336 Mr Carpenter on the Difference^ of the Laws 



under those peculiar conditions which a living organism alone 

 <;an supply. In so far as the skill of the chemist can imitate 

 those conditions, he may hope to produce similar combinations, 

 and this has to a certain extent been already effected ; but even 

 those who believe that the existence of vital properties is the 

 result of the organization of the tissue which manifests them, 

 must despair of themselves effecting that process, which seems 

 to be entirely dependent on the previous existence of some 

 other organizing body. The three great steps in the function 

 of assimilation {first, the absorption of aliment ; second, its 

 conversion into organizable materials or proximate principles ; 

 third, its organization and vitalization) present us with illustra- 

 tions of the three classes of actions which we assumed as ex- 

 pressive of the mode in which the changes constituting life 

 may be most simply and philosophically distributed. But the 

 opinion here given with regard to the formation of organic 

 compounds, which we have referred to the action of chemical 

 affinity (believing the peculiarity of the results to be due to the 

 mode in which the elements are presented to each other, rather 

 than to any thing essentially different in the bond of union), is 

 opposed to that of many eminent physiologists of the present 

 day ; and as it may be regarded as one of the most important 

 questions in physiology, and one which the weight of the facts 

 and arguments on either side renders peculiarly open to discus- 

 sion, we shall devote some space to the consideration of it. 



26. The question may be advantageously stated in its broad- 

 est form, — " Are the affinities which hold together the elements 

 of living bodies, and govern the elaboration of organic pro- 

 ducts, similar to, or distinct from, those which preside over in- 

 organic compounds .P" On this question we find the greatest 

 number of modern physiologists opposed in belief to the che- 

 mists of the present day ; the former maintaining the existence 

 of a distinct set of vital ajinities, sometimes, and indeed gene- 

 rally, opposing the usual action of chemical laws ; the latter 

 believing, that, however at first sight the actions of vital che- 

 mistry may appear inexplicable by the known laws of affinity, 

 they are to be ultimately explained on the same general prin- 

 ciples. The physiologist points to the evident truth, that the 

 tissues and fluids which maintain a certain composition whilst 



