In a paper on tree surgery read at the nineteenth annual meeting 

 of the Vermont Maple Sugar Makers' Association Mr. C. O. Ormsbee 

 described the physiological process of sap elaboration. He said: 



" Moisture in the soil dissolves and holds in solution certain min- 

 eral elements. This moisture so charged finds its way into the roots 

 of the trees and then into the wood in which it ascends to the leaves 

 through which it passes and from which a very large portion is evapor- 

 ated, or transpired according to the term employed. It is estimated 

 that a very large tree bearing a big top transpires one hundred and 

 fifty tons of water in a season. From the time the moisture enters 

 the roots until it passes through the leaves it is termed crude sap. 

 But air charged with carbonic acid gas, also passes through the leaves, 

 and meeting with the crude sap yields to it the carbonic acid and 

 emerges as pure air, while the crude sap with its load of carbon becomes 



Fig. 12. A SPRING SCENE IN THE MAPI.E COUNTRY 



transformed into what is known as elaborated sap. In this form 

 it finds its way back into the body of the tree where it is conveyed 

 in the wood, here and there wherever needed into the inner layer 

 of the bark which is called the cambium and where it is transformed 



