182 On the Physiology of Fegetahles. 



proceed evidently all from one cause. What power acts on it? 

 What action remains so long after the death of the tree ? We 

 do not believe in witchcraft, and an actio?) must have a cause. 

 A being dies: all motion ceases after death, except one^ which is 

 involiwlary muscular motion. The wood warps after death, it 

 is full of spiral wire: it is tliis which most evident li; causes its 

 motion^ since, if you take a part of it out, all motion ceases, and 

 that pari taken out moues conlinvolly. If this is the case, it 

 must be ihe. muscle of the plant: and the warping is at once ac- 

 counted for, being the only part of the animal which moves after 

 death : it is also the only ))art of the vegetable which retains its 

 action after the vital power is extinct. We are not to judge 

 a living- being by the latvs of non-existing matter; that matter 

 which is made and joined molecule to molecule, may increase 

 by heat, which divides these parts by separating them at a 

 greater or smaller distance. Thus iron is increased by the 

 quantity of caloric introduced between each molecule. But how 

 can this law be carried into a living body ? Vitality is actuated 

 by a totally different power, and partakes completely of the 

 animal in this respect, increasing in continuity; and forced to 

 action by the power of tlie muscles only, after vitality should be 

 dissolved. 



I think I have so exactly marked the difference (with the help of 

 Mirbel's ingenious idea) between the animal, vegetable, and mi- 

 neral, that they can no longer be considered as flowing into each 

 other, or making a series of steps, hut perfectly disjointed, and 

 different from each other, and peculiar in all tlieir parts. The 

 animal having life, brain, nerves, 7nuscles, voluntary and in- 

 voluntary motion. The vegetable life, but neither b>ain nor 

 nerves, but irritability of muscle even superior to animal life*, 

 these serving instead of nerves. Hence in death the vegetable 

 cannot be considered as a being to be contracted or dilated, as 

 iron or ivater, and which is removed by heat molecule from 

 molecule', but as a living creature, which has muscles to move, 

 and which, when dead, can only be subservient to tiie action of 

 the muscles for a time, and which are, like all vegetable muscles, 

 set in motion by the powerful cliange of light and moif'ture, but 

 subject to no other contracting or dilating power. And if in 

 such full proof we want an additional one, to show that the spiral 



* This irritahle or contractile power, is that property by whicli mus- 

 cles recede from stimuli ; it is ii)dopeiidciu of tlie nerves, iind so little 

 connected with fetlins:, that upon cuttini; away all the nerves and stimulat- 

 ing the nmscle with a sliarp-jjointed instrument, or a caustic, or directinj; 

 the electric spark l/avui^/t it, the muscles instantly contract, as docs also tlie 

 veijetable. 



