^AKALYSIS, 9 F SODALITE. ggj 



tii^s m a maraellated form, the texture of which is compact, 

 fibrous, and radiated ; the colour pale yellow, in some places 

 passing into white, and marked with brown zones. Hitherto 

 vit had never been found in a state sufficiently perfect to af- 

 .;|ie>rd any indications of form. Lately, however, Mr, de Bour- 

 non was so fortunate as to procure some of it, presenting ^ 

 very delicate needleform crystals, which, by means of u 

 strong magnifier, he was able to ascertain presented flat 

 rectangular prisms, terminated by planes,which, bethought, 

 might form angles of 60° and 120 with the sidesof the prism. 

 With this neither our mineral nor the Swedish can have any 

 connection, farther than some analogy which may exist in 

 their composition. 



Concerning the Swedish mineral I have not been able to 

 obtain much satisfactory information. There is a specimen 

 '40f itin Mr. Allan's cabinet, which he received directly fromi 

 Sweden, sent by a gentleman who had just before been in 

 London, and was well acquainted with the collections of that 

 city,, from which it is inferred, that the specimen in question 

 is the same as that examined by Count Bournon and Dr. 

 Wollaston. 



Werner has lately admitted into his system a new mineral Fettstein 

 species, which he distinguishes by the name of Fettstein. Of 

 this 1 have seen two descriptions; one by Haiiy, in his Ta- 

 bleau Comparatif, published last year; and another by Count 

 Dunin Borkowski, published in the 69th volume of the 

 Journal de Physique, and translated in Nicholson's Journal, 

 {Vol. XXVI, p. 384). The specimen, called Swedish na« 

 trolite, in Mr. Allan's possession, agrees with these descrip- 

 tions in every particular, excepting that its specific gravity 

 is a little higher. Borkowski states the specific gravity of 

 fettstein at 2*563 ; Hauy at 2*6138 ; while 1 found the speci- 

 fic gravity of Mr. Allan's specimen to be 2*779, and, when 

 in small fragments, to be as high as 2*790. This very near apparently tlie 

 agreement in the properties of the Swedish natrolite with the s^^diJ^'j^^y^,. 

 characters of the fettstein leads me to suppose it the sub- lite. ' * 



stance, to which Werner has given that name. This opinion 

 is strengthened, by a fact mentioned by Hayy, that fettstein 

 had been at first considered as a variety of wernerite. For 

 the specimen sent to Mr. Allanj under the nai^fi of compact 



wernente^ 



