220 INFECTIVE DISEASES. 



mortality among the vaccinated and unvacoinated in localities where 

 the disease commonly occurs, it has been said that the results are 

 extremely favourable. The matter was investigated in this country 

 by a committee : of , the Midland Veterinary Medical Association, 

 and in the course of the experiments some surprising results were 

 obtained. Six calves and four sheep were vaccinated, and five 

 calves and two sheep were left unvacoinated as a control experiment. 

 The seventeen animals were subsequently inoculated with virulent 

 virus in the form of dried and powdered muscle. In forty-eight 

 hours all the sheep died, and all the calves exhibited a swelling at 

 the seat of inoculation. In another set of experiments, healthy 

 calves inoculated with fresh juice from the tumour in a case of 

 quarter-evil were not materially affected. The possibility of those 

 calves which possess a natural immunity being classed as protected 

 by the inoculation must be admitted, and the efficacy and safety 

 of the process is by no means established. 



Malignant CEdema. 



The disease known by surgeons as progressive gangrene, gan- 

 grenous emphysema, or surgical gangrene, has been shown by the 

 researches of Chauveau, Arloing, Eosenbach and Bab^s, to be 

 due to a bacillus identical with the microbe septique of Pasteur and 

 the bacillus of malignant cedema of Koch. The bacillus or its spores 

 may be spread by the neglect of antiseptics. The disease occurs 

 especially after compound fractures and gun-shot wounds. 



If a guinea-pig is subcutaneously inoculated with earth, putrid 

 fluid, or hay dust, death frequently occurs in from twenty-four to 

 forty-eight hours. At the autopsy the most characteristic symptom 

 is a widespread subcutaneous CEdema accompanied by air-bubbles. 

 This originates from the point of inoculation, and contains a 

 clear reddish liquid full of motile and non-motile bacilli. The 

 internal oi'gans are little changed, the spleen is enlarged and of a 

 dark colour, and the lungs are hypersemic, and have hsemorrhagic 

 spots. Examined immediately after death, few or no bacilU are 

 detected in the blood of the heart, but in that of the spleen, liver, 

 lungs, and other organs, in the peritoneal exudation, and in and 

 upon the serous coating of the abdominal organs, they are present in 

 large numbers. If, on the other hand, the animal is not examined 

 until some time after death, the bacilli are found in the blood of 

 the heart, and distributed all over the body. 



Bacillus CEdematis Maligni, Koch (Pasteur's Septicjemia). — 



