152 
CONTRIBUTIONS TO CHEMISTRY AND MINERALOGY. [bull. 167. 
Ratio P : 
N:Ag. 
P. 
N. 
Ag. 
1 
2 
3 
4 
7 : 
7 : 
7 : 
7 : 7.04 
f P7N7O15IL) OT Agrt in 
16.55 
16.77 
16.44 
16.17 
16.40 
16.21 
16.35 
16.57 
16.27 
16.41 
16.64 
16.35 
7.43 
7.53 
7.44 
56.99 
57.77 
56.61 
57.97 
58. 76 
58.09 
57. 51 
58.30 
57.27 
57. 35 
58.16 
57.14 
: 6.93 | P 7 N 7 0hH 7 7Ag (i 93 
( Found 
f P 7 N 7 15 H 8 .T9Ag 7 . 21 
: 7.21 P 7 N 7 14 H 6 . 79 Ag 7 . 31 
(Found 
( P 7 N 7 0i 5 H 8 .pAg 7 08 - - 
: 7.0S P 7 N 7 Oi 4 H 6 . 92 Ag 7 .o8 
( Found .. 
[ P7N7O15M8 '»7Ag 7 o-l 
: 7.03 1 P 7 N 7 0i 4 H 6 ..7Ag 7 03 
( Found 
These figures show beyond question that the acid has the open form 
P 7 N 7 15 H 1G . 
The decomposition of the sodium salt by acetic acid gives rise to a 
considerable amount of tetrametaphosphimic acid, characterized by its 
crystalline form and that of its salts. 
Higher Acids. 
Of the higher acids of the series but little can be said. The oil 
remaining over from preparation of chloronitrides, and which has a 
mean molecular weight nearly corresponding to PuNnOl^, on saponifi- 
cation gives a mixture of sodium salts which are precipitated by alco- 
hol in a decidedly viscous form, and which are decomposed by acids, 
giving tetrametaphosphimic, diimidotriphosphoric, and triimidotetra- 
phosphoric acids. They were not further investigated. 
Amides of Metaphosphimic Acids. 
Amides of P 3 N 3 O g H g . — Strong ammonia gas acts slowly on a solution 
of P 3 N 3 C1 G in absolute ether, the product being at first ammonium 
chloride and the chloramide, P 3 N 3 <; . This remains in solution 
X (NH 2 ) 2 
and is gradually attacked further, but is the only product of the reac- 
tion which is soluble in ether ; by further action of ammonia the chlo- 
rine is further substituted, but never completely, and the reaction 
product is thrown down, mixed with ammonium chloride. On washing 
this with alcohol, dissolving in water, and treating with enough sil- 
ver nitrate to precipitate the chlorine, a solution is obtained which, by 
fractional precipitation with silver nitrate, gave the silver salt of an 
amide with the ratio P : N : Ag = 3 : 6.27 : 2.01. An ethereal solu- 
/01 4 
tion of P,N- 
*(NH 2 ) S 
shaken with sodium hydroxide, gives the sodium 
