Page:Philosophical Transactions - Volume 095.djvu/107

Rh fhe Hmt ^ap ^ -trees is ^imteU itim^- Writer, ^5

I k^ m^i^&fB&A, and it wjis^tMf ^ft'^^pbtiSediaria MeA dlSrti^rti fl¥e Wa}a|iice «ajch p^ik^bn, at le^t t^ ^tifries, th^ 1 (H^ased to %«ieve that some «rrdr had occurred m tite «xperi- iherit : arid indeed I was not at fest safSsfied tilH fead aseettamed feyraearis of compasses adapted to the measurefneift df ^dlids, that the winter-felled pieces of wood were much less than the dfters M4iich they ^uaHed in weight.

The pieces of wood^ vfaich had been the subj^dts of ^ese

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Experiments, weri* agsSn put to dry, wiSi other pieces of the

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ifai^e poles, and I 'yeJirtenlay ascertained ¥he ^specific gravity of boA wrth scarcely aAy Variation in the result. But when omitted the T^Atffla; ^tnd jiitrts adjitelfrt to it, and used the Isr^rers of woiid w^ch had'b^eh more recently fortned, Tfoimd the i^ecffic gravity of the wirfter-feTled wood to be CMily 0.583, artd thaft of the summer-felled to be 0.533 ; and trying the same experimertt with siiYiilar pieces of wood, 1)ut taken from poles which had grown on atirfferent stool, the specific gravity of the winter-felled wood was 0.588, and that of the suAimer- felled 0.534.

It is evident that the whole of the preceding difference ill the specific gravity of lh6 winter and ^summer-fdled wood might have arisen from a greater degree bf contraction in the Former kind, "whilst drying ; 1 therefore proceeded to aScertaifi ^vhether -a(ny given portion of it, "by weight, vould aflbrd a greater quantity of extractive matter, when steeped in waiter. JHaving therefore reduced to small fragments 1 000 grains of each kind, I poured on each portion six ounces of boiling ^vater ; and at the end of twenty-four hours, when the tem- J)erature of the water had sunk to 6o*, I found that the winter-

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felled wood had communicated a much deeper colour to fhe