Mites and Lice on Poultry, 25 



number of domestic fowls used in experimental work, when either 

 the dusting or the dipping method was used. In fowls that are being 

 dusted there is occasionally some temporary irritation of the air 

 passages, as evidenced by labored breathing and sneezing. This effect 

 is not noticeable a few minutes after treatment. 



Caution is necessary to prevent the sodium fluorid when used in 

 dust form from gaining access to the food and water of the fowls, and 

 to empty out sodium fluorid solution where the chickens can not 

 drink it before it soaks into the ground. It should be remembered 

 that the material is rather poisonous if taken internally. 



Wliere some of the sodium fluorid in the dust form reaches the 

 body of the operator and is allowed to remain for a number of hours, 

 as may be the case when several hundred fowls are dusted, local irrita- 

 tion and burning may occur on tender portions of the skin. In dusting 

 large flocks it is therefore advisable to do the work on a table rather 

 than to hold the fowls between the knees as is sometimes done. 

 The solution does not injure the hands, even when dipping is con- 

 tinued for a number of hours, except in cases where sores are present 

 which may become slightly irritated. 



Precaution should be taken not to allow sodium fluorid solution 

 to remain in galvanized vessels any great length of time. In fact, 

 it is best not to keep it over night in tubs or galvanized containers, 

 as it will injure them. 



COST OF APPLICATION. 



One jjound of commercial sodium fluorid, when applied by the 

 "pinch method," will treat approximately 100 hens; thus at a cost 

 of 40 cents per pound the expense for material will average less than 

 one-half cent per fowl. It has been found by actual practice in 

 treating several hundred fowls that an average of from two to three 

 minutes is required for treating each fowl, one man doing the work. 

 This includes the time necessary for catching the birds as well as 

 dusting them. The dusting itself occupies about one to two min- 

 utes. Of course, the time involved in catching them would vary in 

 every individual instance according to conditions. Using the above 

 figures as a basis, and figuring a man's time at 30 cents per hour, it 

 would cost approximately, $1.05 to treat 100 fowls by the pinch 

 method. 



When the dust can is used the amount of material is usually 

 double and the average time per bird is somewhat increased. 



By the dipping method the amount of the material is considerably 

 reduced, especially if large flocks are to be treated at one time. 

 Over 800 fowls have been dipped at one time, an average of 5.2 ounces 

 of sodium fluorid to 100 fowls being used, which at the same figure 

 would cost 13 cents. The labor involved is also thus reduced. The 

 average time for catching and dipping the birds was about one 

 and three-fourths minutes per fowl, one man working. This makes 



