XATURE 



[May 2, 1895 



On thk N'kw tiAs obtaixkd from Ura.nimte.' 



On March 2S, Prof. Ramsay was so good as to send nic a 

 nibe containing a new gas obtainc<l by him from uraninitc 

 (devcitc) showing a line in the yellow which was statetl to be of 

 the same wave-length as D, which I had iliscovcred in 1868. 

 This line Dr. Frankland and myself shortly afterwards su^ested 

 might be a line of hydrogen not visible under latwratory con- 

 ditions, but solar work subsequently showed that this view 

 was untenable, although the gas which produced it w.as certainly 

 associated with hy<lrogen. 



Sut>sequenlly other chromospheric lines were found to vary 

 with the yellow line, and the hypothetical gas which gave rise to 

 them was pro\isionally named helium, to differentiate it from 

 hydrogen. 



It was therefore of great interest to me to leam whether the 

 new gas was veritably that which was responsible for the solar 

 phenomena in question : and I am anxious to tender my best 

 thanks to I'rof Ramsay for sending the tube to enable me to 

 form an opinion on this matter. Unfortunately it had lx;en used 

 before I received it, and the glass was so blackened that the 

 light was invisible in a spectroscope of sufficient dispersion to 

 decide the question. 



On March 29, therefore, as Prof. Ramsay was absent from 

 England, in order not to lose time, I determined to see whether 

 the gas which had lieen obtained by chemical processes would 

 come over by heating in vacuo, after the manner described 

 by me to the Society in 1879, and Mr. L. Fletcher was kind 

 enough to give me some particles of uraninite (Broggerite) to 

 enable me to make the experiment. 



This I did on March 30, and it succeeded ; the gas giving the 

 yellow line came over associated \\ ith hydrogen in goo<l quantity. 



I have since obtained photographs of the gas, both in vacuum 

 tubes while the Sprengel pump has l>een going ; and at atmo- 

 spheric pressure over mercurj". To-day I limit myself 10 

 exhibiting two of these photographs. 



One of the photographs exhibits a series of spectra taken 

 '(luring the action of the pump. The two lower spectra inilicate 

 the introduction of air by a leak, after the capillar)- had cracked 

 near one of the platinums, giving us on the <a\w. jilate the 

 handed and line s|x;c(nim of air. These prove that there was 

 no air present in the lul>e when the fourth spectrum wiis taken. 

 This photograph has not yet l>een finally reduced, but a 

 prelimmary examination has indicated that most of the lints are 

 due to the structure spectrum of hydrogen, but not all of them. 



Among the lines which cannot lie referred to this origin are 

 two respectively near X 447 1, and K 4302, which have been 

 observed in the chromosphere, 4471 Ijeing as ini|x>rl.inl .as D, 

 itself from ihe theoretical |Kiint of view to students of solar 

 phy.sics. 



Whilst s|x'ctrum No. 4 was tieing photographe<l with the 

 capillary lulie cnd-on-»i.se, eye ol>scnations were made in 

 another s|x.-ctrosco|)e <lirecled si<leways at it. I give from the 

 Laboratory Note Hook the oliservations I made while photo- 

 graph No. 4 was lieing l.aken, to show that the yellow line was 

 visible during the whole e.\|K)sure. 



Thurstlay, April 4, 1895. Plali F. Exposure ^. 



( 4.42 Exposure started. 



4.43 Yellow line brightening uj) consiilcrably. 



4.44 Suddenly .xs bright as hydrogen. 



4.45 Yellow line double. 

 4.4b rompari.vm with I) gives yellow line 111 iKisiiii.n 



of 1),. 

 4.47 Pump much less full, 7 c.c. of gas collected. 



Yellfiw line nnich brighter. 

 4.4>> .\ir break inlr'nluced. Line .still visible, but very 



faint. Hydrogen lines getting brighter, and 



some double lines ap|K-aring in green. 

 4-48.5 Air break and jar rcmoveil. Yellow line the only 



one sf<n, lieing .as bright as C. Line in green 



the only other line visdile. 

 4.50 keplared jar. Yellow brightening anil the other 



lines more refrangible, brightening with it. 

 \ery bright. Steeple nearly full of gas. 



chromosphere by Young or myself, or photographed during the 

 eclipse of 1893 : — 



1 



-Micrometer 

 reading. 



32495 

 •2917 

 •2981 

 •3234 



•33»6 

 •4146 



•5740 

 •5884 



■5933 

 ■6130 

 •6176 

 •6262 

 •6290 



Wave-length 



(Rowland). 



4581* 



4523* 



45 > 3* 



4479 



4469'5* 



436S 



4196* 



4181 



4177* 



4156' 



41525* 



4144* 

 4141 



I 4-5' 



4.52 



The lines . 

 tube and of t 

 lines indioii' 



I I'r. 



NO. 



I iKith in the photngraiihs of the capillary 



■led over mercury are as follows. The 



^terisV arc near lines recorded in the 



(•V J. Nrrrmiin I . 



1 33 1, \.)L. 52] 



With regard to the observations in the visual spectrum, 1 havt 

 not found the uraninite gas to contain the argon lines as given 

 by .Mr. Crookes, nor, with the exception of the yellow line, do 

 I get the special lines noted by him in the gas. (Kour of these, 

 out of six, seem ]iossibly to be due to nitrogen.) 



But I do get lines nearly coinciding with chromospheric lines 

 discovered by me in 1868. 



On November 6 of that year I suspected a line less refrangible 

 than C, and so near it that when Uiih were showing brilliantly 

 the pair appeared double, like I) in a sjiectroscope of moderate 

 dispersive power. 



Later I discovered another line at 6678 '3 (R), which was 

 observed to vary with Dj. There is a line in this position, with 

 the dispersion employed, in the s|X'ctruni of the new gas. This 

 line has also been seen by Thalen, ;us staled by Prof Cleve in 

 a communication to the Paris .\cademy (Comptcs reiidus. 

 .\pril 16, p. 835) ; but the other lines given by him (with the 

 |x)ssible exception of the one at 5016), have not lieen recordeil 

 liy me. 



.\llhough I have at present been unable to make final etini- 

 parisons with the chromospheric lines, the evidence so far cib- 

 taiiied certainly lends great weight to the conclusion that the 

 new gas is one effective in producing some of tlicm, and it is 

 suggested by the phologra]ihs that the stnicture lines of hydrogen 

 may lie responsilile for oilicrs. 



1 may state, uniler resene, ihal I have already obtained evidence 

 that the method I have indicaletl may ultimately provide us 

 with other new gases the lines of which are also associated with 

 those of the chromosphere. 



-Messrs. Fowler, Baxandall, Shackleton and Butler assisted 

 at various times in the investigation. 



NOTES. 

 Wk regret to report that Prof. Huxley is still in a critical state 

 of health. The slight imprtivement noticed in his condition last 

 week appears not to have Ijeen maintained. It is more than 

 eight weeks since his illness began with an attack of intlucn/a, 

 from the effects of which he is now suffering. 



M. NoRDENSKIOl.Ii has recently tliscovereil a uranium con- 

 taining mineral which may prove of great interest at the present 

 time. It forms carlxmaceous beds of which Ihe ashes contain 

 two to three |X'r cent, of uranium, and, in addition, traces of 

 nickel and rare earths. This uraniferous material is said lo 

 yield a considerable i|uantily ni iiitrogiii. 



Dr. Rkiiakii llAMisni has been a|ipointed Curator of the 

 Raffles Mu.seum at Singa|iore. Dr. Ilanitsch has occupied for 

 .some years the post of Demonstrator of Zoology in University 

 College, Liver|>Kil, and is the milicir .if a number of useful 

 papers on the British Sponge- 



TlIK third ceiUenary of (.'luisliait lluygens will shortly be 

 reached; for lhal celebrated Dulch physicist, astronomer, and 

 mathematician died at Ihe I I.ague 011 June 8, 1695. I lis investiga- 

 tions have been reviewed nl length in these columns during 

 recent years, and /'/< Xii/iir for .\prll 21 contains a notice 

 concerning I hem. 



