640 DISEASES OF THE STOMACH AND INTESTINES. 
repeated doses of calomel; in two cases we recollect where 
this agent had been employed daily for some time, the 
patients were incautiously taken out before they had quite 
recovered; and in both instances diarrhoea supervened, and 
destroyed them in a short time, seemingly from the ex¬ 
hausting effects of the evacuation, as in the one that was 
examined after death no indications of inflammation were 
present. 
Cattle and sheep are frequently affected from very slight 
causes, and often suffer only a temporary inconvenience. 
The younger subjects, however, often succumb, and in 
certain seasons, particularly in some localities, the disease is 
extensively fatal—calves and lambs suffering especially from 
its ravages. In a chronic form, diarrhoea or dysentery is 
frequently present in cattle, producing extreme emaciation 
and serious organic derangement. In many instances we 
have found the liver extensively diseased, and the mucous 
membrane in a state of extreme irritation, variously coloured 
in patches, and marked by a general absence of its normal 
epithelium. 
General characters of the disease .—The debility which results 
from diarrhoea is both rapid and decided, at least in those 
cases which may be termed acute; this debility cannot be 
explained by reference to the nutritive value of the expelled 
material, because the greater portion is merely dilute serum 
in conjunction with the effete solids. It is quite true that 
digestion is interrupted, and that whatever aliment is con¬ 
sumed is hurried through the digestive tube in such a manner 
as to prevent the proper appropriation of its elements; but 
the amount of prostration produced by a few hours’ excessive 
evacuation is beyond all comparison greater than would 
follow a total abstinence for a much longer period. 
Similar exhaustion, we are aware, would happen from loss 
of blood. This circumstance we are in the habit of explaining 
by taking into account the value of the fluid, but a little 
reflection will show that loss of nutriment cannot, of itself, 
occasion such immediate results. We are thus compelled 
to seek for a less exceptional argument. 
Circulation we may assume to be dependent for its perfect 
performance upon a due supply of circulating fluid, which 
may offer sufficient resistance to the contracting heart and 
vessel; deficiency of quantity, irrespective of all other con¬ 
ditions, must lead to imperfect circulation, from the diminu¬ 
tion of the elastic medium upon which the vessels may exert 
their force with effect, the same force being inoperative when 
expended upon a space only partly occupied by the elastic 
