A manual of hygiene

Preface

This book has been written as the result of the author's experience in the class-room of the need of a concise text-book on Hygiene adapted to American conditions. It is not offered as a substitute for the many elaborate treatises on the subject, the study of which it earnestly aims to encourage.

It is believed, however, that much valuable time might be saved both to the lecturer and to the student by the use of a text-book embodying in concise form the fundamental principles of hygiene and preventive medicine, and that such time might be more profitably used for wider discussion of the subject in the lectureroom, and practical demonstration and study in the laboratory and elsewhere of the problems involved.

While the methods of laboratory examinations in various subjects have been indicated, no attempt has been made to make this a handbook of laboratory practice in hygiene. It is believed that the course in hygiene in most of our medical schools does not at present permit of this, and that the addition of any adequate technical discussion of laboratory work would convert this book into an unwieldy volume, without adding to its immediate usefulness to the under-

IV PRE FA CE.

graduate student. A manual of laboratory practice in hygiene might well constitute a separate volume.

It is hoped that in addition to medical students, for whom it was primarily written, this book may also be found useful for students in higher schools and colleges, who, as the future guardians of public health, need definite scientific instruction in the principles of hygiene.

The writer would acknowledge her obligations to the various works of European and American authorities, which she has freely consulted in the preparation of this book. Thanks are also due to the experts who have kindly given valuable counsel and criticism on various subjects requiring special knowledge and experience.

New York, June, i8g4.

Table Of Contents

Preface,

CHAPTER I. Introductory. — Public Health and Preventable Disease

The Province of Hygiene, I ; Conceptions of, in Ancient Times, 2 ; Waste of Life by Preventable Disease, 3-5 ; Economic Aspect of Preventive Medicine, 5,6; Encouraging Outlook from Achievements of Science, 6-9; Duty of Physicians to Preventive Medicine, 9, 10; Functions of Boards of Health, 10, II ; Necessity for a National Bureau of Health, 11-13-

CHAPTER II. Micro-organisms

Classification, Structure, etc., 14, 15; Conditions Necessary for their Life, 15-17; Reproduction, 17-19; Role in Nature, 19, 20; Channels of Entrance into the Human Body, 21 ; Examination of Bacteria, 21, 22.

CHAPTER HI.

Air.

General Remarks, 23-25 ; Composition and Effects of Various Gases, 25-30; Organic Matter in, 30, 31 ; Impurities and their Source, 31-39; Hygienic Measures for Maintaining Purity, 39-41 ; Unhealthful Occupations as Related to Dust, 41-44 ; Preventive Measures to be Used in These, 44 ; Examination of Air, 44-49.

VI CONTENTS.

CHAPTER IV. Climate

Factors, 50; Effects of Temperature, Density, Humidity, etc., 51-54; Observations on Climate in the United States, 55-57-

CHAPTER V. The Soil as Related to Health

Hygienic Significance, 58-60 ; Origin and Constitution of Soils, 60-63 > Air in Soils, 63-66 ; Ground Water, 66-68 ; Temperature of the Soil, 68, 69 ; Micro-organisms in the Soil, 70-73 ; the Examination of Soil, 73, 74.

CHAPTER VI. Water

Sources, Ultimate and Immediate, 75-85 ; Quantity of Water Required, 85 ; Contamination of Water and Diseases Traced to it, 86-94 ; Purification, 94-99 ; Examination : Chemical, Microscopic, Bacteriological, 99-103.

CHAPTER VII. Food

Classification, 104-108; Functions of Foodstuffs, 108-111 ; Quantity Required, 111-113; Influence of Age, Work, Sex, etc., on Diet, 114, il'5; Necessity for a Mixed Diet, 115-117; Digestibility, I17-120; Diseases Connected with Food, 120, 121 ; Diseases from Meat, 122- 125 ; Public and Private Measures Protecting Meat Supplies, 125, 126; Milk, 126-130; Examination and Control of Milk Supply, 130- 135; Cheese, Butter, Oleomargarine, Eggs, 135, 136; Vegetable Foods, 136; Cereals, and Preparations from, 137-139; Food Accessories, 139-143 ; Anomalies and Adulteration of Food, 143-145.

CHAPTER XVIII. Infectious Diseases: Their Cause and Prevention

Definition, 286 ; Conditions Necessary to Prove Microbic Origin of, 286, 287 ; Principal Diseases Due to a Specific Microbe, 287 ; General Classification of Infectious Diseases, 288, 289; Immunity, Predisposition and Resistance, 289-292 ; Spread of Infectious Diseases, 292- 294 ; Prevention of Infectious Diseases, 294.

CHAPTER XIX. Disinfection — Isolation — Quarantine

Disinfection by Heat, 296-302 ; by Chemicals, 303-305 ; Disinfection of the Sick-room, 305-308; Care of the Dead, 308-310; Isolation and Quarantine, 310-312.

CONTENTS. IX

Chapter XX

A Brief Account of the Cause and Prevention of the Principal Infectious Diseases, 313, 323.

Copy of Circular of Information to Physicians, regarding the Measures adopted by the Board of Health for the Prevention of Tuberculosis in the City of New York, 324.

Copy of a Circular of Information for Consumptives and Those Living with Them, 328.

LIST OF ILLUSTRATIONS.

PAGE

Fig. I. Forms of Bacteria . . . . . . . .16

Fig. 2. Petrie's Apparatus for Air Analysis . , . . . 48 Fig. 3. Seasonal Chart, Showing Mortahty at Different Ages for

Both Sexes and All Causes in the City of New York . 56 Fig. 4. Pettenkofer's Experiment, Showing Porosity of the Soil . 65 Fig. 5. Pasteur's Domestic Filter ...... 97

Fig. 6. Apparatus for Estimating the Number of Colonies in a

Plate Cultivation . . . . . . . .102

Fig. 7. "Measly" Meat 124

Fig. 8. Young Muscle Trichinae .125

Fig. 9. Freeman's Apparatus for Pasteurizing Milk . . . 134 Fig. 10. Damp-proof Course, Indicated by Dark Stratum of Slate

Running Beneath Cellar, and Above Ground Level . 148 Fig. II. Appliances for Ventilation . . . . . .165

Fig. 12. Rear View of Sanitary Grate, with Casing Cut Away to

Show Interior Construction and Air Chamber . .170

Fig. 13. Circulation of Air with Sanitary Grate . . ... 171

Fig. 14. Hot Water System 176

Fig. 15. Radiator with Register Set in Window Niche . . -177 Fig. 16. Blackman's Ventilator Fan ...... 182

Fig. 17. Summer Ventilation . . . . . . .183

Fig. 18. Winter Ventilation 183

Fig. 19. Air-Meter for Testing Ventilation 1 84

Fig. 20. Scheme for House Plumbing, Showing Ventilation of Soil-

Pipe, Traps and Vent' for Each Trap .... 189

Fig. 21. Trap with Water Seal ....... 191

Fig. 22. Ball and Water Trap ....... 192

Fig. 23. Vent-Pipe and its Connection with Traps . . .194

Fig. 24. McClellan's Vent I96

Fig. 25. Perspective View of McClellan's Vent in its Relation to

Trap and Fixture . . . . . , .196

Fig. 26. Closet with Porcelain Trap Attached .... 198

PAGE

Fig. 27. Lined Pail Used for Goux System 203

Fig. 28. Goux Pail with Lid on, Full, to Return to Works . . 203 Fig. 29. Vertical Longitudinal Section of Des Moines Garbage

Fig. 30. {a), (b) and (c). Comparative Tables of Measurements of Students Receiving Gymnastic Training, and No Training, . . . , . , . . . 238-240 Fig. 31. Series of Respiratory Traces by Kellogg, Showing Types of Breathing in Men and Women Under Various Conditions of Freedom and Restriction in Clothing; also, Likeness of Type in Male and Female Dog . 265, 266

Proper Form of Socks, (Ellis) ..... 269

Outline of Relation of School-seat and Desk . . . 284 Outline of Disinfecting Plant in Berlin. (From Pfuhl

and Nocht) 300

Near View of Disinfecting Chamber in Berlin . . . 301 Household Contrivance for Burning Sulphur . . , 306

Fig.

Fig.

Fig.

Fig.

Fig.

A MANUAL OF HYGIENE.

CHAPTER I. Public Health and Preventable Disease

Hygiene may be defined as the art of preserving health. In its most liberal sense, it concerns itself with the development and culture of both mind and body.

In earlier times its methods for securing these ends have lacked the precision which modern science is now able to lend it in many directions. This was necessarily the case so long as the contributions of modern physiology, pathology and bacteriology were practically unknown to science. The increased knowledge of the functions of the human body which we owe to modern physiology, affords a more exact basis for the formulation of rules which shall further the Maintenance of Health: and this may be considered as the first great province of hygiene.

The brilliant contributions of pathology and bacteriology to our knowledge of the cause of a large class of the devastating diseases of mankind, constitute an additional and precise basis for the exercise of the second great province of hygiene, which is the Prevention of Disease.

While we owe much of the definiteness of its present methods to modern investigations, hygiene boasts a history as old as the time of Moses, whose sanitary code was very explicit in its rules for personal, domestic and camp hygiene, as understood at that time. Personal cleanliness, the destruction of infectious clothing by fire, the disinfection of houses by lime, and even their burning, the isolation of the leper, and many other ceremonial observances, were practical conceptions of hygiene which were of untold benefit to the Jews, and unquestionably bore their fruit in the comparative immunity of that nation from epidemics at that time, and for long periods thereafter.

Even in the days of Homer we hear of the disinfecting powers of sulphur fires; and the personal hygiene of the Greek was calculated to maintain the health of the healthy at a high standard, although as a nation they had little pity or help for the delicate, the sickly, or the deformed. The Romans clearly recognized the value of pure water and drainage of soils, as archaeology has given proof; and recent investigations have shown that a wise foresight animated them when they built their magnificent aqueducts and planned their elaborate system of subsoil drainage ; while their military hygiene, as shown by the mortality from preventable disease in their campaigns, compares favorably with English camp history, or with our own dark chapters of the Civil War.

Still, there was little exact knowledge in these days of the causation of disease, which must always be the basis of prevention ; and with all the light that history can throw on the picture, the fact remains that the waste of life by preventable disease is one of the most startling features in the history of the race.

We hear of an epidemic in the time of Justinian which lasted practically fifty years with only slight and unimportant intermissions. The story of the plague in Europe is gloomy beyond expression. China at that time counted its dead by millions. Italy lost one-half of its population; the city of London buried over 100,000 people, and was only released from the plague by the equally devastating flames; while 1,000 grave-diggers in Constantinople, constantly occupied, were not sufficient to bury the victims of this scourge.

It is estimated that in three years time over twenty-five million human beings perished from the face of the earth, and the moral convulsions that followed as a consequence of such a reign of terror were scarcely less important in their influence upon the world.

The history of military campaigns offers us one of the most striking instances of the needless sacrifice of human life. It is a well-known fact that the loss to an army by the sword is small compared with that from sickness. It is said that during the French Revolution the English army lost in war twenty thousand men, but by mortality from sickness (most of the complaints coming under the head of preventable diseases) three times as many perished, while the number of men who were constantly on the sick list was ten times as great.

In our own Civil War the ninety-seven thousand men who died from the direct effects of their wounds, yielded their lives a willing and necessary sacrifice in camp or on the battle-field to the cause for which they fought; but beside those who fell on the battle-field there was another unfortunate contingent in the ranks, nearly twice that number (184,000) who perished during those four years the victims of preventable sickness, traceable directly to foul air, bad drainage, polluted water, imperfect quarantine, and other unsanitary conditions within the power of human beings to control.

The prevalence and mortality of the zymotic diseases— scarlet-fever, diphtheria, measles, etc. — in America and Europe, constitute them the great dreaded scourges of childhood. It is estimated from, the records of the London Fever Hospital that about six hundred thousand cases of these diseases, which are perfectly well understood to be preventable, occur in that country every year. The imagination can scarcely picture the amount of misery included in such numbers, involving as it does not only immediate suffering, but also lessened usefulness, and often destitution for the entire household concerned.

The enormous mortality among infants is a blot upon the civilized world, since it is due in the majority of cases to preventable conditions.

In North America it is estimated that from one-fourth to one-third of all the deaths in a community occur among children under one year of age; and in New York alone, during the summer months, fifty per cent, of the deaths occur among babies of this age. By far the larger proportion of these deaths are directly traceable to improper conditions of food and drink which a better knowledge of hygiene would •correct.

The entire subject has, however, not only its moral but its financial aspect, since preventable illness is not only a waste of life, but can be shown to be a waste of money as well.

An interesting example of this was published by Dr. Benjamin Lee, of Philadelphia, after a severe epidemic of small-pox which befell that city in 189 1-2. Dr. Lee estimates, on one side, the expenditure of the Philadelphia Board of Health under their policy •of concealing the condition of the city. He considers the loss to travel and traffic on railroads, the loss to liotel keepers, merchants and manufacturers from diminished patronage. He adds to these the cost of the care of the sick, the loss of time to them and to the State through their disability, and the expense of burial. Under these estimates the total cost of the ■epidemic was only a trifle less than twenty-two millions of dollars.

Dr. Lee then gives a similar estimate of what might have been the expenditure under a policy of preventive measures. This would have necessitated the •establishment of a Vaccine Bureau, with a large force of physicians for vaccinating the public, a disinfecting station, with all its details, and the publication and distribution of pamphlets of instruction to the public.

Under such measures of prevention hospital expenses would be reduced, as fewer patients would be ill ; the consequent loss by sickness, disability and death would be less; while, with the public confidence engendered by a wise and frank policy of this nature, the loss to travel and traflic was estimated as zero.

The sum total of this estimate leaves a balance to the credit of sanitation of over twenty-one million dollars. In other words, the epidemic actually cost the city of Philadelphia about twenty-two million dollars; while a policy of prevention, estimated in these details, would have cost about seven hundred thousand dollars.

There is, however, a brighter side to this picture, and one which offers us an encouraging basis for future work. This is to be found in the beneficent influence of civilization and the achievements of science during the past century, which have unquestionably lengthened the duration of life and abated some, at least, of its scourges.

It is said that in the sixteenth century the average duration of life was about 2114^ years. In the nineteenth century the same statistics give 40^^ years as the average period. Records of life insurance companies show that the expectation of human life has been increased 25 per cent, since the seventeenth century. The mortality of infants has decreased, by the same statistics, from 25 per cent, to 15 per cent, of children under one year; and this saving of life in the household, as well as in our foundling and other asylums, is directly traceable to attention to hygienic measures as regards proper diet and pure air.

The discovery and universal practice of vaccination ■can be shown to have saved hundreds of thousands of lives annually throughout the civilized earth, whereas a century ago one-tenth of all the people of the globe perished from small-pox, and nearly twice as many were permanently disfigured by its ravages. Some of the other great scourges of history have been limited, if not exterminated, by hygienic measures solely. This is notably true of leprosy and scurvy. Leprosy in the thirteenth century was as common as measles; but now, thanks to the sanitary principle of isolation, it is unknown in most of the civilized communities.

Scurvy, two hundred years ago, is said to have •caused more deaths in the British navy than all those from battle, wreck and accident put together. But the knowledge that this disease is due to a deprivation of vegetable and fruit diet, and the introduction by Captain Blake of lime-juice into the dietary of the army and navy, has practically abolished the disease among the military, with an immense saving of life as the result.*

An instance of the value of preventive medicine is found in Russia. Some years ago, under the old system of treating cholera, the annual loss of life in St. Petersburg amounted to from 23,000 to 25,000 persons. Referring to this fact, a well-known English sanitarian characterized the preventive treatment of the premonitory symptoms introduced by the English Board of Health as the most brilliant sanitary service ever rendered, since such treatment resulted in a saving of more than 60,000 lives to the English army. He aptly remarks that a similar loss inflicted on the enemy in battle would have received the enthusiastic official recognition of the Government, but for this really greater service to mankind there was none.

It is impossible to estimate what a saving of life will result in the future from Koch's discovery of the cause of tuberculosis, which has already shown us the definite path which prevention must follow, and will certainly lead to further untold benefits to mankind. Similar inestimable results attend the discovery of the cause of typhoid fever and of cholera.

Isolation in the household and quarantine by gov-

* Investigations now pending into the inhuman treatment of patients va. Insane Asylums of New York City show that this perfectly preventable disease is very prevalent in at least one of these asylums, where the patientsreceive practically no vegetables or fruit in their dietary.

In the light of our definite knowledge of the cause of scurvy such a fact is an inexcusable instance of preventable sickness.

eminent have saved thousands of lives to the world; while the method of antisepsis in surgery is one of the great contributions of modern times to preventive medicine.

When all is said, however, it is only too evident that the work of preventive medicine has only begun, and that it is the duty of the physician to further its high aims in every possible direction, both by personal effort and by co-operating with official Boards of Health and other sanitary associations in extending the knowledge of the laws of health, and of the methods of preventing disease.

The personal work of the physician in enforcing these and in acting as a medium of communication of knowledge in his house-to-house visitations, is extremely important.

Nearly fourteen thousand persons died of phthisis in New York State in 1890, and about the same number in 1891.

It is undoubtedly true that a large proportion, if not all, of the cases which will undoubtedly result by infection from these persons, might have been prevented had the scientific facts regarding the spread and prevention of this disease been carefully explained by the physician in charge to the families in which these deaths occurred.

Similar opportunities for the prevention of infant mortality, and for giving advice regarding many other subjects connected with the physical and moral educalO MANUAL OF HYGIENE.

tion of the young, should be seized by the family physician.

But as personal influence is limited, this should be extended by membership in local sanitary associations, where these exist, and by efforts to form these or local Boards of Health where they do not exist. The function of siich boards is that of sanitary police, with full authority in matters of local or State hygiene.

They should also act as educators of the public, by the publication and dissemination of information concerning matters of public health. Certain State Boards of Health have contributed greatly to the scientific investigation of sanitary problems, notably that of Massachusetts, in the study of public water supplies, of Michigan, and others.

The recent action of the Michigan Board of Health, which was immediately followed by that of New York City, in regard to measures for the information of the public concerning the spread and prevention of tuberculosis, and also the work of the New York City Board of Health in the diagnosis of diphtheria by bacteriological analysis in the laboratory, are instances of educational and scientific work in two most important directions effected by State and local health organizations.

In order that the conditions which affect the health or disease of a community may be properly estimated, Boards of Health require the registration of various

Statistics and records concerning the sick; and the accumulation of such data forms the basis of Vital Statistics. Every physician can further scientific in- Testigation by making these returns when called for.

Boards of Health, however, are not maintained in their proper efficiency in every State, ^while in many towns they do not exist at all.

Moreover, conflict between such State Boards as to questions of sanitation which concern the safety of the nation at large are very possible, but would be highly ■detrimental to the public in times of emergency. In times of epidemics it has become very evident that the safety of the nation required an uniformity and promptness of action incompatible with the independent and often conflicting interests of widely distant State Boards. This is particularly the case in a country like America to whose shores several hundred thousand immigrants come every year, bringing with them, owing to their ignorance and filthy condition, numerous possibilities of disease, unless stringent measures of defense as exemplified in a vigorous quarantine be employed. The conditions of an epidemic have from time to time made the irregular defenses of our country in' this respect only too apparent.

These occasions have given rise to the opinion that some National system of supervision of the sanitary condition of the country should be introduced here as it has been abroad, which, without doing away with

State authority, should be free to render advice and. assistance to the country at large in times of emergency, and should at all times be a medium of communication between different States for diffusing sanitary knowledge, and stimulating local sanitation. The general scope of such a Bureau in the United States is indicated in the first section of a bill formulated by the New York Academy of Medicine (Jan.,. 1894), and now awaiting the action of Congress:

'' That the duties of the Bureau of Public Health shall be to collect and diffuse information upon matters affecting the public health, including statistics of sickness and mortality in the several States; the investigation by experimental and other methods of the causes and means of prevention of disease; the collection of information with regard to the prevalence of contagious and epidemic diseases both in this and other countries; the publication of the information thus obtained in a weekly bulletin; the preparation of rules and regulations for securing the best sanitary condition of vessels from foreign ports, and for the prevention of the introduction of infectious diseases into the United States, and their spread from one State into another^ which rules when approved by the President of the United States shall have the force of law ; the ascertaining by a suitable system of inspection that these rules and regulations are properly carried out and enforced;, the advising and informing the several departments of the government, and executives and health authorities

PRE VENTABLE DISEA SE. I 3

of the several States, on such questions as may be submitted by them to it ; or whenever, in the opinion of the Bureau, such advice and information may tend to the preservation and improvement of the public health ; and, in general, be the agent of the general government in taking such action as will most effectually protect and promote the health of the people of the United States."

CHAPTER II. Micro-organisms

The important role which micro-organisms play in nature, both beneficent and harmful, their direct relation to certain diseases, and their very wide distribution in the earth, make it essential that we should know the principal facts in the life history of these influential beings.

Classification, Structure, etc. — There are three general classes of micro-organisms, known as bacteria, yeasts and moulds. They are mainly classified according to their method of reproduction. The class which concerns our subject is that of the Bacteria. Bacteria are plants which belong to the lowest order of the vegetable kingdom, closely related to the algae. They are transparent cells, lacking, for the most part, chlorophyl, and are therefore unable to take up and appropriate carbon for their use as do higher plants. The bacteria are called fission-fungi, from their method of multiplying by division. Like higher orders of plants, however, bacteria grow and develop and generate their kind. They are widely distributed in the earth, air and water, and are particularly numerous in the habitations of men, on food, on the skin and

MICR 0- OR GA NISMS. I 5 "

clothing, in the mouth, nose, lungs and gastro-intestinal canal of men and animals.

Some bacteria are capable of producing coloring material of various kinds in the nutrient media. Some have the quality of phosphorescence.

In regard to shape, they are found in three forms, viz. : First, the spheroidal or egg-shaped bacterium, called micrococcus-, second, the rod-shaped, called bacillus; and third, the spiral-shaped, called spirillum. Some of the micrococci tend to cling together in pairs [diplococcus), or form little chains, which are called streptococci.

In size they are extremely minute. Fifteen hundred of them put end to end would scarcely reach across the head of an ordinary pin.

They are composed of granular protoplasm inclosed in a membrane or cell wall. Some of the bacteria have the power of spontaneous movement and under the microscope can be seen rolling and darting about. These movements are effected by means of tiny prolongations they possess, called fiagella (whipping threads). Figure i shows the three principal forms of bacteria, the appearance of a spore-bearing bacillus, and of the delicate flagella or whipping threads referred to.

The conditions necessary for their life in general are warmth, moisture, oxygen and a certain amount of organic matter. This organic matter they may find everywhere in nature — in the debris from animals and plants, in the earth, air and water. Oxygen is required in greater or less abundance according to their class. Those which grow and flourish in the presence of oxygen are called aerobic; those which can flourish without oxygen are known as anaerobic. Many bacteria can, however, if necessary grow under either condition, i.e. with or without oxygen.

By far the larger proportion of bacteria are harmless. Those which induce disease are known as pathogenic.

Fig. I. — Forms of Bacteria.

Micrococci. Bacilli. Spirilla.

Single and in chains. With and without With and without

spores. flagella.

Bacteria are also classified as saphrophytes and parasites : the former class including such as live entirely without the human body and exist only in the earth, air, etc., the parasites referring to those which can only live in the body of some animal. The majority of bacteria are saphrophytes. There are also semi-saphrophytic and semi-parasitic bacteria; i.e. those which while generally existing within the human body can yet maintain a separate existence for a while

MICRO-ORGANISMS. 1 7

external to it; or conversely, those whicli generally exist external to it and yet are able to maintain themselves for a while within the body of an animal. The term obligatory is used for parasites which can only live as such, facultative for such as can exist in either way.

The majority of bacteria thrive best at the ordinary temperature of a room or of the summer months, viz., 54° C. (68° F.). Most of the pathogenic bacteria develop best at 35-40° C. (85-102° F.); the bacillus tuberculosis, for instance, thrives best at a temperature of 37° C, which temperature must be constant for its growth. Cold is unfavorable to their activities. Many are killed by a freezing temperature, but experiments liave shown that many bacteria will resist for long periods the action of extreme cold; among these is the typhoid bacillus. Repeated freezings and thawings are shown to be most harmful to them. Light^ especially sunlight, kills after a time most of the pathogenic bacteria. They are all killed by a temperature of boiling water maintained for ten minutes.

Reproduction. Bacteria reproduce by (i) fission and by (2) spores. In the first process the membrane is seen to push inward and across the bacterium, making a partition which divides it into two. These two new germs may again speedily divide, and this process is practically continuous so long as the conditions are favorable. This fission is generally in one direction, occasionally in two places at right angles, forming the so- •called tetrad groups, sometimes in three divisions of space, forming the cubical or bale-like packets known as sarcinae. So rapid is this multiplication that it has been computed that a rod-like bacillus tijW of an inch long, might, if it could secure for itself favorable conditions, in five days multiply into a mass equal to all the oceans of the earth if one mile deep. But as a matter of fact these favorable conditions do not exists lack of food or other untoward circumstances terminating their career before this is possible.