350 OBSERYATIONS O?? VEGETABLES. 



The circumference of trees planted by myself, at one foot 

 from the ground (1790) :— 



The great oak in the Holt, which is deemed by Mr.Marsham 

 to be the biggest in this island, at 7 feet from the ground, 

 measures, in circumference, 34 feet. It has, in old times, 

 lost several of its boughs, and is tending to decay. Mr. 

 Marsham computes that, at 14 feet length, this oak contains 

 1000 feet of timber. 



It has been the received opinion that trees grow in height 

 only by their annual upper shoot. But my neighbour over 

 the way, whose occupation confines him to one spot, assures 

 me that trees are expanded and raised in the lower parts 

 also. The reason that he gives is this : the point of one of 

 my firs began, for the first time, to peer over an opposite 

 roof at the beginning of summer ; but, before the growing 

 season was over, the whole shoot of the year, and three or 

 four joints of the body beside, became visible to him as he 

 sits on his form in his shop. According to this supposition, 

 a tree may advance in height considerably, though the 

 summer shoot should be destroyed every year. AVhite. 



Flowing of Sap. — If the bough of a vine is cut late in 

 the spring, just before the shoots push out, it will bleed con- 

 siderably ; but, after the leaf is out, any part may be taken 

 off without the least inconvenience. So oaks may be barked 

 while the leaf is budding ; but, as soon as they are expanded, 

 the bark will no longer part from the wood, because the sap 

 that lubricates the bark, and makes it part, is evaporated olf 

 through the leaves. White. 



Kenovation or Leayes. — When oaks are quite stripped 

 of their leaves by chaifers, they are clothed again soon after 

 midsummer with a beautiful foliage; but beeches, horse- 



