1867.] 



Principles in Animal Mechanics, 



21 



Perpendicular 



1. Bice])s femoris (long liead) 0*95 in. 



„ (short liead) 0*56 „ 



2. Semitendinosus 0*40 „ 



3. Semimemhranosus 0"65 „ 



4. Gracilis 0*25 „ 



5. Sartorius 0*00 „ 



Hence we find, for the determination of K (the coefficient of muscular 

 contraction per sc^iiare inch of cross section), 



I' 0-95 X 2-59 



37xl6i=Kx 



610 5=Kx <; 



0-56 X 1-14 

 + 0-40 X 1-87 

 + 0-65 X 2-25 

 +0-25 X 0-89 

 + 000 X 059 



2-460 



0-638 

 + 0-748 

 + 1-462 

 + 0-222 

 + 0-000 



and, finally, 



5-530 



610-5 



5-53 



= 110-41bs. 



It appears from the foregoing considerations that the force of contrac- 

 tion of the muscles, per square inch, is in 



The arm 94-7 lbs. 



The leg 110-4 



These numbers are, perhaps, as near to each other as this class of ob- 

 servations admits of, but I belieye that they do not difter so much, 

 really, as they appear to do, for the following reason : — 



As it was not convenient to procure a good subject destroyed by a 

 violent death, I made use of a powerful man who had died of cholera *, 

 and who had been a blacksmith by profession. Now, it is natural to sup- 

 pose that the muscles of the arm of a blacksmith are more developed 

 than those of his leg, so that their cross section would be relatively too 

 great, and the coefficient derived from that cross section, therefore, too 



* It is well known that after death by Cholera, life continues in the muscles, and 

 manifests itself for some hours by movements, and by the existence of the muscular 

 susurrus. This latter fact, the first notice of which belongs to Dr. Collongues, of Paris,, 

 I have repeatedly verified, as also the continuance of the susurrus in cases of death by 

 tetanus. It appeared to me, therefore, that such a subject as I selected was one well 

 suited to the purpose of my observations. 



