134 



CHEMISTRY. 



states that he has obtained evidence leading to the con- 

 clusion that the substance giving the non-reversed line 

 in the chromosphere, which has been termed helium. 

 and not previously identified with any known form or 

 matter, and also the substance giving the 1,474 or coro- 

 nal line, are really other forms of hydrogen, the one 

 more simple than that which gives the A line alone, 

 the other more complex than that which gives the F 

 line alone. 



In closing his paper in the " Nineteenth Cen- 

 tury" Professor Lockyer thus sums up the 

 results of his investigations : 



First, the common lines visible in the spectra of dif- 

 ferent elements at high identical temperatures point 

 to a common origin. Secondly, the different lines 

 visible in the spectra of the same substance at high 

 and low temperatures indicate that at high tempera- 

 tures dissociation goes on as continuously as it is gen- 

 erally recognized to do at all lower temperatures. 



In my paper I attempt to show that it we grant that 

 the highest temperatures produce common oases in 

 other words, if the elements are really compounds all 

 the phenomena so difficult to account for on the received 

 hypothesis find a simple and sufficient explanation. 

 And, with regard to tne second count, I discuss the 

 cases of calcium, iron, lithium, and hydrogen. I might 

 have brought, and shall subsequently oring, other 

 cases forward. In all these I show that the lines most 

 strongly developed at the highest temperatures are 

 precisely those which are seen almost alone in the 

 spectra of the hottest stars, and which are most ob- 

 viously present in the spectrum of our own sun. Now, 

 if it be true that the temperature of the arc breaks up 

 the elementSj then the higher temperature of the sun 

 should do this in a still more effective manner. 



New Processes for protecting Iron Surfaces. 

 A new process for protecting iron from rust 

 has been invented by M. Dode. It consists in 

 coating, either by means of a bath or a brush, 

 any objects in cast or wrought iron (freed 

 from the damp that may adhere to them) with 

 a composition of borate of lead, oxide of cop- 

 per, and spirits of turpentine. This applica- 

 tion soon dries on the surface of the iron, and 

 the objects are then passed through a furnace, 

 heated from 500 to TOO F., according to the 

 thickness of the articles under treatment, so 

 as to bring them to a cherry-red heat when 

 passing through the center of the furnace. At 

 this point the fusion of the metallic pigment 

 takes place; it enters the pores of the iron, 

 and becomes homogeneously adherent thereto, 

 covering the objects with a dark coating, 

 which is not liable to change under the ac- 

 tion of the air, gases, alkaline or other vapors, 

 nor to scale off from the surfaces to which 

 it has been applied. "When any considerable 

 depth of " inoxidation " is desired, the object 

 may be immersed in the composition for the 

 time requisite to absorb a sufficient quantity of 

 it. This process supersedes painting and var- 

 nishing, and iron objects thus treated are im- 

 pervious to rust. The cost of application is 

 about half a cent per superficial square foot. 



A new process for coating iron surfaces with 

 magnetic oxide, for the purpose of preventing 

 rust, has recently been patented in England 

 by Mr. George Bown. The following is the 

 method of procedure: "The articles are first 

 of all heated, and acted on for a certain period 



by the products of combustion largely mixed 

 with air from a peculiarly constructed furnace 

 (designed by Mr. Anthony Bown), burning 

 slack or small coal. In this way a coating of 

 magnetic oxide is formed close to the surface 

 of the iron, but this is often slightly covered 

 with red oxide, Fe 2 3 . The admission of air 

 to the furnace is then so arranged by a suitable 

 apparatus that a stream of carbonic oxide is 

 passed over the articles for a short time, and 

 the red oxide very speedily reduced to mag- 

 netic oxide." The red oxide, first formed, is 

 easily detached from the iron, but the mag- 

 netic oxide is hard and perfectly homogeneous. 

 The coating formed by this process has been 

 thoroughly tested, and found to withstand all 

 ordinary oxidizing influences. 



The Spectrum of the Sun's Corona. Before 

 the occurrence of the solar eclipse of 1878, 

 Mr. W. T. Sampgon, U. S. N., made elaborate 

 preparations for studying minutely the co- 

 rona's spectrum, with the sole view of decid- 

 ing, by the absence or the presence in it of 

 dark lines, whether the light is reflected sun- 

 light, whether it is due to the self-luminous 

 matter of the corona, or whether it is due 

 to both of these causes combined. In the 

 "American Journal of Science and Arts" ho 

 describes the instruments used for this re- 

 search, and the manner in which they were 

 employed. His conclusion is that, inasmuch 

 as he failed to see in the corona spectrum the 

 dark lines of the sun's spectrum, therefore the 

 light of the corona is not all reflected light. 

 The following considerations confirm him in 

 this conclusion: "Until thia eclipse no ob- 

 server has ever seen the dark lines in the spec- 

 trum of the corona except M. Janssen, who 

 reported dark lines, notably D, in 1871, but 

 much more difficult to see than the bright 

 lines. Several observers during the recent 

 eclipse failed to see the dark lines, though they 

 looked for them carefully. While I do not 

 question the results of observers who report 

 the presence of dark lines, I think all the ob- 

 servations taken together show that the con- 

 tinuous spectrum of the corona is not the spec- 

 trum of the sun. Aside from this, Professor 

 Arthur W. Wright made measurements of the 

 polarization of the light of the corona (the 

 first time, I think, it has been attempted), and 

 has found the polarization to be but a small 

 percentage of the whole light emitted. Al- 

 though all reflected light does not reach us as 

 polarized light, yet I think the small percent- 

 age of polarization, taken with the faintness of 

 the dark lines, indicates that the corona is, to 

 a considerable extent, self-luminous. The me- 

 teoric dust not only reflects the sun's light, 

 but it is continually showering upon the sun, 

 and in its passage through the atmosphere is 

 rendered incandescent." 



A New Base. From a compound produced 

 by the action of dry chlorine on toluene, and 

 having the formula CmClso, Mr. Edgar F. 

 Smith has obtained a new base, the properties 



