554 
is a different matter. Take e.g. acetic acid and anilin, both of a 
rather high electrifying power; when they are combined to acet- 
anilid (antifebrin) we get an odourless substance. Will it have 
electrifying power? To this question no a priori answer can be 
given, for the compound molecule as a whole and not the com- 
ponents from which it is derived, is answerable for the electrical 
phenomenon. Such a molecule, if electrifying at all, should satisfy 
the following conditions: 
1. it should be soluble in water (substances insoluble in water 
do not give a charge). 
2. it should lower the surface-tension of water, i.e. if a solid, 
it should yield the camphor-phenomenon. 
3. it should volatilise from the aqueous solution, when spread 
over a large evaporation area. 
The first and third conditions are fulfilled by acetanilid; experi- 
ments also show that it belongs to the remarkable group of organic 
substances, which like odorous substances produce the electrical 
phenomenon. 
The three conditions just mentioned must be fulfilled in order to 
bring about an electrical phenomenon. Such substances may be 
odorous and will be so when moreover: 
+. the substance is soluble in lipoid (a// odorous substances are 
soluble in oii). 
>. an odoriphore is present in the molecule. 
The fourth condition is not or hardly satisfied by acetanilid; as 
to the fifth two groups of atoms are present in acetanilid that 
may be taken for odoriphores: 1. the aliphatic acid, 2. the ani- 
lin group. 
Rure and y. Mavsewski') hold, however, that, when in one and 
the same molecule there are two odoriphores, a mutual counteraction 
may occur. This’ hypothesis and the slight solubility in oil account 
for the inodorousness of acetanilid. The same holds for other anti- 
pyretica (phenacetin, antipyrin, quinine). It is to be regretted that 
exceptions to such rules are never wanting. 
All this leaves us still in the dark concerning the mysterious 
paralellism between smell, as a physiological, and vapour-electricity, 
as a physical property. This paralellism has thus far manifested 
itself for the vast majority of odorous substances: 
a. in homologous series, 
b. in the case of successive dilutions, 
1) K. v. Majewski, Beitr. z. Kenntn. d. Diazo-imido-benzolderviate. Inaug. Diss. 
Basel 1898. 
