REPORT OF THE SECRETARY. 



RESEARCH. 



The Institution has continued research work in various fields of 

 science, including experiments in the solution of the problem of 

 mechanical flight, and, through its Astrophysical Observatory, inves- 

 tigations of the solar spectrum. A fuller account of the latter will be 

 found under the proper head. 



The Institution has made some experiments during the year on 

 "radio-active substances," based on the discovery by Professor Bec- 

 querel in 1896, that uranium salts emit invisible radiations capable of 

 charging electrified bodies and of producing shadow images on sensi- 

 tive plates. 



The Secretary secured from France and Germany specimens of chlo- 

 ride of radium, polonium subnitrate, and other radio-active substances 

 prepared by Monsieur and Madame Curie. These substances were 

 alleged to have the altogether extraordinar}^ property of emitting light, 

 that is, a form of energy, without limit, somewhat like the pretended 

 lamp of the medieval alchemists. A portion of this which was repre- 

 sented as having never been exposed to the sunlight, and which had 

 certainly been several weeks at least in total darkness, was opened by 

 Dr. Bolton in an entirely dark room, and immediately displayed a 

 feeble light which was, nevertheless, strong enough to enable the pho- 

 tographer to secure a very distinct print of a photograph. Other 

 experiments were made by Dr. Bolton, which will be found fully 

 described in the General Appendix of the Smithsonian Report for 1899. 



It is not to be presumed that we have obtained this energy out of 

 nothing, but it remains to be shown what the something is out of which 

 it may have come. This subject has since attracted much interest 

 among chemists in this country as well as abroad. The experiments 

 at the Institution were perhaps the earliest, but not the only ones in 

 this country, and their publication seems to have excited such wide 

 attention as to justify this mention. 



THE HODGKINS FUND. 



The diflferent branches of research now progressing under grants 

 from the Hodgkins fund are making satisfactory advances. 



Prof. William Hallock. of Columbia University, New York, has 

 supplemented his report of last year by a summary of the further 

 progress of his investigation of the motion of an air particle under the 

 influence of articulate speech. The instruments which Professor Hal- 

 lock has invented, and is now perfecting, have proved a great aid in 

 this research, and will, he states, enable him to settle definitely the 

 question of phase difi^erences in the components of a complex sound. 



Prof. A. G. Webster, of Clark University, reports the completion 

 and successful application to the use for which it was designed of the 



