102 PROCEEDINGS OF THE AMERICAN ACADEMY 



X. 



CONTRIBUTION FROM THE CHEMICAL LABORATORY OF 

 CLARK UNIVERSITY, WORCESTER, MASS. 



ON BIVALENT CABBON. 



FIRST PAPER. 



By J. U. Nef. 



Presented May 11, 1892. 



Among the constantly increasing compounds of carbon, there is 

 but one substance in which the presence of a bivalent carbon atom 

 is pretty generally accepted, and which is always put forward as 

 the sole exception to the otherwise constant tetravalence of this 

 element, namely, carbonic oxide. For a substance possessing two 

 free affinities,* OO, carbonic oxide is however a remarkably inert 

 compound, since it absorbs chlorine only very slowly in diffused 

 light, f and if allowed to stand for weeks in the sunlight with one 

 molecule of bromine, only a very slow and incomplete reaction 

 takes placet 



Carbonic oxide does not react with iodine or with the haloid 

 acids. It was found by a special experiment that hydriodic acid 

 does not react on carbonic oxide at a temperature of 200°, although, 

 as is well known, this substance adds itself more readily to un- 

 saturated compounds than any of the other haloid acids. 



Carbonic oxide is thus much less reactive than the majority of 

 the olefine derivatives, many of which form in the cold, and in the 

 absence of light, addition products with the above named reagents. 

 This fact depends, as I have already shown in the case of acetacetic 

 ether, § on the law that an unsaturated compound forms addition 



* It is improbable that the two extra affinities in carbonic oxide exist free: 

 they probably polarize, or mutually saturate each other as in ethylene, so that 

 it is legitimate to speak of a nascent carbonic oxide. 



t Davy, Gilbert's Annalen, XLIII. 296. 



\ Emmerling, Ber. d. Chem. Ges., XIII. 873. 



§ Ann. Chem. (Liebig), CCLXVI. 52. 



