The Control of Insect Pests and Plant Diseases. 



599 



, ^i one is prepared and uses care and is thorough, fairly satis- 



" ^ , factory concentrated solutions may be made at home. Home- 



.. . made solutions will vary considerably and must all be tested 



~ , to determine the dilutions. They will probably contain more 



or less sediment, which is somewhat objectionable. The fol- 

 lowing method of making this wash is given by J. P. Stewart in Pennsylvania 

 Bulletin No. 99: 50 lbs. best stone lime (90-95% calcium oxide); 100 lbs. sulfur 

 (powdered commercial, 99^% pure) water to make 50 to 55 gals, total product 

 at finish. Put 10 gals, of water in kettle and start fire. Place lime in kettle. 

 After slaking is well started, add the dry sulfur and mix thoroughly, adding 

 water enough to maintain a thin paste, which requires about 5 gallons. After 

 slaking and mixing are completed, add water to make about 50 gallons, bring 

 to a boil and stir until the sulfury scum practically disappears. Then add 

 water to make about 60 gallons and boil down to 50 or 55 gallons. The material 

 should be kept well stirred, especially during the early stages of the process. The 

 time of boiling should be until the sulfur granules are evidently dissolved, gener- 

 ally 40 to 60 minutes. Pour or strain the clear liquid into a barrel or other storage 

 vessel that can be completely filled or corked and cut off air contact with a thin 

 layer of paraffin oil, or any other heavy oil. This prevents formation of crystals. 

 When ready for use, test the concentrate with a Beaum^ hydrometer and dilute 

 according to the foregoing table. 



Hydrocyanic acid gas is a deadly poison and the greatest care is 



Fumigation required in its use. Always use 98 to 100% pure potassium 



with hydrocy- cyanide and a good grade of commercial sulfuric acid. The 



anic acid gas. chemicals are always combined in the following proportion : 



Potassium cyanide, i oz., sulfuric acid i fluid oz., water 3 

 fluid oz. Always use an earthen dish. Pour in tJte water -first, and add the sulfuric 

 acid to it. Put the required amount of cyanide in a thin paper bag and when all 

 is ready drop it into the liquid and leave the room immediately. For mills and 

 dwellings, use i oz. of cyanide for every 100 cubic feet of space. Make the doors 

 and windows as tight as possible by placing strips of wet paper over the cracks. 

 Remove the silverware and food, and if brass and nickel work cannot be removed 

 cover with vaseline or with cloths. Place the proper amount of the acid and water 

 for every room in 2-gallon jars. Use two or more in large rooms or halls. Weigh 

 out the potassium cyanide in paper bags and place them near the jars. When all 

 is ready, drop the cyanide into the jars, beginning on the top floors, since the 

 fumes are lighter than air. In large buildings it ic frequently necessary to suspend 

 the bags of cyanide over the jars by cords running through screw eyes and all 

 leading to a place near the door. By cutting all the cords at once the cyanide will 

 be lowered into the jars and the operator may escape without injury. Let the 

 fumigation continue all night, locking all outside doors and placing danger signs 

 on the house. 



No general formula can be given for fumigating the diflercnt 



Fumigation of kinds of plants grown in greenhouses, as the species and varieties 



greenhouses, differ greatly in their ability to withstand the effects of the gas. 



Ferns and roses are very susceptible to injury, and fumigation 

 if attempted at all should be performed with great caution. Fumigation will 

 not kill insect eggs and thus must be repeated when the new brood appears. 

 Fumigate only at nij^ht when there is no wind. Have the house as dry as possi- 

 ble and the temperature as near 60 degrees as practicnble. 



