111 



The P R E F A C E. 





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I 



» About 20 years fince, I made fever al fid- 

 maftatical Experiments on c Dogs y and 6 years 

 afterwards repeated the fame on Horfes and 

 other Animals, in order to find out the real 

 force of the blood in the Arteries, fome of 

 which are mentioned in the third chapter of 

 this book : At which times I wifhed I could 

 have made the like 'Experiments, to difcover 

 the force of the Sap in Vegetables ; but des- 

 paired of ever effecting it, till about [even 

 years Jince, by mere accident I hit upon it, 

 while I was endeavouring by fever a I ways to 

 flop the bleeding of an old fie m of a Vine, which 

 was cut too near the bleeding feafon, which I 

 feared might kill it : Having, after other means 

 proved ineffectual, tyed a piece of bladder over 

 the tranpuerfe cut of the Stem , 1 found the 

 force of the Sap did greatly extend the bladder ; 

 whence I concluded, that if a longglafs Tube 

 were fixed there in the fame manner, as I had 

 before done to the Arteries of fever al tivbig 

 Animals, I fhould thereby obtain the real af- 

 cending force of the Sap in that Stem, which 

 fucceeded according to my expectation, and 

 hence it is, that 1 have been infenfibly led on, 

 to make farther and fart her refearches by va- 

 riety of Experiments. 



As 



