274 PERSONAL PREPARATION FOR RESEARCH. 



said that his greatest discovery was the finding of Scheele. 

 But Scheele disliked Bergmann at first, because he took 

 the credit of Scheele's discovery of oxalic acid, by publish- 

 ing it and omitting, by inadvertence, to mention Scheele's 

 name. Gahn, however, reconciled them, and they became 

 good friends. Faraday adopted the plan of employing an 

 obedient unskilled assistant, who had been a soldier, anc 

 the plan worked well. 



Many valuable researches have been made by a kind of 

 partnership method, the work being suitably divided, and 

 the results published in the joint names of the investi- 

 gators ; for instance, the isolation of boron, and the dis- 

 covery how to obtain potassium and sodium by distillation 

 of potash and soda with iron, were made by Gray-Lussac 

 and Thenard ; that of electrolytic transfer of the elements 

 of acids and salts to the respective poles of a voltaic bat- 

 tery, by Hisinger and Berzelius ; the decomposition of 

 water under the influence of a voltaic current, by Nicholson 

 and Carlisle ; that of platinum residues containing a new 

 metal, by Fourcroy and Vanquelin; and a very great 

 many more have been made by this method, as may be 

 easily seen by referring to the ' Catalogue of Scientific 

 Papers,' published by the Royal Society. 



The influence of age upon the ability to make re- 

 searches and discoveries does not appear very conspicuous ; 

 the power of research usually continues as long as the 

 senses and intellect remain unimpaired. Galileo was 

 born at Pisa in 1564, and made his first discovery, that 

 of the principle of the pendulum, before he was twenty 

 years old. He continued to make observations and dis- 

 coveries throughout nearly the whole of his life ; the latter 

 part of the time being, as is usual, the most devoted to 

 reflection, writing, systematising his knowledge, and 



