110 An ANALYSIS of 
water through it feveral times. Being then dried on the fil- 
trating paper, it contracted greatly, and was divided by fiffures , 
into a great number of fmall parts, as would have happened to 
fine clay, had the fame quantity of it been dried on paper in a 
fimilar manner ; and when it was feparated from the paper, and 
further examined, it fhewed the qualities of an argillaceous 
earth, combined with a {mall quantity of colouring matter. 
This appeared by the following experiments : 
1. I pur fome of it, which I had procured in different expe- 
riments, into ayplatina {poon, and made it red hot. While 
heating, it firft became black, then underwent a flight inflam- 
mation, and afterwards became white, without changing its ex- 
ternal form, being only a little contraéted in its fize, and dimi- 
nifhed in its weight. 
2. To another fmall mafs of it, laid ona plate of glafs, I 
added a drop of aquafortis, which neither effervefced with it, 
nor diffolved it, but only changed the colour to a paler red. 
3. ANOTHER {mall portion, which had been gently calcined, 
was well mixed with an equal weight of the aerated foflil alkali, 
and then expofed to a ftrong heat in the platina fpoon. ‘The 
alkali was quickly melted and became cauftic ; but I could not 
by its means bring the earth into fufion, or if any was diflolved 
by the melted alkali, it was only a very {mall portion, not per- 
ceptible by the appearances. 
4. Nor did I fucceed much better, when I tried to melt or dif- 
folve it by means of borax, heated on charcoal with the blowpipe. 
A little mafs of this earth continued undiffolved in the melted 
borax, and without any appearance of effervefcing with it, until 
I was tired of the experiment. } 
Turs earth therefore cannot be any other than the argilla- 
ceous. Had it been the filiceous, it would have been melted with 
the alkali into a tranfparent glafs, which happened eafily with 
different {pecimens of pure filiceous earth, fubjected to the fame 
trial; and had it been any of the alkaline earths, the borax 
would 
