74 INFLUENCE OF FORCE ON PART r. 



are wholly the result of the forces by which the atoms 

 are held together; but these phenomena may rather be 

 said to depend upon a reciprocal action between an 

 irregular molecular structure and the agency of light and 

 heat : which indeed seems to be confirmed by the transit 

 of these two forces through right and left-handed quartz, 

 for there is no reason to believe that there is any dif- 

 ference in the form of the particles in these two crys- 

 talline substances. 



The experiments of M. Becquerel show that electricity 

 ,is a power which makes the atoms of matter aggregate 

 in crystalline forms ; for he has succeeded in forming 

 crystals of gold, silver, cobalt, nickel, platinum, and a 

 variety of the gems undistinguishable from those in 

 nature, by exposing saturated solutions of these sub- 

 stances for a very long time to feeble voltaic electricity ; 

 and crystals of earthy matter have been obtained in the 

 same manner. The electric and magnetic state of 

 mineral veins in mines which contain a vast variety of 

 crystals, metallic and non-metallic, strongly favours this 

 view of the origin of crystalline form. 



M. Eegnault has proved that the ratio between the 

 specific heat and the weight of the atoms of matter is 

 intimately connected with the mode of their aggrega- 

 tion; and indeed if it be considered that the atoms have 

 not only specific heat and weight, but specific affinity, 

 electricity, magnetism, consequently polarity, and pro- 

 bably specific forms, these peculiar forces must neces- 

 sarily influence the structure of crystals according as 

 they combine with or oppose the natural or artificial 

 forces acting upon them, or upon their dissimilar faces, 

 and this may be the cause of the great variety of forms 

 that matter appears under. Carbonate of lime alone 

 assumes more than 1,200 different modifications of its 

 primitive type, but whatever be the variety of forms 

 which any one substance may take, they are found to 



