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line acid retained fomc, or that a fufficiency of the vitriolic acid 

 was not added. This earth is not therefore a proper tell of vi- 

 triolic acid, at leaft not as proper as the barytic. 



To obtain a lefs circuitous proof of the proportion of ingredi- 

 ents in ICO parts of this fait, I precipitated a folution of lOO grs. 

 of cryflallized muriated ftronthian by mild foda ; the precipitate 

 after ignition weighed 56,75 grains, but thefe being difTolved in 

 marine acid gave out 17 grains of fixed air, and therefore contained 

 only 39,75 of mere earth. 



sdly. I precipitated a folution of another 100 grains of this 

 cryflallized fait by a folution of nitrated filver, and found the pre- 

 cipitate duly dried to weigh 1 10 grains, a weight which indicates 

 the prefence of 18,19 grains real marine acid The weight of the 

 3d ingredient, namely water, muft therefore amount to 42,06 

 grains nearly, as Dr. Hope has ftated. 



Hence we may rate the proportion of ingredients in 100 parts 

 of this fait at 40 of earth, 18 of acid, and 42 of water. And to 

 100 parts of the deficcated fait we may allow about 69 of earth 

 and 31 of acid. 



Hence \ 00 parts Jironthlan earth take up 45 or more, exa^^lly 

 46 of real marine acid, and fhould afford 250 of cryftil'ized, or 

 145 of deficcated muriated flronthian. And 100 /arts real marine 



acid 



