62 ABSTRACTS.

and training. The authors consider that the h<emoglobinuria was due to chill, and give reasons in sllpport.

The dissemination of this disease, which the authors have named North­African surra, cannot be due to the tsetse fly, which does not OCCllr in Algeria. It is probably due to gad-flies.

It might be of interest to study the part played by ixodides in the spread of trypanosomiasis. During certain seasons of the year these acari attack horses and become attached at points where the skin is fine. May it not be possible that, as ticks produced by females which have lived on animals suffer­ing from piroplasmosis are capable of transmitting the disease, the same may be true of trypanosomiasis?

Treatment.-The authors have made a few experiments in treatment. They find that arsenic causes the parasites rapidly to disappear from the circulation. They consider that to be effective the treatment of trypanosomiasis in general should be undertaken early and persevered with. The visceral troubles and the extensive abdominal exudates in which the trypanosomata live and multiply may thus be prevented, and the danger of auto-inoculation on withdrawal of the drug may be avoided. (J. Roger and Greffulhe, Rev. Vet., No. 12, 1st December 1905, p. 801.)

------------

THE ACTION OF HEAT ON THE VIRULENCE OF TUBERCULOUS MILK.

IN 1889 Bang made a series of experiments consisting in injecting rabbits with tuberculous milk heated to 50°, 55°, 60°, 65°, and 70° C. Milk heated to 65° C. still produced tuberculosis. Rabbits injected with milk heated to 70° C., and killed seven and a half months later, proved to be free from tuberculosis. In another series of experiments it was found that tempera­tures of 62°, 67', and 70° C. were insufficient to sterilise tuberculous milk. Rabbits injected with it, when kiIled six and a half weeks later, proved to be infected.

Further experiments made with mixed samples showed that a temperature of 80° c., continued for five minutes, ensured sterilisation. Milk obtained from a chronically tuberculous udder was heated to 65°, 70°, 72°, 80°, and 85° C.; the results appeared to indicate that sterilisation was complete at 80° to 85° C. None of the animals injected showed any lesions when examined post-mortem three and a half months after injection.

Other experiments made with milk heated to 70°,75°,80°,85°, and 100° C. for five minutes showed that a temperature of 85° to 100° c., maintained for five minutes, rendered the milk harmless, whilst lower temperatures failed to prevent infection.

One sample of milk, very rich in tubercle bacilli, when heated to 80", 85·, and 100· C. gave similar satisfactory results. These experiments caused Bang to conclude: (I) that a temperature of 80· C. was sometimes sufficient .to ensure the sterilisation of tuberculous milk; (2) that a temperature of 85' C removed all danger; (3) that even after heating 'to roo o C. the formation of toxins was still easy.

Forster in 1892, after a series of experiments, concluded that heating to 70. C. for five or ten minutes was sufficient to sterilise tuberculous milk and tuberculous pus. De Man in r893 killed tubercle bacilli by heating to 55° C. for four hours, to 60° C. for one hour, to 70° C. for ten minutes, to 80· C. for five minutes, and to 95° C. for one minute; and Smith found that tubercle bacilli mixed with physiological salt solution, bouillon, or milk, were effectively destroyed at 60° C. after fifteen to twenty minutes' heating, and

ABSTRACT~.

usually even after five to ten minutes. He observed that, in the pellicle of caseine which forms, the temperature did not rise beyond 60· C. unless the liquid were stirred during boiling, and that tubercle bacilli included in it might retain their vitality even after an hour's heating. Mar Beck (1900) found that milk to which tubercle had been added could be heated to 100° C. for three minutes ~ithout being sterilised. Galtier proved that tempera­tures of 70°, 75°, 80·, and 85· c., continued for six minutes, were sometimes insufficient for sterilisatIOn. Finally, Norgeurdt showed that a temperature of 70. C. continued for half an hour, or of 100° C. continued for three to five minutes, was sufficient.

Barthet and Stenstrom endeavoured to formulate exact conditions for the sterilisation of tuberculous milk. The milk obtained from an extensively diseased udder, was clear and granular. It was heated in a water bath, and the temperatures were checked by means of thermometers graduated to

c . "'" 00 ~"'" :;: :;:

~ ;e " " "&~ ~ ~~. ~~ " -g~ i~ ~ Control I nocttlation.,

.~ .~ ~:E ReS1tlts of the A 1ttopsies made with Un-' t; '- "t :::' ""'~~ on Guinea-pigs.

'- "..e heated Milk. ~ !} ~.~ ~~ .~ ~~

"'l ~~ ~S ~

----------------------- ---------lIlin1,tes. Days.

1. I 65 5 67 Died. Numerous tu- Rabbit. Died in berculous centres twenty eight in the organs days. Tuber-

culous. 2 65 10 64 Killed. Numerous tu-

berculous centres 3 65 15 68 Died. Tuberculosis

in all the organs II. 4 70 5 50 Died. Numerous tu- G~inea-pig. Died

berculous centres In seventeen days. Tuber-culous.

5 70 10 40 Ditto. 6 70 15 90 Killed. A few tuber-

culous lesions III. 7 75 5 I Died of peritonitis. Guinea-pig. Died

Accident of peritoniti~. Accident.

8 75 10 79 Killed. Tuberculous. 9 75 15 13 Killed. Small tuber-

culous centres IV. 10 80 I 94 Killed. Many tuber- Guinea-pig. Died

culous centres of peritonitis in thirteen days. Numerous tu-berculous cen-tres in the spleen.

II 80 5 94 Killed. Small tuber-culous centres

12 80 10 75 Died. Numerous tu-berculous centres

A

0;

ABSTRACTS.

tenths of a degree. Their first series of experiments confirmed the results obtained by Bang; that is to say, guinea-pigs intraperitoneally inoculated with milk heated for five to ten minutes to 60° C. became tuberculous. After using heated milk, death was deferred (in one case for as long a period as seventy-five days), or the animals survived so long that the conditions of experiment rendered it necessary to kill them (two animals were killed after the lapse of ninety-four days). Control guinea-pigs inoculated with tuber­culous milk died much more rapidly. The results are given in the foregoing table :-

Storch's experiments showed that milk from tuberculous udders is more alkaline than normal. The authors believed that this increased alkalinity might have some bearing on the manner in which the tubercle bacilli

.s;~ .~ ;:"" ~~ '& "''' it ~~ "'''' .~ ~~ ~.:.i "'~g, Control Inocula-~.S ~ ~ ~~ ~~ ~"-& A utopsy of Guinea-

~ .o~O pigs Inoculated with tions made with ... '" .'£ ~ Q.)~~ . ~ ~~ ~~ ~.§ Heated Milk. Unheated Milk . $ ~ ~~

.~ 6~ "..<2 ... 0 ... :il ~ ----------------------------------

Minutes. Days. I [80 I Alkaline Homo- 49 Killed. Not diseased Dead In five

genous days. Peri-tonitis.

2 80 I Strongly Coagu- 36 Died. Numerous tu- Dead in twenty-acid lated berculous centres seven days.

Tuberculous. 3 80 5 Alkaline Do. 41 Died. Not diseased.

Cause of death un-known

4 80 5 Strongly Do. 46 Died. Numerous tu-acid berculous centres

5 85 Mo- Alkaline Homo- 32 Died. Not diseased. Dead in twenty-men- genous Cause of death un- two days. tary known Tuberculous.

6 85 Do. Strongly Coagu- 48 Killed. Numerous tu- Killed on the acid lated berculous centres twenty-seventh

day. Tuber-culous.

7 85 I Alkaline Homo- 32 Killed. Diseased but Killed on the genous not tuberculous eighteenth

day. Tuber-culous.

8 85 I Strongly Coagu- 50 Died. Tuberculous acid lated

9 80 5 Neutral Homo- 50 Killed. Not diseased Died on twenty-genous first day.

Tuberculous. 10 80 5 Alkaline Coagu- 39 Died. Tuberculous

I lated

behaved under the action of heat. They therefore tested the question by heating normal milk to which had been added tuberculous pus rich in bacilli. The milk was divided into three equal portions, one of which was

ABSTRACTS.

re1dered alkaline with decinormal solution of soda, the second acid with decinormal solutIOn of sulphuric acid, and the third of which was reserved as a control. The solution of pus (consisting of 25 cc. mixed with 10 cc. of sterile water) was intimately incorporated with the milk. The mixture was heated to 70° C. for ten minutes, and it was found that 10 cc. of this milk when injected into the peritoneaL. cavity of a guinea-pig produced tuberculous lesions in fifty-four days.

The guinea-pigs inoculated with alkaline and acid milk showed extensi \ e tuberculo,is, those with normal milk much less marked disease. Two control guinea-pigs died from peritonitis.

From Bang's experiments it appears that the chemical reaction of the milk is of minor importance, but that the physical properties are of considerable interest. Anything which favours coagulation of the caseine and envelopment of the tubercle bacilli causes the latter to offer great resistance to the action of heat. Barthet and Stenstrom confirm this view. They used tubercle bacilli obtained by centrifuging. The tuberculous milk had a specific gravity of 1'02 r. Its degree of acidity on Thorner's scale equalled seven. It gave 7'1 of solid residue on evaporation, containing '63 per cent. of fat, 4'3 per cent. of albuminoids, '9 per cent. of lactose, and yielded '78 per cent. of ash. One portion of the milk was rendered neutral by adding decinormal solution of soda. Another was made strongly alkaline so that it could be heated to 90° C. before coagulating. The remainder was of &Iightly acid reaction and coagulated even at a temperature of 60° C. The alkaline and slightly acid milks were heated to 80° C for varying periods, but it was always found that if the caseine were allowed to coagulate the tubercle bacilli offered much greater resistance.

The practical conclusions, therefore, to be drawn from Barthet and Stenstrom's experiments is, that heating to 80° C. for one minute is sufficient to kill the tubercle bacilli provided the milk does not coagulate during the operation. From one and a half to two minutes is in all cases sufficient to remove danger. (Barthet and Stenstrom, Le Bulletin Veterinaire, ex Ann. de MM. vet., 1905, page 510).

THE MICROBIC FLORA OF THE NASAL CAVITIES IN THE HORSE.

CERTAIN microbes pathogenic for man and animals are fot\nd in forage, in the animal's usual surroundings, and in the digestive and respiratory tracts. Such of them as are n6rmally present in the healthy animal body po~sess considerable interest as being possible causes of disease. Among these may be mentioned streptococci, staphylococci, coli bacilli, and examples of the order Pasteurella.

Investigations bearing on this subject have been carried out by Porcher, Porcher and Desaubry, Bisanti, Baruchello and others, and various organs have been examined, but De Angelis does not think that the nasal cavities of the horse have yet been carefully studied.

His observations apply to ten horses, aged respectively six, eight, ten, and twelve years, all in perfect health and stabled either at the Research Labora­tory or at the Riding School of the Alfort Veterinary School.

The material studied was collected with the most scrupulous regard to asepsis, by the use of wires provided at one end with a pledget. of cotton wool, previously sterilised and protected within the usual tube. As soon as obtained the material was sown in peptonised bouillon, bouillon containing

E