226 DISCOVERY OH. 



more than a million people yearly in India alone. When 

 Sir Ronald Ross was carrying out at Bangalore the 

 intricate and minute researches required to determine 

 the cause of malaria and its remedy, he wrote the 

 pleading lines : 



In this, Nature, yield, I pray, to me. 



I pace and pace, and think and think, and take 

 The fever'd hands, and note down all I see, 



That some dim distant light may haply break. 



The painful faces ask, can we not cure ? 



We answer, No, not yet ; we seek the laws. 

 O God, reveal thro' all this thing obscure 



The unseen, small, but million-murdering cause. 



At that time it was believed by most people that 

 malaria was caused by some kind of vapour or " miasma " 

 which rose from swampy or marshy land. It is now 

 known to be transmitted by a certain kind of mos- 

 quito which can harbour the germs of the disease and 

 convey them from one person to another. 



This conclusion seems simple enough, but it was only 

 proved to be true by slow steps and persistent work. 

 The theory that mosquitoes are carriers of disease, and 

 that malaria is transmitted by them or flies, was put 

 forward fourteen centuries ago, and was revived in more 

 modern times, but systematic practical study was 

 necessary to establish it. The links of evidence by which 

 the mosquito has been convicted of causing many millions 

 of deaths from malaria were not forged together until 

 recent years. 



First, Dr. C. L. A. Laveran, a French army surgeon, 

 studying malaria in a military hospital in Algiers, dis- 

 covered that the blood of a person suffering from malaria 

 always contains a peculiar parasite or organism. Sir 

 Patrick Manson then suggested that these parasites pass 



