Science progress. 



No. 20. October, 1895. Vol. IV. 



RECENT PROGRESS IN THE STUDY OF 



ALLOYS. 



I^HE systematic knowledge that we possess concerning 

 the chemical relations of the compounds formed by 

 non-metallic elements with each other, and with the metals, 

 renders it surprising that we should know so little about 

 the nature of alloys, that is, of bodies in which only metallic 

 elements occur. 



A great deal of attention has been given to this class of 

 substances, and many isolated facts are known concerning 

 the properties of individual alloys, but general laws have 

 yet to be discovered. Much of our knowledge is, in fact, 

 the accumulated tradition of technical workers, and it would 

 not be a far-fetched illustration to compare the present state 

 of the chemistry of alloys to that of chemical science in 

 general before the time of Boyle. 



It is easy to point out some of the special difficulties to 

 which this state of affairs is due. When non-metals com- 

 bine with each other or with metals, the products, as a rule, 

 differ widely in properties from the original substances ; 

 hence the separation of the product in a pure state is a 

 comparatively easy task. But this is not the case when 

 two metals combine to form a compound : hitherto no alloy 

 has been discovered which is more volatile than the metals 

 composing it, and, though differences in fusibility exist, they 

 are hardly sufficient to permit of the isolation of pure sub- 

 stances from mixtures. 



6 



