460 M. Bechamj) oh PijroxyUne. 



M. "\^illc describes a very convenient apparatus for obtaining 

 a regular supply of hydrogen or sulphuretted hydrogen, which 

 is a modification of Dobereiner's lamp. He points out, that 

 in the fundamental reaction (that of protochloride of iron on a 

 nitrate) a method of nitrogen determinations, similar in execu- 

 tion and principle to that of Dumas, may be formed. The 

 deutoxide of nitrogen is passed over copper-turnings, and the 

 nitrogen estimated as such. But this is much less general and 

 less certain than the others. 



In the same journal M. Bechamp has a paper on Pyroxy- 

 liue. He considers pyroxyline or gun-cotton as a compound of 

 cellulose, in which 5 equivs. HO are replaced by 5 equivs. NO'^ : 

 Q24 JJ17 017 5N0^ and names it pentanitrocelMose. He had 

 found before, that the action of ammoniacal gas gave rise to 

 a new compound, fernitropyroxi/line, C^-H'''0'''3N0^. By the 

 action of caustic potash on a solution in sether and alcohol of 

 pyroxyline, he obtained an intermediate ]n-oduct,tet7-anit7-opi/roxi/- 

 line, C°°H'' O^^'iNO-^. These three uitro-compounds of cellu- 

 lose differ not only in their definite composition, and in the cir- 

 cumstances of their formation, but also in many of their proper- 

 ties, as the action of solvents, that of reagents, and that of heat. 



The action of caustic potash on pyroxyline in the presence of 

 water is difterent. The final product is in this case sugar. There 

 are intermediate stages in the reaction, but they are not very 

 distinctly marked. The quantity of sugar could not be ascer- 

 tained, for a great part of it is decomposed into apoglucic and 

 other acids. 



Sulphurous acid is without action on pyroxyline. Sulphuretted 

 hydrogen acts, but the products formed are not definite. When 

 pyroxyline is introduced into a strong solution of protochloride 

 of iron, the iron is peroxidized, all the nitrogen is evolved as 

 deutoxide of nitrogen, and the cotton is reproduced, retaining 

 its texture, and all its physical properties. The reaction may be 

 thus written : — 



C24Hi7O'"5NO^ + 30FeO-!-3HO = 15Fe2O3-f-5NO2 

 + C2-* W 0-0. 

 From the reproduced cotton, gun-cotton was prepared. By 

 treatment with sulphuric acid it was converted successively into 

 dextrine and sugar. 



By the action of protochloride of iron, the primitive matter 

 niav be produced from the nitro-compounds formed by the action 

 of nitric acid on starch, gum, mannite, and quercite, as well as 

 from the nitric fethers in general. 



There arc two distinct series of nitro-compounds ; that of which 

 nitrobenzine and analogous bodies are the types, and that of 



