PHYSICAL anv LITERARY. 213 
wellknown that the cautftic fpirit of urine, 
or of falt ammoniac, does not emit air, 
when mixed with acids. This confide+ 
ration excited my‘curiofity, and determin- 
ed me to inquire into the truth of them 
all ‘by way of experiment.. I therefore 
engaged myifelf in a fet of trials; the hi- 
{tory of which is here fubjoined. Some 
new facts are likeways occafionally -men- 
tioned:; and here it will be proper to ins 
form the reader, that I have never men= 
tioned any without fatisfying myfelf of 
their truth by experiment, though [ have 
fometimes taken the liberty to negle& de- 
f{cribing the experiments when they feem- 
ed fufficiently obvious. 
DeEstrineG to know how much of an 
acid’a calcarious earth will abforb, and 
what quantity of air is expelled during 
the diflolution, I faturated two drams of 
chalk with diluted {pirit of falt, and ufed 
“the Florentine flafk, as related in a fimi- 
lar experiment upon magne/ia. Seven 
-drams and one grain of the acid finifhed 
sthe diffolution, and the chalk loft two 
‘Acruples and eight grains of air. 
Tuts 
