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gradually deteriorating, perhaps in proportion to extinction of humus 

 in the soil. The disease is generally unknown in new countries, when 

 planted in virgin soil, especially if common care is exercised in chang- 

 ing seed, and preventing heating &c., of the seed tubers, whether in 

 pit or cellar. 



LieLig has written a short, but very scientific treatise, on the origin 

 of the potato disease, from the deductions of which Dr. Klotzsch, of 

 Berlin, proposes for the preventing of the disease, " at a time when the 

 plants reach the height of 6 to 9 inches above the soil, we pinch off 

 the extreme points of the branches, or twigs, to the extent of half an 

 inch downwards, and repeat this on every branch, or twig, in the lOth 

 and 11th week; no matter at what time of the day." In our own 

 land, gypsum and salt mixed together, and scattered on the hills, have 

 been recommended as a prevention of the disease. 



Both the above plans may be in many cases efficacious. By cutting, 

 or plucking off the points of branches or twigs of annual plants, a new 

 growth is induced ; and by continuing the process, the plants may 

 grow for any length of time. This is well known to horticulturists, 

 who pinch off the blossom from annual flowers. . The use of gypsum 

 or plaster, is to induce moisture ; the attractive power of that mineral 

 being well known. Salt may be useful for the same end, but acting in 

 a different way. 



There can be no question but that the potato disease is chiefly pro- 

 duced from drought ; and anything that would counteract the aridity of 

 the atmosphere, and equalize the temperature of the soil, would have 

 the effect, if not of entirely eradicating, at least of modifying the dis- 

 ease. Nothing, it is conceived, would have a greater tendency to effect 

 so desirable a consummation, as a liberal mulching of the potato field, 

 immediately after planting. As the process of mulching, so very be- 

 neficial to orchards, may not be generally known, an accurate account 

 of the best mode is hereby subjoined, from the pen of the well known 

 Mr. -J. J. Thomas, of Macedon, New York : 



" ^Mulching, that is covering the soil with old straw, coarse litter, or 

 leaves, not less. than five or six inches thick: this keeps the top soil 

 throughout the hottest day, as moist as the dew of morning, and con- 

 sequently the under soil can never become dry. The moisture of the 

 soil is thus preserved in the most even manner — incomparably better 



