No. I.] THE VERTEBRATE EAR. 299 



cessively sensations of sweet, sour, bitter, at a rate correspond- 

 ing with the length of the section of each taste in the tube and 

 the rapidity of the flow. By increasing the rapidity of the flow, 

 the sensations become less distinct and finally blend into a 

 mixed sensation of bitter sweet, sweet sour, or any of the other 

 possible combinations of these flavors, depending upon the rela- 

 tive predominence of any single one of the liquids. But the 

 nerves of taste do not analyze this compound sensation. It is 

 analyzed in the brain, but even there only on the basis of edu- 

 cation as to what constitutes the peculiarities of the sweet, sour, 

 and bitter taste used. 



The same character of experiment may be tried, with about 

 the same results, in the case of the nose, except gases are 

 preferable to liquids. 



Or, again, the sense of touch may be experimented upon in a 

 similar manner by causing an endless rod whose succeeding sec- 

 tions of a few millimetres in length are alternately cool and 

 warm, to pass over any temperature-sensitive surface of the body. 

 The sequence of varying temperatures may have any arrangement 

 desired, and the result is not essentially altered. The sensa- 

 tions, when following each other with a rate sufficiently slow, 

 are transmitted individually to the brain by the same nerves ; 

 but when the rate is increased beyond a certain limit, they be- 

 come more or less blended into a single temperature sensation. 

 There is no analysis of the sensations here either in the end 

 organ or in the brain, unless previous experience enables the 

 person to determine, on general grounds, that the sensation is 

 produced by a sequence of stimuli of varying temperatures. 

 Again, the eye and the brain fail to analyze the sensation due 

 to a rapid succession of colors into the component colors. And 

 yet a mental analysis is possible on the basis of previous experi- 

 ence and education in the composition of colors. 



After explaining at length his view that the quality of a tone 

 is due to the forvi of the sound wave (Joe. eit. Chap. I, "Form 

 of Sound Wave "), Helmholtz comes to the consideration of 

 "Apprehension of Qualities of Tone," Chap. VI, p. 119, and 

 concludes from a series of experiments that "the quality of the 

 musical portion of a compound tone depends solely on the num- 

 ber and relative strength of its partial simple tones, and in no 

 respect on their differences of phase." Or, in other words, the 



