814 THE POPULAR SCIENCE MONTHLY. 



The first author who noticed the production of impressions of 

 color by sounds was an albino doctor of Erlangen, named Sach, 

 who in 1812 described in an inaugural thesis his own impressions 

 and those of his sister. His observation is very complete, and con- 

 tains a considerable proportion of the details which are found in 

 later works. He died at the age of twenty-eight years, and his re- 

 searches fell into oblivion. During the following years doctors 

 and oculists, like Comas, of Geneva, published isolated observa- 

 tions. 



In 1873 appeared the important observations of the brothers 

 Nussbaumer, one of whom was a student at Vienna, and the other 

 a watchmaker; both of whom had from childhood experienced 

 sensations of color when they heard certain sounds. When chil- 

 dren they observed the ringing of spoons and knives tied to the 

 ends of strings, designated the colors produced by the sounds, and 

 communicated their impressions to each other ; biit they did not 

 always agree concerning the colors of the different sounds, and 

 long disputes ensued, of which their brothers, sisters, and friends 

 could understand nothing. The student afterward published, 

 under the direction of Prof. Briihl, a detailed memoir on the .cases. 



Six years afterward, in 1879, Bleuler and Lehmann wrote their 

 memoir, the most complete one we possess. Both authors studied 

 medicine at the University of Zurich ; Bleuler writes concerning 

 the origin of this work that they were talking of chemistry, when 

 the subject of ketones coming up, Bleuler remarked that they 

 were yellow, because there was an o in the word. Thus by a curi- 

 ous illusion he attributed the colors suggested by the name of an 

 object to the object itself. His friend Lehmann, greatly astonished 

 and not understanding the answer, asked for an explanation of it. 

 This stimulated his curiosity, and they both proceeded to make 

 inquiries among their relatives and friends. They published 

 accounts of more than sixty cases. 



From that time publications multiplied, and the present period 

 is marked by investigations pursued in every direction. It now 

 appears that colored audition belongs to a family of similar phe- 

 nomena, which are sometimes grouped in one person and some- 

 times scattered. Colored audition is still the most frequent and 

 best studied phenomenon, and is the single one which we intend 

 to discuss. But a word should be said of the other forms. They 

 differ chiefly in the nature of the impressions that are associated, 

 and which serve reciprocally as excitants. Thus, in some persons, 

 not sounds but sensations of taste and odor provoke the luminous 

 impressions. These may be called colored gustation and olfaction. 

 In others, psychical phenomena, like recollections or abstract 

 notions, produce the same effect. One person sees colors in the 

 months, in the days of the week, or in the hours of the day. In 



