416 POPULAR LECTURES AND ADDRESSES. 



were far asunder before it was hot, the immediate 

 antecedent to its incandescence must have been 

 either two bodies with details differing only in 

 proportions and densities from the cases we have 

 been now considering as examples ; or it must have 

 been some number more than two some finite 

 number at the most the number of atoms in the 

 sun's present mass, a finite number (which may 

 probably enough be something between 4 x io 57 

 and 140 X io 57 ) as easily understood and imagined 

 as numbers 4 or 140. The immediate antecedent 

 to incandescence may have been the whole con- 

 stituents in the extreme condition of subdivision 

 that is to say, in the condition of separate atoms ; 

 or it may have been any smaller number of groups 

 of atoms making minute crystals or groups of 

 crystals snowflakes of matter, as it were ; or it 

 may have been lumps of matter like a macadamis- 

 ing stone ; or like this stone 1 (Fig. 50), which you 



1 These three meteorites are in the possession of the Hunterian 

 Museum of the University of Glasgow, and the wood-cuts, Figs. 50, 

 51, and 52, have been executed from the actual specimens kindly lent 

 for the purpose by the keeper of the museum, Professor Young. 

 The specimen represented by Fig. 50 is contained in the Hunterian 



