490 STATE BOARD QF AGRICULTURE. 



about fifteen bushels of sacked wheat, and a little corn in the ear, stored 

 in the room. In the first test (Oct. 7, 1911) ten pounds of ammonia were 

 passed through the tube. Since the air-space where the gas expandled 

 was 7166 cubic feet, the percentage of ammonia was about 3.1 in the 

 early part of the test. The experiment ran between nineteen and twenty 

 hours. A caged specimen of the large American cockroach was still 

 alive at the end of the test, but he was so under the influence of ammonia 

 that he died from the efl'ects later. S. surinamensls and C. granaria in 

 one of the exposed cages were motionless. Some of the Calandra recov- 

 ered in fresh air enough to move their legs, but none ever recovered en- 

 tirely. All the beetles in the two cages buried in the wheat were active 

 at the end of the test and w^ere still alive and normal three days later. 

 The next day living specimens of the saw-tooth grain beetle were found 

 between the grains of the corn in the ear. 



On November 21, 1911, the mill was again fumigated with ammonia in 

 the same manner as in the first test; but this time 32.5 lbs. of the com- 

 pressed ammonia were used — i. e., one pound of ammonia gas to 223.9 

 cubic feet of air space. This gave about ten per cent of ammonia in the 

 room. One hour and fifteen minutes were used in introducing the 

 charge, and the room was kept closed (over night) for seventeen hours. 

 Wire-caged insects had been introduced again, as well as several large 

 sacks of infested wheat. About twenty bushels of new corn that was not 

 very dry was present also. The latter became very decidedly darkened 

 during the test. Wheat Avas always more or less darkened by ammonia 

 fumigation in the laboratory tests — as well as in the mill test — but the 

 dryev the grain, the less noticeable was the darkening in every case. In 

 this test, a caged cockroach (P. americaim) became quiet by the time 

 the charge had been two-thirds introduced. The roach was dead at the 

 end of the test, as were also the caged beetles left in the open. Mice were 

 killed. One mouse was seen to come out on the floor and die when fumi- 

 gation had been going for forty-five minutes. Insects about one inch 

 deep in the wheat Avere killed, but caged beetles (saw-tooth grain beetle 

 and grain weevil) buried in the center of a sack of wheat were active 

 at the end of the test. In both the mill tests brass and copper parts of 

 the mill machinery were covered with vaseline, which protected them 

 perfectly from action by the ammonia. The compressed ammonia was 

 certainly convenient to apply; and at three to four per cent, fumigation 

 could be carried on with the gas at a reasonable cost, since iron cylind- 

 ers of liquefied ammonia could be obtained at that time for twenty-nine 

 cents per pound. Considerable of the ammonia was absorbed by the 

 grain; but after a few hours airing, the odor disappeared. The dark- 

 ening of the grain seemed to be an undesirable feature, however. Mr. 

 Spragg of the Farm Crops Department prepared flour from three kinds 

 of wheat treated in the first mill experiment — and also, from the three 

 corresponding check samples of Avheat. There was no taste of ammonia 

 on any of the flour, but that from two of the treated samples of wheat 

 was quite noticeably darker than the corresponding checks. A Lansing 

 miller, who was kind enough to slick the samples of flour and judge 

 them, decided that the action of the ammonia on the wheat had undoubt- 

 edly injured its milling qualities commercially. To be sure, the grain 

 was really darkened, noticeably, to a depth of only two or three inches 



