This New 48-Page Vacuum Pump Catalog FREE On Request
THE
ANALYST'S COLUMN
Contains a complete description, including performance of Welch Duo-Seal Pumps ranging from 21 Liters to 375 Liters per minute, as well as a greatly enlarged listing of Diffusion Pumps, Vacuum Gauges and Accessories.
L. T. HALLETT, Science Editor T^HB Pittsburgh Conference on Analytical Chemistry and Spectroscopy this year, as usual, was a successful and in teresting meeting, with the exhibits affording an informative respite from convention papers. The symposium on statistics attracted a large audience, and we were impressed by the many uses of statistics in scien tific and production control. This is in contrast to a symposium held in 1947 at the Atlantic City meeting of the ACS, when many of the speakers were nonACS members, outside the field of chemistry or chemical engineering. The use of statistics in science has grown steadily over the past few years, and, with all its imperfections, it shows how human error can be checked and quality of product maintained. Every scientific worker who collects scientific data from his own or others' experiments many times is ignorant of how the data were obtained and how accurate and precise are the measure ments. He therefore may draw errone ous conclusions from experiments which are extensive and of long duration. Statistical treatment of data from ex periments which are designed through statistical methods will give much greater validity to the results. In the realm of the practical, the plant control laboratory analyst is proud of his tech nique and method, to the point where through ignorance he places greater faith in his results than is justified. The plant production man is inclined to doubt the analyst and put more faith in his process. It is in these areas that the intelligent use of statistics has opened the eyes of both the analyst and the production superintendent. By use of control points and blind samples the analytical laboratory is able to judge its own limitations. It is heartening to note that with statistical control the analyst has come to look upon the use of blind samples as a means of helping him do a better job and not in the spirit of showing how poor is his technique. Often the method is not so VOLUME
2 7, N O . 4, A P R I L
1955
If you do not have your Copy WRITE FOR IT NOWI W . M. WELCH SCIENTIFIC COMPANY DIVISION
O F W . M . WELCH MANUFACTURING
ESTABLISHED
COMPANY
7880
1 5 1 5 Sedgwick Street, Dept. A - 1 , Chicago 1 0 , Illinois, U. S.A. Manufacturers
of Scientific Instruments and Laboratory
Apparatus
For further information, circle number 13 A-1 on Readers' Service Card, page 47 A
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For further information, circle number 13 A-2 on Readers' Service Card, page 47 λ
13 A
