EXPERIMENTS IN LONDON 265 



their blood. Nine months later, one of them had 

 a relapse, and the parasite was again found in his 

 blood. 



It is not possible to sum up the wealth of work 

 on malaria published in 1 900-1 901. Good accounts 

 of it are in the Transactions of the Section of 

 Tropical Diseases, at the Annual Meeting of the 

 British Medical Association (Cheltenham, 1901), 

 and in the Thompson Yates Laboratories Reports, 

 vol. iii., pt. 2, 1 901. Everything had to be studied : 

 not only the nature and action of the Plasmodium in 

 all its phases, but also the whole natural history 

 and habits of the Anopheles of different countries ; 

 and, above all, the incidence of the disease on 

 natives and on Europeans in China, India, and 

 Africa. All that can be done here is to try to 

 indicate the principal lines followed in the present 

 world-wide campaign against malaria. The follow- 

 ing paragraphs are taken mostly from the accounts 

 given by Dr Christophers and Dr Annett, in the 

 Thompson Yates Laboratories Report, 1901 : — 



1. Elimination of the Infection at its Sotirce. 

 This is the method employed with success by 

 Professor Koch in New Guinea, viz., to search out 

 all cases of malaria (the concealed ones in particu- 

 lar), and to render them harmless by curing them 

 with quinine. At Stephansort, by thus hunting up 

 all infected cases, and as it were, sterilising them by 

 the systematic administration of quinine, he was 

 able to achieve a great reduction of the disease in 

 the next malarial season, even under adverse con- 

 ditions. He says, in his report to the German 



