70 SECRETED FLUTDS. 



confined to the bark, but deposited -through* 

 out the substance or wood of the root, as in 

 Rhubarb, Rheum pdlmatum, Linn.jiL Fasci 

 t. 4, and Gentian, Gentiana lutea and pur- 

 purea, Ger. emac. 432,/. 1,2. In the wood 

 of the Fir indeed copious depositions of tur- 

 pentine are made, and in that of every tree 

 more or less of a gummy, resinous or sac- 

 charine matter is found. Such must be 

 formed by branches of those returning ves- 

 sels that deposit the new alburnum. These 

 juices appear to be matured, or brought to 

 greater perfection, in layers of wood or bark 

 that have no longer any principal share in the 

 circulation of the sap. 



The most distinct secretions of vegetables 

 require to be enumerated under several dif- 

 ferent heads. 



Gum or mucilage, a viscid substance of 

 little flavour or smell, soluble in water, is 

 very general. When superabundant it ex- 

 udes from many trees in the form of large 

 drops or lumps, as in Plum, Cherry, and 

 Peach-trees, and different species of Mimosa 

 or Sensitive plants, one of which yields the 

 Gum Arabic, others the Gum Senegal, &c. 



