220 



A DISCOURSE 



BOOK III. sary so deep an incision should be made as may serve to exhaust both 

 the venal and arterial moisture : but for this nice speculation, I refer 

 the curious to the already-mentioned Dr. Grew, and to the learned 

 JNIalpighius, who have made other, and far more accurate observations 

 upon this subject". In the mean-time, as to that of the worm in timber- 

 trees, and their rotting, sometimes within, and sometimes without ; ob- 

 serve, that such as gape and rift outwardly, (as does that of the Oak when 

 felled,) the sap thereby let out, the timber and heart within is found to be 

 much more solid than that of the Chestnut and other trees that keep the 

 moisture within ; in these, however seeming sound outwardly, the timber 

 is frequently extremely rotted and perished. Lastly, concerning the 

 bark, though some are for stripping it, and so to let the tree stand till 

 about Mid-June, to preserve it from the worm, (all which time it will 

 put forth leaves, and seemingly flourish,) yet that which is unbarked is 

 more obnoxious to them, and contracts somewhat a darker hue ; (which 

 is the reason so many have commended the season when it will most 

 freely strip ;) however this were rather to be considered for such trees 

 as one would leave round and unsquared, since we find the wild Oak, 

 and many other sorts, felled over late, and when the sap begins to grow 

 proud, to be very subject to the worm ; whereas, being cut about mid- 

 winter, it neither casts, rifts, nor twines, because the cold of the winter 

 does both dry and consolidate ; while in spring, and when pregnant, so 

 much of the virtue goes into the leaves and branches. Happy, therefore, 

 were it for our timber, if some real invention of tanning without so much 

 bark (as the hon. Mr. Charles Howard has most ingeniously offered) 

 were become universal, that trees being more early felled, the timber 

 might be better seasoned and conditioned for its various uses But as 

 the custom is, men have now time to fell their woods, even from mid- 

 winter to the spring, but never any after the summer solstice. 



" The illustrious Hervey has demonstrated that the blood of all animals is made to per* 

 form a circulation by the action of the heart ; but the vegetable not being possessed of such 

 a propelling organ, its juices do not circulate, but rise and fall in the same series of vessels. 

 This, the Rev. Dr. Hales, in his " Vegetable Staticks," has demonstrated in the most satis- 

 factory manner. 



^ Mons. Buffon very justly observes, that the trees intended to be felled for service, 

 should first be stripped of their bark, and then suffered to stand and die upon the spot 

 before they are cut : by this means, the sappy part becomes almost as hard and firm as the 

 heart. 



