62 INTRODUCTION TO SCIENCE 



house, and looking at the sun, and wondering. It 

 was said of Edward Forbes, one of the most 

 brilliant of British naturalists, that "he had a 

 hawk's eye to see in a moment any plant that was 

 new." And it is our impression, based on the 

 history of science, that apart from genius most 

 discoveries have been psychologically due to a 

 combination of the keen eye with the inquisitive 

 spirit. Let us recall what Tyndall has told us of 

 the way in which Robert Mayer was led to his 

 theory of energy. 



"In the summer of 1840, as he himself informs 

 us, he was at Java, and there observed that the 

 venous bfood of some of his patients had a singu- 

 larly bright red colour. The observation riveted 

 his attention; he reasoned upon it, and came to 

 the conclusion that the brightness of the colour 

 was due to the fact that a less amount of oxida- 

 tion sufficed to keep up the temperature of the 

 body in a hot climate than in a cold one. The 

 darkness of the venous blood he regarded as the 

 visible sign of the energy of oxidation" (Tyndall, 

 1876, p. 274). 



He was drawn to the whole question of animal 

 heat, to the relation between heat generated and 

 work done, and to his remarkable contributions 

 to the mechanical theory of heat in particular, 

 and to the theory of energy in general. All roads 

 lead to Rome, and he must be a bold man who 



