168 
mer appearance; the alkali uniting with 
the acid, and quitting, in course, the - 
sperma ceti. Another erfor may pos- 
sibly be committed here: #f a greater 
quantity of acid be added, than is neces- 
sary to saturate the alkal, it will in 
course dissolve a portion of the copper 
vessel which contains it; and it will be 
necessary therefore to suspend your 
Operation at once, and after being re- 
moved from the fire, and standing a 
quarter of an hour, or longer, as before 
directed, let it be dipped off into the 
coolers; for should the operator, after 
having made the sperma ceti manageable, 
be tempted to continue his process, and 
throw in fresh ley, another decomposition 
will take place: the sulphate of copper 
will be decomposed, ard the sperma 
ceti will become as green; in all proba- 
bility, as grass; and which will give him 
just as much trouble to remove, as the 
superabundant alkali did. In this case 
it will be. necessary to suspend the 
operation immediately, and, with a fresh 
portion of water, to boil the sperma ceti, 
adding diluted sulphuric acid, till it as- 
sume its natural colour. This being 
done, and cooled again, you may conti- 
nue your processes as belore directed. 
I have been thus minute, because I fell 
into these errers myself, and therefore 
can speak with precision and certainty 
about them. The danger of rendering 
‘the sperma ceti deleterious, may in some 
‘measure be avoided by using iron ves- 
‘sels; but in both cases, to make it pure 
again after such errors, the same pro- 
‘cesses inust be gone into; and to those 
acquainted with the nature of chemical 
afiinity, the purification, in either case, 
is equaily safe and complete. 
In the boilings, from time to time, a 
good deal of froth arises, and as, in 
taking off the froth, you must necessarily 
take off a portion of the sperma ceti; to 
be economical, this froth must not be 
thrown _awav, but be treated with sul- 
‘phuric acid, tr even water alone, in 
order to separate the adhering sperm : 
experience only wil] direct us here. 
Of the alkali, it will be necessary to 
‘say something: I have mentioned before, 
that pot-ash, and not pearl-ash, is to be 
used. The reason is, that pot-ash pos- 
sesses a degree of causticity, which pear!- 
ash dues not, and which enables it to act 
‘upon the oil attached to the sperma 
“ eeti, with greater effect. I never tried 
’ the agua kali puri, of the London Col- 
‘lege but I should imagine, it would an- 
_ swer the purpose equally well, if not 
Encroachments of the Sea. 
[Se pt A y 
better: but the solution of pot-ash being 
more ready at hand, it has been more 
generally used. I am perfectly aware 
that chemistry dues not recognize such a 
distinction as pearl-ash and pot-ash; but 
In writing upon the refining of sperma 
ceti, T thought it better to adopt terms 
commonly used, thin to use those under- 
stood by a few: besides, I apprehend, 
that the pot-ash which T recommend, is 
not the pot-ash understood in chemistry, 
exactly. By the pot-ash of chemistry, 
we understand pure pot-ash, completely 
‘caustic. Pearl-ash is a carbonate of 
pot-ash. The pot-ash of commerce, is 
in part carbonated, though not complete- 
ly so. 
_ It may be supposed that, by repeated 
boilings, the sperma ceti would become 
rancid ; m other words, acquire a portion 
of acidity; but nothing of the kind takes 
place; the presence of the water, con-. 
stantly keeping the sperma ceti rather 
below’ than above the boiling point, 
‘or 212° of Fahrenheit. If,  there- 
fore, you have any reason to suppose 
your water is becoming short by evapo- 
ration, it will be necessary, during the 
boiling, to add more; not to mention 
that, when your alkali is more closely 
concentrated, by such evaporation, there 
is greater danger oF your converting the 
sperma ceti into soap, or rather into the 
unmanageable inass before-mentioned. 
The theory then is simply this: pot- 
ash hes a greater affinity with the sperma 
ceti ou, than with the sperma ceti; but 
that affinity is so little different, that - 
without care, the refining éannot ‘be 
effected; and with care, nothing is more 
‘easy. 
without heat, and that too long conti- 
nued. If, however, the heat be too 
long continued, it is evident that the 
two affinities unite into one, or become 
equal, and thus confound the operation. 
Huntspiil, Your’s, &c. 
July 8, 1809. James JENNINGS. 
—SE Ea 
For the Monthly Magazine. 
“ENCRUACHMENTS Of the SEA, ° - 
O* this subject, the following par- 
ticulars bave been related by a 
petsou whose veracity cannot be-ques- 
tioned, however he may have been im- 
posed on in some points by the Dutch 
skipper who gave him the information, 
At every event, the facts, asthey are 
reported, are interesting, and deserving 
of further enquiry. 
About the year 1798, the captain of a 
Dutch Surimam ship, belonging to Am- 
_ sterdam, 
\ 
Again, these affinities act not_ 
