694 Rural School Leaflet. 



there is a deficiency in lime due to improper feeding. Jn this case the 

 eggs are not Hkely to hatch well or to produce strong chickens if they 

 should hatch. Only eggs that are perfect in size, shape, color, and 

 texture which is characteristic of the breed should be used for hatching 

 purposes. A hen is likely to produce eggs zvliich in every respect are 

 similar to the egg from zvhich she herself zvas hatched. 



(d) The kinds of eggs laid by the different species, breeds, and 

 varieties. 



Cover the label which tells the kind of fowl which laid the tgg and 

 give each egg a number. 



Hand each pupil a jjaper on which to write the number of each egg 

 and the name of the fowl that laid it. The papers can then be cor- 

 rected by permitting the pupils to exchange papers and mark " correct " 

 or " incorrect '" as the teacher holds up the egg to the class and gives the 

 name of the fowl that laid it. 



Lesson XIII. 



PLANT-FOOD. 



G. F. Warren, 



Object. — To give a preparatory lesson so that the class will be able to 

 understand questions about food for plants, animals, and man. In suc- 

 ceeding lessons the relationship to legumes will be shown. 



Points in this lesson must necessarily be told to the pupils by the 

 teacher. It is, perhaps, a little difficult, but just this kind of information 

 is commonly discussed by farmers, and is of great importance in their 

 business. 



By chemical analyses, it has been found that all the dift'erent sub- 

 stances in the world can be separated into about seventy different things. 

 These are called elements^ because no chemist has ever' been able fur- 

 ther to separate them. Carbon, hydrogen, oxygen, nitrogen, sulfur, gold, 

 silver, copper, tin, and lead are all elements. For example, gold can- 

 not be separated into anything but gold, neither can any two or more 

 things be united to make gold, b'or centuries men have tired to make 

 gold of other things, but they have always failed. Water is not an 

 element. It is formed of the union of elements. It is a compound. 

 A chemist can easily separate water into two gases, hydrogen and oxygen. 

 and when the gas hydrogen burns, water is formed. Likewise, carbon 

 dioxid can be separated into carbon and oxygen; and when tlic carbon in 

 coal or wood burns, it forms carbon dioxid (carbonic acid gas). Similarly 

 when we breathe, the carbon of our bodies unites witli tlie o.xygen which 

 we breathe and carbon dioxid is formed. Soot is nearly pure carbon 

 that was cooled and so prevented making a union with oxygen. 



Carbon dioxid does not look anything like carbon nor is hydrogen 

 anything like water. The only way that we can tell that water is com- 



