THE CHEMICAL WORLD THIS WEEK produces remarkably sound results. H e has tested it on a large number of inorganic compounds and metal hydrides and found that it gives results that agree with accepted experimental data. H e is currently working on larger and more complex molecules. T h e technique has not yet b e e n developed to handle resonant structures, he reported, although preliminary studies are encouraging. This type of calculation eliminates many of the factors usually considered in calculating molecular structure, the most prominent of which is the nature of the binding force. Kimball considers only the balance of electrostatic forces between the particles in the structure. He claimed that such a simple procedure will make it practical to calculate the structures of many molecules without the expenditure of an unreasonable length of time. Present methods are adequate for the calculation of almost any structure, he said, but the time required in many cases is prohibitive. Structure of Proteins. Protein molecules are one class where the calculation of structural characteristics has not been fully successful, D . Harker of Polytechnic Institute of Brooklyn told the meeting in
Leonard Greenburg ( l e f t ) , director of the division of industrial h y g i e n e a n d safety standards, N e w York State Department of Labor, accepts the Cummings Award from Anna M. Baetjer, Johns Hopkins school of hygiene and public health, president of A I H A C&EN REPORTS: Americon Industrial Hygiene Association
N e w Insecticides No More Harmful than Older Ones Public Health scientist says w e should l e a r n to live safely with organic insecticides
D . Harker, Brooklyn Poly, predicts that n e w techniques should result in determination of one or more protein molecules another presentation. He expressed the belief that the key to these structures will be ultimately discovered by careful analysis of experimental results rather than by t h e construction of theoretical "models." However, he predicted that n e w experimental techniques now being applied to the problem should result in t h e "rather complete determination of one or more protein molecules." Other review papers were presented by R. C. Lord of MIT on the use of vibrational spectra for the study of molecular structure, L . P. Hammett of Columbia on t h e effects of submolecular groups on reactivity, C. P. Walling of Lever Bros, on t h e effects of structure on the reactivity of free radicals, and Britten Chance of the University of Pennsylvania on the structural basis for enzyme action.
1984
C I N C I N N A T I . - T h e r e is no need to fear illness from limited exposure to modern insect poisons, declared William F. Durham of the U. S. Public Health Service Communicable Disease Center, Savannah, Ga., before the American Industrial Hygiene Association, meeting here from April 19 to 25. Dr. Durham said the newer insecticides have not proved any more toxic than nicotine under practical conditions and have a good safety record w h e n c o m pared with older poisons still in use. H o w ever, h e warned, the fact that modern insecticides contribute t o only a small portion of accidental deaths, should not cause us to have a complacent attitude. H e pointed out that with the exception of rare cases of dermatitis and other forms of sensitization, there is evidence that human poisoning b y modern pesticides always involves extensive exposure. H e said there is n o scientific evidence at present to support the v i e w of some clinicians that a w i d e variety of illnesses resembling common respiratory and gastrointestinal disturbances or even psychoneurosis are caused by insignificant exposure to insect poisons. However, chemical tests for the chlorinated hydrocarbon compounds, particularly w h e n made on stomach contents, can give useful information for diagnosis, thinks Dr. Durham.
CHEMICAL
Considering that insects cause a n annual loss o f $4 billion in t h e XJ. S. alone, Dr. Durham stated, a n d that $ 5 4 are saved for every dollar spent o n insecticides, w e w o u l d do well t o learn t o live with them safely. Organic Phosphorus-Containing Insecticides. Accidental poisoning of workers b y organic p h o s p h a t e s c a n b e prevented b y precautionary measures such as adequate ventilation d u r i n g manufacture, wearing of protective clothing, and periodic blood cholinesterase measurements, according to studies of Kenneth P. DuBois and Julius M. C o o n o f t h e University of Chicago. Studying tetraethyl phosphate, hexaethyl p h o s p h a t e , and octamethyl pyrophosphoramide, these workers found that the toxic effects of these compounds are typical of those produced b y cholinergic drugs. T E P P , H E T P , and parathion, he said, p r o d u c e d excessive stimulation of the parasympathetic nervous system, the somatic motor nerves, and the central .nervous system. O M P A differs from the alkyl phosphates in that it is converted to an antichlorinesterase agent b y the liver of mammals a n d d o e s not inhibit brain cholinesterase in v i v o . Effects of Parathion. Cholinesterase studies of men who w e r e spraying apple trees in Quebec with parathion w e r e re-
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Over 1,000 aluminum tank cars have been buiit since G. A. T. X. 8 0 0 0 went into service 2 3 years ago. And every one of t h e m is still on t h e j o b , leaving a record which clearly demonstrates aluminum's advantages for h a n d l i n g many liquid ladings. Built by General American Transportation Corp., G. A. T. X. 8 0 0 0 first hauled glacial acetic acid, was later shifted to fatty acid service. Over the miles and the years, proof accumulated. Proof that the aluminum tank would not contaminate its cargo. Proof that aluminum resists corrosion. Proof that aluminum lasts. N o w tank cars of Alcoa Aluminum help many shippers protect valuable ladings, keep tank maintenance costs down. T h e i r record will help you plan for future equipment to improve rail service at lower cost. A L U M I N U M COMPANY OF AMERICA 1817E Gulf Building
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Pittsburgh 19, P e n n s y l v a n i a
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OLUME
3 0,
NO.
19
» MAY
12,
1952
1985
THE CHEMICAL WORLD THIS WEEK
Pictured at the annual meeting of The Chemical Society, h e l d jointly with the Royal Institute of Chemistry: Left. H. W. Cremer, president of the RIC and Sir Eric Rideal (right), of King's College, London, w h o is retiring president of The Chemical Society. Below. V. C - Barry (left), Trinity College, Dublin, whose talk on studies in the chemotherapy of tuberculosis was one of the three main addresses of the meeting, chats with Lord Moyne, Arthur Guiness, Son & C o . , and C. K. Ingoid, University College, London, new president of t h e society
Ingold Elected President O f Chemical Society D U B L I N . - T h e election of C. K. Ingold, University College, London, to the presidency of the Chemical Society for the next two years, was announced as the Chemical Society and the Royal Institute of Chemistry held their annual meetings jointly in Dublin, April 15 to 18. The joint meeting of these two societies was the first of its kind and was additionally unusual in that the meeting was
ported by Kingsley Kay and others. Checking eholinesterase blood levels in 'the sprayers against those of a control group, they found significantly lower levels of eholinesterase in 25% of the workers during the spraying period. Of the 3 4 sprayers, 17 reported no ill effects and the other 17, having a slightly lower average level of eholinesterase as a group, reported signs such as headaches and nausea on one or more occasions. A few were confined to bed with mild nonspecific illnesses for a few days. Chemical Toxicity Registry. A machine for correlating chemical structure and mammalian toxicity data was discussed at the meeting b y W. J. Wiswesser of Willson Products, Inc. The automatic tabulating equipment employs IBM punched cards. T h e chemical structure notation used is t h e one developed by Dr. Wiswesser (C&EN, Feb. 4, page 4 0 7 ) and the toxicity coding method is based on the value-grading system popularized by H. F. Smyth, Jr., and associates at Mellon Institute. Chemical structure descriptions are concise and will permit each card to carry 20 to 4 0 different toxicity ratings. Cummings Award. Winner of the 1952 Cummings Award of the association was Leonard Greenburg, director of the division of industrial hygiene of the N e w York State Department of Labor. Dr. Greenburg was selected for the award because of his "great work on the medical, engineering, and administrative aspects of industrial hygiene/'
held in Dublin, where die Chemical Society has a number of members and the RIC has a sister organization, the Institute of Chemistry of Ireland, as well as members. Sir Eric Rideal, retiring president of
the Chemical Society, delivered the presidential address, "Colloid Science—A Chapter in Chemistry." H. W. Cremer, w h o continues as president of the R I C , in his presidential address, spoke on "Worthy Ends and Expectations."
INDUSTRY
Construction Field Employment Approaching Postwar High Field employment on industrial construction projects has increased steadily since the start of hostilities in Korea and is now approaching the post-war high set in May 1948, according to the National Constructors Association, an organization composed of builders of chemical plants, steel mills, and petroleum refineries. The figures disclosed by the National Constructors Association are based on direct field employment by its 17 members, which have construction and engineering underway on more than $1 billion worth of projects. Men employed on projects by subcontractors are not included. The chemical contractors are M. W. Kellogg, Lummus Co., H. K. Ferguson, and Stone and Webster. The association's continuing survey on field employment discloses that approximately 47,000 were employed by the 17 companies during the month of March 1952. Indications are that the post-war high of 52,612, set in May 194S, will be surpassed in the May or June figures. The low point among members was April 1950, when 21,321 were employed. In June 1950, employment was 22,869.
CHEMICAL
A significant aspect of the trend in employment was noted during the past winter months from October to February, a period in which construction employment is usually on a decline. Instead o f diminishing, employment increased from 37,741 in October to 40,719 in February. The heaviest concentration of employees engaged in industrial construction was reported in Texas in connection with petroleum refinery and chemical plant expansions. Louisiana has shown a considerable increase. The mid-western states of Illinois, Indiana, and Ohio show heavy gains: Alabama, California, and Pennsylvania are also heavy industrial construction areas.
Shell Chemical Buys Julius Hyman Shell Chemical Corp. has completed arrangements to purchase the stock of Julius Hyman & Co. of Denver, Cola., and has concluded an agreement with t h e Velsicol Corp. of Chicago for exclusive rights world-wide, to aldrin and dieldrin. Shell Chemical has marketed aldrin and dieldrin ever since their commercial in-
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