Eobertson. — On certain Maxima and Minima. 



473 



zene or phenol solution. In the case of the esters, which 

 have the general formula 



OB' 



I 

 E • C = 



the alkyl group E' appears to hinder the association. 



For the nitriles E ■ C— N there is the possibility of the 

 formation of an immense number of complexes. 



Now, seeing that all the compounds which behave in the 

 manner described possess a double or treble linkage, it is 

 reasonable to suppose that the nitroparaffins also are of this 

 type. The following formulae, out of the number that have been 

 proposed for these compounds, show an ethylene linkage : — 



„ 



(1.) E • CH 2 • N 

 OH 



% 



O 



(2.) E • C = NOH 

 O 



(3.) E • CH =: N • OH 



The latter two, however, are the more probable, for several 

 reasons. The hydroxyls explain the strong association in 

 the liquid state (1-82 Traube) ; the association of the vapour 

 and the phenomenon of the boiling-points of the series is due 

 to the double linking. This structure also furnishes an ex- 

 planation of the acid nature of these compounds ; (2) makes 

 these compounds exactly similar to the fatty acids, except 

 that the group =NOH replaces the group =0. 



(b.) The Boiling-points of the Alcohols : This series be- 

 haves in quite a different manner. The necessary data are 

 shown in Table XIII. 



Difference. 



12 



19 



20 



20 



20 



19 



19-5 



18 



17-5 



