526 M. Duprey on Oxygenated Water, 



C 4 HT10 8 j the acid tartrate, C 8 H 5 T10 12 ; the paratartrate, 

 the malate, the citrate, the formate, the acetate, valerianate, 

 benzoate, urate, picrate, the cyanide, and the sulphocyanide, 

 Cy Tl S 2 , and the cyanate, C 2 N Tl O 2 . 



M. de la Provostaye has given a crystallographical description 

 of these salts. 



To prepare perfectly pure oxygenated water, Duprey recom- 

 mends* that a very rapid current of carbonic acid be passed 

 through distilled water, and from time to time small quantities 

 of finely-powdered peroxide of barium projected into the liquid ; 

 when the quantity of carbonate of baryta formed is so great as 

 to hinder the passage of the gas, the clear liquid is decanted and 

 the operation repeated. In this way a solution is obtained which 

 is strongly charged with pure neutral binoxide of hydrogen, 

 which may be concentrated under the air-pump receiver. It is 

 necessary that the current of gas be very rapid, so that it be in 

 excess as regards the binoxide. 



Chevreulf has made some experiments on the effects of this 

 solution on vegetable colours, and finds that it acts upon them 

 like chlorine, only more slowly. 



At a very high temperature, Caron's alloy of zinc and cal- 

 cium % can, according to W6hler§, be made to form with char- 

 coal a carbide of calcium, of which a fuller description will be 

 given. This compound has the remarkable property that, when 

 it is treated with water, it decomposes into hydrate of lime and 

 acetylene gas. The gas was not analysed, but there could be no 

 doubt of its identity ; for it burns with a luminous fuliginous 

 flame, is decomposed by chlorine even in diffused light with 

 separation of carbon, and precipitates an explosive compound 

 from an ammoniacal solution of oxide of silver. 



M. BechampH has published an investigation on xyloidine, 

 the body obtained by the action of nitric acid on starch, and on 

 some nitric derivatives of starch. He has shown that xyloidine 

 is a mononitric derivative of starch. It is best obtained by mix- 

 ing one part of dry starch in a mortar with 5 to 8 parts of fuming 

 nitric acid, until the whole is reduced to a perfectly transparent 

 semifluid mass, to which 20 to 30 parts of cold distilled water are 

 then added. A granular insoluble powder is thereby separated, 

 which is washed, dried, dissolved in a mixture of equal parts of 

 cry stalliz able acetic acid, and of terhydrated acetic acid, and the 



* Comptes Rendus, November 10, 1862. f Ibid. 



% Phil. Mag. S. 4. vol. xx. p. 376. 



§ Liebig's Annalen, November 1862. 



|| Annates de Chimie et de Physique, March 1862. 



