38 MEDICAL ENTOMOLOGY 



Industry as used against sheep scab, but the addition of sulphur 

 (16 pounds to the above formula) is recommended. 

 Examine a sample of tobacco decoction. 



b. Lime and sulphur form the active ingredients for a dip 

 used against scab mites of both sheep and cattle. When used 

 for scab in sheep the following formula is recommended: 24 Ibs. - 

 flowers of sulphur, 8 Ibs. of unslaked lime to 100 gallons of soft 

 water; when used for cattle scab or mange, the lime should be 

 increased to 12 Ibs. 



Examine a sample of lime sulphur solution. 



c. Cresol is a coal tar product of high cresylic acid content 

 (from 90% to 98%) and is ordinarily a straw-colored liquid. 

 Cresol is poisonous, and corrosive. In order to produce a 

 mechanical mixture with water, cresol is carefully mixed with lin- 

 seed oil or soap, and when prepared according to the U. S. Phar- 

 macopeia is known as " liquor cresolis compositus." As a disin- 

 fectant, it is useful diluted with water at from 2 to 4%. It is also 

 used as an ingredient in sheep dip. The percentage of cresol 

 used with water depends on the government rating of the cresol. 



Examine a sample of cresol, and of liquor cresolis compositus. 



d. Crude Carbolic Acid is a, coal tar product with a low phenol 

 and cresylic acid content. It is poisonous. (Pure carbolic acid 

 phenol must not be confused herewith.) In using carbolic acid 

 as an ingredient for dips and disinfectants, the phenol content 

 should be known, since there is considerable fluctuation in the 

 amount of this ingredient. Dilution with water to 2 to 4% of 

 its phenol content is sufficient for disinfection. For dipping the 

 same may be said as for cresol. 



Examine a sample of crude carbolic acid, and samples of 

 carbolic acid crystals, which are pure phenol. 



e. Creoline is a coal tar product of a low phenol content. It 

 is poisonous. Creoline is much used for dipping and disinfection. 

 Drop a little in water and notice the result. For dipping "pur- 

 poses dilute with water to from 2 to 4%. It is useful in destroy- 

 ing lice, and less so for scab mites, on domesticated animals. 



