44 PROBABLE ACTION OF THE 



capable of assuming two or more different states ; and 

 that sulphur, selenium, phosphorus, and arsenic, are 

 susceptible of these remarkable changes in which, with- 

 out the slightest variation in the chemical character, a 

 complete change in the physical condition is produced. 

 Copper, iron, tin, and manganese, are known to exist in 

 at least two states of physical dissimilarity, aud many of 

 the rarer metals exhibit the same peculiarity.* Hence, 

 may we not infer that some of those substances, which 

 we now term elementary, are but altered conditions of 

 the same element ? The resemblance between many of 

 those bodies strengthens the supposition. Iridium and 

 platinum, iron and nickel, chlorine, bromine, iodine, 

 and probably fluorine, are good examples of these 

 similarities, although these bodies are all distinguished 

 by physical and chemical differences. 



The light-refracting gem, which glistens on the neck 

 of beauty, and is valued for its transparency, differs only 

 from the rude lump of coke in its molecular arrange- 



* Copper, when reduced by hydrogen at a heat below that of 

 redness, on exposure to air soon becomes converted throughout 

 its mass into protoxide ; and when it is triturated for some time 

 with an equivalent quantity of sulphur, it combines with it 

 according to Boucher's experiments, producing flame, and form- 

 ing sulphuret of copper. If, however, the copper be reduced by 

 hydrogen at a red heat, still considerably below the temperature 

 at which it softens and begins to melt, it remains for years un- 

 changed by exposure to air, and cannot be made to combine 

 with sulphur without the application of heat. Iron, cobalt, and 

 nickel, when reduced by hydrogen below a red heat, inflame after 

 they have cooled, if exposed to the air ; and if they are imme- 

 diately placed in water to avoid their taking fire, they inflame 

 when they are again removed, and have become nearly dry. If 

 we compare this behaviour with that of iron reduced by heat, 

 and with iron in that state in which it forms the conductor oi" 

 a galvanic current without becoming oxidized, it would appear 

 that these peculiarities depended upon something more than a 

 difference of mechanical condition." Berzelius on, the Allotropy 

 of Elementary Bodies. See On /he Isomeric Conditions of the Per- 

 oxide oj Tin: by Prof. H. Rose. Chemical Gazette, Oct. 184s. 



