238 Intelligence and Miscellaneous Articles. 



It appears from this analysis that heaumontite should he classed 

 with the zeolites, and that it contains more silica than any one 

 hitherto descrihed ; it is undoubtedly to this circumstance that its re- 

 sistance to acids is owing, and also its hardness, which is nearly equal 

 to that of phosphate of lime. — Ann. de Ch. et de Phys., Decernbre 

 1843. 



DESCRIPTION AND ANALYSIS OF SISMONDINE (a NEW MINERAL). 

 BY M. A. DELESSE. 

 This substance is found at St. Marcel, and the name was given to 

 it in honour of M. Sismonda, Professor in the University of Turin, 

 and author of the geological map of Piedmont. 



Its characters are, that it is of a deep green colour, possessing 

 much splendour, it cleaves readily and reflects the light brilliantly ; 

 it is brittle and easily powdered, the colour of the powder is a bright 

 grayish green. It does not affect the magnet, either before or after 

 calcination. It scratches glass, but is scratched by steel ; its density 

 is 3*565 ; the crystalline form of this mineral could not be deter- 

 mined. 



This mineral occurs imbedded in a kind of slaty chlorite, and is 

 accompanied with red dodecahedral garnets and titaniferous iron, 

 the fracture of which resembles plumbago, and the powder is per- 

 fectly black. 



When heated in a glass tube sismondine yields water, but it re- 

 quires to be strongly heated to produce this effect ; the water is not 

 acid, nor does it act on the tube. Before the blowpipe it does not 

 fuse, but becomes of a varying tombac brown. It dissolves with the 

 salt of phosphorus, but with difficulty ; when it is powdered the so- 

 lution takes place totally and readily ; the pearl, which is coloured 

 when hot, becomes colourless on cooling. 



With borax the reaction of iron is evident ; with soda there is 

 lively effervescence ; small white skeletons of silica float without 

 dissolving in the interior of the pearl, which when cold is not trans- 

 parent ; with nitrate of cobalt a dirty gray colour is produced ; when 

 very finely levigated sismondine is completely acted upon by sulphu- 

 ric, hydrochloric, and even by nitric acid, a white granular residue of 

 silica is left, which is not dissolved by the acids ; after calcination the 

 action of the acids is not so easy. 

 By analysis it yielded — 



Silica 24-1 



Alumina 43*2 



Protoxide of iron. . 23*8 



Water 7"6 



Oxide of titanium trace 

 98-7 

 Ann. de Ch. et de Phys., Decernbre 1843. 



A METEOROLOGICAL PHENOMENON. 



About the middle of March 1843, an anthelion was observed on a 

 cloud in the vicinity of Cork by Mr. H. Hennessy. 



