regulating the Vital and Physical Phenomena. S33 



extent the forces which control the latter contribute to the 

 action's going on in the former, there must be additional forces 

 resulting from the operation of properties, to which we know 

 nothing analogous elsewhere. The degree, however, in which 

 these superadded properties harmonize or interfere with those 

 common to other forms of matter, constitutes a fair and highly 

 interesting branch of inquiry ; and it is a question of a still 

 higher nature, whether the existence of vital properties is to be 

 regarded as the effect or the cause of the peculiar material con- 

 stitution of the tissues which exhibit them ? Each of these 

 questions we shall now examine in some detail. 



It would be useless to recapitulate the various opinions which have been 

 at dififerent times advanced regarding either of these subjects ; difi'erent 

 writers have espoused the opposite extremes, some maintaining that the ac- 

 tions performed by living beings are purely of a physical nature ; others, that 

 physical powers are not concerned in them ; and others have even presumed 

 upon the existence of a distinct intelligence, " Divinse particula aurae," pre- 

 siding over the affairs of each organism. The truth appears, with regard to 

 this, in common with so many disputed questions, to be in the mean between 

 the opposing extremes. 



22. The actions performed by living beings, the sum of 

 which constitutes their life, may be divided into three classes. 

 In the Jirst division may be included all those which are of a 

 purely physical character, depending solely upon the common 

 properties of matter, and performed by dead as well as by liv- 

 ing organized substances, as long as no obvious change has 

 taken place in their composition. The third division will com- 

 prehend all those changes which result strictly from the vital 

 properties of the living tissues, and which, therefore, entirely 

 cease at the moment of death. The second or intermediate 

 division includes all the changes in which physical laws may be 

 regarded as the immediate agents, but in which the conditions 

 of their operation are determined by the action of vital proper- 

 ties. It will, we think, be found that all the changes by which 

 the organism is immediately connected with the external world 

 (whether those changes are a part of the organic or animal 

 functions) belong to the Jlrst class ; that the actions concerned 

 in the conversion of the crude aliment, introduced from without 

 into organizable materials, which may serve as the pabulum of 

 the various tissues, are to be referred to the second class ; whilst 

 the act of organization^ and the endowment of the newly 



VOL. XXIV. NO. XLVXII.— APKIL 1838. Z 



