Semi-Centennial Volume. 57 



limestones, to be found if one dug enough for them. Economic geology 

 has taught us where to look for such things and where the search is 

 vain. A better interpretation of ore deposits, and the relations of ore 

 formation to igneous rocks has enriched the world's resources and saved 

 many, many millions of dollars in wasted efforts. And Kansas certainly 

 knows that the formulation of structural theories of the occurrence of 

 oil and gas reservoirs has added immensely to the wealth of state and 

 nation. 



The science of chemistry, too, has been reborn in the years, and its 

 application to man's economic needs is greater perhaps in amount than 

 in any other science. In the days when this Academy was very young 

 was established the law that properties of elements are periodic func- 

 tions of their atomic weights, as a foundation for the new chemistry. 

 The science of carbon compounds, of organic compounds, has progressed 

 marvelously, and with it the whole science of dye compounds and the 

 synthesis of drugs, based upon the discovery of the space relations of 

 atoms and the reconstruction of our conceptions as to the structure of 

 matter. The theory of ionization and the whole science of physical 

 chemistry are products of these years. Witness, for instance, the suc- 

 cessful extrication of nitrogen from the air, and its immense possibilities 

 both in war and in peace. And who knows yet what will result from 

 the discovery of radio-activity in both physics and chemistry? Many 

 new compounds have been discovered in these years. 



In none of the sciences does the history of achievement read more 

 like a mythological tale than in the science of physics. Had one, a 

 century ago, predicted them he would straightway have been led to an 

 asylum. In 1869 I well remember that Professor Mudge, in showing 

 his pupils the sparks from a Leyden jar, predicted that before many 

 years electricity would light our streets. And most people thought such 

 a prediction the irresponsible vaporings of a theorist. Let one barken 

 back to the tallow dips of the fifties, the camphene and crude kerosene 

 lamps of the sixties, and compare them with the lights of to-day. How 

 far indeed from the spark of Franklin's kite! 



Maxwell, when this Academy was very young, foreshadowed the 

 wireless telegraph in his magnetic theory of light, verified by Herz in 

 the electromagnetic waves, and applied by Marconi to that greatest 

 wonder of all science, the wireless telegraph. Telephony and phonog- 

 raphy, discoveries of the early seventies, are now such common and 

 necessary adjuncts of civilization that one wonders how crude things 

 were when they were unknown. And last, but far from least, Darius 

 Green and his flying machine as an established fact may be the final 

 decision in the world's greatest, and we confidently hope victorious war 

 against barbarism. It was a physicist, Langley, who invented it, and 

 physics taught him how. And I have not forgotten the discovery of 

 X-rays and what it means in physics and chemistry. 



Stop for a moment and consider what these discoveries and their 

 application in physics mean to us to-day; to converse in living tones 

 through thousands of miles; to imprison our voice to be released at will 

 perhaps a thousand years hence — think what it would mean could the 



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