212 Mr. P. Henry on the Aétion of 
was made, fubfiding to the bottom of the veffel, 
along with the arfenic, 
1o. ‘Three ounces of Sperma Ceti oil were di- 
gefted with one drachm of litharge, during fix hours, 
in about 200° of Farenheit. ‘The oil became much 
clearer than before the experiment, but not near 
fo colourlefs,.as when treated with arfenic. The 
litharge was changed to a white colour. Part of the 
oil being poured off, and the heat afterwards in- 
creafed, it foon became thick and high coloured, 
11, Lin-feed oil expofed to the fame degrees. of 
heat, under fimilar circumftances, underwent the 
fame changes. 
12. ‘Train oil was little siege; in low degrees 
of heat, but in higher degrees, became difcoloured. 
13. A few drops of vitriolic acid being added 
toa portion of No. 10, before the heat had been 
encreafed, the litharge was precipitated, and the 
oil left pure and clear, though not quite colour- 
lefs. 
14. Vitriolic acid being added to the lin-feed 
and train oils, No. 11, and 12, a very fmall preci- 
pitation of the litharge took place, probably owing 
to the heat not having been fufficiently great to 
diffolve it in large quantities, which had been found 
to be the cafe with the fame oils, when digefted 
with arfenic, 
15. Nitrous acid, whén added, inftantly chang- 
ed the colour of all three toa dark brown; the oils 
No, 11 and 12 became thick and glutinous. ig 
. 16. Marine 
