24 Annwersary Address by Sir William Huggins. [Nov. 30, 
the causation of a number of important diseases affecting man and animals. 
When he went to Malta in 1884 the exact nature of the widely-prevalent 
“ Malta,” “Rock,” or “Mediterranean” Fever was entirely unknown. After 
some years work at the etiology of this disease, he discovered in 1887 the 
organism causing it, and succeeded in cultivating the Micrococcus melitensis 
outside the body. ‘This discovery has been confirmed by many other workers, 
and is one of great importance from all points of view, and perhaps more 
especially as, thanks to it, Malta Fever can now be separated from other 
diseases, ¢.g., typhoid, remittent, and malarious fevers, with which it had | 
hitherto been confounded. 
During the next few years he was engaged in researches of value on 
Cholera, and on methods of immunisation against this disease. He also 
carried out some Work on the Leucocytes in the Blood, published in the 
“ Proceedings of the Royal Society,” 1894. 
In 1894 he was requested by the Governor of Natal to investigate the 
supposed distinct diseases of “Nagana” and the Tsetse Fly disease. In the 
short time of two months he made the most important discovery that these 
two diseases were one and the same, and dependent upon the presence of a 
protozoan organism in the blood known asa Trypanosoma. Some six months 
later Bruce was enabled to return to Zululand, and remained there two years, 
studying the disease and making the discovery that the Tsetse Fly acted 
as the carrier of the organism which caused it. He was thus the first to show 
that an insect might carry a protozoan parasite that was pathogenic. This 
observation was made in 1895. 
Bruce not only determined the nature and course of “ Nagana,’ but in 
addition he studied the disease in a large number of domestic animals, and 
also observed the malady in a latent form in the wild animals of South 
Africa. Subsequent observers have found but little to add to Bruce’s work 
on this subject. 
In 1900, Bruce was ordered to join a Commission investigating the outbreak 
of Dysentery in the Army in South Africa, and a great part of the laboratory 
work performed by this Commission was carried out by him. 
In 1903, Col. Bruce went, at the request of the Royal Society, to Uganda, 
to investigate further the nature of Sleeping Sickness. It was very largely, 
if not entirely, owing to him that the work of the Royal Society’s Commission 
was brought to a successful issue. At the time when he arrived, a 
Trypanosoma had been observed by Castellani in a small number of cases of 
this disease; thanks to Bruce’s energy and: scientific insight, these observations 
were rapidly extended, and the most conclusive evidence obtained, that in all 
