good working
order."
(2) " The sum of $100,000, the income of which shall be devoted to the support
and maintenance of a University Library."
(3) " The sum of $600,000, the income of which is to be devoted to the general
uses of the University in its support and management, and which
for the sake of convenience may be called the University Endowment
Fund."
"The Library and the Endowment Funds are never to be diminished, and
no part of the principal is in any event ever to be applied to the objects
to which the income of each is to be devoted. If by any accident or
loss, either of said funds shall at any time become impaired, then the
income of each of said funds shall be added to the principal until such
impairment is made good and the funds restored to their original
amounts."
In addition to the foregoing gifts, Mr. Clark then and subsequently
conveyed to the Trustees of the University, real estate, the valuation of
which on the books of the assessors of the city of Worcester is ^135,600.
In the Treasurer's Annual Statement for the year ending August 31,
1899, which follows, is an account of the Library and University Endow-
ment Funds.
The amounts expended for construction and equipment of buildings
under the terms of Mr. Clark's first proposal have been as follows : —
199
200
Report of
Construction of the Main University Building . . $159,780.60
Construction of the Chemical Laboratory . . . 56,131.94
Equipment of the Main Building 18,480.28
Equipment of the Chemical Laboratory .... 14,801.47
Apparatus and Supplies 29,082.73
$278,277.02
Additional land was purchased by Mr. Clark for the
University at an expense of $12,233.04
The balance to make up the proposed $300,000 . . 9,489.94
was subsequently expended in the additional equip-
ment of the different departments.
A statement of the expenses of the several departments for the years
1890-98, inclusive, including the amounts expended in the original equip-
ment above mentioned, is appended.
1890.
1891.
1892.
1893.
1894.
Mathematics . . .
$ 6,664.49
S 7,235.00
8 7,356.50
8 6,926.40
8 5,905.64
Phvsics . . .
17,214.20
7,320.98
6,768.46
3,567.78
2,330.30
Chemistry . .
25,334.24
7,491.00
6,298.46
2,693.26
1,337.64
Biologv . . .
28,083.29
15,429.70
12,732.58
3,676.47
2,066.20
Psvchology .
13,604.17
11,400.00
7,059.16
7,666.03
6,584.00
Education . .
750.00
1,550.00
1,151.25
1,586.13
1,826.87
Library . . •
15,568.04
5,733.41
1,279.84
1,334.45
2,596.33
Administration
5,829.00
2,900.00
3,000.00
3,800.00
2,600.00
Expense . .
9,067.43
5,162.92
4,183.77
8,983.01
3,773.51
Fellowships .
3,860.00
4,560.00
7,240.00
5,280.00
4,980.00
8125,974.86
§68,783.01
§57,070.02
845,513.53
834,000.49
Mathematics .
Physics . . .
Biology . . .
Psychology . .
Education . .
Library . . .
Administration
Expense . . .
Fellowships
1895.
8 5,900.00
2,329.07
2,072.74
6,015.46
1,312.29
1,628.72
2,600.00
3,434.13
4,740.00
830,032.41
1896.
5,900.00
2,393.03
2,200.00
7,010.00
1,2.50.00
1,740.16
2,600.00
4,319.80
4,620.00
832.032.99
1897.
8 5,900.00
2,948.73
2,300.00
7,010.00
1,250.00
2,456.00
2,600.00
4,237.82
3,420.00
832,122.55
1898.
8 5,900.00
2,173.00
2,054.24
6,676.33
1,250.00
3,508.48
2,600.00
3,190.93
1,500.00
828,8.52.98
the Treasurer. 201
In addition to the endowment and gifts, which have already been
referred to, Mr. Clark has given to the University for its general
purposes : —
1889-90 $12,000
1890-91 50,000
1891-92 26,000
1892-93 18,000
$106,000
The University has received from Mrs. Eliza W. Field "a fund of
$500 to be called the John White Field Fund, the income of which is to
provide for the minor needs of a Scholar or Fellow."
There was also presented to the Trustees of the University by Hon.
George S. Barton of Worcester $5000, the income of which is to be
devoted to the aid of " some one or more worthy native born citizens of
the city of Worcester, who may desire to avail themselves of the advan-
tages of the institution."
Hon. Henry L. Parker, in the summer of 1892, in behalf of many
citizens of Worcester, presented the University with a tower clock and
the sum of $781.30 to provide for its maintenance, which fund is known
as the Clock Fund.
REPORT OF THE TREASURER TO THE TRUSTEES FOR THE YEAR
ENDING AUGUST 31, 1899.
To THE Trustees of Clark University,
Gentlemen, — I have the honor to submit herewith my annual report
for the year ending August 31, 1899.
The total receipts of the University from Sept. 1, 1898 to Aug. 31, 1899,
inclusive, were .... $48,595.53
The total disbursements during the same period were . . . 37,130.27
Leaving a balance on hand Sept. 1, 1899, of $11,465.26
202
Report of
(A.)
The items of income are as follows : —
Gross Income of the University Endowment Fund .
Gross Income of the Library Fund . . . . .
Gross Income of the University . . . . .
Gross Income of the Summer School, 1899
Subscriptions to the Fund for the Decennial Celebration
From the Field Fund
Balance from previous year
Total
(B.)
The expenditures have been as follows : —
For the Department of Mathematics . . . .
For the Department of Physics
For the Department of Biology
For the Department of Psychology
For the Department of Education
Administration ........
Expense ..........
Field Scholarship
Expenses of Summer School
Expenses of the Decennial Celebration . . . .
Library Expenses ........
Sinking Fund .........
Jonas G. Clark on account of premiums . . . .
Accrued interest repaid
(C.)
The incidental earnings of the University from fees, etc., were
(D.)
Account of the Summer School for 1899 : —
Receipts
Expenses
Balance carried to University Account
(E.)
Subscriptions to the Decennial Celebration : —
Receipts
Expenses ...........
Balance on hand appropriated to the publication of this volume
$28,407.33
5,258.46
1,586.00
1,388.50
4,150.00
20.00
7,785.24
$48,595.53
$ 6,300.00
2,641.11
2,012.25
7,966.82
1,250.00
2,700.00
4,729.87
20.00
889.85
3,156.85
3,474.08
700.00
900.00
389.44
$37,130.27
$ 1,586.00
$ 1,388.50
889.85
$ 498.65
$ 4,150.00
3,156.85
$ 993.15
the Treasurer.
203
(F.)
The University Endowment Fund is invested as follows
Book value.
Oregon Kailway and Navigation Co., 4s .
West Shore R. R. Co., 1st Mtg., 4s, 2361 .
City of Cambridge, Sewer Loan, 6s, 1905 .
Norwich and Worcester R. R. Co., 4s, 1927
Rutland R. R., 1st Mtg., 6s, 1902 .
Wilkesbarre and Eastern R. R., 1st Mtg., 5s
1942
Hereford Ry. Co., 4s, 1930
Chicago and Eastern Illinois R. R., 1st Consol
Mtg., 6s, 1934 ....
1st Mtg. Sink. F., 6s, 1907 .
Wayne Co., Michigan, 4s .
Northern Ohio Ry. Co., 1st Mtg., 5s
Lowell, Lawrence, and Haverhill St. Ry., 1st
Mtg., 5s
Worcester and Suburban St. Ry., 1st Mtg., 5s
Worcester and Marlboro St. Ry., 1st Mtg., 5s
Atchison, Topeka and Santa Fe Ry. Co., .
Gen. Mtg., 4s . . . $18,500.00
Adj., 4s .... 10,000.00
Certif. Gen. Mtg., 4s . . 250.00
Second Ave. R. R. Co., New York, 1st Consol
Mtg., 5s, 1948 ....
15 shares Worcester National Bank
71 shares Norwich and Worcester R. R. .
Deposit in Worcester Co. Inst, for Savings
Deposit in Five Cents Savings Bank
100 shares Fitchburg (preferred)
35 shares New York, New Haven, and Hart
ford R. R
100 shares Worcester Traction Co. (preferred)
New England Yarn Co., 5s . . .
Lake Shore Collaterals, 3|-s
Invested in premiums ....
Cash in Worcester National Bank .
$110,000.00
75,000.00
20,000.00
75,000.00
25,000.00
9,800.00
9,350.00
10.000.00
1,000.00
30,000.00
3,000.00
15,000.00
6,000.00
10,000.00
25,000.00
25,000.00
2,250.00
14,603.50
5,000.00
10,000.00
10,300.00
6,982.50
10,700.00
11,000.00
50,000.00
15,230.00
28,920.25
$614,136.25
Market value.
Sept. 1, 1899.
$112,750.00
84,750.00
22,600.00
84,000.00
26,500.00
10,600.00
10,000.00
13,700.00
1,145.00
31,200.00
3,180.00
15,750.00
6,240.00
10,400.00
18,500.00
8,800.00
250.00
30,000.00
2,700.00
15,620.00
5,000.00
10,000.00
11,800.00
7,630.00
10,450.00
11,495.00
50,000.00
28,920.25
$634,480.25
204
Report of
The gross income of the University Endowment
Fund was
$28,407.33
There was paid from this : —
To Sinking Fund to provide for premiums .
To Jonas G. Clark on account of premiums
Accrued interest repaid ....
$700.00
900.00
389.44
Leaving net income carried to University Account
(G.)
The Library Fund is invested as follows : —
50 shares Washington National Bank, Boston
25 shares Tremont National Bank, Boston .
50 shares Merchants' National Bank, Boston
50 shares National Bank of Republic, Boston
50 shares Union National Bank, Boston
50 shares Second National Bank, Boston .
50 shares New England National Bank, Boston
50 shares Atlas National Bank, Boston.
61 shares State National Bank, Boston
15 shares Suffolk National Bank, Boston .
50 shares Eliot National Bank, Boston
50 shares National Bank of Commerce, Boston
50 shares Boylston National Bank, Boston
43 shares Old Boston National Bank, Boston
10 shares City National Bank, Worcester .
15 shares Norwich and Worcester R. R. stock
Northern Ohio R. R. Bonds, 5s .
15 shares New York, New Haven, and Hartford
R. R
Invested in premiums ....
Deposit in Worcester National Bank .
The gross income of the Library Fund was
From dividends and interest
Rebate on bank tax, ......
Balance carried to Library Expense Account
$1,989.44
$26,417.89
Book value.
Market value.
Sept. 1, 1899.
$ 5,527.00
$ 6,000.00
1,766.00
(in liquidation)
7,934.60
8,600.00
7,994.88
8,750.00
6,829.50
7,150.00
9,162.50
8,850.00
8,237.50
7,825.00
6,293.50
5,750.00
6,938.01
7,167.50
1,527.21
1,650.00
6,598.00
7,150.00
5,552.62
5,625.00
6,530.75
5,850.00
4,527.63
5,074.00
1,500.00
1,500.00
3,000.00
3,300.00
4,000.00
4,240.00
2,992.50
3,270.00
150.00
2,273.05
2,273.05
$99,335.25
$100,024.55
$4,085.77
1,172.67
5,258.44
the Treasurer, 205
(H.)
The Library Expense Account : —
Unexpended balance from previous years . . . $3,091.18
Credits for books sold 412.38
Income of the Library Fund for 1899 . . . . 5,258.46 $8,762.02
Tbe expenses, including $900 for administration, heat
and light, were 3,886.46
Leaving a balance Sept. 1, 1899, of . . . $4,875.56
The George S. Barton Fund, deposited in the Worces-
ter Co. Inst, for Savings, amounts to . . $7,239.24
Income during the year 278.43
(J.)
The John White Field Fund, deposited in the Worces-
ter Co. Inst, for Savings, amounts to . . . $653.22
Income during the year 25.74
(K.)
The Clock Fund, deposited in the Five Cents Savings
Bank, amounts to $878.40
Income during the year 33.93
(L.)
The Sinking Fund, to provide for premiums, is de-
posited in the Worcester Five Cents Savings
Bank, and amounts to $2,670.42
(M.)
The salaries of the University Faculty were . . $19,990.00
(N.)
Fellowships and Scholarships $1,310.00
(0.)
Salaries of employees $2,135.00
(P.)
Apparatus and supplies $870.18
Respectfully submitted,
Thomas H. Gage, Treasurer.
206 Report of the Treasurer,
We have examined the books and accounts and securities of Clark
University, and find them to be correct and as stated in the foregoing
treasurer's report for the year ending August 31, 1899.
James P. Hamilton,
T. H. Gage, Jr.,
Auditors.
Id
LECTUKES ON MATHEMATICS.
By Professor Emile Picard.
Premiere Conference.
Sur VExtension de quelques Notions Mathematiques, et en particuUer de
VIdee de Fonction depuis un Siecle.
Mes premiers mots seront pour adresser mes remerciments au Conseil
de cette Universite qui m'a fait I'honneur de m'inviter a ces fetes et m'a
charge de prendre la parole devant quelques mathematiciens americains.
C'est un honneur auquel je suis tres sensible, car nous savons en France
que les etudes mathematiques se developpent rapidement en Amerique
et nous suivons ce moavement avec une tres vive sympathie. Votre
American Journal of Mathematics compte parmi les journaux periodiques
les plus importants et renferme de remarquables memoires, et je lis
toujours pour ma part avec grand profit et interet le Bulletin de la
Societe matbematique americaine, excellente revue historique et critique
qui tient ses lecteurs au courant des travaux les plus recents. J'ai
appris aussi que cette Societe allait fonder un nouveau recueil destine
a des memoires plus etendus ; je ne doute pas qu'il ne soit appele a un
brillant avenir. Dans les trois causeries que nous aliens avoir ensemble,
je ne puis songer a aborder un sujet special qui demanderait une pre-
paration particuliere. Nous allons rester dans les generalites et jeter un
rapide coup d'oeil sur I'extension de quelques notions mathematiques et
en particulier, de I'idee de fonction depuis un siecle.
I.
Toute la science mathematique repose sur I'idee de fonction c'est a
dire de dependance entre deux ou plusieurs grandeurs, dont I'etude con-
stitue le principal objet de I'analyse. II a fallu longtemps avant qu'on
se rendit compte de I'etendue extraordinaire de cette notion ; c'est la
d'ailleurs une circonstance qui a ete tres heureuse pour les progres de la
Science. Si Newton et Leibnitz avaient pense que les fonctions continues
n'ont pas necessairement une derivee, ce qui est le cas general, le calcul
207
208 Emile Picard:
differentiel n'aurait pas pris naissance ; de meme les idees inexactes de
Lagrange sur la possibilite des developpements en series de Taylor ont
rendu d'immenses services. Sans vouloir trop generaliser, on pent dire
que I'erreur est quelquefois utile, et que, dans les epoques vraiment
creatrices, une verite incomplete ou approchee pent etre plus feconde que
la meme verite accompagnee des restrictions necessaires ; I'histoire de la
science confirme plus d'une fois cette remarque et, pour rappeler encore
Newton, il est heureux qu'il ait eu au debut de ses recherches pleine
confiance dans les lois de Kepler. Les geometres du siecle dernier, sans
remonter plus haut, ne raffinaient pas sur I'idee de fonction; pour eux,
une fonction d'une variable est une fonction qu'on pent representer par
une courbe formant un trait continu ; ce sont ces fonctions qu'Euler
appelait functiones continuce. La question de la representation d'une
fonction arbitraire sous une forme analytique dans laquelle interviennent
seulement les operations fondamentales de I'arithmetique effectuees un
nombre fini ou infini de fois, se posa, semble-t-il pour la premiere fois
a propos du probleme des cordes vibrantes. D'Alembert avait donne
I'integrale de I'equation
sous la forme f(x + at^ + (f){x — at'). Daniel Bernoulli montra qu'on
pouvait satisfaire a I'equation differentielle et aux conditions aux limites
par une serie trigonometrique, et il affirma que cette serie donnait la
solution la plus generale. Ce fut I'occasion d'une longue discussion entre
Bernoulli, Euler et Lagrange. Pour ces grands geometres, une fonction
arbitraire etait toujours la fonction arbitraire susceptible d'etre repre-
sentee par un trait continu. En 1807, dans un memoire celebre, et, plus
tard, dans sa theorie analytique de la chaleur, Fourier montra I'extreme
importance des series trigonometriques ; il a, le premier, ose affirmer que
toute fonction pouvait etre representee entre et 2 tt par un developpe-
ment de cette nature, et, ce qui est le point capital, qu'un meme de-
veloppement pouvait entre ces limites representer des fonctions qu'on
considerait comme distinctes, c'est a dire correspondant graphiquement
a des arcs de courbes differentes. II est tres instructif d'etudier dans
la theorie de la chaleur de Fourier les voies diverses que le oelebre geo-
metre a suivies pour avoir les coefficients du developpement. La determi-
nation de ces coefficients a I'aide des integrales classiques ne vient qu'en
Premiere Conference. 209
second lieu ; cette determination avait d'ailleurs ete indiquee auparavant,
quoique d'une maniere incidente, par Euler. Dans une premiere methode,
Fourier obtient les coefficients en envisageant une infinite d'equations du
premier degre a une infinite d'inconnues ; c'etait une recherche audacieuse
pour I'epoque, et nous ne devons pas nous attendre a trouver dans cette
etude toute la rigueur que nous exigeons aujourd'hui. II n'en faut pas
moins se souvenir que Fourier eut le premier la hardiesse de resoudre des
systemes d'une infinite d'equations lineaires a une infinite d'inconnues.
II y a d'ailleurs en analyse plus d'une question ou se presentent de tels
systemes. C'est le cas quand on veut chercher le developpement du quo-
tient de deux series trigonometriques, et aussi, quand ayant a integrer
une equation differentielle lineaire a coefficients periodiques, on veut y
satisfaire par une fonction periodique ou au moyen du produit d'une telle
fonction par une exponentielle ; ce dernier cas se presente dans plusieurs
problemes de mecanique celeste et en particulier dans les beaux travaux
de M. Hill sur le mouvement du perigee de la lune. M. Poincare a pose
les principes d'une etude rigoureuse des systemes d'equations en nombre
infini, specialement dans le cas des systemes homogenes. II introduit
dans cette theorie les determinants d'ordre infini, et un fait inattendu
ressort de ses recherches, a savoir que des egalites en nombre infini
peuvent dans certains cas etre remplacees par une infinite d'inegalites.
II y a d'ailleurs en analyse bien d'autres questions ou on se trouve en
presence d'une infinite d'equations et il y aura un jour un chapitre interes-
sant a ecrire sur I'integration d'un nombre infini d'equations differentielles
avec une infinite de fonctions inconnues. Mais revenons aux series trigo-
nometriques. En poursuivant rapidement leur histoire, nous arrivons a
la periode ou Cauchy, Abel, et Dirichlet soumettent a une revision severe
les principes fondamentaux de I'analyse mathematique. Le memoire de
Dirichlet sur les series de Fourier est reste un modele de rigueur ;
I'illustre auteur precise les conditions pour que Ton puisse affirmer qu'un
developpement trigonometrique avec les coefficients de Fourier represente
une fonction donnee dans I'intervalle de a 2 tt, et ces conditions sont
restees dans la science sous le nom de conditions de Dirichlet. Elles sont
seulement suffisantes, mais on ne pent esperer dans cette theorie trouver,
sous une forme pratique, des conditions a la fois necessaires et suffisantes.
II est certain aujourd'hui, grace surtout aux travaux de Du Bois-Reymond,
qu'une fonction continue n'est pas necessairement toujours developpable
en serie trigonometrique; la condition suffisante de M. Lipschitz formulee
210 Emile Picard :
par I'inegalite [/(a; + A) — /(a;)] < ^A"(a > 0), en designant par Tc une
constante fixe, a un grand caractere de generalite, et il en est de meme
du theoreme de M. Camille Jordan sur la legitimite du developpement
pour les fonctions a variation bornee.
Le memoire de Riemann sur les series trigonometriques est celebre
dans I'histoire de ces series ; on pent dire en deux mots, pour le carac-
teriser, qu'il abandonne le point de vue de Dirichlet, et qu'au lieu de
chercher des conditions suffisantes, sa principale preoccupation est de
trouver des conditions necessaires. A un autre point de vue encore, le
memoire de Riemann marque une date parce qu'il continue cette revision
des principes du calcul infinitesimal commencee par Abel et Cauchy ; la
distinction entre les fonctions integrables et les fonctions non integrables
y apparait pour la premiere fois, et on pent dire qu'il resulte des travaux
de Riemann qu'il y a des fonctions continues n'ayant pas de derivees.
On doit a M. G. Cantor la reponse a une question importante : une
fonction peut-elle etre representee entre et 2 tt de plusieurs manieres
par une serie trigonometrique ? En d'autres termes, zero peut-il etre
represente par un developpement trigonometrique ou les coefficients ne
soient pas tous nuls ? Independamment du resultat lui-meme, le memoire
de M. Cantor est digne d'interet parce que, dans une question depuis
longtemps posee, des notions concernant les ensembles de points viennent
jouer un role utile. Etant donne un ensemble de points entre et 2 tt,
M. Cantor appelle ensemble derive I'ensemble de ses points limites, et
on pent definir ainsi de proclie en proche les derivees successives d'un
ensemble. Si la derivee n^™* d'un ensemble se reduit a un nombre
limite de points, I'ensemble sera dit de la w*'"* espece. M. Cantor etablit
que si dans I'intervale (0, 2 tt) une serie trigonometrique est nulle pour
toutes les valeurs de a; a I'exception de celles qui correspondent aux
points d'un ensemble d'espece n, pour lequel on ne salt rien de la serie
tous les coefficients seront nuls.
II.
J'ai insiste, peut-etre un peu longuement, sur les series trigono
metriques. Independamment de leur importance dans les applications
et particulierement en physique mathematique, elles ont joue un role
considerable dans revolution de la notion de fonction ; c'est leur etude
qui a appele I'attention sur des circonstances, qui ne nous etonnent plus
aujourd'hui, mais qui paraissaient jadis invraisemblables, comma, par
Premiere Conference. 211
exemple, ce fait que la limite vers laquelle tend una serie de fonctions
continues pent n'etre pas egale a la valeur de la serie en ce point. Les
precautions a prendre dans la derivation des series ont ete aussi sug-
gerees par les series trigonometriques ; on pent faire remonter a cet
exemple les nombreuses recherches effectuees depuis Cauchy sur la deri-
vation et rintegration des series, auxquelles M. Osgood ajoutait il y
a quelques annees un important complement dans son memoire sur la
convergence non-uniforme.
Le developpement d'une fonction en serie trigonometrique est aussi
le type le plus simple de developpements tres generaux qui se presen-
tent dans les applications ; Fourier, ici encore, a ete un precurseur.
L'etude du refroidissement d'une sphere, en supposant que la tempera-
ture ne depende que du temps et de la distance au centre, I'a conduit
a un developpement ou, au lieu des lignes trigonometriques des multiples
x^ 2 a:, •••, nx de la variable, figurent les lignes trigonometriques de a^a;,
a^, •••, a^p:^ les a designant les racines en nombre infini d'une certaine
equation transcendante, et il a esquisse une theorie de ces sortes de
developpements. Cette etude a et^ reprise par Cauchy dans plusieurs
memoires qui forment une des applications les plus remarquables de ce
que le grand analyste appelait le calcul des residus. Sous des conditions
tres generales relatives a I'equation transcendante, Cauchy a demontre
en toute rigueur la legitimite des developpements pour une fonction
satisfaisant d'ailleurs aux conditions de Dirichlet, et ainsi se sont trouves
considerablement generalises les resultats du memoire classique de I'il-
lustre geometre allemand.
D'autres developpements d'un caractere encore plus general se ren-
contrent en physique mathematique, et ont fait I'objet des travaux de
Poisson, de Sturm et de Liouville et de bien d'autres, mais ici se pre-
sentent, au point de vue de la rigueur complete, des difficultes que I'on
a reussi a surmonter que dans un petit nombre de cas. Je citerai seule-
ment I'exemple tres simple du refroidissement d'un mur indefini dont
les faces extremes sont maintenues a la temperature zero ; on suppose
d'ailleurs que la chaleur specifique soit une fonction de I'abscisse x cor-
respondant a chaque tranche, de telle sorte que Ton a pour la tempera-
ture V I'equation aux derivees partielles
Tl = ^^^)'^'
212 Emile Picard :
ou A(x) est une fonction continue et positive de x dans I'intervalle (a, V)
de I'epaisseur du mur. Envisageons I'equation lineaire ordinaire
et les valeurs positives de k en nombre infini, ^j, k^^ •••, ^„ •••, pour les-
quelles il existe une integrale de I'equation precedente s'annulant en
a et 5. A chaque valeur de k^ correspond une integrale yi(x) de cette
equation (determinee a une constante pres), et le probleme qui se pre-
sente est de developper une fonction f(x) s'annulant en a et J sous la
forme
La demonstration rigoureuse de ce developpement resulte des der-
nieres recherches de M. Stekloff, s'aidant des travaux anterieurs de M.
Poincare sur les equations de la physique matliematique. II semble bien
qu'il soit indispensable pour I'entiere rigueur de supposer que /(a;) a des
derivees des deux premiers ordres ; nous sommes loin d'atteindre ici a la
generalite des conditions de Dirichlet pour le developpement en serie
trigonometrique qui rentre d'ailleurs comme cas particulier (celui ou
A(x) est une constante) dans le cas precedent.
III.
L'histoire des developpements en series que je viens de retracer rapide-
ment nous donne un remarquable exemple de I'intime solidarite qui unit
a certains moments I'analyse pure et les mathematiques appliquees. En
plus d'une occasion, ce sont celles-ci qui out donne I'impulsion en posant
les problemes, et c'est un fait assurement remarquable que des questions
concernant les cordes vibrantes ou la propagation de la chaleur aient
conduit les geometres a approfondir la notion si complexe de fonction.
L'histoire de la science matliematique offrirait d'ailleurs des le debut
des exemples analogues ; nos facultes d'abstraction ne trouvent primi-
tivement a s'exercer qu'en partant de certains faits concrets, et c'est sans
doute en reflechissant aux procedes empiriques des praticiens egyptiens
leurs predecesseurs que les premiers geometres grecs creerent la science
geometrique. Mais ces vues risqueraient de m'entrainer trop loin, Je
tiens seulement a aj outer qu'il ne faudrait pas professer une opinion trop
systematique sur cette marche parallele de la theorie pure et des applica-
tions, comme le faisait avec Laplace, Fourier, Poisson la brillante ecole
Premiere Conference. 213
frangaise de physique mathematique du commencement de ce siecle.
Pour eux, I'analyse pure n'etait que I'instrument, et Fourier, en annon-
gant a 1' Academic des sciences, les travaux de Jacobi, disait que les ques-
tions de la philosophic naturelle doivent etre le principal objet des
meditations des geometres. " On doit desirer, ajoutait-il, que les personnes
les plus propres a perfectionner la science du calcul dirigent leurs tra-
vaux vers ces hautes applications si necessaires au progres de I'intelli-
gence humaine." Ce desir tres legitime ne doit pas etre exclusif ; ce
serait meconnaitre d'abord la valeur philosophique et artistique des
mathematiques ; de plus des speculations theoriques sont restees pendant
longtemps eloignees de toute application, quand un moment est venu ou
elles ont pu etre utilisees. On n'en peut pas citer d'exemple plus
memorable que le concept des sections coniques elabore par les geometres
grecs, qui resta inutilise pendant deux mille ans, jusqu'au jour ou Kepler
s'en servit dans I'etude de la planete Mars. Les questions s'epuisent
pour un temps, et il n'est pas bon que tous les chercheurs marchent dans
la meme voie. Peu d'annees apres que Fourier ecrivait les lignes que
je viens de rappeler, apparaissait Evariste Galois qui aurait, s'il avait
vecu davantage, retabli I'equilibre en ramenant les recherches vers les
regions les plus elevees de la theorie pure, et ce fut un malheur irre-
parable pour la science frangaise que la mort de Galois, dont le genie
allait exercer une action si profonde sur les parties les plus varices des
mathematiques.
Avec cette digression, nous semblons etre bien loin, messieurs, de notre
promenade a travers I'idee de fonction depuis le commencement de ce
siecle. Elle n'etait cependant pas inutile, pour montrer qu'un moment
devait arriver ou les speculations sur la theorie des f onctions de variables
reelles se poursuivraient sans souci immediat des applications et pren-
draient de plus en plus un caractere philosophique. Nous avons deja dit
qu'il resultait indirectement des travaux de Riemann qu'une fonction con-
tinue n'a pas necessairement une derivee. Weierstrass donna le premier
exemple d'une fonction continue n'ayant de derivee pour aucune valeur
de la variable, et il fit connaitre au sujet des fonctions continues une
proposition qui nous ramene aux developpements en series, mais ici les
termes sont des polynomes. D'apres Weierstrass, toute fonction con-
tinue dans un intervalle peut etre developpee en une serie de polynomes
qui est absolument et uniformement convergente dans cet intervalle.
La demonstration de I'illustre geometre est tres compliquee ; elle prend
214 Emile Picard :
comme point de depart une integrale consideree par Fourier dans la
theorie de la chaleur, qui permet d'obtenir la fonction consideree comme
la limite d'une fonction transcendante entiere dependant d'un parametre,
quand celui-ci tend vers zero. C'est de la que Weierstrass deduit la
possibilite de representer d'une maniere approchee par un polynome
toute fonction continue dans un intervalle fini, d'ou se tire alors de suite
le resultat enonce. On pent arriver beaucoup plus rapidement au
theoreme de Weierstrass en partant de I'integrale classique de Poisson
dans la theorie des series trigonometriques ; elle montre facilement que
la fonction, supposee definie dans un intervalle moindre que 2 tt, peut-etre
representee avec telle approximation que Ton voudra par une serie
limitee de Fourier, et on passe de suite a une representation approchee
par un polynome ; celle demonstration s'etend a des fonctions continues
d'un nombre quelconque de variables. M. Volterra est arrive aussi tres
simplement au theoreme qui nous occupe en remarquant qu'une fonction
continue est representable avec telle approximation qu'on voudra par
une ligne polygonale convenable ; celle-ci conduit a une serie de Fourier
uniformement convergente, et en la reduisaut a un nombre suffisamment
grand mais limite de termes on retombe sur le resultat indique plus
haut. Le theoreme de Weierstrass presente un reel interet philosophique,
en meme temps qu'il pent avoir quelque utilite au point de vue du cal-
cul pratique ; on en a aussi quelquefois fait usage pour la demonstration
de certaines propositions.
Les developpements en series de polynomes speciaux sont d'un grand
interet, mais ils ne peuvent s'appliquer qu'a des fonctions satisfaisant
a des conditions particulieres. Ainsi, dans son memoire sur I'ap-
proximation des fonctions de tres grands nombres, M. Darboux a
etudie les developpements d'une fonction suivant les polynomes de Jacobi
provenant de la serie hypergeometrique. Les conditions sont encore
celles de Dirichlet ; pareillement aussi dans le cas ou la fonction devient
infinie, elle doit rester integrable. H y a cependent une difference quand
la fonction devient infinie pour les points extremes. Dans le cas des
polynomes de Legendre, une fonction qui deviendrait infinie d'un ordre
egal ou superieur a -I pour x — ±\ ne serait pas developpable, quoique
les coefficients aient un sens.
IV.
Si nous revenons aux fonctions prises dans toute leur generalite, on
reconnait vite la necessite d'etablir avec un soin extreme certaines pro-
Premiere Conference. 215
positions que Ton accorde aisement pour les fonctions usuelles. C'est ce
qu'avait deja reconnu Cauchy dans son Analyse algebrique ; les travaux
de Hankel, le memoire de M. Darboux sur les fonctions discontinues, le
beau livre de M. Dini et les etudes plus recentes des geometres italiens
montrent bien les precautions necessaires dans ce genre de recherches.
Ainsi, une fonction de deux variables reelles pent etre continue par rap-
port a a: et par rapport a y sans etre continue par rapport a I'ensemble
des deux variables, comme M. Dini en a indique des exemples. Parmi
les travaux les plus recents sur ces questions delicates, je m'arreterai un
instant sur un memoire de M. Baire qui renferme de curieux resultats.
L'auteur a reussi a trouver la condition necessaire et suffisante pour qu'une
fonction fQc) d'une variable reelle puisse etre representee par une serie
simple de polynomes; I'enonce suppose certaines notions sur la discon-
tinuite d'une fonction par rapport a un ensemble de points : une fonction
pent etre ponctuellement ou totalement discontinue par rapport a cet
ensemble. La condition obtenne est que la fonction soit ponctuellement
discontinue par rapport a tout ensemble parfait. M. Baire se pose aussi
une question singuliere sur les equations lineaires aux derivees partielles.
Envisageons I'equation
Si je vous demandais quelles sont les fonctions satisfaisant a cette
equation, vous me repondriez sans doute que les fonctions de a; — y
repondent seules a la question. M. Baire n'en est pas absolument sur ;
il remarque que la theorie du changement de variables suppose la con-
tinuite des derivees qu'on emploie ; si on suppose seulement I'existence
des derivees -^L et -^ de la fonction cherchee /, on ne pent pas faire le
dx dy
changement de variables classique. II faut une analyse delicate pour
etablir que la fonction /, supposee continue par rapport a I'ensemble des
variables x et y, et satisfaisant a (1) est une fonction diQ x — y; la conclu-
sion reste douteuse si / est seulement continue par rapport a a; et par
rapport a y.
Au point de vue geometrique les recherches generales sur les fonctions
ne sont pas non plus sans interet ; elles nous apprennent a nous defier de
nos conceptions les plus simples. Quoi de plus simple semble-t-il qu'une
courbe dont les coordonnees x ety sont des fonctions continues d'un para-
metre t variant entre a et b. M. Peano a cependant montre qu'on pent
216 Emile Picard :
choisir ces deux fonctions de telle sorte que, quand t varie entre a et 5, le
point (a;, 3/) puisse prendre une position quelconque dans un rectangle.
A certains points (a;, y) pourront correspondre d'ailleurs, dans I'exemple
de M. Peano, deux ou quatre valeurs de t. Ce resultat est au premier
abord deconcertant ; il derange nos idees sur les surfaces et sur les
courbes. Voici encore un resultat singulier obtenu tout recemment par
M. Lebegue ; il y a d'autres surfaces que les surfaces developpables qui
sont applicables sur un plan. On pent a Taide de fonctions continues
obtenir des surfaces correspondant a un plan de telle sorte que toute ligne
rectifiable du plan ait pour correspondante une ligne rectifiable de la
surface, et la surface n'est cependant pas reglee.
De tels exemples montrent la subtilite des recherches auxquelles
doivent se livrer aujourd'hui ceux qui veulent approfondir la notion de
fonction prise dans son extreme generalite. Ces etudes sont en bien des
points intimement liees aux speculations sur la notion meme de nombre.
Nous rejoignons ici une ecole de philosophic mathematique qui s'est
brillamment developpee depuis quelque trente ans, ecole qui se livre a
une minutieuse analyse sur la nature du nombre. On ne pent s'empecher
d'etre frappe du nombre considerable de publications parues dans ces
dernieres annees et se rapportant a cette mathematique philosophique ;
elles sont bien en accord avec les tendances generales de I'epoque ou nous
vivons, et ou I'esprit humain applique dans des directions varices une
critique de plus en plus penetrante. Ces speculations raffinees ont meme
penetre dans I'enseignement elementaire, ce qui est a mon avis tres
regrettable. Mais il ne s'agit pas ici d'enseignement ; je ne recherche
pas non plus I'interet que ces etudes presentent pour le philosophe ; il me
parait tres reel, et on doit souhaiter que de jeunes philosophes s'engagent
dans cette direction apres s'etre inities serieusement aux mathematiques.
Je ne veux me placer qu'au point de vue de la mathematique. De bons
esprits contestent que les speculations dont je parle aient quelque impor-
tance pour les mathematiques positives et ils craignent de voir beaucoup
de talent depense dans des recherches steriles. Je comprends tres bien
leurs craintes mais je ne partage pas entierement leur avis. II y a lieu
sans doute de faire des distinctions. Certaines questions sont d'un interet
purement philosophique et n'auront jamais vraisemblablement la moindre
utilite pour les mathematiques, comme, par exemple, de savoir si la priorite
appartient au nombre cardinal ou au nombre ordinal, c'est a dire si I'idee
de nombre proprement dit est anterieur a cells de rang ou si c'est
Premiere Conference. 217
I'inverse. Mais dans d'autres cas, il n'en est plus de meme ; ainsi il est
vraisemblable que la theorie des ensembles de M. Cantor, que nous avons
deja rencontree deux fois sur notre chemin, est a la veille de jouer un
role utile dans des problemes qui n'ont pas ete poses expres pour etre une
application de la theorie. Ne regrettons done pas cet effort* hardi sur
I'idee de nombre et sur celle de fonction, car la theorie des fonctions de
variables reelles est la veritable base de I'analyse mathematique.
II faut bien, il est vrai, reconnaitre que la notion generale de fonction
est tres vague, et nous ne pouvons obtenir des resultats de quelque
etendue qu'en faisant des hypotheses particulieres. Qu'est ce qui a guide
plus ou moins consciemment dans le choix de ces hypotheses ? II results
de ce que nous avons dit sur les rapports entre I'analyse et les applica-
tions aux phenomenes naturels, que celles-ci ont plus d'une fois guide le
mathematicien dans son choix. Une hypothese essentielle a ete celle de
la continuite. Suivant le vieil adage "natura non facit saltus" nous
avons le sentiment, on pourrait dire la croyance, que dans la nature il n'y
a pas de place pour la discontinuite. II est utile quelquefois de conserver
le discontinu dans nos calculs, par exemple quand nous regardons comme
nulle la duree du choc en mecanique rationnelle, ou quand nous reduisons
a une surface les couches de passage dans plusieurs questions de physique;
mais nous savons que, pour si petite qu'elle soit, les chocs ont une certaine
duree et les physiciens nous ont appris a mesurer I'epaisseur des couches
ou se produisent dans plusieurs phenomenes des variations tres rapides.
L'idee de derivee s'impose deja moins ; elle repond cependant au senti-
ment confus de la rapidite plus ou moins grande avec laquelle s'accomplit
tel ou tel phenomene. L'hypothese relative a la possibilite de la deriva-
tion d'une fonction a done une origine analogue a celle de la continuite.
Je ne veux pas dire qu'au point de vue du nombre l'idee de continuite soit
aussi claire au fond qu'elle en a Pair, mais il ne s'agit ici que de la notion
du continu physique tiree des donnees brutes des sens.
Dans d'autres cas, on ne voit pas de cause du meme ordre dans la
particularite imposee a la fonction ; il en est ainsi, ce me semble, pour la
propriete des fonctions dites analytiques c'est a dire des fonctions qui
dans le voisinage d'une valeur arbitraire de la variable peuvent etre
developpees en series de Taylor. Les fonctions etudiees les premieres,
comme les fonctions rationnelles, I'exponentielle, les lignes trigonome-
218 Emile Picard :
triques, jouissant de cette propriete, rattention se sera sans doute trouvee
appelee sur elle; et ensuite la facilite avec laquelle cette hypothese a
permis d'aborder certaines questions a fait acquerir aux fonctions analy-
tiques une importance considerable. C'est done a leur commodite dans
nos calculs qu'elles doivent le grand role qu'elles jouent.
On ne sait pas d'ailleurs, pour une fonction definie seulement pour les
valeurs reelles de la variable, quelles sont les conditions de legitimite du
developpement en serie de Taylor. Une fonction de x pent avoir des
derivees de tout ordre pour toute valeur de la variable, et n'etre cependant
pas developpable. On doit a M. Borel un resultat remarquable con-
cernant les fonctions d'une variable reelle definie dans un certain inter-
valle et ayant dans cet intervalle des derivees de tout ordre. Si Tintervalle
est (— TT, +7r), la fonction peut etre representee par un developpement
de la forme
I
n=0
(A^x" + Bn cos nx + O^ sin nx").
Ces diverses remarques m'amenent a dire un mot d'une ecole de geo-
metres qui ne veulent rien voir en dehors des fonctions analytiques, et
d'une maniere plus generale de I'importance, peut-etre exageree, qu'a prise
dans les travaux modernes la theorie des fonctions analytiques. C'est
mutiler singulierement I'analyse que de vouloir se borner a des deve-
loppements aussi particuliers que les series entieres, alors que Ton peut
former tant de developpements d'une autre nature qui ne peuvent jamais
etre representees par de telles series. Sans doute, les fonctions les plus
usuelles sont analytiques, et on pourrait nous demander de citer des
exemples dans la solution desquels interviennent des fonctions non analy-
tiques, tandis que les donnees sont analytiques. lis ne sont pas courants ;
ce sont les equations aux derivees partielles qui probablement les four-
niront le plus facilement. Le suivant, du a M. Borel, me parait digne
d'etre signale. Envisageons I'equation
ou a est une irrationnelle convenablement choisie, et f(x, y^ une certains
fonction analytique de a; et y de periode 2 ir pour x et y. Pour I'equation
de cette forme citee par M. Borel, il y a une seule solution periodique et
cette solution n'est pas analytique. Soit a un nombre incommensurable
Premiere Conference. 219
tel que — etant I'une quelconque des reduites du developpement de a en
fraction continue, on ait
on forme
^ (2:, ^) = 2 a'^i'b'^i cos (m^x) cos (yi?y') (a < 1, 5 < 1).
C'est une fonction non analytique. Posons d'autre part
^-a*g = t(..), (1)
la fonction i/r sera analytique. Done si on prend I'equation (1) a priori
et qu'on cherche une solution periodique, en x et y, il n'y en a qu'une ;
c'est <^ qui n'est pas analytique.
C'est encore, en se plagant a un autre point de vue, qu'il parait
mauvais de reduire la theorie des fonctions a la theorie des fonctions
analytiques. II y a de nombreuses questions, ou le fait pour les donnees
d'etre analytiques ne donne aucune facilite pour la solution, et ou on
risque, en portant trop son attention sur cette nature des donnees, de
chercher la solution dans des voies sans issues. Pour le probleme du
refroidissement de la barre dont je parlais plus haut, qu'importe que les
fonctions donnees A(x) et f(x) soient ou non analytiques ? Ce n'est pas
tout ; il y a un dernier point sur lequel je tiens a insister. II pent ar river
que la circonstance d'avoir a faire a des fonctions analytiques conduise a
une solution, mais il se pent que celle-ci ne se presente pas sous la forme
la plus favorable, forme a laquelle on arrive au contraire en faisant ab-
straction de la nature analytique des donnees. La theorie des equations
differentielles fournirait des exemples a I'appui de cette assertion; bornons
nous a citer le theoreme fondamental du Calcul Integral relatif a I'ex-
istence de I'integrale de I'equation differentielle -^=f(x^y). Ce sont
dx
les demonstrations ne supposant pas que la fonction / soit analytique,
qui donnent le plus grand intervalle comme region ou I'integrale est
certainement determinee ; I'analyste, qui suppose analytique la fonction
reelle f(x, y) et veut n'envisager que des series entieres, est conduit par
son mode de demonstration a un domaine plus restreint.
J'ai simplemeut eu pour but dans ce qui precede de montrer qu'il ne
faut pas restreindre systematiquement la notion de fonction. D'une
maniere generale, admirons des systemes tres bien ordonnes, mais mefions
nous un pen de leur apparence scolastique, qui risque d'etouffer I'esprit
220 Emile Picard:
d'invention. II ne s'agit pas, bien entendu, de nier la grande importance
actuelle de la tlieorie des fonctions analytiques, mais il ne faut pas oublier
qu'elles ne forment qu'une classe tres particuliere de fonctions, et on doit
souhaiter qu'un jour vienne ou les mathematiciens elaborent des theories
de plus en plus comprehensives ; c'est ce qui arrivera peut-etre au siecle
prochain, si I'idee de fonction, dont je vous ai bien incompletement
esquisse I'histoire, continue son evolution. Mais, pour le moment nous
sommes encore au dix-neuvieme siecle ; j'aurai I'occasion demain et apres
demain de faire amende honorable aux fonctions analytiques, qui depuis
trente ans ont fait, comme vous savez, I'objet de travaux considerables.
VI.
Nous venons de voir les vastes perspectives qu'ouvre I'extension de
plus en plus grande de la notion de fonction. II faudra certainement
montrer dans cette voie beaucoup de prudence, et ne pas entreprendre
avant I'heure des recherches qui resteraient steriles ; mais il n'est pas
douteux qu'un jour viendra ou I'analyste sentira le besoin d'etendre le
domaine de ses recherches. L'extension de I'idee de fonction n'est pas la
seule qu'aient poursuivie en ce siecle les mathematiciens qui s'interessent
aux principes de la science ; la question des quantites complexes a vive-
ment excite I'interet, d'autant plus qu'une certaine obscurite planait sur
elle, qu'entrainait le mot un peu mysterieux de quantites imaginaires.
Le sujet ne presente plus rien aujourd'hui de mysterieux. Dans un
memoire public en 1884 Weierstrass a developpe une theorie des nombres
complexes. II suppose que I'on considere des nombres de la forme
OU les X sont des nombres reels on imaginaires ordinaires. Les e sont de
purs symboles. On fait Thypothese que la somme, la difference, le pro-
duit et le quotient de deux nombres de I'ensemble font eux-memes partie
de cet ensemble. Les produits e.pe^ (^p, q = 1, 2, •••, ?i) sont done des
expressions Up^g lineaires et homogenes en e^, e^^, •••, e„ qui jouent le role
essentiel dans la theorie. Weierstrass suppose de plus que les theoremes
dits commutatif et assoeiatif subsistent tant pour I'addition que pour la
mul'Liplication. Pour I'addition, ils sont verifies d'eux-memes ; pour la
multiplication, ils s'expriment par les egalites
ah = 6a, (ah) . c = a • (he).
Premiere Conference. 221
a, 5, c etant trois nombres quelconques de I'ensemble. Ces conditions
conduisent a certaines relations entre les coefficients des formes lineaires
I^p^q. A tout systeme de formes E^^^ verifiant ces conditions corre-
spondra un ensemble de nombres complexes. Les nombres complexes
que nous venons de definir different seulement en un point des nombres
complexes ordinaires. Quand n est superieur a deux, il pent exister des
nombres differents de zero dont le produit par certains autres nombres
est nul. Weierstrass appelle ces nombres des diviseurs de zero. M.
Dedekind a montre qu'en general les calculs avec ces nombres complexes
se ramenaient aux calculs de I'algebre ordinaire ; d'une maniere plus
precise, si le carre d'un nombre ne pent etre nul sans que ce nombre soit
nul, on pent aux n unites complexes primitives substituer n autres unites
(le determinant de la substitution n'etant pas nul) de telle sorte que pour
ces nouvelles unites e\^ e'^, •■•, e'„, on ait
d'ou Ton conclut que les calculs relatifs aux nombres complexes prece-
dents se ramenent a des calculs relatifs aux nombres reels ou complexes
ordinaires.
Nous avons admis que les lois commutative et associative subsis-
taient dans I'algebre precedente. On s'est place a un point de vue plus
general en supposant que, seule, la loi associative subsistait [c'est a dire
(ah)c = a(hc)']. On a alors une algebre beaucoup plus generale ; celle-ci
est completement determinee par le systeme des expressions lineaires
Ep^q. Un exemple celebre d'un systeme a quatre unites e^, e^^ e^, e^ est
fourni par les quaternions d' Hamilton
gj = ±, 62^^*5 ^3 ^ ^' ^4 ^^ '
avec les relations t^ = p = k^ z= —1
ij = - ji = k
jk = — kj = i
ki = — ik = j.
Une remarque tres interessante de M. Poincare ramene toute la
theorie des quantites complexes a une question concernant la theorie des
groupes. Elle consiste en ce qu'a chaque systeme d'unites complexes
correspond un groupe continu (au sens de Lie) de substitutions lineaires
222 Emile Picard :
a n variables, dont les coefficients sont des fonctions lineaires de n para-
metres arbitraires, et inversement. Cette idee a ete approfondie par
M. Scheffers qui a ete ainsi conduit a partager les nombres complexes
en deux classes, suivant que le groupe qui leur correspond est integrable
ou non integrable. A cette derniere classe appartient le groupe corres-
pondant aux quaternions, et ceux-ci sont les representants les plus simples
de cette categoric de nombres complexes. Le rapprochement entre la
theorie des groupes de Lie et les nombres complexes fait disparaitre
le mystere qui semblait planer sur ceux-ci, et la veritable origine des
symboles est ainsi bien mise en evidence. On pent se demander si ce
symbolisme est susceptible d'accroitre la puissance de I'Analyse. En
France, les geometres qui s'interessent a ces calculs sont tres peu nom-
breux ; je sais qu'au contraire en Angleterre et, je crois aussi, dans ce
pays les quaternions sont tres apprecies. Je ne les ai pas assez manies
moi-meme, pour me rendre compte si leur emploi en mecanique ou en
physique mathematique simplifie les calculs d'une maniere tres appre-
ciable ; il y a probablement la surtout une affaire d'habitude. Le point
vraiment interessant serait de savoir si ces quantites complexes presen-
teront un jour quelque interet pour I'analyse generale, comme il arrive
pour les imaginaires ordinaires. Les essais tentes jusqu'ici dans cette voie
ne paraissent pas avoir ete heureux ; mais, maintenant que le lien avec
la theorie des groupes est completement mis en evidence, il n'est pas
impossible que de nouvelles tentatives n'aboutissent a quelque resultat
interessant.
Les idees de nombres reel ou complexe, la notion de fonction sont
a la base meme de I'analyse ; il y a encore une autre notion que le travail
mathematique de ce siecle a conduit a elargir considerablement. L'idee
d'espace forme la matiere meme de la geometric ; elle aussi a ete sou-
mise a une critique penetrante qui a renouvele les bases de la geometric.
Je n'en referai pas I'histoire depuis Gauss, Bolyai et Lobatschevski, his-
toire tres souvent racontee, ni ne prendrai parti dans les querelles que
se font encore a ce sujet les philosophes. Je veux dire seulement un
mot de I'interet qu'ont eu pour les mathematiques les speculations sur
la nature de I'espace. Dans le memoire cel^bre de Riemann, apparaissent
pour la premiere fois les notions relatives a la courbure de I'espace dans
les differentes directions, c'est-a-dire les — ^^ — ^ — - fonctions invariantes
caracteristiques d'une multiplicite a n dimensions ; une vive impulsion
Preiniere Conference. 223
a ete ainsi donnee a la theorie des formes quadratiques de differentielles.
Pour ne citer qu'un exemple, j'indiquerai seulement la forme
dx^ + dy^
qui donne le carre de Felement d'arc dans la geometric de Lobatchevski ;
et il est interessant de rappeler le role qu'elle a joue dans les recherches
de M. Poincare sur la formation des groupes fuchsiens. Apres Rie-
mann, Helmholtz posa la question sur un autre terrain: son idee fonda-
mentale consiste a porter I'attention sur I'ensemble des mouvements
possibles dans I'espace dont on fait I'etude. Le grand physicien traitait
ainsi par avance de problemes se rattacbant a la tbeorie des groupes.
Celle-ci n'etait pas encore creee a I'epoque ou Helmboltz ecrivait son
memoire ; il a commis quelques erreurs apres tout secondaires, mais
il n'en a pas moins la gloire d'avoir le premier regarde une geometric
comme I'etude d'un groupe. Les recherches d'Helmholtz furent reprises
completement par Lie ; elles lui offraient une magnifique occasion d'ap-
pliquer son admirable theorie des groupes de transformations. Dans
ces etudes, I'espace est a priori regarde comme une multiplicite, et, en
prenant le cas de trois dimensions, un point est defini par trois quantites
(r», ?/, z). Un mouvement dans I'espace n'est autre chose qu'une trans-
formation
x^ =f(x, y, z), y^ = <^(x, y, 2), z' = -^(x, y, 2)
valable pour une portion de I'espace. On suppose que tous les mouve-
ments possibles forment un groupe a six parametres, qu'ils laissent
invariable une fonction des coordonnes de deux points quelconques,
qu'enfin le mouvement libre soit possible, comme disait Helmholtz. Lie
demontre alors que I'espace euclidien et les espaces non euclidiens sont
les seuls qui satisfassent a ces conditions. Au point de vue ou s'est place
Lie, I'etude des principes de la geometric pent etrc regardee comme
epuisee, mais il se borne a considerer une petite portion de Tespacc.
Clifford et Klein ont appele I'attention sur la question de la connexite de
I'espace qui est extremement interessante ; nous nc savons rien sur la
connexite de I'espace ou nous vivons. On pent aussi chercher a appro-
fondir le postulat de I'espace regarde comme une multiplicite, et sub-
ordonner la conception metrique dc I'espace a la conception projective
avec von Staudt, Cayley et Klein ; mais je dois me contenter de rappeler
ces directions diverses.
224 Emile Picard :
J'ai seulement, messieurs, voulu montrer dans cette conference quelles
perspectives ouvre aux chercheurs I'extension de nos idees sur les fonc-
tions, sur le nombre et sur I'espace. Si I'elaboration mathematique est
aussi feconde au siecle prochain qu'elle Fa ete en ce siecle, I'analyse
differera beaucoup dans cent ans de ce qu'elle est aujourd'hui ; on
maniera peut-etre couramment les fonctions les plus extraordinaires, et
on verra tres clair dans des espaces ayant beaucoup de dimensions et des
connexites elevees. Pour se representer I'etat de la mathematique en
Fan 2000, il faudrait I'imagination de I'auteur de "Looking Backward";
il est mallieureux que M. Bellamy dans son roman ne nous ait pas parle
des mathematiques a cette epoque. Comme I'humanite, s'il faut Ten
croire, aura alors beaucoup de loisirs, les mathematiques seront sans
doute extremement florissantes et les problemes qui nous arretent aujour-
d'hui ne seront plus que des jeux d'enfants pour nos successeurs.
Secondb Conference.
Quelques Vues GenSrales sur la Theorie des Equations DiffSrentielles.
Je voudrais aujourd'hui jeter un coup d'oeil sur la theorie des equa-
tions differentielles, qui joue en analyse un role considerable et dont les
progres importent vivement a ses applications; c'est un domaine tres
vaste et j'eprouve quelque embarras a faire un choix entre les directions
si diverses ou s'est developpee cette theorie. Les geometres du siecle
dernier ne paraissent pas s'etre preoccupes d'etablir rigoureusement
I'existence des integrales des equations differentielles; ils integraient,
quand ils le pouvaient, les equations qui se presentaient dans leurs
recherches, sans se soucier de ces theorem es d'existence, comme on dit
aujourd'hui, auxquels nous attachons beaucoup d'importance. C'est a
Cauchy que Ton doit les premieres recherches precises sur ces questions ;
le champ en est tres vaste, et il ne I'a pas parcouru en entier, mais, au
moins dans le cas oii les fonctions et les donnees sont analytiques, il
a indique les principes qu'ont suivis tons ses continuateurs. Dans les
theoremes relatifs a I'existence des integrales, on emploie des methodes
differentes suivant que les equations et les donnees sont supposees on non
analytiques.
I.
Plagons nous d'abord dans le premier cas, de beaucoup le mieux
elabore. L'idee essentielle de Cauchy consiste dans la consideration des
Seconde Conference. 225
fonctions majorantes. On salt que les difficultes resident surtout dans
la demonstration de la convergence de certaines series entieres que les
equations differentielles permettent de former. Cauchy y parvient par
des comparaisons avec d'autres equations facilement integrables. Pour
les equations differentielles ordinaires, il n'y avait a faire apres Cauchy
que des simplifications de forme, et, pour le cas d'une seule equation aux
derivees partielles, quel que soit le nombre des variables, le grand geo-
metre avait indique aussi les points essentiels de la demonstration, que
Mme. Kovalevski, dans un memoire reste classique, a presentee sous une
forme tres simple. Le tbeoreme fondamental est alors le suivant : Si on
a une equation aux derivees partielles d'ordre n relative a une fonction
2 de j9 + 1 variables independantes x, x^, •••, Xp et que I'equation con-
tienne la derives d'ordre w, — , une integrale sera en general determinee
dx""
si on se donne pour x = a les valeurs de z et de ses derivees par rapport
a x jusqu'a I'ordre n — 1 ; ces donnees sont des fonctions holomorphes de
x^, 2^2' '••' ^p ^^"s ^^ voisinage de a^ a^, •-, a^. On pent done dire, en
s'appuyant sur cet enonce que I'integrale generale de I'equation consideree
depend de n fonctions de p variables independantes. C'etait un point
auquel on tenait beaucoup autrefois de savoir de combien de fonctions
arbitraires dependait I'integrale generale d'une equation aux derivees
partielles ; certains resultats paradoxaux avaient cependant deja appele
I'attention comme les formes diverses de I'integrale generale de I'equation
de la chaleur — = — , qui se presentait tantot avec une, tantot avec
dx^ By
deux fonctions arbitraires. De tels resultats ne nous etonnent plus
aujourd'hui, quand il s'agit comme ici de fonctions analytiques. Nous
n'avons qu'a nous rappeler qu'un nombre fini quelconque de fonctions a
un nombre quelconque de variables independantes ne presente pas, au
point de vue arithmetique, une plus grande generalite qu'une seule fonc-
tion d'une seule variable, puisque dans I'un et I'autre cas I'ensemble des
coefficients des developpements forme simplement une suite enumerable.
Aussi s'explique-t-on que M. Borel ait pu etablir que toute integrale
analytique d'une equation aux derivees partielles a coefficients analy-
tiques pent etre exprimee a I'aide d'une formule ne renfermant qu'une
seule fonction arbitraire d'une variable reelle.
Nous venous de considerer une seule equation aux derivees partielles.
L'etude des systemes d'equations differentielles presentait de plus grandes
226 Emile Pimrd :
difficultes. Une premiere question est tout d'abord restee longtemps
sans reponse ; il etait possible de se demander s'il pouvait exister des
systemes qui comprennent un nombre illimite d'equations distinctes c'est
a dire ne pouvant pas se deduire par differentiation d'un certain nombre
d'entre elles. M. Tresse a etabli qu'un systeme d'equations aux derivees
partielles etant defini d'une maniere quelconque, ce systeme est necessaire-
ment limite, c'est a dire qu'il existe un nombre fini s, tel que toutes les
equations d'ordre superieur a s, que contient le systeme, se deduisent par
de simples differentiations des equations d'ordre egal ou inferieur a s.
II importait ensuite de se rendre compte de la nature des elements
arbitraires figurant dans I'integrale generale. Mme. Kovalevski n'avait
examine que certains systemes composes d'equations en nombre egal a
celui des fonctions inconnues et resolubles par rapport aux derivees
d'ordre le plus eleve de chacune des fonctions, ces derivees etant relatives
a une meme variable x. M. Riquier d'abord, puis M. Delassus ont donne
sous des formes differentes la solution du probleme dans le cas general ;
M. Delassus arrive par des changements de variables a obtenir une forme
canonique completement integrable, et montre que I'integration d'un tel
systeme a m variables se ramene a I'integration successive de m systemes
de Mme. Kovalevski contenant successivement 1, 2, •••, m variables; c'est
en partant de cette propriete qu'on pent demontrer facilement I'existence
des integrales analytiques, et determiner les fonctions et constantes
initiales en nombre fini dont dependent ces integrales.
II semble y avoir eu longtemps chez les mathematiciens quelques hesi-
tations sur ce qu'on devait entendre par integrale generale d'une equation
aux derivees partielles. Si I'on se borne aux cas ou il ne figure dans les
equations que des elements analytiques, et si I'on n'envisage que les inte-
grales analytiques, on considere aujourd'hui, conformement a I'opinion
de M. Darboux, qu'une integrale est generale, si on pent disposer des
arbitraires qui y figurent, fonctions et constantes, de maniere a retrouver
les solutions dont les theoremes de Caucliy et de ses successeurs nous ont
demontre I'existence. Anterieurement, Ampere s'etait place a un autre
point de vue ; dans son grand memoire sur les equations aux differences
partielles, il s'exprime ainsi : " Pour qu'une integrale soit generale, il faut
qu'il n'en resulte entre les variables que I'on considere et leurs derivees a
I'infini que les relations exprimees par I'equation donnee et par les equa-
tions que I'on en deduit en la differentiant." II est bien clair qu'il s'agit
de relations ne renfermant aucune des quantites arbitraires qui figurent
Seconde Conference. 227
dans Fintegrale consideree. Les avis etaient partages entre les geometres,
et on se demandait s'il y a identite entre la definition d' Ampere et celle
de Cauchy. M. Goursat a montre bien nettement, sur differents exemples,
qu'une integrale pent etre generale au sens d' Ampere sans etre generale
an sens de Cauchy.
II ne faudrait pas conclure des divers travaux qui precedent, que, tout
en envisageant seulement des integrales et des equations analytiques,
I'etude des conditions determinant les integrales d'un systeme d'equations
aux derivees partielles soit actuellement achevee. Les theoremes generaux
indiques font connaitre certaines donnees qui determinent une integrale,
mais celle-ci pent etre determinee par une infinite d'autres conditions. II
n'est pas douteux que les types a trouver de ces theoremes d'existence
sent en nombre infini. Prenons I'exemple tres simple de I'equation
•\- a f-o-— -+C2 = U.
bx by dx dy
Une integrale est determinee par la condition de se reduire pour x=0
a une fonction domiee de y^ et pour ?/ = a une fonction donnee de x :
voila un genre de determinations d'une integrale qui ne rentre pas dans
les conditions du theoreme general de Cauchy. Les conditions tres
varices, qui peuvent determiner les integrales des equations aux dif-
ferences partielles appellent encore de nombreuses recherches.
n.
Nous venous de nous placer au point de vue de la theorie des fonctions
analytiques. Comme je le disais hier, il y a souvent grand iuteret, non
seulement a un point de vue philosophique, mais meme en quelque sorte
au point de vue pratique, a adopter des hypotheses plus generales. C'est
encore a Cauchy que Ton doit pour les equations differentielles ordinaires
la demonstration de I'existence des integrales sans supposer les equations
analytiques. Sa methode, bien naturelle et bien simple, consiste a
regarder les equations differentielles comme limites d'equations aux
differences. On pent faire sur cette methode de Cauchy une remarque
tres interessante ; elle est susceptible de fournir des developpements en
series des integrales qui convergent tant que les intSgrales restent continues^
et laissent continues les coefficients differentiels. En ce sens, elle est
228 Emile Picard :
superieure aux autres methodes qui ont ete proposees. Ainsi, pour
prendre un exemple, soit le systeme d'equations
-^ = Xi(x^, x^, •••, x^ {i = 1, 2, ... w)
ou les X sont des polynomes. On pent representer les integrales de
ce systeme prenant pour i= les valeurs x-^^ x^^ •••, x^ par des deve-
loppements de la forme
les P etant des polynomes en x^^x^^ '-'iX^ et t, et ces developpements
sont convergents tant que les integrales restent des fonctions continues
de t.
D'autres methodes ont ete proposees pour demontrer I'existence des
integrales, comme la methode des approximations successives qui donne
pour les series une convergence tres rapide, mais ces series ne convergent
pas necessairement dans tout le champ ou les integrales sont continues.
Pour une equation differentielle ordinaire d'ordre w, on suppose
generalement, quand on veut etablir I'existence des integrales, qu'on se
donne pour une valeur de x les valeurs de la fonction et de ses derivees
jusqu'a I'ordre n — 1, mais on pourrait prendre beaucoup d'autres don-
nees; et c'est ce qui arrive notamment dans les applications du calcul
des variations. Ainsi pour une equation du second ordre, il arrive qu'une
integrale soit determinee par les conditions de prendre pour x^ la valeur
3/q et pour x-^ la valeur y^ On a peu travaille jusqu'ici dans cet ordre
d'idees, et cependant maintes conditions initiales sont aussi interessantes
que celles adoptees dans le theoreme general classique. Les recherches
entreprises dans cette voie ont conduit a quelques resultats par I'emploi
de methodes d'approximations successives, et on a pu ainsi reconnaitre des
cas singuliers de divergence dans I'emploi de ces methodes d'approximation.
Si nous passons maintenant aux equations aux differences partielles,
les equations et les donnees n'etant pas necessairement analytiques, nous
nous trouvons dans un domaine tres etendu ou on n'a fait que les pre-
miers pas. II faut deja quelque soin pour etablir I'existence des inte-
grales de I'equation lineaire
Seconde Conference. 229
sans supposer que X(x^ y) soit analytique. Pour les equations d'ordre
superieur, il n'y a qu'un petit nombre de types pour lesquels on puisse
definir avec precision ce que Ton entend par integrale generale. lis ont
generalement pour origine des problemes de geometrie infinitesimale
ou de physique mathematique ; les variables et les fonctions restent ici
reelles. Prenons, comme exemple, I'equation
b'^z dz ^dz ^
+ a— + b— + cz =
dxdy dx dy
ou «, J, c sont des fonctions continues de x et y^ sur laquelle Riemann
a ecrit quelques pages extremement remarquables. Soit un arc de
courbe MP tel que toute parallele a Oa; et a Oy le rencontre au plus en
dz
un point ; nous nous donnons les valeurs de 2 et — sur cette courbe.
II y aura une integrale et une seule, continue ainsi que ses derivees
partielles du premier ordre, satisfaisant aux conditions donnees, et elle
sera definie dans le rectangle de cotes paralleles aux axes et ayant M et P
pour sommets opposes. On voit combien cet enonce est d'une nature
plus precise que ceux qui ont ete donnes anterieurement en nous plagant
au point de vue de la theorie des fonctions analytiques, ou pour une
equation comme celle-ci on etablit seulement I'existence d'une solution
dans le voisinage d'une courbe, voisinage determine avec tres peu de
precision. L'exemple si simple que nous avons choisi montre encore
qu'il n'existe pas toujours d'integrale continue ainsi que ses derivees
premieres satisfaisant aux conditions donnees sur un arc de courbe ;
il en sera ainsi quand sur cet arc il y aura une tangente parallele a I'un
des axes. Voici un second exemple dans le meme ordre d'idees ; on pent
relativement a I'equation
d'^u B'^u d^u _ „
dx^ dy'^ dz^
die
se donner les valeurs de w et de ^ pour les points d'un cercle situe
dans le plan z = z^; I'integrale ainsi definie est determinee a I'interieur
des deux cones de revolution passant par la circonference et de gene-
ratrices paralleles a celles du cone x^ -{- y^ — z^ = 0.
Les conditions determinant une integrale peuvent prendre des formes
tres diverses. Ainsi des conditions de continuite sont susceptibles de
remplacer certaines donnees : c'est un fait auquel nous sommes tres
230 Emile Picard :
habitues, mais qui n'en est pas moins tres remarquable. L'equation du
potentiel a provoque dans cette voie de nombreuses reclierclies, et le
theoreme fondamental auquel Riemann a donne le nom de Diricblet,
apres avoir ete approfondi par Schwarz et Neumann, a encore fait recem-
ment I'objet des recherches de M. Poincare. Des problemes analogues
ont ete poses et resolus pour un grand nombre d'equations, par exemple
pour l'equation
S^M d^u du , du -,
Fl + r~2 + ^T' + ^T" -I- cw =
ox^ ay^ ox By
pour laquelle une integrale continue est determinee par ses valeurs sur
un contour ferme dans toute region ou le coefficient c est negatif ; de
telles questions ne sont d'ailleurs pas limitees aux equations lineaires.
Ces divers exemples caracterisent bien la nature des theoremes d'exis-
tence des integrales, quand on ne se place pas au point de vue de la
theorie des fonctions analytiques. II y a la un ordre immense de re-
cherches egalement interessantes pour la theorie pure et pour les appli-
cations de I'analyse. Sans meme aborder de questions entierement
nouvelles, que de points seraient a reprendre dans les travaux celebres
des physiciens geometres de la premiere moitie du siecle, de Fourier,
de Poisson, de Cauchy meme, si on voulait y apporter la rigueur que
Ton exige aujourd'hui en mathematiques.
Je dois aj outer d'ailleurs, comme transition entre les deux directions
relatives aux generalites sur les equations aux derivees partielles, qu'il
existe des classes tres etendues d'equations dont toutes les integrales sont
analytiques. Citons les equations lineaires d'ordre n a deux variables
independantes : dans une region du plan ou toutes les caracteristiques
sont imaginaires, toute integrale bien determinee et continue ainsi que
ses derivees partielles jusqu'a I'ordre n est necessairement analytique.
II y a aussi de nombreuses equations non lineaires ayant toutes leurs
integrales analytiques.
Je viens de parler des caracteristiques d'une equation ; c'est la un
sujet en connexion etroite avec les theoremes generaux d'existence qui
viennent de nous occuper. Les caracteristiques sont certaines multipli-
cites jouissant de proprietes particulieres relativement a une equation
donnee, multiplicites singulieres en ce qu'elles ne definissent pas une
integrale contrairement a ce qui arrive en general pour les multiplicites
contenant les memes elements. Tandis que la notion de caracteristiques
Seconde Conference. 231
est aujourd'hui tres nette pour les equations ou systemes d'equations a
deux variables independantes, elle a encore besoin d'etre approfondie dans
le cas de plus de deux variables.
III.
Si, quittant les generalites relatives a I'existence des integrales, nous
voulons parler de la recherche effective des integrales et de I'etude
d'equations particulieres, I'embarras est grand de tenter des classifica-
tions dans un ensemble considerable de travaux, et nous sentons combien
nos classements sont tou jours defectueux par quelque endroit. Peut-etre
pourrait-on tout d'abord distinguer I'ancienne ecole mathematique, et le
mot ^'■ancienne^^ ne veut pas dire qu'elle ne continue pas a prosperer.
C'est I'Ecole d'Euler, de Lagrange, de Monge dans son immortel ouvrage
sur les applications de I'analyse a la geometric, d' Ampere dans son celebre
memoire de 1817 sur les equations aux differences partielles. En France,
cette ecole des analystes geometres pour qui les problemes de geometric
infinitesimale sont I'occasion de belles recherches analytiques, a pour chef
M. Darboux. Ses Legons sur la Thdorie des surfaces sont aujourd'hui
un livre classique qui a rappele I'attention sur des questions quelque
temps negligees. Relativement a I'integration effective des equations du
second ordre, pendant de longues annees apres la publication du memoire
d'Ampere, il n'avait ete rien ajoute d'essentiel a la theorie developpee par
le grand geometre. En 1870, M. Darboux publia un memoire renfermant
des vues profondes et originales qui est fondamental dans I'histoire de
cette theorie. Depuis cette epoque, divers geometres ont developpe des
methodes plus ou moins analogues. M. Goursat vient de rassembler dans
un ouvrage considerable les methodes proposees, en y ajoutant ses decou-
vertes personnelles sur ces questions difficiles. On pent caracteriser
toutes ces recherches, en disant qu'on s'y propose de trouver explicite-
ment des integrales avec le plus grand degre possible d'indetermination.
Quelquefois, les methodes sont des indications de marche a suivre quand
telle circonstance heureuse se presente, et on cherche des classes d'equa-
tions pour lesquelles il en soit ainsi ; dans d'autres cas, on renonce au
moins temporairement a I'integration complete, et on recherche des solu-
tions de plus en plus etendues au moyen de transformations convenables
comme, par exemple, celles de M. Bianchi pour I'equation des surfaces a
courbure constante.
Les idees du grand geometre norvegien, Sophus Lie, dont la science
232 Emile Picard:
deplore la perte recente, ont exerce aussi depuis vingt ans une grande
influence dans I'etude des equations differentielles sous le point de vue
qui nous occupe en ce moment. La theorie des groupes de transforma-
tions, une des plus belles creations mathematiques de ce siecle, est venue
apporter un element incomparable de classification ; elle a permis de faire
une vaste synthese en donnant une origine commune a des notions eparses
qui paraissaient sans liens.
Je disais tout a I'heure que nos classifications se plient difficilement a
la complexite des choses. Certains problemes se trouvent a un confluent,
ou se rencontrent I'ancienne Ecole de Monge et d' Ampere et I'Ecole plus
recente qui se rattache a la theorie moderne des fonctions. Monge avait
integre I'equation des surfaces minima, et c'est la un de ses titres de
gloire. Ses formules ont ete transformees par Weierstrass, et alors a
apparu le lien entre la theorie des fonctions d'une variable complexe et la
theorie des surfaces minima. Un probleme appelle vivement I'attention
dans cette theorie : c'est le probleme de Plateau relatif aux surfaces
minima passant par un contour donne. II a ete resolu seulement dans
des cas tres speciaux ; je crois qu'en exercant la sagacite des analystes il
sera quelque jour 1' occasion de progres importants dans I'analyse generale.
IV.
J'ai surtout parle jusqu'ici des equations aux derivees partielles. La
theorie des equations differentielles ordinaires est plus speciale, d'autant
que quelques uns ont une tendance a la regarder comme un chapitre de la
theorie des fonctions analytiques. Apres les remarques que j'ai faites
hier, je n'ai pas besoin d'ajouter que ce n'est pas la mon opinion ; je vous
ai indique plusieurs problemes qui ne relevent en rien de la theorie des
fonctions analytiques, et il me suffira de citer encore I'extension des idees
de Galois aux equations differentielles. Ceci dit, il n'est pas douteux que
les progres de la theorie des fonctions analytiques ont exerce la plus
heureuse influence sur certains points de la theorie des equations diffe-
rentielles ordinaires. Je ne ferai que rappeler le memoire celebre de
Puiseux sur les fonctions algebriques, dans lequel etudiant a un point
de nouveau les plus simples des equations differentielles a savoir les
quadratures, il revele I'origine de la periodicite des integrales de differen-
tielles algebriques. Les recherches de Briot et Bouquet ne sont pas
moins classiques ; les auteurs y etudient les circonstances singulieres qui
peuvent se presenter dans une equation du premier ordre quand le coefli-
Seconde Conference. 233
cient differentiel devient infini ou iiidetermine. II faiit se reporter a pres
de cinquante ans en arriere pour bien juger ce memoire, ou pour la
premiere fois est mis en evidence le role des points singuliers dans I'etude
des fonctions ; ces notions nous sont bien familieres aujourd'hui, mais
nous ne devons pas oublier que ce sont les memoires de Puiseux et de
Briot et Bouquet qui en ont montre la haute importance. II semble que
le memoire de Briot et Bouquet aurait du etre immediatement I'origine
de travaux dans la meme voie, mais bien des annees se passerent avant
qu'il ne fut repris et complete. C'est en Allemagne, sous I'influence de
I'enseignement de Weierstrass que nous voyons d'abord reparaitre I'etude
des singularites des equations differentielles, et cela pour les equations
differentielles lineaires. II est vraiment curieux que Briot et Bouquet,
apres avoir traite le cas plus difficile des singularites d'une equation non
lineaire, fut-elle du premier ordre, n'aient pas songe a s'occuper des equa-
tions lineaires, laissant a M. Fuchs I'honneur de fonder une theorie, dont
I'illustre geometre allemand a fait lui-meme des applications du plus
haut interet, et qui a provoque un nombre immense de recherches. On
remplirait des bibliotheques avec les memoires composes depuis trente ans
sur la theorie des equations lineaires. Je ne puis songer a vous parler
des nombreuses classes d'equations dont I'etude a ete faite. En restant
dans les generalites, je rappelle seulement que I'etude des points singuliers
presente une grande difference suivant que ce point singulier est regulier,
comme dit M. Fuchs, ou presente les caracteres d'un point singulier
essentiel. Ce dernier cas est de beaucoup plus difficile ; M. Thome a
forme des series satisfaisant formellement a I'equation, mais qui en general
ne sont pas convergentes. Remarquons a ce propos que Briot et Bouquet
ont les premiers montre qu'une equation diiferentielle pouvait conduire a
une serie en general divergente ; leur exemple bien simple est I'equation
x^-^ = ax + hy
dx
verifiee par une serie entiere dont le rayon de convergence est nul. Cette
petite constatation a appele I'attention sur un fait d'une importance
capitale, et qui ne se rencontre que trop frequemment dans les applica-
tions; les developpements purement formels sont nombreux en meca-
nique analytique et mecanique celeste, ou ils font le desespoir des
geometres. Pour les equations lineaires, ces developpement ont un
certain interet, comme I'a montre M. Poincare, au point de vue de la
234 Emile Picard.
representation asymptotique des integrales. On pent d'ailleurs obtenir
et de bien des manieres, una representation analytique des integrales
autour du point singulier. Je dois enfin mentionner, relativement aux
points singuliers irreguliers, les recherches de M. H. von Koch qui a tire
tres heureusement parti dans cette question des resultats obtenus sur les
determinants d'ordre infini.
Revenons aux equations du premier ordre. Briot et Bouquet ont
surtout etudie les singularites en faisant les reductions au type
ax
ou / est holomorpbe et s'annule pour a: = 0, 1/ = 0, et leurs recherches
ont ete depuis completees par la connaissance de la forme analytique des
integrales au voisinage du point singulier. Le cas plus complique de
I'equation
^'"^ = /(^,2/) (^^2) (1)
n'avait fait jusqu'a ces derniers temps I'objet d'aucune recherche depuis
les quelques lignes que lui avaient consacrees Briot et Bouquet. Cette
etude vient d'etre reprise simultanement par M. Horn et par M. Bendix-
son. Ces auteurs se servent d'une methode convenable d'approximations
successives dont j'indiquerai le principe. Nous supposons expressement
que X reste reel et se rapproche de zero par valeurs positives, et posons
f(x, y) = % + F(x, y)
F ne contenant pas de terme du premier degre en y independant de x.
Si la partie reelle de b est positive, I'equation precedente a une infinite
d'integrales tendant vers zero en meme temps que x, et elle n'en a qu'une
quand la partie reelle de b est negative. Les deux cas peuvent etre
traites en faisant les approximation successives
x-^^=by, + F(x,y^^
^ = by, + F(ix,y,_{)
Seconde Conference. 235
et on obtient ainsi une representation analytique des integrales (ou de
I'integrale). II existe un developpement
a-^x + 02^2 4- ••• + a^x" + •••
satisfaisant formellement a I'equation (1), mais dont le rayon de conver-
gence est nul en general ; c'est la generalisation de la remarque de Briot
et Bouquet, et on pent ajouter que la derivee d'ordre n de toutes les
integrales considerees tend vers 1 • 2 ••• w • a„, quand x tend vers zero.
De plus, quand il y a une infinite d'integrales tendant vers zero en meme
temps, elles sont toutes representees asymptotiquement par le meme
developpement, ce qui est evidemment defavorable pour I'interet que
peut presenter une telle representation asymptotique. Les methodes
precedentes sont d'ailleurs susceptibles de s'etendre a un systeme d'equa-
tions differentielles. Je ferai encore i;ne remarque importante sur
I'equation (1) ; le cas ou la partie reelle de h est nulle echappe complete-
ment a la methode. L'equation a en general des integrales qui ne ten-
dent vers aucune limite pour x = 0. On se trouve alors, sur un exemple
tres simple, en presence des difficultes considerables que Ton rencontre
dans plusieurs questions de mecanique analytique; c'est en vain que
Ton a tente jusqu'ici de proceder par approximations successives con-
vergentes et les developpements essayes sont en general divergents.
Quoi qu'il en soit des difficultes restant encore a surmonter, des
progres serieux ont ete realises ces dernieres annees dans I'etude des
integrales des equations non lineaires au voisinage des points singuliers
mis en evidence par la forme meme de I'equation differentielle. De tels
points singuliers sont les seuls que puissent avoir les integrales quand
il s'agit d'une equation lineaire, mais il en est autrement pour les equa-
tions non lineaires. En dehors des points singuliers, qui sont apparents
sur I'equation, il peut y en avoir d'autres variables d'une integrale a
I'autre. Les equations du premier ordre ne presentaient pas a cet egard
de bien grandes difficultes. En se bornant aux equations differentielles
algebriques, tous les points singuliers qui ne sont pas apparents ne
peuvent etre que des points critiques algebriques. Des exemples simples
montraient que pour les equations d'ordre superieur au premier, il n'en
etait plus de meme et qu'il pouvait y avoir des points essentiels mobiles;
I'attention avait ete appelee sur ce point quand on avait voulu etendre
aux equations du second ordre a points critiques fixes les methodes qui
avaient reussi pour les equations du premier ordre possedant la meme
236 Emile Picard:
propriete. La difficulte signalee restait entiere, quand M. Painleve est
venu faire une importante distinction et signaler un fait inatteudu. Les
points singuliers mobiles peuvent se partager en deux classes, les points
singuliers algebriques ou transcendants pour lesquels I'integrale et ses
derivees acquierent une valeur determinee finie ou infinie, et les points
singuliers essentiels. M. Painleve a etabli que, dans les equations diffe-
rentielles algebriques, le cas ou les points singuliers essentiels sont
mobiles est un cas exceptionnel. Ces equations se trouvent ainsi par-
tagees en deux classes, une classe generale pour laquelle I'integrale
generale n'a pas de singularites essentielles mobiles, et une classe singu-
liere. L'interet de cette distinction est tres grand dans I'etude de
quelques classes particulieres d'equations differentielles.
V.
Arretons nous specialement sur le cas ou la variable et les fonctions
restent reelles ; c'est le cas interessant pour les applications. Nous
designerons par t la variable independante qui sera, si Ton veut, le
temps. Pour etudier quantitativement les fonctions definies par les
equations differentielles, c'est a dire pour pouvoir evaluer numerique-
ment les valeurs de ces fonctions, on doit desirer d'avoir des represen-
tations de celles-ci permettant de les calculer pour un intervalle de temps
aussi grand que possible. H y a des classes assez etendues d'equations
differentielles, d'apres la forme desquelles on est assure d'obtenir des
developpements valables pour toute valeur de t. Un cas tres simple
est celui des equations
dv •
-^ =fi(t, yi, ^2' •••' Vn') (*' = 1, 2, •••, W).
On suppose que les fonctions / restent continues pour toutes les
valeurs reelles et finies de t et des ^, et que de plus les derivees -^
restent en valeurs absolues moindres qu'un nombre fixe. La metliode
de Cauchy ou la methode des approximations success! ves donne pour
les y des developpements valables pour toute valeur du temps.
En supposant que les fonctions / soient analytiques et regulieres
pour toute valeur reelle finie ou infinie de t et des y, on pent proceder
autrement dans la recherche d'un developpement valable pour toute
valeur du temps. II suffit de faire, avec M. Poincare, une representa-
tion conforme, sur un cercle situe dans le plan d'une variable z, d'une
Seconde Conference. 237
bande tres petite dans le plan de la variable t (supposee un instant
complexe), bande parallele a I'axe reel, ce qui revient a poser
e"' + l
On pent ici proceder encore d'une autre maniere en se rappelant que
M. Painleve a etabli que toute fonction holomorphe d'une variable reelle
dans un intervalle peut etre developpee en une serie de polynomes dont
les coefficients dependent lineairement des valeurs de la fonction et de
ses derivees pour une valeur particuliere t = t^,
II y a des cas ou I'equation ne rentre pas dans les types precedents,
et ou Ton sera cependant, au moins pour certaines integrales, assure de
la possibilite d'un developpement toujours valable. Je citerai comme
premier exemple les equations
ou « et 6 sont deux constantes positives ; / et ^ designe des series holo-
morplies en -, x et y, et ne renfermant pas de termes constants et de
termes du premier degre en x et y. II est aise d'etablir que, pour
t=tQ suffisamment grand, les valeurs initiales etant suffisamment petites,
les integrales correspondantes tendront vers zero pour t=oo. De tels
exemples sont malheureusement tres rares ; on peut encore citer les
problemes de mecanique ou il y a une fonction des forces. Chacun salt
que I'equilibre est stable, dans le voisinage d'une position ou la fonction
des forces est maxima, mais ce resultat classique provient de I'etude
indirecte des equations differentielles ; le meme probleme nous montre
vite combien une etude directs serait desirable, et combien de difficultes
restent a vaincre. Ainsi, supposons qu'il n'y ait pas de fonction de
forces et bornons nous a un point materiel. Ecrivons les equations
•^=ax + hy+... -^=a'x + h'y+... (2)
ou les seconds membres sont des developpements suivant les puissances
de x et y, et convergents pour x et y assez petits. Le point x=-0, y=0
correspond-il a une position d'equilibre stable ? II est impossible ac-
tuellement de repondre a cette question. II y a peut-etre quelques
mecaniciens qui croient que la nature de I'equilibre depend seulement
238 Emile Picard :
des termes du premier degre dans le second membre. Nous nous garde-
rons bien de leur en vouloir, car c'etait au fond I'erreur de Lagrange,
mais il est clair qu'en reduisant les equations a la partie lineaire, on pent
avoir une solution stable qui cesse de I'etre quand on retablit les termes
d'ordre superieur. Les equations (2) presentent une particularite curi-
euse qui merite d'etre signalee. On pent se proposer de trouver une
integrale premiere
F etant en holomorphe en a:, y, x\ y\ et commengant par des termes du
second degre. Or on trouve une telle fonction F au point de vue formel,
mais la serie ainsi obtenue ne converge pas en general. J'ajoute que,
si la force dependait non seulement de la position du point mais de la
vitesse, c'est-a-dire si dans (2) les seconds membres dependaient aussi
de d et y, la recherche de la fonction F ne pourrait plus generalement
etre effectuee, mais il serait plus facile de repondre a la question relative
a la stabilite.
Quand on a aucune notion de la grandeur de I'intervalle pour lequel
les fonctions definies par les equations differentielles sont continues, on
pent cependant trouver des developpements valables pour tout le temps
pendant lequel les fonctions resteront continues. J'ai dit tout a I'heure
que Ton pouvait deduire de tels developpements de la methode classique
de Cauchy ; c'est la un resultat interessant, mais malheureusement il
n'a guere qu'un interSt theorique, car il semble bien difficile de deduire
de ces developpements quelques renseignements sur le champ ou les
integrales restent continues.
II y aura cependant des cas ou certaines proprietes auxiliaires des
equations permettent d'avoir des renseignements sur le champ ou les
integrales restent continues. Que Ton prenne, par exemple, les six
equations classiques en j9, 5-, r, ?/, y\ y" relatives au mouvement d'un
solide pesant suspendu par un point ; I'integrale des forces vives et
I'integrale ?/^ 3/'^, y"^ = const, permettent de reconnaitre que les six
fonctions precedentes resteront finies pour toute valeur du temps, et
nous sommes alors assure que pour ce probleme la methode de Cauchy
donne des developpements valables pour toute valeur du temps.
Seconde Conference. 239
VI.
A I'ordre d'idees qui nous occupe, se rattachent les travaux de M.
Poincare sur les solutions periodiques, et sur les solutions asymptotiques.
L'etude des solutions periodiques d'une equation differentielle presente
un interet particulier. Je connais peu d'exemples ou on puisse trouver
directement une solution periodique. Dans ses travaux sur ce sujet, M.
Poincare procede par voie indirecte ; il profite de la presence d'une con-
stante tres petite dans les equations, et il raisonne par continuite en par-
tant d'une solution periodique pour la valeur zero de cette constante. II
serait a desirer que Ton put penetrer par une autre voie dans l'etude des
solutions periodiques. Quant aux solutions asymptotiques a une seule
solution, leur etude resulte de developpements analytiques simples ; mais
I'existence dans certains cas particuliers de solutions doublement asymp-
totiques, c'est a dire de solutions asymptotiques pour < = — qo a une
solution periodique et de nouveau asymptotiques pour ^ = + oo a cette
meme solution etait extremement cachee, et leur decouverte a demande
un effort considerable.
L'etude des courbes definies par les equations differentielles est sur-
tout une etude qualitative. Si Ton considere d'abord une equation du
premier ordre et du premier degre.
r^ = ^ (X et Y polynomes en x et y) (2)
l'etude des points singuliers generaux se deduit des resultats de Briot et
Bouquet. Ces points se partagent en trois types, que M. Poincare ap-
pelle des cols, des nceuds et des foyers. Un point singulier d'une nature
deja plus compliquee est fourni par ce que M. Poincare appelle un centre,
qui en general presente de I'analogie avec les foyers mais autour duquel
dans certains cas I'integrale constitue une courbe fermee. On a alors un
exemple de solutions periodiques dont la periode depend des conditions
initiales. Les travaux les plus recents sur les points singuliers de courbes
integrales de I'equation (2) sont dus a M. Bendixson ; le savant geometre
suedois a etabli en particulier que s'il existe pour I'equation (2) une
courbe integrale allant a I'origine avec une tangente determinee, toutes
les courbes integrales allant a I'origine y parviendront avec des tangentes
determinees.
L'etude des courbes integrales ne doit pas etre bornee au voisinage
des points singuliers ; on doit cherclier a se rendre compte de leur forme
240 Emile Picard :
sur le plan tout entier ou sur la sphere en faisant une perspective. Si
Ton cliemine, pour I'equation (2), sur une courbe integrale, qu'arrivera-
t-il ? Cette courbe pent etre fermee de telle sorte qu'on reviendra au
point de depart ; elle peut aussi avoir un des foyers comme point asymp-
tote. Elle peut avoir encore pour courbe asymptote une courbe fermee
satisfaisant d'ailleurs a I'equation differentielle. Ces courbes fermees, que
M. Poincare appelle cycles limites jouent un role capital, et c'est dans les
cas ou il est possible de se rendre compte de leur position que la dis-
cussion de I'equation peut etre faite d'une maniere complete.
Pour les equations du premier ordre mais de degre superieur les dif-
ficultes sont beaucoup plus grandes. L'etude des points singuliers ge-
neraux a ete faite ; elle trouve en particulier son application dans des
problemes comme celui des lignes de courbure d'une surface passant par
un ombilic. L'etude des courbes dans tout le plan est singulierement
compliquee par un fait qui ne pouvait se rencontrer pour les equations
du premier degre. II peut arriver qu'une courbe integrale couvre une
aire, c'est a dire puisse se rapprocher autant qu'on voudra d'un point
arbitraire dans une aire.
D'apres les difficultes que presentent encore les equations du premier
ordre, il est clair que pour les equations d'ordre superieur au premier
l'etude qualitative des integrales sollicitera longtemps encore I'effort des
chercheurs. Au point de vue analytique, une circonstance importante est
a noter. Tandis que pour le premier ordre, on peut tirer parti dans quel-
ques cas comme celui des centres de certains developpements en serie, il
arrive au contraire ici dans les cas correspondants que les developpements
analogues sont purement f ormels ; nous en avons vu un exemple en par-
lant tout a I'heure de la stabilite de I'equilibre. Remarquons a ce propos
que les questions d'instabilite sont beaucoup plus faciles a traiter que les
questions de stabilite comme il resulte des interessantes recherches de M.
Liapounoff. Quand il y a une fonction des forces I'equilibre est stable
si, pour cette position, la fonction des forces est maxima. Quant aux
positions d'equilibre pour lesquelles cette derniere condition n'est pas
remplie, on les a toujours regardees comme instables, mais leur instabilite
n'avait pas ete demontree. M. Liapounoff I'a etablie en particulier pour
le cas que I'on peut appeler general ou la non existence du maximum de
la fonction des forces se reconnait par les termes du second ordre.
Je citerai seulement un exemple relatif aux courbes integrales d'une
equation d'ordre superieur au premier. Dans un memoire recent, M.
Troisieme Conference. 241
Hadamard vient d'etudier les lignes geodesiques des surfaces a courbures
opposees et a connexion multiple ayant un nombre limite de nappes in-
finies. II etablit que les tangentes aux lignes geodesiques passant par un
point de la surface, et restant a distance finie, forment un ensemble par-
fait non continu. Ce resultat est interessant au point de vue de la dispo-
sition des lignes geodesiques de la surface ; il montre qu'il existe des
lignes geodesiques se rapprochant d'une geodesique fermee determinee,
puis abandonnant celle-ci pour se rapprocher d'une autre, puis passant a
une troisieme, et ainsi de suite indefiniment. II montre de plus que
Failure des courbes integrales pent dependre dans certains cas, des pro-
prietes discontinues je veux dire arithmetiques des constantes d'integra-
tion. C'est sur cette idee que je veux m'arreter ; dans la theorie des
equations differentielles comme en maintes parties des mathematiques, les
recherches sont obligees de prendre un caractere arithmetique. C'est
V arithmStisation des matliematiques dont parlait M. Klein dans un article
recent.
J'ai essaye, messieurs, en restant dans les generalites et sans prendre
aucune classe particuliere d'equations, de faire une sorte de carte geogra-
phique sommaire de la theorie des equations differentielles. Beaucoup
de voies sont ouvertes et dans des directions tres varices ; sur plus d'un
point, les questions sont seulement posees, mais elles paraissent bien
posees ; et nous nous rendons compte, ce qui a son prix, de la nature des
difficultes qu'il faudra vaincre. C'est une etroite alliance entre les dis-
ciplines les plus diverses qui amenera maintenant de nouveaux progres.
II n'est plus permis aujourd'hui au geometre inventeur d'etre I'homme
d'un seul point de vue, et il faut nous resigner a de grandes complica-
tions. C'est un privilege que les sciences matliematiques partageront
probablement dans I'avenir avec d'autres sciences. Esperons seulement
que des hommes de genie viendront, de loin en loin, donner au moins pour
un temps I'illusion de la simplicite.
Troisieme Conference.
Sur la Theorie des Fonctions Analitiques et sur quelques Fonctions Speciales.
La theorie des fonctions de variables complexes est de venue aujourd'hui
une branche considerable de I'analyse mathematique. EUe doit son bril-
lant essor a la decouverte de quelques propositions generales parmi les-
quelles se trouvent au premier rang les theoremes de Cauchy sur les
242 Emile Picard:
integrales prises le long d'un contour. Ces lois generales des fonctions
analytiques appliquees a des fonctions speciales donnent souvent avec
facilite leurs principales proprietes. L'application de ces lois constitue
une methode syntlietique, et des resultats auxquels avaient conduit une
longue serie de transformations de calculs apparaissent quelquefois avec
une evidence intuitive. La theorie des fonctions elliptiques en offre un
memorable exemple, et n'y a-t-il pas quelque chose de merveilleux a
integrer avec M. Hermite le long d'un parallelogramme de periodes
et a obtenir ainsi d'un trait de plume les principales proprietes des
fonctions doublement periodiques ? La fagon dont Riemann pose et
resout dans sa dissertation inaugurale le probleme des integrales abe-
liennes n'est pas moins digne d'etre meditee comme exemple d'une
methode synthetique dans la theorie des fonctions.
I.
II n'est plus douteux aujourd'hui que les principes essentiels qui sont
a la base de la theorie n'aient ete connus de Gauss. On sait que celui-ci
ne publia pas ses recherches sur ce sujet. On ne pent guere admettre
qu'il n'en ait pas saisi la haute importance ; fidele a sa devise " pauca sed
matura " il attendait sans doute de s'etre livre a une plus longue elabora-
tion, quand Cauchy fit connaitre ses decouvertes. On doit done regarder
Cauchy comme le veritable fondateur de la theorie appelee a un si grand
avenir ; non pas certes qu'il I'ait presentee sous une forme didactique.
Ouvrant des voies nouvelles, son esprit toujours en travail se souciait peu
de donner a ses conceptions une forme parfaite. On suit le travail
d'invention dans maintes publications de Cauchy, notamment quand on
parcourt dans ses GEnvres Completes les notes innombrables extraites des
Comptes-Rendus. Dans la theorie qui nous occupe, une place a part doit
etre faite a I'idee fondamentale d'etendre la notion de I'integrale definie
en faisant passer la variable par une succession de valeurs imaginaires ;
cette conception a ete la source des plus belles decouvertes, et la represen-
tation d'une fonction par une integrale le long d'un contour ferme gardera
a jamais le nom d'integrale de Cauchy.
Le point de depart de Riemann se rapproche beaucoup de celui de
Cauchy ; il est tres philosophique de prendre comme base les deux equa-
tions simultanees
du _dv du _ dv
dx dy dy dx
Troisieme Conference. 243
et de reduire ainsi la theorie des fonctions d'une variable complexe a
I'etude de ces deux equations simultanees aux derivees partielles. En
meme temps apparaissent les liens entre cette etude et plusieurs questions
de physique mathematique comme le mouvement permanent des fluides
sur un plan et celui de relectricite sur une plaque conductrice ; et tous
ces problemes sont susceptibles d'etre generalises si au plan simple dans
lequel se meut la variable (x, y) on substitue le plan multiple de Riemann.
Les deux relations ecrites plus haut amenent a considerer I'equation Aw= 0,
equation qui contient toute la theorie des fonctions d'une variable com-
plexe, et parmi les problemes qu'on pent se poser sur cette equation le
plus celebre est celui de la determination d'une integrale par ses valeurs
sur un contour ferme. Une application d'une autre nature concerne la
geometric ; je veux parler du probleme des cartes geographiques qui amene
a la question de la representation conforme d'une aire sur une autre.
Weierstrass a edifie la theorie des fonctions de variables complexes sur
une autre base que Cauchy et Riemann, en partant des developpements en
series entieres ; en France, ces developpements avaient ete aussi envisages
par M. Meray qui n'avait pas connaissance des legons de Weierstrass.
Le memoire public en 1876 par I'illustre analyste de Berlin, qui a fait
connaitre a un public plus etendu les resultats developpes depuis long-
temps dans I'enseignement du maitre, a ete le point de depart d'un grand
nombre de travaux sur la theorie des fonctions. Cauchy avait deja obtenu
d'importants resultats sur le developpement en sommes ou en produits
infinis de certaines categories de fonctions. II etait reserve a Weierstrass
et a ses disciples de traiter ces questions dans toute leur generalite. La
decomposition des fonctions entieres, c'est a dire des fonctions uniformes
et continues dans tout le plan, en facteurs primaires est un des plus
admirables theoremes de I'analyse moderne ; chacun de facteurs primaires
est le produit d'un facteur lineaire par une exponentielle. Les developpe-
ments des fonctions uniformes en sommes et en produits infinis ont fait
ensuite I'objet d'un grand nombre de travaux parmi les quels il faut citer
tout particulierement le memoire de Mittag-Leffler qui a aborde ces prob-
lemes avec la plus grande generalite possible. Je rappellerai aussi un
memoire de M. Runge auquel des recherches toutes recentes viennent de
redonner de I'actualite, ou se trouve en particulier etabli que toute
fonction holomorphe dans un domaine connexe pent dans ce domaine
etre developpee en une serie de polynomes.
Cauchy et ses disciples frangais, en etudiant la theorie des fonctions
244 Emile Picard:
uniformes, n'avaient pas penetre dans I'etude de ces points singuliers
appeles aujourd'hui points singuliers essentiels, dont le point z= Q pour
1
la fonction e' donne I'exemple le plus simple. La consideration des
facteurs primaires permit a Weierstrass de montrer que dans le voisinage
d\in point essentiel isole une fonction uniforme pent se mettre sous la
forme d'un quotient de deux fonctions uniformes n'ayant pas de poles
dans le voisinage de a ; Weierstrass montra aussi que dans le voisinage
d'un tel point la fonction s'approclie autant que Ton veut de toute valeur
donnee. On a plus tard complete ce resultat, en etablissant que dans le
voisinage d'un point singulier essentiel isole la fonction prend rigoureuse-
ment une infinite de fois toute valeur donnee, une exception seulement
etant possible pour deux valeurs particulieres au plus. La demonstra-
tion de ce theoreme se deduit de la consideration d'une fonction pre-
sentant precisement la propriete qu'on veut demontrer etre impossible ;
cette fonction est la fonction modulaire de la theorie des fonctions
elliptiques, mais ses points singuliers ne sont pas isoles. Un corollaire
du theoreme indique conduit a la proposition suivante relative aux fonc-
tions entieres : si, pour une fonction entiere G-iz) il existe deux valeurs
a Qt h telles que les deux equations G-(z) = a et G-(z) = h aient seulement
un nombre limite de racines, la fonction G-(z) est un polynome.
De nombreuses tentatives ont ete faites pour demontrer directement
les theoremes precedents sans recourir a la theorie des fonctions ellip-
tiques. Pour le theoreme sur les fonctions entieres, M. Hadamard avait
reussi a I'etablir quand, la fonction entiere etant representee par ^ «ot^"S
on a (a„) < — — — , a etant positif . Plus recemment M. Borel est
arrive a le demontrer pour toutes les fonctions entieres et meme a le
generaliser considerablement.
Les travaux de M. Hadamard et de M. Borel publics dans ces
dernieres annees sont extremement remarquables. Dans ces recherches,
une notion importante introduite par Laguerre, celle du genre d'une
fonction entiere, joue un role capital ; ce qui fait I'iuteret de cette
notion, c'est qu'elle est intimement liee a la distribution des racines
de la fonction. M. Poincare avait fait le premier la remarque que
le genre d'une fonction entiere est en relation etroite avec I'ordre de
grandeur de la fonction pour les grandes valeurs de la variable. M.
Hadamard a cherche une limite du genre a I'aide des coefficients du
Troisieme Conference, 245
developpement, et il a ^tabli que si le coefficient de x"^ est moindre que
J-, la f onction est de genre E en designant par E +1 I'entier
(1 . 2 ••• my
immediatement superieur k \. II a reussi aussi a demontrer que, en
designant par <^(w) une fonction croissant indefiniment avec m, si le
coefficient a^ decroit plus vite que la. p^"^^ racine a un module
[(w)]"'
superieur a (1 — €}(j>(p} ou e est infiniment petit pour p = ao . De ses
resultats, M. Hadamard a fait une belle application a I'etude de la distri-
bution des racines d'une fonction celebre consideree par Riemann dans son
memoire sur les nombres premiers.
Dans son travail sur les zeros des fonctions entieres, M. Borel a eu
surtout pour objet la demonstration de I'impossibilite de certaines iden-
tites. Soit yu,(r) une fonction positive croissant indefiniment avec r.
Designons par (x,(3) une fonction entiere dont le module maximum pour
(z) = r est inferieur a e'^^^\ et Hi(z) une fonction entiere dont le module
maximum est superieur a [/a(0]^^"' ^ etant positif ; I'identite
ne peut avoir lieu que si tous les Gr sont identiquement nuls. En particu-
lier pour w = 2, une pareille identite ne peut exister, (tq etant une
constante, (r^ et G-^ des polynomes : c'est le theoreme enonce plus baut sur
les fonctions entieres.
Apres ces resultats sur les fonctions bolomorphes dans tout le plan,
revenons aux series entieres dont le rayon de convergence est fini. Une
telle serie donne, pour employer le langage de Weierstrass, un element de
fonction, en supposant bien entendu que le rayon de convergence n'est
pas nul. L'extension analytique d'un tel element joue un role capital
dans la theorie de Weierstrass ; il est dans cette etude du plus haut
interet d'avoir des renseignements sur les singularites de la fonction sur
le cercle de convergence. Le memoire de M. Darboux sur I'approxima-
tion des fonctions de tres grand nombres, les recherches plus recentes de
M. Hadamard, de M. Borel et de M. Fabry ont conduit a des resultats
d'un haut interet. Je ne veux signaler qu'une consequence curieuse,
entrevue deja par M. Pringslieim : c'est qu'une serie entiere a en general
son cercle de convergence comme coupure. On salt que Weierstrass a le
premier indique un exemple d'un serie entiere ne pouvant etre prolongee
analytiquement an dela de son cercle de convergence, et cet exemple
246 Bhnile Ficard :
detourne provenait de la theorie des fonctions elliptiques. II est vrai-
ment singulier que Ton ait eu autrefois quelques difficultes pour trouver
des exemples de ce que Ton doit considerer maintenant comme la circon-
stance la plus frequente.
Parmi les methodes proposees pour I'etude de la serie prolongee au
delii de son cercle de convergence, il en est deux qui sont particuliere-
ment simples. La premiere, employee par M. E. Lindeloff repose sur la
theorie de la representation conforme ; la seconde utilise la notion de
serie divergente sommable resultant des travaux de M. Borel. Cette
notion semble devoir jouer dans plusieurs questions d'analyse un role
important. J'en indiquerai en deux mots le principe. Soit une serie,
Mq + Mj + ••• w„ + ••• ; on lui associe la fonction de a:
L'expression
s = Cu(a)e^da
pent avoir un sens quand la serie initiale est divergente ; on la regarde
alors comme la limite de la serie. En appliquant cette notion a la pro-
gression geometrique qui represente •, et en se servant de I'integrale
de Cauchy, on est alors conduit a une expression analytique qui dans bien
des cas represente la fonction dans une aire exterieure au cercle de con-
vergence.
Je ne puis songer a rappeler, ne fut-ce que d'un mot, les etudes les plus
importantes faites tout recemment sur le prolongement analytique. Arre-
tons nous seulement sur un resultat que vient de publier M. Mittag-Leffler.
Considerons, avec I'eminent geometre suedois, un element de fonction dans
son cercle de convergence, et sur chaque rayon suivons la fonction
jusqu'a ce que nous rencontrions un point singulier, celui-ci pouvant
d'ailleurs etre a I'infini. On ne garde sur chaque rayon que la portion
comprise entre le centre et le premier point singulier, et on obtient ainsi
une aire que M. Mittag-Leffler appelle Vetoile correspondant a I'element
de fonction. II montre qu'on pent obtenir une representation de la fonc-
tion dans toute I'etoile, sous la forme d'une serie ayant pour termes des
polynomes en x dont les coefficients sont lineaires par rapport aux coeffi-
cients du developpement initial ; de cette faQon, quand on a en un point
la valeur d'une fonction analytique et de toutes ses derivees, on pent
Troisieme Conference. 247
obtenir a I'aide de ces seules donnees une representation de la fonction
valable dans toute une etoile. Ce resultat pourra peut-etre avoir un cer-
tain interet pour la tlieorie des equations differentielles ; il faut toutefois
observer que dans ce cas la methode de Cauchy, comme nous I'avons dit
hier, conduit au meme resultat. Ainsi les series considerees bier (page
18), constituent des developpements valables dans une etoile.
Nous avons, dans ce qui precede, considere un element de fonction, c'est
a dire que la serie , , , m , r^\
avait un rayon de convergence different de zero. Si la serie precedente
ne converge que pour a; = 0, elle ne represente rien et il semble qu'il n'y
ait aucun probleme a se poser a son sujet. Cependant nous avons donne
hier des exemples d'equations differentielles conduisant a de tels developpe-
ments; la derivee d'un ordre quelconque m de certaines integrales dans
un certain angle ayant I'origine pour sommet tend vers 1 • 2 •••m • a,„ quand
X tend vers zero a I'interieur de Tangle convenable A. Ces conditions re-
latives aux valeurs des derivees ne peuvent manifestement determiner une
seule fonction dans Tangle A pres de I'origine, car on pent a une pre-
miere fonction aj outer une exponentielle de la forme e~^ (a etant convena-
blement cboisie) dont toutes les derivees sont nulles a I'origine ; mais, en
appliquant sa metbode de sommation des series divergentes, M. Borel est
conduit a imposer une condition supplementaire et a obtenir alors, dans des
cas etendus, une fonction unique determinee par la serie divergente (1).
n.
Les divers travaux que je viens de rappeler montrent avec quelle
activite les analystes se sont occupes dans ces derniers temps des gene-
ralites concernant les fonctions analytiques d'une variable. La tbeorie
generale des fonctions de plusieurs variables avance beaucoup moins
rapidement ; les questions qui se posent ici sont beaucoup plus difficiles,
tant en elles-memes que par le defaut d'une representation qui fasse
image. Nous suivons une variable complexe sur son plan, mais avec
deux variables complexes nous nous trouvons dans un espace a quatre
dimensions, ou de plus les diverses coordonnees ne se presentent pas
symetriquement. Au lieu de deux equations, nous avons quatre equa-
tions aux derives partielles auxquelles doivent satisfaire deux fonctions
de quatre variables. L'elimination d'une des fonctions conduit pour
Tautre a un systeme de quatre equations aux derivees partielles qui
248 Emile Picard :
remplace I'equation de Laplace, mais qui n'a pas ete etudie directement
comme cette derniere equation. II semble qu'on ne puisse pour ce sys-
teme se poser aucun probleme analogue a celui de Dirichlet et de Rie-
mann ; nous ne trouvons ici aucune analogie entre le cas d'une variable
et celui de deux variables.
A un autre point de vue, le developpement de Taylor a deux variables
pent bien servir a definir un element de fonction, mais nous n'avons rien
d'analogue au cercle de convergence. Que sont les regions de conver-
gence pour un tel developpement? II faudrait considerer des surfaces
dans I'hyperespace a quatre dimensions ; aucune regie n'etant connue
a cet egard, on se borne a considerer deux cercles assez petits dans les
plans respectifs des deux variables, cercles a Finterieur desquels la serie
est convergente.
Les theoremes generaux sur les fonctions analytiques de deux
variables complexes sont peu nombreux. Une remarque souvent utile
a ete faite il y a longtemps par Weierstrass ; elle a en quelque sorte
pour objet de mettre en evidence, dans une fonction de n variables
holomorphes autour de 2:^ = 0, ••., a;„= 0, et s'annulant pour ces valeurs
des variables, la partie de la fonction qui s'annule. Weierstrass montre
que autour de a^^ = ••• = 2:„ = la fonction peut se mettre sous la forme
d'un produit de deux facteurs holomorphes, dont Fun ne s'annule pas
a Forigine et dont Fautre est un polynome par rapport a Fune des
variables. Une autre proposition d'une demonstration delicate est due
a M. Poincare et a pour objet de generaliser le theoreme de Weierstrass
relatif aux fonctions uniformes d'une variable n'ayant a distance finie
que des poles, fonctions qui peuvent se mettre sous la forme d'un quotient
de deux fonctions entieres. Pareillement une fonction de deux variables
qui, pour toutes les valeurs finies des variables presente le caractere d'une
fonction rationnelle peut etre mise sous la forme d'un quotient de deux fonc-
tions entieres. Ce beau theoreme a ete etendu par M. Cousin, qui a suivi
une toute autre voie, aux fonctions d'un nombre quelconque de variables.
On doit encore a M. Poincare un resultat bien saillant : je veux
parler de Fextension aux integrales doubles du theoreme fondamental
de Cauchy relatif aux integrales simples prises le long d'un contour. II
n'y a pas de difficulte a definir une integrale double d'une fonction
F(x^ y) de deux variables complexes x Qt y
ff^C^^ y)^^^y
Troisieme Conference. 249
sur un continuum a deux dimensions situe dans I'hyperespace a quatre
dimensions qui correspond aux deux variables complexes. Si le con-
tinuum est ferme, et qu'on puisse le reduire a une ligne oii a un point
sans que I' cesse d'etre continue, I'integrale sera nulle. Ce resultat
conduit a poser un grand nombre de questions. Si F est une fonction
rationelle, il y a lieu de considerer les residus de I'integrale double ; ces
residus s'expriment par des periodes d'integrales abeliennes ordinaires.
Si F est une fonction algebrique de x et 3/, on aura a envisager les
pSriodes de I'integrale double, et on voit s'ouvrir un vaste champ de
recherches. On s'apergoit d'ailleurs bien vite que si certaines analogies
subsistent avec le cas d'une variable, il en est beaucoup d'autres qui
disparaissent entierement. Des integrales le long d'un contour out
donne a Cauchy le nombre des racines d'une equation contenues dans
ce contour, mais dans la question correspondante du nombre des racines
communes a deux equations simultanees, les integrales doubles n'ont
aucun role a jouer ; ce sont des integrales triples etendues a un certain
continuum a trois dimensions qui interviennent dans cette recherche.
Je parlais tout a I'heure de la dissymetrie qui se presente au point
de vue reel dans la theorie des fonctions de deux variables complexes.
II etait interessant de rechercher si il n'est pas possible de generaliser
les deux equations aux derivees partielles de la theorie d'une fonction
d'une variable. Le probleme est evidemment indetermine ; tout depend
de la propriete de ces equations sur laquelle on porte specialement son
attention. On pent se placer au point de vue suivant : rechercher tons
les systemes d'equations aux derivees partielles relatifs a n fonctions de
n variables independantes et telles que, si Up u^, '"Un 6t v^ v^, •••v„ de-
signent deux solutions quelconques, les v considerees comme fonctions
des u satisfassent au meme systeme. Cette propriete appartient evidem-
, ' ,• du dv du dv r 111
ment aux deux equations ■r-=T— ? 7- = — t-« -Lia recherche de ces sys-
ox oy oy ax
temes pent se faire d'une maniere reguliere, et pent se deduire de la
connaissance des certains groupes d'ordre fini ; ainsi tons les systemes
du type precedent d'equations aux derivees partielles du premier ordre
pourront etre obtenus a I'aide des groupes lineaires et homogenes a n
variables. II est possible que, parmi tous ces systemes, il en est qui
presentent quelque interet particulier, et avec lesquels on puisse edifier
une theorie plus ou moins analogue a la theorie d'une fonction d'une
variable complexe. Le cas de w = 3 ne donne rien d'interessant ; pour
250 Emile Picard :
w = 4, on pourrait prendre d'abord le groupe lineaire qui donne naissance
aux quaternions, il lui correspond un systeme d'equations differentielles
qui presente peut-etre quelque interet.
Cette extension de la theorie des fonctions d'une variable complexe
n'est pas la seule qui ait ete proposee. M. Volterra a cherche dans une
autre voie en considerant des fonctions de ligne, ce qui I'a conduit a
d'interessantes relations differentielles et a quelques problemes analogues
a ceux de Dirichlet. L'avenir dira si ces extensions sont simplement des
curiosites ou si elles presentent quelque interet general.
III.
Quittons maintenant les generalites et jetons un coup d'oeil sur
quelques fonctions speciales. II n'en est pas qui aient ete plus etudiees
que les fonctions algebriques d'une variable ; c'est en faisant leur etude
que Puiseux, dans un niemoire reste celebre, a appele I'attention sur
I'interet que presentait la consideration de la variable complexe. On
a quelque peine a se representer qu'il a paru merveilleux que Vi et — Vi
puissent etre considerees comme deux determinations d'une meme fonc-
tion ; c'est dans ce memoire aussi qu'apparait pour la premiere fois
I'origine de la periodicite.
La theorie des fonctions algebriques est devenue un confluent ou se
rencontrent les notions les plus diverses ; chacun, suivant ses gouts, pent
y trouver les points de vue qu'il prefere. Avec les metliodes de Weier-
strass, nous trouvons la precision extreme qui caracterise son ecole, et le
souci constant de n'introduire aucune consideration etrangere a la theorie
des fonctions fut ce au prix de detours longs et penibles. Celui qui aime
le langage et les formes de raisonnement de la geometrie analytique
suivra Brill et Noether dans leur theorie si feconde des groupes de
points. Ceux enfin qui recherchent les grands horizons auront plaisir
a lire Riemann qui, avec la merveilleuse conception de la surface qui porte
son nom, rend, pour ainsi dire, intuitifs les points les plus delicats de la
theorie. Ce serait d'ailleurs une vue etroite que de regarder seulement
la belle conception de Riemann comme une methode simplicative. Pour
Riemann, le point essentiel est dans la conception a priori de la surface
connexe, formee d'un nombre limite de feuillets, et dans le fait qu'a une
telle surface congue dans toute sa generalite correspond une classe de
courbes algebriques. De plus, on pent envisager des surfaces de Riemann
a un nombre infini de feuillets, et les travaux de Poincare ont montre le
Troisieme Conference. 251
role utile qu'elles peuvent jouer dans I'etude des fonctions non uniformes.
On salt aussi I'importance qu'avait pour Riemann le probleme de la repre-
sentation conforme ; le cas de la representation conforme des aires a
connexions multiples a ete traite par M. Schottky dans un tres beau
memoire ou I'auteur se montre disciple de Weierstrass, mais qui se rat-
tache naturellement a I'ordre d'idees de Riemann. A une aire plane
percee de p trous, envisagee comme ayant une face superieure et une face
inferieure correspond une courbe algebrique de genre p ; la question de
la representation conforme de deux aires revient alors a la correspondance
entre les points de deux courbes algebriques.
Aux courbes algebriques se rattachent des fonctions extremement re-
marquables d'une variable ; ce sont les fonctions que M. Poincare appelle
fuchsiennes et que M. Klein designe sous le nom de fonctions automorphes.
Pour les courbes des genres zero et un, on pent exprimer les coordonnees
par des fonctions uniformes d'un parametre, meromorphes dans tout
le plan (fonctions rationnelles et fonctions doublement periodiques).
II etait naturel de chercher, pour les courbes de genre superieur a un, une
representation parametrique par des fonctions uniformes. Des tentatives
varices out probablement ete faites pour resoudre cette question, en cher-
cliant a realiser cette expression par des transcendantes n'ayant que des
poles a distance finie. De telles tentatives, on le salt aujourd'hui, ne
pouvaient reussir, car on pent etablir que, entre deux fonctions uniformes
dans le voisinage d'un point qui est pour chacune d'elles un point singulier
essentiel isole, ne pent exister une relation algebrique de genre superieur
a I'unite. Les transcendantes a employer sont d'une nature beaucoup
plus compliquee ; les unes out un cercle comme coupure au dela duquel
elles ne peuvent etre prolongees analytiquement, les autres sont definies
dans tout le plan, mais elles ont sur un cercle une infinite de points singu-
liers essentiels formant, d'apres la denomination de M. Cantor, un ensem-
ble parfait qui n'est pas continu. Les celebres memoires de M. Poincare
sur les fonctions fuchsiennes et les belles recherches de M. Klein sur le
meme sujet ferment un des plus beaux chapitres ecrits dans ces vingt
dernieres annees sur la theorie des fonctions. Les fonctions automorphes
ferment une generalisation extremement etendue et remarquable des fonc-
tions modulaires etudiees par M. Hermite dans la theorie des fonctions
elliptiques, et des fonctions considerees par M. Schwarz en faisant dans
certains cas I'inversion du rapport de deux solutions de I'equation hyper-
geometrique. Toute cette theorie est d'ailleurs etroitement liee a la
252 Emile Picarcl :
theorie des equations lineaires, et c'est un des resultats les plus saillants
obtenus par M. Poincare qu'avec des transcendantes analogues aux fonc-
tions fuchsiennes on puisse integrer les equations differentielles lineaires
a coefficients algebriques n'ayant que des points singuliers reguliers (au
sens de M. Fuchs).
Parmi les transcendantes se rattachant aux fonctions algebriques
citons encore les integrales de fonctions a multiplicateurs etudiees tout
particulierement par M. Appell. Ce sont des fonctions n'ayant sur la
surface de Riemann que des poles ou des points singuliers logarithmiques,
et dont toutes les determinations se deduisent de I'une d'entre elles par
des substitutions de la forme (ti, au + h^; elles generalisent par suite les
integrales abeliennes pour lesquelles les a sont egaux a I'unite. Un beau
resultat obtenu par M. Appell est que ces fonctions se presentent dans la
recherche des coefficients des fonctions abeliennes de deux variables quand
on les developpe en series trigonometriques. On a aussi recherche les cas
ou I'inversion d'une integrale de fonction a multiplicateurs conduit a une
fonction uniforme, mais la conclusion a ete negative, c'est a dire que dans
ce cas la courbe algebrique est necessairement du genre zero ou du genre
un, et la fonction uniforme obtenue se ramene ou des transcendantes
connues.
IV.
Les equations differentielles forment une mine inepuisable pour ob-
tenir des fonctions speciales. Les equations lineaires out ainsi conduit a
des fonctions jouissant de proprietes bien definies. Pour les equations
non lineaires, M. Fuchs appela le premier I'attention sur les equations
algebriques du premier ordre a points critiques fixes et montra comment
on pent reconnaitre qu'on se trouve dans ce cas. M. Poincare fit voir
ensuite qu'on pouvait ramener ce cas a des quadratures ou aux equations
de Riccati. M. Painleve a etendu ces resultats en considerant les equa-
tions du premier ordre dont les integrales n'ont qu'un nombre limite de
valeurs autour de I'ensemble des points critiques mobiles. Une des con-
clusions de ses recherches est que I'integrale, supposee trauscendante, de
toute equation algebrique du premier ordre qui satisfait a la condition
precedente, est une fonction algebrique de I'integrale d'une equation de
Riccati dont les coefficients dependent algebriquement de ceux de I'equa-
tion donnee. On peut se proposer des problemes analogues pour les
equations differentielles algebriques d'ordre superieur au premier. II se
presente ici des difficultes considerables; I'une d'elles tient au fait suivant :
Troisieme Conference. 253
tandis que toute transformation biuniforme d'une courbe algebrique en
elle-meme (avec singularites isolees) est necessairement birationnelle, il
pent arriver au contraire qu'une transformation biuniforme d'une surface
algebrique en elle-raeme ne soit pas birationnelle. Une seconde difficulte,
non moins grave, consiste dans I'existence possible de singularites essen-
tielles mobiles. J'ai indique hier la distinction faite a cet egard par M.
Painleve entre la classe generale d'equations ne possedant pas de tels
points et la classe singuliere.
En cherchant a etendre aux equations du second ordre a points
critiques fixes la metliode qui avait reussi a M. Poincare pour les equa-
tions du premier ordre jouissant de la meme propriete, on est arrete imme-
diatement par la premiere difficulte signalee plus haut, et c'est seulement
dans le cas ou I'integrale generale de I'equation est supposee dependre
algebriquement des deux constantes d'integration que Ton pent pour-
suivre I'etude sans de serieuses difficultes ; on retombe d'ailleurs sur des
transcendantes deja connues. M. Painleve a fait une etude complete des
autres cas qui peuvent se presenter ; I'integrale generale peut encore etre
une fonction algebrique d'une seule des constantes, ou enfin dependre
d'une maniere transcendante des deux constantes (de quelque fagon qu'on
les choisisse). Ce dernier cas seul est irreductible aux transcendantes
classiques, c'est a dire ne peut etre ramene aux quadratures et aux equa-
tions lineaires. Ce cas se presente d'ailleurs effectivement, et M. Pain-
leve a forme explicitement toutes les equations du second ordre de la
forme
y" = Riy^ y\ ^}
ou B est rationnel en ?/', algebrique en y et analytique en x ; elles se
laissent ramener a douze types canoniques tres simples. J'indiquerai
seulement deux de ces equations pour lesquelles I'integrale generale est
uniforme,
1/" =z Qy^ -\- X
y" = 2y^ -{■ xy + a (a = constante numerique)
L'integrale generale de I'une et I'autre equation est une fonction uni-
forme et meromorphe de x dans tout le plan, et cette integrale est une
transcendante vraiment nouvelle. Ces exemples precis montrent com-
bien M. Painleve a pousse jusqu'au bout ses profondes recherches.
Je me bornerai a dire, relativement aux equations du troisieme ordre,
que I'integrale generale peut avoir des lignes de points singuliers essen-
254 Emile Picard:
tiels. On en a facilement des exemples en considerant I'equation diffe-
rentielle algebrique du troisieme ordre a laquelle satisfait une fonction
automorphe d'une variable.
Le champ des fonctions speciales de plusieurs variables complexes,
dont I'etude a ete quel que peu approfondie, est assez limite. La theorie
des fonctions abeliennes a fait Tobjet d'un nombre considerable de tra-
vaux qui sont trop classiques pour que je m'y arrete ici ; les memoires
de Riemann et de Weierstrass, les etudes de M. Hermite sur la transfor-
mation des fonctions abeliennes sont dans toutes les memoires. Apres
les etudes faites sur les fonctions fuchsiennes d'une variable, il etait
naturel de chercher des transcendantes analogues pour le cas de deux
variables ; on devait d'abord se demander s'il existe des groupes discon-
tinus contenus dans le groupe lineaire a deux variables
/ a'u + h'v + c a"u -\-h"v + c"\ .. .
(w, v; — - — — , — ■ I. {1)
\ au + ov + c au + bv -\- e J
Un seul exemple d'un tel groupe, mais bien peu utile, s'offrait a
I'esprit, celui du groupe a quatre periodes. Aucun exemple analogue
au groupe modulaire ne se presentait, et il n'y avait rien a demander
sur ce point a la theorie des fonctions abeliennes, au moins sous sa forme
classique. Par quoi d'ailleurs se trouverait remplacee ici la condition
imposee aux substitutions d'un groupe fuchsien, de conserver un certain
cercle ? L'etude des formes quadratiques ternaires a indeterminees con-
juguees vint permettre de former en grand nombre les exemples cher-
chees. M. Hermite avait, il y a longtemps, montre I'interet au point
de vue arithmetique des formes quadratiques binaires a indeterminees
conjuguees ; les formes ternaires indefinies conduisirent a de nombreux
groupes du type (1), discontinus a I'interieur d'une certaine hypersurface
de I'espace a quatre dimensions. Cette surface remplace la circonference
de la theorie des groupes fuchsiens. Les groupes du type precedent
furent appelees groupes hyperfuchsiens ; on se rend aisement compte que
leur recherche generale constitue, comme pour les groupes fuchsiens, un
probleme uniquement d'ordre algebrique ; mais, toute representation
geometrique faisant defaut, cette recherche directe serait tellement
penible qu'elle est reellement impraticable. Aussi les exemples fournis
par des considerations arithmetiques sont-ils extremement precieux.
Troisieme Conference. 255
Aux groupes hyperfuchsiens correspondent des fonctions uniformes
restant invariables par les substitutions du groupe.
Des exemples de fonctions hyperfuchsiennes d'une nature differente
peuvent etre fournis par les series hypergeometriques de deux variables.
Una telle serie, fonction de a; et 3/ dependant de quatre parametres arbi-
traires X, yu., hy, et h,^ satisfait a un systeme de trois equations lineaires aux
derivees partielles du second ordre, ayant trois solutions communes
lineairement independantes. Designant celles-ci par Wj, Og, 6)3, on peut
cliercher dans quels cas les quotients
donnent pour x et y des fonctions uniformes de u et v. Les conditions
sont tres simples ; si on prend deux quelconques des quatre quantites
\, /A, 5j et ^2? soit, par exemple \ et 5^, la difference X + 6j — 1 doit etre
I'inverse d'un nombre entier positif, et pareillement si on prend trois
quelconques de ces quantites, soit X, n et h^ la difference 2 — X — /x — 5j
est encore egal a I'inverse d'un entier positif. Je citerai I'exemple
\z= ix = h-^ = h^ = ^ pour lequel le polyedre f ondamental du groupe est
tout entier a Vinterieur de I'hypersurface limite.
On peut generaliser les fonctions fuchsiennes en considerant d'autres
groupes discontinus que les groupes hyperfuchsiens. Une substitution
birationnelle entre deux variables u Qt v n'est pas necessairement lineaire,
et ce serait un probleme interessant mais difficile de former tous les
groupes discontinus au moins dans une certaine region de I'hyperespace
(w, V) de substitutions birationnelles. En dehors des groupes lineaires
(hyperfuchsiens) on a seulement considere jusqu'ici les groupes formes
de substitutions de la forme
/ au-^h \ ( a'v -\-h' \
r'^^TM/ V c'v + d'J
et des substitutions ou u est remplace par une fonction lineaire de v et
inversement. Ce sont les groupes hyperabSliens qui rentrent evidemment
dans les types des substitutions quadratiques ; il y a dans ce cas deux
domaines frontieres. II y aura sans doute des decouvertes interessantes
a faire un jour dans le champ tres vaste des groupes discontinus de sub-
stitutions birationnelles, et des fonctions correspondantes (dans le cas
ou il en existera, comme il arrive pour les fonctions hyperfuchsiennes
et hyperabeliennes).
256 Emile Picard:
VI.
Nous avons rappele tout a I'heure le brillant d^veloppement de la
theorie des fonctions algebriques d'une variable ; les progres ont ete
beaucoup plus lents dans le champ de deux variables. C'est un sujet
en pleine elaboration, et que Ton attaque de plusieurs cotes. Clebsch,
se plagant au point de vue de la geometric analytique, signala le premier
que, pour une surface algebrique de degre m, certaines surfaces d'ordre
w — 4 devaient jouer le role que jouaient les adjointes d'ordre m — 3 par
rapport a une courbe de degre m. L'etude de ces surfaces d'ordre tw — 4
a ete reprise par M. Noether dans un memoire de grande importance.
En se plaQant au point de vue de la theorie des fonctions, voici I'origine
de ces surfaces. Si on cherche les integrales doubles
J J R(x, y, z)dx dy (J(x, y, z) = 0)
restant toujours finies, integrales qu'on appelle les integrales doubles
de premiere espece, on trouve qu'elles sont de la forme
//
Q(x, y, z)dxdy
Q etant un polynome d'ordre w — 4. Le nombre pg de ces polynomes
lineairement independants est ce que I'on appelle le genre gSomStrique
de la surface ; un pareil nombre est manifestement un invariant. Jus-
qu'ici les analogies sont completes avec les courbes ; il y a des integrales
doubles de premiere espece, comme il y a des integrales abeliennes de
premiere espece. Mais une premiere difference va de suite se manifester.
II faut calculer le nombre des arbitraires qui figurent dans les poly-
nomes Q d'ordre w — 4 se comportant aux points multiples de la sur-
face de telle maniere que I'integrale reste finie. Or on pent trouver par
une formule precise le nombre des conditions ainsi entrainees, mais seule-
ment pour un polynome d'un ordre suffisamment grand N; si done on
fait dans cette formule iV = m — 4, il est possible que Ton trouve un
nombre different de pg ; on designe le nombre que donne la formule a
laquelle je fais allusion par j9„, et on I'appelle le genre numerique de
la surface. Le cas le plus general est celui ou Pn=Pgl quand il n'y
a pas egalite, on a Pn etant certainement nuls a partir d'une valeur assez grande
de r. La formule precedente est fondamentale dans I'etude du genre
numerique.
Nous avons parle plus haut des integrales doubles de premiere espece
relatives a une surface. On peut aussi developper une theorie des inte-
grales doubles de seconds espece dont la definition est la suivante: ce sont
les integrales qui deviennent infinies comme
//i
(f.gT)..., (.)
U et V etant des fonctions rationnelles de x, i/ et z [/(ic, y, 2) = 0] . Le
nombre des integrales distinctes de seconde espece, c'est a dire des
integrales dont aucune combinaison lineaire n'est de la forme (a) est
fini ; c'est un invariant de la surface. Mais il n'en est plus ici, comme
dans le cas des courbes pour lesquelles le nombre des integrales abe-
liennes distinctes de seconde espece etait egale k 2p; le nouvel invariant
258 Emile Picard:
d'une classe de surfaces algebriques n'est pas lie au genre, soit geome-
trique soit numerique.
La consideration des integrales doubles ne se presente pas seule. On
pent aussi envisager des integrales de differentielles totales de la forme
j^P (x, y, z)dx+Q (x, y, z) dy
ou P et ^ sont rationnelles en x, y et 2, et il y a encore lieu de parler des
integrales de premiere et de seconde espece. Mais ici de telles integrales
n'existent pas en general, c'est a dire pour une surface prise arbitraire-
ment, et c'est une question assez delicate que de reconnaitre si une surface
possede des integrales de seconde espece en dehors des fonctions ration-
nelles.
Les questions de connexite presentent aussi un grand interet dans la
theorie des fonctions algebriques de deux variables independantes, mais
quelques precautions sont ici necessaires. Pour une surface determinee,
et en procedant d'une maniere bien precisee, on pent obtenir deux nombres
correspondant a la connexion lineaire et a la connexion a deux dimen-
sions ; le premier p^ est veritablement un invariant pour toute transfor-
mation birationnelle, tandis que le second p^ pent etre influence par la
presence de points fondamentaux dans la correspondance birationnelle.
C'est un resultat remarquable que le nombre j^i — 1 represente le nombre
des integrales de differentielles totales distinctes de seconde espece rela-
tives a la surface. Pour une surface arbitrairement choisie, il n'y a pas
d'integrale de seconde espece et on o. p^ = 1.
On voit que les points de vue de la geometric analytique, de la theorie
des fonctions et de la geometric de situation se retrouvent aussi dans
I'etude des surfaces algebriques, mais il faut se mefier des analogies avec
la theorie des courbes. Tout, dans ce nouveau domaine, se presente
d'une maniere plus compliquee.
Voici encore un exemple de cette complexite. Les courbes dont le
genre est nul forment la classe tres restreinte des courbes unicursales.
Au contraire les surfaces pour les quelles jt?^ = sont extremement varices,
et on pent dans ce cas considerer un nouvel invariant que M. Enriques a
decouvert et qu'il appelle le higenre. On pent le definir aisement dans le
cas ou la surface / de degre m n'a qu'une ligne double. On envisagera a
cet effet le systeme des surfaces d'ordre 2 w — 8 (ne se composant pas de
/ et d'une surface d'ordre w — 8) ayant comme ligne double la courbe
Troisieme Conference. 259
double de /; le bigenre P est la dimension augmentee d'une unite de ce
systeme. Cette notion a permis a M. Castelnuovo d'etablir un theoreme
reellement merveilleux ; il s'agit des conditions necessaires et suffisantes
pour qu'une surface soit unicursale. On pouvait penser que ces con-
ditions seraient tres compliquees et non susceptibles d'une forme simple ;
il n'en est rien, elles se reduisent a j9„ = 0, P = 0. Mais je dois m'arreter,
me bornant a citer seulement le memoire si elegant de M. Humbert sur
les surfaces hyperelliptiques qui donnent un tres interessant exemple de
surfaces irregulieres pour les quelles p„ = — 1, tandis que pg=l.
Nous avons, messieurs, jete un rapide coup d'oeil sur quelques unes
des branches de la science mathematique. Vous avez pu vous apercevoir
plus d'une fois de I'embarras dans lequel je me suis trouve, quand j'ai
voulu, pour les necessites de mon exposition, faire une classification dans
certaines theories. La penetration reciproque des diverses disciplines est
aujourd'hui en effet un fait capital et sera de plus en plus la source d'im-
portantes decouvertes. A cet egard, il y a une grande difference entre
notre epoque et des temps un peu anterieurs. Nous avons peine aujour-
d'hui a comprendre certaines histoires ou on voit des geometres mepriser
des analystes et inversement ; nous sentons que I'ere des ecoles fermees et
etroitement attachees a un seul point de vue est pour toujours terminee.
II est bien vraisemblable que I'erudition jouera a I'avenir un plus grand
role qu'autrefois en mathematiques. Les mathematiciens perdront peut-
etre ce privilege de la precocite qui etonne tant de personnes ; ils se
rapprocheront des physiciens et des naturalistes qui doivent en general
commencer plus tard leurs travaux personnels. En terminant, je me
permettrai de donner un conseil aux etudiants mathematiciens qui m'ont
fait I'honneur de m'ecouter ; je leur recommanderai de ne pas se can-
tonner trop tot dans des recherches speciales. II leur faut acquerir
d'abord des vues generales sur les diverses parties de notre science, sans
lesquelles leurs efforts risqueraient de rester steriles, et qui leur coiite-
raient plus tard un bien plus grand effort.
.-£^.£4^^-
tJBER DIE GRUNDPRINCIPIEN UND GRUND-
GLEICHUNGEN DER MECHANIK.
Von Professor Ludwig Boltzmann.
Ekste Vorlestjng.
Die analytische Mechanik ist eine Wissenschaft, welche schon von
ihrem Begriinder Newton mit solchem Scharfsinne und soldier Vollen-
dung ausgearbeitet wurde wie es in dem gesaramten Gebiete menschlichen
Wissens fast ohne Beispiel dasteht. Die grossen Meister, welche auf
Newton folgten, haben das von ihm errichtete Gebaude noch weiter
gefestigt, und es hatte den Anschein, dass eine vollendetere und einheit-
lichere Schopfung des Menschengeistes als die Grundlehren der Me-
chanik, wie sie uns in den Werken von Lagrange, Laplace, Poisson,
Hamilton etc. entgegentreten iiberhaupt nicht denkbar ware. Gerade
die Begriindung der ersten Principien schien von diesen Forschern
mit einem Scharfsinne und einer logischen Consequenz durchgefiihrt, die
allezeit das Vorbild lieferten, welchem man die Begriindung der iibrigen
Wissenszweige, wenn auch nicht immer mit dem gleichen Erfolge, nach-
zubilden suchte, Es schien lange ganz unmoglich dieser Begriindung
iiberhaupt noch etwas hinzu zu fiigen oder daran etwas zu andern.
Um so auffallender und unerwarteter ist es, dass gegenwartig haupt-
sachlich in Deutschland ziemlich lebhafte Controversen gerade iiber die
Grundprincipien der analytischen Mechanik entstanden sind. Es ist
dies gewiss nicht so zu verstehen, als ob die Ehrfurcht und Bewunde-
rung, die wir dem Genius eines Newton, Lagrange oder Laplace zollen,
dadurch irgend wie geschmalert werden sollte. Diese haben aus den
kleinen Anfangen, welche sie vorfanden, eine fiir alle Zeiten mustergiil-
tige Herrin geschaffen. Sie hatten so viel des thatsachlich Neuen heraus
zu arbeiten, dass sie sich nur aufgehalten und dem einheitlichen Ein-
druck geschadet hatten, wenn sie bei gewissen Schwierigkeiten und
Dunkelheiten zu lange verweilt hatten. Aber seitdem ist unsere Kennt-
261
262 Ludwig Boltzmann:
nis von Thatsachen bedeutend gewachsen, unser Verstand ist geschult,
so dass viele Vorstellungen, welclie zu Zeiten Newtons noch den Gelehr-
ten Schwierigkeiten machten, nun zum Gemeingut aller geworden sind.
Dadurch erhielt man Musse die Construktion des Newton'schen Gebaudes
gewissermassen mit der Lupe zu betrachten, und siehe es ergaben sich
manche Schwierigkeiten, wie sie sich ja dem Menschengeiste immer
gerade da am meisten entgegen stellen, wo er die einfachsten Grund-
lagen der Erkenntnis zu analy siren strebt.
Diese Schwierigkeiten sind f reilich mehr philosophischer oder wie man
heutzutage sagt, erkenntnistheoretischer Natur. Wir Deutsche sind
schon oft und viel verlacht worden wegen unserer Neigung zur philoso-
phischen Speculation und in friiherer Zeit sicher oft mit Recht. Eine von
den Thatsachen abgekehrte Philosophic hat nie etwas Brauchbares hervor-
gebracht und kann es nicht hervorbringen. Von unmittelbar greifbarem
Nutzen ist es vor allem, unsere Kenntnis der Thatsachen durch Experi-
mente zu erweitern und auch unsere wissenschaf tliche Naturkenntnis wird
zunachst und am ausgiebigsten in dieser Weise gefordert. Aber trotz
alledem scheint die Neigung die einfachsten Begriffe zu analysiren und
sich iiber die Grundoperationen unseres Denkens Rechenschaft zu geben
im Menschengeiste unbezwinglich.
Viel hat sich auch die Methode dieser Analyse im Verlauf e der Zeit ver-
vollkommnet, so dass dieselbe heutzutage weun auch noch keineswegs sof ort
praktisch fruchtbringend, doch lange nicht mehr so wesenlos ist, wie die
alte Philosophic. Im Verlaufe der Geschichte erfahrt ja das ganze Cultur-
bild der Menschheit stete und bedeutende Schwankungen. Die Deutschen
sind nicht mehr die unpraktischen Traumer von ehemals. Sie haben es
auf alien Gebieten der Experimentalwissenschaft, der Technik, Industrie,
und Politik bewiesen. Die Bestrebungen der Amerikaner waren natur-
gemass anfangs behufs Unterjochung des Grundes und Bodens der rein
praktischen Thatigkeit der Industrie und Technik zugewandt. Aber
sie sind es langst nicht mehr ausschliesslich und schon weist Amerika auf
alien Gebieten der abstrakten Wissenschaft Forscher auf, die den hervor-
ragensten Europas voUkommen ebenburtig zur Seite stehen. Da sie daher,
meine Herren, einen Deutschen zu Vortragen in ihrem Lande geladen
haben, so will ich es wagen ein Gebiet der Erkenntnistheorie mit ihnen
zu betreten.
Ich will zunachst wieder zuriick kommen auf die Bedenken, welche
gegen die Fundamente der Newton'schen Mechanik erhoben worden sind
Erste Vorlesung. 263
oder (besser gesagt) zu den Stellen, wo diese noch einer naheren Beleucht-
ung, einer Analyse der Schlussweise und Sichtung der Begriffe zu bediir-
fen scheinen. Bei Aufstellung der Bewegungsgesetze betrachtet Newton
die Bewegung der Korper als eine absolute im Raume. Der absolute
Raum ist aber nirgends unserer Erfahrung zuganglich. Erfahrungsmas-
sig gegeben sind immer nur die relativen Lagenanderungen der Korper.
Es wird also da gleich zu Anfang voUstandig iiber die Erfahrung hin-
ausgegangen, was gewiss bedenklicb ist in einer Wissenscliaft, welche
sich nur die Aufgabe stellt Erfahrungsthatsachen darzustellen. Diese
Schwierigkeit ist natiirlich dem Genius Newtons keineswegs entgangen.
Allein dieser glaubte ohne den Begriff eines absoluten Raumes zu keiner
einfacben Formulirung des Tragheitsgesetzes gelangen zu konnen, um
die es ibm an erster S telle zu thun war und ich glaube, dass er hierin auch
Recht behalten hat ; denn so viel diese Schwierigkeit auch beleuchtet oder
durchdacht wurde, so ist doch kaum ein wesentlicher Fortschritt erzielt
worden. Neumann fiihrt statt des Newton'schen absoluten Raumes einen
rathselhaften idealen Bezugskorper ein, womit er offenbar ganz ebenso
wie Newton iiber die Erfahrung hinausgeht. Streintz stellt sich die
Aufgabe derartige Begriffe oder Korper zu vermeiden, indem er lehrt
wie man mittelst der Bewegung eines Gyroskops, auf welches keine oder
bekannte Krafte wirken relativ gegen ein gewahltes Coordinatensystem
entscheiden kann, ob fiir dieses Coordinatensystem die Newton'schen Be-
wegungsgesetze gelten, ob es ein brauchbares Bezugssystem ist. Allein
diese Streintz'schen Betrachtungen scheinen fiir die Fundamentirung der
Mechanik wenig brauchbar, da sie ja bereits die Bewegungsgesetze ein-
es rotirenden Kreisels und die Beurtheilung, ob auf denselben Krafte
wirken oder nicht, voraussetzen, wozu schon die Kenntnis der Newton'-
schen Bewegungsgesetze erforderlich ist. Lange versucht allerdings
die Formulirung des Tragheitsgesetzes ohne irgend ein Bezugssystem
bloss durch Betrachtung der relativen Bewegung. Sie gelingt ihm auch,
fallt aber so complicirt und weitschweifig aus, dass man sich nur schwer
entschliessen wird ein so wenig libersichtliches Gesetz an Stelle der ein-
facben Newton'schen Formel zu setzen. Selbstverstandlich geht auch
der Vorschlag Mach's Gerade, welche durch die Gesammtheit aller Mas-
sen der Welt bestimmt sind oder der Vorschlag den Lichtather an Stelle
des absoluten Raums zu setzen, beide freilich in ganz anderer Weise iiber
die Erfahrung hinaus. Ersterer Vorschlag kniipft namlich wieder an
rein ideale transcendente Begriffe an, wogegen letzterer eine Aussage
264 lAidwig Boltzmann:
macht, welche zwar erfahrungsmassig moglicherweise bewiesen werden
konnte, aber es gewiss noch nicht ist. Es miisste derm fiir den Ather
eine ganz audere Mechanik gelten, dieser miisste etwa selbst die Ursache
des Tragheitsgesetzes nicht aber demselben unterworfen sein. Eine
gleiche Schwierigkeit begegnet man bei Einfiihrung des Begriffs der
Zeit. Auch diese wird von Newton als eine absolute eingefiihrt, wahrend
uns eine solche niemals gegeben ist, sondern immer bloss die Gleicbzei-
tigkeit des Verlaufs mehrerer Vorgange. Jedoch ist bier die Abhilfe
leichter, indem man von einem Vorgange ausgeht, der sich immer peri-
odisch unter ganz gleichen Umstanden wiederholt. Freilich ist es nicht
moglich absolute Gleichheit der Umstande herzustellen, doch kann man
im hochsten Grade wahrscheinlich machen, dass alle Umstande, die iiber-
haupt wesentlichen Einfluss haben, die gleichen sind. Man kann dies
noch dadurch erharten, dass man verschiedenartige Vorgange von dieser
Eigenschaft (die Erddrehung, die Schwingungen eines Pendels, einer
Chronometerfeder) untereinander vergleicht. Die Ubereinstimmung aller
dieser Vorgange in der Anzeige gleicher Zeiten schliesst dann jeden
Zweifel an der Brauchbarkeit der Methode aus.
Eine dritte Schwierigkeit betrifft die Begriffe der Masse und Kraft.
Dass die Newton'sche Definition der Masse als Quantitat der Materie
eine nichts sagende ist, wurde langst erkannt. Aber auch beziiglich des
Verhaltnisses der Kraft zur Masse ergeben sich Zweifel. Ist die Masse
das allein Existirende und die Kraft nur eine Eigenschaft derselben oder
ist umgekehrt die Kraft das wahrhaft Existirende oder ist ein Dualismus
zweier getrennter Existenzen (Masse und Kraft) anzunehmen, so dass die
Kraft eine von der Materie getreunt existirende Ursache der Bewegung
der ersteren ist. Hinzu kam in neuerer Zeit noch die Frage, ob auch
der Energie Existenz zuzuschreiben ist oder ob gar letztere das allein
Existirende ist.
Es war vor alien Kirchhoff, welcher in diesem Punkte schon der Art
der Fragestellung entgegentrat. Oft ist ein Problem schon halb gelost,
wenn die richtige Methode der Fragestellung gefunden ist. Kirchhoff
wies es nun zuriick, dass es Aufgabe der Naturwissenschaft sei, das wahre
Wesen der Erscheinungen zu entriithseln und ihre ersten metaphysischen
Grundursachen anzugeben. Er reducirte die Aufgabe der Naturwissen-
schaft vielmehr darauf, die Erscheinungen zu beschreiben. Kirchhoff
nannte dies noch eine Beschrankung der Aufgabe der Naturwissenschaft.
Wenn man aber so recht in die Art und Weise, ich mochte sagen in den
Erste Vorlesung. 265
Mechanismus unseres Denkens eindringt, so moclite man fast auch das
leugnen.
Alle unsere Vorstellungen und Begriffe sind ja nur innere Gedanken-
bilder, wenn ausgesprochen Lautcombinationen. Die Aufgabe unseres
Denkens ist es nun, dieselben so zu gebrauclien und zu verbinden, dass
wir mit ihrer Hilfe allezeit mit grosster Leichtigkeit die richtigen Hand-
lungen treffen und audi andere zu richtigen Handlungen anleiten. Die
Metaphysik hat sich da dem niichternsten praktischsten Standpunkte
angeschlossen, die Extreme beriihren sich. Die begrifflichen Zeichen,
welche wir bilden, haben also nur eine Existenz in uns, die aussern
Erscheinungen konnen wir nicht mit dem Masse unserer Vorstellungen
messen. Wir konnen also formell derartige Fragen aufwerfen, ob bloss
die Materie existirt und die Kraft eine Eigenschaft derselben ist oder
ob letztere von der Materie unabhangig existirt oder ob umgekehrt die
Materie ein Erzeugnis der Kraft ist ; aber es haben alle diese Fragen gar
keine Bedeutung, da alle diese Begriffe nur Gedankenbilder sind, welche
den Zweck haben die Erscheinungen richtig darzustellen. Besonders
klar hat dies Hertz in seinem beriihmten Buche uber die Principien der
Mechanik ausgesprochen, nur stellt Hertz daselbst als erste Forderung
die auf, dass die Bilder, welche wir uns construiren, den Denkgesetzen
entsprechen miissen. Gegen diese Forderung mochte ich gewisse Beden-
ken erheben oder wenigstens sie etwas naher erlautern, Gewiss miissen
wir einen reichen Schatz von Denkgesetzen mitbringen. Ohne sie ware
die Erfahrung vollkommen nutzlos; wir konnten sie gar nicht durch
innere Bilder fixiren. Diese Denkgesetze sind uns fast ausnahmslos ange-
boren, aber sie erleiden doch durch Erziehung, Belehrung, und eigene
Erfahrung Modifikationen. Sie sind nicht vollkommen gleich beim
Kinde, beim einfachen ungebildeten Manne, oder beim Gelehrten. Wir
werden dies auch einsehen, wenn wir die Denkrichtung eines naiven Volkes
wie der Griechen mit der der Scholastiker des Mittelalters, und diese wieder
mit der heutigen vergleichen. Gewiss gibt es Denkgesetze, welche sich
so ausnahmslos bewahrt haben, dass wir ihnen unbedingt vertrauen, sie
fiir aprioristische unabanderliche Denkprincipien halten. Aber ich
glaube doch, dass sie sich erst langsam entwickelten. Ihre erste Quelle
waren primitive Erfahrungen der Menschheit im Urzustand, allmiilig
erstarkten sie und verdeutlichten sich durch complicirtirte Erfahrungen
bis sie endlich ihre jetzige scharfe Formulirung annahmen ; aber als unbe-
dingt oberste Richter mochte ich die Denkgesetze nicht anerkennen.
266 Ludwig Boltzmann:
Wir konnen nicht wissen ob sie nicht doch noch die eine oder andere
Modification erfahren werden. Man erinnere sich doch mit welcher
Sicherheit Kinder oder Ungebildete iiberzeugt sind, dass man durch das
blosse Gefiihl die Richtung nach oben von der nach unten an alien Orten
des Weltraums miisse unterscheiden konnen und wie sie daraus die
Unmoglichkeit der Antipoden deduciren zu konnen glauben. Wiirden
solche Leute Logik schreiben, so wiirden sie das sicher fiir ein a priori
evidentes Denkgesetz halten. Ebenso wurden anfangs gegen die Coper-
nicanische Theorie vielfach aprioristische Bedenken erhoben und die Ge-
schichte der Wissenschaft weist zahlreiche Falle auf, wo man Siitze bald
begriindete, bald widerlegte mittels Beweisgriinden, die man damals fiir
evidente Denkgesetze hielt, wahrend wir jetzt von ilirer Nichtigkeit iiber-
zeugt sind. Ich moclite daher die Hertz'sche Forderung dahin modificiren,
dass in so weit wir Denkgesetze besitzen, welche wir durch stete Bewahr-
heitung in der Erfahrung als zweifellos richtig erkannt haben, wir die
Richtigkeit unserer Bilder zunachst an diesen erproben konnen, dass
aber die letzte und alleinige Entscheidung iiber die Zweckmassigkeit der
Bilder in dem Umstande liegt, dass sie die Erfahrung moglichst einfach
und durchaus treffend darstellen und dass gerade hierin wieder die Probe
fiir die Richtigkeit der Denkgesetze liegt. Haben wir die Aufgabe des
Denkens iiberhaupt und der Wissenschaft insbesondere in dieser Weise
erfasst, so ergeben sich uns Consequenzen welche im ersten Augenblick
etwas Frappirendes an sich haben. Eine Vorstellung von der Natur wer-
den wir falsch nennen, wenn sie uns gewisse Thatsachen unrichtich dar-
stellt oder wenn es offenbar einfachere gibt, welche die Thatsachen klarer
darstellen, besonders wenn sie allgemein bewahrten Denkgesetzen wider-
spricht, doch sind immerhin Theorien moglich, Avelche eine grosse Zahl von
Thatsachen richtig darstellen in andern Punkteu aber unrichtig sind, denen
also eine gewisse relative Wahrheit zukommt. Ja es ist sogar moglich, dass
wir in verschiedener Weise ein System von Bildern der Erscheinungen
construiren konnen. Jedes dieser Systeme ist nicht gleich einfach, stellt
die Erscheinungen nicht gleich gut dar. Aber es kann zweifelhaft,
gewissermassen Geschmacksache sein, welches wir fiir das Einfachere
halten, durch welche Darstellung der Erscheinungen wir uns mehr befrie-
digt fiihlen. Die Wissenschaft verliert hiedurch ihr einheitliches Geprage.
Man hielt doch ehedem daran fest, dass es nur Eine Wahrheit geben
konne, dass die Irrthiimer mannigfaltig seien, die Wahrheit aber nur eine
einzige ist. Dieser Ansicht muss von unserem jetzigen Standpunkte ent-
Erste Vorlesung. 267
gegen getreten werden, freilich ist der Unterschied der neuen Ansicht
gegeniiber der alten ein mehr formeller. Es war nie zweifelhaft, dass der
Mensch niemals den voUen Inbegriff aller Wahrheit zu erkennen vermoge.
Diese Erkenntniss ist nur ein Ideal. Ein ahnliches Ideal besitzen wir aber
audi gemass unserer jetzigen Vorstellung. Es ist das vollkommenste Bild,
das alle Erscheinungen in der einfachsten und zweckmassigsten Weise
darstellt. Wir wenden daher nach der einen Anschauungsweise den
Blick mehr auf das unerreichbare Ideal, welches nur ein einheitliches ist,
nach der andern auf die Mannigfaltigkeit des Erreichbaren.
Wenn wir nun die Uberzeugung haben, dass die Wissenschaft bloss
ein inneres Bild, eine gedankliche Construction ist, welche sich mit
der Mannigfaltigkeit der Erscheinungen niemals decken, sondern nur
gewisse Theile derselben ubersichtlich darstellen kann, wie werden wir
zu einem solchen Bilde gelangen ? wie es moglichst systematisch und
ubersichtlich darstellen konnen ? Es war friiher eine Methode beliebt,
welche der von Euclid in der Geometrie angewandten nachgebildet ist
und daher die Euclidische heissen soil. Dieselbe geht von moglichst
weuigen, moglichst evidenten Satzen aus. In den altesten Zeiten wurden
diese als a priori evident, als direkt dem Geiste gegeben betrachtet, wess-
halb man sie als Axiome bezeichnet. Spater dagegen schrieb man ihnen
lediglich den Charakter von hinlanglich verblirgten Erfahrungssatzen
zu. Aus diesen Axiomen wurden dann bloss mit Hilfe der Denkgesetze
gewisse Bilder als nothwendig deducirt und man glaubte so einen Beweis
gefunden zu haben, dass diese die einzig moglichen seien und nicht durch
andere ersetzt werden konnten. Als Beispiel fiihre ich die Schliisse an,
welche zur Ableitung des Krafteparallelogramms oder des Ampere'schen
Gesetzes oder des Beweises dienten, dass die zwischen zwei materiellen
Punkten wirkende Kraft in die Richtung ihrer Entfernung fallen und
eine Function dieser Entfernung sein miisse.
Aber die Beweiskraft dieser Schlussweise geriet allmalig in Miscredit,
der erste Schritt hiezu war der, dass man wie schon friiher geschildert
von einer a priori evidenten Grundlage zu einer bloss erfahrungsmassig
bewahrten liberging. Man sah ferner ein, dass auch die Deduktionen aus
jener Grundlage nicht ohne zahlreiche neue Hypothesen gemacht werden
konnten, und so wies endlich Hertz darauf hin, dass namentlich im Gebiete
der Physik unsere Uberzeugung von der Richtigkeit einer allgemeinen
Theorie im Wesen noch nicht auf der Ableitung derselben nach der
Euclidischen Methode, sondern vielmehr darauf beruhe, dass diese Theo-
268 Ludwig Boltzmann:
rie in alien bisher bekannten Fallen uns zu riclitigen Schliissen in Bezug
auf die Erscheinungen leite. Er machte von dieser Ansicht zuerst in
seiner Darstellung der Maxwell'schen Grundgleichungen der Lehre von der
Elektricitat und dem Magnetisraus Gebrauch, indem er vorschlug sicli um
deren Ableitung aus gewissen Grundprincipien gar nicht zu bekiimmern,
sondern sie einfach an die Spitze zu stellen und die Rechtfertigung hie-
von darin zu suchen, dass man nachweisen konne dass sie hinterher iiber-
all mit der Erfahrung iibereinstimme ; denn diese bleibt docli scliliesslich
die einzige Richterin liber die Brauchbarkeit einer Theorie, deren Urtheil
inapellabel und unerschiitterlich ist. In der That wenn wir auf die Gegen-
stande naher eingehen, welche mit dem Gegenstande am meisten zusam-
menhangen, das Tragheitsgesetz, das Kriifteparallelogramm und die libri-
gen Fundamentalsatze der Mechanik, so werden wir die verschiedenen
Beweise, welche in alien Lehrblichern der Mechanik fiir jeden einzelnen
dieser Satze geliefert werden, bei weitem nicht so liberzeugend fiuden, als
die Thatsache, dass sich alle aus dem Inbegriffe aller dieser Satze gezo-
genen Consequenzen so ausgezeichnet in der Erfahrung bestatigt haben.
Die Wege, auf denen wir zu den Bildern gelangten, sind nicht selten die
verschiedensten und von den mannigfaltigsten Zufiillen abhangig.
Manche Bilder wurden im Verlauf von Jahrhunderten durch das Zu-
sammenwirken vieler Forscher erst allmiilig construirt, wie die der mecha-
nischen Warmetheorie. Manche wurden von einem einzigen, genialen For-
scher, aber oft wieder auf sehr verschlungenen Umwegen, gefunden und
erst dann von andern in die verschiedenartigste Beleuchtung geriickt,
wie die besprochene Maxwell'sche Theorie der Elektricitat und des
Magnetismus. Es wird nun eine Darstellungsweise geben, welche ganz
besondere Vorziige aber audi wieder ihre Mangel besitzt. Diese Dar-
stellungsweise besteht darin, dass wir eingedenk unserer Aufgabe, bloss
innere Vorstellungsbilder zu construiren, anfangs lediglich mit gedank-
lichen Abstractionen operiren. Hiebei nehmen wir noch gar keine Riicksicht
auf etwaige Erfahrungsthatsachen. Wir bemiihen uns lediglich mit mog-
lichster Klarheit unsere Gedankenbilder zu entwickeln, und aus denselben
alle moglichen Consequenzen zu ziehen. Erst hinterher, nachdem die
ganze Exposition des Bildes vollendet ist, priifen wir dessen Ubereinstim-
mung mit den Erfahrungsthatsachen, motiviren also in dieser Weise erst
hinterher, warum das Bild gerade so und nicht anders gewiihlt werden
musste, woriiber wir vorher nicht die leiseste Andeutung geben. Wir
wollen dies als die deduktive Darstellung bezeichnen. Die Vorziige dieser
Erste Vorlesimg, 269
Darstellung liegen auf der Hand. Sie lasst zunachst gar keinen Zweifel
dariiber aufkommen, dass sie nicht die Dinge an sich selbst bieten will,
sondern bloss ein inneres geistiges Bild und dass ihr Bestreben bloss
darin besteht dieses geistige Bild zu einer geschickten Bezeichnung der
Erscheinungen zu formen. Da die deduktive Methode nicht fortwahr-
end aussere uns aufgezwungene Erfahrungen mit inneren von uns will-
kiirlich gewahlten Bildern vermengt, so ist es ihr weitaus am leichtesten
diese letzteren klar und widerspruchsfrei zu entwickeln. Es ist namlich
eines der wichtigsten Erfordernisse dieser Bilder, dass sie vollkommen
klar sind, dass wir niemals in Verlegenheit sind, wie wir sie in jedem
bestimmten Falle formen sollen und dass wir jedes Mai das Resultat ein-
deutig und unzweifelhaft aus denselben ableiten konnen. Gerade diese
Klarheit leidet durch zu friihe Vermischung mit der Erfahrung und wird
bei der deduktiven Darstellungsweise am sichersten gewahret. Dagegen
tritt bei dieser Darstellungsweise besonders die Willkiirlichkeit der Bil-
der scharf hervor, indem man mit ganz willkiirlichen Gedankenconstruc-
tionen beginnt und deren Notwendigkeit nicht anfangs motivirt sondern
erst hinterher rechtfertigt. Davon, dass nicht auch andere Bilder erdacht
werden konnten, die ebenso mit der Erfahrung stimmen wlirden, wird
kein Schatten eines Beweises geliefert. Es scheint dies ein Fehler zu
sein, ist aber vielleicht gerade ein Vorzug, wenigstens fiir denjenigen,
der die friiher auseinandergesetzte Ansicht von dem Wesen jeder Theo-
rie hat. Ein wirklicher Fehler der deduktiven Methode besteht dagegen
darin, dass der Weg nicht sichtbar wird, auf welchem man zur Auffindung
des betreffenden Bildes gelangte. Aber es ist ja im Gebiete der Wissen-
schaftslehre die Kegel, dass der Zusammenhang der Schliisse dann am
deutlichsten hervortritt, wenn man diese moglichst in ihrer natlir-
lichen Reihenfolge und ohne Riicksicht auf den oft krummen Weg
auseinandersetzt, auf welchem dieselben gefunden wurden. Hertz
hat auch im Gebiete der Mechanik in seinem bereits citirten Buche
ein Muster einer solchen rein deduktiven Darstellung gegeben. Ich
glaube den Inhalt des Hertz'schen Buches hier als bekannt voraussetzen
zu konnen und mich daher auf eine ganz kurze Charakteristik des-
selben beschranken zu diirfen. Hertz geht von materiellen Punkten
aus, welche er als reine Gedankenbilder betrachtet. Auch die Masse
definirt er ganz unabhangig von aller Erfahrung durch eine Zahl, die
wir uns jedem materiellen Funkte beigelegt denken miissen, namlich die
Anzahl der einfachen Massenpunkte, welche er enthiilt. Aus diesen
270 Ludwig Boltzmann:
abstrakten Begriffen construirt er eine zuniiclist natiirlich Moss wie die
Punkte selbst in Gedanken vorhandene Bevvegung. Der Begriff der
Kraft fehlt dabei vollstiindig. An ilire Stelle treten gewisse Beding-
ungen, welche sicli in der Form von Gleichungen zwischen den Differen-
zialen der Coordinaten der materiellen Punkte schreiben. Diese letzteren
sind nun mit gegebenen Anfangsgeschwindigkeiten ausgestattet und
bewegen sich in jeder folgenden Zeit nach einem sehr einfachen Gesetze,
welches sobald die Bedingungsgleichungen gegeben sind, die Bewegung
fiir alle Zeiten eindeutig bestimmt. Hertz spriclit es dahin aus, dass die
Summe der mit den Massen multiplicirten Quadrate der Abweichungen
der materiellen Punkte von der geradlinigen, gleichformigen Bewegung
fiir jeden Zeitmoment ein Minimum sein muss oder noch kiirzer, dass
die Bewegung in den geradesten Bahnen gescliieht. Es hat dieses Gesetz
die grosste Ahnlichkeit mit dem Gauss'schen Principe des kleinsten
Zwanges, ja es ist gewissermassen derjenige spezielle Fall, der eintritt,
wenn man das Gauss'sche Princip auf ein System von Punkten anwen-
det, welche zwar einem Zwange, aber keinerlei sonstigen aussern Kraften
unterworfen sind.
Ich habe in meinem Buche welches den Titel hat " Vorlesungen iiber
die Principe der Mechanik" ebenfalls eine rein deduktive Darstellung der
Grundprincipe derselben versucht, aber in ganz anderer Weise, weit mehr
an die gewonliche Behandlung der Mechanik ankniipfend. Ich gehe wie
Hertz von reinen Gedankendiugen, exakten materiellen Punkten aus ; ich
beziehe deren Lage auf ein ebenfalls gedachtes rechtwinkliges Coordina-
tensystera und denke mir ein geistiges Bild von der Bewegung derselben
zunachst in folgender Weise construirt. Jedesmal, wenn sich zwei der-
selben in irgend einer Entfernung r befinden, soil jeder derselben eine
Beschleunigung in der Richtung von r erfahren, welche eine Function
/(r) dieser Entfernung ist, iiber die spiiter nach Belieben verfiigt wer-
den kann. Es soUen ferner die Beschleunigungen beider Punkte in
einem zu alien Zeiten unveranderlichen Zahlenverhaltnisse stehen,
welches das Massenverhaltnis der beiden materiellen Punkte definirt.
Wie wir uns die Bewegung aller materiellen Punkte zu denken haben,
das ist dann eindeutig durch die Angabe bestimmt, dass die wirkliche
Beschleunigung jedes Punktes die Vectorsumme aller fiir ihn nach der
friiheren Kegel gefundenen Beschleunigungen ist und sich zur schon vor-
handenen Geschwindigkeit des Punktes ebenfalls so addirt wie Vector-
grossen addirt werden. Woher diese Beschleunigungen kommen und
Erste Vorlesung. Til
warum ich gerade die Vorschrift gebe sich das Bild in dieser Weise zii
construiren wird nicht welter discutirt. Es geniigt dass das Bild ein voU-
kommen klares ist, welches in geniigend vielen Fallen durch Rechnungen
im Detail ausgearbeitet werden kann. Dasselbe findet seine Rechtfertig-
ung erst darin, dass sich die Function /(r) in alien Fallen so bestimmen
lasst, dass die gedachte Bewegung der eingebildeten materiellen Punkte
in ein naturgetreues Abbild der wirklichen Erscheinungen iibergetit.
Wir haben durch diese Behandlungsweise, welche wir die rein deduc-
tive genannt haben, die Frage nach dem Wesen der Materie, der Masse,
der Kraft, freilich nicht gelost, aber wir haben diese Fragen umgangen,
indem wir ihre Voranstellung vollstandig iiberfliissig gemacht haben.
In unserem Gedankenschema sind diese Begriffe ganz bestimmte Zahlen
und Anweisungen zu geometrischen Constructionen, von denen wir wis-
sen, wie wir sie denken und ausfiihren sollen, damit wir ein brauchbares
Bild der Erscheinungswelt erhalten. Was die eigentliche Ursache sei,
dass die Erscheinungswelt sich gerade so abspielt, was gewissermassen
hinter der Erscheinungswelt verborgen ist und sie treibt, das zu erfor-
schen, betrachten wir nicht als Aufgabe der Naturwissenschaft. Ob es
Aufgabe einer andern Wissenschaft sei und sein konne, oder ob wir da
nicht vielleicht bloss nach Analogic mit anderen verniinftigen Wortzu-
samraenstellungen hier Worte aneinandergefiigt haben, welche in diesen
Verbindungen keinen klaren Gedanken ausdriicken, das kann hier voll-
standig dahingestellt bleiben. Wir haben durch diese deductive Methode
ebenso wenig die Frage nach dem absoluten Raume und der absoluten
Bewegung gelost ; allein auch diese Frage hat keine padagogischen
Schwierigkeiten mehr ; wir brauchen sie nicht mehr beim Beginne der
Entwickelung der mechanischen Gesetze vorzubringen, sondern konnen
sie erst besprechen, wenn wir alle mechanischen Gesetze abgeleitet haben.
Denn da wir ja anfangs ohnehin nur gedankliche Constructionen vor-
flihren, so nimmt sich ein gedachtes Coordinatensystem keineswegs fremd-
artig unter denselben aus. Es ist eben eine der verschiedenen uns
verstandlichen und gelaufigen Constructionsmittel aus denen Avir unser
Gedankenbild zusammensetzen, nicht mehr und nicht weniger abstract,
als die materiellen Punkte, deren Bewegung relativ gegen das Coordina-
tensystem wir uns vorstellen und fiir welche allein wir zunachst die
Gesetze aussprechen und mathematisch formuliren. Beim Vergleiche
mit der Erfahrung finden wir dann, dass ein unveranderlich mit dem
Fixsternhimmel verbundenes Coordinatensystem praktisch vollkommen
272 Ludwig Boltzmami:
ausreicht um die Ubereinstimmung mit der Erfahrung zu sichern. Was
fiir ein Coordiiiatensystem wir eiiistens werden zu Grunde legen miissen,
wenn wir einmal die Bewegung der Fixsterne durch mechanische For-
meln ausdriicken konnten, diese Frage steht auf unserm Repertoire an
allerletzter Stelle und wir konnen jetzt alle die Hypothesen von Streintz,
Mach, Lange etc. welche eingangs erwiihnt wurden mit Leichtigkeit
discutiren, da uns alle Gesetze der Mechanik bereits zur Verfiigung stehen.
Wir kommen nicht in dieselbe Verlegenheit wie friiher, wo wir diese
complicirten Betrachtungen der Entwickelnng des Tragheitsgesetzes
hatten voranstellen miissen. Freilich haben wir dafiir bei der deduc-
tiven Methode wieder einen Beweis zu liefern, der bei den alten Methoden
iiberfliissig war. Da wir bei den letzteren direct von den Erscheinungen
ausgingen, so verstand es sich von selbst, dass die Gesetze der Erschein-
ungen nicht von der Wahl des lediglich hinzugedachten Coordinaten-
systems abhangen konnen, und es musste eben frappiren, dass sich diese
Gesetze anders und viel complicirter ausnehmen, wenn wir ein sich drehen-
des Coordinatensystem einfiihren. Bei der deductiven Methode aber
haben wir von vorne herein dem Coordinatensystem im Bilde die gleiche
RoUe angewiesen wie den materiellen Punkten. Es ist ein integrirender
Bestandtheil des Bildes und es kann uns nicht Wunder nehmen, dass
dieses verschieden ausfallt, wenn wir das Coordinatensystem anders
wahlen. Wir miissen hier im Gegentheil aus dem Bilde selbst den
Beweis liefern, dass dieses sich nicht andert, wenn wir beliebige andere
Coordinatensysteme einfiihren, so lange sich diese nicht relativ gegen
einander drehen oder nicht mit Beschleunigung relativ gegen einander
bewegen.
Wir woUen nun die zuletzt besprochene Darstellungsweise meines
Buches mit der Hertz'schen vergleichen. Herr Classen hat meine Dar-
stellung als eine Polemik gegen Hertz aufgefasst und die Sache so darge-
stellt, als ob ich mir einbildete etwas unbedingt Besseres als Hertz
vorgebracht zu haben. Nichts weniger als dies. Ich erkenne die
Vorziige des Hertz'schen Bildes unbedingt an, aber nach dem Principe,
dass es moglich und wiinschenswert ist, fiir ein und dieselbe Erscheinungs-
gruppe mehrere Bilder aufzustellen, glaube ich, dass niein Bild neben dem
Hertz'schen noch seine Bedeutung hat, indem es gewisse Vorziige auf-
weist, welche dem Hertz'schen fehlen. Die Principe der Mechanik,
welche Hertz aufstellt, sind von aussererordentlicher Einfachheit und
Schonheit. Sie sind natiirlich nicht vollstandig frei von Willkiirlich-
Erste Vorlesuiig. 273
keit, aber ich mochte sagen die Willklirliclikeit ist auf ein Minimum
beschriinkt. Das von Hertz unabhiingig von der Erfalirung construirte
Bild hat eine gewisse innere Vollendung und Evidenz. Es enthalt an
sich nur wenig willklirliche Elemente. Hingegen steht offenbar mein
Bild weit zuriick. Letzteres enthalt weit mehr Ziige, welche den Stempel
davon an sich tragen, dass sie nicht durch eine innere Notwendigkeit
bestimmt sind, sondern bloss eingefiigt wurden, um hinterher dann eben
die Ubereinstimmung mit den Erfalirung zu ermoglichen. Es enthalt
audi eine ganz willklirliche Function und von den vielen Bildern,
welche entstehen, wenn dieser Function alle moglichen Formen er-
theilt werden, entsprechen nur ganz wenige wirklichen Vorgangen,
wahrend man beim Hertz'schen Bilde sofort sieht, dass wenn iiberhaupt
einige, so doch jedenfalls nur wenige andere Bilder moglich sein
konnen, welche sich einer gleichen Einfachheit und inneren Vollendung
erfreuen, so weckt mein Bild sofort die Idee, dass es wohl noch so
manche andere geben mag, welche die Erscheinungen mit gleicher Voll-
kommenheit darstellen. Trotzdem giebt es aber wieder Punkte, in
denen mein Bild dem Hertz'schen iiberlegen ist. Hertz kann zwar einige
Erscheinungen in directer Weise, aus seinem Bilde erklaren, oder wie
wir lieber sagen woUen, mittelst desselben darstellen, so die Bewegung
eines materiellen Punktes auf eitier vorgeschriebenen Flache oder Kurve
oder die Drehung eines starren Korpers um einen fixen Punkt, beides
wolgemerkt, so lange keine fremdartigen aussern Krafte vorhanden sind.
Man stosst aber sofort auf Schwierigkeiten, sobald man die gewohnlich-
sten in der taglichen Erfahrung vorkommenden Vorgange darstellen will,
bei denen Krafte wirken. Betrachten wir zunachst eine der allgemeinsten
und wichtigsten Naturkrafte, die Gravitation. Als Fernkraft diirfen wir
dieselbe vom Hertz'schen Standpunkte natiirlich nicht auffassen. Es sind
nun zwar zahlreiche Versuche gemacht worden, sie durch Wirkung eines
Mediums mechanich zu erklaren. AUein es ist bekannt, dass keiner der-
selben zu einem recht bestimmten, entscheidenden Resultate gefiihrt hat.
Einer der bekanntesten ist die schon von Lesage aufgestellte, spater von
Lord Kelvin, Isenkrahe und andern wieder aufgenommene Theorie der
Molekularstosse. Dieselbe ist abgesehen davon, dass ihre exacte Durch-
fiihrbarkeit, noch immer zweifelhaft, ist fiir die Hertz'sche Theorie
unbrauchbar, well schon die Erklarung eines einzigen elastischen Stosses
aus derselben Schwierigkeiten bereitet, wie wir sogleich sehen werden.
Man miisste also erst eine ganz neue Theorie schaffen, die Gravitations-
274 Ludwig Boltzmann:
wirkung etwa durch Wirbel, Pulsationen oder Ahnliches erklaren,
wobei die Theilchen des betreffeiiden Mediums ebenfalls nicht durch
Kriifte im alten Sinne, sondern bloss durch Bedingungsgleichungen von
der Form, wie sie Hertz aufstellt verkniipft sein diirften. Selbst, wenn
dies gelingen sollte, so hiesse dies doch zu einem ganz willkiirlichen Bilde
greifen, welches hochst wahrscheinlich im Verlaufe der Zeit durch ein
ganz anderes ersetzt werden miisste. Der Vorwurf, welchen Hertz gegen
die alte Mechanik erhebt, dass sie ein viel zu weites Bild gibt, indem von
alien moglichen die Kraft darstellenden Functionen /(/•) nur ganz wenige
eine praktische Verwendung haben lasst sich in verstarktem Masse gegen
sein eigenes Bild kehren, sobald man dasselbe auf bestimmte Fiille anwen-
den will. Schon bei der Anwendung auf die Gravitation muss man aus
alien moglichen Medien, welche Fernwirkung vermitteln konnten irgend
ein bestimmtes auswahlen, worin wohl noch mehr Unbestimmtheit und
Willkiirlichkeit liegt als in der Wahl gewisser Functionen /(r).
Die elektrischen und magnetischen Krafte hat bekanntlich Maxwell
in seinen ersten Arbeiten mit Erfolg durch die Wirkung eines Mediums
erkltirt. AUein abgesehen davon, dass dieses Medium einen hochst
complicirten Bau hatte und von Eigenschaften strotzte, die den Stempel
der Willkiirlichkeit und eines rein provisorischen Charakters an sich
trugen, so ware es flir Hertz wieder nicht einmal brauchbar, indem seine
Theile ebenfalls von Kraften im alten Sinne der Mechanik zusammen-
gehalten werden. Ja auch die Eigenschaften der elastischen, tropf-
barfliissigen und gasformigen Korper miissten durch neue Bilder ersetzt
werden, da die bisherigen alle auf die Annahme von zwischen den Theil-
chen wirkenden Kraften gegriindet sind. Man hat also nur folgende
Walil, entweder man lasst die Natur des Mechanismus, welcher die
Gravitation, die elektrischen und magnetischen Erscheinungen erzeugen
soil, unbestimmt und willkiirlich. Dadurch entsteht eine unertragliche
Unanschaulichkeit, indem man genothigt ist immer mit Gleichungen zu
operiren, von denen man nur einige ganz allgemeine Eigenschaften kennt,
deren spezielle Form aber vollstandig unbekannt ist, oder man bemiiht
sich einen bestimmten Mechanismus zu walilen, wodurch man dann wieder
in eben so viele Willkiirlichkeiten als Schwierigkeiten verwickelt wird.
Doch ich will noch an einem viel einfacheren Beispiele die Schwierig-
keiten zeigen, auf welche die Anwendung des Hertz'schen Fundamental-
gesetzes schon in den trivialsten Fiillen stosst.
Es seien drei Massen Wj, u und Wg mit der Bedingung gegeben, dass
Erste Vorlesung. 275
sowohl die Entfernung Wj u als auch die u m^ stets gleich derselben
Grosse a sein soil. Lassen wir dann die Masse u immer kleiner werden,
so erhalten wir einen voUkommen dem Geiste der Hertz'schen Meclianik
entsprechenden Fall, der uns ein getreues Bild des folgenden Natur-
vorgangs gibt. In einer elastischen Hohlkugel von der Masse m^ bewege
sich eine kleine elastische VoUkugel ; die Differenz der Radien sei 2 a.
Wir haben also hier ein Beispiel eines und desselben Naturvorganges,
welcher auf zwei ganz verschiedenen Wegen erklart werden kann, eines-
theils aus der Molekulartheorie, anderstheils nach der von Hertz
angegebenen Methode. Aber so verhalten sich nicht alle Vorgiinge.
Schon der ganz triviale Fall des Stosses zweier elastischen Vollkugeln
ist aus dem Hertz'schen Schema nur durch zeimlich willkiirlich gewahlte
Mechanismen oder complicirte Annahmen iiber ein Zwischenmedium
ableitbar, da ja die Hertz'sche Methode Ungleichungen ausschliesst. Es
fiihrt also die Hertz'sche Methode schon in den einfachsten Fallen zu
den grossten Complicationen.
Ich betone hier nochmals, dass diese Ausfiihrungen keineswegs den
Zweck haben sollen, den hohen Wert des Hertz'schen Bildes zu leugnen,
welcher in der logischen Einfachheit seiner Grundprincipien besteht.
Es ware ja moglich, dass man in ferner Zukunft einmal alle Wirkungen
durch Medien erkliiren kann, deren Eigenschaften nicht phantastisch
gewahlt, sondern durch die Natur der Sache in nahe liegender und un-
zweideutiger Weise geboten werden. Es ware moglich, dass die Theil-
chen dieser Medien nicht Krafte im alten mechanischen Sinne aufeinander
ausiiben, sondern dass man mit Bedingungsgleichungen im Hertz'schen
Sinne zwischen den Coordinaten der Elementartheilchen ausreichen
wiirde. Von diesem Augenblicke an hatte die Hertz'sche Mechanik
in unzweifelhafter Weise den Sieg davongetragen und alle andern Dar-
stellungen hatten nur mehr historisches Interesse. Ob man das einstige
Eintreffen eines solchen Zeitmomentes fiir wahrscheinlich hiilt oder nicht
ist natiirlich eine reine Geschmackssache. Bewiesen ist nicht einmal die
Moglichkeit einer derartigen Entwicklung unserer Erkentnis. Wir wer-
den daher auf unserem gegenwiirtigem Standpunkte zu jenem Ideale mit
Bewunderung aufblicken, auch das Unserige zur Beforderung der An-
naherung an dasselbe beitragen. Aber einstweilen werden wir solche
einfache und unmittelbar brauchbare Bilder, welche sich jetzt schon
ins Detail durchfiihren lassen neben den Hertz'schen nicht entbehren
konnen.
276 Ludwig Boltzmann:
ZWEITE VORLESUNG.
Icli habe in der vorigen Vorlesung zwei Bilder der mechanischen Er-
scheinungen besprochen, welche beide rein deductiv sind, das Hertz'sche
und das in meinem Buche iiber Mechanik dargestellte. Das letztere un-
tersclieidet sich dem Wesen nach nicht von den alteren Theorien der
Mechanik. Ich bemiihte mich nur diese durch eine moglichst conse-
quente Darstellung gegen etwaige Einwiirfe besonders gegen die Be-
denken zu sichern, welche Hertz in der Vorrede seines Buches gegen
die altere Mechanik erhebt. Gerade zu diesem Zwecke schien sich die
rein deductive Darstellung am besten zu eignen, well sie das Bild ganz
unabhangig von den Thatsachen in moglichster Klarheit zu entwickeln
erlaubt. Man konnte jedoch das Bild auch nach der entgegengesetzten
Methode entwickeln, indem man unmittelbar von den Thatsachen aus-
ginge, wie sie sich der unbefangenen Beobachtung bieten, aus diesen That-
sachen die Bilder erst allmalig entstehen liesse und jede Abstraction erst
dann einfiihrte, wenn sie auf keine Weise mehr abgewiesen werden kann.
Diese letztere Darstellung woUen wir die inductive nennen. Dieselbe
hat der deductiven gegeniiber den Nachtheil, dass die Bilder von Anfang
an nicht so rein hervortreten, daher ihre innere Consequenz nicht so klar
zu iibersehen ist. AUein sie hat auch wieder den Vortheil, dass' sie an
Stelle der lange Zeit hindurch rein abstracten von der Wirklichkeit
abgekehrten Darstellungsweise der deduktiven Methode rein an das
unmittelbar Gegebene und Gelaufige ankniipfende setzt und moglichst
klar erkennen lasst, wie die abstracten Bilder entstanden sind und
warum wir gerade zu diesen Bildern unsere Zuflucht nehmen. Um die
Vorziige und Nachtheile der deductiven Methode mit der inductiven zu
vergleichen, ware es nicht ganz zweckmassig die im vorigen Vortrage
geschilderte Methode mit den alteren in der Mechanik liblichen Darstel-
lungsweisen zu vergleichen, da die letzteren beide Methoden vermischen
und dadurch wie mir scheint die Klarheit beeintrachtigen. So werden in
der Kegel sehr bald abstracte Begriffe, wie der des materiellen Punktes,
der Masse etc., eingef iihrt, diese aber nicht, wie von uns in der vorigen Vor-
lesung als rein gedankliche Werkzeuge aufgefasst. Es werden vielmehr
davon mehr oder minder unbestimmte und nichts sagende Definitionen
gegeben. So wird der materielle Punkt als ein Korper definirt, welcher
so klein ist, dass seine Ausdehnung vernachlassigt werden kann. Man
meint damit etwa, dass seine Tragheitsmomente beziiglich einer durch
Zweite Vorlesung. 277
seinen Schwerpunkt gehenden Axe gegenliber denen beziiglich einer
andern Axe verschwinden, die sich davon in einer Entfernung befindet,
die von der Grossenordnung der Entfernungen ist, welche bei unsern
Experimenten fiir gewohnlich vorkommen oder Ahnliches. Da aber der
Begriff des Tragheitsmomentes, Schwerpunkts etc. noch niclit entwickelt
worden ist, so wiisste ich niclit was man sich unter einem Korper, an dem
eine der wichtigsten Eigenschaften, namlich die Ausdehnung vernach-
lassigt werden kann, denken soil. Die Masse wird oft definirt durch
die Wirkung einer und derselben Kraft auf verschiedene Korper, aber
wie soil man constatiren, dass die Kraft dieselbe ist, wenn sie einmal
auf diesen einmal auf jenen Korper wirkt? Es wird daher das Beste
sein, wenn wir versuchen noch eine neue rein inductive Darstellung der
Grundprincipien der Mechanik wenigstens mit einigen Strichen zu ski-
ziren. Wir bleiben dabei unserm Princip treu, dass wir vorlaufig keines-
wegs eine einzige beste Darstellung der Wissenschaft erstreben, sondern
dass wir es fiir niitzlich halten moglichst viele verschiedene Darstel-
lungen zu versuchen, von denen jede ihre besondern Vorziige, freilich
auch wieder jede ihre Mangel hat. Das Hauptaugenmerk wird dabei
wieder darauf zu richten sein alle Inconsequenzen und logischen Fehler
zu vermeiden, keinen Begriff oder keine Annahme stillschweigend einzu-
schmuggeln, sondern uns aller gemachten Hypothesen mit moglichster
Klarheit bewusst zu werden. Es versteht sich von selbst, dass ich hier
bei der Kiirze der mir zur Verfiigung stehenden Zeit nicht die ganze
Mechanik erschopfend darstellen kann. Ich werde nur versuchen einige
Andeutungen zu geben. Es ware wol auch kaum moglich eine so schwie-
rige Aufgabe auf einmal ganz der Losung zuzufiihren. Viel wird an
dem ersten Versuche noch mangelhaft sein und erst allmalig werden sich
die Begriffe sichten und die Darstellungsweisen vervollkommnen. Wir
werden da gerade denjenigen Weg einschlagen miissen, der dem in der
vorigen Vorlesung geschilderten und in meinem Buche liber Mechanik
verfolgten, direct entgegengesetzt ist. Die abstracten Begriffe des mate-
riellen Punktes, der Masse, Kraft etc., von denen wir dort ausgingen,
werden wir nun zwar auch nicht ganz vermeiden konnen ; denn sie sind
einmal die Grundpfeiler, auf welche die Mechanik aufgebaut ist. Aber
wir werden sie jetzt so spiit als moglich einfiihren und wiihrend wir sie
friiher postulirten, werden wir jetzt moglichst an die Erfahrung anknlip-
fen und unsere Resultate daraus zu deduciren suchen. Daher sind jetzt
auch diejenigen Gesetze, welche friiher die einfachsten schienen, nicht
278 Ludwig Boltzmann:
voranzustellen, wie z. B. das TrJiglieitsgesetz. Dieses wird gewohnlich
dahin ausgesprochen, dass ein materieller Punkt, welcher jedem iiusseren
Einfiusse entzogen ist, sich geradlinig und gleichformig bewegt. Abge-
sehen von der Schwierigkeit, die im Begriffe des materiellen Punktes
liegt, konnen wir nun aber keinen Korper so weit von alien iibrigen
entfernen, dass er jedem Einfiusse entzogen ist und ware dies moglich,
so konnten wir seine Bewegung nicht mehr beobacliten, geschweige denn
deren Geradlinigkeit und Gleicliformigkeit constatiren. Wenn man aber
das Tragheitsgesetz an Korpern verificiren will, an denen sich alle darauf
wirkenden Kriifte das Gleichgewiclit lialten, so miisste man die gesammte
Lehre vom Gleichgewichte schon vorausschicken. Man pflegt also in
der gewohnlichen Darstellung Abstractionen und Thatsaclien vielfach
zu vermischen, was zu vermeiden eben im folgenden unsere Hauptauf-
gabe sein soil, da wir uns vornehmen streng von reinen Erfahrungsthat-
sachen auszugehen.
Die erste Unbequemlichkeit, die uns hiebei entgegentritt ist folgende:
Friiher batten wir es bei Aufstellung der ersten Grundprincipien mit rein
Gedacbtem zu thun, das wir in unserer Idee formen kdnnen, wie wir
woUen, und wovon wir verlangen konnen, dass es immer exact unseren
Anf order ungen entspriclit, jetzt dagegen woUen wir von den direct
beobachteten Erscheinungen ausgehen, welche immer sehr zusammenge-
setzt und complicirt sind. WoUen wir daraus Grundgesetze gewinnen,
so miissen wir die Erscheinungen immer generalisiren und idealisiren, so
dass wir schon nicht mehr ganz exacte Thatsachen vor uns haben son-
dern Vorgange, welche in der Natur immer nur mit grosserer oder gerin-
gerer Annilherung realisirt sind. Wir konnen es daher auch nicht ganz
vermeiden Vorstellungen und Thatsachen zu vermengen aber wir suchen
dies wenigstens auf das kleinste Mass zuriick zu fiihren und bestreben uns
es nicht versteckt zu thun, sondern wo wir dazu gezwungen sind uns
dessen klar bewusst zu bleiben.
Die Erscheinungen, welche uns gegeben sind, haben eine ausserordent-
lich verschiedene Natur. Die einfachsten bestehen in Ortsveranderungen
eines Korpers, welcher dabei weder seine Gestalt noch seine sonstigen
Eigenschaften irgendwie zu veriindern scheint. Schon diese einfache
Erscheinung ist in gewisser Beziehung eine idealisirte. In den wenigsten
Fallen iindert der Korper seine Gestalt absolut gar nicht ; ja alle, selbst
die unveriinderlichsten Korper konnen durch sehr starke Kriifte zer-
brechen, durch Hitze, chemische Wirkungen, zu volliger Veranderung ihrer
Zweite Vorlesmig. 279
Eigenschaften veranlasst werden. Aber es gibt sehr viele Korper, die doch
ihre Gestalt wiihrend der mannigfaltigsten Bewegungen durch lange Zeit
nicht bemerkbar andern. Wir nennen sie feste Korper und bilden uns
das Ideal eines absolut unveranderlichen Korpers, welchen wir einen
starren nennen. Andere Korper, die Fliissigkeiten andern wiihrend ihrer
Bewegung ihre Gestalt in der mannigfaltigsten Weise, entweder bei
(natiirlich wieder nur angenaliert) gleich bleibendem Volumen, (die tropf-
baren Fliissigkeiten) oder unter steter sehr merkbarer Anderung des Vol-
umens, (die Gase). Man kann die letzteren Erscheinungen auf die erstern
zuriickfiihren, indem man annimmt, dass die Fliissigkeiten aus sehr vielen
sehr kleinen Theilchen bestehen, deren Bewegung unabhangig von ein-
ander, die Gestaltanderung hervorruft. Andert sich dabei die durch-
schnittliche Entfernung je zweier Nachbartheilcheu, so ist dieselbe auch
mit Volumanderung verkniipft. Es ist nun die Frage, soil man sich die
Anzahl dieser Theilchen mathematisch unendlich oder bloss sehr gross
aber endlich denken. Viele Erfahrungsthatsachen deuten darauf hin,
dass die letztere Annahme gemacht werden muss, welche auch philoso-
phisch die befriedigendere ist. Aber da eine unzweifelhafte experi-
mentelle Entscheidung bisher nicht erfolgt ist, so wollen wir getreu den
Principien, nach denen wir jetzt vorzugehn beabsichtigen, diese Frage
voUstandig in suspenso lassen.
Alle Ortsveranderung heissen Bewegungen. Die Lehre von den
Bewegungserscheinungen ist die Mechanik, welche sich in die Geo-, Hydro-
und Aero-mechanik abtheilt, je nachdem man es mit der Bewegung
fester, tropfbarer oder gasformiger Korper zu thun hat. Die Mechanik
umfasst ihrer Definition gemass auch die Bedingungen, unter denen sich
ein Korper garnicht bewegt.
Es gibt noch vielerlei Erscheinungen der Schall, die Warme, das
Licht, die elektrischen und magnetischen Erscheinungen, die ganzliche
Anderung der Eigenschaften von Korpern bei chemischen Prozessen, die
Geruchs-, Geschmackerscheinungen etc. Letztere sind wahrscheinlich
nur spezielle Falle von Verdampfungs- oder chemischen Erscheinungen,
und daher fiir die Physik von geringerer Wichtigkeit, welche ja die
Action auf die Nerven und die Fortleitung durch dieselben bis zum
Bewusstwerden der Physiologic und Psychologic iiberlasst. Aber sie
miissen hier doch ebenfalls erwahnt werden.
Es ist unzweifelhaft nachgewiesen, dass den Schallerscheinungen
Bewegungen der Korper zu Grunde liegen. Naturgemass suchte man
280 Ludwig Boltzmann:
auch Licht, ElektricitJit und Magnetismus, so wie die chemischen
Ersclieinungen durch Bewegungserscheinungen gewisser hypothetischer
Medien oder hypothetischer kleinster Theile zu erklaren und bis vor
Kurzem war wohl jeder Physiker iiberzeugt, dass hiemit dem Wesen nach
die eigentliche Aufgabe der Physik ausgesprochen sei. Erst vor wenigen
Decennien wurde unwiderleglich nachgewiesen, dass die besonders in
Deutschland friiher allgemein verbreitete Theorie der elektrischen und
magnetischen Fluide mit den Thatsachen nicht in Ubereinstimmung
gebracht werden kann. Man wurde nun vorsichtiger, man suchte zwar
die elektrischen und magnetischen Erscheinungen zuuiichst wieder durch
mechanische Wirkung eines Mediums zu erklaren, allein da man hiebei
nicht zu einem bestimmten eindeutigen Erfolge gelangte, so neigen in
neuester Zeit manche Physiker zur Ansicht, dass es wol ein iibereilter
Schluss sei, dass sich alle Erscheinungen durch Bewegungsphanomene
miissten erklaren lassen oder in unsere Ausdrucksweise iibertragen, dass
es vielleicht gar nicht moglich sei durch die Bilder von Ortsverander-
ungen von Punkten und Korpertheilen allein sich ein ausreichendes
Bild der Erscheinungen zu verschaffen ; dass man dazu noch qualitativ
verschiedene Bilder wie dielektrische und magnetische Polarisationen,
chemische Zustande oder anderes dazunehmen miisse. Es wiirde
dadurch die Einheit der Naturwissenschaft ausserordentlich leiden, da
man auf keinen Fall die alten einfachen Bilder vermeiden konnte und
uns noch eine Menge fremdartiger dazu einfiihren miisste. Es wiirde
dann auch die Bedeutung der Mechanik als Grundlage der gesammten
Naturwissenschaft, auf welcher alle iibrigen Theorien derselben beruhen,
in Frage gestellt. Aber immer hatte noch die Mechanik als die Lehre
der einfachsten Erscheinungen, ohne die irgend welche andere nicht
denkbar sind, alien andern physikalischen Theorien voranzugehn. Wenn
man daher auch einerseits nicht leugnen kann, dass der Beweis der
mechanischen Erklarbarkeit aller Naturerscheinungen noch nicht geliefert
ist, so ist doch sicher ebenso wenig ein Beweis geliefert, dass gewisse
Naturerscheinungen nicht durch mechanische Bilder erkliirbar sein
konnten, und man kann hochstens die Ansicht aussprechen, dass bei gewis-
sen Naturerscheinungen der Versuch einer mechanischen Erkliirung heute
noch zu friih kommt. Die allgemeine Frage an sich kann erst nach
Jahrhunderten entschieden oder wenigstens in ein wesentlich neues Licht
gerilckt und geklart werden. Wir wollen uns daher mit der Discussion
des "Fiir" oder "Wider" hier nicht aufhalten, sondern kehren zur Beweg-
Zweite Vorlesung. 281
ung eines festen Korpers K zuriick, den wir sogleich idealisiren, indera
wir ilin als absolut starr denken. Wir fassen denselben nicht etwa als
eiuen materiellen Punkt, sondern als einen erfahrungsmassig gegebenen,
wenigstens dem Scheine nach continuirlicli ausgedehnten Korper auf.
Wir miissen freilich wieder sogleich mit einer Abstraction einsetzen ; wir
konnen die Bewegung des Korpers nicht auf einmal als Ganzes erfassen,
da er ja (wenigstens fiir uns scheinbar) aus unendlich vielen Theilen
besteht. Wir konnen bloss die Bewegung einzelner Punkte desselben
klar mit dem Auge und Gedanken verfolgen. Wir wollen daher sehr
kleine Stellen desselben A^ B^ C, . . . mit feinen selbstverstandlich
ebenfalls starr mit dem Korper verbundenen Marken bezeichnen etwa
mit feinen Farbepunkten, Mehlstaubchen oder durch die Kreuzung zweier
feiner Linien etc. Wenn wir eine ausserordentlich enge Hohlung in den
Korper bohren, so konnen wir auch Punkte im Innern desselben wirklich
bezeichnen und wir konnen es auch ohne die Hohlung in Gedanken,
wenn wir uns etwa einen geometrisch ahnlichen hohlen oder durchsichti-
gen oder sonst an dieser Stelle zuganglichen Korper vorstellen. Es ist
freilich schon wieder eine Idealisirung, wenn wir uns diese bezeichneten
Stellen als mathematische Punkte denken ; allein wir bleiben doch dem
thatsachlich Realen viel naher, wenn wir die Bewegung des ausgedehnten
Korpers durch solche Punkte beschreiben und an erster Stelle einfache
Gesetze fiir die Mechanik ausgedehnter Korper zu gewinnen suchen, als
wenn wir direkt mit den Gesetzen fiir die Bewegung einzelner materieller
Punkte beginnen. Wir konnen jetzt genauer beschreiben, was es heisst,
wenn wir sagen die Gestalt eines Korpers iindert sich wahrend seiner
Bewegung nicht. Wir konnen durch Anlegen eines Massstabes oder
zweier Zirkelspitzen, die wir dann auf einen Massstab iibertragen die Ent-
fernung je zweier beliebiger Punkte des Korpers K d. h. zweier beliebiger
hervorgehobener Marken auf demselben messen. Wenn dieselbe fiir alle
Punktepaare zu alien Zeiten unveriindert bleibt, so sagen wir die Gestalt
des Korpers ist unveriinderlich. Fiir die Unveriinderlichkeit des Mass-
stabes oder Zirkels haben wir freilich keine objective Garantie, sondern
nur die empirische, dass uns dieselben an alien Korpern, welche schon dem
Augenscheine nach ihre Gestalt nicht andern, die richtige Anzeige liefern.
Wenn alle festen Korper in gleicher Weise ihre Dimensionen mit der
Zeit andern wiirden, so konnten wir dies natiirlich nicht bemerken.
Wir haben auch durchaus nicht die Absicht zu erkliiren, wieso es feste
Korper gibt, wieso wir die Entfernungen der damit fest verbundnen
282 Liidivig Boltzmann:
INIarken messen konnen. Wir nehmen dies als Erfahrungsthatsachen bin,
nur die Gesetze der Veriinderung der Entfenmngen der Marken ver-
schiedener Korper oder auch desselben Korpers falls dieser nicht starr ist,
woUen wir durch unsere Vorstellungsbilder darstellen.
Vorbedingung jeder wissenschaftlichen Erkenntniss ist das Princip der
eindeutigen Bestimmtheit der Naturvorgiinge, auf die Mechanik ange-
wandt der eindeutigen Bestimmtheit aller Bewegungen. Dasselbe sagt
aus, dass die Bewegungen der Korper nicht rein zufallig bald so, bald
anders vor sich gehn, sondern dass sie durch die Umstande, unter denen
sich der Korper befindet, eindeutig bestimmt sind. Wenn jeder Korper
sich wie er woUte bewegte, wenn unter gleichen Umstanden bald diese,
bald jene Bewegung je nach Zufall erfolgte, so konnten wir dem Verlaufe
der Erscheinungen nur neugierig zusehen nicht ihn erforschen. Auch
hierin liegt wieder eine Unbestimmtheit, die Umstande, unter denen die
Bewegung irgend eines Korpers vor sich geht, urafassen streng genom-
men das ganze Universum. Dasselbe ist nie zweimal im selben Zustande.
Wir mlissen also unsere Bedingungen dahin reduziren, dass immer die-
selbe Bewegung erfolgt, wenn die unmittelbare Umgebung sich in dem-
selben Zustande befindet. Wir sind hier bei der inductiven Methode
wieder in einer weit ungiinstigeren Lage als bei der Deductiven. Denn
da wir bei der letztern mit der Aufziihlung der Wirkungsgesetze ohne
Riicksicht auf jede Erfahrung beginnen, so liegt es ganz in unserer
Hand gleich anfangs willkilrlich festzustellen, von welchen Umstanden
die Bewegung eines Korpers abhangt und welche darauf ohne Einfluss
sind. Bei der inductiven Methode hingegen miissen wir den Begriff der
unmittelbaren Umgebung eines Korpers, deren Zustand auf seine Beweg-
ung von Einfluss ist, nach der Erfahrung bestimmen. Nach der Nahe-
wirkungstheorie sind es nur die unmittelbar anliegenden Volumelemente,
welche die Bewegung irgend eines Volumelementes bestimmen. Nach
dieser Theorie wirkt die Erde nicht direct anziehend auf den schweren
Korper sondern sie wirkt nur auf die Volumelemente eines Mediums,
durch welche sich die Wirkung bis zum schweren Korper fortpflanzt.
Aber wenn wir den Principien unserer jetzigen Darstellungsweise treu
bleiben wollen, so diirfen wir nicht die Nahewirkungstheorie zur Basis des
gesammten Gebaudes der Mechanik machen, wir diirfen vielmehr hiezu
nur Gesetze verwenden, welche nichts Willkiirliches enthalten, sondern uns
durch die Erfahrung eindeutig und notwendig aufgedriingt werden. Die
Nahewirkungstheorie aber, so wahrscheinlich sie vielleicht manchem
Zweite Vorlesung. 283
a priori erscheint, gelit doch vollstandig iiber das rein Thatsachliche liinaus
und kann heutzutage noch keineswegs ins Detail ausgearbeitet werden.
Wir wlirden da in denselben Feliler verfallen, den wir der Hertz'schen
Darstellungsweise vorgeworfen haben. Wir miissten entweder ganz will-
kiirliche spezielle Hypotbesen fiir die Art und Weise der Nabewirkung
erfinden oder uns mit allgemeinen unbestimmten Vorstellungen iiber die-
selbe begniigen.
Wir miissen daber die ganze Erde zur Umgebung des schweren Kor-
pers recbnen aber Mond und Sterne dabei ausser Acbt lassen, da letztere
keinen bemerkbaren Einfluss ausiiben. Es ist also wieder eine reine
Annabme, welcbe wir erst nachtraglicb durcb die Erfahrung recbtfertigen
miissen, dass wir die unmittelbare Umgebung immer so abzugrenzen ver-
mogen, dass wir alles Wesentlicbe einscbliessen und dass wir so factiscb
zu einer Aufstellung von Bewegungsgesetzen gelangen konnen.
Wie werden wir uns nun bei unserer jetziger Darstellungsweise dem
absoluten Raume und der absoluten Zeit gegeniiber verhalten? An
einem Tbeile des absoluten Raumes konnen wir keine Zirkelspitze ein-
setzen sondern nur an materiellen Korpern. Wir konnen daher nur
die Bewegung von materiellen Korpern relativ gegen einander bestimmen.
Wir diirfen jetzt nicht wie bei der deductiven Methode das Gedanken-
bild eines fingirten Coordinatensystems unter die von uns gegenwiirtig
allein betracbteten realen Korper mengen. Dem Geiste unserer Metbode
entsprecbend miissen wir vielmebr unsere Betrachtungen moglicbst dem
historischen Entwickelungsgange der Mecbanik anschliessen. Galilei
hat die einfacben Bewegungsgesetze gefunden, indem er die Bewegung
relativ gegen die Erde studirte. Seinem Beispiele folgend werden wir
daher ausser dem Korper JT, dessen Bewegung wir beschreiben wollen,
noch ein System von anderen Korpern in die Betrachtungen mit einbe-
ziehen, welche die Bedingung erfiillen, dass alle ibre Punkte ihre Ent-
fernungen von einander nicht andern, dass sie also alle relativ ruhen.
Dieses System nennen wir das Bezugssystem. Wenn wir daher die
Bewegung eines festen Korpers gegen ein Bezugssystem studiren und
wenn A^ B, C . . . markirte Punkte des ersteren, ^, F, Cr . . . solche des
letztern sind, so andern sich weder die Entf ernungen AB, AO . . . noch
UF, ECr . . . und unsere Aufgabe besteht bloss darin, die Gesetze
der Veriinderungen, der Entfernungen AE, AF, BF . . . aufzustellen.
Natiirlich sind hiebei auch wieder vielerlei Idealisirungen notwendig.
Wir werden kein System von Korpern als Bezugssystem auffinden
284 Ludivig Boltzmann:
konnen, welche so bescliaffen sind, dass sie zu alien Zeiten relativ gegen-
einander ihre Lage absolut beibehalten. Es geiiligt, wenn diese Beding-
ung angeniihert durch geniigend lange Zeit erfiillt ist.
Ferner konnen wir nicht wissen, ob wir dieselben Gesetze erhalten,
wenn wir das eine oder andere Bezugssystem wiihlen. Wir werden
daher jedenfalls ein solches Bezugssystem zu wiihlen haben, dass wir ein-
fache Gesetze fiir die Bewegung erhalten. Es zeigt sich in der That,
dass die Gesetze, welche wir bei zu Grundelegung des Fixsternhimmels
als Bezugssystem erhalten nicht ohne kleine Correctionen auf die Beweg-
ung relativ gegen die Erde angewandt werden konnen und es muss als
ein fiir die Entwickelung der Mechanik ausserordentlich glinstiger Zufall
bezeichnet werden, dass der Einfluss der Erddrehung auf die verschiedenen
Bewegungen, welche wir auf ihrer Oberflache beobachten ein so ausser-
ordentlich geringer ist. Sonst ware es weit schwieriger gewesen die
Grundgesetze der Mechanik herzuleiten. Diesem Umstande ist es zu ver-
danken, dass wir fiir die Bewegungen auf der Erde den Erdkorper als
Bezugssystem wiihlen konnen. Wir erhalten hiedurch einfache Gesetze,
denen die wirklichen Bewegungen freilich nicht mit absoluter Genauig-
keit folgen, aber die Abweichungen sind so gering, dass sie sich fast der
Beobachtung entziehen. Dies konnten wir freilich nicht a priori wissen ;
aber es ist kein logischer Fehler, wenn wir zunachst die Gesetze der
Relativbewegung gegen die Erde studiren. Finden wir einfache Gesetze,
so ist es wieder kein logischer Fehler, deren Anwendung auf die Beweg-
ung der Planeten relativ gegen das Fixsternsystem zu versuchen. Bei
dieser Erweiterung zeigt sich dann erst einestheils, dass sie auch fiir den
ersten Fall angeniihert richtig sein miissen, anderseits aber, dass derselbe
doch kleiner Correctionen bedarf. Diese Correctionen sind so klein
dass sie uns bei Auffindung der Gesetze aus den irdischen Bewegungen
nicht storten, dass sie aber jetzt nachdem wir ihre Grossenordnung kennen
gelernt haben doch mit feinen Hilfsmitteln beobachtet werden konnen.
Dass die wirklichen Bewegungen dann gerade die durch diese Correctionen
bedingten Eigenthiimlichkeiten zeigen, reehtfertigt nachher in gliinzender
Weise unsere Methode. Hiemit ist wieder die piidagogische Schwierig-
keit beseitigt, welche durch die Relativitiit aller Bewegungen bedingt
wird. Die Frage, auf welches Bezugssystem wir die Fixsternbewegungen
zu beziehen haben, ist hiemit freilich nicht gelost, aber es liegt in keiner
Weise eine Notwendigkeit vor, diese Frage vor Aufstellung der siimmt-
lichen Gesetze der Mechanik zu behandeln.
Zweite Vorlesimg. 285
Wir haben bisher iiber die Gestalt und Anordnung der Korper des
zu Grunde gelegten Bezugssystems keine besondere Annahme gemacht.
Es hat nun keine Schwierigkeit mit denselben drei fixe auf einander
rechtwinklige Gerade vorbunden zu denken, welche man als Coordinaten-
axen wiihlen kann. Die Lage jedes an dem betreffenden Korper mar-
kirten Punktes ist dann zu jeder Zeit durch dessen rechtwinklige
Coordinaten beziiglich dieses Coordinatensystems bestimmt. Wenn
sich diese mit der Zeit nicht andern, so befindet sich der Korper
in relativer Ruhe gegen das Bezugssystem. Wenn sie sich andern,
so ist er in Bewegung Um den letztern Fall beschreiben zu konnen,
ist noch die genaue Fixirung des Zeitmasses erforderlich. Gerade
so wie wir schon mit Hilfe des Augenmasses oder des Tastgefiihles
grossere raumliche Ausdehnungen von kleineren unterscheiden, einen
genauen zahlenmassigen Ausdruck der Raumgrosse aber nur durch Ver-
gleich mit einem rationell construirten Massstabe gewinnen konnen, so
konnen wir auch schon durch das Gefiihl (den Zeitsinn) langere Zeit-
raume von kiirzern unterscheiden, miissen uns aber ein genaues quantita-
tives Zeitmass durch die Hilfsmittel verschaffen, welche schon in der
ersten Vorlesung angedeutet wiirden. Wir miissen uns da vor allem
eine Reihe von Vorgangen verschaifen, bei denen wir vollkommen oder
besser gesagt, thunlichste Garantie haben, dass sie sich in gleichen Zeiten
abspielen. Wir konnen etwa ganz gleiche Korper unter ganz gleichen
Umstiinden fallen lassen oder ganz gleiche Pendel um gleiche Strecken
aus der Ruhelage entfernen. Wenn das erste die Ruhelage erreicht,
lassen wir das zweite seine Bewegung beginnen etc. Ob wir gegenseitige
Storungen wirklich geniigend vermieden haben, kann natiirlich nur der
Vergleich mit verschiedenen analogen Versuchen zeigen. Wir sehn
natiirlich bald, dass auch ein Pendel die verschiedenen sich folgenden
Schwingungen nahe unter den gleichen Umstanden vollzieht und konnen
diese zur Zeitmessung benutzen. Freilich ist der absolute Isochronismus
der Schwingungen wieder ein Ideal, Temperatur, Barometerstand, Sonne
und Mond haben darauf Einfluss, aber wie alle diese storenden Umstande
bei gut gearbeiteten Chronometern moglichst vermieden werden, wie
durch eine treibende Kraft die Schwingungen sehr lange erhalten werden,
dass man, wenn ein bestimmtes Chronometer endlich unbrauchbar wird,
dafiir ein anderes moglichst gleichbeschaffenes substituiren kann, das
alles ist nicht mehr Sache unserer gegenwartigen allgemeinen Betrach-
tungen.
286 Ludwig Boltzmann:
Wir wahlen einen bestimmten Zeitmoment z. B. den, der einem
bestimmten willkiirlich gewiihlten Durchgang durch die Ruhelage ent-
spricht, als Zeitmoment Null, den des ntichsten Durchgangs durch die
Rulielage als Zeit 1, die welter folgenden als die Zeiten 2, 3 u.s.w. Die
Unterabtheilungen konnen wir durch. schneller schwingende Stimmgabeln
oder durch Bewegungen bestimmen, die sich fiir grossere Intervalle unter
alien Umstanden als geniigend gleichformig erwiesen und von denen wir
Ursache haben dies auch fiir kleinere Intervalle zu vermuten. So gewin-
nen wir die Zeiten ^, \ u.s.w und es lasst sich keine Grenze der
Unterabtheilung feststellen. Die negativen Zahlen bezeichnen die
Schwingungen vor derjenigen der wir die Zeit Null zugeordnet haben.
In dieser Weise kdnnen wir alle Zeiten durch positive, negative, ganze,
gebrochene, irrationale Zahlen darstellen, wie wir die Langen durch die
Zahl darstellen, welche angibt, wie oftmals sie die Liingeneinheit enthal-
ten. Die Differenz der Zahlen, welche zwei gegebene Zeiten darstellen
heisst das dazwischen liegende Zeitintervall oder die Zeitdifferenz auch
die inzwischen vorflossene Zeit. Unsere gewohnliche Zeiteinheit leiten
wir von der Umdrehungszeit der Erde ab, deren Gleichformigkeit aber
bei Ableitung der Principien der Mechanik wol besser durch einfachere
Vorgange controlirt wird, da es ohne Kenntnis der mechanischen Gesetze
nicht so ohne welters evident ist, dass die Umdrehungsgeschwindigkeit
an alien Stellen der Erdbahn dieselbe bleibt.
Wir kehren nun zuriick zu unserem Korper K^ den wir auf ein mit
dem gewahlten Bezugssysteme fest verbundenes Coordinatensysten Ox^
Oy^ Oz beziehen. Ein auf demselben hervorgehobener Punkt befinde
sich zu einer bestimmten Zeit t m. A und habe die rechtwinkeligen Coor-
dinaten x, ?/, z. Wir verbinden ihn durch die Gerade OA mit dem Coor-
dinatenursprunge : Diese Gerade heisst der Lagenvector des Punktes A^
ihre Projectionen auf die drei Coordinatenaxen sind die drei Coordinaten
a;, ^, z. Wenn nun der Korper eine gewisse gegebene Bewegung macht,
so miissen wir zunachst jeden Zeitmoment der Bewegung etwa durch
Vergleichung der gleichzeitigen Bewegung unseres Chronoskops durch
eine Zahl darstellen. Es wird zu jeder Zeit eine bestimmte Lage des
Korpers gehoren, daher auch des Punktes A desselben, daher auch be-
stimmte Werte der Coordinaten t/, a;, 2, welche wir uns ebenfalls durch
reine Zahlen (ganze oder gebrochene Vielfache der Langeneinheit) dar-
gestellt denken. Zu jedem Zahlenwerte der Zeit t gehort also ein ein-
deutig bestimmter Zahlenwert der Coordinate x, x ist eine eindeutige
Zweite Vorlesung. 287
Funktion von t, ebenso y unci z. Wir schreiben dies so x=^(t),
y = x(0^ ^ = "^(0 ^^nd nennen t das Argument oder die independente
Variabele, x, y, z aber die dependenten Variabeln. Wir konnen es zu-
nachst als hinlanglich sicher gestellte Erfahrungsthatsache betrachten,
dass ein Korper nie aus einer Lage plotzlich verschwindet und im
nachsten Zeitmomente in einer andern um Endliches davon Ver-
schiedenen wieder zum Vorschein kommt und dass dies auch von jedem
Theile eines Korpers gilt, dass also ^, x-> i^ continuirliche Functionen
der Zeit sind, d. h. ihre Zuwachse verschwinden um so mehr je kleiner
der entsprechende Zuwachs der Zeit ist. Die von den verschiedenen
Lagen des Punktes A zu den verschiedenen Zeiten gebildete Curve nen-
nen wir die Bahn dieses Punktes, denjenigen Theil derselben, welcber
alien Lagen, die wahrend einer gegebenen Zeit durchlaufen werden ent-
spricht den wahrend dieser Zeit zuriick gelegten Weg.
Nicht ganz so sicher als die Continuitat der Functionen <^, ^i "^ ist
es, ob sie auch differenzirbar sind. Man driickte sich in der alten
Mechanik folgendermassen aus. Es lege ein Punkt eines Korpers, wahr-
end einer sehr kleinen Zeit Bt einen sehr kleinen Weg Ss zuriick. Es sei
nun a priori evident, dass sich wahrend dieser kleinen Zeit, die Umstande,
unter denen sich der Korper befindet nur sehr wenig geandert haben kon-
nen, dass es daher, wahrend der nachst folgenden Zeit Bt wieder einen
sehr nahe gleichen und gleich gerichteten Weg Bs zurlicklegen muss, so
dass also fiir kleine Zeiten sowohl der Weg als auch die Coordinatenzu-
wachse der verstrichenen Zeit proportional sein miissen. Man glaubte
damals iiberhaupt, dass jede iiberall endliche continuirliche Function einen
Differenzialquotienten haben muss. Weierstrass hat bekanntlich gezeigt,
dass dies ein Irrthum ist. Bezeichnen wir z. B. mit y die Weierstrass-
ische Reihe so nahert sich der Zuwachs des y, der irgend einem Zuwachse
des X entspricht an alien Stellen immer mehr der Nulle, wenn sich der
betreffende Zuwachs das x der Nulle nahert und trotzdem nahert sich
der Quotient beider Grossen niemals einer bestimmbaren Grenze. Bei
der deductiven Darstellung ergibt sich hieraus wieder nicht die mindeste
Schwierigkeit. Wir konnen ja dann unser Bild formen, wie wir woUen
und einfach die Differenzirbarkeit von vornherein in dasselbe aufneh-
men, es damit rechtfertigend, dass das Bild hinterher mit der Erfahrung
stimmt. Aber jetzt ist es unsere Absicht von der Erfahrung auszugehn.
Nun lehrt uns zwar diese, dass sehr haufig, wahrend kleiner noch beob-
achtbarer Zeiten der Weg eines Punktes eines Korpers um so genauer
288 Luclwig Boltzmcmn:
der verflossenen Zeit proportional ist, je kiirzer diese ist, woraus wir wohl
auf die Differenzirbarkeit der Functionen 0, %, i/r schliessen konnen.
Allein wir kennen auch Beispiele sehr rascher Oscillationen uiid konnen
nicht exact beweisen, ob nicht in gewissen Fallen Bewegungen vorhanden
sind, wie z. B. die Warmebewegungen der Molekiile, welche durch eine
der Weierstrass'schen Function ahnliclie besser als durch eine Differen-
zirbare dargestellt werden. Doch sind dies allerdings Dinge von gering-
erer Wichtigkeit und wir wollen daher die Differenzirbarkeit der Coor-
dinaten nach der Zeit unsern weitern Uberlegungen zu Grunde legen.
Unter dieser Voraussetzung existiren die Ableitungen der Functionen
<^, %, -^ nach der Zeit. Wir nennen sie die Componenten der Geschwin-
digkeit des Punktes A des Korpers. Die Geschwindigkeit selbst konnen
wir in folgender Weise construiren : Es befinde sich der markirte Punkt
des Korpers zur Zeit t \n A zur Zeit t -{- Win B, so dass also OA, und OB
die dazu gehorigen Lagenvectoren sind. Die Gerade AB ist dann das,
was man die Differenz der beiden Vectoren nennt. Wir construiren
nun einen Vector, welcher die Richtung AB hat und dessen Lange der
Quotient AB dividirt durch 8t ist. Ferner suchen wir die Grenze, wel-
cher sich dieser Vector in Grosse und Richtung nahert, wenn Bt immer
mehr abnimmt. Die so bestimmte Lange ist die Geschwindigkeit, die
Richtung aber, der sich der Vector nahert, die Geschwindigkeitsrichtung.
Wir wollen hier noch eine Bemerkung anfiigen. Damit wir den Weg
durch die verfiossene Zeit dividiren konnen, miissen beide durch reine
Zahlen ausgedriickt sein und wir haben gesehen wie dies geschieht.
Wahlen wir die Langeneinheit a mal so gross, so wird die Zahl, welche
nun eine gewisse Lange ausdriickt a mal kleiner. Es ist moglich, dass
auch andere Grossen dieselbe Eigenschaft haben, dass sie durch a mal
kleinere Zahlen ausgedriickt erscheinen, sobald wir die Langeneinheit
a mal vergrossern. Von alien so beschaffenen Grossen sagen wir dann,
dass sie die Dimension einer Lange haben. Jede Lange, (der Weg, die
Coordinaten etc.) hat daher selbstverstandlich die Dimension einer Lange.
Die Zahl, welche uns die Zeit t ausdriickt, ist natlirlich unabhangig von
der gewahlten Langeneinheit, wird aber a mal kleiner, wenn wir die
Zeiteinheit a mal grosser wahlen und wir sagen von jeder Grosse, welche
durch eine Zahl von dieser Eigenschaft ausgedriickt wird, sie habe die
Dimension einer Zeit. Die Geschwindigkeit wird durch den Quotienten
zweier Zahlen gemessen, wovon der Zahler die Dimension einer Lange,
der Nenner die einer Zeit hat. Sie ist also sowohl von der Wahl der
Zweite Vorlesung. 289
Langen als auch von der Zeiteinheit abhangig, und wird a mal kleiner,
wenn die erstere a mal grosser, dagegen a mal grosser, wenn die letztere
a mal grosser gewahlt wird. Wir sagen daher ihre Dimensionen sind :
Lange dividirt durch Zeit, was aber hiemit jeder geheimnisvollen oder
metaphysischen Bedeutung eutkleidet ist. Man redet vielfacli statt von
dem Quotienten der Zahl welclie die Zeit ausdriickt in die, welclie die
Lange ausdriickt, einfach von dem Quotienten einer Zeit, in eine Lange.
Man hat da den Begriff der Division erweitert und muss den Quotienten
einer Zeit in eine Lange ganz neu definiren, geradeso wie man den Begriff
einer negativen oder gebrochenen Potenz neu definirt und darunter einen
Bruch respektive eine Wurzel versteht. Der Vortheil dieser neuen Defi-
nition besteht darin, dass man vielfacli Rechnungsregeln, welclie fur die
friihere Definition bewiesen wurden auf die neue Definition iibertragen
kann. Man darf aber nicht a priori schliessen, dass dies von alien Rech-
nungsregeln gilt ; es muss vielmehr die Ubertragbarkeit von jeder Rech-
nungsregel besonders bewiesen werden. Ebenso ist es eine vollstiindig
neue Definition, wenn wir unter der zweiten oder dritten Potenz eines Cen-
timeters die geometrische Figur eines Quadrats oder Wiirfels von 1 cm.
Seitenlange verstehen und es muss gerechtfertigt werden, in wie weit
diese neue Definition zweckmassig ist. Die Fixirung des Begriffs der
Beschleunigung und ihrer Componenten nach den drei Coordinaten-
richtungen hat nun nicht mehr die mindeste Schwierigkeit. Sei A Q der
Vector, welcher in Grosse und Richtung die Geschwindigkeit zur Zeit
t, OB der, welcher sie zur Zeit t-^U darstellt. Wir ziehen die Gerade
(72), also die Differenz der beiden Vectoren. Dieselbe wird sehr klein
sein, wenn ht sehr klein ist. Wir erhalten aber eine endlich bleibende
Gerade, wenn wir sie im Verhaltnis der Zeiteinheit zur Zeit U vergross-
ern, wobei ihre Richtung unverandert bleiben soil. Die Grenze, welcher
sich der so vergrosserte Vector CD mit abnehmendem ht nahert, heisst
der Beschleunigungsvector, seine Lange stellt die Grosse, seine Richtung
die Richtung der Beschleunigung dar. Seine Componenten in den drei
Coordinatenrichtungen heissen die Componenten der Beschleunigung.
Man iiberzeugt sich in bekannter Weise, dass es die zweiten Ableitungen
der friiher mit x^ ' "^ bezeichneten Functionen sind. Wir mlissen
daher die Voraussetzung machen, dass diese Functionen auch zweite
Ableitungen haben. Man iiberzeugt sich auch leicht, dass die Zahl,
welche die Grosse der Beschleunigung ausdriickt wieder sowohl von den
gewahlten Langen als von der gewahlten Zeiteinheit abhangt und a mal
290 Ludwig Boltzniann:
kleiner wird, wenn erstere a mal so gross, dagegen a?- nial grosser, wenn
die Zeiteinheit a mal so gross gewiihlt wird. Wir werden daher sagen,
die Beschlemiigung hat die Dimensionen : Liinge dividirt durch das
Quadrat der Zeit. Wir konnen wieder die Beschleunigung als solche
definiren als den Quotienten einer Zeit in eine Geschwindigkeit oder des
Quadrats einer Zeit in eine Lange ; diirfen aber die letzteren Defini-
tionen nur mit einer gemssen Vorsicht anwenden, da sie Erweiterungen
des Begriffs der allgebraischen Division darstellen, fiir welche die An-
wendbarkeit der verscliiedenen in der Algebra bewiesenen Rechnungs-
regeln erst neu erprobt werden muss.
Nachdem wir diese Begriffe moglichst an die Erfabrung ankniipfend
entwickelt haben, miissen wir zur Aufstellung der Gesetze iibergehn,
nach welcben die Bewegung der Korper gescbielit. Wir werden da
natiirlich wieder nicht mit Aufstellung der Gesetze fiir die Bewegung
eines materiellen Punktes beginnen, da dieser eine reine Abstraction ist.
Wir werden uns natiirlich auch nicht der Illusion hingeben, dass wir ohne
alle Abstractionen auskommen. Wir konnen nach meiner Ansicht nicht
einen einzigen Satz aussagen, welcher wirklich nur eine reine Erfahrungs-
thatsache ware. Die einfachsten Worte wie gelb, siiss, sauer etc., welche
blosse Empfindungen anzugeben scheinen, driicken schon Begriffe aus,
die bereits aus vielen Erfahrungsthatsachen durch Abstraction gewonnen
worden sind. Wenn Gothe sagt, die Erfahrung ist nur zur Halfte
Erfahrung so will er mit diesem scheinbar paradoxen Satze sicher aus-
drlicken, das wir bei jeder begrifflichen Auffassung der Erfahrung oder
Darstellung derselben durch Worte schon liber die Erfahrung hinaus-
gehen miissen. Die oft aufgestellte Forderung, dass die Naturwissen-
schaft nie iiber die Erfahrung hinausgehen diirfe, sollte daher nach
meiner Ansicht dahin ausgesprochen werden, dass man nie zu weit iiber
die Erfahrung hinaus gehen diirfe und nur solche Abstractionen ein-
fiihren soUe, die sich bald wieder an der Erfahrung priifen lassen. Wir
werden auch nicht das Tragheitsgesetz an die Spitze stellen. Dieses mag
theoretisch das einfachste Gesetz der Mechanik sein, physikalisch ist es
keineswegs das einfachste, da es eine ganze Reihe von Abstractionen
zur Voraussetzung hat, worauf ich schon friiher hingewiesen habe. Als
die beiden physikalisch einfachsten Falle erscheinen uns vielmehr erstens
der der relativen Ruhe zweitens, der freie Fall eines schweren Korpers.
Wie wir sahen, konnen wir einen Korper niemals ganz den aussern Ein-
fliissen entziehen. Wenn nun solche Einfliisse vorhanden sind, von denen
Ztveite Vorlesung. 291
jeder fiir sich allein eine Bewegung erzeugen wiirde, wenn aber unter dem
vereinten Einflusse aller relative Ruhe gegen das Bezugssystem Platz
greift, so sagen wir alle Ursachen der Relativbewegung compensiren sich.
Ich konnte micli auch des gebrauchlichsten Ausdruckes bedienen, die
Krafte halten sich das Gleichgewicht, allein ich will absichtlich die gewohn-
ten Ausdriicke vermeiden, well wir mit denselbeii unwillkiirlich eine Menge
von Vorstellungen verbinden, die sich dann, ohne dass wir es wollen,
unkontrolirt in unsere Schlussweise einschmuggeln und so den Schein
erwecken, als hatten wir etwas bewdesen, was wir nur gemass unserer
alten Denkgewohnheit und Ideenassociation ohne Begriindung beigefiigt
haben. Ich will ausserdem das Wort Kraft vermeiden, ehe ich gleich-
zeitig auch von der Masse sprechen kann. Endlich betrachten wir liier
nur die relative Bewegung. Es kann aber ein Korper relativ gegen
seine Umgebung ruhen, ohne dass sich die auf ihn wirkenden Krafte das
Gleichgewicht zu halten brauchen wie ein Korper, der relativ gegen einen
mit Beschleunigung sich bewegenden Lift ruht.
Wir betrachten nun einen bestimmten Fall, wo die Ursachen der
relativen Bewegung compensirt sind. Ein schwerer Korper sei an einen
diinnen Faden aufgehangt. Wir konnten da meinen, dass gar keine
Bewegungsursachen vorhanden sind. Doch finden wir, dass sofort
Bewesfung- eintritt, wenn wir den Faden entfernen. Es mlissen also
mindestens zwei Bewegungsursachen vorhanden gewesen sein, welche
sich gegenseitig compensirten.
Wenn wir die nach Entfernung des Fadens eintretende Bewegung
analysiren, so finden wir, dass sie, wenn gewisse allgemeine Bedingungen
erfiillt sind, sehr angeniihert immer in derselben Weise vor sich geht.
Diese allgemeinen Bedingungen sind folgende. Die Oberflache des
Korpers darf nicht zu gross gegen dessen Gewicht sein, es darf keine
heftige Luftbewegung um den Korper herum stattfinden, der Faden muss
ohne Erschlitterung durchgeschnitten oder ruhig durch Verbrennung
oder sonst wie vernichtet worden sein. Dieselbe Bewegung tritt auch
ein, wenn wir den Korper anfangs mit der Hand oder einer Zange oder
einer sonstigen Vorrichtung halten und plotzlich ohne Erschiitterung
sich selbst iiberlassen. Das Charakteristische aller dieser Anfangs-
bedingungen besteht darin, dass sammtliche Punkte des Korpers in den
ersten Momenten der Bewegung sehr kleine Geschwindigkeiten haben.
Wir konnen daher anniihernd voraussetzen, dass sammtliche Punkte des
Korpers im ersten Momente der Bewegung keinerlei Anfangsgeschwindig-
292 Ludioifj Boltzmann:
keit batten. Wenn diese Bedingungen erfiillt sind, so lehrt die Erfahr-
ung, dass der Korper stets fast genau nach denselben Gesetzen sich
bewegt, wo immer er in der Niihe der Erdoberflache sicb selbst iiberlassen
worden sei. Die Bewegung bestimmen wir dabei natiirlich einstweilen
relative gegen die Erde. Wenn wir uns nocb auf einen nicbt zu grossen
Theil der Erdoberflache bescliriinken, so ist auch die Ricbtung der
Bewegung iiberall dieselbe ; es ist die des Fadens, der friiher den
Korper trug. Die Erfahrung lehrt nun fiir diese Bewegung die folgen-
den Gesetze. Erstens der Korper bewegt sich parallel zu sich selbst, d. h.
alle Punkte desselben legen in gleichen Zeiten, gleiche und gleichgerich-
tete Wege zuriick. Da also die Balin fiir jeden Punkt dieselbe ist, so
kann man sie als die Bahn des ganzen Korpers bezeichnen. Zweitens, alle
diese Wege sind geradlinig. Drittens, die Geschwindigkeit wachst fort-
wahrend, die Beschleunigung ist jedoch iiberall, zu alien Zeiten und sogar
fiir alle Korper dieselbe. Dass diese Gesetze in der Natur nur mit
grosserer oder geringerer Annaherung realisirt sind, wurde bereits
besprochen,
Wir konnen nun dasselbe Experiment wiederholen, nur dass wir dem
Korper im Momente, wo wir ihn sich selbst iiberlassen einen Stoss geben,
oder sonst me bewirken, dass er schon anfangs eine Geschwindigkeit hat.
Da wir die Satze vom Schwerpunkt und der Drehung der Korper noch
nicht kennen gelernt haben, so miissen wir uns dabei auf die Falle
beschranken, wo sich der Korper wieder parallel zu sich selbst bewegt.
Es wird dies zwar nicht immer eintreten und wir konnen die Bedingungen
dafiir, dass es eintritt noch nicht angeben, aber in vielen Fallen wird
dies stattfinden und diese Falle wollen wir vorlaufig allein betrachten.
In alien diesen Fallen legen wieder alle Punkte des Korpers gleiche
Bahnen zuriick, welche wir also als die Bahn des Korpers bezeichnen
konnen. Die ganze Bewegung kann wieder dahin beschrieben werden,
dass die Beschleunigung immer vertikal nach abwiirts gerichtet und
iiberall zu alien Zeiten und fiir alle Korper dieselbe ist. Da wir nun
gesehen haben, dass die Bewegung, wenn wir sie an verschiedenen Stellen
im Zimmer oder in dessen Umgebung beginnen lassen, immer in ganz
gleicher Weise vor sich geht, so miissen wir schliessen, dass die Beweg-
ungsursache, welche wir Kraft nennen, daselbst iiberall unveranderlich
dieselbe ist. Anderseits ist auch die Beschleunigung unveranderlich
dieselbe, wir konnen daher schliessen, dass wenigstens in diesem speziellen
Falle die Beschleunigung das fiir die Kraft Massgebende ist und well
Dritte Vorlesung. 293
erstere iiberall vertikal nach abwarts gerichtet ist, so sagen wir auf den
Korper wirkt eine constante vertikal nach abwarts gerichtete Kraft die
Schwere.
Dritte Vorlesung.
Um tiefer in die Gesetze der Bewegungen einzudringen, miissten wir
jetzt die nachst einfachsten Falle betrachten. Ein naives Gemiit konnte
da wohl meinen, dass wir nun die Gesetze nach denen ein Grashalm wachst,
untersuchen soUten. Leider aber wissen wir iiber diese noch heute fast
gar nichts. Besser ware es schon die Gesetze der Wirkung gespannter
Schnlire, Federn etc. zu betrachten. Allein auch da treten die Beweg-
ungsgesetze nicht in grosster Einfachheit hervor. Der historische Gang
war vielmehr der folgende. Nachdem Galilei die Bewegungsgesetze
soweit wir sie bisher betrachtet haben, gefunden hatte, suchte Newton
sie vor allem auf die Bewegung der Gestirne anzuwenden und auch von
ihm gilt, was Schiller von Wallenstein sagte: ^^Fiirwahr ihn hat kein
Wahn betrogen als er auf warts zu den Sternen sah." Dem Laufe der
Sterne hat er die Bewegungsgesetze abgelauscht, auf denen alle heute in
der Technik und Machinenlehre benutzten Formeln ja iiberhaupt unsere
ganze moderne Naturkenntnis basirt. Freilich bringt der Ubergang zur
Sternenwelt manche Unbequemlichkeit mit sich. Erstens miissen wir
um einfache Gesetze zu erhalten, unser altes Bewegungssystem, als welches
der Erdkorper diente, verlassen und ein relativ gegen den Fixsternhimmel
sich nicht drehendes Coordinatensystem wahlen. Zweitens ist auch die
Bedingung, das die Planeten sich parallel zu sich selbst bewegen nicht
erfiillt. An ihre Stelle tritt der Umstand, dass ihre Entfernungen vom
Beobachter so gross sind, dass ihre einzelnen Theile iiberhaupt nur schwer
unterschieden werden konnen, so dass wir also in der ersten Annaherung
mit welcher wir uns wieder begniigen, iiberhaupt die Bahnen der ver-
schiedenen Punkte eines und desselben Planeten gar nicht unterscheiden
konnen. Wir konnen also wohl auch annehmen, dass die Gesetze dieselben
waren, wenn die Himmelskorper sich parallel zu sich selbst bewegten.
Wir kommen also hier einestheils dem Begriffe des materiellen Punktes
sehr nahe, da die Ausdehnung der bewegten Korper so klein gegen die
Lange ihrer Bahn ist, dass letztere fiir alle Punkte der Korpers merklich
gleich wird. Anderseits aber sind wir von dieser Idee so weit entfernt
als moglich, da wir es mit Korpern zu thun haben, die nichts weniger als
materielle Punkte, vielmehr oft grosser als unser ganzer Erdkorper sind.
294 Ludwig Boltzmann :
Die Beobachtung und Messung lehrt, dass sich im Weltraume haufig
um einen Centralkorper ein System von Himmelskorpern bewegt, welclie
wir die Trabanten nennen. Wir erhalten die einfachsten Gesetze, wenn
wir die Bewegung der Trabanten auf ein Coordinatensystem beziehen,
dessen Anfangspunkt im Mittelpunkte des betreffenden Centralkorpers
liesft und dessen Axen dreien fest mit dem Fixsternhiramel verbundenen
Geraden stets parallel bleiben. Fiir die Bewegung der Trabanten gelten
erfahrungsgemass die drei Keppler'schen Gesetze. Da beim freien Falle
die Beschleunigung eine so wichtige Rolle spielte, so wollen wir auch
in diesem Falle die Beschleunigung berechnen, welche irgend ein Tra-
bant in seiner Bewegung erfahrt. Diese Rechung ist sebr bekannt und
ganz leicht. Es hat sie Kirchhoff in seinen Vorlesungen iiber Mechanik
in sehr eleganter Form durchgeftihrt. Man findet aus dem ersten und
zweiten Keppler'schen Gesetze, dass sie fiir jeden Trabanten zu jeder Zeit
gegen den Centralkorper gerichtet und dem Quadrate des Abstandes r
k
von demselben verkehrt proportional, also in der Form — darstellbar ist.
Aus dem dritten Keppler'schen Gesetze ergibt sich ausserdem, dass die
Constante k von Centralkorper zu Centralkorper verschieden ist, aber
fiir alle Trabanten eines und desselben Centralkorpers denselben Wert
hat. Da wir schon bei der Schwere die Beschleunigung als das mass-
gebende fiir die Bewegungsursache oder Kraft erkannt haben, so
wollen wir auch hier sagen, der Centralkorper iibt auf jeden Trabanten
eine Kraft aus, welche die Richtung der vom iSIittelpunkte des Trabanten
gegen den des Centralkorpers gezogenen Geraden hat und der Lange
dieser Geraden verkehrt proportional ist. Diese ist einstweilen sonst
nichts als ein anderer Ausdruck fiir die Thatsache des Vorhandenseins
dieser Beschleunigung. Newton hat diesen Satz sofort enorm verallge-
meinert indem er annahm, dass iiberhaupt jeder Himmelskorper auf jeden
andern ja jedes materielle Theilchen auf jedes andere eine solche Kraft
ausiibt. Wenn daher ein Himmelskorper mehreren andern so nahe ist,
dass er von ihnen eine merkliche Einwirkung erfahrt, so haben wir den
Fall, dass er gleichzeitig aus verschiedenen Ursachen verschiedene Be-
schleunigungen nach verschiedenen Richtungen erfahrt. Da wir die
Beschleunigung durch einen Vector dargestellt haben, so ist es nicht die
einzig notwendige, aber doch bei weitem die nahe liegendste, einfachste
Annahme, dass sich diese Beschleunigungen me Vectoren addiren. In
der That zeigt sich, dass man unter dieser Annahme immer Ubereinstim-
Dritte Vorlesimg. 295
mung mit der Erfahrung erhalt. Es ergeben sicli die Storungen der Plane-
ten untereinander, der Monde durch die Sonne und durch die Planeten in
genauer Ubereinstimmung mit der Erfahrung. Man kann jetzt auch den
Horizont erweitern und alle Himmelskorper auf ein und dasselbe mit
dem Fixsternhimmel fest verbundene Coordinatensystem beziehen und
erhalt auch die Bewegung der Centralkorper gegen dieses Coordinaten-
system in Ubereinstimmung mit der Erfahrung. Die Schwere erweist
sich als identisch mit der Anziehung des Erdkorpers auf den schweren
Korper. Schliesslich zeigen die Erscheinungen der Ebbe und Flut, die
Versuche von Cavendish, Maskelyne, Airy etc. die Richtigkeit der Aus-
dehnung des Newton'schen Gesetzes auf die irdischen Korper. Da die
wirkliche Beschleunigung immer die Vectorsumme der verschiedenen
von den wirkenden Korpern erzeugten Beschleunigung ist, so folgt jetzt
als spezieller Fall des Newton'schen Gesetzes, dass ein Korper, welcher
von alien iibrigen so weit entfernt ware, dass keiner derselben eine Wirk-
ung auf ihn ausiiben wiirde, zu alien Zeiten die Beschleunigung Null
erflihre. Wir erhalten also erst jetzt das Tragheitsgesetz. Selbstver-
standlich ist hiemit iiber die Ursache der Newton'schen Kraft, ob die-
selbe eine direkte Fernwirkung ist oder durch ein Medium vermittelt
wird, nicht das mindeste prajudicirt. Wir konnten auch jetzt schon den
Begriff der Masse ableiten. Die Massen zweier Centralkorper wiirden
sich ja wie die ihnen entsprechenden Werte der Constanten h des Gravi-
tationsgesetzes verhalten und durch den Cavendish'schen Versuch konnte
diese Definition auch auf irdische Korper ausgedehnt werden. AUein wir
wiirden da die Proportionalitat der Constante k mit der als Tragheits-
widerstand definirten Masse vorwegnehmen, was offenbar ein logischer
Fehler ware. Wir miissen daher zum Begriff e der Masse auf ganz an-
derem Wege zu gelangen suchen. Wir haben bisher als das Massge-
bende fiir die Kraft die Beschleunigung betrachtet. Es konnte nun als
das einfachste erscheinen, die Grosse der Beschleunigung, welche ein
Korper durch einen andern erfahrt, einfach als die Grosse der Kraft zu
bezeichnen, welche der letztere auf den ersteren ausiibt. Es geschieht
dies auch manches Mai und man bezeichnet die so definirte Kraft als die
beschleunigende Kraft. Allein im AUgemeinen ist es besser einen andern
Begriff einzufiihren. Wir denken namlich beim Worte Kraft in erster
Linie an die Muskelanstrengungen, welche wir ausiiben konnen. Nun
liegt freilich kein Grund vor, ja es ware ganz verkehrt anzunehmen, dass
jedes Mai, wenn unbelebte Korper Krafte aufeinander ausiiben etwas
296 Ludwig Boltzmann :
vorhanden sein miisse, was diesen Muskelanstrengungen irgendwie ent-
spricht. AUein es wird sich doch empfehlen, wenn wir die Bezeich-
nungen so walilen, dass sie sich den durch diese Muskelanstrengungen
erworbenen Begriffen moglichst gut anschliessen. Wir sahen, dass alle
Korper durch die Schwere die gleiche Beschleunigung erfahren. Wiirden
wir nun diese ohne weiteren Factor als Mass der Kraft wiihlen, so wiire
die Kraft, welche die Schwere auf sie ausiibt, (das Gewicht) fiir alle
Korper dasselbe. Nun lehrt aber die tagliche Erfahrung, dass die Mus-
kelanstrengung welche wir brauchen, um den Fall aufzuheben, fiir ver-
schiedene Korper sehr verschieden ist. Wollen wir daher mit unseren Vor-
stellungen im Einklang bleiben, so miissen wir sagen, dass auch die Schwere
auf die verschiedenen Korper sehr verschiedene Kriifte ausiibt, dass aber
die Korper von grosserem Gewichte dieser beschleunigenden Wirkung der
Schwere einen grosseren Widerstand, den Tragheitswiderstand, die Masse,
entgegensetzen, so dass erst in folge beider Umstande zusammen alle
Korper die gleiche Beschleunigung erfahren. Um die Masse in dieser
Weise als Tragheitswiderstand zu defiuiren, miissen wir an verschiedene
Korper die gleiche Kraft anbringen. Das Verbal tnis ihrer Massen kon-
nen wir dann als das verkehrte Verhaltnis der Beschleunigungen defi-
niren, die sie durch gleiche Krafte erhalten. Aber darin liegt eben die
grosste Schwierigkeit wie man die Gleichheit der Krafte, wenn diese auf
verschiedene Korper wirken, ohne logischen Fehler feststellen soil. Man
konnte zwei Korper dem Zuge gleich beschaffener gleich gespannter
Schniire oder elastischer Federn unterwerfen. Allein da miisste man
erst durch complicirte der Erfahrung entnommene Argumente als wahr-
scheinlich hinzustellen suchen, dass gleich beschaffene Schniire auf zwei
ganz verschiedene Korper dieselben Krafte ausiiben, was gewiss nicht
a priori evident ist. Wir konnten auch nach Mach einfach den Satz
der Gleichheit der Wirkung und Gegenwirkung postuliren. Wenn dann
bloss zwei Korper in Wechselwirkung begriffen sind, so ware die Gleich-
heit der Krafte, welche auf beide Korper wirken evident. Wenn sie sich
zudem nur Parallelverschiebungen ertheilen, so ware das Verhaltnis
ihrer Massen einfach zu definiren, als das verkehrte Verhaltnis der Be-
schleunigungen, welche an ihnen zu beobachten sind. Allein bei der
Wirkung dazwischen gebrachter Schniire, Faden etc. haben wir eigent-
lich schon immer mehr als zwei in Wechselwirkung begriffeue Korper
und es wiirde auch die Deformation dieser Zwischenkorper in Betracht
zu Ziehen sein. Der von Mach ansrenommene Fall konnte also in reiner
Dritte Vorlesimg. 297
Weise eigentlich nur bei directer Fernwirkung vorkommen und es ware
sehr misslich, wenn man vom rein empirisclien Standpunkte aus die
directe Fernwirkung a priori annehmen miisste. Streintz sucht eine
einwurfsfreie Definition in folgender Weise zu gewinnen, Er denkt
sich irgend ein System beliebiger Korper. In demselben kommen zwei
Korper K^ und K^ vor. Diese ruhen im ersten Augenblicke und beginnen
sich dann mit Beschleunigung aber jeder parallel zu sich selbst zu be-
wegen. Es soil nun die Bewegung beider Korper dadurch aufgehoben
werden konnen, dass man sie starr mit einander verbindet. Dies ver-
wendet er als Kriterium, dass friiher auf jeden genau die gleiche Kraft
wirkte, well sich beide Krafte durch blosse starre Verbindung jetzt auf-
heben. Er nennt diese Begriffsbestimmung der Gleichheit der Kraft die
statische. Sie hat das fiir sich, dass sie das Princip der Gleichheit der
Wirkung und Gegenwirkung involvirt, wie man sofort sieht, wenn man
den speziellen Fall betrachtet, dass das ganze System bloss aus den zwei
auf einander wirkenden Korpern K^ und K^ besteht. Sie hat aber doch
audi manches Willkiirliche. Dass durch die starre Verbindung die Wirk-
ung der librigen Krafte nicht gestort wird, kann wieder hochstens
erfahrungsmassig wahrscheinlich gemacht werden. Dass die Verbin-
dungskrafte sich zu den librigen addiren, setzt schon gewisse Satze der
Statik voraus. Noch grosser wiirden die Schwierigkeiten, wenn, die
Korper K^ und K^ anfangs in Bewegung begriffen wJiren. WoUte man
da nicht von vornherein annehmen, dass die Krafte bloss von der rela-
tiven Lage abhangen, durch den aus der plotzlichen starren Verbindung
resultirenden Stoss nicht gestort werden und Ahnliches, so miisste ihre
Beschleunigung durch eine die Bewegung gestattende und auf beide
Korper bloss beschleunigend wirkende plotzlich eingeschaltete Feder
aufgehoben werden. Halt man einmal an der Streintz'schen Vorstellung
fest, so hat die Definition der Massenverhaltnisses weiter keine Schwierig-
keit. Die Massen der beiden Korper K^ und K^ verhalten sich dann
umgekehrt, wie die Beschleunigungen, die sie im ersten Falle, wo keine
starre Verbindung vorhanden war, erhielten, da ja damals auf beide
gleiche Krafte wirkten. Natiirlich ist sowohl bei der Mach'schen als bei
der Streintz'schen Definition noch immer erforderlich, sich auf besondere
Erfahrungssatze zu berufen, vermoge welcher das Massenverhaltnis
zweier Korper immer gleich ausfallt, unter was immer fiir Umstanden
man den hiezu dienenden Versuch angestellt haben mag und vermoge
welcher das Verhaltnis der Massen der Korper K^ and K^ stets gleich
298 Luclwig Boltzmann :
dem Producte der beiden Massenverhaltnisse der Korper K-^^ K^ und K^^
K^ ist.
Zii bemerken ist noch, dass wir nur das Verhaltnis zweier Massen bisher
definirt haben. Um die Masse durch eine Zahl auszudriicken, miissen
wir irgend eine Masse willkiiiiich als eine neue Einheit wahlen. Von
alien Grossen, welche daher durch Zalilen ausgedriickt werden, deren
Grosse von der Wahl der Masseneinheit abhangig ist, werden wir sagen
dass sie gewisse Diinensionen beziiglich der Masse haben. Haben wir den
Begriff der Masse in der einen oder andern Weise festgestellt, so hat die
Definition der Kraft im gewohnlichen Sinne oder wie man auch sagt, der
bewegenden Kraft keine Schwierigkeit mehr. Dieselbe ist das Product
der Masse in die Beschleunigungen und hat daher beziiglich der Masse
die Dimension eins. Da sich die Beschleunigungen wie Vectoren addi-
ren, so gilt dies auch von den Kraften, wenigstens insoweit wir diese
bisher betrachtet haben. Dieser Satz vom Kraftenparallelogramm sowie
die iibrigen bisher entwickelten Satze, konnen nun auch auf die Statik
und Dynamik der durch gespannte Faden oder durch Federn erzeugten
Druck und Zugkrafte iibertragen werden. Natiirlich zunachst bloss in
dem idealen Falle, dass die Bewegung der einzelnen Theile der Faden und
Federn nicht betrachtet wird und dass die bewegten Korper sich stets
parallel zu sich selbst bewegen. Es konnte so z. B. die Mechanik der
Atwood'schen Fallmaschine mit Hilfe des bisher Entwickelten ohne
weiteres discutirt werden.
Aus dem Umstande, dass sich das Newton'sche Gravitationsgesetz in
symetrischer Weise beziiglich beider wirkender Korper aussprechen muss
und dass die Anziehungsconstante K fiir alle Trabanten desselben Cen-
tralkorpers gleich ist, leitet man leicht ab, dass diese gleich dem Producte
der Massen der beiden wirkenden Korper in eine fiir das ganze Universum
constante Grosse sein muss, wahrend die Thatsache, dass alle Korper
durch die Schwere die gleiche Beschleunigung erhalten, schon lehrt, dass
das Gewicht der Masse proportional sein muss.
AVir sind aber noch sehr weit davon entfernt aus den bisher entwickel-
ten Grundlagen sammtliche Siitze der Mechanik ableiten zu konnen.
Wir haben ja bisher bloss die Bewegung eines festen Korpers parallel zu
sich selbst betrachtet und haben den wichtigen Begriff des Angriffspunk-
tes einer Kraft noch gar nicht gewonnen. Um diesen zu erhalten, um die
Drehung der starren Korper, die Deformationen der elastischen und die
Bewegungen der fliissigen behandeln zu konnen, miissen wir von neuen
Dritte Vorlesung. 299
Thatsachen ausgehen. Wenn ein Faden an einem Korper befestigt ist
oder eine Feder auf eine einzige Stelle desselben driickend wirkt, so gibt
es stets eine ganz kleine Partie des Korpers, welche zunachst von der
Kraft afficirt wird. Losen wir diese los und stellen einen kleinen
Zwischenraum zwisclien ihr und den iibrigen Theilen des Korpers her,
so wird derselbe erst wieder afficirt, wenn dieser Zwischenraum durch
die Bewegung des kleinen abgetrennten Theiles sicli ausgefiillt hat.
Wir nennen daher diesen Theil die Angriffstelle und konnen sie wieder
zu einem Angriffspunkte idealisiren. Wir mlissen nun noch die bekann-
ten Satze iiber die Versetzbarkeit von Kraften an starren Korpern als
idealisirte Erfahrungsthatsachen beifiigen. Mittelst derselben konnen
wir dann in ebenfalls hinlanglich bekannter Weise die Satze iiber das
Gleichgewicht von beliebigen Kraften, welche auf einen starren Korper
wirken, die Satze von den statischen Momenten ableiten. Wir schlagen
hier insoferne einen analogen Weg ein, wie Streintz bei der Definition
der Masse, als wir von der Statik ausgehen und erst von dieser zur
Dynamik gelangen. Die Satze von den statischen Momenten haben wir
da freilich zunachst bloss fiir eine begrenzte Zahl von Kraften bewiesen,
von denen jede nur auf einen einzelnen Punkt des Korpers wirkt. Wir
miissen dazu noch die Annahme hinzufiigen, dass man im Falle, wo die
Krafte den Korper oder einen ausgedehnten Theil desselben als Gauzes
anfassen die Sache immer so ansehen kann, als ob sie auf sehr viele
respective unendlich viele Punkte seiner Oberflache oder seines Innern
gerade so wirken wtirden, als ob an jedem dieser Punkte eine ein wenig
gespannte Schnur oder eine ein wenig driickende Feder befestigt ware.
So muss mann z. B. von der Schwere annehmen, das sie gleichmassig
auf alle Punkte des schweren Korpers wirkt. Einen andere Weg, auf
welchem man den Ubergang von der Bewegung parallel zu sich selbst
zur Drehbewegung versuchen konnte, will ich hier nur ganz kurz
andeuten. Wir konnen aus dem Principe der Erhaltung der lebendigen
Kraft folgenden Satz ableiten. Wenn auf einen festen Korper eine Kraft
wirkt, die ihn nur parallel zu sich selbst zu bewegen sucht, so muss
immer eine ihrer Richtung parallele Gerade, welche wir die Angriffslinie
nennen woUen, von soldier Beschaffenheit existiren, dass wenn man einen
beliebigen Punkt des festen Korpers, welcher auf derselben liegt, festhalt,
der Korper ins Gleichgewicht kommen muss. In gleicher Weise kann
man beweisen, dass, wenn zwei feste Korper K^ und K^ so in Wechsel-
wirkung begriffen sind, dass jeder dem andern nur eine Bewegung parallel
Boo Ludwig Boltzmann :
zu sich selbst ertheilt, Wirkung und Gegenwirkung gleich sein muss und
die Angriffslinien zusammenfallen mlissen. Denkt man sich dann einen
Punkt A der gemeinsamen Angriffslinien festgehalten, so muss das ganze
System ins Gleichgewicht kommen. Jeden solchen Punkt konnen wir als
Angriffspunkt der Kraft betrachten. An diesen Begriff des Angriffs-
punktes, konnen dann ebenfalls die Siitze von den statischen Momenten
gekniipft werden.
Hat man einmal diese Siitze so oder so gewonnen, so muss man zur
Zerlegbarkeit der Korper in Volumelemente libergehen. Man fiihrt
wieder als Erfahrungssatz an, dass sehr viele Korper, wenigstens mit
geniigender Anniiherung in zwei Korper von je der halben Masse zerlegt
werden, wenn man sie in zwei Theile von gleichem Volumen zerschneidet.
Analog, wenn man sie in drei gleiche Theile theilt u. s. f. Denkt man
sich dies ins Unendliche fortgesetzt, so gelangt man zu einem Satze,
den man dahin aussprechen kann dass diese Korper aus unendlich vielen
Volumelementen dv bestehen und die in jedem Volumelemente enthaltene
Masse dm = pdv ist. Bei andern inhomogenen Korj^ern gilt dies wenig-
stens nahezu fiir jeden kleinen Volumtheil des Korpers, so dass wir die-
selbe Formel anwenden konnen, wenn wir p als von Punkt zu Punkt
veriinderlich betrachten.
Was nun die Krafte anbelangt, welclie die Volumelemente fester
Korper aufeinander ausliben, so muss man annehmen, dass jedes Volum-
element nur auf die unmittelbar benachbarten wirkt und dass es auf alle
der Trennungsflache anliegenden Punkte Krafte ausiibt, welche gerade
so wirken, als ob daran ziehende gespannte Fiiden oder driickende, auf-
gestiitzte Stabe befestigt waren. Wenn die Trennungsflache eben und
geniigend klein ist, so muss man zudem annehmen, dass diese Krafte
gleichmassig auf alle der Trennungsflache anliegenden Punkte wirken.
Diese Satze konnen wol kaum direct erfahrungsmassig bestatigt werden
und finden ihre Rechtfertigung nur in der nachherigen Ubereinstimmung
der aus ihnen entwickelten Siitze mit der Erfahrung. Wendet man den
Satz von den statischen Momenten auf ein Volumelement an, so findet
man, dass im Falle des Gleichgewichtes die auf ein zur a:-axe senkrechtes
Fliichenelement in der ?/-Richtung wirkende Kraft gleich sein muss der
auf ein gleiches zur ?/-Richtung senkrechtes Fliichenelement in der
a;-Richtung wirkenden Kraft, was wir den Satz X nennen wollen. Zu
den bisher aufgestellten Annahmen welche Avir uns als durch die Erfahr-
ung geniigend motivirt dachten, sind noch die folgenden hinzuzunehmen.
Dritte Vorlesung. 301
Erstens, die elastische Kraft ist bloss von der augenblicklichen Gestaltver-
anderung des betreffenden Korpers, nicht von den friiheren Zustanden
desselben, noch auch von der Geschwindigkeit seiner Theilchen abhangig.
Zweitens, jedes Volumelement bewegt sich nach den Gesetzen, welche wir
bisher bloss fiir die Bewegung parallel zu sich selbst abgeleitet haben.
Unter diesen Annalimen erhalt man dann sofort die Gleichungen der
gewobnliclien Elasticitiitslehre. Dieselben gelten natiirlich wieder nur
fiir einen idealen festen Korper, alle festen Korper zeigen innere Reibung
und elastische Nachwirkung, welche wir bisher ausgeschlossen haben.
Auch der Satz, welchen wir den Satz X nannten, ist keineswegs a priori
evident. Lord Kelvin hat sich einmal den Lichtather, sonst ganz mit den
Eigenschaften begabt gedacht, welche wir an festen Korpern wahrnehmen,
nur dass er die Richtigkeit dieses Satzes X fallen liess. Wir woUen uns
hier nicht in eine Discussion einlassen ob durch die Annahme Lord
Kelvins das Verhalten des Lichtathers erkliirt werden kann. Es geniigt
uns, dass derselbe ohne alle inneren Widersprliche Bewegungsgleichungen
fiir die Volumelemente eines festen Korpers ausarbeiten konnte, fiir
welchen der Satz X nicht gilt. Wir wollen jedoch vorliiufig bei Korpern
stehen bleiben, welche den idealen Gleichungen der Elasticitatslehre
geniigen. Wenn solche Korper so wenig deformirbar sind, dass man sie
als Starr betrachten kann und wenn durch beliebige Systeme derselben
beliebige Bedingungsgleichungen realisirt sind, so kann man jetzt leicht
nachweisen, dass fiir dieselben das vereinigte Princip der virtuellen
Geschwindigkeiten und d'Alembert's gelten muss. Denn wenn man
alle Krafte auch die elastischen ins Auge fasst, so verschwindet jedenfalls
die Summe
a
(.g-x)i»t(.5-i')%+(,g-z)s.;
da jedes Glied dieser Summe einzeln verschwindet. Da aber die Wirkung
immer gleich der Gegenwirkung ist, so miissen die Glieder dieser Summe,
welche sich auf die Wechselwirkung der Volumelemente beziehen separat
verschwinden, wenn diese starren Korpern angehoren also keiner relativen
Lagenanderung fahig sind, wahrend bei bloss einseitigen Verbindungen
die bekannten Ungleichungen abgeleitet werden konnen. Dies kann
auch auf Verbindungen iibertragen werden, die nur theilweise starr sind
z. B. unausdehnsame Flachen, Faden etc. ; denn diese konnen immer als
Grenzfall sehr diinner elastischer Korper betrachtet werden. Man erhalt
302 Ludwig Boltzmann :
so das vereinigte Princip der virtuellen Verschiebungen und d'Alembert's
in der gewohnlichen Form. Erst aus diesem Principe konnen wir jetzt
die Satze von der Bewegung des Schwerpunkts, vom Triigheitsmomente
etc. ableiten. Diese Siitze erscheinen daher in unserem Systeme erst an
dieser Stelle. Es kann dies nicht anders sein ; denn darin besteht ja das
Wesen der inductiven Methode, dass wir nicht den Begriff des materiellen
Pimktes als eines unausgedehnten mit Masse begabten Korpers postuliren,
sondern die Schliisse, welche man sonst mit Hilfe dieses Begriffes macht,
erst ausfiihren, wenn wir zur Vorstellung des Volumelementes gekommen
sind, welche wir eher der Erfahrung entnehmen zu konnen glauben, als
die des materiellen Punktes. Wir konnen dann diese Siitze erst erhalten,
wenn wir die Wechselwirkung der Volumelemente behandelt haben.
Wir mussten freilich schon friiher an zwei Stellen vom Begriffe des
mathematischen Punktes Gebrauch machen, namlich als wir die Beweg-
ung eines einzigen hervorgehobenen Punktes eines Korpers betrachteten
und als wir Krafte fingirten, welche an einem einzigen Punkte eines
Korpers angreifen. AUein da war die Abstraction doch viel einfacher
und klarer, als wenn wir das Ideal eines unausgedehnten mit Masse
begabten Korpers bilden und dessen Drehung einfach vernaclilassigen,
ohne dass wir die Gesetze der Drehung vorher kennen gelernt haben.
Manche Satze konnten wir allerdings auch auf einem andern als dem
eingeschlagenen Wege gewinnen. Ein Analogon des Schwerpunktsatzes
konnten wir z. B. ableiten, indem wir ein System von ausgedehnten
Korpern betrachten wiirden, zwischen denen innere Krafte thatig sind
und auf welche auch aussere Krafte wirken, welche ihnen aber alle nur
Bewegungen parallel zu sich selbst ertheilen. Nimmt man dazu noch die
Annahme, dass fiir die innere Krafte Wirkung und Gegenwirkung immer
gleich ist, so wiirde ein dem Schwerpunktsatze ahnlicher Satz flir ein
solches System in Wechselwirkung begriffener ausgedehnter Korper
folgen.
Die Krafte, welche in Fliissigkeiten wirken, konnen als ein spezieller
Fall, der in elastischen Korpern wirkenden betrachtet werden und sie
konnen daher ebenfalls nach der im bisherigen auseinandergesetzten
Methode gewonnen werden. Die Gestaltanderungen der Fliissigkeiten
konnen dann durch die Bewegung der Volumtheile derselben dargestellt
werden, welche die entwickelten Gesetze befolgt ; nur dass die Deforma-
tion des Korpers als Ganzes jetzt eine beliebig grosse sein kann.
Wir haben hiemit das Gebiet der eigentlichen mechanischen Erschein-
Dritte Vorleswig. 303
ungen erschopft. Bei den dissipativen Erscheinungen (elastische Nach-
wirkung, Reibung etc.) spielt bereits die entwickelte Warme eine Rolle.
Wir konnen natiirlich die Form der friihern Gleicliungen wahren, indem
wir zu den bisher abgeleiteten Kraften noch Glieder von solcher Be-
schaffenheit hinzu addiren, dass deren Summe genau gleich dem Werte
der mit der Masse multiplicirten Besclileunigung wird. Diese Zusatz-
glieder konnen wir dann immer als Reibungskraft, Mittelswiderstands-
kraft etc. bezeichnen, doch hat diese Darstellung einen rein formalen
Wert, wenn die Zusatzglieder in ganz complicirter Weise von der
Bewegungsgeschwindigkeit, den friihern Zustanden etc. abhangen. Es
bietet die Molekulartheorie da entschieden mehr Anschaulichkeit, da sie
die Zusatzglieder doch durch langsame Drehung der Molekiile in neue
Ruhelagen, Umsetzung der sichtbaren Bewegung in Molekularbewegung
etc. einigermassen versinnlichen kann. Das Princip der virtuellen Ver-
schiebung behalt dann natiirlich, so lange es auf das Gleichgewicht
ruhender Korper angewendet wird, seinen Sinn, da bei der Ruhe dissipa-
tive Vorgange fehlen. Aber das d'Alembert'sche Princip ist auch zu
einer leeren Formel herabgesunken, so bald sich in den Ausdriicken fiir
die Kriifte Glieder finden, welche selbst wieder von der Bewegung, von
den vorhergegangenen Zustanden der Korper etc. abhangen. Uber die
Darstellung der elektrischen und magnetischen Erscheinungen will ich
hier nur bemerken, dass dieselbe ebenfalls in die Form der mechanischen
Gleichungen gebracht werden kann und muss, sobald diese Erscheinungen
von Bewegungen ponderabler Korper begleitet sind. Des Naheren hier-
auf einzugehn, ist jedoch nicht meine Absicht.
Ich woUte in dem Bisherigen keineswegs eine consequente in sich
abgeschlossene Darstellung der Mechanik vom inductiven Standpunkt
geben. Ich woUte vielmehr bloss die Wege andeuten, auf denen eine
solche vielleicht gewonnen werden konnte und namentlich die Schwierig-
keiten aufdecken, mit denen ihre Durchfiihrung verkniipft ist, wenn man
sich bestrebt, das innere Bild ebenso klar hervortreten zu lassen und
consequent durchzuflihren, wie dieses bei der deductiven Behandlung
moglich ist. Ich komme daher zu dem Resultate, dass unter den bis-
herigen Darstellungsversuchen der Mechanik die deductiven, wie die von
Hertz und die von mir in meinem citirten Buche gemachte vorzuziehen
seien. Da aber diese deductive Darstellung wie schon zu Anfang
gezeigt wurde, den Mangel hat, dass sie so lange Zeit hindurch gar
nicht an die Erfahrung ankniipft und vielfach den Schein des Willkiir-
304
Ludwig Boltzmann :
lichen erweckt, so wiirde es mich sehr freuen, wenn es jemanden gelange,
der deductiven Darstelluug eiue inductive an die Seite zu stellen, welche
gleich einfach und naturgemass vorginge und doch das innere geistige
Bild in gleicher Deutlichkeit und Consequenz hervortreten liesse. Es
Vierte Vorlesung. 305
ware dies wohl in einer kurzen Abhandlung kaum moglich, soudern nur in
einem grosseren Buche, wo man den Grundprincipien sogleich die An-
wendung auf alle speziellen Fiille folgen lassen konnte. Denn erst an der
Moglichkeit der exacten Darstellung aller moglichen speziellen Fiille
erprobt sich die Klarheit und Consequenz der Bilder, wie sich das am
besten an der Hertz'schen Darstellung zeigt, wo diese Anwendung auf
spezielle Fiille fehlt. Sollten sich aber die Liicken, die sich in meiner
gegenwartigen Darstellung finden, nicht ausfiillen lassen, so wiirde mich
auch dies freuen, denn es wiirde den definitiven Sieg der deductiven iiber
die inductive Behandlungsweise bedeuten. Ich mochte gewissermassen
die Vertreter der inductiven Richtung einladen, alle Fehler, die sich in
meiner gegenwartigen Darstellung finden aufzudecken, die Moglich-
keit der genauen Durchfiihrung aller Schlussweisen, die ich hier nur
kurz angedeutet habe, zu zeigen und ihre besten Kriifte einzusetzen in
dem Wettkampfe mit der deductiven Darstellung, damit beide mit ein-
ander verglichen werden konnen und sich im Wettstreite stets ausbilden
und vervoUkommnen.
Da der Energiebegriff nicht nur in der Mechanik, sondern in der
ganzen Naturwissenschaft eine so wichtige RoUe spielt, so waren auch con-
sequente Darstellungen der Grundprincipe der Mechanik vom Standpunkte
der Energetik hochst erwiinscht, welche also nicht von den Begriffen der
Beschleunigung und Kraft sondern von denen der lebendigen Kraft und
des Potentiales auszugehen hatten. Doch miissten die betreffenden
Bilder auch nach der deductiven oder inductiven Methode durchaus klar
consequent und einwurfsfrei entwickelt werden und es miissten vollkom-
men pracise Regeln gegeben werden, wie dieselben eindeutig auf alle
speziellen Falle anzuwenden sind, ohne dass die Kenntnis der alten
Mechanik dabei vorausgesetzt wird.
ViEETE VOKLESUNG.
Die vierte Vorlesung begann der Vortragende mit der Vorzeigung des
Modells fiir die Maxwell'sche Theorie der Elektricitiit und des Magnetis-
mus, welches in dessen Buch ^^Vorlesungen iiber Maxwells Theorie der
Elektricitiit und des Lichtes erster Theil " beschrieben ist. Es wurden
alle dort erwahnten Experimente mit gutem Erfolge durchgefiihrt.
Hierauf gab er noch folgende Ubersicht iiber die das Princip der kleins-
ten Wirkung und das Hamilton'sche Princip umfassenden Gleichungen.
306 Ludwig Boltzmann:
Wenn wir die FiiUe einseitiger Verbindungen ausschliessen, so wird
das vereinigte Princip der virtuellen Verscliiebungen uud d'Alemberts,
wie wir sahen durch eine Gleichung ausgedriickt, welche wir erhalten,
wenn wir den Ausdriick auf Seite 36 gleich Null setzen. Fiibrt man
darin generalisirte Coordinaten ein und setzt Einfachheit halber voraus,
dass eine Kraftfunction V besteht, welche aber die Zeit enthalten kann,
so transformirt sich dieselbe in folgende Gleichung
dt dp dp
wobei p irgend eine generalisirte Coordinate, q das dazu gehorige Mo-
ment, T die gesammte kinetische Energie ist. Wenn jede beliebige
Coordinate p zu jeder beliebigen Zeit t eine beliebige Variation Sp erfahrt,
so kann man die letzte Gleichung mit 8p multipliciren und beztiglich aller
p summiren. Im speciellen Falle, dass alle 8p integrable Functionen der
Zeit sind, kann man noch mit dt multipliciren und iiber eine beliebige
Zeit (von tQ bis <) integriren ; nach partieller Integration der dq/dt ent-
haltenden Glieder folgt in dieser Weise :
sf\T-V)dt=2(q8p-q,Sp,^ (1)
wobei sich rechts die erstern Grossen auf die obere die letztern auf die
untere Integrationsgrenze beziehen.
1. Hamiltons Princip der stationaren WirTcung.
Aus der Fundamentalgleichung 1) folgt das Princip der stationaren
Wirkung, wenn man die Grenzen des Integrals und die Coordinaten-
werte fiir dieselben als unveranderlich voraus setzt. Dann ergibt sich,
wenn man setzt
A t — t.
folgende Gleichung :
Sn = Oder 5^=0.
O oder W haben also fiir die Bewegung dieselbe Bedeutung, wie V fiir
das Gleichgewicht in der Ruhe. Die Bedingungen, welche den Grenz-
wert von XI oder W unter den geschilderten Umstanden angeben, sind
mit den Bewegungsgleichungen identisch, wesshalb Helmholtz diese Gros-
Vierte Vorlesung. 307
sen als kinetisches Potential bezeichnet. Fiir das Gleichgewicht in der
Ruhe, bestimmen diese Bedingungen einen Grenzwert von F", da dann
T =0 und V^fon der Zeit unabhangig ist. Der Satz, dass fiir das Gleich-
gewicht, F'ein Grenzwert ist, ist also ein ganz specieller Fall des Satzes
vom kinetische Potentiale oder des Hamilton'schen Princip der station-
aren Wirkung, wie dieser auch genannt wird.
2. Hamiltons Princip der variirenden Wirkung.
Wir setzen in Gleichung 1) einmal nur die untere dann nur die obere,
dann nur den Wert einer Coordinate fiir die untere, endlich diesen
Wert fiir die obere Grenze des Integrales als veranderlich voraus ; es
folgen sofort die Hamilton'schen partiellen Differentialgleichungen :
Es soil nun V die Zeit nicht enthalten, also die Energie T+ V sich mit
der Zeit nicht andern. Wenn man dann in Gleichung 1) die Grenzen
als variabel betrachtet, so transformirt man sie nach einigen Zwischen-
rechnungen leicht in die folgende :
2BCTdt = rS(r-f V}dt + ^(qBp - q^Bp^-) (2)
wobei aber die Sp jetzt unter gleichzeitiger Variation der Grenzen fiir
die Zeit und der Bewegung zu bilden sind.
3. Das alte Princip der kleinsten Wirkung.
Setzt man in Gleichung 2) die Coordinatenvariationen fiir die Gren-
zen von t gleich Null und nimmt ausserdem an, dass die Variation der
Bewegung ohne Energiezufuhr geschieht also S(Th- F)= ist, so folgt
also die alte Form des Princips der kleinsten Wirkung, welches in
mancher Beziehung specieller, in so fern aber wieder allgemeiner ist,
als das Princip der stationaren Wirkung, als es die Bewegungszeit als
veranderlich betrachtet.
308 Ludwig Boltzmann :
4. Analogien mit dem zweiten Hauptsatze.
Wir wollen annehmen, class das letzte Glied der Gleichung 2)
verschwindet. Es gilt dies nicht bloss, wenn an den Grenzen fiir die
Zeit hp ■= hpf^ = ist, sondern audi wenn die Bewegung periodisch ist und
t — t^ die Dauer dieser Periode ist. Es gilt auch wenn die Verschiebungen
sammtlicher materiellen Punkte des Systemes in folge der Variation der
Bewegung senkrecht auf der augenblicklichen Geschwindigkeitsrichtung
derselben steht. Bisher waren die hp ganz willkiirliche Variationen.
Wir wollen sie nun in folgender Weise erzeugt denken. 1. Mit dem
Systeme, auf welches sich die Gleicliung 2) bezieht, soil ein zweites Sys-
tem verbunden sein, welches mit dem ersten in Wechselwirkung steht und
letzteres soil eine unendlich kleine Bewegung machen. 2. Ausserdem
soil dem ersten Systeme eine unendlich kleine lebendige Kraft S^zugefiihrt
werden. Die in der Gleichung vorkommende Grosse h F'ist bloss die Veran-
derung von F'in folge der Lagenanderung der Punkte des ersten Systems.
Sei S'F'die in Folge der Lagenanderung des zweiten Systems, so ist h^V
die Arbeit der vom ersten auf das zweite System wirkenden Kriifte. Sie
muss mit der zugefiihrten Energie hQ zusammen die gesammte Anderung
hE der Energie des ersten Systems geben. Es ist also hE= SQ + B'V.
Anderseits ist SjE'= 8T+ BV + B' V, da 8^ die Anderung der kinetischen,
SV-\- 8'V die Gesammtiinderung der potentiellen Energie ist. Aus bei-
den Gleichungen folgt 8Q = 8 (T -{- V). Setzen wir
_ CsQdt _ r
Tdt
BQ^^-^ und T =
t — t^ I — Iq
so folgt aus Gleichung 2) unter den gemachten Annahmen sofort
T
lognat/J 'Tdt\
wo die Analogic mit dem zweiten Hauptsatze deutlich zu Tage tritt.
Thermodynamisches Beispiel : Unter dem ersten Systeme verstehen wir
die Molekiile eines Gases, unter dem zweiten einen das Gas begrenzenden
beweglichen Stempel, BQ ist die dem Gase zugefiihrte Warme. Mechan-
isches Beispiel : Das erste System ist ein mit einer punktformigen Masse
verbundener Magnetpol der gezwungen ist, sich in einer Ebene zu bewe-
gen, das zweite System ein kurzer Magnet, um welchen der Magnetpol
Vierte Vorlesung. 309
eine Centralbewegung maclit. Nun erfahrt der Magnet eine kleine
Drehung wodurch sich das Wirkungsgesetz der Centralbewegung andert
und ausserdem der Magnetpol einen kleinen Stoss. Das Gesagte soil
gewissermassen ein Schema sein, in welchem die verschiedenen dem
Principe der kleinsten Wirkung verwandten Principe zusammengestellt
sind. Es zeigt sich, dass die Analogien mit dem zweiten Hauptsatze
weder einfach mit dem Principe der kleinsten Wirkung, noch audi mit
dem Hamilton'schen identisch sind, aber sowohl zum einen, wie auch zum
andern in sehr naher Beziehung stehen.
Ich habe zu Anfang betont, dass die Entwicklung der Wissenschaft
nicht immer in stetiger Verfolgung der alten Wege vor sich geht, son-
dern sehr haufig durch plotzliche Einflihrung ganz neuer Methoden und
Ideen gefordert wird. Wo konnte fiir letztere Art der Entwicklung ein
fruchtbarer Boden sein als in Amerika, wo alles neu ist, wo die Geschick-
lichkeit des Geistes, Ungewohnliches zu unternehmen, die grossten unvor-
hergesehenen Schwierigkeiten zu besiegen stete tlbung findet, wahrend wir
in Europa wolgedrillt in den Bahnen der alten wissenschaftlichen Me-
thode uns zwar mit grosserer Leichtigkeit und Sicherheit bewegen, als
die Bewohner der neuen Welt, aber dem Ungewohnten und Neuen gegen-
iiber verbliifft und unbehiilflich sind. Sicher werden daher nicht bloss
die Amerikaner aus ihren rastlosen Bestrebungen die Pflege der reinen
Wissenschaft zu fordern den grossten Nutzen ziehen, sondern auch die
Wissenschaft wird durch die Mitwirkung der Amerikaner stets mehr
und grossartiger gefordert werden. Auch ich fiihle den hohen bildenden
Wert, den es fiir mich hatte meinen engbegrenzten heimatlichen Hori-
zont durch die Bekanntschaft mit der grossartigen Natur und Cultur
Amerikas zu erweitern, wol das fruchtbringendste Experiment, das ich
je angestellt habe. Ich sage Ihnen daher meinen besten Dank fiir die
hohe Ehre, welche Sie mir durch die Berufung zu diesen Vortragen
erwiesen, und wlinsche nur, dass das von mir gebotene nicht ganz hinter
der Grosse dieser Auszeichnung zuriickstehen moge.
COMPARATIVE STUDY OF THE SENSOET AREAS
OF THE HUMAN CORTEX.
By Santiago Ram6n y Cajal.
If order to respond worthily to the gracious invitation with which
Clark University has honored me, I ought to offer you, as was my original
intention, a work of synthesis, a general summary of the present state of
our knowledge of the minute anatomy of the nervous system. Unfortu-
nately, the duties of my professorship, every day more pressing, have
deprived me of the time necessary for the accomplishment of such a task,
and have compelled me to moderate my ambition, and to limit it to
presenting to you a modest analytical contribution to our knowledge
of the microscopical structure of the sensory centres of the human cere-
bral cortex, a subject to which I have devoted the leisure of the past
months.
This subject is so vast and so difficult that, in spite of my efforts and
the time devoted to it, I have been able to clear up only a few points.
Consequently, my contribution will be, to my utmost regret, a very
incomplete one, treating, as it does, only the visual cortex as I have
made it out in man and some of the higher mammals. I shall add,
however, a few observations on the structure of other sensory regions.
This anatomical study of the sensory areas of the cortex, at the
present state of our knowledge, presents points of special interest, since,
as you well know, neurologists who have interested themselves in the
histology of the brain are divided at present into two camps, the unicists
and the pluralists.
The unicist doctrine, proclaimed by Meynert and reaffirmed quite
recently by Golgi and Kolliker, supposes that all regions of the cortex
possess essentially the same structure, functional diversity being due to
diversity of origin of afferent or sensory nerves. This amounts to saying
that cerebral specific energy of nerves is the necessary effect of the partic-
311
312 Santiacjo Ramon y Cajal :
ular organization of each sense as well as of the special character of the
stimuli received by the peripheral sensory surfaces, skin, retina, organ of
Corti, etc.
The pluralist doctrine, upheld recently by Flechsig, without rejecting
the particular influence of connections with different nerves, maintains
that diversities of function result also from the particular structure of
each cortical area.
It is this latter opinion, as we shall presently see, that presents a
closer agreement with the observed facts. In fact, my researches tend to
prove that the topographical specialization of the brain depends not only
on the quality of the stimuli analyzed and gathered up by the sensory
mechanisms, but also on the structural adaptations which the cor-
responding cerebral areas undergo; since it is very natural to suppose,
even if one were to form an a priori judgment, that the cortical areas con-
nected with the spacial senses sight and touch, which form exact images
of the exterior world with fixed relations of space and intensity, have by
accommodation to the stimuli received an organization different from
that existing in cortical areas attached to the chemical senses of taste or
smell, and from that which is appropriate to the chronological sense
hearing, which gives only relations of succession, free from every spacial
quality.
We may add that if there exist in the human cerebral cortex, as
Flechsig supposes, besides the sensori-motor centres, other regions, asso-
ciation centres, characterized by absence of direct sensory or motor con-
nections, it seems very natural also to associate to these important
regions of the brain, with which are connected the highest activities of
psychic life, a special organization corresponding to their supremacy in
the hierarchy of functions.
But we must not carry to an extreme the structural plurality of the
brain. In fact, our researches show that while there are very remarkable
differences of organization in certain cortical areas, these points of differ-
ence do not go so far as to make impossible the reduction of the cortical
structure to a general plan. In reality, every convolution consists of two
structural factors: one, which we may call a factor of a general order,
since it is found over the whole cortex, is represented by the molecular
layer and that of the small and large pyramids; the other, which we may
call the special factor, particularly characteristic of the sensory areas, is
represented by fibre plexuses formed by afferent nerve fibres and by the
Visual Cortex. 313
presence at the level of the so-called granular layer of certain cell types
of peculiar form.
But, before proceeding to outline the general conclusions of an ana-
tomico-physiological order, that result from all our researches taken
together, permit me to present very briefly the facts of observation.
Visual Cortex.
The minute anatomy of the visual cortex (region of the ealcarine
fissure, sulcus cornu lobulus lingualis) has been already explored by sev-
eral investigators, among whom we may make particular mention of Mey-
nert, Vicq d'Azyr, Gennari, Krause, Hammarberg, Schlapp, KoUiker, et al.
But their very incomplete researches have been performed by such insuffi-
cient methods as staining with carmine, the Weigert-Pall method, or that
of Nissl with basic anilines — methods which, as is well known, do not
sufiice at all to demonstrate the total morphology of the elements and the
organization of the most delicate nerve plexuses. They led, however, in
spite of the difficulties which stood in the way of these first analytical
attempts, toward a precise differentiation of the visual cortex from other
regions of the brain. At the outset two characteristic differences
attracted the attention of the first investigators into the structure of the
visual cortex : first, the existence of a very thick stratum of granules, sub-
divided into accessory strata by laminae of molecular appearance; and,
second, the presence in the intermediate layers of the cortex of a white
lamina formed of medullated fibres — which lamina may be seen with the
unaided eye. This lamina, appearing in cross-section as a white line, has
been named, in honor of the writers who first described it, the line of
Gennari or Vicq d'Azyr.
For the sake of brevity, we shall omit a detailed description and dis-
cussion of the various layers admitted by the authorities on this region ;
suffice it to mention in order the eight layers described by Meynert for
the human cortex : First, molecular ; the second, layer of small pyram-
idal cells ; third, layer of nuclei or granules ; fourth, layer of solitary
cells ; fifth, layer of intermediate granules ; sixth, layer similar to the
fourth, containing nuclei and scattered cells ; seventh, deep nuclear
layer ; eighth, layer of fusiform cells. We may also mention the ar-
rangement of layers recently described by Schlapp for the occipital
cortex of the monkey : (1) layer of tangential fibres ; (2) layer of exter-
314
Santiago Ranwit y Cajal :
nal polymorphic cells ; (3) layer of pyram-
idal cells ; (4) layer of granules ; (5) layer
of small solitary cells ; (6) second layer of
granules ; (7) layer poor in cells ; (8) layer
of internal polymorphic cells.
The investigations which I have made on
the human cortex as well as on that of the
dog and cat, by both the Nissl and Golgi
methods, have led me to distinguish the fol-
lowing layers : —
1. Plexiform layer (called molecular
layer by authors generally and cell-poor
layer by Meynert).
2. Layer of small pyramids.
3. Layer of medium-sized pyramids.
4. Layer of large stellate cells.
5. Layer of small stellate cells (called
layer of granules by the authors).
6. Second plexiform layer, or layer of
small pyramidal cells with arched axon.
7. Layer of giant pyramidal cells (soli-
tary cells of Meynert).
8. Layer of medium sized pyramidal cells
with arched ascending axon.
9. Layer of fusiform and triangular cells
(fusiform cell layer of Meynert).
You see that we have modified current
nomenclature by introducing terms which
call to mind cellular morphology. For we
believe that such trite expressions as "mo-
lecular layer," "granular layer," must be
Fig. 1. — Vertical section of the visual cortex of man,
calcarine sulcus, stained by Nissl's method — semischematic.
1. Plexiform layer. 2. Layer of small pyramids. 3. Layer
of medium-sized pyramids. 4. Layer of large stellate cells.
5. Layer of small stellate cells. 6. Second plexiform layer,
or layer of small pyramids with arched axon. 7. Layer of
giant pyramids. 8. Layer of medium-sized pyramidal cells
with ascending axon. 9. Layer of fusiform and triangular
cells.
Visual Cortex. 315
banished once for all from scientific language, and they must be replaced
by terms which point out dominant morphological characters in the
nerve structures of each layer or some interesting peculiarity relative to
the course and connections of the axis cylinder processes. The number of
layers could be easily increased or diminished, because they are not sepa-
rated by well-marked boundaries, particularly in Nissl's preparations.
Thus the number of layers which I adopt is somewhat arbitrary. By
distinguishing, however, nine layers, I have followed a criterion of indi-
vidualization which seems to me the most convenient and suitable for my
exposition of the cortex as a mechanism composed of elements at a cer-
tain level which differ in special morphological features from those of
neighboring levels. Besides, the number, extent, and size of cells in these
layers vary a little in the different median occipital convolutions, as does
also the degree of definite nidification, according as we study the convex
or concave aspect of the gyri. Our description relates generally to the
cortex of the margin of the calcarine fissure, the region where structural
differentiation of the visual cortex is most pronounced.
Plexiform Layer.
The plexiform or molecular layer is one of the oldest cerebral forma-
tions in the phylogenetic series. It presents characters similar to those
of the human cortex in all vertebrates except the fishes. This has been
fully demonstrated by the researches of comparative histology under-
taken by Oyarzun (batrachia), by myself (batrachia, reptilia, and mam-
malia), by my brother (batrachia, reptilia), by Eddinger (batrachia,
reptilia, aves), by CI. Sala (aves). In the visual cortex of man, the
structure of this layer coincides perfectly with that which my own re-
searches, as well as those of G. Retzius, have revealed in the motor
region. The only modification which may be noted, visible even by
Nissl's method, is its notable thinness in the margins of the calcarine
fissure (except in the sulci, and here it appears somewhat thinned).
This diminution in thickness, noted by authors generally, depends
probably on the small number of medium-sized and giant pyramidal cells
in the underlying layers, because it is well known that each pyramidal
cell is represented in the plexiform layer by a spray of dendrites. A
similar opinion has been expressed by Bevan Lewis in order to explain
irregularities in thickness of this layer in different regions of the cortex
316 Santiago Ramon y Cajal :
of the rabbit and guinea-pig. The structure of the plexiform layer is
very complex. From my own researches, confirmed largely by those of
Retzius, Schafer, Kolliker, and Bevan Lewis, it follows that it consists
of an interweaving of the following elements: (a) the radial branches
of the small, medium-sized, and giant pyramidal cells, with which we
must include in addition those of the so-called polymorphic cells ; (6)
layer of terminal ramifications of the ascending axons of Martinotti ;
(c) layer formed by the arborizations of the nerve fibres, terminal or
collateral, which come from the white matter ; (d) layer of special or
horizontal cells of the first layer (Cajal's cells, of Retzius) ; (e) layer of
small and medium-sized stellate cells with short axons ; (/) layer of neu-
roglia cells, well described by Martinotti, Retzius, and Andriesen.
a. Terminal Arborizations of the Pyramidal Cells (Fig. 4). — As my
observations have shown in case of the mammalian cortex, and those of
Retzius for the human foetus, the radial trunk of the pyramidal cells
does not end, as Golgi and Martinotti supposed, in a point entwined by
neuroglia elements in connection with the blood-vessels, but in a spray of
varicose dendrites covered with contact granules, spreading out some-
times over a considerable area of the plexiform layer. In my first work
on the cerebral cortex, I thought that the only cells whose terminal
dendrites reached up to the first layer were the medium-sized, small,
and giant pyramidal cells ; but my latest researches have enabled me
to discover that all cells possessing a radial stem, without exception,
including even those of the deeper layers, are represented in the plexi-
form layer by a terminal dendritic arborization. It is without doubt
an important structural law whose physiological import must be very
considerable. We may observe that large trunks which arise from the
giant pyramids divide into a spray with very long and thick branches
having their distribution in the deeper level, while the slender stems
emanating from the medium and small sized pyramids form an arboriza-
tion of numerous slender branches of limited extension and distributed
particularly through the superficial lamince of the plexiform layer. This
distribution, which is not absolutely constant, leads us to surmise that
the terminal arborizations of each kind of pyramidal cell come into contact
witli special neuritic terminal arborizations in traversing this first layer.
The trunk and end brush intended for the first layer appear not only
in preparations made by the chromate of silver method ; for I have
stained them perfectly with methylene blue (method of Ehrlich-Bethe)
Visual Cortex. 317
in case of young animals, and also in adult gyrenceplialous mammals,
such as the dog and cat. Besides, in good preparations by Ehrlich's
method, particularly when fixation has been made a short time after the
impregnation, one may see very distinctly the contact granules of the
dendrites, processes which I was first to describe and whose existence
has been confirmed by many investigators since. With methylene blue
they present the same appearance as in Golgi preparations, i.e. they are
slender and short, stand out at a right angle, are sometimes divided, and
end freely in a rounded knob. This proves, accordingly, how groundless
are all the gratuitous objections which have been brought against the
preexistence of these appendages, as well as against their mode of termi-
nation. Among the entirely arbitrary conjectures which have been made
as to the disposition of these appendages we include also W. Hill's opinion,
who considers them the fibres of a reticulum that is incompletely stained
by means of the chromate of silver. We must proclaim emphatically
that at present there is no method of staining cellular processes that
is capable of disproving the agreeing results of the methods of Golgi,
Ehrlich, and Cox. Whoever, having as a foundation the revelations of
any one of these methods, has considered it possible to demonstrate the
existence of such a reticulum has only exposed to view his own lack of
experience in handling these important means of analysis.
b. Special or Horizontal Cells of the Plexiform Layer. — These interest-
ing elements, which I discovered in the cortices of the small mammals (rat,
rabbit, guinea-pig), have been successfully investigated by Retzius in
case of man, as well as by my brother in batrachians and reptiles, and by
Veratti in the rabbit's embryo. They present in the visual cortex, where
I have stained them very often, the same characters as in other regions
of the brain. As I have already described these elements elsewhere, I
shall give here only an outline, to which I may add a few remarks derived
from my recent observations upon man (Fig. 2).
Following the example of Retzius, when we study the horizontal cells
by Golgi's method in a human foetus from the seventh to the ninth
month, or in case of a newborn babe, we notice that they are distributed
throughout the entire thickness of the plexiform layer, but are especially
numerous in close proximity to the pia. Their form is very variable,
sometimes fusiform or triangular, and again stellate, with the angles
extending out into the long processes. But the characteristic feature of
these elements is due to the fact that their processes, which are variable
318
Santiago Ramon y Cajal:
Visual Cortex. 319
in number and very large at their origin, give rise, after a few divisions,
to an extraordinary number of varicose horizontal fibres, extremely long,
from which spring at right angles numberless ascending secondary
branches terminating in rounded knobs near the cerebral surface. Very
often the superior surface of the cell body also gives rise to some of these
ascending branches, which sometimes have a considerable thickness.
In what way do these tangential fibres terminate ? Is it possible to
discern among them certain processes possessing the characters of axons ?
Upon careful examination of the best preparations obtained from
cortices of human embryos, we discover easily that these processes,
when they become very fine, have all the appearances peculiar to axons.
There is no morphological distinction which would enable us to distin-
guish the two classes or species of cellular processes. That which most
strikes one is the enormous length of their horizontal fibres (tangential
fibres of Retzius). One can follow them for two or three tenths of a
millimeter without being able to discover their true termination. How-
ever, in certain cases it is possible to demonstrate that the tangential
fibres, after having given rise to a great number of vertical twigs, become
thinner and finer, and finally subdivide into terminal branchlets, which
spread out under the pia or in the superficial laminae of the first layer.
On comparing these cells of the human brain with their homologues
in the higher mammals (rabbit, cat, etc.), we discover that among the
latter they give rise to a relatively small number of tangential branches,
and that these extend a much shorter distance. This is the reason we
consider the remarkable profusion and the extreme length of the hori-
zontal fibres as one of the most characteristic features of the human
cortex.
Retzius did not succeed in staining the horizontal cells in man except
in the foetal period. Accordingly, it was impossible to know what be-
comes of these elements in the adult, and whether, as Retzius is inclined
to think, all the processes that we find in the embryonic period persist.
My recent researches on the cortex of infants fifteen months and even
fifteen and twenty days 61d, in which I have been successful in staining
the horizontal cells, suffice to furnish a few data which, if they do not
solve the problem once for all, at any rate place the question in a some-
what more favorable light.
When we examine the plexiform layer of a babe fifteen days old,
we find considerable changes in the horizontal cells. First of all, we
320 Santiago Ramon y Cajal:
notice that they have become smaller, and that the tangential processes
have diminished in diameter while they have become notably lengthened.
But the peculiarity which most strikes the attention is the almost total
disappearance of the ascending collateral branches. This atrophy begins
in a progressive thinning of the processes and in the reabsorption of their
terminal varicosities ; then the whole branch disappears, so that the o;ily
structures left are the horizontal fibres, whose ensemble forms throughout
the thickness of the plexiform layer a system of parallel fibres of enor-
mous length. There are places, however, where the ascending branches
persist, but very much changed as to their direction, having become
oblique instead of vertical, becoming branched several times, and termi-
nating in the plexiform layer without reaching so far up toward the
pia as before. In a word, most of the vertical branches seem to me to
represent an embryonic arrangement corresponding to the interstices, for
the most part vertical, between the epithelial cells of the cerebral cortex
of the foetus, which proves once more, as I have demonstrated in other
nerve centres, that during the period of evolution the neuron is the locus
of a double series of functions: on the one side a vegetative building up
of the dendrites ; on the other, reabsorptions and transformations of the
cells which persist.
Have the horizontal cells with which we are now concerned a true
functional process ? In case this is so, what is the part played by these
elements in the vast system of nervous relations established in the plexi-
form layer ?
In preparations of the human brain stained with chromate of silver, it
must be confessed, it is not easy to solve this important question, since
the purely morphological criterion, which is sufficient to distinguish the
axon in other neurons, cannot be applied to horizontal cells, all the pro-
cesses of which, on becoming finer, have the form of true axons. Thus,
in spite of Veratti's affirmation, we believe that this method will shed no
light upon the subject, even when applied to embryos. In order to ap-
proximate to any solution of the problem, we must use a method capable
of staining nerve prolongations in a manner to differentiate them from
dendrites. It was only after using Ehrlich's methylene-blue method upon
the motor and visual cortex of the cat that I became convinced that the
horizontal cells have in reality a very long axon, which is provided with a
medullary sheath. The other processes, which we have called horizontal
fibres, represent true dendrites, as is shown by two peculiarities: the great
Visual Cortex. 321
facility with which they take methylene blue, and their pronounced vari-
cosity after fixation with ammonium molybdate. We must repeat that
this varicose alteration, which is a striking modification in the form of
cellular prolongations, presents itself only in dendrites. The neurites
maintain perfectly, with methylene blue, their normal contours, unless
exposure to the air, necessary to obtain the selective staining, has been
too long.
As to the axon, it may be sufficiently well demonstrated in horizontal
sections of the plexiform layer in the form of a pale blue fibre, except the
initial portion and the nodes, which present a dark blue staining. This
is a property of all parts of a fibre not surrounded with a medullary
sheath. At the point of certain constrictions we may succeed in dis-
covering a few collaterals springing out at right angles, provided also
with myeline sheaths. Finally, one is sometimes so fortunate as to dis-
cover in an axon of this kind true bifurcations situated at a great dis-
tance from the cell of origin, but always in the plane of the plexiform
layer. Unfortunately, the methylene blue does not stain the terminal
nerve arborizations. This has prevented me from learning in just what
way these axons terminate and with what axons they are dynamically
associated. It is possible that certain heavy horizontal fibres come into
contact with the horizontal cells, since they never bend downward
toward the underlying layers, as do the medium-sized and finest medul-
lated fibres. They belong probably to the terminal arborizations of
Martinotti's ascending axons and, perhaps, also to the collaterals and
terminals coming in from the white matter.
e. Cells with a Short Axon (Fig. 3, G-,JE,F}. — A few years ago, while
studying the cerebral cortex of the small mammals, I discovered, besides
the gigantic horizontal cells, other elements which I called polygonal cells.
These are characterized by their stellate form and by their short axon,
which ramifies and ends within the limits of the plexiform layer. These
cells, whose existence neither Schafer nor Lewis seem to have been able to
confirm, — no doubt on account of the insufficiency of their attempts to
obtain an impregnation of them, — are much more abundant than might
have been supposed from my first observations. However, I must acknowl-
edge that, they are not at all easily impregnated with chromate of silver
and that, in order to find a sufficient number for study, we must make a
great many attempts at staining them. On the other hand, Ehrlich's
method stains them very readily in the dog and rabbit. In these animals
322
Santiago Ramon y Cajal :
— and I think that it holds true also in man — the plexif orm layer of the
cerebrum is as richly supplied with elements with a short axon as the
molecular layer of the cerebellar cortex. They occur in all levels of the
layer and differ remarkably in size and shape. The majority of them
are stellate and are comparable in size to other cells with short axons
Fig. 3. — Cells and neuritic terminal arborizations in the 1st and 2d layers ; visual cortex of
infant 20 days old. A and B, neuritic plexus, extremely fine and dense, situated in the layer of
small pyramids; C, an analogous arborization, but not so dense; D, a small cell whose ascending
axon forms a similar arborization; i', spider-shaped stellate cell of the 1st layer; F, G, cells with
short axon branching loosely in the plexiform layer ; a, axon.
that occur in the deeper layers of the cortex. Others are smaller,
resembling in their minuteness the granules of the cerebellum. But
whether large or small, the morphological characters of these elements
are very similar. Their dendrites are divergent, extremely branched,
and distributed exclusively to the plexiform layer. Their neurites are
Visual Cortex. 323
usually very short, subdivide in a most complicated manner in the neigh-
borhood of the cell, but never cross the deep boundary of the first layer.
From the point of view of the direction and length of their neurites
all these elements may be classified into three varieties : (1) Stellar cells
with horizontal neurite which becomes resolved after a varying distance,
generally very long, into a terminal arborization which has the appear-
ance of being connected with the terminal branches of the remote pyra-
mids. (2) Cells of generally smaller size whose neurite branches either
laterally or vertically from the cell body, but always at a moderate dis-
tance (Fig. 3, (t, jP). (3) Very small cells (which I discovered recently
in the human cerebral cortex) provided with numerous fine, divergent,
and slightly branched dendrites, whose neurite, extremely slender, breaks
up near its origin into a dense arborization, exceedingly fine and compli-
cated. We shall designate these elements dwarf or spider-shaped cells.
They may be found, as we shall see, in all the layers of the cortex
(Fig 3, ^).
To sum up : bearing in mind the form of cell bodies and formation
and connection of axons, all the stellate cells of the plexiform layer,
including the horizontal or special cells, seem to me similar to the stellate
cells of the molecular layer of the cerebellum and to those which occur
in the layers of the same name in the cornu ammonis and fascia dentata.
Their function is probably to establish connections between terminal
arborizations as yet imperfectly made out, possibly those formed by the
ascending axons of Martinotti, or the association fibres coming up from
the white matter with the terminal branches of the pyramidal cells.
The function of the great horizontal cells would seem to be to establish
connections between elements, that is to say between terminal neuritic
arborizations and radial dendrites, separated by very considerable dis-
tances ; while the medium-sized and small elements, with their short
axons, would perform the same associative function at short or moderate
distances.
d. Martinotti' s Ascending Fibres. — There is no lack of these in the
visual cortex, although it has seemed to me that they are not so numerous
as in other regions of the brain. Their terminal ramifications, well known
from the researches of Martinotti as well as my own, occupy really the
whole plexiform layer, where they extend over wide areas, distributing
themselves preferably into its deeper levels and coming in contact with
cells with short axons and, possibly, also with the large horizontal cells.
324 Santiago Ramon y Cajal:
Granting that the cells of origin for these fibres lie in layers of the cortex
that contain sensory fibres, we might suppose that Martinotti's ascending
axons represent intermediate links placed vertically between these sen-
sory fibres and cells with short axon in the plexiform layer. And as
these are connected, perhaps, with the dendrites of the pyramidal cells,
the result would be that the sensory stimuli, entering the cortex in this
indirect way, would be compelled to traverse two intercalated nerve
cells before reaching the pyramids.
e. Neuroglia Cells. — These conform in the visual cortex to the well-
known types of other cerebral regions. We find accordingly : (1) Cells
with long radii, the marginal cells well described by Martinotti, which
lie just under the pia. They emit long, smooth, descending processes
radiating across the plexiform layer, ending at different levels both of
this and of the layer of small pyramids ; (2) Cells with short radii.
These elements, long since described by Golgi, and described in de-
tail by Retzius, by myself, Andriesen, Kolliker, and others, are charac-
terized by their form, very often stellate or fusiform, by their location in
all levels of the plexiform layer, and by the great number of their pro-
cesses, short, spongy, branching, and bristling with innumerable contact
granules, which penetrate into the spaces lying between the neuro-proto-
plasmic plexus and are well spread over the interstices of the elements
which must not come into contact. It is in virtue of this intricate rela-
tion between these appendages and the cell bodies and dendrites, as well
as for other reasons which we have not time to dilate upon here, that we
attribute to the neuroglia elements with short processes an insulating
role. According to my view, they prevent inopportune contacts, while
their processes exercise due regard to all points of cells or fibres where
contacts exist and nerve currents pass.
Layer op Small Pyramids.
This layer is well separated from the 1st, but blends by insensible
gradations with the 3rd, or layer of medium-sized pyramidal cells (Fig.
4, B).
Examined in Nissl preparations this layer presents a great number of
small pyramids, very poor in chromatic granules and separated by a
plexus of fibrils much more dense than in the case of cells of the deeper
layers. We find also, scattered irregularly, stellate or triangular cells
Visual Cortex.
325
larger than the pyramids. These are the giant cells with short axon, as
is shown in good chromate of silver preparations (Fig. 6, 2), C). We
shall now discuss the cells of this layer, beginning with the pyramids.
Pyramids. — The morphology and relations of these cells being well
Fig. 4. — Small and medium-sized cells of the visual cortex of an infant 20 days old (calcarine
sulcus). A, Plexiform layer ; B, layer of small pyramids ; C, layer of medium-sized pyramids; a,
descending axon ; b, recurrent collateral ; c, dendritic trunk of giant pyramid.
known since the researches of Golgi, Retzius, and myself, I shall limit
my remarks to a bare mention of a few peculiarities of their disposition
in the visual cortex.
It \vill be noticed that these cells are generally smaller and more
326 Santiago Ramon y Cajal:
numerous in the visual centres than in other cortical areas. Sometimes
the more superficial cells are arranged in one or two regular files and
separated from those beneath by a fine dense plexus of fibres.
The small pyramids give rise to the following processes : an axial
dendrite, often bifurcated near its origin, which runs to the plexiform
layer and terminates in a spray of fine branches, which often ascend
to the neighborhood of the pia; basilar divergent dendrites, rather
long and repeatedly branched ; and, finally, a fine descending axon,
which, in most favorable specimens, can be followed down to the neigh-
borhood of the white matter. From the initial portion of its course spring
three, four, or a larger number of collateral processes, which traverse,
with many subdivisions, in a horizontal or oblique direction, a very con-
siderable extent of the second layer. From the small pyramids lying
close to the plexiform layer, and even from some cells more deeply situ-
ated, the first two collaterals recurve, ascending sometimes, as Schafer
has discovered, up to their termination in the first layer. However, this
termination in the first layer is much less frequent than might be
inferred from this authority's descriptions and drawings. In our prepa-
rations of the visual and motor cortex of a child a few days old and of a
cat twenty-five days old, the great majority of the recurrent collaterals do
not cross the boundary of the second layer. Here, in conjunction with
many neurites belonging to cells with short axons, they assist in forming
a very dense plexus, which contains in its meshes the primary dendrites
of the small pyramids. Generally, — and this may be considered as an
answer to the authorities who strive to convert the recurrent course of
the collaterals into an argument for the doctrine of the cellulipetal con-
duction of these fibres (v. Lenhossek, Schafer), — I may affirm that the
vast majority of the initial neuritic collaterals — and I. consider such all
those that arise within the gray matter — always come into contact with
some of the dendrites belonging to homologous nerve cells situated at dif-
ferent levels of the same cortical formation. When the cells to which
they correspond lie in the same or a deeper plane, the collaterals intended
for them take a horizontal, descending, or oblique course ; but if the cells
of the same category are situated in a more superficial plane than the
point of origin of the collateral, they must describe a recurrent arc in
order to reach their destination.
Visual Cortex. 327
Layer of Medium-sized Pyramids.
Being a continuation by insensible gradations of the small pyramidal
layer, it contains cells of precisely similar form, differing from the cells
of the second layer only in their somewhat greater size, their longer
radial dendrite, and, ordinarily, by a larger number of neuritic collaterals
(Fig. 4, (7). In the deeper level of this layer may be observed — very
seldom, however — large pyramidal cells, but not so large as those situ-
ated in the seventh layer.
Cells with Short Axon of the Second and Third Layers. — These
elements, almost as numerous as the pyramidal cells themselves, may be
seen scattered irregularly throughout the entire thickness of the two
layers. They are generally more numerous near the limits of these
layers, that is to say, in the superficial portion of the second and in the
deeper level of the third layer.
Although in form and size these elements are very variable, and
although there are transitional forms which make it often difficult to dis-
tinguish between them and to subdivide them into well-pronounced types,
still, by considering the size of the cell body and the character of the
axon, they may be divided into the following five classes : (a) cells with
short ascending axon ; (5) cells with short descending axon ; (e) cells
with horizontal or oblique axon ; (d) dwarf or spider-shaped elements ;
(e) fusiform or bipanicled cells, whose axon breaks up into a fibrillar
arborization.
a. Cells with Ascending Axon (Fig. 5, a, B). — As may be seen in
Fig. 5, these cells belong to two principal varieties : (a) Gigantic cells,
with long dendrites (Fig. 5, J., (7). These are quite numerous in the
visual cortex, where they occupy preferably the deep portion of the third
layer. Their form is stellate, sometimes fusiform or triangular. From
their angles arise several varicose, thick, and very long dendrites, often
disposed as two brushes, the one ascending, the other descending. The
axon takes its origin either from the cell body or from a dendrite.
Sometimes it describes an arc, whose concavity is toward the surface, on
its way outward to become resolved into an arborization of very few
branches. The characteristic feature of this arborization is the enormous
length and the horizontal or oblique direction of its terminal twigs.
These traverse a very considerable portion of the second and third
layers, where they make contact with numberless pyramidal cells. It
Fig. 5. —Large stellate cells having short ascending axons, 2d. and 3d layers, visual
cortex, infant 15 days old. A, elements of the 3d layer with axons divided into long horizontal
branches; B, small cell with arched axon from the layer of small pyramids: C, large cell with
arched axon; D, large cell from the boundary of the 1st layer; F, cell with arched ascending
axon branching in a most complicated manner; a, a, a, axons.
Visual Cortex. 329
may be added that these gigantic cells may be recognized even in Nissl
preparations by their stellate form and considerable size. They corre-
spond, probably, to the globular cells of Bevan Lewis and other writers.
(5) Medium-sized type : This is a fusiform or stellate cell, whose size
does not exceed that of the small or medium-sized pyramids. It is
characterized above all by its axon, which is slender and ascending, and
which terminates in a complicated arborization with many varicose
branches and with relatively small spread at varying levels of the second
and third layers. As to the dendrites, they appear varicose and diverge
in all directions, but usually do not extend to the first layer (Fig. 5, F^
and Fig. 3, i)).
h. Cells with Descending Axons. — These are stellate, triangular, or fusi-
form, of medium size, and provided with many ascending and descending
dendrites. They occur chiefly, as has been pointed out by Schafer for
other regions of the cortex, along the superficial boundary of the layer of
small pyramids (Fig. 5, B, and 6, (7). Their axons descend through
the second and sometimes through the third layer, giving off to them
a few collaterals, and terminate in a diffuse arborization throughout the
different levels of these layers. Very frequently this axon, after descend-
ing a certain distance, emitting a few collaterals to the layer of small or
medium-sized pyramids, traces an arc with concavity toward the surface
and ascends to terminate in an arborization, very complicated and with
exceedingly varicose branches, in the layer of small pyramids close to the
plexiform layer (Fig. 5, B). As seen in Fig. 6, which reproduces certain
cells of short axons from the visual cortex of the cat, these elements with
descending axons are very numerous in other gyrencephalous mammals.
We also find a variety of cell, recognized in man, pyriform, uni'-polar,
whose single descending process gives rise to a bouquet of varicose
dendrites and an axon (Fig. 6, a, 5). The collaterals and terminal
arborizations of these axons form in the cat a dense plexus throughout the
superficial plane of the layer of small pyramids.
The great number of cells with short axons which occur in the most
superficial lamina of the layer of small pyramids has induced certain writ-
ers, such as Schafer and Schlapp, to consider this transitional region as a
special layer, which they call the layer of superficial polymorphic cells.
We cannot subscribe to this innovation because, in spite of the great
number of these cells, this transitional lamina contains also a large num-
ber of small pyramids, that is to say, cells which, in addition to their
130
Santiago Ramon y Cajal:
morphological varieties, have the same connections as ordinary pyramidal
cells. Of course, if for the subdivision of the cortex into layers we take
Fig. 6. — Cells with short axons from the layer of small pyramids, visual cortex of cat aged
28 days, a, b, small pyriform cells with short descending axons: c, cell with arched axon; e, f,
cells with descending axons distributed to the medium-sized pyramids of 3d layer.
as our basis of classification the form of cell bodies, independently of other
characters, we might be entitled to differentiate between the first and
second layer consisting chiefly of stellate cells ; because in this region, as
Visual Coi'tex. 331
is well known, the small pyramids have a stellate or triangular form.
But, in assigning to an element a place in his classification, one must not
decide from the form alone, which in case of superficially placed pyramids
is a function of their position. In fact, we find that the form of these
cells varies according to their proximity to the plexiform layer. The
true characteristic of a pyramidal cell consists in the presence of a long
axon extending down to the white matter and of a spray of dendrites
(supported or not by an intermediate trunk) spreading up into the plexi-
form layer. Now, in the light of such a criterion, it is easy to see that
sufficient reason does not exist for making out of the most superficial
pyramids a distinct category of cells to be used as a basis for the creation
of a new cortical layer.
c. Cells with Horizontal or Oblique Axon (Fig. 7). — These elements,
which are .angular or fusiform, with their long axes more or less hori-
zontal, possess few, but rather long, dendrites. Their axon arises gen-
erally from the lateral aspect of the cell body or from a thick polar
dendrite, takes from the first a horizontal or oblique direction and, after
giving off a few collaterals, terminates, sometimes after extending to a
considerable distance, in an arborization widely spread but with few
branches. In certain cells of this category, it is shorter and subdivides
in the immediate neighborhood of the cell body (Fig. 7, E^ C).
d. Divarf or Spider-shaped Cells. — Brought to our attention by CI.
Sala in the corpus striatum of birds, mentioned also by my brother in
the cerebral cortex of batrachians and reptiles, these strange elements are
notably abundant and of very pronounced character in the cerebral cortex
of man and gyrencephalous mammals. They are found irregularly scat-
tered in all layers of the visual area. Their soma is very small, not ex-
ceeding the diameter of the nucleus by more than five or six ix. About
the nucleus is a thin lamina of protoplasm which is drawn out into
a great number of dendrites, delicately varicose, radiating, slightly
branched and short. The appearance of these dendrites is such that one
might mistake the cell, at first sight, for a neuroglia corpuscle with short
processes. But, examining them with a high power, we recognize at
once that their slender dendrites do not possess collateral appendages
(contact granules), so characteristic of processes of neuroglia cells. Finally,
attentive examination reveals the axon, a delicate fibre, which becomes
resolved immediately into a very dense varicose arborization of incompar-
able fineness. Often this terminal plexus is so extremely fine that it
332
Santiacjo Ramon y Cajal:
appears through an ordinary objective as a yellowish or brownish spot in
the neighborhood of the cell and resembling somewhat a granular precipi-
FiG. 7. — Cells with short horizontal or oblique axons situated in the 2d and 3d layers, visual
cortex of infant a few days old. A, B, cells with axons almost horizontal from 2d layer ; C, D, E,
cells with short axon diffusely branched ; F, H, I, pyriform cells of the 1st layer, whose sig-
nificance is still uncertain ; G, small cell with very short axon diffusely branching within the
1st layer.
tate. In some cases this arborization is coarser and can be seen with a
Zeiss objective D or E. At the level of the superior boundary of the
layer of small pyramids, in the visual cortex of the child and even of
Visual Cortex. 333
other mammals, may often be seen a dense plexus of exceedingly slender
branching fibrils. Their original fibre appears to come from the deeper
levels of the 2d layer (Fig. 3, A, B, (7). These terminal plexuses often
take the impregnation irregularly, which gives the appearance of brownish
or coffee-colored spots scattered and sometimes arranged in a row just
underneath the plexiform layer. At first I was not successful in tracking
satisfactorily the fibres of origin and, therefore, hesitated as to stating
the significance of these interesting arborizations. Very recently, how-
ever, in two or three fortunate specimens I have been able to demonstrate
the connection between this plexus and the fine ascending axons of certain
small cells situated in the deeper level of the 2d or outer level of the 8d
layer. I am, therefore, now inclined to consider this intermediate, or sub-
plexiform, nerve plexus as consisting of terminal arborizations intended
for the small pyramids. The fibres of origin spring from more deeply situ-
ated spider-shaped cells very hard to impregnate. I may add that these
plexuses are not lacking in the cat and dog, although in these animals
the fibrillse are not so numerous nor so extremely fine as in the human
brain. Permit me also to add that they occur in all regions of the cor-
tex, although up to the present we have obtained the best impregnation
of them in the visual area.
e. Small Bipanicled Cells. — In the visual region, as well as in other
areas, of the human cortex we find in profusion certain small cells vertically
elongated. Their axon presents the very singular feature of breaking up
into long slender brushes of terminal fibrillse. At first, I thought that
these singular cells were forms characteristic of the acoustic area, for here
they are remarkably developed and very numerous. Further investiga-
tion, however, has convinced me that they occur in all parts of the
cortex, disposed in greatest numbers along the lower level of the 2d and
3d layers (Fig. 8 and Fig. 11, E, F^.
As stated above, we are discussing the small spindle-shaped cells
with poles radially disposed, which give rise to groups of dendrites,
slender, unprovided with contact granules, very finely varicose, and often
arranged in long ascending and descending brushes. In some cases these
are so fine that on superficial examination they might be mistaken for
delicate neuritic arborizations. But the most striking peculiarity of
these cells concerns the subdivisions and course of their axons. This pro-
cess is very delicate. It ascends or descends a certain distance, then gen-
erally gives off a few collaterals at right angles which soon subdivide into
334
Santiago Ramon y Cajal:
Fig. 8. — Small fusiform, bipanicled cells
from auditory cortex of infant (1st temporal
convolution). A, cell giving origin to a de-
scending axon moderately branched ; B, cell
whose axon breaks up into a number of pen-
cils of very long ascending and descending
fibrils; a, axon. (Examined with Zeiss apo-
cliromatic obj. 1.30.)
ascending or descending fibrillae, and
finally it breaks up into brushes of
very slender filaments which run radi-
ally, extending throughout almost the
entire thickness of the cortex. As a
whole this arborization with its initial
collaterals forms one or several parallel
brushes, the fibrils of which skirt the
trunks of the pyramids and adapt them-
selves to the cell bodies, over which
they appear to creep, like the creeping
fibres of the cerebellum on the branches
and bodies of the Purkinje cells.
In the brain of the human infant
at birth these arborizations have not
attained complete development and
present but few vertical branchlets.
It is not until twenty or thirty days
after birth that we can observe the
long and complicated terminal brushes.
In certain areas, the acoustic, for ex-
ample, each neurite may form as
many as five ascending or descending
brushes. The fibrils of which they
consist are so delicate that in order
to see them well we must use the
highest apochromatic objectives.
If now we consider all the differ-
ent kinds of cells having short axons,
of which we have given a somewhat
fastidious description, from the point
of view of their connections and their
probable functions, we may character-
ize them as special cells of association.
The form of their cell body and the dis-
position of the axon vary according to
the number, form, and position of the
cells to which they must convey nerve
Visual Cortex. 335
stimuli. Thus cells with a horizontal axon must be intended to transmit
impulses to elements, probably pyramidal cells, which occur at the same
level in the cortex. Those whose axon is vertical, ascending or descend-
ing, would naturally transmit impulses to elements of different layers.
Those which are bipanicled would serve to associate dynamically a great
number of pyramids in vertical series. Finally, the small, spider-shaped
cells may have for their function association of groups of pyramids very
close together. Unfortunately for this theory, we do not know from which
nerve fibres all these elements of association receive their initial stimuli.
Accordingly, we must be resigned to remain in ignorance as to the path of
the afferent impulses and, as well, in regard to the special influence which
these elements must exercise. It seems very probable, however, that
their function consists not only in facilitating the spread of incoming
stimuli, but also in adding to it something new, some specific modifica-
tion which cannot now be determined. We shall return to this point in
our general conclusions upon this work. But we may see from the above
how many paths nature has opened up to render association of nerve
impulses possible in every direction and through any distance. That
which proves the importance of these association cells and leads us to
surmise that they play an important psychic role is the fact that they are
extremely numerous in the human brain. They are found in the animal
brain as well, but are not numerous and are usually confined to the
boundary of the 1st layer.
I conclude here my exposition of the prosy topics that I chose as
the theme of this lecture. And nothing remains except to thank you for
the attention and good will which you have shown me in spite of the
extreme dryness of the subject-matter.
LECTURE II.
Layer of the Large Stellate Cells.
My recent researches in the visual cortex of man have led to the unex-
pected discovery of certain large cells of stellate form possessing an axon
which descends to the white matter. Figs. 9 and 10 represent very
clearly the most common forms of these strange elements. They are
differentiated immediately from pyramidal cells by their lack of a radial
trunk. Generally speaking, the cell body is stellate, but there is no lack
of semilunar, triangular, and even mitral forms. Their dendrites are
thick and much branched, and extend in all directions, especially horizon-
tally, without ever leaving the territory of the 4th layer. In man these
processes are sparsely provided with contact granules, while they are very
numerous in the homologous cells of the mammalia (cat and dog).
As to the axon, it is rather large, arises from the inferior surface of the
cell body, descends through the 4th layer, sometimes tracing here accom-
modation curves, and after crossing the 5th, 6th, 7th and 8th layer, passes
into the white matter and is there continued as a medullated nerve fibre.
In passing through the 4th and 5th layers it gives off three, four, or a
larger number of, often, very large collaterals which end in arborizations
extending over a considerable area in these layers. It is not uncommon
to see these collaterals taking a recurrent course to become distributed in
planes above the point of origin ; but in this they never trespass on the
boundaries of the 4th and 5th layers. Finally, and this is a very frequent
disposition in the adult cortex, this axon, after having given off its col-
laterals, becomes notably finer. Taking into consideration its diameter,
sometimes less than that of its first collateral, we might be led to mistake
it for the latter rather than a true continuation of the axon. We shall
return to this peculiarity, which is presented by many cells in the visual
cortex. The stellate cells present a similar character in the adult human
cortex, and I reproduce in Fig. 10 their principal types impregnated (long
method of Golgi) in the case of a man thirty years old. The only
336
Visual Cortex.
337
difference that we remark between these cells in the adult and infant
brain is the greater development of the dendrites, which extend long
distances in horizontal planes in the adult. The volume of the soma also
J
Fig. 9. — Layers 4 and 5, with portion of 6 ; stellate cells of the visual cortex, infant 20 days
old, calcarine sulcus. ^, layer of large stellate cells; a, semilunar corpuscle ; 6, fusiform horizontal
cell ; c, cell with radial trunk ; e, cell with arched axon ; B, layer of small stellate cells ; /, horizon-
tal fusiform cells ; g, triangular cells with heavy arching collaterals ; C, layer of small pyramids
with arched axon ; h, cells of this type.
increases with age, which shows that growth of dendrites does not depend
solely on the lengthening out of the initial or primitive protoplasm of the
cell, but also on an actual augmentation of cell substance.
338
Santiago Ramon y Cajal :
Cells with Short Axon. — As it happens in other cortical layers, the
4th contains a large number of cells with short axon. The following
three types may be distinguished : —
Fig. 10.— Large stellate cells of the adult brain, man 30 years old, neighborhood of calcarine
sulcus. A, B, C, F, stellate cells of the 4th layer ; D, E, K, medium-sized stellate cells of 5th
layer ; G, H, J, cells with short axon. (Golgi's slow method.)
(a) Cells, stellate, fusiform, or triangular, whose axon ascends to be
distributed in the superficial plane of the 4th layer (Fig. 11, A, (7, i>).
(5) Cells of similar form and position, but whose axon distributes
itself to the layer of medium-sized pyramids (Fig. 11, B).
(c) Spider-shaped cells with a notably short axon, as may be seen
in Fig. 13, E,
Fig. 11. — Cells of the visual cortex, infant 15 days old, 4th layer. A, cell sending axon to
superior portion of 4th layer ; B, cell whose axon branches to the 3d and 4th layers : C, another cell
sending branches into the 3d, 4th, and 5th layers ; E, F, very small bipanicled cells from layer of
medium-sized pyramids; a, axon.
340
Santiago Ramon y Cajal:
The cells with ascending axon are remarkable on account of the curi-
ous arched course of the latter. It has in some cases initial collaterals.
The stellate cells as well as other cells with the short axon are also
found in the cortex of the cat and dog, where they form a well-defined
layer of their own, corresponding, considering the character of its elements,
to the 4th, 5th, and 6th in the visual cortex of the child. Fig. 12. Cells
Fig. 12. — Stellate cells from visual cortex of a cat aged 28 days. A, layer of stellate cells
corresponding to the 4th and 5th layers in man ; B, layer of giant pyramids ; a, h, c, stellate cells
having long descending axons ; d, e, medium-sized pyramids among the stellate cells.
with short ascending axon are especially numerous and are characterized
by being fusiform in shape and by the contact granules which cover the
cell body and principal dendrites. Besides the existence of cells in the
cerebral cortex whose axons ascend, but do not make their way into
the first layer as do those from Martinotti's elements, is the fact that I
long since discovered while working upon the motor cortex of the small
Visual Cortex. 341
mammals; this is, as my latest observations show, that these elements are
very numerous, and that each cortical layer, or better, that each layer of
a plexiform aspect, contains a special kind of this element. In addition,
as we shall see in a moment, these cells form a constant factor in all the
cortical layers in which nerve fibres incoming from the white matter
make their terminal arborizations.
Fifth Layer, or Layer of Small Stellate Cells.
This layer, which corresponds to the greater part of the stripe of
Vicq d'Azyr, when examined in Nissl preparations appears to contain an
enormous number of small rounded elements which might be mistaken
for scattered nuclei not surrounded by protoplasm. But in these same
preparations we may still detect, beside these corpuscles, a few others,
scattered here and there, of stellate or triangular form and medium or
large size, very similar to the great stellate cells of the 4th layer.
Golgi's method reveals to us the great complexity of the 5th layer, and
by this means we have succeeded in differentiating as many as five kinds
of elements. The following are the most common types : —
(a) Stellate Cells of Medium Size. — These are exactly similar to the
stellate cells of the 4th layer. They are not numerous, and lie irregu-
larly scattered in all levels of the 5th layer. Their dendrites diverge,
but run for the most part horizontally, and do not pass beyond the layer
of their cells of origin. Their axons descend and, after emitting a few
collaterals to the 5th layer, make their way to the white matter. In
some cases their collaterals are given off lower down, in the 6th layer,
and then their course is recurrent, because they must make their terminal
arborizations between homonymous cells (Fig. 9, g^f).
(6) Cells with Ascending Axon. — These are fusiform or triangular, dis-
posed with long axis vertical. Their axon is similar to that of cells of
this type in the 4th layer. That is to say, after ascending a certain dis-
tance it forms a terminal arborization of arching branches distributed
among the elements of the overlying layer. From its initial portion
spring a few collaterals which are distributed to the 5th layer (Fig. 13,
A, B, C).
((?) Ovoid or Stellate Corpuscles (jproperly designated., Grranules'). —
These rarely exceed in diameter more than ten or twelve fi. They are
the most numerous element of the 5th layer. Their soma is ovoid,
342
Santiago Ramon y Cajal :
spheroidal, and even polygonal in form and gives rise to three, four, or
more fine, smooth dendrites, which terminate, after a short, wavy course,
within the limits of the 5th layer. Their axons are very delicate and
Fig. 13. — Cells in the 5th layer with ascending axon, visual cortex of infant aged 15 days.
A, B, cells whose axons subdivide in the layer of large stellate cells ; C, cells whose axons give rise
to branches destined for the layer of medium-sized pyramids; D, cell with arched axon, the initial
portion of which gives rise to branches for the 4th, 5th, and even 6th layers ; E, very small cells,
arachniform, with delicate ascending axons; a, axon.
Visual Cortex.
343
take a great variety of directions, — ascending, descending, or horizontal,
and finally end in an extended arborization of few branchlets dis-
tributed exclusively to the very midst of the 5th layer (Fig. 14).
(^d) Dwarf or Spider-shaped Corpuscles. — Of these there is no lack in
Fig. 14. — Small cells in the layer of small stellate cells, possessing short diffuse axons (infant
20 days), a, cells with delicate ascending axon; b, c, cells with descending axon; d, larger cell
whose axon forms its terminal arborization in the 4th layer ; a, axon.
344
Santiago Ramon y Cajal :
this layer, whose nerve plexus they help to bewilder. Their very tiny,
often ascending, axon resolves itself very soon into an extremely dense,
Fig. 15. — Cells with short axons of the layer of stellate cells from the visual cortex of a cat
aged 28 days, a, large cell whose descending axon subdivides in the deeper level of the 4th layer
(4th and 5th of man) ; 6, arachniform cell whose axon forms a fine and very dense plexus ; d, fusi-
form cell whose axon is resolved into vertical branches.
fine arborization close to the cell. In the dense masses of these arbo-
rizations we notice spaces, which probably correspond to groups of
granules.
Visual Cortex.
345
The cells with short axons are very abundant in the visual cortex of
the cat, as may be observed by examining Figs. 15 and 16. Among them
the more abundant types are : a, fusiform cells whose ascending axon is
distributed to the superior levels of the layer in question (4th and 5th in
man) (Fig. 16, i)); b, large stellate cells with descending axon forming
their terminal arborizations in the deeper levels of this layer (Fig. 15, a) ;
Fig. 16. — Elements from the layer of stellate cells of the visual cortex of a cat aged about one
month. A, B, C, small pyramids with axons arched and ascending; D, large fusiform cells with
ascending axons ; E, arachniform cells with short axon ; a, axon.
c, stellate-arachniform cells whose axon forms a most complicated arboriza-
tion (Figs. 15, 5, and 16, J57); d, bipanicled cells larger than corresponding
cells in the human brain (Fig. 15, c?).
Nerve Plexus of the -^th and bth layers of the Cortex. One of the chief
characteristics of these layers consists in the very dense plexus of medul?
lated fibres extending among their nerve cells. This is formed by two
kinds of fibres : (1) Exogenous fibres, that is to say those coming from the
white matter, probably continuations of the cerebro-optic tract. (2) En-
346 Santiago Ramon y Cajal:
dogenous fibres, formed by the terminal arborizations of the axons which
come from cells of the 4th and 5th or the underlying layers.
Exogenous Fibres. — I have already stated that Gennari's or Vicq
d'Azyr's stripe corresponds chiefly to the 5th layer, but also includes part
of the 4th. However, the true composition of this stripe cannot be seen
in Weigert-Pal preparations, because the hematoxylin stains only the large
or medium-sized fibres which possess a myeline sheath. Now these fibres,
as we shall presently see, represent but a very small portion of the com-
ponents of Gennari's stripes. Very fortunately Golgi's method, applied
to the brain of an infant at birth or but a few days old, affords us a very
clear view of the medullated and unmedullated fibres which make up this
plexus. This method accordingly furnishes us a means of analyzing its
origin and manner of termination. Permit me to state at the outset that
the principal contingent of exogenous fibres is represented by a consid°
erable number of fibres from the white matter, which I shall henceforth
call, in virtue of their physiological significance, optic fibres.
The optic fibres are easily distinguished from the axons of the pyra-
mids by their direction, which is oblique (in some cases they are tortuous
or even stair-shaped), by their large calibre, often exceeding that of axons
of the giant pyramids ; finally by the fact that, instead of going to a cell
as its axon, they repeatedly divide dichotomously, each branch resolving
itself into a perfectly free terminal arborization spreading almost horizon-
tally through the extent of the 4th and 5th layers. Fig. 17 reproduces the
appearance of the optic plexus in a preparation in which it was impreg-
nated almost alone. I call your attention to the fact that these optic fibres
send off no collaterals, or very few, in passing through the deeper layers
(9th, 8th, 7th, 6th), but immediately on reaching the 5th layer their final
ramification begins. This occui-s in many ways. Some fibres divide at
different levels of the 5th layer into two equal or unequal branches which
run horizontally to great distances, becoming resolved into a great number
of collaterals which ramify throughout the entire thickness of the layer.
Other fibres may be seen which, after giving off a few long collaterals
during their ascent through the 5th layer, reach up to the extreme limit
of the 5th layer and here become horizontal. There is no lack of fibres
which ascend directly up to the limit of the layer of medium-sized pyra-
mids and there describe arcs, and even very long wavy courses, and end
by descending, dividing as they descend, through the 4th and 5th layers.
Finally, from the arching portion of some of these latter fibres fine collat-
Visual Cortex.
347
erals may be seen to spring on their way to the layer of medium-sized
pyramids, where they disappear after a few divisions. To sum up, the
optic fibres terminate al-
most exclusively within
the 4th and 5th layers.
In only two instances
have I discovered col-
laterals of optic fibres
which appeared to form
their terminal arboriza-
tions within the 1st
layer.
This plexus of optic
fibres is one of the rich-
est and densest to be
found in the gray mat-
ter of the brain. If it
is completely impreg-
nated, which frequently
occurs in an infant brain
fifteen or twenty days
old, it appears as a be-
wildering meshwork of
wavy fibres, besprinkled
with vacant spaces cor-
responding to the cell
bodies of these layers
(Fig. 18, ^).
I may add that the
appearance of this
plexus diffres a little
in the two layers (Fig.
18)
Fig. 17. — Heavy fibres coming from the white substance
and subdividing in Gennari's stripe ; visual cortex of infant aged
three days. A, white substance; B, layer of small stellar cells;
C, arched fibres of 4th layer ; D, border of layer of medium-
sized pyramids ; a, trunks of the incoming fibres ; b, collaterals
In the 4th layer for the deeper layers; c, ascending collaterals destined for the
^, , , more superficial layers.
its fibres are larger and
often disposed in arches or horizontal bars, its arborizations are loose
and separated by ample spaces in conformity to the size of the great
stellate cells; while in the 5th layer it consists of fine varicose fibrils
arranged in an extremely dense latticework with small spaces, corre-
348 Santiayo Ramon y Cajal :
sponding to the small size of the medium-sized stellate cells (Fig.
18, By
111 the preceding brief description I have called the large exogenous
fibres optic fibres. But what reasons have we to suppose that these
fibres actually come in from the primary optic centres'? We must
acknowledge, at the outset, that the proof of their optical origin is not
perfect ; but there is no lack of facts which favor such a view. Some of
these facts are the following : —
(a) In the minute brains, as, for example, that of a newborn mouse,
we can follow these fibres in some cases to the radiation of Gratiolet.
(h) The fibres which are on their way to Gennari's plexus are very
large, larger than the axons of the giant pyramids or those of cells of
intercortical association.
(c) In the motor cortex we have found that large fibres distributed in
a similar way actually come in from the corona radiata.
(cZ) In the visual cortex of a man who became blind I have discov-
ered, by using Nissl's method, a perceptible atrophy of the stellate cells
of the 4th and 5th layers. A similar case has been recently reported by
Cramer ; and this fact would seem to point to an intimate union between
these elements and the act of visual perception, a union whose material
bond is probably represented by the exogenous fibres of Gennari's plexus.
(e) Granted that the visual cortex must receive a great number of
fibres from the radiation of Gratiolet, it is natural to refer to this source
the fibres which form Gennari's plexus ; since this is the distinctive
plexus of this region of the brain.
From the probable fact that the plexus of Gennari's stripe is the
terminus of the optic fibres, we may draw the important conclusion that
the cells of the 4th and 5th layers represent histologically the principal
substratum for visual sensation ; because up to this point in the cortex
sensory impulses heap up on the centripetal side, and here begin to
become centrifugal.
Another conclusion not less interesting follows from it : for an ensem-
ble of anatomico-physiological facts seem to show that the region of the
calcarine fissure is not the locus of visual memories, but only that of sen-
sations of luminosity, and that the residues of the latter must go (in
order to become transformed into latent images) to other nerve centres.
We are naturally led to consider the long axon of the 4th and 5th layers
as the principal, if not the only, path joining these two kinds of centres.
Visual Cortex.
349
Fia. 18. — Nerve plexus of the 4th and 5th layers from the visual cortex of an infant aged 20
days. A, B, C, respectively, layers 4th, 5th, and 6th ; a, trunks of optic fibres ; b, axons of cells of
the 6th layer ; c, ascending axons of cells in the 8th layer ; d, bundle of axons descending from the
medium-sized pyramids ; e, transverse arches of the optic fibres giving rise to ascending collaterals.
350 Santiago Ramon y Cajal :
These fibres would function, accordingly, in carrying the copy, or the
sensory residue, received in Gennari's plexus, to appropriate association
areas of the brain. Their psychic role is thus a very important one, and
we should suppose that their interruption would produce psychic blind-
ness as certainly as the destruction of the occipital lobe itself.
The plexus of Gennari is well developed in other mammals, but the
terminal arborizations are never as complicated as in man (Fig. 19).
Further than this I have not been able to demonstrate any definite differ-
ences in arrangement at various levels of the layer of stellate cells. How-
ever, it has seemed to me that the terminal branches, which are very
varicose, tend to be especially dense in the superficial planes of this layer.
Endogenous Fibres. — In addition to the large nerve fibres entering
from the white matter, Gennari's plexus contains either terminal or
collateral ramifications of fibres which arise in the cells proper of the
visual cortex. Such are : —
(1) The very numerous branches from the small cells with short axon
of the 5th layer.
(2) The terminal neuritic arborizations of cells with ascending axon
lying in the 6th, 7th, and 8th layers.
(3) Arborizations of collateral branches supplied to the 4th and 5th
layers by the long descending axons of the stellate cells.
(4) Terminal arborizations from the fusiform or triangular cells of the
4th and 5th layers which have ascending axons, etc.
The plexus formed by all the above fibrils is usually finer than that
of the optical fibres. In order to make out to the best advantage its
extreme complication throughout its whole extent, we must study it in
the cortex of an infant from fifteen to twenty-five days old, a period at
which the terminal arborizations of the visual cells are completely devel-
oped. It has seemed to me that the endogenous arborizations are more
numerous in the 4th than in the 5th layer. We may notice also that
they show a tendency to form true nests surroundmg the stellate cells of
these two median layers.
Sixth Layer.
Plexif orm and poor in cells in Nissl preparations, it contains a large
number of small pyramidal or ovoid elements with long axis vertical and
provided, as may be seen in good Golgi specimens, with a radial trunk
extending up to the first layer. They have also a few short basilar
Visual Cortex.
351
YiG 19. — Optic fibres from visual cortex of cat 5 days old. A, bifurcation of fibres a short
distance from the white matter ; B, nerve plexus in layer of stellate cells (4th and 5th layers
in man).
352 Santiago Ramon y Cajal:
dendrites, descending or oblique and little branched. But the most dis-
tinctive character of these small elements consists in the course of their
axons. These descend a short distance, then curve upward and ascend
through the 6th, 5th, and 4th layers, to which they give a few collaterals,
and end in a manner which I have not been able to discover. In some
cases these axons have branched close to their origin and, instead of one,
describe two arcs continued by ascending fibres. Other axons, more-
over, make even a greater number of loops. From the convex aspect of
these curves, as well as from the ascending portion of the axons, within
the 6th layer spring numerous collaterals which branch throughout the
entire thickness of the layer. Some descend still further and subdivide
in the plexus of the 7th layer, that is to say, at the level of the giant
pyramids (Fig. 20, B).
Besides these small cells, which are certainly the most abundant, we
find two other cellular types : (a) Cells of stellate form and medium
size. They possess radiating dendrites which do not usually pass beyond
the 6th layer. Their axons ascend and form an arborization throughout
the extent of the 6th, 5th, and 4th layers. (5) Ordinary pyramidal cells,
very scarce, of medium or large size. They have precisely the same
characters as the pyramids of the 7th layer.
Seventh Layer or Layer of Giant Pyramids.
Solitary Cells of Meynert. — This layer contains one or two irregular
and discontinuous files of giant pyramids, which appear, here and there,
lost as it were in a dense and extended plexus. To this plexus the layer
owes its finely granular appearance, which may be seen even in prepara-
tions stained by Nissl's method (Fig. 20, (7, and Fig. 22, B^.
The cells in question, like other pyramidal cells, possess a very large
radial trunk which ends in a flattened spray of horizontal branches in the
lower levels of the plexiform layer. The cells are also provided with
a few many-branched basilar dendrites which distribute themselves
throughout the layer and, finally, with a great number of horizontal
dendrites forming a plexus which would seem to provide connections
between these cells through long distances. This is such a characteristic
feature that by its presence alone we are able to distinguish the visual
from all other cortical areas. The axon of the giant pyramids is very
large, extends almost vertically through the 8th and 9th layers, and is
Visual Cortex.
353
continued as a fibre of the white matter. Collaterals spring from its
initial portion which ramify in the 7th and even the superficial levels of
the 8th layer.
In addition to the giant pyramids, which in some cases are not at all
Fig. 20. — Cells of the 6th and 7th layers from the human visual cortex, infant 15 days old.
A, 5th layer ; B, 6th layer ; C, 7th layer ; a, giant pyramid; b, medium-sized pyramid with descend-
ing axon; c, small pyramid with arched ascending axon; d, pyramid whose axon presents two
arches ; e, pyramid whose axon gives rise to several arched fibres ; h,f, g, stellate cells with ascend-
ing axons ramified in the 5th and 6th layers ; i, J, K, pyramids whose axons arch and subdivide
in the 7th and 8th layers.
numerous, the 7th layer contains : (a) a number of medium-sized pyra-
mids possessing the same characters ; (6) several small elements exactly
similar to those of the 6th layer, the cells with the complicated forked and
arched axons distributed in the manner above described (Fig. 20, K, i, J) ;
(). Their axons
spring from the inferior surface, descend almost in a straight line, and,
after giving oif a few large collaterals, very frequently arched and re-
current, are lost in the white matter. These interesting cells, exactly
similar to the stellate cells of the visual cortex, are also found in the
motor cortex of gyrencephalous mammals, although, to judge from my
own preparations, only in small numbers. Their presence would seem
to indicate distinctively sensory regions of the brain.
Elements with Short Axons. — These are also very numerous in the
infant brain, representing, perhaps, the chief morphological factor of the
4th layer. Several varieties have been distinguished, of which the most
common are the following : —
(a) Stellate or Fusiform Cells of Medium Size. Their dendrites
368
Santiago Ramon y Cajal:
diverge in all directions, but chiefly above and below, and end in the
midst of the 4th layer. Their axon springs from the superior surface,
ascends for a variable distance, and at varying levels of the layer of stel-
Fio. 26. — Cells with long axons from 4th layer of motor cortex of infant aged one month.
A, B, C, small pyramidal cells; D, large stellate cell; E, medium-sized pyramid; a, axon; 6, c,
large descending collaterals.
late cells forms an arborization of horizontal or oblique branches of con-
siderable length and distributed exclusively to the 4th layer. Very
often the axon branches in the form of a T before proceeding to its ter-
minal arborization, and from its initial part arise collaterals whose course
Sensor ir Motor Cortex.
369
and terminations resemble those of the terminal branches. These cells,
we may add, correspond in all points to the cells with ascending axons
described for the 4th and 5th layers of the visual cortex (Fig. 27, A^ (7, D).
(6) Fusiform, Triangular, or Stellate Cells. These are somewhat
Fig. 27. — Cells with short axons from 4th layer of motor cortex of infant. A,B,C, cells, stel-
late or fusiform, with ascending axon divided into long horizontal branches ; E, arachniform cell ;
F, cell with axon distributed to layer of medium-sized pyramids.
larger than the preceding. Their axon ascends to the plexiform layer,
in which it subdivides and terminates. In its ascent it supplies a few
collaterals to the 4th and 3d layers. These elements, as we see, corre-
spond to the so-called cells of Martinotti. In a few cells of this class
the axon possibly does not reach the first layer, becoming lost in the
layers below (Fig. 27, A).
2 B
370 Santiago Ramon y Cajal:
(e) Small Stellate or Spider-shaped Cells. These possess fine and
richly subdivided dendrites and also a neurite, which forms a very rich
arborization close to the cell (Fig. 27, -^).
(c^) Bipanicled Cells. These have the characteristics already de-
scribed in our study of the visual cortex.
(g) Finally, in the cat and dog I have found a few stellate cells
with very numerous dendrites, whose descending neurite forms a very
dense and complicated arborization, for the most part in the 4th layer,
but in some cases extending down to the deep layer of giant pyramids.
Possibly these cells are homologous to the spider-shaped cells in man,
which they resemble in the extraordinary richness of the plexus formed
by the axon. It would then be necessary to suppose, however, that in
the cat and dog these cells are much larger than in man.
In order to complete my description, permit me to add that there is
no lack of ordinary pyramidal cells, in some cases large, scattered irregu-
larly in the 4th layer (Fig. 26, ^). In mammals like the cat and dog,
and to a much greater degree in the rabbit, the profusion of pyramidal
cells obscures our picture of the granular layer.
Sensory Nerve Plexus of the 4th Layer. — One of the most significant
facts which I have discovered in the motor cortex is a plexus of very
large fibres whose numerous subdivisions occupy the 4th layer and
extend even into the 2d and 3d. They probably enter the cortex from
the corona radiata. As early as in my first work I called attention to
these fibres as being different in diameter, direction, and origin from
axons of pyramidal cells, but at that time I had not succeeded in deter-
mining the region to which they are peculiar or the precise place of their
termination in the cortex. My recent researches upon the brain of man
and also small mammals enable me to add a few details to my description
of some years ago (Fig. 28).
First of all, I have been able to determine exactly their origin and
position in the brain. These are both easy to observe in the brain of a
rabbit at birth and still better in that of a mouse a few days old. In the
mouse it may be seen especially well that certain large fibres (called by
KoUiker, who has confirmed their existence, fibres of Cajal) proceed from
the corpus striatum, enter the white matter, and often extend horizon-
tally in it for great distances. In their course they throw off long col-
laterals, which penetrate into the overlying gray matter. All these
collaterals, as well as finally the original axon itself, ascend through the
Fig. 28. — Plexus of heavy sensory fibres from motor cortex of cat 25 days old. A, plexiform
layer; B, layer of small and medium-sized pyramids; C'and D, layers of granules and superficial
layer of giant pyramids ; E, deep layer of giant pyramids ; F, layer of polymorphic cells ; a, fibre
from white matter ; h, ascending collateral ; c, varicose terminal arborization ; d, fibre directed to
the plexiform layer, VFhich appears to be distinct from the large fibres.
372 Santiago Ramon y Cajal:
polymorphic layer, dividing once or twice, then, passing obliquely through
intervening layers, form an arborization of heavy fibres within the layers
of small, medium-sized, and large pyramidal cells. However, in the rat
and rabbit these branches are most numerous in a relatively superficial
plane, which corresponds probably with the granular layer of the human
brain, — a layer that is not differentiated in the small mammals. We
also find a relatively small number of branches that ascend to the
plexiform layer. As to the cortical distribution of this plexus, we
may also place on record a fact of interest. It never covers the whole
cortex. It begins to appear some distance from the median fissure and
disappears below long before reaching the olfactory area or limbic lobe.
I have never observed it in the cortex of this sulcus, nor in the anterior
portion of the frontal lobe, nor even in the region of the auditory or
visual centres.
I shall return to this matter in a future investigation, for I think it
merits most thorough study ; because, if it can be confirmed in a positive
manner and by other methods, we shall possess a criterion by which to
distinguish between areas of association and projection in the cortex.
The projection areas will probably be found to be not, as Flechsig thinks,
those possessing fibres that go to the corpus striatum (since Dejerine
and others have discovered these fibres in the so-called association
centres) but those receiving sensory fibres. At the same time, the
association centres will be characterized by the absence of these direct
sensory connections. At any rate, I believe that even in the brain of the
smallest mammal there are areas, of small extent it may be, specialized
to store up the images or residues of the sensory projection centres. It
would be most astounding if the brains of the small mammals possessed
a different architecture from that of man, taking into consideration the
fact that all the senses have the same essential structure in all mammals
and that memory — visual, tactile, muscular, etc. — is just as necessary to
their lives as to our own.
The sensory plexus is highly developed in gyrencephalous mammals
and in man. I have found it well impregnated in the brains of infants
at birth and a few days old. Here it appears made up of large fibres
having an oblique direction and a flexuous or even staircased course.
After dividing several times in the 6th and 5th layers they give rise to a
singularly extended arborization of horizontal fibres distributed chiefly
to the layer of granules or small stellate cells. We thus see in the motor
SensorirMotor Cortex. 373
cortex, as was the case in the visual, that the layer of granules is the
principal focus of sensory impressions. From this terminus they are
propagated by the numberless cells with short ascending axons to the
layers above and especially to the medium-sized and giant pyramids.
However, it must be acknowledged that the sensory plexus is not so
narrow and well defined as tb j optic. For, although its greatest density
occurs in the 4th iaj^er, its vjrminal branches divide in their ascent
to the superficial layer of medium-sized and giant pyramids. The fibres
which extend up to the small pyramids in man are not numerous. It is
for this reason that I cannot agree with Bevan Lewis in ascribing to
them sensory functions. I do not wish to be understood to deny the
sensory function of the small and medium-sized pryamids. . According to
my view, all the cells of the motor cortex are sensory because they all,
possibly, come into contact either directly (cells of the 3d, 4th, and
5th layers) or indirectly, through the intervention of cells with short
axons, with sensory terminal arborizations. But, since some cells send
their axons to the pyramidal tracts, we are able to distinguish them
as sensori-motor cells of the first order. The others, which send their
neurites to other motor areas of the brain, possibly effect contact with
sensori-motor cells of the first order located elsewhere. These cells of
indirect sensori-motor communication we may be warranted in calling
sensori-motor cells of the second order. It goes without saying that this
distinction is purely hypothetical ; for no method enables us to determine
the precise point within the brain where the axons of the pyramidal tracts
of the corpus callosum or of bands of association fibres form their terminal
arborizations.
5. Layer of the Giant and Medium-sized Pyramids. — In the adult
human brain stained by Nissl's method, a section of the motor cortex
reveals, below the granular layer, a layer of plexif orm or granular aspect
filled very thickly, but in no particular order, with a few giant and a
great number of medium-sized pyramids (Fig. 29).
Usually the giant pyramids are located near the 4th layer, forming
there a few irregular ranks. Impregnated by Golgi's method, they
appear similar to the same cells in other regions of the cortex, but differ
in a few particulars. The body is generally conical, very much elon-
gated, giving rise at the apex to a large trunk, often dividing near the
cell, which terminates in the 1st layer in the usual manner. A group
of long complicated dendrites diverges from its base, and from the sides
374
Switlayo Ramon y Cajal :
spring several very long horizontal processes which subdivide into ter-
minal brushes, and these, intertwining with similar structures from
neighboring cells of the same level, form a dense and very characteristic
Fig. 29. — Deep layer of giant pyramidal cells from motor cortex of infant aged 20 days.
A, B, pyramidal cells ; D, C, elements with short axons.
protoplasmic plexus. It is the same arrangement we already know so
well in the visual cortex, except that, instead of one plexus, there are
many. The axon is large and, after giving off very long collaterals to
the 5th and 6th layers, it passes on to become a medullated fibre of the
white matter.
The medium-sized pyramids are very numerous, much scattered, and
Sensor ir Motor Cortex. 375
occur in greatest profusion in the lower levels of the layer. They do
not differ in character from the giant pyramids, except as to the lateral
somatic dendrites, which are few and not characteristic.
Besides the pyramidal cells the 5th layer contains a few other kinds
of elements. From the point of view of their morphology the following
are the more striking types.
(a) Cells which form Terminal Nests. — These cells, very similar to
those which give rise to the basket fibres of the cerebellum, are most
numerous in the 5th layer between or below the giant pyramids. I have
found them also in the layer of granules or small stellate cells.
Their volume is small, similar to that of a small pyramid, and in form
they appear stellate or triangular with very long and much-branched
varicose dendrites. The neurite, however, presents the most distinctive
feature. It ascends, forking close to its origin, and breaks up into a
ramification of very many branches, ascending, oblique, or horizontal.
After a few subdivisions, all these branches make their way to the giant
and medium-sized pyramids to form very complicated varicose arboriza-
tions close around their cell bodies and principal processes, after the
manner of the terminal baskets of the cerebellum or the nests found in
Deiter's nucleus. Each nest contains arborizations from several cells, and
each basket cell helps to form a large number of nests (Fig. 30, d).
(6) Cells with a Diffusely Branched Ascending Axon. — This is a
fusiform or stellate cell located at different levels of the 5th layer, to
which it sends its dendrites. The axon ascends to the superior limits of
the layer where it forks, and its terminal branches form a loose horizon-
tal arborization of an enormous extent and connected probably with the
deep giant pyramids (Fig. 29, C, D).
(c) Small Pyramids with Arched Axons. — This cell, which I have
studied particularly in the motor cortex of the cat, is entirely similar to
the element which we found in the 6th and 7th layers of the visual
cortex. The cells possess a fine dendrite which ascends to the first layer,
where it ends in a very modest and delicate arborization. Their axon
descends and, after giving off a few relatively long recurrent collaterals,
appears to fork and end in the midst of the 5th layer. The branches
which spring from the bend of the arch descend in some cases, but I have
not been able to trace them down to the white matter.
(c?) Cells with Long Ascending Axon. — These are fusiform or tri-
angular cells with long polar dendrites which never reach the first layer.
376
Santiago Ramon y Cajal :
Their axon arises from the superior surface of the cell, and, after giving
off a few branches to the 5th and 4th layers, it continues its ascent to the
plexiform layer and there makes its terminal arborization.
6. Layer of Polymorphic Cells. — This layer contains the same elements
as the layer of the same name (9th) in the visual cortex (Fig. 31), that
Fig. 30. — Pericellular terminal arborizations from the deep layer of giant pyramids, motor
cortex (ascending frontal convolution) of infant aged 25 days, a, axons giving rise to oblique
and horizontal branches ; b, c, d, terminal nests.
is to say, fusiform cells with two long polar dendrites, triangular cells, and
true pyramids. Their axons all go to the white matter. Their ascend-
ing trunks, which are never lacking, become very attenuated on account
of the branches given off while passing through the 4th layer and reach
the 1st layer as an exceedingly delicate fibril, which ends in a fine,
slightly extended, notably varicose dendritic spray.
In Fig. 31, I have reproduced the principal types of cells found in the
polymorphic layer. Besides the medium-sized pyramidal and triangular
types having long descending axons (Fig. 31, A, ^), there occur other
SensorirMotor Cortex.
377
forms in great numbers. These are fusiform or triangular cells whose
axons penetrate into the superposed layers, furnishing to them a great
Fig. 31. — Principal types of polymorphic cells from motor cortex of infant aged 20 days. A, B,
cells with long axons extending to white matter ; C, D, E, fusiform cells with ascending axon ; H,
giant stellate cell.
number of branches. Some of these axons seem to end in the deep layer
of giant pyramids, but others appear to pass beyond this. Finally, there
378 Santiago Ramon y Cajal:
is no lack of arachniforra cells (Fig. 31, /), cells with short axon of the
sensory type of Golgi, whose axons form terminal arborizations in the
layer under consideration. I may add that I have found in two cases
giant stellate cells with heavy horizontal axon which gives off collaterals
(Fig. 31, JST). I do not know the ultimate fate of this process and am
unable to say whether these scattering cells form a constant feature of the
motor cortex.
Cortex of Acoustic, Olfactory, and Associational Areas.
Unfortunately, my own researches are not as yet in a very advanced
state in regard to these important cortical centres. So that any in-
formation that I can give must necessarily be fragmentary and of little
value.
The acoustic resembles exactly the motor cortex as to general
arrangement of cells and layers, but differs from it in a few pecu-
liarities : (1) by the fineness of the fibres forming the plexus at the level
of the layer of granules or small stellate cells ; (2) in the profusion of
bipanicled cells with their very delicate and complicated neuritic brushes ;
(3) above all, by the presence of certain special cells scattered irregularly
through the entire thickness of the cortex. The very large axon of these
special cells extends in a horizontal or oblique direction, but I have not
yet been able to determine exactly its manner of termination. These
large cells are fusiform and lie horizontally. From their polar dendrites
spring a number of fine ascending branches, which subdivide repeatedly
but do not extend up as far as the plexiform layer.
The olfactory cortex, that of the limbic lobe, is characterized by the
following peculiarities : (1) the enormous development of the plexiform
layer and the presence in it, in addition to its usual structures, of the
antero-posterior fibres that come from the external root of the olfactory
tract ; (2) the absence of the layers of small pyramids and granules ;
(3) the presence of certain large horizontal cells below the plexiform
layer ; (4) the peculiar form of the medium- and large-sized pyramids
which emit from the deep end of the cell body a brush consisting of
numerous much subdivided dendrites ; (5) above all, the fact that the
sensory plexus, i.e. the fibres which come from the olfactory bulb, makes
its terminal arborization exclusively in the plexiform layer and in the
most superficial portion of that layer, corresponding to that of the small
SensorirMotor Cortex. 379
pyramids. This significant fact, brought to light by the studies of
Calleja, shows us that the sensory fibres do not end in the same level
of the cortex in all regions. Hence, the layer specialized to serve as
substratum for the phenomena of sensation may change its position in
different sensory areas.
Our task is now drawing to its close. My work upon the topo-
graphical structure of the cortex has been fragmentary and leaves
much to be desired. Many things, in fact, are still undiscovered. But,
despite the very incomplete state of my researches and the narrow
limits of the field they cover, I may draw a few anatomico-j)hysiological
conclusions, of which the chief are the following : —
And first, as to the hierarchy of centres in the cortex of the human
brain, comparing it with the mammalian brain, we may call to mind that,
while it does not contain wholly new elements, it presents very distinc-
tive characteristics, to wit : —
1. The enormous development of the horizontal cells of the plexi-
form layer and the considerable length of their so-called tangential
fibres.
2. The great abundance of cells with short axons scattered through-
out the whole cortex, cells which form special varieties by reason of
differences in their forms and the directions of their axons.
3. The presence of cells with short axons, very slender (bipanicled
spider cells), with terminal arborizations whose delicacy is not approached
by anything found in any animal.
4. The considerable development of basilar dendrites of the pyram-
idal cells.
5. The presence among the mid-layers of the cortex of a formation
of so-called granular cells, a kind of focus occupied by enormous num-
bers of pyramids with short axons descending, arched, and ascending.
This granular formation is present in gyrencephalous mammals, but in
them it is very poor in cells with short axons and in small pyramids.
In the smooth-brained animals it is almost wholly lacking.
The human cortex has evolved, accordingly, along three different
lines : by multiplying cells with long axons and, above all, those with
short axons ; by decreasing the volume of cells and the diameter of cer-
tain fibres in order to make possible within the limits of space a deli-
cate and greatly improved organization ; finally, by varying and infinitely
380 Santiago Ramon y Cajal :
complicating the external morphology of the nerve elements, undoubt-
edly with the purpose of multiplying, in correspondence with their
complexity, functional associations of all kinds.
As to differences and analogies in regional structure, the following
propositions may be regarded as established : —
1. The sensory as well as the so-called associational areas are made
up by a combination of two orders of structural factors. The first
order consists of common factors, which show very little modification.
They are represented by the plexiform layers and the layers of pyram-
idal and polymorphic cells. The second order comprises special fac-
tors, structures peculiar to each cortical area. Their chief anatomical
feature resides especially in the granular layer and is related mainly
to the presence of particular centripetal fibres and of special types of
cells with long axons (stellate cells of different Idnds).
2. It seems probable that the common factors perform functions of
a general order concerned, possibly, with ideas of representations of
all kinds of movements related to the special sensations of which the
cortical region is the seat. It seems also probable that the special
anatomical factors of the sensory areas perform the function of elab-
orating specific sensations (sensation of seeing, hearing, etc.) and also
of conveying sensory residues to the so-called association centres, where
they may be transformed into latent images.
3. Each sensory cortical centre receives a special category of nerve
fibres (fibres of central sensory tracts). Their cells of origin, as has been
shown by the researches of v. Monakow, Flechsig, v. Bechterew, and
many others, reside in the particular nuclei of the medulla, corpora quad-
rigemina, and optic thalami. It is precisely the presence of these sen-
sory fibres of the second order that constitutes the prime anatomical
characteristic of the centres of sensation or projection.
4. The absence of these sensory fibres, which come from the corona
radiata, may be used in all mammals to distinguish the so-called associ-
ation centres. These centres, which exist even in the mouse, also have a
nerve fibre plexus distributed among their median layers (layer of gran-
ules in the association areas in man). The fibres, however, which consti-
tute them are very fine and appear to come from sensory centres of the
brain. Possibly the cells about which these sensorio-ideational fibres
terminate represent the substratum or, at any rate, the first link in the
chain of nerve elements whose function is the representation of ideas.
Se7isorir Motor Cortex. 381
5. Since we have seen that each afferent fibre in the sensory cortex
comes into contact with an extraordinary number of nerve cells appar-
ently scattered without any order, we must suspect that these relations
conform to the preconceived design of a well-determined and constant
organization.
As, at present, it seems to be impossible to discover these relations,
we may surmise that each sensory fibre comes into contact, directly or
through other cells, solely with those pyramids whose stimulation is nec-
essary in order to effect, after the manner of the reflex arc, movements
coordinated and intentional. We may also surmise (supposing that the
stellate cells of the tactile and visual cortex form the link between the
sensory and ideational centres) that each sensory afferent fibre, bringing
a unit of sensation (the impression received by a cone of the retina or by
the terminal arborization of any peripheral nerve fibre), enters into rela-
tion exclusively with the group of nerve cells entrusted with the func-
tion of conveying this impression to a particular point in the associational
cortex.
Many other hypotheses are possible, but I must conclude for fear of
tiring your kind and sympathetic attention and exhausting your patience.
I fear that I have already made too free use of hypotheses and have pre-
tended to fill the gaps of possible observations with arbitrary supposi-
tions.
It is a rule of wisdom, and of nice scientific prudence as well, not to
theorize before completing the observation of facts. But who is so
master of himself as to be able to wait calmly in the midst of darkness
until the break of dawn ? Who can tarry prudently until the epoch of
the perfection of truth (unhappily as yet very far off) shall come ? Such
impatience may find its justification in the shortness of human life and
also in the supreme necessity of dominating, as soon as possible, the phe-
nomena of the external and internal worlds. But reality is infinite and
our intelligence finite. Nature and especially the phenomena of life show
us everywhere complications, which we pretend to remove by the false
mirage of our simple formulae, heedless of the fact that the simplicity
is not in nature but in ourselves.
It is this limitation of our faculties that impels us continually to
forge simple hypotheses made to fit, by mutilating it, the infinite uni-
verse into the narrow mould of the human skull, — and this, despite the
warnings of experience, which daily calls to our minds the weakness, the
382 Santiago Ramon y Cajal : Sensor ir Motor Cortex.
childishness, and the extreme mutability of our theories. But this is a
matter of fate, unavoidable because the brain is only a savings-bank
machine for picking and choosing among external realities. It cannot
preserve impressions of the external world except by continually simpli-
fying them, by interrupting their serial and continuous flow, and by
ignoring all those whose intensities are too great or too small.
I cannot conclude this, my third and last lecture, without a word of
tribute to this great people of North America, — the home of freedom and
tolerance, — this daring race whose positive and practical intelligence,
entirely freed from the heavy burdens of tradition and the prejudices of
the schools, which weigh still so heavily on the minds of Europe, seems
to be wonderfully endowed to triumph in the arena of scientific research,
as it has many times triumphed in the great struggles of industrial and
commercial competition.
PSYCHIC PEOCESSES AND MUSCULAR EXERCISE.
By Professor Angelo Mosso.
First, let me give expression to my gratitude to Clark University,
whose invitation made it possible for me to take part in this celebration.
To the American schools of psychology, a subject which in Europe
forms so characteristic a branch of the development of science, we are all
deeply indebted. Psychology is a fertile field, where philosophers and
scientists can unite for common labor, a field, indeed, where they cannot
be separated from each other, for here the idealists and the empiricists
are held together by a common bond, laboring, as they all are, at the
solution of the greatest and the most difficult of all problems — the inves-
tigation of the human mind.
Clark University, moreover, can boast of having given to pedagogy
also a new impulse. Many excellent teachers come hither to perfect
themselves for their profession. I may be permitted, therefore, to make
both fields, psychology and pedagogy, the subject of my lectures, which
will treat of the relations existing between the psychic processes and
muscular exercise.
I.
It had long been known that our brain has at birth a grayer hue, and
only later takes on a whitish color. This whitish color originates from
the fact that the cerebral nerve fibres, after their complete development,
are surrounded by a sheath which has this color.
To Paul Flechsig ^ is due the great credit of having shown that our
cerebral nerve fibres are not complete at birth, and that the white nerve-
paths come from the medulla, extending from the periphery toward the
centre.
In man, the brain develops later than in all the other animals, because
his muscles also develop later. The striped muscles are more incomplete
at birth in man than in any other animal. For this fact, that the human
brain develops so slowly, I am able to discover no other reason than
383
384 Angelo Mosso :
this, that at birth the organs which effect movement, over which the brain
later exercises its authority, are not yet complete.
The muscles of the adult human being are thirty-seven times as heavy
as those of the newborn child, while the brain of the former is only
3.76 times as heavy as that of the latter.
It had been long known also that the brain of man slowly increases in
weight up to the fortieth year. Recently Kaes ^ has shown that, up to
the fortieth year, there are formed in the cerebral convolutions new plex-
uses of nerve fibres, which are lacking in younger brains.
Excitation of the senses and impulses to movement hasten the devel-
opment of the nerves in question. The experiments of Ambronn and
Held^ have shown that, if one eye of a newborn kitten is opened to
the light, the other remaining closed, the optical fibres of the eye which
is stimulated by the light are more quickly surrounded with myelin than
those of the other. Another important fact is that the motor nerve
fibres are complete earlier than the sensory.
These facts we must apply to pedagogy. Only that science can show
how injurious is precocious instruction for the development of the child.
If we wish to hasten the maturity of the brain, we must decide whether
the formation of the myelin can better be hastened by stimulations of the
senses and intellectual work, or better by muscular exercises. The latter
way seems to me the more natural. We must, therefore, to begin with,
consolidate the motor nerve paths which develop first, and after that seek
to develop the portion of the brain concerned with intellectual work.
Modern views show a tendency to confirm what the great philosophers of
Greece already recognized, viz., that children ought to begin to read and
write only with the tenth year. The conviction is again slowly maturing
that our children begin to learn too early, that it is injurious for the
development of the brain to be fettered to the school-desk when only five
or six years old. The conviction is slowly making its way that no more
time should be devoted to intellectual work than to muscular exercise.
The modern education of youth, however, resembles more an artificial
hothouse culture than a natural training of the human plant.
11.
The fact observed by me that in man the phenomena of intellectual
fatigue are identical with those of muscular fatigue, caused me to inquire
whether or not the conscious processes and those of movement are identi-
Psychic Processes. 385
cal processes, which take place in like cells, or, perhaps, alternately in one
and the same cell.
The new phrenology exhibits a tendency to localize the mental func-
tions, but the old idea, which distributed the nervous functions over the
whole cerebral cortex, does not yet acknowledge its defeat, and what I
have to say to-day will show that there exists an intimate connection
between the conscious processes and muscular exercise.
Doubtless, there are regions known in the brain which are traversed
by the will impulse which sets certain muscle groups in motion, but they
are the junctions of roads, they are the tracks upon which the trains run,
not the stations where the trains are formed, and where they receive the
will impulse. In fact, in cases where it was possible to stimulate electri-
cally the motor region of the human cerebral cortex, the subject declared
that he felt, in that part of the body in which the current caused a mus-
cular contraction, sensations which resembled the creeping or running of
ants.
If the so-called motor region of the brain is destroyed, it is found that
a change of sensibility also takes place. These facts sufifice to show that,
up to the present, no absolute local separation of movement and sensibil-
ity is demonstrable. Moreover, all agree that every will impulse is joined
to the idea of the movement to be executed.
If, in a monkey, the roots of the sensory nerves which go to the arm
are severed, the animal no longer moves the hand spontaneously, although
the voluntary nerve paths are uninjured, because the uhi consistam of
sensibility is lacking. Our mechanisms are so complete that the move-
ment-command is never given by the cells without a clear idea of the
place where it is to be carried out.
In every voluntary movement there exists between the periphery and
the centre such an intimate connection that patients who have lost the
muscle sense can contract the muscles of the hand around an object and
keep them contracted, as long as they look at the object. So soon, how-
ever, as they turn their eyes away, the muscles instantaneously relax. For
a movement impulse to express itself, it must be controlled by the sensory
nerves ; for the will and the sensibility are functions inseparably con-
nected with each other.
ni.
Attention, which has been called an internal sense, shows really in the
best way how isolation from the influence of the external world is possi-
2 c
386 Angelo Mosso :
ble in the study of psychic phenomena. Attention is the most intense
activity of the mind, and yet we all know that we are not capable of
absolutely controlling it. The more or less favorable disposition for
intellectual work, which we perceive on certain days and at certain hours,
awakes the suspicion that attention itself is, to a great extent, conditioned
by internal reflex phenomena.
I have already shown in my writings * that, in a state of attention, the
respiration becomes slower and deeper, the blood-vessels in the forearm
and in the foot contract, the blood flows more abundantly to the centre,
the form of the brain and arm pulse changes, and the activity of the heart
is increased.
In the state of attention, moreover, there exist an increased secretion
of sweat, a greater consumption of the organism — the blood is poisoned
by the products of intellectual fatigue.^
Attention produces not only the same chemical effects and the same
fatigue as muscular exertion does, but we feel also, when we are attentive
to anything, the characteristic muscular strain on the occiput, the fore-
head, and other parts of the body.
One of the characteristic phenomena of attention is its periods, which
have been so well studied by Wundt and his pupils, — periods which
exhibit a great resemblance to those observed by Dr. W. P. Lombard^
in the case of continued muscular contraction. Under the direction of
Dr. G. Stanley Hall, Lindley''' has investigated the involuntary move-
ments which we make when we think of anything, muscular contractions
of the face, hands, and feet. These movements are like those which we
make during muscular exertion.
We cannot force the attention to fix itself upon one object contin-
ually, because it quickly becomes exhausted, and renews itself only when
a new object is offered it, when new paths for its activity are opened.
It is not we who direct the attention. We can only indicate to it the
direction which it is to take according to our wishes. After that it is
free and does what it pleases ; it flits about like a butterfly on the path
which we have pointed out for it.
The excitability of artists, the peculiarity of their character, show that
in them the involuntary movements are more easily executed, and that
intelligence and mobility increase together. But the fact that artists see
objects in a particular way, and that the thing seen by artists, like that
seen by litterateurs, is retained by the memory in very characteristic fash-
Psychic Processes. 387
ion, proves that attention works in a different way with them. The
plastic talent of southern peoples, the ease of their movements, their more
lively gestures, the more intense expression of their emotions, disclose to
us the nature of the artists' genius. I believe, however, that there is also
contained in attention an emotional factor.
IV.
Great impressionability and the capacity to fix the attention for a
longer time are, doubtless, two of the chief conditions for artistic genius.
But I believe also that the exercise of the hands exerts an influence upon
the development of the mind.
During the first epoch of the Renaissance, the greatest artists of
Florence were all apprentices in the workshops of the goldsmiths. Luca
della Robbia, Lorenzo Ghiberti, Filippo Brunelleschi, Francia, Domenico
Ghirlandajo, Sandro Botticelli, Andrea del Sarto, — to mention only a few
examples, — performed, during their apprenticeship, the simplest labors
in the workshop of a goldsmith. But the exercise with which they
gained their manual dexterity surely influenced also the development
of their genius.
In the beginning of the sixteenth century this school ended, but from
the pedagogical standpoint it is still worth studying. If I may be per-
mitted to express an opinion, I would say that the manual dexterity
favored by this labor contributed much to the development of the great
masters of genius.
A fact which cannot be doubted is the manysidedness of genius which
some Italians of the Renaissance possessed, and which has never again
appeared with like copiousness.
Giotto was painter, sculptor, and architect. Leonardo da Vinci was a
celebrated musician, a great painter, an engineer, an architect, a man of
letters and of science. Andrea del Verrocchio was goldsmith, sculptor,
engraver, architect, painter, and musician. These facts are to be read in
many histories of art. An incomparable example, however, is Michel-
angelo. For twelve years he studied anatomy on the cadaver, and after-
wards painted the Sixtine Chapel and executed the tombs of the Medici
and the dome of St. Peter's.
In the artist, better than in other human beings, is seen the inti-
mate connection between the psychic processes and muscular exercise.
Power of resistance against fatiguing labors, dexterity, and capacity
388 Angelo Mosso :
for concentration, are the secret of their marvellous life. I am con-
vinced that muscular movements have formed the omnipotence of genius,
just as, vice versd, intellectual exercises effect advantageously the develop-
ment of the muscles. Michelangelo ground his colors himself. Raphael,
while as an engineer in Rome he carried on excavations and painted
the rooms of the Vatican, wrote a treatise on how the smoking of
the chimney in the kitchen of a prince might be prevented. As Vasari
relates, Perino del Vaga made every mechanical object; he fabricated
often trumpeters' pennons, portieres, drapery, flags, embroidery, and carv-
ing, and painted sarcophagi. He was a great painter, and his stucco
works belong to the most valuable of the Renaissance period. Even if
the genius of these mighty men will remain a secret for all time, yet
we can say this much, that their hand was just as dexterous as their mind
was lofty.
These men, who are the greatest representatives of our race, have
carried the dexterity of their hands to the highest degree of perfection.
They were simple workers, who, laboring untiringly with their hands,
lifted the human mind to the highest ideals of beauty.
If the Greeks excelled all other peoples in genius, it was because they
paid more attention than did the others to bodily exercise ; they brought
gymnastics, the study of bodily positions and bodily exercise, to a height
which has never been reached by other peoples since their day.
V.
Our brain possesses probably more substance than we generally use,
so that a not inconsiderable part of it may be looked upon as an organ of
luxury. The fact observed by me, that we breathe in more air than is
necessary, together with the fact observed much earlier, that we eat much
more than we need, allows us to designate as luxury all that is not abso-
lutely necessary.
Our brain has on the average about a milliard of nerve cells. Many
men have more, and others less brain substance, without it being possible
to detect a difference in the intensity of their psychic processes.
Large and heavy brains are often found in men who do not make full
use of them. Such a brain was that of Rustan, which Rudolphi has
described. It weighed 2222 gr., while that of Helmholtz^ weighed
only 1420 gr. The brain of the unknown, commonplace individual,
Rustan, was therefore 802 gr. heavier than that of Helmholtz. The
Psychic Processes. 389
great facility with which, in the case of partial destruction of the brain,
the individual parts can substitute one another has been demonstrated
by Flourens and Goltz.
Not all the brain cells work simultaneously, but they relieve one
another probably with such punctuality that only under certain conditions
do we notice that some groups are fatigued.
That this relief process exists can be argued from the fact that the
nerve cells offer only a very small resistance to fatigue.
The attention itself works in periods of activity and rest. These
periods have been observed in the case of the sense of sight, as well as in
the senses of hearing, taste, and touch. Since, as Bowditch has shown,
the nerves, as such, do not become fatigued, we must ascribe such fluctua-
tions to the centre.
If we close one eye, and with the other look at an equally illuminated
wall or the sky, we notice that the visual field now darkens, now lights
up again. ^ The dark color becomes green, yellowish, or blue, and appears
in regular intervals, 5-12 times a minute. These periods vanish as
soon as the eye in attention is directed towards a certain object.
I do not believe that this phenomenon arises from the movement of the
blood-vessels, for it appears only when we look with one eye. I am of
the opinion that it points to a relief -process in cerebral activity, and to a
period during which a slight fatigue of the brain cells takes place, if the
latter are not incited by the attention to more intense labor. Our atten-
tion turns automatically now to one, now to the other eye.^^
There exists a remarkable agreement between the periods of activity
and rest of the brain cells and of the sympathetic system. If we investi-
gate the movements of the blood-vessels with the plethysmograph,ii and
also the movements of the bladder,^ we notice great undulations, coincid-
ing with some respiratory movements. In the curves also, observed in
man and animals when the blood pressure is investigated, these fluctua-
tions, which were first described by Traube, are seen. I myself have
shown that the respiratory curve exhibits periods of greater and less
activity. These fluctuations are particularly characteristic in mountain
sickness. With each period of rest the excitability of the nervous centres
is decreased.
From all these phenomena it seems to follow that the nerve cells have
only a small power of resistance, and that they show on the average every
ten seconds a tendency to rest.
390 Angelo Mosso :
I have further been able to show, by means of the ergograph, that to
strongly contract the hand suffices to induce in the brain the first symp-
toms of fatigue, and that a few seconds of rest are enough to make the
nerve cells capable of functioning again.
The very short duration of the capacity to resist in the nerve cells
makes it plain that the brain must necessarily possess a great number of
cells. It is the task of pedagogy to show how the brain cells can most
fitly be employed for the welfare of the individual and of society.
It is already well known that the barbarians were able to learn foreign
languages with greater facility than the Greeks and Romans. ^^ When we
say of young peoples that they will some day excel us in literature, as in
art and in science, we, unconsciously perhaps, intimate thereby that their
brain still possesses tracts of virgin soil, which, with later cultivation,
will become fertile.
VI.
The more mobile the extremities of an animal are, the more in-
telligent it is. Among all birds the parrot is the most intelligent, because
it makes more use than do other birds of its legs, beak, and tongue.
The elephant is more intelligent than all other wild animals, because
he makes use not only of his legs, but also of his snout, as organs of
movement.
Another consideration : The most mobile parts of the body are at the
same time the most sensitive, e.g. the tongue, the hand, the snout. This
increased sensitiveness depends neither on a more numerous ramification
of nerves, nor on the more complicated character of the end organs, but
arises from the fact that the brain itself is more irritable, as shown by
the passions of animals, which are more violent the more mobile the
creature is.
Romanes ^* has already said that the higher intelligence of monkeys and
the highest intelligence of man are related to a more perfect instrument
of motion, viz. the hand, in which the ideal of perfection seems to have
been reached.
The cephalopods, which have eight arms, formed of muscle-substance
and provided with suckers, stand, among the molluscs, nearest to the
vertebrates on account of their strength and power of movement. It was
movement, probably, that developed their brain-ganglia, for these are
larger in the cephalopods than in the other molluscs. As they possess a
good memory and a high intelligence, so they also exhibit more intense
Psychic Processes. 391
emotions, as may be seen from the great facility with which the color of
their skin changes.
The mutual relation of intelligence and movement is one of the most
constant factors in nature. The movements always change when the
intelligence changes. We need only consider the gait of the Indians in
order to convince ourselves of the truth of my assertion. Their walk is
characteristic, being heavier and slower than ours. Microcephalic indi-
viduals have an awkward gait, and an inconsiderable dexterity in the
movement of the hands. This change in movement is still more striking
in the case of idiots.
In some parts of Italy and of Switzerland there are many cretins. On
my frequent Alpine excursions, I was often able to recognize by their gait
the degree of intelligence of persons who were near me. I have con-
vinced myself of the fact that the first signs of cretinism can be detected
in the heavy gait, the arched vertebral column, and the manner of moving
the arms in walking.
VII.
Neither anatomy nor physiology has hitherto been able to decide
whether like brain cells have different functions, or whether all cells
perform the same service.
Since neither chemically nor by the use of the strongest microscopes
can we demonstrate differences in the nerve cells of the cerebral cortex,
it is therefore probable that none such exist. Hence, I believe that the
psychic functions cannot be separated from the motor, that rather the
psychic phenomenon and that which imparts the movement impulse both
have their seat in the same cell. How closely connected thought and
movement, consciousness and muscular activity, are, is best seen in the
phenomena of sleep. If, shortly before going to sleep, we hold a book or
some other object in the hand, we notice that the object falls, the muscles
relaxing, the moment consciousness ceases. The significance of the fact
emphasized here is not decreased by the phenomena of movement observed
in somnambulists and individuals who have been hypnotized. It is well
known that one can ride and walk when asleep. By practice one can
learn to play the pianoforte without distinguishing the individual finger-
movements. Some can play an instrument when asleep. But these are
not voluntary, but instinctive and reflex movements.
In a diseased arm, in which the muscles have been atrophied, the
sensitiveness of the fingers is simultaneously improved if one seeks to
392 Angela Mosso :
remove the atrophied condition of the muscles by exercises in contrac-
tion.
When the brain has been fatigued by exclusively intellectual activity,
the sensitiveness of the hand and direct irritability of the muscles are
also decreased. These observations force us to the assumption that the
intelligence, the sensitiveness, and the movement are phenomena which
cannot be separated from each other, that their fusion and their con-
nection belong to the conditions which permit us to comprehend the
nature of the mind.
Imbecile signifies weak in body, but particularly weak in mind. In
Latin, however, in hacillum means "leaning on a staff." The ancients
have thus understood the relations in question better than I am able to
express them in words.
vm.
It is well known that an injury on a certain spot in the left temporal
lobe of the brain carries with it the loss of speech. Forty years ago
Broca first described a case of this kind. At the autopsy of a man who
had lost his speech, whose right arm and leg were paralyzed, and who,
besides, exhibited disturbances of intelligence, there was found a broad
and deep depression of the brain substance, extending from the Sylvian
fissure to that of Rolando. Afterward appeared the celebrated treatises
of Broca, which form an imperishable monument in the history of cerebral
localization. It is the merit of James to have shown that the motor
impulse develops itself before the appearance of language in the convolu-
tions of the left cerebral hemisphere.
In our development gestures and other movements appear first ; then,
later, the sounds of language.
It is not the process of consciousness which makes our hands dex-
terous, but perhaps the movements of the right extremities, which effect
the higher psychic development of the left cerebral hemisphere.
The influence of the hand upon the development of language is evi-
dent from the fact that an aphasic patient is made to write in order that
he may gradually regain the power of speech.
The relation between muscular movements and conscious processes is
so intimate that when the arms and hands of a hypnotized person are
brought into certain positions and certain muscles by external contact
made to contract, certain emotions are induced corresponding to those
muscular contractions. Here, then, intellectual processes are certainly
effected by external muscular activity.
Psychic Processes. 393
There is no doubt that the first human beings were dumb, and that
men for a long time made use of gesture-language for purposes of mutual
understanding before they discovered sound-language. The child, too,
before it is able to speak, expresses itself by gestures. It observes the
looks of its parents and of the persons who speak to it, in order to com-
prehend the meaning of the words heard. Pantomime is the heightened
expression of the involuntary movements which accompany the individual
phases of mental activity. In the hieroglyphs of the Egyptians and in
the representations on Greek vases we recognize the gestures and the
involuntary movements which men made more than three thousand
years ago.
IX.
Leonardo da Vinci, in his treatise on painting, had already attempted
to describe the passions by detailing how to represent a man in a state of
rage and despair. The first men who were able to make themselves
intelligible to each other must also have been the most excitable, and in
them the motor ideas must have been very active. The word and the
language of a people, superhuman gifts, according to the ancients, are
produced by reflex movements, gestures, and interjections. Even now
artists still feel more keenly than others the intimate relation between
muscular movements and psychic functions ; they have the gift of repre-
senting the effects of the emotions upon bodily posture and of idealizing
them.
The great, picturesque mode of representation of the human body,
which was the glory of the Renaissance, had its basis in this physiological
law.
A pleiad of the greatest artists, who perceived the internal power of
the emotions, popularized the study of bodily postures by representing in
sacred and profane creations the feelings that thrilled the soul. They
glorified the naked body, busying themselves with showing through the
study of bodily forms and their movements the perfection and the phi-
losophy of art.
We need here neither to think of the heroic figures of Michelangelo
and their powerful musculature, nor of the pleasing, feeling, and directly
perceived figures of Botticelli, nor yet of the sublimely sensual, passion-
stirred figures of the Venetian school, in order to comprehend how in
works of art the mind is revealed in muscular contractions. It suffices
to recall the sublime figures of Perugino, the teacher of Raphael, which
394 Angela Mosso :
compel us to admiration with their expression of the devotion, the enthu-
siasm, and the ardor of faith. Everything here is kept calm ; in these
figures we find nothing exciting, the expression of the face alone mirror-
ing the mood which the artist himself felt during the production.
In my next lecture I will speak further of the basic conditions of the
emotions. Here, however, I will close.
The nervous system, as you know, consists of an intimate union
between sense-surface and muscles. Golgi and Cajal, the greatest dis-
coverers in the structure of the nervous system, tell us now that there
is no difference to be found in the cells of the central organs, that there
is no evidence of a morphological distinction between motor and sensory
cells in the brain.
The structure of the nervous cells is the same ; the relations alone
are different. Probably there is but one nervous substance, which is
active for all functions. The immense number of the brain cells is
easily explained, since the cells can relieve one another and the nervous
activity go on uninterruptedly from one series of cells to another. The
greatest complication lies in the life of a single brain cell.
In this lecture I have sought to show how intimately related are
mental processes and movements. If we desired to make a pedagogical
application, we might say that physical education and gymnastics serve
not only for the development of the muscles, but for that of the brain
as well.
1. P. Flechsig. Die Leitungsbahnen im Gehim und Rtickenmark des Menschen. Leip-
zig, 1896.
2. Th. Kaes. Ueber die markhaltigen Nervenfasern in der Gehirnrinde des Menschen.
Neurologisches Centralblatt, 1894, p. 410.
3. H. Ambronn und Held. Ueber experimentelle Reifung des Nervenmarks. Arch, f.
Anat. u. Entwicklungsges. Leipzig, 1896, p. 227.
4. A. Mosso. Periodische Athmung und Luxusathmung. Archiv f . Anat. u. Physiol.
1886.
Die Diagnostik des Pulses. Leipzig, 1879.
Ueber den Kreislauf des Blutes im menschlichen Gehim. Leipzig, 1881.
5. Die Ermiidung. Leipzig, 1892.
6. "W. P. Lombard. Alterations in the Strength which occur during Fatiguing Voluntary
Muscular Work. Journal of Physiology, Vol. XIV., 1893, pp. 97-124.
7. Lindley, E. H. A Preliminary Study of Some of the Motor Phenomena of Mental
Effort. Amer. Journ. Psychol., Vol. VII., pp. 491-517.
8. D. Hansemann. Ueber das Gehirn von H. v. Helmholtz. Ztschr. f. Psychol, u.
Physiol, d. Sinnesorgane, 1899, p. 922.
Psychic Processes. 395
9. H. V. Helmholtz. Physiologische Optik., p. 922.
10. Schoii und Mosso. Eine Beobachbuug betreffend den "Wettstreit der Sehf elder. Arch,
f. Ophth., Berlin, 1874, pp. 269-277.
11. A. Mosso. Ueber den Kreislaui des Blutes im menschlichen Gehirn. Leipzig,
1881, p. 101.
12. A. Mosso et Pellacani. Sur les fonctions de la vessie. Arch. ital. de Biol., Tome
L, p. 97.
13. Max Miiller. Vorlesungen liber die Wissenschaft der Sprache. Leipzig, 1866, p. 79.
14. G. J. Romanes. L'^volution mentale chez les animaux. Paris, 1884, p. 4.
THE MECHANISM OF THE EMOTIONS.
By Professor Angelo Mosso.
To-DAY I may be permitted to express my own ideas about the mech-
anism of the emotions.
We are sometimes surprised by a sad or a joyful piece of news. We
all know what happens in a state of fear and distress. Physiological phe-
nomena occur that cannot be described. But when we learn suddenly
that the news which has troubled us is false, that our fear and distress
had no foundation, the internal disturbance does not cease, the physio-
logical phenomena continue in the organism in spite of all efforts of the
will to suppress them.
The investigation of these processes has shown that the seat of the
emotions lies in the sympathetic nervous system.
Before we were born, and for a long time after birth, our life was
entrusted to the activity of the sympathetic system and the reflex move-
ments derived from the spinal cord. We need not be surprised at this,
when we reflect hoAv great an importance nature has attributed to the
vegetative and generative life processes in the formation of the organism.
In decisive moments of life, when the emotions are most violent, it is
just the sympathetic nervous system that comes into action. The intes-
tines and the smooth muscular fibres contract in order to raise the press-
ure of the blood, and to utilize the blood better for the brain and the
muscles.
The first observations concerning this subject were made by me more
than twenty years ago. I was able to see that in sleep a contraction of
the blood-vessels always takes place as soon as the sense organs and the
skin are stimulated, even when the stimulation is so weak that the subject
does not wake up.^ These changes, which result without our knowledge,
form one of the most remarkable arrangements which we can observe
nor,
Emotions. 397
among the perfections of our organization. During the interruption of
consciousness our body does not remain helplessly exposed to the influ-
ences of the external world, or in danger of becoming the prey of its ene-
mies. Even in sleep a portion of the nerve centres watches over the
operations of the external world, and prepares in good time the material
conditions for the awaking of consciousness. If we glance back at the
unconscious processes which we saw take place in sleep under external
influences, we shall see that they are all coordinated in correspondence
with a final object ; they all coincide in favoring the circulation of the
blood in the brain, and thereby making it possible that, in case of danger,
the organ may awake to full activity.
I do not believe myself far from the truth in maintaining that the
totality of the reflex movements to be observed during sleep forms a real
defensive apparatus for the organism.
Other investigators have since demonstrated the same thing. Two
years later, in 1881, Dr. Pellacani and I found that even very weak sensa-
tions caused a contraction of the bladder. ^ These facts had, in general,
been already known, for these contractions have become proverbial in
connection with fear and other emotional conditions ; but no one had
previously observed that this organ reacts with such facility to all sense
impressions that its tonicity changes in consequence of attention and incon-
siderable psychic processes.
IT.
The organs of the abdomen and the pelvic cavity are just as sensitive
to the emotions as the heart. I have studied the movements of the
abdominal organs, the stomach, and the rectum. In the smallest emotions
movements of the intestines and stomach always occur.
In the movements of the bladder, we must distinguish between active
and passive, i.e. between such as are peculiar to the bladder itself, and
such as are transferred to it from the diaphragm and from the walls of
the abdomen.
In order to investigate with exactness these movements of the bladder
itself, I have carried on experiments both on the dog and on woman. I
shall first explain the construction of the apparatus employed, and then
give an account of the experiments performed.
The instrument made use of was my plethysmograph, which has the
advantage of maintaining the pressure constant and of registering the
slightest movements of contraction and relaxation of the bladder.
398
Angela Mosso :
A catheter for female use (Fig. 1) A is in communication witli a
glass tube BO which, with a rectangular curve, sinks to the depth of 1 or
2 cm. below the level ah of the liquid contained in the large receptacle, P.
This descending tube must be put into a perfectly vertical position before
Fia. 1. — Arrangement of the plethysmograph for tracing the movements of the bladder.
every experiment, and fixed firmly in that position by the iron support
DE. The pressure-screws at the foot of the support facilitate this nec-
essary arrangement. A test-tube F^ like those used for chemical reactions,
with very thin walls, and suspended by two silk threads from a pulley 6r,
is held in equilibrium by means of a piece of lead H, which has the
same weight as the cylinder F. To this counterpoise is fixed a pen for
Emotions. 399
tracing on a smoked cylinder, or on the continuous roll of a Ludwig
kymograph.
The cylinder F is suspended in such a manner that it has the vertical
glass tube in perfect correspondence to its axis and so that it can move
up and down without touching it.
In order to avoid the attraction of the cylinder by adhesion to the
tube running down its axis, and the consequent development of resistance,
it is advisable to furnish the lower end of the tube with a little ring
of sealing-wax, or of india-rubber, cut from a tube of corresponding
diameter.
The cylinder F is drawn up until its bottom touches the lower end of
the vertical tube ; the jar P, for the time being, we suppose to be full
of water.
The catheter A and the bladder of the animal or human being into
which it is introduced must be on the same level ah as the liquid in the
large vessel. The true level is easily found by placing the plethys-
mograph and the cylinder on which the tracing is done on a strong iron
table, which may be raised or lowered by means of a screw ; a photog-
rapher's table serves the same purpose.
The tube AIBO and part of the cylinder P being filled with water,
the catheter is introduced into the bladder, and the clip I opened. If
a contraction of the bladder takes place, a quantity of water correspond-
ing to the diminution of the capacity of the bladder will flow into the
cylinder F. The cylinder F, becoming heavier through this afflux of
water, is bound to sink into the liquid of the jar below until it has dis-
placed a volume of liquid corresponding to the increase of water received.
If a dilatation of the bladder takes place, a certain volume of water will
flow into it, and the cylinder becoming lighter will rise to a corresponding
height above its original level.
Had the walls of the cylinder neither volume nor weight, and were the
jar full of water P so wide that the immersion of the cylinder would not
sensibly alter the level of the water contained, it is clear that the cylinder
might rise or sink without any change taking place in the level of the
water, either in the cylinder or in the jar P. But since the walls of a
glass cylinder, however thin they may be, have nevertheless a certain
weight and volume, the immersion of the cylinder in water will cause a
loss of so much of its weight as would correspond to the weight of a
cylinder precisely similar with walls of water. This diminution of weight
400 Angela Mosso :
at the side F oi & system FIT, which is held in equilibrium by means of
the pulley G, must produce a displacement. The counterpoise H, which
has remained constant, will repair the loss in weight of the cylinder F in
raising above the level ab a weight of water in the cylinder which will
equal the loss in weight of the cylinder in its immersion.
A column of water being raised in this manner above the level a6,
there is of necessity an augmentation of pressure within the bladder cor-
responding to the height of the column. In order to remedy this defect,
which as a rule is not more than a column of 2 cm. of water, we fill the
jar P with a liquid which is less dense than water, that is, with alcohol
and water. At every contraction of the bladder a corresponding quan-
tity of water will pass into the cylinder, and the latter will sink into the
diluted alcohol in the jar P. As, however, the density of this liquid is
less than that of water, the cylinder F will not only, in its descent, dis-
place a volume of alcohol equal to that of the water which it contains, but
will tend to sink lower, thus carrying the level of the water it contains
below the level ab of the surrounding alcohol.
Then, again, we have already noticed that the cylinder in plunging
into the liquid loses gradually in weight, in accordance with the well-
known principle of Archimedes, and that the counterpoise, which remains
constant, seeks to repair this loss by raising the inner level of the water
ab above the level of the surrounding alcohol, until the equilibrium is
reestablished.
We have, therefore, in this case two forces acting in opposition : that
is, gravity, which tends to bring the water level below the alcohol level
ab, and the loss in weight undergone by the cylinder F during immersion,
which gives it an upward impetus. If these two forces are equal they
will cancel each other and the cylinder F will be able to rise and fall to
the extent of its entire length, the level ab of the water contained in it
remaining meanwhile unaltered.
In order to obtain the exact degree of density necessary to this end we
make use of an empirical method ; that is, we prepare a mixture of water
and absolute alcohol if the cylinder has thickish walls. The liquid will
have the required degree of density when the cylinder is tilled to the
top with water or empty ; in other words, when the cylinder is immersed
up to its neck in the liquid or has its base merely touched by it, the level
ab of the water contained in it remains constant on the plane ab of the
surrounding liquid.
Emotions. 401
For all these necessary operations of filling, emptying the cylinder,
adding or taking away water from the bladder, a glass tube L graduated
in cubic centimetres is made use of. This tube communicates by means
of another of india-rubber closed by a clip K and of a T-tube with the
horizontal tube BO. In order to empty the cylinder F or take water from
the bladder, an inward breath is drawn at the mouth of the tube iV, the
tube L meanwhile being closed with the stopper M, which has a glass
tube running through it ; in order to add water, one need only open the
nipper K.
For the experiments explained in the sequel a graduated and calibrated
cylinder which contained 30 cc. to 18 cm. length was made use of, therefore
every centimetre measured on the ordinates of our tracings corresponds
to a little less than 2 cc.
Care must be taken that the pulley G- be sensitive enough and so well
balanced that it remains in equilibrium in every position. A description
of the apparatus that puts the cylinder S in movement, its velocity being
constant or variable as required, is here unnecessary, as it is a piece of
clockwork with a Foucault regulator which is to be found in all labora-
tories.
When a certain pressure was to be exercised on the bladder in order
to dilate it, it sufficed to raise the table on which the plethysmograph
stood, so that the level ah was above the plane of the bladder, and to add
water with the tube L or to lower the animal or human being.
In order to measure exactly the pressure exercised on the bladder
during our experiments, we made use of a water level consisting of a
simple india-rubber tube with an inner diameter of 5 mm., 1 m. in length,
which had at its end two pointed glass tubes about 20 cm. in length. One
of these tubes being placed near the symphysis pubis, the other was put
against the jar P, and the difference of level between the bladder and the
plane ah was read on a double decimetre measure. This height is the
pressure exercised on the bladder.
Six days after a fistula had been applied to a male dog the bladder
was connected through it with my plethysmograph, and the curve thus
obtained recorded on a rotating cylinder. Simultaneously I had the tho-
racic and the abdominal respiration registered. The movements of the
bladder and of the abdomen are by this means directly fixed upon the
cylinder, while the thoracic respiration is represented reversed upon it,
i.e. a sinking of the curve corresponds in the latter case to expiration, a
2i>
402
Angelo Mosso :
rise to inspiration. Since the three curves were recorded exactly over
each other, the movements could be studied independently and com-
pared (Fig. 2).
The curve for the bladder showed, as was to be expected, also the
respiratory movements. In this curve we see that the bladder begins
to contract before the abdomen rises. This comes from the fact that
the sinking of the diaphragm depresses the intestines, and, with them,
also the bladder. The effect must first appear in the very place where
the resistance is least, i.e. in the open bladder ; then the abdominal walls
Fig. 2. — Relation between the respiratory movement of the thorax (line T) and of the
abdomen (line A) vrith the passive movements of the bladder (line B) .
are forced forward. Some time after the contraction of the diaphragm
the expansion of the chest begins.
But, besides these respiratory movements, there can be perceived in
the bladder curve a slight sinking, and, after it, again a rising of the
whole curve. These are active movements proper to the bladder itself.
They are easily distinguished from the passive movements, since they
occur less quickly.
Another day while we were recording the movements of the bladder,
a servant, to whom the dog was much attached, entered the laboratory.
Immediately the curve showed an active contraction of the bladder, as
may be seen in Fig. 3 at Cr. In dbc we see passive movements of the
Emotions.
403
bladder, which have become weaker because the respiration is
more superficial.
When, shortly before, another person, whom the dog did
not know so well, had entered the room, we had also noticed
another, but stronger, contraction of the bladder. In order
to keep the dog quiet, one of us laid his hand on his head.
(See P in the curve of Fig. 3.) When the hand was taken
away, and the servant laid his upon the dog, there occurred
again an active, but less marked, contraction of the bladder.
As soon as the respiration became more superficial, the passive
movements of the bladder became also less distinct.
After these observations, the dog lay with eyes half-closed,
as if he was about to go to sleep. His tail was touched, and
immediately afterward the curve showed an active contrac-
tion of the bladder, while — what is noteworthy— the rhythm
and depth of the respiratory movements did not change.
After the bladder had again assumed its full volume, and
while the dog was perfectly quiet, his skin was touched, and
the curve record showed at once a stronger, active contraction
of the bladder. In like manner, sensations of pain, which we
produced by pulling the dog's ears, caused strong, active con-
tractions of the bladder.
Such experiments were many times repeated. They were
also carried on with bitches, the bladder being directly con-
nected with the plethysmograph by the introduction of a cathe-
ter, without previous establishment of a fistula. The results
which we obtained were always the same. It was sufficient
to speak kindly to the animals, or to caress them, to make the
curve express the psychic influence upon their active move-
ments.
But I could not rest content with these results obtained
from animals. I needed to corroborate them by experiments
on human beings. Naturally this can be done better with
woman, since with her the bladder can be easily brought into
connection with the plethysmograph by the introduction of a
catheter. My clinical colleagues were kind enough to place
at my disposal some girls from the hospitals, who readily
offered themselves for the purposes of these experiments.
404
Angelo Mosso :
I may be permitted to give an account of these experiments also.
These experiments were carried on, otherwise, as the first. Again I
had the thoracic and abdominal respiration and the move-
ments of the bladder independently recorded. The subject
lay comfortably on a bed. Here, in a state of complete
rest, the whole curve of the bladder was, at times, horizon-
tal, showing, at others, slight active undulations. To
touch the hand of the subject lightly sufficed, however, to
produce at once an active contraction of the bladder.
(See ^in the curve of Fig. 4.)
While the subject was lying quietly on the bed, the
clockwork of the kymograph was wound up (see 0). The
noise resulting was entirely unknown to the subject, but
the impression sufficed to cause itself to be reflected in
the bladder, and to induce a contraction, visible in the
curve. When the subject was addressed (see P), it could
be seen that the bladder contracted immediately, while, if
she herself spoke (see i2), a series of such contractions
took place. All these contractions are movements proper
to the bladder. As was shown by other experiments as
well, they were not transferred to the bladder from the
abdominal walls or from the diaphragm, and were not,
therefore, passive movements F. The lower line T marks
the seconds.
I w^as particularly interested in the movements pro-
duced in the bladder by purely psychic influences. These
are shown, e.g., by the followdng experiment. While the
girl lay quietly on the bed, and respiration was quiet and
normal, — this is always showoi by the curves, — some one
said to her, "Now I'm going to pinch you," but without
doing so. Immediately the bladder contracted, without
the slightest change being noticed in the thoracic and
abdominal respiration. After rest had been again restored,
a jest was spoken to the girl, and again we perceived a
contraction of the bladder on the curve, without seeing any
modification whatever of the two respiratory curves.
Beyond all doubt, then, the contractions of the bladder which we
observed were movements proper to that organ itself.
Emotions.
405
All these phenomena may be considered the most delicate reflex move-
ments which occur in the organism. I was particularly interested to know
what influence a direct activity of the brain would exercise
upon the movements of the bladder, and I carried on experi-
ments to that end. The subject had only a slight education;
she was especially a bad mental arithmetician, very easy
problems in arithmetic causing her difliculties. She needed,
therefore, in such work to exert her brain very much.
While she lay quietly on the bed and her respiration was
quite normal, she was given the following example in arith-
metic : " How many eggs are seven dozen ? " Immediately
the bladder was seen to contract (Fig. 5). After this prob-
lem was solved (see TT), we had her multiply in her head
thirteen by twelve, and then a relaxation of the bladder was
to be seen.
I noticed, also, that merely speaking to the girl, without
her answering, was sufficient to produce a contraction of the
bladder.
in.
The preponderating activity of the sympathetic system
in the emotions is so great that the brain effort is not able
to suppress it. Many men feel a contraction in the abdomen
when they look down from a tower or other high place.
These troublesome sensations, which are connected with the
idea of a possible fall, are simply caused by the contraction
of the bladder and the intestines.
When we investigate, by means of the plethysmograph,
the movements of the intestines during emotional states, we
obtain the same curves as we receive from the movements
of the blood-vessels of the extremities or of the brain, or
from the movements of the bladder. All these facts ena-
ble us to understand the mechanism of the emotions better.
Emotio signifies movement. We understand now that the
constant and fundamental movements taking place in emo-
tions are the movements of the internal organs of vegetative
life.
The investigations carried on in my laboratory by Dr. Kiesow have
convinced me that in certain emotions the blood pressure increases, and
406 Angela Mas so :
the blood-vessels and smooth muscular fibres contract in order to prevent
the blood from being dammed up in the abdominal cavity.
In order to increase the circulation of the blood in the brain and muscles
our bodily machine has to work under a higher blood pressure. This end
could be attained only through the sympathetic system, which sends its
fibres every where to the smooth musculature. During blushing a paling
of the skin can be noticed before the blood-vessels expand, and the blush
proper takes place.
In the study of the emotions the reflex movements of the striped mus-
culature of the face, the extremities, and the trunk are of secondary signifi-
cance to the physiologist. They are simply accompanying phenomena
and, just because they are more complicated, less fundamental.
However useful the first reactions of the nervous system are, yet we
all know that they do not suffice for the defence of the organism in
strong emotions. The nerve substance is so irritable that a small shock
is enough to disturb the equilibrium. I will not enter into detail here,
since I have already shown in my book on " Fear," how unstable is the
equilibrium of the nervous system, and how easily the brain and the
sympathetic system go beyond the proper measure in their activity when
danger threatens, and existence is at stake.
Even a practiced observer is often unable to decide from the gestures
and facial expression of an individual whether he is enraged or in a state
of the greatest joy.
To recall the expressions of two so opposite emotional conditions
sufiices to convince us that the reflex phenomena accompanying them are
not only useless, but even injurious. Indeed, in great pain and great
pleasure we have the same phenomena : trembling of the muscles, secre-
tion of tears, expansion of the pupils, decrease of visual acuity, buzzing
in the ears, oppression of the breathing, palpitation of the heart, inability
to speak, exclamations, convulsive movements of the diaphragm, etc. All
these phenomena are injurious. After the emotion is over we feel nervous
fatigue, have headache, and suffer from insomnia. I am sorry to find my-
self in this matter in disagreement with Darwin, but I cannot concede that
the unconscious processes occurring during the emotions (at least the best
known and most characteristic) have always a physiological purpose.
If we compare the expressions of pleasure and satisfaction in their high-
est degrees with those of pain, it will be seen that there is one and the same
mechanism for both. In my book on " Fear " I have shown that it is the
Emotions. 407
quantity and not the quality of the excitation which disturbs the equilibrium
of our organism. Only the processes which take place in the system of the
great sympathetic are purposive and advantageous for the preservation of
life. And it cannot be otherwise. The animals, whose involuntary move-
ments preserved them from destruction in danger, won in the struggle for
existence over others who possessed in less marked degree this capacity.
Whatever the emotions may be, we always see that in these states the
blood pressure increases, the heart beats become stronger, and the respira-
tion deeper. These advantageous effects are the same in man as in ani-
mals, when they fix the attention, are passionately excited, curious or
jealous, or when they run at play or in pursuit of prey.
But as soon as the emotion becomes more intense, the equilibrium of
the organs ceases. The condition of excitability is increased and becomes
more complicated, contractions of the muscles and changes in the sense
organs take place, from which it results that the capacity for resistance of
the organism is lowered. In strong emotions, as in rage and anger, we
are overpowered by unconscious and discoordinated movements, and a
penetrative and irresistible transformation occurs in us, as if the influ-
ence of education had been extinguished, as if our reason had suffered an
eclipse. We are no longer able to suppress the internal excitement, the
voice refuses its office, and we utter a wild cry. Many persons in such
states gnash their teeth like wild beasts, others act foolishly, like children.
These disturbances occur not only in the reflex movements, but also
in the conscious processes, and more even in the latter than in the former.
Education has taught us that we must seek to master and to calm our-
selves during this internal excitement, for in these states we lack mental
clearness and power of judgment, and consciousness cannot again regain
control until these discoordinated reflex movements have ceased. Even the
ancients knew that strong emotions resembled a suddenly occurring sick-
ness. The legend of ancient Rome idealized a king in order to represent
war. They gave him the name Hostilius, which is derived from hostis.
Tradition further informs us that this king erected a temple to " Pallor and
Fear," for pallor and fear were looked upon as malevolent, destructive
deities who must be appeased in order that the soldiers might be victorious
in battle.^ .
1. A. Mosso. Ueber den Kreislauf des Blutes im menschlichen Gehirne. Leipzig, 1881.
2. A. Mosso e Pellacani. Sulle funzioni dellavescia. Mem. d. R. Accad. dei Lincei, 1881.
3. E. Pais. Storia di Roma. Torino, 1898. Vol. I., Parte I., p. 305.
HYPNOTISM AND CEREBRAL ACTIVITY.
By Professor August Forel.
Gentlemen : — I beg to present to you as few hypotheses as possible,
and to put together as far as feasible merely the facts which must form
the foundation of the present state of the doctrine of hypnotism. We
cannot, of course, get along with no explanatory theory at all. Before
all, we must maintain that everything that is known can be traced alto-
gether to phenomena of brain activity. Everything that one has tried
(and still tries) to bring over from the field of mysticism, or so-called
occultism, has, as far as it could be controlled, turned out to be mistaken
phenomena of brain activity. We may calmly leave the rest to metaphysi-
cal speculators and to the famous breadth of the imaginary knowledge
of the ignorant. Should there be anything in telepathy, for instance,
it would not belong here ; certainly its representatives would have to
furnish better evidence than so far exists.
That much is yet unexplained is perfectly evident — as obvious as
in any other domain of human knowledge. It does not follow, how-
ever, that facts should be ignored, even if their connections present many
obscurities ; nor can we respect here the famous dogmatic line of division
between psychology and cerebral physiology with the traditional awe,
and for this I beg to excuse myself at the outset.
Anatomical Foundation.
However difficult it may be to this day to grasp even the rudiments
of the relation of the brain as an organ to the physiological and psycho-
logical aspect of its function, we should not cease one moment to work on
this problem. Nearer and nearer we must get to it, and, truly, what has
already been reached stands inspection well and need not cause us, in the
least, to despair.
We know to-day that there is only one kind of nervous elements,
409
410 August For el:
that is, the neurone, the cell with its fibre and branched processes. When,
in 1886-87, about the same time as His, I first put forth this view as
a probable hypothesis on the ground of numerous facts, I had no idea
that tliree years later my illustrious colleague, S. Ramon y Cajal, would
establish the matter histologically in such a beautiful and conclusive
manner. The nerve elements do not anastomose, as was formerly be-
lieved, but touch one another by ramifying branches, end-baskets, arbor-
izations, etc. Every nerve fibre (axone), together with its ramifications,
is merely a part of the protoplasm of a certain cell. Further, Schiller
showed in my laboratory that the number of nerve elements in the new-
born (oculomotor nerve of the cat) was approximately as large as in
the adult, and that only the caliber of the medullary fibres differed
enormously. Since it appears certain that, in a lifetime, destroyed ele-
ments of the central nervous system are never replaced by newly formed
ones, we may draw the conclusion that the nerve elements of an old
person are the same as those of his childhood, a point very important
for the theory of memory.
A matter of further importance is the relation of chromatic
reaction of the nerve cell, established by Nissl, to the details of its
finer structure. The fibrils, already recognized by v. Kupffer, Schultze,
Leydig, and others, and the chromatic bodies present, as it were, ele-
ments of a second order, which increase considerably the complication
of nerve structure and open new perspectives. The same holds for the
change of cell structure after exhausting activity, demonstrated first by
Dr. Hodge of this University, and for the grave changes due to the
use of alcoholic beverages established by many investigators — an addi-
tional reason why we should banish those abominable social and indi-
vidual nerve poisons from human diet.
Hand in hand with the progress mentioned, we notice the advances
in the recognition of local structural conditions in the brain of man
and animals, of systems of neurones, etc., especially through v. Gud-
den's method of experimental atrophy; but also by direct anatomical
study. The works of Dejerine and Mme. Dejerine-Klumpke, and of
Kolliker, are encyclopaedic monuments of those researches. I mention
further the doctrine of localization built up by Broca, Hitzig, Ferrier,
Munk, etc., which can only lead slowly to a clear and objective under-
standing of the whole in connection with an accurate knowledge of anat-
omy, of pathology, and of the experimental method of v. Gudden. At
Hypnotism. 411
the same time, we must always guard ourselves against speculations built
on insufficient and unsafe ground, such as the recent doctrines of
Flechsig. While it is possible to establish, to a great extent, the func-
tion of the peripheral nerves and their nuclei of origin by direct
observation and experiment, and while we have also a certain direct
access to the study of the spinal cord, we recognize the function of
the cerebral cortex in two ways : (a) by physiological experiments and
investigations: (5) by so-called introspective or psychological observa-
tion and experiments. But the mutual relations of sensory stimulation
and muscular action to the hemispheres must also be observed both
psychologically and physiologically. If I prick some one, the subse-
quent reflex contraction is observed by me physiologically ; whereas
the character and intensity of the pain which the person claims to feel
can only be measured by him on the psychological side. I see and hear
his answers physiologically only, but make out their sense psycho-
logically only, etc.
If we consider more accurately this continual interaction between
psychological and physiological phenomena in the light of our knowl-
edge of the brain, we are bound to become sure of one thing, viz.
that there is a dark field between the subjectively accessible, psycho-
logical, sentient, and perceptive parts of the hemisphere cortex, and
those representing the physiologically accessible, sensory receiving sta-
tions and the motor, or efferent, mechanisms of motion. In this dark,
intermediate field, powerful accumulations of stimuli of an unconscious
nature must go on, and obscure, instinctive automatic mechanisms,
inherited from our animal ancestors, must work and influence us un-
consciously to a great extent in the shape of impulses and feelings.
We are driven to assume that the great ganglionic nerve centres of
the base of the brain, corpora striata, thalami, pons, tegmentum, cere-
bellum, must play a part utterly obscure, which perhaps might clear
up many points, if we could penetrate more deeply. Unfortunately
this point is still far from accessible, since the fragments furnished by
physiology are hardly fit to be digested.
We should not forget in this whole question what recent investiga-
tions have demonstrated, viz. that the field of expansion of a single
nerve element, a neurone, may be very large. Just think of a Betz-
cell of the central convolutions, the nerve process of which reaches
through the corona radiata, the crus, pons, and pyramid, as far as the
412 August For el:
spinal cord, or of a cell of the anterior horn of the lumlDar cord,
whose process reaches muscles of the foot. Thus, neurones of varied
significance and destination cross and interweave in a thousand ways
in the central and in the peripheral nervous systems, in order to form
the wonderful machinery. One sees, from this alone, how brutal and
defective the physiological experiments in the brain must be, and how
indefinite the physiological concept of a " centre " is.
Physiological Remarks.
There is but little in the old nerve physiology that can be used
to-day, because it rested, to a great extent, on erroneous histological
concepts. We must accept the well-known fundamental facts concern-
ing stimulation, inhibition, reflexes, etc., and also the results of the
pioneers of brain physiology, Flourens, Magendie, Vulpian, Duchenne,
etc. We may conceive that the brain is a powerful accumulator, a kind
of very highly complicated dynamo, in which a still enigmatical physico-
chemical wave-like power prevails, for which I have used the expression
"neurokyme," (the "force neurique " of the French). This force does
not cause any motion of the masses, and consequently belongs to the type
of molecular motion, or vibration, as is shown by its great velocity of
conduction. Its action leaves in the cell visual changes in the form
of material signs of exhaustion. It may be accumulated as energy by
so-called mechanisms of inhibition, and again be discharged in definite
channels by what Exner calls "Bahnung." In this connection, O. Vogt
has justly insisted on the important fact that in excessive stimulation
the effect is often suddenly stopped because a radiation of neighboring
centres of neurones takes place, which is apt to lead away the entire
neurokyme, if those centres are more easily excitable. In this way it is
in a manner possible to understand associative activity. To enter upon
detail would lead too far ; but I beg to say, in a general way, that it is
well known that certain functions become much easier and stronger after
a while through practice ; whereas, in an obscure but very frequent
manner, on the other hand, certain single impulses may leave behind
lasting inhibitions, or stimuli, and perhaps disorders of function which
may take a pathological character, and seriously tantalize the victim.
Such points were used, a few years ago, by Breuer and Freud in
Vienna, for the foundation of their doctrine of arrested emotions, which,
Hypnotism. 413
unfortunately, was developed into a one-sided system, although it started
from correct facts. Thus especially violent affects are apt to leave be-
hind all sorts of nervous disorders (convulsions, paralysis, pains, dyspep-
sia, menstrual disorders). Breuer and Freud tried to lead the patients
in a hypnotic condition to the causative, frequently forgotten, and fre-
quently sexual moment of the trouble, to make them dream over that
moment and to give, once and forever, a counter suggestion, curing the
disorder. In many cases this works ; but by no means always.
Before all, we must acknowledge with Isidore Steiner that the
greatest nerve centre has the dominant position in this interaction of
the neurokymes, owing to its greater mass. It becomes the guide and
director of the whole, and the activity of the other centres is brought
into subjection. Steiner proved this by a clever experiment on a fish,
and showed that in those animals the mid-brain, and not the fore-brain,
is the director and the soul of the animal ; consequently it is not the
morphological homology which decides the absolute anatomical size or
physiological strength, and hence the eminently important fact that the
relative size of the individual part of the central nervous system is of
great importance for the relative independence or dependence. We see
the proof for this fact in the comparative physiology of the animal series.
The spinal cord and ganglia are far more independent in the lizard than
in the rabbit ; much more independent in the latter than in the dog ; and
in the dog, much more independent than in man. In man these organs
have become the subordinated servants of the hemispheres and totally
dependent, although their structure is much more complicated than in
the lizard.
We need not wonder, therefore, if the function of these lower centres
is governed and influenced most powerfully by the dynamics of the fore-
brain just named, even when, as in the sympathetic, only loose connection
exists, such as would suggest, ordinarily, a greater independence.
How is a neurokyme, which spreads over an axone, transferred from
one neurone to the others by the contact of dendritic ramifications?
Duval thinks, by an amceboid motion of the dendrites, and we read that
lately such motions have been directly observed in transparent animals.
This hypothesis seems, however, quite immature as yet. It does not
explain the extreme rapidity of the conduction of the neurokyme. The
functional play of the neurones is better explained by pure molecular
motion, as, for instance, in electricity. It would seem that these hypoth-
414 August For el :
eses are quite premature, and we must wait for actual progress in
observations.
Finally, we must maintain the fundamental fact of memory, conscious
or unconscious, viz. the residual of a dynamic trace of every nerve activ-
ity. Such a trace always facilitates the repetition of a corresponding
activity, even if it should be forgotten subsequently, and the entire
activity may be called forth again by the effect of the stimulus merely
associated with the first one ; for instance, ordinary remembrance. Or-
ganic memory is independent of consciousness and is the same for motor
as for sensory and central activities, and even for reflexes and functions
of the sympathetic.
Sleep and Waking State — Consciousness.
Man is normally limited to two states of his brain life : sleep and
waking condition. Physiologically considered sleep means a relative
rest from cerebral activity with recuperation of the exhausted neurones
by chemical sj'^nthesis, whereas in the waking state processes of oxidation
predominate. This is certain beyond doubt, but to draw the conclusion
that sleep is called forth by the formation of fatigue products, such as
lactic acid, or that sleeplessness could be cured by swallowing lactic acid,
as Preyer did, is to become a victim of fallacies.
It does not take much acuteness of observation to see that there is a
form of sleep which is not rest, and that the brain can rest fairly well
even in the waking state. Further, one may sleep much and excessively
though not exhausted, and again may keep awake in a state of cerebral
exhaustion. Again, every unprejudiced observer must be struck with
the usually rather sudden qualitative change in the attitude of a wak-
ing and of a sleeping person. That sleep is readily called forth by
certain associations, regular hours, etc., is also obvious. Finally, dreams
give us a chance to look into the life of sleep from the psychological
side.
All these factors tend to present sleep as a state of qualitatively modi-
fied cerebral activity. This is, however, only intelligible in connection
with the concept of consciousness.
It was a fundamental mistake of practically all physicians and most
psychologists, to think of consciousness as a something, as a form of cere-
bral activity, i.e. to confuse the plastic concentrative activity of our
Hypnotism. 415
attention with the purified phenomenon of subjectiveness. "We will not
quarrel over words. I, for one, am satisfied to be able to rest my view on
such a psychologist as Spencer. If any one cares to use the word
" consciousness " in any other sense, he may do so as long as he gives us
another word for that which I understand to be consciousness, viz. the
phenomenon of the inner reflection of the ego, the subjective side of the
phenomena. Slight activities of the brain, as well as violent ones, are
reflected by it and become " conscious " ; but equally violent activities
seem not to become conscious; they remain "unconscious." Conse-
quently we are forced to distinguish between a conscious and an uncon-
scious life of the brain.
The entire discord of the phenomena rests on the peculiar facts :
(1) that the activity of the brain does not take place in one single conti-
nuity and connection, that, for instance, two subjective reflexes may occur
simultaneously without being connected or " associated," so that the one
does not know of the other and one is unconscious in reference to just
that other reflex ; (2) that everything which is subjectively " forgotten "
drops out of the connection of consciousness so that amnesia and uncon-
sciousness are continually confused.
The resulting fallacies are evident ; we always call unconscious such
actions or states of the brain as were conscious and appear to us to be
forgotten, or which were illuminated by a consciousness other than our
ordinary remembered consciousness.
In order to be concise, I venture to offer a hypothesis which agrees
very well with all the facts : Every nerve activity is conscious, i.e.
possesses internal reflection ; but these reflections are by no means all
capable of remaining in a synthetical connection with one another.
For this we need a more intense associated activity, especially where the
connection is to be fixed by memory. Everything which appears no
longer, or not at all, in this connection, loses the subjective connection
with our memory ego, and we erroneously deem it unconscious, whether
it be a past or actual activity of the hemisphere, or only one of the sym-
pathetic or of the spinal cord. In order to express such a view consist-
ently we must : —
a. Eliminate the word " unconscious," and replace it by "subconscious "
or "otherwise conscious."
h. Accept a multiplicity of fields of consciousness, or consciousnesses,
the contents, i.e. the illuminated cerebral activities, of which are physio-
416 August For el:
logically connected and influence one another subjectively, according
to the kinds of activities underlying them ; they are only rarely, or
partially, or never connected (associated). That subjective associations
require higher intensity and more synthesis than the objective (physio-
logical) ones has been shown by psychology (Hoffding).
c. Consider all brain activity as completely independent of the accom-
panying (subjective) illuminations by consciousness, whether it appears to
us psychological or physiological. This is theoretically possible, at least
for psychological phenomena.
d. Consider the word " consciousness " as the expression of an inner
aspect of life, not as the name for any special thing, an activity, a
peculiarity. We use the words " energy " and " matter" in a similar way ;
there is no energy without matter, as little as matter without energy. In
the same way consciousness in our sense is nothing in itself, but merely
the subjective aspect of brain life, an aspect probably common to all life.
If we adhere to what is said, we find sleep intelligible. We observe
the following in the condition of sleep : —
1. The cerebral activity is highly dissociated. The ideas follow one
another in a chaos which does not correspond any longer to the connec-
tion of things in the actual world. Things which exclude one another in
reality appear identical, and the reverse. My friend may be at once a
dog, water, or a piece of wood. I may be simultaneously dead and mar-
ried, or simultaneously in Europe and America, or see my head before me
at a distance of twenty yards. If you study this dissociation more closely,
you readily see that it affects not only the logical sequence of higher con-
cepts, but the very make-up, even the constituents, of perceptions. The
notion of time and place, the single (usually subconscious) sensations con-
stituting a perception, are frequently disjointed, and dance together a
veritable Walpurgis dance. Again, there prevail powerful inhibitions
which prevent all orderly association and keep us in an oppressive despair
and impotence. The same chaos prevails in the field of emotions and of
volitions, but here the inhibition, or, in the emotions, powerful ebullitions
predominate.
2. The conceptions of dream life are hallucinations. When asleep we
no longer distinguish between perception and spontaneous conception.
The sensory stimuli either do not become conscious at all or they are alle-
gorized; on the other hand, all perceptions appear as actual happenings.
Moreover, the concept of a motion is usually not capable of eliciting the
Hypnotism. 417
corresponding actual muscular contraction. It is merely represented by
a motor hallucination.
3. Since there are no corrective concepts, some emotions and ideas
may, in this condition, obtain an enormous power, overcome obstacles
unsurmountable in the waking condition, and hence produce especially
intense consequences. Just think of the evil after-effects of dreams, of
nocturnal pollutions, etc.
Duval has lately ventured to make a new hypothesis of sleep. He
believes that all the terminations of the neurones are in active contact
during the waking state by some kind of amoeboid activity. During
sleep he thinks they simply withdraw, so that the contact ceases. What
a beautiful and simple explanation for all the dissociations and elimina-
tions of all the senses! For the time being this view is a mere hypothesis.
Nothing demonstrates so thoroughly the deficiencies of Weber's and
Fechner's psycho-physical law as sleep. There are too many intermediate
forces between the " subject " and the measurable external stimuli. Heer-
wagen, for instance, tried to measure the intensity of sleep by the inten-
sity of a noise necessary to wake the sleeping person ! These two quan-
tities are practically without any connection. Everything depends on
the kind of association. The same sleeping person can be aroused by a
very slight unusual sound, while the greatest noise need not disturb the
sleep. Heerwagen further tried to make statistics on dreams by asking
people for them ; but he forgot that most dreams are forgotten, and that
the forgetting of dreams and the " not dreaming " are two utterly differ-
ent things. I am convinced that everybody dreams all the night through.
I, myself, if I observe myself at all, cannot be aroused at any time of the
night without just having dreamed.
Finally, there are all degrees of sleep, from the lightest, best asso-
ciated, to the deepest. The former shows all transitions to the waking
state. The difference in the cerebral activity during the sleeping and the
waking condition implies a corresponding difference of the contents of
consciousness. We consequently have two alternating conscious states
every day and every night, and our ego is quite characteristic in each.
A good trustworthy man may become a thief, a murderer, and a licentious
person, a courageous man may be cowardly during sleep, etc. We usually
forget our dreams owing to the dissociation, so that our two states of
consciousness in sleeping and waking condition show only a slight and
fragmentary connection. Not infrequently we find somnambulists who act
2b
418 August For el:
in a coordinate manner during sleep. One who did all sorts of house-
work in her sleep was very tired after it, but did not remember anything.
This is also the rule in the very frequent somnambulism of children.
Out of such an orderly activity of a sleeping brain, i.e. out of the spon-
taneous somnambulism, originates an extraordinary and especially instruc-
tive form of double consciousness, such as has been described by McNish,
Azam, Dessoir, and myself.
In my case (see Zeitschrift fiir Hypnotismus., 1898), a German made
an eight months' journey to Australia and back without in the least
remembering it. The amnesia of retrograde and antegrade character
came on after dengue fever. Later I was able to revive the memory by
suggestions. It was, however, impossible to establish a connected associ-
ation between the two visits to Melbourne on his journey out and back.
Those two Melbournes remained for him two entirely different cities.
The Data of Hypnotism.
At all times in the history of mankind, hypnotism has played a great
r61e. Magicians, miracles, miraculous cures, sorcerers, the fakirs of
India, are so many proofs of this. The principal fact was always the
apparent and subsequently also actual power of certain persons over
others, the ecstatic catalepsy or sleep produced by them, the asserted
prophecies of the hypnotized, the cure of diseases, the miracles, etc. A
magnificent instance of hypnotic influence may be found in the history of
King Zoroaster (cf. StoU's book on this topic). In the beginning of this
century Mesmer thought to have discovered a new natural law in those
phenomena, a new " fluid," which he assumed to be magnetism. Espe-
cially in living beings he called it animal magnetism. He produced hys-
terical convulsions usually by contact of men, finally " magnetized " trees
and did other absurd things; but also cured a number of patients. Con-
demned by the French Academy as an obvious fraud, he came to a sad end.
But he retained adherents. One of them, Puysegur, discovered the quiet
hypnotic sleep. They all adhered to the belief in a mysterious magnetic
fluid. Braid, an English physician, was the first to take a great step
toward a scientific elucidation of the question. He found that the
whole series of phenomena depended not on a fluidum coming from the
outside, but on the brain and nervous system of the person influenced.
The very title of his book, " Neurohypnology," shows this. He found that
Hypnotism. 419
certain stimuli and also certain ideas could produce this changed cerebral
state, hypnotism. By this he had established the principal fact, but he
made a mistake in the method by ascribing a capital role to the periph-
eral stimuli, just as Charcot did later on. He hypnotized with brill-
iant objects, and, therefore, did not obtain thoroughgoing results.
These we owe to Liebault, at Nancy, and to his medically and philosoph-
ically highly educated friend, Professor Bernheim. The doctrine of
Liebault and Bernheim has placed hypnotism among the fields for scien-
tific research, from which it will not disappear again. This doctrine
reduces hypnotism to the concept of suggestion. In this light we shall
mention briefly the principal manifestations.
The fact that in falling asleep or awaking the entire mode of brain
activity is suddenly altered, gives us, I believe, the key to an under-
standing of hypnotism. Conceive some means by which we are able to
produce those two kinds of activity according to our needs, and, more-
over, to localize, — to limit them to certain fields, — and you see before
you almost the entire series of hypnotic phenomena. For this purpose
you should merely be able to direct the cerebral activity of your neighbor,
inhibit and facilitate, associate and dissociate. This actually happens
by means of evoking certain concepts, which are known to lead most
easily to dissociation. A priori^ this may appear peculiar and improbable.
As a matter of fact, it is exceedingly simple and common. All human
beings are naturally more or less suggestible and, therefore, hypnotizable,
although not all are equally influenced by others. Everything that pro-
duces the concept of sleep, everything that makes man passive, or throws
him into ecstas}^ admiration, or confidence, may be used by the rapid and
concentrated action of the hypnotizer to dissociate, inhibit, or stimulate,
any activity of his subject, — it may produce the desired and foretold
effect, the mechanism of which remains subconscious in the person influ-
enced. It is especially advantageous to begin with such effects as are
readily obtained. This is the principle of Liebault's method.
For instance, I yawn; it becomes "infectious." Another yawns;
with him it has the effect of a suggestive influence. He yawns because I
yawned ; however, he remains subconscious of the mechanism which pro-
duces the yawning. Now, I use the beginning dissociation, and tell him
rapidly and with assurance : " You are quite sleepy, you cannot keep your
eyes open, you cannot open them, you have a warm feeling in your feet ;
look at me ; you are already asleep, your arms are heavy," etc. Quite fre-
420 August Forel :
quently the subject will feel and even show the one or the other of these
phenomena. If he is very suggestible, he will, perhaps, be asleep in a
few seconds, to the surprise of those around. This sleep is, however, dis-
tinguished from ordinary sleep by remaining under my direction, i.e. by
my remaining in connection with the sleeper through his hearing. As
soon as I have reached this point a further mastership over his cerebra-
tion is an easy matter. I take his arm, lift it, and declare that he cannot
lower it ; and he cannot with all his efforts. I put both hands into a
rotating motion, and he cannot stop without my permission. I declare
that his hand, which I touch, is not sensitive, and no prick of a needle is
felt any longer. I give him water to drink, declaring that it is chocolate ;
he tastes the chocolate. I tell him to open his eyes, make the dead
appear before him, make him hear music which does not exist, assure him
that he is a piece of wood, another person ; in short, any fantastic non-
sense ; he feels it, believes it, lives through it. I awake him when I want
to, put him asleep by another word in a quarter of a second, and allow
him to either remember or forget everything that has been said or done
to him. In short, I make his cerebration play as in a dream, but fol-
lowing my orders, surprise himself and all the spectators, and gain with
the public the name of an accomplished magician. The whole trick con-
sists in getting, to start with, an easily suggestible person, readily
passing into somnambulism. If one is shown to be hypnotized, the
•others follow like the sheep of Panurge. The case described was that of
a person easily put into artificial somnambulism. He need not be a spon-
taneous somnambulist for this purpose. The latter are rather rare,
whereas fully twenty-five per cent of mankind can be thrown into arti-
ficial somnambulism. The spontaneous somnambulism, however, usually
represents the autohypnosis of a hysterical person.
With others the matter is slower and more difficult, although it is
facilitated by example (imitation). Many suggestions may at first be
without effect ; but with patience and practice one obtains at least a par-
tial influence in ninety-six per cent of men. The person to be hypno-
tized must be neither insane nor in a state of emotion, of excitement, or
fear. He must before all be treated in a friendly and quieting manner.
Flies are caught with honey. First you must gain his confidence. Put
him into a comfortable easy-chair, the head resting ; put the right hand on
the forehead, tell him to look into your eye, and explain to him that you
are going to let him fall asleep, or, at least, to influence him. According
Hypnotism. 421
to Bernheim, you have him look at two fingers of the left hand, after a
few seconds lower them slowly in order to make the eyelids sink and, if
the eyes do not close by themselves, you order them to be shut. Then
you begin with easy suggestions, and pass to more difficult ones as soon
as the others succeed. By no means all suggestions succeed with all
people. According to the success of the more important categories, one
may distinguish three or four degrees of hypnotism, of course with
numerous transitions: —
1. Somnambulism, in which practically everything succeeds.
2. Deep sleep, in which at least amnesia for the time of the hypnosis
is obtained.
3. Hypotaxia, in which the hypnotized yield to most suggestions, but
have the subjective feeling of being awake and remember everything
afterward.
4. Somnolence, in which only few suggestions succeed, and in which
the hypnotized can resist with some effort.
There are, however, cases of deep sleep with little suggestibility and,
again, others of simple hypotaxia with very great suggestibility, but with-
out amnesia. Moreover, the hypnotizer can at any time transfer a
somnambulist into one of the other degrees, according to suggestion.
The following are a few especially interesting phenomena which suc-
ceed chiefly in somnambulists : —
Posthypnotic Suggestions.
You declare that a certain phenomenon will take place after awaking,
during the waking condition ; for instance, he will feel, do, see, or think
some particular thing. This actually occurs as foretold in the suggestion.
Suggestion a Scheance (to take effect at a definite time).
You suggest the same thing for a later time ; for instance, the next
day or a week afterward, or even later. This, too, usually succeeds in
somnambulists with a little patience and practice.
Suggestion in the Waking Condition.
After a little practice of the subject almost every suggestion succeeds
nearly as well in the waking condition as during sleep or a somnolent
state.
422 August For el :
Not only laymen, but also many physicians, have imagined that
hypnosis and wake-suggestion are totally different things. Nobody can
show his ignorance of this question more thoroughly than by such a state-
ment. Sleep, i.e. the subjective sensation of sleep of the person hypno-
tized, is merely a generalization of the suggested dissociation in the sense
of ordinary sleep. When this generalization becomes too broad and the
hypnotizer leaves the subject, he may at times lose the " rapport " with
the subject, and when he tries to give further suggestions he may fail to
succeed or he awakes the subject, just as out of ordinary sleep. It
requires some precaution to reestablish the connection or " rapport " with-
out putting an end to the sleep. On the other hand, in a circumscribed
suggestion, in a completely waking state, it is easiest to show the symp-
tom of localized dissociation. As soon, however, as you increase the
number of suggestions, i.e. of dissociations, in a perfectly waking condi-
tion, you see how the looks of the hypnotized change, become more
dreamy ; in other words, how the dissociations become more generalized
and produce a state resembling general sleep. Beaunis and others tried
to make out that this condition in complicated wake-suggestions and that
of execution of post-hypnotic suggestions — practically the same thing —
is something peculiar, a "veille somnambulique." This is quite unnec-
essary. We are dealing merely with a more or less localized or general-
ized condition of dissociations or sleep. It is true it differs from ordinary
hypnosis, because in the latter a great part of brain-activity is not influ-
enced by the hypnotizer, viz. the spontaneous impulses of the hypnotized ;
whereas in the intentional wake-suggestions everything is governed by
the hypnotizer. Spontaneous is, of course, not to be taken in the sense
of undetermined free will, which does not exist. What we understand
by " spontaneous " is merely the resultant of all actual and past plastic
and automatic brain activities as they are inherited and developed under
the external influences during life.
Suggested Falsifications of Memory.
This is one of the most surprising illusions produced by suggestion,
described in a masterly manner by Bernheim. You suggest to some one
that he remembers accurately to have done, experienced, seen, or heard
something, while there is absolutely no truth in it. This succeeds
remarkably well. If external conditions make it possible very dan-
Hypnotism, 423
gerous false witnesses might be produced in this way. Children espe-
cially are surprisingly disposed to such suggestions ; also hysterical
women, and even normal persons. For this it does not take a professional
hypnotizer. Ordinary attorneys, and also physicians, obtain sometimes
unknowingly such suggested confessions or symptoms. Curiously enough
it is sufficient to suggest the chief points of the situation, and to leave
the rest to the imagination of the subject. He completes himself every-
thing that was missing in the suggestion given, and furnishes a mass of
precise details, which he makes up, and believes in, and by which the
deception is increased. Conscientious judges will, of course, find that
the statement does not agree with the facts ; but unfortunately sufficient
pains are not always taken. We cannot say that the witness lies ; he
speaks with the greatest conviction, and makes a deep impression on the
audience, especially on the jury.
Thus we see a series of phenomena, the beginning of which is insig-
nificant, and which all occur, more or less, in normal sleep and in certain
people, which, however, when called forth rapidly and in a condensed
form, makes a very baffling, confusing, and almost miraculous impression.
Especially confusing are the mass-suggestions, which take hold of a great
number of enthusiastic believers, produce hallucinations of all senses,
even of the tactile sense, and thus create convincing witnesses for appari-
tions, even for "materialized" spirits. Such is indeed the great tendency
of our brain toward illusions. Only the more thorough psychologists are
less surprised by these phenomena, because normal psychology has led
them already to similar concepts.
The essential feature of suggestion is evidently the production of a
sleeplike dissociation of brain activity by the means of ideas. Dissocia-
tion is used to call forth inhibition, facilitations, hallucinations, reenforce-
ment of stimuli, decisions, impulses, affects, etc. A further characteristic
feature is that the person influenced is never really conscious of the
mechanism of the actual realization of a suggestion. In a general way
suggestion makes it possible to eliminate consciousness, i.e. conscious
memory, from any phenomenon whatever, and to bring it into the circuit
again. You may make the " skin " (or rather the parts of the brain
connected with it) totally insensitive to pricks, and yet later make con-
scious the sensation which was not actually present at the moment of the
prick. Or you may produce the sensation of a prick and later make the
subject amnesic for the pain felt, so that he will emphatically assure you
424 August Forel:
that he did not feel anything, although this is not true. Again, you may
suggest the pain of a prick which never occurred. In short, a weird play
is possible with memory, consciousness, motion, and sensation in som-
nambulists.
The effect of facilitating or inhibiting suggestions goes even further.
It may involve the sympathetic, and call for, or arrest, menstrual hemor-
rhages, and influence blushing, bleeding from the nose, peristalsis, etc.
Constipation, as well as menorrhagia, can be cured as if by miracle ; per-
spiration and even the pains of labor can be influenced. Surgical anaes-
thesia is quite often easily obtained. Even blistering of the skin has
been produced by Wetterstrand beyond doubt.
All these things are continually doubted, especially by our esteemed
colleagues, the physicians, and the bona fides of the hypnotized is continu-
ally denied. They cry : Mystification ! Illusion ! I hardly care to men-
tion as a proof that I had several women controlled to whom I suggested
menstruation to take place on a definite day of each month, exactly at
7 A.M., to last three days exactly, not merely once, but after the sugges-
tion had had its regular effect for months. After all, theoretical criti-
cisms can always be made against all such controls. If, however, I submit
to your consideration the fact that the many thousands who were hypno-
tized by Liebault, Bernheim, Wetterstrand, van Renterghem, Vogt, and
myself, almost all came in order to be cured of some disorder, and
certainly not in order to deceive me, the objection that it might be hum-
bug falls naturally, especially if you consider the regularity of the
phenomena. It would be inconceivable that thousands of independent
people, who come to a physician in order to be cured, should agree on the
same story to deceive the physician in the same manner^ and to simulate
both hypnosis and cure. These considerations alone demonstrate the
absurdity of the objection. Yet if I mention cases of perfectly honorable
and loyal men and friends whom I have cured of constipation and similar
things, if I mention a professor of surgery whom I made anaesthetic and
again sensitive in a quarter of a second, not only in hypnosis but also in
the waking state, such a hackneyed objection might finally be dropped.
It is chiefly traceable to a fundamental ignorance of psychology and of the
life of the brain on the part of the majority of physicians. Universities
ought to put an end to this. It is, after all, by no means astonishing
that a dynamo weighing three pounds, as the brain does, should be able
to produce strong effects on the circulation, peristalsis, etc., by means of
Hypnotism. 425
the neurokyme current through the peripheral nerves and ganglia. And
if we are obliged to admit that an affect or a dream may have grave and
lasting psychological consequences, such as paralysis, convulsions, pains,
etc., why should not a suggestion be able to undo such consequences ?
We cannot help admitting that, so far, we have greatly underrated
the dynamic effects of the neurokyme in the brain, both on its evil and on
its good side. We must go farther and declare that many diseases which
internal medicine, gynecology, etc., have been in the habit of treating from
a local point of view are nothing but affections of the brain which ought
to be treated by suggestion alone. I merely speak of habitual constipa-
tion, of sleeplessness, of chlorosis, of most dyspepsias, and of most men-
strual disorders. And further, we must claim that a larger number of our
so-called remedies, such as electro-therapeutics, balneotherapy, many
prescriptions, etc., cure merely by suggestion, and by no means through
some imaginary specific action. The irregularity of their results, indica-
tions, and application prove this sufficiently. It must be admitted that
such a remedy gives, in many cases, a stronger suggestion than mere
verbal suggestion. In America, we ought not to forget the famous
Keeley Gold Cure for inebriates, as a beautiful instance. Since Keeley
suggested total abstinence, he was bound to have lasting results.
Let us not forget that therapeutic results of suggestion are nothing
but lasting post-hypnotic effects, which, however, like everything normal,
have a tendency to become lasting. We do not put anything new into
the body ; we merely lead the nerve paths back to the normal dynamic
course.
It is rarely possible to hypnotize a person against his will, because
confidence is the first condition of success. As soon as the hypnotized
loses confidence in the hypnotizer, the influence of the latter is usually
over. The brain does not submit any longer to voluntary dissociation,
but it associates and concentrates all its energy against the lightly built
dynamic structure.
There remain a few special points : —
Autosuggestion. — By this we mean suggestions which arise spontane-
ously, or at least without intention.
Hypnosis and Hysteria. — It was a serious blunder of Charcot, and
especially of his pupils, to mistake hypnotism for hysteria, i.e. a normal
fundamental quality of the human brain for a pathological condition. It
was, therefore, inevitable that the Paris school of hypnotism had to yield
426 August Forel :
to that of Nancy. Bernheim showed quite correctly that the so-called
great hypnosis of Charcot, with its supposed three phases appearing on
definite stimuli, was nothing but an artefact by suggestion in pathological
hysterical subjects.
Nevertheless, hysteria deserves special mention here, because its funda-
mental symptom co7isists precisely in a pathological exaggeration and degenera-
tion of dissociahility or auto suggestibility. The hysterical, men and women,
are, moreover, known to be much predisposed to convulsions, so that the
hysterical react peculiarly to hypnosis. They are, as a rule, very sensitive
to all hypnotic procedures, but exceedingly difficult to direct. They add
to every suggestion a mass of autosuggestions, begin to get convulsions
or headaches, or all sorts of other disorders which their brain adds on
account of its oversensitiveness and excessive dissociahility. So it easily
happens that for one pathological symptom removed by suggestion, auto-
suggestion favors one with three new ones. Hence, hypnosis is an
excellent, though double-edged, reagent for testing a hysterical subject.
As a rule, however, it will be possible to see after one attempt how an un-
obtrusive and well-calculated suggestion may suffice in a conversation with-
out the title " hypnosis," and in a perfect waking state. An awkward
hypnotizer, or one ignorant of hysteria, will usually do harm to the
hysterical, produce hj^sterical attacks, etc. The hysterical are apt to
pass into deep cataleptic, and even lethargic, conditions from which they
are difficult to rouse. In short, to play on them with hypnotism is play-
ing with fire. All the unintentional damage which is attributed to
hypnotism concerns hysterical subjects. I therefore tell every physician
who wants to hypnotize : " Beware especially of the hysterical, and do
not run any risk before you sit well in the saddle." Suggestion can do
much good in the hysterical, but the physician must proceed exceedingly
cautiously, individualizing, without even mentioning the word hypnotism.
Crime and Hypnosis.
This chapter was exaggerated to the extreme by Liegeois, and dealt
with too lightly by Delboeuf. That misuse, especially sexual misuse, of
hypnotized persons, may occur once in a while, is certain and possible,
especially in deep hypnosis, in hysterical lethargy, etc. Even more
dangerous is, however, the blackmailing by hysterical impostors. Hence
the rule : Never hypnotize a woman alone, without a witness. That the
Hyp7iotism. 427
hypnotized might be used for crime is theoretically possible and experi-
mentally proved. But no such case has really occurred yet. False testi-
mony through suggested falsifications of memory is about the most serious
possibility. Abnormal love-affairs of pathological persons, especially of
the hysterical or of pathological impostors, in which hypnotism plays a
r61e (case of Czinsky, etc.) rather belong to psychiatry. Of late those
suffering from paranoia and other forms of insanity show a predilection
for the delusion that they are secretly hypnotized.
Crimes through hypnosis are probably so rare because, as is said above,
confidence is the first condition of hypnosis.
The insane can usually not be hypnotized, because the instrumental
dynamo, the brain, fails to work properly, attention is defective, etc.
One can hypnotize only in one's mother tongue, or in another lan-
guage which one knows very well, for it takes, before all, great certainty
and rapidity, and a blunder in a foreign language which makes it difficult
to understand, disturbs the " rapport " considerably.
For the purpose of watching patients dangerous to themselves, I have
hypnotized the watching nurses with great success, and in this way pro-
duced a " sleeping night watch," who watches much better than a waking
person, and does not become exhausted or overtired. I hear that my
successor at Ziirich, Professor Bleuler, continues the matter with equally
good success. I give the nurse the suggestion to sleep quite well, but to
notice during his sleep every unusual action of the patient, so that he
awakes at once when the patient makes an attempt at suicide, and at once
falls asleep again when the danger is averted. In artificial somnambulism
this succeeds remarkably well.
Therapy of Nervous Diseases by Work.
Creneral Psychotherapy.
Starting from the experience that agricultural occupation is the best
for the insane, and that the natural man does not work as one-sidedly as
the " civilized," but always has, as the condition of getting along, depended
on a combination of mental occupation with muscular activity, I have tried
for a number of years to treat severe cases of so-called nervous diseases
(neurasthenia, etc.), i.e. psychopathias, with such occupations. A severe
case which I thus cured by agricultural work encouraged me. Mr.
Grohmann, a civil engineer, himself a patient, had recovered his health by
428 August Forel :
gardening, and was much interested in the matter. I encouraged him in
his attempt to occupy nervous patients in his gardens. This was the
beginning of his institution for the occupation of nervous cases, which
increased from year to year. Carpentry was added among other occupa-
tions, and very good results were obtained in severe cases. P. J. Moebius
later gave the method much support, and the data were published in the
dissertation of Menier (Ziirich), and later more fully by Grohmann him-
self.
Grohmann emphasizes the observation that a combination of his treat-
ment with suggestions by Dr. Ringier in Ziirich led very frequently to
good results.
My principal idea in the matter was that not the muscular labor as
such, but especially the centrifugal concentration of attention on deter-
mined muscular innervation for an occupation, mentally satisfying and
with a purpose, diverts the brain from pathological activities, and acts as
a cure. Stupid muscular labor, as gymnastics, dumb-bells, and turning of
the ergostat, does not give any satisfaction, and, above all, does not keep
the mind or attention from going astray. Moreover, such useless activi-
ties cannot be pursued for any length of time as a real pursuit.
Now 1 should like to go a step farther to-day, and to sketch with a
few cases a partially new chapter of psychotherapy, not touched upon by
me so far.
Not all neuropaths are fit patients for horticultural, agricultural,
or other work, nor is the pathology of brain life done justice to merely
by the ordinary suggestions of sound sleep, appetite, and like functions.
You further know that genius and insanity are somewhat related.
Whereas, however, it is well known that many a genius perished with
insanity, it is perhaps less clear to many physicians that under the picture
of hysteria or other psychopathias, many a genius, or at least many a
talent, may slumber and fret like a bird in a cage, and also that the thera-
peutic cant of neurologists paralyzes the wings of the bird instead of
liberating them. Here, if anywhere, a correct diagnosis and individualiz-
ing treatment is necessary. To be sure, not everybody who feels himself
to be a genius is a genius. The experience of the alienist must find out
of the hundreds of defective brains suffering from exaltation and mental
weakness, the few which are not really defective, but contain a wealth
of high talent, the development of which is inhibited or paralyzed by
certain disorders. If, however, you have discovered such a hidden, tied-
Hypnotism. 429
down treasure among the numerous nervous patients (brain-patients or
encephalopaths), it is your grand duty to leave the path of cant,
and to restore the wings to the eagle. Hypnosis and occupation with
manual labor may be a very helpful accessory remedy ; but they are not
the chief thing. It is necessary to gain the full confidence of the patient
by affection and by penetrating into all the sides of his mental life, to
make every fibre of his emotional life vibrate. Let the patient tell you
the story of his entire life, live it over again with him, and allow yourself
to be thoroughly penetrated by his feelings. In this you should, of
course, never forget the sexual feeling which varies so strongly from one
case to another. But it should not be examined after the ordinary medi-
cal routine, which usually considers only the seminal emissions and the
coitus ; but with full consideration of all the loftier vibrations connected
with the sexual life. This being done, you search for the real definitive
aim in the life of the patient, and lead him with determination and con-
fidence. It is a cause of much surprise to see all the psychopathologi-
cal disorders disappear as if by witchcraft, and to watch how the unhappy,
incapable, nervous wreck becomes an energetic, efficient person, who
may amaze others by his working capacity, and remains a warm friend
to the physician who understood him. A miserable person becomes
happy; a "failure," a "talent" or even a "genius"; a patient, a healthy
being.
Allow me to give briefly a few instances. My friends may recog-
nize themselves, but will pardon this publication in the interest of
mankind.
1. A highly educated young lady, the daughter of a talented father
and a very nervous mother, had the reputation of being less endowed
than her sisters, was nervous, and became more and more hysterical. She
finally developed very marked paralysis, and was brought to the hospital
for the insane. At first she was almost completely cured by ordinary
hypnosis ; but after a number of months she had a relapse, with almost
total inability to walk. She was again cured by continual agricultural
work with farmers. But she felt unhappy over not having an aim in
life. Not without hesitation I allowed her to yield to her anxious desire
to become a nurse ; her parents were much afraid of the night service.
But the latter was endured without trouble with the help of a few sugges-
tions regarding it. She took up her work enthusiastically, carried it out
with all its trials and fatigues, and became more and more active in every
430 August Ford:
direction, and to-day she is one of the most active members of a com-
mittee of philanthropic ladies, doing remarkable work.
2. A physician suffered for some time with "severe neurasthenic
disorders," and tried in vain to cure himself with all sorts of remedies.
He came to me with his complaints. I encouraged him, advised him not
to consider all those disorders, and insisted on the higher ideals of his
life. We agreed on a definite plan and he left. Later he wrote me that
by that one conversation he had been cured.
3. A young man with some hereditary taint, from a very religious
family, very talented, became " neurasthenic " and nearly insane. He
attempted suicide, and was taken to various sanitariums with complete
interruption of his studies and very gloomy prognosis. He was abso-
lutely unable to work any longer, suffered from headache, sleeplessness,
and inability to keep his attention on any mental activity. Gloomy and
in despair, he did not show any symptoms of melancholy inhibition, etc.
He was quite clear concerning his " psychopathia " and " absolute failure
in life." He also had suffered from various imperative ideas and actions
which had played him many a trick. Sexually he was perfectly calm.
He was brought to me as a case given up. Before long the talent of the
young man struck me. More intimate relations showed him to be in a
totally dissatisfied state of mind. Brought up in strict orthodoxy, he
never could believe in those religious dogmata, and therefore thought
liimself to be an outcast and lost. The forced formal training, too, with
which he was brought up was a source of disgust to him. Life seemed
aimless to him. First I calmed him concerning his religion, and showed
him that one can be a happy and valuable man without any positive
belief. Further, I showed him that learning by heart is the " mind of
the mindless," and that a mere understanding with interest stands much
higher. I told him not to try to learn anything further, but to merely
read with interest what interested him, and not to care whether he kept
it or not. In this way I revived some confidence and some pleasure in
life. He began to read his books with interest and pleasure, instead
of learning them with disgust. As a philosopher and freethinker he
returned to life, became an enthusiastic abstainer and a member of the
Independent Order of Good Templars. He helped me found new lodges.
My patient, who at first required watching for fear of suicide, soon
became my friend and associate in the work. The nervous symp-
toms disappeared, one after another. Finally he made a rather long
Hy][,notism. 431
journey alone in a tropical country, returning completely cured and with
perfect self-confidence. He resumed his studies, passed his final exami-
nation summa cum laude a few years later, was admired by all his col-
leagues for his enormous working capacity, and gives every promise of a
splendid career.
4. An hysterical lady consulted me — highly talented, but psycho-
pathic from childhood, with attacks of "grande hysteric," and greatly
excited by her living together with her mother. Notwithstanding
numerous opportunities, she did not want to get married for a number
of intellectual reasons. I tried hypnosis. Deep hysterical sleep came on
and convulsions began to show. I waked her up with much trouble,
told her boldly the result was deep beyond expectation, that she would
be cured in a short time, and that she had been only too deeply influ-
enced. From that time I gave her merely wake-suggestions. In a
few days almost all the disorders had gone, also the constipation,
and especially the convulsions (sapienti sat/}. I explained to her that
she was most in need of work and of a definite aim in life. She did
not care to found a family, with some justification, but was interested
in depraved youth. Now she started out. Instead of cures in water-
ing places, electricity, and massage, I gave her a number of books
on criminal anthropology and introductions to the directors of prisons,
of asylums, of the reformatories for children, etc. She took up the
work with enthusiasm, joined the prohibition movement and the Inde-
pendent Order of Good Templars, visited prisoners, the insane, destitute
children, showed great interest in everything, an equally good judgment,
and an astonishing working capacity. She improved every day, and
left in a few weeks for a larger city, where she wishes to continue
her studies.
In such cases, I should formerly have prescribed mental rest, inac-
tivity, manual labor, or what not. My patients did not improve. In
such cases the brain is not exhausted, as one might suppose at first sight.
It is merely misled, and works in abnormal paths ; its natural talents
starve, are inhibited, and the activity offered it does not agree with it, or
certain scruples of a religious or sentimental kind paralyze its activities,
and paths for pathological brain activity are created. This we must
recognize and change by a bold diversion.
But beware of believing every psychopath who poses as a mistaken
genius and wants to study higher philosophy. There are fifty cases of
432 August Forel : Hypnotism.
these to one of those described above. For these, agriculture is as good
as for imbeciles and the insane. True inhibited greatness is not wont to
brag or to think too highly of itself. We must look after it, must seek
it and find it. Then we can go to the root of the matter and not remain
content with mere trivial suggestions about gardening or carpentry.
A SKETCH OF THE BIOLOGY OF ANTS.
By Professor August Forel.
Together with the bees and the wasps, the real ants belong to the
insect family of hymenoptera, whereas the termites, or white ants, belong,
like the dragon-flies, to the neuroptera. All these insects live in social
organizations. More than all the rest, the ants have developed social
life most highly and variedly. This is why they deserve our special
interest. They not only present an innumerable array of individuals, but
also a magnificent variety of forms. Nearly 3000 species, divided into
154 genera, are already described from the five continents, and this number
continues growing every year.
The social state of ants has brought about a peculiar phenomenon
called polymorphism of the species. Just as the difference of sex in man
and animals is generally marked by so-called correlative differences of
organization (as, for instance, the beard in man), so we find in certain
animals that these differences become especially pronounced (compare,
for instance, the cock and the hen). In the ants, the difference of the
sexes becomes so excessive that the females and the males look like dif-
ferent animals. But that is not all. An additional differentiation takes
place in the species, in the female germs ; a certain number develop into
a second category of females with totally different shape of the body,
much diminished ovaries, without wings, but with a more highly devel-
oped brain. This specialized category of females is called the " working
ant." In many species, even a third specialization of the female sex has
formed, with powerful head and strong jaws, called "soldiers." The
females and the males are usually winged, the workers and the soldiers
always without wings. Consequently, a family or a state of ants of any
kind consists of three or four different forms of adult individuals. In
rare instances, additional forms exist. Moreover, there are many species
in which an incomplete division of the workers into two categories with
transition forms occurs (large, medium, and small workers). To these
2 F 433
434 August Forel:
we must add the young brood, which consists of eggs, the footless and
eyeless, white and tender larva? or maggots of all sizes, according to age
and sex ; and, finally, the antlike nymphs or chrysalides. In many
species, the larva spins a fine silk cocoon, which is erroneously called
the egg. The real ant eggs are extremely small, and look almost like a
white poAvder.
The architecture of the ant body shows several important social
peculiarities. The real brain, independent of the sense organs, is rela-
tively very large in the worker and the soldier, smaller in the female, and
almost rudimentary in the male, in accordance with the fact that the male
ant plays a pitiably transient and good-for-nothing role, notwithstanding
its powerful eyes and strong wings. Its immense imbecility and help-
lessness, in contrast with the well-developed senses, are a clear expression
of its lack of brain. The real brain, Dujardin's pediculated body,
possesses a highly developed, small-celled cerebral cortex, especially in
the worker.
The ants possess a social stomach or crop. It is situated at the
entrance to the abdomen, is very elastic (when it is overfed, the cubic
contents of the abdomen may be ten times enlarged), and does not digest,
since it has no glands. Its undigested contents can be vomited forth at
any time by the ant and distributed to its fellows, or to the larvae by
feeding from mouth to mouth. The mutual feeding is one of the vital
conditions of the state of ants. Behind the crop lies the chewing, or
pumping, stomach. It has four hard valves, which usually close hermetic-
ally the digestive tract of the ant. When the ant wants to eat, it opens
the valves and pumps some of the contents of the crop into its peculiar,
individual stomach, which is lined with digestive glands and where diges-
tion begins. I have demonstrated these conditions by an experiment.
I gave some honey stained with Berlin blue to a hungry ant. After it
had eaten very eagerly, I put it with a few equally hungry companions,
who at once surrounded it, begging. They all were filled with blue
droplets before long. I then dissected one after another and found that
the first stomach, filled with the blue mass, had not at first allowed a
trace of the blue fluid to pass into the chewing stomach and into the
digestive stomach. Only, during the following days, the digestive
stomach slowly became stained more and more blue.
On the fore legs the ants have a fine, spurlike comb which they use to
clean the rest of the body. This is very necessary in the busy workers.
Biology of Ants. 435
In the mouth, too, they have a comb with which they clean the combs of
the legs, the larvae, and their companions.
Of great importance are further the mandibula, or upper jaws, which
are usually dentated and serve as grasping tongue, biting weapon, mortar
spoon, carrying instrument, scissors, etc. They replace our hands, our
weapons, our scissors and knives. In the mouth they have, further, a
tongue for licking, with fine organs of taste.
The most important social organs of the ant are, however, the anten-
nfB, or feelers. They contain exceedingly delicate and numerous sense-
organs for the tactile sense and odor, terminating in hairlike structures.
The function of these sense-organs is experimentally established. It is
especially remarkable that this protruding and mobile olfactory organ not
only gives the ant information on the chemical constitution of bodies,
through contact (I called this contact-odor of the insects), but also makes
possible an appreciation of space by olfaction, owing to position and
motility, an ability which we, with our invaginated, rudimentary olfactory
organs, can form no conception of. This appreciation of space is possible,
since the different nerve endings may convey to the brain simultaneously,
or in successive moments, the impression of the various chemical proper-
ties (odors) of various objects or parts of objects, lying side by side.
Numerous relations of space are perceived for this reason, and especially,
owing to the high mobility of the feelers, not merely by contact but
already at a certain distance, at which the differences of behind and
before, of right and left, can readily be furnished by smell. This ability
must produce a knowledge of space which lies between that of our tactile
sense and that of the senses of hearing and seeing. When lately Bethe
imagined he had discovered a " polarization " of the olfactory traces of
the ants, he mistook and overlooked these conditions completely. More-
over, the ants perceive odor from a distance with their antennse. It is
experimentally established that ants recognize one another as friends or
foes merely by the means of the feelers, as Huber supposed as early as
1810; and that, in their migration, they are largely oriented, or guided, by
the feelers, although the eyes, too, help considerably in the orientation out-
side of the nest. An ant without feelers is lost, and at once excluded from
the social life; whereas without eyes it may go on working, recognizing
its companions from its enemies, and find its way, although with more
difficultj^ at least in the nest and in its near neighborhood.
Lubbock has proved that ants feel the ultra violet rays of the solar
436 August For el:
spectrum which we do not see. With the help of complicated experi-
ments (by varnishing the eyes, or by the application of aesculin which
absorbs the ultra violet rays) on the known instincts of ants, I have dem-
onstrated that they see the ultra violet rays with the eyes, not photo-
dermatically, i.e. with the skin, as many lower animals do. The flying
females, and especially the males, have good eyes, with very distinct
vision ; the workers, however, see usually but poorly.
The workers form the most important social elements of the ant com-
munity, whereas the soldiers serve for certain special functions, and the
females and males solely for the propagation of the species.
The socialism of the ants is limited to the solitary state of the ant
colony. All the individuals of one colony live up to complete solidarity,
whereas the rest of the world — with but few exceptions — and especially
all the other states of ants, even of the same species, are rather consist-
ently treated as enemies. Each state builds one or more nests. In these
the immense wealth of instinct in ants shows itself. Almost every single
species has some peculiarity in its architecture ; yea, the same species
knows how to adapt itself to the varying conditions, and to build accord-
ingly. Our most common European ant, occurring also in North America,
the small dark brown Lasius niger Linne, builds in the meadows large,
regular labyrinth-like hills of earth. In stony ground it makes its nests
under stones ; in the woods, in rotten stumps ; in houses, in rotten frames.
Most European and North American species mine in the earth labyrinth-
like complexes of galleries and rooms, where they nurse their brood.
Many build a dome of earth on it, serving, like flat stones, to take up the
radiating heat of the sun. When the sun shines in cool weather, the
ants carry their whole brood under the cupola or under the stone. Dur-
ing the night, or in rain or in hot weather, everything is carried into the
depth. The ants build with their jaws and forelegs, working up moist
earth into little lumps, during or after a rain, and making walls with
them. They are splendid masons and know how to use a blade of grass as
timber or a leaf for a roof. Occasionally a little stalk is sawed with the
teeth of the upper jaw wholly or partly bent, pulled sideways, etc. I
recommend every friend of nature to watch this activity after a warm
rain in a meadow.
Other ants with strong, hard jaws mine their nest in hard wood. In
a species living in trunks of trees (^Camponotus s. Colobopsis truncatus) a
very narrow hole leads out. It is constantly watched by a peculiarly
Biology of Ants, 437
transformed soldier — its big head just fills the hole and is trimmed
flat anteriorly, so that it closes the hole flush, like a cork. Even a
trained eye has difficulty to find the hole stuffed in this manner. A
closely related species lives in North America. Yet other species nest
under the bark of trees, under stones, in rocks or cracks of walls, even in
walls of our houses. In tropical America I found a great number of the
species in hollow, dry sticks of the brush, also in the thorns of acacia and
in hollow trees. The ant of our woods, Formica rufa^ and its next Euro-
pean and North American cousins cover a dome of fir needles, small
fragments of wood, etc., which keep warm the nest, built as a hollow
labyrinth. The gates are opened by the ants in the morning and closed
in the evening, in excessive heat frequently the reverse. Other ants
evidently use a resin-like secretion of the maxillary gland, and cement
with it meal of wood, earth, plant-fibres, and similar material to form
a sort of cardboard or pulp out of which they make wonderful nests,
either in hollow trees, as our European Lasius fuliginosus and Liometopum
microcephalum (and the North American Liometopum apiculatum'), or out-
side on branches of trees or on trunks, as we have found it in many
Central American species of Azteca and Cremastog aster.
Finally there are ants which build nests spun between the leaves of the
trees out of a fine, silk-like texture, as the species Polyrhachis and Oeco-
phylla, and in Costa Rica the Oomponotus senex s. textor. According to
the most recent observations they are said to use their larvae, which fur-
nish the thread, and which they use with the jaws as a spinning instrument.
Certain species (Formica exsecta in Europe and exsectoides in the Alle-
ghanies) form powerful states or colonies, which, according to McCook,
may consist in the Alleghanies of up to 1600 nests, which are all in friendly
relations with one another and are able to govern a whole forest.
How does a colony form ? Huber, McCook, Blochmann, and Lubbock
have established the following facts: At a certain season, the mature
young brood, the winged females and males, fly out from all the nests of
the same species. In the air, on trees, or on the tops of hills, a wild
mass-wedding takes place in which I was able to establish mutual, but
especially female, polygamy. Shortly afterward the stupid males perish
on account of inability to feed themselves. The females remove with
their own legs the loosely attached wings and creep into the earth or into
wood, singly or several together. They build a little room, lay a few
eggs, and sparingly nurse the larvae, or maggots, out of their own body
438 August Forel :
juice (they are very stout and fat) until three or four very small workers
have grown up. These begin to work at once and to feed and care for
their mother or mothers, which have nothing to do after this. The
wonderful feature is that the mother or the mothers keep so many sper-
matozoa in their seminal pocket from the one multiple copulation or
wedding, that they remain fertile for many years and are able to lay mill-
ions of eggs. They evidently remain as a rule the mothers of the entire
colony as long as it exists. At least Lubbock kept alive fertilized females
in artificial nests for eight and even eleven years, and the existence of most
colonies of ants probably does not last much longer. It is, however, not
impossible that once in a while, later on, a female brought home by the
workers, or a female of their own progeny fertilized already within the
nest, may be added to their number. Except in parasitic species, strange
females are always killed by the workers of a colony. The mothers or
queens are well cared for and fed by the workers. Their sole work con-
sists in laying eggs. A court of workers constantly surrounds the fertil-
ized female, takes charge of the eggs, etc.
The interior life of an ant colony represents the purest anarchistic
socialism. Each individual works for the community. Some build
the nest ; others clean every corner of it ; yet others nurse the brood,
feed it, clean it, and carry it, according to the temperature, into various
parts of the dwelling. Others, again, leave the nest and see to the food
supply of the community by filling first their social crop, or first stomach.
The workers serve one another attentively, feed, clean, and carry one
another, and have a mutual understanding by means of the feelers
and certain butts. The understanding, as well as the motor impulse, of
that language of signs, evidently depends on inherited instincts, and
is decidedly quite limited, but must be sufficient for the social require-
ments. The males, and usually also the females, are inactive, and are, the
former wholly, the latter largely, fed and cared for by the workers.
Toward the outside world the whole number is usually hostile to every-
thing living, which leads to offensive and defensive wars and expeditions,
the study of which is uncommonly interesting for the comparative
psychologist.
As I said before, the workers find their way outside with the help of
their sense of smell and of touch, and partly, also, with their eyes. But
this is frequentl}^ very difficult for them, and they help one another in
two ways. Individuals with especially good sense of smell (with stronger
Biology of Afits. 439
olfactory bulbs of the antennse) which have found something useful or
dangerous, come home, butt impetuously against many companions, turn
round, and are accompanied by a number of workers to the place of the
finding or of the danger, guided by means of their sense of smell. On
the way they often turn round to find out whether they are followed.
Ants with relatively poorer sense of smell return home after having found
something; take hold of a companion with the upper jaws, and induce him
to have himself carried to the new place, motionless and partly rolled up.
The carried, apparently motionless, ant sees and smells the way all the
same, even if it amounts to thirty or forty yards. She returns to the
nest herself and again brings new companions to the place of emigration.
In this way, ants which have lost their way have themselves carried home
when they meet a companion. If for any reason a colony of ants becomes
tired of its old nest, the same course is chosen. The most enterprising
workers search for new places, and the most fortunate and active ones
among them finally bring the entire colony, with its brood, to the new
site selected by them. These migrations are exceedingly instructive,
since there are competitions between two or three new sites until one is
victorious, because the ants come back from the others and reemigrate.
Every working ant is capable of doing all the labors mentioned in
turn, although many individuals, especially always the partially dimor-
phous forms of workers, usually have their preference for the one or the
other. Huber has shown, and I have found it corroborated several times,
that ants completely separated recognized one another after weeks and
months, and saluted one another as friends, merely by the help of the
peculiar olfactory organs of the antennae. This kind of memory varies
according to the species.
There are immense variations in the mode of nutrition of the ants,
and this is one of the most important causes of variety of the habits, as
a few instances will show.
The plant-lice are well known. On most of our plants we find these
tiny, succulent parasites, imbibing with their trunks the juice of the
plants, but digesting their rich and ever-present meals quite insufficiently,
so that their excrements are a clear fluid containing sugar. It is anatomi-
cally demonstrable that these clear droplets are not secretions of special
glands, but really the excrements of the lice. Most ants of our regions
are in the habit of considering the plant-lice as a kind of cattle, to look for
them everywhere, to tickle them with their feelers until the louse passes
440 Atigust Forel :
the clear drop, which is at once eagerly sipped by the ant. When no ants
are present, the louse waits longer, and finally kicks like a horse, at the
same time spurting forth the drop. By this the leaves get a brilliant
coating of sugar, the so-called honey dew. In the manner described the
ants fill their social stomach for the community. Certain species build
a dainty mason-work of stables for the lice on the roots of the plants in
their underground dwellings, and even take care of the eggs of the root-
lice. Other species build stables above ground with moist earth, and
galleries around the stalks of plants which bear leaf -lice, in order to pro-
tect their wealth in cattle against attacks by strangers. In other regions,
especially in the tropical countries, little larvse of cicadas and caterpillars
of butterflies are used in a similar way as cattle for ants. The ants
always know enough to unite their efforts, in order to lug home both
pieces of prey and larger pieces for the construction of the nest. In
America, Africa, and India there are ants (Dorylides) whose enormous
colonies live as nomads above or beneath the surface. They usually nest
for a while in the ground or in a hollow tree, whence they make enormous
expeditions for prey, in which they attack, kill, cut to pieces, and carry
home everything alive : cockroaches, rats, mice, spiders, etc. When they
attack a human habitation, all the inhabitants are forced to leave at once ;
and they are glad to do so, because within a few hours all the vermin,
big and small, are chopped up and carried away. Small children in the
cradle must be protected against the intruders and taken away. But in
return the house is free of vermin, and very soon all the ants, together
with their prey, have disappeared. In the Dorylides the huge females
are always devoid of wings and eyes ; the males, also very large, are
winged, however, and in possession of powerful eyes. In a short excur-
sion through Colombia, I could watch the expeditions of the Dorylides
species, in part at least.
Far more remarkable even is the mode of life of the ants which
raise fungi. They belong to the South American tribe of the Attini.
In their frequently very large nests these animals form caves which
reach the size of a fist. The workers climb the trees in long pro-
cessions, every worker cuts out a spherical piece of a green leaf with
its strong jaws, and thousands of them return laden with such leaves.
They have three sizes of workers : big-headed giants, minute dwarfs,
and between them a scale of medium-sized individuals. The latter are
the leaf-cutters, whereas the giants are at the same time defenders of
Biology of Ants. 441
the nests and crushers of the leaves. The harvest of leaves is prepared
into a kind of a hashed pulp, which is built up in the form of a laby-
rinth, or rather sponge. This pulp of leaves serves as culture medium
for the spores of the fungus (^Rhozites gongylophora MoUer), which are ,
present in the nest in large quantities. The leaf-pulp rapidly becomes
covered with a white film. The army of working dwarfs watch that
the fungus does not fill the nest and stifle its inhabitants. Every
growing twig or thread is at once cut off by these pigmies, hardly two
millimetres long, until the fungus gets ready to produce its second
form, which MoUer has called ant-kohlrabi, because they are little
nodes resembling miniature kohlrabi. The fungus produces immense
quantities of these kohlrabi, and the whole ant-colony lives on them.
But the nutritive power of the pulp for the fungi is not infinite. As
soon as a part of a sponge-like fungus garden is exhausted and becomes
brownish, it is torn down by the ants and thrown in small brown
grains, out of the nest, around which they form wall-like hills. In
return, these parts are continually replaced by the fresh supplies of
leaves. Thus they work continually, day and night, throughout the
year, the leaf-cutters, the leaf-crushers, and the weeders of the fungus
garden, in busy harmony, for this magnificent culture of fungi destroy-
ing the forest. They are so numerous that they give the life of the
virgin forests of South America a peculiar stamp. At every step you
come across processions of leaf-carrying ants and their nests. I my-
self was able in a short trip through Colombia to corroborate a great
part of the beautiful and careful scientific discoveries of Professor
Moller, and to discover the as yet unknown gardens of fungi of several
species and genera. Certain Attini have a rudimentary instinct of horti-
culture, and merely use the excrements of caterpillars, wood pulp, etc.
They raise another fungus. The final form of fungus of Rhozites is a
large, beautiful agaric, which grows on the nests of the ants. My
attack with spades on a nest of Atta sexdens L., one metre high and
six metres in diameter, turned into a real battle. The Indian who
helped me took to his heels. In a few seconds my hands bled all over
from the sharp bites of the large warriors. But I succeeded in un-
covering about twenty gardens in a corner of the nest. Almost every
bite of a warrior bleeds. The natives use these animals for suturing
wounds ; they have the ant bite together the two wound margins, and
then they sever the body from the head. The head remains fastened with
442 Augrist Forel :
the jaws, and closes the wound like a small forceps. v. Jhering has
shown that the fertilized females of Attini carry in the mouth a piece
of the fungus taken from the nest. In this manner they have the
germs from which their brood raises a new garden. North America has
a small horticultural ant, Atta (Trachymyrmex) Tardigrada Buckley, var.
septentrionalis McCook.
The habits of other species of ants were well known to, and inter-
preted by. King Solomon. I speak of the subgenus Messor, which lives
in masses around the Mediterranean Sea. These animals also make large
caves in the ground. They collect the seeds from all kinds of plants,
and accumulate their subterraneous granaries. There they know how
to prevent the sprouting until it is convenient for them. Then, in the
moment of beginning germination, when the starch changes into dias-
tase and sugar, they eat the grains, both in summer and in winter.
There are no real winter provisions, as Solomon thought.
In Texas there is an ant (^Pogonomyrmex molefaciens} which allows just
one kind of grass, Aristida oligantha, to grow around its nest, while aU
the other plants are weeded out. It feeds on the seeds, and is the famous
agricultural ant of Lincecum. A closely related form (P. barhatus)
makes peculiar pavements on the surface of its nest with little stones.
Other ants (^Myrmecocystus melliger and Mexicanus) use part of their
workers as provision-pots. These ants are so overfed by the other
workers that their first stomach or crop reaches the size of a wine-grape,
and correspondingly distends the abdomen. These so-called "nurses"
cannot walk any longer, and hang in the subterraneous spaces as pro-
vision-pots for the community. Types of this kind live in Mexico,
Colorado, and Texas, and are dug out and eaten by children. McCook
has studied their habits.
A topic worthy of admiration is the so-called symbiosis of a South
American ant, Azteca Mulleri, with the Cecropia tree Imbanba ( Cecropia
peltata). The tree is hollow inside. On peculiar cushions of the
shoulders of its leaves it produces granules rich in albuminous substance
and not present in other Cecropias (MiiUer's granules). The ant lives
in the hollow space of the Cecropia, where the mother of the colony digs
into an apparently specially adapted, thinner portion. In this tree the
Azteca finds a home and its food in the granules of Miiller. But it is
very bellicose. As soon as the leaf-cutting ants, just mentioned, attack
the Cecropia, the furious Aztecas defend the tree and throw them back.
Biology of Ants. 443
With what fury the Azteca species defend their trees with the help of a
very odorous, resinous substance secreted by the anal glands, I have been
able to see repeatedly in Colombia, where some live in self-made pulp-
nests, hanging on the branches of trees, others in the Cecropias and other
hollow trees, and one even under the flat leaves of a kind of ivy. The
symbiosis of Azteca Mulleri with the Cecropia peltata is, however, incom-
plete, inasmuch as a complete mutual dependence of the two organisms
does not exist ; the Cecropia, at least, can live without the ants, at least
in its first years. But the symbiosis of the fungus Rhozites gongylophora
with the Atta species is complete. Neither fungus nor ant can live by
itself ; each is absolutely dependent on the other.
The ant nests have their parasites and domestic animals like the dwell-
ings of man. Certain lice and worms trouble the ants, and lay their
eggs into their brood. There also exist very wonderful relations between
certain beetles, lepismas, centipedes, etc., and the colonies of ants.
They are called guests, although as a rule they are rather harmful lodgers
for the ants. They are tolerated or even loved by the ants on account of
a certain odor or pleasant secretion of their hairs, which the ant licks
passionately. They live as members of the colony in the ant nest, and,
as Wasmann has so well described and Janet corroborated, take the habits
of ants. They are fed by the ants from mouth to mouth, and even
feed each other. They communicate by means of their feelers with
the ants, and with one another. Even their brood is usually fed and
raised mostly by the ants as if they were their own. Long ago I
observed the feeding, transportation, and nursing of the larvae of Atemeles
(a beetle living with the ants), and wondered why the ants cared for
these strangers just as for their own brood, without, however, knowing
then that these larvse belonged to the same beetle which is a guest of the
ants as an adult. Wasmann has proved this ; he also has demonstrated
the harmful influence of these guests on the ant colony which begins to
produce pathological malformations between the worker and female,
described by me formerly without a knowledge of the cause.
Other guests are rather mischievous thieves, which creep into the
nests and eat the ants or their brood (Myrmedonia)^ or merely in order
to eat the excrements of ants (Binarda). The excellent biologist, Was-
mann, knew that in migrations of a colony of ants to a new nest the
whole gang of little guests (beetles, centipedes, epismas) know how to
follow the ants into the nest, following the trace by their sense of smell.
444 August Forel:
I myself have corroborated this observation. This is, however, not the
case with the small, round TJiorictus Foreli living in the nests of the large
and long-legged Myrmecoeystus megalocola in Algeria. It is too small
and too slow to be able to follow the swift ant. Consequently this beetle
(discovered by me in Algeria, and called after me by Wasmann) always
clings to the shaft of the feeler of the ant, and is carried in this way. A
peciiliar notch in the head-shield allows it to wholly embrace with its
jaws the feeler of the ant without hurting it. Lately Wasmann believed
that he found that the beetle bores a hole into the shaft of the feeler of
the ant with its lower jaws and suck its blood. But Escherich denies
this, and the matter is not settled.
Even more remarkable than the relations of these guests are the
slaves and the friendly relations of some species of ants to one another.
Many years ago I accidentally discovered that some of our ants (for
instance, Formica rufa^ the common ant of our forests), which usually
live by themselves and work hard, in very exceptional cases, probably
after a war in which they were victorious, let the chrysalides of other
weaker species (Formica fusca') hatch, rear them, and consider them as
members of their community. This is the origin of the rare mixed
colonies which give the explanatory history of evolution in the animal
series for the following long-known fact. Charles Darwin had theo-
retically surmised that mode of origin of the instinct of slavery in ants.
The Formica sanguinea, as Huber first discovered, is almost always in
the habit of making irregular raids in June, July, and August, in which
they surround the nests of Formica fusca, attack this weaker species,
and chase away after a violent struggle the inhabitants of the nest, whose
brood they seize and carry home. The larvse and chrysalides, kidnapped
in this manner, hatch in the nests of the sanguviea, where they feel at
home very much as kidnapped infants. There they render the greatest
service as workers to the robbers, so that the latter, although also rela-
tively active, lead an easier and more insolent life of prey than their
nearest relations. This gives the Formica sanguinea a very peculiar,
enterprising, and intelligent biological stamp. It is taken up by the
daily labor much less than other species. The so-called slaves, or better,
helpers, feel themselves so well at home that they do not recognize their
real brothers and sisters from the robbed nest, and treat them as enemies.
It is established that the ability of ants to recognize begins only a few
days after the hatching of the chrysalis, when the soft chitine is getting
Biology of Ants. 445
harder. In order to show this, I have put together larvae and new-born
ants of various species and genera, and raised a mixed but peaceable
colony. In North America there are families of Foi'mica sanguinea
(^ruhicunda Emery, etc.) which have similar habits.
The Amazon ant of Huber (^Polyergus rufescens) has developed fur-
ther the system of slaves. Their dagger-shaped, bent jaws are already
unfit for work. Like a Macedonian phalanx, its rust-colored army, con-
sisting of usually from 300 to 1200 ants, rushes from its nest on summer
afternoons. In a close array and forced march it follows the path pre-
viously reconnoitred by a few robbers, and in one half to one hour it
covers distances of from fifty to one hundred metres. It is true the army
often loses its way or stops until a few ants have found it again, rapidly
butt with their heads against the others, and give them the sign to follow.
If not, the swarm returns unsuccessfully. As a rule, however, they reach
a nest of Formica fusca or rufibarbus, rush with an incredible haste into
the entrances of the nest, and sack in a few minutes the entire brood of
the unfortunate, overpowered ants in order to run home, and to throw the
prey simply to their helpers. The observation of such an expedition is
probably the most interesting zoological spectacle I ever have witnessed.
I have observed them very often in the canton of Vaud, and kept statis-
tics on the number of expeditions, of the soldiers, of the robbed nests, and
the rapidity of the march. The Amazon ant completely depends on its
helpers. Their entire brood is fed and cared for by them. Yea, the
robber cannot even eat without help, and starves, as Huber and I have
shown, in presence of the richest food, if it is not poured into its
mouth by the helpers. It is able to swallow if its mouth happens to get
into honey ; but the instinct to eat has been lost. The North American
Polyergus lucidus (which robs Formica pallida falva^ and breviceps have
the same habits.
The little genus Strongylognathus shows how the instinct of robbing
slaves can slowly develop into parasitism. In 1871, I discovered a new
species in Wallis, Strongylognathus Huberi^ and I was able to show on
the spot by an experiment that it can rob like Polyergus. The more
frequent and smaller Strongylognathus testaceus, however, cannot do this
any longer. This small and weak animal, in which the workers are
dying out, according to my observations, still shows ridiculous remnants
of the fighting tactics of its relatives. Wasmann has proved that the
fertilized female of this ant sneaks into the nests of another kind.
446 August Forel :
Tetramorium ccespitum^ is received by the workers beside the Tetramorium
mother, and lives beside her. For some cause the Tetramoriuras raise
from that time on the workers of their own species only ; whereas they
allow the larvae of the males and females of their own species to perish ;
instead of this they raise the whole brood of the Strongylognathus mother,
perhaps merely since it causes less trouble and work.
At last the parasitism of the Anergates atratulus goes even further,
they having become totally devoid of workers. Here the fertilized
female of Tetramorium ccespitum is received ; whereas the own mother
of the colony of this species disappears in a manner not yet explained.
As long as the existing workers live, they nurse the entire brood of the
Anergates female, consisting merely of winged females and wingless
males. The Tetramorium workers from that time merely work for the
parasites. The females of Anergates are fertilized in the nest by their
own brothers ; not till then do they fly out to found new nests. In
this manner the species is subject to continued inbreeding, since there
is always only one mother in a nest ; but it does not seem to suffer
from it. In North America, Epoecus Pergandei lives as a parasite with
Monomorium minutum. But nothing definite is known of its biology as
yet.
Another ant, Formicoxenus nitidulus Nyl., lives as a small but active
tolerated guest with its entire brood in the partitions of the nests of the
common wood ant. It also lives in the Rocky Mountains.
The northern Tomognathus suMcevis, however, according to Adlerz,
penetrates as a brutal, uncalled-for guest into the nest of a weaker ant
(^Leptothorax acervorum}, and forces its brood on these animals, more-
over allowing itself to be lazy and comfortable and fed by the host.
The wingless worker of Tomognathus is at the same time female ; the
male is winged. Tomognathus Americanus from Washington probably
lives in a similar manner.
The tiny but warlike Solenopsis fugax lives in very small rooms and
channels, which it burrows into the partitions of the nests of larger ants ;
but it lives there as an enemy, robber, and thief, sneaking among the
brood of the larger kind and eating it up. Since my first publication of
this point in 1869, it has become known that this manner of living occurs
in a large group of the Solenopsis species and related genera, such as
^romyrma, certain Monomorium species, etc., which all represent, in this
manner, small robbers hidden in the walls of the nests of larger species.
Biology of Ants. 447
It seems that in North America Solenopsis modera^ pollux, and molesta live
in a similar manner. In Africa and India the Carehara species live in the
same way in the nest of Termites, also .^hromyrma in Madagascar.
In the Colombian virgin forests, I discovered in 1896 a new, previ-
ously unknown relation of two ant-colonies, which I called parabiosia.
A small Dolichoderus and a still smaller Cremastogaster, both of a deep
black and glossy, live usually, though not always, together in the follow-
ing manner: They inhabit the same nest, probably robbed from a species
of Termites. The cavities and galleries are all in open connection, and
are inhabited by the two species in a mix-up, almost inextricable to the
human eye. This much is certain, that the two species do not mix. Each
occupies definite rooms and galleries, and cares for its own brood only,
notwithstanding the open communication. But there is peace, never
war ; in common expeditions, the two species leave the nest in order to
find food on plants and trees, but only to the point where the final aims
divide ; there they separate, and each species goes on to its special aim
(the plant-lice or flowers). Thus we have a peaceable symbiosis without
mixing and without any intimate relations. The relation of guests might
well be called "Xenobiosis," the helpers' relation "boethobiosis." These
expressions would be preferable not only among ants, but also for analo-
gous relations of other animals. Wasmann's expressions (" Symphilie,"
etc.) are, however, preferable. Apart from the raids and the other con-
ditions described, the ant colonies, even those of the same species, have
warfare usually about the source of nutrition. We men believe our-
selves the sovereigns of the earth. Obviously, the ants do the same in
their little world, since the larger colony considers a certain district
around its nest as its property. This district comprehends trees, plants,
and the soil ; whoever enters it is attacked, and, if possible, slain. Hence
the wars between neighboring colonies, wars which are often carried to
the annihilation of the weaker part. A victory is accounted for by the
number and courage of the warriors, and also by certain weapons, as
stings, poison-sacks, hardness of body, swiftness, resinous secretions of
the anal glands which are spurted out, certain tricks, as for instance in
Polyergus the piercing of the brain of the enemy, in Formica exsecta the
sawing off of the neck, or the like. The smaller kinds usually take hold
of the legs of the larger ones, seize them this way, and finally kill them by
the number of their pricks or bites ; whereas the big ones cut or crush the
small with their jaws. Whole chains of combatants are formed, of which
448 August Forel :
few may survive the battle. Slowly the victor gains ground, until the
enemy either faces about or finally is surrounded in its own nest, chased
away, or killed with its entire brood. Besides such larger wars, which
may last days or weeks, there are innumerable skirmishes along the fron-
tiers, especially about the possession of plant-lice.
Yet ants do not merely murder and carry on warfare ; they also can
make peace. This does not only happen because two exhausted colonies
often give up fighting and avoid a certain strip of contested land, but
also, in rare cases, by coalition and complete union. I have produced this
experimentally by mixing rather large parts of nests of various colonies of
Formica fusca with their inhabitants, or at least putting them close
together in a strange place, where they were forced to build a new nest.
Necessity and circumstances, the mutual need for food and habitation,
reduced the warlike impulses. After usually insignificant threats, taunts,
and weak attempts at fighting, the ants began to work together, and in
the course of one or two days formed one harmonious colony. If, how-
ever, you bring part of a colony near the nest of another one, it is driven
away and often annihilated.
Once (1871) I poured the inhabitants of two colonies of very hostile
different kinds (^Formica sanguinea and pratensis) into one bag and
allowed them to struggle one hour, in order to put them into connection
with an artificial glass-nest. Fighting, with the greatest excitement and
total confusion, the ants reached the glass-nest where they carried their
larvae. Necessity gradually reduced the fever of the battle. The next
day several hundred had killed one another ; the survivors began to work
together, though defiant and threatening. A few kept up the fighting
spirit. After five days the union was perfect. Ten days later I allowed
them to get out on the meadow, where they built a common nest and after
that lived in undisturbed friendship. When, however, I put a few ants
from the original nest of the pratensis with the new allies, the new arrivals
were kindly received by their former sisters, but fiercely attacked and
partly killed by the sanguinea. This case is very instructive, and shows
that the sanguinea had closed friendship with only the definite set of
pratensis., and were quite well able to distinguish them from the, as yet,
unknown sisters.
The instinctive feeling of duty of the workers has been illustrated by
me in the following manner : One meter from a nest of Formica pra-
tensis^ I placed a strong portion of a strange colony of the same kind.
Biology of Ants. 449
Th^y soon began the attack, and a great battle began, lasting several
hours and costing nearly a thousand lives on the two sides. While the
inhabitants of the nest rushed out to the defence of their home, I poured
honey quite close to the soldiers running into the battle. Under ordi-
nary circumstances the honey would have become black with ants in a
short time. But the workers passing by sipped for only one or two
seconds, could not be tempted any longer, and rushed into the combat —
as a rule into death — although the ants have neither criminal law nor
court-martial. Whoever wants to be a coward or egoist may do so with-
out any interference. But the ant cannot act or will antisocially, and
this is the secret of their socialism. In the struggle between the individ-
ual instincts and impulses against social ones the latter usually have the
upper hand. There are, of course, short hesitations which are very in-
structive to observe.
As has been said already, the community of ants realizes the purest
ideals of our modern anarchists. No government, no king, no laws, no
bureaucracy, no officials. Nobody commands, nobody obeys. Even the
so-called slaves are perfectly free and work voluntarily, from mere in-
stinct. Hence, absolute freedom with absolute solidarity. When a
worker wants to be lazy, he is cared for none the less (this is seen in the
Amazon ant, which is totally dependent on its "slaves"). But this laziness
does not occur at all, except with the slave-makers and the parasitic species.
Consequently there are no 'cracies, no parties, no rebellions, no crimes ;
at least almost none (and we must remember no alcoholism either) ; at the
most only occasional individual differences which, however, are almost
always quite short and insignificant. ^ And yet, there is the most perfect
order, indeed, a wonderful skill to create order by harmonious, energetic
work in a short time, in the most difficult and confused situations possible.
If, for instance, you demolish brutally a nest of ants, take all the inhabi-
tants into a bag, and throw them in a completely unknown region amidst
1 1 have described one exception in my "Fourmis de la Suisse" ; a mixed colony of
Amazon ants suffered for lack of food, owing to prolonged drought. Then I saw how a few
helpers (slaves), importuned for food by the Amazons, would bite their "masters," and
finally carry them as far as possible to throw them away. The hard Amazons took it good-
naturedly, but always returned home at once. Tired of such a Sisyphus labor, one of the
helpers began to bite, so that an Amazon lost patience, pierced the brain of the rebellious slave,
and thereby killed it promptly. This fact is quoted by the famous criminal anthropolo-
gist, C. Lombroso, and has been interpreted as a case of crime among ants. This interpreta-
tion stands discussion, and the case is certainly instructive.
2g
450 August Forel :
enemies, they reconnoitre rapidly, gather the brood, find a place for a
nest, hide the brood provisionally under leaves or in the hole of a cricket ;
the enemies are kept away, the nest built, food, especially plant-lice, is
sought for and found, etc.
The wonderful and manifold social instincts of ants have called forth
many erroneous views, and produced a sort of anthropomorphism of the
ant's mind. There are, indeed, enough analogies and points of contact be-
tween the society of man and of ants, — slavery, raising of cattle, horticulture,
war, treaties, etc. These are phenomena of convergence, the complicated
connection of which in both ant and man is brought about by the fact
of social community of living brains. The chief difference lies in the
inherited automatism of instinct in the ant, and the immensely individual
plasticity of the human brain. You may ask how it is that the brain of
an ant, only the size of a pin-head (Charles Darwin calls it the most won-
derful atom of substance of the world), can do as complicated things as
the human brain, which weighs two and one-half to three and one-quarter
pounds ; but you must consider the other side of the matter, namely, the
immense limitation of an ant as soon as it ought to do something that
does not lie in its inherited instinct. We see the Amazon ant, which has
such complicated ways of plundering, perish beside ample food although
it can lick and swallow, because it has lost the instinct to eat. Every
species has its special tricks, but only those, and it never devises anything
else. It is true, that ants adapt themselves to new conditions to some
extent, and better than other insects, because their brain is relatively a
little larger ; but this is the case only in a very limited manner. In its
whole life, an ant learns almost nothing apart from a certain knowledge
of places, and the ability to distinguish other ants ; shortly after it comes
forth from its chrysalis it knows almost all it will ever know, innate and
inherited ; whereas the mammals, and even the birds, learn very much
during their lives, have far more memories, and combine and use them.
Hence, it follows that mental or cerebral activities which are one-sidedly
complicated, fixed in the brain and inherited, necessitate far fewer brain
elements than the ability to learn individually to combine, to adapt itself,
to practise new activities, and to make them become secondarily automatic
by practice. This ability, which may be called plastic in comparison
with the automatism of instinct, especially distinguishes the human brain,
although even we think and feel and act far more from inheritance than
we believe. Still there is no actual contrast between instinct and the
Biology of Ants. 451
plasticity of reason. There rather are thousands of transitions, especially
the so-called hereditary dispositions, which are, so to speak, rudimentary,
not completely developed instincts, and which, for instance, distinguish a
Mozart or a Koszalzki, who were able to become virtuosi and composers
as children, from unmusical persons over whom all the teachers labor for
years in vain.
The animals with complicated high instincts are, therefore, by no
means more stupid than those which have only slight instincts. All
depend on two different modalities of brain activity which may go, side
by side, to a varying height, without excluding one another mutually.
As I wrote over twenty-five years ago, the community of ants teaches
us further that the social state of man cannot be arranged after the pat-
tern of the ants. Man has too much and too little for this. He lacks
the sexless workers, the social first stomach, and, above all, the high social
instinct which, without any legal compulsion, works much rather for the
community than for itself. In return, he can receive, digest, and combine
in his powerful brain a world of plastic concepts, which the little ant,
with her automatic, one-sided, though extremely well-built and remarka-
bly well-used, brain is unable to do. The highly developed human brain
contains an unlimited number of plastic powers, capable of development,
connected with overpoweringly strong inherited egoistic instincts and pas-
sions of animals of prey, but capable of being influenced in manifold
manners by selections and by individual adaptations. Man and his brain
cannot be forced into one single collective or anarchistic dogma, because
overwhelming impulses lead him forcibly toward a higher evolution,
which cannot be defined beforehand. We are, of course, in a position to
recognize, to some extent, the laws of this psychical evolution, especially
by the help of history, of ethnology, of psychology, connected with
anatomy and physiology of the brain, and to remove, in a negative man-
ner at least, that which deranges and inhibits it, as the use of alcohol, of
opium, the cult of the golden calf and of illusory gods, and other causes
of degeneration, and to try positively to increase the number of the fittest
germs at the expense of the unfit. But, unfortunately, the higher insight
of man has to meet continually the obstinate narrowness of prejudice, so
that the victory of truth is not easy.
Notwithstanding the difference of their physical organizations and
size from ours, with all their relatively low rank in the animal series, the
ants, with their social biology and psychology, are an extremely valuable
452 August Forel : Biology of Ants.
and interesting object of comparison, both of living nature and of the
social relations of man, and for human psychology generally. They
prove how the eternal, divine powers of nature produce equal or similar
phenomena in completely different ways, whether they be those of living
beings in their various combinations, or those which are called the physico-
chemical powers of inorganic and organic nature. Have not slavery, the
raising of cattle, and horticulture been practised by ants long before there
were any men on earth ? These ants very probably have acquired these
arts in the way of natural selection, automatically, in the course of innu-
merable generations, with the helps of inherited combinations, without
there ever having existed an ant which could have got a perspective of
the adequacy of the process, individually. Man, however, invents indi-
vidually, with the help of innumerable combinations of plastic impulses,
and he often devises, individually, things which long before had been pro-
duced by natural powers, or living beings before him. Let me mention
the sail long used by the nautilus, electricity, etc.
In Proverbs vi. 6-8, we read : " Go to the ant, thou sluggard ; con-
sider her ways, and be wise ; which having no guide, overseer, or ruler,
provideth her meat in the summer and gathereth her food in the harvest."
To this sentence, which is scientifically true, word for word, I add the
following : She gives man the social doctrines of work, of harmony, of
courage, of sacrifice, and of a spirit of solidarity.
DEGREES CONFERHED.
Following are the degrees conferred by the University during its first
decade. In case of the degree of Doctor of Philosophy, the subject of
the dissertation and the date of the examination are given.
DOCTORS OF PHILOSOPHY.
MATHEMATICS.
J. W. A. Young, Sept. 16, 1892.
On the Determination of Groups whose Order is a Power of a Prime.
American Journal of Mathematics, April, 1893, Vol. 15, pp. 124-178.
William H. Metzlek, Jan. 4, 1893.
On the Roots of Matrices.
American Journal of Mathematics, Oct., 1892, Vol. 14, pp. 326-377.
Thomas F. Holgate, May 9, 1893.
On Certain Ruled Surfaces of the Fourth Order.
American Journal of Mathematics, Oct., 1893, Vol. 15, pp. 344-386.
John E. Hill, June 17, 1895.
On Quintic Surfaces.
Mathematical Review, July, 1896, Vol. 1, pp. 1-59.
L. Watland Dowling, June 19, 1895.
On the Forms of Plane Quintic Curves.
Mathematical Review, April, 1897, Vol. 1, pp. 97-119.
Thomas F. Nichols, June 20, 1895.
On Some Special Jacobians.
Mathematical Review, July, 1896, Vol. 1, pp. 60-80.
Warren G-. Bullard, June 17, 1896.
On the General Classification of Plane Quartic Curves.
Mathematical Review, Vol. 1, pp. 193-208, 3 plates.
Frederick C. Ferry, June 15, 1898.
Geometry of the Cubic Scroll of the First Kind.
Archiv for Mathematik og Naturvidenskah, B. 21, Nr. 3.
453
454 Degrees Conferred.
Ernest W. Kettger, June 16, 1898.
On Lie's Theory of Continuous Groups.
American Journal of Mathematics. (In press.)
John S. French, March 28, 1899.
On the Theory of the Pertingents to a Plane Curve. (In press.)
PHYSICS.
T. Proctor Hall, June 19, 1893.
New Methods of Measuring the Surface-Tension of Liquids.
Philosophical Magazine, Nov., 1893, Vol. 36, pp. 385-413.
Clarence A. Saunders,^ July 6, 1895.
The Velocity of Electric Waves.
Physical Review, Sept.-Oct., 1896, Vol. 4, pp. 81-105.
Thomas W. Edmondson, July 11, 1896.
On the Disruptive Discharge in Air and Liquid Dielectrics.
Physical Revieio, Feb., 1898, Vol. 6, pp. 65-97.
Samuel N. Taylor, July 31, 1896.
A Comparison of the Electromotive Force of the Clark and Cadmium
Cells.
Physical Review, Sept.-Oct., 1898, Vol. 7, pp. 149-170.
Albert P. Wills, June 21, 1897.
On the Susceptibility of Diamagnetic and weakly Magnetic Substances.
Physical Review, April, 1898, Vol. 6, pp. 223-238.
William P. Botnton, June 23, 1897.
A Quantitative Study of the High-Frequency Induction Coil.
Physical Review, July, 1898, Vol. 7, pp. 35-63.
CHEMISTRY.
Thomas H. Clark, June 13, 1892.
The Addition-Products of Benzo- and of Toluquinone.
American Chemical Journal, Dec, 1892, Vol. 14, pp. 553-576.
John L. Bridge, Jan. 8, 1894.
Ueber die Aether des Chinonoxims. (p-Nitrosophenols.)
Liebig's Annalen, Sept., 1893, Vol. 277, pp. 79-104.
Julius B. Weems, June 20, 1894.
On Electrosyntheses by the Direct Union of Anions of Weak Organic
Acids.
American Chemical Journal, Dec, 1894, Vol. 16, pp. 569-588.
1 Died Dec. 19, 1898.
Degrees Conferred, 455
BIOLOGY.
Hermon C. Bumpus, Sept. 29, 1891.
The Embryology of the American Lobster.
Journal of Morphology, Sept., 1891, Vol. 5, pp. 215-262, 6 plates.
William M. Wheeler, May 10, 1892.
A Contribution to Insect Embryology.
Journal of Morphology, April, 1893, Vol. 8, pp. 1-160, 6 plates.
Edwin 0. Jordan, May 11, 1892.
The Habits and Development of the Newt.
Journal of Morphology, May, 1893, Vol. 8, pp. 269-366, 5 plates.
James R. Slonaker, June 20, 1896.
A Comparative Study of the Area of Acute Vision in Vertebrates.
Journal of Morphology, May, 1897, Vol. 13, pp. 445-502, 5 plates.
Colin C. Stewart, June 19, 1897.
Variations in Daily Activity Produced by Alcohol and by Changes in
Barometric Pressure and Diet, with a Description of Eecording Methods.
Journal of Physiology, January, 1898, Vol. 1, pp. 40-56.
PSYCHOLOGY.
Herbert Nichols, Sept. 29, 1891.
The Psychology of Time, Historically and Philosophically Considered with
Extended Experiments.
American Journal of Psychology, Feb., 1891, Vol. 3, pp. 453-529 ; April,
1891, Vol. 4, pp. 60-112.
Alexander F. Chamberlain, March 9, 1892.
The Language of the Mississaga Indians of Skugog. A Contribution to
the Linguistics of the Algonkian Tribes of Canada.
MacCalla & Co., Philadelphia, 1892. 84 pp.
William L. Bryan, Dec. 13, 1892.
On the Development of Voluntary Motor Ability — with a Preface on the
Requirements of Work in Experimental Psychology.
American Jou.i'nal of Psychology, Nov., 1892, Vol 5, pp. 125-204, 3
charts.
Frederick Tracy, May 29, 1893.
The Psychology of Childhood.
D. C. Heath & Co., Boston, 1893. 94 pp.
Arthur H. Daniels, June 21, 1893.
The New Life : A Study of Regeneration.
American Journal of Psychology, Oct., 1893, Vol. 6, pp. 61-106.
456 Degrees Conferred.
John A. Bergstrom, May 14, 1894.
An Experimental Study of Some of the Conditions of Mental Activity.
American Journal of Psychology, Jan., 1894, Vol. 6, pp. 247-274.
Fletcher B. Dresslar, June 14, 1894.
Studies in the Psychology of Touch.
American Journal of Psychology, June, 1894, Vol. 6, pp. 313-368.
Thaddeus L. Bolton, April 30, 1895.
Rhythm.
American Journal of Psychology, Jan., 1894, Vol. 6, pp. 145-238.
Frank Drew, July 29, 1895.
Attention : Experimental and Critical.
American Journal of Psychology, July, 1896, Vol. 7. pp. 533-573.
James H. Leuba, July 29, 1895.
A Study in the Psychology of Religious Phenomena.
American Journal of Psychology, April, 1896, Vol. 7, pp. 309-385.
Colin A. Scott, June 30, 1896.
Old Age and Death.
American Joui-nal of Psychology, Oct., 1896, Vol. 8, pp. 67-122.
Ellsworth G. Lancaster, June 11, 1897.
The Psychology and Pedagogy of Adolescence.
Pedagogical Seminary, July, 1897, Vol. 5, pp. 61-128.
Ernest H. Lindley, June 12, 1897.
A Study of Puzzles with Special Reference to the Psychology of Mental
Adaptation.
American Journal of Psychology, July, 1897, Vol. 8, pp. 431-493.
A. Caswell Ellis, June 18, 1897.
The History of the Philosophy of Education. (In press.)
George E. Dawson, August 2, 1897.
Psychic Rudiments and Morality.
American Journal of Psychology. (In press.)
Edwin D. Starbuck, August 3, 1897.
Some Aspects of Religious Growth.
American Journal of Psychology, Oct., 1897, Vol. 9, pp. 70-124.
Frederic Burk, June 8, 1898.
From Fundamental to Accessory in the Development of the Nervous Sys-
tem and of Movements.
Pedagogical Seminary, Oct., 1898, Vol. 6, pp. 5-64.
Linus W. Kline, June 10, 1898.
The Migratory Impulse vs. Love of Home.
American Journal of Psychology, Oct., 1898, Vol. 10, pp. 1-81.
Degrees Conferred. 457
J. Richard Street, June 11, 1898.
A Genetic Study of Immortality.
Pedagogical Seminary, Sept., 1899, Vol. 6, pp. 267-313.
Daniel E. Phillips, June 13, 1898.
The Teaching Instinct.
Pedagogical Seminary, March, 1899, Vol. 6, pp. 188-245.
Frederick W. Colegrove, June 13, 1898.
Individual Memories.
American Journal of Psychology, Jan., 1899, Vol. 10, pp. 228-255.
Henry S. Curtis, June 16, 1898.
Inhibition.
Pedagogical Seminary, Oct., 1898, Vol. 6, pp. 65-113.
Frederick E. Bolton, Aug. 15, 1898.
Hydro-Psychoses.
American Journal of Psychology, Jan., 1899, Vol. 10, pp. 171-227.
Henry H. Goddard, June 12, 1899.
The Effects of Mind on Body as evidenced by Faith Cures.
American Journal of Psychology, April, 1899, Vol. 10, pp. 431-502.
The following gentlemen have taken the examination for the doctor's
degree, but have not yet completed all the formal requirements.
Eugene W. Bohannon,
Edmund B. Huey,
Cephas Guillet,
George E. Partridge,
Charles H. Walker.
DOCTORS OF LAWS.
HONORIS CAUSA.
LuDwiG BoLTZMANN, July 10, 1899.
Professor of Theoretical Physics, University of Vienna.
Santiago Ramon y Cajal, July 10, 1899.
Professor of Histology, and Rector of the University of Madrid.
August Forel, July 10, 1899.
Late Director of the Burgholzli Asylum, Switzerland.
Angelo Mosso, July 10, 1899.
Professor of Physiology, and Rector of the University of Turin.
i^MiLE PicARD, July 10, 1899.
Professor of Mathematics, University of Paris.
TITLES OF PAPERS
Published by Past and Present Members of the Staff,
Fellows, and Scholars.
H. AUSTIN AIKINS: —
B.A., University of Toronto, 1887 ; In-
structor, University of Southern Cali-
fornia, 1888 ; Graduate Student, Yale
University, 1888-91 ; Lecturer on History
of Philosophy, ibid., 1890-91 ; Ph.D.,
Yale University, 1891 ; Professor of Logic
and Philosophy, Trinity College, North
Carolina, 1891-92 ; Fellow in Psychol-
ogy, Clark University, Oct., 1892-
Jan., 1894 ; Professor of Philosophy,
. College for Women, Western Reserve
University, Cleveland, O., Jan., 1894-.
Author of : —
The Philosophy of Hume, in extracts, vrith
Introduction. (Sneath's Series of Mod-
ern Philosophers.) Henry Holt & Co.,
N. Y., 1893. 176 pp.
From the Reports of the Plato Club. At-
lantic Monthly, Sept. and Oct., 1894,
Vol. 74, pp. 359-368 ; 470-480.
The Daily Life of a Protozoan (vrith C. F.
Hodge). Am. Jour, of Psy., Jan.,
1895, Vol. 6, pp. 524-533.
Education of the Deaf and Dumb. Edu-
cational Beview, Oct., 1896, Vol. 12,
pp. 236-251.
The Field of Pedagogy. Western Reserve
University Bulletin, April, 1897, Vol.
3, pp. 15-21.
R. AKIYAMA: —
School of Science, Tokio, Japan, 1888-
90 ; College of Pharmacy, San Fran-
cisco, Cal,, 1890-91 ; Student in Chem-
istry, University of California, 1891-93 ;
Scholar in Chemistry, Clark Univer-
sity, 1893-94.
ERNEST ALBEE: —
A.B., University of Vermont, 1887 ;
Scholar in Philosophy, Clark Univer-
sity, 1889-90 ; Fellow in Philosophy,
1890-91 ; Fellow Sage School of Phi-
losophy, Cornell University, 1891-92 ;
Instructor in Philosophy, ibid., 1892- ;
Ph.D., Cornell University, 1894 ; Mem-
ber of the Am. Psy. Ass'n.
Author of : —
The Ethical System of Richard Cumber-
land. Philosophical Beview, May and
July, 1895, Vol. 4, pp. 264-290 ; 371-
393.
The Relation of Shaftesbury and Hutche-
son to Utilitarianism. Ibid., Jan.,
1896, Vol. 5, pp. 24-35.
Gay's Ethical System. Ibid., March,
1897, Vol. 6, pp. 132-145.
Hume's Ethical System. Ibid., July,
1897, Vol. 6, pp. 337-355.
ARTHUR ALLIN: —
A.B., Victoria University, Toronto, 1892
(Double Gold Medalist in Classics and
Philosophy) ; University of Heidelberg,
1892 ; University of Breslau, 1892-93 ;
Ph.D., Berlin University, 1895; Hono-
rary Fellow in Philosophy, Clark
University, 1895-96 ; Professor of Psy-
chology and Education, Ohio University,
1896-97 ; Professor of Psychology and
Education, University of Colorado, 1897- ;
459
460
Titles of
Consulting Psychologist, State Industrial
School of Colorado.
Author of ; —
Ueber das Grundprincip der Association,
BerUn, 1895.
The Recognition-Theory of Perception.
Am. Jour, of Psy., Jan., 1896, Vol. 7,
pp. 237-248.
Recognition. Ibid., Jan., 1896, Vol. 7,
pp. 249-273.
The Psychology of Tickling, Laughing,
and the Comic (with G. S. Hall). Ibid.,
Oct., 1897, Vol. 9, pp. 1-41.
Pedagogy in Ohio. Trans. Ohio College
Ass'n, 1897.
ExtrarOrganic Evolution. Science, Feb.
25, 1898, N. S., Vol. 7, pp. 267-269.
Extra-Organic Evolution and Education,
Northwestern Monthly, May and June,
1899, Vol. 9, pp. 400-403; 436-439.
LOUIS "W. AUSTIN: —
A.B., Middlebury College, 1889; Stu-
dent, University of Strassburg, 1889-90
and 1891-93 ; Fellow in Physics, Clark
University, 1890-91 ; Ph.D., University
of Strassburg, 1893 ; Instructor in Physics,
University of Wisconsin, 1893-96 ; Assist-
ant Prof essor, ibid., 1896- ; Member of the
"Wisconsin Academy of Sciences.
Author of : —
Experimentaluntersuchungen iiber die
elastische Langs- und Torsionsnach-
wirkung in Metallen. Annalen der
Fhysik und Chemie, 1893, N. F., Bd.
50, pp. 659-677.
The Effect of Extreme Cold on Magnet-
ism. Physical Beviexo, March-April,
1894, Vol. 1., pp. 381-382.
An Experimental Research on the Lon-
gitudinal and Torsional Elastic Fa-
tigue. Ibid., May-June, 1894, pp.
401-4-25.
On Gravitational Permeability. (With
Charles B. Thvping. ) Ibid. , Nov.-Dec. ,
1897, Vol. 5., pp. 294-300.
Exercises in Physical Measurement.
(With Charles B. Thwing.) Allyn
and Bacon, Boston, 1896. 208 pp.
N. P. AVERY: —
A.B., Amherst College, 1891 ; Principal,
Yates Academy, Chittenango, N. Y., 1891-
95 ; Scholar in Psychology, Clark Uni-
versity, Oct., 1895-Jan., 1896; ad-
mitted to the Massachusetts bar, June,
1896.
FRANK K. BAILEY : —
S. B., Colorado College, 1898 ; Scholar in
Physics, Clark University, 1898-99.
THOMAS P. BAILEY, JR.: —
A.B., South Carolina College, 1887 ;
Principal Wiuyah School, Georgetovyn,
S. C, 1887-88; Tutor in English and
History, University of South Carolina,
1888-89 ; A.M., University of South
Carolina, 1889 ; Secretary, ibid., 1889-91 ;
Ph.D.^ University of South Carolina,
1891 ; Adjunct Professor of Biology,
South Carolina College, 1891-92 ; Fellow
in Psychology, Clark University,
1892-93 ; Lecturer, South Carolina Col-
lege for Women, 1893-94 ; Superinten-
dent of Schools, Marion, S. C, 1894-95;
Assistant Professor of Science and Art of
Teaching, University of California, 1894-
98 ; Associate Professor of Education as
related to Character, ibid. , 1898-.
Author of : —
The Development of Character (Doctor's
Thesis), 1891.
Humanity of the Spiritual Life. Christian
Thought, Oct., 1892.
Ejective Philosophy. Am. Jour, of Psy.,
July, 1893, Vol. 5, pp. 465-471.
Herbart and Character Culture. So. Ed.
Jour. Dec. 1893-Jan. 1894.
Psychology for Teachers. Proc. S. C.
Teachers'' Ass''n, 1893.
The Practice of Medicine and the Practice
of Teaching. Ibid., 1894.
Comparative Child-study Observations.
Handbook III. Soc. for Child-study,
1895.
The Teaching Force — its General Culture.
Proc. Cal. Teachers' Ass'n, 1894.
Child-study for "Naturalists." Pacific
Ed. Jour., April-May, 1895.
Published Papers.
461
The Education of the Human Animal.
Proc. Cal. Teachers' Ass'n, 1896.
Adolescence. Ibid., 1896.
Child-study Notes. Overland Monthly
(School Edition), 1896-97.
Work and Play. Proc. Cal. Teachers'
Ass'n, 1896.
Ethological Outlines. Oakland School Be-
port, 1896-97.
Ethology and Child-study. Northwestern
Monthly, Nov., 1897, Jan., 1898.
Ethology and Child-study. Proc. S. Cal.
Teachers' Ass'n, 1898.
Reformers in Ethology. Bui. No. 13,
Library Univ. of Cal., 1899.
Ethology : Standpoint, Method, Tentative
Results. University Chronicle (Uni-
versity of California), Dec, 1898,
Feb., 1899.
HENR7 ROLFE BAKER: —
A.B., Iowa College, 1882; A.M., 1885;
B.D., Yale University, 1886; Congrega-
tional Ministry, 1887 ; Graduate Student,
Andover Theological Seminary, 1889-90 ;
Hopkins Graduate Student in Philosophy
and Comparative Religion, Harvard Di-
vinity School, 1890-91 ; Student in
Psychology, Clark University, 1894-
95 ; Fellow, 1895-97 ; Honorary
Fellow, 1898-99.
Author of : —
The Position of Myth, Science, and Na-
ture Study in the Philosophy of Edu-
cation.
FRANKLIN W. BARROWS:
A.B., Amherst College, 1885; Instructor
in Sciences, Worcester Academy, 1885-88 ;
A.M., Amherst College, 1888 ; Instructor
in Natural Sciences, Central High School,
Buffalo, N. Y., 1888-Jan. 1894; M.D.,
University of Buffalo, 189.3 ; Fellow in
Physiology, Clark University, Jan.-
June, 1894 ; Instructor in Zoology and
Physiology, Central High School, Buf-
falo, N. Y., 1894 ; Instructor in Histology
and Biology, Medical Department of Uni-
versity of Buffalo, 1894-97 ; Professor,
ibid., 1897-.
GEORGE H. C. L. BAUR : —
Academy of Hohenheim, 1878-79 ; Uni-
versity of Munich, 1879-81 ; University
of Leipzig, 1881-82 ; Ph.D., University
of Munich, 1882 ; Assistant to Professor
C. Kupffer, Munich, 1882-84 ; Assistant
to Professor O. C. Marsh, Yale Univer-
sity, 1884-90 ; Docent in Osteology
and Paleontology, Clark University,
1890-92 ; In charge of the Salisbury Ex-
pedition to the Galapagos Islands, May-
Oct, 1891 ; Assistant Professor, Osteology
and Paleontology, University of Chicago,
1892-95 ; Associate Professor, ibid., 1895-
97.
Died June 25, 1898.
Author of : —
Der Tarsus der Vogel und Dinosaurier.
Eine Morphologische Studie. Inau-
gural-dissertation. Univers. Miinchen.
Leipzig, 1882, Wilh. Engelmann, pp.
1-44, 2 taf. Same in Moiph. Jahrb.,
1883, Bd. 8, pp. 417-456, Taf. XIX.
and XX.
Der Carpus der Paarhufer. Eine Mor-
phogenetische Studie. (Vorl. Mittheil.)
Morph. Jahrb., 1884, Bd. 9, pp. 597-
603.
Dinosaurier und Vogel. Eine Erwieder-
ung an Herrn. Prof. W. Dames in
Berlin. Ibid., 1885, Bd. 10, pp. 446-
454.
Note on the Pelvis in Birds and Dinosaurs.
American Naturalist, Dec, 1884, Vol.
18, pp. 1273-1275.
Bemerkungen iiber das Becken der Vogel
und Dinosaurier. 3Iorph. Jahrb.,
1885, Bd. 10, pp. 613-616.
Zur Morphologic des Tarsus der Sauge-
thiere. Ibid., 1885, Bd. 10, pp. 458-
461.
On the Morphology of the Tarsus in the
Mammals. American Naturalist, Jan.,
1885, Vol. 19, pp. 86-88.
Ueber das Centrale Carpi der Saugethiere.
Morph. Jahrb., 1885, Bd. 10, pp. 455-
457.
On the Centrale Carpi of the Mammals.
American Naturalist, Feb., 1885, Vol.
19, pp. 195-196.
462
Titles of
Das Trapezium der Cameliden. Morph.
Jahrb., 1885, Bd. 10, pp. 117-118.
The Trapezium of tlie Camel idse. Ameri-
can Naturalist, Feb., 1895, Vol. 19, pp.
196-197.
A Second Phalanx in the Third Digit of
a Carinate-Bird's Wing. Science, May
1, 1885, Vol. 5, p. 355.
A Complete Fibula in an Adult Living
Carinate-Bird. Ibid., May 8, 1885,
Vol. 6, p. 375.
On the Morphology of the Carpus and
Tarsus of Vertebrates. American
Naturalist, July, 1885, Vol. 19, pp.
718-720.
Zur Morphologie des Carpus und Tarsus
der Wirbelthiere. Zool. Anz., 1885,
No. 196, pp. 326-329.
Zur Vogel-Dinosaurier-Frage. Ihid., 1885,
No. 200, pp. 441-443.
Nachtragliche Bemerkungen zu : Zur Mor-
phologie des Carpus und Tarsus der
Wirbelthiere {Zool. Anz., 1885, No.
196). Ibid., 1885, No. 202, pp. 486-
488.
Zum Tarsus der Vdgel. Ibid., 1885, No.
202, p. 488.
Note on the Sternal Apparatus in Iguano-
don. Ibid. , 1885, No. 205, pp. 561-562,
Einige Bemerkungen liber die Ossification
der "laugen" Knochen. Ibid., 1885,
No. 206, pp. 580-581.
Bemerkungen iiber den ' ' Astralagus ' ' und
das ' ' Intermedium tarsi ' ' der Sauge-
thiere. Morph. Jahrb., 1886, Bd. 11,
pp. 468-483, Taf. XXVII.
Zur Morphologie des Carpus und Tarsus
der Reptilien. (Vorl. Mittheil.) Zool.
Anz., 1885, No. 208, pp. 631-639.
Ueber das Archipterygium und die Ent-
wicklung des Cheiropterygium aus dem
Ichthyopterygium. (Vorl. Mittheil.)
Ibid., 1885, No. 209, pp. 663-666.
Preliminary Note on the Origin of Limbs.
American Naturalist, Nov. 1885, Vol.
19, p. 1112.
Historische Bemerkungen. Internat.
Monatschr. f. Anat. u. Hist., 1886,
Bd. 3, pp. 3-7.
Der alteste Tarsus ( Archegosaurus) . Zool.
Anz., 1886, No. 216, pp. 104-106.
The Oldest Tarsus (Archegosaurus).
American Naturalist, Feb., 1886, Vol.
20, pp. 173-174.
W. K. Parker's Bemerkungen iiber Ar-
chaeopteryx, 1864, und eine Zusam-
menstellung der hauptsachlichsten
Litteratur iiber diesen Vogel. Zool.
Anz., 1886, No. 216, pp. 106-109.
The Intercentrum of Living Reptilia.
American Naturalist, Feb., 1886, Vol.
20, pp. 174-175.
The Proatlas, Atlas and Axis of the Cro-
codilia. Ibid., March, 1886, Vol. 20,
pp. 288-293, 5 figs.
Die zwei Centralia im Carpus von Sphe-
nodon (Hatteria) und die Wirbel von
Sphenodon und Gecko verticillatus
Laur (G. verus Gray). Zool. Anz.,
1886, No. 219, pp. 188-190.
Herrn Prof. K. Bardeleben's Bemerkungen
iiber "Centetes madagascariensis. "
Ibid., 1886, No. 220, pp. 219-220.
Ueber die Kanale im Humerus der Am-
nioten. Morph. Jahrb., Bd. 12, pp.
299-305.
Bemerkungen iiber Sauropterygia und
Ichthyopterygia. Zool. Anz., 1887,
No. 221, pp. 245-252.
Ueber das Quadratum der Saugethiere.
Sitzungsber. Gesell. Morph. u. Phys-
iol., Miinchen, 1886, pp. 45-57.
On the Quadrate in the Mammalia.
Quart. Jour. Micr. Sci., 1886, Vol. 28,
new ser., pp. 169-180.
Ueber die Morphogenie der Wirbelsaule
der Amnioten. Biol. Centralbl., 1886,
Bd. 6, Nos. 11, 12, pp. 332-342, 353-363.
The Intercentrum in Sphenodon (Hat-
teria). American Naturalist, May,
1886, Vol. 20, pp. 465-466.
Berichtigung. Zool. Anz., 1886, No. 223,
p. 323.
The Ribs of Sphenodon (Hatteria).
American Naturalist, "Noy., 1886, Vol.
20, pp. 979-981.
Ueber die Homologien einiger Schadel-
knochen der Stegocephalen und Rep-
tilien. Anat. Anz., 1886, Jahrg. 1,
pp. 348-350.
Osteologische Notizen iiber Reptilien.
Zool. Anz., 1886, No. 238, pp. 685-690.
Published Papers.
463
Osteologische Notizen iiber Reptilien.
Fortsetzung I. Ihid., 1886, No. 240,
pp. 733-743.
On the Morphogeny of the Carapace of
the Testudinata. American Natural-
ist, Jan., 1887, Vol. 21, p. 89.
Osteologische Notizen liber Reptilien.
Forsetzung II. Zool. Anz., 1887, No.
244, pp. 96-102.
Erwiedermig an Herrn Dr. A. Giinther.
Ibid., 1887, No. 245, pp. 120-121.
Ueber Lepidosiren paradoxa Fitzinger.
Zool. Jahrb., 1887, Bd. 2, pp. 575-583.
Nachtragliche Notiz zu meinen Bemer-
kungen : " Ueber die Homologien
einiger Schadelknochen der Stegoceph-
alen und Reptilien" in No. 13 des
ersten Jahrgangs dieser Zeitschrift.
Anat. Anz., 1887, Jahrg. 2, No. 21,
pp. 657-658.
On the Phylogenetic Arrangement of the
Sauropsida. Jour, of Morph., Sept.,
1887, Vol. 1, pp. 93-104.
Ueber die Abstammung der Amnioten
Wirbelthiere. Biol. Centralbl, 1887,
Bd. 7, No. 16, pp. 481-493.
On the Morphology and Origin of the
Ichthyopterygia. American Natural-
ist, Sept., 1887, Vol. 21, pp. 837-840.
On the Morphology of Ribs. Ibid., Oct.,
1887, Vol. 21, pp. 942-945.
Beitrage zur Morphogenie des Carpus und
Tarsus der Vetebraten. 1 Theil.
Batrachia. Jena, Gustav Fischer,
1888, pp. 1-86, Taf. I.-III.
Ueber den Ursprung der Extremitaten
der Ichthyopterygia. Bericht. uber
die SO. Versam. d. Oberrhein. Geolog.
Vereins, Jan. 16, 1888, 4 pp., 1 taf.
Dermochelys, Dermatochelys oder Sphar-
gis. Zool. Anz., 1888, No. 270, pp.
44-45.
Unusual Dermal Ossifications. Science,
March 23, 1888, Vol. 11, p. 144.
Notes on the American Trionychidse.
American Naturalist, Dec, 1888, Vol.
22, pp. 1121-1122.
The Theory of the Origin of Species by
Natural Selection. Ibid., Dec, 1888,
Vol. 22, p. 1144.
Osteologische Notizen iiber Reptilien.
Fortsetzung III. Zool. Anz., 1888, No.
285, pp. 417-424.
Osteologische Notizen iiber Reptilien.
Fortsetzung IV. Ibid., 1888, No. 291,
pp. 592-597.
Osteologische Notizen iiber Reptilien.
Fortsetzung V. Ibid., 1888, No. 296,
pp. 736-740.
Osteologische Notizen iiber Reptilien,
Fortsetzung VI. Ibid., 1889, No. 298,
pp. 40-47.
Revision meiner Mittheilungen im zool-
ogischen Anzieger, mit Nachtragen.
Ibid., 1889, No. 306, pp. 238-243.
Neue Beitrage zur Morphologie des Carpus
der Saugethiere. Anat. Anz., 1889,
Jahrg. 4, No. 2, pp. 49-51, 4 figs.
The Systematic Position of Meiolania,
Owen. Ann. Mag. Nat. Hist., (6)
Jan., 1889, Vol. 3, pp. 54-62.
On " Aulacochelys," Lydekker, and the
Systematic Position of Anosteira, and
Pseudotrionyx, DoUo. Ibid., 1889, (6)
Vol. 3, pp. 273-276.
On Meiolania and Some Points in the
Osteology of the Testudinata : a Reply
to Mr. G. A. Boulenger. Ibid., 1889,
(6) Vol. 4, pp. 37-45, PI. vi.
Mr. E. T. Newton on Pterosauria. Ibid.,
1889, pp. 171-174.
Die systematische Stellung von Dermo-
chelys Blainv. Biol. Centralbl., 1889,
Bd. 9, Nos, 5 und 6, pp. 149-153, 180-
191.
Nachtragliche Bemerkungen iiber die sys-
tematische Stellung von Dermochelys
Blainv. Ibid. , 1889, Bd, 9, Nos. 20 und
21, pp. 618-619.
Palaeohatteria Credner and the Progano-
sauria. Am. Jour, of Sci., April, 1889,
Vol. 37, pp. 310-313.
Kadaliosaurus prisons Credner, a new
Reptile from the Lower Permian of
Saxony. Ibid., Feb., 1890, pp. 156-
158,
Bemerkungen iiber den Carpus der Pro-
boscidier und der Ungulaten im Alge-
meinen, Morph. Jahrb., 1889, Bd. 15,
Heft 3, pp. 478-482, 1 fig.
On the Morphology of Ribs and the Fate
of the Actinosts of the Median Fins in
464
Titles of
Fishes. Jour, of Morph., Dec, 1889,
Vol. 3, pp. 4G3-4GG, 7 figs.
On the Morphology of the Vertebrate-
Skull. Ibid., 1889, Vol. 3, No. 3, pp.
467-474.
A Review of the Charges against the
Paleontological Department of the
U. S. Geological Survey, and of
the Defence made by Prof. O. C.
Marsh. American Naturalist, March
26, 1890, Vol. 24, pp. 298-304.
Note on Carettochelys, Ramsay. Ibid.,
Nov., 1889, Vol. 23, p. 1017.
The Gigantic Land Tortoises of the Gala-
pagos Islands. Ibid., Dec, 1889, Vol.
23, pp. 1039-1057.
The Relationship of the Genus Dirochelys.
Ibid., Dec, 1889, Vol. 23, pp. 1099-
1100.
The Genera of the Podocnemididse. Ibid.,
May, 1890, Vol. 24, pp. 482-484.
Note on the Genera Hydraspis and Rhine-
mys. Ibid., May, 1890, Vol. 24, pp.
484-485.
The Genera of the Cheloniidae. Ibid.,
May, 1890, Vol. 24, pp. 486-487.
On the Classification of the Testudinata.
Ibid., June, 1890, Vol. 24, pp. 530-
536.
Professor Marsh on Hallopus and Other
Dinosaurs. /6id., June, 1890, Vol. 24,
pp. 569-571.
An Apparently New Species of Chelys.
Ibid., Oct. 1890, Vol. 24, pp. 967-968.
On the Characters and Systematic Posi-
tion of the Large Sea Lizards, Mosa-
sauridse. Science, Nov. 7, 1890, Vol.
16, No. 405, p. 262.
Two New Species of Tortoises from the
South. Ibid., Nov. 7, 1890, Vol. 16,
No. 405, pp. 262-263.
The Problems of Comparative Osteology.
Ibid., 1890, Vol. 16, No. 407, pp. 281-
282.
Das Variieren der Eidechsen-Gattung
Tropiduriis auf den Galapagos Inseln
und Bemerkungen iiber den Ursprung
der Inselgruppe. Biol. Centralbl.,
1890, Bd. 10, Nos. 15 und 16, pp. 475-
483.
The Very Peculiar Tortoise, Carettochelys
Ramsay, from New Guinea. Science,
Apr. 3, 1891, Vol. 17, No. 426, p. 190.
American Box Tortoises. Ibid., Apr. 3,
1891, Vol. 17, No. 426, pp. 190-191.
The Horned Saurians of the Laramie
Formation. Ibid., Apr. 17, 1891, Vol.
17, No. 428, pp. 216-217.
The Lower Jaw of Sphenodon. American
Naturalist, May, 1891, Vol. 25, pp.
489-490.
Notes on the Trionychian Genus Peloche-
lys. Ann. Mag. Nat. Hist., May, 1891,
(6) Vol. 7, pp. 445-446.
Remarks on the Reptiles generally called
Dinosauria. American Naturalist,
May, 1891, Vol. 25, pp. 434-454.
On the Origin of the Galapagos Islands.
Ibid., March and April, 1891, Vol. 25,
pp. 217-229, 307-326.
On the Relations of Carettochelys, Ram-
say. Ibid., July, 1891, Vol. 25, pp.
631-639, Pis. x.-xvi.
On Intercalation of Vertebrae. Jour, of
Morph., Jan., 1891, Vol.4, pp. 331-336.
The Pelvis of the Testudinata, with Notes
on the Evolution of the Pelvis in
General. Ibid. , 1891, Vol. 4, No, 3, pp.
345-359, 13 figs.
Notes on Some Little-known American
Fossil Tortoises. Proc. Acad. Nat.
Sci. Phil., 1891, pp. 411-430.
[Dr. Baur's Trip to the Galapagos
Islands.] American Naturalist, Oct.,
1891, Vol. 25, pp. 902-907.
The Galapagos Islands. Proc. Am. Ant.
Sac, Oct. 21, 1891, pp. 3-8.
Das Variieren der Eidechsen-Gattung
Tropidurus auf den Galapagos-Inseln.
Festschr. z. 70. Geburtstage B. Leuck-
arts. Leipzig, 1892, Wilhelm Engel-
mann, pp. 259-277.
Professor Alexander Agassiz on the Origin
of the Fauna and Flora of the Gala-
pagos Islands. Science, March 25,
1892, Vol. 19, No. 477, p. 176.
Der Carpus der Schildkroten. Anat.
Am., 1892, Jahrg. 7, Nos. 7 und 8,
pp. 206-211, 4 figs.
On the Taxonomy of the Genus Emys,
C. Dum^ril. Proc. Am. Phil. Soc,
1892, Vol. 30, pp. 40-44.
Published Papers.
465
Addition to the Note on the Taxonomy
of the Genus Emys, C. Dum^ril. Ibid.,
1892, Vol. 30, p. 245.
On Some Peculiarities in the Structure of
the Cervical Vertebrte in the Existing
Monotremata. American Naturalist,
Jan., 1892, Vol. 26, p. 72.
[Visit to the Galapagos Islands.] Proc.
Bost. Soc. Nat. Hist., March, 1892,
Vol. 25, p. 317.
The Cei'vical Vertebrae of the Monotre-
mata. Ame7-ican Naturalist, May,
1892, Vol. 26, p. 435.
Bemerkungen iiber verschiedene Arten
von Schildkroten. Zool. Anz., 1892,
No. 389, pp. 155-159.
Ein Besuch der Galapagos-Inseln. Biol.
Centralhl., 1892, Bd. 12, pp. 221-250.
On the Morphology of the Skull in the
Mosasauridae. Jour, of Morph., Oct.,
1892, Vol. 7, pp. 1-22, Pis. i. and ii.
Notes on the Classification and Taxonomy
of the Testudinata. Proc. Am. Phil.
Soc, May 5, 1893, Vol. 31, pp. 210-225.
Notes on the Classification of the Crypto-
dira. American Naturalist, July,
1893, Vol. 27, pp. 672-675.
Two New Species of North American Tes-
tudinata. Ibid., July, 1893, Vol, 27,
pp. 675-677.
Further Notes on American Box-Tortoises,
Ibid., July, 1893, Vol. 27, pp. 677-678.
G. Jager und die Theorie von der Conti-
nuitat des Keimprotoplasmas. Zool.
Anz., 1893, No. 425, p. 300.
Ueber Eippen und ahnliche Gebilde und
deren Nomenclatur. Anat. Am., 1893,
Jahrg. 9, No. 4, pp. 116-120.
The Discovery of Miocene Amphisbsenians,
American Naturalist, Nov., 1893, Vol.
27, pp. 998-999.
The Relationship of the Lacertilian Genus
Anniella Gray, Proc. U. 8. Nat.
Mus., Vol 17, No. 1005, pp. 345-351.
Bemerkungen iiber die Osteologie der
Schlafengegend der hoheren Wirbel-
thiere. Anat. Anz., Dec, 1894, Bd. 10,
No. 10, pp. 315-330.
Ueber den Proatlas einer Schildkrote (Pla-
typeltis spinifer Les.). Ibid., Jan.,
1895, Bd. 10, No. 11, pp. 349-354, 6 figs.
2h
Die Palatingegend der Ichthyosauria.
Ibid., 1895, Bd. 10, No. 14, pp. 456-
459, 1 fig.
The Differentiation of Species on the
Galapagos Islands and the Origin of
the Group. Biol. Lect. M. B. L.
Woods Holl, 1895, pp. 67-78.
Pithecanthropus erectus. Jour. Qeol.,
Feb. and March, 1895, Vol. 3, No. 2,
pp. 237-238.
The Fins of Ichthyosaurus. Ibid., Feb.
and March, 1895, Vol. 3, No. 2, pp.
238-240.
The Experimental Investigation of Evolu-
tion. The Dial, May 1, 1893, p. 278.
Cope on the Temporal Part of the Skull,
and on the Systematic Position of the
Mosasauridae. A Reply. American
Naturalist, Nov., 1895, Vol. 29, pp.
998-1002.
Ueber die Morphologic des Unterkiefers
der Reptilien. Anat. Anz., 1895, Bd.
11, No. 13, pp. 410-415, 4 figs.
Das Gebiss von Sphenodon (Hatteria)
und einige Bemerkungen iiber Prof.
Rud. Burckhardt's Arbeit fiber das
Gebiss der Sauropsiden. Anat. Anz.,
1895, Bd. 11, No. 14, pp. 436-439.
The Paroccipital of the Squamata and the
Affinities of the Mosasauridae Once
More. A Rejoinder to Prof. E. D,
Cope. American Naturalist, Feb., 1896,
Vol. 30, pp. 143-147, PI. iv.
Nachtrag zu meiner Mittheilung liber die
Morphologic des Unterkiefers der Rep-
tilien. Anat. Anz., 1896, Bd. 11, Nos.
18 und 19, p. 569.
Review of Dr. A. E. Ortmann's "Grund-
ztige der marinen Thiergeographie. "
Science, March 6, 1896, Vol. 3, No. 62,
pp. 359-367.
The Stegocephali. A Phylogenetic Study.
Anat. Anz., 1896, Bd. 11, No. 22, pp.
657-673, 8 figs.
Mr. Walter E. Collinge's "Remarks on
the Preopercular Zone and Sensory
Canal of Polypterus." Ibid., 1896, Bd.
11, Nos. 9 und 10, pp. 247-248.
Professor Cope's Criticisms of my Draw-
ings of the Squamosal Region of Cono-
lophus subcristatus Gray (American
466
Titles of
NaUiralist. Feb., 1896, pp. 148-140),
and a Few Remarks about his Draw-
ings of the Same Object from Stein-
daclmer. /6i-rf.,AprU, 18'J6, Vol. UO,
pp. 327-329.
Bemerkungen zu Prof. Dr. O. Bottger's
Beferat iiber : Seeley, H. G. on Theco-
doutosaurus and Palaeosaurus. Zool.
Centralbl., Jahrg. 3, No. 11, 1896,
p. 896.
Der Schadel einer neuen, grossen Schild-
krote (Adelochelys) aus dem zoologis-
chen Museum in Munchen. Anat.
Anz., 1896, Bd. 12, Nos. 12 und 13,
pp. 314-319, 4 figs.
Bemerkungen iiber die Phylogenie der
Schildkroten. Tbid., 1896, Bd. 12, Nos.
24 und 25, pp. 561-570.
On the Morphology of the Skull of the
Pelycosauria and the Origin of Mam-
mals. (With E. C. Case.) 76id., 1897,
Bd. 13, Nos. 4 und 5, pp. 109-120,
3 figs.
Remarks on the Question of Intercalation
of Vertebrae. Zoological Bulletin,
Aug., 1897, Vol. 1, No. 1, pp. 41-
55.
Birds of the Galapagos Archipelago : A
Criticism of Mr. Robert Ridgway's
Paper. Amei-ican Naturalist, Sept.,
1897, Vol. 31, pp. 777-784.
Archegosaurus [Review of 0. Jackels's
"Die Organisation von Archegosau-
rus "]. Ibid., Nov., 1897, Vol. 31, pp.
975-980.
New Observations on the Origin of the
Galapagos Islands, with Remarks on
the Geological Age of the Pacific
Ocean. Ibid., Aug., 1897, Vol. 31, pp.
661-680, and Oct., 1897, pp. 864-896
(incomplete).
HENRY BENNER: —
B.S., State Normal School, West Chester,
Pa., 1885; M.S., ibid, 1887, and Uni-
versity of Michigan, 1889 ; Fellow in
Mathematics, Clark University, 1889-
90 ; Instructor in Mathematics, Prepara-
tory School, Northwestern University,
1890-92 ; Instructor in Mathematics,
Chicago Manual Training School, 1892-.
JOHN A. BERGSTROM : —
A.B., Wesleyan University, Mlddletown,
Conn., 1890 ; Fellow in Psychology,
Clark University, 1891-94; Ph.D.,
Clark University. 1894 : Assistant Pro-
fessor of Psychology and Pedagogy,
Indiana University, 1894-96 ; Associate
Professor of Psychology and Pedagogy,
ibid, 1896-.
Author of : —
Experiments upon Physiological Memory
by Means of the Interference of Asso-
ciations. Am. Jour, of Psy., April,
1893, Vol. 5, pp. 356-369.
An Experimental Study of Some of the
Conditions of Mental Activity. Ibid.,
Jan., 1894, Vol. 6, pp. 247-274.
The Relation of the Interference to the
Practice Effect of an Association.
Ibid., June, 1894, Vol. 6, pp. 433-442.
School Hygiene. (Translation of Dr.
Ludwig Kotelmann's Ueber Schul-
gesundlieitspflege. With Edward Con-
radi.) Bardeen, Syracuse, N. Y. , 1899,
391 pp.
ADOLF BERNHARD: —
A.B., Johns Hopkins University, 1889 ;
Teacher of Mathematics and Science,
National German-American Teachers'
Seminary, Milwaukee, Wis., 1889-91 ;
Fellow in Chemistry, Clark Univer-
sity, 1891-92 ; Fellow in Chemistry,
University of Chicago, 1892-94; Ph.D.,
University of Chicago, 1894 ; Laboratory
Assistant in Chemistry, ibid., 1894-95.
Author of : —
Ueber die Einfiihrung von Acylen in den
Benzoylessigather (Thesis). Chicago,
1894, pp. 4.3.
FRANZ BOAS:—
Ph.D., Kiel, 1881 ; Expedition to Baffin
Land, 1883-84 ; Privatdocent, University
of Berlin, Assistant Royal Ethnographi-
cal Museum of Berlin, 1884-86 ; Expedi-
tion to British Columbia, 1886-87 ; As-
sistant editor of Science, 1887-89; Do-
cent in Anthropology, Clark Univer-
sity, 1889-92 ; Cliief Assistant, Depart-
Published Papers.
467
ment of Anthropology, World's Colum-
bian Exposition, Chicago, 1892-94 ; Ex-
pedition to Alaska, British Columbia, and
California, 1895 ; Assistant Curator,
Department of Anthropology, American
Museum of Natural History, New York,
1896- ; Lecturer on Anthropology, Colum-
bia University, 1896-99 ; Professor of An-
thropology, ibid.^ 1899- ; Member of : the
New York Academy of Sciences, the
American Statistical Association, the
American Psychological Association, the
American Eolk-Lore Society, the Berlin
Anthropological Society, the Berlin Geo-
graphical Society ; Corresponding mem-
ber of the Anthropological Society of
Vienna, the Imperial Society of Friends
of Natural Sciences, Anthropology, and
Ethnology at Moscow, the Roman An-
thropological Society, the Anthropological
Society of Paris, the Anthropological
Society at Washington, the American
Antiquarian and Numismatic Society of
Philadelphia ; Past Vice-President of the
Anthropological Section of the American
Association for the Advancement of
Science ; Associate Editor of the Inter-
nationales ArcMv fur Ethnographie, and
of the American Anthropologist, N. S.
Author of : —
Beitrage zur Erkenntniss der Farbe des
Wassers. Inaugural Dissertation. Kiel,
1881.
Ein Beweis des Talbotschen Satzes. An-
nalen der Physik und Chemie, 1882,
pp. 359-362.
Ueber eine neue Form des Gesetzes der
Unterschiedsschwelle. Pfliiger^s Ar-
cMv, 1881, pp. 493-500.
Ueber die verschiedenen Formen des
Unterschiedsschwellenwerthes. Ibid.,
1882, pp. 214-222.
Ueber die Berechnung der Unterschieds-
schwelle nach der Methode der richti-
gen und falschen Falle. Ibid., 1882,
pp. 84-94.
Die Bestimmung der Unterschiedsemp-
findlichkeit nach der Methode der
iibermerklichen Unterschiede. Ibid.,
1882, pp. 562-566.
Ueber die Grundaufgabe der Psycho-
physik. Ibid., 1882, pp. 566-576.
Ueber den UnterschiedsschweUenwerth
als das Mass der Intensitat psychischer
Vorgange. Philosophische Monats-
hefte, 1882, pp. 367-375.
Ueber die ehemalige Verbreitung der
Eskimos im arktisch-amerikanischen
Archipel. Zeitschrift der Gesellschaft
fur Erkunde, 1883, pp. 118-136.
Die Wohnsitze der Neitchillik Eskimos.
Ibid., 1883, pp. 161-172.
Arctic Exploration and its Object. Pop.
Sci. Mon., May, 1885, Vol. 27, pp.
78-81.
Bemerkungen zur Topographic der Hud-
son Bay. Petermann'' s Mittheilungen,
1885, pp. 424-426.
Baffin Land. Geographische Ergebnisse
einer in den Jahren 1883 und 1884 un-
ternommenen Forschungsreise. Gotha,
1885, 104 pp., 2 maps.
Die Sprache der Bella Coola ludianer.
Verh. Anthrop. Ges., Berlin, 1886, pp.
202-206.
Zur Ethnologic von Britisch Columbien.
PetermaivV s 3Iittheilungen, 1887.
Mittheilungen iiber die Bilqula Indianer.
Originalmittheilungen aus dem K.
Museum fur Volkerkunde, Berlin,
1885, pp. 177-182.
On certain songs and dances of the Kwa-
kiutl Indians. Jour. Am. Folk-Lore,
April-June, 1888, Vol. 1, pp. 49-64.
Meteorologische Beobachtungen im Cum-
berland Sunde. Annalen der Hydro-
graphie, 1888, pp. 241-262.
The Game of Cat's Cradle. Internatio-
nales Arcfiiv fur Ethnographie, 1888.
Chinook Songs. Jour. Amer. Folk-Lore,
1888, pp. 220-226.
Das Fadenspiel. Mittheilungen der An-
thropologischen Gesellschaft, Vienna,
1888, p. 85.
Sagen der Eskimos von Baffin Land.
Verh. der Berliner Anthropologischen
Gesellschaft, 1888, pp. 398-405.
The Study of Geogi-aphy. Science, 1887,
Vol. 9, p. 157.
Arrangement of Ethnological Collections.
Ibid., 1887, Vol. 9, pp. 485, 587, 614.
4G8
Titles of
Ice and Icebergs. Ihid.^ 1887, Vol. 9,
p. 324.
Formation and Dissipation of Seawater
Ice. Ibid., Vol. 10, p. 118.
The Eskimo Tribes. Review of Kink's
Eskimo Tribes. Ibid., Vol. 10, p. 271.
Eskimo and Indian. Ibid.., Vol. 10, p.
273.
The Central Eskimo. Sixth An. Bep.
Bur. Ethn., Washington, 1888, pp.
399-669.
Die Eisverhaltnisse des siidostlichen
Theiles vou Baffin-Land. Beter-
mann^s 3Iittheilungen, 1888, pp. 296-
298, 18 plates.
Eskimo Tales and Songs (Texts). H.
Rink and F. Boas. Jour. Am. Folk-
Lore, Vol. 2, pp. 123-131.
Notes on the Snanaimuq. American
Anthropologist, 1889, pp. 321-328.
Die Ziele der Ethnologic. New York,
1889, 30 pp.
Fourth Report of the Committee on the
Northwestern Tribes of Canada. British
Ass''n Adv. Science, 1888, pp. 1-10.
Fifth Report of the Committee, 1889, pp.
1-96.
Sixth Report, 1890, pp. 1-163.
Seventh Report, 1891, pp. 1-40, 4 tables.
Ninth Report, 1894, pp. 1-16.
Tenth Report, 1895, pp. 1-74, 11 tables.
Eleventh Report, 1896, pp. 1-23.
A Critique of Psycho-Physic Methods.
Science, Vol. 11, p. 119.
The Indians of British Columbia. Bop.
Sci. Mon., March, 1888, Vol. 32, pp.
628-636.
Is Stanley Dead ? Nor. Am. Rev., 1888.
On Alternating Sounds. American An-
thropologist, 1889, pp. 47-53.
On the Census Maps of the United States.
Science, Vol. 12.
Cranium from Yucatan. Am. Antiq. Sac,
1890, pp. 350-357.
The Use of Masks and Head Ornaments
in British Columbia. Intern'' I Arch.
Eth., 1890.
Mixed Races. Science, 1891, Vol. 17, p.
179.
Dissemination of Tales in America. Jour.
Am. Folk-Lore, 1891, pp. 13-30.
Petroglyph in Vancouver Island. Verh.
der. Berliner Ges. fur Anth., 1891, pp.
158-169.
Sagen der Kootenay. Ibid., pp. 159-
172.
Notes on the Chemakum Language. Amer-
ican Anthropologist, 1892, pp. 37-44.
Vocabularies from the North Pacific
Coast. Trans. Am. Bhil. Soc, 1891,
pp. 30.
Chinook Jargon. Science, Vol. 19, p. 474.
The Growth of Children. Ibid., Vol.
19, pp. 256-258, 281-283.
Anthropologic in Amerika. Correspon-
denzblatt deutsch. Anth. Gesellschaft,
1892, pp. 114-116.
Notes on the Chinook Language. Ameri-
can Anthropologist, 1883, pp. 55-63.
The Growth of Children. Science, 1892,
Vol. 26, p. 351.
Vocabulary of the Kwakiutl Language.
Am. Bhil. Soc, 1892, pp. 34-82.
Eskimo Songs and Tales. Jour. Am.
Folk-Lore, 1894, pp. 45-50.
Correlation of Anatomical and Physiolog-
ical Measurements. American Anthro-
pologist, 1894, pp. 313-324.
Linguistische Resultate einer Reise in
Baffin Land. Mittheilungen der An-
thropologischen Gesellschaft, Vienna,
1894, pp. 97-114.
Anthropology of the North American
Indians. Intern^ Cong. Anth. , Chicago,
1894, pp. 37-49.
Classification of Languages of the North
Pacific Coast. Ibid., pp. 339-346.
Omaha Music. Review. Jour. Am.
Folk-Lore, 1894, pp. 169-170.
Remarks on the Theory of Anthropome-
try. International Statistical Con-
gress, Chicago. Quar. Jour. Amer.
Stat. Soc, 1893.
The Half-blood Indian. Bop. Sci. Mon.,
October, 1894.
Human Faculty as Determined by Race.
A. A. A. S., 1894. Reprint, pp. 1-27.
Chinook Texts. Bulletin, Bureau oj
Ethnology, Washington, D.C., 1894,
pp. 1-278.
Salishan Texts. Am. Bhilos. Soc, 1895,
pp. 31-48.
PitblisJied Papers.
469
Notes on the Eskimo of Port Clarence,
Alaska. Jour. Am. Folk-Lore, 1894,
pp. 205-208.
Zur Mythologie der Indianer von Wash-
ington und Oregon. Globus, 1893,
Nos. 10-12.
Dr. W. T. Porter's Investigations on the
Growth of the School Children of St.
Louis. Science, March 1, 1895, pp.
225-230. Correspondenzhlatt der deut-
schen Anth. Ges., 1895.
The Grovyth of First-born Children.
Science, April 12, 1895.
Zur Ethnologie von Britisch Columbien.
Vei'h. d. Ges. fur Erdkunde, Berlin,
May 4, 1895.
Indianische Sagen von der Nordpaciflschen
Kiiste. A. Asher, Berlin, 1895. vi.
+ 364 pp.
The Relations Between Length-breadth
and Length-height Index of the Skull.
Verh. Berliner Ges. fur Anthropologie.
The Growth of United States Naval
Cadets. Science, N. S., Vol. 2, pp.
344-346.
Anthropometry of the Indians of Southern
California. Am. Ass''n for the Adv.
Sci., 1895, pp. 261-269, 9 tables.
Zur Anthropologie der Indianer Nord
Amerikas. Verh. der Berliner Anth.
Ges., 1895, pp. 366-411.
Sprachen Karte von Britisch Columbien.
Petermann^s Mittheilungen, 1896, No,
1, 2 plates.
The Growth of Indian Mythologies.
Jour. Am. Folk-Lore, 1896, pp. 1-12.
Livi. Antropometria Militare. Review.
Science, N. S., Vol. 3, pp. 929 ff.
The Growth of the Head. Ibid., N. S.,
Vol. 4, No. 80.
Songs of the Kwakiutl Indians. Int.
Archiv fur Ethnographic, IX., 1896,
pp. 1-9.
The Limitations of the Comparative
Method of Anthropology. Science,
Dec. 18, 1896, pp. 901-908.
Traditions of the T'sets'a' ut. Jour. Am.
Folk-Lore, Vol. 9, pp. 257-268 ; Vol.
10, pp. 35-48.
The Growth of Children. Science, Vol.
6, pp. 570-573.
The Decorative Art of the Indians of the
North Pacific Coast. Bull. Amer. Mus.
Nat. His., 1897, pp. 123-176.
Eskimo Songs. Jour. Am. Folk-Lore,
1897, pp. 109-115.
Northern Elements in the Mythology of
the Navaho. American Anthropolo-
gist, 1897, pp. 371-376.
Social Organization and Religious Cere-
monials of the Kwakiutl Indians.
Report of the U. S. National Museum
for 1895. Washington, 1897, pp. 311-
736.
Traditions of the Tillamook. Jour. Am.
Folk-Lore, 1898, pp. 23-38, 133-150.
Ehrenreich ; Die Ureinwohner Brasiliens.
Science, N. S., Vol. 6, pp. 880-883.
Introduction to James Teit. Traditions
of the Thompson River Indians of
British Columbia, 1898, pp. 1-18.
The Growth of the School Children of
Toronto. Annual Report of the Com-
missioner of Education, 1896-97.
Washmgton, 1898, Vol. 2, pp. 1541-
1599.
Cathlamet Texts. Nineteenth Annual
Beport of the Bureau of Ethnology,
200 pp.
Nisqa Texts. Ibid., 100 pp.
Facial Paintings of the Indians of North-
ern British Columbia. Memoirs Am.
Mus. Nat. His., Vol. 2, pp. 1-24.
Mythology of the Bella Coola Indians,
Ibid., pp. 25-127.
A Precise Criterion of Species. Science,
Vol. 7, No. 182, pp. 860-861.
Twelfth Report of the Committee of the
British Association for the Advance-
ment of Science on the Northwestern
Tribes of Canada (with Dr. Living-
ston Farrand) . Proc. of the B. A. A. S.,
Bristol Meeting, 1898, pp. 1-61, 12
tables.
Anthropologie in Nord Amerika. Cor-
respbl. der deuts. Ges. f. Anthrop.,
1898.
Mittheilungen aus Amerika. Ibid., 1898,
Jahrg. 29, pp. 121-123.
Some Recent Criticisms of Physical An-
thropology. American Anthropologist,
Jan., 1899, N. S., Vol. 1, pp. 98-106.
470
Titles of
The Cephalic Index. Ibid., July, 1899,
N. S., Vol. 1, pp. 448-461.
EUGENE "W. BOHANNON: —
Graduate, Indiana State Normal School,
1887; Superintendent of Schools, Brown.s-
burg, Ind., 1887-88; A.B., Indiana Uni-
versity, 1890 ; Superintendent of Schools,
Plainfield, Ind., 1889-91 ; Principal, High
School, Pekin, 111., 1891-92; A.M., In-
diana University, 1892 ; Superintendent
of Schools, Rensselaer, Ind., 1892-95;
Scholar in Pedagogy, Clark Univer-
sity. 1895-96 ; Fellow in Psychology,
1896-98 ; Professor of Psychology,
Pedagogy, and Practice, State Normal
School, Mankato, Minn., 1898-.
Author of : —
Peculiar and Exceptional Children. Ped-
agogical Seminary^ Oct., 1896, Vol. 4,
pp. 3-60.
The Only Child in a Family. Ibid.,
April, 1898, Vol. 5, pp. 475-496.
The Undue Emphasis of Method. Ind.
School Jour., Jan., 1899, pp. 1-7.
FREDERICK E. BOLTON: —
Graduate, State Normal School, Milwau-
kee, Wis., 1890; Principal, High School,
Fairchild, Wis., 1890-91 ; B.S., Univer-
sity of Wisconsin, 1893 ; Principal of
Schools, Kaukauna, Wis., 1893-95 ; M.S.,
University of Wisconsin, 1896 ; Univer-
sity of Leipzig, Germany, 1896-97 ; Hon-
orary Fello-w in Psychology, Clark
University, 1897-98; Ph.D., Clark
University, 1898 ; Professor of Psy-
chology and Pedagogy, State Normal
School, Milwaukee, Wis., 1898- ; Mem-
ber, Wisconsin Educational Club ; Past
Vice President, Wisconsin Child Study
Society ; Member, Wisconsin State Teach-
ers' Association.
Author of : —
The Accuracy of Recollection and Obser-
vation. Psychological Review, May,
1896, Vol. 3, pp. 286-295.
The Development of School Curricula in
the United States. Thesis deposited
in Library of University of Wisconsin,
1896, pp. 206.
Apperception in the Study of Geography.
Wis. Jour. Ed., Aug., 1896.
The Importance of Higher Education to
the Teacher. Ibid., Sept., 1890.
The Training of Elementary Teachers in
Germany. Ibid., April, 1896.
Elementary Schools in Germany. Ibid.,
June, 1897.
A Contribution to the Study of Illusions.
Am. Jour, of Psy., Jan., 1898, Vol. 9,
pp. 167-182.
Hydro-Psychoses (Doctorate Disserta-
tion). Ibid., Jan., 1899, Vol. 10, pp.
171-227.
Scientific and Practical Child-study : The
Province and the Limitations of Each.
Wis. Jour. Ed., May, 1899, and Child
Study Monthly, May, 1899, Vol. 5,
pp. 7-24.
The Secondary School System of Ger-
many. The Internat. Ed. Series. D.
Appleton & Co. (In press.)
THADDEUS L. BOLTON: —
A.B., University of Michigan, 1889;
Principal, Public Schools, Vulcan, Mich.,
1889-90; Scholar in Psychology, Clark
University, 1890-91 ; Fellow and As-
sistant, 1891-92 ; Fellow and Demon-
strator, 1892-93 ; Assistant in Ethnol-
ogy, World's Columbian Exposition, 1893 ;
Teacher in Psychology, State Normal
School, Worcester, Mass., 1893-1896;
Ph.D., Clark University, 1895; Pro-
fessor of Psychology and Pedagogy, State
Normal School, San Jos^, Cal., 1896-97;
Professor of Philosophy and Education,
University of Washington, Seattle, Wash.,
1897-98 ; University of Heidelberg, 1898-
99.
Author of : —
Brain Model on a Large Scale, by Dr.
Azoux. Translation. (With H. H.
Donaldson.) Am. Jour, of Psy.,
April, 1891, Vol. 4, pp. 132-141.
The Size of the Several Cranial Nerves in
Man, as indicated by the Areas of
their Cross-sections. (With H. H.
Published Papers.
471
Donaldson. {lUd., Dec, 1891, Vol.
4, pp. 224-229.
The Growth of Memory in School Chil-
dren. Ihid.^ April, 1892, Vol. 4, pp.
362-380.
A Study of the Spinal Cord of a Spring-
halt Horse. Jour, of Nervous and
Mental Diseases, Jan., 1893, N. S.,
Vol. 18, pp. 7-12.
On the Discrimination of Groups of Rapid
Clicks. Am. Jour, of Psy., April,
1893, Vol. 5, pp. 294-310.
Rhythm. Ibid., Jan., 1894, Vol. 6, pp.
145-283.
Asymmetry of Body. Eeport of Cal,
State Teachers'^ Ass'n, June, 1897.
Modern Psychology in its Kelation to
Training of Teachers. Ibid., June,
1897.
What is the New Psychology and what
are its Claims ? Teacher and Student,
San Jos^, Cal, June, 1897, Vol. 4,
pp. 121-126.
Knowledge from the Standpoint of Asso-
ciation. (With E. M. Haskell.) Ed.
Bev., May, 1898, Vol. 15, pp. 474-
499.
Die Zuverlassigkeit einiger Methoden fiir
die Messung des Ermiidungsrgades in
Schulkindern. Psychol. Arbeiten,
herausg. v. E. Kraepelin. (In press.)
OSKAR BOLZA.
Ph.D., University of Gottingen, 1886;
Reader in Mathematics, Johns Hopkins
University, 1888-89 ; Associate in
Mathematics, Clark University, 1889-
92 ; Associate Professor of Mathematics,
University of Chicago, Jan., 1893-Jan.,
1894 ; Professor of Mathematics, ibid.,
Jan., 1894-.
Author of : —
Ueber die Reduction Hyperelliptischer
Integrate auf Elliptische. Sitzungs-
berichte der Freiburger Naturforscheu-
den GeselLschaft, 1885. Dissertation,
Gottingen, 1886. Math. Annalen,
1887, Vol. 28, pp. 447-456.
Darstellung der Invarianten der Binar-
form sechster Ordnung durch die
Nullwerte der zugehorigen Theta-
Functionen. Ibid., 1887, Vol. 30, pp.
478-495.
On Binary Sextics with Linear Transfor-
mations into Themselves. Am. Jour,
of Math., 1888, Vol. 10, pp. 47-70.
On the Consti'uction of Intransitive
Groups. Ibid., 1889, Vol. 2, pp. 185-
214.
On the Theory of Substitution-Groups
and its Applications to Algebraic Equa-
tions. Ibid., 1891, Vol. 13, pp. 1-86.
Ueber Kronecker's Definition der Gruppe
einer Gleichung. Math. Annalen,
1893, Vol. 42, pp. 253-256.
Ueber die linearen Relationen zwischen
den zu verschiedenen singularen Punc-
ten gehorigen Fundamentalsystemen
von Integi'alen der Riemannschen Dif-
ferentialgleichung. Ibid., 1893, Vol.
42, pp. 526-536.
Netto's Theory of Substitutions, trans-
lated by Dr. Cole. Bull, of the N. Y.
Math. Soc, 1893, Vol. 2, pp. 83-106.
On the Transformation of Linear Differ-
ential Equations of the Second Order
with Linear Coefficients. Am. Jour,
of Math., 1893, Vol. 15, pp. 264-273.
On Weierstrass' Systems of Hyperelliptic
Integrals of the First and Second Kind.
Chicago Math. Congress Papers, 1893,
pp. 1-12.
On the First and Second Logarithmic
Derivatives of Hyperelliptic Sigma
Functions. Am. Jour, of 3Iath., 1895,
Vol. 17, pp. 11-36.
Die cubische Involution und die Dreithei-
lung und Transformation dritter Ord-
nung der EUiptischen Fimctionen.
Math. Annalen, 1897, Vol. 50, pp.
68-102.
Zur Reduction hyperelliptischen Integrale
auf elliptische mittels einer Transfor-
mation dritten Grades. Ibid., 1898,
Vol. 50, pp. 314-324.
The Partial Differential Equations for the
Hyperelliptic 6 — and 5 — Functions.
Am. Jour, of Math., April, 1899, Vol.
21, pp. 107-125.
Proof of Brioschi's Recursion Formula for
the Expansion of the Even 5 — Func-
472
Titles of
tions of Two Variables. Am. Jour, of
Math., April, 1899, Vol. 21, pp. 175-
190.
JAMES W. BOYCE: —
B.S , University of Vermont, 1896; Fel-
low in Mathematics, Clark Univer-
sity, 1896-99.
"WILLIAM P. BOYNTON: —
A.B., Dartmoutli College (with honors in
Physics), 1890 ; Professor of Physics and
Chemistry, University of Southern Cali-
fornia, 1890-93 ; A.M., Dartmouth College,
1893 ; Graduate Scholar and Assistant
in Physics, ihid., 1893-94; Scholar in
Physics, Clark University, 1894-95 ;
Fellow, 1895-97 ; Ph.D., Clark Uni-
versity, 1897 ; Instructor in Physics,
University of California, 1897-.
Author of : —
A Quantitative Study of the High-Fre-
quence Induction-Coil. Physical Be-
view, July, 1898, Vol. 7, pp. 35-63 ;
Philosophical Magazine., Sept., 1898,
5th ser.. Vol. 46, pp. 312-338.
JOHN L. BRIDGE: —
B.S., Wesley an University, Middletown,
Conn., 1888 ; Assistant in Chemistry,
ibid., 1889-91 ; Fellow in Chemistry,
Clark University, 1891-92 ; Fellow in
Chemistry, University of Chicago, 1892-
93; Ph.D., Clark University, 1894;
Instructor in Sciences, Connecticut Liter-
ary Institution, 1893-96 ; Instructor in
Sciences, "Waterbury High School, 1896-.
Author of : —
The Ethers of Nitroso-phenol. Am. Chem.
Jour., 1892, Vol. 14, pp. 276-284.
Ueber die Aether des Chinonoximes. Lie-
big'' s Annalen, Vol. 277, pp. 79-105.
The Ethers of Toluchinonoxime and their
bearing on the Space Isomerism of
Nitrogen, (With Wm. Conger Mor-
gan.) Am. Chem. Jour., Nov., 1898,
Vol. 20, pp. 761-776.
CHARLES L. BRISTOL: —
B.S., New York University, 1883;
Teacher of Natural Sciences, Riverview
Academy, Poughkeepsie, N. Y., 188.3-87;
M.S., New York University, 1888; Pro-
fessor of Zoology, State University,
South Dakota, 1888-91 ; Fellow in
Morphology, Clark University, 1891-
92 ; Fellow in Biology, University of
Chicago, 1892-93 ; Associate Professor of
Biology, New York University, 1893-98 ;
Professor of Biology, Ibid., 1898- ; Ph.D.,
University of Chicago, 1894 ; Member of
American Naturalists ; Member of Mor-
phologists' Society ; Member of New York
Zoological Society ; Fellow of New York
Academy of Sciences.
Author of : —
The Metamerism of Nephelis, a contribu-
tion to the morphology of the nervous
system, with a description of Nephelis
Lateralis. Journal of Morphology,
Oct., 1898, Vol. 15, pp. 17-72.
ERNEST NICHOLSON BROWN: —
B.A., Dalhousie University, Halifax,
N.S., 1889; Scholar in Psychology,
Clark University, 1892 ; Assistant in
Ethnology, World's Columbian Exposi-
tion, 1893 ; Principal, Model School,
Levis, Quebec, 1894-95; Principal, Model
School, Lachine, Quebec, 1895- ; Con-
vener of Committee on Child Study of
the Provincial Association of Protestant
Teachers of Quebec, 1897-.
Author of : —
Child Study. Educational Becord of the
Province of Quebec, March, 1898, Vol,
18, pp. 51-63.
The Spelling Problem. Ibid., May-June,
1899, Vol. 19, pp. 73-92.
ELMER B. BRYAN: —
Graduate of Indiana State Normal School,
1889 ; A.B., Indiana University, 1893 ;
Principal of High School, Kokomo, Ind.,
1893-94 ; Teacher of History, Industrial
Training School, Indianapolis, 1894-96;
Professor of Pedagogy, Butler College,
1896-97 ; Assistant Professor of Peda-
gogy, Indiana University, 1897-99; Asso-
ciate Professor, 1899- ; Graduate Student
in Philosophy, Harvard University, Oct.,
Published Papers.
473
1898-Jan. , 1899 ; Scholar in Philosophy,
Clark University, Jan.-Jime, 1899.
Author of: —
School Hygiene. Indiana School Jour-
nal, July, 1899, Vol. 44, pp. 393-396.
School Diseases. Ibid., Aug., 1899, Vol.
44, pp. 465-469.
The Hygiene of Instruction. Ibid., Sept.,
1899, Vol. 44, pp. 533-536.
The Care of the Senses. Ibid., Oct.,
1899, Vol. 44, pp. 593-595.
Child Life. Ibid., Nov., 1899, Vol. 44,
pp. 647-649.
"WILLIAM LOWE BRYAN : —
A.B., Indiana Univereity, 1884; A.M.,
1886 ; Student, University of Berlin, 1886-
87 ; Instructor in Philosophy, Indiana
University, 1885 ; Associate Professor in
Philosophy, ibid., 1885-87 ; Professor in
Philosophy, ibid., 1887 ; Fellow in Psy-
chology, Clark University, Oct., 1891-
Jan., 1893 ; Ph.D., Clark University,
1892 ; Vice-President, Indiana Univer-
sity, 1893-.
Author of : —
Pscyhology at Indiana University. Am.
Jour, of Psy., April, 1890, Vol. 3, pp.
283-284.
On the Development of Voluntary Motor
Ability. Ibid., Nov., 1892, Vol. 5, pp.
125-204.
Auditory and Visual Memory in School
Children. F7-oc. Internal. Ed. Ass''n,
1893.
Suggestions on the Study of Children by
Teachers. Pamphlet, 8 pp.
Child Study : Systematic and Unsystem-
atic. Proc. Dept. of Supt., 1895.
Proc. N. E. A., 1895, pp. 412-418.
On the Methods and Results of Child
Study. Article in Johnson's Encyclo-
pcedia.
Syllabus on Imitation of Teacher by Pupil.
(With U. J. Griffith.) Handb. III. Soc.
for Child Stxidy, May, 1895, Vol 1,
pp. 44-45.
Science and Education. Proc. iV. E. A.,
1895, pp. 161-165.
Report on Work in Child Study in Indi-
ana. Ibid., 1895, pp. 905-906.
Scientific and Non-Scientific Methods of
Child Study. Ibid., 1896, pp. 856-860.
Studies on the Physiology and Psychology
of the Telegraphic Language. (With
Noble Harter.) Psychological Beview,
Jan., 1897, Vol. 4, pp. 27-53.
Hygiene of Motor Development. Proc.
Dept. of Supt., N. E. A., 1897.
Report of Special Committee on the Or-
ganization of a Committee on School
Hygiene. National Council of Educa-
tion, 1897.
Plato the Teacher. Being Selections from
the Apology, Euthydemus, Protagoras,
Symposium, Phaedrus, Republic, and
Phsedo of Plato. Edited with Intro-
duction and Notes. (With Charlotte
Lowe Bryan.) Charles Scribner's
Sons, New York, 1897. xh. + 454 pp.
The Republic of Plato. With Studies
for Teachers (with Charlotte Lowe
Bryan). Charles Scribner's Sons, New
York, 1898. 313 pp.
Studies on the Telegraphic Language.
The Acquisition of a Hierarchy of
Habits. (With Noble Harter.) Psy-
chological Beview, July, 1899. Vol.
6, pp. 345-375.
WARREN G. BULLARD: —
A. B., Brown University, 1892; Instruc-
tor in Mathematics, Free Academy,
Elmira, N.Y., 1892-93; Scholar in
Mathematics, Clark University, 1893-
96 ; Ph.D. , Clark University, 1896 ;
Instructor in Mathematics, University of
Vermont, 1896- ; Member of the Ameri-
can Mathematical Society.
Author of : —
On the General Classification of Plane
Quartic Curves. Math. Beview, Vol.
I., pp. 193-208. (Preprint.)
HERMON C. BUMPUS : —
Ph.B., Brown University, 1884; Instruc-
tor in Zoology, ibid., 1885-86; Professor
in Zoology and Geology, Olivet College,
1886-89 ; Fellow in Animal Morphol-
474
Titles of
ogy, Clark University, 1889-90 ; Ph.D.,
Clark University, 1891 ; Assistant Pro-
fessor, 1890-91, and Associate Professor
of Zoology, Brown University, 1891-92 ;
Professor of Comparative Anatomy, ihid.^
1892- ; Assistant Director, Marine Bio-
logical Laboratory, Woods HoU, Mass.,
1893-95 ; Director Biological Laboratory
of the U. S. Fish Commission, 1898- ;
Secretary of the American Society of Natu-
ralists, 1895-99 ; Vice-President American
Society of Naturalists, 1899-.
Author of : —
Studies in Zoology. Am. Teacher., 1886.
Eeptiles and Batrachians of Rhode Island.
Bandom Notes on Nat. Hist., 1885-86,
Vols. 2, 3.
Reptilia. Stand. Nat. Hist., 1885, Vol. 3.
An Inexpensive Self-registering Anxan-
ometer. Bat. Gaz., 1887, Vol. 12.
The Embryology of the American Lob-
ster. Jour, of Morph., 1891, Vol. 5,
pp. 215-262.
A New Method of using Celloidin for
Serial Section Cutting. Amer. Nat.,
Jan., 1892, Vol. 26, pp. 80-81.
A Laboratory Course in Invertebrate
Zoology. Henry Holt & Co., 1893.
157 pp.
The Median Eye of Adult Crustacea.
Zool. Anz., 1894, p. 447.
Laboratory Teaching of Large Classes in
Zoology. Science, March 8, 1895,
N. S., Vol 1, pp. 260-263.
Instinct and Education in Birds. Ibid.,
August 21, 1896, N. S., Vol. 4, pp. 213-
217.
Report of the Fourteenth Annual Meeting
of the American Society of Naturalists.
Ibid.. Feb. 28, 1896, N. S., Vol. 3, pp.
297-299.
A Review of "The American Lobster, a
Study of its Habits and Development,"
by F. H. Herrick. Ibid., Oct. 9, 1896,
N. S., Vol. 4, pp. 536-537.
A Contribution to the Study of Variation.
Jour, of Morph., Feb. 1897, Vol. 12,
pp. 455-484.
Records of the American Society of
Naturalists for the Meeting of 1896.
A Review of Lloyd Morgan's " Habit and
Instinct." Science, Dec. 17, 1897,
N. S., Vol. 6, pp. 918-920.
Report of the Fifteenth Annual Meeting
of the American Society of Naturalists.
Ibid., Jan. 7, 1898, N. S., Vol. 7, pp.
21-23.
The Result of the Suspension of Natural
Selection as illustrated by the Intro-
duced English Sparrow. Ibid., March
12, 1897, N. S., Vol. 5, pp. 423-424.
A Recent Variety of the Flatfish, and its
Bearing upon the Question of Discon-
tinuous Variation. Ibid.jFeh. 11, 1898,
N. S., Vol. 7, pp. 197-198.
Certain Results from a Study of the Varia-
tion of Littorina. Ibid., Feb. 11, 1898,
N. S., Vol. 7, p. 198.
The Breeding of Animals at Woods HoU
during the Month of March, 1898.
Science, April 8, 1898, N. S., Vol. 7,
pp. 485-487.
The Breeding of Animals at Woods Holl
during the Month of May, 1898. Ibid.,
July 15, 1898, N. S., Vol. 8, pp. 58-61.
The Breeding of Animals at Woods Holl
during the Months of Jime, July, and
August, 1898. Ibid. Dec. 16, 1898,
N. S., Vol. 8, pp. 850-858.
The Variations and Mutations of the
Introduced Sparrow (Passer domesti-
cus). Biological Lectures of the Ma-
rine Biological Laboratory. 1896-97.
Ginn & Co., Boston, 1898, pp. 1-15.
The Variations and Mutations of the In-
troduced Littorina. Zoological Bul-
letin, Feb., 1898, Vol. 1, pp. 247-259.
A Possible Case of Mutation. Jour. Bos-
ton Soc. Med. Sci., Dec. 21, 1897,
Vol. 2, pp. 25-26.
The Work of the Biological Laboratory of
the U. S. Fish Commission at Woods
Holl. Scie7ice, July 22, 1898, N. S.,
Vol. 8, p. 96.
The Identification of Adult Fish that have
been Artificially hatched. Proceed-
ings American Fisheries Society for
1898. American Naturalist, June,
1898, Vol. 32, pp. 407-412.
Professor James Ingraham Peck. (An
Account of his Life and Work.) Sci-
Puhlished Papers.
475
ence, Dec. 2, 1898, N. S., Vol. 8, p.
783.
The Elimination of the Unfit as illustrated
by the Introduced Sparrow (Passer
domesticus') . Biological Lectures of
the Marine Biological Laboratory. (In
press. )
The Return of the Tilefish. Bulletin U. S.
Fish Commission. (In press.)
FREDERIC BURK: —
B.L., University of California, 1883;
Instructor in Literature and History,
California Military Academy, 1889-90 ;
Graduate Student in Literature, Univer-
sity of California, 1890-91 ; Instructor in
Mathematics, Berkeley Gymnasium, 1890-
91 ; Graduate Student in Philosophy, Stan-
ford University, 1891-92, and A. M., 1892 ;
Supervising Principal of Schools, Santa
Rosa, Cal., 1892-96; Fellow in Psy-
chology, Clark University, 1896-97 ;
Honorary Fellow, 1897-98; Ph. D.,
Clark University, 1898; Supt. of
Schools, Santa Barbara, Cal., 1898-99;
President, State Normal School, San
Francisco, 1899- ; President of the Cal.
State Teachers' Ass'n, 1899 ; Chairman of
the Department of Child Study of the N.
E. A., 1899.
Author of : —
Magic Wand. (Alumni Address at Stan-
ford University, 1894, pamphlet).
Report upon the Pedagogical Methods
in the Schools of Santa Rosa (pam-
phlet), 1894.
Modern Changes in Superintendency.
Pacific Ed. Jour., March and April,
1895.
Teasing and Bullying. Pedagogical
Seminary, April, 1897, "Vol. 4, pp.
336-371.
The Training of Teachers; "The Old
Vievsr of Childhood and the NevF."
Atlantic Monthly, Oct., 1897, Vol. 80,
pp. 547-561.
The Graded System vs. Individual Pupils.
Northwestern Monthly, March, 1898,
Vol. 8, pp. 481-484.
Grovyth of Children in Height and "Weight.
Am. Jour, of Psy., April, 1898, Vol.
9, pp. 253-326.
Normal Schools and the Training of
Teachers. Atlantic Monthly, June,
1898, Vol. 81, pp. 769-779.
From Fundamental to Accessory in the
Development of the Nervous System
and of Movements. Pedagogical Sem-
inary, Oct., 1898, Vol. 6, pp. 5-64.
The Evolution of Music and the Pedagogi-
cal Application. Proc. Cal. Teachers''
Ass'n, 1898.
A Curriculum for the Kindergarten from
a Child's Standpoint. Ibid., 1898.
A Study of the Kindergarten Problem.
(With Caroline Frear Burk.) The
Whitaker and Ray Co., San Francisco,
1899. 123 pp.
The Kindergarten Child Physically.
Proc. N. E. A., 1899.
Child Study Application to the Curricula
of the Primary School and Kinder-
garten. Ibid., 1899.
The Influence of Exercise upon Growth.
Am. Phys. Ed. Rev., Dec, 1899, Vol.
4, and Pro. N. E. A., 1899.
WILLIAM H. BURNHAM: —
A.B., Harvard University (with Honors
in Philosophy), 1882 ; Instructor in Witeu-
berg College, 1882-83 ; Instructor in State
Normal School, Potsdam, N. Y., 1883-85;
Fellow, Johns Hopkins University, 1885-
86 ; Ph.D., Johns Hopkins University,
1888; Instructor in Psychology, ibid.,
1888-89; Docent in Pedagogy, Clark
University, 1890-92 ; Instructor,
1892- ; Member of American Psycho-
logical Association.
Author of : —
Memory, Historically and Experimentally
Considered. I. The Older Conceptions
of Memory ; II. Modern Conceptions
of Memory ; III. Paramnesia ; IV. Re-
cent Theories. Am. Jour, of Psy., Nov.,
1888, Feb., May, Aug., 1889, Vol. 2,
pp. 39-90 ; 225-270 ; 431-464 ; 568-622.
The Stage and the Pulpit. Christian
Union, April 19, 1888, Vol. 37, pp.
486-487.
476
Titles of
Training the Memory. Nation, Dec. 13,
1888, Vol. 47, pp. 480-481.
Economy in Intellectual Work. Scribner''s
Magazine, March, 1889, "Vol. 5, pp.
306-314.
Examination and Education. Nineteenth
Century, Am. Suppl., March, 1889,
Vol. 25, pp. 32-35,
Recent Educational Literature. Nation,
Aug. 15, 1889, Vol. 49, pp. 132-133.
The New German School. Pedagogical
Seminary, Jan., 1891, Vol. 1, pp. 1.3-18.
The Study of Adolescence. Ibid., June,
1891, Vol. 1, pp. 174-195.
Observation of Children at the Worcester
Normal School. Ibid., June, 1891,
Vol. 1, pp. 219-223.
Higher Pedagogical Seminaries in Ger-
many. Ibid., Dec. 1891, Vol. 1, pp.
390-408.
Illusions of Memory. Scribher^s Maga-
zine, Feb., 1892, Vol. 11, pp. 185-195.
Outlines of School Hygiene. Pedagogical
Seminary, .June, 1892, Vol. 2, pp. 9-71.
La nuova scuola tedesca. (Translation
of "The New German School" by
Paolo Vecchia). Saggi Pedagogici,
Turin, 1893, pp. 123-129.
A Scheme of Classification for Child-study.
Pedagogical Seminai-y, March, 1893,
Vol. 2, pp. 191-198.
Individual Differences in the Imagination
of Children. Ibid., pp. 204-225.
Some Recent German Literature on Physi-
cal Education. Ibid., pp. 282-298.
Child-study as the Basis of Pedagogy.
Proc. Int. Cong, of Ed., Chicago,
1893, pp. 718-720.
Motor Ability in Children : Development
and Training. Proc. Am. Inst, of
Instruction, Boston, 1894, pp. 127-140.
Un esquema de classificaci6n para el
estudio del nine. (Translation of
"A Scheme of Classification for Child-
study). Boletin de la Institucion libre
de Ensenanza, Madrid, April 30, 1894,
Vol. 18, pp. 107-112.
Bibliographical Notes to Lectures in School
Hygiene. Worcester, Mass., 1897.
11 pp.
Impurities in the Air of Schoolrooms.
Northwestern Monthly, July, 1897,
Vol. 8, pp. 75-80.
Suggestions from the Psychology of Ado-
lescence. School Beview, Dec. 1897,
Vol. 5, pp. 14-27.
Some Aspects of the Teaching Profession.
The Forum, June, 1898, Vol. 25, pp.
481-495.
Bibliography of School Hygiene. Proc.
N. E. A., 1898, pp. 505-523.
El estudio del nifio como base de la peda-
gogia. (Translation of "Child-study
as the Basis of Pedagogy" by Manuel
Valdes Rodriguez). Ensayos sobre
Edncacion Tedrica Practica y Experi-
mental, Tomo Secunda, Habana, 1898,
pp. 159-162.
Mental Hygiene. Johnson's Universal
Cyclopaedia, New Edition, 1C99, Vol.
10.
School Diseases. Ibid.
School Hygiene. Ibid.
The Child in Education. Nation, Jan. 26,
1899, Vol. 68, pp. 72-73.
B. C. BURT: —
A.B., University of Michigan, 1875 ; Pro-
fessor, Indiana State Normal School, 1875-
78 ; A.M., University of Michigan, 1879 ;
Eellow in Philosophy, Johns Hopkins
University, 1881 ; Assistant Professor,
University of Michigan, 1881-87 ; Fellow
by Courtesy, Johns Hopkins University,
1887 ; Docent in Philosophy, Clark
University, 1889-90 ; Ph.D., University
of Michigan, 1894 ; Professsor {ad in-
terim) of Philosophy and Pedagogy,
University of Colorado, 1894-95 ; Agent,
"Northwestern Line" and "Santa F6
Route," Superior, Nebraska, 1896-.
Author of : —
Shakespeare in the Opinion of the 17th
Century. New Englander, 1881.
Watson's Kant and his English Critics.
Unitarian Beview, 1882.
Series of Articles on Greek Philosophy.
Unity, Chicago, 1885-86.
Some Relations between Philosophy and
Literature. Pub. of Phil. Soc, Uni-
versity of Michigan, 1886.
Published Papers.
m
References for Students in English Litera-
ture. Pamphlet, 1887.
Philosophical Works of Professor George
S. Morris. Chronicle, 1889.
A Brief History of Greek Philosophy.
Ginn & Co., Boston, 1889. xiv. + 296
pp.
Translation of Erdmann's History of
Philosophy from Kant to Hegel.
Swan, Sonnenschein & Co., London.
German Philosophy since Hegel. Educa-
tion, April and May, 1890.
Natural Science and the Philosophy of
Nature. Philosophical Review, May,
1892, Vol. 1, pp. 284-291.
History of Modern Philosophy. 2 vols.
McClurg & Co., Chicago, 1892, 368,
321 pp.
Translation of Hegel's Rechts-Pflichten
und Religionslehre.
Translation of Erdmann's Logik und
Metaphysik. Macmillau & Co., New
York.
JOHN CREAN CARDWELL : —
M.D., University of the City of New York,
Medical Department, 1888 ; Assistant in
the Physiological Laboratory, ibid., 1888-
89 ; Fellow in Physiology, Clark Uni-
versity, 1889-91 ; Instructor in Physi-
ology, Harvard Medical School, 1891-93 ;
Lecturer on Physiology, Brooklyn College
of Pharmacy, 1894-98 ; Assistant to the
Chair of Nervous Diseases, Long Island
College Hospital, 1897- ; Chief of Clinic
for Nervous Diseases, Polhemus Clinic,
Brooklyn, N. Y., 1898- ; Demonstrator of
Physiology, Long Island College Hospital,
1899- ; Associate Director of Department
of Physiology, Hoagland Laboratory,
1899-.
ALEXANDER F. CHAMBERLAIN: —
A.B., University of Toronto (with Honors
in Modern Languages and Ethnology),
1886 ; A.M., University of Toronto, 1889 ;
Fellow in Modern Languages, University
College, Toronto, 1887-90 ; Examiner in
French and German, Department of Ed-
ucation, Toronto, 1888-89; Librarian
Canadian Institute, Toronto, 1889-90;
Examiner in German, University of To-
ronto, 1888-91 ; Examiner in Modern
Languages, Trinity University, Toronto,
1890-91 ; Anthropological Researches in
British Columbia, under the auspices of
the British Association for the Advance-
ment of Science, Summer of 1891 ; Secre-
tary Anthropological Section, American
Association for the Advancement of Sci-
ence, 1894 ; Secretary Anthropological
Section, British Association for the Ad-
vancement of Science, 1897 ; Fellow
in Anthropology, Clark University,
1890-92; Ph.D., Clark University,
1892 ; Lecturer in Anthropology,
1892-.
Author of : —
The Relationship of the American Lan-
guages. Proc. Canad. Inst. (Toronto),
3d ser.. Vol. 5, 1886-87, pp. 57-76.
Prehistoric Ethnology. [Brief Abstract.]
Ibid., Vol. 5, 1886-87, p. 144.
The Catawba Language. [Abstract.]
Ibid., Vol. 6, 1887-88, p. 26.
The Eskimo Race and Language. Ibid.,
Vol. 6, 1887-88, pp. 261-337.
A First Contribution to the Bibliography
of the Archaeology of the Dominion of
Canada and Newfoundland. Ann.
Bep. Canad. Inst., 1887-88, pp. 54-
59.
The Catawba Language. Toronto, 1888.
4 pp., 8vo.
The Mississaguas of Scugog. [Abstract.]
Proc. Canad. Inst., 3d ser.. Vol. 7,
1888-89, pp. 2-3.
Deluge Myths of Canadian Indians. [Ab-
stract.] Ibid., pp. 11-12.
Archaeology of Scugog Island. [Abstract.]
Ibid., pp. 14-15.
The Language of the Mississaguas of
Scugog. [Abstract.] Ibid., pp. 213-
215.
The Origin and Development of Gram-
matical Gender. [Abstract.] Ibid.,
pp. 216-217.
A Second Contribution to the Bibliography
of the Archaeology of Canada. Ann.
Bep. Canad. Inst., 1888-89, pp. 102-
118.
478
Titles of
Notes on the Negro Words lagniappe,
buccra, goober. Science, July 13, 1888,
p. 23.
Mississagua Etymology. Ibid., Sept. 14,
p. 132.
The Archaeology of Scugog Island. Port
Perry, 1889. 4 pp., 8vo.
Notes on the History, Customs, and Be-
liefs of the Mississagua Indians. Jour.
Am. Folk-Lore, Vol. 1, 1888, pp. 150-
160.
Tales of the Mississaguas. I. Ibid.., Yo\.
2, pp. 141-147.
A Mohawk Legend of Adam and Eve.
Ibid., Vol.2, pp. 228, 311.
Algonkin Onomatology, with some Com-
parisons with Basque. [Abstract.]
Proc. Am. Ass''n Adv. Sci., Vol. 38,
1889, pp. 351-352.
The Two Brothers : A Mississagua Leg-
end. [Abstract.] Ibid., pp. 352-353.
Words of Indian Origin in the French
Canadian Dialect and Literature. Am.
Notes and Queries (Philadelphia), Vol.
1, 1888, pp. 220-221, 232-233, 258-259,
270-271, 278-279, 293-294, 305-306;
Vol. 2, 1888-89, pp. 2-3, 16-17, 30-31,
52-53, 62-63, 76-77, 87-88, 99-100,
124-125 ; Vol. 4, 1889, pp. 77-78.
Who was "Etowokoam," mentioned in
Spectator, No. 50 ? Ibid., Voh 2, pp.
287-288.
The Etymology of Terrapin. Ibid. , Vol.
3, pp. 210-211.
The Etymology of Tucquan. Ibid., Vol.
3, pp. 262-263 ; Vol. 4, p. 324.
The Derivation of Chicago. Ibid., Vol. 4,
pp. 36, 91-92.
The Names of the Humming Bird. Ibid. ,
Vol. 4, pp. 206-208.
New York Dialect Forms. Ibid. , Vol. 3,
pp. 295-296.
Slav Proverbs. ' Varsity (University of
Toronto), April 7, 1888.
Etymology of Horse-Radish. Am. Notes
and Queries, Vol. 2, 1889, pp. 119-120.
Etymologies of Acadia, gore, undern,
goober, Saginaw, Key West, cockle.
Gal, elfetrich, Manhattan, moonack,
hurrah, chipmunk, plaquemine. Ibid.,
Vol. 1, p. 285 ; Vol. 2, pp. 69, 310, 311 ;
Vol. 3, pp. 8, 9, 10, 103, 107 ; Vol. 4, pp.
34, 164, 155, 214.
Hiawatha in Flemish. Ibid., Vol. 3, pp.
85-87.
Etymology of Fad. Ibid., Vol. 3, pp.
154-155.
Mississagua Place Names. Jour. Am.
Folk-Lore, Vol. 3, 1890, p. 74.
Tales of the Mississaguas. II. Ibid., pp.
149-154.
A Negro Creation Legend. Ibid., p. 302.
The Indians of Canada. [Abstract.]
Trans. Canad. Inst., Vol. 1, 1890-91,
pp. 18-19.
The American Indian in Literature. [Ab-
stract.] Ibid., pp. 33-34.
Mohawk Folk-Lore. Science, Vol. 16,
1890, p. 289.
The Prehistoric Naturalist. Univ. Quart.
Bev. (University of Toronto), Vol. 1,
1890, pp. 179-197.
Dialect Research in Canada. Dialect
Notes, Vol. 1, 1890, pp. 43-56.
Contributions toward a Bibliography of
the Archaeology of the Dominion of
Canada and Newfoundland. III. Ami.
Bep. Canad. Inst., 1890-91, pp. 78-82.
The Algonkian Indians of Baptiste Lake.
Ibid., pp. 83-89.
The Aryan Element in Indian Dialects. I.
Canadian Indian, Vol. 1, 1890-91,
pp. 148-153.
The Thunder-Bird amongst the Algonkins.
American Anthropologist, Vol. 3, 1890,
pp. 51-54.
Note on the Os Incte. Ibid., Vol. 3, p.
104.
Notes on Indian Child Language. Ibid.,
Vol. 3, pp. 237-241.
The Maple amongst the Algonkian Tribes.
Ibid., Vol. 4, 1891, pp. 39-43.
Maple Sugar and the Indians. Ibid.,
Vol. 4, pp. 381-383.
Folk-Etymology in Canadian French.
Modern Language Notes, Vol. 6, 1891,
202-205.
Notes of French Canadian Folk-Lore.
Dominion Illustrated (Montreal), Vol.
4, 1891, pp. 12-13.
Nanibozhu amongst the Otchipw^, Mis-
sissagas, and other Algonkian Tribes.
Published Papers.
479
Jour. Am. Folk-Lore, Vol. 4, 1891,
pp. 193-213.
"Words of Algonkian Origin in the Chinook
Jargon. Science, Vol. 18, 1891, pp.
260-261.
African and American. The Contact of
the NegTO and the Indian. Ibid., Vol.
17, 1891, pp. 85-90.
Classics and Modern Languages in Europe
and America since 1880, or Ten Years
of the New Learning. Toronto, 1891,
60 pp.
Some Points in Linguistic Psychology.
Am. Jour, of Psy., Vol. 6, 1892-93,
pp. 116-119.
Notes on the Canadian French Dialect of
Granby, P. Q. I. Vocabulary. Mod-
em Language Notes, Vol, 7, 1892, pp.
324-327.
Der Wettlauf: Eine Sage der Kftonaqa.
Am Ur-Quell, UI. Bd., 1892, S. 212-
213.
A Mississaga Legend of Nanlbozhii. Jour.
Am. Folk-Lore, Vol. 5, 1892, pp. 291-
292.
The Use of Diminutives in -ing by Some
Writers in Low German Dialects.
Pub. Mod. Lang. Ass''n Am., Vol. 7
1892, pp. 212-217.
The Language of the Mississagas of
Skiigog. A Contribution to the Lin-
guistics of the Algonkian Tribes of
Canada. [Thesis.] Philadelphia, 1892.
84 pp., 8vo.
British Association for the Advancement
of Science. Edinburgh Meeting, 1892.
Eighth Report on the Northwestern
Tribes of Canada. Report on the
Kootenay Indians of Southeastern
British Columbia. (With introduc-
tion by Horatio Hale.) London, 1892.
71 pp., 8vo.
Human Physiognomy and Physical Char-
acteristics in Folk-Lore and Folk-
Speech. Jour. Am. Folk-Lore, Vol.
6, 1893, pp. 13-24.
The Canadian-French Dialect of Granby,
Province of Quebec. II. Phonetics.
Modern Language Notes, Vol. 8, 1893,
31-35.
Einige Wurzeln aus der Sprache der Ki-
tonaqa-Indianer von Britisch-Colum-
bien. Verh. der Berl. Gesellsch. f.
Anthr., Ethn. u. Urgesch., 1893, S.
419-425.
Ueber den Zauber mit menschlichem Blut
und dessen Ceremonial-Gebrauch bei
den Indianern Amerikas. Am Ur-
Quell, IV. Bd., 1893, L, S. 1-3, 11. , S.
34-37, III., S. 64-65.
Sagen vom Ursprung der Fliegen und
Moskiten. Ibid., S. 201-202.
Die Natur und die Naturerscheinungen in
der Mythologie und Volkkunde der In-
dianer Amerikas. I. Der. Regenbo-
gen. Ibid., S. 261-262.
The Physical Education of Woman. By
Prof. Mosso. [Translation.] Peda-
gogical Seminary, Vol. 2, 1892-93, pp.
226-235.
Notes on the Kootenay Indians. I. The
Name. Am. Antiq. and Orient. Jour.,
Vol. 15, 1893, pp. 292-294.
Further Notes on Indian Child Language.
American Anthropologist, Vol. 6, 1893,
pp. 321-322.
Colour-Comparisons in the Low-German
Poets. [Abstract.] Trans. Canad.
Inst., Vol. 3, 1892-93, pp. 43-44.
" Ch'nai-Sny." Nation, Vol. 56, p. 82.
Sulle significazioni laella lingua degli in-
digeni americani detti Kitonaqa (Koo-
tenay) dei termini che denotano gli
stati e le condizioni del corpo e dell'
animo. Saggio di psicologia filologica.
Arch, per V antrop. e la etnol. Firenze,
Vol. 23, 1893, pp. 393-399.
Primitive Woman as Poet. [Abstract.]
Proc. Am. Ass''n Adv. Sci., Vol. 42,
1893, p. 317.
Syllabus of Lectures on the Mythology of
the North American Indians. Report
of President Clark Univ., 1893, pp.
123-125.
Bibliography to accompany a Syllabus of
Lectures on the Mythology of the
North American Indians. Ibid., pp.
141-158.
The Coyote and the Owl (Tales of the
• Kootenay Indians). Mem. Intern.
Cong. Anthrop., Chicago, 1894, pp.
282-284.
480
Titles of
A Kootenay Legend : The Coyote and the
Mountain Spirit. Jour. Am. Folk-
Lore, Vol. 7, 1894, p. 195.
Words Expressive of Cries and Noises in
the Kootenay Language. American
Anthropologist, Vol. 7, 1894, pp. 68-
70.
New Words in the Kootenay Language.
Ibid., pp. 186-192.
Life and Growth of Words in the French
Dialect of Canada. I. Modern Lan-
guage Xotes (Baltimore), Vol. 9, 1894,
pp. 78-87.
Life and Growth of Words in the French
Dialect of Canada. II. Ibid., pp.
135-141.
Ueber die Benennung des Pferdes in den
Sprachen anierikanischer Indianer.
Am Ur- Quell, V. Bd., 1894, S. 5-6.
Notes on the Kootenay Indians. Second
Paper. Linguistic Data. American
Antiq., Vol. 17, 1894, pp. 271-274.
Anthropology in Universities and Colleges.
Pedagogical Seminary, Vol. 3, Oct.,
1894, pp. 48-60.
Primitive Anthropometry and its Folk-
Lore. [Abstract.] Proc. Am. Ass^n
Adv. Sci., Vol. 43, 1894, pp. 348-349.
Incorporation in the Kootenay Language.
[Abstract.] Ibid., pp. 346-348.
Translation into Primitive Languages ;
Errors and Pitfalls ; with illustrations
from Algonkian dialects. [Abstract.]
Ibid., p. 346.
Bayou (Etymology). Nation, Nov. 22,
1894, Vol. 59, p. 381.
La Belle Nivernaise, par Alphonse Daudet,
and Le Chien du Capitaine, par Louis
!]fcnault. Edited, with Lives of the
Authors, Notes, and Vocabulary, by
John Squair, B.A., and A. F. Cham-
berlain, M.A. Toronto, 1890, 6 +
184, and 198 + 132 pp.
Notes on the Kootenay Indians. III.
Mythology and Folk-Lore. Am. An-
tiq. and Orient. Jour., Vol. 17, 1895,
pp. 68-72.
On Words for "Anger" in Certain Lan-
guages. A Study in Linguistic Psy-
chology. Am. Jour, of Psy., Vol. 6,
1894-95, pp. 585-592.
Mutation of Gender in the French Dialect
of Canada. Modern Language Notes,
Vol. 10, pp. 232-236.
The Child and Childhood in Folk-Thought
(The Child in Primitive Culture).
Macmillan's, N. Y,, 1896, x. + 474 pp.,
8vo.
Indian Legends and Beliefs about the
Squirrel and the Chipmunk. Jour.
Am. Folk-Lore, Vol. 9, 1896, pp. 48-
50.
The Poetry of American Aboriginal
Speech. Ibid., pp. 43-47.
Record of American Folk-Lore. Ibid.,
pp. 204-209.
Beitrag zur Pflanzenkunde der Naturvolker
America's. Verh. d. Berl. Ges. f.
Anthr., 1895, S. 551-556.
Childhood. Address before Conference of
Lend-a-Hand Clubs, Lowell, Mass.,
Feb. 1, 1896. Ten Times One Becord
(Boston), Vol. 3, 1896, pp. 7-8.
Anthropology at the Toronto Meeting of
the British Association. Science, N.
S., Vol. 6, 1897, pp. 575-583.
Record of American Folk-Lore. Jour.
Am. Folk-Lore, Vol. 10, 1897, pp.
67-75.
In Memoriam : Horatio Hale. Ibid., pp.
60-66.
The Mythology and Folk-Lore of Inven-
tion. Ibid., pp. 89-100.
Record of American Folk-Lore. Ibid.,
pp. 149-154.
The Unitarian Church as a Social Institu-
tion versus Alcoholism. Boston, 1897,
15 pp.
The Lesson of the " Little Child." North-
icestern Monthly (Lincoln, Neb.), Vol.
7, 1898, pp. 435-439.
Record of American Folk-Lore. Jour.
Am. Folk-Lore, Vol. 10, 1897, pp.
233-239.
Darwin and Lincoln. An Anniversary
Address. Worcester (Mass.) Gazette,
Feb. 8, 1898.
Record of American Folk-Lore. Jour.
Am. Folk-Lore, Vol. 11, 1898, pp.
61-66.
The Kootenays and their Salishan Neigh-
bours. Bep. Brit. Ass'n Adv. Sci.
Published Papers.
481
(Toronto, 1897), Vol. 47, London,
1898, p. 792.
Kootenay Indian Drawings. Ibid., pp.
797-798.
Record of American Folk-Lore. (Jointly
witii I. C. C.) Jour. Am. Folk-Lore,
Vol. 11, 1898, pp. 151-158.
Record of American Folk-Lore. (Jointly
with I. C. C.) Ihid., pp. 293-297.
On the Words for Fear in Certain Lan-
guages. A Study in Linguistic Psy-
chology. Am. Jour. Fsy., Vol. 10,
1898-99, pp. 302-305.
Ethnology of the Aborigines. In British
Association for the Advancement of
Science (Toronto Meeting, 1897).
Handbook of Canada (Toronto, 1897),
pp. 106-126.
American Indian Names of "White Men
and Women. Jour. Am. Folk-Lore,
Vol. 12, 1899, pp. 24-31.
The Child. A Study in Human Evolu-
tion. (Volume of about 400 pages.
In press.)
Art of the Kootenay Indians. (In prep-
aration.)
Mythology of the Kootenays. (In prep-
aration.)
Dictionary of the Kootenay Indian Lan-
guage. I. Kootenay-English. II. Eng-
lish-Kootenay. (In preparation.)
Three Shapers of Childhood's Genius —
Society, Opportunity, Travel. North-
western Monthly, June, 1899, Vol. 9,
pp. 439-443.
Record of American Folk-Lore. (With
I. C. C.) Jour. Am. Folk-Lore, Vol.
12, 1899, pp. 136-143.
Numerous reviews of books and articles in
Journal of American Folk-Lore, He-
view of Historical Publications relat-
ing to Canada, American Jotirnal of
Psychology, Pedagogical Seminary, etc.
"WILL GRANT CHAMBERS: —
Graduate, Pennsylvania State Normal
School, Lock Haven, 1887 ; Instructor in
Mathematics, ibid., 1887-90; A.B., La-
fayette College (Honors in English and
Philosophy), 1894; Instinictor in Mathe-
matics, State Normal School, Indiana, Pa.,
2i
1894-97 ; B.S., State Normal School, Indi-
ana, Pa., 1895 ; M.S., ibid., 1897 ; A.M.,
Lafayette College, 1897 ; Scholar in
Psychology, Clark University, 1897-
98 ; Instructor in Mathematics and Peda-
gogy, State Normal School, Indiana, Pa.,
1899-.
WALTER CHANNING: —
Student, Massachusetts Institute of Tech-
nology, 1867-68 ; M.D., Harvard Univer-
sity, 1872 ; Honorary Scholar, Clark
University, 1889-90 ; Honorary Fel-
low, 1890-92 ; Professor of Mental
Diseases, Tufts College Medical School,
1895- ; Assistant Physician Asylum for In-
sane Criminals, New York, 1873-75 ; First
Assistant Physician, Insane Hospital,
Danvers, Mass. 1876-78 ; Superintendent,
Private Hospital Mental Diseases, Brook-
line, Mass., 1879- ; Chief, Department
Mental Diseases, Boston Dispensary ;
Consulting Physician, Boston Aid Soci-
ety; Member of : American Medical Asso-
ciation, Massachusetts Medical Society,
American Medico-Psychological Society,
American Neurological Society, New
England Psychological Society, Boston
Medical Improvement Society, Boston
Medical Library Association, Corporation
Massachusetts School for Feeble-minded ;
Honorary Member, Association Institu-
tions for Feeble-minded ; Member of :
Council American Association Advance-
ment Physical Education, Boston Society
of Physical Education, Massachusetts
Prison Association, National Conference
of Charities ; Ex-president, Brookline
Education Society, and Boston Medico-
Psychological Society ; Trustee, New Eng-
land Conservatory of Music ; Member,
Brookline School Board.
Author of: —
Case of Helen Miller. Self-mutilation.
Tracheotomy. Am. Jour, of Insanity.
A Case of Feigned Insanity. Boston Med.
and Surg. Jour., 1878, Vol. 98, p. 655.
Buildings for Insane Criminals. Proc. of
Conference of Charities, Chicago,
June, 1879.
482
Titles of
Care of the Insane in Massachusetts.
Boston Med. and Surg. Jour. 1879,
Vol. 101, p. 760.
The Study of Psychological Medicine.
Ibid., 1880, Vol. 102, p. 315.
Note on the Construction of Hospitals for
Insane Paupers. Proc. of Conference
of Charities, Cleveland, June, 1880.
Recent Progress in Insane Asylum Man-
agement. Boston Med. and Surg.
Jour., 1880, Vol. 102, p. 243.
The Treatment of Insanity in its Economic
Aspect. Proc. of Am. Social Sci. Ass^n,
Saratoga, N. Y., Sept. 8, 1880.
The Use of Mechanical Restraint in Insane
Hospitals. Boston Med. and Surg.
Jour., 1880, Vol. 103, p. 173.
Recent Progress in Insane Asylum Man-
agement and Care of the Insane. Ibid.,
1881, Vol. 104, p. 272.
The Care of Insane Criminals. Ibid.,
1881, Vol. 104, p. 172.
Medical Expert Testimony. Ibid., 1881,
Vol. 105, p. 1.
The Mental Status of Guiteau, the Assassin
of President Garfield. Ibid., 1882,
Vol. 106, p. 290.
Recent Progress in Insane Asylum Man-
agement and Construction. Ibid.,
1882, Vol. 106, p. 267.
Recent Progress in the Management of
Lunatic Asylums and Care of the In-
sane. Ibid., 1882, Vol. 107, p. 441.
Non-Restraint in Lunatic Asylums. Ibid.,
1882, Vol. 107, p. 282.
Medical Treatment of the Insane with
Special Reference to Opium. Ibid.,
1883, Vol. 108, p. 86.
Report on Recent Progress in the Con-
struction of Insane Hospitals and
Management of the Insane. Ibid.,
1883, Vol. 109, p. 462.
A Consideration of the Causes of Insanity.
Fifth Ann. Bep. 3Iass. Board of
Health, Lunacy, and Charity, 1884.
Recent Progress in the Construction of
Insane Hospitals and Management of
the Insane. Boston Med. and Surg.
Jour., 1884, Vol. 110, pp. 295 and 321.
Report on the Care of the Insane. Ibid.,
1885, Vol. 112, p. 342.
Temperature of the Insane, Especially in
Acute Mania and Melancholia. Ibid.,
1885, Vol. 113, pp. 1 and 29.
The Connection between Insanity and
Crime. Rep. of the Com. on Biblio-
graphy of Insanity. Pi-oc of Am.
Ass^n of Med. Supts. of Am. InstitUr-
tions for the Insane, Saratoga, N. Y.,
June, 1885.
Recent Progress in the Care of the Insane.
Boston Med. and Surg. Jour. 1886,
Vol. 114, pp. 291 and 318.
Report of a Case of Epilepsy of Forty-five
Years' Duration, with Autopsy. Ibid.,
1886, Vol. 115, p. 4.
Recent Progress in Care of the Insane.
Ibid., 1887, Vol. 116, pp. 351-372.
Progress in the Care of the Insane. Ibid.,
1888, Vol. 118, p. 424.
An International Classification of Mental
Diseases. Am. Jour, of Insanity, Jan.,
1888.
Massachusetts Lunacy Laws. Boston
Med. and Surg. Jour., 1888, Vol. 119,
p. 97.
Lunacy Legislation as Proposed by Dr.
Stephen Smith and Others. Am. Jour.
of Insanity, Jan., 1889.
Physical Training of the Insane. Ibid.,
Oct., 1889.
Physical Education. Boston Med. and
Surg. Jour., 1891, Vol. 125, p. 4.
Physical Education of Children. Pi-oc. of
the An7i. Meeting of the Social Sci.
Ass'n, Sept. 1891.
Evolution of Paranoia. (Rep. of a Case.)
Jour, of Nervous and Mental Diseases,
1892, p. 192.
Some Remarks on the Address Delivered
to the American Medico-Psychological
Association by S. Weir Mitchell, M.D.,
May 16, 1894. Am. Jour, of Insanity,
Oct. 1894.
Tuberculosis in Mental Disease. Boston
Med. and Sxirg. Jour., 1894, Vol. 131,
p. 62.
Physical Training in Childhood. Educa-
tional Revieio, Oct., 1895, Vol. 10, pp.
262-272.
The Importance of Frequent Observations
of Temperature in the Diagnosis of
Published Papers.
483
Chronic Tuberculosis. Boston Med.
and Surg. Jour., Oct. 21, 1895.
A Case of Tumor of tlie Thalamus, with
Remarks on the Mental Symptoms.
Jour, of N'ervous and Mental Diseases,
Aug., 1896.
The Significance of the Palatal Deformities
of Idiots. Jour. Mental Sci., London,
Jan., 1897.
Beginnings of an Education Society.
Educational Bevieio, Nov., 1897.
Characteristics of Insanity. Boston 3Ied.
and Surg. Jour., Dec. 9 and 16, 1897.
The Relation of the Medical Profession to
School Education. Annals of Gynce-
cology and Fcediatry, Jan. 26, 1897.
Physical Training in the Boston Public
Schools. Am. Physical Ed. Review,
June, 1897.
Medical Expert Testimony in the Kelly
Murder Trial. Arn. Jour, of Insanity,
No. 3, 1898, Vol. 54.
The New Massachusetts Board of Insanity.
Charities Beview, Oct., 1898.
OSCAR CHRISMAN: —
Teacher and Principal in Public Schools,
(Owen County, Gosport, Peru, Xenia,
Logansport), Indiana, 1876-85 ; Graduate,
Indiana State Normal School, 1887 ; A.B.,
Indiana University, 1888 ; Principal (Third
Ward), Public School, Houston, Texas,
1888-89 ; Supt. Public Schools, Gonzales,
Texas, 1889-92 ; Fellow in Pedagogy,
Clark University, 1892-94 ; A.M.,
Indiana University, 1893 ; Student in
Philosophy and Pedagogy, University of
Jena, 1894-95 ; Ph.D., University of Jena,
1895; Professor of History of Education
and Child-study, Kansas State Normal
School, 1896- ; Secretary, 1898, and Presi-
dent, 1899, of the Kansas Society for
Child-study.
Author of : —
The Hearing of Children. Pedagogical
Seminary, Dec, 1893, Vol. 2, pp. 397-
441.
Secret Language of Children. Science,
1893, Vol. 22, p. 303 ; 1894, Vol. 23,
p. 18.
The Science of the Child. South Dakota
Educator, Feb., 1894, p. 11.
Vertical Wi-iting. Texas School Jour.,
1894.
Child-study, a New Department of Edu-
cation. Forum, Feb., 1894, Vol. 16,
pp. 728-736.
Contribution to a Symposium on Child-
study. Interstate School Bevieio,
Illinois, June, 1894, p. 225.
One Year with a Little Girl. Educational
Beview, Jan., 1895, Vol. 9, pp. 52-71.
Paidologie, Entwurf zu einer Wissenschaft
des Kindes. Inaugural-Dissertation
der philosophischen Fakultat der Uni-
verstat Jena zur Erlangung der Doktor-
wllrde. Jena, 1896. 96 pp.
Children's Secret Language. Child-study
Monthly, Sept., 1896, Vol. 2, pp. 202-
210.
How a Story Affected a Child. Ibid.,
April, 1897, Vol. 2, pp. 650-661.
The Hearing of School Children. North-
western Monthly, July, 1897, Vol. 8,
pp. 31-35.
Motor Control : Its Place in the Physical
and Psychical Life of the Child. State
Normal 3fonthly, Oct., 1897, Vol. 10,
p. 3.
Child-study in Texas. Child-study
Monthly, Nov., 1897, Vol. 3, p. 287.
(Report of the Child-study Section of
the Texas State Teachers' Association
held at Waco, June 29-July 2, 1897.)
The Secret Language of Children. North-
loestern Monthly, Vol. 8, Oct., 1897,
p. 187 ; June, 1898, p. 649 ; and Jan.,
1899, p. 375.
Exceptionals. State Normal 3Ionthly,
Jan., 1898, Vol. 10, p. 51.
Results of Child-study. Education, Feb.,
1898, Vol. 18, pp. 323-332.
Religious Ideas of a Child. Child-study
Monthly, March, 1898, Vol. 3, pp. 616-
528.
How to use the Library. Western College
Magazine, March, 1898, Vol. 19, p.
502.
Paidology, the Science of the Child. Edu-
cational Beview, March, 1898, Vol. 15,
pp. 269-284.
484
Titles of
The Secret Language of Childhood. Cen-
tury, May, 1898, Vol. 56, pp. 54-58.
Religious Periods of Child-growth. Edxi-
cational lieview, June, 1898, Vol. 16,
pp. 40-48.
Child and Parent. Northwestern Monthly,
Vol. 9, Nov., 1898, p. 135 ; Dec, 1898,
p. 180.
The Pubescent Period. Education, Feb.,
1899, Vol. 19, pp. 342-347.
Opening Remarks as President of the
Kansas Society for Child-study. Child-
study Monthly, Feb., 1899, Vol. 4, p.
451.
Editorial for the Child-study Department.
Northwestern Monthly, Feb., 1899,
Vol. 9, p. 275.
Child and Teacher. Jour, of Pedagogy,
May, 1899, Vol. 12, pp. 112-125.
Courses of Study for Normal Schools.
Arena, July, 1899.
ARTHUR L. CLARK: —
S.B., Worcester Polytechnic Institute,
1894 ; Instructor in Mathematics and
Physics, Bridgeton Academy, Me., 1895-
96 ; Scholar in Physics, Clark Uni-
versity, 1896-97 ; Fellow, 1897-98 ;
Instructor in Science, Worcester Academy,
1898-.
Author of : —
A Method of Determining the Angle of
Lag. Phil. Mag., April, 1896, Vol.
41, pp. 369-372.
On the Specific Inductive Capacity of Cer-
tain Oils. Physical Beview, Feb. , 1898,
Vol. 6, pp. 120-125.
ROBERT CLARK:—
A.B., Amherst College, 1892; Teaching,
1892-97 ; Scholar, Clark University,
1897-99.
THOMAS H. CLARK: —
B.S., Worcester Polytechnic Institute,
1880 ; Assistant Superintendent Pennsyl-
vania Lead Co., 1881-84 ; Student, Johns
Hopkins University, 1884-85 ; Assistant
in Chemistry, Wesleyan University, 1886-
89 ; Fellow in Chemistry, Clark Uni-
versity, 1889-92; Ph.D., Clark Uni-
versity, 1892 ; Assistant in Chemistry,
1892-93 ; instructor in Quantitative
Analysi.s, Tufts College, 1894-95; In-
structor in Chemistry and Physics, Clinton
Liberal Institute, 1895-97 ; Instructor in
Chemistry and Physics, State Normal
School, Plymouth, N. H., 1897- ; Member
Am. Institute of Mining Engineers, and
German Chem. Society.
Author of : —
The Addition-Products of Benzo- and of
Toluquinone. Am. Chem. Jour. , Dec,
1892, Vol. 14, pp. 553-576.
Relative Leichtigkeit der Kohlendioxyd-
abspaltung aus den Silbersalzen der
/3-Chlorcrotonsauren. (With Professor
Arthur Michael.) Jour, far prakt.
Chemie, 1895, N. F., Bd. 52, pp. 326-
329.
CHARLES -W. CLINTON: —
Principal of Public Schools in Wisconsin
and Minnesota ; County Supei'intendent,
Wisconsin ; Visitor to the State Normal
Schools, Wiscon-sin ; Professor, Shattuck
School, Faribault, Minn., 1880-88; Prin-
cipal, St. John's Military Academy, Kan-
sas, 1888-90; Head Master, Peekskill
Military Academy, 1891-93 ; Principal,
Marmaduke (Mo.) Military Academy,
1893-94; Ph.D., Ottawa University, 1895;
Principal, Clinton Classical School, 1895-
97 ; Fellow^ in Psychology, Clark
University, 1897-98 ; Professor of
Mathematics and Latin, Stamford (Ct.)
Preparatory School, 1899.
HERBERT OTIS CLOUQH: —
A.B., Bowdoin College, 1896; Scholar
in Mathematics, Clark University,
1896-97; Assistant in Mathematics,
Bowdoin College, 1897-98 ; Principal
Kennebunkport (Me.) High School, 1898-.
FREDERICK "W. COLEGROVE: —
A.B., Colgate University, 1882; A.M.,
ibid., 1885 ; Student, Hamilton Theological
Seminary, 1882-84 ; Principal, Collegiate
Institute, Marion, N. Y., 1884-89; Pro-
fessor of Latin, Colgate University, 1889-
92 ; President, Ottawa University, Kansas,
Published Papers.
485
1892-96; D.D., University of Rochester,
1893 ; Honorary Fellow in Psychology,
Clark University, 1896-98 ; Ph.D.,
Clark University, 1898 ; Honorary
Fellow in Psychology, Oct. -Dec,
1898 ; Student in Universities of Europe,
1899 ; Professor of Pliilosopliy, Univer-
sity of Wasliington, Seattle, Sept., 1899- ;
Member of the American Philological
Association, and Kansas Historical So-
ciety.
Author of : —
Freedom of Worship. Our Young Peo-
ple, April, 1897.
Individual Memories. Am. Jour, of Psy.,
Jan., 1899, Vol. 10, pp. 228-256.
The Time required for Recognition.
Ibid., pp. 286-292.
Notes on Mental Standards of Length.
Ibid., pp. 292-295.
LEVI L. CONANT: —
A.B., Dartmouth College, 1879; Princi-
pal of High Schools, Minnesota and
Indiana, 1880-83 ; Superintendent of
Schools, Deadwood and Rapid City, So.
Dak., 1883-87 ; A.M., Dartmouth College,
1887 ; Professor of Mathematics, Dakota
School of Mines, 1887-90 ; Scholar in
Mathematics, Clark University, 1890-
91 ; Assistant Professor of Mathematics,
Worcester Polytechnic Institute, 1891-92 ;
A.M. and Ph.D., Syracuse University,
1893 ; Associate Professor of Mathematics,
Worcester Polytechnic Institute, 1892-98 ;
Professor of Mathematics, ibid., 1898-.
Author of : —
Historical Development of Arithmetical
Notation ; and Text Books in Arith-
metic. Pedagogical Seminary, June,
1892, Vol. 2, pp. 149-163.
Primitive Number Systems. Smithsonian
Report, 1892, pp. 583-594.
The Teaching of Mathematics. School
Beview, April, 1893, Vol. 1, pp. 210-
217.
Note on the Translation of Certain Me-
moirs on Infinite Series. Bull, of the
N.Y. Math. Soc, 1894.
The Origin of Numeral Words. Proc. A.
A. A. S., 1894.
English Folk Tales in America. Jour, of
Am. Folk-Lore, April-June, 1895, Vol.
8, pp. 143-144.
The Number Concept. Macmillan and
Company, New York, 1896. vi. +
218 pp.
An Application of the Theory of Substi-
tutions. Am. Math. Soc, Aug., 1898.
ALFRED COOK:—
A.B., Northwestern University, 1877 ;
Ph.D., University of Halle, 1886 ; Fellow
by courtesy, Johns Hopkins University,
1887 ; Superintendent of Schools, Nimonk,
111., 1887-88; Instructor in Philosophy,
Bryn Mawr College, 1888-89; Decent
and Lecturer on History of Philoso-
phy, Clark University, 1889-90 ; Inde-
pendent University Extension Lecturer
on Psychology and on the Philosophy of
History, 1896-.
Author of : —
Ueber die Berkeleysche Philosophic. C.
A. Kaemmerer & Co., Halle, 1886.
48 pp.
Harmony of Natural Law and Free Will,
a Dissertation on the Kantian Philoso-
phy. Bloomington, III., 1888. 16 pp.
L. P. CRAVENS: —
A.B., Carthage College, 1878; A.M.,
ibid., 1879 ; Professor of Mathematics, Mt.
Morris Academy, 1880-84 ; Professor of
Mathematics, Carthage College, 1884-86 ;
Superintendent of Schools, Carthage, 111.,
1886-89 ; Scholar in Mathematics,
Clark University, 1889-90 ; Professor
of Mathematics, State Normal School,
Winona, Minn., 1890-91 ; Student in
Mathematics, University of Halle, 1891-
92 ; Professor of Mathematics, Fort Worth
University, Texas, 1892-94; Student in
Mathematics, University of Chicago, 1894-
95 ; Principal of Academic Department of
Coe College, 1895-96 ; Principal of High
School, Lake City, Minn., 1896-97 ; Super-
intendent of Schools, Lake City, Minn.,
1897-.
486
Titles of
T. R. CROSWELL : —
A.B., Bowdoin College, 1801; rrincipal,
Wilton Academy, 1891-94 ; Student in
Pedagogy, Columbia College, 1894-95 ;
Scholar in Pedagogy, Clark Univer-
sity, 1895-97 ; Teacher in Public
Schools of Chicago, 1897-98 ; Teacher
in Stevens Point (Wis.) Normal School,
1899.
Author of : —
Courses of Study in the Elementary
Schools of the United States. Peda-
gogical Seminary, April, 1897, Vol. 4,
pp. 294-335.
A Study of the Ungraded Schools of
Maine. Maine School Beport, 1897,
Appendix II., pp. 1-15.
Amusements of Worcester School Chil-
dren. Pedagogical Seminary, Sept.,
1899, Vol. 6, pp. 314-371.
HENRY S. CURTIS: —
A.B., Olivet College, 1894; A.B., Tale
University, 1896 (Honors in Philosophy) ;
Fellow in Psychology, Clark Uni-
versity, 1895-97; Ph.D., Clark Uni-
versity, 1898 ; Teacher, N. Y. Public
Schools, 1898-.
Author of : —
Learning without Books. Jour, of Peda-
gogy, Jan., 1898, Vol. 11, pp. 86-90.
Inhibition. Pedagogical Seminary, Oct.,
1898, Vol. 6, pp. 65-113.
Child-study in Connection with the Vaca-
tion Schools. (With G. E. Partridge.)
Report on the Vacation Schools and
Playgrounds, N. Y. City, Boroughs of
Manhattan and the Bronx, 1898, pp.
51-97.
Child-study in Vacation Schools. Educa-
tional Foundatio7is, May, 1899.
Child-study in the Playgrounds. Ibid.,
June, 1899.
Plays and Playgrounds. (In press).
ARTHUR HILL DANIELS: —
B.A., Olivet College, 1887 ; Student, Yale
Divinity School, 1887-90; B.D., Yale
University, 1890 ; Student in Philosophy
and Psychology, Yale University, 1890-
92 ; Fellow in Psychology, Clark
University, 1892-93; Ph.D., Clark
University, 1893 ; Instructor in Phi-
losophy, University of Illinois, 1893-95 ;
Assistant Professor of Philosophy, ibid.,
1895-99; Professor of Philosophy, ibid.,
1899-.
Author of : —
The New Life : A Study of Regeneration.
Am. Jour, of Psy., Oct., 1893, Vol. 6,
pp. 61-106.
The Memory After-image and Attention.
Ibid., Jan., 1895, Vol. 6, pp. 558-564.
SCHUYLER C. DAVISSON: —
A.B., Indiana University, 1890; A.M.,
ibid., 1892; Instructor in Mathematics,
ibid., 1890-93 ; Associate Professor in
Mathematics, ibid., 1893-. Fellow in
Mathematics, Clark University, 1895-
96 ; Student, University of Tiibingen,
Germany, 1898-99.
GEORGE E. DA-WSON: —
A.B., University of Michigan, 1887 ; Pro-
fessor of Greek and English Literature,
Carleton Institute, Farmington, Mo.,
1887-88 ; Student, University of Leipzig,
1888-89 ; Principal, Oil City, Pa., High
School, 1889-91 ; Professor of English and
Literature, State Agricultural College, So.
Dak., 1891-93 ; Instructor in English,
University of Michigan, 1893-95 ; Fellow
in Psychology, Clark University,
1895-97, Ph.D., Clark University,
1897 ; Professor of Psychology, Bible
Normal College, Springfield, Mass., 1897-.
Author of : —
A Stixdy in Youthful Degeneracy. Peda-
gogical Seminary, Dec, 1896, Vol. 4,
pp. 221-258.
Series of Twelve Papers on Child-study.
International Evangel, Sept., 1897-
Sept., 1898.
The Study of Man as Related to Religious
Work. Biblical World, March, 1899.
Interest, the Material of Instruction.
Biblical World, June, 1899.
Suggestions as to the Basis of a Sunday
School Curriculum, Trans. III. Soc.
Published Papers.
487
for Child-Study, Apr.-July, 1899, Vol.
4, pp. 10-17.
Psychic Rudiments and Morality. Am.
Jour, of Psychology. (In press.)
ALFRED T. DE LURY: —
B.A., University of Toronto (with Honors
and Medal in Mathematics), 1890 ; Fellow
in Mathematics, Clark University,
1890-91 ; Mathematical Master, Whet-
ham College, Vancouver, 1891 ; Mathemat-
ical Master, Collegiate Institute, Toronto,
1892 ; Lecturer in Mathematics and Dean
of the Residence, University of Toronto,
1892- ; Member of the American Mathe-
matical Society.
Author of : —
On Certain Deductions from the Theorem
of Dr. Graves. Papers Math, and
Phys. Soc, Toronto Univ., Year
1890-91, pp. 22-30.
Clark University. TJie Varsity, Toronto,
Jan. 27, 1891, Vol. 10, pp. 150-151.
HENRY H. DONALDSON: —
A.B., Yale University, 1879; Sheffield
Scientific School, 1880 ; College of Physi-
cians and Surgeons, N. Y. City, 1881 ;
Fellow, Johns Hopkins University, 1881-
83 ; Ph.D., Johns Hopkins University,
1885 ; Associate in Psychology, ibid.,
1887-88 ; Assistant Professor of Neu-
rology, Clark University, 1889-92 ;
Professor of Neurology, University of
Chicago, 1892-.
Author of : —
On the Detection and Determination of
Arsenic in Organic Matter. (Under
Prof. R. H. Chittenden.) Am. Chem.
Jour., Oct., 1880, Vol. 2, pp. 235-
244.
The Influence of Digitaline on the Work
of the Heart and on the Flow through
the Blood Vessels. (With Dr. L. T.
Stevens.) Jour, of Phys., Jan., 1883,
Vol. 4, pp. 165-197. (See also note in
Vol. 5, p. 45.)
On the Temperature-Sense. Mind, July,
1885, Vol. 10, pp. 399-416.
Motor Sensations of the Skin. (With
Dr. G. Stanley Hall.) Ibid., Oct.,
1885, Vol. 10, pp. 557-572.
On the Relation of Neurology to Psy-
chology. Am. Jour, of Psy., Feb.,
1888, Vol. 1, pp. 210-221.
Anatomical Observations on the Brain
and Several Sense-Organs of the Blind
Deaf-Mute, Laura Dewey Bridgman.
Part I. Ibid., Sept., 1890, Vol. 3, pp.
293-,342. Part II. Dec, 1891, Vol. 4,
pp. 248-294.
Cerebral Localization. Ibid., April, 1891,
Vol. 4, pp. 113-130.
Notes on Models of the Brain. Ibid.,
April, 1891, Vol. 4, pp. 130-131.
The Size of Several Cranial Nerves in
Man as Indicated by the Areas of
their Cross-sections. (With T. L.
Bolton.) Ibid., Dec, 1891, Vol. 4,
pp. 224-229.
The Extent of the Visual Area of the Cor-
tex in Man as deduced from the Study
of Laura Bridgman's Brain. Ibid.,
Aug., 1892, Vol. 4, pp. 503-513.
PreUminary Observations on Some
Changes caused in Nervous Tissues
by Reagents, commonly used to
harden them. Jour, of Morph., Jan.,
1894, Vol. 9, pp. 123-166.
The Education of the Nervous System.
Educational Eeview, Feb., 1895, Vol.
9, pp. 105-121.
The Growth of the Brain. (Contem-
porary Science Series.) Walter Scott,
London. Chas. Scribner's Sons, New
York, 1895. 374 pp.
Central Nervous System. Chapter X.,
Howell's Am. Text-Book of Physiol-
ogy, W. B. Saunders, Philadelphia,
1896, pp. 605-743.
Observations on the Weight and Length
of the Central Nervous System and
of the Legs in Bull-frogs of Different
Sizes. Jour, of Comp. Neurol., Dec,
1898, Vol. 8, pp. 314-335.
D. ELLIS DOUTY: —
B.S., University of Washington, 1892;
Assistant in Physics Laboratory, ibid.,
1895-96 ; Tutor in Physics, ibid., 1896-
488
Titles of
98 ; Scholar in PhysicB, Clark Uni-
versity, 1898-99.
L. WAYLAND DOV/LING : -
Adrian College, 1889-90 ; Principal of
Schools, Clayton, Mich., 1891-92 ; Fel-
low in Mathematics, Clark Univer-
sity, 1892-95; Ph.D., Clark Univer-
sity, 1895 ; Instructor in Mathematics,
University of Wisconsin, 1895-98 ; Assist-
» ant Prof essor of Mathematics, ibid., 1898-;
Member of the American Mathematical
Society ; Member of the Wisconsin Acad-
emy of Sciences, Arts, and Letters.
Author of : —
On the Forms of Plane Quintic Curves.
Mathematical Beview, April, 1897, Vol.
1, pp. 97-119.
FLETCHER B. DRESSLAR: —
Instructor, Vincennes University, 1888 ;
A.B., Indiana University, 1889 ; Princi-
pal, High School, Princeton, Ind., 1889-
90 ; Superintendent of Schools, Princeton,
Ind., 1890-91 ; Scholar in Psychology,
Clark University, 1891-92 ; Instruc-
tor in Psychology, Indiana University,
Sept. -Dec, 1892; Fellow in Psychol-
ogy, Clark University, Jan., 1893-July,
1894 ; Ph.D., Clark University, 1894 ;
Professor of Psychology and Pedagogy,
State Normal School, Los Angeles, Cal.,
1894-97 ; Assistant Professor of the Sci-
ence and Art of Education, University of
California, 1897-.
Author of : —
A Review of the Genus Simotilus. (With
Ernest P. Bicknell.) Proc. Acad, of
Nat. Sci., Philadelphia, 1884.
A Reviev? of the Family Scombrinae
(Illinois). (With Bert Fesler.) Bull,
of U. S. Fish Com., 1887.
Temperance Legislation in Indiana, (Prize
Essay, University of Indiana.) 7n-
diana Strident, March, 1887.
Evils of Modern Immigration. (Prize
Oration, University of Indiana. ) Ibid. ,
Dec, 1889.
Fatigue. Pedagogical Seminary, June,
1892, Vol. 2, pp. 102-106.
A Sketch of Old Schoolhouses. Ibid.,
June, 1892, Vol. 2, pp. 115-125.
Some Influences which affect the Rapid-
ity of Voluntary Movement Am.
Jour, of Psy., Aug., 1892, Vol. 4, pp.
614-527.
On Facial Vision and the Pressure Sense
of the Drum of the Ear. Ibid., April,
1893, Vol. 5, pp. 344-350.
A New Illusion for Touch and an Ex-
planation for the Illusion of Displace-
ment of Certain Cross Lines in Vision.
Ibid., Vol. 6, pp. 275-276.
A New and Simple Method for Comparing
the Perception of Rate of Movement in
the Direct and Indirect Fields of Vision.
Ibid., Vol. 6, p. 312.
Psychology of Touch. Ibid., June, 1894,
Vol. 6, pp. 50-54.
Outline for a Study of Habit-Degenera-
tion. Teachers^ Handbook for Child-
Study. Published by Illinois Society
for Child-Study, May, 1895, Vol. 1,
pp. 21-23.
Preparation for History in the Grades.
Normal Exponent, 1895.
The New Psychology and Its Pedagogical
Significance. Proc. Cal. Teachers^
Ass'n, Dec, 1895.
Experiments in Psychology. Overland
Monthly, Aug., Sept., Nov., Dec,
1896 ; Feb., March, April, June, 1897.
Education in Hawaii. Educational Be-
view, Jan., 1898, Vol. 15, pp. 50-54.
Genetic Psychology. Northtcestern
Monthly, April, 1899, Vol. 9, pp.
355-358.
Guessing, as influenced by Number Pref-
erences. Pop. Sci. Mo., April, 1899,
Vol. 54, pp. 781-786.
FRANK DREW : —
Superintendent of Schools, Genoa, 111.,
1887-89; A.B., Indiana University,
1890; A.M., ibid., 1891; Scholar in
Psychology, Clark University, 1892-
93; Fellow, 1893-95; Ph.D., Clark
University, 1895 ; Instructor in Psy-
chology, Indiana University, 1895-96;
Teacher in State Normal School, Worces-
ter, Mass., 1896-.
Published Papers.
489
Author of •- —
Adenoids in Children. Pedagogical Sem-
inary, March, 1893, Vol. 2, pp. 307-
309.
Love Poems of College Students. Ibid.
Dec. 1893, Vol. 2, pp. 504-505.
Attention : Experimental and Critical.
Am. Jour, of Psy., July, 1896, Vol. 7,
pp. 533-572.
LINDSAY DUNCAN: —
B.S., University of Maine, 1897 ; Scholar
in Mathematics, Clark University,
1897-99 ; Instructor in Mathematics and
Engineering, Union College, Schenectady,
N. Y., 1899-.
ROBERT K. DUNCAN: —
A.B., University of Toronto, 1892 ; Fel-
lo'wr in Chemistry, Clark University,
1892-93; Instructor in Physics and
Chemistry, Auburn, N. Y., High School,
1893-95 ; Instructor in Physics and Chem-
istry, Dr. Julius Sach's Collegiate Insti-
tute, New York, 1895-98; Non-Resident
Student, Columbia University, 1897-98;
Instructor in Physics and Chemistry, The
Hill School, Pottstown, Pa. , 1898-.
WILLIAM FREDERICK DURAND: —
Graduate, U. S. Naval Academy, 1880;
Graduate, Course at Sea, 1882; Assistant
Engineer, U. S. Navy, 1882-87 ; Graduate
Student, Lafayette College, 1883-85 ;
Ph.D., Lafayette College, 1888; Profes-
sor of Mechanics, Michigan State Agri-
cultural College, 1887-91 ; Scholar in
Physics, Clark University, Nov. and
Dec. , 1889 ; Professor of Marine Engi-
neering, Cornell University, 1891-.
Author of : —
A Practical Method of Finding the Opti-
cal Centre of an Objective and its Fo-
cal Length. Am. Mo. Micro. Jour.
Aug., 1885, Vol. 6, p. 141.
The Fundamental Conceptions of Me-
chanics. Privately published, 1890.
The Path of the Point of Contact of the
Teeth of Gear "Wheels. Sci. Am. Sup-
plement, April 26, 1890, Vol. 29.
An Interesting Experiment with the Mi-
croscope. Am. Mo. Micro. Jour.,
June, 1890, Vol. 2, p. 1.36.
The Behavior of Wood under Repeated
and Varying Stress. Trans. Mich.
Eng. Soc, 1891, p. 57.
A New Form of Contour Caliper. Ibid.
1891, p. 62.
Decimal Subdivision by the Eye. Sibley
Jour, of Eng., Jan., 1892, Vol. 6, p.
138.
Study of the Element of a Screw Propel-
ler. Jo^ir. of Am. Soc. of Naval En-
gineers, 1892, Vol. 4, p. 73.
Treatment of Non-Algebraic Curves for
Maxima and Minima by Use of Ordi-
dinates. Ibid. p. 71.
The Influence of Shock on Propeller Effi-
ciency. Ibid. p. 611.
Some Points in the Philosophy of the
Steamship. Cassier^ s Magazine, Nov.,
1892, Vol. 5, p. 35.
Marine Engine Design. Marine Beview,
1892, Vol. 6, Dec. 1, p. 6, and Dec. 8,
p. 12.
Relative Weight of Water and Fire Tube
Boilers. American Shipbuilder, June
20 and 27, 1893.
Planning and Equipment of Modern Ship
and Engine Building Plants. Bep. of
Internal. Eng. Cong., Columbian Ex-
position, Div. of Marine Eng., Vol. 2,
No. 28.
The Limit of Propeller Efficiency as De-
pendent on the Surface Form of the
Propeller. Trans. Am. Soc. of Me-
chanical Engineers, 1893, Vol. 14, p. 65.
The Analysis of Certain Curves arising in
Engineering Investigation. Jour, of
Am. Soc. of Naval Engineers, 1893,
Vol. 5, p. 543.
On the Law of Frictional Resistance.
Trans, of Am. Soc. of Naval Architects
and Marine Engineers, 1893, Vol. 1, p.
210.
A Planimeter for Averaging Radial Ordi-
nates. Sibley Jour, of Eng. 1893,
Vol. 7, p. 64.
Uses of Logarithmic Paper. Engineering
News, Sept. 28, 1893,
New Rules for Approximate Integration.
Ibid., Jan. 18, 1894,
490
Titles of
Mathematical Treatment of Continuous
Functions by Approximate Methods.
Sibley Jour, of Eng., Jan., 1894, Vol.
8, p. 135.
An Approximate Formula for the Wetted
Surface of Ships. (With G. R. McDer-
mott). Trans. Am. Soc. of Naval
Architects and Marine Engineers, 1894,
Vol. 2, p. 297.
Water Tube Boilers for Marine Purposes,
Sibley Jour, of Eng., Feb., 1895, Vol.
9, p. 181.
Electricity for Marine Propulsion. Cas-
sier's Magazine, Jan., 1895, Vol. 8,
p. 143.
Curves showing the Relation between
Equivalent Hollow and Solid Shafts.
Jour, of Am. Soc. of Naval Engineers,
1895, p. 507.
The Number of Longitudinal Intervals in
Ship Computations as Affecting the
Accuracy of Integration for Displace-
ment. Trans. Am. Soc. of Naval
Arcliitects and Marine Engineers, 1895,
Vol. 3, p. 129.
Note on Different Forms of the Entropy
Function. Physical Bevieio, Vol. 4,
p. 343.
Determination of the Current Curve Cor-
responding to any Form of Alternating
Electromotive Force in a Circuit with-
out Iron. Sibley Jour, of Eng., 1897,
p. 182.
Method of Determining a Continuous
Record of the Performance of a Marine
Engine. Jour. Am. Soc. of Naval
Engineers, 1897, p. 1.
Graphical Determination of the Index of
the Power according to which one
quantity varies relative to another.
Jour, of Franklin Inst., March,
1897.
An Experimental Study of the Influence
of Surface on the Performance of Screw
Propellers. Trans. Am. Soc. of Naval
Architects arid Marine Engineers, Vol.
5, p. 107.
Steamship Vibrations and the Balancing
of Marine Engines. Marine Engineer-
ing, June, July, August, 1897.
Resistance and Propulsion of Ships.
J. Wiley & Sons, New York, 1898. vs..
+ 431 pp.
The Approximate Treatment of Differen-
tial Equations. Annals of Math., July,
1898, p. 110.
Entropy and Temperature Entropy Dia-
grams. Jour. Soc. Naval Engineers,
1898, p. 329.
Electrical Propulsion for Torpedo Boats.
Ibid., 1899, p. 53.
FREDERICK EBY: —
A.B., McMaster University, 1895; Gradu-
ate Student, University of Chicago, 1895-
97 ; Assistant Instructor, Morgan Park
Academy, Morgan Park, 111., 1897-98;
Scholar in Pedagogy, Clark Univer-
sity, 1898-99.
Author of : —
Suggestions for Work which can be done
by Teachers. 43d. Anriual Report
State Supt. of Ed., Albany, N. Y.,
1897, Vol. 2, pp. 968-972.
Study of the Use of Secret Languages
(Syllabus). Ibid., pp. 972-973.
Preliminary Study of Child-^^sthetics
(Syllabus). Ibid., p. 976.
Educational Value of Manual Construc-
tive Work. Education, April, 1898,
Vol. 18, pp. 491-495.
Translation of Pestalozzi's "Meine Nach-
forschungen." (With Dr. Julia E.
Bulkley.) (In press.)
THOMAS "W. EDMONDSON: —
B.A., London, Eng., 1888 (first in Honors
and Senior Exhibitioner at Matriculation,
June, 1886) ; Akroyd Scholar, 1888-90 ;
Senior Mathematical Scholar, Pembroke
College, Cambridge University, Eng.,
1888-91 ; B.A., Cambridge University
(18th Wrangler in Mathematical Tripos),
1891 ; Graduate Student in Chemistry,
Physics, and Botany, ibid., 1891 ; Assist-
ant Tutor in Mathematics and Physics,
University Corr. College, Cambridge, Eng.,
1889-93 ; First Class in Intermediate
Science Examination, London, 1893 ;
Fello-w in Physics, Clark University,
1894-96; Ph.D., Clark University,
Published Peepers.
491
1896 ; Assistant Professor of Physics,
New York University, 1896- ; Member of
the American Mathematical Society, and
American Physical Society.
Author of : —
Key to Briggs and Bryan's Coordinate
Geometry. W. B. Clive & Co.,
London, New York, and Sydney, 1891.
192 pp.
"Worked Examples in Coordinate Geome-
try. W. B. Clive & Co., London, New
York, and Sydney, 1891 ; 18 Exam.
Papers + 62 pp.
Mensuration and Spherical Geometry.
(In collaboration with W. Briggs,
M.A., LL.B., etc.) W. B. Clive &
Co., London, New York, and Sydney,
1893. vi. +112, ii. +48 pp.
Key to Briggs and Bryan's Elementary
Text-book of Mechanics. (In collab-
oration with Bion Eeynolds, M.A.)
W. B. Clive & Co. , London, New York,
and Sydney, 1895. viii. + 172 pp.
On the Disruptive Discharge in Air and
Liquid Dielectrics. Physical Beview,
Feb., 1898, Vol. 6, pp. 65-97.
CHARLES L. EDWARDS: —
B.S., Lombard University, 1884; B.S.,
Indiana University, 1886 ; A.M., ibid.,
1887 ; Student, Johns Hopkins University,
1887-89; Ph.D., University of Leipzig,
1890 ; Fellow in Morphology, Clark
University, 1890-91 ; Honorary Fel-
low, Clark University, 1891-92;
Assistant Professor of Biology, University
of Texas, 1892-93 ; Adjunct Professor of
Biology, ibid.i 1893-94; Professor of
Biology, University of Cincinnati, 1894- ;
Member of the American Society of Natu-
ralists ; Morphological Society ; President
of the American Folk-Lore Society, 1899 ;
Socio Corresponsal, La Sociedad de Geo-
grafia y Estadistica, Mexico ; Socio
Honorario, La Sociedad Mexicana de
Historia Natural ; Socio Honorario, La
Sociedad Antonio Alzate.
Author of : —
The Relation of the Pectoral Muscles in
Birds to the Power of Flight. Ameri-
can Naturalist, Jan., 1886, Vol. 20,
pp. 25-29.
A Review of the American Species of the
Tetraodontidse. (With President David
S. Jordan.) Proc. of U. S. Nat. Mus.,
1886, p. 232.
The Influence of Warmth upon the Irrita-
bility of Frog's Muscle and Nerve.
Studies from Biol. Lab., Johns Hop-
kins University, July, 1887.
Winter Roosting Colonies of Crows. Am.
Jour, of Psy., May, 1888, Vol. 1, pp.
436-459.
Notes on the Embryology of Miilleria
Agassizii Sel. , a Holothurian common
at Green Turtle Bay, Bahamas. Johns
Hopkins University Circular, 1889,
Vol. 8, p. 37.
Folk-Lore of the Bahama Negroes. Am.
Jour, of Psy., Aug., 1889, Vol. 2, pp.
619-542.
Beschreibung einiger neuen Copepoden
und eines neuen copepodenahnlichen
Krebses, Leuckertella paradoxa.
Archiv f. Naturrjeschichte, Berlin,
1891, Jahrg. 67, Bd. 1, 36 pp.
Some Tales from Bahama Folk-Lore.
Jour, of Am. Folk-Lore, 1891, Vol. 4,
pp. 47-54.
Some Tales from Bahama Folk-Lore.
Fairy Tales: Ibid., pp. 247-252.
Bahama Songs and Stories. (Vol. 3 of
Memoirs of the Am. Folk-Lore Society.)
Houghton, Mifflin & Co., Boston, 1895.
Ill pp.
Notes on the Biology of Phrynosoma Cor-
nutum Harlan. Zool. Atizeiger, 1896.
STAFFORD C. EDWARDS: —
Classical Graduate, Oneonta, N. Y.,
Normal, 1891 ; A.B., Brown University,
1895; A.M., Philosophy and Pedagogy,
ibid., 1896 ; Student Teacher of History and
English, High School, Providence, R. I.,
1895-96; Principal of Greenport, N. Y.,
Union School, 1896-97 ; Scholar in
Pedagogy, Clark University, Oct.,
1897-March, 1898 ; Teacher of Mathe-
matics, Jamaica, N. Y., Normal School,
March-June, 1898 ; Principal Union School,
Schuylerville, N. Y., 1898-.
492
Titles of
ALEXANDER CASTVELL ELLIS: —
Head Master, Classical High School,
Chapel Hill, N. C, 1891-92; A.B.,
University of North Carolina, 1894 ;
Scholar in Pedagogy, Clark Univer-
sity, 1894-95 ; Fellow in Psychology,
1895-97; Ph.D., Clark University,
1897 ; Adjunct Professor of Pedagogy,
University of Texas, 1897- ; Member of
American Association for the Advance-
ment of Physical Education ; Member
of Illinois Child-Study Society ; Fellow,
Texas Academy of Science.
Author of : —
Sunday School Work and Bible Study in
the Light of Modern Pedagogy. Peda-
gogical Seminary, June, 1896, Vol. 3,
pp. 363-412.
A Study of Dolls. (With G. Stanley Hall. )
Ihid., Dec, 1896, Vol. 4, pp. 129-175.
Suggestions for a Philosophy of Education.
Ihid., Oct., 1897, Vol. 5, pp. 159-201.
Play in Education. Northxoestern Monthly,
Nov., 1898 ; and Bep. of Ad. and Proc.
Texas State Teachers'' Ass^n, 1898.
Reading and Literature in the Schools.
Bep. of Ad. and Proc. Texas State
Teachers' Ass'ti, 18'98.
The Science of Education in the Univer-
sity of Texas, and Some of Its Prob-
lems. University Becord, University
of Texas, Vol. 1, No. 2.
BENJAMIN F. ELLIS: —
A.B., Dartmouth College, 1889 ; Instruc-
tor in Physics and Mathematics, High
School, Peoria, 111., 1889-92 ; Scholar in
Physics, Clark University, 1892-93 ;
Instructor, High School, Peoria, 111.,
189:3-.
PERCY NORTON EVANS: —
B.A.Sc, McGill University, Montreal,
1890 ; Assistant in Chemistry, ibid., 1890-
91 ; Student, University of Leipzig (McGill
Exhibition of 1851 Science Scholar), 1891-
98 ; Ph.D., University of Leipzig, 1893 ;
Honorary Fello-w in Chemistry, Clark
University, 1894 ; Assistant in Chemis-
try to Professor Atwater, Wesleyan Uni-
versity, 1894-95 ; Instructor in Chemistry,
Purdue University, 1895-96 ; Associate
Professor of Chemistry, ibid., 1896- ;
Member of the Indiana Academy of
Science.
Author of : —
Condensation von /3-Diketonen mit Harn-
stoff und Thioharnstoff. Jour, fur
praktische Chemie, Vol. 46, p. 352.
Condensationsprodukte der /3-Diketone
mit Harnstoff, Guanidin, und Thioharn-
stoff. Ibid., Vol. 48, pp. 489-517.
Food Adulteration. Purdue University
Monographs, 1896. 17 pp.
An Introductory Course in Quantitative
Analysis. Ginn & Co., Boston, 1897.
iv. + 83 pp.
Note on Some Combustion Products of
Natural Gas. Proc. Ind. Acad, of
Science, 1897, pp. 133-134.
Note on the Iodine Number of Linseed
Oil. Ibid., 1898, pp. 160-163.
H. L. EVERETT: —
A.B., Brown University, 1886; A.M.,
Harvard University, 1889 ; Student, Berlin
University, 1889-90; Professor, Utah
Agricultural College, 1890-92 ; Scholar
in Psychology, Clark University,
1896-97 ; Honorary Fellov^ in Psy-
chology, 1897-98 ; Instructor, Macken-
zie College, S. Paulo, Brazil, 1898-.
ALBERT C. EYCLESHYMER : —
Assistant in Animal Morphology, Uni-
versity of Michigan, 1888-89 ; Assistant
in Botany, ibid., 1889-90 ; Chief Assist-
ant, Allis Lake Laboratory, 1890-91 ;
B.S., University of Michigan, 1891 ;
Fellow in Morphology, Clark Uni-
versity, 1891-92 ; Fellow in Biology,
University of Chicago, 1892-93 ; Assistant
in Anatomy and Histology, ibid., 189.3-
95; Ph.D., University of Chicago, 1895;
Tutor in Anatomy and Histology, ibid.,
1895-.
Author of : —
Celloidin Imbedding in Plant Histology.
Botanical Gazette, Vol. 15, pp. 272-
295.
Published Papers.
493
Notes on Celloidin Technique. American
Naturalist, Vol. 26, pp. 354-358.
Club-root (Plasmodiophora brassicae
Wor.) in the United States. Journal
of Mycology, Vol. 7, pp. 79-90.
Paraphysis and Epiphysis in Amblystoma.
Anatomischer Anzeiger, April 7, 1892,
Vol. 7, pp. 215-217.
The Cleavage of the Amphibian Ovum.
(With E. O. Jordan.) Ibid. Sept. 15,
1892, Vol. 7, pp. 622-624.
The Development of the Optic Vesicles in
Amphibia. Jour, of Morph., April,
1893, Vol. 8, pp. 189-194 ; Figs. 1-6.
On the Cleavage of Amphibian Ova.
(With E. 0. Jordan.) Ibiil, Sept.,
1894, Vol. 9, pp. 407-416 ; PI. xxvi.
The Early Development of Amblystoma
with Observations on some other
Vertebrates. Ibid., Feb., 1895, Vol.
10, pp. 343-418 ; Pis. xviii-xxii.
FREDERICK C. FERRY : —
A.B., Williams College, 1891; Instructor
in Latin and Mathematics, ibid., 1891-
94; A.M., ibid., 1894 ; Graduate Student
in Mathematics, Harvard University,
1894-95; A.M., ibid., 1895; Fellow in
Mathematics, Clark University, 1895-
98; Ph.D., Clark University, 1898;
Assistant Professor of Mathematics, Wil-
liams College, 1899-.
Author of : —
Geometry on the Cubic Scroll of the First
Kind. Archiv for Mathematik og Na-
turvidenskab, B. xxi, Nr, 2.
DANIEL FOLKMAR: —
A.B., Western College, 1884 ; A.M., ibid.,
1888 ; Student, Harvard Divinity School,
1888-89 ; Fellow in Psychology, Clark
University, 1889-90 ; Professor of Po-
litical Science and Psychology, Indiana
Normal University, 1890-91 ; President
and Professor of Social Science, ibid.,
1891-92 ; Professor of Social Science,
Western Michigan College, 1892-93 ; Presi-
dent, ibid., 1893 ; Lecturer in Sociology,
University of Chicago, 1893-95 ; Professor
of Psychology and Pedagogy, State Nor-
mal School, Milwaukee, Wis., 1895-98 ;
Student, University of Paris, 1898-99;
Professor of Anthropology, University
Nouvelle, Brussels, Belgium, 1898 ; Doc-
teur fes sciences sociales, ibid., June, 1899 ;
Fellow of the Royal Statistical Society,
London ; Member of : Anthropologische
Gesellschaft in Wien, Anthropological So-
ciety of Washington, American Associa-
tion for the Advancement of Science,
American Academy of Political and Social
Science, American Statistical Association,
American Institute of Sociology, Wisconsin
Academy of Sciences, Arts, and Letters.
Author of : —
Instruction in Sociology in Institutions of
Learning. Reprint from Proc. of Nat.
Conf. of Charities and Correction,
Boston, 1894. 19 pp. Also reprinted
as Chapter XXVII of the Report of
U. S. Com. of Ed. for 1894-95, Vol. 2,
pp. 1211-1221.
A Sociological Ideal View of Normal
Schools. Proc. of Inter. Cong, of Ed.
of the World's Columbian Exposition,
1893, pp. 422-428. Published by Am,
Ed. Ass'n, New York, 1893.
New Views in Social Science, etc. The
Interrogator, Feb. -June, 1893.
The Ideal in Professional Training." Edu-
cation, April, 1896.
The Duration of School Attendance in
Chicago and Milwaukee. Proc. Wis-
consin Academy of Sciences, Arts, and
Letters, 1897, Vol. 12, pp. 255-305.
Anthropology, not Sociology, as an ade-
quate Philosophy of Human Life.
Proc. A. A. A. 8., 1898.
Sociology as based upon Anthropology.
Am. Jour, of Soc. Sci., 1898.
Anthropologic Philosophique. (In press.)
CLEMENS JAMES FRANCE: —
A.B., Hamilton College, 1898; Scholar
in Psychology, Clark University,
1898-99.
Author of: —
The Psychology of Ownership. (With
L. W. Kline.) Pedagogical Seminary.
(In press.)
494
Titles of
JOSEPH IRWIN FRANCE: —
A.B., Hamilton College (Root Scientific
Fellowship, with Honors in Biology),
1895 ; Student, University of Leipzig,
1895-96 ; Scholar in Psychology, Clark
University, 1896-97 ; A.M. (honorary),
Hamilton College, 1898 ; Supervisor and
Instructor in Science, Jacob Tome Insti-
tute, Port Deposit, jMd., 1897- ; Student,
College of Physicians and Surgeons, Balti-
more. Md., 1898-99.
Author of : —
The Conservation of Cosmos. An Essay.
Gressner & Schramm, Leipzig, 1896.
18 pp.
Nature-Study. Educational Beview,
March, 1899, Vol. 17, pp. 292-295.
ALEXANDER FRASER : —
A.B., Dalhousie College, 1889; Graduate
Student, Harvard University, 1889-90;
Fellow in Psychology, Clark Uni-
versity, 1891-92 ; Student in Medicine,
Dalhousie University, 1893-97 ; M.D.,
CM., ibid., 1897 ; Lecturer in Psychology,
Halifax Ladies' College, 1893-94; In-
structor in Psychology, Halifax School for
the Blind, 1894-95 ; House Surgeon, Vic-
toria General Hospital, Halifax, N. S.,
1897-98 ; Practising Physician and Sur-
geon, New Glasgow, N. S., 1898-.
Author of : —
Visualization as a Chief Source of the Psy-
chology of Hobbes, Locke, Berkeley,
and Hume. Am. Jour, of Fsy., Dec,
1891, Vol.4, pp. 230-247.
The Psychological Foundation of Natural
Realism. Ibid., April, 1892, Vol. 4,
pp. 429-450.
The Psychological Basis of Hegelism.
Ibid., July, 1893, Vol. 5, pp. 472-495.
JOHN S. FRENCH : —
A.B., Bowdoin College, 1895; Scholar
in Mathematics, Clark University,
1895-96; Fellow, 1896-98; Ph.D.,
Clark University, 1898 ; Supervisor and
Instructor in Mathematics, Jacob Tome
, Institute, 1898-.
Author of : —
On the Theory of the Pertingents to a
Plane Curve. (In press. )
JOHN PHELPS FRUIT : —
A.B., Bethel College, Ky.,1878; Instruc-
tor of Latin and Mathematics, High
School, Parker's Grove, Ky., 1878-79 ;
Professor of Latin and Greek, Bardstown
Institute, Ky., 1879-81 ; A.M., Bethel
College, 1881 ; President, Liberty Female
College, Glasgow, Ky., 1881-83 ; Professor
of English Literature, Bethel College,
188:3-97 ; Scholar in Psychology, Clark
University, 1891 ; Graduate Student,
University of Leipzig, 1894-95; Ph.D.,
University of Leipzig, 1895 ; Professor of
English Language and Literature, William
Jewell College, 1897-; Memberof : Modern
Language Association, American Dialect
Society, American Statistical Association,
Southern History Association.
Author of : —
The Evolution of Figures of Speech.
Modern Language Notes, Dec, 1888.
Browning and Tennyson. Ibid., May,
1890.
A Plea for the Study of Literature from
the -Esthetic Standpoint. Pub. of the
Modern Language Ass''n, 1891, Vol. 6,
No. 1.
Shakespeare's Egoism. Poet Lore, Sept.,
1899, Vol. 1, pp. 406-407.
The Destiny of Marriage : Portia and the
Caskets. Ibid., Feb., 1891, Vol. 3,
pp. 69-74.
Uncle Remus in Phonetic Spelling. Dia-
lect Notes, Boston, 1892, Part 4, pp.
196-198.
The Ideal the Need of the People. Soxith-
ern Magazine, May, 1894.
John Milton. Seminary Magazine (Louis-
ville, Ky.), March, 1899.
The Mind and Art of Poe's Poetry. A. S.
Barnes & Co., New York, 1899. 144 pp.
HOMER GAGE:—
A.B., Harvard University, 1882; A.M.,
ibid., 1887; M.D., ibid., 1887; Physician
and Surgeon, Worcester, Mass., 1888- ;
Published Pampers.
495
Honorary Scholar in Anatomy, Clark
University, 1889-90 ; Surgeon to Me-
morial, St. Vincent, and Worcester City-
Hospitals ; Consulting Surgeon to Baldwin-
ville Cottage Hospital.
BENJAMIN IVES GILMAN : —
A.B., Williams College, 1872; A.M.,
ibid., 1880; Fellow, Johns Hopkins Uni-
versity, 1881-83 ; Lecturer at Princeton,
Harvard, and Columbia, 1890-91 ; In-
structor in Psychology, Clark Uni-
versity, 1892-93 ; Curator, Museum of
Fine Arts, Boston, Mass., 1893-.
Author of: —
On Propositions and the Syllogism. On
Propositions called Spurious. J. H.
U. Circular, Aug., 1882, pp. 240-241.
On Operations in Relative Number. Johns
Hopkins Studies in Logic, 1882.
A Study of the Inductive Theories of
Bacon, Whewell, and Mill. Colorado
College Studies, 1890, pp. 17-26.
Zuni Melodies. Jour, of Am. Arch, and
Eth., Vol. 1, 1891, pp. 65-91.
On some Psychological Aspects of the
Chinese Musical System. Philosophi-
cal Bevieio, Jan. and March, 1892, Vol.
1, pp. 54-71, 154-178.
On the Properties of a One-dimensional
Manifold. 3Iind, Oct., 1892, N. S.,
Vol. 1, pp. 518-526.
Report on an Experimental Test of Musi-
cal Expressiveness. Am. Jour, of Psy.,
Vols. 4 and 5, Aug. and Oct., 1892.
Syllabus of Lectures on the Psychology of
Pain and Pleasure. Ibid., Oct., 1893,
Vol. 6, pp. 3-60.
HENRY H. GODDARD:—
A.B., Haverford College, 1887; A.M.,
ibid., 1889 ; Instructor in Latin and His-
tory, University of Southern California,
1887-88 ; Graduate Student, Haverford
College, 1888-89 ; Principal, Damascus
Academy, Ohio, 1889-91 ; Instructor in
Latin and Greek, Oak Grove Seminary,
Vassalboro, Me., 1891-93 ; Principal, ibid.,
1893-96 ; Scholar in Psychology, Clark
University, 1896-97 ; Fellow, 1897-
99 ; Ph.D., Clark University, 1899 ;
Professor of Psychology and Pedagogy,
State Normal School, West Chester, Pa.,
1899-.
Author of : —
The Effects of Mind on Body as evidenced
by Faith Cures. Am. Jour, of Psy.,
April, 1899, Vol. 10, pp. 431-502.
JOHN H. GRAY, JR.—
B.S., University of California, 1887; As-
sistant to State Analyst, California, 1887-
90 ; Assistant in Chemistry, University
of California, 1889-90 ; Instructor in
Chemistry, ibid, 1890-92 ; Fellow in
Chemistry, Clark University, 1892-
94 ; Instructor in Physics and Chemistry,
State Normal School, Chico, Cal., 1894-
95 ; Assistant in Chemistry, University of
California, 1895-96 ; Instructor in Chem-
istry, ibid., 1896-.
CEPHAS GUILLBT: —
A.B., Victoria University, Cobourg,
Ont. (Honors in English, French and
German Literature), 1887 ; Modern Lan-
guage Master, Perth, Ont. , 1887-90 ;
Modern Language Master, Ottawa, Ont.,
1890-94 ; Student at Law, Osgoode Hall,
Toronto, 1894-95 ; Scholar in Psy-
chology, Clark University, 1895-96 ;
Fellow, 1896-98.
R. R. GURLEY: —
United States Naval Academy, 1877-79 ;
Assistant Resident Physician, Children's
Hospital, Washington, D. C, 1882-84 ;
M.D. (First Honor), National Medical
College, Washington, D. C, 1884 ; Resi-
dent Physician, United States Soldiers'
Home Hospital, Washington, D. C, 1884-
85 ; Scientific Assistant, United States
National Museum, Washington, D. C,
1886-90 ; Scientific Assistant, Biological
Laboratory, United States Fish Com-
mission, Washington, D. C, 1890-95 ; M.
Sc, Columbian University, 1895 ; Fellow
in Biology, Clark University, 1895-
96 ; Junior Assistant Physician, Worcester
Insane Hospital, 1896-97 ; Assistant Phy-
sician, ibid., 1897-.
496
Titles of
Author of: —
The Geologic Age of the Graptolite
Shales of Arkansas. Ann. Bep. Geol.
Survey, Arkansas, 1890, Vol. 3, pp.
401-418, PI. 9.
Some Recent Graptolite Literature.
American Geologist, 1891, pp. 35-43.
The Classification of the Myxosporidia,
a Group of Protozoan Parasites infest-
ing Fishes. Bull. U. 8. Fish Com.,
1891, pp. 407-420.
The Myxosporidia, or Psorosperms of
Fishes, and the Epidemics produced
by them. Rep. U. S. Fish. Com.,
1892, pp. 65-304, PI. 1-47.
The North American Graptolites. Journal
of Geology, 1896, Vol. 4, pp. 63-102 ;
291-311. PI. 4-5.
G. STANLEY HALL : —
A.B., Williams College, 1867; A.M.,
1870 ; Union Theological Seminary, N. Y.,
1867-68 ; Universities Berlin and Bonn,
1869-70 ; Union Theological Seminary,
N. Y., 1870-71; Universities of Berlin
and Heidelberg, 1871-72 ; Professor of
Philosophy, Antioch College, 1872-76;
Instructor, Harvard University, 1876-78 ;
Ph.D., Harvard University, 1878; Uni-
versitieb of Berlin and Leipzig, 1878-80 ;
Lecturer in Harvard University and
Williams College, 1880-81 ; Professor of
Psychology, Johns Hopkins University,
1881-88 ; LL.D., University of Michigan,
1888, and Williams College, 1889 ; Presi-
dent, and Professor of Psychology,
Clark University, 1888- ; Editor and
Founder of American Journal of Psychol-
ogy (Founded in 1887), and Pedagogical
Seminary (Founded in 1891) ; Resident
Fellow of the American Academy of Arts
and Sciences ; Resident Member of the
Massachusetts Historical Society ; Mem-
ber of American Antiquarian Society.
Author of : —
John Stuart Mill. Williams Quarterly,
Williamstown, Mass., Aug., 1867.
Digest of Dorner's Theology. Presby-
terian Revieio, Jan., 1873, pp. 60-93.
Hegel as the National Philosopher of Ger-
many. (Translated from the German
of Dr. Carl Rosenkranz. ) Gray, Baker,
& Co., St. Louis, 1874. 159 pp.
Hegel : His Followers and Critics. Jour,
of Spec. Philos., 1878, Vol. 12, pp. 93-
103.
Color Perception. Proc. Am. Acad, of
Arts and Sciences, March, 1878, Vol.
3, pp. 402-413.
The Muscular Perception of Space. Mind,
Oct., 1878, Vol. 3, pp. 433-450.
The Philosophy of the Future. Nation,
Nov. 7, 1878, Vol. 27, pp. 283-284.
Philosophy in the United States. Mind,
Jan., 1879, Vol. 4, pp. 89-105; also
Pop. Sci. Mo., Suppl. No. 1, 1879, p. 57.
Ueber die Abhangigkeit der Reactions-
zeiten vom Ort des Reizes. (With
J. V. Kries.) Archiv f. Physiol. (Du
Bois-Reymond), Suppl. Band, 1879,
pp. 1-10.
Die willkiirliche Muskelaction. (With
Hugo Kronecker.) Ibid., pp. 11-47.
Laura Bridgman. 3Iind, April, 1879,
Vol. 4, pp. 149-172.
Recent Researches in Hypnotism. Ibid.,
Jan., 1881, Vol. 6, pp. 98-104.
Aspects of German Culture. James R.
Osgood & Co., Boston, 1881. 320 pp.
Moral and Religious Training of Children.
Princeton Review, Jan., 1882, Vol. 10,
pp. 26-48.
Chairs of Pedagogy in our Higher Institu-
tions of Learning. N. E. A., March,
1882 ; U. S. Bur. of Ed., Circular of
Information, No. 2, 1882, pp. 35-44.
Optical Illusions of Motion. (With Dr.
H. P. Bowditch.) Jour. ofPhys., Aug.,
1882, Vol. 3, pp. 297-307.
The Education of the Will. Princeton
Reviev), Nov., 1882, Vol. 10, pp. 306-
325. Reprinted in Pedagogical Semi-
nary, June, 1892, Vol. 2, pp. 72-89.
Methods of Teaching History. (Edited.)
Ginn, Heath & Co., Boston, 1883.
xii. 4- 296 pp.
Educational Needs. N. A. Rev., March,
1883, Vol. 136, pp. 284-290.
Reaction-Time and Attention in the Hyp-
notic State. Mind, April, 1883, Vol. 8,
pp. 170-182.
Published Papers.
497
Contents of Children's Minds on entering
School. Princeton Beview, May, 1883,
Vol. 11, pp. 249-272; Pedagogical
Seminary, June, 1891, Vol. 1, pp. ISO-
ITS. Issued in pamphlet form by
E. L. Kellogg & Co., New York, 1893.
56 pp.
Education and Theology. Nation, July
26, 1883, Vol. 37, pp. 81-82.
The Study of Children. (Privatelyprinted.)
N. Somerville, Mass., 1883, 13 pp.
Report of the Visiting Committee of the
Alumni of Williams College, Williams-
town, Mass., 1884. 11 pp.
Bilateral Asymmetry of Function. (With
E. M. Hartwell.) Mind, Jan., 1884,
Vol. 9, pp. 93-109.
New Departures in Education. N. Am.
Bev., Feb. 1885, Vol. 140, pp. 144-
152.
The New Psychology. Andover Beview,
Feb. and March, 1885, Vol. 3, pp. 120-
135, 239-248. Opening lecture, Johns
Hopkins University, Oct. , 1884,
Experimental Psychology. Mind, April,
1885, Vol. 10, pp. 245-249.
Children's Collections. Nation, Sept. 3,
1885, Vol. 41, p. 190; reprinted in
Pedagogical Seminary, June, 1891,
Vol. 1, pp. 234-237.
Overpressure in Schools. Nation, Oct.
22, 1885, Vol. 41, pp. 338-339.
Motor Sensations of the Skin. (With
Dr. H. H. Donaldson.) Mind, Oct.,
1885, Vol. 10, pp. 557-572.
Studies of Rhythm. (With Joseph Jas-
trow.) Ihid., Jan., 1886, Vol. 11, pp.
55-62.
Hints toward a Select and Descriptive
Bibliography of Education. (With
John M. Mansfield.) D. C. Heath &
Co., Boston, 1886. 309 pp.
Psychical Research. Am. Jour, of Psy.,
Nov., 1887, Vol. 1, pp. 128-146.
Psychology. (Reviews.) Am. Jour, of
Psy., Nov., 1887, Vol. 1, pp. 146-164.
Dermal Sensitiveness to Gradual Pressure-
Changes. (With Y. Motora.) Ibid.,
Nov., 1887, Vol. 1, pp. 72-98.
The Story of a Sand Pile. Scribner^s
Magazine, June, 1888, Vol. 3, pp.
2k
690-696. Reprint, E. L. Kellogg & Co.,
N. Y., 1897. 20 pp.
Introduction to American Edition of
Preyer's Senses and Will. (Translated
by H. W. Brown.) New York, 1888.
Address Delivered at the Opening of Clark
University, Opening Exercises, pp. 9-
32, Worcester, Mass., Oct, 2, 1889,
(Published by the University,)
A Sketch of the History of Reflex Action.
Am. Jour, of Psy., Jan., 1890, Vol. 3,
pp. 71-86.
How to teach Reading, and What to Read
in School. D. C. Heath & Co., Boston,
1890. 40 pp. (First edition, 1886.)
Children's Lies. Am. Jour, of Psy., Jan.,
1890, Vol. 3, pp. 59-70. Reprinted in
Pedagogical Seminary, June, 1891,
Vol, 1, pp. 211-218.
The Training of Teachers. Forum, Sep-
tember, 1890, Vol. 10, pp. 11-22.
First Annual Report to the Board of
Trustees of Clark University, Worces-
ter, Mass., Oct. 4, 1890. 53 pp.
University Study of Philosophy. Discus-
sion. Begents' Bep. Univ., State of
New York, 1891, Vol. 105, pp. 335-338.
Boy Life in a Massachusetts Country Town
Thirty Years Ago. Proc. Am. Antiq.
Soc, Worcester, Mass., 1891, N. S.,
Vol. 7, pp. 107-128.
Educational Reforms. Pedagogical Semi-
nary, Jan., 1891, Vol. 1, pp. 1-12.
Appeared also as Riforme Pedagogiche
in II Bisveglio Educativo, Aprile 13-
16, 1892, Anno 8, pp. 207-208, 210-211.
The Principles of Psychology. By William
James. (Review.) Am. Jour, of Psy.,
Feb., 1891, Vol. 3, pp. 578-591.
Contemporary Psychologists. I. Edward
Zeller. Ibid., April, 1891, Vol. 4, pp.
156-175.
Enseignement des Sciences. Bevue Sci-
entifique, April 4, 1891, Vol. 47, pp.
430-433,
Notes on the Study of Infants. Peda-
gogical Seminary, June, 1891, Vol. 1,
pp. 127-138.
The Moral and Religious Training of
Children and Adolescents. Ibid., pp.
196-210.
498
Titles of
Second Annual Report to the Board of
Trustees of Clark University, Worces-
ter, Mass., Sept. 29, 1891. 56 pp.
The New Movement in Education. An
address delivered before the School of
Pedagogy of the University of the City
of New York, Dec. 29, 1891. Pub-
lished by the Women's Advisory Com-
mittee, New York, 1891. 20 pp.
The Outlook in Higher Education. Acad-
emy, Boston, Mass., Jan., 1892, Vol.
6, pp. 543-562.
Health of School Children as affected
by School Buildings. Beport of Proc.
Dept. of Superintendence, held in
Brooklyn, N. Y., Feb., 1892, pp. 163-
172. Also Proc. N. E. A., 1892, pp.
682-691.
Moral Education and Will Training.
Pedagogical Seminary, June, 1892,
Vol. 2, pp. 72-89.
Child-study as a Basis for Psychology and
Psychological Teaching. Beport of
Com. 0/ £■(?., 1892-93, Washington, D.C.,
1895, Vol. 1, pp. 357-358, 366-370.
Third Annual Report to the Board of
Trustees of Clark University, Worces-
ter, Mass., April, 1893. 168 pp.
Psychological Progress. The Liberal Club,
Buffalo, N. Y., Nov. 16, 1893.
Child-study : The Basis of Exact Educa-
tion. Forum, Dec, 1893, Vol. 16,
pp. 429-441.
American Universities and the Training
of Teachers. Ibid., April, 1894, Vol.
17, pp. 148-159.
Universities and the Training of Pro-
fessors. Ibid., May, 1894, Vol. 17,
pp. 297-309.
Scholarships, Fellowships, and the Train-
ing of Professors. Ibid., June, 1894,
Vol. 17, pp. 443-454.
Research the Vital Spirit of Teachmg.
Ibid., July, 1894, Vol. 17, pp. 558-570.
Child-study in Summer Schools. Begents'
Bulletin, University of the State of
New York, No. 28, July, 1894. Albany,
N. Y., 1895, Vol. 1, pp. 333-336.
The New Psychology as a Basis of Edu-
cation. Forum, Augixst, 1894, Vol. 17,
pp. 710-720.
Address at the Bryant Centennial, Aug.
16, 1894. Bryant Memorial, Cum-
mington, Mass., 1894, pp. 67-69.
Address. Dedication of the Hasten Free
Public Library Building, North Brook-
field, Mass., September 20, 1894. pp.
11-21.
On the History of American College Text-
Books and Teaching in Logic, Ethics,
Psychology, and Allied Subjects.
Proc. Am. Antiq. Soc, Worcester,
Mass., 1894, N. S., Vol. 9, pp. 137-174.
Remarks on Rhythm in Education. Proc.
N. E. A., 1894, pp. 84-85.
Child-study. Ibid., 1894, pp. 173-179.
Practical Child-study. Jour, of Ed., Dec.
13, 1894, Vol. 40, pp. 391-392.
Topical Syllabi for 1894-1895. These
were one- or two-page leaflets, pre-
pared by Dr. Hall, and privately printed
at Worcester, jNIass. They covered :
I. Anger ; II. Dolls ; III. Crying and
Laughing ; IV. Toys and Playthings ;
V. Folk-Lore Among Children ;
VI. Early Forms of Vocal Expres-
sion ; Vn. The Early Sense of Self
VIII. Fears in Childhood and Youth
IX. Some Common Traits and Habits
X. Some Common Automatisms,
Nerve Signs, etc. ; XI. Feeling for Ob-
jects of Inanimate Nature ; XII. Feel-
ing for Objects of Animate Nature ;
XIII. Children's Appetites and Foods ;
XIV. Affection and its Opposite States
in Children ; XV. Moral and Religious
Experiences.
Laboratory of the McLean Hospital,
Somerville, Mass. Am. Jour, of In-
sanity, Jan., 1895, Vol. 51, pp. 358-
364.
Psychic Research. Am. Jour, of Psy.,
Oct., 1895, Vol. 7, pp. 135-142.
Results of Child-study applied to Educa-
tion. Trans. III. Soc. for Child-study,
1895, Vol. 1, No. 4, p. 13.
Introduction to the Psychology of Child-
hood. By Frederick Tracy. Boston,
1895.
Address at Union College Centennial An-
niversary, June 24, 1895. Printed by
the College. N. Y., 1897, pp. 230-244.
Published Papers.
499
Topical Syllabi for 1895-96. I. Peculiar
and Exceptional Children, with E. W.
Bohannon ; II. Moral Defects and
Perversions, with G. E. Dawson ; III.
The Beginnings of Reading and Writ-
ing, with Dr. H. T. Lukens ; IV.
Thoughts and Feelings about Old Age,
Disease, and Death, with C. A. Scott ;
V. Moral Education, with N. P.
Avery ; VI. Studies of School Read-
ing Matter, with J. C. Shaw; VII.
Courses of Study in Elementary Gram-
mar and High Schools, with T. R.
Crosswell ; VIII. Early Musical Mani-
festations, with Florence Marsh; IX.
Fancy, Imagination, Reverie, with E.
H. Lindley ; X. Tickling, Fun, Wit,
Humor, Laughing, with Dr. Arthur
Allin ; XI. Suggestion and Imitation,
with M. H. Small ; XII. Religious
Experience, with E. E. Starbuck ;
XIII. Kindergarten, with Miss Anna
E. Bryan and Miss Lucy Wheelock ;
XIV. Habits, Instincts, etc., in Ani-
mals, with Dr. R. R. Gurley ; XV.
Number and Mathematics, with D. E.
Phillips; XVI. The Only Child in
the Family, with E. W. Bohannon.
The Case of the Public Schools. Atlantic
Monthly, March, 1896, Vol. 77, pp.
402-413.
Psychological Education. Proc. of the
Am. Medico-Psychological Ass^n. 52d
Annual Meeting, Boston, May 26-29,
1896, Transactions, Vol. 3, pp. 87-
100 ; also, Am. Jour, of Insanity, Oct.
1896, Vol. 53, pp. 228-241.
Generalizations and Directions for Child-
study. Northwestern Jour, of Ed.,
July, 1896, Vol. 7, p. 8-
Address at Mount Holyoke College,
Founder's Day, Nov. 5, 1896. Mount
Holyoke, S. Hadley, Mass. Nov., 1896,
Vol. 6, pp. 64-71.
A Study of Dolls. (With A. C. Ellis.)
Pedagogical Seminary, Dec, 1896.
Vol. 4, pp. 129-175. Reprint, E. L.
Kellogg & Co., N. Y., 1897. 69 pp.
Nature Study. Proc. N. E. A., 1896.
pp. 156-158.
The Methods, Status, and Prospects of the
Child-study of To-day. Trans. III.
Soc. for Child-study, May, 1896, Vol.
2, pp. 178-191.
Topical Syllabi for 1896-97. I. Degrees of
Certainty and Conviction in Children,
with Maurice H. Small; II. Sabbath
and Worship in General, with J. P.
Hylan; III. Migrations, Tramps,
Truancy, Running Away, etc., vs.
Love of Home, with L. W. Kline ; IV.
Adolescence, and its Phenomena in
Body and Mind, with E. C. Lancaster ;
V. Examinations and Recitations, with
John C. Shaw ; VI. Stillness, Solitude,
Restlessness, with H. S. Curtis ; VII.
The Psychology of Health and Disease,
with Henry H. Goddard ; VIII. Spon-
taneously Invented Toys and Amuse-
ments, with T. R. Crosswell; IX.
Hymns and Sacred Music, with Rev.
T. R. Peede ; X. Puzzles and their
Psychology, with Earnest H. Lindley ;
XL The Sermon, with Rev. Alva R.
Scott ; XII. Special Traits as Indices
of Character and as Mediating Likes
and Dislikes, with E. W. Bohannon ;
XIII. Reverie and Allied Phenomena,
with G. E. Partridge ; XIV. The Psy-
chology of Health and Disease, with H.
H. Goddard.
A Study of Fears. Am. Jour, of Psy.,
Jan., 1897, Vol. 8, pp. 147-249.
Some Practical Results of Child-study.
First National Congress of Mothers,
Washington, D. C, 1897. D. Apple-
ton and Co., New York, 1897. pp.
165-171.
The Psychology of Tickling, Laughing, and
the Comic. (With Arthur Allin.) Am.
Jour, of Psy., Oct., 1897, Vol. 9, pp.
1-41.
Topical Syllabi for 1897-98. I. Immortal-
ity, with J. Richard Street ; II. Psy-
chology of Ownership vs. Loss, with
Linus W. Kline ; III. Memory, with
F. W. Colegrove ; IV. Humorous and
Cranky Side in Education, with L. W.
Kline ; V. The Psychology of Short-
hand Writing, with J. O. Quantz ; VI.
The Teaching Instinct, with D. E.
Phillips ; VII. Home and School Pun-
500
Titles of
ishments and Penalties, with Chas.
H. Sears; VIII. Straightness and
Uprightness of Body ; IX. Conven-
tionality, with Albert Schinz ; X.
Local Voluntary Association among
Teachers, with Henry D. Sheldon ;
XI. Motor Education, with E. W.
Bohannon ; XII. Heat and Cold ;
XIII. Training of Teachers, with
W. G. Chambers ; XIV. Educational
Ideals, with Lewis Edwin York ; XV.
Water Psychoses, with Frederick E.
Bolton; XVI. The Institutional Ac-
tivities of Children, with Henry D.
Sheldon ; XVII. Obedience and Obsti-
nacy, with Tilmon Jenkins ; XVIII.
The Sense of Honor Among Children,
with Robert Clark.
Some Aspects of the Early Sense of Self.
Am. Jour, of Psy., April, 1898, Vol. 9,
pp. 351-395.
Initiations into Adolescence. Proc. of
Am. Antiq. Soc, Worcester, Mass.,
Oct. 21, 1898, N. S. Vol. 12, p. 367-
400.
The Love and Study of Nature : A Part of
Education. Agriculture of Massachu-
setts, for 1898, pp. 134-154.
Topical Syllabi for 1898-99. L The Organ-
izations of American Student Life, with
Henry D. Sheldon ; II. Mathematics
in Common Schools, with E. B. Bryan ;
III. Mathematics in the Early Years,
with E. B. Bryan ; IV. Unselfishness
in Children, with Willard S. Small ;
V. The Fooling Impulse in Man and
Animals, with Normal Triplett ; VI.
Confession, with Erwin W. Runkle ;
VII. Pity ; VIII. Perception of
Ehythm by Children, with Chas. H.
Sears.
R6sum6 of Child-study, Northxoestern
Monthly, March-April, 1899, Vol. 9,
pp. 347-349. Paidologist, Chelten-
ham, Eng., April, 1899, Vol. 1, pp. 5-8.
The Kindergarten. School and Home
Education, Bloomington, 111., June,
1899, Vol. 18, pp. 507-509.
A Study of Anger. Am. Jour, of Pay.,
July, 1899, Vol. 10, pp. 516-591.
The Line of Educational Advance. Out-
look, Aug. 5, 1899, Vol. 62, pp. 768-
770.
T. PROCTOR HAIiL: —
B.A., University of Toronto, 1882 ; Fel-
low and Instructor in Chemistry, ibid.,
1883-84; B.A., McMaster University,
Toronto, 1894 ; M.A., and Ph.D., Illi-
nois Wesleyau University, 1888 ; Science
Master, Woodstock College, Wood.stock,
Ont., 1885-90 ; FeUow in Physics,
Clark University, 1890-93 ; Ph.D.,
Clark University, 1893 ; Professor of
Natural Sciences, Tabor College, Iowa,
1893-96 ; Professor of Physics, Kansas
City University, 1898- ; President Society
of Economics, Kansas City ; Vice-Presi-
dent Ex-Canadian Society, Kansas City.
Author of : —
The Projection of Four-fold Figures upon
a Three-flat. Am. Jour, of Math.,
April, 1893, Vol. 15, pp. 179-189.
The Possibility of a Realization of Four-
fold Space. Science, May 13, 1892.
New Methods of Measuring the Surface
Tension of Liquids. Philosophical
Magazine, Nov., 1893, Vol. 36, pp.
385-413.
Graphic Representation of the Properties
of the Elements. Proc. Iowa Acad,
of Sci., 1894.
A Mad-Stone. Ibid., 1895.
Physical Theories of Gravitation. Ibid.,
1895.
Unit Systems and Dimensions. Electrical
World, Feb. 7, 1896.
A Physical Theory of Electricity and
Magnetism. Ibid., July 3, 1897, Vol.
30, pp. 10-12.
The Vortex Theory of Electricity and
Magnetism. Home Study for Elec-
trical Workers, Sept., 1898, pp. 34-36.
Complex Algebra of the Plane Extended
to Three-fold Space. Proc. Iowa Acad,
of Sci., 1898, Vol, 6.
JOHN A. HANCOCK: —
B.S., Baker University, 1877; Principal
of Schools, Indiana and Wisconsin, 1877-
89 ; Graduate Student in Pedagogy, Uni-
Published Papers.
501
versity of Wisconsin, 1889-90; M.L.,
ibid., 1890; City Superintendent, Green
Bay, Wis., 1890-92 ; Graduate Student
in Pedagogy, Leland Stanford Jr. Univer-
sity, 1892-93; M.A., ihid., 1893; Fellow
in Pedagogy, Clark University, 1893-
94 ; Superintendent of Schools, Durango,
Col. , 1894-97 ; Temporary Assistant Pro-
fessor of Psychology, University of Colo-
rado, 1897-98 ; Superintendent of Schools,
Santa Barbara, Cal., 1899-.
Author of : —
Secularization of Education. Wis. Jour.
of Ed., March, 1890.
Preliminary Study of Motor Ability.
Pedagogical Seminary, Oct., 1894, Vol.
3, pp. 9-29.
The Kindergarten and Child Study. Col.
School Jour., Feb., 1895.
The Relation of Strength to Flexibility in
the Hands of Men and Children. Peda-
gogical Seminary, Oct., 1895, Vol. 3,
pp. 308-313.
Children's Ability to Reason. Educa-
tional Review, Oct., 1896, Vol. 12, pp.
261-268.
An Early Phase of the Manual Training
Movement — the Manual Labor School.
Pedagogical Seminary, Oct., 1897, Vol.
5, pp. 287-292.
Mental Differences of School Children.
Proc. N. E. A., 1897, pp. 851-857.
Children's Tendencies in the Use of Writ-
ten Language Forms. Northwestern
Monthly, June, 1898, Vol. 8, pp. 646-
649.
ROLLIN A. HARRIS: —
Ph.B., Cornell University, 1885; Fellow
in Mathematics, ibid., 1886-87 ; Ph.D.,
ibid., 1888 ; Fellow in Mathematics,
Clark University, 1889-90 ; Computer,
United States Coast and Geodetic Survey,
Washington, D.C., 1890-.
Author of : —
The Theory of Images in the Representa-
tion of Functions. Annals of Math.,
1888, Vol. 4, pp. 65-86, 128.
On the Expansion of snj. Ibid., Vol.
4, pp. 87-90.
Design for a Conicograph. Scien. Am.
Supp., 1890, No. 740.
On the Invariant Criteria for the Reality
of the Roots of the Quintic. Annals
of Math., 1891, Vol. 5, pp. 219-228.
On Certain Bicircular Quartics Analogous
to Cassini's Oval. Mathematical Maga-
zine, Vol. 2, pp. 77-79.
Note on Isogonal Transformations ; Par-
ticularly on obtaining Certain Systems
of Curves which Occur in the Statics
of Polynomials. Annals of Math.,
1891, Vol. 6, pp. 77-80.
Note on the Use of Supplementary Curves
in Isogonal Transformation. Am.
Jour, of Math., 1892, Vol. 14, pp. 291-
300.
Some Connections between Harmonic and
Non-harmonic Quantities, Including Ap-
plications to the Reduction and Predic-
tion of Tides. U. S. Coast and Geod.
Sur. Report, 1894, Appendix, No. 7
(Manual of Tides, Part III.).
Introduction and Historical Treatment of
the Subject, Ibid., 1897, Appendix,
No. 8 (Manual of Tides, Part I.).
Tidal Observation, Equilibrium Theory,
and the Harmonic Analysis, Ibid.,
1897, Appendix, No. 9 (Manual of
Tides, Part II.).
A Proposed Tidal Analyzer. Physical
Review, 1899, Vol. 8, pp. 54-60.
JAMES N. HART: —
B.C.E., Maine State College, 1885 ; Prin-
cipal of High School, Dennysville, Me.,
1885 ; Instructor in Mathematics and
Drawing, Maine State College, 1887-90 ;
C.E., ibid., 1890 ; Scholar in Mathe-
matics, Clark University, 1890-91 ;
Professor of Mathematics and Astronomy,
University of Maine, 1891-; Graduate Stu-
dent in Mathematics and Astronomy, Uni-
versity of Chicago, 1894-95; M.S., ibid.,
1897 ; Member of American Mathematical
Society.
S. B. HASLETT: —
Graduate, Edinboro, Pa., State Normal
School, 1885 ; Principal, Creighton Pub-
lic Schools, 1887-88; A.B., Grove City
502
Titles of
College, Pa., 1889; Principal, Braddock
High School, 1891-92 ; Graduate, Alle-
gheny Theological Seminary, 1892 ; Pres-
byterian Ministry, 1892-; A.M., Grove
City College, 1896 ; Scholar in Psy-
chology, Clark University, 1898-99.
N. B. HELLER: —
B.S., University of Pennsylvania, 1884;
Professor of Mathematics, Boys' High
School, Reading, Pa., 1887-91; Scholar
in Mathematics, Clark University,
1891-92 ; Fellow in Mathematics, Uni-
versity of Chicago, 1892-93 ; Assistant
Professor in ]\Iathematics, Drexel Insti-
tute, Philadelphia, 1893-.
CLARK •WILSON HETHERINGTON :
A.B., Leland Stanford Jr. University,
1895 ; Instructor, Encina Gymnasium,
Stanford University, 1893-96 ; Statistician
and Director of Physical Training, Whit-
tier State Reform School, 1896-98 ; Fel-
low in Psychology, Clark University,
1898-99.
JOHN E. HILL : —
Ph.B., Sheffield Scientific School (Yale),
1885 ; Resident Engineer, C. M. and St.
Paul R.R., 1885-88; Professor of Mathe-
matics, Military Academy, Louisville,
Ky., 1888-89 ; Superintendent of Schools,
Pleasantville, N, Y., 1889-90; Professor
of Mathematics and Civil Engineering,
Highland Park College, 1890-92 ; Fellow
in Mathematics, Clark University,
1892-95 ; Ph.D., Clark University,
1895; Tutor in Mathematics, Columbia
University, 1895-97 ; Teacher of Mathe-
matics, Manual Training High School,
Brooklyn, N. Y., 1897-98 ; Teacher of
Science, High School, Stamford, Ct.,
1898-99.
Author of : —
On Quintic Surfaces. Mathematical Be-
vieiv, July, 1896, Vol. 1, pp. 1-59.
Bibliography of Surfaces and Twisted
Curves. Btill. A771. Math. Soc, Jan.,
1897, Vol. 3, pp. 133-146.
On Three Septic Surfaces. Am. Jour, of
Math., Oct., 1897, Vol. 19, pp. 289-311.
BENJAMIN C. HINDE : —
A.B., Central College, Missouri, 1881 ;
A.M., ibid., 1882; Instructor in Physical
Sciences, Howard College, 1882-88 ; Grad-
uate Student, Johns Hopkins University,
1888-90 ; Professor of Physics and Chem-
istry, State Normal College, Mo., 1890-91 ;
Professor of Physics, Trinity College, N.
C, 1891-92; Fellow and Assistant in
Physics, Clark University, 1892-93 ;
Professor of Physics, Trinity College,
N. C, 1893-94.
Died Feb. 6, 1894.
CLIFTON F. HODGE: —
A.B., Ripon College, 1882; Civil En-
gineer, Montana, 1882-86 ; Graduate Stu-
dent, Johns Hopkins University, 1886-88 ;
Fellow in Biology, ibid, 1888-89 ; Ph.D.,
Johns Hopkins University, 1889 ; Fellow
in Psychology and Assistant in Neu-
rology, Clark University, 1889-91 ;
Instructor in Biologj% University of Wis-
consin, 1891-92 ; Assistant Professor
of Physiology and Neurology, Clark
University, 1892- ; Member of : Ameri-
can Physiological Society, Society Ameri-
can Naturalists, Massachusetts Forestry
Association, Boston Society of Medical
Sciences.
Author of : —
Some Effects of Stimulating Ganglion
Cells. Am. Joxir. of Psy., May, 1888,
Vol. 1, pp. 479-486.
Some Effects of Electrically Stimulating
Ganglion Cells. Ibid., May, 1889, Vol.
2, pp. 376-402.
A Study of the Oyster Beds of Long
Island Sound with Reference to the
Ravages of Starfish. J. H. U. Circular,
Sept., 1889, No. 75, Vol. 8, p. 102.
A Sketch of the History of Reflex Action.
Am. Jour, of Psy., April and Sept.,
1890, Vol. 3, pp. 149-167, 343-363.
The Process of Recovery from the Fatigue
occasioned by the Electrical Stimula-
tion of Cells of the Spinal Ganglia.
Ibid., Feb., 1891, Vol. 3, pp. 530-
543.
Homing Pigeons, .^gis, Jime, 1892.
Published Papers.
503
A Microscopical Study of Changes due to
Functional Activity in Nerve Cells.
Jour, of 3Iorph., Nov., 1892, Vol. 7,
pp. 95-168.
The Method of Homing Pigeons. Pop.
Sci. Mo., April, 1894, Vol. 44, pp.
758-775.
Changes in Ganglion Cells from Birth to
Senile Death. Observations on Man
and Honeybee. Jour, of Fhys., 1894,
Vol. 17, pp. 129-134.
Botanical Gardens. Wor. Co. Hort. 8oc.
Sep., 1894-95, pp. 102-117.
Die Nervenzelle bei der Geburt und beim
Tode an Alterschwache. Anat. An-
zeiger, Aug. 1, 1894, Vol. 9, pp. 706-
710.
A Microscopical Study of the Nerve Cell
during Electrical Stimulation. Jour,
of Morph., Sept., 1894, Vol. 9, pp.
449-463.
The Daily Life of a Protozoan : A Study
in Comparative Psycho-Physiology.
(With H. A. Aikins.) Am. Jour, of
Psy., Jan., 1895, Vol. 6, pp. 524-533.
The Vivisection Question. Pop. Sci. Mo.,
Sept. and Oct., 1896, Vol. 49, pp. 614-
624, 771-785.
Experiments on the Physiology of Alcohol,
made under the Auspices of the Com-
mittee of Fifty. Ibid., March and
April, 1897, Vol. 50, pp. 594-603,
796-812.
Horticultural Interests in Kelation to
Public Education. Wor. Co. Hort.
Soc. Pep., 1898, pp. 62-81.
The Common Toad. Nature Study Leaf-
let. Biology Series, No. 1, 1898.
Worcester, Mass. 15 pp.
Our Common Birds. Biology Series, No.
2, 1899. Worcester, Mass. 34 pp.
FREDERICK H. HODGE: —
A.B., Boston University, 1894; A.M.,
ibid., 1899 ; Special Student, Bridgewater
Normal School, 1894-95; Professor of
Mathematics, J. B. Stetson University,
1895-96 ; Graduate Student in Mathe-
matics, University of Chicago, 1896-97 ;
Scholar in Mathematics, Clark Uni-
versity, 1897-98 ; Fellow, 1898-99 ;
Professor of Mathematics and History,
Bethel College, Russellville, Ky., 1899-.
THOMAS FRANKLIN HOLGATE : —
B.A., Victoria University, Toronto, 1884 ;
Mathematical Master, Albert College,
Belleville, Ont., 1884-90; M.A., Victoria
University, 1889 ; Fellow in Mathe-
matics, Clark University, 1890-93 ;
Ph.D., Clark University, 1893; In-
structor in Mathematics, Northwestern
University, 1893-94 ; Professor of Ap-
plied Mathematics, ibid., 1894- ; Member
of the American Mathematical Society.
Author of : —
On the Cone of the Second Order which
is Analogous to the Nine Point Conic.
Aiinals of Math., 1893, Vol. 7, pp.
73-76.
On Certain Ruled Surfaces of the Fourth
Order. Am. Jour, of Math., Oct.,
1893, Vol. 15, pp. 344-386. Addi-
tional Note on same. Ibid. (In
press.)
Correction of an Error in Salmon's " Ge-
ometry of Three Dimensions." Bull.
N. Y. Math. Soc, 1894, Vol. 3, p. 224.
A Geometrical Locus connected with a
System of Coaxial Circles. Bull. Am.
Math. Soc, Nov., 1897, 2d ser., Vol.
4, pp. 63-67.
A Second Locus connected with a System
of Coaxial Circles. Ibid., Dec, 1898,
Vol. 5, pp. 135-143.
Reye's "Lectures on the Geometry of
Position ' ' (translation) , Part I. Mac-
millan Company, New York, 1898.
248 pp.
RICHARD J. HOLLAND: —
B.A., Victoria College, Toronto, 1887 ;
Certificate Specialist in Science, Teachers'
Training Institute, Kingston, Ont., 1887-
88 ; Science Master, Morrisburg Collegiate
Institute, 1888-90 ; Graduate Student, Uni-
versity of Leipzig, 1890-93 ; Ph.D., Uni-
versity of Leipzig, 1893 ; Honorary
Fellow in Physics, Clark University,
1893-94 ; with Westinghouse Electric
Company, Pittsburg, Pa., 1894-95; with
J
504
Titles of
Electric Power Storage Company, N. Y.
City, April, 1895-.
Author of : —
Ueber die Aenderung der electrlschen
Leitfahigkeit einer Losung durch Zu-
satz von kleinen Mengen eines Nicht-
leiters. Wied. Annalen, Sept., 1893,
Vol. 50, pp. 261-292.
Ueber die electrische Leitfahigkeit von
Kupferchloridlosungen. Ibid., pp. 349-
360.
R. C. HOLLENBAUGH : —
A.B., Bucknell University, 1888; Princi-
pal, Cross Creek Academy, 1888-89 ;
A.M., Bucknell University, 1891; Ph.D.,
Wooster University, 1891 ; Graduate Stu-
dent, Johns Hopkins University, 1891-92 ;
Scholar in Psychology, Clark Univer-
sity, 1892.
Died July 6, 1893.
T^ILLIAM A. HOYT: —
A.B., Bates College, 1880; Principal
High School, Rockport, Me., 1881-82;
Principal Greeley Institute, Cumberland,
Me., 1882-83 ; Cornwall Heights School,
Cornwall, N. Y., 1883-86; A.M., Bates
College, 1884; Principal High School : Med-
way, Mass., 1886-88, North Brookfield,
Mass., 1888-92, Augusta, Me., 1892-93;
Scholar in Pedagogy, Clark Universi-
ty, 1893-94 ; Superintendent of Schools,
Brookfield, Mass. (District), 1894-.
Author of : —
The Love of Nature as the Root of Teach-
ing and Learning the Sciences. Peda-
gogical Seminary, Oct., 1894, Vol. 8,
pp. 61-86.
EDMUND B. HUEY: —
A.B., Lafayette College (First Honors
in Philosophy and Anglo-Saxon), 1895; In-
structor in Latin, Harry Hillman Academy,
Wilkesbarre, Pa., 1896-97; Scholar in
Psychology, Clark University, 1897-
98 ; Fellow, 1898-99; Professor of Psy-
chology, State Normal School, Moor-
head, Minn., 1899-.
Author of: —
Preliminary Experiments in the Physi-
ology and Psychology of Reading.
Am. Jour, of Psy., July, 1898, Vol. 9,
pp. 575-686.
D. D. HUGH : —
A.B., Dalhousie College, 1891; A.B.,
Harvard University, 1892 ; A.M., Cornell
University, 1893 ; Fellow in Psychol-
ogy, Clark University, 1895-96 ; Prin-
cipal of High School, La Junta, Col.,
1896-98; Professor of Psychology, Colo-
rado State Normal School, Greeley, Col.,
1898-99 ; Professor of Pedagogy and Eng-
lish, State Agricultural College, Logan,
Utah, 1899-.
Author of : —
Formal Education fiom the Standpoint of
Physiological Psychology. Pedagogi-
cal Seminary, April, 1898, Vol. 5,
pp. 599-605.
The Animism of Children. Northwestern
Monthly, June, 1899, Vol. 9, pp. 450-
453.
LORRAIN S. HULBURT: —
A.B., University of Wisconsin, 1883 ; A.M.,
ibid., 1888; Professor of Mathematics,
University of So. Dakota, 1887-91 ; Grad-
uate Student, University of Gottingen,
1889-90 ; Fellow in Mathematics, Clark
University, 1891-92 ; Instructor in
Mathematics, Johns Hopkins University,
1892-94 ; Ph.D., Johns Hopkins Univer-
sity, 1894 ; Associate in Mathematics,
ibid., 1894-97 ; Collegiate Professor of
Mathematics, ibid. , 1897- ; Member of
American Mathematical Society.
Author of : —
Theorems on the Number and Arrange-
ment of the Real Branches of Plane
Algebraic Curves. Am. Jour, of Math.,
July, 1892, Vol. 14, pp. 246-250.
Topology of Algebraic Curves. Bull, of
the N. Y. Math. Soc, 1892, Vol. 1,
pp. 197-202.
JOHN I. HUTCHINSON : —
A.B., Bates College, 1889; Scholar in
Mathematics, Clark University, 1890-
Puhlished Papers.
605
91 ; Fellow, 1891-92 ; Fellow in Mathe-
matics, University of Chicago, 1892-94 ;
Instructor in Mathematics, Cornell Uni-
versity, 1894- ; Ph.D., University of
Chicago, 1896 ; Member of American
Mathematical Society.
Author of : —
A Special Form of a Quartic Surface,
An7ials of Math., June, 1897, Vol. 2,
pp. 158-160.
On the Reduction of Hyperelliptic Func-
tions, (p = 2) to Elliptic Functions by a
Transformation of the Second Degree.
(Dissertation.) Gottingen, 1897. 40 pp.
Note on the Tetrahedroid. Bull, of the
Am. Math. Soc, April, 1898, 2d ser..
Vol. 4, pp. 327-329.
The Hessian of the Cubic Surface. Ibid. ,
March, 1899, 2d ser.. Vol. 5, pp. 282-
292.
The Asymptotic Lines of the Kummer
Surface. Ibid., July, 1899, 2d ser..
Vol. 5, pp. 465-467.
JOHN P. HYLAN : —
Student, Harvard University, 1891-95 ;
Fellow in Psychology, Clark Univer-
sity, 1895-97 ; Instructor in Psychology,
University of Illinois, 1897-98 ; Assistant
Professor, ibid., 1898-99 ; Member of
Executive Commission of Illinois Society
of Child Study.
Author of : —
Fluctuation of Attention. (Studies from
the Harvard Psy. Lab.) Psychological
Eeview, Jan., 1896, Vol. 3, pp. 56-63.
The Fluctuation of Attention. Psycho-
logical Beview, Monograph Supple-
ment, March, 1898, Vol. 2, No. 2.
78 pp.
MASSUO IKUTA: —
Student, University of Tokio, Japan, 1880-
85 ; University of Berlin, 1886 ; University
of Erlangen, 1887-88; Ph.D., University
of Erlangen, 1888 ; Consulting Chemist,
Tokio, Japan, 1889-90 ; Assistant in
Chemistry, Clark University, 1890-
92 ; Assistant in Chemistry, University of
Chicago, 1892-95 ; Instructor, ibid., 1895-.
Author of : —
Ueber die Einwirkung von Acetessigather
auf Chinone ; Synthese von Benzofur-
furan-Derivaten. Jour, fur praktische
Chemie, 1892, Vol. 45, pp. 65-83,
Metamidophenol and its Derivatives, Am.
Chem. Jour., Jan., 1893, Vol. 15, pp.
39-44.
JAMES EDMUND IVES : —
Jessup Student, Academy of Natural
Sciences, 1887-91 ; Assistant Curator,
ibid., 1887-93; Instructor in Physics,
Drexel Institute, 1893-97 ; Student in
Histology and Embryology, University of
Pennsylvania, 1888-89 ; Student in Mathe-
matics, ibid., 1893-95 ; Student in Physics,
Cavendish Laboratory, Cambridge, Eng.,
1896 ; Scholar in Physics, Clark Uni-
versity, 1897-98 ; Fellow, 1898-99.
Author of : —
On Two New Species of Starfishes. Proc.
Acad. Nat. Sci. of Phila., 1888, pp.
421-424.
Linguatula Diesingii, from the Sooty
Mangabey. Ibid., 1889, p. 31.
Variation in Ophiura Panamensis and
Ophiura teres. Ibid., 1889, pp. 76-
77.
On a New Genus and Two New Species of
Ophiurans. Ibid., 1889, pp. 143-145.
Catalogue of the Asteroidea and Ophiuroi-
dea in the Collection of the Academy
of Natural Sciences of Philadelphia.
Ibid., 1889, pp. 169-179.
Mimicry of the Environment in Ptero-
phryne histrio. Ibid., 1889, pp. 344-
345.
On Arenicola cristata and Its Allies.
Ibid., 1890, pp. 73-75.
Echinoderms from the Northern Coast of
Yucatan and the Harbor of Vera Cruz.
Ibid., 1890, pp. 317-340.
Crustacea from the Northern Coast of
Yucatan, the Harbor of Vera Cruz,
the West Coast of Florida and the
Bermuda Islands. Ibid., 1891, pp.
176-207.
Echinoderms and Arthropods from Japan.
Ibid., 1891, pp. 210-223.
606
Titles of
Echiuoderms from the Bahama Islands.
Ibid., 1891, pp. 337-341.
Reptiles and Batrachians from Northern
Yucatan and Mexico. Ibid., 1891, pp.
458-463.
Echinoderms and Crustaceans collected by
the West Greenland Expedition of 1891.
Ibid., 1891, pp. 479-481.
A New Species of Pycnogonum from Cali-
fornia. Ibid., 1892, pp. 142-144.
TILMON JENKINS : —
B.A., National Normal University, 1882 ;
Professor of Didactics, Salina, Kan.,
Normal University, 1883-85 ; Superin-
tendent of Schools, Kingman, Kan., 1885-
87 ; M. A. , National Normal University,
1891 ; Educational work in Colorado,
1887-96 ; Assistant State Superintendent
of Public Instruction, Colorado, 1894 ;
Superintendent of Schools, Santa F^, New
Mexico, 1896-97 ; Scholar in Pedagogy,
Clark University, 1897-98 ; Special
Student, University of Colorado, 1898-99.
GEORGE ELLSWORTH JOHNSON: —
A.B., Dartmouth College, 1887 ; A.M.,
ibid. 1891 ; Principal, Colebrook Acad-
emy, N. H., 1887-88 ; Principal of Schools,
Springfield, Vt., 1888-92 ; Student, Hart-
ford Theological Seminaiy, 1892-93;
Scholar in Pedagogy, Clark Univer-
sity, 1893-94 ; Fellow, 1894-95 ; Su-
perintendent of Schools, Andover, Mass.,
1895-.
Author of : —
Education by Plays and Games. Peda-
gogical Seminary, Oct., 1894, Vol. 3,
pp. 97-133.
Contribution to the Psychology and Peda-
gogy of Feeble-minded Children. Ibid.,
Oct., 1895, Vol. 3, pp. 246-301.
Play in Education. Northwestern Monthly,
July, 1897, Vol. 8, pp. 3-8.
Games and Play. First of Series of
Twelve Monographs on Social Work.
Issued by Lincoln House, Boston,
Mass., and The Commons, Chicago,
111. The Co-operative Press, Cam-
bridge, 1898. 22 pp.
Play in Physical Education. Am. Phys.
Ed. Rev., Sept., 1898, Vol. 3, pp. 179-
187.
The New Education. Address delivered
before the Andover Burns Club,
March 19, 1898. The Andover Press,
Andover, Mass., 1898. 15 pp.
HERBERT P. JOHNSON : —
A.B., Harvard University (with Honors
in Natural History), 1889; A.M., ibid.,
1890 ; Assistant in Biology, Williams Col-
lege, 1890-91 ; Fellow in Morphology,
Clark University, 1891-92 ; Fellow in
Morphology, University of Chicago, 1892-
94 ; Ph.D., University of Chicago, 1894 ;
Instructor in Biology, Des Moines Col-
lege, 1894 ; Assistant Professor of Zo-
ology, University of California, 1894- ;
Member of : American Society of Natu-
ralists ; California Academy of Sciences ;
San Francisco Microscopical Society.
Author of : —
Amitosis in the Embryonal Envelopes of
the Scorpion. Bull. 3Iuseum Com-
parative Zool., Harvard College, 1892,
Vol. 22, pp. 127-161 ; 3 pis.
A Contribution to the Morphology and
Biology of the Stentors. Jour, of
Morph., Aug., 1893, Vol. 8, pp. 468-
562 ; 4 pis.
The Plastogamy of Actinosphserium.
Ibid. April, 1894, Vol. 9, pp. 269-276.
A Preliminary Account of the Marine
Annelids of the Pacific Coast, with
Descriptions of New Species. Proc.
California Academy of Sciences, Third
Series. Zoology, 1897, Vol. 1, pp.
153-198 ; 6 pis.
EDWIN O. JORDAN: —
S.B., Massachusetts Institute of Tech-
nology, 1888 ; Chief Assistant Biologist,
Massachusetts State Board of Health,
1888-90 ; Lecturer in Biology, Massachu-
setts Institute of Technology, 1889-90 ;
Fellow^ in Morphology, Clark Uni-
versity, 1890-92; Ph.D., Clark Uni-
versity, 1892 ; Associate in Biology,
University of Chicago, 1892-93 ; Instructor
Published Papers.
507
in Biology, ihid.^ 1893-95 ; Assistant Pro-
fessor of Bacteriology, ibid., 1895-.
Author of : —
Phagocytosis and Immunity, Boston
Med. and Surg. Jour., 1890, Vol. 122,
p. 406.
Eecent Theories on the Function of the
White Blood-Cell. Technology Quar-
terly, 1890, Vol. 3, p. 170.
Certain Species of Bacteria observed in
Sewage. Beport of the Mass. State
Board of Health on Water Supply and
Sewage, 1889-90, Vol. 2, p. 821.
Investigations on Nitrification and the
Nitrifying Organisms. (With Mrs. Ellen
H. Richards.) Ibid., Vol. 2. Volume
on Water Supply and Sewage, 1890,
p. 865.
The Spermatophores of Diemyctylus.
Jour, of Morph., Sept., 1891, Vol. 5,
pp. 263-270.
The Cleavage of the Amphibian Ovum.
(With A. C. Eycleshymer. ) Anat.
Anzeiger, Sept. 15, 1892, Vol. 7,
pp. 622-624.
The Habits and Development of the Newt.
Jour, of Morph., May, 1893, Vol. 8,
pp. 270-366, 5 Plates.
On the Cleavage of Amphibian Ova. (With
A. C. Eycleshymer.) Ibid., Sept.,
1894, Vol. 9, pp. 407-416, 1 Plate.
The Identification of the Typhoid Fever
Bacillus. Jour. Am. Med. Ass''n,
Dec. 22, 1894.
On Some Conditions affecting the Be-
havior of the Typhoid Bacillus in
Water. Medical News, Sept. 28, 1895.
The "Inheritance" of Certain Bacterial
Diseases. Chicago Med. Becorder,
Aug., 1898, Vol. 15, p. 82.
The Production of Fluorescent Pigment by
Bacteria. Botanical Gazette, Jan.,
1899, Vol. 27, p. 19.
Translation of the Principles of Bacteri-
ology by Professor F. Hueppe. Open
Court Publishing Co., Chicago. 467 pp.
The Death-rate from Diphtheria in the
Large Cities of the United States.
Philadelphia Med. Jour., Feb. 18,
1899.
F. C. KENYON: —
B.Sc, University of Nebraska, 1892 ; In-
structor in Zoology, ibid., 1891-93 ; Assist-
ant and Fellow in Biology, Tufts College,
1893-95 ; A.M. and Ph.D., Tufts College,
1895 ; Fellow in Biology, Clark Uni-
versity, 1895-96 ; Fellow, American
Association for the Advancement of
Science ; Member of : American Morpho-
logical Society, American Society of
Naturalists, National Geographic Society.
Author of : —
The Morphology and Classification of the
Pauropoda. Tufts College Studies,
1895.
In the Region of the New Fossil ; Dse-
mouelix. American Naturalist, 1895.
Formal as a Preserving Agent. Ibid.,
1895.
The Meaning and Structure of the So-
called Mushroom Bodies of the Hexa-
pod Brain. Ibid., 1896.
The Brain of the Bee. Jour. Comp. Neu-
rology, 1896.
The Optic Lobe of the Bee's Brain in the
Light of Recent Neurological Methods.
1897.
Delarvation. American Naturalist, 1897.
The Chartognaths of American Waters.
Ibid.
The Regeneration of an Antenna-like
Structure instead of an Eye. Ibid.
The Regeneration of the Lens of the Eye
of Tritan. Ibid.
Formol or Formalin. Ibid.
Effect of Lithium Chloride upon the De-
velopment of the Frog and Toad Egg.
Ibid., 1896.
The Terminology of the Neurocytes,
Science, 1897.
HERBERT G. KEPPEL: —
A.B., Hope College, Holland, Mich.,
1889 ; Instructor in Mathematics, North-
western Classical Academy, Orange City,
la., 1891-92; Scholar in Mathematics,
Clark University, 1892-93; Fellow,
1893-95 ; Instructor in Mathematics,
Academy of Northwestern University,
Evanston, 111., 1895-96; Instructor in
508
Titles of
Mathematics, Northwestern University,
Evanston, 111., 1896- ; Member of the
American Mathematical Society ; Member
of Het Wiskundig Genootschap, Amster-
dam.
E. A. KIRKPATRICK : —
B.Sc, Iowa Agricultural College, 1887;
M.Ph., lUd., 1889; Scholar in Psy-
chology, Clark University, 1889-90 ;
Fellow, 1890-91 ; Professor of Psy-
chology and Pedagogy, State Normal
School, Winona, Minn., 1892-97 ; Pro-
fessor of Psychology and Child Study,
State Normal School, Fitchburg, Mass.,
1898- ; Member of American Psychologi-
cal Association.
Author of : —
Observations on College Seniors and Elec-
tives in Psychological Subjects. Am.
Jour, of Psy., April, 1890, Vol. 3, pp.
168-173.
Number of Words in an Ordinary Vocabu-
lary. Science, Aug, 21, 1891, Vol. 18,
pp. 107-108.
How Children learn to Talk. Ibid.,
Sept. 25, 1891, Vol. 18, pp. 175-176.
Mental Images. Ibid. , Oct. 27, 1893, Vol,
22, pp. 227-230.
An Experimental Study of Memory. Psy-
chological Eeview, Nov., 1894, Vol. 1,
pp. 602-609.
Inductive Psychology: An Introduction
to the Study of Mental Phenomena.
E. L. Kellogg & Co., New York, 1895.
208 pp.
Child Study in the Training of Teachers.
Review of Bevieios, Dec, 1896, Vol.
14, pp. 686-692.
Handbook of Minnesota Child-Study As-
sociation. James and Kroeger, Wi-
nona, Minn., 1897. 60 pp.
Continuous Sessions of Schools. Review
of Reviews, July, 1897, Vol. 16, pp.
190-191.
Play as a Factor in Social and Educa-
tional Reforms. Ibid., Aug., 1899,
Vol. 20, pp. 192-196.
Children's Reading. Northwestern Month-
ly, June, 1898, Vol. 8. pp. 651-654;
Dec, 1898, Jan., March-April, 1899,
Vol. 9, pp. 188-191, 229-2.33, 338-342.
Learning Voluntary Movements. School
and Home Education, March, 1899,
Vol. 18, pp. 337-344.
The Development of Voluntary Move-
ment. Psychological Review, May,
1899, Vol. 6, pp. 275-281.
MILTON S. KISTLER: —
Graduate, West Chester, Pa., State Nor-
mal School, 1888 ; Principal, High School,
Honey Brook, Pa., 1888-89; Principal,
Blaine Normal Institute, Pa., 1889-90 ;
Ph.B., Dickinson College, 1894; A.M.,
ibid., 1897 ; Professor of Latin and Eng-
lish, Edinboro, Pa., State Normal School,
1894-97 ; Scholar in Pedagogy, Clark
University, 1897-98 ; Teacher, N. Y.
City Schools, 1898-.
Author of : —
John Knox's Services to Education. Edu-
cation, Boston, Mass., Oct. 1898, Vol.
19, pp. 105-116.
LINUS "W. KLINE: —
Student, University of Virginia, 1886-87 ;
L.I., Peabody Normal College, 1889;
Principal, Hamilton Grammar School,
Houston, Texas, 1891-93 ; B.S., Harvard
University, 1896 ; Scholar in Psychol-
ogy, Clark University, 1896-97 ; Fel-
low, 1897-98 ; Ph.D., Clark Univer-
sity, 1898 ; Honorary Fellow and
Assistant in Psychology, 1898-99 ;
Professor of Psychology and Pedagogy,
State Normal School, Mankato, Minn.,
1899-.
Author of : —
Truancy as Related to the Migrating In-
stinct. Pedagogical Seminary, Jan.,
1898, Vol. 5, pp. 381-420.
The Migratory Impulse vs. Love of Home.
Am. Jour, of Psy., Oct. 1898, Vol. 10,
pp. 1-81.
Methods in Animal Psychology. Ibid.,
Jan., 1899, Vol. 10, pp. 2-56-279.
Suggestions toward a Laboratory Course
in Comparative Psychology. Ibid.,
April, 1899, Vol. 10, pp. 399-430.
Published Pajyers.
509
The Psychology of Ownership. (With C.
J. France.) Pedagogical Seminary.
(In press.)
"WILLIAM O. KROHN: —
A.B. , Western College, 1887 ; Ph.D.,
Yale University, 1889 ; Instructor in Phi-
losophy and Psychology, Western Eeserve
University, 1889-91 ; Inspecting Psycho-
logical Laboratories in German Universi-
ties, July, 1891-Feb. 1892 ; Fellow in
Psychology, Clark University, March-
June, 1892 ; Professor of Psychology,
University of Illinois, 1892-97 ; Psychol-
ogist, Illinois Eastern Hospital, Kanka-
kee, 111., 1897- ; Editor of Child-Study
Monthly.
Author of : —
Facilities in Experimental Psychology at
the Various German Universities. Am.
Jour, of Psy., Aug., 1892, Vol. 4, pp.
585-594.
Pseudo-Chromesthesia, or the Association
of Colors vpith Words, Letters, and
Sounds. Ibid., Oct., 1892, Vol. 5, pp.
20-41.
An Experimental Study of Simultaneous
Stimulation of the Sense of Touch,
Jour, of Nervoxis and Mental Disease,
March, 1893 ; N. S., Vol. 18, pp. 169-
184.
Practical Lessons in Psychology. The
Werner Co., Chicago and New York.
400 pp.
Laboratory Psychology as applied to the
Study of Insanity. Psychiater, Vol. 1,
No. 1.
Minor Mental Abnormalities in Children
as occasioned by Certain Erroneous
School Methods. Proc. N. E. A. , 1898,
pp. 162-172.
ELLSWORTH G. LANCASTER: —
B.A., Amherst College, 1885; M.A.,
ibid. 1888 ; Teacher, Elocution and Phys-
ical Culture, Williston Seminary, East-
hampton, Mass., 1885-86; Student,
Auburn Theological Seminary, 1886-87 ;
Teacher, Physical Culture, Latin, and
German, Morgan Park Military Academy,
1887-88 ; Student, Chicago Baptist Semi-
nary, 1887-88 ; Student, Andover Theo-
logical Seminary, 1888-89; B.D., ibid.,
1889 ; Pastor, Congregational Church,
Ashby, Mass., 1889-90; Principal, South-
ern Kansas Academy, 1890-95 ; Scholar
in Psychology, Clark University,
1895-96; Fellow, 1896-97; Ph.D.,
Clark University, 1897 ; Instructor in
Philosophy and Pedagogy, and President's
Assistant, Colorado College, 1897-98 ;
Assistant Professor, ibid., 1898-.
Author of : —
Psychology and Pedagogy of Adolescence.
Pedagogical Seminary, July, 1897,
Vol. 5, pp. 61-128.
Warming Up. Colorado College Studies,
Nov., 1898, Vol. 7, pp. 16-29.
JAMES STEPHEN LEMON: —
B.A., Wesleyan University, 1863 ; M.A.,
ibid., 1866; Principal of High School,
Brownville, New York, 1862; Assistant on
McClintock and Strong's Cyclopaedia of
Biblical, Theological, and Ecclesiastical
Literature, 1859-61 ; Assistant on Strong's
Concordance of the Bible, 1859-65 ; Pro-
fessor of Physics, Marion, N. Y., Institute,
1863-65 ; Principal, Almond Collegiate In-
stitute, 1866 ; Principal, Macedon, N. Y.,
Academy, 1867; Rector, Protestant Epis-
copal Church, 1877-; Scholar in Psy-
chology, Clark University, 1891-93;
Student in Psychology, 1893-94 ; Lec-
turer in Psychophysics, Columbian Uni-
versity, Washington, D. C, 1894-; Ph.D.,
Columbian University, 1896 ; Lecturer
in Physiological Psychology, Howard
University, 1897- ; Member Society for
Philosophical Inquiry, Washington, D. C;
Member American Anthropological So-
ciety.
Author of: —
Signalling by Flashlights. Troy, Pa. ,1874.
10 pp.
The Body Considered in Its Relation to the
Intellectual Processes. Union Springs,
N. Y., 1875.
Lists of Questions to be Asked as to
Defectives, etc., admitted to Cottage
510
Titles of
Hospitals for Children. Athol, Mass.
7 pp.
Psychic Effects of the "Weather. Am. Jour.
ofFsy., Jan., 1894, Vol. 6, pp. 277-311.
Requirements Demanded for Official Rec-
ognition as Teachers. Templeton Press,
Templeton, Mass., 1898. 13 pp.
The Skin considered as an Organ of Sensa-
tion. Journal Publishing Co., Gardner,
Mass., 1898. 77 pp.
The Weather Idea. Journal Publishing
Co., Gardner, Mass., 1899. 60 pp.
Numerous reviews and articles in Healthy
Home, Cottager, and National Tribune,
1880-.
JAMES E. LEROSSIGNOL : —
B.A.,McGill University, 1888; Teacher in
Berthelet School, Montreal, 1888-89 ; Stu-
dent in Philosophy, University of Leipzig,
1889-92; Ph.D., University of Leipzig,
1892; Fellow in Psychology, Clark Uni-
versity, May-July, 1892 ; Professor of
Psychology and Ethics, Ohio University,
Athens, 1892-94 ; Professor of History and
Political Economy, University of Denver,
1894- ; Member of : American Economic
Association, American Academy of Polit-
ical and Social Science, American His-
torical Association.
Author of : —
The Ethical Philosophy of Samuel Clarke.
G. Kreysing, Leipzig, 1892. 97 pp.
The Training of Animals. Am. Jour, of
Psy., Nov., 1892, Vol. 5, pp. 205-213.
Malevolence in the Lower Animals. Ohio
University Bulletin, Sept., 1893, Vol. 1,
pp. 1-9.
The Expression of Anger. Transactions
of the Ohio College Association, 1894,
pp. 40-49.
Spinoza as a Biblical Critic. Canadian
Methodist Beview, Jan.-Feb., 1895, Vol.
7, pp. 52-60.
JAMES H. LEUBA : —
B.S., University of Neuch§,tel, Switzer-
land, 1886 ; Ph.B., Ursiuus College, 1888 ;
Instructor in French and German, St.
Mark's School, Southborough, Mass.,
1891-92 ; Scholar in Psychology, Clark
University, 1892-93; Fellow, 1893-
95; Ph.D., Clark University, 1895;
Professor of Psychology and Pedagogy,
Bryn Mawr College, 1897- ; Universities
of Leipzig, Gottingen, Heidelberg, and
Paris, 1897-98 ; Member of the American
Psychological Association.
Author of : —
A New Instrument for Weber's Law ; with
Indications of a Law of Sense Memory.
Am. Jour, o/ Psy., April, 1893, Vol. 5,
pp. 370-384.
National Destruction and Construction in
Prance as seen in Modern Literature
and in the Neo-Christian Movement.
Ibid., July, 1893, Vol. 5, pp. 496-539.
A Study in the Psychology of Religious
Phenomena. Ibid., April, 1896, Vol.
7, pp. 309-385.
The Psycho-Physiology of the Moral Im-
perative. Ibid., July, 1897, Vol. 8, pp.
528-559.
On the Validity of the Griesbach Method
of Determining Fatigue. Psychologi-
cal Beview, Nov., 1899, Vol. 6, pp.
573-598.
FRANK R. LILLIE: —
Assistant in Biology, University of Toronto,
1890-91; B.A., ibid., 1891; Fellow in
Morphology, Clark University, 1891-
92; Fellow in Zoology, University of Chi-
cago, 1892-93 ; Reader in Embryology,
ibid., 1893-94; Ph.D., University of Chi-
cago, 1894; Instructor in Zoology, Uni-
versity of Michigan, 1894-99; Professor
of Biology,'Vassar College, 1899-; Member
American Society of Morphologists; Mem-
ber Michigan Academy of Sciences.
Author of : —
Preliminary Account of the Embryology
of Unio complauata. Jour, of Morph.,
Aug., 1893, Vol. 8, pp. 569-578, 1 plate.
The Embryology of the Unionidte, a Study
in Cell-Lineage. Ibid., Jan., 1895 ; Vol.
10, pp. 1-100, 6 plates.
On the Smallest Parts of Stentor Capable
of Regeneration. A Contribution on
Published Papers.
511
the Limit of Divisibility of Living Mat-
ter. Ibid. , May, 1896, Vol. 12, pp. 239-
249.
On the Effect of Temperature on the De-
velopment of Animals. (With F. P.
Knowlton.) Zoological Bulletin., Dec,
1897, Vol. 1, pp. 179-193.
On the Origin of the Centres of the First
Cleavage Spindle in Unio complanata.
Science, March 5, 1897, N. S., Vol. 5,
pp. 389-390.
Centrosome and Sphere in the Egg of Unio.
Zoological Bulletin, May, 1898, Vol. 1,
pp. 265-274.
Hertwig's "Zelle und Gewebe," Vol. 2.
Science, Oct. 14, 1898, N. S.,Vol. 8, pp.
517-520.
Adaptation in Cleavage. "Woods Holl
Biological Lectures, 1898. Ginn & Co.,
Boston. (In press.)
ERNEST H. LINDLEY: —
A. B., Indiana University, 1893; AM.,ihid.,
1894 ; Instructor in Philosophy, iftid., 1893-
95 ; Fellow in Psychology, Clark
University, 1895-97; Ph.D., Clark
University, 1897 ; Universities of Jena,
Leipzig, and Heidelberg, 1897-98 ; Asso-
ciate Professor of Psychology, Indiana
University, 1898- ; Member American
Psychological Association.
Author of : —
A Preliminary Study of Some of the Mo-
tor Phenomena of Mental Effort. Am.
Jour, of Psy., July, 1896, Vol. 7, pp.
491-517.
Some Mental Automatisms. (With G. E.
Partridge.) Pedagogical Seminary,
July, 1897, Vol. 5, pp. 41-60.
A Study of Puzzles with Special Reference
to the Psychology of Mental Adapta-
tion. Am. Jour, of Psy., July, 1897,
Vol. 8, pp. 431-493.
Ueber Arbeit und Ruhe. Psychologische
Arbeiten, herausg. von E. Kraepelin.
Heidelberg. (In press.)
C. E. LINEB ARGER : —
A.B. , Northwestern University, 1888 ;
Student, Chicago Medical College, 1888-
89 ; Student, Universities of Tubingen and
Paris, 1889-91 ; Fellow in Chemistry,
Clark University, 1891 ; Instructor in
Chemistry, North Division High School,
Chicago, 1891-93 ; Student, University of
Gottiugen, 1893-94 ; Student, School of
Mines, Paris, 1894 ; Instructor in Chem-
istry and Physics, South Division High
School, Chicago, 1894-96 ; Instructor in
Chemistry and Physics, Lake View High
School, Chicago, 1896-99; Member of:
American Chemical Society, Chemical
Society of Paris, German Electro-
chemical Society.
Author of: —
An Examination of Fusel Oil. (With
J. H. Long.) Jour, of Anal. Chem.,
1890, Vol. 4, p. 5.
Sur I'Hydroxanthranol. Bull. d. I. Soc.
Chimique, 1891, Vol. 6, p. 92.
The Action of Benzene on Benzal Chloride
in the Presence of Aluminium Chloride.
Am. Chem. Jour., 1891, Vol. 13, p. 556.
The Reaction between Triphenylmethane
and Chloroform in the Presence of
Aluminium Chloride. Ibid., p. 553.
On Disulphotetraphenylene. Jour. Am.
Chem. Soc, Vol. 13, p. 270.
A Rapid Dialyzer. Jour, of Anal. Chem.,
1892, Vol. 6, p. 91.
On the Nature of Colloid Solutions. Am.
Jour, of Sci., 1892, Vol. 43, p. 218.
The Molecular Masses of Dextrine and
Gum Arabic as determined by their
Osmotic Pressures. Ibid., p. 428.
On the Formation of Layers in Solutions
of Salts in Mixtures of Water and
Organic Liquids. Am. Chem. Jour.,
1892, Vol. 14, p. 380.
On the Relations between the Surface
Tensions of Liquids and their Chemi-
cal Constitution. A7n. Jour, of Sci.,
1892, Vol. 44, p. 83.
On the Influence of the Concentration of
the Ions on the Intensity of Color of
Solutions of Salts in Water. Ibid., p.
416.
The Dissociation of Salts into their Ions
by Water of Crystallization. Am.
Chem. Jour., 1892, Vol. 14, p. 604.
512
Titles of
On the Application of the Friedel-Craffts
Reaction to Syntheses in the Anthra-
cene Series. Ibid., p. 602.
On the Preparation and Constitution of
Paraanthracene. Ibid., p. 597.
A Definition of Solutions. Science, 1892,
Vol. 20, p. 352.
The Solubility of Triphenylmethane in
Benzene. Am. Chem. Jour., 1893,
Vol. 15, p. 4.5.
The Hydrates of Manganous Sulphate.
Ibid., 1893, Vol. 15, p. 225.
On the Existence of Double Salts in Solu-
tion. Ibid., 1893, Vol. 15, p. 337.
An Isothermal Curve of Solubility of
Mercuric and Sodium Chlorides in
Acetic Ether. Ibid., 1894, Vol. 16,
p. 215.
The Benzoyl Halogen Amides. Ibid.,
1894, Vol. 16, p. 218.
Ueber die Bestimmung kleiner Dissocia-
tionsspannungen speciell Krystallwas-
serhaltiger Salze. Zeits. f. phys.
Chemie, 1894, Vol. 13, p. 500.
Some Modifications of Beckmann's Ebul-
lioscopic Apparatus. Chemical Neios,
1894, Vol. 69, p. 279.
The Boiling Points of Dilute Solutions of
"Water in Alcohol and in Ether. Ibid. ,
p. 613.
On the Application of the Schroeder-Le-
Chatelier Law of Solubility to Solutions
of Salts in Organic Liquids. Am.
Jour, of Sci., 1895, Vol. 49, p. 48.
The Combination of Sulphur with Iodine.
Am. Chem. Jour., 1895, Vol. 17, p.
33.
On Some Experiments in the Anthracene
Series. Jour. Ain. Chem. Soc, 1895,
Vol. 17, p. 351.
On the .Reaction between Zinc Sulphate
and Potassium Hydroxide. Ibid., p.
358.
On Some Relations between Temperature,
Pressure, and Latent Heat of Vapor-
ization. Am. Jour, of Sci., 1895, Vol.
49, p. 380.
On the Vapor Tensions of Mixtures of
Volatile Liquids. Jour. Am. Chem.
Soc, 1895, Vol. 17, p. 580.
On the Formation of Layers in Mixtures
of Acetic Acid and Benzene. Ibid. , p.
932.
On the Heat Effect of mixing Liquids.
Physical Review, 1896, Vol. 3, p. 418.
On the Specific Gravities of Mixtures of
Normal Liquids. Am. Chem. Jour.,
1896, Vol. 18, p. 428.
A Rapid Method of determining the Mo-
lecular Masses of Liquids by Means of
their Surface Tensions. Jour. Am.
Chem. Soc, 1896, Vol. 18, p. 514.
On the Reaction between Carbon Tetra-
chloride and the Oxides of Niobium
and Tantalum. (In collaboration with
M. Delafontaine.) Ibid., p. 32.
Ueber die Dielektricitatskonstanten von
Fliissigkeitsgemischen. Zeitschr. f.
phys. Chemie, 1896, Vol. 20, p. 131.
An Apparatus for the Rapid Determina-
tion of the Surface Tensions of Liquids.
Am. Jour. Sci., 1896, Vol. 2, p. 108.
On the Surface Tension of Mixtures of
Normal Liquids. Ibid., p. 226.
On the Viscosity of Mixtures of Liquids.
Ibid., p. 331.
The Phase Rule. By Wilder D. Bancroft.
Review. Monist, 1897, Vol. 7, p. 634.
Grundziige einer thermodynamischen
Theorie elektrochemischer Krafte. By
Alfred H. Bucherer. Review. Ibid.,
p. 635.
The Phase Rule. By "Wilder D. Bancroft.
Review. Jour. Am. Chem. Soc, 1897,
Vol. 19, p. 767.
The Surface Tensions of Aqueous Solu-
tions of Oxalic, Tartaric, and Citric
Acids. Ibid., 1898, Vol. 20, p. 128.
An Outline of the Theory of Solution and
its Results. By J. Livingston R. Mor-
gan. Review. Ibid., 1898,Yo\. 20, p.
153.
The Principles of Mathematical Chemis-
try. By J. Livingston R. Morgan.
Review. Ibid., 1898, Vol. 20, p. 155.
On the Speed of Coagulation of Colloid
Solutions. Ibid., 1898, Vol. 20, p.
375.
Text-book of Physical Chemistry. By
Clarence L. Speyers. Review. Ibid.,
1898, Vol. 20, p. 389.
On a Balance for Use in Courses in Ele-
Published Papers.
513
mentary Chemistry. 76id., 1899, "Vol.
21, p. 31.
The Surface Tension of Aqueous Solutions
of Alkaline Chlorides. Ihid., 1899,
Vol. 21, p. 327.
A Simple Voluminometer. Ibid., 1899,
Vol. 21, p. 435.
The Elements of Differential and Integral
Calculus. (In collaboration with J. W.
A. Young.) 1899, D. Appleton & Co.
SIDNEY J. LOCHNER: —
A.B., Union College, 1890; A.M., ibid.,
1892 ; First Assistant in Astronomy, Dud-
ley Observatory, Albany, N. Y., 1889-92 ;
Fellow in Physics, Clark University,
Oct., 1892-May, 1893 ; Assistant, Har-
vard Observatory, 1893 ; Admitted as At-
torney at Law, Detroit, Mich., Dec,
1893; Professor of Physics and Mathe-
matics, Delaware Literary Institute,
Franklin, N. Y., 1894-.
Author of: —
On the Elongation Produced in Soft Iron
by Magnetism. Fhil. Magazine, Dec,
1893, Fifth Series, Vol. 36, pp. 498-
507.
Modern Scientific Investigations. Union
College Concordensis, 1894.
WILLIAM E. LOCKWOOD: —
Ph.B., Sheffield Scientific School, Yale
University, 1883; M.D., ibid., 1885 ; in-
structor in Chemistry, ibid., 1885-86 ; In-
structor and Demonstrator in Physiology,
ibid., 1887-91 ; Fellow in Physiology,
Clark University, 1891-92.
Died at Redlands, Cal., June 23, 1897.
Author of : —
The New Haven Water Supply : A Criti-
cism of the Results of Analyses of
this Water, as given by Dr. Arthur J.
Wolff, in the Report of the Connecticut
State Board of Health for 1885. (With
Herbert E. Smith, M.D.) New Haven.
6 pp.
Report of the Analyses of One Hundred
and Ten Well Waters, collected in
New Haven. (With Herbert E. Smith,
M.D.) Report of the Connecticut
State Board of Health, 1886, pp. 259-
269.
Some Hints for the Physician concerning
Urinary Analysis. 3Iedical Register,
Philadelphia, March 19, 1887, Vol. 1,
pp. 169-174.
MORRIS LOEB : —
A.B., Harvard University, 1883; Ph.D.,
University of Berlin, 1887 ; Assistant to
Professor Wolcott Gibbs, 1888-89 ; Do-
cent in Physical Chemistry, Clark
University, 1889-91 ; Professor of
Chemistry, New York University, N. Y.
City, 1891-.
Author of : —
Ueber die Einwirkung von Phosgen auf
Aethenyldiphenyldiamin, Ber. d.
deut. chem. Gesellschaft, Aug., 1885,
Vol. 18, pp. 2427-2428.
Ueber Amidinderivate. Ibid. , Aug. , 1886,
Vol. 19, pp. 2340-2444.
Das Phosgen und seine Abkommlinge.
Berlin, March 15, 1887. 51 pp.
The Molecular Weight of Iodine in its
Solutions. Jour, of Chem. Soc,
Trans., 1888, Vol. 53, pp. 805-812.
Also Zeits. f. physikalische Chemie,
July, 1888, Vol. 2, pp. 606-612.
The Use of Aniline for Absorbing Cyano-
gen in Gas Analysis. Jour, of Chem.
Soc, Trans., 1888, Vol. 53, pp. 812-
814.
The Rates of Transference and the Con-
ducting Power of Certain Silver Salts.
(With W. Nernst. ) Am. Chem. Jour. ,
Feb., 1889, Vol. 11, pp. 106-121. Also
Zeits. f. physikalische Chemie, Nov.,
1888, Vol. 2, pp. 948-963.
Is Chemical Action Affected by Magnet-
ism? Am. C/iejn. Jbwr., March, 1891,
Vol. 13, pp. 145-153.
WARREN P. LOMBARD : —
A.B., Harvard University, 1878; M.D.,
Harvard Medical School, 1881 ; University
of Leipzig, 1882-85; Assistant in Physi-
ology, College of Physicians and Surgeons,
New York City, 1888-89 ; Assistant Pro-
fessor of Physiology, Clark Univer-
514
Titles of
sity, 1889-92 ; Professor of Physiology,
University of Michigan, 1892- ; Member
American Physiological Society.
Author of : —
Beitrage zur Theorie der Warmeempfin-
dung. Vorlaufige Mitteilung. Cen-
tralbl. f. d. Med. JVissensch., 1883,
Vol. 21, pp. 577-579.
Die raumliche und zeitliche Auf einander-
folge reflectorisch contrahirter Mus-
keln. Ai'ch. f. Anat. u. Physiologie,
Physiol. Abthl., 1885, pp. 408-489.
Is the "Knee-jerk" a Reflex Act? Am.
Jour, of Med. Sciences, Jan., 1887.
The Variations of the Normal ' ' Knee-
jerk." Am. Jour, of Fsy., Nov., 1887,
Vol. 1, pp. 5-71.
Die Variationen des normalen Kniestosses.
Arch, f Anat. u. Physiologie., Suppl.
Band, 1889, pp. 292-335, 10 pis.
On the Nature of the " Knee-jerk." Jour,
of Physiology, Feb., 1889, Vol. 10, pp.
122-148.
The Effect of Fatigue on Voluntary Mus-
cular Contraction. Am. Jour, of Psy.,
Jan., 1890, Vol. 3, pp. 24-42.
Effet de la fatigue sur la contraction mus-
culaire volontaire. Arch. Ital. de Biol-
ogie, 1890, Vol. 13, pp. 371-381.
Alterations in the Strength which occur
during Fatiguing Voluntary Muscular
Work. Jour, of Physiology, Jan.,
1893, Vol. 1-4, pp. 97-124.
General Physiology of Miiscle and Nerve.
Chapter 11., Howell's ^?)i. Text Book
of Physiology. W. B. Saunders, Phila-
delphia, 1896. pp. 32-151.
PRANK H. LOUD : —
A.B., Amherst College, 1873 ; Walker In-
structor in Mathematics, ibid., 1873-76;
Professor of Mathematics, Colorado Col-
lege, 1877- ; Director of State Weather
Service, Colorado, 1889-90 ; Scholar
in Mathematics, Clark University,
1890-91.
Author of : —
A Rigorous Elementary Proof of the
Binominal Theorem. Col. College
Studies, 1890, pp. 7-15.
On Certain Cubic Curves. Ibid., 1890, p.
16.
The Elliptic Functions Defined Indepen-
dently of the Calculus. Ibid., 1891,
pp. 48-81.
ELWYN N. LOVEWELL: —
Ph.B., University of Vermont, 1898
(Double Honors) ; Scholar in Mathe-
matics, Clark University, 1898-99.
GEORGE "W. A. LUCKEY : —
Teacher in Public Schools of Indiana,
1874-78 ; Superintendent of Schools,
Adams Co., Ind., 1878-82 ; Superinten-
dent of Schools, Decatur, Ind., 1882-
87 ; Supervising Principal, Ontario, Cal.,
1888-92 ; Non-Resident Student, Univer-
sity of City of New York, 1889-92 ; Stu-
dent in Pedagogy and Psychology, Leland
Stanford Jr. University, 1892-94 ; A.B.,
ibid., 1894; Fellow in Psychology,
Clark University, 1894-95 ; Associate
Professor of Pedagogy, University of Ne-
braska, 1895-96 ; Professor of Pedagogy,
ibid., 1896- ; Editor of the Child Study
Department, Northwestern Monthly, 1895-
99.
Author of : —
Comparative Observations on the Indirect
Color Range of Children, Adults, and
Adults Trained in Color. Am. Jour,
of Psy., Jan., 1895, Vol. 6, pp. 489-
504.
Some Recent Studies of Pain. Ibid., Oct. ,
1895, Vol. 7, pp. 108-123.
Child Study in its Effects upon the
Teacher. Child Study Monthly, Feb.,
1896, Vol. 1, pp. 230-247.
Children's Interests. Northw. 3Ionthly,
1896-97, Vol. 7, pp. 67, 96, 133, 156,
221, 245, 306, and 335.
Practical Results Obtained through the
Study of Children's Interests. Proc.
N. E. A., 1897, pp. 284-288 ; also Jour.
of Ed., Apr. 8, 1897, Vol. 45, p. 222.
Lines of Child Study for the Teacher.
Educational Beview, Nov., 1897, Vol.
14, pp. 340-347 ; also Proc. N. E. A.,
1897, pp. 826-833.
Published Papers.
515
A Brief Survey of Child Study. North-
western Jour, of Ed., July, 1896, Vol.
7, pp. 2-9.
Methods Pursued in Child Study. Ibid.,
pp. 33-35.
The Best Works on Child Study. Ibid.,
pp. 48-53.
The Development of Moral Character.
Proc. iV. E. A., 1899.
HERMAN T. LUKENS : —
A.B., University of Pennsylvania, 1885 j
A.M., ibid., 1888 ; Student in Halle, Jena,
and Berlin, 1888-91 ; Ph.D., University of
Jena, 1891 ; Instructor in Biology, N. W.
Division High School, Chicago, 1891-94 ;
Honorary Fellow in Psychology,
Clark University, 1894-95 ; Docent
in Pedagogy, 1895- ; Lecturer in
Education, Bryn Mawr College, 1896-97 ;
Visit to Europe to study Education,
1897-98 ; Head Training Teacher, S. W.
State Normal School, California, Pa.,
1898-.
Author of : —
Herbart's Psychological Basis of Teach-
ing. Part II of Th. B. Noss's Outlines
of Psychology and Pedagogy, Pitts-
burg, 1890.
Die Vorstellungsreihen und ihre padago-
gische Bedeutung. Giitersloh, Prussia,
1892.
A Portion of the Translation of Lange's
Apperception. Edited by Charles De
Garmo. D. C. Heath & Co., Boston,
1893. 279 pp.
The Connection between Thought and
Memory. Based on Dorpfeld's Den-
ken und Geddchtnis. D. C. Heath &
Co., Boston, 1895. 179 pp.
The Correlation of Studies. Educational
Beview, Nov., 1895, Vol. 10, pp. 364-
383.
Correlation. Jour, of Ed., May 9 and
June 20, 1895, Vol. 41, pp. 311-312 ;
Vol. 42, p. 15.
A Point of Difference between Race and
Individual Development. Second Her-
bartian Yearbook, 1896.
Preliminary Report on the Learning of
Language. Pedagogical Seminary,
June, 1896, Vol. 3, pp. 424-460.
A Study of Children's Drawings in the
Early Years. Ibid., Oct. 1896, Vol.
4, pp. 79-110.
Child Study for Superintendents. Edu-
cational Beview, Feb., 1897, Vol. 13,
pp. 105-120.
Honorary Degrees in the United States.
Ibid., June, 1897, Vol. 14, pp. 8-16.
Language Defects. Northw. Monthly,
July, 1897, Vol. 8, pp. 39-44.
The Vital Question in the Curriculum.
Education, Sept., 1897, Vol. 18, pp.
19-29.
Die Entwickelungsstufen beim Zeichnen.
Kinderfehler, Dec, 1897, Vol. 2, pp.
166-170.
Malendes Zeichnen. Aus dem pad.
Univ.- Seminar Jena, VII., 1897.
The School Fatigue Question in Ger-
many. Educational Beview, March,
1898, Vol. 15, pp. 246-254.
The Method of Suggestion in the Cure of
Faults. Northwestern Monthly, May,
1898, Vol. 8, pp. 592-595.
The School and Real Life. iV. Y. School
Jour., Oct. 1, 1898, Vol. 57, pp. 277-
279.
Notes Abroad. Pedagogical Seminary,
Oct., 1898, Vol. 6, pp. 114-125.
A School-Garden in Thuringia. Educa-
tional Beview, March, 1899, Vol. 17,
pp. 237-241.
Mental Fatigue. Am. Phys. Ed. Beview,
March and June, 1899, Vol. 4, pp.
19-29, 121-135.
The Joseph Story. N. Y. Teachers''
Magazine, April, 1899, Vol. 1, pp.
331-334.
Drawing in the Early Years. Proc. N.
E. A., 1899.
ALEXANDER G. McADIE: —
A.B., College of City of New York, 1881 ;
A.M., ibid., 1884 ; Student, Harvard Uni-
versity, 1882-85; A.M., ibid., 1885 ; Phys-
ical Laboratory, U. S. Signal Office, 1886-
87 ; Fellow in Physics, Clark Univer-
sity, 1889-90; U. S. Signal Office,
Washington, 1890-91 ; U. S. Weather Bu-
516
Titles of
reau, Washington, 1891-95; Hodgkins
Medal and Honorable Mention, Smith-
sonian Institution, 1895; Local Forecast
Official, New Orleans, 1898-09 ; Forecast
Official, San Francisco, 1899-; Honorary
Lecturer in Meteorology, University of
California; Director, California Climate
and Crop Service.
Author of : —
On the Aurora. U. S. Signal Service
Note, No. 18, pp. 21, 5 maps, 12 charts.
Protection against Lightning. Am. 3Iet.
Jour., June, 1885, Vol. 2, pp. 60-66.
Atmospheric Electricity at High Altitudes.
Proc. Am. Academy, 1885, Vol. 13, pp.
129-134.
Electrometer Work. Monthly Weather
Bevieiv, 1886-87, Vol. 14, pp. 166-167.
Observations of Atmospheric Electricity.
Am. Met. Jour., March, 1887, Vol. 3,
pp. 523-531 ; April, 1887, Vol. 3, pp.
551-561 ; May, 1887, Vol. 4, pp. 21-31.
William Ferrell. Ibid., Feb., 1888, Vol.
4, pp. 441-449.
Lightning and the Electricity of the At-
mosphere. Ibid., May, 1889, Vol. 6,
pp. 1-4.
Tornadoes. Prize Essay. Ibid., Vol. 7,
pp. 179-192.
Mean Temperatures in the United States.
Professional Paper, U. S. Signal Office,
June, 1891. Washington, 1891. 45 pp.
Franklin's Kite Experiment. Am. Met.
Jour., July, 1891, Vol. 8, pp. 97-108.
Shall We erect Lightning Rods? Ibid.,
July, 1892, Vol. 9, pp. 60-66.
Experiments in Atmospheric Electricity.
Annals of Observatory of Harvard Col-
lege, Vol. 40, Part 1, pp. 53-58.
Experiments in Atmospheric Electricity at
Blue Hill, 1892. Annals of Observa-
tory of Harvard College, Vol. 40, Part
2, pp. 120-124.
Energy of a Flash of Lightning. Proc. of
the Internal. Met. Congress, Chicago,
1893, Paper 5, Part 1, pp. 18-21.
Utilization of Cloud Observations. Ibid.,
Paper 6, Part 1, pp. 21-26.
Protection from Lightning. U. S. Weather
Bureau, Bulletin No. 15, 1894.
A Colonial Weather Service. Pop. Set.
3Io., July, 1894, Vol. 45, pp. 331-337.
The Storage Battery of the Air. Harper'' s
Magazine, July, 1894, Vol. 89, pp. 216-
219.
New Cloud Classifications. Proc. Phil.
Soc. of Washington, March 2, 1895,
Vol. 13, pp. 77-86.
The Work and Equipment of an Aero-
Physical Laboratory. Smithsonian In-
stitution, 1895. 30 pp. Smithsonian
Miscellaneous Collections, Vol. 39, No.
1077.
Fog Possibilities. Harper''s Magazine,
Jan., 1897, Vol. 94, pp. 263-266.
What is an Aurora ? Century 3Iagazine,
Oct., 1897, Vol. 54, pp. 874-878.
Franklin's Kite Experiments. Pop. Set.
Mo., Oct. 1897, Vol. 51, pp. 739-747.
Needless Alarm dui'ing Thunder-storms.
Century 3Iagazine, Aug., 1899, Vol. 58,
pp. 604-605.
FRANK H. McASSEY: —
A.B., Ripon College, Ripon, Wis., 1897;
Scholar in Psychology, Clark Univer-
sity, 1898-99.
J. F. Mcculloch : —
A. B., Adrian College, 1883 ; A.M., ibid.,
1889; Ph.B., ibid., 1884; Assistant Pro-
fessor of Mathematics, ibid., 1885-87 ; In-
structor in Mathematics, University of
Michigan, 1887-88 ; Assistant Professor
of Mathematics, Adrian College, 1888-89 ;
Fellow in Mathematics, Clark Univer-
sity, 1889-90; President, Adrian Col-
lege, 1890-93 ; Pastor of M. P. Church,
Fairmont, W. Va., 1893-94; Editor, Our
Church Becord, Greensboro, N. C, 1894-.
Author of : —
Rolle's Theorem extended. Annals of
Mathematics, Vol. 4, p. 5.
A Theorem in Factorials. Ibid., Vol. 4,
p. 161.
ARTHUR MacDONALD: —
A.B., University of Rochester, 1879 ; A.M.,
ibid., 1883; Union Theological Seminary,
1880-83 ; Graduate Student, Harvard Uni-
versity, 1883-85; Fellow, Johns Hopkins
Published Pajjers.
517
University, 1885; Universities of Berlin,
Leipzig, Paris, and Ziirich, 1885-88 ; Do-
cent in Ethics, Clark University , 1889-
91 ; Specialist in Education as related to
the Abnormal and Weakling Classes, U. S.
Bureau of Education, 1891- ; U. S. Dele-
gate, International Criminal Congress,
Brussels, 1892 ; International Psychological
Congress, London, 1893 ; International De-
mographical Congress, Budapest, 1894.
Author of: —
Ethics as Applied to Criminology. Jour,
of Mental Science, Jan., 1891, Vol. 37,
pp. 10-16, and Open Court, July, 1891.
Alcoholism. Medico-Legal Journal, June,
1891.
Criminal Aristocracy, or the Maffia. Med-
ico-Legal Journal, June, 1891, Vol. 9,
pp. 21-26.
Criminology. With an Introduction by C.
Lombroso, with Bibliography. Funk &
Wagnalls Co. , New York, 1894. 416 pp.
Abnormal Man. Being Essays on Educa-
cation and Crime and Related Subjects,
with Digests of Literature and a Bibli-
ography. U. S. Bureau of Education,
Washington, 1893. 445 pp.
Le Criminel-Type dans quelques formes
graves de la Criminality. Bibliographic
de Sexualite Pathologique. Un volume
in 8° illustr^ de Portraits. A Storck,
Lyon et G. Masson, Paris, 1895. 300 pp.
Education and Patho-Social Studies. Re-
print from Annual Eeport of U. S.
Commissioner of Education for 1893-
94, Washington, D. C, 1896. 67 pp.
^mile Zola: a Psycho-Physical Study of
Zola's Personality. Reprint from Open
Court, August, 1898. 18 pp.
Experimental Study of Children, including
Anthropometrical and Psycho-Physical
Measurements, with a Bibliography.
Reprint from Annual Eeport of U. S.
Commissioner of Education for 1897-
98, Washington, D. C, 1899, 325 pp.
Ueber Korpermessungen an Kindern.
Deuts. Zeits. f. Ausldndisches Unter-
richtsioesen, July, 1899, Vol. 4, pp.
253-266.
Abnormal Children. (In press.)
JOHN McGOWAN: —
B. A., University of Toronto, 1888 ; Fellow
in Mathematics, ibid., 1888-91; Scholar
in Mathematics, Clark University,
1891-92 ; Instructor in Mathematics,
Princeton College, 1892-93; Graduate
Student, University of Toronto, 1893-94 ;
Lecturer in Mathematics and Pliysics,
Toronto Technical School, 1894-95; B.S.,
University of Toronto (School of Practical
Science), 1895.
J. PLAYFAIR McMURRICH : —
B. A., University of Toronto, 1879 ; M.A.,
ibid., 1882 ; Assistant in Biological Lab-
oratory, ibid., 1880-81 ; Professor of Biol-
ogy, Ontario Agricultural College, 1882-84 ;
Instructor in Osteology, Johns Hopkins
University, 1884-86; Ph.D., Johns Hop-
kins University, 1885 ; Professor of Biology,
Haverford College, 1886-89; Docent in
Morphology, Clark University, 1889-
91 ; Assistant Professor, 1891-92 ;
Professor of Biology, University of Cin-
cinnati, 1892-94 ; Professor of Anatomy,
University of Michigan, 1894-.
Author of : —
On the Origin of the So-called Test-cells in
the Ascidian Ovum. Studies from
Biol. Lab. J. H. U. , 1882, Vol. 2. Ab-
stract in Biol.Centralblatt, 1882, Vol. 2;
Arch, de Zool. exp. etgen., 1882, Vol. 10.
Note on the Function of the " Test-cells "
in Ascidian Ova. Zool. Anzeiger, 1882,
Vol. 5. Abstract in. Jour. Boy. Micros.
Soc, 1882, Vol. 2,
On the Osteology and Development of
Syngnathus peckianus (Storer).
Quart. Jour. Micros. Sci., 1883, Vol.
23. Abstract in J. H. TJ. Circular,
1883, No. 27.
The Osteology and Myology of Amiurus
catus (L.) Gill. Proc. of the Canadian
Inst., Toronto, 1884, Vol, 2. Pre-
liminary Notice in Zool. Anzeiger,
1884, Vol. 7.
On the Structure and Affinities of Phytop-
tus. J. H. U. Circular, 1884, No. 35.
Abstract in Jour. Boy. Micros. Soc,
1885, Vol, 5.
518
Titles of
On the Tape-worm Epizootic among
Lambs (Taenia expansa). 9th Ann.
Bep. of the Ont. Agricultural College,
Toronto, 1884,
The Cranial Muscles of Amia calva (L.),
with a consideration of the Post-occipi-
tal and Hypoglossal Nerves in the
various Vertebrate Groups. Studies
from Biol. Lab. J. H. U., 1885, Vol. 3.
Preliminary Notice in J. H. U. Circu-
lar, 1885, No. 38.
On the Existence of a Post-oral Band of
CUia in Gasteropod Veligers. J. H. U.
Circular, 1885, No. 43. Abstract in
Jour. Boy. Micros. Soc, 1886, Vol.
6.
A Contribution to the Embryology of
the Prosobranch Gasteropods. Studies
from Biol. Lab. J. H. U., 1886, Vol. 3.
Preliminary Notice in J. H. U. Circular,
1886, No. 49. Abstract in Jour. Boy.
Micros. Soc, 1886, Vol. 6.
Notes on the Actiniae obtained at Beau-
fort, N. C. Studies from Biol. Lab.
J. H. U., 1887, Vol. 4.
On the Occurrence of an Edwardsia Stage
in the Free-swimming Embryos of a
Hexactinian. J. H. U. Circular,
1899, No. 70. Abstract in Jour. Boy.
Micros. Soc, 1889, Vol. 9.
A Contribution to the Actinology of the
Bermudas. Proc. of the Acad, of Nat.
Sciences, Philadelphia, 1889. Abstract
in t/owr. Boy. Micros. Soc, 1889, Vol.
9.
Note on the Structure and Systematic
Position of Lebrunea neglecta, Duch.
and Mich. Zool. Anzeiger, 1880, Vol.
12. Abstract in Jour. Boy. Micros.
Soc, 1889, Vol. 9.
Article " Reproduction" in Buck's Befer-
ence Handbook of the Medical Sciences,
1889, Vol. 8.
The Actiniaria of the Bahama Islands,
W. I. Jour, of Morph., 1889, Vol. 3.
Abstract in Jour. Boy. Micros. Soc,
1890, Vol. 10 ; American Naturalist,
1889 ; Preliminary Notice in J. H. U.
Circular, 1889, No. 70.
Contributions on the Morphology of the
Actinozoa. I. The Structure of Ceri-
anthus americanus. Jour, of 3forph.,
Oct., 1890, Vol. 4, pp. 131-150.
Contributions on the Morphology of the
Actinozoa. II. On the Development
of the Hexactinise. Ibid., Jan., 1891,
Vol. 4, pp. 303-330.
Contributions on the Morphology of the
Actinozoa. III. The Phylogeny of the
Actinozoa. Ibid., June, 1891, Vol. 5,
pp. 125-164.
The Gastrgea Theory and its Successors.
Biological Lectures, Marine Biological
Laboratory, Woods Holl. Ginn &. Co.,
Boston, 1891, pp. 79-106.
The Formation of the Germ-layers in the
Isopod Crustacea. Zool. Anzeiger,
Jahrg. 15, 1892.
Eeport on the Actiniae collected by the U.
S. Fish Commission steamer Albatross
during the winter of 1887-88. Proc
U. S. National Museum, 1893, Vol. 16,
p. 119.
A Text-book of Invertebrate Morphology.
New York, 1894.
Embryology of the Isopod Crustacea.
Jour, of Morph., May, 1895, Vol. 11,
pp. 63-154.
Cell Division and Development. Biologi-
cal Lectures, Marine Biological Labora-
tory, "Woods Holl. Ginn & Co. , Boston,
1895, pp. 125-147.
Notes on Some Actinians from the Ba-
hama Islands, collected by the late Dr.
J. I. Northrop. Annals N. Y. Acad,
of Science, 1896, Vol. 9, p. 181.
The Yolk-lobe and Centrosome of Fulgur
carica. Anat. Anzeiger, 1896, Bd. 12,
p. 534.
Contributions on the Morphology of the
Actinozoa. IV. On Some Irregulari-
ties in the Number of the Directive
Mesenteries in the Hexactinife. Zool.
Bulletin, 1897, Vol. 1.
The Epithelium of the So-called Midgut
of the Terrestrial Isopods. Jour, of
Morph., 1897, Vol. 14, p. 83.
A Case of Crossed Dystopia of the Kid-
ney with Fusion. Jour, of Anat. and
Phys., 1898, Vol. 32, p. 652.
Report on the Actiniaria collected by the
Bahama Expedition of the State Uni-
Published Papers.
519
versity of Iowa, 1893, Bull. Lab. of
Nat. Hist. State Univ. of Iowa, 1898,
Vol. 4, p. 225.
The Present Status of Anatomy. Amer-
ican Naturalist, 1899, Vol. 33, p. 185.
FRANKLIN P. MALL: —
M.D., University of Michigan, 1883;
University of Heidelberg, 1883-84;
University of Leipzig, 1884-86 ; Fellow,
Instructor, and Associate in Pathology,
Johns Hopkins University, 1886-89 ; Ad-
junct Professor of Vertebrate Anat-
omy, Clark University, 1889-92 ; Pro-
fessor of Anatomy, University of Chicago,
1892-93 ; Professor of Anatomy, Johns
Hopkins University, 1893-.
Author of : —
Entwickelung der Branchialbogen und
-Spalten des Hiihnchens. Arch. f.
Anatomie (His u. Braune), 1887,
pp. 1-34, 3 pis.
Die Blut- und Lymphwege im Diinndarm
des Hundes. Abhandl. d. K. S. Ge-
sellsch. der Wissenschaften, 1887, Vol.
24, pp. 153-189, 6 pis.
The First Branchial Arch of the Chick,
J. H. U. Circular, Feb., 1888, Vol.
7, p. 38.
The Branchial Region of the Dog, Ibid.,
Feb., 1888, Vol. 7, p. 39.
Development of the Eustachian Tube,
Middle Ear, Tympanic Membrane, and
Meatus of the Chick. Studies from
Biol. Lab. J. H. U., June, 1888, Vol.
4, pp. 185-192, 1 pi.
The Development of the Branchial Clefts
of the Dog with Special Reference to
the Origin of the Thymus Gland.
Ibid., pp. 193-216, 3 pis.
Reticulated and Yellow Elastic Tissues.
Anat. Anzeiger, June 1, 1888, Vol. 3,
pp. 397-401.
Die motorischen Nerven der Portalvene,
Du Bois-Reymond's Arch.f. Physiolo-
gie, 1890, Supp. Band, pp. 57-58.
Development of the Lesser Peritoneal
Cavity in Birds and Mammals. Jour.
of Morph., June, 1881, Vol. 5, pp.
165-179.
Das Reticulirte Gewebe. Abhandl. d. K.
S. Gesellsch. der Wissenschaften, 1891,
Vol. 17, pp. 293-338, 11 pis.
A Human Embryo Twenty-six Days Old,
Jour, of 3Iorph., Dec, 1891, Vol. 5,
459-480, 2 pis.
Methods of preserving Human Embryos.
American Naturalist, Dec, 1891, Vol.
25, pp. 1144-1146.
Der Einfluss des Systems der Vena portae
auf die Vertheilung des Blutes. Du
Bois-Beymond^s Arch. f. Physiologie,
1892, pp, 409-453.
The Vessels and Walls of the Dog's Stom-
ach. J. H. Hospital Reports, 1896,
Vol. 1, pp. 1-36, 5 pis.
A Study of the Intestinal Contraction,
Ibid., pp. 37-75, 3 pis.
Healing of Intestinal Sutures. Ibid.,
pp. 76-92.
Reversal of the Intestine. Ibid., pp. 93-
110.
A Human Embryo of the Second Week.
Anat. Anzeiger, Aug. 5, 1893, Vol. 8,
pp. 630-633.
Histogenesis of the Retina in Amblystoma
and Necturus. Jour, of Morph., May,
1893, Vol. 8, pp, 415-432.
Ccelom, pp. 184-189 ; Human Embryos,
pp. 268-269 ; The Heart, pp. 391-395 ;
Development of the Thymus Gland,
pp. 875-877 ; Development of the
Thyroid Gland, pp. 879-882. Ref.
Handbook of Med. Sciences (Supp.
Vol.).
What is Biology ? Chaiitauquan, Jan.,
1894, Vol. 18, pp. 411-414.
Early Human Embryos and the Mode of
their Preservation. Bull, of J. H.
Hospital, Dec, 1893, Vol, 4, pp. 115-
121.
The Preservation of Anatomical Material
for Dissection. Anat. Anzeiger, April
9, 1896, Vol. 11, pp. 769-775.
The Contraction of the Vena Portse and
its Influence upon the Circulation. J.
H. Hospital Reports, 1896, Vol. 1, pp.
111-156.
Reticulated Tissue and its Relation to the
Connective Tissue Fibrils. Ibid. , 1896,
Vol, 1, pp. 171-208, 9 pis.
520
Titles of
The Anatomical Course and Laboratory
of the Johns Hopkins University.
Bull, of J. H. Hospital, May-June,
1896, Vol. 7, pp. 85-100, 5 pis.
Development of the Human Coslom.
Jour, of Morph., Feb., 1897, Vol. 12,
pp. 395^53.
Ueber die Entwickelung des menschlichen
Darmes und seiner Lage beim Erwach-
senen. His.'' s Arch. f. Anatomie, 1897,
Supp. Band, pp. 403-434, 10 pis.
Development of the Ventral Abdominal
Walls in Man. Jour, of Morph. , June,
1898, Vol. 14, pp. 347-366, 6 pis.
Development of the Human Intestine and
its Position in the Adult. Bull, of
J. H Hospital, Sept.-Oct., 1898, Vol.
9, pp. 197-208, 5 pis.
The Lobule of the Spleen. Ibid., pp.
218-219.
Development of the Internal Mammary
and Deep Epigastric Arteries in Man.
lUd., pp. 232-235.
The Value of Embryological Specimens.
Md. Med. Jour., Oct. 29, 1898, Vol.
40, p. 29.
Liberty in Medical Education. Phila.
Med. Jour., April 1, 1899, Vol. 3, p.
720.
CHARLES W. MARSH: —
Ph.B., Columbia College, School of
Mines, 1879; Ph.D., Columbia College,
1882 ; Assistant in Chemistry, Green
School of Science, Princeton, N. J., 1882-
85 ; University of Berlin, 1885-87; Assist-
ant in Chemistry, Lehigh University,
1887-89 ; Honorary Fellow in Chemis-
try, Clark University, 1889-90 ; Elec-
trical Engineer, New York City, 1893-.
Author of : —
Note on the Ammonia-Process for "Water
Analysis. Am. Chem. Jour., July,
1882, Vol. 4, pp. 188-192.
A Method for the Detection of Chlorine,
Bromine, Iodine, and Sulphur in Or-
ganic Compounds. Ibid., April, 1889,
Vol. 11, pp. 240-244.
A New Form of Adapter. Am. Jour, of
Anal. Chem., Jan., 1889.
The Reduction of Barium Sulphate to
Barium Sulphide on Ignition with
Filter Paper. Ibid., April, 1889.
ALFRED G. MAYER: —
M.E., Stevens Institute, Hoboken, N. J.,
188!) ; Assistant in Physics, Clark Uni-
versity, 1889-90 ; Assistant in Physics,
University of Kansas, 1890-92 ; Graduate
Student in Zoology, Harvard University,
1892-95 ; Museum Assistant in Charge of
Radiates, Echinoderms, and Polype, and
Assistant to Dr. Alexander Agassiz,
1895- ; Sc.D., Harvard University, 1896;
Member of : American Society of Natu-
ralists, American Morphological Society,
Boston Society of Natural History, Ameri-
can Association for Advancement of Sci-
ence ; President of the Cambridge Ento-
mological Society.
Author of : —
Radiation and Absorption of Heat by
Leaves. Am. Jour, of Sci., April,
1893, Vol. 45, pp. 340-346.
Some New Medusfe from the Bahamas.
Bull. Mus. Comp. Zool, 1894, Vol. 25,
pp. 23.5-242, 3 pis.
Color and Color-Patterns of Moths and
Butterflies. Ibid., 1897, Vol. 30, pp.
169-256, 10 pis.
The Development of Wing Scales and their
Pigment in Butterflies and Moths.
Ibid., 1896, Vol. 29, pp. 209-236, 7 pis.
A New Hypothesis of Seasonal Dimor-
phism in Lepidoptera. Psyche, April-
May, 1897, Vol. 8, pp. 47-50, 59-62.
On Dactylometra. (With A. Agassiz.)
Bull. Mus. Comp. Zool., 1898, Vol. 32,
pp. 1-11, 13 pis.
On Some Medusse from Australia. (With
A. Agassiz.) Ibid., 1898, Vol. 32, pp.
12-19, 3 pis.
Acalephs from the Fiji Islands. (With
A. Agassiz.) Ibid., 1899, Vol. 32, pp.
151-189, 17 pis.
On an Atlantic "Palolo" Worm. Ibid.
(In press.)
Medusse of the Atlantic Coast of North
America. (With A. Agassiz.) Mem.
Mus. Comp. Zool.
Published Papers.
521
A. D. MEAD: —
A.B., Middlebury College, 1890; A. M.,
Brown University, 1891 ; Fellow in Mor-
phology, Clark University, 1891-92 ;
Fellow in Biology, University of Chicago,
1892-95; Pli.D., University of Chicago,
1895 ; Instructor in Comparative Anatomy,
Brown University, 1895-96 ; Associate
Professor of Embryology and Neurology,
ibid., 1897-.
Author of : —
Preliminary Account of the Cell-Lineage
of Amphitrite and other Annelids.
Jour, of 3Iorph., Sept., 1894, Vol. 9,
pp. 465-473.
Some Observations on Maturation and
Fecundation of Chsetopterus perga-
mentaceus Cuvier. Ibid., Jan., 1895,
Vol. 10, pp. 313-317.
The Origin of the Egg Centrosomes.
Ibid., Feb., 1897, Vol. 12, pp. 391-394.
The Early Development of Marine Anne-
lids. (Thesis.) /6id., May, 1897, Vol.
13, pp. 227-326.
The Origin and Behavior of the Centro-
somes in the Annelid Egg. Ibid.,
June, 1898, Vol. 14, pp. 181-218, 4 pis.
The Rate of Cell Division and the Function
of the Centrosome. Woods Hall Biol.
Lectures, 1896-97. Ginn & Co., Bos-
ton, 1898, pp. 20.3-218.
The Breeding of Animals at "Woods Holl
during the Month of April, 1898.
Science, May 20, 1898, N, S., Vol. 7,
pp. 702-704.
Habits and Life History of the Starfish. I.
SSth Rep. of the Com. of Inland Fish-
eries of B. I., 1898.
Habits and Life History of the Starfish.
IL S9thBep., ibid., 1899.
Peridinium and the "Red Water" in
Narragansett Bay. Science, Nov 18,
1898, N. S., Vol. 8, pp. 707-709.
The Cell Origin of the Prototroch. Woods
Holl Biol. Lectures, 1898.
GEORGE P. METZLER: —
A.B., Albert College, Ontario, Can.,
1880; Head Master, Port Dover High
School, 1880-81; Professor of Mathe-
matics, Albert College, 1881-84; A.M.,
Victoria College, 1883 ; Professor of
Mathematics, Marietta College, 1889-90 ;
Ph.D., Johns Hopkins University, 1891 ;
Honorary Fellow in Psychology,
Clark University, 1891-92 ; Docent in
University of Chicago and Instructor in
Mathematics, University of Michigan,
1892-93 ; University of Gottingen, 1893-
94 ; University of Berlin, 1894-95 ; Asso-
ciate in Mathematics, Queens College,
1896-97 ; Assistant Pastor Methodist
Church, Newburgh, Can., 1897-98 ; Pas-
tor of Methodist Church, Wilberforce,
Canada, 1898-.
Author of: —
Equations and Variables Associated with
the Linear Differential Equation. An-
nals of Math., Vol. 9, pp. 171-178 ;
Vol. 11, pp. 1-9.
Surfaces of Rotation with Constant Meas-
ure of Curvature and their Represen-
tation on the Hyperbolic (Cayley's)
Plane. Am. Jour, of Math., Jan. , :
Vol. 20, pp. 76-86.
WILLIAM H. METZLER: —
A.B., University of Toronto,
Science Master, Collegiate Institute, Inger-
soll, Ont., 1888-89 ; Fellow in Mathe-
matics, Clark University, 1889-92;
Ph.D., Clark University, 1893; In-
structor in Mathematics, Massachusetts
Institute of Technology, 1892-94 ; Pro-
fessor of Mathematics, Genesee Wesleyan
Academy, 1894-95 ; Associate Professor
of Mathematics, Syracuse University,
1895-96 ; Professor of Mathematics, ibid.,
1896- ; Member of : American Association
for the Advancement of Science ; Ameri-
can Mathematical Society ; Deutsche
Mathematilier-Vereinigung ; Mathemat-
ical Association (England) ; British As-
sociation for the Advancement of Science ;
London Mathematical Society.
Author of : —
On the Roots of Matrices. Am. Jour, of
3Iath., Oct., 1892, Vol. 14, pp. 326-
377.
522
Titles of
On Certain Properties of Symmetric, Skew
Symmetric, and Orthogonal Matrices.
Ihid., July, 1893, Vol. 15, pp. 274-282.
Homogeneous Strains. Annals of Math.,
Vol. 8, No. 5.
On Compound Determinants. Am. Jour,
of Math., April, 1894, Vol. 16, pp.
131-150.
Matrices which Represent Vectors. Tech-
nology Quarterly, Vol. 6. No. 4.
Some Notes on Symmetric Functions.
Proc. London Math. Soc, March 11,
1897, Vol. 28, pp. 390-393.
Compound Determinants. Am. Jour, of
Math., July, 1898, Vol. 20, pp. 253-
272.
A Theorem in Determinants. Ibid. , July,
1898, Vol. 20, pp. 273-276.
On the Excess of the Number of Combina-
tions in a set which have an even
number of inversions over those which
have an odd number. (In press.)
On the Roots of a Determinantal Equa-
tion. Am. Jour, of Math., Oct., 1899,
Vol. 21, pp. 367-368.
On a Determinant each of whose Elements
is the Product of K Factors. (In
press.)
On a Theorem in Determinants related to
Laplace's. (In press.)
ADOLF MEYER : — '
Maturitatsexamen, Gymnasium, Ziirich,
1885 ; Medical Staatsexamen, Zurich,
1890; Graduate Student in Medicine,
Paris, Edinburgh, and London, 1890-91 ;
Neurological Work in the Laboratory of
the Clinic of Psychiatry of Professor A.
Forel, Zurich, 1891 ; Neurological Student,
Vienna, 1892 ; M.D., University of Zurich,
1892 ; Decent in Neurology, University of
Chicago, and Pathologist, Illinois Hospital
for the Insane, 1893-95 ; Director of the
clinical and laboratory work, Worcester
Insane Hospital, 1895- ; Docent in Psy-
chiatry, Clark University, 1895-.
Author of : —
Medicinische Studien in Paris, Edinburgh,
und London. Correspondenz-Blatt
fur Schweizer Aerzte, June 1, 1891,
Vol. 21, pp. 350-357 ; June 15, pp.
381-386 ; July 1, pp. 417-420.
Ueber das Vorderhirn eiuiger Reptilien.
Zeitschrift fur wissenschaftliche Zo-
ologie, 1892, Vol. 55, pp. 63-133, 2
pis.
Zur Homologie der Fornixcommissur und
des Septum lucidum bei den Reptilien
und Saugern. Anatomischer Anzeiger,
March 15, 1895, Vol. 10, pp. 474-482.
Neurological Work at Zurich. Journal of
Comparative Neurology, 1893, Vol. 3,
pp. 1-6, 41-44, 114-118.
How Can We Prepare Neurological Ma-
terial to the Best Advantage ? Jour-
nal of Nervous and Mental Diseases,
May, 1894, Vol. 19, pp. 277-291.
Considerations on the Findings in the
Spinal Cord of Three General Para-
lytics. Am. Jour, of Insanity, Jan.,
1895, Vol. 51, pp. 374-379.
Mental Abnormalities in Children during
Primary Education. Tran. III. Soc.
for Child Study, Dec, 1894, Vol. 1,
No. 1, pp. 48-58.
Schedule for the Study of Mental Abnor-
malities in Children. Ibid., May,
1895, Vol. 1, No. 2, pp. 53-57.
On the Observation of Abnormalities of
Children. Child Study Monthly, May,
1895, Vol. 1, pp. 1-12.
Report to the Governor of Illinois on the
Treatment of the Insane. Compila-
tion of Special Beports, etc., Spring-
field, 111., 1894, pp. 18-29.
A Few Demonstrations of Pathology of
the Brain and Remarks on the Prob-
lems connected with Them. Am.
Jour, of Insanity, Oct., 1895, Vol. 52,
pp. 243-249, 3 pis.
On the Diseases of Women as a Cause of
Insanity in the Light of Observations
in Sixty-nine Autopsies. Tran. of the
III. State Med. Soc, 1895.
A Review of the Signs of Degeneration
and of Methods of Registration. Ain.
Jour, of Insanity, Jan., 1896, Vol. 52,
pp. 344-363.
Pathological Report of the Illinois Eastern
Hospital for the Insane at Kankakee,
111. Chicago, 1896, pp. 1-236, 16 pis.
Published Paj)ers.
523
A Case of Landry's Paralysis, with Au-
topsy. (With Dr. Th. Diller.) Am.
Jour, of the Medical Sciences, April,
1896, Vol. 115, pp. 404^13.
Etiological, Clinical, and Pathological
Factors in Diagnosis and Rational
Classification of Infectious, Toxic, and
Asthenic Diseases of the Peripheral
Nerves, Spinal Cord, and Brain. 3Iecli-
cine, Detroit, Mich., Aug. 1896, Vol. 2,
pp. 6.39-652.
A Short Sketch of the Problems of Psy-
chiatry. A7n. Jour, of Insanity, April,
1897, Vol. 53, pp. 538-549.
General Paralysis and Other Nervous and
Mental Affections Following Syphilitic
Infection. Yale Medical Journal,
May, 1897, Vol. 3, pp. 311-317.
Demonstration of Various Tjrpes of
Changes in the Giant Cells of the
Paracentral Lobule. Am. Jour, of
Insanity, Oct. 1897, Vol. 64, pp. 221-
226, 3 pis.
Anatomical Findings in a Case of Facial
Paralysis of Ten Days' Duration in a
General Paralytic, with Remarks on
the Termination of the "Auditory"
Nerves. Jour, of Experimental Medi-
cine, Nov. 1897, Vol. 2, pp. 607-610,
2 pis.
Special Report of the Medical Depart-
ment of the Worcester Lunatic Hos-
pital. Annual Report, Oct. 1898, pp.
20-27.
Critical Review of the Data and General
Methods and Deductions of Modern
Neurology. Jour, of Comp. Neurol-
ogy, Nov.-Dec, 1898, Vol. 8, pp. 11.3-
148 ; 249-313, 7 pis.
Critical Review of Recent Publications of
Bethe and Nissl. Ihid., March, 1899,
Vol. 9, pp. 38-45.
Reviews in the Neurologisches Central-
blatt, Psychological Bevieio, Am, Jour.
of Insanity, Jour, of Nervous andMen-
tal Disease.
ARTHUR MICHAEL: —
University of Heidelberg, 1873-75 ; Uni-
versity of Berlin, 1875-78 ; :fecole de M^de-
cine, 1879-80 ; Professor of Chemistry,
Tufts College, 1881-89 ; Ph.D. (Honor-
ary), Tufts College, 1889; Professor of
Chemistry, Clark University, Sept.-
Dec. , 1889 ; Research Work in England,
1890-94 ; Professor of Chemistry, Tufts
College, 1894-.
Author of: —
Ueber die Einwirkung von Kaliumsulfhy-
drat auf Chloralhydrat. Ber. d. deuts.
chem. Gesellschaft, 1876, Vol. 9, pp.
1267-1268.
Ueber die Darstellung und Eigenschaften
des Trijodresorcins. (With T. H.
Norton.) Ibid., Vol. 9, pp. 1752-1753.
Ueber die Einwirkung von wasserentzie-
henden Mitteln auf Saureanhydride.
(With S. Gabriel.) Ibid., 1877, Vol.
10, pp. 391-393; 1551-1562, 2199-
2210; 1878, Vol. 11, pp. 1007-1021,
1679-1683.
Zur Darstellung der Paramidobenzoesaure.
Ibid., 1877, Vol. 10, pp. 576-580.
Ueber die Diamidosulfobenzid-Dicarbon-
saure. (With T. H. Norton.) Ibid.,
Vol. 10, pp. 580-583.
Zur Kenntniss der aromatischen Sulfone.
(With A. Adair.) Ibid., Vol. 10, pp.
583-587.
Ueber die Einwirkung des Broms auf
Aethylphtalimid. Ibid. Vol. 10, pp.
1644-1645.
Ueber die Einwirkung des Chlorjods auf
aromatische Amine. (With L. M.
Norton.) Ibid., 1878, Vol. 11, pp.
107-116.
Zm- Kenntniss der aromatischen Sulfone.
(With A. Adair.) Ibid., Vol. 11, pp.
116-121.
Ueber Benzylmethylglycolsaure. (With
S. Gabriel.) Ibid., 1879, Vol. 12, pp.
814-816.
On the Action of Iodine Monochloride
iipon Aromatic Acids. (With L. M.
Norton.) Ain. Chem. Jour., 1879,
Vol. 1, pp. 255-267.
On the Synthesis of Helicin and Phenol-
glucoside. Ibid., Vol. 1, pp. 305-312.
On a New Formation of Stilbene and some
of its Derivatives. Ibid., Vol. 1, pp.
312-316.
524
Titles of
On Mono-Ethylphthalate. Ibid., 1880,
Vol. 1, pp. 413-416.
On a New Formation of Ethyl-Mustard
Oil. Ibid., Vol. 1, pp. 41G-418.
On the Preparation of Methyl Aldehyde.
Ibid., Vol. 1, pp. 418-420.
On the ' ' Migration of Atoms in the Mole-
cule" and Reimer's Chloroform Alde-
hyde Reaction. Ibid., Vol. 1, pp.
420-426.
On a- and fc-Monobromcrotonic Acids.
(WithL. M. Norton.) Ibid., Vol. 2,
pp. 11-19.
Preliminary Note on the Synthesis of
Methylconine and Constitution of Co-
nine. (With Charles Gundelach.)
Ibid., Vol. 2, pp. 171-172.
Ueber die Einwirkung von aromatischen
Oxysjiuren auf Phenole. Ber. d.
deuts. chem. Gesellschaft, 1881, Vol.
14, pp. 656-658.
Ueber die Synthese des Methylarbutins.
Ibid. Vol. 14, pp. 2097-2102.
Zur Kenntniss des Paraconiins. Ibid.,
Vol. 14, pp. 2105-2110.
Ueber die Synthese des Salcins und des
Anhydrosalicylglucosids. Ibid., 1882,
Vol. 15, pp. 1922-1925.
On the Action of Aromatic Oxy-acids on
Phenols. Am. Chem. Jour., 1883,
Vol. 5, pp. 81-97.
On Some Properties of Phenylsulphona-
cetic Ethers. (With A. M. Comey.)
Ibid., Vol. 5, pp. 116-119.
Synthetical Researches in the Glucoside
Group. Ibid., Vol. 5, pp. 171-182.
On the Formation of Crotonic and 6-Oxy-
butric Aldehydes from Ethyl Alde-
hyde. (With Adolph Kopp.) Ibid.,
Vol. 5, pp. 182-191.
On the Action of Sodium Ethyl Oxide on
Bromethylidenebromide. Ibid., Vol.
5, pp. 192-197.
A New Synthesis of Allantoin and Some
Suggestions on the Constitution of
Uric Acid. Ibid., Vol. 5, pp. 198-
202.
On a Convenient Method for Preparing
Bromacetic Acid. Ibid., Vol. 5, pp.
202-203.
On Several Cases of Intermolecular Re-
arrangement. Ibid. , Vol. 5, pp. 203-
205.
On a New Synthesis of Cinnamic Acid.
Ibid., Vol. 5, pp. 205-206.
On the Action of Aldehydes on Phenols.
Ibid., Vol. 5, pp. 339-349.
Action of Ethylaldehyde on Orcin and
Resorcin. (With A. M. Comey.)
Ibid., Vol. 5, pp. 349-353.
Some Convenient Quantitative Lecture
Apparatus. Ibid., Vol. 5, pp. 353-
359.
Observations on the Action of Acetyl-
chloride and Acetic Anhydride on
Corn and Wheat Starch. Ibid., Vol.
5, pp. 359-360.
On the Constitution of Resocyanin. Ibid.,
Vol. 5, pp. 434-440.
Ueber die optisch-inactive Asparaginsaure.
(With J. F. Wing.) Ber. d. deuts.
chem. Gesellschaft, 1884, Vol. 17, p.
2984.
On the Action of Sodium Phenylsulphin-
ate on Methylene Iodide. (With G.
M. Palmer.) Am. Chem. Jour., 1884,
Vol. 6, pp. 253-257.
On the Conversion of Organic Isocyanates
into Mustard Oils. (With G. M.
Palmer.) Ibid., Vol. 6, pp. 257-260.
Synthetical Researches in the Glucoside
Group. Ibid., Vol. 6, pp. 336-340.
On the Action of Methyl Iodide on As-
paragine. (With J. F. Wing.) Ibid.,
1885, Vol. 6, pp. 419-422.
On Some Properties of Phenylsulphona-
cetic Ethers. (With G. M. Palmer.)
Ibid., Vol. 7, pp. 65-71.
Note on the Constitution of the Addition-
Product of Chlorhydric Acid to Ethyl-
cyanide. (With J. F. Wing.) Ibid.,
Vol. 7, pp. 71-74.
On the Decomposition of Cinchonine by
Sodium Ethylate. Ibid., Vol. 7, pp.
182-189.
On Simultaneous Oxidation and Reduc-
tion by Means of Hydrocyanic Acid.
(With G. M. Palmer.) Ibid., Vol. 7,
pp. 189-194.
On the Action of Alkyl Iodides on Amido
Acids. (With J. F. Wing.) Ibid.,
Vol. 7, pp. 195-199.
Published Paj^ers.
525
On Eesacetophenone. (With G. M.
Palmer.) Ihid., Vol. 7, pp. 275-277.
On Inactive Aspartic Acid. (With J. F.
Wing.) Ibid., Vol. 7. pp. 278-281.
Ueber die Einwirkung von FUnffach-
Chlorphosphor auf die Aether organ-
ischer Sauren. Ber. d. deuts. chem.
Gesellschaft, 1886, Vol. 19, pp. 84.5-
847.
Ueber einen Zusammenhang zwischen
Anilidbildung und der Constitution
ungesattigter, mehrbasischer, organ-
ischer Sauren. Ibid., Vol. 19, pp.
1372-1375.
Ueber einen Zusammenhang zwischen
Anilidbildung und der Constitution
ungesattigter, mehrbasischer, organ-
ischer Sauren. (With G. M. Palmer.)
Ibid., Vol. 19, pp. 1375-1376.
Ueber die Einwirkung des Anilins auf die
Brommalein und Chlorfumarsaure.
Ibid., Vol. 19, pp. 1377-1378.
Zur Isomeric in der Zimmtsaurereihe.
(With G. M. Browne.) Ibid., Vol.
19, pp. 1378-1381.
Zur Isomeric in der Fettreihe. Ibid.,
Vol. 19, pp. 1381-1386.
Ueber die Nitrirung des Phenylhydrazins.
Ibid., Vol. 19, pp. 1368-1388.
Zur Kenntniss der Einwirkung von Alde-
hyden auf Phenole. (With J. P. Ry-
der.) Ibid., Vol. 19, pp. 1388-1390.
Die Citraconsaure als Reagenz zur Erken-
nung und Scheidung der aromatischen
Amine. Ibid., Vol. 19, pp. 1390-1392.
Ueberfiihrung der a-Bromzimmtather in
Benzoylessigather. (With G. M.
Browne.) Ibid., Vol. 19, pp. 1392-
1393.
Zur Isomeric in der Zimmtsaurereihe.
(With G. M. Browne.) Ibid., 1887,
Vol. 20, pp. 550-556.
Bemerkungen zu einer Abhandlung des
Hrn. L. Claisen. Ibid., Vol. 20, pp.
1572-1573.
On the Addition of Sodium Acetacetic
Ether and Analogous Sodium Com-
pounds to Unsaturated Organic Ethers.
Am. Chem. Jour., 1887, Vol. 9, pp.
112-124.
On Some New Reactions with Sodium
Acetacetic and Sodium Malonic Ethers.
Ibid., Vol. 9, pp. 124-129.
On the Action of Aldehydes on Phenols.
(With J. P. Ryder.) Ibid., Vol. 9,
pp. 130-137.
Researches on Alloisomerism. Ibid., Vol.
9, pp. 180-183.
A Relation between the Constitution of
Polybasic Unsaturated Organic Acids
and the Formation of their Anilides.
Ibid., Vol. 9, pp. 183-197.
A Relation between the Constitution of
Polybasic Unsaturated Organic Acids
and the Formation of their Anilides.
(With G. M. Palmer.) Ibid., Vol. 9,
pp. 197-204.
On the Action of Phosphorus Pentachlo-
ride on the Ethers of Organic Acids,
and on some Derivatives of Acetic
Acid. Ibid., Vol. 9, pp. 205-217.
On the Action of Phosphorus Pentachlo-
ride on Acetanilide. Ibid., Vol. 9, pp.
217-219.
Preliminary Notes. Ibid., Vol. 9, pp.
219-222.
Researches on Alloisomerism. (With G.
M. Browne.) Ibid., Vol. 9, pp. 274-
289.
Remarks on the Constitution of Levulinic
and Maleic Acids. Ibid., Vol. 9, pp.
364-372.
Ueber eine bequeme Darstellungsweise von
bromirten Fettsauren. Jou7: f. prak-
tische Chemie, 1887, Vol. 35, pp. 92-95.
Das Verhalten von Essigsaure und einigen
Derivaten derselben gegen Fiinffach-
Chlorphosphor. Ibid., Vol. 35, pp.
95-96.
Ueber die Constitution der Trimethylen-
tricarbonsaure. Ibid., Vol. 35, pp.
132-136.
Zur Kenntniss der Einwirkung des Fiinf-
fach-Chlorphosphors auf Acetanilid.
Ibid., Vol. 35, pp. 207-208.
Ueber die Bildung des Indigblau aus
Orthonitrophenylpropiolsaure mittelst
Cyankalium. Ibid., Vol. 35, pp. 254-
256.
Ueber Alloisomerie in der Crotonsaure-
reihe. (With G. M. Browne.) Ibid.,
Vol. 35, pp. 257-259.
526
Titles of
Ueber die Addition von Natriumacetessig-
und Natriummalonsaureatliern zu den
Aethern ungesattigter Sauren. Ibid.,
Vol. 35, pp. 349-356.
Die Reduction von Alpha- und AUoalpha-
bromzimmtsauren zn Ziinmtsaure.
Ihid., Vol. 35, pp. 357-358.
Ueber aromatische Hydroxylamine. ("With
G. M. Browne.) Ibid., Vol. 35, pp.
358-359.
Ueber neue Reactionen mit Natriumacet-
essig- und Natriummalonsaureather.
Ibid., Vol. 35, pp. 449-459.
Ueber das Verhalten von Oxalsaureather
zu Resorcin. Ibid., Vol. 35, pp. 510-
512.
Antwort auf eine Bemerkung von L.
Claisen. Ibid., Vol. 36, pp. 113-114.
Zur Isomerie in der Crotonsaurereihe.
(With G. M. Browne. ) Ibid. , Vol. 36,
pp. 174-176.
Zur Constitution des Natriumacetessig-
athers. Ibid., 1888, Vol. 37, pp. 473-
530.
Ueber das Verhalten von Natriummalon-
ather gegen Resorcinol. Ibid., Vol. 37,
pp. 469-471.
Zur Alloisomerie in der Crotonsaurereihe.
(With H. Pendleton.) Ibid., Vol. 38,
pp. 1-5.
Zur Kritik der Abhandlung von J,
Wislicenus : ' ' Ueber die raumliche
Anordnung der Atome in organischen
Molekulen." Ibid., Vol. 38, pp. 6-39.
Preliminary Note on the Constitution of
Sodium Acetacetic and Malonic Ethers.
Am. Chem. Jour., 1888, Vol. 10, pp.
158-160.
Bemerkung zu der Abhandlung von Otto
und Rossing liber die Ersetzbarkeit des
Natriums im Natriumphenylsulfones-
sigather durch Alkyle. Ber. d. deuts.
chem. Gesellschaft, 1890, Vol. 23, pp.
669-671.
On the Constitution of Sodium Acetacetic
Ether. Am. Chem. Jour., 1892, Vol.
14, pp. 481-544.
On the Action of Acetic Anhydride on
Phenylpropiolic Acid. (With J. E.
Bucher.) Ibid., 1898, Vol 20, pp. 89-
120.
On the Formation of Imido-1, 2-Diazo.
Derivatives from Aromatic Azimides
and Esters of Acetylenecarboxylic
Acids. (With F. Luehn and H. H,
Higbee.) Ibid., Vol. 20, pp. 377-
395.
Zur Schmelzpunktsbestimmung von hoch-
schmelzenden und sogen. unschmelz-
baren organischen Verbinduugen. Ber.
d. deuts. chem. Gesellschaft, 1895,
Vol. 28, pp. 1629-1633.
Ueber die Addition von Schwefel zu un-
gesattigten organischen Verbindungen.
Ibid., Vol. 28, pp. 1633-1637.
Ueber die Einwirkung von Essigsaurean-
hydrid auf Sauren der Acetylenreihel.
(With J. E. Bucher.) Ibid., Vol. 28,
pp. 2511-2512.
Einwirkung v. Aethyljodid u. Zink auf
A a |3-Fettester. Ibid., Vol. 29, p. 1791.
Zur Kenntniss der Additionsvorgange bei
den Natriumderivaten von Formyl- uud
Acetessigestern, imd Nitroathanen.
Ibid., Vol. 29, pp. 1794-1799.
Zur Constitution der Oxalessigsaure.
(With J. E. Bucher.) Ibid., Vol. 29,
pp. 1792-1793.
Ueber die Regelmassigkeiten bei der Anla-
gerung von Halogenverbindungen auf
ungesattigten Sauren. Jour. f. prakt.
Chemie, 1889, Vol. 40, pp. 171-179.
Ueber die Einwirkung von Jodwasserstoff
auf die Krotonsauren. Ibid., Vol, 40,
pp. 95-96.
Zur Kenntniss der Lavulinsaure und des
Acetondiessigsauredilaktons. Ibid.,
Vol. 43, pp. 113-1.30.
Ueber die Addition von Natriumacetessig-
und Natriummalonsjiureathern zu den
Aethern ungesattigter Sauren. (With
P. C. Freer.) Ibid., Vol. 39, pp. 390-
395.
Zur Kenntniss der Halogenentziehung bei
organischen a j8-Halogensaureathern.
(With O. Schulthess.) Ibid., Vol, 39,
pp. 587-596.
Ueber die Addition von Brom zu Acetylen-
dicarbonsaure und deren Althyliither.
Ibid., Vol. 46, pp. 210-233.
Ueber die Einwirkung von Natrium-
athylat auf Dibrombernsteinsaure-
Published Papers.
527
ather, (With C. C. Maisch.) Ibid.,
Vol. 46, pp. 233-236.
[Jeber die Crotonsaure vuid Derivate der-
selben. (With O. Scliulthess.) Ibid.,
Vol. 46, pp. 236-266.
Ueber die Bildung von fester Crotonsaure
bei der Reduction von allo-cc-Brom-
und-chlorcrotonsaure. Ibid., Vol. 46,
pp. 266-272.
Beitrage zur Kenntniss einiger Homologen
der Aepfelsaure. (With G. Tissot.)
Ibid., Vol. 46, pp. 285-304.
Ueber die Addition von Chlor zu mehr-
basischen, ungesattigten Fettsauren.
(With G. Tissot.) Ibid., Vol. 46, pp.
381-427.
Ueber die Addition von Natriumacetessig-
und Natriumacetmalonather zu den
Aethern ungesattigter Sauren. Ibid.,
Vol. 49, pp. 20-25.
Beitrage zur Kenntniss der Ringbildung
bei organischen, stickstoffhaltigen Ver-
bindungen. Ibid., Vol. 49, pp. 26-43.
Untersuchungen iiber Alloisomerie.
Ibid., Vol. 49, pp. 289-372.
Ueber das Verhalten von Benzaldehyd
gegen Phenol. Ibid., Vol. 57, 334-
336.
Ueber einige Gesetze und deren Anwen-
dung in der organischen Chemie.
Ibid., Vol. 60, pp. 286-470.
ALBERT A. MICHELSON : —
Midshipman, U. S. Naval Academy, 1873 ;
Instructor in Physics and Chemistry, ibid.,
1875-79 ; Nautical Almanac Office, Wash-
ington, 1880 ; University of Berlin, 1880 ;
University of Heidelberg, 1881 ; College
de France, ^cole Polytechnique, 1882 ;
Professor of Physics, Case School of Ap-
plied Science, Cleveland, 0., 1883-89;
Corresponding Member, British Associa-
tion for the Advancement of Science, 1884 ;
Associate Fellow of American Academy
of Arts and Sciences, 1885; Ph.D.
(Honorary) , Western Reserve University,
1886 ; and Stevens Institute, 1887 ; Vice-
President, American Association for the
Advancement of Science, ibid. ; Member
of National Academy of Sciences, 1888 ;
Rumford Medal, 1889 ; Professor of
Physics, Clark University, 1889-92 ;
Head Professor of Physics, University of
Chicago, 1892- ; Bureau International des
Poids et Measures, 1892-93; Member,
Soci^tg Frangaise de Physique, 1893 ; Fel-
low, Royal Astronomical Society, 1896 ;
Foreign Member, Soci^t^ Hollandaise des
Sciences, 1897 ; Honorary Member, Cam-
bridge Philosophical Society, ibid. ; Mem-
ber (for the United States) of the In-
ternational Committee of Weights and
Measures, ibid. ; Lowell Lecturer, 1899 ;
Sc.D. (Honorary), University of Cambridge
(England) ; Honorary Member Royal In-
stitute, 1899.
Author of : —
Experimental Determination of the Veloc-
ity of Light. Papers I. and II. Pi-oc.
A. A. A. 8., 1879 and 1880.
The Relative Motion of the Earth and
the Luminiferous Ether. Am. Jour,
of Sci., 1881, Vol. 22, pp. 120-129.
A New Sensitive Thermometer. Jou7'.
de Physique, 1882.
Interference Phenomena in a New Form
of Refractometer. Am. Jour, of Sci.,
May, 1882, Vol. 23, pp. 395-400.
A Method of Determining the Rate of
Tuning-Forks. Am. Jour, of Sci.,
Jan., 1883.
Experimental Determination of the Veloc-
ity of Light. Third Paper. Astron.
Papers, Nautical Almanac, Vol. 2.
Velocity of Light in Carbon Disulphide
and Velocity of Red and Blue Light
in Same. Ibid.
M. Wolf's Modification of Foucault's
Apijaratus for the Measurement of
the Velocity of Light. Nature, May 7,
1885, Vol. 32, pp. 6-7.
Influence of Motion of the Medium on
the Velocity of Light. Am. Jour, of
Sci., May, 1886, Vol. 31, pp. 377-386.
On the Relative Motion of the Earth and
the Luminiferous Ether. (With E.
W. Morley.) Philosophical Magazine,
5th ser., Dec, 1887, Vol. 24, pp.
449-463.
On a Method for Making the Wave
Length of Sodium Light the Actual
528
Titles of
and Practical Standard of Length.
(With E. W. Morley.) Am. Jour, of
Sci., Dec, 1887, Vol. 34, pp. 427-430.
Philosophical Magazine, 5th ser.,
Dec, 1887, Vol. 24, pp. 463-466.
On the Feasibility of Establishing a Light
Wave as the Ultimate Standard of
Length. (With E. W. Morley.) Am.
Jour, of Set, 3rd ser., Sept., 1889,
Vol. 38, pp. 181-186.
Measurement by Light Waves. Ihid.,
Feb., 1890, Vol. 39, pp. 115-121.
A Simple Interference Experiment. Ibid. ,
March, 1890, Vol. 39, pp. 216-218.
Application of Interference Methods to
Astronomical Measurements. Philo-
sophical Magazine, 5th ser., July, 1890,
Vol. 30, pp. 1-21.
Visibility of Interference Fringes in the
Focus of a Telescope. Ibid., March,
1891, Vol. 31, pp. 256-259.
Application of Interference Methods to
Spectroscopic Measurements. Ibid.,
April, 1891, Vol. 31, pp. 338-346.
Measurement of Jupiter's Satellites by
Interference. Mem. Astr. Soc. of the
Pacific, 1891.
Les m^lhodes interf^rentielles en mtool-
ogie et P^tablissement d'une longueur
d'onde comme unit6 absolue de
longueur. Bev. Gen. des Sciences, 30
Juin, 1893. Translation in Nature,
Nov. 16, 1893. Abstracts in Comptes
Eendiis and Soc. de Physique.
Determination exp^rimentale de la valeur
du mfetre en longueur d'ondes lumi-
neuses. Travaux et Memoires du
Bureau International des Poids et
3Iesures, Paris, 1895, Vol. 11, pp. 3-85.
On the Broadening of Spectral Lines by
Temperature and Pressure. Astro-
physical Journal, Nov., 1895.
On the Conditions which Affect the Spec-
trum Photography of the Sun. Ibid.,
Jan., 1895.
On the Limit of Visibility of Fine Lines
in a Telescope. Ibid., June, 1895.
The Relative Motion of the Earth and the
Ether. Am. Jour, of Sci., 4th ser.,
1897, Vol. 3. pp. 475-478.
Radiation in a Magnetic Field, Philo-
sophical Magazine, 5th ser., July, 1897,
Vol. 44, pp. 109-115.
A New Harmonic Analyser. (With S. W.
Strattou.) Am. Jour, of Sci., 4th
ser., Jan., 1898, Vol. 5, pp. 1-13.
A Spectroscope without Prisms or Grat-
ings. Ibid., 4th ser., March, 1898, Vol.
5, pp. 215-217.
Radiation in a Magnetic Field, Astro-
physical Journal, Feb., 1898.
The Echelon Spectroscope. Ibid., June,
1898.
Nouvelle M^thode de tracer et d' observer
des divisions de precision, form^es par
des traits lumiueux sur fond noir.
Travaux et Memoires du Bureau
International des Poids et Mesures,
Paris, 1899.
DICKINSON SERGEANT MILLEU :
University of Pennsylvania, 1885-88 ;
Fellow in Philosophy, Clark Univer-
sity, 1889-90 ; Morgan Fellow, Har-
vard University, 1890-91 ; Walker Fellow,
ibid., 1891-92 ; A.B. and A.M., ibid.,
1892 ; University of Berlin, 1892-93 ;
Ph.D., University of Halle, 1893; Asso-
ciate in Philosophy, Bryn Mawr College,
1893-98 ; Instructor, Harvard Univer-
sity, for the year 1899-1900 ; Member of
American Psychological Association.
Author of : —
The Meaning of Truth and Error. Phil-
osophical Bevieio, July, 1893, Vol. 2,
pp. 408-425.
The Confusion of Function and Content
in Mental Analysis. Proc. Am. Psy.
Ass''n, Dec, 1893, and Psychological
Beview, Nov., 1895, Vol. 2, pp. 535-
550.
The Relations of "Ought" and "Is."
Internat. Jour, of Ethics, July, 1894,
Vol. 4, pp. 499-512.
Desire as the Essence of Pleasure. Proc.
Am. Psy. Ass'n, Dec, 1894. Psycho-
logical Beview, March, 1895, Vol. 2,
pp. 164-165.
"The Will to Believe" and the Duty to
Doubt. Internat. Jorir. of Ethics,
Jan., 1899, Vol. 9, pp. 169-195.
Published Papers.
529
Professor James on Philosophical Method.
Philosophical Eevieio, March, 1899,
Vol. 8, pp. 166-179.
WILLIAM S. MILLER: —
M.l)., Yale Medical School, 1879; Prac-
tising Physician, ibid., 1879-86; College
of Physicians and Surgeons, New York,
1886-87 ; Lecturer in Microscopical Tech-
nique, Mt. Holyoke College, 1887-88 ;
Pathologist, City Hospital and Memorial
Hospital, Worcester, Mass., 1888-91;
Scholar in Anatomy, Clark Univer-
sity, 1889-91 ; Fellow, 1891-92 ; In-
structor in Biology, University of Wis-
consin, 1892-93 ; Instructor in Vertebrate
Anatomy, ibid., 1893-95 ; on leave of
absence. University of Leipzig, 1895-96 ;
Assistant Professor of Vertebrate Anat-
omy, University of Wisconsin, 1895- ;
Fellow, Massachusetts Medical Society,
Fellow, A. A. A. S. ; Member Anatomische
Gesellschaf t. Member Wisconsin Academy
of Arts and Sciences.
Author of : —
The Lobule of the Lung and its Blood-
vessels. Anat. Anzeiger, 1892, Vol. 7,
pp. 181-190.
The Structure of the Lung. Jour, of
Morph., April, 1893, Vol. 8, pp. 165-
188.
On the So-called Incas Eyes. Science,
Feb. 10, 1893, Vol. 21, pp. 74-75.
The Anatomy of the Lung. Bef. Hand-
book of the Med. Sciences, 1893, Vol.
9, pp. 571-576.
The Anatomy of the Heart of Cambarus.
Trails. Wis. Acad, of Sciences, Arts,
and Letters, 1895, Vol. 10, pp. 327-
338.
The Relation between the Cortex and
Medulla in the Cat's Kidney, and an
Estimation of the Number of Glumer-
uli. Ibid., pp. 525-538.
The Lymphatics of the Lung. Anat. An-
zeiger, June 4, 1896, Vol. 12, pp. 110-
114.
HALCOTT C. MORENO: —
A.B., University of Georgia, 1893 ; A.M.,
ibid., 1894; B.L., ibid., 1896; Tutor in
2m
Mathematics, ibid., 1893-97 ; Scholar
in Mathematics, Clark University
1897-98 ; Fellow, 1898-99.
SAMUEL P. MULLIKEN: —
S.B., Massachusetts Institute of Tech-
nology, 1887 ; Assistant in Chemistry,
University of Cincinnati, 1887-88 ; Gradu-
ate Student, University of Leipzig, 1888-
90; Ph.D., University of Leipzig, 1890;
Fellow in Chemistry, Clark Univer-
sity, Jan.-June, 1891 ; Associate in
Chemistry, Bryn Mawr College, 1891-92 ;
Instructor in Chemistry, Clark Uni-
versity, 1892-94 ; Research Assistant
to Professor Wolcott Gibbs, Newport,
R.I., 1894-95 ; Instructor in Organic
Chemistry, Massachusetts Institute of
Teclmology, 1895-.
Author oi : —
Ueber die Konstitution der Chlorzimmt-
sauren. (Inaugural-dissertation der
Universitat Leipzig.) Leipzig, 1890.
57 pp.
The Geometrical Isomerism of the Chlor-
cinnamic Acids. Technology Quar-
terly, 1891, Vol. 4, pp. 170-177.
A New Class of Organic Electrosyntheses.
Am. Chem. Jour., June, 1893, Vol. 15,
pp. 323-333.
Laboratory Experiments on the Class Re-
actions of Organic Substances and their
Identification. (With A. A. Noyes.)
First edition, 17 pp., Maclachlan,
Boston, 1896; second edition, 38 pp.,
1897, and third edition, 30 pp., 1898.
Chem. Publishing Company, Easton,
Pa.
A Simple Color Reaction for Methyl Al-
cohol. (With H. Scudder.) Am.
Chem. Jour., March, 1899, Vol. 21,
pp. 266-271.
Reactions for the Detection of the Nitro-
group. (With E. R. Barker.) Ibid.,
pp. 271-276.
F. "WILLIAM MUTHMANN: —
Assistant in Analytical Chemistry, Uni-
versity of Munich, 1884-86 ; Ph.D., Uni-
versity of Munich, 1886; Instructor in
530
Titles of
Chemistry and Crystallography, ihid.,
1887-89 ; Decent in Chemistry, Clark
University, 1889-91 ; Assistant in
Clieniistry, Academy of Science, Munich,
1891-94 ; Docent in Chemistry, University
of Munich, 1894-95 ; Professor of Inor-
ganic and Analytical Chemistry, ihid.,
1895-.
Author of : —
Ueber niedere Oxyde des Molybdans.
(Inaugural dissertation. ) Liebig^s An-
7ialen, 1887, Vol. 238, pp. 108-137.
Ueber Polymorphic und Mischkrystalle
einiger organischer Substanzen. Zeits.
f. Krystallographie, 1889, Vol. 15, pp.
60-79.
Krystallographisch-chemische Notizen.
Ibid., 1888, Vol. 15, pp. 387-403.
Krystallographische Untersuchung der
Phtalsaure, und einigen Derivate der-
selbeu. (With W. Ramsay.) Ibid.,
1889, Vol. 17, pp. 73-84.
Messelit, ein neues Mineral. Ibid., 18S9,
Vol. 17, pp. 93-94.
Untersuchungen liber den Schwefel und
das Selen. Ibid., 1890, Vol. 17, pp.
336-367.
Zur Frage der Silberoxydulverbindungen.
Ber. d. deuts. chem. Gesellschaft, 1887,
Vol. 20, pp. 983-990.
Krystallographische Untersuchung einiger
Derivate der Terephtalsaure. Zeits. f.
Krystallographie, 1890, Vol. 17, pp.
460-483.
Ueber Isomorphimus einiger organischer
Substanzen. Ibid., 1891, Vol. 19, pp.
357-367.
Bemerkung liber den rothen Phosphor,
Zeits. f. anorg. Chemie, 1893, Vol, 4,
pp. 303-304.
Untersuchungen liber das Selen. (With
Dr. J. Schafer.) Ber. d. debits, chem.
Gesellschaft, 1893, Vol. 26, pp. 1008-
1016.
Eine bequeme Methode zur Darstellung
von Baryumpermanganat. Ibid., pp.
1016-1018.
Ueber die Reindarstellung von Rubidium-
salzen. Ibid., pp. 1019-1020.
Berichtigung. Ibid., pp. 1425-1426.
Beitrage zur Volumtheorie der Krystalli-
sirten Korper. Zeits. f. Krystallogra-
phie, 1894, Vol. 22, pp. 497-551.
Ueber die Loslichkeit der MischkrystaUe
einiger isomorpher Salzpaare. (With
Dr. O. Kuntze.) Ibid., 1894, Vol. 23,
pp. 368-378.
Ueber den sogenannten Schneebergit.
Ibid., 1895, Vol. 24, pp. 583-586.
Schwefelstickstoff. Ber. d. deuts. chem.
Gesellschaft, 1896, Vol. 29, pp. 340-
343.
Zur quant. Best, und Scheidung des Kup-
fers. Zeits. f. anorg. Chemie, 1896,
Vol. 11, pp. 268-271.
Ueber einige Verbindungen des Phosphors
und Selens. Ibid., Vol. 13, pp. 191-199,
Stickstoffpentasulfid. Ibid., Vol. 13, pp.
200-208.
Loslichkeit des Schwefels Ceroxyduls in
Wasser. Ibid., 1897, Vol. 16, pp. 450-
462.
ZusammensetzTing einiger Tellurminera-
len. Zeits. f. Krystallographie, 1898,
Vol. 29, pp. 140-145.
Ueber Permolydate. Zeits. f. anorg.
Chemie, 1898, Vol. 17, pp. 73-81.
Also Ber. d. deuts. chem. Gesellschaft,
1898, Vol. 31, pp. 1836-1844.
Doppelthiosulfate von Kupfer und Ka-
lium. Ber. d. deuts. chem. Gesell-
schaft, 1898, Vol. 31, pp. 1732-1735.
JOHN U. NEF: —
A.B., Harvard University (with Honors
in Chemistry), 1884; Kirkland Fellow,
ibid., 1884-87; University of Munich,
1884-87 ; Ph.D., University of Munich,
1886 ; Professor and Director of Chemical
Laboratory, Purdue University, 1887-89 ;
Assistant Professor of Chemistry,
Clark University, 1889-92; Professor of
Chemistry and Director of the Kent Chemi-
cal Laboratory, University of Chicago,
1892-96 ; Head Professor of Chemistry
and Director of the Kent Chemical Lab-
oratory, ibid., 1896-.
Author of : —
The Volumetric Determination of Com-
bined Nitrous Acid. (With Dr. Kin-
Published Papers.
531
nicutt.) Am. Chem. Jour., Nov. 1883,
Vol. 5, pp. 388-389.
Ueber einige Derivate des Durols. Ber.
d. deuts. chem. Gesellschaft, 1885, Vol.
18, pp. 2801-2807.
Ueber Benzochinoncarbonsauren. Ibid.,
pp. 3496-3499.
Ueber Benzochinoncarbonsauren. Lie-
big's Annalen, 1887, Vol. 237, pp. 1-
39.
Ueber Py-3-Phenylchinaldinsaure und
Py-3-Phenylchinolin. (With Dr. Koe-
nigs.) Ber. d. dents, chem. Gesell-
schaft, 1886, Vol. 19, pp. 2417-2432.
Ueber des Py-3-Phenylchinolin und Py-
3-B-Dichinolyle. (With Dr. Koenigs. )
Ibid., 1887, Vol. 20, pp. 622-636.
Notiz iiber die Cinchoninsaure. (With
W. Muthmann. ) Ibid. , 1887, Vol. 20,
pp. 636-638.
Nitranilsaure aus Chloranil. Ibid., 1887,
Vol. 20, pp. 2027-2031.
On Tautomeric Compounds. Part I.
Am. Chem. Jour., Jan., 1889, Vol.
11, pp. 1-17.
The Constitution of the Anilic Acids.
Ibid., pp. 17-26.
Ueber tautomere Korper. Liebig''s An-
nalen, 1890, Vol. 258, pp. 261-318.
Die Constitution des Benzochinons.
Jour. f. praktische Chemie, 1890, Vol.
42, pp. 161-188.
On Tautomeric Compounds. Part II.
Am. Chem. Joicr., June, 1890, Vol. 12,
pp. 379-425.
The Constitution of Benzoquinone. Part
I. Ibid., July, 1890, Vol. 12, pp.
463-488.
Zur Kenntniss des Acetessigathers. Lie-
big'' s Annalen, 1891, Vol. 266, pp.
52-138.
The Constitution of Benzoquinone. Part
II. Am. Chem. Jour., June, 1891,
Vol. 13, pp. 422-428.
Ueber das zweiwerthige Kohlenstoffatom.
Erste Abh. Liebig's Annalen, 1892,
Vol. 270, pp. 267-335. Also in Proc.
of Am. Acad, of Arts and Sciences, on
Bivalent Carbon, for 1892, Vol. 27,
pp. 102-162.
Zur Kenntniss des Acetessigathers. Lie-
big^s Annalen, 1893, Vol. 276, pp.
200-245.
Ueber die 1.3 Diketone. Ibid., 1893, Vol.
277, pp. 59-78.
Ueber die Constitution der Salze der
Nitroparaffine. Ibid., 1894, Vol. 280,
pp. 263-291. Also in Proc. of Am.
Acad, of Arts and Sciences, 1894, Vol.
29, pp. 124-150.
Ueber das zweiwerthige Kohlenstoffatom.
Zweite Abh. Liebig''s Annalen, 1894,
Vol. 280, pp. 291-342. Also in Proc.
of Am. Acad, of Arts and Sciences,
1894, Vol. 29, pp. 151-193.
Ueber das zweiwerthige Kohlenstoffatom.
Dritte Abh. Die Chemie des Cyans
und des Isocyans. Liebig's Annalen,
1895, Vol. 287, pp. 265-359.
Ueber das zweiwerthige Kohlenstoffatom.
Vierte Abh. Die Chemie des Me-
thyleus. Ibid., 1897, Vol. 298, pp.
292-374.
Notiz iiber die Formhydroxamsaure. Ber.
d. deuts. chem. Gesellschaft, 1898, Vol.
31, pp. 2720-2721.
Ueber das Phenylacetylen, seine Salze,
und seine Halogen Substitutions Pro-
dukte. Liebig's Annalen der Chemie,
1899, Vol. 308, pp. 264-328.
Ueber das Verhalten der tri- und tetra-
halogen-substituirten Methane. Ibid.,
1899, Vol. 308, pp. 329-333.
Dissociationsvorgange bei den Alkyla-
theon der Saltpetersaure, der Schwe-
felsaure und der Halogeuwasserstoff-
sauren. Ibid., 1899, Vol. 309, pp.
126-189.
HERBERT NICHOLS:—
B.S., Worcester Polytechnic Institute,
1871 ; Fellow in Psychology, Clark
University, 1889-91 ; Ph.D., Clark
University, 1891 ; Instructor in Psy-
chology, Harvard University, 1891-93 ;
Lecturer in Psychology, Johns Hopkins
University, 189o-96; Member American
Society of Naturalists, 1890 ; Member
American Psychological Association, 1892.
Author of : —
The Psychology of Time. Am. Jour, of
Psy., Feb., 1891, Vol. 3, pp. 453-529 ;
532
Titles of
April, 1891, Vol. 4, pp. 60-112. Henry
Holt & Co., N. Y., 1891, 140 pp.
The Origin of Pleasure and Pain. Philo-
sophical Beview, July, 1892, Vol.1 .,pp.
403-432; Sept., 1892, Vol. 1., pp. 518-
534.
Experiments upon Pain. Beport First An.
Mtg. Am. Psy. ^ssre., Dec, 1892. Mac-
millan&Co., N. Y., 1894.
Perceptions of Kotation. Ibid., Dec, 1892.
Macmillan & Co., N. Y., 1894.
Primarj^ Education. Beport Special Cor-
respondence, Feb., 1893. Educational
Club, Philadelphia, 1893.
The Harvard Psychological Laboratory.
McCliu-e's Magazi}ie, Oct., 1893,Vol. 1,
pp. 399-409.
The Promise in Mental Science. Ibid.,
Jan., 1894, Vol. 2, pp. 202-203.
Beitrage zur Psychologie des Zeitsinns,
and Untersuchungen zur Psychologie
und jEsthetik des Rhythmus. By
Ernst Meumann. Review. Psycho-
logical Beview, Nov., 1894, Vol. 1, pp.
638-641.
Our Notions of Number and Space. Ginn
& Co., Boston, 1894. 201 pp.
The Motor Power of Ideas. Philosophical
Beview, March, 1895, Vol. 4, pp. 174-
185.
William James. (Biographical Sketch.)
The Book Buyer, March, 1895, Vol. 12,
pp. 61-63.
The "Feelings." Philosophical Beview,
Sept., 1895, Vol. 4, pp. 506-530.
Pain Nerves. (Discussion.) Psychologi-
cal Beview, Sept., 1895, Vol. 2, 487-
490.
Psychology and Education. The Citizen,
Dec, 1895, Vol. 1, pp. 229-230. Uni-
versity Extension Study, Philadelphia.
Pain Nerves. (Discussion.) Psychologi-
cal Beview, May, 1896, Vol. 3, pp. 309-
313.
Fear. By Angelo Mosso. Review. Ibid.,
July, 1896, Vol. 3, pp. 445-447.
Ueber Raumwahrnehmungen im Gebiete
des Tastsinnes. By Chas. Hubbard
Judd. Review. Ibid., Sept., 1896,
Vol. 3, pp. 577-578.
Professor Baldwin's New Factor in Evo-
lution. Tlie American Naturalist,
Sept., 1896, Vol. 30, pp. 697-710.
Further Comments on Professor Baldwin's
New Factor in Evolution. Ibid.,
Nov., 1896, Vol. 30, pp. 951-954.
The Biologic Origin of Mental Variety, or
How We came to Have Minds. Ibid.,
Dec, 1896, Vol, 30, pp. 963-975; Jan.,
1897, Vol. 31, pp. 3-16.
The Psycho-Motor Problem. Am. Jour.
of Insanity, July, 1897, Vol. 54, pp. 59-
80.
Psychology and Physiology. Ibid., Oct.,
1897, Vol. 54, pp. 181-200.
The Psychology of the Emotions. By
Th. Ribot. Review. Ibid. , Oct. , 1S97 ,
Vol. 54, pp. 266-270.
Hallucinations and Illusions. By Ed-
mund Parish. Review. Ibid., Jan.,
1898, Vol. 54, pp. 472-474.
The New Psychology. By E. W. Scrip-
ture. Review. Ibid., Jan., 1898,
Vol. 54, pp. 474-475.
The Psychology of Suggestion. By Boris
Sidis. Review. Ibid., April, 1898,
Vol. 54, pp. 643-644.
The Genesis and Dissolution of the Fac-
ulty of Speech, By Joseph Collins.
Review. Ibid., July, 1898, Vol. 55.
p. 184.
THOMAS F. NICHOLS: —
A.B., Bowdoin College, 1892 ; Scholar in
Mathematics, Clark University, 1892-
93; FeUow, 1893-95; Ph.D., Clark
University, 1895 ; Assistant in Mathe-
matics, University of Wisconsin, 1895-96;
Assistant Professor of Mathematics, Ham-
ilton College, 1896-.
Author of : —
On Some Special Jacobians. Mathemati-
cal Beview, July, 1896, Vol, 1, pp.
60-80.
On the Generation of Certain Curves of the
Fifth and Sixth Orders. Ibid., April,
1897,Vol. 1, pp. 141-153.
ARTHUR A. NOTES: —
S.B., Massachusetts Institute of Tech-
nology, 1886; S.M., ibid., 1887 ; Assistant
Published Papers.
533
in Chemistry, ibid., 1887-88; Ph.D.,
University of Leipzig, 1890 ; Instructor in
Chemistry, Massachusetts Institute of
Technology, 1890-93 ; Non-resident
Lecturer in Physical Chemistry, Clark
University, 1892-94 ; Assistant Pro-
fessor of Chemistry, Massachusetts Insti-
tute of Technology, 1893-97 ; Associate
Professor of Organic Chemistry, ihid.,
1897-99; Professor of Theoretical and Or-
ganic Chemistry, ihid., 1899-.
Author of : —
On the Action of Heat upon Ethylene.
(With L. M. Norton.) Am. Chem.
Jour. Oct., 1886, Vol. 8, pp. 362-
364.
The Constitution of Benzol. Technology
Quarterly, 1887, Vol. 1, pp. 79-90.
On the Action of Heat on Isobutylene.
Ibid., pp. 278-281.
Note on the Butines. (With L. M. Nor-
ton.) Am. Chem. Jour., Nov., 1888,
Vol. 10, pp. 430-433.
An Index to the Literature of the Butines
and their Halogen Addition Products.
Technology Quarterly, 1888, Vol, 2,
pp. 112-122.
Ueber die Abweichungen von den Gasge-
setzen in Losungen. Zeits. f. physik.
Chemie, 1890, Vol. 5, pp. 53-67.
Ueber die gegenseitige Beeinflussung der
Loslichkeit von dissociierten Korpern.
Ibid., 1890, Vol. 6, pp. 241-267.
Ueber vermehrte Loslichkeit. Anwen-
dung der Gefrierpunktsbestimmungen
zur Ermittelung der Vorgange in
Losung. Ibid., 1890, Vol. 6, pp. 385-
402.
Ueber die Bestimmung der elektrolyti-
schen Dissociation von Salzen mittels
Loslichkeitsversuche. Ibid., 1892,
Vol. 9, pp. 603-632. Translation in
Technology Quarterly, 1891, Vol. 4,
pp. 259-291.
Ueber die WasserstoflBonabspaltung bei
den sauren Salzen. Ibid., 1893, Vol.
11, pp. 495-500. Translation in Tech-
nology Quarterly, 1892, Vol. 5, pp. 342-
349.
Influence of the Introduction of a Sul-
phonic Acid Group upon the Power of
a Developer. (With W. K. Gaylord.)
Technology Quarterly, 1893, Vol. 6, pp.
60-61.
Ueber die elektrolytische Reduction des
Nitrobenzols in Schv?efelsaurelosung.
(With A. A. Clement.) Ber. d. deuts.
chem. Gesellschaft, 1893, Vol. 26, pp.
990-992. Translation in Technology
Quarterly, 1893, Vol. 6, pp. 62-64.
Ueber die Bestimmung der elektrolyti-
schen Dissociation von Salzen mittels
Loslichkeitsversuche. Zeits. f. phy-
sik. Chemie, 1893, Vol. 12, pp. 162-166.
Translation in Technology Quarterly,
1893, Vol. 6, pp. 237-240.
Loslichkeit des sauren Kaliumtartrats
bei Gegenvrart anderer Salze. (With
A. A. Clement.) Zeits. f. physik.
Chemie, 1894, Vol. 13, pp. 412-416.
Die WasserstoflBonabspaltung bei dem
sauren Kaliumtartrat. Zeits. f. physik.
Chemie, 1894, Vol. 13, pp. 417-418.
Kryoskopische Untersuchungen mit Alu-
minaten und Boraten von Alkalime-
tallen. (With W. R. Whitney.) Ibid.,
1894, Vol. 15, pp. 694-698.
The Electrolytic Reduction of Paranitro-
benzoic Acid in Sulphuric Acid Solu-
tion. (With A. A. Clement.) Am.
Chem. Jour., Nov., 1894, Vol. 16, pp.
511-513.
Eine Priif ung der Principe der Loslichkeits-
beeinflussung und ein Vergleich der
daraus imd aus der elektrischen Leit-
fahigkeit berechneten Dissociations-
werte. (With C. G. Abbot.) Zeits.f.
physik. Chemie, 1895, Vol. 16, pp.
125-138. Translation in Technology
Quarterly, 1895, Vol. 8, pp. 47-62.
Die Geschv?indigkeit der Reaktion
zwischen Zlnnchloriir und Eisen-
chlorid. Eine Reaktion dritter Ord-
nung. Zeits. f. physik. Chemie, 1895,
Vol. 16, pp. 546-561.
Synthesis of Diphenylbiphenyl and its
Identilication as Benzerythrene.
(With Rolfe M. Ellis.) Am. Chem.
Jour., Oct., 1895, Vol. 17, pp. 620-622.
Also in Technology Quarterly, 1895,
Vol. 8, pp. 178-180.
534
Titles of
Die Geschwindigkeit der Hydrolyse des
Salicins durch Sauren. (With W. T.
Hall.) Zeits.f. physik. Chejnie, 1895,
Vol. 18, pp. 240-2-44, Translation in
Technology Quarterly, 1895, Vol. 8,
pp. 283-293.
Beitrag zur Kenntniss der Gesetze der
Geschwindigkeit von polymolekiilaren
Reaktionen. (With W. O. Scott.)
Zeits. f. physik. Chcmie, 1895, Vol.
18, pp. 122-132.
The Electrolytic Reduction of Paranitro
Compounds in Sulphuric Acid Solu-
tion. (With J. T. Dorrance.) Ber.
der deuts. chem. Gesellschaft, 1896,
Vol. 28, pp. 2349-2352. Translation
in Jour. Am. Chem. Soc, 1895, Vol,
17, pp. 855-859.
The Occurrence of Trimethylene Glycol as
a By-product in the Glycerine Manu-
facture. (With W, H. Watkins.)
Jour. Am. Chem. Soc, 1895, Vol.
17, pp. 890-891. Also Technology
Quarterly, 1895, Vol. 8, pp. 261-
262.
Die katalytische Wirkung der Wasser-
stoffjonen auf polymolekulare Reak-
tionen. Zeits. f. physik. Chemie,
1896, Vol. 19, pp. 599-606.
Bemerkung iiber das Gesetz der Ge-
schwindigkeit der Reaktion zwischen
Eisenchlorid und Zinnchloriir, Ibid.,
1896, Vol. 21, p, 16.
Die innere Reibung des Quecksilber-
dampfes. (With H, M. Goodwin.)
Ibid., 1896, Vol. 21, pp, 671-679.
Translation in Physical Beview, Nov.-
Dec, 1896, Vol. 4, pp. 207-216.
Sind Diphenyljodonium- und Thallium-
nitrat isomorph? (With C. W. Hap-
good, Zeits. f. physik. Chemie, 1896,
Vol. 22, pp. 464-465.
Instruction in Theoretical Chemistry.
Technology Qiiarterly, 1896, Vol. 9,
pp. 323-325.
Formation of Diacetylenyl (Butadiine)
from Copper Acetylene. (With C.
W. Tucker.) Am. Chem. Jour., Feb.
1897, Vol. 19, pp. 123-128,
Synthesis of Hexamethylene-Glycol Di-
ethyl Ether and Other Ethers from
Trimethylene Glycol. Ibid., Nov.,
1897, Vol. 19, pp. 766-781.
Die Reaktionsgeschwindigkeit zwischen
Eisenchloriir, Kaliuuichlorat und Salz-
saure. (With R. S. Wason,) Zeits.
f. ijhysik. Chemie, 1897, Vol. 22, pp.
210-221. Translation in Jour. Am.
Chem. Soc, 1897, Vol. 19, pp. 199-
213.
Bestimmung des osmotischen Druckes mit-
tels Dampfdruckmessungen. (With C.
G. Abbot.) Zeits. f. physik. Chemie,
1897, Vol. 23, pp. 56-77.
Ueber die Auflosungsgeschwindigkeit von
festen Stoffen in ihren eigenen Lo-
sungeu. (With W. R. Whitney.)
Ibid., pp. 689-692. Translation in
Jour. Am. Chem. Soc, 1897, Vol. 19,
pp. 930-934.
Bemerkung iiber die Kinetische Theorie
derLosungen. Zeits. f. physik. Chemie,
1897, Vol. 24, p. 366.
Qualitative Chemical Analysis. The Mac-
millan Co., N. Y., 1897. 89 pp.
Third edition.
Laboratory Experiments on the Class
Reactions and Identification of Organic
Substances. (With S. P. Mulliken.)
Chemical Publishing Co., Easton, Pa.,
1897. 31 pp. Second edition.
Investigation of the Theory of Solubility
Effect in the case of Trionic Salts,
(With E. H. Woodworth. ) Jour. Am.
Chem. Soc, 1898, Vol. 20, pp. 194-
201. Also Zeits. f. physik. Chemie,
1898, Vol. 26, pp. 152-158.
The Reliability of the Dissociation Values
Determined by Electrical Conductivity
Measurements. Jour. Am. Chem.
Soc, 1898, Vol. 20, pp. 517-528. Also
Zeits. f. physik. Chemie, 1898, Vol.
26, pp. 699-710.
The Solubility of Salts of Weak Acids
in Stronger Acids. (With David
Schwartz.) Jour. Am. Chem. Soc,
1898, Vol, 20, pp. 743-751. Also Zeits.
f. physik. Chemie, 1898, Vol. 27, pp.
279-284.
Die Theorie der Loslichkeitsbeeinflussung
bei zweiioningen Electrolyten mit
lauter verschiedenen Jonen. Zeits.
Published Papers.
635
/. physik. Chemie, 1898, Vol. 27, pp.
267-278.
The Solubility of Acids in Solutions of the
Salts of Other Acids. (With E. S.
Chapita.) 7 fciVZ., pp. 442-446. Trans-
lation in Jour. Am. Chem. Soc, 1898,
Vol. 20, pp. 751-756.
Die Loslichkeit von Jod in verdiinnten
Kaliumjodidlosungen. (With L. J.
Seidensticker. ) Zeits. f. physik.
Chemie, 1898, Vol. 27, pp. 357-360.
Translation in Jb?«r. Am. Chem. Soc,
1899, Vol. 21, pp. 217-220.
Die Geschwindigkeit der Reaktion zwischen
Silberacetat iind Natriumformiat.
Eine Reaktion dritter Ordnung. (With
G. T. Cottle. ) Zeits. f. physik. Chemie,
1898, Vol. 27, pp. 579-584.
Die Beziehung zwischen osmotischer Ar-
beit und osmotischem Druck. Ibid.,
1899, Vol. 28, pp. 220-224.
C. A. ORR: —
A.B., University of Michigan, 1887; Stu-
dent, Johns Hopkins University, 1887-88 ;
Principal, High School, Salem, O., 1888-
89 ; Anthropologist, Solar Eclipse
Expedition, Clark University, 1889-
90 ; Lecturer in Latin, University of
Chicago, 1892- ; Instructor, Chicago High
Schools, 1894-.
VICTOR PAPCKE: —
Ph.D., University of Gottingen, 1888;
Assistant in Chemistry, Clark Univer-
sity, 1889-90 ; Medical Student, Uni-
versity of Leipzig, 1893.
GEORGE E. PARTRIDGE: —
Special Student in Philosophy, Clark
University, 1895-96 ; Scholar in Psy-
chology, 1896-98 ; FeUow, 1898-99.
Author of: —
Second Breath. Pedagogical Seminary,
April, 1897, Vol. 4, pp. 372-381.
Blushing. Ibid., April, 1897, Vol. 4, pp.
387-394.
Some Mental Automatisms. (With E. H.
Lindley.) Ibid., July, 1897, Vol. 5,
pp. 41-60.
Reverie. Ibid., April, 1898, Vol. 5, pp.
445-474.
Child Study in Connection with the Va-
cation Schools. (With H. S. Curtis.)
Report on the Vacation Schools and
Playgrounds, N. Y. City, Borough of
Manhattan and the Bronx, 1898, pp.
51-97.
Experiments upon the Control of the
Reflex. Am. Jour, of Psy. (In
press.)
T. RICHARD PEEDE: —
Christian Biblical Institute, New York,
1881-84; Boston University, 1884-85;
Special Student in Philosophy and
Pedagogy, Clark University, 1895-96 ;
Honorary Scholar in Philosophy,
1896-97 ; Pastor, South Baptist Church,
Worcester, 1895-.
JOSEPH DE PEROTT: —
Universities of Paris and Berlin, 1877-80 ;
Decent in Mathematics, Clark Uni-
versity, 1890-.
Author of: —
Sur la sommation des nombres. Bull, des
Sci. Mathematiques, 1881, 2d ser. , Vol.
5, pp. 37-40.
Sur l'infinit6 de la suite des nombres pre-
miers. Ihid., pp. 183-184.
Sur une arithm^tique espagnole du 16™^
si^cle. Bull, di bibliografia e di storia
delle scienze matematiche, 1882, Vol,
15, pp. 163-170.
Sur la recherche des diviseurs des fonc-
tions entiferes. Bull, de la Soc. Mathe-
matique, 1882, Vol. 10, pp. 250-251.
Sur un th^or^me de Gauss. Ibid., pp. 87-
88.
Sur la formation des determinants irr^gu-
liers. Jour. f. Mathematik, 1883,
Vol. 95, pp. 232-237.
Sur le problfeme des fous. Bull, de la Soc.
Mathematique, 1883, Vol. 11, pp. 173-
186.
Sur la formation des determinants irr^gu-
liers. Second M6moire. Jour. f.
Mathematik, 1884, Vol. 96, pp. 327-
348.
536
Titles of
Demonstration du th^orfeme fondamental
de I'algfebre. Ihid., 1885, Vol. 99, pp.
141-160.
Demonstration de I'existence des racines
primitives pour les modules 6gaux k
des puissances de nombre premier im-
pair. Bull, des Set. Mathematiques,
1885, 2^ s^r., Vol. 9, pp. 21-24.
Sur les logarithmes h un grand nombre de
d^cimales et en particulier sur les Ta^
bles de Steinliauser. Ibid., 1887, 2«
ser.. Vol. 11, pp. 51-60.
Sur requation t2 — Du2 = —1. Jour,
f. Mathematik, 1888, Vol. 102, pp. 185-
223.
Eemarque au sujet du th^orfeme d'Euclide
sur r infinite du nombre des nombres
premiers. Am. Jour, of Mathematics,
1888, Vol. 11, pp. 99-138 ; 1891, Vol.
12, pp. 235-308.
Sur une proposition empirique enonc^e au
Bulletin. B\dl. de la Soc. Mathema-
tique, 1889, Vol. 17, pp. 155-156,
On a Theorem of Gauss. J. H. U. Circu-
lar, 1889, No. 78, p. 30.
The Gaussian Interpolation Theory, for-
mulge for ?i = 7, 8, 9. Quar. Jour, of
Mathematics, 1891, Vol. 25, pp. 200-
202.
Sur les groupes de Galois. Btill. de la
Soc. Mathematique, 1893, Vol. 21, pp.
61-65.
Demonstration de Pexistence de racines
primitives pour tout module premier
impair. Bull, des Set. Mathematiques,
1893, 2« ser., Vol. 17, pp. 66-83.
Demonstration de I'existence de racines
primitives module premier impair.
Ibid., 1894, 2e ser.. Vol. 18, pp. 64-66.
Mathematical Tables. Sci. Am. Supple-
ment, July 7, 1894, Vol. 38, pp. 15436-
15437.
The Theory of Numbers. (Review of M.
Stieltjes's "Sur la theorie des nom-
bres,") Bull, of Am. Math. Soc,
June, 1895, Vol. 1, pp. 217-232.
DANIEL EDWARD PHILLIPS: —
Graduate West Virginia State Normal
School, 1890 ; Principal, Public Schools,
Philippi, W. Va., 1890-91; A.B., Uni-
versity of Nashville, 1893; A.M., ibid.,
18!)4 ; Scholar in Psychology, Clark
University, 1894- March, 1895 ; Pro-
fessor of I'edagogy, Normal Department,
University of Georgia, March, 18'.t-')-Jan.,
1897 ; Honorary Scholar in Psychol-
ogy, Clark University, Jan.-TJune,
1897; Fellow, 1897-98; Ph.D.,
Clark University, 1898 ; Professor of
Philosophy and Education, University of
Denver, 1898-.
Author of : —
The End of Education. 22 pp.
Eeligious Education. Peabody Becord,
Nov., 1893, Vol. 4, pp. 5:5-60.
Courses of Study for Common Schools,
Southern Jour, of Ed., Oct., 1896,Vol.
9, pp, 472-478.
Genesis of Number Forms. Am. Jour, of
Psy., July, 1897, Vol. 8, pp. 506-527.
Number and its Application psychologi-
cally considered. Pedagogical Sem-
inary, Oct., 1897, Vol. 5, pp. 221-282.
Some Remarks on Number and its Appli-
cation. Ibid., April, 1898, Vol, 5, pp.
590-599.
Some Aspects of the Child Study Move-
ment. Northwestern Monthly, Jan.,
1899, Vol. 9, pp. 233-237.
The Teaching Instinct. Pedagogical Sem-
inary, March, 1899, Vol. 6, pp. 188-
246.
Sunday-School Teaching. Study, March,
1899, Vol. 4, pp. 309-313.
JEFFERSON R. POTTER: —
A.B., Brown University, 1877 ; A.M.,
ibid., 1887; Instructor, Vermont Academy,
1877-78; State Normal School, Castine,
Me., 1878-85; Professor of Pedagogy,
State College of Kentucky, 1885-88 ; In-
structor in Natural Sciences, State Nor-
mal School, Farmington, Me.. 1888-90;
Scholar in Psychology, Clark Uni-
versity, 1890-91 ; Superintendent of
Schools, Ashland and Hopkinton, Mass.,
1891-92 ; Superintendent of Schools, Wal-
pole, Foxboro, and Norfolk, Mass., 1892-
95 ; Superintendent of Schools, Walpole
and Foxboro, Mass., 1895-98 ; Member :
Published Papers.
537
New England Conference of Educational
"Workers ; New England Association of
School Superintendents.
Author of : —
History of Methods of Instruction in
Geography. Pedagogical Seminary,
Dec, 1891, Vol. 1, pp. 415-424.
J. O. QUANTZ: —
B.A., University of Toronto (Honors in
Philosophy and Psychology), 1894 ; Fel-
low in Psychology, University of Wiscon-
sin, 1895-97 ; Ph.D., University of Wis-
consin, 1897 ; Honorary Fellow in Psy-
chology, Clark University, 1897-98 ;
Honorary Fellow in Philosophy, Cornell
University, 1898-99.
Author of: —
The Influence of the Color of Surfaces on
our Estimation of their Magnitude.
Am. Jour, of Psy., Oct., 1895, Vol. 7,
pp. 26-41.
Problems in the Psychology of Reading.
Psychological Bevieio, Monograph Sui>
plement, Dec, 1897, pp. 1-51.
The Physiology of Shorthand. Phono-
graphic World, March, 1898, Vol. 13,
pp. 292-293.
Dendro-psychoses. Am. Jour, of Psy.,
July, 1898, Vol. 9, pp. 449-506.
An Analysis of the Muscular Sensations
involved in Drawing a Line.
HOLLA R. RAMSEY: —
Assistant in Shop, Indiana University,
1894-95; A.B., Department of Physics,
ibid., 1895; A.M., ibid., 1898; Science
Teacher, Decatur, Ind., High School,
1895-96 ; Laboratory Assistant, Indiana
University, 1896-97 ; Professor of Physics,
Westminster College, 1897-98 ; Scholar
in Physics, Clark University, 1898-
99 ; Assistant in Physics, Cornell Univer-
sity, 1899-.
Author of : —
A Photographic Study of Electrolytic
Cells. Physical Beview, Sept., 1899,
Vol. 9, pp. 189-190, 1 pi.
JOHN F. REIGART: —
A.B., Dickinson College, 1888 ; Principal
of High School, Chester, Pa., 1888-90;
Scholar in Psychology, Clark Univer-
sity, 1890-91 ; Associate Professor in
Education, Teachers' College, New York
City, 1891-92 ; Professor of Psychology
and History of Education, ibid., 1892-97 ;
Superintendent Workingman's School,
New York City, 1897-.
Author of : —
The Training of Teachers in England.
Pedagogical Seminary, Dec, 1891,
Vol. 1, pp. 409-415.
ERNEST -W. RETTGER: —
Graduate, Indiana State Normal School;
1891; A.B., Indiana University, 1893;
Principal, Rensselaer, Ind., High School,
1893-94 ; Instructor in Mathematics, Indi-
ana University, 1894-95 ; Fellow in
Mathematics, Clark University, 1895-
98; Ph.D., Clark University, 1898;
Instructor in Mathematics, Indiana Uni-
versity, 1898-.
Author of : —
Note on the Projective Group. Proc. Am.
Acad, of Set, July, 1898, Vol. 33, pp.
491-499.
On Lie's Theory of Continuous Groups.
Am. Jour, of Math. (In press.)
ROBERT J. RICHARDSON :-
Teacher in Public Schools, Varna, Ont.,
1887-90 ; Graduate, Ontario School of
Pedagogy, 1891 ; Student at Toronto Uni-
versity, 1892-93 ; Teacher in High School,
Prescott, Ont., 1893-94 ; B.A., University
of Toronto, 1897 ; Graduate Student,
ibid., 1897-98 ; Fellow in Psychology,
Clark University, 1898-99.
Author of : —
A case of Abnormal Color-Sense exam-
ined with Special Reference to the
Space-Threshold of Colors. (With J.
W. Baird.) Univ. of Toronto Studies,
Psychological Series, 1898, pp. 87-
100.
538
Titles of
CAMILLE RIED: —
Protestaut School, Freiburg, Baden, 1850-
52 ; Classical Gymnasium, Lahr, Baden,
1852-00 ; Student in Paris, 1862-63 ; Resi-
dent in Paris, 1862-65, and 1867-70;
Resident in Spain, 1865-67 ; Student in
Freiburg, 1870-71 ; Student in Boston,
1881-86 ; Head of School of Languages,
Boston, 1887-90 ; Instructor in Modern
Languages, Clark University, 1889-
91 ; Instructor, Nautical School, U. S. S.
Enterprise, 1891-94.
STANLEY H. ROOD : —
S.B., Worcester Polytechnic, in Mechan-
ical Engineering, 1890 ; in Electrical En-
gineering, 1891 ; Instructor in Physics,
ihid., 1890-93; Scholar in Physics,
Clark University, Sept., 1893- April,
1894 ; Instructor in Joinery, Mechanic
Arts High School, Boston, April-June,
1894 ; Instructor in French, ihid.^ 1894-
96 ; Graduate Student, Harvard Univer-
sity, 1895-96; Instructor in Joinery,
Manual Training High School, Worcester,
1896-.
ERWIN W. RUNKLE: —
A.B., Western College, 1890; Graduate
Student in Psychology and Philosophy,
Yale University, 1890-93 ; Lecturer in the
History of Philosophy, ibid., 1892-93;
Ph.D., Yale University, 1893; Assistant
Professor of Psychology and Ethics, Penn-
sylvania State College, 1893-99 ; Honor-
ary Fellow in Psychology, Clark
University, Jan.-June, 1899 ; Professor
of Psychology and Ethics, Pennsylvania
State College, 1899-.
Author of : —
Education and Life. Free Lance, State
College, Pennsylvania, Jan., 1894, Vol.
13, pp. 96-98.
Why do we Dream? J&id, Oct. 1895,
Vol. 14, pp. 5-8.
Factors in Education. Ibid., May, 1896,
Vol. 15, pp. 12-18.
Psychology and the Modem Novel. School
Gazette, June, 1897, Vol. 8, pp. 8-12.
Review of Breuer and Freud : Studien
iiber Hysterie. Am. Jour, of Psy.,
July, 1899, Vol. 10, pp. 592-594.
S. EDWARD RYERSON: —
M.A., Queen's University, 1895 ; Fellow
in Mathematics, Clark University,
1895-96.
Died, March 25, 1896.
EDMUND C. SANFORD: —
A.B., University of California, 1883;
Teacher in Oahu College, Hawaiian Is-
lands, 1883-85 ; Student, Johns Hopkins
University, 1885-88 ; University Scholar,
ibid., 1887 ; Fellow, ibid., 1887-88 ; Ph.D.,
Johns Hopkins University; 1888 ; Instruc-
tor in Psychology, ibid., 1888-89 ; Instruc-
tor in Psychology, Clark University,
1889-92 ; Assistant Professor of Psy-
chology, 1892- ; Joint Editor, with
President Hall and Professor Titchener,
of the American Journal of Psychology ;
Member of the American Psychological
Association.
Author of : —
The Writings of Laura Bridgman. (Two
articles.) Overland Monthly, 1886-87.
The Relative Legibility of the Small
Letters. Am. Jour, of Psy., May,
1888, Vol. 1, pp. 402-435.
Personal Equation. Ibid., Nov., 1888;
Feb. and May, 1889, Vol. 2, pp. 3-38,
271-298, 403-430.
A Simple and Inexpensive Chronoscope.
Ibid., April, 1890, Vol. 3, pp. 174-181.
Psychology at Clark University. Ibid.,
April, 1890, Vol. 3, pp. 284-285.
A Laboratory Course in Physiological
Psychology. Ibid., April and Dec,
1891 ; April, 1892, Vol. 4, pp. 141-
155, 303-322, 474-490; April, 1893,
Vol. 5, pp. 390-415 ; Jan., 1895, Vol.
6, pp. 593-616; April, 1896, Vol. 7,
pp. 412-424.
A New Visual Illusion. Science, Feb. 17,
1893, Vol. 21, pp. 92-93.
On Reaction-Times when the Stimulus is
Applied to the Reacting Hand. (With
J. F. Reigart.) Am. Jour, of Psy.,
April, 1893, Vol. 5, pp. 351-365.
Published Papers.
539
A New Pendulum Chronograph. Ibid.^
April, 1893, Vol. 5, pp. 385-389.
Some Practical Suggestions on the Equip-
ment of a Psychological Laboratory.
Ibid., July, 1893, Vol. 5, pp. 429-438.
Notes on New Apparatus. Ihid., Jan.,
1895, Vol. 6, pp. 575-584.
The Philadelphia Meeting of the American
Psychological Association. Science,
Jan. 24, 1896, Vol. 3, pp. 119-124.
The Vernier Chronoscope. Am. Jour, of
Fsy., Jan., 1898, Vol. 9, pp. 191-197.
A Course in Experimental Psychology.
D. C. Heath & Co., Boston, Mass.,
1898. 449 pp.
CLARENCE ARTHUR SAUNDERS:
B.A., King's College, Windsor, N. S.,
1885; M.A., 1888; Graduate Student,
Johns Hopkins University, 1889-92 ; Assis-
tant, Smithsonian Institution, "Washing-
ton, 1891-92 ; Fellow in Physics, Clark
University, 1892-95; Ph.D., Clark
University, 1895 ; Professor of Mathe-
matics and Physics, Ursinus College,
1895-98.
Died Dec. 19, 1898.
Author of : —
The Velocity of Electric "Waves. Physical
Beview, Sept. -Oct., 1896, Vol. 4, pp.
81-105.
ALBERT SCHINZ:—
B.A., Neuchatel, 1888 ; M.A., ibid.,
1889 ; Licentiate in Theology, ibid., 1892 ;
Student, University of Berlin, 1892-93;
Student, Tubingen, 1893 ; Ph.D., Tiibin-
gen, 1894 ; College de France at Sor-
bonne, Paris, 1894 ; Second Librarian,
Library of Neuchatel, and Associate Pro-
fessor of Philosophy, University of Neu-
chatel, 1896-97 ; Honorary Fellow in
Psychology, Clark University, 1897-
98 ; Instructor in French, University of
Minnesota, 1898-99 ; Lecturer in French
Literature, Bryn Mawr College, 1899-.
Author of : —
La nature du p^ch^ : 6tude psychologique.
Delachaux et Niestl^, Neuchatel, 1892.
134 pp.
Morale et d^terminisme. Revue Philoso-
phique, Jan., 1895, Vol. 39, pp. 57-75.
La philosophic de M. Ernest Naville. Be-
vue de Theologie et de Philosophie,
July, 1895.
Mysticisme et Magie. Centralblatt des
Zofingervereins, Dec, 1895.
Le recent mouvement moral en Europe et
en Amerique. Bridel et Cie, Lau-
sanne, Suisse. (Imprim^d'aborddans
La Bevue de Theologie et de Philoso-
phie, Sept., 1896.)
Essai sur la notion du miracle, consid^rd
du point de vue de la th^orie de la
connaissance. Delachaux et Niestl^,
Neuchatel, 1897. 35 pp. (Reprint
from La Bevue de Theologie et de Phi-
losophie, March, 1897.)
La morality de I'enfant. Bevue Philoso-
phique, March, 1898, Vol. 45, pp. 259-
295.
Die Moralitat des Kindes. Translation
by Ch. Ufer. Langensalza, 1898. 42
pp. (Heft I. der " Beitrage zur Kin-
derf orschung. " ) '
Le positivisme est un m^thode et non un
syst^me. Bevue Philosophique, Jan.,
1899, Vol. 47, pp. 63-75.
Les biblioth^ques publiques en Amerique.
Bibliotheqiie Universelle, Lausanne,
Suisse, Aug.-Sept., 1898.
Les sports dans les Universit^s Am^ri-
caines. La Suisse Universitaire, Feb. ,
1899.
L'Universit^ de Clark h Worcester, Mass.
Bevue des Bevues, Paris, July, 1898.
L'^glise aux Etats Unis d'Am6rique. (In
press. )
Translation of Dr. E. C. Sanford's "A
Course in Experimental Psychology,"
Schleicher fr^res, Paris, 1899. (In
press. )
Chronique du f^minisme aux Etats-Unis.
Bevue de Morale Sociale, Paris, June,
1898.
La langue internationale Esperanto. La
Semaine Litteraire. Geneve, Suisse,
29 Juillet, 1899.
La secte des Scientistes Chretiens aux
Etats-Unis d'Am^rique. Bevue des
Bevues, Paris. (In press.)
540
Titles of
Un repr^sentant de TAgnosticisme aux
Etats-Unis, Robert G. IngersoU. (In
press.)
L' Education des nfegres aux Etats-Unis
d'Amfirique. L'institut de Tuskegee
en Alabama. La Semaine Litteraire.
Geneve. 21 Octobre, 1899.
Le culte d'Omar Khayyam. (In press.)
La Philosopliie et le Sens Commiin, Be-
vice Philosophique, 'Paris. (In press.)
ALVA ROY SCOTT : —
A.B., De Pauw University, 1886 ; A.M.,
ibid., 1889; Principal, Leavenworth
Schools, 1886-87 ; Student, McCormick
Theological Seminary, Chicago, 1888-91 ;
Pastor, First Presbyterian Church,
Hanover, 111., 1891-93; Graduate Stu-
dent, Harvard University, 189-3-94 ; Hon-
orary Scholar in Psychology, Clark
University, 1894-95 ; Pastor, First
Presbyterian Church, Worcester, Mass.,
1894-98.
COLIN ALEXANDER SCOTT: —
Student, College of City of New York,
1877-78 ; Graduate, Toronto Normal
School, 1879; Director of Instruction in
Drawing, Kingston Schools, 1883-84 ;
B.A., Queen's University, Kingston,
Ont., 1885 (Gold Medalist with Honors
in Chemistry, Biology, and Geology); In-
structor in Chemistry, Ladies' Medical
College, Kingston, 1885-86 ; Science Mas-
ter, IngersoU Collegiate Institute, 1886-87 ;
Science Master, Ottawa Collegiate Insti-
tute, 1887-94 ; Fellow in Psychology,
Clark University, 1894-96; Ph.D.,
Clark University, 1896 ; Head of De-
partment of Physiological Psychology and
Child Study, Chicago Normal School,
1896-.
Author of : —
Sex and Art. Am. Jonr. of Psy., Jan.,
1896, Vol. 7, pp. 153-226.
Old Age and Death. Ibid., June, 1896,
Vol. 8, pp. 67-122.
Childreri"s Foars as Material for Expres-
sion and a Basis of Education in Art.
Trans. III. Soc. for Child Study, April,
1898, Vol. 3, pp. 12-17.
E. W. SCRIPTURE : —
A.B., College of the City of New York,
1884; A.M., ibid., 1890; Universities of
Leipzig, Berlin, and Zurich, 1888-90 ;
Ph.D., University of Leipzig, 1891 ; Fel-
low in Psychology, Clark University,
1891-92 ; Instructor in Experimental
Psychology', Yale University, 1892-98 ;
Director of the Yale Psychological Labor-
atory, 1898- ; Assistant Editor of Ameri-
can Journal of Psychology, 1891-92 ; Edi-
tor of Studies from the Yale Psychological
Laboratory, 1893- ; Member : American
Psychological Association ; American So-
ciety of Naturalists ; Fellow, American
Association for the Advancement of
Science.
Author of : —
Vorstellung und Gefiihl. Philos. Studien,
1890, Vol. 6, pp. 536-542.
Ueber den associativen Verlauf der Vor-
stellungen. (Inaugural Dissertation.)
Leipzig, 1891, 101 pp., and Philos. Stu-
dien, 1891, Vol. 7, pp. 50-146.
Arithmetical Prodigies. Am. Jour, of
Psy., April, 1891, Vol. 4, pp. 1-59.
The Problem of Psychology. Mind, 1891,
Vol. 16, pp. 30-5-326.
Zur Definition einer Vorstellung. Philos.
Studien, 1891, Vol. 7, pp. 213-221.
Einige Beobachtungen iiber Schwebungen
und Differenztone. Ibid., 1892, Vol.
7, pp. 630-632.
The Need of Psychological Training. Sci-
ence, March 4, 1892, Vol. 19, pp. 127-
128.
An Instrument for Mapping Hot and Cold
Spots on the Skin. Ibid. , May 6, 1892,
Vol. 19, p. 2.58.
Education as a Science. Pedagogical Sem-
inary, June, 1892, Vol. 2, pp. 111-
114.
Psychological Notes. Am. Jour, of Psy.,
Aug., 1892, Vol. 4, pp. 577-584.
Tests on School Children. Educational
Eevieio, Jan., 1893, Vol. 5, pp. 52-
61.
1st eine cerebrale Entstehung von Schwe-
bungen moglich ? Philos. Studien,
1893, Vol. 8, pp. 638-640.
Published Papers.
541
Systematized Graduate Instruction in Psy-
chology. Science, July 28, 1893, Vol.
12, pp. 43-44.
A System of Color-teaching. Educational
Beview, Dec, 1893, Vol. 5, pp. 464-474.
Consciousness under the Influence of Can-
nabis indica. Science., Oct. 27, 1893,
Vol. 22, p. 233.
Psychological Measurements. Philosophi-
cal Beview, Nov. 1893, Vol. 2, pp.
677-689.
A New Reaction-key and the Time of
Voluntary Movement. (With J. M.
Moore.) Studies from Yale Psy.
Lab., 1892-93, Vol. 1, pp. 88-91.
Drawing a Straight Line : a Study in
Experimental Didactics. (With C. I.
Lyman.) Ibid., pp. 92-96.
Some New Psychological Apparatus. Ibid.,
pp. 97-100.
On the Measurement of Hallucinations.
Science, Dec. 29, 1893, Vol 22, p. 353.
Work at the Yale Laboratory. Psycho-
logical Beview, Jan., 1894, Vol. 1, pp.
66-69.
Ueber die Aenderungsempfindlichkeit.
Zeits. f. Psy. u. Phys. d. Sinnesorgane,
1894, Vol. 6, pp. ^12-^1^.
Observation on the Use of the Terminal
Verb in Infant Speech. Science, Feb.
2, 1894, Vol. 23, p. 62.
New Materials for Color- teaching. Edu-
cational Bevieio, April, 1894, Vol. 7,
pp. 382-383.
The Use of Antiphones. N. Y. Med. Jour.,
April 7, 1894, Vol. 59, p. 43.
On the Adjustment of Simple Psychologi-
cal Measurements. Psychological Be-
view, May, 1894, Vol. 1, pp. 281-282.
The Kinesimeter. (With E. B. Titchener.)
Am. Jour, of Psy., June, 1894, Vol.6,
pp. 424-426.
Accurate Work in Psychology. Ibid.,
pp. 427-430.
Some Psychological Illustrations of the
Theorems of Bernoulli and Poisson.
Ibid., pp. 431-432.
Methods of Laboratory Mind-study. Fo-
rum, Aug., 1894, Vol. 17, pp. 721-
728.
Aims and Status of Child Study. Educa-
tional Beview, Oct., 1894, Vol. 8, pp.
236-239.
On Mean Values for Direct Measurements.
Studies from Yale Psy. Lab., 1894,
Vol. 2, pp. 1-39.
Remarks on Dr. Gilbert's Article. Ibid.,
pp. 101-104.
Experiments on the Highest Audible Tone.
(With H. F. Smith.) Ibid., pp. 105-
113.
On the Education of Muscular Control and
Power. (With T. L. Smith and E. M.
Brown.) Ibid., pp. 114-119.
A Psychological Method of determining
the Blind -spot. Ibid., pp. 120-121.
Tests of Mental Ability as Exhibited in
Fencing. Ibid., pp. 122-124.
Reaction-time and Time-memory in Gym-
nastic Work. Bep. Ninth Meet. Am.
Ass'^n Physical Education, 1894, pp.
44-49.
On the Measurement of Imaginations,
Sci. Am., Feb. 9, 1895, Vol. 72, p.
85.
The Nature of Science and Its Relation to
Philosophy. Science, March 29, 1895,
N. S., Vol. 1, pp. 350-352.
Scientific Child Study. Trans. III. Soc.
for Child Study, May, 1895, Vol. 1,
pp. 32-37.
Simple but Accurate Tests for Child Study.
Ibid., pp. 57-60.
Practical Computation of the Median.
Psychological Beview, July, 1895, Vol.
2, pp. 376-379.
The Second Year at the Yale Laboratory.
Ibid., pp. 379-381.
A New Method of Computation. Sci.
Am. Supplement, July 6, 1895, Vol. 4,
p. 16270.
Thinking, Feeling, Doing. Flood & Vin-
cent, Meadville, Pa., 1895. 304 pp.
A New Method of Making Lantern Slides.
Scientific American, Aug. 24, 1895,
Vol. 73, p. 123.
Some Principles of Mental Education.
School Bevieio, Nov., 1895, Vol. 3, pp.
533-547.
A Method of Stereoscopic Projection.
Scientific American, Nov. 23, 1895,
Vol. 73, p. 327.
542
Titles of
Some New Apparatus. Studies from
Tale Psy. Lab., 1895, Vol. 3, p. 08-
109.
The Bad Eye Factory. Outlook, Feb. 29,
1896, Vol. 53, pp. 393-394.
Untersuchungen iiber die geistige Ent-
wickelung der Schulkinder. Zeits. f.
Psy. u. Phys. der Sinnesorgane, 1896,
Vol. 10, pp. 161-182.
Measuring Hallucinations. Science, May
22, 1896, N. S., Vol. 3, pp. 762-763.
Child Study : Methods and Results. Be-
port 65th Meeting Am. Institute of
Instruction, pp. 181-188.
The Third Year at the Yale Laboratory.
Psychological Beview, July, 1896, Vol.
3, pp. 416-421.
The Law of Rhythmic Movement. Sci-
ence, Oct. 9, 1896, N. S., Vol. 4, pp.
535-536.
My Pedagogic Creed. School Journal,
Dec. 5, 1896, Vol. 53, pp. 621-623.
Nouveaux Instruments. Annee psycholo-
gique, 1896, Vol. 3, pp. 658-664.
The Law of Size-Weight Suggestion. Sci-
ence, Feb. 5, 1897, N. S., Vol. 5, p. 227.
Sources of the New Psychology. Pop. Sci.
Mo., May, 1897, Vol. 51, pp. 98-106.
Pleasure without Other Sensations. N. Y.
Med. Jour., July 17, 1897, Vol. 66, p.
99.
Cerebral Light. Science, July 23, 1897,
N. S., Vol. 6, pp. 138-139.
The New Psychology. Walter Scott, Lon-
don, 1897. 500 pp.
Researches on Reaction-time. Stitdies
from Yale Psy. Lab., 1897, Vol. 4, pp.
12-26.
Researches on Voluntary Effort. Ibid.,
1897, Vol. 4, pp. 69-75.
New Apparatus and Methods. Ibid.,
1897, Vol. 4, pp. 76-88.
Elementary Course in Psychological Meas-
urements. Ibid., 1897, Vol. 4, pp. 89-
139.
On Binaural Space. Ibid., 1898, Vol. 5,
pp. 76-80.
Researches on the Memory for Arm
Movements. (With W. C. Cooke and
C. M. Warren.) Ibid., 1898, Vol. 5,
pp. 90-92.
Principles of Laboratory Economy. Ibid.,
1898, Vol. 5, pp. 93-103.
Reaction-time in Abnormal Conditions
of the Nervous System. Medical Rec-
ord, 1898, Vol. 53, p. 196.
Electrical Ansesthesia. Science, June 3,
1898, N. S., Vol. 7, p. 776.
The Anaesthetic Effects of a Sinusoidal
Current of High Frequency. Ibid.,
March 10, 1899, N. S., Vol. 9, p. 377.
Color Weakness and Color Blindness.
Ibid., June 2, 1899, N. S., Vol. 9, pp.
771-774.
Cerebral Light, Ibid., June 16, 1899,
N. S., Vol. 9, pp. 850-851.
Arousal of Instinct by Taste. Ibid., June
23, 1899, N. S., Vol. 9, p. 878.
Anaglyphs and Stereoscopic Projection.
Ibid., Aug. 11, 1899, N. S., Vol. 10,
pp. 185-187.
CHARLES H. SEARS: —
Graduate, State Normal School, Westfield,
Mass. (four years' course), 1883 ; Princi-
pal of Public Schools, Cheshire, Mass.,
1883-85 ; Teacher, Prospect Park Insti-
tute, Brooklyn, N. Y., 1885-88; Teacher
of Latin, State Normal School, Edinboro,
Pa., 1888-92; A.M., Allegheny College,
1893; Ph.D., Allegheny College, 1895;
Principal, Normal Department, Claflin
University, 1892-97 ; Honorary Fellow
in Pedagogy, Clark University, 1897-
99.
Author of: —
Home and School Punishments. Peda-
gogical Seminary, March, 1899, Vol,
6, pp. 159-187.
ALBERT E. SEGSWORTH : —
B.A., University of Toronto, 1890; Stu-
dent, University of Leipzig, 1890-91 ; Uni-
versity of Toronto, 1891-92 ; Student,
University of Leipzig, 1892-93 ; Honor-
ary Fellow in Psychology, Clark
University, 1893-94.
Author of : —
On the Difference Sensibility for the
Valuation of Space Distances with the
Help of Arm Movements. Am. Jour.
Published Papers.
54-
of Psy., June, 1894, Vol. 6, pp. 369-
407.
Ueber Innervationsempfindungen. (Pri-
vately printed.) 1894. 5 pp.
BENJAMIN F. SHARPE: —
A.B., Wesleyan University, 1887 ; A.M.,
ibid., 1890 ; Adjunct Professor of Physics
and Biology, Randolph-Macon College,
1887-91 ; Graduate Student and Scholar,
Johns Hopkins University, 1891-94 ; Fel-
lovy in Physics, Clark University,
1894-96 ; Professor of Mathematics,
State Normal School, New Paltz, N. Y.,
1896-97 ; Fellow in Physics, Clark
University, 1897-98.
Author of : —
A Double Instrument and a Double
Method for the Measurement of
Sound. Science, June 9, 1899, N. S.,
Vol. 9, pp. 808-811.
An Advance in Measuring and Photo-
gi-aphing Sounds. U. S. Weather Bu-
reau, No. 202, Washington, D. C,
1899. 18 pp., 7 pis.
JOHN C. SHAW: —
Graduate, State Normal School, Fairmont,
W. Va., 1889; Principal of Graded
Schools, Paw Paw, W. Va., 1889-90;
B.S., University of Nashville, 1892 ; M.S.,
ibid., 1894; L.I., Peabody Normal Col-
lege, Nashville, 1893 ; Principal of Public
School, Douglassville, Tex., 1893-94;
Teacher of Mathematics, Marshall Col-
lege, 1894-95 ; Scholar in Pedagogy,
Clark University, 1895-96 ; Fellow
in Psychology, 1896-97 ; Teacher in
State Normal School, West Liberty, W.
Va., 1897-.
Author of : —
Chairs of Pedagogy in the United States.
W. Va. School Journal, April, May,
and June, 1895.
A Test of Memory in School Children.
Pedagogical Seminary, Oct., 1896, Vol.
4, pp. 61-78.
What Children like to Read. W. Va.
School Journal, Charleston, W. Va.,
Oct., 1897, Vol. 17, pp. 5-6.
HENRY DAVIDSON SHELDON: —
A.B., Stanford University, 1896; A.M.,
ibid., 1897 ; Instructor in Department of
Education, ibid., 1896-97; Fellow and
Assistant in Pedagogy, Clark Univer-
sity, 1897-99.
Author of : —
The Institutional Activities of American
Children. Am. Jour, of Psy., July,
1898, Vol. 9, pp. 425-448.
FREDERIC D. SHERMAN: —
A.B., University of Michigan, 1887;
Principal of Berrien Springs, Mich.,
School, 1887-88; Principal of Charlotte,
Mich., High School, 1888-89; Principal
of Bay City, Mich., High School, 1889-
94 ; Universities of Bonn and Leipzig,
1894-97; Ph.D., University of Leipzig,
1897 ; Professor of Psychology and Peda-
gogy, State Normal School, Oshkosh,
Wis., 1897-98; Honorary FeUow in
Psychology, Clark University, Oct.-
Nov., 1898 ; Lecturer in History of Edu-
cation, Teachers College, Columbia Uni-
versity, Dec, 1898-June, 1899 ; Assistant
in Latin, Erasmus Hall High School,
Brooklyn, N. Y., 1899-.
Author of : —
Ueber das Purkinje'sche Phanomen im
Centrum der Netzhaut. Philosophische
Studien, 1897, Vol. 13, pp. 434-479.
TOSHIHIDE SHINODA: —
Graduate, Higher Normal School, Tokio,
Japan ; Graduate Student in United States
and Europe, 1888-91; Honorary Scholar
in Pedagogy, Clark University, 1889-
90 ; Professor in Higher Normal School,
Tokio, Japan, 1891-.
LOUIS SIFF: —
S.B., Cornell University (Special Mention
in Mathematics), 1897 ; Graduate Student,
Johns Hopkins University, Oct., 1897-
Eeb., 1898; Scholar in Mathematics,
Clark University, 1898-99 ; Teaching
Fellow in Mathematics, University of Ne-
braska, 1899-.
544
Titles of
ERNEST B. SKINNER: —
A.B., Ohio University, 1888; Professor
of Mathematics, Amity College, College
Springs, la., 1880-91 ; Scholar in Mathe-
matics, Clark University, 1891-92 ;
Instructor in Mathematics, University of
Wisconsin, 18U2-95 ; Assistant Professor,
ihid., 1895-; Member American Mathe-
matical Society.
STEPHEN E. SLOCUM : —
B.E., Union University (Honors in Mathe-
matics and Physics), 1897 ; Scholar
in Mathematics, Clark University,
1897-98 ; Fellow, 1898-99.
Author of : —
Note on the Chief Theorem of Lie's
Theory of Continuous Groups. Proc.
Am. Acad. (In press.)
JAMES R. SLONAKER : —
Graduate, Indiana State Normal School,
1889 ; Supervising Principal of Schools,
Elroy, Wis., 1889-91 ; University of Wis-
consin, 1891-93; B.S., ibid., 1893; Pel-
low in Biology, Clark University,
1893-96 ; Ph.D., Clark University,
1896 ; Instructor in Zoology, Indiana
University, 1896- ; Member Indiana
Academy of Science.
Author of: —
A Comparative Study of the Point of
Acute Vision in the Vertebrates.
American Naturalist, Jan., 1896, Vol.
30, pp. 24-32.
A Comparative Study of the Area of
Acute Vision in Vertebrates. Jour.
of Morph., May, 1897, Vol. 13, pp.
445-502.
The Fovea. Proc. Ind. Acad, of Science,
1896, pp. 304-310.
A Method of Preserving the Eye for
Sectioning, or for Demonstrating the
Area of Acute Vision. Jour, of
Applied Microscopy, Feb., 1896, Vol.
1, p. 18.
The Eye of the Mammoth Cave Rat.
Proc. Ind. Acad, of Science, 1898.
MAURICE H. SMALL: —
A.B., Colby University, 1887 ; Principal,
High School, Norway, Me., 1887-92 ;
ibid., Westbrook, Me., 1892-95 ; Scholar
in Psychology, Clark University,
1895-96 ; FeUow, 1896-98 ; Prin-
cipal High School, Passaic, N. J., 1898-.
Author of : —
The Suggestibility of Children. Peda-
gogical Seminary, Dec, 1896, Vol. 4,
pp. 176-220.
Methods of manifesting the Instinct for
Certainty. Ibid., Jan., 1898, Vol. 5,
pp. 313-380.
An Experiment borrowed from the School-
room. Northwestern 3Ionthly, Nov.,
1898, Vol. 9, pp. 134-135.
WILLARD STANTON SMALL: —
A.B., Tufts College, 1894 ; A.M., ibid.,
1897; Tufts Divinity School, 1894-96;
Professor of English Language and Lit-
erature, Lombard University, 1896-97 ;
Scholar in Psychology, Clark Uni-
versity, 1897-98; Fellow, 1898-99.
Author of : —
Friedrich Nietzsche (Review). Pedagogi-
cal Seminary, April, 1898, Vol. 5,
pp. 606-610.
Note on the Psychic Development of the
Young White Rat. Am. Jour, of Psy.,
Oct., 1899, Vol. 11, pp. 80-100.
•WARREN R. SMITH: —
A.B., Bowdoin College, 1890 ; Instructor
Leicester Academy, Leicester, Mass.,
1890-91 ; Scholar in Chemistry, Clark
University, 1891-92 ; Fellow in Chem-
istry, University of Chicago, 1892-94 ;
Ph.D., ibid., 1894 ; Assistant in Chemistry,
Bowdoin College, 1894-95 ; Instructor in
Science, New Bedford High School, 1895-
96 ; Instructor in charge Department of
Chemistry, Lewis Institute, Chicago, 111.,
1896-.
Author of : —
On the Addition Products of the Aro-
matic Isocyanides. Am. Chem. Jour.,
May, 1894, Vol. 16, pp. 372-393.
Published Pcqjers.
545
HUGH A. SNEPP: —
A.B., Heidelberg College, 1893 ; Princi-
pal, High School, Germantown, O., 1893-
94 ; Tutor in Mathematics, Heidelberg
College, 1894-95; Scholar in Mathe-
matics, Clark University, 1895-96 ;
Instructor in Mathematics and Science,
High School, Tiffin, 0., 1896-98; Student
in Mathematics, University of Chicago,
Summer Quarter, 1897.
FRANK E. SPAULDING: —
A.B., Amherst College, 1889 ; Instructor,
Military Academy, Louisville^ Ky., 1889-
90 ; Instructor and Associate Principal,
ibid.^ 1890-91 ; Student in Universities of
Leipzig, Paris, and Berlin, 1891-94 ;
Ph.D., University of Leipzig, 1894 ;
Honorary Fellow in Psychology,
Clark University, Oct., 1894-May,
1895 ; Superintendent of Schools, Ware,
Mass., May, 1895- June, 1897; Superin-
tendent of Schools, Passaic, N. J., Sep-
tember, 1897- ; President, New Jersey
Association for the Study of Children and
Youth, 1899.
Author of: —
Richard Cumberland als Begriinder der
Englischen Ethik. Leipzig, 1894. xii.
+ 101 pp.
The Province of the Elementary School.
Jour, of Pedagogy, Sept. , 1896, Vol. 9,
pp. 129-137.
Mental Images. Educational Founda-
tions, Sept., 1897, Vol. 9, pp. 15-21.
The Dynamics of Mental Images. Ihid.,
Oct., 1897, Vol. 9, pp. 65-70.
Some Psychic Processes involved in Read-
ing. Ibid., Nov., 1897, Vol. 9, pp. ISO-
IS?.
The Psychology of Defective Reading.
Ibid., Dec, 1897, pp. 194-201.
Mental Economy in Reading. Ibid. , Jan.,
1898, Vol. 9, pp. 257-262.
Psychic Aspects of Learning to Read.
Ibid., Feb., 1898, Vol. 9, pp. S47-
353.
Preventing and Correcting Defective
Reading. Ibid., March, 1898, Vol. 9,
pp. 389-395.
2n
What can One Read ? Ibid., April, 1898,
Vol. 9, pp. 514-520.
Psychology in Geography. Ibid., May
and June, 1898, Vol. 9, pp. 572-577,
619-625.
The Elementary Character of Secondary
Education. Jour, of Pedagogy, Jan.,
1899, Vol. 12, pp. 11-24.
Immediate Educational Work. Annual
Report, Supt. of Schools, Ware, Mass. ,
Feb. 1, 1896, pp. 17-22.
Educational Policy and Aims. Ibid., Feb.
1, 1897, pp. 14-32.
The Course of Study ; Grading and Pro-
motion, etc. Annual Report, Supt.
of Schools, Passaic, N. J., 1897-98, pp.
9-64.
EDWIN D. STARBUCK: —
A.B., Indiana University, 1890 ; Teacher
of Mathematics and Latin, Spiceland,
Ind. Academy, 1890-91 ; Teacher of
Mathematics, Vincennes College, 1891-93 ;
Student in Psychology, Harvard Univer-
sity, 1893-95; A.B., ibid.; 1894; A.M.,
ibid., 1895; Fellow in Psychology,
Clark University, 1895-97 ; Ph.D.,
Clark University, 1897 ; Assistant Pro-
fessor of Education, Stanford University,
1897-.
Author of : —
A Study of Conversion. Am. Jour, of
Psy., Jan., 1897, Vol. 8, pp. 268-308.
Some Aspects of Religious Growth. Ibid. ,
Oct., 1897, Vol. 9, pp. 70-124.
Child Study and its Possibility as a Sci-
ence. Northwestern Monthly, March-
April, 1899, Vol. 9, pp. 358-362.
Psychology of Religion. With an intro-
duction by Professor William James.
Contemporary Science Series. (In
press.)
ORLANDO S. STETSON: —
Worcester Polytechnic Institute, 1896-98 ;
Scholar in Mathematics, Clark Uni-
versity, 1898-99.
COLIN C. STEWART: —
B.A., University of Toronto, 1894;
Scholar in Physiology, Clark Uni-
646
Titles of
versity, 1894-95 ; FeUow, 1895-97 ;
Ph. D., Clark TJni versity, 1897 ; As-
sistant iu riiysiology, Harvard Medical
School, 1897-98; Tutor m Physiology,
Columbia University, 1808- ; Member
American Physiological Society.
Author of: —
The Influence of Acute Alcohol Poisoning
on Nerve Cells. Jour, of Exp. Medi-
cine, Nov., 1896, Vol. 1, pp. 623-629.
Variations in Daily Activity produced by
Alcohol and by Changes in Barometric
Pressure and Diet, with a Description
of Recording Methods. Am. Jour, of
Physiology, Jan., 1898, Vol. 1, pp. 40-
56.
On the Course of Impulses to and from
the Cat's Bladder. Ibid., Jan., 1899,
Vol. 2, pp. 182-202.
A Simple Etherizing Bottle. Ibid. (Proc.
Am. Physiol. Soc, Dec, 1898), Vol. 2,
p. X.
The Relaxation of the Cat's Bladder.
Ibid., Aug., 1899, Vol. 3, pp. 1-8.
JULIUS STIEGLITZ: —
University of Berlin, 1886-89 ; University
of Gottingen, 1888; Ph.D., University of
Berlin, 1889; Scholar in Chemistry,
Clark University, Jan.-June, 1890 ;
Chemist, Parke, Davis & Co., Detroit,
Mich., 1890-92; Docent in Chemistry,
University of Chicago, 1892-93 ; Assistant
in Chemistry, ibid., 189;3-94 ; Instructor
in Chemistry, ibid., 1894-97; Assistant
Professor in Chemistry, ibid., 1897- ; Fel-
low of the American Association Advance-
ment of Science ; Member, Deutsche
Chemische Gesellschaft.
Author of : —
Ueber das Verhalten der Amidoxime
gegen Diazobenzolverbindungen. Ber.
d. deuts. chem. Gesellschaft, 1889, Vol.
22, pp. 3148-3160.
On Benzoquinone Carboxylic Acids. Am.
Chem. Jour., 1891, Vol. 13, pp. 38^2.
Alkaloidwertbestimmung von Extrakten.
Pharmaceutische Bundschau, 1892 and
1893, 3 papers.
Ferric Phosphate, U, S. P., and Ferric
Pyrophosphate, U. S. P. Journal of
Pharmacy, 1891.
Notes on Pyrophosphoric and Phosphoric
Acid. Ibid., 1891.
Derivatives of Nitrogen Halogen Com-
pounds. (With F. Lengfeld.) A7n.
Chem. Jour., 1893, Vol. 15, pp. 215-
222, 504-518 ; Vol. 16, pp. 370-372.
The Action of Phosphorus Pentachloride
on Urethanes. (With F. Lengfeld.)
Ibid., 1894, Vol. 16, pp. 70-78.
Ueber Alkylisoharnstoffe. (WithF. Leng-
feld.) Ber. d. deuts. chem. Gesell-
schaft, 1894, Vol. 27, pp. 926-927.
Ueber die Einwirkung von Natrium-
athylat auf Carbodiphenylimid. Ibid.,
1895, Vol. 28, pp. 573-574.
Ueber Thiamine. (With F. Lengfeld.)
Ibid., 1895, Vol. 28, pp. 575-576, 2742-
2744.
On Imidoethers of Carbonic Acid. (With
F. Lengfeld.) Am. Chem. Jour., 1895,
Vol. 17, pp. 98-113.
On the "Beckmann Rearrangement."
Ibid., 1896, Vol. 18, pp. 751-761.
On the Constitution of the Salts of Imido-
ethers and other Carbimide Deriva-
tives. Ibid., 1899, Vol. 21, pp. 101-
111.
F. E. STINSON: —
Iowa Agricultural College, 1884-86 ; Prin-
cipal, Poplar Grove Institute, Ark., 1889-
90; Instructor in Physics and Mathematics,
Paris Academy, Ark., 1890-92; Scholar
in Mathematics, Clark University,
1892-93 ; Fellow, 1893-95.
WILLIAM E. STORY: —
A.B., Harvard University, 1871 ; Parker
Fellow, ibid., 1874-75; Universities of
Berlin and Leipzig, 1871-75; Ph.D.,
University of Leipzig, 1875; Tutor of
Mathematics, Harvard University, 1875-
76 ; Associate, Assistant Professor, and
Associate Professor of Mathematics,
Johns Hopkins University, 1876-89 ; As-
sociate Editor iu Charge, Amei'ican Jour-
nal of Mathematics, 1878-82 ; Professor
of Mathematics, Clark University,
Published Papers.
547
1889- ; Editor, Mathematical Eeview,
1896-.
Author of: —
On the Algebraic Relations existing be-
tween the Polars of a Binary Quantic.
Dissertation approved for the degree of
Ph.D., Leipzig, 1875. 58 pp.
On the Elastic Potential of Crystals. Am.
Jour, of Math., 1878, Vol. 1, pp. 177-
183.
Note on Mr. Kempe's Paper on the Geo-
graphical Problem of the Jour Colors.
Ibid., 1879, Vol. 2, pp. 201-204.
Note on the "15" Puzzle. Ibid., 1879,
Vol. 2, pp. 399-404.
On the Theory of Rational Derivation on a
Cubic Curve (followed by a Note on
Totients). Ibid., 1880, Vol. 3, pp.
356-387.
On the Non-Euclidean Trigonometry.
Ibid., 1881, Vol. 4, pp. 332-335.
On the Non-Euclidean Geometry. Ibid.,
1882, Vol. 5, pp. 180-211.
On Non-Euclidean Properties of Conies.
Ibid., 1882, Vol. 5, pp. 358-381.
On the Absolute Classification of Quadratic
Loci, and on their Intersections with
each other and with Linear Loci.
Ibid., 1885, Vol. 7, pp. 222-245.
The Addition-Theorem for Elliptic Func-
tions. Ibid., 1886, Vol. 8, pp. 364-
375.
A New Method in Analytic Geometry.
Ibid., 1887, Vol. 9, pp. 38-44.
On the Covariants of a System of Quan-
tics. Math. Annalen, 1893, Vol. 41,
pp. 469-490.
On an Operator that produces all the Co-
variants and Invariants of any System
of Quantics. Proc. London Math.
Soc, 1892, Vol. 23, pp. 265-272.
Hyperspace and Non-Euclidean Geometry.
I. Mathematical Beview, April, 1897,
Vol. 1, pp. 169-184.
J. RICHARD STREET: —
A.B., Victoria University, 1884; A.M.,
ibid., 1888 (with First Honors in English,
French, German, and Italian) ; Modern
Language Master, Smithville High School,
1885-86; Walkerton High School, 1886-
87 ; Principal Caledonia High School,
Ontario, 1887-95 ; Associate Member of
the Board of Government Examiners,
1891-95 ; Member and Secretary of the
County Board of Examiners for Profes-
sional Teachers' Certificates, 1889-95 ;
Sometime Examiner in English, French,
and Gei'man for Albert, Alma, and Brant-
ford Colleges ; Instructor in the Mechanics
Institute, Caledonia, 1893-95 ; Scholar
in Pedagogy, Clark University, 1895-
96 ; Fellow in Psychology, 1896-98;
Ph.D., Clark University, 1898; Pro-
fessor of Pedagogy, Bible Normal College,
Springfield, Mass., 1898- ; also Prof essor of
Theory and Practice of Teaching, Mount
Holyoke College, 1899-.
Author of : —
A Study in Language Teaching. Peda-
gogical Seminary, April, 1897, Vol. 4,
pp. 269-293.
A Study in Moral Education. Ibid., July,
1897, Vol. 5, pp. 5-40.
A Genetic Study of Immortality. Ibid.,
Sept., 1899, Vol. 6, pp. 267-313.
Linguistic Interpretation. (In press.)
CHARLES A. STRONG: —
A.B., University of Rochester, 1884 ; A.B.,
Harvard University, 1885 ; Rochester
Theological Seminary, 1886-86; Fellow,
Harvard University, 1886-87 ; University
of Berlin, 1886-87 ; Instructor in Philoso-
phy, Cornell University, 1887-89 ; Uni-
versities of Paris, Berlin, and Freiburg,
1889-90 ; Docent in Philosophy, Clark
University, 1890-91 ; Associate Pro-
fessor of Psychology, University of Chi-
cago, 1892-95 ; Lecturer in Psychology,
Columbia University, 1895-.
Author of : —
A Sketch of the History of Psychology
among the Greeks. Am. Jour, of Psy. ,
Dec, 1891, Vol. 4, pp. 177-197.
Dr. Mtinsterberg's Doctrine of Mind and
Body and its Consequences. Philo-
sophical Beview, March, 1892, Vol. 1,
pp. 179-195.
548
Titles of
Mr. James Ward on Modern Psychology.
Psychological Beviexo, Jan., 1894, Vol.
I, pp. 73-81.
The Psychology of Pain. Ibid., July,
1895, Vol. 2, pp. 329-347.
Physical Pain and Pain Nerves. Ibid.,
Jan., 1896, Vol. 3, pp. 64-68.
Consciousness and Time. Ibid., March,
1896, Vol. 3, pp. 149-157.
CHARLES K. SWARTZ: —
A.B., Johns Hopkins University, 1888 ;
University of Heidelberg, 1888-89; Fel-
low in Chemistry, Clark University,
1889-90 ; Gettysburg Theological Semi-
nary, 1890-91 ; Oberlin Theological Semi-
nary, 1891-92; B.D., ibid., 1892 ; Pastor,
Congregational Church, Bellevue, O.,
1892-.
HENRY TABER: —
Ph.B., Yale University (Shefl&eld Scien-
tific School), 1882 ; Johns Hopkins Univer-
sity, 1882-85 and 1886-88 ; Ph.D., Johns
Hopkins University, 1888 ; Assistant in
Mathematics, ibid., 1888-89; Decent in
Mathematics, Clark University. 1889-
92; Assistant Professor of Mathe-
matics, 1892- ; Resident Fellow Ameri-
can Academy of Arts and Sciences ;
Member : London Mathematical Society ;
American Mathematical Society.
Author of:
On the Theory of Matrices. Am. Jour.
of Math., July, 1890, Vol. 12, pp. 337-
396.
On the Application to Matrices of any
order of the Quaternion Symbols S and
V. Proc. London Math. Soc, Dec.
II, 1890, Vol. 22, pp. 67-79.
On Certain Identities in the Theory of
Matrices. Am. Jour, of Math., Jan.,
1891, Vol. 13, pp. 159-172.
On Certain Properties of Symmetric,
Skew Symmetric, and Orthogonal
Matrices. Proc. London Math. Soc,
June 11, 1891, Vol. 22, pp. 449-469.
On the Matrical Equation <^Q = ^:10SANC[1%
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