DIP MATERIAL 653 



purposes under any circumstances. Even the purest 

 samples which come clear from the still, worth at present 

 about 43. per gallon wholesale, darken on being kept 

 a couple of months, although no sediment settles. The 

 naphthalene which it contains is largely accountable for 

 the discoloration, and it is believed to exercise an injurious 

 influence upon the wool when the oil is not thoroughly 

 saponified by mixing with from 3 to 6 Ibs. of black 

 soap per gallon. This risk is minimised, if not wholly 

 removed, when the oil and soap are mixed a few months before 

 use, so that no crystallisation can take place, and the bath 

 kept at a temperature of not less than 60, but still better, 70 

 or 80 R, and, if the deposit from oil that has been exposed to 

 frosty weather be removed before use, the dip ingredients 

 carefully mixed, and the contents of the bath repeatedly and 

 thoroughly stirred. Pitch-oil is of no value as a preventive 

 of fly-blowing. The increase of the prices of burning oils and 

 of carbolic acid which are made from coal-tar may check the 

 use of pitch-oil as a dipping material. 



Carbolic acid and other crude coal-tar products used by 

 unskilled people as sheep-dips, are very liable to poison 

 sheep by absorption. Though a light scum floats on the top, 

 the danger is in the heavy products that sink to the bottom 

 and remain in an undiluted condition. " The symptoms are 

 rapid breathing followed by paralysis, convulsions, and death. 

 Treatment. Wash off the acid as quickly as possible, and 

 give a dose of Glauber's salts." 



A stronger solution of any one of the above-named 

 poisonous substances would destroy the living external para- 

 sites which infest sheep, but at the risk of injury to the sheep. 

 The desired result can be effectually secured without danger 

 to the animals by the use of dips made up of combinations of 

 two or more of these substances in the safe proportions which 

 we have stated. The immediate action of arsenic and of 

 carbolic dips can be fortified by the addition of sulphur or 

 tobacco. Either addition also prolongs the action of a dip, 

 and thereby materially adds to its ultimate efficiency. Con- 

 siderable variety can thus be imparted to the means at the 

 disposal of those to be intrusted with the eradication of scab, 

 so as to enable them to select the combinations necessary to 

 combat the special difficulties which present themselves in 



