pink or purple, probably in proportion to the supply 
of acids or alkalies which the soil affords to the 
plant. Or, carrying our ideas somewhat farther, 
we should say, in proportion to the oxygen, hy- 
drogen, and carbon, which, by decomposition, the 
roots are enabled to collect from the substances with 
which they happen to come in contact. Still we 
would not mislead, by favouring an idea that vege- 
tables are wholly dependent on their roots, for a 
supply of nutriment to form their solid parts, for 
experiments have clearly shown that they collect a 
portion, and some authors have been bold enough to 
assert that they collect all, their food from the atmos- 
phere, whatever is imbibed by the roots acting 
merely, if we may be allowed the expression, as a 
stimulus to their appetites. 
Seeds which have been sown amongst pure sand, 
and even amongst pieces of metal, as leaden shot, 
&c. on being regularly supplied with distilled water, 
have been found to vegetate and grow to maturity ; 
ultimately yielding all the products of acids, alkalies, 
metals, earths, &c., which are common to those grown 
in soil. Hence it is certain that all these substances 
could not have been taken up by the roots, on ac- 
count of the water being freed, by distillation, from 
extraneous matter. Water is, in general, indispen- 
sable to vegetables, the decomposition of which may 
go far towards forming their solids ; and every hor- 
ticulturist knows that an evident modification of the 
effects of their atmospheric nutriment occurs from 
the exhibition of certain substances to their roots. 
-V 
In culture, it is requisite that the plants be at least 
eighteen inches apart. 
Bot. Mag. 2832. 
