4 THE ROYAL SOCIETY OF CANADA 



body 1)0 apprehended, its disorders explained, and the appropriate 

 remedies applied. This interdependence of these various branches 

 of knowledge was realized by that wonderful genius of antiquity, 

 Aristotle, well called by Dante "The master of those who know," whose 

 words sound strangely modern in our ears, when he writes in the closing 

 sentences of his De Respirationc: — "But health and disease also claim 

 the attention of the scientist, and not merely of the physician, in so 

 far as an account of their causes is concerned. The extent to which 

 these two differ and investigate diverse provinces must not escape us, 

 since facts show that their inquiries are, to a certain extent, at least 

 conterminous. But physicians of culture and refinement make some 

 mention of natural science, and claim to derive their principles from it, 

 while the most accomplished investigators into nature generally push 

 their studies so far as to conclude with an account of medical principles." 



Though Aristotle, through the vastness of his range and the sheer 

 weight of intellect came to occupy the commanding position in the 

 world of thought and to exert an influence that has never ceased through 

 the ages, his- principles in r-egard to Medicine and Natural Science bore 

 no immediate fruit. For almost twenty centuries tradition was supreme. 

 Only with the advance of anatomy, physiology, chemistry, and physics 

 was progress in the healing art rendered possible. These subjects 

 form the foundation of modern scientific Medicine. Advance in them, 

 too, in turn depended on the discovery of improved methods of investi- 

 gation and the invention of scientific instruments ot power and precision. 



No single factor has been so efficacious in stimulating the research 

 spirit, and in building up Medicine on a scientific basis, as the invention 

 of the microscope. To it we owe the intimate knowledge of the structure 

 of animals and plants that we now possess. Malpighi was perhaps 

 the first physician to use it and he laid the foundation of microscopic 

 anatomy, or histology, which first rendered possible the accurate study 

 of the finer structural effects of disease. An observation of capital 

 importance was Malpighi's discovery of the capillary "circulation in 

 the lungs and bladder of the frog, on which was based the first rational 

 theory of the respiration. Intolerance in his time was evidently not 

 confined to the theologians, for certain of his colleagues at the uni- 

 ver-sity of Bologna held that his devotion to the microscope was deroga- 

 tory to his and their dignity and likely to bring the study of Medicine 

 into contempt. So high did the feeling run that, we ar-e informed, 

 Malpighi's br-other fought a duel with one of the opposing professors 

 who paid for his devotion to his principles with his life. Leeuwenhoek, 

 a contemporary of Malpighi, in a series of remarkable observations 

 contributed to the Royal Society of London during the decade from 

 1673 to 1683, created the science of microbiology. He was probably 



