OP ARTS AND SCIENCES. 177 



VI. 



A METHOD FOR THE SEPARATION OF SODIUM AND 



POTASSIUM FROM LITHIUM BY THE ACTION 



OF AMYL ALCOHOL ON THE CHLORIDES, 



WITH SOME REFERENCE TO A SIMILAR SEPARATION OF 

 THE SAME FROM MAGNESIUM AND CALCIUM. 



By F. a. Gooch. 



Presented June 16, 1886. 



For the quantitative separation of lithium from sodium and potassium, 

 Mayer's method,* which is based upon the precipitation of lithium as 

 the tribasic phosphate, and Rammelsberg's f mode of parting the chlo- 

 rides by means of a mixture of anhydrous alcohol and ether in equal 

 parts have been available. 



The method of Mayer grew out of the older process of Berzelius,^ 

 which consisted essentially in treating the solution of the alkaline salts 

 with phosphoric acid and sodium carbonate in excess, evaporating to 

 dryness, and extracting with cold water. The result of a single 

 analysis of the product thus obtained was the testimony upon which 

 Berzelius rested the belief and statement that the salt was a double 

 phosphate of lithium and sodium, which left upon ignition sodium and 

 lithium pyrophosphates in equal molecules ; and on this Berzelius based 

 his process for the estimation of lithium. Rammelsberg,§ however, 

 showed later that it was a tribasic phosphate which was actually ob- 

 tained, and from his experiments arrived at the conclusion that the 

 proportion of soda and lithia were variable within wide limits, the 

 amounts of the former varying in the special cases investigated from 

 7.84% to 28.38% ; and the same thing in substance was reiterated 

 subsequently || in an account of a repetition of the work suggested by 

 the criticism of Mayer. Mayer,1[ however, was unable to prepare 

 under any conditions the double phosphate of Rammelsberg, and ob- 

 tained invariably, when the preparation had been washed with suffi- 



* Ann. d. Chem. u. Pharm., xcviii. 193. § Loc. cit. 



t Fogg. Ann., Ixvi. 79. II Pogg. Ann., oil. 443. 



t Ibid., iv. 245. 1 Loc. cit. 



VOL. XXII. (n. 8. XIV.) 12 



