LABORATORY. 
Catechu. 
Isinglas!. 
Olive-oil. 
Linseed-oil, drying. 
Oil of Turpentine. 
Black flux. 
Distilled water, in great plenty. 
The most convenient arrangement for a 
laboratory where space is not wanted, 
seems to be that of two rooms, and a shed 
or apartment which can be thrown open to 
communicate with the air. The first may 
contain the books of register, of practical 
reference, together with the more delicate 
philosophical and chemical instruments, 
products, and preparations. The second 
may be provided wdth the work-bench, 
hammers, anvil, vice, and other tools, and 
the different furnaces ; and the shed may 
be devoted to experiments of danger, such 
as arise from explosions, noxious vapours, 
and the breaking of vessels. It will be 
most convenient that these should be upon 
the ground floor, to secure the advantage 
of a ready supply of water or fuel, and 
other articles of heavy consumption. The 
first of which articles may be largely want- 
ed, in case of accidental combustion, as welt 
as on common occasions. But it is likewise 
necessary that the place should be diy, in 
order that labels may be preserved, and 
other inconveniences avoided. This is the 
principal general argument, in favour of a 
laboratory above the ground floor. 
It would carry us too far beyond the li- 
mits of our work if we were to give draw- 
ings and descriptions of the great variety of 
vessels, furnaces, and apparatus, which 
have been contrived for general and parti- 
cular purposes of chemistry ; and many of 
the culinary and domestic vessels may also 
be applied in experimental chemistry. We 
shall tlierefore confine ourselves to a few 
of the most simple and useful. 
In Plate Laboratory, fig, 1 , represents 
a retort, a, and receiver, b. These ves- 
sels are used for distillation. The sub- 
ject is put into the belly of the retort, a, 
and exposed to heat, and the volatile pro- 
ducts pass over into the receiver, b, which 
may be kept cool by the application of wet 
cloths, or by’ immersion in cold water, or 
otherwise, if needful. The place of Junc- 
tion is secured either by fitting the necks 
together by grinding, or by means of a lute, 
which see farther on. At c, in the receiver, 
is a neck closed by a stopper, Receivers or 
retorts, with this additional neck, are said 
to be tubulated. Fig. 2, is an alembic, of 
which a is the body, b the head, and c the 
neck. Generally speaking, this is not a 
very useful instrument. In large distilla- 
tions an alembic or still is used, but the 
condensation is effected by a spiral pipe, 
called the worm, which passes through a 
tub of cold w'ater. In the use of the alem- 
bic, fig. 2, the beak is inserted into a re- 
ceiver. 'When the volatile product of a 
body exposed to be dried, or to undergo 
evaporation by heat, is not required to be 
preserved, the process is performed in an 
open vessel. 
The application of heat to vessels is made 
either by naked fire, or by the intervention 
of some heated substance, which is then 
called a bath. Chemical baths are made of 
sand, or of melted lead, or the fusible metal, 
or of brine, and very frequently, of water. 
The evaporable liquids form a bath which 
cannot be heated beyond their re.spective 
boiling points; and the other baths, the 
most common of which is that of sand, are 
chiefly valuable for giving a regular heat 
without sudden changes. 
This last purpose is effected likewise 
with glass vessels, by coating them with a 
lute. 
A very great number of furnaces have 
been constructed for chemical and manu- 
facturing purposes, for which we must ne- 
cessarily refer to the extensive works ap- 
propriated to these objects. The operative 
chemist may, have occasion for them of dif- 
ferent sizes and figures. A great deal may 
be done with the common German stove, 
and with small furnaces made out of black- 
lead pots. But, in general, tlie philosophi- 
cal chemist w'ill be well accommodated 
with one good furnace, convertible to dif- 
ferent uses; and out of many such we 
select that of Dr. Black, for its simplicity 
and efficacy, as described in his lectures. 
Plate-iron is by far the best material for 
the outside of/an experimental furnace: but, 
as its metal communicates heat very fast, this 
must be cut off by a proper lute lining. 
The Doctor so far succeeded in this respect, 
that his furnace, though only two inches 
thick in the middle, will not scorch paper 
applied to its outside^ when it is melting 
iron within. He adopted the simplest rec- 
tilineal shapes, because workmen find great 
difficulty in executing curved and uncom- 
mon forms; and notone of a score of them 
will do it with accuracy. Indeed, those 
highly praised forms seemed to him of very 
little importance in most cases. 
The body, or fire-place, is the only part 
of tins furnace that requires description ; 
the ash pit, with its door and registers and 
