PHYSIOGRAPHY. CLASS II. 



Compound Varieties. Massive : composition 

 granular, of various sizes of individuals, sometimes 

 elongated in one direction or wedge-shaped, and 

 passing into columnar ; generally strongly coherent. 



OBSERVATIONS. 



1. The varieties of the present species have been disco, 

 vered at various periods, and in different kinds of reposi- 

 tories. Some of them indeed, at first sight, appear so 

 little resembling each other, that it is not to be wondered, 

 that they were considered as particular species ; for in order 

 to be certain in these determinations, a superficial inspection, 

 or some information of the mode of occurrence or accom- 

 panying minerals, cannot suffice ; even experiments before 

 the blowpipe or the chemical analysis do not give that high 

 degree of evidence which arises from an accurate examina- 

 tion of the physical properties of minerals, of their form 

 and cleavage, hardness or specific gravity; and this be- 

 comes the more indispensable, if, as in the present case, 

 the different varieties bear to each other but a slight degree 

 of resemblance. Whatever may be the consequence of 

 these examinations, it must always be a true, correct, and 

 constant result, because it is founded upon those things 

 which are constant in the productions of nature, their phy- 

 sical properties. Mcionite contains the purest and most 

 transparent varieties of the species of a white colour ; and 

 it seems by these characters to be perfectly distinguished 

 from the rest. Yet the varieties of Scajjolite from Finland, 

 described by Mr NORDENSKIOLD, and those brought from 

 Greenland by Sir CHARLES GIESECKE, possess the same pro- 

 perties, though less distinctly, and unite Meionite with the 

 rest of the varieties of Scapolite, which generally possess 

 greenish colours, either pale and a little translucent, or dark, 

 and then the crystals are very often nearly opake. Some of 

 its varieties are coloured red, probably by oxide of iron. Upon 

 this difference of colour, the division into red and grey Sea- 



