Tetramethylthiuram disulfide (TMTD), together with a sufficient amount of zinc oxide, is the simplest and most efficient vulcanizing agent known for introduction of sulfur crosslinks into rubber. No other combination approaches it in efficiency over a wide range of temperatures, although under limited conditions sulfur cures can be obtained with approximately as high a crosslink density per mole of vulcanizing agent. The stoichiometry of vulcanization with this curative has been explored in some detail in recent work of Scheele and coworkers. They have confirmed the observation by Jarrijon that during vulcanization dithiocarbamate is formed equivalent to close to two-thirds of the TMTD taken. The generality of this result was established in an exhaustive series of experiments, covering a range of structures of thiuram disulfide and of polyolefin, of temperature, and of concentration of reactants.