236 Scientific Intelligence. 



companied by violent and persistent catarrh of the eyes and 

 mucous membrane. The specific gravity of this new sulphide is 

 T2739. When heated it polymerizes into a hard black substance, 

 having the same composition. It can be partially distilled in 

 vacuo at 60°, but even then a small portion polymerizes. In a 

 few weeks, the liquid spontaneously changes into the black form. 

 This form is soluble in caustic alkalies and is reprecipitated un- 

 changed by acids. On heating it yields an inflammable gas con- 

 taining sulphur which is not carbon disulphide. — Ber. JBerl. Chem. 

 Ges., xxvi, 2960, January, 1894. g. f. b. 



9. Emission of Gases. — F. Paschen shows that previous ob- 

 servers have neglected to take into account a marked absorption 

 effect of C0 2 . He finds that a 7 cm thick layer of this gas absorbs 

 all the light of the wave-length of the main absorption band. 

 The amount of CO„ and H„0 in a 83 ctn thick layer of the air of a 

 room is sufficient to produce sharp absorption bands. This 

 phenomenon is the source of error in Angstrom's determination 

 of the absorption of C0 2 , and apparently also in Rubens and 

 Snow's determination of the dispersion curve of fluor spar, and in 

 their research upon the dependence of the emission of a solid body 

 upon the temperature. A comparison of Paschen's results with 

 those of Angstrom, shows that the absorption coefficient of the 

 latter must be doubled. C0 2 shows no absorption in the portion 

 of the spectrum in which its absorption bands do not lie. 

 Oxygen and nitrogen in layers a decimeter thick and under 

 atmospheric pressure show no absorption bands. — Ann. der 

 Physik und Chemie, pp. 1-39, No. 1, 1894. j. t. 



10. Apparatus for studying and showing electrical resonance. — 

 A. Righi has succeeded in obtaining electrical waves of 7 - 5 cm in 

 length. His oscillator consists of two straight brass cylinders 

 which are terminated at both ends with spheres 4 0m in diameter. 

 The entire length of the exciter with the bulb is 62 cm . Upon this 

 two circular copper discs of 34 - 5 diameter can be adjusted. They 

 are generally placed 43 cm distant from each other. Both middle 

 spheres between which spring sparks of from 2 to 5 mm length, 

 are placed in a glass vessel filled with a thick mixture of vase- 

 linol and vaseline. Opposite to the two outer spheres stand two 

 other spheres which are connected with the poles of an electrical 

 machine, from which the Leyden jars are removed. The resona- 

 tor consists of a circle of copper wire of 57 cra in diameter closed 

 by a small Geissler tube which was selected out of a large num- 

 ber, and was so sensitive that it lighted at a distance of 6 m from 

 the exciter and so brilliantly that the interferences between elec- 

 trical waves, propagation of these waves along wires, and allied 

 phenomena could be shown to an audience. For very short 

 waves, the exciter consisted of four brass spheres r36 cm in diam- 

 eter which were placed over each other. The upper and under 

 were connected with the electrical machine, the two middle 

 ones, capable of adjustment, were mounted in a vessel filled with 

 a mixture of vaselinol and vaseline. The resonators consisted of 



