118 British Association for the Advancement of Science. 



the same time, made the depositories of the chemical affinities 

 of the chlorine and hydrogen respectively. Mr. G. proposed to 

 modify this theory so far as to abandon the idea of electricities 

 being actually possessed by these bodies, and to refer the phe- 

 nomena at once to the proper chemical affinities of these bodies. 

 He assigned similarly polar molecules to the exciting fluid and 

 metals ; and taking hydrochloric acid as a type of exciting fluids, 

 he gave to each molecule a pole, having an affinity resembling 

 that of chlorine, or chlorous affinity, — of negative electricity ; and 

 another pole, having an affinity resembling that of zinc and hy- 

 drogen, or zincous affinity, instead of positive electricity. He 

 pursued the subject to a considerable length, illustrating his views 

 by means of diagrams. 



Dr. George Wilson gave an experimental demonstration of the 

 certain existence of haloid salts in solution. All previous attempts 

 to decide the question whether haloid salts do or do not decom- 

 pose water, when dissolved in it, have afforded no certain results. 

 The object of this paper is to show, that although the inquiry 

 had long been abandoned as hopeless, a demonstration can be 

 given of the persistent haloid condition of the dissolved haloid 

 salts of the electro-negative metals. This the author appears to 

 have satisfactorily demonstrated. It is mentioned as an inciden- 

 tal conclusion from the experiments recorded, that they afford a 

 direct proof of the quasi-metallic character of hydrogen, so much 

 insisted on by the advocates of the binary theory of salts ; and 

 that they supplied more direct evidence than any previous trials 

 regarding this, since they not only demonstrate hydrogen to have 

 the power of displacing many metals, but at the same time assign 

 to it, as its proper place in its metallic character, a position inter- 

 mediate between the electro-positive and electro-negative metals. 



A paper was offered by Dr. S. Brown on the Crystallization of 

 Carburets; having for its object to lay down a new form of the 

 maxim of crystallization, viz. that when particles of a solid body 

 are slowly evolved from the decomposition of a substance of 

 which it, or its elements, are chemical constituents, they cohere 

 in crystal, and that independently both of the fusion (or solution) 

 of the body crystallized, and of the presence of any fluid medium 

 of molecular action whatsoever. Dr. B. had obtained small crys- 

 tals, colorless and intensely hard, of the carburets of iron, copper, 

 zinc, lead, &c. 



