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PAGE 



The "Challenger" work successfully completed with 

 it. 



Account of it by Professor Tait in "Challenger" 

 report on Chemistry and Physics. 



No. 27. ON AN APPARATUS FOR GAS-ANALYSIS. [From 



Phil. Mag. January, 1874] . . .... 390 



This apparatus was designed for use on the "Chal- 

 lenger" in case it should be desired to analyse speci- 

 mens of gas proceeding from any natural source, such 

 as hot springs or volcanoes, and to permit the conduct 

 of such analyses in a laboratory on board-ship. 



It was constructed according to my drawings and 

 instructions by the celebrated Dr Geissler of Bonn and 

 is a chef-d' cBiivre of glass workmanship . . . 390 



Illustration of the instrument . . . .391 



Detailed description of its parts and their dimen- 

 sions ........... 392 



Description and illustration of the capillary parts 

 and the stopcocks ....... 393 



Manner of introducing the gas into the measuring 

 tube . . . . . . . . . . 394 



Description of supposed example when the oxygen 

 is determined by absorption ..... 395 



The same, when the oxygen is to be determined 

 eudiometrically ........ 396 



Illustration of compact and convenient portable 

 apparatus; also constructed to my design by Dr 

 Geissler, for furnishing the electrolytic gases of water, 

 whether mixed or separate ...... 397 



Description of the mahogany case into which the 

 apparatus for gas-analysis is fitted, for use and for 

 transport ......... 398 



As the samples of gas boiled out of specimens of 

 sea-water in the ordinary routine of my laboratory 

 work were all preserved for analysis after the return of 

 the expedition, no opportunity presented itself for 

 using this apparatus during the voyage. 



Later, it was used by my old friend, the late Pro- 

 fessor Sir Walter Noel Hartley, for all his gas analyses 

 in preference to any of the existing larger apparatus; 

 and he informed me that the results obtained with it 

 were perfectly satisfactory. 



