18^ Scietitijic Intelligence, — Botany, 
of the organs of plants. An observation of much interest has 
been added by M. Chevallier, to those which we already possess 
upon this subject. He had announced, in conjunction with M. 
Lassaigne, the existence of sub-carbonate of ammonia, ready 
formed in the leaves of Chenopodium vulvaria ; and this assertion 
was scarcely credited. However, he has reason to congratulate 
himself upon the issue of the controversy to which this has led, 
since it has conducted M. Chevallier to the discovery of a fact 
equally curious with the former, though in a different way. It is 
now no longer an ammoniacal salt, forming part of the leaves, like 
so many other saline matters, but a continual exhalation of free 
ammonia, which may take place during the whole life of the plant. 
Certainly this first fact, which has not hitherto been noticed, opens 
a mine rich in important results, and we cannot help comparing 
it to the ingenious ideas of M. Robiquet regarding the aroma. We 
would also observe, that it is for the first time that the exhalation 
of a gas, containing azote, has been observed in vegetables ; and 
the facility with which the ammonia leaves this principle, may per- 
haps contribute to a better understanding of the formation of the 
azotic productions of the vegetable kingdom, the source of which 
has hitherto been more sought for in the atmospheric air, and in 
the nitrates or nitrites, which might occur in the soil. We 
transcribe M. Chevallier'’s observation verbally. Wishing to 
obtain the volatile alkali from the vulvaria, without employing 
the action of fire, and thus to prevent the objections which 
might be raised, I placed, in a large flower-pot, a lump of earth 
containing two stalks of Chenopodium. When I was assured 
that this transportation had not injured the vitality of the plant, 
.1 placed a glass funnel upon the pot, and luted the whole in 
such a manner, that the vapour, which was continually disen- 
gaged from the vulvaria, was obliged to pass through the upper 
part of the funnel. I adapted to this upper part, a tube which 
passed into a flask containing hydrochloric acid, diluted with wa- 
ter. All communication with the external air was besides inter- 
rupted by a second tube dipping into water. Scarcely was the 
ammoniacal exhalation in contact with the hydrochloric acid, when 
white vapours were perceived, which diffused themselves over the 
surface of the liquid, where they disappeared. This disengage- 
