L I M 
L I M 
L I M 
'2 
* 
then is a simple substance, and limestone is 
composed of carbonic acid and lime. Heat 
separates the carbonic acid, and leaves the 
lime in a stale of purity. See Ain. 
When lime is exposed to the open air, it 
gradually attracts moisture, and falis to pow- 
der ; after which it soon becomes saturated 
with carbonic acid, and is again converted 
hito carbonat of lime or unburnt limestone. 
Water, at the common temperature of the 
atmosphere, dissolves about 0.002 parts of 
its weight of lime. This solution is called 
lime-water. It is limpid, has an acrid taste, 
and changes vegetable blue colours to green. 
One ounce troy of lime-water contains about 
one grain of lime. It is usually formed by 
throwing a quantity of lime in powder into 
pure water, allowing it to remain for some 
time in a close vessel, and then decanting 
the transparent solution from the undissolved 
lime. When lime-water is exposed to the 
air, a stony crust soon forms on its surface, 
composed of carbonat of lime ; when this 
crust is broken it falls to the bottom and 
another succeeds it; and in this manner the 
whole of the lime is soon precipitated, by 
absorbing carbonic acid from the air. 
Lime is not acted on by light, neither docs 
it combine with oxygen. Sulphur and phos- 
phorus are the only simple combustibles 
with which it unites. 
Sulphuret of lime may be formed by mix- 
ing its two component parts, reduced to a 
powder, and heating them in a crucible. 
'They undergo a commencement of fu- 
sion, and form an acrid taste. When it 
in exposed to the air, or moistened with wa- 
ter, its colour becoming greenish-yellow, 
sulphureted hydrogen is formed, .and the 
sulphuret is converted into a hydrogenated 
sulphuret, which exhales a very fetid odour 
of sulphureted hydrogen gas. This hvd; o- 
genated sulphuret may be formed also by 
boiling a mixture of lime and' sulphur in 
about ten times its weight of water, or by 
sprinkling quicklime with sulphur and then 
moistening it : the heat occasioned by the 
slacking of the lime is sufficient to form the 
combination. When this hydrogenated sul- 
phuret is exposed to the air, it imbibes oxy- 
ge«f; which combines at first with the hydro- 
gen, and afterwards with the sulphur, and 
converts the compound into sulphat of lime. 
Phosphuret of lime may be formed by the 
following process: put into the bottom of a 
glass tube, close at one end, one part of 
phosphorus; and, holding the tube horizon- 
tally, introduce live parts of lime in small 
lumps, so that they shall be about two inches 
above the phosphorus. Then place the tube 
horizontally among burning coals, so that 
the part of it which contains the lime may 
be made red-hot, vyhile the bottom of the 
tube containing the phosphorus remains cold. 
When the lime becomes red-hot, raise the 
tube, and draw it along the coals till that 
part of it which contains the phosphorus is 
exposed to a red heat. The phosphorus is 
immediately volatilized, and passing through 
the hot lime combines with it. During the 
combination the mass becomes of a glowing 
red heat, and a quantity of pbosphurated 
hydrogen gas is emitted, which takes lire 
when it comes into the air. 
Lime does not combine with azote ; but 
it unites readily with muriatic acid, and form's 
muriat of lime. It facilitates the oxidize- 
ment of several of the metals, and it com- 
bines with several of the metallic oxides, and 
forms salts which have not hitherto been 
examined, if we except the compounds winch 
it forms with the oxides of mercury and 
lead, which have been described by Ber- 
thollet. 
The red oxicle of mercury, boiled with 
lime-water, is partly dissolved, and the solu- 
tion yields by evaporation small transparent 
yellow crystals. This compound has been 
called by some mercuriat of lime. 
Lime-water also dissolves the red oxide 
of lead, and (still better) litharge. This so- 
lution, evaporated in a retort, gives very 
small transparent crystals, forming prismatic 
colours, and not more soluble in water than 
lime. It is decomposed by all the alkaline 
sulphats, and by sulphureted hydrogen gas. 
I he sulphuric and muriatic acids precipitate 
the lead. This compound blackens wool, the 
nails, the hair, and white of eggs; but it does 
not affect the colour of silk, the skin, the 
yolk of egg, nor animal oil. It is the lead 
which is precipitated on these coloured sub- 
stances in the state of oxide ; for ail acids 
can dissolve it. r i he simple mixture of lime 
and oxide of lead blackens these substances ; 
a proof that the salt is easily formed. 
Lime does not combine with alkalies. The 
affinities of lime are arranged by Bergman in 
the following order : 
Oxalic acid 
Sulphuric 
'Tartaric 
Succinic 
Phosphoric 
Saclactic 
Nitric 
Muriatic 
Suberic 
Fluoric 
Arsenic 
Lactic 
Citric 
Benzoic 
Sulphurous 
Acetic 
Boracic 
Carbonic 
Prussic 
One of the most important uses of lime is, 
in the formation of mortar a§ a cement in 
building. Mortar is composed of quicklime 
and sand reduced to a paste with water. 
When dry it becomes as hard as stone, and 
as durable ; and adhering very strongly to 
(he surfaces ot the stones which it is employ- 
ed to cement, the whole wall becomes In 
fact nothing else than one single stone. But 
this effect is produced very imperfectly un- 
less the mortar is very well prepared. 
The lime ought to be pure, completely 
free from carbonic acid, and in the state of a 
very tine powder: the sand should be free 
from clay, and partly in the state of line 
sand, partly in that of gravel : the water 
should be pure ; and if previously saturated 
with lime, so much the better. The best 
proportions, according to the experiments 
of Dr. Higgins, are three parts of tine sand, 
four parts of coarse sand, one part of quick- 
lime recently slacked, and as little water as 
possible. 
The stony consistence which mortar ac- 
quires, is owing partly to the absorption of 
carbonic acid, but principally to the combi- 
nation of part of tne water with the lime. 
This last circumstance is the reason that it 
to common mortar one-fourth part pi time. 
reduced to powder without being slacked, 
is added, the mortar, when dry, acquires 
much greater solidity than it otherwise 
would do. This was first proposed by Lo - 
riot ; and a number of experiments were 
afterwards made by Morveuu. '] he pro- 
portions which this philosopher found to 
answer best are the following : 
Fine sand - - 0.3 
Cement of well-baked bricks 0.3 
Slacked lime - - 0.3 
Unslacked lime - - 0 2 
1.0 
The same advantages may be attained by 
using as little water as possible in slacking A 
the lime. 
Higgins found that the addition of burnt 
bones improved mortar by giving it tena- 
city, and rendering it less apt to crack in 
drying; but they ought never to exceed 
one-fourth of the lime employed. 
When a little manganese is added to mor- 
tar, it acquires the impoitant property of 
(hardening under water ; so that it mav be 
employee! in constructing those edifices 
which are constantly exposed to the action 
of water. Limestone is often combined 
with manganese : in that case it becomes 
brown by calcination. 
LIMESTONE. See Salts, calcareous. 
Limestone, primitive and secondary. See 
Rocks. 
LIMEUM, a genus of the class and order 
heptandria digynia. T he cal. is live-leaved ; 
pet. live, equal ; caps, globular, two-celled. 
'There are three species, herbaceous plants 
of the Cape. 
LIMIT, in a restrained sense, is used by 
mathematicians for a determinate quantity 
to which a variable one coni nually ap- 
proaches; in which sense the circle may be 
said to be the limit of its circumscribed and 
inscribed polygons. In algebra, the term 
limits is applied to two quantities, one of 
which is greater, and the other less, than 
another quantity; and in this sense it is used 
in speaking of the limits of equations, where- 
by their solution is much facilitated. 
Let any equation, as a- 1 — px 2 x qx — r — 0 
be proposed ; and transform it into the follow- 
ing equation: 
y 1 -(- Sey 2 -|- 3 e l y -|~ e* 
— py 2 — ~P e y — P*~ 
+ ?y + <i e 
— r 
where the values of y arc less than the respec- 
tive values of x, by the difference e. If Toll 
suppose e to be taken such as to make alBthe 
co-efficients of the equation of y positive, viz. 
T pr qc — r, 3<r — i pc -j- rj, 3* — p ; then 
there being no variation of the signs in the 
equation, all the values of y must be negative ; 
and consequently the quantity e, by which the 
values of x are diminished, must be greater 
than the greatest positive value of v .• and, con- 
sequently, must be the limit of the roots of the 
equation a- 3 — , p x 2 -j- qx — r — 0. 
It is sufficient, therefore, in order to find the 
limit, to enquire what quantity -substituted for 
a, in each of these expressions .v — px 1 _j_ qx 
— r, 3a- 2 — ‘2pv y, 3 a- — p, will give them 
all positive ; for the quantity will be the limit re- 
quired. 
Having found the limit that surpasses the 
greatest positive root, call it m. And if you 
assume y ~m — x, and for x substitute m — y, 
