ducted laboratory work in one of the rooms, which was fully 

 equipped for such a purpose, and led a busy and contented life. 

 They explored the neighboring swamps and woodlands, and 

 visited the neighboring villages. They received and entertained 

 many visitors who were interested in the experiment. They al- 

 ways turned indoors before sunset, and then stood at the win-, 

 dows and timed the first appearance of Anopheles, which would 

 come at a certain hour each evening and try to 1 enter the screened 

 windows and doors. * * * When the rains set in, everyone 

 said that that was the critical time of the experiment. The 

 people in the surrounding country became ill generally with 

 malaria, the chilling caused by the rain having brought about an 

 explosion of the fever. The experimenters, however, went out 

 into the rain and got soaked to the skin, but their health remained 

 perfect. Not the slightest trace of malaria developed in any of 

 them. As above stated, the spot where the house was built was 

 probably the most malarious one in the whole Campagna, and it 

 was situated on the banks of one of the canals, which literally 

 swarmed with Anopheles larvae. The prevalent idea that the 

 night air of the Campagna is in itself so dangerous was included 

 in the experiments, and the windows were always left open at 

 night, so that if the marsh air had anything to do with malaria, 

 they would have contracted it. 



"A check experiment was carried on at the same time. Ano- 

 pheles mosquitoes, which under the direction of the Italian 

 doctors Bignami and Bastianelli, had been fed on the blood of a 

 sufferer from malaria in Rome, were sent to London early in 

 July. A son of Sir Patrick Manson offered himself as a subject 

 for experiment and allowed himself to be bitten by the mosqui- 

 toes. He had never been in a malarious country since he was a 

 child, and was in perfect health, but in due time he was taken 

 with a well-marked malarial attack of the benign -tertian type; 

 microscopical examination showed the presence of the parasites 

 in his blood. Later a second subject, also an Englishman, who 

 had never suffered from malaria, submitted to the experiment, 

 allowing himself to be bitten by infected mosquitoes sent from 



