78 A Century of Science 



time by the book of Horace Mann. This was dis- 

 couraging enough, but a third venture resulted in 

 a brilliant success. We have observed the eager- 

 ness with which, as a schoolboy, Mr. Youmans 

 entered upon the study of chemistry. His interest 

 in this science grew with years, and he devotecl 

 himself to it so far as was practicable. For a 

 blind man to carry on the study of a science which 

 is preeminently one of observation and experiment 

 might seem hopeless. It was at any rate abso- 

 lutely necessary to see with the eyes of others, if 

 not with his own. Here the assistance rendered 

 by his sister was invaluable. During most of this 

 period she served as amanuensis and reader for 

 him. But, more than this, she kept up for some 

 time a course of laboratory work, the results of 

 which were minutely described to her brother and 

 discussed with him in the evenings. The lectures 

 of Dr. John William Draper on chemistry were 

 also thoroughly discussed and pondered. 



The conditions under which Mr. Youmans worked 

 made it necessary for him to consider every point 

 with the extreme deliberation involved in framing 

 distinct mental images of things and processes 

 which he could not watch with the eye. It was 

 hard discipline, but he doubtless profited from it. 

 Nature had endowed him with an unusually clear 



