432 



SCIENCE. 



[X. S. Vol. XVIII. No. 457. 



SOIL SURVEY. 



The soil survey was also in advance of 

 anything previously attempted in the 

 Bahamas. The men who conducted the 

 soil investigations were experts in their 

 particular subject and have succeeded in 

 collecting a vast amount of information for 

 future study and investigation. In all six 

 of the more important islands of the archi- 

 pelago were mapped in detail in such a 

 manner as to show distribution of the prin- 

 cipal soil tjrpes. These will be reproduced 

 in color in the report. A large number of 

 chemical analyses were made in a tem- 

 porary laboratory erected in Nassau, in or- 

 der to determine those properties of the 

 soils which are apt to be lost if the samples 

 are allowed to stand for any length of -time. 

 In addition to these preliminary investiga- 

 tions, more elaborate ones will be conducted 

 later, in order to determine other prop- 

 erties of the soils essential to successful 

 agriculture. It is too early at the present 

 time to discuss the results of the soil sur- 

 vey at length, but I feel at liberty to say 

 that when investigations are carried to 

 their conclusion most valuable information 

 will be at hand to direct the farmers of the 

 Bahamas along intelligent lines of agricul- 

 ture. 



HISTORICAL INVESTIGATION. 



The work of examining the public rec- 

 ords and writing the history of the Bahama 

 Islands has been going steadily forward all 

 summer. The historian did not cruise among 

 the out islands with the rest of the mem- 

 bers of the expedition, but remained at 

 work at Government House, Nassau, where 

 the official records were kindly placed at 

 his disposal by the governor. His paper, 

 when completed, will treat of the develop- 

 ment of the Bahama Islands as a crown 

 colony of Great Britain. 



COMMERCL\^L GEOGRAPHY. 



Material has been collected for a chapter 

 on the commercial geography of the islands. 

 This will discuss not only the products of 

 the islands, but also the exports and im- 

 ports, means of communication, condition 

 of the people, etc. 



These results and many others which can 

 not be mentioned in this brief notice will 

 be duly set forth in a report which is now 

 being prepared. 



Geo. B. Shattuck, 

 Director Bahama Expedition. 



SCIENTIFIC BOOKS. 

 The Theory of Optics. By Paul Drude. 



Translated from the German by C. E. 



Mann and E. A. Millikan. New York, 



Longmans, Green & Co. 1902. Pp. xxi + 



546. 



During the past thirty years the science of 

 optics has developed with surprising rapidity; 

 in fact, in few of the branches of science have 

 greater and more far-reaching changes in the 

 fundamental concepts been made. This 

 rapidity of growth may be attributed in large 

 measure to the inspiration derived from the 

 fertile hypothesis that was first suggested by 

 Paraday and afterwards worked out in detail 

 by Maxwell; for it was this hypothesis that 

 called the attention of physicists to the pos- 

 sibility of unifying the sciences of optics and 

 electricity under a single theory and of thus 

 treating them both as manifestations of the 

 phenomena of a common medium, the ether. 

 The experimental work that was undertaken 

 for the purpose of testing this Paraday-Max- 

 well hypothesis has led to extensions and modi- 

 fications of the original supposition until it 

 has now developed into an extensive and well- 

 established theory, namely, the electromag-netic 

 theory of light. 



To the student of modern physics some com- 

 prehension of this fascinating theory is in- 

 dispensable; yet such comprehension has been 

 difficult to obtain because the various frag- 

 ments of the argument by which the theory 

 has been built up have been scattered in the 



