PREVENTIVE MEDICINE 259 



on a plate in a thin layer and heated to 100 C-104 C for 7 hours 

 in the case of the first vaccine and to 90-94 C for 7 hours in the case 

 of the second. The dried vaccine is then ground up to a powder 

 and mixed with sterile water in the proportion of 1 centigram to 

 4 c.c. liquid, which is the dose for a yearling calf. The injection 

 is made beneath the skin near the end of the tail, and after ten days 

 the injection of the second vaccine is made a little higher up. 

 M'Fadyean showed that the vaccines of Arloing, Cornevin and 

 Thomas can also be applied to sheep. (2) Kitt's method is a 

 modification of the last, and consists in exposing the dried virulent 

 muscle prepared as above to steam at 100 C for 6 hours. The 

 material is then dried. One decigram of the dried powder is used 

 as a single vaccine injected subcutaneously behind the elbow. The 

 duration of immunity from each method is said to be about 1 year. 

 Both procedures, and especially that of Arloing, Cornevin and 

 Thomas, have been in general attended with excellent results, the 

 mortality in nearly half a million animals inoculated having been 

 less than per cent., while among animals uninoculated the mortal- 

 ity has reached 1-74 per cent, (figures given by Strebel quoted by 

 M'Fadyean).* The disadvantages of the methods are that at times 

 the mortality may in the case of individual herds amount to 2-5 

 per cent., due most probably to a more than usually high suscept- 

 ibility on the part of certain animals. (3) Leclainche and Vallee f 

 have devised a method which they say is safer and gives certain 

 immunity. It consists in giving subcutaneously at the shoulder 

 10-20 c.c. strong anti-black-quarter serum, and in 5-8 days 1 c.c. 

 pure culture which has been heated for 3 hours at 70 C. Of 648 

 animals from badly infected districts inoculated only -15 per cent, 

 died. If considered necessary a second vaccine heated to 65 C 

 may be given. 



MALIGNANT (EDEMA. 



Malignant cedema (hospital gangrene) is an acute inflammatory 

 condition arising in connection with wounds and caused by an 

 anaerobic sporing bacillus, the bacillus of malignant oedema. The 

 disease may be met with in all animals, but it is most frequently 

 encountered in horses. The sheep is also susceptible, but the ox 

 and dog are more resistant. The organism is a saprophyte and 

 a normal inhabitant of the soil and of the intestinal canal of herbi- 

 vorous animals. For this reason and owing to its comparatively 



*Journ. Comp. Path., 1898, Vol. XL, p. 157. 

 t Journ. Comp. Path., 1903, Vol. XVI., p. 7. Trans. 



