C H E M 
Th is lute is not expenfive, and is of very great lervice in 
the diftillation of acids, and of all corrofive bodies ; but 
it cannot be long prelerved, and mull, therefore, be frefh 
made every time. z. Take one pound of pulverized am¬ 
ber, melt it by a gentle fire in an iron veffel with an iron 
cover, containing one ounce and a half of turpentine. 
In the mean time boil on a feparate fire one pound of 
linfeed oil, and pour it hot, and while ftirred with an iron 
ladle, into the melted amber. In this manner we obtain 
a liquid of the confiftence of honey, which conftitutes the 
bails of common amber-varnifli. This liquid is then 
wrought with good dry clay into a palle, during which 
operation a fmall portion of expreffed nut-oil may be, 
added by way of dilution, and to prevent drying. This 
lute is much more expenfive than the former, but prefer¬ 
able in all its properties, It keeps for a very long time, 
and may be ufed twice or three times. 
In the diftillation of volatile alkali, ether, &c. there is 
no neceflity for ufing fat lute, we therefore employ one 
with much more convenience, which is thus prepared ; 
almonds finely powdered and lifted, or, which is prefer¬ 
able, flour of linfeed, is mixed with good ftarch, properly 
boiled, and formed into a hard pafte, which, in the ope¬ 
ration, may be foltened by fprinkling water upon it. 
This lute is very clean, and may be employed to great 
advantage in all operations where no corrofive bodies are 
treated} but it can be ufed only once, nor does it keep. 
It becomes ftill better and more firm, if a fmall portion of 
common glue be added to the ftarch. 
The application of the lute, in fecuring the junftures, 
is another important point; for, with the belt kind of 
lute, we fhall not be able to clofe a joining well, unlefs 
it be properly applied. But this operation is bell learned 
by praftical inftruftion and ufe; and the only rule which 
we can give in this place is, that the glafs is to be per¬ 
fectly clean and dry, that the lute mull be applied in 
fmall quantities only, and by degrees; and that the laft 
portion is to be properly combined with the portions ap¬ 
plied firft, by kneading. 
The communicating tubes are inferted in the necks of 
the bottles, by means of perforated corks. For this pur- 
pole a hole is firft bored through the cork, and filed with 
a round file, till the tube may be firmly fixed in it; the 
outfide of the cork is then filed with a coarfer file, till it 
fits exaftly the necks of the bottles. The cork lliould 
always go quite down into the neck, and not appear 
above it. Woulfe’s bottles and communicating tubes, 
joined to each other by corks alone, are reprelented by 
fig. z, and thofe which are luted, by fig. x. In joining 
the retort with the balloon, or the adopter, or an adopter 
with the bottles, lute alone is made ufe of, fome part of 
which Ihould be always preffed between the joinings of 
the veffels, for thefe mult never touch each other. 
As the junctures, defended either by fat or common 
lute, may be eafily difplaced by motion, and as fat lute 
is very liable to become foft, and to fink, when expofed 
to heat, it is effential, in nice operations, that the join¬ 
ings already luted Ihould be further l'ecured by wet blad¬ 
ders, or, which is ftill better, by ftrips of linen coated 
with white of egg and lime; thefe, by their compaCt- 
nefs, do not only tend to conned the joinings more clofe- 
ly, but they contribute very much to render the lute co¬ 
herent and firm. For this purpol'e, take ftrips of linen 
not too coarfe, of an inch wide, cut them into pieces as 
long as the coating of the lute upon the joinings is broad, 
dip them into frefli white of egg, take then out one after 
another, and rub them well in with powdered quicklime; 
this being done, put them tranfverlely upon the joining, 
and prefs them clofe and even upon the lute. In this 
manner the lute is covered with one, two, and, in greater 
operations, with three or four ftrips, which are then coated 
©nee more with white of egg; and, laftly, with quicklime. 
If, in a diftillation by Woulfe’s apparatus, the body, 
which is feparated, either on account of the mutual ac¬ 
tion of the fubftances with which it is in contaCl, or by 
the aCtion of heat, come over entirely in the form of gas 
foluble in water, the apparatus, in order to obtain the 
gas combined with water, in a liquid form, is to be con¬ 
nected in the following manner: The earthen glafs or 
retort, on the land-bath, water-bath, or the naked fire, is 
to be joined by means of the adopter, with the central 
neck of a Woulfe’s bottle with three necks. In one of 
the collateral necks of this bottle the tube of fafety is in¬ 
ferted in fuch a manner that it nearly touches the bot¬ 
tom. The other collateral neck is connected with a 
Woulfe’s bottle by means of a communicating tube with 
unequal ends, fo that the lliorter end only reaches into 
the neck of the bottle with three necks, whilft the other 
extends almoft to the bottom of the bottle with two 
necks; this lecond bottle is combined, in the fame man¬ 
ner, by means of the ufual communicating tube with un¬ 
equal ends, or, which is preferable, by means of the com¬ 
municating tube with the fmall capillary tube, with a 
third bottle with two necks, as Ihewn at fig. z. As much 
dhtilled water is introduced into the firft, or the bottle 
with three necks, previous to its being luted, as to allow 
the tube of fafety to be immerfed about half an inch. 
That quantity of water, which from experience we know 
to be requifite for the abforption of the gas which comes 
over, is then diftributed in equal proportions in the fe- 
cond and third bottles. The tube of fafety remains open, 
but thefhort capillary tube of the lecond communicating 
tube is luted in fuch a manner, that it may be opened 
with facility and fpeed. The ferond neck of the third 
bottle is either left open, orllightly Hopped by a cork. 
If a tubulated retort be made ufe of, the whole appa¬ 
ratus is luted, and the fubftances to be treated, or at iealt 
thofe which are to facilitate the developement of the gas, 
are introduced through the tubulure of the retort. On 
the contrary, the joinings between the retort, the adop¬ 
ter, and the firft bottle, remain open till the laft, but are 
luted the moment the bodies have been introduced through 
the neck of the retort. Now, if in confequence of the 
gradual application of heat, the fubftances contained ire 
the retort begin to aft upon each other, and difengage 
the gas, it mixes at firft with the common air confined 
in the retort, the firft bottle, and the firft communicating 
tube, which is thus condenfed, and preffes upon the whole 
furface of the water contained in the firft bottle, and up¬ 
on that of the water in the communicating tube of the 
fecond bottle. But, as the refiltance of the water in the 
fecond bottle is equal to the preffure of a column of wa¬ 
ter whofe height equals the fum of the heights of the wa¬ 
ter in the fecond and third bottles, and is confequently 
much greater than the refiltance of the water in the firft 
bottle, which at molt is equal to that of a column of wa¬ 
ter of one inch high, it follows, that the furface of the 
water in the immerfed end of the communicating tube 
in the fecond bottle remains unaltered, till, by the gra¬ 
dually increafed preffure, the water in the tube of fafety 
has ri'fen to a height which equals the fum of the heights 
of the water in the fecond and third bottles. If, for in- 
ftance, the water in the fecond and third bottles be four 
inches high, the water in the tube of fafety would rile 
eight inches, before the gas could be forced through the 
orifice of the immerced end of the firft communicating 
tube. 
As foon as the preffure of the water in the fecond bot¬ 
tle is overcome, the gas penetrates through the water, 
in the form of bubbles, into the fecond bottle, and from 
thence through the fecond communicating tube into the 
third bottle. During this tranfition, the gas is abforbed 
by the water, and the circumllances which promote the 
abforption are, i. the ftate of compreffure both of the 
gas and water; z. the minute divifion of the gas which 
paffes through the watef; 3. the cool temperature which 
is to be maintained in the refrigeratory veffels, in the 
manner reprelented by the plate; for the caloric, which 
is difengaged from the gas, frequently raifes the water 
to ebullition, 
Whe$ 
