42 CHEMICAL PHENOMENA. 



In these instances a large quantity of heat is rendered 

 sensible, as if it had been squeezed out by the force 

 with which the particles combined, from insterstices, 

 which were filled with, what we may be allowed to call, 

 an atmosphere of heat. Hence we conclude that, 

 amongst the influences determining the molecular con- 

 stitution of a body, heat performs an important part. 

 All these facts go to prove that the atoms which form 

 the compound body, whatever may be its character, are 

 disposed of as so many centres of force, which act by 

 influences of a peculiar character upon each other. That 

 these influences are dependent upon known physical 

 forces is certain ; but the laws by which the powers of 

 the ultimate atom are altered remain still unknown. 



In the great operations of nature, changes are pro- 

 duced which we cannot understand, and variations of 

 condition do certainly occur, which may be regarded as 

 instances of transmutation. 



Amongst others, we may adduce the different states 

 in which we know carbon to exist. We have the 

 diamond with its beautiful light-refracting property, its 

 hardness and high specific gravity, capable of being con- 

 verted into graphite and coke.* Charcoal, graphite, and 

 the diamond, are totally unlike each other, yet we know 

 they are each composed of the same atoms. Charcoal 

 is a black irregular substance, light, and readily inflam- 

 mable ; graphite is crystallizable ; but the forms of its 

 crystals cannot be referred to those of the diamond, and 

 it burns with difficulty. The diamond occurs in the 

 most regular and beautifully transparent forms ; and it 

 can be burned only at the highest artificial temperatures. 



* The conversion of the diamond into graphite and coke was 

 first effected by the agency of the galvanic arc of flame, by M. 

 Jaqnelini, and communicated to the Academy of Sciences in 1847, 

 in a Memoir entitled, De Faction calorifique de la pile de Bunsen, 

 du, chalumeau a gaz oxygene et hydrogene sur le carbon pur, artificiel 

 et naturel. See Comptes Rendus, 1847, vol. xxiv. p. 1050 ; also 

 Report <f the British Association, for 1817, (Transactions of Sections) 

 p. 50. 



