The Therapeutic Administration of Oxygen.

interference wvitlh tlhe respiratory or cir'culatory ftunctionis; but sufficienitattention lhas not hiitlherto been paid eitlher to whlat precise benefit m-ay be. expected from thjo admiiinistration of oxygeni, or to lhow it can best; be admrinistered. In thle present paper I propose to discuss both thiese questionus in thea' lgt of existing plhysiological knowledge, and to describo aIn annaratus designed for the clinlical administration of oxyg, ii OLIr knowledgo of the physiology of respiration lhas advanced very rapidly withllin the last few years, and certain points wlich lhave been eluLcidated in this advance mnust fist be referred to. Undernormal conditions the breathling is so-regulated as to keep the miean percentago of C002 in the air of tilelun alveoli practically constant at