LETTERS Savings in Semimicro Methods for t h e Beginning Student
To the Editor: In the September, 1941, issue of this JOURNAL appeared an article' on the use of semimicro procedures in the first-year college chemistry course, which originatedfrom the Mars Hill College Chemistry Laboratory. Since this article was written i t has been possible to calculate some savings in this field over the old macro method. Due to interest shown in the September article we would like to give below our figures, together with some explanation. 1. Cost of desk apparatus-semimicro, $6.19 per student. Cost of desk apparatus-macro, $9.03 per student. A saving of $2.84 per student or a 32 per cent saving. In a class of 200 students this amounts to a saving of S68.00.
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WOODAND WALKER,"Semimino chemistry far the beginning student," J. &EM. EDUC., 18, 427 (Sept., 1941).
2. A 66.77 per cent saving in solid reagents in semimicro over macro methods. 3. A 22.93 per cent saving in liquids and solutions in semimicro over macro methods. 4. This is a total saving of 42.09 per cent on all chemicals used in changing from macro to semimicro methods.
In the compilation of the above figures we used a macro laboratory manual, considered one of the best in the field, that we had used in previous years, along with the semimicro manual that we developed in our own department. As was pointed out previously1 the experiments for the beginning student are not radically different and so there would be no savings due to complete revision of fundamental laboratory training. The only difference is in the size of the equipment and the quantities of the reagents used. The above are the tangible savings. Perhaps just as important are savings of an intangible nature. Some of these are listed as follows:
1. Savings due to less waste of chemicals. In any laboratory course there will be waste of chemicals, that is, a student will use more material than is necessary according to the directions in the manual. We have found that the student using small equipment tends to use the amount called for much more readily than in the macro method. The reason is obvious to those who have tried it. A large quantity of material just does not seem to look right in small equipment. 2. Savings in time. Time in the laboratory is an important item, especially for the beginning
student. In the semimicro method the same type of experiment can be performed in a much shorter period, meaning that the student can complete more experiments and thereby receive more training. 3. A saving of working space, thereby allowing more students in the laboratory per section. 4. A saving of cabinet space, thereby allowing a school to put more student cabinets inaa laboratory. H. RAWORTH WALKER, JR. Mnns HILL COLLEGE
MARS HILL,NORTH CAROLINA
