THE POTATO ROT. 465 



Rate per cent. 

 Substances employed. diseased^ 



33. Sets sprinkled with quicklime 17-27' 



34. Soot 16-21 



35. Oilcake (half row) 9-23 



36. Notliiiig (half row) 11-52 



37. Powdered cliarcoal (half row) 12-43 



38. Nothing (half row) 14-71 



39. Sets dipped in boiling -water 7-39 



40. Sets dipped in lime and dung-water. .11-90 



41. Do. do. 15-02 



42. Do. do. 8-94 



43. Planted alternately with beans 11-90 



44. Crushed oil-seed (half row) 10-51 



Rate per cent. 

 Substances employed. diseased. 



45. Nothing (half row) ^ 5-74 



46. Powdered oil-cake (half row) 3-48 



47. Nothing (half row) 8-30 



48. Shaded by Indian corn 14-12 



Average of all the rows to which noth- 

 ing was applied 1 8-H 



49. Potash, salt, fat and water 5303 



50. Do. do 1-38 



51. Do. do. 0-0 



52. Sulphuric acid to 12-28 



53. Sulphate of magnesia to 4-19 



54. Chloride of lime 0-23 to 4-27 



In some cases where sulphuric acid was used, the disease disappeared, but the crop -was 

 nearly destroyed. 



The most remarkable result was that of the application of a soap jelly, a mixture of pot- 

 ash, fat, salt and water, an American remedy. When applied to plants set whole in hills, 

 layered and earthed up repeatedly, the potatoes treated with this mixture were in some 

 cases free from disease, but in other cases the per centage of tainted tubers amounted to as- 

 much as 24-44, and when the// were not earthed up to even 53-03, or to an average of 21-32 

 in 30 experiments. It is therefore a question whether the advantage which in some cases 

 appeared to belong to the soap jelly was not in reality attributable to the mode of treatment. 



Seedlings, concerning which so much obviously unfounded expectation was entertained, 

 proved no more exempt from disease than old and long-cultivated varieties, as is shown in 

 the following Table : 



Rate per cent, 

 diseased. 



5. Seed from Poland, sown in gentle heat 

 May 24 ; planted out .Tune 16 13-94 



6. Seed from Poland, sown in the open 

 ground, May 24 47-36 



7. Ditto 72-82 



8. Ditto 47 01 



9. Seed from Maldon, Essex, sown in the 

 open ground, March 18 29-44 



Rate per cent, 

 diseased. 



German seed from Baden, sown in gen- 

 tle heat April 3 ; planted out April 

 30 9-64 



Ditto 15-84 



Seed from Mussooree, sown in the open 

 ground, March 18 25-00 



Seed from Mussooree, sown in gentle 

 heat April 3 ; planted out April 30.. 18-42 



Neither did the wild potato escape ; on the contrary, a perfectly wild form of the root, 

 fresh from its native mountains, is reported to have " exhibited the characteristic blotches in 

 a worse degree than any other sort in the garden." In short, the conclusion which has been 

 arrived at from the Horticultural Society's experiments is " that there is no known jireven- 

 tive of the disease ; that neither renewal by seed, nor inti-oduction from foreign countries, nor 

 treatment in the earth, aflbrd any guaranty agamst its attacks ; and that its progress cannot, 

 in the present state of our knowledge, be resisted with such success as to justify the recom- 

 mendation to the public of any of the 4'emedies hitherto propo.sed." 



These facts surely point more strongly than any argument to the impolicy of encouraging 

 the cultivation of the potato, except as an aid to human svibsistence, along with other and 

 more hardy varieties of food. Its very productiveness when healthy evidently leads to the- 

 most awful social calamities in the event of failure ; and if the cultivation of the plant is 

 persevered in, Europe can expect no respite from those dreadful visitations which we are 

 told by the very able and well-infonned author of the " Irish Crisis," in the Edinburgh Re- 

 view, has produced no fewer than seven partial or general famines in Ireland during 26 

 years, viz., in 1822, 1835-6-7-9, and 1845-C, or one in every three or four years. If the 

 richest country in the world would sink under such a series of disasters, what must be the 

 inevitable condition of the poorest ? 



We repeat, then, that the cultivation of the potato, by the poor, for their main subsist- 

 ence, should be discouraged in all possible ways ; and that, on the other hand, the en- 

 couragement of other articles of food should be the first and most serious object of all 

 humane persons throughout the United Kingdom ; for there is not the slightest security 

 that the present disease, when it shall have disappeared, will not be succeeded by one 

 quite as formidable. 



[We may thank Providence that with our Indian corn there is no danger 

 that roots should ever be the basis of popular subsistence in our country. How 

 dreadful would it be to have the whole nation, as in Ireland, live in habitual 

 and constant dependence on such a diet, with nothing to fall back upon in case 

 of disease and scarcity. But even that is not all. It is impossible for a nation 

 that looks, for its subsistence, to one such single and simple culture and prepara- 

 tion, of its food to advance in civilization and the arts. The main impulse that 



(865) 30 



