176 COLOR PHOTOGRAPHY. 



because it reflects more of the red rays than of the rays 

 of other colors. The thing which looks green because it 

 reflects more of the green rays, etc. 



I know of no substance whatever, which does not re- 

 flect white light — black velvet even — and we may take 

 it that the rays proceedings from any object by re- 

 flection, whatever the seeming color of the object, are 

 in part composed of pure white light which dilutes and 

 brightens the preponderating ray. To be able to take 

 photographs in natural colors, that Is photographs of 

 anything we see, we must be able to do so by means of 

 the preponderating ray even in the presence of all 

 others. Hence though photographs of the spectrum 

 have (to my thinking) demonstrated the possibility of 

 making photographs in colors, it is perhaps useless to 

 pursue the subject further in that direction. 



At first sight it seems quite hopeless to expect that we 

 shall ever be able to eliminate the results of all those 

 colors which are not evident to the eye, but I hope to 

 show that it is not merely otherwise than hopeless, but 

 that it is actually easy." 



Unfortunately Mr. Wistanley died shortly after 

 making this hopeful prediction, without leaving any 

 tangible clue to the method by which he thought he had 

 found the philosopher's stone. 



His experiments so far as we ha^e any record of them 

 do not appear to open any original avenues of research. 



Dr. R. Kopp, of Munster, Switzerland, succeeded in 

 making positive prints in colors, which were sent to Dr. 

 Lesgang, but as they did not stand exposure to sunlight, 

 they were worthless, and as Dr. Kopp declined to give 

 the secret of his process, it may be suspected that the 

 prints themselves were the result of mechanical mani- 

 pulation. 



I now revert to the experiments of Mr. F. E. Ives, of 

 Philadelphia, which may be considered the most suc- 



132 



