152 The Spraying of Plants. 



Against authracnose of the grape the following application 

 has shown itself to be of great value, and it is regularly used 

 by European vineyardists : 



Water (hot) 100 parts. 



Iroii sulphate, as much as the water will dis- 

 solve. 

 Sulphuric acid 1 part. 



Great care should be exercised in using this preparation, as 

 it is exceedingly caustic and will injure machinery, clothes, and 

 nearly everything with which it comes in contact. It is gener- 

 ally applied with a swab made by tying rags about the end of 

 a stick. Dormant vines are uninjured by the treatment. 



JOHNSON'S MIXTURE; COPPER SULPHATE AND AMMONIUM 

 CARBONATE MIXTURE. This preparation is almost identical 

 with the modified eau celeste, ammonium sulphate being formed 

 by the reactions instead of sodium sulphate. The former is 

 injurious to foliage, and for this reason the mixture never has 

 been used to any extent. It contains dissolved copper carbon- 

 ate, as does the ammonia solution of the same compound, and 

 that fungicide should be consulted in connection with John- 

 son's mixture. 



Copper sulphate 8 ounces. 



Ammonium carbonate 1 pound. 



Dissolve in a pail of warm water and then dilute with 

 Water 25 gallons. 



KEROSENE; COAL OIL; (PETROLEUM). Kerosene has been 

 used to destroy insects almost from the time of its first general 

 introduction for illuminating purposes. It was originally used 

 in two ways : first, when pure, in which case it was carefully 

 used and applied as much as possible only to the insects to be 

 destroyed; and second, when mixed with water, generally at 

 the rate of 1 gill to 1 or 2 gallons of water. Since the oil is 

 lighter than water, such mixtures were imperfect, and a certain 

 amount of skill was required to obtain a mixture sufficiently 

 uniform to prevent injury to the foliage. A small hand-syringe 

 was the instrument generally employed, but now special ma- 

 chinery has been devised for the same purpose. Such appli- 



