234 



THE PREPARATION OF 



THE CONSTITUTION OF SULPHUR MONOCHLORIDE 



If we may look upon the glycollyl intermediate compound 

 described above as a mixed anhydride of glycollic and 

 sulphurous acids, that is, as a representative of the inter- 

 mediate compounds whose existence in the case of non- 

 hydroxy acids is too fugitive to be observed, the analogy 

 between the course of the reactions when thionyl chloride 

 is used, and those with sulphur chloride, is pronounced. The 

 resemblance becomes complete when it is remarked that the 

 decomposition of the acyl thiosulphites proceeds as a reaction 

 of the first order. That such is the case has been ascertained 

 by absorbing the sulphur dioxide evolved on its decomposition 

 in iodine solution. The decomposition is conveniently carried 

 out in toluene, maintained at its boiling-point, in a flask 

 provided with a reflux condenser and gas delivery tube ; 

 the latter is branched, and each branch connected through 

 a stopcock with absorption bulbs. In this way, if a regular 

 current of carbon dioxide is passed through the flask, the 

 quantity of iodine used from time to time, and thus the 

 amount of decomposition, is readily determined by titration 

 with sodium thiosulphate. One such set of observations is 

 here given : 



Total quantity of iodine used after some hours=a=71 - 22cc. 



The fact that the decomposition of benzoyl thiosulphite 

 is monomolecular may be taken as pointing to the transient 



