Extracts from Berzelius's Aiuiual Report for 1843. 193 



easily reduced into powder. It is infusible and insoluble in cold water 

 and in warm water, in a cold solution of an alkali, in nitric, hydrochlo- 

 ric and sulphuric acids, and in aqua regia. It is not altered by hydro- 

 gen at the temperature of incandescence ; the vapor of water on the 

 contrary decomposes it at a temperature below red heat — boracic acid, 

 potash, and ammonia, being the products ; all those bodies which retain 

 water at an elevated temperature decompose it, as caustic potash, phos- 

 phoric acid, lime, &c. It is probable that its composition is KBN. By 

 heating the cyanides of the diiferent metals with boracic acid, similar com- 

 pounds are formed. In heating in the same manner 6 parts of silicic acid 

 and 13 parts of cyanide of potassium, a brittle porous mass s obtained, 

 which after washing affords ammonia by fusion with caustic potash. 



Formation of Anunonia. — M. Ruset (Jour, de Phar. et de Chim. II, 

 257) has shown that a mixture of hydrogen gas and nitric oxide, pass- 

 ed through a tube containing heated peroxide of iron, gives rise to the 

 formation of ammonia ; in the space of half an hour, he obtained suf- 

 ficient to saturate an ounce of hydrochloric acid. The oxide of iron 

 exercises simply a catalytic action, and is not reduced so long as there 

 is no excess of hydrogen. 



Calomel. — It is known that the medicinal action of calomel is more 

 energetic in proportion as the powder is finer. M. Soubeiran (Jour, 

 fiir pr. Chem. XXVI, 414) effects this pulverization by means of a bel- 

 lows, which drives a current of air through a large glass tube, contain- 

 ing the calomel heated so as to volatilize it. The cun-ent of air con- 

 denses the vapors, and carries them in the form of a very fine powder 

 into an elongation of the tube connected with a recipient of water. 

 M. Righini (same journal) has shown that when the air is replaced by 

 the vapor of water, a small quantity of corrosive sublimate is formed. 



A Neio Method of Precipitating the SulpJmrets of Metals. — M. 

 Himley (Ann. der Chim. und Pharm. XLII, 347) has made known a 

 new method of precipitating the metallic sulphurets without the use of 

 sulphuretted hydrogen. It consists in mixing the metallic solution with 

 the hyposulphite of soda ; this salt in most cases produces no precipi- 

 tate, but if hydrochloric acid is added, the metallic sulphuret is imme- 

 diately precipitated. All the metals precipitated by sulphuretted hydro- 

 gen, are also precipitated by this method. It is M. Himley's intention 

 to examine into the accuracy of this method by new experiments. 



Determination of the Copper in a Solution of a Binoxide Salt. — M. 

 Level (Ann. de Chim. et de Phys. V, 381) has made an important mod- 

 ification to M. Fuch's method for determining the copper contained in 

 a solution of a binoxide salt, by the quantity of copper required to re- 

 duce it to the state of a protoxide salt. He places the solution of the 

 salt in a vial, adds ammonia until the liquid becomes of a transparent 



Vol. XLvii, No. 1.— April- June, 1844. 25 



