TEACHING SCIENCE IN SECONDARY SCHOOLS


 'One large funnel, 200 mm. (8 in. in diameter).
 Two evaporating dishes, porcelain (6 in.).
 Six more magnifying glasses (hand lens type).
 Copper water bath, 6 in., with rings.
 One iron mortar, 6 in,, with pestle.
 One trip scales, laboratory type, with rider.
 Six each of 1-inch, 2-inch, and 6-inch iron rings for stand.
 Standard articles.for many of those you have improvised.
 Breakage in the laboratory must be allowed for in addition to
the above lists. A rough-and-ready rule to try out will be to
add 50% to the number of test tubes and 25% to the beakers,
flasks, and porcelain ware you buy from the above lists. Of
other things which are breakable, add one extra for each five
that you need.

 3. CHEMICALS FOR THE SIMPLEST LABORATORY
 The list of "Supplies for Ten Students" in your manual is
inadequate in several respects. Some chemicals are used very
frequently, others rarely. The quantities suggested "for a year's
use" are not the proper ones; you do not expect to exhaust com-
pletely your supplies at the end of each year. And, besides,
why should you buy only an ounce or two of magnesium sul-
fate, for example, when the price is merely 10 cents a pound?
In the following lists I suggest the most economical quantities
for purchase.
 Again, first things first! With the supplies in List A, a fair
number of fundamental experiments may be performed:
 With Lists A and B, a considerable number of experiments
with familiar substances may be added;
 With Lists A, B, and C, a really satisfactory number of ex-
periments may be carried out.
 List A. Chemicals for the Fundamental Experiments
 18 lb. acid hydrochloric 10 lb. marble, lumps
 18 lb. acid sulfuric 1 lb. phosphorus, yellow
 2 lb. alum, lumps 2 lb. potassium chlorate
 1 lb. barium chloride 4 oz. silver nitrate
 8 oz. bromine 5 lb. sodium carbonate (washing
 2 lb. calcium fluoride soda)


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