40 



L. F. Nilson and Otto Pettersson. [Not. 18, 



analysis of its sulphate. Originally we also thought of analysing the 

 chloride by titration with silver nitrate, but having found that sublimed 

 beryllium chloride could not be obtained entirely pure, on account of 

 its corrosive action on glass, we gave up the idea. 



Sulphate of beryllium is undoubtedly a neutral salt, and is easily 

 obtained in beautiful crystals, which do not change in the air ; but at 

 100 — 110° C. it loses half of its water, at 250° it becomes anhydrous, 

 and after heating to light redness pure beryllia remains. Still there is a 

 difficulty in the analysis ; for anhydrous sulphate and pnre beryllia, 

 as obtained by calcination, are both very hygroscopic substances. "We 

 therefore chose the hydrated sulphate, which could be weighed with 

 the greatest accuracy, as the most fitting substance to start with ; this 

 salt allowing pulverisation and pressure* without losing a trace of its 

 constituent water. The sulphate was prepared by heating to dryness 

 an aqueous solution of sublimed chloride with an excess of pure sul- 

 phuric acid. By repeated crystallisation the sulphate could easily be 

 purified from a slight trace of calcium sulphate, originating from 

 the action of the gaseous chloride on the glass tubes. 



The analyses I, II, refer to beryllium sulphate obtained in this 

 manner ; for III, IV, the chloride was precipitated with ammonia 

 and the hydrate treated with sulphuric acid. The sulphate was 

 repeatedly crystallised. The difficulty in the analysis is the weighing 

 of the calcined beryllia. For this purpose the crucible, still red hot, 

 was placed in an exsiccator filled with anhydrous phosphoric acid, and 

 after cooling placed immediately on the scale pan of a Bunge's balance, 

 the equilibrium being beforehand approximately established. In this 

 manner the whole operation required only a few seconds. 



By spectroscopical test Professor Thalen has found the beryllia used 

 for these determinations to be absolutely pure. 



The hydrated beryllium sulphate has given in the determinations, 

 thus executed, the following values : — 



Experi- 

 ment. 



Weighed 

 Sulphate. 



Loss of water 

 at 100° C. 



Loss of water 

 and S0 3 . 



Beryllia. 



Equivalent of 

 beryllium. 



grs. 





per 

 cent. 



grs. 



per 

 cent. 





per 

 cent. 



= 8 



= 

 7-98 



I 

 II 

 III 

 IV 



3-8014 



2- 6092 

 43072 



3- 0091 



0-7696 

 0-5282 



20 -245 

 20 -244 



3-2627 

 2-2395 

 3 6973 

 2-5825 



S5-829 

 85-831 

 85-840 

 85-824 



0-5387 

 0-3697 

 0-6099 

 04266 



14-171 

 14-169 

 14-160 

 14176 



4-556 

 4-552 

 4 - 545 

 4-557 



4-544 

 4542 

 4-533 

 4-550 



Mean 











85-831 





14-169 



4-552 



4-542 



* It was pressed between sheets of fine, porous, bibulous paper, the surface of 

 wliich had been previously smoothed by heavy pressure. 



