LAB 
LABEL, in heraldry, a fillet usually 
placed in the middle aloug the chief of the 
eoat, without touching its extremities. Its 
breadth ought to be a ninth part of the 
chief. It is adorned witli pendants ; and 
when there are above three of these, the 
number must be specified in blazoning. 
This is a kind of addition to the arms of a 
second brother, to distinguish him from the 
first, and is esteemed the most honourable 
of all differences. 
Label, in law, a narrow slip of parch- 
ment hanging from a deed, writ, or other 
writing, in order to hold the appending 
seat. 
Label of a circumferentor, a long thin 
brass ruler, with a sight at one end, and a 
centre hole at the other ; chiefly used with a 
tangent line, to take altitudes. 
LABIAL letters, those pronounced chiefly 
by means of the lips. See Letter. 
LABIATED flowers, monopetalous flow- 
ers, consisting of a narrow tube, with a 
wide mouth, divided into two or more lips. 
See Botany. 
LABORATORY. A laboratory pro- 
perly fitted up with apparatus, is essentially 
necessary to a chemist whose objects lead 
him to make researches, experiments, and 
processes, upon all the different scales of 
operation. That great interest which the 
important science of chemistry has excited 
in all ranks of men, within the last thirty 
years, has rendered it easy to procure very 
complete sets of apparatus ; which at least 
in the metropolis may be collected in a 
short time, by those who like Boyle, Ca- 
vendish, Lavoisier, and other great men, 
are in possession of amplp means. But on 
the other hand, it is proper to remark, that 
many of our greatest discoverers, such as 
Scheele, Priestley, Berthollet, Wollaston, 
Dalton, Crawford, and a numerous set of 
eminent men, have from choice, or from mo- 
tives of prudence, made use of very simple, 
cheap, and small sized apparatus. It is un- 
doubtedly true that many operations can 
only be performed upon a scale of consi- 
derable magnitude, and that many facts of 
great value display themselves upon the 
extensive theatre of nature or in large ma- 
nufactories, which are either not seen, or 
require uncommon discernment to per- 
ceive them in the contracted space, and 
during the short time employed in the per- 
formance of a philosopliical experiment. 
But it is no less true that experiments upon 
a small scale do likewise possess their exclu- 
sive advantages. During tlie fusion and 
LAB 
combination of substances, in the whole no 
larger than a pepper-corn before the blow- 
pipe, the effects take place with rapidity, 
and many of them, such as the escape of 
gas by effervescence, the changes of colour, 
and transparency by differences in the heat 
applied, the manner of acquiring the solid 
state, &c. which cannot be seen in the fur- 
nace, are in the course of a few seconds 
remarked and ascertained. The saving of 
time is also an object of leading importance. 
The same considerations are likewise appli- 
cable to processes of fusion, or other appli- 
cations of heat in a small vessel, such as a 
tobacco-pipe, placed iu a common fire, 
urged by the bellows if necessary. Humid 
operations may also be very advantageously 
conducted by single drops of liquid, and 
small particles of solid bodies laid upon a 
glass i)late, or in the metallic spoon, and 
the lamp for distillations, and other works 
even upon a scale of some magnitude, has 
long been a favourite instrument with che- 
mists. Tliese will come under our notice as 
we proceed. 
Under our article Chemistry we have 
given a concise sketch or enumeration of 
the practical treatment of bodies, which 
leads us to point out the instruments in this 
place. 
For the mechanical division of bodies it 
is requisite the chemist should have the 
usual instruments for cutting, breaking, 
rasping, filing, or shaving. One or more 
mortars for pounding ; the best are made of 
hard pottery. A stone and muller for a 
levigating. A pair of rollers for laminating 
metals. A forge for many, or most of the 
purposes in which the blast heat of a small 
fire is required ; and various other tools and 
implements, not peculiar to chemistry. 
Messrs. Aikin, in their Chemical Dicti- 
onary, give the following list of implements 
and materials ; which, upon deliberate exa- 
mination, we highly approve : 
A gazometer, with the connecting tubes, 
blow pipe, &c. 
A bladder, or silk bag, with stop cock, 
fitting the above. 
A pneumatic water trough. 
A copper still with worm tub, the still 
fitting into the top of the Black’s furnace. 
.A blow-pipe, with spoon, &c. 
Lamps — an Argand, and others of com- 
mon construction, for oil and alcohol. 
An appaiatus for drying precipitates by 
steam. 
Scales and weights. 
Large and small iron stands for retorts, 
