ORGANIC CHEMISTRY 547 



N 



CgHg.C C.CgHg 



\^ 

 NO2 



[vii] 



On keeping in a closed vessel benzaldoxime peroxide was 

 found to decompose, giving benzaldoxime, benzoic acid, and 

 dibenzenylazoxime, but no dibenzenyloxoazoxime nor benzoyl- 

 benzaldoxime. On the other hand, the peroxide, on boiUng 

 with benzene, gave benzaldoxime and dibenzenyloxoazoxime. 



H H H N 



/ \ / /% 



2 CgHsC CCgHs-^" 2 CgHgC + CflHg.C C.CeHs 



\ ^ % %/ 



NO. ON NOH NO2 



This is not in keeping with the results of Beckmann {Ber., 

 1889, 22, 1588) and of Wieldand and Semper {Ber., 1906, 39, 

 2522), who state that dibenzenylazoxime is formed under these 

 conditions. Robin also failed to obtain, by the oxidation of 

 benzaldoxime peroxide with iodine and sodium carbonate, the 

 peroxide of benzil dioxime which Beckmann obtained by the 

 use of nitrogen peroxide as the oxidising agent. 



The action of iodine and alkali on benzsynaldoxime has 

 not been studied, but Robin erroneously supposes that benzal- 

 doxime obtained in the usual manner and distilled in vacuo 

 consists of a mixture of the two isomerides. 



GEOLOGY. By G. W. Tyrrell, A.R.C.Sc, F.G.S., University, Glasgow. 



Petrology. — A valuable summary of the physical chemistry of 

 the crystallisation and magmatic differentiation of igneous 

 rocks is proceeding in the Journal of Geology (29, 1921, 318-50 ; 

 426-43 ; 515-39 ; 627-49) from the pen of the veteran J. H. L. 

 Vogt. The review of mineral relations during crystallisation 

 follows both synthetic and analytic methods ; the former being 

 based on the experimental investigation of silicate melts by the 

 Geophysical Institute, and on Vogt's own work on slags ; the 

 latter based on the study of the texture and structure of the 

 rocks. In this way a mass of observations is being brought 

 together elucidating the order of crystallisation, the individual- 

 isation-fields, the mix-crystal systems, eutectic intergrowths, 

 etc., of the rock-forming minerals. 



Consideration of the Raana norite intrusion in the Ofoten 

 Fiord of Northern Norway has yielded to S. Foslie a remarkable 



