188 



Prof. W. Ramsay and Dr. M. W. Travers. 



argon. The gas issuing from the calcium . tube passed through a tube 

 S, containing soda-lime, and over copper oxide in the tube L, on 

 its way to the gasometer D. Since at the end of the operation the 

 system of tubes between the gasholders C and D contained argon, in 

 order to avoid loss, the circuit was placed in communication with a 

 Topler pump T, through the stopcock k. The space between the stop- 

 cocks / and / was exhausted at the commencement of the operation,, 

 the exhaustion being continued till the greater part of the hydrogen, 

 which is always evolved when a mixture of magnesium and lime is 

 heated, had been given ofY. 



When it was necessary to suspend operations, the taps / and / were 

 closed, the tap k was opened, and the argon was taken into the pump 

 and delivered into the vessel V which covered the upturned end of the 

 capillary tube of the pump. From V the argon could be drawn into- 

 the small gasholder E, which contained mercury, and which could also- 

 be placed in communication with the system through which the gas, 

 passed on its way from C to D. 



These operations were repeated until the gasholder D contained 

 about 15 litres of argon. The whole of this argon was then liquefied 

 in an apparatus of which fig. 2 is a representation. The argon 



FIG. 2. 



entered through the tube a into the bulb &, of some 25 c.c. capacity,, 

 surrounded by liquid air contained in a double-walled vacuum jacket. 

 The air was made to boil under a low pressure of a few centimetres of 

 mercury by means of a Fleuss pump attached to the tube c. The 

 argon rapidly and completely liquefied to a colourless mobile liquid ; it 

 showed no absorption spectrum. Its volume was about 17'4 c.c. By 

 turning the tap d it was placed in communication with the first of the 

 series of mercury gasholders, e ; the reservoir was then lowered so as 

 to remove the lower-boiling portions of the liquid. During this dis- 

 tillation, which took place at constant temperature, the pressure on 

 the boiling air was kept as low as possible. This gas subsequently 



