. Electro-physiology. Electrophysiology. ELECTRICAL FISHES 429 Raymond's zinc trough, as in Fig. 271. It is evident that there must under these conditions be cur- rent escape into the galvanometer circuit, which must be investigated, and allowed for at the end of the experiment. There is in the first place the not very striking fact that make shocks do not excite the organ- preparation, while break induction currents elicit effective discharges. The electrical organ therefore reacts like most excitable substances. It is further remarkable that (according to Sachs' experiments) break shocks het
. Electro-physiology. Electrophysiology. ELECTRICAL FISHES 429 Raymond's zinc trough, as in Fig. 271. It is evident that there must under these conditions be cur- rent escape into the galvanometer circuit, which must be investigated, and allowed for at the end of the experiment. There is in the first place the not very striking fact that make shocks do not excite the organ- preparation, while break induction currents elicit effective discharges. The electrical organ therefore reacts like most excitable substances. It is further remarkable that (according to Sachs' experiments) break shocks heterodromous to the discharge from the organ excite more strongly than homodromous currents. Schonlein was unable to confirm this for Tor- pedo. Induction shocks passed trans- versely to the organ appear to have the least effect. A rapid series of induced (alternating) currents (tetanus) gives large deflections in the direction of the discharge, with a distance of coil at which single break shocks, under the most favourable conditions, give little or no effect. This is again the same reaction as on stimulating ganglion- and gland-cells, as well as all sluggishly reacting contractile substances. The simple method of curarising, by which it is so easy to exclude the nerves in the muscles of most ver- tebrates, breaks down almost entirely for the electrical organs, since electrical fishes, and more especially Torpedo, are, like all other fish, comparatively immune to curare. This is evident in the nerves to the muscles, but still more in the electrical organs. FIG. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Biedermann, W. (Wilhelm), 1852-1929; Welby, Frances A. (Frances Alice). London : Macmillan
Size: 801px × 3121px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1800, bookdecade1890, bookpublisherlondonmacmillan
