PSOROPTIC MANGE — SHEEP SCAB. 633 



Formula' for arsenical dips. — Finlay Dun recommends the follow- 

 ing : — Take 3 lbs. each of arsenic, soda ash (impure sodium carbonate) 

 or pearl ash (impure potassium carbonate), soft soap, and sulphur. A 

 pint or two of naphtha may be added if desired. The ingredients are 

 best dissolved in 10 to 20 gallons of boiling water, and cold water is 

 added to make up 100 gallons. The head of the sheep must, -of course, 

 be kept out of the bath. 



A mixture highly endorsed by certain parties consists of the following 

 ingredients : 



Commercially pure arsenite of soda . . . . . . 14 lbs. 



Ground roll sulphur .. •.. .. .. .. 34| ,, 



Water 432 gallons (U.S.) 



The arsenite of soda is thoroughly mixed with the sulphur before 

 being added to the water. 



Precautions in use of arsenical mixtures. — Any person using an 

 arsenical dip should bear in mind that he is dealing with a deadly 

 poison. The following precautions should be observed : 



(1) Yards into which newly-dipped sheep are to be turned should 

 first be cleared of all green food, hay, and even fresh litter ; if perfectly 

 empty the}^ are still safer. (2) When the dipping is finished, the yard 

 should be cleaned, washed, and swept, and any unused ooze should at 

 once be poured down a drain which will not contaminate food or premises 

 used by any animals. (3) Dipped sheep should remain in an open, 

 exposed place, as on dry ground. (4) Overcrowding should be avoided, 

 and every facility given for rapid drying, w^hich is greatly facilitated by 

 selecting fine, clear, dry weather for dipping. (5) On no account should 

 sheep be returned to their grazings until they are dry and all risk of 

 dripping is passed. 



The feeling of the United States Bureau of Agriculture towards ar- 

 senical dips is shown by the following : 



Suggestion as to danger. — The formulae given above are copied from 

 the writings of men who have had wide experience in dipping, but this 

 Bureau assumes no responsibility for the efficacy of the dips given, or 

 for their correct proportions. Furthermore, as long as efficacious non- 

 poisonous dips are to be had, w^e see no necessity for running the risks 

 attendant upon the use of poisonous dips. 



Carbolic Dips. 



This class of dips kills the scab mites very quickly, but unfortunately 

 the wash soon leaves the sheep, which is consequently not protected from 

 reinfection in the pastures. If, therefore, a carbolic dip is selected, it is 



