Yeast is a vegetable. Strange as it may seem, yeast is a tiny fungus growth, though it takes a microscope to see it. In brewing (particularly with hops), in wine-making and in any other process of fermentation where the liquid contains some sugar and some albuminous matter, the clear liquid becomes “muddy.” Then the minute things that made it muddy collect into a foaming, bitter mass which is yeast. This yeast has the power of setting up fresh fermentation when put with other things. It is fermentation that makes bread-dough “raise.” Oh, yes, there is alcohol in bread-dough, but it doesn’t stay there. As I told you last month, 12,000,000 gallons of alcohol are made and lost in bread-making every year in Germany alone! Some day scientists will learn how to save it. _Hops_ We generally think of hops when yeast is mentioned. I wish any of you who can tell us the story of hops would send it in to our Department. _Salt_ How could we cook, or eat, or live without salt? It is an absolute necessity for people and animals. Also, it is very valuable as a fertilizer, and was used as such centuries and centuries ago by the Hindoos and Chinese. Further than this, soda is derived from salt, and as soda is necessary in making both glass and soap, these two useful things could not be made if it were not for salt. Most of our modern textile fabrics are more or less dependent on chlorine, which is made from salt. We all know how valuable salt is as a preservative for butter, meats and other animal food, and now they are learning a way to preserve timber with it. We know, too, its use in freezing ice cream, but may not realize how much it is used for refrigerating other things. In short, even if we could live at all without it, life would be pretty miserable. The chemists call salt _chloride of sodium_ and use this symbol for it—Na Cl, which shows what it is composed of, but doesn’t mean anything to me. We get salt in three ways—from rock-salt mines, from natural brine springs and from evaporating sea water. The world’s biggest rock-salt mines are in Gallicia, upper Austria, Bavaria, Hungary, Transylvania, Wallachia; at Vic and Dienze, France; at Bix, Switzerland; at Cadrona, Spain, and at Cheshire, England. That at Wieliczka in Gallicia is a mile long, three-fourths of a mile wide and over a thousand feet deep. Some of its chambers are 150 feet high—as high as a sky-scraper—and one of them is fitted up as a chapel to St. Anthony, the altar, statues and everything being solid salt. In this mine is a lake 650 feet long and 40 feet deep. There are horses there that have never seen the light of day, and men, women and children who live in salt houses and never see the outside world above their heads. It is a small village buried down under the ground. When the emperor and his family visit the mine, it is brilliantly illuminated and a grand festival is held in a great hall.