Page:Popular Science Monthly Volume 17.djvu/539

Rh but, in the common mode of pursuing it, the pupil gets but very little real knowledge of the subject. He 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