RICHARDS AND MERIGOLD. 



ATOMIC WEIGHT OF URANIUM. 



879 



In order to obviate the difficulty and exclude air a glass jacket was 

 slipped over the joint between the tubes. The construction and use of 

 this jacket will be made clear by reference to the accompanying drawing. 



Section of Subliming and Bottling Apparatus. 



A, outer porcelain tube fitted with ground glass joint B; C, inner porcelain tube 

 with ground-glass stopper D ; E, boat containing oxide and carhon ; F, furnace ; 

 G, glass jacket; H, H, H, H, packing of asbestos wool; I, weighing bottle; L, 

 tube for admitting nitrogen, sliding within tube M through rubber connection N, 

 and carrying at its end stopper of weighing bottle; P, sublimate; R, rod for 

 removing sublimate. 



The jacket was drawn down at the ends, so as to fit the porcelain 

 tubes A and C as well as possible, and the spaces between the tubes and 

 the jacket were packed tightly with asbestos wool. This packing makes 

 a joint sufficiently tight to withstand a pressure equal to that of eight or 

 ten centimeters of water. The jacket was provided with a long tube, M, 

 within which slid a second tube, L, connection being made by 'means of 

 the short piece of rubber tubing, N. To the end of the inner tube was 

 attached, by platinum wires, the stopper, O, of the weighing bottle. The 

 outside diameter of L was very little less than the inside diameter of 

 M, thus leaving very little space between the walls of the two tubes. 

 For this reason, and also on account of the length of the tube M, — about 

 fifteen centimeters, — there was little danger of bromine diffusing up in 

 sufficient quantities to attack the rubber connection, N. Even if this 

 were the case there could be no possibility of contamination of the sub- 



