CHEMISTRY IN THE TELEPHONE INDUSTRY 



607 



In connection with the water-soluble impurities, an interesting prob- 

 lem in osmosis arose. The absorption of water by rubber is found to be 

 a direct function of its content of water-soluble substances and an in- 



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Fig. 1 — Apparatus for observing rate of oxygen absorption. Rubber, asphalt, or 

 paint film to be studied is placed in bulb A (enclosed in thermostat not shown) and 

 apparatus is filled with pure oxygen. By operation of the manometer C, water is 

 electrolyzed in bulb B, generating gas automatically in quantity just sufficient to 

 maintain oxygen in buret D constantly at atmospheric pressure. 



verse function of the salt content of the external water. Thus a sheet 

 of raw rubber which is produced by the evaporation of latex, and there- 

 fore contains all the natural water-soluble impurities, will, upon immer- 



