34 :essay5 and observations 



fire, and powdered, * were mixed with a 

 quantity of dilated acid of fea fait. No 

 vifible eflFervefcence enfued upon the mix- 

 ture ; but a remarkable degree of heat was 

 generated. "When as much of the acid 

 was added, as I judged necefTary to dif- 

 folve all the calcarious earth contained 

 in the marie, I filtered the mixture in the 

 ufuai way. The refidue weighed four 

 grains, did not concrete by drying, and 

 was confiderably whiter than the refidae 

 of the marie in its natural ftate. The 

 filtered liquor was of a yellowifli hue, and 

 upon the addition of an alkaline folution, 



precipitated 



alleged. In the fame manner, when acids are applied 

 to this calcined fubilance, they find no difficulty, even 

 without a previous pulverization, and without the af- 

 fiftance of efFervefcence, to reduce the whole to powder ; 

 becaufe they diflblve the cenaent. 



* The caution formerly given with regard to procu- 

 ring lime-water from calcined marie, muft alfo be obfer- 

 ved in the application of acids to this body ; for, withont 

 a previous pulverization, the experiment is generally uh- 

 fuccsfsfiil. 



