PHYSIOLOGICALLY ACTIVE GASES 155 



Measured by volume or wet or dry weight increase, the reduction m 

 percentage growth would be much greater. It will be noted that the lower 

 concentration mduced epinasty in the older leaves of the tomato plant. 

 Even so, the question arises whether epinasty of tomato leaves is sensitive 

 enough to detect the lowest concentration of artificial illuminating gas in 

 greenhouses that will retard gro\nh. If not, epinasty m the leaves of 

 potato or marigold vnW do so. Greenhouse operators will do well to keep 

 young plants of all of these growmg in their greenhouses continuously if 

 there is any danger of injury from leaking gas pipes. 



From observing the work on the effect of ethylene on plants done m the 

 botany department at the University of Chicago, Dr. Luckhardt of the 

 animal physiology department of the same institution became interested in 

 the effects of ethylene upon animals. He and associates *^' ^'^ found it to 

 be a rather remarkable anesthetic for higher animals and man, but it must 

 be used in high concentration, 80 per cent or more, i^-ith oxygen. The 

 authors cited describe its use m 800 operations at the Presbyterian Hospital 

 at Chicago. They mention several advantages of ethylene as an anesthetic 

 in surgery under the headings: (1) ease of induction and rapidity of re- 

 covery; (2) relaxation \dthout cyanosis; (3) absence of sweating; (4) ab- 

 sence of respiratory u-ritation; and (5) narrow anesthetic margin. They 

 list as disadvantages: (1) odor; (2) oozmg from wound; and (3) danger of 

 explosion. They state that it is no more explosive, however, than ether. 

 In 1938 Luckhardt was awarded the Alpha Omega medal as discoverer, 

 with J. Bailey Carter, of ethylene as an anesthetic with qualities superior 

 to nitrous oxide. 



Chipman,^ an anesthetist of Washington, D. C, ranks ethylene-oxygen 

 first among anesthetics kno\\Ti and in use up to 1931. Dr. H. M. Living- 

 stone, Chief Anesthetist at the University of Chicago Clmics, says that 

 ethylene-oxygen is enjoying its greatest popularity in the midwest and some 

 in California. She describes"^ the use of ethylene-oxygen in 6590 cases, 

 mostly \\'ithout the accompaniment of other anesthetics. She also states 

 that to date she has used ethylene-oxygen in about 50,000 cases ^^^thout 

 death or explosion. Luckhardt states that John S. Lundy ^^ of the Mayo 

 Clinic used ethylene-oxygen in an even greater number of cases udthout 

 mishap, but that lately he is using mainly an intravenous anesthetic. 



Dr. Poe ^2 considers ethylene-oxygen the best anesthetic kno\vn to date 

 and finds no danger of explosion if it is properly applied. Drs. Guthrie of 

 Sayre, Pa., and Woodhouse of Cedar Rapids, Iowa, confirm this view and 

 describe 35,500 operations conducted with ethylene-oxygen either as the 

 sole anesthetic or m conjunction with ether. They say:^^' pi^^" "It is our 

 opinion that ethylene is an excellent anesthetic agent for general surgical 

 use and that an unjust prejudice exists in the mmds of the surgical pro- 

 fession ^^^th respect to its widely heralded disadvantages." The anesthetic 

 used by anesthetists seems to depend to a great degree upon the anesthetic 

 in use where they were trained. On the whole, however, ethylene-oxygen 



