﻿Chemistry and Physics. 159 1 



observers in comets B and C, 1881,* and by Secchif in comet 

 1111, 1874. In carbon spectra and comet spectra also bands in 

 the violet and ultra violet 414-420, 385-389, are photographed. 

 The comparison of this spectrum with the low temperature 

 spectrum of carbo-hydrogen^: is not without interest. The 

 distance of the comet from the sun was greater than 1*5. It 

 may perhaps be suggested that the difference between this 

 spectrum and that usually observed is due to temperature. 

 It would be well if we had for the carbon compounds, a chart 

 at successive heat levels, after the manner of that drawn up 

 by Lockyerg for the photographed spectra of some carbon 

 compounds. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the Combustion of Carbon monoxide and Oxygen. — 

 Lothae Meter has repeated the experiments of Dixon upon the 

 non-inflammability of a perfectly dry mixture of carbon monoxide 

 and oxygen, by means of the electric spark. The monoxide was 

 prepared from magnesium formate and sulphuric acid and was 

 shown by analysis to be pure. It was mixed with pure oxygen 

 and in the first experiment was carefully dried for twenty-four 

 hours with phosphoric oxide in the eudiometer. The ordinary 

 spark of an induction coil failed to ignite the mixture ; but using 

 the primary coil of a moderately large inductorium with four 

 large bichromate cells, ignition took place at 443 mm pressure. In 

 the second experiment, the drying was continued for the same 

 time. The mixture ignited by the spark under a pressure of 

 275 mm , but the explosion was incomplete ; on increasing this 

 pressure to 427 mm a second explosion took place, all the CO 

 being burned. In the third experiment, the gas mixture was 

 dried for six days and the sparks were continued for two minutes 

 under a pressure of 156 mm . The combustion was complete. 

 Meyer concludes therefore that carbon monoxide is not abso- 

 lutely uninflammable under these conditions, but only difficultly 

 inflammable. Moreover, since Dixon had observed an incomplete 

 union with a series of sparks and a complete one when an ignited 

 platinum wire was placed in the gaseous mixture, the author is of 

 opinion that Dixon's results as well as his own are in accordance, 

 and are all to be explained simply by difference of temperature 

 in the spark ; reduction of C0 2 to CO and O taking place when 

 the spark is feeble, and oxidation of CO to C0 2 when it is strong. 



* Monthly Notices Roy. Astr. Soc, Nov. 1881, p. 15. 

 f Memorie dei Spectroscopiste Ital, voi lii, 1874, p. 118. 

 % Micrometric Gaseous Spectra. Piazzi Smyth. 

 § Proceedings Royal Society, vol. xxx, p. 463. 



