On the Rose of Jericho. 363 
to imbibe a larger portion of water. But here it must be recol- 
lected that no expansion took place, and perhaps the absorption 
ef the liquid was confined to the stems. 
Exp. 2.—In a second experiment both specimens were again 
immersed in water, which rose so high as to cover the lower di- 
visions of the ramifications. In five hours the expansion was 
complete. But when the level of the water was diminished by 
the absorption and evaporation, contraction of the branches 
immediately commenced ; and when the vessels were again filled 
up, both specimens were restored to a state of full expansion. 
During the period of immersion, which was continued forty-two 
hours, the alternate expansion and contraction were several times 
repeated. At the conclusion of this period, when both specimens 
were fully expanded, they were weighed, and it was found that 
the augmentation of weight acquired by the short-stemmed spe- 
cimen amounted to 37 grains, and therefure it weighed 147 grs. 
The weight gained by the long-stemmed specimen was equa! to 
28 grains, for it weighed 118 grains.—Fig. 1, Pl. V. is a view 
of one of the specimens in its cuntracted state, and fig. 2 is the 
same specimen in its state of expansion. 
From the experiment now detailed, it appeared that the 
amount of absorption, or the increase of weight gained by each 
specimen, approaches very nearly to the ratio of their respective 
weights in the dried and contracted state. For 37, the additional 
weight of the heavier or short-stemmed specimen, is nearly in the 
same proportion to 110, the original weight, as 28 is to 90. 
It might have been desirable to vary these experiments by im- 
mersing the specimens in water at different temperatures; but as 
they were considered valuable and curious on account of their 
resuscitating quality, it seemed unsafe to employ water much in- 
creased in temperature, in case that property should be dimi- 
nished or destroyed. 
In considering the resuscitating power of this plant by the 
absorptign of water, is it to be supposed that any portion of the 
living principle still remains with it? A dried piece of wood ab- 
sorbs water; but this is obviously dependent on the attraction’ 
between the fibres of the wood and the water; and no change 
that indicates the presence of a living agent appears. Some 
plants, and particularly of the tribe of Mosses, after being dried, 
when exposed to moisture or immersed in water, ina short time 
exhibit all their freshness and vigour. 
I have only further to observe, that in the, Rose of Jericho, the 
absorption does not take place at the extremity of the stem, as 
is proved by the first experiment, but at the commencement of 
the ramification, as appeared from the result of the second ex- 
periment; for the full expansion was not produced till the water 
rose to that point from which the branches pass off. 
Edinburgh, May 1821. Z2z2 LXXVI. Con- 
