XXIII.] FROM A CHEMICAL STANDPOINT. 1*1 



Let us take the simplest course in harmony with the principle of 

 continuity, and suppose that the great number of new lines is due to 

 the breaking up of the molecules of the upper principal series given in 

 the previous table into representatives of a still finer form, as hydrogen, 

 as we know it, is broken up into a finer form at the highest stellar 

 temperatures. 



Have we, on the line of reasoning we are pursuing, any means of 

 estimating the number of finer forms which may be at work to produce 

 the 113 new lines 1 



One possible way a statistical way seems open to us. Taking 

 the number of lines already recorded in the spectra roughly between 

 A. 7000 and A 2600 of the following substances, which give us three 

 series lithium, sodium, potassium, helium, asterium, hydrogen we 

 find that the number of lines in each series and the total numbers are 

 as follows : 



Totals 39 11 24 



This indicates that in oxygen we are slightly above the average 

 with = 28 lines per set. If we take the facts for oxygen itself, 



which give us 56 lines for two sets of three, the 113 lines will give 

 almost exactly four additional sets of three series, and therefore the 

 possibility of twelve more depolymerisations if this method of simpli- 

 fication is considered. 



Of course we can halve the number of depolymerisations by assum- 

 ing that the fluting molecule instead of being depolymerised is broken 

 up into x and y, the bases of the two systems of series. 



Now it is this last crop of new lines alone which is represented in 

 the hottest stars, and no one, I think, will now urge that some kind of 

 simplification which may include depolymerisation has not taken place 

 before they were brought into evidence. 



Our base of 16 then vanishes, and with it the previously considered 

 possible atomic weights of the forms of magnesium and calcium which 

 precede the appearance of oxygen in the hottest stars. We must 

 therefore assume further depolymerisations in the case of these metals 

 beyond those considered in the first instance. 



I now come to another point. How do the above considerations 

 bear upon hydrogen with its atomic weight of 1 ? Of this hydrogen 

 we know nothing spectroscopically. There is evidence that it is broken 



