N, a. state uonea^ 



AUTHOR'S PREFACE. 



Evert year the diseases of plants become more numerous, their 

 economic importance increases, and the number of those in- 

 terested becomes greater; more numerous by the means of 

 communication estabhshed between different countries, and by 

 more frequent commercial intercourse ; more important and 

 more dangerous because they prevent the heavy yields of dif- 

 ferent crops which should be obtained from the high farming 

 with which the prosperity of our farmers is so closely associated ; 

 the number of those interested increases because gardening for 

 pleasure, ornamental horticulture, extends daily more and more 

 amongst all classes of society. It therefore becomes indispens- 

 able that the farmer, the gardener, and the amateur flower 

 grower should possess a treatise in which they can easily find 

 the cause of the diseases which dishearten them, and at the 

 same time an efficient remedy capable of circumscribing them 

 and of preventing their return. 



So as to render this treatise complete in itself it was deemed 

 necessary to pass in review the numerous experiments made up 

 to now to suppress and prevent plant diseases. 



The author has striven from the aggregate of the results 

 reported to frame certain scientific rules which appear to deter- 

 mine the success of certain classical methods and to explain 

 certain notorious failures, rules which may serve as a useful 

 guide to future experiment and aid in the discovery of new pro- 

 ducts of greater efficiency than those now at our disposal. 



The preventive and combative treatment of the diseases of 

 plants requires a profound knowledge of the parasite as well as 

 the product used as a remedy. Success depends on the judicious 

 choice of the remedy utilized and the manner in which it is 

 applied. 



The plan of this book is therefore conceived in such a way 



