112 TEACHING SCIENCE IN SECONDARY SCHOOLS


my number into the number of students you expect to have,
you will know how many of each article are needed.

 List A. Apparatus Used Constantly:
 By students:
 No. OF
 STUDENTS
 SERVED Articles
 (1) Six test tubes, 125x15 mm. (5x% in.).
 (1) Two beakers, 150 ml. (c. c.).
 (2) Alcohol lamp.
 (2) Evaporating dish, porcelain, 80 mm. (3 in.).
 (2) Gauze, iron wire, 4x4 in.
 (2) Ring stand, with one 4-inch ring.
 (2) Granite-ware pan, 8 inches across and 2 inches or more deep.

 For teacher's demonstration, and general use:
 Two boxes each, Dennison's labels, No. 201 and 223.
 One gross (144) corks, to fit test tubes (No. 5).
 Two files, rat-tail; two files triangular (6 in.).
 One dozen packets of filter paper, 9 cm. (3 /2 in.).
 One pound of glass tubing, 7 mm. ('4 in.) outside diameter.

 Improvise these items (and many others):
 (1) Test-tube holders of folded paper.
 (1) Test-tube brushes; bits of cloth tied on a pencil.
 (1) Test-tube racks; stand tubes in drinking glasses.
 (1) Three plates of glass (3x3 in.).
 (1) Two wide-mouth and two narrow-mouth bottles.
 (1) Sand bath; a pie tin.
 One condenser, made from iron pipe, stoppers, and glass tubes.
 Cork borers; a hot nail will serve.

 List B. Apparatus Used Frequently:
 By students:
 No. OF
 STUDENTS
 SERVED Articles
 (2) Flask, Erlenmeyer, 250 ml. (c. c.).
 (2) Funnel, glass, 80 mm., 3 in. diameter.
 (2) Funnel tube, thistle top, V/ in. diameter tube.
 (2) One foot of rubber tubing, 4 in. inside diameter.
 (5) Graduated cylinder, 50 ml.
 (5) Mortar and pestle, of porcelain or glass, 80 mm. (3 in.).