TRANSACTIONS OF THE SECTIONS, 3 
lution to suppress indignation if the statement of the one half should clash with our 
convictions, and not to suffer ourselyes to be unduly elated if the half-statement 
should chime in with our views. It implies a determination to wait calmly for the 
statement of the whole, before we pronounce judgment either in theform of ac- 
quiescence or dissent. 
This premised, let us enter upon our task. There have been writers who affirmed 
‘that the pyramids of Egypt were the productions of nature ; and in his early youth 
Alexander von Humboldt wrote an 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 
yolition, the skill, and possibly at times by the whip of the architect, placing the 
stones in their proper positions. The blocks in this case were moved by a power 
external to themselves, and the final form of the pyramid expressed the thought of 
its human builder. 
Let us pass from this illustration of building power to another of a different 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. Ata certain stage of 
concentration the Salt can no longer retain the liquid form ; its particles, or mole- 
cules, as they are called, begin to deposit themselves as minute solids, so minute, 
indeed, as to defy all microscopic power. As evaporation continues solidification 
goes on, and we finally obtain, through the clustering together of innumerable 
molecules, a finite mass of salt of a definite form. What is this form? It some- 
times seems a mimicry of the architecture of Egypt. We have little pyramids 
built by the salt, terrace above terrace from base to apex, forming thus a series of 
steps resembling those up which the Egyptian traveller is dragged by his guides, 
The human mind is as little disposed to look at these pyramidal salt-crystals with- 
out further question, 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 suppose that, swarming among the constituent 
molecules of the salt, there is an invisible population, guided and coerced hy some 
inyisible master, and 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 in- 
teryention of slave labour; that they attract each other and repel each other at cer- 
tain definite points, 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 forces with which they act 
upon each other. 
- I take common salt as an illustration because it is so familiar to us all; but al- 
most any other substance would answer my purpose equally well. In fact, through- 
out 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. It is present everywhere. The ice of our wintersand 
of our polar regions is its handywork, and so equally 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 product of structural energy ; but behind the shell, as a whole, 
lies the result of another and more subtle formative act. These shells are built up 
of little crystals of calc-spar, and to form these the structural force had to deal with 
the intangible molecules of carbonate of lime. This tendency on the part of 
matter to organize itself, to grow into shape, to assume definite forms in obe- 
dience to the definite action of force, is, as I have said, all-pervading. It is in 
the ground on which you tread, in the water you drink, in the air you breathe. 
Incipient life, in fact, manifests itself throughout the whole of what we call inor- 
ganic nature. 
The forms of minerals resulting from this play of forces are various. and exhibit 
different degrees of complexity. Men of science avail themselves of all possible 
means of exploring this molecular architecture. For this purpose they employ in 
tum as agents of exploration, light, heat, magnetism, electricity, and sound. 
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