Intelligence and Miscellaneous Articles. 821 



the most accurate result. This hydrated salt is not quite insoluble 

 in boiling water. 



To test the applicability of the insolubility of the calcined anti- 

 moniate of soda to its separation from arsenic, a known weight of 

 pure antimony was mixed with arsenic, and the mixture deflagrated 

 with three times its weight of a mixture of nitrate and carbonate of 

 soda. After washing the mass with cold water and ignition, a quan- 

 tity of antimoniate of soda was obtained, which almost exactly cor- 

 responded with the weight which should have been obtained ac- 

 cording to theory. On examination before the blowpipe, the salt 

 proved to be perfectly free from arsenic. The arsenic was precipi- 

 tated from the solution with sulphuretted hydrogen, and determined 

 in the usual manner ; and its quantity likewise agreed perfectly well 

 with the amount employed. 



0*10 grm. tartar-emetic and as much arsenious acid were dissolved 

 in a thick soup, the organic matters destroyed as much as possible 

 by a long-continued current of chlorine, the heated liquid filtered, 

 the mass upon the filter well-washed, the solution saturated with 

 sulphuretted hydrogen and left for some time in contact with it ; the 

 precipitate filtered, washed, and then dissolved together with the 

 filter in hot nitric acid, the solution saturated with carbonate of 

 soda, some nitrate of soda added to it, the whole evaporated, and 

 the residue heated in a porcelain crucible until the sulphurets and 

 organic matter were completely oxidized, and the mass finally fused. 

 On exhausting the mass with water, 0*057 grm. antimoniate of soda 

 was obtained, while according to theory 0*058 should have been 

 obtained. The solution which contained the arseniate of soda was 

 evaporated to dryness ; all the carbonic, nitric and nitrous acids ex- 

 pelled by concentrated sulphuric acid ; the salt dissolved in water, 

 mixed with sulphurous acid; and, after expelling the latter, the 

 arsenic precipitated by sulphuretted hydrogen. To separate the 

 free sulphur, the precipitate was dissolved in very dilute ammonia, 

 and reprecipitated with sulphuric acid ; it weighed 0*120 grm., which 

 corresponds to 0*096 arsenious acid, which also is very near to the 

 amount employed. 



The author applied this insolubility of the antimoniate of soda 

 likewise to the preparation of antimony free from arsenic acid with 

 complete success. Commercial antimony was fused together with 

 \t\\ its weight of arsenic, the powdered regulus mixed with l£th 

 part of crude nitrate of soda (cubic nitre), and \ part carbonate of 

 soda, heated to faint redness, and the mass exhausted with water. 

 The residue of antimoniate of soda was, when dry, fused with half 

 its weight of cream of tartar, when a very beautiful white regulus 

 was obtained, which gave off not the slightest odour of arsenic be- 

 fore the blowpipe, and was characterized by the ease with which it 

 continued to burn away. Moreover the regulus neither contained 

 sodium nor potassium, which latter it generally contains when re- 

 duced from the antimoniate of potash. — Liebig's Annalen, May 1848. 



