542 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



specters accord this homemade tobacco dip third place among the 

 dips officially recognized. 



By all means the use of a tobacco dip, or of the tobacco-and- 

 sulphur dip, in preference to the lime-and-sulphur dips is advised in 

 case the sheep to be dipped show no unmistakable signs of scab. 



At present most tobacco dips are made either with the extract 

 of tobacco or with nicotine solution, on account of the convenience 

 of mixing these preparations with water. The regulations of the 

 Bureau of Animal Industry call for 0.07 of 1 per cent of nicotine in 

 a tobacco dip.* Sufficient nicotine would therefore be furnished for 

 100 gallons (about 800 pounds) of dip by 1 pound of a 40 per cent 

 solution of nicotine. The formula for this dip would be : 



Nicotine pound . . 0.56 



Water gallons . . 100 



The nicotine solution or tobacco extract should not be added to 

 the dip until just before it is ready for use, and then the dip should 

 be thoroughly stirred, so as to secure a uniform mixture. The dip 

 should on no account be heated above 110 F. after the nicotine so- 

 lution is added, as heat is liable to evaporate the nicotine and weaken 

 the dip. It will be an easy matter to calculate how much nicotine 

 solution or extract of tobacco should be used for 100 gallons of water 

 by dividing the quantity of nicotine required in the dip by the pro- 

 portion of nicotine in the extract. For example, suppose the nicotine 

 solution contains 25 per cent of nicotine, we have 0.56-^0.25=2.24. 

 Therefore in this case it would require 2.24 pounds of nicotine solu- 

 tion for the 100 gallons of dip. Or, if a tobacco extract is used, hav- 

 ing, for example, 2.40 per cent of nicotine, the formula would be as 

 follows: 0.56-^0.024=23.33, and therefore 23.33 pounds would be 

 required for 100 gallons of dip. 



The advantages of the tobacco dip are that it is comparatively 

 cheap, since the farmer can grow his own tobacco ; that it is effectual 

 and at the same time not injurious to the wool. The disadvantages 

 of the dip are that it sometimes sickens the sheep ; that it also occa- 

 sionally sickens the persons who use it, especially if they are not 

 smokers ; it spoils very rapidly ; it causes a greater setback, or shrink- 

 age, than lime and sulphur, but less of a setback than carbolic dips. 



Arsenical Dips. There are both homemade arsenical dips and 

 secret proprietary arsenical dips. It is well to use special precautions 

 with both because of the danger connected with them. 



The drawbacks to the use of arsenic may be summed up some- 

 what as follows: (a) Its danger as a deadly poison, (b) Its drying 

 effect on the wool, (c) Its weakening of the fiber of the wool in one 

 particular part near the skin, where it comes in contact with the 

 tender wool roots at the time of dipping, (d) Its not feeding the 

 wool or stimulating the growth, or increasing the weight of the 

 fleece, as good oleaginous dips do. (e) The danger arising from the 

 sheep pasturing, after coming out of the bath, where the wash may 

 possibly have dripped from the fleece, or where showers of rain, 



*See regulation 33, page 551. This order also dispenses with flowers of sut 

 phur in the official tobacco dips . 



