make known your replj', if yoa are able to offer 

 an opiniou sufficiently explicit to be useful. 

 " I remain your obedient servant, 

 " War. Hkkapath, Esq." " PORTMAN. 



" To Jjord Portman, President ofthi Agr. Sociefy. 

 " Bbistol, Sept. 17, 1845. 

 "My Lord: — In reply to your letter of the 

 13th inst., I must say tbat I do not think it 

 wonld be either safe or prudent to depend upon 

 the infected potatoes of the present season as 

 seed for the next year ; as, in aU instances, I 

 have found the diseased parts to extend when 

 the potatoes are kept in a damp situation; I 

 should therefore expect that if anj' diseased seed 

 was kept so drj" as not to rot before setting 

 time, yet upon being planted and left in the damp 

 soil, the rotting process would then begin, and 

 the hopes of tlie husbandman be disappointed. 

 I have no doubt that some potatoes, apparently 

 sound, have (as stated by your lordship) been 

 found to be atFected after stowing away ; but I 

 do not consider this to have been an origination 

 of it, but merely that which w^as unnoticed 

 when dug has become apparent after storing. 

 When a potato is first allected, the diseased 

 parts are scarcely visible ; but upon keeping it 

 in a dry place, the spots soon become dark, and 

 consequently more apparent, but the spots do 

 not extend ; if, however, the tuber has been 

 kept in a damp place, the spots not only extend 

 rapidly over the surface, but penetrate into tlie 

 interior, and in a short time it will be completely 

 rotten. As far as the slaked lime, which you 

 have used in your potato stores, has a tendency 

 to prevent the tubers from touching each other, 

 or, by its power of absorbing water, of keeping 

 them diy, it will answer a good end : but it must 

 not be expected to have any chemical effect up- 

 on the diseased parts or thek juices. Anything 

 which, Uke diy saw-dust or sand, would prevent 

 contact, would prevent the propagation from 

 one tuber to another ; and any substance capa- 

 ble of absorbing the moisture of die air in which 

 the potato is stored, would prevent the exten- 

 sion of the disease in each diseased root. Our 

 best microscopists and crj-ptogamists are di\-ided 

 in opinion as to whether the cause of tlie calam- 

 ity is a fungus or not After all the examina- 

 tion I have piven to the subject, and a careful 

 review of all the evidence brought before me on 

 the two sides. I believe that it is ; and I am daily 

 confirmed in the opinion originally expressed, 

 that the only advantageous way of treating the 

 diseased potatoes is to obtain from them, by 

 rasping and washing, the starch which they 

 contain — by which process all their nutriment 

 can be retained ; and if it is w-ell 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 nut- 

 meg grater.) a tub, and clean \vater are requi- 

 red ; and I have ascertained that however far 

 the disease might have extended, even if the 

 root is rotten, jet the starch can be separated, 

 and in a state fit to be eaten, if it shall be well 

 ■washed, as all the bad piarts come av/ay with 

 the water, while the great weight of the starch 

 carries it to the bottom of the vessel. If it is re- 

 quired that the fecula should have all the quali- 

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

 cessary to wash it last in water containing a lit- 

 tle chlorine, when it has unrivaled color and 

 quality, and this I can speak of practically, hav- 

 ing made many tons of the article. I will only 

 add. that an opinion has been circulated that the 



disease is owing to the introduction of guano as 

 a manure ; this I feel no hesitation in contradict- 

 ing, as I have seen it in situations where no gu- 

 ano has been used, and whei-e every odier vari- 

 ety of manure has been resorted to. 



" 1 am yom- lordship'.s most obedient servant. 

 " WILLIAM HERAPATH." 



The Governor of the Province of iSTorth Hol- 

 land and tlie agricultural committee of Groniu- 

 genhave just published official reports rospecting 

 the murrain amongst the potatoes. In the cir- 

 cular of the above functionary, it is stated tbat 

 potatoes v.hen they begin to be inflamed and 

 ai'e 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 progi'ess. It is recommended not to 

 throw away the potatoes which are more deep- 

 ly 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 vs ith straw or 

 leaves as soon as tlie frosty vi-eather sets in. The 

 official report of the Groningen Agricultural 

 Committee is a much more lengthy and import- 

 ant one, and enters at once into the cau.=es and 

 character of the disease, and proposes some re- 

 medies. The malady is partly ascribed in the 

 report, to the heavy rains of the summer of 1844, 

 and to the wet weather which prevailed just at 

 the time the tubercle seeds were foraied, and 

 partly to the carelessness of the agriculturists in 

 keeping the potatoes intended for planting per- 

 fectly dry. It is thought too that tlie excessive 

 cold of last March proved vei-y injurious. The 

 more direct causes are thus enumerated : — 1. 

 The too rapid growth of the plants this year. 

 2. The excessive heat which prevailed in the 

 first part of the summer of the present year, be- 

 ing, on the 13th of June, 87 deg. of Fahrenheit ; 

 on the 3d of July, 87^ deg. ; and on the 7th of 

 the same month 91 1 deg. On these days seve- 

 ral persons fell dead in the fields. 3: The rain 

 which feU at intervals, and which subjected the 

 plants, as it were, to the action of warm water. 

 4. The cold and moist temperature which suc- 

 ceeded, from the 15th of July to the end of Au- 

 gust : and, 5. the existence in several places, on 

 July 21 and 22, of an extraordinary fog. which 

 emitted a disagreeable odor. The agricultural 

 committee attach much importance to this mias- 

 ma; for they hasten to state that the malady al- 

 most immediatelj' afterwards was manifested, 

 and they add that they are not by any means 

 disposed to place this fog amongst the improbar 

 ble causes fo/iic aarschij nlijlcheden j of the com- 

 plaint in question. In the province of Gronin- 

 gen it was clearly ascertained that the infection 

 proceeded from "the leaves and the stalk to the 

 root, and that it was displayed bj- small stains 

 and by the existence of a species of mushroom 

 placed by some writers under the head, plusipo- 

 rum solani. No traces of these para.sites were 

 discovered in the stalks or the tubercles — a fact 

 which is set forth as a proof that the disease was 

 first propagated from the leaves, and conse- 

 quently that it differs essentiallj- from those 

 murrains which originate in the roots. " Wo 

 maintain," observe the committee, " that this 

 disease has probably existed before, more or 

 less, but that it is one which hitherto has not 

 been described by naturalists (maar eeiie hijde 

 nat unrkundisren, nvs onbeschrevene zkkkj. 



