188 



GENESEE PARMER. 



Dec. 1845 



THE POTATOE DISEASE. 



Our files of foreifjn papers are nearly filled with 

 accounts and speculations, relating to the potatoe 

 blight, or disease. The following correspondence 

 between Lord Portman, President of the Royal Ag- 

 ricultural Society, and William Herapath, Esq.. an 

 eminent analytical chemist of Bristol, taken from 

 the Bristol Mercury of September *JOth, contains 

 the most useful suggestion of any articles which 

 have met our eye: 



"Bryanston, Sept. 13, 1845. 



"Sir, — I observe in the news papers that you 

 have directed your attention to the potatoe disease, 

 and have advised as to the use of the starch, &ic. 

 As I am specially bound, during this year of my 

 holding the office of President of the Royal Agri- 

 cultural Society of England, to promote inquiry 

 and to notify observations ou subjects relative 

 to the produce of the soil, I trouble you with 

 this letter, and ask if any method has occur- 

 red to you by which the potatoe may be preserved 

 for the planting of 1846? I have found that po- 

 tatoes apparently sound and free from the disease, 

 though in a field or garden which has been partially 

 diseased, have, after being stored away, shown 

 signs of the disease and have rotted off; and I fear 

 that the greatest quantity of the potatoes will thus 

 perish, and so continue the distress of the poor into 

 another season. I have directed some potatoes to 

 be stored in slaked lime, in the hope that it may pre- 

 Berve them, but have, of course, yet had no time to 

 udo-e of the effect. I therefore ask for your opin- 

 ion, as one of our most eminent chemists, upon this 

 point, and would ask leave to make known your re- 

 ply, if you are able to offer an opinion sufficiently 

 explicit to be useful. 



•' I remain your obedient servant, 



*' Portman. 



"Wm. Herapath, Esq." 



"to lord portman, prbsident or the agricul- 

 tural SOCIETY. 



''Bristol, Sept. IT, 1845. 

 "My Lord, — In reply to your letter of the 13th 

 inst., I must say that I do not think it would be ei- 

 ther safe or prudent to depend upon the infected po- 

 tatoes of the present season as seed for the next 

 year ; as, in all instances, I have found the diseased 

 parts to extend when the potatoes are kept in a damp 

 situation ; I should therefore expect that if any dis- 

 eased seed was kept bo dry as not to rot before set- 

 ting time, yet upon being planted and left in the 

 damp soil, the rotting process would then begin, 

 and the hopes of the husbandman be disappointed. 

 I have no doubt that some potatoes, apparently 

 sound, have (as stated by your lordship) been found 

 to be affected after stowing away ; but I do not 

 consider this to have been an origination of it, but 

 merely that which was unnoticed when dug has be- 

 come apparent after storing. When a potatoe is 

 first affected, the diseased parts are scarcely visible ; 

 but upon keeping it in a dry place, the spots soon 

 become dark, and consequentl}' more apparent, but 

 the spots GO not extend : if, however, the tuber has 

 been kept in a damp place, the spots not only ex- 

 tend rapidly over the surfcice, but penetrate into the 

 interior, and in a short time it will be completely 

 rotten. As far as the slaked lime, which you have 

 used in your potatoe stores, has a tendency to pre- 

 vent the tubers from touching each other, or, by 

 its power of absorbing water, of keeping them dry, 



it will answer a good end : but it must not be ex- 

 pected to have any chemical effect upon the diseased 

 parts or their juices. Anything which, like dry saw- 

 dust or sand, would prevent contact, would prevent 

 the propagation from one tuber to another ; and any 

 substance capable of absorbing the moisture of the 

 air in which the pototo is stored, would prevent the 

 extension of the disease in each diseased root. Our 

 best microscopists and cryptogamists are divided in 

 opinion as to whether the cause of the calamity is a 

 fungus or not. After all the examination I have 

 given to the subject, and a careful review of all the 

 evidence brought before me on the two sides, I be- 

 lieve that it is ; and I am daily confirmed in the 

 opinion originally expressed, that the only advanta- 

 geous way of treating the diseased potatoes is to ob- 

 tain from them, by rasping and washing, the starch 

 which they contain — by which process all their nu- 

 triment can be retained ; and if it is well dried it 

 will keep for any length of time. The operations 

 can be performed in the cottage or manufactory alike, 

 as no apparatus beyond a tin rasp (a nutmeg grater,) 

 a tub, and clean water are required ; and I have as- 

 certained that however far the disease might have 

 extended, even if the root is rotton, yet the starch 

 can be separated, and in a state fit to be eaten, if it 

 shall be well washed, as all the bad parts come 

 away with the water, while the great weight of the 

 starch carries it to the bottom of the vessel. If it 

 is required that the fecula should have all the quali- 

 ties of the best foreign arrow-root, it is only neces- 

 sary to wash it last in water containing a little chlo- 

 rine, when it has unrivalled colour and quality, and 

 this I can speak of practically, having made many 

 tons of the article. I will only add, that an opin- 

 ion has been circulated that the disease is owing to 

 the introduction of guano as a manure ; this I feel 

 no hesitation in contradicting, as I have seen it in 

 situations where no guano has been used, and where 

 every other variety of manure has been resorted to. 

 " I am your lordship's most obedient servant, 



"WILLIAM HERAPATH." 



Particular care should be taken to keep the tubers 

 dry and in the dark. The following is a concise ac- 

 count of the potatoe crop in Holland which we think 

 will be read with interest: 



"The governor of the province of North Holland 

 and the agricultural committee of Groningen have 

 just published official reports respecting the murrain 

 amongst the potatoes. In the circular of the above 

 functionary, it is stated that potatoes when they 

 begin to be inflamed and are only slightly infected, 

 should be carefully spread out, and dried in a dark 

 place ; this (it is said) will harden the germ of the 

 disease, and arrest its progress. It is recommen- 

 ded not to throw away the potatoes which are more 

 deeply injured, but to extract the nutritious portions 

 from them. The inhabitants of North Holland are 

 also recommended by the governor to try to raise 

 winter potatoes in gardens and on sandy soils, to 

 plant them a foot deep in September or October, and 

 to cover the ground with straw or leaves as soon as 

 the frosty weather sets in. The official report of 

 the Groningen Agricultural Committee is a much 

 more lengthy and important one, and enters at once 

 into the causes and character of the disease, and 

 proposes some remedies. The malady is partly as- 

 cribed in the report to the heavy rains of the sum- 

 mer of 1844, and to the wot weather which pre- 

 vailed just at the time the tubercle seods were form- 



