THE REAL CAUSE OF POTATO RO L\ AND THE BEST 

 MEANS OF PREVENTING IT. 



BY EDWARD MASON, OP DETROIT. 



That the potato rot has been the cause of a great deal of calamity to 

 the human race, is a fact too evident to be contradicted. In those parts 

 of Europe where the potato formed the principal food of the poor, its 

 sudden failure left them without any means of support, and famine and 

 pestilence wasted the miserable population. On the banks of the Rhine 

 and the Shannon, the grass now grows over many an humble grave, in 

 ■which sleep the victiriis of the potato rot. 



Although it is not likely that the inhabitants of the United States 

 will ever be compelled to resort to the potato as their principal food, 

 still the cultivation of this valuable root will always be a matter of the 

 greatest importance; and every method of preserving it should be care- 

 fully tried. 



Every physician will inform us, that in order to eflect a cure, it is es- 

 sentially necessary to understand the nature of the disease; and in pre- 

 venting the ravages of the potato rot, it is necessary that wo should un- 

 derstand the nature of that malady. 



The potato disease is certainly atmospheric, and generally makes its 

 appearance after lightning. I have frequently seen marks of it on the 

 leaves of the ash, the tender shoots of the Cauadian poplar, and on the 

 young branches of the hawthorn, sometime previous to its appearance 

 on the potato. Its attacks on the potato plaut are first visible on liie 

 uppermost leaves, and always on the backs of the leaves, in those pla- 

 ces where the lateral branches form an angle with the mid rib or leaf 

 stem. The leaves of the potato, like those of other plants, close up at 

 night, so that the backs of the leaves are the parts presented to the ac 



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