947 
The charges of sprayed equimolecular solutions can be readily 
compared. The two highest terms, however, are so little soluble, 
that the first term would not yield a charge in that extreme dilution. 
For this reason only groups should be examined in which the first 
three terms can indeed be taken equimolecular 
| . . Electrical charge 
Conc. Optimal distance _ in coulombs per c.c. 
1 
Benzol vann normal 30 cm. | 18.9 X 10—!1 
1200 | x 
1 | 
Toluol 1200 5 | 5 hes 18.9 XxX 10-11 
1 
Xylol 1200 5 43 4, | 28.7 10—!! 
| 
Pseudocumol ds a 35 4 | 18.4 DX 10—!! 
Durol a ” | 35 ” 18.0 XX 10-1! 
| 
It will be seen that on further methylation the electrical charges 
of an equimolecular ‘solution rise slowly at first, later on very 
rapidly. Parallel to this runs a progressive insolubility in water. 
Adsorptivity. 
The capacity of the terms of the methyl-benzol series of being 
adsorbed to charged or uncharged metallic plates is remarkably 
slight. Benzol is the only one fhat adheres to the metal wall in 
some measure, the other substances not at all. 
Olfactometry (at the stimulus-threshold). 
The olfactory values appeared to be the following: 
Benzol 0.3 em. corresponding to the liminal 
Toluol O60. te values in gram-molecules found 
Xylol 0.7 ,,. {in a previous experiment (sti- 
Pseudocumol 0.8 ,,. | mulus-threshold). 
The olfactometrical coefficients may readily be computed from 
them. They are for benzol 3.3; for toluol 2.0; for xylol 1,4 and 
for pseudocumol 1.3. 
These liminal values vary distinctly as the series advances. Each 
