555 
c. in the case of change of solubility and surface-tension through 
combining with salt- or sugar-soiutions. 
Divergencies are seen on either side. Some strong-smelling scents, 
moschus and seatol, set up a sensation even in dilutions, the elec- 
trifying power being next to none. With antipyretica on the con- 
trary, the smell-intensity is all but inappreciable, the electrifying 
power very considerable. For an interpretation we must, in the 
present stage of our research, look to the five conditions, just men- 
tioned, upon the fulfilment of which the properties depend. Maybe 
the study of the dielectric-constant will throw some more light on 
the subject in connection with A. Corun’s theory of contact-electri- 
city, according to which the difference of potential, in the case of 
mutual contact of two substances is proportional to the difference 
of the dielectric constants '). The differences between the dielectric- 
constants of odorous substances and those of water are generally 
very great, so that likewise we may look for great charges on 
numberless droplets, when odorous molecules accumulate on their 
surfaces in virtue of the fall of the surface-tension. The rapid 
evaporation from the measureless area makes these differences all 
the more probable, especially when a slight rise of the temperature 
increases the evaporation and the sprayer is placed at the proper 
distance from the intercepting screen. 
Chemistry. -— “The equilibrium solid-liquid-gas in binary systems 
which present mixed crystals”. (Fourth communication). By 
Prof. H. R. Krvuyr. (Communicated by Prof. Ernst COHEN). 
(Communicated in the meeting of September 30, 1916.) 
1. In the former communication?) has been communicated a 
research of Dr. W. D. Hetperman and myself on the three-phase 
equilibrium solid-liquid-gas (SLG) in the system bromine-iodine. 
The three-phase line exhibited in its PT-projection two maxima 
and one minimum, a peculiarity which is closely connected with 
the appearance of the compound IBr. For the general knowledge 
of the binary systems it is not uninteresting to more closely con- 
sider these equilibria; all the more so because the appearance of 
two maxima and one minimum on the melting branch of a com- 
1) A. GosHn u. U, Raypr. Göttinger Nachrichte 1909 p. 263. 
2) Proc. Royal Ac. A’dam, Meeting of June 1916. 
