230 Irowbridge — Spectra of Hydrogen, etc. 



upon mere pressure and apparent temperature (temperature 

 deduced from calculations of electrical energy in electrical dis- 

 charges) as upon electrical dissociation of gases : of aqueous 

 vapor, for instance in the presence of an excess or a small supply 

 of oxygen. I believe, therefore, that any conclusion in regard 

 to temperature and pressure of hydrogen in the stars deduced 

 from laboratory experiments with electrical discharges in glass 

 vessels are misleading, since we have mainly to do with phe- 

 nomena of electrical dissociation and not of pressure and 

 apparent temperature — that is temperature which can be meas- 

 ured by calorimetric methods or which can be calculated from 

 the electrical dimensions of the circuit which is employed. 



It would seem, therefore, that the study of electrical disso- 

 ciation is necessary for the solution of problems relating to the 

 conditions of gases in the atmosphere of the sun and in that of 

 the stars. This seems to be a logical necessity, since the electro- 

 magnetic theory is far reaching and sensible heat is only one 

 of the manifestations of electrical energy. 



My conclusions are as follows : — ■ 



1. When a condenser discharge is sent through a rarified 

 gas which is confined in a glass vessel, the gas can no longer 

 be considered in the dry state : for aqueous vapor is liberated 

 from the glass. When a sufficiently powerful condenser dis- 

 charge is employed, dry hydrogen, dry nitrogen and rarified 

 air give substantially the same characteristic spectrum. When 

 a very powerful steady battery current is used to excite the 

 tubes filled with these gases — various compounds of nitrogen 

 and oxygen — nitrogen and hydrogen are formed if aluminum 

 electrodes are employed. 



2. The four-line spectrum of hydrogen in the solar atmos- 

 phere is an evidence of aqueous vapor, and therefore of oxygen 

 in the sun. 



3. Conclusions in regard to the temperature of the stars 

 exhibiting hydrogen spectra are misleading, if based upon con- 

 ditions of pressure and temperature in glass vessels; for condi- 

 tions of electrical dissociation of aqueous vapor, for instance, 

 the presence of an excess or lack of supply of oxygen, are 

 the controling ones rather than conditions of the mere pressure 

 of the gases. 



4. X-ray phenomena produced by a steady battery current 

 strongly suggest an electrical theory of the origin of the sun's 

 corona. 



Jefferson Physical Laboratory, Harvard University. 



