| catheon Media. 
AMERICAN BLIGHT. 
from this their favourite intoxicating drink called 
pulque. “The plants are set about five or six 
feet asunder, and, in favourable situations, come 
into bloom in about ten years, at which period 
the valuable liquor they produce is to be pro- 
cured. As soon as the cultivator perceives the 
plant preparing to throw up its long flower-stem, 
he cuts out the leaves which form its centre, and 
hollows it out in the shape of a bowl, at the same 
time removing most of the other leaves, so that 
the whole sap destined for their supply flows to 
the great stem, and is received by the bowl- 
shaped cavity, into which it runs with such ra- 
pidity as to require to be emptied several times 
a-day, for a space of two months. The liquor, 
when collected, is placed in jars or skins; it un- 
dergoes a slight fermentation, which takes place 
in a few days, and is then fit for immediate drink- 
ing. Strangers prefer it when fresh, but the 
natives seldom use it till it has acquired a strong 
taste, and a disagreeable, fetid smell, denominated 
fuerte, when it is esteemed in high perfection. 
This is also called vino mercal; and resembles 
Scotch whiskey in colour and flavour; but it has 
a little more flavour of alcohol.” [ Bullock's Mex- 
wco.| The sap thus used by the Mexicans also 
| flows very copiously from the flowers in Great 
| Britain; it attracts myriads of bees, and may be 
collected in vessels; and, after being preserved 
for a few days in bottles, it is an excellent cor- 
dial, but it eventually becomes acidulous, fetid, 
| and disagreeable. — Loudon’s Encyclopedia of 
Plants. — Miller’s Gardener's Dictionary. — Bul- 
lock’s Mexico—Loudon’s Gardener's Magazine. 
AMERICAN BLIGHT. See Apuis. 
AMERICAN COWSLIP, —botanically Dode- 
A beautiful flowering plant, of 
the primrose tribe. It blooms from April till 
June, and afterwards dies down to the root till 
next spring. It thrives best in light, loamy, 
| moderately moist soil, in a shady situation; but 
| is not very easily kept. 
There is only one species. 
AMERICAN CRANBERRY. See Cranperry. 
AMERICAN CRESS, —botanically Barbarea 
Precox. An evergreen, herbaceous, kitchen-gar- 
den plant, of the cruciferous family. It is culti- 
vated in a number of gardens as a spring salad. 
The name of American cress is also given to the 
Virginian pepperwort, Lepidium Virginicum, a 
co-species of the common cress. 
AMERIMNUM. A small genus of tender, ever- 
green shrubs, of the pea tribe. They grow from 
ten to twelve feet high; and are natives of the 
West Indies and South America. The timber of 
one of the species has a fine greenish brown col- 
our, takes a good polish, and is imported to Great 
Britain under the name of American ebony. 
AMETHYSTEA. A pretty, blue-flowering, 
hardy annual plant, of the labiate tribe. It has 
a height of 18 inches, and is a native of Siberia. 
AMMOBIUM. A pretty, half-hardy, herba- 
ceous plant, of the composite family. It has 
some resemblance to the gnaphaliums or common 
AMMONIA. 
everlastings; and was recently introduced from 
New Holland. 
AMMONIA. The volatile alkali. It acts a 
very prominent and important part in most of 
the processes of agricultural chemistry, and ought 
to be thoroughly studied and well understood by 
every farmer. It does not naturally exist in a 
separate condition, and usually acts in combina- 
tion with acids in the form of salts, with water 
in the form of liquid, with atmospheric air and 
vapours in the form of gas, or with decayed ani- 
mal and vegetable matters in the form of farm- 
yard manure; yet it requires to be understood, 
not only in these combinations, but also as a 
separate substance. 
Ammonia is easily obtained from the sal am- 
moniac of commerce, or by the dry or destructive 
distillation of animal substances. It is a trans- 
parent, colourless, and consequently invisible gas ; 
and possesses elasticity and the other mechanical 
properties of the atmospheric air. It consists by 
weight of 0.125 of hydrogen and 1.75 of nitrogen ; 
or by atomic combination of three atoms of hy- 
drogen and one atom of nitrogen. It possesses 
an exceedingly pungent smell, and a very acrid 
taste ; and constitutes all the pungency and acrid- 
ity of the well-known spirits of hartshorn, sal- 
volatile, and smelling salts. It extinguishes com- 
bustion, and speedily kills any animal which is 
immersed in it. Water very rapidly condenses 
it; and can easily dissolve a quantity of it equal 
to one-third of its own weight, or 460 times its 
own bulk; and when brought into contact with 
a tubeful of it, water rushes into the tube with | 
explosive velocity. Ammonia, when in contact 
with other bodies, or when operated upon by 
various elementary substances and by light, heat, 
and electricity, is capable of undergoing an abso- 
lute multitude of transformations; and in con- 
sequence passes into such varied combinations, 
makes such great transitions, and assumes such | 
different and contrasted forms as no human mind 
but a chemist’s would suspect. When it is per- 
fectly dry and mixed with oxygen, the electric | 
spark explodes it, and converts it into water and | 
nitrogen, the hydrogen of the ammonia combin- | 
ing with the oxygen to form water, and the nitro- | 
gen of the ammonia being released and left free; 
yet if the oxygen with which the ammonia is > 
mixed be in excessive quantity, it acidifies a por- | 
tion of the nitrogen into nitrous acid. Ammonia | 
forms neutral compounds or soluble salts with — 
all the acids; and when in contact with certain | 
other substances, it completely loses its alkaline — 
character, and assumes exceedingly various and | 
In many of its combina- | 
tions and transformations, it is a healthful stim- | 
ulant; but, in others, it passes into the most | 
even opposite forms. 
virulent poisons. Pure ammonia, when trans- 
mitted through charcoal in combustion in a tube, 
forms prussic or hydrocyanic acid; and formate 
of ammonia, when under the influence of a high 
temperature, changes, without separation of its 
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