( 100 ) 



fize piftured at HIK, or HLM, are of equal dimenfions, and they 

 are fo flcnder, that I can fafely affirm, that if a grain of our common 

 fcowerino- fand were divided into a miUion of equal parts, each of 

 ihofe parts ^^•ould llill be too large to find a paflage through thefe 

 minute velfels. Which being confidered, we may conclude how 

 exquifitely flcnder muft be the veffels in which the circulation is per- 

 formed : and if it w^ere not fo, how could all the parts of our bodies 

 be continually fupplied with nouriihment ? * 



Farther, in the before-mentioned artery D, is another fmall ra- 

 mification at N, which depofits its contents in the vein E at O, and a 

 little higher, at P, is a branch which unites itfelf with the vein 



EatO. 



At R, may be obferved another fmall brancli, proceeding from 

 the fame artery D, which, at S, is joined with a I'mall branch from 

 the artery B, and afterwards both fall into the vein C. 



Again, at T,is another fmall branch, arifing out of the artery D^ 

 ^vhich, at V, fubdivides itfelf into two, and, in two feveral places, 

 namely, at W and X, conveys the blood into the vein E, and from 

 the fame artery another branch arifes at Y, which, at Z, is divided 

 into two, and thefe are united to the vein C at the places marked 

 a and b. 



At a fmall diflance from Y, is another very minute branch at c, 

 which is joined to the vein C at d. 



Farther, at e, another fmall artery branches forth from D, taking 

 the dire6lion ef, and at f is fubdivided into two ftill fmallcr 

 branches, both which join the vein E at ^ and b. 



* A very eminent phyfician of our own country, (Dr Mead) exprcfles himfelf in 

 very nearly the fame words: " Every animal machine is of fuch a nature, that there is a 

 " fort of infinity in its conftituent parts, by which expreflion I mean, that their fibres are 

 " fo extremely fmall, that we cannot difcover the ultimate ftamina, even by the aiSftance 

 " of the beft microfcopes. Had it been othcrwife, aliment could not be conveyed to 

 « every individual part of the body ; nor could the neceflary funcSlions of life be pcr- 

 " formed. Mead's Medical Precepts, in the IntroduSiim. 



