44 



motion as different things ; and motion as a super- 

 added quality. In denying the older opinion 1 that 

 the heart is the source of motion, of perfection 2 

 and of heat, he put the difficulty but one stage back ; 

 and, when in the treatise on Generation he pro- 

 pounded his transcendental notion of the impreg- 



and Virchow ; it would ill become me to depreciate a distin- 

 guished Fellow of my own College, and as a clinical observer 

 Glisson had considerable merits ; but as a physiologist he was 

 sunk in realism. He was happy in the invention of the 

 technical term "irritability," but for him this virtue was 

 as metaphysical an essence as the vital spirit; his prime 

 motor was not physical. As a philosopher I fear the inde- 

 pendent reader of his works will find him fanciful and 

 wearisome. 



1 Herein Harvey's sagacity brought him towards the truth. 

 "Air," he says in the De generatione, "is given neither for 



the cooling nor the nutrition of animals it is as if heat 



were rather enkindled within the foetus (at birth) than re- 

 pressed by the influence of the air." Boyle (who says that he 

 worked under the influence of Harvey's discoveries) carried 

 this matter forward by most interesting and sagacious experi- 

 ments with his air-pump. For the layman, I may add that (to 

 speak generally) before Harvey's time respiration was regarded 

 not as a means of combustion but of refrigeration. How man 

 became such a fiery dragon was the puzzle ! 



2 Perfection was attributed, not only by medieval philo- 

 sophers but also by Plato and Aristotle, to the circle. Cir- 

 cular movement was therefore the most perfect, and therefore 

 again must be that of the planets. This is a good illustration 

 of the almost necessary tendency in the earlier excursions 

 of thought to equate incoordinates, and to fill gaps in reason- 

 ing from alien sources. 



