[ 25^ ] 



60- The folution of marine felenite being flightly boiled, 

 lime-water was added to it ; a cloud ftill appeared, but the pre- 

 cipitate was much lefs copious than when the unboiled folution 

 was ufed. 



y"- To a folution in the nitrous acid, not of marble, but of 

 lime formed of marble, lime-^vater was added ; no precipitate or 

 cloudinefs enfued. 



Hence it is clear that the precipitation, formed by the 

 addition of lime-water to the acid foiutions of Carrara marble,, 

 confifted of the lime itfelf contained in the lime-water, and not 

 of that united to the mineral acids, being occafioned by the 

 fixed air abforbed by thofe acid foiutions after or during its 

 extrication in the ad of folution; for this precipitate muft be 

 either argill, magnefia or calcareous earth ; if it were argill or 

 magnefia the precipitate would be as copious from a boiled as 

 from the unboiled folution, the contrary of which we have feen 

 in the 6th experiment ; it fhould alfo be found in the acid 

 foiutions of lime, which is contraditled by the 7th experiment ; 

 if it were an earth feparated from an acid it fhould be in the 

 ftate of lime, and confequently foluble by an addition of more 

 water, contrary to the 3d experiment ; but if we fuppofe it a 

 calcareous earth, precipitated from the lime-water by the fixed 

 air contained in the acid foiutions, all the phenomena exhibited 

 by thefe experiments muft naturally occur. This air will pre- 

 cipitate the lime in the lime-v/ater added, as in the 2d expc- 



I i 2 riment. 



