Report on Prevention and Cure of‘‘ Potoio Disease.” 763 
A slight lengthening of the tube carrying the nozzle for spraying was 
found desirable in order to distribute the dressing well on the 
underside of the leaves of the plant. The bouillie was made as 
before, by roughly pounding the sulphate of copper crystals, placing 
them in a bag suspended in a wooden tub containing water, slaking 
the lime with water, and, when cool, pouring it stirred up in water 
into the sulphate of copper solution, a sieve being interposed 
to hold back any lumps, stones, &c., which might be in it and so 
tend to block up the' spraying machine. By having the materuxls 
quite cool when mixed, and by keeping the liquid constantly stirred 
duiing the mixing, no difiBculty was experienced in getting the 
blight-blue colour characteristic of properly made bouillie, as well as 
the rapid settling down of a whitish-blue deposit which left above it 
a quite clear, colourless liquid, containing no copper, the latter 
being entirely thrown down in the deposit. 
The different varieties of potato experimented on were : — 
(n) Early varieties . “ Beauty of Hebron ” (Kent and Pembroke). 
“ Myatt’s ” (Lincolnshire). 
(6) Medium . . . “ Snowdrop ” (Kent and Lincolnshire). 
“ "White Elephant ” (Beds and Pembroke). 
“Abundance’’ (Cheshire). 
(e) Late . . . “ Magnum Bonnm ” (Kent, Lincolnshire, Devon). 
“ Imperator ” (Bods). 
“ Bruce ” (Devon and Cheshire). 
“Irish Flounder” (Pembroke). 
The above distinctions are, of course, not absolute ones, a crop 
being considered “ medium ” in one district whilst it may be 
relatively “ late ” in another. Thus, the “ Magnum ” is considered a 
“ medium” crop in Devon, relatively to the “later” crop “Bruce,” 
although it generally ranks as a “late ” or “ main ” crop. 
Profiting by the experience furnished last year, the intention was 
to apply the first or “ early ” application of the bouillie to the A plots 
about a fortnight before the time at which experience told the 
experimenters that the “disease” might be expected to appear on 
each crop. 
Dir. Giles’s visits were arranged in accordance with this plan, 
and inquiries Avere made from time to time as to the progress of the 
crops and the likelihood of the appearing of disease. 
In every case the A plots were sprayed Avell in advance of the 
outbreak of disease, and the B plots as soon after notification of the 
appearance of disease as was possible, Mr. Giles at once proceeding 
to the spot on receipt of telegraphic notice. 
Two of the experimenters [Mr. Scott and Dir. J. T. Smith (for 
Lord Egerton)] varied the inquiry and increased its interest by 
dividing the A plots (early dressing) into two halves, giving one half 
a single application only of the dressing, and two applications to the 
other half. At Diessrs. DIalden’s the A plots of the “ "White Ele- 
phant ” were dressed once only, but the “Imperator” twice. At 
Dir, Healey’s the A’s were all dressed twice, but only once at Mr. 
