DR. PHILIP ON THE POWERS OF LIFE. 
359 
with those of any of the powers of inanimate nature, or can this influence exist in 
any texture but that to which it belongs in the living animal ? 
It is enough to say that its only property is that, by which it is enabled to co- 
operate with the immediate organs of the sensorial power. To such a property we 
not only find that there is nothing analogous in any of the properties of inanimate 
nature ; but, as will more fully appear from what I am about to say, that the organs 
of the sensorial power are, in their healthy functions, unapproachable by any of its 
agents : it is therefore perhaps unnecessary to add, that we know of no texture in 
which the influence conveyed by the nerves of sensation can be supposed to exist, 
but that to which it belongs in the living animal. 
The nerves of sensation therefore belong to the sensorial not to the nervous power. 
They convey an influence of a wholly different nature from that conveyed by the nerves 
of the latter power ; and the only analogy which can be traced between their function 
and the operations of inanimate nature is, that it is excited by impressions received 
from the agents of the external world ; to which we are indebted for all our know- 
ledge of that world. The action of the immediate organs of the sensorial power, we 
have seen, being thus excited by one vital part acting on another, and by its vital pro- 
perties alone, all analogy with the operations of inanimate nature here disappears. 
While the other functions of the living animal are the results of inanimate agents 
acting on living parts or living parts on them, in the sensorial functions we see the 
effects of vital parts acting on each other and that by their vital properties alone. 
Hence the analogy between the former and the operations of inanimate nature, and, 
with the exception just pointed out, the total loss of all such analogy in the latter. 
Whence is it possible to conceive that such analogy can arise except from the 
operation of some of the agents of the inanimate world? When the phenomena of the 
living animal are carefully compared with the preceding facts, it will be found that 
in every instance, in which any analogy between its functions and the operations of 
inanimate nature can be traced, the interference of such an agent may be detected. 
WE have now considered individually the various powers of the more perfect living 
animal. We have found in it, beside the mechanical powers which, it will be ad- 
mitted on all hands, it evidently possesses in common with inanimate nature, four 
distinct powers ; three of them vital powers, properly so called, that is, powers having 
properties essentially different from those of the agents which operate in inanimate 
nature. In the fourth alone we recognise one of those agents ; for we find it can exist 
in other textures than those to which it belongs in the living animal, and that we can 
substitute for it one of the powers of inanimate nature without deranging the func- 
tions of life. 
All these powers are employed, although in a very different way, in the construction 
of two systems in a great degree distinct ; the end of the one being the maintenance 
of our bodies, of the other, our intercourse with the world which surrounds us. 
