General Principles of Physiology. 105 
We have seen that by dividing the eighth pair of nerves in the 
neck, and displacing the divided ends, the power of digestion, 
and consequently the secretion of gastric fluid, is destroyed, and 
the function of the lungs deranged. This appeared to offer an 
excellent opportunity of ascertaining how far galvanism is capa- 
ble of some of the more complicated functions of the nervous 
power. It is not difficult, by coating the lower part of the di- 
vided nerves with tin foil, and applying a small plate of metal 
to the skin over the stomach and lungs, to expose these organs 
by means of a voltaic pile to any degree of galvanic power which 
may be judged proper. 
This was done both in granivorous and carnivorous animals *, 
and in both the functions of the stomach and lungs were restored 
by the presence of the galvanic influence. We cannot distinguish 
the effect in either instance from the healthy function. 
It appears, from what was said above, that the division of the 
nerves not only deranges the secreting power of the lungs, but 
from their peculiar texture occasions, in the space of a few hours, 
evident deviations from their healthy structure. If, however, 
the application of the galvanism be made as soon as the division 
of the nerves takes place, and maintained with sufficient force, 
but not so long nor with such force as to excite inflammation, 
the structure as well as the function of the lungs continues un- 
impaired ; thus proving that galvanism may be substituted for the 
influence of the nervous system inall the processes of assimilation. 
The functions of this system we have seen are,to excite the 
muscles, to convey impressions to and from the sensorium, to 
effect the formation of the secreted fluids, and other processes of 
assimilation, and to maintain the temperature of the animal 
body. Galvanism has long been admitted to be the best of all 
artificial stimuli of the muscles, and capable, in either direction, 
of passing along the nerves; and, it may be observed, better 
adapted to the excitement of the muscles when the positive than 
when the negative end of the pile is connected with the brain. 
The experiments just referred to prove it to be capable of effect- 
* Expr. Ing. Exp. 70,71, 72, 73: Philosophical Transuctions for the pre- 
sent year. Journal of the Royal Institut. No. 22, 23. 
