VEGETABLE PHYSIOLOGY. 
THE LEAVES OF PLANTS. 11 
them with circumstances congenial to their growth, in those 
positions which we can appropriate to their use. 
There are several species of Balsams in our gardens, but the 
gayest and best of all is Impatiens Balsamina (Balsamina 
hortensis of Desfontaines). There are others, such as I. Noli- 
me-tangere, I. coccinea, I. biflora, and some more recent intro¬ 
ductions from India : the first of these is found wild in our own 
country, and other parts of Europe; but the double Balsam 
of our gardens is the only one we have at present worth 
growing. 
Balsams, as border flowers, may be showy enough in some 
situations, and may flower well enough in some seasons, but 
they are more frequently rendered unsightly by heavy rains 
and cutting winds. My opinion is, that our common garden 
Balsam can be grown to far greater perfection than it generally 
attains. 
Buckingham Palace Gardens, October 31. 1844. 
[Balsamina hortensis is doubtless the best of this family for 
cultivating as a tender annual; but several of the half hardy 
species, introduced within the last few years from the northern 
provinces of India, are certainly highly deserving of cultivation 
in the flower-garden. Probably Mr. Watt means that the 
double Balsam is the only one adapted for being grown within¬ 
doors. T. M.] 
VEGETABLE PHYSIOLOGY. — THE LEAVES OF 
PLANTS. 
By Mr. T. Moore. 
(Continued from Vol. V. p. 180.) 
The functions of leaves are to act as organs of nutrition, for 
by them respiration and assimilation are carried on. They act 
as elaboratories, in which the crude sap impelled into them from 
the stem evaporates about two thirds of its water, and becomes 
united with the carbon of the atmosphere ; and they furnish 
nutriment to the young fibres, which pass from them, and the 
buds, in the form of alburnum and liber; and also to all the 
