1809.] 
order to purify it, you must first put it 
into hair cloths, and, with an won plate 
between each clach,. to the number of 
half a dozen, or more, submit it to the 
action of an iron screw-press; and, as 
the oil does not separate very readily, 
it will in general be necessary to let your 
cakes of sperm be pressed ¢hree different 
times. The third time your cakes will 
become so dry that you may break thei 
in small pieces with little trouble, and 
then you are to put them ina hottle 
containing one-third water, and two- 
thirds cake. Let your fire be raised 
sufficiently under the furnace to melt the 
cake, which it will do before the water 
begins to boil: after which, boil the 
whole together for about half an hour, 
taking off, daring the boiling, what scam 
and other extraneous bodies rise to the 
top; then let the whole be dipped out 
into a tub, or other cooler, sufliciently 
large to receive it. After it-is) com- 
pletely cold, take off the cake of sperma 
ceti, which will be on the top of the 
water, and cut it into pieces... E will 
suppose, for example, that your cake 
weighs one hundred weight; in this case 
it will be necessary that you should have 
a furnace, or rather a moveable kettle, 
around which you can move with ease ; 
and where the light is thrown in such a 
way that you can observe how your pro- 
cess goes on. It would occupy too 
much of this letter to deseribe the fur- 
nace minutely; but the best form for 
the fire is a grating, with a door and an 
ash-hole, around which is built a circular 
support of bricks, and upon the.top, of 
which is laid a round plate of cast iron, 
with a hole in the middle, suticiently 
large to permit your kettle to. descend 
into the aperture six or eight inches. 
Your aperture for smoke may be carried 
any distance horizontally, so that there 
15 no objection to your apparatus being 
in’ the middle of your elaboratory, I 
chave used nothing but copper kettles; I 
doubt not but iron may answer equally 
well, and from what follows must be, i 
soine respects, superior.” Capper, how- 
ever, from being much thinner, 1s more 
portable, and for this reason, no doubt, 
in, Numerous mstances, came and .con- 
tinued in. use in preference to iron, 
Having taken one hundred weight of the 
unrefined sperma ceti prepared as above, 
melt it together with about three gallons 
of water. As soon as it begins to. boil 
you must add, from time to time, smail 
portions of the following iguor, say haif 
a pint at a time: take of the alkaline 
Mode of Refining Sperma-Cett. 
167 
salt, known in commerce by the name of 
pot-ash, (moé pearl-ash) seven pounds ; 
pour on it two gallons of water; let 
them stand together twenty-four hours, 
and from the top dip off your ley as you 
want it, adding more water occasionally 
till the alkali isexhausted. ‘After boiling 
the sperma ceti for about four hours, 
having, during the process, taken off the 
scum as it arose, let your kettle be re~ 
moved from the fire, and after remaining 
about a quarter of anchour, dip off your 
sperma ceti into suitable coolers, This 
process it will be, in general, necessary 
to repeat three times. The third time, 
if the processes have been properly con= 
ducted, the sperma ceti will be as clear 
as cr ystak: and then, after it is cool, 
the only thing necessary to make it fit 
for sale is to cut it into moderately small 
pieces, when it will break into that flaky 
appearance which it has in the shops. 
The simplicity of these processes would 
induce us to believe that the most inex- 
perienced operator could not fail in suc- 
ceeding: however, there will arise many 
untoward circumstances, sometimes, so 
as to puzzle him a good deal. Ihave 
said that it will be necessary to press 
the sperm three times, and to boil it 
three times with the ley: but this is to 
be understood discretionally.. It mighe 
su happen, that twice pressing and twice 
boiling would be sufficient; and it might 
also happen, that four tines for each 
process, would not be more than is ne- 
cessary. 
experienced operator may stumble at; 
he might suppose that, after boiling for 
four hours, by adding more ley, he could 
shorten his processes. Of this it is ne- 
cessary he should be very cautious: for, 
in adding more ley at that time, he will 
be likely 1 not only to unite the oil, which 
is attached to the sperma ceti (and 
which indeed is the cause of its yellow 
colour) with the ley, but he will attach, 
or combine, the sperma ceti with it also, 
and in that case, he will find it impos- 
sible to keep it inthe kettle; the whole 
mixture, water, alkali, and sperma cell, 
forming. a frothy ae unmanageable [i- 
quid, making a kind of soap, which, 
1en coid, will be found to have lost the 
greater part of its flaky appearance; and 
indeed, without a chemical process, to 
he completely spoiled as sperma ceti, 
Should such an aceident as this happen, 
the most effectual mode of rectifying it 
is, to throw into the boiling liquor imme- 
diately, a diluted solution of the sul- 
phuric acid, till it recovers again ite for- 
. mer 
Another thing perhaps an in-' 
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