49-1 PHILOSOPHICAL TRANSACTIONS. [aNN0 1681. 



since the force of the whole muscle is but an aggregate of the contractions of 

 each particular fibre : and this I did in farther explication of an hypothesis, 

 printed in the year 1664, grounded on an experiment made for that purpose 

 before the Royal Society a little before that time. In that printed paper it was 

 said, a muscle in contraction swelled like a bladder blown up, which would raise 

 a great weight according to the experiment shown to the Society : an objection 

 arose, that we did not see any such conspicuous swelling in the belly of a muscle ; 

 to answer which, and explain the hypothesis more clearly, I made this farther 

 addition. 



1. I supposed each distinct carnous fibre as AEF (fig. 2, pi. 14) to consist of 

 an infinite number of very small globules or little bladders, which for explana- 

 tion sake I here express as so many little triangles, e. g. four in this fibre, ALB, 

 BMC, CND, DOE, all opening into each other at the points A, B, C, D, E. 



2. I not only supposed, but endeavoured to prove, that from the artery of 

 each particular muscle, the nourishing juice of the muscle was thrown out and 

 extravasated to run at large among the carnous fibres, and insinuating itself by 

 the constant pulse of the heart was driven on, and after mixing with another 

 liquor it meets with between the fibres in the muscles, came to be strained 

 through the coat of each globule or little bladder into the cavity of it : and 

 likewise, that from each ramification of the nerve within the muscle, that 

 second sort of matter much more fluid and active than the former is extravasated, 

 and these mixed together as beforesaid, enter into each little bladder, and by 

 these constant agitations, ebullition, or effervescence, which with the natural 

 heat that is partly the cause, and partly the constant assister of this motion, and 

 makes that which we call the very life of every part, as long as the animal 

 lives, keeps these globules or small vesicles always distended. How it enters in 

 and sends out its effete particles again into the mass of blood to be discharged 

 by transpiration, and every moment takes in fresh, I endeavoured in those 

 lectures to show at large. 



3. By the aforesaid agitation each little bladder ALB, BMC, &c. is always 

 as beforesaid distended more or less, as long as the animal has life or warmth. 



4. The force or energy of which distention to contract the fibre AF, either 

 into itself from both extremes A and F, or if A be fixed, from F, and so to 

 raise with it any weight, as that at F to E, or any limb as fig. bicip. the arm 

 and hand F, was before demonstrated in the printed paper, and in an experi- 

 ment entered in the journal of the Society. 



5. By these 4 small bladders, I answer the fore-mentioned objection, which 

 was made against the principle laid down in the printed paper, and show that 

 the fibre AF, and so of the whole muscle, does not distend itself as one single 



