( 148 ) 



III roiitinuiiii^- tliL'!S(\ oxiiuiimcr.ts it will in tliu first place bo our 

 j)urpü8c to niiiko out ii'iii the aetlieiloimiitioiis, taking place in alcohols 

 diluted with water, the same conduct appears as in the transformations 

 of the dinitrobenzenes treated here. Further we shall try to fiud 

 substances the transformations of which adapt themselves to a 

 quantitative study, both in alcohol and water and iu any mixture 

 of these two solvents, with &imuUuneous estimation of one of the 

 ])roducts. 



Chemistry. — „On .wine. anoDudies in the ttijtitein ofMnNDEhEJKVv". 

 By Prof. Tii. li. Beiiuess. 



In his fourth paper on isomoiphism („Beilriige zur Kcnntnis des 

 Isomorphisnnis", IV, in „Zeitschr. f. physik. Chemie, VIII, 1) Mr. 

 J. W. RiiTGERS has denied the existence of isomorphism between 

 tcllurates and sulfates and has given to tellurium a place between 

 Ru and Os (Fe := 56, Ru = 104, Te = 128, Us = 195). His views 

 are founded on two facts : on tlie absence of compound crystals, com- 

 posed of Kn SO4. and KsTeOj, and on the existence of isomorphism 

 between chlorotellurates, chloroplatinates and chlorostannates. In the 

 second place the anomaly iu the differences of the atomic weights 

 of Sb, Te and J is mentioned and likewise the analogy between 

 H<> Te and Hg S, but the principal weight is attached to the con- 

 clusion deduced from isomorphism. His first assertion is drawn from 

 experiments with KjMnOj., a compound, forming green crystals 

 with K3 Süj. , but not with Kg Te Oi. . It has been confirmed by 

 experiments with AggCrOi. , by which compound growing crystals 

 of Ag2 SO4 are stained from amber yellow to a fiery red, while it 

 docs not enter into crystallizing AgoTe04. 



Where Mr. Retgers has made use of isomorphism between chloro- 

 tellurites (he writes: chlorotellurates) and chloroplatinates, to sub- 

 stantiate his second assertion, his argumentation is less stringent, 

 as he has not given experiments of his own. The base of his second 

 assertion must therefore be thoroughly tested. 



No compound crystals were obtained with TeCl|. and Pt CI4, the 

 solubilities of the two compounds K3 Pt Cls and Ko Te CIq differing 

 too much. With Csg Sn Clc and Cso Te Cle and with Csg Os Clg and 

 Csg Te CIq better results were obtained. Beautiful compound crystals 

 were produced by adding Cs CI to mixed solutions of Te CI4 and 

 lrCl4 strongly acidulated with hydrochloric acid. In this case the 

 compound crystals were light brown, while the one of the compo- 

 nents is yellow, tiie olher red-brown. 



