not sufficiently high to show the individual pulsations; it is therefore necessary to carry the magnifications to five million times in demonstration of the alternate expansion and contraction of the cellular pump in the act of propelling the sap.
The Magnetic Sphygmograph.
The magnetic instrument for producing enormous magnification is shown at work. A beam of light reflected from the mirror attached to the astatic magnetic
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Record of Mechanical Heart-beat of Plants. Note falling and rising sap-pressure showing constituent heart-beats
system is thrown on the screen. When a dead plant is attached to the apparatus, the indicating beam of light remains quiescent, the heart-beat of the “plant having been stilled in death. But the imperceptible heart-beat of the living plant is outwardly manifested by alternate swings of the beam of light. The frequency varies in different plants from fifteen to five beats per minute. A depressing agent causes diminished sap-pressure as seen in the sudden rush of the light beam to the left, the down-stroke of the individual beat being relatively large. A stimulating agent causes, on the other hand, a rush of the beam of light in the opposite direction, the up-stroke being more pronounced than the down-stroke. The unseen waxings and wanings of life are thus, for the first time, revealed by the moving trail of light.
Utility.
I have been often asked: What could be the practical use of these researches on the recondite life-phenomena of plants? A similar question used to be asked when so far back, as 1894, I succeeded in transmitting energy by wireless electric waves for starting machinery at a distance or exploding a distant mine. The invention of the galena receiver in my laboratory also solved the difficulty of long distance transmission. All this was regarded at the time as a mere scientific curiosity.
All the efforts of the Institute are concentrated on the establishment of the great generalisation that all life is one and that an identical mechanism is operative in both animal and plant tissues. This is demonstrated by a similar motile mechanism, and by the discovery of a very highly differentiated nervous system in the plant. It is proved by the throbbing pulsation in the plant which in the animal is the heart-beat; by the violent spasm that occurs in the plant at the supreme crisis of death. Surprising also are the identical effect of drugs, of stimulants and poisons on the two types of life, this being regarded by leading physicians as of great importance in advancing the Science of Medicine. By researches on growth rendered possible by the invention of the High Magnification Crescograph, the Laws of Growth are being established, a knowledge of which is essential for any real advance in Practical Agriculture. Overwhelming are the new results that are being accumulated every day, but we cannot stop to reap the fruit which must be left for others. The stress and burden are to be for those only who have started on the great adventure into the region of the Unknown.
For the economic welfare of a vast continent like India, there must always be
