Z A M 
Z A N 
.can yet vote for knights of the shire, and do 
any other act where the law requires one 
that is probus et legalis homo. Below yeo- 
men are ranked tradesmen, artificers, and 
labourers. 2 Inst. 668. 
Yeoman' of the guard, one belonging to 
a sort of foot guards, who attend at the pa- 
lace. The yeomen were uniformly required 
to be six feet high. They are in number 100 
on constant duty, and 70 off duty. The one 
half carry arquebuses, and the other pertui- 
sans. Their attendance is confined to the 
-sovereign’s person,' both at home and abroad. 
They are clad after the manner of king 
Henry VIII. 
The yeomen of the guards were anciently 
250 men of the next rank, under gentry. 
This corps was first instituted by king Henry 
VII. anno 1466. 
YEST, Y east, or Barm, a head or scum, 
rising upon beer or ale, while working or fer- 
menting in the vat. See Fermentation. 
YEW. See Tax us. 
YOKE, in agriculture, a frame of wood, 
fitted over the necks of oxen, whereby they 
are coupled together, and harnessed to the 
plough. See Plough. 
It consists of several parts : as the yoke, 
properly so called, which is a thick piece of 
wood, lying over the neck ; the bow, which 
oompasses the neck about ; the stitchings 
and wreathings, which hold the bow fast in 
the yoke ; and the yoke-ring and ox-chain. 
The Romans made the enemies they sub- 
dued, pass under the yoke, which they called 
sub jugutn mitt ere, that is, they made them 
pass under a sort of furcae patibuiares, or gal- 
iows, consisting of a pike or other weapon, 
laid across two others, planted upright in the 
ground. 
YORK. In the county of York, only one 
pannel of 4S jurors shall be returned to serve 
on the grand jury at the assizes ; and at the 
quarter-sessions not above 40, either upon the 
grand jury or other service there. 7 and 8 
\V. III. c. 32. 
And no person having 150/. a year, shall 
be summoned to the sessions, but only per- 
sons less liable to bear the expence of a'ttend- 
inu at the assizes. 1 Anne, c. 13. 
lly stat. 4 W. III. c. 2. the inhabitants of 
the province of York, have power to dispose 
of their personal estate by will ; which before 
they had not, further than the testator’s own 
proportionable part, called the dead man’s or 
death’s part. For if the testator had a wife, 
and a child, or children, the wife should have 
one third, the child or children another third, 
and the remaining third was all that the tes- 
tator had to dispose of. If he had a wife and 
no child, then she should have one moiety, 
and the other moiety remained to him to 
dispose of by his testament ; so if he left a 
Z tke twenty-fourth and last letter of our 
} alphabet. 
In abbreviations this letter formerly stood 
as a mark for several sorts of weights ; some- 
times it signified an ounce and a half, and 
very frequently it stood for half an ounce; 
sometimes for the -eighth part of an ounce, or 
a dram troy weight ; and it has in earlier 
times been used to express the third part of 
child or children, and no wife. But if he 
had neither wife or child, he might dispose 
ot the whole. In case of intestacy, the same 
proportions continue to the wife and children 
to this day ; but the dead man’s part shall be 
distributed according to the stat. 22 and 23 
Car. II. c. 10 . commonly called the statute 
of distributions. 
YTTRIA.- Some time before 1788, Captain 
Arhenius discovered in the quarry of Ytterby 
in Sweden, a peculiar mineral different from 
all those described by mineralogists. Its co- 
lour is greenish-black, and its fracture like 
that of glass. It is magnetic, and generally 
too hard to be scratched by a knife. It is 
opaque, except in small pieces, when it 
transmits some yellow rays. Its specific 
gravity is 4.237. Professor Gadolin analysed 
this mineral in 1794, and found it to contain 
a new earth ; but though his analysis was 
published in the Stockholm Transactions for 
1794, and in Crell’s Annals for 1796, it was 
some time before it drew the attention of 
chemical mineralogists. The conclusions of 
Gadolin were confirmed by Ekeberg in 1707, 
who gave to the new earth the naifie of 
yttria. They were still farther confirmed 
and extended by Vauquelin in 1800, and like- 
wise by Klaproth about the same time ; and 
Ekeberg has published a new dissertation on 
the subject in the Swedish Transactions for 
1 802. We may therefore, consider the peculiar 
nature of yttria as sufficiently established. 
Hitherto yttria has been found only in the 
black mineral first analysed by Gadolin, and 
hence called gadolinite, in which it is com- 
bined with black oxide of iron and the earth 
called silica; and in yttrotantalite, which 
from the description of Ekeberg is a com- 
pound of tantalium and yttria. Both these 
minerals occur only in the quarry of Ytterby. 
From the first, which is the most common, 
the earth may be procured by treating the 
mineral reduced to powder with a mixture of 
nitric and muriatic acids, till it is completely 
decomposed ; then liltring the solution, pre- 
viously evaporated nearly to dryness, and 
then diluting it with water. By this process 
the silica is left behind. The liquid which 
passes through the filtre is to be evaporated 
to dryness, and the residue heated to redness 
for a considerable time in a close vessel, and 
then redissolved in water and filtred. What 
passes through the filtre is colourless; when 
treated with ammonia, pure yttria fills. 
^ ttria, thus procured, has the appearance 
of a fine white powder, and has neither taste 
nor smell. It is not melted by the applica- 
tion of heat. It has no action on vegetable- 
blues. It is much heavier than any of the 
other earths ; its specific gravity according 
to Ekeberg, being no less than 4.842. 
Z. 
an ounce, or eight scruples. ZZ were used 
by some ol the antient physicians to express 
myrrh, and at present they are often used to 
signify zinziber, or ginger. 
ZAFFRE, is theoxydeof cobalt, employed 
for painting pottery-ware and cobalt of a blue 
colour. See Cobalt. 
ZAMIA, a genus of the natural order of 
palnue. 1 he ament, is shobile-shaped, scales 
It is insoluble in water ; yet it is capable of 
retaining a great proportion of that liquid, as 
is the case with alumina. Klaproth ascer- 
tained, that one hundred parts of yttria pre- 
cipitated from muriatic acid by ammonia, 
and dried in a low temperature, lose thirty- 
one parts, or almost a third of their weight, 
when heated to redness in a crucible. Now 
this last consists of pure water alone. 
It is not soluble in pure alkalies; but it 
dissolves readily in carbonat of ammonia, 
and in ail the other alkaline carbonats. It 
combines with acids, and forms with them 
salts which have a sweet taste, and at the 
same time a certain degree of austerity. 
Some of these salts have a red colour. Yt- 
tria is the only earthy body known which 
has the property of forming coloured salts 
with acids. 
Yttria is not altered by light, nor is it like- 
ly that it combines with oxygen. From the 
experiments of Klaproth, it does not appear 
to combine readily with sulphur; nor is it 
likely that it unites with any of the other 
simple combustibles. 
We may take it for granted that it is not 
affected by azote; but if combines with mu- 
riatic acid, and forms a salt not capable of 
crystallizing. Its action on the metals and 
metallic oxides is unknown. 
YTTROTANTALITE, a mineral found 
in the same place with gadolinite. It is in 
small kidney-form masses of the size of a 
hazel-nut. Fracture granular, iron-grey, 
and of a metallic lustre. Hardness incon- 
siderable. May be scratched with a knife, 
and gives a grey-coloured powder. Not 
magnetic. Specific gravity 5.130. It is 
composed of the oxides of tantalium and 
iron united to yttria. 
YUCCA , Adam's needle, a genus of plants 
ol the class hexandria and order monogynia. 
The corolla is campanulate and patent, there 
is no style, the capsule is trilocular. There 
are four species, none of which are natives of 
Britain. All of them are exceedingly curious 
in their growth, and are therefore much cul- 
tivated in gardens. The Indians make a kind 
of bread from the roots of this plant. 
YUNX, in zoology, a genus of birds of the 
order picas. The bill is short, roundish, and 
pointed; the nostrils concave and naked ; the 
fongue very long and cylindric; there are 
two fore and two hind claws. There is only 
one species, the torquilla, wry-neck, which 
is a native of Europe, Asia, and Africa, and 
is often seen in Britain. It is ash-coloured 
above, with light black and brown strokes ; 
beneath light-brown, with black spots ; tail 
ash-colour, with four black bars ; weight 1 
oz ; i rides hazel ; length seven inches ; mi- 
grates. 
with pollen Underneath ; fern, ament, shobite- 
shaped with scales at each margin ; berry so- 
litary. There are five species. 
ZANNICHELLTA, horned pond-weed, 
a genus of the moncecia monandria class of 
plants, the male flower of which consists only 
of a single stamen ; it has neither calyx nor 
corolla. In the female flower the calyx is 
composed of a single kaf-; there is no co- 
