M E T 
M E T 
M E T 
r6n 
tion. They are greenhouse plants, and are 
propagated by cuttings ot their stalks aiul 
branches. 
MESENTERY. Sec Anatomy. 
MESNE, he wh® is lord of a manor, and 
so hasteuants holding of him, yet himself 
■holds of a superior lord. 15 Via. Abr. 
MESNE PROCESS, is an intermediate 
process, which issues pending the suit, upon 
some collateral interlocutory matter, as to 
summon juries, witnesses, and the. like; 
sometimes it is put in contradistinction to 
final process, or process of execution; and 
then it signifies all such process as intervenes 
between the beginning and end of a suit. 3 
Black. 279. 
MESPILUS, the medlar; a genus of the 
pentagynia order, in the icosandria class of 
plants ;' and in the natural method ranking 
under the 36th order, pomaceae. The calyx 
is quinquefid; the petals are five ; the berry 
is inferior and pentaspermous. 
There are nine species, the principal of 
which are, 1. The Gertnanica, German mes- 
pilus, or common medlar, rises with a de- 
formed tree-stem, branching irregularly 15 
or 20 feet high; spear-shaped leaves, and 
brown fruit, the size of middling apples, 
which ripen in October, but are not eatable 
till beginning to decay. The varieties are, 
common great German medlar ; smaller 
Nottingham medlar; spear-shaped Italian 
medlar. 2. The arbutiiolia, arbutus-leaved 
mespilus, has a small, roundish, purple fruit, 
like haws. 3. T he amelanchier, or shrubby 
medlar, with black fruit. 4. The chamae- 
mespilus, or dwarf medlar, commonly called 
bastard quince, has small red fruit. 5. The 
f cotoneaster, commonly called dwarf quince, 
with small roundish bright-red fruit. 6. The 
| C'adancnsis, Canada snowy mespilus, with 
small, purplish fruit, like haws. 7. I he 
pyracantha, or evergreen thorn, rises with a 
shrubby, spinous stein, branching diffusely 
12 or 1 4 feet high, all the shoots terminated 
by numerous clusters of whitish flowers; suc- 
ceeded by large bunches of beautiful red 
berries, remaining all winter, and exhibiting 
a very ornamental appearance. 
MESSENGERS, are certain officers 
; chiefly employed under the direction of the 
secretaries of state, and always in readiness 
to be sent with all kinds of dispatches foreign 
and domestic. They also, by virtue of the 
secretaries’ warrants, take up persons for high 
I 1 treason, or other offences against the state. 
The prisoners they apprehend are usually 
kept at their own houses, for each of which 
they are allowed 6v. 8 "d. per day, by the go- 
vernment: and when they are sent abroad, 
they have a stated allowance for their jour- 
ET- 
METALS may be considered as the great 
instruments of afl our improvements: 'with- 
- out them, many of the arts and sciences 
| could hardly have existed. So sensible were 
the antients of their great importance,. that 
I they raised those persons who first disco- 
S verefl the art of working them to the rank of 
deities. In chemistry, they have always filled 
a conspicuous station: at one period the 
[ whole science was confined to them ; and it 
| may be said to have owed its very existence 
‘ to a rage for making and transmuting metals. 
I. One of the most conspicuous properties 
of the metals is a particular brilliancy which 
they possess, and which lias been called the 
metallic lustre. 'I here are other bodies in- 
deed (mica for instance) which apparently 
possess this peculiar lustre, but in them it is 
confined to the surface, and accordingly dis- 
appears when they are scratched, whereas it 
pervades every part of the metals. This 
lustre is occasioned by their reflecting much 
more light than any other bodies ; a property 
which seems to depend partly on the close- 
ness of their texture. This renders them pe- 
culiarly proper for mirrors, of which they al- 
ways form the basis. 
us to give the metallic bodies any form we 
think proper, and thus renders it easy for us 
to convert them into the various instruments 
for which we have occasion.. All metals do 
not possess this property; but it is remark- 
able that almost all those which were known 
to the antients have it. Heat increases this 
property considerably. Metals become 
harder and denser by being hammered. 
9. Another property, which is also wanting 
in many of the metals, is ductility; by which 
we mean the capacity of being drawn out 
into wire, by being forced through holes of 
various diameters. 
2. They are perfectly opaque, or imper- 
vious to ltght, even after they have been re- 
duced to very thin plates. Silver leaf, for 
instance, T _J__ of an inch thick, does not 
permit the smallest ray of light to pass through 
it. Gold, however, when very thin, is not 
absolutely opaque: for gold leaf, -^Voo 
of an inch thick, when held between the eve 
and the light, appears of a lively green; and 
must therefore, as Newton first remarked, 
transmit the green-coloured rays. It is not 
improbable that all other metals, as the same 
philosopher supposed, would also transmit 
‘light if they could be reduced to a proper 
degree of thinness. It is to this opacity that 
a part of the excellence of the metals, as 
mirrors, is owing; their brilliancy alone 
would not qualify them for that purpose. 
3. They may be melted by the applica- { 
tion of heat, and even then still retain their j 
opacity. This property enables us to cast j 
them in moulds, and then to give them any | 
shape we please. In this manner many ele- ! 
gant iron utensils are formed. Different me- j 
tals differ exceedingly from each other in fu- j 
sibility. Mercury is so very fusible, that it | 
is always fluid at the ordinary temperature ; 
of the atmosphere; while other metals, as i 
platinum, cannot be melted except by the 1 
most violent heat which it is possible to pro- 
duce. , 
4. Their specific gravity is much greater ; 
than that of any other body at present 
known. Antimony, one of the lightest of 
them, is more than six times heavier than 
water; and the specific gravity pf platinum, j 
the heaviest of all the metals, is 23.- This I 
great density, no doubt, contributes con- . 
siclerably to the reflection of that great quan- 
tity of light which constitutes the metallic | 
lustre. 
5. They are the best conductors of elec- ! 
tricitv of all the bodies hitherto tried. 
6. None of the metals are very hard; but j 
some of them may be hardened by art to | 
such a degree as to exceed the hardness of j 
almost all other bodies, lienee the liume- j 
rous cutting instruments which the moderns ; 
make of steel, and which the antients made | 
of a combination of copper and tin. 
7. The elasticity of the metals depends 
upon their hardness; and it may be increased 
by the same process by which their hardness i 
is increased. Thus the steel of which the ba- 
lance-springs of watches are made, is almost 
perfectly elastic, though iron in its natural 
state possesses but little elasticity. 
8. But one of their most important. pro- 
perties is malleability, by which is meant the 
capacity of being extended and flattened 
when struck with a hammer. This pro- 
perty, which is peculiar to metals, enables 
X 2 
10. Ductility depends, in some measure, 
on another property which metals possess, 
namely, tenacity; by which is meant the 
power which a metallic wire of a given di- 
ameter has of resisting, without breaking, the 
action of a weight suspended from its extre- 
mity. Metals differ exceedingly from each, 
other in their tenacity. An iron wire, for 
instance, -J^th of an inch in diameter, will 
support, without breaking, about 5001b. 
weight ; whereas a lead wire, of the same di- 
ameter, will not support above 29lb. 
11. When exposed to the action of heat 
and air, most of the metals lose their lustre, 
and are converted into earthy-like powders 
of different colours and properties, according 
to the metal and the degree oi heat employed. 
Several of the metals even take lire when ex- 
posed to a strong heat; and after combustion 
the residuum is found to be the very same 
earthy-like substance. 
12. If any of these calces, as they are 
called, is mixed with charcoal-powder, and 
exposed to a strong heat in a proper vessel, 
it is changed again to the metal from whiclv 
it was produced. This fact, is easily ex- 
plained on the principles of modern chemist- 
ry ; the calx is the metal combined with oxy- 
gen, or an oxide, in modern language, and 
by beating it with charcoal, which has a 
stronger attraction for oxygen, th t substance 
is taken from the metal, and it is brought 
again to the metallic state. The oxygen in 
this process, uniting with the charcoal, forms 
carbonic acid gas. 
'Fhe words calx and calcination, then, are 
evidently improper, as they convey false 
ideas; philosophers therefore now employ, 
instead of them, the words oxide and oxi- 
dizemenf, which were invented by the 
French chemists. A metallic oxide signifies 
a metal united with oxygen ; and oxidize- 
ment implies fhe act of that union. 
13. Metals, then, ai e ail capable of com- 
bining with oxygen; and this combination is 
sometimes accompanied by combustion, and 
sometimes not. 'I he new compounds formed 
are calied metallic oxides, and in some cases 
metallic acids. These were formerly distin- 
guished from each other by their colour. 
One of the oxides, for instance, was called 
black oxide, an ,ther was termed red oxide; 
but it is now known that the same oxide is 
capable of assuming different colours ac- 
cording to circumstances. The mode of 
naming them from their colour, therefore, 
wants precision, and is apt to mislead; es- 
pecially as there occur different examples of 
two distinct oxides of the same metal having 
the same colour. 
As it is absolutely necessary to be able to 
distinguish the different oxides of the same 
