Sir Jagadis Chunder Bose – His Life and Speeches

Special apparatus of extreme delicacy had to be invented, which could magnify the tremor of excitation and also measure the perception period of a plant to a thousandth part of a second.  Ultra microscopic movements were measured and recorded; the length measured being often smaller than  a fraction of a single wave length of light.  The secret of plant life was thus for the first time revealed by the autographs of the plant itself.  This evidence of the plant's own script removed the long standing error which divided the vegetable world into sensitive and insensitive.........  My investigations show that all plants, even trees, are fully alive to changes of environment; they respond visibly to all stimuli.

Sir Jagadis Chunder Bose – His Life and Speeches

When an animal is struck by a blow, it does not respond at once.  A certain short interval elapses between the incidence of the blow and the beginning of the reply.  This lost time is known as the latent period.  In the leg of a frog, the latent period according to Helmwoltz is about one hundredth of a second.  This latent period, however, undergoes appropriate variation with changing external conditions.  With feeble stimulus, it has a definite value, which with an excessive blow is much shortened.  In the cold season, it is relatively long.  Again, when we are tired our perception time, as we may call it, may be greatly prolonged.

Every one of these observations is equally applicable to the perception time of the plant.  In Mimosa, in a vigorous condition, the latent period is six one hundredth of a second, that is, only six times its value in an energetic frog!  Another curious thing is that a stoutish tree will give its response in a slow and lordly fashion, whereas a thin one attains the acme of its excitement in an incredibly short time.

Sir Jagadis Chunder Bose – His Life and Speeches

That not a mimosa alone, but all plants are sensitive was demonstrated by some striking experiments.  A spiral tendril under electric shock was shown to writhe imitating the contortions of a tortured worm.

Sir Jagadis Chunder Bose – His Life and Speeches

The most sensitive organ for perception of a stimulus was the human tongue.... the plant, when tested, was found to be ten times more sensitive than a human being.

Sir Jagadis Chunder Bose – His Life and Speeches

...Dr Bose, instead of applying the stimulant or the anaesthetic in the liquid form to the outer stalk or stem, confined the Mimosa in a little chamber and subjected it to the influence of the vapour of the drug.  The fumes now penetrated and reached the nerves and the plant was made to record, by its own script, the variations, if any, produced by the drugs.  The plant, by its self made records, showed exultation with alcohol, depression with chloroform, rapid transmission of a shock with the application of heat, and an abolition of the propagated impulse with the application of a deadly poison like potassium cyanide.  This variation in the transmitted impulse, under physiological variations, showed that it was not a physical one............. Dr Bose thus showed that the nervous impulse in plant and man is exalted or inhibited under identical conditions.

Sir Jagadis Chunder Bose – His Life and Speeches

The plant is made to imbibe soda water and the growth becomes suddenly exalted some ten times; but a puff of tobacco smoke instantly retards the rate.  To induce further retardation a depressing drug is next applied.  The growth gradually comes to a stop and the quiescent of the spot of light shows life in a state of suspense, the plant is now hovering in an unstable poise between life and death, a slight tilt one way, and life gets interlocked in the rigidity of death.  But the antidote is applied just in time, the torpor and suspense is over and life renews her activity once more with the fullest vigour.

Sir Jagadis Chunder Bose – His Life and Speeches

When the plant had a surfeit of drink, it became excessively lethargic and unresponsive.  By extracting fluid from the gorged plant, its motor activity was at once re-established.  Under alcohol its responsive script became ludicrously unsteady.  A scientific superstition existed regarding carbonic acid as being good for a plant.  But Professor Bose's experiments showed distinctly that the gas would suffocate the plant as readily as it did the animal.  Only in the presence of sunlight could the effect be modified by secondary reaction.

Sir Jagadis Chunder Bose – His Life and Speeches

Pulsative plants were made to record their rhythmic throbbings.  It was shown that the pulse beats of the plants were affected by the action of various drugs, and diverse stimuli, in a manner similar to that of the animal heart.  Perhaps the most weird experience was to watch the death struggle of a plant under the action of poison.

Sir Jagadis Chunder Bose – His Life and Speeches

Plants too are subject to exaltation and depression and at certain hours of the day they are fully conscious and active, while at other hours they are dormant and lazy.  Dr Bose showed by means of a chart that they [his test plants] were fast asleep between 6 and 9 in the morning... a series of records were then shown to illustrate the various degrees of plant consciousness.

Proceeding, Dr Bose said that plants were far more conscious of nature than human beings and described … how plants were sensitive even to passing clouds, which produced in them a depressing effect.  He spoke of the difference between thin and wiry grown plants and those that were stout and robust.  In that respect they again resembled human beings - thin and wiry grown plants were far more susceptible of excitement than the others.  They too needed rest and without it, they were flabby and depressed.

Sir Jagadis Chunder Bose – His Life and Speeches

The whole of the  vegetable world, including rigid trees perceive the changes in their environment and respond to them by unmistakeable signals.  They thrill under light and become depressed by darkness; the warmth of summer and frost of winter, drought and rain, these and many other happenings leave a subtle impression on the life of the plant.

Sir Jagadis Chunder Bose – His Life and Speeches

Dr Bose explained how trees when transplanted frequently died under the shock of the operation just as human beings sometimes died, not from the operation but from the shock caused thereby.  Similarly he discovered and proved that trees could, like human beings, go through severe operations and survive the shock, if placed under the influence of an anaesthetic.

Sir Jagadis Chunder Bose – His Life and Speeches

The life of plants is a mere reflection of our own... shocks and wounds affect them as they affect animals; a common death throb marks the crisis when life passes into death.So a plant can suffer from shock.  But does it 'love', or feel 'hurt?  Does it experience joy or sorrow? Does it suffer pain?  And how can we tell  whether a plant suffers pain?  Plants, like many animals cannot speak, so they cannot express pain.  We don't know, and we do not appear to want to find out.  There is a natural reluctance of any human being to want to believe that a plant suffers pain – pick a cabbage for tea and you could experience endless pangs of remorse and agonies of conscience if you thought you caused it pain.

Sir Jagadis Chunder Bose – His Life and Speeches

When a man receives a blow or shock of any kind, his answering cry makes us realise that he is hurt, but a mute makes no outcry.  How do we realise his sufferings?  We know it by his agonised look, by the convulsive movement of his limbs and through fellow feeling realise his pain.

When a frog is struck it does not cry, but its limbs show convulsive movement.  ...One who feels for the humblest of His creatures alone knows whether the frog is hurt or not. 

Man's sympathy appears to aspire; it is sometimes extended to equals, hardly ever to inferiors.  And so it happens that many would doubt whether the lowly and the depressed possess the fine sense of the 'exalted' to feel the same joy and sorrow, and to resent social tyranny.  When human attitude is so finely discriminative as regards different grades of its own species, it might be extravagant to believe that the frog could have any consciousness of pain.  A concession might however be made that the frog perceives a shock to which it responds with convulsive movements.

But we should be careful about the use of terms, for an eminent biologist insisted that animals never felt any pain; when an oyster is swallowed alive, it did not, according to him, feel any pain but rather a sensation of grateful warmth at contact with the alimentary tract.  The question will remain undecided for no one has as yet returned from the gastric cavity of the tiger to expatiate on the exquisite sensation.

Sir Jagadis Chunder Bose – His Life and Speeches

A question long perplexing physiologists and psychologists alike is that concerned with the great mystery that underlies memory.  But now through certain experiments I have carried out, it is possible to trace 'memory impressions' backwards even in inorganic matter, such latent impressions being capable of subsequent revival.  Again the tone of our sensation is determined by the intensity of nervous excitation that reaches the central perceiving organ.  It would theoretically be possible to change the tone or quality  of our sensation, if means could be discovered by which the nervous impulse would become modified during transit.  Investigation on nervous impulse in plants has led to a discovery of a controlling method, which was found equally effective in regard to the nervous impulse in animal.