SOME PESTS OF OHIO SHEEP 79 



plenishing the dip in the vat largely a matter of guesswork. In 

 order to obtain a homogeneous solution of the diluted dip, it is nec- 

 essary to use soft water, and to be sure that the undiluted dip is 

 homogeneous in character (before using it) as occasionally, espec- 

 ially in cold weather, a separation of the coal-tar oils and other con- 

 stituents of the dip may occur. 



CRESOL DIPS 



The cresol dips are made of cresylic acid and soap and are sold 

 under various trade names. The term cresylic acid is usually ap- 

 plied to those cresols and phenols, derived from coal-tar, which boil 

 between 185 degrees C. (365 degrees F.) and 250 degrees C. (482 

 degrees F.). To be effective, these dips should when diluted con- 

 tain one-half of 1 percent of cresylic acid. At present there is no 

 field test for the cresol dips so that renewal in the vat is, as with the 

 coal-tar creosote dips, largely a matter of guess work. 



Soft water is essential to the effectiveness of these dips. In 

 fact it is advisable to test the water that is to be used in order to 

 avoid injury to the animals. This may be done by first thoroughly 

 mixing a small portion of the dip with water in a bottle in the pro- 

 portions recommended for dipping. After an interval of an hour if 

 oil globules appear at the top or bottom of the solution then the 

 water is unfit for use. 



NICOTINE DIPS 



Nicotine dips are sold under various trade names. In using 

 this type of dip, as with all other commercial dips, the directions of 

 the manufacturers should be followed. By means of a field test de- 

 signed by one of the large manufacturers the percentage of nicotine 

 may be ascertained at any time during the dipping operations. 



LIME- SULPHUR DIPS 



The home-boiled lime-sulphur dip is made in the following pro- 

 portions : 



Lime, unslacked 8 pounds 



Or lime, commercial hydrated 11 pounds 



Flowers of sulphur 24 pounds 



Water 100 gallons 



The lime and the sulphur and about 30 gallons of water are 

 boiled together for 1 hour or until all the sulphur disappears from 

 the surface of the liquid. This is done in a kettle over fire or in a 

 barrel or other suitable tank by means of steam. The dip should 

 be siphoned or poured off carefully, and strained, then diluted to 

 100 gallons and is then ready for use. It is necessary that suffi- 

 cient lime be used to properly "cut" the sulphur. On the other 

 hand an excess of lime in the dip will tend to injure the sheep and 

 wool. 



