Sugar is not a synthetic product and the business of the chemist has been merely to extract and purify it.  But this is not so simple as it seems and every sugar factory has had to have its chemist.  He has analyzed every mother beet for a hundred years.  He has watched every step of the process from the cane to the crystal lest the sucrose should invert to the less sweet and non-crystallizable glucose.  He has tested with polarized light every shipment of sugar that has passed through the custom house, much to the mystification of congressmen who have often wondered at the money and argumentation expended in a tariff discussion over the question of the precise angle of rotation of the plane of vibration of infinitesimal waves in a hypothetical ether.

The reason for this painstaking is that there are dozens of different sugars, so much alike that they are difficult to separate.  They are all composed of the same three elements, C, H and O, and often in the same proportion.  Sometimes two sugars differ only in that one has a right-handed and the other a left-handed twist to its molecule.  They bear the same resemblance to one another as the two gloves of a pair.  Cane sugar and beet sugar are when completely purified the same substance, that is, sucrose, C_{12}H_{22}O_{11}.  The brown and straw-colored sugars, which our forefathers used and which we took to using during the war, are essentially the same but have not been so completely freed from moisture and the coloring and flavoring matter of the cane juice.  Maple sugar is mostly sucrose.  So partly is honey.  Candies are made chiefly of sucrose with the addition of glucose, gums or starch, to give them the necessary consistency and of such colors and flavors, natural or synthetic, as may be desired.  Practically all candy, even the cheapest, is nowadays free from deleterious ingredients in the manufacture, though it is liable to become contaminated in the handling.  In fact sugar is about the only food that is never adulterated.  It would be hard to find anything cheaper to add to it that would not be easily detected.  “Sanding the sugar,” the crime of which grocers are generally accused, is the one they are least likely to be guilty of.

Besides the big family of sugars which are all more or less sweet, similar in structure and about equally nutritious, there are, very curiously, other chemical compounds of altogether different composition which taste like sugar but are not nutritious at all.  One of these is a coal-tar derivative, discovered accidentally by an American student of chemistry, Ira Remsen, afterward president of Johns Hopkins University, and named by him “saccharin.”  This has the composition C_{6}H_{4}COSO_{2}NH, and as you may observe from the symbol it contains sulfur (S) and nitrogen (N) and the benzene ring (C_{6}H_{4}) that are not found in any of the sugars.  It is several hundred times sweeter than sugar, though it has also a slightly bitter aftertaste.  A minute