404 MR. youatt’s veterinary lectures. 
If’ that has been intense, and especially if it has not been 
promptly attacked, the engorgement will long remain materially 
interfering with the function of the part. The Professor of the 
Veterinary College, and my valued friend Mr. Percivall, are ap¬ 
parently at issue here; the former attributing thick wind to 
effusion into the air-cells, and the latter to a thickening of the 
membrane lining these cells or the passages to them. The truth 
of the matter is, that they are both right. The effusion and the 
thickening, and particularly the latter, are causes of thick wind. 
The previous disease, when it can be ascertained, will determine . 
to which of the morbid changes of structure the impeded func¬ 
tion of respiration is to be attributed. 
Auscultation ,—If we know nothing of the previous disease^ 
auscultation will generally determine the matter for us. There 
will be no deficiency of murmur,—stilness,—at any point, but an 
increased sound everywhere—a whizzing—a kind of roaring. 
In some instances, both causes seem to have combined. While 
there has been thickening of the bronchial membrane, there has 
been deposit in the air-cells. So far then as thick wind is con¬ 
nected with previous disease, it is plainly referrible to one of 
these causes, hepatization of the substance of the lungs, and 
obliteration of the air-cells, or thickening of the lining mem¬ 
brane, and diminished calibre of the passages leading to these 
cells. Whether the cells are fewer, or the passages are con¬ 
tracted, only a less quantity of air can be admitted to arterialize 
the blood at each inflation of the chest, and then the act of respi¬ 
ration must be oftener, and consequently more forcibly performed, 
and that in pi'oportion to the hepatization or engorgement. 
Treatment ,—Of this, gentlemen, I have little to say. I know 
not by what means I can excite the absorbents to take up the 
solid organized mass of hepatization, or to restore the membrane 
of the cells and the minute vessels ramifying over them, now 
confounded and lost. I have a somewhat better chance, and yet 
not much, in removing the thickening of die membrane;—coun¬ 
ter-irritants, extensively and perseveringly applied to the external 
parietes of the chest, might do a little. If thick wind imme¬ 
diately followed bronchitis, it would certainly be justifiable prac¬ 
tice to blister the brisket and sides, and that repeatedly ; and to 
administer purgatives if we dared, or diuretics, more effectual 
than the purgatives, and always safe. 
Food ,—Our attention must be principally confined to diet and 
management. A thick-winded horse should have his full pro¬ 
portion, or rather more than his proportion of corn, and a dimi¬ 
nished quantity of less nutritious food, that the stomach may 
never be overloaded, and press upon the diaphragm, and so upon 
