130 FUMIGATION METHODS 



How to prepare the jar. The chemicals should be 

 prepared strictly in accordance with directions given 

 in Chapter II. An earthenware crock or jar will be 

 needed, the size of the vessel depending upon the 

 capacity of the enclosure. The number of vessels 

 needed will depend upon the size of the house to be 

 fumigated. In a small-sized house single jars may be 

 sufficient, but as a rule it is desirable to use two or 

 more crocks or vessels. After the acid and water have 

 been mixed and placed in the vessels, the cyanide, 

 which has been previously weighed and wrapped in 

 strong manila paper bags, is suspended over the crocks, 

 as shown in the illustration. 



Several hooks or screw-eyes can be used conve- 

 niently to carry the string from the door to the vessels. 

 There should be as many lines of string as there are 

 vessels, each one leading to the door or outside open- 

 ing, as shown in Fig. 70. If the building requires 

 four pounds of cyanide and two jars are to be used, it 

 is desirable to divide the cyanide into equal parts. 

 Before the acid and water are placed in the jars, it is 

 well to tie the bags of cyanide to the cords and see 

 whether or not they work satisfactorily. Care should 

 be taken to see that the bags when lowered will go 

 into the crocks, and thus into the chemicals, without 

 difficulty. 



At times it is necessary to use some protection 

 around the jars to prevent the injury of the foliage in 

 case plants are too near. A section cut from a roll of 

 building paper can be used to good advantage, as the 

 paper rolls in a tube and can be placed around the 

 vessel, thus keeping the acid and water from spattering 



