L ow] 
Mr. Lavoifier, in difcuffing the merits of that memorable con- 
troverfy which his experiments have for ever clofed, diffolved 
a large quantity of chalk in fpirit of nitre, whofe fpecific gravity 
was 1,2989, and found that 1153 grs. Troy of chalk contained 
606,47 of earth, which required 2835 of that fpirit of nitre 
for their folution. Now 100 parts of this fpirit of nitre contain 
by my table 49,6 of ftandard, and confequently the above 
quantity contains 1406,16. Now if 606,47 of this earth take 
up 1406,16 of ftandard, roo of the earth fhould take up 232, 
which appears lefs than my eftimation; but it muft be remem- 
bered that I deducted 3 grs. per cent. for foreign earth mixed 
with the marble, and it is certain that chalk is more impure; 
then if it contains lefs of calcareous earth it muft take propor- 
tionably lefs of ftandard ; the proportion of foreign earth may 
even thus be detected. By this teft it would appear that the 
chalk ufed by Mr. Lavoifier contained but 46,5 per cent. or 0,465 
of its weight of earth really calcareous. 
Mr. Wenzel’s experiments on calcareous earths are fo com- 
bined with his opinion of the prefence of the acidum pingue or 
caufticum, that no clear conclufion can be deduced from them. 
Of the Relation of the Muriatic Acid to Calcareous Earths. 
158 grs. of powdered marble were taken up by and faturated 
402 grs. of fpirit of falt, whofe fpecific gravity was 1,1355. 
This acid contained 0,34 of its weight of ftandard, and con- 
fequently 
