DEPARTMENTS OF SCIENCE. 11 



10. The tissues of leaves, etc., are best seen by transmitted light. They are to be di- 

 vided by the razor or scalpel into extremely thin parings or cuttings. Such cuttings may 

 be made by holding the leaf between the two halves of a split cork. They are then made 

 wet and viewed upon glass. The stomata are best seen in the epidermis stripped off; but 

 in the Sorrel-leaf (Oxalis violacea) they appear beautifully distinct upon the entire leaf. 

 ( 397, Fig. 497.) 



11. Woody tissues, etc., may be viewed either as opaque or transparent. Sections and 

 citttings should be made in all directions, and attached to the glass by water, white of 

 egg, or Canada balsam. To obtain the elementary cells separately for inspection, the 

 fragment of wood may be macerated in a few drops of nitric acid added to * grain of chlo- 

 rate of potassa. Softer structures may be macerated simply in boiling water. 



Jlemew of the Chapter. 1. Advantage of beginning the study in early spring. 2. Speci- 

 mens for illustration. How to obtain them in the city. 3. The herbarium. Uses of it. 

 4. Apparatus for collecting. 5. Good specimens. Secret of preparing them. 6. The 

 drying-press. 7. The use of lenses. 8. Of the microscope, etc. 



CHAPTER II. 



DEPARTMENTS OF SCIENCE. 



12. Three great departments in nature are universally recog- 

 nized, commonly called the mineral, vegetable, and animal king- 

 doms. The first constitutes the Inorganic, the other two the 

 Organic World. 



13. A mineral is an inorganic mass of matter that is, without 

 distinction of parts or organs. A stone, for example, may be 

 broken into any number of fragments, each of which will retain 

 all the essential characteristics of the original body, so that each 

 fragment will still be a stone. 



14. A plant is an organized body, endowed with vitality but 

 not with sensation, composed of distinct parts, each of which is 

 essential to the completeness of its being. A Tulip is composed 

 of organs which may be separated and subdivided indefinitely, 

 but no one of the fragments alone will be a complete plant. 



15. Animals, like plants, are organized bodies endowed with 

 vitality, and composed of distinct parts, no one of which is com- 

 plete in itself; but they are elevated above either plants or min- 

 erals by their power of perception. 



16. Physics is the general name of the science which treats of 

 the mineral or inorganic world. 



17. Zoology relates to the animal kingdom. 



