436 Miscellaneous Intelligence, 



will become a solid, vitreous, transparent mass, fixed in the air, and 

 resembling ordinary glass, except that it is less hard. 



This substance has an alkaline action ; it dissolves with difficulty 

 in cold water, more easily in boiling water. It is somewhat hygro- 

 metric, and in many weeks will attract moisture from the air, which 

 penetrating it does not however destroy its aggregation, but causes 

 the surface to become covered with scales or powder. Alcohol 

 precipitates the aqueous solution ; acids decompose the substance ; 

 many salts form insoluble precipitates with it. This new silicate 

 of potash is composed of sixty-two parts silica, twenty-six of potash, 

 and twelve of water. It may be employed as a coating for wood 

 and other objects to preserve them from fire, and also as a lute in 

 the laboratory. — Kastners Archives, v. 385. 



15. Fulminating Powder. — According to M. Landgerbe, a mixture 

 of two parts nitre, two parts neutral carbonate of potash, one part 

 of sulphur, and six parts of common salt, all finely pulverised, 

 makes a very powerful fulminating powder. M. Landgerbe adopts 

 the extraordinary error of supposing that these preparations act with 

 more force downwards than in any other direction. — Bull, Univ, 

 A. X. 151. 



16. Crystallization of Sulphate of Potash. — If it be desired to 

 procure very large and regular crystals of neutral sulphate of 

 potash, it is only necessary to add a little sub-carbonate of potash 

 to the solution of this salt, and then leave it to evaporate spon- 

 taneously in a vessel rather greater in width than depth ; only one, 

 two, or at most three crystals will be obtained, but they will be of 

 extreme size and beauty. — ^Van Mons, Kastner*s Archives, v. 462. 



17. On Double Saline Compounds obtained by Heat and Fusion, 

 by M. Berthier. — M. Berthier has described an extensive series of 

 experiments on the production of double salts by igneous fusion : 

 the results are highly interesting, and we shall give most of them, 

 but in as condensed a form as possible. 



One atom of native carbonate of baryta 24.64, with one atom of 

 anhydrous carbonate of soda 13.32, fused at a red heat, becoming 

 as clear and transparent as water, and by cooling, forming a com- 

 pact mass, penetrated by numerous crystalline plates. 



Single atoms or proportionals of the carbonates of strontia and 

 soda, readily fused, producing, when cold, a stony compound of 

 unequal fracture, and but slightly crystalline. 



One proportional of carbonate of soda, with one of carbonate of 

 lime, and with two ; these mixtures readily fused, and if cooled 

 suddenly, were compact, white, and translucent like enamel, and 

 with a very crystalline fracture. They may be readily re-fused ; but 

 if the temperature be raised too high, carbonic acid is evolved, and 

 the fused mass becomes solid, 



