Examination of the Diopside of Fassa in the Tyrol. 357 



The composition of the mussite indeed, according to Lau- 

 gier*, differs considerably from that of our diopside : we might, 

 however, presume that this difference partly arises from the 

 less perfect state of chemistry with respect to those substances 

 in Laugier's time. It is possible, too, that the same circum- 

 stance has produced the smaller difference from the composi- 

 tion of our mineral which appears in the analysis of the ma- 

 lacolite or sahlite examined by Vauquelin f. 



Among the other existing analyses of minerals referred to 

 pyroxene or augite, according to which other formations of 

 augite-substance are proved, we must consider, with respect 

 to the diopside of Fassa, several examinations made by Von 

 Trolle Wachtmeister Hisinger, Von Bonsdorf, and H. Rose. 

 From the comparison of the results of these analyses enume- 

 rated in the well-known treatise of Professor Rose, " On the 

 Pyroxene J," with those of the analyses just-mentioned of Lau- 

 gier and Vauquelin, and with those obtained by me on the 

 composition of the diopside of Fassa, for which purpose I have 

 prepared the following table ; it seems that all the minerals 

 thus examined, may be referred to the diopside, and their com- 

 position expressed by the formula CS 3 -f MS 2 . 



* Ann. du Mus. d'Hist. Nat. torn. xi. p. 153. 



JHaiiy, Traite de Mincralogie, 1st edit. vol. iv. p. 382. 

 Schweigger's Journ.f. Chem. u. Phys. Band xxxv. p. 86. &c. 



LVI. De- 



