106 M. Scheerer's Observations on Elceolitli and Nepheline. 



then no elaeoliths from other localities at my disposal with 

 which to test the truth of my assertion, and I was consequently 

 obliged for the moment to lay all further inquiry aside. Sub- 

 sequently, however, I re-commenced these investigations, 

 partly in Norway and then in Berlin, in the laboratory of Pro- 

 fessor Heinrich Rose, and with the kind assistance of Mr. W. 

 Francis, I have performed a new series of analyses of elaeoliths 

 and nephelines. The results which I have obtained, as well as 

 some other observations, I will communicate in the present 

 paper, and at the same time I will add for comparison the 

 analyses of these minerals, which had been previously made by 

 other chemists. 



I. ANALYSES OF VARIOUS ELAEOLITHS. 



1. Brown ElfEolith from Brevig in Norway. I have already 

 communicated the composition of this elseolith in the memoir 

 above-mentioned, but for the sake of completeness I will re- 

 peat it here. It was found, from three analyses, to consist of 



1. 2. 3. 



Silica ..... 44-59 44-48 44-30 



Alumina .... 32-14 32-03 31-60 



Peroxide of iron . 0-86 1-30 1-16 



Lime 0-28 0-24 0'32 



Soda 15-67 15-76 



Potash .... 5-10 5-24 



Water .... 2-05 2-06 2-10 



100-69 101-11 99-93 



The specific gravity of this elasolith is 2'617. It occurs in 

 smaller or larger masses in a snow-white granular albite, and 

 is in general so much impregnated with it that it is exceedingly 

 difficult to obtain pure fragments for analysis. Hence on 

 dissolving the silica in carbonate of soda some powdered albite 

 always remains. This latter mineral being scarcely in the 

 slightest degree attacked by acids, I do not believe that it 

 has had any sensible effect on the analyses. 



2. Green Elceolith from Fredriksvarn in Norway. This 

 species of elaeolith occurs, like the following, in the well-known 

 zirconiferous syenite of Fredriksvarn. Its specific gravity was 

 found to be 2-61. Klaproth* was the first who undertook an 

 analysis of this mineral, and obtained the following results : 



* Klaproth's Contributions, vol. v. p. 170. 



