DISEASES OF RESPIRATORY PASSAGES AND ORGANS. 116 
east and west sides, were composed of brick, and the remaindet 
of boards, with joints battened. On the south, east, and west 
sides were glass windows; on the north side a door opened into 
the vegetable cellar, and on the roof there was a sky-light. A 
stairway led to the hay-loft above, another to the manure cellar 
below, both elosed by doors. The manure cellar was eight feet 
deep, and extended under the whole room. In the winter and 
sprinz of 1859 were confined forty head of cattle, arranged on 
three sides, with their heads toward the center; and within that 
center was another square, containing animals, so arranged that 
almost all were brought face to face. The manure cellar, about 
this time, contained from fifty to one hundred cords of manure, 
with from ten to twenty hogsinit. “This,” says Mr. CHENERY, 
“was my condition in the beginning of the year 1860. I had 
buried nearly half of my herd. I had experimentally acquired 
a knowledge of the fact that, in order to keep animals alive and 
in health, it was absolutely necessary that they should be supplied 
with pure air as well as with good food and pure water.” 
So far as the direct or indirect causes of pneumonia are con- 
cerned, we may safely infer that crowding and a bad system of 
ventilation includes them all. Yet, among horses, this disease 
often originates as the consequence of laborious work and feats 
af speed, which produces rapid and sometimes distressing respira- 
tions; but among cattle, whose powers of speed and endurance 
are not often put to the test, and whose natural respirations are 
slower, we infer that impure air, and perhaps exposure, too, are 
more operative than action or ill-usage. 
The stimulating and morbid action of an impure atmosphere 
may produce a disease of this character by its irrituting effects on 
the highly vascular membrane which lines the bronchi and air- 
cells. But then we all know that impure air fails to decarbonize 
the blood ; hence it is rendered unfit to enter the system. It has 
been noticed, however, by the drovers of the East, that when cat- 
tle have been driven a long distance without food, and in tem- 
pestuous weather, they are apt to become the subjects of diseased 
lungs. Fortunately for the poor brute, pneumonia is not so pain- 
fal as bronchitis, pleurisy, or laryngitis ; and having paesed through 
the acute stage, which is usually brief, it assumes a mild or sub- 
acute form, and ends in altered structure of the lungs, known as 
induration (hardening) or hepatization (liver-like), or it may end 
