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vidual to assert that the blight is not atmospheric; and it is a fact that 

 it is caused by nitric acid, which is conveyed by rain and dews. 



I will now proceed to the second part of my undertaking, and de- 

 scribe the best method of preventing the rot, by such an alteration in the 

 cultivation and management of the potato as will suit the emergency. 



The potato blight appeared nearly at the same time in many differ- 

 ent parts of the world; it visited Europe and Asia, and some parts of 

 America, in 1845. Potatoes raised from seedlings, did not escape any 

 more than those raised from tubers. The produce of wild potatoes which 

 had been imported from the mountains of South America, did not es- 

 cape better than those kinds which had been acclimated in Europe, and. 

 North America. In fact, everything connected with the disease proves 

 that it is atmospheric, and our observation enables us to j^erceive that 

 it generally visits the crop in the latter end of July, or the beginning of 

 August, and the latter circumstance enables us to guard against it, ob- 

 serving the following rules: 



First — Select a well drained field for the intended crop, let it be fresh 

 from grass if possible, as new land is always best for raising potatoes; 

 take care that rain water cannot lodge in any part of it. 



Second — Do not allow the tubers to sprout in the roothouse, pit or 

 cellar, before planting ; get them into the earth before their strength is 

 exhausted by fruitless vegetation. 



Third — Be careful in selecting seed ; some kinds are hardy, and resist 

 the attacks of blight ; plant these in preference to all others. If sets or 

 cut seed are used, they should be prepared before the tubers have 

 sprouted, for if cut when in a growing state, the sets will bleed, that is, 

 loose much of their essential juice. 



Fourth — Do not plant potatoes in low, damp situations, for such lo- 

 calities are subject to fogs which sometimes contain the elements of 

 blight and mildew, and are also liable to receive and retain large quan- 

 tities of rain water, which at certain times contains ingredients hurtful 

 to the plants. 



Fifth — Take great care in the management of the manure intended 

 for the crop ; let it be carefully heaped in the fall or winter, and the 

 liquid manure carefully preserved. For the growth of potatoes manure 

 should be well rotted, and reduced nearly to a state of compost; by this 

 means the roots of the potatoes will at once receive nourishment, and 



