( 118 ) 



cylinder was always kepi closed, while con trol lino- experiments with 

 an entirely similar cylinder of pure myrislic acid showed that by 

 tliis alone no lasting adsorption of odour is produced. 



Adsorption of odour appeared to be entirely absent with some 

 materials (porous porcelain, carbon, ebonite, steel, iron), with others 

 to exist in a small degree (aluminium, silver, sulphur), with others 

 again to exist in a more or less considerable degree (tin, copper, 

 nickel, glass, lead alloyed with tin, lead). Judging by the impression 

 received immediately after the experiment, the substances may be 

 arranged in the following series of increasing condensation : 



Porous porcelain*, arc lamp carbon, ebonite*, steel, iron, alumi- 

 nium*, silver*, sulphur*, tin, copper, nickel, glass, lead alloyed with 

 tin, lead. 



The substances marked with an asterisk are not entirely odourless 

 at the temperature of the room. 



The first members of this series have no adsorption odour whatever 

 after the muscon-containing air has passed for five minutes, nor do 

 they acquire it by heating. The final members, especially tin, copper, 

 nickel, glass and lead have a distinct adsorption odour which during 

 the first minutes or even hours has an unmistakable muscon character. 

 At last, however, a change takes place, consisting in : 



1. an alteration of the quality of the odour, so that finally it 

 resembles muse. This holds for tin, copper, nickel, glass, glazed 

 porcelain, lead alloyed with tin, lead. 



2. an increase in the smelling power of the adsorption odour, 

 so that for lead, at any rate, a maximum is obtained after about 

 3 X 24 hours. 



3. a subsequent decrease in the smelling power, so that finally 

 the tubes lose all odour. 



Free from any acquired odour the tubes become: 



