4 BULLETIN 1228, U. S. DEPARTMENT OF AGRICULTURE. 
An egg containing 5 per cent of naphthalene and a small quantity 
of formaldehyde was used for 19 days without any effect. 
A plaster egg containing a tin receptacle holding a mixture of 
naphthalene and sawdust was charged weekly with a mixture com- 
posed of turpentine 54 per cent, formaldehyde 18 per cent, and 
water 28 per cent. This egg was used for 4 weeks without any effect. 
Two kinds of prepared nesting hair (fats 9.4 and 3.8 per cent, 
respectively) were placed in infested jars for 8 days. These proved 
valueless. 
Two tests were made with nesting materials of shredded bark and 
crumbled leaves of cedar. This material was placed in clean nest 
boxes in mite-infested premises, and sitting hens were employed. 
In both cases mite infestation developed. 
TREATMENT OF THE HEN. 
Six hens were treated by rubbing into the skin 1 inch below the 
vent a preparation containing 5.6 per cent of mercury. The fowls 
were kept for 16 days in an infested chicken house. At the end of 
that time the house was still infested. 
CONCLUSIONS REGARDING MISCELLANEOUS TREATMENTS. 
Of the miscellaneous methods listed above only two indicated any 
efficiency — naphthalene fumigation and the medicated roosts. 
The tests with the former were made in a fumigatorium under 
optimum fumigating conditions. This method would be of value 
where nest boxes, coops, or roosts were to be treated, but an infested 
house could not be treated unless very nearly air-tight. The fact 
that sulphur burnt at the rate of over 6 pounds to 1,000 cubic feet 
was quite inefficient in a chicken house at least as nearly air-tight 
as the average house precludes satisfactory fumigation under usual 
conditions. 
The medicated roost was of some value, since it afforded protection 
to roosting fowls for a long time, but unless the rest of the premises 
are treated no protection is afforded fowls on the nest. 
DUSTS. 
In the dusting tests various makes of hand dusters were used. 
The following dusts were without value under natural conditions: 
Air-slaked lime, Paris green, hellebore, calcium fluorid, sodium 
fluorid, sodium silico fluorid, barium fluorid, barium tetrasulphid, 
mercuric chlorid, and sulphur (refined and commercial). Witn the 
exception of calcium fluorid and mercuric chlorid none of these sub- 
stances was efficient even in jar tests. 
TOBACCO. 
Tobacco dusts containing nicotine up to 5.26 per cent (the strongest 
percentage tested) were inefficient. 
PHENOLS. 
Dusts containing phenols up to 2 per cent were inefficient. 
