474. ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
The gas is more potent than ethylene and hence permits the admix- 
ture during anesthesia of a larger percentage of oxygen. Relaxation 
of abdominal musculature is good during cyclopropane anesthesia. 
During the decade of its use the gas is now established as an impor- 
tant and dependable agent. Recognition of it in the United States 
Pharmacopeia XII bespeaks its growing field of usefulness. A 
brochure by Robbins (4) of Vanderbilt University on cyclopropane 
reviews the entire field. 
CYPROME ETHER 
At the Medical School of the University of Maryland in 1939, 
Krantz, Evans, Carr, and Forman (5) succeeded in developing a 
chemical reaction for the convenient preparation of aliphatic cyclo- 
propyl ethers. Four of these ethers have been prepared already, and 
three of them have had preliminary trial. One of these agents is 
cyclopropyl methyl ether known as cyprome ether; its structure can 
be seen by the following formula: 
CH; 
H,c<Sc—o—CHs 
i 
The pharmacologic studies conducted in the University of Mary- 
land show cyprome ether to be more potent than ethyl ether and pos- 
sibly safer. Its boiling point is 10° C. higher than ethyl ether which 
should be a distinct advantage for anesthesia in the Tropics. Black, 
Shannon, and Krantz (6) in 1940 reported the first 25 human cases 
of anesthesia with cyprome ether in “Anesthesiology.” ‘The compound 
appears to be promising. 
Other new anesthetics which have been produced by these investiga- 
tors and are under study at the present time are: 
CHa CH: 18h 13! 
07 c—o—c.: H2C c-o—bad 
i i i 
Cypreth ether Cyprethylene ether 
H 
and ¢=c—o-c=t 
Bimal oat 
H CH; H H 
Propethylene ether 
PENTOTHAL SODIUM 
Many years ago Frinkel prepared certain thiobarbituric acid com- 
pounds. Based upon insufficient evidence upon a very limited number 
of animals these compounds were discarded as not being worthy of 
therapeutic merit. Within the past 5 years these compounds have been 
reinvestigated and found to be very prompt-acting barbiturates, yet 
