564 Intelligence and Miscellaneous Articles. 



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is a white powder, which is to he mixed with water, in which a por- 

 tion only of it is dissolved and the water is rendered acid ; the inso- 

 luble portion is impure phosphatide ; it is to be purified by boiling 

 for some hours in dilute solution of potash until it ceases to dis- 

 solve any chlorine; then with weak nitric acid, and lastly with 

 water. 



When dried at 212° its formula is [PH 3 N 2 0]. M. Liebig ob- 

 tained only 24* 2 7 per cent, of water by calcining this substance with 

 oxide of copper, whereas M. Gerhardt states that he has never ob- 

 tained less than 34 per cent. ; he also says that he obtained only 

 28'5 of nitrogen from 100, whereas M. Gerhardt procured 35'5. 



Biphosphamide. — If instead of submitting humid phosphamide to 

 the action of heat, it be first dried by the water-bath, it loses all its 

 hydrogen in the form of ammonia ; the residue, instead of fusing as 

 in the preceding experiment, undergoes no change of appearance. 

 When submitted to analysis, it is found to have lost half of its nitrogen 

 and the whole of its hydrogen, so that it consists of equal atoms of 

 phosphorus, nitrogen and oxygen. In order to have this compound 

 entirely free from phosphamide, it must be kept for a considerable 

 time at a low red heat. The external characters of this substance do 

 not serve to distinguish it from the preceding ; like it, it is a white 

 powder, insoluble in any solvent : it also acts like phosphamide if 

 moistened with water and exposed to heat. When fused with potash, 

 ammonia is disengaged and common phosphate left. The formula of 

 biphosphamide is PNO. 



Phospham. — When the product of the action of ammonia on per- 

 chloride of phosphorus free from water is calcined in close vessels, 

 hydrochloric acid and hydrochlorate of ammonia are disengaged and 

 a perfectly white residue is obtained, which, according to MM. Liebig 

 and W6'hler,is phosphuret of nitrogenPN 2 . According toM. Gerhardt 

 this statement is incorrect ; and it contains three things, if particular 

 precautions are not taken, viz. biphosphamide, a compound formed of 

 phosphorus, nitrogen and hydrogen, which M. Gerhardt calls phos- 

 pham, and a chlorinated compound which he has been unable to isolate, 

 but which is converted into phosphamide and hydrochlorate of am- 

 monia by contact with water. 



In order to have a product free from chlorine and oxygen, it is re- 

 quisite to operate on perfectly dry substances, and to finish the ac- 

 tion of the ammonia at a very high temperature. M. Gerhardt, 

 when operating under the same circumstances as the German che- 

 mists, could never obtain a product free from chlorine, the presence 

 of which they attributed to hydrochlorate of ammonia ; but this is an 

 error, for it is derived from the incomplete action between the am- 

 monia and the perchloride of phosphorus. 



Phospham contains 1*5 per cent, of hydrogen. MM. Liebig and 

 Wdhler attributed the water which they obtained to the humidity 

 of the oxide of copper which they employed. 



Finally, no phosphuret of nitrogen is formed by the action of am- 

 monia or perchloride of phosphorus. When the action of the alkali 

 is complete, a substance remains containing phosphorus, nitrogen 

 and hydrogen, which M. Gerhardt represents by [PHN 2 ]. 



