CHEMICAL PHENOMENA IN LIFE 



cline to the highest admiration for the genius 

 who first applied chemical and physical methods 

 to Biology. Stephen Hales' Statical Essays 

 (1727) are the memorial of the entrance of 

 Physiology into the ranks of the Exact Sciences. 

 These Essays contain the first application of 

 physical laws to biological problems. The pressure 

 of blood in the arteries and the pressure of sap 

 in the vessels of plants were henceforth facts ex- 

 pressed in exact mathematical values. In studying 

 Hales' Statical Essays we may most strikingly feel 

 the splendid progress in Biology which lies in the 

 application to the ever-changing living organism 

 of methods hitherto only applied to inanimate 

 matter. Experimental Biology entirely abstracts 

 from the qualities which to the naive eye of the 

 observer are characteristics of life. It enters the 

 territory of its investigation from the highest 

 philosophical point of view, that of the probable 

 connection of living and non-living matter. 



Thus was built the bridge between Exact Science 

 and Biology. At present we may consider Ex- 

 perimental Biology an Exact Science as well as 

 Physics and Chemistry. All employ the same 

 methods, and their end is the same, viz. to lead 

 by means of mathematical conclusions to general 

 results which enable us to explain a greater complex 

 of facts starting from a limited number of experi- 

 mental results. I would prefer to speak of Ex- 

 perimental Biology rather than of Physiology, as is 



