766 
Journal of Agricultural Research voi. xxvn. No. io 
is ethylene present in the combustion products oe 
KEROSENE STOVES? 
No delicate specific qualitative test for ethylene in a mixture of gases 
was found. An attempt was made to isolate ethylene from stove gas 
by bubbling it through bromin water. This was done for periods of 6 
to io days, about seven hours a day, on three different occasions, the 
absorbing tube being surrounded by ice in one case. No detectable 
quantity of bromid was obtained. It is believed, however, that ethyl¬ 
ene, if present in stove gas, occurs there only in traces. If so, it would 
be difficult to detect it in this way. Thus, on the basis that 15 gm. 
of ethylene dibromid would be needed for the identification tests, if 
ethylene were present at a concentration of 1 to 1,000, it would be neces¬ 
sary to bubble stove gas through bromin for 24 hours a day for about 
1 8% days. At a concentration of 1 to 10,000 about six months would be 
required. 
Aside from the fact that ethylene and stove gas produce similar 
effects upon green fruit, there are other reasons for believing that ethyl¬ 
ene is present in stove gas. Ethylene has been found among gases that 
are produced in the cracking of petroleum (it). Denig (4) obtained 
ethylene as one of the products of the decomposition of kerosene by heat. 
According to Eldred and Mersereau (7), ethylene is produced by heating 
kerosene vapor under certain conditions. Lewes (10) states that ethyl¬ 
ene is “ found as one of the products in nearly all cases where organic 
compounds are subjected to distillation at high temperatures. ” A further 
fact pointing to the same conclusion was obtained when, in attempting 
to remove oxygen from stove gas by phosphorus, the phosphorus would 
not burn. White {19) states that “a fraction of a tenth of a per cent of 
ethylene will completely prevent the reaction between phosphorus and 
oxygen." 
ETHYLENE FROM THE PRACTICAL STANDPOINT 
EXPLOSIVE AND ANESTHETIC PROPERTIES 
The sources, chemical behavior, physical constants, and important 
commercial uses of ethylene are discussed fully by Curme (3) and by 
Malisoff and Egloff ( 13 ). In connection with the experiments here 
reported two properties of the gas need to be discussed: 
(a) When ethylene is mixed with air in proportions above 3 per cent 
by volume and below 30 per cent by volume, the mixture may be ex¬ 
ploded by ignition. In liberating ethylene from the cylinder into a room 
containing fruit to be colored, however, explosive concentrations are not 
reached. To reach such proportions in a room of carload capacity, say 
3,500 cubic feet, it would be necessary to liberate about 100 cubic feet of 
ethylene, or about one-third of the entire contents of a full cylinder. 
The lowest explosive concentration is at least 100 times as strong as the 
strongest application of gas needed for successful coloration. 
(1 b ) Luckhardt and Carter (12) have found that animals, including 
human beings, can be anesthetized by ethylene at a concentration of 80 
per cent ethylene and 20 per cent oxygen. The effectiveness, however, 
decreases rapidly with decreasing concentration. Thus Smith and 
Hoskins ( 18) were unable to anesthetize or injure a mouse with 72.5 per¬ 
cent ethylene and 27.5 per cent oxygen by exposure for one hour. The 
writer has freely breathed the pure gas as it comes from the cylinder and 
