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Les diagrammes suivants illustrent la mdthode. 32 X i 1 2 3 1 2 3 4 S 6 M PE Autho] i WILLI Manual of Hygiene VOB Schools and Colleges. PREPARED Br TBB PROVINCIAL BOARD OP HEALTH. Authorized by the Minister or Education for u.e m all schools under the control of the Education Department. TORONTO! WILU.4M BElG«s, 78 » 80 KWO STREET EAST, 1886. Entekkd. according to the Act of Parliament of Canada, in the year one thousand eight hundred and eighty-six, by the Minister of Eduction (Ontario), in the Office of the Minister of Agriculture PREFACE. The want has long been felt of a work on Hygiene, which would occupy uu intermediate place between the elementary text-books for the use of children, and the advanced treatises for practitioneis of medicine, sanitary engineers, and other persons intending to become experts in Sanitary Science. Thir. book is designed to meet, in some degree, that want. Whilst many of the calculations, and much of the matter, contained in it are expressed in terras not suited to a child, it is, on the other hand, free, as far as may be, from technical expressions not readily understood by the ordinary reader. Whilst it is primarily intended for teachers, uud for pupils in attendance at the Normal and other Schools of the higher grado it is hoped that it may be read with interest and profit by other persons; and that a perusal of it, coupled with an earnest desire to put in practice any good suggestions that may be offered, will be productive of increased health and vigor, and a lessened death- rate. It is intended to present such a knowledge of sanitary matters as every intelligent citizen should possess. It will be found that the book is mainly devoted to considerations of those matters of Hygiene in regard to which a controlling or modifying influence may be exercised by those for whom it is intended. Such points in Physiology and Anatomy are taken up as will aid in the hygienic considerations referred to : it has been felt that people will be more likely to put in practice suggestions in Hygiene, for which they understand the physiological reasons, than they will mere dogmatic directions. u PBEFACB. The chapters have been written by various members of the Provin- cial Board of Health of Ontario, in such intervals of time as they could find amid their ordinary avocations. They have to thank cer- tain other gentlemen for suggestions in their respective specialties, as well as to acknowledge their indebtedness to the authors of the following works : — Adulteration of Food Reports, Canada; American Quarterly Journal of thn Medical Sciences ; Aitken'a Practice of Medicine ^ *^® Bealeon the Microscope; Burden Sanderson, Works of; Buck's Hygiene- Sea" ' ^'^*^' Dictionary of Hygiene; Bartholow's Eria ^*''Pr^ii?*'''r°''*r^**'^ Meteorological Service of the Dominion of Canada- Corfieid, Lecture on Parasites (English Health Exhibition LiteratTe^ Couher and Uvy, ■ Sur I'occupation dc3 Mineurs " ; Corradi, VaUn and Ziegler Papers read at the Fourth International Congress, Geneva Con necticut State Board of Health Reports, (Paper by the ikte Mr W R Bnggs); Carpenter's Physiology of Temperance and Total AbstiiLce- Cooke, Rev. Joseph, Lectures. ^usimence , Dalton's Physiology and Hygiene; Denison, Dr. Chas., " Health Resorts of the Rockies " ; Dickinson on Albuminuria. r^esorts ot the Flint's Physiology; Flint's Practice of Medicine; Foster's Physiology Fox's Sanitary Examination of Wat ar. Air and Food. ^"ysioiogy , * ox s Hodgins, Dr. ^ G- School Architecture; Hammond's Hygiene; Jlolmes's Kirke's Manual of Physiology, by Baker and Harris. Latham's Sanitary Engineering ; Lincoln on " Ventilation and Warming " and on''SchoolHygiene"; Local Government Board Reports, GreaTBritafn Massachusetts State Board of Health Reports ; Michigan State Board of Health Reports ; Maclagan, Germ IWy of Disease ; Murchison, Obserx atSns on Penods of Incubation, etc. ; McSherry's, "Health and How to Promote It » New York State Board of Health Reports. Pavy^s Food and Dietetics ; Parkes' Manual of Practical Hygiene, edited bv De Chaumont ; Playfair, Sir Lyon, Speech in the House of Commons ^ Registrar-General's Reports England; Registrar-General's Reports, Ontario- Srilcohol. '" ^' Publications; Riant's Hygiene ScolaiL ; Richard.on Sternberg, Raymond, Smart, Vaughan. Leeds, Watkins and Roh.S, "Report of the Committee on Disinfectants of the American Public Health Associa- tion"; Spenser, Herbert, on Education ; Smith, Rev. James, MA Prze Cirrch." ^''"^^'"""''^ Reformation and its Claims upon the ChriSan Taylor's Medusa! Jurisprudence ; The Care of the Teeth, by J. W. White D.D.S.; '^eale, Presidential Address at Huddersfield ' ^^STf^HlgTene.'^"'^'"'""' '^^"''"'' ^"""^^ Drainage; Wilson's Hand- Ziemasen'a Cyclopedia, Articles by Liebert, Liebermeister and Oertel. CONTENTS. CHAPTER I. PAOI Inteoddction: Definition and Objects of Hygiene— Importance of the' bubject— Vital Statistics, and Conclusions to be drawn from them— Examples of the Results of Attention and of Inattention to proper Sanitary Conditions : in the British Army ; in various Cities of Great iiritam ; in India ; in the West Indies-Diminution of Death Rate fol- lowing Sanitary Enactments in England and Wales— Application of this to Ontario— Statistics from the Rr ts of the Registrar-General of Ontario— Comparison of Average Ag j Death in different Occupa- tions—Causes of the Differences g CHAPTER II. The Blood the Pabulum of the whole Body— Its. Composition— The Circula- tion—Changes wrought in the Blood— Respiration— Action of Oxygen in restoring the Blood to a Proper Condition to go again to the Tissues —Means by which Oxygen is brought in contact with it— The Lungs • their Structure— Mechanism and Chemistry of Respiration 7. . 19 CHAPTER III. Normal Composition of Atmospheric Air— Impurities contained in it— Their bources: Respiration; Fires and Lights; Putrefactive Pro- cesses ; Manufactures; Injurious Occupations; Wall-Papers; Ground- Air; Churchyards; Marshes, etc.— Effects of Impurities— Statistics showing them in the Army-Among Teachers-In Hospitals and other Institutions oo CHAPTER IV. Amount of Carbon Dioxide which may be allowed-Amount of Carbon Dioxide resulting from Respiration, from Fires, from Lights, from Sickness-Quantity of Fresh Air Necessary to Reduce these Amounts down to the Normal Standard— Number of times in which the Air in a room may be Changed-Proper Temperature and Moisture of Air- p 1 ^"^ ^P*?!.'^°'i Hourly Supply-Size of Outlet and Inlet Spaces -Relative Positions of these in different Seasons-Experiments of the .late Mr W. R. Briggs-Contrivances for Window Ventilation-Diffu- sion of Gases— Action of Winds— Cowls 33 CHAPTER V. Systems of Natural Ventilation - Louvres - Ellison's Conical Bricks- Sheringham Valve-Tobin's Tubes-The Jacketted Stove -Sta"larS I>«?.^ll.Ceiltng-Potts', and Varl.ys, Perforated Cornices-McKhi nelis Tubes-Watson's Tube-A.'ufidafTeStion-lwinr^^: be Considered in connection with Ventilation— Various Modes ways to of Warming-Stoves-Open Fires-'' GaTtonGra"tr"—Ho^ -Hot Water-Practical Hints for the School-Room ..:........?" 53 IV CONTENTS. CHAPTER VI. rxam Examination of Sufficiency of Ventilation-Measurement of Cubic Air Thrf ''"^*'°" ^l^ Measurement of Outflow and Entrance of Ak ;;7?ii .A^'-^^etfr-The Manometer-Examination of the Condittn Tel ThAh ' ®'"r" '^i'PPle Chemical Tests-Accurate ChemS ^tfi,7 M- T^«^'"?"eter: Plea for greater attention to it-Hygro meters— Microscopic Examination . . ^ygro- DO CHAPTER VII. CuMATOLOOT: Latitude— Altitude— Influence of Temneraturfl TT,-n*« ,„ ^li^k^r''fl7^'' "^'r- "" P^^°*« and'Tntt-HuSt;:: West Coast of Afnca-Malavia-Laws relating to Bodies of Water Location and Soil for School-houses-Hygienic Influence of Soill" Their Chem cal and Mechanical Character-Slope etc?lMarsher Effects of Air m Soils-'' Made Soils "-Humidit? of Soils-Ground" water-Relatn-^ Powers of Soils for Absorbing, Retaining and rS mg Heat-Influences of Vegetation-And of'' Winds-olone-Hearth Resorts of Canada and other Countries neaitn /4 CHAPTER VIIL Disposal of Refuse : Nature of the Substances of which the Refuse of Households and Communities consists - Effects of Non-remov"l or Improper Removal: Pollution of Soil; Pollution of Air; Pollution of Water-Pomts to be secured in the Disposal of Sewage : To remove M Waste Products liable to Decompose or give off Di»,ea:ie Oerml f^ remove them completely before they can Decompose Proper OufklP Proper VentUation of Drains-Examples of Violations oF the above' Principles: Storage of Masses of Filth in Yards and Domestic Col ^ZT'V n r'^' ^/t'" *"^ H^'Ky ^'^''''' ^^^ working throul Drams; Pollution of Streams and Bays; Methods by which Sewer Gas escapes into Houses ; Emptying of Traps by Suction ; Forcin/of Traps; Evaporation of thdr Contents; Sewer Gas Exha ed thr^uuh Manholes and Gullies; Pollution of Drinking Water through Drain and Closet connections ; Po lution of Wells through Soil-Burning of Kitchen Refuse and other similar Waste Material "'"ing or oo CHAPTER IX. Dry Methods of Disposal: Hull Ash-Closet System ; i/ry-Earth Systems- Rochdale Pail- System -Water-Carrlage .System: PreSna7y C^n-' siderations regarding Area, Population, Geological Structure Rainfflll Water Supply, Outfall-Construction oi Drails: Nature WierYal": Shape; Foundations; Joints; Junctions; Fall; Flushing- VentiliHn,^ of Drains ; Different kiads of Traps , Useles^ness of fvaps wSut Veuts-Latnnes Closets, and other Conveniences-Intercepting TaX and Cess-pools-Intercepting-Sewers-Ultimate Disposal of Liquid Re fuse: Sewage Farms; Litermittent Filtration; Irrigation- Precinita tioii ; Hiuumatic Systems— Duties of Trustees and Teachers in recaVd to the Subject of this Chapter; 111 Effects of Neglect ...?!. . . ,^ , gg CONTENTS. CHAPTER X. c Air if Air lition mical PAOI PAai 65 74 Infection AND Contagion : Brief Review of Theories and Facta regarding their Propagation— Brief Descriptions of the various Infectious Diseases — Iheir respective Avenues of Propagation— Periods of Incubation— Duration of Contagiousness -Measures to be taken: Isolation: Pre- ventive Precautions ; Quarantine ; Sanitary Cordons— Saving of Life and Property— Duties of School Trustees and Teachers and other persons— Notification and Disinfection— List of Disinfectants and their Use— Legislation and Regulations regarding Infectious Diseases 118 CHAPTER XI. Clothing: Sanitary Hints as to Material-Shape-Poisonous Coloring Matters— Even Distribution of Clothing— Tight-Lacing— Children bitting m Damp Clothes-Weight of Wearing Apparel and of Bed- Clothmg especially for Young Children -Head-Covering-Shape of Shoes— Deformities of Feet— Infant Clothing , . ....,,, . . 137 CHAPTER XIL Bathing : Structure and Physiology of the Skin-Adjuvant to the Lnnga and Kidneys -Influences of Changes of Temperature-Importance of 11°^^ P^'^.u'^'ll ^^J?. i'emperature-Proper Times for Bathing- The Hot Bath --The Cold Bath-Sulphur Baths-Importance of Help- ing the Pores of the Skm to act properly _ 244 CHAPTER XIII. Poods: Offices of- Proximate Principles— Divisions based on these— Pur- poses served by Foods of each cfass-A Mixed Diet necessary-Diet- aries for Valuing Conditions-Table of Percentage of Compositions of various Articles of Food-Remarks on Farinaceous and Leguminous Foods-Milk-Preparation of Food-Cooking for Conditions of Health and fsickness- Adulterations and Impurities— Their Results— Their Detection , 164 88 CHAPTER XIV. Digestion: Hunger and Thirst— Saliva— 1*^8 Uses— The Terth- Th^ir Structure-Care of the Teeth-Ages at which they appear-Regularity of Meals-Results of Hurry-Eflfects of Cheerful Conversation-Hints ?,ll° ^astication-Mechanism of Swallowing-Description of the Struc- vzzi Bet^^n. f^:'T. . ?! . !'!. :^':::. ^'.t.'^. :!. ."Jr.*!!!: . CHAPTER XV. Alcohol ; Not Needed as a Food-Experiments showing the Fallacy of the Supposition that it maintains a high degree of Animal HearEffects of Alcohol on the Tissues- Alexia St, Martin-Results of Alcoholism- tormation of the Habit -Results-Stati.tics of Alcoholism-Should Teachers be Abstainers ?-Tobacco-Indiscriminate Use of NarcS 180 169 VI CONTENTS. CHAPTER XVI. MOI ^""^rI* -^^a '^^°*'°° and Purposes in the Human .Economv-Ouautitv Required-Sources of Supply-Relative Values o! WaterTfroSDS ent Sources— Contamination of Water- Impure Welk 4w„n «f^ Distribution of Water-Impu ties from pSrPhSalllxSation sri^T«'r"i' '^'^'^' s-eii, aad Touch-cESlrrsr: bimple lests- Approximative Tests-More Accurate Tests-rias«i' Ration of VVaters-Effects of Ciiemical Impurlwes-Purmcatfon of \Vater: by Precipitation, by Filtration, by Othe/ Modes-F Iters Ifteir Use and Abuse-Filters on the Large and SmallSes-Hvat"; SchoorHZr '"'"°"*" "^ *° '^^^P^^e W^*«^ ^ andlbourfhe' 192 CHAPTER XVIL Hygiene op the Eye: Structure of the Eye as an Optical Instrument- ofX" AcSon'oTS TJiTr ^' \^ ^'"^^ Spot-ExTaSons Far ^lahr « • *• ^y«-l^?|ect8 m Vision Explained— Near- and *ar-Sight-Squmtmg-How Defects may be Remedied-Action of Lenses, etc.-Hints as to Preservation o/ Sight-Ca7e of the Eves in Infancy-Increase of Short-Sight in late years-Pro^r Modes of St mg Rooms-Hints to Teachers, Pupils and othe^rs-^mportam^^^^^^^^^ good Type and Paper-Reading by Dim Light-Blinds raisS from below-Quack Applications-Color-Blindness . . . . ...?;.. , !! , ..." 211 CHAPTER XVin. Hygiene OF the Ear: Its Anatomy and Physiology-Hints as to Use and Abuse of the Ear-Exposure to Draughts-Catarrh resulting!! Inflammation-Ulceration-Perforation of the Drum-Deaf mutS Wax. Insects and other Foreign Bodies in the Ears-BoxStrFarTl 5' Chi d/'^^'ter *° ?^'T/^« ^^"-^^""y *he Condition^f HeanW of Children-Children often Blamed Wrongfully, when their Short comings have Resulted frcin Partial Deafness . . ... .":...!. . °^; 226 CHAPTER XIX. School Furnitdee: Scrapers and Mats-Lavatories-Hat-Hooks-Adan- tation of Desks to Pupils-Deformities Caused by Neglect-Proposed Adjustable Seat and Desk-Change of Position-Blinds-Blackffiards -Drinking Vessels-Thermometers-Ornamentation -!:_..! 232 CHAPTER XX. Physioal Exercise: Structure and Physiology of Muscle-Walkine- Leapmg-Running-Football-Lacrosse-B^eball-Cricket-SM rtMrr"^~A"f°'*-^*^i-P"7'°«- Sailing-Rational and IrratSI Athletics-Action m Producing Diseases of the Heart, Luncs Limbs ete,-Gymnastic8 and Calistheni.s-Recreations : for Summer -fo; Winter; for Qirh; for P^ys-Altemation with Mental Srdse!! Recesses -Kindergartens 7,\ ...!.... 238 CONTENTS. CHAPTKR XXI. vH PAoa XnH- "t^'"' Mutual Pependence Of the Physical. Mental and Moral t acuities -Developnient cf the Brain-Over-pressure- Competition- Hurry and Worry ^Their Results-Opinions of Eminent ATtWSsZ bchool Age-Age of Puberty-Sensational Literature-Half tir^elys- l^ImZTy^L.^"''\W^'^'^-- «'"*^ ^« *° these; also aa to or bv Fnn irv K^r t"'''!*^ ^^ ^'''^'' '' ^''""^'l ^^ Tested Practically betwee^ Ss^Res'; ^I'fil ""^°",? Parents -Change and Jlecreation T lasKs— Kest and Sleep— Deductions from Vital Statistip« Increase of Diseases of the Nerv'ous System-Increase of Suicide .~ 248 CHAPTER XXII. ^"TSio^n" nJ''''*'"'"V^ ''■'''^''''' ^"^ Emergencies-Fainting- buBocation-Drowning-Hangii.g-Choking-Iniurious Gases-Snn ?;ot^7tl'XroVAP""V^;^'"i '' Hlce^lingiBira anricalds- Pvo ^ n ] iM^ ^"'""*ls-Cinders and other Foreign Bodies in the Eye-Falls and Blows -Shock-Fire-Escapes-Fire-Drill ^° . . . . . 254 Page of Test Types 271 List of Illustrations . 27a Index ' 277 p ai ai C( fr w ai cl si in m fo th fei ■wj ce ii^ si( ■wi MANUAL OF HYGIENE. CHAPTEE I. DBPINITIONS AND OBJECTS OP SANITARY SCIENCE — EXAMPLES AND STATISTICS SHOWING THE RESULTS OF IMPROVED SANITARY CONDITIONS — VITAL STATISTICS. 1. Hygiene may be defined as the science which treats of the preservation of life and health by the application of scientific laws to agencies and things in common use. Great and unnecessary waste of life, health and vij,'or has resulted, and still results, from a neglect of scientific principles in regard to common things. There are many of these, such as the amount of fresh air and breathing space in our dwelling-rooms, school-rooms and work-rooms, the disposal of the refuse of our households, the position and condition of wells and other sources of water-supply, bathing, clothing and other matters, which appear so trivial, common and simple to people in general, that they do not consider the aggregate importance of slight differences in regard to them ; and yet these little every-day matters largely affect life and health. 2. The scope and objects of Hygiene are by many persons con- founded with those of the practice of medicine, the feeling being that the study of all matters relating to hygiene may be relegated to pro- fessional men. Now, whilst it is unwise to attempt to treat disease without the advice of those who have made a special study of it, it is certainly not unwise to endeavor to understand and practice the order- ing of our daily lives and surroundings in such a manner as to avoid sickness and to maintain the highest condition of health. Nor is it ■wise to await the onset of disease and the arrival of a physician before 10 MANUAL OF HTOIENE. remedying unsanitary conditions which may render his best efforts unavailing. In like manner, whilst we may err in neglecting the advice of the architect, the engineer, and the chemist, we should our- selves understand the elementary principles of hygiene as it is con- nected with their professions; otherwise we sliall, to the great detri- ment of health, overlook even the occasion and necessity of seeking their atlvice. 3. Some idea of the importance to us of carrying correct sanitary principles into practice, may be obtained by considering what has been gained by increased attention to even a few of them in certain instances in which we have reliable statistics to inform us of the results. For example, b^ adding the columns of population and deaths as given on page 243 of the "Statesman's Year Book" for 1883, we shall find that the average death-rate for the six years prior to' the passing of the Public Health Act of 1875 was, 22.09 per 1,000, and for the six years following the passage of that Act it was 20.63. ' The total saving of lives effected in six years was 219,118. In England and Wales alone, there were saved a number more than twice as great as that of the British army for the same period. The figures quoted are from one of the most accurate statistical records in the world • and this great decrease of the death-rate has taken place notwith-' standing the fact that as years have rolled on the population has been growing more dense. 4. The Sanitary Reforms by which this result was achieved were in general terms, the cleansing of premises, both private and public,' the establishment of correct systems of plumbing and drainage, the improvement of water and food supplies, and greater care regarding the isolation of cases of infectious disease. These reforms were the more strictly and generally carried out through the agency of local boards of health, which by the Act referred to were extended to dis- tricts which had hitherto been without them; but they were in the main executed by individuals in their own households. The distinguished sanitarian, Mr. Edwin Chadwick, stated before the British Association a few years ago that both the sickness-rate and the death-rate of Great Britain had been reduced one-third by the practice of sanitary laws; that in many parts it had been reduced much lower; and that it is his beUef, from what has been demon- MANUAL OF HYGIENE. 11 strated, that with a more perfect system it may be reduced by two- thirds of its former rate. 5. The number of recorded deaths in Ontario in 1882 was 21,800. Applying, then, Mr. Chadwick's calculations to this Province, we can form some idea of the saving of life that may be effected by a proper knowledge of sanitary laws. It is needless to say that no money statement can adequately express what this saving of life means. No words of ours are neces- sary to add to tlie feelings of any right-minded person regarding its desirability from a humane, social or religious standpoint. Neverthe- less, the question has its financial aspect, and statistics in regard to this may be of some value. The money-saving ultimately possible in this Province, as based on the statements of Mr. Chadwick, ia com- puted at 19,540,000 per annum. 6. When a virulent epidemic, such as cholera or small-pox, threatens the community, what alarm and activity are manifested ; and yet more deaths are caused yearly by the want of means for securing thorough cleanliness of streets, lanes and premises, good ventilation, effective drainage and ventilation of drains, good water-supply, isolation of infected persons, and careful disinfection, than have ever been super- added to the ordinary mortality by any epidemic of cholera or small- pox that has occurred in modern times. 7. From the Reports of the Registrar-General of Ontario we find that in the year 1881 the recorded deaths from diphtheria were 1,171 ; from scarlet fever, 470 ; and from all those diseases which are readily admitted to "spread" from a first case there was a total of over 3,000. The question having been asked of a number of medical men whether they thought one-half of the cases in their neighborhood could have been prevented if proper sanitary pi-ecautions had been observed, the answer invariably wa^ that a greater saving than that might have been effected. But let us content ourselves with assuming that one- half might have been prevented; this will give us 1,500 persons who might have been saved from death by contagious diseases. Consider along with this how many of the 2,397 persons who died in that year from pulmonary consumption might still be alive if better ventilation had been mlopted. Add to both these, the numbers who might have been saved from death from filth di^ es and from accidents pre- 12 MANUAL OP HYQIKNE. ventable to a certain extent by proper regulations, and to this again add the numbers of sick who did not die, and we think there will be enough to convince the most unprogressive of the urgent necessity for greater attention being paid to sanitary science and sanitary art. From subsequent reports we find a diminution in the number of deaths from these communicable diseases, the totals obtained being 3,033 for 1881, 2,821 for 1882, 2,143 for 1883, and 2,073 for 1884. 8. The records of the army service furnish some jtriking examples of the diminution of the sickness and mortality rates on account of im- proved sanitary conditions. Owing to the discipline and uniformity that exist, changes, when ordered, are strictly carried out, and statis- tics are accurately given, so that statements of the results of altered sanitary conditions in the army may be relied upon. In India, where the mortality used to be very great, a marked diminution has resulted, as may be seen by the following table taken from De Chaumont's edition of "Parkes' Hygiene": Mortality of Europeans pee 1,000. 1845-50. (Chevers) 1838-56. (Queen's troops alone. Balfour) . , 1 806-56. (East India Company's troops aloaec Indian Sanitary Commissioners) 1860-69. (Ten years. Balfour) 1870-79. (Ten years. A. M. D. Reports). Bengal Presidency. 63.38 79.20 74.10 31-27 20.17 Bombay Presidency. 60.20 61.10 66.00 22.58 16.37 Madras Presidency. 59.20 62.90 63.50 22.53 18.97 The reasons for this diminution are thus stated by Dr. Parkes : "After the mutiny, about the year 1860, the sanitary improvements and the greater care of the troops, which had been gradually taking place, received an immense impulse. The results are shown . . [above]." 9. The West Indies also used to be very unhealthy for troops. The names of certain of the stations are familiarly associated, in the minds of some, with painful recitals of death and disease; and this was attributed to " the climate." Of these islands Dr. Parkes thus writes in his work on " Practical Hygiene " : — "The history of sanitary science affords many striking instances of the removal of disease to an extent almost incredible. Formerly service in the MANUAL OF UYGIENE. 18 West Indien was looked on as almost certain death. It is little over sixty yenrs Bince the usual time for the disappearance of a regiment 1,000 strong was five years. Occasionally in a single year a regiment would lose 300 men ; and there occurred from time to time epochs of such fatality that it was a common opinion that some wonderful morbid power, returning in cycles of years— some wave of poison— swept over the devoted islands, as sudden, as uulooked for, and as destructive as the hurricanes which so sorely plague the "'Golden iales set In the silver sea.' "At present this dreaded service has almost lost its terrors. There still occur local attacks of yellow fever, which may cause a great mortality; but for these local causes can be found, and otherwise the stations in the West Indies can now show a degree of salubrity almost equalling, in some cases sur- passing, that of the home service. " 10. The causes of the production, and the reasons of the cessation, of this great mortality are described at great length, and the latter are then summarized as follows : — "Among the measures which have wrought such marvels in the West Indies have been — Ist. A better supply of food ; good, fresh meat is now issued, and vegetables, of which there is an abundance everywhere. 2nd. Better water. 3rd. More room in barracks, though the amount of cubic space is still small. 4th. Removal of some of the stations from the plains to the hills 5th. Better sewage arrangements, and more attention generally to sanitary con- eervancy. 6th. A more regular and temperate life, both in eating and drinking, on the part of both officers and meu. 7th. Occupancy of the unhealthy places, when retained as stations, by black troops. 8th. Better . . . [and] . , . more suitable dress." In his detailed description Dr. Parkes traverses many avenues in the domain of liygiene, showing the ill-effects caused by a violation of its principles, and the beneficial results of sanitary reforms. 11. That these same violations occur amongst ourselves, sometimes in less degree, someti)nes, unfortunately, not so, will be seen in the following chapters. We have in our dwelling-houses, our schools and our factories instances of over-crowding and want of ventilation as bad as those to which Dr. Parkes alludes. Our modes of disposal of refuse are in most places quite* as imperfect and revolting, and act in the same way in producing the typhoid fever that is so prevalent. That ■we are not scourged to the same extent, as the result of our uncleanli- ness in this respect^ is due to the fact that yellow fever does not live 80 far nor Ji, 14 MANUAL OF HYQienib. Wany cases of Typhoid Fever f^ u ^- - a. the present tCLT^^rX!^ ^^^^ *H.„gHout this yea.. .^0, no oa«es had occurred. Ue^l ' *'"' "^^'^'^ "^ twenty o ::;o:fr"^ ""^" *'^«^ -^ ^ « "?: :r r^^^^ ^-- ^' Hunnl "* ««^%'e-disposaJ and thn ^ ''^^''*^°'»« l>etween ^'"Pply wo must look for thL , surrounding air and » T The errors in diet 1 '^P^*"^*'o«- "^ ''*'''- proper food,s^descrild ttrT J" "*^"^' ^"^ ^'^^ -ting of im °"r oountry; and strong dn^k ^^'^'"'^^ ^^ "«* -ithout pLalle,Tn" J'^rgo nun^her of deatJ.s Tot "-^^P^^^ible here, too for a the fo]W,„g chapters. ""^"^^ l^«^"t« vviJ] be considered in '/• '"e reduction of Tvnhniri c v^'ater-suppiy has been leH^?' , ''"" "^ •"'P''oved seweraa. « . -tain cities, statistics re^Lt?:;:;:^ '"^"^^"^ ^" the hS J^o Capt^DouglasGalton before theSn T' «^^^" ^^ -« addre s bv 'ts fifth annual meeting, lot h ""^ ■^"■*"*^ «^ ^Jreat Bri^n !t Registrar-General of Ontal k ''"'^''^^ '^"^ the Report .f„ ' TJzt ''' '''^^^^^7:.ri::n^^^^^^^ *^« tab^hicf: ; aeatns from tvnhnir? t^ • " °^ seen thaf fi,« , *^„ ii "/pooid fever in the fJ,..^^ i the records nf At IS to be hoped that «f „ •^'.'o^ement has commenced in ., basis «?V ' ""'''''* '""ve recentlv 1,: ''""'""tion of the «-A' 7 ^ ^ier-worlro o»« L • "Ulcers nave been ( Pnvypita. Efforts being (fljw^ ^roughout this een or twenty itaJity from it tions between »r and wator- eating of im- t parallel in I for a very id mortality >ssive brain- ent exercise the proper of the eye- ' genora] to nsidered in erage and listoriea of address by Britain at rts of the ^hich will ecords of Province ■he Euro- « cities. ' sewage i out as of the a fresh '6 been 1 these health heuig MANUAL OK IIV(iIENE. made to havo skillt'd inspection of plumbing and ho(is<> diiiiim;,'c in Hamilton a crematory Iihh been ««ieiU'(l fur burning n-func. Cixr. Frankfort- ontlie-Miiin. Dantisiu . Munich, Toronto . , , Hamilton ... London , { Perial. .Sanitary Condition. 1854-50 186r)-6» No Heweiiigc, , No sewerago; no proper W!itor-8iip- ply- 1881 1882 1883 1884 1881 1882 1883 1884 1882 188.3 1884 3 a a. 4) ' o e5 ^ 12 •" _ «> » « i S -o -g 5*j m a." ^ c ceo •= * o a c3 j: 87 108 ISM-GD Absolutely no 242 regulations for koep- iiig the soil clean. 74 69 80 65 65 47 30 41 10 52 65 I'urlod. (,'lmnKPH In Sonl- tary Conclltloii. 1875-80 Seweragfconi pleted. 1871 75 Water nupply introduced. 1878 80 Sewerage add- ed. 1860 65 ReforniH be- gun by CO Uienting tlic sides and bottoms of cess-pits. 1866-73 Partial sower- 1876-80 Sewerage im- I proved. 1881-84 Sewerage still further im- proved. 15 ; "lid i; S b° ■3 _ * 24 00 18 168 133 87 17 16 MANUAL OF HVGIENE. 13. Statistics of cities which are remarkable examples of the results of sanitary improvements in reducing the total death-rate are also ^ven by various authorities. In Newcastle, according to Capt. Galton the death-rate has been reduced by such improvements from 27.6 per 1,000 m the quinquennial period beginning in 1868 to 23 in the quin- quennial period ending in 1881, wliilst in 1881 it was only 21 7 In Birmingham there lias been a remarkable reduction in the number of deaths from diphtheria and typhoid fever. In one of the English blue books we find a record of the diminution of tlie death-rates of twelve of the smaller towns in which improved systems of sewerage and water-supply had been established, which is well worthy of bein- reproduced, and which should claim our attentive consideration •_ ' PLACE. Banbury . Cardiff ... Croyden . . . Dover Ely Leicester . , Macclesfield Merthyr. . .. Newport , . Rugby Salisbury . , Warwick . . Average mor- tality pe 1,000 be fore con- struction of works. 23.4 33.2 23.7 22.6 23.9 26.4 29.8 33.2 31.8 19.1 27.5 22.7 Average mor- tality per',. 1 ,,.. 1,000 since •^''^'"»°fl''ff completion I of works. I per cent. 20.5 22.6 18.6 20.9 20.5 25.2 2,3.7 26.2 21.6 18.6 21.9 21.0 l'2h 32 22 "7 14 4i 20 18 32 2i 20 7i Reduction of Typhoid Fever. Kate per cent. Reduction in Kate of Phthisis, per cent. 48 40 63 36 56 48 48 60 36 10 75 52 41 17 17 20 47 32 31 11 32 43 49 19 14. The Vital Statistics of our own Province furnish us with many facts of great importance in a hygienic point of view. A study of these would prove very interesting, but we will only have space to take up m this connection one line of investigation in addition to the refer- ences to our statistics which have already been made. The tables of "Deaths by Occupations," in the Reports of the Registrar-General of Ontario for 1882 and 1883, inform us of the average ages at death of persons who were engngod in various employments. Some of these figure* are well worthy of note as showing the results of unsanitaiy "J I iples of the results eath-rate are also ig to Capt. Galton, nts from 27.6 per to 23 in the quiu- as only 21.7. In in the number of e of the l^nglisli ;he death-rates of tems of sewerajre I worthy of being isideration : — uction of Reduction in 'phoid K 11 1 e of ver. Kate Phthisis, r cent. per cent. 48 41 40 17 63 17 36 20 56 47 48 32 48 31 60 11 36 32 10 43 75 49 52 19 sh us with many w. A study of ve space to take ion to the refer- The tables of strar-General of ages at death of Some of these s of unsanitary MANUAL OF HYGIENE. 17 conditions co-existing with certain occupations, most of which condi- tions are capable of being remedied. We give a few examples :— Averoffs Age at Average Am at . Death in 1882. Death in 1883. "inters 3231 335 Seamstresses , _ _ ^ 32 70 42 2 Milliners and Dressmakers 36.81 43 6 Chemists and Druggists 36 84 4Q 7 ^^^^^ra 37gQ ^jg Railway Employees 33.86 33.6 Mark the short average duration of life as compared with the following : — Averajre Age at Average Age at Death in 1882. Death in 1883. Gardeners 64.5 62.8 Hunters and Fishermen 62 8 50 F'^i'™«™ .'.' 6L4 62.2 Clergymen 60.5 56 Farmers' Wives 53.8 69.7 Contractors and Builders , . . 5^ 4 g^ g 15. The special causes of the vitiation of the air of printing offices will be referred to in a future chapter. The results of close indoor employment in air rendered impure from various causes are sharply contrasted, in the first five employments mentioned, with those of the outdoor life of gardeners, farmers and builders, and the more varied life of the clergyman; whilst the statistics indicating the term of life which falls to the lot of her who sits, " With fingers weary and worn . , , Plying her needle and thread," do not beUe the popular belief regarding the life of the seamstress. The relative longevity of the stonecutter, inhaling the dust which he throws into the air, (47.63 years,) and of the stonemason, (64.30,) are very different, though both live out of doors during a great deal of their time. The above figures do not diifer materially from those given in a « Review of the Deaths of the Last Decennial Period." 16. Statistics which might mislead us regarding certain QccupatioRK have been purposely omitted in our illustrations. For instance, the average age of female teachers, calculated from the deaths for 1882, 18 MANUAL OF HYGIENE. would be a littlo ovor 36 years, and that of male teachers nearly 75. Whilst there are iiiHuences which cause a greater deterioration of health among female tlian among male teachers, we can hardly sup- pose that the diliereud- is so great as these figures might seem to indicate. Is it not a probable explanation of the excessive disparity that after mari-iage females more commonly give up the vocation of teacliing than do males, hence there are fewer female teachers to die old ? On the other hand, we may point out that this does not at all detract from the force of the remarks in a subsequent chapter re- garding the ventilation of school-rooms ; for whilst the total deaths of all persons between 30 and 40 is 13.')9, and the total deaths from phthisis at tliat age 440 -a proportion of 1 to 3.08— the proportion worked out for female teacliers (for wliom the average age is given as 36) is 1 to 2.2.^); or, taking another compai-ison, wln'lst tlie age at death of female teacliers is the same as tliat of female servants, the death-rate from phthisis of the former is 1 in 2.25 and of the latter 1 in 6.5. In other words, whilst the total death-rate of female teachers may not be unfavorable as compared with that of some other classes, the deaths from phtliisis amongst tlie former is out of all proportion; it is even greater than that of printers and stonecutters (of all ages,' however). 3 nearly 75. jrioration of hardly sup- ?ht seem to ve disparity vocation of icliers to die s not at all chapter re- ;al deaths of leaths from proportion ! is given as the age at Brvants, the the latter 1 ale teachers ^her classes, proportion ; of all ages, Hg.l. Circulation of theBlood. TheCopp Clorl^Car'imitfd.Toronfo, CHAPTER II. THE BtOOD— COMPOSITION, USES, CIKCULATION, AND AEUATION OF. 17. The Blood is an animal fluid, formed chieU/ from tlio chyle, and acquiring important properties during respiration. It enters every organ through the circulation, distril)utes the nutritive princi- ples to every tissue, and is the source of every secretion. Human blood, flowing from the body, is a thickish, heavy fluid, of bright scarlet color when it comes from an artery, deep purple or neady black when it flows from a vein. Its specific g.'avity at 00° Fahr. is on an average 1055. Its temperature in health is generally 100° Fahr., and it has a slight alkaline reaction. Blood taken from the body and left to itself in a vessel separates into two distinct parts— the serum, or watery, supernatant fluid, and the coayulum, or clot. 18. Chemical analysis shows the average p.oportions of the principal constituents of the blood in 1,000 parts to be— Water ^^^ Red blootl cells , oi Albumen of Keruni \j^ Saline matters ..\„ Extractive, fatty and other matters ^^'^'n Fil^rine .............! 2. 2 1,000 19. Blood-cells are of two principal forms, the red and the white of which the hitter are in process of being developed into the f rmer ' and this mode of development continues throughout life P:very new white blood-cell forms itself in and from the materials of the lymph and chyle, and is perfected in the blood ; and the blood is maiutained by constant repetitions of this process. The human red blood-cells are discs of diflerent sizes, appea.^ing und,.r the mirroscop,. like tiny rolls of coin. They are composed of a u.embraneous cell wall which encloses a peculiar substance in.pregnated with the red coloring matter 20 MANUAL OF HYGIENE. or hseraatine. Hsiematine contains 6.04 per cent, of iron, in the form, most probably, of the simple element. It is distinguished from all other animal bodies by its blood-red color. This peculiar color does not, however, depend on the iron ; for ha-matine may retain its color aftei all the iron has been extracted from it. Therefore the changes produced in the color of the blood by respiration, to which allusion will be made further on, cannot be ascribed to any changes in the condition of the iron in the ha^atine. They are probably due to the fact that the oxygen, by first contracting tlie blood cells and thicken- ing their -Us, makes them so reflect light as to appear, in mass, bright red; and carbon dioxide, on the contrary, by dilating tliem and thinning their walls, makes them reflect less light, and appear, in mass, nearly black. 20. Fibrine appears to be developed commensurately with the blood- cells, and in like manner is perfected in the blood. The coagulation or clotting of the blood is due to the organization of its fibrine, and mdicates a capacity for developing and acquiring higher organization in conditions favorable to life. 21. Of the Inorganic constituents of the blood— the substances which remain as ashes after its complete burning— one may observe in general that they are small in quantity in proportion to the animal matter contained in it. Those among them of peculiar interest are the phosphate and carbonate of soda and the phosphate of lime. In illustration of the characters which the blood may derive from the phosphate of soda, Liebig points out the large capacity which solutions of that salt have of absorbing carboi dioxide, and giving it off afain when agitated in atmospheric air and when the atmospheric pressure is diminished. 22. The fatty matters which are found in the tissues or secretions exist, for the most part, ready formed in the blood ; for it contains the cholesterine of the bile, the cerebrine and phospliorized fat of the brain, and the margaric and oleic acids of common fat. The quantity of the fatty matters in the blood varies, being commonly increased after each meal in which fat, starch or saccharine substances have been taken. 23. The water of the Blood varies from hour to hour in its quantity, according to the period which has elapsed since the taking of food or I Manual of hygiene. il , in the form, shed from all ar color does tain its color e the changes Inch allusion langes in the •ly due to the and thicken- ear, in mass, lilating them nd appear, in Ith the blood- e coagulation s fibrine, and organization e substances may observe » the animal interest are of lime. In ve from the ich solutions it off again jric pi-essure or secretions contains the I fat of the 'he quantity ly increased tances have its quantity, J of food or ^ drink, the amount of bodily exercise, the state of the atmosphere, and all the other events that may affect the ingestion or excretion of fluids. According to these conditions it may vary from 70 to 79 per cent. Uniformity is, however, maintained, because whatever tends to lower the proportion of water in the blood, such as active exercise or the addition of saline or other solid matter, excites thirst ; whilst, on the other hand, the addition of an excess of water to the blood is quickly followed by its more copious excretion in sweat and urine. 24. The resemblance of flesh and blood, so far as their chemical composition is concerned, is so great that the blood has been aptly termed "flowing flesh," and the results of the ultimate analysis of the blood and of the flesh of the ox so resemble each other that the ele- mentary composition of their organic constituents may be considered identical, and may be represented for both as carbon 45, hydrogen 39, nitrogen 6, and oxygen 15. 25. The purpose of the Blood appears to be threefold. First, to provide materials suitable for the nutrition and maintenance of all the parts of the body ; second, to convey oxygen to the several parts, whether for the discharge of their functions or for con)bination with their refuse ; third, to bring from the same parts this refuse and convey it to where it may be discharged. The first is the primary purpose of the blood, but the second and third are essential to life, and will be more especially considered hereafter. 26. The circulation is the means by which these various purposes are accomplished, because it is necessary that the blood should be con- stantly moving through all the parts nd, at certain periods, should be exposed to the atmosphere, in order that it may absorb oxygen and emit carbon dioxide, water and other waste matters. To this end it IS provided in man and all warm-blooded aniraals, that all the blood, which has passed once through the several parts of the body, shall traverse the lungj and be exposed to the atmosphere before it again takes the same course. The course through which the blood moves, in order to accomplish this object, may be thus described, 27. The general circulation (Fig. l) commences at the left ventricle of the heart llv), blood being impelled into the aorUx. (no) and along its successive branches, the systemic arteries (a, a, a, a), through which all the organs of the body, except the finer textures of the lungs, derive 22 MANtTAt OF ftYOfENR. ( »-^. - and 3), tl,e uimute ve^ek wl.id. Jie mtau.edmteiy organs. From tliese it passes intn tJ,o , • ^ s,uljstance of tl.e \ ii . passes into the systemic veint (V?\„ ^ vc), tlirough tl.e inaiu trunks of avI.k.I. fl.„ ,' ^ " ' '^' "' ''' heart/ This c±ti^^^^^^ * '*^ -^/.^..n^Wc/« (..), of the circulation. ^ "^''"'"^ circulation, or general part of the branches, in the l^ngs e^prd", ,^ ' r^''' "'""^ ^^> ""' ^*« MANUAL OF riYOIF.NE. ito the nyntemic interiiiediateJy 23 of the cir:ulntion : the blood cor- iteiy, (c,-) capil. oiiiiective tissue. h the blood fince of tlie i,'- 1, V, V, V, it flows into [rv), of the part of tJie /it ventricle >«) and its .s', in whicli From the rough tlie ti-aversed wliere, in 29. The color of the blood in tin- l,>ft ventricle is bri-ht scarl(>t bmng arterial, and d.ar^^-d with uxy.,n in greater proi.ortio.i than carbon dioxide, as well as with the nutritive materials before r.-ferred to. So it remains in all the systemic arteries ; but in the systemic capillaries it parts with portions of those materials, and its oxygen is largely consumed in uniting with the hydro-carbons and other sub- stances, which enter the blood-v.-ssels as .(.fuse from the various tissues. Thus the blood ac(,uires a dark venous character, and in this condition It passes through the systemic veins, the right side of the heart and the pulmonary artery. In the pulmonary capillaries, how- ever, emitting carbon dioxide, water and organic matter, and tak- ing up oxygen, ,t becomes again art<>rial, and so passes on to the left ventricle. 30 The principal force used in producing this constant movement of the blood IS that of the muscular substance of the heart. Other assistant forces are those of the elastic walls of the arteries, the pressure of the muscles, among which some of the veins run the movements of the walls of the chest in respiration, and perhaps, to some extent, the interchange of relations which takes place between the blood and the tissues in the capillary system. The average time in which the blood completes its entire circuit in man, is less than one minute. 31 The right direction of the blood's current is maintained by valves placed between each auricle and ventricle of the heart, at the oriHces of communication betwen the ventricles and the main arteries, and in n.ost of the veins. These valves open to permit the movement of the blood m the course .,ust described ; but close when any force tends to move it m the opposite direction. 32 Respiration is closely allied with the process we have just described. It has been already stated that one principal object of the circulation is to collect the various impurities, derived from tissue waste, and in part also from the elements of unassimilated food. These Znctr f H """"' '^ """" '' ^""-^'"-^ °'-«^^-- One of the most abunckntof these impurities is carbon dioxide, the removal of which and the introduction of fresh quantities of oxygen, constitute the chief puiposes of respiration. Respiration i„ ,„,. and in all mammals is earned on ni the minute cavities in the lungs called air-cells 24 MANITAL OP HYGIKNR. i'i"„ {tig. 4) consists of a collection of such -— ===^~^ an-,.el)s, clustered upon and openin. !" " """"*" ''••'^'"'J'-'* -f the bronchial tuH.s, and having their walls overlaid wih capillaries, derive,! fron, the ternii- ;;' '^'''-''r ^^ *^'^ P«lmonary artery, rhe bronchial tube belonging to eacl. lung passes into its substance, di.idinr. and subdividing, and sending branches to every part of the organ. ^Fi^, 5 ) 34 The larger bronchi havo^walls forn.ed ot tough nu.nbrane, with or- ^uuc-mnsc„Iar, circular fibres, giving ce^:- *-r."Two"sman .roup, o, air I ^ ^"^''' ""^ '^P'^»t^n«o"s contrac- tutriStt-ll -^;;;^^i -; Por^ns of cartilaginous rin.s, ^ .ell. by Winch they arok.pt open; and lon- gitudi..a/ bundles of elastic tissue, for greater power of recoil after extension. They are lined with mucous membrane, the suiface of which, like that of the tra- chea, is covered with vibra- tile ciliary epithelium. /Fiff 6.) ^ ^' 35. The smaller bronchi are not provided with the structures above referred 1%. ^•-<>""^-^-e^^„n^, wu^^^^^^ ,.,„;:Xc.ea i^tlT "'.•?. "lu'K.-hial tubo, sliow- J- Each lobule 'llootion of such 11 and openin;:( f the bronchial ■ walls ov(;ilaid t'loiii the teriiii- nonury artery. )iigixig to each iaiicc, diVidiiijr ding hrttnohes n. (Kii^5.) ^i havti walls aue, with or- fibres, giving leous contrac- ginous rin'r.s, 3en; and lou- [Ues of elastic ■cater power ii" extension, with mucous B surface of it of the tra- \ with vibra- lelium. (Fig. iller bronchi sd with the ^e referred MANUAL OF HYGIENE. 25 the mucous tube, sliow- jrfatG of the the left ia a nified to They are formed ..f a tough, elastic me.nbrat.e with traces of hbrous structure, over which the capillaries are spread in a very dense network, and on various parts of which air-cells open. These tubes have been called inter-cellular passages. The air-cells openii,.. into them may be placed like recesses on their walls ; but more often they are arranged in rows like minuter sacculated tubes, so that a senes of cells, all opening into one another, open by a common orifice into the bronchial tube. The air-cells are of various forms, their walls are nearly m contact, and they vary from ,U to ,.},, of an ir.ch in aiameter. 36. The pulmonary capillaries form a network of vessels outside these air-ce Is, so very close in its nature that the interspaces are narrower than the vessels themselves. Between the air in the air-cells and the blood m the capillaries, nothing intervenes but the thin walls of the air-cells and capillaries and the delicate epithelial lining of the fonner The exposure of the blood to the air is therefore complete, because the folds of membrane between contiguous cells, and often the spaces between he walls of the same, contain only a single layer of capil- laries, both sides of which are thus at once exposed to the air 37. The movements of respiration are two-fold. The movement for taking frcsli air into the lungs is called insjnration, and that for .xpelhng the air which has been changed by the respiratory process, exp^rat^on. Inspiration is performed principally by the action o certain muscles attached to the exterior of the chest (p, sm, Fig 81) • expiration by the recoil of the lungs and the walls of the hesf af ; they have been dilated, aided by muscular action also 38. In Structure the chest is a cavity dosed on every side from the entrance of the air; its immediate boundary is formed by its lining niembrane, the pleura; its walls external ^ the pleura, are partly elalic It^'fin ;'; ''r^"' "^^'^'^^' P^^*^^ --cular,'and partly file ,r ,1 ^ *'" ^""*"^' '^^^* ^°^ ^^^g- ---'«. -d these fill It equally in all its alterations of size; when it enlarges they o thir"?;i 'f "' ii "'^" '' ^^'^^'■^^*^ ^^^ -d blood pass out of them; and the lungs and part of the heart are always in contact ceUs of the lungs; and through their medium the pressure of the atmosphere is communicated, through the windpipe, to the whole of 28 MANUAL OP HVaiENE. t'lfl intorlor of tlit> cavifv ,.f fi i 39. The mechanism «l n^Z^TTi 7' '"•'"'' ''"'"•"x- tl"" of llK, air on tl,o,> i„t„ ™ .° , '""S" "• "™"'"1'"' l-« >!,„„ enteric,,. t,„„, „„ the iuterioU 1 " ' '" "7"r " «-™'«- »" «- through tho wi,„lpi,,o, the It „, ,,. '^ ,"", ""' " '"'"■'' """■' """" «l.o.ti,.ity ,.f the l,„,l. "'"» ""'*"'• "» «■■■» »t».e,l, U, t|,„ act of ordinary tr„,„ „n |,r„lthi I "'^ '" "'" '""»■'• '" «* ■""..I^or of re,pirati„„, iu a Chv adu '' " ™'"" '""'"■«■ 'n'" fo.ntec„ to „i,.|,to,.„ ,,e,. „,i„„te '"'''°" """""^ '•""«»» fro,,, 1-ve the lu„ss, by difl„,S ;; '^r*™'°'->' ■"'"-' <, to,„l to to."l to enter the air-cell J„ .■QXl""'''^'''' "' "'« -'' -i" '..onehial tul„,, or exte,™! to the V" dy' '"•"■°" " '»"' ' "' «- P"»t„,.e l»twee,rthe afr Jtht , T'! 1 ^ ""^ **"""'"' "' '""- also by the n,eeh.,.ieal aeti", o "i, w "x'"" °' "'° ""*'• «■"' brnne of the bro,ichi (Fi, ) *' "'" °" *" """■•»'"' '"»■"■ -if s: .trrir if?,,: ^: r ;r ■■"'^''■*" ^- --"<■■- ■*«i ..■i.,«e.ei,„„,„d fo: tfi ,,:::, r*"V"r,' -^ "'■"°- essential altei-ations are that „., V , °' '"'''"al blocl. The wa""er t , venon, Jl^ I '" "'' '" °'"' ■"■ '"o ^^-e, *;-"y -i,,i,,;,,,*'„j:'«: ;----.- ■""™ «"■">•. a,,dless«arlK,,,dio,idea,,<,,,itr„ge„ 't e : ""f"''' "'"" °^^""™ = ""' expand tlie Jiat less tlian ce, tli('i('f()i«.j ' other liand, sater on t}ie I out of them '^tfd, ],y the ted fi-oni the "'^'•S ill each yomi^r and iches. The •in^'es from MANUAL OP HYCJIENK. 27 '\ in arterial blood is twice as great as that in venous Mood, Ixmuj; e(|ual to from 10 to \0\ per cent, of tlio volume of the former, and only about 5 p»!r cent, of the volume of the latter. The ([uantity of carbc.n dioxide, on the other hand, is less in arterial than in venous bh)od, amounting to about 20 vohimes per cent, in the former, and 2^) per c(int. in the latter. The cpiantity of nitrog(>n contain.'d in the blood varies from about 1.7 to .3.;] per ,-,.„t. From the fact that it is ex- haled, in small quantity, from tlie lungs, it is tliought to be present in greater proportion in v(>nous lilood. 43. The mode in which oxygen is contained in the blood may be thus d<>scribed. After it has been absorbeti into the blood from the air in the lungs, part of it mixes with the blood unci part is loosely combined with the blood cells. Jn this condition it reaches the systemic capillaries, where, co-operating in the process of nutrition and the elimination of waste niatei-ial, on.'-half of it disappears. A proportionate quantity of carbon dioxide and water is formed, which, being cairied to the lungs, is there exhaled, and a fresh supply of oxygen taken in. ide evolved 'nt, tend to 'e it exists he air will lian in the -e ill tem- liings, and -ous niem- consider- ^f venous 'od. The ) degrees e tlrmlj, B oxygen ontained ''i f CHAPTER ni. and two aeoesso^ ,,,,,„^ oaTC " r:: Sr "tL^"*™' tion of oxyeen and mim^r^r. ,•« +v, water. I he associa- ".ion. ,„f „ si.p,::r^i 'L:z:"r L? ' rr r -'-^ act m the animal economv ». . t . Nitrogen seems to oxygen. Carbon .noZZ'nTirljt" \ *'' -"""^^ation of it i^ essential, but not to tlt^rMlTr t::"'":""" "*™'' superfluous ingredient, harmless ^hentZoi.ZT'"" T""'' '^ vegetable world, on the contrary itV f °, "'" """»"'»; ^ the -;»r, „to„ „o„,«,„,,3 the eSl Lrapi*? *"*'*" """ tohfeinits broadest sense, the air ml, bT s^a to be"' " "'f oxreen, nitrogen and earbon dioxide wl ™-"P0S6d of containe, in some people, e pursuit of the ecessity of devis bilged to engfige injurious oecupa- cture of particles also allowed to iet cleaning and annoyance from Id completely do sanations in the proved in Eng- [ consumption is ; d heart disease, ' lessened by the il produce diar- when there is a dse to allow the iires of a hous«' ir contained in the surrounding soil, as well as that upon which it is built. The popular impression that the atmosphere ends where the ground beldier in barracks hat suitable pro- A.lthough a space 3 entitled to, yet space has exer- soldier, and the ■vice is much less i. Similar facts In the British 00 large, forming conditions, with may be vitiated tality from con- 1 breathe a foul Taking the last :., for 1882 and te per cent, of or 1883, 40.62; 83, 57.14. The eachers was, in ed in the report onsumption be- t the hardships n females than e to encounter ice of children, 87 than their fellow male toachors, the younger ones being invariably placed under their charge, and consequently their work is more wear- mg and exhausting. Their average ago at tlie time of death was thirty-six, while that of male teachers was fifty-two years." It has been already pointed out in the introductory chapter, that this disparity is in part clue to the, fact that many female teachers marry and cease to be professional teachers at an ea.-ly age. Still even after making due allowance for this, tlie mortality from phthisil among female teachers is excessive : the proportion of deaths from this cause to deaths from all causes amongst them being as 1 to 2.25, whilst the proportion for persons of all occupations is 1 in 7.13, and for persons of all occupations dying between the ages of 30 and 40 it iS 1 in 3.08. In 1883 the disproportion is very much greater. In this year, also, the ranks of the male teachers suffered much greater losses from phthisis than in 1882. An additional cause for the mortality amongst printers (Sec 15) may bo found in the fact that much of their work is done by gas light • the jets are not ventilated (as they might easily be), and each jet vitiates as much air as two men. Lamps are still worse. Hospital gangrene, it is believed, can be entirely avoided by treat- ment in the open air or under tents. Camp-fever may be almost entirely banished by cleanliness and fresh air. Whenever such dis- eases as Asiatic cholera, typhus fever, diphtheria, small-pox, and the like, prevail, it has been universally observed that the mortality is much increased by overcrowding and foul air, 68, The diseases of childhood acquire increased virulence from bad air and overcowding. In the four years ending in 1784, of 7 550 infants born at the ill-ventilated Dublin Lying-in Hospital, 2,944 died of epidemic disease ; after a thorough system of ventilation had been adopted, only 279 died in the same number of ytars. At the same time tuberculosis was very common in the Dublin public institutions its cause was plainly overcrowding. Bowel complaints are prevalent among children during the warm season. This is not due to the heat alone, because a dry, pure air, like that of Arabia or Arizona, is found to be compatible with perfect health. Thny occur in close cities where atmospheric moisture general filth, and an imperfect circulation of air, are associated with even a moderate amount of heat. il I CHAPTEE ly. i iiii OKNKHAT, PK.NOIPLES OP VENTILATION-RULES POK KSTIMATINQ VENTILATION. 69. As the amount of carbon dioxids k f„„„d i„ i„crc„,o practioaiiv K U, tl„. ,„,,,.,rti„„ of ,„,.bo„ ,|K,.i,,e in any given .™p|oo"e^ J nnp„n ,„ It will, therefore, be proper to consider the altnt .,.unt„,^„f f,,«,, „,„e,„i„d to dilute this to a '.ealthy standard, TO The amount of carbon dioxide exhaled is oon.puted by phyJioio C rt : " Tf T"'""''^ 0»o£ acubicLtperlS^d z. r e r t°J :":\ m"^ r r -"■ "-^ "'■■"-^ •«- Mil .o to .4 per 1,000, or 4 volumes per 10,000 propeily ventiUted a.r-space has also been proved by experimert (Parkes) to be 0.2 of carbon dio.ide per 1,000 of air, n.aking, w " L mcr'^ '", r *"" '""" --P""*^ '«>"• tl.issouto.6t 1,000, or 6 parts in 10,000 of air. 72 The quantity of pure external air required per hour by one indi .dual inhalatn,, a room vitiated by respilion, in order to keep the carbon dioxide at a ratio of 0.6 per 1,000 of air may be calculated by the following formula (Parkes) : f = ,, i, ^.i.^ . = the amount of carbon dioxide exhaled by one individual in an hour p - the i;m,> f .^"'nit^ 1r r ''''' '-'^ '- ^'"^^^^ ^^ fL per hour ^ ' " ^ ^ i ' "' "' '^^"^'"^ '' '^^^'^ ^^ ^^ ^^ic per hour. Now,^,f ^e take e at the general average of 0.6 of a cubic foot, then --^- = 3,000 cubic feet of air required. This formula may also be used conversely to find from the condition of a MANUAL OF HYGIENE. 39 >K E8TIMATIN0 croase practically n re-breathed air, sample of air can lud more danger- iider the amount piration, and the >hy standard, ated by physiolo- oot per head and las already been • 10,000. admissible in a by experimert inaking, with the is source 0.6 in our by one indi- 'der to keep the ie calculated by the amount of p = the limit of to that already resh air in cubic age of 0.6 of a equired. This condition of a |r.ven sample of air the average amount of fresh air which has been utherto supphed and utilized. For this purpose we substitute for , (the admissible l„mt). p, the observed ratio. Thus, let us suppose that ft. the observed^rat.o of vitiation wa^ 0.7 per 1.000 volumes, wo should have --= 857 cubic feet of air per head and hour, which had been suppliecl and utilized during the time of occupation. 73. The quantity of carbon dioxide exhaled by an individual is not always the same, being greater when he is occupied than when h repose t increases also in proportion to the body-weight rthe nchvulual hence the quantity . must necessarily change In nstance of adult males in repose «.0.7 of carbon dioxide, and n that of children in repose, e^OA carbon dioxide. The formula herefore, by which we have shown that 3,000 cubic feet of fr 1 ah^ are required per Wd per hour to dilute re-breathed air to a hea thy standard is one whi.h is suitable for a mixed community in a stat of thJtcltn T'T '^V'^','"'' ^^^"^ ^"^^"'^'' ^^^^ --»> '— ine excietion or carbon dioxide nnA pnllc t..,. • XI , „ '•■uAuib, ana talis tor a correspondiinr incre-iqp lu light work. . . 0.95 of a cubic foot of Co, evolved per hour II heavy i. ... 1.96 „ ' * This would argue a delivery of fresh air as follows :_ " In liglit work ,. heavy „ V-W oiibic feel. We been enlarged and ventilated. In civil 1 fe Httle aH r naid t/i tVii'a o„k;„ a i , . ^ little attention as pa.d to this subject, a^d yet xt is a fact of some interest to us that 40 MANUAL OF HYGIENE. cattlo and other uniinals properly f,.d will thrive better in a well- ventilated place at a low tenipi^rature, than in a warm place ill-ven- tUated. There seems no reason why the same rule should not apply to animals as to men, in which case something like 20 to 25 cubic feet per hour per lb. of body-weight ought to be supplied. 77. The quantity required for lights will depend on the kind of light used. If no provision is made for the sr: oial ventilation of «t i» view, those who are fn tl Jror VJ , 1 . TT '^''^ '^^^^^^^"^ ^^ ^^ buted through a conside" ble n ^b r /^^^^^^ roon. at the floor line and 1 in" bv t. f T- '""'' *^ ^"**^'- *'- the ceiling. This plan m^yZZ L^U T ""^' ''"' "^^^^ ^^ of heat; but it is used in In i) r "' ''^ «o»«i''e'-ed wasteful acoo,*,,, to the season, into iT':^^l!Z;2r'''^°' °' "°°'-' May descMd by tils walls and „, ■ f , " '"""• 'o """ ■» from the room at the flo^ Thn"'°" ' *" "'""'''''^ "-■ ^-"I- i" cold weather the a," bL,™ ? d, " °''? '" "'= °''J««™ '4 -..tact with the walK ^71 2mV."' "' ""'"« ''-<>"«'" "> ' """' " '"«'■*• ""!<»» "Peoial veutilatio,! is MANUAL OF HYGIENE. 48 tnd they have -iive cents per io arranged as cubic feet of ioors may be >rmy weatJier, tilation. Dr. ilet, and the pted to meet 5 a room of 3cond at the felt from a icribed here- d the initial ' cubic feet, >re reachinjr 2ial ventila- lividuaJ, the ii" per hour ptible even le inlets. d question. ct in view, ing line of erly distri- 3 enter the escape at i wasteful excellent. provided for the gas fixtures, the products of gas combustion are breathed by the inmates of the room. 84. In summer our endeavor generally is to secure the largest amount of cool air. There is also a necessity for a larger amount of ail, as the amount of organic matter thrown off from the skin in the form of perspiration is much greater in summer than in winter, and calls for freer ventilation. On the other hand, however, the outer air is nearer the temperature of the body, and can be more freely admitted. Where rooms are fully occupied in w irm weather, ventilation by the windows will not give a sufficiency of pure air to all the inmates. Pure cool air, admitted at the line of the floor, well distributed through numerous appropriately placed openings, and allowed to escape at the ceiling, seems to answer all the necessary indications. 85. In cold weather, on tlie contrary, our efforts are directed to securing warm air. We warn, the air, but we do not usually provide for a sufficient access of pure air. One reason for this is, that we wish to economize fuel, experience having proved that a constant access of pure warmed air to our bodies requires the consumption of a largo quantity of fuel. A second reason is, that we rarely provide sufficient outlet for the impure air, and, consequently, cannot expect the entrance of the pure air. Supposing, however, that we wish to have efficient ventilation in cold weather, the warmed air may be intro- duced at the floor in finely divided currents, well distributed, and allowed to escape at the ceiling; and this system of ventilation is quite as suitable in cold weather as in summer, owing to the opera- tion of the law by which heated air constantly tends to rise. One remarkable advantage possessed by this plan is that the outlets do not require to be specially warmed, the impure heated air escaping from the uppermost outlet in the ceiling with great ease. To .secure the best results from this plan, it is obvious that the incoming air must be so distributed at the floor line as to reach in its upward course the whole area of the room. As carried out in practice it is often imperfect, the warm pure air being impelled into a corner of the room with great force, and allowed to escape at the ceiling with reckless facility. When profior attention is paid to tl,R distribution and breaking up of the incoming current of pure air, it works admirably. 44 MANUAL OP HYGIENE. at^n? *!r °*^-r "^""l ^ "'^^P*^^' *■"•' *^« introduction of pure air it should. The action of f h A . * ^''^ occupants of the room aa Fig. 7, Sr3.=iS"~==-'=™X™.r.a and up the chimney, as shown in Fig. 7. T'.is IctLn of th! w '"""'' '* the breathing point of a person sitting." • °^""^ '"'^''**" MANUAL OF HTGIENK 45 "It may be well to explain that in these experiments the outlets have been *t least twice aa large as the inlets, and that there has always been heat in the outgoing flues to produce a strong up current, as I believe this to be the only jure way to produce a constant outflow of air." Fig. 8. " In Fig. 8, the outgoing flue is in the same position, but the incoming flue has been raised about two-thirds of the way towards the ceiling." HI ; ■. j ! "In Fig. 9, the fliipa have been placed on about the same level, but with no better resDlte.'' .fflfr" 46 MANUAL OP HYGIENE. .^ ^1 Fig. 10. .fl5fATt*J!iP LINE ^^ Fig. 11. v»f K t ' ^°*u "'^ ** ^^^ ''°°'' '^^"'' ^^'t*^ *'«"e'' results than have yet been obtained, but st.ll far from satisfactory. I have thus tried to show the general action of incoming and outgoing currents of air by the placing of the introduction flue.s on the outer walla.'- *^ * * * * « "Id the Bridgeport School the coil-boxes for the heating of the var*io„s binlding and the air conveyed from them through these shafts to the room.s bv mean, of nietal tuDes. ihe air enters the inner corner of the room about eight 1 1 MANUAL OF HYGIENE. with the results 47 feet from the floor, the corner being clipped so as to form a flat service for the register opening; underneath the register the space is utilized for a closet for the use of the teacher. The outgoing flue has been placed directly under the platform, which is located in the same corner as the introduction Hue. This platform measures 6' x 12', and is supplied with casters, so that it can be moved at any time it is necessary to clean under it. Its entire lower edge is kept about 4" from the floor, to give a full circulation under it at all points. The action of the incoming air is rapidly upward and outward, stratifying as it goes towards the cooler outer walls, thence flowing down their surfaces to the floor and back across the floor to the outgoing register. By this method all the air \ \ ■%- K /i .^: ffftf-^ ^1/1 % ^K i-) ?i>^ ^t ^'' ) ;■ ^ ^- Y .rv^ ^*^ ^-±j, . "^ ,^ J Fig. 12. entering is made to traverse with a circular motion (see Fig. 12) the entire room, before it reaches the exhaust shaft, and there is a constant movement and mixing of the air in all parts of the room. All the heat entering is utilized and I believe that if the supply and exhaust flues are properly balanced as to size, there can be a very small loss of heat." "The inlets are all intended to be large, and the flow of air through them moderate and steady. The air is not intended to be heated to a very high temperature; the large quantity introduced is expected to keep the thermo- meter at about 68° at the breathing level." If the system indicated in Fig. 12 is adopted, great attention will have to be paid to the proper heating of the flues, with wliich the outlet tubes are connected, and the outlets will require to be much larger than usual, and air-tight. Besides, the outlets would have to bo all of equal length, othurwi.so the shorter tubes would draw better than the laager ones. Whichever plan is adopted, its value will have 4 jiii \ 1': ' ' . M IT" 48 MANUAL OF HYGIENE. ill to be measured Iry the ease, completeness, and cheapness with which It accomplishes the object in view. JJ:J^'^''^ ^''" '""*' ''""^^^ ''"^P^ "P"^'-^«' to prevent tho entrance of ran. or snow. They „,ay eonnnunicate with the externa air by means of perforated bricks or gratings, so as to div,^ leX entenng current and break its force, or they n.ay be provided with des, ed extent. It may be necessary to cover the orifices of these miets with mushn or papor-hanger's canvas, in order to prev n tth entrance of dust. They should be so constructed as to prevel „„ pleasant draughts. ^ " 88. Windows can be opened in mild weather for at least part of the day and xf raised at the bottom one inch and lowered at the top a, tig. 13.— Tlie lower sash is raised a few inches, and the space beneath is Hlled by a board; an upward inlet is thus made between the saslies. WALt. BOARD Fig. 14.— Sectional view of Fig. 13. ^J^- ^^A~\ ^"^ (^^) slanting downward and outward is affixed to the top of the window frame, and the upper sash lowered ; a second openin- Is thug secured. f °"'"= 89. The method suggested by Dr. Cotting of raising the lower sash a few inches and inserting beneath it a board the width of the win- dow secures a considerable ventilating space between the two sashe^ at their point of junction. (Figs. 13 and 14.) MANUAL OF HYGIENE. 49 )ness with wliich A similar plan is that sJiowii in Fig. 15. The opening at the top will act eitlici- as an additional inlet, oi- as an outlet, according to circumstances. It is protected by the slanting board (AA) in such a way that, if it act as an inlet, the air wUl not blow directly down- ward. The adaptation of boards at the top and bottom of the window, by which a current of air in and out of the window is created, is also an excellent idea, which may be applied in practice at very little expense. Where the heating of a house is txlective, this plan may be kept in operation during very cold weather. 90. All outlets, whether specially warmed or not, should be lined with some smooth substance, such as tin, or should be made of tile- pipe, so as to ofter the least possible resistance to the outflowing air. They should be straight, circular in form, and surmounted by a cap, so placed as to prevent rain from entering, but not to interfere with the up-draught. They should not be built in outside walls, Avhich are exposed to the weathei- nor should they be lined with rough plaster, as they too frequently are. They should be carried up independently of each other through the roof into the open air; occasionally they may be made to converge in the attic to a large common outlet. They should be protected so as not to lose heat. They should be warm, at least as warm or warmer than the outer air, or else the current will be inverted. In dwelling-houses the heated chimney flue, with an open iire, is an excellent outlet, so good that in cold weather an open lire or two may with advantage be kept burning in inhabited houses, no matter what the system of heating may be. When rooms are large and more crowded, a greater number of outlets is necessary, and the heat of the fire may be further utilized by surrounding the smoke flue with outlets. In rooms where the construction of such flues has been neglected, neatly painted 4 in. pipes may be substituted. The lower end of the pipe should be funnel-shaped, and rest on feet 3 or 4 in. from the floor, in some convenient position. Its upper portion should turn by a cur\ed elbow, and connect horizontally with the stove-pipe. The cold air is thus drawn from the floor. 91. Gas, if used, may be also employed to warm an outlet tube, with the double object uf carrying ofi' tJie pnjducts of combustion and of utilizing its heat. The best arrangement appears to be to place • ■ ! I , i i SI I I f V 50 MANUAL OF HYGIENE. ill 1 1 tion, and to case the pipe itself with another ti.h. d.. , .Mch is at the ceiling; the tube carrying off t, '^' p ^ J^Thol enough to cause a very considerable draught in its caJn! , .1 two outlet currents are in operation, one ov r h "15' the ceiling around the gas tube. ^ "'' ^''^ ^''''^ 92. Outlets should be kept clean, for in snite of nii r... .• discussmg the vanous methods of ^varming buildings. 93. The terms natural and artificial are applied to systems of venti lation according as the forces which move the air «! . T artificial. Though convenient, this division^:ttTtn^, ^^t a^^ 94. In natural ventilation the forces which act are: (1) diffusion ^9^ 95. Diffusion aids in the purification of gaseous substances- but organxc xmpunt.es which are molecular are .0. affected byT^Thi law of dxffusxon, which is in silent operation at all time^ operate powerfully .n preserving the equilibrium of the atmosphere ' 9b. The wind is a powerful ventilating agent • but it i. nn..^ • m Its action and in cold weather it cannot be endul^ XuT'^ penng. When the wind passes through a room with opeTdooL aTd w ndows we have most effective ventilation. Even when doors !nd windows are closed the wind will pass through wallsif wo^d • f 97. The velocity of the wind in this conntrv p^e-nt in v wpather, is verv "reat Th« o, ■-'"^■' ^'f^^-pt m vury warm , IS very great. Ihe average mean annual velocity of the MANUAL OP HYGIENE. 61 wind at Toronto for the year 1879 was 10.36 miles an hour ; for 1880, 10.54; for 1881, 9.91 ; for 1882, 10.42; and for 1883, 10.08. The month of greatest mean velocity from an average of 34 yeai-s is March. The month of least mean velocity fr^ ui the same average is July. The greatest daily mean velocity for 1883 was 27.29 (on November 12), and the least daily mean velocity for the same year was 2.50 (on August 8). The anemometer used in making these cal- culations of the movements of the air is situated at a height of 76 feet from the ground. Formerly, when the anemometer was placed at a lower level, the average mean annual velocity of the wind at Toronto was quoted at 8.32 miles an hour in 1878, and 8.33 in 1877. The prevailing direction of the wind at Toronto is in summer west and east of south, in winter west and north-west. 98. The perflating power of the wind in this country is considerable, and it may be relied upon as an efficient means of ventilation. It is difficult, however, to regulate this force in cold weather, unless the incoming current of air is warmed before it is distributed. In sum- mer perflation is our most efficient means of ventilation. 99. The aspirating power of the wind materially assists ventilation, because a moving body of air sets in motion all air in its vicinity, the surrounding air flowing towards it in a rectangular direction. In this way the wind blowing over the tops of chimneys causes a current at right angles to itself up the chimney, and the unequal draught in furnaces is owing in part to the variation in the velocity of the wind. Advantage can be taken of this aspirating power of the wind to cause a current of air in an outlet. 100. Cowls placed over tubes tend to improve the draught. Thus a iixed cowl, consisting merely of a cone as a t'ig. lb. Up-draught pipe. 1 ig. 17 Down-draught pipe, ^ap, and a similar flange around the A rim of the pipe, insures a fairly constant up-draught (Fig. 16) reversed arrangement insures a constant down-dr.aught (Fig. 17). Movable cowls are also constructed having vanes attached to them, : 1 III °2 MANUAL OP HYGFENE. Jhich turn the ,„outh« of the cowls to or fro,n the wimi, according as a perflating or aspirating force is required, u.s shown in Figs. 18 1" 19 respectively. ° Fl(f. 18.— Revolvinp cowl, with down- arauglit or perflating action. Fig. 19. -Revolving cowl, with up- draught or aspiratinu action. 101. The pressure of the wind sometimes prevents the exit of air from a particular opening hy blowing down a chimney or a tube Makers of cowls have taken great pains to overcome this difficulty by «.ving different shapes to the cowls, but the shapes depicted n'the diagrams are sufficient for every purpose. The pressure of the wind when blowing at the rate of 10 miles an hour IS equal to | lb. to the square foot; in case an out" were Tprsibir '''' ' ^^^'' ^^"""^- ''-^^' '^ -^^ '- e^early bv wLl!f 1 ''"*"?*' °" °I ""■"' " ""'^ ^"""*'^*^^ ^^ *h« "«« «f cowls, by which the wind may be ma.le to penetrate into the hold of a ...^e or between the decks. •* v^.. t>i 103. The difference of weight between masses of air of unequal te^nperature is the cause of the wind itself; but in discussing veiZ- ton It IS mentioned as an independent cause. When air is heated by any cause, v. a fire, or the resniration of men or ani„,als, or when il becomes moister, it endeavors to expand, and if it can escape a portion bulk of the colder air outside. The outer air will then rush into the room until the equality of weight inside and outside is re-establl,ied But as the co d air which enters is in its turn heated, the movemeut |s kept up as long as the source of heat continues in operatir tI IS the most useful agency m natural ventilation in cold weather. CHAPTEB V. -1 1 ' i APPLICATION OF THE FOHEGOING PRINCIPLES — WARMING. 104. In the practical application of natural ventilation nothing special is requisite to allow diflusiou to act, except that there shall be coni- inunication between two atmospheres. This foroo acts to a very slight extent in the removal from a room of the impurities which result from respiration and coniliustion. 105. To obtain the perflation of the wind openings capable of being closed when necessary should be placed on opposite sides of a room. When double windows are used spaces may be left at the bottom of the outside sash and at the top of the inner one; double panes are sometimes used in the same way, so that the wind is obliged to pass up between the two windows or the two panes, as the case may be, before it enters the room. 106. Glass louvres, which can be more or less closed, are placed in one of the panes of the window where single windows are used, or a number of holes may be bored vertically in the lower part of the upper sash. The upper sash of a window should always be made to open, as well as the lower one. 107. Ellison's conical bricks, which are pierced with conical holes about f„ of an inch in diameter externally, and 1| inch intei-nally, depth 4| inches, are of service in permitting perflation. The wind blowing on them is so distributed as to be imperceptible as a draught in the room. 108. The Sheringham valve (Fig. 20) is an improvement on this ; the air passes through a perforated brick or iron plnh', and is then directed upward by a valve opening, which can be closed, if neces- sary, by a balanced weight. A modification of this, called " the Eureka ventilator," is much used in Boston. These valves may be placed in the house wall rsppositc a heater, where direct radiation is used, to warm the incoming air before it is Fig. 20.— Sheringham valve. distributed. M i I ii| 54 Manual of iivofE\K. 109. Tobin's tubes have Leon iimc-li nr.i.\,vl f w fresh-air tubes oarrie,! hiuhor Zl^ \ f" ^"''""- ^^'^ ""'^ roo.ns with win o v o'T n "T"' '""' ^"-'-'-"ght3- In method of i.;:t:: r .rZi^' '''- ' '"' " ^° ^ -— ^«- 110. The jacketted stove, with its methori nf ..« • • air. war,„ing it and distributin.. it t „ " . , ''""'"" P'""^ ^^''^ tive. economical and convenient metio I ^ 'r""' '' '" ""•'^' '^"■"^- into houses which have "en , ilt H /'"' '^ ""'''^' ^"''•^'^'"^ requirements of vontil.tion '^ , i ^''"^''' '^"''"*'°" *« *'"« speak of "Warming " "'^ '^ '"'^"''^^ ^^-^ -e come to ha!!l^ a2J':ikr::l r ""'" ^ ^^"^^-^^^ ^^^ --^^'^^p^ v oiled ;aper, perfor" d wi " "'"^' '^ *" '''^ '"-'^ «^ -- or thus there would be almL on T "^ T" ''^ *'" '"'' ^'^ -" ^''^^^i with the extemU drto ,7 "'' '"'*'""^' "^ *'^« -"""unicaciou 112 RnHcT ?^ ' '°"'*^"*^ ^^^ ••^* ^" P'-^'-ts of the room 112. Potts has mventod a system of ventilation well suited wT len^h into wrcit:^^:!.^;^:^^!^^": t r^ perforations t1 J: :Cr' "^*'-"" "°" *^"'^"^^ ^ -« flue or other air ITan e^^^^^^^^^^^^^ '^^ --ke of small openings, similar to thor:ft ^ ^^^^^^^^^^^ ^1 air, being colder descenrk W if. cnanneJ. As the fresh being wa:„,„, riis ^ '^t^^, "^f 7'^> .""=• *^ vitiated a,>, principles of the .j,te™ ar trLr Mr hV' "" 'T" """ *= London (Eng.) School BonJ J ,' °"' ""''ileot to tho ventilation, for sightliCXonlro h Jl? tr^^^^ '"' perties (Wilson). ' ^^ self-acting pro- t^e .te.^ a., pa.t-aiot/r::i:- 't:r:r^^^^^^^^^ ?-?«^' MANUAL OP HYGIENE. 56 ■\ while on the fourth side anotlior perforated tube is connected with tli(! chimney wliich nets as the extraction shaft. 114. McKinnell's circular tubes consist of two hollow tubes, one within the other, and of such relative calibre that the transverse' area between the tubes is equal to the sectional area of the inner tube The inner tube is of slightly higher elevation than the outer, may be sur- mounted by an up-d.uuKht cowl, and m-.i .. •. ^he outlet. The fresh air enters between the tub..s, and i.s thro- i^ alci,, ;he ceiling by means of a horizontal flange surrounding the ow,.r mai, n of the inner tube Both tubes should be situated in the .^rJ.ro of f e ceiling or roof. If there is a fire in the room both tubes m^ U.-ome inlets. To prevent this the outlet tube should be closed ; if doors and windows are open both tubes become outlets. The movement of air by this plan is almost imperceptible. It suits round or square rooms or small churches; to very long rooms it is less adapted. The tube is made of all sizes from 6 inches in diameter, which is suitable for- a sitting-room, up to seven or eight feet, which is the size used in some churohes. The tube is also well adapted for guard rooms, cells and rooms of small dimensions, when it is desirable to have the ventilating apparatus out of reach. 115. Watson's tube, a simple tube with ■Wiitson's tube, with par- * partition down the centre is here illus- — -- ■• ^^^^g^_ (Fig. 21.) In this tube accidental circumstances, such as the sun's rays on one side, the wind, the fire in the room, etc., will determine which is outlet and which is inlet 116. Artificial ventilation is efiect^d in two ways; either the air is extracted from a room or building (extraction), or it is driven in so as to expel the air already in the room (propulsion). Extraction may be accomplished by various means, viz., by the application of heat so as to cause an upward current, or by a steam-jet, by pumps, fans, archimedean screws or wheels, which draw out the air. 117. Extraction by heat is well exemplified in the common chimney with a fire-place. When the fire is burning there is a constant cur- rent of aar up the chimney. The movement will be great or smaU in Fig. 21 ..„, „.„„ titlon for inlet and outlet iii II tj 56 Manual op hygiene. proportion to the size of the fire and the clunmey. A kitchen or furnace fire causes a very free movement. If the area of the flue i known the discharge of air from it, as measured hy the anen omete may be stated in cubic feet. Grates, fire-place." and open tove' of various patterns are simple plans for accomplishing extractiZ Whei-e these are used U> heat rooms, the smoke flues should be ur" rounded by ventilating shafts having direct communication w th the rooms. If a heated shaft is used to ventilate a building, steam pipe passing to upper stories may serve the same purpose a suitablv arranged fire, or one or more gas-lights in the upp'er pa";f the ^ wm also furni,sh ascensional power. The gaf-Hght' may ^ifti additional purpose of lighting an upper hall or room. In Iheltres the thiough the roof being built over the principal chandeliers Objections to this method of ventilation are frequently found to re pose on the fact that an injudicious "economy" has'interLed with the necessary consumption of fuel, and th..t the extraction being weak the escape o foul air ha.s been necessarily impeded. When flues or shaft are regularly warmed, insuring dryness, there is rarely any d^tZ in securmg a good upward draught and satisfactory extraction. ^ 118. In extraction by the steam-jet the moving a^ent is the fnr.« the steam jet, which is allowed to pass intt ^ chimney Th plan IS suitable for factories with spare steam. 119. The archlmedean screw ventilator has been recommend.^ f ™a,l air-shaft. and „. also been applW to .arge C^" may be worked by steam power. shJ" At'tl? Ab' ''" ""' " T"'^ '' '^"" «"* *'- -'• through a sliatt. At the Abercairn mine the fan has been mide fn . f / much as 45,000 cubic feet of air per minute "''""' '^ 121 The exhaust wheel may also be used to accomplish similar results. It may be used with advantage where for any special reason xt IS necessary to have frequent renewal of the air. WhL a w" m operation m a . om or building, the air is rapidly affected by he variation in pressure, and a movement is produced in every part Such a wheel may be placed in a wall or window without the 2d of « shaf Ventilation may thu. be made to work satisfactorily without creating strong draughts, the impure heated air being made tol^c td MANUAL OP HYGIENE. 57 while the admission of pure cool or warm air is regulated by recisters in the floor. * 122. Propulsion as a system of ventilation was introduced in 1734 by Dr. Desaguliers. It may be carried on by means of a fan, enclosed ma box, which can be worked by hand, horse, water or steam power The air enters through an opening in the centre of the box, ., ,d is thrown by the revolving fan into a conduit, which communicates with the difierent parts of the building. In France and the United States the fan is employed in the ventilation of many large buildings, the air being forced into a basement chamber, where it is heated or cooled according to the season of the year. In the Asylum for the Insane at Kingston, Ontario, fresh air is propelled into the building. In winter It IS made to pass over sfeeam coils before it is distributed. In some cases two fans are employed, one for propulsion and one for extrac- tion. This plan is used in the New York Hospital, the Madison Square Theatre in New York City, and the Trocadero in Paris, Prance. Propulsion and extraction are thus used in ventilating the House of Commons at Ottawa, the extraction being accomplished by a heated flue at the ceiling, and by an exhaust fan, which draws away the air rrom the floor. 123. The Madison Square Theatre is one of the best ventilated build- ings of Its class. The air is taken in at a tower above the roof, and is sifted through a conical bag of cheese-cloth forty feet long, suspended in the tower; ,t is healed by steam in winter, and cooled by passin. over ice in summer, four tons being required for each evening On^ fan at the foot of the tower forces the air in; another on the roof exhausts i . The doors and windows are kept closed; heating, cooling and distribution take place in the cellar. The air is introduced by pipes running under the risers; an opening in the riser at eao.' seat discharges a forward current with a velocity of two and a-half feet per second. Other jets enter at the front of the footlights and below the balconies. The outlets are chiefly under the balconies, so that there IS a general movement away from the stage. It is thought that the acoustic eff-ect is improved by this circumstance. The footlights are ventilated into a horizontal duct in which the g^ pipe is laid, tJius heating the gas before it is burned. The great dome light and the other gaslights are enclosed in glass and ventilated upwards. The IN V 58 MANUAL OF HYGIENE. -apply IS MOO feet pe. head and hour ; the theatre seats 650 persons ^nd ha. a capacity of 00,000 cubic feet.-(Lincoln). We have been hus particular in giving the details of the ventilation of thlsbu Id stances provision should be .ade for naluMwentilaU ^ 1 1~: a chinates .n most eases, especially for dwelling-houses and hosZ na ural ventilation, with such powers of extraction as can be got t chtfTblct' "T" '' ^"™^"^" '''' ''^^''^^' '' *^« ^-*- One'of the chief objections to aspiration by heat, considered as a sole reliance is great but temporary increase of ventilating power. In cases where ^che..ergeiicies are likely to arise, mechaiL' propulsL o llitd with mechanical aspiration deserves the preference This comb ned quality of an- is accompanied by fewer inconveniences, is easier to cTrci:^-- ''''-' ' ''-'- ''- ^^'- «^-- ^^ ^^^-- 125 Artificial warming of houses is necessary for about seven months of the year in this country. All person's, however do not require the same amount of artificial heat. Healthy, well-iad and we 1-fed young people and adults endure exposure totld very well and find it invigorating; the temperature of a house may, therefore or them be regulated by what is comfortable. Young c'hildl Id old people generally require a temperature of from 65" to 70" rlhr 126 Sick persons are more likely to suffer from hot, impure air than from cold air. T., febrile diseases, such as pneumon a, 'xposure to pure cold air is beneficial, so Ion, .. there is no direct draught on the person. The same remark holds good of consumption, in the reatment of which pure air is the principal requisite. Persons suffer! Z^r Tr \ ^''''^'^ '' ''" ^^^ P'-^^^^S-' ^-- chronic heart disease, and those who are convalescing from acute diseases, require a warm air. ' ^1"^^° «* T. ^"* •.*!?.* '! '""""""'^^^ted by radiation, convection ...nd conduction. It IS with tixe two modes first named that we are principally interested. MANUAL OF HYGIENE. 69 An open fire in a grate or fireplace is a good example of artificial radiant heat, as most of its heat is given off by radiation to the walls of the room, and to objects and persons in the room ; very little by convection. This method of heating, therefore, does not add any impurity to the air, while it aids the ventilation of the room by providing an eflicient outlet. The objections to its use in this country are its expensiveness and the fact that, at any considerable distance from the fire, its heating power is feeble, and that it does not heat surfaces which are not directed towards it equally with those which are so directed. 128. Stoves also radiate heat, but they principally heat the air by contact, the heated air being carried to different parts of the room by convection. As long as the a-"- is not heated above 75° or 80° no harm is done, and the heated air is pleasant ; but as soon as the air is overheated it acquires a peculiar smell, and is said to be burned. Such air is relatively dry, and absorbs water largely. 129. A hot-air furnace, with its fire-box, is analogous (so far as con- vection is concerned) to the case of a stove standing in a room. The furnace radiates heat to the walls ! the box, which are usually of masonry, and the air becomes warmed by contact with the surfaces both of the furnace and of the box. If the furnace is not too hot, and the air is freely changed, the effect is pleasant. It is better, therefore, to have a larger stove or furnace tlian is actually needed, and to keep a moderate fire. This is true whether the room is heated directly or by registers. 130. Over-hsating of the metal is of frequent occurrence with very many of the stoves in common use in this country. This over-heating of the iron, and the consequent spoiling of the air, may be prevented in two ways, viz., .by placing an inner lining of fire-clay in the fire-box of the stove ; or by constructing the stove with an outer casing of iron, with secure joints, so placed as to leave a stratum of aii- between the firebox and itself. " Base-burner " stoves are thus protected. Some of them, however, are so badly constructed as to be very injurious from the escape of carbon monoxide and other injurious gases, pro- ducing the effects described in Chapter III. (see sec. 54. etc.) 131. Over-heating of air in furnaces may be prevented by providing Uberal channela for the passage of air through the hot-air box and i ij 4 11 60 MANUAL OF HYGIENE. correspondingly largo apertures for its escape from the rooms Thus ^j^:::^' '-' '-- ''-^'' -^ ^° - ^- ^^^ : 132 The quality of air supplied is much influenced by the construe, t o„ of stoves or turn.u.es and their n.anagement. Thul, the pr'kcts of con.bust.on .. ay escape from a stove or fu.-nace of a^y descHpt" o whe.. he dan.per in the smoke flue is too close. A da npIsH neve.-^be placed in the smoke passage of an appa.atus in ut t t::tL:t ^'r *': ^^^ -^*-« the Ar, no't where it Wi Cas -»o, furnaces, when they become .-ed-hot, allow the prodacts of con.bustion to escape into the room. A suitable material for m^i,' stoves or furnaces which shall be free fron. this defect exSts in wought-iron, which can be made perfectly tight by overlapn „ " • nve .^and h^me^ing the edg.. Soap-stL ^rnacL Z^Zl tyhi also The hot-ai. box and the cold-air duct should be made |.ht so as to exclude cellar air. The supply of air for the L a'^ that for the au-box ought to be entirely separated from each other 133. The proportion of inlets and outlets in a hot-air furnace is . matter requxrxng ca.eful consideration. "The inlet i ■ cold ai i," Its s...allest part ought to have a transverse sectional ar. ■ .f one- ix of a square foot for every pound of coal (anthracite) bu, ..t per hour ve.y cold weather; and the latter may be estimated at'.^, of th probable monthly consumption for average weather."- (Dixon ^ Fo bumt\' nT '"".""^ "^ ^" ""'''''' *^^« *«- ^ --th will bu.n n the coldest weacher ^^.> = nearly 15 pounds per hour which 134. A current occasionally flows downward in one or another of a Mency the phe.aome..on is analogous to one chinmey suckh.. another where both co..nect with one room. It arises f,.o.n a con siderable d.sp.-opo.-tion betwee.i "the ascensional forces" in ^i > . .es A short duct ente.-ing a cold room might easily d.-aw >] , ■ ■ air down mto the furnace box, instead of sending wann ah ^ui\ke re.„edy is furnished in part by so p.-oportioni..g the size o Jhe col ective exits to the size of the inlets, that cold air e..te,-ing at the latter expands m proportion to the greater capacity presented by the MANUAL OF HYGIENE. 61 outlets and not more. "The collective area of the hot-air pipes should not be more than 1 greater than the least area of the cold air inlets, assuming that the heated fresh air is to enter the rooms at the temperature of about 120", when at zero outside, and its velocity in the hot-air pipes not exceed five feet per second."— (Buck.) When a cold-air duct opens on the lee side of a house it has a ten- dency to convey its air in the wrong direction, or the indraught is lessened. When it opens on the windward side it requires a slide to regulate the amount of air entering it. In some large buildings with many flues, the orifice is so exposed that the difference between the two sides is very troublesome. This may be remedied, as nroi)osed by Mr. Tudor, by providing a receptacle of air of large size and con- venient position into which ducts open from various sides in ti^c walls ; the supply is thus made constant. 135. The ventilating power of different stoves varies. The air re- quired for the combustion of fuel is very small, and in the "air-ti./.air: the temperature should not be maintained by 0^^^^^^^ i. If ^^^ '^°'!*"'*' '"''"' """""^ ^^ P'"««e"* ^" ^ h«^% atmosphere IS often deficient m the air of a room heated artificially • every ZS apparatus ought to be supplied with an arrangement tevTpoS water. Experience shows that the result is both agreeable and n2 ficia ; but in our anxiety to accomplish this desirabi: end we lu d bt careful not to run to the opposite extreme. A rou^h but .ffi . jnethod of determining whether we have reachtd t" :f o::^' ho r'f t? "' ?' "1'"" " *'^^ °' "^*^^-«" *^« window^anell th se of the outer windows, if there are double windows. The cold outside air will g,ve us the «' dew-point" sufficiently long befor^he air of the room has reached the point of saturation. CHAPTEE VI. EXAMINATIOH OF AIB AND OF THE SUFFICIENCY OF VENTILATION. 142. If an examination of the sufficiency of ventilation should be re- quired in any particular case, the following method may be adopted:— (1) Determine the amount of cubic space assigned to each person, the relative size and position of inlets and outlets, the distribution of the air, and the number of cubic feet of fresh air which each indi- vidual receives per hour. (2) Examine the contained air by the senses. (3) Examine the contained air chemically. (4) Microscopically, for suspended impurities. (5) As regards temperature, moisture, etc, 143. To obtain the cubic measurement of a room the three dimen- sions of length, breadth and height are multiplied together. Where rooms are regular in form this is a simple process; but where they abound m angles, projections, half-circles, etc., the rules for the measurement of the areas of circles, segmente, triangles, etc., nmst be adopted. After the room has been nieasured, recesses containing air should be measured and added to the amount of cubic space; and, on the other hand, solid masses, such as furniture, etc., which take the place of air, must be deducted from the cubic space already measured The allowance for each bedstead and bedding may be estimated at ten cubic feet, and the space occupied by the body of each person at three cubic feet. In linear measurement it is convenient to measure in feet and decimals of a foot, instead of in feet and inches. 144. The relative size and position of inlets and outlets, such as doors and windows, and how they assist in the ventilation of the room should be noted If there be a fire-place in the room, its sec- tional area at the tr.-, .t should be ascertained. If the system of ventilation is artificiil, the doors and windows should be closed, and the movement of the air should be examined through the other openings. The direction of the movement may be ascertained by '"^mmf' Mill 66 MiSSTA^, Ap iiVOIENB. Ob emng the smoke f.occeding from burning feathers or cotton velvet. The directu,. being known, it will suffice to n^easure the discharge through the outlets, as a corresponding quantity of fresh air must enter through the inlets. ^ 145. The anemometer, or air-meter, i« a u.su uu.ent usrd iri cleter- mmmg the rate of the movement of air through an opening. It „.ay be described as a mmiature wind-mill. The little sails driven by the air-current seo in motion a series of small cogged whe.ls, which move rZd «'r °" ' ^^"P'"*" ^^^ "^^°"'^ «^ *^« ^--^-^ «-« thus L wht f. k' ^"'" ''"'' ^" *^" "^™« "^^ - *he amount of gas wh, -h ha. been consumed is appertained from a gas-meter. An instrur.ent of this character has been constructed by Mr. Casella, of Hatt.n Ga.den, London (Eng.), with indices on the dial-plate indit- ing the velocity of an air-current in feet, hundreds of feet, thousands, e C, up to millions. By moving a catch tb machine may be stopped at any moment. *^ -•'"ppeu 146. The method of using the anemometer may thus be described Before using the instrument the relative positions of as many of the mdices a. may be deemed necessary are noted. When the instrument 18 placed in the au-current, time is called, and the catch is moved to Bet the machinery free. At the end of a pre-determined ,, .iod, time s again called, and the machinery immediately stopped l!y melns of the catch Ihe amount, which was noted b- tore the instrument was use. IS then subtracted f • .n the auount v ,eh appea.s on the dlT plate, the necessary corre.. on* tor the instrument made, and the product will be the linear dimension of the current for the Le fixed upon If this amount is mu'(ip^:.3d by the sectional area .' the open, mg, the volume of air which has passed through in the same time can be calculated in cubic feet. When the anemometer is used in a tube ., shaft. It should be placed well in, but not quite in the cen- hec .e the velocity F the current m the centre is greater than at sici of the tube. Should the shaft be large, the rat^ of movement ught to be taken at different * iii'iumentsare generally accompanied bv a alio sUUmr ih^ «.,.^.v . . ~[ to be «lded to, or subtracted from, the reading on he dTa^ ^ mZZ^"\ °i- "f ^■'''°" "*= measurement. These corrections have h.., Je^^S hv ^o^ „?■ - - '^^.'"'''''''''f '""^ '"'^' MANUAL OP HYOIENB. parts, and the average ascertained. So, also, when the rate of move- ment is irregular, several observations should be made, and the average of the whole of them will give the approximate velocity of the current. " If placed in a tube very little larger than the instrument, the result cannot be depended on, and when placed at the entrance of a tube — for example, against a perforated air-brick or grating — the N'olocity of the current indicated by the anemometer is considerably less than what exists in the tube. In these cases the instrument should be exactly htted into an opening in a box large enough to cover complet ;ly the mouth of the tub \>y which means the whole oi the air passing through the tube may be made to pass through the openii g in the box."— (Wilson.) As we have already stated, after having ascertained the direction of an air-current in a room, it suffices to obtain the cubic discharge at the outlet. If there should be no other air outlet from a room except througi th chimney, the anemometer cannot be used when fires are burning in ! -torn, as it would be injured by the heat and dust. l4. The manometer is an i^istrument which has been constructed to meet ; -ch an emergency. It is intended to measure the pressure, and, b calculation, the velocity of the air. The current of air is allowofi to imp- e on a surface of water, and the height to which the water is thro^\ > a tube of known inclination and size gives at once a measure of force. Tliis instrument, necessitating a little calculation, is less useful than the anemometer. In practice it might be connected by a long tube with a distant room, and, thus constructed, would be well fitted to measure constantly the velocity in an extraction shaft 148. Examination of the contained air by the senses gives to. .ably reliable results ; but it must be made immediately after coming irom the open air. The following selections from the report of Dr. de Chaumont's experiments show how closely the sensations accord with the difierent degrees of impurity, indicated by the percentage of carbon dioxide. At . 14 in 10,000 parts Extremely close and unpleasant* n .10 II It Extremely close. •I .09 II I Close. I" .08 >i II Not very foul. II .06 II Not very olose. M .05 n If Not close. ; I 68 MANUAL OF HTOIENE. If It hu been remarked that moirture, even more than a rfae in tempe^ture, exercta, a verv marked effect in making organL ZZ more perceptible to the eeuse of Bmell. * * ^ M9. The amount of carbon dioxide found in air i» t«k™ as > con ven,e„t measure of all impurities. There are sevenj meftl „" 1 ™,°"="'°'' ''"°™ ■« J-ellenio/er', i, agood o„e but rcouir™ «.a expandHure of much time and labor. It Lust. «,e„ ia iTta Im . .,, '^^ '"'"'' ""'' """"S *e los., of causticity that either of these water, (whichever i, used) has undergone t„W words, the amount of lime or baryta that has united Jth the C^tn TbO T.,r;7r'/ " ""'^ """''»■' » rarkes' "Hygien. » 150 Tlie late Or. Angus Smith's " household process "is a simnler though somewhat less accurate, mode, sufficiently exit, Lever f"; all pracfoal purposes. It may be expressed as follows -1 ' The outs,de air contains an amount of carbon dioxide varvin. between .03 and .06 per cent., but is most frequently 7iZZ^ diffe^mr Jtu:i:s:ftrt: rjtrjiiTw^? t \ r hot les ,n wh.ch a precipitate is just perceptible. It w U be evfdett Ltr?" ""' "-'T'- «- -- iolute amount of "rCn dioxide to form a precipitate if the same quantity of lime walerTj, „^^ 1. used in such case ; and if it be found that it 4es "arge botUeM of air to supply «,is amount of carbon dioxide, this will Slate tla ermZ^b:t:^i"rrcirt"--;-ris:: With water, stirring the slaved 10 11 ^^^ V^T "- wTthrairfd'^--^''^-"-^^^^^^ tbi^ .i» in the lef^hand column; o^iposiCi^Tirtt'^i^L^' MANUAL OF HYQIENB. 69 column, will be found the proportion of carbon dioxide in the given sample of air : — filze of botUi Proportion of •"ounce*. carbon dioxldo in ilr. 20.6 0003 15.6 0004 12.5 0005 10.5 0000 01 0007 80 0003 ''^ 0009 65 0010 6-0 0011 65 0012 61 0013 4-8 0014 45 0015 35 0020 2 9 0025 2-5 0030 20 C040 1-7 0050 1-5 OOCO 1-3 0070 12 OOSO 151. The point of most general interest to remember is, "that the air around houses generally contains about .04 per cent, of carbon dioxide, and that our rooms should always be kept so that a lOi oz. bottle, full of air, when shaken with J oz, of lime water, gives no pre- cipitate. We then know that the air does not contain more than .00 per cent. It is often difficult to keep the air of a room below .07. If a precipitate is observed, we know that the air does contain more than .06 per cent., and we take a smaller bottle, say a 9 oz. bottle, the air of which, when shaken with i oz. of lime water, gives, perhaps, no precipitate. We then say the air is worse than .06, and not worse than .07 ; accordingly the amount must roughly be .07. If we wish to test the air as expeditiously as possible, and are not particular to obtain the exact percentage, we may take a bottle of a size indicative of alternate hundredths. Instead of taking a 9 oz. bottle, we may take an 8 oz., and treat 8 oz. of air in the same mnnner. If we obtain no precipitate, we know that the air is not worse than .08 per 'i ! ' ' i ! >i I I IF 70 MANUAL OF HYGIENE. cent Having already ascertained that the air is worse than 06 we conclude that the air is contaminated with .07 or .08 per cent of carbon dioxide." "If no turbidity is occasioned on commencing with our lOA oz bottle, and we would like to know whether the air contains as much bs ^06 per cent, we must take a larger quantity of air-for example, a 12J oz. bottle. If, when this quantity of air is shaken with A oz of lime water, no precipitate is procured, we know that the air does not we know that .06 per cent, is the amount." "The air to be examined is best introduced into the bottles by sucking out the air already contained in them with a glass tube. Tt r ^", '" '"PP^'^ '^' "'"^ ^' ^^^^*^- The greatest care should be taken not to breathe into the bottle, for our breath is full of carbon dioxide. The bottles should be wide-mouthed, so that the sides can be wiped dry and clean. If the lime cannot be readily removed they should be rinsed out with strong muriatic acid, followed bottles of exactly the capacity required, but tliis could be overcome If there was any demand for such measures, by the special manufac- ture of bottles to hold the quantities of air indicated."-(Dr Fox bamtary Examinations of Water, Air and Food ") ^ ' ' Another way to insure the bottles being till'ed with the air of room. The lime or baryta water should be poured in in such a way as not to be acted upon to any great extent before entering the 152. Of the chemical composition of the organic matter of the air very little is known. The methods of analysis which are at presen most generally followed aim at converting the organic matter of the air into ammonia, the amount of which can be easily calculated The organic matter has been obtained for examination from air by collect mg the moisture, that is seen to attach itself to the walls and windows of crowded, ill-ventilated halls, which has been condensed by the cold air outside. Mr. AH. Smee employs a glass funnel drlwn to a point and filled with fragments of ice= The moisture in tho air is deposited as a dew on the sides of the funnel, runs down, md is MANUAL OF HYGIENE. 71 received in a vessel underneath. (Fig. 24.) This air moisture is examined for nitrogenous compounds, by the Wanklyn, Chapman and Smith process, in a manner similar to the mode in which the organic matter contained in water is detected and estimated.— (Dr. Fox.) A number of other methods are described in Parkes' "Hygiene." 153. The microscopic examination of the dust of the air has received great attention of late years. Dr. Parkes thinks it is probable that in future the micro- scopic examination of air will give more important information even than the chemical examination. The air may be collected by Pouchet's aeroscope; or a good method is to take a small bent tube, wash it thoroughly, dry it, and heat it to redness; when cool it should be placed in a freezing mixture, an india-rubber tube fixed on one end, and air slowly drawn through; the water of the air condenses in the tube, and many of the solid particles fall with it. A drop is then taken by a perfectly clean glass rod, previously heated tc redness, placed on a clean glass, and looked at with an immersion lens as soon after collection al possible. Or air may be drawn through pure distilled water, a drop of which is then examined. 154. ''An aspirator io draw air through the tube is easily made: a square tin vessel, with a tap below and a small opening aoove to receive the india-rubber tubing, is all that is necessary ; fill this with water and let it run down, and measure the total quantity (in a pint vessel) discharged without tilting the vessel. An imperial pint con- tains 34.659 cubic inches, and one fluid ounce 1.733 cubic inches. A cubic foot is very nearly 1,000 fluid ounces, and the ounce may be taken as 1.728 cubic inches. The exact delivery of the aspirator is, therefore, easily determined ; the air should be drawn slowly througli the bent tube in the freezing mixture or through the aeroscope, po that no particles can escape." — (Parkes.) Ajar or can, fitted with a large cork, through which two pieces of Pig. 24.— Smee's instrument for collecting moisture of the air for analysis. i if II T m 72 MANUAL OF HTQIENB. t:f gla.s tubing pa^s one reaching to the bottom of the can and the other barely through the cork, one of them forming an outlet for water and the other an inlet for air, will answer the same purpose 155. A very cheap and good imitation of Pouchet's aeroscope may be made a. follows : Take a small box (a salt cellar will JZ^l:^ IZ r^\"^' ^ °' ^ ^"'^^^ ^^'^ ^-d the same in depth t!iht r f°.vT ' m'' ^"'"'^' "^*' ^"^^^^"-> fittoitan'air: tigh cover of thick rubber, cork, wood with waxed edges, or other similar material. Let two little pieces of J inch glass °tuWr. 1 through this cover obliquely, in a direction from the^outer ends onZ towards the centre at the bottom, one of them impinging on tL i^e above mentioned. Connect this tube with a funnel a^nd the o^e with the aspirator. The air will be drawn through this box ST. particles will adhere te the 'glycerine on wh.Vh fl • ' , . " ""^ oijoenne on winch the air impuiffes The glycerine used should be pure, and carefully kept from 3ust and should be previously examined to see that it is free from particles. 156. A judicious use of thermometers throughout the space to be ^ined will be found useful in estimating theVbility Tf syH I^TZI^T:'"''''''''^''''^'''''- Suchtes'tsofhe'at" power, in order to be as complete as possible, should be made during Z7k th "f r '"' ^" *'^ "^°"'* *"^^^' ■' ^ ^°-P--- «^ the outs d? .nth the inside temperature should be made at the same time. When ^ air IS heated by an open fire-place, it will not do to be satlfi d Jh a record of the temperature taken near the fire, to the excluln of the remoter portions of the room. Again, when the air is heated before entering, it is necessary to take the temperature at t^e pc^nts of entrance and exit, as well as in various other portions of the room so as te see whether the warm air is well difi'Ld or not. Eve^ thermometer should be numbered and graduated on the stem Z sh uld be verified by comparison with a standard instrument. 157. The amount of watery vapor in the contained air, or its hy -ith great variations. 163 The effects on races of a lower mean temperature and qreater variations than they have been accustomed to, Le bl^t J dW the experience, for more than a century, of immigrants from Great Britain and Europe to the various provinces of this Dominion, where health has not only been sustained, but frequently improved, and where the progeny has been a^ vigorous as tkat of the parent race MANUAL OF HYGIENE. 76 164. Extreme depression of temperature tenr' +o produce a torpor of the mental and physical faculties which, if yieic.ed to, results in death. By its action in depressing the vital powers and constrin-ring the minute blood vessels near the surface, cold gives rise to con- gestions and inflammations. Apoplexy, from this cause, is of more frequent occurrence in winter than in summer; bronchitis, inflamma- tion of the lungs and of other organs, diarrhoea and rheumatism are often produced in this way. 165. The effects of extreme heat are strongly marked. When con- tinued for any length of time diseases of the liver, diarrhoea, dysentery and fevers are induced. The eflects of the sun in very hot weather on persons engaged in out-dooi- work, or on soldiers on the march, have often been of a very serious character. Sun-stroke, producing conges- tion of the brain, and a peculiar effect on this organ and on other parts of the nervous system, is often the result of intense heat especially when prolonged fatigue has been endured. 166. The effect of the direct rays of the sun requires consideration Do they aid or clieck perspiration ? That the skin gets dry there is no doubt, but this may be from evaporation alone. Tf, however the nervous currents are interfered with, the perspiratory vessels and the amount of secretion are sure to be affected in consequence. If this is carried beyond a certain point, the heat of tlie body must rise and supposing the same conditions to co itinue, viz., radiant heat and want of perspiration, it must pass beyond the limit of the tempera- ture of possible life, viz., 113° Fahr. 167. That intense heat acts fatally by destroying the muscular energy of the heart and diaphragm, or midriff, a- pears to have been proved by experiments of the late Sir Benjamin Brodie on the lower animals. The effects of a high degree of atmospheric heat are wit- nessed on a large scale in the deserts of Africa and Arabia where caravans of traveller so freqjontly ruffer from long exposure to a lurning sun, r.nd quite, rece rcfy in the case of the British troops engaged under Sir Gerald Grauun a: the Soudan. 168. Of rapid changes of tempi^rature, the exact physiological effects have not as yet been satisfactorily traced. These vicissitude, mwi be met by alterec! clothing : persons should dros., not for the season of the year, but for the existing condition of the weather. A sud i)' lili il 76 MANUAL OP HTQIENE. den checkmg of a profuse perspiration by cold winds may lead to catarrh, inflammations and neuralgia. Great changes of temperature Dirp/! ^]^\:^f^^'' «"«»^ -« -* Denver City, Colorado, or ai Davos Platz, m the Upper Engadine, Switzerland, may be, and often are, borne without ill effects, even by consumptives, who, either in arnages or walkmg. are out in ike open air a large portion of the uay. 169. Sunlight is essential to the fuU development of -animal and vegetable w Plants deprived of its influence become blanched |tnd stunted. Animals are similarly affected. The tadpole develops into the frog very slowly or not at all if kept in darkness. Pro- fessor Milne Edwards, in his work on the "Physical Agents of Life " records experiments on this point. He came to the conclusion thit the action of light is to develop the different parts of the body in that just proportion which characterizes the type of the species. It is almost invariably the ca^e that those parts of animals nearest to the ground, and consequently least under the influence of light, are white or colorless. The brilliant colors which belong to the plants aid animals of every kind found in the tropics are loubtless due,t pTr at least, to the influence of sun-light. The importance of li:ht fn a hygienic point of view is not sufficiently estimated by most persons. 170 ndlVldualS deprived of it from an early age are generally of a low vital power. The offspring of such are frequently deformed aid are always weak and puny. From the observations oJthose who h^e given attention to this subject, there appears to be no doubt thi scrofula IS often produced in children by the deprivation of the sui^ -ys. Professor Lombard, of Geneva, very truly says that ull stimulates, and darkness impedes, respiration, and, through respfrt tion, animal heat and muscular activity. ^ 171. Etiolation is the term often applied to the condition of persons deprived of the sun's rays, and is well described by Riembault in^ "Hygiene des Ouvriers Mineurs." According to this author ]tZ cWtenzed by a diminution of the fibrin, the albumen and the red globules of the blood while the water is augmented in quantity The face IS discolored, and acquires a tint analogous to that of yellow wax The veins of the skin are no longer to h« n»r-^.,-„.^ .1 ?^^''- MANUAL OP HYGIENE. 77 parts where they are largest and most numerous, the pulse is frequent, and palpitations of the heart and extreme prostration occur. 172. An excessive amount of sunlight, on the other hand, is not only injurious in certain diseased conditions, but is also capable of pro- ducing disordered action in persons who are in a good state of health Persons much exposed to strong reflection of the sun's rays from the sand or snow are very liable to ophthalmia or to snow-blindness. 173. Sunlight in convalescence from almost all diseases acts, unless too mtense or too long-continued, as a useful stimulant, both to the nervous and physical systems. Experience has shown that health IS promoted by giving the sunlight a fair opportunity to penetrate mto every nook and corner into which it can make its way In dwellings It is desirable to give as many as possible of the living and sleeping rooms the benefit of abundant sunli^at. This is usually secured by giving them a southern aspect. Broad verandahs, heavy vines traUed upon trellises, and overhanging shade trees, are very attractive and beautiful, and are often comfortable durii.vell established by observation. 1. It is most potent at its place of oricrin. 2. More noxious during the night than during the day. 3. Its greatest activity is at the rising or setting of the sun. 4. It is capable of bemg moved by winds from the places where it is formed to others which in themselves are healthy. 5. It exhibits a great affinity for water. A situation even to leeward of a focus of malaria will suffer comparatively little from fever if a sheet of water intervenes. Drink- ing the water of marshes sometimes produces fever. 6. Malaria has an attraction for trees and other forms of vegetation; therefore, the planting of trees or shrubbery in the immediate vicinity between the originating point of malaria and the place to be protected will, in a great measure, prevent its access. 7. The first turning up of the soil leads to malaria, but continued cultivation causes it to diminish in violence. 8. It is prevented, in a great measure, from exercising its deleterious influences, by fires. 9. Small daily quantities of quinine also act as a preventive. 181. Dwellings and SChool-houses should be built as far as possible from all sources of malaria, such as stagnant water, mill-ponds, ditches, etc. Low situations should be avoided, and the floor should be raised from the ground. To prevent soil-air from ascending, the spaces intended for buildings should, after drainage, be covered with, first a layer of charcoal and then one of good concrete of suflicient thickness and durability. Sites should also be chosen with reference to prevailing winds, so as to be to windward of all sources of malaria. If the neighborhood is one abounding in these, such as mill-ponds and undrained lands, it would be ^ell for the school-house to be so placed as to have an intervening sheet of water and a row of trees between the water and the building. If there is, in a malarious region where a school-house or dwellings are to be erected, any elevated ground, it should be chosen for the site. Even a few feet may lessen danger, but only at greater heights can complete security be obtained. The elevation of perfect security in different parts of the world is not definitely determined ; but it appears to be in Italy 400 to 500 feet ; in South America, 3,000 feet; in California, 1,000; in Indis, 2,000 to 3,000 ; in the West Indies, 1,400 to 2,200 feet. 182. Soil consists of the layer or crust of earth more ov less mixed 6 f i 1 80 MANUAL OF HYGIENE. with remains of animal and vegetable substances in a state of decom- position. 183. The chemical composition of certain soils has an important bearing on health. Alluvial soils, rich in organic matter, are, com- paratively speaking, unhealthy. They aid in the production of mala- rial and oth"r zymotic diseases. Granitic rocks, whilst they are generally healthy, have been known to produce similar effects when undergoing a process of disintegration. Sands also differ according as they hold organic matter or not. The banet'ul influences of " made soils" will be fully considered hereafter. The water of lime-stone formations is apt to give rise to goitre and calculus. The water- supply of alluvial soils is often alkaline. 184. The mechanical structure of soils has a very marked influence- Clays and marls are unhealthy, on account of their retention nf water. When they underlie alluvial soils they intensify the unwholesome influences of the latter. Marshes are common under such conditions. Whilst a structure of -r. .-^^s and pure sands is in itself conducive to health, they may hav rposite effect in connection with the "con- veniences" of huic/-:7 "I'iiation. Their very structure favors the interchange of the cotiwrits of filth-receptacles and wells, and the pollution of the ground-air and ground-water. The germs of typhoid fever travel in a lateral direction in sandy and gravelly soils. These results are still further increased if a substratum of clay or other impenetrable material underlies the sand or gravel. If, on the other hand, such soils have a good slope, and are kept clean, and the drink- ing water is properly protected, the natural drainage which takes place in them renders them very healthy. This last remark will apply also to hard soils, such as clay-slates, limestone, sandstone, and the purer kinds of chalks. 185. The configuration of the soil, it will be found, has influences no less marked. We can easily see how the circumstances of hill or plain, regular slope, ravines and water-courses, affect the disposal of the ground-water and of the products of human habitation. Hill and plain also produce difl'erent results as regards the action of winds, rain and snow ; whilst the direction of the slope of a hill will affect its climate. The fruit-grower is well aware of the advantage of a south- em slope, especially in the cooler seasons of the year. MANUAL OF HYGIENE. gj^ through it ^'''^ ^'^^^ P''""^'^^^^ ^'•^"^ blowing alluvial soil Th. , 7 ^ ^"^^"^ ''^^ «^ » region overlaid with dep::!:: '"" ^""^'^ '^^^^" ^« «^*- -pp^-^ t. such 188. Air In the SOll.-The hardest rocks are alone free from air r - l^O "-■'. *e.e being a constant ^nV?1Ce1i:'int the wa™ houses .W. To p-event this is a ..tte. Z2.Z;:n. 1 1 ; » J! Ml IMAGE EVALUATION TEST TARGET (MT-3) V ^ /. {/ y. r/. 1.0 I.I 11.25 2.5 IIP 2.0 iA III 1.6 V] <^ /^ o? ^> C Sciences Corporation 23 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 872-4503 4^ iV ^> -^ '%' fc i/. ^ .1* 8S MANUAL OP HYGIENE. anoo, and it should be accomplished in the manner indicated in Sec. 181. Even on the purest soils it is desirable to observe the rule of cutting off the subsoil air from ascent into houses. 191. The power of soils to absorb water constitutes another import- ant point in their hygienic relations. Some soils are much mere retentive of water than others, and on this account exert a ueleterious influence on health. Two circumstances conjoin to influence this hygroscopic property, viz., the porosity of the soil, and the proportion of deliquescent salts which enter into its composition. The following table of the power of different soils to absorb moisture is tiken from M. SchiJbl-jr's experiments : — KIND OF EARTH. (600 oentlgranimes of each kind being spread out to absorb inoiBture.) Silicioi' a sand Gypsum Calcareous sand Light clay Heavy clay Calcareous matter in fine powder Argillaceous ear+'a Pure clay Humus or surface soil CBNTIORAMMES of M0I8TURB ABSORBED. In 12 hours. 0.0 0.5 1.0 10.5 12.5 13.0 15.0 18.5 40 In 24 hours. 0.0 0.5 1.5 13.0 15.0 15.5 18.0 21.0 48.6 In 48 hours. In 72 hours. 0.0 0.6 1.5 14.0 17.0 17.5 20.0 24.0 55.0 0.0 0.6 1.5 14.0 17.5 17.5 20.5 24.5 60.0 192. Humus, or vegetable mould, is pre-eminently distinguished for its power of absorbing moisture, and it may be well to allude briefly to its distinguishing featur-.-s. It is a dark, unctuous, friable sub- stance, nearly uniform in its appcai-ance, resulting from the slow decay of vegetable and animal matter— a compound of oxygen, hydrogen, carbon and nitrogen. Good samples of it are garden mould or the Biould of old neglected dung-hills. It renders stiff" clays porous, and consolidates loose sands. It will be thus seen to be the worst possible soil on which to place school-houses or other buildings intended for habitation, unless the precautions against admission of ground-air and dampuoss previously aUuded to are taken. More particularly is it ILiNUAL OP HYQIENB. 53 %hly objectionahle if the sub-soU is formed of clay. Rain which enters on such ground, instead of evaporating, soaks through the first stratum and passes mto the clay, is absorbed, and causes the surfac to remain for a long time damp and unhealthy 193. Water exists in the soil either a. moisture or ground-water. When air as well as water is present in the interstices of soil it is termed ground moisture. P.ttenkofer's description of ground-;ater 08 tnaf. all the mterstices are filk: with water, so that, except in so far as Its particles are separated by solid portions of .oil. :here is a con- tmuous sheet of water. This is at very different depths below the surface in different soils, sometimes only two or three feet from the surtace, in other cases as many hundreds. TJ is sheet of water is in constant movement. Pettenkofer reckons its rate at fifteen feet daily Its level IS constantly changing. The causes of this change are, rain- fall, pressure of water from rivers or seas, and alteration in outfall either by increased obstruction or the reverse. ' 194. Marked diminution of sickness by drainage ha^ been noticed in malarial districts, the increased outfall lowering the level of th. ground-water. The prevalence of typhoid fever, cholera, and othei- diseases of a zymotic chamct.r, is believed to have an intimate relation with the level of ground-v^ater, especially -hen after having nsen to an unusual height it rapidly falls. Assuming the truth of this connection, the other conditions which Pettenkofer consider^, necessary to their production are impurities of the soil from anin~ J impregnation, and the entrance of specific germs of the several diseases mto the druifcmg water. "co^t^s .i™ ^; hf ,' •'•,'" '""'•fP'oity 'or absorption, retonfion and radia- Kind of Earth. *'**'""^' °' '■et«'nlnir heat Calcareous sand *^''* °' """"^ •"«'"» ^'^^ Silicious Band ^^'^ Lightclay '.Z'.'.'..['.'.'..'.[[ J^S Gypsum l^'^ Heavy clay ...ii'. ..!.....*.'*.'.*.*.' Jj ? Argillaceous earth „': Pureclav ^* Calcareous matter in fine powder . " ' * ' /,, "» Humui ®if 49.0 4 ! :l :ii -B4 MANUAL OF HYQIENB. In camping out a sandy soU should, therefore, he selected for the bivouac. 196. The influences of vegetation vary. Herbage is generally bene- ficial, especially if it be periodically removed by cattle or in the form of crops. Cultivation and drainage are useful in this way, the improvement of malarial regions often being veiy marked, especially after the baneful effects of first breaking the soil have passed away. The cultivation of rice fields by irrigation and flooding is, of course, an exception to this rule. Brushwood is not generally found to have a healthy influence It does not allow of the free action of the sun and rain, and the dead leaves slowly decay, and give off unwholesome exhalations. In marshy land, however, it also tends to intercept the malarious exhalations and should not be disturbed. The late Dr. Parkes paid much atten- tion to this subject in connection with military camps. He advises that in those cases where the camp is only a temporary one, the brushwood be not removed; but if the camp is to remain in the neighborhood for a long time, and the brushwood is not doing service as a screen against marsh exhalations, then it should be removed This removal should be made when the sun is high, and not in the early morning nor in the evening. It might also be added, that it is less harmful to disturb such places in winter or summer than in the spring or autumn. Trees are generally useful in rendering the moisture in the air and soil more equable. They also convert large quantities of carbon dioxiae into oxygen. They act as shelters from bleak and unwhole- some winds ; sometimes, on the contrary, they prevent the passing away of the latter by free perflation. Their influence is siaUarly variable in shading us from fierce heats on the one hand, and shutting us out from the benign influence of the sun on the other hand. Hence their removal or detention must be determined upon after a careful and judicious consideration of aU the circumstances ii each individual case. 197. Winds have a very great influence on health. Through the action of the almost constant currents which are excited by the vary- ing density of the atmosphere, the air which has become contaminated with organic and other exhalations is removed, to make way for that sh MANUAL OF HYGIENE. 86 "I^ u" f '''''*''"^' *^" ^°™^^ ^^«""t of oxygen. On the other hand, winds often serve to transport malarious emanations and specfic germs of disease to great distances. Epidemics of small-pox and other infectious diseases have been traced to the burning of con- taminated clothing in the open air, instead of in stoves or furnaces as also to dissemination by the wind of the dried pustules and scales' of the different contagious diseases from the hanging of infected clothing to dry after washing, the temperature of the water not having been sufficiently high for the destruction of infective -erms 198. The direction from which a wnd blows modifies its character An east wind generally brings moisture with it, and is, therefore' liable to induce catan-hs and rheumatism. South winds are often hot' dry and enervating. North winds occasion a great reduction in tem- perature. In Switzeriand it is held that a north wind very .p.^dily drives away influenza. In Italy, and along the north shore of the Mediterranean, a very relaxing wind 'rom the south-east, called the Sirocco prevails in the early spring. The north-west wind, or much- dreaded Mistral, :-s occasionally experienced with great sev-^rity in some places on the north shore of the Mediterranean, especially at Cannes, Hyeres and Nice. The north-east wind, or Bii, coming from t.e Arctic i-egions, is very cold and dry, .os moisture being lost as It blows over the Alpine mountains. The Simoom is a noxious wind of the deserts of Africa and Asin, not periodical, and lasting but a short time. Animals of all kinds instinctively flee for shelter at its approach, or crouch to the earth until it has passed over. This wind carries with it a fine sand, and is irrespirable. Its deleterious effect IS presumed by some to be increased by the presence of sulphurous acid 199. Electricity is another factor in climate. By some it is con- sidered that up to the present time we are ignorant of the part played by this agent either in the preservation of health or pro- chiction of disease; by others, that the importance of atmospheric electricity as a curative power in disease is not to be measured by the little we know about the agent itself; that electric tension in the atmosphere is, as a rule, increased with each decided elevation above the sea level, and that the increased electrical influence of the atmos- phere of high altitudes is one of our most important aids in the battle against consumption. i d6 Manual of hygiene. I 200. Ozone, a constitue.,f, of the air, alluded to in Sec. 47, is formed p e^ :::: ^'""^ y.^^^-^f - ^uld passingthrough'ther:' phere. It was supposed by i>rofessor Schonbein-its discoverer to and also that cholera was in some manner connected with it as clunng ep,dem.s of that disease there was found to be a min mu" amount present in the atmosphere. No sufficient evidence on th^ subjec has n. yet been adduced. It is most abundant in sea aTr and >^inds, and m the winter season; more so in the country than in populous p aces, and at night than in the daytime. bein/especTal y abundant about daybreak. Some observers say tha it ha^ an'rS mg action upon the air passages. _ 201. In high altitudes the pressure of the air is lessened, evaporation s more rapid, and the vapor is less perceptible. The clearn s so" he air IS also rendered greater by the increased facility wT; L, radiant heat is transmitted in such climnf o.. At elevation, vl from 5,000 feet upwards, as at Davos riat, in the CrEn^S^^^^^^ soon after sunrise the temperature rises, because of the U sliS resistance which the rarified and dry air offers to the sun's rays, vht afr sunset the terrestrial radiation is also rapid, because ther is no moist envelope shrouding the face of the earth. Comparinc. the .1 7 .nimical to life in mines, cellars and ill-lighted aboZ .S ^^^ of unhgh at low levels, where a stratum of moistu e intercepts'L sun's rays like a thin cloud, and then with the healthful inflences the unobstructed sunshine of high lands, it may be said that the beneficial effects of sunshine increase with increasing altitude 202. That cool, dry climates and high altitudes are far better for con sumptives than warm, moist ones at the "sea-side," or on tropical low- ands. the experience of Dr. T. C. Williams would seem to establYsI In his Lettsonian Lectures we find an analysis of 593 weeks spent by 251 consumptive patients in foreign climates. Dr. W savs • -Z 7 what class of patients profit, most by dry climates, it has'been sholm that, taking collectively all forms and degrees ^f phthisis thlT climates are the most likely to arrest the disease " As tn fL ^ • bUity of moist climate, for consumptive vZ^,T^^l MANUAL OF HYGIENE. 87 phthisis The addition of warmth only makes the damp tell more unfavorably, though a strong saline element and invigorating brrel do something to counteract the humid influence. Stilf, even 'these d" not make a mois climate compare favorably with a dry one. „n! 1 1 f^ ''''°''*' °' ^^""''^ ^^« sufficiently known to render any lengthened remarks unnecessary: whether on the salt water o the Lower Provinces, or in the lake districts of Muskoka and Central OnW, or on the shores of the Georgian Bay or of the Great iTket they are invaluable as summer resorts on account of their invigorating influences. Of the other marine climate in our Dominion to bf open"! up by the Canada Pacific Railway, vi., Vancouver's Island aj the adjacent coast, including the lower Fraser River, it may be said that i ^never very cold in winter nor very warm in summer f the nights a^e cool Some winters pass without snow and with very little frost but ^th a good deal of min. From June to October the'air is warm and genial. During these months, as a rule, little or no rain falls the rainy season being from November to March. From the grea 'rain all during his period the atmosphere is heavily charged with mois- ture The thermometer rarely falls below freezing point, but there are frequent cold and variable winds. .l^f '^^^'••*i^^Columbia has different altitudes so it has different clunates. In the interior of the mainland there are ranges of moun tarns varying lu height from three to four thousand fee^ and many still higher covered at the tops with perpetual snow; sloping inwal int ; n 1 " ' "^ '^'' ™"^"^^"^' resembling that of the interior of Canada, is very warm in summer and very cold in winter The winters, although cold, are very sunshiny, and^he atmosphere clear and bright. Therefore, either on these lofty ranges on the mainland, or on the foot-hills of the Rocky Mountains beyond Cal gaiy would invalids fron, lung diseases be more likely to be ben . fitted than on any part of Vancouver's Island. It is very probable iteoffrP "V;"""" '"^^'' "^°^*^ ^^y ^« esUblished on the line of the Canada Pacific Railway. II CHAPTER VIII. NATURE OP REFUSE SUBSTANCES-EFFECTS WHICH THEY MAY PRODUCE- DESIDERATA IN THEIR REMOVAL-VIOLATIONS OF THESE. 205. We will consider this subject under the following heads :- 1. The nature of the substances of which the refuse of households and of communities consists, and the effects which these TT rr^^^ ^^^"''^ """ *^® surrounding air and water. 11. The desiderata to be kept in view in the disposal of them, and v^dlted ^^^' ^ ^^''^ *^''^ desiderata are commonly III. The various methods by which they may best be carried out and the principles to be observed in connection with thesJ methods. IV. The ultimate disposal of sewage after removal. households ^- '"""'"'"^ substances are comprised in the refuse of (a) Ashes, dust, waste paper, and other dry refuse, not liable to become prejudicial to health by speedy decomposition. 6 Kitchen slops and vegetable and animal refuse, -garbage (c) Bedroom slops. * ' (rf) Excrementitious products not included in the last division. heZW ! """"^ °^ **"''' '°"'* '''^'^'""S ^f ^«f»«« ^« that which IZZZ rTVt^''''' *^ P^P^^^*^°"' ^^^^ '- — t. char- acter and effects. A slight calculation will show us how much more important It is than people generally suppose that there should be proper and systematic methods for the disposal of sewa<.e 208. By a computation based on the observations of physiolo^^ists it ^11 be found that the solid product of 500 people, in a'mLd p puW T^LTr^M ,'T '''^' ^T' ^""■'^'"^^ *« ^^^^-' - 1« tons if we take Franklands figures; and the liquid to 7,323 cubic feet. In a thickly settled portion of one of the cities of this province, ei«hty- MANUAL OP HYOIENE. 89 five houses have been counted iu a block 67 yanls wide and 200 yards long. Assigning an average of six inmates to each of these houses we would have a population of a little over 500. In other M'ords on a space of 67 yards by 200, in a region thickly studded with houses, we have stored at the close of each year an additional mass of from U to 18 tons of sohd excreta, and enough liquid to fill a tank the dimen- sions of which are 20 feet each way ; or passing to the purer atmos- phere of a country village of 2,000 inhabitants, we would have pro- duced 57 tons of «•• lid, and over 29,000 cubic feet of liquid excreta 210. The total amount of filth of communities may be better esti- mated than it usually is, if it is borne in mind that the excreta of human habitations, great as it is in amount, is considered by sani- tarians to form but a small proportion of the whole. 211. Among the effects produced the pollution of the air may first be noticed. The three classes of substances last mentioned in our enumeration pollute the air directly by the emanations arisincr from Sli u """^ decomposition they evolve large quantities of glses 212. Myriads of low organisms are also given off, and amongst them, germs of disease. Many of our most common zymotic diseases, such as typhoid fever and diphtheria, are propagated and spread h, this way. Disease germs may be given off even before decomposition occurs These gases and germs may be taken into the system, and act directly on the human organism, producing diseases of a definite nature; or they may rob the air of so much of its oxygen, by com- bining with it, that they lessen its power of restoring the blood and tissues to a healthy condition, and thus cause a general deterioration ^13. The soil, too, becomes filth-saturated, and the ground air being constantly drawn into and expelled from its interstices, passed out, laden also with germs and impurities. 214. The filth carried into wells from the surface and through the soil IS the cause of a large amount of the typhoid fever, diphtheria, and other zymotic diseases which occur amongst us. II. 215. The points to be aimed at in the disposal of sewage are •- («) To remove all the waste products of households that are liable to become injurious to health by giving off gases or disease germs. (o) ±0 remove them completely. (o) To removfi them be/ore they can decompose. 'I U 90 MANUAL OP HYGIENE. (.) In their method of removal to take care that the ease, »hieh ~hr 7 "°'.'"°"'' '" '"""■°°'»«- 1- "- -t; a:t! :Cef:;i:';- -^ '™ -*«- '>■»«'. -or. d^,^: (/) That in this la.t named system means be provided to direct the necessary escape of the gaseons contents of sewers to^inTs whTe but decomposing masses of the most offensive filth 7 T . year after year in pits dng in i, with thflZ Tori ed Iw L'Ttrcexnrffect^o^rr '^ *^ t"'-'°» °^ *e^^ u.csofepideLcsX!:tr:tore iit'rTf^^ cond.t,„n for the „>pid spread of any epidemic is th^s p'vided ^m. That removal should be cmplete is the second p2ll^le Ui attention is paid to secn4 a gL fl* iontrir tnT": ^mesazig-sagontline, the pipes ".nning altemaw; „p ^ dow^ The connections become broken or opened out whiict ,T ttough wluoh „ts work their way. leaving openings into thedS MANUAL OF HrOIENE. 91 Brick house-drains— which sliould never be used now— are often opened by rats, and discharge sewage into the soil. Cases are known in which sinks have been put into houses, the ends of the waste-pipes carried through the floor, and no attempt made to connect them with drains. As an example on a large scale of similar neglect, we may refer to the Toronto Asylum for the Insane in days gone by. An unusual amount of sickness prevailing in that institution some thirty years ago, led to an examination of the drains. On taking up the floors, an immense amount of sewage was found, and it was discovered that the contractor who laid the inside drain and the contractor who laid the outside one had failed to arrive at such an understanding as would lead to a connection being made ; several feet of earth had been left between the two drains, and the sewage of years had accumulated under the floors. In all cases of soil pollution or surface pollution under houses, or in their immediate vicinity, we have to bear in mind that the heated air in them creates a constant "ascensional" current, drawing and carry- ing with it impurities originating below. 218. Delay in removal till decomposition occurs results from many of the causes already mentioned ; also from drains having too little fall, being insulficienty flushed, or having junctions improperly made and allowing of deposit. Even though the sewage be completely removed after a time, yet the delay in removal gives rise to a generation of foul gases, with the results before described. 219. That there should be a suitable outfall or , per place of deposit is our fourth requisite. Where sewers are used, they should not pour forth their contents in places so situated that offensive and injurious contamination of the air or drinking water of populous districts must result ; and, furthermore, no decaying, decomposable or offensive materials of any kind should be deposited in situations where they may do harm. In some towns in this Province (as elsewhere) epidemics of typhoid fever have been traced to improper outfall of sewage. In one in- stance the water supply was affected thereby ; in another, a small creek flowing slowly through the town is transformed into an open sewer. In another, a prolonged discussion took place as to whether water-closets should be connected with the town sewer. The ! n !^ n 92 MANUAL OF HYGIENE. •luestion wa. wisely d.ci.lod in the negative, on account of the want of proper outfall, and for other reasons. 220. Scores of "eligible building sites" are made up of the remains o cats and dogs, the en.ptyings of straw ticks, kitchen refuse a^d other decomposmg anin.al and vegetable matter. When the gra^s ha^ covered the surface of these lots they are as pretty to look at as an^ otlu,rs. Provided the houses erected over then, are placed on posts and a free crculation of air underneath the iloors I secure ,Cn n ay not result; but it can be readily understood that if the walls are sunk into such n.aterial, the constant up-draught of the heated air of the house wdl draw up the gases and low organisms which abound in such a soil. The visitation of that memorable epidemic o yellow fever which took place in Memphis a few years ago w^ partially attributable to the deposit of garbage in the L. ^ ' gases and germs of disease accumulate, and do much harm. It is found that with an ill-ventilated system of sewerage the higher and once more healthy, districts of a city often become'the more p Ili^ claimed by some that in the small glased-tile sewers of the separate system (see Sec. 252) no decomposition occurs : in this case the'Z I wouTdbr :: r '^ ^ 'r'^^ ^" ^ ^^-^^^^ ^^^ ^« ^^^y ^^^ typhoid fever, cholera, sca.-let-fever, small-pox, etc ciusue proof of the absence of sewer gases. Some injurious cases ^veal themselves unpleasant:, to the nose, w-hile otLrs doTot These last are so msidious in their nature as to be doubly dangerous As examples, the baneful results which ensue from living in housed under which water lodges and becomes stagnant may be refLedTo r^t ts Vrm-" ": P'-*'*--- -ho have not witnessed these results. The miasmatic poison of ague is similarly inodorous, or has no necessarily unpleasant odor. In like manner sewers liav som" tnnes very little unpleasant smell. In some cases we have I leU somewhat sin^ilar to that produced by those burning fluids into the compositiono which fusel-oil enters. People living i^ a house blme «o accustomed to these faint odors as to take little not,Ve of tl e^ MANUAL OF HYGIENE. 93 and with Bome people the sense of smell is not very acute. Hence we must be very careful how we accept negative evidence as to the pres- ence of noxious gases. And hence, too, we must be all the more care- ful to avoid their existence and presence, and to devise means to this end. 223. Among the gases more commonly evolved from .sewers may be mentioned sulphuretted hydrogen, carbonic acid, carbu retted hydrogen, nitrogen and ammonia. IVIany cases of asphyxiation in sewers and cess-pits are on record : no loss than eight deaths from this cause have occurred in the sewers of Chicago within the past year. 224. The causes operating in the evolution of sewer gas, besides those acting more generally, such as the natural ditfnxion of gases are : — ' 1. Difference of temperature between sewer and external air, causing a rapid interchange in accordance with the laws w.utin regulate the movements of unequal weights of air. 2. Upward draught in houses acting as a ventilating shaft, in the wake of which the sewer air will follow if allowed. 3. The expansion force created by the sudden accession of heat in the drain, viz., by pouring down hot soap-suds or boiling water. As the air expands the pressure is increased. If, then, the temperature of the air in the drain be raised from 50° to 150°, the" result will be a pressure of 6/5 feet head of water, enough, it will be seen, to force any trap, unless some other means are provided for its escape. And this rise of temperature is not at all an improbable one. 4. The flow of water into the drain causes an expulsive force. When water is poured into a drain it must, of course, displace its own bulk of air (less the small amount gained by compression), for two bodies cannot occupy the same space at the same time. Out of which end of the drain (supposing that it has no ventilator) this air shall pass will be determined by circumstances ; it passes most readily where it meets with least resistance, always giving preference to an upward direction, owing to the greater gravity of the water. Storm water suddenly filling the sewers acts powerfully in this way. This ebb and flow operate like a double-acting piston or syringe. Partial choking of the drain gives rise to confined air constantly increasing, expaiidiiig and being displaced. < } \ Hi 94 ll'L' fiii MANUAL OF HYGIENE. 5. The rise and fall of sewage in the drain also cause an increased generation of gas by the constant evaporation arising from the alter- nate wetting and drying. 6. The wind blowing up the sewers will force the sewer-gas back- wards. Some engineers have proposed flap gates at the mouths of sewers. But it is better to let the fresh air blow up, and make suffi- cient vents for it to sweep through and purify the sewers. 225. We find sewer gases disposed of in various ways :— In a very large number of cases they escape into dwellings. In some instances they are supposed to discharge through gratings in the centre of the road, but in many cases they discharge at the edge of the sidewalk through untrapped gullies, or through gullies the traps of which have been emptied by evaporation or leakage. The errors which are most frequently coming under notice as detrimental to health are those which allow of the 226. Entrance of sewer gases into houses.-It has been well remarked that " unventilated sewers are more dangerous than steam boilers without safety valves." In one of the towns in which there was a violent outbreak of gphoid fever, calling for investigation by th3 Provincial Board of Health, box-drains were found, without any trap or vent, bringin<. up the gases from a larger box-drain with a broken bottom, which contain- ed portions of the contents of cess-pools which flowed into it Some mechanical impediment to the return of sewer-gas, technically known aaa "trap," should be placed as near as possible to the commence- ment of every waste-pipe. Various forms of these will be described 'leieafter, as also the best means to be taken to prevent their becoming useless. _ Sewer-gas often escapes into houses through bad connections and jomts m the mside plumbing, or from corrosion of pipes, or from imperfections in connection with traps. (See sees. 253-261 ) 227. The ventilating of the sewers at the level of the road-bed brmging gases and germs up at the feet of wayfarers, and opposit^ doors, windows and air-du 3ts, is also a violation of the sixth point laid down. In a report by Mr. Sedgwick Saunders, published some time ago in Tlie Lancet, he attributes to sewer-gas, arising from ventilators in the road-bed m some of the narrow streets of Loudon, cases of typhoid i Hi ■ MANUAL OF HYGIENE. 96 ever and sore throats, and "suggests an abatement of the evil hy the closing of the street ventilating.gratings entirely and the erlctilu upnght shafts, six inches in diameter, to be carried abov t e ol of the adjacent houses." I am sure that it has occurred to mlv o us to not.ce the disagreeable odors that sometimes a s frm'tll street gratmgs or from the unsealed traps of gullies. Somet meT to^ we are more than usually impressed with the reality of th eX Kt"": of sewer-gas by the sight of columns of vapor 'rising fottl gratings and gullies, and rendered more visitle by the%o.K ion o the atmosphere on a cold, damp day ; but we shoukf bear in mi Uha gases and germs often proceed from sewers even when ^' . ^ o apparent to sight or smell. ^^^ Some speak of the placing of charcoal-trays in the ventil-itor. •,« sufficient safeguard. Even were the charcoal conslnt y J y ^ gas at times makes its exit too rapidly for the charcoal I ov;.^ y action upon it. So that, however useful an adjunct charcoal may b ' cannot be considered a preventive to the injurious effects of sei. I'a Besides ventilating by gratings in the road-bed is not to be reHed onin winter : they become clogged or closed by ice and frozen n.ud 228. In some cases the sewer-gas is discharged above the house- tops. Proper consideration will show that this is the correct method It s surely safer to d scharge it away above our heads than at o L i T . '' '""'"'^^'^ '"^ '^' '^'^Srara on page 107. 229. The drinking water of houses is often polluted by the water- closets and urinals of a house being supplied directly from the 1 tireToff th^'" " "'f ;' ^^ ^'^^™'- ^^-times'the prossu " taken off the pipes, and they become emptied of water and draw in air from the closets. This air may be foul or contain germs od- ease, and it may become mixed with the drinking water and produce di3as rous results. Instances of this are cited in the reports of the Local Government Board of Great Britain. In Caius College Cam bndge, a severe epidemic of typhoid fever was caused in ti^L way a though the air had been drawn in only once or twice. Absorpt n of sewer gas y tanlcs containing drinking water has repeatedly g' v .i se to trouble. Closets and urinals should always hive thcL own «en.™>. tanks, and the water from these should never be usedTr 3urposes, nor for washing milk p.ns and other similar utensils. drinki I ,U ! I 1; i 1 « i i S a I! CHAPTEB IX. SYSTEMS OP SEWAGE DISPOSAL— DRY METHODS—WATER-CAHBIAGB SYSTEM— PNEUMATIC METHODS— ULTIMATE DISPOSAL AND UTILIZATION. HI. 230. We may divide the methods for the disposal of sewage in accordance with sanitary principles under two principal headings- "Dry Systems of Removal" and tJie "Water-carriage System," or, as they are often called, the dry and wet methods. We may also give a passing notice to certain Pneumatic Systems. Attention will first be directed to the best methods of disi)osal in those cases where the water-carriage system cannot with advantage be adopted. 231. In the dry systems the liquid refuse is kept separate from the solid, and the two are disposed of in different ways. It is a matter of common observation that solid organic matter, if kept comparatively dry, is not subject to offensive putrefaction, while the reverse is the ca^e when there is a certain quantity of water present; a practical attention to this fact in dry systems of dispo^l will obviate those putrefying masses which now form such offensive abominations in our midst. The subject naturally divides itself, then, into two portions, wliich require separate consideration, viz. : the disposal of (a) solid refuse, and (6) liquid refuse. 232. Of the various methods for the disposal of solid excrement there are three which seem to have met with a fair degree of success These are (1) the Hull Ash-closet system ; (2) the Dry Earth system '■ (3) the Eochdale Pail system. 233. In the Hull Ash-closet (Fig. 25), the back, ends and floor of the receptacle under the seat are built of brick, laid in cement. The front IS fv movable wooden piece, and the seat may be hinged. The floor is MANUAL OF HYGIENE. 97 not sunk below the ground level, but slopes slightly from front to back. The whole is properly roofed in and ventilated. In the same receptacle are also deposited all the ashes, dust, waste paper and solid kitchen refuse. All kinds of slops are rigidly excluded. When it is considered desirable to screen coal ashes, they may be screened into the closet after raising the hinged seat. 234. In Manchester a modification of this system exists, the floor being made level and a pail being used, with ashes, as in the HuU closet. In some instances a fixed cin- der sifter is arranged at the side, which directs the ashes into the pail and allows the cinders to fall into a box. 235. A modified form of the dry-ash closet has been used successfully in some parts of the United States and Canada. In it two pails are used one under the seat and the other in some convenient position for the ashes. Each time the closet is used a quantity of ashes is thrown iu with a scoop. The above are all out-door closets. 236. The Dry- Earth system is sub stantially the same as the dry-ash system above described, earth being substituted for ashes. The earths best adapted for the purpose are moulds and loams. Pure sand possesses little or no deodorizing power, while pure clay is difficult to bring into the proper powdery condition, and has a tendency to absorb too much water. It is not necessary that the earth should be absolutely dry, spread- ing it out in a dry, sunny atmosphere being sufficient. For use it nmst be free from lumps and in a powdery condition. This is best effi^cted by screening it. After being used it may be placed in a barrel, where it will undergo a slight heating and fermentation. It is quite inoffensive so long a* it is kept dry, and it may be stored for any length of time. It is a valuable manure. Ftg. 25.— Sectional view of Hull Ash- closet, inteniled to receive all the dry refuse of the household in addition to the excrement. !; I I I I 98 MANUAL OP HYGIENE. Ilf 237. House-closets on the dry-earth system are very satisfactory if properly made. They are usually constructed with some patent device for throwing the earth down each time the closet is used. One of the principal objects of their inventor, the Rev. Henry Moule, was to find a substitute for the water-closet in d\ filings, factories, schools, etc. With dry earth the soap box or barrel, with a scoop, may be used, as in the case of the ash system, and will answer the purpose in liouseholds composed of adults, but for oliildren and for mixed comnmnitics some one of the automatic earth closets should be employed. The quantity of earth rec^uired is estimated at about a cubic foot per month for each person. The executive difficulties in applying the system are not great, but should be fairly looked at by municipal bodies before introducing it. 238. The Rochdale pail system diflers from the dry ash-pail metliod before described principally in the fact that no absorbents are used. The pails are frequently removed, being fitted with tight covers, and clean pails aie loft in their places. Tlie removal of dry refuse, ashes, etc., forms a part of the system. All the refuse is brought to a depot, where the ashes are spread out on the floor to a certain depth- The contents of the pails are emptied into trenches formed in the aslies, and treated with a small quantity of dilute sulphuric acid; the whole is then tlioroughly mixed, becomes, after a few weeks, quite inodorous, and forms a valuable manure. The removal and subse- quent treatment has, of course, to be carried out by the municipal authorities. Whatever system may be adopted, the old privy-pits should be thoroughly cleaned out and filled with fresh earth. 239. In many country towns and villages there is sufficient garden space to enable the resulting product to be utilized ; wherever this is not the case the removal and disposal should be undertaken by the municipal authorities, and in all cases an efficient system of inspection should be carried out. 240. Making practical application to school premises of what has been said, it ought hardly to 1)0 necessary to comment upon the sim- plicity of the above methods, and the ease with which they may be substituted for the old privy-pits, nor to make any remarks as to their superiority over those filthy and disgusting excavations. The in. MANUAL OF HYGIENE. 99 fluenceof these in the spread of typhoid fever and such diseases is pointed out in other chapters. In any of the above methods slops must on no account be mixed M'lth the contents of the receptacles. 241. Wherever practicable a system of pipe sewers should be devised for the purpose of disposing of these, and should be connected with the house yards by properly arranged sinks and traps. Since the volume of tins concentrated sewage will in general be small, the pipes should be smaller and laid with steeper gradients than those used in connec- tion with the water-carriage system. They should also be provided at intervals with flushing pipes, rising to the street surface, so as to admit of periodical flushing by means of a ho.e to be connected with street watering-carts. Lamp-holes and man-holes, for the proper examination and removal of obstructions, and ventilating shafts should also be constructed at proper points. Any urinals on the premises should be connected with the sewer, and not with the closet. 242. In treating of the water-carriage system in this work it is not intended to deal with all the questions which would need to be con- sidered in connection with a proper system of sewerage. Many such details would only be of interest to the sanitary engineer or to other persons making a special study of the subject. 243. Certain preliminary considerations, therefore, will only be briefly alluded to : — 1. The Area of the locality will have to be estimated by the sani tary engineer in order to provide sufficient sewage accommodation and yet not so much as to impair the flushing operation of surface water by too extensive a distribution. 2. The Rainfall will have to be considered with a similar object in view, anc^ in addition, whether the fall is equal ,le or vaiying. 3. The Geological and Physical characters of the soil have^a bearino on the amount of storm-water to be carried by drains ; and also upon the question of the care that must be exercised in buildinc. them shifting of drains and soakage of sewage being much more liable to occur in porous than in clay soil. 4. The bearing of Water Supply on the flushing and cleansinij of sewers will be apparent. 5. The nature of the present sanitary appliances must be considered t--' ]■ 100 MANUAL OF HYGIENE. H HI Fi^. 20. Pipe defective in contour. 6. The necessity for deciding wliether there are pt-oper facilities /or outfall has already been referred to. Its importance before com- mencing or allowing the construction of sewers cannot be too strongly insisted upon. 244. The materials of wliich drains may be constructed : Tiles answer well up to a diameter of 18 inches. They must be glazed, to prevent soakage. It will be necessary to see that they are not too porous, that they are strong, tough and true-fitting. Their porosity may be tested by weighing them when thoroughly kiln-dried and again when soaked in water, and noting the difference in weight. Their strength is generally tested by putting them under a weighted lever, arranged like the arm which carries the weight of a safety valve, or by dropping weights on to them. They should be true-fitting, for any defect in contour will affect the formation of the joints, and give rise to leakage, as illustrated at a in Fig. 26. Iron pijyes should be made use of when pipes of a larger diameter are required. Their brittleness should be tested as in the case of tiles. If drain pipes are not able to withstand the shock of falling earth or workmen jumping down upon them, ^vithout cracking, they will allow leakage and sewage pollution of the soil. Brick must be the chief material for large drains and sewers. The bricks sliould be very hard and impenetrable, especially for the bottom, to withstand the grinding and polishing action of the passing solid contents. Their porosity and strength may be tested as with tiles. Concrete has been used, but not very extensively nor with much success. And lastly we come to the more primitive material, wood, either in the form of the box-drain, or, less frequently, as fashioned by the cooper's art. The too common practice of using wooden box-drains must be con- demned. They allow sewage to soak out, they soon break down, and they pei'init of deposit and choking, especially when laid on the flat, as they commonly are. For a permanent drain, glazed tile pipes (with impervious joints) should be used ; or, inside of houses, cast-iron pipes, which when hot have* been dipped in pitch. The joints of these should be filled with lead and caulked. These inside drains should, when possi- MANUAL OF HYGIENE. 101 Fig. 57. ble, be left exposed to view. In some cities this object is carried out. even in the horizontal position, by fastening them along the basement walls Any leakage is in this way made visible, and can at once be remedied. This precaution should be observed in regard to all inside plumbing. 245. The shape of drains is a very important consideration, and must vary, according as tlie flow is expected to be equable or vari- able. If the flow IS equable tlie circular form (Fig. 27) is preferable, because it gives the greatest capa- city with the least expense of wall. If it is variable the ovate (Fig. 28) gives the advantage of the deep, narrow stream, when the quantity of fluid is small. So importaut is the sliape of drains, that on it is founded thedivision into thedeposit ^«- ^^ seioers of the olden ti.ne, and s,l/-cleansinff sewers. In old times sewers had to be cleaned out by scavengers, with the same regu- larity as chimney-sweeping. This was due to the fact that the bottoms were broad and flat, and the slow, sluggish stream was not sufficient to carry off- the solid matters which settled as deposits; and deposits once couimenccd increase by their own impeding action. The same plan is still followed with box-drains. In cases where they are put in temporarily to avoid expense, they ought to be set, not flat, as in Fig. 20, but angle down, as in Fig. 30, so as to allow as little surface as possible for accumulation of deposit, and to give the fluid its greatest possible depth and force. 246. The foundation or bed of a drain should be firm and solid, so as not to permit of any breaking or disjointing. If pipes are used,' small excavations should be made to receive the shoulders, so that these shall not have to bear the whole weight of pipe, contents and superincumbent earth, with no support to the rest of the pipe, which is then liable to break or crack. Provision should be made for carrying away sub- soil water, which is liable to make for the new earth formed in di-ging the bed of the drain. If the drain He i« a porous stratum and otr.r Fisr. 29. Fiif. 30. ri h !l 102 MANUAL OF HYGIENE. ii i| ! an imponotrablo one, the chances of the water running along its course will be especially great. Some tiles are made with a subsoil space, porous or perforated so as to carry off this water. 247. Joints should be true-fitting, so as to prevent gaps, out of which the cement or clay may fall or be forced. Care should also be taken to prevent the apposed ends from losing their concentricity when laid : if tlie joints be fitted with puddling clay or other soft material, this will give way under the downward pressure of the small end of the pipe, until this latter rests directly on the receiving collar of the next pipe, leaving no space between them on the under wall, but a large gap on the upper (Fig. 31). This will be especially the case if no spaces have been cut to receive the shoulJors. To prevent it the joints should be stuffed with oakum, and then with puddling clay or cement, or if the pipes be of iron, with lead. This will also prevent the intrusion of rootlets of trees, which are apt to ir.sinuate themselves and cause accumulation and choking. Some persons try to kill rootlets by mixing bichloride of mercury in the cement. This is a poor expedient at best. 248. The junctions of drains, whether they are in a vertical or hori- zontal plane, should not be at right angles (Fig. 32), as the interrup- tion of the stream and the eddies thus formed will cause deposit, which, when once commenced, will rapidly increase. The tributary stream sliould be made to enter in a course somewhat parallel to that in the main sewer (Fig. 33). Fig. 31. Fig. 32.— Improper Junction. Fig. 33.— Proper Junction. 249. The slope or fall req lisite for good drainage will depend on various circumstances : the natt:re of the matters to be carried off, the volume of fluid, the equableness of flow, the facilities for flushing, and the smoothness of the drain. Solid matters being more likely to lod'^e MANUAL OF HYGIENE. 103 in a shallow than in a full stream, it will be evident that they will be still more apt to lodge if that shallow stream run slowly than if it run rapidly. It is a mistake (and one commonly made) to build drains larger than is necessary for the volume of water to be carried off. A 9 in. drain is often used for a house for which a 6 in. would be ample and would give a better flush. 250. Various experiments have been tried as to the carrying force of sewer streams. According to Latham a velocity of about 180 feet per minute, when running half full, is necessary for efficient house drains. He states that this would necessitate : In a 4-inch drain, a fall of 1 in 92, and would take 7-85 cubic feet per minute ; in a 6-in'ch drain, a fall of 1 in 137, and would take 17 66 cubic feet; and in a 9-inch drain, a fall of 1 in 206, and would take 39-76 cubic feet. It must be borne in mind that the above calculations as to the necessary slope are based on the presumption of the drain running half full ; but such large quantities of water as those indicated above are not generally poured in at once. The main house drain is rarely filled half full, for it is the larger common outlet of a number of smaller drains, and unless these are running simultaneously it will not be half full. Hence the greater necessity for providing means of flushing house drains by causing a body of water to rush swiftly through them, thereby washing out any deposit that may have accu- mulated. 251. For flushing house drains our first care should be to see that there is provision for nearly filling them, either by the simultaneous action of a number of small inlets, or by one large one. In houses where there is a closet pipe it is generally of nearly half the sectional area of the drain from the house to the street, and by filling it with a good head of water the latter drain will be nearly filled. Many con- trivances, differing according to circumstances, will readily suggest themselves for supplying a body of water. The most primitive will be the sudden emptying of a tub of water every day or so. 252. What is called the separate system of sewerage has been intro- duced into some cities in order the better to attain the complete and speedy removal of sewage. The name of Colonel George Waring, Jr., is intimately associated with this system. The peculiarity of it is that small, glazed-tile sewers are used, only large enough to carry the i 'V 104 MANUAL OF HYGIENE. sewage, and not allowing of the entrance of stoma water. Through these small sewers, with their glazed surfaces, there is a more rapid and complete discharge. We now proceed to consider the means for the proper dilution and discharge of sower gases. 253. Traps (See Sec. 226) are of two kinds— " Dry-traps " and "Wet-traps," or "Water-traps." A dry trap is a mechanical con- trivance by which some solid body acts like a valve, closing a drain or pipe against the passage backwards of any gaseous or liquid material. A form of dry-trap is here shown : the valve, as seen in fig. 34, has been opened by the flow of sewage, and will close as soon as the flow ceases, as i . fig. 35. Fig. 34,— Palmer's Trap with the va!»e open. Fig. 35.— Pahiicr'sTrap with the valve closed. 254. Dry-traps are very liable to allow of regurgitation of sewer gas whilst the sewage is flowing, and also to get so out of order as not to close the drain against a constant reflux. They are, therefore, not so good as water traps piopcrly vented, with frequent change of water and ventilated drains. They should only be used where these condi- tions cannot be obtained. 255. A wet or water-trap (Figs. 36 and 39) is a contrivance holding, in the course of a drain, a body of water which entirely fills a shoi-t section of it, and separates the air below this section from the air above it, the through current of air being completely stopped. No fir can pass through the trap except under such pressure as will force MANUAL OF HYOIENE. 105 the water in it. In some wet traps mercury seals are used to prevent evaporation. Fi(f. 36.— Various forms of Trivps. The addition of the dry principle which is mado to some weUraps is, to say the least, useless; it is apt to fail, and tends to accumulate filth. Inside a house no drain should be allowed to exist unless there are proper facilities for a sufficient water-trap vented and furnished with frequent change of water. (See Sees. 257-26i.) There, are, however, certain situations out of doors where a water-trap is apt to become dry, and where a combined trap may answer a useful purpose. 256. Guerin's gully trap (Fig. 38), invented by Mr. Thomas Gucrin, ■••■• H -J Fig. 87.— Street gully, with Ouerin's trap in position. ;.. j Fiff. 38. KnlargLil view of the trap sluiwti in Fif. 37. C.E., of Ottawa, is one of these. This contrivance A, V, is attached to the head of the outlet pipe of the street gully or catch basin (Pig. 37), which receives the gutter water at 0. ^s the water accumu- lates in the gully, the plu- V rises and allows it to How oli' throu<^h Hi J i Pi i 106 MANUAL or 1/yOlENB. 'f tho water in the gully m»'*poratea or leaks conical opening and provonta the the outlet pip^ip /), away, then V drop, ir to the passage outward of sowor gas. 257. Where there are traps they are liable to be forced. A trap without a vent is of hardly any practical value. A trap with a pro- tecting depth of svator (coinniouly called the "seal") of three inches, (a three inch seal), only resists a pressure of some two ounces to the square inch. Any person can readily convince himself of the insuffi- ciency of a water-trap without a vent by tilling such an one and blowing through it. Without any great exertion ho can displace the water and force his breath througli the trap. If he now make a vent between his mouth and tlio water he cannot displace the latter, no matter how hard he blows. The influences, which have been fully considered in Sec. 424, have a powerful action in forcing gas back thrc h traps. i 2&b. Again, traps being emptied by syphoning, sewer-gas may be ndmi* 'ed. If to the end jf a trap a tube bent downward be added, it forms tho long log of a syphon, the portion of the trap to which it is added being the short leg ; if a full stream be poured tlirough the trap, the water will syphon out of it, leaving the seal broken, as may be proved by experiment. An opening or vent at the arch of the syphon (see V, V, Fig. 39) will prevent this. 259. The water may be sucked out of a trap by a large body of water rushing down a pipe into which a trapped tube empties. This, again, will be preveiited by a vent pipe. 260. Disuse of a trap for a long time will allow evaporation and emptying of the trap and free passage backward of gas. Care must be exercised to see that traps do not leak, and that they are kept well supplied with water. Persons entering a house in which the various services have been long unused should at once turn water into them and open the windows. 261. By absorption Ihrough the contents of traps gas is often taken up and given off. r)i ^^ergus, of Glasgow, found that ammonia is transmitted through un , '- i.m- tcap in about twenty minutes. It is more volatile than other s ■ ;-i gas.-j.-, and fortunately less injurious. This transmission mav ?« , 'vi.ted by hf.i'.,K?, in addition to the extension of the soil pipe thioui, the roof (tig. 39, A), a second main vent foul E S K r ft MANUAL OF HYQIENE. 107 A trap s ventilating tube, B, and those two will form a circuLuion. preventing toul air from accumulating— staguaut— at tho traps. 262. In a system of lo" ■ house-drainage, the tube just i(>tcrrecl to mny bo securt'il by ruiiniii*,' a 4 inch pipe (Ji) tVoni tho sewer, just outside tho house wall, uj) to tho roof, clear of cornices, chinintiys und windows ; wliilst tlie counter open- ing,' is obtained by con- tinuiii^i,'the soil-pipe (A) u}) through the roof. A diflerenco of tempera- ture in the pipes will cause the air to cii'culato through then). In win- ter A will generiilly !«« warmer than Ji, and the current will be down IJ and up A. In summer, with the hot sun shining Fig. 39.-SeoUon showing an efficient system of liouse drainage and viraln ventilation. ! 108 MANUAL OF HYGIENE. upon n, the current may be reversed ; provided that both pipes run' to the roof, this will make no difference ; there will in either case be a through circulation of air, and as the two pipes will seldom be of the same temperature, this circulation will nearly always take place. It will be evident that the practice of some architects in leaving the pipe B cut off short under windows is not in all cases to be recom- mended. The current will generally be down the short outside pipe, but it may happen to be the other way, as for example, if the short pipe is on the south side of a wall, and the hot summer sun is pro- ducing an ascending current up the wall. Again, when a discharge of water or sev/age takes place down A, the gas will always be forced up^. The pipe {A) will save the traps opening into it from being forced by gas from the sewer and drain. The traps of the baths and lower closet — all traps, in fact, below the uppeiniost one— must be saved by their own vents ( V, V, V,) from being syphoned or from having the water sucked out of them by sudden liberations of water above. These vents may open into the extended soil-pipe above the highest trap. In the diagram, pipes {K, K,) will also be seen rising from a point below the hopper of tlie closet, a little above the water in the trap. These pipes may serve a double purpose. By branches from the water-closet tanks tliey may act as flushers to the closet traps, and they may also carry off tlu; air from above the closets. They may lead to the outer air or to the chimney-flue of an isolated kitchen in constant use, but never into a bedroom chimney or any other not used comtantly in the strictest sense of the word. And never should any tubes which have connrction with a drain or soil-pipe open into the chimney of a dwellimj-liouse. The trap shown between the house wr'l and the street sewer might be left out if we had a perfect system of sewerage— one fulfillincr all the requisites summed up in Sec. 215; and if the plan we have just indicated were to become generally adopted (as it should be, by by-law, and as it is, theoretically, in every municipality in Ontario, unless where some other by-law has been substituted for that appended to the Act of 1884). The drain would then be carried directly to the sewer, as shown by the dotted lines. But in the present condition of most of our sewer and drainage systems we have to fear that gases of MANUAL OF HYGIENE. 109 decomposition and germs of disease exist in many portions of our sewers, and that the inside plumbing may not be perfectly sound and tight. Hence, the best plan is to leave the trap in the position shown, and to have a third V(>ntilating pipe (C) running up to the roof from a point just outside of the trap and between it and the sewer. We should thus lessen the possibility of even dilnted sewer-gas finding Its way into apartments through corroded pipes or defective plumbing, whilst at the same time overhead ventilation of sewers would be secured.* In no case should weoping-drains, wastes from refrigerators or other Uke appliances have direct connection with the drains or drainage- pipes of the house : their traps are too insecure. (See Sees. 260, etc ) 263. Plans of drainage should be carefully preserved, e.y., by keep- ing them with the title deeds. Any alterations sliould be noted on them. Much trouble, uncertainty and expense would thus be saved • mischief IS frequently caused l.y unused and forgotten drains; and material often has to be torn „p to search for drah.s, pipes, traps, etc. 264. It may be well to utter a warning against the pan-closet a very common form, of which a diagram is here shown. Th(< passage from the bowl into tl... "reeeivor" is closed by the pan, holdin- water and preventing tlu3 constant passage backward of gius when the closet is not in use. But when the hn ndle is drawn up the pan is deflected downwards so as to discharge its contents into the receiver, as shown in the diji- gram ; and, as two bodies can not occupy the same space at the same time, there is forced up from the receiver the gas rendered doubly foul by the repeated coatings of faecal mat- ter adhering to its wall as it is thrown on to it from the pan. SEAT- Iron Keciever FLOOR^S! LtAD TRAP Fig. 40.— A bad form of eloset in very common usn, the "pan -closet." • A full discussion on "Overhnad V,.nti!flt.ion" may be seen in Vol. IX of the "TransactionH Of tho American Public Health Association," pp. 233-7 and 396.4U. and a synopsis of It In Z hecond Annu«l Re^)ort of tho Pryviucial Board of Health, pp. 188-192. m 1 it ii ! i 5 lilii i • I i 110 MANUAL OF HYGIENE. 265. There are many patent closets whose claims have been vaunted but none should be used which violates any of the following requisites of a good closet : — 1. That there shaU be no opportunity for the lodgment of filth on or in any p;u't of the closet. 2. That there shall be no space between the bowl and trap for the accumulation of filthy slime. 3. No confined space for the accumulation of gases, as in the pan- closet, and others in which there is an air space between the valve or seal of the closet and a trap below. 4. That there should never be, even momentarily, an open commu- nication for the passage into the apartment of gas from the soil-pipe, or from a (■(iiifiiiod air-.spaco. 266. The simple hopper with a good swirl of water to keep its walls washed clean whilst in use, and with an occasional fiiish from a flush-pipe (See Fig. 41), will meet every sanitary requirement and will be free from the objections to which many forms of patt^nt closet are open. In fact it is the best and most simple form of clos(>t. It has a conical earthenware bowl, the walls of which ai-e completely washed and kept wet when the closet is in use, by a swiil of water from a pipe opening at the upper part of the bowl at an acute angle with its wall; the pressure on the hinged 2 seat is connnunicated through a rod Fig. 41. -A form of do -t recommended. to a v:i]v(" it) tliis pipe. Beneath the closet-bowl is the I! :!i MANUAL OF HYGIENE. Ill trap, the spaco between tlio lower end of the bowl and the surface of the water being not more tlian three inches, leaving the shortest pos- sible space for slime to accuimdate, and leaving both this s.,ace and the trap readily accessible to the hand, should scrubbing brushes tumblers, etc., be thrown down. Into this little space a l-|-inch flush' pipe opens, which is an addition for greater sanitary precaution. This flush IS wf.rked by a cord conununicating witli a lever and plu- in the tank above. If the tank is not directly overhead a piece of bath chain and pulleys may be employed. No space should be left between tJie seat and the top of the hopper of watei- closets, througli which nrnie or other water may slop over. A foul odor often ''proceeds from negh ,'t of this precaution. 267. Closet pipes should be supplied from a separate tank, and neve.' from the general system of water supj.ly. (See Sec. 221).) Contamination by interchange of contents through leaky pipes carrying respectively water and sewage are on record, and great care should be taken to guard against such an occurrence. 268. That out-door closets in connection with the water-carriage system may be euiploycd in this country is no longer a luatter of doubt. In the cas<^ of careful individuals a modification of the above closet. with ti'ap deep in tlu ,'i'ound, may be so used. But when (Coinjriyhl ISSB. by the J. L. Holt Inn WurUJ Fig. 42.-MoU'8 Latrine. Ijit I I '; 112 MANUAL OF HYGIENE. numbers of persons of various classes liave to use closets, they cannot be relied upon for care and cleanliness. 269. Latrines should therefore be used to supersede the privy-pit in the densely populated districts in which the water-carriage system is established, unless it is resolved to use the dry system under cor- poration management. In many places the change fiom the old system to the new is being gradually made. No new pits are allowed to be dug ; and when any existing one becomes a cause of complaint, it is ordered to be cleaned and disinfected, and filled with fresh earth. These latrines can be controlled by some servant of the corporation, or other person, who shall, from time to time, change their contents, and supply tliem with water. Of the various forms of latrines, the following may be mentioned : — 270. So-called ''iron sinks" are manufactured in various cities ou this Continent, and are being largely introduced. One of them is shown in Fig. 42. The hopper or receptacle, and its corresponding section of drain, are made in one piece, and the several portions of drain are then connected. The contents are run off periodi- cally by raising a plug at one end of the drain, and the drain and latrines are refilled. When these are situated out- doors slight artificial heat must be used in winter. These latrines are very moderate in price. 271. The Liverpool trough closet " may be described as consisting of a series of closets connnunicating with a long trough (T), situated beneath and behind the seat (C), which receives the ex- Fig. 48.— Uverpool Trouifh Closet. crota from each closet in the series. The lower end of the MANUAL OF HYGTKNE. 113 trough communicates with a drain (Z>), leading to the sewer by an opening {K) which is closed by a plug (P). Behind the huck wall of the closet there is a small space {X) to which no one has access but the scavenger," and in which are the plug and a hose connected with a hydrant. They are cleansed and filled as described in the preceding section. 272. The Bristol eject "consists of a strongly constructed dip-trap, interposed between the privy-trunk, as the receptacle is termed, and the drain. It thus admits of the ready exti'action of foreign matters which may I)e thrown in." 273. An advantage of latrines in the event of an epidemic of cholera or enteric fever is louted out in Wilson's " Hand book of Hygiene," namely, " it will bo an easy matter to throw disinfectants into the troughs, and thus destroy the infectious power of the alvine dis- charges." 274. If a moderate artificial heat were introduced with the use of such latrines a double gain would have been secured. The exposure to severe cold is sometimes very injurious. Xot to enter deeply into the subject, let us take the case of a school-child just recovered from scarlet fever, the jx-eliug of the skin having been accomplished : exposure of the skin to severe cold may produce fatal disease of the kidneys. 275. If, however, these conveniences cannot be heated, we must place the water appliances deeply, as is done now with our water- pipes, hydrant-services and drains, always remembering that the open troughs are more exposed to atmospheric changes of tempera- ture. In this Province out-door latrines and closets without heat have been introduced, and, when carefully constructed, have been found to work satisfactorily in the winter season; but great care needs to be exercised. Souie places, such as factories on the course of our larger rivers may be so favorably situated as to allow of troughs with a continuous stream ; but extreme vigilance, as regards outfall, must be exercised in connection with this practice. jSTunierous cases of drinking water being polluted by sewage have come under the notice of this and other Boards. 276. Urinals become offensive through want of proper provision for i ii 114 MANUAL OF HYGIENE. preventing the incrustation of tliem with deposits from the urine, and of proper means of frequently cleansing or removing sui-faces in their neighborhood. A tray of ashes or sawdust in front of, and beneath, the urinal will meet this latter requirement, the contents of the tray being frequently changed. For the first mentioned cause of oflensive- ness it seems necessary to have a flow of water washing the urinal whilst in use. Disinfectant contrivances are also used. 277. Intercepting sewers and intercepting tanks are employed in many places where the natural facilities for outfall are not good. A form of intercepting sewer is shown in Fig. 44. It passes under the sewer (C) near the outlet of +he latter. When the stream in the latter sewer is small, and the sewage concentrated, it drops throu<»h the opening between B and D into tlie trough of the intorceptiii" sewer. During a heavy rain, or the operation of Hushing, the first and concentrated part falls into the intercepting sewer ; but as the volume increases, the velocity also increases, and the stream shoots over the opening, as shown by the stream A. The con- tents of the intercepting sewer are carried off to be disposed of as indicated here- after. 278. Of the pneumatic systems it may be said in brief that they aim at the removal of sewage by draw- ing it through pipes to cen- tral reservoirs or tanks, in which a partial vacuum is created. They are not re- c-^;h: ceived with favor by sani- tarians in general. The Lier- Fig. 44.-AI1 intercepting sower. ^-Ui') Berlier and Shone are the three principal systems. IV. 279. The ultimate disposal of sewage when it has reached the outlet of the sewer system presents many difficulties. It may be allowed to flow into large bodies of water, such as our inland lakes, or into MANUAL OF HYGIENE. 116 large streams the water of which is not used for drinking purposes, and in which it is so diluted as to be comparatively harmless. Thei'o are, however, many objections to the latter method of disposal. Jf, from situation neither of those methods is practicable, it should be disposed of in some of the following ways : — 280. Precipitation is the term applied to the processes in whi.>h tlie contents of sewers are received into tanks, the solid portions allowed to settle and the liquid to ilow off. The settling or "pre cipitation" is generally aided by the addition of chemicals. The solid settlings are removed and used for maimre. They are generally dried, and handled either in the form of powder (poic- drette) or of "bricks." In these forms it is inoffensive, but as much cannot be said for the various drying processes by which it is manu- factured. Lately, however, a method has been invented by which the solid matter is treated by hydraulic pressure, the nuisance arising from the drying process being obviated in this way. The substances which have been used for precipitation of sewage are very numerous ; and so, too, are the various combinations of them which have been adopted under various names, such as the A. B. C. process, Lenk's process, Suvern's process, the Lime process, the Super- phosphate process, etc. We will merely mention some of the principal substances themselves : lime, alum, iron sulphate, iron chloride, zinc sulphate, sulphuric acid, clay, magnesia, permanganate of potash, ashes, tar, charcoal, etc. With the use of some of these chemicals the liquid is so purified as to need no further treatment. 281. Intermittent downward filtration is the term applied to the method which has been adopted in some places where it has been found impracticable to use the li(piid as manui-e, and where i( .las not been rendered pure by chemical precipitation. A small quantity of waste land is under-drairicd at a depth oi from four to six feet, and the sewage flcnvs over it. By the action of the air contained in the soil, and of the roots of vegetation, it is purified, and then flows throuf^h the sub-soil drains into the nearesc watercourse. The same process is repeated on another portion of the land, and then oii another ; and by the time the whole surface has been treated in this manner the first portion is ready again to receive the sewage, the soil havin" had time to dry and re-absorb air. ! I i\ I , r i* 116 MANUAL OF HYGIENE. I ,, 282. Irrigation is a method by which liquid sewage is applied directly fts manure, the fields being irrigated with it, eitlier by means of surface trenches or opon-jointed drain-tile pipes, laid about a foot below the surface. The soil should be under-drained, and the sewage should be applied on the intermittent principle explained above. Sewage farms have been worked for a good many years in England and on the Continent of Europe; and although at first they were looked upon in many instances as public nuisances, yet of late years, with increasing experience and resulting improved methods, they have been gradually growing in public favor. It seems to be the general testimony of medical men, chemists and others, that, when properly managed, they are in no wise injurious to the health of the people in the neighborhood, and that the produce of such farms, both animal and vegetable, is as wholesome as that of any other. On a sewage farm there should be at least three sets of fields, viz. : one for summer irrigation, a second for winter irrigation, and a third for what may be called storm-water and residual irrigation. The fields for summer irrigation are treated regularly with the sewage during the growing period of the crop. When the harvesting of the crop or other circumstances render it necessary to stop the irrigation on the fields, it is directed onto the residual irrigation fields. This is also done during storms or floods, in cases where the storm-water passes through the sewers. The fields for residual irrigation are best kept in grass, and may be used for pasture. 283. During the winter the sewage is directed on to another set of fields. These are ploughed in the spring and cultivated during the ensuing season without any further addition of sewage, that received during the winter generally proving suiEcient. 284. The experience of Dantzic, and of the State Insane Asylum, Augusta, Maine, have tested the practicability of this method of sewage disposal in winter. " The sewage flows out under tlie snow through the many furrows prepared for it, leaving a thick crust to be ploughed into the land in the spring. . . . When the mercury stood at nearly 0°Fahr., and the ground was frozen hard, the sewage was found to disappear very soon after it was put on tlie land. In the spring the early rains wash any refuse that there may happen to be MANUAL OF HYGIENE. IT? deep into the soil, and no offensive odors are noticed. The surface of the ground is tlien sometimes found covered mth a brownish scum." These experiments are of great value as solving a question which naturally arises in connection with the climate of this country. As a general rule systems of sewage disposal are not made to pay their own expenses by direct money returns. The aim is rather to minimize the expenses entailed by such disposal as shall lessen the amount of death and disease occurring amongst us. In connection with Pulman, 111., however, there is a sewage farm, the crops from which are said to yield a good i-ate of interest on the money invested. 285. Over and over again the death rate has been materially reduced by the introduction of improved methods of disposal of excremental products, showing that many deaths are annually caused by the filthy methods at present in existence. The young are most susceptible to the baneful influences of these methods ; and as this work is especially designed for the use of teachers in our schools, we would in this matter, as well as in the ventilation of schools, ask them to use their influence to bring about better conditions ; to use whatever discretion- ary power is left to them, and also to agitate, not only with school trustees, but with citizens at large, the adoption of hygienic methods. 286. Especially let our men remember that there are in attendance at schools, both as teachers and scholars, those who, from motives of delicacy, will not refer to this subject themselves, and whose delicate organization leaves them the more susceptible to the evil influences of the unsheltered and filthy places to which they must sometimes resort. This remark will apply also to those of the other sex who are engaged in business houses and other public places. Shall it be said that men who strive to show their thoughtful politeness in other matters, some- times in mere formalities of etiquette, shall, in connection with this matter, allow those who cannot speak for themselves to be subjected to such injurious and disgusting treatment i ,1 s CHAPTER X. INFECTION AND CONTAfllON— NATURE OP INI'KCTIOUS DISEASES— MODES OF PROPAGATION — MEASUUES OF PliEVENTION. 287. The terms contagion and infection aie used to denote the pro- pagation of disease fn,m one individual to anotlier; and also the matter by which the propagation is eHected. We have perfect knowledge that tliis propagation is sometimes efiected by inocula- tion; and from analogy and from oui- inability otherwise to explain the phenomenon, we infer that in all cases of contagion there is a communication of such matter. 288. Contagious diseases may be divided into tliose whereof the contagious matter acts only by positiv.. contact between the individuals communicating and receiving the dis.^ase, or by its transference in a visible form from one person to another by inoculation, and those which, are also capable of transmission from individual to individual through the medium of the atmosphere. Contagion is, therefore, immediate or mediate, contactual or remote. To the former divisioii are to be referred itch, ring-worm, Egyptian ophthalmia, some varie- ties of skin and other diseases ; to the lattcn-, small-pox, chicken-pox, measles, scarlet fever, diphtheria, whooping cough, typhus fever' typhoid fever, lirjspital gangrene, puerperal fever, etc By some the term contagious is limited to the first class mentioned, but the distinction is not general amongst writers on the subject. 289. Diseases are said to be epidemic when they attack a large number of individuals simultaneously. They are said to be endemic when, as is the case with malarial diseases, they are limited to a certain territorial district, and exist there either continuously or for an indefinitely long time. 290. As far back as history goes we find records of devastatincr scourges. They liave destroyed, remark.s Liobrrmeister, the armies of conquerors, liave been the means of removing whole races of man- MANUAL OF HYGIENE. 119 kind from tlie earth, and liavo given death-blows to advaiieod civiliza- tion. In the fourt(?entii century the most deadly of all tiici pestileiuios recorded in history, the Black Death, changed the direction of intel- lectual and social activity throughout the chief part of the civilized world. Throughout Kurope more than a million of lives tVIl a prey to this scourge. Italy lost one-half of her iidiahitunts ; and in England, if cotemporary statements were not overdrawn, scarcely one-tenth of the iuhal)itants were left. 291. Among the causes that have lessened epidemics are advance of civilization, the improved sanitary conditions under which we live, and our increasing knowledge of the nature of epidemic diseases and the way in which they are propagated. 292. The modern hypothesis of infectious diseases is that of a contor gium vivuni, viz., that the poison of infectious diseases consists of living organisms. This idea, however, has not the merit of absolute novelty claimed for it. The Roman authors of Ih Re Jiustlcd, Varro and Columella, refer the oiigin of many malarial fevers to the entrance of a low order of organisms into the body. Within the last few years investigations of the ai)pearance, mode of propagation, and nature of these organisms, new facts in I'egard to the extension of infectious diseases, and a number of positive discoveries have furnished definite proof of the correctness of the "germ theory" of these diseases. To discover the contagium of the v.accine disease the microscope was used and Dr. Lionel Beale, in December, 1 803, announced the discovery of transparent vesicles of extreme minuteness in vaccine lymph, and ex- pressed his conviction that the contagious or active propeities of the lymph lay in these particles. The correctness of these observations, now admitted as being without doubt, was subsequently verified by other scientific men. The germs of various contagious diseases have been isolated and cultivated in broths and other "culture fluids " in which they have multiplied rapidly ; the germs resulting from these cultivations have been found to produce in animals results similar to those observed in the animals from which the parent germs were taken. In some instances, the diseases so produced have been less severe, and have been found to act as protectives against the more severe forms. The labors of Pasteur in this direction bid fair to prove a boon to mankind in the mitigation of hydrophobia; they 120 MANUAL OF HYGIENE. havealroarly lassenod t!i« mortality from charbon and chicken cholera among the lower animals. Quito roeently, Dr. Ferrau has been en- • loavoring to obtain similar n'sults with the yorms of Asiatic cholt!ra, with what success we have not yet suiUcient evidence to enable us to determine. 293. The characteristic quality of a contagium vivum, or virus of a .•omnninioal.le disease, is its capability .,f un.lergoing almost unlimited nmltiplication when introduced into an appropriate niodium. This power of development and this faculty of breeding true, were the first, and have ever been regarded as the chief, arguments in favor of the germ theory of disease ; and it is difficult, remarks Dr. Maclagan, to see how these properties of contagion can be accounted for on "any other view of its nature. 294. Each virus has a definite and specific action, although the symptoms may vary with the dose of the substance introduced. The etlects may be modiiied by temperament or constitutional peculiarity on the part of the recipient, and after a time the substance may be ilirainated from the system. It may [now be concluded beyond dispute that infectious diseases are induced in the system by a morbific agent which is propagated in, and given off by, the bodies of the sick, and is capable, when received into a susceptible, healthy body, of producing in that body a disease similar to the one during whose course it was formed. 295. Therefore every infected person becomes a breeding place of disease. An examination into the natural history of these infecting particles, or contagia, demonstrates them to be organized structures- living entities —called (jerms, micrn-orf/anisms, microbes, micro-zymes, etc., and divided up into bacilli, bacteria, vibrios, etc., according to differences in their forms and other peculiarities. Like all living things, they are endowed with properties designed for their propagj^ tion and continuance. Each disease has one or more channels by which its special contagion is eliminated. 296. In giving a brief description of infectious diseases we will only refer to those diseases, and those features of them, which may be of general interest or use. The disturbance of the system occasioned by them is sometimes so slight that they are overlooked. It is therefore desirable that teachers, railway officials and others should have such MANUAL OF HYOIENE. 121 knowlerlge as may draw their attention to cases of this kind, in ord.^r that proper steps n.ay bo taken, the advice of a piiysician being obtained when necessary. 297. There are certain premonitory symptoms in most of those diseases', sucl, as lassit.ule, h.-adache, heaviness, diminution of appe- tite, tluist and slight heat of skin altcsmated with chilliness. Of course, an attack may occur without all of these symptoms being present. Tiiere are also differences as to their prominence in the different affections, and even in the same allei'tion in different individuals; still more marked are the differences in tlxur duration. 298. In measles they are generally present for soru ^ days. They are followed by a watery condition of the eyes and nose, sneezing, sometimes cough and hoarseness. About the fourth or fifth day small, circular red spots, slightly raised, appear on the face, and spread to the body. These gradually run into half-muon shape.! patches, with skin of the natural color between them. About the seventh day the rash begins to fade from the entire body, and lessens in brightness during the succeeding days, or gradually disappears by desquamation, accompanied by much itching. Occasionally a nudig- nant form, with very dark-colored spots, is seen, to which the nam^e of "black measles" is popularly given. 299. In scarlet fever the premonitory symptoms are often of much shorter duration, the rash appearing suddenly. It consists of red spots, brighter, more minute and more thickly sprinkled over the skin than in measles, which soon unite into a continuous scarlet rash with no intervening skin of natural color. It is usuallv accompanied by sore throat, swelling and tenderness of the neck and enlargement of its glands. The disease varies very much in severity ; sometimes it is so malignant that the eruption is mattery, and the throat is very badly ulcerated. Other cases are so mild as to be overlooked altogether or till some of the after-effects (or sequehe) cause enquiry to be made and the previous existence of a slight rash or redness to be remembered These are the cases which are most likely to call for the watchful scrutiny of the teacher. It is worthy of remark that the after-effects are not by any means to be measured by the mildness of the attack TJie rash subsides u.sually between the fifth and seventh day, and is followed by the desquamation or peeling of the skin, which comes off i i I ? n H 122 MANUAL OF HYGIENE. i IM ill. ill in flakes more porcoptil.le to the eye tl.an those of measles. This lasts .several weeks. 300. Rothein, or "Gerniau measles," partakes of some of the charac- teristics both of measles and scarlet fever. It is more apt to recur than either of these diseases. 301. In diphtheria, too, the onset is generally more sudden. The characteristic sign is tlie deposit of yellowish patches on the tonsils palate, back of the throat or nasal passages, or, in the more se^•ere cases, in the windpipe and bronchial tubes. There is frequently swelling of the face and of the glands and other tissues of the neck ; also a discharge from the nose and eyes, often of a more yellowish' color than in measles. Sometimes these latter discharges are p.'esent before true diphtlieritic patches have appeared in the throat. In mumps (inflammation of the parotid gland) there is stiffness and paniful swelling about the articulations of the jaws, without sores in, or discharge from, the throat or nose. 302. Whooping cough generally commences like a common cold, with watery eyes, sneezing and a dry cough. After a time th,. cu-di becomes spasmodic, consisting of a long expiration, broken by"a number of short, jerky coughs, the walls of the chest and the dia- phragm being spasmodically cmjiressed to the utmost degree, expellin■ vh moisture. 357. As a protection a.' Vt cold winds, fur, leather and Id-' a rubber take the first rank, wool second, cotton and linen about equal. Owing to the condensation and retention of perspiration, the Council of Health of the French Army has persistently refused to allow the introduction of waterproof garments. This objection can only be con- sidered valid Avhen waterproof clothing is persistently worn. 358. Clothing should be evenly distributed over the surface of the body, so as to equalize the circulation. An extra flannel around the abdomen is sometimes an advantage. The exposure of the arms, legs, thighs and upper part of the chest in young children is very' b^d' especially in cold weather, or in the chilly evenings of summer time! The same remark holds good of the custom of ladies in cutting away their garments at the upper part of the chest : this is not only e^xposed in evening dress, but it has rarely jnore than the thin covering of the outside dress at any time, whilst innnediately below are many thick- nesses. Kail dresses, combined with the overheating of the dance and the subsequent chilling, are notoriously bad Thin-soled boots err in the same way, by allowing the soles of the feet to be cold. They are also liable to permit too much moisture to reach the feet. Teachers and others should see that children do not sit in damp clothing. 359. The night-clothing of young children should be so made n.s to secure a warm covering to the whole body under all circumstances. Night coverings to the feet, however, sometimes tend to make them i < I -I i u i , J I: it 140 MANUAL OF HYGIENE. throw off the clothing. The combined waist and drawers answer well 360. The shape, size and pattern of clothing are of the utmost importance : the movements of the chest, abdomen and limbs should not be restrained by tight clothing, hence tight waistcoats, corsets, stays, coats and trousers are highly objectionable. Tight-lacing, as practised too frequently l)y girls, until the waist loolcs like an hour-glass, and as easy to snap as ji pipe-stem, results in dangerous coiupies«ion of all the vital organs (Fig. 4')), and must, if perse- Flg. 44.— Positions of viscera In the natural waist, Fig. 45.— Positions of viscera in a waist deformed by tight-lacing. vered in, end in disease and deformity. Tightness of any article of dress is particularly to be guarded against in children, in whom the bones are soft and easily bent out of their proper shape. Garters are apt to induce varicose veins, and also , (loil the shape of the leg. -_^!, ^,„,„!ng snQ''t{| not B8 nfiSVy. tt amith should be obtained, not by adding great weight, but rather by thicknesses of loose material MANUAL OP HYGIENE. 141 wbch wm hold layers of air, as for example, thick, loose woollens, and such materials ss eider-down. This latter is especially suitable for mght-coverings, to which the above remarks apply with great force. Great weight, even of bed-clothes, is very tiring, especially to young children. = r J ^ 362. The weight of clothes should not press unduly on parts which may be injured by such pressure. For example, the dragging of a woman s skirts upon her waist may give rise to disease of the abdominal organs. In male attire, the belting on of the trousers is also injurious. 363. Head COVering.-Tight-fitting silk or beaver hats, made of substances which are non-conductors of heat, retain the heated air in contact with the head, and by compression frequently give rise to headaches Frontal headaches and neuralgia in women are largely attributable to the want of covering for the forehead. ' 364. The neck should be either bare or with only a loose-fitting collar. A tight-fitting collar prevents the free circulation of the blood m Its passage from and to the head. The liability to take cold is also increased, if at times the cc.ering is dispensed with. In chUdren ^""17^ 'ir^^ ^""^ **^"P '^*'^*^^''' ^^^ "^^^ ^^^«"^d be left exposed ' 365. The effects on the head and neck of the direct rays of the sun m very hot weather may in a great measure be prevented by the use of a suitable covering. A wet cloth folded and placed in the crown of the cap, and a similar wet cloth to the nape of the neck, will prove an excellent protection. 366. Boots and shoes, instead of allowing the same freedom tc the toes as to the fingers, often cramp them together, and render them of little more value than if they were all in one ; the joints become stifiened, enlarged and distorted, the toes oit'^n overlapping each other, to the extent of ren- dering them unfit for service (Figs. 46 and 47) 367. The proper shape of the foot (Fig. 48) we shall find in the new-bom; we shall also find it in persons accustomed to walk bare- foot, and m families that have always been Rccnstn,iu.d fo h— their children supplied with shoes of a correct form. In examining the impf-ess of a well-sh-.ped naked foot in the sand we shall find thn Fig. ■!«.— Distorted foot : dorsal surface. I -i 148 MANUAL OP HYGIENE. Fig. 47.— Distorted foot : plantar Burfaue. Fig. 48. — Natural shape of tlie foot. following marks: Behind we have the regularly rounded heel; in front the oblique impression of the soles of the toes. Between the sole of the great toe and heel the foot is elevated, and no impression is made. The form of the sole, then, is that of an arch, with the extremities enlarged ; in front of the arch are the five oval impressions of the toes. In comparing the impress of the natural foot with the sole of an ordinary shoe, we shall perceive at once that the middle of the exterior border of the latter is out of the natural line ; the sides of the great and little toe press against the upper of the shoe, and the heel is pressed on all sides by the stiff lining. The extremity of the great too being thus pressed, the nail is forced into the flesh. The other toes become the seats of corns, bunions and chilblains, also of accumulated perspiration ; the skiu macerates and inflames, and mixing with the products of the sebaceous glands, an offensive odor is exhaled, and more or less ulcera- tion may result in proportion to attention or neglect of very frequent washing. Another evil occasionally results, namely, the production of flat-footedness or splay foot. 368. In obtaining a properly made boot (Fig. 49), the principal points to be attended to are, that the sole shall be as broad as the foot when the weight of the body rests upon it. In the action of walking the foot expands in breadth and length, — in length often as much as ^x$> in breadth even more. The shoe- maker measures when the person is sitting, and, as a rule, allows only ^ for increase. The heel should be made low and broad, so that the weight is not thrown on the toes, and that the muscles of the calf of the leg be permitted to act, which they cannot do well with a high-heeled boot. The inner line of the boot should be made straight, so as not to push outwjird the. grent toe. The. hygiene rsf the font .sho^jld be fltt'Onded to from infancy. The Indian moccasin is the easiest and most comfort- Fig. 49.— Properly made boot. lO MANUAL OF HYGIENE. 148 of ITof ^' *" '' "''"'^ '*"^' ""^^^'^^^ '' *^« ^^^P« -d -otiou to the feet, and recommends that tl,ey be woven with a separate covermg for each toe, as gloves are made with lingers ^ 370. Infant clothing should be soft in texture, so as not to irritate 371 Children should not be kept penned up, nor under restraint for want of suxtable clothing. They should have clothing which vv^ Ikeep lt^;^t^lb^ti:i:"^^^^^ '^^" ^^^^ ---^^ --^^-^ :! • :i ^ 1- lo Hi CHAPTER XII. I- STRUCTURE OF THE SKIN— IT& FUNCTIONS— OBJECTS OP BATHING AND OP DIFFERENT KINDS OP BATHS— HINTS IN RKOAKD THErHTO. 372. The skin is composed of two principal portions: (1) the epidermis or outer portion, named also the cuticle or scarf-skin ; and (2^ the derma, or inner portion, which is called the true skin. By maceration the layers of the skin may be separated, and their structure examined. 373. The epidermis is a cel^lar structure. The cells p.re arranged in strata or layers, and they differ in their characteristics. This differ- ence leads to a division into two layers : (1) a superficial layer {A Fig. 50), and (2) a deep layer (B). Some physiologists make a further sul^ division, four layers of the epidermis being distinguished by them. The epidermis is continually being reproduced from a stratum of plastic lymph poured out on the surface of the derma, or inner por- tion. First the deep layer of cells is formed; these are round or prismoidal and soft. They are constantly coming into existence, and pushing those above them outwards in the direction of the external surface : as the cells are forced out they gradually assume the flat- tened hard appearance of the superficial layer, which is thus composed of thin hard plates or scales, which become dry, and are finally 'le- tached and cast off as worn-out material. The deep layer is composed of soft round or prismoidal cells. Some of these contain pigmentary deposit, which gives to different races of people their different colors, a darker skin being characteristic of a greater abundance of deposit. The epidermis, then, is the product of the derma, which it serves to envelop, protect and defend. It also possesses the function of dimin- ishing the evolution of heat and the amount of watery evaporation from the body. 374. The derma, or true skin, has numerous conical eminences or projections, called papillce (C). These are abundantly supplied with small blood-veasels and nerves, and are highly sensitive. Where the II 'ii MANUAL OF HYGIENE. 145 sense of touch is most acute there are found several irregular spiral coils of nerve filaments, associated with peculiar little bodies called "tactile corimscles," situated in the papillse. In the pulps of the fingers these tactile corpuscles are most abundant. Papillje are very m merous on the palmar surface of the hands and fingers, where a number of curved ridges and intermediate furrows may be seen. In these parallel curved ridges may be found double rows of papilla3. The intermediate furrows are the interspaces between pairs of papilla) in the ridges. There are also transverse furrows dividing the ridges into quadrangular parts. In the centre of each quadrangular part is situated a small orifice, which is the mouth of a sweat gland, or sudoriferous duct. The nerves and arteries may be seen enter- ing the skin through the areolae in the deeper portions, to distribute themselves in the papillary, and other layers of the skin. 375. The sebaceous glands (2>) are saccu- lated and contain an oily opaque secretion. They are situated most abundantly about the scalp, mouth, face, and ear. Each gland has a single duct which opens either at the cutaneous surface or into a hair follicle. 376. The sudoriferous glands, or swea* glands (i?), are distributed over every portion of the surface of the body. They are more abundant in some parts than others, as on the palmar surface of the hands, where it is estimated that there are, in each square inch, about 3,528. The average number per square inch of the whole surface of the body is sup- posed to be about 2,800, and the total Fip. 5o.-section of skin : (a) su- """'^^^ ^^""^^ 7,000,000. These glands are ^te*eXn1"f U papfIl^I" *"^'^1'^''- C»^« extremity is coiled up in the wSrfyriuV,1andT")'B^^^^^ subcutancous tissuc J a straight duct leads buibiTifhair'Zftl^O mu^ct ^''^^^ *^^ Convoluted portion to the spiral which erects the hair. extremity (F) in the epidermis. It ter- minates on the surface of the skin in an opening or pore. The ex ternal opening is directed obliquely towards the surface. The lami- ( i ( il n I :r 146 MANUAL OF HYGIENE. ■m^ nated structure of the external layer of the epidermis forms a sort of valve in the oblique termination of the tube. 377. The hairs and the nails are cells of the epidermis in a modified form. Hairs may, for convenience of description, be divided into a root or bulb {G), and shaft or stem (X). The shaft is cylindrical. The root or bulb of the hair is enclosed in a sheath 'billed a follicle. This follicle is merely an involution of the epidermis. It extends through the derma into the corium, and sometimes it penetrates into the subcutaneous tissue, as in the case of large hairs. The process of the formation and growth of a hair from its follicle is similar to the formation of the cells of the epidermis from the surface of the papil- lary layer of the derma. 378. The skin Is not to be viewed as an independent tissue, with functions for its own benefit, but as a portion of a general system, existing by its dependence upon the other parts, and also contributing its full share to the maintenance of the health of the whole body. 379. In the process of growth and nutrition constantly going on in the human body, certain nutritive elements are supplied. These are appropriated by the several tissues, and assimilated in accordance with the principles of vegetative life in the body. The animal func- tions are carried on at the expense of the vegetative life. The exercise of the functions of the brain, nervous system and muscles are essen- tially destructive to these organs. Every thought, sensation or mus- cular action necessarily involves a destruction of corresponding tissue. In this way there is a continual process of waste and repair. The various tissues are being re-formed, the worn-out material being dis- integrated and thrown out. 380. That there are organs set apart for gettinc, rid of effete or used- up material, the retention of which is not only injurious, but positively fatal to life, was incidentally mentioned when we treated of the blood. These organs are said to perform the function of excretion. We find that they are all mutually dependent on each other. Especially is this mutual relationship found to exist between the skin, lungs and kidneys. Waste products, such as various organic matters, carbonic acid, certain salts and water are carried off" by them. The aki'T) eliminates a comparatively small quantity of salts, a little carbonic acid, and a large quantity of water, in the form of perspiration. It MANUAL OF HYGIENE. 147 also excretes various acids of the fatty series, such as acetic, formic, butyric, etc. The greater part of the salts and urea, with an insignifi- cant portion of the carbonic acid pass off by the kidneys. The action of the lungs has been fully described. 381. It is estimated that the maximum loss by the slont iifty-seven parts of phosphate to eight of carbonate. Wheat, rye, corn and barley contain phosphates in considerable quantities. Iron, although it only exists in small quantities, plays an important part in the blood corpuscles and in the coloring matter of muscle. 421. The forms in which water exists in the body have been described (Sec. 412.) As a food it acts as a solvent and vehicle to other matters, and is largely utilized in the excretions from the skin, kid- neys and lungs. It exists uncombined in the various kinds of fruits and vegetables, which contain from seventy-five to ninety per cent, of it. The various inorganic elements derived by plants from the soil are carried to the leaves and other parts by the water thus abun- dantly supplied to the plant. 422. Of the fact that a mixed diet is not only acceptable, but neces- sary, evidence is furnished from several sources: (1) from instinc- tive proclivities, (2) from the comparative anatomy of the organs of digestion, (3) from experiments and experience, (4) from comparisons of the composition of such substances as bread and meat, with the amounts of carbon and nitrogen daily excreted by the lun<^s skin kidneys and bowels: to obtain a proper amount of nitrogen a quantity of bread must be consumed containing double the amount of carbon required ; and of meat five times more must be consumed to supT)ly the carbon than is necessary to furnish the nitrogen. In proportion to the increase of fatty and saccharine matter, the supply of bread may be diminished. Change in the combinations in which food is presented is also very beneficial. 423. Dietaries should be constructed so as to allow of a due admix- ture of animal and~vegetable food containing substances belonwinf to all the classes previously mentioned. Even this Isl not enough : the articles must be varied at times, or functional derangement and disease may occur. I i 158 MANUAL OF HYGIENE. 424. The necessary quantity of food per diem is in some measure modified by tlie age, sex luul amount of exeixiise taken. The follow- ing table we have compiled from the recorded figui-es of a number of observers : — The amounts of the undermen- tioned substances are calculat- ed OS "water-free," the water, (50 to 60 per cent.), naturally co- existing with them havinif been separated from them. This ad- dition must he made in supply- ing the actual food. 1"° • o o m "3 SS « - m! -J 'Si « t. 3 — eS w S O.IU .'"i IV c1 51 ;g -<2 ^=.& 1^-° ~3 a cs o ,1. "Si! fc, Oj "*-* '■I oj dj fc. > C ._ C3 tj ■Q Nitrogenous matter Fats Carbo-hydrates . . . Mineral substances Total food . p 3 ; li o* is's j|§ !?§ BJ3 c o 8 d .2 o^i oz. oz. oz. avoir, avoir, avoir. 2.16 0.67 11.84 0.5 3.35 4.86 1.15 2.97 15.3 14.81 06 I 1.19 .23 Pi oz avoir. 4.5S 2.96 o -♦J B f c TO t^ ea o oz. avoir. C o oz. avoir. 4 83 4.12 14.2612.40 1.06 1.06 15.17 20.40 23.83 22.87 22.41 I I I 3.52 3 52 0} c « oz. avoir. 6.21 3 44 1^ 3 ■» 0-3 "o to ^^ i§ != S -Ed E3 i-E 'o-e ,"3 1^- o-E T ° B 3 1. 5.P 00 eS.*~ I 8.4618.13 0.89 16.39 13 29.08 i .017 .031 .007 ■ .019 .080 i .095 .003 ' .007 .107 .152 During infancy and childhood more food is eaten in proportion to the size of the body than in adult age. and more is required, in conse- quence of the development of tissue which is taking place. The kind of work in which people are engaged must also be con- sidered : brain woikers require more phosphorus than those whose work does not require much thought. The athlete in training requires much nitrogenous food. • A ma)i nf avonvgo height s,rA weight (say 150 Ihs.) t In children the proportionate amount would bo rather more. u MANUAL OF HYGIENE. 159 j:m .«§ _^_ ^* X «' '^ ■£ ^i <£ o7 T O C «^ S b ■3 a5 .s c s:g 0/ ts o . CO J3 «,« g 5 t*- til ^^ CD Q 2 3 Si ' »§^ a ' 3 1 g^ii. ! ■0 425. Climate has also to be considered. The amount of food taken m warm c .mates is. a« a rule, less than that taken in cold ones. The East luc .an lives on a little rice, while the Greenlander eats several pound, of fat meat daily, washing it down with train oil The inhabitants of Arctic regions appear to have a natural relish for he oleaginous or fatty foods with which nature has provided them m the seals whales, and other anin.als in these regions. It ha^ also been asserted by travellers in extreme northern latitudes, that they experienced a positive craving for fats, although while previously resid- ing m warmer climates they lived principally on fruits and vegetables which contain large proportions of water and smaller proportions of heat-producng material, the latter in the more suitable form of carbo- hydrates The fruits and vegetables co.nn.only used in hot countries contain from eight to twelve per cent, of heat-producing n.atter, or carbohydrates, while the fats and oils used by inhabitants of northern climates contain fron. sixty-six to eighty per cent of carbon. 426. From the vegetable world comes, directly or indirectly, the p.-incipa part of the food of man. Plants, under the influence of solar light ana heat, have the power of taking out of the earth and sur- rounding air certain elements and constructing compound substances suitable for the support of anin.al life. In this way plant life is con- stantly engaged in supplying food for a.nmal life. Some animals live on vegetable food alone; some on animal food alone; others, again, on both vegetable and aninml food. When animal food is used it contains organic compounds which were derived from vegetables or plaiits, and thus, too, plant life is indirectly the source of animal food articles of food must be known in order to provide the relative pro- portions most conducive to the healthy maintenance of the body O.i the next page will be found the percentage composition of a number of the most common articles taken from a table furnished by Letheby with additions (n.arked a) fro.n one furnished by Parkes.* We have added to the table a few articles (marked c) which are in common use in Canada, and of which the analysis h rven separately by Dr Pavy i J • From a Treatise on Food and Dietetics, by F. W. Pavy. M.D., F.E.S.. Wood's Library U . 2 2.8 3.45—^ 5.4 6.4 Fat. 1 R i.a 2.0 5.6 8.1 3.0 0.7 2.1 2.8 0.2 0.2 0.5 6.5 3 9 26.7 0.4 1.8 0.7 24.3 3.6 2it.8 4.9 31.1 l.'-..8 S9 U.8 ,.i.3 4.1 15.45 :w, 2.9 1.- 30.7 8:? Salts. 3 1.7 L7 30 1.7 2.5 0.5 2.5 32 0.7 1.0 1.0 0.6 7 0.8 1.8 0.45 0.8 0.8 5.4 5.1 4.4 4.8 3.5 4.7 2.3 2.1 2.9 3.0 2.95 1.2 1.0 2.7 1.6 1.3 2.0 0.2 428. Wheat ov n , to the gluten which it contains its aptitude to be made into breax^. In all the farmaceous seeds (such as wheat, oats, barley and corn), albumen, gluten and casein exist in large propor- MANUAL OF HYGIENE. 161 SnIU. 3 1.7 1.7 3.0 1.7 2.5 0.5 2.5 32 0.7 I.O 1.0 0.6 7 0.8 1.8 0.45 0.8 0.8 5.4 5.1 4.4 4.8 3.5 4.7 2.3 2.1 2.9 3.0 2.95 1.2 1.0 2.7 1.0 1.3 2.0 0.2 tions. Fv< 'w one to over three per cent, of njinenil bono-foruiiug matter is also contained in all these cerealia. 429. Biscuits, cheese and dried leguminous foods such as peas and beans will be found to contain a larg(! amount of nitrogenous prin- ciples, a fact of some importance! under circum.stances wliicli render it difficult to procure flesh meat. It is one of the facts which accounts for the mainf«>nance of vigor, notwithstanding the deprivations en- dured, by the recent military expedition in the North-west territories of Canada. 430. That milk contains .11 the necessary elemen! and in propor- tions a{)proaching those in the dietaries given on page ir)8, will be seen from the foreg.)ing table. The rliy constituents of a pint of jiure cow's milk are about as follows : nitrogenous matter (ca.se,in) ."{69 grains; fatty matter, 351 grains; lactinc, in the form of sugar, 486 graiiis ; mineral matter, 72 grains. Thus, a pint of milk equals a mutton chop. Cow's milk contains too much cfusein, and if diluted, too little fat and "<,'ar, for very young infants. The best substitute, therefore, for brek milk would be two parts of cream, one of milk and tlu< e of a solutioii ^f sugar of milk of the strength of two ounces to a pint of water. T'he substitution of barley water for water alone is considered by some to Ix' f good service in rendering the milk curd more digestible. The p r quantity of such milk for an infant is two to three ounces every two hours. If there should be too nmch acidity to digest it, a, little lime water may be given. 431. The digestibility of the various articles must not be lost sight of in the consideration of dietaries ; and with this, age, modes of life and climate have much to do. Individual peculiarities too have a strong modifying influence. Hard and cohesiti; articles are, as a i-ule, diflicult of digestion. Experience is the best guide in this mat- ter. Articles are more digestible when fresh ; we must except fresh bread and recently killed meat. 432. Modes of cooking gteatly modify the nutritive properties of food. In boiling meat the loss of weight is about twenty to thirty per cent. To retain the salts and soluble substances in the meat the piece should be left large, placed in boiling water for a few minutes, to coagulate the albumen, and then cooked at a lower temperature. To make good L jth the meat should be cut small, put into cold water, t -4 I I I I 162 ' 1 if I B MANUAL OF HYGIENE. There is not the amount 11 broths obtained by the Hi and then warmed to a temperature of 150 of nutriment that is commonly supposed action of heated water. 433. Broth may be made without heat by the addition of four drops of muriatic acid to a pint of water and lialf a pound of beef. Such brotli is riclier in soluble albumen. If rather more muriatic acid be used, but no salt, a heat of 130^ Fahr. may be applied. 434. In roasting, the loss varies from twenty to thirty-five per cent. To retain the juices the meat must be first subjected to intense heat," and afterwards cooked slowly. 435. Beverages .such as milk, tea, coffi'e, chocolate and cocoa have of late years superseded beer and wnie to a gieat extent as ordinary drinks at meals. In hot weather, lime or lor.ion juice foi-ms, with sweetened water, not only an agreeable drink, but, taken daily on long voyages, when fresh foods are scarce, it is an excellent pre- ventive of scurvy. Farinaceous drinks, such as oatmeal-water mixed in the proportion of three or four ounces of oatmeal to the gallon of water, are very refreshing for persons engaged in the harvost'^field, or otherwise exposed to heat and fatigue. 436. Condiments are substances which give piquancy and flavor to food, stimulating the salivary glands and stomach. 437. Diseases connected with food may result from excess, impurity or deficiency of it, or to a disproportion of the various nutritive prin- ciples. Excess will lead to constipation or to irritation, resultin.r in diarrhiea, fcetor of breath and dyspepsia. When albuminates passlnto the system in excess, congestions and enlargement of the liver, and a general state of plethora, with fatty degeneration of the heart, may ensue ; and when but little exercise is taken they may give rise to gout. In the endeavor to prevent these results the kidneys throw off a large amount of urea and urates. Excess of starches and fats delays metamorphosis of nitrogenous tissues and produces too much fat, particularly if the drinking of large quantities of fluid, such as beer, is indulged in. The success of Mr. Banting's treatment of obesity IS prnicipally owing to the lessened interference with the oxidation of fat consequent on the entire deprivation of sugar and starches. In starvation, or deficiency of food, the tissues of the body are consumed for the production of heat and energy, and their place not MANUAL OF HYGIENE. 168 l)eins supplied, rapid loss of weight is the consequence. Typhus fever, scurvy, and aiiiriiiia or Idoodlessncss, aic some of tlid consequences. 438. Diseases often arise from altered quality of meat, such, for example, as may be caused by epidemic plouro-pneunionia, foot-and- mouth disease., carbuncular fever, rinderpest, braxy (in'sheep), trichina) and other piuasites. There is a very great discrepancy of evidence to be found in the statements made from 1737 down to the present time regarding diseases presumed to have arisen from the use of the incat of diseased animals, and the difference of opinion is so great as to lead to the conclusion that the stage of the disease, or the part eaten, or the mode of cooking must have great influence, and that more study than has yet been given to this sul)ject is necessary to clear up the great varieties of stfitement. The llesh of overdriven animals is said to be unwholesome. Much doubt exists as to the effects of epidemic pleuropneumonia on meat. Kaffirs have been known to eat, without injury, the moat of cattle destroyed by this disease The apparent increase in the number of cases of malignant pustule in men has been ascribed to the eating of the flesh of animals suffering from it, but it is quite likely that inoculation may have taken place in other ways. The same remarks apply to the meat of cattle or sheep which have died from splenic apoplexy, from braxy, from rinder- pest, and from foot-and-mouth disease. On general principles we must conclude that the tendency of all diseases is to deteriorate the flesh, and it is of gi-eat importance to have the animals as healthy as possible. 439. Meat partially decomposed or tainted is liable to produce disagreeable and dangerous results. Sausages and jiork pies sometimes become poisonous from the formation of a substance, perhaps fatty, the exact nature of which is as yet unknown. 440. Tuberculosis.— Observations of numerous German and English physicians have delinitely established the fact that raw tuberculous matter taken from man and animals and eaten by otiier animals may produce tuberculosis in the latter ; that the milk of tuberculous animals will at times produce consumption in susceptible subjects, especially when the morbid deposit has taken place in the udder ; and that tuber- culosis is very common amongst cows fed on distillery wash, especially if they are kept in warm or crowded stables. Although robust indi- viduals may withstand the influence of tubercle taken into the stomach, I ' , i II ! 164 MANUAL OF HYGiENE. it must be otherwise with the weak and young, those with poor feeding and bad air, living in damp, sunless localities, and subjected to much exposure. 441. The victims of trichinosis are persons who eat raw meat highly seasoned; instead of being cooked. This is most common among Germans. The disease is one in some measure resemblin3 .i 170 MANUAL OF HYGIENE. w 1 1 ?!• the influence of these several chambers and their products alone but m great part through the chemical agency of copLs secr.Z"s tha are formed in glandular I,odies in the neighborhood ZZ t wards conveyed into the di.erent chambers ff ^:^Z:^^ :^^ The regular employn,ent of these in.portant organs, ^o essenll o 2 con^nuance of individual existence, has not b^en I'eft ^th C^^^^^^^^^^ to he nsk of be.n, neglected, through caprice or accide^ but strong Xir^ been implanted in us, by .hieh .e are i;stincti::;y^ 462. We are ied to take food by hunger and thirst. If hunger be not soon appeased, an uneasy sensation of gnawing occurs whtch IS referred to the pit of the stomach ; if thirst be not slaked 1 mouth and throat become dry and parched. 81eep aZ^ste It tion of hunger, and violent emotions of the mind pL-ent it. 463. In the mouth solid food is divided into fragments and rubbed down with a fluid to the consistence of a pulp, that its flavor may produce an impression upon the neighboring sentient surface! Z tha It may in the act of deglutition be readily conveyed n eoua per ions along the gullet. The inner surface of'the nil £ With a mucous men.brane which is continuous at the lips with the skin. Its vaulted roof (Fig. .1. /.) is formed by the hard ll^^^^^^ around which are set the teeth m their sockets, the tongue (c) form mg the floor. TU. ,u.,seular .alls of the lips' and cheels retiinTe food in the mouth during mastication. 464. Saliva is poured into the mouth by three glands on either side— the parotid (Fig, 52), the submaxillary and the subh:nf/ual,~&nd by many smaller glandular bodies in the lips and cheeks, termed the labial and buccal glands. There is a difference in the structure of these glands, according as they secrete pure saliva' or saliva mixed with mucus, or pure mucus. Mixed saliva is composed (according to Prerichs) of water, ptyalin, proteids, fat, epithelial scales, f i--. 53. A lobule of thu lutiotiu giutnl highly magnifled. MANUAL OF HYGIENE. 171 sodium chloride, potassium chloride, and other salts. It has the power of converting starch into glucose or grape-sugar. This action is due to the presence of the ferment ptyalm. 465. The rate of flow and quantity of saliva are subject to variation. When the tongue and muscles employed in mastication are at rest, and the nerves of the mouth are subject to no unusual stimulus, the quantity is only sufficient for keeping the mouth moist. Mental impressions produced by the sight or thought of food have a tendency to increase it. The quantity secreted is irom one to three pints per diem. 466. The teeth in different classes of animals differ considerably, being adapted to the kinds of food best suited to the digestive and other functions of the animal. In some they are evidently intended for seizing and lacerating animal food, in others, on the contrary, they are better fitted for cropping and triturating vegcta' le foods. It has been shown in Chapter XIII. that a mixed diet of animal and vegetable food is that best suited to the wants of man : and we lind that his teetli are so \'aried in shape as to be well adapted for masticating these different kinds of food : he has chisel-edged incisors (Fig. 53, /), for detaching the morsel he is about to masticate ; pointed canines (O and C) and bicuspids (B), for lacerating ; and broad molnrs{M), for tritu rating. 467. The temporary or milk teeth (/, 0, J/, Fig. 53) have only a very sliort period of existence, which is due to the growth of the permanent teeth, pushing their way up from beneath, absorbing in their progress the whole of the fan" of each milk tooth, and leaving at length only the crown as a mere shell which is shed to n\ake way for the eruption of the permanent tooth. 468. The average times of the eruption of the temporary and per- manent teeth are shown in the accompanying tables (Fig. 54). In both cases the eruption of any given tooth of the lower jaw nrecedes as a rule, th« corresponding tooth of the upper jaw. Fit;, ."ia— The teeth of a eliilil between h and 7 year old : /, O, M, teniporniy sot, incisors, eiinlnes an1 Times of niiption of the toMiponio ai"l penn.neiit sets of teeth resuectivelv 1, ineisors ; (;. <„nine8 ; B, hieuspids ; M, molars. "-sptiineiy . inserted in the aJ^^eolar pr„rr,, of the jaw. The tooth is thus «xed by fang and neck, and the crown is employed in masticating the food and ill articulating vocal sounds. A longitudi- nal section of a tooth is shown in Fio-. 55. In tlie centre the ,lent!ne or ivory (d) is hollowed out into a cavity resembling the outline ot the tooth, called ih(i pulp cavity, from its contain- ing !i, sensitive and vascular mass called the tooth pulp, composed of connective tissue, blood vessels, and nerves. These vessels and nerves enter the pulp through a small opening at the extremity of the fang. The cavity is seen to be wrought in the duller-colored substance or bone of the tooth, and the glistening enamel (a) ap- peal's disposed in a thin layer, thickest upon the cutting «^i-e or grinding surface of the crown, ^I'lf' vanishing upon the neck of the tooth (b) 470, The teeth consist of ordinary bone or osseous tissue, and a variety of it called dentine, which contains less animal matter,' and is Pljf. 5.5. - Section ofaiiiolui tooth : a, enamel ; d, dentine ; c, cement. MANUAL OF HYGIENE. 173 therefore very hard. The enmnd investing the crown of the tooth, and forming that part which is exposed in the mouth to the contact of external substances, is lia.dcr and more compact than dentine and is of peculiar structure, consisting of a congeries of hexagonal rods placed endwise, side by side, their deep surface resting on the dentine. Enamel is the le^st constant of the dental tissues. The crusta petrosa or rmient (o,) is disposed as a permanent thin layer of osseous tissue on the roots of the teeth, and it also invests the enamel with a delicate film on the «rst emergence of the tooth from the gum. The cavity of the teeth, containing the pulp, is the medium for the nutritient vessels and the nerves to find access to the internal sui'face. 471. The act of chewing or mastication in man is performed by an up and down movement, and a lateral grinding movement of the lower range of teeth against the upper. 472. In deglutition, or the act of swallowing, the morsel of food is thrown by the tongue to the back part of the throat and swallowed, as soon as the saliva has lendered it Ht. The upper part of the pharynx (opposite to ff, Fig. ')]), is drawn upwards to receive it. Three muscles, tej-med the upper, middle, and lower constiictors, then throw their fibres around the pharynx, their action being such as to compress and propel downwards any substance that has found entrance into it. Several passag< s open towards the pharynx, and there are contiivances which limit the progress of the food to one direction only, and force it to descend towards the resophagus, instead of allowing it to make its escape by the nostrils, the mouth, or the windpipe. These ai-e remarkable, and well deserve attention. 473. The nostrils are protected by the soft nalate (oIar i)i-ocesses occurs ; the teeth become loose and drop out. Derange nionts of the digestive functions and impairment of the whole economy may result. One of the chief causes of caries or decay of the teeth is tlie fermentation and decomposition of food about and between them. Gritty tooth powders should be carefully avoided. 484. The importance of regularity in taking nourishment is admitted liy all writers. The rp(iuii(Muents of the human system seem to be best met by having three meals daily-— inorning, mid-day and evening. — and there should be no eating between meals. The processes of digestion, which have been described, require a sufficient length of time for their performance, and we must not add fresh material to a half completed process. The e\ ening meal should precede the usual time for going to bed by at least three or four hours. Persons who from any cause have feelings of exhaustion between meals may take a glass of milk with advantage, b'ome persons cannot sleep if some houi-s ha\ e elapsed since they have partaken of food. To such persons a little bread and miik, or other easily digested food, will be beneficial. We must not, on the one hand, allow so long a period to elapse with- out food that the tissues become exhausted, and the craving for food becomes painful or unpleasant ; nor, on the other hand, connnence a second process of fermentation before the digestive chambers have finished the elaboration of a previous supply of food. 485. Insufficient time for partaking of a meal is a very comnion error. Food requires to be well masticated in order that it may bo in a finely divided state when mixed with the digestive fluids, and also that it may be mixed with a sufficient quantity of saliva : the act of chew- ing causes an increase in the How o2 the latter. 486. We should not take fluids to moisten a bolus in the mouth. This, too, will diminish the amount of saliva: there will not be the same demand for it if we have an extraneous fluid to perform one of its mechanical offices. In this way salivary digestion will be impaired; the gastric fluid also becomes diluted and weakened. t r d F c ii i MANUAL OF HYGIENE. 179 4'>i>io.s tnoro proniinont,, as .•...npan.d sviM, tho Iilood proceeds on its course fr cliistio cleiiK'nt. As "11 the impulse „f tlio heart, it -.-s ,no..e a.ul „.„.. suhjeet to the control of those ,.emote or iKstal a,,enes. as they are calh.i. Nature has provided them wit . l":;;-;;<- <1— t,,.. and re.ulatin. thn flow of l.iood in acco'huco ^v.th the r.>,,uiremen(s of the l.odv. Tl '"toiUauco special function it IS to impart power to tliese Here are ner\e (iiir,,s whose ininnte artei : ' •'».« then,, Uy vntuo of their .nnscdar coats, to contract nd ^'"' ^»"««' ^'t-. ^^t *■•- very extrem y of tlu artenes h.ve no nu.scular elen.ent. V.y virtue of their elltU t.y, they a..e exp.n.le.l wi.en a ]a,.,o supply ..f hh.od is sent to " -.1 agan. constructed when the supply is lessenest observed 1)y noticing their physiological influ- ence on the iris, heart, blood-vessels Kifr. 58. The iris and ciiiar.v procosscs, as "^'"^ viscera. The iris is made up of m. r,., ^"'' f " ":*:""• , ••'""'^^•"g ^"^d circular nu,scular fibres (I g. r)S) : contraction of the radiating fibres causes the pupil of the eye ,1 , T °P'"'" ''S'"'^"'' *'^« d'^'"eter of the pupil is dimin ^ """ !.wiiatn.g muscular fibres, through its MANUAT, op lIVfilKNE. isn ) I _ prunary affinity f„r (ho sympathrtic sysi,.,,. of norvo.s wl.ich ospocially controls th.s. (il„vs. A lur^.r an.l dan^M-rous ,loso cauM-s paralysis ot tlu, cnn.lar nu.soular (il.n.s also, tl.nui;,.!, its f„rtl„,. ^Hion o.. the corel.ro-spinal syst<..n of nerves, a.ui hence the pupil hecon.es lar}/ ily dilated. 498. The effect of opium upon the circulation is t.. act (irst o„ the l.lood-vessels, and, s,...n,ulurily, on tin- heart: to cause an iM.-reased v.Iun.e in the pulse from diminished arterial tonicity, and then a lower rate of heat, when the dose has been sufficient and has h-.d tune to influence the heart. Mr. Thomas claims that the action of alcohol ,s precisely similar to that of opi„n, : it primarily affi^ets the sympathetic system, s..condarily the cerebro-sj.inal syste.n of nerves- It has the same acti.m on th(. iris, contracting and dilating the pupil m the same way; it lirst atta,K-s the l.lood-vessels through the sy„.- I.athet.c nerves, din.inishing their tonicity ; this rehVv.s the [...ut of blood-pressure, a.ul .anses a temporary acceleration of the pulse and general circulation. 499. All these indications point to a paralyzing or sedative action, to diminution of control over the circulatory system an.l not to ival stimulation. The sij,ms of apparent stimulation by alcohol ari.se from the primary affinity that certain doses of alcohol have for certain nerve structures. 500. Experiments on animals have been made with a vi.w to discover the principles of action of the vasomotor mechanisn, the nerve-control of the blood-vessels. As a result of some of these experiments, it is recorded* that in manunalia, the division of the sympathetic nerve in the neck on one side causes a dilatation of the imnute arteries of the head on the same side, and an increased How of blood to these parts. If the experiment is performed on a rabbit the ear of the side operated on is much redder than norn.al, its arteries are obviously dilated, its veins unusually full ; innumerable minute vessels, before invisible, come into view, and the temperature may be more than a degree higher than on the other side. Division of the sciatic nerve (the large nerve of the leg) causes a similar dila- tation of the small arteries of the leg and foot. The vessels of the toes appear full of Wood,^iMd a tJuM-mometer placed between •Text-book of Phy8ioIo«:y, by M. FoBter, M.a:m.D.. F.R.S.. Leit^i on, 1881. p. 264. ~ 184 MANITAL OF HVdtKNE. ri'i the tors indiciitos a risn of tomperaturG amounting to several de- f,'roes. Numerous other experiments have been performed, showing precisely similiir ellects in other parts of the body. M. Htratiss, in the Amrrimii Journal of the Mi'dical Scinices, is re- ported as n^latiny the ease of a sol.iier who suflered from a disease of tlie vasomotor Jiorves of the left foot. The foot and toes wei-e swc»Ilen owing to the engorgement of the v.-ssels, especially when the patient was sitting and th(. leg hanging down. Tn tliis case the temperature of both sides was reported daily. Tt was found that theie was a difFerenco between the two, that of tlu' left being from two to four degrees higher than the right. From these, and many similar facts, it appears that increas(^ of temperature on the surface of the body, or in any part, may arise from al)sti-action of Jicat from another pait. ' It seems very probable that the rise in temperature observed dui-ing the first action of alcohol on tlie system is only the result of its sechitive or paralyzing influence on the minute arteries controlling tlie blood supply. 501. Alcohol does not maintain animal heat, but, on the contrary, permits an excessive expenditure of it. It is admitted by all observers tliat the secondary efiect of alcoliol is to lower the temixnature of the body. Even those who advocate its use as a stimulant, and wlio affirm that it may, under some circumstances, be of value as a food, are ready to admit its secondary efiect in inducing aniinal heat. 502. Arctic voyagers have given l's their experience regarding the use of spirits in enabling men to endure long-continued cold. Dr. Rae, Dr. Kane, Dr. Hayes, and all those who have been engaged on expeditions in Polar regions, are agreed in the view that the use of alcohol in moderate quantities diminishes the power to resist cold. ^ Experiences in the Red River Expedition, in the Asliantee war, in India, and in otlier regions, sliow that the al)ility to endure fatigue and to resist disease is lessened hy the habitual use of alcoholic stimulants. Such evidence as this coincides witli the results of obser- vations regarding the physiological effects of alcohol on the blood, and in the circulatory and nervous systems of man. We may conclude that alcohol does not supply the place of foods in maintaining the vigor or animal heat of tlie body. 503. When alcohol comes in contact with living tissues it hardens f rt I ( i MANUAL OF HYGIENK. 185 them. This pliysi()lofri,,U ,.ir,.et is said to ho duo to tho abstraction of water and the coagulation or condensation of ail.uni.'n. 504. In the mouth alcohol causos an increased ||„\v „f saliva, and a hardening of tho epithelium, or lining' memhrane, wf.ich is recog- nized hy a feeling of contraction or "[)uckerin« of the mouth." In this way the n.-itural condition of tlu; tissues is impaired. 505. Repeated and long-continued use of alcoholic stimulants finally brings about an unnatural condition and impaired function, which may be seen in the glazed and fissured tongue of the habitual 'drinker of ardent spirits, 506. Congestion of the mucous membrane, or h'ning membrane of the stomach, results from the habitual us.; of alcohol. Tlie minute arteries in this membrane become dilated, and allow an increased amount of bloofi to pass through them ; the natural seci'etion of the stomach, the gastric fluid, is tempoiarily increased by this exce.s- sive flow of blood. The long-continued and habitual use of alcohol thus brings on a chronic congestion, or gastric catarrh. The exces- sive natural secretion now begins to change to an unnatural one, the digestive functions being at the same time imi)aired. The glands, or mucous follicles, begin to show evidence of organic chancre The continued excessive flow of blood induced by constant alcoholic stimulation causes an increased growth of the connective tissue. This encroaches upon the glands and mucous follicles, which are con.stantly being drained by an unnatural excessive secretion, and thus they arc reduced in size, and fail to Vr:- tain their healthy'for.n and function. Alcohol is also said to precipitate pepsin of the gastric fluid and arrest the activity of the ferment. 507. The Information derived by Dr. Beaumont in the case of Alexis St. Martm is valuable in this connection. This man was accidentally wounded in such a way that through the imperfectly healed wound the operations of the stomach could be watched. He had been habit- ually a temperate and healthy man. "After drinking ardent spirits for eight or ten days, he complained of no pain, and showed no signs of mdisposition-said he felt well, and had a good appetite The inner membrane of the stomach, however, was in an unnatural condition, having an erythematous or rose-colored appearance and apthous or inflamed spots. The secretion also was unnatural" ^11 r4 -l m h 186 MANUAL OF HYOIENE. TIn.Ier tho contin.,,.! uso of spirits this unnatural condition mcMrusod, un.l it is reported that, "Tlu, gastric (h.i.is .-xtraot-.l tnm. tho sto.nufh this morning w«ro n.ixcd with a largo portion of ♦hick rcpy nnious, and considerahh* nmoo-purulont matter, slightly lH.^'.-d with hl.,od. roso.nl.iing tho disohargo fron, tho huwols in .Js "» ••'"•••"..• dysoMtory." During all this (h.aMgo.l oondition, |)r l..''UMnont remarks that, "St. ^[artin complained of no syn.pto.ns .nd.catn.g any gonoral domngon.ont of the system, except an nnoasy sonsat.on an.l a tondornoss at the pit of tho ston.ach, somo ,ii//.iness wit.. (Innnoss of vision on stooping and rising again." Those ol.sor- vat.ons prove that woli-n.arkod pathological changes an.l serious derangement of the functions of digestion n.ay oc.-ur without any outward sympton,8 in the case of those who hahitually use spirits even m small quantities. 508 The liver is the organ most influenced next after the stomach. Alcohol .s ahsorhod into tho hloo.l-vessols of tho ston.ach and int<.stines mm the.so ,t passes di.'octly through the portal vein to the liver c<.|ls' Changes are hero observed similar to those in the ston.ach • first' increased functional activity; next, impairn.ent of function; then the organic structure of the liver suHors, fatty .leposits o.-cu,' a,.,| take the place of the natural tissue, the liver is inrproperly nou.ished, and itshnnnessof texture is lost ; the connective tissue increases partly at tho expense of the hepatic colls, and the liyer becomes enlarW- atter- tins, contraction of the suporabundar.t ar.d newly-fo.-n.ed con- nect^ve ti,ssue takes place. This reduction in size brings about that cond.t.on of the liver known as cirrhosis. This disease, comn.on in i.e case ot habitual drinkoi , causes a n.iserable existence, clo.sed by death. ' 509. The kidneys also are injuriously affected by the habitual use of alcohol. It reaches them by the gono,-al ci.'culation, ar.d, therefore does not so quickly or intensely excite inHammatory action in the..; as .n tho live,'. The long-conti.aued use of .spirits, however, causes chronic disease of tho kid.K.ys : as the result of constant irritation, the functions of these organs are impai,-ed, a,.d finally altor^ations of structure are efTected, f.-equently causi.ig the disease known as <.ranu- lar dcgeneiation of the kidneys, or- Brights disease. Deposits of iiiatte.s incapable of o.gani.ation are found in the substance of the r I ^ MANUAL OF IIYCJIKNK. 187 t kidnoys. We havo, first, excessiv-e growth of tl,« ititortul.al or con- nective tis.sno, and then a shrivelliM-r or contraction of tlu, tissuo or suLstanco of tho kidney, to tlio extent, in some instances, of one-half Its natural size. Various other <„;,^tnie elinn.;..s affrwards occur There is a sin.ilarity to l.e ohs.Mved in the altiwaf ions ..f the organic structure of the kidneys and liver, as a result of n.ntinued alcoholic stimulation. In hoth cases, also, the diseases are incural.le after tho or<,'anic clian<,'es hiivc hcon accomplished. Th.. liver an.l kidn.^ys (esj.ccially the latt.T), are en«n«,.d in the function of excretion, or carrying ofl" n„„l.id matters that should bo ejected from the system. The altere.l ...nditions just des<-ril.ed lead to impairment r,f this function. Poisonous materials are thus rct.iined in the l.lood, and dis..as..s of various kinds produced, (iout, rheuma- tism, airecth.ns of the Iwart and other organs, have been kno^vn to arise under these circumstances from very si l^ht exciting causes. Tho natural tendency to repair injuries, resist (lis..ase, and alter morbid conditions, is gi-catly lessened. 510. The direct action of alcohol on the blood is such as to imj-air Its nutritive, formative and rec.Mstnictive powers. The vital proper- ties of the corpuscles aiv partially destroyed and their f/notions impaired. This was well illustrated by Dr. (icorge B. Harriman, of Boston, m connection with a lecture by th(> Kev. Joseph Cook He exhibited, with the aid <.f a microscope and magic lantern, the ma- nilied corpuscles of healthy blood, and also of the blood of inebriates In the presentation of healthy blood, the corpuscles stood out upon the screen clear, round ami well deli„ed. Those of the inebriate were shrunken, distorted, irregular in outline, sometimes without coloring matter, and with here and there growing from them a fuiK^oid fila" ment. It was stated that "alcohol driv.-s out the coloring matter which settles in Hne pigment granules in other morphological elements of the blood, and in the edges of the white corpuscles," and that spores and dark granular pigments were numerous in the fluid of the blood The natural power of the blood to form librine is lessened. This accounts for the fact which has been frequently noticed, viz that the healing process is very slow and feeble in drunkards ; the power to resist contagion is also lessened, and the ability to recover from fevers, erysipelas and other diseases is very much Jess. It is a HI il fl 188 MANUAL OF HYGIENE. if i conunon observation, that tho slightost scratch in the case of an Habitual dniikcr may causi; an in.ho..lthy soro or erysipeks 511. The skin suffers f.on, porv(Mt<-,l action and disordered nutri- tion, as shown l.y frequent c.-uptions on tho faoo and surface of the oody. 512. The removal of superfluous fatty matter Is prevented by the habitual use of alcohol, lloalthy natural deposits of fat beneath the skin, and ,n some other parts of tho body, are necessary, but an undue accuuiulatiou and retention of fatty matter leads to fatty degeneration of muscular tissue and of various organs. Thus exces sive fatty deposit may become a positive oisease, and cause orgaip-c changes which destroy life. In this way, frequently, the natural hardness and vigor of muscles is destroyed, their contractile power IS lessened, and they are said to suller from want of tonicity The muscular structun^ of the walls of the heart and of the arteries is injunousiy artected : they lose their contractile power and natural hnnness, and serious derangemeKb of th(, general circulation results Arteries m this condition frequently give way from the internal pres- sure the blood current, and fatnl ellusions of accumulated blood take place. Apople.vy, paralysis and epilej.sy are sometimes caused by ruptures of the walls of blood-v.vssels in the brain. Alcohol circu- lating Ml the current of arterial blood may cause inllanimation of the internal coats of arteries. ]n this case coagulation of blood is apt to occur as a result of the indammatory changes, and mechanical obstruction of a large artery may b,. produced by a blood clot thus formed : atrophy, or even death, may result in the part so deprived of Its natural support and nutiition. Deposits have been known to occur in the walls of the heart also, as an ellect of the irritation of alcohol. 513. Alcohol acts directly on the brain, the great nervous centre of the body. Hammond has proved that xt has a special affinity for nerve tissue and nerve centres. It has been found in the brain sub- stance, and m the fluid of the ventricles of the brain. That terrible disease, delirium tremens, is caused by excessive drinkin- Many chronic and incural.lo diseases of the brain and nervous sys'tem have resulted from the habitual or excessive use of alcoholic stimulants Among such diseases, paralysis, loss of sight and epileptic tits are f MANUAL OF HYGIENE. 189 most common. They are seou in various sta.^es and degrees of inten- sity. The statistics of asylums prove that insanity is often the result of continued drinking. It is sometimes the cause of indul-ence in the use of intoxicating liquors. " 514. Death may result from an overdose of alcohol. In proportion as intoxication increases, the will power, or controlling power of the cerebro-spinal system, becomes lessened. First the intellectual and moral faculties are blunted, then the part of the brain controllins ,>f the various districts in that city were in direct proportion to tlio numbers of public-houses. The experience of the United Kin-doin IVniperanor. and General Provident Institution has proved that even among persons w}io have passed the examination for life n.suranee, there is a much lar-.-r rate of mortality amongst those "not known to be intemperate" (mt-lerate drinkers) than amongst tota! alistainers. The government retu.-ns obtained in 1849, an.l published by Dr. VV. H. Carpent(>r-, giv(> tlie .ate of mortality among the Europeaii troops in Madias. These troops were divided for purpose of compari- son into three classes - -the total abstainers, the temperate, and the intemperate. 'J'h(> .'eturn of d(>aths is as follows : 1. In Ahstaiiieis ^ n in 1000 2. In Temperate 23 in 1000 3. In Iiitenij.erate 44 in looo 516. The disease statistics amongst these same classes, as ir.dicated by admissions to hospital, were in the proportions of 1,308, 1,415 and 2,148 respectively. Dr. S. G. Howe, of Massachusetts, states that of 300 idiots regarding whom he made inquiries, 145 were children of drunken parents. In addresses by the late Dr. Hitchcock and Dr. W. n. (Jaipenter, the statements of many authorities, both European and American, are giv(>n, all showing that a large amount of d-sease is caused by the use of alcohol. Mr. Madeod, Professor of Surgery 111 (Glasgow lJniv,.rsity, is quoted as saying, "that ninety-nine out of every hundred cases in the accid(Mit wards of our infirmary are the result of drink." Granted that this is an exaggerated estimate, it siiows at least that the proportion must be very lai-ge. 517. Teachers should abstain from all intoxicating drinks. Their own interests require it. In orlishing all that educat'on in the highest sense demands, depends on the example and influence exerted »)y them in the school-room. Therefore all evil habits that tend to impair natural powers of action or thought should be carefully avoided. 518. To set an example of abstinence from the use of all intoxi- cating liquors is the only way to avoid the responsibility of leading w ti MANUAL OF HYGIENE. 191 others into habits of intemperance. Precept cannot exert an influence where practice is at variance with it. 519. Tobacco is injurious when used by young persons whose phy- sical development is not completed. In persons unaccustomed to its use, increased flow of saliva, nausea and muscular weakness are pro- duced. When larger quantities are used, vertigo, general weakness, universal relaxation, depression and increased frequency of the pulse, coolness of the surface, faintness and vomiting ensue. 520. Persons WllO habitually use tobacco in modeiate quantities for a length of time experience its efiects as a nervous sedative. In some an agreeable, tranquilizing effect is produced, quieting restlessness. In persons of nervous temperament it cannot be used even in small quantities without disadvantage, while in others no evil effects follow. 521. The habit should not be indulged In, however, as it yields no good results, and is an uncleanly, useless and expensive practice. Among the more permanent effects resulting from the long-continued use of tobacco, may be mentioned dyspepsia, defective nutrition, emaciation, general debility, palpitation of the heart and hypochon- driasis. 522. Acute poisoning may result from the use of a large quantity, and sometimes death occurs. Dangerous and even fatal effects have resulted from the external application of fresh tobacco juice to the scalp in cases of ring-worm. 523. Opium, chloral, and other narcotics are often indulged in for the sake of their soothing or tranquilizing effects on the system. Fre- quently the practice has grown from their employment during attacks of neuralgia and other nervous affections. In their use there is danger of forming an uncontrollable habit, with disastrous results. 524. Narcotics should never be taken except when prescribed by a physician. The indiscriminate and dangerous manner in which opium in the form of soothing syrups is given to infants by their mothers and nurses, cannot be too strongly condenuied. In addition to the more slowly injurious effect, acute poisoning frequently occurs from the use of these preparations, the strength of which is very variable. 13 CHAPTEE XVI. > WATER : ITS USES— QUANTITY REQUIRED -SOURCES OF SUPPLY— THEIk NATURE— COLLECTION— STORAGE AND DISTRIBUTION— IMPURITIES —THEIR DETECTION— THEIR EFFECTS— PURIFICATION OP WATER — DRINKING-WATER FOR SCHOOLS. 525. A sufficient supply of pure water is necessary for sustaining human life. The uses of water in connection with nutritive changes" and the assimilation of food, have been already considered. The various beverages used by man are mostly water, holding in solution substances of various kinds. Many of these are beneficial if used properly. It is possible, however, to use fluids in such large quanti- ties that the digestive process is interfered with. 526. The function of excretion Is promoted by the drinking of water. Urea, a waste product remaining from the transformations of nitro- genous foods, is naturally thrown out by the kidneys. The retention of this in the blood in undue quantities is very injurious and often fatal to life. A suitable supply of pure water is necessary to main- tain tlie functional activities of the kidneys, and enable them to get rid of poisonous elements. Watei-drinking also favors cutaneous perspiration, especially when encouraged by external warmth ; it thus assists the skin to carry on its function of excreting waste mlterials. The total amount of perspiration is greatly influenced by the amount of fluid drunk, as well as by the condition of the atmosphere and the nature of the food taken. In certain diseases of the kidneys it has been found necessary to reduce the quantity of urea-producing food and increase the amount of water taken by the patient, in order to promote a more healthy action of the excretory organs. 527. A supply of water for bathing is not only a luxury but is necessary for health. The chapter on Bathing rofcrs to this more particularly. Skin diseases and various other affections, such as I. > MANUAL OF HYGIENE. 193 typhus fever, scarlatina, and other malignant fevers, diphtheria, and opthalmia, liave been known to arise from a deficient supply. 528. The quantity of water per head per diem required m a mixed community was measured and caivulated by the late Dr. Parkes, as follows : — For cooking 0.75 gallons. Fluids in drink (water, tea, coffee) 0.33 „ Ablution, including a daily sponge bath, which took fiom 2i to 3 gallons 5.00 „ Share of utensil and house washing 3.00 Share of clothes (laundry) washing 3.00 „ In round numbers 12.00 If general baths and water-closets art used, we must add to this an additional 13.00 Making for house use a total of 25.00 For sick persons this is to be raised to an amount varying from 38 to 46 gallons. The above amounts are those required for domestic use only, irrespective of watering streets, extinguishing fires, and the various requirements of trades and manufactures, for which 5 to 10 gallons more must be added. Other experiments have sustained these figures. In communities where people have had much trouble in carrying water, smaller amounts have been used ; but in some of these instances a want of cleanliness and health has been the result. For obtaining the best sanitary conditions it is necessary that the above amounts should be available. 529. All supplies of fresh water come from the aqueous vapor of the atmosphere. By condensation this falls to the earth as rain or snow ; a portion sinks through the various strata of the earth, and re-appear^ in springs or wells; a portion also flows directly into streams and lakes on the surface, where, by exposure to the sun's rays, it may again be returned in part to the atmosphere as aqueous vapor. The nature of the soils and of the geological strata through which water passes, governs to a great extent its character. 530. Rain water, as it falls, becomes mixed with certain substances contained in the atmosphere, such as carbon dioxide, ammoniacal salts, nitrates, nitrites and oxygen. In thickly populated districts it carries down with it vast quantities of dust, smoke -particles, pro- H ''i L I 194 MANUAL OF HYGIENE. l&f ducts of animal and vegetable decay, and acids or other matter com- monly floating in the air of manufacturing districts. It is also liable to contamination from the roofs of houses from which it k collected Contrivances have been devised for getting rid of the first washings from the roofs, but they are little used. Rain water is devoid of lime or calcium carbonate, which is usually found in spring water, and in a less degree in river or lake water. This constituent renders drink- ing water more sparkling and palatable ; it also furnishes an element lime, necessary for the building up of bone. ' 531. Pure spring water is the most wholesome for drinking pur- poses. The soil, however, is much richer in carbon dioxide than the air, and contains mineral substances, such as oalcium, silica, sodium etc Rain water, receiving more or less carbon dioxide from the air' absorbs an additional quantity in the soil, and becomes charcred with calcium carbonate, sodium silicate, salts of ammonia, and other com- pounds, the elements of which may happen to be present in the various soils. 532. Rivers, streams, lakes and ponds varv much as to purity Where they are passing through, or contiguous to, thickly inhabited districts, organic impurities from dwellings, from manufactories and from all kinds of refuse, are fo nd in abundance, and if the bodies of water are small, the impurities will be the more concentrated. The constant movement of water in swift-running streams, or by the agitation of waves, tends to oxidation of these organic impurities Rivulets and spring brooks passing through rural sections of country are usually pure and very wliolesome. Instances are frequently met with, however, which should lead us to increased watchfulness, lest they may be contaminated in some unsuspected way. Sea-water is sometimes distilled to obtain water for drinking and other domestic purposes. 533. Water In wells is more likely to be contaminated than water from other sources. Contamination of shallow wells is a very com- mon sonrce of disease. Surface water, becoming polluted with the refuse from dwellings in thickly inhabited places, and percolating through loose alluvial soil into wells, is certain to be unlit for drink- ing purposes. Where the soil is rich in organic master, the water may contain 10 to 30 grains per gallon of organic impurities. In and lest Manual of hygiene. 195 marshy districts there may be 10 to 100 grains of vegetable matter. Waters containing a large percentage of such impurities have a yellowish or brownish tint. Occasionally, by constant percolation of surface water through a loose soil, a channel may be formed through which a sudden discharge of impure water may pollute the well. Wells that are not constantly used and very deep wells are liable to become impure from imperfect aeration ; frequent pumping out of the water is necessai-y to maintain a state of purity. Surface water from higher ground, even at a considerable distance, may drain into wells. In order to prevent this a wall of good masonry should project above the surface of the ground from the wall surrounding the well. For a proper distance down in tlie well this wall should be con- structed so as to prevent leakage of surface water into the well. It may be surrounded with puddling clay, well packed, till an imper- vious soil is readied. Roots of trees sometimes find their way into wells, and there decay and produce injurious results. 534. Tubular wells have sometimes to be resorted to. They have been largely used by the British army in foreign service. A per- forated iron tube with a sharp hard point is driven into the ground, other lengths of tube are then attached and driven down, and the process is repeated till water is reached. Driven wells in contami- nated districts should be protected in the same way as others. 535. Sewage contamination of water. The waste and surface waters from dwellings, stables and barn-yards, containing solid and liquid manure, excreta, and numerous animal and vegetable sub- stances, are the most frequent sources of contamination of drinking water. Wells or cisterns near dwellings are often found to contain water impure from this cause. Fig. 59 is a graphic illustration of this source of danger. In some sections of the country great careless- ness has been displayed with regard to the position and management of wells. The owners of houses in the country cannot plead the same scarcity of space as those in the city, am I yet their wells are often contaminated by too close proximity to the sources of impurity just alluded to. There is not sufficient care taken, either, to prevent domestic animals from polluting the wells, the ground around these being often a favorite resort and resting place for cattle and poultry. 536. Provision for the storage of water has to be made in those 1\ \\\\\\\\\\\\\\\\\^ MANUAL OF HYGIENE. 197 cases where we cannot depend upon a constant supply. The best materials for storage-tanks are iron, masonry properly cemented, or siate. Care must be taken to see that no lead is used either as lining or for cementing joints. Lead poisoning has been known to arise from the lids of cisterns being lined with load, in forgetfulness or Ignorance of the fact that the vapor condenses on the lid, forms distilled water, and drips l)aek with lead in solution, into the cistern. Wood is objectionable on account of its tendency to decay, o%ving to the alternate wetting and drying; this is especially the case if°the cistern is sunk in the earth. If used, the more imperishable kinds, such as cedar and oalc, aie to be preferred. 537. Plants in tanks are not, as a rule, objectionable, so long as they continue to grow : tJiey ivather tend to remove dissolved organic matter from the water. But they die in course of time, and then become objectionable as decaying organic matter. Hence, unless the tanks can be carefully watclied, and the dead vegetable matter fre- quently removed, it is better to keep pu.'e water covered in dark tanks so as to minimize vegetable growth. Tiiey .siunild be ventilated. 538. When pipes for the distribution of water are made of lead, the material most commonly used, there is great danger of lead poisonin "^ '^ = neutral or „c„Iy », , l' """"™ '•"»""»■ '"'"ter is usual],- aud «,e acidu, ^,,-sap,.i'';::';2;: r -r ;:»■ ^°""'r .^''"'-'^ If alkaline, and the allcalinifv, I- *° carbonic acid. Negative evidence obt4ed i„ 'J. ",■''" V° ""'"'" '""■'"'■»"■ positive evidence ninv be. '^ "° ""'"«. but the If a yellow or yellowish W;;:.:;' "^f ^^/essler's solution, ammoniacal salts are indicatorl This i 7, , ™'' ''""'^'"^ «'' suspicious manifestation If H.« . ' 1 regarded as a very color distinct, the water' niav lo ^"".^ "'' " considerable or the color may be obscure wTn^ I^ 'r^r^^' f ^^^^^^ ''' owing to the hardness of the water ,1 .. ^ °'/"''^^ Precipitate, cannot be observed after stanc it'' T ''"''' '^ '^'' ^^"«^ ^^^^v made and tested as before. ' '"' ^''^"'■^' " '^^^''^^^'^ "'ay be 556. Nitrites.— Pou I sonm «f +i . . i™ps „, pure suipbu,; : *;:';:;""'; ^^^ "■"=• -^^ » °- « potassium solutiou (also cl.eu ic I v , " '''^'"' "' ""o "Me of Aately appears, the water is i„,„„„ I , , , "° ''°'""' '"""=" very impure water. I„ tlii, tj . ' "'' "" ""'o'' 'ndicates aJways be ruade with pure disti W CatT'Tri^ "T""""" *°°'<' distinct white precipitate appears chl, . "I "'' '"'"*'•'"• « ^ -purity. A sligl.t turbiditro ;„ L": "V° "" '""' ^■°^'''-' ^^ ^'«-*- impurity to condemn the water It ^ "'* ^'""^'^^^ «»^«^-ient in salt, it may yield a precipitate '' ''''": '^''■"" ^ -"-« "^h precipitate and still be free f, oin pollution. MANUAL OF HYGIENE. 20S rapdly proceed, the water may be considered tpure ^^ "l of oxKh.aWo orgame matter may be estim- 'led b„ tV '."°°° Aange from pink t^ brown Tl,. '''""'""' '^ «>e rapidity of mpid decoloration T„a ol b J^e Tatter'Tb'"' ""' ^""^ "^ present, so that if thi, test i, T^IZ I' !u '""' "'*""^ »■■" potassinm iodide test (Sef r^Cj' t "^2 S*"" -'" ^^ w^^-:.;rrrrmt!^:rd'b;ih~^^^^^ the water or by approprLte tesU , fe^^encTor > V""™ °' ascertained by tests before n.entioned """"'= '«" "-^ 560. The practical deductions which may be drawn f,„ .u are exhibited in the following table tased „n ! . "^ **'*" "Manual of Practical Hygiene" and ml«d ''" ''^""-' qualitative test, given in" s worT " °' '° ""'^ '» "^ Ammonia. Nil. •Nil. Trace. Marked. Marked. Nitrites. Nil. Nil. Nil or trace. Nil or truce. Chlorine. Marked. Slight. Marked. Marked, Marked. Marked, Remarks. Pure, Good. Suspicious. If containing also sulphates phosphates and nitrates, may be a sliallow well contami- nated with urine. Contaminated with sewage. •By the test* (riven. 204 MANUAL OP HYGIENE. "ft- a few day. nitrates disaX«,f r""""" '"'° ""^'^ « ^«pe™ata„:tL • p'S" f ?," ™'" =; -.■«-. I.., and tke upon cavefulty testing the Aa", ' tl T'^T ""»-". -d found, -oma nitrite, or chlorides, it pTef that ^h 7 '~" °'- tWater sho.d he «tere,, and the' oX L^!. t ^j;!;:'-: l>ecome tainted, and doe, „„t „i,e 1? !, 'f '""■ " " ^oe, „„t »-.tb suspieion. It th„s pr„> „ n t „ ' °' "'" *"''''' >« ««»"'«l an.1 that o.idati„„ ha, trice,, pla^ T T"" ""^ "«» P--' t.tat,ve analysis should ,,, ,„„de * " ^^ " "=""'"' ^-an- »f ''« digestive funetio;"'; ^l?" TT ■'" *^ "^f^^' powders) containing lar„e„r„„o,r . ?"' *" ""■■"<"■ (<"■ baking <.;;^n.ag„esium salt^, .^ il e 03? f 'T-"'^""'' ^"'' """"d ^ other evidences of indigestion Z e T'"' *°"''' "»"^»- and *a,.rhl7 owing to ns, and the and found, ices of ani- usable, but «t ; if not, frequently 'ably yield t does not resence of Brand fit Jted, and regarded 1 present ful quan- ntaining •airment ' baking ■hloride, sea and 'asional is also ge per- rrhoea. water. ■ prac- ent in ipper, sturb- V ater MANUAL OF HYGIENE. 206 acquires impurities of this class chieHy from pipes and vessels in which it is contained (see Sees. 536 and 538). 566. Water contaminated by animal and vegetable substances may cause vomitmg, cramps, severe purging, diarrhea or dysentery. The propagation of infectious diseases by contaminated water has been considered in Chapter X. Impure water, though not containing the germs of contagion may, nevertheless, add to the malignancy of infectious diseases. Drinking-water polluted by tlie drainage from graveyards is very dangerous. Marsh waters may produce fevers and diseases of the liver and spleen. 567. Entozoa, or parasites, may be introduced into the system in dr..->king-water (see Sec. 442). Dr. Paterson, an eminent physician of Leith, noticed that certain families who drew water from a pubUc veil in a particular street were subject to intestinal worms; the families at the other end of the same street, who used the pure water which is supplied to Edinburgh and its vicinity, were free from the parasite. The suspected water came from a dirty pond or Jake in the neighborhood, and contained numerous vermiform animalculte. Many other instances are on record of these and other parasites being taken into the system in drinking-water. Small leeches introduced "in this way have been known to give rise to cough, nausea and spitting of blood. ° 568. For the purification of water four principles are employed • keeping the water in a state of rest for a sufficient length of time to allow of the settlhiff of impurities, the water being then drawn off from them ; the addition of substances which y^iWcsmse precipitation; the filtering, or straining out of impurities ; the exposure to influences^ or the addition of substances, which, by chemical action, will use up impurities in the formation of innocuous compounds. 569. Of the settling of turbid water we have common experience on the small scale, when wp allow a jug of muddy water, or water con- taining particles of sand or other suspended impurities, to stand till it becomes clear. Water companies often use large settling tanks or settling basins for the same purpose. Two or more tanks may be employed, especially if the constant plan of distribution is in operation. 570. Among substances used for removing impurities we may men- tion alum, salt^ of iron, tea, and other astringents, which entauale and •I n 206 MANUAL OF HYGIENE, if in soJution by an excj„7„l !, , •'^°'- ""= «>rl>o„ate held fnrthe,. addition oH 1 Iw aTd t" 7'" "^ ^"^'P'"''" l"^ ""^ o. carbonate,, or alu^ Pot^sk! „! "° °' ""«"^^'''"' "'"''rf''^ other like .ubstance, have be luTed r^'T'"' '"'"'■ *"'='""■ ""■' ohe„ica, „„ti„„ of eharcoa iretr °,r:t: S,f 7T^ "l prec.p.tat,o„ b, the addition of vario. s„bIL::t httlfelXel on the large scale : they may be ser- viceable as temporary expedie.its when such waters must for a time be "secl, as in travelling and camping. 571. Filtration, either alone or in conjunction with settling tanks, is the most common method of purifi- cation ; it may be practised either on the small or the large scale, '^and, gravel, powdered coke, char- coal and spongy iron are the sub- stances most commonly employed in tilters, whether large or small; and in small filters, sponge, wool, flannel, charcoal blocks, porous stones, mag- netic iron ore, and manganic oxide 572. Of domestic filters, one of the best is that shown in Pig 60 which is fully described in the note Fi,.60.-Do.„esticfl,tor:a,c,uppere..e .'^^"^P'^'^y^"^ ^^- I" One of the i^^iK.^^i^.r;~i?^ " "''^^ ^P«"^« - -ed an r^^v:^^r:::r:\:^£^r T'T;""'" ^"^-^h^^--'^ pi-te separ- ^^^^.^t!:^'^S^!nBS: T: *^^:;"fi':«-d from the filte.ed Zli^1^k:^r' ^"''^'^r''' ^--tehe' '"'^^'^'^ ^«'"g tl"-o"gh a little cavity offthefliteredwater ' •*''P*°'^'''«' *"e letter u in Fig. 60, and this c-5- - little cavity i« filUH! i,.. „ „_ m A small ta„k.,i,,er f,r househoW use ii .,o.IT^„: ^ MANUAL OF HYOFENE. 207 i bean of the rbonate held ated by the im chlorides 'larcoal, and natter; the Methods of e employed may he ser- expedients )r a time be '■ camping, ilone or in f tanks, is of purifi- sed either I'ge scale, oke, char- > the sub- iployed in nail ; and )], flannel, •nes, mas- lie oxide. 5, one of '■ Fig. 60, the note e of the used an te separ- ! filteied commu- [e cavity beneath md this 3nge. ition in Fig. 61. It will be seen that the mode of filtration is upward, the water passing up througl, tho filter when any tap is opened to draw off water for use. This tank is a settling tank as well, the heavier particles falling on the bottom of the tank, and not increasing the deposit on the filtering material. 574. Of small faucet fil- ters, to be screwed on to taps, there are several vari- eties. They are generally filled with quartz sand ; some- times charcoal is added. They are all made so as to be re- Fig. 6I.-Siiiall taiik-iilt. r, ui.v/ard filtration taking place wlien tajia aio opened. versed for the purpose of cleansing them. There is one kind in which this can be effected without unscrewing the filter: it consists of a uollow globe, inside of which is another globe filled with sand • this inner globe can l)e i-evolved and reversed by turning a handle maweailt covrrinrf itoite Pavlnif Level op Grovnd Fig. 62.— FUter with catch-pit and tank. 575. Filters on the large scale are used either alone or in connection with^settling-basins. In the latter case, after the subsidence of the 208 MANUAL OF HYGIENE. i*1i ■ sZUtl '^^''••"^S-b--' f-- -Inch it generally passes to a p Ian ,s shown, a oatch-pit being substituted for a settling-tank • tC filtratxon xs upwards in this n.tanco. More co.nmonlf we have in succession from above downward. Tiers of brick with interspaces are sometimes substituted for the stone interspaces 576 The chief benefit of filters is the removal of suspended impuri t es. Ihey exert very little influence on dissolved impurLes espZ v after they have been a short time in use, as the materi r re lobbed of any power they i ,essed in this direction. When they u allowed to rest long enough for the water to be entirely draS off and axr to enter in its place, the latter exerts an oxfdi.i:g effe J' and, for this reason, alternate or intennitfcent hltration is beuehc ' Germs of disease are not easily filtered out of water 577. Filtering materials should be frequently changed, otherwise hey become worse than useless: the organic n.atter which they have retained decomposes, and renders the water passing through them ties recommend persons not to use water fron. a filter, unless tliev know that care is taken to change its contents frequently 1^1^ and tl f : ' '"' ""'" ^' '''' *^P ^^^-' "-^ ^e changed o teT and the deeper layers at longer intervals. In one city in this Pro vince good water was rendered impure by filtering thiough a sand- bank containing constant accessions of organic matter; the filteri t basm, constructed at great cost, had to be abandoned ^ 578. A large filter with mechanism for washing the contained sand or other filtering agent, free from impurities, i" now " u e ,t t^ Kingston Asylum for the Insane, and many other pliro: Mi continent. It is called the Hyatt Filter (Fig. 63). It consists o wo compartments : the water is filtered (down^ard^tJ ouribe, of sand, or sand and charcoal in the lower compartment' Whe wat?T t "''?' ""' *'" ^"^^' '' '' ---d with a rush of water through pipes and allowed to fall through a body of water in HsIwrtTfTr* ' '''''■' ^?" ^" '-''''' "^ this'ompartmen: It IS allowed to fall down again through water in the lower compart- 1 the settling- y passes to a 3ation of tJiis ing-tank ; thn nly we have coarse stone h interspaces nded impuri- es, especially als are soon hen tliey are drained ofT, lizing effect, is beneficial. I, otherwise h they have rough them mie autliorj- unless they In filters ■nged often, in this Pro- igh a sand- he filterinfr ilned sand, use at the OS on this consists of ugh a bed It. When 1 a rush of f water in tipartment p compart- MANUAL OF HYGIENE. 209 ment and as soon as it settles the filtration may bo re-commenced Ihis cleansnag process occupies from ten to twenty minutes, and may be performed once in twenty-four hours, or more often if desired In the small cylinder to the lefb a plug of iron chloride and alum may be made to act to any desired extent on the water going to the filter thus causing a precipitation of impurities (as described in Sec 570) ■ these are then strained out by the filter bod. Fig. 63.— Hyatt Filter, 579. Boiling, and the use of contrivances for exposing it to air are other means for the purification of water. Boiling coagulates some of the organic matter, precipitates some of the impurities and drives ofi- others in gaseous form. Impurities may be oxidized by agitatin- the water or making it fall through air, imitating the action of waves and of natural rapids. 580. Freezing does not render impure water harmless: numerous instances are on record of outbreaks of disease from the ucc of ice obtained from impure sources. 210 MANUAL OP HYGIENE. 581. Drinking-water for schools should be kept perfectly free from any susp,.on of contannnation. In places where the water supl" lute contiol of thon>. In no case should schools be supplied fron. wells on ne,ghbonng grounds controlled by private individu^ We, " should be located at least ei-rhtv feet from +h« c v. i i, , "reater d,-<=fnM .„ t ., "^ ^® school-house, and a « eater distance from outhouses. The wall of the well for son.e d.sance below the ground should be impervious to surface leakZ and 1 should extend a foot above ground. Around the pump the.^ hou d be a dose, tight-Htting platform, covering the well.' X t' 1.0 adnutted through a tube placed beside the pump and extnd'Z some distance above the platform. The well should'be empC a d cleaned out at re,uent intervals, and the pun.p should be kept la A trough should be so placed as to carry the drippings from the pu.np a su heient distance away from the well. An open well w U <^o well with an ordinary pump-more perfect aeration of the ,.iuate test (.See. 5..>s) may occasionally be apj,lied, in order to detect any impun les that may exist. No cistern or tank for storii . wl sliould be allowed near the well. * Earthen vessels are less likely to become unfit for keeping water in an wooden or tin pails. Drinking cups should be of L^henwar china or glass, and should be kept clean. Care should be taken to ^0 that the gla.ing of earthenware is not of such a characte a^ to impart metallic impurities to the water; with this precaution, vessels glazed inside, so as to be smooth and easily cleaned, are ve y good Til y should be covered, and should have proper taps for drawing off water, so as not to permit dust to enter, as it often does in open ptik rn summer means should be taken to have tJie water cool ;ly free from ter supply ig have abso- pplied from uals. Wells ouse, and a 11 for some Lce leakag(>, pump there . Air may extendiujir iiptied and kept clean. 1 from the well, with M-able to a on of the ss-perman- r to detect ring water g water in thenware, taken to :;ter as to )n, vessels ery good, •awing off pen pails. CHAPTER XVII. THE eye: its 8TRUCTUKE— blind SPOT— FOnMATION OF IMAGFS ACCOMMODATION TO NEAR AND DISTANT OBJECTS-SINGLE VISION —NEAH-SIGIIT — FAR-SIGHT — CONFUSED SIGHT— SQUINTING- REMEDIES WHICH SHOULD BE APPLIED— CARE OF THE ETE8 — PROPER AND IMPROPER POSITIONS OF WIN- DOWS—PAPER AND TYPE— STATISTICS OF NEAR- SIGHT — INJURIOUS MODES OF READING OCCUPATIONS— COLOR BLINDNESS. 582. The eyeball (Fig. 64) is spherical and nearly an inch in diame- ter. It consists of transparent media contained within certain en veloping coats or tunics. 1 2 3— 4- 5- 6 1 7 I ,8 Bt 9 Fig. 64.— Aiitero-rosterior sectiDii of the eyeball. 583. The cornea and sclerotic constitute the outer coat. The cor- nea, or "glass of the eye"{i), a transparent membrane, is set. like a watch glass in its frame, into the anterior circular edge of the sclerotic membrane, or " white of the eye " (.). These membranes are of tough firm, and composite— largely fibrous— texture. ' 212 MANUAL OF HYGIENE. 584 The choroid coat (9) lies on the inner surface of the sclerotic' It consists of a network of blood vessels bound together hyloZJTn nectxve fssue the interspaces being filled with pi^^ent. 'xhe t Isl" of the choroKl bcoo.ne thicker in front fron. eert.ain fold, of the o ^ processes, and, extending on to the point of junction with th co nl tretoh across behind, and at sou.e distance fro™, the latter, Tnthe form of a curtain. ' ^"® 585. The iris (.), as this curtain is called, has in its centre a circu- lar oponmg, "the pupil" (see Fig. 58, p. 182). The pupil bee "s smaller when the eye is exposed to a bright light, and larger in a d.m hght. The contraction and dilatation of the 'pupi r^du to the action of muscular iibres in the iris, named respectively cteLar and .«. .a..., fibres. It will be seen from the description^en fal no hght can enter the eye except through the cornea' thatTone can pass beyond the p gment-laden curtain of the iris, except through" centra openmg, the pupil, and that by the action of fhe two se s o muscular fibres of the iris, the amount of light passing through tl^ pupil IS increased or diminished. ^ Another small but important set of nmscular fibres-the ciliary ^nuscle (3) IS situated at the point where the iris and ciliary pro Is^ .lom forming with the latter the ciliary ,ody. The mu JulLfi" of the ins and the ciliary muscle are involuntary, not being unde the influence of the will. (See Chap. XX.) 586. The retina, the third and remaining coat, lies upon the inner surface of the choroid. It consists of several layers : one of the mo t anterior IS the layer of optic nerve fibres, an expansion of th o3 ner^e (lo, a large nerve which, passing from the brain, and throulh he cavity or socket which contains the eye, pierces tl. sclerotic a^d choroid coats, its fibres then spreading out in a thin layer upon the ch roid; one of the outer layers is that of the rods and cols, con sisting of minute columns : this layer receives impressions and images and transmits them to the layer of nerve fibres, by which again they are conveyed to the brain. The spot where the optic nerve pierces the sclero ic, and from which its fibres branch, is destitute of the theTedna '""''' '"''^ '''"'' '' ^'^^ ^^""'^ '^'' ^^^'"^ 'P'' «^ 587. The phenomenon of the bhnd spot n.ay be shown by the follow- he sclerotic. >y loose con- The tissues P the ciliary the cornea, tter, in the tre a circu- )il becomes larger in a ire due to I7 circular given that ' none can hrough its Avo sets of rough the he ciliary processes liar fibres ing under the inner the most the optic through rotic and upon the mes, con- d images ain they 3 pierces e of the I spot of 3 foUow- MANUAL OF HYGIENE. 213 ing experiment: cover the right eye with the hand, and keep the vision of the left eye fixed upon B. Move the page back and for- A B wards, to and from the face, alimys keeping the left eye directed toward B: it will be found that at a distance anywhere in the neighborhood of six inches A will be visible; as the page recedes from the face, a point will be reached at which A will be lost from view, and at a still greater distance it will re-appear. The point at which it disappears will be that at which rays from A fall on the blind spot of the eye. 588. The humors of the eye are, proceeding from before backwards, (ct) the aqueous humor (Fig. 64, c) filling the anterior and posterior chambers, between the cornea and the iris, and between the iris and crystalline lens, respectively. Immediately behind the circular free edge of tha iris and the aqueous humor is (A) the (;ri/stulline lens (7), a body semi-fluid in intancy, and becoming pretty firm after the prime of life has been reached ; convex on both surfaces, but more so ante- riorly, it is enclosed in a capsule, and is held in its central position by the suspensory ligament. Behind the lens again we find {c) the vitreous himor (s), which forms about four-fifths of the bulk of the eye. The globe of the eye, which has been thus briefly described, is situated in the cavity of the orbit, together with the blood-vessels which supply it, the optic and other nerves, the lachrymal apparatus (by means of which its anterior surface is kept moist and free from dirt and other intruding particles), the muscles (Fig. 65) w^iich turn it in all directions towards various objects in the field of vision, and more or less fat. The muscles to which we have just referred, although they sometimes act under instinctive impulse, are yet of the voluntary class. The eyeball is lubricated, and at times closed in, by the eyelids, which protect it, and keep its surface moist by repeated momentary closure. 589. Formation of images on the retina.— The eye may be likened to a camera, the retina being its sensitive plate, on which are photo- graphed the images of objects by means of the rays of light reflected from them. These rays are imaginary straight lines proceeding from every point of a luminous or illuminated object. It is evident that 214 MANUAL OF HYOrKNFl, ZJi:'zz::^!^r --- '- - — ■ -n. ... itrai^ht. and, beyond eyelid. passes throiiLrh a piille • /> • r inL ^ * ' /'• "upeHor oblique. it, tbe internal st.ffil.uscl^-' c7°F ?''''","' = "' «''"'?''^ » iuuscie , c, Ji, / , muscles of the upper fall, it ,vn, be .„:„; rzt ir:,,?' t? "'"" '■°>' »- '-> of »,s if it be removed to a 3r li ^ " "^ ' ""'"''"' Fifr. 66. to5; 4, hi: i; when removed to the distance 2, it only ut at the cxtrfimifiAc r^f +i,^ „ "^ extremities of the screen, at £!, 2 receives the rays 2 and 4 are, of course, to MANIIAI. OF rrYOlEXK. 215 more nearly parallel than 1 and 5 are at the saiiK! portions of tlie screen at X. Rays entering the eye at a distance of twenty feet or more are, as regards vision, considered practically pai-allel. But even parallel rays-a uuiltiplicity of rays— from ditlei-ent points of the same object, intermingling, would produce a confused image, or really no image at all. 591. To bring to a focus at one point on the retina the pencil of rays passing through the pupil from an ol.jective point, is neces- sary for distinct \ ision. Each point of the object havi g its corresponding point on the retina, a distinct irnage will be formed. Kays passing n, «>'',"/-7^''"*.^'"" ".'"'"'"''' """■ "- ™^-^"'" '■-" .-i"t ^^7""'^ ^^"^ cornea, Which surface, are brought to a focus through the further refraction of the media, more especially of the crystalline lens. This is illustrated in the above diagram. b92. If a refracting apparatus of exactly the same power be used for near and distant objects, it is evident that if the rays from the distant object are brought to a focus on the retina, those from the near one will not be brought to a focus before reaching it ; on the other hand if those from the near one be brought to a focus on the retina, those from the distant one will be brought to a focus in front of it.' This will be made plain by a reference to Fig. 68, in which it wUl be seen -Z-=^A> ^^«;^^-—^^^«^r'\ showing that the same refractive power will not brinir to a fooug at the same point the rays from near and distant objcct^!^ that the rays from the point B, after passing through the ]pn« con- verge to meet at the point F, on tlie retina, wliilst those from the nearer point A do not meet where they strike the retina, but if 216 MANUAL OP HYGIENE. hi m •-'--'A' rig. 69.— Diagram showins; itiercasoof refraction by increased thickness of the lens. they could continue on through tho retina, would meet at a point A' behind It. In order that tho rays from A may be brought to a focus at the retina it will be necessary to increase the thickness and convexity of the lens, as shown by the dotted curved line in Fi" 69, indicating the wall of a lens so changed ; the dotted rays are the same as in the preceding ,. , , . , figure, and the uninterrupted Imes behind the lens indicate the converging rayg meeting on the retina at C, after passing through the more convex lens. 593. This process of accommodation, as it is termed, is exactly what occurs in the normal eye. When the eye is in a state of rest (A, Fig. 70) rays coming from a point distant twenty feet or more will be brought to a focus on the retina by the refractive power before alluded to. To bring to a focus rays from objects at a less distance, the ciliary muscles are brought into play : they cause a relaxation of the suspensory ligaments, and (B) a consequent increase in convexity of the lens, from its own elasticity, whilst at the same time the lens and free margin of the iris are pushed a little for- ward and the pupil becomes smaller. Now, the abuse of this little muscle by putting on it too much of this work, is one of the things we have to guard against. Before proceeding to draw hygienic deductions from the explanations just givep, let us consider ^ ^ 59*- How both eyes are directed so that the retina of each views the image of the same object, and the impression of one object is transmitted to the brain. This is accomplished by the action of the muscles which rotate the eyeball (Fig. 65), and which direct the axis of each eye towards the ol.jcct, so that the image may faU upon the limited portion of the retina which is most capable of i-eceivmg impressions, and on those portions of it which correspond, and will produce the same and, therefore, a single, impression. The Fig. 70. -Diagram illustrating: the me- chanism of "accom- modation." b a point A! t to a focus be necessary ckness and s, as shown line in Fig. .11 of a lens ;ed rays are s preceding interrupted ing on the is exactly ate of rest ant twenty us on the idcd to. 'J'o 5S distance, they cause s, and {B) lens, from 16 the lens little for- Now, the on it too 'e have to V hygienic ^^e^, let us the retina ion of one the action ich direct may fall apable of rrespond, on. The MANUAL OF HYGIExVE. 217 images in the eyes will be from slightly ditierent positions, thus producing the stereoscopic effect of bodies in relief, 595. The optical defects of most common occurrence are near-siffht, or myopia / far-sight, or hypermetropia ; and confused sight, or astig- matism. Greater accuracy of expression would be attained, and less room left for fallacious suppositions, if the first were called want of far-sight, and the second want of near-sight. 596. In near-sight, or myopia, the axis of the eye from before back- wards is so long that the rays, after passing through the lens, arrive at a focus before they reach the retina. In Fig. 71, the line a, e, c, g, represents the contour of the myopic eye; a, h, c, g, being that of the normal eye. Now, if the distance, g, b, is that at which parallel rays— those from a distance (see Sec. 590) — will be brought to a focus, then it is evident that they cannot come to a focus at the Fig. 71. -a, b, e, g, contour of tho distance of e, there being no natural o|c]tTkTtha?'o?the°hSermi °»eans provided for making the raya *'"'''''■ ™ore divergent and causing them to converge at e, nor for sufficiently reducing that distance. To over- come this defect, short-sighted persons are in the habit of half closing the lids, a practice which has given rise to the term " myopia." 597. In ''far sight," or hypermetropia, the shape of the eye is that indicated by the line a,f c, g, in Fig. 71. Here, by a process of reasoning similar to that employed in speaking of myopia, it will be Fig. 72.— Action of a concave lens on raya entering a myopic eye. seen that without an excessive convexity of the Ien.°. p.uch as cannot be obtained by the natural means described on the opposite page, the focus cannot be at the retina. When the attempt is made ;'l 218 MANUAL OP HYGIENE. an excessive strain is in many cases brought to bear on the ciliary muscles especially, and, to a certain extent, on the external muscles of the eyeball. 598. The artificial aid of lenses will remedy the difficulty in each of these cases. In myopia a concave lens will increase the divergence of rays, as shown in Fig. 72. In hypermetropia a convex lens will nicrease their convergence, as in Fig. 73. Fig. 73.-Act,ion of a convex leiis on rays entering a hypermetropic eye. 599. The condition of ''old sight,"' or presbyopia, is often classed indifferently with that of hypermetropia, both being relieved by convex lenses. But the former may occur in myopic as well as in hyperme- tropic eyes, and is owing to the fact that the lens being more dense and less elastic in old age, it will not become sufficiently convex and thickened under the action of the ciliary muscle, so that i-ays from a near point would come to a focus behind the retina. 600. Confused sight often arises from a defect called astigmatism in eyes in which the curvature of the cornea is abnormal, the fault being generally in its vertical plane. The pencils of rays' in planes at right angles to each other have different focal distances from the rornea ; those in one plane may come to a focus at the retina, and those in the other behind it, or the one in front and the other on it, or both in front (unevenly myopic), or both behind, or ^he one in front and the other liehind. 601. The result of astigmatism is to produce differences in the distinctness of equal lines which have different directions in relation to the horizontal and vertical planes. Any person with a normal eye may illustrate this for himself by looking at the letters on a page through a cylindrical rod, such as the glass mixer of the druggist. Holding the rod horizontally, he would have difficulty in distinguish- ing, for example, between n and u ; holding it vertically, the difficulty MANUAL OF HYGIENE. 219 1 the ciliary "iial muscles 'Y in each of > divergence Bx lens will "ten classed i by convex n hypernie- more dense convex and 'ays from a astigmatism tl, the fault s in planes s from the retina, and ther on it, <^he one in ces in the in relation aormal eye on a page 5 druggist, listinguish- e difficulty would be as between m and n. In order to overcome the difficulty, the astigmatic eye frequently and rapidly changes the accommodation (see Sec. 593), and hence is apt to become soon tired. 602. We may correct the defects of astigmatism by cylindrical lenses, or by a combination of these with glasses for myopia or hyper- metropia. It would be interesting to consider the various combina- tions, but we have not space ; our object being rather to draw the attention of people, especially of teachers, to these defects, and to point out how they may resort to rough preliminary tests, and refer for more precise details to an oculist, if found necessary. 603. A few test types will be found on the last page of this work. These are used for the purpose of ascertaining whether the sight is defective, the distances, in feet, at which the various lines should be read by the normal eye being indicated. 604. Weal<-sightedness, or asthenopia, consists in an inability for continuous use of the eyes without pain or other unpleasant symp- toms. This often arises from some of the defects already described and sometimes from weakness of the ocular muscles ; it should not be neglected, even if the sight seems excellent. 605. Squint, or strabismus, arising from irregular action of the muscles which move the eyeball, is frequently caused in the same way. We are principally concerned with its prevention ; but, inasmuch as its continuance is liable to give rise to disease of one of tlie eyes, to the gradual loss of vision in it, and to the consequent impairment of the usefulness of the scholar or other individual, it is a matter of importance from a hygienic point of view that the squint be remedied (whether caused as above indicated, or by convulsions, partial paralysis, or congenital defect), and that the operation of dividing the little muscle be not deferred indefinitely, 606. Care of the eyes in infancy.— It is well known to those who have to do with new-born infants, that they are very liable to " sore eyes"— inflammation of the conjunctiva, the soft, moist, lubricating (mucous) membrane which lines the lids and covers the front portion of the white of the eye. These affections are very apt to be neglected for some little time, under the supposition that it is not well to inter- fere with such little matters in childhood, and that they will rectify themselves. Great and permanent injury is frequently the result, 220 MANUAL OF HYGIENE. 'i i; Si* ft in 607. With regard to the exposure of the eyes to light, two opposite errors are committed. Some persons tlioughtlessly expose the eyes of children to a glare of light which they would after a time find trying to their own eyes ; nor is it sulliciently borne in mind that the eyes of the infant have not been accustomed to tlie light : the sensibility of the retina becomes impaired or desti-oyed by undue exposiu-e. The opposite error is that of placing coverings on the face to screen the eyes froia the light; wliilst one object is secured, fresh air is kept from the respiratory passages, with the injurious results described in Chap. III. Tlie means of screening the face or softening the rays of light coming to the child will be so obvious, that we need not do more than draw attention to the subject, 608. When irfants begin to look at near objects, they bring them, if thc-y can, very close to the eyes, the convergence of wliioh becomes so great that it is apt to induce squint. They should not be allowed to hold objects so very near to the eyes. 609. In children, even when past the age of infancy, inflammation oi tiie iids, purulent ophthalmia and ulcerations of the cornea are frequent, and they are liable to be overlooked and neglected, especially if tiit> ohikl has not arrived at an age to use the eyes for purposes of systematic study or woi-k. The remarks which ha\ e been made regarding the folly of such a course are equally applicable here. 610. That purulent ophthalmia is communicable must not be for- gotten. The greatest care should be taken to guard against such connmniication ; each child should have his own towel, basin, etc. and use no otlier. In some institutions where the disease may spread no basins are provided, water being used from a running tap. When only one eye is affected, it should be remembered that the discharge may inoculate the other eye, if care be not taken. The child has now grown to that age when he will instinctively protect himself from the glare of intense light; but he, as well as the adult, may still expose the eye unnecessarily, from not having thought sufficiently on the subject ; the amount of inunediate annoy- ance may be less, but continuous, and injurious on account of its contir'ianco. 611. If a flood of light, or too bright a light, be allowed to fall upon tlie retina, the excessive stimulus impairs its sensibility; and tbe MANUAL OF HYGIENE. t, two opposite ose the eyes of me find trying that the eyes the sensibility ixposiu'e. The e to screen the sh air is kept s described in ng the rays of 5 need not do bring them, if ch becomes so be allowed to inflammation le cornea are ted, especially for purposes e Ijcen made le here. i not be for- against sucii 1, basin, etc., 16 may spread : tap. When the discharge instinctively e, as well as 1 not having idiate annoy- ccount of its I to fall upon tyj a ad tbe 221 diffuse light also interferes with the impression which would otherwise be produced from an object we wish to see. When we want to look at an object we should keep the optic caTnera-the interior of the eve -comparatively free from direct light, and reserve it for the reception of rays from the ol.ject or objects to be looked at, and these should be sufficiently illuminated to produce the desired effect of distinct vision m such a case, then, it is obvious that the respective positions of the eye and the light should be such that the light shall fall on the object and that the eye shall be shaded. If the object is one which will reflect rays very brightly, the effect nuiy be sonievvhat similar to that produced by direct light in too great quantity or too bright. Again, If light tails from opposite sources on an object, we may liave confusion trora reflection of tlie "cross-lights.'' 612. We often find scholars" facing the windows, a flood of li.ht entering their eyes, the teacher thrown into the shade between thlm and the windows, the blackboard placed somewhere in the neiglibor- hood of the teacher's lesk, sometin.es l>etween the windows ; or the blackboard may be a bright reflecting surface, and so placed that a dazzling reflection reaches the eyes of the scholars. Let us now watch the atter at their various employments. Some have their bo'.ks flat on the desks, so that the light may fall on the page, and their heads are ben forward so as to shade their eyes from the light. This positir.n is very bad both as regards respiration and the condition of the spinal column, brain and nerves. The free return of blood from the brain and from the eye itself, is interfered svith. Others are turned half around in their seats, or have the upper portions of their bodies twisted mto the same position, having found by gradual experiencelhe beneflt to be derived from a side light. Others are straining the muscles of the eye and eyebrows, and are suffering from the strain of the involuntary muscles of the ins, in the eflbrt to exclude the excessive amount of light and receive the impression of the rays from the dindy- illummated face of the teacher or surface cf the blackboard. The effects of this constant or oft-repeated strain, and of the constrained postures just described, are pain in the eyes, headache, dizziness, flushed face, pam in the back and shoulders, and other symptoms of weariness or uneasiness. 613. In another room the hght falls from behind. For reading, the Ms If. 222 MANUAL OF HYGIENE. pupil may make this light answer by holding up his book, at the expense of obscuring the teacher's face, or his own face from the teacher ; in writing, ciphering, drawing, and other like occupations, his own shadow will seriously interfere and cause him to stoop over and strain liis eyes to see. 614. In rooms in which light comes In from the right side the shadow of the liand falls upon the portion of the page at which the pupil is looking. We have already spoken of the bad results of cross light.'!, and yet many of our schoolrooms are lighted in this way. The best liglit is that coming from tlie left side, and, if anything, a little in front. 615. The light should come somewhat from above ; the bad results of any deviation from the proper horizontal direction, especially if that deviation is toward the front, are somewhat lessened thereby. Light from below is undesirable. For this reason blinds have been devised to cover the window from below upwards. Frosted glass in front is dazzling and objectionable. 616. In regard to artificial light the same remarks hold good. It is also very apt to be deficient in amount, and not evenly and generally distributed— those near to it being dazzled, and those at a distance struggling with too little light. The use of suitable reflectc s is to be recommended ; and these reflectors may assist ventilation, by being made funnel-shaped and with a tube leading up from the apex of the funnel, as recommended on page 50. 617. A great increase in the number of cases of myopia seems to have been caused by the amount of close application of the visual organs in modern times. This is well marked during school life. Some years ago about ten thousand school children were tested by Dr. Cohn, of Breslau, with the following results as regards the num- ber of them who were found to be myopic : In the Elementary grade 6.7 per cent. II Intermeiiiate h io.3 .1 High School II j9_7 ^^ II Gymnasium n . . 26.2 „ 618. Headache, aching of the eyes, dizziness, and other ailments are caused by undue application to near objects. This is especially the case in childrea xrith hypermetropic eyes. Here the difficulty of is book, at the I face from the ke occupations, n to stoop over side tlie shadow lich the pupil is of cross lights, way. The best ything, a little the bad results n, especially if 5sened thereby, inds have been rosted glass in )ld good. It is ' and generally } at a distance sflect* s is to be itiou, by being the apex of the yopia seems to I of the visual ng school life, were tested by ;ards the num- >er cent. ather ailments s is especially le difficulty of MANUAL OF HYGIENE. 223 t"e other ^ i' '"" " ""^' ^"^'^'•' ^^"^ - *h-« -d some of the other cases the strain upon the ciliary muscles is such that they sometx^es become weakened, and work has to be suspended Some^^mes, too. a condition of permanent contraction called slalt th. accornmodat^on results, impairing distant vision, and ca^ni apparent myopxa print, etc., requiring to be held close to the eyes the n •^'"P^'?." '""*"^' *"'' '•""'•*'°" *»•• '"y«P'«^ - -count of the person affected not seeing well or distinctly, and bringing tl^ c^ndit'n """ " """"' " *'' ''■''' '■"^^^ '' *^« --h-i-1 also. The accommodation and convergence of the eyes are associated mov ents : ,,hen the muscles of accommodation are called ^toXy tho e of convergence,-which direct the axes of the eyeballs inwLs contracted, and a convergent squint is produced. This occurs most commonly with those who are naturally hypermetropic. S metimef however, the stram on them is so .reat that they give way und r t and, becommg weakened, produce the opposite condition to that as' descnbed-a divergent squint. We have before remarked that when sorabismus, or squinting, occurs, one of the eyes is apt to belme diseased and lo.e the power of vision. It should, therefore be remedied without loss of time bv snectaolp, n. if '"""^^^ore, be operation. ^ spectacles, or, if necessary, by 621. Inflammatory affections of the various tissues of the eye are dlre^i:: ^^r ^^-t-- ^^P^-^-. -peciaHy when 0^^ blotthoTeye. ' '^ "^" '' '^""^^ ^^ ^^^ ^^^^^^ "<^« -^ 622. The exercises in school should be frequently changed, so as not to keep scho ars too long at close application of the eyeslblackboard exercise, and object teaching being interspersed with reading, writin! and ciphering. *" "^'^''"'g 623. G^od clear type, not too small, should be employed for school books The paper should be good, and not so thinVto It t" print thruugli on the opposite side, and not too bright and ..lossy In ^reading and writing, the book or paper should be slanti^gVin ^ii 224 MANUAL OF HYGIENE. reading, the angle should be about 45° ; in writing, this angle will be too great for mechanical convenience. Children should e'l.gage in out-door games, and games not requiring near-sight. 624. In no case should the use of spectacles be deferred when they give relief. This remark will apply to presbyopic and far-sighted people, as well as to others. Myopic children, even after the defect has been remedied by spectacles, will often, from habit, still bring objects looked at very close to the eyes. This must not be allowed or the myopia will become worse, on account of the muscular con- traction induced by the convergence — the two actions being asso- ciated. 625. Reading by a dim light is to be avoided. For this reason we should have plenty of window space, the proportion to floor space recommended varying from foot per foot to one foot in three. Strain- ing the eyes at twilight is a false economy. A flickering light is also to be avoided. Reading in the recumbent posture taxes the eyes unduly, and is otherwise injurious. Reading in a vehicle which has a jerky motion is bad for the eyes, as it causes a vibration of the page, requiring constant change in the position and accommodation of the eyes. 626. In the choice of a calling the condition of the eyes should be taken into consideration. There t^re some occupations more suitable than others, according as the eyes are myopic or hypermetropic. Then, again, the condition of the eyelids in some persons would render it advisable that they should not engage in occupations in which dust or metallic particles abound. Conditions of general hygiene which affect the eyes are taken up in their proper places. 627. The glare of snow, light-colored soils, water and direct light may be counteracted by spectacles, blue-tinted, or of the color called London smoke. The blue-tinted glass may be also used in connection with artificial light. Blinds, screens, or reflectors of suitable color may also be employed. 628. Quack applications to the eyes should be avoided. Plain water is the proper fluid for bathing the eyes ; nothing, however, is to be gained in the case of the healthy eye by forcing it open and bathing it. If. however, there is anv disohar^'e or an^' foreio-n gub- stance in the eye, a little tepid water may be allowed to run from a lis angle will be ould engage in Urred when they and far-sighted after the defect abit, still bring not be allowed ) muscular con- ons being asso- this reason we . to floor space [ three. Strain- ing light is also taxes the eyes hide which has ibratioii of the ^ommodation of eyes should be s more suitable hypermetropic, persons would occupations in 3ns of general •per places. ind direct light ;he color called i in connection E suitable color voided. Plain ng, however, is ig it open and )y foreign sub- to run from a MANUAL OF HYGIENE. 225 sponge into it, the lids being hold open. If any further medication or other treatment is required, medical advice should be sought. 629. Color-blindness is a defect which, if looked upon in its hygienic aspect, is not any more apt to cause mischief to those P,fiected by it than to others. The colors which blend to form white light are red, green, and violet. By placing these colors on alternate sections of a circular card, and revolving the card rapidly, it will appear white. For the perception of each of these colors there are certain elements in the retina of the normal eye : the absence of one of these sets of elements will produce blindness for the particular color for the perception of which it would be adapted. 630. The results of this defect are serious in connection with the signal lights of railroads and steamboats. It is found to be more common than was formerly supposed. It is also found that some of the tests formerly made are not to be relied upon. The persons experimented upon could distinguish the signals by means of the greater or less brilliancy of the light transmitted, or from the shape ot the signal or some other peculiarity. A frame with skeins of various colors intermingled, each having a number attached, which number is concealed from view, is now used for testing, measuring and indicating the defect. The colors regarding which there is the niost serious difficulty are red and green. Statistics show the number of color-bhnd persons to be 4 per cent, among males, and 0.4 per cent among females. Although true color-blindness is congenital and incurable it is desirable that in children not really color-blind the facul y of distinguishing colors should be cultivated and improved, and not allowed to faU into disuse and to become impaired m CHAPTEE XVIII. TIIR ear: its structure — EFFECTS OF COLO DRAUGHTS — UNDUE EXPOSURE — FOREIGN BODIES IN THE EAR — BOXING THE EAKS— IMPORTANCE OF ATTENTION TO DEFECTS OF HEARING. 631. The ear is composed of three parts— the external, middle and internal ear (Fig. 74). The external ear consists of an outer project- ing part, called the auricle or pinna, and a canal, called. the externa! aiulitory canal. 632. In the auditory canal (7i) are found numerous hairs and small glands. The latter secrete a peculiar substance known as the ear-wax. At rhe inner extremity of the auditory canal there is a thin mernbi lie called the tjimj)anicme'iiihrnne,ovdv\x\n- head, which divides the ex- ternal from the middk- ear ; another partition, partly membranous and partly osse- ous or bony, separates the middle from the internal ear. 633. The middle ear, or tympanum (C), is situated in the bone of the skull called the temporal bone. It com- municates with the pharynx by a long and very small canal (G), called the Eustachian tube. Through this tube air is ad- mitted from the pharynx into the middle ear. The tympanic mem- brane is convex on its internal surface. Attached to the drum-head is the handle or long proeess of a small bone, called the malleus or hammer. There are two other bones in the middle ear, the incus or Fiif. 74.— The left car. A, vestibule; B, --.uditory canal; C, middle car; D, semi-circular canals; JH, cochlea ; G, Eustachian tube. MANUAL OF HYOIENE. 227 lUGIITS — UNDUE THE EAHS — EARING. •nal, middle and n outer project- led the externa! hairs and small 1 as the ear-wax. 3r extremity of ' canal there is )i lie called the r.iftrroi^', or drum- divides the ex- the middle ear ; ,1'tition, partly and partly osse- ', separates the the internal ear. middle ear^ or 7), is situated in the skull called I bone. It com- ith the pharynx and very small tube air is ad- i tympanic mem- I the drum-head 1 the malleus or !ar, the incitu or anvd, and the stapes or stirrup. These three bones or ossicles are connected together, and fo.m a chain of bones extending fron. the tympanic membrane to an opening leading into th. internal ear, called thejeneslra ot-alis. The foot of the stapes rests on the thin menibrrne covering the fenestra ovalis. 634. The internal ear, or labyrinth, is composed of the vestibule M ) senu-cHCular canals (/>), and cochlea {E). The vestibule is a chamber which communicates with both the semi-circular canals and the cochlea. On its external wall is the fenestra ovalis, closed by the base of the stapes. The semi-circular canah are three in numl>er • two are placed vertically and one hori/ontally and at right angles to the others. The corhlea is a spiral-shaped chamber formed like a snail shell. Ihese bony cavities of the internal ..ir are filled with mem- branous structures and fl dd. In the labyrinth or internal ear as a whole the vibrations of sound are brought into contact with the auditor If nerve. 635. The tympanic membrane is easily thrown into vibrations by sounds in the air, especially on account of its peculiar funnel shape. Every motion of it is transmitted through the chain of bones and through the membrane of the fenestra ovalis, (to which the stapes is attached), to the fluids within the internal ear. 636. The auditory nerve is distributed to various parts of the vesti- bule cochlea and semicircular canals, where it receives impressions of sounds conveyed to it through the textures of the ear. These impres sions are thus conveyed to the brain. The delicate parts within the internal ear are protected from injury by the lirm bony structure in which they are encased, and which forms part of the skull The form and direction of the external auditory canal are well suited to con- duct the sonorous vibrations to the tympanic membrane. This mem- brane IS provided with small muscles Mhich regulate its tension so as to adjust it to the quality and intensity of sounds. The Eustachian tube, by admitting air to the middle ear, preserves the equilibrium of pressure between the external air and that contained within the middle ear. 637. By cultivation and habit the organs of hearing are educated to perceive the direction, quality, intensity, and other characteristics of sound. Tnis is seen in a remarkable manner in the case of conduc- 228 MANUAL OF HVQIENE. Ij !' ftS" S tors of orchestral perforinaucos, wlio can distinguish the slightest variations from proper time or tune among a large number of musical instruments sounding sinudtan(!ously. The well-known acuteness of hearing possessed by blind persons is also an instance of the same fact. 638. The organs of hearing should not be exposed to cold draughts. Permitting children to sit ncur an open window, whnre tiicv are exposed to a cold wind blowing upon the head, is wrong. Inflamma- tion of the middle ear fie(pu'ntly results from exposure of this kind — very many of the ear-aches of young children between the ages of four and ten years are due to sucli inflammation. Frequently these inflammations terminate with no other serious symptom than pain. But all have not such a fortunate ending : the fluid poured out as a product of the first stage of the inflammation may assume the charac- ter of pus or matter. 639. This may result in a perforation of the tympanic membrane. In many instances an impairment or loss of hearing, a chronic and generally offensive discharge from the affected ear, or even fatal disease of the adjacent organs, may be produced by inflammation of the middle ear. The latter, whether due to the causes just mentioned or to measles or scarlet fever, should be treate portion by a wrench which should be in the possession of the teacher or caretaker, so that the pupils may not meddle with them. U 236 MANUAL OF HYGIENE. hit' i< i' .1 "I Ik 653. The pupils are measured every six months in Prance and some other European countries, and seats and desks of suitable pro- portions are assigned to them. Dr. Guillaume states that the seats at the Ecole Premiere were altered in this way with excellent results. Rules have been laid down, and tables prepared, giving measurements to guide teachers in regulating seats for children. A test of these tables shows that in some instances they are not strictly correct, nor are they suitable for practical application, owing to varied propor- tionate developments of different pupils. Movable seats and desks should in all cases be provided. 654. Continuance too long in one position causes fatigue of a certain set of muscles, and* these become relaxed. Thus there may be an unnatural and unhealthy position assumed, which may become habitual. When the muscles which should support the spinal column become tired they relax, the burden of supporting the superincumbent weight of the head and shoulders then falls upon the lig. ments, which are not able for the work imposed upon them, and the conditions described in Sec. 651 are gradually produced. To prevent these results pupils must be advised and encouraged to avoid injurious positions and postures, and the relaxations and exercises recommended in the next succeeding chapter should be carried out. ' 655. Blinds or curtains should be provided for all the windows. These should be so arranged as to enable the teacher to regulate the supply of light properly, as circumstances require. (See Sec. 615.) 656. Blackboards of a dark green color, and having a dead surface which does not reflect a glare of light, are to be preferred. There are obvious advantages in having blackboards which may be moved about and set in any required position. 657. Drinking vessels should be provided and attended to, as de- scribed in Sees. 572 and 581. There should be a hook at a convenient place for holding the cup when not in use. A supply of water to be used in case of fire is necessary, especially in buildings of more than one storey. 658. A thermometer should be kept in each room, and the tempera- ture accurately noted. (See Sees. 156 and 158.) 659. Cars of fur.niture is regulated by instructions of the Education Department. Rooms should be swept at night, and dusted in the in France and of suitable pro- 3 that the seats ixcellent results, ig measurements A test of these ctly correct, nor varied propor- seats and desks igue of a certain ere may be an >ecome habitual, column become cumbent weight lents, which are litions described 16 results pupils s positions and ded in the next 1 the windows, to regulate the lee Sec. 615.) a dead surface red. There are be moved about jnded to, as de- at a convenient of water to be s of more than MANUAL OF HYGIENE. 237 morning. Desks and seats should be carefully dusted eveiy day They should be washed frequently, in order to remove all dirt adhering to the wood. 660. School-rooms should be made cheerful and attractive. Flowers pictures of eminent men or places prominent in history, are useful and attractive in a school-room. The cultivation of flowers, trees and shrubberj on the grounds tends to educate and refine the tastes of pupils, who should bo taught to protect and admire all that contri- butes to the beauty and comfort of the school-room and surrounding grounds. '!! '4 J d the tempera- ' the Education dusted in the w CHAPTEE XX. PHYSICAL exercise: voluntary and involuntary muscles — STRUC- TURE OF MUSCLE — WALKING — LEAPING — RU1,NING — ROWING — FENCING — HAND-BALL — RIDING — IRRATIONAL ATHLETICS IN- JURIOUS TO TUB HEART, LUNGS AND LIMBS — GYMNASTICS AND CALISTHENICS — RECESSES — SINGING — KINDER- GARTEN EXERCISES. m 661. Exercise is a subject of vital importance, especially to those who follow sedentary pursuits. The remarks it this chapter are more particularly addressed to students, who, in order to obtain mental improvement, often forget to pay attention to the wants of the body. As usually employed, the term exercise refers to the action of the voluntary muscles. Muscles are classed by physiologists under two heads, the voluntary and involuntary. 662. Voluntary muscles are those which execute movements under the influence of the will, as the muscles of the head, limbs, trunk, etc. Thus, in Fig. 81 we see that the position of the right arm is repre- sented as produced by the action of the will on certain voluntary muscles, viz., the biceps (b), the two pectoral muscles (pp), and the deltoid (d). Voluntary muscles antagonize each oth'-r in almost all parts of the body. The extremities have flexors ami extensors, pronat/ors and supinators, adductors and abductors, rotators inwards and rotators outwards. When the muscles of one side of the face are paralyzed, the muscles of the opposite side draw the features towards their side. When one-half of the tongue is paralyzed, the point of it is seen, when protruded, to be forced towards the paralyzed side by the action of the muscles of the opposite side. Hence it appears that these muscles are, when in their healthy state, always in a condition of slight contraction, and that the state of inaction of the different parts of our bodies does not indicate an absolutely relaxed pondition of the muscles, but rather that the different groups of MANUAL OF HYGIENE. 289 [USCtES — STRUC- } — BOWING — ILETICS IN- MNASTICS INDER- lecially to those chapter are more ) obtain mental 3 wants of the to the action of siologists under lovements under imbs, trunk, etc. it arm is repre- irtain voluntary 's {pp), and the ^r in almost all and extensors, rotators inwards side of the face Lw the features s paralyzed, the ds the paralyzed side. Hence it state, always in ■ inaction of the solutely relaxed irent groups of muscles antagonize and balance each other, and tliat when the posi- tion of a part is changed from the medium state of apparent rest, one or more of the muscles, already in a state of antagonistic action, are merely thrown into more powerful contraction. 663. By muscular contraction is understood the exertion of the power possessed by the muscles of shortening themselves, or of con- tracting, to produce motion. 664. Involuntary muscles, as the heart, fleshy 6bres of the intestines, etc., do not require an effort of the will for the exercise of their func- tions, and their continued action does not caus. any sensation of uneasmess. The movements of these muscles are pe.-formed uncon- sciously, and yet perfectly, without experience or education of the mind, through the action of certain special stimuli 665. Muscular fibre (Fig. 79) is a nan.e given to the filaiuents, which by their union form the muscles. This fibre is flat, soft, downy, linear, and somewhat elastic. It is itself composed of a considerable number of tibrils, similar to each other, and subdividing almost od infinitum. The ultimate fibrils seem to be tubular. There are two forms of nmscular tissue, the striped and the unstriped. In the former thi fibres have little transverse markings or stricv.; in the latter they are plain. Muscles composed of striped fibres are, with a few exceptions, of the voluntary class, and minister to voluntary motion and the functions of animal life. The unstriped are, per- haps, always involuntary, and minister to the functions of vegetative life or simple existence. The color of the muscular fibres is red in man and most of the higher animals. The muscular fibre shown in Fie 79 is of the striped variety, 666. A voluntary muscle consists of a greater or less number of these fibrils united in bundles, approximated to each other, and form- ing a distinct mass of very variable size and shape, the extremities of which are attached to bones by means of tendons. In this are included cellular tissue, vessels and nerves. The cellular tissue serves to unite together the fibres, and it also forms to each muscle an external envelope, which unites it to the neighboring parts and Muscular fibre. 240 MANUAL OF HYUIENE. 'i Mf admits of its motion. Arteries proceed to tlie muscles from neigh- boring trunks, and are always large in proportion to the bulk of the muscle. Nerves follow the same course in the muscles as the arteries. Nerves proceed from the brain and penetrate to the fleshy tissue with the vessels, with which they are closely united. After they have entered the muscles they divide antl .ubdivide until they are lost sight of. Although wo do not know the exact changes going on in the muscles, there is no doubt that with constant, regular exercise a muscle enlarges, becomes thicker and heavier, contains more solid matter, and has, in fact, gained in nitrogen. This process may bo slow, but it is certain, and nitrogen must either be supplied by increased food or be taken from other parts. 667. Rational athletics tend not only to improve the health, but, if systematically carried out, along with a regulated diet and increased action of the eliminating Organs, they produce the highest type of healthy and vigorous living. We shall now proceed to indicate a few of tliose exercises which may be included under this term. They may be either active or passive. 668. Walking on a level surface is the gentlest form of active exer- cise ; the muscles of the extremities, trunk, abdomen and neck are thrown into moderate action, which does not produce fatigue, if the pace is not too rapid and if no weight is carried. In ascendinj^ or descending a hill, the motion is more violent, and the shaking of the body is greater, so that fatigue is more rapidly induced. The amount of walking required by different persons varies greatly. Dr. Parkes recommended for an adult a walk of nine miles a day, which would be equivalent to 150 tons lifted one foot. But as there is ranch exertion taken in the ordinary business of life, this amount may be in many cases reduced. It is not possible to lay down rules for all cases, but a walk of four to six miles a day seems to agree with the constitution of the majority of men ; they eat and sleep better, and all the functions of their systems are performed with greater satisfaction when that amount of exercise is taken daily. 669. Leaping or jumping jars the body violently. It is only suited to the period of youth, when the cartilages are soft, and can, by their elasticity, moderate ihf \'iolence of the sh.aking. Tn .ndults and old people, in whom the cartilages have become indurated and have lost. L MANUAL OP HYGIENE. 241 eles from neigh- the bulk of the 3 as tlie arteries, le lieshy tissue id. After they until they are langes going on regular exercise ;ains more solid process may be be .supplied by 8 health, but, if it and increased highest type of indicate a few erin. They may n of active exer- n and neck are e fatigue, if the In ascending [ the shaking of J induced. The varies greatly, ne miles a day, ! foot. But as less of life, this possible to lay lies a day seems a; they eat and 3 performed with taken daily. It is only suited md can, by their s .adult.s and old d and have lost, to a certain extent, their elasticity, it is highly improper, and is frequently followed by serious consequences, 670. In running there is a succession of leaps, which quickly pro- duces fatigue and excites the lungs and lieart violently. It is not suited to the later periods of life. Games such as football, lacrosse baseball and cricket come under the head of running, and the suit^ ability of any of them to certain periods of life is to be measured by the same standa.-d which has been applied to it. When properly played, they are useful forms of exercise for healthy boys or youn- men. ^ " 671. Rowing is an excellent athletic exercise, and one which for- tunately, can be very generally inaulged in by the people of' this country. It is suitable to all periods of life, from childhood to old age. It IS of great value to young men, particularly those of seden- tary habits, since it tends to develop the muscles of the chest, and the exertion, without being necessarily severe, causes a healthful action in nearly all the muscles of the body and extremities. 672. Fencing also develops all the muscles of the trunk and of the upper and lower extremities. It also necessitates great activity of the mind and quickness of vision, in order to resist successfully an opponent's attack. The foil should be used with the left hand as well as the right, so as to develop both sides of the body equally 673. Fives, or handball, is a very useful form of active exercise quite free from objection on the score of roughness, and calculated to call into activity all the muscles of the trunk and both upper and lower extremities. It also calls for considerable quickness of vision, and IS altogether, when well played, a very attractive game for both the players and the spectators. In some large schools it forms the principal source of amusement. This game is peculiarly adapted to the wants of hose who live in towns. It only requires three walls and a limited space, needs no grass, and affords most bracing and exhilarating exercise in a short space of time. The full-sized court in which it is played consists of a cemented, paved or neatly boarded floor, about 30 feet long by 16 feet wide, a back wall 16 feet square and two side walls beginning at 16 feet high at the one end and gradually oinking to about 5 feet at the other. A small hard ball is used to play with, and the object is to strike the baU with the palm -.V f*»5j I W 242 MANUAL OF IIYQIENE. i! 1 ml I'M N i of the hr d against tho wall, so diat it bounds back on the floor of the court for Mio opponents to strike in a similar way. By using the side walls tlio ball is made to pass througli many angles before it reaches the floor, and, in consequence, its course is more difficult to follow. Eitiicr hand is used equally, and thus this exercise has the groat advantage; of being uniform, and bringing both sides of the trunk and chest into action. In this country, owing to the cheapness of timber, a ti\ cs-court could be put up at but little expense. 674. Horse-back exercise is of all the forms of passive exercise the most useful ; and it is not a purely passive exercise, as a considci il)lo amount of muscular exertion is noccssary to retain one's seat when the motion is rapid. 675. Riding in a carriage and sailing are forms of passive exercise which are conducive to health, on account of the change of air and the constant succession of novelties. Unfortunately, sailing is, in some cases, attended by the disagreeable sensations included under the name of sea-sickness ; but, in spit(» of this drawback, it is very bene- ficial for invalids, and is often the most valuable remedial agent that can be employed during convalescence. 676. Irrational athletics include all those exercises which cause disease or injury to the body or any portion of it. As the true aim of all athletic pursuits is to increase muscular power, and thereby improve the general condition of the body, only those forms of exer- cise should be practised which accomplish the desired object with the least possible injury to the body. As an example of athletic sports unwise from a sanitary point of view, take boat-racing. A perfectly sound inan may train for boat-races, and may win in a good many, without injury, but the strain upon his heart and lungs during the race is considerable. Not that the handling of the oar is heavy work, but the velocity of the repeated acts which constitute rowing at racing speed has to be considered in this estimate. For instance, in the Oxford boat-races, rowing at racing speed ( = 1 mile in 7 minutes), in an Oxford eight-oar, or 18.56 foot-tons in 7 minutes, is not appar- ently very hard work, but it is very severe for the time, as its effect is great on the circulatory system. 677. Heart disease may sometimes result frorrs over-exertinn in athletic sports, though we think the cases are few in which it ,.?*; \n the floor of ay. By using Y angles before 3 more difficult xercise lias the li sides of the the cheapness :)ense. ve exercise the a considei iltle sues seat when )assive exercise nge of air and •, sailing is, in uded under the it is very bene- ;dial agent that iS which cause \s the true aim !r, and thereby forms cf exer- object with the athletic sports g. A perfectly 1 a good many, ings during the e oar is heavy nstitute rowing For instance, in le in 7 minutes), IS, is not appar- me, as its effect )ver-exertion in w in which it MANUAL OF HYOIKNK. 24S can be traced to physical exercises alone. Instances are. however on record showing that severe labor, as in the case of soldiers who have done heavy marching during a campaign, has ,uus(.d enlarge- ment and dilatation of the heart.-(Flint.) The san.e author also states that " rupture of the valves or tendinous cords of tlie heart sometimes results from the violence of the heart's action, without any previous structural change." Hence i' ;.■ reasonable to infer that continued muscular stnun, involvir^ grea. .peed, either in walking, rowing, or running, tends to pr< duce a sihole eidargement of the heart muscle, and, in other cases, it causes damage to the valves and tendinous cords of the heart, w} h h: subsequently fol- lowed by enlargement and dilatation. Figure 80 exhibits a cross section of the Jieart, with the valves which guard its ori- fices, jn a healthy licart, such as is here •shown, tliese valves open, to permit the blood to flow in one direction, and close with great accuracy, to prevent it tVom returning. Injury to the valves or to the tendinous cords which hold the mi- tral and tricuspid valves in position, prevents the valves from closing with accuracy, and interferes with the proper onward current of the blood, by per- mitting some of it to flow backwards. 678. Emphysema, or excessive and permanent dilatation of the air-cells, may be produced by prolonged forcible eflbrts of expiration, as in long-continued exertion at lifting or pulling, the elasticity of the lungs being diminished. This condition is characterized by bre.athleR5:nos^s on exertion. 679. Fracture of the collar-bone, or of the bones of the extremities, Fi-f. so. -Cross secti, semilunar valv h of the aorta. If J i T'l II li 244 MANUAL OF nYCxIENE. occurs occasionally during football matches. Lacrosse matches appear to be fertile in contributions to surgery ; hut these, and other athletic games, can be skilfully played without any of the contestants sustain- ing injury, if fair play is insisted on. Looking at the subject from another standpoint, it is consoling to those who are fond of regular athletic sports, to learn from the head-master of an English public school, with an attendance of five hundred scholars, that " quite as many sprains, bruises and cuts arise from skylarking as from all the organized games put together." The head-master of another English school, with nearly as many scholars as the preceding one, says : "The football accidents, though apparently numerous, are really trifling. On an average, 500 boys play two games a week for ten weeks, giving a total of 10,000 games of individuals ; the number of broken collar- bones and arms may amount to two or three per annum. A broken leg or a serious brain concussion may occur once in ten years, i.e., once in 100,000 games. Accidents to knees are most troublesome. There have been no accidents, except one, which I would consider really serious. This was a blow on the head, which was neglected, and it brought on serious inflammation, and required more than a year's rest." These opinions, coming from such important sources, are very valuable. 680. Gymnastics, as a general rule, should be undertaken systemati- cally, in a regular gymnasium, under an instructor's eye. If boys are turned loose into a gymnasium, they will probably do themselves more harm than good ; the exercises should be designed for the require- ments of each, and should b(i steadily increased. They may be carried on more approjji-iately in winter than in summer, as the severity of our climate and the amount of snow on the ground occasionally pre- vent boys from engaging in the g;r,ies to wliich we have already alluded. Certain kinds of gymnastic exercLses are calculated to do harm to growing lads, more particularly exercises which cause them to hang head downwards for a long time. In using the climbing rope or pole, boys should not oo allowed to support the weight of the body with the legs. Skating is a favorite winter amusement in Canada, and if not indulged in so ' t to cause overheating, is one of the finest athletic exercises. Coasting and tobogganing are indulged in by Canadian boys during the col;! weather with great zest. If the use ,* aatclies appear other athletic stants sustain- ! subject from )nd of regular English public hat " quite as 3 from all the LOther English le, says : " The really trifling. L weeks, giving broken coUar- n. A broken ten years, i.e., J troublesome. TOulcJ consider was neglected, more than a rtant sources, ken systemati- eye. If boys do themselves or the require- may be carried the severity of casionally pre- have already Iculated to do :h cause them climbing rope lit of the body n Canada, and I of the finest idulged in by t. If the use Fig. 81. External Muscleg, The Copp Clark Co [.int'tfd.tbronto m n c< MANUAL OF HYGIENE, 245 of snow-shoes were more general, brisk walking exercise could be indulged in, even when the snow lies deep upon the ground. 681. Calisthenic exercises and work with the light Indian clubs and dumb-bells appear to be particularly suitable to girls during the winter season. Walking should never be neglected, and whenever the season will permit, romping games, such as "I spy," etc, will be useful ; also skipping ropes and dancing for younger girls. For older girls, lawn tennis and similar games in summer, with plenty of brisk walking and climbing, 682. Rooms used for gymnastic and calisthenic exercises should be provided with a very large supply of fresh air : and, if it is possible, these exercises should be carried on in the open air. In fine weather there will be no difficulty in doing t^is, and in wet or cold weather they can be carried on with great satisfaction under a long shed, boarded up on all sides, and properly heated and ventilated. These sheds should not have boarded floors, but a ground of loose sand or sawdust, which can be raked up from time to time to render it soft. This plan is followed in erecting covered gymnasiums in Switzerland, where considerable attention has been pa, i to the subject. 683. Alternation of physical with mental exercise is necessary to the well-being of the system, and enables it to undertake mental labor with greater satisfaction and better results. A change from one to tho Other is desirable for the folloAving reasons :— (1) Continued appli- cation to study is injurious to the eyes, and soon causes short-sighted- ness, even in the young. Physical exercise proves of service here by interrupting the application of the eyes to near objects, and exercising- them in calculating distances for jumping, vaulting, and particularly in sword exercises, where the eye observes not only the movements of the foil or single-stick, but reads in the eyes of the opponent his intended thrusts or cuts. (2) Physical exercise banishes inattention, which is a clog to all moral and intellectual improvement. Menier says, "that the gymnast shows his perfection when he can with the greatest coolness use every power of the body iot some definitely given object, and in making use of every advantage, execute apparent impossibilities through gradually won dexterity. As long as he does not give attention to what he is doing he is in danger." (3) It also conduces to activity and the acquisition of purpose and object in '■lii^i 246 MANUAL OF HYGIENE. study, which, in conjunction with attention and a cultivated memory, produce surprising results. (4) It preserves the strength of the body, which is necessary for the proper acquisition and retention of know- ledge ; for, as Hippocrates says, " the strength of the mind increases with that of tlie body. When the body is diseased the thoughts are distracted." (.'5) Alternation is beneficial, because it rests the brain. Close and long-continued thinking produces in many a feelin• of MANUAL OP HYGIENE. 249 groups and associations of groups that can be made out of 1,200,000,000 ccLa, no mathematician could calculate, and no one can imagine," 690. Over-pressure in study produces an irritated condition of the brain and its membranes which occasionally runs into tubercular meningitis; nervous twitchings and choreic movements of one kind or another are also occasional consequences to children from over- work at school, and long lessons to be mastered at home. Unnatural foix-ing before the brain structure is developed is an objectionable and unsafe proceeding, and may entirely defeat the objects of educa- tion. Bad constitutions, with the seeds of disease in them, unfit to stand the strain of life, are often the result of improper or imperfect growth and development. 691. The present system of rank and reward, based on success in reaching a certain standard, or in out-stripping others, is a great temptation to over-pressure, and should, therefore, be guarded against, especially in the cases of scrofulous or nervous children. Every men- tal effort is attended by brain wear ; the greater and more prolonged the effort the greater the wear ; unless sufficient time is allowed for repair, exhaustion ensues, and the brain is rendered less capable of renewed effort. 692. The habit of attention, is weakened by over-taxing the mind • and without a proper alternation of rest and work, instead of success in expanding, disciplining and improving the intellect, there will result only intellectual weakness, without the power of concentrated thought. 693. In this age of increasing nervousness or susceptibility to im- pressions, the effects of overtension or overstrain of the nervous sys- tem are particularly to be dreaded. They are insidious, often dis- guised for a time, attributed to other than the real causes, and fre- quently lead to a complete breakdown in the student's career, or to a necessity for a long period of repose to refit him for further work. Professor Humphrey, at the Glasgow Congress of Sanitarians held last year, remarked : " Many who have succeeded in reaching the examination goal had better never have sought it, never regaininf^ the mental elasticity which heavy pressure nas weakened and dis- appointing the hopes which early distuiction had raised." After referring to dangers to be avoided in the educatica of women he 250 MANUAL OF HYGIENE. II!' adds, "it is satisfactory to mark that the movement has been at- tended by a corresponding enlargement of the range and amount of bodily exercise. The gymnasium and lawn-tennis ground are the antidotes, and, therefore, the correlatives, to the study, and we may have good hope that increased and well-balanced exercise of body and mind will lead to a better development and greater strength of both." 694. "Give our girls fair opportunities for pliysical development at school," says a French author, " and they will be able in after life, with reasonable care, to answer the demands made upon them. Impair their muscular vigor by confining their growing frames in the fatal chains of fashion, and you increase debility, and even de- formity in the race to come. If we want our girls to be made straight, let them be made strong." 695. One of the principal effects of continued tension of the brain is to weaken all the organs more or less dependent on it, by depriving them of a part of the nervous influence necessary to their action. The organ most influenced by this privation is the stomach, and, as a rule, men who think most digest the worst. The sedentary life of profound thinkers has, however, a good deal to do with the delicacy of this organ. 696. "Success in the world depends on energy rather than on in- formation," says Herbert Spenser, in his work on Education, "and a policy which, in cramming with information, undermines energy, is self-defeating." Mr. Pridgen Teale, in a recent presidential address at Huddersfield on this bane of modern education, wound up with the following remarks : " Yet let it not be supposed that I am depre- ciating true education, or advocating idleness, or undervaluing hard work. Industry and hard work I value and sympathize with, both in educational and active life. Nay, more, it is my belief that hard work and long hours of work do not of themselves constitute over- pressure in education or overwork in life." 697. "It is the woric which is done under perpetual worry and anxiety, and under compulsion of want of time, that tries the health of young and old. It is because we are importing into our modern education hurry, worry and anxiety, selfishness, competitionj and feverish desire for success, prize-winning, place-winning and mark- MANUAL OF HYGIENE. 251 winning, all tending year by year to grow in intensity and become more powerful agents, that we have reason to fear it will result in injury to health, degradation of intellect, and to the departure from a true ideal of education." 698. By the hurry and rapidity, and number of subjects required to be learned in this railroad era, great injury is undoubtedly done to the mind. In the case of children approaching the age of puberty, there is special occasion for relaxation, particularly in the case of girls. Dr. Lincoln, writing on this subject, remarks : " The growth of girls for two or three years from the ages of eleven or twelve onward is very rapid, in fact, they then surpass boys of their own age, both in height and weight This rapid growth, and .... the moral development which should go with it, form, during those years, the most important functions of their existence." At this period children should be carefully watched, and their work diminished. 699. The age at which a child should go to school depends much upon the physical strength and temperament. For the kindergarten, from five to six years of age, and for the commencement of a systematic course of education, probably from seven to eight years of age, may be taken as an approximate standard. 700. At fifteen a new epoch commences. The passions are awak- ened, and the care of parents and teachers should now redouble. The former should exercise oversight of the character of the books read at home, prohibiting a great deal of the sensational literature of the day. The same remark applies to some quasi-scientific works on certain physiological subjects, the perusal of which is apt to do harm by engendering prurient ideas. 701. To keep children for two or three hours at a time in the often ill-ventilated school-room is open to grave objection. In England, most beneficial effects have resulted from what is termed the " half- time system," viz., three hours daily at school, and out-door employ- ment on farms or in workshops for the rest of the working hours; and it has generally been found that children thus employed make as good progress in study as tliose who attend school for six hours a day. 702. The amount of WOrK involved in home lessons should be carefully considered by the teacher, even though at first it may give 252 MANUAL oyaiKNE. I: It i h i i: il him some trouble, and requir ; some ^jnictical testing, to arrive at a just estimate of the time which tbey will occupy. The health of children may be injured by application unduly protracted in the evenijig, when mind and body arc weary and should be resting. On tlu- studious child injury is inflicted, though chec^' ":. ., , in those who are not so quick, besides the injury done to their health, a dislike to study is engendered. 703. Mental rest may be obtained by changes of occupation. Change from one „■ bject to another relieves the mental tension that would be experier-jcd by long and uninterrupted application to one subject. A brief intermission may be given at the end of each hcur, during which j^rymnascics and other suitable exercises may be practised by the scholarr3 mder the superintendence of the teachers. The physical exercises tend to promote the health of the pupils, and also greatly conduce to their comfort. Singing by the nupils in concert is an exhilarating and profitable exercise durin;- school hours. 704. Sleep in abundance is most necessary during the process of development. Up to four years of age the minimum auiount of sleep should be twelve hours a day, eleven hours from that to seven years, ten and a half hours from seven to ten, ten hours from that age to fifteen, and nine hours up to twenty years of age. 705. We are told by persons in authority, Ihat the death-rate of children is diminishing. In evidence of this, 8ir Ivon Pla^ fair, in a speech delivered in the House of Comniors in Ju' ] 1883, quotes the tables published by the Statisti ,il Soc.uty. Twu periods ,ue com- pared together, 1838 to 1854 and 1876 to 1880. In the latter period, among children from five to +ep years of age, there had T)een a diminution oi mortality of nearly thirty-five per c.uit., of whicii but six per cent, could be accounted for as the effect of improvement in sanitary surroundings. 706. But In diseases of the brain the pp""' ntage has not been reduced. Some interesting facts in this con ■ .o^ i ay be gleaned from the last Report ( 1 885) of the Registrar er.- r England, and the observations of Dr. Crichton Brown, the -juperintendent of the Edinburgh Asylum for the Insane. The increase of deaths from hydrocephalus, or water o:i the brain (which has taken place of late years), has not been among infants, but amongst persons over five MANUAL OF HYGIENE. 253 rrive at a just th of children the evening, ing. On the .in those ilth, a dislike t occupation. tension tliat cation to one j£ each hcur, 1^ be practised ichers. The )ils, and also in concert is rs. le process of ount of sleep seven years, that age to year of age. In deaths from consumption and other wasting di.s- eases, overwork has also been a leading feature in the failure of health. In Germany, Dr. Freichler has called the attention of physi- cians to the great increase, among boys and girls, of habitual head- aches, which he attributes to the exhaustive effort of excessive and ill-directed brain work in schools. Professor Huxley, in his essay on Technical Education, says: "The educational abomination of desolation of the present day is the stimulation of young j.eople to work at high pressure by incessant competitive examinations." 707. There is a U rge increase in the nuh..;er of suicides in the general community, and there is good reason for att.il.utin<' this in great part to ^.he fact that the struggle for life and the keenness of competition are too severe, and that there has been undue pressure and strain on the brain and nervous system in the fast age in which we live. 111 .1 '4 Jeath-rate of 'la) tair, in a 3, quotes the )ds ,ue com- a the latter re had T)een )f whicii but rovement in IS not been be gleaned Ingland, and dent of the leaths from lace of late IS over five if Nil CHAPTEK XXII. FIRST TIJKATMENT OF ACCIDENTS AND KME1UIENCIE3 : FAINTINO-SUF- FOCATK.X-DHOWNINr.-nANGINr.-ClIOKIXO-INJUBIOUS GAMEsl SUNSTROKE— TEMPOKARY SPLINTS — ARREST OF BLEEDING- BURNS AND SCALDS— FROSTBITE— niTES OF ANIMALS- CINDERS, ETC., IN THE EYE— FALLS AND BLOWS- SHOCK — FIRE-ESCAPES— FIRE-DRILL. 708. Accidents of a more or less serious nattue are of frequent occurrence, and in the absence of a medical practitioner, non-profes- sional persons may be called upon to furnish relief. A consideration of the most common accidents, and a few plain rules which may enable one to act in cases of sudden illness or injury until a physician arrives, will, therefore, be opportune in a work on Hygiene. 709. Fainting, or syncope, is due to a temporary diminution or sus- pension of the action of the heart, and is accompanied by interruption of the l>reathing and temporary insensibility. Fainting may occur suddenly; usually, however, the patient has some premonition, such as a feeling of sickness or uneasiness in the stomach, or swimming in the head, or mental confusion, while the bystanders observe its^ap- proach in the remarkable change of color in the countenance, which becomes ghastly pale. When the patient has passed into a complete state of swoon, the surface of the body is cool and clammy ; the pulse at first, very feeble, or entirely gone; the heart's sounds hardly recognisable when the ear is placed on the chest; he lies insensible to all about him. This condition continues for a longer or shorter time usually not more than a few seconds or minutes, and then the anxiety of the onlookers is relieved by the patient drawing a breath Con- sciousness speedily returns, and with it color to the blanched lips and face, and the power of muscular movement. 710. The causes of attacks of fainting are numerous and various . some of them operate on the heart itself, and others th,nu..h the medium of the nervous system. Among the most commo- in their MANUAL OF HYGIENE. 2-..-) oceui Tonce aro diseases or njiines (iuising yreiit luiiii : a Mow on tJ lie stc.nad. will also produce tainting. A-uin, everyone is familiar with the fact that faiutinK is caused by vioI..nt shocks, such as are pro- duced by intelligence of a joyful or mournful nature being .suddenly communi,.,.,ted, or from witnessing sights of a distre.ssing or revoltin".' character. Other intluenoes Imv.- a similar effect; for example a heated atmosphere or a crowded apartment, and certain overpowering od<,rs, more especially those which produce a feeling (.f nausea or sick- ness. A draught of cold water taken when the body is lu.t often exerts a most depressing inf!u<>nce, and may produc^e syncope;. Lo.s.s of blood IS a frequent cause of fainting, sometimes to a fatal degree When fainting occurs in connection with certain disea.ses as|' for example, disease of the heart-it is to be regarded as of a 'very dangerous nature, and not unf.-equently, under such circumstances death ensues. When. ,m the otJier hand, the attack of faintin.^ occurs in persons who are f.ee from any organic disease, and as the result of the operation of one or other of the causes of .syncope already mentioned, recovery speedily takes place. There are certain persons, chiefly females, wlio are peculiarly liable to faint. 711. The treatment consists in placing the patient in the liorizontal posture, the head l)eing on the same level as the body and exti-emities ; the access of fresh and cool aii- should be secured, and all tight articles' of dress removed. The ordinary smelling salts, or strong vinegar, sliould be held near the nose, and a little cold water dashed over the face : these means seem to arouse the nervous system and renew the .supply of blood to the brain. When the patient is able to swallow some warm brandy and water should be administered, - ..^f :\r„r:7o rrr::;t ..^^ - - - - hot wate, hot hHok/or ..Hhinlr,:':*!!™" ^'^ ^""'^ "' hands, and .Cir^g^^^Z^^^' """" ™™' *«'^' » -* *• and breathins. "^ "'"" "> "•"''o™ """«. "If the patient can swallow with snfoi,, m„„ i • i . place, ready for inmiediate use. '""^' convenient " To persons who cannot sioim.~Ii vou o-Pt i,.f . ,l , -epth. do not plunge, struggle, „or tLC ,t tnCd T""' Tl the water. ■ Tread water ■ in the erect nositL , "" ""'''' np and down, at the sa.e tin.e ^oZp^nZ'Z TT' ,'"', '''' .ng the,n under water. I, an, peL'n a;;;: t t^ "7" preserve your presence of mind and do nJ , • ^""' ten. .ou. „ an, .„a„ o,iect o^pptt ZIZ ^on" l!:' '!: under your chest or arm-pits and cU n^t * "to you, place it of the water; your head l^ n u. le 7ttf^ ^''^^^^ tions; and you may keep your mouth and ''''' ^^^^'^- enoughforassistanc'toalive By Iwl ^^^7 ^^^ W fully no^., you will be less apt to lose yo^ "it? t" -^T ^"'^ occasion arise for acting on them. ^ ' ""^ "'""^ ^'^""^^ " Parents should have their children taught to swim M , , might be thereby averted. ^''"^ ''«^*''« N.B.— In suffocation by smoke or ami ixnsonn,,^ «^o i • of /.,»..■„, or o;,„Hn,. p™„eed in the iiZ^^L ^2! L" "" °°^ f nott« to e.vpt,-i water, etc., irom the lunos " ° ft * MANUAL OF HYGIENE. 259 yment of the salts, or tickle kly, and dash at any time breathing is )ly bottles of convulsions I or with the iore warmth t coffee, tea, fresh air. W near the couvenieut eyond your Eii'nis out of \g the feet ands, keep- escue you, 'o what he u, place it ourself out liese direc- v^ater loner tions care- nd should tny deatlis 'o in cases ng, seeing itting t]i(> 715. When a person is found hanging by the neck, the first thing to be done is to remove all constrictions from the neck. The finger should then be pushed to the back of the tongue, and any mucus which may be found there removed from the mouth. Cold water should be dashed on the head and neck. If these means prove un- successful, artificial respiration should be tried. 716. Choking occasionally endangers life, owing to the presence of foreign bodies in the gullet, causing pressure on the windpipe. In such circumstances, the efforts of the sufferer to swallow may cause the passage of the obstructing substance downwards into the stomach. If this should not occur, assistance is required. The treatment con- sists in holding the head low and slapping the back. One or two fino'ers should then be put into the throat and efforts made to dislodge the substance ; or one hand should be placed on each side of the chest, suddenly compressing it, and thus producing a blowing out of the air. This latter expedient is more particularly useful in cases in which the offending substiiuce has been drawn into the orifice of the windpipe, which Ues just behind the root of the tongue, and in front of the gullet. V/lien the patient is choked by a piece of food, and we are sure, upon examination, tJiat it has passed below the opening into tlie windpipe, it may be disposed of, if suffocation still contiimes, by rapidly introducing into the gullet a long piece of whalebone, or other smooth, flexible substance, the end of which is protected by a piece of sponge or cotton batting, and pushing the morsel down towards tlu^ stomach. When the impacted body is of an unyielding nature, as, for instance, a piece of money, harm may be done by unskilled manipulation. 717. Infants and aged and intoxicated persons are sometimes acci- dentally suffocated by falling, so that the mouth and nose are buried in nmd, water, dust or other substances ; under such circumstances death may speedily take place. Persons are fi-ecjuently suffocated in lar<'e masses of grain. Accidental suffocation is not uncommon among infants when they sleep with adult persons. Even the close wrapping up of a child's head in a shawl to protect it from cold uuiy cause its death, without any struggles to indicate the danger to wliich it is exposed. Tiie treatment iu such cases is thu t>;Viue as that described in Sees, 713-716. 260 MANUAL OF HYGIENE. 719. Precautions must be iakpn i,of . . gas exists, „„„ particulari, ifX t " T? " "'■"" *''-« *- -1 ,, vat, etc. Li^e tl.rown into Ih 7 "^'- "^ " " "">" - or .t „ay, i„ certain cases, be got rid rf\v tf "°" '*'°*^ ""^ 8^' em-rents of air, caused by corniest ™ „ ^ u "'^'"'"^ °' '«'«»»sional Me, a jet of steam. Livl a,' !? ' "" " '"'""■ "'^ ''™"- sions i„ consequence of pdrde -e T""""""^ '«' °" «'~ oeea- vain expectation of at W:* J"^ °™ *' -".er, in the of the .nsensiblo person. T,,c „,„1° !k . u " '"P" *» "«> '""'y the level of the invisible str. umTf "", ""■"* """"^ «'«" the per.,„n connnonly sinks wClL"' «" """"="'■"■ ?"- i» lost, and s.fet,";,^-L^twl!tsV,rL"'drr'r'?° be a criterion of matures where a candle is e,xti„„u,',l ■!' ! "" ''"" '" «<^''' ture, but the converse of th s p „' 1". "f ™' ■* »* to ven- nnxture in which a candle tauin ! "e j' " ™''' "™<"y-'hat a It has been observed on sever, o "^^ "*»'"' '"* safety, ohareoa, has been .aintainrri r'Slhit ""' "°"'^"""°" »' found in a state of insensibihtv f . "'^ P^^'^^s have been 721. Carbon monox de t b '"" r'*^'"»" *^'« ^^P^^- of coal, .ood, o^^Zr fal a '^^^^^^^ ^''^"^ ^^« ^-^^-c, oo.b„.,on b-thing it in a concent .:ted W b^" ""'•*" ^"•^«"- P— action of this vapor is vevy Ins^u T'^^ ^■"^'^^^^^^^ ^^e "tter prostration of strength ZtlZ "' ''' '"* ^^-*« - the active, the gas may speedily produ a "?" T '. ^^^'^^ ^'^'^^^ --' call for assistance. ^ "^ P'^'^'^^* "^ability to move or to o"ait,t.t:::!:Xhif ti^r '"- ''^»«""* "-«"«' - 'iel* and cement worL, h, ve 1 XT "'"'"^ '■""^ ''■"-«''., brict: 723. Sunstroke, or heatjro t ,i^ i" T"''""''''- (S^-H-J?.) a Leated atmosphere, either wS o-t [*"""" "°° "■"*"«'" -».vs. Most ces are preceded bv he „h . °''""""' ^ "■" «""'■' P.t of U. .,«„„a..h, weatne. o/ttt^' ::»■■" 7"- at the " ees, and sometimes vo„,iti„g MANUAL OF HYGIENE. 261 iry, according intrated state the person is ce where this 3 in a we]] or 3rbs tJie gas ; f ascensiona] when avai]- 1 tliese occa- Jther, in the to tlie body mies within is lost, and criterion of '' in gaseous iafe to ven- ily— that a 'ith safety, bustion of have been 5m bustion Persons We. The icts is tlie *'ake and 3ve or to ned air, IS, briclf- 61-57.) rlfing in le sun's s at tjjg smiting and distorted vision. Insensibility follows these symptoms or -may occur suddenly The head is hot, and the face is red -r even purple. The breathing is slow and labored ; the pulse full, ouu weak. The treatment consists in placing the patient in a cool place and applying cold water, or pounded ice in cloths, to the head, back of the neck and spine. In a certain number of instances the symptoms are more those of exhaustion. The face is not as much flushed, and may even be pale. The pulse is frequent and feeble, and there is no difficulty in 1 wreathing. In these cases stimulants should be given gradually and the cold applications should be used sparingly. 724. Poisons are substances which, when taken into the blood, are capable of destroying life. They are divided into classes, according to their action on the body. (1), Irritants destroy the tissues and pro- duce nervous shock ; (2), narcotics produce insensibility by their action on the brain ; (3), narcotico-irritants combine the action of narcotics and irritants. 725. The general treatment in poisoning consists (1), in removing the poison from the stomach ; (2), in counteracting its effects by anti- dotes, which wUl mechanically or chemically render i+ harmless ; (3), in remedying the effects produced, and obviating the tendency to death : stimulants, artificial respiration and exciting the excretory organs are some of the means used for these purposes. 726. Emetics are used for the purpose of causing vomitinc- The safest "and readiest are irritating the back of the throat with the finger or a feather, large draughts of tepid water, combined with a tablespoonful of salt or mustard, or one or two tablespoonfuls of wine of ipecacuanha in water. 727. Acids and alkalies form antidotes to each other. The acids suitable for the purpose are vinegar, and the juice of the lemon or the orange, mixed with water. The alkalies are soda, potash, lime and magnesia, diluted with water. 728. Albumen and qU will T.rot< -f, the gullet and walls of the stomaih in poisoning by irrit -nts. White of egg, milk, flour and water, and .;astor oil u\ay be uhc h. 729. The tollowing are the mere common poisons and antidotes ; , ,xM,.<^., ..^hioV. ..Hnpnt. u-ith safety be emuloyed except by medi- I 262 MANUAL OF HYGIENE. 7n<^r.in(ly cial re- lia. fi'usion ; to the mful of Iff by MANUAL OF HYGIENE. 263 t hydrogen sulphide, the alkalies, the alkaline sulphides, and especially the alkaloids, with which iodine forms an insoluble compound. 731. Another ''multiple antidote" is given, as follows :— Saturated solution of sulphate of iron, 100 parts; water, 800 parts; calcined magnesia, 88 parts ; purified animal charcoal, 40 parts. The iron solution should be kept separately, and the magnesia and charcoal mixed in a bottle, and the whole well shaken together. It may be administered ad libitum, a wineglassful oi- more at a time. It is said to render preparations of zinc, arsenic and digitalis absolutely inert, and to partly neutralize the action of mercury, nioi-phia and strych- nine. It has, however, no action on the alkaloids, pho.spliorus or prussic acid. 732. Dislocations consist in the removal of bones from their natural position in the joints. The joints most s>.l)ject to 'dislocation are those of the extremities. 733. Fracture consists in the breaking of a bone. It may be simple, in which case the bone only is divided : or compound, when the tissues or integuments covei-ing the fractui-ed bone are also lacer- ated, making a communication between tlie bone and the extei-nal air. in dislocation, the restoration of the bone to its proper position is sometimes a matter of ease, but in other instances it is attended with no small difficulty. The sooner attempts at reduction are made after the accident which has caused tlu> dislocation, the better, they are then more certain to be followed by success, The same observa- tion applies to the case of fractures ; the setting of these is best effected as soon as possil)le after the reception of the injury. 734. For the treatment of both injuries experience and skill are required. It is of great importance, till suitable assistance can \^^^ obtained, that the injured parts be placed in a position at once the most comfortable to the sufferer, and in which a further injui-y is least apt to occur. The recumbent postui-e should, as a general i-ule, be maintained ; and in fractures all motion of the I)roken bone should be prevented by the application of splints, retained by a firm bandage. If the fmcture is a compound one, and bleeding to any extent Inns occurred, a handkerchief should be tied very tightly around the limb above the seat ot fracture, and a pledget oi lint or of cotton clotl^ wrung Qut of cold water applied over it, 264 MANUAL OP HYGIENE. materials dnefly used for ,.J , '"^ ^"'^ '" ^^^''^^^^d. The leather, ..tta-pLi' f t'Tintdt 1 T' ''^"' P-^^'^-"^' '-ay be fonned with uuL2^Z:^^:^,,fT^^f^^' ''''''' newspapers, policen.eu's trunch ons ad" ' ^ ^"' ^"^''' ^^'^^^^ '■ifles, swords or bayonets hJZT\ ,, . "'' ^"^P""^' «"«h as cotton wool, tow, flan "ior Ih t . '" "^" ^'''''^ ^^*'' -o^- "^ohed ealie; Hanne;;.^: . J!:;; J^ ^ ^^'^ ™^^« ^- ce.'!^ c!:!iiie:;t!:':::::;;;;i t r "^^ -- -^^ ^« -'« ^^^ ti-y are required, as follows :!' ^"" '^^ *^^^ ^"^'^ f--" -^ich ^"*'''"«^'-^ ? i-h wide, 1 yard long. ,„ " -^ '^'^-^^:^^:^:;::^-^- "P^^ '(??£?er SL::^^ ^!:-^" -"• -- and wor. (3) avoid wrinkles; (4) bancW fro Ti^ "^ l"' '""^^ '-^PP^^' ' the limb is of uniform thickn: s uT T " 7 ™'^ ' ^'^ "^'^"^ limb thickens reverse the snir. , ! '""P^" 'P^'"'"^'' ^^^ere the (6) reverse the ^^^:^^ Z:l:lr'; 7 f^« «^-e of oi.ht ; the sharp edges of the bone Th! • ^' '""'' "^^ "'^* --■ learned by prLtioal lessons ''"'"*"" °^ "^^"^^S- - ^-t 738. Haemorrhage, or bleeding, is the result of fi,. blood-vessel by a wound or otherwise Tt t ''P''""^ "* * HiBmorrhage it divided into (1 ) 2 ■ / T^ '''*''^"^' «'' "^t^'""*!. ingreatfo;e,andisoVrb:il\r:l^^^^^^^^^^ s ow,y-_wells out-and is of I dark p« ^ e^l r'' "w'^ '^ '^"^ there ,s a general oozing from the surface ' ^^ '"^''^^^"^' ''^''^ 739. The treatment in arterial haemorrhage consists in H ^ and examining the wound ; (2) washing if ^ \V ^^ «^Po«ing (3) elevating the bleedu^ ^plrUS "L J n " ""'' ^""''^ '' in a recumbent posture (iupo vh;. n ^ f """^'"'^ *" ''^'"ain over the mouths'of the l^^^n^^ ^V ''''''' ^"^^^^ .- ar.e^ o. the heart .de Wte ^^^ ^ wITT™ MANUAL OF HYGIENE. 265 for support- ected. The pasteboard, ized splints )xes, folded IS, such as with wool, made from e made in for which long. find work ' applied ; 5) where here the 5f eight ; not over ! is best ng of a utenial. ■ in jets, it flows ', where cposing watei' ; remain irectly to the d ancj . bandage (Fig. 86) — this bandage may be tightened by twisting it by means of a piece of wood inserted in it; (6) applying a pad and bandage over tlie wound as an additional safeguard. 740. Venous haemorrhage may occur with arterial or by itself, A superficial wound is more likely to divide veins than arteries. Dan- gerous venous bleeding often takes place when the patient has varicose veins and ulcers on the lower limbs. The direction of the flow of blood towards the heart, just the r%. IMAGE EVALUATION TEST TARGET (MT-S) 1.0 I.I 11.25 1^ 1^ Ki Ui US 2.5 2.2 I- ill 2-0 III 1.4 1.6 w Sciences Corporation 33 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 872-4503 |\ iV <> ^>:"^ ^'^^'. ^\ Wk\ u l/u k w i \ 268 Manual of HYotENfi. IM I irritation. In the severe or more complicated forms, the poisonous element is of a more active kind, and has been introduced from without, as by a distinct animal poison, such as the bite of an animal for example, or by tlie irritation of some foul substance on the instrument which caused the wound, or it may be generated in a foul wound. In the treatment of such cases, the wound or sore should be thoroughly cleansed. The atlected part should be raised higher than the rest of the body : if it be the foot, then it should be higher than the hip ; the hand or elbow, higher than the shoulder. The treat- ment should be entrusted to a surgeon, as soon as the servicers of one can be obtained. 749. Bites of rabid animals require imme- diate treatment. A ligature should, if pos- sible, be applied on the side nearest the heart (see Fig. 86) ; the wound should be sucked, and then bathed with warm water, so as to encourage bleeding. It should then be burned with hot iron, nitrate of silver, or strong carbolic acid. 750. Foreign bodies in the eye cause con- siderable annoyance, and may be removed in the following manner : if the foreign body is under the upper eyelid, seat the patient in a chair, and .standing behind, place a pen- cil or piece of stout wire on the central por- tion of the lid, lay hold of the eyelashes and erect the lid. Then having exposed the sub- stance, brush it off with the corner of a handkerchief. If it is under th'j lower eye- lid, simply depress this, and proceed a.- above with the handkerchief. 751. Concussion of the brain is caused by blows or falls upon the head. The characteristic symptoms are external bruises, etc., confu- sion of ideas, sickness and faiuling. The patient lies pale and shiver- Fig. 87. -Lymphatic vessels and glands of the lower extremity. MANUAL OF HYGIENE. 209 lie jjoisonous •duced from )f an animal of some fou] hich caused wl in a foul •h oases, the ily cleansed, higher than foot, then it tlie hand or The treat- surgeon, as ' obtained, [uire imme- uld, if pos- learest the should be inu water, hould then ' of silver, cause con- B removed reign body he patient lace a pen- Jntral por- lashes and id the sub- rner of a lower eye- iroceed a.'? upon the tc, confu- nd sliiver- ing ; he ,s m a state of stupor or partial insensibility. The treatment consists n< placing the patient on his bacl,, with the head slightly raised, in a dark, quiet room ; warmth should then be applied to the surface of the body and tlie extremities. Blows on the abdomen have already been spoken of a^ one cause of tainting. It may be well to observe that ruptures of the liver stomach, intestines, spleen and urinary bladder, occasionally resuU Ze" T ""7"''^ 'PP^"^^ '"^ '^' "^^""^'^- External marks or bruises on the ak.o.nen are not always present in these cases : in- s ances are on record where fatal result, have followed blows on the a^Klomen, and no marks whatever of violence were discoverable on the external surface. In treating cases in which such injuries are supposed to have occurred, it is v ell, until professional assistance can be obtained, to place the patient in the horizontal position, in a state of complete repose. Tiie circulation and respiration should be restored. All tightly fitting clothing should be removed from the neck warmth TLar'': v^ ''' ^f ^^^ '' ''' '"^'^ -' -^--^^-' ^^^^^ m smaJI quantities may be given. 752. Alarms of fire OCCurringin crowded buildings are often followed by distressing loss of life or severe bodily injury' People otherwise national and ...e I.odical in.their habits, become under the influence of panic a source of danger to their friei.ds and associates, and are of1.n quite unable to do themselves any real service. Great care and wa chf,,„ess are, therefore, necessary in the con.tr.,otion of public buildings, particularly sciiools, churches, theatres, etc., so that egress lum to the n,ain hall, and the outer doors, should be hinged so as to open outwards, and the passages leading to these doo:s sl.oulc be spacious. Staircases should be made as straight as it is possible t. have them, and their lower ends on the ground floor should always U maae to open opposite a door leading to the outer air 7o3 Permanent fire-escapes should also be provided by municipal by-law for all bui dings over two stories in height. The terrible acci- dents and loss of life by Are which frequently occur in cities and towns, prove that eflicient means of escape from a burning building are scarcely ever found when most M'.antod. ° 754. A cool, self-possessed deportment in the teacher, and the habit 270 MANUAL OP KYGIENE. of accustominf? the scliolars to firo-drill, will do much to rob a confla- gration of many of its terrors. Smoke may also be occasionally used during drill, so as to make the scene more reJistic. Obedience to the word of command should be prompt and unquestioning. 755. Children accustomed to fire-drill once a week are not likely in an emergency to give way to exhibitions of unbridled terror, but they will obey the commands of the teacher, and leave the room in an orderly fashion. Habits of this kind will be a valuable acquisition to the future men and women of the country, and may often be of service to +hem and their associates in after life. rob a confla- occasionally Obedience oniiig. not likely in ror, but they I room in an i acquisition often be of BPECIMENS OF SNELLEN'S TEST TYPES. With the distances at which thvij should he dialiiujuishahle. 100 Ft. 50 Ft. 40 Ft. B F L 20 Ft. E R P O A 10 Fe. V2BDFHKOSU LIST OP ILLUSTRATIONS IN THIS WORK. Fig. 1. Colored plate-Circulation of the blood '^*iP .1 2, Circulation of the blood in an intestinal villus 22 " ^- " " in the web of a frog's foot 22 II 4. Groups of air-cells „ . .1 5. Outline of the lungs, with the larynx, trachoa" an.V bronchial' tubes 24 II b. Section of the mucous lining of a bronchial tube, showing the cilia on the surface of the epithelial cells 24 .1 7-12. Diagrams of experiments with smoke, showing the circulation of heated air introduced into a room, the position of inlets and outlets being varied in each case 44_47 II 13-15. Various contrivances for window ventilation 48 II 16. Up-draught pipe II 17. Down-draught pipe ^, ,. 18. Revolving cowl, with down-draught or perflating action ......... 52 " ^^- , " " up-draught or aspirating action 52 II 20. Sheringham valve ,.„ I. 21. Watson's tube, with partition for inlet and outlet .....[... . ." * [ ] 55 II 22. Jacketted stove II 23. Modification of the Galton stove go I. 24. Smee's instrument for collecting moisture from the air for analysis 71 11 25. Sectional view of a Hull ash-closet 917 II 26. Pipe defective in contour j/w. .1 27, 28. Diagrams showing the relative depths of the same quantity of water in circular and ovate sewers respectively loi II 29. Improper laying of a box-sewer giving rise to deposit. ......... 101 11 30. Diagram showing how a box-drain (if used at all) should be laid to prevent deposit jq, II 31. Opening at the top of a joint from improper packing . . . . . . ' . . . 102 II 32. Improper junction ,„„ II 33 Proper junction ,.„ II 34. Palmer's trap, with the valve open 104 " ^^- 'I I' " closed iQ^ II 36. Various forms of traps .«- II 37. Street gully, with Guerin's trap in position !'.'.!.!.!! 105 274 Fig. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. r,o. .51. 52. 53. 54. 1 bi). 1 56. 1 57. M 58. »l 59. tt 60. tt 61. M 62. II 63. II 64. It 65. II 66. 67 68. LIST OF ILLUSTRATIONS. Enlarged view of the trap shown in Fig. 37 105 Section showing an efficient system of house drainage and drain ventilation 107 A bad form of closet in very common use, — the " pan-closet" .... 109 Form of closet recommended HO Mott's latrine HI Liverpool trough-closet H2 An intercepting sewer H'* Positions of viscera in the natural waist and in a waist deformed by tight-lacing 140 Distorted foot : dorsal surface 1*1 II II plantar surface 1*2 Natural shape of the foot 142 Properly made boot 142 Section of skin, highly magnified 145 Sectional view of the mouth and throat, showing the various parts concerned in masticatibn and swallowing 169 A lobule of the parotid gland highly magnifled 170 The teeth of a child between 5 and 7 years old, dissection showing temporary and permanent teeth 171 Diagram showing the times of eruption of the temporary and per- manent sets of teeth respectively 172 Section of a molar tooth ... 172 The alimentary canal below the oesophagus 174 The mucous membrane of the small intestine highly magnified ... 176 The iris and ciliary processes, as seen from behind 182 Diagram showing the pollution of water by sewage percolating through the soil 196 Domestic filter 206 Small tank-filter, upward filtration taking place when taps are opened "07 Filter with catch-pit and tank 207 , Hyatt filter, on the large scale, containing mechanism for cleans- ing its contents 209 Antero-posterior section of the eyeball 211 , The muscles of the right eye 214 , Diagram illustrating both the divergence and "practical parallel- ism " of rays of light 214 . Diagram showing how the rays from each point of an object are brought to a focus on the retina, a distinct image of the object being thus formed 215 Diagram showing that the same refractive power will not bring to a focus at the same point the rays from near and distant obiects 215 MM 105 ind drain 107 set" .... 109 110 Ill 112 114 deformed 140 141 142 142 142 145 ious parts 169 170 ti showing 171 f and per- 172 172 174 jnified ... 176 182 »ercolating 196 206 a taps are 207 207 for cleans- 209 211 214 il parallel- 214 object are ' the object 215 ot bring to nd distant 215 LIST OF ILLUSTRATIONS. £75 Fig. 69. Diagram, howing increase of refraction by increased thickness of""" .. 70. DiagramiIlustratingtheme;hanismof';a;;ommodat;ou'" "Is " 71. Diagram shown.g the respective contours of the '< far-sighted* " normal and "near-sighted "eye lar s.gi.tecl, .. 72. Action^of a concave lens on rays entering a nearsighted" or myopic .. 75. Skeleton view of spinal curvature f*** " ^P'°,^^„^;^;'™'*y - the living person acquired from faulty posi". " 78" S*"TVr"!.'" '^'^' *'°^y ^"^ '^^'"g P^''-«"n' '■"■'.'. 234 " II ^•^J"^^^^^, ^''hool-desk and seat, the former with sliding top 235 " 79. Muscular fibre, highly magnified ^ ^ f'^ .. 80. Cross section of the heart, showing its vai;es ■.■.■;;: ." o!'! " t' S^^^r Pl'^*«-E^ternal muscles of the body . . ^if '- »^- 1 he larynx, as seen from above " ''■ ^"*thrio"?h"'*;''T''^'= to;emovVwate;'and mucus from ''' the mouth and windpipe .. 84. Second position : for the purpose of ■d;awing'aiV into thelungs " " ' 2^ .. 80. Third posihon: for the purpose of expelling air from the lungs " ' ' 257 n 86. Arrest of circulation by twisted bandage . . . . ^ ' " fj " Z' p^^P^lf •= ^^««^'« ^"^ glands of the lower extremity .' .' .' .' 7 II 88. Page of test types. . ^ 2Vi INDEX. (Tike numerals refer to sections, not to pages.) A. B. C. process of precipiUtioii of sewiige, 280. Absorption of digestive products, 482. Aciirus, 448. Accidents, 708 T.'),'). "Accommodation" of the eye to near and distant ol)jects, 591 -59.S. Acids and alkalies as antidotes to each other, 727. mineral, antidotes for, 729. Acid, carbolic, antidotes for, 729. oxalic, antidotes for, 729. prussic „ „ 729. sulphurous, for disinfection, 330. Actinomycosis, 442 Adulterations of bread, 449. butter, 450. Cayenne pepper, 459. cheese, 451. cocoa, 454. coffee, 452. confectionery, 456. flour, 448. milk, 447. mustard, 460. pickles, 458. sugar, 455. tea, 453. vinegar, 457. Aeration of the blood, 36. Aeroscope, 155. Africa, West Coast of, 178. Age at which children should go to school, 699. of .puberty, 700. Air, action on the blood, 36 ammonia from organic matter in, 152. amount required for lights, 77. It II for ventilation, 72-77. II II for respiration, 72. II II in sickness, 75. Air, animal organic matters in, 51, l.'>2. ascensional currents, from soil ami drains in houses, 217, 220, 224. bad, effects of in the British army, 66. bad, effects of in civil life, 67, 68. carbon dioxidu in, 48. carbon monoxide in, 54. chemical examination of, 149-152. composition of, 45. constituents of, described, 44. cooling of, 81. examination by the senses, 148. impure, effects of, 65-68. impurities in, 49, 50. II from combustion, .'JS, 54. II from gases and vapors, 57. II from marshes, 64. II from metallic dust, 59. II from putrefactive pro- cesses, 55. II from sub-soil air, 63, 188. II from smoke, H2. li from upholstery, 60. 11 from wall papers, 60. -meters, 145 147. moisture in, 141. of churchyards and vaults, 64. of marshes, 64. oxygen of, 46. ozone in, 47, 200. pollen in, 61. pollution of, by refuse, 21 1, 212. putrefactive processes, deleterious ef- fects of, 55. rules for estimating the quantity re- quired, 70-72. sewage emanations in, 56, 211, 212 221-227. smoke in, 02. suspended metallic, mineral and veg- etable impurities in, 58-61. S78 INDEX. k Air, tenipeiature seating of pupils, 651. by impure waters, 564-567. by occupations of various kinds, 15 16, 58, 59, 67. ' by tight-lacing, 360. Disinfectants, list of, 330. Disinfection, ,330-341. Dislocations, 732. Disposal of refuse, dry systems, 230-241 pneumatic systems, 278. principles to be carried out in, 215. removal should be complete, 215. , " " without delay, 215, violation of principles, 216-229, water-carriage system, 242-284. Disposal of sewage, ultimate. 279-284 Distoma, 442. 282 INDEX. Dover, reduction of death-rate in, 13. Drainage, diminutionof sickuessby, 194 Drama (see also Sewers). bed of, 24tt. fall of, 249, 250. flushing of, 251. forces acting in, 224. joints of, 247. junctions of, 248. leaky, uneven, etc., 217. materials of, 244. of houses, plan of, 262. overhead ventilation of, 227, 228, 262. plans, preservation of, 263. shape of, 245. Dressmakers, average age at death, 14. Dnnkuig vessels for schools, 657. Drinks, iced, good and bad effects of 488. Drowned, treatment of, 714. Druggists and Chemists, average ace of, at death, 14. *" Dry-earth and dry-ash closets, 232-240 ashes for, 233-238. earth, kind of, for, 236. inoffensive if properly treated, 236. should be automatic for children, 237 Dublin institutions, statistics of, 68 Duodenum, 478. Ear, auditory nerve, 636. auditory canal, 632. blows, injurious effects of, 645. catarrh, chronic effects of, 640-642. catarrh effects on the ear, 639-641. cultivation of the organ of hearing 637. drum of, 635. exposure of, to cold draughts, 638. foreign bodies in, 644. internal, 633. perforation of drum of, 639. striking injurious, 645. structure of, 631-636. teachers should r te defects in hear- ing, 646, 647. tympanum, 635. ^ wax, deafness from, 643. Education, what it comprises, 687. Effete material in the blood, 395. Egg, white of, composition of, 427. 1! yolk of, composition of, 427. Electricity in atmospheres, 190, Elements of food, 408-413. KUisou's bricks, 107. Ely, reduction of death rate in. 13. Emetics, 726. Emetic, tartar, antidotes for, 729. Emphysema produced by severe exer- cise, 678. E>idemics, 289. England, statistics of, 3, 4. Entozoa in food, 442. in water, 567. Epidemics, 289-291, ct. seq. advantage of use of trough form of latrine during, 273, 274. causes that have lessened, 291. death-rate from, declining, 347. modern hypothesis of nature ofj 292. opmions of ancient writers, 292. Pasteur's discoveries in, 292 records of, 290. Epidermis, structure of, 373 Epiglottis, 474. Etiolation, 170, 171. Examination of air, 148-158 food, 437-460. ventilation, 142-158. water, 540-563. Excreta, amounts of, 208. disposal of, (see Disposal of Refuse and Sewage.) Excretory organs, 380. Exercise, mental (687-707). (See Men- tal Exercise. ) Exercise, physical, 661-686. advantages of, for those who follow sedentary pursuits, 661. excessive, emphysema produced bv 678. •" heart disease produced by, 677 kindergarten, 686. long continued, cools the body 389 rooms used for, 682. Expiration, 37. Extraction, ventilation by, 116-123. Extremes of temperature endured, 388 Kye-ball, anatomy of, 582-588. Eyes (see also "Far-sight," "Near- sight," "Squinting"), accommodation of to near and distant objects, 591-593. care of in childhood, 609. II in infancy, 606-608. condition of, as influencing occuna- tion, 626. *^ foreign liodies in, 750. '"iTr^fiJ "^^^"^^^ ''^ ^^°^*^ application, J I I I ii F F F F Index. tein, 13. for, 729. severe exer- Kyes, injurious effects of delaying use of spectacles, 624 283 J- ugh form of 4. i, 291, »g, 347. fcure of, 292. rs, 292. 292. 3. I of Refuse (See Men- ivho follow )duced by, ,677. body, 389. 16-123. lured, 388. 58. " "Near- cd distant g occupa- tplication, M II improper direction of light, 612-615. II II reading by dim light, 625. " " undue exposure to light, 607-611. muscles of, 588, 594. quack applications to, 628. single vision of, 594. sore, 606, 609, 610. ti precautions against contagion from, 610. stereoscopic action of, 295. Fainting, 709-711. Farmers, average age of, atdeath, 14, 15. wives, „ „ „ 14 15 Far-sight, 597, 598. Fats, or hydro-carbons, 418. composition of, 427. Fatty matters in the blood, 22. Feet deformed by boots, 366, 367. Fencing, 672. Ferran, Dr., and cholera in Spain, 292 Fevers (see under Specific Names ; also, see Malaria). Fibrine as food, 410. Fibrine of the blood, 20. Filter, domestic, 572. Hyatt, 578. large, with mechanism for washing filtering agents, 578. small faucet, 574. small tank, 573. tank, large, 575. Filtering materials, 571. should be frequently changed, 577 Filters, benefit of, 576. on the large scale, 575. Filth (see Refuse and Sewage) total amount of in communities, 210. Filtration of water, 571-578. of sewage, 281. Fire, alarms of, 752. drill, 754, 755. escapes, 753. "Fire-king," 386. Fires, 135-137. Fish, poisonous, 444. white, composition of, 427. Fishermen in Ontario, averag6 age of. at death, 14, 15. ° fa » Fives, 673. Flour, wheaten, composition of, 427 blowers in school, 660. Focussing of rays of light, 590-593. tood, regularity in taking, 484. Ifoods, canned, 445. classification of, 415. force-producing, 414-419. heat-producing, 414^419/ inorganic forms, 420. tissue-forming, 413-419. ultimate uses of, 416. water in, 421. Foreign bodies in the ear, 643, 644. " " eye, 750. V . " , '' throat, 716. fracture of collar-bone, and extremities m playing football, 679. fractures, 733. treatment of, 734. Frankfort-on-the-Main, sewerage and typhoid fever, 12. Frankland, 208. Fraser river, 203. Frost-bite, 747. Furnace, portable,for disinfection .333 Furnaces, 129-134. ' Galton, Capt, on death-rate and sanita- tion of cities, 12, 13 Galton grate, 137. Garbage, improper disposal of, 216- '>20 Gardeners, average age of, at death! i-4| It). Gas aiding in ventilation, 91. disposal of impurities from, 91 Gases more common forms in sewers, _ ^fS. (Also see Sewer Gases). irritant, antidotes for, 729 Gastric juice, 478. General circulation of the blood 27 Georgian Bay health resorts, 203 " '^f, 212!"' °^ ^*''"" '''''■*^*'' *'="°" Germ theory, 292-295. Girls to be strong, 694. Glands, intestinal, 479. lacteal, 482. lingual, 464. lymphatic, 748. submaxillary, 464. Glucose, 456. Goitre in limestone districts, 18a, 664 Granitic rocks, 183. . "»". Grape sugar, 455. Gravelly soils, 184-187, i84 INDEX. M Ground-air, 61, 188, 18!), 213. polluted by sewage, 213. Ground-water, 193. Growth of brain, 689. ».?id nutrition, 379. Guerin's gully trap, 256. Gymnasium, 680-682, 693. Gymnastics and calisthenics, 680, L I. rooms for, 682. Hfematine, 19. Hajmorrhage, treatment of, 7.^-745. from the nose, causes of, 743. II treatment of 744, 745 internal, treatment of, 742. varieties of, 738. Hairs, cells of the epidermis, 377. Half-time system in schools, 701. Hamilton, statistics of, 12. crematory in, 12. Hand-ball, 673. . Hanging, what is to be done in cases of, 715. Hat-hooks, 650. Hay-fevar, 61. Headache in school children, 706. Head coverings, 363. effects of the sun on, 363. Health, influence of electricity on, 199 II II of ozone, 200. It II of winds, 197. II resorts in British Columbia, 204. II II of Canada, 203, 204. II If of Muskoka, 203. II II of the Rocky Mountains, 204. II 11 on the lakes of, 203. II II in the Lower Provinces, 203. Hearing, cultivation of, 637. causes of defects of, 638-645. defects should be noted by teachers, 646, 647. Heart-disease from physical exercise, 677. valves of, 677. Heat, degree of, endured, 386. disinfection by, 330. effects of, 165, 167. kinds of, 127. protection against, 352. Heating, 125-140. by hot-air furnace, 129. by steam, 138. Heating, by stoves, 128, 135, 136. by water, 1.39. position of dampers in stoves and furnaces, 132. precautions against over-heating by stoves or furnaces, 130, 131. proportion of inlets and outlets in a hot air furnace, 133, 134. Heat-stroke, 723. Helpless intoxication resulting in death, .391. Hemorrhage (see Hiemorrhage. ) Hirter, 124. Hitchcock, statisticsof alcohol, 515, 516. Horseback exercise, 674. Hot air, 129-134, 137. watei-, heating by, 139. House-drainage, plan of, 262. Hull ash-closet, 233. Humidity (see Moisture). Humors of the eye, 588. Humus, or vegetable mould, 192. bad feitc for dwellings or school- houses, 192. power of absorbing moisture, 192. Hunger, sensation of, 462. Hunters, average age of, at death, 14, 15. Hurry, injury to the mind from, 698. Hyatt's filter, 578. Hydrocarbons or fats, 418. Hydrocephalus, increase of, 706. Hydrogen for formation of tissue, 408. Hygiene, definition of, 1, importance of, 2, 3. objects of, 1, 2. Hygrometers, 157. Hygroscopic power of clothing, 350. power of soils, 191. Hypermetropia (see Far-sight). Ice, iirpure, effects of, .'iSO. Images, formation of, on the retina, 589, et seq. Incubation of infectious diseases. periods of, 320. ; . India, statistics of, 8. Indian meal, composition of, 427. Infection and contagion, 287-347. (See also Diphtheria, Scarlet Fever, etc ) defined, 287, 288. Infectious and contagious diseases. (See also under specific names, "Diph- theria," etc.) causes that have lessened, 291. classified, 288. lNr)EX. \5, 136. stoves and '-heating by , 131. 1 outlets in 134. Iting in age.) 101,515,510, 28- I, 192. or school- ure, 192. eath, 14, 15. Tom, 698. 706, tissue, 408. ing, 350. It). the retina, diseases. ,427. -347. (See Fever, etc. ) eases. (See Js, "Diph- 291. Infectious and contagious diseases, description of, 296-310. diminution of, 291. premonitory symjitoms of, 297. symptoms of, 296-310. theories regarding causation oi, 292. 293. Inlets for air, cleanliness of, 80. position of, 83-87. size of, 82. Inorganic ailments, 420, Insalivation, 464-5. Inspiration, 37. Intellect, degradation of, 697. Intercepting sewers, 277. tanks, 277. Intestines, 476. Intestinal glands, 479. villi, 482. Intoxication increases tendency to deatli from exposure, 391. Iris, 497, 498, 585. Iron pipes, quality of, 244. Irrigation with sewage, 282-284. Irritant gases, antidotes for, 729. Isolation in infectious diseases. 324-327, 3.32, 335, 338, 341-346. Itch, 308. Jacketted stove, 110, 136. Kaffirs and diseased meat, 4.38. Kindergarten exercises, 686. Kingston asylum, ventilation of, 1 22. II II filtration of water of, 578. Lacteal vessels and glands, 482. Lactometer, 447. Lactoscope, 447. Latitude, 159. Latrines, 269-275. Laudanum, antidotes for, 729. I^wn tennis, 693. Lead poisoning, 59, 536, 538, 565. salts of, antidotes for, 729. sugar of, „ „ 729. Leaping, 669. Leguminous foods, 429. Leicester, reduction of death-rate in, 13. Lens, concave, 598. convex, 598. crystalline j( the eye, 588, 591. Lenses for astigmatism, or confused sight, 602. Leptodera teres, 442. Lessons, amount of, 702. Lieruur system of sewerage, 278. Life shortened by intemperate habits. 515. saving of, 3, 7, 12, 13. Light focussing of rays, 590-593. colors which form, 629. injurious effect of glare of, (K)7, 611. proper direction of 612, 616, Lime, antidotes for, 729, Lingual glands, 464. Liver, 479, 481. of ox, composition of, 427. Liverpool trough-closet, 271. London, statistics of, 12. Louvres, 106. Lower Provinces, health resorts of , 203 Lungs, capillaries of the, 36. and skin, daily amount exhaled from, .181. exposure of blood to air in, 36. structure of, 33. Lymphatic vessels and glands, 748. Macclesfield, reduction of death-rato in, 13. "Made soil," 190, 220. Madison Square Theatre, ventilation of, 123. Malaria, 179. influence of altitude on, 181. .1 brushwood on, ISO. II cultivation, 180, 196. II fires, 180. II first turning up of soil. 180. II marshes, 180. II season, 180. II sheets of water, 180. II time of day, ISO. II trees, 180. II vegetation, 180, 196. II water, ISO. M winds, 180. laws governing, 180. Manchester ash-closet, 234. Manometer, 147. Maritime quarantine, 341. Mark-winning, 697. Matches, antidotes for poison of, 729. Mats and scrapers, 648. Maxillary glands, 464. McKinnell's tubes, 114, Meals, benefits of regularity of, 484. 286 11 lNt)EX. Measles, breeding places of the conta- gion, 311. contagion of, 315. M duration of, 321. description of, 297, 2J»S. duties of school authorities regard- ing, 346. * incubation, 320, Meat, 438-443. bad, 438-443. boiled, composition of, 427. diseases caused by, 438-443. examination of, 443. roast, composition of, 427. Memphis, 220, 252. Mental exercise, 687-707. alternated with physical, 703 elasticity lost, 693. faculties, their relation to physical and moral faculties, 688. overstrain, 688, 690. lest, 703. too long continued, 701. Mercury, antidotes for, 729. Merthyr, reduction of death rate in, 13. Microbes, micro-organisms, micro- zymes, 295. Microscopicexamination of air, 153-155 of Hour, 448. of meat, 443. of tea, 453. of water, 543. Mildew in flour, 448. Milk, adulterations of, 447. bad, effects of, 446. composition of, 427, 430. examination of, 447. new, composition of, 427. skim, composition of, 427. Mineral acids, antidotes for. 729. Miquel, 330 Moccasins, 368. Moisture in air, 79, 141, 157, 175, 176 m clothing, 350. in soils, 191-193. Moral faculties, 688. Morphine, antidotes for, 729. Mortality statistics (see Statistics), Mott's latrine, 270. Moule's dry-earth closet, 237. Munich, sewerage and typhoid fever in, Sluscles, 661-666. Muscles, involuntary, 664. voluntary, 662, 666. Muscular contraction, 663. fibre, 665. Mushrooms, composition of, 427. Muskoka, liealth re.snrts of, 203. , Mustard, adulterations of, 460 Mutton, fat, composition of, 427. lean, composition of, 427. Myopia (see "^fear-sight,") Narcotics, antidotes for, 729. Natural ventilation, 94, et sea, "Near-sight," 596. i increase of, in modern times, 617. remedy lor, 598. Neck-covering, 364. Nervousness, increase of, 693. Newport, reduction of death-rate in, 13. Nitrate of silver, antidotes for, 729. Nitrogen for formation of tissue, 408. North- West Expedition, food used in, 429. Nurses' duties in cases of infectious diseases, 3.34. Nutritive principles in food, 427-4.30. Nux vomica, antidotes for, 729. Oatmeal, composition of, 427. Occupations, relative healthfuhiess of, 14. Oidiurn lactis, 446. Oil of vitriol, antidotes for, 729. "Old-sight, "599. Ontario, health resorts of, 203. statistics of, 5, 7, 12, 14, 16, 67. Ophthalmia, purulent, 609, 610. 649. Opium, antidotes for, 729. ' chloral, and other narcotics, 5''3 524. I effects on circulation, 498. Optical defects, 595-604. Organic aliments, 409-411. ! Organisms in air, 212. Organs, excretory, mutually depend- ent, 380. ^ "out of order, "396. Out-door employments, statistics ol long duration of life in, 14, 15. Outfall of sewers, 219. Outlets for air, cleanliness of, 92. position of, 83-86, 90. size of. 82. Overhead ventilation of drains. 227 '^H 262. '.— <3. INDEX. I. if, 427. if, '203. , 460 tif, 427. 29. seq. 1 times, G17. 393. h-ratein, 13. I for, 729. iissue, 408. 3od used in, afectioiia 1, 427-4.30. 729. 127. hfuhiess of. 729. JOS. 16, 67. 610, 649. ;otics, 523, ly depend- iatistics oi 14, 15. f, 92. 13,227,228. Over-heating, 130, 131, 156. Over-pressure, 690. Over-work, influence on diseases of the brain and digestion, 69,5. Ox hver, composition of, 627. Oxygen for formation of tissue, 408 in tlie blood, 43. Oysters, composition of, 427 Ozone, 47, 200. ' influence of, 200. 287 Paint, antidotes for, 729. Palate, soft, 473. Pan-closet, 26-1. Pancreas, 479. nature and offices, 480. Parasites in food, 442. in water, 567. Paregoric, antidotes for, 729. Pans green, antidotes for, 729 Farkes, Dr., 8, 9. 208. Parotid gland, 464. Parsnips, composition of, 427. Pasteur's discoveries, 292. Peas, dry, composition ofj iJ7. Pepper, Cayenne, 459. Pepsin, 478. Peptic glands, 477. Peptones, 478. Perflation, 98, 105. Permanganate of potassium as a disin fectant, 330. for testing water, 558. Pettenkoff'er on water in soil, 193, 194 fnosphorus, antidotes for, 729. Physical development, 667-686, 694 faculties, 688. Pickles, 458. Pictures in school, 660. Pipes for water, 538. for drainage, 244. Place-winning, 697. Plague, 290. Playfair, Sir Lyon, 705. Pneumatic systems of sewerage, 278 Foisoning, emetics in, 726. general treatment of, 725. Poisonous material, absorption of, 748 roisons, antidotes for, 729-731. care in storing, 332. classification of, 724. rat, antidotes for, 729. Pollen in air, 01. Pollution of air, 211. Pollution of soil, 213. of water, 214, 229. Pork, fat, composition of, 427. lean, composition of, 427. Porter, composition of, 427. Potash, caustic, antidotes for, 729. Potassium for tissue-formation, 408 cyanide, antidotes for, 729. Potatoes, compooition of, 427, Potato flour in bread, 449. Pott's cornice, 112. Poudrette, 280. Poultry, composition of, 427. Precipitation of sewage, 280. Premonitory symptoms of ' infectious diseases, 297. Presbyopia, 599. Preservation of drainage plans, 263 Printers, average age of, f,t death 14, 15. Printing offices, vitiation of the air of, 15. remedy for, 91. Prize-winning, 697. Process of growtli and nutrition, 379 Professions, various, relations of, to sanitary science, 2 Propulsion, ventilation by, 122, 123 , Protein compounds, 417. I Prussian-blue, 453. Prussic acid, antidotes for, 729 Puberty, age of, 700. Pulman, sewerage of, 284. Pulmonary circulation, 28. " Punch-bowl " sites, 187. Pupil of the eye, 585. efiects of opium and alcohol on, 497 498. Purification of sewage, 280-284 of water, 568, et neq. Pyloric glands, 477. Quarantine, 341-343. Railroads and color-blindness, 630. and infectious diseases, 343. dry-earth system for, 343. '^*i^^ay employees, average age of, at Rain, action of, on atmosphere, 630. Kainfall and sewers, 243, Rain-water, 530. Rank and rew.wd, 691. Rat-poison, antidotes for, 729. Recesses, good effects of, 684-703. 288 INDEX. Reces8e8usefuHnpromotinghealth,684, Ked Elver Expedition, absence of li. quor, 502. Refuse (also see Disposal and Sewage) dry systems of removal, 231-240 of what composed, 206. pneumatic systems of removal, 278 principles in disposal of, 215. ultimate disposal of, 282-284. water-carriage system, 242-284 Registrar-General's Reports, Ontario. 5, 7, 12, 14, 16, 67. Respiration, 32. amount of air used in, 40. changes produced in the biood by, 42 diHusion of gases during, 41. mechanism of, 39. movements of, 37. Retina, 586, 589, et seq. inj^irious effect of glare of light on, Re-vaccination, 339. Rice, composition of, 427. Riding in a carriage, 675. Ringworm, 309. Rochdale pail-system, 238. Rotheln, 300. Rowing, 671. Rugby, reduction of death rate in, 13 Running, 670. Sailing, 675. Salisbury,reduction of death-rate in 13 Saliva, 464, 465. flow of, retarded by sipping at meals, 400. Salts in water, 562, 564. of lead, antidotes for, 729. of mercury, „ 729! Sandy soils, 183, 184. Sanitary cordons, 341-343. reforms, changes effected by, 4. baundere, Sedgwick on overhead venti- lation of sewers, 227. Saving of life effected.'s-?, 12, 13, 347. Scarlet fever, breeding places, of, in the body, 311. . . " cleanliness during epidemics, 340 contagion, sources of, 311, 313. modes of conveyance of 31i. " duraton of, 313. contagiousness, pci.'od of, 321. convalescence the worst time fori spreading, 322, Scarlet fever, deaths from, lessened of late years, 7, 347. description of, 299. disinfection, 329-337. duties of school authorities and others regarding, 327, 346. incubation period of, 320 isolation, 324-327, 332, 338, 341-346 laws regarding, 345. mild case as infectious as severe one, 323. notification of cases, 327. precautions to prevent, 323-346 premonitory symptoms, 297. Scheele's green, antidotes for, 729. bchonbein and ozone, 200. School-age, 699. -desks and seats, 651-653. -furniture, blackboards, 656. |> blinds and curtains, 655. II care of, 659. M clothes and hat-hooks,650 " desks, suitability of, 651. " dineases caused by impro- per 8eatingofpupil8,661. " drinking vessels, 657. ir flowers, pictures, etc. , 860. i> hat-hooks, 650. " position of pupil at his desk, 651. " pupils measured and seats assigned, 653. " seats and desks, adjust- able, 652. " thermometer, 658. 1' too long continuance in one position, 654. n wash-basins, 649. hchool-room should be cheerful. 660 bcnool-work, excessive, 702, Sclerotic coat of the eye, 683 Scrapers and mats for schools', 648 Seamstresses, average age of, at death. 14, iO. ' Seating pupils, rules to be observed in. Seats and desks, 650-653. adjustable, 652. Seats at school, 651, 653. Sebaceous glands, 375. Sensational literature, 700. Separate system, 252. Serum of the blood, 17. Servants have fewer death?, from c-on sumption than teachers, 16 INDEX. 289 , lessened of ies and others 0. 338, 341-346. 8 as severe 323-346. 297. for, 729. 656. tains, 655. b- hooka, 650. ity of, 651. d by impro- fpupil8,661. Is, 657. 2s, etc., 660. ipil at his d and seats 3. lis, adjust- 158. inuaDce in 654. 9. •ful, 660. 3. Is, 648. , at death, ^served in, from eon I. Sewage (also see Disposal, Drains, Kefuse, Sewers). disposal of, 205-286. It principles to be aimed at, 215. If ultimate, 279-284. I) violation of principles, 216- 229. filtration, 281. irrigation, 282-284. precipitation, 280. removal neglected, 216. ti incomplete, 217. " ir examples of, 217. II not effected till matter has decomposed, 218. II this often resulting from faulty drains and sewers, 217, 218. II to unsuitable place (impro- per outfall), 219. , " ^ II e.xamplesof,219. violation of principles in ventilation of drains and sewers, 221-227. Sewerage (see also Drains, Disposal of Refuse, Sewage, Sewers), statistics of reduction of death rate, 12. influenced by physical character of soil, 243. II water supply, 243. Sewer gases, 221-228. causes producing, 224. certain kinds of, often inodorous, 222. deaths from, 223. escape into houses, 226. " I' examples of, 226. in the street, 225, 227. negative evidence not to be relied on, 222. overhead disposal of, 227, 228, 262. polluting drinking water, 229. the most common forms of, 223. Sewers (also see Disposal, Drains, Sew- age, Sewerage), absence of proper ventilation of, 221. bed of, 246. fall, and experiments regarding, 250. forces acting in, 224. intercepting, 277. junctions of, 248. pneumatic system, 278. separate system, 252. ahape of, 245. water-carriage system, 242-284. I Sewer-traps (see Traps, 253-562). Shell-fish, 441. Sheriugham valve, 108. Shoes, 367, 368. Shone system of howerage, 278. Sight (.see Eye, "Far-sight," "Near- sight," Vision). contused, 600, (iOl. I! remedy for, 6l)2. weak, 604. Silver, nitrate of, antidotes for, 729. Singing, 685. Sites for schools and dwellings, 18 Skin (also see Bath), 372-388. ability of, to resist changes of tem- perature, 385-388. II II lessoned by debilitat- ing causes, 390. action of very cold water on, 398. active exercise raises temperature of, 401. bathing increases activity of func- tions of, 397. cooling of, after long-continued phy- sical exercise, 389. degree of cold endured, 387. exhalation, amount of, 381. extremes of temperature endured bv. 385-388, ' general principles regarding action of sudden changes of temperature on, .393. heat-regulator of the body, 383. high degree of heat that can be endured through action of, 386. medicines thrown out by, 382. not an independent tissue, 378. obstruction should be prevented, 394. organ for getting rid of effete mate- rial, 380. sensitive to surrounding atmosphere 384. ^ structure of, 372. true or derma, 374. Sleep, influence of hunger on, 484. proper amount of, 704. Small-pox, 304. breeding-places of, in the body, 311. cleanliness during epidemics, 340. contagion, sources of, 311, 313. " modes of conveyance, 312. " duration of, 313. contagiousness, period of, 321 , description of, 304. disinfection, 329-337. 290 INDEX. ^'"^"^327,146.°^ authorities regard- incubation period, 320. influence of climate on, 177 laws regulating, 345. ™o2e,''32.S ** '"^^''"""^ as severe notification of cases, 327. precautions against, 323-346. premonitory symptoms, 397. ' vaccmation.to prevent, 339. hmees instrument for collecting mois ture of the air, 163. .Smut in flour, 448. Soda, antidotes for, 729. bodium for tissues, 408. Soils, absorption of water by, 191 chemical composition of, 183 configuration of, 185. nlth-saturation of, 213. first turning up of, 180. garbage-made, 190, 220. ground-air in, 188, 189, 213 ground- water, 193. neat-retaining power of, 195. niechanical structure of, 184. of house-yards, 208, 213, 216. polluted by sewage, 213. P''^^*"*j«n8 against emanations from, sick^ness diminished by drainage of, "^186 ^^^^^ ^^^ ^"" """"^ ***g'^'^*es, water in, 191, 193. Solutions for water analysis, 553 Spectacles, 598, 602, 624. Spinal deformities, 651, 652. Spint-of-salt, antidotes for, 729 Splints, 735. Spring-watermost wholesome, 531 Squinting, 605, 608, 620. Stallard's double ceiling, 111 Starch, digestion of, 419, 464, 480 Starches, or carbo-hydrates, 419. Statesmansyear-book,statisticsfrom.3 Statistics of alcohol, 515, 516. of the British army, 8, 9. II Dublin institutions, 68. It cities, and typhoid fever, 12 II cities in which the death-rate has been reduced, 13. English, 3. in India, 8, 515. in the West Indies, 9, 10. Statistics, occasional fallacies of. 16 Ontario, 6, 7, 12, 14, 16. 67. of typhoid fever in Canadian and iiuiopean cities, 12. Steamboats an Sunlight, 169-174. Sunstroke, 723. Swallowing, mechanism of, 472-475 Symptoms of Asiatic cholera, 307 of chicken pox, ,303. II diphtheria, .301. II itch, .308. II measles, 298. II ringworm, 309. , II rotheln, 300. i II scarlatina, 299. ' II small pox, 304. II typhoid fever, 306. II varioloid, 305. II whooping cougli, 302 premonitory of infectious diseases Syphoning of traps, 25r. INDEX. 291 cies of, 16. ;, 67. 'anadian and dness, 6.S0. eyea, .594. i, paqe ii. >l.'i 519-524. 497. lents on, 507. ■1 overwork, of, at death, it, at death, i9. tes for, 729. 'eat-glands, >, 3.%. 70. ^72-475. , 307. diseases Taenia mediocanellata, 442. solium, 442. echinococcus, 442. Tanks for water, 5.%, ,5.S7. polluted by sewer gas, 229. I! 1. ('.eposit, 5.S9. for sewage, 277, 280. for intercepting sewage, 277. supplying water closets should not supply drinking water, 267. Tartar emetic, antidotes for, 729. Teachers should practice total absti- nence, .'517, 518. statistics of consumption in, Iti, 07. vital statistics of, 16, 67. Teas, adulteration of, 453. Teeth, description of different va)ieties of, 466. care of, 483. eruption of, 468. structure of, 470. Temperature, adaptation of the body to extremes of, 385-388. of air, 140, 156, l.')8, 162, 168, 658. of baths, scale of, 397. of the blood, 17. of the body higher in the morning, 400. extremes endured, 16.3-168, 385-.388. general principles regarding changes of, .393. SL'dden changes of, 168, 390, 393. less safely borne by persons debili- tated, intoxicated, or accustomed to great heat, 390-392. Tests (see Chemical). Test types (also see paije 271), 603. Therniometers, 140, 156, 658. dry and wet bulb, 1.57. Thirst, sensation of, 462. Tight-lacing, 360. Tiles for sewers, qualities of, 244. Tobacco, habit should not be indulged in, 521. injurious, 519. persons who habitually u.se, 520. poisonous symptoms from, 52"?. Tobin's tubes, 109. Toronto Asylum, remarkable instance of sewage pollution in formeotimes, ! 217. \ Toronto sewerage and typhoid fever, 12. I "Traps," 2.53-262. absorption of oontent-s of. 261. ■ disused, danger from, 260. "Traps," emptying of, 253, 259, 260. forcing of, 257. for gullies, (Juerin's, 258. syphoning of, 258. Treacle, composition of, 427. Trembles, or milk-sickness, 440. Trichinosis, 441. Tuberculosis from food, 440. Tubular wells, 534. Turnips, composition of, 427. Type, necessity for good, 623. Typhoid fever, breeding place in the body, 311. caused by emanations from sewage, 212. caused by sewer air drawn into water pipes, 229. causes of increase of, 11. cleanliness required in epidemics of, .340. comparison of, in Dantzic, London, Toronto, and other European and Canadian cities, 12. contagion, sources of, 311. II modes of conveyance of, 318, 34.3. disinfection, ,329-337. incubation period, 320. laws regarding, .345. notification of cases, 327. precautions to prevent, 323-346. reduction by improved sewerage and water supply, statistics of, 12. Ultimate disposal of sewage, 279-284. Urinals, 276. Vaccination, 339. Vancouver's Island, climate of, 204. Variola (see Smallpox). Varioloid, 305. Varley's cornice, 113. Veal, composition of, 427. Vegetation, influences of, 180, 187, 196. Velocity of the circulation, 30. Ventilation, artificial, 116, et ifeq. by combined extraction and propul- sion, 123. by diffusion, 95. by extraction, 117-121. by propulsion, 122. by t'le action of winds, 96-101. by che Galton grate, 137. >-y windows, 88, 89. wn INDEX. Walking, 668. Waring, Col Geo. jun., 252, 262 Warming, '25-140. i^*'"i!^l°''' '■^'^"ction of death-rate in, 13 VVash-basina in schools, 610, 649 Waste material in the blood, removal of, 395. Water, analysis of, 546-563. action of plants in tanks, 537. boiling, exposure to air and other means of purification, 579. chemical examination of, 546-563 classification cf 549, containing la. ^ amount of salts value of, 662 ' containing an f^s p.a ..-^ E.'t>;t'.3 and nitrates, vali'.> -f, C'ii. V«»iMilaUofl, characteristica of a well ventilated room, 158. O.WWK ;/flf .1 in imj)roving, 100. Wfcjuli of pr,-««uie of wind on, 101 •''*"l"i»t»on »f euflicieiicy of, 142- in cold weather, 85. inlets, cliaracter of, 87 natural, 94, ct anq. of drains and sewers, 221-2''8 289 of ships, 102. ' ^■ openings, position of, 83-86. II in summer, 84. II in warm weather, 84. II in winter, 85. II size of, 82. outlets, characters of, 90-92 power of diflFerent stoves for^ 1.35 II II jacketted stove for, 136 practical application of tiieoret'ical statements, 104-115 relative values of different methods. Vents for traps, 257-262. VibrforSs* ^"""^ "'^^^'""' "f- 257-260. Villi of the intestines, 482. Vinegar, adulteration of, 457 Vision, defects of, 595-604. single, explanation of, 594 Vital statistics (see Statistics). Vitriol, oil of, antidotes for, 729 Vogel's lactoscope, 447 Vofce, 685. ^ Water, contamination by animal anH v.. «etable substances, 666 . ", .. ", effects of, 566. distiiJ^ution of, 6.S9. entozoa or paiasites in, 667 excretion promote.l by drinking, 526 filtration of, 571-578. ^ forming^an opinion of the character for schools, drinking-water, vessels wells, simple test for pur'ity, S!,' freezingdoesnotrenderharmless,580 fre^lj^supphes, of from aqueous vi^ from graveyards, 666. f-^^" , " ^°-^ effects of, 566. from marshes, 566. from ponds, 532. injurious effects of hard, 564 in soils, 191, 193. Ill the body, uses of, 412 "'533""' "*'''' *° ^^ contaminated, lead in, 536, 538. II effects of, 565. 2'oj; sr""'''' '^^^'^ °^' «««• • of brooks, 5.32. of lakes, 532. of ponds, 532. of rivers, 532. of streams, 532. physical examination of, 540-645 pipes for distribution of, 538 plants, influence of, 537 polluted by air drawn in through closet pipes, 229. ** polluted by sewage, 214. provision for storage of, '636 '";io;:d"568.'' '^""^ ''""^p^- «- qualitative analysis of, defined, 5^0 qualitative analysis, test tub. -.. paratus, test solutions for, 55 . r qualitative examination of, for am- monia, nitrites, chlorides, organic 654-566"'°°' P""=*''=''' deductions, quantitative analysis of, defined quan^ty per head per diem required, rain as it falls through the atmos- phere, 530. animal and 16. of, 560. •67. inking, 626. le charactej ier, vessels, Jurity, etc., rmles8,580. eous vapor, cts of, 566. INDEX. 64. laminated, of, 665. )-545. S. through )leB em- Bd, 550. ibf .")•• '5 '..";, for am- organic uctiona, iefined, quired, atmos- Water, sediment In, whether injurious or not, 561. settling of turbid, 509. sewagf' contamination of, 635. stanilai.l of purity pf, 548. Htor igi, of, M6. 8 loatan ( r i Uded to purify, 570. sufiicientsupply of for sustaining life, 5 5. •8ui>ply improved, statistics of re- duction of death-rata owing to, -tanks, 636-539. test paper for, 564. test solutions for, 553. tubular wells for, 534. turbidity, color, sediment, taste and odor of, 541-545. Water-closets, 264-268. and urinals should have special tank. 229, 207. kind recommended, 266. outdoors, 268. pollu+,ion of drinking-water by, 229. principles to be observed in construc- tion of, 265. Water on the brain, increase of, 706. Waters of streams, lakes, and ponds vary in purity, 532. Watson's tube, 115. Wax in the ear causing deafness, 643 Weak sight, 604. Wells, contamination of, 533. open, superiority of, 581. polluted by sewage, 214. tubular, 634. West Indies, statistics of, 9, 10. Wheat flour, composition of, 427. Wheat flour, impurities and adulter*. ations of, 448. Whiskey, antidotes for, 729, White fish, composition of, 427. Whooping cough, breeding places of, in the body, 311. contagion, sources of, 311-31.!. It modes of conveyance of, 312. contagiousness, period of, 302. description of, 302. disinfection, 329-336. duties of school authorities and others regarding, 340. incubation period, 320. isolation, 324-327, 338. mild case as infectious as severe one notification of cases of, 327. precautions to prevent, 32:i-3iC,. premonitory symptoms of, 297. Wind in ventilation, 90-101. velocity of, 97. ^inds, influence of, on health, 197. of Bise, or northeast, 198. of east, 198. of Mistral, or north-west, 198. of Simoom, 198. of yirocco, 198. on spread of epidemics, 197. protection against, 196, 357. Windows, proper positions for, 612 -615 ventilation by, 88, 89. Worry, efiects of, 697. Zymotic diseases (seoMalaria and Infec- tious diseases collectively and by specific names), action of sewage in causing, 212.