988 The American Naturalist. . (November, 
Nagel has lately taken up the investigation’ by a. different method— 
that of simply sensing the- various compounds without fatiguing the 
organ of smell. Asa result of his investigations he concludes that 
odor-mixtures without exception follow the law of color-mixture. When 
one element of a compound extinguishes the other it is because the 
former is of far greater intensity ; but by reducing this intensity suffi- 
ciently a combination is at length reached in which the two unite to 
form a true mixture. He therefore takes exception to the earlier view, 
and believes that any two odors can be mixed in such proportions as 
to produce, at least momentarily, the sensation of a simple odor, of a 
quality distinct from the components, Whether the new odor is sensed 
as such permanently, or not, depends on the condition of the sense- 
organ; if the latter is less fatigued for some of the elements than for 
others, the former will gradually tend to predominate. The true color- 
mixture—that in which none of the elements predominate—“ resembles 
each of its components, without, however, being like them.” Thus the 
principles of odor-mixing, according to Dr. Nagel, are similar to those 
of color-mixing ; and the correspondence extends, as far as the author's 
observation goes, to the law of intensity ; the intensity ofan odor-mix- 
ture is never stronger than that of its components. The author has 
found several pairs of odors that are more or less complementary and 
produce an almost odorless mixture, though he has never succeeded in 
reaching this limit. As regards the arrangement of simple odors into 
a series, Dr. Nagel’s experiments do not tend to verify the classifica- 
tions hitherto proposed ; but he does not venture upon a classification 
of his own, since he has been unable to discover any odors which can 
be regarded as really “ elementary.”—H. C. W 
Psychology at the British Association.—At the Toronto 
meeting of the British Association, last August, a cordial invitation 
was given to psychologists to participate. There being no Psycholog- 
ical Section in the Association, the department was assigned to Section 
I (Physiology), and Dr. Kirschmann, of Toronto, was appointed a 
secretary of that Section to represent the interests of psychology in the 
arrangement of the program. 
Among the papers of special psychological bearing presented in the 
Section were the following: On visual reaction to intermittent stim- 
ulation, by Dr. Griinbaum, of Cambridge, England; on the nature 
and physical basis of pain, by Prof. L. Witmer; on the physiology of 
instinct, by Prof. Lloyd Morgan; and two on various problems of 
4‘ Zeitsch. f. Psychologie, 1897, XV, p. 82. 
