'i 6 SULPHUE. PARTI. 



cilable with one another : and thus carbon possesses 

 the property of being dimorphous. 



Sulphur is a simple inflammable mineral abounding 

 in volcanic countries, either in a crystalline or amor- 

 phous state, and forming a constituent in organic 

 substances, animal and vegetable. It is readily dis- 

 solved by bisulphide of carbon, by benzine, and by 

 a moderate heat; and copper filings exposed to its 

 vapour spontaneously take fire, the chemical force of 

 combination merging into light and heat. Sulphuretted 

 hydrogen gas, a combination of sulphur and hydrogen, 

 forms naturally during the putrefaction of organic 

 matter, and Mr. Faraday observes with regard to the 

 affinities of sulphur, so numerous are its relations, 

 so extensive its range of combinations, that we must 

 consider it to be the very foundation on which chemical 

 manufacture is built up.' 



Though a simple substance, sulphur exhibits the two 

 remarkable phenomena of dimorphism and the allo- 

 tropic property. When reduced by heat to vapour and 

 cooled slowly, it crystallizes in rhombic octohedrons ; 

 when merely melted and allowed to cool slowly, it takes 

 the form of oblique rhombic prisms. Here the same 

 atoms when in vapour and in a liquid state are acted 

 upon by different forces ; but however that may be, 

 sulphur is another singular exception to the law of the 

 immutability of the crystalline systems. 



Sulphur becomes allotropic by -the continued appli- 

 cation of heat ; that is to say, it entirely changes its 

 appearance and character, though it remains chemically 

 the same. Naturally it is yellow and brittle, but when 

 fused, it is a colourless pellucid fluid which by continued 

 heat is changed into a black tenacious substance that 

 becomes like India rubber or gutta percha when thrown 

 into water. In this allotropic state it is endowed with 

 properties more powerful, energetic, and exalted ; its 



