[ 291 ] 



ther pound of the alkaline folution with 3647 grains of dilute vi- 

 triolic '^cid, and after evaporation and ignition found the fait to 

 v^'eigh 2090 grains, and as he thinks he has proved the quantity 

 of alkali in 5760 grains of the alkaline folution to be 1283 grains, 

 hence he concludes the quantity of acid in the 2090 grains to be 

 2090 _ 1283 = 807 grains ; if fo, vitriolated tartarin fliould con- 

 tain but 38,6 grains per cent, of acid, whereas it has been proved 



to contain much more. But allowing the quantity of alkali in 



the pound of alkaline folution to be, as I ftated it, 11 40 grains, 

 then as ^^ parts alkali take up 45 of real vitriolic acid, 1 140 will 

 take up 933 of this acid, and the fum of both will be 2073, which 

 differs from 2090 only by 17 grains, owing probably to the mu- 

 riated tartarin contained in his alkaline folution, which may even 

 have been decompofed by the vitriolic acid. He determined, it is 

 true, the quantity of vitriolic acid by another operation, § t8, 

 but here a material and evident error occurs, as I fhall prefently 

 {hew: 



ift. To 8460 grains of vitriolic acid, whofe fp. grav. was 

 1,8553, he added 19200 of water, or, which is the fame thing, 

 to 84,6 of the concentrated acid he added 192 of water, and 

 found the fp grav. of the mixture 1,214. 



2dly, He faturated 9075 grains of this dilute acid with 3215 

 grains of the chalk above-mentioned, and as by his account looo 

 parts of that chalk contained 559 of lime, he concluded that 



Oca 3315 



