456 WHAT IS THE SUN MADE OF? 



agency of a triangular prism. Take heed, then, of the fol- 

 lowing fact ; for upon a full comprehension of it a good deal 

 hinges. A very unimportant fact it may seem, but the phi- 

 losopher looks upon every fact, every revelation of truth, as 

 having importance. The application of it may not come to- 

 day, to-morrow not in our time perhaps, or it may be not 

 for centuries after our time, but come assuredly it will ; for 

 facts are laws, and the laws of nature are impressed by God, 

 and He does nothing in vain. 



The fact to which I would direct attention, is the exist- 

 ence of certain black transverse lines across the solar spec- 

 trum, and only across it. If some sufficiently powerful light 

 be substituted for that of the solar rays, then the particular 

 black bands now under consideration are no longer deve- 

 loped. 



It is important, moreover, to note that the black solar 

 spectral bands never vary are never altered as to their rela- 

 tive position. This fact was noted and recorded in the annals 

 of science ; for, whenever the philosopher notes a constant 

 occurrence, he treasures it. Not unfrequently such treasured 

 stores of truth are pregnant with marvellous revelations; 

 though at the time their full meaning and bearings may be 

 unknown. So much, then, for the aforesaid black spectral 

 bands. Premising that they were first remarked by Frauen- 

 hofer, and from that circumstance they have always been 

 called FrauenJwfer s bands, I will leave them for a time their 

 consideration to be resumed hereafter. 



I must now record the evidence of certain experiments 

 that will seem to be a long way removed from anything con- 

 nected with the solar spectrum. Nevertheless, their evidence 

 joined by and by to the evidence furnished by Frauen- 

 hofer's bands will hereafter reveal to us the great secret of 

 the sun's composition, in part at least. 



Did you ever see a display of artificial fireworks, wonder- 

 ing in what manner the beautiful flame-tints were produced ? 



