456 THE CANADIAN NATURALIST. [DeC. 



of a few years, in the monoclinic sulphur or the yellow iodide of 

 mercury ia a few seconds. 



3. Chemical Analysis of the Rock. 

 By F. L. Ekman. 



The following are the results of an analysis of various speci- 

 mens of Nullaberg-rock from the mineralogical collection of the 

 Royal Academy of Science in Stockholm. 



The principil ingredient in this species of rock was fels^par, a 

 portion of which formed colourless stripes, coarser or finer, in 

 the fracture of the dark stone. Even the dark material itself 

 was chiefly composed of felspar, which however was so thickly 

 overspread with small grains of organic carbonaceou-* matter, as 

 entirely to conceal the appearance of the felspar. These grains 

 were in part visible to the naked eye, and when a little of the 

 dark stone was crushed between glass plates under the microscope, 

 the carbonaceous substance appeared as opaque, angular broken 

 particles, and the felspar uncoloured ; one or two flakes were 

 slightly tinged with yellow. 



Mica appeared thickly scattered in separate or conglomerate 

 scales. Quartz I could not observe. 



Carbonate of linje occurred together with felspar in the small 

 round balls of white colour, copiously sprinkling some of the 

 specimens, though in some instances it had been fretted out by 

 the action of the air and water. It sometimes appeared, less 

 visibly, mixed with the remaining mass, but was sometimes entirely 

 absent. 



In five specimens of diSferent character I found the following 

 proportions of organic matter (traces of water included) and 



carbonate of lime : 



1, 2. 3. 4. 6. 



Organic mat t<r 7.10, 10.67, 10.36, 5.44, 9.08. 



Carbonate of lime.... 2.57 (0,07) 14.30 2.75 0.00. 

 The following is the analysis of the rock, wiieii fr^e fiOiu 

 organic matter and carbonate of lime : 



1. 5. 



Silica 65.03 65.25. 



Alumina 19. 61 



Red Oxyd of Iron 0.45 



Lime 0.19 



Magnesia 0.20 



Potash 14.46 



Soda 1.06 



101.00. 



