1823.] Scientific Intelligence. 395 



crystallised, and that the many crystals which it presents should not 

 have been noticed. The varieties of forms of cleavelandite are, how- 

 ever, at least as numerous as those of felspar ; the crystals are very 

 distinct, of various sizes, but rather large than small ; they are very 

 frequently marked parallel to one of the primitive planes, viz. that 

 which is the least easy to obtain by cleavage. Several of the forms 

 greatly resemble some of the varieties of felspar, being composed of 

 the same number of planes disposed in the same manner, and it is only 

 by using the goniometer that the difference can be perceived. Not- 

 withstanding this great analogy, Mr. Levy believes that the forms of 

 the two substances are incompatible. He considers the primitive of 

 felspar to be an obhque rhombic prism, and not a doubly oblique 

 prism, as it had been supposed by Hauy, and he takes for the primitive 

 of cleavelandite a doubly oblique prism. The crystals of cleavelandite 

 are generally white, sometimes yellowish and reddish ; they are trans- 

 parent, sometimes translucent and opaque, and have a certain bril- 

 liancy which does not belong to felspar. Both substances are often 

 found upon the same specimen, and sometimes both in large and well 

 defined crystals. The localities of cleavelandite are very numerous, 

 and this substance seems likely to become one of the most important 

 both in mineralogy and geology. All the rocks of which felspar is 

 considered as a component part, must be re-examined to separate those 

 which really contain felspar, from those which contain cleavelandite. 

 The localities derived from Mr. Turner's collection are the following : 

 Dauphiny, St. Gothard, Tyrol, Piedmont, Baveno, Elba, Vesuvius, 

 Saxony, Sweden, Norway, Siberia, Greenland, United States, and Rio 

 di Janiero.* 



The finest crystals come from the Tyrol and from St. Gothard. The 

 largest from Siberia, where they are met upon the same specimen with 

 large crystals of reddish felspar, and smoky quartz. The most trans- 

 parent come from Dauphiny, where they are met in small transparent, 

 brilliant, macled crystals, with chlorite, quartz, and occasionally felspar 

 ditetraedre. Specimens of this locality are very commonly met with 

 in collections, and the crystals they contain were described by Hauy 

 as felspar quadridecimal. At Baveno, it sometimes forms the guangue 

 of the fine flesh-coloured crystals of felspar. From Greenland there 

 is a lamellar, chatoyante Variety which greatly resembles the moon 

 stone. However, the moon stone from Ceylon does not belong to 

 cleavelandite ; it gives easily two cleavages at right angles like felspar. 

 The other cleavages Mr. Levy could not obtain, and what is very 

 remarkable, the direction of the laminae which give the beautiful cha- 

 toyant reflection of light, corresponds to no cleavage of felspar, nor to 

 any of the secondary planes observed in that substance. 



IV. Change of Musket Balls in Shrapnell Shells. 



Mr. Faraday states, that " Mr. Marsh, of Woolwich, gave me some 

 musket balls, which had been taken out of Shrapnell shells. The shells 

 had laid in the bottom of ships, and probably had sea water among 

 them. When the bullets are put in, the aperture is merely closed by 

 a common cork. These bullets were variously acted upon : some were 

 affected only superficially, others more deeply, and some were entirely 



• Mr. Levy proposes soon to publish more minutely the result of his observations; and 

 the exact localities of each specimen will be given. 



