REESE LIBRARY 
 
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 UNIVERSITY OF CALIFORNIA 
 
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THE 
 
 HYGIENE OF THE EYE 
 
 IN SCHOOLS. 
 
 BY 
 
 HERMANN CORN, M.D. &PH.D., 
 
 PROFESSOR OF OPHTHALMIC SCIENCE IN THE UNIVERSITY OF BRESLAU. 
 
 AN ENGLISH TRANSLATION, EDITED BY 
 
 W. P. TURN BULL, 
 
 Formerly Fellow of Trinity College, Cambridge, and afterwards Fellow of 
 St. Catharine's College^ Cambridge. 
 
 Progressive short sight is in every case ominous of evil for the future." DONDERS 
 
 LONDON : 
 SIMPKIN, MARSHALL AND Co., STATIONERS' HALL COURT. 
 
 BIRMINGHAM AND LEICESTER : 
 THE MIDLAND EDUCATIONAL COMPANY, LIMITED. 
 
' 
 
 c> 
 
TABLE OF CONTENTS. 
 
 PAGE 
 
 INTRODUCTION ...... _. i 
 
 CHAPTER I. PREFATORY ANATOMICAL REMARKS . . .5 
 
 II. PHYSICAL AND CHEMICAL PROCESSES OF SIGHT . 15 
 
 III. ACCOMMODATION . . . . .22 
 
 IV. ACUITY OF VISION . . . . .26 
 
 V. REFRACTION . . . . . 34 
 
 VI. HYPEROPIA .- . . . . 37 
 
 VII. MYOPIA (SHORT SIGHT) . . . . .41 
 
 VIII. REFRACTION OF THE EYES OF SCHOOL CHILDREN . 54 
 
 IX. MYOPIA AMONG SCHOOL CHILDREN OF DIFFERENT 
 
 NATIONS . . .' . . .84 
 
 X. INFLUENCE OF HEREDITY ON THE SHORT SIGHT OF 
 
 SCHOOL CHILDREN . . . . .88 
 
 XI. SCHOOL-DESKS . . . . . .94 
 
 ,, XII. STRAIGHT - HOLDERS ..... 123 
 
 - XIII. DAY LIGHTING OF SCHOOLROOMS . . . 131 
 
 SUPPLEMENT TO CHAPTER XIII. . . . 146 
 
 " XIV. ARTIFICIAL LIGHTING OF SCHOOLROOMS . .160 
 
 SUPPLEMENT TO CHAPTER XIV. . . , 163 
 
 XV. HANDWRITING . . . . . .172 
 
 XVI. SLATES AND BLACKBOARDS .... 184 
 
 - 
 
 XVII. WRITING, DRAWING AND HAND-WORK LESSONS . 191 
 
 XVIII. PRINT AND PAPER . . . . .195 
 
 XIX. SPECTACLES . , . . .210 
 
 XX. OVERWORKING THE EYES . . . 215 
 
 XXI. DISEASES OF THE CONJUNCTIVA . . .220 
 
 XXII. THE SCHOOL-DOCTOR . . . . .223 
 
 CONCLUSION ........ 235 
 
 CATALOGUE OF LITERATURE .... END 
 
IV. PREFACE. 
 
 PREFACE. 
 
 IN the following work will be found, rewritten and extended, an 
 Essay on " School-children's Eyes," which I published in September, 
 1882, in Eulenbergs Technical Encyclopedia of Universal Medicine. 
 
 Soon after the appearance of that essay in a great collective work 
 intended only for medical men, a desire was expressed by several 
 publishers, and to myself personally by the Government in Breslau, 
 that I should publish the article separately for the benefit of non- 
 medical circles. 
 
 There were, however, a number of reasons which, in my opinion, 
 seemed to make the publication of a mere reprint undesirable. In 
 the first place, the form necessary for the medical Encyclopaedia 
 was, I thought, scarcely adapted for a larger circle of readers and, that 
 being the case, it was necessary to have regard to theoretical treatises 
 which had appeared since the publication of the article and also to 
 the very important reports of the Commissions on School Hygiene appointed 
 quite recently. Moreover, it seemed desirable to add a chapter on 
 desks. Lastly, I thought it requisite to preface the work, for the 
 benefit of those readers who do not belong to the medical profession, 
 with a short anatomical, physiological and pathological introduction 
 (Chapters I. VII.), in which I have included nothing but what 
 is, in my opinion, absolutely necessary for the comprehension of 
 the chapters on Hygiene proper. It is not, however, impossible that 
 even among my medical colleagues one or two may be found to whom 
 this short introduction will not be wholly unwelcome, as serving to 
 refresh their imemory of the subjects concerned. 
 
 The manuscript was sent to Vienna on the 3rd of January last, but 
 circumstances delayed until now its completion in a printed form 
 distinguished by a type unusually large. New publications which have 
 appeared during the printing have been taken account of, as far as 
 possible, by means of inserted paragraphs and in notes, as well as in 
 the Catalogue of Literature. 
 
 I now offer this book to the public, in the hope that it will meet 
 with a kindly reception and indulgent criticism. 
 
 However much I have endeavoured to collect together in complete- 
 ness the whole material, and at the same time to do full justice to 
 every proposal for the improvement of prevailing arrangements in our 
 
PREFACE. V. 
 
 schools, yet, considering the keen emulation aroused in this very 
 quarter among all civilized nations of our time, it is only too 
 possible that some details have escaped me and that some have been 
 differently judged of by other observers. I shall be most grateful for 
 any communication on these points, as also for any hint suggested 
 by practical experience. 
 
 May the present work contribute towards putting an end at last to 
 the hygienic defects existing in many of our schools and so towards 
 lessening for our scholars, as far as lies in our power, the grave 
 dangers of the short sight which is gaining ground in a manner really 
 terrible. 
 
 THE AUTHOR. 
 
 Breslau, 24th April, 1883. 
 
vi. ENGLISH EDITOR'S PREFACE. 
 
 ENGLISH EDITOR'S PREFACE. 
 
 THE great importance of the subject and the great reputation of 
 the author, Professor Hermann Cohn of Breslau, are, it is 
 hoped, sufficient reasons for publishing this book in an English form. 
 
 For the English edition Dr. Cohn has kindly furnished two considerable 
 supplements, on the day lighting and on the artificial lighting of 
 classrooms. Translations of these supplements are appended to the 
 chapters on their respective subjects. 
 
 Dr. Cohn has recently constructed, on Snellen's principles, a diagram 
 for testing acuity of vision. It consists of 36 E's arranged in a 
 square. The E's are in different attitudes, that is, they are open at 
 the top, bottom, right or left. The person whose sight is to be 
 tested is required to read these 36 E's, that is, to say in which 
 direction each E is open. Learning by heart is hindered not only 
 by varying the order of reading but by the simple contrivance of 
 attaching a separate suspender to each of the four sides of the card 
 on which the diagram is printed. 
 
 It will be seen that Dr. Cohn attaches great importance to straight- 
 holders. In a recent publication (on the necessity for school doctors) 
 he mentions a new rest, by Landsberg of Hanover, as possibly more 
 comfortable than Kallmann's. 
 
 For much kind assistance the English Editor's best thanks are due 
 to Mr. A. E. Chesshire, Ophthalmic Surgeon, Wolverhampton. 
 
 W. P. T. 
 August, 1886. 
 
EYESIGHT IN SCHOOLS, 
 
 INTRODUCTION. 
 
 " IT is hardly possible for those who are in the 
 possession of strong, healthy sight to estimate at its full 
 worth the part which the eye plays in the development 
 of the mental powers, in forming our views of the world 
 around us and in the relationships which exist between 
 man and man. Orators have praised the eye, poets 
 have sung of it ; but its full worth lies hidden away in 
 the silent yearning of those who have once possessed, 
 and now have lost, its light." 
 
 Can a treatise like the present find a more beautiful 
 and fitting justification for its appearance than the pre- 
 ceding words, spoken by one called away too soon from 
 among us, the late Albrecht von Grafe ? 
 
 The silent yearning of those who have once possessed, 
 and now have lost, their eyesight ! It is not the man 
 blind from his birth that suffers the hardest fate ; for his 
 need private charity and public institutions have sufficiently 
 provided. But who may find support and suitable occu- 
 pation for the man whose power of vision is gradually 
 tailing him ? The weight of this misfortune falls heaviest 
 on the student or man of letters. What is left for a 
 teacher, a lawyer, a doctor, a professor, a Statesman or any 
 other professional man, when he is attacked in the prime 
 oi life with blindness of one eye, while the other is 
 surely drifting through progressive short-sightedness towards 
 
2 INTRODUCTION. 
 
 the same fate ? And such cases come only too often 
 under the notice of every oculist. When a father brings 
 me his son, suffering from short sight, with the question 
 " What profession do you advise for him ?" I can give 
 him the choice of being a gardener, a farmer, a brewer, 
 a baker, or a rope maker, and I can then hope that 
 his calling will at least not aggravate the existing malady. 
 But what is an oculist to say to a man, who after a 
 long and expensive course of study has gained an ap- 
 pointment or a position which will compel him to read 
 and write all day long, and whose one eye is already 
 ruined by haemorrhage or detachment of the retina, while 
 the other is suffering all the effects of advanced and yearly 
 increasing short sight? Even if a retiring pension is pos- 
 sible, it is almost always accompanied by financial loss ; 
 and it would be well for every student, before his matricu- 
 lation to consult an oculist as to whether his eyesight 
 will be equal to the demand made upon it by his 
 future professional duties, 
 
 It is, however, the school itself, as will be shown in 
 the following pages, that must incur the reproach of 
 contributing together with other factors, to the ruin of 
 many an eyesight. How can this be ? Partly no doubt 
 from the fact, that neither the teachers of our elementary 
 schools, nor the professors of our universities are in- 
 structed or examined in the laws and treatment of the 
 eyesight ; and governesses whose certificates testify to 
 their high abilities in other respects have seldom any idea 
 of the factors which are of importance in determining 
 the position in which a child should sit. 
 
 Now as teachers are entrusted with the care of not 
 only the mental but also the physical health of their 
 scholars, and that for very many hours in every year, 
 parents have surely a right to demand that their children, 
 who are compelled by law to attend school, should not 
 suffer injury to their health by that attendance. 
 
INTRODUCTION. 3 
 
 At the present moment, indeed, there are many Prin- 
 cipals of schools who re-echo the complaints made by 
 medical men for the last ten years, and who feel an 
 interest in school - hygiene, but it is not so long 
 ago that Head Masters of high attainments as philo- 
 logists were too much absorbed in their Horace and 
 their Sophocles to be conscious of the existence of a 
 whole literature on the very important question of 
 school desks or, if conscious, to do more than regard 
 the matter with lofty indifference. It was left, therefore, 
 for doctors to urge on this movement, men who were 
 guided both by scientific instinct and by just and practical 
 aims ; and they were never weary of popularising in 
 lectures and pamphlets those things which they knew to 
 be true. 
 
 The most distinguished oculists of earlier times had 
 already perceived the necessity of some instruction re- 
 specting the treatment of the eye ; and so far back as 
 the year 1800 G. J. Beer, a Viennese professor, published 
 an excellent work entitled " Treatment of healthy and of 
 weak Eyes," which contained many important hints for 
 teachers. In 1865 there appeared in Prague the third 
 edition of the " Treatment of the Eyes in a healthy and 
 in a diseased condition," a first-class book by Professor 
 von Arlt. Lectures upon the Eye were given by Helm- 
 holtz and by Albrecht von Grafe. A great number of 
 smaller writings have been published on the same subject 
 in every language. In 1877 a capital Manual of Hygiene 
 for the School by Baginsky was brought out in Berlin. 
 And yet it is in our schools that we meet every day 
 with the grossest violations of the first laws of hygiene 
 concerning the eye. 
 
 These are the reasons which seem to promise some 
 degree of usefulness to a new work, treating briefly the 
 Hygiene of the Eye in our Schools. All doubtful and con- 
 troverted points which find their place in the special text 
 
4 INTRODUCTION. 
 
 books of anatomy, physiology and medicine have been as 
 far as possible avoided, and only those are introduced 
 which are unquestioned or require further comment and 
 explanation. 
 
 For without some knowledge of the most important 
 anatomical and physiological facts of the case it is 
 impossible to understand the Hygiene of the eye ; and 
 I therefore preface this work with a few anatomical and 
 physiological remarks. These, however, have reference 
 only to those parts and processes which are of obvious 
 importance to the subject. 
 
CHAPTER I. PREFATORY ANATOMICAL REMARKS. 
 
 CHAPTER FIRST. 
 
 PREFATORY ANATOMICAL REMARKS. 
 
 The Eye,* as is well known, is about an inch in 
 diameter and spherical in shape. It is composed of 
 clear fluid, and of thin membranous tissues in part boxed 
 into each other like the scales of a bulb, which explains 
 why the eyeball is also called b^llbus. 
 
 The outer case, of which only the front part is generally 
 visible, is called the sclera (Fig. !.,.). It is of a blueish 
 white colour, like porcelain, but in old age turns a 
 yellowish white. The back part of the sclera lies in the 
 fatty tissue of the socket (orbita), which also encloses the 
 optic nerve. The sclera (from scleros, " hard ") is the 
 strongest and thickest of the three layers of skin (sclera, 
 choroid, and retina), for it is the case which holds the 
 eye itself. It is also called in German lederhaut (''leather 
 skin"). 
 
 This case of the eye is not closed in front, but is 
 covered by the transparent cornea, which fits into it 
 like the glass into the case of a watch (a). The cornea 
 is generally as transparent as the purest water and as 
 smooth as the finest mirror. Like every convex mirror, 
 it presents upright and diminished images of all the 
 objects it reflects ; and that is why we see a miniature 
 reflection of our own face in other people's eyes. The 
 cornea measures from 10 to 12 millimeters across the 
 base and is rather more than i millimeter thick. 
 
 * For the demonstration of this subject no school should be without a good 
 model of the eye, in glass or pnpier mache, 10 times the natural size. 
 
6 CHAPTER I. 
 
 If we imagine the eyeball as representing the terrestrial 
 globe turned through 90 degrees, the front of the cornea 
 (O) will be the front pole, and the furthest back point of the 
 sclera (//) the back pole, and the straight line which 
 unites these two points is called the axis of the eye. 
 The equator of the eye runs around it, just where we 
 should place a knife to divide the eyeball into halves 
 horizontally, and the meridians connect of course the front 
 with the back pole. 
 
 FIG. I. 
 
 Behind the cornea is a space called the anterior chamber, 
 filled with a clear colourless liquid, the " aqueous 
 humour," which can be drawn off by puncturing the 
 cornea. This space or chamber is only from 2 to 3 
 
PREFATORY ANATOMICAL REMARKS. 7 
 
 millimeters in depth. At the back of the chamber lies the 
 iris (e), which is to the cornea what the dial-face of a 
 watch is to the glass. It is a ring-shaped, vascular 
 membrane, formed like a frame, at right angles 
 to the axis of the eye and having in the centre_a_ 
 hole or opening called the pupil (//') 
 
 The colour of the iris is different in different eyes; 
 for it is not the eye itself, but only the iris that is 
 blue, brown or grey. The iris of every new-born child 
 is blue, but grows darker-coloured in many cases within 
 the first few days. There is no such thing as a black 
 iris; even in negroes and Nubians it is only dark brown. 
 Light blue is the prevailing colour of the iris in Germany ; 
 out of 760,000 scholars in Bavaria, two-thirds were found 
 to have eyes of a light colour. The colouring matter 
 is stored for the most part behind the iris, but there 
 is no blue colouring matter in the iris itself; the iris only 
 appears to be blue through interference, if a dull or 
 colourless front layer of it occurs in front of the dark hinder 
 layer, just as a dark mountain range looks blue when seen 
 through a dense and misty stratum of air. But if the 
 front parts of the iris contain any colouring matter, then 
 the eye appears brown or grey or exhibits any conceivable 
 intermediate shade of colour. 
 
 In the centre or, to speak more strictly, a little lower 
 down and nearer to the nose, the iris is, as it were, 
 perforated by the pupil, which looks black, just as the 
 opening of an underground cellar looks black when seen 
 from the street. This opening is capable of being 
 dilated and contracted, but not by any effort of its 
 possessor. In the dark and in looking a long way off, 
 the pupil expands of itself, while in a bright light and in 
 looking at objects near at hand, it contracts. These two 
 movements are effected by two muscles situated in the 
 iris, the annular Sphincter Iridis which contracts it, and the 
 star - shaped Dilatator Iridis which expands. The 
 
3 
 
 CHAPTER I. 
 
 
 diameter of the pupil varies in the generality of cases 
 between 4 and 5 millimeters. There is, however, 
 a drug by means of which it can be expanded in 
 ten minutes to 9 millimeters ; while another drug has 
 the property of contracting it to the width of i milli- 
 meter. The dilatation is effected by Atropine, which is 
 obtained from the Atropa Belladonna or Deadly Night- 
 shade, and the contraction by Eserin, which is extracted 
 from the poisonous African plant Physostigma venenosum 
 or Calabar Bean. FIG, II. 
 
 The inner surface of the 
 sclera is covered by the 
 choroid membrane or chorio- 
 idea (m). This contains a 
 great number of small veins 
 supplying blood to the eye ; 
 it abounds also in a dark- 
 coloured pigment and, like 
 the sclera, has a central 
 opening which is filled 
 up in front by the iris. 
 Immediately behind the iris 
 it swells to a thick band, 
 6 millimeters broad, forming 
 what is called the ciliary 
 body. The latter consists of 
 two parts : the muscle, known 
 as the ciliary or accommoda- 
 tion muscle (/) (tensor 
 chorioideae), and an uneven, 
 more corrugated surface, facing 
 the centre of the eye, and called the ciliary processes 
 (processus ciliares) (p c \ We shall treat of these important 
 parts of the eye in greater detail further on. 
 
 Supposing an eye cut through along the line we 
 called the equator, the front half, when looked 
 
PREFATORY ANATOMICAL REMARKS. 
 
 FIG. III. 
 
 at from behind, would shew 
 us the ciliary processes 
 lying mostly towards the 
 centre, and forming a circle 
 of 70 72 folds. 
 
 The third membrane, con- 
 centric with the sclera and 
 the choroid, is the retina 
 (n). In a living condition 
 it is almost transparent, but 
 after death it is of a dull, 
 whitish colour. It extends 
 towards the front of the 
 eye as far as the beginning 
 of the ciliary body (or), and 
 ends there in a serratcc'. 
 margin the (pra serrata). 
 The retina is thickest near 
 the entrance of the optic 
 nerve (0*22 mm.) and de- 
 creases in thickness towards 
 the circumference, being 
 only 0*09 mm. thick at the 
 ora serrata. 
 
 The clear, white entrance of the optic nerve is seen, 
 not at the pole (//) but rather nearer the nose (no) ; and 
 the yellow spot (punctum aureum or macula luted], the spot 
 with which we see most clearly, is found at the place 
 marked (r), 3 mm. nearer the temple, and rather lower 
 down than the optic nerve. This yellow spot (Fig. V.) is 
 elliptical in form and lies horizontally ; it has in the 
 centre a highly transparent and very deep depression 
 called the fovea centralis. 
 
 The structure of the retina is extremely complex and, 
 when examined with the aid of a microscope, discloses 
 in section ten layers which are represented in Fig. II, 
 
IQ CHAPTER I. 
 
 (taken from the admirable researches of Max Schultze). 
 These layers, reckoning from the centre outwards to- 
 ward the choroid, are named as follows : i. The 
 inner limiting membrane. 2. Nerve - fibres or optic 
 nerve. 3. Layer of ganglionic cells. 4. Inner granular 
 layer. 5. Inner granular layer, larger size. 6. Outer 
 granular layer. 7. Outer granular layer, larger size. 
 8. Outer limiting membrane. 9. Layer of rods and 
 cones. 10. The epithelium or hyaloid membrane. 
 
 The most important of these ten layers, as far as our 
 sight is concerned, are the 2nd, 3rd, Qth and loth. 
 
 The second layer is that of nerve-fibres. When the 
 optic nerve has passed through the opening of the sclera 
 and the choroid (Fig. I. /.), the nerve-fibres of which 
 it is composed expand in every direction over the whole 
 retina as extremely delicate transparent fibrils 0*0005 to 
 0*0045 mm. in diameter. They surround the macula lutea 
 and are connected with the third layer of large ganglionic 
 cells. These ganglionic cells possess a cellular nucleus 
 and from two to six extended fibres. They are found 
 in the greatest numbers at the macula lutea, where they 
 overlie each other eight or ten deep (Fig. III. 3). 
 Towards the circumference the stratum of ganglionic cells 
 gradually decreases in thickness. 
 
 The ninth layer is that of rods and cones. This 
 layer is called by Ktihne the layer of optic cells. The 
 rods (Fig. II. 9) are long cylindrical figures, between 
 which lie the cones ; the latter are shaped somewhat like 
 a bottle, the neck looking towards the choroid and the larger 
 part towards the interior of the eye. Both the rods and 
 the cones have an inner (i) and an outer part (du). The outer 
 part is brilliant and streaked across ; the inner part is granu- 
 lated and less brilliant. The rods are only 0*0018 mm. in 
 breadth, while the cones are rather thicker, 0*004 mm - The 
 cone has at its termination a still slenderer rod, the cone- 
 rod, which measures only 0*001 mm. in diameter. 
 
PREFATORY ANATOMICAL REMARKS. 
 
 1 I 
 
 FIG. IV. 
 
 B 
 
 FIG. V. 
 
 The surface of the optic cells resembles a beautiful 
 piece of mosaic ; but the rods and cones are not 
 
 evenly distributed over the retina. 
 Cones alone are found at the 
 yellow spot, where they are clearly 
 visible like large circles (Fig, IV., 
 C) ; while towards the circum- 
 ference each cone is surrounded 
 
 by a circle of the smaller rods (Fig. IV., B and A\ 
 and on the margin of the retina, the cones disappear 
 altogether, to make room for the rods. 
 
 The connection of these 10 layers one with another is 
 
 not yet quite clear, as the 
 microscopic examination of this 
 _ part of the eye is extremely 
 difficult ; but it may safely be 
 taken for granted that the 
 nerve - fibres which enter the 
 retina through the optic nerves 
 are connected with the gangli- 
 onic cells, and through them 
 and the various granulated 
 layers with the rods and cones, 
 the latter being the true light- 
 receptacles and real nerves of sight. 
 
 Behind the rods and cones is the loth layer, which 
 consists simply of hexagonal cells containing a dark brown 
 
 FIG. VI. 
 
 Ch 
 
 pigment, known as Fuscin. The surface of these cells 
 is also like a delicate mosaic, and in examining them in 
 
12 CHAPTER I. 
 
 profile it is seen that they send out to the rods and 
 cones a large number of fine connecting threads re- 
 sembling eyelashes (Fig. VI., b and c\ 
 
 The macula lutea (Fig. III.) is distinguished by the 
 great number of gang] ionic cells and of cones, the latter 
 being found elongated and pressed closely together in 
 the fovea centralis or central depression of the yellow 
 spot. The space between the iris and the retina is 
 filled by the crystalline lens and the vitreous body. The 
 former (Fig. I., k] is enclosed in a very thin transparent 
 case or capsule, bi-convex in form, the front surface 
 being more slightly curved than the back. It is per- 
 fectly transparent, with great power of refraction, strong, 
 and at the same time soft and elastic. The margin of 
 the lens (Fig. I., x\ called the equator, is laminated ; it 
 possesses a skin and a nucleus, and can to some extent 
 alter its shape. In old age it becomes harder and 
 yellower. The dimness of the lens which occurs some- 
 times in later life is called cataract, and is a sign of 
 advancing years like the whitening of the hair; the pupil 
 looks grey instead of black, and the patient cannot see, 
 because the dulled lens cannot admit a sufficient amount 
 of light to the retina. 
 
 It is of the greatest importance to the right under- 
 standing of the hygiene of the eye, that the manner 
 in which the lens is securely fixed should be clearly 
 understood. The lens lies behind the iris and is 
 fastened to the ciliary body by a singular band called 
 the Ligamentum suspensorwm lentis or Zonula Zinnii 
 (Fig. X., Z). A horizontal section will shew us that 
 there exists a triangular space q between the equator of 
 the lens x and the ciliary processes n. This space is 
 called Petit's canal and is bounded by a delicate mem- 
 branous lamella at the Z and p ; Z being attached to the 
 front, and / to the back of the capsule of the lens. 
 These two delicate membranes join ? together at the 
 
PREFATORY ANATOMICAL REMARKS. 13 
 
 ciliary processes (n\ and are probably connected with the 
 hyaloid or vitreous membrane which surrounds the 
 vitreous bodies: Z is accordingly the front plate, and/ the 
 back plate, of the zonule of Zinn, or ligament which 
 suspends the lens ; and these plates fasten the capsule 
 of the lens to the ciliary processes. 
 
 The space between the iris and the lens (between T 
 and Z'm Fig. X.) is, in life, capillary and extremely narrow, 
 and is called the posterior chamber ; and behind the lens 
 lies the vitreous body (Fig. I., o] or corpus vitreum, which 
 keeps the sclera, choroid, and retina distended and fills up 
 the greater part of the eye. It is gelatinous, perfectly trans- 
 parent and surrounded by a delicate membrane called 
 the vitreous or hyaloid membrane. The optic nerve 
 enters the eye through an opening in the sclera and 
 choroid, rather nearer the nose than is the axis of the eye. 
 (Fig. I. No.) It is enclosed in a strong outer sheath q 
 and a more delicate inner one Z, between which a very 
 small dividing canal enters for some distance into the 
 sclera. The outer sheath v, and the canal ca will be 
 seen still more clearly in Fig, XXIII. The optic nerve 
 is made up of a great number of nerve-fibres passing 
 through a reticulated or sieve-like substance called the 
 lamina cribrosa (Ic in Figs. I. and XXIII.) in which they 
 lose their shining outer surfaces, and shewing themselves as 
 fine transparent cylinders in the sheath or papilla optica, 
 whence they radiate in all directions, as the delicate second 
 layer of the retina, being found, however, more freely dis- 
 tributed towards the inner than the outer side. Inside the 
 optic nerve we find the Arteria and Vena centralis retinae, 
 whose ramifications can be traced with the ophthalmoscope 
 from the spot where the nerve enters the eye to the remotest 
 parts of the retina (Fig. V.). The optic nerves them- 
 selves are insensible of light, in fact blind ; they merely 
 guide the impression of light to the brain, where they 
 cross and recross each other. 
 
14 CHAPTER I. 
 
 In addition to the parts of the eyeball just described, the 
 eye has a number of auxiliary apparatuses which, as they 
 are but remotely connected with the hygiene of the eye 
 in our schools, need find only a passing mention. The 
 eye can move without altering its place ; it is simply 
 turned, in any direction, upon its pivot, which is situated at 
 about the centre of the eyeball. This movement is 
 effected by six voluntary muscles. The four straight 
 muscles of the eye, or recti, originate at the back of 
 the eye near the point of the socket and have their 
 thin broad fibres inserted in the sclera towards the front 
 (Fig. I. s, t\ the upper, lower, and inner recti at about 
 5 mm. from the corresponding margin of the cornea, 
 the rectus externus at nearly 7 mm. from the outer margin 
 of the cornea. There are also two diagonal muscles, 
 or obliqui, which, however, do not concern us here. 
 These six muscles hold the eye in equilibrium, and 
 by the gradual successive contraction of one or more 
 of them the eye can be placed in any position desired. 
 In looking at objects close to us, the inner straight 
 muscles (recti interni) of the two eyes are moved 
 simultaneously. 
 
 The eyelid has a thin lining called the Tarsus, 
 between which and the outer skin lie fine muscular 
 fibres which extend in a circular direction from the 
 inner muscle of the eye to the outer, forming the muscle 
 by means of which we close the eye, and which is called 
 the sphincter palpebrarum or orbicularis. 
 
 Lastly, we must mention the connecting membrane or 
 conjunctiva, so called because it connects the eyelid with 
 the eyeball. It is a very thin, almost transparent mucous 
 membrane, by the aid of which the lid more easily rises 
 and falls over the eyeball. It lines the eyelid internally 
 and forms a reflecting fold from the lid to the eyeball, 
 which it keeps moist, and with the exception of the cornea, 
 covers. 
 
CH. II. PHYSICAL AND CHEMICAL PROCESSES OF SIGHT. 15 
 
 CHAPTER SECOND. 
 
 PHYSICAL AND CHEMICAL PROCESSES OF SIGHT. 
 
 In order to understand clearly the physical processes 
 of sight, a few remarks on the Camera Obscura will be 
 necessary as a preface. The Camera was invented in the 
 year 1560 by John Baptist Porta and is familiar to every 
 one now as the photographic camera, a dark chamber into 
 which the light falls only from the front. The light 
 there received passes through a bi-convex lens of glass ; 
 that is, a lens bounded on each side by a portion of a 
 spherical surface, a lens of the same shape indeed as the 
 spectacles worn by old people for reading. 
 
 p IG yjj Rays of light which come from 
 
 a great distance, from the sun 
 for instance, and which therefore 
 fall on the lens in parallel lines, are 
 gathered up by the lens into a 
 point called the focus (Fig. VII., 
 f) t where the sun-picture is in a 
 measure photographed. It has been 
 
 well remarked by Helmholtz that it is not generally 
 taken into account that the lens itself casts a shadow, 
 like an opaque body, though it is made of 
 transparent glass. The light is therefore gathered up by 
 the refraction of the glass lens, and directed to the bright 
 sun-picture, so that both light and heat are much more 
 intense there than in the unrefracted rays of the sun 
 (Lectures on Popular Science, II, p. 14). 
 
 But when the sun's rays reach the lens, not from 
 an infinite distance, but from luminous objects at a finite 
 
1 6 CHAPTER 11. 
 
 distance, they form beyond JT IG< vill. 
 
 the glass a miniature 
 picture in inverted posi- 
 tion, which can be captured 
 in the air. In Fig. VIII. la 
 is the inverted picture a 
 of bv. If we hold a 
 photographic lens at a 
 certain distance from a sheet of paper held opposite 
 a window, we can easily throw upon the paper a small, 
 inverted picture of the window. The picture is best seen, 
 when no light falls upon it from the sides, and that is 
 why the sides of the photographic chamber are closed 
 so as to exclude all side-lights and to allow the inverted 
 picture thrown from the lens to be exactly caught 
 on the ground glass at the back of the camera. 
 
 The place at which the picture appears depends alto- 
 gether upon the degree of convexity of the lens ; for 
 the more convex the lens is, the nearer to it will be the 
 place of the picture ; and the flatter the lens, the farther 
 from it will be the picture. In the former case the 
 lens is said to have a short focal distance or a strong 
 power of refraction, and in the latter, to have a great 
 focal distance or a weak power of refraction. 
 
 Some years ago boxes of glasses or of spectacles were 
 used, containing a succession of convex lenses, the focal 
 distances being measured by inches and indicated by 
 fractions of which i was the numerator, while the de- 
 nominators expressed the focal distances in inches. Thus 
 a glass marked 1 /2 meant a glass of which the focal 
 distance measured two inches ; : /4, a glass of which the 
 focal distance measured four inches ; 1 /io, a glass of which 
 the focal distance measured 10 inches, and so on. 
 
 More recently, however, measurement by meter has 
 come into use even for spectacles, and has introduced 
 the idea of Dioptrics. The dioptric unit is the refracting 
 
PHYSICAL AND CHEMICAL PROCESSES OF SIGHT. 
 
 power of a lens, whose focal distance is i meter. 
 Spectacles are now numbered, not in fractions inversely 
 proportional to focal distances, but in whole numbers 
 directly proportional to powers of refraction. Such glasses 
 are called metric or dioptric lenses ; thus No. i dioptric^ 
 lens (No. i D) is a lens of such refracting power 
 that its focal distance is i meter. If a second lens of 
 the same power is placed over it, we obtain a lens, No. 
 2 D y of which the focal length is of course half a 
 meter. A lens No. 10 D has a focal length of 10 
 centimeters or one-tenth of a meter, and so on. According 
 to the old style of measurement No. l /2 is the strongest, 
 and No. ^120 the weakest lens. In dioptric lenses No. 
 0*25 D is the weakest and No. 20 D the strongest. 
 
 The stronger the refracting power of the lens in the 
 camera, the nearer of course must be the screen or 
 plate which is to receive the picture : therefore with a 
 lens No. 10 D the plate must be 10 centimeters distant; 
 but with + 5 D (+ means convex) it must be ! /5 f a 
 meter or 20 centimeters distant. The chamber must there- 
 fore be shorter from 
 front to back, the 
 stronger the refract- 
 ing power of the 
 lens at its entrance. 
 It need hardly be 
 j said that we are pre- 
 supposing a perfectly 
 clear, bright lens, if the picture on the plate is not 
 to be blurred and indistinct. 
 
 But the clearest lens will not prevent the picture from 
 being indistinct, if the plate is further from the lens than 
 the refracting 1 power of the glass demands. If the 
 screen 5 5 (Fig. IX.), which received at v a clear sharp 
 picture of the point /, were moved forward to a b, the 
 picture at v would be indistinct, and the same effect would 
 
 FIG. IX. 
 
1 8 CHAPTER II. 
 
 follow if the screen were put back to c d. For the rays 
 of light, although gathered near to each other, form on 
 the plate moved forward to a b y a circle, an indistinct 
 circle, a so-called circle of dispersion, of which the diameter 
 is m n\ and if the plate is moved back again to c d y the 
 rays of light, which are now divergiug from v> form 
 again upon the screen a circle of dispersion of which the 
 diameter is g e\ for rays always diverge from a luminous 
 point into which they have been gathered, and therefore 
 in the present instance they diverge from v. It follows 
 that a distinct picture is only possible when the screen is 
 at the exact distance from the lens required by the re- 
 fracting power of the latter. 
 
 We must, indeed, modify the above remarks when the 
 rays diverge from a point extremely near the lens : the 
 picture in that case, from causes which it is not neces- 
 sary to explain here, will fall somewhat further beyond 
 the focal distance of the lens, and the plate of the 
 camera will have to be drawn back so as to be 
 further from the front. 
 
 The process of photography corresponds very closely 
 to the process by which a picture is formed in the 
 eye : for the eye, too, is a camera obscura, enclosed in 
 a round instead of a square case. For, as we said 
 in the last chapter, the choroid membrane abundantly 
 contains a dark pigment. This corresponds to the black 
 lining of the photographer's camera ; and the eyeball, 
 although not hollow like the camera, is filled with trans- 
 parent fluids, while instead of the single photographic 
 lens we have in the eye several refracting media, namely, 
 the convex, transparent cornea, of which the curve and 
 position cannot be altered, the aqueous humour, and the 
 crystalline lens itself. 
 
 When the rays have passed through these three trans- 
 parent media, they do not enter into air, but into the 
 vitreous body which refracts them more strongly than air 
 
PHYSICAL AND CHEMICAL PROCESSES OF SIGHT*. 19 
 
 can do ; so that, having more highly refracting parts, 
 the eye has of course a much higher refracting power 
 than the photographic apparatus ; accordingly upon the 
 retina at the back of an eye, only i inch in depth, 
 a clear image is produced. We see now why -the 
 cornea, aqueous humour, crystalline lens and vitreous 
 body are termed the refracting media or dioptric apparatus. 
 
 The work of the sensitive plate of the photographer 
 is done in the eye by the retina and its optic cells. 
 The clearest picture is obtained at the yellow spot at 
 the end of the axis of the eye. Kepler was the first 
 to show on optical grounds that a diminished, inverted 
 image must be formed upon the retina ; and so early 
 as the year 1619 the famous Father Joseph Scheiner 
 demonstrated at Rome this little picture traced at the 
 back of a human eye. In spite of these authorities 
 it was thought by many, even as recently as our own 
 century, that the choroid was the membrane on which 
 the picture was obtained ; but it is now positively estab- 
 lished that it is traced nowhere else but in the rod- 
 and-cone stratum of the retina. 
 
 Lastly, we find in the photographic camera the 
 diaphragm, an important apparatus in the formation of 
 the picture. The rays which pass through the edge of 
 a lens are refracted much more strongly and irregularly 
 than those which pass through the centre. In order 
 therefore to obtain as clear a picture as possible upon the 
 sensitive plate, the side-rays which enter the camera 
 obscura (as in any other optical instrument) are intercepted 
 by diaphragms. This work is done in the eye by the 
 iris, which prevents the rays of light from passing 
 through the edge of the lens. The iris regulates also 
 the amount of light, contracting the pupil in a bright 
 light so as to allow a smaller number of rays to strike 
 the sensitive retina, and expanding in a dim light so as 
 to admit as many rays as possible. 
 
20 CHAPTER II. 
 
 The process by which the picture is produced in the 
 eye is not the only one which resembles photography, 
 as we shall admit when we turn to the chemistry of 
 vision. The photographer moistens his plate with iodide 
 of silver ; all light parts of the object decompose the 
 iodide and leave on the corresponding place a dark 
 picture, while dark objects do not decompose the iodide. 
 In this way the photographer obtains a negative from 
 which he afterwards prints off a positive. 
 
 Now in the year 1876 Ball made the significant dis- 
 covery that the retina of living animals was of a reddish 
 purple colour, which became pale at the expiration of 
 scarcely a minute ; and further, that the colour which 
 disappeared from the retina of frogs dazzled by a strong 
 light came back in the dark. 
 
 Upon this, Klihne proved that light was the sole reason 
 of this loss of colour, and that the colouring matter or 
 Rhodopsin was contained in the rods, the cones being 
 entirely destitute of it. He was able by means of gall to 
 extract the rhodopsin from the rods and to study its 
 photo-chemical properties outside the body of the animal. 
 In the living eye the rhodopsin can of course be driven 
 out only by strong light, and Klihne succeeded in taking 
 real optograms (impressions akin to photographs) on the 
 retina of animals. The animals were previously kept in 
 the dark for a long time to favour the accumulation of a 
 large quantity of colouring matter ; they were then held 
 for a moment in front of a window upon which some 
 strips of dark paper had been pasted, and their heads 
 were immediately cut off. The retina was then found to 
 have traced upon it, in a red colour, only those parts of 
 the window upon which the dark paper had been 
 fastened, while in every other part it was colourless from 
 the effect of the light. 
 
 The restoration of the colouring matter is effected by 
 the epithelial cells of the loth layer of the retina. The 
 
PHYSICAL AND CHEMICAL PROCESSES OF SIGHT. 21 
 
 chemical changes of the optic cells produce, most probably, 
 further chemical changes in the ganglionic cells and nerve- 
 fibres which lie in front of them ; the latter pass through 
 the optic nerve into the brain, where alone, and not in 
 the eye itself, is the home of sight. 
 
22 CHAPTER III, 
 
 CHAPTER THE THIRD. 
 
 ACCOMMODATION. 
 
 Photography has at its command three methods by 
 which it can obtain pictures of objects near at hand. 
 The first of these is the drawing out of the ground glass, 
 on which the picture is taken, further back from the 
 front lens. If the eye could imitate this method, it would 
 be by moving the retina further back when we look at 
 near objects. But the eye has no power to do this. 
 
 The second method employed by photographers for the 
 same purpose leaves the ground glass unmoved, but aUers the 
 position of the front lens, moving the lens forward by means 
 of a screw, and so increasing the distance between it 
 and the ground glass ; for, the nearer the object, the 
 further the lens must be pulled out, and the further off 
 the object, the more the lens must be screwed back. 
 If we had such a method of thrusting forward the 
 crystalline lens of the eye we should be able by 
 employing it to obtain pictures of near objects on the 
 retina. But this power also is denied to the eye. 
 
 Lastly, the photographer has a third method of obtain- 
 ing the impression of near objects upon the plate, without 
 either drawing out the plate further back, or moving the 
 lens further forward. He has only to place before the lens, 
 while leaving both it and the plate in their original 
 position, a second, third, and fourth lens, indeed as many 
 additional lenses as are needed by the greater nearness of 
 the object which he intends to photograph. A lens of 
 double power has exactly the same power of refraction 
 as two lenses of equal power placed one before 
 
ACCOMMODATION. 23 
 
 other. If, therefore, the eye possesses a mechanism by 
 which it can give to its lens, without displacing it, a 
 greater or less degree of convexity, that is, can, as it 
 were, place before it a second lens, can make its lens 
 thicker, it will be able to see clearly both near and 
 distant objects. And this most important mechanism the 
 eye does actually possess, in what is called Accommodation. 
 
 The greatest thinkers have mastered a host of diffi- 
 culties in discovering this arrangement, and it is only in 
 very recent times that its processes have been clearly and 
 perfectly set forth in the works of Sanson, Helmholtz, 
 Briicke, Hensen and Volckers. 
 
 The crystalline lens is elastic, and would, if left to itself, 
 assume a much more spherical form than it has in life. 
 
 FIG. X. 
 
 There exists, however, a muscle at the margin of the 
 lens which, by contracting, flattens it permanently, so as 
 to make it throw upon the retina the impression of 
 distant objects. This muscle, which surrounds the lens in 
 radiating folds not unlike a frill, is called the Zonula 
 
24 CHAPTER III. 
 
 Zinnii or Ligatorium suspensorium lentis (Fig. X., Z.) It 
 is attached to the ciliary processes and flattens the lens 
 by expanding it towards the circumference. The tension 
 of the ligament can be diminished by the ciliary or 
 accommodation muscle which is found in the ciliary body. 
 This muscle begins behind the margin of the cornea at 
 (K) and reaches back to the choroid membrane (f) ; by 
 contracting, it draws the choroid forward, the ciliary pro- 
 cesses moving with it in the same direction (n), and, since 
 the zonula (Z) is attached to the latter, it also is moved 
 forward by the contraction of the ciliary muscle. 
 
 The forward movement of the zonula forces the lens 
 in obedience to its elastic properties to assume a thicker 
 and more spherical form instead of the flattened form it 
 has when at rest. The front surface of the lens in 
 particular becomes much more convex, and has in a 
 measure the same effect as that produced by placing a 
 second lens in front of the first without altering the 
 position of the first, and thus of F XJ 
 
 course the lens is made to pro- 
 ject on the retina the picture of 
 near objects. The eye is in this 
 manner accommodated, or focussed, 
 for near objects. The upper half 
 of Fig. XI. shews us the working 
 of the accommodation muscle for 
 near sight, and in the lower half 
 we see the situation of the various 
 parts when accommodated for far sight. 
 
 The radiating fibres of the accommodation muscle work 
 as we have described ; but there are within the same 
 muscle circular muscular fibres lying nearer to the edge 
 of the lens (Fig. X. /), which by their contraction 
 relax the zonula still more. 
 
 Hensen and Volckers have by their recent experiments 
 shewn what Brucke^ the discoverer of this muscle, had 
 
ACCOMMODATION. 25 
 
 already suspected, that the choroid is really drawn 
 somewhat forward by the contraction of the accommodation 
 muscle and that in this . way the zonula is relaxed. 
 They introduced a needle into the ciliary muscle of a 
 dog somewhere near the place marked / in Fig. X. 
 while they passed a second needle through the sclera 
 and choroid (say behind t in Fig X.); and while the 
 first needle remained perfectly stationary during the 
 excitation of the accommodation muscle, the free end of 
 the other needle moved quickly backward, which would 
 have been quite impossible without a forward movement 
 of the choroid. 
 
 Now it is upon this very accommodation muscle that 
 in reading and writing we impose a twofold burden ; 
 on the one hand it is made to relax the zonula and by 
 so doing to bring the lens into a more spherical form, 
 and on the other hand it is made to draw the choroid 
 forward. And this twofold work is a main source of 
 injury to the youthful eye, so that it is impossible to 
 lay too much stress upon the right understanding of this 
 mechanism of accommodation. 
 
 NOTE. A little model of the accommodation muscle has been prepared according 
 to my instructions by the optician Heidrich, 27, Schweidnitzer Strasse, Breslau. 
 
20 CHAPTER IV, 
 
 CHAPTER FOURTH. 
 
 ACUITY OF VISION. 
 
 The delicacy of the sense of touch is estimated by 
 the power of distinguishing on the skin two separated 
 points of a pair of compasses, which points a duller 
 sense would only feel as one. At the tip of the tongue 
 they can be distinguished when they are only one mil- 
 limeter apart ; on the end of the finger not until they are 
 2 mm. apart, on the hand not within 20 mm., on the neck 
 not within 30 mm., and on the upper part of the arm 
 not within 60 mm. 
 
 In the same way we estimate fineness of vision, acuity 
 of vision, by the power of distinguishing two dots lying 
 near together and seen of course under a good light. 
 The distance at which these dots can be seen as two 
 clearly separate objects will depend upon the distance 
 apart at which their images are traced upon the retina, 
 and that distance will itself depend upon what is called 
 the angle of sight, or in other words the angle formed 
 by two straight lines drawn from the two points to 
 the optic centre of the eye. By the optic centre of 
 the eye is meant the optic centre of the refracting sur- 
 faces of which the eye is composed. This point is 
 situated about half a mm. in front of the posterior 
 surface of the lens (Fig. I. Kn). All the rays of light 
 which pass through this point are continued unrefracted. 
 If from the ends of an arrow (AB Fig. XII.) two 
 straight lines are drawn to the optic centre k and are 
 produced, they strike the retina at the points d and c. 
 
ACUITY OF VISION. 
 
 These lines are called lines of direction, and the optic 
 centre is their point of intersection. 
 
 FIG. XII. 
 
 FIG. XIII. 
 
 The angle AkB, or 7, contained by these two lines is 
 the angle of sight. AkB is of course equal to dkc. 
 
 The further a given object is from the eye, or the 
 smaller the object at a given distance, the smaller will 
 be the angle of sight (Fig XI 1 1.); and it will eventually 
 be so small that the points A and B can no longer 
 be distinguished upon the retina as separate points. 
 The size of the picture upon the retina can be easily 
 calculated from the angle of sight 7. 
 
 If the latter equals i minute ^/GO of a degree), the 
 size of the retina picture in the normal eye will be 
 0*0043 mm - Now each cone-rod is only o'ooi mm. 
 in diameter, so that if 7 = i' and the retina picture 
 is accordingly 0*004 mm. wide, the bright points A and 
 B strike two cone-rods which do not lie close together, 
 and consequently A and B are distinguished as two 
 separate points. 
 
 The angle of sight of i' was taken by Prof. Snellen 
 of Utrecht as a standard measure of acuity of vision. 
 He constructed letters and characters such as to be seen at 
 a given distance at an angle of i minute. In individual 
 
28 CHAPTER IV. 
 
 sases the acuity of vision (V) is determined by finding 
 the minimum, angle required for the recognition of the 
 letter or character. 
 
 No school library should be without a copy of Snellen's 
 Test Types or Opto-Typi (published by Peters, Berlin.) 
 These test types are so made that each thickness of a 
 letter and every narrow space left between the separate 
 parts measures J /5 of the height of the whole letter. 
 If, then, such a letter is seen by the eye at an angle 
 of sight of x /i2 degree, or 5', each separate part of the 
 same letter will be seen at an angle of i'. Above 
 each line of letters Snellen has printed the number of 
 meters which expresses the distance at which the letters 
 are when the angle of sight is 5'. 
 
 Accordingly if we find the figure 6 above a line of 
 the printed letters, we know that they will be seen by 
 the eye at a distance of 6 meters at an angle of sight 
 5', and each separate thickness of the letter at an angle 
 of sight i'. If, then, these letters are read by the 
 eye up to a distance of 6 meters, its acuity of vision 
 V = 6 /6 = i ; while, if they are read only up to a distance 
 of 3 meters, the acuity of vision V = 3 /e = x /2, and in that 
 case the separate parts of the letters are not distinguished 
 at a less angle of sight than 2. But if an eye could 
 see the types at a distance of 12 meters, V would be 
 12/6 or 2, and the same eye would see clearly at an angle 
 of x /2 a minute, in other words would have double acuity 
 of vision. Acuity, then, is generally expressed by a 
 fraction of which the denominator (D) indicates the number 
 of meters marked above the letters, which number shews 
 the distance up to which the letters are read by the 
 normal eye, while the numerator (d) shews the distance 
 up to which they are actually read by the eye which is 
 being tested. Thus V ^ 
 
 In Fig. XIV. we copy some letters taken from No. 6 
 of Snellen's Test Types, - and any one who is unable to 
 
ACUITY OF VISION. 
 
 read them easily at a distance of 20 feet has less than 
 normal visual acuity. The test types have, besides 
 
 separate letters, whole 
 
 o^gfe EBI Bsraet "Tr- 1 ! paragraphs printed in 
 
 D ' different sizes, and the 
 
 ^ distances are given at 
 
 which they are seen 
 
 LT% W*9 T" at an an ^ e of 5 '* 
 JLJ? 4U JL The shape of the 
 
 letters is of great im- 
 
 FHM i$p| Bfli portance. Mauthner 
 ^J ^^J ^ as ver y tru ly observed 
 that the Latin O is 
 
 much more easily recognised than the spaces in C and 
 G are distinguished from the space in O. Now what 
 we have to aim at is that the letters should not be 
 guessed at but clearly recognised. 
 
 For the testing of very young children and of those 
 who are unable to read, Snellen has published types 
 made according to his system and containing, instead of 
 letters, characters somewhat like the following: LJ PI C 3* 
 The child has only to be asked whether they are open at 
 the top or at the bottom, on the right side or on the left. 
 Mayerhausen has recently preferred Arabic numerals to 
 the letters contained in Snellen's test types. 
 
 The tests most mathematically correct are the point 
 tests constructed by Dr. Burchardt of Berlin and called 
 International Sight Tests ; but for use in schools Snellen's 
 test types are, for practical reasons, better fitted. 
 
 De Haan, a pupil of Bonders, has by the aid of 
 Snellen's types determined V for different ages and found 
 that up to the age of thirty V generally remains almost 
 unaltered at 22 / 2 o, that at forty years of age the average is 
 20 / 20 , at fifty 18 /2o, at sixty 14 /20, at seventy 12 / 20 , and that at 
 eighty it has fallen to 10 /2o> or just half the acuity of a healthy 
 normal eye. The reason of this not very consolatory 
 
3O CHAPTER iv. 
 
 phenomenon is sought for by De Haan and Bonders in the 
 diminished transparency of the lens and of the vitreous 
 humour and partly in some alterations in the retina, the 
 optic nerve and the brain, not as yet understood. But these 
 statements concerning the gradual failure of acuity cannot 
 claim universal authority because they are based upon the 
 examination of too small a number of cases, namely, 
 281 in Holland.* 
 
 As far back as the year 1871 I had pointed outt 
 that the eyes of children living in a mountainous region 
 had when in a healthy condition a much greater acuity of 
 vision than that given by Snellen as normal. At 
 Schreiberhau in the Riesengebirge I examined 244 eyes 
 of the village-school children, and found that only 7 saw 
 the hooked characters of Snellen's test table No. 20 finally 
 at 20 feet ; while 38 saw them finally at between 22 and 
 29 feet, 85 at between 30 and 39 feet, 104 at between 40 
 and 49 feet, and 10 at the great distance of between 
 50 and 60 feet. Thus it is quite usual to find among 
 young people eyes possessing twice the keenness of 
 sight given by Snellen as normal ; even treble acuity 
 was found. I obtained a similar result with Dr. 
 Burchardt's point tests. 
 
 Burchardt made the same experiments with the eyes of 
 soldiers, and found that out of 474 eyes only 61 had 
 V < i, while 43 had V = i, 281 had V > i and < 2, 73 
 had V = 2, 1 6 had V 2^3 and 2 l /&. (He very properly 
 judges from these results, that men having such a keen 
 sight ought not to be employed in the railway-battalion 
 or in ambulance or transport service, but should be 
 reserved for the infantry and artillery). Reich also has 
 found that 32/ of the Georgian Infantry in the Caucasus 
 have twice the normal V. 
 
 The keen sight of uncivilised races has long been 
 
 * H. Cohn, Die Augen der Greise. Tagebl. d. Naturf. -Vers. Breslau 1874. 
 t H. Cohn, Die Refraction der Augen von 240 atropinisirten Dorfschulkindern. 
 A. v. Graefe's Archiv. XVII. II. 
 
1 
 
 UNI 
 
 OF 1 
 
 ACUITY OF VISION. 31 
 
 known. Humboldt* relates that his friend Bonpland, who 
 had ascended the basalt cone of the Pichincha, more than 
 three geographical miles distant, was seen by the Indians 
 with the naked eye before he himself could discover 
 him with the aid of a telescope. But no scientific 
 examinations of tlfe V of uncivilised races were in- 
 stituted till a recent date. The presence of the Nubians 
 in the Zoological Garden at Breslau made for the first 
 time such an examination possible. tl tested them with 
 Snellen's point tests, with the result that points which 
 the ordinary European can only count up to a distance 
 of 1 6 meters were counted by them up to 26 'meters, 
 30 meters and in some instances up to 39 meters. It 
 is, then, nothing extraordinary for a Nubian to have 
 twice the normal V. The same result was obtained 
 by KotelmannJ and Stein, who examined later the eyes 
 of other Nubians and of Laplanders and Patagonians in 
 the Zoological Gardens of Hamburg and Frankfort-on- 
 the-Main respectively. 
 
 My experience in Schreiberhau did not enable me to 
 confirm De Haan'sll statements as to the failure of V 
 in old age. De Haan's results were obtained from an 
 examination of not more than 41 persons above 60 
 years of age, and even of these there were more 
 than 13 with diseased eyes, so that his law as to 
 the rapid failure of V after the age of 60 is based 
 upon the examination of only 28 persons. But statistics 
 prove nothing, unless they are many. 
 
 At Schreiberhau, which up to that time was a very 
 uncultured mountain village, where few, if any, of the old 
 people had learned to read, so that their eyes were still 
 
 * Kosmos, Bd. III. p. 69. 
 
 t H. Cohn, Sehscharfe and Farbensinn der Nubier. Centralbl. f. Augenheikunde 
 1879. Juli. 
 
 J Berl. klin. Wochenschr. 1879, No. 47. 
 
 Frankfurter Zeitung 1879, No. 213. 
 
 II Onderzoekingen naar den invloed van der leeftijd op de gezigtsscherpte. Dissert. 
 inaug. Utrecht 1862. 
 
32 CHAPTER IV. 
 
 almost in their normal condition, I was able to establish 
 in the year 1874 that among 100 persons who were 
 more than 60 years of age 34 eyes had V = i and 88 
 eyes had V > i. Of the latter, 70 saw the hooked 
 characters up to a distance of between 21 and 30 feet 
 instead of up to 20 ; 17 up to between 3 1 and 40 feet, 
 and i up to a distance of 42 feet, who thus possessed 
 twice the normal acuity of vision. The average V in 
 that place for 60 or 70 years of age was 27 /2o and for 80 
 years of age^ 26 / 2 o- 
 
 It would be a most desirable thing to discover a law 
 of average power of sight ; but in order to do so it 
 would be necessary to examine great masses of persons 
 in towns and country places, among civilised and uncivilised 
 races, in different nations and classes of life, and in 
 valleys and on mountains. 
 
 The illumination exercises of course a great influence 
 upon acuity of eye-sight. In default of a photometer for 
 the light of day, we are unfortunately left to our own 
 eyesight for all practical purposes ; and if with a certain 
 degree of daylight our own normal eye has V depressed 
 below 5 /6, we cannot reasonably demand that another person 
 with the same degree of daylight should have F= 6 /6. 
 
 We must add in conclusion that the eye has not 
 only a central but an excentric and much more im- 
 perfect acuity of vision, for light affects not only 
 the macula lutea (yellow spot) in the centre of the 
 retina, but every part of the retina where we find 
 rods and cones. 
 
 We can easily convince ourselves by experiment 
 that, if we close the right eye and with the left 
 eye look at a finger held up in front, we are able 
 at the same time to count the number of fingers held 
 up by another person above, below, to the right or left 
 of this central finger. This is, however, only possible 
 within certain limits, and the extent of surface within 
 
ACUITY OF VISION. 33 
 
 which, while looking at an object placed centrally before 
 
 the eye, we can perceive at the same time objects placed 
 excentrically is called the field of vision. 
 
34 
 
 CHAPTER V, 
 
 CHAPTER FIFTH. 
 
 REFRACTION. 
 
 The term "refraction of the eye" is used for the 
 refracting power of the eye in repose, without any 
 exertion of the accommodation muscle. 
 
 The year 1860 was an epoch in the study of our 
 present subject, for it was early in that year that 
 Bonders published his lucid works, which have cleared 
 away the great confusion previously existing among 
 scientific men respecting accommodation and refraction. 
 
 Refraction is normal, that is, the axis of the 
 eye is of the normal length, when rays of light which 
 
 FIG. XV. 
 
 U 
 
 come from infinite distance are focussed exactly upon the 
 retina itself. In such a case we say that the refraction 
 
REFRACTION. 35 
 
 of the eye is emmetropic. (from emmetros, "of the 
 right measure" and ops, " the eye.") (Fig. XVI.) 
 
 Again, the axis of the eye may be too short, so that 
 rays coming from infinite distance are focussed at a point 
 behind the retina ; this refraction is termed hypermetropic 
 ("going beyond the measure") or hyperopic (Fig. XVI.). 
 This hyperopia must in no way be confounded with 
 that long sight often noticed in old age, when the patient 
 sees clearly only things at a distance, a defect caused 
 by weakness of accommodation. 
 
 Lastly, the axis of the eye may be too long, so that 
 rays from infinite distance are focussed in front of the 
 retina (Fig. XVII.). This kind of refraction is called 
 short-sighted or myopic (from muein, " to blink " and ops, 
 "the eye") because most short-sighted people nearly close 
 their eyelids when they try to look at any distant 
 object. 
 
 Thus hyperopia and short sight are true opposites. The 
 one excludes the other/ The hyperopic eye has the axis 
 too short, the short-sighted eye has the axis too long. 
 Hyperopia and myopia are both of them diseases of the 
 eye's refraction, or defects in the length of its axis. 
 
 But there is yet another defect caused by a want of 
 symmetry in the curvature of the different meridians of 
 the eye's dioptric system. In this case the eye has 
 different degrees of refracting power in different meridians, 
 so that the rays, instead of meeting in .a /0z>z/-focus, 
 meet in a fine-focus. This fault of refraction we call 
 astigmatism. Any one born with this defect, soon 
 becomes conscious of a weakness of vision which leads 
 him to seek the advice of an oculist, and very often 
 it is possible greatly to improve the V by specially 
 adapted cylindrical glasses. The examination and diagnosis 
 
 * Leaving out of account the defect of astigmatism, mentioned in the next paragraph. 
 It is possible for the same eye to be hyperopic in one meridian and short-sighted in 
 another, English Ed< 
 
36 CHAPTER V. REFRACTION. 
 
 of this defect are not easy ; and, as it has no immediate 
 connection with school work, we may content ourselves 
 with simply mentioning it. 
 
.CHAPTER vi. HYPEROPIA.* 37 
 
 CHAPTER SIXTH. 
 
 HYPEROPIA. 
 
 In this form of refraction, as we have already explained, 
 rays coming from infinite distance are focussed behind 
 the retina, because the axis of the eye is so short that 
 the retina lies in front of the focus of the dioptric ap- 
 paratus. What rays of light then do unite on the retina 
 in a case of hyperopia ? Only those which, when they 
 enter the eye, are converging to a point behind the 
 retina (m in Fig. XVI 1 1.). Precisely these are so 
 
 F,c. XVIII. refracted in the 
 
 eye that they unite 
 on the retina at o. 
 These rays have been 
 called "superinfinite," 
 because their point 
 of origin lies, so 
 to speak, beyond infinite distance or, more strictly speak- 
 ing, at a finite distance behind the eye. It was this reason 
 which caused Bonders to choose the term " Hyperopia" 
 (abbreviated into //) to express the power of seeing 
 clearly beyond the normal length of sight, beyond infinite 
 distance. 
 
 These superinfinite, convergent rays have no natural 
 existence on earth ; but they may be at any moment arti- 
 ficially produced by causing parallel rays to pass through a 
 convex lens so that they become convergent (Fig. VI I./). 
 Hyperopia is, therefore, that condition of the eye's 
 
3& CHAPTER VL 
 
 refraction in which the 
 rays of light can only 
 be focussed upon the 
 retina after being 
 passed through a con- 
 vex lens (Fig. XIX.). 
 
 The degree of refracting power of a lens which 
 makes the rays of light so convergent that they meet 
 at a point upon the retina is the degree of the 
 hyperopia of the eye. For instance, any one who 
 cannot read the letters on No. 6 of Snellen's Test 
 Types (Fig. XIV,) with the naked eye at a distance 
 of 6 meters, while he can read them easily by looking 
 through a convex glass + i,oZ? (or, according to the old 
 inch-measurement, through a glass + 1 / 4 o), is said to have 
 hyperopia H iD (or = I /Q according to the old reck- 
 oning) ; that is, the far-point is i meter, or about 40 
 inches, behind his eye ; and any one who needs a 
 convex glass + loD in order to see clearly at a distance 
 has hyperopia = 10, &c. 
 
 Thus the strongest convex glass through which any one 
 can clearly see distant objects gives the degree of his 
 hyperopia. 
 
 This test pre-supposes of course that the accommoda- 
 tion of the eye is in absolute repose, which, however, 
 is not always the case in the testing of hyperopic eyes. 
 And for this reason. The hyperopic person cannot see 
 distant objects clearly without the aid of accommodation, 
 while he sees them better the moment he accommodates, 
 or more strongly curves, his lens ; for thus, if the 
 degree of hyperopia is slight, he is able to correct the 
 defect due to the form of his eye by placing, as it 
 were, before his reposing lens, by means of accommoda- 
 tion, the proper convex lens. But by this ' effort he 
 often loses in course of time the power of- entirely 
 relaxing the accommodation ; indeed he almost always 
 
HYPEROPIA. 39 
 
 involuntarily contracts the accommodation muscle even in 
 looking at distant objects. 
 
 In this way it is possible for young hyperopes to 
 maintain that they cannot see so well through the proper 
 convex glasses as they can without them. The fact is 
 that they make use of accommodation even when wearing 
 the glasses. From the same cause it is very difficult to 
 determine, by the aid of glasses alone, the true degree 
 of H. To do this, the oculist must make it impossible 
 for the patient to exert the accommodation. The oculist 
 therefore drops atropine into the eye. This paralyses 
 the accommodation and makes it possible to estimate by 
 convex glasses the total degree of hyperopia, (H*). 
 
 This H* consists, therefore, of (i) the patent, manifest 
 hyperopia (H m ), which was discovered by the glasses 
 alone without the aid of atropine, and (2) the latent 
 hyperopia (H 1 ), which was not revealed until the atropine 
 had been dropped into the eye. 
 
 This circumstance is of great importance in testing the 
 eyes of school children (as we shall shew in Chap. VIII.). 
 
 There is a form of hyperopia with which a person 
 is able, by the aid of accommodation, to see distant 
 objects clearly even without convex glasses (and without 
 squinting). This is called facultative hyperopia (Hf). 
 
 Now as the hyperopic person is obliged to exert the 
 accommodation muscle even to see clearly at a distance, 
 he has, as Bonders very justly says, to begin, even for 
 far vision, with a deficit. In youth, when the accommo- 
 dation works very readily, a slight degree of hyperopia 
 seldom makes its presence disagreeably felt. It is with 
 more advanced stages of the defect, and in later years, 
 that fatigue is caused by near work through the over 
 strain of the accommodation muscle, a muscle which 
 even for far sight has to make up a deficit. 
 
 F^r the moment, the accommodation muscle answers 
 to the call made upon it, but the effort is too great to 
 
40 CHAPTER vi. HYPEROPIA. 
 
 be long sustained, and soon brings on pain in the eye, 
 and pain and a sense of strain above the eye. ' The 
 sufferer has what is called accommodative asthenopia, i.e., 
 loss of power to see near objects, a loss which, however, 
 can easily be remedied by proper convex glasses. 
 Persons afflicted in this way are often thought upon a 
 superficial examination to be short-sighted, or to have 
 weak sight ; but a more thorough investigation, conducted 
 with glasses and confirmed by the ophthalmoscope, soon 
 makes it evident that the case is really one of 
 hyperopia. 
 
 It is often of great consequence to provide betimes 
 the proper convex spectacles, for H easily induces an 
 inward or convergent squint. 
 
 The hyperopic structure is almost always congenital 
 and is often hereditary. It is never acquired by over- 
 exertions or activity ; and it causes no very grave 
 dangers to the eye. The annoyances due to it can 
 easily be remedied with the proper spectacles. Hyperopia 
 can never be a subject for preventive treatment for 
 prophylaxis. 
 
CHAPTER VII. JMYOPIA (SHORT SIGHT j. 4! 
 
 CHAPTER SEVENTH. 
 
 MYOPIA (SHORT SIGHT). 
 
 The exact opposite of hyperopia is myopia (abbreviated 
 into M). The axis of the eye is too long (Fig. XVII.). 
 Rays of light falling parallel upon the eye from infinite 
 distance meet in a point before they reach the retina, 
 and, diverging again from that point, form upon the 
 retina a circle of diffusion. But rays of light which 
 FIG. XX. diverge from a 
 
 certain point at 
 a finite distance 
 
 -^e&^f meet in a P int 
 
 :::: - \^~j^i**^^- A u P on tne retina 
 
 itself. The point 
 from which these 
 rays come is called the " far-point " (Fig. XX., /is 
 the far-point, c its image upon the retina). 
 
 It is well known that a concave lens (Fig. XXI.) can 
 
 convert parallel incident rays of light into divergent rays 
 
 in such wise that they appear to come from a point (a) 
 
 FIG. XXI. in front of the lens. 
 
 If this point from 
 which the rays ap- 
 parently diverge is 
 distant i meter in 
 front of the concave lens, we call the lens ro 
 Dioptric (or ! /4o according to the old inch measure- 
 ment) ; if the point is 25 centimeters (or 1 /4m) distant, 
 the lens is -- 4*oZ? (or a /i by the old inch measurement). 
 The sign stands for 'concave.' 
 
42 CHAPTER VII. 
 
 The weakest concave glass, then, through which the eye 
 can clearly see distant objects, is the measure of the 
 degree of the eye's myopia. 
 
 For instance, if I am obliged to use a glass \D 
 (=1/40 by the old measurement) in order to have Vi, 
 my degree of short sight (M) = i *o (or ^o) ; while if I 
 must use 4/?, my M = 4-0 or Vio)- For these concave 
 
 FIG. XXII. 
 
 glasses have the effect of making parallel rays, or rays 
 from infinite distance, appear to come from a point 
 situated at that distance up to which the short-sighted 
 eye can see clearly, i.e., from the far-point of the eye 
 (Fig. XXII. a). 
 
 This far-point of a short-sighted eye can be determined 
 directly by measurement ; the determination is never 
 possible in cases of hyperopia. We have simply to test 
 the short-sighted eye by means of very small print, the 
 so-called ' diamond ' type, and find the most distant 
 point at which this print can be easily read. If, for 
 example, the limit is 25 centimeters, a glass of x /4 of 
 a meter negative focal length, in other words concave 
 4, or 4*0 D, will improve the sight for distant objects. 
 
 But, for this reading test, the eye must be in absolute 
 repose without any use of accommodation, or else the 
 far-point will be placed too near the eye, and a too 
 high degree of M will be inferred ; this mistake can of 
 course be obviated by the use of atropine. 
 
 The division of M into slight, medium, and high 
 degrees is altogether arbitrary. Generally, however, 
 degrees of short sight are called slight if below Mz, 
 medium if between MS and M$ t and high if above Mft. 
 
MYOPIA (SHORT SIGHT). 43 
 
 Von Arlt, in 1839, was the first to demonstrate an- 
 atomically that the lengthened axis was the structural 
 cause of short sight. That part of the eye which is 
 near the back pole is extended. In the normal eye 
 the axis is from 22 to 23 mm. in length. In advanced 
 stages of myopia the length has been found to be 27, 
 30, 33 mm., and in one instance Bonders found it even 
 37 mm. (In this last case the patient's far-point 
 was only i 3 /io inches in front of the eye). The short- 
 sighted eyeball is therefore somewhat egg-shaped. The 
 sclera and choroid, become more and more thin and 
 transparent towards the back pole ; the choroid, indeed, 
 near the optic nerve becomes a thin, colourless membrane 
 insufficiently nourished, in a condition of atrophy ; its 
 pigment here is altogether absent or is accumulated in 
 abnormal quantities round the margin of the atrophic 
 parts. The retina is expanded and its vessels are 
 stretched. Beside the optic nerve we often find the so- 
 called Staphyloma posticum, which is a bulging out of the 
 coating of the eyeball ; this is accompanied by a re- 
 markable alteration in the dividing canal of the optic 
 nerve, as shewn in Fig. XXIV., from a drawing by 
 Bonders. For the sake of comparison the normal state 
 of the canal is represented in Fig. XXIII. from Klein's 
 Augenheilkunde (Compare Chapter I.). 
 
 The outer sheath of 
 
 FIG, XXIII. the optic nerve a in a 
 
 short-sighted eye sep- 
 sc arates from the nerve 
 near the sclera and 
 goes towards a ; while 
 the inner sheath b 
 closely surrounds the 
 nerve and at ti 
 cair passes out into the 
 
 (From Klein? s Auzcnlieilkunde.) SClera. 1 HUS the 
 
44 
 
 CHAPTER VII. 
 
 FIG. XXIV. 
 
 (From Danders' Refractionsanomalien.) 
 
 thin fasciculus a b' bounds the loosely woven cellular 
 tissue in the dividing canal 
 c' t which is here extremely 
 wide, towards the front and 
 so is obviously very much 
 extended. This thin fasci- 
 culus of sclera a b' is 
 covered in front by the com- 
 pletely worn out atrophic 
 and pigmentless choroid (d l ). 
 
 In the higher degrees of 
 myopia, even the vitreous 
 body is liquefied, especially towards the back, and is 
 filled with flocculi which float about in it. According to 
 Ivanoff, the accommodation muscle of short-sighted eyes 
 has the linear fibres much more developed than the 
 circular. 
 
 Outwardly, there is nothing abnormal in the appearance 
 of a short-sighted eye, except that in very extreme cases 
 a certain stare of the elongated eyeball is now and then 
 noticeable. Apart from this, FlG xxv 
 
 it is only by means of 
 the ophthalmoscope that the 
 diagnosis of M, and even of 
 its degree, can be made with Jj 
 certainty, so that the oculist Jjj 
 is quite independent of all jjj 
 subjective data on the part I 
 of the patient. 
 
 In testing with the oph- 
 thalmoscope there is a pheno- 
 menon of the highest import- 
 ance which constantly occurs 
 in a very short - sighted 
 eye, and which is doubtless very closely connected 
 with M. It is this. The observer sees with the 
 
 Sehnerv " optic nerve" 
 
MYOPIA (SHORT SIGHT).' 45 
 
 ophthalmoscope a figure, usually crescent-shaped and white, 
 at the outer side of the optic nerve. (Fig. XXV. represents 
 the normal appearance of the back-ground of the eye, 
 and Fig. XXVI., after Bonders, represents the same 
 back-ground in a short-sighted eye.) This crescent- 
 shaped figure (C) is produced by that atrophy of the 
 FIG. XXVI. choroid which was also 
 
 anatomically demonstrated, 
 and which appears with 
 
 ' 
 
 the ophthalmoscope as a 
 Hi, white space, because near 
 jj| the optic nerve the white 
 sclera is distinctly seen 
 through the atrophic pig- 
 mentless choroid. 
 
 The crescent - shaped 
 figure may vary greatly 
 in size, the crescent some- 
 
 (From Danders' Refractionsanomalien.) tittlCS being VCry narrOW, 
 
 and sometimes having a breadth equal to a quarter, or 
 even exceeding a half, of the diameter of the optic 
 nerve. It is generally found on the outer side of the 
 nerve, but occasionally above, below, or within it, or in 
 high degrees of M it lies in a circle round the nerve. 
 Sometimes a dark band of pigment bounds it from the 
 healthy part of the choroid, and sometimes the transition 
 from the crescent to the choroid is ill-defined. It is 
 not yet established whether this atrophy is really preceded 
 by inflammation of the choroid (Sclerotico chorioditis 
 posterior); but in some cases a bright red colour is 
 observed at this place in the beginning of the process, 
 and a slight redness is occasionally seen at the margin 
 of the crescent-shaped figure. 
 
 In the higher degrees of myopia isolated atrophy is 
 found in other parts of the choroid, of course the danger 
 is very great when the atrophy extends outward and 
 
46 CHAPTER VII, 
 
 approaches the yellow spot, for the slightest participation 
 of the posterior coats of the retina at the yellow spot 
 would most seriously affect the central sight. Sometimes, 
 indeed, an actual bulging out of the back of the eyeball 
 is perceived with the ophthalmoscope. 
 
 Even in the vitreous body when there is a high 
 degree of short sight, the ophthalmoscope often reveals 
 larger and smaller obscurations and flocculi. In the 
 highest degrees of short sight we see actual inflammation 
 of the retina and choroid y haemorrhages in the retina and 
 detachment of the retina. 
 
 Short sight is almost always accompanied by atrophy 
 of the choroid, which increases, as has been proved by 
 experience, with the increase of short sight. 
 
 As a short-sighted person can see only near objects 
 clearly, while distant ones present to him circles of 
 diffusion in place of distinct images, he is (if without 
 spectacles), subject to no little inconvenience, even when 
 in a room. Out of doors his sufferings are far worse. 
 He generally tries to help himself by an unlovely facial 
 contortion, half-closing his eyelids, by which means he 
 to some extent covers the pupil of his eye, and so 
 renders the circles of diffusion smaller and less con- 
 fusing. It is this blinking (muein in Greek) that has 
 given the name Myopia to his malady. Many short- 
 sighted people have accustomed themselves by practice 
 to disentangle, or, as Bonders says, to " work away " 
 their circles of diffusion, so that they manage surpris- 
 ingly well in spite of the confused picture on the retina; 
 while on the other hand those who have accustomed 
 themselves to their spectacles are often painfully at a 
 loss when their spectacles are not at hand. 
 
 The myope's acuity of vision does not usually become 
 less except in the higher degrees of myopia; when, 
 with the outstretching of the back pole of the eyeball, 
 the optic cells are drawn further from each other. 
 
MYOPIA (SHORT SIGHT). 47 
 
 In looking at near objects we not only exert the 
 accommodation muscle, but we turn both eyes inwards 
 towards the. nose by means of the musculi recti interni. 
 In this action the eyes converge. Now in the case of 
 people with normal or emmetropic sight there is a 
 proper joint action of convergence and accommodation, 
 while in the case of short-sighted people the accommoda- 
 tion is spared, because the eyes already see objects at a 
 certain short distance without any aid from accommodation; 
 while the convergence muscles are made to do more than 
 their due share of work ; the internal recti are con- 
 tinually called into action to turn the eyeball inwards. 
 This over-fatigues them and makes them finally incapable 
 of producing the desired effect ; there is insufficiency of 
 the internal recti. If they only fail when required to 
 make an unusual exertion, we say there is a relative 
 insufficiency of these muscles. This muscular weakness 
 can be easily demonstrated by covering one eye of the 
 patient with the hand and making him look with the 
 other eye at a finger held near him, midway between 
 his eyes : then, if the eye is suddenly uncovered by the 
 withdrawal of the hand, the greater strength of the 
 outer muscle will at once be shewn by the eyeball's 
 being turned outwards towards the temple, instead of 
 inwards towards the nose like the eye which was left 
 uncovered. 
 
 But this relative insufficiency gradually developes into 
 absolute insufficiency. A feeling of weariness, over-strain and 
 pressure sets in, to which particularly the name muscular 
 asthenopia (weak sight occasioned by loss of muscular 
 power) has been given by Von Grafe. This lack of 
 endurance in vision, produced by fatiguing the convergence 
 muscles, makes itself painfully felt as a hindrance to 
 work. Everything seems confused to the short-sighted 
 person because he sees double, and that in a peculiar 
 manner. In most cases the double sight is disguised 
 
4$ CHAPTER VII. 
 
 by the letters' appearing to run one into another. (The 
 degree of weakness of the internal recti can be accurately 
 measured by what are called prismatic glasses). Sometimes 
 the patient instinctively tries to relieve himself by only 
 looking with one eye, either closing the other or, when 
 once accustomed to use only one eye, by turning the 
 other outwards. And thus the muscular insufficiency leads 
 to an actual outward squint, at first only periodic, con- 
 fined to those times when the sight is directed to near 
 objects, but by-and-by permanent, especially in the higher 
 degrees of myopia. 
 
 Another disagreeable accompaniment of short-sight is 
 known as mouches volantes, i.e., minute shadowy figures, 
 specks and chains, like flying gnats or other small 
 insects. These figures are the shadows of extremely 
 fine obscurations in the vitreous body which short-sighted 
 people perceive more readily on their retina than 
 emmetropic people. In themselves these specks are not 
 at all dangerous, but they are often very troublesome 
 as a hindrance to work ; and many persons have become 
 quite hypochondriacal from the constant presence of these 
 shadowy flying figures whose dance is especially per- 
 ceptible on white paper. In the higher degrees of 
 myopia the eye is conscious of large shadows and spots 
 which correspond to larger obscurations in the vitreous 
 body, and are attended with serious danger. 
 
 There are two kinds of myopia to be distinguished, 
 the stationary and the progressive. In the former the 
 shortness of sight remains unchanged, and, in the slighter 
 degrees, it leads to no worse results than a certain 
 awkwardness, and a limitation of the choice of a calling. 
 In the 4Oth year of life, indeed, at which period the 
 power of accommodation is decreasing, this slight degree 
 ot short-sightedness sometimes appears to grow less, a 
 phenomenon which may be explained by several reasons. 
 On the one hand, the lens at this age becomes rather 
 
MYOPIA (SHORT SIGHT). 49 
 
 flatter, so that rays coming from a great distance are 
 focussed upon the retina ; on the other hand, as the 
 pupil at this age is always narrower, the circles of- 
 diffusion which fall upon the retina are smaller, so that 
 the retinal picture is less indistinct. Observation of 
 these cases of apparent diminution of M in old age has 
 often led to a notion utterly false, but very difficult to 
 escape from, that short-sighted eyes are the best ! Such 
 cases, however, according to the unanimous testimony of 
 oculists, occur unfortunately very seldom. 
 
 Wholly different is the case of progressive short sight, 
 the mischievous career of which has been most strikingly 
 depicted as follows by the excellent Dutch oculist 
 Bonders : " When the elongation of the eye has 
 reached a certain amount, the membranes become so 
 thin, and their power of resistance is so weakened, that 
 it is no longer possible for the elongation to remain 
 stationary ; while the pressure inside the myopic eye is 
 generally somewhat increased. The progressive elongation 
 and the progressive short sight advance together and this 
 advance is an actual disease. I maintain, then, without 
 hesitation, that a short-sighted eye is a diseased eye. High 
 degrees of short sight have far less prospect of remaining 
 stationary than slight degrees ; they increase even at an 
 advanced period of life. In youth almost every kind 
 of myopia is progressive, and its advance is often 
 accompanied with symptoms of irritation, This age is 
 the critical period for the short-sighted eye ; if during 
 youth the defect does not greatly increase, it may become 
 stationary ; but, if it once developes into a higher degree, 
 it is difficult to put limits to its further advance. // is, 
 then, in youth that injurious exciting influences must be 
 most anxiously guarded against. I cannot lay too much 
 stress upon this point. Progressive short sight is in every 
 case ominous of evil for the future. For, if it remains 
 progressive, the eye soon developes painful symptoms 
 
50 CHAPTER VII. 
 
 and becomes less equal to its work ; and not unfrequentty 
 at the . age of 50 or 60, if not much earlier, the power 
 of sight, either from detachment of the retina, or from 
 hcemorrhage or, lastly, from atrophy and degeneration 
 of the yellow spot, is irrecoverably lost"* 
 
 Every experienced oculist will unreservedly and entirely 
 confirm this opinion of Bonders. 
 
 For the wider the spread of the atrophy of. the 
 choroid at the posterior pole, the nearer it approaches 
 to the yellow spot, the point at which we see most 
 clearly ; and, when once that is attacked by the disease, 
 the central sight is extinguished. Not less dangerous 
 is the detachment of the retina from which so many 
 highly myopic people suffer. This is a disease in which 
 a certain humour is developed between the choroid and 
 the retina. Detachment of the retina is the last step 
 to incurable blindness for, although in very recent 
 operations the attempt to draw off the fluid from behind 
 the retina has now and then been successful, the result 
 has been permanent only in an extremely small number 
 of cases, and the eye, even in those cases, has never 
 been fit for work again. 
 
 As short sight is caused by a lengthening of the axis 
 of the eye, it is unhappily incurable, and here also 
 another passage from Bonders holds good : " The cure 
 of short sight belongs to the pia desideria ; the more 
 accurate and complete our knowledge of the cause becomes, 
 the more futile appears every hope of finding a remedy, 
 even in the future." 
 
 This being so, how earnestly should our attention be 
 directed to the origin, the etiology of myopia, so that 
 we may at the outset prevent the development of the 
 disease or at least arrest, so far as possible, its further 
 progress. We are the more bound to do this because 
 the tendency to short-sightedness is most probably 
 
 * Anomalien der Refraction und Accommodation, p. 289. 
 
MYOPIA (SHORT SIGHT). 51 
 
 hereditary ; and therefore by neglecting an intelligent 
 prophylactic method we wrong not only the present but 
 also future generations. 
 
 There has been much discussion as to the ultimate cause 
 of that lengthening of the axis to which all the evil con- 
 sequences above described are due, but, up to the 
 present time, the matter has not been fully cleared up. 
 A number of medical men believe that the primary 
 cause is a congenital attenuation of the posterior part 
 of the sclera, and that this attenuation is hereditary ; 
 but this theory is opposed by the majority of oculists, 
 for they have actually seen, times without number, 
 children become short-sighted whose parents had perfectly 
 normal sight, and who in the first ten years of their 
 life did not show the slightest tendency to myopia. 
 But all authors, whether adherents or opponents of the 
 theory that short sight is congenital, agree that there is 
 a predisposing influence which greatly favours the 
 development of the disease, and that this influence is 
 the continual looking at near objects, especially under an 
 insufficient light. 
 
 In looking at near objects the accommodation is strongly 
 exerted, the choroid strained, the convergence forced and 
 the head bent forivard. 
 
 The continued exertion of the accommodation muscle 
 in reading, writing and hand-work leads to a kind of 
 convulsive contraction (accommodation cramp or spasm), 
 which often continues even when the eye has looked for 
 some time at distant objects. This contraction forces the 
 lens to assume a more convex form ; and so the images 
 which it gives of distant objects are focussed in front of, 
 instead of upon, the retina. There arises in this way an 
 apparent myopia called lens-myopia, to distinguish it from 
 the axis-myopia we have described above. If the accom- 
 modation muscle obtains sufficient rest and the lens 
 becomes flat again, this kind of myopia may disappear 
 
52 CHAPTER VII. 
 
 and emmetropia return. But if the accommodation 
 muscle has not time to recover itself and the lens 
 accordingly cannot properly relax, the transient lens- 
 myopia gradually passes into the chronic axis-myopia. 
 
 The influence of spasm of the accommodation muscle 
 upon the lens is often manifested in examinations of 
 the eye, when the muscle has been paralysed by atropine. 
 A scholar, for instance, appears to need for distant 
 objects a pair of spectacles $D ; but when, by dropping 
 atropine into his eye, the accommodation has been 
 suspended, it is found that he can see distant objects 
 quite well without any spectacles at all, or that he only 
 needs a glass iD. In the former case the accom- 
 modation-spasm has simulated a myopia 3 while he is 
 really emmetropic, in the latter case his myopia has 
 appeared to be greater by zD than it really is. I 
 have observed very many such cases of accommodation- 
 spasm and lens-myopia. It is just this spasm that 
 often makes it hard work to determine M accurately by 
 reading tests or by glasses, the ophthalmoscope often 
 shewing a much lower degree of M than the reading 
 test. 
 
 The continuous over-straining of the accommodation 
 muscle has also the effect of stretching and pulling the 
 choroid and so of inducing, near the optic nerve, that 
 choroidal attenuation and atrophy which, earlier in this 
 chapter, we have described in detail as a crescent. 
 
 The convergence of the' eyes, which is a necessity in 
 looking at near objects, requires a constantly heightened 
 activity of the internal recti ; while this convergence 
 (and very probably the accommodation also), increases 
 the pressure in the vitreous body, and thus helps on 
 the expansion of the posterior coats of the eye. The 
 muscular activity causes also a tension of the sclera at 
 the outer side of the optic nerve in consequence of 
 which the alterations, described above, in the dividing 
 
MYOPIA (SHORT SIGHT). 53 
 
 canal take place ; the sclera, accordingly, is gradually 
 attenuated and becomes more easy to stretch at the 
 back. 
 
 Lastly the continuous stooping of the head, necessitated 
 by constant looking at near objects, produces a con- 
 gestion in the veins which carry off the blood from the 
 eye. Hence arise irritating conditions and over distensions 
 with blood in the back part of the eyeball, and these 
 may bring on a yielding of the choroid and the sclera. 
 
 It is true that a high degree of myopia has been 
 found in individuals who have never tried their eyes 
 by minute near work ; but such cases are the rarest 
 exceptions and are generally influenced by hereditary 
 tendencies. 
 
 The fact that short sight is not universal among those 
 who have constant near work with a bad light may 
 partly be explained thus. Many persons who, in spite 
 of near work, have been found emmetropic, were once 
 hyperopic, so that the elongation of the eye's axis has 
 been needed in order to make the sight normal. 
 
 This point, which is still a matter of dispute, need 
 receive no further notice here ; for all oculists agree 
 that protracted near work with a bad light is one of 
 the circumstances most favourable to the origin and 
 development of short sight. 
 
 That the statement thus admitted rests on a long experi- 
 ence, gained by means of statistics, will be shewn in 
 the following chapters. 
 
54 CHAPTER VIII. 
 
 CHAPTER EIGHTH. 
 
 REFRACTION OF THE EYES OF SCHOOL CHILDREN. * 
 
 The earliest notice of the sight of school children is 
 found in a work by James Ware 1 , published in 1812. 
 He states that in a military school at Chelsea only 3 
 children out of 1,300 complained of short sight ; on the 
 other hand out of 127 students at Oxford, in the year 
 1803, no fewer than 32 used eye-glasses or spectacles. 
 "It is possible," adds Ware, "that several were led to 
 use glasses just because it was the fashion ; but the 
 number of these is certainly inconsiderable in comparison 
 with those who really saw better with glasses." 
 
 Between 1839 and 1850 we learn from Schurmayer 2 , 
 that in the Grand Duchy of Baden, inquiries were made 
 in the schools, with the result that, in the 15 
 educational establishments, 392 scholars out of 2,172 were 
 short-sighted ; that is, nearly one-fifth of the whole 
 number. Among the 930 scholars in the higher 
 municipal schools 46 (or about 1 /2o) were M. In the 
 fifth and sixth classes (the highest) of the Grammar 
 Schools from */ 4 to Y 2 f tne scholars were M. 
 
 In 1848, Szokalsky 3 instituted inquiries in Paris and 
 found that in the College Charlemagne i scholar in 9 
 was M, and in the College Louis le Grand i in 7. 
 " This result was the more surprising, because among 
 the 6,300 children of the Parisian Elementary Schools 
 
 * The figures near the names of authors refer to the list of publications at the 
 end of this work. 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 55 
 
 in the 6th and 7th arrondissement, there was not a 
 single short-sighted child to be found." (??) Szokalsky 
 already publishes tables to shew the gradual advance of 
 M in the different classes. From the quarto, to the 
 prima in the College Charlemagne the number of M"s 
 rose in the proportion i : 21, 14, u, 8, 9 ; and in the 
 College Louis le Grand, in the proportion i: n, 12, 
 7, 4. The latter college seems to have been examined 
 by Szokalsky himself, but this is not quite certain. 
 No information is given as to the degree of short sight. 
 
 Compared with these early statistics, which relate to 
 the complaints of the scholars, or to hearsay, or to very 
 inexact testings, the observations of E. von Jager 4 , 
 published in Vienna in 1861, deserve special mention 
 as breaking fresh ground. Von Jager was the first to 
 examine the children for himself with the ophthalmoscope. 
 He found in an orphanage, among boys from 7 to 14 
 years old, 33 per cent, with normal sight, 55 M and 
 12 H. On the other hand, in a private school, among 
 the children from 9 to 16 years old, he found 18 per 
 cent, normal, 80 M and 2 H. He also noticed the 
 different degrees of short sight, although he did not 
 tabulate these according to classes. His materials, too, 
 as he himself says, were too scanty for a general 
 conclusion. 
 
 In the summer of 1865, Professor Rtite 5 personally 
 examined the eyes of 213 children sent to him by the 
 teachers of 2 National Schools, in Leipzig, as suffering 
 in the eyes ; the whole number of scholars in the two 
 schools was 2,514. Of the 213, he found that 107 
 had inflammations of the eyelids, the conjunctiva and the 
 cornea ; 48 had short sight and 55 hyperopia. The 
 number of ATs thus varied from 2 to 3 per cent. 
 Of course there were numerous cases of lower degrees 
 of M of which Rtite took no notice. 
 
 As in the earlier investigations before Jager no regard 
 
56 CHAPTER VIII. 
 
 had been paid to the difference between H and M, 
 and as, afterwards, the number of scholars examined was 
 in no case large enough to exclude accidental error, and 
 the scholars were moreover not examined by medical 
 men personally ; and as neither the degrees of short 
 sight with reference to the different classes, nor the 
 locality, with the school desks, had been taken into 
 account, I 6 undertook in the year 1865-1866 the 
 examination of 10,060 school children as follows : I 
 first held a preliminary examination with test-types of all 
 the scholars in the department, and then a special 
 examination with the ophthalmoscope of those children 
 who could not read the test-types at the normal distance. 
 Besides this, I measured the height of every scholar in 
 the 1 66 departments and all the dimensions of the 
 desks that I found, and I added a table of the lighting 
 of the schools (see Chapter XIII.). For each scholar 
 I recorded the age, the number of years he had been 
 at school, the result of the reading test, the spectacles 
 finally fixed on, and the result of the ophthalmoscope. 
 
 In this manner I examined 5 village schools (in 
 Langenbielau, in the district of Reichenbach in Silesia), 
 20 town elementary schools. 2 middle schools, 2 higher 
 schools for girls, 2 real schools, and 2 gymnasia in 
 Breslau ; altogether 10,060 children, that is 1,486 village 
 children and 8,574 town children. I found that 5*2 
 per cent, of the village children, and 19*2 per cent, of 
 the town children, had defective sight. Altogether there 
 were 17*1 per cent, or nearly one-fifth of the total 
 number, ametropic. This percentage would doubtless 
 have been considerably greater if I had not excluded 
 from my tables, as practically of too little account, every 
 case of M < I /$G, or about < \D. 
 
 I found 83 per cent. E (with normal sight), 13 per 
 cent, with defective refraction (10 per cent, of them 
 being M), and 4 per cent, suffering from various other 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 57 
 
 diseases of the eye. The frequency of myopia is shewn 
 by the following table : 
 
 I noted in 5 village schools ... ... 1*4 per cent. M. 
 
 20 elementary schools ... 67 
 2 higher schools for girls ... 77 
 
 2 middle schools 10'3 
 
 2 real schools 197 
 
 2 gymnasia 26'2 ,, 
 
 that is, out of 10,060 children, 1,004^ = 9*9 per cent. 
 
 It was evident from this, (i) that in village schools 
 the percentage of short sight is very low, while in the 
 town schools the number of short-sighted scholars constantly 
 increases with the grade of the school, from the lowest 
 grade to the highest : so that the number of short-sighted 
 children is in direct relation to the length of time during 
 which the children's eyes are worked. 
 
 In the town elementary schools there were 4 or 5 
 times more Ms found than in the village schools. In 
 the latter the number of Ikfs varies generally from 0*8 
 to 3-2 per cent., while in the 20 elementary schools it 
 varies from 1*8 to 15*1 per cent. In the various real 
 schools and gymnasia the difference was only 2 4 per 
 cent. 
 
 It was evident (2) that in every school the number of 
 short-sighted children increased from class to class. On an 
 average the number of M's in the third, second, and 
 first classes of the village schools was 1*4, 1*5 and 
 2*6 per cent. On the other hand the average result in 
 the same classes of the 20 elementary schools was 3*5, 
 9 "8 and 9*8 per cent. 
 
 In the real schools the M percentages from the 
 sexta to the prima were 9, 167, 19*2, 25*1, 26*4, 44, 
 in the gymnasia 12-5, 18-2, 237, 31, 41*3, 55-8. That 
 is, more than half of tJie highest class are short-sighted. 
 
 Of course there were here and there slight exceptions 
 to this increase, a lower percentage being sometimes 
 found, for instance, in the first class than in the second, 
 
58 CHAPTER VIII. 
 
 but this was chiefly owing to the fact that usually only 
 a small number of scholars were present in the highest 
 classes, so that a single case of M gives a very different 
 percentage in them from what it gives in the fuller 
 lower classes. But with larger numbers and on an 
 average, the increase constantly shewed itself. 
 
 In the village and elementary schools there was found 
 no essential difference between the sexes ; but the large 
 contingent of M 1 s found in the gymnasia and real 
 schools made the number of M boys in the 10,060 
 children twice as many as the number of M girls. 
 
 The M number was found to increase not only 
 with the rank of the class but with the number of 
 years spent at school. I found no M in the village 
 schools among children who had only been half a year 
 at school ; while of those who were in their fourth or 
 fifth year the M number was 1*6 per cent, for village 
 school children, 8*2 per cent, for town elementary 
 scholars, 1 1 '9 per cent, for middle school children, and 
 14*5 per cent, for scholars in real schools and gymnasia. 
 If I added together, respectively, the first 4 years at 
 school, the second 4, and the last 6 years (corresponding 
 nearly to the 7th-2Oth years of life), I found 4*5, 9-6, 
 and 2 8 '6 per cent. M. 
 
 There appeared (3) unmistakeably in the 166 classes 
 of the 33 schools an increase in the degree of M from 
 class to class in all the schools. I selected at that time 
 6 stages of M. First M 1 /s5 to M 1 /^ (about i D to 
 1-5^); 2nd, ^/!/23 to Vie (= 175 2-25); 3rd, M^ 
 to 1/12 (2-5 3); 4th, Mi/n to 1/8 (3-25 4); 5th, Mi/7 
 (Ms), and 6th, M l / 6 (M6). The 1,004 J/'s were 
 distributed over these stages as follows : 466, 303, 
 150, 76, 6, 3. I never found a higher stage than M l ji 
 in any village school. On the whole, nearly half of 
 the M's were weaker than M l j^. M 1 /? and a / 6 were 
 only found in gymnasia and real schools. Among boys 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 59 
 
 the higher stages of M were more frequent than among 
 girls. (For details the reader is referred to the essay 
 from which I am quoting). 
 
 The degree of M advances also with the age of the 
 scholar ; the higher degrees, however, are more frequently 
 found in the first four years of school life than in the 
 7th-ioth years of life. 
 
 To find the average degree of short sight in any class, 
 I added up the degree-numbers of myopia found in the 
 class, and divided by the number of myopes. The mean 
 of these average degrees for various classes gave the 
 average degree of myopia in the school ; and the mean 
 of these last averages for various schools of the same 
 sort, gave the average degree of M for that sort of 
 school. 
 
 Thus I found the average degree of M in 5 village 
 schools to be = ^, in 20 elementary schools = -~> 
 in 2 middle schools = ^p^, in 2 real schools = -^ and 
 in 2 gymnasia = -^. The average degree of all M's 
 was M = -~^. So that the average degree of M rises 
 constantly from the village schools to the gymnasia. 
 
 That it also rises from the lowest class to the highest 
 is evident from the following table which gives (in the 
 old inch-measurement) the average far-points from the 
 6th to the ist class: 
 
 In real schools : 237, 20, 19*8, 19*1, iS'S, 167" 
 In gymnasia : 22*4, 20*6, 18*9, 18, 157, 17-1" 
 
 The average degree of M differs but slightly for the 
 two sexes. I never found a higher degree than M !/6, 
 except when accompanied by complicating eye disorder. 
 
 Among the 1,004 M there were 200 cases of staphyloma 
 posticum. In the village schools, but only in the highest 
 class, the cases amounted to 0*2 per cent, of the total 
 number of scholars ; in the elementary schools they 
 increased to 0*5 per cent, in the higher girls' schools 
 
60 CHAPTER VIII. 
 
 ^ were 0*3 per cent, of the total number of girls, 
 and 4*6 per cent, of the short-sighted ones ; in the 
 middle schools they were i -4 per cent, of the total 
 number, and 13*6 per cent, of the short-sighted scholars; 
 in the real schools 7*1 per cent, of the total number, 
 and 36 per cent, of the short-sighted scholars, and in 
 the gymnasia 6*9 per cent, of the total number, and 
 26 per cent, of the short-sighted scholars. 
 
 The number of these cases of staphyloma increased 
 with the age of the myopes. The higher the degree of 
 M the more frequently it was accompanied with staphyloma 
 posticum, so that the percentages of staphyloma in the 
 
 6 stages of M mentioned above were as 3 : 17: 48 : 
 65 : 71 : 100. It was quite an exception to find slight 
 degrees of M attended with staphyloma, or high degrees 
 of M without staphyloma. 
 
 Hyperopia I found in 239 children (or 2 '3 per cent.) 
 and as much in girls as in boys. For one case of H 
 there were always more than 4 cases of M. Of course 
 this calculation is based upon manifest H alone ; in 
 this H there was no important increase or decrease 
 from school-year to school-year or from school to school. 
 The degree of // varied from /n/eo to ff l /8', in the 
 majority of cases from // x /4o to H x /2o ; there were only 
 
 7 cases of H > 1 /i2- The average degree in the village 
 schools was l /^, in the elementary schools 1 /s 2l in the 
 higher girls' schools 1 /26, in the middle schools ^37, in 
 the real schools 1 /28, and in the gymnasia */24- The 
 average degree of all the cases of H was 1 /so. Only 
 9 hyperopes wore convex glasses. Out of the 239 H 
 158 had an inward squint (strabismus convergens) = 66 
 per cent, of H and 1*5 per cent, of the total number 
 of children. Of the H boys 67 per cent, and of the 
 H girls, 63 per cent., squinted ; in the higher girls' 
 schools 3-9 per cent., in the higher boys' schools only 
 IT per cent. The squint was in the right eye in 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 6 1 
 
 104 cases, in the left in 30; in 23 cases both^eyes 
 squinted by turns. In 44 children the squint was 
 periodic, in 114 it was continual. In 80 per cent 
 of those scholars who squinted I found medium degrees 
 of H ( I /Q 1 /2o). The V of the squinters varied from 
 9 /io to l / m . 
 
 In 23 children I noted astigmatismus regularis. Only 
 one of them wore cylindrical glasses. 
 
 The number with some eye-disease amounted to 396 = 4 
 per cent. These children furnished 490 cases of eye-disease, 
 of which only 2 1 1 were cases of spots upon the cornea 
 (maculae corneae). The other cases were of scrofulous 
 inflammation of the cornea in children of the poorest 
 classes attending elementary schools. 
 
 The wish expressed by me, on the publication of these 
 results in the year 1867, that similar investigations should 
 be set on foot in other places, has been amply fulfilled. 
 A great mass of statistics now exists, collected by 
 competent observers in other towns, statistics which have 
 the advantage, in the first place, of taking into account 
 the degrees of M < 1 /36 (or < i Z?), practically insigni- 
 ficant, but theoretically most important. The percentages 
 of M in the following tables are therefore generally 
 much higher than mine. 
 
 Besides this, some of these oculists have examined 
 each eye separately, instead of both together ; other 
 writers have tested all the children, even those whose 
 sight was apparently normal, with the ophthalmoscope. 
 
 It would, however, lead us too far, to give here all 
 the details of these statistics, which relate to the eyes 
 of more than 50,000 school children ; especially as they 
 collectively confirm the principal results, above described, 
 of my own examinations, and differ, too, but slightly 
 from my results as to the manner in which they have 
 been obtained. Moreover many of these researches are 
 only of local interest. On the other hand, several new 
 
62 CHAPTER VIII. 
 
 points of view for which we are indebted to the more 
 recent researches, require to be dwelt on somewhat 
 fully. But before attempting this, I must be allowed to 
 insert the following tables, which will give an idea of 
 the immense activity of writers labouring in this depart- 
 ment of school hygiene. 
 
 (The sources whence the numbers in these tables are 
 derived will be found in the literary catalogue at the 
 end of this book). 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 
 
 TABLE No. I. 
 PERCENTAGE OF SHORT-SIGHTED SCHOOL CHILDREN. 
 
 Year. 
 
 Examiner. 
 
 Locality. 
 
 School. 
 
 Number 
 of 
 children 
 exam- 
 ined. 
 
 Per- 
 cent- 
 age of 
 short 
 sight. 
 
 1861 
 
 E. von Jager 4 
 
 Vienna. 
 
 Orphanage for Boys 
 
 50 
 
 55 
 
 1 QRK 
 
 }" 
 
 
 Private School 
 
 50 
 
 80 
 
 1 OU<J 
 
 Ifififi 
 
 H. Cohn 6 . 
 
 Breslau 
 
 33 Schools: . . , ! 10060: 
 
 10 
 
 A OU vj 
 
 
 
 5 Village Schools . 
 
 1486 
 
 1 
 
 
 
 
 20 Town Elementary 
 
 
 
 
 
 
 Schools 
 
 4978 
 
 7 
 
 
 
 
 2 Middle Schools . 
 
 426 
 
 8 
 
 
 
 
 2 Higher Girls' Schools . 
 
 834 
 
 10 
 
 
 
 
 Holy Ghost Real School 
 
 502 
 
 18 
 
 
 
 
 Zwinger Real School 
 
 639 
 
 21 
 
 
 
 
 Elizabeth Gymnasium . 
 
 552 
 
 24 
 
 
 
 
 Magdalen Gymnasium . 
 
 663 
 
 23 
 
 1868 
 
 Thilenius 7 . 
 
 Rostock 
 
 Gymnasium . 
 
 314 
 
 31 
 
 1870 
 
 Schultz 8 
 
 Upsala 
 
 Gymnasium . 
 
 431 
 
 37 
 
 1870 
 
 H. Cohn 9 . 
 
 Breslau 
 
 Frederick Gymnasium . 
 
 361 
 
 35 
 
 
 
 
 The same 1 \ years later . 
 
 138 
 
 51 
 
 1871 
 
 Erismann 10 
 
 St. Petersburg 
 
 8 Gymnasia . 
 
 ) 
 
 
 
 
 
 4 German Schools . 
 
 4368: 
 
 30 
 
 
 
 
 1 Girls' Gymnasium 
 
 j 
 
 
 
 \ 
 
 
 Boys' Schools 
 
 3266 
 
 31 
 
 
 
 
 Girls' Schools. 
 
 1092 
 
 27 
 
 
 
 
 Russians 
 
 2534 
 
 34 
 
 
 
 
 Germans 
 
 1834 
 
 24 
 
 
 
 
 Day Pupils . 
 
 397 
 
 35 
 
 
 
 
 Boarders 
 
 918 
 
 42 
 
 1871 
 
 Maklakoff 11 
 
 Moscow 
 
 ? (not indicated in the 
 
 
 
 
 
 
 German reports) . 
 
 759 
 
 33 
 
 1871 
 
 H. Cohn 12 . 
 
 Schreiberhau 
 
 Village School 
 
 240 
 
 1 
 
 1873 
 
 Kriiger * 3 . 
 
 Frankfort on 
 
 
 
 
 
 
 the Main . 
 
 Gymnasium . 
 
 203 
 
 34 
 
 1873 
 
 H.v.Hoffmann 14 
 
 Wiesbaden . 
 
 4 Schools : . 
 
 1227: 
 
 20 
 
 
 
 
 Prepy. and Municipal S. 
 
 568 
 
 20 
 
 
 
 
 Higher Girls' School 
 
 403 
 
 20 
 
 
 
 
 Gymnasium . . .' : 256 
 
 38 
 
 1874 
 
 A. von Reuss 15 . 
 
 Vienna 
 
 Leopoldstadt Gymnasium! 409 
 
 42 
 
 
 
 
 The same one year later . 
 
 211 
 
 52 
 
 1874 
 
 Ott u. Ritzmann x 6 
 
 SchafThausen 
 
 Gymnasium . 
 
 122 
 
 44 
 
 1874 
 
 Ott 17 . 
 
 Schaffhausen 
 
 Real School . 
 
 164 
 
 13 
 
 1874 
 
 Burgl 18 
 
 Munich 
 
 Girls' High School 
 
 179 
 
 49 
 
 1874 
 
 Dor 19 
 
 Berne . 
 
 Cantonal Real School 
 
 143 
 
 35 
 
 
 
 
 Cantonal Classical School 
 
 117 
 
 28 
 
 
 
 
 Town Real School . 
 
 170 
 
 25 
 
 1875 
 
 Conrad 20 . 
 
 Konigsberg . 
 
 3 Gymnasia . 
 
 1518 
 
 22* 
 
 * 32 per cent, by test types found to be M ; 22 by ophthalmoscope. 
 
6 4 
 
 CHAPTER VIII. 
 
 TABLE No. I. (Continued.) 
 
 Year. 
 
 Examiner. 
 
 Locality. 
 
 School. 
 
 Number 
 of 
 children 
 exam- 
 ined. 
 
 Per- 
 cent- 
 age of 
 short 
 sight. 
 
 1875 
 
 Callan 21 . 
 
 New York 
 
 Negro Schools : 
 
 457: 
 
 3 
 
 
 
 
 Primary Department 
 
 ? 
 
 
 
 
 
 
 Grammar Department 
 
 ? 
 
 5 
 
 1876 
 
 Scheiding 2 2 
 
 Erlangen 
 
 Gymnasium . 
 
 175 
 
 55 
 
 1876 
 
 Koppe 23 . 
 
 Dorpat. 
 
 Kindergarten 
 
 31 
 
 
 
 
 
 
 National School 
 
 103 
 
 2 
 
 
 
 
 Preparatory School. 
 
 136 
 
 11 
 
 
 
 
 Gymnasium . 
 
 396 
 
 30 
 
 1876 
 
 Pfluger 24 . 
 
 Lucerne 
 
 Lower School, Boys' 
 
 808 
 
 5 
 
 
 
 
 Lower School, Girls' 
 
 879 
 
 8 
 
 
 
 
 Real School . 
 
 74 
 
 36 
 
 
 
 
 Gymnasium . 
 
 85 
 
 52 
 
 1876 
 
 A. von Reuss 35 . 
 
 Vienna 
 
 Leopoldstadt Gymn'sium, 
 
 
 
 
 
 
 3 examinations . 
 
 252 
 
 50 
 
 
 
 
 National School 
 
 240 
 
 11 
 
 1876 
 
 Loring& Derby 20 
 
 New York . 
 
 Primary School 
 
 205 
 
 7 
 
 
 
 
 District School 
 
 249 
 
 12 
 
 
 
 
 Normal School 
 
 679 
 
 27 
 
 
 
 
 Ch'n of German parents 
 
 ? 
 
 24 
 
 
 
 
 American 
 
 ? 
 
 20 
 
 
 
 
 Irish 
 
 ? 
 
 14 
 
 1877 
 
 Emmert 2T . 
 
 Berne . 
 
 15 Schools: 
 
 2148: 
 
 12 
 
 
 
 
 Lerber Gymnasium 
 
 219 
 
 21 
 
 
 
 
 Burgdorf Gymnasium . 
 
 158 
 
 10 
 
 
 
 
 Solothurn Gymnasium . 
 
 112 
 
 23 
 
 
 
 
 Training College for Tea- 
 
 
 
 
 
 
 chers, Miinchenbuchsee 
 
 113 
 
 8 
 
 
 
 
 New School, Girls', Berne 
 
 292 
 
 15 
 
 
 
 
 Municipal School, Girls', 
 
 
 
 
 
 
 Berne 
 
 239 
 
 15 
 
 
 
 
 Girls' School, Burgdorf . 
 
 89 
 
 6 
 
 
 
 
 Elementary Schl,Burgdorf 
 
 126 
 
 1 
 
 
 
 
 Primary and Secondary 
 
 
 
 
 
 
 School in St. Immer . 
 
 220 
 
 5 
 
 
 
 
 Primary and Secondary 
 
 
 
 
 
 
 School in Locle . 
 
 233 
 
 10 
 
 
 
 
 Primary and Industrial 
 
 
 
 
 
 
 School in Chaux de 
 
 
 
 
 
 
 Fonds 
 
 240 
 
 11 
 
 
 
 
 4 Watchmakers' Schools . 
 
 107 
 
 12 
 
 1877 
 
 Kotelmann 28 
 
 Hamburg 
 
 Johannes Gymnasium . 
 
 413 
 
 38 
 
 
 
 
 Reform. Real School 
 
 232 
 
 26 
 
 
 
 
 Municipal High School . 
 
 310 
 
 25 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 
 
 TABLE No. I. (Continued.) 
 
 Year. 
 
 Examiner. 
 
 Locality. 
 
 School. 
 
 Numbe 
 of 
 children 
 exam-~ 
 ined. 
 
 Per- 
 
 cent- 
 age of 
 short 
 sight. 
 
 1877 
 
 Kotelmann 28 
 
 Hamburg 
 
 Pracht's Private High 
 
 
 
 
 
 
 School, Girls' 
 
 104 
 
 17 
 
 
 
 
 Zimmermann's ditto 
 
 218 
 
 22 
 
 
 
 
 Training School for 
 
 
 
 
 
 
 Mistresses . 
 
 45 
 
 42 
 
 
 
 
 Training School's Nationa 
 
 
 
 
 
 
 School 
 
 296 
 
 12 
 
 
 
 
 Gymnasium inWandsbeck 
 
 283 
 
 19 
 
 1877 
 
 Classen 29 . 
 
 Hamburg 
 
 Johannes Real School . 
 
 402 
 
 41 
 
 1877 
 
 0. Becker 30 
 
 Heidelberg . 
 
 Gymnasium . 
 
 287 
 
 35 
 
 
 
 
 Municipal School . 
 
 261 
 
 13 
 
 1877 
 
 Williams 31 . 
 
 Cincinnati . 
 
 District Schools 
 
 630 
 
 10 
 
 
 
 
 Middle Schools 
 
 210 
 
 14 
 
 
 
 
 High Schools . 
 
 210 
 
 16 
 
 1877 
 
 Agnew 32 
 
 New York . 
 
 New York College . 
 
 579 
 
 39 
 
 
 
 
 Brooklyn Polytechnic In- 
 
 
 
 
 
 
 stitute 
 
 300: 
 
 19 
 
 
 
 
 Academic Department . 
 
 142 
 
 10 
 
 
 
 
 Collegiate Department . 
 
 158 
 
 28 
 
 1877 
 
 H. Derby 33 . 
 
 Boston 
 
 Amherst College . 
 
 1880? 
 
 28 
 
 
 
 
 Harvard 
 
 122 
 
 29 
 
 1878 
 
 Niemann 34 . 
 
 Magdeburg . 
 
 Cathedral Gymnasium . 
 
 325 
 
 48 
 
 
 
 
 Convent School 
 
 388 
 
 44 
 
 1878 
 
 Seggel 35 . 
 
 Munich 
 
 Cadets' Real Gymnasium 
 
 ? 
 
 31 
 
 1878 
 
 Dor 36 . 
 
 Lyon . 
 
 Lyceum : 
 
 1016: 
 
 22 
 
 
 
 
 Day Scholars . 
 
 683 
 
 18 
 
 
 
 
 Day Boarders 
 
 129 
 
 29 
 
 
 
 
 Boarders 
 
 204 
 
 33 
 
 1878 
 
 Reich 37 
 
 Tiflis . 
 
 Four Schools : 
 
 1258: 
 
 29 
 
 
 
 .. 
 
 Classical Gymnasium 
 
 ? 
 
 37 
 
 
 
 
 Girls' Gymnasium . 
 
 ? 
 
 25 
 
 
 
 
 Municipal School . 
 
 ? 
 
 10 
 
 
 
 
 Training Sch. for Teachers 
 
 ? 
 
 12 
 
 
 
 
 Russians in the above 4 
 
 
 30 
 
 
 
 
 Schools 
 
 ? { 
 
 \J O \J 
 
 2 8 
 
 
 
 
 Armenians ditto . 
 
 ? { 
 
 824 
 425 
 
 
 
 
 Georgians ditto 
 
 ? { 
 
 521 
 410 
 
 1878 
 
 Haenel 38 . 
 
 Dresden 
 
 Royal Gymnasium . 
 
 476 
 
 49 
 
 1879 
 
 Just 38 
 
 Zittau . 
 
 Gymnasium . 
 
 194 
 
 48 
 
 
 
 
 Real School . 
 
 293 
 
 40 
 
 1 
 
 
 
 
 
 tie; 
 
 OF THK 
 
 UNIVERL 
 
66 
 
 CHAPTER VIII, 
 
 TABLE No. I. ( Continued. ) 
 
 Year. 
 
 Examiner. 
 
 Locality. 
 
 School. 
 
 Number 
 of 
 children 
 exam- 
 ined. 
 
 Per- 
 cent- 
 age of 
 short 
 sight. 
 
 1879 
 
 Just 39 
 
 Zittau . 
 
 Select Girls' School 
 
 193 
 
 24 
 
 
 
 
 Municipal School, Girls 
 
 202 
 
 14 
 
 
 
 
 Municipal School, Boys 
 
 347 
 
 15 
 
 1879 
 
 Nicati 40 . 
 
 Marseilles 
 
 6 (?) Schools . 
 
 1717 
 
 15 
 
 
 
 
 Boys' Primary School 
 
 ? 
 
 8 
 
 
 
 
 Girls' 
 
 ? 
 
 7 
 
 
 
 
 Jews' Boys' School . 
 
 ? 
 
 15 
 
 
 
 
 Jews' Girls' School . 
 
 ? 
 
 10 
 
 
 
 
 Great Lyceum, Boarding 
 
 
 
 
 
 
 and Day Boarding 
 
 ? 
 
 35 
 
 
 
 
 Small Lyceum ditto 
 
 ? 
 
 22 
 
 
 
 
 Lyceum (externes sur- 
 
 
 
 
 
 
 veille-s) 
 
 ? 
 
 16 
 
 
 
 
 Lyceum (externes libres) 
 
 ? 
 
 62 
 
 1879 
 
 Priestley Smith 41 . 
 
 Birmingham . 
 
 ?(not in German report) . 
 
 1636 
 
 5 
 
 
 
 
 Training College Students 
 
 357 
 
 20 
 
 1880 
 
 Netoliczka 4 2 
 
 Graz . 
 
 Gymnasium . 
 
 653 
 
 35 
 
 
 
 
 Real School . 
 
 278 
 
 33 
 
 
 
 
 Municipal National Schl., 
 
 
 
 
 
 
 Boys' 
 
 2350 
 
 10 
 
 
 
 
 Village School, Boys' 
 
 361 
 
 4- 
 
 
 
 
 Municipal Nat. Sch., Girls' 
 
 2238 
 
 13 
 
 
 
 
 Village School, Girls' 
 
 299 
 
 8 
 
 1880 
 
 Florschiitz 4 s 
 
 Coburg. 
 
 6 Schools in the year 1874: 
 
 2041: 
 
 21 
 
 
 
 
 Municipal Boys' School . 
 
 694 
 
 12 
 
 
 
 
 Municipal Girls' School . 
 
 782 
 
 14 
 
 
 
 
 Gymnasium . 
 
 177 
 
 51 
 
 
 
 
 Real School . 
 
 260 
 
 42 
 
 
 
 
 Alexandrina School 
 
 112 
 
 25 
 
 
 
 
 Training School 
 
 16 
 
 43 
 
 
 
 
 The same 6 schls. in 1 877 : 
 
 2323: 
 
 14 
 
 
 
 
 Municipal Boys' School . 
 
 786 
 
 4 
 
 
 
 
 Municipal Girls' School . 
 
 830 
 
 7 
 
 
 
 
 Gymnasium . 
 
 182 
 
 49 
 
 
 
 
 Real School . 
 
 290 
 
 35 
 
 
 
 
 Alexandrina School 
 
 147 
 
 31 
 
 
 
 
 Training School 
 
 28 
 
 32 
 
 1881 
 
 A. Weber 41 . 
 
 Darmstadt . 
 
 Gymnasium . 
 
 509 
 
 44 
 
 
 
 
 Real School . 
 
 354 
 
 41 
 
 
 
 
 High School, Girls' 
 
 265 
 
 42 
 
 
 
 
 Middle School, Girls' . 
 
 270 
 
 27 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 
 
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68 
 
 CHAPTER VIII. 
 
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REFRACTION OF THE EYES OF SCHOOL CHILDREN. 
 
 69 
 
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CHAPTER Vlll. 
 
 Among the investigations which present new points of 
 view, that of Erismann 10 (1871) demands the first place. 
 He tested in St. Petersburg with Snellen's types 4,368 
 scholars, at 20 feet distance from the types, and found 
 30-2 per cent. M, 26 per cent. E, 43-3 per cent. //, 
 and 5 per cent, amblyopic or weak-sighted. The 
 enormous percentage of hyperopic children was surprising. 
 These were cases of facultative-manifest hyperopia, occurring 
 in scholars who could see distant objects as clearly 
 without convex glasses as with them. Most of the H 
 cases were found in the lowest classes, and their number 
 gradually decreased from the lowest to the highest class 
 In my own examination I had paid but little attention 
 to the number of hyperopic cases, because the absolute 
 percentage of H cannot be ascertained without atropine, 
 which I was not allowed to use, as, of course, neither 
 was Erismann. Nevertheless Erismann rightly conjectured 
 that H is the normal condition of the eye in youth, and 
 that only the minority of cases remain hyperopic in after 
 life, the majority becoming short-sighted after passing 
 through emmetropia or normal sight. 
 
 He supported his hypothesis with the following table : 
 
 Class. 
 
 I. 
 
 II. 
 
 III. 
 
 IV. 
 
 V. 
 
 VI. 
 
 VII. 
 
 VIII. 
 
 IX. 
 
 M 
 H 
 E 
 
 13-6 
 67-8 
 18-6 
 
 15-6 
 
 55-8 
 28 
 
 22-4 
 50-5 
 26-4 
 
 307 
 41-3 
 27-3 
 
 38-4 
 34-7 
 26-4 
 
 41-3 
 34-5 
 24-2 
 
 42 
 32-4 
 25 
 
 42-8 
 36-2 
 21 
 
 417 
 40 
 18-3 
 
 Total. 
 
 100 
 
 100 
 
 100 
 
 100 
 
 ,100 
 
 100 
 
 100 
 
 100 
 
 100 
 
 Unfortunately Erismann tells us nothing as to the 
 degree of H. Moreover the indications of facultative H 
 are well known to fluctuate ; on one day + i *o, on 
 another + 1*5 is pointed out as the best glass, according 
 as the accommodation is more or less relaxed behind 
 the glass. 
 
 Erismann's tables of short sight agree very closely 
 with my own ; he often assumed accommodation spasm 
 when V was not perfect and there was much capillary 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 71 
 
 hyperaemia of the optic nerve. He found V i or > i 
 only in 85 per cent.; V < i and > 2 / 3 in 6*8 per cent; 
 and V < 2 /s in 7 '6 per cent. In the higher degrees of M 
 Erismann noted a diminution of V; but here he quite over- 
 looked 45 the fact that the stronger concave glasses would of 
 themselves lessen V because of their lessening objects 
 generally. Among 1,245 M y s Erismann's finding as to 
 atrophic changes in the choroid was thus : none in 5 
 per cent., moderate in 71 per cent., great in 24 per 
 cent. ; these cases of atrophic choroidal change were more 
 frequent in the higher classes than in the lower, and 
 they increased in number from 14 to 38 per cent, with 
 the school-years. With higher degrees of M than J /i2 he 
 invariably found staphyloma posticum, and in as many as 
 70 per cent, of the cases where M was > I /Q there 
 were great atrophic choroidal changes. 
 
 Erismann also noted muscular insufficiency in 32*6 per 
 cent, of all the M's. Extreme insufficiency and relative 
 outward squint were more common in the elder classes 
 and higher schools than in the lower. Even with the 
 lowest degrees of M there were 23 per cent, disturbances 
 of the muscular equilibrium, but their number increased 
 with the degrees of M. 
 
CHAPTER VIII. 
 
 CURVE DIAGRAM SHEWING THE INCREASE OF SHORT-SIGHTED SCHOLARS 
 FROM CLASS TO CLASS IN 24 GERMAN GYMNASIA AND REAL SCHOOLS. 
 
 90 
 
 85 
 
 80 
 
 75 
 
 70 
 
 65 
 
 65 
 
 60 
 
 Percentage of short-sighted scholars. 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 
 
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{^4 CHAPTER VIII. 
 
 As Bonders 46 had asserted that he had never seen 
 an eye constructed hyperopically become short-sighted, 
 Erismann's statements concerning the prevalence of H 
 and its gradual change into E and M naturally aroused 
 much criticism and doubt. In order to set the question 
 at rest, I had recourse to the decisive method of 
 examining a whole school with atropine. A combination of 
 favourable circumstances, occurring in 1877 in Schreiberhau, 
 a village of Silesia, in the Riesengebirge, enabled me to 
 make this experiment ; an experiment which involves, in 
 any case, no injury to the child. Such a permission 
 to atropinise a whole school has never been granted to 
 any oculist before or since.* 
 
 I atropinised first all the right eyes of the 240 
 children and, 14 days later, all the left eyes, since it 
 seemed too venturesome to paralyse the accommodation 
 of both eyes at once. (Homatropine, which dilates the 
 pupil for only a few hours, was not then in existence.) 
 My examination gave 47 the following results : (i) More 
 than 80 per cent, of the village children are appar- 
 ently emmetropic. (2) Anisometropia, or difference in 
 refracting power between the two eyes, is very rare. 
 (3) Ametropia occurs twice as often among boys as 
 among girls. (4) M had not yet shewn itself in i per 
 cent. (5) While only 4 eyes were found M, facultative- 
 manifest H was very common (77 per cent, in the right 
 eye and 64 per cent, in the left). (6) H m (manifest 
 hyperopia) is rather more frequent among girls than among 
 boys. (7) The number of cases of H m does not decrease 
 
 * While these proof sheets were being corrected, I received by letter some 
 information respecting the observations of Dr. Diirr, in Hanover, who examined 414 
 'eyes of school children by means of homatropine. This drug had the effect of relaxing 
 the accommodation of most of the scholars, after about 43 minutes ; but in a few 
 cases the accommodation spasm resisted the homatropine. No inconvenience con- 
 tinued to be felt by the children, when after the examination, the antidote eserine 
 was dropped into the eyes. Of the children examined, 79 per cent, experienced an 
 increase of distance of the far point. Thus Dr. Diirr, too, found, by means of 
 homatropine, accommodation-spasm to be an attendant symptom of M. The speedy 
 publication of Dr. Diirr's tables is in prospect. 
 
KFFRACTION OF THE EYES OF SCHOOL CHILDREN. 7g 
 
 from the 6th to the i3th year (a flat contradiction, 
 then, of the result obtained by Erismann in his examina- 
 tion of Town Schools). (8) Every degree of H m from 
 YSO to I /IQ occurred, H 1 /eo being the most common ; 
 the higher the degree, the rarer. (9) The average 
 degree of H m was x /53 f r tne right eye and I /QS for 
 the left. (10) Every apparently emmetropic eye became 
 hyperopic after the dropping in of atropine ; out of 299 
 eyes only 4 remained emmetropic on account of the 
 imperfect paralysing of the accommodation. (n) Every 
 degree of H* (total hyperopia) from 1 /go to l /r was 
 found, 1 /36 to l /2Q being the most frequent. (12) The 
 average degree of H* is low (^35 for the- right eye and 
 ! /50 for the left). The latent hyperopia disclosed by 
 atropine varied from o to 1 /9, the most frequent amount 
 being x /5o to ! /30- I n J 7 P er cent, of the whole number 
 of cases there was no increase of H. (13) No essential 
 difference appeared between boys and girls as to the 
 degrees of H m and H f . (14) Neither H m nor H t skewed 
 any decrease in degree according to the age of the child. 
 (15) Almost all apparently E children have V > i ; most 
 have V 2, many have V = 2 l fa, and some of them 
 even have V 3. Not one child in Schreiberhau, 
 when examined with Snellen's table of coloured letters, 
 was found to be colour-blind. 
 
 My experiment therefore confirmed Erismann's supposi- 
 tion that hyperopia is the normal condition of the eye 
 in youth. 
 
 In order to put an end to all arguments against the 
 possibility of proving the first statistical conclusions as to 
 the increase of short sight in schools, it seemed to me 
 to be of the highest importance to examine again as to 
 their refraction the same children of a school after an 
 interval of a few terms. I therefore examined 9 the pupils 
 of the Friedrich Gymnasium in Breslau, in May, 1870 
 and repeated the examination in November, 1871. At 
 
76 CHAPTER VIII. 
 
 the first examination 174 out of 361 children were found 
 abnormal, namely 35 per cent. M, 7 per cent. H and 
 6 per cent, with eye disease. From the seventh to the 
 first class I found the following increase in the number 
 of myopes: 13 per cent., 21, 27, 35, 48, 58 and 60 
 per cent. Twelve per cent, were found to be M l jw to 
 !/36, 47 P er cent - M^lw to i/ie, 25 per cent. M l /it to l / 8 , 
 and 6 per cent. M > 1 /s. After an interval of 18 
 months 103 E and 71 M had left the Gymnasium; only 
 84 previously recorded E and 54 previously recorded Af, 
 in all 138 scholars, could be re-examined. Of the 84 
 formerly E only 70 had remained E, while 14 (or 16 
 per cent.) had become M. The degree of M acquired 
 in the interval varied from l /w to 1 /2o. Of the 54 pre- 
 viously found to be M, 28 had developed a decidedly higher 
 degree of short sight in the year and a half. I found 
 not one instance of a decrease in the degree of M. 
 
 Both the lowest and the highest degrees furnished their 
 contingent to stationary and progressive M as follows : 
 1 /36 was progressive in 30 per cent, cases. . 
 
 ,, 
 
 
 
 69 
 00 
 
 43 
 
 100 
 
 M^IT i/4 ,, M 66 
 
 Thus out of 54 M's examined there were 28 ( = 52 per 
 cent.) progressive. 
 
 The average degree of M in all the progressive cases 
 was in the first examination M ^ ; in the second 
 M = j^ ; the average increase, therefore, in the short 
 space of a year and a half was M 1 /^. 
 
 With regard to V, it is important to state that all 
 the children found E in tire first examination and 
 M in the second had retained their full V; in two cases 
 only of stationary M (out of 26 ) V had decreased to 
 2 /s and 2 /5 respectively. Among the 28 progressive M's 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. JJ 
 
 23 had V = i a year and a half before ; in 4 of them 
 it had now fallen to 2 /3 and 4 /s- Five progressive M's 
 had in the first examination V = 2 /s ; in none of these 
 was there any decrease. Staphyloma had appeared in 
 14 of the scholars who had passed from E to M. 
 Among 26 stationary M's the cases of staphyloma had 
 increased from 7 to 14. There were twelve cases of 
 stationary M in which no staphyloma had developed 
 itself. Among 28 progressive M's the first examination 
 shewed 15 cases of staphyloma; now there were 22. 
 Thus 10 per cent, cases were found of changes in the 
 background of the eye which had taken place in the space 
 of three half-years. 
 
 These results were confirmed by Dr. A. v. Reuss, 15 
 who repeated the examinations in the Leopoldstadt 
 Gymnasium in Vienna in the years 1874, 1875 and 
 1876. He had tested with the ophthalmoscope all the 
 short-sighted scholars and all those whose V was < i ; 
 he had also tested with convex glasses for H f every E 
 and had examined each eye separately. In May, 1872, he 
 found among 409 scholars 35 per cent. E, 41 per cent. 
 M and 20*5 per cent. H ' ; 2 per cent, astigmatic and 
 07 per cent, with eye - disease. The number of 
 J/'s increased from class to class: 28, 41, 49 and 48 
 per cent. H decreased from class to class : 30, 27, 14 
 and 12 per cent. The low degrees of 7/ 1 / 60 V 36 were 
 found in 85 per cent. Out of 162 examined with the 
 ophthalmoscope von Reuss was able to shew 41 cases 
 (or 25 per cent.) of accommodation spasm; namely, 16 
 among M I /QQ to 1 /36, 12 among M l /w to */24, 13 among 
 M l /zi to I /IG, ii among M I /IQ to ^12, 13 among M l /n 
 to 1 /6. No increase of the spasm was observed corres- 
 ponding to the rank of the class. Myopia of different 
 degrees in the two eyes was found in 102 scholars ; 54 
 had one eye E while the other was in 38 instances M and 
 in 1 6 instances H ; 7 had one eye M and the other H* 
 
78 CHAPTER VIII. 
 
 A year later a second examination was held in the 
 same school, but unfortunately without the ophthalmoscope. 
 Only 211 of the children were present. In 42 per cent, 
 the refraction was the same ; in 46 per cent, it was 
 progressive and in 12 per cent, regressive. In the lower 
 classes more cases were stationary than in the higher. 
 71 per cent, remained E, 19 per cent, had become M 
 and 10 per cent. H. Of the short-sighted scholars 28 
 per cent, were stationary, 61 per cent, progressive and 
 ii per cent, regressive (afflicted, therefore, with accom- 
 modation spasm). Owing to the lack of ophthalmoscope 
 and atropine these numbers must be received with caution. 
 
 The third examination conducted by von Reuss 25 took 
 place in the year 1875, when 201 scholars were present 
 and the following results were obtained : 
 
 Altogether. After i Year. After 2 Years. After 3 Years. 
 
 Stationary - 42 per cent. 37 per cent. 28 per cent. 
 
 Progressive*- 47 50 61 
 
 Regressive - 10 n 10 
 
 Stationary. Progressive. Regressive. 
 
 Further, from 1872 1875: 56 E 37 E 10 
 
 Mis Mn M 8 
 
 Hi2 H^2 Hi6 
 
 More precise details of the increase in the separate 
 degrees are given in the original work. Only 12 per 
 cent, of the M's proved to be unchanged after three 
 years. Accommodation spasm was also found, but there 
 was no case of regression with M > l /u. In comparing 
 the results obtained by test types and ophthalmoscope 
 v. Reuss found: (i) That in a not large number of 
 eyes the progression is only apparent, being caused simply 
 by spasm. Spasm may exist for years without altering 
 the construction of the eye. (2) That in continuous 
 spasm the actual condition of the refraction ib altered in 
 a progressive direction and that this is the most usual 
 case. (3) That it is by no means unusual for the 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 79 
 
 progressive changes to take place without simultaneous 
 accommodation spasm. The origin, therefore, or the 
 increase of M is not always to be looked for in a 
 convulsive tension of the ciliary muscle. 
 
 With all due respect for the laborious ophthalmoscopic 
 examinations conducted by most of the later writers, 
 who have tested the refraction of all the children con- 
 cerned, it must be stated that these examinations are by 
 no means infallible. I have often enough seen that even 
 with plane mirrors and in large spaces the accommoda- 
 tion was not wholly relaxed, nay that in some cases the 
 mirror first really brought it into action ; this fact has 
 also been acknowledged by v. Reuss and Stilling. These 
 lists of observations are, therefore, not absolutely trust- 
 worthy ; to make them so, it would be necessary that 
 every individual child examined, and if possible the 
 examiner himself, should be atropinised. For questions 
 of hygienic statistics, reading and lens tests in the 
 case of school children will doubtless retain in the 
 future the high value now accorded to them. Conrad 20 
 also, who examined the whole number of children most 
 carefully with glasses and ophthalmoscope, is of opinion 
 that with the ophthalmoscope one can never be sure 
 that the accommodation muscle is entirely relaxed, but 
 he nevertheless considers that atropine makes an extremely 
 slight difference in the results. On examining 3,036 eyes 
 with reading tests, he found n per cent. //, 55 per 
 cent. E and 32 per cent. M : with the ophthalmoscope 
 the percentages were 47 H, 29 E and 22 M. He also 
 agrees with Erismann that H slowly passes through E 
 into M. With the ophthalmoscope he found in the lowest 
 class 70 per cent. H, in the highest only 22 per cent. ; 
 E in the lowest class 25 per cent., in the highest 24 
 per cent, and in the intermediate classes 30 to 35 per 
 cent. ; while according to the ophthalmoscope M increased 
 from 4 to 51 per cent, and according to the reading 
 
80 CHAPTER VIII. 
 
 test from 1 1 to 62 per cent., so that about 10 per cent, 
 were cases of accommodation spasm. 
 
 We find that repeated examinations of the same 
 scholars were made afterwards by Ott 48 for Lucerne, by 
 Netoliczka 42 for Graz and by Florschiitz 43 for Coburg 
 The investigations of this last are of the highest interest, 
 because they establish a decrease among the number of M's 
 in the newly-built "school-palaces" Thus in the municipal 
 schools, in the year 1874, 12 and 14 per cent, of the 
 scholars were M, and in 1877 there were only 4 and 7 
 per cent. Among all the 2,323 examined in 1874 there 
 were 21 per cent. M, and in 1877 only 15 per cent. 
 
 Very valuable also are the most recent contribution 
 to our knowledge of the subject, those, namely, made by 
 Erismann* in St. Petersburg, which I did not see till 
 after the completion of this work. 
 
 In the year 1876 Erismann was able to test for the 
 second time the refraction of 350 eyes, examined by 
 himself in 1870, six years earlier. Only 23 of these eyes 
 were found to be in the same refractive condition. In 
 67 per cent, the refraction had increased, thus : 
 
 // had decreased in 7 per cent, of the eyes. 
 H had passed into E in 8 
 
 H M in 13 , 
 
 E M in 16 
 
 M had increased in 25 ,, ,, 
 
 The refraction had decreased in 9 per cent., thus : 
 H had increased in 3 per cent of the eyes. 
 E had passed into H in 5 ,, ,, 
 
 M had decreased in 0*5 ,, " 
 
 M had passed into 'E in 0*5 ,, 
 
 It is therefore beyond doubt that a change of re- 
 fraction takes place in children's eyes during school-life 
 and in the very great majority of cases this change is 
 
 * Handbuck d. Hygiene u. der Gewerbekrankheiten, herausg. v. Pettenkofer u. 
 Zeimssen. IT. 2. Hygiene der Schule, bearbeitet v. Dr. Erismann. p. 30. 1882. 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 8 1 
 
 progressive, that is, the axis of the eye becomes longer. 
 " The relatively few cases of regressive refraction may 
 be accounted for," says Erismann, " almost without ex- 
 ception by the fact that, owing to a high tension of the 
 accommodation, hyperopia, previously latent, becomes 
 manifest. It is seldom found that the eye of a scholar, 
 even when it is not yet really myopic, but has only an 
 apparent myopia owing to accommodation spasm, returns 
 afterwards to its normal condition. The accommodation 
 spasm almost invariably developes those permanent 
 changes which characterise the myopically constructed 
 eyeball. By way of example, I will only mention a few 
 cases observed by me of changes of refraction in the 
 eyes of school children : 
 
 77 1 /36 was changed into M 1 J2\, 
 
 and it is an important fact that in these cases not unfre- 
 quently there was proved a decrease of the power of sight 
 
 Again, it may be a matter of general interest that in 
 the only examination which has hitherto been held in a 
 Kindergarten (a very careful examination under Koppe 23 
 in Dorpat) not one single case of myopia was discovered, 
 while there were 98 per cent. H and 2 per cent. E. 
 
 By way of appendix, I may mention the results found 
 by examining the eyes of students. In the years* 1861-1865 
 Dr. Gartner examined 138 students of the Evangelic- 
 Theological Foundation in Tubingen and found the 
 percentage of M to be 8 1. On making a summary of 
 the years 1861 to 1879 (after a second examination), he 
 found that of 634 Evangelical Divinity Students 79 per 
 cent, were M. - 
 
 Donders had already uttered these apt words : "It 
 would be of the highest value if we could obtain accurate 
 
82 CHAPTER VIII. 
 
 statistics concerning the amount of ametropia existing at 
 a given time in a special class of persons, for instance, 
 the whole of the students of a university, in order to be 
 able to compare these statistics with the results of repeated 
 examinations at later dates. Now if it were shewn by 
 this means and I have little doubt that such would 
 be the case that short sight among the educated classes 
 is progressive, this would be a very grave symptom, and 
 we should be bound seriously to consider how this pro- 
 gress of short-sight could be arrested." 
 
 Such a table of statistics I 50 tried to begin at Breslau 
 in the year 1867, but without success, since I was not 
 able to induce all the students to submit to examination. 
 Out of 964 students only 410 presented themselves. 
 Among these 60 per cent, were M, distributed as 
 follows : 
 
 Students of Catholic Divinity 53 per cent. 
 Law 55 . 
 
 Medicine 56 
 
 ,, Evangelical Divinity 67 ,, 
 
 Philosophy 68 
 
 In the year 1880 I again tested 51 108 medical students, 
 and found 57 per cent. M ; before the University exami- 
 nation, known as Examen Physicum 52 per cent., and 
 after it 64 per cent. M. Seggel 35 proved that out of 
 284 volunteers and cadets who had left the gymnasium 
 there were 58 per cent. M. Collard 52 examined the eyes 
 of the students in Utrecht in the winter of 1880, 410 
 out of the 550 students being present. Of these 820 
 eyes 27 per cent, were M y in the following proportions: 
 Students of Divinity 23 per cent. 
 
 ,, Medicine 26 ,, ,, 
 
 ,, Law 29 ,, 
 
 Natural Science 32 ,, ,, 
 Pharmacy 31 
 
 Philosophy 42 . 
 
REFRACTION OF THE EYES OF SCHOOL CHILDREN. 83 
 
 Collard did not find more short-sighted students 
 among the older than among the younger men ; on 
 the contrary, there was a decrease thus : From the 
 1 8th to the 2Oth year, 30 per cent.; from the 2ist to 
 the 23rd, 28 per cent., from the 24th to 27th, 37 per 
 cent. But then, the oldest students are by no means 
 always the most diligent. 
 
84 CHAPTER IX, 
 
 CHAPTER NINTH. 
 
 MYOPIA AMONG SCHOOL CHILDREN OF DIFFERENT NATIONS. 
 
 It has often been affirmed that the German schools 
 are the nurseries of short sight ; but it can be seen, 
 even from Table I. in Chapter VIII., that there is no 
 lack of short-sighted children in other countries. 
 
 According to Maklakoff 11 the percentage of M is 
 lowest among the Georgians and Armenians of the 
 Caucasus ; but in Woinow's German report numbers are 
 not given. Exactly the opposite opinion is held by 
 Reich 37 , who found in the four schools examined by him 
 at Tiflis, and containing 1,258 scholars, more M's among 
 Georgians and Armenians than ,. among Russians (see 
 Table I.). For instance, the percentages of M in the gym- 
 nasium were thus : Armenians 38 per cent., Georgians 45 
 per cent, Russians 30 per cent. He also found, especially 
 among the Armenians, the higher degrees of M, and a 
 rapid rise of the percentage from class to class. He was 
 struck, too, by the large and prominent eyes of the Arme- 
 nians and Georgians. In the lowest classes of the 
 gymnasium at Tifiis Reich found only 12 per cent. M, 
 in the highest classes 71 per cent. ; on the other hand, 
 V was 9 /6 in 52 per cent, of the scholars. Dor's 19 state- 
 ment, "the further south, the greater number of normal 
 eyes," Reich considers open to serious question and he quotes 
 with emphasis Mannhardt as pointing out for special notice 
 the national tendency to short sight among the Italians. 
 
 In England up to the present time* only one examination 
 has been held. In the year 1880, Dr. Priestley 
 
 * The date on Dr. Cohn's title-page is 1883. [Eng. Editor.] 
 
MYOPIA AMONG SCHOOL CHILDREN OF DIFFERENT NATIONS. 85 
 
 Smith 53 examined 1636 school children and found 5 per 
 cent. M, while among 357 students of Training Colleges 
 he found 20 per cent. 
 
 In France investigations were set on foot in 1874 at 
 Lyon by Gayat 54 , who examined nearly 600 scholars 
 taken "au hasard, ou sur la demande du maitre." To 
 estimate the ^/-number, obtained in this manner, as 3 
 per cent, of the total number of scholars is altogether 
 inadmissible. Dor at first relied on Gayat's statistics 
 and concluded that M prevailed far less in France than 
 in Germany ; but he 36 afterwards examined for himself a 
 lyceum in Lyon and there found 23*4 per cent. M (a 
 percentage like that in German gymnasia). Nicati 40 ex- 
 amined in Marseille 3434 scholars by means of spectacles 
 and ophthalmoscope and found in the Jewish primary 
 schools 15 and 10 per cent. M, against 8 and 7 per 
 cent, in the Christian primary schools. He considered 
 this to be the best of evidence for the heredity of M, 
 since the Jewish scholars were children and grandchildren 
 of tradesmen who could read and write, while the 
 Christian scholars came of a stock of labourers, mechanics^ 
 and peasants, and were the first generation in their 
 families to enjoy school education. 
 
 Pflliger 55 , on examining 529 Swiss teachers from 20 
 to 25 years of age, found that there was more short 
 sight among the Germans than among the French. 
 154 French Swiss had 14*3 per cent. M and 357 
 German Swiss 24*3 per cent. 
 
 Italian Swiss. German Swiss. Total. 
 
 M > */24 4*5 per cent. 12-0 per cent. 10*5 per cent. 
 
 M> 1/24 and */i2 59'o 4' 44 *o 
 
 -flfc> 1/12 and i/a 27-5 35-5 32-0 
 
 .#/ > !/s and !/6 9*0 10*0 io'o 
 
 M>*\* ' - 4'5 3'5 
 
 Emmert 27 examined 4 Swiss watchmakers' schools, and 
 found 71 per cent. //, 15 per cent. E and 14 per 
 
86 CHAPTER IX. 
 
 cent. M. Insufficiency of the internal rectus was very 
 prevalent, the percentage being 54. In the schools of 
 those places, too, where watchmaking was carried on 
 there was 22 per cent, insufficiency against 4 per cent, 
 in other towns. Emmert is of opinion that watchmaking 
 is very apt to cause muscular irregularity through the 
 use of the magnifying glass with a single eye and that 
 the tendency to. this muscular irregularity is especially 
 apt to become hereditary. 
 
 In America Callan 21 examined 457 negro scholars. 
 They were from 5 to 19 years of age, and attended 
 two schools in New York. Only 2*6 per cent, were 
 M\ 3 per cent, in the higher school, and only 1*2 per 
 cent, in the lower. There was no case of short sight 
 below the age of 10 years: the higher degrees l /s V 4 
 were only found among children above 14 years of age. 
 No short sight existed in the primary departments of 
 these schools ; the grammar departments had 8*2 per 
 cent, in the higher and 1*6 in the lower school respec- 
 tively. With spectacles Callan found only 67 per cent. 
 H y but with the ophthalmoscope, after he had dropped 
 atropine into his own eyes (certainly as desirable for the 
 examination as unpleasant for the examiner) he found 
 90 per cent. H. Loring 26 and Derby also examined 
 2265 eyes of school children in New York, and report 
 the same increase of M from class to class as that 
 noticed in Germany. It is interesting to learn that among 
 the children of German parents these examiners found 
 24 per cent. M, among children of American parents 
 only 20 per cent, and among children of Irish parents 
 only 15 per cent. The total j#/-number, however, was 
 smaller than in Germany, being 7 per cent, in the Primary 
 Schools, 12 per cent, in the District Schools, and 27 
 per cent, in the Normal Schools. 
 
 An examination organized by Agnew 31 , and carried out 
 by several medical men was held in various higher and 
 
MYOPIA AMONG SCHOOL CHILDREN OF DIFFERENT NATIONS, ? 
 
 lower schools of New York, Cincinnati, and Brooklyn : 
 1,479 scholars were examined with the ophthalmoscope 
 and glasses and the following results were obtained : 
 
 Citizens' Schools, Cincinnati - 10 per cent. M 
 
 Middle - 14 
 
 Normal Schools - 16 ,, ,, 
 
 Lowest Class, New York - 29 ,, 
 
 Freshman Class ,, - 40 ,, 
 
 Sophomore - 35 ,, 
 
 Junior - 53 
 
 Senior ,, ,, - 37 
 
 Academic Department, Brooklyn 10 ,, ,, ,, 
 
 Collegiate ,, 28 
 
 Hasket Derby 33 found in Amherst College, Boston, 28 
 per cent. M, in Harvard 29. Half of the short-sighted 
 ones had become more short-sighted by the following 
 year. After four years he repeated the examination and 
 saw that 10 per cent, of E had changed into M and 
 that 21 per cent, of M had increased in degree. In 
 1875 there were 51 per cent. E, 5 per cent. H and 
 45 per cent. M*. In 1879 there were 36 per cent. E, 
 13 per cent. H and 51 per cent. M. 
 
 We will add in conclusion that Collard 52 found only 27 per 
 cent. M among 790 eyes of Dutch students, against 40 
 per cent, among 30 eyes of German students in Utrecht. 
 
 From all the facts in our possession we can infer 
 with certainty only thus much : that in other countries 
 too few examinations have been held for a statistical 
 comparison with Germany, but that in the whole civilised 
 world the number of short-sighted scholars increases with the 
 requirements of the school and with the rank of the class. 
 
 * While this proof-sheet was under revision, I received an interesting report of 
 the first examinations held in S. America. The author, Mr. P. F. Roberts, tested 
 6,163 scholars and found only 260 cases (=4*2 per cent.) M. Enviable people! 
 
 Examen de la Vision practicado en las escuelas publicas de la ciudad de Buenos 
 Aires, capital de -la Republica Argentina, Buenos Aires, 1882. 
 
88 CHAPTER x. 
 
 CHAPTER TENTH. 
 
 INFLUENCE OF HEREDITY ON THE SHORT SIGHT OF SCHOOL^ 
 
 CHILDREN. ,. A-^ 
 
 As the fact of the enormous increase of M during the 
 time spent at school could no longer be denied, attempts 
 have been made to explain the origin of this "disease 
 of civilization " and champions have not been lacking for 
 the view which entirely acquits the school and gives the 
 blame exclusively to heredity or exclusively to home 
 occupations. 
 
 Bonders 46 says : "My experience shows that M is almost 
 always inherited and, when inherited, exists in the child 
 at least in the form of a predisposing tendency ; but 
 that it can nevertheless, without an original disposition* 
 be developed in the normal eye by over-exerting the 
 accommodation." Bonders adds no statistics of percentage. 
 
 Now if we meant to arrive at any definite conclusions 
 concerning this question, we should be compelled to 
 examine personally the parents of the school-children as . well 
 as the children themselves. That, as yet, has nowhere 
 been done. In examining short-sighted children I 6 have 
 asked them the following questions : ( i ) Boes your father 
 or mother wear spectacles or an eye-glass ? (2) Bo they 
 use them out of doors? at home? for writing or sewing? 
 (3) Bo you see better or worse with your parents' 
 glasses, near to you or far off? (4) If your parents do 
 not wear glasses, do they complain of not being able to 
 see well at a distance ? (5) [In the higher classes.] Bo 
 your parents wear concave or convex glasses ? By further 
 questions put to the parents I obtained much additional 
 information. In many cases, indeed, father and mothei 
 
INFLUENCE OF HEREDITY. 89 
 
 had long been dead ; moreover, none of the instances 
 appear in which parents were M, but in so slight a 
 degree as to cause no complaint or need of spectacles. 
 On the whole I learned in this way that out of the 
 1,004 M scholars that I discovered only 28 ( = 27 per 
 cent, of all M and 0*2 per cent, of all the scholars) had 
 a short-sighted father or mother. In n cases the mother 
 was M and in 17 cases the father. To judge from this 
 very small number of instances, the M seems to be 
 transmitted from mother to daughter and from father to 
 son. In the village schools and higher girls' schools, 
 the children gave no evidence that any parent was M. 
 I attach no great importance to these numbers, but they 
 appear to me to shew that the number of short-sighted 
 
 1 children with short-sighted parents is by no means so 
 
 I great as is commonly supposed. I am confirmed in this 
 belief by the fact that in the v course of years I have 
 in my private practice examined a very great number of 
 myopic children brought to me by parents who were not 
 short-sighted. 
 
 Erismann 10 , too, has taken the prudent step of collecting 
 facts respecting the M of parents. He thus found M 
 fathers more numerous than M mothers. The father was 
 M in 5 per cent, of all cases and in 16 per cent, of 
 
 \ all M. The mother was M in 3$ per cent, of all cases 
 and in 12 per cent, of all M. Both parents were M 
 
 'in 10 per cent, of all cases and in 3 per cent, of all 
 M. Thus, in all, the short sight was inherited in 30 
 per cent, of all M examined. 
 
 , He heard of myopic brothers and sisters in 24 per 
 
 cent, of the M cases and of myopic brothers and sisters 
 
 without myopic parents in 16 per cent, of the M cases. 
 
 Among the myopic girls the percentage of M mothers 
 
 was rather higher than among the M boys, but both 
 
 j among M boys and M girls the father was M in more 
 than half the cases ; among the M boys 57 per cent. 
 
9O CHAPTER X. 
 
 of the fathers were M against 42 per cent, of the 
 mothers ; and among the girls 52 per cent, of the fathers 
 against 48 per cent, of the mothers. 
 
 Erismann further found among children of M parents 
 no atrophy of the choroid in 3 per cent, of short-sighted 
 parents against 5 per cent, of all the short-sighted 
 children ; a moderate degree of atrophy of the choroid 
 in 67 per cent, of the children of short-sighted parents 
 against 7 1 per cent, of all the short-sighted children ; a 
 high degree of atrophy in 29 per cent, of the children 
 of short-sighted parents against 24 per cent, of all the 
 short-sighted children. He considers that there is nothing 
 surprising in the preponderance of cases of great choroidal 
 change among scholars with M parents, since "the inherited 
 structural tendency of any organ necessarily becomes 
 perceptible in the later development of the organ in such 
 wise that the abnormal tendency is more strongly declared 
 than it is when it has been contracted for the first 
 time during the lifetime of the individual. In this 
 manner we should have the by no means cheerful pros- 
 pect that, a few generations hence, all Europeans, or at 
 least all those living in towns, will be short-sighted." 
 / Nagel 57 does not set much value upon Erismann's 
 statistics as to the heredity of M and rightly asks 
 "Where are the parallel lists for comparison? Heredity 
 will not surely be taken for granted in the 30 per cent, 
 above mentioned? If practical conclusions are to be 
 obtained, closer investigations seem necessary and, especially, 
 more definite questions must be answered. For instance, 
 do we find more short sight in respect of number of 
 cases and of degree, more choroidal changes, more insuffi- 
 ciency among 100 children of short-sighted parents than 
 among 100 similar children of not short-sighted parents?" 
 JL As conclusive evidence I should only accept statistics 
 based on an examination of some thousands of children 
 and of their parents (and, where possible, of their 
 
INFLUENCE OF HEREDITY. 9! 
 
 grandparents). Twelve years ago I endeavoured to contri- 
 bute towards the solution of this question by applying for 
 permission to examine, at the opening of a gymnasium 
 in a small provincial town, the candidates for admission 
 and the parents who brought them. Unfortunately, how- 
 ever, I was unable to obtain the authoritative permission 
 without which the project cannot be carried out. 
 
 In future it is to be hoped that the authorities will 
 themselves promote investigations of this kind and then 
 if as is not at all improbable the heredity of short 
 sight or the hereditary tendency to short sight should be 
 positively demonstrated, we should be doubly bound to 
 make every exertion to prevent the increase of M. 
 
 The reports already published are based on too small 
 numbers. Dor 19 , for example, found in the real school 
 at Bern in 1874 among 42 M 25 ( = 59 per cent.) 
 whose myopia was inherited. 
 
 Scheiding 22 in Erlangen found, as I did, myopia trans- 
 mitted generally from mother to daughter and from 
 father to son. But, as Nagel aptly observes, it is a very 
 venturous assertion on Scheiding's part that, having regard 
 to their H and E brothers and sisters, the M of 76 
 per cent, of the M scholars must be considered as 
 acquired, while in the remaining 24 per cent., having 
 regard to the M of the brothers and sisters, it must be 
 safe to assume an hereditary predisposition, 
 
 Nagel's hint respecting parallel lists was taken by 
 Pflliger 24 . who found in the public schools of Lucerne : 
 (i) In 100 families with 449 children and no hereditary 
 predisposition scarcely 8 per cent. M children. (2) In 
 100 families with 395 children and hereditary predispo- 
 sition 19 per cent. M. (3) In real schools and gymnasia, 
 in 85 families with 280 children without , hereditary 
 predisposition 17 per cent. M. (4) In real schools and 
 gymnasia, in 55 families with hereditary predisposition 
 26 per cent. M. On the whole, therefore, with 
 
9-2 CHAPTER X. 
 
 short-sighted parents, short-sighted children were more f 
 numerous. Pfliiger does not assume that in 31 per cent, 
 more cases those scholars in gymnasia and real schools, 
 who belong to families in which short-sight is hereditary, 
 must inevitably become M, but that these 31 per cent., 
 at least in part, represent a greater predisposition to M 
 which with injurious circumstances is developed but with 
 favourable circumstances may remain latent. In the lower 
 and higher schools the difference for the worse in the 
 M families remained about the same, namely, 10 per 
 cent. "This number" (10 per cent.) says Pfliiger, "gives 
 us an approximate idea of the frequency of hereditary 
 myopia as far as it asserts itself as an unpreventible 
 and incurable structural defect ; and, if anything speaks 
 for the frequency at the present day of acquired short 
 sight, it is this number 10 per cent. This investigation 
 affords one proof more of the great importance attaching 
 to the influence of outward circumstances, especially the 
 school, upon the development of short sight." 
 
 Further, the opinions of oculists on this question of 
 the heredity of M are widely divergent. Von Arlt 58 , who 
 deserves the chief credit of demonstrating the anatomical 
 basis of M, says very justly : " Short sight itself cannot 
 be looked upon as hereditary, but only the tendency to 
 short-sight. It is not proved that the eye developes into 
 the elongated structure by reason of a structural impulse 
 existing within it ab ovo. The anatomical changes found in 
 the M eye still possessing normal V are against such an 
 assumption." As a proof that M may be acquired without 
 any inherited tendency v. Arlt instances his own case. 
 He belongs to a family in which there never was any 
 short sight. When a child he was himself , and he did 
 not become M^\u until he had studied hard from his 
 1 3th to his 1 6th year. 
 
 Loring 59 considers the heredity, although not statistically 
 proved, to be beyond all doubt, but he thinks that its 
 
INFLUENCE OF HEREDITY. 93 
 
 influence is over-rated. As one of the essential "changes 
 of the conditions of existence " which affects the mass 
 of people and is capable of altering the type of the 
 eye, he mentions compulsory school attendance. 
 
 Nicati 40 regards his results above referred to in the 
 Jewish Schools of Marseille (page 85) as evidence of 
 the heredity of M. Kotelmann 28 , too, attaches great 
 importance to heredity. In 24 cases he found both 
 parents short-sighted, and in 20 of these cases the M was 
 transmitted to the sons. In 112 cases the father only 
 was M, in 50 per cent. M was transmitted to the sons. 
 In 43 cases the mother only was M, and in 25 her 
 sons were M. 
 
 Javal 60 , on the contrary, lays very little stress on heredity. 
 He thinks that American children of German parents are 
 more short-sighted than children of other descent not 
 because of heredity, but because Germans make their 
 children work a great deal out of school, and often at 
 night by a bad light. That may easily be, but when 
 Javal asserts that the increase of the number of the 
 M in the higher classes is no proof of the increase of 
 myopia, he stands quite alone in this opinion. He believes 
 that only the short-sighted children stay at school and 
 that the non-myopic children .in the higher classes leave ; 
 he also considers it an exception to find M developing 
 itself after 12 years of age. Whereon Nagel justly 
 observes : " Two bold assertions ! " 
 
 From all the opinions which experts have communi- 
 cated to us only thus much follows : that the question 
 of the heredity of M is not yet decided ; that the trans- 
 mission of the tendency to M is at least highly probable^ 
 but that in very many eases, without any hereditary 
 predisposition, M is developed by other causes. 
 
ff 
 
 94 CHAPTER XI. 
 
 -. 
 
 CHAPTER ELEVENTH. 
 
 SCHOOL DESKS. 
 
 Whatever opinion we may hold about hereditary tendency, 
 we cannot be blind to the fact that almost all children 
 come to the lowest class of our schools with perfectly 
 sound eyesight, while from class to class there is an 
 increase in the number and in the degree of cases of 
 short sight. So far back as eighteen years ago I sought 
 an explanation of this fact in various local circumstances 
 of school work. H. Weber 44 in his last and beautiful 
 treatise comes to the conclusion that "the earliest and 
 principal influences for the development and spread of 
 short sight are to be found in school work. A most 
 accurate analysis of all the concurrent circumstances is 
 necessary in order to determine where the chief causes 
 of injury are lurking, whether in the length of occupation 
 or in the kind of occupation, and if the latter, which 
 kind of occupation is to blame?" 
 
 Many years ago, the orthopaedic doctors had pointed 
 out the school desk as the thing above all others tending 
 to originate spinal curvature. The American writer Barnard, 
 in his great work on School Architecture (1860), upheld 
 the principle that during writing the form ought to be 
 close up to the desk. Schreber 64 , Schraube 103 , Passavant 104 , 
 Freygang 105 , Fink 106 , and Zwez 66 also insisted on the 
 importance, for the scholars' normal growth, of well- 
 constructed desks ; but they did not see wherein lay the 
 very chief defect of the old school desks. 
 
 The question was dealt with from a wholly new point 
 of view by Dr. Fahrner of Zurich who in his small 
 but classical book, " The Child and the School Desk " 
 
SCHOOL DESKS. 95 
 
 (1863) pointed out why the children could not possibly 
 sit upright for long at a time at the old desks, why 
 they were forced to fall forward and why a thorough 
 reform in the make of school desks was necessary. 
 
 No one before or since Fahrner has more accurately 
 described the mechanism of the collapse of the child's 
 posture when writing ; and therefore it seems best to 
 quote from this investigator, who died all too soon, the 
 description of this important process. 
 
 " Before the writing begins," says Fahrner (p. 17), "the 
 children sit perfectly upright with both shoulder-blades thrown 
 back equally (that is, the shoulders are parallel to the 
 edge of the desk), and the slate or copy-book is so 
 placed before the child that its left margin lies a little 
 to the left of the middle of the body. But as soon as 
 the writing begins all the children move their heads 
 slightly forward and towards the left, without perceptibly 
 altering their attitude in any other way. Soon, however, 
 head after head drops down with a rapid jerk, so that 
 the neck now forms a considerable angle with the rest 
 of the spinal column. In a short time the upper part of 
 the back also collapses, so as to hang from the shoulder- 
 blades, which in their turn are supported by the upper 
 arm. From this moment the scholars are divided into 
 two groups, according to the part of the slate at which 
 they happen to be writing. Those who are writing on 
 the upper half of the slate or at the beginning of a 
 line are able to support themselves on both elbows, and 
 they let their chest sink straight forward against the 
 table. The back in this way becomes curved simply ; it 
 becomes what I call a round back. The eyes are from 
 3 to 4 inches distant from the desk and look straight 
 down upon the writing. For points of support the child 
 uses the front of the chest, the left elbow (which is 
 constantly moved outward till it is a long way from the 
 body) and the right fore-arm anywhere between the 
 
9 6 
 
 CHAPTER XI. 
 
 elbow and the wrist. But those scholars, who at the 
 critical moment are writing at the end of a line or near 
 the bottom of the slate, cannot any longer support 
 themselves on the right elbow, because it too much 
 Overhangs the table and is too far from the body. 
 They are therefore forced to lean on the left elbow 
 alone and, in so doing, not only to bend the spinal 
 column, but to twist it on its axis towards the right. 
 The position is that of the skewed back. The points of 
 support are the left side of the chest and the left 
 elbow, which lies very much to the left of the body 
 and forward from the body ; the head is bent towards 
 the left shoulder; the right arm, with its shoulder-blade 
 standing out like a wing, rests on the desk anywhere 
 between the elbow and the wrist; the eyes, now frequently 
 only from 2 3 inches distant from the writing, are rolled con- 
 siderably towards the right and almost squint over the paper. 
 " Exceptionally, a child pushes the copy-book aslant, 
 twists the spinal column towards the left, and leans upon 
 the right arm. In this case the left shoulder-blade 
 stands out like a wing and reminds us of the rare 
 
 instances in which we find a 
 
 girl, whose back is twisted, 
 
 having the left shoulder 
 
 higher than the right." 
 Accurate pictures of the 
 
 bad attitudes at the old- 
 fashioned school desks (Fig. 
 
 XXVII.) were afterwards 
 
 given by Frey (see Fig. 
 
 XXIX.) and Baginsky (see 
 
 Fig. XXVIII.) 
 
 Of course such an ex- 
 cellent observer as Fahrner 
 
 could not fail to perceive 
 
 in these phenomena the 
 
 FIG. XXVII. 
 
SCHOOL DESKS. 
 
 97 
 
 FIG. XXVIII. 
 
 working of a fixed physical law which the children 
 were compelled to obey, and that this law was the 
 law of gravitation. Fahrner decided very rightly that the 
 first movement by which the child leaves the normal 
 attitude is a reaching of the head forward to the left 
 and that this apparently unimportant movement is the 
 root of all the evil. After the experiences of many 
 years I cannot do otherwise than entirely agree with 
 him in this opinion. Unimportant as this slight movement 
 appears, it inevitably causes the whole subsequent ruin 
 of attitude. 
 
 "In the normal posi- 
 tion," says Fahrner, 
 ''the head has its 
 centre of gravity rest- 
 ing upon the bony 
 framework of the spine 
 and is supported by 
 it, so that the muscles 
 of the neck have 
 nothing to do but to 
 balance the head. That 
 slight stoop forward, 
 however, is enough to 
 push this centre of 
 gravity over the front 
 
 edge of the spinal column. The muscles of the neck must 
 now hold up the head if it is not to drop downward. 
 The work thus laid upon them is considerable. (The 
 best way of appreciating muscular work is to hold out one 
 arm horizontally for some time instead of letting it quietly 
 hang down.) The muscles of the neck are accordingly 
 soon tired out, their tension is relaxed and the work 
 now falls upon the muscles of the back. These in their 
 turn are soon tired out and the child is then forced to 
 lean on other points of support. He tries first one or 
 
9 8 
 
 CHAPTER XI. 
 
 both elbows. The elbows support the upper arm, the 
 upper arm supports the shoulder blades and the body 
 hangs upon the shoulder blades until they also give way 
 and the chest must needs find a stay and support at 
 the edge of the desk." FlG XXIX 
 
 This inevitable neces- 
 sity, by which the body 
 hangs upon the shoulders 
 instead of the shoulders' 
 hanging upon the body, 
 leads to that further 
 collapse of attitude in 
 consequence of which 
 the head presently drops 
 down towards the writing 
 and the eyes are distant 
 from the writing only 
 3 4 inches. Since the 
 first slight reaching for- 
 ward of the head is the 
 
 cause of all the mischief, it must be prevented at any 
 cost. As the chief causes of this reaching forward 
 Fahrner points out the positive horizontal distance between 
 desk and form, and the false vertical distance (the 
 difference) between them. (See below.) 
 
 Fahrner's counsels were upheld from the very first by 
 Guillaume 107 in Neuchatel, and Parow 108 in Berlin. In spite 
 of thisjfpb efforts of these men, even so lately as 1865, met 
 with the greatest opposition. It was urged everywhere, and 
 with some reason, that if the desks were the cause of 
 spinal curvatures, the number of cases of crooked spine 
 ought to be much greater than was shewn by statistics. 
 The writers above quoted had certainly touched on the 
 importance of a good attitude with reference to eyesight, 
 but throughout they kept too exclusively to the orthopedic 
 point of view. 
 
UN 
 SCHOOL DESKS. 99 
 
 When in 1865 I had studied Fahrner's admirable work 
 and had begun my examinations of the eyes of the 
 Breslau school-children, the question pressed itself upon 
 me : "How far may the old desks in our schools be 
 answerable for the origin and development of short sight?" 
 
 To obtain an answer to this question, I 6 first of all 
 measured the height of 10,060 children in the 166 classes 
 examined. I then measured the desks with reference to 
 desk-height (back and front), desk-width, form-height and 
 form-width, difference and distance between desk and 
 form, between form and book-rest and between form 
 and foot-board ; height of next desk above form, 
 distance of next desk from desk's front edge, width of 
 book-rest, length of form, width of foot-board, space 
 allowed for each child to sit, &c. I thus found that 
 these old desks were opposed to every reasonable hygienic 
 requirement, and were set up quite arbitrarily and without 
 any reference to the height of the children in the classes. 
 Pupils 3 feet 6 inches and 5 feet 2 inches in height sat 
 at the same desk. (I am sorry to say that this occurs 
 even to this day in Breslau !) 
 
 But, apart from this fundamental error, I found that 
 the scholars, even when the desk was suited to their 
 height, were forced by the old forms to stoop forward 
 and bring the eye very close to the writing. That is just 
 how M can be produced and increased. (See chapter VII.) 
 
 The points which are of main importance hi school 
 desks are four : The Difference, the DistaiB|i the 
 Form-height and the Desk-slope. 
 
 (i) The Difference, that is, the vertical distance 
 between desk and form. The higher the desk-surface, 
 the nearer it is to the eye of a straight-sitting child. Thus, 
 the greater the difference, the more the child will have 
 to exert his accommodation. Now the writing ought 
 to be from 14 to 18 inches [35 45 cm.] from the 
 eye, for that is about the distance of a child's eye from 
 
100 CHAPTER XL 
 
 the elbow when hanging straight down and the text 
 of the school books should be easily legible at that 
 distance. If, however, the difference is great, so that 
 the elbows have to be considerably raised in writing, 
 the shoulders will not hang from the body, but the 
 body from the shoulders, and the writing hand will be 
 too near the eye. The distance between the upper arm 
 when hanging straight down and the seat-bones is, on 
 an average, } /s of the height of the whole body. As, 
 then, the elbow in writing is moved not only forward 
 but also slightly upward, it is necessary, in order to 
 obtain the proper difference, to add from i'6 to 2*4 
 inches [4 6 cm.] to 1 /% of the height of the body. 
 With girls it is necessary to add a few centimeters 
 more on account of their thicker under-clothing, so that 
 in their case the difference is about x /y of their height. 
 Now in the old desks, the difference is too great by 
 about from 3 to 8 inches [8 20 cm.] 
 
 (2) An exceedingly important correlative of the difference 
 is the horizontal Distance between desk and form. In 
 right arrangement of Distance lies the kernel of school- 
 desk reform. The greater the Distance the more the 
 body will have to fall forward -Hifthe form in order 
 that the arms may reach the paper ; and the more will 
 the head be obliged to drop and to get near the 
 writing. Thus, whenever we intend to sit upright at 
 a table for a considerable time, we instinctively push 
 the chair so far under the table that the table's edge 
 is vertically over the chair's edge or, if possible, over- 
 hangs it by an inch. For the upright position of the 
 head, therefore, the Distance must be nil or y still better, 
 negative. Now in the old desks the distance varied 
 between 3 and 6 inches ; it was never nil or negative. 
 Fahrner required a distance nil. Parow also said quite 
 rightly : "In writing, the form and desk should be so 
 near together that the edge of the desk almost touches 
 
SCHOOL DESKS. lOi 
 
 the child as he sits upright before it." Buchner 109 , 
 accordingly required 2 inches [5 cm.] negative distance, 
 and Hermann 110 2*4 to 2*8 inches [6 to 7 cm.] I 
 once proposed a minus distance of i inch ; but after 
 further observations I think that the upright position is 
 sustained still longer when the thigh is supported still 
 further towards the knee and therefore I agree with 
 Buchner, who requires a minus distance of 2 inches. 
 
 Let no one think that an inch is no great matter. 
 Here every inch is of consequence. No physician has 
 ever opposed the requirement of nil or minus distance, 
 although the school desk question has been keenly 
 discussed for the last 17 years. 
 
 The opposition has come solely from individual teachers, 
 who set up this strange plea : "A positive distance of 
 3 inches does no harm for, in order to counteract it, 
 the children have only to slide forward on to the edge 
 of the form'' 
 
 But the necessity of a nil or minus distance is made evident 
 beyond contradiction by the excellent physical investigation 
 of the conditions for an upright sitting posture published 
 by Professor Hermann Meyer in Virchow's Archives. 
 This work of Meyer is well popularised in Baginsky's 
 thorough Handbook of School Hygiene. In what follows, 
 the most important points only of Meyer's theory will be 
 touched upon. 
 
 At the lower part of the pelvis are the two seat-bones, 
 or lowest parts of the great hip-bones. They are curved 
 like a bow and rock easily. A line drawn through these 
 two seat-bones may be called the " seat-bones line." The 
 centre of gravity of the human body is situated in front 
 of the loth chest vertebra ; a line drawn perpendicularly 
 from that place to the ground is the line of gravity. 
 Now it is only when the line of gravity falls exactly 
 upon the seat-bones line that the body can remain at 
 rest in a sitting posture. The slightest movement of 
 
IO2 CHAPTER XI. 
 
 the trunk that displaces the centre of gravity, and 
 therefore also the line of gravity, must bring the line 
 of gravity either before or behind the seat-bones line, and 
 then a third point must be sought for which will secure 
 equilibrium in a sitting posture in spite of the instability 
 of the seat-bones. This third point may be situated 
 either before or behind the seat-bones line. We must 
 therefore distinguish between a forward and a backward 
 sitting posture. In the forward sitting posture the third 
 point of support is furnished by the front edge of the 
 form. The line of gravity may now fall on any part 
 of that surface \yhich is determined by the seat-bones 
 and the front edge of the form ; the nearer, however, 
 it approaches to the latter, the more easily is the 
 equilibrium disturbed. A quiet sitting posture, therefore, 
 will only be possible when the surface of the form on 
 which the thighs rest is very large ; things are best 
 when this surface extends forward as far as the knees. 
 If, moreover, the knees being bent at a right angle, the 
 feet are planted firm and flat on the floor, their resting 
 places form auxiliary surfaces of support. 
 
 No one, however, can remain in the forward sitting 
 posture for any length of time, because the trunk is 
 not immovably fixed in the hip joint but is joined 
 movably to the thighs. The attitude, therefore, is 
 only maintained by very complicated work of the pelvis 
 muscles. These muscles grow fatigued and the trunk, 
 obeying the law of gravity, would fall forward if 
 the chest or the arms did not support it by leaning 
 against the table. When we prop ourselves up with our 
 arms, we in a manner catch the body as it falls forward. 
 
 In the backward sitting posture, in which the line of 
 gravity falls behind the seat-bones line, the third point of 
 support, firmly connected with the seat bones, is found 
 in the end of the coccyx, the pel-vis being now inclined 
 backward. This point does not need to be determined, 
 
SCHOOL DESKS. 1 03 
 
 but is an immovable datum. But as the body, with 
 this backward inclination of the pelvis, would have to 
 fall far backward, its fall must be arrested by the back- 
 rest. The lower down the back-rest is applied, the 
 more upright is the position of the pelvis and the 
 trunk. Applied at the height of the last vertebra the 
 back-rest allows the best upright sitting posture. 
 
 In writing, the head is slightly bent forward on its 
 horizontal axis, the arms are stretched forward and 
 somewhat upward, and the body curved slightly forward ; 
 thereby the centre of gravity is moved forward and the 
 line of gravity brought in front of the seat-bones line. 
 Any arrangement, therefore, which brings the centre of 
 gravity further back will help the child to sit upright. 
 
 Now, on the contrary, the more we allow the child 
 to slide forward on to the edge of the form, the more 
 we bring the centre of gravity forward ; and the forces 
 which cause the body and head to stoop forward are 
 called more and more into activity with every inch of 
 plus distance because, with plus distance, the thighs are 
 not enough supported. 
 
 In every case of plus distance, as is proved by the 
 edges, quite worn away, of old forms, the child's 
 instinctive sliding forward brings about a posture not of 
 sitting but of perching. 
 
 This perching posture must at all costs be prevented, 
 as it soon leads to the head's falling forward. The extra 
 four or five inches of thigh, however, supported with 
 minus distance as compared with three inches plus distance, 
 are a powerful aid to longer endurance in an upright 
 writing position. 
 
 School-councillor Bock* has proposed a perching form 
 with three inches plus distance. Under the name of 
 " New Berlin Form " this old and faulty perching form, 
 
 * Volksschulfreund, 1868, No. 13. This "new and serviceable School Desk" was 
 also recommended in Stiehl's Prussian School Authorities' Central Paper, 1868, p. 486. 
 
CHAPTER xi. 
 
 with which the children stand badly and sit wrong, has 
 been introduced, I am sorry to say, during the last ten 
 years more and more into all new schools of Breslau*, 
 although all scientific treatises and all medical experts 
 condemn every plus distance as injurious to health. 
 
 t The recent reports of specialists in Strassburg 118 and 
 Darmstadt 44 , which have received the sanction of the 
 Government authorities in Alsace and Hesse, expressly 
 forbid any positive distance, as indeed positive distance 
 has long been forbidden in Switzerland. "This one fault 
 alone," says the Strassburg Commission, " is enough to 
 condemn the old school desks, and to make them the 
 more hurtful, the younger the children are who are 
 compelled to sit in them. So much has been said of 
 late years about the evil effects of positive distance that 
 we need not dwell long upon this point. It forces the 
 child, when writing, to support the upper part of his 
 body with his arms, to bring the chest far forward and 
 to bend the head downward too much. In this way it 
 brings the eye improperly near the paper and thus 
 creates short sight artificially. Moreover it gives the 
 child a kind of invitation to twist the spine sideways. 
 
 * There has been no lack of energetic public protests on my part. 
 
 t While these pages were being printed, Professor Esmarch, of Kiel, Medical 
 Privy Councillor, sent me a paper which had been distributed in the surgical hospital 
 among parents of children of crooked growth. It is entitled "Instruction about the 
 Sitting of School Children." It contains a complete vindication of the principles 
 above described and is so admirable in its classic brevity that this "instruction" 
 deserves the widest circulation. It says "School children become crooked and short- 
 sighted by crooked sitting on bad (old-fashioned) school forms. They sit crooked 
 when the form is too far off the desk, is too low for the desk and has no proper 
 back-rest. The school form, therefore, is always injurious except when the child 
 cannot help sitting upright upon it in reading and writing, and can so sit up for a 
 considerable time without growing tired. To effect this : (i) The form-seat must be 
 as far above the footboard as the child's leg is long, measured from the bend of the 
 knee to the sole ; (2) The form-seat must be as wide as the thigh is long, measured 
 from the knee to the back ; (3) The rounded fore-edge of the form-seat must be 
 from */s to li/g inches (2 3 centimeters) further forward than the desk's inner 
 edge ; (4) The seat must be high enough for the child to be able easily to place 
 his forearms on the desk in writing, -without raising his shoulders or bending down 
 his head and back ; (5) The lower part of the back must be sufficiently supported 
 in reading (cross back-rest). As these proportions vary with the growth of the 
 children, the seats ought to be readjusted by taking fresh measurements at least 
 every half-year. 
 
SCHOOL DESKS. IO5 
 
 With girls especially, slight degrees of spinal curvature 
 (so called 'high shoulders'), due to this cause, are not 
 uncommon." To these long-verified reasons the Strassburg 
 Report adds a fresh argument. At page 33 we find 
 " The injurious influence of positive horizontal distance is 
 scarcely less in reading, especially when the desk is not 
 sufficiently sloped. The effect is the most striking in 
 the case of the smaller children. The distance of the 
 form from the desk, and the insufficient support for 
 sitting lead them to prop the head on the left hand, 
 and at the same time to turn themselves to the right 
 about a vertical axis. This brings the left eye nearer to 
 the book than the right eye and makes a good deal 
 more difficult the convergence of the lines of sight, 
 until the right eye is at last left unused altogether. 
 Or the children cross their fore-arms upon the desk's 
 edge and, with heads bent far forward, rest the chin 
 on the back of one hand, bringing the eyes too near 
 the book. They thus exhibit in real life one of the 
 two attitudes, which we so much admire for beauty and 
 grace in the two angels at the feet of the Sistine 
 Madonna, but which must, from a hygienic point of 
 view, be utterly condemned." 
 
 The Darmstadt Report recommends none but Lickroth's 
 desks (see below) with a minus distance. 
 
 It is very gratifying to find that already even the 
 writing-masters themselves recognise in their manuals the 
 necessity of a minus distance ; Director E. Meier 112 in 
 Zwickau, for instance. 
 
 (3) The height of the form. If the legs are not bent 
 at a right angle at the knee and the feet resting with 
 the entire sole flat upon the foot-board, the feet must 
 be left dangling in the air. Then the child soon grows 
 tired. He tries to reach the floor with the tips of his 
 toes at least ; and in so doing he bends the thigh 
 downward, slides forward on to the edge of the form 
 
IO6 CHAPTER XI. 
 
 and presses his chest on the edge of the table. The 
 necessary result is a further collapse of attitude. (In 
 all this we are leaving quite out of account the hindrance 
 to breathing and the compression of the intestines.) The 
 height of the form must accordingly be equal to the length 
 from the knee to the sole, that is 2 /7 of the child's 
 height. The knee must be bent at a right angle. If 
 the form is too high, there must be a footboard at least 
 1 6 centimeters (6*4 inches) wide wider if possible so 
 as to take the whole sole. A footboard made of laths 
 placed like a grating may also be recommended (see 
 Fig. XL., Kayser's Desk). No attention is paid to any 
 of these proportions in the old school-desks. 
 
 (4) The slope of the desk. We can read easily, without 
 any stoop of the head, from a book placed vertically 
 before us. If the book slopes back at an angle of 45 
 with the horizon, reading is equally easy, because the 
 eyes can be directed downward without bending the head 
 forward. But if the book lies flat and the reader sits 
 upright, the eyes are turned downward very far. This, 
 continued for any considerable time, is very tiring and 
 so we prefer to bend the head forward. 
 
 It follows that the desk must not be horizontal but 
 sloped, A slope of 45, however, is not to be recom- 
 mended, because it would make writing difficult and the 
 writing materials would fall down. A ledge might be 
 put at the edge of the desk to keep the writing materials 
 from falling, but that would cut the arms. A slope of 
 i in 6 is the best. The old school desks are all flat and 
 therefore wrong. 
 
 It is a remarkably good arrangement to have at the 
 end of the desk a reading-slope, that is a rectangular 
 wooden frame, easily set up by means of two pegs and 
 corresponding holes. Professor Fialkowsky, of Vienna 
 (Bienengasse 4) has made little cardboard reading-slopes, 
 so easily packed up that they can be kept in a book, 
 
SCHOOL DESKS. IO7 
 
 In addition to these four cardinal points of the rational 
 school-desk, we have yet to speak of the Back-rest, the 
 Form-width, the Place-width, the Desk-width and the 
 Book-shelf. 
 
 (1) The back-rest. Meyer has demonstrated beyond all 
 doubt that no one can sit upright for any length of 
 time without a back-rest. The best is one which supports 
 the loins-bone and the lower vertebrae, so steadying 
 the pelvis and making it impossible for the body to 
 slide off the form. Indeed such a support has been in 
 use for some time for music-stools, on which the performer 
 has to sit upright for a considerable length of time, 
 while the hands must be freely moved in playing. " The 
 upright back-rest," says Meyer, "hinders the free movement 
 of the body by fixing an upper point of the spinal 
 column, while the cross back-rest allows perfect freedom 
 of movement, and this freedom, since a change of posture 
 is thereby possible, is the surest means of preventing the 
 fatigue caused by relaxing of the muscles and tension 
 of the ligaments. I ^have, therefore, no hesitation in 
 giving an unconditional preference to the cross back-rest 
 over the upright back-rest. Fahrner proposed as very 
 cheap a continuous back-support at the level of the loins. 
 But it must be acknowledged that such a back-rest 
 favours in some degree the tendency to crowd as many 
 children as possible into one class. It seems better, 
 therefore, to give each scholar his own separate cross 
 back-rest. 
 
 (2) The width of the form must be at least 12 inches 
 [30 cm.] so as to afford sufficient support to the seat 
 and thigh. 
 
 (3) The place-width must not be less than 25 inches 
 [64 cm.], as has been very properly ordered by the 
 Government in Breslau in the rule of June 24th, 1856. 
 By obeying this law over-crowding, too, would be 
 prevented. 
 
IO8 CHAPTER XI 
 
 (4) The desk-width must be at least 16 inches [40 
 cm.]. In Darmstadt, at Weber's recommendation, it 
 amounts even to 20 inches [50 cm.]. " If," says Weber, 
 " in drawing or writing the fore-arm, supported up to the 
 elbow, is so laid on the desk that its axis makes an angle 
 of 40 with the desk's edge, the perpendicular distance 
 of the point of the pen from the desk's edge, that is, 
 the altitude of the triangle formed by the arm, the 
 desk's edge and the perpendicular from the point of the 
 pen to the desk's edge, amounts to 12 inches [30 cm.]. 
 Now as copy books are generally 8 inches [20 cm.] 
 from top to bottom and as in writing near the bottom 
 of the page the arm must remain unmoved while the 
 copy book is pushed upward, the desk-width must on no 
 account be less than 20 inches [50 cm.], or the arm 
 will be unsupported during half the time it is at work." 
 
 (5) The bookshelves have also their hygienic importance, 
 as they must not come into collision with the knees. 
 They must be placed so high up as not to interfere 
 with the horizontal position of the thigh. Now as 
 these conditions would place the shelves no more than 
 3 1 /5 inches [8 cm.] below the desk, there would scarcely 
 be room for large book-satchels. If, again, the shelves 
 are more than 6 inches [15 cm.] broad, they come into 
 collision with the knees and disturb the erect attitude. 
 It is best, therefore, to have the book-shelf under the 
 form or (as is the custom in America) to hang the 
 satchels on hooks under the desk. 
 
 From the year 1865, when the first information was 
 published on the connexion of the school desk with 
 short-sight, interest ' in the school-desk question has been 
 universal. While cases of spinal curvature were detected 
 in but a small proportion of the children, the number 
 of cases of short-sight was enormous. All the medical 
 profession demanded a reform and there was in medical 
 publications an unusual unanimity as to the main points. 
 
SCHOOL DESKS. IOQ 
 
 The Strassburg report speaks very strongly : " We 
 look upon the doing away of the old school desks as 
 the most urgent necessity of school hygiene. Every 
 half year's delay causes fresh mischief." Weber, in 
 Darmstadt, considers the desk question not only as 
 solved rationally but as, by the proposals hitherto 
 unanimous of medical men, solved in a way that can 
 hardly be improved on. 
 
 There were but few teachers who, in accordance with 
 the medical requirements, endeavoured to construct new 
 models which should satisfy the requirements both of 
 teacher and doctor. Many teachers, unfortunately, were 
 opposed to reform. On the other hand, as was to be 
 expected, manufacturers took all the more lively interest 
 in the question. 
 
 Since the publication in 1867 of my " Examination 
 of 10,060 School Children's Eyes" a whole school-desk 
 industry has arisen. This industry increases in dimensions 
 year by year. In the Paris Exhibition of 1867 I 113 
 found only three different models ; at Vienna 62 in 1873 
 there were 47 different kinds of desks, at Paris in 
 1878 as many as 71, which I have described and drawn 
 in special accounts 63 . 
 
 The agreeable fact appeared that the number of desks 
 made on a wrong principle was less in each successive 
 exhibition and that Boards and Governments were more 
 and more taking an interest in school furniture. Thus, out 
 of the 22 desks exhibited in Paris in the year 1878 by 
 ministers or school authorities, only three were made on a 
 wrong principle, all the rest having a nil or minus distance. 
 
 It would lead me too far to notice here all the 
 variations tried in school desks since the right principles 
 gained a footing. I shall only mention the chief 
 types. We must distinguish between (A) desks with a 
 fixed nil or minus distance, and (B) desks with an 
 adjustable distance. 
 
110 
 
 CHAPTER XI. 
 
 (A.) Among the fixed desks, three models are worthy 
 of notice. 
 
 (1) Fahrners FIG. XXX. 
 desk (Fig. XXX.) 
 
 This has a nil 
 distance, correct 
 difference, correct 
 height of form and 
 correct slope. It 
 has also a contin- 
 uous cross back- 
 rest. Correct as 
 this desk is for 
 sitting, standing in 
 it is very difficult, 
 for big children almost impossible. This desk is therefore 
 little used in practice. 
 
 (2) Buchner's^ desk (Fig XXXI.). This is on 
 Fahrner's model, only that it has a minus distance of 2 inches 
 [5 cm.] and is a dual 
 
 desk. Each child, when FIG. XXXI. 
 
 he must stand up, can 
 step out from the desk at 
 the side; and in this act 
 many children stumble 
 over the woodwork which 
 joins the form to the desk. 
 Quite similar is the model 
 of Buhl and Linsmeyer, 
 only this, instead of a 
 book-shelf, has a book- 
 box, which is attached to 
 the form between the 
 places for the two scholars. 
 
 In America and Sweden many single-seated models are 
 made on this principle, 
 
SCHOOL DESKS. 
 
 I I I 
 
 
 FIG. XXXII. 
 
 
 
 O 
 
 
 
 lll^lft^-- 
 
 i \^^\ 
 
 (3) Loffels desk (Fig. XXXII.). In this model from 12 
 
 to 15 inches (30 
 38 cm.) is allowed 
 for each child and 
 next to each place 
 there is, cut out 
 from the desk, a 
 recess in which the 
 scholar can stand. 
 
 All these fixed desks are suitable for writing ; but it 
 is highly desirable that during the many hours when the 
 child is not writing, he should be able to sit comfortably. 
 In this respect all these desks are wanting; not one of 
 them gives the child quite enough room when he is not 
 writing. That he may stand comfortably, as well as 
 sit comfortably, a positive distance is required. Now as 
 it is never possible in one and the same fixed desk to 
 stand comfortably and sit aright, a desk with adjustable 
 minus distance is decidedly preferable. The tendency of 
 
 individual scholars to 
 injure movable desks 
 ought to be kept in 
 check by school dis- 
 cipline. 
 
 (B) There are three 
 methods of altering 
 the distance in these 
 adjustable desks. 
 Either the desk-slope 
 or the form, or both 
 maybe made movable. 
 (a) Among the 
 desks with movable 
 slopes we must distinguish between flap-desks and sliding desks, 
 (i) Parouts desk (Fig. XXXIII.). As far back as 1865, 
 Parow had recommended that the slope should be divided 
 
 FIG. XXXIII. 
 
I 12 
 
 CHAPTER XI. 
 
 FIG. XXXIV. 
 
 lengthwise, and [the movable half] turned down [so as 
 to continue the other] 
 for writing. Keicher, 
 a teacher in Ellwan- 
 gen, had constructed 
 a special kind of hinge 
 of which the iron part 
 did not come above 
 the surface of the 
 desk. (The drawing 
 may be seen in my 
 " Examination of 
 10,060 School Chil- 
 dren's Eyes.") The 
 Americans have simi- 
 lar flap desks with a very practical little reading-slope at the 
 back (Figs. XXXIV. and XXXV. Peard's study desk). 
 I at first recommended this kind of desk, but I was soon 
 obliged to admit 
 that even the best 
 hinges become 
 loose in time ; the 
 two surfaces com- 
 posing the desk 
 then no longer fit 
 together truly, and 
 the separate parts 
 warp. Moreover, 
 the desk, when half 
 obstructed by the 
 turned up flap, is 
 too small for books 
 and implements ; and to clear everything off the desk when 
 the flap must be turned down, has proved very inconvenient. 
 More' practical, beyond doubt, are sliding desks, which 
 have not to be cleared. 
 
 FIG. XXXV. 
 
SCHOOL DESKS. l l + 
 
 (2) Kunze's desk (Figs. XXXVI. and XXXVII.). 
 This desk can be readily drawn out like a "Secretary 
 desk." The mechanism is very complete; the leaf 
 
 FIG. XXXVI. 
 
 FIG. XXXVII. 
 
 runs in two grooves. When the desk is fixed at 
 a plus distance very convenient for standing, the leaf 
 
 covers the inkstand 
 so that, for writing, 
 the scholar is com- 
 pelled to draw out 
 the leaf and alter 
 the distance from 
 plus to minus, or he 
 cannot get at the 
 ink. There are many 
 varieties possible in 
 the bolts and springs 
 used for securing 
 the leaf when it is 
 drawn out. Kunzes 
 
 desk is beyond question one of the best. 
 
 (( UNI\ 
 
CHAPTER XI. 
 
 FiG. XXXVIII. 
 
 Von Reuss states that this desk was at first objected 
 to in Vienna as taking up too much space. Since 
 every desk ledge is made of one fixed breadth which 
 must be added on to the movable drawn-out part, 
 the sunk space which holds the inkstand represents 
 a dead loss of from 4 to 5 inches [10 13 cm.]. Paul, 
 master-engineer in Vienna, made 
 this sunk part (Fig. XXXVIII, /.) 
 movable by a very simple lever 
 action (/i) so that in drawing out 
 the desk, this sunk part (the "self- 
 acting ledge") rises of itself and 
 widens the desk. We can thus afford 
 to make the part to be drawn out 
 correspondingly narrower. With 
 this improvement the model is now being gradually 
 
 FIG. XXXIX, 
 
 introduced into all the schools of Vienna under the 
 name of the Vienna school desk, 
 
SCHOOL DESKS. 
 
 I 1 
 
 FIG. XL 
 
 (3) Cardofs desk (Fig. XXXIX.). In this desk 
 the leaf is drawn out by turning it upon an iron axle 
 placed under the further edge of the desk. This desk 
 also deserves commendation. 
 
 (K) Of movable 
 forms the simplest 
 are the American 
 (Figs. XXXIV. and 
 XXXV.). In these, 
 when they are made 
 for only one child, 
 the form is simply 
 turned up when the 
 child has to stand. 
 The following are 
 more complicated : 
 
 (i) Kaiser s 
 form (Fig. XL.), 
 patented. This is, 
 essentially, a seat which lifts up like those in a theatre, 
 
 FIG. XLI. 
 
 but the mechanism is original. The seat (which of 
 
Il6 CHAPTER XI. 
 
 \ 
 
 course is separate for each child) raises itself at a slight 
 push and leaves plenty of room to stand. But the child 
 can never sit with freedom as he can at a sliding or 
 flap desk. 
 
 (2) Lickroth's normal form (Fig. XL I.). Similar in 
 principle to Kaiser's, but the mechanism is different, as 
 the seat revolves and is arrested by a fixed beam. 
 The movement is very silent, and the seat falls back 
 easily. Iron construction. Thousands of these correct 
 desks are manufactured yearly in Lickroth's large School 
 Desk Works in the Palatinate. They are recommended 
 officially in Hesse. 
 
 (3) Vandenesctis desks. (Figs. XLIL, XLIII., XLIV.). 
 This model allows a more free position in sitting without 
 writing than those I have described. Each separate seat 
 revolves into minus distance in front and plus distance 
 behind and also revolves laterally. The mechanism is 
 shewn in Fig. XLIV. The manufacturer is Vandenesch 
 of Eupen, in the Aix-la-Chapelle district. 
 
 FIG. XLII. 
 
 (4) Hippaufs form (Fig. XLV.) can be brought 
 forward into nil-distance and back by means of iron 
 
SCHOOL DESKS. f 1 J 
 
 bands. The arrangement (patented) can be adopted with 
 any old-fashioned school form. 
 
 (5) Beyers form. A quite new, very cheap and very 
 well planned model by Beyer of Breslau, Government 
 Architect (Fig. XLVI.). The phrase simplex veri 
 sigillum may be applied to it. The side-boards or 
 cheeks, which support the seat of the form, have at 
 their lower end two elongated eyelet-holes of wrought 
 iron, through which runs a round iron rod. On this 
 
 FIG. XLIII. 
 
 rod the cheek slides backwards and forwards. The iron 
 rod is fastened by two iron angles screwed on to the 
 two cross-beams of the seat, so that the rod runs across 
 the form. The form moves without the least noise and 
 without any standing on the part of the scholars, simply 
 by their muscular power. Their thighs are stretched 
 forward in drawing the form up to the desk and in 
 pushing it back. In this way there can be a plus- 
 distance of 5 '6 inches [14 cm.] for standing and a 
 minus-distance of 1*2 inches [3 cm.], or more if desired, 
 for sitting. This sliding mechanism only raises the 
 price of a desk for five children by about 2s. 5d., and 
 since the inventor, from interest in the cause, has 
 
CHAPTER XI. 
 
 FIG. XLIV. 
 
 declined to take oui a patent, it can be affixed at very 
 little expense to any old-fashioned forms. 
 
 We see, then, that there 
 is no longer a lack of models, 
 excellent from a hygienic 
 point of view. It may be 
 left to the teachers to 
 choose from among them 
 that which appears the best 
 for teaching purposes. 
 
 Every manufactory has 
 now its tables of desk- 
 measurements suited, 
 according to the accepted 
 principles, for children of 
 all heights. They may be 
 seen in the prospectuses 
 of the School Desk Works 
 
 of Wolf and Weiss of Zurich, Lickroth of Frankenthal, 
 
 FIG. XLV. 
 
 Bahse and Hahndel of Chemnitz, Lenoir of Paris and 
 Vandenesch of Eupen. 
 
SCHOOL DESKS. 
 
 119 
 
 For scholars whose height varies from 3 feet 4 in. to 6 feet 
 [100 1 80 cm.], eight different sizes of desk are sufficient. 
 In order to fix some standard, I give here the 
 admirable Table of Measurements for flap dual desks 
 
 FIG. XLVI. 
 
 published after very careful discussion and observation 
 by the School Desk Commission of the town of Zurich. 
 (Cf. Die Schulbankfrage in Zurich. By A, Koller, Zurich, 
 1878.) 
 
120 
 
 CHAPTER XI. 
 
 
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SCHOOL DESKS. 121 
 
 In conclusion, I would point out that while the 
 scholars must sit badly in the old ill-constructed desks, 
 they may sit badly in the best of the new ones. Atten- 
 tion to attitude on the part of teacher and scholar 
 will be necessary with any desk. The main point is 
 that the eyes must not come too close to the work. 
 
 Unfortunately there are many teachers who require, even 
 in a writing lesson, that the scholar rise when called on. 
 If, to meet the demand of these teachers, desks with 
 positive distance are still brought into schools, and if, 
 moreover, on account of the teacher's order of merit 
 (a thing in itself very desirable) the children are not placed 
 in desks suited to their size, but big and little together 
 just according to their mental capacity, this shews an 
 unjustifiable depreciation of the efforts made by medical 
 men to prevent the increase of short sight. 
 
 If formerly Prussia was far behind other states with 
 reference to proper school desks, it is all the more 
 gratifying to find that a decree issued in Breslau, 27th 
 December, 1881, directed the attention of all magistrates, 
 district school inspectors, and town school-authorities to 
 the importance of minus distance in writing and 
 recommended the inexpensive contrivance of Hippauf, or 
 the desks made by Lickroth of Frankenthal, or those 
 made by Vandenesch of Eupen. This excellent decree 
 says: "To arouse the interest of local inspectors and 
 teachers in this important question, for the beneficial 
 solution of which they can often exercise a considerable 
 influence, we further resolve that in every General 
 Conference of Teachers held during the next year, the 
 school desk in relation to the health of the scholars, to 
 teaching and to school discipline, shall be thoroughly 
 discussed. . . . Lastly, we enact once for all that 
 in every case of the opening of a new school or the 
 re-furnishing of an existing school, a report shall in the 
 first instance be made to us, stating the kind of school 
 
122 CHAPTER XI. SCHOOL DESKS. 
 
 desks % proposed, and on what grounds the selection has 
 been made, in order that we may approve or reject the 
 selection before the desks are introduced." 
 
 Chairs and desks for University lecture rooms have 
 been for years adopted by Professors Samisch and 
 Forster ; but, as Koster truly observes, "The chairs 
 are all of equal height, and the students are not." 
 Professor Koster has accordingly, since the beginning 
 of his career in Bonn,* introduced into his lecture 
 room Viennese revolving stools, which the students, before 
 the lecture begins, can properly turn to suit their vetebral 
 column and their short sight. These seats, to be sure, 
 have no backs. 
 
 Just as important, of course, are good desks at home 
 as good desks in school. Many manufacturers produce 
 home desks, which can be altered in dimensions so as 
 to keep pace with the child's growth.! 
 
 But without any special desk, it is very easy to 
 make at home a proper seat for any child at any sort 
 of table, with the help of footstool and cushion, if we 
 only attend to these three main points : 
 
 (1) The seat must be of such a height that its 
 vertical distance from the table equals the distance of 
 the elbow from the seat-bones plus 2 inches [5 cm.]. 
 
 (2) The chair must be pushed so close up to the 
 table that the upper edge of the table overhangs by 
 2 inches [5 cm.] the fore edge of the chair. 
 
 (3) A footstool must, if necessary, be used, so placed 
 that the feet rest flat upon it while the knee is bent 
 at a right angle. 
 
 * Communicated by letter. 
 
 t Very good home desks may be had at Priebatsch's, Breslau (Ring 58.) Price 
 30 marks. 
 
CHAPTER XII. STRAIGHT-HOLDERS. 
 
 123 
 
 CHAPTER TWELFTH. 
 
 FIG. XLVII. 
 
 STRAIGHT- HOLDERS. 
 
 Quite recently school-desk reform which, on account of 
 expense, teachers and school authorities do not like to 
 see, has taken a completely new phase through the 
 invention of useful Straight-Holders. These at least 
 
 enable us in the case of old 
 schools to make the desks, with- 
 out altering them, somewhat less 
 hurtful to the scholars. 
 
 (i) So early as 1858 Schreiber 64 
 invented a straight-holder (Fig. 
 XLVII.). It consisted of a level 
 rod, fastened to a vertical bar of 
 iron or wood. The bar was 
 screwed on to the table in such 
 a manner that the rod was at 
 exactly the same heighth as the 
 child's collar bones. Whenever 
 the child stooped forward, the rod pressed him, and the 
 pain thus caused reminded him to sit up ! Such an 
 instrument of torture as this was unable to make its 
 way into use. 
 
 (2) In the Paris Exhibition of 1878 I found a desk 
 made by Happel of Antwerp, which had a so-called 
 straight-holder (Fig. XLVII I.). The edge of the table 
 was somewhat hollowed out into an oval, and in the 
 hollow was a wooden disk about 12*8 inches [32 cm.] 
 wide and 9-6 inches [24 cm.] high. The disk was hollow 
 in front, and was meant to receive the child's chest and 
 to prevent his leaning forward. Of course this apparatus 
 
FIG. XLVIII. 
 
 124 CHAPTER Xll. 
 
 merits the strongest condemnation ; for such a board 
 presses on the chest, and 
 pressure on the chest is 
 quite as mischievous as 
 stooping forward. 
 
 (3) In 1880 Dr. L, 
 Heffter and Theodor Schup- 
 pli of Zawiercie devised a real 
 support for the child. They 
 called it a Writing-Crutch 
 and took out a patent for 
 it. They have forwarded 
 four different samples to 
 me and have also published 
 a book of diagrams shew- 
 ing 45 different variations 
 of the "crutch." (Some of 
 these will be found in Fig. XLIX.) The inventors have 
 
 FIG. XLIX. 
 
 bestowed all imaginable ingenuity on perfecting the work- 
 ing of the mechanism ; and yet the crutches can hardly 
 
STRAIGHT-HOLDERS, 125 
 
 be recommended, not being designed on any right 
 principle. The crutch consists of a crossbar which is 
 placed close to the throat, under the chin. In this way 
 there is easily caused an unpleasant pressure against the 
 "Adam's apple," impeding the breathing. To escape 
 from this pressure the child pushes his chin about and 
 has difficulty in finding a position of rest, especially as 
 most of the crutch models have not the means of being 
 securely fastened to the table ; rather is the pressure of 
 the child's head relied on to hold the crutch to the 
 table by means of a bar which slants downward. In 
 but a few models there are sharp points fixed to the 
 lower end of the crutch, which are intended to be stuck 
 into the table. The crutches, which are made of wood 
 or metal, in course of time more or less gall the skin. 
 Only one model had a leather strap to be placed under 
 the chin. As far as my own experience goes, I find 
 that children cannot work for any considerable length of 
 time with these too unsteady crutches. 
 
 Dr. Heffter very rightly observes in a letter: "In 
 cases where any pain whatever prevents the application 
 of the crutch to the throat, cross pieces can be added 
 for the chin to rest in." 
 
 (4) This idea has been found 
 by Soennecken* of Bonn to be 
 the best for all children, whether 
 suffering in the throat or not. 
 He informed me in November, 
 1 88 1 that he had accordingly 
 acquired Heffter and Schuppli's 
 patent. H is Writing and Read- 
 ing Support (Fig. L.) is a true 
 chin-holder, made of wood in 
 different sizes and fastened in a slanting position to the 
 
 * Cf my address at the sitting of the Breslau Trades' Union, I4th November, 
 j882, I>reslauer ZeiUmo;, No. 823, and Schlesische Zeitung, No. 872. 
 
126 
 
 CHAPTER XII. 
 
 edge of the table by means of a simple but strong 
 steel spring. The mechanism for the supports, which 
 have to be placed at various heights, is very simple and 
 ingenious, but not sufficiently reliable to ensure that the 
 apparatus shall keep at the same height* Besides, the 
 pressure of the child's finger can easily push the movable 
 supports out of the proper height into a wrong height. 
 Many children, again, with tender skins complain that 
 the plate hurts their chin. I therefore prefer unalterable 
 supports, fixed at the proper height. But even these 
 fixed supports cannot be used in reading aloud, because 
 they move up and down with the lower jaw to the 
 great amusement of the children. Again, the support 
 does not compel the child to sit straight ; if he wishes 
 to lean down, he just pushes the little support on one 
 side. Nevertheless Soennecken's support, especially when 
 at the proper height, is much better than no support at 
 all ; in any case it reminds scholar and teacher about 
 attitude ; its price is remarkably low (from 3d. to is. 5d.) ; 
 and it might be greatly improved by coating the chin- 
 plate with india-rubber and in respect of fixture. 
 
 More recently still, 
 Kallmann, an optician in 
 Breslau, has succeeded in 
 making a very useful Face- 
 Rest (Fig. LI.) which can 
 be screwed on at various 
 heights to any table. It 
 has an iron ring enclosed 
 in india-rubber so as not 
 to hurt the face which V" %Jf^- 
 
 Mlthv 
 
 rests against it. (Thus l %v 
 
 supports have gradually 
 
 climbed from the chest to the collar-bones, the throat, 
 
 the chin and lastly the face). When once the Face-rest 
 
 * The newest models are mere salisfactory in this respect, 
 
 FIG. LI. 
 
\ STRAIGHT HOLDERS. 127 
 
 has been screwed on to the desk at the proper 
 height, the key can be kept by the teacher. I cannot 
 do without this rest in the case of children beginning 
 to write and read ; and / never allow my own children 
 to write without zV, whether at home or in school^ even 
 when sitting at the best possible desk. It does not cause 
 the least annoyance in writing ; the children soon grow 
 accustomed to it ; and even with old, wrongly-constructed 
 desks, that is with plus-distance, it is impossible for the 
 child to bend his head clown, even if he is more perched 
 than seated upon the form. The face-rest is, therefore, 
 a very valuable corrective to the old school desks. Of 
 course the apparatus must be screwed on at the proper 
 height. The introduction of this rest into schools and 
 private houses cannot be too strongly recommended. The 
 price* is certainly high but there should be a consider- 
 able reduction in price for schools. There is no doubt 
 that the right position of the child is better secured with 
 Kallmann's face-rest than with Soennecken's chin-support. 
 
 Both of these last mentioned straight-holders have been 
 recommended to the school authorities by the Prussian 
 Government in Frankfurt-on-the-Oder, Konigsberg and 
 Breslau, with an interest that deserves grateful mention. 
 The Royal Provincial School College at Breslau obtained 
 from the Royal Provincial Medical College a valuable 
 report, and forwarded it on the 3rd of November to the 
 directors of all the Silesian Schools. The report is dated 
 October 10, 1882 and says :t 
 
 "Soennecken's writing support is one of the artificial 
 aids to the prevention of a bad posture in writing and 
 therefore of the consequences of a bad posture, namely, 
 spinal curvature and short sight. We must first say 
 with regard to all these artificial aids that their effect 
 will be illusory if the school forms and desks and the 
 
 * It varies according to the mechanism of the screw from 2 to 6 marks, 
 t chlevische Leitung, Dec. I5th, 1882, Nr, 881, 
 
128 CHAPTER XII. 
 
 home writing-desk do not conform to sound hygienic 
 principles. But if the school desks and forms are rightly 
 made, a straight posture in writing will be attained with 
 more ease and security by a healthy adjustment of these 
 desks and forms than by any artificial supports, which 
 impede far too much the writers movements at the 
 school desk and which are soon felt to be a restraint, 
 and then after all do not effectually prevent a bad 
 posture of the head. But in cases where the school 
 desk is not properly constructed for writing or not 
 provided with a normal seat for writing and reading, 
 writing supports have their use and are not without 
 beneficial effect. .- Among these writing supports Soen- 
 necken's deserves a high place. It secures (to mention 
 its good points first) with tolerable certainty the position 
 of the head at the right distance from the copy-book. 
 This good effect is not completely attained, because, even 
 when the chin is resting upon the support, it is possible 
 to turn the head towards the left and bend it forward, 
 a movement which is always the beginning of a bad 
 writing attitude and one which is regularly adopted by 
 the children when, after writing for some time, they 
 begin to feel the chin irritated by the plate. Kallmann's 
 face-rest secures the position of the head at the right 
 distance somewhat better (though not perfectly) ; the top 
 part of it provides a much broader support which en- 
 circles the whole- forehead ; and the support does not gall, 
 so that it causes no change of posture. A very intelligent 
 teacher, Herr Doll, of Kreuzburg, has established this 
 fact by a series of experiments. A second great advan- 
 tage of Soennecken s writing support is its cheapness. 
 The non-adjustable writing supports, No. i, are sold 
 by the hundred at threepence each, and can therefore 
 be used for whole schools where wrongly made desks 
 are still in use ; that is, desks where the form is not 
 at the right horizontal interval (distance) and vertical 
 
STRAIGHT-HOLDERS. 
 
 interval (difference) from the desk. This is the point 
 in which Soennecken's writing support manifests a great 
 advantage over Kallmann's straight-holder. The latter 
 costs six shillings, and is therefore not adapted for use 
 throughout a whole school in a poor district, where 
 money cannot be raised to provide proper desks. Soen- 
 necken's writing supports, on the other hand, can be 
 procured by the poorest community for all its children ; 
 and then the serious evils resulting from the faulty 
 construction of desks are, at least in part, prevented. 
 This, therefore, is our final decision : Soennecken's writing 
 support is to be recommended for scholars and private 
 persons who are unable to procure the proper kind of 
 desks : Kallmann's face-rest attains the object desired 
 more surely than Soennecken's apparatus, because it 
 supports the head more completely and more comfort- 
 ably, but this advantage, in the case of schools, is at 
 least fully counter-balanced by the greater cheapness of 
 Soennecken'? writing support." 
 
 However much one may agree, on the whole, with 
 this admirable judgment of the Royal Medical College 
 there is one point open to objection. Even with a good 
 desk the straight-holder is not superfluous. I have seen 
 again and again that children have a tendency to stoop 
 forward, even at the most un-exceptionable desks ; while 
 with Kallmann's face-rest, they are compelled to sit in 
 a good position permanently. I especially recommend it 
 in the case of those desks which have, very properly, 
 a little reading slope at the far side. Then the face- 
 rest, which with Kunze's desk, when the leaf is drawn 
 out, is 20 24 inches [50 60 cm.] from the book, 
 compels the child to read from the book at that 
 distance and therefore with the minimum of accom- 
 modation-work and with head upright. The face- 
 rest w?ll certainly contribute to the prevention of short 
 sight. 
 
130 CHAPTER XII. STRAIGHT-HOLDERS. 
 
 The Report of the Royal Medical College, however, has 
 an important bearing on a wider subject than the question 
 of the face-rest. In asserting the pernicious effect of 
 positive distance between desk and form, it opposes with 
 all its scientific and official authority the fatal error of too 
 niggardly school-managing bodies who, as is unfortunately 
 the case in Breslau to this day, furnish even the newest 
 schools with desks injurious to health. 
 
 May this praiseworthy step on the part of the State 
 be the happy guarantee of a victorious battle against 
 short sight. 
 
CHAPTER XIII. DAYLIGHTING. 
 
 CHAPTER THIRTEENTH. 
 
 DAY LIGHTING OF SCHOOLROOMS. 
 It has been known for centuries that, the dimmer the 
 light, the nearer the eye must be to the page. It is 
 therefore a riddle why in the building of schools the 
 position, size and number of windows have not long ago 
 received that care which is so necessary in the interest 
 of good eyesight, and why we continually find authors 
 saying that this or that schoolroom " gives the impres- 
 sion of being most insufficiently supplied with daylight." 
 
 In my investigations in Breslau I have drawn up a 
 Light - Table for every schoolroom, based upon the 
 following questions. 
 
 How many windows are there at the right, left, front 
 and back of the writer? 
 
 How many windows facing east, west, north, south ? 
 
 Of what colour are the walls ? 
 
 How high are the opposite houses ? 
 
 How far off? 
 
 Of what height and width are the windows ? 
 
 In what storey is the room ? 
 
 I was obliged to content myself with these data, since 
 at that time there was unfortunately no photometer to 
 measure the degrees of daylight in somewhat the same 
 way in which we could measure heat, I observed, while 
 thus engaged,* that for comparing the lighting of 
 two rooms the human eye itself is in some cases the 
 best photometer. For example, a healthy eye, which 
 can read at a distance of 40 inches [i meter], will find 
 it difficult, although the daylight may be the same, to 
 
 * Cf. my Essay on the Examination of the Eyes of 10,060 School Children, 
 page 10 j. 1867. 
 
132 CHAPTER XIII. 
 
 read the same type at only 20 inches in a room lighted 
 by one small window. Since then, Von Hoffman 14 of 
 Wiesbaden has put this idea into practical shape by 
 advising that in every classroom Snellen's test types 
 be hung up, and lessons ended as soon as the day- 
 light is not strong enough to allow a healthy eye 
 to read type No. 6 (Fig. XIV.) at a distance of 20 feet 
 [6 meters]. This advice is well worth taking to heart* 
 
 The Strassburg Medical Report (Prof. Laqueur) would 
 like the daylighting to be such as to allow small diamond 
 type to be read with ease at 12 inches, even by the 
 scholar furthest away from the window. 
 
 Let us turn now to the separate points in my Light-Table. 
 
 i. Position of the windows with regard to the cardinal 
 points. Among 724 windows in 166 classrooms in 
 Breslau I found 171 facing east, 133 west, 210 north 
 and 210 south. At one time, therefore, people built 
 without the slightest reference to this matter. And yet 
 there can be no doubt that, other things being equal, 
 windows facing south admit more light into a room than 
 windows facing north. How greatly the degree of light 
 depends upon the position of the windows will be best 
 seen from the fact that a number of children in the 
 Zwinger Real School at Breslau, who could not dis- 
 tinguish my reading tests at 4 feet in a room facing 
 north, were well able to do so in a room facing south, 
 on the same floor, with windows of the same size and 
 with surroundings equally clear. 
 
 * While these sheets were in press I received the work of Bertin-Sans of Mont- 
 pellier : Le probleme de la Myopic Scolaire. (Annales d'hygiene publique, torn VII. 
 pages 46 ff. und 127 ff., 1882.) The author describes a school photometer similar 
 to Rumford's. A candle casts the shadow of a stick upon a screen ; as the candle 
 is removed further off the shadow gradually grows fainter and at last disappears 
 altogether. The lighter the room the sooner the shadow disappears. If it disappears 
 in one room when the candle is 8 inches [20 cm.] away ar.d in another when the 
 candle is 12 inches [30 cm.] away, the degrees of light in the two rooms will be as 
 8 2 :i2 a =4:9. Now, if broad daylight (grand jour) be taken as=i, since in 
 broad daylight the shadow disappears at I centimeter [| of an inch], the light in 
 the second room is to broad daylight as I 2 : 30* = i : 900. Prof. Berlin informs me by 
 letter that he is still personally occupied in improving his photometer. 
 
DAY LIGHTING OF SCHOOLROOMS. 133 
 
 > best aspect for windows is east or south. The 
 rays of the morning sun warm the room pleasantly ; 
 the wind seldom comes from the south-east in Germany; 
 and it is easy by means of blinds to protect one's-self 
 from too hot or too bright sunshine. Windows facing 
 west have this disadvantage, that the afternoon's school 
 work is too short for gaining the full benefit of them. 
 
 I adhere still to the opinion I expressed eighteen 
 years ago that there can never be too much light in a 
 school. Javal 65 also now fights for the freest possible 
 lighting. He says most truly : " The school must be 
 flooded with light, so that the darkest place in the class 
 may have light enough on a dark day." Most writers 
 are for windows looking east and south-east ; for instance, 
 Zwez 66 , Varrentrapp 67 , Falk 68 , Pappenheim 69 , Javal and 
 Baginsky 70 . Lang 71 and Reclam 72 alone prefer a north 
 aspect ; against which the fact that the rooms are then 
 more difficult to keep warm is an additional argument. 
 
 2. Number and size of the Windows. This point is 
 of the greatest importance. The fewer and smaller the 
 windows, the darker the room. I found windows only 
 42 inches high by 30 inches wide. I have proposed 
 that x for every square foot of floor there should be at 
 least 30 square inches of glass) that is, one square foot 
 of glass to every 5 square feet of floor. Rooms built 
 in accordance with this principle were found, cceteris 
 paribus, to be sufficiently lighted. Instead of this I 
 found in Breslau, I am sorry to say, schoolrooms with 
 i square foot of glass to 8, 10 or even more square 
 feet of floor. 
 
 On the other hand, I certainly saw rooms with i foot 
 of glass to 4 feet of floor, which were nevertheless 
 much darker than those mentioned above, owing to 
 high buildings outside which intercepted the light. 
 
 But how far, even at Exhibitions open to the world, 
 we fell short of hygienic wishes, was proved to me by 
 
134 CHAPTER xiit. 
 
 the measurements which I 73 took of the school buildings 
 at the Paris Exhibition in 1867. I found there: 
 
 In the Prussian schoolroom 167 inches (instead of 30) to i foot 
 of glass, 
 
 though in the American schoolroom 32-2 inches to i foot 
 of glass. 
 
 In the Vienna Exhibition of 1873 I found 62 to i foot of floor: 
 
 In the Portuguese schoolroom . . 17-6 inches of glass 
 
 American . . 20*6 
 
 Norkoping school . . . 257 
 
 an Austrian 26-5 
 
 Schon-Priesen school ... 28-6 
 
 only in the Swedish ... 32*0 
 
 and in the model of the Franklin ) R 
 
 school at Washington . . / " 
 
 No one can deny that there has been an improvement 
 of late. In the last Paris Exhibition 63 , 1878, I found 
 in the Ferrand School-house 60 square meters of glass 
 to 55 of floor, that is, about as much glass as floor. 
 This was the most excellently lighted schoolroom I 
 ever saw. 
 
 From Baginsky's 70 statistics we have the following 
 proportions : 
 
 Window Floor 
 surface. surface. 
 
 Catholic Publ. El. School, Frankfurt- A. -M. . i to 87 (Varrentrapp) 
 Middle School ' . i to 10 
 
 Higher Municipal School . i to 8-9 
 
 Jewish Real School i to 9.8 
 
 Crefeld Publ. El. School . . . . i to 5 (Buchner) 
 
 Berlin Schools i to 9, 8, 7 respectively (Falk). 
 
 The enactments of the Ministry of Education in Saxony, 
 April 3rd, 1873, make the ratio i to 6 and i to 5. 
 The Wiirttemburg decree of December 28th, 1870, i to 6 
 and i to 4. The Royal Technical Architect's Deputation 
 in Berlin, which accepted my minimum proposal, makes 
 the ratio i to 5. The Frankfurt Report says that the glass 
 should equal in area l /s of the room's longest side.* 
 
 * "The State," says Prof. Pfliiger24 very justly, "which asks a minimum of educational 
 results from the school, ought at any rate to prescribe a minimum ratio of window 
 surface to floor surface. A total disregard of this ratio is a great sin of omission 
 on the part of the State." 
 
DAY LIGHTING OF SCHOOLROOMS. 135 
 
 Of course only glass-space can be counted ; cross 
 wood-work and drapery cannot be included. Varrentrapp 67 
 complains that the want of light in the Frankfurt schools 
 is caused partly by the " beautiful" piers and partly by 
 architecture and solid wood-work which take up one-third 
 of the window space. In the Frankfurt schools the 
 window-space and glass are as 40 to 26, 24, 29. In 
 the new Magdalen Gymnasium at Breslau too much 
 room is usurped by wood-work. 
 
 Another point of importance in the lighting of rooms 
 is this : The piers between the windows should not be 
 rectangular but bevelled on the inside. The base of the 
 window, however, should not be bevelled, lest the light 
 fall too far below the desk and a troublesome reflexion 
 be caused. There must be at least 40 inches [i meter] 
 between the lowest edge of the window and the floor. 
 Would that windows were lengthened above instead of below ! 
 
 Erismann, in his latest work (School Hygiene, p. 49) 
 gives* the following scheme for the size and arrangement 
 of windows : 
 
 Length of wall : 
 
 Pier at one end of the room . . 5 feet 
 
 Four window recesses (at 5 feet) . 20 
 /Three piers between the windows 
 
 (at i foot) . . . . 3 
 
 Pier at the other end of the room . 3 ,, 4 inches. 
 
 Length of the room . 3 1 feet 4 inches. 
 
 Height of wall : 
 
 From floor to lowest edge of sill . 3 feet 
 
 Height of window recess . . . 10 8 inches. 
 Distance of highest part of window 
 
 from ceiling . i foot 4 inches. 
 
 Height of room . 15 feet. 
 The window itself would be 4 feet wide by 10 feet 
 
 * In meters. The meter is here taken as = 40 inches [Eng. Ed.] 
 
136 x/ CHAPTER XIII. 
 
 high, having therefore a surface of 40 square feet. 
 Four windows would thus have a surface of 160 square 
 feet. Supposing the room to be 23 feet 4 inches 
 wide, the glass surface would be to the floor surface 
 about as i to 4 a /2. 
 
 Just as insufficient lighting can do mischief, so can 
 perverse lighting. A. Weber 44 , in his admirable report to 
 the Hessian Ministry of Education, 1881, was the first 
 to draw attention to this point. The bad effect of 
 obliquely incident light can be inferred from the shading 
 of the eyes by the hat-brim or the hand. Weber shews 
 that " the delicate retinal picture does not come to 
 perception because, owing to the circles of diffusion, the 
 adjacent nerve-elements are, through interference, excited 
 almost as strongly, or even more strongly by the light 
 incident in all directions." He thinks also that the 
 incidence of light in all directions causes an immoderate 
 consumption of rhodopsine which (see Chap. II.), produced 
 by the retinal epithelium, fills the exterior parts of the 
 rods and so prepares the retina for the reception of the 
 picture. " The replacement of this rhodopsine requires 
 from 2 3 hours, according to the degree of its efface- 
 ment at the place of the retinal picture. Its accumulation 
 is intimately connected with the retina's power of 
 perception, although considerable, nay even organic 
 differences obtain here." 
 
 Dark eyes, in which the pigment-stratum is more fully 
 developed, enjoy a more energetic production of the 
 rhodopsine, and consequently a higher power of retinal 
 perception than eyes of a light colour. Weber con- 
 cludes from this that the eyes of children, which always 
 contain a smaller amount of pigment, are more quickly 
 exhausted by perverse lighting than those of adults. 
 
 According to Weber, another injurious effect of per- 
 verse lighting is the setting free of higher conditions of 
 refraction not corresponding to the distance of the object ; 
 
DAY LIGHTING OF SCHOOLROOMS. 137 
 
 for the contraction of the pupil caused by the increased 
 amount of incident light is accompanied by a correspond- 
 ing contraction of the accommodation muscle, a contraction 
 requiring that the object be brought nearer to the eye. 
 Another effect is that from i to 5 per cent, of the 
 school children suffer from spots on the cornea, and that 
 these children see much worse in a side light, which is 
 diffused at the spots and dispersed over the retina. (In 
 the year 1865 I found 211 school children out of 
 10,060, or 2 per cent., suffering from spots on the 
 cornea. ) 
 
 Of course no perverse lighting is possible when the 
 room has its light from above. The Strassburg Report 
 advises that, when the lowest edge of the window is less 
 than 40 inches (i meter) from the ground, the lower 
 panes should be covered with dark curtains or wooden 
 shutters. In my own opinion perverse lighting is never 
 so dangerous to the sight as too scanty lighting. 
 
 Kleiber 74 thinks it better to have three windows than 
 two, even if the two windows have just as much glass 
 as the three. For since the light decreases, not as the 
 distance, but as the square of the distance, the more 
 distant scholars receive less light from two windows than 
 from three. 
 
 The best plan seems to me to be that adopted in 
 photographers' or artists' studios, where the whole of the 
 left side of the room consists of windows separated from 
 each other only by small iron supports. This method 
 is easily carried out in one-storied buildings, as Ferrand 63 
 shewed in his model school-house in the Paris Exhibition 
 of 1878. 
 
 The lighting of the Microscopic Hall in the Patho- 
 logical and Anatomical Institute at Breslau is also 
 worthy of imitatipn. Three windows facing north, two 
 facing east, with total glass surface 23*20 square meters 
 to 62*64 square meters of floor, that is, i glass to 27 
 
138 CHAPTER XIII. 
 
 floor. There are no dark corners in the room. And 
 children who are learning to read and write need just 
 as much light as students learning the use of the micro- 
 scope. 
 
 3. The position of the windows with respect to the 
 writers must also be considered. Everybody knows that 
 he can best see to write when the light falls from 
 the left. If it comes from the right, the shadow of the 
 hand is thrown upon the paper, and the eye has to be 
 brought nearer to the paper. When I examined the 
 Breslau school children 18 years ago, I found 106 
 windows on the right of the desks, 62 in front, 93 
 behind and 463 on the left. In four rooms the only 
 windows were in front of the children or behind them. 
 In 43 rooms out of 166 there were windows on the 
 right, though there were only 3 rooms in which the 
 windows were exclusively on the right. This bad arrange- 
 ment was rectified in a few minutes by merely changing 
 the position of the desks. 
 
 Ellinger, 75 also, found in the physiological lecture 
 room in Wurzburg, in 1858, that the desks were 
 arranged for the light to fall from the right. " No 
 doubt," says Ellinger, " in this lecture room once a year 
 was expounded the well-known proposition about the in- 
 tensity of light and the square of the distance, and the 
 consequence was deduced that if the paper is thrown into 
 shadow a larger retinal picture is required, and therefore a 
 nearer approach of the eye to the paper, and that not in 
 simple but in duplicate ratio. It is easy to understand 
 that chronic myopia is developed by this means, and 
 that by such indifference young medical students 
 are not trained to discover the best light for 
 their own and, afterwards, for their patients' writing. 
 According to information obtained so recently as 1876 
 the desks in the physiological lecture room in Wurz- 
 burg were standing in the same position in which the 
 
DAY LIGHTING OF SCHOOLROOMS. 1 39 
 
 joiner had placed them 24 years before. In half-an-hour 
 and without any inconvenience the desks of students and 
 lecturer could have been turned round." Erismann found 
 a ^similar state of things in Petersburg. Blasius reported 
 in 32 per cent, of the school-rooms of the Duchy of 
 Brunswick a right-hand, and therefore, a faulty lighting. 
 
 When I found in Breslau in 1865 one - seventh 
 of all the windows to the right of the scholars, it 
 showed how little attention had been paid to the govern- 
 ment decree of the 24th ''of January, 1856, which ordered 
 that " the arrangement of the desks in the schoolroom 
 should be such that as far as possible the light may 
 fall from the scholars' left." Falk 68 found in the majority 
 of Berlin Schools, and afterwards Baginsky 70 found in 
 all the Berlin Schools, the windows on the scholars' left. 
 
 If the windows are only in front of the children, none 
 but those sitting on the first forms have sufficient light. 
 If there are windows to the left as well as in front, 
 the front windows certainly add to the amount of light 
 in the room, but they are troublesome, because the 
 scholars are dazzled by the front light when looking at 
 the black-board placed between or before the windows 
 and also because it is difficult, and often impossible, to 
 see what is written or drawn upon a board so placed. 
 
 Windows behind the desks are not injurious to the 
 children, provided that there are enough windows on the 
 left ; but (according to Thome 76 ) they dazzle the teacher 
 and make it difficult for him to superintend the class. 
 
 Until a short time ago most writers were inclined to 
 the opinion that the schoolroom should be lighted ex- 
 clusively from the left. Recently, however, the proposal 
 has again been made in France to light the room on 
 two sides, in order to give more light generally and 
 allow a better ventilation.* Such a schoolroom, designed 
 
 *Cf. the discussions which took place on this question in the Societe d'hygiene publique 
 at Paris between Trelat, Javal, Gariel and Laynaud. (Revue d'hygi&ne, 1879, p, 576 ff., 
 658 ff. and 102 1 ff.) 
 
140 CHAPTER XIII. 
 
 by Ferrand, we found in the Paris Exhibition of 1878. 
 He admitted the injurious effect of windows of equal 
 size on the right and left of the children, and therefore 
 adopted the " Eclairage bilateral avec intensites lumineuses 
 differentes " recommended by Dr. Galezowski of Paris. 
 To the left of the child was an immense window 10 
 meters [about 33 feet] high ; while to the right there 
 was a window, high up in the wall, 5 meters high. 
 The principal light thus came from the left ; there were 
 no cross lights on the desk, because the window on 
 the right hand extended downwards only 5 meters 
 (16^ feet) from the ceiling. The shadow fell from left 
 to right in writing, and yet there was on the whole 
 more light in the room than is obtained by one-sided 
 lighting. Javal also finds one-sided lighting insufficient 
 for large schoolrooms ; small rooms only 4 meters 
 (13^ feet) wide are sufficiently lighted, he considers, 
 by windows facing north. The Strassburg Report ad- 
 vocates windows on opposite sides only for large school- 
 rooms, in order to prevent the crowding of the scholars 
 towards the window side of the room and to obtain 
 more light in the room. 
 
 On the other hand, Erismann and Trelat unhesitat- 
 ingly pronounce light coming from the right to be 
 extremely injurious. I agree with them : for, while the 
 strongest contrast of black and white is desirable, 
 both in print and in hand-writing, a right-hand light 
 throws the shadow of the hand on the very spot at 
 which the eye has to be most keenly directed. 
 
 The ideal schoolroom, from an oculist's point of view 
 would have a glass roof. Roofs of this kind have long 
 existed in America. So far back as sixteen years ago, 
 I expressed a wish for this method of lighting (page 
 118 of my Untersuchungen) and since that time the 
 plan has been warmly approved for school-barracks by 
 Gross of Ellwangen, who has given drawings. He says, 
 
DAY LIGHTING OF SCHOOLROOMS. 14! 
 
 with perfect justice, that anyone who has been in a 
 modern weaving mill must be convinced that no dark 
 corner can exist in the most gigantic room which has a 
 glass roof.* Javal, too, considers a glass roof to be the 
 best, Of course, with glass roofing, schoolrooms could 
 have only one story, and in towns, where land is dear, 
 that would be scarcely possible. But the light should 
 come from above at least in rooms where drawing is 
 taught, and, according to Guillaume's? 8 advice, in rooms 
 where lessons are given in geography. Weber also desires 
 that girls' sewing lessons should be given in rooms so 
 lighted. These class rooms could all be placed in the 
 top story. 
 
 4. The surroundings of the School. It is self-evident 
 that the best position of windows with reference to the 
 cardinal points, the largest and broadest windows and 
 plenty of them are not enough for good lighting if the 
 outlook is blocked by trees or high neighbouring houses 
 or very high churches. Zwez 66 thinks that a house 
 opposite does not materially injure the school if the 
 angle of elevation, measured from a window-sill of the 
 school, does not exceed 20 or 25 degrees. Javal 65 
 demands with reason that the distance of the opposite 
 buildings should be equal to twice their height. 
 
 How our predecessors have sinned in this very matter 
 is shewn, among other instances, by the situation of the 
 Elizabeth and Magdalen Gymnasia in Breslau, which 
 were built centuries ago only 50 or 60 feet from the 
 highest church in the town and provided with very 
 narrow courtyards. But the entire re-building of the 
 Magdalen Gynmasium in 1867 upon the same site," and 
 without considering, at that date, that the church must 
 intercept the light from many of the class rooms, is one 
 
 * In Rosenthal's Weaving Mill, in Schweidnitz, I saw three rows of glass panes in 
 the roof, each of them i'66 meters high by 41 meters broad [about 5 feet 6 inches 
 by I foot 4 inches] : that is 204 square meters of glass to 768 square meters of 
 ftoor. The weaving mill was therefore lighted brilliantly. 
 
\ 
 
 142 CHAPTER XIII. 
 
 of the many inexplicable things which are met with in 
 practical school hygiene. 
 
 In comparing the lighting of the class-rooms with the 
 number of short-sighted children I found in 1865 that the 
 narrower the street in which the schoolroom was situated 
 the higher the opposite houses, and the lower the story on, 
 which the lessons were given, the more numerous the cases 
 of myopia among the elementary scholars. I purposely say 
 elementary scholars. This was a question, not of two or 
 three schools, but of 20, all having the same standard of 
 work for the children ; a question, therefore, not of a 
 freak of chance but of a law. Twenty elementary 
 schools of the same grade actually shewed differences of 
 from 1*8 to 15*1 per cent. M ; the ^/-number increasing 
 always with the narrowness of the street, so that the 
 new schools built in wide streets before the gates had 
 i '8 to 6 '6 per cent. M, while in the heart of the old 
 town, the schools buried in streets of " crushing 
 narrowness" had 7*4 to 15*1 per cent. M. This fact 
 deserves the attention of the authorities. It justifies the 
 conclusion that the darkening of the schoolrooms, caused 
 by the situation of the building, must have decidedly 
 contributed to the production and increase of myopia. 
 Indeed, in many of these rooms it is so dark that in 
 the winter the reading and writing lessons have to be 
 omitted both in the early morning and in the afternoon. 
 
 In higher schools I should not draw such a conclusion, 
 because the manifold home employment of the children 
 prevents us from making any such simple experiment as 
 in elementary schools, where but little is given in the 
 way of home lessons. 
 
 The removal of schools from narrow streets to open 
 squares and wide roads is urgently required ; and it is 
 generally advisable that for new schools such sites only 
 should be chosen as can never have the needful light 
 taken away by neighbouring buildings, 
 
DAY LIGHTING OF SCHOOLROOMS. 143 
 
 Those schools which cannot at once be removed 
 would be greatly improved by making more windows 
 and by broadening and lengthening the existing windows. 
 What the builder's art can do in this respect may be 
 seen by the huge shop windows which by means of 
 narrow iron supports have been easily made in some 
 of the oldest houses in the town. Why cannot this be 
 done just as easily in old schools. Where there's a will 
 there's a way. The new Director of the Elizabeth 
 Gymnasium has managed to enlarge the windows in his 
 darkest class rooms at least and to close some class- 
 rooms altogether. One class room (the Septima) of the 
 Elizabeth Gymnasium, situated on the ground floor ' in 
 the courtyard, was the darkest I ever saw. As early as 
 1865 its unhealthiness was unanimously acknowledged by 
 all teachers and medical men. This room was turned 
 into a teachers' library, though not till 14 years had 
 passed. 
 
 That a good day lighting in schools is of course not 
 the only point to be considered is plain. Just 39 of 
 Zittau, who found 80 per cent. M in the 2nd class of 
 a gymnasium, built so recently as 1871 and contain- 
 ing many well lighted rooms, lays the blame on the 
 number of home lessons which are often learned by very 
 poor light. This however should not prevent us from 
 trying to get the best possible light in our class rooms. 
 In respect of this matter, it is an important fact that 
 Florschutz 43 attributes the decrease of M in the Coburg 
 schools from 21 to 15 per cent, to the new "School- 
 Palaces" and that Seggel attributes the favourable results 
 in the Bavarian Military School partly to good lighting. 
 In this school he found an increase of only 14 per 
 cent, in M from the i3th to the igth year as compared 
 with 28 per cent, in the gymnasia. Seggel certainly 
 mentions as another cause of the improvement the wise 
 division of the working hours in the Military School, 
 
144 CHAPTER XIII. 
 
 where the hours for study are properly interrupted by 
 recreation and bodily exercises. 
 
 5. Blinds. Equally injurious with want of light is, 
 of course, direct bright sunshine. In our climate cloudy 
 days are on the whole far more frequent than sunny 
 ones. Sun light can easily be tempered by blinds, which 
 must of course be well arranged and kept in order. 
 The best colour for them is light grey, and the best 
 material linen. The Swedish school at the Vienna 
 Exhibition 62 was fitted up with blinds of fine yellowish 
 aspen laths as narrow as a penholder. These blinds 
 could be drawn up by a cord. They appeared to me 
 too apt to get out of order. An Austrian model school 
 exhibited by Schwab 79 at the same time was fitted up 
 with blinds of coarse unbleached linen ; but as the roller 
 was placed at the bottom and the blind drawn upwards 
 the whole window was obliged to be darkened if dis- 
 turbing sunlight came into the room only through the 
 upper part. 
 
 In an American school-house 62 in the Vienna Exhibi- 
 tion, I found a very thoughtful and practical arrangement. 
 The rods of the blind were in the middle of the 
 window. By four endless cords the blind could be 
 drawn from the middle of the window up or down, 
 the whole window could be shaded, and by moving the 
 rods up and down you could even regulate the lighting 
 at pleasure. This method of fixing blinds is the care 
 of a special company, the Chicago Curtain Fixture 
 Company. The blinds were of yellow waxed-cloth. 
 
 Weber 44 of Darmstadt thinks blinds altogether unprac- 
 tical because they cannot be used in rapid alternations 
 of sunshine and cloud ; he commends as the sole means 
 of regulating the light, and as admirable in another 
 respect, ground glass, which can be ground on one side 
 only and so superficially as to absorb scarcely any 
 light. 
 
^CAUFO* 
 DAY LIGHTING IN SCHOOLROOMS. 145 
 
 The Strassburg Report, however, condemns ground 
 glass as dazzling, and pronounces for roller blinds, which 
 no schoolroom is to be without. 
 
 6. The colour of the walls should be neither dazzling 
 nor dark. A light grey is most to be recommended. 
 
146 SUPPLEMENT fO CHAPTER 
 
 SUPPLEMENT TO THE THIRTEENTH 
 CHAPTER. 
 
 (FOR THE ENGLISH EDITION.) 
 
 PHOTOMETRY OF DAYLIGHT IN SCHOOLROOMS. 
 
 *In the year 1882 the Minister of Public Instruction 
 in France convoked a Committee, which investigated 
 very thoroughly the lighting of schoolrooms. The Com- 
 mittee dwelt especially upon this point, that as the 
 most essential light was that falling directly from the 
 sky upon the scholar's place, every scholar should be 
 in a position to see a piece of the sky, corresponding 
 in size to a window-space of at least 30 centimeters' 
 length, measured from the upper edge of the glass of 
 the upper window. According to my calculation, the 
 angle would then be about 3 at a place 20 feet [6 
 meters] from the window ; and that is, I believe, the 
 greatest width of an ordinary schoolroom at the present 
 time. 
 
 Forsterf wishes a minimum of 25 for the angle of 
 incidence at the scholar's place and also a minimum 
 of 5 for the "angle of aperture." "Angle of aperture" 
 is the name he gives to the angle subtended at the 
 scholar's place by the edge of the opposite roof and 
 the topmost edge of the window. 
 
 These proposals refer only to the angle of elevation 
 and angle of aperture in a vertical sense and leave 
 altogether unnoticed the width in which the light falls. 
 But it is obvious that this width must also have a 
 very important influence on the amount of daylight. 
 
 *Ministere de 1'InstrUetion Publique, Commission de hygiene scolaire. Paris, 
 Imprimerie Nationale, 1882. 
 
 t Vierteljahrschrift f. OffentL Gesundheitspflege, Bd. XVI. Heft 3, 1884, 
 
fcHOTOMfcTRY O^ DAYLIGHT IN SCHOOLROOMS. 
 
 The more unsatisfactory were the chemical and electrical 
 apparatuses previously used for measuring light, the greater 
 must have been the pleasure of hygienists at the appear- 
 ance in 1883 of the new and most ingenious photometer 
 invented by Dr. Leonhard Weber, Professor of Physics at 
 Breslau.* There is no doubt that this instrument is the 
 beginning of a new era in the science of school lighting. 
 (The apparatus may be purchased for 300 Marks [^15] 
 from Schmidt and Haensch, Stallschreiberstrasse 4, Berlin.) 
 By the help of this photometer the amount of light, 
 whether natural or artificial, at any scholar's place may 
 be determined in a minute. 
 
 Weber introduced as a standard of measurement the 
 " meter-candle" that is, the amount of brightness of a 
 paper held fully exposed to a normal candle i meter 
 distant. The normal candle is a candle of spermaceti 
 or stearine, of the size which has six to the pound. 
 It is therefore determined in any given case how many 
 normal candles must be burning with direct incidence 
 i meter from the place, in order to shed on that 
 place a light equal to that given at the moment in 
 question by the diffused light of day. 
 
 We are therefore no longer restricted to the use of 
 ordinary language in judging of the degree of light found 
 at any place, but are able to apply the touchstone of 
 number. 
 
 Weber's apparatus is constructed as follows, in all 
 essential particulars. (Fig. A.) In a fixed, horizontal 
 tube A is a normal light n_ (a benzine candle with a 
 fixed height of flame). This candle illuminates a sheet 
 of milk-like glass placed at a and movable within the 
 tube in a measurable way. In a second tube B which 
 is movable round the axis of A is a so-called reflection- 
 prism P, that is, a right-angled, three-sided piece of 
 
 * Central Zeitung fiir Optik u. Mechanik, 1883, No. 1 6 u. 17. See also Wiedemann's 
 Annalen der Physik, 1883. Bd. 20, p. 326. See also Electro-technische Zeitschrift, 
 April, 1884. 
 
148 
 
 SUPPLEMENT TO CHAPTER XIII. 
 
 glass ; there are also at b one or more sheets of glass, 
 and at d is a diaphragm which intercepts the rays of light 
 at the side of the tube. 
 
 FIG. A. 
 
 L. Weber s Photometer. 
 
 The prism P has the property of altering the direc- 
 tion of the rays of light which fall upon it from n, in 
 such a way as to cause them to be refracted upwards 
 to O (see the dotted line), so that an eye situated at 
 O would see the light n, not in the tube A, but below 
 in the tube B and behind b. 
 
 The light n cannot, however, be seen directly because 
 it is hidden by the milk-like glass plate a in the tube 
 A ; an eye, therefore, looking through O does not see 
 the light, but only sees at , by prismatic reflexion, 
 the glass plate a, illuminated by the light. 
 
PHOTOMETRY OF DAYLIGHT IN SCHOOLROOMS. 149 
 
 Now if the tube B is directed towards an illuminated 
 surface, such as a sheet of paper X, the observer, 
 looking in at O, perceives a field of vision cut by the 
 edge of the prism into two halves of equal size and of 
 the same shape, the left half illuminated by the paper 
 X and the right half by the light which has passecj 
 through a. By moving the glass plate a in the tube A y 
 and by introducing into the tube B at b plates of milk- 
 like glass (of which the light-obscuring power has been 
 accurately determined beforehand) an equal degree of 
 brightness is obtained in both parts of the field of 
 vision. 
 
 There is no difficulty in the case of artificial light ; 
 when, for instance, yellow gas light is to be compared 
 with yellow benzine light ; but it would be very 
 difficult indeed, almost impossible, to compare, as to 
 brightness of illumination, daylight with yellow benzine 
 light. 
 
 Here, again, Professor Weber comes to our aid. He 
 simply places before the eyepiece a piece of red glass, 
 which allows only red rays to pass through, so that 
 when the plate a has been moved to its proper place 
 (along the millimeter scale) both halves of the field of 
 vision appear not only equally bright, but of the same 
 colour ; and it is easy to tell whether two red surfaces 
 are equally bright. 
 
 By the help of this invaluable instrument we are 
 now able to say of any given surface, whether vertical, 
 oblique, or horizontal, towards which we can direct the tube 
 B, that this surface is as brightly illuminated as if 
 i, 2, 20, 100, &c. normal candles were shining directly 
 upon it at a distance of i meter. 
 
 I have very recently, by the direction of the Medical 
 Union, measured the daylight in 70 class-rooms of four 
 'High Schools at Breslau, my friend Professor Weber 
 frequently giving me his assistance, I selected two old, 
 
150 SUPPLEMENT TO CHAPTER XIII. 
 
 dark Gymnasia in the heart of the town, the Elizabeth 
 (), and the Magdalen (M) ; also the tolerably well- 
 lighted Johannes Gymnasium (J), and the new Catholic 
 Municipal School (C), which is well lighted in every 
 part. * The measurements were taken from 9 to 1 1 
 o'clock. In every class-room I chose the lightest place 
 at which a scholar could sit, namely i I 1 /* meters (40 
 to 50 inches) from the window, and also the darkest 
 place at which a scholar could sit, namely 5 6 meters 
 (200 to 240 inches) from the window. The measurements 
 were taken twice in every class-room, once on as clear 
 a morning as possible, and once on as dark and cloudy 
 a morning as possible. At times we found it necessary 
 to interrupt the measurements, owing to the alternations 
 of bright clouds and blue sky, which can in a few 
 minutes increase or decrease the degree of brightness by 
 100 candles or more. 
 
 The measurements are of course best performed on 
 days when the sky is uniformly clouded and on days 
 when the sky is perfectly cloudless and blue. 
 
 I found the following ranges of variation of the 
 brightness B : 
 
 At the best-lighted place for a scholar 
 
 In E on bright days 61 to 450 candles ; on dark days 47 to 235 candles. 
 M 82 720 2-6 182 
 
 / > ii 189,, 1172 121 1050 
 
 C 3 2 o Mio 79 555 
 
 At the darkest place for a scholar 
 
 In E on bright days 1*7 to 32 candles; on dark days <i to 22 candles. 
 ,, M 1*8 68 <i 10 
 
 / 7'9 J 33 n 3' 6 6 9 > 
 
 ,, C 21-6 160 4-6 38 
 
 The light diminishes with extraordinary rapidity as one 
 goes further from the window. It must not be supposed 
 that light from overhead is equally good everywhere. 
 
 * Compare my article on Daylight Measurements in Schools. Deutsch. med. 
 Wochenschr. No. 38, 1884. Also Compte rendu du Congres International Hygienicjue 
 a la Haye. 1884. 
 
PHOTOMETRY OF DAYLIGHT IN SCHOOLROOMS. 15! 
 
 In a large weaving mill in Schweidnitz I found under 
 a shed roof in different places 190 500 candles. We 
 can form a tolerable idea of the darkness in a school 
 from the candle-number on dull days for the best places. 
 In the Elizabeth and Magdalen Gymnasia the best 
 places in 25 classrooms had only a brightness of from 
 2 to 98 candles ; while in the Johannes School there 
 was not one class room in which the best place was 
 below 1 2 1 candles even in dull weather ; and in the 
 Municipal School there are only two classrooms with 
 places below 100 candles. 
 
 I found, I am sorry to say, in the Elizabeth and 
 Magdalen Gymnasia, 13 classrooms where on dull days 
 the brightness (B) is < i in the dark places. Here, 
 then, we have a number of children in fj classrooms, 
 writing at n o clock in the forenoon of dull days, by 
 less light than that of I candle. 
 
 Such figures as these must silence those persons who 
 come forward like Von Hippel* as opponents of state 
 school-doctors and instead of at once closing the schools 
 prefer to await improvement of the children's circumstances 
 from the gradual spread of hygienic principles. 
 
 The light of the sky can of course be also measured 
 with Weber's photometer. It is best to measure the 
 light of that piece of sky which directly illuminates the 
 scholar's place in question. This light of the sky (S) 
 I found to vary from 305 to 11,430 candles. There 
 were rapid changes from 11,430 to 6714, for instance, 
 when the blue sky was measured into the grey centre 
 of a white cloud near it. It is best, therefore, to choose 
 either uniformly dull days or uniformly bright days. 
 
 It is a good thing to reduce the number (} expressing 
 the brightness of any place to a normal sky of 1000 
 candles. The brightness thus reduced (Br) would be 
 
 * Rectoratesrede Giessen, 1884. "What measures are required owing to the frequent 
 occunence of short sight in Higher Schools?" 
 
152 SUPPLEMENT TO CHAPTER XIII. 
 
 for the best places in the Johannes Gymnasium = 76 645 
 candles and for the worst 2 27; in the Municipal 
 School for the best places, 91 368 and for the 
 worst 4 19. 
 
 Very important also is the reflexion from the opposite 
 houses (Bo). These are frequently brighter than the sky. 
 Opposite the Johannes School is a pale yellow house 
 which, when the sun was shining on it, showed a bright- 
 ness (0)=i866 candles, while ,S was only =1441. It is, 
 however, rarely possible to count on this reflected light. 
 
 A very simple method of determining provisionally the 
 degree of light in any classroom is to note the number 
 of scholars who from their places in the room can see 
 no sky at all. Among 68 classrooms I found 28 
 containing such places. 2461 scholars were questioned ; 
 459 f them could not see the least bit of sky ; 28 per 
 cent, in the Elizabeth, 24 per cent, in the Magdalen and 
 15 per cent, in the Johannes Gymnasium. In the 
 Municipal School there was hardly i per cent. In the 
 6th class of the Elizabeth Gymnasium so many as 80 
 per cent, could not see any sky. 
 
 It would be extremely difficult and would take up a 
 great deal of time to measure the piece of sky seen by 
 the scholar, if the measurements had to be taken with 
 the reflecting sextant. I therefore asked Professor L. 
 Weber to construct an instrument which should make it 
 possible to measure quickly the whole piece of sky visible. 
 Weber accordingly invented a most ingenious little 
 instrument, the Stereogoniometer, or Solid Angle Measurer. 
 (Fig. B.) 
 
 Imagine from a point C on an illuminated table-surface 
 all the bounding lines drawn which, skirting the edges 
 of the window or the roofs (where these are in the 
 
 * Described in the Zeitschrift fur Instrumenten-kunde, October, 1884. The instrument, 
 price 20 marks, may be obtained from Heidrich, Optician, Breslau (Schweidnitzer 
 Strasse 27) and from Schmidt and Hansch, Stallschreiber Strasse, Berlin, 
 
PHOTOMETRY OF DAYLIGHT IN SCHOOLROOMS. 153 
 
 way) of the opposite houses, strike directly against the 
 open sky. All these bounding lines enclose a solid 
 angle of which the apex is C. The contents of this 
 
 FIG. B. 
 
 L. Weber s Stereogoniowetar. 
 
 angle Weber calls the space-angle (&>). If, taking C as 
 the centre, a spherical surface of any given radius is 
 described, the space-angle will intercept a certain portion 
 of this spherical surface. 
 
 At the illuminated point C, then, we place a lens with 
 a focal length of 1 1 "4 centimeters. Behind the lens is 
 a paper ruled in squares, the side of each square 
 measuring 2 millimeters. Upon this paper is of course 
 cast an inverted picture of the piece of sky which can 
 be seen from the place. We outline this picture on the 
 paper. Every square in the figure thus obtained 
 corresponds to the unit taken as a standard in measuring 
 the space-angle, which unit is called a square degree. 
 (It may be noticed in passing that, if the whole vault 
 of heaven were so measured, it would contain about 
 41,253 square degrees.) 
 
154 SUPPLEMENT TO CHAPTER XIII. 
 
 With the help of the instrument drawn in Fig. B. we 
 can measure the space-angle <*> (expressed in square degrees) 
 and also the angle of elevation . 
 
 The ground plate G of the instrument is fixed 
 horizontally on the place to be examined by means 
 of screws and the plummet E which hangs down from 
 a suspender H attached to the plate P. The plate P t 
 which moves about a hinge, is placed so that the mark 
 m on it points to zero on the graduated arc B. The 
 plummet E should then be in a line with a point 
 marked on G. When the instrument is thus placed, a 
 point of light on a level with it would cast its image 
 through the lens L exactly upon a little pin c which is 
 fastened on the plate P. The side of the plate P 
 towards the lens is then covered with a sheet of paper 
 ruled in squares, each side of which measures 2 milli- 
 meters. The paper is held in its place partly by the 
 pin c and partly by some small brass springs. Now if 
 the focal length of the lens is so arranged that at a 
 distance from the lens of 114*6 millimeters a clear picture, 
 say of the sun's disc when on the horizon, would be 
 formed on the ruled paper, this picture falling on the 
 pin c, would be located exactly in a square millimeter ; 
 that is, the picture of a disc of four times the size, 
 equal therefore to a square degree, would occupy the 
 space of one of the little squares each side of which 
 measured 2 millimeters.* 
 
 The reading off of the mark m on the graduated arc 
 would give the angle a, which in this case = 0. If 
 the same bright disc stood higher in the sky, we should 
 turn the plate P until the picture fell again on c, and 
 the reading off of the mark m would now give a 
 different value from zero for the angle a. A piece of 
 
 * The diameter of the sun's disc occupies, accordirg to Dr. Cohn, about half an 
 ordinary degree, and therefore the sun occupies in the sky about # of a "square 
 degree." [Eng. Ed.]. 
 
PHOTOMETRY OF DAYLIGHT IN SCHOOLROOMS. 155 
 
 sky seen from the surface of a desk in a room, and 
 bounded irregularly by the crossbars of a window and 
 by opposite houses casts a correspondingly irregular 
 picture of itself on P. 
 
 If, then, we trace with a pencil the outlines of this 
 picture and count up the number of the squares whicli 
 the picture occupies, including fractional parts of squares, 
 we obtain directly in square degrees the space-angle 
 W corresponding to the size of the piece of sky seen 
 from the desk. 
 
 To facilitate the tracing, the ruled paper is fixed on 
 to a circular disc which can revolve round c. The 
 disc is so placed that the lines coincide as accurately as 
 possible with the contour of the window. 
 
 As to the simultaneous determining of a, strictly 
 speaking, a separate adjustment should be made for 
 each particular part of the sky-piece seen from the desk, 
 so as to make the picture fall exactly upon the 
 pin c in each case. But in practice it is quite 
 sufficient to seek for a mean angle of elevation a ; and 
 the simplest way of doing this is to turn the plate 
 P until the reflected picture of the sky-piece to be 
 measured is grouped as evenly as possible round c. 
 This can be done with sufficient accuracy by means 
 of the dividing lines on the paper. The reading off 
 of the mark m will then give the mean angle of 
 elevation. 
 
 The product &> sin a can then be taken as the reduced 
 space-angle and gives a number which, neglecting the 
 diffused light of the walls, may stand for the relative 
 measure of the brightness (B) of a place. 
 
 With this stereogoniometer I have measured all the 
 places which I had previously tested with the photometer. 
 I give here only the total numbers of classrooms in 
 which the angle w in well-lighted places was < 300 and 
 the number in which it was > 300, 
 
150 SUPPLEMENT TO CHAPTER XIII. 
 
 We thus find in the Elizabeth, Magdalen, Johannes 
 and Catholic Municipal Schools 
 
 E ii classrooms < 300 ; 6 classrooms > 300. 
 Mi2 8 
 
 J I ,, 16 
 
 *-' o * 3 
 
 But in the d#r/ places in 20 classrooms of the 
 Elizabeth and Magdalen Gymnasia was = o (!!). 
 This was the case in only one classroom of the 
 Johannes and in no classroom of the Catholic Municipal 
 School. 
 
 In a new village school in Marie- Hoffgen, near Breslau, 
 which stands in an open field without any houses 
 opposite and has 4 windows, the darkest place gave 
 = 1 1 6, much more, therefore, than the w of many of 
 the brightest places in the old town schools, which had 
 only o) = 40 to 70. 
 
 From the observations I have thus far made, I lay 
 down the following rule : The best place must not have 
 a space-angle of less than 500 ; and the worst place must 
 not have a space-angle of less than 50. 
 
 Of course o> is greater in the higher stories and 
 worst on the ground floor. The ground floor should 
 contain nothing but teachers' and school-servants' dwelling 
 rooms, the library, smaller cabinets and the aula which, 
 aula though so seldom used, is always found on the top 
 story with the best light. The classrooms should be as 
 high up as possible. 
 
 The reflected lights from the opposite houses and roofs 
 often increase the space-angle by 30 90 ; on the other 
 hand is often diminished even by as much as 24 by 
 the leaves of trees. 
 
 In places where o> was o the brightness in 20 
 classrooms varied on dull days from B < i to B = 3*4 ; 
 and on clear days from B = 17 to B = 8*5. This light, 
 then, is merely reflected from the walls, 
 
PHOTOMETRY OF DAYLIGHT IN SCHOOLROOMS. 157 
 
 Where <*> was < 20, B was mostly 2 5 and 
 in some cases so much as 19. 
 
 Where o> was 21 40, B was =3-3 3*5 candles on dark days. 
 41 60, B was = 1219 
 
 61 100, B was = 1038 
 
 As 10 candles should be the minimum brightness on dull 
 days, it follows that places with a space-angle less than 
 50 are not to be tolerated. 
 
 The cross-work of the windows has an enormous effect. 
 In many classrooms it took away 35 to 50 per cent, 
 from the space-angle. In future we must use slight 
 iron shafts instead of massive wooden cross-work. 
 
 The wide wall-spaces between the windows also darken 
 the room exceedingly. For instance, in the well-lighted 
 quarta (a) of the Magdalen Gymnasium at 40 inches 
 (i meter) from the window w was found to be 734 
 and B 400 candles, while at only a yard (0*9 meters) 
 from the window and behind the wall-space between 
 the windows was 62 and B = 10 candles. All 
 architectural adornments should therefore be avoided and 
 the windows should be as wide as possible and close 
 together like the windows of an artist's studio. 
 
 A great effect on the brightness in any room is 
 produced by the tarnishing and the opening of windows and 
 by double windows Of course for every desk the 
 greatest care must be taken that at no time shall a 
 house be built in front of it. 
 
 The measurements which show the loss of light by 
 blinds were most surprising. The ordinary grey dust- 
 blinds took away 87 89 of the light. White curtains, 
 drawn sideways, only took away 75 82. In my own 
 children's work-room I use the patent adjustable curtains 
 made by G. Weckmann in Hamburg. They are like 
 Venetian blinds, only that instead of laths made of wood 
 they have little frames covered with grey, transparent 
 stuff ; these can be placed vertically, obliquely or 
 
158 SUPPLEMENT TO CHAPTER kill. 
 
 horizontally. When vertical, they took away 91 at a 
 place 80 inches (2 meters) from the window ; when 
 oblique 70, and when horizontal only 57. They are 
 therefore much to be recommended. 
 
 The marquise blinds which always cover the topmost 
 part of the window are peculiarly injurious ; for it is 
 just this part of the window that gives the best sky- 
 light. All blinds used in school-rooms should be made 
 to draw sideways. 
 
 The colour of the walls is, of course, of the greatest 
 importance ; the smaller is the brighter the walls 
 must be. It is a great mistake to have the socle of 
 the walls painted dark. In the Magdalen and Elizabeth 
 Gymnasia there is a dark brown socle 80 to 1 60 inches 
 (1*5 to 2 meters) high! This accordingly absorbs what 
 little light falls into the room. It is also desirable, for 
 the sake of reflected light, that the dark overcoats, cloaks 
 and hats should not be kept in the schoolroom, but in 
 wardrobes, or hung up in an ante-room which can be 
 locked ; not to mention that remaining in a room where 
 50 70 cloaks, often wet or dusty, are hanging up is not 
 conducive to the health of scholars and teacher. 
 
 In rooms facing north there was found, cateris paribus, 
 less light than in rooms facing south. To gain more 
 light in old, dark schoolrooms Forster advises the placing 
 of large prisms before the windows. The prisms, he 
 says, will throw the light further into the room. The 
 practical experiment has not been tried as yet and might 
 fail, owing to the high price of large prisms. At Breslau, 
 however, at von Korn's book-shop there has existed for 
 some time an arrangement of movable mirrors such as 
 are used in England. By the aid of these mirror's the 
 light is greatly improved, the shop being situated in 
 the Marstall-gasse, which is only 3 meters wide (10 
 feet). The glass-maker Krahnert, in Breslau, makes these 
 large adjustable window-mirrors at from 40 to 45 marks 
 
PHOTOMETRY OK DAYLIGHT IN SCHOOLROOMS. 159 
 
 (40 to 45 shillings) per window. My measurement with the 
 photometer showed that a place 3 meters (10 feet) from 
 the window had without the mirror the light of 65 candles 
 and with the mirror the light of 130. Thus the light 
 was doubled. A place 6 meters from the window had 
 its light increased by the mirror from 12 candles to 20 
 candles. This simple and inexpensive apparatus may 
 therefore be recommended for old dark schools. But the 
 best of all would be to renounce all artificial expedients 
 and to get rid of the dark schoolrooms as quickly as 
 possible. 
 
 In the darkest place of every classroom those children 
 whose vision was the most acute were made to read No. i 
 of Jager's Types. In the Magdalen Gymnasium there 
 were 9 classrooms in which the type was recognised only 
 up to a distance of 15 25 centimeters. No such places 
 were found in the Johannes or in the Municipal School. 
 In these schools there were 12 classrooms where, even 
 in the darkest place, Jager's Type No. i was read fluently 
 at a distance of from 40 50 centimeters. Those places 
 at which a far-point of 30 centimeters was not 
 attained had on dark days less light than 10 candles. I 
 therefore fix B=io as the minimum of brightness. 
 
 These photometric experiments ought to be repeated 
 in every classroom. They could easily be made by the 
 teacher of physical science. 
 
l6o CHAPTER XIV. 
 
 CHAPTER FOURTEENTH. 
 
 ARTIFICIAL LIGHTING OF SCHOOLROOMS. 
 
 Artificial light is happily only required for a few 
 lessons in public schools ; but it is greatly to be wished 
 that afternoon school were altogether done away with. 
 In elementary schools this might easily be. In our old 
 school buildings the rooms are unfortunately so dark that 
 often on winter mornings gas is burnt for one or two 
 hours. All the schools which I examined 6 had gas. In 
 rooms with from 80 to 100 scholars I generally found 
 two, and never more than four flames. These few flames 
 were so badly arranged that a number of children had 
 the shadow of the body thrown upon the paper. This 
 obliged them to bring the eye much closer to the print 
 or writing and therefore might cause myopia. 
 
 The flames were in no single case provided with a shade, 
 so that, although the space above the scholars' heads was 
 brightly lighted, the light was not concentrated upon the 
 desk. Even in the University of Breslau in the year 1867 
 the lecture rooms had open flames only, and not until I 
 handed in my report upon the eyes of the Breslau 
 students 50 were shades and cylinders everywhere -#itro- 
 duced. Baginsky 70 found in the Berlin schools injclass 
 rooms for 40 scholars only four flames. 
 
 Authors' opinions differ widely as to the numl^ of 
 flames. I at one time proposed to allow one flanj ' to 
 every 16 children. Falk considered this numbetoo 
 liberal. Baginsky and Fankhauser 80 thought it insufficient. 
 The Saxon government ordered one flame to every 7 
 children. Emmert 27 wishes one flame, for " every 12 
 children seated at the new desks, which are further 
 
ARTIFICIAL LIGHTING OF SCHOOLROOMS. l6l 
 
 apart from each other than the old ones. Varrentrapp 
 requires with dual desks one flame for 4 children; Javal 
 a flame for each child. My latest observations lead me 
 to agree with Varrentrapp. 
 
 Open flames are wholly to be forbidden. The flickering, 
 the continual jerking movement of the gas stream, causes 
 a rapid alternation of brighter and fainter light and con- 
 sequently a hurtful intermittent excitation of the retina, 
 soon fatiguing the eyes. No flame should remain with- 
 out a cylinder. It would be a good thing, indeed, to 
 paralyse the many yellow rays of gas light with blue 
 cylinders, but these again would make the lighting less 
 bright. To concentrate the light upon the desks for 
 work, shades or, better still, porcelain plates or globes are 
 desirable. 
 
 Medical Councillor Gross 81 of Ellwangen has invented 
 a shade of his own. He writes, " I placed above a 
 hanging lamp a shallow curved shade made of tin. 
 This must be shaped like a segment of a sphere. Out- 
 side this shade is a second circular shade, in shape a 
 truncated cone of which the slope forms with the axis 
 an angle of 30. The upper edge of this ring-shade 
 hangs by three or four short supports to the outer 
 edge of the upper shade, so that it reflects the light 
 from the side and from above sideways and down- 
 wards. The shade should be lacquered a milky white 
 withj|a dash of blue in it. The dimensions are as 
 foll< 
 
 Diameter of upper shade . . . .15*5' 
 >epth . . ..1-5' 
 
 pper diameter of circular side shade . 15-5" 
 lower diameter ,, ,, . 21*5' 
 
 Depth of circular side shade . . .7" 
 Distance from point of burner (flat wick) 
 
 to centre of upper shade . . s"." 
 
1 62 CHAPTER XIV. ARTIFICIAL LIGHTING OF SCHOOLROOMS. 
 
 With this method of lighting, Gross, who is himself 
 extremely short-sighted, was able to work many whole 
 nights as easily as by day. 
 
 I 6 recommended, instead of fragile globes, tin shades 
 lacquered white inside and having with a height of 
 6" an upper opening of 36 sq. inches and a lower 
 opening of 324 sq. inches. Tin reflectors answer 
 very well in our Deaf and Dumb Institution ; they 
 are 16 inches [40 cm.] wide below, 4-8 inches 
 [12 cm.] high, and taper upwards to a width of 4 inches 
 [10 cm,]. It is only a short time ago that I was told in 
 a large institution that no new cylinders and globes 
 were procured as the scholars continually broke them. 
 
 The Strassburg Report considers that dull glass 
 globes absorb too much light and desires only cylinders 
 and tin reflectors, the flames being arranged in two rows 
 i meter (40 inches) above the heads of the scholars. 
 
 Where gas cannot be had which on account of its 
 cleanliness and greater brightness is certainly a good 
 means of school lighting petroleum should be used. 
 The lighting power of petroleum (according to A. Vogel) 
 is to that of gas as 87 : 100. Oil is not so desirable, 
 because its lighting power is to that of gas only as 
 63 : 100. On the other hand oil is Trei explosive, 
 
 Erismann 10 , who found in Petersburg among 397 
 boarders of Russian gymnasia 42 per cent. M against 
 only 35 per cent, among 918 day scholars, thinks Jthat 
 a cause of the greater percentage is the "too often 
 and badly arranged artificial lighting in the bo; 
 houses." Dor 36 also found in Lyon 33 per cent, 
 the boarders of the Lyceum and only 18 per 
 among the day scholars. 
 
 It is to be hoped that the electric light will^roon 
 banish gas from our schools, for the electric light is 
 attended with no danger of fire and does not poison 
 the air nor heat the room. 
 
SUPPLEMENT TO CHAPTER XIV. ARTIFICIAL LIGHTING. 163 
 
 SUPPLEMENT TO THE FOURTEENTH 
 CHAPTER. 
 
 (FOR THE ENGLISH EDITION.) 
 
 ARTIFICIAL LIGHTING OF SCHOOLROOMS. 
 
 With the aid of Weber's photometer we are now 
 happily in a position to express numerically the illumin- 
 ating power of lamp-globes, since we can now measure 
 the brightness at different places on a table lighted by 
 a flame of given height without any globe and can 
 measure how much the brightness at these places is 
 changed when various globes are placed over the flame. 
 
 This most important question, hitherto wholly unanswered, 
 I have recently undertaken to answer by means of more 
 than 500 measurements.* Only a few chief results can 
 be given here. 
 
 For gas circular burners we use tin shades polished 
 inside, tin shades lacquered white inside, milk-glass 
 globes, the so-called Paris shades, mica shades and 
 new-silver reflectors. The public usually call the milk- 
 glass globes porcelain globes. This is an error. There 
 are no porcelain globes ; they would be too costly, and 
 would absorb too much light. The only globes are of 
 glass, transparent, dulled or milky. The name " Paris 
 shdcfes" is given to those milky globes which have glass 
 plates under them. These plates may be either trans- 
 parent, dulled or milky. 
 
 It is very instructive, with reference to the lighting 
 of; Schoolrooms, to compare the polished with the 
 lacquered li-n shades. I took two tin shades of exactly 
 the same make, 46 centimeters in diameter below, 8 
 
 * H. Cohn. Untersuchungen iiber den Beleuchtungswerth clcr Lnmpenglocken. 
 Wiesbaden, 1885. Bergman n's Verlag. 
 
1 64 
 
 SUPPLEMENT TO CHAPTER XIV. 
 
 centimeters in diameter above and 9 centimeters high. 
 Inside, one of them was lacquered white, the other 
 polished. On placing them over a circular gas-burner 
 of 15 normal candles' power and i meter above the 
 table and taking measurements exactly under the burner (o) 
 and at from ^ a meter to 2 meters aside from it, I 
 found the following degrees of light (in meter-candles). 
 
 Meters aside from the flame 
 
 
 
 0-5 
 
 1 
 
 1-5 
 
 2 
 
 With no shade 
 With lacquered shade . 
 With polished shade . 
 
 1 
 9 
 64 
 
 3 
 9 
 15 
 
 4 
 6 
 6 
 
 2 
 2 
 2 
 
 1 
 1 
 
 1 
 
 (Decimals are omitted for the sake of simplicity.) 
 These figures shew at once the great gain of light 
 obtained with a polished shade ; and, as the lacquered 
 shade is also 6d. more in price, surely no one in future 
 will choose such for schools or work rooms. 
 
 The funnel-shaped milk-glass globes differ but slightly 
 from each other as to brightness, although they vary 
 somewhat in height. The figures quoted below suppose 
 in all cases a flame y^ of a meter above the table. 
 I found vertically below the globes about 30 candles' 
 light; at ^ a m eter aside 17 to 19; at i meter 
 aside 6 to 9 ; at \y 2 meters two candles' light. 
 
 The paper shades with mica give less light than the 
 milk-glass globes only 23 candles. The most light is 
 given by the new-silver hemispherical reflector, which 
 lights up a place vertically below the burner with the 
 power of 260 candles ! This reflector is to be recom- 
 mended when the brightest light is wanted on a small 
 space, for instance in shop windows ; but it is unfortunately 
 unfit to work by, because of the intolerable heat. 
 
 The lamp-plates under the Paris shades take away an 
 immense amount of light; the dull plates 33 per cent., 
 the milk-glass plates as much as 46 per cent., if the book 
 is Z a meter aside from the flame. 
 
ARTIFICIAL LIGHTING OF SCHOOLROOMS. 
 
 Far better are the so-called eye protectors, small 
 funnels which fit with their narrower end on to 
 the rim of the burner. There are glazed eye protectors 
 and eye protectors of milk-glass. The former, which 
 only have a thin glaze of milk-glass on the inside, are 
 the best. If they are 1^2 millimeters thick, they absorb 
 only 3 to 6 per cent, of the light ; but, if they are 
 two millimeters thick, they absorb from 13 to 20 per 
 cent. The milk-glass eye protectors, however, absorb 
 from 1 8 to 29 per cent. I prefer these thinly glazed pro- 
 tectors to glass cylinders dulled in .the lower part, since 
 the glazed protectors do not prevent us from using the 
 mica-cylinders, which are practically unbreakable. 
 
 Dull glass spherical globes, dull glass cups open at the 
 top and milk-glass cups open at the top injure the 
 lighting on all parts of the table. More light is 
 obtained when the burner is left altogether uncovered. 
 I found : 
 
 At side-distance . 
 
 0-5 
 
 1 
 
 1-5 
 
 2 
 
 2-5mtrs. 
 
 Without globe 
 
 11 
 
 6 
 
 3 
 
 2 
 
 1 
 
 With dull glass spherical globe 
 
 9 
 
 5 
 
 3 
 
 2 
 
 1 
 
 With milk-glass cup 
 
 5 
 
 3 
 
 1 
 
 1 
 
 1 
 
 With dull glass cup 
 
 10 
 
 4 
 
 2 
 
 1 
 
 1 
 
 With milk-glass cups, therefore, there is a loss of 
 from 40 60 per cent, of light on the table ; and yet 
 this kind of lighting is very common in places of public 
 resort (confectioners' restaurants). Another disadvantage 
 is that in the open cup the flame burns without any 
 cylinder, so that the continual flickering* makes reading 
 for any length of time impossible. 
 
 The albo-carbon light, as is well known, is obtained 
 by introducing napthaline vapour into ordinary gas. The 
 flame becomes by this means very white, and the 
 illuminating power of gas can be increased 1 4-fold. 
 Napthaline costs only one mark per kilogram and 
 improves the light greatly ; while, as the burner has 
 
1 66 
 
 SUPPLEMENT TO CHAPTER XIV. 
 
 only two little holes of the size of a pin's head, there 
 is a great saving of expensive gas. This method of 
 lighting, then, especially in conjunction with tin shades 
 is in every way to be recommended. 
 
 I have also tested photometrically 10 petroleum table 
 lamps with different burners. The best light was. thrown 
 upon the table by the Excelsior burner, the Sun burner 
 and the circular burner of the Hygienic Normal lamp 
 (Schuster and Bar, Berlin). 
 
 I found the following results. 
 
 
 WITH NO GLOBE. 
 
 WITH GLOBE. 
 
 Distance aside (in meters) . 
 
 0-25 
 
 0-25 
 
 0-5 
 
 0-75 
 
 1 
 
 1-25 
 
 1-5 
 
 Excelsior . . . 
 
 36 
 
 79 
 
 27 
 
 10 
 
 5 
 
 2 
 
 1 
 
 Sun . . ; . 
 
 23 
 
 65 
 
 25 
 
 7 
 
 4 
 
 2 
 
 1 
 
 Hygienic lamp 
 
 
 
 56 
 
 25 
 
 10 
 
 4 
 
 2 
 
 1 
 
 With petroleum lamps, tulip-shaped cups and spherical 
 globes are to be avoided for writing ; they give far less 
 light than funnel-shaped globes. 
 
 Among hanging lamps I recommend the Mitrail- 
 leuse hanging lamp made by Wesp of Frankfort-on 
 the-Main. I have used it for years in my children's 
 work - room. The Mitrailleuse has 16 wicks, which 
 certainly must be cut and trimmed very evenly, or the 
 lamp will smoke. It has a burner 10 millimeters in 
 diameter and a little plate like the Sun burner. . Above 
 it is a funnel-shaped milk-glass globe measuring in 
 diameter 9 cm. above, 29 cm. below and 14 cm. in 
 height. The flame is 65 millimeters high and, when 
 covered by the cylinder only, gives a light of 22 
 candles, or more than the best gas-flame. When 
 the lamp, with the globe, hung j a meter above 
 the table, the degree of light on the table at J^ 
 of a meter aside was 91 candles! At y 2 meter aside it 
 was 56 candles, and even at i*/ meters it was 4 candles. As 
 it gives at a distance of one meter all round a light 
 
ARTIFICIAL LIGHTING OF SCHOOLROOMS. 
 
 = 14 candles even when pushed up one meter above 
 the table, it deserves to be very highly recommended 
 for schools.* 
 
 (I may say in passing, that the new pianoforte lamps 
 with reflectors nickeled inside treble the light on the 
 music book.) 
 
 The best way to get an idea of the brightness at 
 different distances from an uncovered flame is to use 
 the following scheme invented by the ingenious Professor 
 Weber. (See Fig. C.) 
 
 FIG. C. 
 
 1= 100 Candles 
 
 Vertical 
 
 IM I/ 2 M 2M 
 
 The letter / denotes an intensity of light 
 100 candles. The horizontal lines are below the flame 
 at distances of *^, j, ^ and i meter ; the vertical 
 lines are at distances y 2 , i, i>, 2 and 2^ meters 
 aside from the flame. The number at each clot indicates 
 how many meter-candles would illuminate that place if 
 a light 100 candles were burning at /. For instance, 
 at a work-place one meter below the flame and one 
 meter aside from the flame the brightness would be 
 only 35 meter-candles. 
 
 * Later researches of Dr. Cohn ."give as the brightest hanging lamp for petroleum the 
 American 'lightning lamp,' (obtainable from Geo. Hermann, of Brieg, in Silesia). This 
 lamp has a three-fold air-supply and is constructed on the principle of fore-warming the 
 air. Hanging one meter above the table and provided with an albatrine shade, it 
 gives, at a point vertically below, 32 MC light, and 
 
 at distances aside (in meters) 
 MC 
 
 0-25 
 34 
 
 0-5 
 30 
 
 0'75 
 28 
 
 1- 
 
 28 
 
 3- 
 
 2-5 
 
 It therefore gives, even at a distance of one meter 
 as Wesp's Mitrailleuse." 
 
 all round, twice as much li^ht 
 
1 68 SUPPLEMENT TO CHAPTER XIV. 
 
 Now if the figures I have given in tables for the 
 different kinds of lamp-globes with 100 normal candles 
 are placed against the dots in the diagram, the amount 
 of light is obtained for every work-place. It is to be 
 wished and the wish will doubtless soon be fulfilled 
 that every lamp-maker and lamp-seller would give such 
 a diagram with every lamp-globe, so that it could be 
 known at once how much light should be expected at any 
 place. School authorities, at least, should henceforth make 
 a point of asking for this table whenever they buy lamps. 
 
 The question naturally forces itself upon us : How 
 many meter-candles, then, are desirable for reading and 
 writing ? 
 
 From experiments which I have made with reference to 
 this subject I find that a newspaper, printed in the so-called 
 bourgeois type, can be read at a distance of one meter 
 just as easily and quickly when illuminated by light equal 
 to 50 meter-candles as when read by good daylight. 
 
 Now a light power = 50 meter-candles can be obtained 
 from any stearine candle if the print is held only 14 
 centimeters from the flame. But who could work if so 
 close to the flame ? We have, however, a number of 
 globes which throw a light = 50 meter-candles, and even 
 more, upon the work-place, thus placing us in the 
 favourable conditions of day light. Lamp-globes, there- 
 fore, are important factors. 
 
 Now, if we reckon 50 candles as the best substitute 
 for day-light, we are asking nothing unreasonable when 
 we fix as the minimum of hygienic requirements the 
 fifth part of the amount' of light by which we can read 
 as quickly and as far off as by day. We ought, therefore, 
 not to approve the use of a flame and lamp-globe at so 
 great a distance that the paper s brightness is less than 
 10 meter-candles. 
 
 Anyone can convince himself by a simple experiment 
 that the degree of light = 10 meter candles is a very 
 
ARTIFICIAL LIGHTING OF SCHOOLROOMS. 169 
 
 moderate one. He has only to hold a sheet of paper 
 horizontally 15 centimeters below and 20 centimeters aside 
 from a stearine candle, and a light equal to that of 10 
 meter-candles will be cast on the point, thus determined, 
 of the paper. A brightness = i meter-candle is so little 
 as to make it scarcely possible to decipher a line of news- 
 paper print in a minute, while a healthy eye by 50 candles' 
 brightness, as by day light, can on an average distinctly 
 read 16 lines a minute at a distance of i meter. 
 
 If, then, we fix 10 candles as our minimum we 
 satisfy ourselves that, even at a side-distance of ^ of a 
 meter, none of the petroleum lamps in usje, except the 
 Mitrailleuse and the Hygienic Normal Lamp, can be ap- 
 proved of and, indeed, that the other petroleum lamps 
 give an available light only within a horizontal distance 
 of y 2 a meter. Thus, even with the best globes, gas and 
 petroleum flames should not be used for reading and 
 writing at a greater side-distance than y 2 a meter [20 
 inches].* 
 
 An abundant lighting for work- places in schools is certainly 
 of the highest importance for preventing myopia. Too bright 
 a light can always be moderated, but against too little 
 light there is no protection ; and I therefore entirely agree 
 with Javalt when he says: "il n'y a done jamais trop, 
 il n'y a jamais assez de lumiere artificielle." 
 
 The electric light has been falsely accused of dazzling 
 the eyes. It is of course hurtful to look directly at the 
 glowing charcoal points in an open electric bell-lamp. 
 Such an experiment is very foolhardy. But all lamps 
 should be so placed that the eye of the worker cannot 
 look into them. I have examined! the workmen in a sugar 
 refinery where for the last four years the electric light has 
 burnt with great intensity all night long. I found no 
 
 * See Note on p. 167. [Eng. Ed.] f Javal. Revue d' Hygiene, 1879, p. 1045. 
 
 t H. Cohn. Ueber Kiinstliche Beleuchtung. (A lecture given at Berlin, i8th March, 
 1883, at the loth meeting of the German Union for the Public Promotion of Health.) 
 Deutsche Vichteljahrschrtft f. offentl. Gesundheitspfl. xv, 4. 
 
I7O SUPPLEMENT TO CHAPTER XIV. 
 
 diseased eyes. I also asked whether the people would 
 prefer to go back to gas. They had no thought of so 
 doing. They were all perfectly satisfied. Poncet de Cluny, 
 (Progres medical, 1880, p. 627) also says very justly, 
 " There is an entire absence of clinical observations as 
 to the alleged dazzling by electric light ; all is limited 
 to a kind of legend" 
 
 On the contrary, we must plead all the more 
 earnestly for the introduction of the electric light into 
 schools because its effect both upon acuity of vision and 
 the power of recognising colours is much more favour- 
 able than that of gas. I have established this fact by 
 experiments, made for comparison, on 50 eyes of students 
 of Natural Science.* 
 
 Again, we must plead for the electric light as less 
 heating to the eye and the head than the light of gas 
 or petroleum. When lighting is too hot, the eye becomes 
 conscious of a feeling of dryness ; the moisture afforded 
 by the conjunctiva and covering the front part of the 
 eye evaporates too quickly. This is very troublesome, for 
 of course in this case not the eye only, but the head too, 
 becomes overheated, and headache sets in which finally 
 hinders work from proceeding. 
 
 There exist, as is well-known, in the spectrum, in 
 addition to the light-rays and beyond the colour red, the 
 ultra-red, or so-called dark, heat-rays. The heat of 
 these rays can be measured with blackened thermometers 
 and with thermometric columns. There were, hitherto, no 
 measurements for gas, petroleum and electric light. Now 
 I have proved* that, taking an Edison lamp of light- 
 power exactly 20 and a gas lamp with an Argand burner 
 of the same light-power and setting up a blackened 
 thermometer at a distance of 10 centimeters, the temper- 
 ature rose in 10 minutes about 12*8 with the electric 
 light, and about 23*5 with the gas light, above the 
 
 * Archiv. f, Augenheilkunde. VIII., p, 408, 1879. 
 
ARTIFICIAL LIGHTING OF SCHOOLROOMS. 17! 
 
 temperature of the room, which was 14. This ratio 
 i : 2 was also observed by means of a sensitive thermal 
 column. 
 
 It follows, then, that at a distance of 20 centimeters 
 gas-light produces twice as much heat as the electric glow- 
 light. At YZ a meter's distance from the electric light no 
 heat at all is felt, but at the same distance from the gas 
 light the degree of heat is very considerable. 
 
 Of course the heating effect of gas can be diminished 
 by placing the flame high enough above the head ; but 
 the brightness diminishes, not as the distance, but as the 
 square of the distance, and therefore twice or even four 
 times the amount of light is required if we wish to 
 avoid heat without diminishing brightness. All this is 
 however unnecessary with the electric light, which pro- 
 duces scarcely any heat. 
 
 An attempt has recently been made by Schuster and 
 Bar, lamp manufacturers, Prinzessinnen Strasse, Berlin, 
 to reduce the heat thrown out by the petroleum lamps. 
 They place above the flame, and one outside the other, 
 two cylinders between which the hot air passes upward. 
 The result is that the temperature falls at first about 
 2 ; but after awhile the outer cylinder also becomes 
 heated and the gain in coolness is only from ^ to i. 
 
 That the violet colour of the electric light is more 
 injurious to the eye than the yellow colour produced by 
 other lighting is a mere assertion supported by no 
 scientific observation. 
 
 The only defect of the electric light, its jerking, 
 has recently been obviated by improvement in the 
 mechanism by which the power is conveyed, so that 
 from an oculist's point of view the introduction of the 
 electric light into schools must needs be advocated with- 
 out qualification. 
 
172 CHAPTER XV. 
 
 CHAPTER FIFTEENTH. 
 
 - 
 
 HANDWRITING. 
 
 So early a writer as Fahrner 61a gave forth the weighty 
 sentence : " We let our children grow crooked in order 
 that their handwriting may be nicely slanted." Hermann 
 Meyer 82 of Zurich also pointed out that children seated 
 at bad desks turn their heads to the left (with which 
 movement begins the ruin of their attitude) in order to 
 follow more easily the course of the pen. Ellinger 75 of 
 Stuttgart says with truth that the reason why the children 
 sit so badly is that, with a slanting handwriting, the 
 paper, instead of lying just in front of the writer, is 
 pushed somewhat to the right. The muscles of the eyes 
 are then in a constrained position as they have to look 
 constantly downwards to the right and as the left eye 
 is further from the pen than the right. Now, if the 
 paper is just in front of the child's chest, the two 
 eyes are equidistant from the pen and the child 
 has only to look straight down. No group of muscles 
 is wearied by this, and the base-line of the eyes, that 
 is, the line joining the pivots of the two eyes, is 
 parallel to the lines of writing and not inclined to them 
 as it is when the paper is aslant. Gross 84 declares that the 
 children's 'vicious' attitude is essentially the consequence 
 (of the unnatural German handwriting and) of the position 
 prescribed for the copy-book. He observed quite cor- 
 rectly that the children sit straight so long as they are 
 making the strokes straight with which they begin their 
 writing course, but collapse as soon as they have to 
 make strokes slanting from right to left. He therefore 
 considers Greek print to be especially hurtful ; and he 
 
HANDWRITING. 
 
 173 
 
 was the first to recommend a more upright and rounded 
 handwriting. 
 
 The slanting German handwriting is not more than 
 70 years old ; before that time all writing was erect. 
 It was the calligrapher Heinrigs of Crefeld who first 
 introduced in 1809 an inclination of 45 for the German 
 alphabet. In order to establish uniformity among the 
 various styles of handwriting current in Germany, 
 Commissionsrath Henze offered in 1867 a prize for the 
 best national handwriting. No fewer than 754 com- 
 petitors presented themselves ; and by a majority of the 
 50 judges the prize was awarded to the alphabet of 
 Gosky of Cottbus, in which we already find several 
 curves substituted for angles. But the whole of this 
 prize-alphabet is sloped like its predecessors at an angle 
 of 45. (See Fig. LI I.) 
 
 FIG. LII. 
 
 There is no lack of official regulations as to the 
 position of the book and the hands in writing ; but they 
 often contradict each other. In the Prussian training 
 colleges the rule is that the left arm must be perfectly 
 horizontal ; the book must lie parallel to the edge of 
 
174 CHAPTER XV. 
 
 the table, the right hand must rest upon the third and 
 fourth fingers only and the wrist must be free. In the 
 Austrian training colleges, on the contrary, the rule is 
 that the upper left corner of the copy-book is to be slanted 
 downward to the left ; the right fore-arm is to rest on the 
 desk almost entirely ; and the left hand is only to touch 
 the desk in order to hold the paper in its place. 
 
 I satisfied myself in -an elementary School at Aussee 
 in Steiermark in the summer of 1880 that the stooping 
 forward of the head to the left with the book placed 
 horizontally is a necessary consequence of a slanting 
 handwriting. All the children sat perfectly upright when, 
 with the arm stretched out straight and the back against 
 the back-rest, they were ordered to write from dictation 
 and to make the letters vertical. But the whole 
 class fell forward as if by a stroke of magic when 
 ordered to write slantingly. In my opinion, therefore, 
 Gross is perfectly justified in advocating a kind of 
 rounded hand which is written with the pen held vertic- 
 ally and which is already appointed to be practised in 
 the upper classes of the Austrian elementary schools. 
 
 Dr. Schubert 83 of Nuremberg, in an essay well- worth 
 reading, has treated the question in a theoretical form. 
 He begins his investigation from the fact that the copy- 
 book may be placed before the writer in four positions. 
 (i) Erect central. (2) Erect dexter. (3) Oblique dexter. 
 (4) Oblique central. 
 
 ist, Erect central. In this position, as Schubert points 
 out, the eyes follow the slanting characters without an 
 undue effort ; but practically with this position a writing 
 which, slants down from the right is impossible. The 
 anatomical relations of the wrist do not allow the pen 
 to be so turned as to form letters slanting down from 
 right to left. 
 
 2nd, Erect dexter. This position is quite easy so far 
 as the act of writing is concerned. But, if the copy-book 
 
HANDWRITING. 175 
 
 is pushed four inches (10 cm.) to the right of the 
 writer's sagittal plane (which, as is well-known, divides 
 the head vertically into two halves, a right and a left), 
 the right eye must in the writing of a line describe an 
 arc l /5 greater than that described by the left eye. 
 This soon becomes intolerable. Besides this both eyes 
 are obliged to maintain a constant and maximum turning 
 to the right. Schubert calculates that at the beginning 
 of the line the left eye has to turn to the right about 
 27 and the right eye 15, while at the end of the 
 line the left eye has to turn 48 and the right 41. 
 Now the eyes' maximum inward turns and therefore 
 those of the left eye are 42 45, and the eyes' maxi- 
 mum outward turns and therefore those of the right 
 eye are 38 43. If, therefore, the copy-book is only 
 four inches to the right of the sagittal plane and the 
 body is upright, maximum achievements and in part 
 impossible achievements are demanded from the muscles 
 which turn the visual points of the two eyes to the 
 right. The child cannot keep up this muscular strain 
 for any long time. 
 
 If an attempt were made to relieve the fatigue by 
 turning the head, the head would have to be turned 
 through about 34 to the right. Now the maximum 
 turn of the neck-joint is only 45, so that the joint 
 would soon be weary and the child would help himself 
 by turning his body to the right. With this turn of 
 the body to the right, however, begins the well-known 
 collapse of attitude which soon ends in the unhealthy 
 approach of the eyes to the writing. 
 
 Moreover, as Schubert calculates, with this position of 
 the copy-book the right eye at the beginning of the line 
 is 2*3 centimeters [nearly an inch] nearer to the pen 
 than is the left eye ; in the middle of the line 3*6 
 centimeters [1*4 inches], and at the end of the line 4*2 
 centimeters [i'6S inches] nearer. This demands unequal 
 
176 CHAPTER XV. 
 
 accommodation, a thing frequently avoided by turning 
 first the head and afterwards the spine. 
 
 3rd, Oblique dexter. In this position the text-lines 
 slant upward from left to right. In addition to the 
 difficulties we have already explained with reference to 
 the erect dexter position, there is now that of following 
 the upward slanting lines by a rotatory movement of 
 the eyes with a horizontal base line. For, as the eyes 
 are turned upward towards the right in different degrees, 
 the vertical meridians must also be inclined towards 
 the right in different degrees. As the retinas, therefore, 
 no longer lie symmetrically, circles of diffusion must 
 arise at the outer edge of the field of vision. Just as 
 it is difficult to read for any long time with head erect 
 from a book in which the lines slant upward, it is difficult 
 to write for any long time with lines slanting in the 
 same way. Compensation is involuntarily sought by 
 turning the head towards the left shoulder until the base 
 line is parallel to the lines of the writing. And this 
 dreaded movement again inaugurates the collapse of 
 bodily attitude. 
 
 4th, Oblique central. This position of the copy book 
 unites the evils of the first and * third positions. Gross 
 recommends it and says that "only a slight inclination 
 of the head is required to obtain a natural position and 
 movement of both eyes." But it is just this inclination 
 of the head that begins the whole bad attitude. For 
 the reasons above given Schubert recommends the erect 
 central position with a writing more like round-hand and 
 having vertical down strokes. 
 
 Weber 14 also pronounces against the slanted hand- 
 writing because it requires that the point of the pen 
 shall keep exactly to certain lines of direction and limit- 
 ation. The child learning to write must watch the pen's 
 starting point, path and aim and must also guard 
 against any deviation from the line traced for him, 
 
HANDWRITING. 1 77 
 
 According to Weber, then, the work of the eye in 
 writing is not simply an act of gazing, but of taking 
 aim. Now, in taking aim with two eyes, the line joining 
 the two points of sight must be perpendicular to the 
 base-line. But, as the strokes of the letters slant upward 
 from left to right, the sagittal plane of the head must 
 be brought into the same direction, that is, both eyes must 
 aim, with the upstroke, from the ruled line to the pen- 
 point's aim and, with the downstroke, from the pen-point's 
 aim to the ruled line, while that part of the traced line which 
 is covered by the handle of the pen is more easily watched 
 from above. And therefore, according to Weber's observa- 
 tions, children, when writing carefully, do not turn the head 
 to the left, but turn the forehead down to the right and 
 look upward at an angle of about 30, just as if taking 
 aim with a gun in the direction of the pen-stroke. 
 
 On the other hand Weber found that with Soennecken's 
 round-hand pen the children could perform the writing 
 set them in an erect attitude while perfectly watching 
 the pen-point ; that a rounded-off tracing made possible 
 an exact correspondence of ends of the letters with the 
 ruled lines without any injurious approach of the eye to 
 the page ; and, lastly, that the rounded style of writing 
 could be written at least as quickly as the Latin. 
 
 Prof. Berlin has just confirmed Weber's statements by 
 exact measurements made in the case of 300 children 
 (von Grafe's Archiv. XXVIII. 2, page 258). He found 
 that with 93 per cent, of the children the base-line 
 was at right angles to the down-strokes. Nevertheless 
 researches about this question are not yet completely 
 ended. Further practical experiments are necessary. 
 
 I am indebted to the kindness of Professor Berlin of 
 Stuttgart for some additional and very important remarks 
 on children's handwriting, sent to me during the revision 
 of these pages. Prof. Berlin has together with Dr. 
 Rembold just published by order of the Ministry of 
 
178 CHAPTER XV. 
 
 the Interior and the Ministry of Education in Wurtem- 
 berg a very interesting and original work, " Inquiries 
 into the influence of Writing upon the Eye-sight and 
 the Bodily Attitude of School Children.* 
 
 I am sorry that I cannot now enter at length into the 
 details of this valuable work. But the final conclusion 
 must be noticed. Berlin and Rembold have convinced 
 themselves by numerous measurements that it is a 
 mistake to believe that the base-line is always parallel 
 to the ruled line of writing. Rather, the head is con- 
 stantly so turned that the base-line becomes perpendicular 
 to the down strokes. These investigators therefore recom- 
 mend that the slanting writing be retained, but with the 
 oblique central position of the copy-book. The Wiirtem- 
 berg Ministerial Commission agrees accordingly with the 
 following proposals of Berlin and Rembold. 
 
 1. The slope of the writing, that is, the angle which 
 the down-stroke makes with a line perpendicular to the 
 copy-book line, should be 30 40. 
 
 2. The copy-book should not be placed to one side, 
 but as nearly as possible exactly in front of the centre 
 of the body and so much askew that the line of its 
 lower margin slants upward from left to right at an 
 angle of 30 40. The proper position is known thus : 
 the direction of the down-strokes is perpendicular to the 
 edge of the desk, and the centre of the copy-book line 
 is as nearly as possible in front of the centre of the 
 body. 
 
 3. The upper part of the body is as nearly as 
 possible upright, so as to be supported by the spine. 
 Spinal fatigue is avoided by leaning the lower part of 
 the spine against a back-rest. 
 
 4. The horizontal axis of the body, or the line joining 
 the shoulders, is parallel to the edge of the desk ; and 
 
 * A Report to the Commission appointed to consider this subject, presented by Prof. 
 Berlin and Dr. Rembold of Stuttgart, Sept. 23, 1882, together with the united hygienic 
 proposals of the Commission. Stuttgart, 1883. 
 
HANDWRITING. 1 79 
 
 it is therefore an unjustifiable practice on the part of 
 some writing-masters to recommend to the pupil a skew 
 posture of the upper body in order to attain an elegant 
 slant handwriting. 
 
 5. The body does not press against the edge of the 
 desk, but keeps itself at a distance of about 1*2 inches 
 [3 cm.] from the desk. 
 
 6. The head, the cross-axis of which is also parallel 
 with the edge of the desk, is bent slightly towards 
 the table, and not further than is necessary for obtaining 
 a proper inclination of the line of sight to the desk. 
 
 7. The elbows are held somewhat lower than the 
 edge of the desk and equally distant sideways from the 
 body. The distance of the elbows from the body should 
 be neither too small nor too great ; but the elbow has 
 a certain amount of free space within which, while 
 hanging from the shoulder, it keeps clear of the desk's 
 edge. 
 
 8. The fore-arms, but not the elbows, are on the 
 desk and, as the copy book is to be in front of the 
 centre of the body, their position on the desk should 
 be almost symmetrical. 
 
 9. This attitude is to be retained throughout the 
 whole act of writing. The upper part of the body and 
 the symmetrically placed upper arms, from the shoulder 
 to the points at which the fore-arms rest upon the 
 desk's edge, should remain as unmoved as possible. 
 Only those parts of the body which are on the desk 
 should perform the writing movements. With reference 
 to these movements the following points should be 
 attended to : 
 
 (a) The movements necessary for forming the letters 
 and single words should be executed by means of the 
 finger-joints and the wrist-joint. 
 
 (b) In passing along the line, the right fore-arm, 
 while necessarily moving, should not quit its resting-point 
 
l8o CHAPTER XV. 
 
 at the desk's edge but, keeping that point as fixed as 
 possible, should revolve about it in such wise as to 
 describe an angle in the plane of the desk. The fore- 
 part of the hand would thus describe a plane arc of 
 which the copy-book line, slanting upward from left to 
 right, would be the chord. In order, therefore, to write 
 the copy book line straight, it is advisable that the 
 distance between the fore-part of the hand and the fore- 
 arm's point of support be slightly shortened, the amount of 
 shortening increasing gradually up to the centre of the line, 
 and gradually decreasing from the centre of the line to the 
 end. This shortening should be effected, not by 
 drawing back the fore-arm, but by slightly bending in 
 the joints of the hand and fingers. To facilitate the 
 observance of this rule it is advised, especially with 
 younger children, to see that the lines be not too 
 long. 
 
 (c) To begin a fresh line, the fore-arm has to reverse 
 with greater rapidity the slow revolution which it has 
 just made. As the bottom of the page is approached, 
 the distance between the fore-part of the hand and the 
 fore-arm's point of support is more and more shortened. 
 The shortening should be effected, not by drawing back 
 the fore-arm, but by bending in the joints of the hand 
 and fingers and, when this can no longer be done with 
 comfort, by pushing up the paper with the left hand 
 which is resting upon it. This movement of the left 
 hand must also be executed without displacing the left 
 fore-arm from its point of support at the desk's edge, 
 and therefore by means of the wrist-joint or a slight 
 turn of the left arm round its point of support. 
 
 10. The head also should, as far as possible, remain 
 in one position during the writing. The slight turning 
 of the head necessary for following the line from left 
 to right is attended with no injurious consequences even 
 with long lines. 
 
HANDWRITING. l8l 
 
 11. Steps should be taken for giving managers and 
 teachers sufficient insight into the necessity and import- 
 ance of these rules, so that they may with the requisite 
 purpose, strictness and energy set about putting them 
 in practice. 
 
 12. Reading and writing lessons, playing and working 
 with too minute objects, and near work generally, 
 should be forbidden in all Infant Schools, Kindergartens 
 &c., from which children frequently pass to higher 
 schools with short sight already begun. 
 
 13. During the first years at school writing lessons 
 should be restricted as much as possible. For this 
 purpose, at the beginning of school life reading only 
 should be practised, and this reading should be from 
 things at a distance (wall-sheets &c.). Then the child 
 should pass to reading from a book ; and lastly (not 
 before) he should begin to write the letters. Thus, in 
 the first school-years a writing lesson would not have 
 to be longer than half-an-hour, and the child should be 
 made to leave off every five or ten minutes for a few 
 minutes' rest. 
 
 14. The first writing lessons should aim at having 
 the letter-forms made as large as possible, and should 
 be less concerned with their evenness and accuracy, even 
 if the standard of good penmanship had to be lowered 
 in consequence. 
 
 15. From the net-work of lines on slates and black- 
 boards all slanting lines of direction should be removed. 
 
 1 6. Generally, writing when under instruction should 
 be curtailed as much as possible, and in particular 
 there should be as little as possible of writing in home 
 lessons. This last should only be allowed when the 
 home provides the necessary space and the necessary 
 light. 
 
 17. If it is impossible to do away altogether with 
 written home-work, the teacher, by giving the children 
 
1 82 CHAPTER XV. 
 
 repeated instruction on the point, must do his best 
 to make them observe in their writing at home the 
 proper position and attitude. It is moreover greatly to 
 be desired that the parents also should receive instruc- 
 tion on this subject." 
 
 Laqueur considers writing generally less injurious than 
 reading. He thinks that the reason for slanting hand- 
 writing is the greater ease, from the more extended 
 range, of the curved movements, but that in vertical 
 writing the position of the hand is a constrained one. 
 
 In my opinion Kallmann's face-rest will always be of 
 great use in writing, for I have convinced myself that, 
 whatever may be the position of the child's copy-book, 
 the turning of the head required for it does not affect 
 the position as a whole as soon as the head finds at 
 the face-rest its proper permanent support. 
 
 Gross, Javal and Weber believe that it is the German 
 alphabet that is especially hurtful to the eyes. Javal 
 even asserts that, if the number of myopes appears to 
 have increasd in Alsace since the annexation (no such 
 statistical result is at all known to me), the German 
 characters are a cause of it. Weber finds that the 
 almost total absence of hair-strokes and the easy curves 
 of the letters make the Latin alphabet preferable and 
 that it requires far less visual effort to keep the bends 
 of the Latin letters on the lines, because these bends 
 are not angular as in the German letters, but rounded, 
 so that what has to be achieved is not the coincidence 
 of a point but of a line. Weber says, moreover, that he 
 has satisfied himself experimentally that a child of eight 
 years who has learnt Latin writing for three months 
 and German writing for two years is always somewhat 
 less advanced in the latter. 
 
 I can from my own experience affirm that the Latin 
 hand is written more quickly than the German ; but 
 I do not think that the German writing has been 
 
HANDWRITING. 183 
 
 proved to be injurious. It is, however, in general desir- 
 able that our younger school children should not be 
 tormented with two alphabets at once but, as in almost 
 all other educated states, should be taught only the 
 Latin character. 
 
 I entirely agree with School-director Dr. O. Sommer 
 of Brunswick who, in his Easter programme 1883, re- 
 commends a steeper handwriting (75 with a somewhat 
 oblique central position of the copy-book) and concludes 
 with the following words his essay, well worthy of 
 attention, " On the Writing Question:" "If it were in 
 our power we would once for all throw overboard the 
 whole so-called German handwriting and confine our- 
 selves to the so-called Latin handwriting, in order to 
 be able to effect at once a great diminution of the 
 reading and writing lessons in the lower classes. When 
 shall we at last be set free from this unhappy gift of the 
 middle ages ? " 
 
1 84 CHAPTER XVt. 
 
 CHAPTER SIXTEENTH. 
 
 SLATES AND BLACKBOARDS. 
 
 "As for slates, they are at any rate a very inexpensive 
 material but, since the strokes made on them are seen as 
 bright grey on a dark grey ground, the contrast of colour 
 is so slight that the use of slates is trying to the eye. 
 It is to be wished that some material better in this 
 respect were discovered." 
 
 This wish, expressed by me as long ago as 1867 
 (cf. " Examination of the eyes of 10,060 School Children"), 
 has only just been fulfilled. A fresh impulse was given to 
 the matter by Prof. Horner.* In 1878 he published, at 
 the request of the educational authorities of Zurich, 
 comparative measurements of acuity of vision as tested 
 with letters of the same size, seen under the same 
 degree of light and written with slate pencil, lead pencil 
 and pen respectively. 
 
 It was to be expected that white letters on a dark 
 ground would, owing to irradiation, be legible at a 
 greater distance than black letters on a white ground. 
 And this holds good for white dots on a black ground. 
 Some years ago I stated that several of my colleagues 
 were able to count black dots on a white ground up to 
 distances of 16, 26 and 50 feet, while they could count 
 white dots of the same size on a black ground up to 
 22, 34 and 57 feet respectively. 
 
 But dots and letters are not the same thing. Horner 
 found that irradiation actually increased the difficulty of 
 reading bright letters at a great distance. With E and 
 B for instance, the dark inter-spaces are covered by the 
 bright lines and thus the letters suffer in legibility. 
 
 * Deutsche Vierteljahrschr. f. off. Gesundheitspfloge. Bd. X. Heft 4. 1878, 
 
SLATES AND BLACKBOARDS. I 5 
 
 Of course legibility is still further diminished when the 
 letter is grey instead of a good white. The letters B 
 and E were recognised as follows : 
 
 Black on white up to 496 cm. 
 White on black ,, 421 
 Grey on black ,, 330 ,, 
 
 We must also remember the shining reflection of slates 
 which, as Horner aptly says, is of itself enough to 
 banish them from the school, since it is a chief cause 
 of bad attitude. 
 
 But, even when this reflection was avoided, Horner 
 found that the same letters were recognised as follows : 
 
 ON A CLEAR DAY : ON A DULLER DAY : 
 
 With Ink up to 211 cm. . . 178 cm. 
 Lead Pencil ,, 183 . . 149 ,, 
 
 Slate Pencil 159 . . 132 
 The ratio, therefore, of slate pencil writing to lead 
 pencil writing was 7:8; and the ratio of lead pencil 
 writing to pen and ink writing was the same : while 
 the ratio of slate writing to pen and ink writing was 
 
 3-4- 
 
 Accordingly, an eye which can read ink letters at 30 
 
 cm. [12 inches] must be only 22 cm. [about 9 inches] 
 distant in order to read letters of the same size 
 written with a slate pencil. 
 
 Now in the first stage of learning every centimeter 
 is of consequence ; and therefore Horner was perfectly 
 justified in summing up thus : " The hygiene of the eye 
 demands the banishment of slates and black-boards from 
 our schools and the use of pen and ink in their place. 
 Compliance with this demand will do something to diminish 
 the danger of short sight, a danger which becomes 
 more and more menacing to each successive generation." 
 
 What verdict did the Swiss teachers give on this ? * 
 Some teachers, who had from the first adopted pen and 
 
 * Deutsche Vierteljahrschr, f. dffentl. Gesundheitspflege. Bd, XII. S. 332. 1880. 
 
1 86 CHAPTER XVI. 
 
 ink for their beginners, found educational advantages in 
 so doing. They held that there was an end to the 
 clatter of slates, that the children sat up better because 
 they could more easily read what they had written 
 with ink, that there was more order and cleanliness 
 because the children could no longer rub out mistakes ; 
 the teacher, too, could with a copy-book better control 
 the scholar's progress. The change certainly increased 
 the work of the teacher, but that was a matter of 
 minor importance, for in any case the transition at a 
 later date from slate to paper was difficult ; by constantly 
 using the hard and quickly used up slate pencil, which 
 wrote equally badly however held, the child's hand 
 became stiff, and thus the penholder was twisted in all 
 directions. All this was avoided by using* pen and ink 
 from the first. 
 
 But this opinion was not accepted by the Congress 
 of all the elementary teachers of Zurich after the 
 experiment of using nothing but pen and ink in the local 
 schools had been tried from May 1877 to February 1879. 
 The teachers did not fully agree with Horner, because 
 the scholars were never allowed to write on slates for 
 long together, indeed never for half-an-hour without 
 intermission. They thought that one should pass from 
 the easy to the difficult, and the use of the pen was, 
 unquestionably, attended with great difficulty. Now the 
 children had to be occupied in their very first days at 
 school an easy matter with a slate but not with a pen. 
 Therefore they thought that the transition to the pen 
 should not take place till the small letters had been 
 mastered. The children sat just as badly over a slate 
 as over a copy-book if the teacher did not give 
 regular attention to their attitude. 
 
 Hereupon the Schuldirection of Zurich decreed as 
 follows on May 3rd, 1879. "Pen and paper are 
 to be considered as essentially the writing materials, 
 
SLATES AND BLACKBOARDS. 187 
 
 The use of slates is, however, left to the discretion of 
 the teacher with this condition, that at the beginning 
 of the winter half-year pen and paper shall begin to be 
 chiefly used." 
 
 Until recently I agreed with Horner, if only for this 
 reason, that as the contrast of ink and paper is stronger 
 than that of slate pencil and slate, the words written 
 must be clearer on paper than on slate. 
 
 But, more recently, a great improvement in slates 
 has been discovered, so that the medical man will now 
 be able to meet the teachers' wishes, which no doubt 
 have justice in them. 
 
 Herr Emanuel Thieben, a manufacturer of Pilsen, has 
 in fact succeeded in the attempt to replace slates by white 
 tablets of ^artificial stone. These tablets can be written 
 upon with a special pencil, and the writing can be 
 rubbed out with a sponge without leaving a trace.* A 
 dark-brown pencil was at first used, but a blacker one 
 is to be substituted. A special ink may also be used 
 instead of pencil and can easily be effaced and the 
 tablet thoroughly cleansed with soap. 
 
 I experimented with ten grown - up persons, good 
 observers, and I. found that letters of the same size 
 with the same light could be read on the slate at an 
 average distance of 5 meters [16^ feet] and on the 
 white tablets at 6 meters [20 feet]. 
 
 I have, lately, with Rector Dr. Carstadt, examined 100 
 scholars of the Sexta and Quinta in the Higher Municipal 
 Evangelical School of Breslau.t A preliminary examina- 
 tion with Snellen's printed^ test types had resulted, by 
 the way, in the sad discovery that of these 100 boys, 
 from 10 to 12 years old, only 55 were emmetropic. 
 
 * Price of tablet 20 to 30 kreuzers [2d. to 3d.]. (Import duty into Germany 3 marks 
 per ioo kilograrus.) The inventor will, however, shortly offer them at the same price as 
 slates. 
 
 t Centralblatt "fiir Augenheilkunde. 1882. Nov. -Heft. 
 
l88 CHAPTER XVI. 
 
 These 55 emmetropic boys, then, were made to read 
 from a distance a number of letters, very carefully drawn 
 on the slate and the stone tablet after Nos. 6, 5 and 4 of 
 Snellen's types. 16 scholars read them at an equal 
 distance, though always rather more slowly and hesitat- 
 ingly on the dark slate than on the white tablet. The 
 other 39 read them at a greater distance on the tablet 
 than on the slate. In some cases the distance was con- 
 siderably greater. 
 
 If I call the distance at which the letters were read 
 on the slate 100, the distances for the white tablet are 
 as follows : 
 
 10 children read up to 107, 108, 109. 
 12 114, 116, 120. 
 
 8 122, 125, 129, 130. 
 
 9 i . r 33> !37> I43> J 44 and 150. 
 The average ratio for all the 55 observations was 
 
 100 : 116 = about 7:8. Writing which can be easily 
 read on the white tablet up to 30 centimeters [12 inches] 
 requires, therefore, when written on a slate, to have the 
 distance reduced to 26 cm. [10*4 inches]. Now as I 
 have urged above in preventing myopia with young 
 beginners, every centimeter is of importance. 
 
 There is no doubt that, from an oculist ' s point of view, 
 Thiebens white tablets deserve the preference over slates> 
 especially as they are wholly free from shine. 
 
 Weber differs strongly from Prof. Horner's opinion. 
 He says that the difficulty, exertion and mischief of 
 writing between lines and with lines of direction are 
 just the same whether slate pencil, lead pencil or pen 
 be used. Nevertheless, Weber now recommends, as a 
 substitute for slates, white cardboard tablets made by 
 Biirchl of Worms. One kind of these tablets, written 
 on with charcoal, is in fact excellent, as every mark 
 can be rubbed out dry with German tinder. The 
 
SLATES AND BLACKBOARDS. 189 
 
 other kind,* with which lead pencil is used, I do not 
 recommend, because it must be cleaned with a wet 
 sponge. This softens the tablet and makes the writing- 
 surface blistered and uneven. 
 
 The Strassburg Report considers the slate-question 
 generally as of little importance, on the ground that 
 there is no danger of short sight with such young 
 children. I am still inclined, however, to lay great 
 stress upon the point, my experience with the A, B, C 
 regiment having taught me that making these young 
 children work with slates, on which it is difficult to see 
 the marks, is just the thing that very quickly .has such 
 an effect on their attitude that, later on, when they 
 write with pen and ink, they have lost the power of 
 sitting straight. 
 
 Another point of great importance for the hygiene of 
 the eye is the use of a good teacher s tablet. This 
 ^hould be of a good black, but free from shine. 
 Wooden blackboards, whether lacquered or polished, are 
 not to be tolerated. Weber and Horner accordingly 
 desire that a huge slate should be let into the wall 
 by the teacher's desk. If the rearmost forms are 
 9 meters [30 feet] from the slate, the figures written 
 upon it should be, according to Horner,! even with 
 the best light 4 cm. long [r6 inches] and very thick. 
 With weaker light and difficult mathematical formulae 
 the writing must, of course, be larger and thicker. 
 According to Horner, fine lightly written figures of the 
 same size and with the same light cease to be seen at 
 all. But, even with the best light and a dull black 
 tablet, soft chalk, and signs written boldly and apart from 
 each other, the minimum necessary height was found to be 
 three times the height of black printed letters on white 
 paper. 
 
 * Price 6d. [50 Pfennige] 
 t Schweizer Schularchiv II., Nr. 4. 
 
CHAPTER XVI. 
 
 From a practical point of view, for higher schools, 
 Horner strongly urges, besides the use of good writing 
 materials, the use of several properly placed tablets, 
 which can be used in succession and by the side of 
 each other. From many experiments he draws the 
 following conclusions : 
 
 (1) Every school- should have a copy of Snellen's 
 Test Types, and the teacher should periodically test the 
 acuity of vision of the scholars. 
 
 (2) Every (teacher's) tablet should have marked upon 
 it the minimum size for letters and figures. 
 
 (3) The teacher should never sacrifice the clearness 
 of his letters or figures to other considerations, such as 
 beauty of form, saAig of space, &c. 
 
 (4) Except thos^Bteacher's) tablets which are of slate 
 or are faced witl^ skte, all .should be condemned, 
 especially the lacqueredAiid polished. 
 
 (5) The blackness, W the tablet depends on the 
 tablet's cleanliness. 
 
 Prof. Koster of Bonn has kindly informed me by 
 letter that from the -beginning of his career as a teacher 
 he has in his lecture-room, drawn, not with white chalk 
 on black wooden boards, but with soft charcoal on a 
 painter's canvas, sized a dull dirty white and stretched 
 on a wedge-frame. " The charcoal can be rubbed off 
 with a dry rag. Apart from cheapness, convenience for 
 drawing &c., the canvas^pfloes not reflect or shine. 
 From every place in Jfce lecture-room the drawing, black 
 on white, is seen eqiSnly well, and much more clearly 
 than white on a black ground." 
 
 I have for many years used in my own lecture-room 
 a tablet of dull glass on which I draw with white 
 and coloured chalks. The fablet does not dazzle, and 
 the drawings are seen very clearly. Perhaps Herr 
 Thieben will ^ succeed in making large-sized tablets of 
 his artificial stone. 
 
CH. XVII. WRITING, DRAWING AND HAND-WORK LESSONS. 
 
 CHAPTER SEVENTEENTH. 
 
 WRITING, DRAWING AND HAND-WORK LESSONS. 
 
 Weber recommends lead pencil as less tiring when a 
 great deal of very quick writing has to be done. It 
 is hardly necessary to say that pale ink is hurtful to 
 the eyes. Those inks which do not turn black till 
 afterwards should be wholly banished from schools. 
 
 Recently the attention of oculists began to be directed 
 to the method of teaching drawing. Dr. Stuhlmann 86 
 of Hamburg had invented what is known as the 
 stigmographic method of drawing, by which it was to be 
 possible to teach drawing to children of from six to nine 
 years. The system depends on a jumble of dots and 
 network, the harm of which, with small embroidery 
 patterns, no one could help seeing a priori. The 
 Society of German Drawing Masters has not only 
 protested against the introduction of this method into 
 Prussia, but has appealed to 22 oculists, twenty of whom 
 have agreed that the method is bad for the eyes and that 
 drawing generally at so early an age is unhealthy. 
 
 As with network-drawing, so stands the case with 
 the slant lines in copy-books. These lines, too, have been 
 forbidden in Saxony. It is simply unintelligible that 
 Adler's copy books should be allowed in the schools of 
 Hamburg, Holstein and Mecklenburg. The demand 
 made on the child's eye by having to track these faint 
 dots, no bigger than a pin-prick, must indeed lead to 
 myopia. (See Fig. LI 1 1.), where however the paleness 
 of the dots could not be accurately reproduced. 
 
 Now as experience had taught us that excessive 
 writing promotes myopia, I recommended that in higher 
 
1 92 CHAPTER XVII. 
 
 schools, from the third class, where excessive writing 
 begins, it should be compulsory to teach Stenography 87 . 
 
 FIG. LIII. 
 
 The stenographic characters are certainly smaller than 
 those of ordinary writing, but they are no smaller than 
 Greek letters. They are very easily learnt, and the 
 saving of time, as I know by the practice of almost 
 thirty years, is so great that no objection ought to 
 weigh against it. How many hours of home-work would 
 the pupils of the first and second classes be spared if 
 they could write down their rough drafts and preparations 
 in shorthand instead of in the ordinary character! And 
 it is in these very classes that short sight increases so 
 alarmingly. 
 
 According to Weber a great deal too much is made 
 of penmanship in Germany, while in France, England 
 and America far less time is devoted to teaching it. 
 
 Girls' sewing-lessons, also, need medical supervision. 
 So early as 1813 Beer 88 wrote: "I saw little land- 
 scapes embroidered on snuff-boxes with the so-called 
 pearl stitch. They were scarcely inferior to an excellent 
 miniature painting and showed an intelligence on the 
 part of the needlewoman which would have done credit 
 to any trained artist. With the deepest pleasure I looked 
 at those pictures till I thought of the eyes of the 
 worker, and the thought turned my joy to bitterness." 
 Words like these might be repeated to-day. Even in 
 Froebel's Kindergartens little children are taught occupa- 
 tions far too trying for their tender,, eyes 
 

 UNIV3 
 
 
 
 WRITING, DRAWING AND HAND-WORK LESSONS. 193 
 
 I have classified hand-occupations in four divisions, 
 according as the degree of fineness of the meshes and 
 stitches lets the work be seen with greater or less 
 difficulty, or not at all, at a distance of one foot. All 
 those^ coarse kinds of work, in which the meshes and 
 stitches can be clearly distinguished at arm's length 
 by a healthy eye are not injurious. Such are knitting, 
 crocheting with wool, netting, coarse darning, and ordinary 
 making of garments. The second kind of work has 
 to do with meshes and stitches which a healthy 
 eye can only see with a great effort at a distance 
 of one foot and at an angle of i minute. To this 
 class belong fine darning, appliqu of muslin on net for 
 curtains, embroidery in colours, the old German Holbein 
 embroidery (so called), mignardise crotchet and the 
 favourite filet-guipure. The third class includes fine 
 white needlework, English and French embroidery, button- 
 holing, satin-stitch and marking. This kind of work, 
 by its greater minuteness, leads very frequently to 
 myopia or asthenopia. The fourth class, that of super- 
 latively fine needlework point lace, petit-points, fine pearl 
 embroidery, and genuine lace work is absolutely injurious. 
 There is, moreover, a special reason for avoiding satin- 
 stitch in schools, namely, that this work is stretched on 
 a frame, which cannot be brought near the eye like 
 the other kinds of work, but the eye has to be brought 
 near to it, 
 
 Weber goes still further than I. He even condemns 
 knitting. " Who, for instance, would be 'plagued now-a- 
 days with knitting a stocking which requires from 35,000 
 to 60,000 meshes, according to the fineness of the 
 material, if it can be made faultlessly in three hours at 
 the longest ? " But Weber goes really too far, when he 
 proposes to give our girls, instead of a stocking, Greek 
 classics or teach them conic Jl sections. He is, how- 
 ever, in complete ">rd with me in forbidding all 
 
194 CHAPTER XVII. 
 
 
 
 handwork which must be held closer than 14 inches [35 
 centimeters] to the eye. Of course special tables are 
 needed for feminine hand-work : sewing-tables, long cushions 
 and, in the daytime, light from above. Generally, no 
 hand- work lessons should be given by lamp-light. 
 
 
CHAPTER XVIII. PRINT AND PAPER. 195 
 
 CHAPTER EIGHTEENTH. 
 
 PRINT AND PAPER. 
 
 As far back as the days of Francis the First, in 
 February, 1746, an imperial patent went forth concerning 
 " The books in the Holy Roman Empire and the Com- 
 mission by royal grace thereover appointed." *The words 
 of this patent were : " Seeing that we have heard with 
 displeasure that, to the hindrance reiliterarice, many printers 
 and publishers use paper that is much too bad and 
 letters that are hard to read, and that this has already 
 been commanded by Our predecessors to be changed 
 as a most mischievous thing, which command has up 
 to this day been ill obeyed, We therefore graciously 
 decree, in order to avoid the withdrawal of privilege in 
 respect of any such badly printed book, that every 
 publisher and printer shall henceforth use good white 
 paper and readable type" 
 
 Complaints have been made by oculists tens of years 
 past of the ever diminishing type of books and news- 
 papers. Von Arlt 90 in 1865 said very truly, " How 
 much mischief is done to the eyes by the Tauchnitz 
 stereotype editions of the Greek and Latin classics, by 
 the pearl type of our Groschen Libraries of German 
 poets and authors and by the diamond type of pocket 
 dictionaries in which as many as 50 words beginning 
 with a whole number of identical letters are arranged on 
 one page to the bewilderment of the eye that seeks 
 among them ! How much mischief, too, is done by the 
 
 * Cf. Emminghius's Corpus juris Germanici. 2nd ed. Jena, 1814. pp. 565, 567. Cf. 
 also Zopfi, Deutschc Rechtsgeschichte. 4th edn., 1872, II. p. 411. 
 
196 
 
 CHAPTER XVIII. 
 
 pretty little maps, where one would like to have a 
 magnifying glass in order to see the names of the 
 places ! The number of persons whose length, endurance 
 and keenness of sight has been ruined in this way is 
 in fact not small. I remember very well that, when I 
 had finished my student years, I was unable to distinguish 
 on the slope of a mountain about an hour distant the 
 same objects which I had seen very clearly when I was 
 in my i3th year." 
 
 Javal of Paris was the first to treat scientifically the 
 question of print. This he did in 1878 in his " Essai 
 sur la physiologic de la lecture " (Annales d' oculistique, 
 tome 79-82), a very valuable and thoughtful work. It 
 is only to be regretted that there are no diagrams with 
 this essay. 
 
 Javal in his observations chose for unit that size of 
 the national French type which measures about 0*4 milli- 
 meters. This unit does not exist in Germany ; the 
 
 8-point petitschrift approximately corresponds to it.* 
 
 | _ 
 
 SPECIMENS OF TYPES.t 
 
 Pearl . 
 
 n 
 
 
 
 n 
 
 
 
 n 
 
 
 Long Primer 
 
 n 
 
 
 Pica . . . .... 
 
 n 
 
 
 English . . . . / 
 
 n 
 
 
 Great Primer . . . 
 
 n 
 
 
 * Petitschrift is of about, the same size as our Brevier. [Eng. Ed.] 
 f The German original gives specimens of "n" in Perl-Schrift, Nonpareille, Petit, Corpus, 
 Cicero, Mittel and Tertia. The respective n's of these types have approximately the 
 following heights in millimeters: 075, I'D, 1*25, 1-5, 175, 2*0 and 2*5. These types 
 are about equivalent to the English types here given. Dr. Cohn gives also paragraph 
 specimens of German type, which are here omitted. In his Latin-printed pairs of 
 parapraphs the interlineages, in millimeters, are 'about' I and re, 175 and 2 ? 2 
 and 2-5, 2-5 and 3 respectively. [Eng. Ed.] 
 
PRINT AND PAPER. 197 
 
 [PARAGRAPH SPECIMENS, SHEWING FOR EACH TYPE A NARROWER 
 
 AND A WIDER INTERLINEAGE.] 
 
 NONPAREIL. 
 
 It is well-known that Schilling's design for It is well-known that Schilling's design for 
 
 r no, 
 
 everyone, which the travelling exhibition with the alwa >' s Present the appearance now familiar to 
 large plaster model has successfully endeavoured everyone, which the travelling exhibition with the 
 to make as life-like as possible. large plaster model has successfully endeavoured 
 
 to make as life-like as possible. 
 
 BREVIER. 
 
 It is well-known that Schilling's design It is well-known that Schilling's design 
 
 for the national monument on the Nieder- for the nationa i monument on the Nieder- 
 
 travelling exhibition with the large plaster now familiar to everyone, which the 
 model has successfully endeavoured to travelling exhibition with the large plaster 
 make as life-like as possible. model has successfully endeavoured to 
 
 make as life-like as possible. 
 
 LONG PRIMER. 
 
 It is well-known that Schilling's It is well-known that Schilling's 
 
 design for the national monument design for the national monument 
 
 on the Niederwald did not always on the Niederwald did not always 
 present the appearance now familiar , f / 
 
 to everyone, which the travelling P^sent the appearance now familiar 
 
 exhibition with the large plaster to everyone, which the travelling 
 
 model has successfully endeavoured exhibition with the large plaster 
 
 to make as life-like as possible. model has successfully endeavoured 
 
 to make as life-like as possible.* 
 
 PICA. 
 
 It is well - known that It is well - known that 
 
 Schilling's design for the Schilling's design for the 
 
 national monument on the national monument on the 
 
 Niederwald did not always Nie derwald did not always 
 present the appearance now nt ^ nce now 
 
 familiar to everyone, which ... , . . 
 
 the travelling exhibition with familiar to everyone, which 
 
 the large plaster model has the travelling exhibition with 
 
 successfully endeavoured to the large plaster model has 
 
 make as life-like as possible. successfully endeavoured to 
 
 make as life-like as possible. 
 
 * " This specimen shews the smallest print and the smallest interlineage that ought to 
 be allowed in school books." Dr. Cohn says of the German specimen to which this 
 English one approximates: "This specimen shews the smallest print [n = about 1*5 mm. 
 high] and the smallest interlineage [about 2*5 mm.] that ought to be allowed in school- 
 books." [Eng. Ed.] 
 
198 CHAPTER XVtll. 
 
 In estimating the effect of print on the eye very 
 various factors have to be considered. 
 
 i. The size of the letters. As, in looking at print, 
 we do not see the types themselves, which can be 
 measured by points*, but only printed letters, I 87 
 proposed to measure a short letter, " n " for instance, 
 which is easily done. I found that an Antiqua " n " 
 (see preceding table of types) of which the down stroke 
 is i mm. high corresponds to the Nonpareil type : 
 n= 1*25 mm. corresponds to Petit type: n= 1*5 mm. 
 corresponds to Corpus type (the name owes its origin 
 to an edition of the Corpus juris which was printed in 
 that type); n = 175 mm. corresponds to Cicero type. 
 Corpus type can certainly be read easily at the distance 
 of i meter ; indeed much smaller print can be seen at 
 arm's length. But in reading, and especially in reading 
 quickly, we want, not merely that the letters shall be 
 visible, but that they shall be easily legible; that is, 
 that they shall be read fluently, for a good length of 
 time and comfortably, at a distance of 20 inches 
 (y meter.) And in my opinion, if these conditions are 
 to be fulfilled, the height of 1*5 mm. is the least 
 permissible. Any type which is smaller than i'$ mm. 
 is injurious to the eyes. For this book t I have 
 even chosen Cicero type, so that the n is 175 mm. 
 high. 
 
 As an angle of sight of five minutes is sufficient for 
 the recognition of a letter, a healthy eye will, according 
 to Weber, be able to read clearly at the distance of 
 35 cm. [14 inches] the angle of convergence of the 
 eyes being then very moderate (11 21') a letter 07 
 
 * In England, as the printer informs me, the standard measure of type is pica, the 
 metal-block of which is \ of an inch high. An endeavour is, however, being made to 
 introduce the system of measurement by points. [Eng. Ed.] 
 
 t Of course Dr. Cohn is speaking of the German original. The English translation 
 is printed in type of about the same height as the original, but of greater breadth ; and 
 the English printer gives more space between letter and letter, word and word, line 
 and line. [Eng. Ed.] 
 
PRINT AND PAPER. 199 
 
 mm. in height. But, even Weber found that in these 
 circumstances the act of reading is, even to the best 
 eyes, very laborious and trying. A wide distinction 
 must be made between clear recognition and rapid 
 reading. Weber accordingly resorted to experiment in 
 order to solve the complicated question. He started from 
 the premiss that, the more favourable to the reader are 
 circumstances as to the size of the letters, the thickness 
 of the lines with which they are formed, the "approach" 
 (see below), the interlineage, the length of the lines of 
 text, the simplicity of meaning &c., so much more rapid 
 must be the act of reading, and so much less must be 
 the eye's expenditure of strength. He accordingly de- 
 termined the number of letters read in one minute* by 
 different persons and under very different circumstances. 
 From these experiments he found that, if the size of the 
 letters was greater than 2 mm., there was no increase 
 of speed; on the contrary the reading was actually retarded. 
 He decides, therefore, for a minimum height of 1*5 mm. 
 Unhappily only a few even of our medical journals 
 attain this minimum height of i '5 mm. ; in almost all 
 of them we find the ruinous Petit type of height 1*25 
 mm., and that not only for short notes, but often for 
 page-long records of cases, accounts of experiments, 
 critiques, reports, minutes of medical sessions, &c. The 
 opthalmic and hygienic papers, too, which ought cer- 
 tainly to take the lead in setting a good example, are 
 not free from Petit type. Even von Graefe and Saemisch's 
 large and widely - read Manual of Opthalmic Science 
 and the Central Opthalmic Journal have whole sections 
 printed in letters little more than i mm. high, and 
 
 * Weber found from these interesting experiments that the average number of 
 letters read in one minute was as follows: Aloud 1464, silently 1900; that is, 
 per second, 24 letters aloud and 31 silently. It takes, therefore, 0-0316 of a second 
 to recognise a letter and 0*0409 of a second to pronounce it. The difference, 
 00093 of a second, therefore expresses the time required, under the guidance of 
 the impression produced by the printed symbol, for setting free the mechanism of 
 the organs of speech. 
 
2OO CHAPTER XVIII. 
 
 therefore almost as small as Nonpareil type. And yet 
 the number of myopes among students, doctors, and 
 scientific investigators is so great. (Compare the measure- 
 ments of 42 medical journals, 30 natural science journals, 
 and 29 of the most usual school-books in the 5th table 
 appended to my address to the Danzig Assembly of 
 Scientific Investigators, 1880, and also my essay on the 
 eyes of medical students, published in the Vienna Medical 
 Yearbooks of 1881, in which the medical text - books 
 are especially mentioned with respect to their typo- 
 graphy.) 
 
 If a thing is unimportant, let it not be printed at all ; 
 if important, let it be printed in type of the proper 
 size. It is interesting to trace how journals which have 
 existed for nearly a hundred years have changed the 
 size of their type. Lavoisier's Annales de Chimie, for 
 instance, in 1789, and Gilbert's Annals of Physics in 
 1799, were printed in letters 1*75 mm. high; later the 
 height is only 1*5 mm. 
 
 No author should have any book printed in type 
 shorter than 1*5 mm. At any rate no doctor should 
 ever buy such a book. The Strassburg Commission, I 
 am glad to see, considers even this size too small for 
 school-books and prescribes type of 175 mm. for the 
 lower classes. I cordially agree. 
 
 In Zumpt's Latin Grammar, Kriiger's Greek Grammar, 
 Plotz's Manual de la Literature Fransaise and Vocabu- 
 laire an n=i'25 mm. is very frequent, In Ahn's French 
 Reading Book, in Schuster and Regniers', in Thieme's 
 and in George's Dictionaries, I found letters of I mm., and 
 in Lichtenstein and Lange's School Atlas, and also in 
 Sydow's Atlas, letters no larger than o'5 mm. ! 
 
 For wall maps Weber advises that the size of the 
 object looked at, the smallest townmarks, figures, letters, 
 signs &c., should be i square cm. [about *i6 of a 
 square inch] in a room five meters [about i6J^ feet] 
 
PRINT AND PAPER. 2OI 
 
 long, 2 sq. cm. in a room 10 meters long, and so on 
 in regular proportion. 
 
 Javal desires, with perfect justice, that in the school- 
 books of the ABC-scholars the letters shall not be 
 lessened very rapidly, before the children have become 
 so familiar with the forms of the letters as to be able 
 to read them easily. Unfortunately this is by no means 
 the case in the most highly recommended primers. 
 Javal wishes that it should be determined by experiment 
 how large the type ought to be in the different classes 
 in order that no scholar, however bad the light, may 
 have to get nearer to the book. 
 
 We have at length begun in Germany to print reading- 
 primers in type sufficiently large. In the year 1881 there 
 appeared in Magdeburg a " First Reading Book for 
 children with weak sight, whose eyes must be spared," 
 by Warmholz and Kurths. The smallest letters are from 
 4 5 mm. high. Now, as the first steps in learning to 
 read are just the most difficult, and as it is a matter 
 of experience that especially at this stage children pore 
 over the book in order to impress the letter-shapes on 
 their memory, it follows that reading books of this kind 
 ought to be adopted, not only for children with weak sight, 
 but for all children. Only, the letters should be still 
 thicker than they are in Warmholz's book, where they 
 are scarcely i mm. thick. 
 
 2. The thickness of the letters. This can only be 
 measured with magnifying glass and vernier. As a rule, 
 the letters are scarcely % mm. thick. Publishers are 
 very fond of thin type because of the saving in paper. 
 The picture of a thick letter upon the retina is of 
 course much broader than that of a thin one. The thick 
 letter is thus read more easily. Fortunately, modern 
 taste in German books is going back to the old 
 Swabian types, which are much thicker than those now 
 in general use. No print of which the down-stroke is 
 
2O2 CHAPTER XVIII. 
 
 thinner than o'2$ mm. should be tolerated in school- 
 books. 
 
 3. In Latin (or Antiqua) type the horizontal strokes 
 at the ends of the letters are important. Javal directs 
 attention to the fact that the rectangular Latin letters 
 are diminished in their apparent dimensions by the irradi- 
 ation of the white ground, that their angles thus appear 
 rounded off and the letters therefore appear smaller. They 
 look more like than 9. To obviate this, the corners must 
 be strengthened to make the letters appear rectangular ; for 
 instance, J. Ancient specimens of printing shew this 
 thickening of the ends of letters. I do not consider 
 it necessary in German type, because our letters at 
 the lower and upper end have broken outlines or swell 
 
 into knobs, e.g., 
 
 4. The shape of the letters. On this point the 
 advice of the Academy of Sciences in Paris was asked 
 in the days of Louis the Fourteenth. Their report 
 appeared in manuscript in 1704 and reposes to this day 
 in the Paris library, unpublished as yet. Javal, who has 
 gone deeply into this subject, shows that it is very easy 
 to read a line of Latin print if the lower half of the 
 line is covered with a sheet of paper, but exceedingly 
 difficult and often impossible if the upper half is covered. 
 He pointed out that the reader glances along the line 
 at a little distance above the centre of the letters, while 
 only five letters, g, j, p, q and y come below the line, 
 and these five letters, according to the calculations of 
 type-setters, occur on the average only 15 times for every 
 100 of those which come above or below the line. (In the 
 German type I found the proportion still more favour- 
 able. On account of the many capital letters the letters 
 below the line were only 5 in 100.) Javal founds on 
 his observation a proposition which favours the publishers 
 economy of paper : " The long letters which come below 
 
PRINT AND PAPER. 2O3 
 
 the line might be altogether suppressed without damage 
 to legibility." He thinks that the lower part of p and 
 q might be done away with, the tails of j and y 
 shortened, and g altered to an ancient and shorter shape. 
 I do not agree with this view. It seems to me, on the 
 contrary, that to break the monotony of short letters by 
 letters reaching above and below the line is very 
 beneficial to the eye, as preventing fatigue. It is by no 
 means desirable that the text-lines should be too close 
 together, especially in school-books. 
 
 On the other hand, attention may very well be 
 given to Javal's proposals to make some improve- 
 ments in the shape of n and u, e and c, so that they 
 may be less easily mistaken the one for the other. 
 There are unfortunately no diagrams, but Javal probably 
 
 wishes something like the following: \^ or 
 
 , i m, n. p, q, r, s. 
 
 In the German type there is danger of mistaking u 
 and u for each other, and also c and e. Our n might 
 
 be made rather broader than u : + ^ and J^, . At the 
 
 top of our c there could be a stroke such as there is on 
 
 s> : and {^^ In this way these letters would be 
 
 more easily read. 
 
 5. The approach or distance between letters and 
 between words, is also important. Every letter stands 
 out more distinctly by isolation when, as Laboulaye 
 proposed, the white space between two letters is wider 
 than the space between the two ground-strokes of the 
 letter. That is the reason why [in German books] we 
 emphasize by spacing out the type. Javal remarks quite 
 
2O4 CHAPTER XVIII. 
 
 rightly that this greater approach adds to legibility ; 
 a surprising remark from an investigator who attaches 
 so little importance to leading, or inter line age. Weber 
 found it best to put 60 letters on a line 4 inches long 
 [100 mm]. Laqueur asks for a space of at least 0-5 
 mm. between two letters. I should fix a minimum of 
 075 mm. [about "03 of an inch]. In this book the 
 distance is nearly i mm.* 
 
 6. It is well-known that, in printing, little "leads" 
 are inserted between the text-lines to prevent the long 
 letters above and below the lines from touching each 
 other. This process is called " leading." The wide 
 spaces between the text-lines are advantageous because 
 of their greater brightness and the stronger re-action 
 which this calls forth in the pupil of the eye. Javal, 
 however, looks upon the inserted leads as a pleasant 
 thing, a luxury, not a necessity, and considers that 
 legibility would not be affected by their omission. I 
 found that the compressed print is much more fatiguing, 
 even though it be in a somewhat larger type, than text 
 with spaces between the lines, because too little white 
 is left among the letters and all seems a mass of con- 
 fusion. A comparison of the compressed and the spaced-out 
 texts in the specimen types given above (p. 197) will 
 satisfy anyone of this. In my opinion the interlineage 
 must be ample. I have tested our school - books and 
 journals in this respect by measuring the distance from 
 the top end of an " n " and the lower end of a short 
 letter above it. Of course the apparent distance between 
 the text-lines is much smaller than we might from this 
 test suppose, because the letters reaching above and 
 below the others diminish the white space of the inter- 
 lineage distinctly more than do the short letters. 
 
 Weber does not profess to determine any absolute 
 minimum for width of interlineage, but only to determine 
 
 * The German Edition, See Note on p. 198. [Eng. Ed,] 
 
PRINT AND PAPER. 2O5 
 
 the ratio of this width to the size of the letters. He 
 makes this ratio i'5:2 for German type and 175:2 
 for Antiqua. This seems to me too little, as can be 
 seen by this present work.* The interlineage here is 
 nearly 3 mm., the Antiqua type 175 mm. high, and 
 yet the interlineage is nothing very wonderful. A 
 book has good interlineage when, if the letters are 1.5 
 mm. high, the lines are 3 mm. apart. A distance of 
 2 '5 mm. [about l /io of an inch] seems to me to be the 
 smallest admissible ; and the Strassburg Commission 
 agrees with this requirement. 
 
 In former times interlineage was more liberally given. 
 Arago's "Annales de Chimie," at the beginning of this 
 century, had 3-5 mm., but in 1843 on ly 3' 2 5 rrmi- 
 Gilbert's "Annals of Physics" shewed 4 mm. so late as 
 1799, while in the icoth volume, 1832, it had only 3 
 mm. On the other hand, the interlineage of the Central 
 Journal of Opthalmic Science is 2 mm., that of the German 
 and Berlin Weekly Clinical Journal 175 mm., of Schmidt 
 and Virchow's Yearly Report 175 mm., of the Chemical 
 Central Journal (in places) only 1-25 mm. I found in 
 primers 2 mm., in Zumpt's, Krliger's and Ahn's grammars 
 2 mm., in Teubner's Edition of Ancient Classics 2 mm., 
 in dictionaries 1*25 and even i mm. 
 
 7. The last point to be considered is the length of 
 the text-lines. The shorter the line the more easily is 
 it read, because the eyes have the less to be moved. 
 Java! believes the long lines to be the cause why 
 progressive myopia is so frequent in Germany. He 
 considers that, with long lines, short-sighted people must 
 exert their accommodation the more frequently and 
 strongly in the middle of the lines as their eyes are 
 focussed for the ends of lines. It may be so, but it has 
 not yet been proved. Fortunately, the quarto form for 
 books is growing more and more infrequent in Germany. 
 
 * The German Edition, See Note on p. 198. [Eng. Ed.] 
 
2O6 CHAPTER XVIII. 
 
 Already many journals are limited to 80 90 mm. [3-2 to 
 36 inches]. The lines of the Manual of Ophthalmic Science 
 by Graefe and Samisch are, however, 120 mm. [4*8 inches] 
 long. Even the quarterly Journal of Public Health has 
 lines of no mm. [4*4 inches]. Almost all the school- 
 books used in Breslau except Arm's Reading Book, 
 Ellendt's Grammar and Paulsieck's German Reading- 
 Book have lines of less than 100 mm. [4 inches]. It 
 seems to me that 100 mm. [4 inches] is the greatest 
 length admissible, and 90 mm. [3^6 inches] the best 
 length for lines of ordinary print where the "n" is 
 i '5 mm. high. With larger types, such for instance as 
 are used in the present work,* a line of no mm. [4*4 
 inches] is allowable ; the length adopted here is 109 
 mm. 
 
 Weber, indeed, concludes from his experiments that 
 up to a length of 150 mm. [6 inches], but not beyond, 
 long lines make it easier to read quickly. He requires 
 a minimum of 100 mm. [4 inches], a maximum of 150 
 mm. [6 inches] for the normal line. He wishes, there- 
 fore, that school-books should be printed where possible 
 in lines of 140 to 150 mm. [5*6 inches to 6 inches]. 
 In this case the whole of the white margin, which he 
 looks upon as superfluous, would have to be omitted, or 
 the book would be too big. This seems to me wrong. 
 The contrast of the dark print with a broad white 
 margin decidedly facilitates reading. 
 
 In future I would have all school-authorities, with 
 measuring rule in hand, place upon the Index librornm 
 prohibitorum all school-books which do not conform to 
 the following measurements : The height of the smallest 
 "n" must be at least 1*5 mm. \_'o6^ inches], the least 
 width between the lines must be 2*5 mm. [*i inches], 
 the least thickness of the "n" must be '25 mm. [*oi 
 
 * The German Edition. In this English Edition the lines are slightly longer than in 
 the German. [Eng. Ed.] 
 
PRINT AND PAPER. 2O7 
 
 inches], the shortest distance between the letters 75 mm. 
 ['03 inches] ; the greatest length of text-line 100 mm. 
 [4 inches] and the number of letters on a line must 
 not exceed 60. 
 
 Blasius 91 adds : " The ' n ' should not be narrower 
 than i mm. ['04 inches] ; Antiqua type must be spread 
 out as much as possible ; the colour of the letters must 
 be a pure uniform black." Blasius, who thoroughly ex- 
 amined, as to all the above-named points, 300 Brunswick 
 and 9 Bavarian school-books, found only 45 or 15 per 
 cent, of the Brunswick books equal to the hygienic 
 requirements ; 64 per cent, were unsatisfactory and 2 1 
 per cent, positively bad. The Bavarian books were con- 
 siderably better. Schubert 119 , too, among 70 school-books 
 used in Nuremberg, indicates 24 as more or less injurious 
 to the eyes. He wishes that in adjudicating on school- 
 books, besides the points above - mentioned, regard 
 should be had to density of type, i.e., the number of 
 letters on a square centimeter. 
 
 The type must be deep black, the paper untransparent, 
 and, according to Javal's advice, yellowish in colour. 
 Javal fears fatigue from a sharp contrast between black 
 and white. As the eye is not achromatic, light composed 
 of one colour only would be the surest preventive of 
 coloured circles of dispersion, but, as the light would 
 then be too weak, we ought, according to Javal, to 
 cut off at least the violet end of the spectrum. The 
 colour then remaining corresponds most nearly to un- 
 bleached wood paper. Moreover, the Hygienic Congress 
 at Turin in 1880 passed a resolution that in future all 
 school-books should be printed on yellow paper. 
 
 Weber, on the other hand, wants not yellow paper, 
 but pale grey. I prefer pure white, for yellow paper 
 causes bluish after-pictures, and black letters can be read 
 further off on a white ground than on a grey. This 
 question requires further experiments, 
 
2O8 CHAPTER XVIII. 
 
 Blasius thinks goodness of paper very important. 
 Paper should be as far as possible of uniform thickness, 
 because a thick sheet is printed much blacker, cceteris 
 paribus, than a thin sheet. 
 
 The materials of which the paper is made must also 
 be carefully taken into account. Formerly papers were 
 made almost entirely of linen rags and cotton rags ; additions 
 consisting of wood, straw and clay were very rare. The 
 reverse is now the case. The principal material of 
 paper, especially in school-books, is wood. Professor 
 Liidicke 91 of Brunswick has found that the showing- 
 through of print in school-books is chiefly owing to a 
 high percentage of wood shavings in the paper. The 
 wood is easily detected with a microscope. Another test 
 is to let fall on the paper a drop of sulphate of aniline. 
 The lighter or darker shade of brown thus brought out 
 shows the greater or less quantity of wood fibre. 
 
 On the other hand, accorting to Liidicke, the thickness 
 or thinness of the paper has nothing to do with the show- 
 ing-through of the print. Badly printed books, such as 
 Plotz's School Grammar, have paper '05 mm. thick ; 
 Hopf and Paulsieck's German Reading-Book has 0*060 
 mm., and Andrews Stories from Universal History 0*080 
 mm. Well printed books from Vieweg's have paper 
 0*075 mm. thick. 
 
 With regard to the treatment of the paper before, 
 during and after printing, the following matters should 
 be attended to. In order that it may better take the 
 ink the paper should be uniformly damped through 
 before printing : then, to make it as smooth as possible, 
 it is satined, that is, placed between zinc plates and 
 strongly pressed by steel cylinders. In printing, the 
 letters are pressed into the paper so that they stand out 
 in relief on the other side. Print in this state is called 
 " embossed." This effect is neutralised by placing the 
 printed sheets, after they have been thoroughly dried, 
 
PRINT AND PAPER. 20$ 
 
 between smooth pasteboards and subjecting them to a 
 long continued and very strong pressure. If this is not 
 done the printing appears upon the back of the leaf 
 very indistinct and much obliterated. If the printed 
 sheets are not dried the ink easily comes off from one 
 leaf on to its neighbour lying upon it, and thus the distinct- 
 ness of the print surfers greatly. 
 
 Blasius wishes for all school-books, strong paper of 
 uniform thickness at least equal to "075 mm., having 
 the least possible admixture of wood matter, satined, 
 free from embossing, carefully dried and of a slightly 
 yellow colour. 
 
210 CHAPTER XIX. 
 
 CHAPTER NINETEENTH. 
 
 SPECTACLES. 
 
 Spectacles are good or injurious according to circum- 
 stances. Among 10,060 children, I found in Breslau 
 1004 M f whom 107, or 10 per cent., wore concave 
 spectacles. In the village and middle schools I saw no 
 spectacles- wearer ; only two girls wore eye-glasses. Half 
 of those J/'s who were over 17 years of age had 
 begun to wear spectacles ; 14 wore lorgnons and 93 
 spectacles. 
 
 Of the scholars with Mi 1-5 spectacles were worn by 2 per cent. 
 
 >! I'5~ 2<2 5 ! 8 
 
 2>2 5 3' 20 
 
 } . 3' 4'5 46 
 
 ,, >4'5 > 66 
 
 Of concave glasses I found 26 neutralizing, 41 weaker 
 (corrective) and 40 stronger (over-corrective). Only 8 
 of the spectacles had been prescribed by oculists ; the 
 remaining 99 had been chosen at discretion. Two 
 scholars had even got stronger glasses than had been 
 prescribed for them ; 63 used spectacles during the 
 mathematical and geographical lessons only ; 47 kept 
 them on the whole day. 
 
 There is still a difference of opinion among oculists as to 
 prescribing spectacles for young myopes. Some have a 
 horror of any kind of spectacles so long as the eye is still 
 growing. Others (and, as I think, rightly) prescribe, for 
 medium degrees of myopia, spectacles weaker than are 
 required for neutralization, with the condition that they 
 are not to used for writing, but only for looking at 
 distant things for the blackboard. Whether, in higher 
 degrees of J/, spectacles may, or must be, given for 
 
SPECTACLES. 1 1 I 
 
 work as well, is a question difficult to decide by a 
 general rule, depending rather in each case on rapidity 
 of growth, tendency to lung disease, muscular circum- 
 stances of the eye, &c. At all events it is generally 
 better to prescribe, not spectacles, but lorgnons, which 
 in mathematical lessons, where the eye makes frequent 
 changes from the black-board to the note-book, can 
 drop off, or be taken off, much more easily than 
 spectacles. The removal of spectacles (as I know from 
 my own school-days) is at first omitted as troublesome 
 and, as distance-glasses are thus used for writing, M of 
 course is decidedly increased. Unfortunately the old 
 advice, to give no spectacles to short-sighted scholars, 
 but rather make them sit at the front desk, cannot 
 always be followed. Not long ago I proposed that a 
 boy should be placed at the front desk on account of 
 myopia. This was objected to. " The first five desks are 
 already filled with myopes." 
 
 A number of short-sighted . scholars whom I found in 
 the Breslau schools were, from want of glasses and 
 from their constant bad attitude, courting the increase of 
 their malady. Others had armed themselves with glasses 
 that were positively dangerous. Some had bought eye- 
 glasses from vanity. Others had chosen stronger glasses 
 than they needed, because their companions, who possessed 
 higher degrees of M, jeered at them for wearing weak 
 glasses ! 
 
 Erismann 10 found, among 1245 y ^> I22 ( 9 P er cent.) 
 wearing glasses. Among the latter he found 
 
 ioo per cent, with Atrophy of the Choroid (against 95 per cent, of all J/), 
 55 ,, Insufficiency and Strabismus ( ,, 32 ), 
 
 42 V <'i ( 22 ). 
 
 He also found 12 per cent, neutralising, 69 per cent, weaker 
 and 1 9 per cent, over-corrective glasses. From these figures 
 Erismann infers " that the use of concave glasses is in 
 itself distinctly injurious for those eyes which are still in 
 
Ill CHAPTER XIX. 
 
 process of changing their refractive relations." This is 
 an erroneous conclusion, 45 quite apart from the fact that, 
 from optical causes alone, the stronger concave glasses 
 diminish V. For what is there against assuming that 
 the children were not suffering from atrophy of the 
 choroid, bad V, or insufficiency before they got the 
 spectacles ? On studying Erismann's tables we find that 
 only one-third of those myopes who had bad V used 
 spectacles. Nor has Erismann ascertained for definite 
 degrees of M how long glasses had been worn, whether 
 constantly or periodically, nor whether for distance only, 
 or for work as well. 
 
 It is one of the most difficult questions to decide 
 whether or not concave glasses are injurioqs to myopes. 
 The following experiment might perhaps bring us nearer 
 to a solution : Let a certain number of M's, already 
 thoroughly examined with respect to degree of M, acuity 
 of vision and muscular and choroidal condition, be 
 observed, who have equally good light, equally good 
 desks, equal length of daily work and equal daily em- 
 ployment ; let half of them have corrective glasses and 
 half none ; and let them be examined again after months 
 and years. But even this experiment would not be a 
 complete proof, for here, as in other matters, hereditary 
 tendencies and individual differences would constantly 
 exert an influence. 
 
 In any case, far more injurious than the use of 
 proper spectacles is the forward stooping necessitated by 
 the higher degrees of M for those who work with- 
 out glasses. The increased flow of blood to the eye 
 and the scanty flow from it decidedly favours the pro- 
 gress of myopia, quite apart from the mischief done by 
 a stooping posture to the chest organs. 
 
 Circumstances were better in Konigsberg than in 
 Breslau and Petersburg. In Konigsberg Conrad 20 did 
 not find a single instance of too strong spectacles, since 
 
SPECTACLES. 2 1 3 
 
 all the glasses in use had been ordered by oculists. 
 School authorities should always forbid the wearing of 
 spectacles by any scholar without medical direction. 
 
 As there was no doubt that a number of cases classed 
 as M were at first merely cases of accommodation spasm 
 in E or in weaker M y the proposal was made to subject 
 such cases to a temporary treatment with atropine. 
 Indeed excellent results, though to be sure only tem- 
 porary, have been obtained by Dobrowolsky, Mooren, 
 Schiess, Derby, Schroder and others by the instillation 
 of atropine continued for several weeks. The accommo- 
 dation-muscle was entirely relaxed by this means. This 
 treatment is disagreeable to the scholar, whom it 
 dazzles ; and it leads, occasionally, to slight granulations 
 in the vessel of the conjunctiva (so called Atropin- 
 Conjunctivitis or Atropin-Trachoma) which, however, are 
 very quickly removed. It is in no case really dangerous. 
 
 Burchardt 92 applied for permission to try this experi- 
 ment on a large scale in a school at Berlin but, 
 unfortunately, his wish was refused by the Board of 
 Scientific Examinations. I have myself seen many cases 
 of M recede from a higher to a lower degree under 
 a continued treatment with atropine ; but for some years 
 past I have made counter experiments which have con- 
 vinced me that the self-same effect, without any of the 
 unpleasant accompaniments of the atropine cure, may be 
 obtained by giving the eye perfect rest, that is by an 
 entire neglect of all reading and writing for three weeks. 
 
 People whose short sight is progressive should abstain 
 altogether from reading and writing for some weeks in 
 the year ; for instance, in the long vacation. 
 
 Javal has recently ordered convex glasses for school- 
 children with commencing myopia, in order to enable 
 them to read without exerting their accommodation- 
 muscle, an exertion which, in his opinion, is the chief 
 thing that promotes myopia. He boasts of the result of 
 
214 CHAPTER XIX. SPECTACLES. 
 
 his battle with " the old style." It is true, and Bonders 16 
 has already brought the fact prominently forward, that 
 M is rare among watchmakers, because they use the 
 magnifying glass instead of their accommodation. I found 
 in Breslau, among 71 watchmakers 93 from 19 to 71 
 years of age, only 7 or 9 per cent. M. Of these only 
 four had become short-sighted in the course of their 
 trade. It must not, however, be forgotten that watch- 
 makers only look with one eye, that they sit at the 
 window and in a very good light, and that in Germany they 
 do not begin their work before their i5th year. Among 
 the Swiss watchmakers Emmert 27 found 12 per cent. M, 
 probably because the trade is learnt in Switzerland at 
 an earlier age. Just 39 follows Javal's advice and now 
 orders all commencing myopes for whom the ophthalmo- 
 scope gives E or H up to i '5 D to wear convex 
 glasses when at work. The results, however, have not 
 as yet been made known. It seems to me that the 
 increased forward stooping caused by the use of convex 
 glasses outweighs the benefit derived. 
 - In the case of hyperopes, spectacles for use during 
 work must of course be prescribed. 
 
CHAPTER XX. OVER-WORKING THE EYES, 215 
 
 CHAPTER TWENTIETH. 
 
 OVER-WORKING THE EYES. 
 
 With the subject of " over-pressure," which has been 
 so actively ventilated of late, we are here concerned 
 only so far as regards the question of over-working the 
 eyes of school children. It is most certain that over- 
 working the eyes may lead to short sight in spite of 
 the most favourable locale, the best desks, books &c. 
 Complaints of over-pressure are nothing new. Seventy 
 years ago, in Vienna, Beer 88 expressed himself as follows : 
 " Anyone who has tried, and tried in vain, as often as 
 I have done, to explain to parents and teachers, in the 
 kindest manner and with the most convincing arguments, 
 how utterly destructive to the eyes of growing young 
 people is the modern system of educational hot-house 
 forcing, must feel it hard indeed to have publicly to 
 repeat his counsels, well-meant and grounded on long 
 experience as they are, and to have to expect the 
 echo of his words to die away, or that they will be 
 heard by only a very few. People hug the ill-under- 
 stood principle that 'children must be occupied all day 
 long,' and so, all the day long, as fast as one master 
 leaves the room another comes in. Of reading, writing, 
 language-learning, drawing, arithmetic, stitching, singing, 
 piano and guitar-playing there is no end, till the 
 tormented creatures are pale, feeble and drooping and 
 become to such a degree short-sighted and weak-sighted 
 that at last there is nothing for it but calling in 
 doctors to give advice." 
 
 With the present number of school-hours, which 
 amounts in the National Schools to 20 22, 28 30, 
 3 33 a week, and in the Gymnasia mounts up even 
 
216 CHAPTER XIX. 
 
 to 36 a week, it ought to be a first principle, in 
 order to prevent as far as possible the danger from 
 sitting at writing, that no two lesson-hours in ivhich 
 writing has to be done should be consecutive. (Writing 
 and drawing lessons should generally be transferred to 
 the brightest hours of the middle of the day.) 
 
 The more we endeavour in our large towns to do 
 away with afternoon school because of the many incon- 
 veniencies attending it, the more frequently it happens 
 that lessons go on in the morning for five consecutive 
 hours. This is too much for body and mind. Invervals 
 of just five minutes at every two hours have been 
 rightly termed barbarous. There should rather be an 
 interval of 75 minutes after every hour and of half -an* 
 hour after three hours. During these intervals the teacher 
 should not be strict, but he should let the children get 
 up, go out of the room,' look out of the window, run 
 about, in short do anything which refreshes the body 
 and so also relaxes the accommodation. For the bodily 
 health and eyesight it would generally be better to return 
 to the old arrangement of three hours' school in the 
 morning and two hours' school in the afternoon. 
 
 Zehender 7 goes so far as to express a wish that in- 
 struction were given, not in lessons of an hour each, 
 but in lessons of half-an-hour and of a quarter of an 
 hour with long intervals between. He believes that, 
 generally, more could be learnt in a shorter time if the 
 teaching ability of the masters were greater. The 
 Rostock teachers have entered a protest against this 
 " unkind judgment " of their work. A great deal 
 certainly depends on the teacher, and it seems to me 
 especially unjust to appoint as teachers in gymnasia 
 men fresh from the University, who may be first- 
 rate philologists or excellent mathematicians, but have 
 never had the benefit of pedagogic instruction in the 
 art of teaching. Pedagogic training for the teachers of 
 
OVER-WORKING THE EYES. 217 
 
 higher schools is most desirable ; and with it may be 
 recommended an examination of these teachers in school- 
 hygiene, more especially as some of the older gymnasium- 
 teachers unfortunately meet efforts in aid of school- 
 hygiene in no very friendly spirit. 
 
 It is most important that after five or six hours daily 
 at school, the children should not be over-burdened 95 
 with many home-lessons. All superfluous copying and 
 all unnecessary reading should be strictly forbidden, simply 
 on account of the eyes. The centre of gravity of learn- 
 ing will always have to be in the school itself. For, 
 unfortunately, home studies are often carried on by 
 a much worse light and with much worse furniture than 
 is the case in school. Just expressly attributes the 
 increase of M to home-lessons by bad light and to the 
 constantly increasing demands on home diligence. In my 
 opinion one hour's daily home work for the lower 
 classes, two for the middle and, at the most, three for 
 the first and second classes ought to be sufficient. But 
 what is the state of the case in reality ? Alexi* has 
 calculated that in the fifth and sixth classes of the Berlin 
 Gymnasia the number of hours per week required for 
 home-lessons is 10 n, in the fourth and third classes 
 14*^ 22, and in the second and first so much as 
 33 and even more than that. The weekly maximum 
 recommended by Alexi and Chalybaus is : For the sixth 
 and fifth classes 3 9 hours, for the fourth and third 
 6 12 and for the second and first 12 18 hours. 
 
 The fifth conference of Silesian Directors,! on the 
 other hand, appointed the following maximum : For the 
 sixth and fifth classes 10 n^ hours, for the fourth 
 and third 15 19 hours, for the second and first 24 
 hours. What a pleasing contrast is the recommendation 
 
 * Report of the sixth meeting of the German Society for the promotion of Public 
 Health, at Dresden. 1878, p. 59. 
 
 t Haase, "Over-pressure of our young people," p. 29. 
 
2l8 CHAPTER XIX. 
 
 of the Strassburg Commission of Medical Experts, who 
 fix, as the weekly maximum, for the ninth to the seventh 
 class (children 7 to 9 years old) 6 hours, for the sixth 
 and fifth (children of 10 to n) 8 hours, for the fourth 
 and third (children of 12 to 14) 12 hours, and for the 
 second and first (15 to 18) 12 to 18 hours. 
 
 This ought to be the highest limit for home work ; 
 for often enough, private lessons and music lessons add 
 to the burden of home-work. 
 
 Zehender goes too far, however, when he lays down 
 the proposition that " no home tasks ought to be given 
 to school children." He looks upon all home tasks as 
 "the resource of an embarrassed teacher to prevent the 
 children when out of school from practising all sorts 
 of mischief and naughtiness." The Rostock teachers do 
 not agree with him. Indeed, even a teacher of the 
 greatest ability could never do without home-lessons ; 
 but from a medical point of view it is most strongly 
 advisable that they be as much as possible curtailed. 
 
 Herr von Gossler, the Prussian Minister of Education, 
 has recently done a very meritorious thing in recom- 
 mending to school-authorities the re-introduction of 
 gymnastic games. Hartwich of Dlisseldorf and the 
 Central Union founded by him for Physical Culture 
 among the People and in the School have for years 
 been energetic in directing attention to the importance 
 of these games. 
 
 Wholly indefensible is the practice of giving, as a 
 punishment, passages to be copied out many times over. 
 The Minister Falk, in an admirable decree of October 
 1 4th, 1865, gives an especial warning about this and 
 makes a direct appeal to parents to bring a complaint 
 before the authorities in case of the over-burdening of 
 children with home lessons. 
 
 Lastly, the parents, too, or those who have charge of 
 the children, must intelligently guide and control the 
 
OVER-WORKING THE EYES. 2IQ 
 
 children's private reading, banish all ill-printed books 
 and newspapers and prevent the reading for long together 
 even of well-printed books, except with breaks of half- 
 an-hour. They should also see to the reader's posture 
 and never allow any reading, writing, or drawing in 
 twilight or by fire-light or by insufficient artificial light. 
 
 The eye, too, must have Sundays and holidays for 
 days of rest. 
 
 , 
 UNIVE3 
 
22O CHAPTER XXI. 
 
 CHAPTER TWENTY-FIRST 
 
 DISEASES OF THE CONJUNCTIVA. 
 
 Schools are sometimes visited by a kind of epidemic 
 known as follicular catarrh of the conjunctiva, or even 
 by a granular trachoma. In the former case the reflect- 
 ing folds of the swollen conjunctiva (see end of Chap. I.) 
 are found to fit somewhat unevenly to the eyelid in 
 consequence of little blister-like elevations, which disappear 
 again without leaving a scar. In trachoma, or granular 
 inflammation of the eyes, or " Egyptian " inflammation as 
 it is popularly called, there are larger granular formations 
 in the folds of the conjunctiva, which in time produce 
 contraction and scars. As a rule it is not the school that 
 is to blame for this epidemic, but a boarding-house, which, 
 connected with the school, is the focus of the malady. 
 
 Such was the case, at least, in Breslau in March, 
 1874, when inflammation of the conjunctiva broke 
 out in an elementary school specially attended by 
 the children of a neighbouring orphanage. A committee 
 of oculists was appointed, which inspected all the schools 
 on account of the " supposed Egyptian inflammation of 
 the eyes." On this occasion I examined 5000 scholars 96 
 and found 378 with the mildest form of catarrh, 270 
 with follicular catarrh, 28 with higher degrees of follicular 
 catarrh and only 22 with the true granular inflammation. 
 Only four per 1000, therefore, had this severe form of 
 the disease. 
 
 As the large number of abnormal conjunctiva (698=13 
 per cent.) seemed extraordinary, I made a counter ex- 
 periment in a village chosen quite at hazard, Langenbielau 
 in Silesia. No one in the village had any suspicion of 
 an epidemic of eye-inflammation and no child complained 
 
DISEASES OF THE CONJUNCTIVA. 221 
 
 of its eyes. I found there, among 1000 village school- 
 children, the above four groups represented by the 
 numbers 54, 68, i, 2 ; in all 125 or 12 per cent, of 
 the scholars were diseased. In this village, then, there 
 was just the same state of things as in Breslau. It is 
 probable that these affections of the conjunctiva fre- 
 quently occur in a latent way in March ; whether at 
 other times of the year, I do not know. 
 
 That the house, and not the school, is the centre of 
 infection is probable by the breaking out of real 
 epidemics of trachoma in boarding-houses where wash- 
 basins and towels are used in common. Such, for 
 instance, was the case in 1867 in the Deaf and Dumb 
 Institution in Breslau, 97 where, out of in children in 
 residence, I found 84 attacked with trachoma, while 
 not a single case had occurred among those children 
 who attended the instruction but lived outside the house. 
 Moreover, the fact that the children who sat next in 
 class to those who were suffering never caught the 
 disease speaks against the conveyance of infection by 
 mere school-attendance. These epidemics are often very 
 obstinate. Our Deaf and Dumb Institution had to battle 
 with one for two years and was compelled temporarily to 
 close the boarding-house. 
 
 Becker and Manz 98 are authorities for the frequent 
 and quite harmless occurrence of follicular catarrh in 
 Freiburg, Karlsruhe and Constance* during the summer 
 of 1876. Manz examined at a time of absolute 
 repose the schools of Freiburg in Briesgau and found 
 among 896 boys i per cent, hyperaemia, 4 per cent, 
 swelling, and 5 per cent, follicle, in all 10 per cent. ; 
 among 807 girls 6 per cent, hyperaemia, 5 per cent, 
 swelling, n per cent, follicle, in all 22 per cent In 
 another girls' school he found n per cent, follicle and 
 
 * In Buenos- Ayres Roberts found among 12,464 eyes of school-children 3,388, or 27 
 per cent., attacked with conjunctivitis folliailaris. 
 
222 CHAPTER XIX. DISEASES OF THE CONJUNCTIVA. 
 
 in a village school 5 per cent, of the boys with follicle 
 and 21 per cent, of the girls, while I was not able to 
 show any difference in this respect between the two 
 sexes. After several months the state of things in the 
 Freiburg schools was unchanged. Follicular catarrh is 
 not contagious and therefore does not necessitate the 
 closing of the schools. The cure is spontaneous. On the 
 other hand, children with true granular inflammation 
 should, as Manz advises, be excluded from the school. 
 Except myopia and perhaps affections of the conjunc- 
 tiva, eye-diseases are not to be connected with school- 
 attendance. Thousands of children have, it is true, been 
 examined for colour-blindness. But this defect is born 
 with the child. It is as little related to the school, and 
 as little curable by training or practice, as is the lack 
 of an eye. 
 
CHAPTER XXII. THE SCHOOL-DOCTOR. 223 
 
 CHAPTER TWENTY-SECOND. 
 
 THE SCHOOL-DOCTOR. 
 
 It follows from the preceding investigations that the 
 school may, directly or indirectly, injure the eyes of 
 children and that therefore it is urgently necessary to 
 appoint special doctors, whose duty it would be to free 
 the establishments from violations of hygienic law and 
 generally to watch over the health of the scholars. 
 
 It is a matter of regret that, until very recently, 
 many school - authorities so little knew and appreci- 
 ated the importance of examining the scholars' eyes, 
 although they had before them, furnished by numerous 
 writers, statistical proofs, that were simply crushing, of 
 the increase of myopia in the higher classes of schools 
 in all countries. 
 
 As lately as 1878 it was disputed by a prominent 
 school-man in the Prussian Chamber of Deputies that 
 Dr. Niemann's investigations in Magdeburg had shown 
 an increase of myopia in the higher classes. It was 
 asserted, rather, that "weakness of sight" had not 
 increased from the lower to the higher classes. 
 
 I was able to give proof 34 that in this very town 
 of Magdeburg a most marked progress of myopia has 
 shown itself in both gymnasia (see above, Chapter VIII., 
 Table II.), and that no one has asserted that acuity of 
 vision decreases in the higher classes. Acuity of vision 
 and myopia are two very different things. 
 
 How bad, practically, the look-out still is with regard 
 to the observance of hygienic requirements, the following 
 quite outrageous facts, in addition to the instances given 
 in the preceding pages, may show. 
 
224 CHAPTER XXII. 
 
 In the year 1866 a committee of doctors and teachers 132 
 pointed out a number of the Breslau schools as too 
 dark. In several of these schools instruction goes on 
 and on to this day! In the Magdalen and Elisabeth 
 Gymnasia, where there are so many myopes (see 
 Chapter VIII. Table II.), the gas was burnt in 1866 
 for several hours daily in winter in open flames 
 without globe or cylinder. Noth withstanding the com- 
 mittee's advice, in various classrooms of these institutions 
 at the present moment everything remains as it was 17 
 years ago.* 
 
 Weber has had the same experience. "It is ten 
 years ago," he says, "that a committee of doctors, to 
 which my insignificance had the honour of belonging, 
 inspected the sanitary arrangements of all the schools 
 in Darmstadt. It has not come to my knowledge that 
 an impulse to useful action was thus given, and in my 
 recent visit to the schools I did not see the trace of 
 any such impulse. The only result seems to have been 
 * valuable ' material, beside which I hope the words I 
 speak to-day may not be placed as equally valuable." 
 
 One director complained to me that he was now 
 compelled for the sake of appearances to teach his own 
 children in his own school ; whereas, before he became 
 director, he used on account of the wretched lighting 
 of this school to send them to another. 
 
 A fresh instance has just now occurred of the 
 approval of the architectural plans of a very large 
 gymnasium without a medical man's having seen them. 
 
 There is not a single classroom in Breslau in which 
 big and little children sit at desks of different sizes. 
 
 Even though we are beginning to build the new 
 schools better, yet we continue to force fresh generations 
 into the old bad school premises, which have been 
 rightly called school-dens. Among the 60,000 schools of 
 
 * The date on Dr. Cohn's title page is 1883. [Eng. Ed.] 
 
THE SCHOOL-DOCTOR. 225 
 
 Germany how many are there that a doctor has never 
 set foot in ? How few teachers can remember ever 
 having seen a doctor in their classroom ? 
 
 And yet for years past the appointment of special 
 school - doctors has been recommended by various 
 writers by Schraube, 103 by Falk, 68 by Baginsky, 70 by 
 Virchow," and with peculiar distinctness by Ellinger. 75 
 When, in Danzig, at the meeting of Natural Scientists, 
 1880, I ended my address "on handwriting, print and 
 the increase of short-sight" by saying that we want 
 a school-doctor who, invested with dictatorial power, shall 
 have to decide upon all the hygienic arrangements of 
 schools, Chief Burgomaster von Winter, 100 a man 
 deserving great credit in respect of the hygiene of 
 Danzig, most keenly opposed the notion of a dictatorial 
 school-doctor, and thought we should rather choose to 
 wait and try to spread in wider and wider circles the 
 sense of the benefit and necessity of reform. Let this 
 always be permitted in the case of undertakings that 
 are costly or, as to their final results, not wholly free 
 from uncertainty ; but in the war against myopia we 
 must wait no longer. For, in consequence of this waiting, 
 short sight for nearly 20 years, in spite of continual 
 speaking and teaching about it, has been promoted in 
 the case of thousands of scholars. 
 
 And not only are new scholars continually becoming 
 short-sighted, but in many cases the tendency to myopia 
 is transmitted to their posterity. 
 
 As the supreme oversight of all schools belongs to the 
 State, and as the attainments of the aim of their teaching 
 is controlled by state commissions, so also should medical 
 commissions see that the claims of hygiene are satisfied 
 in all schools. This duty on the part of the State of 
 hygienic control, is a correlative of the universal school- 
 duty on the part of the subjects. Side by side with the 
 universal duty of parents to send their children to school 
 
226 
 
 CHAPTER XXII. 
 
 stands the right of the parents to have to send their 
 children to such establishments only as are healthy. 
 
 The conviction of the necessity for a school-doctor is 
 spreading in the most satisfactory manner in ever widen- 
 ing circles. 
 
 In connection with this subject three manifestoes, from 
 societies possessing in the highest degree the knowledge 
 of experts, have made their way to publicity in the last 
 few months. 
 
 I. The first manifesto came from the Medical Com- 
 mission of Strassburg, which consisted of Professors 
 Boeckel, Hoppe-Seyler, Jolly, Kestner, Kussmaul, Laqueur, 
 Neubauer, Ruhlmann and Wasserfuhr, under the presid- 
 ency of State-Secretary von Hofmann. It is to the 
 lasting credit of Field-Marshal von Manteuffel, Lord- 
 Lieutenant of Alsace-Lorraine, that he, unsolicited, con- 
 voked this commission of eminent medical professors to 
 draw-up a report on school hygiene. This valuable 
 report was published in September, 1882. 
 
 The 24 concluding recommendations of the Strassburg 
 Commission, a commission which for weeks observed 
 and deliberated in groups, are these : 
 
 i. The employment of scholars in school and for 
 school should be, per week, at the most : 
 
 YEAR OF 
 LIFE. 
 
 CLASS. 
 
 SITTING 
 HOURS. 
 
 SINGING 
 HOURS. 
 
 GYMNASTIC 
 HOURS. 
 
 WORKING 
 HOURS. 
 
 TOTAL. 
 
 7, 8 
 
 IX, VIII 
 
 18 
 
 2 / 2 
 
 4/ ' 51 
 /2 /2 
 
 6 / 
 
 /2 
 
 24 24Va 
 
 9 
 
 VII 
 
 20 
 
 2 / 2 
 
 4/ 5 / 
 /2 /2 
 
 56 
 
 28 29 1 /* 
 
 10, 11 
 
 VI, V 
 
 24 
 
 2 
 
 23 
 
 8 
 
 3637 
 
 12, 13, 14 
 
 IV, III 
 
 26 
 
 2 
 
 2 
 
 12 
 
 42 
 
 1518 
 
 II, I 
 
 30 
 
 2 
 
 2 
 
 1218 
 
 4652 
 
 2. Between every two lesson-hours, whether in the 
 morning or in the afternoon, there should be a pause 
 of 10 minutes. If more than two lesson-hours are con- 
 secutive there should be a pause of 15 minutes between the 
 2nd and 3rd and of 20 minutes between the 4th and 5th. 
 
THE SCHOOL-DOCTOR. 227 
 
 4. Let there be one half-holiday afternoon in the 
 course of every week and another at the end of the week. 
 
 4. Let no tasks be given between the morning 
 and afternoon of the same day. Sunday is to be 
 entirely free from school-work. 
 
 5. Let the Autumn holidays extend from the beginning 
 of August to the middle of September. No tasks to be 
 given during the Whitsuntide and Christmas holidays. 
 
 6. The arrangement as to summer holidays is judicious 
 and to be retained. 
 
 7. The maximum permissible number of scholars in the 
 several classes is to be regulated according to Pettenkofer's 
 rule. (According to Pettenkofer, every scholar requires 
 in every lesson-hour a supply of 60 cubic meters of air 
 [more than 35 cubic feet], or the air of the schoolroom 
 will contain more than the maximum permissible quantity 
 of carbonic acid, namely i per 1000). 
 
 8. We recommend that emulation be kept more 
 within bounds and that the one-sided principle be 
 abandoned of attaching so much importance to extempore 
 performances, and that all over-exertion in preparing for 
 the final examination be avoided. 
 
 9. Lessons which make great demands on reflection 
 and memory are to be given in the morning. 
 
 10. Besides the obligatory gymnastic lessons, swimming 
 practices, out-door games, excursions, and skating are 
 strongly to be recommended. Altogether, eight hours a 
 week should be devoted to bodily exercises. 
 
 11. In new buildings for higher schools, the class- 
 rooms, if less than i6ft. Sin. [5 meters] wide, should be 
 lighted by a single row of windows to the left of the 
 scholars. In all wider rooms there should be lighting 
 from both sides. In exceptional cases light may also 
 come from behind the scholars. 
 
 12. With one-side lighting care should be taken that the 
 rooms get their light from the east, west, or even north. 
 
228 CHAPTER XXII. 
 
 13. In school-buildings now existing the use, for 
 teaching, should be avoided of those rooms which get 
 their light only from the south. 
 
 14. Where the rooms have not a sufficient amount 
 of light, the defect should as far as possible be supplied 
 by bevelling the window - niches and by opening out 
 fresh windows above in the wall-spaces. 
 
 15. Rooms with insufficient light, especially corner 
 rooms in square courtyards, should not be used as class- 
 rooms. 
 
 1 6. Every schoolroom should be provided with roller 
 blinds and with sufficient appliances for artificial lighting. 
 
 17. The forms should be so placed that direct light 
 from the sky may get to every scholar. The part of 
 the room thrown into shadow by wide wall-spaces 
 between windows is therefore to be left unused. 
 
 1 8. No highly reflecting surfaces, such as white walls 
 &c., should be allowed near the school-buildings. 
 
 19. All faultily constructed desks, without exception, 
 should be done away with as soon as possible and 
 replaced by desks that are constructed rationally. (On 
 Page 35 f th e Report the Commission says : " To get 
 rid as quickly as possible of these (old) desks, which 
 their positive distance alone is sufficient to condemn, we 
 hold to be the most pressing necessity of school hygiene. 
 Every half -year s delay produces fresh mischief. It is by 
 no means a question of a great sacrifice of money. We 
 have made enquiry at a proper place as to the cost, 
 and we find that in Strassburg a large school for 500 
 scholars can be fitted up with new desks of the best 
 construction at an expense of 7500 marks [^375]. An 
 expenditure, therefore, of at most 80,000 marks [^4000] 
 once for all would suffice to provide all the higher 
 schools of Alsace-Lorraine with rationally constructed 
 desks, and at the same time to put an end to one of 
 the very chief of the mischiefs which lead to short sight.") 
 
THE SCHOOL-DOCTOR. 2 29 
 
 20. The print of school-books, charts and atlases 
 should be tested with regard to size of letters, form of 
 type, and distance between letter and letter, word and 
 word and line and line. All books &c. nut con- 
 forming to the above requirements (entirely in accordance 
 with those which I have proposed above in Chapter 
 XVIII.) are gradually to be banished from the school. 
 
 21. The time-tables should be so arranged as system- 
 atically to vary the occupations of the scholars and 
 especially to avoid the protraction of reading through 
 several consecutive hours. 
 
 22. Short-sighted scholars should be placed in the 
 front rows at the best-lighted places and relieved from all 
 tasks which try the eyes. Stigmographic drawing and fine 
 drawing of maps or geometrical figures should be avoided. 
 
 23. It is recommended that, for higher schools also, 
 regulations be issued for guidance as to building-plan, 
 furniture and equipment. 
 
 24. Designs for alteration or new-building of a 
 higher school should be examined and reported on, with 
 reference to these regulations by a medical expert 
 officially appointed for the purpose. 
 
 II. Shortly after the Strassburg conferences the 
 questions of eye-hygiene in schools were officially con- 
 sidered in the Grand Duchy of Hesse. So early as 
 March, 1881, Geh. Rath Weber had presented, in writ- 
 ing, to the Ministerial Department for the care of Public 
 Health at Darmstadt a valuable report and minute, based 
 on his own abundant experience and observation. This 
 document he now submitted to the deliberations of a 
 committee, consisting of the members of the Medical 
 College and fourteen directors of higher schools. The 
 Committee adopted the following theses, the " Ten 
 Commandments " of Weber (with the exception of the 8th) 
 " which owe their origin to a conscientious consideration 
 of the hygienic as well as the educational needs of the school." 
 
230 CHAPTER XXII. 
 
 1. With respect to the injurious consequences of bad 
 lighting, the windows, where it is not possible to have 
 skylights, must not be lower than the head of the scholar 
 as he stands upright. Windows in existing schools must 
 be provided with dull glass up to this height and, if on 
 the south or west side of the room, must be filled up to 
 the top with this glass. On the other hand, rooms for 
 drawing and feminine hand-work require in all cases light 
 from above. With respect to further requirements con- 
 nected with the question of lighting, it is imperatively 
 necessary that the laws relating to school-building be 
 subjected to a revision based on the hygienic principles 
 now established. 
 
 2. With respect to the principles, which have been gone 
 into, of good school desks: Lickroth's Normal School- 
 Desks, with leaf 50 cm. [20 inches] wide, should be 
 prescribed; but in rooms for drawing and feminine hand- 
 work furniture from another quarter should be used instead. 
 
 3. With respect to the varying heights of scholars in 
 the same class, the distribution of desks is to be guided 
 by measurements of the sizes of the children, taken at the 
 beginning of each half-year. 
 
 4. With respect to the necessity for adequate ventilation, 
 the injurious effects of long sitting and of making playtime 
 too short to restore the equilibrium thereby disturbed, each 
 lesson is to be limited to three-quarters of an hour and 
 the remaining quarter of an hour is to be filled up with 
 regulated bodily exercises, gymnastics, drill &c. 
 
 5. With respect to the injurious consequences of a bad 
 posture, teachers should be directed to see that a distance 
 of at least 35 centimeters [14 inches] be maintained between 
 the eye and the work and that the amount of light requisite 
 for this, which should be set forth in special test-tables, 
 be always provided. 
 
 6. With respect to the injurious effect of bad materials, 
 all things at variance with the principles given in the text 
 
THE SCHOOL-DOCTOR. 23! 
 
 (these are almost entirely in accordance with my own 
 proposals in Chapter XVIII.), whether printed matter or 
 net-ruled copy-books, tablets, drawing copies, blank maps 
 or too fine patterns of needlework, are to be banished. 
 
 7. With respect to the injurious effects of all near work 
 for children, at least up to the tenth year, and with 
 respect to the necessity for harder mental employment 
 for children of that age, an entire reform of this 
 instruction should be introduced. 
 
 8. With respect to the mental and physical mischiefs 
 resulting from calligraphy as now practised, a rounded 
 handwriting is to be substituted for it. 
 
 9. With respect to the very slight .mental gain 
 to be obtained from it, dictation should in principle be 
 forbidden. It should be allowed only for the briefest notes. 
 
 10. With respect to the necessity for a permanent 
 medical oversight of the schools hygienic requirements, a 
 
 Member of the Higher Medical Board should 
 
 be invested with plenary administrative and executive 
 powers and, if necessary, a special doctor should be 
 appointed for this duty. 
 
 We see, then, that our wish for a school-doctor has 
 been expressed by the Strassburg and Darmstadt Com- 
 missions also, though unfortunately not with the trench- 
 ancy and emphasis which in this matter are so especially 
 needed. 
 
 III. Lastly, the Committee of the International 
 Hygienic Congress, January, 1882, placed this very ques- 
 tion of a School-Doctor on the order of the day in 
 their programme for the meeting at Geneva, and 
 honoured me with the duty of drawing up a report, 
 with theses, "on the necessity for the appointment of 
 School-Doctors in all countries, and on their duties." 
 
 The theses which I brought forward, and which were 
 sent several months before the Congress to members 
 and supporters, were as follows ; 
 
232 CHAPTER XXII. 
 
 1. In the first place a comprehensive State hygienic 
 inspection, as soon as possible, of all public and private 
 school-premises now in use, is necessary. 
 
 2. The Government should appoint an imperial or 
 ministerial School-Doctor, who must have a place and 
 voice in the Ministry ; and for every province (Canton, 
 Department) a District School-Doctor, who must have 
 a place and voice in the Governing Council of the district. 
 
 3. At the beginning of the hygienic reform the District 
 School-Doctor must review every school in his district, 
 and close without mercy every school which is too dark, 
 or otherwise injurious to health, unless adequate improve- 
 ments are immediately carried out. 
 
 4. The school can injure health ; therefore every school 
 must have a School- Doctor. 
 
 5. Any practical doctor may be chosen as School- 
 Doctor by the school-authorities. 
 
 6. The School-Doctor must have a place and voice 
 in the school's governing body. His hygienic orders 
 must be carried out. 
 
 7. If his hygienic rules meet with resistance, the 
 School-Doctor must appeal to the District School-Doctor, 
 who has power to close the school. 
 
 8. One School- Doctor should never have the super- 
 vision of more than 1000 children. 
 
 9. The School-Doctor must give a hygienic report 
 on the site and plan of a new school and watch, with 
 respect to hygiene, over the progress of the building. 
 Attention must be paid to his orders about number, 
 situation and size of windows, arrangements for heating 
 and ventilation, offices and desks. 
 
 10. The School-Doctor must measure all the children 
 in every class at the beginning of every half-year and 
 place them at desks suitable to their height. 
 
 n. The School-Doctor must determine, every year, 
 the refraction of every scholar's eyes, 
 
THE SCHOOL-DOCTOR. 233 
 
 12. The School-Doctor has the duty of restricting 
 the number of pupils in rooms which have dark places 
 and of removing school-furniture that forces the child to 
 sit awry and school-books that are badly printed. 
 
 13. The School-Doctor has the right to be present 
 at any lesson ; he must, at least once a month, visit 
 every schoolroom during lesson-time and take especial 
 notice of the lighting, ventilation, and heating of the 
 rooms and also of the posture of the children. 
 
 14. The School-Doctor must be consulted in drawing 
 up the plan of instruction, in order that over-pressure 
 may be avoided. 
 
 15. Every case of a scholar with infectious disease 
 must be reported to the School-Doctor. He may not 
 allow the child to return to school until he is himself 
 convinced that all danger of infection is over and that 
 the books, copy-books and clothes of the child have been 
 thoroughly disinfected. 
 
 1 6. The School-Doctor must, if the fourth part of 
 the scholars are attacked by an epidemic, close the school- 
 department. 
 
 17. Every School-Doctor must keep a journal of all 
 hygienic occurrences and especially of changes in the eyes 
 of the scholars ; and he must forward the journal every 
 year to the Government School-Doctor. 
 
 1 8. The reports of the Government School-Doctors 
 are forwarded to the Ministerial School-Doctor, who 
 publishes yearly a general review of the school-hygiene 
 of the kingdom. 
 
 I was unable to be present at the Geneva Inter- 
 national Hygienic Congress in September, 1882, and 
 could not therefore present any report on the " School- 
 Doctor question." 
 
 However, my 18 propositions were unanimously 
 accepted by the Congress without discussion ; a sufficient 
 proof that, for experts, they contain nothing but self-evident 
 
234 CHAPTER XXII. THE SCHOOL-DOCTOR. 
 
 demands. Napias, 129 Gilbert and Huart merely dwelt on 
 the fact that in several towns of France and Belgium 
 school-doctors were already appointed. In the department 
 of the Seine there are 114 school-doctors employed, in 
 Lyon 8 ; and in Havre, Lille and Brussels the schools 
 are not without medical control/ 
 
 * In Frankfort-on-the-Main, too, since 1st April, 1883, a Town-Doctor, whose 
 duty it is to inspect the schools, has been in office. 
 
CONCLUSION. 235 
 
 CONCLUSION. 
 
 The time, it is to be hoped, is not far distant when 
 the Strassburg, Geneva and Darmstadt propositions will 
 be posted up in every schoolroom to serve as a daily 
 memento to teachers and school-boards. 
 
 Professor Manz 131 very aptly says : " All must help 
 boards, parents and teachers to remove, or at least to 
 diminish, the dangers, involved in modern intellectual 
 culture, to physical well-being. One-sided demands upon 
 the eyes must be withdrawn ; there must be no more 
 reading, and especially no more writing, than a normal 
 eye can bear without injury ; there will always be 
 marauders enough. The conviction that there is much 
 to amend in our school-hygiene is now pretty universal. 
 Much has already been amended ; but in many things 
 we are at the beginning, and in most we are still far 
 from the goal ; and therefore the school-question may 
 not yet by any means be dismissed from the order of 
 the day." 
 
 It must very thankfully be acknowledged that the 
 Government in Breslau, in a decree of the nth of 
 December, 1882, has directed the attention of the school- 
 authorities to the report of the Strassburg Commission 
 and has required them " to claim a report by medical 
 experts not only in the case of all new schools, but also 
 in respect of existing circumstances wherever they appear 
 to be injurious to health. We shall," expressly con- 
 tinues the decree, " direct the attention of District 
 Physicians to the fact that it is a part of their pro- 
 fessional duty to observe and advise on these matters 
 wherever an opportunity presents itself, and we have no 
 
236 CONCLUSION. 
 
 doubt that, in any important cases that occur, they will 
 gladly comply with the proposals which have been made 
 to them. But, on the other hand, it is advisable, both 
 in itself and on account of expense, that where the 
 District Physician does not live on the spot, the local 
 practitioners should in the first instance be interested 
 and consulted in this important matter, who, out of public 
 
 spirit, will gladly respond to the call Finally, we 
 
 herewith decree that plans for new school-buildings, with 
 the report of the District Physician, shall be henceforth 
 submitted to us for our approval" 
 
 Whoever has the welfare of our school-children really 
 at heart will certainly desire a permanent medical control 
 over all schools. All government decrees and enactments, 
 however well meant they may be, fail of attaining the 
 object striven for if hygienic supervision, as well as 
 educational, is not employed. 
 
 May the Ministers of Education in all countries, and 
 especially the German Imperial Health Office, call at last 
 into life the urgently needed institution of School-Doctors, 
 in order that the school may no longer incur the reproach 
 of promoting the myopia of children. Let the saying of 
 Bonders never be forgotten : " Every case of progressive 
 myopia is ominous of evil for the future." 
 
CATALOGUE OF LITERATURE. 
 
 1 James Ware, Observations relative to the near and distant sight of 
 different persons. Philos. Transact. London, 1813. Vol. I., pag. 31. 
 
 2 H. Schiirmayer, Handb. der med. Polizei. Erlangen 1856, pag. 61. 
 
 3 Prager Vierteljahrschr. 1848, pag. 165. 
 
 4 E. v. Jaeger, Ueber die Einstellung des dioptrischen Apparates im 
 menschlichen Auge. Wien 1861, pag. 17. 
 
 5 Riite, Zeitschr. fur Med., Chir. und Geburtsh. von Kiichenmeister 
 und Ploss. Leipzig 1866, Bd. V., pag. 233. 
 
 6 H. Cohn, Untersuchungen der Augen von 10,060 Schulkindern 
 nebst Vorschlagen zur Verbesserung der den Augen nachtheiligen Schul- 
 einrichtungen. Eine atiologische Studie. Leipzig 1867. 
 
 7 Thilenius, in Zehender's Vortrag iiber den Einfluss des Schulunter- 
 richtes auf die Entstehung der Kurzsichtigkeit. Stuttgart 1880. 
 
 8 Schultz in Radogoerelse for elementar larowerken i Upsala. Upsala 
 1870. 
 
 9 H. Cohn, Die Augen der Schiiler des Friedrich-Gymnasiums und 
 ihre Veranderungen im Laufe von i^ Jahren. Programm der Anstalt 
 1872 ; auch Nagel's Jahresbericht fur Augenheilk. Bd. III., pag. 190. 
 
 10 Erismann, Ein Beitrag zur Entwicklungsgeschichte der Myopic, 
 gestiitzt auf die Untersuchung der Augen von 4358 Schiilern. Archiv 
 fiir Ophthalm. Bd. XVIL, i, pag. i 79. 1871. 
 
 11 Maklakoff, Sitzungsbericht der phys. med. Gesellsch. in Moskau 
 (russisch). Ausziiglich aus Woinow in Nagel's Jahresber. fur Augenheilk. 
 Bd. II,, pag. 419. 1871. 
 
 12 H. Cohn, Refraction von 240 atropinisirten Dorfschulkindern. v. 
 Graefe's Archiv. Bd. XVIL, 2, pag. 305 330. 1871. 
 
 13 Kriiger, Untersuchung der Augen der Schiiler des Frankfurter 
 Gymnasiums. Jahresbericht iiber die Verwaltung des Medicinalwesens 
 von Frankfurt a. M. Bd. XV., pag. 84 97. 1873. 
 
 14 Hugo v. Hoffman, Augenuntersuchung in vier Wiesbadener Schulen. 
 Klin. Monatsbl. fiir Augenheilk. 1873, pag. 269 bis 291. 
 
 15 v. Reuss, Die Augen der Schiiler des Leopoldstadter Gymnasiums 
 in Wien. Jahresbericht der Anstalt. 1874. 
 
 6 Ott und Ritzmann, Untersuchung der Augen der Gymnasiasten in 
 Schaifhausen. Schweizer Correspondenzblatt. Nr. 21, pag. 600, 1874 
 und das Programm des Gymnasiums 1873-74. 
 
 17 A. Ott, Untersuchung der Augen der Realschiiler in Schaffhausen. 
 Correspondenzblatt fiir Schweizer Aerzte. 1874, pag. 583. 
 
 18 Max Burgl, Beitrage zur Aetiologie der Kurzsichtigkeit. Bayrisches 
 arztl. Intelligenzblatt. 1874, pag. 26. 
 
 19 Dor, Schule und Kurzsichtigkeit. Bern 1874. Rectoratsrede. 
 
11. CATALOGUE OF LITERATURE. 
 
 20 Max Conrad, Die Refraction von 3036 Augen von Schulkindern mit 
 Riicksicht auf den Uebergang von H in M. Dissert. Konigsberg 1874. 
 
 21 Peter Callan, Examination of coloured schoolchildren's eyes. Amer. 
 Journ. of Med. Sciences. Vol. LXIX., pag. 331 339. 1875. Ausziiglich 
 in Nagel's Jahresbericht fur Augenheilkunde. 1875. 
 
 22 Scheiding, Untersuchungsresultate der Augen der Schiller in dem 
 Gymnasium zu Erlanger--, Dissert. Erlangen 1876. 
 
 23 Oscar Koppe, Ophthalmoskopisch-ophthalmologische Untersuchungen 
 aus dem Dorpater Gymnasium. Inaug.-Dissert. Dorpat 1876. 
 
 24 Pfliiger, Untersuchung der Augen der Luzerner Schuljugend. Archiv 
 fur Ophthalm. Bd. XXII., 4, pag. 63117. 1876. 
 
 25 A. v. Reuss, Beitrage zur Kenntniss der Refractionsanderungen im 
 jugendlichen Auge. Archiv fur Ophthalm. Bd. XXII., i, pag. 211 281. 
 
 26 E. G. Loring, Are progressive myopia and conus due to hereditary 
 predisposition etc. Transact, of the internat. medic, congress. Philadelphia. 
 Sept. 1876. 
 
 27 E. Emmert, Ueber Refractions- und Accommodations-verhaltnisse 
 des menschlichen Auges. Bern. 68 S. Fol. mit Tabellen. 1877; ferner : 
 Ueber functionelle Storungen des menschlichen Auges etc. Bern 82 S. 
 1877. 
 
 28 L. Kotelmann, Die Augen der Gelehrtenschuler des Johanneums in 
 Hamburg. Programm der Anstalt. 1877. 
 
 29 A. Classen, Untersuchung der Augen der Schiiler der Realschule 
 des Johanneums in Hamburg. Nagel's Jahresbericht. 1877, pag. 371. 
 
 30 O. Becker, Das Auge und die Schule. Vortrag. Auszug im Cen- 
 tralblatt fur Augenheilk. 1877, pag. 66. 
 
 31 and 32 C. R. Agnew, Nearsightedness in the public schools. New 
 York Med. Record. 1877, pag. 34. 
 
 33 Hasket Derby, Boston Med. and Surg. Journ. 1877, pag. 337. 
 
 34 Niemann in H. Cohn's Aufsatz : " Die Verwechslung von Sehschwache 
 und Kurzsichtigkeit im preussischen Abgeordnetenhause." Deutsche med. 
 Wochenschr. 1877, Nr. 4. 
 
 35 Seggel, Bayrisches arztliches Intelligenzblatt. 1878, pag. 33. 
 
 36 Dor, Etude sur 1'hygiene oculaire au lycee de Lyon, Lyon me'dical. 
 1878. 
 
 87 M. Reich, Einiges iiber die Augen der Armenier und Georgier in 
 den Schulen von Tiflis. v. Graefe's Archiv fur Ophthalm. Bd. XXIV., 3, 
 pag. 231. 1878. 
 
 38 G. Haenel, Kurzsichtigkeit in Dresdner Schulen. Sanitare Verhalt- 
 nisse und Einrichtungen Dresdens. Festschrift 1878. 
 
 39 O. Just, Beitrage zur Statistik der Myopie und des Farbensinns. 
 Archiv fur Augenheilk. 1879. Bd. VIII., pag. 191. 
 
 40 Nicati, La myopie dans les e*coles de Marseille, Gaz. hebd., pag. 
 695. 1879. 
 
 41 & 53 Priestley Smith, Shortsight in relation to education. An address 
 delivered to the Birmingham Teachers' Association. Nov. 2, 1880. 
 Birmingham. Auszug im Centralbl. fur Augenheilk. 1880, pag. 507. 
 
 42 E. Netoliczka, Untersuchungen iiber die Farbenblindheit und Kurz- 
 sichtigkeit. Graz 1879, 1880, 1 88 1. Jahresbericht der steiermarkischen 
 Ober-Realschule, 28, 29, 30. 
 
CATALOGUE OF LITERATURE. III. 
 
 43 Florschiitz, Die Kurzsichtigkeit in den Coburger Schulen. Coburg 
 1880. 
 
 44 A. Weber, Ueber die Augenuntersuchimgen in den hoheren Schulen 
 zu Darmstadt. Referat und Memorial, erstattet der grossherzogl. Minis- 
 terial- Abtheilung fur Gesundheitspflege. Marz 1881. 
 
 45 H. Cohn, Bemerkungen zu Dr. Erismann's Untersuchungen dcr 
 Augen der Schulkinder. v. Graefe's Archiv. I T I. Bd. XVIL, 2, pag. 
 292304. 
 
 46 Donders, Anomalien der Refraction und Accommodation. Deutsche 
 Ausgabe von Becker. Wien 1866. 
 
 47 H. Cohn, Die Refraction von 240 atropinisirten Dorfschulkindern. 
 v. Graefe's Archiv. 1871. Bd. XVIL, 2, pag. 305 330. 
 
 48 Ott, Ueber die Beziehungen der Schule zur Entstehung von M 
 Schweizer Correspondenzblatt. 1878. Nr. 15. 
 
 49 Gartner in Gross' Aufsatz "Zur Schulgesundheitspflege." Deutsche 
 Vierteljahrschr. fiir orTentl. Gesundheitspflege. Bd. XL, pag. 441. 1879. 
 
 60 H. Cohn, Die Augen der Breslauer Studenten. 1867. Berliner 
 klinische Wochenschr. Nr. 50. 
 
 51 H. Cohn, Die Augen der Medicinstudirenden. Eine Zuschrift an 
 die k, k. Gesellschaft der Aerzte in Wien. Wiener med. Jahresbiicher. 
 1881. 
 
 52 A. C. Collard, De oogen der studenten aan de Rjiks-Universiteit'te 
 Utrecht. Proefschrift. Utrecht 1881. 
 
 53 & 41 Priestley Smith, Short sight in relation to education. An address 
 delivered to the Birmingham Teachers' Association. Nov. 1880. Bir- 
 mingham. Ausziiglich im Centralblatt fiir Augenheilk. 1880, pag. 507. 
 
 64 J. Gayat, Notes sur 1'hygiene oculaire dans les ecoles et dans la ville 
 de Lyon. Paris. Delahaye. 1874. 
 
 55 Pfliiger, Klin. Monatsbl. fiir Augenheilk. 1875, P a S- 3 2 4- 
 
 56 H. Derby, Transact, of the Americ. Ophth. Soc. 1879, P a g- 53- 
 
 57 Nagel's Jahresbericht fiir Augenheilk. 1871, pag. 414. 
 
 58 v. Arlt, Ueber die Ursachen und die Entstehung der Kurzsichtigkeit. 
 Wien 1876. 
 
 59 Loring, County med. soc. of New York. Nov. 5. Med. Record. 
 Nov. and New York Med. Journ. Dec. Ausziiglich in Nagel's Jahresbericht 
 fur 1877, pag. 376. 
 
 60 Javal, L'hygiene de la vue dans les ecoles rurales. Gaz. hebd. 1879, 
 pag. 49 und 481. 
 
 61 Nagel's Jahresbericht fiir Augenheilk. fiir 1879, pag. 400. 
 
 61a Fahrner, Das Kind und der Schultisch. Ziirich. 2. Aufl. 1865. 
 
 62 H. Cohn, Die Schulhauser und Schultische auf der Wiener 
 Weltausstellung 1873. Breslau 1873. 
 
 63 H. Cohn, Die Schulhygiene auf der Pariser Weltausstellung 1878. 
 Breslau 1878. 
 
 64 Schreber, Aerztlicher Blick in das Schulwesen. Leipzig 1858, pag. 22. 
 
 65 Javal, Essay sur la physiologic de la lecture. Annal. d'oculistique 
 1878 und 1879. Tome LXXIX LXXXII. 
 
 66 Zwez, Das Schulhaus und seine inncren Einrichtungen. Weimar 1864. 
 
IV. CATALOGUE OF LITERATURE. 
 
 67 Varrentrapp, Deutsche Vierteljahrschr. fiir offentl. Gesundheitspflege. 
 1869. 
 
 68 F. Falk, Die sanitatspolizeiliche Ueberwachung hoherer und niederer 
 Schulen. Leipzig 1868. 
 
 69 Pappenheim, Handbuch der Sanitatspolizei. Berlin 1859. 
 
 70 A. Baginsky, Handbuch der Schulhygiene. Berlin 1877. (The best 
 manual.) 
 
 71 Lang. Erfordernisse eines zweckmassigen Schulgebaudes. Braun- 
 schweig 1862. 
 
 72 Reclam, Deutsche Vierteljahrschr. fiir Gesundheitspflege. 1870. 
 
 73 H. Cohn, Die Schulhauser auf der Pariser Weltausstellung. Berliner 
 klin. Wochenschr, 1867. Nr. 41. 
 
 74 Kleiber, Programm der Dorotheenstadtischen Knabenschule in 
 Berlin. 1866 uno^ 1867. 
 
 75 Ellinger, Der arztliche Landesschulinspector, ein Sachwalter unserer 
 misshandelten Schuljugend. Stuttgart 1877. 
 
 76 Thome, Vortrag iiber Schulgesundheitspflege. Correspondenzblatt des 
 niederrheinischen Vereines. Bd. I, pag. 112. 
 
 77 Gross in Ellwangen, Grundziige der Schulgesundheitspflege. Nordlingen 
 1878. 
 
 78 Guillaume, Gesundheitspflege in den Schulen. 3. Aufl. Aarau 1865. 
 
 79 Erasmus Schwab, Die osterreichische Musterschule fiir Landgemeinden. 
 Wien 1873. 
 
 80 Fankhauser, Ueber Schulgesundheitspflege. Bern 1880. 
 
 81 Gross, Med. Correspondenzblatt des Wiirttembergischen arztlichen 
 Vereins. Bd. XXXVI, Nr. 32, pag. 256. 
 
 82 Hermann Meyer, Die Mechanik des Sitzens mit Riicksicht auf die 
 Schulbankfrage. Virchow's Archiv, Bd. XXXVIII, Heft. i. 1867. 
 
 83 Schubert, Ueber den Einfluss der rechtsschiefen Schrift auf das Auge 
 des Schulkindes. Bayrisches arztl. Intelligenzblatt. 1881, Nr. 6. 
 
 84 Gross, Die rechtsschiefe Schreibweise als Hauptursache der Scoliose 
 und der Myopic. Stuttgart 1881. 
 
 86 Horner, Deutsche Vierteljahrschr. fur offentl. Gesundheitspflege. 
 Bd. X, Heft 4. 1878. 
 
 86 Urtheile von Augenarzten iiber das Liniennetz-, Punktnetz- und 
 Stickmusterzeichnen nach Dr. Stuhlmann's Methode. Herausgegeben von 
 Hermann Graeber. Sep.-Abdr. aus der Zeitschr. des Vereins deutscher 
 Zeichenlehrer. Heft 15. August 1880. 
 
 87 H. Cohn, Schrift, Druck und iiberhandnehmende Kurzsichtigkeit. 
 Rede, gehalten auf der Naturforscher-Versammlung in Danzig. 1881. Tage- 
 blatt. Nr. 3. Mit 5 Tabellen und Abbildungen. 
 
 88 G. J. Beer, Das Auge, Wien 1813. 
 
 89 H. Cohn, Die Augen der Frauen. Vortrag. Breslau 1879. 
 
 90 v. Arlt, Die Pflege der Augen im gesunden und kranken Zustande. 
 Prag 1865. 
 
 91 Blasius, Die Schulen des Herzogthums Braunschweig. Deutsche 
 Vierteljahrachr. fiir offentl. Gesundheitspfl. Bd. XIII, Heft 3. 
 
UNIVE 
 
 CATALOGUE 0V LITERATURE. V. 
 
 2 Burchardt, Eulenberg's Vierteljahrschr. fur gerichtl. Medicin. Bd. 
 XXIX, Heft 2 ; auch kurzer Bericht iiber den Bescheid der wissenschaft- 
 lichen Priifungs-Deputation in der Berliner klin. Wochenschr. 1878, Nr. 
 41. 
 
 93 H. Cohn, Die Augen Uhrmacher, Goldarbeiter, Juweliere und 
 Lithographen. Centralbl. fiir Augenheilk. 1877. Apr. 
 
 94 Erklarung der Rostocker Lehrer. Rostocker Zeitung, 2., 4., 5. 
 Marz 1880; auch in Zehender's Schrift iiber den Einfluss des Schulun- 
 terrichtes auf die Entstehung der Kurzsichtigkeit. Stuttgart 1880. 
 
 95 Die Ueberbiirdung der Schulkinder. Bericht des hygienischen 
 Congresses in Niirnberg. 1877, 
 
 90 H. Cohn, Bindehautkrankheiten unter 6000 Schulkindern. Centralbl. 
 fiir Augenheilk. 1877. Mai-Heft. 
 
 97 H. Cohn, Ueber eine Epidemic von granuloser Augenentziindung in 
 der Breslauer Taubstummen-Anstalt Jubelschrift der Anstalt. 1869. 
 
 98 Manz, Eine epidemische Bindehautkrankheit in der Schule. Berliner 
 klin. Wochenschr. 1877. 36. 
 
 99 Virchow R., Rede im preuss. Abgeordnetenhause am 13. December 
 1880. Sitzungsbericht, pag. 689. 
 
 100 v Winter, Tageblatt der Naturforscher-Versammlung zu Danzig. 1880. 
 Nr. 4, pag. 69. 
 
 101 Virchow, Ueber gewisse, die Gesundheit benachtheiligende Einflusse 
 der Schulen. Virchow's Archiv. Bd. XLVI. 1869. 
 
 102 Colsmann, Die iiberhandnehmende Kurzsichtigkeit unter der deutschen 
 Jugend. Barmen 1872. 
 
 103 Schraube, Die sanitatspolizeiliche Beaufsichtigung der Schulen 
 1859. 
 
 104 Passavant, Ueber Schulunterricht vom arztlichen Standpunkte. 1863. 
 
 105 Freygang, Die Schule und die leiblichen Uebel der Schuljugend. 
 Leipzig 1863. 
 
 106 Fink, Polytechn. Centralbl. 1855. Lief. 6. 
 
 107 Guillaume, Gesundheitspflege in den Schulen, Aarau 1865. 
 
 108 Parow, Vortrag iiber die Reform der Schultische. Berliner Schul- 
 zeitung. 1865. 
 
 109 Buchner, Zur Schulgesundheitspflege. Niederrhein. Correspon- 
 denzblatt. 1873. 
 
 110 A. Hermann, Ueber die Einrichtung zweckmassiger Schultische. 
 Braunschweig 1868. 
 
 111 Bock, Centralbl. fiir die gesammte Unterrichts-Verwaltung. Berlin 
 1868, pag. 486. 
 
 112 E. Meier, Lehrplan fiir den Unterricht im Schonschreiben. Fran- 
 kenberg i. S. 1882. 
 
 113 H. Cohn, Berliner klin. Wochenschr. Nr. 41. 1867. 
 
 114 v. Reuss, Real-Encyclopa'die der Medicin. XII., pag. 246. 
 
 115 Cardot. Traite de mobilier scolaire. Paris 1881. 
 
 116 Kaiser, Privil. Subsellien-System. Miinchen 1876. 
 
 117 Hippauf, Eine neue Schulbank. Ostrowo 1877. Auch im Central- 
 blatt f. d. ges. Unterrichts-Verwaltung in Preussen. 1877. Mai-Heft. 
 
VI. CATALOGUE OF LITERATURE:. 
 
 118 Aerztliches Gutachten iiber das hohere Schulwesen Elsass-Lothringens. 
 Im Auftrage des kaiserlichen Statthalters erstattet von einer medicinischen 
 Sachverstandigen-Commission. Strassburg 1882. 
 
 119 Schubert, Die Schulbiicher der stadtischen Unterrichts-Anstalten 
 Niirnbergs, pag. 99 ff. In den Mittheilungen aus dem Verein f. offentl. 
 Gesundhcitspflege der Stadt Niirnberg. 5. Heft. 1882. 
 
 120 Klopsch, Orthopadische Studien. Breslau 1861. 
 
 121 Javal E., Hygiene de la lecture. Bull, de la societe de medecine 
 publique et hygiene professionelle, pag. 569 575. 
 
 122 Javel E., De la couleur du papier d'impression au point de vue 
 hygienique. Societe de biologic. 21. Fevr. 1879. Refer, in Revue 
 d'hygiene. 1879, pag. 410. 
 
 123 Trelat Emile, Distribution de la lumiere dans les ecoles et 
 amenagement de 1'insolation dans les classes. Revue d'hygiene I. Nr. 7, 
 1879* Pag- 576. 
 
 124 L'etude et les progres de I'hygiene en France de 1878 a 1882 par 
 Napias et Martin. Paris 1882. 
 
 125 Narjoux Felix, Reglement pour la construction et ameublement des 
 maisons d'ecole. Paris 1881. 
 
 126 Bertin-Sans. Le probleme de la Myopic scolaire. Annal. d'hygiene. 
 publique. torn VII., pas; 46 und pag. 127, 1882. 
 
 127 Laynaud, Une type d'ecole a jour unilateral a St.-Denis. Revue 
 d'hygiene. 1881, pag. 1021. 
 
 128 Napias, 1'exposition de projets et modeles de bailments scolaires. 
 Revue d'hygiene. 1882, pag. 563. 
 
 129 Revue d'hygiene. 1882, pag. 830. Debatte iiber Schularzte auf 
 dem Congresse zu Genf. 
 
 130 Westphal Aug., Conrector. Ueber Schulhygiene. Programm des 
 Gymnasiums zu Schleiz. 1881. (Increase of M from the 6th class to the 
 ist : 32%. 35, 54, 54, 54, 85%.) 
 
 131 Manz, Die Augen der Freiburger Schuljugend. Vortrag. Freiburg 
 i. B., 1883. (Increase of M in the Gymnasium from the 6th class to the 
 ist: 7%, 18, 16, 26, 40, 50, 50, 51, 6o%.) 
 
 132 Jahresbericht der schlesischen Gesellschaft fiir vaterlandische Cultur. 
 1866. Padagogische Section. Promemoria : "Zur Verbesserung der Schul- 
 zimmer." 
 
 133 Soennecken, Das deutsche Schriftwesen und die Nothwendigkeit 
 seiner Reform. Bonn 1881. 
 
 134 Erismann, Hygiene der Schule. Im Handbuch der Hygiene von 
 Pettenkofer und Ziemssen. II., 2. 1882. 
 
 135 Keicher W., Neue Construction einer Schulbank. Quartalschrift 
 fur Erziehung und Unterricht. Biberach 1866, pag. 208. (Contains 
 drawing of hinge for flap desks.) 
 
 136 Barnard Henry, School Architecture. New York 1860. 
 
 137 Treichler, Verhiitung der Kurzsichtigkeit durch Reform der Schulen 
 im Geiste Pestalozzi's. Ziirich 1876. 
 
 138 Berlin und Rembold, Untersuchungen iiber den Einfluss des 
 Schreibens auf Auge und Korperhaltung des Schulkindes. Stuttgart 1883. 
 (Increase of M in the Eberhard Gymnasium from the 6th class to the 
 ist: 20%, 15, 30, 37, 45, 57, 67, 41, 70, 75%.) 
 
CATALOGUE OF LITERATURE vn. 
 
 139 Roberts P. F., Hijiene ocular. Eximen de la vision practicado en 
 las escuelas publicas de la ciudad de Buenos-Aires. Buenos- Aires 1882. 
 
 140 Esmarch, Zur Belehrung iiber das Sitzen der Schulkinder. Kiel 
 1883. 
 
 141 Ritzmann E., Hygienische Rathschlage gegen das Ueberhandnehmen 
 der Kurzsichtigkeit bei der Schuljugend. Beilage zum Osterprogramm der 
 Schulen Schaffhausens. 1883. 
 
 142 Horner, Schweizer Schularchiv II, Nr. 4. 1881. 
 
The Midland Educational Co.'i 
 
 PREMISES, 
 
 COBPOEATION STSBET. 
 
 SI&YEK MEDAIa, 
 
 Awarded for Excellence of Manufacture of School and 
 other Desks, International Health Exhibition, 1884. 
 
 DEPARTMENTS. 
 
 THE EDUCATIONAL DEPARTMENT 
 
 presents great advantages in the supply of School 
 Books, School Stationery, School Materials, Artists' 
 Materials, and School Furniture of every descrip- 
 tion. 
 
 THE GENERAL BOOKSELLING DE- 
 PARTMENT embraces the most varied and 
 extensive stock to be met with in the Midland 
 Counties. 
 
 THE BIBLE DEPARTMENT includes every description of Bibles, 
 Prayer Books, Church Services, Publications of the CHRISTIAN KNOWLEDGE 
 SOCIETY, Church Sunday School Institute, Wesleyan Conference Office, Re- 
 ligious Tract Society, National Society, &c. 
 
 THE FANCY GOODS DEPARTMENT contains a choice collection 
 of Work Boxes, Desks, Inkstands, Satchels, Photo Albums, Purses, Pocket 
 Books, and Fancy Articles of all kinds. 
 
 THE STATIONERY DEPARTMENT includes Writing and Commercial 
 Paper and Envelopes, Ledgers, Cash Books, and every description of General 
 and Office Stationery. 
 
 THE PRINTING DEPARTMENT is fitted up with the Newest 
 Machiney and styles of Type, and is adapted for the rapid execution of all kinds 
 of Commercial, Legal, School, and General Work. Ornamental Printing, in 
 Gold and Colors, receives special attention. 
 
 THE BOOKBINDING DEPARTMENT is thorough and complete. 
 Every description of Bookbinding in cloth, half-roan, half-calf, full-calf, Morocco, 
 Russia, executed efficiently and promptly. Special Rates for large quantities. 
 
 THE SCHOOL. OFFICE, AND HOME FURNITURE DE- 
 PARTMENT. The whole of the Furniture manufactured by us is made by 
 the most experienced Cabinet Makers, and is superior to the ordinary Machine- 
 made Furniture. Great care is taken in the selection of the Wood, and all Goods 
 are guaranteed to be of the best possible quality. 
 
 THE KINDERGARTEN DEPARTMENT comprises a complete 
 Stock of every requisite for Kindergarten and Infant Schools. 
 
 CATALOGUES ON APPLICATION, 
 
APPLIANCES FOR THE 
 
 PREVENTION OF MYOPIA, 
 
 (SHORT-SIGHT,) 
 
 MANUFACTURED AND SOLD 
 
 BY THE 
 
 MIDLAND EDUCATIONAL CO,, 
 
 BIRMINGHAM & LEICESTER. 
 
THE HYGIENIC DESK (Patent). 
 
THE HYGIENIC DESK. (Patent.) 
 
 SOLE MANUFACTURERS : 
 
 THE MIDLAND EDUCATIONAL COMPANY, 
 
 BIRMINGHAM AND LEICESTER. 
 
 This Desk is confidently recommended as fulfilling every Hygienic 
 requirement. It has been designed for the MIDLAND EDUCATIONAL 
 COMPANY by MR. PRIESTLEY SMITH, Ophthalmic Surgeon to the 
 Queen's Hospital, Birmingham, and embodies the principles laid 
 down by DR. COHN (author of "Hygiene of the Eye"), and other 
 authorities on School Hygiene. 
 
 Attention is called to the following particulars 
 
 (1) The Back is so constructed that it gives the required support while 
 
 the pupil is at work a most important consideration. 
 
 (2) The Seat is broad and gives ample support to the legs. 
 
 (3) The Top is made of a convenient size, and the Book-rest at the 
 
 back is fixed at the proper angle and distance from the eye. 
 
 (4) One of the most important Hygienic requirements is the provision 
 
 for the top to overhang the seat. This is fully met, and by a 
 simple mechanical contrivance (which cannot possibly get out 
 of order) ample room is allowed for the easy egress of the 
 pupil. 
 
 (5) Price: Pitch Pine, French Polished, Single Desk, i 55. od. ; 
 
 Dual, 2 2s. od. 
 
In an article "On Means for the Prevention of Myopia," (Ophthalmic 
 Review, June, 1886,) 
 
 Mr. PRIESTLEY SMITH Says : " To prevent myopia we must 
 prevent youn people from using their eyes too closely and too long 
 on near objects.. 
 
 " This principle was established long since by the labours of Bonders, 
 Arlt, and others, and has been practically developed by Cohn and other 
 reformers of School Hygiene. 
 
 A New School Desk. 
 
 " Much ingenuity has been devoted to the construction of school 
 desks and seats, and very many different models, each claiming some 
 advantages, have been publicly exhibited during the last few years. At 
 the request of the Midland Educational Company, I have lately designed 
 a school desk which embodies the recognised essentials in as simple and 
 inexpensive a manner as seems to me to be possible. These recognised 
 essentials are as follow : 
 
 " i. The seat must be of such height as will allow the scholar's feet 
 to rest flat upon the floor or footboard, and broad enough to support the 
 greater part of the thigh. 
 
 " 2. The seat must have a back placed at such height as to fit the 
 hollow of the back below the shoulder blades, and support the body in a 
 vertical position. 
 
 " 3.- The near edge of the desk must be just so high above the seat 
 that when the scholar sits square and upright with elbows to the sides, 
 the hand and forearm may rest upon the desk without pushing up the 
 shoulder. 
 
 "4. As used in writing, the desk must have a slope of 10 to 15 
 (about i in 5); as used in reading, it must support the book at an angle 
 of about 45, and at a distance of at least i2in. from the eyes i6in. is 
 better (30 4ocm.). 
 
 "5. As used in writing, the edge of the desk must overhang the edge 
 of the seat by an inch or two, in order that the scholar shall not need to 
 stoop forwards, and that the support to the back may be maintained. 
 
 "6. Either the desk or the seat, or some part thereof, must be 
 movable at pleasure, so that although the desk usually overhangs the 
 seat, the scholar may be able at any time to stand upright in his place. 
 
 " 7. The desks and seats must be of various sizes, in order that the 
 foregoing conditions may hold good for scholars of various ages. 
 
 "In a recent paper describing a systematically graduated series of 
 desks (' Progressieve Schoolbanken,' J. van Druten, Utrecht), Professor 
 Snellen gives a table of proportionate dimensions. ***** 
 
 "Adopting with little alteration the proportions given by Snellen for 
 the various parts of his desk, I have, for the sake of convenience and 
 economy, slightly altered the progression, and reduced the number of 
 sizes to four. Instead of advancing by increments of one-tenth, which 
 is doubtless the right method from the theoretical point of view, I 
 divide the scholars according to their heights into four classes advancing 
 in each case by six inches : thus 3ft. 6in. to 4ft., 4ft. to 4ft. 6in., 4ft. 6in. 
 to 5ft., and 5ft. to 5ft. 6in. The dimensions of the desks are suited to 
 these four heights. The following table gives the dimensions of my 
 desk the "hygienic desk," Nos. i, 2, 3, and 4. 
 
HYGIENIC DESK." 
 
 Height of scholars 
 
 a. Height of seat from floor 
 
 b. Breadth of seat... 
 
 c . Height from seat to edge of desk 
 Height from seat to top of back 
 
 d. "Overhang" of desk... 
 
 e. Play of desk 
 
 f. Breadth of desk (front and back) 
 
 No. i. 
 
 3ft. 6in. 4ft. 
 
 107-122011. 
 
 No. 2. 
 
 4ft. 4ft. 6in. 
 
 122-137 cm. 
 
 I3ins. 
 33cm. 
 
 10 
 25-5 
 
 37 
 
 ii 
 
 28 
 
 8# 
 
 22 
 
 4/2 
 "'5 
 
 No. 3. 
 
 4ft. 6in. sf 
 
 137-152011. 
 
 16 
 41 
 
 9/2 
 
 24 
 
 17 
 
 43 
 
 No. 4. 
 
 5ft. $ft. 6in. 
 
 152-1680111. 
 
 18 
 
 46 
 
 26-5 
 
 41 
 
 Slope of desk i in 5. 
 
 "Its general construction is shown in the foregoing figures. The 
 standards and the cross-pieces which unite them are of cast iron. The 
 back, the seat, the top of the desk, and the shelf beneath it, are of wood. 
 The only points which require description are the book-rest, and the 
 arrangement by which the desk is made moveable at pleasure. 
 
 " The flap which supports the book does not extend the whole width 
 of the desk, but occupies the middle portion only, leaving room for an 
 ink pot to be let into the wood at the side of it. The flap when in use 
 is supported by a small stop which hangs from its further edge, and 
 which, though quite firm, can be pressed back by a touch of the finger 
 when the book rest is no longer wanted. The flap is pivotted in 
 such a way that its near edge sinks below the surface of the desk 
 when the flap is raised, and thus creates a groove for the book to rest in 
 (see Fig. 2). 
 
 "The wooden top of the desk is screwed to two sloping cast-iron 
 brackets which pass from back to front, one at each side of the desk. 
 Each of these brackets carries beneath its lower or horizontal border a 
 round iron rod, the two ends of which are fixed to the bracket. The 
 rods slide freely through holes or eyes on the upper surface of the 
 standards. By this means the desk is able to slide upon the standands 
 in a direction towards and from the scholar. When the desk is pulled 
 forward a notch in the near end of each rod engages with the eye in 
 which the rod slides, so that the desk is secured in this position, and is 
 not liable to slide away from the scholar if he leans against it. By lift- 
 ing the front edge of the desk the notches are disengaged and the desk is 
 easily pushed back, so that the scholar can stand up in his place. This 
 is a mechanism which does not get out of order, and which cannot injure 
 those who use it, or be injured by them. The whole desk can, I believe, 
 be made at a cost not much greater than that of many of the old-fashioned 
 un-hygienic patterns now in use." 
 
Mr. T, G, EOOPEH (H.M, Inspector of Schools) says: 
 i. THE DESK AND BENCH. 
 
 11 1. The height of the desk above the bench should be such that 
 when the child is sitting down he can place both his forearms comfortably 
 on the desk, without raising or depressing his shoulders. 
 
 " 2. The height of the desk above the floor or surface on which the 
 foot rests should correspond with the length of the child's leg from knee 
 to heel. When the child is sitting down, his legs should not dangle in 
 the air, nor should his knees be elevated above the bench. 
 
 " 3. The bench should be wide enough to give support not only to 
 the seat, but also to the upper part of the thigh. It should be at least 
 10 inches (but better 12 inches) wide. To prevent slipping forward, 
 the bench should be hollowed out towards the back to the depth of an 
 inch. 
 
 " 4. Every bench should provide a support for the back of the sitter. 
 This may consist of a board fixed at the back of the bench, at right 
 angles to the seat. The board should be hollowed out in such a way 
 that the upper part of it may lit the concavity of the back. The exact 
 height af the back would vary with the size of the child, but it will be 
 from 6 to 7 inches. 
 
 " 5. The desk must overhang the bench during the writing lesson, 
 in order that the child may be able to sit upright, and at the same time 
 support his back. This posture is only possible when the desk over- 
 hangs the bench from i^ to 2 inches. 
 
 " 6. The desk should not be level for the writing lesson, but slightly 
 sloping. The slope should not exceed an angle of 20 degrees. The 
 difference between the upper and lower edge of the desk, therefore, 
 should be about three inches vertically. 
 
 " 7. As the desk, which is most suitable for writing, is inconvenient for 
 other purposes, the easiest plan of adapting it to all uses is to make the 
 upper part of it moveable. 
 
 "8. Desks of appropriate sizes should be provided for each class. 
 
 2. THE POSTURE IN WRITING. 
 
 " i. The writer should sit upright and should lean his back against 
 the support provided for the purpose. 
 
 " 2. The shoulders should be kept parallel with the edge of the desk. 
 The writer must not be allowed to screw the body round or to rest the 
 chest against the desk. There should be a space of an inch or a little 
 more between the desk and the body. 
 
 
 " 3. The weight of the body should be disposed evenly on both bones 
 of the seat. 
 
" 4- The head should not droop forward, much less lean on the arm. 
 It may be slightly bowed forward and move a little from side to side as 
 the eye follows the writing. 
 
 " 5. The forearms, and not the elbows, should rest on the desk. The 
 pen should be passed across the paper by a movement of the hand and 
 not of the arm. 
 
 "6. The point of the pen should be at least ten inches (better 12) 
 from the eye. 
 
 " 7. To make compliance with the above directions possible, the 
 paper or copy book must lie opposite to the middle of the body. 
 
 8. The paper must not lie square on the desk before the writer, but 
 it must be tilted or askew. 
 
 " The lower edge of the paper and the lower edge of the desk should 
 form an angle of from 30 40 degrees. 
 
 " The paper is rightly placed when the downstrokes are being made at 
 right angles to the edge of the desk. 
 
 " The common attitude for writing often ordered by teachers with the 
 words, ' Half turn right, left arm over slates, 7 is liable to cause injury 
 both to the spine and to the eyesight." 
 
 The MANUFACTURERS of the HYGIENIC DESK claim 
 
 for it a combination of the scientific principles mentioned in the foregoing 
 extracts^ and are confident that it is the best Desk for the PREVENTION 
 OF PHYSICAL DEFORMITY AND SIIORTSIGHT in the necessary cluse 
 application of School Work. 
 
READING & WRITING SLOPE. 
 
 Devised by Mr. PRIESTLEY SMITH, Ophthalmic Surgeon to 
 
 the Queen's Hospital, Birmingham. 
 
 Deal Stained, 5s. 6d. ; Mahogany, 7s. 6d. ; Mahogany, extra quality and 
 
 make, 12s. 6d. 
 
 As used in writing, the slope presents an even surface, 17 inches square, which has a 
 slope of about 1 6 degrees. For reading, the further part is propped up in a simple 
 manner to an angle of 45 degrees ; the act of raising it creates a groove, in which a 
 book will rest securely. In copying from a book, or in using two books at the same 
 time, the two slopes are used together. 
 
 "Our attention has been called to a NEW WRITING SLOPE, designed by Mr. Priestley Smith, 
 Ophthalmic Surgeon to the Queen's Hospital, Birmingham. A bevelled and polished slab of wood, 
 ii X ii, is firmly attached to a stand having a slope of about 16 degrees, and in continuation of the 
 writing surface is a hinged slip 6X17, which is readily convertible into a book-rest so that for 
 
 Review, 
 
 SCHOOL TEST TYPES, 
 
 WITH DIRECTIONS FOR USE, AND NOTES ON 
 
 -e IFreT7-e:ELtiorL of Slxort Sigl 
 
 Price 2s. 6d. 
 
 (Adapted from the " Optotypi ad Visum Determinandum" of Prof . Snellen.) 
 
 The object of these Types is to supply a ready means of testing the eyesight of 
 school children. It is desirable that in every School such a test should be applied to 
 the whole of the children at least once 'in each year. 
 
 Prolonged use of the eyes on near objects, as in reading, writing, sewing, drawing, 
 etc., tends in the case of certain children to an alteration in the shape of the eyeball, 
 and the production of permanent short-sight ; and this, when it has once begun, is apt 
 to increase from year to year, throughout the whole period of School life. 
 
 Short-sight acquired in this way does not at first interfere with study, and therefore 
 advances unnoticed, and attains a considerable degree before steps are taken to check 
 its progress. To minimise the evil, it is essential that such defects of sight should be 
 recognised at the outset, and that precautions to prevent their increase should be 
 adopted early in the school career. The simplest means of attaining this end is a 
 periodical testing of the eyesight. Extract from Preface. 
 
 "The Midland Educational Company, Corporation Street, have, at Mr. Priestley Smith's sugges- 
 tion, printed a Card upon the plan of Professor Snellen for the testing of the eyesight. It consists of 
 a card containing printed letters in three sixes of type. The card is to be hung upon a wall, when eyes 
 of the normal standard should be able to read the smallest letters at a distance of 12 feet, the middle- 
 sized at 30 feet, and the largest at 40 feet. If this cannot be done, it indicates defect to a greater or 
 less extent, which should be reported to the parents of the children. The card is nicely mounted, and 
 is accompanied by all necessary directions." Schoolmaster. 
 
' 
 
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