A NEW COLOR GUIDE 



P. L. RiCKER 



Several years ago the writer was appointed on a committee 

 with Dr. W. A. Murrill and the late Dr. L. M. Underwood, by the 

 American Mycological Society (now united with the Botanical 

 Society of America) to prepare a color guide adequate to the 

 needs of botanists and mycologists. After working on it for 

 about two years the writer learned of a similar work in prepara- 

 tion by Dr. Robert Ridgway, the well-known ornithologist and 

 author of a Nomenclature of Colors (1886) which contains 186 

 colors, shades and tints. After a consultation with Dr. Ridgway, 

 and later with the other members of the committee, it was decided 

 to leave the field of color work in favor of Dr. Ridgway. The 

 writer is now glad to announce that Dr. Ridgway has been par- 

 ticularly fortunate in securing competent publishers who state 

 that the work will probably be ready in about six months. The 

 chemist of the firm is an expert in colors and has, in fact, been 

 engaged at odd times for several years in preparing for a similar 

 work. Dr. Ridgway has been at the revision of his old work 

 as his time would permit for about twenty years, and it is safe 

 to say that no similar work has ever been prepared with the same 

 degree of physical and mathematical precision. This will be 

 better luiderstood by those familiar with Michelson's inter- 

 ferometer (an instrument by which it is possible to measure the 

 wave-lengths of all light colors in millionths of a millimeter, a 

 millimeter being %5 of an inch), when it is stated that each 

 primary and secondary color in this work is a composite result- 

 ing from the measurement in wave-lengths of light of each 

 color as represented in nine standard works upon the subject, the 

 measurements being made by Prof. P. G. Nutting, of the U. S. 

 Bureau of Standards. 



The work will contain 64 plates, each with 27 blocks of color, 

 in three rows of nine blocks each, or a total of about 1,350 blocks, 

 the blocks being one-half by one inch, as in his first color work. 



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