ARTICLES OF EXPORTATION. 431 would be useless to dwell upon conjectures respect- ing the nature of the substance which composes the nest. In shape the nest is like that of an or- dinary swallow's nest, and in external appearance as well as consistence, somewhat resembles a fibrous ill- concocted isinglass. The nests of all the swal- low tribe in these countries are more or less form- ed of this singular substance. The common house martin, as I have a thousand times seen, constructs its nest partly of this substance, and partly of the ordinary materials of birds' nests, hair, straws, fea- thers, &c. These, however, are of no value. The esculent nest is always the produce of the swallow that builds in the caves of rocks, at a distance from the habitation of man. The caves where these nests are found are frequently, but not al- ways, on the sea-side. In Java, very productive caves are found in the interior of the country, and at least fifty miles from the sea. It seems proba- ble that they are most abundant on the sea-side only, because caverns are there most frequent, and least liable to disturbance. This seems to prove that sea foam, or other marine production, has no share in the formation of the nest ; and the most probable hypothesis is, that the nest is a material elaborated from the food of the bird, a conjecture which would be proved if, on a skilful dissection, it were discovered, that the bird has any peculiar or- gans destined to perform such a process. The natives
