General and physical chemistry
Journal of the Chemical Society Abstracts
By means of a micro-radiometer the authors have measured the reflective power of ethyl alcohol for ultra-red radiation. In order to avoid errors resulting from the absorption of the radiation in the vapour above the liquid, this was coded to a temperature of about -20. The experimental data indicate the existence of selective reflection, this being more pronounced than in similar experiments a t 18'. The maxima on the curve representing the reflective power as a function of the wave-length are
... he wave-length are all found to be displaced towards the visible spectrum by a lowering of the temperature from 18' to -2 O O . Whether this is due to the diminution in the absorption of the alcohol vapour in contact with the liquid has not been established. H. M. D. Refraction and Dispersion of Krypton and Xenon and their Relation to those of Helium and Argon. CLIVE CUTHBERTSON and M. CUTHBERTSON (Yroc. Roy. Xoc., 1908, A, 81, 440--448).-The measurements were made by a method previously described (Cuthbertson and Metcalfe, Abstr., 1908, ii, 545). The values of ( p -1).1OG for the green mercury line (h=5461) are for krypton and neon respectively 428.74 and 705.49. The dispersion for krypton is given by the formula p -1 = 0.0004189(1+ 6*97/h2. loll), and that for xenon by p -1 = 0.0006823(1+ 10*14/h2.1011), both gases being at normal temperature and pressure. When the refractivities for infinite wave-lengths of helium, neon, argon, krypton, and xenon are compared, the numbers are found to be very nearly in the ratio 1 : 2 : 8 : 12 : 20. If the values of b in the equation p -1 = a(1 + b/X2) are plotted against the refractivities for infinike wave-lengths, a straight line can be drawn through the points representing helium, krypton, and xenon ; the corresponding point for argon is also quite close. On the other hand, mercury does not fall into line with the other four monatomic elements in respect of the relationship between refractive and dispersive power.