522 DISEASES OF CATTLE. 



preparation the strength of which is not given on the outside of the 

 package. 



In preparing these dips the nicotin solution and sulphur should 

 be mixed together with water before adding them to the water in the 

 dipping vat. On no account should the dip be heated above 110^ F. 

 after the nicotin solution is added, as heat is liable to evaporate the 

 nicotin and weaken the dip. 



For ojSicial dippings the dipping bath should be used at a tem- 

 perature of 100° to 105° F. and at all times must be maintained at 

 a strength of not less than five one-hundredths of 1 per cent nicotin 

 as indicated by a field test approved by the Bureau of Animal In- 

 dustry. 



A homemade nicotin dip may be prepared as follows : 



For each 100 gallons of dip desired, take 21 pounds of good, pre- 

 pared tobacco leaves; soak the leaves in cold or lukewarm water 

 for 24 hours in a covered pot or kettle; then bring the water to near 

 the boiling point for a moment, and, if in the morning, allow the 

 infusion to draw^ for an hour; if in the evening, allow it to draw 

 overnight; the liquid is next strained (pressure being used to extract 

 as much nicotin as possible from the wet leaves) and diluted to 100 

 gallons per 21 pounds of tobacco. This dip should be used as fresh 

 as possible, as it contains a large amount of organic material which 

 will soon decompose. 



BEAUMONT OIL EMULSION. 



Directions for Tnaking 100 gallons. — ^Dissolve with the aid of heat 

 5 pounds of hard soap (ordinary laundry soaps are satisfactory) in 

 5 gallons of soft water ; to this solution add 20 gallons of Beaumont 

 crude petroleum or a similar oil, mixing with a spray pump, or 

 otherwise, in a thorough manner. TVlien properly prepared the con- 

 centrated emulsion will stand indefinitely without any tendency 

 toward a separation of the oil and water, and can be diluted in any 

 proportion with cold soft water. To make a 20 per cent emulsion 

 add to the concentrated emulsion sufficient soft water to bring the 

 total up to 100 gallons, keeping the whole mass thoroughly agitated. 



Oil emulsions are no longer permitted for official dippings of 

 cattle. In view of the difficulty in obtaining suitable oils, and the 

 occasionally severe effects upon cattle, particularly in very cold or 

 very warm weather, their use is not advisable except under excep- 

 tional circumstances. 



CHORIOPTIC MANGE. 



Chorioptic mange, due to a species of mite different from that caus- 

 ing common cattle mange, is confined almost entirely to the region at 



