146 Organic Physics. [Febi | 
by its oxidation to invigorate the nerve currents. Yet inal | 
probability its purpose is the exact opposite of this; it acts t f 
resist instead of to invigorate the current. The physiologyo f 
-the nerve system yields evidences of this. One function of the | 
brain cells is, perhaps, to resist the currents over the nerves, 
prevent all sensory currents from producing reflex motions. 
another portion of the nervous system—the sympathetic—ga 
are interposed in great numbers. There is reason to believe that 
they act to hinder the outflow of nerve currents. A slight acti 
upon a sympathetic nerve fiber causes motion only in adja 
muscles. A more powerful action causes a wider series of mo 
brain when the impulse is so energetic as to indicate dangef 
the economy. When thus called upon the mind is able to directly 
respond, through the cerebro-spinal fibers, of probably m 
function, which accompany the sympathetic. 
The anatomy of the nerve cell yields confirmation of this. 
It presents, indeed, a singular analogy to the expedient adopt 
in telegraphy for the same purpose. It is a “ resistance coil” i 
terposed in the nerve circuit. For the recent delicate m 
Scopic investigation of the nerve cell has demonstrated that 
really a congeries of excessively fine fibrils. These pene 
every portion of the cell and its nucleus, and are continued 
ward by delicate rootlets, or by fibers. The rootlets probab 
form a network termination to the sensory nerves, and the fib 
are the origin of the motor nerves. 
As the fine wires in the resistance coil of the electric c 
rent check the flow, and permit the operator to control 
quantity of electricity passing, or to completely prevent its Pê 
sage, so may the cell fibrils interposed in the line of the cond 
ing nerve, perform a like duty. Possibly, to a certain exte 
result is the same. The checked current of energy becomes © 
verted into heat. But in one of the ganglia, the brain, it becom 
consciousness, or mental energy, a process with which we ® 
not here concerned. In regard to the apparent differen 
gangliar termination in sensory and motor nerves, the netW9 
inat 
i 
