482 



SCIENCE. 



[Vol. VII., No. 173 



overcautious to say that some means should be taken 

 to prevent their being destroyed by insect foes. 



If labels should be dipped in an alcoholic solution 

 of corrosive sublimate, it would doubtless render 

 them perfectly safe from the attacks of Lepisma, 

 and other insects as well. In poisoning dried plants 

 to prevent the attack of insects, botanists use a solu- 

 tion of the strength of one ounce of corrosive sub- 

 limate to a quart of alcohol. The same, or a solution 

 of double strength, would seem advisable for labels. 

 If, after dipping, they are dried between sheets of 

 blotting-paper under a weight, or in a letter-press, 

 the labels will not curl, or be injured in any way. 

 Corrosive sublimate, under the conditions of a cab- 

 inet, is a perfectly stable compound, and would re- 

 tain its protecting-qualities for all time ; whereas 

 most insecticides have to be renewed occasionally, 

 and w 7 ould render themselves objectionable in one 

 way or another by their presence. Labels may be 

 treated with great rapidity if a large number are 

 done at one time. Those already written on may be 

 poisoned without affecting the ink ; at least, such has 

 been my experience. 



Paper sized with lead might be proof against in- 

 sects ; and I have not seen any injuries done to labels 

 sized with rosin, though a large number were in the 

 cases where Lepisma committed its ravages. 



Labels, after being: written, could be coated over 

 with water-glass (silicate of soda), which forms a 

 hard, transparent glaze, and would surely be proof 

 against insects ; but it is objectionable, in that it 

 takes a good deal of time to brush over each label 

 after writing it, and, besides, the label curls some- 

 what in drying. 



Professor Hagen has been told by ladies that their 

 silk dresses, always black ones, had been destroyed 

 by carpet-bugs, and has answered that they only 

 attack wool, and has only lately learned that Lepisma 

 did the damage. He also says that gold lettering on 

 the backs of books, which is commonly done by 

 putting gold on paste and burning it in, has been un- 

 dermined by Lepisma. 



When I first showed the labels to Prof. H. A. 

 Hagen, seeking his advice, he was much puzzled, as 

 he thought Lepisma could not have eaten them, and 

 Anobium, the great library pest, does not like starch ; 

 in fact, he says it has been recommended to use 

 such paste as is made of pure starch, in binding 

 books, to avoid the latter. 



Professor Hagen was much inte rested in this pest, 

 new as such to him, and, looking up the literature 

 of the subject, read a paper on it before the ' Thurs- 

 day club.' Part of his delightful paper was pub- 

 lished in the Boston evening transcript of March 13. 



He very kindly wished me to write an account of 

 what I had observed in regard to Lepisma, and to 

 add from his manuscript the facts which he has 

 gathered : they are contained in abstract in the fol- 

 lowing : — 



Lepisma destructive to the labels is a true Ameri- 

 can insect, described by Professor Packard as L. 

 domestica. There are half a dozen species in the 

 United States. The principal one in Europe is L. 

 sacebarina, the small blue silver-fish. This insect is 

 found in dark corners, and near provisions. In 

 Europe it has always, but without proof, been con- 

 ridered as imported from America It has been 

 known there for over two hundred years ; but its 

 existence cannot be traced before the discovery of 

 America. The whole of its flexible body is covered 



with fine irridescent scales which have been used as 

 delicate microscopical tests ; and to these hairs it 

 owes its common name of silver-fish. 



Nearly six years ago, at a meeting of librarians in 

 Boston, Professor Hagen read a paper on library 

 pests. After a review of the literature then at com- 

 mand, he concluded that only two North American 

 insects were to be considered very dangerous to books, 

 — the white ant ; and Anobium, a small beetle which 

 is also injurious to old furniture. These additions to 

 his communication have been published ; but they 

 contain only isolated cases, certainly nothing of gen- 

 eral importance. 



The earliest notice of the small European species 

 is in R. Hooker's ' Micrographia,' a folio published in 

 London in 1665, and containing an account of in- 

 numerable things examined under the microscope. 

 It is still respected for the accuracy of the author's 

 statements. He figures Lepisma, and calls it book- 

 worm, and says it corrodes and eats holes in the 

 leaves and covers of books. On Mr. Hooker's 

 authority, Lepisma was reported as injuring books ; 

 but as Mr. Hooker apparently confounded destruc- 

 tion done by Anobium with that of Lepisma, and 

 since during the next hundred years no damages due 

 to the latter were observed, the observation was 

 doubted ; and Professor Herman of Strasburg, in 

 his prize essay on library pests, declared, in 1774, 

 that Lepisma was erroneously recorded as injurious 

 to books. For this reason, Professor Hagen did not 

 mention Lepisma in his communication on library 

 pests ; the more so, as again in the next hundred 

 years no new observations had been recorded. 



Soon after his communication, new proofs of the 

 depredations of Lepisma were observed. Professor 

 Westwood of Oxford showed at the Naturalists' as- 

 sociation in 1879 a framed and glazed print, in which 

 the plain paper was eaten, while the parts covered 

 with printing-ink were untouched. He mentioned 

 that the same fact had been observed in India, where 

 government records had been injured in a similar 

 way. Patrick Brown says, in his ' Natural history 

 of Jamaica,' that L. saccharina is very common 

 there, and extremely destructive to books and wool- 

 len clothing. This statement was reproduced by 

 Linnaeus, but was later considered as unreliable. 

 M. de Rossi writes, in 1884, that L. saccharina likes 

 damp places. It destroyed paper-hangings in his 

 house, muslin curtains were perforated, and living 

 animals found near the holes ; also insect-boxes, 

 and wings of butterflies, have been damaged. 

 Professor Liversidge, in Sydney, reports the same 

 year that L. saccharina is very common in New- 

 South Wales. He says it does not do much harm to 

 books, as it cannot get in between the leaves, but 

 injured loose papers, maps, and labels. The loose- 

 edges of piles or bundles of letters suffered more 

 than the interior. The same calamity is reported by 

 Mr. H. Lucas, assistant in the museum of the Jardin 

 des Plantes in Paris. He says L. saccharina destroys 

 labels of white paper, but parts printed on with 

 minium and oil remained untouched. Labels of 

 starched paper were much injured, but only the 

 white parts. When leaving the country in 1802, he 

 put in a drawer various articles of starched clothing, 

 and, returning after six weeks, found numerous holes 

 in it, and Lepisma near by. Dr. Aube, in Paris, 

 says that the black part of the backs of books has 

 been nearly destroyed, probably by Lepisma. The 

 well-known antiquary, Mr. Quaritch of London, 



