Sir John Simon. 341 



I now propose to supplement the short sketch contained in the 

 preceding paragraphs by such more detailed information as will be of 

 service to the reader in forming an estimate of Mr. Simon's attain- 

 ments as a biologist, as a pathologist, and as the adviser of Government 

 in matters relating to public health. 



Of Simon's two researches in comparative anatomy, one, on the 

 " Comparative Anatomy of the Thyroid Gland,"* was contributed to the 

 Royal Society in 1844. To the other, on the structure, development, 

 morphology, comparative anatomy, and physiology of the thymus 

 gland, the Astley-Cooperf prize was awarded the same year. The 

 exactitude of his observations, many of which were at that time new, 

 his reluctance to take anything for granted that he had not confirmed 

 by his own observation, the care he bestowed on the many hundred 

 original dissections and microscopical preparations he made, all serve to 

 show that comparative anatomy was the loser for his not choosing it 

 as the branch of science he was to follow. Until he took up the study 

 of the two organs, there had been a great deal of confusion in the 

 discussion of their morphology in the lower vertebrates. In some 

 orders of mammals, in birds, and in some reptiles and amphibians, 

 Simon was the first to describe, or to distinguish, the Thymus. He 

 further established an inverse proportion between its persistence in an 

 animal or group of animals, and the muscular activity of that animal, 

 and concluded therefrom, and also from his failure to recognise it in the 

 gill-breathing vertebrates, that the chief function of the thymus 

 consists in its supplying fuel for respiration during its period of activity. 



The Thyroid he described for the first time in fish and in certain 

 reptiles, and showed that while its position varies in the different 

 genera of fish in which it is present, its relation to the vascular supply 

 of the brain is the same, and resembles that which prevails in the 

 higher vertebrates. 



As we have seen, Simon first obtained the approval of the Royal 

 Society as a biologist. But it was as the first English systematic 

 writer on Pathology, i.e., on the science which deals with the causes and 

 nature of disease, that he first became known to students of medicine. 

 The lectures at St. Thomas' Hospital} appeared in 1850. The founda- 

 tion of the new science had been laid by Henle, and Virchow was 

 attracting to Wurzburg such English students as desired to learn the 

 new methods of pathological research. The fact that Simon was the 

 English exponent of the rapid progress of discovery in Germany gave 

 the lectures a special interest ; for, at that time, the notion that the 

 functions of the living organism could be best understood by bringing 

 them into relation to the processes of non-living nature, and best 



* " Phil. Trans.," vol. 134. f " Physiological Essay on the Thymus Gland." 

 " Greneral Pathology," published by Henry Kenshaw, 1850. 



