ENTOMOLOGY

342 SANITARY ENTOMOLOGYWhen comparatively few fowls are to be treated or if chicks or unhealthyindividuals are concerned, it is advisable to follow what we tennthe pinch method of application. For grown fowls about twelve pinchesof the powder are placed on different regions of the bird at the base ofthe feathers and distributed as follows: One pinch on the head, one onthe neck, one on the throat, two on the back, one on the breast, onebelow the vent, one on the tail, one on either thigh, and one scattered allthe under side of each wing when spread. With young chickens usuallyone pinch is sufficient, this being distributed on the head, neck, alongthe throat and on the back. A few people have reported loss of youngchicks through the application of the powder to them at night. We aretherefore recommending that the treatment be done during the early partof the day while the chicks are active. This gives opportunity for excessdust to be shaken oW before roosting time. Another precaution is toapply the treatment where the dust will not have opportunity to get intothe food or water. As the dust is very irritating to the nose and throat,At is advisable to wear a dust guard or a moistened cloth tied over the nose,and mouth when applying it.By the dry method one pound is sufficient to treat 100 grown fowlsand they can be gone over at the rate of about one to every two or threeminutes, with one man working.In following the dipping method, the sodium fluoride is dissolvedin water at the rate of one ounce or three level tablespoons to each gallon.A tub is well filled with this solution which should be tepid (70 0 to 80 0 F.)but not warm, and the fowl, held by grasping the base of the wingsover the back, is lowered quickly into the water. With the other handthe feathers are ruffled so as to allow the liquid to penetrate to the skin.The head is then ducked, lightly rubbed to induce penetration and thefowl released. By this method the danger of not· treating all portionsof a fowl is practically eliminated, the time of treatment is reduced toabout three-fourths minute per fowl and the amount of material alsomarkedly reduced. The irritating eWect of the dust on the operator isalso avoided.It is of course necessary to cnose a warm day so that the featherswill ciry quickly. It should be stated, however, that the plumage is notthoroughly wet as would be the case with most dips. The featheI'6 becomecompletely dry in a couple of hours. There is absolutely no stainingor injury to the feathers, no tainting of flesh and no skin irritationproduced either by the dipping or dusting methods. As the material iscorrosive it is inadvisable fo)' one doing the dipping to subject lesions onthe hands to the liquid and the utensils used should be emptied immediatelyafter completing the work.Since one application will completely destroy all forms of lice on II.