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 muffin “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 muffin, or served with a pudding sauce as a dessert. =2. Plain muffins.= _Ingredients for 12._