at the Royai Institution, 1908-1916 779 



exhaled to have been about 250 c.cm. per day but only 100 c.cm. in 

 his own case. Incidentally, it was noticed that all the methods in use 

 for removing oxygen from air by means of reducing agents give rise 

 to the production of a small proportion of hydrogen. 



As many organisms incite fermentations which give rise to hydro- 

 gen, it is only to be expected that this gas should be constantly pro- 

 duced under natural conditions. 



In studying the composition of the gases condensed from air by 

 charcoal at liquid-air and liquid-hydrogen temperatures, a series of 

 significant observations have been made on alterations in the equi- 

 librium following variations in the composition of the condensed 

 material ; what appear to be new conditions of relative volatility have 

 been noticed which are indicative of some sort of molecular aggrega- 

 tion, for example, between hydrogen and nitrogen or carbonic oxide. 



Diffusion Phenomena. 



In a recent lecture (1915) reminiscent of Delville and also of 

 Graham, a series of striking illustrations were given of the diffusion 

 of hydrogen through heated platinum and palladium, showing also 

 the different extents to which this gas is present in the flame of 

 a Meker burner, at different heights. The diffusion of helium and 

 somewhat less readily of neon and scarcely of hydrogen through 

 heated quartz was also demonstrated. 



An auspicious foundation has also been laid of a method — of 

 course involving the use of liquid air — of studying diffusion through a 

 film of indiarubber, only about O'Ol mm. thick, under a pressure 

 difference of one atmosphere between the two sides. Hydrogen 

 passes through such a film at four times the rate of air and carbon 

 dioxide at least ten times as fast. It is also permeable by water 

 vapour, which passes through about three times as rapidly as air. 

 Ammonia and the vapours of chloroform and ether permeate the 

 membrane very quickly. 



Carbon Monosulphide. 



A chemical inquiry of great importance, only possible with the 

 assistance of liquid air, is that relating to carbon monosulphide, CS. 

 the sulphur compound corresponding to carbon monoxide, CO. 

 Many unsuccessful attempts have been made in the past to prepare 

 the compound. All ordinary methods have led to the production, at 

 most, of a solid substance which is clearly a condensed or polymer- 

 ized form (CS)j; of the true monosulphide. 



The boiling-point of carbon monoxide being - 190° and its 



