GRASSES OP IOWA. 259 



Potassium sulphide. — Potassium sulphide has proved effica- 

 cious. The method given by Swingle is as follows: " Dissolve 

 one and a half pounds of potassium sulphide in twenty-five 

 gallons of water in a wooden vessel (a tight barrel serves very 

 well for this purpose). The potassium sulphide should be of 

 the fused form, known as liver sulphur. This can be obtained 

 of any druggist for from 25 to 50 cents per pound, according 

 to the quantity purchased. It should be kept protected from 

 the air in a tight glass vessel until ready for use. The lumps 

 of potassium sulphide dissolve in a few minutes, making the 

 liquid a clear yellowish-brown color. After thoroughly stir- 

 ring, put into the solution about three bushels of oats and agi- 

 tate well to insure wetting every grain. The solution must not 

 only cover the grain, but must rise several inches above it, as 

 some of it is soaked up by the grain. Leave the oats in the 

 solution for twenty-four hours, stirring several times during 

 the day to make sure that every kernel is wett d, after which 

 spread out to dry. A number of experimenters have found 

 that soaking ihe se;d two hours in a 2 per cent solution (eight 

 pounds to fifty gallons) was nearly or quite as effective as the 

 longer treament. The grain should be stirred repeatedly to 

 insure thorough wetting. Seed thus treated is much easier to 

 dry than that soaked twenty-four hours. Probably this form 

 of treatment will prove the best. 



"la treating large quantities of seed a hogshead or wooden 

 tank might be used. The solution should be kept well covered 

 to keep the air from it, and should not be used more than three 

 times. In no case should metal be allowed to come in contact 

 with it. This treatment is thoroughly effective for loose smut 

 of oats, and is worthy of a trial for stinking smut of wheat. " 



Geres powder. — This substance is advertised as a preventive 

 of smuts, is, according to the analyses of Hollerung and other 

 German investigators, only crude potassium suphide sold under 

 another name and at a much higher price. 



Sar solution. — This consists chiefly of sodium sulphide and 

 as given by Swingle is prepared as follows; "Place fifteen 

 pounds of flowers of sulphur in a barrel, mix thoroughly with 

 one-half pound of finely-powdered resin, and stir well with 

 three quarts of water, which should make a thick paste. The 

 paste must not be thin and watery, nor so dry as to crumble to 

 powder when stirred. Then add ten pounds of caustic soda 



