MIXTURES OF IIYDIIOCHLOIUC AOlD AND METHYLETHER. 30 7 



witli a miiiimum-vapoiir-jjressure combiue tliis witli a maximum iu the 

 critical températures. Tliey beloug therefore to a type which so far lias 

 not been fully iuvestigatecl. 



It was of first importance duriug the investigation to keep in view 

 tlie possibility of irréversible chemical action, as tins would naturally 

 entirely aller tlie cliaracter of the mixtures. Eriedel had not observed 

 chemical action, but this did not give any warrant wilh regard to the 

 beliaviour of the mixtures at higlier températures. 



In the course of the work it was found that even below 100° C. a 

 chemical action takes place which iucreases in rapidity as the tempe- 

 rature rises. The cliief products of tlie action are methylchloride and 

 water. As the critical températures of the majority of the mixtures lie 

 above 100° an important part of the research became impossible and it 

 appeared that the combination of methylether and hydrochloric acid is 

 uusuitablc for the purpose of exploring the complète diagram for the 

 type to which it belongs. At the same time there are so very fewr epre- 

 sentations of tins type which lend tliemselves to an investigation in the 

 critical région, that one cannot afford to reject the combination altoget- 

 ther. It is proposed shortly to undertake the investigation of mixtures 

 of acétone and cldorofoj'ui. 



At lirst 110 chemical action had been noticed : it is possible that the 

 action dépends upou the présence of moisture or otlier impurities which 

 liappened to be présent in smaller quantity in the first experiments than 

 later. It is more probable however that the différence is due to the first 

 mixtures containing little acid the later mixtures gradually more and 

 more. The velocity of the chemical action must liave been correspon- 

 dingly smaller and the results above 100° obtained with thèse mixtures 

 need therefore not be completely rejected, altliough no great value 

 must be attacted to the actual numbers. It is possible that the existence 

 of chemical action at higli températures inay give rise to some doubts 

 as to whether the phenomena observed by Eriej:)EL and myself, even 

 those far below 100°, may be ascribed to pure mixing or whether thèse 

 two are intluenced by the same forces. I believe thèse doubts to be un- 

 founded. Whatever we may think the inolecular condition of the mix- 

 tures to be, — whether we assume the formation of double molécules or 

 not, — the essential différence betweeu the progressing chemical réaction 

 which gradually changes the condition and the character of the mixtures 

 ou the one side and the forces which bring about the immédiate equili 



2U* 



