OPERATIONS—TRACHEOTOMY. 447 
repeated enlargements will be avoided, and the more important struc- 
tures beneath the skin will be fairly brought into view. 
In the center of your division will appear two long muscies, joined 
together by a fine cellular union; that union you are to separate; it 
consists only of cellular tissue, and will necessitate more care than ex- 
ertion. Underneath the divided muscles will be found two others, 
smaller and paler, but also joined together by means of fine cellular 
tissue. These are also to be sundered, and then the trachea lies 
exposed. There is neither nerve, nor artery, nor vein to avoid, nor to 
take up in the performance of tracheotomy. All consists in making 
your primary incision large enough, and, subsequently, in not attempt- 
ing more than the division of two pairs of muscles. 
The commencement of the incision should be made at the spot already 
indicated. After the skin is cut through and the muscles are divided, 
two assistants should be obtained to hold them back, while a circular 
piece is excised from the cartilages of the exposed trachea. 
The trachea is formed of numerous cartilaginous rings each half an 
inch wide, but so united by elastic tissue that the whole forms one con- 
tinuous tube reaching from the head to the chest of a horse. If possi- 
ble, only two of these rings are to be interfered with; that is, a half 
circle should be cut out of each, which, with the elastic connecting 
medium, will make an opening of one inch in diameter. Both the rings, 
however, should be perfectly divided ; but a half circle should be excised 
from one, leaving a portion of cartilage to keep the remainder in its 
place. This matter, probably, may be made more clear by the engraving 
on the opposite page. 
After the first half circle is made, or when a portion is cut off the first 
cartilage, that piece should be bent outward. The elastic connecting 
substance will readily permit this to be done, and the current of fresh 
air admitted will considerably refresh the animal. The cartilage being 
bent outward, it should be leisurely transfixed by means of a sharp 
needle armed with strong twine. The string may be fastened to the 
button-hole of the operator’s waistcoat, and afterward the circle be 
leisurely completed. 
The twine is necessary because the spasmodic breathing has drawn the 
excised portion of cartilage upon the lungs, and thereby done as much 
mischief as the operator designed to do good. By bending the half 
circle outward, some relief is afforded to the breathing, and the charac- 
ter of the respiration partially benefited. The process is, however, ren- 
dered more safe by the employment of the loop; but care should be 
taken, when subsequently using the knife, not to cut the string. There- 
fore, before the circle is completed, the cartilage should be bent back- 
