WHAT IS DIFFUSION?
The condition in which the sugars and other soluble substances exist in the cane is that of solution in water. The sweetish liquid is contained, like the juices of plants generally, in cells. The walls of these cells are porous. It has long been known that if a solution of sugar in water be placed in a porous or membraneous sack, and the sack placed on water, an action called osmosis, whereby the water from the outside and the sugar solution from the inside of the sack each pass through, until the liquids on the two sides of the membrane are equally sweet. Other substances soluble in water behave similarly, but sugar and other readily crystallizable substances pass through much more readily than uncrystallizable or difficultly crystallizable. To apply this properly to the extraction of sugar, the cane is first cut into fine chips, as already described, and put into the diffusion cells, where water is applied and the sugar is displaced.
