12 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 3 



of the borderline character of the researches ; it was necessary to 

 provide for physical, chemical, and biological fields of investigation. 

 In spite of the constant construction and equipment problems, actual 

 research work was started, and two experiments, the one on photo- 

 tropism, the other on infra-red absorption of pure chemicals, were 

 carried to interesting preliminary results. 



Offices for the division Avere provided by remodelling the hitherto 

 unused flag tower of the Smithsonian Building, and space in the 

 basement previously used for storage was reconstructed into a mod- 

 ern ph3'sical, chemical, and biological laboratory. A small group of 

 highly trained specialists has been assembled to carry on the inves- 

 tigations, and these men work in close cooperation with the Smith- 

 sonian Astrophysical Observatory, the Fixed Nitrogen Laboratory of 

 the Agricultural Department, the "University of Maryland, and the 

 Research Corporation of New York. 



The chief aim of the division is to build up a strong spectro- 

 jihotometric laboratory, whose staff of physicists and technicians 

 will work in cooperation with men of biological training. The re- 

 searches to be undertaken fall into two classes: (1) Direct investiga- 

 tion ujDon living organisms, and (2) fundamental molecular struc- 

 ture and photochemical investigations related to the biological 

 problems. In connection with the first, an experiment was made 

 to determine the amount of bending of plants towards light of var- 

 ious wave lengths. Briefly, the experiment showed that red or infra- 

 red light produced no effect ; that yellow light produced a small but 

 measurable bending; that green light was 1,000 times more effective 

 than yellow; and that blue light was 30 times more effective than 

 green, or 30,000 times more effective than yellow. These results are 

 so interesting that preparations are under way for a more elaborate 

 experiment. 



Under the second heading above, no work could be undertaken 

 at the Smithsonian because of lack of funds and shop equipment. 

 Some progress Avas made, hoAvever, in the preparation of equipment, 

 and through the cooperation of the Fixed Nitrogen Laboratory, Mr. 

 Liddell of its staff continued an investigation begun there by Doctor 

 Brackett before his appointment by the Smithsonian. This project, 

 which was completed as far as the equipment permitted, involved 

 the study of the near infra-red absorption spectra of the halogen 

 deviations of benzene. 



EXPLORATIONS AND FIELD WORK 



Expeditions in the field are essential to the Smithsonian's work 

 in anthropology, biology, geology, and astrophysics. Twenty-eight 

 major expeditions went out during the year to widely scattered 

 regions, bringing back necessary information and valuable speci- 



