BARBADOES AN D SOCOTRINE ALOES. 
485 
expense of the organic materials of the milk, which undergo 
a sort of combustion ; and, as the volume of the resulting car¬ 
bonic acid is greater than the volume of the oxygen absorbed 
it is clear that some of the oxygen of the organic bodies must 
take part in the formation of the carbonic acid. The author 
thus arrives at the conclusion that, at the same time the 
. carbonic acid is disengaged, bodies must be formed richer in 
carbon and hydrogen than the normal ingredients of milk, 
To determine the nature of these bodies, the author took two 
portions of the same milk, added alcohol to one, and sub¬ 
mitted it to analysis immediately, and analysed the other por¬ 
tion after having left it exposed to air for some days. The 
results of this and similar experiments repeated many times 
show—1. That milk which has been exposed to the air 
leaves considerably less solid residue thifh fresh milk. 2. That 
after milk has been exposed to the air it is richer in fatty 
matters than the same milk having alcohol added to it, and 
analysed immediately. It seems, therefore, that fatty matters 
are formed at the same time that carbonic acid is disengaged 
The author thinks that casein is the subject of these changes. 
THE COMPARATIVE VALUE OE BARBADOES AND SOCOTRINE 
ALOES. 
At a meeting of the Pharmaceutical Society a paper on the 
above subject was read by Mr. R. B. Giles, of Clifton. 
Mr. Giles doubts whether the comparative value of Bar- 
badoes and Socotrine aloes is fairly represented by their posi¬ 
tions in the London Pharmacopoeia. Socotrine aloes yield 
but 06 per cent, of aqueous extract, while Barbadoes will give 
as much as 80 per cent., and that kind the author believes 
to be the best which yields the largest amount of aqueous 
extract. Messrs. Smith, of Edinburgh, have found that aloine 
is prepared with greater facility from Barbadoes than from 
any other kind of aloes, and as the purgative property of 
the drug is supposed to be due to the aloine, that kind must 
necessarily be the best which yields the largest amount of 
the active principle. The author has substituted Barbadoes 
for the Socotrine in the various aloetic pills of the Pharma¬ 
copoeia, and has found the action of the preparations to be 
much improved by the change. It is worthy of remark, too. 
that Dr. Marshall Hall preferred the Barbadoes for his pilula 
aloes diluta; and Dr. Pereira observes, in his c Materia 
Medica/ that although the Socotrine has long been regarded 
as the best, he believed it to be inferior to the Barbadoes. A 
traditional preference, the author remarked, always attaches 
to articles scarce in the market, and this he thought was the 
