YV. Extradt of a Memoir, and Experiments on the Nutrition 
of Plants. By M. Rarfy, Meffer 4 in the Office of Com 
merce at Copenhagen *, ‘ 
H ASSENYRATZ confiders carbon as the fubftance which 
nourifhes vegetables +. Ingenhous, in his work on the nu- 
trition of plants, publifhed in 1797; endeavours to prove, 
that if carbon has any influence in this refpeét, it can be 
only in the ftate of carbonic acid, as that acid is abforbed 
and decompofed ¢ by vegetables ; while the ligncous carbon, 
furnifhed by Nature, produces no effeé&t on the expanfion of 
plants. Mr. A. Young has endeavoured to demonftrate the 
fame thing by experiments. M. Rafn, defirous of difcover- 
ing the truth amidft thefe contradi@ory opinions, made, for 
three years, a feries of experiments, from which he con- 
cludes, by the expanfion, fize, and colour of the plants em- 
ployed, that carbon, either vegetable or animal, has a de- 
cided influence in the nourifhment of vegetables. What is 
new, and particularly worthy of remark in thefe refearches, 
is, that, according to M. Rafn, the carbonic acid produces 
exactly the fame effeét as charcoal of wood. The following 
are the, experiments which conduéted the author to iis 
refult :— 
Having half filled a large box with brick-kiln rubbith, or 
pounded tiles, which he covered with a layer of vegetable 
earth, he placed over the latter a ftratum of carbonate of 
Jime (pounded limeftone) and alum, and then two or three 
of vegetable mould, in which he fowed barley. He pre- 
fumed that the fulphuric acid of the alum, abandoning the 
argil to join the lime, with which this acid hus greater affi- 
* Tranflated fiom the Danith, with notes by C. Vauquelin and Brogy 
niart. 
t This opinion of C, Hafenfratz appears to be very probable; but, as 
he fays, the caibon muft be held in folution by hydrogen gas, by water, 
by that faponaceous extraét which feparates from vegetables when in a 
ftate of putrefydlion, or by any other liquid. 
{ This decompofition is poflible, but it has not yet been proved by 
any direét experiment, 
Vou. V, Wh nity, 
