MOLECULES. 377 



the kind which metaphysicians call necessary. We may use our knowledge of 

 such truths for purposes of deduction, but we have no data for speculating as 

 to their origin. 



But that there should be exactly so much matter and no more in every 

 molecule of hydrogen is a fact of a very different order. We have here a 

 particular distribution of matter a collocation to use the expression of Dr 

 Chalmers, of things which we have no difficulty in imagining to have been 

 arranged otherwise. 



The form and dimensions of the orbits of the planets, for instance, are not 

 determined by any law of nature, but depend upon a particular collocation of 

 matter. The same is the case with respect to the size of the earth, from 

 which the standard of what is called the metrical system has been derived. 

 But these astronomical and terrestrial magnitudes are far inferior in scientific 

 importance to that most fundamental of all standards which forms the base 

 of the molecular system. Natural causes, as we know, are at work, which 

 tend to modify, if they do not at length destroy, all the arrangements and 

 dimensions of the earth and the whole solar system. But though in the course 

 of ages catastrophes have occurred and may yet occur in the heavens, though 

 ancient systems may be dissolved and new systems evolved out of their ruins, 

 the molecules out of which these systems are built the foundation stones of 

 the material universe remain unbroken and unworn. 



They continue this day as they were created perfect in number and 

 measure and weight, and from the ineffaceable characters impressed on them 

 we may learn that those aspirations after accuracy in measurement, truth in 

 statement, and justice in action, which we reckon among our noblest attributes 

 as men, are ours because they are essential constituents of the image of Him 

 who in the beginning created, not only the heaven and the earth, but the 

 materials of which heaven and earth consist. 



VOL. n. 48 



