VOL. III.j PHILOSOPHICAL TRANSACTIONS. 305 



being dispensed and converted into the form necessary for those purposes, when 

 the tree is fullest of sap, in such manner that the sap in the innermost coats 

 feeds the innermost, and the sap of the outward coats the outward parts of 

 fruits, &c. that which remains in the body between the several coats, and be- 

 tween the bark and body, begins to condense there also, first into a jelly, and 

 after into wood, bark, roots, &c. according to the several places to which it 

 subsides. And because it condenses faster in some parts than in others, accord- 

 ing as they are higher or lower, the sap condensed above or below filling less 

 room, must needs cause the sap wliich is not yet condensed in appearance to 

 descend or subside, and to sink as it were lower and lower in the pores of the 

 timber and bark. The trees observed to run are, the vine; the birch plentifully, 

 at body, branches, and roots; the walnut-tree, at the roots and pruned branches; 

 some willows and sallows, and some sorts of maple; the sycamore, which is the 

 greater maple, at a gash made on the bark of its body, and at the root and 

 branches ; the poplar and asp ; to these add the whitting, or quicken-tree, in 

 Latin, Fraxinus Sylvestris, and by some Fraxinus Cambro-Britannica, which in 

 its season, as some affirm, will run plenteously, and whence they, would have us 

 expect-!^ sovereign drink against some stubborn distempers, especially such as 

 are scorbutical and splenetic. I have kept (says Dr. T.) some of the juice 

 of the bCTries (which, being expressed, ferments of itself) these two years in bot- 

 tles, and it has now the taste of an austere cyder : And I suppose from its 

 grateful smell, that it may be kept till it ripen and become a strong vinous li- 

 quor. It is the household drink of some families in these parts about Wales and 

 Herefordshire, and some out of curiosity have brewed ripe berries with strong 

 beer and ale, and kept it till it transcended all other beer in goodness. Dr. 

 Tonge's attempts on the poplar, asp, elm, oak, ash, elder, whitting-berry or 

 quicken-tree, thorn, buckthorn, tile, nut, sloe, briar, bramble, &c. have 

 not succeeded ; and he doubts that they, and all apples and pears, have some 

 degree of gumminess in their juices, so that they will not run. Dr. B. says 

 that apparently the sap rises by the inward bark, where the quick begins, and 

 where the graft first incorporates. He farther remarks, there are circles ob- 

 served in trees, which are the distances of those films or coats by which the 

 tree receives its yearly increase in thickness. Through these, looking full of 

 circular pores, the sap seems to ascend in the same manner between coat and 

 coat, as between the bark and the body ; and probably between the two outer- 

 most of these coats, as large a quantity of sap as between the bark and body. 



The bark is two-fold, outward and inward. The outward is dry, and in some 

 trees rough. The inner is probably a superadded new coat of that year's growth 



VOL. I. Q a 



