SUPERSPEED SERVALL REFRIGERATED CENTRIFUGE 16,000 rpm—32,700 χ G for Continuous as well as Batch Operations Continuous Flow adaptation now designed into the SERVALL Superspeed Refrigerated Centrifuge, brings time- and trouble-saving versatility to low-temperature centrifugation. By use of the SERVALL "SzentGyorgyi—Blum" Continuous Flow Attach ment, large volumes of sample may be centrifuged at a flow rate of up to 200 ml per minute without the laborious process of doing the job "a rotor-full at a time." Sediment is collected in one, two, four, or eight tubes, while supernatant is drained off as it is clarified. Temperatures of —0°C. may be established, and held within ± 1 ° C . In addition to the SS-1 rotor with Continuous Flow adaptation, ten versatile rotors for batch work may be used in the stainless steel evaporating chamber. The largest of these has a maximum operating capacity of 1,770 ml.·—Wide speed range—dual automatic con trols—exclusive Self-Centering Assembly— still the lowest-priced Refrigerated Centrifuge in the Superspeed Range.
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Write for Bulletin AC-11R
Ivan
Sorvall,
Inc.
DESIGNERS, MANUFACTURERS A N D DISTRIBUTORS O F " S E R V A l f LABORATORY INSTRUMENTS
Since Τ 9 43 the Wortd's largest manufacturer of Superspeed Centrifuges. For further infonnation, circle number 26 A-1 on Readers' Service Card, page 73 A
ideal for: • GENERAL LABORATORY WEIGHINGS • A PREWEIGHER to speed results and save wear and tear on analytica! balances. •
C A P A C I T Y . . , 3 1 ! gram
•
SENSITIVITY . . . 01 gram ( 1 centigram)
tor romptetv Information irrite tor brorhurr
OHAUS
SCALE
CORPORATION
lOSO COMMERCE AVE. UNION, NEW JERSEY . For further information, circle number 26 A-2 on Readers' Service Card, page 73 A 26 A
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ANALYTICAL CHEMISTRY
REPORT FOR ANALYTICAL CHEMISTS student has had all the basic courses, chemical and instrumental. It has tobe made clear to him that all these approaches are interrelated and all have to be considered toward the solution of a problem. Thus the history of un knowns can become more sparse, the laboratory and verbal problems more diffuse, so that the student can find no clear-cut procedure in his experi ence or in the literature. He has to begin to exercise his evaluation and selection processes to a higher degree, and this will force him to look at all the available analytical approaches. This also will develop the individual's ability to be original along analytical lines, which is desirable at this stage of his education. The type of instruction outlined puts an increased burden on the teacher. He has to devote more individual time with each student in the laboratory. Also, the recitation and examination questions will require more prepara tion. In addition, the best instructors for the program outlined are men whose field is analysis and who are sincerely interested in their field. It occasionally happens that the courses in analysis are handled by men whose field is organic, inorganic, or physical chemistry. The analytical course in such cases can be assumed as a "chore"; hence the necessary enthusiasm is lack ing. In addition, these instructors are often not well informed on analysis as it exists today. Thus courses in organic analysis as given by organic chemists tend to become courses in organic chemistry. Instrumental anal ysis courses as given by physical chem ists or physicists tend to emphasize the physical instrument as such and not as an analytical tool. Summary The teaching of analytical chemistry should go beyond the teaching of the use of the analytical approaches and the necessary fundamental background information. The student should also be instructed in the handling of an alytical problems and the instruction should be such that the student's in herent reasoning powers are exercised along chemical analytical lines. The teaching approaches mentioned are directed at exercising the student's thought processes. At the same time, having to work a bit at getting his information, the student is getting a firmer grasp of the technical aspects of what he has been taught and he will no doubt bring into play some of the chemical and other information gained from other course work. This leads to not only a better analyst but a better student.
