Fig. 117.—Abolition of Response in Nerve, Plant, and Metal by the Action of the same ‘Poison’
The first half in each set shows the normal response, the second half the abolition of response after the application of the reagent.
Thus living response in all its diverse manifestations is found to be only a repetition of responses seen in the inorganic. There is in it no element of mystery or caprice, such as we must admit to be applied in the assumption of a hypermechanical vital force, acting in contradiction or defiance of those physical laws that govern the world of matter. Nowhere in the entire range of these response-phenomena—inclusive as that is of metals, plants, and animals—do we detect any breach of continuity. In the study of processes apparently so complex as those of irritability, we must, of course, expect to be confronted with many difficulties. But if these are to be overcome, they, like others, must be faced, and their investigation patiently pursued, without the postulation of special forces whose convenient property it is to meet all emergencies in virtue of their vagueness. If, at least, we are ever to understand the intricate mechanism of the animal machine, it will be granted that we must cease to evade the problems it presents by the use of mere phrases which really explain nothing.
We have seen that amongst the phenomena of response, there is no necessity for the assumption of vital force. They are, on the contrary, physico-chemical phenomena, susceptible of a physical inquiry as definite as any other in inorganic regions.
Physiologists have taught us to read in the response-curves a history of the influence of various external agencies and conditions on the phenomenon of life. By these means we are able to trace the gradual diminution of responsiveness by fatigue, by extremes of heat and cold, its exaltation by stimulants, the arrest of the life-process by poison.
The investigations which have just been described may possibly carry us one step further, proving to us that these things are determined, not by the play of an unknowable and arbitrary vital force, but by the working of laws that know no change, acting equally and uniformly throughout the organic and the inorganic worlds.
FOOTNOTES:
[21] Verworn, General Physiology, p. 18.
INDEX
| A | B | C | D | E | F | G | H | I | J | K | L | M |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
- Action current
- After-images and their revival, 177
- After-oscillation in photo-sensitive cell, 159, 163
- Anæsthetics, effect on response
- Annealing, effect on response in metal, 101, 138
- Chloral, effect on plant response, 75
- Chloroform, effect on
- Compensator, 22
- Current of injury in nerve, 7
- Curves, characteristics of response, 3
- Death-point, determination of, in plants, 61, 63
- Depressants, effect on inorganic response, 142
- Depression, response by relative, 87
- Dewar on retinal current, 149
- Diphasic variation
- Dose, effect on
- Electrical recorder, 11
- Electrical response. See Response, electrical
- Electric tapper, 24
- Exaltation, response by relative, 89
- Fatigue,
- absence of, under certain conditions,
- apparent, with increased frequency of stimulation,
- diminution of response under strong stimulus due to, in plant, 57
- in metal, 118, 119, 185
- in muscle, 118, 185
- in plant, 20, 185
- due to overstrain, 41
- rapid, under continuous stimulation
- removal of, by rest in plant, 43
- theory of, in muscle, 38, 185
- Injury, current of, in nerve, 7
- Inorganic response. See Metal, electrical response in
- Light,
- after-effect of short exposure to,
- decline and reversal of response under continuous,
- effect of temperature on
- relation between intensity and response to,
- response to,
- McKendrick on retinal response, 149
- Mechanical
- Metal, electric response in,
- abnormal, 125
- abolition of, by ‘poison,’ 143
- additive effect of superposition of stimulus on, 135
- annealing, effect of, on, 101
- by method of
- depressants, effect of, on, 142
- diphasic, 113, 114, 115, 116, 188
- enhancement of, after continuous stimulation, 127, 128, 186
- fatigue, 118, 119, 120, 121, 185. See also Fatigue
- maximum effect due to superposition of stimuli, 136
- modified, 129
- ‘molecular arrest,’ effect of, by ‘poison’ on, 145
- molecular friction, effect of, on, 108, 109
- prolongation of recovery
- relation between, and stimulus, 134, 135
- staircase effect, 122, 186
- stimulant, effect of, on, 141
- temperature, effect of, on, 111
- uniform, 102, 184
- Minchin on photo-electric cell, 165
- Molecular
- Munck on electric response in sensitive plants, 14
- Muscle, fatigue in, 38, 39, 40, 42. See also Fatigue
- Myograph, 2
- Negative variation, response by method of,
- Nerve,
- Nomenclature, anomalies of present, 9, 85
- Photographic recorder, 11, 22
- Plant
- chamber, 64
- electrical response
- radial E.M. response in, 49
- Poison,
- Record, simultaneous mechanical and electrical, of response, 13
- Recorder,
- Response-curve,
- characteristics of, 3
- electrical,
- abnormal,
- abolition of,
- additive effect of stimulus on,
- anæsthetics, effect of, on,
- annealing, effect of, on, in metal, 101, 138
- by method of block, 28, 82, 92
- by negative variation, 9, 18, 87, 183
- by relative depression, 87
- by relative exaltation, 89
- conditions for obtaining, 6, 86, 87
- continuous transformation from positive to negative in metal, 115
- decline and reversal of, under continuous light in photo-sensitive cell, 166
- decline and reversal of, under continuous light in retina, 166
- depressants, effect of, on inorganic, 142
- diminution of. See Fatigue
- diphasic
- dose, effect of,
- enhancement of, after continuous stimulation in metal, 127, 128, 186
- enhancement of, after continuous stimulation in nerve, 127, 186
- maximum effect due to superposition of stimulus, 35, 136
- measure of physiological activity, 13
- molecular
- physiological character of, in plant, 30
- positive and negative, 11
- prolongation of recovery in, by ‘poison’ in metal, 145
- prolongation of recovery in, by ‘poison’ in muscle, 144
- prolongation of recovery in, from overstrain, 106
- relation between, and stimulus
- staircase effect,
- stimulant, effect of, on, in metal, 141
- temperature, effect of, on. See Temperature
- threshold of, 135
- to light. See Light
- uniform
- universal applicability of, 12
- mechanical, 1
- retinal. See Light
- simultaneous mechanical and electrical record of, 13
- Retina. See Light
- Sanderson, Burdon-, on electrical response in sensitive plants, 14
- Spring-tapper, mechanical stimulus by, 23
- Staircase effect
- Steiner on retinal response, 149
- Stimuli, maximum effect due to superposition of,
- Stimulus,
- Waller
- on enhancement of nerve-response after continuous stimulation, 127
- on relation between stimulus and response in muscle, nerve, and retina, 52, 162
- on retinal response, 150, 156, 165
- on reversal of response in stale nerve and retina, 11, 124, 164
- on transformation from abnormal to normal response in nerve after continuous stimulation, 124
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