THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



JANUARY 1874. 



I. On an Apparatus for Gas-analysis, 

 By J. Y. Buchanan, Chemist on board If.M.S. ' Challenger f * m 



[With a P.late.] 



AVERY important subject of investigation in the chemistry 

 of the ocean is the nature and quantity of the atmospheric 

 gases dissolved in it. These are extracted by boiling in vacuo 

 in an apparatus recently described by Jacobsenf, and at the end 

 of the operation are obtained hermetically sealed in a glass tube, 

 in which they are capable of indefinite preservation. Although 

 it would be absurd to waste time in making necessarily imper- 

 fect analyses of valuable specimens at sea, which are capable of 

 being kept and analyzed with the greatest accuracy on shore, still 

 cases might occur during a three years' voyage where it would be 

 very desirable to make an approximate analysis of a specimen of 

 gas, not necessarily proceeding from sea-water, but, for instance, 

 from hot springs or volcanoes on shore. 



The first desideratum for such an apparatus for use on ship- 

 board appeared to be freedom from a mercurial trough. All 

 existing apparatus, besides having this source of inconvenience, 

 were far too large and cumbrous to be at all suited to the modest 

 allowance of laboratory space available on board ship. What 

 seemed to give most promise of success was in some way or 

 other to adapt the original Ure's eudiometer to the purpose. 

 The form of apparatus finally adopted is that represented in 

 Plate I. fig. 1. It was constructed, according to my drawings 



* Communicated by the Author. 



t Ann. der Chem. und Pharm. vol. clxvii. p. 1. 



Phil. Mag. S. 4. Vol. 47. No. 309. Jan. 1874. B 



