232 MY LIFE [Chap. 



altogether different studies, I never had occasion to use my 

 newly acquired knowledge, and soon forgot most of the 

 processes. But it gave me an interest in mathematics which 

 I have never lost ; and I rarely come across a mathematical 

 investigation without looking through it and trying to follow 

 the reasoning, though I soon get lost in the formulae. Still, 

 the ever-growing complexity of the higher mathematics 

 has a kind of fascination for me as exhibiting powers of the 

 human mind so very far above my own. 



There was in Leicester a very good town library, to which 

 I had access on paying a small subscription, and as I had 

 time for several hours' reading daily, I took full advantage of 

 it. Among the works I read here, which influenced my 

 future, were Humboldt's " Personal Narrative of Travels in 

 South America," which was, I think, the first book that gave 

 me a desire to visit the tropics. I also read here Prescott's 

 " History of the Conquests of Mexico and Peru," Robertson's 

 " History of Charles V. " and his " History of America," and 

 a number of other standard works. But perhaps the most 

 important book I read was Malthus's " Principles of Popula- 

 tion," which I greatly admired for its masterly summary of 

 facts and logical induction to conclusions. It was the first 

 work I had yet read treating of any of the problems of philo- 

 sophical biology, and its main principles remained with me 

 as a permanent possession, and twenty years later gave me 

 the long-sought clue to the effective agent in the evolution of 

 organic species. 



It was at Leicester that I was first introduced to a subject 

 which I had at that time never heard of, but which has played 

 an important part in my mental growth — psychical research, 

 as it is now termed. Some time in 1844 Mr. Spencer Hall 

 gave some lectures on mesmerism illustrated by experiments, 

 which I, as well as a few of the older boys, attended. I was 

 greatly interested and astonished at the phenomena exhibited, 

 in some cases with persons who volunteered from the audi- 

 ence ; and I was also impressed by the manner of the lecturer, 



