258 <),> Ihi Chemical Examination of 



been boiled witb nitric acid, tbe precipitate, witb nitrate of 

 silver, was white and curdy, indicating the presence of 

 chlorine. Chloride of barium gave a white precipitate, part 

 of which being dissolved with effervescence in nitric acid, 

 indicated the presence of carbonic acid ; a white powder re- 

 mained unacted on by the nitric acid, shewing that the salts 

 contained sulphuric acid. After a portion of the salts had 

 been heated to redness, the addition of bichloride of platinum 

 produced a yellow precipitate, proving the existence of potash 

 salts in the kelp. Oxalate of ammonia caused a slight pre- 

 cipitate of lime ; and phosphate of soda and ammonia, after 

 some time, a precipitate of ammonia-phosphate of magnesia. 



Quantitative Analysis of soluble baits. 

 Estimation of Sulphuric Acid. — Having separated by filtra- 

 tion a portion of the soluble from the insoluble salts, the 

 sulphuric acid was precipitated in the soluble salts, by the 

 addition of chloride of barium and muriatic acid, to dissolve 

 sulphites and phosphates. 



Sulphate of Sulphuric Acid, 



100 grains gave 14-21 4*89 



100 ... 14-34 4-94 



Mean per centage, 4-915 



Estimation of Sulphurous Acid.— To a solution of the 

 soluble salts, chloride of barium was added, which preci- 

 pitated the sulphuric, sulphurous, carbonic, and phosphoric 

 acids, as salts of barytes. This precipitate was thrown on 

 a filter and washed with hot water. The sulphate, sulphite, 

 and carbonate of barytes, which were on the filter, were 

 then treated with nitric acid, which converted the sulphite 

 into sulphate, and dissolved the carbonate. The sulphate 

 of barytes was then washed with water and weighed. The 

 difference between the weight of this precipitate, and that 

 of the sulphate of barytes previously obtained, indicated the 

 amount of sulphate of barytes formed by the action of the 

 nitric acid on the sulphite. From this the sulphurous acid 

 was calculated. 



Sulphate of Sulphuric Sulphuric Acid Dif- Sulphurous 

 Barytes. Acid. before obtained, ference. Acid. 



100 grs. gave 1575 5-40 4*915 -485 -392 



