( 7J ) 



The larger values of h and their regular change are dne to the 



absence of a la^^er of carbon at the connnencemeni of the experiment. 



If we compare this table wilh the one given by Schrnck and 



ZiMMERMANN for 445° 



we notice that the very considerable change of /■ cannot l)e fully 

 explained by the absence of a layer of carbon but that there must 

 have been another disturbing factor. 



From ScHKNCK and Zimmermann's description it is evident thai it 

 cannot be the absorbed hydrogen '), for this was introduced iut(» 

 their apparatus only in the /zV.V(( scries of experiments and the second 

 series shows a still greater change. 



For want of fui-ther j)arliculars as to the research of ScinwcK and 

 ZiMMERMANN we cauuot make any fiii-dier suggestions as to the nature 

 of this second disturbing factor. 



1) We found tliat H^i is very strongly absorl)od hy fmely divided Ni l)uf gradually 

 expelled in vacuum Aceording to S.\batii:r and Sendeuf.ns [G.r. 134 p. 51i--510 

 (1902)] CO and H. read with eaeli oilier above 200' in contact with finely 

 divided nickel accoi'ding the equation: (JO -h 3 Ho = Cllt + ILO, 



