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When the excavation had proceeded so far that the insect could descend into it, the music was suspended, but renewed from time to time, as the little creature came to the orifice to throw out the chips, to rest, or to enjoy the fresh air. By degrees a mound of sawdust was formed at the base of the pillar, consisting of particles abraded by the mandibles of the bee; and these, when the hollow was completed to the depth of several inches, were partially replaced in the excavation, after being agglutinated to form partitions between the eggs, as they are deposited within."

Fortunately in England the owner of a house has no opportunity of watching ("with an uninterrupted hum of delight, audible to a considerable distance") the operations of the carpenter bee, on the wooden beams and posts of his building.

We must now consider the ways of the wood-beetle, which will be found described in the next chapter, and only write a few words before closing this. A modern engineer is no sluggard, of that we are certain; but if he intends erecting large buildings in any of the places abroad which we have referred to, he will find it very necessary to pay particular notice of the following words of King Solomon:

"Go to the ant, thou sluggard; consider her ways, and be wise."

Proverbs vi. 6.

CHAPTER IX.

ON THE CAUSES OF DECAY IN FURNITURE, WOOD CARVINGS, ETC., AND THE MEANS OF PREVENTING AND REMEDYING THE EFFECT OF SUCH DECAY.

ALTHOUGH trunks and boxes are of themselves of little importance, they derive great consequence from the valuable deposits of written papers, deeds, books, &c., which they frequently contain, that are subject to destruction from timber-destroying insects. It is well known that the smell of Russian leather, which arises from an essential oil, is a preservative of books. Leather or woods impregnated with petroleum, or with oil of coal-tar (which has a smell not much dissimilar) would be productive of the same effect, because known to be peculiarly obnoxious to insects: these oils are, however, very inflammable.

At all times beech-wood is exposed to the attacks of beetles, and it cannot be used, even for household furniture, without being impregnated with some kind of oil or varnish, as a defence against these insects-a very curious fact, for the growing trees are remarkably free from the attacks of wood-devouring insects. Larch being solid, and its juices hot, pungent, and bitter, is rarely affected with the larvæ of insects.

Mr. Westwood, Hope Professor of Zoology, Oxford, says: "The insects which in this country are found to be

the most injurious from their habit of burrowing into the wood of furniture, belong to three species of beetles, of small size, and cylindrical in form (the better to enable them to work their way through the burrows in the wood), belonging to the family Ptinidæ, and known under the systematic names of Ptilinus pectinicornis, Anobium striatum, and Anobium tessellatum.

"In the perfect state, the insects of the genus Anobium are well known under the name of the "deathwatch," as these insects produce the ticking noise occasionally heard in old houses. It is also the Anobium striatum which is so injurious in libraries; the grub burrowing through entire volumes, and feeding upon the paper, and especially the pasted backs of the books.

"The destruction of these insects, when enclosed in articles of furniture, is by no means easy, although with care much mischief might be prevented. The saturation of the wood with some obnoxious fluid previous to its being used up in the manufacture of objects of value would be beneficial.

"A strong infusion of colocynth and quassia, spirits of turpentine, expressed juice of green walnuts, and pyroligneous acid, have all been proposed. In hot climates the ravages of the Anobium on books have been prevented by washing their backs with a fluid compound of corrosive sublimate (ten grains) and four ounces of alcohol, and the paste used in the book covers is there also mixed with alcohol."

Sir H. Davy and Professor Faraday hesitated to employ corrosive sublimate as a means of preventing the ravages

of the bookworm in Earl Spencer's library, at Althorp, not feeling certain as to whether the quantity of mercury used would affect the health of the inhabitants. Amongst all the combinations of mercury, perhaps the bi-chloride, or corrosive sublimate, is the most terrible poison. It should be remembered that there are two chlorides of mercury-one the proto-chloride, ordinarily known as calomel; the other, bi-chloride, ordinarily known as corrosive sublimate; the respective compositions of which are as follows:

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Hence the ratio of chlorine in these two chlorides is as one to two.

Botanists have long used a solution of corrosive sublimate in alcohol, known by the name of Smith's solution, to preserve the specimens in their herbaria from the aggressions of insects.

The Rev. J. Wood, writes: "I know to my cost sundry Kaffir articles being absolutely riddled with the burrows of these tiny beetles (Anobium striatum), and not to be handled without pouring out a shower of yellow dust, caused by the ravages of the larva. The most complete wreck which they made was that of a New Guinea bow, which was channelled from end to end by them, and in

* 'Insects Abroad.' By the Rev. J. Wood. 1874. London.

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