I860.] on Acids and Salts. 237 



down, IICIO4, and H2SO4. Bibasic characters are manifested as deci- 

 dedly by the sulphurous and sulphydric acids. 



(y.) There are four other binary compounds of hydrogen, two 

 volumes of each of which, however, contain three volumes of hydrogen, 

 namely : 



HgN Ammonia. 



HgP Phosphamine, 



HsAs Arsenamine. 



HgSb Stibamine. 



When the two volumes of phosphamine, for instance, are acted upon by 

 a red hot iron -wire, the phosphorus is absorbed by the iron, and three 

 volumes of hydrogen gas are liberated. Two volumes of chlorhydric 

 acid yield one volume of hydrogen ; two volumes of sulphydric acid 

 yield two volumes of hydrogen, while two volumes of phosphamine 

 yield three volumes of hydrogen ; and this is a most important dis- 

 tinction between the three classes of hydrides to which these three 

 gases respectively belong. Again, two volumes of gaseous ammonia, 

 when decomposed by the RuhmkorfF spark, become converted into 

 three volumes of hydrogen and one volume of nitrogen ; or the 

 original bulk of the ammonia becomes doubled. 



In the phosphorus series of oxygen acids there is but one gap, and 

 this can be filled up by the chlorine-, or the ethyl- representative of the 

 missing body. 



Brodie has ascertained that oxichloride of phosphorus CI3PO, may 

 be obtained directly by passing oxygen gas through boiling terchloride 

 of phosphorus, or trichloro-phosphamine CI3P. The union of tri-ethyl 

 phosphine EtgP, with oxygen, to form the oxide of tri-ethylphosphine 

 EtaPO, constituted one of Hofmann's earliest experiments on the 

 phosphorus bases. Proceeding to the actual oxides of phosphamine, it 

 is doubtful whether hypophosphorous acid H3PO2) has been obtained by 

 the oxidation of phosphamine ; but, on the other hand, phosphamine 

 is readily obtainable by deoxidating hypophosphorous acid with 

 nascent hydrogen ; while by oxidating hypophosphorous acid, phos- 

 phorous and phosphoric acids are successively produced. Phosphorous 

 acid HgPOa, results from the slow oxidation, and phosphoric acid 

 H3PO4, from the rapid oxidation of phosphamine. Conversely, phos- 

 phamine may be obtained by the deoxidation of each of the two last- 

 mentioned acids. Here again then is a series of naturally associated 

 and mutually convertible bodies, represented by the simplest possible 



