ON THE CIILORONITRIDES OF PHOSPHORUS AND THE METAPHOSPHIMIC ACIDS. 
Bv H. N. Stokes 
i. ON TRI- AND TETRAPHOSPHONITRILIC CHLORIDES.' 
"Chlorophosphuret of nitrogen 7 ' (Ohlorphosphorstickstoif) was dis- 
covered in 1832 by Liebig, 2 while attempting to prepare amides of 
phosphoric acid by acting on phosphorus pentachloride with gaseous 
ammonia and with ammonium chloride. Analysis 3 led to the formula 
P3N2CI5, and he observed that the compound could be distilled with 
steam or boiled with acids or alkalies without appreciable decomposi- 
tion — properties uuique in a phosphorus-chlorine compound. 
Liebig did not pursue the subject much further, but at his suggestion 
Gladstone 4 in 1849 continued the study of the phosphorus-nitrogen 
compounds and, incidentally, of chlorophosphuret of nitrogen. In his 
papers on this body 5 Gladstone detailed a method of preparation from 
phosphorus pentachloride and ammonium chloride, and pointed out 
some of its properties — among them its decomposition in aqueous ether 
or by alcoholic alkalies into hydrochloric acid and a nitrogenous com- 
pound, deutazophosphoric acid. Gladstone adopted Liebig's formula, 
P 3 N 2 C1 5 . The correctness of this was disputed on theoretical grounds 
by Laurent and Gerhardt, 7 and the formula PNC1 2 suggested. At a 
later date Gladstone and Holmes 8 revised the work of the former 
and adopted Laurent and Gerhardt's formula, at the same time showing, 
on the basis of the vapor density, that it must be tripled : P 3 N 3 C1 6 . 
1 The following work was begun in the laboratory of the School of Pharmacy, Northwestern Uni- 
versity, Chicago, and continued in the laboratory of the United States Geological Survey. I wish to 
express my sincere thanks to Prof. J. H. Long, of the former institution, for his kindness in permitting 
me to work in his laboratory. 
2 Liebig- Wohler, Briefwechsel, Vol.1, p. 63; Ann. Chem. (Liebig), Vol. XI, 1834, p. 146. 
b The part of Wohler in this investigation seems to have consisted merely in making the analyses 
for Liebig. 
"Quart. Jour. Chem. Soc. London, Vol. II, 1850, p. 121. 
6 Ibid., Vol. Ill, pp. 135, 353; Ann. Chem. (Liebig), Vol. LXXVI, p. 74; Vol. LXXVII. p. 314. 
6 Compt. rend., Vol. XXXI, 1850, p. 356, and Compt. rend, des Trav. de Chimie, 1850, p. 387. 
7 Compt, rend, des Trav. de Chimie, 1851, p. 30 ; Ann. Chim. Phys. [3], Vol. XVIII, p. 204, note. 
8 Jonr.Chem. Soc. London, [2], Vol. II, 1864, p. 225. 
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