1867.] with the Pijro- and Tetra-phosphoric Amides^ 511 



ways, of wliicli the most noteworthy are the action of ammonia on phos- 

 phoric anhydride, of ammonia and water on oxychloride of phosphorus, 

 of alcohol or soluble bases on chlorophosphuret of nitrogen, as well as 

 the breaking down of amides of more complicated structure. It is bi- 

 basic, and forms salts which are generally very soluble, like itself, in 

 water and alcohol. 



Pyropliosplio-triamic acid, (NH^), HO^, is formed when oxychloride 

 of phosphorus is saturated with ammonia at about 100° C, and the 

 resulting mass is treated with water, or when tetraphospho-pentazotic 

 acid is exposed to the action of M^ater for some time. It is nearly inso- 

 luble in water, and so are its combinations, even those with the alkaline 

 metals. It readily decomposes most soluble salts, giving rise to com- 

 pounds in Avhich 1, 2, 3, or 4 atoms of hydrogen are replaced. With 

 slightly acid nitrate of silver it gives a white salt, P2 (^112)3 Ag 0^ ; 

 with the ammoniacal nitrate a bright yellow salt, JSTg Agg O j. 



By the action of water on the compounds of ammonia with oxychloride 

 of phosphorus, there are also produced some acid amides that belong to 

 a higher series. Grreat difficulty was experienced in being certain of 

 the purity of any specimen^ of these compounds ; hence some doubt may 

 still rest on their ultimate composition. 



Tetrapliosplio-tetramic acid, P^ (NH^)^ O^, is a solid stable body, inso- 

 luble in alcohol, but soluble in water, and combining readily with bases, 

 the amount of hydrogen replaced appearing to vary from 1 to 6 atoms. 



Terammoniated TetrapJiospho-diamic acid, (^112)0^3 0^^.— This 

 is a viscid liquid, insoluble in alcohol, but very soluble in water. It 

 forms a liquid combination with ammonia ; but metallic salts appear to 

 break it up into a variety of compounds. By the action of heat, boiling 

 water, strong acids, or allcaline carbonates, tetraphospho-tetramic acid 

 may be produced from it. Among the bodies formed when it is heated 

 per se is a white substance, insoluble, or nearly so, in cold water, having 

 the ultimate composition PNH^ O3. This is at once transformed into 

 pyrophospho-diamic acid by hot water, or dilute acids. 



Tetraphospho-pentazotic acid, P^ N", Hg is formed when oxychloride 

 of phosphorus is fully saturated with ammonia, and the resulting mass 

 is heated at about 230° C, and washed with cold water. It is an 

 insoluble body, capable of decomposing metallic salts. One atom of 

 hydrogen is replaceable by potassium or ammonium. "When treated 

 with slightly acidulated nitrate of silver, it gives a tetrazotic salt, 

 P_j Az, which, when decomposed by mineral acids, yields tetra- 



phospho-tetramic acid and other compounds. 



Amidated Occychlorides of Phosphorus. — The oxychloride will absorb 

 either 2 or 4 molecules of ammonia ; and there can be little doubt that 

 the resulting white solids consist of chloride of ammonium mixed with 

 P(NH2) CI, O in the one case, and PCNH,), CI O in the other, but I 

 have never succeeded in separating them in a condition fit for analj'sis. 



