Miitera/ogi/, &;c. 171 



§ 2. Mineralogy, Geology, Sj-c. 



1 . Native Carbonate of Magnesia. — This substance has lately 

 been discovered at Hoboken, in Staten Island, at the same place 

 where the hydrate of magnesia, was found by Dr. Bruce. It 

 occurs in horizontal veins about two inches thick, in a serpentine 

 rock. At first it was soft, white, and slightly adhesive ; but when 

 dry it easily rubbed to powder. It is perfectly soluble with ef- 

 fervescence in sulphuric acid, yielding, on evaporation, crystals 

 of sulphate of magnesia. More lately, the same gentleman has 

 discovered in the same place, veins of carbonate of magnesia, in 

 fine acicular crystals. They were grouped in minute fibres, radi- 

 ating Trom the sides ; sometimes the crystals were suspended, 

 and assumed the stalactitic form. 



2. Analysis of the Euclase, by M. Berzelius. — I owe to the ge- 

 nerosity of M. de Souza, formerly ambassador from Portugal to 

 France, the specimen of this rare stone, which I have employed 

 for an analytical experiment. The stone reduced to powder was 

 heated with carbonate of soda, in a platinum crucible, and then 

 being acted on by dilute muriatic acid, left a light white powder, 

 which was separated ; the fluid was evaporated to dryness, and 

 treated as is usual in analyses of the emerald. The powder, in- 

 soluble in muriatic acid, resembled oxide of tantalium. It was 

 heated with super-sulphate of soda ; a portion dissolved, but as 

 the whole of the saline mass was soluble in water, the powder 

 could not be oxide of tantalium. A current of sulphuretted 

 hydrogen gas was passed into the solution, and threw down a 

 yellowish precipitate, which, after being dried and weighed, was 

 entirely reduced before the blow-pipe, and gave a globule of tin. 

 The fluid, precipitated by the gas, gave, with ammonia, a preci- 

 l>itate solul)le in carbonate of ammonia. It was ghicinc. I have 

 thought it right to notice this property which glucine has of 

 giving, with oxide of tin, a combination which resists for a lon<>- 

 time the action of acids, because, in the analysis of the "-ado- 

 linitc of Kovaifiirl, the same thing happened to uie with a com- 

 bination between gkitinc and I he oxides of manganese and ce- 



