4 Farmers’ Bulletin 1104. 
them, and they were on every object and in everything. The mattress was 
found to contain millions of them, and seemed to be the source of the supply. 
In a second case, newly purchased upholstered furniture became a 
distributing point. When such excessive outbreaks of the pests 
occur in newly purchased mattresses and furniture, the cause beyond 
doubt is the use at the factory of unsterilized stuffings. 
HOW TO CONTROL BOOK-LICE IN HOUSES. 
Where only a few book-lice are present, a thorough cleaning, air- 
ing, and drying of the room is all that is needed, provided the source 
of infestation is within the room itself. As many as possible of the 
objects in the room should be removed and thoroughly sunned on a 
bright day. The room should be heated to a temperature of 120° 
to 140° F. for several hours. Psocids are soft-bodied insects, and 
succumb to a prolonged drying due to heat. Where rooms are 
located on the ground floor in loosely constructed buildings in shaded 
and damp situations, as are many summer cottages, so many psocids 
come in from the outside that almost no treatment will entirely rid 
a room of them. 
When book-lice swarm in alarming numbers over and throughout 
a room the breeding places should be located at once. If the source 
is old straw or husk fillings of mattresses, these should be removed 
and burned wherever possible. Thorough fumigation with the fumes 
of sulphur,’ 1 pound of sulphur being burned for each 1,000 cubic 
feet of space, is effective. Where other pests are present, such as 
bedbugs, and where the bleaching effects of the fumes can be disre- 
garded, as in barracks, 5 pounds of sulphur will prove effective. 
During fumigation the rooms should be kept closed as tightly as 
possible, and after five or six hours opened from without and thor- 
oughly aired. Fumigation with hydrocyanic-acid gas is very ef- 
fective, but dangerous in the hands of inexperienced persons. (See 
Farmers’ Bulletin 699.) 
Closets, boxes, trunks, and sometimes even entire rooms, where in- 
fested objects are kept near the floor, can be fumigated satisfactorily 
with carbon disulphid. (See Farmers’ Bulletin 799.) In addition 
to cleanliness and plenty of sunlight, heat or fumigation, wherever 
it can be applied, will yield the best results, if the source of infesta- 
tion has been removed. 
1 Before resorting to sulphur fumigation the householder should be warned that sulphur 
fumes can unite with moisture in the air to form sulphurie acid, thus having a bleach- 
ing effect upon wall paper and other articles, as well as tarnishing metals of all sorts. 
The damper the house, the greater the bleaching. In houses thoroughly dried by heat 
very little bleaching occurs. Householders possessing homes furnished with rare or 
valuable articles should never use sulphur. 
O 
