6 On the MO TlO N of 



fecond day till the jth of March, during which time the tree 

 at both places was always dry. 



MARCH 5. 



FAHRENHEIT'S Thermometer, at noon, in the made, 46. j at 

 midnight, 38. 



ON this day, which had been preceded by the three warmefl 

 days fince the ift of February, when an incifion was made in 

 the trunk of the birch, juft by the ground, I now found a 

 moifture in the wood, not to be perceived before, which made 

 my finger fenfibly wet ; but there was no more moifture in the 

 bark than formerly. The extremities of the branches were cut, 

 and found likewife dry. 



NOTE i. THIS day, twenty-one triangular and equilateral inci- 

 fions were cut in the trunk of the tree, on the north fide. 

 The bafe of thefe triangles was an inch long, and the inci- 

 fion itfelf an inch deep, both the bark and wood being taken 

 out. Thefe incifions reached from the ground to the height 

 of twenty feet, and were exactly one foot diftant from each 

 other. 



2. BY incifion, when not otherwife defcribed in thefe experi- 

 ments, is meant a fedlion through the bark into the wood. 



3. WHEN an incifion does not communicate any fenfible moifture 

 to the finger, it is faid to be dry ; and moift, when it makes 

 the finger fenfibly wet. By bleeding is meant fuch a copious 

 flow of the fap as is fufEcient to form a drop or ftream from 

 an incifion. 



4. BY the fap is meant the lymph, the watery or alimental fap 

 of a tree, and not any peculiar, proper, or venal juice ; be- 

 ing the general fluid from which the peculiar milky, gummy, 

 or refinous juices of trees are formed by fecretion, and in a 

 way fimilar to the fecretion of the different animal fluids from 

 the general mafs of blood. 



MARCH 



