322 PROGRESS OF SCIENCE IN THE CENTURY. 



and the search has been a fruitful one for physi- 

 ology. The analysis is entirely consistent with sci- 

 entific method and has been justified in its results. 

 But the history of the enquiry reveals a twofold 

 danger, (a) that the careless mistake a deeper de- 

 scription for an explanation, as if the cell and its 

 protoplasm did not imply a mysterious microcosm, 

 and (&) that in the analysis the unity of the organ- 

 ism be overlooked or slurred over as an unimportant 

 fact. 



But, it may be remarked, the physiologist has 

 surely done more than analyse the organism into its 

 component parts. Has he not summoned chemistry 

 and physics to his aid, and shown that many phe- 

 nomena which we call vital, which our predecessors 

 attributed to the action of a special vital force, may 

 be expressed in chemical and physical terms? Has 

 he not interpreted by diffusion and osmosis the ab- 

 sorption of food from the alimentary canal and the 

 interchange of gases which takes place in the lungs ? 

 Has he not given a physical account of the circula- 

 tion of the blood and the ascent of sap ? Has he not 

 found the source of animal heat in the chemical 

 changes which occur in the body-tissues, has he not 

 artificially manufactured from simple substances 

 various carbohydrates and the like, whose formation 

 was previously believed to be inseparably associated 

 with the controlling action of vital force ? And thus 

 we reach the position of those who say " that the 

 further physiology advances, the more does it become 

 possible to explain, on physical and chemical 

 grounds, phenomena which have hitherto been re- 

 garded as associated with a special vital force; that 

 it is only a question of time; that it will finally be 

 shown that the whole process of life is only a more 



