1847.] J\'oxious Insects. 149 



pearance, but much more active in all its motions; yet so fragile 

 in its structure, that a slight brush with the finger annihilates 

 it, and " leaves not a wreck behind." It not only infests old 

 books, but abounds also in great numbers in neglected collections 

 of dried plants and of insects. Indeed the utmost care can scarce- 

 ly keep it from cabinets of these departments of natural history, 

 to which it is very injurious, devouring the more delicate and 

 minute parts of the specimens. It also congregates among old 

 and little-used furniture, old wood, &c. ; and in brushing off the 

 articles and sweeping up the dust of an unfiequented apartment, 

 the contents of the dust-pan are sometimes all alive with these 

 mites, and hence many of our housewives familiarly designate 

 them l)y the name o( dust lice. 



If one of these lice be dropped into a phial or box impregnated 

 with the vapor of camphor, it is in most cases paialysed instantly, 

 so that it seldom moves from the spot on which it falls. An at- 

 mosphere of choke-damp scarcely produces a more sudden as- 

 phyxia in man, than does a camphorated atmosphere in this in- 

 sect. Its limbs are rapidly convulsed with violent spasms, which 

 subside only in death, even though it be removed from the noxious 

 vapor. Camphor operates in the same way, though less suddenly, 

 upon many other insects. The symptoms which it produces seem 

 to be identical with those caused in the higher orders of animals 

 by an excessive dose of the same substance. This is therefore a 

 most efficient remedy against the depredations of this insect. Its 

 powder should occasionally be sprinkled between the leaves of 

 herbariums, and eveiy collector of insects is aware that the 

 drawers of his cabinet must never be without it. The vapor of 

 oil of pine, the common spirits of turpentine, is perhaps equally 

 as efficient as camphor for destroying this insect. Phials con- 

 taining this oil, and loosely stopped, to allow it'to slowly evapo- 

 rate, may also be placed in situations where injury from this 

 depredator is feared. 



This species derives its technical name from the habit which it 

 was deemed to possess, of occasionally making a slight tapping 

 noise, analogous to the ticking of a watch; on which account it 

 has sometimes been called the death-watch, a name which is more 

 frequently bestowed upon some coleopterous insects of the genus 

 Anobium, which are well known to possess this faculty. Writers 

 of the present day are not agreed whether the habit alluded to 

 does belong to the present species, or not. It is difficult to con- 

 ceive it possible for so minute, so soft, and weak an insect, to 

 produce any audible sound. A box, purposely allowed to be 

 much infested w^ith these lice, has stood upon the table beside me, 

 and often less than two feet from my ear, during the past season; 



