UNIVERSITY OF CALIFORNl AT LOS ANGELES

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Larry Laughlin

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MILITARY HYGIENE

THE ELEMENTS OF MILITARY HYGIENE

ESPECIALLY ARRANGED FOR OFFICERS AND MEN OF THE LINE

BT

P. M. ASHBURN

MAJOR, MEDICAL CORPS, U. S. ARMT

g5^^aas5

BOSTON AND NEW YORK HOUGHTON MIFFLIN COMPANY

COPyiUGHT, 1909 AND I915, BT PKRCY M. ASHBURN ALL RIGHTS RSSERVED

600

1915 PREFACE TO THE SECOND EDITION

Since the first appearance of this book there has been a notable and gratifying increase in the interest that line officers and men have manifested in matters of hygiene and sanitation, and a corresponding increase in the effectiveness of disease - preventing measures. That this improvement has occurred is not necessarily ^ evidence that the book has been instrumental in bring- < ing it about, but expressions of opinion from various SB officers have led me to think it a possible factor, and z have in that way encouraged me to revise and in parts rewrite it, while a supplementary chapter has been added, in the belief that interest in the subject entitles the reader to a knowledge of advances more recently made, and in the hope that such interest and the use- fulness of the book may ba increased. December 8, 1914.

C3

3

346655

PREFACE

There can be little or no doubt that the sanitation of the army would be greatly improved if line officers and enlisted men should become more interested in the subject, and cooperate more freely and intelligently with medical officers in the efforts to promote it.

This book is written in the hope that it may both inform and interest them and so gain for the medical officer the sympathy and cooperation that he always needs, but now too seldom has. It is also hoped that medical officers themselves, especially those of the volunteer service and militia, may find the book useful in their dual capacities of administrators and teachers.

CONTENTS

PART I.— THE RECRUIT AND HIS ENVIRON- MENT

I. The Recruit 3

II. Personal Hygiene 20

III. Foods and their Preparation . . .32

IV. The Hygiene of the Barracks . . 54 V. Camps 73

VI. The Hygiene of Moving Troops . . 103 VII. The Hygiene of Hot and Cold Climates 122

PART IL — THE CAUSES OF DISEASE

Vni. The Remote or Predisposing Causes op

Disease 147

IX. The Immediate or Exciting Causes of

Disease 162

X. Disease-Carriers 187

PART III. — THE PREVENTION AND CONTROL OF EPIDEMICS

XI. The Defenses against Disease in General 207 XII. Diseases due to Infection through the

Alimentary Tract .... 223 XIII. Diseases due to Infection through the

Respiratory Tract ..... 255

viii CONTENTS

XIV. Insect-Bobnb Diseases 275

XV. Venereal Diseases 312

SUPPLEMENT

XVI. The Prevention of Mental and Nervous

Diseases 335

Index . . . . , . 345

PART r

THE RECRUIT AND HIS ENVIRONMENT

•• Health and a good constitution are better than all gold ; and a strong body than wealth without measure."

EccLESiASTicus 30 : 15.

MILITARY HYGIENE

CHAPTER I

THE RECRUIT

One of the principal factors in military hygiene is the individual soldier, or, as he comes from civil life, the recruit. If he enters the service in good physical condition, in good health, and with sufficient intelli- gence to apprehend and apply the instruction he re- ceives in military hygiene, the problem is almost half solved. The final acceptance or rejection of recruits now rests almost entirely with medical officers ; but in cer- tain ways line officers exercise a considerable influence in the matter : in the acceptance at the recruiting station, and in requesting special authority to enlist because of special qualifications. For these and other reasons it is important that they should keep well informed as to the requirements necessary and the qualifications desirable in recruits. We will therefore briefly consider some of these. The age limits for first enlistments are from eighteen to thirty-five years. Preferably men should be chosen between twenty-three and thirty years. Be- fore the age of twenty-three years most ° men are immature, their muscles are not hardened, their hearts not so strong, their minds not disciplined by expe- rience, their appetites and emotions not under control ; while their susceptibility to impressions from their en- vironment is such as to make it undesirable to limit their associations exclusively to adult unmarried males.

4 THE RECRUIT AND HIS ENVIRONMENT

After the age of thirty years the man's habits of body and mind are fixed, he takes instruction less readily, his body may have begun to deteriorate, particularly if it has not been well cared-for, and, in many instances, he seeks the service as a refuge, after failing in other walks of life. Many good men may be obtained before the age of twenty-three and between the ages of thirty and thirty-five, but in general the case is thought to be as stated.

The size of the recruit is not a matter of the great- est importance, provided that the development is nor- mal and the man strong and active, except as it applies to assigning him to duty. It is obvious that a very large and strong man is better suited for coast-artillery work than for the cavalry, and that a small, wiry man is in that respect better for the cavalry. The proportions of weight and chest measure- ments to height are published from time to time in general orders, and those proportions usually represent very well those of strong, well-developed men. An in- crease of weight, if associated with great breadth of shoulder and large chest measurement, is not necessarily harmful, being usually indicative of strength and en- durance. The sturdy, stocky Japanese coolie exemplifies this. Obesity, whereby the man is burdened with his own weight, is of course objectionable.*

^ The following table copied from the Medical Record of September 5, 1908, and compiled from the data of the Mutual Life Insurance Co. of New York, by its Chief Medical Director, is interesting as indicat- ing somewhat " the influence of overweight and underweight on vitality." The weights considered normal by the insurance company are some- what in excess of those prescribed by the War Department, the in- crease averaging about 10 pounds at the ages 25-29, and for height*

THE RECRUIT

The chest should be freely mobile, that is, both sides should move freely, symmetrically, and equally, in ex- panding and contracting. The measured chest expansion should generally corre- spond with the figures published in the general orders; yet it should be remembered that one man with very ordinary lung capacity may, by use of the shoulder and

below 70 inches. A weight 20 per cent below the average is considered " underweight," and 20 per cent above the average, "overweight."

Table showing the Percentage of Deaths in all Classes, and some Indi- vidual Diseases, among Overweights and Underweights, and the General Experience of the Mutual Life Insurance Company.

Causei of Death.

Over-	Under-
weights.	teeightt.
9.67	9.28
4.00	3.06
1.27	1.21
1.47	2.04
13.07	24.59
2.93	16.98
4.40	5.57
3.40	0.65
19.08	12.16
14.14	8.47
1.80	0.84
16.01	11.69
12.94	8.54
8.54	15.78
6.87	12.34
10.61	8.54
3.47	0.65
12.01	7.42
11.07	5.30
1.20	0.47
None	2.04
7.07	5.57
4.20	3.43
2.87	2.14
2.60	2.50

General Experience,

Class I. General Diseases — Acute . .

Typhoid fever

Malarial fever

Influenza

CImb II. General Diseases — Chronic

Tuberculosis

Cancer .... ...

Diabetes

Class III. Diseases of the Nervous System

Cerebral Congestion and

Hemorrhage, Cerebral

Softening, Paralysis . .

General Paralysis and other

forms of mental alienation

Class IV. Diseases of the Circulatory

System

Organic diseases of the heart Class V. Diseases of the Respiratory

System

Pneumonia

Class VI. Diseases of the Digestive Sys- tem

Cirrhosis of Liver .... Class VII. Diseases of the Genito-urinary

System

Bright's Disease and Nephri- tis

Class IX. Diseases of Skin and Cellular

Tissue

Class XI. Old age

Class XII. Violent causes

Casualties

Suicides

Class Xin. Ul-defined

8.90

3.94

1.24

1.00

19.56

12.42

4.18

1.25

17.44

12.32

1.30

1185 10.76

11.86 9.03

10.19 1.00

8.78

6.66

0.50 1.50 7.42 6.21 2.20 3.98

6 THE RECRUIT AND HIS ENVIRONMENT

back muscles and retraction of the abdomen, show an apparent expansion of 3^ inches, while his companions with a capacity as great, may, through ignorance of tricks or of what is desired, show only 1| inches. It is desirable that the chest be fairly large, to afford ample room for the free working of the heart and lungs, as on such finally depend both strength and endurance. A generally well-developed and strong man will show well-developed and prominent chest muscles.

Certain types of chest frequently indicate a predis- position to, or the actual existence of, disease, and de- mand careful consideration even when not constituting actual causes for rejection. The long, narrow chest, with prominent or " winged " shoulder-blades, depressed or flat below the collar-bones, and forming an acute angle at the divergence of the ribs below the breast- bone, frequently marks a predisposition to consumption,

A large, barrel-shaped chest, as deep from front to back as transversely, and showing a relatively small movement, is often associated with emphysema and asthma.

A chest more prominent on one side than on the other is apt to be associated with curvature of the spine, or old or chronic pleurisy.

Marked prominence or depression of the breast-bone, especially if associated with "beading," or lumps on the ribs near the breast-bone, frequently results from rickets, and may be accompanied by other bone de- formities.

The abdomen should be well muscled, and firm when

... the applicant is standing. It should move

easily and naturally in respiration, should

not be pendulous, and should be firm, particularly in

THE RECRUIT 7

its lower parts, just above the groin. "Weakness here will be indicated by a bulging if the patient strains, as at stool, or if he stands on his toes and coughs hard. Such bulging, especially if it be marked or shows a tumor-like swelling, indicates a predisposition to, or the actual existence of, a hernia.

The umbilicus or navel is another frequent site of hernia, and should be noted in that connection, as should any abdominal scars resulting from operations, as for appendicitis. Another, though less frequent, site of hernia is the femoral. This is shown by a fullness or swelling in the lower part of the groin, in the high- est part of the thigh rather than in the lowest part of the abdomen.

Large masses or tumors that can be felt through the abdominal wall, or that can be seen to produce in- equality or fullness, are causes for rejection.

Distention or prominence of the veins on the sur- face of the abdomen, or a varicose condition of them, is generally an evidence of impaired circulation or liver disease, and should cause rejection.

Hemorrhoids, or piles, while apparently not con- nected with the abdomen, are the result of distention of the rectal veins, and may be due to liver disease, to abdominal tumors, to constipation, or other intra-ab- dominal conditions. They are manifested as tumors, usually of a bluish color, within or about the anus, which vary in size from that of a small pea to that of a man's thumb. Of themselves they are not a cause for rejection unless of large size or producing symptoms, but their presence should always be noted. Internal piles are not visible, and usually make their presence known by burn- ing or irritation in the rectum, or by the passage of

8 THE RECRUIT AND HIS ENVIRONMENT

blood in the stools. In examining for them, note should also be made of other abnormal conditions of or about the anus, such as fissures or cracks in the skin and mucous membrane ; fistulas, little openings near the anus from which there may be a slight discharge of pus or fecal matter ; or abscesses or boils. Any of these conditions may so disable the man as to unfit him for service.

A history of abdominal trouble, such as severe indi- gestion» gallstone colic, vomiting of blood, should cause rejection.

The examination of the head is very important, as revealing defects in most of the special senses and as _, J offering important evidence as to the man's

character, habits, and abilities. The evi- dence on the latter points is to be gained largely from the shape of the head and the expression of the features, and, while such evidence is not always reliable, certain heads and faces are so distinctly indicative of stupidity or vice that there should be no hesitation in rejecting their possessors. Then, too, hideous or disgusting de- formities should at once cause rejection, for the sake both of the victim and those with whom enlistment would associate him, even though they are not of a character to incapacitate directly. The vision and hear- ing should be tested in strict accordance with the regu- lations governing the subject, and failure to meet the requirements is cause for rejection.

In addition to the test for vision, however, the eyes

should be examined for any signs of inflammation, red-

-j ness, watering, drooping of the lids, scars

or deformities, granulations, styes or boils,

undue prominence of the eyeball, inability to move the

THE RECRUIT 9

eyes in all directions, and discoloration or blurring of the cornea.

The ears, in addition to the testa for hearing, should be examined for any discharge, whether watery or puinilent, and if present it should be a cause for rejection.

The nose should be examined as to its freedom from obstruction, by having the applicant close first one side and then the other with his fingers and then breathe and blow through the free side. In- cidentally this may call attention to a foul-looking dis- charge or a foul-smelling breath, either of which may justify rejection. A sunken or much scarred nose is often an indication of syphilis, while a red, bulbous nose, even if not indicating alcoholism, is sometimes an indication of indigestion. It should be noticed that the man habitually breathes through his nose.

The mouth and throat should always be __ r n • J Mouth

carefully examined.

The condition of the teeth is the first point to be noted here. It is desirable that all should be pre- sent and good, but there must be at least . enough to permit of proper mastication of the food, and for this purpose at least four grinders are demanded, two above and two below, and so dis- posed as to permit their effective use. Enough of the front teeth should also be present to permit of the bit- ing of food and to preserve the symmetry of the face. At times men are accepted with no upper teeth, but wearing plates. This should only be done by special authority and in special instances. Insufficient or poor teeth are apt to produce digestive disturbances, partic- ularly on campaign, when hard bread may be issued,

10 THE RECRUIT AND HIS ENVIRONMENT

and when the preparation of the food in general may not be as good as in garrison. The examination of the teeth should not only relate to their presence and the presence or absence of cavities, but also to their state of cleanliness. Neglected, filthy teeth and gums may seriously menace the general health, while they cer- tainly predispose to loss of teeth, and, in many instances, indicate general carelessness or filthiness. Sores or ulcerations on the lips, tongue, gums, or inner sides of the cheeks should be carefully noted, as they may in- dicate syphilis or other general disease, and should at least lead to further and more careful search for syphi- lis. The same remark applies to milk-white patches, seen especially on the tongue.

In ill-kept mouths the gums may be spongy and bleed

spontaneously or on pressure, or pus may exude from

_, between them and the teeth ; or they may

be greatly retracted and expose the roots

of the latter.

In these and other cases the teeth may all be present, yet in such poor condition as to forbid proper mastica- tion, or to threaten their early loss.

The most common and easily detected throat trouble is enlargement of the tonsils. This condition usually __ indicates a liability to frequent attacks of

sore throat, and should always excite in- quiries as to this, and while not necessarily a cause for rejection, unless very marked, should be noted as a point against desirability. Ulcers, white patches, mem- branes, and an appearance of acute inflammation in the throat, should cause rejection.

Hoarseness, or loss of voice, or cough, should at least delay, and if persistent prevent, acceptance.

THE RECRUIT 11

Numerous scars on the tongue, lips, and cheeks, unless clearly and certainly accounted for other- wise, should cause rejection as being prob- °

ably due to bites during epileptic fits, or to syphilitic or other ulceration.

Too much importance should not be attached to a coated tongue, but a raw-looking, bright red, or tremu- lous one should direct careful scrutiny to the general condition and the habits.

Enlarged lymphatic glands, or " kernels," are most frequently noticed in the neck or under the jaw. They are frequently indicative of inflammation or » ulceration in other nearby regions, espe- cially the mouth or throat, and their pre- ^ sence should lead to careful examination for such con- ditions ; but at times their presence is indicative of a general infection, such as syphilis. Usually, if the en- larged glands are numerous, or the enlargement great, they constitute a proper cause for rejection. When the enlargement is localized at one part of the neck only, it points to an infection entering at a part near it. Thus such a gland at the angle of the jaw may be due to inflammation of a tonsil of the same side ; one under and near the jaw to a bad tooth, etc.

The scalp should be carefully examined as to its cleanliness and general care, for the presence of lice, which may be seen as such or may be re- • vealed by the " nits " or eggs, little whitish bodies attached firmly to the hairs ; for ringworm, scabbiness or scald-head, patchy baldness, wounds or scars, etc. The presence of vermin is a cause of rejec- tion in two ways, as indicating a lack of personal care, and as a danger to be introduced into crowded barracks.

12 THE RECRUIT AND HIS ENVIRONMENT

Superficial suppurative scalp diseases should generally cause rejection, as being contagious or as being caused by scratching excited by lice. Patchy baldness, if the patches are sharply defined and the skin is smooth, clean-looking, and not scarred, is apt to be harmless. If the skin is infiamed and scarred, and stumps of broken hairs are present, it should cause rejection. Ir- regular and incomplete baldness occurring in patches or tracts, giving at times a " moth-eaten " appearance, is most apt to be due to syphilis, and should cause care- ful examination for other signs of that disease.

The upper limbs should be examined as to their de- velopment and musculature, their free mobility in all joints and in all directions, the presence of all bones and joints, and a reasonable amount of dexterity and strength. Atrophy or wasting of a group of muscles or a part, inability to bend or make free use of a joint, and similar defects, should be carefully looked for, as they may otherwise be missed. Loss of one or more joints of a finger, swelling and deformity of a joint (baseball finger), or stiff con- tracted fingers are not uncommon, and, if in the fourth or fifth fingers, are not serious matters, though they should be noted. If in the second or third fingers, the matter is more serious, yet the applicant will usually be able to handle a gun and perform his other duties. Loss of a thumb is a serious defect, and in most instances would justify rejection. All deformities from badly united fractures or other causes should be noted, and should cause rejection unless the applicant can demon- strate his ability to execute the movements necessary in the performance of his duties.

The legs should likewise be examined as to their

THE RECRUIT 13

development, musculature, size, mobility, etc. The ap- plicant should be required to move all the t g^g ^j, j joints, to jump, hop, and otherwise demon- strate his ability to use his limbs. Marked deformities, such as clubfoot, shortening of one leg, stiffness, marked swelling or marked limitation of mo- tion in a knee or hip, should at once cause rejection. Less marked deformities, such as knock-knee, bow-legs, crooked shins, etc., need not cause rejection unless man- ifestly interfering with the free use of the limbs, or rendering the subject's appearance ludicrous or unmili- tary. Here, again, marked wasting of a part or of a group of muscles will often be found due to a joint lesion, a paralysis, or other nervous trouble, that would serve to disqualify the applicant. In addition to these defects, common to both arms and legs, the lower ex- tremities are subject to other affections rarely or never seen in the upper.

Varicose or dilated veins are often seen. They usu- ally show as swollen, bluish, and more or less tortuous vessels beneath the skin, and may be individually as large as a man's finger. They are most commonly seen on the lower legs, but are not very rare in the space be- hind the knee, and may extend up the inner side and front of the thigh to the groin. If marked, they should caiase rejection. If only slight, and in otherwise desira- ble applicants, they may be passed, but should always be noted. At times they cause the appearance and per- sistence of very chronic ulcers, which occasionally bleed, pain, or otherwise disable the man. Such ulcers are es- pecially apt to show on the front or to the inner side of the lower half of the leg. They are long in healing, are apt at any time to break open again, and when healed

14 THE RECRUIT AND HIS ENVIRONMENT

usually present brownish, discolored scars. Such ulcers, or such scars if accompanied by varicose veins, should cause rejection. The legs are especially prone to chronic ulcerations^ which may be caused by syphilis, tubercu- losis, leprosy, and other infections. In general these are causes for rejection.

A rough, nodulated, tender shin-bone is not an un- usual sign of syphilis.

The feet require particularly careful examination, as on their integrity, usefulness, and strength (or what we might call their durability) depends a large part of the man's capacity for " soldiering." The best known and probably the least important of the foot-ills is corns. They are best known because most persons at some time have at least one, and they are one of the least impor- tant ills because in most instances they cause not even serious inconvenience, and they usually disappear with the use of properly fitting shoes and ordinarily good care of the feet.

If numerous and painful, however, or if soft corns, situated between the toes, they may justify rejection.

Sweating feet, which soften, blister, redden, and burn, may cause rejection, as they are not apt to stand much marching.

Stinking feet may justify rejection in most instances, as constituting a nuisance in barracks.

Bunion, an inflammatory and deforming joint-afFec- tion, usually at the base of the great toe, will, if very marked, disqualify.

Hammer-toe, a condition in which a toe is flexed and the end presses on the floor, while a knuckle projects above, is very apt to cause lameness and may justify rejection.

THE RECRUIT 15

Overlapping toes may disqualify in a somewhat simi- lar manner.

Deformities of the arch of the foot are very impor- tant. It may be too high, so that the weight is borne on the ball of the foot and the heel, the intermediate parts remaining clear of the ground. This is a relatively rare condition, but may disqualify. A common condition is the opposite, ox flat foot ^ wherein the whole length and breadth of the foot touches the ground and the arch is almost or entirely obliterated. Such a foot in a white man is usually a poor marching foot, and, unless the applicant is a desirable man and states that he is a good walker, and that the foot never gives him trouble, it should cause rejection. When passed, its existence should always be noted, in case the man should be dis- charged for it later. The condition is more common but less important in negroes, but it may cause trouble in them also, particularly in the course of long marches.

Another type of weak foot is not really flattened but tends to rotate outward, thus bringing the inner margin of the foot nearer to the ground and more directly under the weight of the body, where a greater weight comes upon it, causing it to tire and eventually to break down and become flat. It may justify rejection.

The genitals should be well-formed and normal. Both testicles should be present and in the scrotum ; it should be possible for the applicant to ^^ retract his foreskin, and the penis should not show gross deformities, such as the opening of the urethra being placed far back from the end. Scars on the penis should prompt investigation as to their na- ture, whether syphilitic, chancroidal, or otherwise. The man should be required to express the contents, if any.

16 THE RECRUIT AND HIS ENVIRONMENT

from the urethra. Pus should at once cause rejection, as should any ulcers or sores on the penis, redness, puffiness, or signs of marked irritation about the urethra, or the presence of vermin, commonly known as crab-lice. Inflammation of the glans beneath the fore- skin, and venereal warts, while not in themselves dis- abling, will often justify rejection as capable of exciting suppurative buboes, and as resulting from venereal disease or uncleanliness, or both.

Buboes are swollen and inflamed lymphatic glands, and are found in the groin. They may be single or multiple, on one or both sides, and may vary in size from that of a small cherry to that of an orange. While not all groin buboes are venereal, the great ma- jority of them in applicants for enlistment are, and they justify rejection, even though the applicant insists, as he probably will if his venereal disease is not plainly evident, that they are due to " strain."

Varicocele is a condition of enlargement of the veins of the scrotum. It is most often found, and is apt to be most marked, on the left side. The condition frequently causes no symptoms, though it is often said to cause pain, and is apt to be pleaded as an excuse from arduous duty. If present, it need not cause rejection unless very marked or unless the applicant says that it produces symptoms, but when passed it should always be noted, and the applicant be made to agree to be operated upon if symptoms begin, or if the condition comes to interfere at all with his duties.

Hydrocele is an enlargement of the scrotum, usually on one side, caused by an outpouring of clear fluid into the membranous sac surrounding the testicle. It pro- duces a tense, painless, and often translucent swelling,

THE RECRUIT 17

which may at times be hard to distinguish from a tumor of tlie testicle or a hernia. Any one of the conditions, however, may suffice to exclude the applicant in time of peace.

While not much reliance can be placed on an applio cant's denial of venereal disease and his assertions as to perfect genital health, he should be questioned on the subject, and should be asked as to the frequency of urination and his ability to pass a good stream of urine. Dribbling or inability to pass a good stream, or to hold or control his urine, should cause rejection.

The skin will necessarily be noticed and examined during the examination previously described. One of the first and most important points to be «, . noted is its cleanliness. A dirty, foul, stink- ing skin usually indicates the type of man not wanted in our army, and it justifies rejection without further exam- ination. Certain men, however, appear with their skins soiled with sweat and dust simply because of lack of opportunities for cleanliness, and if their general appear- ance and their stories indicate that they are desirable men, they should be given an opportunity to bathe and then be examined. It must not be forgotten that a filthy man may bathe for examination, but reveal his usual habits by his linen. However revealed, filthy habits should cause rejection.

A skin showing the marks of severe and generalized scratching is usually indicative of disease or vermin infestation, and is therefore objectionable.

All forms of contagious skin diseases, such as ring- worms and syphilitic eruptions, should cause rejec- tion, or, in the person of an enlisted man, call for prompt treatment. As the line officer cannot be ex'

18 THE RECRUIT AND HIS ENVIRONMENT

pected to differentiate such affections, he will be on the safe side if he treats them all as suspicious, though he should if possible learn to recognize acne, the common " pimply" eruption seen on the chests, backs, and faces of many young men. It is usually not a severe affec- tion, and as it may coexist with good health and good habits, it should not cause rejection.

While a few men who are not really physically fit get into the service, there are a good many more who -,, are morally or mentally unfit, and they

are the men who later spend much of their time in the guard-house or who swell the number of desertions. Against this class of men the recruiting officer works at a disadvantage. Unfortu- nately, almost any man, no matter what his character, can get letters of recommendation, so that such letters are really of little importance, and the officer is forced to rely largely on his own ability to judge men by ap- pearances, — a notoriously unsafe thing, and an almost impossible thing for some individuals. Some aid is ob- tained, though, by attention to the applicant's general bearing, his facial expression, his quickness of appre- hension, the condition of his person and his clothing, and such evidences of alcoholism, venereal disease, good habits, and truthfulness as the examination may bring out. When a man declares that he never drinks, although his breath is strong with alcohol at the time, or that he has never had venereal disease, though he shows a scar on his penis and another in his groin, or has a suppura- tive bubo that he says is due to a strain, the inference is fair that he is a liar and undesirable.

Under our system of voluntary enlistment, and as long as there are plenty of applicants, it is better to

THE RECRUIT 19

reject all those about whom the officer cannot feel well satisfied ; and this whole chapter is based on such an assumed condition of affairs. In time of war, or when the supply of applicants for enlistment is not up to the demands, many men can be passed who would be ex- cluded under our assumed conditions ; but in all such cases they should only be passed by medical officers ex- ercising great care, and every defect should be noted, both as to its presence and its degree, as constituting a possible ground of application for a pension.

The man being in the service and any defect coming to his commanding officer's attention, he should be re- ferred to a medical officer to have it corrected if prac- ticable, but at any rate to have it noted, in the interests of justice to the man and to the government, and, if it be sufficiently serious, to have the man discharged before he breaks down in time of stress, with possibly serious results.

In this as in nearly all respects, the medical officer's duties can be performed more promptly and effectively if he has the cooperation of the line officer.

Official guidance in the examination of recruits is found in General Order 66, W.D., April 18, 1910, and in regulations and orders issued from time to time.

CHAPTER II

PERSONAL HYGIENE

The recruit having been accepted for the service in good health and good physical condition, it is his duty to himself and to his government to maintain those desirable conditions unchanged except for the better, if it be possible for him to do so. It will be possible in large part, if he is taught how to do it, and it is there- fore incumbent upon his officers to teach him at least the rudiments of personal hygiene, and those rudiments may be summarized as follows : —

First of all he must be taught the importance of au abundance of fresh air both day and night, as a health-giving, strength-producing, and life- prolonging measure. He must know that " colds," sore-throat, pneumonia, and kindred troubles are not caused by cold air, but by micro-organisms; that those micro-organisms are much more numerous and mucl^more apt to harm him in a warm, " close " room, with impure and rebreathed air, than in the open ; and that such diseases are more common in cold weather, ))aitly because in trying to exclude the cold, man is apt to include such air. The habit of breathing deeply and thoroughly changing the air in the lungs is imparted to him by his gymnastic and military drills, and is helpful. He should also learn early that his rest is important and should be taken regularly, in order to preserve his health and enable him, for that reason, to do without it more easily when the neces-

PERSONAL HYGIENE 21

sity arises. He should get eight hours of sleep in each twenty-four, while four hours more should be allowed for meals and short rests, changing of clothing, etc. In the remaining twelve hours he should do his work and his play. Regularity in rest and work is of great im- portance, and that is probably one reason that so many men improve rapidly in physique after entering military service. On the other hand, it is debilitating and de- moralizing to steal the hours from sleep for drinking and venery. It is desirable that the night's rest be taken in clothing different from that used in the daytime, and the latter should be allowed to air. Every man should possess and use night-clothing, and the not uncom- mon habit of sleeping in the underclothing should be discouraged. No man should have a " barrack odor " clinging to him, and, if ventilation and clothing are looked after, he will not.

The most beneficial exercise is that obtained incident- ally to work or recreation. Exercise taken purely as such is usually repugnant, and takes on the .^ aspect of work to men who feel that they already have an abundance of it. It should therefore be taken with some other incentive than is furnished by official orders. Baseball games, field sports, and other athletic competitions should be encouraged, and the effort should be made to interest and include all the men in them, and not merely a baseball nine and a few ex- pert athletes in each post. The objects to be attained by exercise are the increase of the strength of the heart and the capacity of the lungs (on which two depend en- durance, the increase of muscular strength, of nervous stability and control, of digestion and assimilation), and keeping the emunctories (the channels of waste excre-

22 THE RECRUIT AND HIS ENVIRONMENT

tion, such as the skin, kidneys, and bowels) active. No form of exercise at present encouraged in the army fails to promote some of these ends, so they are all good.

Cleanliness of person, clothing, and bedding should, and usually does, become a habit of life with the soldier ; _. .. but some men require much watching and admonition to make it become so, and fre- quent inspections should be made in order that the admonition may not be wanting. In general, it may be stated that dirty soldiers are either recruits or men who through drink or vicious habits have suffered in their self-respect. Body lice are rarely seen in our service except in guard-houses, where they may be in- troduced by captured deserters or other prisoners. Bed- bugs are occasionally found, and head-lice and itch infrequently. All of these pests should be carefully watched for and exterminated when found, as not only are they disgusting in themselves, and indicative of careless or filthy habits, but it seems quite possible that they may act at times as carriers of disease. Bed- bugs, when once introduced in barracks, are at times very hard to dislodge, particularly if the buildings are old and show many cracks in the walls.

Personal cleanliness should be understood as includ- ing the exclusive use of one's own linen and toilet articles. Disease may be transmitted readily by the indiscriminate or common use by several persons of the same towels, sponges, wash-cloths, combs, hair-brushes, shaving-brushes, etc. Some of the diseases which are most readily transmitted by these means are itch, ring- worms and other skin diseases, granulated eyelids, gonorrheal infection of the eyes, body vermin, and,

PERSONAL HYGIENE 23

occasionally, such infectious diseases as typhoid fever or smallpox.

It is not necessary that a man should bathe his body daily unless he is engaged in particularly arduous or dirty work, but he should bathe at least twice a week in summer and once a week in winter, and as much of tener as is necessary to keep his skin clean and free from all odor, especially from the feet, crotch, genitals, and armpits, and particular attention should be given to those parts. Once or twice a week, or oftener if necessary, the washable clothing, — shirts, drawers, and socks, — should be changed, and fresh put on. More frequent baths and changes do no harm, but should not ordinarily be demanded, except in the tropics.

The soldier cannot well give too much attention to his feet^ as he thereby keeps them in good condition and directly increases his value as a soldier. Any trou- ble with them should at once be corrected by the man, by means of bathing, clean socks, properly fitting shoes, proper nail-trimming and cleaning; or, if of a kind not corrected by such means, it should be reported to the surgeon.

The hands are not subject to so many disabilities as the feet, but they should be kept clean and sound, the nails clean and trimmed, and it should become a matter of routine to wash them before taking food, as diseases so diverse as lead-poisoning and typhoid fever may result from the neglect of such a practice.

The scalp should not be neglected in the general cleaning, and its cleansing is facilitated by having the hair short.

Bedding should be aired and bed linen changed weekly.

24 THE RECRUIT AND HIS ENVIRONMENT

The clothing issued by the government is nearly always of good quality, and is furnished in sufficient _. , , quantity to enable the soldier to be always

° comfortably, seasonably, neatly, and cleanly attired in a uniform and soldierly manner, and as much should always be demanded of him. He has to pay for his laundry-work, and he should have enough done to meet all the requirements indicated above.

The individual soldier has relatively little to do with the choice of his food, and the subject will be dealt _ . with at greater length in a later chapter.

° He has all to say, however, as to how he shall eat what is served to him, and he should be taught to avoid gluttony, to eat with an observance of the decencies, to chew his food thoroughly and eat slowly, to be as regular in his hours and habits of eating as his duties permit, and to avoid the use at meals of the enormous quantities of liquid, particularly coffee, in which he seems to find delight. A ])int of water may be taken with a meal without harm, but a pint of coffee is apt to cause some disturbance, while a quart is much more apt to do so ; and the fact that so little demon- strable harm does result is probably due to the good general physique and surroundings of the soldier. Many soldiers, especially young ones, are prone to indulge at almost every opportunity in the eating of fruits and pastries, with less regard to the quality than to the quantity. This tendency is lessened by a good company mess, and it should be discouraged as apt to lead to digestive disturbances.

Regularity of the bowels should, if practicable, be established and maintained by regular habits, good food, the use of fruits and bulky foods, such as vege>

PERSONAL HYGIENE 26

tables and oatmeal, and by exercise. Irritating or highly-seasoned foods should be used sparingly, if at all.

Among people of education and refinement cleanli- ness of the mouth is of course as much of a routine as cleanliness of face and hands, but persons whose education and rearing have been less carefully supervised are apt to neglect it, and recruits and occasionally soldiers from the latter class are at times seen with their mouths in a shameful state as the result of such neglect.

They should be taught (a) that such ailments as indigestion, toxic absorption, toothache, sore throat and sore mouth may result directly from such neglect, while many serious diseases are much aggravated by it, and (b) what will probably be more effective, that its existence is a mark of poor rearing and inferiority.

Every company commander should instruct his men somewhat as follows : —

1st. Every man should have a tooth-brush, and should so use it at least twice daily, and preferably oftener, as to remove from the teeth and gums all par- ticles of food or other foreign matter, brushing away from the gums and in all cracks and crevices.

2d. That he should after each meal remove from between the teeth, with a wooden or quill tooth-pick, or with a thread, any pieces of meat or other food, and not allow it to remain and putrefy.

3d. That he should promptly consult a dentist or a medical officer about any trouble arising in the teeth or gums. The medical officer can at least give him proper advice, and in many instances proper treat- ment.

.26 THE RECRUIT AND HIS ENVIRONMENT

Much harm is done by careless spitting, urination, and defecation in improper places, by men ignorant of _ the harm they may thus do. Because appar-

_ . ently healthy themselves, it does not occur r fl Of ^ them that they may, in answering a per- , fectly natural call, transmit disease to oth-

ers. Yet, as will be shown in other places, they may be giving off the organisms causing typhoid or other infections in their urine or feces, or those causing diphtheria, tuberculosis, or other disease in their spit, and such organisms may then soak or wash into the water-supply, or may be carried as dust or mud to the mouths, hands, food, or breath of healthy persons, and so infect them. Decency and patriotism should prompt a man to show as much regard for the health of his comrades as for his own.

The question of venereal disease will be dealt with in a subsequent chapter. Much of it could be avoided if the ignorance and misconception regard- _ ., ing sexual life could be dissipated. Every

man should know that sexual continence is compatible with perfect physical health, while its maintenance is far greater evidence of character and " manliness " than is the association with prostitutes, the abasement of virtuous girls, or the lowering, self- respect-destroying and demoralizing practice of mastur- bation. The sexual organs and sexual desire are placed in man that he may procreate and replenish the race ; but there is no physical penalty for his failure to do so, and the sperm necessary for the purpose will be dis- charged in sleep when it has accumulated sufficiently. " Wet dreams " and involuntary seminal emissions are not, therefore, necessary evidences of "loss of man-

PERSONAL HYGIENE 27

hood " or of any other disorder, but are seen to be the natural and healthy method of disposal of the sperm not used in the legitimate sexual intercourse of married life. Every normal man has periods of sexual excite- ment and desire, which constitute one of Nature's pow- erful influences in the perpetuation of the race; but self-respect should prompt and self-command enforce a determination that such desire shall not lead to acts that violate the laws of religion and society. These periods of excitement and desire can be made less fre- quent, and continence promoted, by the avoidance of fasciviousness in speech, conduct, reading, and thoughts, by thorough cleanliness and otherwise complete neglect of the genitals, and by a regular, sober, active life.

The habitual and excessive use of alcohol is every- where conceded to be harmful, while the moderate or judicious use of it excites much discussion, . . , ^ but is, in this country at least, falling into disfavor. Owing partly to the prohibition of the sale of wines and beer on government reservations, the con- ditions under which a soldier now indulges in alcohol are in most instances not conducive to " moderate " or judicious use of it ; so that, laying aside all theory, and dealing only with the condition confronting us, it is our duty to advise and encourage total abstinence in the soldier. This we may be able to obtain in certain instances, but it does not seem probable that it will be a universal characteristic of soldiers during the active service of the readers of this paragraph. We should, however, particularly try to inculcate it in the young recruit, as the man who does not begin to drink before he is twenty-five years of age is much less apt to become a drunkard or a habitual user than he who begins before

28 THE RECRUIT AND HIS ENVIRONMENT

he is twenty, and there is a good chance that, if he abstains nutil that age, he will always do so. On the other hand, the impossibility of knowing who are, and who are not, capable of using alcohol judiciously should prevent our encouraging what we regard as judicious use in soldiers. Every military post shows in its guard reports, its sick reports, and in unrecorded ways, the injury and loss of service resulting from excessive use of alcohol ; so that it is not necessary either to quote military statistics or to go to civil life for the lesson. However, the very nature of a soldier's calling so re- stricts his freedom of action, so excludes him from many refining and restraining influences, and so throws him in the way of temptation to drink, that we should highly honor him in the mass for his good conduct, and encour- age him in it as an individual.

If used at all, alcohol is preferably and least harm- fully taken with or after meals.

It will do little good to warn men against the use of strong alcohol, of flavoring extracts, bay rum, and wood alcohol, as only abandoned drinkers use such prepara- tions as beverages, and such men are not apt to heed the warning. However, it is important to know that wood alcohol and its preparations are more poisonous than ordinary alcohol, and that death, or complete and per- manent blindness, may follow their use.

Probably the least harmful and the most general of the so-called " bad habits " is the use of tobacco in one form or another. In our army the methods of using it are smoking and chewing. Of these chewing is probably the most objectionable as fouliniT the mouth and causing promiscuous spitting. Moderate smoking, indulged in after meals and in

PERSONAL HYGIENE 29

periods of relaxation, cannot be said to be very harm- ful, if at all so ; but smoking in excess may do harm by causing digestive, respiratory, and nervous disturbances, among which may be heartburn, headache, palpitation or irregularity of the heart, insomnia, tremor, cough, and hoarseness. Just what constitutes excess may not be stated, as an amount harmless to one man may be enough to cause injury to another. In general terms we may say that an amount causing any of the above-named or other symptoms in any man constitutes an excess for that man. As to the various methods of smoking, the same general principles apply. Cigar, pipe, and cigar- ette are equally harmless if not used to excess. The main objection to cigar-smoking is the expense ; to pipe- smoking, the irritation of the mouth, in rare instances eventuating in cancer ; and to cigarette-smoking, the habit of inhaling the smoke and thus exposing a much greater surface to the fumes, causing irritation of the vocal organs and the bronchial tubes, and the habit of rolling and smoking a cigarette at each opportunity, so that the total number consumed becomes excessive. The habit of smoking and the proper indulgence of the habit do the soldier so little harm and so greatly increase his comfort and contentment that they should not be inter- fered with. Stale tobacco-smoke in quarters, however, gives a very unpleasant odor, and the room should be daily opened and aired sufficiently to prevent or dissi- pate this.

There should be no necessity for telling men to dress properly for the season and the climate, but the neces- sity nevertheless exists, owing to the carelessness, igno- rance, or perversity of men. It is neither profitable nor wise for an officer to undertake to prescribe just what

30 THE RECRUIT AND HIS ENVIRONMENT

his men shall wear at all times, as men differ in their capacity to stand heat and cold, and one man may be able to maintain the highest degree of health *^ ' and comfort by never wearing flannel under- clothing, while his neighbor may promote both by wearing it the year round, and the rest of the men in the squad-room by wear- ing flannel in winter and cotton in summer. But men should be taught that exposure to either heat or cold lowers the resistance of the body and predisposes it to disease ; that body- warmth is promoted by woolen clothing and that linen and cotton make cool clothing ; that alcohol is not a fit substitute for an overcoat or a rain-coat ; that wet feet should be dried and dry cover- ings substituted for wet ones after marching or other exercise ; that good intentions or thoughtlessness do not justify reckless exposure to extremes; and that it is their duty to the government, as well as to themselves, to use discretion in dress and to try at all times to avoid sickness.

Exposure to strong sunlight is by some persons al- leged to be the cause of some of the evils heretofore credited to the heat of the sun, and it is further stated that these effects may be obviated by the use of hat- linings and underclothing of black, red, or orange, to exclude the actinic rays. However, rather extensive observations and investigations made by various work- ers in the Philippines have afforded little or no support for such assertions.

In all climates and at all times the dress should be comfortable, and should hamper the movements, espe- cially of the chest and abdomen, as little as possible. The equipment should be as light as circumstances will

PERSONAL HYGIENE 31

permit, should also be arranged with the idea of inter- fering with motion, particularly of the chest and ab- domen, as little as possible, but should contain the necessary articles.

While the government supplies the necessities of the soldier and supervises his hygiene to a considerable extent, it is seen already that the man himself is re- sponsible for much, and there are a few more golden rules that he should learn early for his own protection, and that will bear frequent emphasis and repetition, especially in campaign.

1. Be clean in person, clothing, and surroundings.

2. Eat no food but good food, and only with clean bands.

3. Drink no water from unauthorized or doubtful sources, unless it is boiled, — plain, or in tea or coffee.

4. Abhor, avoid, and destroy vermin, whether lice, fleas, ticks, flies, mosquitoes, roaches, mice, rats, or other varieties.

CHAPTER III

FOODS AND THEIR PREPARATION

It is now trite and partly true that " an army travels on its belly," and plainly evident that the health and happiness of the individual soldier depend very greatly on what he puts into his belly. This is a matter largely in the control of the company commander, and it is therefore important that he should have some know- ledge of foods and their preparation, and should pay great attention to mess-administration. Many company commanders do so, but others, knowing little of the subject, delegate the entire matter to their mess-ser- geants, who may know less, and the men suffer. The government ration and the regulations concerning its use are very liberal, and if a company does not have an abundance of good, nutritious, and attractive food, the fault is nearly always in its handling after it reaches the company.

Foods are of different classes, and a judicious and proper mixture of these is necessary for the classes maintenance of health and strength.

Proteids^ or albuminous foods, are the class repre- sented by the white of egg or lean beef. They occur also in vegetables, beans and peas being particularly rich in proteid, and this fact makes an exclusively vegetarian diet a health-sustaining possibility, which a proteid free diet is not. Animal proteid is more easily and com- pletely digested than that from vegetables, and to most persons is also more agreeable. An exclusive meat diet

FOODS AND THEIR PREPARATION 33

can maintain health and strength for long periods of time, and recent careful observations on the Eskimos of Disco Island in Western Greenland show that they maintain excellent health and nutrition on a diet almost exclusively of meat. " The physical endurance of Es- kimos nourished in this way is conspicuous, as is tlieir resistance to the rigors of the climate."

Fats are the class of food represented by the fatty tissues of animal bodies and the various vegetable oils. They are very valuable as foods, owing to their great fuel- value and the amount of nutriment contained in a small bulk ; but if taken in excess they are difficult of digestion and cause dyspepsia and diarrhoea. They are especially valuable in cold climates, a fact which we recognize in our practice of eating pork and other fat foods more freely in winter.

Carbohydrates are the sugars and starches, repre- sented by cane-sugar, fruit-sugar, and others, and by starchy vegetables such as potatoes and grains. For practical purposes we may say that the carbohydrates are of vegetable origin. Cellulose, as found in the husk and fibre of plants, is another form of carbohydrate, having a food-value for herbivorous animals but none for man. The carbohydrates have about the same fuel- value, weight for weight, as the proteids, and less than that of the fats. Starches may be taken in large amounts, but sugar, if taken in excess or in too con- centrated a form, causes dyspepsia and other disorders.

Inorganic salts, as represented by common salt and other salts contained in foods, have no fuel-value, but are necessary in maintaining the nutrition of the body, and the same is true in even greater degree of water.

Organic acids, flavors^ and condiments, as found in

34 THE RECRUIT AND HIS ENVIRONMENT

fruits, many vegetables, and in spices, are of value secondary to the preceding classes.

There is another class of substances that are not carbohydrate, proteid, nor fat, that occur in very minute quantities in foods, the existence of which has been known for only a short time, yet they are very important and their absence from the diet results in disease or death. These substances are spoken of as vitamines, and, while they are probably numerous, each appears to have a spe- cific value, in that its absence causes a specific disease. Among diseases caused by lack of vitamines are beri- beri and scurvy, rickets probably and pellagra possibly.

The vitamine that prevents beri-beri is found in very small amounts in meat and vegetables, in larger amounts in peas and beans. It occurs in rice but is there found only near the surface of the grain, in or closely adjacent to the pericarp or brownish colored outside of the grain. When the rice is highly milled and made white the outer layer of the grain with its contained vitamine is removed. Hence persons living principally on highly milled rice are subject to beri-beri, while others living on unmilled, hand milled, or undermilled rice do not have it.

Following the substitution of undermilled for highly milled rice and the addition to the dietary of " mongo " beans, beri-beri promptly disappeared from the Philip- pine Scouts, from Bilibid prison, Culion leper colony, and other places in the Philippines, and elsewhere.

Scurvy is caused by the lack of a vitamine that ex- ists in fresh meats, fresh fruits and green vegetables, but not in cured meats, in grains, dried fruits or beans, hence the former great prevalence of the disease at sea on long voyages, and in war, especially in besieged places. Guinea pigs can be given scurvy by feeding them for

FOODS AND THEIR PREPARATION 35

about a month on bread and dried mongo beans. On the other band a diet of bread and sprouted mongo beans protects and maintains them in good health.

Infants nursed at the breast or fed on raw milk do not have infantile scurvy. Fed on boiled or canned milk they are liable to it unless also given orange juice, meat juice, or other antiscorbutics.

For many years Voit's standard was taken as repre- senting the approximate amounts of the three main classes of foods necessary each twenty-four hours for the maintenance of health and vigor in the average working adult.

According to that standard the requirement was 118 grams of dried proteid, equaling about one ration of beef, 56 grams of fat, and 500 grams of carbohydrate, that is, of starch and sugar. The total value of this diet was over 3000 calories.

More recently, Professor Chittenden of Yale Uni- versity has shown that health, strength, and vigor can be maintained by many individuals on half the amount of proteid, without any increase in the fats or carbo- hydrates.

Meats are mixtures of proteids and fats, and contain water and salts also. They vary in palatability, cost, digestibility, and nutritive value ; but all •Mp'afa meats have nutritive value, though if dis- eased or decomposed they are not available for use.

In our service beef is the standard meat for issue, mutton, pork, fowl, and fish being substitutes issued only occasionally ; and, considering the cost, nutritive value, palatability, digestibility, tolerance, etc., it is the most valuable meat.

Mutton is almost equally valuable for nutrition, but

36 THE RECRUIT AND HIS ENVIRONMENT

many persons dislike the taste of it, and almost all tire of it sooner than of beef.

Pork is fatter than either beef or mutton, and is therefore much more used in cold than in warm weather. It is more difficult of digestion than beef and not so generally liked, though bacon is much used in the army and is a popular and valuable food, especially in the field.

Veal is seldom issued to troops. Its nutritive value is somewhat less than that of beef, and it causes diar- rhoea in some persons.

Fowl, as chicken or turkey, constitutes a special treat on national holidays and festal occasions. If freshly killed and healthy fowls are served, it is valu- able as well as appetizing food ; but when birds long kept undrawn in cold storage are issued, as is not in- frequently the case, their quality should be suspected and each bird carefully scrutinized, and, if of doubtful appearance or odor, rejected.

Fish vary greatly in palatability and nutritive value, but all of them keep poorly, especially if allowed to die slowly and if not packed in ice or frozen. The meat should feel firm to the touch, and not crush on gentle pi'essure. Dried and canned fish, as issued, are practi- cally always good, but they are not suitable for fre- quent or prolonged use, as men very soon tire of them.

Eggs consist of animal proteid and fat, and are classed with the meats. They are nutritious and usually easy of digestion. They may be cooked in a great va- riety of ways as a main dish, and are very frequently used in other dishes, such as puddings and cakes.

All meats should be eaten cooked, as proper cooking improves the flavor, increases digestibility, and destroys

FOODS AND THEIR PREPARATION 37

parasites that might otherwise cause disease in the eater. Among the disease-producing organisms which may be conveyed by meats but which can be destroyed by heat are : —

1. Tapeworms of various kinds, the three most com- mon ones being transmitted respectively by beef, pork, and fish, the meat in either case being " measly."

2. Trichina^ a species of larval worm which infests the muscles, causing great suffering, and, at times, death. It is conveyed to man by eating underdone pork that contains the parasites.

3. Tubercle bacilli^ the cause of tuberculosis.

4. Bacteria causing some animal diseases, which may reproduce the same diseases in man, or may merely cause intestinal trouble. Paratyphoid, a disease resembling typhoid, may be so produced, as may many so-called " acute food poisonings."

6. Ray fungus^ the cause of actinomycosis or lumpy jaw in cattle.

6. Typhoid bacillus, the cause of typhoid fever, may be conveyed in oysters or other shellfish coming from polluted waters.

7. The bacillus of anthrax, the cause of a very fatal disease.

8. The bacillus causing " trembles " in cattle and " milk sickness " in man.

Some diseases fatal to food animals do not affect man, and the flesh of animals dead of such diseases can safely be eaten ; but in general it is safe and wise to avoid all such meat, as, though the disease killing the animal may not affect man, chemical changes may have occurred in it to give rise to poisons, and ptomaine poisoning or *' meat poisoning " may result. Ptomaine poisoning may

346655

38 THE RECRUIT AND HIS ENVIRONMENT

also result from the action of bacteria contaminating the meat after death, or even after cooking, and causing changes in it. Such instances are seen when poisoning occurs from cold meat or hash cooked some days before use, or from canned meat taken from imperfect tins. When the ptomaine or other poisonous products oi bacterial action are once formed in the meat, they often may not be destroyed by cooking, and all such meats are dangerous.

Some few kinds of meat, principally fish, are poison- ous in themselves, and may cause death.

Meats are preserved for use in a variety of ways, only a small percentage of those furnished the army being used so soon after killing as not to require some form of artificial preservation. Of these methods of preserv- ing, cold is the most satisfactory and best keeps the meat unchanged, and by this means it may be kept for months. It is applied so as to freeze or merely to "chill" the meat, and its only effects are to render the flesh more tender and to detract somewhat from its flavor, particularly by causing an unpleasant change in the taste of the fat. Frozen meat may be kept indefinitely, but that which is merely chilled does deteriorate in time, becoming soft, slippery, and flavorless. It should not then be used as food. Cold cannot be depended upon to destroy the germs or parasites in meat, though keeping for a long time will destroy some of them.

Salting^ pickling^ and smoking are much used in preserving meats, particularly beef and pork, and the results are very good. Ham, bacon, and corned or smoked beef are excellent and palatable meats for oc- casional use, but they are not adapted to long use to the exclusion of fresh meats, and when they are so used

FOODS AND THEIR PREPARATION 39

the health is apt to suffer. These processes tend to free the meats from parasites, but cannot be depended upon to do so, and the eating of raw ham is dangerous.

Canning, with its attendant sterilization of the meat, preserves all of its nutriment and destroys all parasites, but it melts the fat, gelatinizes the gristle, and softens the muscle, so that the meat comes from the can less attractive to eye or palate, but it is good and valuable.

Preservation by means of drugs and chemicals, other than those used in pickling or salting, such as boric acid or formalin, is forbidden, and meat so preserved may cause sickness ; but for emergencies and occasional use it would not ordinarily do so.

It is not desirable here to consider in detail the vari- ous methods of cooking meats, but the company officer should exercise a certain amount of supervision in the matter, to see that his men's digestion is not injured by an excessive use of fried meats, that their appetites are not impaired by poorly prepared or poorly served roasts, stews, and hashes. A company mess is often good or bad as the cook knows, or does not know, how to handle, prepare, utilize, and serve meats. Rather com- mon faults in company cooks are as follows : —

Roast or baked meat is overcooked and dry, is taken from the oven an hour or two hours before meal-time and sliced, and is served with hot, greasy gravy to make it warm.

Tough ends, scraps, and bones are not utilized in making soup stock, as they should be.

Excessive fat is not rendered and utilized.

Hashes and stews are served with unnecessary fre- quency, and become monotonous.

Lack of imagination or lack of knowledge on the

40 THE RECRUIT AND HIS ENVIRONMENT

part of the cook and mess-sergeant result in lack of variety and attractiveness of the mess. Intelligent supervision of the mess by the company commander, the preparation of bills of fare in advance, so as to in- sure variety, and the study of good cook-books will obviate this.

The principal carbohydrate food is bread, and its importance in the mess is scarcely, if at all, secondary to that of meat. The ordinary supply of bread is issued as such, and its quality depends largely on the capacity of the post baker, notwithstanding his proneness to credit any defects in it to the flour, the yeast, the hops, or the oven. The materials supplied by the government are, with rare exceptions, excellent, and the failure to produce good bread is usually to be attributed to either the ignorance, the carelessness, or the uncleanliness of the baker. With the proper training of the bakers such failures will seldom be seen. Company cooks are permitted, and should be encouraged, to bake biscuit and muffins occasionally. They are somewhat more difficult of digestion than good issue bread, but are much liked and add to the attractiveness of the mess. Stale bread (that is, more than twenty-four hours old) is somewhat more digestible than fresh or hot bread ; but during the process of staling it should be kept covered and protected from dust, and should not be unnecessarily handled, nor by any but clean hands ; otherwise bac- teria and moulds finds lodgment and growth upon it and may produce disease. Toasting improves some breads and adds to their digestibility, but it is not often done in companies.

Pastries and cake are also bread, but are less easily

FOODS AND THEIR PREPARATION 41

digestible than the ordinary forms. They add much to the attractiveness of a mess and should be served occa- sionally. The same remarks apply to the various kinds of batter-cakes.

Comhread also makes a pleasant change from the monotony of baker's bread, and, as it is cheap, palat- able, and nourishing, its use is to be encouraged.

Corn-meal mush, with butter or milk, is also relished, and when cold may be sliced and fried.

Hard bread is issued only for field use. Good teeth are necessary for its utilization as issued, but it may be softened in hot water or coffee without impairing its value.

A measure of economy, sometimes ignored, is the utilization of crusts and fragments of stale bread in puddings, as meat-stuffing, and in other ways. Such practices add to the variety and attractiveness of the mess, and allow savings to be made in other direc- tions. To throw away such crusts because sugar and eggs are necessary in puddings and cost a little extra, is wasteful and wrong.

Vegetables supply all classes of foods, and are very important in the soldier's mess for this reason, and because they serve to impart variety and _- attractiveness to it. The most important . y^ vegetable issued (except wheat) is the po- tato^ which consists of almost pure starch. It may be cooked in a much greater variety of ways than is usual in most companies, and the company commander should see that such is the case. In whatever way they are pre- pared, potatoes should be cooked until soft or mealy, and should be served hot.

Rice is another valuable starchy food, and in some

42 THE RECRUIT AND HIS ENVIRONMENT

parts o£ the world it is the main article of diet; but in our country it is much less used and less desired than bread or potatoes. It is most popular with soldiers as a pudding, though it may be prepared in a variety of ways. It should be used to give variety and served in attractive forms, cooked with tomatoes or something else to take away its insipidity. Undermilled rice has a flavor superior to that of the highly milled and is also preferable, especially when used as a main article of diet, because of its content of vitamines that ai*e lack- ing from the latter.

Com is also to be classed as a starchy food. Ripe corn in the whole or the broken grain, as hominy or grits, is not so generally liked as the green, but it is very nutritious, and should be used occasionally as a principal dish.

Macaroni and other paste preparations are valuable foods, and admit of a variety of presentations, so that their use should be encouraged.

Onions are a staple article of issue, and are much used in the army. Their nutritive value is much less than that of the articles just discussed, but their flavor and the variety of ways in which they may be used make them very valuable. Monotony should be avoided in their use.

Tomatoes^ likewise, have relatively little food-value, but stand high for their flavor and the variety they afford. When they are served cooked, it should often be with some otherwise insipid food, such as rice, maca- roni, or stale bread.

Beans andj^eas, though possessing considerable starch, are the principal sources of vegetable proteid. They are both very attractive and palatable in the green state,

FOODS AND THEIR PREPARATION 43

and, though less nutritious than when ripe, add much to the mess. When dried, they are particularly valuable in making soup (for use in which ham-bones and rinds should always be saved), and when served boiled or baked, with bacon.

Beets are another valuable source of food, as they contain much sugar. They are also cheap, and are relished by most men.

Most of the common vegetables, as cabbage, greens, carrots, spinach, radishes, and cucumbers, have little nutritive value, but they add greatly to the attractive- ness of the mess and are also valuable in preserving health and preventing scurvy, and their use should be encouraged.

Their lack and the consequent occurrence of scurvy are apt to be matters of vital importance in sieges.

Salads are not used in company messes as much as they should be. They afford pleasing variety, and may be made to constitute an important dish, as « , , when composed principally of potatoes or salmon.

As issued in company messes, desserts are nearly al- ways very simple, and such is necessarily the case. When practicable, a dessert should be fur- nished once a day, and it may be made to use up otherwise unattractive articles, such as rice or stale bread made into puddings. Pies made of fresh or dried fruits are easy to make and serve, are inex- pensive, and well liked.

Milh and its products constitute important articles of food, though not entering so largely into «-.,. the soldier's dietary as they might. Milk contains all classes of food, — proteid, fat, carbohydrate,

44 THE RECRUIT AND HIS ENVIRONMENT

water, and salts, — though not in the proportions desir- able in maintaining adult life. Fresh milk is both more palatable and more wholesome than the canned or con- densed article, if its purity and freedom from disease- producing germs can be assured, but unfortunately this is not always the case. It should be borne in mind that many serious diseases may be conveyed in milk, among them tuberculosis, typhoid fever, dysentery, diphtheria, septic sore throat, and scarlet fever, — some of the dis- eases most dreaded in military life. Milk sickness, a disease now rarely seen, was also conveyed in that way ; while for many years the Mediterranean garrisons of the British army suffered very seriously from Malta fever, now known to have been transmitted by means of goats' milk.

In case of epidemic of any of the above-named diseases, the milk supply should be investigated, and this is particularly suggested by outbreaks of typhoid showing an explosive character, that is, epidemics in which many cases occur almost simultaneously. Because of this possibility of disease-production, milk whose origin and condition are not above reproach should be used in companies and post exchanges only in cooking or after boiling, and in camp or on the march men should be cautioned to the same effect, and warned against purchasing it by the glass from dealers or ped- dlers. Condensed or evaporated milk is more gener- ally used in companies than the fresh article, and it is on the whole probably safer, as the process of conden- sation and the subsequent prolonged storage tend to destroy disease-producing organisms. A can of such milk, when once opened, should either be used promptly or kept cool and protected from dust until used. Boil-

FOODS AND THEIR PREPARATION 45

ing water should be used to dilute it, to kill germs that may have settled and grown on it after the open- ing of the can.

Buttermilk is a valuable and pleasant drink, and where it can be obtained is much relished by the men.

Good butter is made from good cream and is every- where highly appreciated ; but unfortunately the good quality is not always obtainable, and much very poor butter is used in company messes. Oleomargarine is little inferior to butter in nutritive qualities and is to be preferred to poor butter, except that a prejudice exists against it in this country and men are apt to avoid its use. It has an advantage over butter in that it is not so likely to act as a carrier of disease germs.

Both are valuable fat foods as well as relishes, and should not be regarded merely in the latter light.

Cheeses are very concentrated forms of food, con- taining about one third proteid and one third fat, though the different varieties differ in the percentages of these. They make agreeable and valuable additions to the mess, but are seldom used in large quantities because they are apt to be difficult to digest, and to cause constipation. Ordinarily they are used in compa- nies rather as a condiment than for their food-values, though at times they may constitute an important part of a meal. In cooking, cheese is used principally with macaroni. Milk and cheese are liable to certain changes which cause the development of poisons, one of these known as tyrotoxicon, being very powerful and produc- ing severe symptoms or death. The ordinary souring of milk is not in itself dangerous, but may be beneficial in some respects. The justification for regarding sour milk with suspicion lies in the fact that the conditions

46 THE RECRUIT AND HIS ENVIRONMENT

favoring the development of the bacteria causing the souring may also have favored the development of dis- ease-producing organisms. Milk should be preserved either by refrigeration, to prevent the growth, or by heating, to kill, the contained bacteria.

For preserving other foods than meats and milk, refrigeration, canning, and drying are the three great commercial methods. Cold storage may pre- serve fruits and vegetables, as well as meats, eggs, and milk, practically unchanged for weeks, and immense quantities are so preserved and sold. Of even greater importance, however, is the pro- cess of canning, whereby the articles are cooked, ster- ilized, and hermetically sealed in cans or jars, to be preserved for months or years. This industry has in- creased enormously, and is now applied to almost all of the articles of food that have been discussed herein, and to a great number of others not so discussed.

The results obtained are excellent, and such foods are carried to all parts of the world and enjoyed.

Canned foods pall after a time, though, and should never, if it can be avoided, be used to the exclusion of fresh food. Otherwise nutrition may be impaired, and even scurvy may result. This may be because the heat necessary to preserve them destroys the vitamine that prevents scurvy. The fear of metallic poisoning from canned foods is thought to be exaggerated, and the probability of such poisoning to be remote, except where lead is used, and that is infrequent and does not apply to the great bulk of canned foods used by the soldier. Drying as a method of preservation is applied to fruits and vegetables, as well as to meats and fish. Desiccated vegetables find some use in the army, par-

FOODS AND THEIR PREPARATION 47

ticularly in Alaska, where they constitute a real bless- ing, but their use is not general.

Dried fruits, however, are everywhere used and with very general satisfaction. Dried apples, peaches, prunes, and raisins are issued or sold by the Subsistence De- partment, and make valuable and pleasing additions to the mess, where they are served stewed or in puddings and other desserts.

Sweets are much enjoyed by the men, and are valu- able for their fuel- value, and also, probably, as lessen- ing a craving for alcohol. Syrup and jam o-^eetg are articles of the ration that are much en- joyed, while the sale of candy by the Quartermaster's Department shows that its worth is recognized. As stated before, an excess of sugar causes dyspepsia and should be guarded against.

Coffee, tea, and cocoa are mild stimulants, but may almost as well be classed with condiments. Of the three, coffee is the only one extensively used in 5^^^-. our service, and it is often poorly made and _ ___ poorly served. The green issue coffee is of excellent grade, and if properly roasted and ground, and used fresh, is superior to most higher priced coffees obtained elsewhere ready roasted. The preparation of good coffee is simple and easy, but most company cooks do not practice it. The company commanders should make sure that, in addition to proper steps in prepara- tion, the following are observed : —

The coffee must not be long boiled.

The coffee-pot must be emptied and cleaned after each meal, and no coffee grounds should be used twice.

The sugar and milk, if the latter be served, should be put in by the user and not served alike to all.

48 THE RECRUIT AND HIS ENVIRONMENT

Enough coffee should be used to give strength and flavor to the beverage, and then but a moderate amount of it should be served to each man.

In the field, where the water is of a doubtful char- acter, the issue of large amounts of weak coffee is justi- fied, as tending to reduce the amount of unboiled water used ; but in posts this is not necessary.

Cooks will insist that the men prefer their coffee weak, long-boiled, and ready sweetened, just as they will say that they prefer roast beef overcooked, dry, and swimming in greasy gravy ; but inasmuch as most men in civil life like to exercise a choice in such matters, it is thought that a like privilege might be appreciated in the service.

It is also thought that perhaps the use of tea in the service might become more general if the beverage were properly made, and not boiled or steeped until a strong, black tannin solution results.

The following is a bill of fare for one week, which, it has been demonstrated, can be supplied with little extra cost beyond the savings on the ration, provided that the cook is capable and careful and the mess-ser- geant intelligent. Slight variations from week to week and to suit the seasons will permit such a bill of fare to be used for a long period and give satisfaction.

MONDAY

Breakfast : Stewed Fruit, Fried Eggs, Bacon, Bread, and Coffee.

Dinner : Roast Beef, Steak, or Meat Balls ; Baked Potatoes, Squash or Turnips, Stewed Tomatoes ; Pie or Cake.

FOODS AND THEIR PREPARATION 49

Supper : Cold Sliced Beef, Fried Onions or Toma- toes, Bread and Jam, Tea or Coffee.

TUESDAY

Breakfast : Bananas or Fresh Fruit, Liver or Kid- ney with Bacon, Bread, Butter, and Coffee.

Dinner : Beef Steak or Hamburger Steak ; Potatoes, Radishes, or Onions ; Pudding, Bread, and Coffee.

Supper: Cold Beef, Fried Potatoes, Bread and Jam, Tea or Coffee.

WEDNESDAY

Breakfast : Stewed Fruit, Fried Mush and Molasses, Coffee.

Dinner: Boiled Ham; Boiled Potatoes, Boiled Cab- bage ; Pudding, Bread, and Coffee.

Supper : Cold Boiled Ham, Bread and Jam, Butter, Tea or Coffee.

THURSDAY

Breakfast : Stewed Fruit, Puffed Rice, Wet Hash on Toast.

Dinner : Roast Beef, Steak, or Meat Balls ; Baked Potatoes, Corn, Squash, or Turnips ; Pudding, Bread, and Coffee.

Supper : Cold Beef or Hash, Bread and Jam, Fried Onions or Tomatoes, Tea or Coffee.

FRIDAY

Breakfast : Stewed Fruit, Oatmeal with Milk, Bis- cuits with Syrup and Coffee.

Dinner: Baked Fish with Sauce; Boiled Potatoes and Onions ; Bread, Butter, and Coffee.

60 THE RECRUIT AND HIS ENVIRONMENT

Supper : Salmon or other Fish Salad, Bread and Jam, Tea or Coffee.

SATURDAY

Breakfast : Stewed Fruit, Bacon, Rice or Corn Flakes, Toast, and Coffee.

Dinner : Baked Beans with Pork ; Pickles, Stewed Tomatoes ; Bread and Coffee.

Supper: Cold Beans or Bean Soup, Pickles, Tomato Catsup, Bread, Butter, and Coffee.

SUNDAY

Breahfast : Stewed Fruit, Oatmeal with Milk, Hot Biscuits, Coffee.

Dinner : Roast Pork, Veal, or Mutton ; Browned Po- tatoes, Baked Squash ; Apple Sauce, Pie or Cake.

Supper : Cold Meat, Bread and Jam, Tea or Coffee.

The Hygiene of the Kitchen From the hygienic and many other points of view the company kitchen is one of the most important places in the post, and the company cook a very important person.

These two bear a more direct relation to the guard reports, sick reports, and the general efficiency of the command than at first appears ; while the subjects of alcoholism and desertion are especially involved.

It is therefore an important part of the company com- mander's duties to see that both are as good as can be obtained. He should see, as stated before, that his cook is capable of preparing the food in attractive, satisfy- ing, and digestible forms, that he is economical, a good manager, and can utilize the ration in a variety of ways and supplement it judiciously. But the cook may fulfill

FOODS AND THEIR PREPARATION 51

these requirements and still do much harm by causing or spreading disease. Therefore he and his company officers should know something of the hygiene of the kitchen.

The primary and most important rule as to cook, kitchen, and the contents and surroundings of the latter, is cleanliness. All parts of the barracks and all persons therein should be clean, but the kitchen and the cook should excel. The cook should bathe often, change his clothing frequently, always wash his hands after a visit to the toilet, after handling anything dirty, and before handling foods. He should always have a clean hand-towel in his kitchen, and not use for the purpose either a dirty rag or his dish-towels. He should wear white aprons, caps, and clothing, and change them when soiled. His finger-nails and his hair should be kept short and clean, and a nail-brush should be in the kitchen for use and should be scalded daily. A cook who has had typhoid fever, or, rarely, one who does not know that he has had it, may, though appar- ently in good health, be excreting and distributing typhoid bacilli ; and a typhoid epidemic limited to a company should always cause this possibility to be investigated. Men who are dirty in their habits, who have syphilis, tuberculosis, or other infectious dis- eases, or who are persistent in unsanitary or careless methods of preparing foods, should not be allowed to cook.

The kitchen should be proof against the most rigid inspection for dirt. Some disorder and litter necessarily attend the preparation of food ; but this can usually be cleared up almost immediately, and it should not remain any longer than necessary. The meat-block, bread-

62 THE RECRUIT AND HIS ENVIRONMENT

boards, carving-tables, and all utensils should all be in- spected daily and all kept clean.

The ice-chest and milk-cans should receive special scrutiny, and should be clean inside and out, as evi- denced to the eye, the nose, and the white glove.

Foods like cheese, codfish, and bacon, that possess a strong odor and do not readily spoil, should be kept on shelves or in boxes, protected by wire gauze, rather than in the ice-chest. Canned meats, fruit, and vegetables should be used as soon as possible after they are opened, or emptied into clean dishes, and not left about in the cans. All food should be used before it becomes mouldy, sour, or decomposed, or should be thrown away, though a slight and recent growth of mould on the surface of ham, cold-storage beef, bread, jam or other sweets does not necessarily injure the whole, and may be re- moved.

The kitchen sinks should always be kept clean, and should be well trapped. Care should be exercised that grease, crumbs, and fragments are kept out of them, that the pipes may not become clogged. Kitchen waste, the scrapings of food from plates, and unused frag- ments should be thrown into covered cans, which should be emptied and cleaned once daily, and should not serve either as a breeding or a feeding place for flies, roaches, rats', or other vermin. Particular care should be exer- cised to exclude all such from the kitchen at all times. For this purpose cleanliness and screens should suffice, but if fly-paper, roach-poison, and rat-traps are needed, they should be supplied.

The kitchen police is usually supplied by roster from the company, but at times the work is given as a pun- ishment. This is undesirable. Instead of poor men.

FOODS AND THEIR PREPARATION 53

good ones should be put on kitchen police, and the work should carry with it immunities and privileges to make good men desire it.

Men who are sick should be excluded from duty in the kitchen. In 1909 the writer investigated an epi- demic of typhoid in a battery of mountain artillery at Fort D. A. Russell, and found that its spread was due to the fact that certain men were on duty as kitchen helpers at the time when they were in the early days of typhoid attacks. They infected their comrades by han- dling food that these ate.

CHAPTER IV

THE HYGIENE OP THE BARRACKS

Neither the enlisted man nor his immediate com- mander has very much choice in the matter of bar- racks. They are assigned to duty at a post where certain barracks are provided, and must of necessity make use of them. In one post the barracks may be new, large, and built with a view of affording all pos- sible advantages in the way of comfort, convenience, and sanitary arrangements. In another post they may be old, small, and apparently built without a thought of any of the advantages mentioned. In the one the capacity of the barracks may greatly exceed the size of the garrison, in the other, the reverse may obtain ; but in nearly all instances the conditions are controlled by military necessity and not by the company com- manders. It is therefore considered that the proper scope of this chapter is to indicate what is desirable, and to assist in making the nearest practicable ap- proach to it under existing conditions.

The buildings are apt to be of almost any material,

from brick, stone, or concrete, to nipa and thatch.

. Usually they are of substantial materials

and well constructed, unless designed for ings , . .

merely temporary use m warm countries,

when light board-structures or those of bamboo and

palm are used. In the latter class, cheapness of cost

is always a consideration ; but it is not to be carried

to the extent of making the structures unsanitary. Suf-

THE HYGIENE OF THE BARRACKS 55

ficient room should be provided, adequate and conven- ient supplies of good water, proper kitchen arrange- ments, and protection from mosquitoes, flies, and other insect pests. The structures should be sufficiently raised above the ground to prevent dampness, if pobsible, and ample provision should be made for the care of excreta, garbage, and waste water.

In permanent barracks of the newer type, provision has usually been made for the sanitary requirements, and the conditions are satisfactory where overcrowd- ing does not obtain. Barracks of concrete, stone, brick, or wood may all be satisfactory if other considerations are met. One of the first of these is location and ex- posure, and the desirable locations and facings vary with climate and local conditions.

In general, it is well to get much exposure to the sun in cold climates, and this is best accomplished by having the four corners of the main building point in the cardinal directions. In such places, however, the avoidance of prevailing winter winds may be of even greater importance, and may dictate a location. In any event, both sun and wind must be considered in their sanitary as well as their comfort-bearing capacities, the former as a great aid in cleanliness and disinfec- tion, the latter as a promoter of ventilation. In any climate, the structures should be dry as to both site and walls. Damp cellars and surroundings may be avoided by selection or by grading and drainage. Damp walls are avoided by having a damp-proof course, as of slate or concrete, above the foundations, by double walls with air-spaces, by good ventilation, and, where excessive or hard-driven rains obtain, by waterproofing with paint, etc. If the walls are continuously of porous

56 THE RECRUIT AND HIS ENVIRONMENT

brick or stone to the cellar, or to the surface of the ground, they will be continuously damp and chilly, in most climates, and only the insertion of a damp-proof course will correct the condition. If other considera- tions, such as size, ventilation, heating, or plumbing, are unequal, they should be allowed more weight, in governing the choice of barracks, than the structural material ; if all other considerations are equal, the structural feature should govern choice, usually in the following order : concrete, brick, stone, wood.

The buildings should be sufficiently large to provide abundant squad room, recreation or day rooms, store- _- rooms, kitchen, pantry, and dining-rooms,

small rooms for noncommissioned officers, tailor's, barber's, and cobbler's shops, a workshop for the mechanics, and ample water-closet and bathing facilities, unless a part of these are provided else- where.

The squad-rooms are the matter of greatest consid- eration, and they should be given first thought in selecting barracks. They should always be as large as it is possible to obtain, keep clean, and heat, and should provide a minimum of six hundred cubic feet of space and sixty square feet of floor-room for each man, exclusive of the room occupied by wardrobes and lockers. They should be well lighted both by windows and artificial light, preferably electric. The window- space necessary will vary with climate and location, but it should insure plenty of breeze in the tropics, and plenty of light in northern climates. If a good system of ventilation, other than by windows and doors, has been installed, so much the better, and it should be carefully studied until understood, and then kept in

THE HYGIENE OF THE BARRACKS 57

maximum working order. In all barracks, ventilation and heating are closely related, and should receive the company commander's personal consideration. If it be practicable, it is a great help in ventilating most barracks to have a small open-grate fire going all win- ter, but there is usually no provision for it. The air ia the squad-rooms should at all times be sweet and fresh, and free from the "closeness" and staleness that is particularly apt to obtain in the early morning hours of winter nights. The means of insuring this will vary in different places, but there is always one expedient that may be resorted to, — raising the lower window- sashes and fixing boards beneath them, with nails if necessary, so as to allow the air to enter in an upward direction between the two sashes. Inspections should be made occasionally, at the times indicated, to see that the air is good; while all arrangements to promote ventilation should be inspected frequently to see that they are in working order and have not been interfered with. In case interference is found, it is well to detail a man in each room to be responsible for their correct maintenance. All squad-rooms should be opened and thoroughly aired each day, in addition to the constantly working arrangements.

Always in the tropics, and during warm weather in other climates, all windows should be provided with screens to exclude flies and mosquitoes. If such is not the case, bed -nets must be used at night.

In cold climates double or storm doors and windows may be provided. They make the rooms more com- fortable and easier to heat, but should not be allowed to impair the ventilation.

Water-closets, bath-rooms, and wash-basins should

58 THE RECRUIT AND HIS ENVIRONMENT

be entirely away from the squad-rooms, in which no plumbing should show. Articles of food, dirty and wet clothing, and useless trappings should be excluded as far as practicable. Floors should be sprinkled frequently with wet sawdust, and swept so as to create as little dust as possible; and at least once a week the entire room and its contents should be so thoroughly cleaned as to pass the most rigid inspection, no dirt, dust, disorder, or vermin being anywhere present. This inspection will be made usually on Saturday, and should be pre- ceded by an outdoor airing of bedding and change of bed-linen on Friday. At the inspection all wardrobes, drawers, lockers, and boxes should be opened, and their contents exposed to view. The small spaces and corners about such articles, the space behind or under radiators, the tops of wardrobes and shelves, should all be examined, and, if any man seem unclean, his linen and person. It is not thought wise to subject intelligent and self-respecting men to such personal inspections as a matter of routine.

The day-rooms, or recreation-rooms, should be suit- able for their purpose, should have good light, good air, comfortable heating, and such provision in the way of chairs, tables, reading matter, billiard and pool tables, and other facilities for amusements, as will con- duce to the interest, instruction, and amusement of the men, or such, at any rate, as can be obtained.

These rooms should be kept clean and neat at all times, free from dust, foul air, dirt, and vermin. The care should be such as to enable them to pass the same general inspection as squad-rooms. Smoking will be indulged in, in recreation-rooms, at most times of day, but the rooms should be opened and aired frequently.

THE HYGIENE OF THE BARRACKS 59

Spitting will also be indulged in, and cuspidors con- taining water should be provided in sufficient numbers to prevent spitting on the floor, and any man then doing so should be punished. The cuspidors should be- emptied and scrubbed daily.

Pictures and ornaments may be permitted to some extent, to detract from the bareness and add to the cheerfulness of the room ; but, in general, unnecessary dust-collecting articles should be excluded.

The dining or mess room should be sufficiently large to seat comfortably at table at least ninety per cent of the command. A certain number of men will necessarily be absent from each meal, — on guard, in the kitchen, on pass or furlough, and for other reasons, — but pro- vision should be made for the maximum number that may be present. Lighting, heating, ventilation, and screening are all important here as in other rooms. Screening, particularly, should be carefully provided, and every means employed to keep the place free from flies. The cleanliness of this room should be as nearly perfect as possible, and while it is permissible to have the room attractive, dust-gathering trappings should be excluded. The mess-tables are used uncovered, or covered with white oil-cloth. The former is the prefer- able method, as it insures thorough cleaning and scrub- bing, if the tables look clean. An oil-cloth can be made to look almost or quite its best by a small amount of indifferent rubbing, though it really may not be free from grease and dirt.

As said before, the men should be required to ob- serve the decencies at table, and they are more apt to do so if the decencies are observed toward them. The table should therefore be orderly and attractive, though

60 THE RECRUIT AND HIS ENVIRONMENT

plain, the dishes and utensils should be perfectly clean and arranged in a proper manner, the food should be served in an orderly, attractive, and appetizing way, and with a sense of fitness. While parlor manners may not be expected in the barracks, gross indecencies of man- ner, speech, or action should be prevented. The room and table should be well cleaned after each meal, and the dishes and utensils should be carefully inspected daily and their perfect cleanliness assured. Once a week, or oftener, the tables and floors should be thor- oughly scrubbed with lye and water, and vinegar-cruets, salt-cellars, mustard-pots, etc., well washed and filled. In warm weather, fly-paper and, if necessary, occasional fumigation with pyrethrum fumes, should be used to supplement the screens.

No man should be allowed to eat with unclean hands, and it should soon be a matter of habit for all men to come to the table clean as to hands and face, and neat in appearance. Leisurely eating and thorough mastica- tion should be encouraged.

After the squad-rooms the kitchen is probably the most important room in the barracks. Its importance has been discussed elsewhere, but may be emphasized here. It should if practicable be a large room, well lighted and well ventilated, opening on a large porch, and connecting with store-rooms in the cellar or else- where convenient, and with a roomy pantry, with abundance of shelving and drawers, also well lighted and ventilated. Good tables, sinks, running water, ample drainage, sound and smooth meat-block, an amply large range, and abundance of good kitchen furniture and utensils should be provided. A large ice-chest and some screened shelving should be near at hand. It is

THE HYGIENE OF THE BARRACKS 61

desirable, if practicable, to have a large hood over the range, to catch and conduct away, through a ventilating shaft, the odors, vapors, and smoke arising from the cooking. All of these articles should be frequently in- spected to make sure that they are always cleaned as soon as possible after use, and never put away in any other condition. The cook, above all men in the com- pany, should live, think, and dream cleanliness, and he should be held most strictly to account for shortcom- ings in that line. The kitchen police should be re- warded for efficiency in such a way as to make the detail desirable, and in this way the kitchen should be made an object-lesson and a school of cleanliness. The inspection of the kitchen should include the pantry and ice-chest, should take note of, and remedy, waste or poor management, and should always embrace inquiries concerning, and search for, flies, roaches, mice, and other vermin. Cats, dogs, and other pets, as well as men not tliere on duty, should be excluded at all times. Garbage- cans should be outside of the kitchen, should be emptied at least once a day, and then cleaned inside and out ; otherwise they speedily become a foul nuisance.

The general remarks as to the lighting, heating, ven- tilation, and cleanliness apply to the offices and the shop-rooms for the baker, tailor, and cobbler, and the inspection of these latter should not be omitted, other- wise they are especially apt to form accumulations of scraps, dirt, and dust ; and they are especially favorable distributing points for vermin.

The company barber should be required to keep his brushes, combs, razors, and utensils thoroughly clean, and to sterilize them frequently. He should be obliged to keep an abundance of clean towels and aprons, and

62 THE RECRUIT AND HIS ENVIRONMENT

to be liberal in their use. He is not apt to be so of his own volition. He should be instructed not to shave or cut hair for men with skin diseases without first get- ting the surgeon's assent. Should his own skin or hands show disease, he should consult the surgeon.

Store-rooms do not need light, air, and heat in such liberal amounts as do living-rooms, but they should be dry, free from vermin, and should answer the purposes for which they are required.

Bath-rooms should be well drained, well ventilated, and well lighted, and when such is not the case every effort should be made to correct the condition. Lighting is facilitated and cleanliness promoted by having walls, doors, and partitions painted white. Where tubs are installed, they should be thoroughly washed and cleaned after each use, and the floor should be kept clean at all times. Each man should have his own soap and towels, and should take them to and from the tub with him. When tubs are not sufficiently numerous to accommo- date the men as they wish to go, they should be detailed by roster to bathe, at least once or twice a week, and as much should always be required of them. Shower- baths are much more economical of both time and water, and are installed at most posts. They, as well as tubs, should have both hot and cold water connections, be frequently inspected as to condition, and be kept scrupulously clean. The drain openings should not be allowed to clog with soap and hairs, and the entire bath- room should be scrubbed at least once a week, and as much oftener as is necessary to keep it clean and sweet- smelling, and free from mustiness. Gratings should be lifted daily if necessary and the space beneath flushed and scrubbed. The same general remarks apply to the

THE HYGIENE OF THE BARRACKS 63

bowls for face and hand washing. The stoppers for these, and the chains holding them, should always be clean, the outlet openings likewise, and watch should be kept to prevent the formation of a film or coat of soap and dirt inside the bowls. The throwing of to- bacco, paper, cotton, and dressings into bowls, tubs, or bath compartments should be forbidden and prevented. The man detailed in charge of the bath-room should be cleanly and trustworthy, and should have authority to enforce the rules.

The water-closets are frequently in close proximity to the bath-room, and if both are kept clean there is no objection to it. Flush-closets and urinals are installed in practically all posts now, and where such is not the case one of the various expedients for disposing of ex- creta in the field will have to be used, and reference is made to their description. Flush-closets should be kept clean at all times, the bowls scoured, and the seats wiped off occasionally with a damp cloth. The floors about them should always be clean, and the room should be free from odor. Standing on the seats, defacing or defiling them, throwing stiff paper, matches, and other things likely to cause obstruction, into the bowl, and writing obscenity on the compartment walls should be punishable offenses. When a closet gets out of order in any way, it should be put out of use until repaired.

It is to be borne in mind that the use of carbolic acid and chloride of lime is but rarely necessary about flush- closets, and then not for the purpose of destroying odors.

Constant bad odors indicate lack of care or poor plumbing, or both, and should be corrected. When concealed by other odors, such as those of chlorine or carbolic acid, they may not be noticed, but the evil

64 THE RECRUIT AND HIS ENVIRONMENT

condition of which they gave warning is unremedied. Tissue paper is issued for toilet purposes, and no other should be permitted to be used, as being apt to scratch or irritate the anus, and to clog the drain. By signs in the room, and by verbal instruction, the men should be taught to wash the hands after every visit to the closet. It should also become a habit for them to inspect their feces before flushing the closet, as disorders may thus be brought to their attention, and remedies sought. The passage of blood, pus, large amounts of mucus, or worms should prompt early consultation of the surgeon. The closet-rooms should be screened, and should be floored with cement to permit flushing, and to do away with cracks and crevices. Roaches and flies should be excluded. Each is indicative of unsatisfactory condi- tions. Urinals are ordinarily flush-bowls, for use by one person at a time, and should be sufficiently numer- ous to meet the demands of early morning and of the evening. The floor and walls immediately about them should be of smooth, hard, waterproof material, such as slate, and should be washed thoroughly each day and then lightly wiped with a moist rag sprinkled with kero- sene. Otherwise a crust of urinary salts is apt to form, and odors of decomposing urine to arise. When proper care and cleanliness are exercised, neither of these ap- pear, and the use of deodorants is not necessary. The flushing of the bowls is usually automatic, and should be of sufficient frequency to prevent deposition of salts, though its action should be supplemented by washing and scrubbing of the bowl. If the outlet of the bowl is not already screened, a piece of wire gauze should be placed over it and held in place by a small stone or other weight, otherwise it may get clogged with bits of

THE HYGIENE OF THE BARRACKS 65

cotton, cigarette-stumps, and other waste thrown into the bowl. The throwing of such articles into urine bowls should be punished, if detected, but detection is not usual.

It is neither desirable nor practical to have the men do their own laundry- work in barracks, but a couple of tubs, running water, and scrub-brushes should be pro- vided, if possible, to enable them to do a certain amount of emergency work and cleaning. >^

The company commander should familiarize himself with the system of plumbing in his barracks, with a view both to detecting leaks and other faults, and to taking action for the institution of improvements where indicated, and likewise to fit himself to distinguish between poor plumbing and inefficient care of good plumbing.

The water-supply of the barracks should, if possible, be of water fit for drinking without boiling or other special preparation. If this is not the case, the men should be warned and the proper drinking supply carefully defined and lo- '^^ ^

cated. The general supply should be abundant for all purposes, and should amount to one hundred gallons per man per day, though so much need not ordinarily be used, and the amount really used will depend on a number of varying factors, such as temperature and climate, the character of the work done by the men, the care used, economy exercised, and the condition of the plumbing.

Where tub-baths are used, the consumption will be greater than if showers are used. While care should be exercised to prevent wastP, it is usually false ecopomy to Jiiu^er any reasonable use of water,

66 THE RECRUIT AND HIS ENVIRONMENT

as in bathing, scrubbing, watering plants or grass, or laying dust.

The water should be piped to the kitchen, the bath- rooms, water-closets, urinals, wash-basins, furnace-room, and to such places in and about the building as may be necessary for police purposes or fire protection. All faucets, exposed pipes and fire-plugs, and other parts of the water-supply apparatus, should be frequently in- spected for leakage and as to their working condition.

Except in the ways indicated above, the water-sup- ply in barracks is not usually controlled by the com- pany commander.

Good plumbing presupposes good materials, and such are usually furnished. Iron pipe should conduct the -J. , water-supply, and all joints should be tight.

. Faucets are usually of brass, and with pro-

per usage rarely need repairs, except new washers. Lead pipe is objectionable as being liable to cause lead-poisoning. Some water after a time will cause the pipes to fill partially or entirely with a deposit of mineral salts, or a growth of low vegetable forms, with a consequent lessening of the size of the stream. Such conditions, as well as advanced erosion, may necessitate renewal of the pipe. Kitchen sinks and wash-bowls should have their outlet-pipes and traps exposed and open to inspection, not closed in to become musty hiding-places for roaches. Kitchen sinks are usually made of galvanized or enameled iron or zinc, wash- bowls of enameled iron or porcelain. In any event, the surface should be smooth and capable of complete cleaning.

All should be effectively trapped to prevent the re- gurgitation of air or gas from the drains. Sinks should

THE HYGIENE OF THE BARRACKS 67

preferably have grease-traps, which should be easy to open and clean.

All bath-tubs should be of enameled or porcelain- lined iron or of zinc, and closet and urinal bowls of enameled iron or porcelain. All should be thoroughly trapped, and ventilated on the ground side of the trap, by communicating with the ventilating pipe. No odor should come from them, and they should flush freely and effectively on all occasions. Whenever one of them is found at all out of order, flushing poorly or imper- fectly, or emptying slowly, it should be put out of use until the fault is corrected. Such trouble, more often than not, comes from the use of newspaper as toilet- paper, or the throwing of matches and other improper objects into the bowls. Any leaking from a closet, urinal, or drain should be immediately corrected, as especially apt to cause disease. The maintenance of thorough cleanliness in the closet is incidentally the most ready way of learning of such defects, while the faults arising from its neglect are at times unjustly at- tributed to the plumbing.

Of the various systems of lighting in use in our bar- racks, electricity is by far the best. Both oil and gas consume and contaminate the air, produce - . , ^ dirt and much heat, may be blown out, and give relatively poor light. Electric lighting produces no dirt, neither consumes the oxygen nor adds to the combustion products in the rooms, produces very little heat, cannot be blown out, and gives a brilliant, steady light that is very much better than either of the others. The danger of explosion is absent, and that from fires is reduced to a minimum by proper wiring. The lights should be suf&ciently numerous to illuminate well ail

68 THE RECRUIT AND HIS ENVIRONMENT

parts of the building, while in the reading and recrea- tion-rooms they should be numerous enough and placed low enough to make reading and writing practically as easy as in the daytime. A particularly satisfactory arrangement of electric lights is one whereby the source of light is hidden, the light being reflected up to and back from a white ceiling, giving an even, steady glow without glare. ^ Dull and flickering light, such as is often produced by gas or oil, is very trying to the eyes, and causes strain and fatigue ; while the vitiation of the air by the combustion of these substances neces- sitates much more liberal ventilation, or causes suffer- ing. Economy in lighting should be practiced by ex- tinguishing lights when the necessity for their use has passed, as in the dining-room and kitchen after they are cleaned, in the squad-room late in the evening, thus having more for use in recreation-rooms.

^ " The fonr types of lighting systems in common use to-day are : day- light, direct lighting systems, indirect lighting systems, and semidirect systems. The evenness of illumination and the proper diff useness of the light, with exclusion of all extremes of surface brightness, are ideal con- ditions best realized at present in the proper illumination of a room by daylight. As Ferree points out, before it reaches our windows or sky- lights, daylight has been rendered widely diffuse by innumerable re- flections ; and the windows and skylights themselves, acting as sources, have a broad area and low intrinsic brilliancy, all of which features contribute toward giving the ideal conditions of distribution stated above. The best distribution effects given by artificial lighting are obtained with the indirect systems in which the source is concealed from the eye and the light is thrown against the ceiling or some other diffusely reflecting surface. In the direct systems the tendency is to concentrate the light on the object viewed, and too often the eye is not properly shielded from the source of light. The semidirect systems represent a compromise in which a part of the light is transmitted directly to the eye through a translucent reflector, and a part reflected to the ceiling. Like most other compromises, this one is not ideal." — Journal of the American Medical Association.

THE HYGIENE OF THE BARRACKS 69

As stated earlier, the subjects of ventilation and heat- ing are so intimately connected that no consideration of the one is complete unless it includes _, the other. This is so for the reason that ^

gravity is the most important factor in ventilation, and the weight of a given volume of air is less or greater as it is warm or cold. In other words, we influence or con- trol gravity by means of artificial heat. The same force is the principal factor concerned in the diffusion of heat and heated air throughout barracks.

In summer, doors and windows can be kept open, and ventilation is seldom a very serious problem ; but in winter or very cold weather, when doors and windows are closed and all the outside air is so cold that its im- pact causes discomfort, the case is different.

Open fires are suitable for heating single, small rooms, but not large ones, though the presence of an open-air fire aids in the ventilation of the latter as well as adds its cheer.

Stoves give more heat and less ventilation, for the same amount of fuel used, than do open fires. They may be made to promote ventilation greatly by being surrounded by a sheet-iron cylinder or jacket, into which a fresh-air shaft empties at the bottom. The air is warmed as it enters, and rises into the room through the top of the cylinder, and later escapes by way of stove-door, window-cracks, and sundry other outlets, including outlet-shafts, if such are provided.

The inlet should be screened to keep out dust and dirt, and the top of the stove or of the cylinder should always be provided with an open vessel of water, to moisten the air by its evaporation.

Cast-iron stoves give off carbon monoxide, a poison-

70 THE RECRUIT AND HIS ENVIRONMENT

ous gas, when red-hot, and may so do harm. The air used in the combustion of fuel is taken from the room and passes up the chimney, fresh air replacing it from the outside, and quite satisfactory ventilation may at times be so maintained, even with unjacketed stoves, but it is not wise to rely on such means alone, especially in crowded barracks. Slow-burning stoves, such as an- thracite base-burners, exercise much less influence in this way than rapid-burning wood or soft-coal stoves.

Hot-air furnaces operate by heating fresh air, which is brought to them through a ventilating shaft from the outside, and which, when heated, rises through the tubes and passages to the registers, whence it passes into the rooms. One advantage of this method of heat- ing is that, with increased heat, in very cold weather it sends up an increased amount of fresh air. This air, though, is usually very dry if the water-pan of the furnace is not carefully watched and kept filled. This is due to the fact that air doubles its capacity for ab- sorbing moisture with each increase of 15° C. in its temperature ; so that outside air which at zero C. does not seem dry is excessively so when raised to 25° C. For this reason all systems of artificial heating should make some provision for moistening the heated air ; which otherwise causes discomfort and harm.

The method of heating just described is not very much used in our barracks, being regarded less favorably than the steam and hot-water systems.

Steam-heating is very satisfactory and is much used. In this system the heat from the fire is transmitted to water, which is made to boil, under pressure if neces- sary, and the heat is carried throughout the building by the steam, which travels through tight iron pipes

THE HYGIENE OF THE BARRACKS 71

that expand into radiators in the various rooms. It is a rapid method of heating, and one easily controlled by an intelligent man, and such a man should be detailed in charge of it. He should maintain an even, steady fire, enough steam to make the rooms comfortable, and keep the water in the boilers at a constant and proper level. Such plants usually show their maximum effi- ciency when a steam pressure of one or two pounds is maintained.

Water should be kept evaporating from the radi- ators, or, with a good man in charge of the system, steam may be allowed to escape from them to moisten the air.

Hot-water Keating is somewhat similar, but the pipes are filled with water instead of steam. It is a very steady method of heating, but slower in either heating or cool- ing than steam. High and low pressure systems are used, only the latter in our service.

The air heated by the radiators is dried thereby, and provision should be made for moistening it.

When steam and hot-water heating are used, they are made to promote ventilation by having the fresh air enter the rooms through or under the radiators. It is thereby warmed and made lighter, and at once rises, to be later distributed through the room by gravity, con- vection, and diffusion. In order that it may not again be drawn through the radiators and redistributed, a line of less resistance should be created for it by ventilating shafts opening near the floor and leading to the roof, or by an open fire-place to answer the same purpose.

As there is also danger of fire in and about barracks, and as that danger is increased in cold weather, all chimneys, flues, shafts, stoves, furnaces, etc., should be

72 THE RECRUIT AND HIS ENVIRONMENT

thoroughly inspected and put into first-class condition in the late summer or early fall, before fires are started. Competent men only should be detailed in charge of fires, fire-drill should be held sufficiently often to famil- iarize the men with their duties in case of conflagration, and fire-buckets filled with water should be distributed about the buildings. As a matter of cleanliness, and still more as a matter of hygiene, and especially in the trop- ics, this water should be renewed once or twice weekly, to prevent its serving as a breeding-place for mosqui- toes. Frequent inspections should verify the thorough- ness and effectiveness of this measure.

The avoidance of mosquitoes, flies, roaches, lice, and

other vermin has already been shown to be principally

. a matter of screening, cleanliness, and po-

lice ; but if an old barracks is infested with

bed-buffS or fleas, it is often a most difficult matter to

get rid of them.

The most effective way to do so is to give the build- ing and furniture a thorough overhauling, scalding out cracks and crannies of beds, floors, and walls, with boil- ing water, washing them with jive per cent carbolic solution, then closing all cracks with putty or strips of board, and painting over all. Infested clothing or bed- ding should be washed or steamed.

Frequent inspections should be made for the early detection of any recurrence or reintroduction of the pests, when their eradication from one room, or even from one bed, may suffice to end the trouble.

CHAPTER V

CAMPS

The soldier's time is partly spent in camps, and occa* sionally the periods so spent may extend to many months. The conditions of camp-life are in many respects radi- cally different from those in barracks ; the old sanitary problems may have to be met in very different ways, while new ones arise, and sickness once started has opportunities to spread that differ somewhat from those in barracks. Our own unfortunate experiences in the camps of concentration in 1898 clearly show that the assemblage of large bodies of raw troops into great camps is in itself a dangerous matter, and that, if wise care founded on knowledge is not used to prevent it, diseases in epidemic form may create greater havoc than the enemy in arms. On the other hand, the ex- cellent sanitary and health conditions maintained for long periods in the camps on the Mexican border, as well as in numerous other camps of the last few years, show clearly that the intelligent and earnest application of our present knowledge suffices to prevent such con- ditions in time of peace. Whether or not the knowledge we have can be effectively applied on the vast battle- fields of Europe is now in process of demonstration.

The medical department must and does take the in- itiative in sanitary matters, and it naturally finds much satisfaction in the excellent recent results, but it is only by having the interested and intelligent cooperation of the line that such results are attainable.

74 THE RECRUIT AND HIS ENVIRONMENT

At times the choice of the camp-site will devolve upon the company commander, at other times a site is assigned _ to him by higher authority, and he has no

choice in the matter. It is, however, usually within his power to improve a poor site, or to impair or destroy the value of a good one ; and whether he is more likely to do the one thing or the other depends largely upon his knowledge of military hygiene. The general principles regarding the selection, arrangement, and care of camps, as laid down in the Field Service Regulations, are to be observed, though they can at times be improved upon, and when such is the case it should be done. Let it be remembered that from a sanitary standpoint the important desiderata are: first, that the site should be clean and healthful ; second, that it should be kept clean and free from infection during its occupancy ; third, that it should be left so after the departure of the troops.

The consideration of the site of a camp must include an investigation of the healthfulness of the surrounding country, and in certain instances a very desirable site is wisely abandoned for one apparently less so, because the health conditions may be known to be better in the lat- ter. For example, in the Bitter Root valley in western Montana there occurs during the spring months a fatal fever, which is conveyed by the bites of infected ticks. These are found principally on the west bank of the stream, the eastern side being almost free from the disease. It would be wise, in that territory and at such a season, to forego considerable advantages that might be found on the western side, and to take the trouble of crossing the stream, rather than to rim the greater risk of infection with the " tick fever." A somewhat similar

CAMPS 75

disease occurs in certain river-bottoms in Japan, and in that case the camp could be safely placed on the infected side of the stream, above all levels sulked to fioodinrj^ as the infected insects are met with only at such levels. Oroya fever occurs only in certain narrow Andean valleys high above sea level. Kala-azar is found especially in old and infected coolie lines and houses, and in Africa sleeping sickness is transmitted by a fly that is found only in or about thick underbrush close to water, and relapsing fever by infected ticks that appear principally in regular rest-places or camps.

The qualities desirable in a camp-site vary somewhat with the season, breeze and shade, for instance, being desirable in summer and undesirable in winter. The site should have a natural slope, to insure the speedy disap- pearance of rain-water from tents and streets. The sur- face should be as regular and smooth as can be obtained, free from numerous rocks and hollows. Stumps and trees are at times objectionable, particularly if numerous and close set, but at other times they can be put to a surprising number of uses, and those that are most in the way will disappear in a short time after the camp is made. The inequalities of surface due to numerous large roots or lightly covered rocks are, however, harder to overcome.

The soil of the camp-site should be dry and firm, so as not to give rise to a great amount of dust in dry, or mud in wet, weather. Sandy or very soft loam is undesirable, and, in very windy seasons or neighbor- hoods, the dust it gives rise to may be a plague. A surface well set with grass is good, if not damp ; but the grass will soon die in tents and be tram}^>ed to pieces in the streets, and should be well cleaned up.

76 THE RECRUIT AND HIS ENVIRONMENT

The neighborhood of marshes or standing water should, if possible, be avoided, principally because they are apt to be infested with mosquitoes, but also because the ground may be wet. Ordinarily, high-ground water (shown by its nearness to the surface in wells or pits) makes for insalubrious conditions, much as do marshes.

Winds may be desirable or the reverse, according to circumstances. In regions where mosquitoes are abun- dant, a prevailing wind blowing them away from the camp is a great comfort, one in the opposite direction a great nuisance. However, certain observations in the Canal Zone have led excellent observers to believe that mosquitoes, especially certain species oi Anopheles, may and do fly considerable distances, even up to a mile or more, against the wind to get to towns and camps, ap- parently attracted by the odor.

In wintry weather a strong wind always produces discomfort, and in summer it may do so because of the dust and dirt it blows, and in such circumstances shelter from it should be sought.

As sites are unhealthful or infected, in most in- stances, either because of the presence of disease-carry- ing and infected insects, such as mosquitoes or ticks, or because of their previous infection from human oc- cupancy, old camps, marshy grounds, and places apt to present the conditions mentioned, should be avoided. While the avoidance of malarious swamps and of such disease-centres as have been mentioned above is of the greatest importance in regard to certain diseases, espe- cially those that are insect-borne, it is usually camp diarrhoea, dysentery, typhoid, and other infections dis- seminated largely by man himself that create the

CAMPS 77

greatest havoc in camps. The danger from these usu- ally increases with the length of time the camps are occupied, and with the increased opportunity for their defilement. This being so, bivouacs, temporary and per- manent camps are apt to be defiled in an increasingly dangerous degree in the order named. Even a dirty bivouac-ground may constitute a menace to the inhab- itants of the region, to other troops later following the same route, or to the command leaving it, on its return that way.

The danger of infectious diseases is lessened by at- tention to the following points : —

The ordinary shelter of the camp is furnished by tents, which may be of any of the varieties issued for the service, though the shelter-tent is only _ exceptionally used, in one camp, for more than a few days at a time. All tents are apt to be hot in summer and cold in winter, objections partly met by the proper use of tent-flies. All are liable to be crowded, and the air to contain many micro-organisms when they are kept closed. This can be met by thor- ough sunning and ventilation, with walls raised, for a part of each day when the weather permits, and by the frequent removal, cleaning, and airing of all blankets, clothing, and accoutrements to which the moulds and other organisms adhere, and the exclusion of articles in or on which they may grow, such as food, dirty straw, trampled grass, empty but unclean bottles, cans, and boxes. All tents are apt to be damp in rainy or wet weather, and to lessen this they should be well ditched, so that all water from the tent-walls and the surrounding ground is carried away and the tent-floor kept dry. If the camp is to be occupied for any con-

78 THE RECRUIT AND HIS ENVIRONMENT

siderable length of time, board floors should be fur- nished, or the interior be filled with fine gravel and rammed, while company streets should be raised and made hard and smooth by pounding or rolling; they can be much improved by sprinkling and treatment with crude oil, especially an oil that contains a large amount of asphalt base, as most California oil does. .If floors are used, they should be raised occasionally and the space beneath thoroughly cleaned and aired. The general tent ventilation is also important in promoting dryness. Because of the dampness, men should always try to sleep off of the ground. In permanent camps they may have cots. Straw sacks are helpful, but they also should be raised if practicable. Cots or beds may be improvised from timber, or easily from bamboo, in a country where that abounds. Small branches of pine or other evergreen boughs serve to make a well-ventilated and comfortable bed where they are found. Boughs, cornstalks, loose straw, moss or dry leaves may be avail- able in bivouacs. In other camps than bivouacs these materials should be stirred up and aired daily and renewed before they become mouldy or much broken up. Owing to the crowding in camps and the frequently poor bathing facilities, the opportunities for the spread of body- verm in are unusually good, and all precau- tions as to cleanliness, clothes-washing, and steriliza- tion, if necessary, should be exercised to prevent their introduction and dissemination. Dogs, cats, and other pets should be excluded from tents and usually from camps. Mosquitoes are to be avoided by means to be considered later, but if they are present, nets must be used. Flies, roaches, rats, and mice are best kept down by the maintenance of such good police that they

CAMPS 79

find no breeding-places, and no access to food in or about the tents ; hence the exclusion of food, boxes, cans, etc. In some places the camp is very apt to be full of fleas, and, as these insects do not stay long on their hosts and breed in the sand, floors, or bedding, cleanli- ness of tents, floors, and surroundings is most impor- tant, as the young live on decomposing animal and vegetable matters found there.

Because of ignorance, laziness, or viciousness, men at times urinate in or near tents instead of seeking urinals. The offense may not be readily detected, but it is none the less filthy and dangerous, and should be severely punished when detected.

Huts^ cabins, and dugouts may be used instead of tents in long-established camps, particularly in cold climates or seasons. Because they are not so accessible to light, ventilation, or cleaning as are tents, even closer and more frequent inspections and greater care in clean- ing are necessary, and particularly so in the prevention or elimination of vermin. At least once a week all clothing, bedding, accoutrements, and other accumula- tions of personal belongings should be moved outside and the places thoroughly inspected and cleaned. Such places as well as tents will require heating in cold weather, but as long as proper precautions are taken against fire and to provide for the escape of combustion products, this is desirable, as promoting dryness and ventilation, as well as comfort. Dryness of shelters and abundance of fresh air should be assured by all possible means, and to every man. All should work out-of-doors a part of each day. Wet clothes should be dried and dirty ones washed outside of the shelter, if it be at all practicable. Men with clothing or shoes wet from rain,

80 THE RECRUIT AND HIS ENVIRONMENT

snow, or slush should change them for dry at the first opportunity, and before lying down to rest or sleep. So far as military necessities permit, men, even those on guard, should be allowed to shelter themselves from inclemencies of the weather.

The water-supply to permanent or semi-permanent camps may be piped throughout them and delivered __ from stand-pipes conveniently placed. In

other instances, it will have to be hauled or carried from wells, cisterns, streams, and other sources of supply, to the place of consumption. If it is known to be good and free from infection, it may be drunk as delivered ; but when doubt exists as to its purity, and such will most often be the case, it must be boiled or filtered before use. Boiling destroys all disease-produc- ing organisms that are found in water, and renders it safe. Prolonged boiling makes assurance doubly sure, but if fuel or time is precious, making certain that the water comes to the boiling-point once may suffice, as that will destroy the organisms of typhoid, cholera, and dysentery. But it is at best a time-con- suming process, and if the water is not well cooled it is not so refreshing, and men seek it from other sources. Other methods of purification are therefore resorted to, and among these are filtration and treatment with chemicals. The Darnall filter, the efficacy of which de- pends largely on the precipitation of suspended matters before the filtration, and filters of the Berkefeld or Chamberland types, that are efficient by virtue of the fineness of their pores, are of great value, though the former type shows erratic action at times and the others are apt to be broken or get out of order on field service.

Chemical treatment of suspected or contaminated

CAMPS 81

waters is now used by many large cities, and gives very good results. In its simplest form, in a camp, it would ordinarily consist in adding one part of " chloride of lime " to about 600,000 parts of the water. For small quantities of water this may be measured as follows : Take a level teaspoonf ul of chloride of lime and dis- solve it in four pints of water. Of this add one tea- spoonful to a gallon of the water to be purified, or one tablespoonful to four gallons, or ten tablespoonf uls to a barrel of water, and allow it to stand for at least half an hour before use. The ordinary amount used by city water purification plants is one part to a million, or even less, but one part in half a million does not affect the taste or smell of water, is harmless, and is necessary in water containing much organic matter, so that the use of that strength or double it is advised for the field. ^

However purified, the drinking water should be kept pure and protected from all sorts of contamination until used. This is provided for in the directions accompany- ing the Darnall filter, but special arrangement has to be made in other cases. A simple and effective way of doing it is to have one drinking-place for each company, and to have at that place two or three barrels or large cans fitted with covers and with faucets near the bottoms. Water should be boiled, or otherwise purified, and run into one of these, covered, and allowed to cool. When cool it is marked as ready for use, and the water is drawn off through the faucet as needed. Meanwhile the next canful is cooling. When the first can is emptied, it is rinsed out with boiling water and refilled, to cool while

^ Should one have occasion to install a simple and cheap chlorine purification plant at a post, a good description of one may be found in U. S. Public Health Report, October 9, 1914.

82 THE RECRUIT AND HIS ENVIRONMENT

the second is in use, and so on. The barrels or cans should be elevated on a platform so that the faucet may be convenient, and a soakage-pit should be dug be- neath the drip and filled with small stones or gravel to prevent the formation of a mud-puddle. Waste of the water should be discouraged, but if it amounts to more than can be cared for by the pit, which should be about one foot deep by two to three feet square, outlets a foot wide and six inches deep, and of such length as necessary, may be made and filled with stones or gravel, to lead away the excess and permit of its absorption.

Outside contamination is prevented by the use of the tight-fitting cover. If faucets are not to be had, siphons may be improvised, if rubber-tubing is avail- able. Otherwise, the water will have to be dipped. If so, a clean dipper should be provided for the purpose, and the water emptied from it into the drinking ves- sels. No cup should be dipped in the water after it has been contaminated by hands or mouth. The dipper should be scalded from time to time, and should be kept clean in every way. If reliably clean ice is obtain- able, it may be added to the water. If its quality is doubtful, it may be packed around vessels of water, but should not be put into them. The general care of the water-supply as prescribed in Field Service Regula- tions should be observed.

There are no tests that can be quickly applied that will enable a medical officer to pronounce a given water-supply safe. He may form an opinion to that effect from a consideration of the source and surround- ings of the supply, but any idea that he can, by a simple and quick chemical test, or a microscopic ex- amination of it, gain positive knowledge that it is pure

CAMPS 83

and safe is fallacious, and should not be entertained. If the supply probably receives seepage from privies, stables, or homes, or washings from the same, or drain- age from near-by cities or towns, it must be regarded as unsafe ; and in other cases, where sources of con- tamination are not so evident, it is wisely precaution- ary to take the same view. In fixed camps there may be opportunities for the full and careful examination of water-supplies ; but even when such is the case, and the water is found satisfactory, the condition may change in a day because of some accident or the care- lessness of one or a few men. Boiled water should be used for many kitchen purposes, such as washing food-receptacles and such foods as are eaten raw. Boiled or actually boiling water should be furnished the men for washing their mess-kits. A good arrangement is to have for each company a box, a row of large kettles of hot water, at least one of them actually boiling, and a small mop or scrub-Jbrush. As a man finishes a meal, he takes his mess-pan and implements to the place where these are, scrapes any food-remnants into the box, rinses the articles clean in the first kettle, passes to the second and there scrubs them with the brush, and then scalds them in the boiling water of the third kettle. Proper provision should be made, by means of a trough-container or otherwise, to prevent soiling of the ground with bits of food or greasy water. The water-supply should be sufficient to provide baths for the men. If the camp be situated on a stream or other body of water, it may afford proper .

facilities in warm weather. Where such is °

not the case, and in cold weather, special provision will need to be made. Such provision will include a proper

84 THE RECRUIT AND HIS ENVIRONMENT

supply of water, sheltered and warm bathing-places, and a proper disposal of the dirty water.

The supply of water may be piped to the bathing- place, or it may have to be carried there. The former condition need not, ordinarily, concern the company officer, except that, if the water as delivered is very cold, most of his men will not bathe in it in cold weather. In case it has to be carried, each man should carry for his own use, and economy will then be exer- cised. The most effective use is then made of the water if the bather first scrubs himself from a basin, usiug soap and a rough cloth, and later rinses off the soap with a shower, which may be improvised by means of a large tin can and a piece of rope. Warm water should always be available, and may be kept so if a large can of water be kept over a fire near the bathing-place, and any man desiring to bathe be al- lowed to take from it, replacing an equal amount of cold water. A sheltered and warm bathing-place may consist of a room in a convenient building, of a special house, shed, or tent, heated, if necessary, by a stove, an extemporized brick oven, or other means. The floor should be hard and dry, or should be covered with wooden gratings to lift one above the waste water. If for lack of time or other reason a suitable bathing- place has not been prepared, and if it be cold weather, hot water may be furnished and men allowed to take baths in their tents. In such cases they should be careful not to spill water.

If bathing is possible only at the cost of considerable labor or inconvenience, a proportion of the men will neglect it, and it is therefore desirable that a proper place be provided and the men required to bathe at

CAMPS 85

least once a week ; while the feet, face, and hands should be bathed oftener, and facilities should be provided for that. These may be just outside or inside the tents. The disposal of waste water is at times as great a problem as the procuring of the fresh supply, and it will have to be solved in different ways under different circumstances. In large or permanent camps under- ground drains may lead it away ; at other times trenches may conduct it to a near-by stream or to dry wells or pits, and occasionally it may be necessary to collect it in barrels and haul it away. Always, care should be exercised that it does not flow or soak to the source of supply and contaminate that, and that it does not form breeding-places for mosquitoes. Where other provision is not made, fairly satisfactory results may usually be obtained as follows: A suitable space inside of a tent, say five or six feet square, is dug to a depth of four inches, and filled with gravel or fine stone, which is rammed. Over this a wooden grating is placed, and on the grating the men bathe. From the lower side of the space, trenches four inches deep and a foot wide are dug and filled with gravel or stones, and they conduct the water downhill to an open trench that leads it away, or to a soakage-pit about a yard square and deep, or larger if necessary, that is filled with large rocks, whence it soaks into the ground. Such pits, if in porous soil or gravel, will dispose of a great amount of water in a day. If in clay or close-grained soil, their working is not so satisfactory, and it may do better to run the water out in numerous, shallow surface-trenches from which it can evaporate. Similar precautions may be taken to provide for the waste water from drinking- troughs for animals.

86 THE RECRUIT AND HIS ENVIRONMENT

Facilities for washing clothing should be provided in each company, though they need not be more elabo- rate than a supply of good, and preferably warm, water, a board, and a scrubbing-brush and soap, The waste water may be disposed of as indicated for bath-water. If a boiler can be provided for clothes, it is desirable to have it. In rainy weather a heated tent should be furnished in which to dry them, but at most times they can dry in the open.

As in barracks, so in camp, the kitchen is one of the most important parts of the command, and on its proper administration depends much of the cheer- fulness, health, and efficiency of the men. The food should be abundant and good, and its prepa- ration such that the men will be nourished and satisfied by it, and not under the temptation to gorge themselves with pies, milk, and soft drinks of doubtful character from outside sources.

The mess in fixed camps may be made quite as good as in barracks, and, except in rare emergencies, the articles of the ration are both good and abundant. As the problem of cooking is presented somewhat dif- ferently in the field and in barracks, the company com- mander, the mess-sergeant, and the cooks should all study the best methods for field service. Some excellent gar- rison cooks are not nearly so good in the field, while others excel there. Economy, good management, and cleanliness are as important in the field as elsewhere, while, owing to the outdoor life and active exercise, the appetite is usually increased and more food required. Owing to the liability of chilling, exposure to wet, and the greater opportunities for intestinal infection, irritating, indigestible, and slightly nourishing foods,

CAMPS 87

such as green corn and boiled cabbage, should be used sparingly, while green or overripe fruits should be for- bidden. In the presence of epidemics of intestinal diseases, it makes for safety if only cooked food is eaten. Underdone cereals or vegetables are apt to cause indigestion, and as they are more difficult to cook thoroughly in the field because of the trouble with fires, wind, etc., particular attention should be paid to them. Rice, beans, hominy, oatmeal, and potatoes are probably most apt to be underdone. The methods of cooking in camp are various, the facilities ranging from the most simple and crude to the quite elaborate. Soup- carts, baking-ovens, and so-called fireless cookers may solve some of the problems; but the knowledge, in- dustry, and management of the company commander, mess-sergeant, and cooks must be relied on to solve most of them. They must utilize to the utmost the ar- ticles of the ration, and such other good food-supplies as they can obtain, and the equipment furnished for cooking and such additions to it as they have or can prepare ; and must put to use or minimize the harm of natural factors, such as wind, rain, snow, or poor fuel. It is the ability to do this last that enables some men who are not very good cooks in garrison to excel in the field. While a man knowing more of cookery may let a meal be spoiled or uncooked because of poor fuel, rain, and adverse winds, another man may have an excellent fire and a well-cooked meal in spite of all three. Camp craft results from experience and ingenuity, and the one should be furnished by manoeuvre-camps and prac- tice-marches, and the other encouraged by observant company commanders when it manifests itself. The man possessing these qualities will get the most from

88 THE RECRUIT AND HIS ENVIRONMENT

his utensils and his fire, whether he has a fully equipped camp-stove, a spider and pots, or merely a trench of his own digging.

As far as possible, men coming in from a march or a guard should be supplied with hot food at once, and when camp is changed an effort should be made to supply a hot meal as soon as the regular meal-time comes. This means the use of kitchen carts or fireless cookers, or the early establishment of the kitchen and the use of food that can be quickly cooked.

As in garrison so in camp, cleanliness of cooks, kitchen, and food are secondary only to the actual sup- ply of food, and the lack of it will do more harm than partial starvation. Flies have greater opportunities to breed in camps than in garrison, dust is more abun- dant and blows about more freely, fecal contamination of hands, shoes, and clothing occurs more readily, and the facilities for storing food so as to protect it from all these are poorer. Consequently, the amount of care to be exercised is greater, and the necessity for minute and thorough cleanliness more urgent. The hands, persons, and clothing of the cooks and assistants should receive the greatest care. Tables, benches, blocks, cooking utensils, and everything about the kitchen should be cleaned as soon as used, and scalded, if it be possible, with boiling water. Boxes and bags containing food should be frequently inspected inside and out, and their positions shifted, in order that insects may not gather in or about them. They should always be kept clean. Kitchen floors and surroundings should be raked, swept, or scrubbed after each meal, so that all particles of food and everything that might attract flies will be removed. Slop-buckets and garbage-cans should be washed after

CAMPS 89

each emptying, and not allowed to become crusted with a greasy coat of filth. At least once a day a rigid in- spection of the kitchen should be made and all points of kitchen police investigated. Reliable men should be put on this duty and rewarded for its proper perform- ance. Mosquito netting or wire-gauze covers should be provided for the protection of food while it is await- ing preparation or serving. Sheeting or boxes should protect it from dust.

It is questionable whether screening the entire kitchen is always advisable. Cleanliness is necessary in keeping down flies, and if a kitchen is screened all around it is darker and has more angles and comers in which dirt and scraps may collect to attract them. As the door is of necessity frequently opened, they enter and are then kept in by the screening. Screening is an aid in pre- serving the food uncontaminated, but it does not justify even the partial neglect of the more important matter of scrupulous cleanliness.

The kitchen fire should constitute a small crematory for kitchen-waste, and the cook should endeavor to be as independent as he can of civilian scavengers and fatigue parties. Nearly all scraps and solid waste that are to be thrown away can be burned by him, and at times he can take care of most or all of his dirty water by devices to be described later. Every tin can that is emptied should be thrown into the fire and all organic matter in or on it destroyed. Later it may be hauled away or buried.

The Arnold pit has been much used for some years and has often given great satisfaction. It is prepared as follows : A pit is dug about 60 inches long, 30 inches wide, 48 inches deep at one end, and 36 inches deep at

90 THE RECRUIT AND HIS ENVIRONMENT

the other. It is filled loosely with stones to a height a few inches above the general ground-level, and is banked on all sides to protect it from surface-water. The kitchen fire is built on these stones, and is inclosed on the sides, but the ends of the trough thus made are left open. All watery material, such as waste coffee and dish-water, is poured on the stones at the shallow end of the pit. The heat of the stones evaporates it. All solid waste, includ- ing tin cans, is burned in the fire. The ashes and debris are removed as often as it becomes necessary. This ar- rangement is improved by having the liquid waste first strained by passing it through a layer of straw or ex- celsior six inches deep, which would catch much of the fine solids and grease in it. The straw should then be burned and fresh supplied once or twice daily. It might be placed in the bottom of a large tin or other box, or in a shallow pit that drained into the larger one. At other times, when the particular conditions would war- rant it, the water could be led away to a stream by such a filled trench as was described for the bath-water, provided it were first strained through straw. Otherwise the trench would soon become foul with a deposit of soap, grease, and food-particles. When garbage and waste water are hauled away for disposal elsewhere, the matter of emptying them from cans and loading them into wagons should be carefully done under the super- vision of a responsible man, with a view to the preven- tion of spilling and the immediate cleaning up of any that may occur. Receptacles should be washed inside and out immediately after emptying, and should at all other times be kept tightly covered. Lime-washing the outsides of cans and the stands on which they rest renders the detection of dirt easier and is recommended.

CAMPS 91

If abundance of good food is provided in the messes, the men have no proper excuse for indulging in im- proper food obtained from peddlers, and such persons should be excluded from the camp and its environs.

Papers, sweepings, and other ordinary camp litter, as well as horse-manure and stable-dirt, should be burned, and such disposal of it is easy and conven- ient. If not so disposed of, it is apt to become ^

scattered, create a nuisance, and, particu- larly, to do harm as affording breeding- places for flies. A crematory may readily be impro- vised, and if a good draught is furnished, it may be kept burning continually with waste as fuel. Three forms of pit or crematory are as follows, and any one of them may be easily and quickly constructed : —

1. A circular pit with a cone of stones, around which the fire is built, piled up in the middle.

2. A horseshoe-shaped mound of earth, or a niche dug in a bank, or a trench open at one end.

3. A cylindrical crematory, which may vary in size according to the size of the command and the amount of material to be burned. It may be made of mud, stones, brick, corrugated iron roofing, old garbage cans, or whatever is available and suitable. In general, its height should equal or exceed its diameter ; it should have three or four openings, each eight to twelve inches square, placed at equal intervals around the bottom as air inlets. If iron bars are available they may be built into the cylinder to form a grate above the level of the air inlets. In rainy seasons a roof or other covering should be provided. The writer has seen excellent results from all the following types of cylindrical crematory : —

92 THE RECRUIT AND HIS ENVIRONMENT

(a) One built of mud plastered thick around a bar- rel. Inlets are provided and the fire lighted. As the barrel burns out the mud bakes. This size will suffice for a company.

(b) One made from three widths of corrugated iron roofing, each three or four feet long and each having a square measuring eight or ten inches cut from one corner of it. The three pieces are hooked together with wire in such a manner as to distribute openings left by the missing squares at equal intervals around the bot- tom of the cylinder. When set up this cylinder should be braced and steadied by piling mud or sod about it. It should suffice for two companies and has the ad- vantage of being transportable in very small space if the sheets are merely unhooked and laid flat one on another.

(c) Any size at all may be made from stone or bricks plastered with mud. One having the inside di- ameter of three or four feet at the top and a height of five feet or more should dispose of all the refuse of a regiment. One such in a camp of the 6th California Infantry in 1910 one day sei-ved to cremate a horse and another day a cow, in addition to the regimental refuse.

Like all other types of incinerator this requires mod- erately intelligent handling, as it is of course possible to smother almost any fire. The proper method, in case there is no grate to the incinerator, is to place large stones or, preferably, empty cans loosely in the bottom, so that air may pass among them freely. On these, or on the grate, place a little wood and the dryest refuse and light it. Then place some wetter refuse, then dry, and so on until the mass is well lighted. Continue to put on small amounts of refuse at a time, not filling the

CAMPS 93

cylinder but placing the material against the side toward which the wind is blowing. At evening the incinerator may be filled and allowed to smoulder all night. Next morning it should be started again with wood.

Other forms of incinerator may be improvised to suit conditions, and bits of stove-pipe or other means of im- proving the draft or protecting the fire from rain can be utilized. These pits must be cleaned as necessary, and the ashes and unconsumed matters, such as tia cans, placed where they cannot constitute a nuisance.

The proper disposal of the products of human waste, feces and urine, so that they may not create a nuisance or constitute a source of danger, is one of „

FCCGS

the most important problems of camp sani- _ ,_ .

tation. ihe methods available are incmer- ation, water carriage, various forms of carriage on land, and disposal in the soil. Considering these in turn it may be said of incineration that it possesses the advan- tage of safe and sanitary disposal with sterilization, it does not attract and breed flies and does not contami- nate the soil or the water supply. On the other hand, the first cost of the incinerator is large, the cost of up- keep and fuel excessive, carelessness in handling leads to the development of bad odors, and the equipment necessary constitutes such a mass of impedimenta as to make its removal ordinarily impracticable when the troops are moved. The method may therefore be con- sidered in most instances an unattainable ideal.

Water cai'riage is in some exceptional instances an excellent method of disposal. The conditions under which this is true, however, are relatively few. It may be applicable if the camp is known to be permanent or semipermanent in character and is situated on or close

94 THE RECRUIT AND HIS ENVIRONMENT

to tidal water or a stream not used for drinking pur- poses, that will remove the excreta promptly or at short intervals. It may also be used in camps of very tempo- rary character if they are so situated in regard to tidal or running water as to make its utilization for the pur- pose both simple and inexpensive, for instance, the building of seats out over the water. In the former case the installation may be anything from a complete sew- erage and water closet system to one as simple as in the latter case. Of intermediate arrangements a good one is the use of troughs of the Reed trough type, connected at their lower ends with drains of glazed tile that are laid with a good fall. The outlet of the trough may be closed by a hollow cylinder open at the level at which it is desired that the water should stand, say twelve inches from the bottom. Through this the accumulating fluid finds exit, and once a day or oftener the whole trough is flushed by simple removal of the cylinder.

Another plan, that has been found to afford a certain amount of satisfaction in a permanent camp emptying its waste into a small stream, includes large closed boxes or tanks made of concrete, though wood might be used, into and through which the sewage flows and in which enough sedimentation and disintegration oc- cur to make the outflow a pale, opalescent fluid almost free from odor and easily visible particles. It is not contended or thought that the sewage is thus purified, but the plan has two distinct advantages in that it al- most does away with bad odor, and it offers no encour- agement for the breeding of flies. Despite its advantages at times, water carriage of excreta is rarely applicable in camps, especially in campaign.

Disposal by what may be called " land carriage " in-

CAMPS 95

eludes those methods that necessitate carrying or haul- ing the excreta through or about the camp, among them the pail system, the dry earth closet, carts, and Reed troughs. They all have the common fault that, while they provide for the reception of the excreta as passed from the man, the matter of its ultimate dispo- sition remains to be solved, and a satisfactory solution is always dijB&cult and at times impossible. Among the expedients resorted to have been burial, burning, dump- ing at a distance from camp, dumping into water, and disposal in large pits. All are imperfect, laborious, ex- pensive, and unsatisfactory, they are apt to constitute nuisances, to attract and breed flies, to pollute water supplies, and in many instances to pollute the surface of the ground. Within the writer's experience one of the most satisfactory of these methods has been the dis- position of the contents of Reed troughs into large pits where the surface of the refuse was kept covered with a layer of crude petroleum. This resulted in absence of odor and of flies, but the labor involved in handling excreta from troughs was considerable, that in digging pits more, and accidents occasionally happened which resulted in pollution of the ground in camp. Such acci- dents are liable to occur with any system that requires the handling or carrying of dejecta through camp. In addition each method has inherent objectionable fea- tures. Pails and boxes require much labor to clean them and much supervision is necessary to see that the clean- ing is thorough and that covers are kept on in intervals of use, otherwise bad odors and flies abound. Dry earth closets are often not to be used properly because of lack of dry earth, the impracticability of separating feces and urine, the consequent mass of feces and mud to be

96 THE RECRUIT AND HIS ENVIRONMENT

handled, and the impossibility of keeping flies away from such a mixture. Like pails and boxes, earth closets are not easily moved with the troops. Latrine carts are highly expensive because of the transportation and labor they monopolize. Reed troughs also demand large expenditure in money, labor, and transportation, and in addition, if used with lime in accordance with the War Department order prescribing their use, they neither sufficiently repel flies nor do away with bad odor. It may be said though, that both of these objections may be met by the use of crude petroleum instead of lime. The objections set forth above will in most camps, es- pecially of mobile troops, be sufficient to prevent the use of any method of disposal calling for transportation of excreta by land, and it therefore happens that we still resort to those ancient methods that have at other times been so faulty that all of these we have been con- sidering were evolved as substitutes for or improve- ments upon them, namely, disposal on or in the soil.

Of these methods there are three principal ones : —

Disposal on the surface of the ground with little or no covering.

Shallow burial.

Deep burial.

The first named method usually merits only condem- nation, as leading to contamination of soil, persons, water and flies, though it occasionally happens that circumstances will justify it. In a certain camp near San Diego, for instance, "hardpan" as hard as most sandstones was found at or within a foot or two of the surface. The digging of deep trenches was impossible, as picks and crows were soon blunted and rendered useless, and when a trench was cu^ out to a depth of

CAMPS 9T

two and a half feet the soil was so non-absorbent that urine quickly filled it. In the neighborhood were some small areas where the overlying soil was deep enough to permit of plowing, and this had been done. A con- stant wind was blowing, and it was found that urine and strained kitchen water when thrown on this plowed ground to the leeward of camp was absorbed by the loose soil and held until wind and sun completed its speedy evaporation. Such a method of urine disposal is certainly not ordinarily desirable, but in the case in question it was the best and safest available method, and military hygiene must in practice consist largely of doing the best thing possible at the time and place.

The second method of soil disposal, burial in shallow trenches, seems to have had considerable use in the British and Indian services, but it should not be used in camps of more than a few (lays' duration, unless special circumstances make it appear the safest or only available plan. Its most obvious faults are that flies can breed in feces exposed to them and then buried to a depth of only six to ten inches, that a relatively large amount of ground is necessary, that soiling of the feet with fecal matter is rendered more probable, that soiled paper is apt to be blown about camp, that a relatively light rain, especially in the tropics, will flood such shal- low pits and diffuse their contents. When used the system calls for the constant presence of a sufficient guard to see that each man covers his own dejecta, that toilet paper is properly enclosed, weighted, or (after use) covered, and to attend to the final filling, packing, and turfing of each trench at the proper time. The use of crude petroleum in the trench and as a partial cov- ering for the fecal matter wqu14 lessen odor and flies.

98 THE RECRUIT AND HIS ENVIRONMENT

The de&p trench latrine is the form used in our camps of concentration in 1898, and it was condemned then and many times since as a contaminator of persons, soil, and water, a breeder of flies and of smells, and a constant source of supply where flies might and did load up with typhoid bacilli before visiting the kitchen and mess tents. All of this was true, but more recently, since the importance of preventing pollution of the sur- face of the ground and of preventing access of flies has been appreciated, and since actual and extensive prac- tice has demonstrated the feasibility and value of such precautions, it need be true no more. The danger to be feared from a proper use of deep trench latrines is pollution of the ground water, but as the introduction of a good supply of drinking water from outside the camp is nearly always resorted to anyhow, that is not a vital objection, and ease of construction and sim- plicity make it certain that this form of disposal will long be used. When used though, the trench should be properly constructed and cared for if the evils above enumerated are to be avoided. First of all it should be dug to a suitable depth, usually six feet or more, and protected from rain, washings, and caving. Then it should be covered with a box seat with hole covers that close automatically, and all cracks and crevices closed in such a manner that the pit is made quite dark and fly proof. Separate urinals of tin or tarred paper fun- nels opening into the pit by small angular tunnels should be placed at each end. They may be made im- passable to flies by stuffing them lightly, toward the bottom, with grass or straw, although painting them inside each day with crude petroleum suffices for this and keeps down odor.

CAMPS 99

Various improvisations of pit covers can be made that will require relatively little lumber, if tarred pa- per, burlap, or cheap muslin be substituted for it on the sides and ends of the box and for seat covers. By keeping in mind the requirements of making the pit dark and fly proof the resourceful officer can nearly always devise a satisfactory cover.

As to the subsequent care of the pits, it is thought that crude petroleum has advantages that put it in a class by itself as a pit dressing. It keeps down bad odors to a remarkable degree, is repellent to flies, does away with the use of earth or lime in pits, and indefi- nitely prolongs their usefulness in absorbent soils ; it is easily handled and transported, and is of great value for many other sanitary purposes about camp. It should be used to paint the insides of urinal funnels and to sprinkle over the surface of the pit contents each day.

Crude petroleum appears to owe its value as a pre- ventive of fly breeding mainly to the fact that it is repellent to adult flies. If maggots once hatch in a petroleum-treated pit they are apt to develop about as usual, despite the daily sprinkling with oil. Neverthe- less, the treatment is still worth while, as, if continued regularly, it keeps egg-laying adult flies away and limits the output of the pit to the one crop of flies. Without the treatment numerous crops would appear.

Other methods of caring for pits are also in use but are not so satisfactory. Earth and lime are sometimes used to cover each day's dejecta. They do not keep down odors or prevent fly breeding as well as the oil does, and they rapidly fill the pit and lessen its period of usefulness and necessitate extra labor to dig others. The burning out of pits has also been much used and

100 THE RECRUIT AND HIS ENVIRONMENT

has usually given satisfaction. The results are about the same as from the above described use of oil, and when that is the case it seems a waste of labor to over- turn each pit cover and replace it each day, not to men- tion the waste of fuel and the sometimes disagreeable features attending the burning.

The Jepson latrine and kitchen pits were among the earlier successful types of dark and fly proof pits, and excellent results have been reported from their use in proper soils. They differ from other pits in that they are dug with a post hole auger and are small in diam- eter, but deep. They are to be covered in and made fly proof.

Urinals should always be provided in camp, so that the men will neither need to urinate promiscuously through the camp nor to wet and soil the latrine seats. The day urinal may be a trough or a funnel of wood, tin plate, or tarred paper, that conducts the urine to a dark and preferably fly proof soakage pit. The funnel or trough should be painted with crude oil each day, if possible, and great care should be taken to insure a8 far as possible that the men do not urinate on the ground near the urinal and so make a muddy and foul place. In case oil is not available for troughs and fun- nels, fairly satisfactory urinals may be made by dig- ging pits and filling them with stones, or they may be filled with sawdust, or barrels or boxes with both ends knocked out may be half buried and similarly filled. Pine needles and sawdust are reputed to be especially valuable for filling because they minimize or prevent the odor of decomposed urine.

Night urinals consist of large cans or half barrels, to be placed in the company streets at night, and to be

CAMPS 101

carried away and emptied and washed in the morning. If one emptying does not suffice to prevent overflow or spilling, they should be emptied also at ten o'clock at night. They should be marked at night with lanterns, so that they may be located easily. During the day, when not in use, they should be kept clean and dry and exposed to the sun.

The general interest of officers in the prevention of disease and their knowledge of the subject has increased so much in recent years that they usually show them- selves efficient in maintaining good conditions. Never- theless, they as well as the medical officer would be greatly helped if each company had an enlisted man whose duty it was to study and look after sanitary con- ditions. Army experience had convinced the writer of this, and his experience on the Canal Zone, where non- medical men who were formerly carpenters, railroad men, engineers, foremen, soldiers, and so forth, have been trained by working experience to become sanitary inspectors and have rendered service of the highest value, has strengthened the conviction. Such a trained man in each company would be of the greatest value to the organization and to the surgeon. Having ac- quired his training and demonstrated his value he should have non-commissioned rank and pay.

Camp sanitary work may at times need to extend beyond the camp and may include the improvement or protection of a water supply, the search for and elim- ination of mosquito breeding in large areas, the drain- ing of swamps, petrolizing of pools, grading and ditch- ing of ground, the clearing of brush, and the regulation or control of traffic in food stuffs. Under certain condi- tions it may include a quarantine system, a war on rats.

102 THE RECRUIT AND HIS ENVIRONMENT

a house-to-house inspection of civilians, the control of epidemics, or the sanitation of entire towns or districts. In all of these cases trained men are of especial value to the sanitary officials as well as to the company, though their value to the latter is constant.

CHAPTER VI

THE HYGIENE OF MOVING TROOPS

The march, the battlefield, changes by ship and rail, all present their special problems of sanitation, neglect of which may result in disaster to the careless command or to its friends and allies. Many men and some offi- cers are apt to ignore the latter phase of the question and to think that when they have avoided harm to themselves and their companies they have performed their full duty in sanitary matters. Nowhere is a man his brother's keeper to a greater degree than in an army, and it is hoped that the fact may become more fully appreciated.

Article V of the Field Service Regulations deals well with the subject of marches ; but the rules there given should be applied with discretion. It must ^, be remembered that the various possible states of weather, roads, and personnel may result in an almost infinite variety of circumstances, all of which could not possibly be considered in any set of printed rules. Much must depend on the judgment of the commanding officer, in sanitary as in tactical matters, and his knowledge or lack of knowledge of sanitation may determine the success or failure of a movement. If good judgment is used in adapting the regulations to the circumstances, the rules laid down therein will constitute a reliable general guide. The length and speed of the march, for instance, must be materially influenced by climate, weather, roads, water,

104 THE RECRUIT AND HIS ENVIRONMENT

transportation, weight carried, amount and character of sickness in the command, the rations, character and state of the clothing, the spirits of the command, the objective, temperance in the use of intoxicants, and other factors.

The length and frequency of rests must be influenced by much the same factors, and the commander who sets a pace and determines the frequency and duration of rests without regard to these influences is not doing justice to his men. The time of day during which the march is to be made will also influence the length, speed, and rests, and the choice of it must in turn be influenced by diverse considerations. Thus the temper- ature may make daytime marching very trying, yet the state of the roads, the possibility of malarial or other infections, the presence of sick, and other consid- erations, may make it appear the lesser of evils. It is always well, therefoi'e, to consider these various influ- ences and to bear in mind that the command brought into camp in good spirits and good condition after what may be a relatively short march, is in better con- dition for large accomplishments on the morrow, than another command that has marched five miles farther, but has reached camp with the men footsore, weary, discouraged, and with their vital resistance so lowered as to be ready to yield to the inroads of any chance infection. The influence of climate and weather is so quickly manifested on the men, and in such obvious and well-known ways, as not to need much discussion, and a moderate amount of common sense and consider- ation for his men should cause an officer to make allow- ances for them. Heat, wind, snow, rain, fog, slush, glare, mugginess, all tire, discourage, and tend to

THE HYGIENE OF MOVING TROOPS 105

sicken the men, shorten the march, and increase the rests.

Closely related to these is the state of the roads. Mud, excessive dust, loose sand or gravel, very rough and uneven roads, all increase delay, vexation, and fatigue, and, even when weather conditions are good, may cut the march to a fraction of what is desired. Not to be separated from the question of roads is that of transportation. If the former are good, abundant wagon transportation may be used, if available, lessen- ing the loads of the men, supplying them with abundant food, tentage, and other necessities and comforts. If they are bad, transportation facilities may be much limited in consequence, or, if furnished, may prove a source of vexation and weariness, the men having to spend hours of toil extricating mired animals or wag- ons, in unloading, loading, and carrying freight. Such trials of body and spirit react on the health, and when, in addition, because of failure of the transport wagons, men have to lie down supperless and without proper shelter, the question of transportation has assumed a sanitary importance of magnitude.

Intimately related to the question of transportation is that of the weight carried by the men, and the at- tempt is wisely made to reduce this to a minimum ; yet under some conditions, and generally they are those in which men should have to carry the least, as in bad weather, over bad roads, on forced marches, after very trying campaigns that sicken man and beast, trans- portation may fail and the men have to carry extra ammunition, food, and clothing. If this is a necessity the best should be made of it and the load carried, but the march should, as far as possible, be regulated

106 THE RECRUIT AND HIS ENVIRONMENT

to suit the altered conditions. We are not able to breed or buy men as we do horses, with a view to their strength, speed, endurance, or spirit, though we do attempt to select them with a view to these qualities. Nevertheless, each organization will have its strong and its weak men, its fast and its slow, its cheerful and its despondent, and it is the less desirable of these that must be most considered under trying conditions. The weak man must not be overloaded, the lame man over- marched, because the more able men can march far- ther or carry more. Otherwise they will become sick, and the problem is worse complicated than before. Disregard of this simple fact has been known to re- sult in most serious consequences. Whatever the weight carried, it should be so disposed on the person as to carry as comfortably as possible, and not constrict or compress the chest. As stated before, it is on the free play and efficient working of the heart and lungs that strength and endurance depend. If the chest is compressed and its mobility lessened by tight clothing, crossed straps, or other cause, that free and efficient working are impossible, and the man becomes exhausted under a load that might not greatly inconvenience him if it were more wisely disposed. Experiments have de- monstrated that inhalations of oxygen enable athletes to run farther and faster, and with less inconvenience, than is the case without such inhalations. When the action of either the lungs or heart is interfered with, the oxygenation of the blood is hindered and early tiring, weakness, and exhaustion follow. These con- ditions constitute not only disturbing and delaying factors of a temporary nature, but also weaken the re- sistance to disease and prepare the way for infections.

THE HYGIENE OF MOVING TROOPS 107

Sickness in the command that is moving always occasions delay, often very much extra work, and, quite as often, danger of epidemics. All sick should there- fore be left behind, if possible, when the march begins; all hygienic measures should be employed to prevent other men becoming sick; all who do become so should report to the medical officer as soon as practicable so as to get the benefit of early observation, treatment, and care, and all who do not favorably and quickly re- spond to such early care should, if possible, be provided for on the way, in houses, camps, or hospitals, or sent back, and not allowed to hamper and constitute a dan- ger to the entire command. The Field Service Regu- lations prescribe that the sick shall be eliminated before the start is made, but in practice certain classes of sick are not always eliminated and later give much trouble. Among these are venereal cases. Many such do not appear on sick report unless frequent inspections are made and they are ordered to report. These men, though doing full garrison duty and feeling well, are likely to develop buboes on the march and be unfitted for either walking or horseback riding.

Men recently discharged from treatment in hospital for malaria, dysentery, and other debilitating diseases are apt to become exhausted or to have recurrences of their sickness when subjected to hard marches.

Weak hearts and weak feet are liable to break down under similar conditions, and men known to suffer from either should be excluded. Not only should sick men be excluded from the march, but well men should be taught and, if necessary, compelled, to conduct them- selves in such a way as to maintain their efficiency and strength. Alcoholism, particularly, should be discour-

108 THE RECRUIT AND HIS ENVIRONMENT

aged, and all straggling to get alcohol and all drinking in ranks should be punished ; for not only does the in- dulgence lead to inefficiency from drunkenness, but it predisposes to exhaustion, infections, injuries, to heat- stroke in hot weather and freezing in cold. While only harmful and not to be encouraged in camp, drinking, if not carried to excess and not prolonged into the hours belonging to sleep, is then less directly harmful than on the march.

Cheerfulness and bright hopes are powerful stimu- lants to accomplishment, and it should be the aim of the company commander to keep his men in such a state of mind. Difficulties may often be laughed away, while if given too much thought or gloomily dwelt upon they readily become insurmountable. One of the great items in Napoleon's success was his faculty of having his men accomplish the impossible.

Hardships may be magnified in retrospect; on the march they should be minimized and belittled, if un- avoidable.

Another occasional cause of exhaustion is said to be the reckless and excessive indulgence in water. The .^, Field Service Regulations state that under

"ordinary conditions a canteen of water should last a man a day." Ordinary conditions in the field are, however, hard to define, and the amount of water needed under varying conditions and by differ- ent men varies greatly. There is no doubt that many men do use water injudiciously, and that, by training or habit, they may teach themselves such moderation and restraint as to be enabled to make the contents of one canteen last them through any ordinary day's march. As the canteen holds two and one-half pints

THE HYGIENE OF MOVING TROOPS 109

and the march rarely covers more than eight or ten hours, it may be seen that this should not involve any hardship for a well and fit man. It is, however, a well- recognized fact that men who begin a march with the consumption of large amounts of water, and who early exhaust their canteens, are very apt to become ex- hausted or to fall out before the march is completed. The consumption of the water is not always the sole cause of such exhaustion, but both may be the effect of a common cause, such as sickness, diarrhoea, alcoholic indulgence, excessive smoking, or injudicious eating the night before. By the avoidance of such indiscretions the moderate use of water is made easy ; but if a man has spent a part of the night in alcoholic indulgence, smok- ing, and eating cheese and salt herring, his system is so loaded with poisonous waste-products that he needs a large amount of water to dilute and remove them, and depriving him of it will not improve his condition in any way. Aside from such indiscretions, more water is required by men whose food is very salty or very dry ; by those marching in a hot sun or losing much water in the form of perspiration, or those marching in dust, as at the rear of a column. Thus we see that while "ex- cessive " use of water is harmful, its liberal use is not. On the other hand, insufficiency of water is harmful, even when not causing suffering through thirst, in hot weather as predisposing to sunstroke, and as causing such concentration of the urine as to cause very severe bladder irritation, with burning and pain that occasion great suffering and alarm. It is nevertheless highly desirable that men should so conduct and so train themselves that they can be able to get through the marching hours without using more than one canteen-

110 THE RECRUIT AND HIS ENVIRONMENT

fill of water; and if for any reason they cannot do so, it is usually better that they should go thirsty than that they should drink water from unknown sources or of doubtful character, as a few hours of discomfort from thirst, or an attack of pain in the bladder, are to be preferred to an attack of typhoid, cholera, dysentery, or parasitic infestation. Sunstroke, however, may be as fatal as any of these, and if symptoms of it appear, water must be used, under the direction of the surgeon, if one be present.

The water problem should be handled as follows : — Before the march is begun, an abundant quantity of good water, boiled, filtered, or purified chemically, if necessary, should be supplied. If the water is boiled, that should have been done the night before, in order to have it cool in the morning. If other vessels are not available, it may be put in the canteens the night before and allowed to cool in them. Each man should drink what he wants before starting, using his cup for the purpose, and have his canteen filled from the good supply. Except rarely, he cannot know that the water he sees later in the day will be suitable for drinking, and he should therefore drink then only from his can- teen, and, in order that it may suffice, exercise great care and moderation in the use of that supply. As soon as camp is reached in the evening, the preparation of a fresh supply should be begun, and, if boiling is the form of purification used, the first drink furnished may be tea or coffee. Reckless or careless indulgence in water from supplies of unknown character may have the most disastrous results.

Field Service Regulations say that " sources of water supply are examined by experts and marked good or

THE HYGIENE OF MOVING TROOPS 111

had.''^ It is a difficult matter and a time-consuming proc- ess for an expert to determine whether or not a water supply is good or bad, and on the march a medical officer can only base his opinion on the source and sur- roundings of the supply as he can see them or learn of them from others. The appearance, odor, taste, and such other tests as he is able to apply under the circumstances can in no wise assure him that the water is fit to drink. It is therefore usually desirable that all water from sources not well known to be good should be purified by heat or otherwise before use for drinking.

Smoking is apt to increase thirst and should there- fore be discouraged on the march, particularly if the water supply be small in amount or of poor character. The use of chewing gum tends to lessen the urgency of the desire for smoking and also to lessen thirst, and may be regarded as helpful for those reasons. It is sometimes urged that cold weak tea or coffee be carried in the canteen and drunk on the march, in order to as- sure the use of boiled water. Aside from the possibility of their being diluted with unboiled water, and of tea being made with cold and unboiled water, these drinks are not so refreshing and thirst-satisfying between meals, to most Americans, as plain water, and it is not thought that they are as good for use on the march as the latter, provided that it is properly purified or sterilized.

The food-supply on the march, as elsewhere, is very important. Because of the greater amount of work per- formed, and the increased tissue-changes due to the outdoor life, the amount of food required on the march exceeds that required in garrison ; while because of the few and imperfect kitchen facilities, the new and strange environment, the absence of water-

112 THE RECRUIT AND HIS ENVIRONMENT

closets, and for other reasons, food infection is more apt to occur, and every effort should be made to obtain cleanliness and to serve all food sterile, rendered so by heat. Because of the exposure to which the men are subjected, diarrhoeal troubles are readily induced, and instating foods should be avoided. Except in rare instances it should be possible to furnish two hot and substantial meals a day to the marching column, and that should be done. A hot breakfast should be served before the march is begun, and it should be a substan- tial meal, such as one of meat, potatoes, bread, and coffee. Eggs and similar articles, if obtainable, may be used. The noon meal, also, should be prepared and issued to the men before starting, and should embrace much nutriment in relatively small bulk. Fried bacon, cheese, sliced meat, and bread meet the requirements well, while a pickle, a bit of fruit, or jam adds to the enjoyment of it. In the evening, after the hard work of the march is ended, the men should have another hot meal, and as they will have leisure to digest it, it should be more bulky than the other meals. Stews, if well made, answer admirably, and may be supplemented with such addi- tions as are obtainable. Because of lack of fuel, delay in the arrival of company wagons, the necessity of start- ing fires and doing the cooking after the halt is made, the evening meal is often late ; and if they can obtain other food many men eat it, often with little regard to its suitability. It is hoped that soup-carts, ambulance kitchens, and fireless cookers will correct this by having a ready cooked and hot meal prepared when the halt is made. Because of their portability, canned and pre- served foods are much used on marches, and the usual precautions are necessary to see that no spoiled cans are

THE HYGIENE OF MOVING TROOPS 113

used. If this be done, they constitute fairly pleasant and very wholesome food-supplies, but they should be sup- plemented with fresh articles when these are obtainable. The general care in the preparation of foods that has been indicated as desirable in camps should be exercised in the short camps made by marching troops.

The government provides suitable clothing for all varieties of climate and weather, and the company com- mander should see that his men are pro- niothinff vided with the proper kinds and amounts to meet the probable needs of the march. Flannel shirts should be worn even in tropical climates, as they pre- vent too rapid cooling of the body and afford protection from the night chill. Blouses or coats are rather an impediment than a help in the tropics, if flannel shirts are worn, though more useful and comfortable than a sweater in cold weather, especially cold, windy weather.

The poncho should always be carried and the blanket nearly always, even in hot seasons, as the night chill is often penetrating and is accentuated if the clothing or the ground be wet. The mosquito net, while not an article of clothing, may be mentioned here as most im- portant in tropical countries, or hot weather. It is the soldier's most important protection against yellow fever, malaria, and dengue; while it may be quite as efficient in protecting him from tick-bites, from the flies that infest with screw-worms, from poisonous insects and reptiles. Its use, though the importance of it has long been recognized, is apt to be neglected on marches.

It is not considered necessary to discuss in detail the various articles and kinds of clothing to be worn, but some few articles need discussion. The drill regulations allow the marching soldier three pairs of socks, one pair

114 THE RECRUIT AND HIS ENVIRONMENT

on liis feet, one in his blanket-roll, and one in his surplus kit on the company wagon. In order to keep his feet in good condition he should begin each day's march with clean feet in clean socks, and must always have a dry and clean pair of socks for emergencies, such as the accidental falling into mud-puddles or streams. It is therefore necessary that he should wash his feet and one pair of socks each night, and the company com- mander should make sure that he does so, and that, if possible, he then has facilities, such as a fire, for drying the socks. The socks should not only be clean and dry, but they should fit properly. If too long, they fold or wrinkle and make pi*essure or rub. If too short, they cramp the toes and may be as important in causing or aggravating corns, bunions, foot-cramp, and ingrowing toe-nails as poorly fitting shoes. They should be of such weight as is suited to the individual man, in general being rather light for foot-troops so as not to cause excessive sweating or burning of the feet. Any disorders arising from the use of improper socks or from other cause should at once be reported to the surgeon, who, by timely advice or treatment, may be able to avert lameness or disability.

Shoes likewise are frequent causes of lameness, and in many instances the company officer is to blame for not seeing that his men get proper sizes and fits. At other times the quartermaster's department is at fault in not having proper sizes for issue. In such event the man chooses a shoe of improper size, or buys them of improper shape and material from civilian dealers. The footgear of the army has improved in quality of late years, however, and most of the shoes now issued are excellent, both in shape and material. A proper shoe

THE HYGIENE OF MOVING TROOPS 115

should be sufficiently long and broad, so that the toes are not crowded even after a long march. It should not make painful pressure on any place, but should fit snugly and evenly over the instep and about the heel, to prevent rubbing or forward slipping of the foot. The heel should be broad and low. Two pairs of shoes are allowed, one pair on the feet and one pair in the surplus kit. If practicable, the day's march should always be begun in a clean and dry pair, and it is therefore im- portant that a part of each evening's work should be the cleaning, drying, and oiling of one pair. For the last-named purpose, a piece of fat meat will answer if other oil is not obtainable. Shoes left wet and dirty soon become hard, wrinkled, and uncomfortable, and " run over " and break more readily than those kept clean and supple.

Two suits of underclothing are allowed, one on the person and one in the surplus kit. As underclothing is even more important as a protection from dirt than from cold, these will also require frequent washing. Neglect of this may result in attacks of boils, ringworms, and other skin infections. When a day in camp permits it, and coffee tins or other receptacles are available for the purpose, underclothing should be boiled.

The towel,, but one being authorized, will require frequent washing.

For general purposes and use in all climates, the campaign hat is very satisfactory, though discomfort and complaint have been caused by the stiff brim that has been used for some time past. With a soft brim it is unexcelled for general use, though in the tropics a cork or pith helmet and in arctic weather a fur cap excel it for seasonal wear.

116 THE RECRUIT AND HIS ENVIRONMENT

There is no evidence of any advantage in red or orange hat linings.

The general rules for camp police should be applied to marches as far as practicable, and they can be ap- plied to a far greater extent than is ordi- narily the case. In order to do this, proper instructions should be given in advance, and each com- pany should have, as in camp, at least one man on sanitary police duty, whose business it would be to see to the proper disposal of waste matters, to prevent the careless and indiscriminate soiling of halting-places, to assist in preventing the use of improper water, and to do such other work of a similar character as the cir^ cumstances necessitate or the medical officer recom- mends. Men should not, except in urgent cases, be allowed to fall out except at regular halts. If the halt is a short one, the company commander indicates to the sanitary soldier a suitable spot for urine and feces. The man goes to that spot and marks it. All men needing to fall out go there and use the place indicated, after- ward covering their dejecta with earth. If the halt is longer, half an hour or more, the sanitary soldier re- pairs at once to the designated spot and digs a shallow trench for feces and a shallow pit for urine. All men should be instructed to use these places only, and the trench and pit should be filled in again before the march is resumed. In case a man, from urgent neces- sity, does fall out on the march, he should be instructed to cover his feces with earth, using his bayonet, if necessary, for the purpose. Similar rules should apply to men on outpost or picket duty, and in this way much may be done to prevent the surroundings of a camp from becoming an ill-smelling, fly-breeding nui-

THE HYGIENE OF MOVING TROOPS 117

sance. Scraps of food, greasy papers, and other articles thrown away by the men at the halting-place should be thrown into one pit and burned or buried.

On arrival at camp, the sanitary soldier should im- mediately begin shallow trenches in a proper place selected by the medical officer, and men should be punished for urinating or defecating elsewhere. After that, the other business of making camp may proceed. Without it, the camp should not be made, as its site will almost certainly be defiled.

In bivouac, or while actually marching, the men should take all possible precautions to protect them- selves from, or to rid themselves of, vermin and insects, and in warm weather the use of the mosquito net should not be neglected.

The hygiene of the battlefield has been largely set forth in the consideration of the camp and the march. All the general principles there set down battle, hold good and should be observed as far ^.i ^ as possible. Often, however, the military „ o->na necessities allow no time to be devoted to sanitary matters ; but even so, the soldier who has been well trained to a realization of the importance of such matters will be able to take better care of himself and to do less harm to his comrades than the man not so trained.

The man going into battle should, if possible, ob- serve all of the following rules in addition to the gen- eral care outlined above : —

1. Make sure that you have a first-aid packet, that it is in good condition, and that you know how to use it.

2. Have your cauteen full of boiled water.

118 THE RECRUIT AND HIS ENVIRONMENT

3. Be clean in person and clothing, be bathed, and have on fresh underclothing.

4. Have your bowels and bladder empty.

6. Eat only good, nourishing, and digestible food.

All of these rules have an important hygienic bear- ing in case he should be wounded. The introduction of the first-aid packet in its present form was one of the greatest improvements in military hygiene ever con- summated, and it has prevented an immense amount of suffering, mutilation, and death. For a large pro- portion of wounds, a properly applied first-aid dressing constitutes the most important part of the treatment, and, in many cases, the whole of it. W ith such a dress- ing at hand and a knowledge as to how to apply it, the use of water on wounds is very rarely necessary. But if water is used, it is most important that it should have been boiled. Otherwise it may infect the wound most seriously. Cleanliness of person and clothing are very important for the same reason, to prevent infections. Most infections of wounds are caused by bacteria de- rived from the skin or its coverings, and by simple cleanliness of these, surgeons are daily able to, and do, make extensive wounds that heal without a trace of infection. The importance of having the bowels and bladder empty, or relatively so, lies in the fact that wounds of these viscera are exceedingly dangerous, but that the danger is directly lessened with the chances of excremental soiling of the tissues. For this reason, eating, drinking, and moving, all of which increase or facilitate the escape of intestinal or bladder contents, are to be avoided in the case of belly wounds, and for the man so wounded we may formulate another rule :

6. If wounded in the belly, lie down in the most

THE HYGIENE OF MOVING TROOPS 119

comfortable position, eat nothing, drink little or no- thing, do not move, do not get excited or restless. If overlooked or forgotten, you may be better off than if foimd and transported.

The sanitary disadvantages under which men travel on our army transports are numerous, but they are mostly beyond the company officer's power to remedy. The transport regulations pro- . ^ vide for such sanitary measures and daily *^

inspections as would seem to assure good conditions, and the conditions are such that with the aid derived from sea air and changes of scene the health of the men is usually well preserved or improved. Over-crowd- ing is an evil frequently encountered on transports, and one from which others flow. The company com- mander is quite powerless to prevent this, but he should lessen the evils of it by having his quarters as freely ventilated as possible, having them policed each day, and vacated by both men and their belongings when opportunity offers. He should see that his men bathe frequently and have frequent changes of under- clothing, and that they get suitable opportunities for clothes- washing.

Transports are not infrequently infested with bed- bugs. The company officer can only partially correct this evil by the police and cleanliness of his quarters, and, at times, by bed-bug hunts and the use of insect- icides. In Canal Zone barracks, which are provided with bunks similar to those on transports, bugs are destroyed by boiling the canvas and its stretcher frame and flaming the upright supports with a gasoline torch.

The food on transports is usually of good quality and VQry nourishing, but the methods of cooking and

120 THE RECRUIT AND HIS ENVIRONMENT

serving it are almost always monotonous and unat- tractive, and result in unnecessary waste, improper methods of eating, and some disgust with the food. The company officer should try to influence these condi- tions for the better, so far as he can do so. Owing to the long confinement in exceedingly narrow limits dur- ing the trans-Pacific voyage, unremitting attention to all sanitary details is urgently demanded. All cases of sickness or disease of any kind should be reported to the surgeon early, in order that he may isolate conta- gious diseases, as well as give treatment. The two ills from which a majority of men suffer are sea-sickness and constipation, the former at the beginning of the voyage, the latter throughout it. The tendency to sea- sickness is lessened if the man goes aboard the boat in good general condition, with his bowels cleaned out and his system free from the poisons produced by over- eating, alcoholism, and other excesses. Constipation should be prevented, if possible, by the use of rather bulky foods, such as oatmeal, fruits, and vegetables, by daily exercise and a well-maintained habit of visiting the closet regularly and making the effort to defecate. Under varying conditions, troop trains may be com- posed of any kinds of cars that are in use. The gen-

eral principles of troop hygiene should be . *^ applied as far as practicable, whatever the

accommodations. The most common faults in troop trains in time of peace are poor policing and dirty cars, and an insufficiency of water for drinking and cleaning purposes. Both of these faults are usu- ally attributable to the railway officials, but the troops are partly to blame in that they are sometimes care- less and wasteful of the water, and make very little

THE HYGIENE OF MOVING TROOPS 121

effort to keep the cars clean. The company commander can therefore partially control the evils. He should also make it his particular care to see that the car closets are well supplied with water for flushing purposes, and that the supply is replenished as opportunity offers.

CHAPTER VII

THE HYGIENE OF HOT AND COLD CLIMATES

The general principles of hygiene are the same the world over and may be applied in any climate. They aim to keep the body strong, sound, free from infection, and at its maximum efficiency. Inasmuch, though, as the dangers of infection as well as of injury from extremes of temperature are somewhat different in the tropics and the arctics, it is well to give these conditions sepa- rate consideration.

Hot Countries The danger to life and health is greater in nearly all tropical countries than in those that are temper- ate. This is due to a number of causes, among which we may note the almost total neglect or ignorance of sanitation among tropical peoples, the high, even, and often moist, temperature in which disease-producing organisms flourish and multiply, the great abundance and variety of insect-life, the common pollution of water-supplies, the habits of dress, and the heat itself. It is sometimes said that the safest procedure in matters of hygiene in strange countries or climates is to con- form to the habits of the natives, but this is often a very serious error, and it has undoubtedly cost many lives. It is faulty habits in the natives that help to keep alive, in the tropics, many diseases that have long since almost or entirely disappeared from temperate climes, while the people sicken and die of preventable infec-

HYGIENE OF HOT AND COLD CLIMATES 123

tious diseases in far greater numbers than should be the case.

The native of the tropics is very apt to suffer from water-borne diseases, and cholera and dysentery, al- though not limited to tropical climates, are so much less prevalent elsewhere as to be relatively rare, even if not unknown. The native is in- fluenced in his choice of a water-supply by convenience, superstition, habit, and the fact that his ancestors did certain things, but not often by sanitary considerations. For this reason he suffers from the diseases mentioned, and partly for this reason he practically always harbors one or more varieties of intestinal worms. The only safe rule for general application to drinking-water in the tropics is that it should be sterilized by boiling, distillation, filtration, or chemical treatment. But this alone is not sufficient. The water must be kept sterile until consumed, by being put in sterile contain- ers and closed against all possible contaminations. Both Filipino and Chinese servants in the Philippines are so entirely ignorant of the very meaning of sanitary pre- cautions, that they are continually giiilty of such action as stoppering bottles of distilled water with corks they have held in their mouths, wiping out a drinking-glass with a dirty rag or paper picked from the floor, drink- ing direct from bottles, and bottling unboiled water rather than take the trouble of boiling it, and it is feared that not all soldiers are free from some of these faults.

It is generally asserted, and is theoretically true, that less food is required in the tropics than in colder climates, and that the fats and proteids i^i .« , particular should be considerably reduced. This may be admitted, but we must also admit that

124 THE RECRUIT AND HIS ENVIRONMENT

lifelong habits, exercise, and temperament exert an influence that cannot be ignored, and any arbitrary attempt to put American soldiers, especially if they be doing field-work, on a ration approaching the rice-and- fish diet on which many natives of the tropics live, will result not only in discontent, but also in impaired nutrition and in clandestine indulgence in food or drink of improper character. The present army ration is thought to be excellent for the tropics, as for home, provided that the men work and exercise as at home. If such is not the case, the ration is too heavy and should be reduced as indicated. The sugars and starches are well borne in the tropics, are not such " heating " food as fat and proteid, and do not tend, in the same way and same degree, to cast an excessive amount of work on the liver and kidneys. Neither do they offer opportunities for such harmful forms of intestinal putre- faction. Organic acids, such as fruit- juices, are espe- cially valuable and important, as well as agreeable, in the tropics.

Care must be exercised in the use of fresh fruits and green vegetables, not because they are in themselves harmful, but because they are apt to be contaminated, from unclean water or from fecal manuring, with the parasites causing intestinal diseases. The only safe plan in using them in countries where dysentery, chol- era, and intestinal worms abound is to have them sterilized : the green vegetables and some fruits by cooking ; bananas, mangoes, oranges, and similar thick- skinned fruits, by thorough washing in boiled water. A large part of the food consumed by white people in the tropics is preserved by refrigeration or by can- ning. It is as good there as elsewhere, but is apt to

HYGIENE OF HOT AND COLD CLIMATES 125

decompose rapidly after exposure to the ordinary tem- perature and atmospheric conditions, and should there- fore be used promptly after such exposure.

Owing to the facility with which potatoes and similar vegetables spoil, the tropical resident should early ac- custom himself to the use of rice, yams, and similar products. The use of condiments and spices is gener- ally more liberal in the tropics than elsewhere. This is, partly at least, a matter of custom, but it may have a physiological basis in that these articles are stimu- lant to the alimentary tract. They are not known to do harm.

Alcohol is quite as much abused by northern peoples in the tropics as in their own homes, or more so. In real moderation, that is, in the amounts that can be completely oxidized in the body •'^^conoi and used as food, it is not known tiiat alcohol is more harmful in the tropics than elsewhere. In greater amount it is so, for the reason that alcohol in excess is in all climates an irritant to the liver, and in the tropics the liver is already hard-worked, irritated, " sluggish," and subject to congestions, — conditions aggravated by the irritation from the alcohol. Like the proteins and fats it does less harm if plenty of exercise is taken to promote its oxidation and the elimination of the com- bustion-products. As in other climates, its use is only infrequently indicated, and abstinence from it is advis- able. Its very general, and often excessive, use among soldiers proceeds not so much from any needs of the system as from idleness, vacancy of mind, evil exam- ples or careless associations, laxity of public opinion on such matters, and absence of such restraining influ- ences as home-life and respectable female society. It

126 THE RECRUIT AND HIS ENVIRONMENT

would therefore seem that the company officer can best combat the evil by attention to these points. Heat- stroke and heat-exhaustion are much more apt to occur in a man who is drinking, and to be more severe when they do occur. All drinking to excess is debilitating and probably lessens the resistance to infections. Re- currences of malaria and dysentery are not infrequently brought on by drinking-bouts or sprees. Alcohol also predisposes in more indirect ways to disease-infections, as by rendering a man neglectful of the quality of his food or the use of his mosquito net, and because he may use impure water with his drink, erroneously trusting to the alcohol to sterilize it.

In general terms, the dress should be adapted to the climate and to insure comfort and protection. The clothing issued to the army fulfills these ° requirements, allowing variations in the underclothing to suit individual tastes and require- ments. The cotton service cloth for outer dress is cheap, strong, durable, fairly cool, and easily washed. The flannel shirt for the field and those of cotton for barracks meet the requirements. British writers lay some emphasis on the desijability of always wearing woolen clothing in order to protect from chill, and much has been said as to the value of the woolen belly-band or abdominal binder. The writer's personal experience, and observations as to the general American experience, in the tropics do not indicate that this is a rule of general application. As stated before, most tropical diseases are infectious in nature, and if proper precautions be taken to avoid the infections, it is not thought that the discomfort produced by too great warmth of body, excessive perspiration, and prickly

HYGIENE OF HOT AND COLD CLIMATES 127

heat is apt to offer additional protection. In the field, where the chill of night air is more keenly felt and where wetting may occur from rain or from fording streams, the flannel shirt should be worn, and it and the blanket meet the requirements. There is no objec- tion to the use of light flannels by men who find them comfortable, while in the cold season and in high lands, as at Baguio in Luzon, they may be much needed ; but for most of the service to which our men have been subjected in the tropics they are a source of harm rather than of good. Light-weight cotton undershirts, with short sleeves, and muslin drawers not coming much below the knees are preferred. The clothing worn in the tropics requires frequent washing and fre- quent changing, and a good-sized laundry bill is a necessity. The clothing is usually sun-dried, and that is an important aid in destroying germs on it. Most native wash-men do not boil it, but, if feasible, they should be required to do so.

The campaign hat, as previously stated, is an excel- lent article for field use, but it should be well ventilated by openings in the sides, and should be worn in such a manner as to preserve a large air-space above the head.

The service cap offers very little protection from either heat or light, and is an unsuitable form of headgear for the tropics. It should be superseded for garrison use there by the campaign hat or a helmet, the latter of pith or cork and with a ventilated sweatband and crown. Much has been said and written about the value of pro- tection from the actinic or invisible rays of the sun, and helmets with an interlining of metal foil, and hat lin- ings, underclothing, and spine-protectors of black, red, or orange material have been advocated as means of

128 THE RECRUIT AND HIS ENVIRONMENT

protection from them. Observation and experiment indicate that the main causes, other than infectious diseases, of tropical invalidism and discomfort are heat and humidity, and that, with due care in regard to these, the effects of actinic rays are practically negligible. In fact, it is the writer's opinion and observation that persons much in the sun are apt to fare better, except as regards infectious diseases, than those who remain much indoors, possibly because the former get more exercise.

The evil effects ascribed to the actinic rays are prin- cipally those manifesting themselves as functional nerv- ous disorders. Such disorders are notoriously hard to trace to a definite cause, and, on the other hand, the sufferers from them are the most favorable subjects for treatment by mental suggestion. Therefore, the fact that a number of such sufferers are benefited by the use of red underclothing is not conclusive evidence that their ills were caused by actinic rays.

Shoes should always be worn in the tropics as a pro- tection against infections. Comfort and fit should be considered as elsewhere, but because it is comfortable to go barefooted is not sufficient reason for doing it. One of the greatest causes of sickness and debility in the tropics is the hookworm, and as it usually gains entrance to the body through the skin of the feet, the general use of shoes is looked upon as an important method of protection against it. Plague infection usu- ally occurs through flea-bites on the feet and legs. Other infections occur in the same way ; and the subject will be discussed at greater length in another chapter. Shoes and leggings also protect against leeches, ticks, mosqui- toes, and other insects.

HYGIENE OF HOT AND COLD CLIMATES 129

Because of the heat, the relative cheapness of native

servants, and his comparative wealth, the American is

apt to nefflect outdoor exercise in the trop- _

• T. 11111 Exercise

les. It IS very important that he should not

do this, as abundant experience has shown that exercise lessens the liability to the nervous breakdowns that con- stitute one of the chief causes of invaliding from the tropics. It is desirable that the glare and heat of midday be avoided as times for such exercise, the early morning or the evening being preferred. The exercise should be incidental to interesting work or play. Tennis, polo, football, horseback-riding, and hunting are excellent forms. Marching is also good if the men are interested and cheerful. After the exercise, which should be suffi- ciently violent to produce a good sweat, the body should be bathed, well rubbed down, and dry clothing put on. Swimming is also a good form of exercise and one that should be encouraged, as every soldier should be a good swimmer.

With proper precautions as to exposure to the sun, the prevention of chill from wet clothing, and the avoidance of great fatigue, it is thought that exercise will do only good. Many white men in the tropics suffer from lack of it, very few, and they are usually persons already diseased, from excess. Its value lies in the pro- motion of the active functioning of the skin, liver, and other organs of waste elimination, and the resulting improved nervous control, rather than in increase of muscular strength. Without exercise, alcohol, tobacco, and excesses in food are all doubly harmful.

Because of the freer perspiration and the greater lia- bility to skin diseases in the tropics, more frequent baths and changes of clothing are necessary than in

130 THE RECRUIT AND HIS ENVIRONMENT

temperate regions. The bath water should not be suffi- ciently cold to produce shock or chill, but as such water cannot usually be obtained in the tropics, ° that feature need not require much con- sideration. Persons who have suffered from malaria or dysentery or other intestinal troubles should use tepid or warm water. It should be remembered that typhoid, dysentery, cholera, and certain infestations with animal parasites may be contracted by bathing in polluted streams or ponds, and such places should therefore be avoided. Whatever the source of the water, care should be taken that it does not get into the mouth and so carry infection. After the bath the body should be thoroughly dried, particular attention being paid to the arm-pits, crotch, and groins, and, if these parts sweat profusely, it is well to dabble them with some antisep- tic solution and then dry them again, after which they may be dusted with talcum powder. Fresh and dry underclothing must be then donned. If prickly-heat eruptions are present or appear easily, a weak formalin solution, about one teaspoonful of formalin to a pint or a quart of water, may be used to sponge the body after it is washed and before drying. It is thought that the measures here advised are as good as are known for the prevention of the prickly heat, small boils, chafing, and " dhobie itch " or ringworms that cause so much annoyance and irritation in the tropics. In addition, it should be remembered that some of these affections are contagious, and contact with persons having them should be avoided. Soldiers occasionally borrow articles of clothing from one another, and that is another method of spreading skin diseases. In Japan it is still a rather common custom for many people to bathe in

HYGIENE OF HOT AND COLD CLIMATES 131

the same tub or tankful of water, and that probably accounts for much of the abundant skin disease seen in that country. Such a practice, though economical of fuel and water, is to be avoided.

The heat, the bright light, the new and strange en- vironment, the native habits of both dress and conduct, unite to stimulate and excite the sexual de- ^ sires of the new-comer in the tropics, while his money and the native habits, poverty, ^° and views of morality, constitute a set of circumstances enabling him to gratify them. In consequence he is apt to indulge in such sexual excesses as impair his nervous control, unless, as is frequently the case, he is soon or often checked by venereal disease. Later, when he be- comes debilitated by his excesses or by other causes, his sexual vigor fails and he begins to worry about that, thus aggravating and accentuating his trouble. Nothing that is equally harmless so profoundly affects the mind of the average young man as the loss, even though it be temporary, of his sexual vigor, and nothing so prolongs and aggravates that loss as continual brood- ing over it ; so in this combination we have the making of neurasthenia and melancholia. Each man should know that his sexual needs are not greater in the tropics than elsewhere, that sexual or other excesses may bring about nervous exhaustion and temporary loss of sexual power, and that the best rules in the tropics, as elsewhere, are: 1. Sexual continence; 2. Avoidance of obscenity and indecency ; 3. Cleanliness of the genitals ; 4. Complete avoidance of thought or handling of them, except for legitimate and proper purposes.

The necessity for thorough policing and cleanliness

132 THE RECRUIT AND HIS ENVIRONMENT

of houses and grounds is even more important in the

tropics than elsewhere, because of the greater prev-

alence of vermin and of vermin -borne

diseases. Malaria, yellow fever, dengue,

.. plague, and other insect-borne diseases,

occur principally in the tropics, and are

best avoided by such methods of policing

as do away with the feeding or breeding places of the

insects carrying them. In addition, roaches and ants

abound in numbers and with a persistency not seen

elsewhere, and, as they run impartially in water-closets

and food-chests, it is easily conceivable that they may

transmit disease. Rate and mice constitute not only

an annoyance but also a great and positive source of

danger, because it is among them that epidemics of

plague begin, and it is from such rat epidemics that

those among people take their origin. Parasitic skin

affections prevail very widely among persons, domestic

animals, and fowls, and it is partly by cleanliness of

habitation that we escape them.

All the usual sanitary precautions as to cleanliness, plumbing, and good policing are to be observed in the tropics as elsewhere ; but additional care must be given to all standing water both inside the house and out, to prevent mosquitoes breeding in it. Such collections should not be allowed if they can be avoided. If allowed to exist, the water should be completely emptied and renewed once in four or five days at most, or should be kept covered with a film of mineral oil, which can be renewed at like intervals. Ponds or other large collec- tions should be stocked with fish, and the general pre- cautions against mosquitoes, to be outlined later, should be observed. Mosquito-proof houses have proved of

HYGIENE OF HOT AND COLD CLIMATES 133

great benefit in the prevention of mosquito-bome dis- eases in the Canal Zone, as well as adding very greatly to the comfort of life there. That they are not univer- sally used in malarious countries is a misfortune where it is not a reproach.

Very Cold Climates

The principal sanitary dangers menacing the dwellers in very cold climates, aside from lack of food and other things outside of our present consideration, arise from exposure to cold, resulting in frost-bite or freezing, from poor ventilation, from too intimate association with diseased persons or animals, from improper food or lack of fresh food. Infectious diseases are less numerous than elsewhere, as their germs do not find such favor- able surroundings in which to grow, and there are fewer persons to harbor and distribute them.

The outdoor air of arctic regions is purer and freer from disease-producing organisms than that of other regions. Man-polluted air is as dangerous there, however, as elsewhere. As ventilation and heating are, from a sanitary standpoint, insepara- ble, and, as free ventilation makes heating more diffi- cult because of the greater volume of air that must be warmed, it may be understood at once that the natural tendency in an arctic climate is to have poor ventilation. Every increase in ventilation lets in cold and allows heat to escape, and the discomfort of this is more acutely and keenly felt than that due to foul air ; so the effort to keep warm may cause the air to become vile. As animal heat helps materially to warm a crowded space, and as crowding lessens the consumption of fuel, man and dogs, sick and well, are thrown into close con-

134 THE RECRUIT AND HIS ENVIRONMENT

tact. If one man in a crowded, ill- ventilated room has tuberculosis, diphtheria, tonsillitis, measles, smallpox, or other contagious malady, the contagium or poison is so concentrated as to make all present unusually liable to contract the disease.

Ventilation, therefore, should be as free as possible, care being taken to warm the incoming air, as by al- lowing the air to enter through a tube or tunnel open- ing under or about the stove. Should the air enter unwarmed it will cause such condensation of moisture as to make the hut damp. Crowding should be avoided, and as much time as possible be spent in the open. Particularly should intimate association in crowded rooms with sick persons be avoided. The intimate con- tact with sick and with animals is also productive of disease in other ways than that indicated above. A man having gonorrhcea or syphilis is in such circum- stances much more apt to infect innocently and un- knowingly those about him than he would be under other conditions. Echinococcus disease, due to infesta- tion with a certain dog tapeworm, is almost limited to persons brought into such intimate contact with dogs as is here mentioned. Cleanliness is almost impossible under such conditions, and wounds are thereby very apt to become infected.

A pure water-supply is not such a rarity in the arctics as in the tropics, both because pathogenic germs do not

^ _.,_,, flourish in arctic temperatures and because

vvater ■, c u

men are less numerous as sources oi pollu- tion. The danger of pollution of a supply is greatest in the spring and summer, when melting snow may wash into it the excrement that was scattered in the neigh- borhood during the very cold weather. Excrement is

HYGIENE OF HOT AND COLD CLIMATES 135

apt to be so scattered, for the reasons that other disposal may be more troublesome and that snow and freezing prevent its constituting a nuisance to the nose and eyes. Especial care should be exercised to prevent anything of the kind, and drinking water should always be taken from points above any possibility of such contamination. Attempts should not be made, particularly on marches, to quench thirst with snow or ice, as they detract from the local and general heat of the body, and are liable to iri'itate the mouth and throat. Snow and ice may fur- nish the water-supply, but they must be melted and the water heated, when it may be profitably used in making tea, which is then refreshing, comforting, and stimulat- ing, and adds to the warmth of the body.

The food -supply of the arctics consists largely of canned goods, and may be quite generous. Every effort should be made to supplement that diet with fresh articles, whether of animal or vegetable origin, as scurvy is otherwise apt to make its appearance. This disease is due to the deficiency of some principle or " vitamine " contained in both meats and vegetables, which is destroyed by overheating, by long storage or by ripening and drying of the vegeta- bles. For instance, it can be caused in guinea pigs by a diet of bread and dried mongo beans, while a diet of bread and sprouted mongo beans protects them from it. The Scott Antarctic expedition avoided scurvy by the abundant use of the fresh or frozen meat of gulls, pen- guins, and seals, and the surgeon especially praises seal meat as an antiscorbutic.

Because of the necessity of greater bodily heat-pro- duction in the arctics, more food is required, and, as meat and fat give rise to more heat during their oxi-

136 THE RECRUIT AND HIS ENVIRONMENT

dation, and as they are also more readily obtained, it is in them that the increase should be made. This need is recognized by the government, and is met by an increase in the ration for troops serving in Alaska. Where game or fish are obtainable they should be used to supplement the ration. The methods of preparing the food are not essentially different from those used elsewhere. Foods should be served hot, and the heat of the body so conserved.

Alcohol should not be used in the arctics except as a drug, as it increases heat-radiation and loss. Particular care should be takeu that it is not used during the period of exposure to cold, as that is the time when loss of heat is to be especially avoided. If used at all, it should be after the period of exposure, when the body is chilled and the surround- ings warm and comfortable. In such circumstances it may be of considerable value, but its routine use should not be practiced.

Fur, feathers, and wool as conservators of heat, and canvas and leather as protection from wind, constitute the main clothing-supply and bodily pro- ° tection in the arctics. Fur, leather, and canvas, with the exception of shoes, are for use out-of- doors only, wool for general wear both indoors and out, while feathers or down are used in bedding. Extreme cold is nearly always dry, and may therefore cause less suffering than higher temperatures when the air is moist. Wind of course greatly increases the suffering and the danger from either dry or wet cold. The reason that fur, feathers, and wool make such warm clothing is twofohl ; they are themselves poor conductors of heat, and they contain in their interstices a large amount of

HYGIENE OF HOT AND COLD CLIMATES 137

air, another poor conductor. For the latter reason a multiplicity of light garments is warmer than the same amount of material woven into one heavy garment, and cotton or silk wadding may be used also with good re- sults. It is because they prevent the displacement of the warmed non-conducting layer of air within the clothing that leather or close-woven canvas affords such excellent protection against wind.

Fur caps and gloves, blanket-lined canvas boots, can- vas overcoats lined with blanket or sheepskin, woolen outer and under clothing, woolen socks, oiled shoes, felt overshoes, and canvas leggings are issued for very cold service, and in a few far northern posts buffalo coats are furnished for use by men on guard. By proper use, these articles can be made to furnish adequate protection against any cold that is likely to be encountered. The parts most apt to suffer from cold are those most ex- posed and having the weakest circulation, such as the nose and cheeks, the ears, hands, and feet. The fur cap protects the head and ears, but not the neck and face. It should therefore be used with the overcoat collar turned up, or with the hood of the coat, in very cold weather. The blanket-lined canvas hood covers the neck and part of the face and therefore affords better pro- tection. A veil or a strip of cloth may also be worn across the lower part of the face if necessary. The fur gloves adequately protect the hands except in the most extreme cold or in cases of long exposure. If necessary, woolen gloves may be worn beneath them. When, in spite of them, the hands become numb and cold, they should be beaten or exercised to warm them. For work not requiring the use of individual fingers, woolen mit- tens under canvas afford good protection for the hands.

138 THE RECRUIT AND HIS ENVIRONMENT

Care should be exercised about removing the warm hand from its glove to do delicate work in the cold. A soldier has been known to have both hands frost-bitten because he removed his gloves in the wind and in a tem- perature of 40° below zero F. long enough to adjust his saddle. The feet are easily kept warm during walking if the government issues of footwear are properly used ; but when men are riding and not using the feet, or when snowshoeing and the feet are bound so tightly that the circulation is interfered with, the problem is more diffi- cult. Except in wet weather, the foot-covering should not be impermeable, as the feet when comfortably warm are apt to perspire, and such a covering as a rubber shoe causes the perspiration to condense against it and to be frozen there, so that the foot is almost or actually in contact with ice. An oiled shoe is less ob- jectionable, as it does permit the vapor to escape, in part at least. In very dry cold, however, a felt shoe, or two or more pairs of woolen socks with canvas or soft leather moccasins, may be better still. Fur-lined boots or stockings are very warm. Surgeon Atkinson, of the Scott expedition, says : " It was essential each night on camping to change the footgear immediately, the socks having become saturated with perspiration. Special socks of very thick woolen texture were kept for sleep- ing in, and they remained practically dry. Over them was worn a loose fitting bag of some fur. On changing the socks they were pinned together with a safety pin and hung outside. If there was a good sun, by next morning they were completely dry and comfortable." The remainder of this chapter is made up of extracts from Surjjeon Atkinson's account of the antarctic ex* periences of the Soott expedition.

HYGIENE OF HOT AND COLD CLIMATES 139

" Frost-bite varied in degree from the loss of a super- ficial patch of skin to the loss of parts of _ ^ limbs.'' ^'°«*"

" Frost-hites of First Degree. — In the open, it was quite a common and even laughable ex- perience to see one's companion's nose or cheek with a patch of white upon it. He, at the time, was quite un- conscious that anything was wrong. When warned, he removed the warm can from his mit and placed it upon the offending part. At the same time, if there was any wind, he would turn away from it. After a minute or so, with a slight tingling sensation, the circulation re- turned to the part, and in the course of a day or so there was a very small loss of quite superficial skin. Parts which had been attacked by frost-bite became necessa- rily more subject and also, luckily, gave warning. If a wind sprang up, one felt a sting like that of a bee, and knew immediately that the nose or cheek was attacked, and took measures to bring the circulation back."

" Frost-bites of Second Degree. — Frost-bite of the second degree caused blisters, varjdng depths of sub- stance being implicated. It was quite common after any cold sledging trip for one's fingers to be bulbous at the end. This was due to blisters of varying sizes, and was caused by exposure to cold, and also by handling cold metal objects, like the cooker and Primus. These blis- ters were of no importance, and on return they were pricked ; after some time the skin was replaced and the fingers became normal again. . . . Another effect of continually touching cold metal objects was that the fingers never quite reached the stage of blistering, but the skin became hard and thickened, so much so that one was unable to appreciate such an object as a match

140 THE RECRUIT AND HIS ENVIRONMENT

between the fingers. The hardened skin always peeled off after we had been back in the hut for a time."

" Frost-bites of Third Degree. — This degree, be- sides causing blisters, caused actual loss of substance by gangrene. After exposure the onset of gangrene came on at a varying period. It was never immediate, and varied from a fortnight to three weeks. The blister contained an evil-smelling, sanguineous fluid, and be- neath it was a dark, f ungating patch. A line of de- marcation formed after a varying period, and then sloughing of the affected part followed. . . . The only treatment that the majority of frost-bites needed was the application of a warm hand to the affected part. The application of snow is probably of use in temperate climates, but where the snow is at the same temperature as the air it is impossible to do this. Also, the snow in the Antarctic is composed of hard, sugary grains, and the effect of rubbing this upon the affected parts would probably be more serious than the frost-bite itself. It was always as well to be certain that one had no frost- bites before returning to the warm hut."

" The effect of food upon the circulation was very well marked. After one had been under way pulling a sledge for four or five hours, if there was any wind, one started feeling cold, and then began to be frost- bitten. On camping and having something hot to drink the effect was immediate. One felt the heart begin to beat strongly and powerfully, and gradually a glow spread downward into one's feet and generally over one's body. On cold days, when the temperature was below -40° F., if the air were still one was not at all subject to frost-bite, but immediately a slight or strong breeze sprang up with a rise of temperature one's face

HYGIENE OF HOT AND OOLD CLIMATES 141

became affected. The amount of evaporation on a windy day compared with that of a still day is about the pro- portion of five to one. After washing and removing fatty substances from the face one was more susceptible to frost-bite."

" Effect of Concentrated Food after Man-hauling for more than Two Months. — All parties noticed after being out for more than two months man-hauling that they got practically no satisfaction from the concen- trated food. One became exactly like a machine. With a certain quality of food it was possible to go on for a certain time and do a certain amount of work. With a little extra food a little more work could be done. With the ration that was provided, after a time one started feeding on one's tissues. Emaciation was extreme on the return from the Southern journey, and the effects of cold were naturally much more severe in this state. Owing to the fatty nature of the food defecation was extremely easy, and one reacted in this way immedi- ately to any increase of food."

" The monotony of travelling over a dead white sur- face on overcast days, when no horizon was visible, was extremely marked. It can only be likened to intellectual starvation.

" The effect of a cold trip upon the constitution was extremely well marked, though with nothing definite. In any trip extending up to a week, where the tempera- ture was continuously below -40° F., the men returned in an extremely low state. During this time one never, while in the sleeping bag, got any conscious sleep, and once or twice there were well marked cases of men sleeping while actually under way. This want of sleep caused a general lowering of the constitution, and the

142 THE RECRUIT AND HIS ENVIRONMENT

lassitude after a cold sledging journey is a thing always to be remembered."

" Snow-hlindness on Bright Days. — If one did not wear glasses, even for so short a time as half an hour, on those bright days, one was practically ' certain to have an attack of snow-blind- ness. The eye felt perfectly well while at work in the open, but the initial symptom was always noticed upon entering a tent where a Primus stove was alight. The attack began with a feeling of grains of sand in the eye. There was marked spasm, conjunctiv- itis, and weeping. Photophobia was well marked. This lasted for a varying period, the eye being irritable for as long as two days, even with treatment. The conjunc- tiva was congested and swollen, and the condition one of extreme discomfort. It was a pure conjunctivitis and due entirely to the sti'ength of the illumination. . . . When away sledging the tea leaves used to be saved after luncheon and, made into a rough poultice, were worn over the affected eye under the snow goggles. This always produced a greater degree of comfort and was beneficial."

" Snow-hlindness on Overcast Days with Strong and Diffused Light. — On these days there was want of contrast, and the diffusion of light was caused by re- fraction and reflection of light from the surfaces of minute ice crystals, which were continuously falling. The light therefore came from all directions equally. It was impossible to distinguish the difference between foreground and horizon. One's appreciation of where- abouts was practically limited to the skis on one's feet. Contrast was entirely absent because of want of shadow, and, as an instance, it was possible to be standing within

HYGIENE OF HOT AND COLD CLIMATES 143

arm's length of a snow cairn 9 feet high, and for the cairn to be invisible. Eye-strain was continuous, the eye striving to make out whether the foot was being placed on an even surface. It was impossible to appreciate any inequalities, such as sastrugi. At the same time the illu- mination was intense. The result of these two conditions was to cause conjunctivitis plus diplopia from the tir- ing of the eye muscles. The diplopia was exceedingly marked, and lasted for some considerable time. It was impossible to accommodate for any object, and it was only on going into the tent or seeking any dark object near that the diplopia was realized."

" Snow-blindness on Dull, Overcast Days. — On such days the effect was entirely one of eye-strain. Although the eyeball was congested to a varying degree, the main effect was due to eye-strain, and diplopia was much more marked. The want of contrast was the same, but the intensity of illumination was absent.

" The deductions from the above are that snow-blind- ness is in part eye-strain, and in part due to the actual effect of light."

For the prevention of snow-blindness, leather goggles with amber glasses are recommended. Care must be taken that no metal comes in contact with the skin, that the glass is well away from the eye, and that the entrance of light from the sides is excluded. Eskimo " snow-eyes," or wooden spectacles with slit-like openings for vision, are said to be excellent. The use of veiling across the eyes, and the practice of marching with the eyes fixed on the back of the man ahead, the leader being changed at short intervals, are at times helpf uL

PART II

THE CAUSES OF DISEASE

•' He discovereth deep things out of darknejs, and bringeth otU to light the shadow of death."

Job 12 : 22.

CHAPTER VIII

THE REMOTE OR PREDISPOSING CAUSES OP DISEASE

For our purposes it may be assumed that most of the diseases with which we are concerned are due to animal or vegetable parasites ; but not every man exposed to infection by such parasites contracts the diseases caused by them. A special predisposition or liability is neces- sary, otherwise everybody would have tuberculosis, the entire army at Chickamauga in 1898 would have had typhoid fever, and all physicians would die of infectious diseases within a short time after entering upon their profession. This matter of liability or immunity to diseases is one of the most interesting, complicated, and important in the whole realm of medicine, and many of the world's greatest thinkers and investi- gators find it worthy of their highest efforts and con- stant attention. It is the purpose of this chapter to deal with these questions in some elementary aspects that should be known by the company officer, in a practical and simple way, without technicalities.

One of the most important of the factors concerned in predisposition to disease is heredity. Every man inherits from his ancestry something that renders him liable to tuberculosis, but im- ■*

mune to rinderpest and chicken-cholera. He possesses in a degree not possessed by any other known creature a liability to malaria, syphilis, gonorrhoea, yellow fever, cholera, smallpox, and other diseases, while he shares with many other animals his susceptibility to tubercu- losis, suppuration, plague, and anthrax, and at the same

148 THE CAUSES OF DISEASE

time he is not at all subject to some diseases that are very fatal to his domestic animals.

In addition to its influence in this general sense, he- redity has long been credited with great influence in predisposing certain families or individuals to certain diseases. Consumption was long looked upon as a hered- itary disease, but, with our more complete knowledge as to its nature, the tendency is now to regard its ap- pearance and persistence in families as an evidence of familial contagion rather than of heredity. In the case of cancer, another disease prone to " run in families," the same explanation is now frequently advanced, though no germ-cause is known for the disease. The influence of heredity, though still considered weighty, is not now so much emphasized as formerly as a cause of insanity. In all these diseases, however, it is still contended that a predisposition, a type of tissues endowed with resisting powers below the normal, is in- herited, even if the disease has an extraneous cause. Disease can at times be born with the child, and not manifest itself until later, the actual disease germ being present in the body all the time. Syphilis is the ailment most often showing this. Other diseases, such as typhoid and smallpox, may be contracted in the uterus, and the child may be born sick. It is probable that sometimes disease may be suffered and recovered from in the mother's womb, and the attack confer im- munity through later life.

Certain persons appear to possess all their lives an immunity to certain diseases, never contracting them in spite of frequent and direct exposure.*

^ Captain C. F. Craig and the •writer were quite unable to infect cer- tain indiyiduals, who volunteered for the purpose, with dengue, using methods usually successful and injecting doses of infected blood many times as great as would be received in natural infections.

PREDISPOSING CAUSES OF DISEASE 149

Certain nervous affections have no known cause but heredity, the disease appearing in the affected family with great regularity. "Bleeders," persons who bleed excessively or fatally from very trifling injuries, in most instances inherit the tendency, and in a curious way, as it usually descends only through females to manifest itself in males. The drink habit is often spoken of as inher- ited, but this is probably not the case. An unstable nervous system, which allows its possessor to fall more readily a victim to drink or other excesses, is inherited. It is common observation that types of body are in- herited, that children look and are built like their parents, and it is but natural that they should be pre- disposed to the same diseases, so far as bodily conforma- tion exercises any influence.

That this does exercise an influence is indicated by the table quoted on page 5, as well as by popular belief. The common remark that such a man looks as though he might have apo- _ ^ plexy any day, or such another man will ^

probably die of consumption, are based on facts long noted by physicians and the public. It is partly for the purpose of eliminating persons so predisposed to disease that the government demands not only that each man shall be in good health at the time of his enlistment, but that he shall also conform to certain standards not having much bearing on his present efficiency.

Certain diseases are known generally as those of childhood, as they are so rarely seen in persons beyond that age. Scarlet fever, measles, whooping- cough, and diphtheria may all occur at ° other stages of life, but it is with ever-decreasing fre- quency that they do so, and the phrase is, in general,

150 THE CAUSES OF DISEASE

correct. On the other hand, cancer, apoplexy, cataract, and several other troubles are so nearly confined to aged persons that they may be called diseases of old age. Certain infections are seen principally in early adult life, so that it is the young soldier that usually shows them in the military service. Among them we may mention typhoid, gonorrhoea, syphilis. The ques- tion of age is related to that of recklessness and folly, and it is partly for this reason that the young are in general more disposed than the old to infectious dis- eases. The prospects of recovery from an illness are also influenced by age. Pneumonia and injuries are much more serious in an old than in a young man. On the other hand, diabetes and epilepsy are not usually 60 serious in elderly persons as in children.

Certain persons are born with peculiarities of person that render them particularly liable to certain diseases,

_ , and no adequate explanation can be offered

Personal /.to n ^

_ for them, oome persona cannot eat nsh,

others strawberries, others eggs, without

becoming sick. A large number of persons

have such a susceptibility to the effects of certain

pollens that they must leave their homes when these

pollens are ripe, or suffer from hay fever. Some men

suffer from asthma if they go about a stable or ride

behind a horse, others are made sick or faint by the

presence of a cat or the odor of its urine. Of two healthy

men, one may suffer great discomfort after taking a

tenth of a grain of iodide of potash, while the other

can take three hundred times as much and not suffer

at all. Many of these peculiarities are now believed

to be examples of anaphylaxis, of which mention will be

made in the next chapter. It is quite probable that re-

PREDISPOSING CAUSES OF DISEASE 151

lated phenomena influence the development and course of infectious diseases.

Worry, fear, and homesickness strongly predispose to, if they do not actually cause, mental and nervous diseases. They also appear to predispose __ . to infectious diseases, possibly by lowering the general resisting powers and influenc- ing the circulation.

The aphorisms of all languages recognize the value of training in almost any occupation or pursuit in life. Military authorities recognize it by the fact _ . . that they require the soldier to spend years °

in training. It is not less valuable in sanitary matters than elsewhere. The child or the man who is trained to reason, to obey, and to conduct himself properly, is in much less danger from infectious diseases in camp or elsewhere than is the reckless, disobedient, or head- strons: individual who knows no law but his own will and appetite. It is the latter who drinks bad water, eats poor food, contracts venereal disease at each op- portunity, urinates and defecates in forbidden places, avoids vaccination, seeks alcoholic indulgence, sleeps without his mosquito-net, spits on the floor, and is otherwise a source of much worry and mischief. It is because of this lack of training in hygiene that re- cruits are so apt to become sick when brought into camp, and, what is worse, to scatter their sickness in all directions. As training in hygiene increases among officers and men with increase of knowledge, the results show in the sick report, and it is not probable that tlie evil conditions of the camps of 1898 will ever be re- peated in camps of the regular army. Whether or not they will be repeated in large camps of volunteers

152 THE CAUSES OF DISEASE

remains to be seen, but it is improbable, as we know how to prevent them and hope to be able to do so.

Lack of training on the part of troops is the most important predisposing cause of disease in armies. It is the duty of all officers, of whatever rank or branch of the service, to endeavor to overcome this defect, for which they are mainly responsible. The fact that a man is ignorant or headstrong at the time of his enlistment does not justify his being so a year or three years later. Medical officers should be required to give lectures or other instruction, but the company officer should see that example and wise precept are so constantly before the minds of his men that hygienic living becomes a matter of habit.

Aside from habit in the large sense just used, many small and unimportant personal customs have an influ- ence in predisposing to disease. Eating raw meat predisposes to infestation with tri- chinaB or with tapeworms, carelessness in hand-washing increases the liability to many infections and poisonings. The habit of going barefooted may be of very great importance in predisposing to plague and hookworm disease. Careless habits in the disposal of waste are responsible for so many sanitary ills as to make it evi- dent that the main purpose of sanitary training is the establishment of proper habits.

The influence of race as a predisposing factor of dis- ease is closely related to that of heredity, habits, and environment, but race in itself exercises some influence. The reason for this is not always known, but in some instances it is probably due to long racial exposure to certain diseases, whereby only the more resistant strains or families survive. At

PREDISPOSING CAUSES OF DISEASE 153

other times it is probably the case that the disease in question may be uniformly incurred in childhood, and so confer protection through later life. Whatever the reason, Cubans and West African natives are less sus- ceptible to yellow fever than Americans and Europeans. Jews are especially subject to diabetes, and negroes are much more apt than other peoples to suffer from keloid, a form of tumor.

Exposure to inclemencies of weather predisposes to numerous diseases. Tonsillitis, pneumonia, rheumatism, and influenza are all germ-diseases, yet the _,

frequency with which they are ascribed to ^

• siiiro

wetting or cold shows that these influences

are not without effect. The germs causing pneumonia, diphtheria, spinal meningitis, and tonsillitis may be present in the mouths or noses of healthy people and produce no symptoms, yet after exposure the person may sicken. Similarly, a person may carry the organisms of malaria or dysentery, and only become conscious that he is ill after a wetting or chilling. There is a growing belief that nearly all tuberculosis infections are received in early life, and that the appearance of the disease only at a later period is due to a lowering of resistance at that time, whether by an attack of typhoid or measles, by hard work, poor food, exposure, or other cause.

Injury predisposes to very many diseases. Pneu- monia, meningitis, and typhoid, of general diseases, may follow injuries in such a manner as _ . to appear related to them. Abscesses, kid- ^

ney and liver troubles, and tumors may follow injuries that do not break the skin, while anthrax, erysipelas, most suppurations, " blood-poisoning," hospital gan- grene, lockjaw, hydrophobia, and some other affections

154 THE CAUSES OF DISEASE

are preceded by breaks in the skin in nearly all in- stances, though these may be so small as not to be noticed at the time. It is through the wounds that the disease-producing organisms gain entrance to the body. In the strict sense it is also through wounds — insect bites — that malaria, yellow fever, plague, and sleeping sickness are transmitted. The great class of suppura- tions, however, are the principal diseases following in- jury, and the proper use of the first-aid packet for the purpose of preventing them has almost done away with one of the greatest horrors of war.

Injury may also act as a means of diffusing and gen- eralizing an affection previously isolated and relatively harmless. It may rupture an abscess due to appendi- citis, and so give rise to general and fatal peritonitis, or it may loosen the infected clot in an inflamed vein, and cause acute general " blood-poisoning."

As is shown in Part I of this book, the soldier's environment includes so much that it must exercise an . influence in predisposing hira to, or pro-

tecting him against, nearly all sorts of dis- eases. It is so large a matter that it cannot be adequately mentioned in a paragraph, and the whole subject of hygiene touches on it. The consideration of some phases of it occupies the remainder of this chapter.

There are quite a number of " occupation diseases," so called because their development depends on injury _ due to the employment of the individuals.

4. ^ Among such diseases may be mentioned writer's cramp, painter's colic, chimney- sweep's scrotum, housemaid's knee, and many others. During and after the Civil War a certain type of dilated and irritable heart was known as soldier's heart,

PREDISPOSING CAUSES OF DISEASE 155

and In the stress of a hard campaign many more cases may develop. In the early months of 1899, when the State troops were doing much hard marching in the Philippines, many such cases were seen. Occupation has a great effect, however, in other and less obvious ways. Thus it may expose a soldier to mosquito bites and so predispose him to malaria, yellow fever, or dengue; it may put him on guard in a prison, where he will contract typhus or relapsing fever. Men work- ing about stables are more apt than others to suffer from lockjaw after wounds, as the germ occurs in horse-manure. Occupations involving the breathing of much dust, such as marble-cutting, scissors-grinding, and some weaving, predispose to tuberculosis. Seden- tary occupations may impair digestion, allow muscles to atrophy, and cause hemorrhoids. Callings involving great strains or exertion predispose to diseases of the heart and blood-vessels. It is stated that the majority of Japanese jinricksha men are dead or invalids from circulatory diseases before they attain the age of forty. Occupations causing much worry or nervous strain predispose to nervous exhaustion. Overwork in almost any calling may predispose to disease, either by lower- ing or exhausting the general resisting powers of the body, or by exhausting the nervous supply.

The quality of the air-supply is very important as predisposing to disease, by its temperature, dryness, or purity. Too great heat, especially if moist, . causes much discomfort and may result in heat-exhaustion, heat-stroke, and death. Rooms that are too hot cause the men to sweat and to expose them- selves unduly to cold or draughts, which may result in congestions of the lungs or kidneys. Booms that are

156 THE CAUSES OF DISEASE

too cold allow the body to become chilled on the sur- face and congested internally, making easy the devel- opment of coughs, sore throat, and other troubles. In barracks, however, such troubles are usually more closely related to foulness and contamination of the air than to its temperature. One case of sore throat in a squad- room may sufi&ce to contaminate the air and expose every man in the room to disease if the ventilation is poor. This condition is aggravated with every increase in crowding. Carbon dioxide and other waste-products of the body may also make the air poisonous without considering infection.

Foggy or damp air predisposes somewhat to rheu- matism. That which is too dry causes dryness and irritation of the respiratory surfaces. Dusty air intro- duces many infections, among them tuberculosis, and it is for this reason that spitting on floors or streets is very dangerous. The spit dries and is pulverized, and eventually becomes dust, in which condition it may be blown or inhaled into sound noses or throats, carrying with it the disease-producing germs. Dust-laden air is responsible for many more " colds " than is cold itself.

The use of contaminated water predisposes, of course, to water-borne infections. In addition, the use of very

hard water or of water containing chemi-

cals may so disturb the digestive organs as to make infection easier. Excessive water-drinking dis- turbs the digestion and causes unnecessarily profuse sweating and urination ; deficiency of it causes irrita- tion of the kidneys and bladder, constipation, and general insufficiency of waste elimination. Greater in- sufficiency of course causes direct suffering from thirst.

Aside from the very numerous infections conveyed

PREDISPOSING CAUSES OF DISEASE 157

by uncooked or improperly cooked foods, the kind, amount, and preparation of the articles used have so great an influence on health as to make the _

subjects of catering and cookery worthy of the company officer's best thought. He should learn what foods are good, their digestibility, food-values, cost, and the amounts to be furnished. The method of preparation should be such as to make them attractive and digestible. The ration forms an excellent basis.

Excess of food predisposes to stomach and intestinal disorders, to gout, obesity, vascular and kidney diseases, and to various forms of auto-intoxication, or self-poison- ing by waste products. Insufficiency of proper food leads to weakness, loss of flesh and a lessened resistance, that renders infections more easy. Great epidemics of typhus and relapsing fever have followed famine and depriva- tion so many times as to earn for them the title of famine fevers, and our present knowledge that they are louse-borne enables us to appreciate the influence of misery in lowering physical and moral tone.

Alcohol is the direct cause of such diseases as delirium tremens, alcoholic neuritis, and gastric catarrh ; but it ia also a predisposing cause of many other diseases, — of the blood-vessels, heart, kid- neys, and brain. It also predisposes to infections, both by making its user careless in regard to them and by lowering the resisting powers. Drunkards are especially subject to pneumonia, and are also especially un- favorable subjects for that disease. The chronic gastric catarrh of the old alcoholic may make him an easy victim for cholera or typhoid. Alcohol predisposes to heat-exhaustion in hot and to freezing in cold climates.

158 THE CAUSES OF DISEASE

Insufficient or excessive clothing may predispose to disease as do heat and cold. Insufficient covering in the tropics may lead to severe sunburn, or, if ° of the head or spine, predispose to heat- stroke. Lack of foot-covering not only leads to injury of the feet, but predisposes to diseases that usually enter through the skin of the feet, including hookworm dis- ease, chiggers, Guinea worm, and plague. Insufficient clothing may also predispose to mosquito-borne diseases. Excessive clothing may predispose to heat-stroke, ex- haustion, and diarrhoea, and this is especially true when men are turned out for inspection or drill in too heavy uniforms.

Warm baths, if followed by exposure or chilling, may predispose to disease, as may cold ones in persons who do not react promptly. Insufficient bathing ° predisposes to skin diseases, especially in hot countries ; bathing in polluted waters, to water- borne infections. In addition to typhoid, dysentery, cholera, and common intestinal worms, there is reason to believe that schistosomum disease — infestation with a worm that lives in the veins of the liver, and causes bleeding and other serious bowel and bladder symp- toms— may occur during bathing, the young parasites entering through the skin. This disease is widespread in Africa, and varieties of it are seen in the West Indies and the Philippines, so that it may yet assume impor- tance with us.

The use of dirty water also predisposes to skin dis- eases, as noted in regard to the oft-bathing Japanese. The exposure incident to bathing in streams may in- crease the liability to diseases conveyed by mosquitoes and other insects.

PREDISPOSING CAUSES OF DISEASE 159

Natural sleep in proper amounts is an important factor in the prevention of disease ; the lack of it causes weakness, exhaustion, and depression that render infection and injury easy matters. °

Insufficient sleep for a long period of time causes ner- vous disorders and predisposes to insanity. Sleeping in improper surroundings may greatly increase the liability to disease through chilling, wetting, exposure to mos- quito bites, and in other ways. Sleeping in close contact with persons suffering from certain contagious diseases would strongly predispose to them, as would sleeping in the beds or clothing of such persons.

Poor sanitary police is a feature of poor military training, and predisposes to all of the epidemic forms of infectious diseases. It does this by allow- ing infected dust and papers to blow about and pollute the air, by allowing soil and water con- tamination, by leaving or providing breeding-places and food for flies, fleas, mosquitoes, rats, and other vermin, and by failure to remove sources of infection. In these ways it encourages the development of typhoid, cholera, dysentery, yellow fever, plague, pneumonia, influenza, tuberculosis, and other diseases.

By attention to police and general cleanliness of per- sons, houses, and neighborhoods some diseases that for- merly occurred in great epidemics have been almost ban- ished from civilized countries, and even famine does not bring them forth as in earlier times. Typhus and relaps- ing fevers are striking examples. Tuberculosis and other diseases have been reduced in part by similar measures.

As the best police is possible only when all unite in striving for it, it is essential that line officers and en- listed men should become interested in the sanitary

160 THE CAUSES OF DISEASE

importance of the question, and should look on good policing as a source of pride, comfort, safety, and effi- ciency.

A poor camp-site may constitute a predisposing cause to many kinds of disease. It may expose the men to fog, unnecessary dampness, wind and cold, or to *^" dust and heat, to mosquitoes, flies, fleas, bad water, or contaminated soil, and through these factors promote the development of the worst camp-diseases. While it is highly desirable, therefore, to select as good camp-sites as can be obtained, it must ever be borne in mind that proper sanitary precautions may nullify the evil effects of a bad site, and that neglect of them is almost certain to destroy the value of a good one. Polluted sites, those that have been much used by troops, and those that expose the men to bad water and disease-bearing insects are particularly to be avoided, as these factors predispose so strongly to various diseases that only the best trained and disci- plined troops may come off unharmed.

Practically every case of infectious disease is derived from some other one, and it is therefore obvious that ^ the existence of one case constitutes a f ac-

FfOSGXlCO

tor predisposing to more. One man with typhoid, cholera, smallpox, or plague, in a camp, constitutes a danger to the entire command, and this fact is so well recognized in these and other dis- eases that it forms the basis of the entire system of quarantine and isolation. The origin of individual cases of infectious diseases may be difficult to trace, the ty- phoid-carrier, the unsuspected syphilitic, or the man with a slight diphtheria, not even realizing that he is sick, and unknowingly spreading disease broadcast. One

PREDISPOSING CAUSES OF DISEASE 161

disease may predispose to the development of another or to new manifestations that are spoken of as new diseases. Thus blood-poisoning, gonorrhoea, typhoid, and, more particularly, acute articular rheumatism, predispose to valvular heart-disease, syphilis to cer- tain affections of the nervous system and to aneurysm, diphtheria to varying forms of paralysis, and amoebic dysentery to abscess of the liver.

CHAPTER IX

THE IMMEDIATE OR EXCITING CAUSES OF DISEASE

The immediate or exciting causes of some diseases, among which may be mentioned such important ones as scarlet fever, measles, yellow fever, and typhus, are un- known, but those that are known are so numerous and of such varied character that they could not possibly be discussed in this chapter, even if it were desirable that they should be. We will therefore omit all discus- sion of the causes of large and important groups of diseases, and consider only briefly the various classes of disease-producing factors which it seems it would be interesting or profitable for the company officer to know. Numerous as they are, such factors may be gathered into a few groups.

Of these groups, the first to be considered is that of mechanical causes, and, of such, traumatism or violence is probably the most important. Like the other components of this group, it may pre- dispose to disease, but it is also the direct or exciting cause of many ills, among which we may class practically all varieties and instances of wounds, from the slightest abrasion to the most extensive shell- wound, fractures, dislocations, and bruises. Concussion, laceration, or rupture of internal organs, such as the brain, spinal cord, liver, kidneys, stomach, intestines, or bladder, may result from blows or other injuries that cause no break in the skin, or even, in rare instances, leave no external mark. At times the violence may be

EXCITING CAUSES OF DISEASE 163

slight in degree, and apparently out of all proportion to the resulting damage. Thus, a relatively slight blow on the chin may be so directly transmitted to the brain, and so jar and shake it, as to cause immediate and deep unconsciousness; or a blow over a distended stomach or bladder may rupture it and cause death, to the great surprise of all witnesses. Or the evil effects of the injury may not be manifested at once. A knee or hip, for instance, may be injured and give rise to no symptoms at the time, but later cause prolonged suffer- ing or lameness ; or a man may receive a severe blow on the head or the abdomen, and continue at his work all day, yet he may have received an injury from which he will die in a few days. Officers should, therefore, exercise much care and forbearance before they pro- nounce a man a malingerer because some accident from which he suffered appeared trivial or harmless. Vio- lence may be so transmitted as to manifest its effects on a distant part. Thus a man may fall from a height and land on his feet, and yet fracture his skull ; or he may fall on his hands and fracture his collar-bone ; or he may receive a blow on the right side of the head and suffer a laceration of the left side of the brain. As the manifestations of violence may be almost infinite in variety, so may its effects. Pressure may also cause disease in a variety of ways. Applied to the feet it may cause deformity, bunions, or corns ; to the waist, displacement of internal organs ; to a nerve, as by a bullet or a bone-fragment, paralysis or great pain; applied to a blood-vessel, it may cause ulceration and rupture, with fatal bleeding, or it may cut off the blood- supply of the part to which the vessel runs, and cause gangrene or death.

164 THE CAUSES OF DISEASE

Heat and cold^ besides predisposing to disease, aa shown in the preceding chapter, may directly cause injuries varying from the slight reddening of the mild- est burn or chilblain to the loss of entire limbs, or of life itself. They, as well as violence and pressure, in addition to the immediate damage done, may cause life- long suffering or deformity, from the formation or contraction of large scars, or by means of secondary infections.

Increase or diminution of atmospheric pressure may cause disease or death, the former in divers or caisson- workers, the latter in mountain-climbers or balloonists. In the case of increased pressure, the trouble most often comes from too sudden return to normal pressure, which allows the liberation of nitrogen gas in the blood.

Electricity may cause disorders varying from slight pain or nervous disturbance to deep burning or sudden death.

Mechanical injuries not usually thought of as such are exemplified by the rashes or irritations due to han- dling or contact with some caterpillars or moths, and are caused by the introduction and retention in the skin of the minute barbed hairs that partly cover the creatures.

The group of chemicals that cause disease or death

is very large and embraces practically all poisons. They

, may occur in any form, gaseous, liquid, or

solid, and may enter the body in any way,

as by inhalation, by mouth, by the rectum, through the

skin, or through wounds.

Gaseous poisons usually enter the system by inhala- tion. Those most commonly causing trouble are carbon dioxide, water gas, coal or charcoal gas, or carbon monoxide. These and other gases may produce death

EXCITING CAUSES OF DISEASE 165

without occasioning great suffering. Another group, in- cluding formalin, ammonia, chlorine, and sulphurous fumes, cause marked irritation of the respiratory tract and excite efforts at escape, so that they are, in that respect, less dangerous. Certain others, such as some compounds of arsenic or phosphorus, may cause poison- ing by inhalation in small amounts, and be very diffi- cult to trace. Chloroform and ether usually, and wood- alcohol and some other liquids occasionally, enter the body in a vaporous or gaseous form. Gases may produce death in any one of several ways : by acting mechan- ically to exclude oxygen, and so cause suffocation, as in the case of nitrogen ; by forming combinations with the blood to prevent its taking up oxygen, even if it has the opportunity, as in the case of charcoal gas ; by caus- ing paralysis, or change of nerve-tissue, as in the case of chloroform or wood alcohol ; by causing such irri- tation of the glottis as to close it by swelling, and so induce suffocation, as does ammonia.

Liqvid poisons may also cause injury or death in a great variety of ways. The group includes a large number of substances. Some of them, such as sulphuric and nitric acid^ do injury by their strong corrosive properties ; others, as alcohol, act on the nerves. They usually enter the body by way of the mouth, but, as in the case of the acids, they may act on the surface, or enter through wounds.

The poisons occurring in solid form are even more numerous than the others, and they enter the body in the greatest diversity of ways, and produce manifold symptoms. General poisons include a great variety of substances, such as arsenic, phosphorus, antimony, mer- cury, lead, and a great many more. They may be taken

166 THE CAUSES OF DISEASE

knowingly with good or evil intent, or in ways not known at the time, and often difficult to trace. The amount taken at one time may be almost infinitely small, yet its frequent repetition may result in poison- ing. Thus, a painter may contract lead-poisoning from the minute amounts of lead getting on his food from unwashed hands, a beer-drinker from the lead taken into solution from lead pipes through which the beer is drawn.

Alkalies, such as caustic potash, caustic soda, lye, and quicklime are powerful irritants or caustics.

Vegetable poisons include substances producing dis- ease or death in a great variety of ways. Some of the most common and familiar of these are opium, strych- nine, cocaine, and jimpson weed. Most of the enslaving drugs — alcohol, opium, cocaine, and others — are of vegetable origin. Habitual users of them may get to using enormous doses, some of them several times the amount that would be fatal to persons not so habitu- ated. Some vegetable poisons are very irritating to the skin and cause marked eruptions. Croton oil causes pustules that resemble those of smallpox. Poison ivy owes its evil qualities to an oil that occurs in and on the leaves and that causes the well-known inflammation of the skin.

Many of the chemical poisons are the products of germ action. Alcohol, the best known, results from the action of yeast cells on sugar. Ptomaines result from the action of germs on meats, fish, milk, and other food- stuffs. There are a great many of them, and their effects vary greatly. Some of them resemble drugs, such as morphine, strychnine, or atropine, in their action, and, as their presence may not be suspected at the time they

EXCITING CAUSES OF DISEASE 167

are taken into the system, the symptoms produced by them may prove very puzzling. It should be borne in mind that ptomaines may not be destroyed by boiling, and cooking should therefore not be depended upon to render partially decomposed meat safe. Many of them are harmless, but neither can that fact be depended upon to show that a given article of food is wholesome. Their poisonous character depends on the type of organ- ism producing them, rather than on the stage of decom- position. Thus one piece of meat may be quite rotten, and yet not poisonous, while another that is free from odor and presents a fairly good appearance may be very dangerous.

The foods that most often give rise to ptomaine poi- soning are those that have been preserved imperfectly, such as beef or fish in cans that have become perfo- rated or blown, cold-storage beef that is not well frozen or chilled, poultry imperfectly chilled, especially if it be undrawn, and imperfectly cured hams and sausages. The symptoms vary considerably, depending on the source, character, and amount of the poison ingested, but in most instances they include evidence of marked gastro-intestinal and nervous disturbances, such as vom- iting, diarrhoea, headache, dizziness, and cramps. Self- poisoning or auto-intoxication may be due to ptomaines or other decomposition products resulting from the putrefaction of food, occurring in the stomach or bowels, or to simple retention and absorption of poisonous pro- ducts which would ordinarily be eliminated, but which, because of constipation, kidney disease, or for some similar reason, remain in the body. Such poisonings are promoted by overeating, lack of exercise, and by ex- cessive drinking or smoking, as well as by diseases.

168 THE CAUSES OF DISEASE

Certain small organs of the body, known as the duct- less glands or glands of internal secretion, have a tre- _ . mendous influence on development and wel-

- . fare, and their injury or destruction may

It fll cause grave disease. Among such disturb- „ ances are exophthalmic goitre, due to excess

. . of secretion of the thyroid gland, and myx-

oedema and cretinism, the latter a form of idiocy, due to its absence. The most familiar instance* of the influence of internal secretion are seen in the absence of the usual sex characters in animals castrated or spayed wlien young, the absence of testicular or ova- rian internal secretion being responsible. The differ- ences shown in the development of a stallion and that of a gelding, of a bull and a steer, a ram and a wether, a normal bitch and a spayed one, are obvious to all.

Animal poisons^ in addition to the products of animal waste to which reference has just been made, include such substances as snake-venoms and those of stinging insects and spiders. These vary greatly in their com- position, and their effects range from the slight itching and burning of a mosquito bite to the agonizing deaths following some snake bites. The venoms are introduced through wounds, many of them being harmless if applied to the unbroken skin or even if taken by mouth.

Deprivation diseases have been discussed in the chapter on foods.

The most important group of the larger animal

parasites that infest man is that of the

.° intestinal worms. Their distribution is

. world-wide, and in some places they are so

prevalent and their effects so serious, that

they exercise very important influences on the mor-

EXCITING CAUSES OF DISEASE 169

bidity and mortality rates. They may be grouped in three classes: the flukes or sucking-worms, the tape- worms, and the roundworms.

Flukes or sucking-worms are not common parasites of man in our own country, but in some parts of the world they are very prevalent and cause serious illness. Several varieties occur in the Philippine Islands, and some of them cause death. One variety occurs in the lungs, and causes blood-spitting and cough that may lead to the belief that tuberculosis is present ; or it may lodge in the brain and cause paralysis or other cerebral symptoms. Other varieties live in the veins of the liver and may produce disease of that organ, while their sharp- pointed eggs lodge in or perforate blood-vessels of the bowels or bladder and cause bleeding, irritation, and other symptoms. This is a type of the schistosomum disease mentioned in the preceding chapter. Although it is claimed that this particular class of flukes may enter the body through the skin, th© usual history of the flukes is that they pass a part of their lives in the bodies of snails or other small water-animals,^ and enter the hu- man body only by way of the mouth. Even though both methods of infection be possible, the obvious means of prevention are, first, to prevent infected or egg-bearing feces or urine from reaching water ; second, to boil or otherwise sterilize the drinking water ; third, to abstain from bathing in infected water unless it also be boiled or filtered ; fourth, to avoid the use of uncooked foods that may have been contaminated by bad water.

The tapeworms are better and more widely kn^wn

^ Flukes in general, so far as their life-history is understood, have at different times four forms or stages and two or three methods of mol- tiplication.

170 THE CAUSES OF DISEASE

as human parasites. There are many varieties of them, but the best known are those large species ingested with beef and pork, though others are important, and some of these, such as the broad tapeworm from fish, may be very important in places. The life history of tapeworms, while not so complicated as that of flukes, involves, in most instances, residence in two animals, and knowledge of it enables us to understand the man- ner in which infestation occurs, and the method of avoiding it. Life begins in the eggs, which are passed from the worm into the bowel-contents of its host, and thence to the outer world. Here they may fall into water or on vegetation, or the excrement itself may be ingested by animals. At any rate, the eggs must, in one way or another, get admission to the alimentary canal of the second host, for which purpose a particular species of animal is necessary. In the case of the beef tapeworm, this host is the ox, in that of the pork tapeworm, the pig. Rarely this development may occur in other ani- mals, or in man himself, but ordinarily development will not occur in any but the usual host. Having reached the stomach of this host, the embryo is set free when its enveloping shell is dissolved, and penetrates the wall of the stomach, whence it passes by the blood vessels to the liver, muscles, brain, or other part of the body, where, after undergoing some further development, it becomes the head and neck of a future worm, inclosed in a small bladder, like cyst or measle, from one fourth to three foui'ths of an inch in length and about one third of an inch in diameter in the case of the pork measle, and somewhat smaller in the case of the beef measle. If now the flesh of the infected pig or ox be eaten raw, or not cooked sufficiently to kill the worm, it may pass un-

EXCITING CAUSES OF DISEASE 171

harmed to the bowel of man and there attach itself and grow. The head and neck as ingested are very small, bearing comparison in size to a small pinhead and a piece of fine twine. From this head and neck the rest of the worm develops in the bowel. The part so developing consists of a great number of segments, at times hun- dreds, each flat and white, so joined together as to form a long flat ribbon that may attain a length of thirty or more feet, each segment having a nervous and alimen- tary system and male and female generative organs, and each developing, fertilizing, and discharging eggs, so that each tapeworm, though an individual, may be said to be also a community. It may be readily understood from the above that allowing pigs to act as scavengers of human ordure, as is often the case in the tropics, is not a wise sanitary measure. It was stated above that man might rarely be the measly host. In such cases he might become infected with eggs by means of contaminated water, or of lettuce or other green vegetables manured with human feces, by getting the minute eggs on his hands in water-closets or from his own stool, or by having them pass from the bowel to the stomach during vomiting. Several other varieties of tapeworms may infect man, — one of the most dangerous, and one for which man may shelter the cystic stage with fatal re- sults, being derived from the dog, and another danger- ous one possibly being derived from the rat, which may deposit the eggs on food articles with its feces.

Many varieties of roundworms infest man, and their life-histories vary greatly. A few varieties will be briefly discussed in order to indicate more clearly the neces- sity of certain sanitary precautions. Those most com- monly inhabiting the human intestine — thelarge^wJiite

172 THE CAUSES OF DISEASE

roundworm^ the loJilpworm^ and the pimoorm or seat- worm — require no other host, and infection occurs, directly or indirectly, from man to man. The egg9 are laid in the feces and pass from the anus, whence they may get on the hands, into drinking water, or on green vegetables, and so obtain entrance to the mouth and stomach of the same or another person. The embryos are set free in the stomach or intestine and develop into adults. Probably the most common method of in- fection is by means of polluted water. Children and adults who are infested with seat- worms may reinfect themselves many times, by reason of the fact that these worms often crawl from the anus and give rise to most intense itching, in the efforts to relieve which the hands and nails pick up many of the microscopic eggs, which may later be transferred to the nose or mouth.

The hookworms are probably the most important of all the worms infesting man, both because they may and do infect the great majority of the inhabitants in some tropical countries, and because they so seriously reduce health and strength. In Porto Rico, the Philip- pines, and our own Southern States, infestation with these worms is common, and thousands and thousands of persons are debilitated or incapacitated, and have their resistance to other disease reduced by it, with the result that industrial progress is delayed and physi- cal degeneracy and high sickness and death-rates pro- moted. Formerly it was believed that infestation with this parasite occurred in the same manner as with those just described, but it is now generally admitted that it usually, if not always, occurs in another way. The usual history is about as follows : The adult female pro- duces a great number of eggs that pass out from the

EXCITING CAUSES OF DISEASE 173

host with his feces. If passed on moist, warm earth, the eggs hatch and liberate microscopic embryonic worms which eat feces or other organic matter, live and grow in the moist earth, and eventually, if fortu- nate, find an opportunity to get on the bare feet or other skin-surface of a person, penetrate the hair fol- licles and tlie true skin, producing itching and irrita- tion, and causing "ground itch," gain access to the lymph or blood-vessels, and are carried, by way of these channels, to the lungs. Here they leave the blood and pass out on the mucous membrane, crawl up the wind- pipe to the throat, from there down to the stomach, and then to the small intestine, where they take up their abode, reach adult life and a length of one third or one half an inch, and in turn produce eggs to infect more polluted soil. In addition to this, they produce a very serious anaemia or thinning of the blood, which gives rise to weakness, shortness of breath, dropsy, mental dullness, and, in children, checked develop- ment and stunted physique and mentality. Such con- ditions impair the body's resisting powers, and the vic- tims more readily succumb to malaria, dysentery, and other diseases.

The short outline of the life-history of the worm just given indicates the wisdom of the following measures to prevent the spread of the infestation: first, treat- ment of all infested; second, proper disposal of feces to prevent soil-pollution ; third, the wearing of shoes in infected regions ; fourth, the use of pure drinking water.

Trichiniasis is a disease produced by infestation with a kind of roundworms, trlchmce, that presents still another life-history and method of infestation.

174 THE CAUSES OF DISEASE

The trichlnse are small worms about a sixteenth of an inch in length that are natural parasites of the rat, but may also infest man and many other animals, including the pig and dog. The danger to man lies principally in the fact that the pig is a rather common host, and it is from that source that he derives his infection. The history is as follows : Rats become infested by eating their infested kindred, and they in turn may be eaten by pigs. The larval worms are encysted in the muscles, as will be described later, and are set free in the pig's stomach, when the muscle and cyst are digested. They then pass to the bowel, where they take up their abode, mature, and bore into or through the intestinal wall to the lymph spaces, where they deposit their numer- ous progeny, averaging about fifteen hundred in num- ber. These are carried along by lymph or blood-streams, or possibly by their own activity, to various parts of the body, finally penetrating the muscle fibres and set- ting up an irritation that results in the formation of little capsules about them. Here they live quiescent, but capable of development, for an indefinite time, occasionally for years. Too often, however, this rest is shortened by the death of 'the pig and its later con- sumption by man. If such consumption is preceded by thorough cooking no harm will result, as the heat will destroy the worms ; but if, as is sometimes the case, the meat be eaten raw or underdone, the larvae are set free in the man's stomach as the others were in the pig's, and he in turn develops adults, has larvae scattered through his muscular system, and suffers from pain, fever, symptoms resembling typhoid, and, possibly, death.

Filaria^ a. roundworm whose larvse circulate in the

EXCITING CAUSES OF DISEASE 175

blood, presents a still different history and method of entrance to the body. For at least two varieties, whose development has been pretty well traced, the history is as follows : The young or embryonic forms are imbibed with blood by mosquitoes that bite infected persons. In the blood these embryos, which are about one eightieth of an inch in length, are inclosed in loose individual sheaths or capsules, within which they wriggle about very actively. After reaching the mosquito's stomach the blood containing them clots and they break through their sheaths, and, after about a day, through the stomach-wall. They live in the body of the mosquito, growing and maturing, for two weeks or more, at the end of which time they have increased to four or more times their original length, and have gathered in or about the fleshy part of the mosquito's proboscis. When the mosquito next bites a man they break through a thin part of the proboscis and pass through his skin by the small wound from which the mosquito is extracting blood. Once in the body, they wander in ways and parts unknown for an indefinite time, until they reach maturity, and, if both sexes be represented, begin to turn out embryos for other mosquitoes to ingest. The adults are very apt to take up their abode in lymph- vessels, and by their residence there they set up irrita- tion that leads to blocking or obliteration of the chan- nels and is thought to be the cause of lymph-scrotum, chyluria (milky urine), elephantiasis, and kindred troubles. Certain insect larvce that bear a resemblance to roundworms occasionally infest man. Blow-flies may deposit their eggs on meat that is left carelessly ex- posed, and, if they are not destroyed by heat, maggots may hatch from them and appear in the stools of per-

176 THE CAUSES OF DISEASE

sons eating it. Flies also deposit eggs, and maggots develop, on neglected sores, wounds, or ulcers, which may later be burrowed in many directions.

Screw-worms are the maggots of a small fly found in some of our Southwestern States, in Central Amer- ica, the Isthmus of Panama, and elsewhere. This fly deposits its eggs in the nostrils, or, occasionally, on other parts of sleeping persons, especially those afflicted with nasal disease or very foul breath. The maggots hatch out in a few hours and bore their way in all directions, causing great suffering and, in many cases, death. Among twenty-three cases reported from Arizona in the fly season of 1905, there were four deaths.

Some flies deposit their eggs on or in the skin of animals, and the larva develop there, constituting " warbles " in cattle, deer, and wild rabbits. Occasion- ally man is host, though this is rarely so.

Some insects burrow into or beneath the skin in their adult condition, and there nourish themselves and some- times deposit their eggs or their young. They cause irritation or disease. Among them may be mentioned the itch-mite^ jiggers or chiggers^ and many kinds of ticks. Itch was at one time a very widespread, com- mon, and intractable disease, but is no longer so.

Lice of various kinds are also less common than formerly, but are still seen often enough as human parasites.

Leeches are at times a great pest and cause much loss of blood, particularly in some parts of the Philip- pines, where they get on troops marching through the jungle, in great numbers. They may get on the body from water or from vegetation. Clothing is the main source of protection from them.

EXCITING CAUSES OF DISEASE 177

A number of very important and well-known diseases are caused by animal parasites of such extremely small size and so low in the scale of animal life jL/r:-,,,*.^ that they may, for our purposes, be re- A„;jj,ai garded as closely allied to the bacteria. In parasites fact, even scientists are not agreed as to whether some of them, for instance the germs of syphilis, yaws, and relapsing fever, are animal or vege- table. A brief consideration of some of the small ani- mal parasites and the diseases they cause may be helpful.

Malaria is the best known and most common of such diseases, and the parasites causing it are better known than most of the others occurring in man. There are at least three varieties of malaria, each caused by its peculiar t3'pe of organism, though these types have much in common. They all live in the blood and in its red corpuscles, when so small as to be almost in- visible with the microscope, and there grow to a consid- erable size, destroying the blood-cell and converting it into a mere shell and some pigment granules. In twenty- four, forty-eight, or seventy-two hours, depending on the variety of organism, they segment or break up into a number of small new organisms, the number varying from six or eight to fifteen or twenty, and also depend- ing on the type. These young forms are set free in the blood-stream with the breaking up of the shell of the blood-corpuscle in which they were contained, and in turn attach themselves to new red cells, to repeat the performance. Corresponding to the liberation of the swarms of young comes the " ague fit," or the malarial chill, fever, and sweat, and it depends upon the type of organism whether this comes daily, once in two days, or

178 THE CAUSES OF DISEASE

once in three. Various combinations of infections may make the chills appear to come very irregularly, but such irregularities are often explainable if the case be well studied. After a time the body develops powers of resistance that enable it to overcome the effects of the organism, and spontaneous recovery may occur. Or the recovery may be apparent only, and the disease may recur when chill, exposure, or other illness lowers vi- tality. Malaria causes many deaths, especially in the tropics, in India about one million annually ; but if a single infection is not fatal very soon, the tendency is to recovery, as the parasites cannot maintain their powers indefinitely unless they renew their strength (in some unknown way) by sexual reproduction, and that can only occur in mosquitoes of certain kinds. Minute differences can be detected among the para- sites of any kind of infection, and these are now known to mark sexual differentiation. If the right kind of mosquito bites the infected individual, these sexual differences become more marked in its stomach, and sexual conjugation there takes place. The impreg- nated female (this term is not accurate, but it conveys the idea) bores into the stomach-wall and undergoes a development which eventually results in the production of hundreds or thousands of young forms that finally find their way to the salivary glands and mouth of the mosquito, and enter, by way of the wound made by the insect, the next man it bites, and the cycle begins again in him. All malarial infections are conveyed in this way, and where there are not the right kinds of mos- quitoes the disease cannot originate. So far as known, man is the only animal, and mosquitoes of the sub- family anophalincB the only insects, that respectively

EXCITING CAUSES OF DISEASE 179

harbor and transmit malaria, and each derives its in- fection from the other. Each should therefore be kept away from the other.

Amoebic dysentery, so well known to our army because of the great amount of invalidism it has produced among our soldiers on tropical service, is also due to an animal parasite of microscopic size. This is a minute round mass of living substance endowed with the ca- pacity for motion, by virtue of which it inserts itself between the body-cells or wraps itself about them and digests them ; destroying tissue and giving off poison, it causes the formation of ulcers in the bowel, inflam- mation of the intestinal siu'face, bleeding, wasting, diar- rhoea, and, too often, death. Entering the blood or lymph-streams through the ulcers they make in the bowel, the amcehas may reach the liver and there set up the dreaded disease known as liver abscess. The amoebas enter the body in polluted water, and probably also on lettuce, radishes, and other vegetables that are eaten uncooked.

Sleejying sickness, a disease unknown in our posses- sions but caused by a parasite closely related to that causing the well-known and fatal surra of horses in the Philippines, is widespread in central Africa, and has caused tremendous loss of life there. The ororanism and disease are transmitted by the bites of tsetse flies.

Syphilis, known everywhere, is caused by an ex- tremely fine organism of spiral figure. This is about 1-2000 of an inch in length, and the thread that is twisted into the spiral shape, the organism itself, is about 1-100,000 of an inch thick. This extreme fine- ness, and the difficulty with which the germ stains, account for the fact that it remained so long undiscov-

180 THE CAUSES OF DISEASE

ered. This organism, which is called a Treponema^ is not known to occur elsewhere than in syphilitic sub- jects, but it occurs abundantly in lesions of the disease and is free on the surface of such moist sores as the open chancre and patches in the mouth. If from these it passes to wounds, cracks, or other open and moist surfaces on a healthy person, as may occur in kissing, sexual congress, or other contact, the disease is trans- mitted.

Yaws, a skin disease that occurs in the tropics, is caused by an organism indistinguishable in appearance from that of syphilis.

Many other diseases are produced by^animal para- sites, but it is unnecessary to consider them here.

Certain diseases, such as yellow fever and dengue^ are produced by unknown organisms that pass through fine filters and are probably so small as to be invisible to our microscopes ; yet the course and history of the diseases point to an animal rather than a vegetable cause.

The disease-producing vegetable parasites are of three classes, wowZcZs, yeasts,siud Saci^eWa, all microscopic in size and all of them germs. The moulds _. ° and veasts are of minor consequence as

compared with the bacteria, and cause rela- tively few diseases, and those principally of the skin. Fatal general infections by germs from both of these classes have, however, been reported. Persons who have served in the tropics recall how difficult it is there to keep shoes, clothing, trunks, and many other articles from moulding or mildewing, especially during the rainy season. Heat and moisture afford such excellent conditions for growth that a pair of shoes will turn

EXCITING CAUSES OF DISEASE 181

green in a very short time. As related vegetable forms are responsible for many of the most common skin- diseases of the tropics, the fact helps us to understand the prevalence of the latter. Not all moulds are harm- ful, and most of them are mere surface growths. The mistake is occasionally made of rejecting a quite good ham, for instance, because it is mouldy on the outside. Such mould can be trimmed off with the rind, and does not injure the meat. Roquefort and some other cheeses are dependent on moulds for their flavor, and are not good if these be absent.

Bacteria^ however, are the best known of the causes of disease, so well known as such, in fact, that two erroneous ideas have arisen in consequence : one, that all bacteria produce disease, the other that all disease-producing germs or micro-organ- isms are bacteria, or, to touch a still greater error, bacilli. Bacteria are microscopic, one-celled organisms of vegetable nature that multiply by simple fission. So far are they from being universally harmful, that life would soon disappear from the face of the earth if all bacteria were killed. This is because of the fundamen- tal difference that exists between bacteria and the larger forms of vegetation. All animal life is main- tained directly or indirectly by vegetable life, even the lion and tiger being dependent on the herbivorous deer and similar animals. Most vegetable life draws its sub- stance from the elements and simple compounds of the earth, air, and water. In other words, grass or a tree cannot eat dead grass, meat, or other highly organized substances, until they are first decomposed and broken up into the elements and simple compounds indicated, and returned in those forms to the earth, air, or w^ter.

182 THE CAUSES OF DISEASE

For this purpose bacteria are necessary, and without their action the earth would soon be covered with dead animals and vegetables, the fertility of the soil would be exhausted, and life would be choked out by the ac- cumulation of its products. Because of this difference and the fact that bacteria do not contain cellulose, as do ordinary plants, it has been proposed to class them as a separate kingdom and regard them as neither ani- mal nor vegetable.^

Bacteria are found practically everywhere in nature, and many trades and industries are dependent on their presence. They are classified according to shape, group- ing, action, and other qualities. Thus some are called putrefactive, others nitrifying, and others pathogenic or disease-producing. The more common forms are desig- nated as cocci, or little balls, bacilli^ or little rods, and spirilli or vibrios, or little spirals or pieces of spirals. Cocci in pairs are called diplococci ; bound together in chains, streptococci ; gathered into bunches like grapes, staphylococci ; and, as each organism tends to grow al- ways in the same way, such names become permanently attached as more or less generic. Thus we speak of the streptococcus of erysipelas, the diplococcus of pneu- monia, and the yellow staphylococcus of suppuration.

Bacteria may also be cerobic or anaerobic ; the for- mer unable to grow without oxygen, the latter with it. Tetanus or locljaw is caused by an anaerobic bacillus, and that probably partly accounts for the fact that it is

^ " It has been generally assttmed that bacteria are low fonns of plant life, but researches . . . show that bacteria contain no cellulose and are particulate, unshielded proteins and consequently are more nearly related to low forms of animal life. I should not classify bact©' ria as either plants or animals." — V. C. Vaughan.

EXCITING CAUSES OF DISEASE 183

most apt to follow small deep wounds, such as nail- punctures, to which the air does not have free access.

Reproduction among bacteria is by fission or simple division. One bacillus divides crosswise into two, the two into four, and so on ; and so rapidly does the proc- ess advance, that under favorable circumstances the increase amounts to uncountable millions or billions in a day. The rapidly multiplying individuals may be bound together in gelatinous masses that are of con- siderable size, at times forming a skin-like layer many yards in extent. When conditions are less favorable, as when all the food-supply is exhausted, the temperature too high, or harmful chemical substances present, the bacteria usually die ; but some varieties may preserve themselves under such circumstances by the formation of spores. These may be compared to the seeds of larger plants in that they are much more resistant to heat, cold, and other harmful influences, and, after sur- viving such trials, may again give rise to growth. An- thrax bacilli, for instance, are readily destroyed by heat, but their spores will withstand boiling for some time. In preparing media for the cultivation of bacteria it is therefore the practice to sterilize them at a temper- ature higher than that of boiling water, or to use that temperature on three successive days. In the latter event the bacteria develop from the spores after the first sterilization and are killed in their less resistant forms. The amount of heat required to destroy bacteria, what is called the thermal death-point, varies greatly with the species. Some organisms found in water, none of which, fortunately, produce disease, flourish in a high temperature. All disease-producing organisms, except those in spore form, are promptly destroyed by boiling,

184 THE CAUSES OF DISEASE

and many of them by a lower temperature. Few ordi- nary organisms will survive a temperature of 67° C. for more than a short time, and this fact gives the pro- cess of pasteurization^ as applied to milk, its value. , This is the process whereby milk is heated to a point between 66° and 70° C. and maintained at that tem- perature for ten or fifteen minutes. This kills the dis- ease-producing organisms, without changing the taste and character of the fluid as does boiling. For the same reason, satisfactory results have been obtained in the British service with a camp water-heater that raises the supply to 85° C. for only a very short time.

Moisture is necessary for the growth of bacteria, and drying checks their growth even when it does not kill them, as it does many varieties. Being solid bodies heavier than air, bacteria are not given off from moist surfaces. Occasionally they may be thrown into the air with droplets of water by the bursting of bubbles, but in general a tubfuU of bacteria-laden water would not endanger the purity of the atmosphere. On the other hand, dried or partially dried bacteria may be blown about as dust and do much harm. Cuspidors and water- closets should therefore always contain water. Sunlight is a great enemy to most pathogenic bacteria, some of them, for example the cholera germ, being killed by a very brief exposure to it, and all being injured by it. Many chemicals, such as bichloride of mercury and carbolic acid, kill bacteria when brought into contact with them. Such mistakes are often made as that of regarding a stool disinfected because some antiseptic solution has been poured over it. As a matter of fact, the antiseptic in such a case is only brought in contact with the surface of the fecal mass and the great bulk of it is quite as dangerous as before.

EXCITING CAUSES OF DISEASE 185

One variety of bacteria may tend to destroy another. Thus typhoid bacilli will keep alive much longer in sterilized than in contaminated water, the common water-organisms in the last case crowding them out ; and fecal matter arid its contained bacteria are very quickly made to disappear if mixed with dry earth containing an abundance of nitrifying bacteria, while, if mixed with ashes, which are sterile because burned, they persist much longer. This warfare of bacteria has had exploitation because of the interest attach- ing to the recommendation that certain milk-souring bacteria be ingested for the purpose of crowding out from the intestines more harmful varieties, and so less- ening the danger of poisoning by the products of these. This explains the occasional excellent effects of the use of buttermilk as a diet.

On the other hand, one variety of bacteria may in- crease the danger or power of another variety. Thus the tetanus bacillus, being anaerobic, cannot grow in the presence of oxygen ; but if introduced into the body with a variety of organism that uses a great deal of oxygen, the latter may soon bring about practically anaerobic conditions in which the former can flourish.

The virulence of the streptococcus of erysipelas is greatly increased if the organism be grown with bacillus prodigiosuSy an organism that is itself not pathogenic. Smallpox, though more than a simple suppuration, is always associated with that process and with the com- mon pus-producing bacteria.

Some bacteria produce disease by means of the poi- sons or toxins that they set free, rather than by their physical presence in the tissues. The bacilli causing diphtheria and those causing tetanus, to cite examples.

186 THE CAUSES OF DISEASE

produce soluble toxins which can be obtained in germ- free solutions and which, when injected, produce the symptoms of the diseases, even though none of the ac- tual germs are introduced.

Other bacteria, such as those of plague, typhoid, cholera, and tuberculosis, do not produce soluble toxin, unless it be that one is set free when the bodies of the bacteria are digested or disintegrated. Such bacteria are at times spoken of as forming endotoxins. The exact manner in which they cause disease is not thor- oughly understood, though recent investigations indi- cate that there are two main factors involved: (1) The bacteria, in their efforts to nourish themselves, digest and so destroy certain body cells. (2) The body cells, in their efforts to defend themselves from injury, destroy the bacteria by digesting or breaking them down, and by so doing liberate from them certain products that act as chemical poisons. The greater and more rapid the defensive digestion, so is greater and more rapid the liberation of the harmful products, and the more acute and violent are the symptoms of disease until, by practice, the cells learn to digest also the freed poison- ous products, when recovery may occur and immunity be established. In other words, the manifestations of disease may be quite as much evidences of the body's resistance to infection as of the existence of infection. Similar digestion by the body cells, rather than by the alimentary tract, of protein other than that con- tained in bacteria, such proteins, for exam- v, i" • P^^' ^^ ^o&" '^^ serum-albumen, is thought ^ ^ to account for " serum sickness " and other

manifestations of anaphylaxis.

CHAPTER X

DISEASE-CARRIERS

It has been stated in preceding chapters that diseases are oftentimes diffused by persons, animals, insects, or inanimate substances that act as carriers of the infect- ive matter or germs. It will greatly aid in the main- tenance of the health of troops if company officers and the men themselves have a proper realization of such methods of spreading disease, and the better known and more important groups of carriers will therefore be considered.

Man himself is the most important carrier of his own diseases, and most epidemics arise from the presence of one case of disease in man. Isolation and rr ,t,q„ quarantine are designed to limit or prevent p-rrpra disease-transmission in this way, and in the case of measles, scarlet fever, smallpox, and similar diseases the danger is recognized by all. It is not so generally recognized in many other common and serious diseases, such as typhoid and "colds." It is not the purpose, however, to discuss here the danger arising from contact with well-marked cases of disease, but rather to consider the unknown or unrecognized carrier. Several diseases may be widely disseminated by persons entirely ignorant of the fact that they are sources of danger. This fact has long been recognized in regard to some infections, is just receiving recognition in regard to some others, and is possibly not recognized at all in regard to still others. For several years it has been a

188 THE CAUSES OF DISEASE

matter of scientific demonstration that active and viru- lent diphtheria bacilli may linger for weeks or months, in the mouths, throats, or noses of persons who have re- covered from the disease and who appear quite healthy. It has also been demonstrated beyond dispute that some mild sore throats, " colds," and nasal discharges are due to diphtheria germs, even though the subjects do not feel particularly sick and the diseased parts do not pre- sent the appearance formerly considered characteristic of diphtheria. Other persons who have no sore throat or other evidence of disease, but who have been in con- tact with cases, as nurses or otherwise, may harbor the germs. Persons in any of these classes may ignorantly and innocently introduce the disease in new localities, transmit the germs to susceptible people, and so start epidemics. One such person in a crowded and ill-venti- lated squad-room in winter may endanger the whole command, and if, in addition he is a person addicted to careless spitting, to the use of other men's pipes, cups, or linen, the danger is greatly increased. The wise and necessary precaution in military life is to examine and reexamine all men who have had or been exposed to diphtlieria, and to keep them isolated until it has been repeatedly demonstrated that they are free from germs, and to isolate cases of sore throat as though they were all diphtheric.

The germs of cerebrospinal meningitis and infantile paralysis are also occasionally found in healthy mouths and noses, and the diseases may be transmitted by such healthy carriers. Scarlet fever often leaves an irritated throat, a nasal discharge, or a running ear, and persons who have otherwise recovered from it may transmit the infection to others and so start epidemics.

DISEASE-CARRIERS 189

Typhoid carriers constitute one of the means of ty- pTioid transmission that is now best recognized and is always considered in the investigation of an outbreak of the disease. A chronic typhoid carrier is usually a person who has had the disease and apparently recov- ered, but who continues to excrete typhoid bacilli in his feces or urine. Occasionally, however, a carrier is found who gives no history of the disease. Then, too, persons in the early stages of the disease may act as carriers and cause wide dissemination of the infection before they give up to their sickness.

The germs of cholera and dysentery may be passed by persons quite ignorant that they harbor them, and may give rise to infection through contact, water, the use of latrines from which flies may obtain the germs, and in other ways. Epidemics of bacillary dysentery or " flux " not rarely result from carelessness on the part of a carrier or a man but slightly sick. During a jail epidemic of cholera which was started by a carrier at Puri jail, in India, in 1912, thirty convalescents were examined at the time of their discharge from hospital and eleven of them found to be still excreting cholera germs. In August, 1911, six cases of cholera were ad- mitted to the quarantine hospital at Ellis Island, fifteen cases developed in quarantkie, and thirty-one carriers were detected.

As stated in the preceding chapter, man is the carrier of the commonest intestinal worms, and it is his ig- norance or carelessness that is responsible for their spread. Persons who spread tuberculosis, tonsillitis, and other troubles by their careless spitting usually do it in ignorance of the fact that they are doing wrong. Most consumptives do not realize that they have the disease

190 THE CAUSES OF DISEASE

until after they have been expectorating tubercle bacilli for some time. Other disease-carriers who may be quite ignorant of the role they are playing are sufferers from certain eye and skin diseases, such as trachoma or granu- lar lids, gonorrhoeal inflammation of the eyes^rlngworm^ itch, impetigo, and many other diseases of the skin. They may either be ignorant that they have any disease, or that the diseases they have are contagious, and so, by careless contact, the use of public towels or brushes, or those belonging to other persons, through barbers' chairs and in other ways, they may infect many persons. Nurses and doctors may at times carry and trans- mit infectious diseases, such as measles, smallpox or typhoid, either innocently, as when a diagnosis cannot yet be made and they do not know of the dangerous contact, or culpably, as when they know of the danger but do not take proper precautions to guard against it. Venereal diseases, both gonorrhoea and syphilis, may be innocently transmitted, quite aside from any ques- tion of sexual intercourse. A syphilitic infant may in- fect its nurse ; a girl may get a chancre of the lip from kissing a person who has infective lesions in the mouth and does not know it ; or possibly, though it must happen very rarely, by following a syphilitic in the use of a com- munion cup or other public drinking-vessel; doctors oc- casionally become infei^ted with syphilis through needle- pricks or slight scratches that become infected during operations. A child may contract gonorrhoea from sleep- ing with or against its infected mother, or an infant's eyes may be infected daring its birth, and others may become infected through handling it. Many men who thought themselves quite free from all venereal disease have infected their innocent wives through sexual in-

DISEASE-CARRIERS 191

tercourse, and every man who has ever had venereal disease should seek the examination and opinion of a competent physician before entering the married state.

The company officer cannot be expected to recognize the various disease-carriers in his company, but he can aid in their detection if he sees that all sick men report promptly to the surgeon, and that they remain on sick report until no longer sources of danger. Occasionally a company officer takes the unreasonable view that a man who is able to do a bit of window-washing or other light work about the hospital should be sent to his com- pany. Such action might result most seriously both to the company and the man, and the wise company com- mander will very rarely, if ever, clamor for a sick man. Even diseases not directly transmissible, such as malaria, constitute a menace in barracks, and the victims are, ordinarily, not only better off, but also less dangerous when in hospital. A man infested with worms may be capable of working and may desire to do duty, but he cannot be so well treated elsewhere as in hospital, nor will the disposal of his stools be so well looked after if he be free to go and to defecate where he pleases.

Certain diseases are derived exclusively or almost so from animals. Among them are many very dangerous infections, some of them quite incurable. Animal We will consider some of these. Carriers

Hydrophobia is a disease that affects a great many kinds of animals and is almost uniformly fatal. It is ordinarily considered a disease of the dog family, but there is some reason to believe that it is naturally a disease of certain herbivora, especially rab- bits, and the dog contracts it from these. So far as man is concerned, however, it may be considered as origi-

192 THE CAUSES OF DISEASE

Dating with the biting animals, especially the dog^ wolf ^ fox, cat, and skunk. By these it may be trans- mitted to horses, cattle, and other domestic animals, and to man himself. No cure is known for the disease after it has actually begun, but if treatment be begun soon after infection, immunity may be established be- fore the incubation period has ended, and the onset thus prevented. As there are three prevalent errors regarding this disease, each fraught with the possibility of serious consequences, they will be briefly discussed here.

The first of them is the somewhat widespread belief that the disease does not exist, that its victims really die from fright. This is abundantly disproved by the deaths of people who were not fi-ightened, who for weeks or months had forgotten the incident of the bite ; by the ability to infect and kill rabbits, dogs, and other animals, by inoculation from animals dead of rabies but not from those dying of other diseases ; by the in- fection and death of cattle, horses, and men ; by the bites of rabid animals, but of no others ; and in other ways. Hydrophobia exists.

The second error relates to the diagnosis of the dis- ease in the dog. Not every dog that slobbers and bites is rabid, and it is foolish and frequently a cause of great and needless worry to assume that he is and kill him. The disease usually begins in the dog with a change of disposition, shown commonly by restlessness and ir- ritability. The animal is easily startled and crouches in fear, or it may wander away from home. The appetite may fail, or there may be difficulty in swallowing food. Drinking is apparently less interfered with, and the name hydrophobia (fear of water) is not accurately

DISEASE-CARRIERS 193

descriptive. Even later, when, because of paralysis of the throat, the animal is wholly unable to swallow, it may still lap water with avidity, though it succeeds in doing no more than wetting its mouth. Change in the bark or absence of barking is often noted. The dog may show no tendency to violence, but pass from a state of bewilderment to aimless restlessness, characterized by a tendency to wander or to chew and swallow all sorts of unusual articles such as wood, cloth, grass, or earth, to paralysis and death. Or it may snap at things about it or at the phantoms of its disordered brain, and pass into a furious stage, that of typical madness, when it bites or tears at any thing or any animal in its way. Always the disease ends in paralysis, usually first showing in the muscles concerned in swallowing, later of the hind- quarters, the jaw, and the entire body, death coming in from four to seven days after the onset. The disease probably begins with the invasion of the dog's brain by the parasites, and the saliva is not always dangerous at the beginning. The diagnosis can be properly made only by observation of the whole course of the disease, or by examination of the animal's brain. Therefore, the correct course of procedure is either to capture the dog and confine it so that the disease may be observed, or to hill it and at once cut off its head and send that to a competent pathologist for examination.

The third error relates to treatment of bitten per- sons. It is computed that about one sixth of the persons bitten by rabid animals develop hydrophobia, the rest escaping because the saliva was not at the time infec- tious, because the clothing wiped all saliva from the biting teeth, and for other reasons. Nevertheless, the sixth that do develop the disease always die, and proper

194 THE CAUSES OF DISEASE

preventive treatment is essential. This consists in the cleansing of the wound with heat or antiseptics, the pro- motion of bleeding, proper dressing, and the Pasteur treatment for the establishment of immunity. " Mad- stones " and charms are quite useless.

Glanders is well known as a disease of horses and mules^ less so as a cause of human illness. Neverthe- less, human beings do contract it, usually with fatal results. Its contagious and fatal characters are so well recognized in the army, that its presence constitutes proper grounds for the destruction of animals, even though their usefulness is not yet greatly impaired. The persons who most often contract it are those concerned in the care and treatment of horses. As the disease in its early stages may not present characteristic or well- marked symptoms, it may be mistaken for a " cold," quinsy, or other less dangerous malady, and the animal be handled or treated without the observation of proper precautions to prevent infection. Special care should always be exercised to prevent any discharge from the nose or from sores on horses coming in contact with wounds, scratches, or the respiratory tract, and to keep the animal from blowing its nasal discharge or saliva into the face of one examining it. All suspected ani- mals should be isolated and handled as though known to be glandered until the diagnosis is settled. The disease may also be contracted from handling dead animals during their removal, or in the course of post-mortem examination, and proper precautions as to cleanliness, avoidance of wounds, and disinfection should be ob- served. Glanders and farcy are different forms of the same disease, are due to the same organism, and must be treated with equal respect.

DISEASE-CARRIERS 195

Plague or the pest is one of the most serious and im- portant diseases for which man owes a debt of hatred and warfare to his animal neighbors. It has not as yet gained an extensive footing in our country, but it took San Francisco some years to get rid of it ; at this writ- ing New Orleans is struggling to do so, while the Pan- ama Canal is menaced from Colombia, Peru, Chili, Cuba, and other points; and it is only by unremitting care that we can hope to prevent its spread there and at home. Starting in southern China some twenty years ago, it has since invaded each of the continents and many of the islands of the seas, while its toll has been millions of lives and vast treasure. As lately as 1911 it caused 842,000 deaths in India, and 273,000 in 1912, 199,000 in 1913, and 178,000 in the first six months of 1914, in spite of the active campaign that has been waged against it there for almost two decades.

The investigations of the British commission ap- pointed to study the disease in India show clearly that epidemics of human plague arise after and in conse- quence of epizootics of rat plague. 'The infection is transmitted from rats to man by fleas, usually those of the rat, and the relation of the epidemics to the epizootic is beautifully shown as follows : There are two principal species of rat concerned there, the brown or Norway rat and the black or house rat, the former also known as the ship and the sewer rat. It is among that class that the epizootic arises, usually, and in about 7.2 days later it is also prevailing among the house rats. This 7.2 days is accounted for by tlie fact that it is also the average experimental time elapsing be- tween the biting of the black rat by an infected flea and the death of the animal. (The rise of the epizootic

196 THE CAUSES OF DISEASE

is measured by the numbers of rats found dead or dy- ing.) The black rat epizootic precedes the height of the human epidemic by from ten to fourteen days, a period accounted for as follows : The rat flea does not readily attack man until starved for three days. The incubation period of human plague is about three days. The dura- tion of the fatal human plague averages four and a half days. Average total, eleven and a half days.

The relationship between rats and human plague is also proved in other ways, but they cannot be discussed here. The fact is established, and it constitutes the most important of the many reasons why man should be at enmity with, and try to exterminate, rats.

It must be borne in mind, however, that other ani- mals may be infected, and wild squirrels have been shown to have the disease in California. They and gophers, prairie dogs, and similar animals may yet play an important part in disseminating it. While dirt and unsanitary conditions cannot give rise to plague, their influence in promoting the presence and increase of both fleas and rats is so well recognized that it is well to mention the matter as showing how they may strongly predispose to disease that they cannot cause directly.

The great Manchurian epidemic of pneumonic plague in 1910 has been thought to have originated among trappers of plague - infected rodents, but, however started, that epidemic was not spread in the ordinary manner. It spread with tremendous rapidity and killed nearly all whom it infected. Transmission was by drop- let infection and inhalation, the germs entered by the respiratory tract and caused pneumonia, and in the few months of its raging the disease caused thousands of

DISEASE-CARRIERS 197

deaths. However, the conditions favoring a similar spread exist in few places. During the summer myriads of Chinese go north to work in Manchuria. In winter they return, and the writer has seen train-loads of them riding all day in open coal cars, in windy weather when the temperature was below zero, and at night stopping at such places as Mukden and being packed into close and dirty inns as they were packed in the cars in day- time. It requires no vivid imagining to understand how pneumonic plague would spread like wild-fire when introduced among men so environed. So we see that even diseases that are ordinarily insect-borne may at times find man himself their most favored carrier.

Tuberculosis is the most prevalent disease affecting man, and is responsible for more deaths than any other one cause. It is also a common disease of cattle and of some other animals, and it may be transmitted to man from them. Tuberculous meat, if not sufficiently cooked to sterilize it, may be the medium of infection, but milk is probably even more commonly the carrying agent. A cow that has tuberculous disease of the udder may give off immense numbers of bacilli, and these may be in- gested in a virulent condition in milk, cream, butter, or cheese. This method of infection is so common that some authorities who have devoted great study to the subject contend that it is the usual, if not the exclusive method, and they relegate infection by inhalation to a place of very minor importance. Such a view is extreme and probably not correct, as shown, for instance, by the fact that tuberculosis is very prevalent in Japan and other far eastern countries where neither milk nor beef is a common article of food. Nevertheless, infection by means of these food-articles can and does occur, and the

198 THE CAUSES OF DISEASE

precautions against the sale of tuberculous meat and milk are wise and salutary. Observations made in New York and elsewhere on the type of bacilli found in series of cases of tuberculosis of children indicate that about seven per cent of the cases were caused by bacilli of the " bovine type." Wild or range cattle are much less subject to the disease than high-bred, stabled cattle, and many other animals that suffer from it in captivity are free from it in their native wild state, thus showing the predisposing influence of confinement and crowding.

Tuberculosis is rather common also in pigs, dogs, and cats, less so in sheep and goats. The disease may be transmitted by the flesh of pigs. Pet animals, such as dogs and cats, are apt to contract and spread the infec- tion because of their habits of licking up sputum and other discharges to which they may have access. This furnishes another argument for the proper care and destruction of all tuberculous discharges. The urine and fecal discharges of men or animals that have tubercu- losis may contain the bacilli and may constitute serious dangers. Thus a cow that is passing the germs in these ways may indirectly infect sound cattle or their milk by means of bacilli blown about the stable with the dust of dried feces or urine, or by soiling the pasturage.

Fish and birds also have tuberculosis, but it is doubt- ful if the forms of it that they have can be transferred to man. It is not, however, necessary to go to the ex- treme lengths that fear may carry one in the efforts to avoid tuberculosis. Patients with the disease need to be taught to take proper precautions as to the disposal of their spit and other excreta, but when they take such precautions they need not be avoided. In fact, among investigators of tuberculosis there is a growing and

DISEASE-CARRIERS 199

pretty widely accepted belief that practically all per- sons become infected with the disease early in life, and that the large majority overcome it. Its appearance in later life is then credited to a lowering of general bodily resistance, rather than to a recent infection. This ac- counts for the " predisposing " influence of typhoid and measles, they lower the resistance to an infection that already exists. Tuberculous milk is best avoided, but if the milk is not known to be infected, but is merely of unknown or doubtful origin, it can be rendered safe by boiling or pasteurization. The indiscriminate sale of tuberculous meat is properly forbidden by law ; but if an animal is not badly diseased and the visibly injured portions of the carcass are rejected, the rest can be eaten with safety if it is first properly cooked. Such meat is not purchased for the army, however, and the above statement is made for its general worth and not to en- courage the acceptance of inferior stores.

Anthrax is a disease that causes a very great number of deaths in cattle and sheep in various parts of the world. Other animals are also susceptible to it in vary- ing degrees, among them being horses, deer, pigs, mice, and rabbits. Man suffers from it in two or three forms, generally obtaining his infection from the hides of ani- mals dying of it. Wool-sorters and hide-handlers are therefore particularly subject to it, and one common name of the trouble is " wool-sorters' disease." Soldiers have also been known to be infected (though not in our army) through the use of sheepskin-lined coats, or boots made of poorly cured leather. The disease is often fatal, and materials from animals dead of it should not be used. It is caused by one of the spore-forming bacilli, and the spores are very resistant to both heat and

200 THE CAUSES OF DISEASE

chemicals. Human infection takes place in two ways : through cuts or abrasions brought into contact with in- fected skins, carcasses, or other matters, and by inhala- tion of hairs, bits of wool, or dust that carry the spores.

It has been definitely shown that several species of African antelope are capable of infection with the tryp- anosomes of human sleeping sickness, that tsetse flies may become infected by feeding on them and may trans- mit the disease, and that the antelope in question are at least " potential reservoirs " of the disease and probably actual ones. There is still warm discussion as to whether the government should enter upon a policy of game extermination, the opposition being based upon what is considered insufficiency of proof of the actual impor- tance of such reservoirs.

Man is the occasional subject of some other diseases of animals, and it is a good general rule to take as much care to prevent infection from a sick animal as from a sick person, unless the disease is known to be one, such as rinderpest, to which persons are not liable.

Domestic animals are also occasional carriers of com- mon human diseases. Dogs and cats have been known to have diphtheria. Cats have been experimentally in- fected with whooping-cough, and there is reason to suspect that either of these animals might carry the contagium of such diseases as smallpox, scarlet fever, or measles in its hair. The liability of getting ring- worms and other skin diseases, as well as lice and fleas, from domestic animals has already been mentioned.

Insects of different kinds transmit diseases in various ways. The first and simplest way is by acting as simple carriers. Thus germs become attached to the legs and bodies of flies alighting on an infected wound or a yaws

DISEASE-CARRIERS 201

papule, and these by later alighting on clean wounds or abrasions may leave the germs there and _ cause infection. Or the transfer may be -« less direct, as in the case of the fly that goes from a typhoid stool to a food-article and there leaves germs to be later ingested with the food. In other instances the simple deposit of the germs may not insure infection, but the irritation caused by the insects may further it. This is well shown in the case of plague. The flea transmitting that disease may do so by reason of the fact that the germs are adhering to its mouth-parts and are introduced directly by the biting act or, as has recently been shown, the germs imbibed at a previous feed may have so multiplied in the flea's stomach as to obstruct the opening into it, with the re- sult that when the insect attempts to feed again the pumping motions that it makes simply draw the blood into the oesophagus, whence, laden with plague bacilli, it flows back into the wound. On the other hand, the mouth and external parts of the flea may be free from germs, in which case infection may occur as follows : The flea has a habit of defecating while it sucks blood, probably to make room for a larger meal, and in so doing it may deposit plague-germs on the skin, near but not in the wound. If, now, the bite is rubbed or scratched, as is often the case, the germs may in that way get into the wound and infection be assured. An insect trans- mitting the disease in this last described manner is called a contaminative carrier, and there are some diseases, as relapsing fever carried by body lice, in which that and the rubbing in of the contents of crushed lice, seem to be the only methods of infection, the bite alone being harmless.

202 THE CAUSES OF DISEASE

More complicated processes are involved in other in- stances, as in malaria, yellow fever, or filariasis, in which the parasites must undergo a cycle of development in the insect ; and the latter cannot transmit the disease until a sufficient time has elapsed to allow that to occur. Some insects can transmit germs, and the capacity to convey infection to man or other animals, to their offspring. This fact has long been known regarding the tick that transmits Texas fever to cattle, and it has more recently been proven true as to those infecting man with the spotted or tick fever of Montana and the relapsing or tick fever of Africa. These diseases may be transmitted by the bites of ticks raised from the eggs of those biting infected persons, but which have not themselves ever bitten people or had any other chance than through heredity to obtain the infection. The body louse can transmit the cause and power to infect with European relapsing fever to its offspring, and the same sort of thing maybe true as to some other insects and diseases. Among proved or probable insect-carriers of general diseases are Jliis of various kinds, several species of mosquitoes^ sand-flies of some varieties, the harhiero of Brazil, ^eas, lice, bedbugs, ticks, mites, and roaches.^

Among inanimate carriers of disease, food, water, and milk have already been men'ion'id several times.

^ A most cnriona and interesting example of an insect actings as a carrier for another insect has recently been worked out partially in Central and South America. A large fly, Dermatobia cyaniventris, the size of the ordinary bluebottle fly, manages in some manner as yet un- known to get its eggs stuck to the side of the thorax of a variety of mos- quito, Janthinosoma ItUzi. When the eggs hatch the larvae enter the skin of a man through the wound made by the bite of the mosquito, and there develop, causing abscesses or boils.

DISEASE-CARRIERS 203

They may serve as the conveying media for practically all infections that can occur through the - alimentary canal, including such important _, ones as tuberculosis, typhoid, cholera, dys- entery, diphtheria, scarlet fever, and many others. These articles, and milk especially, offer such opportu- nities for the multiplication of bacteria that they may convey to the consumer many thousand times as many germs as originally had entrance to them. Thus a can of milk, becoming infected with a few hundred typhoid bacilli from the hands of a farmer-carrier, may, when consumed in a city, ten or twelve hours later, have billions of germs in it, and cause a great many cases of the disease. It is, therefore, important to prevent the access of even one disease-germ to such articles, and carelessness in their handling should not be con- doned. Fortunately, thorough cooking will destroy dis- ease-germs in all of these substances.

Clothing, books, carpets, toys, and other personal and household belongings that have been handled or used by persons ill with such diseases as smallpox, measles, scarlet fever, and diphtheria may serve to convey infec- tion for varying periods of time, periods fortunately not usually very long, and for that reason the disinfection or destruction of such articles is resorted to as a means of preventing the spread of contagion. Such articles as can be boiled or thoroughly steamed can be quite well disinfected, but if facilities are not at hand for steriliz- ing such large articles as mattresses, they may need to be destroyed. Boots, hats, and certain other classes of articles will not stand steaming and may have to be disinfected with chemicals or destroyed, though in most instances exposure of them to the sun and fresh air for

204 THE CAUSES OF DISEASE

some days would render them safe. In fact, there has accumulated a mass of evidence to show that terminal disinfection of houses and of inanimate things in gen- eral is much less important in the suppression of infec- tious disease than was formerly thought to be the case, though prompt disinfection of things used during the actual sickness, such as spoons, bedding, and utensils, is thought as important as ever.

Such articles of personal belongings are also common carriers of the organisms of suppuration. So widespread are such germs that almost everything in common use has them on it ; and if brought into contact with a wound they will leave the article and start infection. This alone makes the sterilized and sealed first • aid packet of so much greater value than articles of cloth- ing and handkerchiefs as first dressings for wounds. The packets, if not contaminated by handling, practi- cally never cause infection ; the other articles almost always do so. Nails, bullets, knives, and other missiles or weapons that have not been sterilized may infect the wounds they cause ; or, if sterile themselves, may carry infection from the skin or clothing they traverse.

PART III

THE PREVENTION AND CONTROL OF EPIDEMICS

•' Thou sTiaU not he afraid . . . for the pestilence that toalketh in darkness : nor for the destruction that wasteth at noonday."

Psalm 91 : 56

CHAPTER XI

THE DEFENSES AGAINST DISEASE IN GENERAL

Fortunately for the human race, the contracting and development of disease are somewhat difficult mat- ters, and only follow the occurrence of certain trains of circumstances. They may be compared with the de- feat of an army, for which purpose it is necessary that the army become weakened by loss of men, hard marching, lack of food, exposure, or some other cause ; or that the enemy has been able to bring a superior force on the field, that his supplies are better or are more promptly delivered ; that one side improves its opportunities for offense or defense and the other does not ; or that other good and sufficient reasons are pre- sent. The mere existence or contact of two armies does not explain that a certain one of them is defeated. So in the matter of sickness, the mere existence or contact of a man and typhoid organisms is not in itself suffi- cient to insure that the man has or will get typhoid fever. For that purpose it is necessary that the germs shall be alive, virulent, and capable of development, that they shall gain entrance to the body of the man in sufficient numbers, that the man's body shall be unable to destroy them before they have time to de- velop and liberate their poisons, and that his tissues shall unite with such poisons after they are liberated. It is relatively rare that these conditions coexist, and typhoid fever is therefore not more common than it is. Our defense against sickness then rests on our ability

208 THE PREVENTION OF EPIDEMICS

to break or destroy the chain of disease-favoriug cir- cumstances. If we can entirely destroy it, we are sure to remain well, but if we cannot do that, the destruction of one link may save us. It is well, therefore, that we should first consider general plans of defense or aggres- sion, and later pass to the discussion of special cam- paigns or battles.

The body is defended from disease by many natural factors, and we should try to preserve these intact. The

skin presents an impassable barrier to most

Natural . a c • * *•

^ , organisms, and very tew infections can

C6Z6I1S6S .

enter through it as long as it remains un- broken. It has weak points, however, and ^ infections may occur in the hair-follicles

or in the skiu-glands. Boils are the commonest results of such invasions. The organisms of typhoid, tubercu- losis, and many other diseases could be put on the sound skin with impunity, if they did not later gain entrance to the nose, mouth, wounds, or other openings.

The mucous membranes are all warm and moist, and, in that way, offer favorable conditions for bacterial growth ; but they are all covered with mucus to which the germs may adhere, and with which they may be passed out of the body by spitting or otherwise. The cells lining some mucous surfaces have little, moving, hair-like projections, and by means of these are able to pass along and expel small foreign bodies getting on them.

The gastric juice is sufficiently acid to destroy many varieties of micro-organisms, and digestive disturbances that lessen that acidity increase the liability to infec- tion. The fluid also has the power of neutralizing or digesting some poisonous products, but not all.

DEFENSES AGAINST DISEASE 209

The urine, by its acidity and its irrigating and cleansing action, doubtless has an effect in keeping down the number of cases of venereal diseases.

The prompt reaction to in'itation is often a disease- preventing factor. A dose of arsenic or a meal of tainted meat may produce such prompt vomiting as to cause the expulsion of all poison, and so prevent further symp- toms. The inflammatory reaction following the infection of wounds is usually a conservative process that limits the infection to the locality of the wound, and prevents its diffusion through the body.

As stated before, however, a man may possess an immunity to certain diseases even though the germs gain entrance to his body in the numbers Tjj.jj.„. and of the virulence ordinarily producing „■*_. such diseases. This may be hereditary or ^^?iatnral" immunity, when the man is born without susceptibility to the disease. It is acquired when due to something occurring after birth. Acquired immunity is usually due to an attack of the disease, and is well recognized in such affections as smallpox, measles, scar- latina, and typhoid. It is common knowledge that one attack of any of these usually protects against a second. This is also known as active immunity, because the body is active in maintaining it. Passive immunity is due to the introduction into the body of ready-made im- munizing substances, such as diphtheria antitoxin, that is contained in the blood-serum of an immunized horse. Active acquired immunity may also be induced by vaccination, the procedure whereby disease-producing organisms in an attenuated or weakened state are intro- duced into the body and set up a very mild form of disease, but one sufficient to set the body on the de-

210 THE PREVENTION OF EPIDEMICS

fensive and cause it to produce inamunizing substancee. This procedure is best known in its relation to small- pox, and as that was the disease for whose prevention it was first used, the name vaccination in the broad sense, that is, the introduction of disease-producing germs to produce immunity, is taken from that instance. It has also been used, though, to produce immunity to cholera, plague, dysentery, typhoid fever, hydrophobia, and sev- eral diseases of animals, in some instances with consid- erable success.

Immunity may also be relative or absolute, temporary or permanent. Man's lack of susceptibility to the pleuro-pneumonia of cattle, for instance, is hoth perma- nent and absolute. An attack of smallpox may produce an immunity that is either 2)ei'manent or temporary. In the latter instance the sufferer might have a second attack after some years. A relative immunity to typhoid might protect against a small number of bacteria, but not against a very large number. Relative immunity partially protects races long resident in malarious re- gions from the more severe or urgent manifestations of that disease. This particular form of it is probably partly acquired as the result of the prolonged exercise by the body of its resisting powers, and partly inherited and due to the survival of the more resistant individu- als and the transmission to their progeny of their re- sistant qualities. In most highly malarious regions the natives are practically all infected, yet they appear to be in fair health, but foreigners going among them are apt to be attacked by malaria in its most severe and dangerous forms.

Immunity is due to several factors, not all of which are understood. In regard to some diseases, such as

DEFENSES AGAINST DISEASE 211

diphtheria and tetanus, it is due to the development of antitoxin, a substance that acts as a direct antidote to the poison of the disease and neutralizes its effects. In other instances, as in the case of plague, cholera, and typhoid, it is largely due to the presence or develop- ment of substances that kill or dissolve the bacteria. It is probable that it is often due to the ability of the tissues to digest thoroughly the protein of the bacterial bodies and render it harmless, as discussed on the last page of chapter ix. In many instances it is partly or entirely due to the activity of certain cells, phagocytes, that take up and destroy the germs. Absolute hereditary immunity may be due to none of these, but to lack on the part of the body cells of chemical groups that enable the poisons to enter into combination with them.

Ilelative immunity is maintained by those conditions that keep up the general health and maintain the re- sistance of the body. It is lowered by causes -, - that depress these, such as starvation, ex- __ - , haustion, injuries, shocks, worry, and grief. It is therefore important that the man and his environ- ment be constantly kept at their best, that abundant and proper food, pure water, good air, and right clothing be provided, that sufficient exercise to keep the respira- tion, circulation, digestion, and excretion active be taken; that overwork, improper food, alcoholic and venereal excesses, and the entire list of things predis- posing to disease be avoided.

All of these measures tend to strengthen the man and put him in good condition and position for the combat with disease ; and, as with armies, so in this in- stance, the maintenance and strengthening of our own forces is not less important than the weakening or bin-

212 THE PREVENTION OF EPIDEMICS

dering of the enemy ; and as the possession of a large and well-trained army is, in these days, often spoken of as a "national insurance policy" and a guarantee of peace, so may the well-trained and sound body be re- garded as insurance against disease. As the combat with germs is, however, one that never ceases, we must also try to injure the enemy as much as possible, giving no quarter, as we may expect none. We should try to eradicate all disease-producing organisms, to reduce their numbers where we cannot do that, and to weaken them by every means available. Many of the measures designed to accomplish these ends have been mentioned or discussed in preceding chapters or will be taken up more fully in later ones, but some of them may be con- sidered at length here and not again described. They may be classed in two categories : measures designed to prevent contact with the germs, and those aimed at their destruction.

Among the former, avoidance of the sick may be considered one of the most important measures. This recommendation cannot be taken as coun- tenancing neglect of the sick or lack of all ance of i • ^ • r

e- 1- proper care and attention, but it refers to

unnecessary contact with them, that due to carelessness, curiosity, or sentimentality. As stated before, the principal agent in the dissemination of human diseases is man himself, and nearly every case of infectious disease is derived from another. Therefore, unnecessary visits to hospitals and sick-rooms should be discouraged, and in military life it should be axiomatic that sick men should be removed from squad-rooms, un- less good reasons to the contrary exist in special cases. Even though the sick man goes into a general ward

DEFENSES AGAINST DISEASE 213

in the hospital, he is less apt to infect others there for several reasons. One of these is that air- __ ^. space and ventilation are more liberal there. ^ In the squad-room, where but six hundred cubic feet of space are allowed each person, a sick man may seriously contaminate the air. In hospital the same amount of contagium is dilated two to four times, be- cause the space per man is twelve to twenty-four hun- dred cubic feet. Naturally an exposed person breathes in only one third as many organisms. Precautions are also taken in hospital to reduce the chances of mediate contact.

In the more readily transmissible diseases isolation is resorted to as a means of insuring lack of contact. For

this reason it is highly important in such , ,

LL J. ^ • li T 11 1 . Isolation

"catching diseases as smallpox, scarlet

fever, and measles, and is of value in the management of typhoid and most other infectious diseases. Both the character and the duration of the isolation vary in dif- ferent diseases, according to the methods and ease of transmission and the duration of the infectious period. Typhoid and many other infections can be safely iso- lated in a room or even in a general ward, if proper care is taken in the disposal of excreta, bath-water, and other waste material, in the exclusion of flies and ver- min, and in the prevention of mediate contact and the prompt and careful disinfection of the means of such contact, such as bedding, utensils, thermometers, unused foods, nurses' hands, etc. Such care may be necessary for weeks or months. It is usually considered necessary to isolate smallpox cases in a separate house or tent, removed from other houses, and to continue the isola- tion until the patient is well. The contagion of measles

214 THE PREVENTION OF EPIDEMICS

is so readily transmissible that isolation would seem very important, but the period of contagiousness comes so early in the disease that isolation is not effective, be- cause it is not applied soon enough. In yellow fever, malaria, and dengue the degree of isolation is not neces- sarily greater than that afforded by the screening re- quired to exclude mosquitoes from the sick, while in typhus and European relapsing fever, both formerly considered so highly contagious, it is only necessary to keep lice from the patient and his visitors.

Infectious diseases of various kinds have different incubation periods. These represent the time elapsing -^ between the occurrence of infection, the

^ entrance of the germs into the body, and

the appearance of the disease. In some cases of cholera, diphtheria, and a few other diseases, the in- cubation period may be as short as one day or a few hours ; while in hydrophobia it may extend many weeks and possibly months. Diseases also vary as to length of time during which the subjects remain sources of danger after their apparent recovery. Yellow fever, for instance, ceases to be dangerous, to others than the patient, after the third day of its existence ; while a typhoid patient may continue to give off immense num- bers of virulent organisms and constitute a source of danger to the community for many years.

The term quarantine, though used in several senses, the oldest meaning a forty-day period of isolation for persons thought to be possible subjects of disease, is now most commonly used to indicate the separation from the general community of persons presumably exposed to infectious disease, and observation of them during the period of incubation of the disease in question. In

DEFENSES AGAINST DISEASE 215

practice the term is also used to cover the isolation of the sick. Employed rationally and under sound medi- cal advice, quarantine is often a valuable measure and may prevent epidemics. It is one of our main reliances in excluding plague, cholera, and many other diseases from our ports.

But it is always attended with hardship to its sub- jects, and when controlled by laymen actuated by panic, fear, or malice, it may become an instrument of cruelty and oppression. Only trained medical officers should direct or control systems of quarantine, and their training should be relied upon to suit the system to the circumstances. A fixed isolation period, say of one month, for yellow fever and scarlet fever, would be wrong in both instances, but in the one the patient would be unjustly treated, in the other, the public.

In addition to the matters of barrack, camp, and kitchen police already discussed, larger schemes of po- licing or engineering are important in the p-j^^- prevention of disease. These embrace such , _

diverse measures as the construction of fil- ^.„^^ .^^ , - p . 1 gmeenng

termg plants and water-systems to furnish Trr-Qj-tg

an abundance of pure water, the installation of sewerage-systems and crematories for the removal or destruction of waste, thorough policing and cleaning of streets and neighborhoods to keep down dust or reduce vermin, or the draining, filling, or oiling of marshes to do away with mosquitoes.

The best known and most commonly employed mea- sures for killing germs are usually spoken of as disin- fection and sterilization. The terms are not synony- mous, though often used as if they were. When an article is sterile in thp bacteriological sense, it is free

216 THE PREVENTION OF EPIDEMICS

from all germs. Disinfection may free it from all

_.. . , germs, but does not necessarily do so. It

, means the destruction of infectious organ-

g, ... isms. A urinal or bedpan contaminated

^ by use by a typhoid patient might be dis-

infected by simply rinsing in hot water, as the typhoid germs are killed in a few minutes by a tem- perature of 70° C. It would certainly not be sterile.

Heat is the most reliable of the means of sterilization of small inanimate objects. It may be applied moist or dry, the former effective at much lower degrees than the latter. Boiling water or streaming steam, both of which have a temperature of 100 C, will destroy all kinds of growing germs in a short time, while dry heat of 200° C. is necessary to accomplish the same purpose. As this temperature will burn fabrics and is dangerous, it is not much used. Boiling is simple and is easily ap- plied to small articles, so that it is commonly resorted to where special appliances are not available. In hos- pitals steam sterilization is more often resorted to, as being more convenient and not necessitating so much handling and drying of articles. Large institutions also have steam-chests of sufficient size to receive such bulky articles as mattresses, carpets, and other household fur- nishings, which may thus be quickly and thoroughly disinfected. Gases and solutions of chemicals are also used for disinfecting ; the former for rooms, furnishings, or clothing that would be injured by heat, and to pene- trate into cracks and crevices not otherwise accessible. As many of these substances possess disagreeable odors, or have the property of destroying smells, the lay public at times displays a tendency to confuse deodoriza- tion and fumigation with disinfection. The three may

DEFENSES AGAINST DISEASE 217

coexist, but they are not the same, and the words should not be used loosely, as such usage may lead to confusion of the processes and so do harm. Charcoal is a good deodorant, and burning tobacco or pyrethrum may furnish efficient fumigation in ridding a house of mos- quitoes, but none of these is disinfectant. The principal gaseous disinfectants are chlorine, sulphur fumes, and formaldehyde. All of them are very irritant and un- suitable for use in efficient concentration in rooms or places where they will be inhaled.

Chlorine is not commonly used in its gaseous state, and when "chloride of lime" is sprinkled about it is liberated in such small amoumts as to be inefficient. In watery solution it is valuable in disinfecting surfaces to which it can be applied. It is a powerful bleaching agent, and cannot be used on fabrics. Of recent years this substance has come into very wide use as a purifier of water. Many cities use it, and its use by troops in the field has already been discussed.

Burning sulphur gives off fumes which unite with water to form sulphurous acid, a very efficient disin- fectant. The dry fumes have very little virtue of the kind, but are very useful in destroying vermin, such as flies, mosquitoes, and rats. When it is desired, however, to disinfect a room that has been occupied by a case of contagious disease, such as scarlet fever, by means of sulphurous fumes, the walls, floors, and other surfaces should first be moistened by wiping them with a damp rag, or in some other way. As sidphurous acid also bleaches or fades fabrics, it is frequently not to be used except at great expense.

Formaldehyde gas, or its forty per cent solution in water, known as formal or formalin, is now more often

218 THE PREVENTION OF EPIDEMICS

used than any other gaseous disinfectant. The gas may be generated in the room to be disinfected by burning wood alcohol in special burners known as formaldehyde generators, or it may be liberated by the evaporation of formalin. The latter is a very simple procedure, and while its effectiveness cannot be guaranteed, the same may be said of other gaseous disinfection, and it is often the best available means. Many methods of for- maldehyde disinfection have been used, but only the use of formalin will be described here. For disinfecting the contents of trunks and boxes, it may be sprinkled over them freely, or placed on absorbent cotton or blotting- paper and the boxes then closed tightly for twenty- four hours. For the disinfection of rooms, from four ounces to a pint of formalin should be used for each thousand feet of cubic contents. The gas is speedily liberated if six ounces of permanganate of potash be added to the pint of formalin in a large bowl, or if unslaked lime be added, or if the fluid be poured on hot bricks. A still simpler and quite efficient method, however, is to close hermetically all cracks and crevices about the room, stretch ropes or strings across it and on them hang sheets. The formalin is then poured upon the sheets to saturate them, and the room tightly closed and kept so for twenty-four hours or more, after which it should be well opened and aired, to rid it of all fumes. None of the gaseous disinfectants can be depended upon to penetrate thoroughly into large and thick arti- cles such as mattresses. Their action is apt to be super- ficial, and it is therefore important that the articles in a room to be disinfected be disposed in such a manner as to expose as much surface as possible. Bedding should be taken out of piles and hung on ropes or racks, pic-

DEFENSES AGAINST DISEASE 219

tures removed from walls, books opened so as to expose all pages if possible, pockets turned inside out, and all boxes opened.

Formaldehyde is less harmful to fabrics and colors than the other gaseous disinfectants, and is altogether the most satisfactory for ordinary use, except that it cannot be depended upon to kill insects and vermin.

Fluid and solid chemicals, the latter in solution, are much used as germicides^ disinfectants^ or antiseptics. The number of substances so used is large, some of the more important of them being the various acids, per- manganate of potash, peroxide of hydrogen, and those to be discussed.

Bichloride of mercury, or corrosive sublimate, is probably the most important, and for many purposes the most valuable, antiseptic drug. It is used in watery solution of various strengths. A solution as weak as one part in one million has some value, but it is gener- ally used in strengths varying from one part in five hun- dred to one in five thousand, and in such dilution is a very powerful antiseptic, killing most germs in a few minutes. It has attained popularity, and is commonly sold in tablets of such size that one added to a pint of water makes a one to one thousand solution. The main objections to bichloride are that it is a powerful and deadly poison, and the tablets in which it is sold may, by mistake, be taken for other substances ; and that it corrodes and injures metals with which it may come in contact. It works more efficiently when combined with an acid, and the tablets are usually such combinations.

Carbolic acid, or phenol, is quite as well, if not better, known as an antiseptic. It is not so powerful as bichlo- ride, and is used in solution of from one to five per cent

220 THE PREVENTION OF EPIDEMICS

strength. Occasionally it is used in what is called its " pure " form, about ninety-five per cent strength. It is a very deadly poison, but it does not corrode metals as does bichloride, and is therefore better for disinfecting them. Both of these substances irritate and injure the bands if much used.

Iodine has long been known as an efficient disin- fectant and antiseptic, but it has grown in favor very rapidly in the last few years and is now particularly esteemed for use in disinfecting the skin or the sur- faces of wounds, for which purpose the tincture is gen- erally used.

" TrikresoV^ is a disinfectant that is supplied and much used in our military service. It is less readily sol- uble than phenol, but is equally as powerful a disin- fectant when used in half the strength of the solution of the latter. It also is a poison.

There are numbers of mixtures or emulsions made with cresols or crude carbolic as bases, which are both cheap and excellent for many purposes. Many of them, like the Creolin issued among veterinary supplies, are proprietary preparations and are sold under trade names. As cheap, efficient, and not secret in composi- tion may be mentioned the official compound cresol so- lution and the " larvacide " used on the Panama Canal to destroy mosquito larvae and as a disinfectant.

Formalin is also used as a liquid disinfectant, and for some purposes, such as the disinfection of urine and feces, it is probably the most valuable one we have. It should be thoroughly mixed with a stool to be dis- infected, lumps of feces broken up, and the two allowed to stand in contact for a time. Formalin is also a val- uable deodorizer.

DEFENSES AGAINST DISEASE 221

For a few diseases we have remedies that may be termed specific, or truly curative. In most infectious diseases, however, we are at best able to modify the course of the affection, to re-

ClUGS

lieve symptoms and maintain the strength and vitality until nature, or the body forces, accom- plishes a cure ; and even the specifics cannot always be «:iven in such a way that they get at and destroy all the organisms of disease.

Quinine is a specific for malaria, and actually de- stroys the growing and multiplying organisms in the blood. Yet men occasionally die of malaria in spite of quinine, and many hundreds of army men can testify that quinine does not always effect a prompt and per- manent cure of the disease.

Mercury is a specific for syphilis. It kills the organ- isms causing the disease, and causes the lesions to heal; yet the men who have devoted the most attention and study to the subject agree that treatment must be con- tinued from two to four years in order to assure a cure.

The drug kuown as " salvarsan " or " 606^'^ which was introduced a few years ago as a specific for syph- ilis, is actually such, and it destroys the causative or- ganisms with great rapidity. However, it is apparently unable to reach them all, and world-wide use of it, while proving its value, has only destroyed the hope at one time cherished, that one injection could be depended upon to cure the disease.

Antitoxin is a specific for diphtheria, neutralizing the poison and making it harmless. Yet, if it be not given early and the toxin has a chance to unite with the tissues, it may fail, and death result in spite of its use.

Altogether, the consideration of specific remedies

222 THE PREVENTION OF EPIDEMICS

cannot but convince us that the prevention of disease is of much more importance and value than its treat- ment, and that the tendency, often manifested, to regard the medical officer as one whose main office is the treat- ment of men already sick, one who should have nothing to do with the general administration of a post or an army, is a very grave mistake. Specifics are very valu- able, however, in the prevention of disease. Mosquitoes are not apt to obtain infection from the blood of men taking quinine. The man who is under treatment for syphilis is less apt to transmit it than the infected man who is untreated, and the prompt use of mercurial inunctions after intercourse has been shown to be of value in the prevention of infection. " Fourth of July " tetanus, at one time all too common, was very greatly reduced by the routine use of tetanus antitoxin after injuries caused by fireworks.

CHAPTER XII

DISEASES DUE TO INFECTION THROUGH THE ALIMENTARY TRACT

Typhoid and para-typhoid fevers, cholera, dysentery, and " camp diarrhcea," which is apt to be typhoid or dysentery, may be conveyed in other ways than are in- dicated by the heading of this chapter. Typhoid, for instance, may be produced by injection of the living organisms beneath the skin. In general, though, these diseases come from the ingestion of the causative or- ganisms by way of the alimentary canal. The germs are in the vast majority of instances introduced in or on food or drink. For many years water was considered the principal medium for the introduction, and it is still recognized as a very important factor. Of late years, however, so many cases, and even large epidemics, have been traced to infected foods and so many more to con- tact that it is really considered misleading to speak of these merely as " water-borne " diseases.

In addition to the acute infections mentioned above, there are a number of others that enter by the same route. Tuberculosis does so at times, possibly in a large proportion of cases ; many " acute food poisonings " are properly alimentary tract infections ; " milk sickness '* is due to infection with germs contained in milk from diseased cows ; Malta fever to germs in the milk of goats infected with that disease ; infestations with many varieties of intestinal worms occur by way of the mouth, and some of the diseases to be later described as enter-

224 THE PREVENTION OF EPIDEMICS

ing by way of the respiratory tract, such as diphthei'ia, are known to be carried in infected milk. It is conceiv- able, though doubtless uncommon, that typhoid or chol- era organisms may enter the body through inhalation, and in the throat pass to the alimentary tract and be swallowed. In fact the throat, where diphtheria, scarlet fever, and a number of other infections are apt to local- ize, is common to both the alimentary and the respira- tory tracts, and it is not always possible to say by which tract an infection enters. However, it is generally cor- rect to speak of the diseases here discussed as entering by the alimentary tract, and it has been found in prac- tice that the other avenues may be neglected without great danger.

These have always constituted a very important group of diseases, particularly for military men, and in ancient and modern times, an<l in all of our wars, clear down to and including the war with Spain and the later Phil- ippine insurrection, typhoid and dysentery did more damage than did hostile arms. As our knowledge in re- gard to them has grown and we have learned of their causes and the subtle and manifold methods of trans- mission, we have been more and more able to avoid them, and if they ever again cause such morbidity as they have in the past, it will be because of neglect or of cir- cumstances beyond control, and not because of igno- rance. As showing how great a scourge typhoid has been to us even in recent years, and after the method of water carriage of the disease was well understood, may be quoted the official, and it is thought conserva- tive, statement that " About one fifth of the soldiers in the national encampments in the United States in 1898 developed typhoid fever. Among 107,973 officers and

ALIMENTARY TRACT INFECTION 225

men in 92 regiments, the records of which we have care- fully studied, the number of cases of typhoid fever, according to our estimates, was 20,738." The above is from the report of the " Board on the Origin and Spread of Typhoid Fever in United States Military Camps during the Spanish War of 1898," of which board the late Major Walter Reed was president. That report gave an impetus to the investigations that have since so greatly increased our knowledge of the disease and of the means of preventing it as to give rise to the lively hope that such conditions as the board investi- gated may never recur. Nevertheless cholera, which is equally well understood and preventable, did great damage to troops so recently as the late war in the Balkans.

Typhoid fever* will be taken as the type disease for this chapter, because it has been of such great military importance in our own service, and because it has so recently been almost eliminated from that service, and it may well serve as a striking object lesson in hygiene, but the general statements made are applicable to the other infections that are transmitted in a similar manner.

The exciting causes of these diseases are as follows; Typhoid fever is caused by a bacillus that is found in the bowels, gall-bladder, blood, and internal -, organs of those having the disease. It is an actively mobile organism, does not form spores, is easily killed by heat, and does not, under natural

^ Para-typhoid, of which at least two yarieties exist, haa only been separated from typhoid for a few years, and even now the diagnosis rests entirely on the identification of the causative bacilli, which in turn bear a close resemblance to one another. For this reason most statistics and descriptions of typhoid also include para-typhoid.

226 THE PREVENTION OF EPIDEMICS

conditions, produce disease in other animals than man. Cholera is caused by a vibrio or spirillum, a spiral bac- terium that occurs in the intestinal discharges and con- tents of persons having the disease. It is actively mobile, multiplies with great rapidity, and in so doing the spirals break into comma-shaped fragments, whence the name comma bacillus. It does not form spores, is easily killed by heat and acids, and succumbs to the action of sunlight more promptly than most other organisms. Dysentery is a name applied to a group of symptoms rather than to one specific disease. Consequently it is due to several causes. One class of cases is caused by a group of closely related bacilli that present some differences, another to an amoeba, an animal parasite, and still others to other microscopic animal parasites. Intestinal infestations with worms have already been discussed.

Every case of any of these diseases is derived from some other case. We may at times have great difficulty Q . . in tracing the origin of given cases, but the

, „ . more we learn about the diseases the more J . evident the truth of the preceding sentence

becomes. Diet and unsanitary conditions promote the spread of, but cannot originate, typhoid. The germs must be introduced by man and are so in- troduced. The man who first brings infection to a camp may have the fever and not know what is the matter ; he may be recovering from it and still not know, or he may have had it and recovered long before, but be a *' carrier " and continue excreting bacilli for years. As showing the prevalence of typhoid fever in the general population of the United States in 1898, the following conclusions of the Reed Board are of great interest : —

ALIMENTARY TRACT INFECTION 227

" (1.) During the Spanish War of 1898 every regi- ment constituting the First, Second, Third, Fourth, Fifth, and Seventh Army Corps developed typhoid fever.

'* (2.) More than ninety per cent of the volunteer regiments developed typhoid fever within eight weeks after going into camp.

" (3.) Typhoid fever developed also in certain regu- lar regiments within three to five weeks after going into camp.

" (4.) Typhoid fever became epidemic both in the small encampments of not more than one regiment and in the larger ones consisting of one or more corps.

"(5.) Typhoid fever became epidemic in camps located in the Northern as well as in those located in the Southern States.

" (6.) Typhoid fever is so widely distributed in this country that one or more cases are likely to appear in any regiment within eight weeks after assembly.

" (7.) Typhoid fever usually appears in military ex- peditions within eight weeks after assembly."

Because of increase of knowledge of the methods of transmission, and the dissemination of that knowledge by state and local boards of health, by doctors, socie- ties, magazines, and newspapers, because of improved water supplies, sewage disposal, anti-fly campaigns, and other advances since that time, it is probable that the general conditions are not nearly so bad as they were then, while experience has demonstrated that introduced typhoid is not now allowed to spread as it then did. The improvement in general conditions is not limited to our own country, nor do we lead in it. In fact, we have been behind both England and Germany in much public health

228 THE PREVENTION OF EPIDEMICS

work, and the latter nation has long led the world in its low typhoid rate.^ America's bad showing was proba- bly dependent on several factors, prominent among them being (1) our very widely scattered population, (2) the great extension of typhoid to all parts of the country by soldiei's of the Civil War, (3) poorer and less enlight- ened medical and public health service than in Ger- many, (4) ignorance and indifference on the part of the public. The first of these factors still obtains, though modified by improved facilities for transportation, the influence of the second is beginning to yield to opposi- tion, the third is being corrected as rapidly as may be expected, and that the fourth follows the third is shown by the generous support now given by the public to many movements for the improvement of health, by the prominence given such subjects by the papers and mag- azines, and by the fact that many line officers do know and all have it in their power to know more concerning the methods of spread and the means of prevention of typhoid than did the medical officers of 1898.

Methods of Transmission

Investigators generally now regard sick and healthy carriers to be the source of typhoid, while some of the ^ . most eminent of them regard endemic ty-

phoid, that is, typhoid always present in a place, as nearly always due to healthy, chronic carriers. A carrier of typhoid is a person who passes the living

^ Professor Max Rubner, Director of the Hygienic Institute, Uni- versity of Berlin, said in 1913, " As a young man I saw the mighty typhoid fever epidemics in our country, especially in Munich, my na- tive town, which formerly decimated the population : to-day typhoid fever has diminished, as I have been told by a clinical friend, until there is not sufficient typhoid fever for the clinical lectures."

ALIMENTARY TRACT INFECTION 229

and virulent bacilli from his body, usually in his feces or urine, in such a condition that they may infect other persons. The carrier may be just entering on the disease, may be very sick with it, or may be in good health. In the last named instance he may have had the disease and recovered from it, or he may be merely a " contact carrier," a person who has obtained the germs from an- other case and in whom they multiply, but one who has never been sick with the disease. Ordinarily the term " carrier " is used as meaning a chronic carrier and well person, but a person in the early stages of the disease, who continues at his work, is quite as dangerous, and some of the most serious typhoid epidemics of recent years have been due to carriers of this type. This in- cludes the cases of " walking typhoid." As tending to show how commonly infected persons continue at their work, the following conclusions of the Reed Board may be quoted : " (43.) In addition to the recognized cases of typhoid fever, there were many short or abortive at- tacks of this disease which were generally diagnosed as some forms of malarial fever." " (46.) Army surgeons correctly diagnosed about half the cases of typhoid fever." Since that time the methods of diagnosis have so greatly improved that the disease can be detected with much more certainty and touch earlier, with result- ing improvement in its control, but even yet early cases are a source of great danger, for the reason that diag- nosis is not always sought early by the patient, who is apt to think that he has only a bit of indigestion or a cold. An examination of the blood of every patient showing any sort of febrile intestinal disturbance at Val de Grace in 1907, '08, and '09 showed typhoid bacilli in forty per cent of them, though in many there were no

230 THE PREVENTION OF EPIDEMICS

other symptoms suggesting typhoid. The actually bed- fast patient is less apt to spread the disease widely be- cause of the limitation of his activities. Except that his dejecta may be disposed of so carelessly as to infect water supplies, he is mainly dangerous to his attendants.

The chronic carrier, however, is a menace to nearly all with whom he deals or comes in contact, because neither be nor they suspect that he is a source of danger. Since the investigation of the first recog- nized chronic carrier, many interesting cases have been studied and their histories worked out, and, as they illustrate the dangers from this source, a few of them will be detailed. The first case reported was that of the female proprietor of a bakery in Strassburg. All of her employees would sooner or later get typhoid, and the cause could not be located. It was at length ascertained that the woman, who had had typhoid ten years pre- viously, was still passing very large numbers of typhoid bacilli in her stools. In a British reformatory there had been intermittent outbreaks of typhoid, three, four, or five cases occurring at a time. Inquiry pointed to milk as the cause, but inspection of the dairy and its sur- roundings showed good sanitary conditions. Neverthe- less the disease continued to appear. Search among those handling the milk in the institution led to the examination of a girl who had had typhoid six years previously. Two examinations of her stools were nega- tive, but the third showed that she was passing typhoid bacilli. Her removal from the kitchen ended the epi- demics.

The first instance thoroughly worked up in America was a very instructive one. The investigation began with the efforts to trace a small epidemic, six persons

ALIMENTARY TRACT INFECTION 231

in a household of eleven being attacked with the disease. Thorough investigation at the time of this outbreak and for some time subsequently failed to disclose the source of infection in the food, drink, or general sanitary con- ditions. At length suspicion was directed to a cook who had worked in the house for a few weeks, beginning about three weeks before the appearance of the disease. With great difficulty Dr. George A. Soper was able to trace part of her history during a period of ten years, in which she was known to have lived in eight families where inquiries could be made. In seven of these she had been associated with typhoid outbreaks, always escaping the disease herself. In the seven families there were twenty-six cases of typhoid, with one death. Owing to the cook's refusal to tell anything about herself, and the fragmentary character of the history obtained, it is probable that she had been associated with other cases. On the information obtained, however, the New York Department of Health caused her removal to the Deten- tion Hospital, where she was examined, in spite of her objections and resistance, and was found to be passing great numbers of typhoid germs in her feces.

Another striking case is reported from Prussia, where typhoid had been epidemic on a large estate for four- teen years. During that time there had been thirty-two cases of the disease among one hundred and eighty persons on the estate. Investigations focused attention on the dairy, all of the persons involved having used milk from it. A woman employed there had had typhoid seventeen years before, and the bacteria were found in her stools almost to the exclusion of other varieties. She had worked in the dairy fourteen years, and had been spreading the disease during that time. Instances

232 THE PREVENTION OF EPIDEMICS

of epidemics caused by chronic carriers have been very numerous and such carriers are well recognized as one of the more common causes of epidemics. Usually the epidemic is due to the fact that the carrier deals in or handles food for other persons. That such is not always the case, however, is shown by such instances as the following: A nursing mother had typhoid and her in- fant was taken to a friend's house. The child had a slight diarrhoea but was being weaned, and no particu- lar attention was paid to this until, one after another, six members of the friend's family developed tj-^phoid. Examination of the child's blood then showed that it had typhoid.

The case of a sailor investigated in San Francisco is of striking interest. In three years and seven months there were 26 cases of typhoid on a ship whose crew num- bered 21 men, and this sailor, who had had typhoid four years before, was found to be a carrier and almost certainly responsible, though he did not handle foods as cook or kitchen helper. The close and intimate con- tact of life on a small vessel gave him the opportunity to spread the infection. A case known to the writer has suggested the thought that a prostitute who happened to be also a chronic carrier might scatter the disease by plying her trade. Conversely, as the infection in male carriers is at times localized in the seminal ves- icles, it is possible that such a one might infect the female having intercourse with him.

Still, as said before, the danger usually comes through contamination of food, and the very great importance of cleanliness on the part of cooks and other persons handling foods, and the necessity of investigating the kitchen in the case of company outbreaks, should al-

ALIMENTARY TRACT INFECTION 233

ways be borne in mind. A severe company outbreak at Fort D. A. Russell in 1909 was found to be due to contamination of food by men working on kitchen police while in the early stages of the disease.

About five per cent of typhoid cases are carriers after their recovery. They may remain such for months or for years. Epidemics have been traced to persons who were carriers after attacks occurring more than fifty years previously, and more than one instance of " family predisposition " to typhoid has been traced to a family grandmother who had been distributing the infection with food prepared for the rising generations.

As already stated, healthy carriers of cholera are well recognized, and epidemics have been traced directly to them. So far as is known, however, they do not re- main carriers for many years as do typhoid carriers, eight weeks being a long period. The belief that this is true is strengthened by the history of cholera in Italy in 1911 and 1912. In the former year it caused 7000 deaths, but it died out in the winter and did not re- appear in 1912. This would scarcely have been possible with so extensive an outbreak of typhoid. Dysentery carriers are also numerous in some countries, and some of them remain carriers for many years. They are com- mon in the Philippines.

The effort is always made in our military practice, and in the better class of civil institutions, not to discharge typhoid or cholera patients from hospital until repeated examinations of stools and urine have shown that they no longer excrete the causative bacilli.

Water was not found by the Reed Board to be an important factor in the spread of typhoid in the national encampments in 1898; but

234 THE PREVENTION OF EPIDEMICS

it has so often been demonstrated as the most impor- taut factor in other epidemics, that all authorities agree in considering it one of the first subjects to be investigated in case of any outbreak. This method of transmission is so well recognized and so generally known that it is not necessary to cite any of the very numerous instances showing it. Prior to 1898 practi- cally all of the great epidemics that had been studied wei'e traced to infected drinking-supplies, and the dis- ease was regarded as mainly, if not entirely, water- borne. This fact helps to account for the size and extent of the great camp epidemics of that year. Cholera and dysentery have also usually been traced to infected water. There is, however, the possibility that both may be transmitted in the other ways to be considered.

The germs may be ingested directly in polluted drink- ing water, and such is the usual method in large epi- demics due to water. The danger in such instances of course increases with the dose of germs, that is, with increase in the degree of pollution or in the length of time the water is used. It may also occur in less obvious ways. Thus, water that is used in clothes-washing or bathing may become infected from the clothing or per- sons of sick men or carriers, and may later infect the hands or persons of the people handling or using it, or the vessels in which it was contained. Or men may con- tract the disease by bathing or swimming in infected streams or pools, and inadvertently taking water into their mouths, noses, or, possibly, their eyes.

The influence of water in spreading typhoid is well shown by the drop in typhoid deaths in cities putting in new and good water supplies. The statistics of deaths in 6fty such cities showed, upon examination in

ALIMENTARY TRACT INFECTION 235

1913, very great improvement, the most striking in- stance of it being in Pittsburg, where the typhoid deaths per 100,000 of population fell from 74.3 to 12.7, and in the districts getting the good water to 6.9.

The U. S. Public Health Report for August 7, 1914, contains an article on "Safe Ice" which concludes with the following summary: —

" 1. Clear ice is, of itself, as free from the danger of conveying infectious diseases as we need wish.

" 2. Dirty or cloudy ice may be dangerous. It should not be placed in water nor on food which is to be eaten uncooked.

" 3. There may be danger in eating iced foods or using iced drinks if the ice is improperly handled when placed in contact with the food or drink.

" 4. We may eliminate all danger by avoiding the handling of ice with dirty hands, by washing the ice with pure water, and by using only clear ice.

" 6. The average laboring person does not always have the opportunity, even if he have the inclination, to cleanse his hands after attending to those necessities of nature which require their use for purposes which almost invariably result in their contact with excreta which may contain the organisms of disease, even in apparently healthy people.

*' It is therefore impossible to overestimate the dan- ger resulting from the handling of ice by unknown per- sons if the ice is placed in direct contact with drinking water. Consequently in hotels, cars, stations, and simi- lar places where intelligent personal supervision is im- possible or impracticable, those furnishing the water should be instructed, and indeed compelled by law, to

236 THE PREVENTION OF EPIDEMICS

adopt such means of cooling water as do not require direct contact of ice and water."

Milk-borne epidemics of typhoid are also well recog- nized, and many of them have been thoroughly studied. The milk is, in the great majority of in- stances, contaminated from the hands of milkers, dealers, or other handlers who are suffering from beginning typhoid and have not yet ceased work, who are convalescing from the same disease, or who have had it formerly and are still " carriers," The con- tamination may occur in other ways, such as the use of infected water for washing cans or diluting milk. It may also linger long in cans once infected, if they are not properly washed and sterilized, as the germs will multiply in milk. As the same thing is true of the germs of cholera and dysentery, they may also be milk- borne.

One of the largest milk-borne epidemics of typhoid fever occurred in the suburbs of Boston in the spring of 1908. Four hundred and ten cases occurred, the in- fection being traced to a milk-dealer who continued his work for two weeks after the onset of the typhoid fever from which he later died.

An epidemic of 295 cases at Worcester, Massachu- setts, in 1911, was traced to milk infected by a carrier who had had typhoid twenty-six years previously. That both of these epidemics are reported from the same state is an indication of the thorough investigations and reports made in that state, and not to any greater prevalence of typhoid there than in other states.

Lettuce, radishes, and other vegetables or fruits that are eaten uncooked may be contaminated by unclean handling, by washing in polluted water, by contact with

ALIMENTARY TRACT INFECTION 237

typhoid feces or urine in manure, by flies, or by in- fected dust blown and deposited on them. Bread, cool meats, and other food-articles , , ",

may also be contaminated in some of these ways after they are cooked. Any article so polluted might cause the disease if it were eaten.

An interesting typhoid outbreak in the German army, reported in 1909, was traced to a woman carrier who prepared vegetables in a maneuver camp. The very careful investigation made indicated that 124 men were probably infected, though only 27 of them were sick enough to be classed clinically as typhoid. Yet any or all of them might have been sources of danger to the commands to which they belonged.

The avoidance of uncooked fruit and vegetables from and in places where cholera prevails is a matter of great importance.

Many epidemics of typhoid fever have been traced to the consumption of oysters and other shellfish gathered from sewerage-infected beds. For twenty- five years the city of Belfast had had the ®

greatest mortality from typhoid of all the cities in the United Kingdom, in spite of a good water-supply and good general sanitation. A commission appointed in 1907 to investigate the matter showed that the endemic prevalence of the disease was due to the unrestricted gathering of cockles, mussels, and other shellfish from the " slob-lands " of Belfast Lough, which are laden with the city's sewage. Hundreds of acres are exposed at low tide, and the shellfish are gathered by the poorer classes, who generally eat them raw. The Jews, who do not eat them, were exempt from the disease. It is prob-

238 THE PREVENTION OF EPIDEMICS

able that cholera and dysentery may be transmitted in the same way.

Living and virulent typhoid organisms have been found in the mouths of persons sick with the disease, and the vomit of cholera may contain the germs of that ailment. It may therefore be understood that the common use of drink- *^ ing-cups, clinical thermometers, and other

articles that are put to the mouth, may lead to infection. In all of the diseases discussed in this chapter the or- ganisms occur in the intestines, and careless use of rectal syringes may spread them. Such an accident is, of course, more apt to occur in hospitals.

None of these diseases is air-borne in the sense that smallpox and scarlet fever are, but feces, urine, or other material containing the causative or- ganisms may be scattered as dust when well or partially dried and pulverized, and may be inhaled in that form, or may light on articles of food or drink and be ingested with them. The Reed Board reported : " (31.) It is probable that the infection was disseminated to some extent through the air in the form of dust."

" (28.) Flies undoubtedly served as carriers of the infection. Flies swarmed over infected fecal matter in the pits, and then visited and fed upon food prepared for the soldiers at the mess tents. In some instances Flies where lime had recently been sprinkled over

J the contents of the pits, flies with their feet

other whitened with lime were seen walking over

Vermin *^^ food. It is possible for the fly to carry the typhoid bacillus in two ways. In the first place, fecal matter containing the typhoid germ may adhere to the fly and be mechanically transported.

ALIMENTARY TRACT INFECTION 239

In the second place, it is possible that the typhoid bacillus may be carried in the digestive organs of the fly and be deposited with its excrement."

Several asylum epidemics of dysentery, notably one at the Dan vers State Hospital (Mass.), have been shown to be spread by flies, and the large annual epidemics in Fiji from December to March have been ascribed to the same agency. Flies caught during an Indian epi- demic of cholera in 1912 were found to have cholera vibrios both on their external appendages and in their intestinal canals.

Recent work in the Philippine Bureau of Science has shown that cockroaches fed on human cholera feces may harbor cholera vibrios in their intestines, and these may appear in enormous numbers in the insect's feces for at least two days after the feeding, and in smaller numbers for a longer time, and if deposited on human food with the cockroach feces they may there survive for another four days. By means of either feces or vomit from cholera cases the cockroach may carry in- fection to human food. The same investigation showed that cholera vibrios may be found in the bodies of ants for eight hours after they have ingested feces from cholera patients. There is little room for doubt that both of these insects could carry typhoid, probably more readily than cholera.

It would be well for the line officer to know the following facts concerning house-flies. They breed in horse-manure, human feces, and other filth, and can readily emerge through six inches of loose earth, but not through earth saturated with water. When breed- ing in feces, the larvae will go into the earth five or six inches as the feces dries, and there find more congenial

240 THE PREVENTION OF EPIDEMICS

surroundings. Flies are naturally most numerous about manure piles, trench latrines, and kitchens, because they find in those places the best breeding and feeding places respectively. The female lays about 120 eggs, and the development of these varies with the tempera- ture, in the tropics somewhat as follows : —

Hot Weathkk Cold Wkathbb Days Days

Eggs hatch in 12

Maggots change to pupse in 5 14

Pupse change to adult flies in 3 5

Total Short 9 long 21 or more

In temperate and cold climates all the stages of the fly's life may be prolonged, so that the full change from adult to adult may require as much as two months, while adults and possibly pupae last through the win- ter and start the cycle again in the spring. The fly does not pupate in a wet medium if the full-grown larvae can find means of migrating to a dry place protected from the sun; for example, at the edge of the manure pile, under boards, or in cracks. Here the pupal cases may be found as small, brown shells the size of plump grains of wheat, and in great numbers. It has been found that bacteria such as those causing typhoid sur- vive much longer in than on flies, and longer in the in- sect's gut than in its deposited feces. A study of the flies of New York City in 1911 brought out the follow- ing facts that are of interest as bearing on the seasonal occurrence of typhoid and summer diarrhoea (bacillary dysentery). Up to the end of June the flies were found to be practically free from fecal bacteria. During July

ALIMENTARY TRACT INFECTION 241

and August the flies examined carried millions of bac- teria, whereas at other seasons they carried hundreds only. Fecal bacteria of the colon bacillus type were first found abundant in July. The bacteria were 8.6 times as numerous in the intestines as on the surface of the flies. Extensive experiments and observations in Cambridge, England, indicate that houseflies tend to travel against or across the wind, apparently attracted by odors. The chief conditions favoring dispersal of flies are fine weather and warm temperature. They do not travel as far in towns as in the country, the maxi- mum flight observed in thickly populated parts of Cambridge being a fourth of a mile, while in the open country single fliglits may double that.

Contact with sick persons offers many opportunities for both mediate and immediate infection, and the class of diseases under discussion often infect r* t i- nurses and attendants. The typhoid patient, as stated before, may give off the germs of the disease from his bowels, bladder, or, occasionally, his mouth. From these sources the bacilli get on towels, bedding, urinals, chamber pots, the patient's skin, and into bath water. Any of these articles may be handled by nurses, associates, or casual visitors, who may thereby infect their own hands or persons, and later take the germs into the mouth. Persons using the same drinking glasses, linen, or other personal articles, as the sick man, are especially apt to be infected. This method of infection is now regarded as very important. The greatest care in cleanliness and disinfection is necessary on the part of all hospital attendants and others brought in contact with the disease. The danger is of course greater if the nature of the disease is unknown, and the subject pur-

242 THE PREVENTION OF EPIDEMICS

sues his ordinary course of life, eating, drinking, sleep ing, defecating, and urinating, with no thought of being a menace to others.

Tent-mates and bed-mates, and members of the same family and household, are particularly exposed. The Reed Board published the following conclusions that bear on the subject: " (30.) Typhoid fever, as it devel- oped in the regimental organizations, was characterized by a series of company epidemics, each one having more or less perfectly its own individual characteristics. . . . Of 1608 cases of typhoid fever which we have been able to accurately locate in the particular tents in which they occurred, together with the date of the commence- ment of the attack, the results may be summarized as follows : —

" Directly connectable attacks, 563, or 35.01 per cent.

" Indirectly connectable attacks, 447, or 27.79 per cent.

"Total connectable attacks, 1010, or 62.8 per cent.

. . . "We believe, therefore, that personal contact was a very important factor, probably the most im- portant, in the spread of the disease."

The Germans, after years of careful and most valu- able work by a government commission on typhoid in southwest Germany, regard contact as the main method of spread of the disease. The contact is with the sick, the sickening or the healthy carrier, but usually with one just sickening. The German commission found typhoid bacilli in the blood of an apparently healthy boy of twelve, whose sister, in the same house, had the disease. Four days later the boy sickened. He was a source of danger even before he appeared sick. Exam-

ALIMENTARY TRACT INFECTION 243

ination of 600 cases of typhoid in the Saar district showed that a large proportion of contact infections must have occurred during or before the first week of sickness of the infecting cases, even assuming the in- cubation period to be so short as ten days. In fact, more than half of the contact cases seemed to have been in- fected thus.

Contact infection was the main cause of the spread of cholera in the Bulgarian army in 1913. Recruits neglected to use latrines, soiled the ground, and later infected their hands in removing shoes and clothing.

It will be readily understood that the dangers of contact would be greatly increased by crowding, poor ventilation, and uncleanly habits.

House epidemics of cholera are common in the Philip- pines during epidemic seasons, and owe their origin and spread to the causes discussed above, to the common use of food and drinking utensils, and to infection con- tracted in cleaning up vomit and watery stools. There is good reason to think that dysentery and diarrhoea may be spread in the same ways, while it is well known that intestinal worms often are, among children.

The above discussion of the dangers of contact with sick persons may be applied equally well to similar re- lations with carriers, except that they are not known to their associates to be sources of danger, and are thereby rendered mpre harmful. They are more apt than sick men to sleep with other persons, to lend or borrow clothing, to be put on duty in kitchens, or han- dling foods, or caring for cows, while no precautions are taken in the matters of disinfecting their clothing, stools, or urine.

It does not require lengthy argument to demonstrate

244 THE PREVENTION OF EPIDEMICS

that, if urine and feces contain disease-producing germs

and are deposited on the surface of the ground about

_ ., , camps or are allowed to soil the edges

Soiled , . . . f , . , .

and vicinity of latrines, men may get their

shoes soiled with such matters and the con- tained germs. Such being the case, the contamination might easily be conveyed to tents, bunks, company streets, and the hands of the men. Needless to say, such infection could be conveyed even though all gross evi- dence of fecal or urinary soiling were removed.

The term fomites includes such inanimate articles or substances as are thought capable of absorbing, preserv- _, . ing, and transmitting tlie contagion of dis-

ease, and is used as a general designation for such things as books, clothing, tents, bedding, and baggage. Clothing that is grossly contaminated, such as sheets or shirts soiled by the diarrhoeal discharges of sick men, is, of course, most dangerous, but the danger in such cases is apt to be recognized and provision made for it. On the other hand, bedding soiled by dirty shoes, tents that have been urinated upon, the clothing of apparently well carriers, and other articles may be infected and show no signs of it, and so do great harm.

Laundry-workers, hospital attendants, and tent-mates of the sick are naturally more liable than others to infection in this way; yet all may be exposed to it in time of epidemics.

Prevention and Control

The general measures for the prevention of these

diseases are those hygienic precautions that have been

discussed in preceding chapters. If cases do begin to

appear in a command, it is evident that they have not

ALIMENTARY TRACT INFECTION 245

been sufficient, and more vigorous steps should be taken to protect the men not yet infected. If they show in the neighborhood of the command, or along lines of communication with it, the same active measures should be adopted. The best prospects for the prevention or control of the epidemic will be offered if the following steps be taken.

One of the most important of these is early diagnosis of the dangerous cases. As long as their nature is un- known, they continue to disseminate the — , disease-germs ; and such undiagnosed or _. wrongly diagnosed cases apparently had much to do with the spread of typhoid fever in the camps in 1898. At that time the methods of diagnosis were not so good as at present, and a positive diagnosis of typhoid could not usually be made until after the patient had been sick a week or more. Laboratory methods now permit of it sooner, but they are not always available, and the safe rule is to regard and handle suspected cases as though the disease were known to be typhoid.

The diagnosis is a matter for the medical officer to worry over, but the line officer can be of assistance if he instructs his men to go on sick report if they are not well, and if he does not unduly encourage the notion that men only seek sick report to escape work. It is at any rate better that two or three frauds should be allowed to loaf for a time than that one sick man should be allowed to spread disease through the command. The Reed Board made the following findings that bear on the difficulties and importance of early diagnosis : —

" (46.) Army surgeons correctly diagnosed about half the cases of typhoid fever."

246 THE PREVENTION OF EPIDEMICS

" (14.) A man infected with typhoid fever may scat- ter the infection in every latrine in a regiment before the disease is recognized in himself."

Diagnosis is of no value in the prevention of epi- demics unless it leads to immediate steps to prevent T lat'nn i^^^ction through contact, soil - pollution, water -pollution, and in other ways. It should therefore lead to the isolation of all recognized or suspected cases, and such measures of care as will prevent their spreading the disease in any of the ways discussed in this chapter. Such measures must include screening from flies, disinfection of clothing and linen, of bath water, dishes and utensils, of stools, urine, and spit. Only the necessary attendants, and they well- trained ones, should have access to the patients. The isolation should at times include suspects who have been exposed to disease as well as the actually sick. This is particularly true as regards cholera. It is neces- sary in a less degree for typhoid, and still less for dys- entery. Whenever resorted to, such isolation should more than cover the ordinary period of incubation of the disease. Cholera suspects should be isolated for five days, those suspected of typhoid for three weeks or un- til well and free from bacilli. In the latter disease such strict isolation may not be necessary, but in case of se- vere epidemics it will be wise, and can be done in iso- lation camps, where the men can work, drill, and play. At times it may be advisable to quarantine entire or- ganizations as suspects, or to direct the measure against towns or communities.

Isolation cannot be made an effective measure of disease-prevention unless it includes all cases of the disease in question, and, in many instances, all sus-

ALIMENTARY TRACT INFECTION 247

pected cases. It is, therefore, essential that all cases and suspects be promptly reported to the central au- thority, in order that proper steps may be _, .

taken. It is only rarely that difficulty will _

1 . 1^ -0. J ^1 M- Bory Re-

arise in this matter as it regards the mili- ' .

, , . '^ . .,. porting

tary personnel ; but cases among civilians t r*

and residents of the locality in which the troops are quartered may be willfully concealed. Epi- demics " hurt business," and often interfere with trans- portation and traffic, and for this reason and others it is not uncommon that great efforts are made to hide or deny their existence.

It therefore occasionally becomes necessary to make regular and frequent inspections and examinations of all persons in camp, and less frequently of _, . , those in the neighborhood. If the commu- _ nity is under military control, this may be a . relatively simple matter, but where such is not the case it may be one of extreme difficulty, and call for the display of much forbearance, good temper, and tact. When such measures are necessaiy, they should be under the charge and direction of medical officers who will see that they thoroughly accomplish their purpose, but at minimum of inconvenience, and that they are conducted in such a manner as to gain rather than alien- ate the sympathy and the cooperation of the civil pop- ulation and its medical practitioners. If many sick are found it may be necessary, in order to control the epidemic, to establish large isolation camps and special hospitals for civilians. The gathering of large crowds from many places, as in pilgrimages, fairs, and religious festivals, should be particularly forbidden during chol- era epidemics. Health-inspections may also be made

248 THE PREVENTION OF EPIDEMICS

the means of much sanitary instruction, and may thus do great good in addition to that accruing from a know- ledge of the location of cases. Such inspection, exami- nations, and instructions have been resorted to in times of cholera epidemics, and among peoples living under military control, with great success. They redound to the benefit of the civil as well as the military population. Inspections of troops for the presence of disease are not infrequently resorted to, and often do much good.

Every case of any of these diseases that is reported or discovered should be investigated as thoroughly as T *j possible as to its origin. This investigation

may show no results in single cases, but p, when the findings in many cases are com-

pared they may give important information as to the cause of the epidemic. Thus it may be found that it is confined to persons using a certain water, to those consuming milk sold by a special dealer, or who eat the productions of a certain cook, or who have partaken of shellfish ; or that the cases are otherwise connected in some way. The information thus gained may direct attention to the cause of an epidemic, and its removal may put an end to the whole matter. The trac- ing of epidemics is, however, often a difficult matter, and the detection of typhoid-carriers is particularly so. If, for instance, a carrier were put on kitchen police for a day and infected the food of a company, a dozen men might contract the disease as a result. They might de- Telop it, however, in from one to three weeks, or possibly more, and meanwhile a large number of men may have worked in the kitchen, and many other factors having an apparent bearing may have come to light, so that all thought is diverted from the man really causing the

ALIMENTARY TRACT INFECTION 249

trouble. However, the report of a well-studied carrier- caused epidemic of 93 cases in Hanford, California, in 1914, showed that more cases developed on the sixth than on any other day, two thirds of all cases appeared by the tenth day, and one case developed in three days.

In very many instances the cause of the epidemic can- not be ascertained, or at least not soon enough to permit its removal in time to prevent numerous infections, and protection must be sought in the practice of such general preventive measures as are applicable. These should take into consideration the various methods in which the diseases are transmitted, and will embrace the fol- lowing.

Cleanliness of persons, tents, kitchens, and camps is of paramouut importance, and officers should encourage it by precept, example, orders, and, if nee- ^ .

essary, punishment. Those associated with -_ the sick should be particularly careful as to their persons, surroundings, and food. They should keep clean tents, wash themselves frequently, disin- fect their hands after handling the sick, their bedding, clothing, or other personal belongings, should be care- ful not to use the same drinking or eating utensils, and in other ways should avoid the dangers of contact. Disinfection of clothing, bedding, tents, rooms, bar- racks, urinals, latrines, and all the things used by the sick man, should follow his removal from the barracks, tent, camp, or temporary hospital. Articles that cannot be well disinfected, such as hats and leather gloves, should be destroyed if probably infected. Latrines that are infected should be disinfected as well as possible, and, if pits or other cheap arrangements, closed. Great care should be taken to make sure that all latrines are

250 THE PREVENTION OF EPIDEMICS

fly-proof. General good hygiene should prevail. Sun- shine and fresh air should be provided in abundance to destroy and dilute the poison ; temperance, order, and regularity of habits encouraged, overwork and idleness alike avoided, and cheerful and rational living enjoyed. The ground should be kept so clean as to leave no opportunity for fecal or urinary contamination of shoes, no breeding-places or food-supplies for flies or roaches, and no infected dust to blow about. The effect of not doing these things is seen more promptly in cholera than in typhoid, because the incubation period in the former is shorter and effects become manifested before causes are forgotten. In that instance, lack of sunshine, intemperance in food and drink, fear, and unhygienic surroundings are regarded as important predisposing causes of the disease. Increased care and attention should be given to the disposal offeces^ urine, vomit^ and other wastes, and to the elimination of fiie& and other insects and protection from them. Cremation of waste materials should be resorted to if practicable. Men should be instructed to use only the latrines and urinals of their own companies so far as it is possible to do so, and under no circumstances to urinate or defe- cate on the ground. The Reed Board reported : " (15.) Camp pollution was the greatest sin committed by the troops in 1898."

Cleanliness of camp-sites and good general police are therefore of very great importance, both as preventing accumulations of infective material and as keeping down flies and other vermin. The Reed Board pub- lished an important conclusion bearing on this : —

" (37.) The fact that a command expects to change its location does not justify neglect of the proper polic-

ALIMENTARY TRACT INFECTION 251

ing of the ground occupied. ... A camp-site should be thoroughly policed up to the moment of vacating it. This should be insisted upon as a matter of military discipline, and camp commanders should regard proper attention to the sanitation of the site occupied by their troops as one of their highest duties, and its neglect as a crime."

Recent experiments show that typhoid bacilli can re- tain their virulence in soil for several weeks or months.

When, because of want of foresight, neglect, or for any other reason, a command is located on a polluted site, a change may be desirable. This can- not be depended upon to rid the command r cs- of infection; and disinfection, isolation, and the other measures herein advocated must continue to be used, but the change may at any rate reduce the number of channels of infection. The dust blown about camp would be less dangerous, the number of flies smaller, and the opportunities for fecal contaminations fewer, in the new camp.

The water used for drinking, dishwashing, and sim- ilar purposes can, of course, be sterilized by boiling ; but as many men seek other water to drink, it is .^ desirable that only a pure supply be avail- able, and if one purified by large filtration '^^ ^

plants or other means is to be obtained, it should be. At times it may be necessary to take steps to guard the purity of a supply known to be good. Reservoirs, fil- ters, or watersheds may need to be patrolled to prevent their contamination. Bathing in drinking - supplies should of course be prevented. The rule to be followed always in time of epidemics is, however, to drink no water not purified by heat. No matter how good a

252 THE PREVENTION OF EPIDEMICS

general supply is to-day, the possibilities of infection are so many, and so hard to guard against, that there is no certainty as to the purity of to-morrow's supply.

Ice, unless made from distilled water and handled with all possible care, should not be allowed to come in contact with articles of food or drink during the prevalence of epidemics. It may contain germs frozen in it, or they may have been deposited on the surface by improper handling.

The safest rule as to foods is the same as that just applied to water, — to take none that is not sterilized. _, J This rule is pretty generally applied by

« , Americans in the Philippines, especially

during cholera epidemics, but it has not had such general application in our own country or as a measure of defense against typhoid. Heat is the means of sterilization for most foods, and cooking the method of applying it. However, such articles as bananas, mangoes, apples, cucumbers, melons, that are protected by a thick skin or rind, may be washed in bichloride or other antiseptic solution, and later peeled. The use of pies, soft drinks, milk, and similar articles sold by peddlers, is in general to be deprecated, and it may be advisable to stop such sales. Green vegetables may also have to be banned, particularly in cholera times and where dysentery and the practice of manuring with human feces coexist. If either typhoid or cholera appears in the person or family of a dealer in food- stuff or milk, his business should be stopped at once, or allowed to continue only under such rigid rules as will destroy all chance of dissemination of the infection. If the person cannot be controlled by military authority, the soldiers should be forbidden to deal with him.

ALIMENTARY TRACT INFECTION 253

Typhoid, cholera, and bacillary dysentery are all dis- eases in which protective value has been attributed to the injection of the living or killed germs beneath the skin, the procedure commonly ^ spoken of as vaccination against the dis- eases. Vaccination against dysentery has had relatively little use, but good results have been claimed. The use of cholera vaccine has been mueh more extensive, and in India, Japan, the Philippines, and elsewhere the results have been considered most encouraging. According to statistics published in 1913 by the originator of the most widely used cholera vaccine, it appears to reduce both the morbidity and death rates to about one seventh of what they are among the unvaccinated.

The latest available figures relating to this vaccine are those concerning its use in the Gi'cek army at the end of the Balkan war. Following an extensive out- break of cholera in the army and the territory occupied by it, 150,000 troops and 350,000 civilians were vacci- nated. The attempt was made to give two injections at an interval of eight days. The immediate effects of the injections were not such as to prevent military duty, and were probably much like those following the use of our typhoid prophylactic. In the whole army about 19 per- sons per 1000 developed cholera. Among the unvacci- nated the incidence was 93 per 1000 and the mortality was 27.5 per cent of the sick. Among those who had one injection the incidence was 42 per 1000, with a mortality of 12.2 per cent, and among those having two injections it was 7 per 1000 with a mortality of 10.2 per cent. That this entire improvement was due to the use of vaccine is improbable, but how much of it was due to improved measures of sanitation and to the general

254 THE PREVENTION OF EPIDEMICS

dissemination of knowledge of the methods of preven- tion that must have gone into effect as the vaccination progressed is not known.

Typhoid vaccine, or prophylactic, as it is officially des- ignated, has had its most extensive use in our own army, and the results have been so good that its use has there been compulsory and universal since 1911. Typhoid has now practically disappeared from the United States army, its incidence and mortality for seven years being shown in the following table : —

Typhoid Incidence and Deaths per 1000 Persons in

the U.S. Army

Year Cases Deaths

1907 3.53 0.19

1908 2.94 0.23

1909 3.03 0.28

1910 2.32 0.16

1911 0.89 0.11

1912 0.26 0.03

1913 0.03 0.00

Just how much of the reduction shown here is due to the use of prophylactic and how much to other fac- tors it is impossible to say. In his annual report for 1913 the Surgeon General sai<i, " It must be especially emphasized that there has been no lessening of the efforts in the army to prevent, by improved sanitary measures, the occurrence of typhoid infection. Advances in the other sanitary measures have gone on, hand in hand, with the extension of the typhoid prophylaxis."

It must be emphasized also that no one is justified, because of his use of typhoid vaccine, in neglecting to care for himself or his fellows in all known ways.

CHAPTER XIII

DISEASES DUE TO INFECTION THROUGH THE RESPIRATORY TRACT

To group the diseases discussed in this chapter under the above heading may be somewhat misleading, but as it is thought that all of them do frequently gain admission to the body by way of the respiratory tract, and some of them always, as the above caption is less misleading than the phrase "air-borne diseases," and as the group cannot be considered as conveniently and satisfactorily in the preceding or the following chapters as in this, the grouping is considered justifiable.

Most of those now to be treated of are also known as contagious diseases. The term is elastic and may be used in different senses, but as ordinarily applied to the diseases discussed in this chapter it may be taken to mean that they are more readily transmissible than most others and are very apt to spread, especially by contact or association.

The principal diseases, from a military standpoint, in this group are measles, scarlet fever, German mea- sles, smallpox, chickenpox, influenza or grippe, mumps, whooping-cough, diphtheria, tonsillitis, epidemic men- ingitis, and acute anterior poliomyelitis or infantile paralysis. It is true, though, that tuberculosis, pneu- monia, pneumonic plague, and some other diseases are sometimes widely spread in the same way.

Some of the diseases mentioned above — influenza,

256 THE PREVENTION OF EPIDEMICS

tuberculosis, diphtheria, meningitis, tonsillitis, plague,

^ . and whooping-cough — are known to be

Causative j u i .. • i xi.

O an ama ^^^^^^ "Y uacteria, and the organisms can

be isolated and identified. The causes of measles, German measles, scarlet fever, and smallpox are still unknown, and it is possible, though not certain, that they are due to organisms invisible with our micro- scopes. Supposedly causative organisms have been de- scribed for each of them, but convincing proof of the relationship has in no instance been produced.

Certain factors have an important influence in pre- disposing to some of these diseases, and enable us to p -. exercise some measure of control over them.

. Most of them are so prevalent in the very

^ young as to be known as " the diseases of

childhood." By this phrase we usually speak of the group including mumps, measles, scarlet fever, German measles, chicken-pox, and diphtheria. Before the era of vaccination, smallpox was also principally a disease of childhood, and produced its greatest mortal- ity among those under five years of age. Thus in " Ge- neva from 1580 to 1760 there were 25,349 deaths from smallpox, and of these 21,078 were under five years old and 961 per 1000 were under ten years old. In Edinburgh in 1764-83, the proportion under ten years old was 993 per 1000. In the Chester epidemic of 1774 there were 202 deaths, all among children under ten years old." All of these diseases do attack adults, how- ever, though less frequently and usually less severely than children.

Season exercises some influence. The cold, raw weather of the late winter and early spring particularly favor most of them, while they are also commoii in wIq-

RESPIRATORY TRACT INFECTION 257

ter and rather rare in summer. Infantile paralysis, how- ever, is more apt to occur in summer than at other times, which fact is one of the several used as arguments that the disease is conveyed by the common biting stable fly, Stomoxys calcitrans.

Crowding favors epidemics, quite apart from the question of ventilation, and it also predisposes to severe attacks. Many cases of a very severe type of measles developed in the concentration camps in 1898, and an epidemic of 600 cases occurring at Columbus Barracks between December, 1910, and May, 1912, was thought to have been aggravated by crowding. School epidem- ics of measles, German measles, scarlet fever, mumps, and diphtheria are rather common.

Poor hygienic conditions, such as dirty surround- ings, the breathing of effluvia from decomposing matter, and bad ventilation, are all thought to predispose to them, and probably do so by reason of the fact that persons exposed to such influences are pretty sure to be living in such a manner as to be subjected to unusual oppor- tunities for too close contact with neighbors.

Unhnown atmospheric conditions apparently influ- ence the rise and fall of some of them. Influenza and diphtheria increase and decrease in ways thus far not fully explained.

A previous attack of one of these diseases usually protects from a second, but such is not the case in all of the group. One attack of diphtheria or influenza, for instance, seems to predispose to a second rather than to protect against it. Second attacks of smallpox, scarlet fever, and mumps are rare, those of measles less so.

These diseases are not all transmitted in exactly the s^me way, but the transfer of no one of them is so

258 THE PREVENTION OF EPIDEMICS

limited as the title of the chapter would indicate ; so

liiT ii. -a the various methods will be considered and

Saetnoos . ^. .

of Tra « exceptions noted as we progress.

. . Some of these affections are coutaffious

mission X 1 1 1 11

to such a degree that near approach to the

patient and breathing of the air surrounding him in a greater or smaller zone, without any contact, seems - . sufficient to allow infection. This is par-

^- ticu.arlytrueof.easles,b.,titiss„fficieLy

true of all the diseases of the group to make isolation ordinarily worth while as a matter of routine in mili- tary practice, and this is none the less true because of the fact that transmission of most of the diseases of the group is by contact, rather than by air-borne infection. The following excellent observations that bear on this point were published in the London Lancet of June 13, 1914.

In a common open ward with good ventilation, hav- ing twelve beds and an allowance of 195 square feet of floor space and 15 linear feet of wall space per bed, there were treated in two years 274 patients with 332 cases of contagious diseases, including 112 cases of scarlet fever, 63 of diphtheria, 24 of chickenpox, 47 of whoop- ing cough, 11 of mumps, 2 of incipient measles, 6 of German measles. At each patient's bed were a table, eating utensils, towels, gowns for nurse and doctor, and such things as the patient needed. No toys, books, or other articles that would be apt to be passed from one patient to another were allowed in the ward. On entering the ward every officer or person who was to touch a patient, his bed, or anything connected with him had to scrub his hands and nails with soap, water, and 1 to 200 solution of lysol at the bedside, to put on

RESPIRATORY TRACT INFECTION 259

a gowu reserved for that bed, and, having finished, to remove the gown and scrub again before leaving the bed. Under this regime secondary cases occurred as fol- lows : Scarlet fever, two cases, due to a nurse ; diph- theria, none ; German measles, none ; mumps, none ; whooping-cough, five cases ; chickenpox, eight cases ; which facts the reporters regarded as tending to show that diphtheria, scarlet fever, and mumps are not air- borne, that measles and chickenpox are so in their early stages, but not after the third or fourth day, and that whooping-cough is probably so for an indefinite period.

As showing the very high degree of contagiousness of measles in its early stages it is well to cite instances from two official health bulletins. In Chicago thirteen children attended a birthday party, two of them hav- ing " colds." Next day both of these two had typical measles. After eleven to fourteen days every child of the party, except one who had had the disease within a year, had measles. One of them developed a cold twelve days after the party, and she was taken from her convent school-room and put for a short time (an hour or less) in a large room with fourteen larger girls. Twelve days later all fourteen of those girls developed measles. Some of these then started epidemics and forty- seven cases were known to result from the first one. Aerial transmission of the contagion seemed very evident in the school-room, where contact could be ruled out.

" A farmer and stockman from the little town of A. went to Kansas City with a carload of cattle. Nine days later he had a bad cold. He spent two days wandering from store to store in the little town telling his friends what a fearful thing his cold was. On the third day the eruption occurred and his physician tacked up a measles

260 THE PREVENTION OF EPIDEMICS

sign on the house. But it was too late. Two weeks later 28 of his friends who had listened sympathetically to his ' cold ' troubles also had measles. In two weeks more 28 other cases resulted, and two weeks later 30 cases — 86 in all. That, being nearly the entire population of the town, ended the epidemic in that community. But of the first crop of 28 cases at A. one visited the home of a physician in the city of B. The physician, not know, ing his child was exposed, permitted its attendance at school regularly, and the child ' broke out ' in school. From this child it spread to 43 families, or 90 cases. A visitor from the city of C. in the town of A. came home, attended the city schools of C. and the disease spread to over 100 cases there. During the county examina- tions held in C, and at the height of the epidemic there, a pupil from the city schools of D. was exposed to the infection. In spite of this knowledge this pupil did not cease school attendance, and thirty cases re- sulted in D."

Healthy persons may be carriers of and may convey diphtheria, cerebro-spinal meningitis, and infantile pa- ralysis ; while persons apparently recovered V/am from them but still harboring the germs

may convey the diseases just named, influenza, and scarlet fever.

Fomites conveyance of infection is of course a form of mediate contact. It is more apt to occur the more recent the contact of the fomites with the sick person, as time, sunlight, drying, and other factors constantly tend to destroy the causative organisms unless these be on substances offering them food and favorable conditions, such as milk, meats, iind other articles of human food. It is for this reason that

RESPIRATORY TRACT INFECTION 261

terminal disinfection of houses after the occurrence of these diseases has of late been found to be much less important than it was formerly considered to be, with the result that it has been almost abandoned in several cities. Of the fomites the most dangerous are toys, handkerchiefs, and such other things as come into close contact with the patient, and especially such as are apt to be contaminated with the secretions from his nose, mouth, or other parts. It is often extremely difficult to draw hard and fast lines separating air-conveyance, dust- and droplet-infection, fomites-oonveyance, and in- fection by direct contact. Where there has been a pos- sibility of infection in one of these ways there have often been other opportunities for it. Infection by direct con- tact we know to be possible in all these diseases, and kissing or sleeping with a person having any of them is particularly dangerous. They are dangerous cases to nurse or to treat, and nurses and doctors r^ a. ^ ofteu contract them, and would do so much oftener except for the protecting influences of previous attacks, age, and constant sanitary precautions.

The virus of most of these affections is given off in the spit and nasal secretions of persons suffering from

them. Such is certainly the case in diph- ^ , . 1 r 1 1 Sputum

thena, scarlet fever, measles, mumps, whoop- *^

ing-cough, poliomyelitis, and sometimes in meningitis,

and it may be true of all the others.

It is quite probable that the virus of some or all of

these diseases may also be contained in other -^. , «

, • r 1 . Other Se-

natural secretions of the patient, or in pus

crcuions or eruptions that sometimes occur. It is

highly probable that the ears may be infectious in

measles, and discharges from the ears and nose are

262 THE PREVENTION OF EPIDEMICS

certainly so in scarlet fever. The virus of poliomyelitis has been demonstrated in the lining membrane of the stomach and bowels.

The eruption of smallpox consists at different periods of papules or pimples, vesicles or little blisters, and g,,. scabs. Both the vesicle contents and the

scabs are known to contain the virus of the disease and are therefore to be avoided. While proof is lacking that the similar products of chickenpox and the scales or strips of skin shed after measles or scar- let fever are dangerous, it is the part of wisdom to avoid them also and to burn them as they are cast off.

In most or all of the diseases here considered the virus is at some time contained in the blood, and contact with that, as in dressing wounds or clean- ing up spilled blood, would probably offer chances of infection.

The introduction of infectious matter into wounds serves to inoculate most of these affections. It is much _ , resorted to in efforts to infect animals for

^ experimental or other purposes, and in pre-

vaccination times inoculation with smallpox was sometimes done as tending to produce a milder attack of the disease than resulted from natural infec- tion.

Infection through the medium of utensils, such as cups, spoons, thermometers, bedpans, or pipes, may -.. ., readily occur, but is an evidence of mediate contact rather than of contagion by virus contained in the air. Such articles can only rarely con- vey the disease in question, unless they have been soiled by contact with the mouth, skin, or other parts, or the secretions of a patient.

RESPIRATORY TRACT INFECTION 263

Animals may convey these diseases in various ways. They may gather up infected dust, sputum, or flakes of skin by lying on or near the sick-bed, . . , and, by shaking themselves, liberate it else- where. It is possible that they might lick up moist sputum or other secretions, and retain the germs alive in their mouths and transmit them through fondling or fawning, even though they do not themselves have, or are not subject to, the disease. In other instances they are subject to the diseases, and may contract them through contact from eating spit, or in other ways, and breed and give off germs just as do human patients. Cats, dogs, and many other animals are subject to diph- theria, and may aid in spreading it. Cows suffer from a disease of the teats which, it has been said, can by means of milk set up scarlet fever in the human sub- ject. Cattle suffer from smallpox in the mild and al- tered form known as vaccinia or cowpox, which, when in turn inoculated into man, affords protection against the first, or more severe disease. Whooping-cough has been transmitted to animals experimentally.

Epidemics of scarlet fever and diphtheria have many times been traced to contaminated milk, and it is not

impossible that several of the other diseases __.,,

J- Ti • V, Milk

we are discussing may likewise be so con- veyed. The milk may, in exceptional instances and in the two diseases just named, be infected by the animal giving it, but the virus is usually if not always derived from some human carrier of the organisms. Milk is a good culture medium for most disease-producing bac- teria, and we have already seen how important it may be in the diffusion of typhoid fever and how readily it may be infected with the germs of that disease. It is

264 THE PREVENTION OF EPIDEMICS

therefore easily conceivable how milk-baudlers suffering from influenza, mild diphtheria, mild scarlet fever, or others of the diseases we have been discussing, might, through coughing, tasting the milk, careless handling of vessels, or in other ways, introduce germs into it. Milk epidemics of scarlet fever, like those of typhoid, are apt to show a somewhat " explosive " character, that is, many cases develop at or near the same time. In Bos- ton, Baltimore, and Chicago very large epidemics of septic sore-throat have been traced to infected milk. The following milk-borne epidemics of the diseases here considered have been investigated in Boston : —

In 1907, 717 cases of scarlet fever from one milk supply. " " 72 " "diphtheria " " " ♦'

"1910, 842 " "scarlet fever " " " " " 1911,1000 " "septic sore-throat" " " " Measles is not thought to be milk-borne.

The virus of any disease having gained entrance to a susceptible body, some time is required for its mul- tiplication and development, and for it to incu - manifest its effects on the body. This time _ between the entrance of infection and the

appearance of the first symptoms of disease is known as the incubation period, and is more or less constant for each disease. As it is important to take this into consideration in attempting to trace, control, or prevent epidemics, the following may be considered as representing it with tolerable accuracy in the diseases named : —

RESPIRATORY TRACT INFECTION 265

Diseases Incubation Pkbiods

Smallpox 8 to 20 days, oftenest 12.

Chickenpox . . . . 10 to 15 days.

Scarlet fever . . . . 1 to 7, oftenest 2 to 4 days.

Measles 7 to 18, usually 14 days.

German measles ... 14 days or more.

Mumps 14 to 21 days.

Whooping-cough . . . 7 to 10 days.

Influenza 1 to 4 days.

Diphtheria 1 to 7 days, usually 2.

Tonsillitis 1 to 3 or 4 days, usually 2.

Poliomyelitis . . . . 3 to 33 days, usually 8 or 9.

The incubation period is of value in enabling us to approximate the time and plaee of infection and to judge correctly of the length of time that suspects should be isolated. After the disease has J»

developed, however, the character and length of the isolation period for the sick will be controlled rather by the degree of the con- tagiousness and the time at which it is ^ gi'eatest or during which it persists. It will therefore be well to summarize briefly our knowledge on those points.

Smallpox is one of the most contagious of diseases, and prior to the introduction of vaccination almost every- body had an attack, usually in childhood, as natural immunity is very rare. It is probably contagious from an early stage, and it continues so until the patient has recovered from the disease and has ceased to desqua- mate or shed scabs. As showing, however, that it is much more contagious in its early than in its late stages, may be cited the fact that the writer was able to infect

266 THE PREVENTION OF EPIDEMICS

monkeys with the vesicle contents gathered from early skin lesions, never with the scabs or late products of lesions from the same case. The monkey is, of course, naturally much less susceptible to smallpox than is man. The same experiments seemed to indicate that for mon- keys and in the Philippines the contagium is evanes- cent. However, it is reputed to be very persistent and to cling for long periods to infected places or things. Varioloid is a mild form of smallpox, usually seen only in persons who have been vaccinated. It may give rise to virulent forms of the disease if transmitted to more susceptible persons.

ChicJcenpox is probably air-borne from its onset and for three days thereafter.

Scarlet fever is contagious early, possibly more so when the fever is highest, and may continue so after the subsidence of all fever and for some weeks after the disease has apparently ended.

Measles is more contagious than smallpox or scarlet fever, but fortunately the period during which it is so is relatively short. The contagiousness is most marked during the period of onset and probably does not ordi- narily last beyond the second or third day of the erup- tion. The virus is more evanescent than that of scar- latina and neither places nor things retain it long.

The contagium of German measles is probably like that of measles, active for a short time, but not per- sistent.

Mumps is contagious for about two weeks, or a little more, from the time of its onset.

WTiooping-cough is probably contagious during the entire period of its existence, including the early stage before the development of the whoop.

RESPIRATORY TRACT INFECTION 267

Influenza^ likewise, is probably contagious from the onset. It often passes into a chronic stage, wherein the active symptoms have subsided, but a slight cough or some similar reminder persists. As the bacilli remain and may be expelled by the cough, there is reason to think that such cases may remain sources of infection for indefinite periods.

Cerebrospinal meningitis being due to an organism that may be found in healthy noses and throats, but one which possesses only feeble resisting powers, it is impossible to say how long it may be contagious. The degree of contagiousness is not high.

The same is true of infantile paralysis.

Diphtheria is contagious from its onset until such time as the bacilli have disappeared from the breathing passages, a period exceeding the apparent duration of the disease by days, weeks, or months. Different strains of the organisms present decided differences of viru- lence, and this partly accounts for the varying grades of severity shown by epidemics. The virus attaches it- self to the clothing, the bedding, and the room in which the patient has lived, and has in many instances dis- played great tenacity.

Tonsillitis is an inflammation of the tonsils due to any cause. It may, therefore, be diphtheritic, but as generally used and as intended here, the term signifies a tonsillar inflammation due to other organisms than that of diphtheria, and applies to the common " sore- throat " of winter-time. Though neither so dangerous nor so highly contagious as diphtheria, it occasions much discomfort and may spread through a barracks to a considerable extent, especially if the ventilation is poor. Septic sore-throat due to milk has been dis-

268 THE PREVENTION OF EPIDEMICS

cussed. It differs from ordinary tonsillitis in its greater severity and its greater tendency to spread to other structures and to infect the blood-stream and the lym- phatics.

Prevention and Control

The measures of control are general and special. The former include all such measures of hygiene, clean- liness, housing, heating, clothing, and so forth as tend to lessen the dangers of crowding, contact with the sick, poor ventilation, and bodily depression.

Ventilation should at all times be abundant, and it

should be superabundant in the neighborhood of the

sick, as it not only promotes comfort and

health, but dilutes the poison or conta-

gium, and so reduces the dose of it that

those in the neighborhood may inhale.

Water is of only minor importance in the diffusion

of these diseases, but the supply should be good and

special care should be used in disposing of that which

has been used in washing the sick or their effects. It

should be disinfected by chemicals or heat.

The common drinking cup is a source of danger in barracks or in camp, and should be abolished in favor of individual cups or of bubbling fountains that cannot be contaminated by ordinary usage in drinking.

I^oods^ other than milk, are seldom responsible for the spread of the diseases considered ; but food that has been in contact with the sick should be carefully disposed of. The diphtheria bacillus, for instance, might grow on meat, bread, potatoes, or other food-articles.

Persons having any of these diseases should be ex- cluded from kitchens, dining-rooms, and all co^atact

RESPIRATORY TRACT INFECTION 269

with any food except that for their own use and con- sumption. Supplies from bakeries, meat-shops, or other food-distributing places that harbor persons sick of these diseases, are best avoided. It is conceivable that they may occasionally be transmitted by means of food that has been exposed for sale in places where it might be contaminated by infected dust or by droplets of spit expelled by coughing persons.

Milk is particularly dangerous as a means of dis- semination of scarlet fever, sore-throat, and diphtheria, and it may possibly act in a similar capacity for others of these diseases. It is certainly the part of wisdom to exclude persons having, or recovering from, or in con- tact with, any of these diseases, from handling milk intended for the use of others. In case of epidemic the milk-supply should be investigated, and steps be taken to prevent infection through it. Pasteurization or boil- ing will make the milk safe if it is protected from sub- sequent contamination.

Vermin should be guarded against as possible dis- seminators, as in measles, scarlet fever, smallpox, and occasionally some of the other diseases considered, the circulating blood may be found infective. Smallpox has been attributed to flea transmission, though the evidence has not been such as to cause the acceptance of the idea by many. Still, it is not at all impossible that this disease may at some time be found to be in- sect-borne. Biting flies are also said to carry infantile paralysis, and the hypothesis is entitled to much respect because of the support found for it in experiments at Harvard and in the epidemiological studies published by the Massachusetts State Board of Health.

It is obvious that houae-fliea might become polluted

270 THE PREVENTION OF EPIDEMICS

from eating or walking over infective excretions and convey the germs to other persons or to food-articles.

Animals, such as dogs, cats, and other pets, should be excluded from access to the sick for reasons already set forth.

Of special measures of protection against these dis- eases the following are probably most important : —

Early diagnosis is absolutely essential for the con- trol of most of them, and is helpful in all. Measles is highly contagious before the eruption ap- ^ pears, and may be widely spread by per-

° ' sons appai*ently suffering from "colds." All suspicious cases should therefore be re- ported to the surgeon for examination as soon as any symptoms present themselves. As stated before, com- pany officers should encourage their men to go on sick report at the first appearance of disease.

Persons in contact with diphtheria should be exam- ined to see if they are carrying the germ in their throats or noses.

Notification of cases is the next step in control. It follows diagnosis naturally in the case of soldiers re- porting to the surgeon ; but occasionally officers or their families, or more rarely en- listed men, consult civilian physicians. In such instances the presence of contagious disease may not be notified and may escape official recognition, with the consequence that preventive measures may not be adopted. Line officers, enlisted men, and civilian phy- sicians, all should realize that the highest function of the medical officer is the prevention of disease, and that they are preventing his performance of it, as well as violating orders, when they do not promptly report to

RESPIRATORY TRACT INFECTION 271

him any cases of contagious disease in the post with which they may be concerned. Unless agreeing to act thus fairly, civilian physicians should not be allowed to practice on a military reservation, and they cannot properly do so ; and officers and men who through care- lessness or design are responsible for the presence of such diseases on the post being unknown, should be punished.

Notification of the presence of any of the diseases in this group should at once lead to an investigation of its source, with the object of removing this m^ar' if possible. The nature of the investigation -, will be indicated by what has been said as to methods of infection and incubation periods.

The sick should be isolated as soon as the diagnosis is made or suspected. The character and duration of the isolation will vary with the disease. It .

should in all cases be sufficiently strict to prevent all unnecessary contact with the sick, and should last until the dangerous period is safely past.

There can now be little doubt that much of the benefit that results from isolation is due to lessened oppor- tunities for contact with the patient or his secretions. Much therefore depends on having the nurse isolated also, or having him so thoroughly drilled in freeing his person from the germs and in avoiding contact with them as to reduce the chances of mediate contact through him to a minimum.

Smallpox should be isolated at some distance from dwelling or gathering places, even at the expense of some inconvenience. In military life tents make suit- able isolation hospitals unless the weather is unusually severe. The possibility of apparently well persons acting

272 THE PREVENTION OF EPIDEMICS

as carriers must be borne in mind. Diphtheria patients and their attendants must not be released from isolation until their respiratory passages are free from germs, scarlet fever patients until all discharges from the throat, nose, and ears have ceased, and the individual has been well a month or more. In all instances the character and duration of isolation are matters to be determined by the medical officer. Men breaking isolation bounds should be severely punished, as they may expose their comrades to grave danger. Persons known to be ex- posed to these diseases may properly be isolated, or at least kept under stnct surveillance, for a time equal to the maximum period of incubation. Those suspected of having any of them should be isolated until the diag- nosis is definitely established in the negative.

Everything that has been contaminated by the use, _ . . , association, or proximity of the sick should

^ be disinfected before being allowed to pass

non • i. -i. J- 1

again to its ordinary place.

The sick person and his attendants should be well bathed before coming out of isolation, and the bath should be followed in the case of smallpox, scarlet fever, or diphtheria by a washing with an antiseptic solution. Clean clothing should then be put on. Animals that have been in the sick-room should be similarly treated. Cloth- ing and bedding may be disinfected by boiling, steam- ing, soaking in an antiseptic solution, or with formalin. The last named method is less reliable than the others. Houses^ and especially the room occupied by the sick person, and its furniture, should be scrubbed, sunned, and aired. The belief that fumigation and other house disinfection is unnecessary is growing, and experience based on the belief indicates that those measures may

RESPIRATORY TRACT INFECTION 273

usually be ignored with safety. Sunlight, cleanliness, time, drying, and fresh air do the work. Utensils may be boiled, steamed, or washed in antiseptics, while letters, books, and similar articles may be sterilized with forma- lin if they have been in contact with the patient. The discharges of the patient should be mixed with formalin or carbolic solution and allowed to stand an hour before being thrown out. The sputum should receivie particular care, as it carries the contagium of most if not all of these diseases. The patient should only spit into vessels containing antiseptic solution, and even then it is safer if the spit be burned. Handkerchiefs and cloths used to wipe the mouth or nose should be burned or boiled. The use of paper handkerchiefs by all sick persons would be a wise and useful measure. Surgical dressings should be burned.

The most efficient measure for the prevention of smallpox is the induction of acquired immunity through vaccination. The government very properly _ , , demands that every recruit shall be vac- _ cinuted, but occasionally the inoculation . does not " take " on a susceptible man, and through a combination of circumstances he may escape its repetition. In civil life there is a considerable agi- tation against the use of vaccination, the agitators alleg- ing that it does not protect against smallpox, that it is an invasion of personal rights, and indulging in several other incorrect statements. It is not purposed to discuss the matter at length here, but it may be stated that the evidence that vaccination does protect against smallpox is overwhelming, and a belief to the contrary, however honest and earnest it may be, cannot justify any one in endangering the efficiency and safety of an army by its

274 THE PREVENTION OF EPIDEMICS

neglect, any more than can a belief that every man is born with a right to smallpox if he wants it. Any oflBcer or man who in any way interferes with the complete and thorough vaccination of the army makes a great mis- take and commits a grave offense.

The spread of diphtheria may be partly controlled by the use of antitoxin. This may be and is very gener- ally used in the treatment of those sick with the disease, but it is also of value when used as a preventive mea- sure. It is then injected in relatively small doses into persons brought into contact with the disease. So used, it greatly lessens the liability to infection, and to se- verity in case infection does occur. However, because of the possibility of rendering the individual suscep- tible to anaphylaxis in case of necessity for using the serum at a much later date, it is preferable to prevent diphtheria by other means, if possible. Vaccinations and the use of preventive injections of antitoxin have not yet proved of value in protecting from the other members of this group, though they may later be found applicable in some instances.

CHAPTER XIV

INSECT-BORNE DISEASES

The principal human diseases now known to be insect- borne are malaria, yellow fever, filariasis, and dengue, carried by mosquitoes ; sleeping sickness, carried by tsetse flies ; plague, carried by fleas ; spotted fever in Montana and the relapsing fever of central Africa, carried by ticks ; typhus fever and relapsing fever of most parts of the world, carried by lice ; river fever or tsutsugainushi disease of Japan, carried by a small red mite ; sand-fly fever or three-day fever of the Balkans and other parts, carried by sand-flies ; Chagas' disease in Brazil, carried by the "barbiero," Lamus megistus; and kala-azar, which is almost certainly insect-borne, though it is not yet quite determined what insect is the carrier, the bedbug being accused in India and the flea in the Mediterranean countries. Leprosy, smallpox, pol- iomyelitis, pellagra, and a number of other human dis- eases have been attributed by various writers to insect carriage, but the proof adduced has not been such as to carry conviction to the majority of workers. Very many diseases of animals are insect-borne, among them some of the most widely spreading and fatal. Both animals and man are subject to infestation with the larvae of flies that deposit their eggs on the mucous membranes, under the skin, or in wounds of their hosts. The screw worm is an example of this.

The diseases named above will be considered in groups made to conform to the insects carrying them.

276 THE PREVENTION OF EPIDEMICS

MOSQUITO-BORNE DISEASES

The most widespread and common of these is mala- ria. It prevails in most tropical and sub-tropical coun- -j , . tries, and in some of them it produces a great mortality, while it causes much suf- fering, weakness, and loss of time, even where it is less fatal It is an important cause of sickness in our army in many parts of our own country, as well as in Cuba, Porto Kico, the Philippines, and the Isthmus of Panama.

Since the beginning of the Spanish-American War the knowledge of the methods of control of this dis- ease has increased so rapidly that it has now become possible for us to make healthy communities out of places formerly notorious for the certainty and speed with which newcomers sickened or died from malaria, though it must be admitted that the accomplishment of such a result is both difficult and expensive.

As stated in a previous chapter, there are at least three varieties of this disease which differ because the para- sites causing them do so, and which manifest themselves in paroxysms of chill, fever, and sweat, that come at twenty-four, forty-eight, or seventy-two-hour intervals. This regularity of manifestation is only shown, how- ever, in cases of uncomplicated single infections. Owing to multiple infections or complicating circumstances, any one of these types of malaria may show extreme irregularity and may be mistaken for other diseases, the diagnosis being made possible only by examination of the blood, and, at times, with great difficulty. The fever may be continuous and the general symptoms such as to make the disease appear much like typhoid.

INSECT-BORNE DISEASES 277

Or it may be manifested as a neuralgia, as a sudden attack resembling apoplexy, as anaemia, or in other obscure ways. This disease also exhibits periods of la- tency, during which the parasite is present in the body, but in such numbers or under such control by the body forces, that no signs or symptoms are present. When, however, the vital forces are reduced, as by exposure, overwork, alcoholism, or other disease, the parasites gain the ascendency and the disease may manifest itself in a severe manner. Many natives of highly ma- larious regions may be partly immune and show no symptoms even when harboring very severe infections.

Whatever the character of its manifestation, how- ever, the infection is always received through the bite of a mosquito. Many officers from time to time express views to the contrary, usually basing them on their own faulty observations. Occasionally there is reason to suspect that the views are exploited to account for the presence of malaria when the efforts to prevent mos- quito-transmission entail an inconvenient amount of trouble. The fact is that malaria has been investigated with a thoroughness that has been accorded to few other diseases, and the method of mosquito-transmission has been abundantly proved, and no other appears even probable. " If, after they have imbibed malarial blood, certain species of mosquitoes be dissected at serial in- tervals, the evolution of the malaria parasite can be followed in their tissues, until, finally, the germs of the parasite can be tracked into the cells and secretions of the salivary glands of the insect.

" If after a week, or thereabouts, a similarly fed mos- quito bites a hitherto uninfected man, in many instances, after a few days, that man will exhibit the clinical

278 THE PREVENTION OF EPIDEMICS

phenomena of malaria infection and the characteristic parasite in his blood.

" A non-immune, if effectually protected against mos- quito bite, will not contract malarial disease, however long he may live in highly malarious localities.

" Most observers are now of the opinion that the ma- laria parasite, under natural conditions, can be acquired by man only through the bite of the mosquito ; that the mosquito can acquire the parasite only by ingesting the blood of a malaria- infected man, or possibly other mammal ; that there is no extra-corporeal life other than that described ; that there is no authentic instance of malaria being acquired in uninhabited places ; that in the case of malaria in connection with soil disturbances, it depends on the creation during digging operation of puddles of water in which mosquitoes breed ; and that its epidemic occurrence under these circumstances is owing to unhygienic conditions such as usually prevail when large bodies of men, some of whom may bring the infection with them, are brought together on public works attended with extensive earth-cutting, as in rail- way, road, or canal-making."

Several species of mosquitoes are capable of trans- mitting the disease, but they all, so far as now known, belong to the sub-family Anophelinoe. The -_ . , features by means of which these various . species may be identified cannot be dis- ^ cussed here, and positive identification is a

labor necessitating some time and effort even on the part of the specialist ; but a popular rough method of identifying anopheline mosquitoes in general is that the adults, when at rest, stand with their bodies almost or quite at a right angle with the surface on which they

INSECT-BORNE DISEASES 279

are resting, while commoner species rest with the body more nearly parallel to the supporting surface. The larvae, or " wigglers," of the former class, on the other hand, rest with their bodies like floating sticks, parallel to the surface of the water in which they are swim- ming. The more common varieties have theirs more nearly at a right angle to it. These mosquitoes bite principally at night.

Yellow fever is an acute and very fatal disease that occurs principally in tropical and sub-tropical America, though epidemics also occur on the west ■«»■ ii coast of Africa, where the disease was pos- _, sibly introduced by slave-traders. It has appeared in epidemic form as far north as Philadelphia.

Until after the American occupation of Cuba and the subsequent work of the board of army medical offi- cers, under the presidency of Major Walter -lur ^.i, j Reed, the method of infection was un- , _^

known, and water, contact, fomites, poor . .

police, and atmospheric conditions were all credited as means. That Board cleaned up all obscure questions as to the manner of transmission, and estab- lished beyond dispute the fact that yellow fever is trans- mitted by the bite of infected mosquitoes of the species Stegomyiafasciata.^ It cannot be transmitted by water, food, fomites, air, or contact, nor is its spread influenced by poor policing, except as the latter promotes the breed- ing of mosquitoes. The beautiful reasoning and experi- ments which served to establish our knowledge of the means of transmission also cleared up many hitherto obscure points about the disease, and, better still, led to the use of anti-mosquito measures that resulted in its ^ Since known as Stegomyia calopus and as ^de$ calopus.

280 THE PREVENTION OF EPIDEMICS

eradication from Havana, and later from New Orleans, the Canal Zone, and other regions. This constituted one of the greatest sanitary advances that the world has ever seen, one making possible the rejuvenation of Cuba, the construction of the Panama Canal, and, it is hoped, the civilization and development of all tropical America ; and it is well that army officers should keep in mind that all of these things were made possible by the fact that there happened to be in command, in Havana, a line officer who had a knowledge and an appreciation of the importance of military hygiene.

The Board of which Major Reed was the head showed that contact, fecal contamination, handling of fomites, breathing the close air breathed by yellow-fever pa- tients in poorly ventilated places, and all such things, were incapable of transmitting the disease, but that the bite of some infected mosquitoes would be followed by the fever in from three to five days, or occasionally longer. This is the ordinary incubation- period in man, and accounts for the fact f , that non-immunes may develop the disease

so short a time after arrival in places where the disease prevails. But there is also an incubation-period in the mosquito, as shown by the fact that it cannot transmit the disease until twelve days after it has imbibed the infection with the blood of a sick per- son. This accounts for the half-month elapsing between the arrival in an uninfected place of a case of yellow fever and the appearance of the first case of the subse- quent epidemic. This double incubation period, three days for a case in an already infected district, and fifteen or more days for secondary cases in previously non-in- fected districts, is thus clearly explained.

INSECT-BORNE DISEASES 281

Not nearly all mosquitoes biting yellow-fever patients are capable of transmitting the disease even after twelve days, and the Board showed that this was because of the short period during which the yellow-fever patient is infectious. Unless it bites him during his first three days of sickness, the insect obtains no infection and can transmit none. It was also demonstrated that the cause of the disease is in the blood, that it passes through very fine filters, and is probably too small to be seen with our microscopes, and that it may persist in infected mosquitoes for weeks or months.

" These experiments fully explain, Ist, the impunity with which a yellow-fever patient can be visited by a non-immune if outside the endemic area : the mosquitoes in the vicinity are not infective. 2d, the danger of visiting the endemic area, especially at night : the mos- quitoes there are infective and active. 3d, tlie discrep- ancy between the incubation-period, three to five days, of the disease, and the incubation-period, fifteen days and over, of an epidemic: the necessary evolution of the germ in the mosquitoes infected by the original introducing patient demanding the space of time indi- cated by the difference between these two periods. 4th, the clinging of yellow-fever infection to ships, buildings, and localities : the persistence of the germ in infected mosquitoes which are known to be capable of surviving for five months, and probably longer, after feeding on blood. 6th, the high atmospheric temperature required for epidemic extension of yellow fever : such tempera- ture favors the activities and propagation of the mos- quito, and is probably necessary for the evolution of the germ also in the mosquito."

The mosquito that transmits yellow fever is a very

282 THE PREVENTION OF EPIDEMICS

common one in all those parts of America that show _, the disease. A closely allied or identical

_ .- speciesis abundant in the Philippine Islands.

_, Whether or not this Philippine variety is

-_ capable of transmitting the disease is not

positively known, but if it can do so the in- troduction of the disease into those islands, a thing quite possible after the opening of the Panama Canal, might prove a disaster of the first magnitude and a great addition to their already numerous afflic- tions. However, yellow fever is so thoroughly under control in Panama and other points from which ships are apt to go to the East, and the method of its control is so well understood and the journey so long, that the chances of such introduction are considered remote.

The mosquito concerned is a small black one, with white or silvery lines and bands on the thorax and legs. There is a peculiar lyre-shaped figure on the back of the thorax which, together with the white bands on its legs, makes a rough diagnosis of species possible. The insects particularly prefer low-lying shores, but may be found in other places. They are essentially house-lovers, are active biters, silent and very quick, so that they are harder to catch than other varieties. They breed in small ar- tificial collections of water, such as barrels, puddles, cisterns, and partially filled tin cans. " The nature of the water appears to be a matter of indifference : it is found equally in rain or waste water, but more frequently in water discolored by decaying vegetable matter."

Dengue is a disease of very low fatality, but one which

—. may occasion much suffering and anxiety,

and which sometimes occurs in widespread

epidemics. The disease causes, on an average, about

INSECT-BORNE DISEASES 283

one week of absence from duty, and if the epidemic involves thirty or forty per cent of a command, a not unusual figure, the strength of the force will be much impaired. It prevails in the West Indies, the Philip- pines, our Southern States, and in most other parts of the tropical and subtropical world. Like yellow fever, it is a disease of hot weather and low lands, that has prevailed as far north as Philadelphia in summer- time. It is transmitted by a very common variety of mosquito, Culex Jatigans, and possibly by other varie- ties, but not by contact, food, drink, air, or fomites. The incubation-period is from three to seven days, usually about four ; the causative organism is contained in the blood, passes through fine filters, and is probably too small to be seen with the microscope. The disease resembles yellow fever in man}^ respects, and has often been confused with it in America.

Filariasis is infestation with any one of several varie- ties of filaria, or hair-worm, whose young circulate in the blood. It is thought to be related to _,.. . elephantiasis, but was suffit;iently discussed in a preceding chapter. The parasites are introduced through the bites of mosquitoes, one of the most com- mon and widespread species, Culex fatigans, acting as a carrier for at least two varieties. The insect bites both by day and by night.

The prevention of these mosquito-borne diseases rests entirely upon our ability to protect against the bites of infected insects, except in the case of mala- ria, in which we can derive aid from the administration of quinine. Our success then _, ^ depends on anti-mosquito measures, and it is necessary to discuss these briefly. Mosquitoes breed

284 THE PREVENTION OF EPIDEMICS

only in water, the young being as much dependent on that fluid as are fish or tadpoles. The Culex^ or com- mon mosquito, which transmits dengue and filaria, and the Stegomyia^ or striped mosquito, which carries yellow fever, generally breed in vessels of water, cisterns, or drains. The Anopheles^ or malarial mosquitoes, breed "mostly in shallow puddles on the ground, in small ponds, in slow and small runnels of water, in pools of rain water, on rocks, on the margin of slow-running streams, and sometimes, but rarely, in vessels of water."

It must be borne in mind, though, that the Stego- myia is really the only one of the mosquitoes known to carry disease that is so fixed in its habits as to make its extermination relatively easy. This mosquito is practically banished from the Canal Zone, though still found in the adjacent city of Panama, and in the Zone very little work is required to keep free from it. The work against Culex and Anopheles^ however, is con- stant, hard, expensive, almost endless, and distinctly less successful in its results. These mosquitoes, as repre- sented by their various species, can manage to find favor- able conditions in the Canal Zone at all times of the year, and in almost all kinds of water, including a mixture that contains a large amount of sea-water. In fact, the largest and most annoying flights of mos- quitoes seen on the Zone have always come from the hydraulic filling of fresh water swamps with salt water material, that is, with mud pumped from under salt water. At Gatun, Toro Point, Cristobal, Panama, and other places this has been the case.

The larvae or wigglers of all kinds of mosquitoes re- quire at least six or seven days of life in water before they can develop into winged insects, and the time is

INSECT-BORNE DISEASES 285

usually longer, especially if the weather be cool or con- ditions otherwise unfavorable. Drying kills them and also destroys mosquito eggs. On the other hand, natural degrees of heat and cold do not necessarily destroy them if they remain in water, and in northern latitudes both larvae and adults may survive several freezings during a winter and again become active when warm weather returns. Usually only female mosquitoes suck blood, and they do so because the rich nutriment hastens the ripening of their eggs, and these are generally deposited only after such a meal. As the mosquito fills herself to a degree that greatly increases her bulk and weight, and makes flight laborious and slow, she usually seeks a place near at hand in which to deposit her eggs. Partly for this reason it follows that most infested houses or localities breed their own mosquitoes.

It has been demonstrated in the Canal Zone that Anopheles can and on occasion do fly more than a mile from their place of breeding. The occasions for such flights are, in the writer's opinion, limited to such as present the following circumstances ; a large area where the conditions for breeding are unusually favorable, such as one of the salt hydraulic fills mentioned above, an enormous amount of breeding in such an area, lack of abundant human blood for food in the neighborhood of the breeding place, the presence of abundance of food (a town) at a distance of a mile. Were there an- other town within two hundred yards, or a quarter or a half of a mile, the chances are that the town a mile away would scarcely notice any change in the number of mosquitoes. In fact, such has been the experience at several places on the Isthmus. The conditions favored a big flight, but a human barrier in the neighborhood

286 THE PREVENTION OF EPIDEMICS

served to check it and to make the increase of mosqui- toes a merely local one. In ordinary sanitary practice, and not considering such exceptionally large and favor- able breeding places, the control of all breeding within four hundred yards of towns, posts, and houses serves to make them fairly comfortable and safe places of resi- dence. But even this much is no small task in the trop- ics. The Anopheles^ like the Stegomyia^ appears to be a man-lover, though, unlike it, not a house breeder. Practically always breeding in the open, in what might be considered natural, though often actually artificial, collections of water, and almost never in cans, barrels, cisterns, and like containers, it is nevertheless usually found fairly close to human habitations ; and many lo- calities in the Canal Zone that formerly, when towns were near, bred great numbers of Anopheles^ now, since the areas in question have been depopulated, breed almost none. "Mosquitoes, especially Anopheles, love thick undergrowth."

The facts above stated indicate the steps to be taken in warring against them, and of these, destruction of

breeding-places in or near camps, habita- , tions, towns, and garrisons is probably the

most important. The measures designed to ° attain this end are numerous. Drainage by

ditches or by subsoil tile, reclamation of swamp lands, opening fresh water or brackish swamps to salt water tides so as to convert them to salt water marshes and flood them daily with strong sea water, i\xejUling of pools, puddles, hollows, and marshes, the building of dikes and embankments to create lahes in- stead of marshes and to protect dry lands from flooding, the clearing of the banks of lakes and streams from

INSECT-BORNE DISEASES 287

brush and grass and cutting them steep and deep so as to permit and favor wave action^ the cleaning^ straightening^ and narrowing of sti-eams to give them a more rapid flow, are some of the general measures that can be profitably employed in the vicinity of towu« or of permanent garrisons. Each of these measures may be very expensive as to first cost, yet each may prove a highly profitable investment. A few specific instances may be cited from the Canal Zone. Drain- age by ditch and tile has been used in and about every town in the Zone, and has always given good results and done away with breeding places. Opening fresh water swamps to tidal wash has done away with large areas of breeding at Mindi Island near Cristobal. The filling of swamps and low lands, often done as a mere matter of convenient disposal of soil, has made dry many former breeding places. Even the hydraulic fills that have been mentioned as giving rise to excessive breed- ing, only do so for a period of months, and after they have dried out they may leave fine sites for town exten- sion, as at Ancon and Balboa. The building of dikes and the creation of lakes have done good by deepening the water, as mosquitoes rarely breed in water more than two or three feet deep, and by creating more favor- able conditions for fish and for wave motion, both of which destroy larvas. A small lake at Pedro Miguel, which long produced large numbers of mosquitoes and caused the expenditure of much money and labor on its treatment, was rendered harmless and self-caring by the expedient of cutting its banks at an angle of one or one and a half to a depth of a foot and a half above and the same below its general level, and freeing them of vegetation. This allowed the small fish and the wave

28S THE PREVENTION OF EPIDEMICS

action to get at and destroy the larvae that formerly found shelter from both in the vegetation growing in shallow water along shore. The clearing and straighten- ing of streams, " training " them to run rapidly and strongly and to flush themselves well, act similarly. Cleaning bodies of water of vegetation is at times a moat useful expedient, as mosquitoes breed in water- liolding leaves, such as those of the water " cabbage " and the water hyacinth, while other vegetation, such as Para grass and algae, offer shelter wherein the larvae find protection from fish.

But efforts must not be confined to such large under- takings, because the chances are that less ambitious projects, carried out in or about the dwelling, may ac- complish almost as much good, and it will be manifested H)ore promptly. Such local measures will include the filling of small hollows in the yard or about the house, or cutting such outlets from them that they will empty quickly after rains, filling or preventing the form- ation of pockets or pools at the outlets of drains or under faucets, filling, emptying, or obliterating hoof- tracks, wagon-ruts, and similar small depressions, seeing that fire-buckets, fountains, drip-pans under ice-chests and similar water containers are emptied twice a week, and alllarvaB contained in them killed. Empty or partly empty bottles, boxes, tin cans, tubs, and flower-pots must be removed or placed in such positions or conditions that they will not catch and hold water. Useless joints or sections of bamboo must be removed, and pieces that are in use or that form parts of buildings should, if open, he bored at the lowest level of the joint so as to let all water run out. The water in tins or saucers under table- legs or elsewhere as a protectioii from ants should be

INSECT-BORNE DISEASES 289

kept olean and free from larvae. It would be well to have such things filled with antiseptic solution rather than plain water. Sagging eave-troughs and drain-pipes and catch-basins, that do not empty promptly, may afford breeding-places, and should therefore be made right. Banana plants afford quite sufficiently large receptacles for breeding water at the points where the leaves di- verge from the main stalk, and trees may provide them in knot-holes. It may be stated, however, that breed- ing in banana plants is less common than is generally thought. All such places must be investigated and faults corrected. Irrigating ditches should run freely and with a good current when in use, and should drain dry at other times. They should not present stagnant pools at any time. Thick underbrush and high grass should be cut and cleared awa}^ as it not only shelters and harbors the grown mosquitoes, but hides and pre- serves small collections of water and keeps them from drying. Cisterns, shallow wells, rain-barrels, and other large useful containers of water should be screened or tightly covered so that mosquitoes cannot gain access to them. Privies and cesspools should likewise be pro- tected by netting or tight covers, so as to keep them free from the insects, and drain outlets should empty on smootii rocks, or be otherwise so arranged that pools and puddles are not formed by their discharge. Other precautions may be necessary and the circumstances may suggest them. The object to be kept in mind is the doing away witb all stagnant water.

Many of the measures outlined above, such as drain- ing pools and emptying fire-buckets, are destructive of larvae in that they allow these to dry. In some in- stances, however, it is not possible to do those things,

290 THE PREVENTION OF EPIDEMICS

and other methods of destroying larvsB must be resorted _ to. Mosquito larvae, like all other living

^ , creatures, have their natural enemies, and

_ these may be utilized. Many varieties of

small J?6"^ devour them, and some of these, for instance the '* millions " of Barbados, are said to do the work so thoroughly as to quite prevent mosquito development in ponds stocked with them. Many va- rieties of fish are useful for this purpose, and ponds, streams, and marshes that create mosquito nuisances can be profitably stocked with them. Other water ani- mals, such as tadpoles and some kinds of beetles, are also reported to be destructive of larvae. The larvae of dragon flies are certainly so, but as regards the tad- poles and beetles the writer cannot speak from personal knowledge. Ducks, especially mallards, are said to be very destructive to mosquito larvae.

Moulds and other germs may also attack the larvae and cause their death through disease. Such factors often make the task of artificially rearing mosquitoes for experimental work one of some difficulty, but, so far as known, they have not been used to reduce their natural occurrence. That the natural enemies are not alone sufficient to destroy all larvae is evident from the fact that the latter are occasionally numerous in waters abounding with fish and tadpoles.

Chemical 2)oisons may also be used, but they are dan- gerous and can only be applied to waters which are not needed and which should, therefore, be drained away or otherwise disposed of.

Very extensive use has been made in the Canal Zone of a preparation known as larvacide. It has been of very great value in many places, but is not now used so ex-

INSECT-BORNE DISEASES 291

tenslvely as formerly because the cost of it has increased so greatly. It is made as follows : Crude carbolic acid of a specific gravity not above 0.97 and containing fif- teen per cent of tar acids is heated. Into 150 gallons of this 200 pounds of crushed and sifted common rosin are stirred, and then 30 pounds of caustic soda dissolved in six gallons of water. These amounts yield three and a half barrels of larvacide, which for use is diluted with four or more parts of water. It kills mosquito larvae in five minutes in a dilution of 1 to 5000.

Oil, preferably crude petroleum, is much used as a means of destroying larvae. It acts mechanically. The larvae, though living in water, are air-breathers, and must come to the surface at intervals of a minute or so for that purpose. They breathe through a STnall pipe or tube which rises above the back near the tail, and which is projected from the surface of the water when air is to be taken in. If the water be covered with a film of oil, this little tube becomes clogged with the latter as it passes through it, and respiration is hindered or pre- vented so that the wiggler dies of suffocation. Other oils will answer as well, but crude petroleum, because of its cheapness, harmlessness in the amounts used, and its slow evaporation, is preferred. Refined kerosene spreads more rapidly and evenly, but it also evaporates more readily. Some crude petroleums, especially such as contain a considerable asphalt base, as do California oils, will not spread well if applied to water without any diluent. They are likewise too thick to be pumped readily with small (knapsack) pumps or to drop relia- bly from drip cans or barrels. It has therefore been the practice in the Canal Zone to " cut " this heavy oil with larvacide or kerosene, of which enough is added and

292 THE PREVENTION OF EPIDEMICS

mixed in to overcome the faults mentioned. The amount of either required will vary from two to twenty per cent, both amount and choice of diluent being deter- mined by circumstances. At the present writing larva- cide costs two and a half times as much as kerosene, and the latter is therefore ordinarily preferred as a diluent of crude oil, though special cii-cumstances make the former preferable occasionally. The oil may be ap- plied by sprinkling, spraying, or "painting " it over the surface. In the last-named method it is applied by means of a saturated rag on a pole that is rubbed or brushed about on top of the water. So long as the surface is well covered the method of application does not matter. The applications should be renewed as necessary, and the frequency of this will depend on several factors that must be taken into consideration. A slight current or a prevailing wind may drive ail of the oil to one side of a pond or may remove it in a short time. In such cases the renewal must be more frequent, and must be on the side from which the oil flows. Light oils of course re- quire more frequent renewal than the heavier ones that do not evaporate so readily. The surface of the water should not be left uncovered for more than three or four days. For oiling running streams, small springs, drainage ditches, and similar water runs, use may prof- itably be made of drip cans or barrels. These may be made from oil barrels, cans, or other receptacles. There are many ways of arranging the drip, and the officer or man in charge can devise one readily. A spigot may be used, or a hole made in the receptacle may be stopped with a plug having a small groove cut in one side, or with one having a larger groove filled with wieking or cotton waste, the idea being to have a drop fall often

INSECT-BORNE DISEASES 293

enough to keep the water covered with a thin coat of oil. In order to make the drop break and spread when it strikes the water the receptacle should be raised two or three feet above the water level. Small wet places caused by a seepage of water from a hillside or else- where may be easily and profitably oiled by pegging down at the upper edges of the seepage area small bundles (a handful) of cotton waste saturated with oil. These should be renewed about once in two weeks, as by that time they are apt to be hard and to give oS. an insufficient amount of oil. Another useful, simple, and successful measure of treating such seepage areas is to concentrate the moisture into tiles or ditches and then oil it if necessary.

If water be drawn off through a pipe running well under the surface, oiling does not injure it for house- hold uses and is therefore applicable to cisterns, raiii- barrels, and other domestic supplies.

Small collections of larvae-containing water can be easily emptied by sweeping or other means, and the larvae promptly die. It is said that the common prickly pear cactus of the tropics can also be used in destroy- ing larvae. " The thick, fleshy leaves contain a muci- lage which exudes when the leaves are chopped and added to water, the mucilage rising to the surface and forming a practically air-tight covering similar to that formed by oil."

Under ideal conditions mosquitoes should not reach

adult life where an active anti-mosquito ^

. , . -1 TT J • Destnic-

eampaign IS being carried on. Under possi- ble conditions some are almost certain to do « , , so, and under the best conditions obtaina- ble at a reasonable cost a good many are apt to be found.

294 THE PREVENTION OF EPIDEMICS

It often happens too that a camp is to be maintained at a place for so short a time, or a given piece of con- struction work is so small and so unfavorably located, as to make adequate measures against breeding and larvaB far too expensive in money and labor to be prac- ticable or worth while. In such circumstances the de- struction of adult mosquitoes may be the only available means of getting rid of them. The method is especially applicable in ridding houses of mosquitoes that have bitten yellow fever patients. The house may be closed and sealed and then fumigated with sulphur, the vapor of a mixture of camphor and carbolic, or with the fumes of pyrethrum. The first two kill the mosquitoes, but the pyrethrum may only stupefy them, so it is necessary to gather them up and burn them. As an antimalarial measure, fumigation, because it cannot be continued daily and because of the cumbersomeness of the proc- ess, is of less value than hand catching, which may take the form of "swatting" or may be better accom- plished by the use of a tube or wide-mouthed bottle containing a chloroform-saturated pad. This is best pre- pared by taking a neckless vial one inch in diameter and five or six inches deep, filling it for an inch with cut rubber bands, and placing over these a disk of blot- ting paper. Then pour in one or two teaspoonfuls of chloroform and allow it to be taken up by the rubber. When this tube is placed and held over a resting mos- quito, as it may readily be, the latter drops inert in a few seconds. To aid in finding the mosquitoes in a dark room or barrack a small electric seai-chlight or acety- lene lamp is most useful, and greatly aids in making the catch thorough. With it mosquitoes may be found in dark corners, behind doors, and on articles of clothing,

INSECT-BOUNE DISEASES 295

along baseboards and mouldings, and in other places where they might not be detected otherwise.

Certain measures have value as tending to discour- age adult mosquitoes and to cause their abandonment of a neighborhood, even though not killing them. The most important of these are the removal of stagnant water, in which they may lay their eggs, and the cut- ting and clearing of underbrush, high grass, and vines, on or in which they take shelter and rest when not busy. Smoking and anointing the hands and face with certain volatile oils are advocated as measures of per- sonal protection for the same purpose, but they are not to be relied upon. A hungry mosquito will bite through a layer of oil, and the most enthusiastic smoker cannot produce such clouds as to protect his ankles, bands, the back of his neck, and other parts.

The more effective method of protection from adults

is in the use of screening materials, either of wire or

of soft fabrics. Houses with wire-screened _, .

Protec- windows and doors are in general use ^ ,

throughout our country, and add enor- . , . mously to the comfort and safety of life in the hot season. They have a very great influence in the prevention of all mosquito-borne diseases. In order that full benefit may be realized from screening it is impor- tant that the material be kept in good condition, holes patched as soon as found, doors provided with good springs, cracks in floors and openings under the corru- gations of iron roofing stopped, and all necessary mea- sures taken to insure the complete exclusion of mosqui- toes. For this purpose it is necessary to have buildings and screens inspected frequently, and repairs made as needed.

296 THE PREVENTION OF EPIDEMICS

Bed-nets are in general use throughout all barracks in the tropics, and, if in good condition and properly cared for, they offer adequate protection during sleep- ing hours, unless the sleeper rolls or tosses in such a way as to bring part of his person against the net, in which event the insects feed through it. It is neither pleasant nor practicable to spend all of the day, or even most of it in bed, and bed-nets are therefore inadequate.

Head-nets are at times of value for night use in cam- paign, and rarely so for common use in the daytime. Most mosquitoes, though, do not bite out of doors in the daytime, especially persons who are in motion.

Adequate clothing is of course important in ])rotect- ing f i-om mosquito bites, and should he used for that ■p tflr purpose. In spite of all precautions an oc- ^ , casional mosquito will manacre to bite the

__ . most careful man. It is therefore impor-

. froTTi ^^^^ ^^ ^^^ ^^^^* *^® insects do not become Infection ^^^^^^-^^ ^^^^ disease, and yellow - fever, dengue, and malaria patients, particularly the first-named, should be kept screened or doubly screened during the entire time that they are capable of giving infection. For this purpose it is essential that all cases be known, and early diagnosis and prompt noti- fication are therefore important, especially in yellow fever, which is so deadly and yet is infectious only in its early stages. In addition to screening, the malarial patient should be taking quinine to free his blood from germs. As natives of malarious regions are very ajit to harbor the parasite in their blood and to keep the mos- quitoes in their neighborhoods infected, it is important to keep them away from barracks and healthy house- holds, and it is wise to build dwellings or barracks at

INSECT-BORNE DISEASES 297

some distance from native towns or habitations. Na- tives working about soldiers' quarters should be re- quired to take quinine regularly and to observe the general rules of hygiene.

Quiniue has been much and successfully used as a preventive of malaria. The most extensive use of it has been by the government in Italy, and ^J j-^ ■ • the Germans in some of their African col- jl onies. It may be said that there are two , . ^" methods of using quinine in prophylaxis, and the difference of opinion concerning the value of this method of control arises from a confusion of them. One method consists in the daily administration of small doses of from two to five grains of quinine. The evidence concerning the value of this method is con- flicting and many instances have been cited to show that it is of little or no use. The other method is the administration of doses that might be therapeutic if the person were actually infected, and it is highly effective in keeping down the disease, by reason of the fact that parasites entering the blood are promptly destroyed, and of the other fact that actually infected persons have their peripheral blood freed from parasites and are therefore not infective for mosquitoes. It is probable that a large part of the Italian and German successes with quinine prophylaxis lay in the fact that it was largely a treatment of malaria carriers. Such treatment alone, if it could be carried out thoroughly every- where, would suffice to eliminate the disease. Like many other desirable measures, this is impracticable. When a command is temporarily placed in a malarious re- gion without other adequate protection, it is advisable to place the whole force on quinine. The most satisfac-

298 THE PREVENTION OF EPIDEMICS

tory dosage is generally about ten grains. This may be given daily, and when it is desired to reduce the total intake of the drug the interval between doses should be lengthened, rather than giving a smaller dose, the idea beiug to have an efficient concentration of quinine in the blood occasionally rather than to have an insufficient amount present at all times. It should be borne in mind that many persons are very susceptible to the action of quinine and are apt to suffer much discomfort from the use of a dose of this size. In such cases the surgeon must decide whether the individual should use the drug as a prophylactic, and, if so, how.

Experience indicates that the work of mosquito " ex- termination " is more effectively done if regular forces __ are kept at it to the exclusion of other work,

and every tropical or mosquito-infected post ^ . , should have such a "mosquito brigade."

Men kept on the work soon learn the lo- cations and habits of the insects and become expert in destruction or prevention. When the work is left to householders or to general fatigue parties, it is usually neglected and the plague continues unabated.

FLEA-BORNE DISEASES

Bubonic plague is the most important disease trans- mitted to man by fleas, and it will be discussed here _. only briefly, as mention has already been

made of it. The disease is due to a small bacillus that is possessed of great vitality, so that the virus may persist for a long time. Extensive investi- gations in different parts of the world, but principally in India, have clearly demonstrated that the disease is usually transmitted in the manner here indicated,

INSECT-BORNE DISEASES 299

though it is occasionally communicated in other ways. The relation of rats to plague epidemics has already been discussed. A Russian observer states that bedbugs also may transmit it. In Java it was found that body lice taken from plague patients contained plague bacilli. It is possible that they might transmit the disease. Pneumonic plague and its transmission by contact and droplet infection have been discussed, and experiments carried out in Manchuria and later in Manila indicate that during coughing, even when no visible droplets are expelled, large numbers of bacilli are widely dissemi- nated, and the wearing of masks, gowns, and eyeglasses by doctors, nurses, and others attending patients with this form of the disease is important. The germs are ex- creted by plague patients in the spit, urine, the pus from ulcers and buboes, and possibly the feces, so that dust- infection and contact may account for some cases. Nev- ertheless the rat and the rat flea are responsible for the majority of cases and epidemics, and the measures of prevention and control are aimed at these two. The following facts, among others, constitute the reasons and justification for such measures.

Rats abound particularly in houses and neighbor- hoods which, because of poor policing or other sani- tary neglect, afford them food, shelter, and -- ., , breeding-places. They are very susceptible , TrtinH to plague and are probably the natural -y.iog4o„ hosts of the disease. When severely in- fected they may have the germs in their blood in enor- mous numbers, as many as 100,000,000 in a cubic centimetre of blood. All rats have fleas, which remain on them imtil death, when they leave them and seek other hosts, usually rats, but in their absence men or

300 THE PREVENTION OF EPIDEMICS

other animals. Fleas breed in the nests of their hosts, live on their blood, and in biting may readily ingest as much blood as may contain, in the case of plague septicemia, 5000 plague bacilli. These bacilli may re- main alive and virulent in the flea's stomach for as long as fifteen days, and then be ejected when the flea bites again, and gain entrance to the wound made by the insect, thus producing infection.

While the rat flea is the insect principally concerned in carrying the disease, dog, cat, and human fleas may _ ., __. act the part. The following is the ordinary

life history of the rat flea in Bombay. The — —,. egga are laid at all seasons, from one to five

at a time, and hatch in about two days. The larvje are wormlike and resemble some small fly and wee- vil larvse. They live on almost any kind of refuse, often on parental excrement, and, after varying periods of not less than one week, spin cocoons of fine, silky thread, which become covered with dust and rubbish and are difficult to distinguish. The adult fleas escape from these cocoons after one or two weeks and seek a host, as they can only live on fluid food, especially blood. The most favorable temperature for breeding is from 50° to 85° F., and when the mean is above or below this range, breeding stops or is delayed, a fact which partly accounts for the seasonal variations of epidemics. Each species of flea has its own host, which it prefers to all others, but in the absence of that host, and after a period of starvation, it will seek others. The rat flea, for instance, will not usually bite man until three days after the death of its rat host.

It is to be noted, however, that the " rat flea " does not mean merely one species of flea. The common rat

INSECT-BORNE DISEASES 301

flea of the Philippines is not the same as the one most common in India and Java. The life history and breed- ing liabits of rat fleas therefore vary on this account and others. In Java, where the climate is very uniform, the mean temperature being from 73 to 75 degrees Fahrenheit all the year and the humidity not less than 70 per cent saturation, flea breeding and plague spread have no seasonal variation as in India and other places. In Java, the eggs of the common rat flea (^. cheopis) hatch in from four to eight days and the larvae develop into mature fleas in thirty-one to fifty-two days. The adults lived, in the laboratory, only two or three weeks. Humidity is favorable to their development, as when the air is driest fewer eggs hatch and both the larval and pu- pal stages are prolonged. Infectious plague bacilli were there found in fleas eighteen days after their ingestion. In the Canal Zone fleas begin to leave the body of a rat almost immediately after its death, and all have left at the end of two hours. The common rat flea of England may have its pupal stage prolonged for months, cold weather so influencing it. In rubbish the adults of this flea will live apparently unfed for as long as seventeen months, without rubbish for one momth. It is said that this flea will feed on man as readily as on rats, but that it does not breed until it has fed on rat blood. In India the laying of eggs, the development of eggs into larvae, of larvae into pupae, and of pupae into adults are all subject to marked seasonal variations, being most active in wet and tem- perate weather and least so under dry and hot con- ditions.

The measures to be taken for the prevention and sup- pression of epidemics are indicated by the facts recorded above. They must embrace numerous and costly expe>

302 THE PREVENTION OF EPIDEMICS

dients unless the fight is begun in earnest at the first _ appearance of cases, and the disease eradi-

^ , cated before it has had an opportunity to

„ spread. Failure to take vigorous action

X eai'ly resulted in the spread of plague „ . through San Francisco, so that the work

J . and expense of fighting it had to be con-

tinued for years. General hygiene is of great importance as lessen- ing the numbers of rats and fleas, both of which abound in the presence of filth. Such measures must include the removal or destruction of rubbish and other material in which the rats hide or make their nests, the stopping of their holes or other means of access to walls, floors, and other hiding-places, the preven- tion of their access to garbage and other ^° food-supplies. They must also include such

cleanliness of persons, domestic animals, houses, streets, and communities, as will make the presence of fleas, bedbugs, and lice improbable.

Special measures should also be adopted against rats, such as their destruction by poisoning, trapping, and disease. The last-named measure is em- ployed by scattering bait contaminated with ° cultures of a bacillus that causes epidemics

among rats, but does not harm man or his domestic animals. The keeping of cats has been advo- cated as a useful anti-plague measure, and it is prob- ably of value. Old and rat-riddled buildings may need to be destroyed. Good buildings should be made rat- proof by means of concrete, cement, and sheet-iron. Stables and warehouses will require particular atten- tion, and their floors, walls, and roofs should be made

INSECT-BORNE DISEASES 303

as rat-proof as possible. Because of the frequency with which rats are transported in ships, all wharves and docks must be freed from them as far as possible, ships from infected ports should be required to anchor off- shore, and all cables or chains leading to shore or to other boats should be provided with shields that rats cannot pass. Sewers should be well flushed to keep them clean, and should be screened or barred so that rats may not pass from them to houses or other build- ings. Houses or boats known to be infested should be tightly closed and fumigated with sulphur fumes or other poisonous gas that will destroy the rats.

The greatest of all anti-rat measures, however, is cleanliness. A city, a house, a wharf, or a ship may be as " rat- proof " as it is possible to make it, and if it is not kept clean and well policed it may swarm with rats, despite traps, cats, and poisons. On the other hand, a building far from rat-proof may be kept free from rats without any of those means. Given rat-proof food storage and garbage cans for kitchens and rat-proof grain bins for stables, and even they can be kept freer from rats than can other similar places with poisons, traps, and cats, but without adequate food protection.

As helpful in fighting rats it may be mentioned that they can climb almost anything, even an iron pipe or a bamboo pole, may burrow as deep as two and a half feet, can jump upward eighteen inches, "can surmount any horizontal projection of less than six inches if the material be such as they can climb on a vertical sur- face, and can walk along a thin suspended wire." A rat released 450 feet from shore reached land in six minutes, and one released 1300 feet from shore swam a total of 1500 feet and reached land in fifty-five minutes.

304 THE PREVENTION OF EPIDEMICS

The interesting fact that during a series of epidem- ics there is evolved a race of rats relatively immune to plague has been observed in India. In plague-free cities (Madras, Raipur, Banda) infected rats show a case mortality varying from 90 to 100 per cent, while in plague-stricken places (Cawnpore, Lucknow, Poona) only 20 to 40 per cent succumb. This immunity is trans- mitted from parent to offspring and is not acquired.

The most important measures against fleas are pro- bably good general policing, the maintenance of clean _- floors, and the absence of litter and waste

in which they may breed ; but other mea-

. sures are also of value, and among them against , .1,1.. 1

_,, may be mentioned the use 01 msect-powder

and antiseptic soaps on domestic animals, the use of foot-covering and other adequate clothing, and the use of petroleum on floors and streets, and of putty, paint, and antiseptic solutions in cracks of floors and walls. The Indian Plague Commission reports that for practical purposes flake naphthalin is the most gen- erally effective agent to use against fleas in all stages of their life cycle. It may ordinarily be used in its dry form, but to get it into cracks and crevices it may be dissolved in benzene. For the treatment of rat holes they advise the use of carbolic emulsion (larvacide is such), or of a soap-petroleum emulsion, to which flake naphthalin has been added. A soap-petroleum emulsion may be made by combining 80 per cent of crude petro- leum with twenty per cent of whale oil soap (or, pre- sumably, other coarse soap). A room thoroughly washed and sprayed with this is said to be freed from fleas. As previously suggested, the use of crude oil in road-mak- ing, as is now much practiced in this country, will pro-

INSECT-BORNE DISEASES 305

bably prove of value in lessening the number of fleas. Fleas may be collected in rooms or houses known to be infected by turning guinea pigs loose in them. The fleas attack the animals, and may then be stupefied with chloroform, combed from the hair, and burned.

Every case of plague in man or rat should be promptly reported, so that proper measures of isolation, fumiga- tion, disinfection, etc., may be instituted early. All rats found dead, as well as those trapped or otherwise captured, should be tagged with a statement of the time and place, and then examined for the presence of plague. If it is found that they have the disease, active measures must be begun at once in the neighborhood from which they came. All persons afflicted should be isolated and their discharges cared for. Disinfection of houses and effects should follow.

Anti-plague vaccination has been considerably used iu India for some time now, and the following state- ments as to results have been published : -TT-e-j-- j» " 1. In a native of India, who is more sus- ^ ceptible to the disease than Africans, Euro- peans, and some other races, the inoculation now in force reduces the liability to attack to less than one third of what it is in a non-inoculated Indian. 2. In the one third of cases which still occur, the recovery rate is at least double that in the non-inoculated attacked. The ulti- mate result is a reduction of plague mortality by some eighty-five per cent. 3. In an inoculated European an attack of plague, if it subsequently occurs, has so far always ended in recovery. 4. The inoculation is appli- cable to persons already infected and incubating plague, and prevents the appearance of symptoms or else miti-

306 THE PREVENTION OP EPIDEMICS

gates the attack." Government reports show that in 1911 there were distributed 1,211,170 doses of plague vaccine, and that among 118,148 vaccinated persons there was a plague incidence of 7.96 cases per 1000, with a case mortality of 39.5 per cent ; while among 321,621 unvaccinated persons the incidence was 34.4 per 1000, with a case mortality of 78.6 per cent, indi- cating results as good as those claimed by the origina- tor of the method and quoted above. Similar results were reported from Java for the same year, yet the statement has been published that the use of vaccine has there been abandoned. The Indian government report just referred to states that the protective power of the vaccine varies with the severity of the reaction it causes.

LOUSE-BORNE DISEASES

Of these typhus and the relapsing fever of most parts of the world have been, in former times, among the world's great scourges, and while often known as jail fever, ship fever, camp fever, and famine fev^r, their appearance was by no means so limited as those names would indicate, and palaces and great persons were not strangers to the diseases or their carriers. At present these diseases are almost unknown in our coun- try, England, Germany, and the other highly civilized Western countries, but in many parts of the world one or both are still rather common, notably in Mexico, where the typhus is known as " tabardilla" in north Africa, in Bussia, in Asia, and especially in China, while a large epidemic of typhus prevails in Japan, es- pecially in Tokio, at the time of this writing.

Brill's disease, of the immigrant sections of some of our cities, is a mild form of typhus.

INSECT-BORNE DISEASES 307

The germ causing typhus has not been identified to the satisfaction of most workers. That causing relaps- ing fever has been known for a longer period than most other germs causing human diseases, and is a spirillum, a motile, corkscrew-shaped organism that is readily detected in the circulating blood at certain periods of the disease.

It has been shown that both of these diseases are or- dinarily conveyed by body lice, but there is also evi- dence that both may be conveyed by head lice, and the investigation of a case of typhus in an American sol- dier in China suggested to the writer that the crab louse might also carry that disease. Typhus is ordinarily transmitted by the bites of the lice, but this is only exceptionally true of relapsing fever, of which disease the insects are contaminative carriers, and in which in- fection usually occurs when the insect is crushed and its juices rubbed into the skin by scratching. There is evidence that both diseases and the power to infect with them may be passed by the lice to their offspring. The following observations on lice are not without in- terest. Body lice are more hardy than head lice and outlive them under adverse conditions. Both survive longest when maintained at a temperature of about 82 degrees Fahrenheit, in a moist atmosphere, and allowed to feed twice daily. ^ Body lice reared in a vial worn next to the body, and allowed to feed twice daily, afforded facilities for the following observations by an English natural- ist. A female lived one month, copulated repeatedly with a male that died on the seventeenth day, and later with another male. She laid 124 eggs in twenty -five days. The eggs hatched in eight days under favorable

308 THE PREVENTION OF EPIDEMICS

conditions, but not at all in the cold. When larvje emerge they feed at once if given an opportunity. They reach the adult stage on the eleventh day, after three moults. The adults begin to copulate five days after the last moult and live about three weeks thereafter. Unfed lice die in five days or less, unfed larvae in thirty- six hours.

The above facts being known, the method of preven- tion of typhus and relapsing fever is obvious, — avoid- _^ ance of lice. To avoid lice, cleanliness of

person, clothing, and associations is neces- sary. To get rid of them, infested clothing should be boiled or steamed, infested bodies washed, infested hair shaved or soaked for fifteen minutes in a solution of one part carbolic in forty parts of water, infested barracks or tents emptied and thoroughly scrubbed and disinfected.

FLY-BORNE DISEASES

In addition to typhoid and other diseases discussed in preceding parts of this book, in which the fly acts as a _. . simple carrier of infection but does not ac-

_. , tually introduce it into the body, the sleep-

ing sickness of Africa is a very important disease. It is introduced by a biting fly, and is caused by a small animal parasite very much like that causing surra in horses in the Philippines and other places.

The only means of prevention yet known are the avoidance of fly bites, the cleaning of undergrowth from near streams, and the avoidance of infected local- ities. The disease has spread widely throughout Africa within a comparatively few years, has caused enormous fatalities, and practically depopulated large districts.

INSECT-BORNE DISEASES 309

All of the European countries having colonies south of the Sahara have done much work and spent much money in their efforts to control it. Whether or not there are two or three kinds of sleeping sickness, caused by two or three species of trypanosomes, is not at pres- ent settled, but at any rate all sleeping sickness is try- panosomiasis and is transmitted by tsetse flies. Afri- can antelope appear to be reservoirs of the disease, and the question of their extermination is being discussed. The value of proper clothing as a protection from fly bites is not to be forgotten. It appears that sleeping sickness is relatively more common among European women in Africa than among the men, a fact probably partly accounted for by the less degree of protection of this sort afforded by the women's clothing, especially by their stockings as compared with the men's leggings or trouser legs.

In the Balkans, in many places in or about the Med- iterranean, in India, and elsewhere, a short, sharp, pain- ful fever, called "three day" or "sand-fly _, fever," has been found to be carried by _ sand flies or midges of the genus Phlehoto- p^ _.. mus^ very small insects that breed in crev- ices of stone walls and similar places. The disease is not fatal and bears a clinical resemblance to dengue. Prevention lies in avoidance of bites, a difficult matter where the flies abound, as they readily pass through most mosquito screening.

TICK-BORNE DISEASES

The most important tick-borne diseases that have been well studied are the African relapsing fever, due

310 THE PREVENTION OF EPIDEMICS

to a spirillum, and the spotted or tick fever of western Montana, due to an unknown organism. The latter dis- ease may affect American troops, as Fort Missoula is in the country in which it occurs. No case has yet appeared in a soldier. Both of these diseases may be transmitted by ticks that have bitten sick persons, or by the young of such ticks. The methods of prevention thus far known to be of value are the avoidance of in- fected districts and of tick bites. In the case of spotted fever the season is short and the danger is slight, except from the first of March to the middle or end of July. If infected regions must be visited, the use of adequate clothing and of head-nets and bed-nets wiU be of value, but probably not absolutely protective. Wood-ticks, such as convey spotted fever, disappear as forests are cleared and the land cultivated. The ticks that convey the African fever abound principally in rest-houses and old camps, and cleanliness, avoidance of old huts and old camp-sites, and the use of nets, would seem the best measures of protection.

DISEASES BORNE BY BEDBUGS

As stated above, a number of diseases have been credited to the agency of these pests, and the evidence incriminating them is sufficiently strong to make their avoidance and destruction a necessity, as well as an aesthetic measure. The mere fact that they are and for an unknown period have been closely parasitic on man is presumptive evidence of the possibility of one or more human diseases having adopted them as carriers, be- cause a study of the insect-borne diseases that have just been discussed shows that each of them is borne by an insect closely associated with the animal host. In

INSECT-BORNE DISEASES 311

most instances in which the carrier is not a parasite especially associated with man himself, for example the rat flea and the tsetse fly, it could reasonably be claimed that man is only accidentally the subject of the diseases, which in the instances cited belong to the rat and the wild game. Bedbugs are so generally recog- nized as vermin and indicators of uncleanliness that their presence constitutes a cause of shame in a well-regulated house or barracks. The avoidance of diseases trans- mitted by them depends on scrupulous cleanliness of houses, beds, and bedding, and the avoidance of those that are not clean. Soldiers, though living in clean sur- roundings, may expose themselves to bites in seeking sexual indulgence or drink, and they should be taught by precept and example not to do so.

CHAPTER XV

VENEREAL DISEASES

The term venereal is usually applied to the diseases resulting from illicit and impure sexual intercourse. The principal members of the group are syphilis, chancroid or soft chancre, and gonorrhoea. In a gen- eral sense the adjective is truly descriptive, but, as stated before, it is not always so, and all of these trou- bles may be contracted by persons absolutely innocent of illicit connections or even of proper intercourse. It is, however, so generally true that in soldiers, at least, the diseases result from improper conduct, that they are assumed to be " not in line of duty," and a report to the contrary requires special explanation.

These diseases are particularly frequent in youth and C* p al ^^^^y manhood, and it is stated that " about — 95 per cent of all cases of gonorrhoea occur

between the ages of sixteen and thirty." The reasons for this are numerous, and some of them may be summarized as follows : —

1. This is the period at which sexual desire and power are at their maximum. After the age of thirty some decline in both has usually begun.

2. It is also a period in which judgment is not ma- tured, self-control not well developed, and ignorance not dissipated, so that the future wife and family ex- ercise no claims and venereal diseases are regarded as trifling.

3. Manhood and virility are synonymous terms, in

VENEREAL DISEASES 313

common usage as well as in the dictionaries, and youth delights in demonstrating its manhood.

4. Most men are married by the time they reach th« age of thirty, and are less apt to be exposed to infec' tion thereafter.

The soldier is probably more apt to contract venereal diseases than the young civilian, because his associates are practically all males ; his topics of conversation are largely such as are only handled in " stag " gatherings ; he is removed from the restraints of the family and of the public opinion that can most influence him, that of his friends and acquaintances at home ; he may at times find it difficult to obtain access to other female society than that of prostitutes, and these are always to be found. He may also drink a bit to demonstrate his man- liness, to relieve his loneliness, to be companionable, or simply because he is " a young man, void of under- standing " ; and then, with judgment perverted and desires inflamed by alcohol, he forgets danger and seeks intercourse where he can most readily obtain it.

For many years our army has had the highest non- effective rate of any army publishing its statistics. The reasons for this were probably several in number, though not all well understood. At present the condition is improving, official reports showing the constantly non- effective rate in the army stationed in the United States to have fallen from 11.44 per 1000 in 1909 to 3.58 per 1000 in 1913.

In his annual report for 1913 the Surgeon General as- cribed this improvement to two main factors: the general use of preventive measures after intercourse, and the stoppage of pay during absence from duty on account of illness due to the soldier's own misconduct.

314 THE PREVENTION OF EPIDEMICS

When to this is added the time lost because of troubles indirectly due to venereal diseases, and the duties poorly performed because of them, it is probably no exaggeration to say that it was almost as though one regiment had been eliminated from the service.

The company officer cannot expect to work a revolu- tion in the morals of his men, or to make chastity a _ . general characteristic of them, but he can

__ exercise some influence in that direction

, _ by his personal conduct and example, by

choosing non-commissioned officers who will probably do the same, by making the soldier's surroundings pleasant and attractive, and en- couraging him to find his amusement and recreation in the post, by providing good reading-matter and help- ing to make the most of the post exchange as a place of recreation and amusement, and by giving his men instruction as to the dangers of venereal disease and the sanity, healthfulness, and safety of sexual control and continence. Recruiting officers can do much by careful selection of men, as it is a well-known fact that the great number of admissions to sick report for venereal disease is made up by a relatively small number of men, the majority of whom are of the less desirable class of soldiers. Drink, poor home -training, ignorance, and lack of self-respect lead these men to places and prac- tices that their more decent comrades avoid.

As man is the only carrier of these diseases, as they are transmitted in nearly all instances by direct physi- cal contact, and as early diagnosis, isolation, and treat- ment enable us to do much in the control of other transmissible diseases, it seems reasonable to believe that similar measures, if generally enforced, would

VENEREAL DISEASES 315

produce great results in these. There can hardly be any doubt that if all cases of venereal disease were promptly reported and then isolated and kept from sexual intercourse until well, the diseases would be ex- terminated. These are such chronic troubles, however, and require such prolonged and careful treatment to insure a cure, that such a plan is quite impracticable. Many efforts have been made to approach it though, by the regular examination of prostitutes and their isolation and " treatment until free from contagious lesions, and similar measures have been adopted in re- gard to soldiers in our own service. But it cannot be said that the diseases have been brought under control by such measures, and the reasons are fairly obvious. It is practically impossible for an examiner to know positively that a given person is free from venereal disease. Chancroids are easy of detection, but both syphilis and gonorrhoea may linger, capable of trans- mission, without giving any indications of their presence that can be detected by the inspection that the exam- iner of large numbers can give. This is true in the case of soldiers, and much more so in that of prostitutes, who, moreover, are adept in the removal of slight signs that may be present, and whose interest lies in escaping isolation. Most prostitutes are such for one of two reasons, either for the pleasure and excitement they find in the life or for the money they can make out of it. In either case their object is defeated for the time be- ing if they are isolated. Furthermore, there is always and everywhere a large amount of clandestine prostitu- tion, that is, that practiced by women not openly pro- fessing to do so ; and as registration of the prostitute is a necessary preliminary of her regular examination.

316 THE PREVENTION OF EPIDEMICS

a large amount of venereal disease thus escapes detec- tion. Naturally, too, the amount of this clandestine prostitution increases with the severity and strictness of the measures of control over that which is licensed. As examinations are not usually made more than once a week, and in many instances not so often, a woman may develop a contagious discharge or sore the day after examination, and transmit disease to fifty men be- fore being examined again. A prostitute living near a Western post stated that she usually hiad intercourse with from fifteen to twenty-five men on the night fol- lowing payment of the troops, and with from one to five or six men on other nights, and investigations in Chi- cago, New York, and elsewhere have since shown that that is no unusual record for a prostitute.

American sentiment has never favored state licens- ing of prostitution. Without discussing the right and wrong of the matter, we must face the following con- dition as regards the army. It consists of aggregations of men, mostly young, mostly unmarried, and largely ignorant, who have abundant opportunity to gratify their sexual instincts, but with women who are under little or no control, many of whom are diseased, and all of whom are interested in avoiding treatment that involves isolation. The obvious courses of procedure are, 1st, the provision of wholesome surroundings and amusements to keep the men away from dives and bro- thels ; 2d, their instruction as to the nature and dangers of the venereal diseases, so that the large amount of these due to ignorance may be eliminated ; 3d, advice as to the best methods of avoiding disease in case they are so persistently foolish as to expose themselves to it. The instruction as to the nature and danger of the

VENEREAL DISEASES 317

venereal diseases may be derived from the following consideration of them.

Gonorrhoea

Gonorrhoea or " clap" is a disease of such great an- tiquity that it may be as old as prostitution itself, and the first half of the fifteenth chapter of Leviticus indi- cates that Moses knew it and also knew that it was conveyed by contact, and that he provided rules to pre- vent its spread.

The disease is due to a bacterium known as the gono- coccus. This organism occurs constantly in the gonor- rhceal discharge, and the disease can be pro- -^ duced by artificial inoculation with it. It is very hard to cultivate artificially, and is readily de- stroyed by drying, heat, and antiseptic drugs. It may live for some time on towels or linen, or in warm water. It grows on mucous membranes, and those of the gen- ital and urinary passages, of the eyes, mouth, and rec- tum may be affected.

The young are more susceptible to its action than the old, and children are particularly easy of infec- tion. The disease once started in hospitals j» «« for children or in orphan asylums, espe- cially among little girls, is apt to become epidemic.

Transmission is usually by sexual contact, but it may

occur through mediate transfer, as by towels, soiled

hands, penis syringes, or urethral sounds. irirflTia

Such methods are uncommon, however, and

mission little credence can be placed in the story of

the man who thinks he got it from a water-closet seat. Strain, as from heavy lifting, can never cause the dis- ease, though often alleged to do so.

318 THE PREVENTION OF EPIDEMICS

The incubation period varies considerably, and the disease may manifest itself within a day of the impure _ - connection or it may not do so for ten or

^ twelve days, or for some intervening period.

It usually begins with slight burning on urination, which leads the subject to examine his penis, when he may find the margins of the urinary opening «.^^ red and somewhat puffy. Or the lips of the

. opening may be stuck together when he

arises in the morning, and a drop of clear discharge, like white of eggy can be expressed from it. The symptoms increase rapidly, and within another day or two the disease is at its height. The discharge is then more profuse, is creamy in color and consistency, the penis is sore, and urination painful. Erections may be frequent and painful, especially when the patient is in bed and when the inflammation has extended out into the body of the penis. These may cause intense pain, and the organ may be curved. This condition is known as chordee. The inflammation may extend to the bladder, causing very frequent and painful urina- tion ; to the testicles, causing swelling, pain, and some- times abscess formation, and often leading to stoppage of the duct leading from the testicle to the seminal bladder, and so rendering the former useless as a pro- creative organ. Germs may be carried to the lym- phatic glands in the groins, and cause them to become very painful, tender, and swollen, and oftentimes to suppurate. This glandular swelling constitutes a bubo.

These various troubles may cause great pain and suffering, but, in the absence of further complications, they lessen in severity after a time, usually from one to six weeks, the swellings subside, the discharge dimin-

VENEREAL DISEASES 319

ishes or ceases, and the patient may think he is well. Or he may recognize that he has gleet. This pg-gig* is a condition not attended by other symp- g„«Q toms than the presence of a small, clear drop of discharge in the early morning, and it is usually re- garded as of no importance. It is gonorrhoea, however, and is capable of setting up the disease in others, and many unfortunate brides have been so infected. It may persist for months or years, and other manifestations of the disease may do likewise. Many men have suffered or died from the results of gonorrhoea ten, twenty, or more years after they thought themselves cured of it ; or, worse still, they have seen their wives or children sicken, become blind, or die as the result of it, and have had no thought that they were themselves responsible for the calamity.

The complications of gonorrhoea are so numerous, so serious, and some of them apparently so remote, that there is no space to discuss them here, but nomnli some of them will be mentioned. Stricture ^3*1--- is one of the most common. It is often pre- sent when a gleet persists. It may cause obstruction of urine, great suffering, and serious or fatal kidney disease years after the acute gonorrhoea. The principal symptom is obstruction, usually partial, to the urinary stream. In- flammation of the prostate gland may develop and last for years, causing pain in urination and perhaps during defecation, pain deep between the legs, marked nervous symptoms, and general invalidism. Gonorrhoeal rheu- matism^ or joint inflammation, is always hard to treat, causes great pain, and tends to last for a long time. It may result in great deformity and permanent crippling. Tendon inflammation may also occur and produce symp-

320 THE PREVENTION OF EPIDEMICS

toms much like the joint troubles. Pain and tenderness of the heel or of the great tendon leading upward from it may result from gonorrhoea and prevent marching. Mye diseases of at least two kinds result from this dis- ease and always endanger and frequently destroy the sight. Gonorrhoea is one of the great causes of blind- ness, the disease often developing in children at the time of birth, from infection entering their eyes from their mothers' genitals, the mothers often being infected by their husbands, who thought themselves cured before marriage. The disease may also be conveyed to the eyes by the hands after urinating or wiping away discharge from the penis. It may be transferred from one person to another through the medium of towels, wash-cloths, medicine-droppers, and other things in common use. Blood-poisoning, that is, the diffusion of germs through the blood, may result from gonorrhoea and may cause death. Heart disease may be a complication, and often accompanies blood-poisoning. It may cause death early or may be apparently recovered from, and the heart may break down from the damage done it only after the lapse of years. Owing to the levity with which the disease is often regarded, this complication may not be detected at the time of its occurrence.

As already stated, the subject of gonorrhoea is a source of danger to his companions and his family, and — in military life it is desirable that he should

^, be confined to hospital, at least during the

time of most active symptoms, and that all men should be cautioned against using the towels or linen belonging to others. No man worthy the name would deliberately infect another person with his dis- ease, but many men unintentionally do so. All should

VENEREAL DISEASES 321

be instructed to abstain from sexual intercourse until entirely cured.

Without condoning or attempting to justify illicit in- tercourse, we must recognize that many men will indulge in it in spite of instruction, warning, and ^ example, and it is the part of economy and ^ makes for the efficiency of the army if those men can be protected from disease in spite of their folly and misconduct. No infallible means of protection from venereal contamination is known except chastity, but the following measures may ofPer some degree of it. Urina- tion^ if practicable immediately after intercourse, tends to wash out germs that may have entered the urethra. Irrigation of the urethra with a mild antiseptic solution, such as permanganate of potash solution in strength of one part to three thousand, has a similar action. The use after intercourse of jellies or ointments containing anti- septic or anti-gonorrheal drugs put up in collapsible tubes has become rather common, because of the porta- bility and convenience of these as compared with irri- gations. The substances usually relied on in these pre- parations are protargol or other silver preparations, carbolic acid, and calomel. These preparations, of which the K packet is best known, are sold under various trade names, and most of them are fairly efficacious. Modera- tion in intercourse is advisable. Repeated intercourse in the space of a few hours brings about a congestion of the genitals which is slow in subsiding and which predisposes to infection. Condoms^ impermeable rub- ber coverings for the penis, are sold and used for the prevention of disease, and they should protect against gonorrhoea.

After the disease is once contracted the best way to

322 THE PREVENTION OF EPIDEMICS

prevent complications is by rest in bed and proper treat- p ment. Soldiers should, therefore, be taught

^ , to report early for treatment, and to con-

-, ,. tinue at it until entirely cured, to be cleanlv ^ m their habits, and by frequent hand-wash-

ing and care of towels and linen to avoid infecting the eyes, and (very important) to avoid con- sultation with advertising quacks or the use of adver- tised medicines, both of which are fraudulent.

Chancroid

Chancroid, soft chancre or soft sore, is the least im- portant of the diseases here discussed, as it is a local in- fection and does not do the general damage or assume the manifold and insidious forms that often characterize gonorrhoea or syphilis.

The typical and usual soft chancre is due to a small ^ bacillus which bears some resemblance to

that causing plague, but ulcers may be pro- duced on the penis, as elsewhere, by other organisms.

The incubation period varies from one to ten days, and its length probably depends on a number of fac- _ . tors, such as the degree of infection in the

^ woman, the presence and size of scratches

or abrasions on the penis, and the violence, length, and frequency of the infective intercourse.

The disease begins as a small ulcer, or sore, which may be no larger than the head of a pin. The favorite a—-- location is in the depression or groove just

. back of the head of the penis, though it

may be anywhere on that organ. Many sores may show at once, or one may appear at first and others develop later. The ulcer enlarges and deepens.

VENEREAL DISEASES 323

the surrounding parts are red, swollen, and tender, and the surface of the sore more so. A thin and usually moderate discharge is present, and is highly infectious, and its presence causes the development of the sec- ondary sores. Under proper treatment the ulcers can usually be healed in a few days or weeks, but if neg- lected or improperly treated or in inaccessible positions, they may spread and produce considerable loss of tis- sue, half or more of the head of the penis being some- times destroyed. The base of the ulcer, if not irritated, is usually soft as compared with the base of the syphil- itic chancre, hence the name soft chancre. Occasionally this sore may appear on the bag, on the lower hairy part of the abdomen, or anywhere, in fact, that the virus has entered the skin.

The most frequent complication is bubo, which oc- curs in about one fourth of all cases. It -, .. is very painful, causes lameness, fever, and ^ may require operation.

The methods mentioned as tending to protect from gonorrhoea are equally applicable here, except that irrigation would not be particularly valu- ~ able, as the sore usually develops exter- ^ nally rather than in the urethra. Washing the genitals in an antiseptic solution, such as one to one thousand bichloride, will offer a certain amount of protection. Early and proper treatment is required to produce speedy healing and lessen the tendency to the formation of buboes, and soldiers should report promptly for it.

Syphilis

There has been much speculation and discussion as to whether syphilis, or pock, originated in the old

324 THE PREVENTION OF EPIDEMICS

world or the new, whether the Spaniards brought it to America, or took it from here. At any rate, the dis- ease spread throughout Europe in the century follow- ing Columbus's voyages, and it has prevailed through- out the world until the present time, and is now seen in all ranks of society and all walks of life. It is the most dreadful of the diseases considered in this chap- ter because of its chronicity, the long time required for its treatment, the great variety of its manifestations, the number and seriousness of the conditions resulting from it, and the fact that it is the disease affording the most striking examples of the sins of the fathers being visited upon the children. The disease cannot be de- scribed or adequately discussed in the space allotted here, but a very brief outline of it will be given, in order to enable the line officer to impart some degree of informa- tion about it to his men.

Although the disease has been known and industri-

^ ously studied for centuries, it is only lately

that its cause has been known. This is the

very fine and delicate spiral organism mentioned in a

preceding chapter as a Treponema.

The commonest method of transmission of syphilis is

through sexual intercourse, and this is especially true

_ as regards soldiers, to whom many of the

. . other avenues of infection are not open.

mission -r» . .1 1 , 1 ,

xJut there are such other avenues and they

are numerous ; and innocent victims of this disease

are therefore more numerous than those of gonorrhoea

or chancroid. Among such methods we may mention

the following: —

Heredity. The disease may be inherited from either

parent, and may infect the child in the womb and cause

VENEREAL DISEASES 326

its death there, cause it to be born diseased, or to be born apparently well and develop the disease soon after. Or, in rare cases, it may be born apparently well and continue fairly so for years, and only show the disease in recognized form when it reaches the age of puberty.

Contact^ especially such as kissing, is a fairly common method of transmission. Ulcers or sores in the mouth are a common manifestation of the disease, and in such cases the organisms are present and sometimes numer- ous there. The saliva or discharge from such a mouth is highly infectious, and, if brought in contact with a slight scratch or sore, will give rise to the disease. Chil- dren and girls have many times been infected by kissing persons so affected, and syphilitic children may by this means infect the nipples of their wet nurses. For this reason, also, the spoons, cups, and other eating uten- sils and pipes or cigarette-butts that have been used by syphilitics, are dangerous. The blood and discharges from sores on syphilitic persons are infectious, and nurses and doctors are occasionally infected in dress- ing or operating upon such cases. Several instances of the kind have occurred in the army. Barbers may receive infection if they get wounds or scratches con- taminated by the saliva or blood of their patrons, and they may also transmit it through scratches or cuts. Dentists and their implements, if not clean, may transmit it.

The incubation period of syphilis, the time inter- vening between the infective intercourse and the first

manifestations of the disease, is long. It _

, , 1 . n Incuba-

is never less than ten days, is usually nearer

a month, and not very rarely it may be two

months or more before the chancre shows, while in a

326 THE PREVENTION OF EPIDEMICS

considerable proportion of infections, probably some- thing between a tenth and a fourth, the chancre does not show at all and a condition of latent syphilis exists. In such cases it may be many years before any mani- festation of the disease is recognized. As a rule, how- ever, the incubation period is from two weeks to one month, after which time the primary sore or chancre develops at the point of entrance of the virus. This fact may be of value in determining the manner of infection. If the chancre be on the genitals, it is usually a result of sexual intercourse ; if elsewhere, the case may be different. It may be on any part of the body, as on the top of the head or the ear, where it has been seen to result from bites received in fighting ; inside the rectum as a result of unnatural practices ; on the breast of a wet nurse ; or on the arm of a child vaccinated with virus from a syphilitic.

The chancre constitutes the first sign of the disease. It appears first as a small firm lump resembling a pim- _ . pie. This may enlarge considerably or not

« . at all, depending somewhat on its situation.

It usually ulcerates slightly at its top, and shows a slight discharge, which may be thin and clear, or purulent. The chancre is nearly always single, and secondary ones rarely develop. Its base is usually hard and firm and feels like cartilage or even like bone, hence this is called the hard chancre. It may be so small as not to be noticed, and, as the patient may continue feel- ing well while he has it, he may not know that he is diseased until the appearance of secondary symptoms after another period of six to twelve weeks. It is not rare to have soldiers appear with well-marked second- ary signs of the disease and no chancre, and denying

VENEREAL DISEASES 327

that they have had any. The secondary symptoms are usually plainly marked and lead the patient « ,

to seek treatment. They are referred par- ticularly to the skin and mucous mem- « branes, and the most common of them are skin eruptions, sores in the mouth and throat and about the anus, falling of hair, slight fever, pains in the bones or joints, anemia and pallor, and various eye troubles. The skin lesions of syphilis are so nu- merous and of such varied character that it has been said that they can simulate all other skin diseases. The arteries, heart, and internal organs may also be affected in the secondary stage. In fact, no other known disease manifests itself in so many ways as this one, and it simulates the greatest variety of af- fections, including smallpox and other eruptive dis- eases, malaria, liver abscess, tuberculosis of lungs, bones, or joints, epilepsy, and very many more. It is, therefore, obviously out of the question even to mention most of the symptoms here.

This stage may not manifest itself if the case is well treated in the primary and secondary stages. Other- wise it may merge with the secondary, or it rn^j^a may appear only after the lapse of years, gta^e It is characterized by deeper skin lesions, that show a tendency to ulcerate and form large and deep sores, by destruction of bone, the formation of swellings or tumors, and the degeneration of internal organs. Tertiary syphilis is more often mistaken for tuberculosis, cancer, and other chronic ailments, than for more acute ones. The syphilitic tumors may form in any part of the body, and those in the brain, heart, spinal cord, and other vital parts may be rapidly

328 THE PREVENTION OF EPIDEMICS

fatal. Syphilis is the most common cause of aneu* risin.

A large and important part of the harm done by syph- ilis was long not charged to that disease, and it is only comparatively recently that we have ^*' had the proof that enables us to know the

^, terrible extent of its ravages on the nervous

Nervous , t> • • vu j

system. rJegmning with nervousness and

^ neurasthenia, that may appear early in the

disease and completely destroy the happiness and com- fort of the patient and his family, the number of cases of disease of the nervous system due to it is very large indeed, and embraces a great variety of manifestations. Among these may be named many varieties of paraly- sis, muscular atrophy, many chronic headaches, about one fourth of all cases of insanity, all cases of general paralysis or paresis, probably all locomotor ataxia, and many of blindness and brain tumor.

Syphilis is transmissible in any of its stages ; highly so in the first, more so in the second, and but slightly «j . , in the third. The time of greatest danger , p is that during which there are sores, with

open moist surfaces, in the mouth, the nose, on the genitals, and about the anus ; and it is advisable, in military service, to con- fine in hospital men who present such lesions. At other times, if they are kept under observation by a medical officer and continue their treatment, they may safely mingle with their fellows and do full duty.

A large proportion of syphilitic cases are inade- quately treated and remain uncured because of the very general tendency of patients to neglect treatment or to stop it entirely as soon as they are free from discom-

VENEREAL DISEASES 329

fort and from disfiguring lesions. The disease may, in rare instances, be cured by a single dose of salvarsan or neosalvarsan, but in the majority of cases _ ,

that is not so, and treatment must be con- r m tinued for a period of months or years. Even when brought under temporary con- trol and apparently cured, the disease may still exist and merely be latent, to manifest itself later in the form of aneurism, locomotor ataxia, insanity, or some obscure trouble. There is much evidence to show that different strains of the Treponema tend to localize in different tissues, one strain in the skin, for instance, another in the blood vessels, another in the nervous system. This cor- responds to the observed fact that many cases of aneu- rism, locomotor ataxia, and general paralysis are to be found in persons who had few, slight, or no skin lesions with their syphilis. It is therefore very important that the continuance and energy of treatment should not be allowed to depend on the mere presence or absence of skin lesions, and that other means of determining whether the disease exists should always be used. Of such other means the Wasserniann test is now most widely known and most generally effective. Treatment should be continued until that test becomes negative and remains negative for some months. The test should be repeated at intervals of about six months for two years after treatment has been discontinued, and in the event of the test showing a recurrence, treatment should be resumed. When a man has been free from symptoms of disease and has had a negative Wassermann reaction for two years it may be considered safe for hira to marry, thoTigh it must be borne in mind that there is even then a chance of his developing symptoms later.

330 THE PREVENTION OF EPIDEMICS

The special preventive measures that may be em- ployed by men exposing themselves to the dangers of _ polluted intercourse are the same as were

^ mentioned for gonorrhcea and chancroid. A

small amount of experimental and clinical evidence also indicates that protection may be conferred, in at least some instances, by the use of a calomel ointment. This is thirty per cent calomel in lanolin, and should be well rubbed into the penis and exposed parts for from five to twenty minutes, at the conclusion of the intercourse and after the use of the irrigation and wash mentioned as preventive of gonorrhoea and chan- croid.

Mixed Infections

One may be simultaneously infected with two or all of the venereal diseases, and in such instances the more quickly developing gonorrhoea or chancroid masks the presence of the chancre, and great surprise may result when the secondary symptoms of syphilis become mani- fest. Occasionally the chancre develops inside the urethra and occasions a slight discharge which may be mistaken for gonorrhoea, or the latter disease may co- exist. In either event the chancre may be overlooked. More frequently, however, the confusion arises from the coexistence of soft and hard chancres. It is gener- ally believed by men having venereal sores that the soft sore is never syphilitic, and that it always arises within ten days, while the hard chancre is always syphilitic, and never appears within ten days. These are usually true as related to pure single infections. But the viruses of soft chancre and of syphilis may both enter the skin at the same point, in which case a soft and ulcerating

VENEREAL DISEASES 331

sore may develop early and be followed by a large suppurating bubo, a thing not occurring in pure syph- ilis, and may heal under local treatment, leaving no induration, or only a slight one that is ascribed to inflam- mation. The syphilitic virus nevertheless continues its work and in due time the secondary symptoms develop. Some soft sores, especially those burned with acids, have a base of inflammatory tissue that may greatly resemble the hard base of the syphilitic sore.

So difficult is the differentiation of syphilitic from non-syphilitic venereal sores, by the appearance alone, that most careful practitioners do not definitely decide that a given sore is syphilitic, and therefore do not begin constitutional treatment until the diagnosis is made by the finding of the Treponema,, by a positive Wassermann reaction, or by the occurrence of second- ary symptoms. These things appear in the order named, and, as it is important that treatment should begin as early as possible, they are for this purpose valuable in the same order.

SUPPLEMENT

THE PREVENTION OF MENTAL AND NERVOUS DISEASES

CHAPTER XVI

THE PREVENTION OF MENTAL AND NERVOUS DISEASES

The amount of inefficient army service and the num- ber of discharges because of insanity and nervous dis- eases are sufficiently great to justify and to demand a brief discussion of those troubles and of what may be done by the officer or enlisted men to prevent or avoid them. For this reason the main factors influencing their occurrence will be mentioned and the preventive measures, so far as such are known, pointed out or made self-evident.

The Predisposing Causes

Bad heredity is probably the largest single factor in the causation of these diseases, and it is manifestly the one over which society in general has least influence and the person inheriting has ^

none.

We may say of heredity, though, that it is not always damning in its influence; a good many normal persons and a considerable proportion of brilliant ones are of stock that, from a biological standpoint, can only be considered bad. At the same time many persons who do show the evil effects of bad inheritance are not neces- sarily insane, epileptic, or useless because of " nervous- ness," but they stand closer to the stage of incapacity than do normal folk, are more heavily handicapped in

336 THE PREVENTION OF

the race of life, and lie under the greater necessity for guarding themselves from evil influences.

Heredity is a factor in most of the disabling func- tional disorders of the nervous system, including the two major groups of insanity, known as dementia pre- cox and manic-depressive insanity, epilepsy, hysteria, and nervous instability, and those stoppages of develop- ment that result in the states known as imbecility and "cussedness," all of which ai-e found in the army.

Education, its lack, or the improper direction of it, exercises a very great influence on the development of mental and nervous diseases. It acts first by leading directly to the formation of proper habits of thought and conduct, and, secondly, by imparting a degree of knowledge that dis- sipates, or tends to dissipate, the ignorance in which false beliefs, groundless fears, and misdirected enthusi- asms flourish. The earlier proper measures of education are undertaken, the more effective they are in accom- plishing the great and important result of teaching the individual moderation and self-control, and many a spoiled or incorrigible child becomes a less useful citizen, or passes to the congregation of the incompetents, for lack of the loving but firm and wise parental training that every child is entitled to and should get. " He that ruleth himself is better than he that taketh a city," but his chances of ever doing either are not very good unless he be taught early to rule himself. The army itself is a great educational institution, and, though its training comes late and its methods are inelastic and prove harmful to some of the unstable ones for whom they are not well adapted, it disciplines and strengthens apd makes useful citizens of quite a number who might

MENTAL AND NERVOUS DISEASES 337

never become such without the self-control and regu- larity of life they learn therein. Officers should try to make discipline conform to individual needs, and should exercise all their patience in getting the recruit started in the right way of training.

Age is an important factor in determining the time of onset and the type of insanity. The type most fre- quently seen in the army is that known as dementia precox, and it is most common ° because the large majority of soldiers are in early man- hood, the time at which it is particularly apt to show. It may occur as early as puberty and occasionally after the thirtieth year. Another large group, manic-depres- sive insanity, is particularly apt to recur from thirty- five to fifty, and the involutional insanities, those due to arterial sclerosis and the degenerative processes of old age, occur after fifty as a rule.

Habits are of the greatest importance in the preven- tion and control of nervous diseases. Education is a failure if it does not lead to the formation of good habits, such as are helpful to the individual, to society, or to the race. Habits become characteristics, characteristics make up character, char- acter is what a man is, so that we may truly say that a man of good habits has built his character and his very being on a solid foundation, and the difference between stability and instability of mind and character may sometimes be, in the final analysis, a difference of habits. There are some habits, however, that directly lead to disease or poisoning that act as exciting causes of in- sanity, and some others that develop into characteristics so constantly found in insanity that they may be con- sidered ^n essential part of it.

338 THE PREVENTION OF

Characteristic of all insanity is an intense egotism, a centering in self of all thought and all natural phe- nomena, a selfishness that alters the whole world or the whole universe in order to allow it to act upon or for the individual. Whether he be exalted or depressed, a king or a worm, God or the devil, a Saviour or the worst of sinners, he is at least the center of things, a tremendous ego. It is obvious that habits of thought or action that encourage egotism and selfishness, such as introspection, disregard of the rights of others, undue sensitiveness, suspiciousness, seclusiveness, brooding, anxiety, and undue worrying are harmful in this as in other directions. Harmful, also, as tending to instabil- ity, are undue love of excitement and constant seeking for variety, change, and outside amusements. Improper sexual habits, such as masturbation, sexual perversions, sexual images of thought, are harmful in two ways : by bringing about frequent states of excitement, and by producing a mental state of depression, shame, feeling of unworthiness, fear, and suspicion that others may learn the facts, all such as to upset the proper self-con- fidence and self-respect so essential to poise, self-control, and clear thinking. Habits of indulgence in drink and harmful drugs, especially the former, constitute probably the largest single factor except heredity in the causation of insanity, and will be discussed later, while those habits predisposing to syphilis have been considered.

On the other hand, it may be stated that there are no greater preventives of insanity than those measures of conduct and the cultivation of those virtues which we all at heart recognize as good and desirable, how- ever much onr conduct points to the contrary. Among physical habits and practices thus helpful we may men-

MENTAL AND NERVOUS DISEASES 339

tion chastity, regularity of bowels, of sleep, food, and exercise of body and mind, sobriety and moderation in general, temperance in all things, and total abstinence from things known to be harmful. Among mental traits to be encouraged are a healthy interest in religion (and by " healthy interest " is meant such as leads to unself- ishness, helpfulness to others, faith, hope, charity, and cheerfulness), good reading, good thinking, broad sym- pathies and wide interests, and courage. The amount of insanity and of nervous breakdown in which lack of courage or *' loss of nerve " is a main characteristic is very large.

The Exciting Causes

Easily chief among the exciting causes of insanity and nervous diseases is alcohol. " It is a strange commen- tary upon human frailty that all the poisons which assail man through accident and the dangerous trades in which he must engage, and all the poisons which are elaborated within his system, as in nephritis, diabetes, thyroidism, and acromegaly, are to- gether responsible for but a small fraction of the number of cases of mental disease due to his deliberate ingestion of one poisonous substance — alcohol." Not only does alcohol directly and alone cause a large amount of in- sanity, but it is the last straw that serves to break the suffering and already weak back of many a person whose nervous organization is congenitally weak. A very large percentage of cases of dementia precox and of other forms of insanity first manifest signs of disturb- ance after alcoholic excitement. Furthermore, such in- dividuals are apt to be particularly susceptible to the influence of alcohol and to be disturbed by relatively small amounts of it

340 THE PREVENTION OF

The more common alcoholic nervous disturbances, varying from mere impairment of will power to " tre- mors," "horrors," and "jim-jams," are unfortunately only too well known. As stated before, the person in- heriting a predisposition to nervous unbalance is under a heavy handicap and must take great care to avoid harmful influences, and there is no influence that he should more carefully avoid than that of alcohol.

Poisoning by lead, mercury, and some other metals may cause insanity, neuritis, and other disturbances. Other ^^^ frequency and speed with which the

~ . habitual use of morphine, cocaine, chloral,

and other narcotic drugs undermine the will, the powers of application, and the morals of their users and make nervous wrecks of them are all too familiar. Addiction to such drugs is akin to drunk- enness and is in itself an evidence of weakened mind and disordered nervous system.

The normal body produces poisons which it is ordi- narily able to get rid of or to neutralize without harm -J , to itself, but when, by reason of disease,

p . such as Bright's disease, diabetes, or cirrho-

sis of the liver, these are not excreted as in normal conditions, or when, by reason of other diseases, as of the thyroid gland, they are elaborated either in too great or too small amounts, nervous disturbance up to and including complete mental upset may result. It is possible that the poison retention resulting from mere constipation might be influential in similar directions, and it is a matter of frequent observation that an attack of depression or of irritability may be caused by con- stipation and relieved by a purge. The pregnant state causes insanity relatively frequently, though whether

MENTAL AND NERVOUS DISEASES 341

because of retained poisons or of disturbance of ductless

glands or for other reasons is not known. Epilepsy is

greatly influenced by the kinds and amounts of food

ingested and by the state of the excretions, and there

is much to show that it is at least associated with a

condition of self-poisoning.

When because of heart disease, arterio - sclerosis,

stoppage of a vessel from any cause, or of anemia, the

circulation in the brain or the amount of _. .

blood carried to it is interfered with, it suf- ^

. . , tory

fers, and the result is impaired or disturbed -i-j- "1 i-

mentality, that may amount to actual de- mentia or insanity.

Syphilis is the only infectious disease that causes a very large number of cases of insanity and of other severe forms of nervous disease. About one fourth of all cases of insanit}', as observed ^^ in soldiers at the Government Hospital for the Insane and in civilians at the Danvers (Mass.) State Hospital and in a number of other institutions, are syphilitic; ])robably one fifth are due wholly to this disease. In addition, as stated before, all or practically all locomo- tor ataxia, many types of paralysis, much neurasthenia, and a vast number of other cases of nervous disease are of the same origin.

Typhus, typhoid, malaria, meningitis, pneumonia, and

other infections may cause insanity, neuritis, paralysis,

and other nervous disturbances, but the f re- -.. . _

1 • , , 1 • 1 ,. 1 Other In- quency with which they do so is relatively , ^

slight as compared with syphilis. Diphthe- ria is very apt to canse paralysis of the throat or of the nerves supplying the heart. Mumps occasionally results iu deafness from degeneration of the auditory nerve.

342 THE PREVENTION OF

Sleeping sickness is principally a disease of the nervous system. Pellagra, though not definitely known to be caused by infection, has so many points of resemblance to infectious diseases that it may be mentioned here. It very commonly has mental disturbance as one of its most striking features.

Injury, especially injury to the head, may be the direct, exciting cause of insanity, epilepsy, hysteria, or minor troubles. It, like most of the infec- tious diseases mentioned, is more apt to have such effect in persons prediposed to nervous disturbance. Persons strongly predisposed to mental trouble may be upset by relatively trifling things, of a character, as . already indicated in regard to alcohol, in-

fections, and trauma, such as would not disturb a person of sound nervous consti- tution. Likewise apparently unimportant worries, such as might be occasioned by anxiety as to obtaining or retaining a position, by an unjust accusation, by a dis- turbing social engagement, or by a mere fear of making a social blunder, may act as a determining factor in mental disease. It may be readily understood, then, that the change of environment that occurs on enlistment, the transfer possibly from a home where the individual's weakness has been supported, his peculiarities over- looked, his deficiencies supplied,, to a barracks where the men have no interests or acquaintances in common with him, where his weakness is imposed upon, his peculiarities pointed out and his deficiencies jeered at, may prove more of a burden than his weak mentality can bear. Add to that the pangs of homesickness, the brooding over the apparent injustice of disciplinary measures, the worry incident to learning drills and nevr

MENTAL AND NERVOUS DISEASES 343

duties, the fear excited by lonely sentry duty, the feel- ing of isolation caused by practical jokes, and possibly the actual petty tyranny of an unfair non-commissioned officer, and it is not remarkable that weak men break down under it. Later the real stress of campaign, the excitement of real combat, the fear caused by real dan- ger to life or limb may prove the disturbing factor. On the other hand, if the recruit stage be once passed, the man of poor inheritance may find in the army discipline a steadying and regulating influence, in his officers a parent-like, and in his comrades a brotherly control and friendship, in his routine a method and a regularity, and in his duties an inspiration and an ideal, which will serve to enable him to hold to his mentality, to master his fate.

INDEX

Abdomen, 6.

Abstinence, total, encouragement of, 28.

Acid, boric, food preservative, 39.

Acid, carbolic, antiseptic, 210; vermin killer, 72; use of, in flush closets, 63; for camp urinals, 98.

Acids, organic, food value, 35, 122.

Actinomycosis, transmission of, 37.

^robic bacteria, 182.

Age, affecting mental and nervous states, 337; factor in efficiency, 4; incidence of venereal disease, 317.

Air, infection borne by, 258; moist, in rooms, 69; space per man, 56; supply, as predisposing to disease, 155; value of, 20.

Albuminuria, due to faulty diet, 34.

Alcohol, in cold climates, 136; in trop- ics, 125; on march, 28, 31; predispos- ing to disease, 157; use of, exciting cause of insanity, 339.

Alimentary tract, diseases due to infec- tion through, 223.

Amoebic dysentery, 179.

Anserobic bacteria, 182.

Anaphylaxis, 186.

Aneurism, due to syphilis, 328.

Animal carriers of disease, 191, 262.

Animal parasites, 168; minute, 177.

Ankylostomiasis. See Hookworms.

Anopheles, 278; a man-lover, 286; breeding-places of, 284; flight of, 285; salt water, 284.

Antelope, reservoirs of sleeping sick- ness, 200.

Anthrax, 199; transmission of, 37.

Antiseptics, 219.

Antitoxin, as remedy for diphtheria, 221; for prevention, 274.

Anus, irritation of, 64.

Appetite, effect of cooking on, 39l

Auto-intoxication, 167.

Avoidance of sick, 212.

BacilU, 182. Bacteria, 37. 183.

"Barbiero," carrier of Chagas' disease, 275.

Barracks, heating of, 69; hygiene of, 54; odor, avoidance of, 21; vermin in, 72.

Bathing, as predisposing cause of dis- ease, 158; before battle, 118; by ros- ter, 62; in camp, 83; in tropics, 129.

Bathrooms, 62.

Bathtubs, 67.

Battlefleld, hygiene of, 117.

Bedbugs, 22, 310; and plague, 299.

Bedding, airing of, 23'.

Bednets, need of, 57, 296.

Beri-beri, 34.

Beverages, 47.

Bichloride of mercury, antiseptic and germicide, 219.

Bill of fare, weekly, 48, 50.

Bleeders, 149.

Blindness from wood alcohol, 29.

Body, natural defenses of, 208; resist- ance to tuberculosis, 199.

Body-poisons, as cause of insanity and nervous disease, 340.

Body-type and causes of death, 5.

Bowels, regulation of, 24.

Breeding places of mosquitoes, 286; destruction of, 286.

Brill's disease and typhus, 306.

Brush clearing, as anti-mosquito meas- ure, 295.

Buboes, 16; chancroidal, 322; gonor- rhceal, 319.

Buildings, 54.

Butter, 45.

Buttermilk, 45.

Ciimp, arrival at, 117; bathing in, 83; change of site to shorten epidemics, 251; cooking, 87; disposal of human excrement in, 93, 100; fly-preven- tion in, 91-100; garbage disposal in, 91; hygiene of, 73; incinerators, 91; kitchens in, 86; kitchen waste, dis- posal of, 89; latrines, 93; sanitary training tat enlisted men in, 101;

346

INDEX

causes of infection of, 76, 160; choice of, 74, 75; influence on health, 74, 77; requirements for, 74, 75; shelter in, 77; streets in, 78; urinals in, 100; vermin in, 78; water supplies for, 80.

Camp-sites, requirements for, 74, 75.

Cancer, as effect of smoking, 30.

Canning, in food preservation, 39.

Cans, garbage, care of, 52, 61.

Carbohydrates, 34.

Carriers, contact, 229; contaminative, 201 ; development of disease germs in, 202; food handlers as, 252; healthy, 188; human, 187; insect, 200, 202, 275; inanimate, 202; of cerebro- spinal meningitis, 188; of cholera, 189; of diphtheria, 188; of disease, 187; of dysentery, 189; of infantile paralysis, 188, 260; of influenza, 260; of intestinal worms, 189; of menin- gitis, 260; of scarlet fever, 260; of typhoid, 189.

Chagas' disease and "barbiero," 275.

Chancre, of syphilis, 326.

Chancroid, 322.

Chest, shape, 6; mobility, 6.

Chewing gum, use on march. 111.

Chicken pox, 255; air-borne, 266; cause of, 256; incubation period, 265; sec- ond attacks, 257.

Chiggers or jiggers, 176.

Childhood, diseases of, 256.

Chlorine, fumigation with, 217; to ptirify water, 108; use in field, 108.

Cholera, carriers of, 189, 233; cause of, 226; contact infection, 243; control of food dealers during epidemics of, 252; early diagnosis of, 245; fly- borne, 239; isolation of cases, 246; milk-borne, 236; origin of epidemics, 226; prevention of epidemics, 244; report of cases, 247; vaccination to prevent, 253; vegetable-bome, 237; water-borne, 234.

Cigar and cigarette smoking, 30.

Clap. See Gonorrhoea.

Cleanliness, habits of, revealed by linen, 17; in prevention of typhoid, 249; personal, 22.

Climate, demands of, as to clothing, 30; cold, diet in, 34, 135; hygiene of cold, 133; hygiene of hot, 122.

Clothing, adjustment to needs, 30; as predisposing to disease, 158; chang- ing of, 23; for cold climates, 136; for

marching, 113; for tropics, 126; qual- ity of issue, 24.

Cocci, 182.

Cockroaches, as cholera carriers, 239.

Coffee, 47.

Cold, to preserve meats, 38.

Cold climates, air of, 133; clothing in, 136; crowding in, 134; effect of alco- hol in, 136; food in, 135; frost-bites, occurrence of, 139; hygiene in, 133; scurvy in, 135, 140; shoes for, 138; snow-blindness in, 142; ventilation in, 134; water supplies in, 134.

Colds, cause of, 20.

Cold storage, to preserve foods, 46.

Comma bacillus, in cholera, 226.

Condiments, food value, 35.

Constipation, 45, 120.

Contact infection, in childhood diseases, 260; in cholera, 243; in diseases en- tering by respiratory tract, 260; in typhoid, 242; in syphilis, 325.

Contagion, when active in certain dis- eases, 266.

Continence, sexual, 27, 314; as pro- moting health of nervous system ,339.

Cooks, company, common faults of, 39; importance of, 50.

Cough, in recruit, 10; tobacco, 29.

Cresol, solutions, as antiseptics, 220.

Crowding, dangers of, in cold climate, 134 ; favors epidemics, 257.

Culex, 283; breeding-places, 284; car- riers of dengue and filariasis, 283.

Deaths, causes of, life insurance experi- ence, 5.

Dementia precox, age of onset, 337.

Dengue, 275, 282; mosquito transmis- sion of, 282.

Deodorants, use of, 64.

Deprivation diseases, 168.

Dhobie itch, 130.

Diagnosis, early, to control disease, 245, 270.

Diphtheria, as cause of paralysis, 341; carriers of, 188, 255, 260; cause of, 256; incubation period, 265; in dogs and cats, 200; second attack, 257; when contagious, 267.

Discharges from body, as source of in- fection, 261; care of, 273.

Disease, carriers of, 187; exciting causes of, 162-186; predisposing causes of, 147-160.

INDEX

347

Disease manifestations, meaning of, 186; influence of season upon, 256.

Diseases, immunity to, 209; natural de- fenses against, 208; specific remedies for, 220.

Dishes, in transmission of disease, 238.

Disinfectants, 219.

Disinfection in control of typhoid and cholera, 249; of various diseases, 212; means and methods of, 216.

Drainage, as anti-mosquito measure, 286.

Drains, clogging of, 62.

Drying of foods, 46.

Dust, in spread of disease, 238.

Dysentery, carriers of, 189, 233; causes of, 226; fly-borne, 239; milk-borne, 236; origin of epidemics, 226; vacci- nation in, 253 ; vegetable-borne, 237 ; water-borne, 234.

Ears, examination of, 9.

Education, as factor in mental and nervous diseases, 336.

Emissions, seminal, 27.

Endotoxins, 186.

Engineering works, in prevention of disease, 215.

Environment, influence of, on develop- ment of mental and nervous diseases, 342; as predisposing to disease, 154.

Epidemics, due to milk, 236; due to water, 234; of typhoid, 236; origin of, in diseases entering by alimentary tract, 226.

Epilepsy, 341; due to injury, 342; indi- cations of, 11.

Exercise, 21; in tropics, 123, 129.

Exposure, as predisposing to disease, 153.

Eyes, affections of, transmitted by toilet articles, 22; examination of, 8; infection with gonorrhcea, 320.

Fats, 34.

Feces, disposal in camp, 93, 100; dis- posal on march, 116; disposal from typhoid, cholera, etc., 250; habitual inspection of, 61.

Feet, care of, 23, 31; of reoruit, 12; stinking, sweating, 14.

Filaria, and elephantiasis, 175; mos- quito-bome, 275; life history of, 174.

Fingers, 12.

Fires, open, as aid to ventilation, 68.

Fish, 61 ; destroy mosquito larvse, 290.

Flat-foot, 15.

Fleas, and plague, 201, 298, 299; life history of, 299; measures against, 304.

Flies, as carriers of cholera and dysen- tery, 239; of typhoid, 238; as distrib- utors of certain diseases, 269; flight of, 241; life history of, 240; preven- tion in camp, 91-100; protection from, 52, 59.

Floor room, minimum, 56.

Flukes, 169.

Fomites, in diseases entering by respi- ratory tract, 260; in typhoid-like diseases, 244; most dangerous kinds of, 261; utensils as, 262.

Food, care of, during epidemics, 252; dealers in, control of, 252, 269;efifect of, after prolonged exertion, 141; effect of, in very cold clim»te9,_135; in tropics, 123; on march. 111. '^>v_^

Foods and preparation, 33.

Formaldehyde gas, 218.

Frost-bite, 139.

Fumigation, to kiU mosquitoes, 294; to prevent disease, 217.

Garbage, disposal of, in camp, 91.

Garbage cans, care of, 52, 61.

Gases, as caxise of disease, 164.

Gastric juice, as defense against dis- ease. 208.

General paralysis, due to syphilis, 328.

German measles, 255; cause of, 256; incubation period, 265; second at- tacks, 257.

Germicides, 219.

Glanders, carriers of, 194.

Gleet, 319.

Gonorrhoea, carriers of, 190, 317; dis- cussion of, 317-321.

Ground-itch, 173.

Habits, as predisposing cause of dis- ease, 152; fixity of, after certain age, 4 ; importance of, in regard to nerv- ous and mental disease, 337.

Ham, raw, danger of, 39.

Ham-bones, in soups, 43.

Hammer-toe, 14.

Hands, care of, 23 ; cleanliness for meals, 60; washing after visit to toilet, 64.

Headgear, for tropics, 127.

Health inspections, 247.

348

INDEX

Heart disease, 5; due to gonorrhoea, 320; due to syphilis, 327 ; irregularity due to tobacco, 29.-

Heat, in disinfection and sterilization, 216.

Heating, 57, 59; by hot-air furnace, 70; by hot water, 70; by open fires and stoves, 69.

Hemorrhoids, 7, 8.

Heredity, and syphilis, 322; in relation to disease, 147; predisposing to men- tal and nervous disease, 335; trans- mission of germs by, in insects, 202; types of, 149.

Hernia, 7.

Hookworms, 128, 172.

Hydrocele, 16.

Hydrophobia, 191; description, 193; misconceptions concerning, 192.

Ice, and disease, 235.

Ice-cheet, 52.

Immunity, causes of, 211; to diseases,

209; to malaria, 277; varieties of,

209. Incinerators, field, types of, 91. Incubation period, of typhoid, 248; of

various diseases, 265; of yellow

fever, 280. Infantile paralysis. See Paralysis, in- fantile. Infection, as cause of insanity, 341; in

tropics, 122; transmission of, 26. Influenza, discussion of, 255-267. Insanity, discussion of, 328-342. Insects, as disease carriers, 200, 275,

diseases borne by, 275; in tropics,

130. Internal secretions, disorders of, 168. Intestinal worms, 168-174. Investigation of cases, 271; of typhoid,

cholera, and dysentery cases, 248. Iodine, as antiseptic and germicide,

220. Isolation, to prevent spread of disease,

213, 271. Itch, cause of, 176; ground, 173; dho-

bie, 130.

Jantkosoma luUi, as carrier of fly eggs, 202.

Kala-azar, and insects, 275. Kitchens, in camp, 86; waste from, dis- posal of. 89; hygiene of, 50-60.

Larvacide, as antiseptic and disinfect- ant, 220; how made, 291 ; use of, 291.

Larvae, infesting man, 275; of mos- quitoes, destruction of, 290; screw worms, 176.

Latrines, camp, 93; care of, 97, 99.

Lead poisoning, 165; avoidance of, 23, 25.

Leprosy, and insects, 275.

Lice, and plague, 299; carriers of relaps- ing fever and typhus, 275; diseases borne by, 306; Ufe history of, 307.

Lighting, interior, 56, 59, 67, 68.

Lime chloride, 63. See Chlorine.

Locomotor ataxia, due to syphilis, 328.

Limipy jaw, transmission of, 37.

Malaria, discussion of, 276; parasite of, discussion of, 177; nervous diseases caused by, 341; prevention of, 284; qmnine as specific for, 221.

Malta fever, transmission of, 44.

Manic-depressive insanity, age of on- set of, 337.

Marches, discussion of, 103-116.

Measles, 255; cause of, 256; conta- giousness, 259; incubation period, 265; second attacks, 257; when con- tagious, 266.

Mechanical causes of disease, 162.

Meningitis, cerebro-spinal, 255; car- riers of, 188, 260; cause of, 256; when contagious, 267.

Mental state, and syphilis, 328; as pre- disposing to disease, 151; effect of, on marching, 108.

Mess, lack of variety in, 40; manage- ment, books on, 53.

Mess-room, 59.

Milk, as cause of epidemics, 236, 263, 264, 269; tuberculous, 199.

Milk-sickness, 37, 44.

Mites, as disease carriers, 275.

Mosquitoes, 132; breeding-places of, 284, 286; catching of adult, 294; dengue-bearing, 282; diseases borne by, 276; life history of, 285; malaria- bearing, 277; measures against, 283; protection from, 132, 295; to be kept from sick, 296.

Mosquito net, use on march, 113.

Mouth, care of, 25.

Mucous membranes, natural defenses, 208.

Mumps, 255; cause, 256; incubation

INDEX

349

period, 265; second attacks, 257; when contagious, 266.

Nervous system, diseases of, 337-343;

syphilis of, 328. Neuritis, caused by infections, 341. Notification of cases of sicknees, 247,

270, 305.

Occupation, as predisposing to disease,

154. Oil, to destroy mosquito larvae, 291;

application to water, 292. Oysters and typhoid, 237.

Paralysis, due to syphilis, 328; due to diphtheria, 341.

Paralysis, infantile, 255; and stable- fly, 257; carriers of, 188, 260; incuba- tion period, 265; more common in warm weather, 257.

Paratyphoid fever, 225.

Pasteurization, 184.

Pellagra, insanity as symptom of, 342.

Penis, abnormalities of, 15.

Pension, notation of grounds for, 19.

Personal hygiene, 21.

Petroleum, crude, as pit dressing, 99; to destroy mosquito larvae, 291; in urinals, 64.

Phenol, antiseptic and disinfectant, 219.

Piles, 7, 8.

Plague, 275, 298; cause, 298; in rats, 195; in squirrels, 196; method of in- fection, 201, 298; notification of cases, 305; pneumonic, in Manchu- ria, 196, 299; prevention of, 302- 306; spread of, 195; transmission of, 299.

Pock. See Syphilis. '

Poisoning, by various substances, 166; metallic, 46; ptomaine, 57, 167; self-, 167; tyrotoxicon, 45; wood alcohol, 29.

Policing, poor, predisposing to disease, 159; and typhoid, 250; to prevent disease, 215.

Poliomyelitis. See Paralysis, infantile.

Predispiosition to disease, 147.

Pressure as cause of disease, 163; at- mospheric, 164.

Prevention, of beri-beri, 34; of gonor- rhoea, 321; of mosquito-borne dis- ease, 284; of nervous and mental dis-

eases, 336; of plague, 302; of relaps- ing fever, 308; of scurvy, 135; of syphilis, 330; of typhoid, 244; of typhus, 308.

Prostitutes, 315; prevalence of dis- ease among, 316.

Proteids, 33.

Ptomaines, as disease producers, 167.

Pyrethrum, fumigation with, 294.

Quarantine, to prevent disease spread, 214; meaning and use of, 215.

Quinine, as specific remedy, 221; to prevent malaria, 297.

Race, as predisposing to disease, 152.

Rats, and plague, 195, 201, 299; meas- ures against, 302.

Reaction to irritation as defense against disease, 209.

Reclamation of swamps, 286.

Recruit, the, 3; character of, 18; ex- amination of, 3-19.

Relapsing fever, 275; and lice, 306; of Africa, and ticks, 275, 309; preren- tion of, 308.

Respiratory tract, infection by way of, 255.

Rest, need of, 20.

Rheumatism, gonorrhoeal, 319.

Ringworm, 17, 130; transmission of, 22.

River fever, 275; and camp-sites, 76; and mites, 275.

Roaches, protection from, 52; and cholera, 239.

Round worms, 171.

Salt water, breeding of mosquitoes in, 284.

Salts, food value, 34; formation of, in iirinals, 64.

Sand-fly fever, 275. 309.

Sanitary soldier for each company, 101.

Scarlet fever, 255; carriers of, 188, 260; cause of, 258; incubation period, 265; second attacks, 257; when con- tagious, 266.

Schistosomum disease, 169.

Screening of houses, 295.

Screw worms, 176, 275.

Scurvy, in cold climates, 135; and vitamines, 34, 35.

Seasickness, 120.

860

INDEX

Season, influence on oocurrence of dis- eaee, 256.

Seat worms, 172.

Self-control, importance of, in preven- tion of nervous and mental disease, 337.

Sexual hygiene in tropics, 131 ; life, 27.

Shelter in camp, 77.

Shoes for cold climates, 138; for march- ing, 114; soiling, in camp, 244; use of, in tropics, 128.

Shower baths, 62.

Sick persons, avoidance of, 212.

Sickness, effect of, on marching, 106.

Sinks, kitchen, care of, 52.

Skin, affections of, in tropics, 130; un- broken, 86 defense from disease, 208.

Sleep, amount, 21; conditions of, pre- disposing to disease, 159.

Sleeping sickness, 179, 308; and ner- vous system, 342; and tsetse flies, 275, 308.

Smallpox, 255; as disease of childhood, 256; and insects, 275; incubation period, 265; second attacks of, 257.

Smoking, effects of, 29, 111; in day rooms, 58; of meat, 38.

Snow-blindness, 142.

Socks, for marching, 114.

Specific remedies, 221 ; as means of pre- venting disease, 222.

Spirilli, 182.

Spitting, danger of, 26; promiscuous, 29, 59.

Spores, resistance of, 183.

Spotted fever of Montana, 275, 309.

Sputum, as source of infection, 261.

Staphylococci, 182.

Starches and sugars, 34.

Stegomyia fascicUa, 279; breeding- places, 284; description of, 282.

Sterilization, means and methods, 216.

Stoves, 68.

Streets, in camp, 78.

Streptococci, 182.

8trictiu"e of urethra, 319.

Sulphur, fumigation with, 217.

Sunlight, as destroyer of bacteria, 184.

Swamps, drainage, 286; reclamation, 286.

Syphilis, 324-331; as cause of aneu- rism,insanity, locomotor ataxia, 328; cause of, 179, 324; hereditary, 325; incubation period, 325; indications of, for examiner, 9, 10, 11, 12, 14, 17;

period of contagiousness, 328; mar- riage after, 329.

Tabardilla and typhus, 306.

Tapeworms, 169; life history of, 170; transmission of, 37.

Teeth, care of, 25.

Tetanus, 182.

Texas fever, in cattle, 202.

Three-day fever, 309.

Ticks, carriers, of African relapsing fever, 309; of spotted fever, 310.

Toilet articles, individual use of, 62; transmission of disease by, 22.

Tonsillitis, 255; causes of, 256, 267; in- cubation period, 265; contagious, 267.

Toxins, as cause of disease, 185.

Training, faulty, and disease, 151; and insanity, 336.

Trains, troop, 120.

Transport ships, 119.

Trauma, exciting cause of disease, 162; of mental and nervous trouble, 342; predisposing to disease, 153.

Trembles, in cattle, 37.

Treponema, localization of, 329; and syphilis, 324.

Trichina, 57; life history, 174.

Tropics, hygiene of, 122-132.

Trypanosomes, and sleeping sickness, 200.

Tsetse fly, relation to sleeping sickness, 275, 308.

Tuberculosis, in cattle, 199; carriers of, 189; in company cook, 51; indication of, 14; transmission of, 26, 37, 44, 197, 199.

Typhoid, and nervous disease, 341; carriers of, 189, 229, 230, 233 ; cause of, 225; contact infection, 241; dust- borne, 238; early diagnosis, 245; fly- borne, 238; from shell-fish, 237; ice- borne, 235; incubation period, 248; isolation of cases, 246; methods of transmission, 228; mild cases, 229; milk-borne, 236; prevention, 244; route of infection, 224; transmission of, 22, 51; vaccine, 254; water-borne, 233.

Typhus fever, 306; and lice, 275; and nervous disease, 341; how transmit- ted, 306; prevention, 308.

Uncinariasis. See Hookworms.

INDEX

851

Uncleanlinesa, predisposing to disease,

159. Urinals, 64, 67.

Urination, careless, danger of, 26. Urine, disposal of, in camp, 100. Utensils as means of infection, 262;

carriers of disease, 61.

Vaccination, as cause of immunity, 210; to prevent cholera, 253; dysen- tery, 253; plague, 305; smallpox, 273; typhoid, 254.

Varicocele, 16.

Vegetables, 41; and disease, 236.

Veins, varicose, of leg, 13; of abdomen, 7.

Venereal disease, carriers of, 190, 312; general causes of, 314; general meas- ures of prevention, 314; mixed in- fections of, 330; prevalence in army, 313; urine as defense against, 209.

Ventilation, in prevention of disease, 213, 268; in very cold climates, 134; of barracks, 56, 59, 68.

Vermin, exclusion from kitchen, 52, 55; guarding against, to control epidem- ics, 269; in barracks, 72; in camp, 78; on recruit, 11, 16, 17, 22; on transtwrts, 119.

Vibrios, 182; of cholera, 226.

Vitamines, 34.

Voit's food standard, 35.

Walls, damp, avoidance of, 55.

Wassermann reaction in syphilis, 329.

Water, and disease, 26, 234, 252; drink- ing-, in tropics, 123; purification of, 80, 110; use on march, 108.

Water-closets, 57, 63.

Water-supplies, 65, 80, 234, 252.

Weight carried, and effect on marchicK, 105.

Wet dreams, 27.

Whip worms, 172.

Whooping cough, 255; cause of, 256; in animals, 200; incubation period, 265; second attacks, 257; when con- tagious, 266.

Wind, regard for, in placing buildings, 55.

Worms, in feces, 64; intestinal, 172.

Yellow fever, 275; eradication from old haunts, 280; incubation period, 280; mosquito, description of, 282; mos- quito transmission of, 279; natural history of, 280; prevention, 284; when dangerous to others, 281.

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