THE SPRAYING OF PLANTS. 



PART I. 



THE HISTORY AND PRINCIPLES OF 

 SPRAYING. 



CHAPTER I. 



EARLY HISTORY OF LIQUID APPLICATIONS. 



MAN'S power over the organisms which injure cultivated 

 plants was never so great as it is at the present time. One by 

 one these enemies have been carefully studied, the history of 

 their lives determined, and their habits observed. Only by 

 understanding them thoroughly can proper steps be taken to 

 check their ravages in the most economical and efficient man- 

 ner ; yet it is within comparatively recent years that this first 

 step was taken to obtain the mastery over them. Formerly, 

 when a pest injured a plant, it was no uncommon practice to 

 apply any remedies or materials that came to hand, regardless 

 of their probable efficiency. It was not generally the weakest 

 point of the organism that was assailed. In many cases it was 

 not even the proper organism which was held responsible for 

 the injury. Nevertheless many valuable discoveries came from 

 these varied and desultory treatments, and some of the remedies 

 most highly prized to-day were discovered merely by chance, 

 not very many years ago. 



Present knowledge and methods of investigation, largely 

 founded upon this experience, enable us to arrive at conclu- 



B 1 



