504 MR. yotjatt’s veterinary lectures. 
The twitch is then firmly placed on the muzzle, and the head 
elevated—the operator, if necessary, standing on a stool or pail, 
that he may more perfectly command the part. A scalpel, scis¬ 
sors, bistoury, curved needles armed, and a moist sponge, should 
be held by an assistant. 
The hair is first to be closely cut from the part; usually be¬ 
tween the fifth and sixth lino;. The integument is then to be 
tightened across the trachea with the thumb and fingers of the 
left hand, and an incision cautiously made through the skin, 
three inches in length ; the operator being prepared to raise the 
knife at the least motion of the patient. The subcutaneous 
tissue will thus be brought into view. 
The operator must have previously determined what kind of 
incision he will make into the windpipe. It has been usual to 
cut out a small slip in the centre, half an inch wide, and includ¬ 
ing one or two whole rings and the connecting ligament above 
and below. To this, however, there is serious objection. When 
some of the rings are thus perfectly divided, the arch will be 
weakened ; its form will no longer be preserved; it will assume 
a sharper, roof-like shape ; and the calibre of the trachea will be 
afterwards considerably lessened in that part, and the consequence 
of this will probably be roaring to a greater or less extent. An 
immediate pressing danger may be removed, but a permanent 
inconvenience will be established. Here are three windpipes, on 
each of which you will perceive the operation of tracheotomy has 
been performed. The cartilage has united, but it has united by 
approximation rather than by reproduction; the front of the 
trachea is sharp instead of round; the sides are fallen in, and each 
animal was probably a roarer. 
Caution as to the Excision of the Rings .—I should advise you 
to adopt another method. Excise a portion of two of the rings, 
about half of their width, with the intervening ligament. The 
remaining portion will be sufficiently strong to retain the perfect 
arched form of the trachea; and if you thus have the aperture a 
little shorter, you must make it somewhat wider. 
But when you have done with, and want to close, this artificial 
opening, will the cartilage (the edges of which cannot approxi¬ 
mate) be reproduced? Yes, perfectly. Here is a beautiful speci¬ 
men of it. The rings are a little thicker and wider, but they are 
perfect, and the arch of the windpipe is altogether preserved. 
Well, then, gentlemen, if you are to excise a portion wider 
than it is long, you must not only dissect and turn back the cel¬ 
lular tissue, and the sterno-thyroideus muscle, to the required 
extent, but you must remove a portion of both, until you have 
sufficiently exposed the windpipe; your aperture will be about 
