on the Nets} Analysis of Solar Light. 157 



division of the spectrum into seven colours, and their difference 

 of refrangibility, is not in the slightest degree affected by the 

 results of my analysis. "And where," he continues, "are 

 we to find such light since the atmosphere absorbs ?" I awain 

 answer, that Newton's prismatic analysis must, of course, be 

 the analysis of light after it has experienced all the actions 

 which it has undergone in passing through the atmospheres of 

 the sun and the earth ; but if I misapprehend the object of the 

 (]uestion, it may be otherwise answered by stating that lio-ht 

 which has not suffered absorption, and which does not want a 

 single definite ray, may be found in the white artificial flames 

 with which we are all familiar. I have distinctly stated in my 

 original memoir, what Dr. Whewell seems not to have read, 

 that Newton's analysis of light by the prism is perfect, so far 

 as it goes; but Newton committed a mistake, if mistake is the 

 proper term, when he asserted that to the same refrangibility 

 always belongs the same colour. 



Having authorized Dr. Whewell to refer again to his ex- 

 periments on absorption, the Astronomer Royal has thought it 

 necessary, in order to justify the reference, to publish hhrecollec- 

 tions of these experiments. This isthefirst time in the annals of 

 science that the recollections of experiments have been given 

 to the world. A philosopher in his decline, when his failino- 

 .sight and his trembling hand are no longer fit for the delicate 

 operations of experimental inquiry, may be excused for callin"' 

 up the recollections of his manhood in support or in refuta- 

 tion of some exciting speculation ; but no apology can be made 

 for those who, with the means and the leisure for repeating 

 their experiments, bring forward their recollections to discre- 

 dit or to overturn the researches of others who have laboured 

 patiently and successfully in the same field of scientific re- 

 search. 



In the present case these recollections have a still more 

 peculiar character: they are admitted by their author to be 

 " 07U1J negative" " Of the results of these experiments," says 

 the Astronomer Royal, " / can give little more than the single 

 negative one, — that no change was produced in the qualities of 

 the colours." These recollections have still another peculiarity. 

 Relating as they do to colours, they are the recollections of a 

 person who confesses that he has no memory for colours, and 

 so imperfect are they that he forgets the names of the miscel- 

 laneous contents of a chemist's shop through which he viewed 

 the spectrum, and he remembers only the "port and porter" 

 of his own cellar. Mr. Airy cannot even tell us what he ac- 

 tually saw when he absorbed the sun's rays by smalt-blue glass, 

 port and porter. He does not describe the spectrum thus 



