Februaky 25, 1916] 



SCIENCE 



271 



tween the Poles of the Electrical Machine," 

 Vol. 49, 1870. This paper describes the glow 

 produced upon the positive ball in an active 

 electrical machine and the conditions under 

 which it may be produced. The striking fact 

 that each portion of this luminous surface 

 can be regarded as due to the effect of a point 

 area on the negative ball, as proved by sharp 

 geometric shadows formed by minute obstacles 

 anywhere within the region between the con- 

 ductors, is quite new and it affords a partic- 

 ularly beautiful method of determining the 

 shape and position of the lines of force. 



"A Description of a Simple Apparatus for 

 the Production of Ozone," Vol. 4, 1872, was 

 followed by two studies of the chemical action 

 of ozone. The first of these, " On the Action 

 of Ozone upon Vulcanized Caoutchouc," Vol. 

 4, 1872, calls attention to the cause of the 

 deterioration of the insulating properties of 

 vulcanite and gives means of correcting the 

 fault. The second paper, " On the Oxidation 

 of Alcohol and Ether by Ozone," Vol. 7, 1874, 

 is an application of his ozone apparatus to the 

 chemical investigation indicated in the title. 



In the same year Professor Wright pub- 

 lished two papers on the "Zodiacal Light" 

 and a note on his observations concerning the 

 polarization of the light of Coggia's Comet, all 

 of which are contained in Vol. 8. In the first 

 of these papers the question of the polariza- 

 tion of the zodiacal light even to a fair deter- 

 mination of the ratio of polarized light to 

 unmodified light, seems to have been definitely 

 settled by the skilful use of a polariscope of 

 his own design. So, also, his second paper, on 

 the spectrirm of the zodiacal light, appears to 

 have determined once for all a discussion 

 which had occupied many observers. 



In Vols. IX. to XII., we find a series of 

 papers, five in all, of great interest on the 

 gaseous contents of meteoric irons and stones. 

 In the first of these papers he reviews the 

 knovsm results of the investigations upon the 

 occluded gases of meteoric irons, quoting Pro- 

 fessor Graham and Professor J. W. Mallett. 

 In his own investigations the material came 

 for the most part from the collection in the 

 possession of Yale University. His conclu- 



sions in this first paper were that no one of the 

 several irons which he studied gave any spec- 

 troscopic evidences of unknown elements. The 

 second paper is a brief one upon the gases 

 derived from the meteorite of February 12 of 

 this year, presented as a note preliminary to a 

 farther study. 



In Volume X., " Examination of Gases from 

 the Meteorite of February 12, 1875," Professor 

 Wright gives a thorough review of the gaseous 

 contents of this meteor. It appears to be the 

 first stony meteor thus investigated and the 

 results are of great importance; they not only 

 show the presence of gases occluded in stony 

 meteors but that they are distinguished by 

 having oxides of carbon as their characteristic 

 gases, instead of hydrogen. He points out the 

 bearing of these observations upon the pecul- 

 iar spectra of comets and as a support of the 

 meteoric theory of comets. 



In Volumes XI. and XII. Professor Wright 

 continued these important investigations, ex- 

 tending them, to a considerable number of 

 stony meteors of known origin. The earlier 

 conclusion that stony meteors are character- 

 ized by a large amount of occluded carbon 

 compounds was abimdantly verified, and the 

 last paper contains a long discussion concern- 

 ing the bearing of these observations on the 

 current theory of comets. 



This terminates the series of papers on oc- 

 cluded gases in meteorites, but it is interesting 

 to note that the mastery of the problems in- 

 volved served him in an admirable piece of 

 work five years later, published in Vol. XXI., 

 1881. The paper "On the Gaseous Sub- 

 stances contained in the Smoky Quartz of 

 Branchville, Conn.," is sufficiently defined by 

 its title, but the skill and success with which 

 the investigation was carried out and its re- 

 sults presented makes the article a model 

 worthy of careful study. 



In 1877 Professor Wright published two im- 

 portant papers, in Vols. XHI. and XIV., 

 respectively, on the deposition of metallic 

 films by the cathode discharge in exhausted 

 tubes. A clear description of the technique of 

 the process and of the physical properties of a 

 large number of metals thus treated makes the 



