150 SYLVA BOOK i 



delicate parts. Note, that the sap of the birch, will 

 make excellent mead. 



5. To these observations, that of the weight and 

 virtue of the several juices, would be both useful and 

 curious : As whether that which proceeds from the 

 bark, or between that and the wood be of the same 

 nature with that which is suposed to spring from 

 the pores of the woody circles ? and whether it rise 

 in like quantity, upon comparing the incisures ? All 

 which may be try'd, first attempting through the bark, 

 and saving that apart, and then perforating into the 

 wood, to the thickness of the bark, or more ; with 

 a like separation of what distills. The period also of 

 its current would be calculated ; as how much pro- 

 ceeds from the bark in one hour, how much from the 

 wood or body of the tree, and thus every hour, with 

 still a deeper incision, with a good large augre, till 

 the tree be quite perforated : Then by making a sec- 

 ond hole within the first, fitted with a lesser pipe, the 

 interior heart-sap may be drawn apart, and examin'd 

 by weight, quantity, colour, distillation, &c. and if 

 no difference perceptible be detected the presumption 

 will be greater, that the difference of heart and sap in 

 timber, is not from the saps plenty or penury, but the 

 season; and then possibly, the very season of squaring, 

 as well as felling of timber, may be considerable to 

 the preservation of it. 



6. The notice likewise of the saps rising more 

 plentifully, and constantly in the sun, than shade ; more 

 in the day than night, more in the roots than branch, 

 more southward, and when that, and the west-wind 

 blows, than northward, GPc. may yield many useful 

 observations : As for planting, to set thicker, or thin- 

 ner (si ccetera sint pariaj namely, the nature of the 



