620 . REPORT— 1894. 



of pheaolphthalein solution is added, ■wliich is prepared by dissolving '2 grm. of 

 phenolphtlialein in 100 c.c. of equal volumes of alcohol and water. 



Time Condition of the Air 



Under 3 minutes ...'.. Bad 



Above 3 and under 5 „ Fair 



Above 5 „ Good 



11. On the Diffusion of very Dilute Solutions of Chlorine and Iodine. 



By A. P. Laurie. 



TUESDAY, AUGUST 14, 

 The following Papers and Report were read : — 



1. Investigations on Tatitomerism. By Professor W. J. Bruhl. 



2. On Ortho-dinitroso Derivatives of the Aroniatic Series. 

 By Professor E. Noelting, Mulhouse, Alsace. 



In a paper jointly published about two years ago by Messrs. Grandmougin, 

 Michel, and myself, the fact has been mentioned that ortho-nitrodiazobenzeneimide, 

 upon being heated with water or distilled with steam, evolved nitrogen, and that 

 finally a new body fusing at 70°-71° was produced. 



A recent investigation of that body, undertaken in collaboration with Dr. 

 Karl Kohn, has proved its composition to agree with the formula CgH^N.^Oo, and 

 the determination of its molecular weight gave numbers corresponding to this 

 simplest formula and not to that of a polymere. 



The action of reducing agents resulted in the formation of ortho-phenylene- 

 diamine. 



These facts render it probable that the new body is ortho-dinitroso-benzene, a 

 para-isomere of which had already been made known by Nietzki. It was produced 

 by the oxidation of para-quinone-dioxime. The analogous oxidation of ortho- 

 naphto-quinone-dioxime into the corresponding ortho-dinitroso-compound has, 

 eome time before Nietzki, been carried out by Ilinski. This oxidation is rendered 

 evident by the following formula : — 



CioHu>^^^^j^Q jj + O = H„0 + C,„Hu ^Q 



Now the investigation of Mr. Kohn and myself on the products of decomposi- 

 tion of the two ortho-nitronaphtalenediazoimides 



NO, jj 



I I 



by heat, has proved the identity of the products thus obtained with the ortho- 

 •dinitroso compounds described by Ilinski. 



