

CENTUEY OF STUDY OF METEORITES. 197 



be done, many theories regarding the nature and origin of meteorites 

 which have been found untenable as a result of the century's study. 

 The theory of the lunar origin of meteorites had at times such able 

 supporters as Laplace and J. Lawrence Smith. Other able observers 

 have believed meteorites to be material ejected at some past period 

 from the earth's volcanoes, some have regarded them of solar origin, 

 and still others as fragments of a shattered planet. All of these 

 theories may be said to have been proved fallacious. The discovery 

 reported by Hahn in 1880 of remains of sponges, corals, and plants in 

 meteorites excited for a time eager inquiries into the possibilities of 

 proving by the study of meteorites the existence of life outside our 

 own globe. No satisfactory evidence of the existence of extraterres- 

 trial life has, however, as yet been obtained from meteorites. The 

 most positive and enduring results of the century's study may, there- 

 fore, perhaps be summed up as the establishment of the fact of the 

 fall of solid cosmic matter to the earth and a sufficient knowledge of 

 its nature to distinguish it from matter of terrestrial origin. Satis- 

 factory conclusions as to the origin of this matter and its relations to 

 the visible bodies of the great outlying universe remain yet to be 

 drawn. 



