379 



come a slight constant current circulating through the galvanometer ; 

 and 2ndly, the fact obtained by Matteucci with the galvanoscopic 

 frog would indicate that some force is evolved during muscular 

 contraction. 



Some differences appear to exist in the results obtained by the 

 author and those of Du Bois-Reymond, viz. the direction of the 

 current. Du Bois-Reymond considers it as direct in the frog, and 

 inverse in man ; the author's experiments indicate it to be direct in 

 both cases, but he thinks that this difference will be found to be 

 more in appearance than in reality, inasmuch as two distinct ques- 

 tions may have been involved, viz. 1st, whether the muscular cur- 

 rent is affected during the act of contraction ; and 2ndly, whether 

 any force is or is not evolved during muscular contraction. 



As the author wishes the paper to be considered as strictly experi- 

 mental, and his object being to establish facts, he has endeavoured 

 to avoid everything of a purely controversial character. 



II. " On a simple Geometrical construction, giving a very 

 approximate Quadrature of the Circle." By C. M. WILLICH, 

 Esq. Communicated by Professor STOKES, Sec. U.S. 

 Received April 17, 1855. 



Let AB be a quadrant of a circle A, B, C. In the arc BC place a 

 chord BD equal to the radius, so that the arc BD is one of 60. 

 Bisect BD in E ; join AE, and produce the joining line to meet the 

 circumference in F. Then AF differs from the side of a square 

 equal in area to the circle by somewhat less than the one four- 

 thousandth part of that side. 



The Society then adjourned to the 24th of May. 



