August 27, 1891] 



NATURE 



395 



quently on tuberculous disease of the lungs, but in the remainder 

 the disease seemed to be primary. If it could be proved that 

 such cases were primary, the fact would afford clearer evidence 

 than any we now possess of the enteric origin of tuberculosis. 



In the absence of such proof, human pathology had very little 

 indeed to say in favour of the belief that human tuberculosis 

 could owe its origin to the consumption of tuberculous food, and 

 even if it were proved that the absorbents afforded a channel of 

 entry for the tuberculous virus in children it would have little 

 significance as regards the consumption of meat. 



The author held, therefore, that we are not as yet in a position 

 to demand the interference of the State on the ground that the 

 community actually suffers from the consumption of tuberculous 

 meat, the evidence that it is so being too weak to be insisted on ; 

 but he maintained that the consumption of tuberculous meat 

 was attended with some danger, and that on that ground its 

 consumption ought to be prevented by the State and avoided by 

 the individual. 



As regards the administrative question, he held that if we had, 

 to-morrow, a law forbidding the sale of any meat containing the 

 bacillus of tubercle, it could not be carried out unless those 

 charged with its administration were able to distinguish such 

 contaminated meat from healthy meat, so that the efficiency of 

 the law would depend on the question whether the art of 

 discriminating between infecting and non-infecting meat had 

 attained to such perfection as to enable an adequately trained 

 inspector to exercise his function with effect. The practical 

 result to which we have come was this. Everything must 

 turn on diagnosis. The Legislature might direct that all meat 

 intended for consumption should be subjected to inspection, 

 might appoint inspectors, impose penalties, and provide just and 

 adequate compensation, but all this would be of no use unless 

 the principles on which the discrimination of infecting from non- 

 infecting meat is to be founded could be laid down, and the 

 services of skilled persons of sufficient intelligence to apply 

 them could be secured. We might consider it quite certain 

 that in this country at least it would at present be extremely 

 difficult to find such persons. Not that the veterinarian was less 

 capable than the doctor of making a scientific investigation, but 

 that he does not possess, and has, as yet, had no opportunity of 

 acquiring, the sort of skill which is necessary for making what 

 the French call the diagnose precoce of tuberculosis. Two things 

 in short are required, neither of which we have at our disposal — 

 special scientific knowledge and technical skill, and the former 

 of these must be acquired first. Science must determine, much 

 more definitely than has been done as yet, what are the earliest 

 changes which have their seat in the parfs of animals used for 

 food, and which of these might indicate danger to the consumer. 

 This knowledge could only be acquired by experiments specially 

 made for the purpose, and having been attained it could only be 

 applied by technically trained persons. He illustrated the sort 

 of skill required by comparing it to that possessed by the pro- 

 fessional tea taster as regards the commercial value of tea. Why 

 was the judgment of the expert reliable? Because he was 

 responsible for it and was paid for it. It would be the same as 

 regards the early recognition of tubercle in cattle, if skill and 

 discrimination were paid for ; and the same moment that this 

 skill was required it would come into existence. What would 

 be wanted in the inspector was not that he should be a patho- 

 logist or even a bacteriologist, but a trained expert ; for although 

 the rules unconsciously used by him might be based on scientific 

 principles, it is "not by these principles he is guided in each case, 

 but by practical skill. 



Dr. Sanderson then submitted the following propositions to 

 the meeting of the combined Sections : — 



(i) That tuberculosis must be added to the list of diseases 

 regarded by the law as contagious. There is no sufficient reason 

 for supposing that in the human adult the introduction of the 

 bacilli of tubercle by enteric absorption is the efficient cause of 

 tuberculosis. In infancy a large proportion of the apparently 

 idi ipathic tuberculous diseases of the lymphatic system are 

 probably due to the penetration of bacilli into the organism 

 from the intestine ; but the evidence which we at present possess 

 on this subject is not sufficiently precise or extended to serve as 

 a basis for prophylactic action. For this reason the origin of 

 tuberculosis in infancy is a subject which urgently requires 

 investigation. 



(2) It has been proved that the ingestion of any material 

 which contains the bacilli of tubercle is a source of risk to the 

 consumer, but the conditions which limit this risk are insuffi- 



ciently known. It would, therefore, be unjust to enforce the 

 destruction of any specimen of meat apparently healthy, even 

 though it were known to be derived from a tuberculous animal, 

 excepting on evidence given as regards the particular case that 

 it would be infecting if administered to test animals. 



(3) As regards the duty of the State in relation to the pre- 

 vention of tubercul isis, what is immediately required is that an 

 efficient system of skilled inspection should be created. This is 

 desirable, not merely as a first step towards a prevention of the sale 

 and consumption of tuberculous meat, but as an indispensable 

 means of acquiring better information than now exists. To be 

 of use it must be carried out on the principles I have already 

 set forth. It must be conducted by men of technical skill 

 acting under scientific guidance. 



"In conclusion," said Dr. Sanderson, "I would beg you 

 to notice that I have limited myself to the question of the 

 consumption of meat. Although I have purposely left the 

 milk question out of consideration, I have referred to facts 

 which bear upon it. We have seen it to be exceedingly 

 probable that about 40 per cent, of the children that die 

 in hospital, die tuberculous. I have already expressed my 

 belief that in some of these cases the disease is congenital — that 

 is, dependent on causes which have operated before birth. 

 Some are probably infected by inhalation of the tubercle bacillus 

 from the atmosphere, notwithstanding that pathology affords so 

 little evidence of it ; but for the rest, notwithstanding the lack of 

 satisfactory evidence, I cannot resist the conviction that the con- 

 sumption of unboiled milk during the years which follow weaning 

 must have its share in bringing about the fatal prevalence of 

 tuberculous disease at that period of life. This being the case, I 

 feel that, whatever course may be taken as regards meat, I can 

 join heartily with those who think that the sale of contaminated 

 milk ought to be put a stop to by all possible means, and I trust 

 that on this subject there will be no difference of opinion, and 

 that this Congress will take such action as may promote the 

 progress of legislation." 



Dr. Bang, Lecturer in the Royal Veterinary College, Copen- 

 hagen, in a paper on " The Alleged Danger of consuming the 

 apparently Healthy Meat and Milk of Tuberculous Animals," 

 stated that the great majority of investigators are agreed that 

 the essential source of tuberculosis in man is found in man 

 himself; but almost all admit that he may contract the disease 

 through the ingestion of milk derived from animals affected 

 with tuberculosis. 



It is always agreed that such a danger exists, but as to the 

 extent of the danger there is little unanimity. 



Of course, it might be said that there would be no danger if 

 the use of meat and milk from the tuberculous animals were 

 entirely interdicted ; but it must not be ignored that the applica- 

 tion of such a stringent measure would entail enormous loss 

 from an economical point of view, especially in those countries 

 where the disease has a very wide distribution amongst bovine 

 animals. He looked upon the general application of the French 

 regulations as out of the question, at least for the present, 

 whilst such a course appeared on the whole to be unnecessary. 

 As regards milk, the question of prophylaxis was comparatively 

 easily settled if it was resolved that it should never be employed 

 without first being boiled. But then the question comes to be, 

 How can we protect ourselves against the products of milk? 



The experiments made by Galtier, the author. Hum, and others 

 have proved that the various products derived from milk, butter, 

 cream cheese, cheese, and butter-milk may all contain tubercle 

 bacilli, and that these retain their vitality in such products for a 

 period of from fourteen to thirty days. It was true the majority 

 of these bacilli may be separated from milk if the cream be re- 

 moved by means of a centrifugal machine, as is generally done 

 in Denmark, but if the milk is very rich in bacilli a few usually 

 remain in the milk, and even in the cream. In order to do away 

 with this danger it is necessary to expose the milk or the cream 

 before churning to a temperature high enough to kill the tubercle 

 bacilli (85° C. for about five minutes); a temperature of from 60° 

 to 75° C., however, being quite sufficient to attenuate the organic 

 virus, so far as to render it incapable of setting up infection of 

 the alimentary canal. This method is coming more and more 

 into use in Denmark, as by it several other sources of infection in 

 the butter are also neutralized. As, however, many people object 

 to the taste of boiled milk, it became an important question to 

 determine whether the milk of phthisical cows is really a source 

 of danger in the majority of cases. He had determined 



NO. 



II 39, VOL. 44] 



