NATURE 



393 



THURSDAY, AUGUST 27, 1891. 



THE CONGRESS OF HYGIENE. 



WE continue this week our account of the work done 

 at this Congress. It will be clear that with the 

 space at our disposal it is only possible to refer to 

 few among the many subjects discussed. Among these 

 we have selected those which have the closest 

 connection with those researches now attracting special 

 attention. 



In regard to the subject of tuberculosis it was cer- 

 tainly a happy inspiration of the officials of the Bac- 

 teriological (II.) and Comparative Pathological (III.) 

 Sections of the International Congress of Hygiene and 

 Demography, to call a joint meeting in order that a full 

 discussion of the scientific and practical bearings of the 

 questions relating to " the transmission of tuberculosis from 

 animals to man by means of flesh and milk derived from 

 tuberculous animals" might be possible ; and it was also 

 fortunate, as far as its success was concerned, that the 

 discussion was opened by Profs. Burdon Sanderson and 

 Bang, each of whom in his own sphere is singularly well 

 fitted to lay before the members of the Sections what 

 ia at present known in the medical and veterinary scientific 

 worlds concerning this important subject. Prof. Sander- 

 son's early researches on tuberculosis have opeied up 

 the way for much of our present knowledge on the sub- 

 ject, in addition to which he has watched the question 

 most carefully through its various stages of evolution ; 

 whilst Prof. Bang, by his numerous practical observations 

 and scientific experiments, has given a completeness to our 

 knowledge which has not been attained as the outcome of 

 the work of any other observer. 



The discussion on this question afforded another 

 instance of the intimate connection between the purest 

 research and the most practical affairs of every-day 

 life. 



Thus from the tenor of the discussion it may be gathered 

 that the danger arising from the ingestion of tuberculous 

 milk and meat has probably been exaggerated. 



Some of those who took part in the discussion, for 

 example, seemed to doubt whether primary tuberculosis 

 of the alimentary canal — i.e. tuberculosis confined to this 

 region and evidently the result of infection through the 

 mucous membrane— was ever met with in adults, and even 

 whether it was of very frequent occurrence in the child ; 

 whilst other speakers were able to instance out of their 

 own experience certain cases of the former and many of 

 the latter, strongly accentuating the fact that such primary 

 disease of the intestinal canal does exist. Then, again, 

 one speaker was convinced that Koch's bacillus had little 

 or nothing to do with the production of tubercular disease ; 

 but the contention had been met by so many accurate 

 observations and experiments that he may be said to 

 have been ruled out of court, though it was on all hands 

 agreed that the ba-illus might be helped in its work by 

 various predisposing causes, many of which were brought 

 into full prominence during the discussion. It was also 

 accepted that the tuberculosis of cattle is similar, as re- 

 NO. 1 1 39, VOL. 44] 



gards its causal agent, to the tuberculosis of the human 

 subject, and that the disease is merely apparently modified 

 owing to the different conditions, and perhaps delicate 

 tissue modifications, offered by the different hosts of the 

 parasitic bacillus ; and from the most careful and detailed 

 I experiments, of which a large number were described, 

 there seems to be no question that tuberculosis is com- 

 municable from animals to man, and certainly there 

 appears to be none that it is communicable in the opposite 

 direction. 



There was a general expression of opinion as the outcome 

 of the discussion that legislation of some kind or other 

 is necessary, but, as pointed out by Burdon Sanderson, if 

 laws were made to-morrow there is absolutely no staff of 

 inpectors capable of giving effect to any that might be 

 drafted. It is probable that this will draw attention, 

 first, to the necessity for conferring powers of inspection 

 of dairy and store cattle on some central authority ; and 

 second, to the necessity there is that our veterinary 

 surgeons should undergo a thorough scientific and 

 practical training, such as would fit them to fill the posts 

 from which unfortunately they are necessarily now in 

 many instances excluded. 



When all is said and done, it appears that the danger 

 arising from the consumption of tuberculous meat is far 

 less serious than that involved in the consumption of milk 

 from tuberculous animals, as meat, if thoroughly cooked., 

 appears to be perfectly innocuous, the tubercle bacilli being 

 readily destroyed by heat, whilst the nutrient properties 

 of the meat itself are little, if at all, interfered with by 

 judicious cooking. In the case of milk, however, in 

 which the presence of tubercle bacilli has been so often 

 demonstrated, it has to be borne in mind that boiling so 

 alters the constituents of the milk, especially the pro- 

 teids, that it is rendered very much less digestible ; and 

 its nutritive value is greatly interfered with. 



We now pass to the discussion. 



Tuberculosis in all its Relations. 



Prof. Burdon Sanderson said the subject which he had under- 

 taken to bring before the notice of the conjoint Sections for 

 discussion was one of the gravest importance, for there was no 

 disease, acute or chronic, which wa< so productive of human 

 suffering or so destructive of human life. In a Congress of 

 Hygiene the subject of tuberculosis could only be considered in 

 relation to its causes, the aim of hygiene being to prevent dis- 

 ease, not to cure it. He wished specially to direct attention to 

 those questions which relate to the dangers which are alleged to 

 arise from the use of tuberculous food, (i) Does general tuber- 

 culosis in man originate from intestinal infection? (2) If it 

 does, is it possible to guard against so fearful a danger ? For 

 the purpose of avoiding useless discussion on subjects on which 

 there ought to be perfect agreement of opinion, he asked that 

 certain fundamental propositions should be accepted as settled ; 

 such as, for example, the existence of a materies morbi \n the 

 form of the tubercle bacillus, its constant association with the 

 tuberculous process, and the identity of human with bovine 

 tubercle ; and also that it be assumed that any part of the 

 body of a tuberculous animal or any secretion of such an animal 

 would, if it contained tubercle bacilli, be a source of danger, and 

 that the use of such liquid or part ought to be prohibited or 

 avoided. This being understood, we were in a position to enter 

 on the questions which require answers, some of which are patho- 

 logical or etiological, the others practical or administrative. The 

 etiological questions might be said to relate to the three possible 

 ways in which a human being may be infected by tubercle — 

 namely, inheritance, pulmonary inhalation (atmospheric infec- 

 tion), and food (enteric infection). The practical issues were — 



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