422 
LECTURES ON THE BRITISH PHARMACOPOEIA. 
It should be especially noticed that the leaves and flowering-tops are directed 
to be gathered when about one-third of the flowers are expanded. We are very 
glad to find that the directions given in the British Pharmacopoeia as to the 
time of gathering the leaves, etc., of Aconite, Belladonna, Conium, Ilyoscyamus, 
and other herbaceous plants are very explicit, as in previous Pharmacopoeias no 
precise information upon that point has been given. The opinion commonly en¬ 
tertained by vegetable physiologists until lately, was—that the best time for 
taking the herbaceous parts of plants for use in medicine, as a general rule, was 
just at the commencement of the flowering stage; and the reason adduced for 
the selection of that period was because the process of flowering, and more 
especially that of fruiting, required a great supply of nourishment, and hence, 
as a necessary consequence, a corresponding weakening of the vital activity of 
the plant was produced. 
In a paper read before the Pharmaceutical Society “ On Expressed Juices 1 ’ by 
Mr. Squire, in August, 1841, and which was published in the first volume of 
the Pharmaceutical Journal,* he states, U I am persuaded that the juice is in 
the greatest perfection in the plant when more than half the flowers are fully 
blown.” This was, I believe, the first time that public attention was especially 
called to the subject; and although I do not agree with the statement of Mr. 
Squire, that a general rule can be laid down which shall be applicable to the 
time of collecting all medicinal herbaceous plants, yet I do agree that the best 
time for collecting the herbaceous parts of plants is after the period of flowering 
has commenced ; that period, however, must vary to some extent, in different 
plants. I think that the authors of the Pharmacopoeia have generally mentioned 
the best period for collecting medicinal herbaceous plants, and this is one of the 
points connected with the preparation of the Pharmacopoeia in which the 
opinions of practical pharmaceutists have been found of especial value. 
In a lecture which I delivered in this Institution, “ On Plants in a State of 
Life,” more than two years since, and which was afterwards published in the 
Pharmaceutical Journal, I endeavoured to explain why the herbaceous parts 
of plants should be taken after the flowering stage had commenced, as follows :— 
“ There are two series of compounds formed by the action of light and air in 
plants, those of one series having for their object the nutrition of the plants in 
which they are formed, and being directly concerned in their growth and de¬ 
velopment,—and those of the other series called secretions, placing no active part 
in the plant after their perfect formation, the latter ( secretions ) being also 
commonly formed later in the life of the plant. . . .In the process of flowering, 
the only compounds that are taken up in any amount are those which are con¬ 
cerned in the growth and development of new tissues ; no further growth can 
therefore take place, to any great extent at least, in the vegetative organs of 
the plant; but the secretions, by the removal of these products, become more 
concentrated, and the organs in which they are produced, by being left for a 
longer period in connection with the plant, have time to elaborate them more 
perfectly.”! 
Armoracia. — Fresh Horseradish root is directed to be employed in the only 
preparation in which it is ordered, namely, the Spiritus Armoracise Compositus. 
As the root, according to our experience, varies much in its pungent odour and 
taste at different seasons of the year, being much weaker in the summer months 
than in the early spring or late autumn, it would have been advisable to have 
directed the Compound Spirit of Horseradish to be prepared at the latter seasons. 
Had the Infusum Armoracia? compositum of the London Pharmacopoeia been 
retained, the root must have necessarily been obtained at the time in which such 
infusion was ordered ; but it is not so with the compound spirit. The fact of 
* PIiarm. Journ., vol. i. p. 90. 
t Pharm. Journ., vol. iii. 2nd ser. p. 475. 
