484 MR. youatt’s veterinary lectures. 
duced, yet I have been puzzled with the complication of vessels 
around it, and in one case lost my patient by haemorrhage, 
which I could not arrest. The burnt cork I have given week 
after week with doubtful effect, and in the majority of cases with 
no effect at all. When the power of iodine in the dispersion of 
glandular tumours was first spoken of, I eagerly tried it for this 
disease, and I can recommend it to you as almost a specific. I do 
not recollect a case in which the glands have not very materially 
diminished, and in the decided majority of cases they have been 
gradually reduced to their natural size. I first tried an ointment 
composed of the hydriodate of potash and lard, with some, but 
not satisfactory, result: next was given the tincture of iodine in 
doses from five to ten drops, and with or without the local appli¬ 
cation ; but I found at length that the simple iodine, made into 
pills with powdered gum and syrup, effected almost all that I 
could wish. I begin with the eighth of a grain for a small 
dog, and rapidly increase it to half a grain morning and night. 
A larger dog may take from a quarter of a grain to a grain. I 
have in a few instances seen loss of appetite and slight emacia¬ 
tion produced; but then, suspending the medicine for a few 
days, no permanent ill effect has ever followed the exhibition 
of iodine. 
I shall hereafter have to speak of its beneficial effect in 
scirrhous tumours and cancer of the mammse—in sarcomatous 
enlargements about the joints of cattle, and in all that debili¬ 
tating train of disease connected with enlarged mesenteric glands. 
The Trachea. 
Description of the Trachea .—We will now follow the course 
of the inspired air from the larynx to the lungs, and we find it 
conveyed through a singularly constructed tube, passing along 
the anterior portion of the neck, and reaching from the lower 
edge of the cricoid cartilage to the lungs ; in the commencement of 
its course, somewhat superficially placed ; but, as it descends to¬ 
wards the thorax, becoming gradually deeper and more concealed. 
Anteriorly the trachea presents a hard cylindrical surface, 
somewhat flattened, connected with the thyroid glands, and to 
a greater or less degree covered by, as you will perceive, the 
sterno-thyro-hyoideus, the subscapulo-hyoideus, and the sterno- 
maxillaris muscles. Posteriorly the surface is softer, flattened, 
or rather depressed, and thickly covered by a laminated tissue, 
which supports the extremities of the cartilaginous rings, and sus¬ 
tains in their places the trachea itself, and the oesophagus, the 
carotids, the paivvagum and the organic nerves. 
Structure .—In order to discharge its functions as an air-tube. 
