310 MR. THOMAS CARRICK ON THE 



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of the progression of the wave of high water_, which compre- 

 hends in harmonious relation a greater range of facts than 

 any hypothesis hitherto propounded. It may therefore 

 not be altogether out of place to illustrate this method of 

 grouping the facts of tidal phenomena by some brief allu- 

 sion to the cosmical speculations which have led to this 

 mode of procedure ; and although we decline to indorse 

 the received '^ nebular hypothesis '^ as a genetic theory^ we 

 shall nevertheless^ for the moment, avail ourselves of the 

 ideas and phraseology of that hypothesis, as offering the 

 simplest mode of setting forth with becoming brevity, in 

 this incidental portion of the subject, the manner in which, 

 in our view, terrestrial conditions of matter and force are 

 related to space and to bodies in space. 



Assuming the existence of a diffused nebula composed of 

 ultimate atoms of matter, each having a normal rotation 

 on a fixed axis in a uniform direction, and with simple 

 forces of attraction and repulsion, arising thereout in virtue 

 of laws analogous to those by which the poles of magnets, 

 under given conditions, alternately attract or repel each 

 other, then any disturbance of the equilibrium of forces in 

 this nebula might lead either to condensation on the one 

 hand or to greater rarefaction on the other. 



Should condensation result, that condensation could 

 hardly be supposed to take the form of a graduated state, 

 passing by insensible degrees from the extreme of solid 

 condensation at the centre, to the extreme of nebulous 

 rarefaction in space. For, taking into account the assumed 

 polarity of the ultimate atoms of matter (an assumption 

 indispensable as a basis for differentiation in any nebu- 

 lar theory from which all existing conditions, relations, 

 and motions of terrestrial matter are to be derived), it is 

 reasonable to assume that the nebulous matter in condens- 

 ing upon a centre, from causes arising out of diverse mole- 

 cular groupings of these atoms and their poles, would take 



