4 BULLETIN 888, U. S. DEPARTMENT OF AGRICULTURE. 



breathing and general weakness when released from the box. These 

 effects passed away in 5 or 10 minutes, and in no case was any per- 

 manent injury noted. This treatment also left the feathers some- 

 what soiled, as the fowls in their struggles came in contact with the 

 freshly treated surfaces of the box. 



In two tests where the bottom of the nest box used by a sitting 

 hen was painted with this type of preparation it was noted that from 

 95 to 100 per cent of the lice on the hen were killed or repelled and 

 the eggs apparently were not injured. While sufficient tests were 

 not made to determine the practicability of this treatment for the 

 control of lice on sitting hens, it appears to be worthy of further 

 investigation. 



OIL PREPARATIONS APPLIED TO ROOSTS, DROPPING BOARDS, AND INTERIOR OF 



CHICKEN HOUSES. 



There have been many advocates of the theory that chicken lice 

 can be killed by painting the roosts and dropping boards or the 

 whole interior of the poultry house with various oil mixtures, the idea 

 being that the vapors or gases arising from these paints would pene- 

 trate the feathers of the roosting fowls and kill the lice. This 

 method was given a very extensive trial and not one of the 42 differ- 

 ent preparations tested was found to be of any value. These prepa- 

 rations contained one or more of the following ingredients: Phenols, 

 tar oils, hydrocarbon oils, creosote oil, carbon disulphid, wood-tar 

 distillate, benzol, nitrobenzene, naphthalene, anthracene oil, and 

 pyridine and were of the same general character as those discussed 

 in Table I (p. 3). 



In these experiments the roosts and dropping boards or the whole 

 interior of the house were thoroughly painted or sprayed just before 

 the fowls went to roost and all doors, windows, and ventilators were 

 closed during the first night. . Five badly infested fowls were used in 

 each test and at the end of one week examination was made for 

 living lice. Although an occasional dead louse was found on the 

 dropping boards, in no case was the treatment of any practical 

 value. Since many of these same preparations were found to be 

 effective when used as fumigants in small boxes, it is apparent that 

 the ineffectiveness of this house treatment is due to the fact that the 

 fumes do not become concentrated enough to kill the lice. Tests 

 were also made with lime-sulphur applied in the same way and this 

 also was found to be of no value. 



MERCURIAL OINTMENT. 



Five proprietary and two homemade mercurial ointments were 

 tested and found to kill from 95 to 100 per cent of the body lice 

 present. These ointments contained from 3 to 26 per cent of mercury 

 mixed with lard, vaseline, paraffin, or some semisolid of this type 



