January 15, 1904.] 



SCIENCE. 



95 



b ' ( coroniimi and helium) . Ames,* having 

 called attention to the use of uncorrected 

 data by Griinwald, remarks: 'The concave 

 grating gives the only accurate method of 

 determining the ultra-violet wave-lengths of 

 the elements; and as a consequence of not 

 using it, most of the tables of wave-lengths 

 so far published are not of much value.' 



Hutchins and Holden,t after a compara- 

 tive study of the are spectra of metals and 

 the sun with a twenty-one-foot focal Row- 

 land grating, state: "We are convinced that 

 there is much in the whole matter of coin- 

 cidences of metallic and solar lines that 

 needs reexamination; that something more 

 than the mere coincidence of two or three 

 lines out of many is necessary to establish 

 even the probability of the pi'esence of a 

 metal in the sun. With the best instru- 

 ments the violet portion of the solar spec- 

 trum is found to be so thickly set with fine 

 lines that, if a metallic line were projected 

 upon it at random, in many places the 

 chances for a coincidence would be even, 

 and coincidences could not fail to occur in 

 case of such metals as cerium and vana- 

 dium, which give hundreds of lines in the 

 arc. ' ' 



"Moreover, a high dispersion shows that 

 very few lines of metals are simple and 

 short, but, on the contrary, Avinged and 

 nebulous, and complicated by a great va- 

 riety of reversal phenomena. A 'line' is 

 sometimes half an inch wide on the photo- 

 graphic plate, or it may be split into ten 

 by reversals." 



Lockyer maintained that the lines of cer- 

 tain brilliant substances vary not only in 

 length and in number, but also in bril- 

 liancy and in breadth, depending upon 

 the quantity of the substance as well as 



*Am. Ghem. J., 11, 138, 1889. 



t ' On the Existence of Certain Elements, To- 

 gether with the Discovery of Platinum, in the 

 Sun,' Am. Jour. Sei.; 8ci. Am. Supp., 25, 628, 



temperature.* Being unable to decompose 

 the elements in the laboratory, he studied 

 the spectra of the stars. The spectra of 

 the colder stars f show many more metals, 

 but no metalloids, whereas the coldest 

 stars, A. Orionis, show the Crookes spec- 

 trum of metalloids Avhich are compounds. 

 None of the metalloids are found in the 

 spectrum of the sun. Over 100,000 visual 

 observations and 2,000 photographs were 

 made in the researches. 



Liveing,! as the result of the Avork of 

 Young, DcAvar, Fievez and himself on the 

 spectrum of the sun, by which some lines 

 were resolved with a new instrument, 

 which they before had not been able to 

 devise, comments on Lockyer 's Avork : That 

 the coincidence of raj^s emitted by differ- 

 ent chemical elements, especially Avhen de- 

 veloped in the spark of a poAverful induc- 

 tion coil, and the high temperature of the 

 sun and stars, gives evidence of a common 

 element in the composition of the metals 

 Avhich produce the coincident rays. "This 

 result can not fail to shake our belief, if 

 Ave had any, in the existence of any com- 

 mon constituent in the chemical elements, 

 but it does not touch the evidence Avhich 

 the spectroscope affords us that many of 

 our elements, in the state in Avhich -Ave know 

 them, may have a very complex molecular 

 structure. ' ' 



Hartley§ in his recent admirable address 

 said: 



'■ I have always experienced great difficulty in 

 accepting the view that because the spectrum of 

 an element contained a line or lines in it which 

 were coincident Avith a line or lines in another 

 element, it M'as evidence of the dissociation of the 

 elements into simpler forms of matter. In my 

 opinion, evidence of the compound nature of the 



* Koij. Soc. Proc, 61, 148, 183; Chein. Neics, 79, 

 145. 



t Chem. 'News, 79, 147. 



% Address before the Chemical Section of the 

 British Association, Scientific American Supple- 

 ment, 14, 356, 1882. 



§ JjOC. cit. 



