COLD-STOEAGE EXPERIMENTS, 1906-7. 



25 



wide piece of heavy linoleum was used, and the framework screwed 

 down firmly all around, also using felt strips to insure tightness. 

 This made a very tight box which proved quite satisfactory for the 

 work. The necessary potassium cyanid was divided into four parts, 

 one of which was used near each corner of the fumigatorium. 



To provide for removal of gas at end of period of exposure a 

 large canvas box, 12 by 12 inches square, extended from a slide 

 door opening at the rear of the fumigatorium to an adjacent window. 

 A large electric fan was placed inside the fumigatorium and operated 

 from the outside, forcing the air toward the outlet. With this 

 arrangement it required about twenty minutes to sufficiently clear 

 the box of gas to permit of opening it. The whole outfit was placed 

 in one of the cold-storage rooms of a local cold-storage plant, in 

 which the temperature was uniformly 30° F. This furnished oppor- 

 tunity to determine the effectiveness of the gas at a comparatively 

 low temperature and under conditions which might become neces- 

 sary in the actual fumigation of fruit in cold-storage houses. 



Packages Nos. 60 to 67 were fumigated January 29 and examined 

 for condition of scales on February 21. Nos. 68 to 70 were fumi- 

 gated February 25 and examined March 15. These latter were made 

 to repeat some of the earlier tests, to secure corroborative data. 

 The fruit used was of the Baldwin variety and had been held in the 

 same cold-storage room since October, and undisturbed in the original 

 barrels, except that used in boxes which was packed from one of the 

 barrels of this lot. In Table IX the features of the work are pre- 

 sented more in detail: 



Table IX. — Effect of fumigation with hydrocyanic-acid gas on scales and fruit at cold- 



storage temperature, 30° F. 



E S" Variety of 

 Z n l 1 apple. 



Kind of package 

 (fruit dry). 



Rate at 

 which 

 potas- 

 sium 

 cyanid 

 was used. 



Length 

 of ex- 

 posure. 



Num- 

 ber of 

 scales 

 exam- 

 ined. 



Effect on 

 scales. 



Effect on 

 fruit. 



60 



62 



Baldwin 



do 



Barrel, each end with 

 twenty f-inch auger 

 holes. 



Barrel, top open 



Barrel, iron header in 

 bottom. 



Box, fruit unwrapped. 



....do 



Gr. per 

 en. ft. 

 0.30 



0.30 

 0.30 



0.30 

 0.30 

 0.30 



0.30 

 0.30 



0.30 



0.30 



Hours. 



1 



3,600 



3,250 

 3,800 



3,600 

 2,330 

 2,400 



2,230 



All dead 



do 



do 



do 



do 



do 



do 



No injury. 

 Do. 



63 do 



64 do 



65. do 



Do. 



Do. 

 Do. 



66 



67.. 



Rhode Island 

 Greening. 



§ bu. basket 



do 



No record. 



No injury. 

 Do.' 



68... 



do 



Barrel, top open 



Barrel, iron header in 



bottom. 

 Barrel, each end with 



15 1-inch auger holes. 





69 



do 



2,950 

 3,400 



doubtful. 



1 scale doubt- 

 ful. 



All dead 



Do. 



70.. 



do 



Do. 









