316 M. Becqiierel o« the Relations of Natural Philosophy 



They are the pioneers of civilization ; they enlighten, they guide, 

 and sometimes even arrest, the progress of any one who would 

 take too bold a flight towards those departments in which they 

 preside. We now proceed to exhibit the importance of their 

 simultaneous association, by supplying a rapid exposition of 

 some general facts, which are calculated to elucidate the point. 



All bodies around us are composed of particles which are 

 united by certain forces, whose nature is more or less unknown, 

 according as they are organic or inorganic. The formation of 

 organized bodies is still enveloped in deep obscurity, whilst it is 

 not so, at least to the same extent, with regard to that of inor- 

 ganic bodies, inasmuch as a great number of facts go to prove 

 that their particles are subjected to the action of forces which 

 apparently have an electrical origin. 



The investigations which have been made on this subject by 

 Davy and Berzelius, have given a most extraordinary impulse to 

 the physico-chemical sciences. The philosophers of all coun- 

 tries are eager, and are becoming more and more so, to co-ope- 

 rate in the discovery of a principle, the knowledge of which will 

 be of the highest importance to natural philosophy, as it will 

 enable us to resolve all questions regarding actions at a minute 

 distance, in the way Newton has done relative to planetary at- 

 traction. 



The power in virtue of which heterogeneous particles unite 

 together in inorganic nature, is different, or at least is not pre- 

 cisely of the same kind as that which operates in integrant ato- 

 mic attraction (attraction moleculaire). Natural philosophy, in 

 studying the effects of this latter, makes use of cleavage, elasti- 

 city, and polarized light. Cleavage makes us acquainted with 

 the crystalline system of mineral bodies; the phenomena of 

 elasticity supply us with most valuable data for the discovery of 

 the constitution of bodies in general ; and a pencil of polarized 

 light penetrating, like a probe of infinite delicacy, into a trans- 

 parent body, shews us, by the modifications it undergoes, the 

 crystalline system to which it belongs, and at the same time pre- 

 sents us with the means of determining all its elements. 



Circular polarization enables us to study the constitution of 

 organic compounds, since this property has been discovered in a 

 great'many solid and fluid substances, and it has been noticed that 



