ON COMETS. 93 



or to carry his bones about the streets on account of 

 any of these later great comets. 



(2.) When we look through nature and observe the 

 manifest indications of design which every point of it ex- 

 hibits, it would be very presumptuous in us to assert that 

 comets are of no use, and serve no purpose in our system. 

 Hitherto, however, no one has been able to assign any 

 single point in which we should be a bit better or worse 

 off, materially speaking, if there were no such thing as 

 a comet. Persons, even thinking persons, have busied 

 themselves with conjectures: such as that they may serve 

 for fuel for the sun (into which, however, they never 

 fall), or that they may cause warm summers which 

 is a mere fancy or that they may give rise to epidemics, 

 or potato-blights, and so forth. But I need hardly say 

 this is all wild talking, as my readers will be better 

 able to judge when I shall have stated a few things which 

 are known for certain about them. But there is a use, 

 and a very important one, of a purely intellectual kind, 

 which they have amply fulfilled ; and who shall say that 

 it has not been designed that such should be the case ? 

 They have afforded some of the sublimest and most 

 satisfactory verifications of our astronomical theories 

 they have furnished us with a proof amounting to 

 demonstration of the existence of a repulsive force* 

 directed (under certain circumstances, and acting on 

 certain forms of matter) from the sun as well as of that 



* See on this subject my "Results of Astronomical Observations 

 at the Cape of Good Hope," p. 407, et sey., where the existence of 

 such a repulsive force is clearly demonstrated. 



