256 
BRITISH PHARMACEUTICAL CONFERENCE. 
Tinct. Aurant .—The 21 days’ maceration with percolation yielded no less 
than 5 grs. more than any of the other processes, and the colour and aroma 
were decidedly preferable; and the same result was obtained with an additional 
gr. i. from a specimen tincture obtained from a respectable chemist. 
Tinct. Calumb .—Whilst the B. P. has 54| grs. to 36 grs. L. P., the result is 
the same, except with the 21 days’ maceration, where the yield is one-fiftli 
more. 
Tinct. Catechu is also a remarkable illustration of the advantage of addi¬ 
tional maceration. 
Tinct. Cinchon. Co. yields a larger amount of extractive matter, but only in 
proportion to the quantity of solids given, being so much greater in the L. P. 
over the B. P. I had tivo samples of this tincture given me by friends, one of 
them by percolation only, seems an exception to the rule, for it yields 2 grs. 
more than by 21 days’ maceration and percolation ; this may arise from a 
difference in the kind of bark used. 
Tinct. Ilyoscyami .—The results here by the L. P. process are very different 
from the preceding ones, but it is readily accounted for, as the, lamina only of 
the second year’s herb, with the petiole and midrib removed, was used, and 
an excellent tincture the result. 
Tinct. Myrrh .—In mixing the myrrh with the spirit, it was found most 
desirable to add the myrrh to the spirit, and then it was easily shaken up, 
but if the spirit be added to the myrrh, the mass coheres at the bottom of the 
vessel and is with difficulty separated. 
I think it unnecessary to allude to any other of the tinctures, except Tine- 
tura Opii. It will be seen that a remarkable difference is shown, by a spe¬ 
cimen (No. 12) procured from a friend who made it by percolation only, and 
Nos. 11 and 13. It can only be accounted for by a difference in the quality 
of the opium used. No. 11 was made with the gum, not with the powder, 
and although the yield of extractive matter was less than No. 12, the colour 
and peculiar flavour were quite as strong. I thought it desirable to procure 
some other preparations, besides those made by my son, as a test to confirm 
or otherwise those previously experimented upon. I regret that other en¬ 
gagements prevented me from trying the whole of the tinctures of the B. P., 
but I trust sufficient has been adduced to excite attention and further interest 
in the subject by those better able and with more time at their disposal, for 
carrying out the results efficiently. 
Brighton. 
ON THE CULTIVATION OP MEDICINAL PLANTS AT MITCHAM. 
BY THOMAS T. P. BRUCE WARREN, PREPARATEUR IN TIIE LABORATORY 
OF MR. WILLIAM IIOOPER, 
7, Pall Mall Bast, 55, Grosvenor Street, and Mitcham. 
(Bead at the Bath Meeting of the British Pharmaceutical Conference , Sept. 1861.) 
The medicinal plants principally cultivated at Mitcham are—Lavender, Pep¬ 
permint, Chamomiles, lloses, Liquorice, and Henbane. Large quantities of 
Poppies, Bosemary, Squirting Cucumber, Belladonna, and Pennyroyal are also 
cultivated, and smaller quantities of Spearmint, Marshmallow, Ilorehound, Fox¬ 
glove, Stramonium, etc. 
The amount of ground laid out for the cultivation of medicinal plants varies 
every year; the total acreage under cultivation at present is 736 acres, and 
consists of— 
