8 ESSAYS AND OBSERVATIONS 



EXPER. III. 



To a drachm of newly dug ftone-marle, 

 deduced to powder, I gradually added 

 the milriatic acid, till no further effei- 

 vefcence enfued upon the additio-n. 1 his 

 mixture, diluted with a fufficient quan- 

 tity of water, was thrown into a filter 

 of gray paper: A pure pellucid liquor 

 palled through, and a grofs earthy fub- 

 ftance remained behind at the bottom of 

 the filter. This fubftance, when pro- 

 perly waihed and dried, weighed juft 

 eighteen grains. 



In this experiment, w^e find the marie 

 divided into two different parts ; the 

 one carried off by the muriatic acid, and 

 invifibly fufpended in it; the other an' 

 earthy fubftance, on w'hich that acid- 

 feems to have no influence. Having ad- 

 vanced thus far in the decompofition of 

 our fubje(5l, the next ftep is to examine 

 into the nature of thefe two conitituent 

 parts. 



