126 LABORATORY LESSONS IN GENERAL SCIENCE 



2. Carefully break a fresh egg into a clean sauce dish, and 

 note (a) the germ, and its location ; (6) the light and dark 

 parts of the yolk; (c) the chalaza (ka-la'za). 



Examine the large end of the broken shell for the air 

 space, noting the membranes inclosing it. Infer if air can 

 pass through these membranes. 



3. To a bit of the shell in a test tube add some strong acid, 

 and describe the action. Note the effect of any escaping 

 gas upon a drop of limewater. 



4. To a small piece of boiled white of egg in a dish add 

 strong nitric acid; note any color change as the acid is 

 warmed a little. 



Pour off the acid, rinse with water, and then add strong 

 ammonia water. Describe any further color change. 



These steps and their results illustrate tests for the im- 

 portant class of "food substances known as protein (pro'te-m). 

 The albumen of egg is but one of these. They are the tissue- 

 building material of our foods. 



5. Observe closely, and state the results, as the teacher 

 adds alcohol slowly to a little uncooked white of egg in a 

 test tube, shaking the tube from time to time. 



POULTRY KEEPING 



1. Aside from profit what are good reasons for keeping 

 a few fowls at one*s home? Name some classes of people 

 other than farmers who can profitably engage in the poultry 

 business on a small scale ? What traits of character are quite 

 essential in one who is to make a success of poultry raising ? 

 What is a safe course for any one beginning to keep poultry ? 



