54 MOSQUITOES 



lived in a malo.rions district ; a certain number, it ap- 

 peared, had not snffi^'ed from it in two or tliree years, 

 and all the others, that is to say, the larsfe majority, had 

 suffered frt)m it duriiiq- the last malarial season, some of 

 them even in tin? winttn*. Durini;- the malarial season, 

 the health of the protected individuals was s'ood, with the 

 exception of a few cases of bronchitis and a case of acute 

 gastroenteritis. None of these cases were treated with 

 quinine. The 104 i)ersons, Avith three exceptions, had re- 

 mained free from malaria up to Septend)er Kith, the date 

 of the report. 



Another vcny strihin.Gf exp(n'iment which during- the 

 autumn of li)00 was mentioned in newspa[)ers all over the 

 world, was that performed by Doctors Sambon and Tjow, 

 of the London School of Tropical IMedicine, in the Io- 

 nian Cam])a^-na, during- the late summer and early autumn 

 of 1900. They had constructed a comfortable little five- 

 roomed wooden house about three hours' drive from Ostia, 

 in one of the most malarious i)orti()ns of the Oampagna. 

 The house was tightly l)uilt and was thoroughly screcMUHl. 

 The experimenters lived in this house through tlie pciiod 

 Avhen malaria is most i)revalent. They took no (juiuiue 

 and no health precautions beyond the fact that at sun- 

 down each day they entered the house and remained there 

 until daylight the next morning. ])r Rees, of the London 

 School, visited them and occupied the house with tliem 

 for a portion of the time, and all three conducttul labora- 

 tory work in one of the rooms, which was fully equipped 

 for such a puri>ose, and led a l)usy and contented life. 

 They visited the neighboring villages and investigated 



