NOTES ON THE PHARMACOPEIA. 
525 
had alluded to alum as ordered in the Pharmacopoeia. For the first time, the 
present edition directed the use of ammonia alum instead of potash alum, which 
was previously ordered. He was not aware, until informed by Mr. Bland that 
evening, that potash alum had again made its appearance in commerce. At the 
time the Pharmacopoeia was under preparation, and at various times, he bad 
tried to obtain potash alum, and had entirely failed to do so. At one period it 
seemed to have gone wholly out of commerce. There was no doubt that am¬ 
monia alum was quite as good for all the purposes to which it was applied in 
pharmacy as potash alum ; and if both were in commerce, he thought they were 
justified in ordering that which was most generally to be met with. Then with 
reference to iron, certainly there might be minute traces of iron in most speci¬ 
mens of alum as met with in commerce, but they ought to stand, and generally 
would stand the tests given in the Pharmacopoeia. They had endeavoured to 
arrange the tests generally throughout the Pharmacopoeia with the understand¬ 
ing that it was not necessary to look for chemical purity in the substances used 
in medicine. If it were to be obtained, they would generally have to obtain it 
at a cost which was very disproportionate to any advantage which would result 
from it. At the same time tests for objectionable contaminations were given, 
and any appreciable amount of iron would be objectionable in such a salt as 
alum. With reference to Mr. Bland’s remarks on oxide of antimony, all he 
could say was that he thought the description given in the Pharmacopoeia 
exactly represented the article as it would be produced in the ordinary way, as 
an article of chemical manufacture. He had never himself obtained oxide of 
antimony by precipitation in a perfectly white state, and such a result would 
be perfectly new to him. Then Mr. Bland had referred to the subject of chlo¬ 
roform, and had inquired whether it could be made from methylated spirit, so 
as to be as pure and as fit for medicinal use as that made from pure spirit. 
First of all, he (Dr. Redwood) would say, that the Pharmacopoeia did not in 
any case recognize the use of methylated spirit, and it indicated, in reference to 
this preparation especially, rectified spirit as the source from which it was to be 
obtained. But the question having been put to him, he would reply to it to 
this effect: that at the Exhibition of 1862, there were a great number of 
samples of chloroform exhibited, some prepared with pure spirit and some with 
methylated spirit, and the jury who had to examine and report upon these pre¬ 
parations, devoted a great deal of time to the examination of the specimens of 
chloroform, with the view of ascertaining whether they could detect any differ¬ 
ence between that made from pure spirit and that made from methylated spirit, 
and the conclusion they came to—and he was a member of the jury,—was that 
there was no difference to be detected by any method of examination that they 
could resort to. At the same time, he believed that in order to get the chloro¬ 
form made from methylated spirit in so great a state of purity as those speci¬ 
mens were—and they were specimens which had been sent from a house in 
Scotland celebrated for the manufacture—very great pains must be taken in the 
process of purification. But he would state further, that very pure methylated 
chloroform could be obtained in commerce without difficulty, and some of these 
specimens, he believed, were fit for medicinal use. Mr. Bland had, further, 
referred to sulphate of quinine, and the process given in the Pharmacopoeia with 
reference to it. lie (Dr. Redwood) knew of no valid objection to this process. 
Mr. Bland said he had not succeeded in getting more than two or three per 
cent, of sulphate of quinine from cinchona bark by that process; and he (Dr. 
Redwood) could only say that if he had succeeded to that extent he had suc¬ 
ceeded very well. 
Mr. Bland, interposing, said he did not say that he got this result from the 
process in the Pharmacopoeia, but from a cold process of his own. He also 
stated that he had never succeeded in obtaining so much as 3 per cent, of pure 
crystallized sulphate of quinine, 2*6 per cent, having been the largest quantity. 
