Carpenter's Principles of Physiology. 71 



ciples of inductive pliilosophy which have been and still are too 

 much neglected by physiologists. All classes of living beings are 

 regarded by him as of equal importance in a scientific view, as fur- 

 nishing instances, by the collection and comparison of which general 

 laws may be estabhshed. It is thus perceived that what is obscure 

 in one is frequently evident in another ; that the life of the simple 

 zoophyte may elucidate, if properly observed, the varied phaeno- 

 mena presented by man ; and that the functions of the humblest 

 plant may be traced as fundamentally the same, though gradually 

 becoming more complex, in the ascending scale of the animal as 

 well as of the vegetable creation. Such a work, we cannot but 

 hope, may contribute to excite and facilitate the study of physiology 

 amongst those who make science their pursuit. We need hardly 

 point out, that the connexion between these different branches of 

 knowledge is daily being rendered more intimate, especially by the 

 researches of the geologist and of the organic chemist ; the former 

 of whom requires to know those general laws Avhich govern the 

 conformation and distribution of organized beings, while the latter 

 seeks to elucidate the mysteries of vital action, by ascertaining the 

 extent to Avhich the physical properties of matter are concerned in 

 it. One of the most interesting examples of the value of such in- 

 quiries which has recently come under our notice, is the discovery 

 of M. Poisseuille, that viscid fluids may be propelled through ca- 

 pillary tubes M'ith much less effort than water or other liquids of 

 aqueous consistence ; and that a solution of gum, gelatin, albumen, 

 &c. Avill pass readily through tubes so small as to resist the passage 

 of water, whatever may be the degree of force employed. 



A brief account of the contents of this treatise will serve to dis- 

 play its scope and tendency. The author states himself to have 

 been led to its production by having " felt the want of a treatise 

 which should give a comprehensive view of the science, embracing 

 whatever general principles may be regarded as firmly established, 

 and illustrating them as fully as could be done within moderate 

 limits, yet without distracting the attention by profuseness of de- 

 tail." It commences with an introduction, which presents a ge- 

 neral account of the peculiarities of organized bodies, the elementary 

 structure of plants and animals, and an outline view of the chief 

 natural groups of these kingdoms, intended to facilitate the com- 

 prehension of the strictly physiological portion of the work. The 

 first book is devoted to general physiology ; and here we are con- 

 ducted through a profound but lucid investigation into the nature 

 and causes of vital actions, which we particularly recommend to 

 the attention of those who have been accustomed to refer to the 

 " vital principle " as an easy solvent for all difficulties. By com- 

 paring the phaenomena of vital action with those of the inorganic 

 world, the author shows that they are equally reducible to general 

 laws which result from ^the properties with which matter has been 

 endowed by the Creator. Of these properties some manifest them- 

 selves under the simple conditions which the ordinary changes in 

 the inorganic world supply, and thus perform the actions termed 



