54 The Science of Life. 



Arabic", and by lecturing in German "sent a new thrill 

 through the untaught bosoms of the people". It was 

 probably from the East that Paracelsus derived his 

 doctrine of the Archaeus, the determining force of life, 

 the " spiritus rector" of the body, the "vital force" of 

 later days. It was an early expression of the fact which 

 still confronts us, that the organism has a secret ! 



Paracelsus did not achieve much, but to him, and to 

 his follower Van Helmont (1577-1644), who invented the 

 word gas, and suggested the theory of digestion by 

 ferments, was largely due the overthrow of the Aristo- 

 telian and Galenian traditions which had outlived their 

 usefulness. 



Thus Paracelsus gave a death-blow to the old patho- 

 logical doctrine of the four " humours". The revival of 

 the study of anatomy by men like Andreas Vesalius (of 

 Wesel), and Fabricius, whose names are perpetuated in 

 connection with various organs of man and animals, 

 was another factor in progress. Throughout the long 

 history, anatomy has again and again proved the sheet- 

 anchor which has kept physiology in safety. 



The doctrines of Aristotle and Galen valuable for 

 their age had gradually become an inhibiting dogma, 

 and the strength of tradition often broke the 

 young spirit of discovery. It is to Harvey 

 (1578-1657) that we must give the credit of inaugurating 

 a new epoch of observation and experiment. It was 

 not merely that he demonstrated the circulation of the 

 blood, and analysed out some of the dynamic factors in 

 the flow; it was his careful method of observing and 

 experimenting, instead of guessing and theorizing, that 

 gave him his high historical import. He comes into 

 line with Copernicus and Galileo, Bacon and Descartes, 

 and the other founders of the scientific method. 



The return to observation and experiment, which we 



associate with the name of Harvey, was rapidly rewarded 



by many discoveries. Some idea of the dig- 



comesof gy nity of the subject began to dawn in the 



* e as a minds of workers, and it soon became neces- 



Speciahsm. . 



sary to gather what was securely known into 

 a system better than that of Galen. This was achieved 



