THE CONQUEST OF DISEASE 



spontaneously in hungry dogs. Attempts to 

 produce hydrophobia in dogs by starving them 

 were made by Radi and Bourgelat, and were 

 negative. 



It was observed that the disease was most 

 prone to develop in dogs that were given the 

 largest measure of liberty. The idea that 

 angry or excited dogs could cause rabies by 

 their bite was held by the laity and is even now 

 believed by the uninformed. Studies continued 

 and the lines of observation were fast closing 

 around the infectiousness of the disease. 

 Thamhayn collected 19 cases, 18 of which were 

 fatal, occurring in human beings who had been 

 bitten by dogs which were apparently healthy 

 but which subsequently became rabid. Then 

 Hertwig made his experiments. He inocu- 

 lated 30 dogs with the saliva of dogs either 

 dead or suffering with rabies, with the result 

 that 17 of the animals developed the disease. 

 He made experiments to discover if the infec- 

 tion could be conveyed through the food or 

 other intermediate vehicles, all with negative 

 results. In no other way was he able to 

 produce rabies ; but he did find that many dogs 

 are immune. Bollinger believes that it is pos- 

 sible for inoculation to be conveyed from the 



106 



