a]2 REPORT—1904. 
term ‘halochromy’ as descriptive of this phenomenon, and it does not seem im~ 
possible that the colour of phthalein salts is due to a kind of halochromy. 
The author is continuing his work in another direction, and hopes to obtain 
further evidence bearing on this question. 
4, Studies in the Dynamic Isomerism of a- and (3-Crotonic Acids. 
Y 
By R. 8S. Morrewt and E. K. Hanson. 
5. Mesoxalic Semialdehyde. By Henry J. Horstman Fenton, 7.2.8. 
Mesoxalic semialdehyde (COOIL—CO—CHO), it has been previously shown,! 
can be obtained by the oxidation of dihydroxymaleic acid with ferric salts at 
about 40°. This method is not altogether satisfactory, owing to the difficulty of 
removing the iron salts, and it is now found that the oxidation may advanta- 
geously be effected by means of mercuric chloride. In this case the mercury 
separates almost quantitatively as calomel, and any traces remaining may be 
removed by hydrogen sulphide. The properties of this semialdehyde are being 
further studied, and appear to be of considerable interest. It is evident that the 
aldehyde hydrate COOH—-CO—CH(OH), may be regarded as a tautomeric form 
of the missing trihydroxyacrylic acid, COOH—C(OH=C(OH),, and the latter 
should, by condensation with two molecules of urea, yield uric acid. 
If a solution of mesoxalic semialdehyde is mixed with urea and heated, 
together with dilute hydrochloric acid, a large yield of a very sparingly soluble 
crystalline substance is obtained which, by its properties and composition, proves 
to be glycouril, C,H,N,O,. This compound was originally obtained by reduction 
of allantoin, and afterwards from glyoxal and urea, 
It is evident, therefore, that a molecule of carbon dioxide splits off in tbe 
reaction above described ; later experiments appear to indicate, however, that hy 
modifying the conditions this loss may be prevented, in which case it is hoped 
that uric acid itself may be obtained. 
Although the properties of glycouril have been carefully studied by various 
authors, the following very striking colour-reaction appears to have been over- 
looked: the substance is evaporated to dryness with strong nitric acid on a 
water bath and the white residue dissolved in caustic soda; a faint blue violet 
colour here results, and now, on addition of sodium hypochlorite, a very brilliant 
purple colour is obtained, 
6. Note on the Influence of Radium Radiations on Atmospheric Oxidation 
in presence of Iron. By Henry J. Horstman Fenton, 7.2.5, 
It has been pointed out by the author in previous communications? that the 
oxidation of certain hydroxy-compounds, such as tartaric acid or glycol in 
presence of iron, may be brought about by atmospheric oxygen in presence of 
sunlight, and that the products are the same as those obtained when hydrogen 
dioxide is employed as oxidizing agent. It is now found that the influence of 
yadiations from radium bromide may, in certain cases, produce effects similar in 
this respect to those obtained by exposure to sunlight. A solution of tartaric 
acid, for example, containing a small quantity of ferrous tartrate, was divided into 
two parts and kept in the dark in presence of air, one of the tubes being placed 
directly over a specimen of radium bromide. On testing the solutions after a day 
or two with phenylhydrazine acetate a very striking difference was observed in 
the results, the exposed solution giving a comparatively copious precipitate of 
Nastvogel’s osazone. 
1 Fenton and Ryffel, Trans. Chem. Soc., 1902. 
2 British Association Report, 1895 and 1898. 
