ANESTHESIA—KRANTZ 473 
gin is narrow, i. e., the anesthetic and fatal doses do not vary by a 
great degree of magnitude. Therefore, most anesthetists prefer to 
use the drug in amounts equal to three-quarters of its anesthetic dose 
as a basal anesthetic and to complete the relaxation with nitrous oxide 
or ether. The drug is contraindicated in patients suffering with 
hepatic or kidney diseases. It is unfortunate that all of our data on 
the efficacy and safety of tribromethanol are befogged by the fact 
that it is employed dissolved in another anesthetic agent, namely, 
amylene hydrate. Furthermore, avertin is a fixed anesthetic, and 
threatened collapse under agents of this kind is much more difficult to 
combat than it is under volatile anesthetics. Under the latter, removal 
of the mask initiates the immediate course of removal of the agent 
from the circulating blood. Obviously, when a fixed anesthetic agent 
is used, this safety factor is unavailable. 
DIVINYL OXIDE 
It occurred to Chauncey Leake (1) of the University of California 
in 1930 that it would be of great interest to prepare a hybrid molecule 
between ethyl ether and ethylene, i. e., a molecule which contained the 
essential features of the molecules of each of these anesthetics. Fol- 
lowing this suggestion Major and Ruigh (2) prepared divinyl oxide, 
“Vinethene.” The relation of these compounds to ethyl alcohol can 
be seen from the formulas. 
C:Hs 
C:H;0H 
oO 
Yo 
C2H; 
Ethyl! Alcohol Ethyl Ether 
136 18k H H 
| ! | | 
ih Hipage 
1S fy ise lef jat 1eG st 
Ethylene Divinyl Oxide 
Divinyl oxide is more powerful than ether. It is a liquid of very 
low boiling point. With it, anesthesia is rapidly induced, but owing 
to hepatic injury which may occur upon prolonged inhalation of this 
anesthetic agent, its use is confined to operations of short duration. 
One must not pass over the production of this new agent without pay- 
ing due tribute to the fertility of the mind that conceived it. In its 
conception a molecule was designed, synthesized, and anticipated 
properties were later discovered to be inherent in it. 
CYCLOPROPANE 
In 1930 Lucas and Henderson (3) of the University of Toronto 
announced the anesthetic properties of the hydrocarbon, cyclopropane. 
The structure of cyclopropane is seen in the following formula: 
CHa 
H,c2_Scu; 
