ABSTRACTS.

The amount paid in compensation was reduced, slaughter was delayed, and the tuberculin test became permissive. But in the two years 1895 to 1897, 9280 animals were destroyed fruitlessly.

To-day it cannot be allowed that apparently healthy cows in excellent condition and yielding milk free from tubercle bacilli should be excluded from milk production or compulsorily slaughtered simply on the grounds of a positive reaction to tuberculin. But it is desirable that all infected milch cows which are sources of infection should be detected and destroyed. On the contrary, if in every herd the sale of reacting milch cows were forbidden except for butchers' purposes, the supply of milk would immedi­ately fall by one-third, and, other things being equal, the price already high, would rise in proportion. No advantage, however, would accrue to public health.

Public health would reap far greater benefit if only milk which had been rendered free from living tubercle bacilli by boiling could be sold, especially for children, except when it was obtained from cows regularly tested and kept under veterinary supervision, and sold only in sealed vessels.

The measure proposed by the Conseil d'Hygiene cannot therefore be accepted, and the Academie de Medicine cannot aprove of it. (Calmette: Rev. Vet., June, 1922, Vol., LXXIV., No.6, pp. 356-362.)

THE PERCENTAGE OF CATTLE AFFECTED WITH TUBERCULOSIS IN FRANCE.

IN this short article the author criticises some of M. Calmette's conclusions (see preceding Abstract) regarding the incidence of tuberculosis in cattle in France.

The figures used by Calmette purport to show that in December 1921 there were 18,268 infected premises and 144,065 tuberculous cattle. The logical deduction is that the number of tuberculous cattle in France is not less than 2,000,000. The author fears that these figures will be quoted in scientific and popular literature on tuberculosis as showing the extreme degree of infection in French cattle. In this wayan unmerited discredit may be thrown upon the stock at the very moment when supreme efforts are being made to find fresh markets, and a great handicap may be placed upon the export trade.

The author draws attention to what appears to be an error made by Calmette in interpreting the official statistics which magnifies the seriousness of the situation. One simple detail, but an importart one, has been forgotten, namely, that the information collected regarding the results of tuberculin tests carried out by veterinary officers relates almost entirely to infected herds which are tested because a case of tuberculosis has been discovered in them. Save in exceptional cases, herds which are not suspected are not tested, and when tests are carried out on suspected animals or fresh purchases only the positive reactions are reported. The

ABSTRACTS. 141

official statistics therefore give the percentage of reactors in herds known to be infected, and not of the whole of them. But there can be no doubt that premises which are suspected by the sanitary authorities contain a higher average of tuberculous animals, and that there are herds which are completely free from the disease. The importance of these last, from the point of view of the statistics, remains to be proved, but if they were subjected to the test the effect would be to lower the percentage of positive reactions.

The official figures refer only to premises which are as a rule the most seriously affected. There is not sufficient information to permit of any exact estimate of the incidence of the disease, but when the statistics of 20th December 1921 show that the infected premises contained 144,065 animals, these were" contaminated" animals (of which a certain proportion did not react to tuberculin), and not "tuberculous" animals, as stated in Calmette's report.

Although there is an impression that tuberculosis is on the increase, veterinary practitioners will scarcely admit that a third or a half of the stock are affected. If it were so cancellations of sales would be never-ending, and the cattle trade would be so upset that it would be necessary to make an immediate alteration in the law whereby a single reaction to tuberculin is sufficient to annul a sale.

The author states that the note has been written, not with a view to denying that bovine tuberculosis is increasing, but to put those who may be interested in the subject on their guard against the exaggerated estimate likely to be formed on the strength of statistics that are misleading when not fully explained. (Sausseau, Rev. Vet., June 1922, Vol. LXXIV., No.6, PP·362-3 6s·)

CHARACTERISTICS OF THE BACILLUS OF BLACKLEG.

IN this paper are described methods for the isolation of Bacillus chauvcei, and for its differentiation from other amerobes found in similar infections.

The organism with which Bacillus chauvcei is most frequently confounded is the vibrion septique. The differentiation of these two from most other ancerobes found in similar infections is facilitated by the fact that they do not form proteolytic ferments. The media used by the authors were Hibler medium, 2 per cent. dextrose agar, liver broth, and liver agar. The following are the details of the preparation of these :-

Hibler Medium.-Beef liver 500 grammes and brain 500 grammes are ground, and to the liver are added 1000 cc. of water. Both are steamed for an hour. The liver broth is strained through cheese cloth and cotton, and I per cent. peptone and '5 per cent. salt are added. The broth after titration to PH 8'2 is tubed, and brain is added in the proportion of one part to two of broth. The tubes are autoclaved for an hour at IS lbs.

Dextrose Agar.-Beef infusion (500 grammes per litre) has added to it I per cent. peptone, '5 per cent. salt, and 2 per cent. dextrose. The