99 



But if Galileo discovered the experimental method 

 as a method, before Galileo the method was in 

 use. Leonardo had laid down the rule of investi- 

 gation of nature by experiment, and the aphorism 

 that nature never deceives us ; unfortunately his 

 manuscripts were not published. In the first 

 half of the fifteenth century Nicl^las of Cusa 

 weighed plants at definite stages of their growth 

 in known weights of earth; and he weighed 

 the moisture of the air. His contemporary Leon 

 Battista Alberti of Genoa had done likewise. But 

 above all the scientific forerunners of Galileo and 

 Harvey stands William Gilbert, Fellow of St John's 

 College, Doctor of Medicine of Cambridge, Censor 

 and President of this College, Physician to Queen 

 Elizabeth, and Founder of the science of Magnetism. 

 The century dating from the birth of Galileo to 

 the death of Harvey was perhaps the most brilliant 

 in the history of modern knowledge. The discovery 

 of Greek texts had destroyed the conventional 

 Aristotle, the conventional Hippocrates and Galen ; 

 since the latter part of the sixteenth century Greek 



abolition we owe to Pasteur), yet Bacon (N. 0. IL 41) accepts 

 it, perhaps as fully as did Sir Thomas Browne. The De 

 generatione however was not actually published till 1651, 

 some 30 years after the Nonum Organon. 



72 



