the exterior frame-work is similar to the white nests, which have no lining whatever. We have no means of explaining this singular anomaly *.

The white nests appear to consist chemically of a substance intermediate between gelatine and albumen. Neither the analytical experiments of Dobereiner or Brande indicate it to be of animal origin, but to be more allied to the vegetable gums, as it is incinerated with difficulty, and contains only a small portion of ammonia.

66

The commercial history of these singular nests is much better understood than their composition, in consequence of their reputed virtue as a restorative. The best account of them which we have met with is given by Mr. Crawfurd. "The best nests," he says, are those obtained in deep, damp caves, and such as are taken before the birds have laid their eggs. The coarsest are those obtained after the young have been fledged. The finest nests are the whitest; that is, those taken before the nest has been rendered impure by the food and fæces of the young birds. The best are white, and the inferior dark-coloured, streaked with blood, or intermixed with feathers. It may be remarked, however, that some of the natives describe the purer nests as the dwelling of the cock-bird, and always so designate them in commerce. Birds' nests are collected twice a-year; and, if regularly collected, and no unusual injury be offered to the caverns, will produce very equally, the quantity being very little, if at all, improved by the caves being left altogether unmolested for a year or two. Some of the caverns are extremely difficult of access, and the nests can only be collected by persons accustomed from their youth to the office. The most remarkable and productive

* J. R.

to association, for they seldom sing but in fine weather and when pleased; and, for the latter reason, even the sostenuto purring of the cat is not unpleasing. The variety and rapidity of their notes and intonation also awaken attention, and the contrast in their song between rapid flights of double-demisemi-quavers and lengthened and sweet minims, is often wonderful; as in the case of the soft and sustained notes of the nightingale, succeeded by a short and expressive passage of quicker sound.

It is, no doubt, too much to say that we have borrowed all our music from birds, but some of it may, without much stretch of fancy, be considered as having been stolen from that source; for example, the following*:

are more valuable than their weight in silver. Of the quantity of birds' nests exported from the Indian islands, although we cannot state the exact amount, we have data for hazarding some probable conjectures respecting it. From Java there are exported about 200 piculs, or 27,000 lbs., the greater part of which is of the first quality. The greatest quantity is from the Suluk Archipelagos, and consists of 530 piculs. From Macassar there are sent about 30 piculs of the fine kind. These data will enable us to offer some conjectures respecting the whole quantity; for the edible swallows' nests being universally and almost equally diffused from Junk, Ceylon, to New Guinea, and the whole produce going to one market, and only by one conveyance, the junks, it is probable that the average quantity taken by each vessel is not less than the sum taken from the ports just mentioned. Taking the quantity sent from Batavia as the estimate, we know that this is conveyed by 5,300 tons of shipping, and, therefore, the whole quantity will be 1,818 piculs, or 242,400 lbs., as the whole quantity of Chinese shipping is 30,000 tons. In the Archipelago, at the prices already quoted, this property is worth 1,263,519 Spanish dollars, or 284,2901. The value of this immense property to the country which produces it, rests upon the capricious wants of a single people. From its nature, it necessarily follows that it is claimed as the exclusive property of the sovereign, and everywhere forms a valuable branch of his income, or of the revenue of the state. This value, however, is, of course, not equal; and depends upon the situation and the circumstances connected with the caverns in which the nests are found. Being often in remote and sequestered situations, in a country so lawless, a property so valuable and exposed is subject to the perpetual depredations of freebooters; and it not

for, about Selborne wood, he found they were mostly in D; he heard two sing together, the one in D, and the other in D sharp, which made a disagreeable concert; he afterwards heard one in D sharp, and about Wolmer Forest, some in C. As to nightingales, he says that their notes are so short, and their transitions so rapid, that he cannot well ascertain their key. Perhaps in a cage or in a room their notes may be more distinguishable. This person has tried to settle the notes of a swift, and of several other small birds, but cannot bring them to any criterion*.*

It is singular that scarcely any large bird is known to sing, though the crowing of the cock in the morning may perhaps, without much impropriety, be called singing. We have also observed that the crow (Corvus cornix) is sometimes heard in a calm morning to utter a peculiar plaintive note, very different indeed from its usual croaking, and characterized by an ascending minor third, slurred, not staccatoed, like the descending minor third of the cuckoo t. Some are disposed to consider the cawing of rooks a species of song highly grateful, from its rural associations. "The rook," says Bingley, "has but two or three notes, and when he attempts a solo, we cannot praise his song; but when he performs in concert, which is his chief delight, these notes, although rough in themselves, being intermixed with those of the multitude, have, as it were, all their rough edges worn off, and become harmonious, especially when softened in the air, where the bird chiefly performs. We have this music in perfection, when the whole colony is raised by the discharge of a gun ." The chanting falcon (Accipiter musicus, DAUDIN), however, is a more decided exception to the general rule, * Hist. of Selborne, lett. 45.

Anim. Biogr. ii. 249.

J. R.

the male, according to M. Vaillant, being remarkable for its song, which it utters every morning and evening, and not uncommonly continues it the whole night. Each strain is continued in a loud tone for more than a minute, and after a pause it begins anew. While it

is singing, it is so regardless of its own safety, that any one may approach very near it, but at other times it is suspicious, and takes flight on the slightest alarm*.

Another still more remarkable exception might be adduced in the instance of the swan, the largest of singing-birds, according to Albertus Magnus †, could we set down as facts all that has been said of it, not only by poets but by philosophers and naturalists. * Oiseaux d'Afrique, i. 120. +Apud Aldrovandi Ornith, iii. 2.