228 Trowbridge — Spectra of Hydrogen and the 



repeated as often as desired, although the apparent resistance 

 of the tube undoubtedly is raised by a more or less perma- 

 nent occlusion of what I believe is water vapor. This experi- 

 ment strongly recalls the familiar one of the glowing of plati- 

 num under a stream of non-ignited hydrogen. The electrical 

 dissociation of the aqueous vapor evidently produces an intense 

 heat at the anticathode and the X-rays are emitted during 

 this dissociation. 



If we suppose that there are material bodies circulating 

 about the sun and charged negatively — the sun being charged 

 positively — we might conceive of a similar action of a differ- 

 ence of potential on rarified aqueous vapor, which would be 

 competent to produce a corona. 



The white spectrum of hydrogen produced by hydrogen 

 coming from palladium is in its main feature similar to that 

 obtained from electrolytic hydrogen which is passed through 

 the drying apparatus I adopted. 



There are some bands, however, which need examination to 

 determine whether they arise from impurities conveyed into 

 the tube from the pump. The palladium tube apparently 

 supplies hydrogen more or less continuously to the tube to 

 repair the loss from the process of electrical dissociation, and 

 is therefore more reliable than the form of tube which is 

 filled with hydrogen through drying apparatus which neces- 

 sarily cannot be subjected to heat, and through which rarified 

 air is conveyed with hydrogen into the spectrum tube. 



The study of the effect of powerful electrical discharges on 

 hydrogen led me to endeavor to find the lines in the star £ Puppis 

 discovered by Professor E. C. Pickering: since their approxi- 

 mate wave lengths satisfy a modification of Balmer's formula, 

 Professor Pickering; attributes them to hvdroo;en. The wave 

 lengths of these new lines are comprised in the spectral region 

 extending from about 4200 to 3700. I have plotted them as 

 short lines contiguous to the normal solar spectrum in fig. 3, 

 ISTo. Y. The long lines correspond approximately to the most 

 intense lines or bands in the spectrum of hydrogen produced 

 in the tube provided with the palladium adjunct. The hydro- 

 gen spectrum when regarded as a whole on the scale of small 

 dispersion I have employed, seems to be made up of lines 

 spaced according to a certain order, very much as if two sets 

 of lines spaced according to a certain arrangement should be 

 superposed on each other ; the fingers of one hand shifted over 

 those of the other. The hydrogen lines are more or less inten- 

 sified bands or dark accumulation of lines almost obscured by 

 the spectra produced by the compound of nitrogen and aqueous 

 vapor if a very strong battery carrent is employed in a tube 

 provided with aluminum electrodes. It is possible that certain 



