72 The Potato. 



sulphur carefully raked into the earth underneath its branches. 

 The remainder of the larvae, fed exclusively on lettuce-leaves, were 

 not affected in any way. If these results be correct — and they 

 were seen by so many persons almost continuously, that any 

 eiTor must have been detected — they demand earnest and imme- 

 diate attention ; for they point out to the commercial and manu- 

 facturing world the reason of the less abundant supply of silk, 

 the cause and the remedy. It was observed, that the disease 

 nhoays appeared first on the leaves or stalk of tJie Japan lilies 

 (Liliurn lancifolium), and twenty-one days after its appearance 

 there it will be found aifectins: the potato. 



V, Do manures in any xcay affect the propagation of the dis- 

 ease ? and, if answered in the affirmative, woidd the use or employ- 

 ment (f any chemical ayent alter, chech, or remove the disease ^ 

 — In 1840, 1847, 1848, 1849,1850, five consecutive years, assist- 

 ance in answering these queries was oljtained from Aylcshury 

 Common, a tenacious clay soil resting on large water-worn 

 pebbles mostly of a silicious character, Mr. Westlake then 

 occupying this cold and tenacious clay estate ; from Dartmoor., 

 a purely granitic soil 1100 feet above the sea, by Mr. John 

 Hamlyn, then iny tenant ; afterwards, by the kind introduction 

 of the Rev. M. Lowndes, from nearly the centre of Dartmoor, by 

 Mr. Barter, of Baredown, about 1260 feet above the level of the 

 sea ; from Thorverton, on the new red sandstone, from Mr. H. 

 Lowcock, of lladdon Barton, aided most materially by the care 

 and assistance of Mr. Louis Reynolds, his able manager and 

 assistant, to whom I feel deeply obliged ; from Bishopsteiynton , 

 on the greensand formation, by Mr. Grylls, an attentive observer ; 

 from Moidton, by Mr. Cann. Also from many other places, 

 which if quoted here would extend this paper beyond any 

 reasonable bounds ; the result being, that on the cold and 

 tenacious clay, on the granitic soil, on the new red sand- 

 stone, on the greensand formation, on the limestone, and on 

 the clay-slate (locally called, shillity land), the reply uniformly 

 was that farmyard manure was prejudicial, and powerfully con- 

 tributed to the ravages of the disease. Guano appeared to be 

 equally bad. Wood-ashes appeared to be more favourable, as 

 did tanner s bark and Iteath ashes. Fern ashes caused some dis- 

 appointment, for, containing so large a proportion of silica, it 

 did not manifest any superiority over the other ashes. All, how- 

 C!ver, expressed a very decided opinion as to tlie yreat superiority 

 of lime a ral salt as the best potato manure. 



I shall pass over the numerous experiments made to investi- 

 gate the action of manures under my own especial observation, 

 and shall merely state the results : — Farmyard manure, rotten, or 

 fresh ; gas lime ; leather shreds ; gas water, with sulphuric acid ; 



