236 STATE OF THE SAP TK WINTER. 



^fdlttpolcs* Il§ghter by P riv '" tlon of its Proper quantity of nutriment. The 

 in an oak coppice mo ^ eligible method therefore, which occurred to me, was to 

 in winter and f e l ( .ft am | mar k j n ( | )e w j nt er fome of the poles of an oak 

 fpring and com- . . ,. . , r r . 



paring them. coppice, where air are of equal ape, and where many, or the 



fame fize and growing with equal vigour, fpring from the 

 fame (tool. One half of the poles which I marked and num- 

 bered were cut on the 31ft of December, 1803, and the 

 remainder on the J5th of the following May, when the leaves 

 were nearly half grown. Proper marks were put todiflinguifli 

 the winter. felled from the fummer- felled poles, the bark being 

 left on all, and all being placed in the fame filuation to dry. 

 The winter In the beginning of Auguft I cut off nearly equal portions 



d-DfeftTft* 1 Wa5 *™ m a wmter and rummer-felled pole, which had both grown 

 Ccafoning, on the fame ftool ; and both portions were then put in a 



fituation, where, during the feven fucceeding weeks, they 

 were kept very warm by a fire. The fummer-felled wood was, 

 when put to dry, the mod heavy ; but it evidently contained 

 much more water than the other, and, partly at leaft, from 

 tin's caufe, it contracted much more in drying. In the begin- 

 ning of October both kinds appeared to be perfectly dry, and 

 I then afcertained the fpecifie gravity of the -winter-felled 

 wood to be 0.679, and that of the fummer-felled wood to be 

 0.609 ; after each had been immerfed five minutes in water. 

 — by more than This difference of ten per cent, was confiderably more than 

 ten per cent. j j lac j anticipate anc j jt was no t till I had fufpended and taken 

 off from the balance each portion, at leafl: ten limes, that I 

 ceafed to believe that fome error had occurred in the experi- 

 ment: and indeed I was not at laft fatisfied till I had afcertained 

 by means of compaffes adapted to the meafurement of folids, 

 that the winter-felled pieces of wood were much lefs than the 

 others which they equalled in weight. 

 The difference The pieces of wood, which had been the fubjects of thefe 

 muctfWlSr f ° experiments, were again put to dry, with other pieces of the 

 newly formed fame poles, and I yefterday afcertained the fpecific gravity of 

 layers of each. bo , h wjth f carce i y any variation in the refult. But when I 

 omitted the medulla, and parts adjacent to it, and ufed the 

 layers of wood which had been more recently formed, I found 

 the fpecific gravity of the winter-felled wood to be only 0.583, 

 ' and that of the fummer-felled to be 0.533 ; and trying the 

 fame experiment with fimilar pieces of wood, but taken from 



pples* 



