[ 269 ] 



Hence ioo parts of this fait contain 42,75 of real marine acid, 

 25, or making allowance for lofTes, 28 of mere vol-alkali, and 

 29,25 of water of cryftallization and compofition. 



Hence ioo parts mere vol-alkali take up 152,68 of real marine 

 acid, and fhould afford, if there were no lofs, 357,14 parts of 

 fublimed fal ammoniac. And 100 parts marine acid take up 65,4 

 nearly of mere volalkali, and fhould afford 233,9 parts of fublimed 

 fal ammoniac ; but in fubliming fal ammoniac there is always fome 

 lofs. 



Mr. Cavendilh, in the Philofophical Tranfadions for 1766 tells 

 us, that 168 parts aerated vol-alkali, containing 52,8 per cent, of 

 fixed air, faturated as much marine acid as 100 grains of marble, 

 which contained 40,7 per cent, of fixed air ; now roo grains of this 

 marble contain, by the analogy formerly given, (45 of fixed air to 

 55 of lime) 50 grains of lime, by the 2d table, take up 42,2 of real 

 marine acid, and 100 grains of the aerated vol-alkali there men- 

 tioned, contain 24 per cent, of mere alkali, and confequently 168 

 grains of it fhould contain 40 of mere alkali, which by the above 

 flatement would require for faturation 61 of real marine acid. 

 This experiment would have made me doubt of the propriety of 

 the above conclufions, had not Mr. Cavendifh exprefsly flated that 

 his foiution of marble was faturate, (and confequently as a fatu- 

 rate foiution cannot be obtained without heat, which he did not 

 apply, he mufl have added an excefs of marble, and judged the 



foiution 



