Methods for laboratory administration - Journal of Chemical Education

Methods for laboratory administration. Shirley Gaddis. J. Chem. Educ. , 1944, 21 (11), p 552. DOI: 10.1021/ed021p552. Publication Date: November 1944...
0 downloads 0 Views 1MB Size
Methods for Laboratory Administration SHIRLEY GADDIS Cranbrook School, Bloomjield Hills, Michigan

T

HE following ideas about the administration of is too frequently contaminated. Organic liquids which student laboratories are collected here in the hope are sold in sealed ampoules should be purchased in the that they may be of help to those teachers who are smaller sizes. I t is usually better economy to order just beginning to administer laboratories: eight 25-gram ampoules than to get one 200-gram size. 1. The best system of accounting laboratory equip- The extra cost is less than the evaporation waste from ment which I have used is the "trade-chip" method. the large sizes, which may have to stand for months Each student purchases a $5.00 punch card. As extra partially sealed. equipment is checked out from the storeroom the value 4. Piped H2S is a never-ending wony to a teacher of the equipment is punched from the card. Upon of a qualitative laboratory. The need for frequently returning the equipment the student is given his credit checking the supply of gas in the tanks, leaky fittings in the form of plastic trade-chips embossed with the with the attendant waste and health hazard, and the name of the laboratory and the value of the chip in amount wasted by the students are all exasperating. trade. The student uses these chips to check other These difficulties can be overcome by giving to each items as the need arises. All bookkeeping is obviated student a semimicro generator for his personal use. by the use of this method. I have been told that this 5. Trap trouble in laboratories can be most satissystem originated a t the University of Pittsburgh. factorily solved by not having any traps on the desks. 2. For very small schools in which the student- Instead there should be a single master trap to take teacher relationship can be on a friendly basis i t is care of an entire laboratory. 6. A properly waxed linoleum makes an excellent often best not to use any system of student accounts in the stockroom. The student is given a punch card and desk top for laboratories. The color of this desk free access to any equipment he needs. Whenever he covering serves to enliven the appearance of the breaks any equipment he is to punch out the value of laboratory. the piece on the card. At the end of the year he pays 7. Shelves on chemistry benches are of debatable what he has punched out. value. Sometimes their chief function seems to be as a To study student honesty the author carried out the resting place for odds-and-ends of bottles, apparatus, above plan for three years in a small college. A careful books, etc. A tray 2 X 10 inches filled with two-ounce inventory was made of all the equipment a t the begin- Barnes bottles is a neater solution. ning and a t the end of the year to ascertain the loss by 8. The chemicals to be used in the day's experiment breakage. should be assembled in one place. The bottles should At the beginning of the year the system was ex- be without their caps. The bottles of liquids should plained to each section with the remark that each stu- have a length of glass tubing in them to serve as a pipet dent would be on his own honor. Even if dishonesty to expedite the transfer of the liquid to the student's were suspected nothing would be said. Many people test tube. think they are honest when actually they fear the con9. Cheap, satisfactory labels can be made by using sequences of being caught. This was to be an excellent the gummed h a f t stock that is sold in rolls. Formulas opportunity for each student to find out for himself should be printed on this paper in large green or red whether or not he would be dishonest if a chance were letters using a broad-tip pen. A good label varnish is afforded. It was felt that this opportunity for self- made by adding toluene to Vinylite. appraisal was a valuable part of this system. 10. Squares of wax paper are a good substitute for The results of the three-year study were that on the the procelain spot plates. 11. There should be one-half-gallon crocks for average $35 worth of equipment could not be accounted for a t the inventory. This was for an average of 68 solid wastes on each desk within reaching distance of students each year. Since by using this system no each student. This will help to keep the troughs free stockroom help had to be hired, money was saved. from solids. 3. Liquid reagents should be purchased for the 12. Gummed paper labels 2 X 3 inches printed laboratory in the five-pint screw-cap bottles and not with the name of the department, and spaces for the in carboy lots. The economy of the carboy lot is il- name of the pupil, the date, the preparation with lusory. In transfemng the liquid from carboy to re- yield, or the report of an unknown, and the initials agent bottles the labor involved, the liquid lost, and of the instructor are useful in keeping books on the the possibility of contamination more than offset the student's work. After the label has been completed money saved on the carboy lot. for some preparation or unknown and it has been C.P. chemicals should be purchased in small bottles initialed by the instructor or stockroom clerk, then only, never in the five-pound bottles. The large bottle i t is to be pasted in the report of the experiment. 552