74 



PRINCIPAL HOUSEHOLD INSECTS. 



to save tlie building it was necessarj^ ultimately to tear it down and 

 replace it with au iron structure. In this country instances are on 

 record of very serious damage to books and papers. An accumulation 

 of books and papers belonging to the State of Illinois was thoroughly 

 ruined by their attacks. A school library in South Carolina, which 

 had been left closed for the summer, was found on being opened in the 

 autumn to be completely eaten out and rendered valueless. In the 

 Department of Agriculture an accumulation of records and documents 

 stored in a vault which was not thoroughly dry, and allowed to remain 

 undisturbed for several years, on examination proved to be thoroughly 



Fk;. ;>1. — Tmni's jJaviprs: a. qnoen : h. nymph of winged female; r, worker: d. soldier — all enlarged 



(original). 



mined and ruined by white ants. Humboldt, on the authority of 

 Hagen, accounts for the rarity of old books in Xew Spain by the fre- 

 quency of the destructive work of these insects. 



Numerous instances of damage to underpinning of buildings and to 

 timbers are also on record. The flooring of one of the largest sections 

 of the United States jS'ational Museum has, for some years back, been 

 annually undermined and weakened by a very large colony of these 

 pests which could not be located, and finally the present season the 

 authorities solved the problem by replacing the wood floor with one of 

 cement. A few years ago it was found necessary to tear down and 



