On the Quantily of Carlon in Carlonic Acid, &c. 3 1 5 



in which we do not discover any mutual relations of parts, 

 or of distinct forms to the subsistence of other parts or forms. 

 They are not formed by gradual growth. 'I'heir period of 

 duration appears to have no fixed limit. Their particles 

 unite by mutual attractions ; and after separation by external 

 force, are found to reunite as perfectly as before such sepa- 

 ration. They are chiefly distinguished one from another by 

 variety of colour, difference of transparency and opacity, 

 weight, hardness, ductility, fusibility in heal, difference 

 of mutual attractions; by the sound caused in their con- 

 cussion, their smell and taste, their peculiarity of frac- 

 ture, and by the regularity of solid forms which they are 

 severally found to assume, after solution, in assignable de- 

 grees of temperature. The ordinary visible characteristics, 

 colour, gloss, fracture. Sec, recorded by Werner; the 

 crystallme forms enumerated by Haiiy ; the weicht and 

 mutual attractions ascertained by various philosophers and 

 chemists, are to be found collected logether in several mo- 

 dern Treatises on Mineralogy, and should accompany the 

 reference to each specimen in the Catalogue of the National 

 Museum. 



XLVII. On the Quantily of Carbon in Carbonic Acid, and 

 on the Nature of the Diamond. By William Allen, 

 Esq. F.L.S. and William Uasledink Pkpvs, Esq, 



[Continued from p. 2l.'7.] 



Second Experiment on Diamond. 



J. HERMOMETKR 48° Fahrenheit, barometer 30-08. Oxy-r 

 gen gas made as usual, left a residuum of 3 parts in 100. 



Eleven small diamonds, weighing 4*0 1 grains, were put 

 into the tray. We began with 49-84 cubic inches of oxy- 

 gen ; and every thing being properly adjusted, kept the 

 platina lube red-hot for a quarter of an hour, and during 

 (his time the gas was passed from one gasometer to ths 

 other, as in the former experiments. When the tubes, ?cc. 

 ',vtre cooled down to the temperature of the room, all the 



uas 



