A new apparatus devised by the lecturer, the Recording Crescograph, is described in the Transactions of the Royal Society, and of the Bose Inst.i.tute. By a compound system of levers the magnification is raised to 10,000 but this is not without great technical difficulties, which cost five years of efforts to overcome. Thus the levers require to be extremely light; this was secured by the use of an alloy of aluminium used in the construction of Zeppelins: this combines lightness with rigidity. Another difficulty almost unsuperable arises from the friction at the bearings of the fulcrum, the best watch jewels made of ruby were employed, but the supply was cut off from Germany by the war. This proved a blessing in disguise, for it forced the lecturer to devise a new principle of suspension using local material. This was found in practice to be far superior to jewel bearings, which became clogged by invisible dust particles present in the air. With this Recording Crescograph many phenomena of extreme interest have been discovered. The plant itself not only recorded its normal rate of growth but the slightest change induced in it by the action of different forces. So delicate was the apparatus that it a.n.a.lysed growth into a series of pulses, a sudden shooting out followed by a partial recoil. It showed how the growth of the plant was r.e.t.a.r.ded by a mere touch, and the time it took the plant to recover from the effect of contact, and all these in course of a few seconds. The effect of different food on growth, the effect of different drugs, or living capacity these and many more became revealed by the automatic record made by the plant. This has opened out fresh and more exact method of medical inquiry, and of practical agriculture.
THE MAGNETIC CRESCOGRAPH
Such unlooked for results called for yet higher magnification, and at first it seemed that further multiplying lever might be added to the previous system. But this failed on account of added ma.s.s and friction; and some altogether new solution had therefore to be sought. Material contact having proved unworkable the ideal weightless and frictionless linking was obtained by introducing a new magnetic contrivance, and this with the surprising potency of magnification from 5 to 100 million times. The mind cannot grasp the meaning of this stupendous magnification; how then could we translate it in terms which may be understood? Let us take once more our slow-footed snail, a magnification of ten million times would convert its speed to something for which there is no parallel even in modern gunnery practice. The 15 inch cannon of the "Queen Elizabeth" has a muzzle velocity of 2360 ft.
per second or 8-1/2 million feet per hour. But the speed of the snail when magnified ten million times would render it 200 million ft. per hour or 24 times faster than the fastest cannon shot. We may next turn to the cosmic movement for a parallel: A point in equator whirls round at the rate of 1037 miles per hour. But a snail with the magnified speed would beat the earth by going round 40 times during the period the earth makes but one revolution!
LIFE IN STATE OF SUSPENSE AND ITS SUBSEQUENT RESOLUTION
With the experiments carried with the Magnetic Crescograph life becomes subservient to the will of the experimenter. The rate of growth is indicated by the speed with which a spot of indicating light moves across the scale. The actual rate of growth is fifty thousandth part of an inch per second; this under magnification is seen by the indicating spot of light to move at the rate of 36 inches per second: this is the normal rate. The plant is made to imbibe soda water and the growth becomes suddenly exalted some ten times; but a puff of tobacco smoke instantly r.e.t.a.r.ds the rate. To induce further r.e.t.a.r.dation 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.
It is true that man is but poorly provided for his voyage of discovery in seas unknown, he can hear little and see less. A single octave of light circ.u.mscribes his vision; even of the visible the size of the ripple of light imposes an impa.s.sable barrier. But he has not been deterred by his limitations but has on the contrary been spurred on its greater efforts in his explanation of the invisible. The mysterious movements of life are not to remain for him inscrutable and indecipherable for all times: but his untiring and single-minded pursuit will someday reveal to him the secret that lies behind the manifestations of life.
--_Amrita Bazar Patrika_, 13-1-1919.
THE NIGHT-WATCH OF NYMPHAEA
Sir J. C. Bose gave the following Discourse on the "Night-Watch of Nymphaea," at the Bose Inst.i.tute, on the 24th January, 1919.
[Sir J. C. Bose"s discourse delivered at the Bose Inst.i.tute, on the 24th January, 1919, dealt with the mysterious phenomenon of recurrent opening and closure of flowers. Some of them open in the morning and close in the evening; others do exactly the opposite opening at night and closing during the day. These various effects have been described as the "waking" and "sleep" movements of plants. The subject had attracted the attention of plant physiologists for more than half a century. After summarising the various results lost in his recent work says that no satisfactory explanation of the sleep movements of plants has yet been forthcoming and that the true theory can only be established after new and exhaustive research. This investigation has been in progress at Sir J. C. Bose"s laboratory for the last five years; and special automatic recorders have been invented by means of which numerous plants have been recording their movements for every hour of the day and night and for many days in succession.]
In course of his discourse the lecturer said "The poets have forestalled the men of science. Why does the water-lily "k.u.mud or Nymphaea" keep awake all night long and close her petals during the day? Because the water-lily is the lover of the Moon and like the human soul expanding at the touch of the beloved, the lily opens out her heart at the touch of the moon beam, and keeps watch all night long; she shrinks affrighted by the rude touch of the Sun, and closes her petals during the day. The outer floral leaves of the lily are green, and in the day time the closed flowers are hardly distinguishable from the broad green leaves which float on the water. The scene is transformed in the evening as if by magic, and myriads of glistening white flowers cover the dark water.
"The recurrent daily phenomenon has not only been observed by the poets, but an explanation offered for it. It is the moonlight then that causes the opening of the lily, and the sunlight the movement of closure. Had the poet taken out a lantern in a dark night; he would have noticed that the lily opened at night in total absence of the moon; but a poet is not expected to carry a lantern and peep out in the dark; that inordinate curiosity is characteristic only of the man of science. Again the lily does not close with the appearance of the sun; for the flower often remains awake up to eleven in the forenoon. A French dictionary maker saw Cuvier, the Zoologist about the definition of the crab as "a little red fish which walks backwards." "Admirable," said Cuvier. "But the crab is not necessarily little, nor is it red till boiled; it is not a fish, and it cannot walk backwards. But with these exceptions your definition is perfect." And so also with the poet"s description of the movement of the lily, which does not open to moonlight, nor yet close to the sun."
THE "SLEEP" AND "WAKING" OF JHINGA FLOWER
The waking and sleeping of the water lily is by no means an isolated instance. My attention was first drawn to another remarkable floral display by the folk song which begins with:
"Our day of work is over Like life"s span, but an hour!
For now behold the gold-starred fields Of opening "Jhinga" flowers!"
Since then I witness every afternoon a glorious transformation in my experimental garden at Sijbaria on the Ganges. The gardener has planted a large field with Jhinga (Luffa acutangula). The flowers when closed at day time are very inconspicuous, the lowest whorl of the sepals being dull green: in my afternoon walk I can hardly recognise the old familiar field, which is now covered with ma.s.ses of flower in their golden glory.
Here also the flowers remain open throughout the night; but they close early in the morning and the fairy field of cloth of gold vanishes suddenly.
COMPLEXITY OF THE PROBLEM
The revolutions made by the plant-scripts led to the discovery of certain new and unsuspected reactions in the life of plants, notably the influence of variation of temperature in modifying thegeotropic curvature. There are at least ten variables, which by their joint effects give rise to over a thousand variations in the resulting movement of plants. The effect of each of these different factors has been isolated and a new theory propounded which offers a complete explanation of the so called sleep movements. The life reactions of plants to the various stimuli of the environment was most strikingly ill.u.s.trated by means of supersensitive Magnetic Crescograph. The plant was shown to perceive the shock of light, to which it made an answering signal, so also to the action of warmth and cold. And it was explained how the various combinations of effects induced by environmental change found diverse expressions in the movement of plants.
The scientific explanations offered for the opening and closing of the water lily is that the flower is closed under sunlight and that the opening takes place under darkness. But Prof. Bose has been able to keep the lily awake even in day time by placing it in a cool place.
Simultaneous record of the movement of the flower and the thermograph of daily variation of temperature proved conclusively that a rapid fall of temperature in the evening brought about the opening of the flower, at first slowly then rapidly, and by 10 p.m. the flower was fully expanded.
About 6 a.m. in the morning there is a rise of temperature, and the reverse movement of closure sets in. The flower continues to close very rapidly the sleep movement of closure is complete by about 10 a.m.
It will be seen how different flowers through their sensitiveness to heat and cold execute movements of "sleep" or of "waking." Some of them have the healthy habit of normal humanity to sleep at night and keep awake at day-time. Others turn night into day, and make up for their long night watch by sleeping it off at the day-time.
--_Amrita Bazar Patrika_, 25-1-1919.
WOUNDED PLANTS
Sir J. C. Bose delivered the following lecture on the "Wounded Plants"
at the Bose Inst.i.tute, on the 7th February, 1919:--
It is a little over four years now that the Embodiment of World Tragedy stalked over Western Europe. The fair field of France and the bright sky was under a pall of battle-smoke. Our sight could not penetrate through the dense gloom, and the mortal cry of the wounded and dying, drowned by hoa.r.s.e roar of a thousand did not reach our ear. But from the time the Sikh and the Pathan, the Gurkha and the Bengali, the Mahratta and the Rajput flung themselves in front of battle from that day our perception has become intensified. The distant cry of those whose life-blood has crimsoned the white field of snow, has found reverberating echo in our heart. What is that subtle bond by which all distances are bridged over, and by which an individual life becomes merged in larger life? Sympathy is that bond by which we come to realise the unity of all life. Before us are spread mult.i.tudinous plants, silent and seemingly impa.s.sive. They too like us are actors in the Cosmic drama of life, like us the play thing of destiny. In their checkered life, light and darkness, the warmth of summer and frost of winter, drought and rain, the gentle breeze and whirling tornadoes, life and death alternate. Various shocks impinge on them, but no cry is raised in answer. I shall nevertheless try to decipher some chapters of their life history.
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. But from this it does not follow that the frog is not hurt, for some would urge that there is a great gap between us and lower animals. One who feels for the humblest of His creatures alone knows whether the frog is hurt or not. Human sympathy always aspires: 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 att.i.tude is so finely discriminative as regards different grades of his 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 by convulsive movements. It is as well that 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.
TEST OF LIVINGNESS
Responsive movements being a test of life, we shall try to construct a scale with which the height of livingness may be measured. What is the difference between the living and the dead? The living answers to a shock from without; the most lively gives the most energetic, the torpid or dying the feeblest, and the dead no answer at all. Thus life may be tested by shocks from without, the size of the answer being the gauge of vitality. The answer of the strong will be violent and almost explosive in its intensity, while the weakling will barely protest. The responsive movements may be recorded by suitable apparatus. The successive responses to similar shocks will remain uniform, if the living tissue remained always the same. But the living organism is always in a state of change for environment is always building us anew, and we are changing everyday of our life. We are thus subject to change, some day we are in a state of high exuberance, and other time in a state of lowest depression: we pa.s.s through numerous phases between the two extremes. Not merely does the present modify, but there is also the subtle impress of memory of the past. The sum total of all these characterise one individual from another. How is the hidden to be made manifest? To test the genuineness of a coin, we strike it and the sound response betrays the true from the false. The genuine rings true and the other gives a false note. In this way perhaps the inner history of different lives may be revealed by shocks and the resulting response.
EFFECT OF WOUND
There are three separate investigations that have been carried out on the effect of wound on plants: The first is the shock effect of wound on growth: this generally speaking r.e.t.a.r.ds or arrests growth. In the second series of investigations the change of spontaneous pulsation of the leaflet of the Telegraph plant was recorded. Death begins to spread from the cut end of the leaflet, and reaches the throbbing tissue which becomes permanently stilled on cessation of life. Experiments are in progress of arrest their march of death, and the cut leaflet which died in 24 hours has now been kept alive for more than a week.
PARALYSIS OF SENSIBILITY
Another series of investigations were carried out on the paralysing effect of severe wound. A leaf of Mimosa was cut off from the plant, and the subsequent histories of the wounded plant and the detached leaf are curiously different. The cutting of one of its leaves had caused a great shock to the parent plant, and an intense excitation spreads over to the distant organs. All the leaves remained depressed and irresponsive for several hours. From this state of paralysed sensibility, the plant gradually recovers and the leaves begin to show returning sensitiveness.
The detached leaf, when placed in a nourishing solution soon recovers, and holds up its head with an att.i.tude indicative of defiance, and the responses it gives are energetic. This lasts for twenty four hours, after which a curious change creeps in the vigour of its responses begins rapidly to wane. The leaf hitherto erect, falls over; death had at last a.s.serted its mastery.
--_Amrita Bazar Patrika_, 10-2-1919.