ON RADIANT MATTER. 



157 



principles of myth-making may still be learned from the peasants of 

 Europe. 



When, within the memory of some here present, the science of 

 man was just coming into notice, it seemed as though the study of 

 races, customs, traditions, were a limited though interesting task, 

 which might, after a few years, come so near the end of its materials 

 as no longer to have much new to offer. Its real course has been far 

 otherwise. Twenty years ago it was no difficult task to follow it step 

 by step ; but now even the yearly list of new anthropological litera- 

 ture is enough to form a pamphlet, and each capital of Europe has its 

 anthropological society in full work. So far from any look of finality 

 in anthropological investigations, each new line of argument but opens 

 the way to others behind, while these lines tend as plainly as in the 

 sciences of stricter weight and measure toward the meeting-ground 

 of all sciences in the unity of nature. — Nature. 



ON RADIANT MATTER.* 



By WILLIAM CEOOKES, F. E. S. 



n. 



Eadiant Hatter exerts Strong Mechanical Actioji ichere it strikes. 



WE have seen, from the sharpness of the molecular shadows, that 

 radiant matter is arrested by solid matter placed in its path. 

 If this solid body is easily moved, the impact of the molecules will 

 reveal itself in strong mechanical action, Mr. Gimingham has con- 

 structed for me an ingenious piece of apparatus which, when placed in 



the electric lantern, will render this mechanical action visible to all 

 present. It consists of a highly-exhausted glass tube (Fig. 11), hav- 



* A lecture delivered before the British Association for the Advancement of Science, 

 at Sheffield, Friday, August 22, 1879. 



