337 
the nests of the Java swallow. 
sist of a substance having properties intermediate between 
gelatine and albumen. It resists for a considerable time the 
action of warm water, but after some hours enlarges and 
softens ; upon drying, it again resumes its former appearance 
and properties, becoming somewhat more brittle than before, 
probably, in consequence of having lost a very small portion 
of gelatine, which delicate tests discover in the water. 
In the diluted acids, this substance dissolves with more ease 
than coagulated albumen ; in the concentrated acids, its pro- 
perties are nearly the same as those of coagulated white of 
With the caustic and subcarbonated fixed alcalis, it forms 
saponaceous compounds, which are decomposed by the acids 
with the same appearances as other albuminous soaps. It 
readily dissolves in liquid ammonia, and in the solution of 
subcarbonate of ammonia, circumstances in which it differs 
from albumen. When submitted to destructive distillation, 
a relatively small portion of ammonia is formed, and the re- 
maining coal is easy of incineration, circumstances which like- 
wise lead to point out a distinction between this substance and 
albumen. 
Explanation of Plate XVI. 
Fig. l. The gizzard and part of the gullet of the Java 
swallow slit up and laid open, magnified twice in diameter, 
or 4 times in superficies. 
Fig. 2. A small portion of the lowermost part of the gullet, 
magnified 15 times in diameter, or 225 times in superficies. 
Fig. 3, 4, and 5. Side view of the glands of different sizes. 
Fig. 6 . Perpendicular section of Fig. 5. 
