PRESENCE OF CARBON IN LIVING PLANTS. 
335 
only in our own country, but also in others, as will be seen by the 
Archbishop of Sweden to the Royal Agricultural Society at Orebro, 
which will be found in another part of this work; and I trust that 
what I have said will shew that it ought to be vindicated and en¬ 
couraged by every one who has the welfare of agriculture at heart, 
untill another shall be produced superior to it, which, assuredly, has 
not yet been done. 
NATURAL HISTORY. 
ARTICLE XIII.—ON THE PRESENCE OF CARBON IN 
LIVING PLANTS.—Bv J. B. Jun. 
My attention was directed to the subject of the present paper by a 
doubt expressed by the Author of the Domestic Gardener’s Manual, 
as to the presence of carbon having been proved to exist in the living 
plant, and on reviewing the researches of Sir H. Davy on this par¬ 
ticular branch of chemistry, I could not help been struck at the mani¬ 
fest source of error to which his deductions were liable, in consequence 
of the air in the receiver having free communication with the mould 
in which the plant over which it was inverted, was growing, so that 
any decaying vegetable substance in the mould would undoubtedly 
impregnate the air in the receiver with the gases which are so 
copiously evolved during the process of vegetable decomposition ; and 
though the analysis of the air in which the plant had been growing 
might afford a larger portion of carbonic acid gas than the external 
atmosphere, it could not with certainty be deduced that that ex¬ 
cess was given out by the plant, nor would the conclusion that the 
plant had only absorbed a certain portion be more correct, seeing 
that the gas was liable to be supplied by the mould in which the 
roots grew. In order to avoid the above source of error, I had a pot 
made exactly like a common flower pot, with a Bygrave slug preventer 
fastened at the top of it, only made all in one piece ; but for fear the 
description should not be sufficiently intelligible, I herewith send 
you a section of it. (Fig. a.) I 
then placed a small pot containing 
a geranium inside of the other, 
which was made sufficiently deep 
to allow it to sink two inches below 
the top. These two inches were 
filled up with well tempered clay, 
to within about half an inch, 
which w r as filled with bees’ wax 
and resin, run over it while hot. 
