296 



Eoyal Society : — 



37xl6| = Kx i 



or. 



G10-5=Kx 



0-95 X 2-59 

 + 0-56 xl-W 

 + 0-40 X 1-87 

 + 0-65 X 2-25 

 +0-25 X 0-89 

 + 000 X 0-59 



2-460 

 + 0-688 

 +0-748 

 + 1-462 

 + 0-222 

 + 0-000 



5-530 



and, finally, 



K= ^12:^ = 110-4 lbs. 

 5-53 



It appears from the foregoing considerations that the force of 

 contraction 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 observations admits of; but I believe that they do not differ 

 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 suppose that the muscles of the arm of a black- 

 smith 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 small. I therefore com- 

 pared the sections of the biceps humeri and hracliiceus, found 

 by me, -with the only other measurements with which I am 

 acquainted, for the knowledge of which I am indebted to Dr. 

 "VV. Moore of Dublin, who translated the results for me, from 

 the Dutch, of Messrs. Donders and Mansfelt f of Utrecht. 



Cross Sections of Biceps humeri and Brachiceus. 



millims 



1. Biceps humeri (long head) 530 



„ „ (short head) 452 



2. Brachiceus 614 



1596 



sq. 111. 

 0-821 

 0-701 

 0-952 

 2-474 



* 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. Tliis 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. 



t Over de Elasticiteit der Spieren. Utrecht, 1863. 



