396
INFLUENCE OF ELECTRICITY.
result attended similar experiments by Legallois, Dupuy, Dr. Wilson
Philip, Clarke, Abel, and Hastings. YVhile, on the other hand,
Broughton, Magendie and Leuret, and Lassaigne state that digestion
appeared to them to be uninfluenced by the division of the nerve in
question. Mayer (Tiedemann’s Zeitschriften. 1,) also found that
the digestive process continued for a certain time, and that acid
chyme was formed—at all events in rabbits. * Bracket, (Recherches
sur les fonct. du Syst. Gangl. Paris, 1830,) too, states, that in all
his experiments the food underwent chymification at the parts where
it was in contact with the coats of the stomach.
The question cannot, however, be determined with complete cer¬
tainty in quadrupeds, on account of death taking place in them so
soon after the operation; I have therefore, in conjunction with Dr.
Dieckhof, instituted experiments on geese. After the birds had been
forty-eight hours without food, they were fed with oats. In each
experiment two birds were required. In one the vagus was divided
on both sides, while the other was left uninjured for the sake of com¬
parison. After the death of the first, which took place in the space
of five days, the second was killed. In the latter the crop was gene¬
rally empty; in the former it was always fully distended with oats,
and some grains were contained in the muscular gizzard, and these
were in part crushed. The fluid in the stomach was acid, but less
so than in the other uninjured animal. Hence we may conclude
that digestion is for the most part, but not entirely, checked by the
division of the nervi vagi. Tiedemann states, it is true, that after
both vagi had been divided in a dog, neither the matter vomited nor
the mucus secreted by the stomach was acid; and Mayer also relates
that in his experiments on cats and dogs the chyme formed after the
operation was not acid: yet he found the chyme acid in rabbits; and
in my experiments with Dr. Dieckhof I never found the acidity
absent, although it was less marked than in the sound animal. In
four of the dogs in which Dr. Reid had divided the vagi nerves in
the neck for the purpose of ascertaining the nature of the morbid
changes produced in the lungs, unequivocal proofs were afforded,
that, although lesion of the nervi vagi generally arrests digestion, yet
that process may occasionally go on perfectly well, even although
the cut ends of the nerves are kept far apart. One dog which lived
twelve days after the operation, was rapidly gaining flesh and
strength; and when he was killed, the lacteals and the thoracic duct
were found full of milky chyle. In two other dogs, food taken after
the operation was vomited in a half-digested state, and was found to
permanently redden litmus paper; and the lacteals were filled with
chyle in one of these dogs also, as well as in a fourth by which milk
that was given to it was vomited in a coagulated state.*
Dr. Wilson Philip has asserted that, after the experiment of di¬
viding the nervi vagi has been performed, the digestive action may
be restored by means of an electrical current transmitted through the
* Dr. J. Reid’s Experimental Investigation into the function of the eighth pair
of nerves. Edin. Med. and Surg. Journ. vol. 51, p. 310, et seq., and American
Edit., in volume form.