PART III. SCIENCE. (continued 2)

Broad principles recommended.Briefly then, I would recommend that the following broad principles should be adopted with pre-examination classes:—

(1) Elementary physical training to be made continuous with kindergarten teaching.(1) The course of elementary physical science which is then necessary foundation for a sound knowledge of chemistry should be made continuous with the object-lessons of the kindergarten, and should form a progressive course extending over three or four years, passing imperceptibly into elementary chemistry.

(2) The elementary course to be entirely “practical”.(2) This course should be of an entirely practical character and should be carried out in a room very simply equipped for the purpose. No text-books should be allowed and no notes dictated by the teacher, but each pupil should subsequently to the lesson write out in her own words an account of her own experiments, of which she is encouraged to take notes at the time of doing them.

Advantage of occasional lectures.Although all formal lessons on the simple subjects of investigation serve only to prejudice the minds of the children, lectures given at rare intervals on kindred subjects and profusely illustrated serve as a healthy stimulus to the youthful appetite for experiment and research.

(3) Choice of experiments.(3) The practical course should be so chosen that each experiment illustrates in the simplest possible manner some fundamental principle or “law” of nature. It is precisely here that a teacher has the opportunity of educating the logical faculties of the pupils, each of whom is required to solve independently the simple problem set before her at the lesson and is thus placed in a position to deduce for herself from her own experiment the principle involved. The children are in fact placed, as Dr. Armstrong recommends, “in the attitude of discoverers,” and it is astonishing how soon they learn to become independent in their methods of attacking new problems if their minds are not prejudiced by preconceived ideas of the results to be expected.

(4) Size of classes.(4) As regards the size of the classes and the time to be allowed for each, the Committee of the British Association recommends that “a teacher should not be required to give practical instruction to more than from fifteen to twenty pupils at one time, although the classes at lectures and demonstrations might be somewhat larger”. For the course indicated below one hour a week may be made sufficient at first, but later on an hour and a half should be allowed for each practical class.

(5) Accommodation.(5) As to accommodation, it is quite possible, at any rate at first, to use an ordinary class-room, but as environment no doubt does exercise a certain influence the use of a special room very simply equipped with long tables supplied with water and gas is strongly advised.[26]

The above recommendations are meant to apply to all classes up to the time when the needs of public examinations demand a special course; this must necessarily be given by means of set lectures, as it could not otherwise be covered in the limited time which is generally allotted to the subject; they are more or less in accordance with those drawn up by Dr. Armstrong for the Committee of the British Association of which mention has been made, and which were embodied in the Syllabus of Physics and Chemistry issued by the Incorporated Association of Head Masters in 1895; since this date they have been successfully carried out in various boys’ schools. Owing to the enterprise of Miss L. E. Walter a similar course was introduced at an even earlier date into the Central Foundation School for Girls, where it is now in operation. Appended is a very brief outline of the course there pursued, together with a typical set of lessons in chemistry.

Outline of a science course now in operation.On leaving the kindergarten the science teaching is confined to what is really practical arithmetic and geometry, elementary measurements being performed by the most ordinary methods. The children are thus accustomed to the use of simple apparatus such as pipettes, burettes, etc., also to the use of the balance, the simple numerical calculations involved in weighing and measuring being performed in both the English and decimal systems, which are thus made quite familiar.

The following example, quoted from Miss Walter’s paper,[27] gives a clear idea of the sort of introductory teaching needed. This lesson, although of the simplest character, had for its object to show the necessity for, and to choose a unit of length. This is how it was done: “I gave each girl but one a piece of string, all the pieces being the same length; the one odd girl I kept by me, and we had a ball of string. I asked the children to tell me how long their pieces were so that I could cut a similar piece. Naturally they began by guessing—a yard, half a yard; but as I had no yardstick, I feigned ignorance of what a yard was. Soon one put the string along her slate and expressed the length as a slate and three-quarters. Every one else followed suit.... After each of the sensible measurements which they made ... I did the same to my small comrade as they had done to themselves and cut off a piece of string. Then they all watched with great interest to see if my piece really did come like theirs.... This lesson may not sound very exciting, but during the whole time each of those children was alive, each was thoroughly interested in what she was doing.”

The preliminary course consists in its earlier stages of exercises in the measurement of length, area and volume with the use of the balance; this is followed by experiments on density, and subsequently some work on heat is done, a simple thermometer and barometer being made and graduated by each girl, who is encouraged to use them to record the weather by means of curves showing variations of temperature and pressure. It may have been completed by girls of about fourteen, who will then be quite prepared to begin chemistry, having by that time gained a very good idea of how to apply their arithmetic as well as their knowledge of the fundamental physical principles to the solution of practical problems.

It is important to point out that the system here advocated inverts the usual order of teaching chemistry. This subject is divided into “pure” and “physical,” and it is usual at the present time to begin by teaching “pure” chemistry, that is to say, the preparations and properties of a number of the commoner elements and compounds, this part being considered easier than “physical” chemistry, which however ought logically to precede it, since it treats of the fundamental laws upon which “pure” chemistry depends.

A knowledge of simple physical chemistry is now required for all chemistry examinations, candidates for which are expected to have a working acquaintance with simple physical apparatus, to be familiar with the barometer and thermometer, the effects of heat on solids, liquids and gases, density and specific heat, etc., etc.; they are liable moreover to be asked to solve any simple problems on measurement. Now by giving precedence to “physical” chemistry, all this is done and done thoroughly before examinations are thought of, so that what is generally regarded by pupils at the present time as the most difficult portion of their subject is made by this means its A B C, and the time spent upon actual examination work can be considerably curtailed.

“Pure” chemistry is introduced by the study of the methods of testing all kinds of substances so as to be able to classify them roughly as mineral or vegetable, organic or inorganic, etc. The chemistry course suggested by Dr. Armstrong and adopted by the Incorporated Association of Head Masters is strongly to be recommended, as it is drawn up particularly with a view to imparting “not only information but chiefly a knowledge of method”. It opens with “studies of the effect of heat on things in general; of their behaviour when burnt,” and goes on to the investigation of such familiar things as air and nitrogen, combustion and oxygen, hydrogen and water. Formulæ and equations are rigidly excluded, the aim being to give a broad introduction to the subject; on the other hand quantitative experiments form a much larger part of the curriculum than is usually the case, the previous training in physical methods having prepared the way for teaching chemistry in a more exact manner than is generally possible with beginners.

A girl who has gone through the scientific training outlined in the preceding pages will possess an elementary knowledge of many subjects; she will find little difficulty in mastering the information required for the London Matriculation or any other preliminary examination in physical science, the greater portion of the ground both in physics and chemistry having already been covered during the preliminary course indicated. It is certain that students who have undergone such a systematic education without hurry and without pressure, and with opportunities for reasoning out each step for themselves, will be in a condition to derive the maximum of benefit from subsequent instruction not only in chemistry but in all other branches of knowledge.

Typical Lessons in Chemistry.

At the beginning of the lesson the problem to be solved is announced by the teacher, who invites suggestions as to how it should be attacked. A scheme of work is thus prepared which is carried into practice by the pupils; every detail of manipulation is performed by the girls themselves, who select their own apparatus, bend their own tubing, etc., referring only occasionally to the teacher for help. The scheme is elaborated as the investigation proceeds so as to form a piece of consecutive reasoning which may extend over a series of lessons.

Problem. To discover the constitution of chalk.

Typical lesson.Being familiar with simple methods of testing unknown substances, heat and the action of acid are at once suggested by the pupils as a means of investigation, and a preliminary examination is made showing that heat does alter chalk in some way, whereas the addition of acid causes the liberation of a gas. The next step is to find out whether the chalk loses or gains anything by being heated; also to determine the nature of the gas given off under the influence of acid.

Suggestions are again received from the girls, who are led to decide that the first part of the question may be answered by submitting a weighed quantity of chalk to a moderately high temperature, weighing at intervals until the weight, if it changes at all, again becomes constant.

They proceed therefore to weigh their empty crucibles with the usual precautions and then to reweigh them after having put in some dry chalk. The numbers obtained are carefully entered in the laboratory note-book with which each girl is provided. The crucibles are then placed in a “muffle” furnace, which the pupils are taught to manage for themselves, and are only withdrawn at the end of the lesson and placed in desiccators to be reweighed at the beginning of the next lesson, when they will be again submitted to the same treatment until the weight is constant.

While the crucibles are being heated preparations are made for finding out the action of acid on chalk; the pupils are led to suggest a simple form of apparatus for measuring the volume and weight of the gas given off, and hence for determining its density. By the time this is done the hour and a half allowed for the lesson will probably have expired. At the next lesson, after a preliminary questioning as to what each pupil has done and is going to do, the apparatus decided upon at the previous lesson is carefully prepared; subsequently the actual experiments to determine the quantity of gas given off are performed and its density determined, and finally it is shown that the gas given off from chalk under the action of heat is identical with that released by acid, chalk being composed of this gas and the residue left after heating it in a muffle furnace until the weight is constant.

It will be seen that this work involves a considerable amount of weighing and calculation, but this is rendered easy by the previous grounding in elementary physics, and a series of experiments such as that described may be carried out intelligently by any properly trained class of girls.