■250 PARASITIC DISEASES OF THE SKIN. 



The extracts from the Biireau of Animal Industry concern- 

 ing the use of arsenic are fully endorsed by the majority of flock 

 owners. 



Among the most jDopular agents used for dipping purposes 

 we find tobacco and carbolic acid; these two enter largely into 

 the composition of the most extensively used prepared dips. 



Cobacco. 



Is a very efficient agent for the destruction of the acari. 

 Its effects appear to last longer than those of the cafbolic acid or 

 coal tar preparations. "We find it as the base of some of the 

 most popular sheep dips. Home-made tobacco infusions, pre- 

 pared by boiling a certain quantity of the natural leaf in a given 

 amount of water, were formerly very popular with sheep owners, 

 but since manufactured extracts have been placed on the market 

 their extended use has largely been- superceded by the prepared 

 article, which possesses the advantage of always being imiform 

 in strength and requiring only the admixture of warm water to 

 be ready for use. 



Carbolic Hcid. 



Carbolic acid is also a reliable parasiticide. Many of the 

 cold water preparations are largely composed of this article mixed 

 with other ingredients, and presented to the public in such a 

 form as to make a perfect emulsion when mixed with water. 

 Cbe Dipping plant. 



This consists of a trough or vat and catching and draining 

 pens. The vat is made either circular or straight. It should 

 be at least five and one-half feet deep, and not to exceed six 

 inches in width inside measure at the bottom, and twenty inches 

 in the clear at the top. Its length will depend on the number 

 of sheep intended to be dipped in it at any one time. For a dip- 

 ping plant with a capacity for 5,000 sheep per day the following 

 dimensions will be found satisfactory: 



