cess appears to be essential for making the sulphur cyanolysable as evidenced by the acquisition of cyanolysability when ,-mercaptopyruvate is converted to the disulphide; only the latter can give the -S(S)form. This tautomerization can also occur in polysulphides and the lability of the sulphur in polysulphides with n > 3 compared with the stability of dialkyldisulphides (n = 2) again reflects the capacity to tautomerize