FUMIGATION AGAINST GRAIN WEEVILS 35 
“old process” and ‘“‘new process” grades of ethyl acetate completely 
volatilized from the grain, so that no odor was noticeable in the 
process of milling, and the loaf, hot or cold, had only the natural 
odor and flavor (samples 11024 and 11025 in Tables 10 and 11). 
The suitability of a sample of ethyl acetate for fumigating grain 
should be determined by the following test: Wet a sheet of filter 
paper (11-centimeter diameter is a convenient size) with the ethyl 
acetate, and allow it to evaporate, noting the odor from time to 
time. No foreign odor should be present, and the liquid should 
volatilize completely without leaving any odor. The carbon tetra- 
chloride to be mixed with the ethyl acetate should be similarly 
tested, and should likewise be free from odoriferous constituents of 
low volatility. The presence of sulphur compounds in carbon tetra- 
chloride is particularly objectionable because they give a garlicky 
odor to the fumigated grain. Ethyl acetate and carbon tetrachloride 
of a grade which satisfies this test are now commercially available 
in large quantities at a price but shghtly higher than that asked for 
the commercial grades. 
ADDITIONAL FUMIGATION TESTS WITH ETHYL ACETATE AND 
CARBON TETRACHLORIDE 
In August and September, 1924, car fumigation tests were made 
with a mixture of ethyl acetate and carbon tetrachloride combined 
in a ratio that would make a noninflammable product at ordinary 
temperatures. The results are shown in Table 14. 
TaBLE 14.—Results of fumigation tests on weevils in wheat in box cars, using a 
mixture of 40 volumes of ethyl acetate with 60 volumes of carbon tetrachloride 
Insects killed at different levels after exposure for 
Rela- 24 hours 
ee tive- | Con- | 4¥er Insects 
em- A age : 
Date pera- humid-| cen- ee in 
¥ tara ity | tration tality 1 grain 2 
(noon) 
Level 9 
Level 10 
Lbs. per 
,000 Per | Per | Per| Per| Per| Per | Per | Per | Per | Per 
1924 °F. |Per cent) cu.ft. |Per cent) cent | cent | cent | cent | cent | cent | cent | cent | cent | cent | Per cent 
Aug. 26 78 68 30 80 | 100 | 100; 50] 50] 50{| 100} 50} 100 | 100 | 100 100 
26 78 68 40 96 | 100 | 100 | 100 | 100 | 100 | 80} 80} 100] 100 } 100 (3) 
27 78 41 40 99 | 100 | 100 | 100 | 100 | 100 | 100 | 90 100} 100 |} 100 100 
27 78 41 40 99 | 100 | 100°} 100 | 100 | 100 | 90} 100} 100 | 100 | 100 100 
27 78 41 40 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 } 100 | 100 99 
28 80 61 50 100 | 100 | 100 | 100 } 100 | 100 | 100 | 100 | 100 } 100 | 100 100 
Sept. 3 66 53 40 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 100 
3 66 53 40 100 } 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 100 
4 66 45 40 486 | 100 | 100 |} 100 | 100 | 100 | 80); 90] 90] 80} 20 100 
6 60 41 40 98 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 80} 100 | 100 (5) 
6 60 41 40 97} 90/100} 90] 100} 100 } 100 | 100 | 100 | 100} 90 (5) 
9) 78 51 AQ) ea oe aes No weevils; sampled for milling and baking tests. 
2 78 51 ADT ae oe Do. 
2 78 51 yt ee Do 
2 78 51 AOS |= EE 2 Do 
1 For insects exposed in pill boxes. 
_ 2 The grain in all but six of the cars fumigated was moderately infested with weevils. The percent- 
ages given in this column represent the kill of this infestation. 
3 A few alivein ends of car. 
4 Fumigation interrupted when halfway through for 10 or 15 minutes, during which time the car door 
remained open. 
> No weevils. 
