2i 4 SCIENCE PROGRESS 



solution of potassium ditolylamine with tetramethylammonium 

 chloride in an atmosphere of nitrogen the following reaction 

 takes place : 



(CH 3 C 6 H 4 ) 2 N . K + (CH 3 ) 4 NC1 = KC1 + (CH 3 C 6 H 4 ) a N . N(CH 3 ) 4 . 



The resulting compound ditolylaminotetramethyl am- 

 monium crystallises from pyridine in greenish yellow leaflets 

 and is hydrolysed by water to ditolylamine and tetramethyl- 

 ammonium hydroxide, and is therefore a salt in which the 

 fifth valency of one nitrogen atom is satisfied by the valency 

 of another nitrogen atom. 



Datta and Chaterjee (/. Amer. Chem. Soc. 191 7, 39, 485) 

 in their studies on halogenation describe cases of direct intro- 

 duction of an iodine atom into the molecule of an aromatic 

 hydrocarbon by acting in the presence of nitric acid, whereby 

 the latter is reduced to oxides of nitrogen. A certain amount 

 of nitration is liable to take place at the same time, especially 

 in the case of the higher hydrocarbons. With the aliphatic 

 hydrocarbons the tendency to hydrolyse is so great that the 

 iodo derivatives are destroyed by the nitric acid as soon as 

 they are formed, but it has been found possible under certain 

 conditions to obtain small yields of iodo derivatives of some 

 of the higher hydrocarbons. The following compounds were 

 actually obtained : iodobenzene from benzene, 0- and £-iodo- 

 toluenes from toluene, o- and />-iodoxylenes from xylene, etc. A 

 small quantity of iodohexane was also obtained from hexane ; 

 naphthalene gave a mixture of iodo and nitronaphthalene. 

 Datta and Prosad (/. Amer. Chem. Soc. 191 7, 39, 441) have 

 also found that iodine can be introduced into phenols and nitro- 

 phenols by acting upon these substances with nitrogen iodide 

 or a solution of iodine in potassium iodide in presence of 

 ammonia ; under the latter conditions the iodonitrophenols 

 produced are obtained in the form of their ammonium salts. 

 Treated in this way phenol gave tri-iodophenol, o-cresol gave 

 di-iodocresol and m-cresol gave tri-iodo-ra-cresol, while o- 

 nitrophenol gave the ammonium salt of di-iodonitrophenol. 

 A great many other examples are given, but for these reference 

 must be made to the original. 



In continuation of his work on the chemical constitution 

 of the vitamines R. R. Williams now states (/. Biol. Chem. 

 191 7, 29, 49 s ) that since the needle crystal form of 2 hydroxy- 



