of simple alimentary substances, &c. 369 
organized substances so far, as to confine my attention at 
present to those substances in which the first peculiarity 
above mentioned exists ; and as sugar, on account of its 
crystalline form, appears to constitute the most perfect and 
definite of these substances, I have thought it best entitled to 
give a name to the whole class, or family, and hence have 
included, under the term saccharine principle, all those sub- 
stances, whatever their sensible properties may be, into the 
composition of which the hydrogen and oxygen enter in the 
proportions in which they form water. Now it will be found, 
that the substances thus constituted may generally be em- 
ployed as aliments, and as they are chiefly derived from the 
vegetable kingdom, they may be considered as representing 
vegetable aliments, properly so called ; hence, saccharine 
principle and vegetable aliment may be regarded as synony- 
mous terms, and they will be so employed throughout the 
present inquiry. 
As a subject of general interest to chemists, as well as of 
considerable importance in the present inquiry, I shall also 
attempt to investigate the composition of a few of the com- 
pounds of the saccharine principle with oxygen, or what are 
usually denominated the vegetable acids. 
Of Sugars. 
Many analyses of sugar have been -published by different 
chemists, no two of which agree with each other. These 
discrepances have doubtless arisen from various causes, 
though one cause has probably been some real or accidental 
difference in the composition of the sugars employed.* How 
* Some years ago I published an analysis of sugar, in which the proportions of 
carbon to water were stated to be to one another as 40 : 60. I was not aware at 
MDCCCXXVII. 3 B 
