2. Dissolve 2 teaspoonfuls of cream of tartar in 1/2 cup water in a gla.s.s.

Dissolve 1 teaspoonful of bicarbonate of soda in 1/2 cup water in a gla.s.s.

Taste both of these.

Test both with litmus paper, noting the change of color. There are several vegetable coloring matters that change color in this way, in the presence of an acid or an alkaline substance.

Turn the two solutions together, and test with both blue and pink litmus paper, after the solution has stood for several minutes. What results?

Taste this mixed solution to see if you can detect any difference.

To prove that there is a substance still left, evaporate the water.

3. A pretty form of this experiment is to use, instead of litmus, the water in which red cabbage has previously been boiled and which therefore contains some of the coloring matter of the cabbage. The changes in color are very striking, and prove conclusively that neither the cream of tartar nor the soda remains such.

_B. Oven experiments._

If one oven in the school kitchen can be equipped with a chemical thermometer inserted in the oven, the following experiments are helpful.

1. Let each pupil test the oven by feeling, when it has reached 380 F., 400 F., 425 F., 450 F., 475 F.-500 F.

2. Place pieces of white paper, one for each pupil, in the oven for five minutes at the various temperatures. These may be pasted in the notebook for future reference.

=1. Popovers, puffovers, or mahogany cakes.=

_Ingredients for 12._

Flour 1 pint Milk 1 pint Eggs 3 Salt 1/2 teaspoonful

Some rules give two eggs only.

_For baking_, heavy earthen cups, hot and greased.

_Method of mixing_ is No. 1.

_Special points._--The liquid must be poured _very_ slowly into the flour to prevent lumping. A large Dover egg beater is convenient for beating out lumps, if any occur.

The leavening of the popover is effected by steam, and it is not necessary therefore to spend time and strength in the long beating sometimes recommended. This has been conclusively proved by experiment. Neither is it necessary to put the batter into the oven immediately, as sometimes directed. It may stand all day or even over night.

Pour the batter in the hot cups, having each cup two thirds full.

The baking of the popovers is unique, in that they should be put into an intensely hot oven for the first stage of the baking-- as hot as 475 F., or even more--then the oven must be cooled. This first stage crusts the top; then the expansive force of the steam pushes up the top; and the m.u.f.fin "pops" or "puffs" over. The more moderate heat cooks the sides and the bottom, and makes an agreeable crust. The perfect puffover is hollow. Three quarters of an hour is the average time of baking. If at the end of that time the oven door is set ajar, and the popovers allowed to remain longer, they are improved, coming from the oven stiff and crisp with a rich brown color, rather than soft and underdone. In an old family cookbook, one recipe, sixty years old, calls popovers "Mahogany Cakes."

They may be eaten as a m.u.f.fin, or served with a pudding sauce as a dessert.

=2. Plain m.u.f.fins.=

_Ingredients for 12._

Flour 1 pint Baking powder 3 teaspoonfuls Salt 1/2 teaspoonful Eggs 2 or 1 Milk 1-1/4 cup b.u.t.ter, _or_ b.u.t.ter subst.i.tute 1 tablespoonful Sugar, if desired 1 tablespoonful

_For baking_, greased m.u.f.fin pan. Bake about half an hour.

_Method of mixing_ is No. 1.

This recipe may be varied in many ways.

(_a_) Use 1/2 cup cooked cereal in place of an equal quant.i.ty of flour. Will you change the amount of wetting?

(_b_) One cup fine white corn meal, or 1/2 cup yellow meal in place of equal quant.i.ties of flour. Corn meal absorbs more water than white flour.

What change in the wetting?

The oven should be the temperature for bread, and the baking at least 3/4 of an hour.

(_c_) One cup Graham or rye meal in place of an equal quant.i.ty of flour.

=3. Baking-powder biscuit.=

_Ingredients._

Flour 1 pint Baking powder 3 teaspoonfuls Salt 1/2 teaspoonful b.u.t.ter, _or_ b.u.t.ter subst.i.tute 1 or 2 tablespoonfuls Milk 1 scant cup

_For shaping_, molding board, rolling pin, and biscuit cutter.

_For baking_, an iron sheet or pan sprinkled with flour. Oven about 425 F., a ten-second test, or golden brown paper. Bake twenty minutes to half an hour.

_Method of mixing_ is No. 2.

_To shape._ Dust the board with flour, turn out the dough, dredge with flour, pat into a firm ma.s.s, and then pat or lightly roll out to 1/2 inch thickness. Cut out with a cutter dipped in flour. (A small gla.s.s or the top of a round tin can may be used.)

_Variations._--Add 1 egg. This makes a delicious biscuit. Sprinkle the top with granulated sugar, and spice. Dried currants washed, and dredged with flour, may be laid on the top.

Increase the b.u.t.ter to two or three tablespoonfuls, and decrease the wetting and the mixture becomes _shortcake_. This is the mixture to use for the true strawberry shortcake. Many other fruits may be used, both uncooked and cooked.

=4. Sour milk griddlecakes.=

_Ingredients._

Flour 2-1/2 cups Salt 1/2 teaspoonful Melted b.u.t.ter 2 tablespoonfuls Sour milk 2 cups Soda 1-1/4 teaspoonfuls Egg 1

_Method._--Mix dry ingredients. Add sour milk, egg well beaten, and melted b.u.t.ter in order given. Beat thoroughly. Drop by spoonfuls on a greased griddle and let cook until the edges are cooked and the cake full of bubbles. Turn with a cake turner or spatula knife and cook on the other side. Serve with b.u.t.ter and sirup or sc.r.a.ped maple sugar.

=5. Sweet milk griddlecakes.=

_Ingredients._

Flour 3 cups Baking powder 4 teaspoonfuls Salt 1 teaspoonful Sugar 1/4 cup Milk 2 cups Egg 1 Melted b.u.t.ter 2 tablespoonfuls