PHYSICIAN PHYSICISTS By EDWARD PODOLSKY, M.D.

BROOKLYN, NEW YORK

HYSICIANS, as a class, have his interest in mathematics and physi- perhaps been among the fore- cal phenomena soon proved over- most contributors to the prog- whelmingly greater. He gave up all ress of civilization in its vari- thoughts of medicine and went to ous phases. Almost as importantFlorence as to devote himself exclusively theirP purely medical work, their activ- to physics with such great success that ities in extra-medical spheres have in 1589 he received the appointment added more than a mite to the enjoy- for three years of the chair in mathe- ment of human life. In the field of matics in Pisa where he had begun his literature the names of Chekov, medical studies a few years previously. among the most significant of short- During his incumbency here he per- story writers, Rabelais, the immortal formed his memorable experiments author of “Pantagruel” and “Gar- on falling bodies, but his new views gantua,” Schiller, the great German met with so much opposition that he dramatist, Keats, among the sweetest was forced to resign in 1591. From poets of mankind, Oliver Wendell 1592 to 1610 he occupied the chair Holmes, the popular American poet, at the University of Padua. At Padua and Sir Arthur Conan Doyle, creator he continued his contributions with of Sherlock Holmes, stand out with the perfection of the telescope, micro- especial brilliance. Among others, in scope and air thermometer. With his quite different situations, might be telescopes he made several impor- mentioned Richard Jordan Gatling, tant astronomical observations. Dis- inventor of the Gatling gun, David tinguished by the luster of these Livingstone, who penetrated the achievements, he departed from depths of the dark continent, Leander Padua and accepted the invitation Starr Jameson, of the famous or to Florence, as philosopher and mathe- infamous “Jameson Raid” into matician to the Grand Duke of Transvaal, Leonard Wood, soldier, Tuscany. and Governor General of the A few years later his conflict with Philippines. the Church began. He boldly preached In physics the contributions of the the doctrines of Copernicus, and in medical fraternity extend back many consequence was summoned before hundreds of years and are among the the Inquisition at Rome. The theory most brilliant and significant addi- of the earth’s motion was roundly tions to this important science. It is condemned by the gentlemen of the no exaggeration to say that the science Inquisition, and Galileo was enjoined of dynamics is due to Galileo Galilei to silence. He wisely heeded this (1564-1642), who was born in Pisa. injunction, but only for a few years. He evinced an interest in medicine In 1632 he published, contrary to the long before he distinguished himself edict of 1616, a new work, the “Dia- as a physicist. He entered the Univer- Iogo,” which was a brilliant success sity of Pisa as a medical student, but as an argument in favor of the Copernican theory. This, as was ex- published his great work “De Mag- pected, brought about a second trial. nete,” which was the first great work Galileo was subjected to indignity, on physical science produced in Eng- imprisonment and threats. On his land. Galileo pronounced it “great to knees he was forced publicly to “ab- a degree that is enviable,” but in jure, curse, and detest the error and England it was not appreciated so the heresy of the movement of the highly. In subsequent generations the earth.” For a while he was kept away book was quite forgotten. from his family and friends, but after The most important contribution of he had become blind and wasted with Gilbert is that the earth itself is a disease a little of his liberty was magnet. He pointed out that the restored to him. earth exerted a couple, not a force, The first years after 1632 were upon a compass needle. He also given to the study of dynamics. In introduced the field of force in a 1638, appeared, not in Italy, but in qualitative way, an orbis virtutis, Holland, his dialogues on motion, surrounding each magnet, an idea under the title: “Discourses on two that was much used by Faraday. The new sciences pertaining to mechanics demagnetization of iron by bringing and local motions.” These are now it to a red heat was clearly known to considered his greatest and most sub- Gilbert, and it is highly probable that stantial achievements. Galileo was the he inferred from this fact that mag- first to show that the path of a pro- netization is a molecular phenomenon. jectile is a parabola. Previously it was He said: believed by some that a cannon ball When a piece of iron has been touched moved forward at first in a straight by a lodestone, if it be placed in a hot line and then suddenly dropped verti- fire until it is perfectly red and remain cally to the ground. in the fire some considerable time, it Just as Galileo was the founder of will lose that magnetick strength it has the science of dynamics, William acquired. Even a lodestone itself through Gilbert was the father of magnetic a longish stay in the fire, loses the power philosophy. Dr. Gilbert (1540-1603) of attracting implanted and innate in was born at Colchester, county of it, any other magnetick powers. Essex, England, and studied medicine Some three hundred years before at St. John’s College, Cambridge. anything was known about the re- He travelled a great deal on the combination of ions into neutral mole- Continent where, as well as in Eng- cules Gilbert classified bodies into land he “practised as a physician “electrick” and “non-electrick” ac- with great success and applause.” cording to whether they had effect He was appointed by Queen Elizabeth upon his versorium (electroscope) or her physician-in-ordinary, and she not. settled upon him an annual pension Among the early great mathemat- for the purpose of aiding him in the ical physicists was Jerome Cardan prosecution of his philosophical stud- (1501-1576). His results were purely ies. His first investigations were in mathematical. In mechanics he an- chemistry; but later, for eighteen nounced a law of the inclined plane years and more, he experimented on as follows: The force required to hold electricity and magnetism. In 1600 he a body at rest on a frictionless plane is proportional to the angle which the great discovery of current elec- the plane makes with the horizontal. tricity or “galvanism.” The story This, however, was more theory than goes that his wife was in poor health truth. A simple experiment would and was ordered to eat frogs’ legs. have shown him that this was not so, Galvani prepared them himself. When but he evidently was more interested he had removed their skins, he laid in mathematical trickery than in them on a table near the conductor of experimental truth. His great work, a charged electric machine and left the “De subtilitate rerum,” (Leyden, room. His wife chanced to hold a scal- 1551) represents the best physical pel near the machine while at the learning of his time. In this treatise same time the scalpel’s point touched will be found, among other things, the exposed crural nerve of the frog’s his account of “Cardan’s suspension,” leg. A spark passed and the leg con- very widely used in connection with vulsed violently. She acquainted her the mariner’s compass. This device, husband with this occurrence and he however, Cardan did not claim as his repeated the experiment. This occurred own. He was a man of great learning, on November 6, 1780. Galvani set a graduate of Pavia and Padua, a about to discover the cause. He went successful physician, but unfortu- through quite an elaborate series of nately, a man of rather poor character. experiments and came to the con- All the early thermometers con- clusion that the source of electricity tained air, and the stem was arbitrar- was in the nerve. ily graduated. Being affected by To Thomas Young (1773-1829), a changes in atmospheric pressure, Gal- native of Milverton, Somersetshire, ileo’s air thermometer was very im- England, we are indebted for the re- perfect. The first improvement was vival of the undulatory theory of introduced by the French physician, light after a century of neglect. This Jean Rey, who simply inverted Gali- great scientist had an extraordinary leo’s instrument, filled the bulb with childhood. He could read with con- water and the stem with air. This siderable fluency at the age of two. later was made the thermometric sub- When four years old he had read the stance. On January 1, 1632, he com- Bible twice through; and when he was municated this method to the great six he could repeat the whole of Gold- intermediary among scientists, Pater smith’s “Deserted Village.” He de- Mersenne. But as Rey could not bring voured books, classical, literary and himself to close the upper end of the scientific, in rapid succession. He stem there was a constant danger of grew up fit physically as well as errors from evaporation of the water. mentally. At sixteen he abstained Thus, the thermometer which has from sugar on account of his opposi- played so important a role in clinical tion to the slave trade. At nineteen medicine was developed and improved he entered upon a medical education, by physicists with a medical training. which was pursued first in London, Among the first to interest himself then in Edinburgh, Gottingen, and and investigate in animal electricity finally at Cambridge. In 1800 he was Aloiso Galvani (1737-1798), phy- began medical practice in London; in sician and professor of anatomy in the following year he accepted the Bologna. By accident he was led to chair of Natural Philosophy in the Royal Institution, the metropolitan very close together, about 0.5 cm. school of science established in the apart, in an opaque screen, such as a preceding year by Count Rumford, of visiting card, and then viewing American birth. He held this position through this any small and compara- for two years. From January to May, tively distant source of light. When 1802, he delivered there a series of such a screen is held close to the eye, lectures which were later published the observer always sees a set of under the title, “Lectures on Natural bright dark and dark parallel bands. Philosophy and the Mechanical Arts, ” Either pinhole alone gives a contin- in 1807, ten years after he had received uous bright field; but when the field his degree in medicine. In 1802 he had is illuminated by both there are cer- been appointed Foreign Secretary of tain regions, dark bands, where the the Royal Society which office he held illumination produced by one pinhole for the remainder of his life. is completely annulled by that from Young’s earliest researches were on the other. Just how Young was led the anatomical and optical properties to this experiment is told in his own of the eye. Then followed the first words as follows: epoch of optical discovery, 1801-1804. It was in May, 1901, that I discovered, His theory was laughed at, and he by reflecting on the beautiful experi- proceeded to other studies. The twelve ments of Newton, a law which appears succeeding years were given to medi- to me to account for a greater variety cal practice and the study of philology, of interesting phenomena that any other especially the decipherment of hiero- optical principle that has yet been known. glyphic writing. But when Fresnel, I shall endeavor to explain this law by a in France, began to experiment on comparison. light and to bring into prominence Suppose a number of equal waves of the theory of Young, then the latter water move upon a surface of a stagnant resumed his early studies, and entered lake, with a certain velocity, and to enter a narrow channel leading out of upon his second epoch of optical the lake. Suppose then another similar investigation. In 1801 Young read cause to have excited another series of before the Royal Society, a paper waves, which arrive at the same channel, on the color of thin plates, in which he with the same velocity, and at the same expressed himself strongly in favor time with the first. Neither series of of the undulatory theory of light. waves will destroy the other, but their The great step in this paper was the effects will be combined: if they enter introduction of the principle of the channel in such a manner that the interference. elevations of one series coincide with Everyone knows that when an extra those of another, they must together candle is lighted in a room the illu- produce a series of greater elevations; mination of the room is invariably but if the elevations of one series are so situated as to correspond with the increased, but Dr. Young devised an depressions of the other they must experiment to show that two lights exactly fill up these depressions and the may be added together so as to produce surface of the water must remain smooth; an illumination which is not more, but at least, I can discover no alternative, less than either one. The two sources either from theory or experiment. of light he obtained by making two Now, I maintain that similar effects pinholes or cutting two parallel slits take place whenever two portions of light are thus mixed; and this I call the general in more detail in 1856. Wollaston law of the interference of light. had the gift of originating important The physical researches in light lines of research, but in each case were further carried on by another he just fell short of making a distinct physician, Jean Leon Foucault (1819— step. In 1802, he saw seven lines; the 1868) who was born in Paris. He first five most prominent ones were studied medicine, but his attractions considered by him to be the natural lay elsewhere and between 1845 and boundaries or the dividing lines of 1849 he embarked upon physical re- the pure simple colors of the spec- search. At this period in his activities trum. His explanation is of interest, he was associated with Fizeau. But for it shows how a most plausible after a while they separated and each theory may be destitute of truth. entered upon a series of experiments Said Wollaston: to determine the velocity of light. The colors into which a beam of white Foucault’s researches on the velocity light is separable by refraction, appear of light in air relative to that in water to me to be neither seven, as they usually were carried out at his pavilion in are seen in the rainbow, nor reducible the Rue d’Assas, and were submitted by any means (that I can find) to three, by him in 1853 as a thesis for the as some persons have conceived; but . . . degree of Doctor of Science. In 1851 four primary divisions of the prismatic spectrum may be seen, with a degree he presented a memoir giving his of distinctness that, I believe, has not famous demonstration on the rota- been described or observed before. tion of the earth by means of a pendu- lum. The following year he invented The utilization of color for practical that marvellous piece of mechanism, means was developed to a great the gyroscope. In 1854 Napoleon hi degree by John William Draper (1811- secured a place for him at the Paris 1882) who was born in St. Helen’s, Observatory as a physicist. In spite near Liverpool, and educated at Lon- of immense intellect, as is the case don University. He came to the with quite a few other men of genius, United States in 1883. After studying Foucoult possessed a poorly developed medicine in the University of Penn- body. Lissajous said of him: “It sylvania, he was chosen to the chair seems as if nature had undertaken of chemistry and physiology at Hamp- to establish a striking contrast be- den-Sydney College, Virginia, and tween Foucault’s physique and his later to the same chair in the Uni- intellectual powers. Who could have versity of New York, where he re- divined the man of genius under mained for the rest of his life. In 1847, this frail appearance?” Draper published an important mem- Further contributions to the study oir in which he concluded from experi- of the nature of light were made by ment that all solid substances and another physician, William Hyde probably liquids became incandescent Wollaston (1766-1828), of London, at the same temperature, viz., red who observed the bright spectral heat at 525°c.; that below 525°c. in- bands due to blue light at the base visible rays are emitted, and as the of a candle flame, which are now temperature rises above 525°c. rays called the “Swan spectrum” after of a greater refrangibility are added William Swan who described them successively and continuously; that all spectra of incandescent solids are able to his tastes. He travelled con- continuous, that gases give continuous siderably and devoted a great deal of spectra too, but may have bright his time to the study of physiology. lines superimposed. The last state- An observation made in 1840, on the ment is incorrect. Thirteen years blood of a patient in a tropical climate, later Draper’s correct conclusions was the origin of his scientific writings. were deduced independently from the- It led him to the study of those physi- oretical considerations by Kirchoff, cal forces on which the phenomenon of who started out from the relation vitality depends. Thus, he was led between emitting and absorbing from the contemplation of organic powers possessed by different bodies nature to the preparation of a paper, for radiant energy. “On the Forces of Inorganic Nature,” The first scientific study of the 1842. It was refused publication in formation of dew was made by a Poggendorff’s Annalen, but was ac- London physician, William Charles cepted by Liebig for the May number Wells (1757-1817), and the results of his Annalen. It attracted no men- published in his “Essay on Dew,” tion although it contained the great 1814. It is well known that on a principle that the energy of the world clear, quiet night, the grass radiates is constant. A second paper, 1845, heat into free space, whence no heat could be published only at his own returns. Being a poor conductor, the expense. Several other papers were lower parts of the grass receive little published later. The following story, heat from the earth. The grass cools related by the great mechanician, and vapor condenses upon it. Good Mach, shows Mayer’s alertness of conductors like metals receive heat mind: from the surrounding bodies and During a hurried meeting with Mayer therefore are not covered with dew. in Heidelberg once, Jolly remarked, A cloudy sky hinders the formation with a rather dubious implication, that of dew by returning the radiated if Mayer’s theory were correct, water heat. Winds are unfavorable because could be warmed by shaking. Mayer they carry heat to the cooling objects. went away without a word of reply. Wells supposed that only a very small Several weeks later ... he rushed into part of the dew deposited comes the latter’s presence, exclaiming: “Es from vapor rising from the earth or ist so” [It is so]. It was only after con- evaporation from plants. siderable explanation that Jolly found out what Mayer wanted to say. Another great physicist who was trained as a physician was Robert The mind of Mayer became seriously Mayer (1814-1878) who was born in affected by the lack of appreciation Heilbronn, Germany. In the gym- of his ideas, by controversies regarding nasium and theological school he his rights of priority, as well as the gave no evidence of any great intellec- death of two of his children. On May tual power which was to distinguish 28, 1849, he unsuccessfully attempted him in later life. In 1832 he entered suicide by jumping from a second- upon the study of medicine at Tub- story window. After a seeming recov- ingen, and in 1838 began to practice. ery he wrote a paper on the mechani- Unfortunately, he did not find the cal equivalent of heat. In 1851 he was work of a practising physician agree- placed in an insane asylum, but after a year he was released. He, however, were of the highest order. His theory never completely regained mental of color is well known; his work in equilibrium. In 1858 a few voices acoustics is a classic, and the greatest were heard in Germany in praise of text on physiological optics was writ- Mayer, but the one who did most to ten by him. bring him historical justice was John Thermo-electricity was discovered Tyndall, who in 1862 lectured be- in 1821 by Thomas Johann Seebeck fore the Royal Institution on Robert (1780-1831) who was born in Reval, Mayer and also translated several of Esthonia, Russia. At the age of Mayer’s papers. seventeen he left his native country, Perhaps the greatest physician never to return. He studied medicine physicist was Hermann von Helm- at Berlin, but being well off he did holtz (1821-1894). He was born at not enter practice, and instead de- Potsdam, Germany, studied medicine cided to devote himself to the pursuit in Berlin and became an assistant at of science. From 1802 to 1810 he lived the charity hospital there immediately in Jena where he was the personal after his graduation. Following this friend of Schelling, Hegel, Ritter he became a military surgeon in the and other prominent Germans. Being city of his birth (1843-47). In succes- elected a member of the Berlin Acad- sion he was a teacher of anatomy at emy of Sciences he took up his resi- Berlin, of physiology at Konigsberg, dence in that city. Oersted’s experi- later at Bonn and Heidelberg (1858- ments induced him to enter upon a 1871). In 1871 he accepted the chair long series of electrical investigation. of physics at the University of Berlin. With a view of verifying certain Throughout his life he was of the first speculations regarding the magnetic rank as a physiologist, physicist and character of the electric current, he mathematician. His famous paper on established an electric circuit consist- energy, entitled “Die Erhaltung der ing partly of copper and partly of Kraft,” which as a youth of twenty- bismuth. One metallic junction he six he read before the Physical Society held in his hand. He satisfied himself of Berlin in 1847, was at first looked that the resulting deflection of the upon as a fantastic speculation. The galvanometer needle arose from the editor of Poggendorff’s Annalen, who difference in temperature of the metal- in 1843 declined Mayer’s paper, re- lic junction, brought about by the jected Helmholtz’s also. However, heat from his hand. He found similar in 1847 this paper was published in effects by cooling one of the junctions; pamphlet form. For a time it attracted the effects varied for different metals, little notice, but in 1853 it was and were greater for greater differ- attacked by Clausius. Later it sub- ences of temperature. From these jected the author to virulent attacks investigations arose the science of from Duhring and others, who ac- thermo-electricity, one of the great cused him of being a dishonest bor- contributions to man’s store of prac- rower from his forerunner, Robert tical knowledge. Mayer. In 1847 Helmholtz who had In other fields of practical physics heard nothing of Mayer acknowledged contributions of physicians stand out that physician physicist’s priority. as of great importance. In the winter Helmholtz’s contributions to physics of 1844 Dr. John Locke, Professor of Chemistry at the Medical College and in 1851 placed before the city of of Ohio, lectured before its president Boston a detailed plan for a tele- and officers on magnetic clocks. Dr. graphic system of transmitting fire Locke showed how the beats of a alarms. Dr. Channing worked out a clock might be repeated and how complete system of fire alarm boxes, another clock at a telegraphic dis- bells, receiving electrical apparatus, etc. Ten thousand dollars was finally tance might be made to move with- appropriated by the city government out pendulum or weights. In 1849 in order to put his plan into operation. the government called Locke to the The doctor likened his telegraphic Naval Observatory in Washington system to the human brain and nerv- where he constructed the first electro- ous system, and drew a strong anal- chronograph. Today his invention, ogy “between the functions of the the electric clock, is in wide use motor nerves and the apparatus of throughout the country. the anial system.” Another physician’s contribution to There is but little doubt that one practical physics wrhich has had a can go on for many more pages detail- great influence on modern civiliza- ing the contributions both to pure tion is the fire alarm system. In the physics and applied science of the middle of the last century Dr. William physician physicists. Their work in F. Channing applied the principle of this field has been as fully important electric telegraphy to the fire alarm and significant as in so many others.