The Potato. 71 



as the identify of the disease M'hich affects the vine and potato 

 was thus established, the brickwork of the walls was washed with 

 2 lbs. of flour of sulphur, mixed (by g'uess) with 5 lbs. of lime 

 and half a pail of water; and being' well stirred up, the front wall 

 under the sfielf was washed once, the back wall twice with this 

 mixture. The effect was immediately to arrest the disease and 

 prevent it from spreading. A larger vinery, 32 feet by 20, and 

 filled with an abundant crop of grapes, was treated in like 

 manner, and with similar success ; and I may remark en passant 

 that both houses have continued entirely free from disease to 

 this day. 



It will be evident from the preceding pages that a damp 

 foggy atmosphere is peculiarly conducive to the propagation 

 of the disease, whilst a dry atmosphere arrests its diffusion. 

 Mr. Lowco(k, then a tenant on Raddon Court, Barton, the pro- 

 perty of J. Hippisley, Esq., near Crediton, offered me his assist- 

 ance in testing these views on a large scale ; and his wishes 

 were most zealously seconded by his very able and intelligent 

 assistant, Mr. Louis Reynolds. The result of numerous experi- 

 ments proved, that in tlie bottoms or usually foggy ground the 

 disease invariably appears early and is very severe ; that a 

 higher elevation escapes to a later period and is less severely 

 visited ; whilst higher still and near the top of the hill potatoes 

 frequently escape altogether. 



Many other plants were similarly affected. It has been 

 noticed before that the visitation of the disease was first ob- 

 served on the apple and sloe ; the ash, maple, and viulherry 

 followed ; and then the elm, so extensively, that in the autumn 

 of 1855, in this land of elm, no leaf could be discovered without 

 the fatal blackened spot. Nor has the disease been confined in 

 its ravages to this locality; the mulberry especially was early 

 and extensively diseased, and the leaf being of considerable size 

 and firm texture afforded very good opportunities for examining 

 the spread and progress of tlie disease. Whilst these examina- 

 tions were in progress, I was informed by a young friend that 

 several of the silkworms fed on the leaves of a mulberry tree had 

 turned stiff, black, and died, when of large size and just about to 

 spin. In 1854, 1855, and 1856 I obtained papers of eggs from 

 various places, which were hatched at very different times, but 

 with one result. The larvfe were placed in trays and carefully 

 attended to. All of them without an exception fed on the leaves, 

 not then diseased, but afterwards severely affected, of a mulberry 

 tree, died ; all fed on the leaves of a mulberry, not then nor ajter- 

 wards affected, lived and spun icell, but the cocoons were unusually 

 small, and it ought to be observed that this mulberry tree has 

 had every year in the month of Mav several pounds of flour ol 



