ON THE NITROGEN OF PLANTS. 
237 
consequence of the neutral salt being converted by loss of am- 
monia into an acid salt. The free acid which is thus formed 
is a source of loss to the manufacturers of sugar from beet- 
root, by changing a part of the sugar into uncrystallizable 
grape sugar and syrup. 
The products of the distillation of flowers, herbs, and roots, 
with water, and all extracts of plants made for medical pur- 
poses, contain ammonia. The unripe, transparent, gelatinous 
pulp of the almond and peach emit much ammonia when 
treated with alkalies, — (Robiquet.J The juice of the fresh 
tobacco leaf contains ammoniacal salts. The water which 
exudes from a cut vine, when evaporated with a few drops 
of muriatic acid, also yields a gummy deliquescent mass, 
which evolves much ammonia on the addition of lime. Am- 
monia exists in every part of plants, in the roots (beet-root,) 
in the stem, (of the maple-tree,) and in all blossoms and fruit 
in an unripe condition. 
The juice of the maple and birch contain both sugar and 
ammonia, and, therefore, afford all the conditions necessary 
for the formation of the azotized components of the branches, 
blossoms, and leaves, as well as those which contain no azote 
or nitrogen. In proportion as the developement of those 
parts advances, the ammonia diminishes in quantity, and 
when they are fully formed, the tree yields no more 
juice." 
"Nitrogen is found in lichens, which grow on basaltic 
rocks. Our fields produce more of it e than we have given 
them as manure, and it exists in all kindsof soils and minerals, 
which were never in contact with organic substances. The 
nitrogen in these cases could only have been extracted from 
the atmosphere. 
We find this nitrogen in the atmosphere in rain-water and 
in all kinds of soils, in the form of ammonia, as a product of 
the decay and putrefaction of preceding generations of ani- 
mals and vegetables. We find, likewise, that the proportion 
