64 JOHNSON & STOKES 
At the New Jersey Station, Professor Halsted com- 
pletely conquered scab with an application of 300 pounds of 
flowers of sulphur per acre scattered in the rows, while the 
same treatment at the Ohio Station was less successful. At 
the latter station benefit was found in the use of salt, kainit, 
sulphate of potash, etc. 
The various experiments and observations on potato scab 
and rot seem to indicate that scab flourishes best on a soil 
inclined to be alkaline, while rot is most prevalent on a soil 
inclined to be acid. The use of lime increases scab, while 
the use of kainit diminishes it. 
The best practice, therefore, under present knowledge, 
would be to use clean seed on new ground, avoiding fresh 
stable manure. Clean seed can be had by treating tubers 
with corrosive sublimate. This substance is dissolved to the 
amount of 2% ounces, in two gallons of hot water, and (after 
standing a day) diluted with water so as to make fifteen 
gallons. In this solution the uncut seed potatoes should be 
soaked for an hour and a half. All unplanted seed potatoes 
should be destroyed, as the corrosive sublimate is highly 
poisonous. 
The use of sulphur, as recommended by Professor Hal- 
sted, will prove entirely satisfactory in some soils. In others, 
the use of kainit or sulphate of potash or acid phosphate 
would no doubt be found preferable. 
Where soil is badly affected with disease germs, it is un- 
questionably better to seek a new field than to attempt to 
disinfect the old one. A rotation of crops will probably re- 
store diseased land to health more cheaply and more thor- 
oughly than any other process. 
P rofits. — Of potato profits it is not necessary to speak, 
except to remark that it costs but little more to produce 300 
bushels to the acre than 100 bushels. There can be no doubt 
whatever that it pays handsomely to spray potato vines with 
the Bordeaux mixture. 
