Historical 3 



tributed to the knowledge of plant disease and served 

 especially to awaken interest in the problems of, and to at- 

 tract students to, this field of research. 



In 1879 Burrill, working upon the blight of the pear and 

 apple, was the first to attribute a plant disease to bacterial 

 origin. His work was confirmed and his conclusions more 

 fully established by Arthur. 



During the seventies, from two or three workers in this 

 field, the number rapidly grew, augmented in the middle 

 eighties by the introduction of plant pathology into the 

 Agricultural Experiment Stations and the United States 

 Department of Agriculture, until the number of papers 

 pubHshed in the United States upon plant pathology be- 

 tween 1888 and 1900 is estimated at over four thousand. 

 While only a few dozen plant diseases had been even cursorily 

 described in the United States prior to 1880, in 1910 a total 

 of some 525 diseases, of which more than 250 were serious, 

 had been carefully investigated and the number since that 

 date has been greatly increased. 



Historical concerning plant-disease prevention.^' ^'^^ 

 Though little could be done to devise rational methods of 

 combating plant diseases until their causes were known, a 

 very few rule-of-thumb, empirical ways of meeting them 

 had been suggested in very early days. As might be ex- 

 pected, many of the methods used were valueless. Thus 

 Parkinson early in the seventeenth century advocated the 

 use of vinegar to prevent canker on trees, and Forsyth in 

 1790 gave the following directions for making a mixture to 

 "cure disease, defects, and injuries of plants." ^ "Take one 

 bushel fresh cow dung, one half bushel lime rubbish from 

 old buildings, one half bushel wood ashes, one sixteenth 

 bushel pit or river sand. The last three are to be sifted fine 

 before they are mixed. Then work them well together with 

 a spade, and afterward with a wooden beater until the stuff 

 is very smooth, like fine plaster used for the ceilings of rooms." 

 Soapsuds or urine was used to make the composition of the 

 consistency of plaster or paint. After being applied it was 



