LECTURES AND ESS A YS 



convictions, and to repress equally undue 

 elation, if the half-statement should 

 happen to chime in with our views. It 

 implies a determination to wait calmly 

 for the statement of the whole before we 

 pronounce judgment in the form of either 

 acquiescence or dissent. 



This premised, and I trust accepted, 

 let us enter upon our task. There have 

 been writers who affirmed that the Pyra- 

 mids of Egypt were natural productions; 

 and in his early youth Alexander von 

 Humboldt wrote a learned essay with the 

 express object of refuting this notion. 

 We now regard the pyramids as the work 

 of men's hands, aided probably by 

 machinery of which no record remains. 

 We picture to ourselves the swarming 

 workers toiling at those vast erections, 

 lifting the inert stones, and, guided by 

 the volition, the skill, and possibly at 

 times by the whip of the architect, placing 

 them in their proper positions. The 

 blocks, in this case, were moved and 

 posited by a power external to them- 

 selves, and the final form of the pyramid 

 expressed the thought of its human 

 builder. 



Let us pass from this illustration of 

 constructive power to another of a dif- 

 ferent kind. When a solution of common 

 salt is slowly evaporated, the water which 

 holds the salt in solution disappears, but 

 the salt itself remains behind. At a 

 certain stage of concentration the salt 

 can no longer retain the liquid form ; its 

 particles, or molecules, as they are called, 

 begin to deposit themselves as minute 

 solids so minute, indeed, as to defy all 

 microscopic power. As evaporation con- 

 tinues, solidification goes on, and we 

 finally obtain, through the clustering 

 together of innumerable molecules, a 

 finite crystalline mass of a definite form. 

 What is this form ? It sometimes seems 

 a mimicry of the architecture of Egypt. 

 We have little pyramids built by the salt, 

 terrace above terrace from base to apex, 

 forming a series of steps resembling those 

 up which the traveller in Egypt is dragged 

 by his guides. The human mind is as 

 little disposed to look without question- 



ing at these pyramidal salt-crystals as to 

 look at the pyramids of Egypt, without 

 inquiring whence they came. How, 

 then, are those salt-pyramids built up ? 



Guided by analogy, you may, if ycu 

 like, suppose that, swarming among the 

 constituent molecules of the salt, there is 

 an invisible population, controlled and 

 coerced by some invisible master, placing 

 the atomic blocks in their positions. 

 This, however, is not the scientific idea, 

 nor do I think your good sense will 

 accept it as a likely one. The scientific 

 idea is that the molecules act upon each 

 other without the intervention of slave 

 labour ; that they attract each other, and 

 repel each other, at certain definite 

 points or poles, and in certain definite 

 directions ; and that the pyramidal form 

 is the result of this play of attraction and 

 repulsion. While, then, the blocks of 

 Egypt were laid down by a power external 

 to themselves, these molecular blocks of 

 salt are self-posited, being fixed in their 

 places by the inherent forces with which 

 they act upon each other. 



I take common salt as an illustration, 

 because it is so familiar to us all ; but 

 any other crystalline substance would 

 answer my purpose equally well. Every- 

 where, in fact, throughout inorganic 

 nature, we have this formative power, as 

 Fichte would call it this structural 

 energy ready to come into play, and 

 build the ultimate particles of matter 

 into definite shapes. The ice of our 

 winters and of our polar regions is its 

 handiwork, and so also are the quartz, 

 felspar, and mica of our rocks. Our 

 chalk-beds are for the most part composed 

 of minute shells, which are also the pro- 

 duct of structural energy; but behind 

 the shell, as a whole, lies a more remote 

 and subtle formative 'act. These shells 

 are built up of little crystals of calc-spar, 

 and, to form these crystals, the structural 

 force had to deal with the intangible 

 molecules of carbonate of line. This 

 tendency on the part of matter to organise 

 itself, to grow into shape, to assume defi- 

 nite forms in obedience to the definite 

 action of force, is, as I have said, all- 



