FORCING OF LETTUCE 211 



used. People are perhaps sh\ about liandling this poison until they ha\e used 

 it a few times, alter \\ hich they will admit it to be one of the simplest of fumi- 

 gating materials. It is merely a question of knowing the proper strength for 

 destroying insect life. Anyone who has not had experience with this gas should 

 experiment with a very weak application at first, gradually increasing the 

 strength until satisfactory results are obtained. The foliage must be dry when 

 the gas is used, and choose a calm night. The first operation w ill in\ oK e a little 

 more trouble, on account of the preliminaries. First < f all we must compute 

 the cubic content of the house. Then, if two or more receptacles arc required. 



Ideal Lettuce 



ill be 

 large 1 



Lettuce Ide.^l 

 cellent fur growing through the short days. Although 

 t is quick to mature and produces solid heads 



the cyanide must be divided into equal parts, and each package tied in tissue 

 paper. There must be enough water and sulphuric acid in the jars to just 

 cover the cyanide, or one pint of water and one-half pint of sulphuric acid for 

 two or three ounces of cyanide. Get the best commercial acid. When every- 

 thing is ready and the house closed up tight, pour first the water into the jar and 

 then the sulphuric acid, then drop in the cyanide, starting at the far end and 

 working toward the door. Merely drop in the poison and get out as quick as 

 you can, not waiting to see whether it is beginning to boil up or not. Then 



