fever was known long before the introduction of cinchona bark into Europe, indeed it was known in the days of Hippocrates. Besides, even recently, numerous cases of black water fever have been reported amongst Europeans who had never taken quinine. Cardamatis mentions thirty-two such cases. Then, again, a number of physicians have administered quinine in large doses for the treatment of blackwater fever and have greatly vaunted its beneficial action. Quinine, undoubtedly, provokes in some the clinical manifestation of blackwater-fever infection. So, and probably much more powerfully, do chill and fatigue. But no one will contend that the latter cause the disease. Why then attribute it to quinine, which, logically, has no stronger claim?
3. The specific theory.— In 1893, in a paper read before the Epidemiological Society, I stated that, on account of its peculiar symptoms and geographical distribution, I believed blackwater to be a disease sui generis. In 1898 Sambon suggested, because of the striking analogies that its distribution, course, symptoms and morbid appearances have with the hæmoglobinuric fevers of cattle, horses, dogs and sheep, that blackwater fever might be a form of babesiasis. This view, which has been adopted by Blanchard and others, deserves consideration. It is quite reasonable to expect to find in man parasites belonging to this genus of the hæmoprotozoa, so abundantly represented amongst the animals most intimately associated with him. Certainly, of all the diseases of man of which the etiology is still obscure, none could be more appropriately ascribed to this group of parasites. The analogies between the hæmoglobinuric fever of man and the hæmoglobinuric fevers of cattle are most striking. To explain the fact that as yet no babesia has been found in cases of blackwater fever, I might suggest that either the amœboid forms of the parasite have been mistaken for the early forms of the subtertian parasite, or that the parasite has escaped observation on account of diminutive size or anatomical
