278 Dr Alison on the VHnciple of Vital Affinity . 



proper tissue of all plants which have been previously exposed 

 to the influence of these solvents, leaves a substance which is 

 identical in all of them, a substance which contains carbon and 

 the elements of water." — {Chemistry of Vegetable and Animal 

 Physiology, pp. 188-195.) 



Mulder annexes to this statement a speculation in regard 

 tO" the influence o^ forms in organized bodies, as affecting their 

 chemical powers or properties, which, so far as I can under- 

 stand ity I think fitted to convey an erroneous impression. 



" One of the first and chief laws visible in organic nature 

 is that the form has as much influence on the character of the 

 phenomena as the substance of which that form consists. The 

 eff'ects of the primary forces existing in the molecules, have 

 become, by the combination of elements into hollow globules, 

 altogether peculiar.'' 



*' In organic nature, besides all the peculiarities existing in 

 the carbon, hydrogen, and oxygen, we must suppose, as a chief 

 consequence of this, a tendency to form membranaceous, con- 

 cave, spherical little bodies, in which, because of this form, new 

 peculiar properties manifest themselves, which cannot be 

 brought out by other forms. Thus, by matter and form, all 

 that we observe in nature is, to a great extent determined."^ 

 — {Ibid., p. 189.) If by this it is meant that the acquisition 

 of the form is the physical cause of the existence of the pro- 

 perties which cells, or any other organized structures present 

 in the living state, two questions immediately present them- 

 selves, ^r*/. How are the cells themselves formed {e.g. on the 

 germinal membrane of the ovum) out of a matter which is 

 originally without form, otherwise than by those very pro- 

 perties which are here ascribed to their existence ? and, se- 

 condly. If the properties are dependent only on forms, why do 

 they not exist in the dead state, when the forms are, in many 

 instances, still perfect \ The enunciation of these questions 

 seems to me sufficient to shew, that the correct expression of 

 the state of our knowledge on this point is that already quoted 

 from Liebig, that the chemical forces in living bodies are sub- 

 ject, not simply to an influence of forms, but to " the invisible 

 cause by which the forms of organs are produced,'"' i. e., that we 

 must include under the head of vital properties, both the me- 



