76 INORGANIC EVOLUTION. [CHAP. 



Professors Eder and Valenta thus state the conclusions they have 

 recently arrived at in their study of the changes in the spectrum of 

 mercury : 



" Ferner ist die Erscheinung der ziemlich unvermittelten Auf- 

 blitzens des linien-reichsten Spectrums (siehe die Abbildung, Fig. 8, 

 der heliographirten Tafel) bei hochgradig gesteigerLer Starke des 

 Flaschenfunkens und gleichzeitigem Erhitzen der Capillare, beson- 

 ders das Auftauchen zahlreicher neuer Hauptlinien, welche friiher 

 nicht oder kaum sichtbar waren, und mancher Doppellinien an Stelle 

 von einfachen Linien, eine derartige, dass sie zu Lockyer's Theorie 

 der Dissociation der Elemente passen wiirde, wenn man iiberhaupt die 

 Zerlegbarkeit lingerer Elemente in die Discussion ziehen will."* 



[Translation : 



" Moreover the appearance of the great brilliancy of the richly 

 lined spectrum with a high tension jar spark, the capillary being 

 heated, and especially the interchange of a great number of new 

 lines which were dim before, and also the change of single lines into 

 double ones ; these are such that would harmonise well with 

 Lockyer's theory of dissociation of the elements, if one is prepared 

 to bring into the discussion the possibility of the dissociation of the 

 chemical elements."] 



I am glad to be able to quote the following opinion of Sir William 

 Crookes,t to which I attach great weight : 



" Until some fact is shown to be unreconcilable with Mr. Lockyer's 

 views, we consider ourselves perfectly justified in giving them our 

 provisional adhesion, as a working hypothesis to be constantly tested 

 by reference to observed phenomena." 



I am anxious to refer here also to the opinion expressed by my 

 colleague, Professor Sir William Roberts-Austen, whose researches 

 have mostly been carried on at high temperatures : 



" Mr. Lockyer has, however, since done far more : he has shown 



(3roup II). Now, as was found by Liveing and Dewar, this line exhibits just the 

 same peculiarities in the laboratory ; in the spark spectrum it is hardly recognis- 

 able, in the arc spectrum it is very strong." 



My most recent work suggests that Dr. Scheiner is wrong in identifying the 

 magnesium line 4352'IS in the cooler stars with the line nearly in the same position 

 in the hotter stars. In the hot stars the line behaves almost exactly like the enhanced 

 line of magnesium 4481'3, and I have previously pointed out that the stellar line 

 was therefore possibly not due to cool magnesium. This is now justified by the 

 discovery of an important enhanced line of iron at 4351*93, which accounts for the 

 line in the hot slars, and really strengthens Dr. Schemer's argument. 



* DenJcschrijten der Jcaiserlichen Akademie der Wissenschaften, Wien, vol. Ixi, 

 p. 429, 1894. 



f Chetn. News, 1879, vol. xxxix, p. G3. 



