[boswell] the constitution OF RUBBER 43 



The part of the oxidation product insoluble in carbon bisulphide 

 was shaken for twenty-four hours with carbon bisulphide to remove 

 all the carbon bisulphide soluble and filtered. This was dissolved in 

 acetone for the purpose of precipitating it, but the precipitate with 

 methyl alcohol was of such a consistency that it could not be separated 

 effectively from the solvents. The whole was evaporated at room 

 temperature under suction and gave a hard, brittle and transparent 

 mass. 



Analysis of Compoimd Soluble in Carbon Bi-Sulphide. 



Action of Hydrogen Peroxide and Iodine on Rubber. — Experimental 

 Work by R. R. McLaughlin and R. R. Parker. 



5 g. rubber dissolved in 125 c.c. carbon tetrachloride, 125 c.c. of a 

 3% hydrogen peroxide solution, 100 c.c. of a 2% solution of iodine in 

 carbon tetrachloride were placed in a glass stoppered bottle and 

 shaken for two weeks at room temperature. It was allowed to stand 

 for twenty-four, hours when it separated in two layers. The whole 

 was filtered at the pump, requiring several hours, washed with carbon 

 tetrachloride, dried in air at temperature not above 30°C. The 

 product was then rubbed up in a mortar and extracted with carbon 

 tetrachloride to remove all free iodine, dried, dissolved in ethyl 

 acetate and filtered. The residue on the filter was washed several 



