STATE Of THE SAF IN WINTER. 237 



poles which had grown on a different ftool, the fpecific gravity 

 of the winter-felled wood was 0.588, and that of the fummer- 

 felled 0.534. 



It is evident that the whole of the preceding difference in The winter 

 the fpecific gravity of the winter and fummer-felled wood ^ t c al *™. r *"* 

 might have arifen from a greater degree of contraction in the tionof extradt. 

 former kind, whilfi drying; I therefore proceeded to afcertain 

 whether any given portion of it, by weight, would afford a 

 greater quantity of extractive matter, when ileeped in water. 

 Having therefore reduced to fmall fragments 1000 grains of 

 each kind, I poured on each portion fix ounces of boiling 

 water; and at the end of twenty-four hours, when the tem- 

 perature of the water had funk to 60°, I found that the winter- 

 felled wood had communicated a much deeper colour to the 

 water in which it had been infufed, and had raifed its fpecific 

 gravity to 1.002. The fpecific gravity of the water in which 

 the fummer-felled wood had, in the fame manner, been infufed 

 was 1.001. The wood in all the preceding cafes was taken 

 from the upper parts of the poles, about eight feel from the 

 ground. 



Having obferved, in the preceding experiments, that the fap Probability that 

 of the fycamore became fpecifically lighter when it had con- f hls f a P , 1S ex " 



, .. riirir ■ -r t llauftec l m0re or 



tinued to flow during leveral days from the fame incifion, I lefs by the leaves 

 concluded that the alburnum in the vicinity of fuch incifion ha,d and ^ 00ts « 

 been deprived of a larger portion of its concrete or infpiffated 

 lap than in other parts of the fame tree : and I therefore fuf- 

 peeled that I fhould find fimilar effects to have been produced 

 by the young annual moots and leaves ; and that any given 

 weight of the alburnum in their vicinity would be found to con- 

 tain Iefs extractive matter than an equal portion taken from 

 the lower parts of the fame pole, where no annual (hoots or 

 leaves had been produced. 



No information could in this cafe be derived from the dif- Experiment 

 ference in the fpecific gravity of the wood; becaufe the fub- p» e wed that they 



• * * i i /- i- i leave a cettam 



fiance of every tree is molt denfe and fond in the lower parts portion of ex- 



of its trunk ; and I could on this account nid^e only from the traft m ths 



trunk* 



quantity of extractive matter which equal portions of the two 

 kinds of wood would afford. Having therefore reduced to 

 pieces feveral equal portions of wo.od taken from different 

 parts of the fame poles, which had been felled in May, I poured 

 on each portion an equal quantity of boiling water, which Jr 



fuffered 



