94 APPENDIX. 



19. The following table should be printed on paste- 

 board, and suspended on the wall of the school-room, or 

 written legibly on the black-board : 



72 Ibs. of woody fibre contain carbon 36 Ibs., water 36 Ibs. 

 81 Ibs. of dry starch or gum contain carbon 36 Ibs., water 45 Ibs. 

 85^ Ibs. of loaf-sugar contain carbon 36 Ibs., water 49 Ibs. 

 63 Ibs. of humic acid contain carbon 36 Ibs., water 27 Ibs. 



Let the teacher direct attention to the fact that these 

 very different appearing substances all contain the same 

 elements ; that hi the quantities designated they all 

 contain thirty-six pounds of carbon, but that the hydro- 

 gen and oxygen, in the form of water, differs in quantity 

 in each. 



20. Let the teacher remark the difference between 

 elementary and compound bodies. Compound bodies- 

 can be divided into two or more elementary bodies. 

 Thus starch may be divided into carbon, hydrogen and 

 oxygen ; but these elements cannot be again subdivided, 

 or decomposed into other bodies. "Water is a compound 

 body, containing hydrogen and oxygen. Carbonic acid 

 contains carbon and oxygen. The air we breathe con- 

 tains nitrogen and oxygen. He may add to these illus- 

 trations ad libitum. 



21. (See Fig. 15.) Explain the meaning of the word 

 carbonaceous, and refer again to the organic and inor- 

 ganic forms of matter. 



22. The words dissolve and solution should be practi- 

 cally illustrated. Dissolve some salt and sugar in a 



