Sealed thick-walled capsules

Studies of aqueous systems using the sealed thick-walled capsules do not provide any information about the pressure. The influence of dissolution of the capsule wall on die composition and properties of the system under study is another complicated problem. 

The first method was employed with both neptunium and plutonium when these metals were tested for superconductivity down to temperatures of about 0.75°K [1]. Brass capsules of 1 mm wall thickness were used which had at one end platinum—glass seals through which the platinum wires for the current-potential measurement were passed. The active specimens were inserted into the capsules inside a glove box in which the electrical contacts were also made and in which the capsule was filled with helium gas and then sealed off. Prior to its introduction into the glove box, the capsule had been covered with a layer of shellac. After sealing off, the capsule was immersed in acetone which dissolved the shellac and in this manner the contamination sticking to the outside of the capsule was removed. 

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