PHYSIOLOGICAL BOTANY. 197 



far behind the house ; because the house being situated 

 upon the globe, which is in rapid motion, flies away as 

 it were from it ; and lastly why, when a stone falls from 

 a high tower, a deviation ensues, because the summit of 

 the tower is in more rapid motion than the earth at its 

 foot, towards which the stone descends. But I feel 

 ashamed to be teaching matters which belong to ele- 

 mentary school-instruction. Newton correctly ascribed 

 to matter inertia, and not a property of passive resistance, 

 as some philosophers attribute to it ; for so long as the 

 matter is subjected to this law, it has no property ; it is 

 in a perfect state of indifference; it cannot assume a 

 state of motion when at rest ; it cannot, in the slightest 

 degree, alter any motion which has been imparted to it 

 from without, and without its co-operation ; in short, if 

 we may use the expression, it is lifeless. Here, then, we 

 have a certain and definite character of inactivity, from 

 which we may start, and from which we must start, in the 

 consideration of vitality and the vital force. The anti- 

 thesis of vitality, in contrast with this state of inertia, 

 this indifference, is clear ; a body must be called living 

 when capable of spontaneously assuming a state of motion 

 from one of rest, or when capable of changing or in any 

 way determining its motion ; whence what is to be con- 

 sidered as the vital force soon follows. Let us take one 

 application of what we have stated : Is the universal at- 

 tractive force a vital force ? The answer is negative ; the 

 body approximates to another, merely inasmuch as it is 

 attracted ; it does not then set itself in motion ; it does not 

 determine its motion by any power of its own ; this is 

 merely determined by the attraction of some other body. 

 Hence alone is astronomy enabled to calculate with cer- 

 tainty and accuracy the motions of the celestial bodies. 

 This force can certainly set other bodies in motion, but not 

 that body in which it exists, and through which it acts. 

 We cannot in any way understand why there should not 

 be forces capable of setting the bodies in which they exist 

 in motion, since we find motions in living bodies which 



