Vegetable Physiology. 141 
Similar trials were made with a weak solution of marine salt, and 
with a like result. Learning from M. De Candolle that marine plants 
when transported ina healthy situation, frequently. grow well ata 
distance from the sea, and that in such cases the soil in which they 
grow contains more salt than the surrounding soil, the author endeav- 
ored to imitate nature by taking a few common plants, placing their 
roots in rain water, and wetting their leaves with a solution of ma- 
rine salt. None of the salt was discoverable in the water, and it 
may therefore be inferred either that solutions of salt cannot imitate 
the delicate process of nature, or perhaps more probably that soda 
plants alone have the power of absorbing by their leaves, marine 
salt and rejecting a portion of it by their roots. 
There can be no doubt then that plants have the power of reject- 
ing by their roots, soluble salts which are injurious to vegetation. The 
author gives a few interesting details of experiments on some partic- 
ular families of plants. 
Leguminous Plants.—The only plants which he tried of this fam- 
ily were peas and beans. They live and grow well in pure water. 
After sometime, the liquid, being examined, has no sensible taste, its 
smell is faintly herbaceous. It is quite clear and almost colorless in 
the case of kidney beans, (haricots,) more yellow in peas and com- 
mon beans, (feves. ) The fluid when examined by chemical tests, 
, &e. is found to contain a matter eee Ranlegees to gum 
and a little caafiediitie of lime. 
It was found that when the water in which — plants had ved 
was pretty well charged with this excrementitious matter, fresh plants 
of the same species soon withered in it and did not live well. To 
ascertain whether this was for want of carbonic acid in the quid, 
(which plants derive from the earth as well as from the air,) or from 
the | presence of the excreted matter, which they repudiated, the au- 
thor put into the fluid, some plants of another family, and especially 
‘wheat. ‘This lived well, the yellow color of the fluid became less 
intense, the residuum less considerable, and it was evident that the 
new plant absorbed a portion of the matter discharged by the first. 
It was a kind of rotation experiment performed in a bottle, and the 
result tends to confirm the theory of De Candolle. It is not impos- - 
sible that by experiments of this kind, results may be obtained of prac- 
tical importance to agriculture. The author would infer that be 
may follow with great advantage a crop of beans. 
