94 PECULIAR JUICES. 



The third species of vegetable milk resembles that of 

 the cow, and is the produce of a tree in America, thence 

 called the cow-tree. Mr. Humboldt informs us, that it 

 grows in rocky and unfruitful districts, little calculated for 

 the pasturage of cattle. On the barren side of a rock it 

 rises with coriaceous and dry leaves, which are, during 

 many months of the year, not moistened by a single show- 

 er. The branches appear dead and dry ; but, when the 

 trunk is pierced, there flows from it a sweet and nourish- 

 ing milk. At sunrise, this vegetable fountain is most 

 abundant. The natives are seen hastening from all quar- 

 ters, furnished with large bowls to receive the milk, which 

 grows yellow, and thickens at the surface. This tree is 

 of the family of the Sapoteae. 



Caroline. What a delightful resource it must be to the 

 people of that country, who may repose beneath its shade, 

 while they refresh themselves with the grateful beverage 

 it produces ! Does it also yield fruit ? 



Mrs. B. Every tree yields fruit of some kind, other- 

 wise it could not continue its species ; but that of the 

 cow-tree is as yet unknown. 



Resins are volatile oils, peculiarly modified by the action 

 of oxygen. Pitch, tar, and turpentine are the most com- 

 mon and the most useful juices of this description ; they 

 exude from the pine and fir trees, and are of a thick vis- 

 cous consistence. Copal, mastic, and frankincense are 

 resins of a more refined nature : the two former, dissolved 

 in oil, form excellent varnishes ; and frankincense, you 

 know, is the perfume burnt in all the Catholic churches. 

 The resinous juices flow always in a descending direc- 

 tion : when an incision is made in a tree which yields 

 them, they trickle from the upper edge of the wound. 



Gum is a mucilaginous secretion, common to all legu- 

 minous plants, and to a great number of trees bearing 

 stone-fruits, such as the cherry, the peach, and the apri- 

 cot : whenever an accidental fissure is made in the stem, 

 it exudes from it. 



515. What is the third kind of vegetable milk! 516. What de- 

 scription is given of the cow-tree! 517. What is necessary that 

 trees continue their species'? 518. What are resins'? 519. What 

 are the most common ones! 520. What is said of copal, mastic, and 

 frankincense! 521. -In what direction do resinous juices flow 1 522 

 What is ea id of gum? 



