[From Causes of Consumption, 1899]

THE CAUSES OF CONSUMPTION.

CHAPTER I

CLIMATE—SOIL—MAL-NUTRITION—OCCUPATION.

CLIMATE.—The lungs come into such direct contact with the atmosphere that surrounds us, that we naturally look for an atmospheric origin in most pulmonary troubles. It is very easy to see, therefore, why men in all times have sought to establish a climatic origin for phthisis; and it was almost universally held by the ancients that a damp and changeable climate was most favourable for its development. It is chiefly owing to this fact, and to its supposed excessive prevalence in the British Isles, that it was often spoken of as 'la maladie Anglaise !' On making a careful examination of the statistics now at our disposal, however we are soon convinced that the ancient doctrine is erroneous.

When we come to study the distribution of phthisis, we are at once struck with its widespread prevalence.

For the information concerning the distribution of this disease we are chiefly indebted to Hirsch and Lombard, and the latter, in his 'Climatologie Medicale,' furnishes us with a most interesting map of the world, which is shaded in such a manner as to show at a glance the prevalence or otherwise of phthisis in any given locality. So persistently does the shade darken as the density of population increases, that, with one or two exceptions, the map might equally well do duty for either phthisis mortality, or density of population. A glance at this chart convinces us that we must look elsewhere for the main causes at least of this dread disease, and that the part played by climate is comparatively small.

And if we study the exceptions to the rule, that density of population and phthisis go hand in hand, we are only strengthened the more in this conviction.

Among these exceptions are Nubia and Upper Egypt, Abyssinia and Central Africa; Livingstone also states that consumption is quite unknown in South Africa and the interior of Cape Colony. Yet we find that it is very prevalent in Lower Egypt, Tropical America, India, and China-countries that, though in some cases separated by long distances, are subject to very similar climatic conditions to the exceptions just quoted.

Again, those countries that border the Arctic Circle, such as Siberia, British North America, Iceland, and Spitzbergen, enjoy a remarkable immunity from this disease ; still, we are told by Arctic voyagers that the Eskimo by no means escape it, and that it is one of the commonest causes of death in Greenland and Russian America.

On the whole however, the general concensus of opinion seems to be, that the keen, dry, cold air of the sub-arctic regions is particularly favourable to those predisposed to, or actually suffering from, phthisis. Various theories have been propounded to account for this immunity, some attaching special value to the fish diet, especially the abundant use of the codfish; others claiming virtue for Iceland moss; but the more reasonable explanation seems to be that the peculiar atmospheric conditions are unsuited to the existence of the tubercle bacillus. Certainly the dwellings and the domestic conditions of these Northerners are not of such a nature as to minimise the risks of consumption, for Thomsen ¹ says of them

"They eat their food generally cold, often putrid, and always at irregular times. They have no artificial means of warmth, and, therefore, allow no ventilation in their miserable hovels, which are built of damp earth, and where the whole family remains huddled up, not only at night, but the greater part of the day also, during six months of the year, with their cattle, sheep, dogs, and all the live stock they may happen to possess. Indeed, the air in these dwellings becomes so poisonous from the breath of the inmates, their refuse, and the fuel they use (composed of dung, rotten bones, and anything that can be got to burn), that it becomes extremely dangerous to women after parturition and to new-born infants. Nevertheless, the population, though subject to great fluctuations in consequence of the great liability to epidemic diseases, is steadily increasing."

There is another class of people who enjoy a similar immunity-namely, those who dwell in such mountainous districts as the Alps, Appenines, Ural Mountains, and Himalayas. Gastaldi, who was the first to point out this fact, puts the degree of elevation at a,ooo feet, below which phthisis was as common as elsewhere. But this immunity is not entirely due to the rarity of the air, but also to the free open-air life of the mountaineers, for, when by any chance their occupations bring them to the same indoor restrained condition as the lowlanders, the immunity ceases. Dr. Emil Miller, in his treatise on the distribution of consumption in Switzerland, says that a certain proportion of the inhabitants dwelling high up the mountains die of this disease, the rate depending more upon the nature of their occupation than upon the elevation of their dwellings above sea level. Indoor pursuits give a rate varying from 6·5 to 10·2 per cent., and one of the highest of these rates is at an elevation of 4,000 feet. Again, it has been remarked that among certain tribes where consumption was, a few years ago, practically unknown, it is now one of the commonest causes of death, owing, in a large, degree, to such a radical change of habit as that from a life under canvas or wigwam, to dwelling in stone houses. This led Hirsch ² to remark, " an altered mode of life amongst whole populations has had a most decided influence upon the rise and progress of consumpti')n, whilst the climate in which they live remains the same as it was before."

With regard to the influence of cold on the prevalence of consumption, Dr. Ransome ³ says: " But it is not yet clear in what way a cold climate exerts this favourable influence; we may indeed surmise that the lower amount of humidity in the atmosphere of these regions may have something to do with the results. Cold air has a much smaller capacity for aqueous vapour than warm air. It may thus be less capable of sustaining the life of the microscopic organisms that are the exciting cause of consumption; or again, it is possible that there are smaller quantities of organically charged vapours arising from the ground, frozen as it is for so large a portion of the year. Moreover, in a frosty air the condensed moisture may entangle the organisms in its meshes, and may carry them down out of harm's way." ⁴

It is rather difficult to say what influence strong winds have upon this disease. Dr. Haviland ⁵ maintains that strong winds, no matter from what quarter they blow, are powerful factors in the production of phthisis, and he proves this by saying that wherever we get a district that is unprotected from high winds, we get a high consumption mortality-such is the case for example in the low-lying eastern counties, which are fully exposed to the east wind. On the other hand, when we get a district that has a rampart, either of mountains or precipitous cliffs, surrounding it, we have the force of the wind broken, and the consequence is a low phthisis mortality. Such districts are the North Riding of Yorkshire, and the south-west of Devonshire.

And yet we find, by experience, that those exposed to the inclemency of the weather, such as soldiers on campaign, sailors, fishermen, hunters, gipsies, and engine-drivers, are seldom troubled with pulmonary complaints of any kind whatever. Dr. Haviland, in a lecture delivered in Douglas some years ago, says that " persons having any hereditary taint of consumption in the lungs cannot stand the full force of the winds, from whatever direction they blow." But the mere mention in this connection of ' hereditary taint' suggests to one that high winds aggravate the disease when existent, rather than cause it de novo. Whatever influence, therefore, climate may have upon the consumptive, it certainly plays a small part in the production of the disease.

SOIL.-There is no doubt but that the nature of the soil has an influence on the pre- valence or otherwise of consumption. A damp atmosphere may be due to prevailing winds, or to the presence of an impermeable sub-soil which causes the accumulation of moisture on the surface. There is no evidence to show that the dampness due to the former cause has any material effect on the prevalence of the disease ; but more than one investigator has given us ample proof that an atmosphere danip from the latter cause is decidedly favourable to the production of consumption. Dr. Buchanan was appointed by the Privy Council to report on the effect upon public health of sanitary reforms in certains towns. He found that where damp districts had been drained, there was a marked diminution of the phthisis mortality. In fifteen large towns recently drained, he found the phthisis death-rate had fallen, some 10 per cent., some 20 per cent., and some even 49 per cent.

This naturally led Dr. Buchanan to institute further inquiries upon the influence of soil on consumption. After a careful comparison of the geological formation of the regis- tration districts of Surrey, Kent, and Sussex, he was convinced that wetness of soil is a cause of phthisis to the population living on it. The Registrar-General for Scotland fully confirmed this opinion; and Dr. Haviland says : " Damp, clayey soil, whether belonging to the wealden, oolitic, or cretaceous formation, is coincident with a high. (phthisis) mortality. "

Dr. Ransome, in an address to the Sanitary Congress held at Leicester, in 1885, contrasted two populations, one living on a clayey soil, and the other on a sandy one. The results run over a 10 years' mortality table, and there had originated, 22 cases per 1000 ,inhabitants on the clayey lands, and only 1 per 1,000 on the sandy. He moreover remarks that though there might be, hereditary, predisposition among some of the inhabitants on the sandy soil, they did not contract the disease so long as they lived in that locality,

Dr. Bowditch of Boston, U.S.A., drew attention to the close relationship that existed between dampness of soil and prevalence of consumption in Massachusetts. He cited the,testimony of medical men resident in 183 townships in support of this. He also asserted that certain houses on a particular soil might become the foci of consumption, while other houses not far removed, but on a drier soil, might be entirely free. Dr. Williams, in his book on, consumption, gives the following case which came under his own observation :-

" The rector of a parish in Essex resided on a clay soil, and had a large pond immediately in the neighbourhood of his rectory. . He and his wife have always enjoyed good health, and there was no hereditary disease traceable either in his own family or his wife's. Of their twelve children, eight were born in the rectory, four in a neighbouring parish, but all spent their: childhood and. youth at their father's home. Six have died ; four of consumption, one of scrofulous disease of the spine, and one of whooping-cough at-the age of five. Of the six alive, three are healthy; one is delicate, but I have not heard from what cause ; two have scrofulous disease of the spine. The three healthy - ones have been-but-little at home since they have grown up, and one spends much time in travelling-; so that out of twelve children there are no less than four cases of consumption-and three of scrofula:" -

It is necessary, however, to mention, that the above opinions are not confirmed by all observers. Dr. Kelly, M.O.H: for East Essex, has shown that, in 1861-70, the mortality of the several districts named by Dr. Buchanan, had changed from that of 1851-60 without any difference of drainage. Reek asserts that in Brunswick, the consumption mortality was just as great in the dry part of the town as in the wet:. In Dantzic we are told, where a system of main drainage was fully carried out in 1871, the phthisis death rate, which had been 2.12 per 1,000 in the eight previous years, rose during the nine subsequent years to 2.48 per 1,000, and Hirsch states that in Berlin the drainage had no effect on the consumption rate.

One is led, therefore, to believe that, though dampness of soil does not necessarily cause phthisis, it is a very important factor in pre-disposing to that disease.

MAL-NUTRITION.-It has generally been found that the consumption mortality has been greatest among the poor and destitute, and this has favoured the theory that mal-nutrition has been a cause of the disease. We must remember, however, that there are many conditions among this class that ought to be considered in this connection. They are usually herded together in insanitary dwellings, with insufficient ventilation, and insufficient sunshine, as well as insufficient food. The drainage system is by no means above reproach. Very often, more than one family occupies the one house,, and the sleeping apartments are usually overcrowded. Poverty and vice, with their usual attendant, drink, invariably lower the mental tone, and tend to produce' that state of mind, which, for want of a better term, we will call hypochondriasis. We thus have to face, along with mal-nutrition, such questions as re-breathed air, contagion, and lowered vitality from carious causes, and the question becomes a very complex one. In fact, when we come to consider the poorer classes, we meet with a series of factors, any one of which may be equally fruitful in the production of this dread disease. To prove effectually that mal-nutrition is a cause, will, therefore, be no easy matter, until we can eliminate its usual accompaniments, and although we have no doubt but that it may be a predisposing cause, we are sure that it is a very insignificant one

OCCUPATION.-It is when we carry our investigations into the life conditions of a people that we get the data most helpful to a thorough understanding of this important question. We now find that people living under the same conditions as regards climate, atmosphere, subsoil, site, and social scale, are not all equally prone to fall victims to consumption, but are subject to its ravages to a greater or less degree according to the character of their daily occupation, and the intimate surroundings under which that occupation is pursued. On taking a cursory review of the whole question, one is at once impressed with the fact that the causes of consumption seldom go single-handed, but that, given one cause, the chances are that a number of causes more or less dependent on, and inseparable from the first cause, will be found to exist, the result being, that many who might hope to evade one or even two causes, by this multiplicity of actors are utterly unable to escape. Take: for instance, density of population, which whether a cause per se or not, is invariably associated with a high phthisis mortality. It is here we find our great industries carried on, the herding together of the masses in insanitary houses, breathing a vitiated atmosphere, living often in poverty and vice, and especially subject to contagion and infection. It is, therefore, in our great manufacturing centres that we must look for the highest phthisis mortality.

In Dr. Haviland's map we find the darkest spots in the immediate neighbourhood of the industrial centres in Lancashire and Yorkshire, and according to Hirsch's tables we find the highest mortality fiom phthisis in Brunn in Moravia, and Remscheid in Austria, both manufacturing centres, the former of woollen goods, the latter of iron and steel. Other writers on this subject, such as Greenhow, Arlidge, Finkelnburg, Schweig, Boudin, and Chatin, all bear similar testimony as regards the injurious influence of certain occupations. In this connection perhaps the most important factor is the inhalation of dust of various kinds arising from the material manipulated. Since it is now universally accepted that phthisis is a disease due entirely to the deposit of the tubercle bacillus in the lungs, it is difficult to believe that the inhalation of minute particles of either mineral, vegetable, or animal matter, can alone cause this disease. We can, however, easily believe that the chronic irritation of the lungs, caused by the deposit of these dusts in their delicate tissues, may very materially affect their susceptibility to the disease. This inhalation of dust, however, does cause, directly, pronounced pulmonary diseases, some of which are with difficulty distinguished from true phthisis. Such mechanical irritation may cause symptoms of a distinctly asthmatic nature, progressing to emphysema, hardening and contraction of lung tissue, and even breaking down of the same.

This condition may very easily be mistaken for tuberculosis, unless the sputum be examined carefully. Dr. Ransome ⁶ says : " I am quite sure that there are many cases of true cirrhosis or fibroid disease of the lung, sometimes produced by irritating dusts, at others by pleuritic attacks often repeated, and ending in thickening and contraction of the interlobular septa, and, so to speak, in a strangling of certain portions of the lung. I have watched such cases for years, and have satisfied myself by repeated stainings that there were no bacilli in the sputum-and after death no signs of tubercle in the lungs."

It thus becomes very difficult to get thoroughly reliable statistics. But since consumption is very easily engrafted upon these pulmonary troubles, we may hope, by a perusal of the figures at our disposal, to get at a result that will not be far from the truth. The inhalation of dust has been held to be injurious for many years, Wepfer, so far back as 1727, calling attention to the prevalence of phthisis among millstone-grinders. Hirt furnishes us with some elaborate tables on this subject, and I take the liberty of culling a few of the most interesting figures. It will be seen by perusing the table below, that all dusts are not equally harmful in the production of phthisis to the workmen inhaling them. ⁷

TABLE I.-Percentage of Phthisis in total numbers of Sick amongst Workmen exposed to the Inhalation of Dusts of various kinds.

The greatest harm seems to arise from the hardest and most pointed dusts, such as flint and steel; and after these the fine cuttings from bristles, and the dust from glass and porcelain, whereas the softer dusts do comparatively little harm. Ransome found that the cotton-operatives were very little more liable to consumption than ordinary labourers, the percentage of deaths from affections of the lungs being 61 for the former, and 60 for the latter.

Greenhow ⁷ in his report to the Privy Council, states that the cramped posture assumed by the workers in certain industries interferes with free respiratory action, and thus conduces to phthisis, and instances the heavy mortality among the Nottingham lace workers, the watch-makers of Coventry, and the hand-loom weavers of Macclesfield and Leek. Below is the phthisis-ratio of these artisans as compared with the standard :

TABLE II.-Death-rate per 1,000 living from Pulmonary Affections.

We thus see that, in addition to the dust inhaled, we have to consider the posture assumed during work. It is well-known that when the lungs are not fully expanded, the apices remain practically collapsed, and thus form a suitable nidus for the reception and development of the tubercle bacillus. Consequently it will be easily understood that a stooping posture, if long continued, must inevitably predispose to this event.

Other factors there are associated with occupation, for many industries are carried on in unhealthy workshops, where ventilation is deficient, and the workers are subject to sudden and extreme changes of temperature. This latter condition must of necessity tend to pi oduce catarrhal affections which indirectly pave the way for the advent of phthisis.

Occupation, therefore, is often a very powerful factor in producing a high phthisis ratio.

Footnotes

1 Ueber Krankheiten, etc.. auf Island and den Färöer.-Inseln.

2 Geographical and Historical Pathology, vol. ii., p. 89.

3 Milroy Lectures, 1890 : The Causes and Prevention of Phthisis.

4 Koch stated that the tubercle-bacillus requires a temperature above 86° Fahr. for propagation.- C.A.D.

5 Geographical Distribution of Disease.

6 The Causes and Prevention of Phthisis.

7 Fourth Report to the Privy Council.

Any comments, errors or omissions gratefully received The Editor HTML Transcription © F.Coakley , 2006