ON RABIES CANINA. 
143 
as remarkable as that which we are now considering. The 
inflammatory fever of cattle and sheep often runs its course in 
two or three hours. The hoven of cattle is unlike tympanites 
in any other animal. The stomach-staggers of the horse bear 
little resemblance to repletion or over distention of the stomach 
in other patients. Psora or mange in the horse, the dog, and 
the sheep are very unlike. Affections of the chest, and their 
symptoms, duration, and termination are dissimilar in the biped 
and the quadruped, and in different quadrupeds. 
Not only do the symptoms of disease vary, but some animals 
are subject to certain maladies from which others are exempt. 
The horse has glanders, farcy, grease, and periodical opthalmia. 
The mule has rarely, and the ass never has, strangles ; and both 
of them escape the torture of contracted feet. Cattle, sheep, 
dogs, swine, know not any of these complaints. 
* The human being has, peculiar to himself, variola, scarlatina, 
and syphilis. 
Need we then wonder that there should be considerable dis¬ 
similarity in rabies ? 
Possibly a little reflection will lead us to expect some differ¬ 
ence, and precisely of the kind which we observe. 
Hydrophobia, the dread of water, and the horrible spasms 
which accompany the attempt to swallow any fluid, depend on 
the highly irritable state of the fauces and larynx. 
The larynx is the guard of the trachea during the act of 
deglutition. The epiglottis is then pressed down upon the 
orifice of the larynx, and the crico-arytenoidei muscles contract 
and accurately close the aperture. 
The larynx likewise discharges a more important function. 
It is the principal organ of voice. According to the number of 
vibrations performed by the chordae vocales in the act of expi¬ 
ration, is the precise tone uttered. A certain number of vibra¬ 
tions will produce a certain note. If the vibrations are quick¬ 
ened, the note assumes a higher place on the musical scale. If 
the number is lessened, the tone is proportionably graver or 
lower. The human voice is capable of nearly 500 different 
intonations, and each is produced by a determinate number of 
vibrations ; and these vibrations, their number ^continuing the 
same, are modified, partly by the mechanism of the fauces and 
mouth, but more by the larynx, to express every varying emo¬ 
tion and passion. The larynx then must be possessed of exqui¬ 
site sensibility to obey so rapidly, and with such strict and 
almost inconceivable accuracy, the mandates of the will. 
The voice of quadrupeds is more confined. There are fewer 
differences of intonation, and the expression of passion is more 
