Chemical Science. 485^ 



24. Composition of Vegetable proximate Principles. — M. Marcet 

 has analysed several vegetable substances by means of oxide of 

 copper, and finds them to have the following composition : — 



Roasted starch, or artificial gum — 



Carbon 35.7 



Oxygen. 58.1 



Hydrogen 6.2 



Ordinary Starch — Carbon 43.7 



Oxygen 49.7 



Hydrogen 6.6 



It appears, therefore, that roasted starch contains much more 

 oxygen and less carbon than common starch. The quantity of 

 hydrogen is also increased. 



Starch obtained from malt gave — 



Carbon. ...... .41.6 



Oxygen. .1 .... 51.8 



Hydrogen 6.6 



Hordein— Carbon 44.2 



Oxygen 47.6 



Hydrogen 6.4 



Nitrogen 1.8 



The parenchyma of the potato gave — 



Carbon 37.4 



Oxygen 58.6 



Hydrogen. ..... 4.0 



Gluten — Carbon 55.7 



Oxygen 22.0 



Hydrogen 7.8 



Nitrogen 14.5 



Zimoma did not appear to differ from common gluten. 



Yeast— Carbon 30.5 



Oxygen 57.4 



Hydrogen 4.5 



Nitrogen 7.6 — Geneva Memoir es, 



25. On Legumiiie, a particular Vegetable Principle, 6y M. H 

 Braconnot. — Dry ripe peas, being left for some hours in warm 

 water to soften, were made into a paste in a mortar with water ; 

 and being diffused through more of that fluid, were passed through 

 a sieve : the milky fluid produced being allowed to stand, deposited 

 the starch, the legumine being retained in solution apparently 

 by a vegetable acid. Being evaporated, the legumine separated 

 in successive transparent slightly-soluble pellicles. Thus obtained, 

 it was impure, and of a greenish colour; but being washed with 

 boiling alcohol, the green colour was removed, and the legumine 

 obtained perfectly pure and white; it was now as finely divided 

 as starch, and, when dried, appeared semi-transparent. 



