r>7»'> Scientific Intelligence. 



880°-920°, y = 1-69 ; from 7O0°-730°, y = 1'68 ; and from 680°- 

 700°, y:= 1*61. Similar results were obtained with sodium vapor. 

 Since, within the limits of experimental accuracy, the ratio of the 

 specific heats for potassium and sodium vapors remains constant 

 from high temperatures down to the immediate neighborhood of 

 the boiling point, and since this ratio has approximately the value 

 1*667, which is required by theory for monatomic gases, the 

 author concludes that no polymerization takes place even down 

 to the point of liquefaction itself. This result is in complete 

 accord with the investigations of Richarz which led to the con- 

 clusion that monatomicity prevails for the alkali metals in the 

 solid state. From all of his experimental data Robitzsch calcu- 

 lates the following probable mean values for the vapors of potas- 

 sium and sodium respectively : y = 1-04 ± 0'007 and y — 1-68 ± 

 0-03. The corresponding values of the ratio of the speed of sound 

 in the metallic vapors to the speed of sound in air are given as 

 0-933 ± 0-002, and 1-233 ± 0-006, in the order named.— Ann. d. 

 JPhys., No. 10, August, 1912, p. 1027. h. s. u. 



9. Untersuchungen uber magnetische Zerlegung feiner Spek- 

 trullinien im Vakuumlichtbogen. — The Zeeman effect exhibited 

 by certain fine lines of bismuth, cadmium, thallium, and zinc has 

 been recently investigated by Ch. Wali-Mohammad. For this 

 purpose he used a modified form of Janicki lamp and an excellent 

 echelon spectroscope. The results obtained are too numerous to 

 admit of a detailed account in this place, nevertheless the general 

 conclusions deserve quotation. 



It was found that the Janicki type of oxide cathode lamp gave 

 very fine, intense satellites so that it affords an excellent source 

 for studying the Zeeman effect. A few satellites were investi- 

 gated for the first time. Some of the satellites were resolved by 

 the magnetic field into three, four, five, six, and even nine com- 

 ponents. In general, the separation was proportional to the mag- 

 netic field strength. One companion line of cadmium A. = 4800 

 gave an extraordinary type of resolution. Another satellite of this 

 principal line showed that the law of displacement changed as the 

 intensity of field was increased. The cadmium line A. = 4678 has 

 satellites which are visible in the magnetic field but which cannot 

 be seen under ordinary conditions. The bismuth line A = 4722 

 has a very complicated structure, and two of its satellites suffer a 

 magnetic displacement which is proportional to the square of the 

 field strength. Finally, the author found that the resolution of 

 sufficiently fine lines could be measured in very weak fields, such 

 as 300 gauss. — Ann. d. Phys., No. 11, September, 1912, p. 225. 



h. s. u. 



10. The Absorption Spectrum of Tellurium Vapor and the 

 Effect of High Temperature upon it. — The dependence of the 

 absorption spectrum of tellurium vapor upon temperature has 

 been investigated for the first time by E. J. Evans. The vapor 

 in question was heated in a quartz tube placed inside an electric 

 furnace, the temperature of which was determined by the aid of 



