Dr. Lifter to Mr. Ray. 9 1 



Wounds upon every like Change of the Weather, 

 . that our Tork-7rees would have bled before now. But 

 I affirm no more than I have feen and tried. 



Mr. Ray to Dr. Lifter. 



Dear $ I M$ Middkton^ March 3 . 1 670. 



I Have not yet had the Fortune to ftrike any other 

 Trees that would bleed, befides Maple, Vine, Sy- 

 camore, Wallnut, Birch and Willow. I have heard , 

 that the Quicken and Afpen-trees will fometimes 

 bleed but I could never happen to wound them in 

 that fortunate Hour. Your Experiment communi- 

 cated to Mr. Oldenburgh^ and by him imparted to us, 

 that a Bough of Sycamore, Maple and Wallnut, when 

 full of Sap, cut off and held perpendicularly, will 

 not drop till you cut off the Tops of the Twigs, and 

 then it will, to us hath not fucceeded. For a Branch 

 cut 6ff hath begun to drop before it was topp'd - 9 nor 

 could we perceive, that ftriking the Top did at all 

 promote the running out of the Sap : Tho', I con- 

 fefs, the Day when we made this Trial was not very 

 propitious to fuch an Experiment. All that we found 

 was, that expofing the Branch to the cold Wind, the 

 End downward grew prefently dry, and no Sign of 

 Bleeding * but holding it in the Sun, and in the 

 Beams reflected from a Wall under the Wind, it pre** 

 fently began to grow moift, and dropt though very 

 {lowly. Looking over my Notes in 1668, 1 find 

 thus. March 6, we faw'd off a fmall Bough of a 

 Willow, and held it perpendicularly erected: It pre- 

 fently dropt, and that indifferently faft, confidering 

 its Smallnefs, viz. once in i4Pulfes. This we tried 

 in 3 Boughs, one after another *, all which dropt at 

 the fame Rat?, and that without cutting the Tops of 



N z the 



