.18i25/| Scientific 'Notices^^Mineratogy, 383 



Now, 



4 atoms phosphoric acid ,,,,,,., = 14 



,,1^/1 ^m carbonic acid ._ti^.^:^*>^ „ = 2*75 »<{! 



^-BqiB9fllS#^W^''W^^®^>*^^te«<*^^^^ 61-87^ :-• 



H^ttk^l in^'^^^^pos^^ ^^ (Consider tlie's^Lft a!s' a compound of 



■ -^oqz9 yd Iwi -s^- r, :\ r ■■ • ./• ; ! 



fin m "^^ atoms phosphate of soda 30 



1 atom carbonate of soda 6*75 ' 



^'iifl lo d5&%toms water />* .t^^-* 61*875 



'- i^jiinBup JntJi-A. . itfvi un; .^~ 



^4d8fiw nariw ^rimiiw ,tl^'i 'vf 98-625 



If this T)e really a compound of phosphate and carbonate of 

 soda, the union is very slight ; for I found that by repeated 

 solutions and crystallizations, I could separate from it phosphate 

 of soda in the usual rhomboidal form. What leads to the notion 

 that it is a compound salt, is the form of the crystals — asix-sided 

 prism apparently regular, which could not be derived from the 



f^rimary form of phosphate of soda. Nor is the water of crystal- 

 ization what it would be if the salt were a mere mixture of 4 

 atoms of phosphate of soda, and 1 atom of carbonate of soda ; 

 for phosphate of soda containing 12 atoms, and carbonate of 

 soda 10 atoms, the v/ater of crystallization should have amounted 

 to 58 atoms, instead of db — the quantity found, unless there was 

 an error in the analysis. I do not well see, however, how any 

 supposed error could serve to diminish the apparent quantity of 

 water in the salt ; but it is possible that the salt may have sust 

 tained a loss of water before I began to examine it. — (Dr. Thojpfi- 

 son's Attempt to establish the First Principles of Chemistry ,)|p 



MlKERALOGY. -^^ii^^-4^^ 



^ ..j ,^,^5 , o. Beryl m LornwalL 



Ki'iO'ig£ .a i 



We have been favoured by Mr. A. R. Barclay, with a notice 

 of his discovery of the existence of the Beryl, in Cornwall ; he 

 states that the crystals are nearly colourless, though some have a 

 very faint greenish hue ; they are six-sided, the summits of a 

 few have the edges of the plane taken off, but most of them 

 are flat; they are very small, and some thickly grouped; with 

 the blowpipe they become of an opaque white. They are 

 accompanied with apatite and mica, crystallized upon a dark 

 grey quartzy wall of a vein which so commonly traverses the 

 granite and schist of St. Michael's Mount, and in which most 

 of the minerals to be met with at that interesting spot occur. 

 They were not discovered in situ, but found in one large mass 

 or slab, lying detached close to the little cliff of debris, on the 

 south side of the Mount, at that part only which would be 

 washed by very high or stormy tides. 



