£45 
matter in the solutions. Plants of mint grew luxu - 
riantly in all these solutions ; but least so in that 
of the astringent matter. I watered some spots of 
grass in a garden with the different solutions sepa- 
rately, and a spot with common water : the grass 
watered with solutions of jelly, sugar, and mucilage, 
grew most vigorously ; and that watered with the 
solution of the tanning principle grew better than 
that watered with common water. 
I endeavoured to ascertain whether soluble veget- 
able substances passed in an unchanged state into 
the roots of plants, by comparing the products of 
the analysis of the roots of some plants of mint 
which had grown, some in common water, some in 
a solution of sugar. 1£0 grains of the roots of the 
mint which grew in the solution of sugar, afforded 
five grains of pale green extract, which had a 
sweetish taste, but which slightly coagulated by 
the action of alcohol. 1£0 grains of the roots 
of the mint which had grown in common water, 
yielded three grains and a half of extract, which was 
of a deep olive colour ; its taste was sweetish, but 
more astringent than that of the other extract, and 
it coagulated more copiously with alcohol. 
These results, though not quite decisive, favour 
the opinion that soluble matters pass unaltered into 
the roots of plants ; and the idea is confirmed by 
the circumstance that the radical fibres of plants 
made to grow in infusions of madder are tinged 
red ; and it may be considered as almost proved 
by the fact, that substances which are even poi- 
sonous to vegetables are absorbed by them. I 
introduced the roots of a primrose into a weak 
r 3 
