348 
EFFECTS OF MEDICINE ON HOUSES, 
irritation, diarrhoea, prostration of strength and imperceptibility of 
pulse. The other was also similarly affected on the day follow 
ing. The latter, however, recovered ; while the former died, 
poisoned by the arsenic. In the end, the survivor was shot, on 
account of his disease having assumed the acute and incurable 
form. 
Here we have an example of little more than two scruples of 
arsenic producing gastro- enteritis to an extent that caused the 
death of one horse, and put in jeopardy the life of another. Idio- 
syncrasy, and other circumstances, unmentioned, unobserved, or 
unobservable, will, probably, be required to account for such 
strangely discrepant results. ’ One fact bearing on the explana- 
tion may, however, be mentioned here, and that is, the known 
difference, frequently coming under notice, between giving medi- 
cine in one large dose, and administering the same quantity in 
small or divided doses, at frequent intervals : it appearing, in the 
one case, that a large proportion of the medicine — especially of 
such a substance as arsenic, which is so sparingly soluble in 
water — passes out of the bowels unchanged, or, at all events, 
unabsorbed. Two ounces of cathartic mass, given in one dose, 
will be likely to purge a horse less violently and dangerously 
than a less quantity divided into drachm doses, and given at 
intervals of a few hours. I have frequently made the same ob - 
servation in regard to mercury and some other medicines. In- 
deed, among horse-dealers, it is a trite remark, that a dose of 
physic broken into three or four parts “ does a horse more good,” 
i. e . takes more effect upon him, than it would have done given 
in one dose. Dr. Philip, in advocating “The Influence of 
Minute Doses of Mercury,” observes, “ It is remarkable that, 
notwithstanding the general and long-continued employment of 
mercury, it should not have been known that all its constitutional 
effects, not excepting complete salivation, may generally be 
obtained by such doses as half, or even a third part, of a grain 
of blue pill taken three times a day : that is, a dose only equal to 
the twentieth, or thirtieth, part of a grain of calomel; for a grain 
of calomel is equal, whether we regard its purgative, or, when 
divided into minute parts, its alterative effects, to ten grains of 
blue pill. In another place we find the same eminent phy- 
sician setting it dow n as “ the result of his own experience ” 
(“ and there are few,” he tells us, u whose attention has been 
more directed to the subject”), “that, although there are circum- 
stances under which large doses of mercury are not only bene- 
ficial but essential, the quantity employed in this country has, 
on the whole, been, at least, ten times greater than that from 
which its most beneficial effects could accrue.” 
