HYDROLYSIS of the compound obtained by interaction of P-toluidine and thiocarbonyl tetrachloride (Connolly and Dyson, J., 1934, 822) gave p-tolylcarbylamine and 9- tolylthiocarbimide; if isomeric change be precluded, this is evidence for an RNC-link in the original compound. Experiments hereinafter described show that this link is probably due to intermediate ring formation (111) during hydrolysis, since the substance for which