1871.] SCOTT AEGTLLSHIEE MUfEEAlS. 375 



Of these, A is by Damour ; it is of Harmotome, the opaque va- 

 riety. B, by Bammelsberg, is probably of the same ; it is simply called 

 Harmotome from Strontian by him. C is by Damour ; it is one of 

 two analyses of Morvenite, by which he established the identity of 

 Morvenite with Harmotome. D is Dr, Reynolds's analysis. 



From this it appears that these crystals are a particularly pure form 

 of the mineral, being nearly perfectly free from alkalies ; and they 

 certainly deserve a name, to the full as much as Thomson's Morve- 

 nite does. 



The only special interest which they possess is crystallographical. 

 In all the crystals of Harmotome figured by either Dufrenoy or Dana 

 the termination of the prisms is quadrifacial. Dufrenoy mentions 

 that occasionally a very obtuse quadrangular pyramid is found, simi- 

 lar to that which sometimes occurs in Anatase ; and Descloiseaux, 

 in his recent paper* on the crystallography of the species, has deter- 

 mined the angle between the opposite faces of this pyramid to be 

 178° 20'. Dana gives in his last edition such a pyramid. 



I have not myself been able to measure the angle between the 

 faces of the dihedral termination of the prisms which I now submit 

 to the Society ; it is an extremely obtuse one ; and it seems probable 

 that they will ultimately turn out either to be two of the four faces 

 spoken of by Descloiseaux, or else the faces of the brachydome cor- 

 responding to that pyramid. 



In conclusion I would only draw attention to the specimens which 

 I have brought down, as evidence that the neighbourhood of Strontian 

 is still almost as promising a field for the mineralogist as any in these 

 islands. 



DlSCTTSSION. 



Mr. "W. "W. Smyth mentioned the wonderful collection of minerals 

 from Strontian which had been brought to the Great Exhibition of 

 1851, which gave a most striking idea of the mineral riches of the 

 locality. The occurrence of such a series of different substances in 

 one locality in the gTanite was almost unparalleled, though in the 

 Andreasberg mines, in clay slate, they were to some extent rivalled. 

 The features, however, differed in the two places, more silver and a 

 greater number of zeolites being present in the Hartz mines. 



Mr. D. Forbes observed that Harmotome occurred also at the 

 Kongsberg silver-mines in Norway, at a distance from granite. He 

 thought it remarkable that these crystals of peculiar form occurred 

 in the same spot and in connexion with crystals of the same sub- 

 stance but of the ordinary form. 



Mr. Davis remarked that Celestine was also to be placed on the 

 list of the minerals from Strontian. Harmotome had been found in 

 the same form of double crystals at Bodenmais in Bavaria. 



Mr. Scott stated, in reply to a question from the Chairman, that 

 the mineral had not been as yet optically examined, but that if he 

 could procure more of it he should be happy to place it at the dis- 



* Ann. des Mines, 4th ser. torn. ix. p. 339. 



