346 ON TWO >'EW CRYSTALLINE COMPOUNDS 



and an insoluble white powder, which was a mixture of basic nitrate of antimony and 

 of antimonious or antimonic acid. 



8th. Hydrochloric acid mixed with a few drops of nitric acid completely dissolved 

 the compound, and a solution was obtained of chloride of zinc and chloride of anti- 

 mony, from which the two metals could be precipitated and determined in the usual 

 way. 



The most obvious explanation of all these phenomena seems to be, that SbZuj is a 

 radical in which the affinity between the elements is very feeble. The rapid decompo- 

 sition of water ; the facts that pure hydrogen, and not antimoniuretted hydrogen, is 

 evolved during the process ; that rapid decomposition is produced by the alloys of zinc 

 and antimony only when they have the composition of SbZuj ; and, finally, that the 

 composition of SbZug is similar to that of SbMcj and SbAe3, zinc, an electro-positive 

 metal, supplying the place of an electro-positive radical, — all point to the conclusion 

 that SbZuj belongs to the ammonia family. On the other hand, the action of strong 

 chemical agents on the compound proves that the affinity between its elements is very 

 feeble, and that these agents, under ordinary conditions at least, have a stronger affini- 

 ty for the zinc of the radical than for the radical itself 



Should the opinion here advanced in regard to the nature of SbZuj be correct, it un- 

 doubtedly ■will be soon substantiated by the examination of other similar compounds of 

 antimony or arsenic. Moreover, it is not impossible that by some indirect process 

 compounds of SbZuj may yet be prepared, since only the most obvious methods of 

 combining it have been hitherto tried, my attention having been diverted to what I re- 

 garded as a more important subject, the variation in the composition of its crystals. 

 This it is the especial object of the present memoir to elucidate, and here the very 

 feebleness of the affinity, which prevented the formation of compounds, has been of 

 the greatest advantage, by increasing the extent of the variation, which otherwise 

 would probably have been confined within such narrow limits that the discovery of 

 the law which it foUoAved would have been impossible. I propose soon to investigate 

 more fully the chemical relations of this peculiar compound, and, should any im- 

 portant results be obtained, they will be communicated in a future paper. 



II. Binantimonide of Zinc, or Stihiohizincyle, SbZn^. 



Crystals of this compound, having almost exactly the same composition as the theo- 

 retical SbZuj, can be obtained by melting together 31.5 per cent of zinc and 68.5 per 

 cent of antimony, and crystallizing, with the precautions already described. From 32 

 per cent of zinc and 68 of antimony smaller isolated crystals are formed, and therefore 



