197 
MR. YOUATT’s VETERINARY LECTURES. 
the membrane of the nose,and therefore frequently participate in 
all the affections of the nose. Their use is somewhat obscure ; 
the most probable supposition is that they‘arc connected w ith 
the voice; its convolutions, like those of a French horn, render¬ 
ing* the voice clearer and more sonorous. 
The situation of the frontal sinuses is indicated by small ele¬ 
vations or bumps. This is also evident in the sheep and the 
dog*, but not in the horse. [The different crania were exhibited]. 
An important use is occasionally made of the knowledge 
of the situation of the deepest portion of the frontal sinuses. 
A horse is brought to us for our opinion as to the existence of 
glanders. There is no ulcer—either no enlargement, or a trifling 
one, of the submaxillary glands—no adherence of them to the 
bone, but only a slight discharge of some glairy, sticky matter 
from the nose. 
If it is glanders, there will be extreme danger to the other 
horses, and it is necessary that the practitioner should decide as 
soon as possible. The most satisfactory proof would be the 
death of an ass or horse, otherw ise condemned to perish, w ho 
has been inoculated with the matter discharged, and who w ill 
die in four or five days if the horse is glandered. 
We may not, how ever, readily be able to procure a condemned 
horse, or even to purchase an ass; and if we could, we perhaps 
should have some difficulty in establishing our right either to 
destroy life, or to inflict suffering for such purpose. Now , the 
frontal sinus on either side communicates with the maxillary 
sinus, or rather the maxillary sinus is a continuation of the frontal 
inward and downward; and the maxillary sinus communicates 
with the sphenoidal and ediemoidal sinus; and from the whole 
of them there is an opening into the nasal cavity, between the 
bases of the turbinated bones, so that any fluid injected into the 
frontal sinus will pass into all the others, and escape through 
the aperture of the nose. 
Then a hole may be opened w ith a trephine (not w ilh the car¬ 
penter’s instrument the spill-gimlet) into the central and deep¬ 
est part of the frontal sinus on the suspected side. The extent 
of tne sinus I have described, and the deepest part of it, will be 
near the septum, on a line drawn across from one foramen supra- 
orbitale to the other. The hole will be opened on this line, and 
about a third of an inch from the septum. If we w ere to make 
the aperture too high, we should open upon the brain; if too 
low, we should penetrate into the nasal cavity. 
If a little tepid water is thrown into the opening, it will pass 
into all these sinuses, and wash out, or be tinged with their 
contents; and if glanders has long existed, although ulceration 
vol. iv. k e 
