purc osygcii. 'l'ltc Iiytlrogcii ~v i i s tlicii 1)uritt. over IJitlladiiiiii, speciiil precitutioits bcitig t.itkcti to iivoitl tlift'usioii of ;it,mosplicric Iicliiini into t.lic itppiiriitits t,Itrougli t h hot glitss. Tlin Iicliuiii wiis thcit scptriitctl froiti rcsitluiil osygctt hy iilJsorl)iiig tlic hitter i t t clt:ircoal coolerl iii liqiiitl air. A ittiitutc itiitoiiiit; of giis wits Iclt, :I i d \vheii this \vits coiiil)rcssctl into i i Iiite txtpilliiry i i i i i l csitiiiiited ~l ) ~~t . ~~~~~p i ~i i l l y , it slto\vctI Itcliiitt~ liitcs. 111 ii I)I:itik csl~criitictit, iti which tlie itlcthyl h i i t c WIS trot I)oiiibiirdctl wit11 itciitroiis, 110 Iicliuiit w i s prescitt :it tltis stiige. 'rlic I i i t i i I tiiciisiirciiictit. of tltc :iLisolrtt,c iiittouitt of Iieliuiit \WS It1ide ivit.11 it I'irttni giiiige, in wliieli the Iieiit losses froiii ii hot wire arc iisetl to titeiisurc t.11~ pressiirc of thc siirroiiiitliitg gas.
'l'lic siii:tlliicss of tltc qitrtiititics of Ileliuiii dctcctetl Iiy tAis tiictltod mny he jiidgcd froiii the fact tltilt
of itcliiiin \vns foiiitd. So grcnt is the prccisioti of t,lio iiiethotl, Iiowcvcr, that iiti ricciiriicy of iihoiit 207" is clnititcd for this restilt. Intleetl, it is rciisoiiiibly certniti t l i n t this heliuiii wiis fortiietl by tlic itiipiict of itcutroiis oil boroii. This result should be n sourci! of grciit sntisfitctiott to chetiiists, for it has funtislictl ii tlircct espcriiiiciititl t,cst, of one of t,hc tiiost iinportiiitt rcctwt dc~clopinciits in physics.