August 27, 1891] 



NATURE 



m. 



poor classes, where the standard of health is exceedingly low 

 and the liability to catarrhal conditions very great. From a 

 series of inoculations with tuberculous udder, and with milk 

 from tuberculous udders, 14 out of 19, or over 70 per cent., had 

 given positive results ; with non-tubercular udders, and with 

 milk from otherwise tuberculous cows, only 2 cases out of 13, or 

 a little under 16 per cent., gcive positive results. Where the 

 failure to produce tuberculoses occurred in the first series, the 

 number of bacilli was invarialiy small, and inoculations were 

 usually into the subcutan3 us tissue, though negative results 

 were also obtained whe^ other methods of infection were 

 employed. They thought that in relation to the danger of 

 taking tuberculous milk by the human subject, the site of the 

 infection, and the relation of the number of bacilli introduced, 

 played an important part in determining the severity and 

 rapidity of the course of the disease, and they stated that their 

 experience accorded with that of other observers, that inocula- 

 tion into the peritoneal cavity is much more certain than 

 inoculation into the subcutaneous tissue, especially where the 

 number of bacilli introduced is comparatively small. They are 

 also led to believe, from a number of feeding experiments, that 

 the production of tuberculosis through the introduction of bacilli 

 into the alimentary canal is of still less frequent occurrence 

 than when inoculation is made into the connective tissue. As 

 regards the possibility of the flesh of tuberculous animals setting 

 up tuberculosis, (a) when introduced en masse, {l>) when expressed 

 juice only was exhibited, their experiments went to prove that 

 the juice only did not in most cases contain a sufficient number 

 of bacilli to set up tubercle, even when inoculated into small 

 rodents, but from the fact that they have observed tubercular 

 masses in the muscles of the buttock of tuberculous cattle, it must 

 be accepted that tubercle bacilli may sometimes, though perhaps 

 rarely, be present in considerable numbers in this position. Of 

 three cows slaughtered in one day at one slaughter-house, well- 

 definad tubercle was found in the muscles of the buttock of two 

 animals ; in one of these there was tuberculosis in every organ 

 and part of the body ; in the other there were only a few 

 nodules and in some of the glands ; there was certainly no 

 pleural or peritoneal tubercle, and all the other organs were 

 unaffected. They concluded that there was great necessity for 

 a thorough inspection of both dairy cattle and of animals that 

 were slaughtered for food purposes, but it might be accepted that 

 the danger of contracting tubercle from milk was greater than 

 that of contracting it from meat, and that only in a certain 

 proportion of cattle affected with tuberculosis did there seem to 

 be any danger to be anticipated from the ingestion of the flesh. 

 In the main they agreed with Prof. Burdon Sanderson and Dr. 

 Bang that there was not yet sufficient evidence on which to 

 decide that the total seizure of meat from tuberculous animals 

 should be resorted to. 



Prof. Hamilton, of Aberdeen, said that there were two prin- 

 cipal channels of infection, (i) the gastro-intestinal tract, (2) the 

 lungs ; but in addition to these we had what might be spoken of 

 as localized tubercle, which seemed to be shut off entirely from 

 all communication with the external world. (i) In the body 

 the affection might take place by the air channels, as in the case 

 of tubercular pneumonia, where the virus was probably inhaled 

 and the air vesicles were the primary seat of infection. (2) By 

 the blood vessels, as in cases of eruption of miliary tuberculosis. 

 (3) By the lymphatic vessels, as in the more chronic forms of 

 tuberculosis. In the gastro-intestinal canal a tubercular lesion 

 might accompany an ordinary phthisis ; it was often seen in 

 children as a primary condition, and he should not be inclmed 

 to agree with Dr. Burdon Sanderson that it was not also primary 

 in adults, as he himself had seen several cases, one quite recently. 

 Previous catarrh was not always met with in the lung, but it 

 was certainly a predisposing cause of tubercle, as it interfered 

 with the protective epithelial covering. When tubercle followed 

 whooping-cough, measles, and so on, it was probably the result of 

 the spread of infection from pre-existing caseous spots, or it might 

 be that the glands, weakened by the disease, fell an eaay prey to 

 the tubercle bacillus. He could not understand the comparative 

 immunity from tubercle enjoyed by the pericardium and the 

 stomach. 



Prof. Nocard, of Paris, did not think that sufficient proof 

 had as yet been accumulated that ingestion of tuberculous meat 

 could give rise to tuberculosis in any large proportion of cases ; 

 the greater number of experimental cases had given negative 

 results, and he should, to convince himself, require to see more 



positive results obtained in which all possible sources of failure 

 could bs eliminated. Whilst saying this, he must admit that in 

 the case of children tuberculous material, whether in meat 

 or milk, would always prove a very important source f)f 

 danger. He would draw attention to the disease as it occurred 

 in cats, on which animals he had made many experiments. 



Dr. Hime, of Bradford, was glad to find that our foreign 

 friends, who sre not hampered as we are in making experiments, 

 agree with us in the main. He thought that we were likely to 

 run wild on the subject of the total seizure of tubercular meat, 

 and he would point out that in no country does a total seizure 

 law exist such as it is proposed to adopt here ia England. In 

 England he would point out that the inspection is worse than in 

 any other country. He referred to Prof. Lingard's experiments 

 given in an official report, which, he pointed out, spoke only of 

 tubercle being transmitted by caseous material, and not by meat 

 from a tuberculous cow, as was usually assumed. We had the 

 authority of Koch himself, said Dr. Hime, that there is danger 

 only when tubercular material itself is ingested. Infection by 

 milk he looked upon as proved, but he would also insist very 

 strongly that the majority of infection in cases of phthisis was 

 directly between man and man, and it was far more important 

 that we should eliminate possible sources of contagion between 

 human subjects than that we should pay so much attention to the 

 minor possibilities of infection from animals to man. 



Dr, Barlow (London), speaking from a clinical point of 

 view, was scarcely able to indorse the results of experimental 

 researches, and he maintained that as regards tuberculosis in 

 children we must for the present keep our minds open. There 

 was no doubt that the poU-niortems in children's hospitals gave 

 evidence of the enormous frequency of tuberculosis, but the 

 evidence that such disease was the result of the ingestion of milk 

 and meat was comparatively slight. Other sanitary precautions, 

 which he looked upon as of primary importance, must not be 

 lost sight of in our discussion of the subject. He would, how- 

 ever, enter a protest against the use of the raw meat juice in the 

 case of delicate children, as from what we had heard it was 

 evident that such aliment might prove a source of considerable 

 danger. 



Prof. Perroncito, of Turin, referred to a number of experiments 

 that he had carried out with meat, milk, and the products of 

 the latter, and then pointed out that spontaneous tubercle very 

 rarely occurred in the pig, though it might frequently be met with 

 as the result of infection. The same might be said of sheep. 

 Here, also, it might occur, though rarely, as the result of direct 

 infection. 



Prof. Burdon Sanderson, in reply, said he was pleased to find 

 that the difference of opinion amongst so many authorities was 

 so slight. It was evident that all were agreed that inspection 

 was necessary, and there was also a general consensus of opinion 

 as regards the difficulty of diagnosis. He wa-; glad to find that 

 although M. Arloing still retained his opinion as to the necessity 

 for total seizure, except under very well-defined conditions, he 

 had so far given way as to acknowledge that such meat might after 

 careful cooking be retailed under special restrictions. In order 

 that something definite might come out of this discussion, he 

 proposed that it be minuted that "the etiology of tubercular 

 disease of early infancy (between three months and five years) " 

 be referred for discussion at the next Congress. 



This was seconded by Dr. Septimus Gibbon, and was carried 

 unanimously. 



The President said that he had been greatly interested in the 

 discussion, and he hoped that much good should arise therefrom. 

 He wa-; glad to find that there were some animals, such as the 

 sheep and pig, in which spontaneous tubercle was never met 

 with, and he hoped that we might eat these in safety. Sheep 

 especially appeared to have a great immunity as regards tubercle, 

 but pigs were not so safe, as they were apparently frequently the 

 subject of tuberculosis. 



Dr. Metschnikoff and Dr. Roux gave a joint paper on the 

 changes that took place in the tissues around tubercle bacilli. 

 It was read by the former, who illustrated his remarks by means 

 of drawings on the black-board, and by microscopic specimens. 

 They indicated the difference in the reaction of our tissues to the 

 tubercle bacilli when the disease is going to run a favourable 

 course, and when the animal is about to succumb rapidly to the 

 disease. The process of recovery was indicated by the presence 

 of concentric rings of hard and inflammatory tissue around the 

 bacilli, which eventually lead to their absorption, the inflam- 

 matory tissue itself finally undergoing a process of calcification. 



NO. II 39, VOL. 44] 



