186 ANALYTIC PHYSIOLOGY. 
rance why certain effects proceed immutably 
from certain causes; and any attempt to explain 
their relation, is a search of truth in the bound- 
less regions of possibility. 
By physical consequence only, do we acquire 
a knowledge of power; for example, the contact 
of one plate of copper and another of zine, gene- 
rates galvanic electricity ; but the operative power 
from which this phenomenon results, is unknown. 
There is nothing in bodies which, @ priori, indi- 
cates their properties; a knowledge of them is 
obtained only by experience. I would not, how- 
ever, indirectly insinuate that the properties of 
bodies are self-existing and inherent qualities ; 
their operations give us an idea of power, which 
is irresistibly attended with the idea of a govern- 
ing influence; for it is impossible to conceive 
foree without direction, unless we can at the same 
time form an idea of action without agency, and 
arrangement without intelligence. All the phe- 
nomena of nature are indicative of unlimited 
wisdom and power; hence it is to be presumed, 
that the properties of bodies must be derived 
from the Cause of nature, 
In the foregoing investigation of Physiological 
causation, I have uniformly traced Irritability 
and Decomposition to a power generated be- 
tween the blood and nervous system. This 
power, I am persuaded, is either Galvanic Elee- 
