110 APPENDIX. 



into them ; these are placed immediately on the 

 outside of the arterial vessels, between the wood 

 and inner bark, and lead down directly to the 

 covering of the root. They perform the office of 

 veins, and contain the liquid sap which is found 

 in plants in the spring and summer months. 



" Fourthly. The bark of a tree is of a spongy 

 texture, and by many little strings which pass 

 between the arterial pipes corresponds with the 

 pith ; and 



" Fifthly. The pith is composed of little trans- 

 parent globes, chained together in like manner 

 with those bubbles which compose the froth of 

 any liquor. In fine, a plant is like an alembic, 

 which distils the juices of the earth ; as, for ex- 

 ample: 



" The root having sucked in the salts of the 

 earth, and thereby filled itself with proper juices 

 for the nourishment of the tree, these juices then 

 are set in motion by heat, that is, they are made 

 to evaporate into steam, as the matter in a still 

 will do when it begins to warm. Now, as soon 



