EXPERIMENTS AND PRACTICAL WORK 75 



straining through a coarse cloth into a clean vessel, 

 and allowing to settle; weigh the dried starch. 



Weigh 1 oz. of yam, cut it into small pieces, and 

 put it into a tin partly immersed in boiling water. 

 Weigh the yam after four hours, and calculate the 

 amount of water that has been lost. 



Burn 2 oz. of yam, and observe the mineral matter, 

 or ash, that is left. 



(b) Sweet Potato. Treat an equal quantity of the 

 sweet-potato tuber in the same way. 



(c) Coin. Prepare starch, oil, and gluten from a 

 sample of native corn. Collect samples of various pre- 

 parations made from corn. 



(d) Bice. Powder 1 oz. of rice, wash in a muslin bag, 

 allowing the starch to pass into a tin in which it can 

 settle; pour off the water; dry and weigh the starch. 



(e) Beans. Dry some beans in the sun; powder and 

 mix with lime; heat and test for ammonia with mois- 

 tened litmus paper (see Experiment 1505). 



Expt. 165. Ripe and Unripe Bananas. Taste ripe 

 and unripe bananas, and record which are sweeter; find 

 out if cooking a green banana makes it taste any 

 sweeter. 



Expt. 166. Animal Foods. Collect small portions of 

 eight different kinds of animal food, e.g. milk, pork, 

 beef. Observe the extent to which fat is present in the 

 samples collected. 



THE BEST KIND OF DIET 



(See Tropical Readers, Book II, pp. 150-153.) 



Expt. 167. Too many Heat-giving Foods. Collect 

 samples of foods commonly eaten that do not contain 

 a sufficient quantity of albuminoids, e.g. yam, sweet 

 potato, bread-fruit. 



