22 cosmos. 



tro-magnetic, and organic processes. Newton* even distin- 

 guished the attraction of masses, as manifested in the mo- 

 tion of cosmical bodies and in the phenomena of the tides, 

 from molecular attraction, which acts at infinitely small 

 distances and in the closest contact. 



Thus we see that among the various attempts which have 

 been made to refer whatever is unstable in the sensuous 

 world to a single fundamental principle, the theory of grav- 

 itation is the most comprehensive and the richest in cosmic- 

 al results. It is indeed true, that notwithstanding the brill- 

 iant progress that has been made in recent times in stcechi- 

 ometry (the art of calculating with chemical elements and 

 in the relations of volume of mixed gases), all the physical 

 theories of matter have not yet been referred to mathematic- 

 ally-determinable principles of explanation. Empirical laws 

 have been recognized, and by means of the extensively- dif- 

 fused views of the atomic or corpuscular philosophy, many 

 points have been rendered more accessible to mathematical 

 investigation ; but, owing to the unbounded heterogeneous- 

 ness of matter and the manifold conditions of aggregation of 

 particles, the proofs of these empirical laws can not as yet ' 

 by any means be developed from the theory of contact-at- 

 traction with that certainty which characterizes the estab- 

 lishment of Kepler's three great empirical laws derived from 

 the theory of the attraction of masses or gravitation. 



At the time, however, that Newton recognized all move- 

 ments of the cosmical bodies to be the results of one and the 

 same force, he did not, like Kant, regard gravitation as an 

 essential property of bodies,t but considered it either as the 



* Adjicere jam licet de spiritu quodam subtilissimo corpora crassa 

 pervadente et in iisdem latente, cujus vi et actionibus particulae corpo- 

 rum ad minimas distantias se mutuo attrahunt et contiguae facta cohe- 

 rent. — Newton, Principia Phil. Nat. (ed. Le Sueur et Jacquier, 1760), 

 Schol. gen., \. iii., p. 676; compare also Newton's Optics (ed. 1718), 

 Query 31, p. 305, 353, 367, 372. (Laplace, Syst. du Monde, p. 384, and 

 Cosmos, vol. i., p. 63 (note).) 



t Hactenus phaenouiena coelorum et maris nostri per vim gravitatis 

 exposui, sed causam gravitatis nondum assignavi. Oritur utique haec 

 vis a causa aliqua, quae penetrat ad usque centra solis et planetarum, 

 sine virtutis diminutione ; quaeque agit non pro quantitate superficierum 

 particularum, in quas agit (ut solent causae mechanicae), sed pro quanti- 

 tate materiae solidae. — Rationem harum gravitatis proprietatum ex pha> 

 nomenis nondum potui deducere et hypotheses non fingo. Satis est 

 quod gravitas revera existat et agat secundum leges a nobis expositas. 

 — Newton, Principia Phil. Nat., p. 676. " To tell us that every spe- 

 cies of things is endowed witlr an occult specific quality, by which it 



