Intelligence and Miscellaneous Articles. 237 



with haydenite, which constitutes a large portion of the rock, iron 

 pyrites, brilliant black rhombic crystals of carbonate of iron, some- 

 times with green hornblende or white stilbite, possessing the usual 

 form of the crystals of stilbite. 



The density of beaumontite was found to be 2*24, which is very 

 near 2*25, that of epistilbite ; when heated in a glass tube it yields 

 water, becomes white, swells much, and becomes powdery; on 

 the platina wire it produces a white opalescent pearl ; with salt of 

 phosphorus it fuses readily into a glass, in which a skeleton of silica 

 floats, and which indicates a little iron ; with carbonate of soda lively 

 effervescence ensues, and the fusion becomes perfect. 



Beaumontite resists the action of acids, which appears to be in- 

 consistent with its characters before the blowpipe, they being those 

 of the zeolites ; thus it is not acted upon by dilute nitric acid, and 

 it is with difficulty attacked either by hydrochloric or sulphuric acid 

 after calcination. When, however, it is reduced to a very fine 

 powder, and treated before calcination with concentrated hydro- 

 chloric acid, it is completely decomposed, and the silica is separated 

 in a granular state. 



The qualitative examination proved that the mineral contains 

 water, silica, alumina, oxide of iron, lime, magnesia, and a little soda ; 

 sulphur, which might be suspected on account of the pyrites, was 

 sought for in vain. 



The honey-yellow variety was selected for quantitative analysis ; 

 appeared to contain more lime than the greenish yellow, in which it 

 is replaced by magnesia ; as this mineral becomes perfectly white by 

 calcination, it is easy to remove by this operation any small portions 

 of foreign matter which may have escaped the first trial; the cal- 

 cined mineral was first subjected with carbonate of barytes to the 

 heat of a forge ; the silica was determined in the usual way, and dis- 

 solved totally in potash ; the alumina, precipitated by ammonia after 

 adding the hydrochlorate. was afterwards dissolved in j)otash ; the 

 portion of the precipitate which was insoluble was treated with di- 

 lute sulphuric acid ; the oxide of iron was precipitated by ammonia, 

 and the mother- water, containing a little magnesia, was set aside. 

 The lime was precipitated in the state of oxalate, and the sulphates 

 were converted into carbonates by means of the acetate of barytes ; 

 on treatment with water the magnesia remained, and by evaporation 

 traces of carbonate of soda were obtained. The insoluble portion, 

 containing the magnesia, was treated with dilute sulphuric acid, and 

 the solution added to the mother-water containing magnesia, the 

 total quantity of which was determined in the state of phosphate. 

 The results of the analysis w r ere — 



Silica 64-2 



Alumina 14-1 



Lime 4'8 



Magnesia 1*7 



Protoxide of iron. . 1'2 



Water 13'4 



Soda and loss .... '6 



100- 



