THE HAMILTON ASSOCIATION. 69 



the possible influence of meteoric matter on the animal life of the 

 earth. Professor Herschel hae succeeded in examining and analyz- 

 ing by means of the spectroscope, the light of seventeen of these 

 bodies, and he has succeeded in detecting the well-known yellow 

 bands produced by sodium in combustion. "It is strange," says 

 the ' Lancet,' " to consider what becomes of all the sodium thus dis- 

 persed throughout the upper regions of the air, as there can be no 

 doubt that in some form or other it reaches the earth. The very 

 air we breathe must at all times contain, in however minute propor- 

 tion, the cosmical dust thus brought to us from the interplanetary 

 spaces, and as the different meteoric systems are differently cons-ti- 

 tuted, the air we breathe is constantly being impregnated with vari- 

 ous forms of metallic dust. It is not certain that deleterious results 

 do not occasionally flow from an excess of some of tBe elements 

 contained in meteors. Professor Roscoe goes so far as to conjec- 

 ture that the soda, which all accustomed to work with the spectro- 

 scope find present everywhere, may by its antiseptic properties, 

 exert a considerable influence in maintaining the public health." 

 Speculations and hypotheses of this kind are no doubt interesting, 

 but, it seems to me, barren of utility till proved, and I merely quote 

 from the ' Lancet ' to show that the study of meteors is attracting 

 other attention than that of astronomers. 



Atmospheric electricity is now also being attributed to meteoric 

 influence, and Professor Govi, in 1878, leans to the idea that a cer- 

 tain amount of heat is introduced into our atmosphere by the me- 

 teors that enter it, and Professor Everett attributes the sudden varia- 

 tions of the needle of the electrometer from no apparent assignable 

 external cause, to the same influence. He adds, our great want at 

 present is balloon observations, and says that he " feels convinced 

 that friction of the air or of the solid particles contained in it is one 

 cause of the generation of electricity in the air," 



Scientific theories necessarily lack finality. Sufficient to-day to 

 explain all the known facts, to-morrow discoveries may show their 

 inadequacy, and lead to their modification or abandonment. 



I will now devote a few minutes to meteorites and the histori- 

 cal records of some of the more celebrated that have fallen from 

 time to time, on the earth. 



Amongst all people, and in almost all ages, a general tradition 

 has prevailed of the fall of solid bodies from the sky, under various 



