Elements of the theory and practice of cookery

C. Boil some of the salt solution till the water is all gone ; taste the residue, and tell what it is.i 1 Sugar cannot be recovered from solution by boihng in the open air ; it burns before it becomes solid. It may be recovered by crystal- lization, which we shall learn about in Chapter IX. PREPARATORY LESSONS 25 43. Pure water ; impurities, organic and inorganic. — Clean water is colorless, odorless, and nearly taste- less. Its slight taste comes from various substances dissolved in it. One of these is air. If a glass of water stands until the air in it appears in bubbles on the glass, it is found to taste "flat." Absolutely pure water has no taste. Such water is not found in nature. That most nearly pure is the rain-water that falls dur- ing the latter part of a shower. The first rain to fall carries down with it dust and other impurities from the air. As water flows over or soaks through the ground, it dissolves a good deal of inorganic or mineral matter, with some that is organic, that is of plant or animal origin. 44. Living things, plants or animals, differ from lifeless things, in being able to feed, grow, and reproduce them- selves. Organs were once supposed to be necessary for these acts; and, in consequence, things once part of an animal or a plant, as well as things actually alive, were termed organic. Though we now know that some tiny living things have no organs, we still use the words organic and inorganic to distinguish these two kinds of matter. Examples of inorganic matter : water, sand, carbon dioxide. Examples of organic matter : wood, perspiration, leaf -mould, manure. 45. Soft water best for cleaning and cooking. — Neither dirt nor soap dissolves readily in hard water. The latter forms with it a curdy substance. For cleaning and laundry purposes hard water should be softened by the addition of washing soda or ammonia. A moderate degree of hardness does not injure water for drinking 26 THEORY AND PRACTICE OF COOKERY purposes. As a rule soft water is desirable for cooking, especially when the object is to draw out flavor or nourishment from food, as in making soup or tea. 46. Drinking water should be pure. — Much organic matter in drinkins^ water makes it unwholesome, and Fig. 3. 4? = cesspool into which drain empties. W= well into which contents of cesspool run through layers of sand and gravel. may make it dangerous. Most objectionable of organic impurities is sewage, which is likely to contain disease germs. Wells are often dug for convenience near houses. Figure 3 sIioavs how such a well may be pol- luted by house and stable waste. Fortunately, polluted water tends to become purer by filtering through the ground, and by running over its surface where air can reach it. Spring water and water from artesian wells is usually pure. City water, if not from pure sources, should be PREPARATORY LESSONS 27