THE RAT AS A CARRIER OF SPIROCHÆTA ICTEROHÆMORRHAGIÆ, THE CAUSATIVE AGENT OF WEIL'S DISEASE (SPIROCHÆTOSIS ICTEROHÆMORRHAGICA)

1. On the basis of these findings, we conclude that the extermination of rats and field mice is a highly important prophylactic measure against Weil's disease.

2. The chemical composition of soil and water plays animportant part in the development of Spirochœta icterohœmorrhagiœ, and consequently in the spread of the disease of which it is the causative agent.