( 90 ) 
Physiology. — "About Odour-affinity , based cm experiments of 
J. Hermabides. By Prof. H. Zwaardemaker. 
(Communicated in the meeting of May 29, 1909). 
In the physiological laboratory at Utrecht Mr. Hermanides prepares 
a dissertation about the constants of olfactometers used in qualitative 
measurement of odour 1 ). The latter are nine in number. The 
odorous matter consists as much as possible of pure substances, 
taken up by parafiinum liquidum, with the exception of muscon, 
which is divided in myristine-acid. In the measurements first of 
all the weakest observable stimulus is fixed for each olfactometer 
separately. In order to compare the results that Mr. Hermanides 
arrived at, with those of other observers we give in the subjoined 
table a review of minimum values of stimuli. Each figure represents 
the mean out of 10 observations. 
MINIMA PERCEPTIBILIA 
z, 
Z 3 
N 
K 
H S 
fv. d. H. L. 
1 abnormal 
odour-syst*) 
Ha 
Isoamylacetate r/,% 
0.23 
0.2 
0.3 
0.245 
0.3 
0.34 
0.4 
Nltrobenzol 5% . 
0.03 
0.03 
0.03 
0.02 
0.02 
0.007 
0.03 
Terpineol 2.5%. . 
1.10 
1.10 
2.0 
2.90 
1.3 
>7.00 
1.2 
Muscon 0.627%. . 
0.15 
0.15 
0.3 
0.2 
1.45 
0.3 
Aethylbisulfidel°/ c00 
0.015 
0.015 
0.005 
0.004 
0.012 
0.28 
0.02 
Guajacol l°l m . . . 
0.30 
0.30 
0.25 
0.50 
0.5 
2.30 
0.6 
Valerian acid l%oo 
0.03 
0.03 
0.02 
0.02 
0.04 
0.05 
0.04 
Pyridine l»/«. ., . 
0.02 
0.02 
0 02 
0.023 
0.03 
2.25 
0.03 
Skatol 10/qo. .... 
0.002 
0.003 
0.0003 
0.002 
0.000043 
0.003 
The names of the observers whose initials are given at the head 
of the columns, are: Zwaardemaker, Noyons, Kubo, Hermanides, van 
der Hoeven Leonhard, Heringa. The mean error in the observations 
of Mr. Hermanides was very satisfactory, viz.: 
J ) See Meeting 28 Sept. 1907. 
2 ) At the same time abnormal trichromate, as to sense of colour; compare 
Onderz. Physiol. Lab. Utrecht (5), Deel. 8, p. 394. 
