Popular Science Monthly/Volume 24/April 1884/Methods of Instruction in Mineralogy
By M. E. WADSWORTH, Ph. D.,
OF THE MUSEUM OF COMPARATIVE ZOOLOGY, CAMBRIDGE, MASS.
IN the present discussions concerning the relative merits of classical and scientific studies as factors in education, one point seems to be often lost sight of: the difference between instruction given for the purpose of disciplining the mind and that given for the purpose of imparting information. The former appears to be the chief function of our public schools, academies, seminaries, and colleges; the latter the principal object of technological and professional schools and graduate or university courses proper.
It would seem, then, that it is necessary for any one, seeking to replace any disciplinary study by something else, to show that the proposed new study will afford an equivalent amount in kind. In other words, if the scientist can not show that the studies he proposes to introduce into our colleges and high-schools possess, beyond the information given, a power of disciplining the mind, in certain valuable directions, equal to any other studies, his case had better be abandoned. Realizing this, it is proposed to show how instruction in mineralogy can be and has been given in such a way as to cultivate and develop faculties of the greatest value and use to any man, what-ever may be his walk in life. Of necessity, personal experience must be referred to in this case, which is the excuse for the seeming egotism of this article.
It is intended, first, to show how this was accomplished in the elementary course in mineralogy in Harvard College, as given several years ago. This course extended throughout the college year, requiring of the students attendance upon three lectures a week, or their equivalents, and, in addition, at least six hours of laboratory work. Since it (like nearly all the courses in Harvard) was an elective, it was taken only by a limited number of students.
At the time of my acquaintance with it, as a pupil, the first two and a half months were devoted to crystallography, while determinative mineralogy occupied the rest of the year. The crystallography was taught by means of crystal models, with illustrations taken from natural crystals, and embraced certain of the mathematical principles; but the course was largely devoted to the drawing of figures of crystals. Nearly all of this instruction was of a kind that caused the pupil to do his work in a mechanical manner, following "thumb-rules" given by the instructor. The student evidently was not expected to understand the reasons for his work—the great object seemed to be to mechanically produce the most beautiful and perfect drawings; and on this part of the course not proposed to dwell.
The mineralogical instruction was given in the following manner: First, there had been chosen a set of the most important mineral species, amounting to over two hundred in all, with which it was thought best that the student should be familiar. A sufficient number of typical specimens of each species and its important varieties had been labeled and permanently arranged, according to Dana's "System of Mineralogy," in a set of drawers accessible to the student. The instructor, with the specimens before him and the students around him, proceeded to point out the essential characteristics of these minerals, calling attention mainly to those features which would distinguish each mineral from all others in the chosen set. It was not proposed to burden the pupil with long descriptions of each mineral, but rather to require him to know and understand that which separated each one from its fellows, and caused it to stand out distinct from them. To this end every means of determination that seemed essential was put in requisition, except quantitative analysis. If the crystalline form was sufficient, the student was not expected to go further. If the physical properties sufficed, that was all that was necessary; if not, then resort must be had to the blow-pipe, and even to the wet tests. The student was taught to do that which the practical mineralogist does—to determine his minerals by the shortest method consistent with accuracy—the method to vary according to the specimen. The pupil was taught to observe the color, streak, hardness, etc., to weigh the evidence in each case, and to decide according to the weight of the evidence. No guess-work was permitted, but some decisive test was required which should prove that the specimen belonged to the species to which it had been assigned. After a certain group had been passed over by the instructor—as, for instance, the picked species of the native elements, sulphides, etc., and sulpharsenites, etc., of Dana's system—each student was assigned a drawer containing specimens of these minerals, unlabeled and mixed together. These specimens were selected so as to be fair representatives of the species and varieties, but yet sufficiently difficult and varied to bring into play the student's faculties which it was desired to cultivate. As aids, the student was allowed his lecture-notes, Dana's "System of Mineralogy," and the lecture-drawers of labeled minerals.
After sufficient time had been given for the laboratory-work, each student was expected to be questioned, during the lecture-hour, upon such specimens as the instructor chose from his drawer. The student was required not only to name the specimen, but also to give his proofs why this belonged to a certain species and not to any other.
After this laboratory work had been performed, the instructor passed on to the next group—the chlorides, etc., fluorides and oxides of Dana's system. Lectures with the succeeding laboratory work followed, but in the drawers for determination there were placed specimens not only of this group but also of the preceding group. This was followed throughout the year, so that the student was unable to lose sight of any species he had previously studied. Written examinations were occasionally interspersed, in which the student was required to determine a certain number of picked specimens that were placed before him, and write out the reasons for his determinations. This system of instruction, I believe, was devised by the teacher of the course at that time, Professor J. P. Cooke. After having endeavored to inform myself as to the methods of instruction in elementary mineralogy both in this country and in Europe, I have as yet failed to find one that, in my judgment, equals this, both for the mental discipline and the practical instruction it gives; and I take pleasure in acknowledging my great obligations and gratitude to Professor Cooke for the mineralogical instruction I received from him in that course.
When, in the process of time, this course passed under my charge, great modifications were made in it; the crystallography was reduced in amount and lithology added. By a different arrangement the crystallography was taught in six lectures. In these, by means of a few simple principles, the student was taught to recognize readily to which form the planes of any crystal belonged, no matter how many different forms might be represented. Further than this it did not seem practicable to go, without entering upon an extended course of instruction and practice in mathematical crystallography, which would have consumed the entire time of the course. However, it was found that the students were better trained for the practical application of crystallography to determinative mineralogy by this brief course than they had formerly been by the two and a half months' instruction previously given.
Another radical change was the substitution for the "general quiz" of all the students, at the lecture-hour, of an hour's oral examination for each student. Each one was required to arrange some hour in which he could meet the instructor alone in his room, with his (the student's) crystal models, or drawer of specimens, as the case might be. During that hour he was carefully questioned upon the material, and every effort was made to lead him to express his ideas clearly. He was cross-examined on every point, relating not only to general principles, but also to the particular specimens in hand. He was required to state what characters were upon the specimens, how he determined them, and what their relations were to others. If it was found that the student's methods were imperfect, his logic defective, or that he had misunderstood anything in the lectures) every effort was made to set him right. The examination was really made a pleasant conversation between two friends, in which one constantly endeavored to draw the other out, place him at his ease, and enable him to tell what he knew. Methods of thought and work were the great objects, far more than correctly naming the specimens. In such an examination as this the student was obliged to depend upon his merits. The teacher must have indeed been a poor one if he could not in that hour find out, to a far greater extent than the student dreamed or suspected, what he knew and what his methods of thought and work were. Every effort was made to render the student an independent thinker, to cultivate in him accuracy and quickness of observation and readiness of perception, to lead him to rely upon himself, to weigh evidence, to reason closely, to form an opinion, and give his reasons therefor to see, to be accurate, to reason, to judge, to decide. The time was also improved as a means of getting hold of him and establishing cordial relations with him; as well as to turn him unconsciously in the right direction, and to come into that close personal contact which it is so difficult to bring about in a large university, but which is so precious and valuable. Since these hourly examinations were repeated with each pupil for each group, the chief drawback was the tax upon the instructor's time and strength, as any one can readily realize when he considers that this species of mental gymnastics was kept up from six to ten hours a day, and that there were seven groups requiring from twenty-six to thirty hours in each group. It is to be borne in mind that this work was entirely voluntary on the instructor's part, but it paid in the results to the students, and in many of them it has influenced powerfully their after-life.
The students attending the course comprised freshmen, sophomores, juniors, seniors, graduates, specials, and scientific school students a perfectly natural result from the extended elective system of Harvard. I am free to confess that, for a course like the one above described, I much prefer freshmen and sophomores to juniors and seniors. The reason is not far to seek. The prime objects of such a course are to cultivate observation and accuracy, train the powers of reasoning and judgment, and above all to beget in the student independence and freedom of thought. The previous training of the upper-class men had usually been such as to cramp and weaken whatever faculties in these directions they might have originally possessed, and hence it was exceedingly difficult to stimulate them to right methods of work and thought. This was strikingly exemplified in the case of those students who were thoroughly conversant with the blow-pipe, from their previous study of chemistry. It was with the greatest difficulty that they could be prevented from taking some one of the numerous artificial blow-pipe keys for the determination of minerals, shutting their eyes to all the physical characters, transforming themselves into mere wind-machines, and mechanically grinding out their results.
One question will naturally arise in the minds of every one: Can similar methods be applied in giving instruction for a limited time when the means and appliances for determination are of themselves much circumscribed? In one case this has been practically answered by myself, in giving instruction in the rudiments of mineralogy and lithology in the Museum of Comparative Zoölogy. The problem was to take dust-covered minerals and rocks that had accumulated through many years—some good, but most of them mere rubbish, the odds and ends of various collections—and give a two and a half months' course. From the necessity of the case, no blow-pipes could be used in the building, there were no crystal models, and the whole apparatus for qualitative tests was a bottle of hydrochloric acid and a few test-tubes which could be used in the cold. Streakers, magnifying-glasses, magnets, and a knife or file, with some broken glass, completed the outfit. The miscellaneous collection of minerals and rocks was washed and sorted, and such specimens as could be used were labeled and placed in drawers accessible to the students. With this material it was impossible to arrange test-drawers as described in the previous course. The instructor then directed the attention of the students to those physical and chemical characters of the specimens that they could make use of. The same general system was pursued as before, so far as the different conditions would permit—the object being the same, to impart valuable instruction together with mental training. The students, under the direction of the instructor, worked over the labeled drawers, and determined for themselves why the specimens were labeled as they were. At the end of the course a series of minerals and rocks was placed before each student, and he was required to determine them, writing out his reasons therefor. The result far exceeded my expectations. Out of thirty-eight students examined, comprising freshmen, sophomores, juniors, seniors, graduates, special and engineering students, thirteen took over ninety per cent, three of whom had the maximum mark; twelve obtained over eighty per cent, five over seventy per cent, four between fifty and sixty per cent, and four between ten and fifty per cent.
That this course afforded an intellectual discipline of advantage to the student has been shown, among various ways, by the testimony of one of the sophomore students. His time later was largely devoted to philosophical studies, including language and history, and after graduation he pursued the same studies at Harvard and in the best European universities. After his return from Europe and his establishment as an instructor in his favorite branches, he informed me that this brief course had been of permanent advantage to him in his later studies, and that it was one of the very few of the courses taken in college upon which he could look back with any satisfaction and believe it had materially aided him both in mental discipline and in methods of study. I speak of this simply to fortify my claim that mineralogy when rightly taught affords in certain directions a most valuable means of intellectual training.
In most localities, especially in regions of crystalline rocks, the teacher, even with very limited means, can usually procure many specimens of at least a few species, which he can arrange for his students, and practice them upon in such a manner as to bring into play the required faculties. This method can even be pursued with large audiences, if specimens enough can be obtained.
Besides exercising the pupils on the selected collection, they should be encouraged to seek the specimens themselves in the field. Every means possible should be taken to develop in them methods of thought and work that will bear fruit in their future life. Far less should be thought of training mineralogists than of training men.
In giving advanced instruction, the secret seems to be to bring the student up to the level of the instructor; to see that he has a broad and thorough knowledge of the principles and necessary data of the science; to point out to him the untrodden fields; to strengthen and exercise him so that he may walk without the teacher's aid. The great aim should be to render the student independent in his thought and work, to free him from a slavish following after mere weight of authority, and to beget in him a desire to seek truth for its own sake. He should be so trained and strengthened that, when away from the instructor's aid, he can walk in the untried grounds with a firm and steady step.
The preceding has not been given as of necessity the most perfect way, but simply as a way for reaching certain results.
Far more, indeed, depends upon the teacher and his spirit than upon the method, however valuable the latter may be.
It may also not be amiss to call attention to certain requirements in the teacher. That an original investigator in any science may be a poor instructor in that science is too well known to be disputed, but I believe it to be equally true, that no man can teach any science in spirit and truth—can produce upon his pupils the effect that ought to be produced—unless he has the spirit and knowledge of an investigator himself. In truth, it is confidently believed that no man can be a teacher of the highest order who has not walked in the temple of mystery itself, and wrung from Mother Nature some of her closely-guarded secrets. As well ask one who has only read about disease to properly teach medical students the practice of medicine as to ask one who has only read about any science to give proper instruction to his students in it. Yet this is the thing which the majority of our colleges are doing, and they fill their chairs as if they thought a thorough training in any science disqualified a man for teaching it. And then we are told that science-teaching is a failure! Is not the failure more in the teachers chosen than in the subjects?