Description and Analysis of Emmonite. 417 



We have from the nitrates 65 x + 3-5 y + 6-75 (.? + y) = 

 139; or, 



13-25*+ 1025 y = 139&x = 139 ~ 10 ' t25 y 

 17 13-25 



From the carbonate 6 ox + 3-5 y + 2-75 (x + y) =95-21; or, 



9-25 x + 6-25 y = 95-21 & a: = 95 ' 21 ~ 6 ' 25 . ? / 

 ^ 9-25 



139 - 10-25 y = 95-21- 6-25 y, 4 . , , 



— io. t jr qTqk b y equating the two values 



of.r. 



24-22 



From this we deduce y = ""~ = 2 very nearly 



Hence, . . . x = 8-94 

 Consequently, the lime in 100 grains of mineral is 7 grains, 

 and the carbonate of lime 12-5 grains. 



The strontian in 100 grains of the mineral is 58*11 

 grains, and the carbonate of strontian 8269. 



Hence the constituents of the mineral are, 



Carbonate of strontian, . 82-69 



Carbonate of lime, . . . 1250 



Peroxide of iron, . . . 1-00 



Zeolite, 3-79 



99-98 



The peroxide of iron and zeolite being foreign matter, it 

 is obvious that the pure mineral is a compound of 

 2 atoms carbonate of lime, . 12*5 

 9 atoms carbonate of strontian, 83-25 



95-75 

 It constitutes a new species of calcareo-carbonate of stron- 

 tian, which we may distinguish by the name of Emmonite, 

 from Professor Emmons to whom we are indebted for our 

 knowledge of it. 



This with the two species of carbonate of strontian de- 

 scribed in my Mineralogy (vol. i. p. 107.) constitute the 

 three following species, 



1. Green carbonate, 10 Str C + Cal C 



2. Brown carbonate, 7 Str C + Cal C 



3. Emmonite, . . 9 Str C + 2 Cal C or 



4J Str C + Cal C 



VOL. III. 2 E 



