470 ON THE THEORY OF NITRIFICATION. [XX. 



APPENDIX. 



ON THE THEORY OF NITRIFICATION. 



IN connection with the foot-note on page 465 the following sketch 

 of the theory of nitrification there indicated seems called for, the 

 more especially as it will be seen that the late Professor G. C. 

 Schaeffer of Washington apparently anticipated me in certain points 

 therein. It was in the Amer. Jour. Science for May, 1848 (page 

 408), that I referred to Gerhardt's observation that the so-called 

 protoxide of nitrogen corresponds to biphosphamide, PNO, and is 

 NNO, a nitryl derived from nitrate of ammonia by the removal of 

 2H,0, and capable, when heated in contact with an alkaline 

 hydrate, of regenerating ammonia and a nitrate. I then called 

 attention to the similar decomposition of nitrite of ammonia, 

 which by the loss of 2H,O yields nitrogen gas, and remarked that 

 the gas thus obtained, " apparently identical with that of the at- 

 mosphere, is really composed of two equivalents of the element sustain- 

 ing to each other the same relations as in nitrous oxide" or in other 

 words representing respectively the nitrous and the ammoniacal 

 conditions. This view of the constitution of gaseous nitrogen was 

 again set forth, in September, 1848, in the paper quoted above, as a 

 means of explaining the apparent anomaly in the equivalent volume 

 of nitrogen. The obvious conclusion that gaseous nitrogen might 

 (after the manner of nitrous oxide) regenerate ammonia and a 

 nitrite by assuming the elements of water, 2H0, was not insisted 

 upon. It was, however, for years so familiar to me and so often set 

 forth in my lectures on chemistry before the medical classes at the 

 University Laval at Quebec, that I spoke of it in the above paper in 

 March, 1861, as a view which I had elsewhere suggested, though 

 this was, I believe, the first time that it had been enunciated by me 

 in print. In further explanation of the subject I published in the 

 Amer. Jour. Science for July, 1861 (page 109), a note in which, after 

 describing the generation of ozone or active oxygen by passing air 

 through a solution of permanganic aciol, and the production of a ni- 

 trite from air thus ozonized, I referred to the conversion of gaseous 

 nitrogen, as above, into ammonia and nitrous acid, and a<Mr<] : 

 " From the instability of the compound of these two bodies, how-\vr, 

 it becomes necessary to decompose the one at the instant of its forma- 



