PROGRESS OF VETERINARY SCIENCE AND ART. 285 
the outer side of the tunic, and it is cautiously sought to 
pass the instrument beyond the strangulated part; the blades 
are then pressed open, and the cut made in retracting the 
instrument. The cut is made towards the outer side, be- 
cause here lies the cremaster, and a wound of the inguinal 
canal, which might be associated with bleeding, is thereby 
avoided. The return of the portion of intestine is effected in 
part by slight retraction and then manipulations pressing it 
inwards. The clams are thereupon applied as high as pos- 
sible over the vaginal tunic, and are left there for two or 
three days. The horse is not let loose directly ; and to guard 
against peritonitis he is bled, and mustard is applied over the 
abdomen. 
Bouley’s herniotomy knife is in the form of closed scissors, 
and has a concealed blade which can be pressed out by a 
screw during the operation. From the repeated observation 
of such cases as seen at Alfort, the conclusion has been 
arrived at that the incarceration of the intestine does not 
occur in the inguinal canal itself, but that the tunica vaginalis 
at its lower part forms transverse folds, inducing compres- 
sion and constriction of the gut. 
1 need scarcely say that the sinapisms and bleedings were 
out of place, and that it is advisable to keep the clams on 
longer than Stokfleth tells us is done at Alfort. In Lyons 
the clams are allowed to drop off with the testicle, which is 
often not cut away at the time of the operation. The explana- 
tion of the constriction of the gut in the inguinal canal is 
interesting, but does not deserve unqualified acceptation. 
Nor, indeed, do I think it is the right construction to be 
admitted, except in an exceptional case, for we know that 
strangulation of a gut protruding through a natural or an 
artificial opening occurs in two ways. 1st, If the hernia be 
of old standing, a fresh portion of intestine or omentum slip- 
ping through, in consequence of some accidental circum- 
stance, distends the hernia, and compression, hence strangu- 
lation, occurs at the neck of the sac. 2dly, In young animals, 
during violent action or sudden effort, a piece of gut sl^ps 
through an opening not sufficiently large to admit of it, 
except from over distension and pressure. The opening does 
not readily adapt itself to its new contents, and rapid stran- 
gulation is the result. 
One point may be referred to which regards the per- 
formance of the covered operation for castration. The skin 
of the scrotum is carefully dissected from the tunica albu- 
ginea, and from the cellular tissue being loose, the process is 
not altogether an agreeable one, the parts being apt to slip 
xxix. 37 
