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I 



60 



AORTAL ARTERIES 



Sect. V. i. 



Neverthelefs to 



that the veffi 

 t a milky jui 



returning from th 



were in 



ty 



ab 



ph 



about a foot and half from the ground, and b 



of plants, which oozed 



forbent veffels, Icut off the ftem of a large fp 



bia heliofcopia, 



down into a cup of a decodion of madder, rubia tindoria, in which i' 

 was confined two or three minutes ; and wiping the end clean, I pre^ 

 fently cut off about an eighth of an inch of it with a fharp penknife 

 and obferved with a common lens the large abforbent veffels to b( 

 coloured with the madder, while the veins continued to effufe a littL 

 white blood : and thus demonftrated both the exiftence of abforben 



velTels and returning veins. 



See Se£l. II. 2. 



At the fame time the upper part of the plant had alfo its ftem fet 

 in the decodion of madder, and after two or three minutes on cutting 



off about the eighth of an inch of 



fimply by wiping th 



be 



mity, the large abforbent veflels were feen by the naked eye 

 coloured with the madder, and the arteries continued to effufe a larg 

 quantity of milky blood. The fame experiments were tried on a plan 

 of tragopogon with the fame event. 



It fhould be here obferved, that the decodlion 



on of madder ftould 

 be frefh made, as otherwife the colouring matter is liable to form it- 

 felf into molecules, too large to be imbibed by any other veffels but 



of the abforbents, which may be fd'id 



femble th 



ptaculum chyli of animal 



pafs from the lower extremitv 



of the caudex of each bud to the upper one. 



A proof of the circulation of the juices of plants has been deduced 

 from the communication of white fpots from a grafted fcion to the 

 whole of the tree in which it was ingrafted. Mr. Fairchild budded 

 a pafl'.n-tree, whofe leaves v/ere fpotted with yellow, into one which 

 bears long fruit. The buds did not take, neverthelefs in a fortnight 

 yellow fpots began to fhew themfelves about three feet above the in- 

 oculation ; and in a ihort time afterwards yellow fpots appeared on 



a (hoot. 



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