3S8 Mr Murray on the Physhlbgy of the Root in Plants. 
fleet a portion of the cone of rays to A. In this way, five per- 
sons might see through the telescope at the same instant. 
Art. XXI. — On the Physiology of the Root in Plants. By 
John Murray, Esq. F. L. S., M. G. S., & M. W. S., Lee. 
turer on Chemistry. Communicated by the Author. 
nr 
JL HE fibres of the root have been generally if not universally 
considered as capillary tubes, destined to supply the plant with 
nutriment from the soil. But I am not aware of any direct ex- 
periments instituted on the subject, and recorded in the annals 
of science. 
Several circumstances concur to shade this received opinion 
with doubt. 
Van Helmont planted a willow in a given weight of earth. 
It was during five years carefully supplied with distilled water, 
and, at the termination of this period, it weighed 169 lb. 3 oz. ; 
while the earthy mass had sustained only a loss of 3 oz. In an 
analogous experiment made by Mr Boyle, the earth experienced 
no perceptible diminution. In the experiments of Duhamel and 
Bonnet, together with those of Tillet, Hales, and Braconnot, we 
find confirmation of the same interesting fact. 
The Tulip, Persian Iris, Jonquil, Narcissus, Hyacinth, &c. 
grow in bulb-glasses, supplied with pure water. White Cress 
and Mustard spring up readily on wetted flannel, and in the 
moist grooves of the “ lithovasa.” The Bean, Pea, &c. may 
be reared in damp cotton. Washed sand will serve others. 
These facts speak for themselves, and need not be extended. 
The “ Epidendrum flos aeris,” or air plant, with the pheno- 
mena presented by the Ficus Australis,” recorded in a former 
number of the Edinburgh Philosophical Journal, and which I 
myself saw luxuriant some months afterwards, shew that plants 
can exist independent of earth. 
The “ Mysembryanthemum,” ‘‘ Cactus,” &c. are little in- 
debted to the siliceous earth with which they are supplied, and 
I never witnessed the Cactus spinosisslmus” in such grandeur 
and majesty, as when growing from the surface of an arid rock. 
The Dodder and Misletoe may drink up the blood of the 
