230 Journal of the Astatic Society of Bengal. [May, 1907. 



stability due to the compact nature of tlie ring structure could not 



be imparted to it. 



For want of a better source of cold, the amyl iodide was 

 cooled by a freezing mixture composed of equal parts of crystal- 

 lized calcium chloride and ice, which produced a temperature of 

 about — 30^C- Much iodine was libei^ated and traces of the form- 

 ation of a yellow compound were apparent, although no sensible 

 quantity could be collected. A slight alteration was then made in 

 the experiment by allowing chlorine cooled by passing through a 

 spiral tube surrounded by a freezing mixture to act upon a cold 

 chlorofonn solution of anyl iodide, so that this time both the 

 reacting substances were at about — 30^0. There was no liberation 

 of iodine, and a heavy yellow crystalline precipitate appeared at 

 the bottom of the test tube in which the reaction was taking place. 

 N-butyl, n-prop3'l and isopi'opyl iodides gave the same sorts of 

 precipitates, ethyl and methyl iodides, howevei*, giving rise only 

 to liberation of iodine. The temperature for the formation of the 

 iodochlorides of the lower alkyl iodides is evidently still lower. 

 The iodochlorides of propyl, isopropyl, butyl and amyl iodides 

 decomposed on being kept at the laboratory temperatures within 

 about a quarter of an hour, wath the formation of a reddish-bi'own 

 liquid. The isopropyl iodocliloride w^as analysed by heating in a 

 sealed tube with nitric acid and silver nitrate, the 'mixed silver 

 halides being converted into silver chloride by heating in a bulb- 

 tube in a current of dry chlorine. 



•3594 grammes of the substance gave "788 grammes of the 

 mixed silver halides which, on ignition in chlorine, was converted 

 into 'OSBS grammes of silver chloride. 



Percentages found :— CI = 30*9 ; I = 50-8. 



5? 



calculated (for CgH^IClg) Cl ^ 29-5 ; I = 52-7 



In this stage of the experiment, I came across Werner's paper 

 on *' Derivatives of polyvalent iodine, " which appeared in the 

 Journal of the Chemical Society for last November, and in which 

 the author alludes to Thiele and Peter's paper published in the 

 Berichte der Deutscben chemischen Gesellschaft for 1905,^ under 

 the title of '' On some aliphatic iodo and iodoso chlorides," as a 

 very interesting communication. In this paper, the authors des- 

 cribe the isolation of a number of aliphatic iodochlorides which 

 were formed by allowing a solution of chlorine in a mixture of 

 carbon tetrachloride and light petroleum to act upon the alkyl 

 iodides cooled by a carbon dioxide and ether mixture. The methyl 

 iodochloride is comparatively stable, melting with decomposition 

 at 28'^0, while the higher iodochlorides decompose at still lower 

 temperatures, the sec-butyl iodochlorides being formed only in 

 liquid air and decomposing above— lOO^C. On perusal of Werner's 

 account of Thiele and Peter's work, as well as the abstract of their 

 paper in the J.C.S., one gets the impression that all these com- 



i pp 28-42-45. 



