TUBERCULOUS MEAT AND ITS CONSEQUENCES.

Temuka Leader, Issue 2135, 9 December 1890, Page 4

TUBERCULOUS MEAT AND ITS CONSEQUENCES.

Koch's brilliant discovery of the bacillus has set at rest all doubt as to j the cause of tuberculosis, and as to the question of its identity in man and tbe lower animals. No subject'has more uninterruptedly engaged the attention of pathologists during the past 12 months, or is more likely to lead to results of the greatest practical importance. It has been discussed in the legislative assemblies of Europe and America with a view to the settlement of manifold difficulties, legal and scientific, by which it is surrounded ; and public attention having , been thoroughly roused to the gravity of the issueß at stake, their solution is imperatively demanded in the interests alike of the large and important classes engaged in the supply of food to our markets, and the immeasurably larger and more important classes engaged in its consumption. The links in the chain of scientific evidence, based upon experiments conducted through a series of years, may be thus formulated: (1) Tuberculosis is caused by a minute vegetable organism, the bacillus ; (2) this organism is identical in man and the lower animals, any slight apparent difference being purely morphological; (3) the disease is communicable from cattle to the human subject; (4) one of the most frequent methods of this communicability is the ingestion of the flesh of animals specifically affected ; and (5) the ordinary modes of cooking do not destroy the bacillus, and have absolutely no effect upon the spores which are the chief means of its propagation. Professor McFadyean stated before the Privy Council Commission that cooking can never be relied on as a sufficient preventive ; ordinary cooking is insufficient to destroy the bacilli, and utterly incompetent to affect their spores, which requires a much higher temperature to become devitalised; and all evidence shows that the usual cooking of joints of beef and other parts is not sufficient to raise them even to 160 deg., the temperature at which blood coagulates, and therefore insufficient to destroy the bacillus; and Sir Charles Cameron, Mr Lingard, and Professor McCall, experts of the highest authority, examined on the same occasion, confirmed this opinion. The medical officers of the Local Government Board in their laßt report concur in the tenacity with which the spores resist all destructive agencies, to the extent indeed that ne known process is competent to deprive them of vitality ; and the committee of the North of Ireland branch of the British Medical Association Btate that the heat to which the inside of a large roast is raised is insufficient to destroy infectivity. The growth of a bacillus may be arrested at a temperature below 82deg, but it does not die : it can be slowly killed by being subjected i for several weeks to a temperature of 107.5 deg., and dies if exposed to boiling point for half an hour ; but a shorter exposure to this heat fails as a bacillicide, for in sixty-two experiments with a tuberculous flesh soaked in boiling water for ten to fifteen minutes, positive results as to infection by feeding were produced in thirtyfive per cent. So great, indeed, is the vitality of the bacillus that Koch still obtained the active microbe after conveying it through thirty-four generations of culture, for a time extending over twenty-two months; and the spores, the committee add, are far more tenacious of life. That the bacillus resists the action of the gastric juice and other fluids of the alimentary canal was first demonstrated by MM. Straus and Wurtz, and later investigations have confirmed the results at which they arrived Dr Coats, the pathologist to the Royal Western Infirmary of Glasgow, says : "'•hat the juices of the alimentary canal are proved not to be fatal to the bacillus is shown by the frequency of tuberculosis of the intestines following tuberculosis of the lungs." It might, then, be thought that if the bacillus had resisted the effects of cooking and of the fluids of the alimentary canal, no further impediments existed, and it would be at liberty to pursue its career unchecked, secrete its specific virus, and propogate its kind in the tissues. But happily, this is by no means the case, and it is chiefly after its entrance, together with the products of digestion, into the lymph and bloodT streams that its struggle for life commences. We are! but at the threshold of our knowledge of this subject, one of the most deeply interesting of the problems of pathology, and one which holds out the brightest hopes of our ultimate success in dealing with the large aDd deadly class of specific diseases. Wherever the bacillus comes in contact with these wandering cells, whether prior to or after its entrance into the stream of circulation, or when it has succeeded in effecting a lodgment in any of the tissues, a struggle takes place between the contending hosts, on whose result depends the issue of life or death to the part—eventually it may be to the entire body. In some cases, happily the great majority, where the constitution is unimpaired, the result is favorable to the cells, and the bacillus perishes; in others, where the tissues are weakened and the pblagocytes share in the debilitated condition—whether produced by heredity or any depressing cause —the bacillus triumphs, finds a nidus suitable to the needs of its existence, propagates its kind and leads to the development of a tubercular lesion. How constantly

thiß struggle * is- being waged may j be conceived from the fact that it has been calculated by Bollinger that otie, phthisical person may eject from his j body in the course of twenty-four \ hours twenty Millions of ;the ; bacilli. It may, then, be taken as proved,that ttie;bacillu!j,in all j cases',ju» r dem;e<i by one animal rfrotn .another, an 4 g row * only at a temperature approaching that of the human body ; its chief if not its only place of multiplication is in the living tissue, and when it has found a suitable .reding place it commences its mission, propagating by spores and by. fission, and secreting alkaloids dangerous to animal life, and leading to an alteration in the normal structure by the formation of tubercles, such lesions being, an absolutely characteristic sign of the disease.