ALL 
ALK 
and when broken, and examined by a mi- 
croscope, they present a number of facettes 
with the appearance of crystallization: at 
40° Fahrenheit they are soft, and can 
scarcely be discriminated but by their gra- 
vity from globules of mercury ; at 60° they 
are fluid, and at the small heat of 100° vo- 
latile. When exposed to the atmosphere, 
they rapidly imbibe oxygen, and reassume 
the alkaline character. In distilled naptha 
they may be preserved four or five days, but 
if exposed to the atmosphere, they almost 
instantly become iccrusted with a coat of 
alkali: the incrustation may be removed, 
and the reduced globule will remain, either 
in naptha, or otherwise separated from all 
contact with oxygen. See Bitumen. 
One part of the base of alkali and two 
of mercury, estimated by bulk, form an 
amalgam, which when applied in the cir- 
cle of a galvanic battery, producing an in- 
tense heat, to iron, silver, gold, or platina, 
immediately dissolved them, and converted 
them into oxides, in which process alkali 
was regenerated. Glass, as well as all other 
metallic bodies, was also dissolved by the 
application of this substance : the base of 
the alkali seizing the oxygen of the manga- 
nese and of the minium, potash was rege- 
nerated. One of these globules placed on 
a piece of ice dissolved it, and burnt with a 
bright flame, giving out an intense heat. 
Potash was found in the product of the 
dissolved ice. Nearly the same effects fol- 
lowed, when a globule was thrown into wa- 
ter : in both cases a great quantity of hy- 
drogen was rapidly liberated. When laid 
on a piece of moistened turmeric paper, 
the globule seemed instantly to acquire an 
intense heat ; but so rapid was its move- 
ment in quest of the moisture, that no part 
of the paper was burnt, only an intense 
deep red stain marked the course it fol- 
lowed, and showed a reproduction of al- 
kali. The specific gravity of the base of 
soda is as seven to ten of water : it is fixed 
in a temperature of about 150°, and fluid 
at 180°. Mr. Davy next tried its effects on 
the phosphates, phosphurets, and many 
other salts of the first and second degree of 
oxydizement, all of which it decomposed, 
seizing their oxygen, and reassuming its 
alkaline qualities. From many experiments 
it appears, that 100 parts of pot-ash con- 
tain 15 of oxygen and 85 of an inflamma- 
ble base, and that the same quantity of 
soda contains 20 of oxygen and 80 base. 
This ingenious chemist, after a great num- 
ber of complex experiments, in which he 
was assisted by Messrs. Pepys and Allen, 
ascertained that oxygen is also an essential 
ingredient in ammonia ; of which 100 grains 
appeared to yield 20 of oxygen. Mr. Davy 
has also found that oxygen is one of the 
constituent principles of the muriatic and 
fluoric acids, and likewise of the earths ba- 
rytes and strontites. See Chemistry, 
Potash, and Soda. 
ALLAMANDA, in botany, a genus of 
the Pentandria Monogynia class and order : 
corolla twisted ; capsule lens-form, erect, 
echinate, one-celled, two-valved, many- 
seeded. One species, viz. cathartica, a 
climbing plant, found in Guiana. The in- 
fusion of its leaves is used in the cholic. 
ALLANTOIS, or Allantoides, in com- 
parative anatomy, a vesicle investing the 
fretus of several animals, as cows, sheep, 
goats, &c. and filled with an urinous liquor 
conveyed thither from the urachus. 
ALLEGIANCE, is the lawful duty from 
the subject to the sovereign ; and is either 
natural, as every subject born ought to 
pay ; acquired, where a man is naturalized ; 
local, which a man ought to pay who comes 
under the dominion of the king. 
ALLEGORA", in matters of literature, 
a mode or species of writing, wherein some- 
thing else is signified than the words in their 
literal meaning express. An allegory may 
be considered as a series or chain of meta- 
phors, continued through a whole discourse. 
For example, when the prophets represent 
the Jews under the allegory of a vine 
planted, cultivated and watered by the 
hand of God, which instead of producing 
good fruit, brings forth verjuice and soul- 
grapes. 
ALLEGRO, in music, an Italian word 
denoting that the part is to be played in a 
sprightly, brisk, lively, and gay manner. 
Allegros move swifter in triple than in com- 
mon time. Sometimes in conjunction with 
another word, placed at the beginning of 
compositions, it is intended to rouze and 
stimulate the more violent passions. 
ALLEMANDE, in music, a slow air or 
melody in common time of four crotchets 
in a bar. A species of composition, sup- 
posed from its name to be of German ori- 
gin. It is found in Handel’s harpsichord 
lessons, and other works of about that date ; 
but as a sonata movement it is now obso- 
lete. The dance known by this name is 
still used in Germany and Switzerland, and 
is written in common time of two crotchets 
in bar. 
ALLEN (Thomas) a celebrated mathe 
