Mr Haidinger on Mesole. 19 



sent him by Dr Brewster, the results of his analysis being 

 such as would not allow him to comprise the mixture of the 

 new mineral within any one of the chemical formulas designed 

 to express the mixture of other species. The varieties sent 

 had not been selected for the purpose of analyzing, this mine- 

 ral, which was not then thought to be anything new, but for 

 the apophyllite, which is often found associated with it ; and 

 it is not surprising, therefore, that the natural-historical pro- 

 perties of the mesole, as well as of the mesoline, as far as they 

 could be ascertained in those specimens, were not sufficient 

 for removing every doubt respecting their existence as species 

 independent of others. 



In my translation of the Treatise of Mohs, * I hinted at 

 the probable identity of mesoline with a particular kind of 

 chabasie, which I had seen in many of the specimens of Mr 

 Allan's cabinet, accompanying mesole, stilbite, and apophyllite. 

 Berzelius himself arrived at the same conclusion by chemical 

 arguments, -f The description of mesole was given partly 

 from Berzelius' paper, partly from some specimens of the 

 same variety in Mr Allan's cabinet. But only very few of its 

 properties were ascertained, and the knowledge of the species 

 itself is therefore so imperfect, that from the mere description 

 it could not be distinguished from many varieties of other spe- 

 cies, and must be then comprised in the appendix. 



Though even now I cannot pretend to offer a perfect de- 

 scription, the more accurate indication of the regular forms 

 still being a desideratum, yet the new varieties which I have 

 lately had an opportunity of examining are such, that the 

 place of the species of mesole in the system of Mohs may be 

 fixed with precision. These varieties show a very great re- 

 semblance to certain kinds of apophyllite, so much so, that 

 Sir Charles Giesecke, who discovered them in the island of 

 Disco, in Greenland, was induced to consider them as a parti- 

 cular subspecies of it, the micaceous apophyllite. There are 

 several specimens of the same mineral in Mr Allan's cabinet. 

 These I had placed two years ago in the genus Kouphone- 

 spar, without, however, referring them to any particular spe- 



• Vol. iii. p. 127. t Arsberattehe for 1825, p. 211. 



