SCIENTIFIC. SOCIKTY OF LONDON. 



191 



mineral productions, which is further evinced by the ordinary 

 compounds, as follows ^ — 



Iodides alhed to oxygen, are red. 



Muriates allied to hydrogen, are blue. 



Nitrates allied to nitrogen, are greenish. 



Chlorides allied to chlorine, are greenish blue. 



Sulphurets allied to ?, are yellow. 



Sulphates allied to oxygen and hydrogen, are dark blue 

 approaching purple. 



And many of these are materially affected on their being 

 subjected to extraordinary influences. 



This system of colours would, therefore, assign to minerals 

 an arrangement according to their composition ; the simple 

 forms, or, in other words, the most pure substances, occu- 

 pying the respective positions of equi-distant radii of a circle, 

 between which numerous other radii, determined by the 

 colours presented, would be subsequently placed. This, 

 how^ever, is merely an illustration of the arrangement ; but 

 as it has long ago been determined that to define such dis- 

 tinct line of demarcation is impossible, on account of the 

 gradations throughout nature, so, in all probability, will 

 these colours range in circles, one within the other, accord- 

 ing to the equivalents of their composition, and hence their 

 colour. Again, as it is clear that all colours are reducible to 

 three, so it is, also, that as no one law of nature can nullify 

 another, the system must reduce itself into one, composed 

 of three grand families, of which oxygen, hydrogen, and ni- 

 trogen (?) are the probable types. 



The author concluded the second paper by expressing a 

 hope, that having called attention to this beautiful series of 

 analogies, chemists as well as mineralogists might contribute 

 to the identification of some rule, founded upon this or other 

 equally broad basis ; and that he hoped, at some future time, 



