CORRESrONDENCE OP RAY. 81 



could never happen to wound them in that fortunate 

 hoiu\ Yoiu- experiment communicated to Mr. Olden- 

 bm-gh, and by him imparted to us, that a bough of syca- 

 more, maple, and walnut, when full of sap, cut oif and 

 held perpendicularly, will not drop till you cut off the 

 tops of the twigs, and then it will, to us hath not suc- 

 ceeded. For a branch cut off hath begun to drop before 

 it was topped, nor could we perceive that striking the top 

 did at all promote the running out of the sap ; though, I 

 confess, the day when we made this trial was not very 

 propitious to such an experiment. All that we found 

 was, that exposing the branch to the cold wind, the end 

 downward grew presently dry, and no sign of bleeding ; 

 but holding it in the sun, and in the beams reflected 

 from a wall under the Avind, it presently began to grow 

 moist, and dropped through very slowly. Looking over 

 my notes in 1668, 1 find thus : March 6, we sawed off a 

 small bough of a willow, and held it perpendicularly 

 erected ; it presently dropped, and that indifferently fast 

 considering its smallness, viz. once in fom-teen pidses. 

 This we tried in three boughs, one after another, all 

 which dropped at the same rate, and that without cutting 

 the tops of the branches. 10th, we experimented the 

 same in a sycamore with like success. Notwithstanding, 

 when I get a favorable day, I intend, with aU diligence 

 and exactness, to repeat the same experiment. I am 

 sorry any letter of yours should miscarry, being fraught 

 always with good notions and experiments. I long to 

 know what plant it was you inclosed, and where, in 

 Aristotle, I might find what you mention, and quote out 

 of him. I have not yet tried those luli, which you "WTite 

 so fiercely strike the nose with a fiery and acid scent : I 

 hope you will proceed to make farther experiments with 

 them. As for the Book of Proverbs, I esteem it a toy 

 and trifle not worth the owning ; besides, there are many 

 proverbs of my own knowledge, partly through incogi- 

 tancy and partly in transcribing, omitted ; many out of 

 their due place and order, and some that want explain- 



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