192 Extracts from Berzelius's Annual Report for 1843. 



method with arsenious acid. One hundred volumes of water dissolved 

 the following volumes of chlorine gas : 



175 to 180 vol. at the temp, of 0° cent. 



270 to 275 9 



(t 



a 



a 



u 



ct 



270 to 275 " " 10 



250 to 260 " " 12 " 



250 to 260 " u 14 " 



245 to 250 " " 



200 to 210 " " 30 



155 to 160 " " 40 



115 to 120 " " 50 " 



60 to 65 " " 70 " 



Hydrobromic and Hydriodic Acid.—M. Millon (Jour, de Pharm. ct 

 de Chim. I, 299) has' proposed a modification of the ordinary method. 

 He employs the bromide or the iodide of potassium in the place of the 

 pulverized glass, and thus obtains a much larger quantity of the hy- 

 dracids, because the salt employed is decomposed by the phosphoric 

 acid which it converts into phosphate of potash. The proportions that 

 react are, 2 ats. of the salt of potash, 5 ats. of the bromine or iodine, 

 1 at. of phosphorus, and 7 ats. water. To obtain the hydrobromic acid, 

 M. Millon employs 15 grammes of the bromide potassium and a little 

 water, to which he adds 25 grammes of bromine, and 2 grammes * 

 phosphorus cut up in small pieces. The hydrobromic acid soon begins 

 to be so rapidly disengaged, that it becomes at times necessary to plunge 

 the vessel in cold water to check the action. "When „_ 

 of gas becomes slow, it is aided by a little heat. In the preparation o 

 the hydriodic acid, it is necessary to heat from the beginning, and 

 escape of gas is very uniform. 



Cyanogen. — M. Wohler has shown that when nitrogen gas con- 

 taining moisture is passed over a mixture of potash and charcoal c\ 

 nide of potassium is formed, but if the gas be dry no cyanoge 



of 



formed. 



analogous to Cyanogen ft 



o! 



Boron and Silicon with Nitrogen.— M. Balmain (Phil. Mag. XXI, 2/ J 

 has described some very interesting experiments which seem to p 

 that boron and silicon form with nitrogen combinations endowe 

 the halogen properties of cyanogen. When a mixture of ' p ar 

 anhydrous boracic acid and 20 parts of cyanide of potassium * 

 posed in a well covered crucible to a white heat, there remains 

 cooling a porous mass. The proportions of this mixture are calcU „ 

 in such manner as that the carbon of the cyanide of potassium su £ 

 exactly to reduce the boracic acid in being converted into car ^ 

 oxide. The substance as taken from the crucible is white and po 



