THE BRITISH AND FOREIGN MEDICO-CHIRURGICAL REVIEW OR QUARTERLY JOURNAL OF PRACTICAL MEDICINE AND SURGERY. VOL. XLVI. JULY-OCTOBER, 1870. LONDON: JOHN CHURCHILL AND SONS, NEW BURLINGTON STREET. MDCCCLXX. THE BRITISH AND FOREIGN MEDICO-CHIRURGICAL REVIEW. JULY, 1870. Analytical and Critical Reviews. I.-Laboratory Teaching.1 THE importance of chemistry as an educational instrument, and as a valuable branch of knowledge, is becoming gradually recognised. Of course, for thirty years to come, we must not expect our legislators to do much towards helping forward the general diffusion of natural science. The present race of politicians, and, in fact, 999 in 1000 of our upper classes, had no opportunity during their school or college life of learning anything concerning the materials and forces of nature. Physicians, chemists, and natural philosophers, who know what powerful aid science can render to the advance of our country, must do more than they have yet done to impress their convictions upon influential and intelligent, though in this matter ignorant, persons. First of all, however, our methods of instruction must become more definite, and more worthy of the great branches of knowledge with which they are concerned. We take the present opportunity to offer some suggestions as to the way which shall be at once the soundest and the most effective of teaching practical chemistry. Whatever may be the ultimate path in life of the schoolboy or the student, their first steps in chemistry should be identical. 11. Qualitative Chemical Analysis. By Dr. C. R. FRESENIUS. 7th edition. Edited by ARTHUR VACHER. Pp. viii, 264. 2. An Introduction to Practical Chemistry, including Analysis. By JOHN E. BOWMAN. Edited by C. L. BLOXAM. 5th edition. Pp. xx, 316. 3. A Course of Practical Chemistry, arranged for the Use of Medical Students. By W. ODLING, F.R.S. 4th edition. Pp. xii, 235. 4. Chemistry, General, Medical, and Pharmaceutical. By JOHN ATTFIELD. Pp. viii, 624. 5. Laboratory Teaching; or, Progressive Exercises in Practical Chemistry. By C. L. BLOXAM. Pp. xx, 227. 6. Exercises in Practical Chemistry. By A. G. V. HARCOURT, F.R.S., and H. G. MADAN, M.A. Series I. Qualitative Exercises. Pp. xv, 355. 91-XLVI. 1 Chemistry is often made not only uninteresting but unintelligible if the lecturer or teacher plunges, as he too often does, into the arcana of the science; the laws, for instance, of volume and of atomic weights. Let him commence first of all by mentioning and showing some material, some phenomenon, some experiment, with which even the most unobservant boy must be familiar. In the hands of a judicious teacher, a splint of wood, a marble, a lucifer match, a drop of ink, a pinch of gunpowder, will secure the attention of his auditors. The interior and hidden meanings and powers of well-known objects will be revealed, and the knowledge, though pleasantly gained, is not usually easily forgotten. But the lecturer has only accomplished half his work until he has made his pupils repeat, as soon after his lecture as possible, all the feasible and important experiments he has shown and explained. Thus a series of laboratory lessons is devised in which familiar things-the air that enters and that leaves the lungs, the water we drink, the soil of our fields, our metallic coinage, quicksilver, sulphur, and a hundred other common bodies-are made the subject of testing and experiment. Advantage should, of course, be taken, here and there, of any very suitable and striking result, to expound, by its means, the chemical laws which it may happen particularly to illustrate. When sulphur is the subject of experiment, the three molecular states of matter may be introduced; when zinc foil is burnt in a candle, the nature of oxidation and oxides may be unfolded; when water is decomposed, and its constituents afterwards reunited, combination by volume and the evolution of heat may be described. We urge, then, not only the use of common and familiar materials, and the greatest simplicity of arrangement, but the gradual development of the laws of the science. Too often an utterly different and, we presume to say, a totally wrong method of teaching chemistry is adopted; long and tedious tables of elements and atomic weights, with the laws of combination and other details, dry at first but interesting afterwards, are given out to be learnt, and the boys conclude that chemistry is a dull matter after all-only another sort of arithmetic; the brilliant lights and gay colours which they have seen associated with it being, as it were, the jam that covered the grey powder! And the common way of teaching chemistry goes wrong in another direction. Chemistry should be taught in the same way as, during the last 100 years, it has been itself developed or learnt. The familiar things which chemistry explains should be introduced, not so much as illustrations of chemical facts and laws, but as being the very starting-points from which those facts and laws have been evolved. Tannic acid, for example, should not introduce leather, but leather tan nic acid; a looking-glass and a cake of vermilion will serve a double purpose if used as points of departure for a description of mercury, rather than as mere illustrations of the application of this metal to common uses. Thus the objects of everyday life, even our food, our clothes, and the contents of our rooms and our pockets, will remind us continually of some of the chief facts of an exact science, and make that science interesting. It has been said by a recent writer, who ought to have, but evidently has not, much real acquaintance with our present subject, that the last thing to be thought of is to make scientific teaching interesting. For two reasons chemistry ought to be made interesting to boys, for thus only will it be possible to get the attention of a fair proportion of any audience, and at the same time to secure and concentrate on the subject all the available mental powers of each individual. Another characteristic of chemical teaching, if it is to be not only interesting, but sound and effective, may now be noticed. It is a characteristic which can be more largely developed at college than at school. It is often necessary, while teaching pure science, to give it a particular bias. One student may be devoting himself to agriculture, another to medicine, another to the fine arts; to each the central laws and facts of chemistry must be taught, but, as opportunity offers, these ought to be introduced and illustrated by examples pertaining to the several arts of agriculture, medicine, or painting. An agricultural student would have, for instance, the laws of diffusion illustrated to him by the processes which go on in the soil and in the plant; the medical student, on the other hand, would study the same laws as they work in the liquids and gases concerned in the functions of the human body. The agricultural student would devote particular attention to those compounds of nitrogen which are used as manure, while the medical student would make the acquaintance of those which are of importance in the treatment of disease. Both students follow the fortunes of nitrogen till it appears as ammonia, then the former combines it with sulphuric acid, the latter with citric; both will study analysis, one to detect and estimate phosphoric acid, the other arsenic. We lay particular stress upon this apparently simple mode of giving a special direction to chemical teaching, because we think that applied and pure science, if thus combined together or taught simultaneously, give each other mutual support. At the same time, it will be evident that medical students, for example, would be able to devote much more time to specially appropriate chemical studies, during their short summer laboratory course, if they had been previously well grounded, when at school, in the elements of the science, and had likewise had it presented |