3P6 



On the Crystalline Structure of the 



[Apr It 



ception of the polarity of matter, an instance of which in a great scale, 

 is given in the case of the magnetic needle, the polarity of which is now 

 considered due (o its electrical condition. Now the phenomena of crystal- 

 lization entitle us to infer, that there is something like a definite polarity 

 in every particle, by which it is compelled to turn in a given direction, 

 and to group itself with other particles in definite forms — the polarity 

 in the "glaring instance" is due to electricity— may we not reasonably, 

 from the above remarks, infer the same cause, to produce a like 

 effect, in an instance, less under the immediate cognizance of 

 our senses. 



By reference to some observations I made about a year ago,* I 

 find a remarkable illustration of the above opinions, noted as hav- 

 ing occurred during the crystallization of fused sulphur. On the 

 vessel, in which the sulx)hur was melted, being removed from the furnace, 

 and allowed to cool, the upper surface of the mass became covered with 

 thin needle shaped crystals, about one-eighth of an inch in length, and 

 about the thickness of hairs. To these crystals, it seemed as if a power of 

 spontaneous motion had been communicated, since they flew about in all 

 directions, first from one side of the vessel to the other, then back again, 

 then across, and indeed they kept unceasingly on the move. On close 

 examination, I found all the phenomena of polarity exhibited by these 

 small bodies toward each other, and on watching two, I observed them 

 gradually approaching each other, till they almost seemed in contact, 

 then, suddenly, both started back from each other to some distance. 

 Turning round they approached each other again, apparently with those 

 .sides turned towards each other, which admitted of the attractive force 

 coming into play, for they would rush together, and form what then 

 seemed to be but one crystal. This process was going on throughout 

 the whole, and this alternate advancing and retreating was the cause of 

 the incessant motion. The forms of the acicular crystals were quite 

 different from those resulting from their continued aggregation, the one 

 being long and thin, the other, bright prisms of nearly equal length and 

 breadth, and from one-quarter to half an inch in thickness. This remark is 

 quite agreeable to the researches of crystallograpliers, who have found 

 that such thin crystals following certain rules of superposition and ranged 

 in a certain order, produce others of entirely ditFerent forms. 



I will not enter further upon this point, but I trust the few remarks 

 I have made will not be altogether devoid of interest, shewing as they do, 

 the connection subsisting between the electrical condition of the parti- 



* These were made in the laboratory of Mr. K. T. Kemp, to Avhoiu I bflicve the 

 credit haviug first leiaarlit'd the §iasular phyacuieua is tlue. 



