74 Dr. E. Klein. [May 22, 



diseased portions of the lobules presenting appearances which in 

 microscopic character coincide with the appearances in the mucous 

 Membnu&e of the human fauces, pharynx, or larynx in diphtheria. 

 But the correctness of the above supposition, that diphtheria has its 

 seat in the lung of the cat naturally diseased, was proved by direct 

 experiment. Broth culture of the bacillus diphtherias was introduced 

 into the cavity of the normal trachea without injuring the mucous 

 membrane. The animals became ill with acute pneumonia, and on 

 post-mortem, two to seven days after, there was found extensive 

 pneumonia, and fatty degeneration of the kidney. The bronchi, 

 infundibula, and air cells of the inflamed lobules were found occluded 

 by, and filled with, exudation which under the microscope bears a 

 striking resemblance to human diphtheritic membranes, and in the 

 inuco-purulent exudation in the large bronchi and trachea the diph- 

 theria bacilli were present in large numbers. 



During the last ten or twelve years certain epidemics of diphtheria, 

 have occurred which were traced to milk, but the manner in which 

 that milk had become contaminated with the diphtheritic virus could 

 not be demonstrated, although the evidence as to the milk not having 

 been directly polluted from a human diphtheria case was very strong. 

 The epidemic of diphtheria that prevailed in the north of London, 

 in 1878, investigated by Mr. Power for the Local Government Board, 

 then the epidemic that occurred in October, 1886, at York Town and 

 Camberley, the epidemic in Enfield, at the beginning of 1888, and in 

 Barking, towards the autumn of 1888, were epidemics of this cha- 

 racter. Mr. Power, in his Report to the Local Government Board on 

 the York Town and Camberley outbreak, states (page 13) that a 

 veterinary surgeon had certified that the cows from which the infected 

 milk was derived were all in good health, but that two of the cows 

 showed " chaps " on their teats, and he adds that even two or three 

 weeks after the epidemic had come to an end the use of milk having 

 been in the meanwhile discontinued he saw at the farm one cow 

 which had suffered from chapped teats. At Enfield a veterinary 

 inspector had also certified that the cows were in good health ; but at 

 Barking the veterinary inspector found sores and crusts on the udder 

 iind teats of the cows. 



I have made experiments on milch cows with the diphtheria 

 bacillus, which appear to me to throw a good deal of light on the 

 above outbreaks of diphtheria. 



Two milch cows* were inoculated with a broth culture of the 

 diphtheria bacillus derived from human diphtheria. In each case a 

 Pravaz syringeful was injected into the subcutaneous and muscular 



* The cows had been kept under observation previous to the experiment for ten 

 days and were in all respects perfectly normal. 



