374 THE CHEMISTRY OF THE SUN. [CHAP. 



instance, where Angstrom gives no line as common to two 

 substances, yet Thaleii does. We find that both are right ; that 

 at the temperature of the electric arc that line does not appear 

 in one substance or the other, while at the temperature both of 

 the quantity and the intensity induction coils the line is certainly 

 there. In Fig. 119 A represents Angstrom's work, T Thalen's, and 

 L Q and L I my own. work with the quantity and intensity coil. 



What then is the final result ? It is this ; almost every im- 

 portant line in the spots, every important line in the storms, 

 has been picked up by this method, and in fact the map of basic 

 lines along this region is practically a map of the lines widened 

 in spots and present in storms, and nothing else. Now it may be 

 said that result is interesting, and perhaps important, but that 

 it deals only with a very limited part of the inquiry. That is 

 perfectly true. 



The spectrum of iron and the spectra of other substances 

 have however been attacked in other regions. It is unnecessary 

 to go into more details here, but the general result may be 

 expressed in rather a different way, and it will then be easy to 

 see the extraordinary parallelism which goes on between two 

 perfectly distinct sets of facts ; first, the statement that such and 

 such a line is seen in the spectra of two or more substances, 

 and then the other statement that such and such a line is seen 

 widened in spots or brightened in flames. I give below the 

 numbers for the two regions which I have already discussed, the 

 region from F to b, and from b towards D, in the case of the 

 three metals iron, nickel, and calcium. 



Iron. 



F-b J-548 



Total number of lines 96 . 67 



Number in spots and prominences .... 38 . 41 



Basic lines . . . . . .... . . . . . 15 . 17 



seen in spots and prominences . . 14 . 15 



'-'-. - '.-- . -"'- -not -seen- ---,; :1 ,, - -; ;-"- 1 .. ' 2 - 



