LIGHT. 
680 
feveral of the articles we noticed in onr account of Mr. 
Winfor’s procefs ; as pitch, tar, afphaltum, and the ef- 
fential oil, or fpirit as he calls it, becaufe it may be ufed in- 
llead of that kind of fpirit known by the name of tar-fpi- 
rit in painting and japanning. Of thefe products he fent 
fpecimens to the Society of Arts, which are preferved in 
their repofitory ; and in his letter to the fecretary he pro¬ 
ceeds thus : “ I hope to lay before you, in a ffiort time, 
an account of the eftablifliment of a work that will be of 
fuch magnitude as will fupply this part of the country 
with the oil or fpirit in fufficient quantity to fuperfede the 
life of turpentine, &c. in japanning; and I do hope that 
in time works of the fame defcription will be eftablilhed 
through all StafFordfhire, whofe produds will fupply the 
place of a great portion of the fpirit ufed in the kingdom, 
while the pitch will be of fufficient quantity to form a 
great part of that article now ufed in the dock-yards. 
All I want is fupport from the great coal companies and 
matters, to ereft fufficient apparatus at the different works 
to preferve the tar at all the coke-furnaces, and proper 
means to feparate the fpirit from the tar. It would be a 
great faving to the nation, as in every cwt. of coal coked, 
there is loft by the prel’ent mode about four pound of tar, 
and the cokes are not half fo good as if they were coked 
in clofe veffels, to the exclufion of the atmofpheric air. 
I need not defcribe by drawings the manner of extract¬ 
ing the tar from pit-coal in clofe veffels, as that method 
is fo generally known ; it muft be clear to every one, that 
it is procured by diddling the coal. 
“ I have, as follows, defcribed the method I ufe in ex¬ 
tracting the fpirit from the tar, the procefs of which is fo 
Ample that every one mult underhand it. Fig. 8 is a 
feCticn of the furnaces, and one of the retorts, almolt 
any number of which may work in a line; the fame flue 
will do for all; only taking care, if any are not at work, 
to flop up the draught-hole which communicates with the 
flue. Thefe furnaces are built without bars, grates, or 
doors. A is the place where the fuel is put in to heat 
the retort G ; the fire lies under it, and the fmoke is car¬ 
ried off into the flue F. B is the aperture where the affies 
are raked out. G is a feCtion of the iron bafon, or lower 
part of the retort; the dark-ftiaded ftjuare part (hows the 
Apace the fire occupies, and the black fquare D the flue as 
it runs along the back of ail the line of furnaces, and 
enters the chimney R, as the arrows ffiow. I, Fig. 8 and 
9, (hows the upper part of the iron, earthen, or glafs, 
retort, fitted on the caff-iron bafon G. K, the receiver. 
By this mode of fetting the retorts, all the expenfe of 
bars, doors, frames, Sec. is faved, and a brilker draught of 
air is obtained, which may be flackened at pleafure by 
covering up in part, or wholly, the fire-place A with a 
brick. E, fig. 9, is a fquare iron plate with a circular 
hole in the centre, built on the top of the furnace. The 
caff-iron bafon of the retort G is made to the fize of the 
hole in the plate ; the moff convenient fize of the balon 
of the retort, I find, is about five or fix gallons, in the 
fhape of a deep pot, with a flanch or rim H round the 
edge of it; this pot or bafon of the retort is put into the 
iron plate E, and the flanch of the retort then relis on 
the plate E. I is the upper part of the retort without a 
bottom, made to reft and fit on the flanch of the caff-iron 
bafon G. K is the receiver, larger in the mouth than the 
nofe of the retort. To'begin the work, I fill, nearly, the 
iron bafon of the retort G with coal-tar; I then put on 
the upper part of the retort I, and make it air-tight with 
a little land thrown round it at the flanch H; the receiver 
X is put in its place, and a flow fire is put in at A, un¬ 
der the retort. The tar foon begins to boil flowly, or ra¬ 
ther fimmer; now, as foon as that begins, there riles from 
the tar a thick whitifh vapour, which fills the glafs retort; 
part becomes condeni'ed, and falls in drops from the fides 
of the retort into the tar again, while the purer fpirit 
riles into the neck, is condenfed, and keeps dripping down 
the neck into the receiver. This is the fpirit of the tar ; 
and with this fpirit that firlt ariles from the tar was the 
waiter japanned which I fent you. The reafon I chofe to 
have the receiver wider at the mouth confiderably than 
the nofe of the retort is, that there is a ffrong and very- 
volatile oily ammonia, that does not foon condenfe, but 
gets out of the receiver into the air the inftant it leaves 
the retort; and, though but in a very fniall quantity, (fo 
fmall that it is hardly pofiible to catch it,) yet will it im¬ 
pregnate the air, for a great diftance round, with its very 
penetrating fmell, while the fpirit keeps dropping into 
the receiver pure and feparate from the ammonia. The 
fpirit is very volatile, quite as much as, if not more than, 
the fpirit of turpentine, and foon evaporates if expofed 
to the air, which is a proof of its drying nature ; indeed, 
when ufed as a fubftitute for turpentine, it dries in the 
ftove quite as foon or fooner, and takes equally as beau¬ 
tiful a polilh. I fent you three fpecimens. No. 1. is what 
came off the tar firft. No. 2. is the fame diftilled a fe- 
cond time ; and the third fpecimen is the fecond re-dif- 
tilled again in a glafs retort; it there leaves a little pitchy 
refiduum, and comes over clear, as the farnple. Very 
little of the fpirit is loft in palling through thefe different 
ftages, if care is taken that the fire is flow, and the pro¬ 
cefs not hurried. When the fpirit is perfectly extra&ed. 
from the tar, there remains in the bafon of the retort 
that beautiful pitch, or afphaltum, which, when mixed 
with the fpirit, forms an ingredient for making the black 
varniffi ufed in japanning. If it is wifhed to ufe it as 
pitch, lefs fpirit muff not be extracted from it. I find 
that fix gallons of tar will produce, if care is taken, about 
two gallons or tw'o gallons and a half of fpirit. A great 
number of retorts may be kept working by a Angle man ; 
if we lay only one hundred, and only worked down in a 
day, they will produce 200 to 250 gallons of fpirit; fo 
that, by increafing the number, any quantity may be ob¬ 
tained. When the fpirit is ufed in the place of turpen¬ 
tine, the varnilh-maker ules it in the fame way, aiuj in 
the fame quantity, as there appears no manner of differ¬ 
ence in the ufe of it from fpirit of turpentine in the mak¬ 
ing of varnilh. When the afphaltum is ufed, it fupplies 
the place of real afphaltum, and in about the fame quan¬ 
tity.” 
To LIGHT, v. a. [from light, f] To kindle; to in¬ 
flame; to let on fire; to make flame.—Swinging coals 
about in the wire thoroughly lighted them. Boyle. 
Be witnefs, gods, and Itrike jocafta dead. 
If an immodeft thought, or low defire,. 
Inflam’d my breaft fince firft our loves were lighted. Dryd » 
To give light to ; to guide by light: 
All hopelefs, lafting flames! like thofe that burn 
To light the dead, and warm th’ unfruitful urn. Pope. 
To illuminate; to fill with light: 
The fun was fet, and vefper, to fupply 
His abfent beams, had lighted up the Iky. Dryden. 
Up is emphatically joined to light. —No fun was lighted up 
the world to view. Drydeh's Ovid.— [From the adjedive.j 
To lighten ; to eafe of a burthen : 
Land fome of our paffengers. 
And light this weary veil'd of her load. Fairy Queen. 
To LIGHT, v.n. [ licit , chance, Hut. prefer, lighted, im¬ 
properly light or lit.'} To happen to find; to fall upon by 
chance: it has on or upon before the thing found.—A 
weaker man may fome times light on notions which have 
efcaped a vviler. Watts on the Mind. —Truth, light upon this 
way, is of no more avail to us than error; for what'is fo 
taken up by us, may be falfe as well as true; and he has 
not done his duty, who has thus Humbled upon truth in 
his way to preferment. Locke. —Whofoever firlt lit on a 
parcel of that fubftance we call gold, could not rationally 
take the bulk and figure to depend on its real e He nee. 
Locke. 
Haply your eye fliall light upon feme toy 
You have delire to purthafe. Shakefpeare. 
