EFFECTS OF SOIL AND CULTIVATION ON PLANTS. 
213 
It lias been stated that henbane and foxglove lose their activity by drying, 
in consequence of a reduction of their active principle. This I am not able 
to support. I find that their active principles, as well as those of many other 
plants, are rendered less soluble, from a modified state of combination being 
produced. 
By imperfect drying, fermentation might arise which might alter the re¬ 
medial value of any preparation from these plants; but experiments are still 
wanting to prove that active principles are capable of conversion by direct 
fermentation, or decay, and toxicologists assure us that organized structures 
are not able to transform into other compounds the elements which form the 
molecule of an alkaloid. 
Many growers have informed me that they are obliged to let their crops 
stand until the supply from foreign growers is ready for the markets; the re¬ 
sult is, that in many cases the plants are allowed to remain some time after 
flowering before the officinal parts are collected, and since my experiments 
are so strongly opposed to such practice being allowed, it has suggested itself 
to me that a plan which might remedy this would be for pharmaceutists to 
insist that the plants should be supplied with their flowers, which would serve 
as a guarantee for the perfection of their condition. 
It is much to be regretted that chemists, in determining the constituents 
of a plant, have overlooked the important relation which exists between the 
assimilative action of plants for the mineral constituents of the soil. In the 
case of plants supplied with highly nitrogenized manure, I have always found 
a much larger proportion of phosphates and nitrates, and variable proportions 
of soda salts ; the latter can only be considered as arising from the manure. 
As such plants invariably yield a greater number of flowers, the analysis of 
the parts of the plant, if allowed to perfect its flowers, can only be complete 
when the proportions of its separate parts are only considered. 
I met with a most singular illustration of how the mineral constituents of 
a plant may vary, in some foxglove plants, which, in order to facilitate my 
experiments, were transplanted in the early spring. These plants were taken 
from a wood near Wimbledon, with a portion of the soil for analysis. The soil 
consisted principally of decayed vegetable matter, and yielded on incinera¬ 
tion about 9 per cent, ashes, of which 7 per cent, was soluble in water and 
dilute sulphuric acid, the remaining 2 per cent, consisted almost entirely of 
oxide iron and silica. The complete analysis of these soils will be found in 
Appendix A. 
The incineration of the leaves and stalks yielded about 4 per cent, ashes 
when taken from the soil referred to, and, after removal to a slightly manured 
soil, yielded nearly 10 per cent, ashes. The juice extracted from the leaves in 
July gave considerable quantities of phosphates, nitrates, and chlorides, with 
traces of sulphates. I analysed at the same time the juice extracted from the 
leaves of the plants growing on the original soil, it yielded larger proportions 
of chlorides and sulphates. The yield of ashes, on the incineration of the 
leaves and stalks, was about 6‘3 per cent. 
The analysis of the soil to which the plants were removed is given in 
Appendix B. 
My experiments on belladonna, which have been confined to cultivated 
specimens, support the conclusion that very marked differences in the che¬ 
mical composition of the soil gives rise in a corresponding degree to diffe¬ 
rences in the saline constituents of a plant, and that where the differences are 
but slight, no sensible difference is produced in the amount of mineral matter 
contained in the plant. 
From the seeds of these plants I obtained:—Albumen, gum, inulin, phos¬ 
phate of soda, nitrate of potash, chloride of potassium, sulphate of potash, an 
