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ANNUAL OF SCIENTIFIC DISCOVERY. 



little elasticity and sonorousness; but these characters are less obvi- 

 ous, and require experiments to determine them, while it is easy to 

 recognize the character of brittleness and want of tenacity. We 

 propose, therefore, to consider as semi-metals those metallic elements 

 which are neither ductile nor malleable, in other words, the brittle 

 metals. M. Nickles, Silliman's Journal. 



THE MELTING POINTS OF SOME OF THE ELEMENTS. 



The following paper, by Mr. William Crosby, an English chemist, 

 we derive from the London Chemical News : 



It is remarkable that in almost all the series or groups of the ele- 

 ments mentioned by Mr. Coleman there appears to exist a peculiar 

 relation between the atomic weight and the melting point, which to a 

 certain extent confirms his opinion that the equivalent number of an 

 element expresses a certain amount of force, modified by its atomic 

 volume. As an illustration we will take the group zinc, palladium, 

 platinum. 



Here we have a group of elements having a like atomic volume with 

 an increasing atomic weight, not only decreasing in active chemical 

 attraction, but decreasing in fusibility as the weight of the atoms in- 

 creases. Does the atomic weight here represent a force ? We think 

 so, because it appears general. Let us pass on to some other groups. 



Here we have four groups, in each of which the elements having the 

 least atomic weight offer the least resistance, not only to the action of 

 other elements, but also of heat. In so many groups, taken, as it were, 

 at random, it cannot all be accident. There are, however, excep- 

 tions : we find them in the following groups : 



