PREFACE. 



a time of life long subsequent to that at which most men seek repose from 

 such labour, he was as fresh, clear, full, and impressive, in teaching ana- 

 tomy, at once the most elementary and the most important of the studies 

 accessory to medicine, as in his early days. 



The celebrated discoverer of Endosmose, H. DUTROCIIET, lived to the 

 ripe age of seventy-one. The article on that subject in this work was the 

 contribution of his own pen. It contains a summary of his views up to the 

 time of its publication. Dutrochet's discovery has the most interesting and 

 important bearing upon the application of physical laws to the illustration of 

 various processes of living organisms. It gave the clue to the elucidation of 

 many obscure points in the physiology of animals and plants, and took a lead 

 in directing the minds of Physiologists away from abstract and fruitless 

 speculations concerning the nature of Life, into the true path of inquiry as to 

 the dependence of vital phenomena on chemical and physical laws. 



The value of this discovery is enhanced by the recent researches of 

 Mr. GRAHAM, which have developed the laws of Osmose (to use his more 

 concise and comprehensive designation), and have shown the intimate con- 

 nexion of osmotic with chemical action. Further experiments on the osmotic 

 phenomena of living animals and plants, assisted by the additional light ob- 

 tained from Mr. Graham's researches, can scarcely fail to lead to important, 

 practical results, both in Physiology and Pathology. 



The loss of NEWPORT was a heavy blow to Physiology. A man of his 

 skill as a dissector and observer of that large and most interesting tribe, the 

 Insects, could ill be spared. The combination of such manual dexterity and 

 of so much acuteness of observation as Newport displayed is rarely met with. 

 His investigations embraced at once the most delicate anatomical analyses and 

 the deepest questions of physiology. The article INSECTA, contributed by 

 him to this work, is perhaps the most comprehensive account extant of the 

 anatomy and physiology of this class of invertebrate animals. Newport was 

 cut down in the prime of life, when, after many struggles and difficulties 

 his merits were becoming recognised, and the value of his researches appre- 

 ciated. There can be no doubt, had health and life been given him, he would 

 have largely extended our knowledge of this branch of Comparative Anatomy 

 and Physiology. 



