January 31, 1902.] 



SCIENCE. 



175 



opening' pathways where obstacles now 

 exist. Furthermore, the desirable cooper- 

 ation between investigators would become a 

 much simpler matter to arrange than it is 

 now. Every laboratory for research would 

 become a nucleus around which individual 

 enterprises might cluster, each giving and 

 receiving help. A great work, wisely 

 planned, always attracts eolaborers; its 

 mere suggestiveness is enough to provoke 

 widespread intellectual activity. Here 

 there is no monopoly, no limit to competi- 

 tion, no harmful rivalry ; every research is 

 the seed of other researches, and every ad- 

 vance made by one scholar implies the ad- 

 vance of aU. In the realm of thought we 

 gain by giving; and the more lavish our 

 offerings, the richer we become. 



We glory in the achievements of chem- 

 istry, and we find merit also in its imper- 

 fections, for they give us something more 

 to do. Never can the work be finished, 

 never can all its possibilities be known. 

 Hitherto the science has grown slowly and 

 irregularly, testing its strength from step 

 to step, and securing a sure foothold in the 

 world. Now comes the time for better 

 things; for system, for organization, for 

 transforming the art of investigation itself 

 into something like a science. The endow- 

 ment of research is near at hand, and the 

 results of it will exceed our most sanguine 

 anticipations. 



F. W. Clarke. 



U. S. Geological Survey. 



GRADED CONDENSATION IN BENZINE VA- 

 POR, AS EVIDENCED BY THE DISTORTED 

 CORONAS AND MARKED AXIAL 

 COLOR EFFECTS ATTENDING 

 CLOUDY CONDENSATION. 



1. It would be difficult to read the ad- 

 mirable work on the relation of rain and 

 atmospheric electricity which has issued 

 from the Cavendish Laboratory, without 

 being convinced of the strength of the argu- 

 ments put forth. That in a repetition of 



these researches, in particular of the ex- 

 periments of C. T. R. Wilson* on the com- 

 parative efficiency as condensation nuclei 

 of positively and negatively charged ions, 

 one would but reproduce his results ad- 

 mits of no doubt. 



In so important a question, however, it 

 is none the less desirable to reach identical 

 conclusions from entirely different methods 

 of approach. It has been part of my pur- 

 pose to be driven to like inferences ; in 

 other words, to reach a point in my work 

 where I should have to abandon the nucleus 

 as an agency which for purely mechanical 

 or thermodynamic reasons facilitates con- 

 densation, and be compelled to recognize 

 the special activity due to its charge. 



I had hoped to accomplish this in the 

 following experiments with benzine when 

 contrasted with the corresponding be- 

 havior of water; but the results, contrary 

 to my expectation, are so curious and pro- 

 no\inced an accentuation of the nuclear 

 theory that it seems worth wliile to spe- 

 cially describe them. 



2. The work originated in the following 

 point of view : if the action promoting con- 

 densation is in any degree of a chemical 

 nature (such suppositions have been made; 

 the production of hydrogen superoxide, for 

 instance, has been suggested), then there 

 should be a marked difference in the effi- 

 cacy of the same nucleus Avhen the satu- 

 rated water vapor is replaced by the vapor 

 of some electrolytically neutral liquid, like 

 a hydrocarbon. I accordingly made a 

 series of experiments with benzine, en- 

 deavoring at first to utilize benzine jet 

 and color tube in the usual way. In this I 

 failed for reasons without much relevant 

 interest here. I then adopted the method 

 of adiabatic cooling, partially exhausting a 

 spherical receiver (Coulier, Kiessling) 

 about 23 cm. in diameter, illuminated by 



*C. T. R. Wilson, Phil. Trans., London, Vol. 

 CXCIII., pp. 289-308, 1899. 



