Image from page 387 of “General physiology; an outline of the science of life” (1899) – more Marine Life goodness curated by www.SardineRunPE.co.za
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Title: General physiology; an outline of the science of life
Year: 1899 (1890s)
Authors: Verworn, Max, 1863-1921 Lee, Frederic S. (Frederic Schiller), 1859-1939, ed. and tr
Publisher: London, Macmillan and co., limited New York, The Macmillan company
Contributing Library: Columbia University Libraries
Digitizing Sponsor: Open Knowledge Commons
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rhythmic con-tractions in the sartorius muscleby chemical stimulation. STIMULI AND THEIR ACTIONS 371 which it exists, or upon being transferred tovarious luminous Bacteria, which produce, e.g. fresh water. The the luminosity of dead sea-fish, behave similarly. Finally, the living substance of nerves and ganglion-cells can be excited by chemical stimulistance itself is not visiblewithout special methods:but a clear expression of itin motor nerves is exhibitedin the contraction of musclessupplied by them. If, e.g.,the sciatic nerve of a frogbe stimulated by its centralend being dipped into gly-cerine, a concentrated solu-tion of common salt, or asolution of a mineral acid,an alkali, a metallic salt orsugar, contractions of theleg-muscles of the frog takeplace, and prove that thenerve is excited. Excita-tion by chemical stimuli canbe observed in the excisednerve also by means of thegalvanometer through thedevelopment of electricity,from the resting nerve. The excitation in the nerve-sub-
Text Appearing After Image:
Fig. 103. -Noctiluca miliaria, a marine flagellate-infusorian cell. which influences the current derived b. The Phenomena of Depression In contrast to the exciting effects of the chemical stimuli justmentioned are the effects of certain chemical substances, whichdepress or wholly suppress vital phenomena. These substancesare, hence, termed narcotics or anaesthetics. Among them belong es-pecially those that depress all forms of living substance andall vital phenomena: alcohol, ether, chloroform, and chloralhydrate. With these belong the great group of alkaloids,comprising morphine, quinine, veratrine, digitaline, strychnine,curare, etc., some of which act upon a great variety of living cells,while others affect specific cells only, especially those of thecentral nervous system. The depressing effects of narcotics upon the phenomena ofmetabolism have been studied especially by Claude Bernard (78).This well-known Parisian physiologist showed that metabolism issuppressed by chloroform-nar
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