SHEEP SCAB. 



19 



1)6 taken into consideration. After computing the amount of dip 



required to charge the vat, the average amount of dip which each 



sheep Avill carry out should be estimated; this should be multiplied 



b}^ the number of sheep to be dipped and the product 



so obtained added to the amount required to fill the ^) 



Yiit. If the vat and draining pens are Avatertight, 



so that no dip is lost through these sources, the total 



as given above should show the approximate number 



of gallons of dip required to complete the Avork. 



The temperature of the dip should not be a matter 

 of guessAvork, but should be ascertained accurately 

 by using a thermometer. If it is too high the sheep 

 may be injured, and if too low failure to cure Avill 

 probably result. In field operations, Avhen the dip- 

 ping is supervised by inspectors, the temperature of 

 the dip is maintained at 100° to 105° F. Practice has 

 demonstrated that the lime-and-sulphur and nicotin 

 dips should be used at these tempera- 

 tures. The coal-tar-creosote and cre- 

 sylic-acicl dips should be used at 

 slightly loAver temperatures, the maxi- 

 mum for these being 95° F. For use 

 in dipping small lots of farm sheep 

 an ordinar}^ dairy thermometer Avill 

 answer the purpose. At the large 

 vats where a great many sheep are to be dipped at 

 least tAvo thermometers should be provided as a pre- 

 caution against breakage and delay. The thermom- 

 eters used at dipping A^ats should be tested occa- 

 sionally by comparison Avith another thermometer, so 

 as to be sure that they are registering properly. (See 

 figs. 13 and 14.) 



After the vat is filled to the required capacity the 

 contents should be Avell mixed by stirring, in order 

 that the temperature may be uniform throughout. 

 A good method of stirring the dip in large vats is 

 to take a 5-gallon pail or dip container, punch holes 

 near the top, insert a Avire for a bail, alloAv the can to 

 fill and partially sink, then drag it rapidly from one 

 end of the vat to the other, and repeat the process until 

 the temperature is uniform as shoAvn by temperatures 

 taken at several points in the vat. Stirring plungers are useful 

 implements, and, as they are easily made, one or more should be 

 provided at every Aat. They are used in a manner similar to the 



Fig. 13. — Floating 

 dairy thermom- 

 eter. 



Fig. 14. — T h e r- 

 mometer used 

 by Bureau of 

 Animal Indus- 

 try inspectors, 

 in holder whit- 

 tled from a 

 block of wood. 



