alo'ng positive ray parabolas of atoms and tnolecules of hydrogen 323 



means in strong fields tending to cause simultaneous disruption 

 of the molecule into its atomic constituents. This agrees with the 

 observed fact that in general molecular arcs, or at least true 

 primary molecular arcs, are shorter than atomic ones. It would 

 also mean that a very short arc infers as origin a molecule capable 

 of disruption. If this is so it offers interesting confirmatory 

 evidence, if such were needed, that the substance X^ is molecular 

 as this body often makes its appearance on the photographic plate 

 as a short arc. 



Effects with heavier elements. 



The inelastic collision of a hydrogen atomic positive ray with 

 the atom of a heavy element would clearly result in the formation 

 of a molecular ray of such low velocity that it might not be 

 detected by a screen or plate and would in any case be deflected 

 completely off the ordinary photograph. 



The visual evidence on the screen although faint leaves little 

 doubt that the formation of satellite arcs also takes place by 

 atoms of heavier elements colliding to form molecules. There is 

 also some evidence of this in many of the photographs, thus in 

 Fig. 26 (I.e., p. 46) taken with oxygen all four maxima are suggested. 

 In Fig. 17 (p. 26) the satellite on the molecular parabola caused 

 by the capture of oxygen atoms by carbon atomic rays (or vice 

 versa, but this is less likely) is unmistakable, in fact attention is 

 called in the text to this remarkable increase in brightness. 



Should the above theory of collision with capture prove 

 correct the formation of compound molecules by this means opens 

 an extremely interesting field of chemical research. Another 

 important question raised is in what form the energy of the 

 collision is radiated off by the rapidly rotating doublet formed. 



In conclusion the author wishes to express his indebtedness to 

 the Government Grant Committee for defraying the cost of some 

 of the apparatus used in these experiments. 



