52 
J. MYERS, Jr. 
open by manipulating a screw at the flange allowing the gas to escape 
through the receptacle and out of the canula; the object of the bivalve 
is to support the intestinal walls so that they cannot recede whilst the 
gas is escaping, which would otherwise be apt to displace the canula. 
As judicious as this construction seems to be, it has certain disadvan¬ 
tages, the point being retained within the bowel, and by virtue of its 
(the bowel) collapsing the opposite wall is in danger of being injured. 
The small openings for the valves are apt to become obstructed by 
particles of food which prevent their closure, consequently rendering 
it exceedingly difficult to remove the instrument without causing more 
or less damages. The inventor of this instrument ascribed to it an 
electric property generated by the contact of the different metals it is 
made of, with the acid contents of the bowels, which electric force, he 
in 1849 declared to be of minor importance. Hayne’s trocar is from 
8 to 10 inches long, and from 1^ to 2 lines thick; in my estimation a 
most appropriate instrument. 
Gaube reported in 1849 a case upon which he operated with bistoury 
and quill. The introduction of therapeutics through the canula has 
also been advocated. Delwart in 1846 reported an instance where he 
introduced oz. xii. tincture of aloes into the bowel through the canula 
with good results “Cathartic.” Brogniez is another supporter of this 
practice, but more recent practitioners do not regard it as essential. 
Lafosse during his experiments upon different cases retained the instru¬ 
ment from 6 to 30 hours, which proved unnecessary for all the movable 
gas will find its exit from 3 to 8 minutes, and its retention by the per¬ 
sistent irritation is very liable to produce inflammation, adhesions, and 
abscesses. 
Schaak in 1839 reports a case where a scrotal abscess super¬ 
vened, which complication is by no means very uncommon. 
Cartier in 1849 cites a case where it was an impossibility to close the 
valves of the trocar necessitating a forcible removal which produced 
an abscess of three weeks duration. Numerous other cases of abscesses 
have been reported principally from French sources with comparative 
good results. 
I abstracted these chronicled items chiefly from the sur¬ 
gical work (Operations lelire) edited by the eminent author and 
pioneer of veterinary science, Prof. Ed. V. Ilering whose technical 
rules I took as a guide in performing the operation in general, deviat¬ 
ing from them only in minor matters. Moreover as far as I could 
