The alburnous saps of some trees have been che- 

 mically examined by Vauquelin. He found in those 

 of the elm, beech, yoke elm, hornbeam and birch, ex- 

 tractive and mucilaginous matter, acetic acid combin- 

 ed with potassa or lime. The solid matter afforded 

 by their evaporation yielded an ammoniacal smell, pro- 

 bably owing to albumen: the sap of the birch afforded 

 saccharine matter. 



Deyeux in the sap of the vine and the yoke elm 

 has detected a matter analogous to the curd of milk. 

 I found a substance similar to albumen in the sap of 

 the walnut tree. 



I found the juice which exudes from the vessels 

 of the marshmallow when cut, to be a solution of 

 mucilage. 



The fluids contained in the sap vessels of wheat 

 and barley, afforded in some experiments which I made 

 on them, mucilage, sugar, and a matter which coag- 

 ulated by heat; which last was most abundant in wheat. 

 The following table contains a statement of the 

 quantity of soluble or nutritive matters contained in 

 varieties of the different substances that have been 

 mentioned, and of some others which are used as arti- 

 cles of food, either for man or cattle. The analyses 

 are my own; and were conducted with a view to a 

 knowledge of the general nature and quantity of the 

 products, and not of their intimate chemical composi- 

 tion. The soluble matters afforded by the grasses, 

 except that from the fiorin in winter, were obtained 

 by Mr. Sinclair, gardener to the duke of Bedford, 

 from given weights of the grasses cut when the seeds 

 were ripe; they were sent to me by his Grace's desire 



