Response in the Living and Non-Living

We have seen that stimulus produces a certain excitatory change in living substances, and that the excitation produced sometimes expresses itself in a visible change of form, as...

Conditions for obtaining electric response--Method of injury--Current of injury--Injured end, cuproid: uninjured, zincoid--Current of response in nerve from more excited to less...

We have already referred to the electrical theory of the visual impulse. We have seen how a flash of light causes a transitory electric impulse not only in the retina, but also...

We have now seen that the electrical sign of life is not confined to animals, but is also found in plants. And we have seen how electrical response serves as an index to the vit...

Effects of molecular inertia--Prolongation of period of recovery by overstrain--Molecular model--Reduction of molecular sluggishness attended by quickened recovery and heightene...

#Fatigue.#--In some metals, as in muscle and in plant, we find instances of that progressive diminution of response which is known as fatigue (fig. 69). The accompanying record...

The effect of the stimulus of light on the retina is perceived in the brain as a visual sensation. The process by which the ether-wave disturbance causes this visual impulse is...

For every plant there is a range of temperature most favourable to its vital activity. Above this optimum, the vital activity diminishes, till a maximum is reached, when it ceas...

In experiments for the exhibition of electric response it is preferable to use a non-electrical form of stimulus, for there is then a certainty that the observed response is ent...

Effect of temperature--Effect of increasing length of exposure--Relation between intensity of light and magnitude of response--After-oscillation--Abnormal effects: (1) prelimina...

We have already seen that metals respond to stimulus by E.M. variation, just as do animal and vegetable tissues. We have yet to see whether the similarity extends to this point...

I shall now proceed to describe another and independent method which I devised for obtaining plant response. It has the advantage of offering us a complementary means of verifyi...

Effect of anæsthetics, a test of vital character of response--Effect of chloroform--Effect of chloral--Effect of formalin--Method in which response is unaffected by variation of...

#Effect of single stimulus.#--In a muscle a single stimulus gives rise to a single twitch which may be recorded either mechanically or electrically. If there is no fatigue, the...

We have seen that the ultimate criterion of the physiological character of electric response is held to be its abolition when the substance is subjected to those chemical reagen...

#Relation between stimulus and response.#--We have seen what extremely uniform responses are given by tin, when the intensity of stimulus is maintained constant. Hence it is obv...

#Diphasic variation.#--This wave of molecular disturbance is attended by a wave of electrical disturbance. (Usually speaking, the electrical relation between disturbed and less...

As already said, in the living tissue, molecular disturbance induced by stimulus is accompanied by an electric disturbance, which gradually disappears with the return of the dis...

One of the most striking effects of external disturbance on certain types of living substance is a visible change of form. Thus, a piece of muscle when pinched contracts. The ex...

I shall now proceed to describe in detail the response-curves obtained with metals. The E.M. variations resulting from stimulus range, as has been said, from ·4 volt to ·01 of t...

Conditions for obtaining electric response--Method of injury--Current of injury--Injured end, cuproid: uninjured, zincoid--Current of response in nerve from more excited to less...

Effect of temperature--Effect of increasing length of exposure--Relation between intensity of light and magnitude of response--After-oscillation--Abnormal effects: (1) prelimina...

Effects of molecular inertia--Prolongation of period of recovery by overstrain--Molecular model--Reduction of molecular sluggishness attended by quickened recovery and heightene...

Conditions of obtaining quantitative measurements--Modification of the block method--Vibration cell--Application of stimulus--Graduation of the intensity of stimulus--Considerat...

Effect of anæsthetics, a test of vital character of response--Effect of chloroform--Effect of chloral--Effect of formalin--Method in which response is unaffected by variation of...

Fatigue in metals--Fatigue under continuous stimulation--Staircase effect--Reversed responses due to molecular modification in nerve and in metal, and their transformation into...