128 FRAGMENTS OF SCIENCE. 



various bodies once formed parts of the same undislo- 

 cated mass ; that matter in a nebulous form preceded 

 matter in its present form ; that as the ages rolled away, 

 heat was wasted, condensation followed, planets were 

 detached ; and that finally the chief portion of the hot 

 cloud reached, by self-compression, the magnitude and 

 density of our sun. The earth itself offers evidence of a 

 fiery origin ; and in our day the hypothesis of Kant and 

 Laplace receives the independent countenance of spec- 

 trum analysis, which proves the same substances to be 

 common to the earth and sun. 



Accepting some such view of the construction of our 

 system as probable, a desire immediately arises to con- 

 nect the present life of our planet with the past. We 

 wish to know something of our remotest ancestry. On 

 its first detachment from the central mass, life, as we 

 understand it, could not have been present on the earth. 

 How, then, did it come there ? The thing to be encou- 

 raged here is a reverent freedom a freedom preceded 

 by the hard discipline which checks licentiousness in 

 speculation while the thing to be repressed, both in 

 science and out of it, is dogmatism. And here I am 

 in the hands of the meeting willing to end, but ready 

 to go on. I have no right to intrude upon you, un- 

 asked, the unformed notions which are floating like 

 clouds, or gathering to more solid consistency, in the 

 modern speculative scientific mind. But if you wish 

 me to speak plainly, honestly, and undisputatiously, I 

 am willing to do so. On the present occasion 



You are ordained to call, and I to come. 



Well, your answer is given, and I obey your call. 



Two or three years ago, in an ancient London 

 College, I listened to a discussion at the end of a lec- 

 ture by a very remarkable man. Three or four hundred 



