1896.] Mr Fenton, On Dioxymaleic acid and its derivatives. 143 



By oxidation with bromine the original acid is converted 

 quantitatively into dioxy tartaric acid. It is easy to prepare 

 considerable quantities of free dioxytartaric acid in this way, and 

 the author suggests the use of this acid as a delicate reagent for 

 sodium. 



The constitution of the original acid has been established by 

 determination of its molecular weight (in various ways), its 

 basicity, the behaviour of acetyl chloride, benzoyl chloride, aniline 

 and other reagents, and by its relation to succinic tartaric and 

 dioxytartaric acids. It is shewn to be a tetrahydroxylic, dibasic, 

 unsaturated acid belonging to the maleic series. Its formula is 

 therefore OH . C . COOH 



II 

 OH . C . COOH. 



By action of hydrogen bromide, an isomeric modification has 

 been obtained having a distinct crystalline form and yielding a 

 more stable aniline salt. It is suggested that this may be the 

 corresponding dioxy fu marie acid. 



(3) On the atomic weight of Oxygen. By A. Scott, M.A., 

 Trinity College. 



Mr Scott gave a short account of the present state of our 

 knowledge as to the atomic weight of oxygen, and said that it 

 might be regarded as conclusively proved that if H = 1, O — 15-87 

 to 15 "88. Morley determined the densities of hydrogen, and 

 oxygen, the ratios by volume in which the gases covnbine (by a 

 somewhat indirect method) and finally combined known weights 

 of hydrogen and weighed the water produced. Thomsen made 

 similar determinations but with far less pretension to the highest 

 accuracy attainable. The results were 



Morley. Thomsen. 



Weight of a litre of oxygen) 



at 0°C. and 760 mm. at 1-42900 1-42906 



sea level, lat. 45°. ) 



ditto for hydrogen -089873 -089947 



Ratio of densities 15-9002 15-8878 



Ratio of combining volumes 1 : 2-00269 1 : 2-00237 

 Atomic weight of oxygen... 15-879 15-869 o 



The ratios by volume in which the gases combine agree well w 

 that published by the author directly three years ago, viz. 



1 : 200245 at about 15°, 

 and 1 : 2-00285 at 0° C. ' v °" 



11—2 



