156 Intelligence and Miscellaneous Articles. 



" The authors who have since mentioned this substance have 

 merely repeated what has been stated by Cleaveland. Mr. Brooke, in 

 his article on Mineralogy in the Encyclopsedia Metropolitana, classes, 

 without assigning any reason, haydenite with heulandite. I will 

 add what appears to me singular, which is, that in a work recently 

 published in the United States, entitled a System of Mineralogy, 

 by James Dana, and printed at Newhaven in 1837, no mention is 

 made of this species, though in other respects the work appears to 

 be pretty complete. 



" The cause of our ignorance respecting the nature of haydenite, 

 may be explained by the small number of specimens which have 

 been brought to Europe. M. Levy then goes on to state that he 

 had seen only three specimens of ha^^denite, and the account which 

 he gives of it is as follows : — Haydenite is regularly crystallized ; the 

 crystals have the form of a small oblique prism with rhombic bases, 

 in which the incidence of the lateral faces is 98° 22', and the inci- 

 dence of the base, on each of the lateral faces, is 96° 5'. The cry- 

 stals are frequently macled. The axis of revolution, around which 

 one of the two crystals forming the made is supposed to have turned 

 180°, is perpendicular to the base of the primitive form, and the face by 

 M^hich the two crystals are united is parallel to the same base. The 

 crystals are thickly grouped together, and a small portion only of 

 each is isolated. I have observed no modification either upon the 

 edges or angles, so that the relation between the sides of the base 

 and the lateral edges remains undetermined. The crystals cleave with 

 the same facUity on every face of the primary form. The cleavage 

 faces sometimes present an uneven surface on account of small dark 

 spots, as if the substance had suffered incipient decomposition. The 

 crystals are usually covered by a thin layer of hydrate of iron, which 

 is readily detached by the knife, and the faces of the crystals thus 

 exposed are sufficiently brilliant to be measured by the reflective 

 goniometer. The colour of haydenite is brownish yellow or green- 

 ish yellow ; the crystals are translucent and sometimes transparent, 

 they are easily scratched by the knife, readUy friable ; the hardness 

 is nearly the same as that of fluor sjjar. The quantity detached was 

 too small to admit of its specific gravity being taken." — L'Institut. 



BEAUMONTITE, A NEW MINERAL. 



This is a new mineral discovered by M. Levy. It accompanies 

 haydenite, and is named in honour of M. Elie de Beaumont. It oc- 

 curs in small brilliant crystals of a pearly lustre. Their form is that 

 of a prism with square bases, terminated by obtuse pyramids. The 

 summits of all the crystals are closely grouped. The incidences of 

 the faces of the terminal pyramids, measured with Wollaston's 

 goniometer, are 132° 20' of the two faces, the intersection of which 

 is parallel to one of the edges of the base of the primary form, and 

 147° 18' of the two faces above, whose intersection is inclined to this 

 base. One of these angles is a necessary consequence of the other. 

 By calculating from the first, the second is 147° 28', instead of 147° 

 18', as determined by experiment. The primary form of the beau- 



