THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



SEPTEMBER 1878. 



XXIII. Recent Researches in Solar Chemistry. 

 By J. N. Lockyer, F.R.S.* 



THE work which is now being done in the various new 

 fields opened up in connexion with solar studies may be 

 conveniently divided into three perfectly distinct branches. 

 We have, first, that extremely important branch which has for 

 its result the complete determination of the position of every 

 thing which happens on the Sun. This, of course, includes a 

 complete cataloguing of the spots on the sun which have been 

 observed time out of mind, and also of those solar promi- 

 nences the means of observing which have not been so long 

 within our reach. It is of the highest importance that these 

 data should be accumulated, more especially because it has 

 been determined that both in the case of spots and promi- 

 nences there are distinct cycles, which may in the future be 

 very much fuller of meaning to us than they seem to be at 

 present. 



This brings me to refer to the second branch of the work ; 

 and it is this : — These various cycles of the spots and promi- 

 nences have long occupied the attention both of meteorologists 

 and magneticians ; and one of the most interesting fields of 

 modern inquiry, a field in which very considerable activity has 

 been displayed in the last few years, is one which seeks to connect 

 these various indications of changes in the sun with changes in 

 our own atmosphere. The sun, of course, is the only variable that 



* Communicated by the Physical Society, May 11, 1878. 

 Phil Mag. S. 5. Vol. 6. No. 3G. Sept. 1878. ' M 



