Third, The leaves and sheaths are separated from the cut cane by fanning mills.
Fourth, The cleaned cane is cut into fine bits called chips.
Fifth, The chips are placed in iron tanks, and the sugar "diffused," soaked out with hot water.
Sixth, The juice obtained by diffusion has its acids nearly or quite neutralized with milk of lime, and is heated and skimmed.
Seventh, The defecated or clarified juice is boiled to a semi-sirup in vacuum pans.
Eighth, The semi-sirup is boiled "to grain" in a high vacuum in the "strike pan."
Ninth, The mixture of sugar and molasses from the strike pan is passed through a mixing machine into centrifugal machines which throw out the molasses and retain the sugar.
The process of the formation of sugar in the cane is not fully determined, but analyses of canes made at different stages of growth show that the sap of growing cane contains a soluble substance having a composition and giving reactions similar to starch. As maturity approaches, grape sugar is also found in the juice. A further advance toward maturity discloses cane sugar with the other substances, and at full maturity perfect canes contain much cane sugar and little grape sugar and starchy matter.
In sweet fruits the change from grape sugar to cane sugar does not take place, or takes place but sparingly. The grape sugar is very sweet, however.
Cane sugar, called also sucrose or crystallizable sugar, when in dilute solution is changed very readily into grape sugar or glucose, a substance which is much more difficult than cane sugar to crystallize. This change, called inversion, takes place in over-ripe canes. It sets in very soon after cutting in any cane during warm weather; it occurs in cane which has been injured by blowing down, or by insects, or by frost, and it probably occurs in cane which takes a second growth after nearly or quite reaching maturity.