lymphatics of the interlobular septa, so that a gradual transition from the healthy gland substance to the dense tubercular mass may be seen. In the mass itself the characteristic bacilli are present in almost inconceivable numbers. They are seen first as small stained rings (masses of bacilli) around a slightly granular or homogeneous mass-in fact, the giant cells seem to consist of the débris of cells, the result of the activity of the bacilli. In the smaller cells bacilli may also be seen, and others may be demonstrated lying in the spaces between the cells. On careful examination of the more healthy parts of the gland, especially at the margin of the new growth, ulceration into the ducts may be made out. In consequence of the interference with the nutrition of the tissues immediately around the ducts or acini, the basement membrane has given way and a small mass of tubercular granulation may be seen projecting into the lumen; the epithelium is also proliferating. In the granulation tissue, in the epithelial cells, and even lying free in the lumen, there are frequently numerous bacilli, and it can be easily understood how, once in this position, they find their way into the milk. This ulceration is not, however, of such frequent occurrence as might be expected, for in the greater part of the gland substance left there is little or no catarrhal proliferation, and the ducts and acini appear to be obliterated in great measure by compression. In addition to these positions, bacilli could be demonstrated in epithelial cells still attached, and also in rare cases in those lying free in the apparently healthy milk ducts, in which position Professor MacFadyean had first demonstrated them. These facts, when considered along with the occurrence of bacilli in milk, with the feeding experiments recorded by so many observers, and the great prevalence of tubercle in certain classes of animals, go far to prove that milk is a source of tubercular infection, especially to young children. Cases are constantly cropping up in which pigs on dairy farms are affected with tuberculosis of a most typical character. Dr. Woodhead has recorded an outbreak (amongst pigs) on a dairy farm which could be distinctly traced to the milk of three cows in which the udders were markedly affected. All veterinary authorities concur in stating that cattle and swine are the two species in which genuine tuberculosis most frequently occurs. When it is remembered that on dairy farms, and even on farms where pedigree cattle (cattle which are very frequently highly tubercular) are reared, the milk, especially that of cows suspected of disease, is given to the pigs, which often become tuberculous, it will appear in the light of recent researches that the disease is propter hoc rather than, as so many still hold, merely post hoc. It has often been objected, of course, that if all tuberculous cattle gave tubercular milk, the human race would run a risk of being rapidly exterminated; but it might now be maintained, as the result of most careful clinical observation, that it is only when the functions of the intestine are interfered with, and when, in consequence, there are temporary or permanent alterations in structure and in the chemical constituents of the fluids and gas in the alimentary canal, that tubercle bacilli can make their way unaltered through the epithelial barrier. The importance of Koch's experiments on anthrax and cholera bacilli, when ingested, cannot be over-estimated, and most of those who have followed him in this line of experimentation have come to the same conclusions on this point, however widely they may differ on others. It is not only the intestine itself, however, that is affected by these functional disorders. The mesenteric glands are also placed at a great disadvantage. This may be easily understood when it is remembered how the slightest irritation in any position is almost immediately followed by changes in the lymphatic channels and glands. Every one is familiar with the peculiar condition of enlargement, congestion, and succulence that is found in such glands. This condition must be looked upon as the result of stimulation; the cells are roused into greater activity, they proliferate more rapidly, and take up the foreign matter; the gland as a whole acting as a kind of vital sieve. In this process, however, the store of resistant energy is gradually diminished, and should tubercle bacilli find their way into the gland during or shortly after this extra stimulation, they run less risk of being destroyed by active epithelioid and lymph cells than when these cells are not already partially exhausted. (357) Propagation of Tuberculosis from consuming the Flesh of Tuberculous Animals. In the first place it is still disputed whether bovine tuberculosis is identical with human tuberculosis; if not the same, the probability of contracting the disease would be much less than if the two diseases are identical. The balance of evidence is decidedly on the side of those who agree with Dr. Woodhead, viz., that the tubercle bacilli are identical although they may present some feeble difference of form from being cultivated in the tissues of animals, the temperature of which exceeds that of the human body, for instance the temperature of the pig and cow is from 38°3 to 38°8; in the calf, 39°3; in the horse, 38°3; and in the hen, 40°0 to 40°5, and it may well be that a slight rise of temperature in these animals varies considerably the powers of propagation, and also indirectly the virulence of the bacilli, as indeed Klein's experiments have shown. M. Nocard read at the Congress on Tuberculosis a paper on the dangers to which one is exposed by the use of the flesh of tuberculous animals. It would appear to result, from his very ingenious experiments, that the muscles destroy or digest, as expressed by M. Nocard, the bacilli in such a way that the meat of animals affected with generalised tuberculosis presents but very little danger. Thus, four cats ate with impunity the flesh of a tuberculous cow, whilst a fifth cat that had eaten a lymphatic gland of the cow succumbed in a very short time to experimental tuberculosis. M. Nocard, therefore, thinks that it is not necessary to exaggerate the precautions, or to hold Koch's bacillus in great dread, adding that one can eat without fear the flesh of tuberculous animals, the tubercles of which are limited to the viscera and to the different lymphatics; even that of animals, the tuberculosis of which is generalised would be but exceptionally to be dreaded. W. Kastner also has made a research as to whether the muscles of an animal affected with tubercle of the lung may be eaten with impunity. He made infusions of meat from animals thus affected and injected the infusions into the peritoneal cavities of guinea-pigs. Out of 16 animals thus treated 12 remained healthy. Kastner concludes that special dangers from infection are not to be feared save in the rare cases in which tubercles are to be found in the muscles. On the other hand Professor Jeannel, of Toulouse, has studied the generalisation of tuberculosis by the inoculation of rabbits. Extirpation on the fourth day of the glands above the point inoculated did not prevent the success of the inoculation, which is a proof that the bacilli had not been arrested in the lymphatic system. Moreover the blood of a rabbit inoculated by subcutaneous grafting behaves like a virulent dilution from the second day, perhaps earlier. Injected en masse in the peritoneum, this blood determines an experimental tuberculosis. Hence M. Jeannel does not believe in local tuberculosis; for him the malady is generalised in all the organism before manifesting its existence by visceral localisation. The question as to whether tubercle is ever localised in animals, whether it is confined to the lung, brain, kidney, or liver is one which bears directly upon the practice of a medical officer of health. If in the opinion of those best able to judge; an animal with a small portion of lung alone showing signs of disease, the rest of the viscera being healthy, and the flesh even when submitted to a strict microscopical examination showing no bacilli-yet contains invisible spores which when placed under suitable conditions may develope into tubercle; then it is the duty of the health officer to condemn the whole animal for the least speck of undoubted tuberculous taint. This is the view taken by the Congress on Tuberculosis which met at Paris in 1889, and this is the view taken by Dr. Russell, of Glasgow, as shown by the leading case of prosecution relative to diseased meat in that city fully reported in Public Health, Vol. II., p, 75, and also published as an official sort of blue book by the Glasgow Sanitary Authority. The question cannot be said to be entirely set at rest but the evidence certainly goes so far as to show that this drastic course is the safest, and that such meat does in fact generally contain a few of the bacilli or their spores, and that such meat when eaten in a half-cooked state by young children who inherit some weakness of tissue resistance or are at the time in a state of imperfect health may, and does, produce a certain amount of tubercular infection. (358) Disinfection of Tuberculous Products. It is in the first place important to know in what excreta the tubercle bacilli are likely to be found. In the sputum of the phthisical, it is a matter of common knowledge and utilised daily in clinical work that myriads of the 1 specific micro-organisms are to be found. With regard to the urine the following researches may be mentioned: Lichtheim 1 found in the contents of the renal pelvis of a corpse, tubercle bacilli; Rosenstein 2 also succeeded, in the urine of a person suffering from tuberculosis, in recognising the tubercle bacilli, and thus confirming the diagnosis of tuberculosis of the urogenital apparatus; Babes 3 claimed priority, since he had a few days earlier communicated a similar discovery to the Anatomical Society of Paris. A number of researches followed, recording successful attempts in finding tubercle bacilli in the urine of patients suffering from tuberculosis of the genito-urinary tract. Such observations were by Smith, Irsai, and Probstiug 6; Philipowiez,' who not only in chronic tuberculosis of the kidney, but also in acute miliary tuberculosis, found in the urine of the corpse tubercle bacilli ; farther, by Kerstein, who found tubercle bacilli easily by allowing the urine to subside in a conical glass, and filtering off the sediment; lastly, by Morpurgo and Krecke. The solid excreta from the tuberculous have seldom been investigated. Cramer 11 was the first who recognised in them tubercle bacilli; he also avers that he has several times found bacilli in stools of the healthy, which were not to be distinguished from tubercle bacilli. Lichtheim 12 and de Giacomo 13 found tubercle bacilli in the loose evacuations of patients suffering from tuberculosis of the intestines; and, in the non-tuberculous, large cocci and spore-like forms which gave the same colouration as tubercle bacilli. Koch and Gaffky 14 could only recognise tubercle bacilli in the dejecta of the phthisical with marked symptoms of intestinal tuberculosis; they also confirmed the other researches of Lichtheim and de Giacomi on the presence of spores, which could be coloured like tubercle bacilli. Lastly, Wolfram 15 is to be mentioned, who 1 The Lancet. 1886. 2 Central. f. d. Med. Wissenschaft. 1883. No. 5. 3 Central. f. d. Med. Wissenschaft. 1883. No. 9. 4 The Lancet. 1883. 5 Wiener med. Presse. 1884. No. 37. 6 Berliner klin. Wochenschrift. 1884. No. 37. 7 Wiener med. Blatter. 1885. 22. Anthiel d. Tuberc. a. d Aetiol. App. Dissert. Berlin, 1885. Deutsche med. Wochenschrift. 1886. No. 15. Archiv. p. l. Scienz Med. Vol. X. No. 19. 10 Münchner med. Wochenschrift. 1887. 12 Ibid. 11 Ibid. 13 Fortschritte der Med. 1883. No. 5. 14 Mittheilungen aus dem Kaiserlich. Gesundheit. 15 Pracglad lek. 1884. |