500 Chronicles of Science. [July* 



poses, and the only objection to its use is the evolution of some 

 sulphuretted hydrogen, which would seem to be unavoidable. In the 

 course of his experiments, the author arrived at the following con- 

 clusions : — 1. That finely-divided sulphur in contact with the electro- 

 negative metal of a pile formed of zinc, copper, and solution of 

 common salt notably increased the electro-motive force, constancy, 

 and permanency of the battery, and he hopes to obtain by the use of 

 sulphur a voltaic combination possessing many advantages over the 

 batteries at present employed. 2. Sulphur, although insoluble and 

 an insulator, enters into combination with the sodium set free by the 

 current. It remains for the author to explain the action of the small 

 quantity of sulphide of copper which is formed, and which appears 

 to be essential. For this end he has undertaken further experi- 

 ments. 



In a note presented to the Academy of Sciences in May last, 

 M. de la Eive mentioned that a piece of crown or heavy flint glass 

 through which a discharge from a large Ehumkorff is passed, under- 

 goes a permanent molecular modification in its whole extent, losing 

 almost entirely its rotatory magnetic power, and acquiring the pro- 

 perties of a crystalline body, or glass suddenly cooled. 



A very interesting paper by M. Morren is given in the March 

 Number of the ' Annales de Chimie et de Physique,' " On the Phos- 

 phoresence of Rarefied Gas during the Passage of the Electric Spark." 

 The author endeavoured to discover the cause of the milky-white fog 

 seen in some of Geissler's tribes. It has been attributed by many to 

 the presence of oxygen ; but this idea M. Morren shows is incorrect. 

 He finds, in fact, that pure and dry oxygen, however much rarefied, is 

 never phosphorescent ; and, indeed, that no gas, simple or compound, 

 is phosphorescent by itself. A mixture of oxygen and nitrogen, with 

 37 of nitrogen to 100 of oxygen, is feebly phosphorescent ; but the 

 phenomenon becomes much more visible when a little vapour of nitric 

 acid is added to the mixture. But it becomes magnificent and lasting 

 when to the preceding mixture a drop of Nordhausen acid or a little 

 vapour of sulphuric acid is added. The same result may be obtained 

 by passing the spark through a rarefied mixture of the following 

 gases : — 



Oxygen . . . . . . 500 



Nitrogen 200 



Sulphurous acid ..... 300 



Or, 

 Very dry atmospheric air . . . .100 



Oxygen .... 30 



And a little Nordhausen or anhydrous sulphuric acid. Other acids 

 besides sulphuric will produce similar results — nitric and carbonic, 

 for example ; and the author shows the probability of being able to 

 combine these gases with N0 3 . He states that it is possible to form 

 directly the compound N0 3 2S0 3 by the spark in convenient ap- 

 paratus. 



