The oxidases and other oxygen - catalysts concerned in biological oxidations / by J. H. Kastle.

  • Kastle, Joseph H. (Joseph Hoeing), 1864-1916.
Date:
[1910]
Catalogue details

Licence: In copyright

Credit: The oxidases and other oxygen - catalysts concerned in biological oxidations / by J. H. Kastle. Source: Wellcome Collection.

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    responsible for the phenomena observed. It has been observed by these and other investigators that when a jet of steam emerges from a small orifice into dust-free air, there is very little if any condensation to be observed within half an inch or so of the orifice. On the other hand, if an electrode from which electricity is escaping be placed near the origin of the jet, dense condensation occurs right up to the orifice, and the jet itself appears colored, the color being due to the scattering of light by a great number of very small particles of water, the diame- ter of which is very small compared with the wave length of light. According to J. J. Thomson (422), the electricity which escapes into the gas is carried by the charged atoms of the gas, and since in the region immediately around these atoms there will be a very intense electric field there will be a tendency for the steam to deposit in these regions. Thus around these charged atoms there will be very small drops of water, which mil scatter the blue light more than the red, so that the jet when seen by transmitted light will appear reddish. Von Helmholtz and Richarz (208) found further that condensation in the steam jet is also brought about by chemical action going on in its neighborhood. The reactions investigated were of the most varied character, involving such processes as the combination of nitric oxide and oxygen, ammonia, and hydrochloric acid, the oxidation of phosphorus, sulphur, and other readily combustible substances. All of these were found not only to effect the condensation of live steam, but also to cause the condensation of other vapors, such as those of alcohol and acetic acid. As a matter of fact so univer- sal is this influence that Von Helmholtz and Richarz proposed to employ the steam jet as a means of detecting ionic dissociation in gases. Thus Von Helmholtz (207) found that condensation is effected in the steam jet by various glowing metals, such as platinum foil which had been heated to redness and which had not been artificially electrified. Similarly other metals such as silver, iron, copper, etc., after heating in the flame, color the steam jet for a long time. This is also shown in a high degree by all glowing organic bodies, such as wood, paper, tobacco, and especially by glowing sulphur. It was also proved that the production of smoke has nothing to do with the phe- nomenon observed. Tobacco smoke, especially, was observed to be without influence. Von Helmholtz and Richarz (208) found that con- densation in the steam jet could be brought about by a piece of glow- ing phosphorus at a distance of several decimeters away, and that at this distance it acted remarkably powerfully, but less actively, on the vapors of alcohol, anilin, formic, and acetic acids. They also proved that the thick white clouds which are produced when moist phosphorus is exposed to the air or oxygen do not exhibit this phenomenon when the glowing phosphorus is quenched. So, also, the oxidation products of phosphorus already prepared had no influence on the condensation.