448 Intelligence and Miscellaneous Articles. 



in the oxygen tested. Even when the gas was passed for some 

 time through a solution of iodide of potassium and starch no blue 

 colour was perceived. The oxygen used for the experiment re- 

 mained for a week in the iron reservoir into which it was pumped 

 in contact with solid potassic hydrate, by which it was completely 

 freed from C0 2 , from chlorine, and from aqueous vapour. 



From these experiments there can be no doubt that oxygen in 

 the liquid condition, and in layers of about 30 millim., has a de- 

 cidedly bright blue colour. This colour of oxygen agrees very well 

 with its absorption-spectrum. It was surprising that a colourless 

 liquid, such as oxygen w r as supposed to be, had such a pronounced 

 absorption-spectrum, in which the absorptions predominate in 

 orange, in yellow, and in red. But this apparent contradiction 

 has been removed by the above experiments of the author. 



One word in conclusion as to the colour of the sky. There are, 

 as it is known, so many hypotheses which attempt to explain this 

 that the author scarcely dares to propound another. But in his 

 opinion this phenomenon would be most readily explained by as- 

 cribing the blue colour of the sky to this constituent of the atmo- 

 sphere, which has a blue colour, at any rate in the liquid state. — 

 Wiedemann's Annalen, xlii. p. 663. 



ON A PECULIAR CASE IN THE REFRACTION OF ORGANIC 

 COMPOUNDS. BY R. NASINI AND T. COSTA. 



The authors have found a compound formed by the simple union 

 of two others, which, instead of having a molecular refraction 

 double the sum of those of the components, has a far greater one. 

 This compound is the iodide of triethylsulphine, the components 

 being iodide and sulphide of ethyl. The constants are for the 

 compound V, and for the mixture of both, Gr, 5*085 gr. of each 

 dissolved in 100 cubic centim. 



<?? "H, 



MH 2_1 MJJ2 + 2 



4 ' d (S.l~ x )d 



V .... 0-81761 1-36857 0-45079 0-27568 

 Gr .... 0-81076 1-36414 0-44926 0-27509 



The sulphur has therefore a far greater atomic refraction in the 

 compound than in the mixture. It might be supposed that this 

 arises from the fact that the sulphur in the compound is S iv and 

 in the sulphide S"; but this would not agree with the deportment 

 of oxygen compounds in sulphur.— Rend. It. Ace. dei Line. vi. 

 pp. 259-263 (1890); Beibldtter der Physilc, No. 2, 1891. 



