110 
limited, and in this place it would be improper to 
dwell upon peculiarities ; my object being to offer 
such general views of the constitution of vegetables 
as may be of use to the agriculturist. It is proba- 
ble, from the taste of sarcocol, that it is gum com- 
bined with a little sugar. Inulin is so analogous 
to starch, that it may be a variety of that principle. 
If slight differences in chemical and physical pro- 
perties be considered as sufficient to establish a 
difference in the species of vegetable substances, 
the catalogue of them might be enlarged to almost 
any extent. No two compounds procured from 
different vegetables are precisely alike ; and there 
are even differences in the qualities of the same 
compound, according to the time in which it has 
been collected, and the manner in which it has 
been prepared. The great use of classification in 
science is to assist the memory, and it ought to 
be founded upon the similarity of properties which 
are distinct, characteristic, and invariable. 
The analysis of any substance, containing mix- 
tures of the different vegetable principles, may be 
made, in such a manner as is necessary for the 
views of the agriculturist, with facility. A given 
quantity, say 200 grains, of the substance should 
be powdered, made into a paste or mass, with a 
small quantity of water, and kneaded in the hands, 
or rubbed in a mortar for some time under cold 
water: if it contain much gluten, that principle 
will separate in a coherent mass. After this pro- 
cess, whether it has afforded gluten or not, it 
should be kept in contact with half a pint of cold 
water for three or four hours, being occasionally 
