INSECTS AFFECTING MAN AND ANIMALS 207 



ten pounds of sulphur to a half bushel of air slaked lime, 

 mixed together, should be used for dusting the hens and 

 nests and be mixed with the dust bath. A thorough spray- 

 ing of the house with kerosene emulsion as advised for mites 

 will also be valuable. In a recent circular Dr. C. A. Lueder 

 (50) states that the lice may be killed by treatment with 

 blue ointment according to the following directions: "Re- 

 move some feathers from the back part of the body near the 

 vent. Take a pinch of ointment a little larger than a pea 

 and thoroughly rub a portion of it where the feathers were 

 removed. Distribute the balance evenly on the shanks 

 of the legs and the lice will disappear. Blue ointment should 

 be applied during the month of December and again about 

 one month before brooding . season. Blue ointment is a 

 medical preparation containing mercury, which is poisonous 

 when taken into the system by the mouth or absorbed through 

 the skin in large quantities. Young animals are very suscept- 

 ible to mercury, therefore none should be used on young 

 chickens. Healthy fowls six months old may be treated." 

 126. Poultry Mites. The Chicken Mite* (25) is the most 

 common mite affecting poultry and belongs to the same order 

 of mites as that causing the sheep scab (p. 203). It is an 

 oval, flattened mite about one-twentieth of an inch long, of 

 a pale gray color with darker spots, unless it has been feed- 

 ing, when it is more or less reddish with blood. The eggs are 

 laid in cracks and crevices where there is some manure or 

 filth and the young mites feed largely, if not entirely, on 

 filth. They become grown in about ten days and, therefore, 

 increase rapidly. The mites remain on the poultry only 

 while feeding and then retire into crevices, being most active 

 at night. Dark, damp houses are much worse infested than 

 those with good ventilation and plenty of sunlight. 



* Dermanyssus gallincc Redi. Class Arachnida, see page 21. 



