rous nitrate and mercuric nitrate from mercury; boric acid from borax; zinc sulphate as a by-product of the preparation of hydrogen; sodium thiosulphate from sodium sulphate; mercuric sulphocyanide from mercuric nitrate; zinc oxide from zinc sulphate; and potassium nitrate from wood ashes.

It has been demonstrated that the pupils are greatly interested in such experiments and spend many hours willingly in completing these preparations.

The committee does not desire to outline other topics in detail, since too much elaboration might tend to retard rather than stimulate the proper reorganization of the chemistry course. The following list is added to show a great variety of interesting topics which may be drawn upon for illustrative and informational purposes and for developing the fundamental generalizations of chemistry. Local conditions, the interest and needs of the particular class, and the time available should determine the choice of such topics and their proper organization into the larger units of study. The following list could be greatly extended:

Glass.-Crown, flint, lead, special glasses, coloring of glass.

Clay products.-Brick, pottery, chinaware, porcelain.

Artificial stone. Lime, plaster, mortar, hydraulic cement, concrete stucco, plaster of paris.

Fertilizers. Problems of soil fertility, elements needed by growing plant and function of each. Photosynthesis and carbon dioxide cycle. Nitrogen cycle and function of nitrogen fertilizers. Use of limestone and phosphate rock.

Coal. Composition and fuel values of different varieties. Distillation of coal tar, light oil, middle oil, heavy oil, tar, pitch. Relation to dyes and explosives. Petroleum. Fractional distillation into burning oils, solvent oils, lubricants, paraffins. Problem of gasoline supply and possible exhaustion of petroleum. Wood.-Distillation of wood to produce methyl alcohol, acetone, acetic acid,

charcoal.

Explosives.-Black powder, nitroglycerine, dynamite, guncotton, trinitrotoluene. Relation to nitrogen fixation by arc, Haber, and cyanide processes. Paint, varnish, etc.-Oil paints and driers, varnish, shellac, copal. Linseed oil, oilcloth, linoleum.

Pigments. White lead, red lead, iron oxide, lead chromate, etc.

Textile fibers.-Natural and artificial silk. Wool: Scouring, bleaching, felting, etc. Cotton: Bleaching, mercerizing, etc.

Dyeing. Direct and mordant dyes.

Cleansing agents.-By acid: Oxalic, hydrochloric. By alkalies: Caustic soda, soap emulsification. By special solvents: Carbon tetrachlorid, benzene. Composition of trade-marked cleaning fluids.

Photography.-Blue prints, plates, films, prints, toning, etc.

Food constituents.-Starch preparations from corn; cooking to dextrin and to paste, hydrolysis to glucose.

Sugars. Preparation and refining of beet and cane varieties; conversion to caramel; inversion.

Fats.-Olive oil, cottonseed oil, butter, oleomargarine, hardening oils by hydrogenation.

Proteins.-Albumins, casein, gluten, peptones, gelatine, vitamines.

Beverages.-Charged waters, soda, mineral, infusions, tea, coffee, chocolate. Fruit juices (artificial flavors), fermentation.

Poisons and common antidotes.-Common inorganic drugs.

Leavening agents.-Yeast, soda, baking powders.

Matches.-Ordinary and safety types.

Adhesives.-Gums, paste, dextrin, glue, casein, water glass (sodium silicate). Inks. Various types.

Refuse disposal.-Sewerage, garbage; fermentation and putrefaction; civic problems; disinfectants and deodorizing agents.

Preserving. Sterilizing, pasteurizing, dessicating, pickling by salt and sugar; chemical preservatives and tests for them.

Metals. Extraction processes; oxide ore, iron, sulfid ore, lead; electrolysis, sodium and aluminum; extraction of other metals may be studied by comparison with these.

Metals used for basic purposes, iron, copper, aluminum, lead; for ornament, gold, silver, nickel; for alloys, bronze, brass, solder, type metal, antifriction or bearing metals, fusible metal.

F. Differentiated chemistry courses for certain curriculums.—The content of the regular course in chemistry has been indicated in the two sections just preceding. It is designed to meet the needs of young people and to enable such as need it to count the work done. for college entrance. It remains to show how modified chemistry courses may be offered to meet the requirements of special groups of pupils by including topics and problems bearing more directly on the work these pupils will enter or in which they are already engaged. These differentiated courses are chiefly of two types, those which aim to better prepare girls for home making and home management and those offered in technical curriculums to suit the needs of students primarily interested in industry. These two types are briefly considered.

1. Courses in household or domestic chemistry.-There are two methods which are followed in teaching household or domestic chemistry. Girls may be taught the regular chemistry the first half of the year and the second half they may be given instruction in topics relating directly to the home, or a year's course in household chemistry may be given. Each school should choose the method best adapted to its organization. If a year's course of household chemistry is given, the first half should emphasize the study of chemical change, combustion, water, air, acids, bases, salts, and chemical formulas. In the second half the following topics should be emphasized: Carbon compounds in their relation to fuels, cooking, and foods; metals used in the home, as iron, copper, aluminum, and silver; textiles and cleaning agents; dyeing and removal of stains; fertilizers and insecticides; disinfectants and antiseptics; poisons and their antidotes; paints and varnishes.

2. Courses in technical curriculum.-In many technical curriculums there is a demand for a two or three years' course in chemistry. In such cases the elementary course is given in the tenth or eleventh year, followed by qualitative analysis and organic chemistry. Some teachers may prefer to give in the second year a half year of advanced general chemistry and a half year of qualitative analysis. In addition to these, special courses for certain types of students should be offered if there are facilities and if there is sufficient demand for the work. To illustrate, a few courses which have been successfully tried in the continuation and evening classes of a large technical high school are described:

(a) Chemistry for nurses: Girls who study nursing find it of great advantage to know something of the fundamental principles of chemistry. Many of the girls have not completed a high school course and have not studied chemistry. For such girls a special course consisting of laboratory work and discussion two afternoons a week for 13 weeks is given. This course covers elementary chemistry through carbon compounds, and emphasis is placed on the study of substances used as drugs and in the home.

(b) Chemistry for electroplaters: A large percentage of men actually engaged in the electroplating of metals have only a common school education, and their work is done mechanically. Without a knowledge of the fundamental principles of chemistry and electricity the men find much difficulty in solving their problems. To remedy this condition the National Society of Electroplaters has been organized. At least one technical high school has been cooperating with this organization the past two years. A special class for electroplaters has been conducted in the evening school. The men study elementary chemistry, electricity, and volumetric analysis and discuss their problems with the instructor. The students are very enthusiastic over the course and they have become more intelligent and skilled workers.

(c) Chemistry for pharmacy: Some high schools offer a course in pharmacy. For this purpose a three-year course in chemistry is desirable. The first year the pupils study elementary chemistry, which differs from the regular course by emphasis on technique, preparation of tinctures and ointments, the study of drug manufacturing, and chemical arithmetic. Qualitative analysis is studied the second year, quantitative analysis and organic chemistry the third year.

(d) Special courses for workmen and foremen in chemical industries: Some manufacturers permit their employees to study in technical high schools for one afternoon a week in order to make them more intelligent workers. The chemistry course in these cases is

adapted to the needs of the individuals. Where facilities permit there is opportunity for great service to the men and the community. A course in simple, inorganic preparations, such as ammonium, sodium. and potassium compounds, is valuable to teach in connection with or following the elementary course.

IV. PHYSICS.

A. Why reorganization is necessary.-The need for a thorough reorganization of physics is evidenced by the following considerations:

(1) The content and methods of presentation in vogue for the past 20 years have failed to make a vital appeal to most pupils. With the large majority the subject has aroused little enthusiasm.

(2) The content has been too largely that handed down by tradition through the textbooks, which were largely based on the logical organization of subject matter, neglecting the interests of pupils and. the laws of learning. Some of the material is obsolescent or wholly obsolete, because it treats of applications of physical theory to problems now of little or no value, and much of it has no connection with the present-day activities in the industries, in municipal enterprises, on the farms, and in the homes.

(3) The teaching of the past has too frequently assumed that a principle may be readily grasped if only it be once stated in clear language and illustrated by a few examples, and that it may then be generally applied with comprehension and completeness. It is now recognized that principles may be best arrived at and comprehended through solving problems. From such experiences the teacher should guide and stimulate the pupils to recognize that they must arrive at the generalizations by their own mental processes. In order to have the power to apply these principles, pupils must have practice in applying them. Such applications not only make the principles usable, but also clarify the understanding of the principles themselves and stimulate the interests of the pupils.

(4) With a few exceptions the class work and the laboratory work have not been intimately connected. A formal list of laboratory experiments has been made the main feature of the course, and formal textbook recitations not closely related to the laboratory experiments have completed the program. This failure to coordinate laboratory work with recitations and class discussions is pedagogically unsound and is wasteful of effort.

(5) The traditional courses do not contribute as physics can and should to help pupils to understand the higher type of vocations in which physics is fundamental, such as mechanical and electrical professions and trades. This failure prevents physics from making the

contribution which it should render in vocational and educational guidance, and also in giving a liberal understanding of the world's work.

(6) Many schools have already made changes which have resulted in marked improvements in interest and in outcome.

B. Local surveys needed.-In order that the teaching of physics may be adapted to actual needs, the teachers in each school should make a careful survey to determine what physical facts and phenomena are especially significant in local occupations and contacts, since pupils of high-school age naturally look forward to taking active part in adult vocational, social, and civic life. These facts and phenomena, collected in the survey of the whole subject, should be analyzed and classified with reference to the principles of physics that underlie them, with reference to the wideness and frequency of their uses, and with reference to the interest and teaching utility of the projects arising therefrom.

C. Aims.-Physics, in common with the other science courses in secondary education, should be directed so far as possible to the realization of the seven main objectives of education defined by the Commission on the Reorganization of Secondary Education to be: Health, command of fundamental processes, worthy home membership, vocation, citizenship, worthy use of leisure, and ethical character. To realize these objectives, education must develop certain specific interests, ideals, habits, and powers, as well as an essential body of knowledge.

Among the habits and abilities which should be developed in all science teaching and which should be emphasized in physics instruction, the following may be enumerated:

(1) Observing accurately significant facts and phenomena, and at the same time neglecting distractions and details that have no direct relation to the problem in hand.

(2) Developing a methodical plan of attack before beginning an experiment or set of observations.

(3) Using eyes, ears, and hands before consulting books, when knowledge of phenomena is sought.

(4) Maintaining system, order, and neatness in the arrangement of apparatus and appliances for the observational and experimental work.

(5) Using care and intelligence in the manipulation of tools and apparatus, endeavoring to acquire a good technique.

(6) Making measurements where quantitative knowledge is required, always carefully, intelligently, and as accurately as is demanded by the nature of the knowledge sought, but not more so.