been put into its present shape. The theory of which I have to 

 speak, known as the nebular hypothesis, is one of the conceptions 

 of Laplace. It was remarked by Laplace that every planet 

 revolves in the same direction round the sun ; and they all turn on 

 their axes in the same direction. It was difficult to deny that there 

 must be some general cause for this, and it naturally occurred to 

 Laplace that if we could find something which was contracting its 

 dimensions, and which had a litde rotation to begin with, then, 

 with every contraction of dimensions, that little rotation would 

 become more and more rapid, till it might acquire any degree of 

 rapidity depending on the condensation of the parts not condensed 

 before. We look out into the world. Can we find anything in 

 such a state that it is probably being condensed, and, having some 

 trifling rotation, will come at last to a rotation that will whirl parts 

 off and form a system of planets and satellites ? There is a system 

 of bodies in the skies which did not attract much attention in 

 former days, mainly because telescopes were not large enough; 

 but they are attracting attention novv-a-days, and are being cata- 

 logued by thousands. They are nebulse. When you examine the 

 sky, small clouds of white matter are to be found. These are 

 small bodies in the skies among the stars. Sometimes they have 

 stars apparently among them. Sometimes they seem to be 

 connected with stars, and sometimes not. They have the 

 strangest and most capricious shapes imaginable. One of the 

 great nebulae is in Orion. That (pointing to a drawing of the 

 nebula) is a very strange piece of matter to form a solar 

 system from, yet there is no doubt, mathematically speaking, that 

 it is competent to that purpose ; — that if this nebula is attracting 

 its particles together, so as to come to a more condensed 

 state, and if it has a very slight rotation to begin with, that 

 rotation in the course of condensation will become so rapid, that it 

 may form sun and^earth and planets round it; and there is no 

 difficulty whatever, on contemplating the matter in this supposition, 

 of making a complete solar system out of such amess^ as that is. 

 I think that is the most conspicuous to all our telescopes, and also 

 perhaps one of the most confused and complicated. There are 



