Shall laboratory periods be shortened? - Journal of Chemical

Harvey C. Brill. J. Chem. Educ. , 1930, 7 (4), p 909. DOI: 10.1021/ .... Building better chloride sensors. Natural protein glows when binding to ch...
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SHALL LABORATORY PERIODS BE SHORTENED? Every now and then, for some unaccountable reason, an urge appears among certain of our colleagues to make a change in the old order of doing things. So long as i t is a change, many conclude that i t must be a reform and improvement, and that those who counsel caution until proof has been presented that the change is desirable, are confirmed mossbacks. One of the more recently proposed innovations is to shorten laboratory periods from the traditional three hours to two hours for the beginning students in the various laboratory sciences. A number of arguments for the adoption of two-hour laboratory periods are given. These will be presented and the endeavor made to refute, and to show them to be invalid or without serious value. Now this privilege is not to be extended to those students who are carrying laboratory courses advanced beyond the beginning one. The latter are to do three hours' laboratory work for one semester hour of college credit; the beginner only two for the same number of credits. When the illogic of this plan is pointed out, i. e., that the more advanced student with laboratory experience is being asked to perform one and one-half times as much for his credit, and that the more logical arrangement would be to reverse the requirements, they nayvely reply, that the student should not emphasize the importance of credits and besides aren't the second- and third- and fourth-year men in the sciences taking these subjects because they want to or because they must? Well, the beginner is taking the course for the saine reasons-as nearly as these reasons can be analyzed-because he expectedto major in the subject, enter a profession in which i t is a requirement to meet the college demands that he study a laboratory science in order to earn a degree, or finally because he was placed there by the person who registered him. These reasons for electing the course would hardly warrant the extension of any favors to him that should be withheld from his older, college brother. The writer is enough of a Jeffersonian Democrat to wish that every man on a faculty be granted as much freedom in the policy of his department as can be given without hann to the general welfare of the institution. However, the permission to one department to give an hour credit for two hours of laboratory work is a permission that concerns not only that department but every other one on the campus. The custom has been to require three hours' laboratory work for one college semester credit and any change in this policy should be taken with the publicly expressed approval of the faculty. Furthermore, the requirement of two hours' preparation for every hour of classroom performance or a total of three hours has been presented to students as a necessary minimum requirement for earning a college credit. Now if two hours of laboratory work earn one college credit, does it not seem illogical, possibly even unfair, to ask two hours

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of preparation for every classroom lesson? Can less preparation be safely given to a lesson with assurance of a creditable showing in a course? But isn't there a certain unfairness if we adopt two-hour periods for the laboratory and assign lessons that require two hours of preparation? Those institutions that place little stress on credits but have a requirement of a final comprehension examination to test the student's accomplishment are relieved of this problem. That students value college credits is not to be wondered a t when one considers the importance attached to them by their teachers. They must earn one hundred and twenty-four semester college credits for a diplomaa faculty ukase. When one proposes that in fairness the credit for two-hour laboratories be two-thirds of an hour, the suggestion is met wiWthe objection that this would introduce common fractions into the registrar's office. If fractions are as difficult for registrars as they are for the students in beginning chemistry, the objection is a valid one. On the other hand, I am certain that the students in the more advanced courses will object to the disproportion in credits earned. Could I be assured that the adoption of the two-hour laboratories limited to beginners would arouse the ire of the other students to a pitch whereby a reform of the present credit system would result, I might consider advocating its adoption. Another argument for the two-hour laboratory period is that students waste too much time in the three-hour period and that they can do as much work in the two. A waste of time&y students certainly can be corrected by the instructor in charge. If he is unable to do so for the threehour period, how will he succeed in the two? As to the relative amounts of work accomplished-in one case there is one and one-half times as much time for work-surely a student can do more in three hours than in two. However, the disparity in time that is devoted to actual laboratory work is greater than actually appears a t ?%st sight. Let us analyze a few of the activities of the student in the laboratory. The average laboratory period goes somewhat like this: the student spends ten minutes opening his locker, selecting his apparatus for the experiment and listening to any general instructions from the laboratory instructor; ten minutes consulting his laboratory manual; .in case he needs a piece of apparatus not in his desk, another ten minutes getting it from the storeroom: two or three weighings will require ten minutes time from the beginner; and dismantling set-ups, washing apparatus and the desk top a t the end of the period, etc., can easily consume twenty minutes-a total of one hour. One hour remains from the two-hour and two hours from the three-hour laboratory. The time for experimental work is not one and one-half but two times as much for the three-hour period; a most favorable situation for the three-hour period that too often receives no appreciation. This is

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exclusive of the time needed for making some sort of notebook record of the experiment. The writer believes that to insure that these records be the student's own independent work, they should be made before the student leaves the laboratory. The student then has the advantage of consultation with the instructor in case any point of the day's assignment is obscure. If fifteen or twenty minutes are used for this purpose we now have less than half as much time in the two-hour laboratory period as in the three-hour laboratory period available for laboratory experimentation. That students cannot concentrate for three hours is an objection presented. Can they for two hours? The usual laboratory work is varied enough in character that the student's mind is diverted and the longer period, since it promotes a somewhat leisurely attitude, is not so wearisome mentally. It gives time for a consideration of the purposes and results of the experiments, which the two-hour period certainly does less adequately. The shortened period will discourage the inclusion of experiments with somewhat complicated set-ups and reactions that require time for completion. These are those which illustrate the important principles of the science and exercise the student in manipulation so that he acquires skill in this phase of the science. I am not opposed to a shortened period for those students who accomplish the assignment in less than the average time, but when the period is shortened to two hours it becomes more difficult to observe any discrimination for the able, average, and dull students. 'with the educational program as it is, the State Schools a t least have all these classes and have an implied obligation to do their best by all three classes. The three-hour period possesses an elasticity that is absent from the two-hour period. If the two-hour period is organized to occupy the time of the able student, how about the average and the dull? If organized for the average, how about the able and the dull? I refuse to consider the possibility that i t should be planned primarily for the dull. I appreciate that every student should be treated as a special problem and his work planned with him, but with the teaching staff of the present size, this is an impossible taskwith the beginners a t least. But when i t is found that the average students are able to complete the assigned work in the two hours, only under high pressure, and the dull students not a t all, the normal inclination of the instructor will be to lighten the assignments or accept work of a lower quality, and the standard of the work of the college will be lowered just that much. If the two-hour period is adopted, this lowering will take place just as soon as the zeal of the advocates for the change has cooled. The disadvantages of the two-hour laboratory courses and the obvious advantages of the three-hour laboratory period which have been presented,

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seem to me to justify the retention of the latter plan and the rejection of the fornier. The writer realizes that the advocates of the two-hour plan may have some data that have not been brought to his attention. He is always willing, nay, anxious to be informed. HARVSYC. BRILL MIAXI UNIVERSITY OxaORD. OHIO Scientific Investigations of Spontaneous Combustion Proposed. The strange phenomenon of hay racks catching fire through no human agency was recognized as a natural process by wise men of old Rome, and yet two thousand years later the process is still as baffling and inexplicable t o modern science as it was t o Columella and Pliny. Citing the knowledge of ancient observers regarding spontaneous combustion, Dr. Henry G. Knight, chief of the U. S. Bureau of Chemistry and Soils, speaking before the recent conference on Spontaneous Heating and Ignition of Agricultural and Industrial Products, outlined a program of scientific research which would solve the mystery and enable mankind to forestall the destructive process. of the exact conditions that ~ r a d n c e "There is evident need of careful investigation . the spontaneous ignition of agricultural materials as the basis for our future course of action. It will reauire a mn~erativeinvestigation by chemists, bacteriologists, and engineers upon quantities of materials sufficiently large to duplicate actual farm conditions." Outlining the points requiring special attention, he said: "Chemical analyses should he made of the fresh material and the chemical changes which take place throughout the heating period should he noted carefully. The rate of heating in different parts of the mass should be determined. The avidity for oxygen of the fresh and fermented material should he studied. The migration of moisture throughout different parts of the experimental rnater&l should be carefully observed. The production of gases and their character should receive study. The effects of aeration a t various stages of storage should be recorded. Studies of conditions existing in the areas of high heats should he carried on, and the various methods of curing in the case of hay and the effects of adding other substances such as salt to hay and t o cattle feed should receive special study. Along with this work and based upon it should be studies of methods directed a t the reduction of spontaneous heating and actual firing of agricultural materials." Spontaneous ignition costs American farmers millions of dollars a year, and the chief products which go up in smoke or are spoiled for use by this cause are hay, grain, and horse manure.-Science Service

Five Hundred Tons of Aspirin a Year. Deaths from poisoning hy aspirin (says the Pharmaceutical Journal) are on the increase in England and Wales a m d i n g t o the Statistical Review of the Registrar-General. This is not surprising in view of the quantities of the drug (500 tons a year, according t o Dr. Dishingou) consumed in this country. The significant fact is that there has been a big jump in aspirin fatalities. I n 1927, five people met their deaths, by intent or accident, through taking aspirin, while in the year before there was no recorded case. In 1928 the number was seventeen -ten accidents and seven suicides. That there is a moral to draw from these figures is obvious.-Chm. N m s