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elements, b'.it it. is claimed that it offers a better explamition for the varying 

 degrees of activity of hydrogen obtained from different sources and that 

 It also explains the activity of hydrogen absorbed in metals. 



The exi:»eriments described in this paper are designed to study the 

 activity of hydrogen from various sources as shown in its action on 

 chromic acid and chromates as well as on hydrogen peroxide and perman- 

 ganates. These were chosen because they are not the most readily re- 

 duced or because their disappearance may be easily determined by color 

 reactions. The attempt was made to study the effect of each of the sub- 

 stances which would need to be present for the reduction of the substance 

 by nascent hydrogen. In the preparation of free hydrogen for use care was 

 taken to remove any foreign material which might act as an oxidizing 

 or reducing agent. Very dilute solutions of the oxidizing agents were used 

 in order that a slight color diange might be the better noticed. The acid 

 was 30% C. P. sulphuric. Pure stick zinc was u.sed, a dozen or more being 

 I)Ouud together so that the lower end of the pile was concave, thus allow- 

 ing hydrogen to collect and work its way up between the sticlis. The results 

 with potassium dichromate solution were as follows : Purified hydrogen 

 pa.ssed into the aqueous or acidified solution caused only a very slight re- 

 duction in several hours of time. With zinc rods in the aqueous solution a 

 very slight reduction could he noticed at the end of eight hours passage of 

 the hydrogen. Nascent hydrogen generated in the solution caused a much 

 more rapid reduction of the chromate. 



Next a solution of chromium trioxide was made, the zinc rods were sus- 

 pended in the solution and especially purified hydrogen caused to pass 

 up around the bundle of rods sevei'al hours a day until the time amounted 

 to 205 liours. During tlie time the air was excluded and the space above 

 the liquid (the rods were only partly submerged) was an atmosphere of 

 hydrogen. At the end of this time the solution was still distinctly yellow 

 though slightly lighter in color than at the commencement. 



The same kind of an experiment was repeated witli potassium dichn> 

 mate but platinum foil was substituted for the zinc rods. Tii order that the 

 hydrogen might be divided into small bnbbk's and come into contact with 

 as much platinum as was possible a platinum filtering cone was sealed into 

 the end of the delivery tube and .lust al)Ove this was fastened a rosette 

 made of strips of platinum foil. The hydrogen bul)bles bumped against this 

 foil as they rose through the liquid. Connection was made so that this plat- 

 inum might be made the negative electrode for the production of nascent 



