2£6 
Methods of Preventing and Checlcinrj 
From experiments before alluded to in otlier couutrieSj 
sulphate of copper solutions, mixtures, and powders have been 
proved to prevent and check the action of the potato fungus 
(PJb]lto])ldhora infest an s) . 
These have been most successfully used in the form of a 
hmiiUie Jyordelaise, for which prescriptions have been given above. 
This should be put on as a preventive from the 15th to the 25th 
of June, at from 140 to 150 gallons per acre, and again four weeks 
or so later, especially if heavy rains have fallen. If it has not 
been put on early as a preventive, a dressing should be given 
directly the first signs of disease show upon the leaves. For 
the French experiments, conducted by M. Girard, the bouillie 
was made of 20 lb. of sulphate of copper and 10 lb. of lime to 
100 gallons of water, which is rather weaker than the bouillie 
used for the vine mildew {Peronospora viticola). M. Peter- 
mann employed a bouillie of about the same strength in his 
Belgian experiments at Gembloux, but put on 220 gallons per 
acre. 
M. Thienpont used a bouillie of about 16 lb. of sulphate of 
copper and G lb. of lime to 100 gallons of water at Etichove in 
East Flanders. M. Petermann made trials also with sulphate 
of iron, applying it as a bouillie composed of 20 lb. of sulphate 
of iron and 10 lb. of lime to 100 gallons of water, and putting 
on 220 gallons per acre. M. Petermann considered this as 
efficacious as the copper bouillie, and much cheaper. 
Besides the Skawinski powder, the Podechard powder may 
be employed. To make this 11 lb. of lime are slaked in 2 gal- 
lons of water and 22 lb. of sulphate of copper are dissolved 
in 44 gallons of boiling water. After this is cooled, it is mixed 
with the lime and water. This is put over 220 lb. of unslal^ed 
lime, which it slakes, and with which it is incorporated. From 
20 to 30 lb. are usually put on per acre with the soufflet 
(Fig. G). 
The bouillie hqrdelaise and other liquid applications can be 
put on with the Eclair and other " Knapsack " machines, also 
with the Strawsonizer, which, however, requires to be set upon 
higher wheels for use among potato plants when they are high.' 
This machine will distribute the sulphate of copper powders 
equally well, but it must be remarked that these have been 
found by vine cultivators not nearly so effectual as the bouillies 
and other liquid forms, though the latter are more costly and 
more difficult to apply. 
' I am informed that a specidl machine could be made for potato plants 
wlien high. 
