Cludybeate Water from Vicar'*s Bridge. 287 



weighed .03 grains. On examining its solution in water by 

 muriate of platinum, it appeared to contain both soda and potash. 



(/t) The matter left undissolved by the water in^ was treated 

 with dilute sulphuric acid, the solution filtered and evaporated 

 to dryness ; and the residue ignited. Redissolved in water, the 

 solution gave, by spontaneous evaporation, a quantity of pris- 

 matic crystals, having the appearance and all the properties of 

 sulphate of magnesia. By subtracting from the weight of the 

 saline mass in (e), that of the substances afterwards separated 

 from it, we get 3 grains for the amount of the sulphate of 

 magnesia*. 



(i) 3 cubic inches of the water were precipitated by muriate 

 of baryta. The sulphate of baryta after ignition weighed 67.32 

 grains, equivalent to 22,82 grains of sulphuric acid. 



(k) 3 cubic inches of the water were precipitated by ammo- 

 nia, and the liquid filtered and concentrated by heat to nearly one- 

 third of the original bulk. Sulphate of silver was then added, 

 which caused a slight muddiness, but no immediate precipitate. 

 In two or three days a little chloride of silver had fallen, which 

 was collected and ignited. It then weighed .05 grain, equiva- 

 lent to .0126 of muriatic acid. 



In 3 cubic inches of the Vicar''s Bridge water we thus have, 



Oxide of iron, (b) and (e)y . 

 Alumina, (c) 

 Magnesia, (hj 



Lime, (d) .... 

 b-. Soda and potash,t (g) 



Sulphuric acid, (i) » • • 



Muriatic acid, (kj . • . • 



42.651 



* I have thought it unnecessary in making the deduction to compute the 

 residue of .03 in (g) as a sulphate, because it still retained a trace of deli- 

 quescent matter, and also a minute quantity of alkaline sulphate, which had 

 escaped decomposition by the barytic salt. 



t'For the reason stated in the above note, I have thought it better to com- 

 pute the amount of the soda and potash from the quantities necessary to 

 saturate the muriatic acid, with which they were plainly in combination, 

 than from the residue of .03 grains taken as chlorides. The variation is not 

 greater than about .005. 



