SOLIDIFIED HELIUM.

Dominion, Volume 1, Issue 175, 18 April 1908, Page 5

SOLIDIFIED HELIUM.

HOT-YET A PACT. AN EXPERIMENTER'S MISTAKE. ■ ; HYDROGEN GOT IN. ti -iiusaiuFn—rnKss association—oorrniani. . (Roc. April 17, 0.30 a.m.) • London, April 16. ' It i was reported, on March 6, that Professor- Kamorbugh Ohnes, of Loyden Univorsity, hadinformed Sir James Dowar that ho had converted holium (a gas, ono of the'argon sorioß of elements) into a solid.

Profossor Dowar now explains that tho roported . solidification'of holium by Professor Ohnes was due'to the fact that tho holium treated got mixed with a slight percentage of hydrogen,: and consequently, tho liquefaction and tho solidification of helium wore not achieved. •• . ■ .:<■ . . ■ THE QUEST OF THE ABSOLUTE ZERO; ■ '.PROBABLE CAUSE OF EEROE. - Hydrogen, .which has ■ been; solidified ;andliquefied,, is us'ed in tho experiments to. solidifyand liquefy helium, which is also a gas. ■ To •; show, the-' direction of : these experiments, it may be stated that tho point aimed , at .'ultimately is .the absolute zero;' "the point at. '.which; all -bodies would be deprived of heat energy." To show how far tho scientists have progressed l and are progressing towards zero, it ■may.'be stated that ithe" temperatu res—stated■ on;tho.:absolute scale-T-at which the'following . Eas'^'''lMColrie"liqiiidV are Chlorine- aiOdeg., •*:air ; 80deg.,\> hydrogen"; 20deg;'.- • As 'Professor . Dewar . has remarked;-, "the step 'between the liquefaction /of' air iarid that of • hydrogen: is/ theririodynamically - and -practically, ■ greater than that between- the liquefaction of/chlorine and. that of air." V . 1 , Th'd' lower? down)'the' scale," the greater the difficulty;: of .transition from.; one .tomperature' 'to the -otherl'.-lit is 'estimatedthat'to liquefy helium a '.point iof s■' deg.'absolute must .be reached; or 'about one-fourth .that of hydrogen. According to a . recent / writer, .the 7 hydrogon point,'/20deg. 7 absolute,';''is/'- 'about' '".the lowest temperature at which we can continuously keep a. body'long enough" to examine its properties." A--.transient, temperature' of : 9deg. -or-.lOdeg. absolute;.has been reached, without liquefying helium;, hence the calculation that the ; result will /not' be, attained without reaching ■ sdeg., it will,-therefore, be .at least as hard-to'pass .the interval between hydrogen and helium .as it was ;,to-..pass,, from, that of air to that of hydrogen. ' • : •/; v'V'" '• ' Nevertheless, 'it is ' hoped that success/ is merely a matter-'of expense and' labour.' : -It> is believed that : by, the .regenerative - cooling. ot helium, previously- cooled, by liquid hydrogen, boiling ;under diminished .'pressure, ■ a temperature lower 7,than : . any/ yet.' attained could be reached; arid that, by this-means, the last-i known "permanent" gas, will yield to: the' skill '.atid ,J .'perßeVerance" of- scientists like --Professor Dewar. " 'Apparently,'in' Professor OhnesV case, the hydro|en used in the preliminary cooling became/mixed .with the,helium, : in a gaseous, state, and that the- helium remained gas, while • the hydrogen; 1 ' yielding 'to a '.higher, tempera- ■ ture; .became liquid;' deceiving, the investigator. He thought-it was/liquid helium; /whereas it was liquid; hydrpgeri..' .; S-'';/ /'.' V - • ..Scientists'Regard .'.the' sdcg. point,' at which helium is to be liquefied, as' "almost- within, sight.'%; ; ,Those 'in" pursuit of :the.- absolute zero regard helium/aa the meahs .of getting down to the sdeg. point. :To go farther, they must, apparently, discover, .a; new "permanent":, gas. -thei future,: a new' gas, similar '.io, helium, but of less density, , should be :dis-covered,/we-should find that it was still .more, 'difficulty to liquefy.; By, 'using 'liquid helium as'-'a' means of preliminary cooling, /the ; resist-! ance of this hypothetical gas may, possibly be overcome, and, by. collecting it in open vessels under the atmospheric pressure, a steady temperature, of. ldeg. or 2deg. absolute may some day be' placM'at'the'disiiosal of the physicist/'