EXTENSION COURSE IN VEGETABLE FOODS. 7 



Mineral matter {ash). — In most vegetables the percentage of ash 

 is higher than in grains. When one notes the small bit of ash remain- 

 ing after food is burned and considers that it contains calcium, iron, 

 potassium, sulphur, etc., one realizes how small an amount of each 

 must be present. Still, these minute quantities, often barely 1 per 

 cent of the total weight of the food, are essential to health. Mineral 

 matters obtained from such foods are considered much more useful to 

 the body than when taken in the form of " spring medicines." 



Fat. — Comparatively few common vegetables contain enough fat 

 to show readily. Xuts, such as pecans and coconuts, and seeds, such 

 as cottonseed, peanuts (a beanlike seed commonly called a nut), and 

 corn, and such fruits as the olive and avocado, or alligator pear, may 

 yield a considerable amount. The lack of fats in most vegetables 

 justifies the common habit of using cream, butter, or table oil with 

 them, or of eating them with meat which usually contains consider- 

 able fat. 



Protein. — Except for the legumes, vegetables contain too little pro- 

 tein to be detected by simple experiments. From the point of view of 

 dietetics this is not significant, for vegetables are commonly eaten 

 with meat and milk products which supply protein. 



Carbohydrates. — As a class vegetables are rich in carbohydrates. 

 Starch, cellulose (the woody fiber which forms the basis of all plant 

 structures), and sugar are usually all present. Though the amount 

 of sugar is usually small, its presence is shown by the sweet taste of 

 squash, young peas, and green corn. 



EXERCISES, LESSON I. 



Materials needed. — Test tubes, paper, cheesecloth, wire strainer, filter paper, 

 alcohol lamp or Bunsen burner ; a few each of large seeds, such as corn, squash, 

 beans, peas, nuts ; ripe olives ; onions and other bulbs ; potatoes, beets, carrots, 

 and piece of squash ; small quantities of iodin, ether, nitric acid. 



If possible, show the general structure of plants, by pictures or lantern slides 

 or under the microscope. 



COMPOSITION OF FOODS. 



Water and mineral matter. — Weigh a small portion of a vegetable, slice thin 

 or grate, spread on a shallow dish, and set to dry in the oven with the door 

 open, on the back of the stove, in the uncovered part of a double boiler, or in 

 the sunlight in a current of air. Weigh after 1 hour, again after 24 hours. 



Soak dried fruit or vegetables, measure and weigh before and after soaking 

 and reckon the percentage of water absorbed. 



Burn any vegetable substance on a clean surface which can be made very 

 hot ; the ash left after all charcoal disappears is the mineral matter. In the 

 laboratory small dishes called crucibles are used for this purpose, but small 

 tin covers make convenient substitutes. 



