Poly(tetrafluoroethylene) has been reduced to polyethylene by the action of lithium in liquid ammonia. The product has been characterized by infra red and $\sp{13}$C-NMR spectroscopy and by differential scanning calorimetry. The product is identified as linear, high density polyethylene. A mechanism for the reduction sequence is proposed Thermal disproportionation and photochemistry of organic polysulfides have been studied by NMR and EPR spectroscopy in the temperature range of 373K to 77K. EPR spectra showed that photolysis of cyclic polysulfides, norbornane trithiolane and norbornane pentathiepane at 366 nm, in frozen solution gives high yields of radical pairs and less amounts of simple radical species. In the reactions studied here, radical mechanisms dominate in both the thermal and photochemical reactions. No evidence for ionic mechanism has been observed in any of these reactions
