gave considerable study to this applica­tion of odor thresholds in the course of his investigations.

Perhaps one of the most widely used applications of threshold tests is that which determines the palatability of water. B y comparing odor-free water with samples of different stages in a water purification plant, it is possible ~ to keep a check on the change of tastes and odors in raw water; this permits preventive measures and also shows the effects of chlorination, activated car­bon, and ozone. The public has be­come so odor- and taste-conscious thai it will not now accept many things-which it would not have noticed 50 years before. A layman not only dislike > unpalatable water; he believes that un­pleasant taste and odor indicate con­tamination, and therefore he mistrusts it. Consequently, he may turn to other supplies, wells and springs, which are less safe.

A most important use of the knowl­edge of threshold values of various sub­stances is the determination of warning agents to be used in odorless vapors such as natural gas. Very little warning agent is necessary as compared to the amount of material it renders odorous. Needless to say, the quantity should be well above the threshold value.

The Bureau of Mines publication (£) lists approximately 75 odorants rated in air at slightly above the threshold level where the odor is weak but readily per­ceptible.

N o w and again companies whose pro­duction inevitably results in stinks re­ceive complaints from irate neighbors. A knowledge of threshold and thus of the travel limits of the objectionable odors may decide the validity of complaints.

A recent article by King and Jenny (9) cites a problem which occurred dur­ing the development of the manufacture of a rubber accelerator, mercaptobenzo-thiazole. The exhaust air from dryers plagued the surrounding area with a strong, stable, and offensive odor. It was assumed for two reasons that the cause of the trouble was a mercaptan: first, a mercaptan was being produced, and second, mercaptans are a family of chemicals which are nearly all charac­terized by unpleasant odors. However, this assumption was not correct. The engineers working on the problem finally discovered that the offender was benzo-thiazole which was concentrated in the air to the extent of less than a pound per 100,000 cubic feet. Thus, a substance having an extremely low threshold value had been the source of a baffling puzzle.

T h e how and why of odor and its perception are unknown to us, but like other phenomena, the ultimate nature of which we know little, that property of matter which evokes an olfactory stimulus may be pleasing or annoying to us but serves us well in daily living.

Literature Cited

(1) Crocker, E. C , "Flavor," p. 12, New York, McGraw-Hill Book Co., Inc., 1945.

(2) Moncrieff, R. W., "The Chemical Senses," p. 77, New York, John Wiley & Sons, Inc., 1944.

(3) Elsberg, C. A., and Levy, I., Bull. Neurol. Inst. N. Y., 4, No. 1, (1935).

(4) Moncrieff, R. W., "The Chemical Senses," p. 88, New York, John Wiley & Sons, Inc., 1944.

(5) Moncrieff, R. W., Ibid., p. 80. (6) Moncrieff, R. W., Ibid., p. 88.

J. wo new buildings, for chemistry and metallurgical and chemical engineering, were dedicated by Illinois Institute of Technology on June 17. A full day's program featured the dedication, high­lighted by a luncheon address on "In­dustry and Private Educational Insti­tutions" by James A. Rafferty, vice president of the Union Carbide & Carbon Corp.

Constructed in the modern functional ^tyle of Ludwig Mies van der Rohe, the units are a part of IIT's long-range de­velopment program.

Linus Pauling, California Institute of Technology, President of the ACS, spoke before the technical session Friday morning on "New Structural Concepts in Inorganic Chemistry." Other speakers were Cyril Smith, University of Chicago, James B. Austin, United States Steel Corp. of Delaware, and George Granger Brown, University of Michigan.

Mr. Rafferty, in his dedication speech, paid tribute to the American system, which, he said, has been "to create wholly new values from resources previ-

(7) McCord, C. P., and Witheridge, W. N., "Odors, Physiology and Con­trol," p. 29, New York, McGraw-Hill Book Co., Inc., 1949.

(8) Fieldner, A. C , Savers, R. R., Yant, W. P., Katz, S. H., Shohan, J . B., and Leitch, R. D., "Warn­ing Agent for Fuel.Gases," U. S. Dept. of Commerce, Bureau of Mines, 1931.

(9) King, V. L., and Jenny, J. R., Chem. Enyr., 56, No. 3 , 111 (1949).

PRESENTED at the Conference on Air Pollution of the Manufacturing Chemists' Association, New York, N. Y„ April 19-20, 1949.

ously ignored, through the application of science to industry." The success of science applied to industry has occurred largely through the medium of men provided with technical education, he said, and it has been the outstanding event of the past century, if not of all time. Now, he asserted, our country's well-being and comfort, as well as its prosperity, health, and defense against aggression, are dependent upon our tech­nological assets. An ample flow of specialists is needed to maintain this* situation, he contended.

Mr. Rafferty pointed out that edu­cational institutions, particularly those privately endowed, are supported to a considerable extent by industry. At the present time, he noted, there is much talk of activity in many schools which is in opposition t o the American system. Such activity, he stated, is likely to weaken the support of these institutions by advocates of the capitalistic system and the result will be one of harm to our educational system, resulting in a weak­ening of our whole society.

1IT Dedicates New Buildings

V O L U M E 2 7, N O . 2 7 . • » • J U L Y 4, 1 9 4 9 1955