No abstract

give up their sulfur to the rubber. The formation of thiozonides is illustrated by the following equation: 2R-NH2 + 4S -> R-NH-S-S-S-NH-R + H2S By this scheme, the true accelerator is produced together with hydrogen sulfide by the reaction of the amine and sulfur. Such an explanation necessarily

and are unable to tell how to avoid them. Chloroform, which is a good solvent for the tetrabromide, was tried, but although no precipitate came down, emulsions were formed.4-Two errors in the original articles are pointed out, relative to the amount of potassium iodide used.5-The results of several analyses of purified rubber are given, which show differences from 0.15 to 24.27 per cent.6-If vulcanized samples are treated with alcoholic sodium hydroxide in addition to the acetone extraction, it is found that they do not dissolve in the tetrachloroethane within 3 days' heating. By adding lime to the solvent and rubber they can be dissolved in about 12 hrs.7-Titration of the hydrogen bromide with alkali has no special advantages over the iodate method described in the original article. 8-The method requires further study and elaboration before it can be used with accuracy.

leather of pH = 9 gained 13.8 per cent in weight even though it lost some tannin, showing a very pronounced oxidation of the alcohol followed by aldehyde tannage.

No abstract