Collected Physical Papers
COLLECTED
PHYSICAL PAPERS
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| BY PROF. PATRICK GEDDES | ||
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| Messrs. LONGMANS, GREEN AND CO. | ||
| london, new york, toronto, bombay, calcutta and madras. | ||
BOSE INSTITUTE TRANSACTIONS, 1927
COLLECTED
PHYSICAL PAPERS
OF
SIR JAGADIS CHUNDER BOSE,
M.A., D.Sc., LL.D., F.R.S., C.S.I., C.I.E.,
FOUNDER AND DIRECTOR, BOSE RESEARCH INSTITUTE,
CALCUTTA
WITH 123 ILLUSTRATIONS
LONGMANS, GREEN AND CO.
LONDON, NEW YORK, TORONTO,
BOMBAY, CALCUTTA AND MADRAS
FOREWORD
THIS book contains a collection of the papers on Physical subjects written by Sir Jagadis Bose. A considerable number of these were written some thirty years ago, shortly after the publication of Hertz's experiments on Electric Waves when the study of the properties of electric waves was being pursued with great vigour. This study was facilitated by the method introduced by Bose, of generating electrical waves of shorter wave length than those in general use. By this method he obtained important results on coherence, polarization, double refraction and rotation of the plane of polarization which are described in the papers collected in this volume. In addition to the purely physical papers there are others which describe the beginnings of Sir Jagadis' application of physical methods to the study of living matter, a subject to which most of his work in recent years has been devoted. The papers make very agreeable reading for the author is never dull. Another aspect of these papers is that they mark the dawn of the revival in India, of interest in researches in Physical Science; this which has been so marked a feature of the last thirty years is very largely due to the work and influence of Sir Jagadis Bose.
Irmily Lodge, Cambridge;
August 16, 1926.
PREFACE
A COLLECTION of papers mainly physical, dating from the year 1895, is published in the present volume. The first object of my inquiry was the optical properties of Electric Waves, brought down to within a few octaves of visible light. In the course of my investigations I was led to the discovery of electric response of non-living matter, such as metals, an account of which was published in 1900 by the International Congress of Science, Paris. The response, like that of living matter, was shown to exhibit fatigue under continuous stimulation, enhancement under chemical stimulants, and permanent abolition under poisons. These results indicated that the response of the more complex and unstable living matter is ultimately the expression of physico-chemical reactions.
My subsequent investigations were directed towards the establishment of the generalisation of the essential unity of physiological mechanism in plant and animal life. The reaction of living tissues, is greatly complicated by the combined effects induced by the fluctuating changes of the environment. This accounts for the complexity of life-movements, which are by no means capricious but are capable of rational explanation by the discovery of the combined action of different factors, the individual reactions to which are unknown to us. The external conditions can be maintained constant for only a short time during which the effect of variation of an individual factor has to be determined. This necessitates special devices for exceptionally high magnification of responsive movements, which otherwise would have been quite imperceptible. The latent period and the velocity of reaction had also to be determined with great accuracy, as also the energy of the incident stimulus.
The difficulties encountered were overcome by the successful employment of various physical methods of high sensibility and accuracy, which will be found of much service in solving not only physiological but physical problems also. A short account of some of these devices, with illustrative examples of their application, will be found towards the end of this book. The High Magnification Crescograph instantly records the imperceptible growth, and the variation induced in it under chemical or electrical stimulation. The Magnetic Crescograph records movements beyond the highest powers of the microscope, the magnification produced being about 50 million times. The Resonant Recorder inscribes time as short as a thousandth part of a second, and enables the most accurate determination of the latent or perception period of the plant and the velocity of transmission of excitation. The Photosynthetic Recorder automatically imprints on a moving drum, the rate of carbon-assimilation by plants. The Magnetic Radiometer enables relative measurement of energy of every ray of the solar spectrum. In conjunction with a special Calorimeter, a very accurate determination has been made of the efficiency of the chlorophyll-apparatus of green plants in storage of solar energy.
J. C. Bose.
Bose Institute, Calcutta;
January, 1927.
CONTENTS
page
Double refraction of visible light by crystals—Depolarisation—Apparatus for polarisation of the electric ray—Radiator emitting short electric waves—Parallel beam of electric radiation—Polariser and Analyser—The Spiral-Spring Receiver—Polarising crystals for the electric ray—Action of Tourmaline • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
1 |
(Asiatic Soc. Bengal—May 1895.)
Transparency to electric radiation of crystals opaque to light—Polariser, analyser and crystal holder—Dependence of sensitiveness of receiver on the applied E. M. F.—Polarising action of Serpentine, Satin Spar, Tourmaline and Nemalite—Selective transparency for polarised ray—Polarising action of vegetable fibres of Agave, Boehmeria nivea, Ananus sativus and Musa paradisiaca—The jute cell polariser and analyser • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
11 |
(The Electrician Dec. 1895.)
Effect due to unequal expansion—Effect due to compression—Polarisation produced by stratified rocks—Effects of rotation of plane of stratification through 360° • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
19 |
(The Electrician December 1895.)
Index of refraction for opaque substances—Unsuitability of the prism method—Advantages of the method of total reflection—Method of a single
semi-cylinder—Method of two semi-cylinders separated by parallel air-space—Method of repetition • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
21 |
(Proc. Roy. Soc. October 1895.)
Relation between dielectric constant and refractive index—Advantages of short electric waves in determination of the index—The Null Method—Determination of index by method of single semi-cylinder—Method of double semi-cylinder separated by parallel air-space—Refraction from glass into air—Refraction from air into glass—Index of refraction of glass for electric ray and for visible light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
31 |
(Proc. Roy. Soc. November 1897.)
Factors in modification of minimum thickness of air-space for total reflection—Influence of the angle of incidence—The influence of wave length—Two right-angled prisms separated by air-space—Minimum thickness for total reflection—Effect of diminution of air-space on total reflection—Partial reflection and transmission complementary to each other—Effect of interposition of a retracting plate in air-space—Wave length of radiation and minimum thickness of totally reflecting air-space—Relation between reflected and transmitted components under diminution of thickness of air-space • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
42 |
(Proc. Roy. Soc. November 1897.)
Relation between critical angle and index of retraction—Determination of the index for liquids—The Refractometer—Successive total reflections during rotation of double semi-cylinders with interposed air-film—The method of repetition—Interference bands preceding total reflection—Index of refraction for distilled water—Variation of index with different strengths of solution—Effect of variation of temperature on the index—Determination of the indices for different rays and the dispersive power—Lecture demonstration • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
56 |
(Unpublished Paper. November 1895.)
Selective transparency for polarised electric ray—Double absorption exhibited by Nemalite, Chrysotile, Satin spar and Epidote—Relation between double absorption and double conductivity—Selective transparency exhibited by ordinary books—The book form of Polariser and Analyser • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
71 |
(Proc. Roy. Soc. January 1897.)
Production of mechanical waves—Oscillatory electric discharge—Failure of oscillatory discharge by disintegrating action of sparks remedied by platinum coating—Electric radiation from a single spark—Magnetic disturbance screened by soft-iron cover—Stray radiation and reflection from the body of the observer—Advantages of short electric waves—Spiral spring and single contact receivers—Enhancement of sensibility by adjustment of E. M. F.—Nickel, aluminium and magnesium receivers—Portable radiation apparatus—Selective absorption—Transparency of liquid air—Varification of the laws of reflection—Opacity due to multiple reflection and refraction—Total reflection by right-angled glass prism—Determination of index of refraction by method of total reflection—Double refraction of the electric ray by crystals belonging to Tetragonal, Orthorhombic, Hexagonal, Monoclinic and Triclinic systems—Double refraction by strained dielectric—Phenomenon of double absorption—Electric tourmalines—Anisotropic conductivity of polarising substances—'Bradshaw' as a polariser • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
77 |
The book form of Polariser and Analyser—No polarisation by a jute-bundle when its length is parallel to the electric ray—Rotation of plane of polarisation by twisted jute-bundle—Rotating elements, positive and negative—Electro-optic analogue of dextrose and levulose—Neutralisation by mixture of equal numbers of positive and negative elements • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
102 |
Production of dark cross by salicine interposed between crossed Nicols—Production of cross in the dark field of electric radiation by interposition of circular
structures—Action of paper disc—Ring systems in woody stems—Production of dark cross by wood and stalactite • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
111 |
(Proc. Roy. Soc. March, 1898.)
Response of Potassium receiver by increase of electric resistance followed by automatic recovery—Response of Sodium and Lithium—Response of metals of alkaline earth—Magnesium, Zinc, and Cadmium—Bismuth and Antimony—Iron and allied metals—Tin, Lead and Thallium—Molybdenum and Uranium—Metals of Platinum group—Copper, Gold and Silver—Untenability of the theory of coherence • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
116 |
Action of ether-waves in modification of molecular structure—Positive and negative responses exhibited by two different classes of substance—Non-discriminative mass action and discriminative molecular action—Change of sign of response under sub-minimal stimulation—Opposite responses under feeble and moderate stimulations in Arsenic and Osmium receivers—Molecular change induced by electric radiation—Allotropic modification under visible radiation—Allotropic changes attended by variation of electric conductivity—The radiation product—Two varieties of Silver—Electrical reversal—Radio-molecular oscillation—Positive and negative variation of conductivity in two different classes of fatigued substances—Restoration of original conductivity by heat and by mechanical vibration • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
127 |
(Proc. Roy. Soc. February, 1900.)
Conductivity variation induced by electric radiation—Modification of response by (a) previous history (b) by change of temperature and (c) by increased pressure of contact—Recording Apparatus for Conductivity and for Electromotive variation—Transition of a Molecular Receiver from Non-recovering to Self-recovering condition—Self-recovering and metrical receivers of positive and negative types—Phosphorescence and Thermo-luminescence—Maximum effect under continuous radiation—Relation between intensity of
radiation and induced conductivity variation—Fatigue and reversal in Ag and Fe3O4 receivers under continued radiation—Electromotive response of Mg receiver under electric radiation—Electromotive response of AgBr cell under light—Fatigue and reversal exhibited by AgBr cell under continued action of light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
163 |
Conductivity variation under mechanical strain—Variation of resistance of surface contacts under electric radiation—Electromotive variation under photic and mechanical stimulation—The Strain Cell—Response to torsional stimulation—Self-recovery—Response independent of direction of torsion—Response to single stimulation—Increasing response under increasing amplitude of torsional vibration—Summated effect of stimuli—Opposite sign of response under subminimal stimulation—Reversal under continuous stimulation—Molecular response common to electric radiation, light and mechanical vibration—Stimulation by light balanced by mechanical stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
192 |
(Proc. Roy. Soc. June, 1901.)
Photographic effect essentially due to molecular action—Difficulty in detection of minute induced change—Primary and secondary reactions—Chemical and physical theories—Relapse of image due to self-recovery—Permanence of after-effect by overstrain—Curve of electromotive variation under light—Preliminary negative twitch preceding normal action—Recurrent reversals under mechanical stimulation—Photo-chemical induction—Effect of intermittent and of continuous light—Photographic effect modified by time-rate—Recurrent reversals under light—Pressure image and inductoscripts • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
208 |
(Proc. Roy. Soc. June, 1901.)
Conductivity variation under rapid electromotive variation due to electric radiation—The Conductivity Recorder—Characteristic curve of a single-point Iron Receiver—Effect of intensity of currents in modification of the characteristic curve—The time-lag—Characteristic curve of a mass of iron-filings—Curve of Cyclic Variation exhibiting hysteresis—Response of self-recovering receiver
to electric radiation—Characteristic cyclic curve of a self-recovering receiver—Curve showing variation of resistance with increasing E. M. F.—Characteristic cyclic curve of negative substance, potassium • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
223 |
(Brit. Asso. Glasgow, 1901.)
Response of Fe3O4 receiver to a single stimulus—Superposition of stimuli—Effects of slow and rapid intermittence of stimulation—Opposite effects of feeble and strong stimulations—Effect of variation of temperature on response of inorganic receiver and of muscle—Effects of stimulants, depressants and poisons • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
253 |
(Congress of Science, Paris, 1900.)
Characteristics of response of a muscle—Mechanical Lever Recorder—Electric Response of living substances—Electric response of plants—Universal applicability of the test of electrical response—Inorganic response—Effect of superposition of stimuli—Fatigue of response in tin—Effect of stimulus of light on metals—An artificial retina—Binocular alternation of vision—Effects of stimulants and depressants on response of metals—Response of inorganic matter "killed" by poisons • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
259 |
(Friday Evening Discourse, Roy. Inst. 1901.)
Electromotive Wave concomitant with molecular disturbance—Method of Block—Recording apparatus—Experiments demonstrating balancing effect—Comparison of electric excitability of two points—The Electric Comparator—Response by method of relative depression or exaltation—Detection of traces of physico-chemical change—Interference effects—The cell form of apparatus—Response dependent on molecular condition—Effects of annealing and of previous vibration—Transformation of abnormal to normal response after continuous stimulation—Response under increased intensity of stimulus—Effect of sub-minimal stimulus—Maximum effect—Chemical excitants and depressants—Opposite effects of strong and feeble dose—Effect of "poisons" in abolition of response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
277 |
(Proc. Roy. Soc. May 1902.)
The Response Recorder—Photographic Recorder—Graduation of intensity of stimulation—Stimulus of torsional vibration—The physiological character of response—Uniform responses—Fatigue—Increasing amplitude of response under increasing intensity of stimulus—Effect of superposition of stimuli—Abolition of response of plant scalded to death—Depression and abolition of response under anæsthetics and poisons • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
306 |
(Journal Linnean Society, 1902.)
Response by variation of electric resistance—The Quadrant Method—Response of leaf to light from a single spark—Effect of increasing intensity of light—Effects of stimulants and depressants—Parallelisms in different modes of response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
317 |
(Life Movements in Plants, 1923.)
Electromotive response to the stimulus of light—Similar responses to mechanical and photic stimulation—The vegetable photo-electric cell—Normal negative response of the leaf to light—Positive response to light exhibited by too young and too old specimens—Effect of increasing duration of exposure—The D- and A-effects—Positive response of actively assimilating plants—Effect of continued action of light—Unmasking of A- and D-effects • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
323 |
(Life Movements in Plants, 1923.)
The Automatic Recorder of assimilation in plants—The Bubbler—Plant as a sensitive detector of variation of light—Hourly variation of assimilation—Effect of infinitesimal trace of chemical substances on assimilation—Efficiency of photosynthetic organ in storage of solar energy • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
331 |
(Physiology of Photosynthesis, 1925.)
Diurnal periodicity in movements of plants—Effects of variation of temperature and of light—The Selenium cell—The Radiograph—The Wheatstone
Bridge—Automatic keys—The Galvanograph—Radiograph of variation of intensity of light for 12 hours in winter—Record of diurnal variation of light and temperature in summer—Light noon and thermal noon • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
338 |
(Life Movements in Plants, 1923.)
Record by the Crescograph—Determination of the absolute rate of growth—Effect of chemical reagents—The Balanced Crescograph—Wireless stimulation and growth—Effects of feeble and of strong stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
347 |
(Proc. Roy. Soc. October 1917.)
Magnification of fifty million times by the Magnetic Crescograph—Demonstration of effects of variation of temperature and of chemical reagents on growth by the Magnetic Crescograph—The Magnetic Radiometer—Discrimination of radiation components in the solar spectrum in the morning and at midday—Comparison of energy of different rays in the solar spectrum • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
357 |
(Physiology of Photosynthesis 1925.)
XXVIII
Accurate record of extremely short intervals of time—Principle of resonance—Determination of the latent period—Measurement of velocity of transmission of excitation in Mimosa pudica—Effect of variation of temperature on the velocity—Nervous impulse in animal and plant—Contractility, Conductivity and Rhythmicity—The Resonant Cardiograph—Characteristic cardiograms of tortoise, frog and fish—Effects of depressant and stimulant on cardiac pulsation—Stimulation and depression of autonomous pulsations of Desmodium gyrans • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
364 |
(Phil. Trans. 1912; Irritability of Plants 1913.)
XXIX
• • • • • • • • • • • • • • • • • • • • • • • • • • • • |
374 |
ILLUSTRATIONS.
fig.
page.
| 1. | Polarisation Apparatus • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
2 |
| 2. | The Radiator • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
3 |
| 3. | The Spiral-spring receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
6 |
| 4. | Determination of index by single semi-cylinder • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
22 |
| 5. | Method of total reflection by two semi-cylinders • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
27 |
| 6. | Two positions of air-space for total reflection • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
27 |
| 7. | Complete Apparatus for electric refraction • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
28 |
| 8. | The Electric Refractometer • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
39 |
| 9. | Section of two totally retracting Prisms • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
45 |
| 10. | Transmission and reflection by double prism • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
46 |
| 11. | Differential Galvanometer for variation of resistance • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
52 |
| 12. | Section of two liquid semi-cylinders separated by air-film • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
58 |
| 13. | Four positions for total reflection • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
59 |
| 14. | The Spectrometer Circle • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
60 |
| 15. | The Method of repetition • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
61 |
| 16. | Mechanical Waves • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
78 |
| 17. | Complete Apparatus for Electric Waves • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
87 |
| 18. | Apparatus for Polarisation of Electric Ray • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
91 |
| 19. | Determination of rotation of plane of polarisation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
105 |
| 20. | Jute elements, positive and negative • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
109 |
| 21. | Paper disc for production of dark Cross • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
113 |
| 22. | Holder for the disc • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
113 |
| 23. | Curve showing electric reversal • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
149 |
| 24. | Response curve for potassium exhibiting increase of resistance • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
151 |
| 25. | Radio-molecular oscillation of Magnesium • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
152 |
| 26. | 'Damped' molecular oscillation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
153 |
| 27. | 'Damped' oscillation curve for a positive substance • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
154 |
| 28. | Response curve for Iron • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
155 |
| 29. | Curve for Arsenic • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
155 |
| 30. | Heat and mechanical vibration in hastening recovery of Iron receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
158 |
| 31. | Heat and mechanical vibration on arsenic receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
159 |
| 32. | Recorder for response to electric radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
169 |
| 33. | Evolution from non-recovering to self-recovering receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
171 |
| 34. | Self-recovering receiver exhibiting negative Touch • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
172 |
| 35. | Record of Ag′ Receiver to single flash of radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
174 |
| 36. | Summated effect exhibited by Ag′ receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
176 |
| 37. | Fatigue and reversal • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
180 |
| 38. | Reversal in Fe3O4 receiver under continuous radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
182 |
| 39. | Electromotive response of Mg receiver under electric radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
186 |
| 40. | Electromotive response of AgBr cell under light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
188 |
| 41. | Fatigue and reversal in AgBr cell • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
190 |
| 42. | The Strain Cell • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
194 |
| 43. | Electromotive variation due to torsion of Zinc wire • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
196 |
| 44. | Electromotive variation under increasing torsional stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
200 |
| 45. | Response under continuous vibration • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
202 |
| 46. | Response to stimulation by Light and by Electric Radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
203 |
| 47. | Response to light and to mechanical stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
206 |
| 48. | Electromotive response of AgBr cell under continuous light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
214 |
| 49. | Recurrent reversals in a Ni cell under continuous stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
215 |
| 50. | Effect of intermittent and of continuous illumination • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
217 |
| 51. | The Conductivity Recorder under cyclic E. M. variation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
230 |
| 52. | Characteristic curve of a single point Iron receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
233 |
| 53. | Effect of lag • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
238 |
| 54. | Curves for metallic filings • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
239 |
| 55. | Cyclic curves showing conductivity hysteresis • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
241 |
| 56. | Responses of self-recovering receiver to single flashes of radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
245 |
| 57. | Characteristic cyclic curve of self-recovering receiver • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
246 |
| 58. | Variation of resistance under increasing E. M. F. • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
248 |
| 59. | Response of Fe3O4 to electric radiation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
255 |
| 60. | Effects of superposition of stimuli • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
256 |
| 61. | Temperature variation on (a) inorganic and (b) muscle response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
257 |
| 62. | Mechanical Lever Recorder • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
261 |
| 63. | Magnetic Lever Recorder • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
263 |
| 64. | Electric response of metals • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
266 |
| 65. | Photographic record of equal and opposite responses (Tin) • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
267 |
| 66. | Incomplete and complete tetanus in tin and in muscle • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
268 |
| 67. | Photographic record of fatigue in tin • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
269 |
| 68. | Stereoscopic design in demonstration of Binocular Alternation of Vision • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
272 |
| 69. | Stimulating action of Na2CO3 • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
274 |
| 70. | Effect of poison in abolition of response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
274 |
| 71. | Balanced response of Metal by Method of Block • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
277 |
| 72. | Response by positive and negative variation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
285 |
| 73. | Electro-molecular Explorer • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
287 |
| 74. | Transformation from positive to negative response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
289 |
| 75. | Modification of "Straight wire" to "Cell form" • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
291 |
| 76. | Effect of annealing on response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
292 |
| 77. | After-effect of continuous stimulation on response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
293 |
| 78. | Transformation of abnormal negative to positive response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
294 |
| 79. | Increased amplitude of response under increasing intensity of stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
295 |
| 80. | Cyclic curves for maximum effects • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
298 |
| 81. | Enhanced response of Platinum by a chemical stimulant • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
300 |
| 82. | Opposite effects of minute and stronger dose • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
301 |
| 83. | Molecular arrest by poison • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
303 |
| 84. | The Response Recorder for plants • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
307 |
| 85. | The Plant Chamber • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
309 |
| 86. | Uniform responses (Radish) • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
311 |
| 87. | Fatigue under shortened period of rest • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
312 |
| 88. | Increasing responses to increasing intensity of stimulus • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
313 |
| 89. | Additive effect of singly ineffective stimuli • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
314 |
| 90. | Abolition of response after scalding • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
314 |
| 91. | Abolition of response under chloroform • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
315 |
| 92. | The Quadrant Method of response by variation of electric resistance • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
318 |
| 93. | Effects of alternate illumination of two pairs of quadrants • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
319 |
| 94. | Response to light from a single spark • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
320 |
| 95. | Responses to increasing intensities of light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
320 |
| 96. | The Vegetable Photo-electric Cell • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
325 |
| 97. | Normal electromotive response • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
327 |
| 98, 99. | Abnormal positive response of too young and too old specimens • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
327 |
| 100. | Effect of increasing duration of exposure to light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
328 |
| 101. | Positive response of photo-synthetic organ (Hydrilla) • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
329 |
| 102. | After-effect of light • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
330 |
| 103. | The Plant-vessel and the Bubbler • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
332 |
| 104. | The Automatic Recorder for Photosynthesis • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
333 |
| 105. | Automatic records of successive bubblings for five minutes during different hours of the day • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
334 |
| 106. | The Self-Recording Radiograph • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
340 |
| 107. | Radiograph of variation of intensity of light during 12 hours • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
344 |
| 108. | Record of diurnal variation of light and temperature in summer • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
345 |
| 109. | The High Magnification Crescograph • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
348 |
| 110. | Crescographic records • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
349 |
| 111. | The Balanced Crescograph • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
352 |
| 112. | Effect of CO2 on rate of growth • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
353 |
| 113. | Response of plant to wireless stimulation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
356 |
| 114. | The Magnetic Radiometer • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
360 |
| 115. | Diagrammatic representation of mechanical recorder • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
365 |
| 116. | Upper part of Resonant Recorder • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
366 |
| 117. | Record of latent period of Mimosa • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
367 |
| 118. | Complete apparatus for automatic record of velocity of transmission • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
368 |
| 119. | Determination of velocity in petiole of Mimosa • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
368 |
| 120. | Enhancement of velocity under rise of temperature • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
369 |
| 121. | Characteristic cardiograms of tortoise, frog and fish • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
371 |
| 122 | Effects of stimulant and depressant on cardiac pulsation • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
373 |
| 123 | Stimulant and depressant on pulsation of Desmodium • • • • • • • • • • • • • • • • • • • • • • • • • • • • |
373 |
This work is in the public domain in the United States because it was published before January 1, 1929.
The longest-living author of this work died in 1937, so this work is in the public domain in countries and areas where the copyright term is the author's life plus 86 years or less. This work may be in the public domain in countries and areas with longer native copyright terms that apply the rule of the shorter term to foreign works.
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