101 
 
 P95d Frudden- 
 Dust and its dan- 
 
 University of California 
 
 At Los Angeles 
 The Library 
 
 Form L I 
 
 i 01
 
 This book is DUE on the last date stamped below 
 
 9 
 
 9/978 
 
 Form L-9-10m-3,'27
 
 DUST AND ITS DANGERS 
 
 T. MITCHELL PRUDDEN, M.D. 
 
 AUTHOR OF "A MANUAL OF PRACTICAL NORMAL HISTOLOGY," " THK 
 STORY OF THE BACTERIA," ETC. 
 
 G. P. PUTNAM'S SONS 
 
 NEW YORK LONDON 
 
 27 West Twenty-third Street 24 Bedford Street, Strand 
 
 Cbc "Knickerbocker prese 
 1899 
 
 3535
 
 COPYRIGHT 1890 
 BV 
 
 T. MITCHELL PRUDDEN, M.D, 
 
 8 3 13 T 
 
 Ube 'Knickerbocker press, Hew L'orfe 
 
 Electrotyped, Printed, and Bound by 
 G. P. Putnam's Sons
 
 OCR 
 
 101 
 
 PREFACE. 
 
 little book has been written with the 
 jL purpose of informing people, in simple 
 language, what the real danger is of acquiring 
 serious disease especially consumption by 
 means of dust-laden air, and how this danger 
 may be avoided. 
 
 It is an unpleasant subject ; but it is one 
 which every one must know something about if 
 he would avoid such physical ills as are much 
 more serious drawbacks to comfortable living 
 than are the temporary mental disquietudes 
 which this book is designed to inflict upon its 
 readers. 
 
 T. M. P.
 
 CONTENTS 
 
 CHAPTER PAGE 
 
 I. THE NATURE OF DUST IN GENERAL i 
 II. THE LIVING ELEMENTS OF DUST ; WHAT THEY ARE 
 
 AND WHERE THEY COME FROM .... 7 
 
 III. How THE LIVING ELEMENTS OF DUST ARE STUDIED . n 
 
 IV. THE MICRO-ORGANISMS OF OUT-OF-DOORS DUST . 20 
 
 V. THE MICRO-ORGANISMS OF IN-DOORS DUST . . 27 
 
 VI. THE SAFEGUARDS os THE BODY, AGAINST INHALEDS__ 
 
 DUST . . .. ' ..;*">: ... 36 
 
 VII. THE RE.AL SIGNIFICANCE OF DUST IN ITS RELATION 
 
 ^ TO DISEASE 50 
 
 VIII. CONSUMPTION AND THE WAYS IN WHICH IT is SPREAD 
 
 BY DUST 58 
 
 IX. DUST-DANGERS OUT-OF-DOORS AND IN PRIVATE 
 
 HOUSES, WITH SUGGESTIONS FOR THEIR AVOIDANCE 74 
 X. DUST-DANGERS IN PUBLIC BUILDINGS AND PUBLIC 
 
 CONVEYANCES 80 
 
 XI. SOME OBJECTIONS, PROTESTS, AND QUERIES AN- 
 SWERED 87 
 
 XII. SUMMARY AND CONCLUSION 99 
 
 INDEX , , , 105 
 
 vii
 
 ILLUSTRATIONS. 
 
 PAGE 
 
 PLATE I. Different forms of jnicro-organisms. To face . . 8 
 FIG. i A. A single " colony " of rod-shaped bacteria (bacilli) 
 growing on a plate of nutrient gelatine. The actual 
 diameter of this colony was about one fourth of an inch. 
 P>. A cluster of the bacilli taken from the colony and 
 highly magnified . . . . . . . 13 
 
 FIG. 2. The " plate method " of air analysis . . . .17 
 
 PLATE II. Colonies of micro-organisms growing on dust 
 
 particles. To precede .21 
 
 PLATE III. Showing results of " plate analyses" of the air of 
 
 different places in New York. To face . . . .24 
 PLATE IV. Effect of sweeping on the number of micro-organ- 
 isms in the air. To face ' 32 * 
 
 FIG. 3. Ciliated cells from the large air-tubes of the human 
 
 lungs, seen from the side 39 
 
 FIG. 4. Pigmentation of the lung from inhaled dust . . 44 
 
 FIG. 5. Dust filters in the lung deeply pigmented . . .47 
 FIG. 6. Lymph filters (lymph-glands) at the root of the lung, 
 
 ihe seat of local and healed tuberculosis .... 69
 
 DUST AND ITS DANGERS 
 
 CHAPTER I. 
 
 THE NATURE OF DUST IN GENERAL. 
 
 IF this were not a practical age, and if the 
 title on the back of this little book did not 
 fairly promise a reasonably practical theme, it 
 might be thought incumbent on the writer, 
 in this age of nice analysis of very small things, 
 to be explicit at the outset as to what he does 
 or does not mean when he says dust. For af- 
 ter all, when we think of it, there are a good 
 many kinds of dust. There is, for example, 
 molecular dust, which swaying ever in space 
 catches and breaks the sunbeams, giving us 
 now the deep blue of full day and again the 
 gorgeous colors of the earlier and later hours.
 
 DUST AND ITS DANGERS. 
 
 There are those masses of " water dust " which 
 we call clouds and fogs and steam. There is 
 the scriptural dust, bearing, according to ortho- 
 dox traditions, such a close relationship to the 
 origin arid endings of mundane existence. Col- 
 loquially, there is a form of "dust" too which to 
 win many a mortal seems to forget both his 
 origin and his destiny, yielding at last that dust 
 which he has won to be himself resolved into 
 that to which he was foreordained. 
 
 But if we plant our standard on Webster's 
 first choice, and let dust be for us " Fine dry 
 particles of earth or other matter so attenuated 
 that it may be raised and wafted by the wind," 
 we shall not be apt to stray too far from the 
 practical, nor fall foul of either primordial or 
 ecclesiastical or pecuniary dust. 
 
 Simple, common, omnipresent every-day dust 
 then, the bane of the tidy housekeeper, the 
 torment of the cleanly citizen who goes upon 
 the streets in ill-kept towns, wafted upon every 
 breeze without, stirred by every footfall within, 
 this is the humble but significant subject to 
 which, not without reason, it is believed, these 
 pages are devoted.
 
 DUST AND ITS DANGERS. 
 
 The dust particles of the air may be roughly 
 grouped in two classes first, those larger bodies 
 which are readily visible in-doors or out-doors, 
 and second, the smaller particles which are usu- 
 ally only seen when strongly illuminated. 
 
 The coarser particles of dust, such as are 
 usually swept into our faces whenever we go 
 upon the streets in New York in dry and 
 windy weather, consist largely of small frag- 
 ments of sand, broken fibres of plants, pollen, 
 fine hairs, the pulverized excreta of various 
 domestic animals, ashes, fibres of clothing and 
 other fabrics, particles of lime or plaster or 
 soot, parts of seeds of plants, masses and clus- 
 ters of various kinds of micro-organisms, and 
 other partially ground up materials of kinds 
 too numerous to mention. 
 
 The finer dust particles, whose presence, 
 when in considerable quantities, we may be 
 aware of by the choking sensation which they 
 cause when breathed in, even though we do 
 not see them, are most plainly visible as the 
 so-called "motes in the sunbeam," when sunlight 
 streams into more or less darkened places. 
 These are very light and consist of fragments
 
 DUST AND ITS DANGERS. 
 
 of fine vegetable or animal fibres, such as cot- 
 ton or woollen or other light material, and of 
 the greatest variety of micro-organisms, either 
 singly or in masses, such as bacteria and mould 
 spores. Furthermore, these micro-organisms 
 are very apt to be found clinging singly or 
 in clusters to the larger or smaller inorganic 
 particles of one kind or another which usually 
 make up the bulk of visible or invisible dust in 
 inhabited regions. 
 
 It is not necessary for our purposes here to 
 enter in detail into those conditions of soil and 
 climate and human occupation which favor the 
 presence of dust in the air. That dry air and 
 dry-ground surfaces and winds favor the distri- 
 bution of the fine particles which we call dust, 
 and that still air and moist ground tend to hold 
 it in check, are facts which every one's observa- 
 tion teaches. 
 
 It is well known that there are certain occu- 
 pations which confine persons to closed rooms 
 or places in which dust particles of one kind 
 or another are very abundant. Thus day after 
 day persons confined in air charged with coal- 
 dust or stone-dust or metallic-dust or cotton-
 
 DUST AND ITS DANGERS. 
 
 or woollen-dust or tobacco-dust, etc., are apt to 
 become victims of more or less well marked 
 pulmonary affections, which are to be found 
 fully described in systematic treatises among 
 the so-called " diseases of occupation." 
 
 It is not with these exceptional places nor 
 with the special conditions which belong to 
 them that we are now concerned, but with the 
 conditions under which both well and sick peo- 
 ple of all classes are placed, especially in cities, 
 and more particularly when in-doors. Nor 
 shall we occupy ourselves here to any consid- 
 erable extent with the inorganic ingredients of 
 dust, but more especially with those living 
 components called micro-organisms, be they 
 either bacteria or moulds. 
 
 I purpose, in the first place, drawing upon 
 the results of various old and recent studies, to 
 indicate the sources of the living germs which 
 form such an important part of the dust of in- 
 habited regions, the ways in which they get 
 disseminated in the air, and their general de- 
 portment as they are driven hither and thither 
 by the winds, sway poised in the still air of quiet 
 places, or settle slowly to the ground.
 
 DUST AND ITS DANGERS. 
 
 I purpose then to show the difference of 
 conditions which prevail, in-doors and out, and 
 the significance of these conditions in the 
 problems of ventilation and cleanliness. I 
 shall then give the results of a series of studies 
 of the atmospheric micro-organisms in various 
 places, and consider the relationship of these 
 aerial germs to some common forms of disease. 
 Finally, I shall suggest some of the measures 
 which must be adopted, both by the public au- 
 thorities and private persons, if both out-of- 
 doors and in-doors we are to have the privi- 
 lege of breathing clean and wholesome air. I 
 shall not, except incidentally, touch upon the 
 ordinary problems of ventilation or the numer- 
 ous ways in which by the accumulation of the 
 products of respiration and exhalation the air 
 of inhabited rooms may become an active 
 source of discomfort and ill-health, because the 
 means by which these evils may be avoided are 
 well known and are fully explained under the 
 heading of ventilation in text-books and treatises 
 on hygiene.
 
 CHAPTER II. 
 
 THE LIVING ELEMENTS OF DUST J WHAT THEY 
 . ARE AND WHERE THEY COME FROM. 
 
 ALL those forms of minute vegetable life 
 which swarm in myriads almost every- 
 where upon the earth's surface are called in 
 general micro-organisms or germs. Among 
 these there are three prominent forms which 
 are called bacteria, yeasts, and moulds (see 
 Plate I.). Among these the bacteria are by 
 far the most important. These tiny organisms 
 are for the most part so very small that many 
 thousands or millions of them clustered closely 
 together would not make a mass larger than 
 the head of a pin. Some of them are round 
 or ovoidal, some rod-like, some spiral (see 
 Plate I. Fig. 3). Most of them are harmless 
 to man, and serve a very important purpose 
 in the economy of nature in tearing asunder 
 
 7
 
 8 DUST AND ITS DANGERS, 
 
 dead and worn-out organic material and setting 
 it free in suitable condition for the building up 
 of new forms of life. A few species of bacteria, 
 however, are capable of causing some of the 
 most wide-spread and most dreaded of human 
 diseases. 
 
 The writer has in another book x described 
 in simple and untechnical manner the various 
 forms of bacteria and their relationship to man, 
 and to this he must refer the reader for fur- 
 ther details as to their nature and life history. 
 
 The moist surfaces of decaying vegetables 
 and plants and the bodies of animals, all solid 
 excreta of the bodies of men and animals, 
 human sputum, stagnant water, the surface of 
 the soil in inhabited regions, etc., afford fertile 
 fields of growth for myriads of micro-organisms 
 of one kind or another. 
 
 But we should always remember that bacte- 
 ria do not become detached from the surfaces 
 or materials on which they grow or are lodged 
 while these are in the moist condition. Even 
 the air sweeping in strong currents through 
 sewers whose watery contents and moist walls 
 
 1 " The Story of the Bacteria."
 
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 all portion of the common green riwuld (Penici 
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 'ria. Showing the little plants of various shap 
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 RMS OF MICRO-ORGANISMS. 
 
 
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 DUST AND ITS DANGERS. 
 
 may be swarming with bacteria does not be- 
 come charged with these. The bacteria, singly 
 or in masses, free, or attached to other par- 
 ticles of one kind or another, must first be 
 dried and then the clusters more or less pul- 
 verized or ground tip, before they are swept 
 away and suspended as a part of the dust in 
 the air. 
 
 There are indeed certain moulds the green 
 mould, for example, which is so common on 
 various moist articles of food which form 
 very light and not easily moistened spores (see 
 Plate I. Fig. i), these may be readily brushed 
 or blown off and mingle with the dust under 
 almost all conditions. 
 
 All sorts of bacteria-laden material then, 
 when dry and ground up as it so readily is 
 by the varied movements of men and animals 
 out-doors and in-doors, may become a part 
 of the floating dust. These dry minute germs, 
 some of which are alive and some dead, com- 
 port themselves in the air just as lifeless dust 
 particles of any other kind do. They are 
 wholly inert, and are driven hither and thither 
 by air currents, now in clouds or masses of al-
 
 10 DUST AND ITS DANGERS. 
 
 most stifling density, and again in very small 
 numbers, collecting in whirls and eddies, and 
 finally, always sooner or later, settling down to 
 the lowest available resting-place, as soon as 
 the buoyancy of air currents gives way to the 
 ever acting attraction of gravitation. Since 
 the bacteria of dust are very apt to be in little 
 groups or clusters or to cling to other dust par- 
 ticles, most of them readily settle, so that a 
 very considerable part, in fact, of the finer 
 dust the " motes in the sunbeam " is not 
 made up of bacteria or germs but of other 
 forms of lifeless matter.
 
 CHAPTER III. 
 
 HOW THE LIVING ELEMENTS OF DUST ARE 
 STUDIED. 
 
 HOW do we find out how many living- 
 germs there are and of what kinds in 
 a given volume of air ? It will suffice for our 
 purposes here to say that the bacteria are so 
 extremely small that the search for them as 
 they occur in nature is ordinarily of little avail 
 by the simple use of the microscope. 
 
 We have recourse in such studies to what is 
 called the " culture method." ' By this method, 
 instead of bringing a portion of fluid or of the 
 air in which we wish to seek for bacteria di- 
 rectly under the microscope, we mix a small 
 portion of the fluid or air with some material 
 which serves as food for the germs, and on or 
 in which they will readily grow. 
 
 1 See " The Story of the Bacteria." 
 
 ii
 
 12 DUST AND ITS DANGERS. 
 
 This food medium usually contains some 
 form of gelatine. The gelatinized material is 
 usually melted when the planting is being done, 
 and when it cools the bacteria are held firmly 
 in the position in which they lodged when they 
 were put in. 
 
 The bacteria placed under these conditions 
 multiply with such great rapidity that usually 
 in a short time the progeny of a single living 
 germ will have accumulated to such a degree 
 right in the spot where the germ lodged 
 that the mass of them, which we call a " col- 
 ony " will be readily visible to the naked eye, 
 or under a low power of the microscope (see 
 Fig. i). Now since we can readily see the 
 mass of bacteria which has grown where only 
 a single germ had lodged we have only to 
 count the colonies to know how many living 
 bacteria were present in the volume of air 
 or fluid which we have tested. 
 
 We can now, futhermore, subject the little 
 colonies which form our bacterial crop to a va- 
 riety of examinations and tests, and make out 
 what kinds there are, and further learn their 
 effects upon man or animals.
 
 DUST AND ITS DANGERS. 
 
 Now a good many plans have been devised 
 for finding out how many living germs are 
 present in a given volume of dusty air. We 
 
 Fig. i. A A single "colony" of rod-shaped bacteria (Bacilli) 
 growing on a plate of nutrient gelatine. The actual diameter of this 
 colony was about one-fourth of an inch. B A cluster of the bacilli 
 taken from the colony and highly magnified. 
 
 may force a given volume of the air through a 
 tube which has been plugged with cotton-bat- 
 ting previously heated so hot as to kill any
 
 14 DUST AND' ITS DANGERS. 
 
 germs which by chance have been upon it. 
 The cotton if properly packed in the tube will 
 catch and hold entangled in its meshes all the 
 dust particles no matter how small, and with 
 these all the bacteria which were in the air 
 which we force through the tube. If now we 
 carefully pull out the cotton plug with a pair 
 of perfectly clean forceps, and thoroughly rinse 
 it off in a small clean flat dish containing our 
 bacterial food which we call " the culture me- 
 dium," the germs will be distributed through 
 the medium, and we cover the dish and set it 
 aside in a warm place and let it stand until 
 each living germ has grown and multiplied till 
 it forms a visible colony. Now we count the col- 
 onies, and the number represents the number of 
 living germs which were present in the whole 
 volume of air which we forced through the cot- 
 ton plug. There are of course many details 
 and precautions against error which must be 
 observed, but this brief description will suffice 
 for our purposes here. 
 
 It has been found in practice, however, that 
 it is better to use fine sand than cotton in the 
 tubes to catch the germs, since this is more
 
 DUST AND ITS DANGERS. 
 
 easily handled and is equally efficient as a 
 filter. We plant the sand together with the 
 dust which it has caught in the melted culture- 
 medium, allow it to cool and then stand for a 
 few days, and when the colonies are grown they 
 are easily distinguished from the sand particles 
 by their shape, color, etc., and can be readily 
 counted. Or, we may use granulated sugar 
 for a "filter, which finally dissolves in the culture- 
 medium, leaving the bacteria to grow in due 
 time. This may be called the " filtration 
 method " of air analysis. 
 
 As it requires an accurate and somewhat 
 complex and cumbersome apparatus to force 
 or draw the air through either the cotton or 
 sand filter, another and simpler method is 
 often resorted to, which, though in some re- 
 spects less accurate, still gives very useful 
 results when we wish simply to compare the 
 germ ingredients of the air in one place with 
 those in another under similar general condi- 
 tions. 
 
 This simpler method consists in pouring into 
 a series of perfectly clean shallow glass dishes 
 a thin layer of the warm gelatinous culture-
 
 1 6 DUST AND ITS DANGERS. 
 
 medium and allowing it to solidify by cooling. 
 This gives a smooth, moist, somewhat adhesive 
 surface of equal size in each of the dishes, 
 which are immediately protected from any 
 chance contamination by closely-fitting glass 
 covers. 
 
 This mode of air analysis depends upon the 
 fact which we have mentioned above, and 
 which everybody is familiar with, namely, that 
 all dust particles, light or heavy, in quiet places, 
 slowly but surely settle towards the ground. 
 If now we set one of our covered dishes in a 
 still place and take off the cover, the dust 
 particles, the inorganic as well as the living, 
 will settle on to this moist nutrient surface. 
 With the inorganic components of the dust, the 
 multifarious shreds and patches of one thing 
 or another, this is the end of the matter. But 
 as the living dust particles touch the surface, 
 like Antaeus, they find their abeyant vigor 
 quickly renewed, and forthwith commence to 
 multiply and inherit their little new-found 
 earth. Now, suppose we leave our dishes un- 
 covered and exposed to the falling dust for, 
 say five minutes ; suppose further that the sur-
 
 DUST AND ITS DANGERS. 
 
 face of the culture-medium is three square 
 inches in size, it will be readily seen that by 
 the exposure of dishes of the same size for the 
 
 FIG. 2. THE "PLATE METHOD" OF AIR ANALYSIS. 
 
 The cut shows the appearance of the flat, shallow dish, the bottom 
 of which was covered with nutrient gelatin, and when this had cooled 
 and solidified, was uncovered and exposed to the air in a moderately 
 clean place for five minutes. It was then allowed to stand in a warm 
 place for four days. Immediately after the exposure of the gelatin 
 to the air nothing whatsoever was visible on its surface. But within 
 a few hours tiny spots appeared which grew larger, some more rapidly 
 than others. These " colonies," at the end of four days, when the draw- 
 ing was made, vary considerably in size and appearance, because they 
 are mostly made up of different species of germs. Each colony con- 
 sists of thousands of germs (see Fig. I, A), which have grown on the 
 spot where the lone ancestor fell from the air and stuck fast during 
 the five minutes exposure of the gelatin. 
 
 same time to the air of different places, we 
 can, by comparing the number of bacterial
 
 1 8 DUST AND ITS DANGERS. 
 
 colonies which develop on the surfaces, get at 
 least an approximate idea of the relative num- 
 ber of suspended bacteria slowly settling in the 
 air of the different places (see Fig. 2). 
 
 We cannot, of course, by this method say 
 how many germs were present in a given vol- 
 ume of air, as we can by the more elaborate 
 and accurate method given above, and there 
 are many minor sources of error. For exam- 
 ple, the mould spores are so very light and 
 buoyant that they fall but slowly, so that we 
 may altogether miss many of them, and the 
 same may be true of some of the lighter bac- 
 teria. Moreover, even very slight upward air 
 currents may interfere with the settling of the 
 germs, and in windy places .this method is of 
 little use. But on the whole, if similar condi- 
 tions are maintained in the different analyses, 
 comparative results may be obtained in this 
 way which are of much value, as we shall pres- 
 ently see. 
 
 This, which we will call the "plate-method," 
 enables us to get a general notion of the bac- 
 terial contents of the air in various places under 
 conditions which would render the use of the
 
 DUST AND ITS DANGERS. 1 9 
 
 more accurate and cumbersome apparatus dif- 
 ficult or impracticable. We can go about with 
 our innocent-looking little case of glass boxes, 
 partly filled with nutrient gelatin, as does the 
 amateur photographer with his detective cam- 
 era ; though insteadr of " pulling the string, 
 touching the button, and leaving the rest to 
 the manufacturer," we raise the cover, take the 
 time* and let Nature do the rest. 
 
 We are now ready to look at the results of 
 a series of so-called biological analyses of the 
 air of various places. We mean by biological 
 analysis of air, in distinction from the chemical, 
 an analysis which has for its object the deter- 
 mination of the number or character, or both, 
 of the living germs, or micro-organisms which 
 may be suspended in it.
 
 CHAPTER IV. 
 
 THE. MICRO-ORGANISMS OF OUT-OF-DOORS DUST. 
 
 WE must be on our guard in looking at 
 the results of such analyses as those 
 now to be described against hasty inferences 
 as to their significance. It would be a grave 
 mistake to suppose that living germs in the 
 air are necessarily harmful to human beings, 
 and to infer that air found to habitually con- 
 tain few bacteria is necessarily more salubrious 
 than that which contains more. For the pres- 
 ent, then, let us look upon the results of these 
 analyses simply from the biological standpoint, 
 and, if possible, place ourselves in the attitude 
 of botanists studying the flora of the atmos- 
 phere, not of physiologists concerned with the 
 relationship of these tiny plants to man. This 
 we shall come to by and by when we have ac- 
 cumulated enough facts to justify such infer- 
 ences as may urge themselves upon us.
 
 EXPLANATION OF PLATE II. 
 
 This cut shows the appearances which are presented, %fter the 
 germs have grown, by particles of sand and shreds of vegetable fibre 
 to which single germs were clinging when they settled on to the un- 
 covered gelatin plate. In this case the drawing was made five days 
 after the exposure of the plate to the air of a dusty street. The largest 
 of these colonies were barely visible to the naked eye. 
 
 I. Shows a particle of sand completely surrounded by the colony 
 or mass of bacteria which has grown from a single germ which was 
 clinging to the minute sand particle as it settled with the dust. 
 
 2. Shows a tiny shred of wood to which five different germs were 
 attached as it settled on to the exposed plate. We should probably 
 have searched in vain, even with a powerful microscope, for the single 
 germs clinging to it at the time this wooden dust particle planted itself 
 on the surface of the gelatin. But now the larger colonies are visible 
 even to the naked eye. We know that they grew from different 
 species of germs because under a moderate magnifying power they 
 present such markedly different appearances. 
 
 3. Shows a minute sliver to which four different forms of germs 
 were clinging as it fell.
 
 DUST AND ITS DANGERS. 21 
 
 From the enormous number of bacteria and 
 moulds, which are present everywhere in in- 
 habited regions where the conditions are suit- 
 able for their growth, it might be imagined 
 that in dry weather the number of atmospheric 
 germs in the dust' out-of-doors would be very 
 great. But this is not usually the case, even 
 in large and populous towns. Here and there 
 along the streets, where these are filthy and 
 almost never properly cleaned, as in New 
 York, or where the wind whirls around the 
 corners of buildings, forming air eddies, the 
 micro-organisms are often present in very large 
 numbers, so that one in passing about the town 
 is apt here and there to encounter veritable 
 germ-showers. But on the whole, almost 
 everywhere out-of-doors, except in dangerously 
 filthy cities, the large volumes of air, which are 
 more or less constantly passing, so largely di- 
 lute the local germ-dusty air that the actual 
 number of micro-organisms in a given volume, 
 say a cubic foot, is on the average very small, 
 and usually insignificant. When the ground 
 is wet and air currents moderate, the number 
 of germs is still further diminished.
 
 22 DUST AND ITS DANGERS. 
 
 It is very difficult to fix upon any definite 
 number of living micro-organisms in the out- 
 of-doors air which can be regarded as the usual 
 or normal number, because the number varies 
 so extremely under different conditions. Thus 
 on high mountains or deserts and on the sea 
 the unconfined air is practically free from 
 micro-organisms. In the winter months, when 
 snow is on the ground, during rain storms, and 
 when the air is still, the number may be very 
 small. On the other hand, a high wind blowing 
 across a region rich in dry and pulverized 
 germ-laden material, will for a time disseminate 
 large numbers of micro-organisms ; but at the 
 same time it tends, by the dilution which it 
 affords, and by carrying them off to other re- 
 gions, to speedily reduce the numbers in any 
 given place. A rainfallrto a certain extent, 
 tends to free the air of its germs by washing 
 them down, while during a snowstorm many 
 are caught in the snow crystals as they form. 
 
 In wet weather mould-spores tend to pre- 
 dominate, partly because they then grow readily 
 and partly because they are very light, and not as 
 easily wetted and held down as are the bacteria.
 
 DUST AND ITS DANGERS. 2$ 
 
 The analysis of out-of-doors air shows, as 
 might be expected, a great deal of variation 
 in the number of living germs present in a 
 given volume. Ten litres, which is about 600 
 cubic inches (that is a volume equal to a cube 
 of about 8 inches square), is the volume of 
 air usually taken as a sample for purposes of 
 analysis. 
 
 Carnelly found in still out-of-doors air, in 
 the town of Dundee, in Scotland, as the result 
 of 14 analyses, an average of less than 10 
 bacteria in 10 litres of air, while in another 
 place there were over 1 70 in the same volume. 
 
 Tucker found the air in Boston, from a 
 secluded place, but in the immediate vicinity 
 of its traffic, during the mild but rather windy 
 weather in November, December, and January, 
 with no snow on the ground, to contain on the 
 average of 56 analyses, less than 20 bacteria to 
 10 litres. In an open court at the Hygienic 
 Institute in Berlin, Petri found, as a rule, 
 equally small numbers. 
 
 The average of 13 analyses, made in March 
 and April, 1 890, of the air from the yard of the 
 College of Physicians and Surgeons, in New
 
 24 DUST AND ITS DANGERS. 
 
 York, at a place as far from the streets as pos- 
 sible, and about 25 feet from the ground, showed 
 the number of bacteria in 10 litres to be 56 and 
 of moulds 4. 
 
 Analyses, during the same period, of the air 
 of the streets in New York, from various parts 
 of the town, 1 showed the average number of 
 bacteria in 10 litres to be 376, and of moulds 
 6. These analyses of street air were made 
 under ordinary conditions, at such times of the 
 day as the air appeared to be at its best. . 
 
 If an analysis is made of the air in the dust 
 clouds which sweep along the ill-kept streets 
 of a city like New York or which blows from 
 the street sweepers as they pass along the 
 unwatered thoroughfares into the houses or 
 over the unwary passer-by, the numbers of 
 germs to the litre is startling. 
 
 Let us look at a graphic record of the rela- 
 tive number of bacteria in various places, made 
 by the plate method already described. 
 
 Plate III. shows the result of a series of 
 Comparative analyses made in this way in var- 
 
 1 This was at a time when the so-called politicians were juggling 
 with the Street Cleaning Department while the streets were largely 
 left to take care of themselves.
 
 PLATE III. SHOWING RESULTS OF " PLATE ANALYSES " OF THE AIR 
 
 OF DIFFERENT PLACES IN NEW YORK. 
 
 (See explanation in the text.)
 
 DUST AND ITS DANGERS. 2$ 
 
 ious places in New York on a clear, dry, mod- 
 erately breezy day, in April, 1890. Each one 
 of the spots represents a colony of bacteria, 
 which has grown from the single germ which 
 settled on to the moist surface during the five 
 minutes exposure to the air. 
 
 1. Ball Ground, Central Park. A mod- 
 erate westerly wind bringing dust over from 
 the Eighth Avenue and its cross streets. 
 
 2. Union Square. At the edge of the 
 fountain basin. 
 
 3. The library of a private house not far 
 from 34th Street and Broadway. 
 
 4. A large retail dry-goods store on one of 
 the uptown cross streets near Broadway, during 
 a busy hour of the day, when there was much 
 stir and bustle. 
 
 5. Railing of the small park at Broadway 
 and 35th Street. 
 
 6. A cross street through which the carts of 
 the Street-Cleaning Department were passing 
 collecting the dry heaps of street dirt. 
 
 If we translate into numbers the appearances 
 of the cultures shown in Plate III., we find that 
 during five minutes the number of living germs
 
 26 DUST AND ITS DANGERS. 
 
 which settled from the floating dust on to the 
 bottom of a round dish about 3f inches in 
 diameter in different places in New York was 
 as follows : 
 
 1. Central Park. Dust blowing from an 
 adjacent street, 499. 
 
 2. Union Square, 214. 
 
 3. Private house, 34. 
 
 4. Large retail dry goods store, 1 99. 
 
 5. Broadway and 35th Street, 941. 
 
 6. Street in the process of being cleaned, by 
 the Street-Cleaning Department, 5,810. 
 
 A sufficient explanation of the number of 
 germs in the air at the lower part of Central 
 Park is found in the westerly wind and the ex- 
 tremely filthy condition of the streets on the 
 windward side. The result of the analysis 
 shown in fig. 6, needs no lengthy comment. 
 That as many living germs as of colonies 
 which are here seen growing should be float- 
 ing in the air and liable to be breathed in by 
 any unfortunate passer-by within five minutes, 
 is evidence enough of the filthiness of the 
 present practices of so-called street-cleaning in 
 New York, As to its danger, more by and by e
 
 CHAPTER V. 
 
 THE MICRO-ORGANISMS OF IN-DOORS DUST. 
 
 WHEN we consider the comportment of 
 dust particles in closed rooms, we see 
 at once that the great renovating and cleansing 
 agency which is so efficient out-of-doors is, ex- 
 cept on special occasions, absent, namely, the 
 winds and strong air currents and the more or 
 less frequent and prolonged wettings. Once 
 in a closed room dust is very apt, as every 
 housekeeper knows, to stay there, unless \ 
 special means are resorted to to get rid of it. ' 
 But although the dust remains in the room, 
 those heavier parts of it which contain most of 
 the bacteria gradually sink to the lowest 
 available levels, floors, shelves, furniture, etc., 
 so that it has been found that the still air of a 
 room may almost completely free itself from 
 micro-organisms, except some of the lighter 
 27
 
 28 DUST AND ITS DANGERS. 
 
 mould spores, within one or two hours. Of 
 course violent currents of air, walking about, 
 etc., interfere with the very complete subsi- 
 dence of the bacteria-laden dust particles. 
 
 Now it might be supposed that the frequent 
 renewal of the air of a room by such a system 
 of ventilation as would be effective in keeping 
 its gaseous ingredients pure would also suffice 
 to rapidly carry off dust particles, and bacteria 
 as well. But a long series of most carefully 
 conducted experiments by Stein has shown 
 that "this is not the case. Even when the in- 
 troduction of fresh air is pushed to the com- 
 plete renewal of the air three times an hour, 
 the number of suspended micro-organisms 
 floating in the air is scarcely more diminished 
 than they would be by settling in still air. 
 Stein found that only when the ventilation 
 was carried to the degree of inducing marked 
 and disagreeable draughts in the room was 
 there a rapid diminution in the number of 
 micro-organisms which had been diffused arti- 
 -ficially through the air for the purposes of the 
 test. Of course opening of the windows and 
 allowing large bodies of air to blow through
 
 DUST AND ITS DANGERS. 29 
 
 the room, quickly resulted in sweeping away a 
 large proportion of the suspended micro-or- 
 ganisms. But this observer also found that 
 even very strong air currents were not able, 
 when sweeping over woollen and other fabrics, 
 carpets, hangings, etc., which had been be- 
 strewn with bacteria-laden dust, to free the 
 germs to any considerable extent from these. 
 The 'strong air currents carried off the sus- 
 pended particles, but those which had settled 
 on to the fabrics and floors were but little 
 affected. The practical bearings of this ob- 
 servation we shall see by and by. 
 
 When we consider the constant tendency of 
 dust particles to settle as soon as they find 
 themselves in quiet places out of strong air 
 currents, and the fact that even ordinarily 
 efficient systems of ventilation do not carry off 
 any considerable proportion of the dust par- 
 ticles from closed still rooms, we are led to the 
 rather startling conclusion that the ordinary 
 living-rooms, even though they be well ven- 
 tilated, are actually dust and bacteria reposi- 
 tories, and that when by a system of forced 
 ventilation we cause large volumes of dust-
 
 3O DUST AND ITS DANGERS. 
 
 laden air from, out-of-doors to pass through 
 them we are actually, so far as micro-organisms 
 are concerned, cleansing the air and sending it 
 out much freer from germs than when it en- 
 tered, these having slowly settled as the air 
 made its way from the entrance to the exit of 
 the ventilating openings. The same of course 
 applies, though in a less striking way, to the 
 so-called natural mode of ventilation that is 
 a ventilation system which has for its exit a 
 warm air-shaft or chimney, and " trusts to 
 luck " for channels of air entrance through 
 loose joints in windows, doors, and walls. 
 
 Now, although in rooms through which for 
 purposes of ventilation large volumes of dusty 
 out-of-doors air are pumped, day and night, 
 there will be in the aggregate a considerable 
 accumulation of more or less bacteria-laden 
 dust, it is, after all, the ground-up dirt which 
 we bring in from the streets upon our shoes 
 and garments, and the accumulations of waste 
 material, which in dwelling-houses and places 
 of assembly are so abundant, which furnish the 
 larger proportion of the bacterial ingredients 
 
 of in-doors air. The marked difference be- 
 3
 
 DUST AND ITS DANGERS. 31 
 
 tween the atmospheric dust in closed rooms 
 and that out-of-doors is that in the former 
 there is no spontaneous mode of purification 
 of the air except that of settling, and that the 
 settled more or less bacteria-laden dust is 
 liable to frequent stifring-up by the ordinary 
 movements of people, while out-of-doors the 
 bacteria-laden air is constantly being swept off 
 by the wind. 
 
 The effect of stirring about in rooms in 
 which micro-organisms are present is shown by 
 the analyses of Tucker in the wards of the 
 Boston City Hospital. He found that about 
 midnight after the wards had been quiet for a few 
 hours, the number of living bacteria in 10 litres 
 of air ranged from o to 13, while the number of 
 mould spores ranged from o to 4. The air had 
 practically freed itself from germs, by settling 
 to floors and beds. He found that in a long 
 series of hourly determinations in various wards 
 at all hours of the day, the average number of 
 bacteria in 10 litres of air was about 26 and of 
 moulds about 12, the number of bacteria rang- 
 ing from i to 477; of moulds from o to 227. 
 The germs were more abundant in the air in
 
 32 DUST AND ITS DANGERS. 
 
 the forenoon when the beds were being made 
 and the wards cleaned and put in order. He 
 found that sweeping nearly doubled the number 
 of germs in the air already disturbed by the 
 routine work in the wards in the morning, and 
 considering the number of germs in the 10 
 litres of air in the early morning before the 
 wards were astir as the minimum i the 
 general cleaning routine work and sweeping 
 were capable of increasing the number, on the 
 average, seventy times. 
 
 The difference in the number of living germs 
 floating in the air of a room before and after 
 sweeping, is graphically shown in Plate IV. 
 The room in which these analyses were made, 
 was a most carefully kept hospital ward in New 
 York, in which were about 25 persons. Be- 
 fore the sweeping, when quiet had prevailed 
 for about an hour, the number of living germs 
 which settled on to the dish, 3^ inches in di- 
 ameter, was 12 (see Plate IV., Fig. i). Im- 
 mediately after sweeping, the number which 
 -settled on to a similar surface, was 226 (see 
 Plate IV., Fig. 2). Very much larger differ- 
 ences are often found in the number of germs
 
 DUST AND ITS DANGERS. 33 
 
 in the air before and after sweeping, if the 
 rooms are not frequently carefully and properly 
 swept and dusted. Thus in a carpeted living- 
 room in a tenement on loth Avenue, 75 bacteria 
 and i mould settled on to the surface of the 
 exposed plate in five minutes before sweeping. 
 When the room was still, immediately after 
 sweeping, a similar experiment showed over 
 2,700 bacteria and 6 moulds. 
 
 Carnelly found in hospital wards in Dundee 
 in the afternoons from 10 to 20 bacteria in 10 
 litres of air. Neumann found after sweeping 
 from 80 to 140 bacteria, and later in the day 
 from 4 to 10 in 10 litres. On the other hand, 
 Carnelly found in houses which are denomin- 
 ated clean, 180 bacteria in 10 litres of air, 
 while in very dirty houses there were over 
 900. In dirty school-rooms, with the so-called 
 natural ventilation, he found in the same vol- 
 ume of air nearly, 2,000 living bacteria, while 
 in mechanically ventilated schools there were 
 from 30 to 300. 
 
 The writer has found as the result of 23 
 analyses of the air of various laboratories, 
 lecture-rooms, and hall-ways, at the College of
 
 34 DUST AND ITS DANGERS. 
 
 Physicians and Surgeons in New York, under 
 the ordinary conditions of occupation by con- 
 siderable numbers of students during March and 
 April, 1 890, that the average number of bacteria 
 in 10 litres was n and of moulds 14. 
 
 The average number of germs in various 
 hospitals and dispensaries in New York during 
 the same period in 10 litres of air, (19 analyses) 
 was bacteria 127, moulds 25. 
 
 We thus see that the number of living germs 
 in a given volume of in-doors air varies greatly 
 in different places and under different con- 
 ditions. We see that the temporary freeing of 
 the in-doors air from germs can be accomplished 
 by simply closing the rooms and keeping the 
 contained air still when within one or two 
 hours nearly all dust and most of the bacteria 
 will have settled to the lowest resting-place. 
 Whether the air shall be permanently rid of its 
 living or inert dust particles or not, will of 
 course depend upon the measures which are 
 resorted to in the familiar performances of 
 sweeping and dusting, of which more by and by. 
 
 A good many of these facts which have been 
 just set down in regard to dust, are embodied
 
 DUST AND ITS DANGERS. 35 
 
 in the lore of the intelligent house-keeper, 
 scientific studies having simply given precision 
 to common beliefs and revealed certain quali- 
 ties in dust, which may possibly render it of 
 greater significence than an annoying and an 
 omnipresent form of dirt.
 
 CHAPTER VI. 
 
 THE SAFEGUARDS OF THE BODY AGAINST IN- 
 HALED DUST. 
 
 HAVING now gathered together a con- 
 siderable number of facts about the 
 distribution in the air of dust particles and 
 among them of living germs, we are ready to 
 consider their significance if they have any 
 to human beings, who must live in and breathe 
 this more or less dust-laden air. 
 
 The average amount of air which a healthy 
 grown person takes in at each breath has been 
 estimated to be about one half a litre (about 
 30 cubic inches). We have seen from our 
 various analyses of the air of different places in 
 and about New York, under ordinarily favor- 
 able conditions, that the number of living 
 germs in 10 litres of air varies from 1 1 to 376. 
 So that basing our estimate upon these studies 
 36
 
 DUST AND ITS DANGERS. 37 
 
 of the air in this city, with every twenty 
 breaths one may take into his body, depending 
 upon where he is all the way from n to 376 
 living micro-organisms, together with a variable 
 amount of inorganic dust. 
 
 The number of living germs which the New 
 York citizen is liable to be forced to take into 
 his body, when the streets are dry and the 
 wind blowing, or when the dry filth is being 
 stirred up by the diabolically careless proceed- 
 ures of the present street-cleaning fiends, it 
 would be a thankless task to tell. 
 
 Now it has been learned, not only from com- 
 mon experience but from long series of careful 
 experiments, that the solid particles which we\ 
 breathe in with the air either through the nose 
 or mouth do not come out with the expired air, 
 but are retained on the moist surface upon ' 
 which the air impinges going in and coming 
 out. These foreign particles floating in the 
 inspired air are caught largely in the nose or 
 mouth or upper throat, while a certain number 
 pass down into the air-tubes and lungs. A 
 large part of this foreign material may be dis- 
 charged from the nose where it is caught in the
 
 38 DUST AND ITS DANGERS. 
 
 mucous which that organ secretes when irri- 
 tated. 
 
 A very considerable proportion of the in- 
 breathed foreign material gets into the mouth 
 and may be spat out or swallowed. 
 
 The floating material which is carried past 
 the well-guarded portals of the lungs and 
 enters the windpipe and bronchial tubes and 
 lodges on their moist walls finds here a most 
 efficient arrangement for its expulsion. Here 
 is placed, completely lining the tubes, an army 
 of thoroughfare-cleansers composed of individ- 
 uals who are not in politics, who have no vote, 
 and who present to us the unwonted, and at 
 first puzzling, spectacle of street-cleaners whose 
 business seems to be to clean the streets. 
 Completely lining the larger air-tubes like 
 a mosiac, are myriads of tiny cells shaped 
 something like a narrow short club and set 
 upon end side by side. Projecting from the 
 free ends of each one of these cells is a number 
 of very minute hairs, so that the whole cell 
 looks something like a short club with a beard 
 growing from one end (see Fig. 3). The 
 whole inner surface of these air-tubes, then, is
 
 DUST AND ITS DANGERS. 
 
 39 
 
 lined with these delicate hairs which are called 
 cilia. 
 
 Now, these myriads of cilia, year in and year 
 out, day and night, while life lasts, are con- 
 stantly swinging their free ends back and forth, 
 bending as they recover, and then with a quick 
 
 FIG. 3. CILIATED CELLS FROM THE LARGE AIR-TUBES OF THE 
 HUMAN LUNGS, SEEN FROM THE SIDE. HIGHLY MAGNIFIED. 
 
 snap forward so that any small object which 
 lodges on the walls of the larger air-tubes 
 since all the cilia act in rhythm is swept up- 
 wards toward the mouth, away from the peril- 
 ously delicate and sensitive lungs. 
 
 The movement of these cilia is less vigorous 
 when the body is quiet, as in sleep, increasing
 
 40 DUST AND ITS DANGERS. 
 
 in rapidity and force when the body is active. 
 Almost every one has noticed that shortly after 
 rising more or less mucus or " phlegm " is apt 
 to come up into the throat. This is because the 
 increasing vigor of the ciliary movement, as 
 one's general activity increases, sweeps up the 
 accumulation which the comparative quiescence 
 of the night has allowed to form. 
 
 It is a curious thing that these humble but 
 energetic little members of the cell communi- 
 j ties which make up the body are apparently the 
 I last elements to die when what we sometimes 
 call the vital forces no longer act. The breath 
 ceases, the heart flutters and is still, the blood 
 ebbs and flows a little here and there, the last 
 definite nerve impulses express themselves as 
 now one now another muscle quivers or feebly 
 and fitfully contracts, but still these wonderful 
 little cilia keep swinging on sometimes for 
 hours after all trace of what we have called 
 life has disappeared, and when these too at 
 last are still, and not till then, is life in the 
 body totally extinct. 
 
 There is another very curious arrangement 
 in the air passages for the disposition of small
 
 DUST AND ITS DANGERS. 41 
 
 foreign bodies which are breathed into the 
 lungs. There are certain cells in the body 
 which seem to have nothing in particular to do 
 on ordinary occasions but to float about on the 
 blood tides or wander through the various 
 channels and crevices of the tissues watching 
 other cells work. Sometimes they come out 
 and air themselves in the bronchial tubes or in 
 the tiny air-chambers which make up the body 
 of the lungs. But the moment these cells 
 come upon a foreign particle from without or 
 upon a fragment of worn-out tissue anywhere 
 in the body they pounce upon it, wrap them- 
 selves around it, and either digest or destroy 
 it or carry it off to some safe place of deposit, 
 either inside the tissues or without. Now these 
 humble scavenger cells are usually quite abun- 
 dant in the air passages, where they often take 
 up dust particles of one kind or another, and 
 victims to their zeal are not infrequently swept 
 with their booty by the ciliated cells up and 
 away into the mouth. A good deal of lore has 
 accumulated about these little wandering scav- 
 engers of the body and they seem to be of great 
 importance in many ways. But, in spite of
 
 42 DUST AND ITS DANGERS, 
 
 their usefulness and the various beneficent 
 things which they do, scientific men have seen 
 fit to make them bear the added burden of the 
 name of phagocytes. 
 
 But to return to our dust particles. In spite 
 of all the safeguards with which our lungs are 
 furnished against the entrance of foreign 
 bodies, into their deep and delicate recesses 
 and through them into the blood, a considerable 
 number of dust particles of one kind or another 
 do get in and permanently lodge upon those 
 walls of the delicate breathing chambers in the 
 lungs, which are beyond the protecting agency 
 of the ciliated cells. Now right in the walls 
 of these tiny air-chambers of the lungs, where 
 the blood is separated from the inbreathed air 
 only by a film, one of the most important and 
 subtle of the vital process goes on, upon which 
 the continued purity and virtue of the blood 
 depends. Here the blood gives up the car- 
 bonic acid and water which it has gathered in 
 its journey around the system, and takes in its 
 "fresh supplies of oxygen. 
 
 Although persons who habitually work in 
 very much dust-laden air are liable to pul-
 
 DUST AND ITS DAGGERS. 43 
 
 monary disease caused by the lodgment in 
 their lungs of foreign particles of one kind or 
 another, and furthermore, although even com- 
 paratively small amounts of foreign particles in 
 the lung tissue cannot fail to be undesirable 
 additions to those organs, still it is a fact that 
 the lungs do establish for themselves a consid- 
 erable degree of what we call tolerance of for- 
 eign particles lodged in their tissues. That is 
 to say, there may be a good deal of accumula- 
 tion of foreign material in the lungs without 
 any appreciable interference with the health, 
 because the body here, as in many other ways, 
 has the power of adapting itself to unusual and 
 even harmful conditions. 
 
 In fact, the lungs of nearly all adults who live 
 under what we call civilized conditions, that is, 
 in houses with considerable smoke and dust in 
 the air, in cities which have street-cleaning done 
 for political purposes only, or in manufacturing 
 regions where there is much smoke, instead of 
 being of a delicate spotless pink color are dotted 
 all over with spots and streaks and patches of 
 inhaled dust-particles which the body has not 
 been able to get rid of but has stowed away
 
 44 
 
 DUST AND ITS DANGERS. 
 
 permanently in the tissues in such situations as 
 will least interfere with the action of the lungs 
 (see Fig. 4). Here it remains as long as life 
 lasts. 
 
 t 
 
 FIG. 4. PIGMENTATION OF THE LUNG FROM INHALED DUST. 
 
 A small portion of the surface of an adult human lung which has 
 become pigmented by the inhalation of dust. This drawing was 
 made not from the lung of a coal miner or one who had lived in 
 especially smoky or dusty places, but from that of an individual ex- 
 posed to the ordinary conditions of in-door city life. 
 
 But we have not yet finished with the safe- 
 guards which the body has placed for itself 
 against inhaled dust. For, however success-
 
 DUST AND ITS DANGERS. 45 
 
 fully the lungs may stow it away in consider- 
 able quantities, there is a very curious provision 
 against its further entrance to and distribution 
 in the body. This is the way that is provided 
 against. As the blood circulates through the 
 lungs as well as in every other part of the body, 
 a small amount of its fluid part, conveying an 
 abundance of nutriment, oozes out through the 
 walls'of the vessels into all the minute clefts and 
 crannies of the tissues where the cells lie and 
 bathes and nourishes them. Now, having done 
 this, the nutritive fluid which we call lymph 
 is gradually collected into a series of irregular 
 narrow vessels which open into large and still 
 larger trunks until finally it is poured back into 
 the blood, of which it again becomes a part. 
 
 If this lymph which has searched out every 
 remotest corner of the body to which it was 
 distributed should have become contaminated 
 or polluted by any harmful or foreign material 
 which it had come across in the tissues, it would 
 carry it straight back and pour it into the blood, 
 where it might cause dire results, since the 
 blood is an extremely important and delicate 
 juice. But fortunately the lungs, as well as
 
 46 DUST AND ITS DANGERS. 
 
 several other important organs of the body, are 
 provided with a series of very efficient filters, 
 through which the lymph has to pass in its 
 transit toward the blood current with which 
 it is to mingle. Now several of these living 
 filters, which we call " lymph-glands," little 
 reddish-white bodies, are grouped deep in the 
 chest at the root of the lungs, and are so 
 very effective that, although the lungs may 
 be crowded with inhaled dust particles stored 
 away permanently in out-of-the-way places, and 
 the lymph filters may finally become themselves 
 as black as your hat from its accumulation 
 (see Fig. 5) the dust rarely gets through them 
 and into the blood or other parts of the body. 
 
 Thus far, in considering the safe-guards of 
 the body against inhaled dust, we have been 
 thinking only of those lifeless particles of one 
 kind or another which make up the inorganic 
 part of dust. How is it with bacteria, with 
 those dust particles which are quite inert when 
 ~dry in the dust, but which, when the moisture 
 and warmth and food they need are furnished, 
 may grow and multiply with great rapidity.
 
 DUST AND ITS DANGERS. 
 
 47 
 
 In answer to this, it should be said that not 
 only does the body afford the same safe-guards 
 against these living germs as against other 
 dust particles, as just described, but most of 
 the different kinds of germs which are floating 
 
 FIG. 5. DUST FILTERS IN THE LUNG DEEPLY PIGMENTED. 
 
 A drawing of one lobe of a human lung, showing the lymph filters 
 (lymph-glands) at one side, which have caught so much inhaled dust 
 in their meshes thus keeping it out of the blood as to have become 
 almost totally black. These glands are naturally of a light-pink color. 
 
 in the air do not grow in the human body in 
 any appreciable degree ; the soil is not good 
 for them. Some do not find in the nose, or 
 the mouth, or the lungs, the proper food or 
 conditions which they need, others are actually 
 killed off sooner or later, either owing to some
 
 48 DUST AND ITS DANGERS. 
 
 quality in the body juices which is quite in- 
 imical to their life, or by those vigilant phago- 
 cytes which we have noticed above or per- 
 haps in other ways which we do not yet know 
 any thing about. The germs which are swal- 
 lowed after being caught in the nose or mouth 
 from the inspired air, or swept up from the air- 
 tubes by the ciliated cells, are, for the most 
 part, soon deprived of life by the digestive 
 fluids. 
 
 There is one species of bacteria which we 
 are to learn more about presently (the tubercle 
 bacilli) which, when they lodge in the tissues, 
 sometimes stimulate the cells near them which 
 multiply and build up a dense enclosing wall 
 about the intruding germs, so that these be- 
 come imprisoned in a little bag or sac in the 
 body, and can neither get away, nor spread, nor 
 do further damage. They are sometimes so 
 cut off from nutriment, that they die, ,or at 
 best sustain for some time, a poor and meagre 
 existence. (See Fig. 6, p. 69.) 
 
 There are individual conditions of the body 
 in which it affords a most obstinate resistance 
 to the incursions that is, the growth of bac-
 
 DUST AND ITS DANGERS. 49 
 
 teria within it. There are other conditions in 
 which it seems fairly predisposed to their 
 growth and ravages. What the nature of the 
 conditions is, which in one individual or at one 
 time confers immunity to harmful bacterial 
 growth, and at another renders it predisposed 
 to their ravages, we do not know. But very 
 zealous workers are busy with the problem, and 
 we may hope in due time to get light and con- 
 fidence in this obscure field, where we can now 
 but feebly grope.
 
 CHAPTER VII. 
 
 THE REAL SIGNIFICANCE OF DUST IN ITS RELA- 
 TION TO DISEASE. 
 
 BUT why then, it may be asked, all these 
 sinister allusions to the danger of dust, 
 if, as we have seen in the last chapter, most of 
 it is caught before it gets into the lungs, and 
 that which does get in is disposed of in such 
 clever ways ? This question brings us at last 
 face to face with the gist of the whole matter. 
 The body does rid itself of a great deal of the 
 inhaled inorganic dust which lodges in the nose 
 and mouth and air-tubes of the lungs. It does 
 do the best it can to dispose of that which is 
 permanently stowed away in the lung tissues 
 themselves. It does without more ado kill out- 
 right or otherwise make way with most of the 
 living germs. But when all this is accomplished 
 there still remain certain important ways in 
 50
 
 DUST AND ITS DANGERS. 51 
 
 which dust particles of one kind or another 
 may do serious harm to human beings. 
 
 We shall do well in considering these 
 harmful effects of dust to separate in our 
 thought its inorganic from its germ ingredi- 
 ents. 
 
 The inorganic elements of dust when present 
 in la,rge quantities in the inhaled air may, as 
 we have seen above, cause well-defined disease 
 of the lungs by the persistent irritation which 
 they induce. But as it is only under excep- 
 tional conditions, as among coal-miners and 
 grinders and other workers in confined places 
 where these solid particles are set free in great 
 numbers that this occurs, we need not con- 
 sider them here. Very moderate amounts 
 of dust particles in sensitive persons cause 
 such a degree of irritation of the respiratory 
 organs as either to deprive them of robust 
 health or predispose them to the aquirement 
 of various diseases which with unirritated 
 lungs they would readily resist. 
 
 There is no doubt that a great deal of 
 misery, if not positive disease, is caused by the 
 inhalation of dust in the persistent coughs and
 
 52 DUST AND ITS DANGERS. 
 
 more persistent protean catarrhs with which 
 so many persons otherwise healthy are bur- 
 dened. 
 
 Then again dust may produce much distress 
 when not inhaled, by irritating the eyes to such 
 a degree as to cause great discomfort, if not 
 positive disease. 
 
 The pernicious and noxious elevated rail- 
 roads have brought some parts of New York 
 into a condition very much akin to certain 
 coal mines, with the large amounts of dust and 
 fine cinders which they shower down upon the 
 streets and into the adjacent houses and into 
 the eyes and lungs of the pitiable citizens 
 of this metropolis. 
 
 As to the bacteria about which our main in- 
 terest centres, there are unfortunately a few 
 species which, when they once find lodgement 
 in one place or another in the organs of 
 respiration, may grow and multiply, and .suc- 
 cessfully resisting all the protective agencies of 
 the body, set up distinct, persistent and even 
 fatal disease. Those forms of bacteria which 
 can or in these regions commonly do this, are 
 insignificant in number in comparison with the
 
 DUST AND ITS DANGERS. 53 
 
 harmless species with which dust is usually 
 swarming. But few as they are they have an 
 extreme significance. If it were not for these 
 few species of disease-producing bacteria most 
 people could perhaps afford to be as indifferent 
 as they are to dust and its dangers. 
 
 We have seen that the large numbers of 
 common bacteria which are omnipresent in the 
 air are growing all about us and get into the 
 dust in many ways which we not only cannot 
 control but do not very much care to control, 
 since in moderate numbers they are essentially 
 harmless, or at least do only such damage as 
 other inorganic dust particles may do. But 
 with the bacteria which cause disease the case 
 is entirely different. They do not flourish 
 apart from the bodies of men and animals. 
 They may remain alive for a good while out- 
 side of the body, and some of them may grow 
 a little under some few special conditions. 
 Some of them are frequently present in the 
 healthy human body. 
 
 But after all when we seek for the active 
 breeding-places and sources of distribution of 
 the bacteria which frequently cause disease in
 
 54 DVsT AMD JTS 
 
 man in this region, we find that they are the 
 bodies of persons, and occasionally animals, 
 suffering from the diseases which the bacteria 
 cause. It is the presence of these bacteria in 
 large numbers given off from the body, which 
 makes these diseases what we call contagious 
 or infectious. 
 
 If we could completely isolate all those per- 
 sons or animals who are at the present moment 
 harboring the few known species of bacteria 
 which produce disease in man, such diseases 
 could be completely stricken from the list of 
 human ills, unless they were lighted up afresh 
 by some of the discharged material which on 
 walls, or garments, or in the soil, or in the 
 aerial dust, still retained vitality. At any rate, 
 if we could be certain that the discharged 
 material from such sick people were immedi- 
 ately destroyed we should be able to limit 
 within narrow bounds those diseases which to- 
 day carry off, prematurely, the larger part of 
 those who do not die of injuries or of old age. 
 They are thus, at least ideally, preventible 
 diseases. 
 
 But this matter of preventing the spread of
 
 DUST AND ITS DANGERS. 55 
 
 bacterial disease by means of dust is of such 
 extreme importance that we must be very cer- 
 tain that we are dealing with facts and not with 
 conjectures, when we consider the relationship 
 one to the other. Let us then get the facts 
 together first. 
 
 There is a large number of diseases which 
 physicians call infectious ; these all have cer- 
 tain ways of manifesting themselves, certain 
 family traits which would justify this grouping 
 of them together even without a knowledge of 
 the particular agent which causes them. The 
 more important of these infectious diseases 
 are : consumption or tuberculosis, diphtheria, 
 small-pox, yellow-fever, Asiatic cholera, ty- 
 phoid-fever, scarlatina, measles, pneumonia, 
 erysipelas, and blood-poisoning. There are 
 others of less frequent occurrence in this re- 
 gion, which we need not mention here. 
 
 Now within the past few years we have found 
 out positively and without question that the 
 particular and exclusive agent which causes 
 some of these diseases is one or other form of 
 bacteria. Each disease has its special form of 
 bacteria, without which it can by no possibility
 
 56 DUST AND ITS DANGERS. 
 
 exist. The particular species causing some of 
 these diseases have been isolated and studied 
 and experimented upon in so many ways and 
 by so many workers that we feel perfectly cer- 
 tain about them. Among such diseases are : 
 consumption, typhoid-fever, Asiatic cholera, 
 erysipelas, some forms of blood-poisoning, and 
 diphtheria. 
 
 Concerning the kinds of germs which cause 
 many other of the infectious diseases we are 
 yet in doubt. We have an increasing convic- 
 tion that they are also caused by some form of 
 micro-organism or germ, but what it may be 
 and how it acts is not fully determined. 
 
 Among those infectious diseases the exact 
 causes of which have not yet been made out 
 may be mentioned small-pox, yellow-fever, 
 measles, and scarlatina. 
 
 Now to make a long story short, and to give 
 precision to our theme, I purpose to limit this 
 consideration of the relationship of dust to 
 disease largely to that one bacterial malady 
 which is most important and which we know 
 most about and which we can do most to pre- 
 vent, namely, consumption or tuberculosis.
 
 DUST AND ITS DANGERS. 57 
 
 Many of the conclusions to which we shall 
 be forced, and many of the practical hints as 
 to personal action which we shall gain, apply 
 equally to some of the other bacterial diseases. 
 But these other diseases are apt to make peo- 
 ple early and more or less seriously ill, and so 
 they come under the charge of the physician, 
 who^ should on the spot suggest measures to 
 prevent their spread. On the other hand, per- 
 sons affected with consumption very frequently 
 go about for weeks and months among their 
 fellows, always liable, through ignorance or 
 carelessness, to transmit the disease-producing 
 germs to others, as well as constantly repoi- 
 son themselves, and thus greatly diminish the 
 chances of recovery which they might other- 
 wise anticipate. 
 
 It is most important then that everybody 
 should have some definite knowledge about 
 the cause and mode of spread of consumption, 
 since it spares no age and no class and is the 
 most widespread and fatal of all the diseases 
 known to man, and is in large degree, could 
 we but secure thorough cleanliness in the air 
 we breathe and the food we eat, a distinctly 
 preventible disease.
 
 CHAPTER VIII. 
 
 CONSUMPTION AND THE WAYS IN WHICH IT IS 
 SPREAD BY" DUST. 
 
 THE germ which causes consumption or 
 tuberculosis is a minute slender rod-like 
 body about one ten-thousandth of an inch in 
 length, and is called the Bacillus tuberculosis. 
 It does not grow in nature outside of the bodies 
 of men and a few species of warm-blooded 
 animals. It may, however, remain alive for 
 a long time when dry as in the soil or air. 
 
 In the bodies of some animals and in the 
 bodies of many men it does not ordinarily 
 flourish or even grow at all, for reasons which 
 we do not understand. The proper tempera- 
 ture may be present and moisture and nutritive 
 material in abundance, but for some unknown 
 reason it will not grow. There are other in- 
 dividuals and other animals which seem to 
 58
 
 DUST AND ITS DANGERS. 59 
 
 furnish the unknown conditions, and in them 
 the bacillus grows more or less rapidly ; such 
 persons or animals are said to be predisposed 
 to the disease consumption. 
 
 A great deal of misery and wearing appre- 
 hension have been caused in the years which are 
 past by the widespread notion that consump- 
 tion < may be inherited. Modern researches 
 show that this notion is not well-founded. It 
 is true that there is a subtle make-up of the 
 body cells in certain persons, some entirely 
 mysterious nutritive condition, which renders 
 their bodies especially favorable for the growth 
 of the tubercle bacillus, and that this indefinite 
 and ill-understood peculiarity may be inherited. 
 But that is all. If the tubercle bacillus can 
 be kept away from them, even predisposed 
 persons cannot get consumption, for this dis- 
 ease without the bacillus cannot exist, and the 
 bacillus does not as far as we know pass from 
 the mother to the unborn child. But this so- 
 called predisposition is not always inherited; 
 it may be and often is acquired, sometimes in 
 ways which we know about, sometimes in ways 
 which we do not fully understand.
 
 60 DUST AND ITS DANGERS. 
 
 When the tubercle bacilli get into the bodies 
 of predisposed individuals and begin to grow 
 they stimulate the tissues about them so that 
 little new-formed masses of cells appear about 
 and among the growing germs. These cell 
 masses are called tubercles. Sometimes larger 
 masses of new cells are developed, which re- 
 place considerable portions of the tissues and 
 organs in which the bacilli have lodged. After 
 a time, especially in the lungs, the new-formed 
 tissue, containing sometimes enormous num- 
 bers of the living tubercle bacilli, gradually 
 disintegrates or breaks down, and this broken- 
 down germ-laden material may then be dis- 
 charged with the mucus from the bronchial 
 tubes day after day in considerable quantities 
 for months or even years, in the expectoration, 
 new bacilli forming as fast as the old are dis- 
 charged and sometimes even much faster. 
 
 Tuberculosis may have its seat in other parts 
 of the body than the lungs, but with the lung 
 affection alone we are now concerned. 
 ' This then is the great primary fact which is 
 of extremest significance to us in our present 
 study ; namely, that every person suffering
 
 DUST AND ITS DANGERS. 6 1 
 
 from cons^tmption of the kings may be expector- 
 ating every day myriads of living and virulent 
 tubercle bacilli, and that the life and virulence 
 of these bacilli are not destroyed by prolonged 
 drying. 
 
 Now leaving this fact for a moment, let us 
 see how common a disease consumption or 
 tuberculosis is after all. 
 
 From one seventh to one fourth of all the 
 people who die are carried off, most of them 
 prematurely, by this disease. In Europe about 
 one million persons die each year from con- 
 sumption, that is about 3,000 every day. In the 
 United States in the year 1880, that is, the 
 year of the last census, over 91,000 persons 
 fell victims to this disease, and the average age 
 at death of these persons was thirty-seven. 
 Let him who has watched the progress of this 
 insidious disease in but a single case, imagine 
 if he can the misery and pain which these fig- 
 ures represent. 
 
 The disease is considerably less frequent in 
 some regions and countries than in others, but 
 everywhere where men live together in large 
 numbers, or live under bad sanitary conditions
 
 62 DUST AND ITS DANGERS. 
 
 in-doors, this disease claims its numerous vic- 
 tims when once it gains a foothold. 
 
 Our attention is not ordinarily called to the 
 large numbers of persons who sicken and die 
 from consumption, because we have become so 
 accustomed to it that it is taken as a matter of 
 course, one of the inevitable ills of life. When 
 yellow-fever or small-pox or Asiatic cholera 
 threaten to spread among us, we are on our 
 guard at once, and from the medical profession 
 and the press come such warnings that no 
 pains are spared in public or in private to stay 
 their progress. And yet the number of victims 
 of these occasional and dramatic epidemics is 
 quite insignificant as compared with those of 
 our omnipresent consumption. 
 
 We dread outbreaks of small-pox and care- 
 fully guard ourselves against its spread, but in 
 the State of Michigan, which is typical of 
 many others, in 1886-87 there were from forty 
 to fifty times as many deaths from consump- 
 tion as from small-pox. In the State of New 
 York in 1887 there were reported 96,453 
 deaths, and 11,609 f these were from con- 
 sumption.
 
 DUST AND ITS DANGERS. 63 
 
 A glance over the mortality in various cities 
 in different parts of the world, as it comes to 
 us in the very latest reports, shows everywhere 
 the same story. We find in Dr. Tracy's report 
 to the Health Department of New York City 
 for the week ending March 22, 1890, that in 
 New York City, out of 772 deaths from all 
 causes, 121 were from consumption. In Chi- 
 cago, out of 2,072 deaths, 178 were from con- 
 sumption. In London, out of 1,889 deaths, 
 206 were from consumption. In St. Peters- 
 burg, out of 617 deaths, 128 were from con- 
 sumption. In Paris, out of 1,214 deaths, 248 
 were from consumption. In Vienna, out of 470 
 deaths, 116 were from consumption. In Berlin, 
 out of 650 deaths, 96 were from consumption. 
 
 These are the bald relentless records of the 
 deaths. But who shall adequately picture, or 
 even remotely conceive, the shattered ambi- 
 tions, the long weary hours of distress and 
 suffering and struggle, the slow weeks and 
 months, lighted fitfully now and then by gleams 
 of fictitious hope, which lead to the last long 
 release. And what shall be said of the deso- 
 lated homes and scattered families, and pov-
 
 64 DUST AND ITS DANGERS. 
 
 erty and want and crime which among the 
 poor are wont to cluster about and to follow 
 such premature and lingering death ? Probably 
 the actual suffering and distress caused by all 
 other diseases put together is far less than 
 that which in one way or another is associated 
 with consumption. 
 
 Now where do all these people get this most 
 widespread disease ? How do they become 
 infected ? Where do the living bacilli of this 
 particular species 'come from which get into 
 their bodies ? They do not grow at the tem- 
 perature of the air out-of-doors. There are no 
 lurking-places for them in nature apart from 
 those men or animals who have the disease. 
 Plant them artificially with other common bac- 
 teria in tubes in the laboratory and they die ; 
 they succumb in the struggle for existence 
 with the harmless species of the earth and 
 water and air. 
 
 In a certain number of cases they no doubt 
 are taken in with the food, and inasmuch as 
 "tuberculosis of cattle is a very common disease 
 all about us, there is every reason for believing 
 that the infection often enough occurs through
 
 DUST AND ITS DANGERS. 65 
 
 the use of uncooked meat or milk. That the 
 consumptive mother may infect the nursing 
 child with its food has been abundantly proven. 
 There are cases in which the tubercle bacilli 
 get into the blood and are distributed to all 
 parts of the body, setting up such innumerable 
 foci of disease that the individual soon suc- 
 cumlps to the violence of the poison. 
 
 But after all, the prevailing seat of consump- 
 tion being in the lungs, the most natural 
 supposition is that the larger proportion of 
 consumptive people become infected through 
 the inhaled air. 
 
 Now, as has been absolutely proven over 
 and over again, in almost all populous regions, 
 both out-of-doors and in-doors, tubercular per- 
 sons may be discharging thousands of living 
 tubercle bacilli every time they spit out mate- 
 rial from their lungs upon the streets, or upon 
 the floors, or wherever it can dry and mingle 
 with the dust. If the tubercle bacillus is not 
 easily killed by drying, as has been fully proven, 
 have we not a sufficient explanation of the way 
 in which the infection of tuberculosis becomes 
 so widely and perpetually spread?
 
 66 DUST AND ITS DANGERS. 
 
 If this be true, that tuberculosis is spread 
 by the breathing in of tubercle bacilli in the 
 dust of the air, then, it may be said, we ought 
 to be able to find these particular germs in 
 the dust of rooms inhabited by consumptives. 
 This is by no means an easy task, because our 
 means of identifying this germ are rather com- 
 plex, and require for their execution much time 
 and skill. But notwithstanding this, Cornet, 
 in Berlin, has over and over again, in the dust 
 high up on the walls of consumptive wards of 
 hospitals, in the dust of private houses, and 
 hotel rooms occupied by consumptive patients, 
 found living virulent tubercle bacilli. But he 
 found these only in cases in which the dis- 
 charged sputum was not carefully and at once 
 destroyed, but was permitted to lodge upon 
 floors or clothing or articles of furniture, where 
 it dried and finally became pulverized and car- 
 ried as dust to such parts of the room as are 
 not ordinarily cleaned. 
 
 Again, some one will say : " If it be true that 
 consumption is apt to be acquired by breathing 
 in of the bacilli with the dust, then we ought 
 to find in the lungs of persons who have died
 
 DUST AND ITS DANGEKS. 6? 
 
 from other diseases not infrequently the com- 
 mencements of tuberculosis." Now this is in 
 fact just what we do find. It is very common, 
 indeed, to find in those little filters at the root 
 of the lung, the lymph-glands which we have 
 spoken of in another chapter, both in adults 
 and in children small areas of tubercular dis- 
 ease, and nothing else in the whole body indi- 
 cating the presence of the germ. The disease 
 here has not been extensive enough to cause 
 any ill effects or give any symptoms. It may 
 be in an early stage or it may have existed for 
 a long time, or it may have altogether healed, 
 leaving only its unmistakable traces behind 
 (see Fig. 6). 
 
 But more than this, even, we have learned 
 about the early stages of this disease. Dr. H. 
 P. Loomis has in several cases of accidental 
 death in apparently healthy persons examined 
 these lymph filters (lymph-glands), and found 
 them in appearance perfectly healthy, and yet 
 on applying one of the most delicate and effec- 
 tive tests, has found that after all they did, in 
 a considerable proportion of the cases exam- 
 ined, contain living tubercle bacilli. These
 
 68 DUST AND ITS DANGERS. 
 
 were present, but had not yet set up even a 
 local disease. 
 
 It has been shown, by a careful series of re- 
 cent observations, that when due care and 
 intelligent cleanliness are provided for, the at- 
 tendants upon consumptives in hospitals and 
 in private houses, are not subject, in any 
 marked degree to the acquirement of the dis- 
 ease. But, on the other hand, it has been 
 equally fully proven that when proper cleanli- 
 ness is not exercised, and the expectoration of 
 the patients not intelligently cared for, the 
 attendants in hospitals for consumptives have 
 in very large proportion fallen victims to the 
 disease. 
 
 More proof than is in our hands is hardly 
 needed that in a very large proportion of cases 
 in inhabited regions the infection or germ of 
 tuberculosis is conveyed from sick to well per- 
 sons by means of the material discharged from 
 the lungs, which is allowed, from carelessness 
 or ignorance, to dry and finally mingle with the 
 floating dust. 
 
 While thus tuberculous persons may be a 
 constant source of danger to their healthy fel-
 
 DUST AND ITS DANGERS. 
 
 lows, it is by no means true that they always 
 are or ever need to be. The breath itself, the 
 
 FIG. 6. LYMPH FILTERS (LYMPH-GLANDS) AT THE ROOT OF THE 
 LUNG, THE SEAT OF LOCAL AND HEALED TUBERCULOSIS. 
 
 Two of the lymph filters at the root of the lung which have 
 become blackened from inhaled dust. But in addition to this, one 
 of them the larger shows two white spots which are caused by 
 the lodgment here of the tubercle bacilli. These germs, caught in 
 the meshes of the filter and thus kept out of the blood, have grown 
 here for a time. But owing to their growth or their presence, the tissues 
 about them have been so stimulated or irritated, that a dense organ- 
 ized wall has been formed around the germs, completely shutting them 
 off from the rest of the body. This is the way in which the cure of 
 consumption is sometimes effected. Nowhere else in the body of this 
 person, who died from an acute disease, were there any evidences 
 whatsoever of tuberculosis.
 
 7O DUST AND ITS DANGERS. 
 
 exhaled air of consumptives, no matter how 
 seriously ill, is not dangerous ; it carries no 
 germs. It is only the solid discharged mate- 
 rial of the sputum which carries the danger. 
 And this sputum, moist and usually adherent 
 as it is when fresh, is only dangerous, so far as 
 contamination of the air is concerned, when it 
 is permitted to dry. 
 
 Here we seem to be at the root of the evil. 
 The reason why consumption is so widespread 
 and the most important element in this appall- 
 ing mortality is simply that consumptive per- 
 sons, either from ignorance or carelessness, are 
 distributing the poison not only everywhere 
 they go, but everywhere the dust goes which 
 has been formed in part by the undestroyed 
 germ-laden material expelled from their lungs. 
 This is what has been mistaken for so many 
 years as evidence of the hereditary transmis- 
 sion of consumption, as proof that consumption 
 " runs in families." The house-mates have 
 unwittingly poisoned one another, usually, no 
 doubt, through the dust. We are but just be- 
 ginning to recognize this. We have, indeed, 
 known what caused consumption but a very
 
 DUST AND ITS DANGERS. 
 
 few years, and even many intelligent physi- 
 cians are not yet sufficiently impressed with 
 the inexpressible importance of scrupulous 
 cleanliness in tuberculosis to urge it as they 
 should. 
 
 The way, then, to most efficiently stop the 
 prevalence of this distinctly preventable dis- 
 ease is evidently to see that the sputum of 
 consumptives is properly disposed of. When 
 this is practicable it should be received in 
 small paper cups, 1 made for this purpose, and 
 as soon as possible burned. The reception of 
 the sputum upon fabrics of any sort is always 
 to be deprecated. 
 
 The reason why the use of cloths or hand- 
 kerchiefs for the reception of the expectoration 
 in consumption should be as much as possible 
 avoided is that on these the material very 
 readily dries, and, becoming detached with or 
 without the minute particles of fabric, readily 
 floats off in an inhalable condition into the air. 
 For the same reason, great care should be 
 exercised by consumptives to avoid the soiling 
 by sputum of woollen garments from which 
 
 1 These are now in the market and sold cheap by druggists.
 
 72 DUST AND ITS DANGERS. 
 
 very fine fibre particles are always very 
 readily detached, and would carry with them 
 dried particles of germ-laden material, should 
 such have been allowed to fall upom them. 
 
 But if cloths must be used, as will often be 
 the case, either to receive the expectoration or 
 for wiping the mouth, they should be such as 
 can be as speedily as possible burned with 
 their contents. When handkerchiefs are used 
 they should be as early as possible boiled for a 
 full hour in a receptacle by themselves before 
 they are washed in the ordinary way. Cheap 
 paper cuspidores are now made which should 
 be placed in all apartments frequented by con- 
 sumptives, and frequently changed and with 
 their contents burned. 
 
 The greatest drawback in the suggestion of 
 such rules of procedure as would be efficient in 
 preventing the spread of tuberculosis is the 
 certainty that they will not, in a great many 
 cases, be followed. Persons who are cleanly 
 enough in private houses will spit upon the 
 street, or in public conveyances, or on the 
 floor of theatres and other places of assembly, 
 and until the knowledge that the sputum of
 
 DUST AND ITS DANGERS. 73 
 
 consumptive persons may be dangerous shall 
 have become widespread, our efforts in the di- 
 rection of the prevention of this disease will 
 continue to be counteracted by the misdeeds 
 of the ignorant and careless. 
 
 Consumption is at best, if it has any best, a 
 most distressing and deplorable malady. But 
 when we have learned, as we have within the 
 last decade, that the chances of recovery are 
 often very good indeed ; that it is not hopeless, 
 as was formerly believed ; that it is not in- 
 herited ; when we appreciate that with due 
 care the stricken one need not in the least be 
 a source of danger to others, even to his house- 
 mates ; when we fully realize that the appalling 
 prevalence and mortality of the past has been 
 due to ignorance of the nature of the disease 
 and the mode of its transmission, we should be 
 able to appreciate how much we owe of com- 
 fort and of hope to the investigations in 
 scientific medicine, which have given us all 
 this, if they have not yet brought to us such 
 means as will directly cure the disease in 
 individuals when once firmly established.
 
 CHAPTER IX. 
 
 DUST-DANGERS OUT-OF-DOORS AND IN PRIVATE 
 
 HOUSES, WITH SUGGESTIONS FOR 
 
 THEIR AVOIDANCE. 
 
 WITH all these facts about the most 
 common way in which consumption is 
 transmitted from one to another before us, we 
 are ready to consider what the places are in 
 which healthy persons are most likely to be 
 forced to breathe air which contains this or 
 other infected dust, and what should be done 
 to avoid it. 
 
 It should always be held in mind, in con- 
 sidering the facts and suggestions which this 
 chapter contains, that the safeguards of the 
 body against inhaled germs, which we have 
 already looked at in another chapter, are 
 constantly in action, and in large degree, in 
 many persons, actually and wholly protect 
 
 74
 
 DUST AND ITS DANGERS. 
 
 against danger, even in very dirty and very 
 infectious places. Many disease-producing bac- 
 teria soon die, in greater or less numbers, soon 
 after they are expelled from the bodies of sick 
 persons ; many are swept away by the winds 
 into uninhabited regions ; many fail to come 
 in contact under favorable conditions with 
 susceptible human beings. But these natural 
 safeguards cannot be implicitly relied upon 
 for safety by any one at all times, nor can 
 any one with impunity overtask their capaci- 
 ties by unnecessary and constant exposure of 
 his person to infectious dust. 
 
 It is certain that in the out-of-doors air in the 
 country, and also in cities whose streets are 
 kept decently clean, there is little danger of 
 harm from the inhalation of germs of con- 
 sumption or of any other disease, because the 
 constant purifying agency of wind and air 
 currents will either soon sweep away the dust 
 or so largely dilute it that it will be practically 
 free from disease germs, the sources of which 
 are so comparatively limited. If, however, the 
 streets of cities be or are allowed to remain 
 filthy, so that abundant and pretty constant
 
 76 DUST AND ITS DANGERS. 
 
 dust-clouds are encountered by those passing 
 through them ; if the streets are not properly 
 sprinkled before sweeping, either by machine 
 or hand ; if ignorant or careless street-cleaners 
 are allowed to scatter clouds of dust about 
 them as they sweep or shovel or transport the 
 pulverized filth, the chances of inhalation of 
 dangerous dust particles are proportionally 
 increased. But, on the whole, the risk of 
 infection out-of-doors from dust, even in 
 crowded towns, unless they are notably filthy, 
 is not actually very great. 
 
 Indoors, however, the conditions are en- 
 tirely different. Let us first consider private 
 houses and living rooms. Here, as we have 
 already seen, the sources of micro-organisms 
 are various, but we need consider here only 
 those which cause consumption. These may 
 be brought in on feet and garments from the 
 streets or other places, or be blown in through 
 open windows or drawn in by other modes 
 of ventilation. If there be no consumptive 
 persons in the house or rooms, these chance 
 sources of infection are all that need be re- 
 garded. If there be consumptives in the
 
 DUST AND ITS DANGERS. 77 
 
 rooms, no further danger need be feared if 
 the material which they expectorate be scru- 
 pulously attended to in the manner already 
 indicated. If, on the other hand, consump- 
 tives are permitted to discharge the material 
 raised from the lungs on floors or elsewhere 
 where it may dry, this will be a source of dan- 
 ger far exceeding all others. In houses where 
 healthy persons are, then, or in houses where 
 consumptives are who are intelligently clean 
 in their habits, the chances of inhaling the 
 tubercle bacilli are slight. But it should al- 
 ways be remembered that these chances, 
 whether small or great, are directly dependent 
 upon the means which are used to get rid 
 of the dust. If this be permitted to accumu- 
 late so that it is liable to be stirred up over 
 and over again by the movements of persons 
 in the room, by so much will the risks be 
 increased of inhaling the harmless germs of 
 dust and with them sooner or later, the dan- 
 gerous ones, should such by chance be present. 
 It is perfectly obvious that unless the win- 
 dows be widely open or liberal air currents in 
 some way established, the too common method
 
 78 DUST AND ITS DANGERS. 
 
 of so-called "dusting" that is, the stirring up 
 of the dust which has settled on the smooth 
 places in a room so as to allow it to settle 
 again on to the rough surfaces or inconspicu- 
 ous places where it does not show is worse 
 than useless, since the dust and germs are not 
 in this way got rid of, but only redistributed 
 and put for a time in a situation suitable for 
 inhalation. 
 
 Carpets and heavy hangings and upholstery 
 with rough goods all insure the more or less 
 persistent retention of dust particles in rooms 
 and with these the harmful germs, if such are 
 present. 
 
 Hard floors, with rugs which may be cleaned 
 out-of-doors, as few and as light hangings 
 as are practicable, furniture upholstered as far 
 as may be with smooth-surfaced fabrics, the 
 use of moist dusting-cloths, and the wide open- 
 ing of windows and doors when cleaning is 
 going on, these are the general suggestions, 
 which, if followed, will confer in a large degree, 
 even in populous towns, a sense of security 
 against the dangers of dust in private houses 
 in which healthy persons live. 
 
 We need here only call attention in the
 
 DUST AND ITS DANGERS. 79 
 
 briefest way to many devices in the lore of 
 the enlightened housekeeper for cleaning of 
 carpeted floors without raising clouds of dust 
 which seem more objectionable the more we 
 know about them. Such practices as the sprink- 
 ling of carpets with coarse salt, or salt and bran, 
 or moist tea-leaves, or other substances which 
 keep down the dust : the use of some of the 
 more perfect forms of carpet-sweepers, etc., 
 may be brought to bear in solving the prob- 
 lem of clean living places in towns. 
 
 The writer can perhaps imagine the fine 
 scorn with which his meek suggestions in this 
 direction may be met by the experienced 
 housekeeper, and indeed makes no virtue of 
 insisting upon method so long as the removal, 
 and not the simple redistribution of the dust, 
 be the end accomplished. 
 
 In houses and larger buildings which are 
 supplied with a system of forced ventilation, or 
 wherever the ventilation-draught is strong 
 enough, a great deal may be accomplished in 
 the way of keeping the dust out of the buildings 
 by the use of cheese-cloth or thin cotton batting 
 screens placed across the air currents near the 
 entrance of the ventilation-shafts.
 
 CHAPTER X. 
 
 DUST-DANGERS IN PUBLIC BUILDINGS AND PUBLIC 
 CONVEYANCES. 
 
 WE come now to another class of places 
 in which dust is a matter for very seri- 
 ous consideration. I mean theatres, churches, 
 schools, and court-rooms and other places of 
 assembly in-doors where large numbers of per- 
 sons are frequently crowded together. Here 
 the individual in the matter of the cleanliness 
 of the air he breathes is largely at the mercy 
 of his fellows, and especially of the persons 
 too often ignorant and careless to whom is 
 intrusted the more or less frequent sweeping, 
 dusting, or other cleaning of the rooms. 
 
 So prevalent is consumption, and so insidi- 
 ous in its onset that there are very few large 
 assemblages in which some victims of the dis- 
 ease are not present. Such persons, if not 
 
 8q
 
 DUST AND ITS DANGERS. 8 1 
 
 informed of the danger of the practice, will be 
 apt to convey some of the material discharged 
 from the lungs to situations in which without 
 care and vigilance on the part of those who 
 afterwards clean the rooms, it may form a part 
 of inhalable dust. 
 
 Many of the theatres are probably the most 
 likely places of any which we know frequented 
 by healthy persons in large cities for the inha- 
 lation of disease germs of one kind or another, 
 especially the germ of tuberculosis. The ven- 
 tilation is usually wholly inadequate even for 
 the purpose of carrying off the vitiated air of 
 respiration or exhalation, and is of almost no 
 use in freeing the air of dust. Close walled 
 they are apt to be, so that large volumes of 
 out-door air rarely or never sweep through 
 them, carpeted and the chairs upholstered in 
 plush, visited by large numbers of all kinds of 
 people who, in the long sittings, pretty gener- 
 ally thoroughly cleanse their shoes on the 
 carpets, if they do not add to this their sali- 
 vary contributions. The floating particles ac- 
 cumulate in theatres in enormous quantities, 
 
 in such quantities, indeed, that the tell-tale elec- 
 6
 
 82 DUST AND ITS DANGERS. 
 
 trie light beams show a blue or gray cloud on 
 most occasions where they pierce the dust-la- 
 den air. Now, it is a fact that in most theatres 
 at least there is no efficient means made use 
 of to get this accumulating dust out of the 
 auditorium. The coarser dirt is swept up 
 more or less frequently in all of them, and 
 carried off, but the finer dust is usually simply 
 stirred up again in a perfunctory and wholly 
 useless way from the seats to settle back again 
 into the plush or the carpets, to be stirred up 
 anew by the incoming and outgoing audience. 
 The fact is, the upholstering of the chairs of 
 public assembly-rooms ought never to be done 
 with plush or other rough fabric which catches 
 and holds the dust. The floors should not be 
 carpeted, as there are plenty of other whole- 
 some substitutes, and both the ventilation and 
 the daily cleansing ought to be done under 
 some intelligent direction, so that these places 
 need not continue to be, as so many of them 
 now are, veritable death-traps and distributing 
 centres of bacterial disease. While there are, 
 of course, exceptions to the condition of affairs 
 which has here been described, the exceptions
 
 DUST AND ITS DANGERS. 83 
 
 are not by any means always or usually the 
 more fashionable or popular theatres. 
 
 This matter of enforcing reasonable cleanli- 
 ness in theatres and other places of assembly 
 rests, as all other matters of sanitary reform 
 ultimately do, with the people themselves. So 
 long as the patrons of filthy theatres, either 
 fashionable or not, permit themselves to remain 
 the victims of ignorance or carelessness or cu- 
 pidity the managers of theatres will doubtless 
 continue to do just what they have been doing 
 and are doing, no matter what in their prac- 
 tices is shown to be dangerous. 
 
 Whoever has had occasion to visit the court- 
 rooms in the city of New York and similar 
 conditions are widely prevalent in court-rooms 
 as well as legislative halls elsewhere in this 
 land cannot fail to have been impressed with 
 the general filthiness and dustiness and stuffi- 
 ness which is so pronounced. With the evils 
 which vitiated air causes all are more or less 
 familiar, but to these evils even the large intel- 
 ligence of the members of the legal profession 
 usually supinely submits. That poisoned dust 
 should be added to the burden simply because
 
 84 DUST AND ITS DANGERS. 
 
 there is no general protest against the careless- 
 ness or ignorance which is displayed in the 
 so-called cleaning of these places, seems almost 
 incredible when the importance of the matter 
 is once realized. In the same deplorable con- 
 dition are many of the public school-rooms in 
 both large and small towns. Ventilation is 
 slowly becoming recognized as important, but 
 the removal of dust, which in crowded places 
 is very liable to be infectious, is not systemati- 
 cally attended to. 
 
 Public conveyances into which, especially in 
 this country, people are huddled indiscrimi- 
 nately, are very rarely properly cleaned and 
 dusted. Of course, in these it is not the ordi- 
 nary inorganic dust, the fine coal or iron or 
 sand particles which are most to be dreaded, 
 but the materials which come from uncleanly 
 travellers who are the victims of bacterial dis- 
 ease. The dangers will be removed only when 
 the travellers themselves realize that the dis- 
 gusting and very prevalent habit of spitting 
 upon the floor of public conveyances is not 
 only filthy but may be positively dangerous, 
 and the managers of the transportation com-
 
 DUST AND ITS DANGERS. 8$ 
 
 panics see to it that their conveyances are 
 actually frequently cleaned. 
 
 A railway-car which comes in from its hun- 
 dred-mile trip is, when vacated by its occupants, 
 usually an extremely filthy place ; dangerous 
 even, if by chance it has borne an uncleanly 
 passenger afflicted with bacterial disease. And 
 yet, as every observant person who travels 
 much has often seen, these cars may be started 
 out on the return with their full loads of fresh 
 victims, after no other cleaning than a few 
 random broom-sweeps and a few flips of the 
 feather-duster over the window-seats and plush- 
 covered chairs the windows usually tightly 
 closed meanwhile, and the doors, possibly, but 
 by no means always, opened. 
 
 But here again, if the travelling public will 
 not protest against the filthiness of many pub- 
 lic conveyances, and insist upon a more intel- 
 ligent and careful system of cleaning, matters 
 will probably remain as they are. Where com- 
 petition exists between the transporting com- 
 panies, persistent public protest will in the end 
 be heeded. Where competition does not ex- 
 ist, woe to the traveller.
 
 86 DUST AND ITS DANGERS. 
 
 Sleeping-cars and the state-rooms of steam- 
 ships and hotel bedrooms are almost always 
 liable to contain infectious material, if they 
 have been recently used by uncleanly consump- 
 tives or those ignorant of the danger of their 
 expectoration. When the infectious nature of 
 consumption becomes more generally appre- 
 ciated, hotels and transportation companies 
 over long routes will be compelled to provide 
 special accommodations for such persons as 
 are known to be thus afflicted. In the mean- 
 time, more careful attention to the cleaning 
 and dusting (that is actual removal of dust) 
 of such places will do much to mitigate the 
 evil. In public buildings with bare floors the 
 use of properly-wetted sawdust, sprinkled over 
 the floors before sweeping, should be more 
 generally followed than it is.
 
 CHAPTER XI. 
 
 SOME OBJECTIONS, PROTESTS, AND QUERIES 
 ANSWERED. 
 
 MANY usually very reasonable persons, 
 when brought face to face with such 
 disagreeable facts as have been here set forth, 
 are disposed to petulantly exclaim that they 
 and their friends have got along very well thus 
 far with the dust which they have encountered, 
 and that they don't want to be worried with 
 the possibilities of danger which may lurk un- 
 seen about them. The world's people, they 
 say, have managed to live along in large num- 
 bers for a good many centuries without know- 
 ing any thing about the bacteria which may be 
 sporting in this excellent canopy, the air. 
 
 To these rather short-sighted and impatient 
 expostulations it may be answered : The fact 
 still remains that about one out of seven of 
 87
 
 SS DUST AND ITS DANGERS. 
 
 all the people who die are prematurely carried 
 off by tuberculosis, and a large proportion 
 of these through dust-poisoning, which if we 
 choose we can largely prevent. We are apt 
 to forget that, as soon as we know the cause 
 and the means of prevention of a disease like 
 consumption, the responsibility for a large 
 death-rate is no longer to be laid to the charge 
 of Providence or fate, but at the door of human 
 ignorance or carelessness. We are apt to for- 
 get, too, that such dangers from uncleanly air 
 are constantly increasing with the crowding 
 together of large numbers of people in cities, 
 and especially in cities in which the manage- 
 ment of municipal affairs is in the hands, not 
 of intelligent and honest men, but of political 
 tricksters and unjailed thieves. 
 
 We pay the penalty of the close huddling to- 
 gether of large numbers of people in cities, by 
 the increasing vigilance which we must exer- 
 cise to prevent the spread of infectious disease. 
 We may deplore the necessity for such homely 
 and incessant painstaking as is imperative if 
 we would keep our living-places clean and 
 wholesome ; we may carp and cavil at sanitary
 
 DUST AND ITS DANGERS. 89 
 
 preachments if we will, but we ignore them at 
 our peril. Rich or poor, high or low, ignorant 
 or learned, all are alike liable to become the 
 victims of such diseases as are spread in the 
 floating dust of ill-kept towns and dust-ridden 
 houses. 
 
 If the prevention of the spread of consump- 
 tion were a matter which could be carried out 
 by physicians alone there would indeed be 
 little use in inciting a general apprehension of 
 the dangers of dust-poisoning. But, unfortu- 
 nately, this is not possible. If we are, in any 
 large degree, to limit the ravages of consump- 
 tion, and with it the evils of many other bacterial 
 diseases, this must be done through the thor- 
 ough understanding of the danger and its 
 nature by the people at large, and the practice 
 of proper cleanliness in the houses which 
 they directly control, and also by forcing clean- 
 liness upon the managers of public places, 
 which in the end they also ultimately control 
 through public opinion. 
 
 If it be not worth while to save one out of 
 every eight or ten or one hundred or one thou- 
 sand from the distress and pain and misery of
 
 DUST AND ITS DANGERS. 
 
 the consumptive's lot, then such considerations 
 as have been urged in this book are worse than 
 useless. But if, on the other hand, the moder- 
 ate care and attention to cleanliness in the places 
 in which we live or which we frequent is but a 
 small price to pay for the large immunity from 
 disease which would surely follow, then the end 
 in view would seem fully to justify any pains 
 which we may take to make and keep our 
 living-places clean and wholesome. 
 
 Many are disposed to assume that in towns 
 whose affairs are administered by dishonest or 
 careless officials the task of cleanliness in 
 houses is a nearly hopeless one, and this, in a 
 measure, is true. But we are too prone, in 
 this country, to permit ourselves to be imposed 
 upon in countless ways without protest, and 
 with a supineness or indifference wilich is little 
 short of disgraceful. 
 
 There is probably no city or town in the 
 United States which need be either misgov- 
 erned or filthy, if only the respectable people 
 would intelligently unite in the assertion of 
 their rights. In the matter of dust and street 
 dirt, in which regard the city of New York is
 
 DUST AND ITS DANGERS. 91 
 
 in such a desperate case, much more is in- 
 volved than individual right or personal com- 
 fort. We virtually condone manslaughter just 
 as long as we permit men to hold municipal 
 offices who fail in their plain duty in the 
 protection of the public health. From mayor 
 to scavenger they should be held personally 
 responsible, and no political chicanery per- 
 mitted to obscure or call away public attention 
 from the business which such persons are 
 appointed and paid to attend to. We owe a 
 great deal to the vigilance of the press in 
 calling attention to sanitary abuses, but with- 
 out the steady and persistent urgency of 
 individual protest this is of but little avail. 
 
 Until the recent revelations in bacteriology 
 gave us firm ground to stand upon in forming 
 our conceptions of the cause of contagious and 
 infectious diseases, there was something most 
 mysterious and dreadful, and the more uncanny 
 because mysterious, about the agency which 
 could so subtly convey a dreaded disease from 
 one to another. That invisible thing which 
 could linger about a room or cling to a folded
 
 92 DUST AND ITS DANGERS. 
 
 garment for weeks or months which could 
 pass unseen through the air and work desola- 
 tion far away was something which might 
 well inspire awe, if not superstition. 
 
 To-day, however, the whole aspect of affairs 
 has changed. We have at last found out that 
 these subtle agencies in the diseases of this 
 class which have been most fully studied, are 
 well-defined organisms which we can isolate 
 and cultivate and study, small as they are, with 
 as much precision and certainty as we can 
 cabbages and pumpkins. We know a great 
 deal about the conditions which favor their 
 growth, and various things which, at least 
 outside of the body, will kill them and render 
 them harmless. 
 
 With this definite knowledge about some of 
 the agents (bacteria) which cause disease, the 
 most impenetrable of the mysteries clustering 
 about the infectious diseases have passed away. 
 For while we do not yet know, as we have seen 
 in another chapter, the exact form or species 
 which is concerned in causing all of the dis- 
 eases of this class, we have indisputable 
 ground for assuming that they all are caused
 
 DUST AND ITS DANGERS. 93 
 
 by some formed, minute, living thing, either 
 plant or animal. This leads us to the further 
 definite conclusion that whenever one of the 
 contagious or infectious diseases is conveyed 
 from one person to another, this is done by 
 formed material which must pass from one to 
 another, either in the shape of palpable solid 
 matter or by fine floating dust-particles. 
 
 Now, when we interpret this rather long 
 exposition of facts and inferences into every- 
 day experience, we find that it means some- 
 thing like this : When we have in the house 
 a victim of one of the infectious diseases, such 
 as diphtheria or consumption, and want to 
 protect the house-mates against it, both while 
 it is active and after it is over, we no longer 
 grope after some mysterous, intangible thing, 
 before which we must bow down or burn 
 something, as if it were some demon which we 
 would exorcise. We say to ourselves, if we 
 can at once destroy, by boiling it or burning it 
 or soaking it in some suitable disinfectant, all 
 the material which is discharged from the 
 patient's body, he will cease to be a source 
 of contagion the poison cannot spread from
 
 94 DUST AND ITS DANGERS. 
 
 him. When the illness is over and we disin- 
 fect the rooms, we aim not to drive out any 
 malign spirit, any mysterious kobold lingering 
 in the air, but we are trying to kill the bacteria 
 or other similar organisms which may have 
 escaped our vigilance during the disease, and 
 in more or less solid form or as floating dust 
 have found lodgment on bedding, furniture, 
 garments, or on walls or hangings. In all the 
 management of the sick room, in all we do for 
 the person of one suffering from an infectious 
 disease, this is the conception which we should 
 cherish as to the source of danger. 
 
 Most likely many will say, in view of what 
 has been set forth in this little book about the 
 transmission of the germ of consumption by 
 floating dust : " Why do we not all catch con- 
 sumption, if, as he says, it is contagious ? We 
 should be very apt to catch small-pox or 
 scarlatina if brought in contact with them. It 
 can't be true that consumption is contagious." 
 To this it may be answered that some of these 
 diseases are much more readily communicated 
 than others are from person to person. Thus 
 scarlet-fever and measles and small-pox are
 
 DUST AND ITS DANGERS. 95 
 
 much more readily transmitted than is diph- 
 theria or consumption ; they are, as we say, 
 more highly contagious, and although we do 
 not yet exactly know what form of germ causes 
 scarlet-fever and measles and small-pox, we are 
 pretty certain that they are caused by germs 
 or lowly organisms of some kind, and that 
 these are much more readily or freely given 
 off from the body than are the germs which 
 cause less easily communicated diseases, such 
 as consumption and diphtheria, and are more 
 liable to exist in the form of particles which 
 float in the air as impalpable dust. 
 
 Then, again, we should not lose sight of the 
 fact that the germ of consumption is a very 
 slowly-growing germ ; that only under a very 
 limited range of conditions does it grow at all, 
 and that after all the chances are not very 
 great for each one of us that from aerial con- 
 taminations a sufficient number of the living 
 bacilli, even if breathed in and passing all the 
 safeguards of the body against such intruders, 
 at last find lodgment in the tissues, will find the 
 conditions favorable for a sufficient growth to 
 induce the disease, Now and again only does
 
 96 DUST AND ITS DANGERS. 
 
 the favorable combination of conditions occur, 
 but and let this be noted well the nows and 
 agains are frequent enough in the aggregate to 
 secure for consumption the distinction of being 
 the most common and serious, as it is the most 
 distinctly preventable, disease known to man. 
 
 It might be thought that if we know what 
 form of germ causes a given infectious disease, 
 and what chemical substance or drug will kill 
 it, we could readily control the disease when 
 once established in the body by giving a medi- 
 cine which would kill the germs. So we could ; 
 but unfortunately the whole body is made 
 up of little masses of living matter, which 
 we call cells, and these are about as readily 
 killed as bacteria are by the drugs which we 
 should like to use for this purpose. So that in 
 killing the germs we should be apt to stop the 
 disease indeed, but kill the body too. 
 
 We hope sometime, as has been already 
 said, to find some sort of agency which will 
 kill, or render harmless, the germs which cause 
 infectious diseases without harming the body. 
 But in the meanwhile, and perhaps always 
 since the Irishman's conduct in swallowing
 
 DUST AND ITS DANGERS, 97 
 
 a potato-bug and then swallowing Paris green 
 to kill it was not very rational we must do 
 the best we can along the lines which have 
 been suggested in this book to prevent the 
 occurrence of these diseases by destroying the 
 germs before they get scattered in the dust, or, 
 failing in the opportunity for this, see to it 
 that the dust itself is intelligently disposed of. 
 - One of the most serious obstacles in the way 
 of clean living in towns in this country is the 
 especially American expectoratory prerogative, 
 which so frequently both anticipates and ac- 
 companies the franchise in otherwise decent 
 males. The trick is early acquired by our 
 mongrel immigrants, who lose no time in bet- 
 tering our instructions. Could women, walking 
 upon our streets, leaving cars, and descending 
 from elevated railroad stations, but see them- 
 selves and their environment as others see 
 them, the management of the skirts of walk- 
 ing-suits would, it would seem, command from 
 them a more careful attention. We must 
 speak plainly here, for very surely unto dust 
 does all this expectorated unspeakableness 
 
 soon return, 
 
 7
 
 98 DUST AND ITS DANGERS. 
 
 The spectacle of the well-dressed, filthy 
 brutes, whom natural selection has most un- 
 kindly left but a few degrees higher than their 
 congeners in the sty, wallowing in their ex- 
 pectoration, about certain hotels and theatre 
 entrances, may well impress the sensitive on- 
 looker with the colossal task which Nature 
 undertook when she set to work to evolve 
 man, and the lamentable failures which are so 
 often but half-concealed in fashionable attire.
 
 CHAPTER XII. 
 
 SUMMARY AND CONCLUSION. 
 
 IF, now, we sum up the main points which 
 have been urged regarding the ordinary 
 mode of transmission from one to another 
 through the air of the germ of consumption 
 and the means of avoiding it, we see, in the 
 first place, that the most complete remedy of 
 existing evils is simply the immediate destruc- 
 tion of the material discharged from the lungs 
 of affected persons ; second, the practice, both 
 in private houses, in places of assembly, and 
 in public conveyances, of more intelligent and 
 efficient systems of cleaning, and particularly 
 the adoption of appropriate means for getting 
 rid of the floating or settled dust. 
 
 The dust of ordinarily clean public rooms 
 and of private houses is not, as we have seen, 
 dangerous or especially harmful unless it has 
 
 99
 
 100 DUST AND ITS DANGERS. 
 
 among its ingredients the living germs which 
 have come from the bodies of persons suffering 
 from bacterial disease. This dangerous ad- 
 mixture in dust is always possible in populous 
 towns, and while the danger from this source 
 is in general not very imminent, it is increased 
 in direct proportion to the accumulation of dust 
 which is allowed to occur either in private 
 houses or places of assembly. 
 
 Two important means exist for getting rid 
 of dust either in private houses or in places of 
 assembly or public conveyances. The first is 
 to sweep and to stir up the dust with windows 
 and doors wide open, so that the temporarily 
 floating particles may be largely carried out-of- 
 doors, where they will be soon diluted and swept 
 off. It should, in the second place, be borne 
 in mind that in still rooms the dust, and with 
 it the larger part of the aerial germs, will 
 settle, within a few hours, so as to leave the 
 room almost entirely free from them. If, now, 
 the mopping of the floor or the dusting of furni- 
 ture with moist cloths be practised, the larger 
 part of the dust may be completely removed 
 from the rooms. The completeness of this
 
 DUST AND ITS DANGERS. IOI 
 
 removal will, of course, depend largely upon 
 the simplicity of the furnishing and the intelli- 
 gence which is used in the work. The relega- 
 tion of the work of sweeping and dusting of 
 rooms to ignorant and careless servants, with- 
 out intelligent and persistent supervision, can- 
 not be expected to result in clean living-places. 
 We realize more fully now than ever before, 
 weighing the accumulated experience of years 
 in the light of the new knowledge about the 
 cause of consumption, that this disease is by 
 no means always a hopeless or fatal one. 
 Many persons get well, and many more so far 
 recover as to enjoy years of comfortable life. 
 We do not yet know any particular drug or any 
 especial medical treatment which can be depen- 
 ded upon to cure consumption. But we do know 
 that, by putting the body under certain favor- 
 able conditions proper food, suitable climate, 
 appropriate regimen, and aiding these, when 
 occasion requires, by drugs, the physician can 
 often hold out to his patient this well-grounded 
 hope, that the body's natural safeguards against 
 the invasions of bacteria reinforced in this way 
 may lead him to recovery and a new life. But
 
 102 DUST AND ITS DANGERS. 
 
 this lesson, first of all, the patient should learn, 
 that he must see to it that all expectoration be 
 destroyed, or else he is constantly running the 
 risk of reinfecting himself, and thus destroying 
 his chances of a victory over the disease, and 
 is, moreover, exposing others to a serious risk 
 of acquiring it. 
 
 The establishment of special sanitariums in 
 the country where consumptives may be intel- 
 ligently cared for is not only of great benefit 
 to the stricken individuals themselves giving 
 them, as a rule, the best chances for recovery, 
 but is of incalculable importance to commu- 
 nities at large, since it removes an important 
 and, as we have seen, often active source of 
 dissemination of the disease. 
 
 It has not seemed to fall within the scope of 
 this little book to give detailed directions as to 
 the most efficient means of destroying infec- 
 tious material in the sick room nor the modes 
 of disinfection of such rooms when the disease 
 has passed, because these are matters which will 
 always be attended to by the physician if he be 
 intelligent and well informed, and must vary 
 more or less with the conditions of each case.
 
 DUST AND ITS DANGERS. 103 
 
 A little thoughtful consideration of the facts 
 and principles which have been set forth can- 
 not fail to result, under ordinary circumstances, 
 in an improved sanitary condition of the places 
 in which we so largely spend our lives. 
 
 We are just entering upon a new epoch in 
 our knowledge of disease. The discovery of 
 the bacterial origin of so many of the infectious 
 diseases, which have hitherto been as myste- 
 rious as they were fatal, has placed us on a 
 higher plane, so that there is a good hope that 
 in the not distant future we may not only in 
 large degree limit the spread of these diseases, 
 but even learn some reliable means of cure for 
 them. We have in our hands to-day as we 
 have seen the means of prevention in large 
 measure of consumption provided the simplest 
 dictates of cleanliness be followed and the same 
 may be said of typhoid-fever, diphtheria, ery- 
 sipelas, blood-poisoning, and several other in- 
 fectious diseases. 
 
 It is because medical science is raising itself, 
 in the light of our new knowledge, to the higher 
 plane of the general prevention of the infec- 
 tious diseases, that we are hearing so much
 
 104 DUST AND ITS DANGERS. 
 
 nowadays about bacteria and germs and infec- 
 tion and the need of a more intelligent 
 cleanliness. 
 
 It is not a mere fashion at whose dictates 
 the doctrine of cleanliness in person, food, and 
 air is being so widely and earnestly proclaimed 
 to-day. It is no fad of the hour which is to pass 
 and be forgotten. If our research into the 
 sources of widespread human ill does carry us 
 down into the realm of the invisible world we 
 bring from it such knowledge as is full of 
 significance and rich in the promise of human 
 weal, if we do but heed the lessons which are 
 already clear, precise, and not easily to be 
 mistaken.
 
 INDEX. 
 
 PAGE 
 
 Air, amount of, used for biological analysis ..... 23 
 
 " analysis, biological, methods of . . . . . 13, 19 
 
 " " " " filtration method of . . . .15 
 
 " plate method of ..... 15-18 
 
 " bacteria of, as disease producers . . . . . . 52, 53 
 
 " contaminated by tubercle bacilli in dust of . .... 66 
 
 " effects of stirring of, in altering germ contents . . . .31 
 
 " " sweeping on ....... 31-33 
 
 " exhaled, freedom of, from dust and germs ..... 69 
 
 " filtration of, in ventilating shafts ...... 79 
 
 " in-doors, bacteria in . . . . . . .33 
 
 " " dangers of, from floating dust ..... 76 
 
 germs in 27 
 
 origin of germs found in . . . . . . 30 
 
 ki * 4 spontaneous freeing of, from dust and germs . . .37 
 
 kl u varying number of germs in . . . . . . 34 
 
 " modes of spontaneous freeing of, from dust and germs . . .31 
 
 " of theatres and other public places as sources of disease . . .81 
 
 " out-doors, varying number of germs in . . . . 22, 23 
 
 " " spontaneous freeing of, from germs . . . .21 
 
 " probability that consumption is commonly transmitted through . 65 
 
 " street-, in cities, dangers of, from its floating dust . . . 7S 
 
 " li in New York during cleaning . . . . . 25, 26 
 
 Antaeus 16 
 
 Asiatic cholera ......... 55 
 
 Bacilli ... 13 
 
 " -tubercle 48 
 
 " " dangers from, in sputum of consumptives . . .61 
 
 habitat of . . . . . . . .64 
 
 " " in bodies of apparently healthy persons . . .67 
 
 " " " dust of rooms used by consumptives . . .66 
 
 105
 
 106 INDEX. 
 
 Bacilli-tubercle, mode of action of, in producing consumption . . 60 
 
 Bacillus of tuberculosis ........ 59 
 
 Bacteria, colonies of ........ 12 
 
 definite knowledge of, as explaining many mysteries of disease . 92 
 disease-producing .... 53 
 
 forms of 7 
 
 " in air as disease producers ...... 52 
 
 " " in-doors dust ........ 27 
 
 " " out-doors dust ........ 21 
 
 " modt of determining number of, in air . . . . 13 
 
 " modes of disposal of, in the body when inhaled . . .46 
 
 " " " formation of dust from ..... 8 
 
 14 modes of study of . . . . . . .11 
 
 " nature of 7 
 
 " occurrence of, in nature ...... 8 
 
 " relations of, to infectious diseases ..... 55 
 
 " significance of, in air in general ..... 20 
 
 Bacterial-diseases, remedial agents in . . . . .96 
 
 Bacteriology as throwing light on disease . . . . -91 
 
 Berlin, air analyses in ........ 23 
 
 Biological air analysis ........ 19 
 
 Blood-poisoning ......... 55 
 
 Boston, air analysis in ........ 23 
 
 Burning, best mode of destroying germ-laden sputum in consumption . 72 
 
 Carnelly, air analyses by . . . . . . . . 23, 33 
 
 Catarrh, relations of dust to ....... 52 
 
 Cells, ciliated, in air tubes ....... 38 
 
 Central Park, N.Y., analysis of air in . . . . . .25,26 
 
 Cleaning of rooms . . . . . . . . 82, 86, 100 
 
 Cleanliness, importance of, in living places ..... 90 
 
 Cloths, dangers of use of, to receive tubercular sputum . . 71 
 
 College of Physicians and Surgeons, N. Y., air analysis at . . -33.34 
 
 Consumption . . . . . . . . . .56 
 
 " a preventable disease ...... 57 
 
 " heredity of . . . . . . . .59 
 
 " importance of, as compared with other diseases . . 62 
 
 " insidiousness and slow beginning of . . -57 
 
 " mode of transmission most common . . . .64 
 
 " mortality from, in various cities ..... 63 
 
 " most direct means of preventing spread of . 71 
 
 " not always a hopeless disease . . 73, 101
 
 INDEX. 107 
 
 PAGE 
 
 Consumption not one of the highly contagious diseases . . .94 
 
 " of the lungs the most common form of tuberculosis . . 65 
 
 predisposition of certain persons to . . . 59 
 
 prevalence and mortality of ..... 57, 61 
 
 " proper food and surroundings more important than drugs in 
 
 the treatment of ...... 101 
 
 " spre id by meat and milk ...... 64 
 
 " summary of the reasons of prevalence of ... 70 
 
 " transmission of,' in unclean sleeping-cars, bedrooms, and 
 
 steamships ....... 86 
 
 " transmission of, to attendants upon the sick . . .68 
 
 " tubercle bacilli the only direct cause of . . . .59 
 
 " ways in which il is spread by dust . . . .58 
 
 Contagion .......... 93 
 
 Contagiousness, degrees of, in bacterial diseases . . . 94 
 
 Cornet, discovery of tubercle bacilli in consumptives' rooms . . .66 
 
 Cotton filters for bacterial air analysis ...... 14 
 
 Court-rooms, filthy and dangerous air of . . . . -83 
 
 Crime, toleration of filthy cities by the people a . . . -91 
 
 Culture medium for germs ....... 14 
 
 " methods for germs ....... n 
 
 Destruction of discharged material best means for preventing spread of 
 
 bacterial diseases ...... 99 
 
 Diphtheria .......... 55 
 
 Disease, preventable ........ 54 
 
 " relation of dust to . . . . . . . .50 
 
 Diseases, infectious ......... 55 
 
 " " presence of bacteria in explaining many mysteries of . 91 
 
 " " relation of bacteria to ..... 55 
 
 " of occupation . ....... 5 
 
 Disinfection, modern notions of, more precise ..... 93 
 
 Drugs in infectious diseases ....... 96 
 
 Dundee, air analysis in . . . . . . .23 
 
 Dust, as means of spreading consumption or tuberculosis . . .58 
 
 " " source of danger in public assembly rooms . . . .81 
 
 " coal- and cotton- ...... 4 
 
 " dangers of, in public buildings ...... 80 
 
 " -dangers out-doors and in-doors . . . . 74 
 
 " definition of . . . a 
 
 " filtration of, out of lymph in the lungs . . . 45 
 
 " in-doors, germs in . . . . 2 7
 
 108 INDEX. 
 
 PAGE 
 
 Dust, harmful effects of, on the eyes ...... 52 
 
 " in inhaled air, disposal of, by body ..... 37 
 
 " " public conveyances . ...... 84 
 
 " " theatres, or as means of conveyance of disease . . .81 
 
 " " railway carriages as source of danger ..... 85 
 
 " in-doors, danger of infection from ...... 76 
 
 " inorganic elements of ....... 4 
 
 " " " " as causes of disease . . . .51 
 
 " lodgment of, in tissues of lungs . . . . ... 44 
 
 " materials composing ........ 3 
 
 " metallic ......... 4 
 
 " mode of occurrence of bacteria in .... 8 
 
 " out-of-doors, micro-organisms in . . . . . .20 
 
 " relations of, to catarrh . . . . . . . -52 
 
 " removal of, from houses ....... 77 
 
 " safeguards of body against ....... 36 
 
 " settling of, in-doors ........ 22 
 
 " significance of, in causing disease ...... 50 
 
 " sweeping away of, by ciliated cells ..... 39 
 
 " street-, dangers of infection from ..... 75 
 
 " tenacious clinging of, to fabrics ...... 29 
 
 " tobacco- ......... 5 
 
 " tubercle bacilli in . . . . . . .66 
 
 " two modes of freeing air from ...... too 
 
 " woollen . .... ... .5 
 
 Dusting .......... 78 
 
 Elevated R. R. in New York as source of annoyance and danger from dust 52 
 Erysipelas .......... 55 
 
 Evolution, failure of, to eliminate the porcine element in street loafers . 98 
 Expectoration as a common vice . . . . . 97 
 
 " dangers of, in consumptives . . . . .61 
 
 Eyes, harmful effects of dust on . . . . . . .52 
 
 Filters, air-, in biological air analysis ...... 13-15 
 
 " dust-, lymph-glands in lungs as . . . . . .46 
 
 Filthy cities, no necessity for . . . . . .90 
 
 Filtration method of air analysis ....... 15 
 
 General knowledge, necessary to prevent spread of bacterial diseases by dust 89 
 Germs, aerial modes of study of. . . . . . . 11-13
 
 INDEX. 
 
 PAGE 
 
 Germs in in-doors dust . . . . . . . .27 
 
 11 in out-doors dust ........20 
 
 " colonies of . . . . . . . . .12 
 
 " nature of ......... 7 
 
 " origin of, in in-doors air . . . . . . .30 
 
 " safeguards of body against aerial ..... 36 
 
 Hotel bedrooms as sources of dust-infection ..... 89 
 House furnishing as affecting the risk of dust-infection . . .78 
 
 Immunity of body to disease germs . ..... 49 
 
 In-doors air, analysis of ........ 27-35 
 
 Infection, dangers of, from street dust ...... 75 
 
 " degrees of readiness of, in different diseases . . .94 
 
 Infectious diseases ......... 55 
 
 " remedial agents in . . . . .96 
 
 Isolation of the sick as means of prevention of bacterial diseases . . 54 
 
 Lungs, most common seat of tuberculosis .... 65 
 
 " pigmentation of, by inhaled dust ..... 44 
 
 Lymph, filtration of, in the lungs ...... 45 
 
 Lymph-glands as dust-filters . . . . . . .46 
 
 " " localized tuberculosis in . . . . . .67 
 
 Measles 53,94 
 
 Meat, tubercular, as food, dangers of . . . . .64 
 
 Michigan, frequency of consumption as compared with small-pox in . 62 
 
 Micro-organisms in in-doors dust ....... 27 
 
 " " " out-doors dust ...... 20 
 
 " " nature of . . ...... 7 
 
 kt '* safeguards of body against . .... 36 
 
 Milk from diseased cows, dangers of 64 
 
 Motes in the sunbeam ........ 3 
 
 Moulds 7 
 
 Mould-spores in air analysis ....... 18 
 
 " " " dust ........ 9 
 
 " " preponderance of, in wet weather . . . .22 
 
 Neumann, air analysis by . . . . . . . .33 
 
 New York, air analysis in . ....... 33-26 
 
 " " filthy streets of ....... 21 
 
 Official negligence no excuse for private indifference to cleanliness . . 90
 
 1 10 INDEX. 
 
 PAGE 
 
 Petri's air analysis ......... 23 
 
 Phagocysts . . . . . . . . . 40-42,48 
 
 Phlegm, removal of, by ciliated cells . . . . . .40 
 
 Plate method of air analysis ....... 15-18 
 
 Pneumonia 55 
 
 Predisposition to consumption ....... 59 
 
 Preventable diseases . . . . . . . .54 
 
 Prevention of disease, a public and private duty . . . .88 
 
 " " " more reasonable than neglect and attempts to cure . 96 
 Public conveyances as sources of danger from infectious dust . . .84 
 
 Railway carriages as sources of danger from dust . . . .85 
 
 Rain, effects of, on number of aerial germs ..... 22 
 Reinfection of tubercular persons by expectoration .... 102 
 Rooms as repositories of dust and germs ...... 29 
 
 Safeguards of body against dust and germs . . . . . 36, 75 
 
 Sand filters for biological analysis ...... 15 
 
 Sanitariums for consumptives . . . . . . 102 
 
 Scarlatina . . . . . . . . . . 55, 94 
 
 Scavenger cells ......... 41 
 
 School-rooms, dust in.. ......84 
 
 Sleeping-cars as sources of infection ...... 86 
 
 Small-pox . . . . . . . . . 55, 62, 94 
 
 Snow, effects of, on aerial germs ....... 22 
 
 Spitting-cups for consumptives ....... 71 
 
 Spitting, dangerous and filthy nature of . . . . . . 72, 97 
 
 Sputum, dangerous nature of, in consumption . . . . . 60, 66 
 
 " proper means of disposing of, in comsumption . . .71 
 
 Steamships, state-rooms of , as sources of danger . . . .86 
 
 Stein, experiments of, on floating dust ...... 28 
 
 Sugar-felters in air analysis ....... 15 
 
 Sweeping, effects of, on aerial germs in rooms . . . . 3i~33 
 
 Theatres, dusty, dangers of ....... 81 
 
 " responsibility of the public for filthiness of . . . .83 
 
 " vicious methods of cleaning of ..... 82 
 
 Tubercle bacilli ......... 48 
 
 " " growth of, in the body only under favorable conditions . 95 
 
 " " habitat of ....... 64 
 
 u '* how spread in the air . . . . . .64 
 
 " "in dusty rooms occupied by consumptives . . .66
 
 INDEX. 1 1 1 
 
 
 PAGE 
 
 Tubercle bacilli in expectoration in tuberculosis of lungs . . 
 
 60 
 
 " " " the bodies of apparently healthy persons . . 
 
 67 
 
 " " mode of action in causing consumption . . 
 
 60 
 
 " " not easily killed by drying . . , . 
 
 6 5 
 
 " " spread of, by diseased meat and bad milk . 
 
 . 6 4 
 
 " " the sole direct cause of consumption . . 
 
 59 
 
 " " vulnerability of, when growing with other germs . 
 
 . 64 
 
 Tuberculosis . . . . . . . . . 
 
 55i 56 
 
 " bacilli of, mode of action in causing 
 
 60 
 
 " frequency and mortality of .... 
 
 . 61, 62 
 
 " heredity of . 
 
 59 
 
 " in other parts of th body than the lungs . . 
 
 60 
 
 . " localized 
 
 67 
 
 " mode of transmission of . . . . 
 
 . 64 
 
 " predisposition to ...... 
 
 59 
 
 " spread of, by meat and milk .... 
 
 64 
 
 " " " dust 
 
 58 
 
 Tucker, air analysis by ....... 
 
 2 3> 3 1 
 
 Typhoid fever . . . . . 
 
 55 
 
 Ventilation, effects of, on floating dust ..... 
 
 28 
 
 Vigilance necessary to prevent spread of bacterial diseases- . . 
 
 88 
 
 Wind, effects of, on floating dust and germs .... 
 
 . 22 
 
 Yellow fever 
 
 55 
 
 THE END.
 
 STATE NORMAL SCHOOL 
 
 w * 
 
 3 5 '\
 
 
 UNIVERSITY OF CALIFORNIA LIBRARY 
 
 Los Angeles 
 This book is DUE on the last date stamped below. 
 
 /,> - 
 
 MAR 141981
 
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