( 456 ) 



0.0013 (temp. 60-.1). If a large excess of NaOH is added from the 

 commencement, the transformation velocity again reaches the same 

 lignre as for pnre water; for 10 mols. of NaOH, /t- := 0.0022. 



We are dealing here with a 8{)ecial unknown intlucnce of the 

 added substances; these certaiiily will modify the concentration of 

 the molecules undergoing change, [either the salt mol. or the acid 

 ion] by the diminution of the electrolytic dissociation, but as the 

 reaction constant is independent of the concentration, this cannot 

 explain the fall of that constant. 



In the dry state the salt is more permanent than in solution, for 

 after heating for al;)Out 2\/., hours at 60" it was not perce})tibly 

 decomposed and gave no odour of HON. At 70° it turns darker 

 after some time and evolves HCN ; the decomposition is then evidentlj^ 

 more complicated. 



Finally, the decomposition velocity was also determined in metliyl- 

 and ethylalcohol ; that in ethylalcohol is the smallest whilst yiethyi- 

 alcohol stands between water and ethylalcohol. I found at 60'' 

 for lo/o solution in water 0.0023, in absolute methylalcohol 0.0017, 

 in 977„ methylalcohol 0.0018, for a ^V/„ solution in 97"/; ethyl- 

 alcohol 0.001°, for 507„ ethylalcohol 0.0013. Achhtion of water 

 consequently accelerates the transformation. 



The intensity of the colour of a solution containing the same amount 

 of sodium salt is largest for ethylalcohol, smaller for methylalcohol 

 and smallest for water ^); this phenomenon is undoubtedly connected 

 with the fact that the electrolytic dissociation of salts in the said 

 solvents increases in the order indicated. 



Amsterdam, Dec. 1903. Org. Chem. Lah. Univ. 



Chemistry. — Prof. H. W. Bakhuis Roozeboom presents a communi- 

 cation from himself and Mr. A. H. W. Aten on : "Abnormal 

 wlvhiliti/ lines in binary midures owim] to the existence of 

 compounds in the solution.'' 



(Communicated in the meeting of December 19, 1903\ 



Last year '^) when engaged in a research on acetaldehyde and its 

 polymer paraldehyde, I investigated the connection between the equi- 

 libria of phases of substances which in the liquid and gaseous con- 

 dition consist of mixtures of tAvo kinds of molecules in equilibrium, 

 and the equilibria of phases in binary mixtures. 



1) The solubility of the salt in ethylalcohol is also the smallest. 



2) Proc. Oct. 1903, p. 283. 



