70 

 The materials used in fumigating were as follows: 



TRIAL I. 



Cactus room 



Stove room 



Cubic feet 

 space. 



7, 076. 25 

 7, 357. 31 



Amount 



potassium Watpr 

 cyanide W ater " 

 used. 



Oz. 

 '40 

 40 



Sugv.ric Time . 



Oz. 

 70 

 70 



Min. 

 30 

 30 



Result. 



No injury... 

 do 



Date. 



Nov. 9, 1897 



1 98 to 99 per cent pure. 



Ordinary glazed earthen jars, holding 2 gallons each, were first 

 placed in position. The potassium cyanide (40 ozs.) for each room 

 was tied in double thickness of paper and suspended by means of a 

 string playing over a support directly over the jars. This string was 

 held by an attendant at the door. The water was put into the jars 

 and then the acid. The cyanide was then lowered into the jars, the 

 door being immediately closed. The room remained closed for thirty 

 minutes and then the ventilators, which had been previously prepared, 

 were opened from the outside. The temperature of the house was 

 about 60° F. The conditions of the weather were perfect for such a 

 test, as it was raining, the water filling the cracks in the house, and 

 thus preventing the escape of the gas. It was also warm outside, so 

 the house was not cooled too low while the ventilators were open, and 

 it was perfectly dark. The ventilators were left open for over an hour 

 and then closed for the night. 



Results. — The room contained many different kinds of cacti, begonias 

 in variety, passifloras, allamandas, bananas in fruit, ferns, palms, and 

 a large variety of general stove plants. Not only were the mealy bugs, 

 scales, and aphides destroyed, but a large per cent of the sow-bugs 

 were found dead on the walks and under the moss which carpets the 

 floor of the solid bed in the stove room. Even the earthworms on the 

 surface of the soil under the moss were dead. 



After this many experiments were made with different plants and 

 insects put in a glass box containing about 42 cu. ft. of space; also 

 several practical tests were made in the greenhouse 1 (see table). 



TRIAL II. 



This was in a house containing 22,729 cu. ft. of space, using 1 oz. potas- 

 sium cyanide to every 285 cu. ft., with If oz. sulphuric acid and 1 oz. of 

 water. This house contained carnations, smilax, violets, coleus, chrys- 

 anthemums, small lettuce, cuttings, and small plants of bedded stock. 

 It was infested with the common mealybugs (Dactylopius destructor), 

 green fly, and the white-tailed mealy bugs (Orthezia insigniS), It Avas 

 fumigated for 30 minutes upon a cloudy morning, yet in daylight. The 



l It is to he regretted that no notes were kept on the effect of this treatment ou 

 the plants. — L. o. n. 



