“How beautifully,” exclaimed Emile, “those grains of starch are arranged in their little cubby-hole! They might be taken for a nest of eggs. And you say there are heaps and heaps of these little starch cells?” [[96]]
“Yes, my boy; in a medium-sized potato they could be counted by millions and millions.”
“It must be rather a curious sight to look at a little piece of potato through a powerful magnifying-glass.”
“It is indeed one of the most curious sights, this countless multitude of starch grains, all the same shape, all white as snow, gathered together by tens, dozens, scores, and even more, in their delicate little box-like cells.
“Let us perform an experiment not beyond our means; let us remove the starch from a potato. All we need to do is to tear open the cells in order to liberate the starch grains, and then filter them out. Watch me do it. With a kitchen grater I reduce the potato to pulp and thus tear the cells open. Now I put the pulp on a piece of linen over a large glass and pour a little water through it with one hand while with the other I keep stirring the pulp. The grains of starch from the ruptured cells are washed away by the water and carried through the meshes of the fabric, while the remnants of the cell-walls, being too large to pass through, stay behind in the filter.
“Thus I obtain a glassful of turbid water. Look at it under a bright sun. In the water a multitude of white satiny specks are falling like so much snow and piling up on the bottom. In a few moments the deposit has settled. I then throw away the clear water above it and have left a powdery substance, magnificently white, which if pressed between the [[97]]fingers creaks like fine sand. It is the starch of the potato, and is made up of such fine grains that it would take from one hundred and fifty to two hundred to equal the head of a pin in size. Nevertheless these grains, minute though they are, have a very complicated structure, each one of them being composed of a large number of tiny leaflets folded one over another. The picture I showed you just now will serve to give you an idea of these superposed leaflets that go to make, all together, a single grain. Now if some of this starch is boiled in a little water, the successive leaflets of the grain open and separate, and the whole becomes an unctuous jelly far exceeding in volume that of the starch used.”
To prove this assertion, Uncle Paul proceeded to heat in a little water the starch taken from the potato, and soon the powdery matter was reduced to a beautiful pellucid jelly. [[98]]