Chemistry mid Physics. 383 



curved and twisted in a manner comparable only to those 

 strangely contorted smoky quartz crystals from Mount St. 

 Gothard, Switzerland, and to some crystals of pearl-spar (dol- 

 omite). _ The crystal described is so bent that an edge s'/s 

 {111/1 U), which should be horizontal, stands nearly at an 

 angle of 45° from its proper position. The crystal weighs one- 

 sixth of a gram and has a density of only 4*27. The prismatic 

 cleavage is well marked by internal reflections. The hardness 

 seems to be slightly above five. 



Newark, N. J., September 7th, 1888. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the Relation of Solubility to Fusibility. — Carnelley and 

 Thomson have devised a simple and efficient apparatus for deter- 

 mining the solubility of substances in various solvents and have 

 applied it to the estimation of the solubility of the isomers meta- 

 nitraniline and para-nitraniline in thirteen different solvents. 

 With the aid of these results, together with others already on 

 record, these authors have discussed the close relation which exists 

 between the solubility of isomeric carbon compounds and their fusi- 

 bility, already pointed out by one of them several years ago. 

 Starting from the observation of Pictet that the lower the melt- 

 ing point of a solid, the longer are the oscillations of its molecules, 

 so that the product of the melting point, measured from the abso- 

 lute zero, by the length of oscillation is constant, the authors 

 reason that of two isomers, the one with lower melting point 

 will, at any temperature below this point, have its molecules 

 moving with oscillations of greater amplitude than the one with 

 the higher melting point; and consequently, the molecular 

 weights being equal, the force of restitution will be less in the 

 case of the more fusible compound, and its molecules, being in a 

 less stable condition, will be the more- readily separated from 

 their fellows. Now inasmuch as, in order that a solid may dis- 

 solve in any liquid, its molecules must undergo a sort of unloosen- 

 ing process, the conclusion is legitimate that of two isomeric 

 bodies, that one should dissolve the more readily in which the 

 attraction toward the mean position is least, i. e., the more fusi- 

 ble one. The authors conclude : 1st, that for any series of iso- 

 meric organic compounds, the order of solubility is the same as 

 the order of fusibility, the more fusible body being the more sol- 

 uble one. 2d, in any series of isomeric acids, not only is the 

 order of solubility of the acids themselves the same as the 

 order of fusibility, but the same order of solubility extends to all 

 the salts of these several acids; so that the salts of the more 

 soluble and more fusible acids are also more easily soluble than 



