1816.) Royal Society. +207 
mets (supposing them correct) show us that galvanism puts an end 
to this interruption. But it may do this merely by serving as a con- 
ductor to the nervous influence. 
On Thursday, the Ist of February, Dr. Wilson Philips’ paper was 
continued : he considers it as proved by his experiments that the 
ganglia comraunicate to the nerves proceeding from them the ge- 
neral influence of the brain and spinal marrow. Nerves proceeding 
from them supply all the involuntary muscles. But if this be the 
case, it will be asked, how comes the digestive power of the stomach 
to be destroyed by cutting the eighth pair of nerves, seeing that the 
stomach is supplied with nerves from ganglia? The eighth pair 
coming from the largest portion of the nervous matter possesses the 
greatest influence; but the digestive power of the stomach is 
weakened likewise by the interruption of the nerves proceeding from 
ganglia. This he proved by destroying part of the lower portion of 
the spinal marrow of different rabbits. In every case the digestive 
power of the stomach was impaired or destroyed ; the urinary blad- 
der and rectum lost the power of discharging their contents, and pa- 
ralysis of the lower extremities ensued, and a great degree of 
cold took place. The heat of one rabbit before death sunk as low 
as 75°, Though the power of the stomach as an organ of digestion 
is destroyed by cutting the eighth pair of nerves, still its muscular 
power remains; but it does not act as usual, because the stimulus of 
digested food is wanting ; or it acts so as to throw the food out of the 
stomach the wrong way, in consequence of the unnatural stimulus of 
undigested food. 
On Thursday, the Sth of February, Dr. Wilson Philips’ paper was 
concluded. He shewed that the heat of animals was in all probabi- 
lity owing to the nervous energy. He finished his paper with a ge- 
neral view of the facts which he had established in the three papers 
which he had laid before the Royal Society. ‘The muscular energy 
depends upon the particular structure of the muscles; the nervous 
system is supported by the sanguiferous; but the sanguiferous can 
act without the influence of the nervous system. Secretion and ani- 
mal heat are entirely dependent upon the nervous system. Hence 
the muscles cannot for any length of time continue to exert their 
energy if the nervous influence be cut off. ‘The nervous influence 
appears the same with the galvanic energy. 
At the same meeting a paper by Dr. Brewster, on the structure 
of the crystals of fluor spar and common salt was read. Haity had 
observed that all minerals whose primitive forms were symmetrical, as 
in the cube and tetrahedron, refract singly ; these figures belong to 
fluate of lime, common salt, alum, &c. Biot first attempted to give 
a reason for this curious circumstance. He observed that doubly 
refracting crystals act upon light two ways; some draw it nearer the 
axis, while others repel it to a greater distance : the first exert an at- 
traction; the second kind a repulsive force. ‘The crystal of fluor 
spar, &c. according to Biot, are intermediate between the other two, 
and therefore neither attract nor repel. Dr. Brewster found that 
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