SO'S 
V o w 
As the theory of volcanoes is by no means 
ascertained, we have thought it better to pre- 
sent our readers with facts than speculations, 
and the narrations which we have selected 
contain the most Striking and best authenti- 
cated facts extant relative to these terrible 
phenomena. On these future philosophers 
may reflect, and possibly may elicit a more 
satisfactory explanation of them than any 
which has hitherto been presented to the 
public. 
YOLKAMERIA, a genus of the didy- 
uamia angiospermia class of plants, the co- 
rolla whereof consists of a ringent, single 
petal r the tube is cylindric, and twice the 
length of the cup ; the limb is divided into 
five" plain segments ; the fruit is a roundish 
bilocular capsule ; the seed is a single bilo- 
cular nut. There are eight species. 
VOL VOX, in zoology, a genus of ani- 
mals belonging to the order oi vermes intu- 
soria. The body is round, simple, and pel- 
lucid: There are ten species, all of which 
live in water. 
YOLUTA, in natural history, a genus of 
animals belonging to the class and order oi 
■vermes testacea. there are 144 species. 
The animals are of the slug kind ; the shell is 
unilocular and spiral; the aperture narrow 
and without a beak ; the columella plaited. 
VOLUTE, a spiral scroll, used in the Io- 
nic and composite capitals, whereof it makes 
the principal characteristic and ornament. 
See Architecture. 
VOMITING. See Medicine. 
VORTEX, in the Cartesian philosophy, is 
a system or collection of particles of matter 
moving the same way, and round the same 
axis. . 
VORTICELLA, a genus ofvermes infuso- 
ria. The generic character is, body con- 
tractile, naked, and furnished with ciliate ro- 
tatory organs. There are nearly sixty spe- 
cies of this genus. See Adams on the Mi- 
croscope. 
VOUCHER, a term of art, when the te 
meats of freehold or inheritance. He tl 
vouches is called voucher, and he that is vouc 
«d is called the vouchee. See Recovery. 
VOWEL, in grammar, a letter which affords 
a complete sound in itself. In our language they 
are six in number. 
The following views of the laxity with which 
»hc vowels are managed, and of their very great 
convertibility, in our language, have lately been 
viven. Their different sounds are designated by 
*he marks respectively used in these words t 
Vowels : — an, ably, ant; bed, be; it, high; 
on, so, off ; us, truth, music, full. 
Sounds 
U V u 
Expressed by 
Diphthongs : — oi \ ; out. 
Consonantal . — wit ; yon. 
I. 
Sounds 
Expressed by 
e, (i), ai, au, ia . 
e, i, ai, ao, au, ay, ea, (ee), ei, ey, oy 
(e), ai, au, (ea) 
a, (i), (u), ai, ay, ea, ei, eo, ey, ie 
i, y, ay, ea, ee, ei, eo, ey, ia, ie 
a, e, o, u, y, ea, ee, eo, ie, ui 
y, ai, ay, ei, ev, (ia), ie, ei, oy, ui, ye, eye 
5 l 
a, u, au, (aw), oa, ow 
aw, eo, ew, oa, oe, (oi), (oo), ou, ow, 
eau, (ewe), owe 
a, (ao), au, aw, (eo), oa, cm, awe 
(e), (i), o, (y), (ea;, oe, oo, ou _ 
o, eo, eu, ew, oe, oo, ou, ow, ue, ui, eew 
eo, eu, ew, ue, ui, eau, ewe, ieu, iew 
o, oo, ou 
oy, oie 
u, eo, ow 
o, u 
II. 
Letters and 
Combinations. 
Expressing 
, , , A 
e 
a, a, (a), (u), y 
i 
(a), a, (e), e, (u), y 
o 
i, u, u, u, ?v 
u 
(e), i, 6, ou, w 
y 
e, l, i, (u) 
ai 
Rj 2.) Uj Cj 1 
ao 
a, (6) 
au 
a, a, a, 6, O 
aw 
(6), 6, 6 
ay 
a, e, e, i 
ea 
" y (**) 
ee 
(a), e, t 
ei 
a, e, e, t 
eo 
6, e, i, 6, (6), u, u, ou 
eu 
Ci, u 
ew 
6, Ci, u 
ey 
a, e, e, i 
ia 
a, e, (i) 
ie 
6, e, i, i 
oa 
6, ft, ft 
oe 
Oy u, u 
oi 
1» (b) 
oo 
(6), u, u, u 
ou 
o, 6, u, u, 1 
ow 
6, ft, u, ou 
oy 
a, i, oi 
ue 
u, u 
ui- 
h h u. 
ye 
i 
awe 
5 
eau 
o, u 
eew 
ir 
ewe 
(6), a. 
eye 
i 
ieu 
u 
iew 
u 
oie 
oi 
owe 
6 
1 lie lllbldiiCCo liliiuucu mil m* / 
are found complete only with an r following 
them ; as e in clerk , referred to the sound of a 
in ant. 
UPUPA, in ornithology, a genus belong- 
ing to the order of picse. The beak is arcu- 
ated, convex, and something blunt ; the 
tongue is obtuse, triangular, entire, and very 
short; and the feet are fitted for walking. 
There are ten species, one of which, the 
epops, hoopoe, or dung-bird, is frequently 
seen in Britain. It may be readily distin- 
guished from all others that visit this island 
by its beautiful crest, which it can erect or 
depress at pleasure. It is in length fifteen 
inches ; the bill is black, two inches and a 
half long, slender, and incurvated ; the hides 
are hazel : the crest consists of a double row 
of feathers, the highest about two inches 
long ; the tips are black, their lower part of a 
pale orange colour : the neck is of a pale red- 
dish brown, the breast and belly white ; the 
lesser coverts of the wings are ol a- light 
U R A 
brown ; ihe back, scapulars, and wirgs, 
1 crossed with broad bars of white and black;, 
the rump is white ; the tail consists ot only 
ten feathers, white marked with black, in 
form of a crescent, the horns pointing to- 
wards the end of the feathers. The legs are 
short and black ; the exterior toe is closely 
united at the bottom to the middle toe. bee 
Plate Nat. Hist. tig. 413. 
According to Linnaeus, it takes its name 
from its note, which lias a sound similar t« 
the word ; or it may be derived from the 
French huDue. or “ crested:’ it breeds in 
Dr. Pallas affirms, that it 
dll UUUUJa^liUU uvimv; v*-- 
zaritsyn. Ovid says that Tereus was 
nanged into this bird. 
URANIA, a genus of the hexanckia me- 
nervnia class and order of plants. There is 
seeded. There is one species. 
URANIUM, a mineral found in Saxony, 
partly in a pure and partly in a mixed state: 
There are two varieties of these ; the first of 
a blackish colour, quite opaque, tolerably 
hard, and with a specific gravity of about 7.5. 
'Plie second is distinguished by a finer black 
colour, with here and there a reddish cast; 
bv a stronger lustre, not unlike that of pit- 
coal; by an inferior hardness; and by a shade 
of green, which tinges its black colour when 
it is reduced to powder. 
This fossil was called pechblende ; and mi- 
neralogists, misled by the name, had taken it 
for an ore of zinc, till the celebrated Werner, 
convinced from its texture, hardness, and 
specific gravity, that it was not a blende,, 
placed it among the ores ot -iron. After- 
wards he suspected that it contained tung- 
sten ; and this conjecture was seemingly con- 
firmed by the experiments ot some German 
mineralogists, published in the Miners’ Jour- 
nal. But Klapro-th, the most celebrated ana- 
lyst in Europe, examined this ore in 1789, 
and found that it consists chiefly of sulphur 
combined with a peculiar metal, to which he 
gave the name of uranium. 
Uranium is of a dark-grey colour; inter- 
nally it is- somewhat inclined to brown. 
Its malleability is unknown. Its hardness 
is about 6. It requires a stronger heat for fu- 
sion than manganese. Indeed Klaproth only 
obtained it in very small conglutinated me- 
tallic grains, forming all together a porous and 
spongy mass. Its specific gravity is 6.440. 
When exposed for some time to a red heat,, 
it suffers no change. By means of nitric acid, 
however, it may be converted into a yellow 
powder. This is the peroxide or yellow ox- 
ide of uranium, which seems to be composed 
of about 5§ parts of uranium and 44 of oxy- 
gen. This oxide is found native, mixed with 
the mineral above described. From 4 the ex- 
periments of Proust, we learn that this metal 
is capable of forming only two oxides, but no 
description of the protoxide has been pub- 
lished ; and the ore is so scarce that it is not 
every chemist who can gratify his curiosity by 
an examination of uranium. 
Uranium is. capable of combining with, sub 
