18 ACCOUNT or tHe SPRAY 
time was then poured off and f{pirit of vitriol dropped into 
it, yet not the leaft precipitation enfued. 
That I might not be led into error by the vinegar not 
being good of its kind, I repeated thefe experiments with 
chalk ; and as both effervefcence and precipitation took 
place it was evident that there was no defed in the vine- 
ral. 
Exp. 3d. A-fmall piece was expofed to the heat of a 
blackimith’s forge during fifteen hours. Upon taking it 
out and pouring water upon it, no ebullition enfued: ne- 
verthele(s it tafted like weak lime water; being then di- 
vided into two portions, a folution of mild fixed alkali 
was dropped into the firft, and immediately a precipitation 
enfued. The fecond portion being expofed to the air in a 
tea-cup foon. contracted. a changeable coloured film, which 
next morning was become very thick, refembling in every 
refpect that of lime water. 
Exp. 4th. Hot water being poured on fome of this fub- 
ftance reduced to powder and the whole fuffered to fettle, 
the clear liquor had not the tafte of lime water as in the 
3d experiment ; neverthelefs a folution of mild fixed alkali 
being dropped into it as copious a precipitation enfued as 
when the earth had undergone calcination. 
As I had-neither the nitrous nor muriatic acids, nor even 
cauftic fixed alkali, [ had it not in my power to make any 
trials with them. 
From thefe experiments we may, perhaps, be authorized 
to draw the following conclufions. 
1ft. That this concrete is not an alkaline earth, as it is 
not affected either by the vitriolic or vegetable acids. 
adly. We may, with more probability, fay that it is a 
combination of an acid witha calcareous earth, and that it 
might with propriety be ranked amongft the felenites. 
This fuppolition is founded on the following reafons: 1ft, 
It appears from the 4th experiment that it is partially fo- 
luble 
