_ also in Acorns, Chestnuts, and many other seeds. It is very 
166 VEGETABLE COMPOUNDS. 
CHAP. V._VEGETABLE COMPOUNDS WHICH d 
DO NOT BELONG TO ANY OF THE PRE- © 
CEDING CLASSES. a 
1, ALBUMEN. 
618. This substance in the vegetable kingdom resembles, 
in composition and properties, that which exists in animal 
compounds. The purest albumen is the white of the egg. 
In the juice of the Papaw tree (Carica papaya) it exists in 4 
considerable quantity. When the juice is boiled, the albu- 
men becomes coagulated, and is deposited. It has been 
found in large quantities in the fruit of the Ochra (Hibiscus 
esculentus). Care must be taken to distinguish between the : 
chemical use of the term ‘‘ Albumen,” as applied to express — 
a peculiar compound, and its botanical use as applied to . 
particular part of the seed. The part called the “ Albumen’ 
in Wheat contains little or no albumen. 
2. GLUTEN. 
619. This is a soft substance, much resembling dough. 
It is obtained from wheat-flour, by forming it into a paste, 
and washing it by exposing it to a small stream of water. 
The starch, mucilage, &c. are carried away by the water, 
and the gluten remains. It exists largely in the seedsof the 
Grasses. Wheat contains from one-fourth to one-fifth of 
gluten, and hence its superiority for the manufacture of 
sbread. It is the gluten which produces the fermentation ae 
the dough, by which the bread is raised, causing those inter- 
stices seen in every part. The yeast added is for the put — 
pose of assisting and hastening the fermentation. It is found 
