18 Anmversary Address by Sir William Huggins. [Nov. 30, 
of very great practical importance, has been carried on by a series of Com- 
mittees successively appointed at the request of the Government for the con- 
sideration of some of the strangely mysterious and deadly diseases of tropical 
countries. In 1896 a Committee was appointed at the request of the Colonial 
Secretary to investigate the subject of the Tsetse Fly disease in South Africa. 
Two years later Mr. Chamberlain, Secretary of State for the Colonies, requested 
the Society to appoint a Committee to make a thorough investigation into the 
origin, the transmission, and the possible preventives and remedies of tropical 
diseases, and especially of the malarial and “ Blackwater” fevers prevalent in 
Africa, promising assistance, both on the part of the Colonial Office and of 
the Colonies concerned. A Committee was appointed, and, under its auspices, 
skilled investigators were sent out to Africa and to India. In the case of 
the third Committee the Society itself took the initiative. An outbreak in 
Uganda of the disease, appalling in its inexorable deadliness, known as 
“Sleeping Sickness ” having been brought to the knowledge of the Society, a 
deputation waited upon Lord Lansdowne at the Foreign Office, asking him to: 
consider favourably the despatch of a small Commission to Uganda to 
investigate the disease. He gave his approval, and a Commission of three 
experts, appointed on the recommendation of the Committee, was sent out 
to Uganda, £600 being voted out of the Government Grant towards the 
expenses of the Commission. 
The investigations in tropical diseases, promoted and directed by these 
Committees, have largely increased our knowledge of the true nature of these 
diseases, and, what is of the highest practical importance, they have shown 
that their propagation depends upon conditions which it is in the power of 
man so far to modify, or guard against, as to afford a reasonable expectation 
that it may be possible for Europeans to live and carry on their work in parts 
of the earth where hitherto the sacrifice of health, and even of life, has been 
fearfully great. A general summary of the work already done on Malaria, 
especially in regard to its prevention, and also on the nature of “ Blackwater ” 
Fever, has been published in a Parliamentary paper, which records Mr. 
Chamberlain’s acknowledgment to the Royal Society for its co-operation in 
the work undertaken by the Colonial Office. Our Reports on Sleeping 
Sickness up to this time form four parts of a separate publication giving 
evidence in support of the view that this deadly disease is caused by the 
entrance into the blood, and thence into the cerebro-spinal fluid, of a species. 
of Trypanosoma, and that these organisms are transmitted from the sick to 
the healthy by a kind of tsetse fly, and by it alone; Sleeping Sickness is in 
short a human tsetse fly disease. 
