60 HOW CROPS FEED. 
The Chenopodium vulvaria exhales from its foliage a 
body chemically related to ammonia, and that has been 
mistaken for it. This substance, known to the chemist as 
trimethylamine, is also contained in the flowers of Cra- 
tegus oxycantha, and is the cause of the detestable odor 
of these plants, which is that of putrid salt fish.* (Wicke, . 
Liebig’s Ann., 124, p. 338.) 
Certain fungi (toad-stools) emit trimethylamine, or some 
analogous compound. (Lehmann, Sachs’ Heperimental 
Physiologie der Pflanzen, p. 273, note.) 
It is not impossible that ammonia, also, may be exhaled 
from these plants, but we have as yet no proof that such 
is the case. 
Ammonia of the Atmospheric Waters.—The ammonia 
proper to the atmosphere has little effect upon plants 
through their foliage when they are sheltered from dew 
and rain, Such, at least, is the result of certain experi- 
ments, 
Boussingault (Agronomie, Chimie Agricole, et Physi- 
ologie, T. I, p. 141) made ten distinct trials on lupins, 
beans, oats, wheat, and cress. The seeds were sown in a 
soil, and the plants were watered with water both exempt 
from nitrogen. The plants were shielded by glazed cases 
from rain and dew, but had full access of air. The result 
of the ten experiments taken together was as follows: 
Weight of seeds.............. 4.965 grm’s. 
te “ dry harvest........ 18.730“ 
Nitrogen in harvest and soil.. .2499 “* 
sf seeds ..........46 2307 
Gain of nitrogen..... -0192 grm'’s = 1.6 per cent of the 
total quantity. 
When rains fall, or dews deposit upon the surface of the 
* Trimethylamine CsH9N = N (CH3)3 may be viewed as ammonia Ns, in 
which the three atoms of hydrogen are replaced by three atoms of methy\ 
CH3. It is a gas like ammonia, and has its pungency, but panied with the 
odor of stale fish. It is prepared from herring pickle, and used in medicine un- 
der the name propylamine, 
