Chemistry and Physics. 245 



C, 3 H„ j O„KI-2H ) 



c„h;,o„l.ci-2H 2 o 



C lt H M <VLiBr-2H,0 



C„H ! ,0 1 ,LiI-2H,0 



C 1 ,H M O lI CaBr,-3H,0 



C 1! H 22 11 -CaI 8 -3H J 

 2C„H„0 11 BaCJ 1 

 2C la H M O n BaBr, 

 2C„H M O n BaI, 



It is proposed to study the properties of these bodies in the 

 future, and also to attempt the preparation of compounds with 

 other salts. — Comptes Rendus, cxxxvii, 1259. h. l. w. 



6. The Density of Chlorine. — New determinations of the 

 density of chlorine gas have been made by Moissax and Jassonetx. 

 The method of Dumas was employed, which consists in rilling a 

 globe having a slender neck with the gas, by displacement, seal- 

 ing the neck by fusion, and weighing. Considerable difficulty 

 was experienced in obtaining pure chlorine ; even liquid chlorine 

 was found to hold other gases in solution, and the best results 

 appear to have been obtained by using chlorine which had been 

 previously solidified by cooling. As an average of the best 

 results, the density 2*490 at 0° is given. This number agrees 

 very closely with Leduc's result, 2*491, published in 1897. — 



Comptes Rendus, cxxxvi, 1198. h. l. w. 



7. The Doppler Effect in Electrical Sparks. — If metallic par- 

 ticles are torn off from the electrodes between which a spark is 

 produced and are lighted, one would expect on looking in the 

 direction of the spark with a suitable optical arrangement to see, 

 according to Doppler's principle, a displacement of the lines of 

 the spectrum. Aug. Hagenbach uses two sparks in front of the 

 slit of a spectroscope. The current was directed through these 

 gaps in opposite directions. In one experiment Michelson's eche- 

 lon spectroscope was used with mercury lines. The results were 

 negative ; and the author concludes that there is no displace- 

 ments greater than O'Ol A. -unit ; if the Doppler principle holds 

 for the case of electric sparks, the velocity of the metallic particles 

 cannot be greater than this value indicates. In another experi- 

 ment a Rowland grating w T as used and a similar result was 

 reached. The author's results do not agree with those obtained by 

 Schuster and Hemsalech, or with those of Mohler, in regard to 

 the velocity of the shot off particles. These authors found a 

 large velocitv for such particles. — Ann der Physik, xiii, pp. 

 362-374. j. t. 



8. Effect of Temperature on Ionization by Rontgen Rays. — 

 R. K. McClung, working in the Cavendish laboratory, believes 

 that he has proved conclusively that, in a given volume of gas, 

 kept at a constant density, the amount of ionization produced by 

 Rontgen rays of a given intensity is independent of the tempera- 

 ture of the gas. — Phil. Mag., 1904, pp. 81-95. j. t. 



