655 
The adsorptions of the third sort manifest themselves, when emanation 
is adsorbed to objects that may be considered as having a negative 
electrical charge, and they can be brought forth in special experiments, 
when gases, containing gasions or condensation-droplets, are placed 
between condensator-plates. 
The adsorptions of the first sort occur everywhere in daily life. 
According to Gipss’ theorem’) all substances that lower the surface- 
tension of the fluid of which the layer is composed, attach them- 
selves to the condensation layer that covers every object. The con- 
densation layer consists mainly of water, and since all odorous sub- 
stances lower the surface-tension of water’), the adsorption of odori- 
vectors must occur in all cases. It is specially those odorous sub- 
stances that possess great surface-activity, which will be largely 
adsorbed. 
It seems that the sublayer has some influence on the composition 
of the adsorbed air-vapour-layer. It may be assumed that all sorts 
of oxidation-products and decomposition-products of the solid sub- 
layer, as well as substances that have been dissolved in it, will 
pass into the condensation-layer. On metals we may look for oxides, 
on glass for alkali, on ebonite for sulphuric acid. Quartz is also 
hygroscopic and colloid chemistry assigns a reaction to its surface. 
1 feel inclined to ascribe to these components dissolved in the con- 
densation-layer, the specific character which experience has taught 
us that belongs to the adsorption of odours by certain surfaces. 
By my method (transmission of air at the rate of 100 cubic em. 
per second through cylinders of different material with a lumen of 
0.8 cm., a measured quantity of odorivector being added to the air) 
the quantum of odorous matter in the air can be determined which 
has passed along the inner surface of the cylinders. 
To perform this we should take into account the odorimetrical 
coefficient of the olfactometer that served as source of smell, as 
well as the minimum perceptibile of the odorivector in absolute 
measure. Both are known for the cases published previously and 
from them A. Heyninx and myself have deduced the partial tension 
of the odorous gas that served as odorivector. 
T will report some of my results here: 
Pyridin was hardly adsorbed to glass though a large quantity of 
‘it was present in the air; valerianic acid, however, of which there 
was only a small amount in the transmitted air, was retained for 
1) J. WiLLarp Gisps, Thermodyn. Studien, Uebersetzt von W. OsrwarLp, Leipzig 
1892, S. 258. 
*) Acta otolaryngologica, Vol. 1, p. 54, 1918. 
, 42% 
