xiv THE DARWIN CENTENARY. [April 23, 



who saw everything that there was to see, whose eyes seemed to 

 pierce beneath the surface of things. Acute observation and patient 

 reflection were both written in it. One felt that hardly any problem 

 would be too difficult to be solved by the steadiness and persistence 

 of his thought. 



As often happens, one cannot after the lapse of years remember 

 much of the conversation that passed, and only a few things that 

 Mr. Darwin said rise to my mind now. The subject of malaria and 

 malarial diseases happened to be mentioned and their prevalence 

 over large parts of the world. It was before the time of the dis- 

 covery of the malaria-bearing mosquito, and he observed that if 

 any one could discover a method of inoculation which would make 

 men immune against malaria, that that would be one of the greatest 

 discoveries of the world. He thought at that time that if this dis- 

 covery came about it would be of supreme significance for commer- 

 cial and political affairs by making possible the development by 

 white men of large parts of the earth's surface, such as tropical 

 Africa. He added it was a mistake to suppose that malaria was 

 confined to marshy districts. In the Cape Verde Islands, which he 

 had visited, when a heavy shower falls malaria appears within a 

 day or two afterwards. The Cape Verde Islands are, he said, of 

 dry volcanic rock, and yet in spots on them where there were no 

 marsh at all heavy rains falling upon this volcanic rock would be 

 quickly followed by an outbreak of malarial fever. Of course, we 

 know now how to explain that, but he had been struck by the fact 

 before others had discovered the part played by the mosquito. 



The impression which his whole demeanour and conversation 

 made was that of perfect candour and naturalness. There was noth- 

 ing of what people call " self-consciousness." 



Darwin left on every one who knew him the impression of a 

 philosopher in that old sense of the word which makes it denote 

 not only the love of wisdom and truth but the tranquility of mind, 

 the calmness and peace, which devotion to truth brings. In him 

 wisdom and the search for truth appeared to have had their perfect 

 work, in forming a character, so beautiful in its earnestness, its 

 modesty, its simplicity, its sweet serenity. 



