INSECTICIDES AND FUNGICIDES 11 



shoots on the ground, otherwise the fungus will fructify 

 and produce spores or mycelium that will later on attack 

 the next crop. 



If everyone would make a point of burning every scrap 

 of diseased plant directly it is seen, many diseases would 

 be soon stamped out. The day will come, let us hope, 

 when it will be a penal offence to allow diseased plants, 

 etc., to continue to grow and spread further destruction. 



No matter how valuable a plant may be, it is unwise to 

 try to save it if badly diseased. Eemember, each solitary 

 insect is capable of propagating its species largely, and 

 each individual patch of fungi to develop millions of spores 

 to be carried by the agency of birds, insects, wind, etc., 

 to other and healthy crops. 



Sureh', but swiftly, all pests should be destroyed at the 

 earliest moment, and then the gardener will meet with 

 less worry, and his crops enjoy greater freedom from pests 

 and disease. 



CHAPTER II. 



INSECTICIDES AND FUNGICIDES. 



PRINCIPAL INGREDIENTS. 



Below we give a brief description of the principal mate- 

 rialis for making insecticides and fungicides. 



Hydrocyanic Gas. — This is produced by mixing 

 either potassium cyanide (98 per cent.) or sodium cyanide 

 (130 per cent.) with sulphuric acid and water. The result- 

 ing gas is a deadly poison, and will cause death if inhaled. 

 See chapter on " Cvaniding." Caution: The cvanide must 



B 2 



