Chemistry and Physics. 



257 



placed in the seventh group, there would be only one column of 

 elements in it, and that KMn0 4 happens to have a similar formula 

 to KC10 4 and to share with it the property of being an oxidizing 

 agent. He calls attention to the fact that the argon group, whose 

 position is on the other side of group VIII, has only one column. 

 He brings forward the similarity of manganese to iron, nickel 

 and cobalt in the formation of sulphates, double sulphates, etc., 

 and to iron and cobalt in the formation of alums, metallocyanides 

 and metallicyanides. He shows the relations of manganese to 

 ruthenium and osmium in the formation of metallicyanides and 

 the salts K„Mn0 4 , KMnO-, KJRuO- , KRuCv and KOsO-. The 



2 4' 4 "2 m 4" 4^ 4 



arrangement advocated is shown in the following table : 



VI 



VII 



VIII 







I 



S 



CI 





Ar 



K 



Cr 





Mn Fe Ni Co 





Cu 



Se 



Br 





Kr 



Rb 



Mo 





Ru Rh Pd — 





Ag- 



Te 



I 





Xe 



Cs 



W 



Os Ir Pt — 



An 



— Chem. News, xevi, 260. h. l. w. 



4. Higher Oxides of Manganese. — Meyer and Rotgers have 

 investigated the well known changes of the oxides MnO„, Mn 2 O s 

 and Mn 3 4 upon ignition in air and oxygen, and have determined 

 the exact temperatures, heretofore unknown, at which the trans- 

 formations take place. It appears that the changes from higher 

 to lower oxides take place at sharply defined temperatures, which 

 vary according to the presence of air or oxygen : 



Air Oxygen 



Mn0 2 

 Mn D 0„ 



Mn 2 3 

 Mn O 



530° 

 940° 



565° 

 1-090° 



Upon cooling Mn 3 4 in contact with oxygen, it is converted into 

 Mn„0 3 , but this change does not take place upon cooling in con- 

 tact with atmospheric air. In the analytical determination of 

 manganese as Mn 3 4 this state of oxidation can be attained with 

 precision if the ignition is continued long enough above 940°, and 

 if the product is cooled in the air. — Zeitsehr. anorgan. Chem., 

 lvii, 104. h. l. w. 



5. White Phosphorus. — It has been observed by Llewellyn 

 that when yellow phosphorus is distilled in a current of ammonia 

 gas a white form of phosphorus is obtained. Upon exposure to 

 the air or warming with water it is gradually converted to the 

 ordinary yellow modification. The author considers this method 

 more convenient than the method of distilling in purified hydro- 

 gen which has been described by Remsen and Reiser. — Chem. 

 News, xevi, 296. h. l. w. 



