458 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the action of Permanganate upon Hydrogen Peroxide. 

 — Several views have been advanced in explanation of this well 

 known decomposition, in which the permanganate is decolorized 

 and oxygen is evolved. Berthelot believes that a trioxide of 

 hydrogen is produced which undergoes spontaneous decomposition 

 into water and oxygen. This idea is based upon the fact that he 

 produced the decomposition at —12° without effervescence taking 

 place. Schonbein's theory is that the two substances simultane- 

 ously give up atomic oxygen which condenses to the molecular 

 condition. It is the view of Weltzien and Traube that per- 

 manganic acid oxidizes the hydrogen of hydrogen peroxide to 

 water, thus liberating oxygen. According to the last explanation 

 all of the evolved oxygen originates in the hydrogen peroxide. 



Baeyer and Villiger have recently shown that the phenome- 

 non observed by Berthelot was due to the supersaturation of the 

 liquid by oxygen, and that if the liquid be gently agitated the 

 evolution of gas takes place regularly. They observe that the 

 hypothetical formation of hydrogen trioxide is an assumption 

 which is supported by the formation of potassium polysulphide 

 when sulphur and potassium sulphide are brought together, and 

 also by the formation of potassium tri- or tetra-oxide, as observed 

 by Schone, when a solution of hydrogen peroxide is evaporated 

 with potash ; but the assumption now lacks foundation in fact. 

 According to Schonbein's theory both substances act as oxidizing 

 agents. The authors believe, however, that hydrogen peroxide 

 is hardly to be considered as such an agent, since in the pure 

 condition it decomposes dilute hydriodic acid only very slowly. 

 Moreover, if the theory is true, the more strongly oxidizing deriva- 

 tives of hydrogen peroxide should oxidize permanganate still 

 more easily and evolve oxygen, while in fact exactly the opposite 

 is the case, for example, with " Caro's acid " which does not 

 attack permanganate. This view, therefore, is not supported by 

 facts. The authors strongly favor the view of Weltzien and 

 Traube that it is the hydrogen of the hydrogen peroxide that is 

 oxidized to watei\ Hydrogen peroxide thus shows a behavior 

 analogous to that of hydrogen sulphide, with which it shows a 

 striking similarity in many other ways. They urge the adoption 

 of this theory, agreeing as it does with the present state of our 

 knowledge, by the authors of elementary text-books. — Berichte, 

 xxxiii, 2488. h. l. w. 



2. An Instance of Trivalent Carbon : Triphenylmethyl. — In a 

 preliminary paper Gomberg describes a body produced by the 

 action of zinc upon triphenylchlormethane, (C 6 H 5 ) 3 C CI, which is 

 an unsaturated compound apparently containing but one carbon 

 atom and corresponding to the formula (C 6 HJ 3 C. The substance 



