Popular Science Monthly/Volume 17/August 1880/Chemical Exercises for Ordinary Schools
|CHEMICAL EXERCISES FOR ORDINARY SCHOOLS.|
PROFESSOR RAINS'S little book for beginners in analytical chemistry has been already noticed and commended in these pages, but its method is so excellent that it needs to be more fully explained.
Chemistry is now a regular study in many if not in most schools; but, in the common mode of pursuing it, the pupil gets but very little real knowledge of the subject. lie reads about it; learns lessons upon it; works out chemical calculations for examination; and, perhaps, sees some lecture-room experiments. He acquires some general ideas, but he gets very little actual, thorough, practical knowledge of the properties of chemical substances, and no such familiarity with chemical operations as is necessary in order to turn this branch of study to valuable account. Professor Rains saw that all this was unsatisfactory; and that, to make his knowledge good for anything, the pupil must experiment, must test the properties of substances, and himself find out how they behave and react toward each other. In short, if he has any honest, intelligent, educational purpose in view, he can only gain it by practice and direct experience with chemical agents and materials.
But there is a difficulty at the outset met everywhere, and which is generally fatal to all thorough chemical study in ordinary schools. Practical chemistry is dirty work. It makes slops and fumes, and damages furniture and clothing, and, as has been graphically said, it is altogether an unsavory affair of "messes and stenches." With such a reputation it is, of course, held to be unsuited to the schoolroom, which indulges no further in dirt than is compelled by the use of chalk and the blackboard. In this respect school habits are established. Practical chemistry must, therefore, have its separate place, its laboratory, which is a shop and not a schoolroom. Chemistry involving "exercises," or manipulations in object-study, is therefore expelled from the schoolroom to a place fitted up for it, so that chemistry in ordinary schools is a matter of book-learning and second-hand information, such as is now correctly characterized as "sham knowledge."
Professor Rains has addressed himself to this difficulty, which he aims to overcome so effectually that practical chemistry may be pursued almost anywhere with but very little inconvenience. He saw that this is the first and indispensable step to success in making chemistry a real branch of common education; and he accordingly set himself to contrive a little compact, portable laboratory, such as can be readily used anywhere, and would at the same time prove adequate for the uses of the student. And he has well succeeded in his object. The accompanying woodcut represents his device. It consists of a revolving test-stand, twenty or twenty-four inches in diameter, made of galvanized iron or strong tin-plate, so as to hold a large number of test bottles, containing the reagents for analysis. These bottles stand side by side, and are kept in position by an outside and inside rim, soldered to the circular plate. There is a hole in the center of this plate, and a tube, fifteen inches long, has its lower end soldered above it, the upper end being closed. An iron rod, screwed into a stand or base, and conical at the top, passes up through the tube and supports the whole upon its point. To stiffen the arrangement, three bent strips of tin are fastened to the top of the tube and to the inner rim, as shown in the woodcut, where the middle strip conceals the central tube. There is room inside the circle of test-bottles to place the other bits of apparatus when not in use. The whole construction occupies but a small space, and can be conveniently set aside when not required,
or left in any corner or closet, and covered by a piece of cloth, to protect it from dust. For practice it is placed on any common table, and two pupils can readily use it at the same time from opposite sides. It turns so easily that any test-bottle wanted can be taken and directly returned to its numbered place, so that it is kept constantly in order for continued exercises.
It must not be supposed that this is merely a nice plaything to enable boys and girls to make amusing chemical experiments. Professor Rains had a very serious purpose in preparing it; and it is designed for systematic chemical work. It has been adapted to take pupils through a course of qualitative chemical analysis. Besides the necessary apparatus, there is a sufficient equipment of test-substances for going through a full course of analytical exercises. At the very outset the pupil begins to think, and has to make his own way. He learns the properties of chemical bodies by trial and observation; and his progress consists in solving a succession of problems by finding out and identifying chemical elements and compounds. Some seventy or more simple salts soluble in water are the substances chosen for examination, and these are first tested to find the base or metallic component of the salt, and then to find the acid or electro-negative element. It is a work of investigation from the start, and what the pupil learns he knows. There are no recitations, the evidence of proficiency being what the pupil can do. The course is one of self-instruction, and its value depends upon the principle that one difficulty overcome by the pupil himself is of more educational benefit than a score of difficulties over which he is helped by others. Professor Rains's little accompanying manual begins by explaining the use of the necessary apparatus, and then the inquirer is directed how to enter upon his regular work; but, the problems being presented in order, he is left to solve them himself, which is the only way in which he can become a chemist.
Nothing so neat, compact, and convenient as this mechanical arrangement has ever before been furnished for beginners in analytical chemistry. The method has grown out of Professor Rains's experience as a chemical teacher; and only by a long course of assiduous trials with students and classes could he have succeeded in putting into such small compass, and such a portable and convenient form, the facilities of manipulation by which a practical foundation in the knowledge of the science can be laid. In his annual course of lectures upon "Physics" and "Chemistry" at the Medical College of Augusta, Georgia, Professor Rains has among his students the senior class of Richmond Academy, an institution in which for several years he has been the teacher of Natural Science. As a result, he became convinced that a much larger amount of chemical study than is commonly supposed, and that, too, by direct chemical work, might be given to the senior classes of ordinary schools where there is no laboratory, and no specially qualified chemical teachers. He was so sure of this, and so impressed with the value of practical work in chemical analysis—the most interesting of all chemical practice—that for several years he has given the senior academy class a certain amount of chemical testing to do by themselves, furnishing them only with simple apparatus and clear directions. In this way the self-education of the pupils has gone forward with the happiest results. Satisfied that the same advantages may be secured by others, if they have only the requisite means of practice furnished to hand, he has constructed the little laboratory that will now be furnished to anybody by the instrument-maker.
As to what has been actually attained with classes by this method of study, Professor Rains thus remarks in his preface: "At the recent closing exercises of the examination of the pupils of the academy, which took place at the Opera-House before a large audience, the following were the results from the chemical class of fourteen students: Samples were taken at random from the bottles of different commercial salts (single bases and acids) by one of the trustees and given to each student. Of the fifty analyses made in a little over one hour, not a single failure was made. The class had studied theoretical chemistry for seven months three times a week, one hours recitation each; after which they had table-practice for eight weeks, or twenty-four school-hours; to which as many more were voluntarily added by the students after school, making forty-eight hours in all of analytical work."
This brief statement is full of important suggestions. The preliminary study of theoretical chemistry for seven months, probably in the ordinary way of lesson-learning, was, no doubt, somewhat helpful; and it would be well for all pupils, in entering upon a course of exercises in analysis, to be possessed of some elementary chemical ideas. But the practical experience of actual investigation is so much a thing by itself, that those who have read up do not really have the great advantage over beginners that might be supposed. The pupil who goes to work fresh will very soon get the elementary conceptions needed, and he will then read chemistry with redoubled interest, and to better purpose.
But what is significant in this case is that, when the pupils came to practical work, they voluntarily doubled their tasks, and this, too, notwithstanding the "hardness" of exercises that had to be mastered un-helped. The mode of study was attractive because there is no pleasure like the sense of power that comes from conquest. There is, moreover, a fine satisfaction in that free play of the faculties which self-instruction implies; and Professor Rains says, "The students are allowed entire freedom while at work." The superiority of this mode of study can no longer be questioned; and Professor Rains has done a very important service to education in thus facilitating the thorough and at the same time pleasurable pursuit of one of its most useful branches.