621 



tural acids formed partly by hydrolysis of tannins and partly by 

 fermentation of the glucoses ever present in all tanning materials. 

 The chemistry of the hide is not fully understood and the exact 

 composition of many of the tannins is not yet established. Fin- 

 ally the newer science of colloidal chemistry urgently demands 

 consideration and application. 



XLVI. 



Land Sanitation. Repression of Malaria. Inquiries on some 

 diseases connected with agriculture. Measures for pro- 

 moting the health and physical welfare of the rural popu- 

 lation and favouring country-life. 



Malaria Investigations. (Report of the Advisory Committee for 

 the Tropical Diseases Research Fund for 1909. Printed by H. 

 M. Stationery Office, 1910. Cd. 4999. Pr. 2s. &/.). Reviewed 

 in Natunf, Vol. 83, April 2ist, 1910, p. 226. 



In it are to be found reports from all parts of the world in 

 which results of scientific investigations are communicated by those 

 engaged in studies bearing directly or indirectly upon tropical 

 diseases of all kinds. 



The first appendix contains reports on the measures taken for the 

 prevention of malarial fever. A Circular letter is given in the appendix, 

 despatched by the Colonial Secretary to the Colonial Governors. 



Replies are printed from Ceylon, Mauritius, East Africa, Nya- 

 saland, Somaliland, Uganda, Gambia, Gold Coast, Sierra Leone, 

 Northern and Southern Nigeria, South Africa, Bahamas, British 

 Guiana, British Honduras, Jamaica, Leeward Islands, Trinidad, 

 Windward Islands, Australia and Cyprus. 



In general the defence of dwellings and individuals against 

 mosquitoes, the destruction, so far as possible, of the breeding- 

 grounds of the mosquitoes, and the free distribution of quinine, 

 are the measures most commonly adopted. 



The Acting Governor of the Leeward Islands reports favour- 

 ably on the efficacy of the small fish known as "millions" (Girar- 

 dinus poeciloides] in keeping down mosquitoes. 



