College Teaching Part 12

=Place of physical chemistry in the college curriculum=

Physical chemistry, commonly regarded as the youngest and by its adherents the most important and all-pervading branch of chemistry, is presented very early in the college course by some teachers, and postponed to the junior and even the senior year by others. Just as a certain amount of organic chemistry should be taught in the first year, so a few of the most fundamental principles of physical chemistry must also find a place in the basal work of the beginner.

However, in the first year's work in chemistry so many phases of the subject must needs be presented in order to give a good general view, that many details in either organic, a.n.a.lytical, or physical chemistry must necessarily be omitted. What is to be taught in that important basal year must, therefore, be selected with extreme care. Moreover, so far as physical chemistry is concerned, it is in a way chemical philosophy or general chemistry in the broadest sense of the word, and consequently requires for its successful pursuit not only a basal course, but also proper knowledge of a.n.a.lytical and organic chemistry, as well as a grounding in physics, crystallography, and mathematics.

At the same time a certain amount of biological study is highly desirable. A good course in physical chemistry postulates lectures, laboratory work, and recitations. In general, these should be arranged much like those in the basal course and the course in organic chemistry. If anything, more time should be put upon the lectures and recitations; certainly more time should be devoted to exercises of this kind than in the course in quant.i.tative a.n.a.lysis, which is best taught in the laboratory. At the same time it would be a mistake to teach physical chemistry without laboratory practice. Indeed, laboratory practice is the very life of physical chemistry, and the more of such work we can have, the better. However, since physical chemistry, as already stated, delves into the philosophical field, discussions in the lecture hall and cla.s.sroom become of peculiar importance.

=Courses in applied chemistry=

Many colleges now give additional courses in chemical technology.

These would naturally come after the student has had a sufficient foundation in general chemistry, chemical a.n.a.lysis, and organic and physical chemistry. As a rule such applied courses ought not to be given until the junior or senior year. It is a great mistake to introduce such courses earlier, for the student cannot do the work in an intelligent manner.

=Enthusiastic teaching a vital factor=

In all the courses in chemistry, interest and enthusiasm are of vital importance. These can be instilled only by the teacher himself, and no amount of laying out courses on paper and giving directions, however valuable they may be, can possibly take the place of an able, devoted, enthusiastic teacher. Chemistry deals with things, and hence is always best taught in the laboratory. The cla.s.sroom and the library should create interest and enthusiasm for further laboratory work, and in turn the laboratory work should yield results that will finally manifest themselves in the form of good written reports.

=The teacher must continue his researches=

Original work should always be carried on by the college teacher. If he fails in this, his teaching will soon be dead. There will always be some bright students who can help him in his research work. These should be led on and developed along lines of original thought. From this source there will always spring live workers in the arts and industries as well as in academic lines. Lack of facilities and time is often pleaded by the college teacher as an excuse for not doing original work. There is no doubt that such facilities are often very meager. Nevertheless, the enthusiastic teacher is bound to find the time and also the means for doing some original work. A great deal cannot be expected of him as a rule because of his pedagogical duties, but a certain amount of productive work is absolutely essential to any live college teacher.

=Future of chemistry in the college curriculum=

The importance of chemistry in daily life and in the industries has been increasing and is bound to continue to increase. For this reason the subject is destined to take a more important place in the college curriculum. If well taught, college chemistry will not only widen the horizon of the student, but it will also afford him both manual training and mental drill and culture of the highest order.

LOUIS KAHLENBERG _University of Wisconsin_

VI

THE TEACHING OF PHYSICS

The need of giving to physics a prominent place in the college curriculum of the twentieth century is quite universally admitted. If, as an eminent medical authority maintains, no man can be said to be educated who has not the knowledge of trigonometry, how much more true is this statement with reference to physics? The five human senses are not more varied in scope than are the five great domains of this science. In the study of heat, sound, and light we may strive merely to understand the nature of the external stimuli that come to us through touch, hearing and sight; but in mechanics, where we examine critically the simplest ideas of motion and inertia, we acquire the method of a.n.a.lysis which when applied to the mysteries of molecular physics and electricity carries us along avenues that lead to the most profound secrets of nature. Utilitarian aspects dwindle in our perspective as we face the problem of the structure, origin, and evolution of matter--as we question the independence of s.p.a.ce and time. Modern physics possesses philosophic stature of heroic size.

=Utilitarian value of the study Of physics=

But with regard to everyday occurrences a study of physics is necessary. It is trite to mention the development in recent years of those mechanical and electrical arts that have made modern civilization. The submarine, vitalized by storage battery and Diesel engine, the torpedo with its gyroscopic pilot and pneumatic motors, the wireless transmission of speech over seas and continents--these things no longer excite wonder nor claim attention as we scan the morning paper; yet how many understand their mechanism or appreciate the spirit which has given them to the world?

=Disciplinary value of the study=

If culture means the subjective transformation of information into a philosophy of life, can culture be complete unless it has included in its reflections the marvelously simple yet intricate interrelations of natural phenomena? The value of this intricate simplicity as a mental discipline is equaled perhaps only in the finely drawn distinctions of philosophy and in the painstaking statements of limitations and the rapid generalizations of pure mathematics; and let us not forget the value of discipline, outgrown and unheeded though it be in the acquisitive life of the present age.

=Relation of physics to philosophy and the exact sciences=

The professional student, continually increasing in numbers in our colleges, either of science or in certain branches of law, finds a broad familiarity with the latest points of view of the physicist not only helpful but often indispensable. Chemistry can find with difficulty any artificial basis for a boundary of its domain from that of physics. Certainly no real one exists. The biologist is heard asking about the latest idea in atomic evolution and the electrical theories of matter, hoping to find in these illuminating points of view, he tells us, some a.n.a.logy to his almost hopelessly complex problems of life and heredity. Even those medical men whose interest is entirely commercial appreciate the convenience of the X-ray and the importance of correctly interpreting the pathological effects of the rays of radio-activity and ultra-violet light. One finds a great geologist in collaboration with his distinguished colleague in physics, and from the latter comes a contribution on the rigidity of the earth. Astronomy answers nowadays to the name of astrophysics, and progressive observatories recognize in the laboratory a tool as essential as the telescope. In a word, the professional student of science not only finds that the subject matter of physics has many fundamental points of contact with his own chosen field, but also recognizes that the less complex nature of its material allows the method of study to stand out in bolder relief. Training in the method and a pa.s.sion for the method are vital to a successful and an ardent career.

=Should the teaching of college physics change its aim for different cla.s.ses of students?=

In the teaching of physics, then, the aim might at first sight appear to be quite varied, differing with different cla.s.ses of students. A careful a.n.a.lysis of the situation, however, will show, we think, that this conclusion can with difficulty be justified: that it is necessary to conduct college instruction in a fas.h.i.+on dictated almost not at all by the subsequent aims of the students concerned. In the more elementary work, certainly, adherence to this idea is of great importance. The character, design, and purpose of an edifice do not appear in the foundations except that they are ma.s.sive if the structure is to be great.

Not infrequently this seems an unnecessary hards.h.i.+p to a professional student anxious to get into the work of his chosen field. If such is the case, let him question perhaps whether any study of physics should be attempted, as this query may have different answers for different individuals. But if he is to study it at all, there is but one place where the a.n.a.lysis of physical phenomena can begin, and that is with fundamentals--s.p.a.ce, time, motion, and inertia. How can one who is ignorant of the existence and characteristics of rotational inertia understand a galvanometer? How can waves be discussed unless in terms of period, amplitude, frequency, and the like, that find definition in simple harmonic motion? How does one visualize the mechanism of a gas, unless by means of such ideas as momentum interchange, energy conservation, and forces of attraction?

Let us emphasize here, lest we be misunderstood, that we are considering collegiate courses. We do not doubt that descriptive physics may be given after one fas.h.i.+on to farmers, quite differently to engineers, and from still a third point of view to medical students. Unfortunately some collegiate courses never get beyond the high school method. Our aim is not to discuss descriptive courses, but those that approach the subject with the spirit of critical a.n.a.lysis, for these alone do we deem worthy of a place in the college curriculum.

=The course in college physics differentiated from the high school course=

The problem of the descriptive course is the problem of the high school. Because of failure there, too often we see at many a university courses in subfreshman physics. These are made necessary where entrance requirements do not demand this subject and where subsequent interest along related lines develops among the students a tardy necessity of getting it. From the point of view of the collegiate course it often appears as if the subfreshman course could be raised to academic rank. This is because familiarity with the material must precede an a.n.a.lysis of it. Credit for high school physics on the records of the entrance examiner, unless this credit is based on entrance examination, is often found to stand for very little. Consequently the almost continual demand for the high school work under the direct supervision of a collegiate faculty. The number of students who should go into this course instead of the college course is increasing at the present time in the immediate locality of the writer.

As contributory testimony here, witness the number of colleges that do not take cognizance at all of high school preparation and admit to the same college cla.s.ses those who have never had preparatory physics with those who have had it. We are told the difference between the two groups is insignificant. Perhaps it is. If so, this fact reflects as much on the college as on the high school. If we are looking for a solution of our problem in this direction, let us be undeceived; we are looking backwards, not forward.

=Need of adequate high school preparation in physics=

No one will affirm that to a cla.s.s of whose numbers some have never had high school physics a course that is really a.n.a.lytical can be given. Wherever a rigorous a.n.a.lytic course is given those who have been well trained in descriptive physics do well in it in general. Let us not beg the question by giving such physics in a college that does not require high school preparation. The college curriculum is full enough as it is without duplication of high school work, and any college physics course that is a first course is essentially a high school course.

Let us rather put the responsibility squarely where it lies. The high school will respond if the urgency is made clear. Witness some of them in our cities already attempting the junior college idea, an idea that has not been unsuccessful in some of our private schools. If it is made clear that a thoroughgoing course in descriptive physics is a paramount necessity in college work and that no effort will be spared on the part of the university to insure this quality, the men will be found and the proper courses given.

=Preparatory work in mathematics essential for success in college physics=

We favor a comprehensive examination plan in all cases where the quality of the high school work is either unknown or open to question.

Familiarity, likewise, with the most elementary uses of mathematics should be insured. It would be highly desirable that a course of collegiate grade in trigonometry should immediately precede the physics. This is not because the details of trigonometry are all needed in physics. In fact, a few who have never had trigonometry make a conspicuous success in physics. These, however, are ones who have a natural facility in a.n.a.lysis. To keep them out because of failure to have had a prerequisite course in trigonometry often works an unnecessary hards.h.i.+p. We would argue, therefore, for a formal prerequisite on this subject, reserving for certain students exemption, which should be determined in all cases, if not by the instructor himself, at least by his cooperation with some advisory administrative officer.

=Need of testing each student's preparation=

Nor is it sufficient with regard to the mathematical preparation or the knowledge of high school physics in either case to go exclusively by the official credit record of the student. It is our firm conviction from several years' experience where widely different aims in the student body are represented that above and beyond all formal records attention to the individual case is of prime importance. The opening week of the course should be so conducted that those who are obviously unequipped can be located and directed elsewhere into the proper work. How this may best be accomplished can be determined only by the circ.u.mstances in the individual school, we imagine. Daily tests covering the simplest descriptive information that should be retained from high school physics and requiring the intelligent use of arithmetic, elementary algebra, and geometry will reveal amazing incapacity in these things. Tuttle, in his little book ent.i.tled _An Introduction to Laboratory Physics_ (Jefferson Laboratory of Physics, Philadelphia, 1915), gives on pages 15-16 an excellent list of questions of this sort. Any one with teaching experience in the subject whatever can make up an equally good one suited for his special needs and temperament. It should not be a.s.sumed that all who fail in such tests should be dropped. Some undoubtedly should be sent back to high school work or its equivalent; others may need double the required work in mathematics to overcome their unreadiness in its use.

Personal contacts will show that some are drifting into a scientific course who have no apt.i.tude for it and who will be doomed to disappointment should they continue. In a word, then, we are convinced that the more carefully one plans the work of the first week or so the more smoothly does the work of the rest of the year follow. The number of failures may be reduced to a few per cent without in any way relaxing the standard of the course.

=Methods of teaching college physics=

With regard to the organization of the college courses in physics there seems to us to be at least one method that leads to a considerable degree of success. This is not the lecture method of instruction; neither is it a wholly unmitigated laboratory method.

=Lecture method vs. laboratory method=

To kindle inspiration and enthusiasm nothing can equal the contact in lectures with others, preferably leaders in their profession, but at least men who possess one of these qualities. Such contacts need not be frequent; indeed, they should not be. The speaker is apt to make more effort, the student to be more responsive, if such occasions are relatively rare. Even thus, although real information is imparted at such a time, it is seldom acquired. However, perspective is furnished, interest stimulated, and the occasion enjoyed.

=Limitations of exclusive use of each method=

For the real acquisition of scientific information, the great method is the working out of a laboratory exercise and pertinent problems, with informal guidance in the atmosphere of active study and discussion engendered among a small group,--the laboratory method.

Taken alone, it is apt to become mechanical and uninteresting and the outlook to be obscured by details. Lectures, especially demonstration lectures, are needed to vitalize and inspire. Moreover, many of the most vivid ill.u.s.trations of physical principles that occur on every hand to focus the popular attention are never met with in the college course because they are unsuited for inexperienced hands or not readily amenable to quant.i.tative experimentation. The more informally such demonstrations can be conducted, the more enthusiastically they are received.

=Aims of the laboratory method=

With regard to laboratory work, accuracy in moderate degree is important, but too great insistence upon it is apt to overshadow the higher aim; namely, that of the a.n.a.lysis of the phenomena themselves.

A determination of the pressure coefficient of a gas to half a per cent, accompanied by a clear visualization of the mechanism by which a gas exerts a pressure and a usable identification of temperature with kinetic agitation, would seem preferable to an experimental error of a tenth per cent which may be exacted which is unaccompanied by these inspiring and rather modern points of view. Especially in electricity is a familiarity with the essentials of the modern theories important.

Here supplementary lectures are of great necessity, for no textbook keeps pace with progress in this tremendously important field. Problem solving with cla.s.s discussion is absolutely essential, and should occupy at least one third of the entire time. In no other way can one be convinced that the student is doing anything more than committing to memory, or blindly following directions with no reaction of his own.

=Value of the supplementary lecture=

The incorporation recently of this idea into the courses at the University of Chicago has been very successful. Five sections which are under different instructors are combined one day a week at an hour when there are no other university engagements, for a lecture demonstration. This is given by a senior member of the staff whenever possible. The other meetings during the week are conducted by the individual instructors and consist of two two-hour laboratory periods and two cla.s.s periods that usually run into somewhat over one hour each. These sections are limited to twenty-five, and a smaller number than this would be desirable. The responsibility for the course rests naturally upon the individual instructors of these small sections.

These men also share in the demonstration work, since each is usually an enthusiast in some particular field and will make a great effort in his own specialty to give a successful popular presentation of the important ideas involved. The enthusiasm which this plan has engendered is very great. Attendance is crowded and there is always a row of visitors, teachers of the vicinity, advanced students in other fields of work, or undergraduates brought in by members of the cla.s.s.