LABORATORY, 
one and a half or two of turpentine, and 
keep it for use. When used, soften and 
make it tongb, by warming and working 
between the fingers; tlicn put it on the 
joint in little rolls, and make it close ; and, 
lastly, cover it with slips of wet bladder 
laced with pack-thread. But, if the joint is 
liable to be warmed, or heated during the 
operation, you must take fat lute. This is 
made of raw pipe-clay and linseed oil, 
beaten together vei-y hard, to the consis- 
tence of a stiff adhesive paste. 
Of the second kind of lutes, called the 
fire-lutes, a great variety have been propos- 
ed, and some of them compositions of many 
ingredients, but none are equal, or superior, 
to clay and sand; viz. sand S, or 4, or 
6, or 6, to clay 1. These are for luting 
vessels together, and for coatings. But in 
lining furnaces, Dr. Black used a double 
lining ; first, a charcoal-lute ; secondly, a 
fire-lute. 
He found that a layer of powdered char- 
coal, beaten up, or kneaded, witli as little 
water as will give its particles adhesion 
enough to attach itself to the metal sides of 
the furnace, by means of cautious beating, 
forms a firm stratum, which is the most im- 
perfect conductor of heat of all that he had 
tried. When this layer of charcoal is de- 
fended from the action of the air by a layer 
of fire-lute, composed of one part of fine 
clay, and three or four parts of sand, care- 
fully put on, and consolidated by gently 
beating it from day to day, till it no longer 
receives an impression from the mallet ; it 
will last as long as any part of the furnace. 
Its durability will be greatly improved, 
without much change in its conducting 
power, by using, instead of pure water, 
water made muddy by about one-twentieth 
of pipe-clay. If finely powdered chai’coal 
be kneaded with one-fifth of pipe-clay, it 
may be kneaded and formed into any shape, 
and will be so impervious to heat that a bit 
of it may be held in the fingers within an 
inch of where it is red hot. Such a com- 
position is, therefore, very proper for the 
doors of furnaces, and for stopples for such 
apertures as must be frequently opened 
and shut. 
Fig. 4, represents an Argand’s lamp capa- 
ble of being adjusted at different heights, 
by a sliding socket, on a stem or rod. 
Another similar socket is seen above, into 
which a ring of wire is inserted for support- 
ing the retort, a, at any required distance 
above the flame. A third socket may be 
added, still higher upon the stem, for sup- 
porting another wire, which will afford the 
means of steadying an alembic, or any other 
apparatus, by a string or small flexible wire 
answering the same purpose. This is a 
very convenient method of disposing vessels 
for the lamp heat, upon a small or moderate 
scale, for distillations, sublimation, evapo- 
ration, drying, and the like. A small sand- 
bath may be placed, when needful, in the 
wire above the flame : 6 is an intermediate 
Condensing vessel, called a quilled receiver, 
which conveys the condensed product into 
a bottle, c. The rod which supports b shows 
how useful these instruments are in their 
various applications. 
The condensation of vapours after distilla- 
tion, and the transmission of gases, which 
may arise along with them to their recep- 
tacles, has been very well and scientifically 
effected by the late Mr. Woulfe, in an ap- 
paratus of bottles which is distinguished by 
his name. The original contrivance will be 
easily understood by description, and in- 
stead of a drawing of that arrangement of 
vessels, we shall give one of the most sim- 
ple, safe, and convenient of all the improve- 
ments which have since been made in it ; 
namely, that contrived by Dr. Hamilton, 
and figured at the end of his “ Translation 
of Berthollet on Dying.” Suppose the retort 
and receiver, (fig. 1.) or any other distilla- 
tory apparatus, to have a communication 
from the upper parts of the receiver, a, at 
c by a tube leading into a bottle having 
three necks, and partly filled with water, 
beneath the surface of which the said tube, 
after passing this, an air-tight cork was 
plunged. Another of the necks of the bot- 
tle is provided with an upright open tube, 
also passing a cork and plunged in the 
water in order that air may enter in case of 
absorption, or the liquid may rise a little in 
it, in case of pressure from within. The 
third neck of the bottle affords a communi- 
cation by means of a tube with another 
two necked bottle, fitted up in all respects 
in the same manner as the bottle communi- 
cating with e. And in this manner we may 
conceive a series of three or more bottles, 
the last of which may communicate with a 
pneumatic apparatus which is to receive 
the incondensable gas. This system of bot- 
tles and tubes is sometimes fitted together 
by grinding, and sometimes made secure 
by lutes ; but in most constructions, though 
the advantages are very considerable, the 
apparatus is difficult to be put together, and 
easily deranged or injured. 
Fig. 5, represents Dr. Hamilton’s appa- 
