known to fail ; as also the American Early, 

 which always succeeds. 



The first system of degeneracy of the phmt 

 in Scotland appeared about the year 1780, when 

 the distemper, called the curl, first appeared in 

 the crop ; but it then occurred so rai'cly, that 

 vei-y little notice was taken of it ; but the evil 

 gradually and extensively increased, when, 

 about the years 1784-5, the whole crops of the 

 Lothians were seriously affected by it. A 

 remedy, however, was accidentally discovered, 

 b}' changing the seed from the high country ; 

 and this was and has been the only remedy for 

 the disease of the curl to the present day. At 

 this early period, the seed procured from the 

 high countiy had to be changed every three or 

 four years ; but it was found, as the cultivation 

 of the plant increased so did this disease ; and 

 from about the year 1820 up to the year 183.5, it 

 was customary to change the seed every other 

 year; and from 183-5 to the present year, 1845, 

 the whole seed had to be changed yearly, as it 

 was found that a new disease appeared in the 

 fields : the .seed only partially germinated — great 

 blanks or failures took place — and many farm- 

 ers almost lost their whole crops. This dis- 

 ease in the seed was called the wet and dry 

 rot ; and, in many instances, seed from all situa- 

 tions, high and low, has now also failed. These 

 two kinds of disease, which destroy germina- 

 tion, are variously accounted for. Some ascribe 

 the cause to maggots and flies ^vho feed upon 

 and destroy the seed-plants ; but this is a conse- 

 quence, and not a cause ; for maggots or flies 

 are only to be found on diseased or putrid vege- 

 tables : they riot and banquet on putrefaction : 

 it is their natural food, and there they are only 

 to be found. Plant, then, a sound Potato in a 

 good soil, and properly treated, it vi'ill find its 

 w^ay to the surface, and produce a good crop in 

 defiance of all maggots and flies. The seeds of 

 disease, then, must be in the constitution of the 

 plant. 



In examining a diseased Potato, which has, 

 as commonly called, blind eyes, and ■will not 

 germinate, it is plain diat there is canker on the 

 skin, and plague spots all over it. This, if 

 planted, will certainly be attacked by the mag- 

 gots and flies ; but the plant is in a state of de- 

 cay or puti'efaction — in fact, a caput mortuum — 

 and it properly belongs to the flies and mag- 

 gots by right of inheritance. The great object 

 to be attained, then, is, to plant sound seed, and 

 the maggots and flies will not relish it. As the 

 crops on the high lands arc early checked by 

 frost, and the tops or haulm soon destroyed, they 

 do not fully ripen ; and this circumstance has 

 induced farmers in the low distiicts to take up 

 their crops for seed in a green or unripe state, 

 in order to imitate tlie operations of nature on 

 the hill grounds ; but this plan has also failed. 

 Seed has been often raised from the apple, but 

 in two or three years it curls and degenerates. 



It is now generally allowed, and the idea long 

 entertained, that it is quite impo-ssible to raise 

 seed Potatoes ^vithout being affected with curl 

 in a low situation, or in a high temperature fi-ee 

 of degeneracy or curl ; but at an altitude of 400 

 feet, it then entirely disappears. Li this there 

 appears to be a veiy remarkable peculiarity in 

 the nature and constitution of the plant ; but in 

 looking to its origin, general historj', cultivation, 

 and general management in this country — its 

 success and failure — 1 have been led to a far 

 different conclusion. Indeed, from what I have 

 already stated, it must clearly appear to every 

 '(104) 



one, that there can be only one cause for the 

 failure of the plant, viz., over-cultivation. The 

 crop too often repeated on the same soil, and 

 too much stimulus applied to the plant, has 

 ■^veakencd or desti-oyed its vital energies, and 

 rendered it incapable of reproduction. In the 

 cultivation and general management of the 

 plant, we have entirely lost sight of nature, 

 which always follows the moderate or middle 

 course ; and, by a long train of mismanage- 

 ment, we have nearly lost this most valuable 

 root ; and if we shall persi.st much longer in 

 followmg the present unnatural and inconsider- 

 ate course of treating it, we shall certainlj- lose 

 it. Who can contemplate a luxuriant crop of 

 growing Potatoes in full bloom, but must reflect 

 on the immense stimulus applied to produce 

 such a mass of stem, fohage, and blos.som, and, 

 at the same time, hoNv much the roots or tubers 

 must be enfeebled and exhausted in producing 

 it 1 The first practical experience of failure 

 which I met with on my own farm struck me 

 most forcibly. lu the year 1837, I had a small 

 quantity of Potatoes for seed, which I had re- 

 ceived from the high grounds (the farm of Bon- 

 ally, in the high part of the parish of Colinton). 

 I thought them vei-y fine ; and having selected 

 the b8.st for seed, I manured the ground heavily 

 in the drill with the richest and best dung on 

 the fai-m, in order to have as many as possible 

 for planting the succeeding year. The extent 

 of gi-ound was about an acre, and I certainly 

 obtamed an excellent crop ; but as I never 

 planted a u-holc field, in the same way without 

 some variation, hy way of experiment, (a hint 

 here that will not be lost on the observant reader,) 

 I planted a few drills of similar seed next to them, 

 very moderately manured, and at the time of 

 taking up the crop, this acre was still green in 

 the tops, and we commenced to take up the 

 crop at the opposite side of the field, making 

 them the last to be taken up. The few drills 

 already mentioned were pitted on the end of a 

 pit not meant for seed, and the produce of the 

 acre was pitted by themselves. Next season I 

 planted the greater part of the produce of the 

 acre in the ordinary way, and lost one-third of 

 the crop. I also planted tlie produce of the few 

 drills in the ordinary ■way, and had a little curl, 

 but not a single blank. I was verj- particular 

 in all the operations of pitting and cutting, and 

 I am quite sure that the seed was not injured 

 in that way. 



I come now to state an instance, and one of 

 many that can be adduced, whiqli most clearly 

 and satisfactorily supports my assertion, viz., 

 that a heavy crop, grown in any situation or 

 soil, ■will always be found to produce, in a cer- 

 tain degree, degenerate and tainted seed. The 

 following is a letter I latelj; received from Mr. 

 Cunninghame, tenant, Harlaw, in the parish of 

 Cume. This farm is situated near the foot of 

 the Pentland Hills, at a;n elevation of more than 

 500 feet above the level of the sea. The follow- 

 ing is a copy of Mr. Cunninghame's letter : — ■ 

 " Harlaw, May 5, 1845. 



" My dear Sir : The new land in the Bog- 

 park was never in crop in my rememlirance, 

 either white crop or green. I drained the land 

 every furrow : they were old round-about ridges. 

 I plowed the land, and part of it I sowed with 

 oats, and haiTowed the Potato land along with 

 \vhat was intended for oats. In the Spring of 

 last year — about the end of April, the 20th or 

 24th of the month — I employed two men to 

 plant them, and put them in ■with the spade : 



