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XXV. Some account of the nests of the Java swallow , and of 
the glands that secrete the mucus of which they are composed ’ 
By Sir Everard Home, Bart. V. P. R. S. 
Read June 26, 1817. 
The nests of a particular species of swallow which is prin- 
cipally met with in the island of Java, have from time imme- 
morial formed an article of trade between that island and 
China, where they are purchased at a high price by that 
voluptuous people, it being believed, that the materials of 
which the nests are composed., are possessed of an aphrodi- 
siac virtue in an eminent degree. They have been occasion- 
ally brought into this country, and are preserved in collections 
of natural history, as curiosities. In what manner the bird pro- 
cures the materials out of which the nest is made, has till now 
remained unknown ; a thousand conjectures have, how- 
ever, been made upon this subject. It has been supposed by 
some, that it is a gluten collected from the mollusca picked 
upon the surface of the sea. By others, a substance extracted 
from certain fuci found on the sea shore. By others again, 
a portion of the food in a half digested state regurgitated 
to be employed for this particular purpose. Sir Stamford 
Raffles, who has just returned from Java, where he resided 
five years, as lieutenant governor, has brought over a num- 
ber of these nests, and has been kind enough to offer me 
some of them, for the purpose of investigating the nature of 
