1824 .J M. Rose on Analcime, Copper Pyrites, Sfc. 353 



It was my intention here to extend the theorems I have 

 published in my theory of evaporation, and to add some new 

 ones since discovered respecting the " conducting power " of 

 gases, the agreement of which with the experimental laws of 

 Dulong and Petit, contributes another strong link to the chain 

 of evidence adduced in favour of my views ; but as I may at some 

 period print something in a separate form on the important 

 subjects I have discussed in various parts of the Annals, 1 intend 

 to reserve these, and other things which I have been able to 

 effect in different parts of the physical sciences, to that oppor- 

 tunity. 



Article VI. 



Chemical Examination of Analcime, Copper Pyrites, and Sul- 

 p/utret of Bismuth. By M. Rose.* 



The first research into the composition of analcime was made 

 by M. Vauquelin. He found this mineral to contain 



Silica 58-0 



Alumina 18-0 



Water 8o 



Soda. 10-0 



Lime 2-0 



Iron Trace 



96-5 



The analcime which I analyzed is found in the valley of Fassa, 

 in the Tyrol; the crystals were trapezoidal, and were in some 

 parts of a slight red colour; but the analysis indicated scarcely 

 perceptible traces of oxide of iron : the crystals were translucent, 

 and free from other impurities. The analcime reduced to pow- 

 der, lost, by being strongly heated, 8-27 per cent, of water, 

 which was slightly alkaline. By heating some fragments to 

 redness, ths loss in different experiments amounted to 8*80, 

 8-86, and 8-96 per cent. The analcime lost its transparency, 

 and became a white enamel. 



The analysis of analcime is not complicated, since it is very 

 easily decomposed by acids, when it has not been heated, and 

 is reduced to powder. On this account it is not requisite to 

 employ nitrate of barytes used by M. Vauquelin, and which 

 always occasions more or less loss. When digested in muriatic 

 acid, it formed a jelly, which was dried, and afterwards treated 

 with muriatic acid diluted with water to separate the silica. The 

 filtered solution contained neither lime nor magnesia, and was 



• Extracted from the Annalcs de Chimie et de Physique, torn. xxv. p. 192. 



New Series, vol. vn. 2 a 



