384 FRAGMENTS OF SCIENCE. 



natural laws, and it is the vocation of the man of science to 

 resolve this noise into its components, and thus to detect 

 the " music " in which the foundations of Nature are laid. 



The necessity of this detachment of one force from all 

 other forces is nowhere more strikingly exhibited than in the 

 phenomena of crystallization. Here, for example, is a so- 

 lution of common sulphate of soda or Glauber salt. Look- 

 ing into it mentally, we see the molecules of that liquid, 

 like disciplined squadrons under a governing eye, arranging 

 themselves into battalions, gathering round distinct centres, 

 and forming themselves into solid masses, which after a time 

 assume the visible shape of the crystal now held in my hand. 

 I may, like an ignorant meddler wishing to hasten matters, 

 introduce confusion into this order. This may be done by 

 plunging a glass rod into the vessel ; the consequent action 

 is not the pure expression of the crystalline forces ; the 

 molecules rush together with the confusion of an unorgan- 

 ized mob, and not with the steady accuracy of a disciplined 

 host. In this mass of bismuth also we have an example of 

 confused crystallization ; but in the crucible behind me a 

 slower process is going on : here there is an architect at 

 work " who makes no chips, no din," and who is now build- 

 ing the particles into crystals, similar in shape and structure 

 to those beautiful masses which we see upon the table. By 

 permitting alum to crystallize in this slow way, we obtain 

 these perfect octahedrons ; by allowing carbonate of lime 

 to crystalize, Nature produces these beautiful rhomboids ; 

 when silica crystallizes, we have formed these hexagonal 

 prisms capped at the ends by pyramids ; by allowing salt- 

 petre to crystallize we have these prismatic masses, and 

 when carbon crystallizes, we have the diamond. If we wish 

 to obtain a perfect crystal, we must allow the molecular 

 forces free play : if the crystallizing mass be permitted to 

 rest upon a surface it will be flattened, and to prevent this 

 a small crystal must be so suspended as to be surrounded 



