PUNCH CARDS IN CORRELATION STUDIES - C&EN Global

Nov 4, 2010 - ... and such a wide variety of constituent groups, counting and correlating the data by inspection promised to be a formidable task. The...
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the University of Michigan a n d received the P h . D . degree from the University of California in 1929. H e has been a m e m ber of the ACS since 1923. He was awarded the Langmuir Prize o f the SOCIETY for his work in pure chemistry in 1933. After a period abroad on a Guggenheim Fellowship and two years at Cornell University, h e came t o the Iowa State College in 1937 t o head the department of physical chemistry. Assisting Spedding as associate project director was Harley A. Wilhelm, professor of physical metallurgy at the college. In response to the request of t h e Government in February 1942, Spedding and Wilhelm devised the Ames process of making uranium metal in cooperation with W. H . Keller, later in charge of chemical metallurgy, and C. F. Gray, later in charge of metal casting, and carried the process through pilot-plant operation and into full-scale production. By early 1943 uranium metal was being shipped from the campus in carload lots. Prior to t h e work at Ames, uranium metal was being produced elsewhere, but the methods in use were cumbersome, highly expensive, and poorly adapted to large-scale manufacture and t h e product was not of the purity desired. The Ames process is simple and inexpensive and yields a product of exceedingly high purity. T h e saving to the Government on the hundreds of tons of uranium finally produced has been enormous. Although the initial intention w a s to carry out pilot-plant and large-scale operation in industrial concerns, considerable time w a s required for the construction of the larger plants. Owing to t h e urgency of the atomic bomb project a n d the vital importance of uranium metal in the program, pilot-plant operation was undertaken at Ames. A gymnasium near the power house w a s taken over and remodeled. The expected production had hardly been met when the quota was tripled and in succeeding months was again and again raised. The plant, initially set up as a pilot plant, was repeatedly enlarged principally b y the process of moving out the walls and tacking on additions to the building. Later a second building was constructed. Finally when the Ames process was i n operation elsewhere, the plants were gradually shut down. In t w o and a half years of operation the Ames plant carried t h e burden of metal production for the experimental developments and the early power piles. T h e very uncollegiate phenomena of armed guards, of freight cars arriving and departing with Army escort, and of Army officers frequenting the buildings, naturally aroused speculation among the faculty and townspeople and the plant acquired the nickname of "Little Ankeny" after a largo ordnance plant south of Ames. S o well was the secret kept, however, that i t was only after the bombing of Hiroshima that any but the scientists on the project knew what was being made.

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PUNCH CARDS IN CORRELATION STUDIES DONALD E. H . FREAR, The Pennsylvania State College, State College, Pa. T H E recent article by Cox, Bailey, and •Casey (1) has called attention to the usefulness of punch cards in chemical bibliography. Experience gained in two years of work in this laboratory has led to the conclusion that punch cards are adaptable to a wide variety of chemical problems, particularly those which deal with large groups of data, such as are encountered i n surveys, correlations, or extended experimental studies. The* particular problem w e had here was a statistical investigation of the correlation between chemical structure and toxicity towards insects and fungi. From a search of the literature and other sources (2), data were collected on approximately 8,000 compounds, on each of which one or more toxicity tests had been made. With such a large number of compounds, and such a wide variety of constituent groups, counting and correlating the data by inspection promised to be a formidable task. T h e first step i n the use of the punch cards was the preparation of a list of all of the constituent groups present in the compounds under study. These were arranged i n order of decreasing complexity, and to each was assigned a number. The chemical formulas for each of the 8,000 compounds were then broken down into constituent groups as they appeared on the master list, and t h e numbers representing these groups recorded for each compound. For example, opposite ethyl alcohol the numbers 581 a n d 1011, designating hydroxyl and ethyl groups, were recorded. T o supply the needed information, it was necessary to prepare as many punch cards for each compound as there were constituent groups in that compound. Thus, for the example already given, t w o cards were prepared, one of which was punched with the number 581, the other with 1011.

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These numbers were punched on the lower margin of the cards, using the 7-4-2-1 "field" arrangement described by Cox et al. On the right margin of the card was punched information on the broad class of compound (insecticide, fungicide, organic, inorganic, etc.), while on the left margin was punched a number representing the relative toxicity of the compound, based on the number of tests, and their results. An index or acquisition number was given each compound and was punched on the top margin of the card. Information of a general nature, including the name and formula of the compound, all constituent numbers, and literature reference numbers were typed on t h e face of each card. After the cards were prepared, the individual constituent groups were separated by sorting. T o return to the example, by sorting for number 581, all compounds having a hydroxyl group in the molecule were collected together. T h e results of the toxicity tests were then totaled, the sum being a numerical designation of the toxicity of compounds containing this particular group. As an extension of this idea, i t is relatively easy t o study the effect of combinations of constituent groups when present in the same molecule. By slight modifications of these basic principles, it is possible to make correlation studies between chemical constitution and any desired property, chemical or physical. With the multiplicity of information accumulated in the literature, it would appear that the punch card will be a most useful tool in chemical research. Literature Cited (1) C o x , G . J.. B a i l e y . C. F., and Casey, R.

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(1945). (2) Frear. I). K. H.. Science, 9 8 , 585 (1943).

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