128 BOVINE PATHOLOGY. 



the tuberculous or non-tuberculous characters of deposits in 

 connection with serous membranes, as the pleura. Our 

 decision in each case must be carefully arrived at. Gene- 

 rally, the occurrence of isolated tumours of rounded lobu- 

 lated masses and of indications of other scrofulous lesions 

 will enable us to diagnose scrofula. There is but one 

 cause of scrofula, the specific element, but there are many 

 determining influences. Neglect of sanitary measures, 

 exposure, changed climatic conditions (notably cold, with 

 dampness). Debilitating influences, especially excessive 

 and prolonged lactations, all act in this direction, and must 

 be corrected as a prophylactic measure ; but they in 

 themselves are not able to originate the disorder in so 

 far as we know. The specific element comes from the 

 parent or from without. Fresh blood must be introduced 

 into a herd with a scrofulous tendency, breeding in-and- 

 in avoided ; also, perhaps, we shall shortly admit that 

 measures of disinfection are necessary in this disorder, for 

 it has been shown that animals standing side by side and 

 feeding out of the same manger and drinking from the same 

 trough or bucket have both succumbed, one only having 

 been at first affected. It has been stated that tubercle is 

 communicable by inoculation, but this is not yet absolutely 

 proved, for it has been found that local irritation of any 

 kind will determine development of tubercle. Chauveau 

 long ago caused tuberculosis in cattle by feeding them -on 

 scrofulous products (^ Gaz. Med. de Lyons,' 1860, p. 550). 

 The intestines were affected in this case. The experiment 

 has been frequently successfully performed on other 

 animals, as dogs, poultry, and guinea-pigs. Bollinger's 

 experiment with milk is remarkable. He took half of a 

 litter of pigs from a healthy sow, and fed them with milk 

 from a phthisical cow. The state of the cow was proved 

 by autopsy. The pigs were destroyed at regular intervals, 

 and those kept on the milk of the sow were found to be 

 healthy, while those fed with the scrofulous milk were all 

 more or less affected with tuberculosis. 



It is most important to decide what relation tubercle in 

 man bears to tubercle in the lower animals. The milk 



