338 Dr. E. van Aubel's Researches on 



of lead chloride, which was removed by filtration. The 

 solution of bismuth was then distributed among 10 glass 

 beakers holding about 4 litres each. The bismuth was pre- 

 cipitated as oxychloride on addition of water. The precipi- 

 tate was decanted and washed until no trace of HC1 could 

 be found. Then it was again dissolved in HC1, the bismuth 

 precipitated as oxychloride, and washed as before. And this 

 was done twelve times. The precipitate finally obtained was 

 carefully washed again, then dissolved in HC1. The bismuth 

 in this solution, to which water had been added, was precipi- 

 tated by the addition of ammonia and ammonium carbonate. 

 After decantation the precipitate was washed with water, 

 until all the ammonia had disappeared, and dissolved in HCL 

 This precipitation was repeated three times. 



Finally, the precipitate was dissolved in HC1, and the 

 chloride transformed into the oxychloride by addition of water. 

 The resulting precipitate, entirely freed from acid, was dried, 

 mixed with KCN, and reduced. The metallic bismuth was 

 again purified by a second fusion with KCN. 



The bismuths Classen I. and Classen III. were both pre- 

 pared under the direction of Prof. Classen in the laboratory 

 for analytical chemistry at the Polytechnical School at Aix-la- 

 Chapelle. 



Classen I. was prepared by Herr Norrenberg ; Classen III. 

 was obtained by Herr Magdeburg by means of the " Bis- 

 muth Purissimum " from the Schucharell works at Gorlitz. 



Finally, we are indebted to the kindness of Prof. Classen 

 himself for Classen II. 



Second Method. 



The product used in this second method was the " bismuth 

 subnitrate purissimum " of Dr. Marquardt, at Bonn, which 

 was employed by Marignac in his determination of the atomic 

 weight of bismuth. 



One kilogram of this product was dissolved in HC1, and the 

 solution was divided among 22 glass beakers, having a capa- 

 city of 4 litres each, and these were filled with water. The 

 precipitate of oxychloride was washed with water until all the 

 HC1 was removed. The solution in HC1 and the precipitation 

 by means of water were repeated three times. Then the preci- 

 pitate was again dissolved in HC1, precipitated with ammonia 

 and ammonium carbonate, and thoroughly washed with water. 

 These operations were also repeated three times. 



Finally, the precipitate was once more dissolved in HC1, 

 the bismuth oxychloride obtained by the addition of water, 

 and reduced hv means of KCN and soda. 



