Physics and Chemistry. 105 
been fully established by the late researches of Laurent, Hoffman and 
Muspratt, which have shown that the elements of nitrous acid may, like 
chlorine and bromine, replace the hydrogen in many organic compounds, 
Inconformity to this view, the formula of veylondlas will beC,, H, 2NO, 
10> in which the elements of two equivalents of nitrous acid are sub- 
stituted for two of hydrogen in cellulose. 
@ arrangement of its elements is such as to produce in its com- 
bustion an immense volume of permanent gases and elastic vapor, 
on whose instantaneous oeaihabaln thes rn of the gun-cotton depends. 
In the production of the gun-cotton by the process described, two equiv- 
alents of hydrogen from the vegetable fibre react with two of nitric acid 
to form two of water and two of nitrous acid; the latter enter into 
the constitution of gun cotton, while the te formed remains in bir 
acid mixture, and so far dilutes it as soon to render it unfit for 
Hence the necessity of changing the noe rae In dilute nitric att 
the xyloidine dissolves, forming oxalic acid. When, in its preparation, 
the gun-cotton is seen to become gelatioous and Sentnaneeee itis a 
the Bons unds 0 ps he and Nitrogen; by C. Grr- 
HAR RDT, iaiecsoins Rendus, 1846.)—Two compounds of phosphorus and 
nitrogen have been supposed to exist, the one PNg, the other a hy- 
drate PN,4+HO. This composition being vara to the views of 
Laurent and Gerhardt, the latter undertook the reéxamination of the 
ct. He found that the so-called phosphuret and its hydrate were 
noe of three substances named s. him phosphamide, biphosphamide 
osp: 
P hosphamide, —When ammoniacal gas is made to pass over chlorid 
of phosphorus contained in a long tube, the chlorid becomes heated and 
gives off much sal-ammoniac. ‘The produet (a white powder) treated 
with water, dissolves in part only; the insoluble residue is impure 
phosphamide, which is purified by boiling for several hours in a dilute 
solution of potash, then in weak nitric acid and lastly in water; dried 
at 212° its formula is PH, 
This substance heated i in a metallic bath loses not a trace of water ; 
above 390° it gives off pure ammonia and isconverted into biphospha mide. 
The formation of phosphamide is pr as by the following form- 
ula: PH 30,+2(NH, )—6(HO)=PH,N,0,. 
Bipho. osphamide is formed: when dry ‘phosphamide i is heated, all the 
hydrogen goes off as ammonia, and there is le NO,. Mois! tened 
with water and heated, this substance gives phosphoric acid pies ammo- 
nia. Melted with caustic potash, this as well as the former orms phos- 
phate and gives off ammonia. This is remarkable as ab: the first 
amide not containing hydrogen, and on this account Gerhardt says it 
“ must sare puzzle the advocates of radicals and the dualistic theory.” 
Phospham.—The product of the action of ammonia upon the per- 
trogen, PNas ‘5 it is Tower a na and minute precautions are 
wenden as “produce , PHN,. The presence of 
_—— was aiden: by Dpkiebinasd and PWatler to be accidental. There 
is, however, 1:5 per cent. of hydrogen in this wan Fused pees 
Srconp Reiss Vol. ILI, No. 7.—Jan., 1847. 
