COMPOSITION OF THE SEED. 25 
becomes what, in the language of the kitchen, is 
called dough. Taking this and working it between 
the fingers under a little stream of water for some 
time, at length we obtain a sticky substance like 
bird-lime,—this is gluten. And if we collected 
the water after washing the lump of dough in it, 
we should find it quite milky, and that soon a 
white powder would settle at the bottom,—this 
powder is starch.* This simple and easy experi- 
ment or analysis, then, tells us in unmistakable 
language what enters into the composition of a 
seed, so far as its first constituents are concerned; 
but it would require the most profound know- 
ledge of chemistry, and the most delicate and 
costly apparatus to find out what these three 
ingredients were made of. This has, however, 
been done, and the result is given in the four 
words abovementioned. 
Here then is the preliminary chemistry of a 
seed; let us now see what happens when we put 
it in such a position as that it shall be supplied 
with moisture, air, and warmth. If we go toa 
* The starch sold in the shops is procured by a process similar to 
this, principally from potatoes. 
