( ^6 ) 



1 have fometimes (as I before hinted) fecn fome of the perpendi- 

 cular or aicending veflels in the fir, much larger in diameter than 

 others ; but thefe are fo few, that it is very rare to obferve them. 



Injig. 8, between B and C, are to be feen the minute round 

 apertures in thofe parts of the afcending tubes or air veflels, where 

 the horizontal ones are feen, which apertures I conceive are deftined 

 to tranfmit air or the juices of the tree, from the afcending to the 

 horizontal veflels. 



Thefe difcoveries of mine, refpe6ling the fmallnefs or thinnefs 

 of the veflels or tubes, coinpofing the fubftance of trees, may not 

 eafily be credited by many, as not comprehending how, by reafon 

 of their exceeding Imallnefs, any juice or liquor can poflibly pafs 

 through them, and, what is more difficult to conceive, how through 

 i'uch veflels afcending perpendicularly, any nutritive fubftance can 

 be derived from the root of the tree to the extremities of the upper 

 branches. 



But as, on the one hand, it is out of the reach of our finite capa- 

 cities to comprehend the extent of the Univerfe ;* fo on the other, 

 we are equally unable to conceive the minutenefs of the veflels and 

 component parts of which not only animals, but alfo vegetables are 

 formed, and much lefs, how the parts of matter are united toge- 

 ther, or how one part grows out of, or is added to, another. 



* This fentiment is more fully exprefled and largely dilated on, in the SpecStator, No. 420, 

 and many of the reafonings in that Paper feem to have been taken from the difcoveries then 

 xiewiy made by our Auihor and his cotcmporaries. 



