LIVING TORPEDOS IN BEELIN. 517 



sation as compared with that of the invertebrates 1 . Boll, who 

 judged merely by the taste of the Liquor cerebrospinalis, was perhaps 

 deceived by the amount of urea discovered by Frerichs and Stadler 

 in the juices of the tissues of the skate 2 . 



However that may be, the organ of the torpedo, far from con- 

 ducting particularly well, does not conduct as well as frog's muscle 

 in the longitudinal direction. In the following statements, i ac- 

 cording to the index attached to it, denotes deflections in scale divi- 

 sions of the aperiodic mirror (with 5000 turns at 100 mm. distance) 

 by the opening shock of the inductorium, when the primary coil was 

 filled with rods and the secondary coil pushed up. The resistances 

 indicated were placed between the clay cones. i denotes that re- 

 sistance between the clay cones was nil; ii g ,ii w , i sW are the deflections 

 with the tube full of f per cent, rock-salt solution, full of tap-water 

 and full of sea-water respectively ; i m is the deflection with the tube 

 full of frog muscle ; finally, ij, and i he are the deflections with the 

 organ in the tube traversed by the homodromous and heterodro- 

 mous current respectively, w , wi w , w sW w m , wj, , and w he are the cor- 

 responding specific resistances referred to the f per cent, rock-salt 

 solution WI G as unity. 



A first series of experiments were performed last summer on the 

 second Torpedo, on the third day, still using the original apparatus 

 which had served for the experiments of 1871 already described. 

 The three organ preparations, the resistance of which was deter- 

 mined with homodromous and heterodromous direction of current, 

 showed the organ current in the right direction and of considerable 

 strength. The result of five determinations in both directions, 

 differing but little from each other, gave a mean of 



i 66-7, iig = 49-2 sc. 



In this condition, without tube, or with the tube full of physio- 

 logical rock-salt solution, the apparatus showed no perceptible 

 irreciprocity of conduction. 



The organ preparations gave respectively: 



III. * w = 29.0, ...*;. = 8-8. 



1 Bulletins de 1'Acadftnie royale des Sciences . . . de Belgique, 3* SeVie, vol. iv. 

 No. 8, Aout, 1882, p. 209. 



2 Erdmann's und Werther's Journal fur praktische Chemie, 1858, vol. Ixxiii. 

 p. 48. 



