1320.] M. Griiner Ober-Berg on Cakstine. 283 



radical has never yet been separated, it is clear that this acid 

 can only contain a quantity of oxygen eqnal to that contained in 

 the base. In that case, fluoric acid will be composed of 



Fluorine 27-22 100-00 



Oxygen 72-78 262-84 



( To be continued.) 



Article VII. 



A Chemical Aualt/sis of the C(destine (Sulphate of Strontian) 

 found at i^'urteu, not fa?' from Hanover.* By M. Gruner 

 Ober-Berg, Conimissair in Hanover. 



Though the neighbourhood of Hanover is rather poor in 

 minerals, yet there has lately been observed caelestine both in 

 crystals and v.eathered in a quarry opened for procuring mateiials 

 for mending the roads. I have analysed several of these speci- 

 mens, and have obtained results indicating that they constitute 

 anew variety of sulphate of strontian. 



The place where tliis mineral is found is at a village called 

 Norten, about two hours' journey from Hanover, where the 

 quarry containing the sulphate of strontian is opened at the foot 

 of a mountain. The rock in which it occurs is a large grained 

 floetz limestone, v/hich contains here and there petrified encrini 

 and nummuli, and thin veins of galena. The sulphate of stron- 

 tian hitherto observed passes through the limestone in three 

 perfectly parallel beds (Trummen), distant from each other from 

 24 to 30 inches, and inclined at an angle of fiom 60° to 70°. The 

 breadth of these beds does not exceed two inches. In the first 

 of these beds, the mineral occurs in a crystallized state; while 

 in the second and third it has a weathered aspect ; and in the 

 third bed this has gone so far that the mineral has an earthy 

 aspect. The first bed is highly impregnated with c/ai/ iron 

 hydrate, by which the strontian contained in it is coloured 

 brownish-red. Besides, in these three beds, sulphate of stron- 

 tian is found likewise scattered through the limestone in fine 

 feathery crystals. 



The whole of the first bed is filled with the strontian, which 

 has a foliated or radiated texture, and a silky lustre. Its colour 

 is usually milk-white, but here and there it passes into blue. In 

 the second bed, the strontian still retains its form ; but it has 

 quite lost its lustre and its colour. The change is still more 

 conspicuous in the third bed where the strontian has lost its 

 form likewise. 



* Trantilalei] from Gill)cr('i> Annalrti, vol. Ix, p. T2. 



