260 On th< } Chemical Examination of 



Estimation of Phosphoric Acid. — To the solution from which 

 the sulphuric acid had been precipitated by chloride of barium 

 and muriatic acid, after separation of the precipitate, am- 

 monia was added, when phosphate of barytes fell. 



Phosphate of Phosphoric Phosphoric Acid, 



Barytes. Acid. per cent. 



200 grains gave 2-02 -649 -3245 



Estimation of Carbonic Acid. — The carbonic acid in the 

 soluble salts was determined in the same manner as in the 

 insoluble salts, by passing the gas evolved by muriatic 

 acid from the solution of the salts, through caustic barytes 

 dissolved in water. The carbonic acid precipitated the 

 barytes as carbonate, from which the carbonic acid was 

 calculated. 0( j j 



Carbonate of Carbonic Carbonic AcicLm* 



Barytes. Acid. percent. 



500 grains gave 48-62 109 2-180 



Estimation of Chlorine. — A solution of the soluble salts 

 was boiled with nitric acid to convert the sulphurets into 

 sulphates ; the chlorine was then precipitated by nitrate of 



Bilvei i1jii[fj5q'loobif)oi9rIT 



15 grains gave 14-1 3-52 23-40 



15 ... 15-5 3-88 25-33 



Mean, 24-365 



F rtarfrTfrrs-acirfw «JPrLR1&d * HIJjibjjHii<7 to 8890X9 



Estimation of Iodine. — This, which is one of the most 

 valuable constituents of kelp, was determined by the follow- 

 ing method, which has yielded results very satisfactory : 



A portion of the kelp was exhausted of its iodides, by di- 

 gestion several times in alcohol. The alcholic solution was 

 then evaporated to dryness, and to convert any sulphuret 

 which might have been taken up by alcohol into sulphate, 

 was deflagrated with chlorate of potash, and kept at a red 

 heat till any iodate that might have been formed by the 

 action of the chlorate of potash, was decomposed. The mass 

 was then dissolved in water, and the iodine precipitated by 

 means of chloride of palladium, as iodide of palladium, which 

 was drior! r.| 212 r Fahr., and weighed : 



