I 



' 5' 



•of 



of 

 )er. 



nch 



hy. 



ree, 



any 



)ro- 

 riii 



nnes 



any 

 im- 



I 



in 



on- 



I 



;hlii 

 the 



3, in 

 d to 

 the 



n 



ks 



s to 

 .sin 



ion, 



ugh 



Sect. II. 6 



ABSORBENT VESSELS 



5 



a 



veo-etable ftiek both upwards and downwards, by fett 



end of it in a cup of water in the receiver of 



pump, and 



haufting the air, Veg. Stat. p. 1 54 ; whence he concludes with Grew, 

 that thefe are air-veffels or lungs for the purpofe of refpiration, and 



that they receive atmofph 

 There is one objedion to th 



their natural ftate 



fe 



as 



effels, which is, that 



they have no communication with the horizontal air-veffels above de- 

 fcribed ; for by blowing forcibly through a piece of dry cane immerf- 

 ed deep in water, no air is feen to bubble out of the fides, but only 

 from the bottom of it. It may indeed be fuppofed, that the longi- 

 tudinal cavities in dry cane may not confift of the abforbent vefTels 

 above defcribed, but of the interftices between them, as the coats of 

 thofe abforbent veffels, confifting of a fpiral line, may be thought to 



and their interfl: 



con- 



clofe up by their vermicular contradion ; 

 fiftinor of vegetable cellular membrane, may be fuppofed, when dry, to 

 become the tubes in cane. But in this cafe the longitudinal canals 

 in dry cane would not be circular cylinders, whereas they are fo re- 

 prefented in a figure of a piece of cane much magnified by Dr. Grew, 

 Tab. XX. who has in the fame figure given the mouths of hori- 

 zontal air-vei^'els of circular form and larger diameter. 



But there is another infuperable objedlion to this idea of their ufe, 

 which is, that thefe veffels equally exift in the roots of plants as in 

 their trunks ; and according to Malpighi with larger diameters ; and 



probably term 



Uy only in the roots 



d 



they 



there not expofed to the atmofph 

 of refpiration ; 



air 



thelefs 



;re, they cannot ferve the purpofe 

 I its combined flate, or even as dif- 

 may be abforbed by thefe veffels ; and' may appear, 

 when the preflure of the atmofphere is removed in the exhaufted 



hen expanded by heat, as is feen in the froth at one end 



folved 



of 



O 



ftick, when the other end is burnino: in the fi 



6. Thefe 



ble abforbents differ from thofe of 



th 



e 



facihty, Vv'ith which they carry their fluids either way; for a forked 



branch 



