446 Dr. J. Wickhain Legg on the [Apr. 6 3 



The method used was as follows : the sciatic nerve was prepared, 

 carefully avoiding all injury of blood-vessels ; the tendon of the gastro- 

 cnemius was attached to a string, and separated from the heel. The frog 

 was then put into a moist chamber, and the string attached to the tendo 

 Achillis fastened to a telegraph lever writiug on a revolving cylinder. 

 The sciatic nerve was then irritated by means of electricity from a Du- 

 Bois-Reymond's coil ; it was applied not of tener than once every 60 s , 

 and only of such amount as to cause the muscle to contract. 



I here extract from my experiment-book a few experiments detailed at 

 length. 



Jan. 22. — Excellent normal curves obtained. *1 grm. of bile-acids 

 injected under skin of back : no change in the curves, save that they 

 grow smaller in height from 15 m to 60 m after the injection. 



Feb. 2.— -3 grm. of bile-acids injected into the lymph-sac of frog : no 

 change from normal curves from 16 ra to 92 m after the injection. 



In three of these experiments changes in the natural curve were 

 noticed after the injection of the bile-acids. The same appearance was 

 seen in all three, namely, that the muscle was a long time in recovering 

 itself. The down stroke of the muscle curve took some space before it 

 reached the abscissa. In two of these cases, however, the muscle curves 

 taken before the injection of the bile-acids showed the same appearance. 

 After the injection the prolongation of the curve became somewhat more 

 marked, varied by returns to almost normal markings. It is thus im- 

 possible to attribute any weight to these variations. The amount of bile- 

 acid given in these two cases was '2 and "3 grm. respectively. In the 

 third case in which this lengthening of the curve was noticed no mark- 

 ings were taken before the injection, so that from this case it is again 

 impossible to draw any inference. The amount of bile-acid given was 

 •3 grm. 



If, then, the bile-acids have no physiological action upon striped 

 muscular tissue, have they yet any chemical influence upon the ventricle 

 alone ? I thought, therefore, of making some experiments upon the 

 action of the bile-acids on the ventricle when separated from the rest of 

 the heart. It is commonly said that the ventricle of the frog's heart 

 continues to beat for some time after it be severed from the auricles. 

 I found, however, that the time was not long enough, nor the beating 

 of the ventricle constant enough, to enable me to judge of the difference 

 in time taken to bring the ventricle to a standstill if immersed in serum, 

 or in serum containing 1 per cent, of bile-acids. I therefore fell back 

 upon a method lately employed by Luciani*. It consists in introducing 

 into the ventricle of the frog's heart a tube divided vertically by a 

 septum, and tying the ventricle on to the cannula below the auricles. 

 The heart is supplied by serum through the double cannula, and each 

 " Arbeiteu aus d. phys. Anstalt zu Leipzig, Jahrg. vii. 1873, p. 120. 



