181 
of plants, as far as it is supplied by the soil in which they vege- 
tate. It is probable that it is imbibed by the extremities 
of the roots only ; for Duhamel observed, that the portion of 
the soil which is soonest exhausted is precisely that part in 
which the greatest number of the extremities of roots lies. This 
shows us the reason why the roots of plants are continually 
increasing in length. By this means, they are enabled, in some 
measure, to go in quest of nourishment. The extremities of the 
roots seem to have a peculiar structure adapted for the imbi- 
bing of moisture. If we cut off the extremity of a root, it never 
increases any more in length : therefore its use as a root has 
been in a great measure destroyed. But its sides send out 
fibres which act the part of roots, and imbibe food by their ex- 
tremity. Nay, in some cases, when the extremity of a root is 
cut off the whole decays, and a new one is formed in its j)lace. 
This, as Dr. Bell informs us, is the case with the hyacinth. 
The extremities of the roots contain no visible opening. Hence 
we may conclude that tlie food which they imbibe, whatever it 
may be, must be in a state of solution; whilst the absolute ne- 
cessity of water renders it probable that water is the solvent. 
And, in fact, the carbonaceous matter in all active manures is 
in such a state of combination that it is soluble in water. All 
the salts which we can suppose to make a part of the food of 
plants, are more or less soluble in water. This is the case also 
witli lime, whether it be pure or in the state of a salt ; magne- 
sia and alumina may be rendered so by means of carbonic acid 
gas; and Bergman, Macie, and Klaproth, have shown that even 
silica may l>e dissolved in water. We can see, therefore, in 
general, though we have no precise notions of the very combi- 
nations which are immediately imbibed by plants, that all the 
substances which form essential parts of that food may be dis- 
solved in water.” See Thomson’s Chemistry of Organic Bodies. 
183 Chrys.antiiemums, Cclture of. Although our own prac- 
tice inclines us to prefer propagating Chinese Chrysanthemums 
from cuttings, still we are free to confess, that where they can 
be divided, trained to a wall of good aspect, and have a light 
rich compost to grow in, they become exceedingly splendid. 
The late 3Ir. Haworth, of Chelsea, paid much attention to this 
plant, and as he so decidedly preferred division of the old plants, 
we will take the liberty of copying his directions, for the benefit 
191 ACCTARIUM. 
