RESPIRATION. 
312 
than in inspiration. This very important character of diseased 
respiration — roaring — is seated in the larynx, which is the ordi- 
nary situation of the disease, and arises from one or other of the 
morbid and abnormal changes before enumerated. 
A horse may roar from some obstruction within his head, his 
windpipe, or lungs ; but such cases are anomalous, and but rarely 
met with. This character of diseased wind is ordinarily the con- 
sequence of inflamed larynx, whether it is a complication of 
catarrh, strangles, or other affection ; and every man in the pro- 
fession that has seen much practice, must have experienced the 
fact. Our late Professor of the Veterinary College, Mr. Cole- 
man, a keen observer, and seldom wrong in whatever related to 
the horse, was of opinion that roarers were good winded ; — 1 will 
here introduce his own words : “ Roaring is produced from various 
causes: the membrane lining the windpipe becomes thickened 
from inflammation, and throw's forth coagulable lymph in various 
forms. Sometimes it is found extending across the windpipe; 
so that, when the air rushes out of the lungs, it goes against the 
lymph, and occasions roaring. It is truly astonishing that a 
roarer is a good-winded horse : to many it appears not so ; but 
yet it is a fact. You shall hear a horse in a coach roar for some 
little time before you meet him ; but bad as he appears, the 
moment he stops he shall cease to roar, and his breath shall be 
no more oppressed, nor his flanks heave any more than any other 
horse in the coach. The fact is, the horse’s lungs are good, but 
the coagulable lymph thrown across the windpipe intercepts the 
air passing from the lungs in expiration, and produces this noise.” 
I am not a little surprised that so ingenious and talented a man as 
Mr. Coleman was, should have formed such an opinion as to the 
ordinary seat, cause, and effect of roaring, that, because the lungs 
were not diseased, the horse’s wind was good. If there is ob- 
struction of the air passing to and from the lungs, the respiration 
is certainly imperfect. One portion of the respiratory machine 
is perfect, another part of it is defective, and this defect will and does 
interfere with the whole. However, practical information must 
always take precedence of theoretical knowledge, and the truth 
of the subject is, that roarers are not of good wind. If ridden to 
hounds, and the pace is fast, and the country heavy, they be- 
come blown, fall at their fences, stop, heave at the flanks badly 
enough, and the noise they make is very much increased. Horses 
that only whistle in strong gallopping will roar when pressed with 
hounds in deep ground. Mr. Percivall tried an experiment upon 
the trachea, by tying a tape round the tube one-third of the way 
down the neck. The animal roared when the ligature was mode- 
rately tight ; and when the windpipe was compressed to half its size 
it produced whistling. This appears the reverse of my state- 
