POTATO DISEASE. 105 



placed in the cellar. One or two other questions remain which I 

 do not attempt to answer, as the facts implied in the questions, 

 might not be found to exist. 



That the Potato disease is as ancient as the potato itself there 

 can be no reasonable doubt. We have no exact observations as 

 to the occurrence of the potato fungus, (Peronospora) in the native 

 land of the tuber ; and the climate is such as to be on the whole 

 unfavorable to the development of the fungus, being elevated, airy 

 and of equable temperature ; nevertheless many accounts have 

 come to us, which indicate that the rot is by no means unknown 

 on the Cordilleran table-lands. The Jesuit Joseph Acosta observed 

 in Peru in 1571, that the tubers of the potato often spoiled in the 

 earth, during or after cold bad weather, from " blight or mildew," 

 Payen, in the Proceedings of the Paris Academy, mentions that ac- 

 cording to communications made by Mons. Goudot, a disease pre- 

 vailed in the Cordilleras, which if not identical with, had the 

 greatest resemblance to the tuber-rot of Europe and North America. 

 Boussingault sent to the Paris Academy in 1845 a letter from 

 Bogota, in which was stated that on the table-lands of that vicinity 

 the potato spoiled in moist situations every year, and in wet seasons 

 spoiled everywhere. 



Similar statements indicate that the disease was locally known 

 in Europe before 1845, Harting, in Holland, v. Martins in Bavaria, 

 and other trustworthy observers, saw, and describe the Peronospora 

 in 1845. In Alsace, a malady corresponding to the potato rot was 

 observed in 1816 ; the same happened in the neighborhood of Or- 

 leans, France, in 1829. Finally, in a treatise on the potato, written 

 by Ludwig in 1170, but 50 years after the field culture of this tuber 

 had become extensive in Germany, and ten years before its intro- 

 duction into France, occurs the description of a malady or " visible 

 blight," which attacked the tubers, and could be seen on paring 

 the potato, as a brown or black discoloration. It is thus probable 

 that the potato fungus was imported with the potato into Europe 

 and North America, and is the universally existing cause of the 

 disease. The epidemic form which it has assumed of late years, 

 is due to the wide-spread presence of the conditions favorable to 

 its rapid multiplication, and in no small degree to the fact that the 

 culture of the potato had been immensely extended for a number of 

 years previous to the appearance of the epidemic. 



