336 Albert P. Mathews 



I think the former, with some of the molecule having quadri- 

 valent oxygen, is perhaps the more probable. I have taken 

 the highest possible value of "a" for nitrous oxide. In 

 nitric oxide two valences per molecule are the most that can 

 be assigned by this method. This would mean that both 

 elements were monovalent, but as there is other evidence 

 that oxygen is univalent in its elemental form, this formula 

 is not entirely improbable. The valence of nitrogen in nitric 

 dioxide is quite uncertain. In the amines there can be hardly 

 a doubt that it is trivalent, or at times pentavalent with two 

 free valences on the nitrogen. This is the case in ammonia 

 and methyl amine, both of which associate. All of the 

 critical data of the amines were determined by Vincent and 

 Chappuis and I believe their figures are uniformly a little too 

 low. In aniline the nitrogen appears to be pentavalent, 

 but some association occurs. The results are not, then, very 

 satisfactory for these compounds, but they indicate very 

 clearly, however, that nitrogen is either monovalent, tri- 

 valent, or pentavalent, as it is supposed to be. 



4. Phosphorus 



I have found but a single phosphorus compound in which 

 the critical data have been directly determined, although 

 one or two other cases were reported in my paper on the 

 valence of chlorine, in which the critical data had been com- 

 puted from the surface tension. 



In phosphoretted hydrogen the phosphorus is apparently 

 pentavalent, having two free valences, "a" is given by 

 Leduc and Sacerdote as 0.00939 an d from this the valence 

 of 8.6 is computed. Were the phosphorus pentavalent the 

 total number of valences would be eight. It might be, 

 however, that the phosphorus was heptavalent, but only a 

 few of the molecules had the two pairs of reserve valences 

 open at the same instant. In the chlorine compounds it ap- 

 peared that the phosphorus was probably heptavalent. I 

 think the only certain conclusion is that the valence is greater 

 than three. 



University of Chicago 



