In the fermentation process for making alcoholic liquors a little glycerin is produced as a by-product.  Glycerin, otherwise called glycerol, is intermediate between sugar and alcohol.  Its molecule contains three carbon atoms, while glucose has six and alcohol two.  It is possible to increase the yield of glycerin if desired by varying the form of fermentation.  This was desired most earnestly in Germany during the war, for the British blockade shut off the importation of the fats and oils from which the Germans extracted the glycerin for their nitroglycerin.  Under pressure of this necessity they worked out a process of getting glycerin in quantity from sugar and, news of this being brought to this country by Dr. Alonzo Taylor, the United States Treasury Department set up a special laboratory to work out this problem.  John R. Eoff and other chemists working in this laboratory succeeded in getting a yield of twenty per cent. of glycerin by fermenting black strap molasses or other syrup with California wine yeast.  During the fermentation it is necessary to neutralize the acetic acid formed with sodium or calcium carbonate.  It was estimated that glycerin could be made from waste sugars at about a quarter of its war-time cost, but it is doubtful whether the process would be profitable at normal prices.

We can, if we like, dispense with either yeast or bacteria in the production of glycerin.  Glucose syrup suspended in oil under steam pressure with finely divided nickel as a catalyst and treated with nascent hydrogen will take up the hydrogen and be converted into glycerin.  But the yield is poor and the process expensive.

Food serves substantially the same purpose in the body as fuel in the engine.  It provides the energy for work.  The carbohydrates, that is the sugars, starches and celluloses, can all be used as fuels and can all—­even, as we have seen, the cellulose—­be used as foods.  The final products, water and carbon dioxide, are in both cases the same and necessarily therefore the amount of energy produced is the same in the body as in the engine.  Corn is a good example of the equivalence of the two sources of energy.  There are few better foods and no better fuels.  I can remember the good old days in Kansas when we had corn to burn.  It was both an economy and a luxury, for—­at ten cents a bushel—­it was cheaper than coal or wood and preferable to either at any price.  The long yellow ears, each wrapped in its own kindling, could be handled without crocking the fingers.  Each kernel as it crackled sent out a blazing jet of oil and the cobs left a fine bed of coals for the corn popper to be shaken over.  Driftwood and the pyrotechnic fuel they make now by soaking sticks in strontium and copper salts cannot compare with the old-fashioned corn-fed fire in beauty and the power of evoking visions.  Doubtless such luxury would be condemned as wicked nowadays, but those who have known the calorific value of corn would find it hard to abandon it altogether, and I fancy that the Western farmer’s wife, when she has an extra batch of baking to do, will still steal a few ears from the crib.