Recherches sur une Propriété nouvelle de la Matière. Activité radiante spontanée ou Radioactivité de la Matière. Offprint from: Mémoires de l'Académie des Sciences de l'Institut de France, Tome 46.

Paris: Firmin-Didot et Cie. 1903.

First edition, very rare offprint, of Becquerel's definitive memoir on his discovery of and investigations into radioactivity, including his identification of electrons in radiations of radium, and his account of the evidence of a radioactive transformation. “In 1903, Becquerel published the above massive volume of some three hundred and sixty pages, 'Researches into a New Property of Matter, or Radioactivity in Matter', which is his definitive work, containing a chronological narrative of his investigations, his mature conclusions and a bibliography of two hundred and fourteen treatises on radio-activity, dating from his own first paper in 1896" (PMM). "In 1896, [Becquerel's] previous work was overshadowed by his discovery of the phenomenon of natural radioactivity. Following a discussion with Henri Poincaré on the radiation which had recently been discovered by Röntgen (X-rays) and which was accompanied by a type of phosphorescence in the vacuum tube, Becquerel decided to investigate whether there was any connection between X-rays and naturally occurring phosphorescence. He had inherited from his father a supply of uranium salts, which phosphoresce on exposure to light. When the salts were placed near to a photographic plate covered with opaque paper, the plate was discovered to be fogged. The phenomenon was found to be common to all the uranium salts studied and was concluded to be a property of the uranium atom [Chapters I-III of the offered work]. Later, Becquerel showed that the rays emitted by uranium, which for a long time were named after their discoverer, caused gases to ionize and that they differed from X-rays in that they could be deflected by electric or magnetic fields [Chapters IV & V]” (Nobel Lectures, Physics 1901-1921). “Returning to the field he had created, Becquerel made three more important contributions. One was to measure, in 1899 and 1900, the deflection of beta particles, which are a constituent of the radiation in both electric and magnetic fields. From the charge to mass value thus obtained, he showed that the beta particle was the same as Joseph John Thomson’s recently identified electron [Chapter V]. Another discovery was the circumstance that the allegedly active substance in uranium, uranium X, lost its radiating ability in time, while the uranium, though inactive when freshly prepared, eventually regained its lost radioactivity [Chapter VIII]. When Ernest Rutherford and Frederick Soddy found similar decay and regeneration in thorium X and thorium, they were led to the transformation theory of radioactivity, which explained the phenomenon as a subatomic chemical change in which one element spontaneously transmutes into another. Becquerel’s last major achievement concerned the physiological effect of the radiation. Others may have noticed this before him, but his report in 1901 of the burn caused when he carried an active sample of the Curies’ radium in his vest pocket inspired investigation by physicians, leading ultimately to medical use [Chapter VII]” (Britannica). For “his discovery of spontaneous radioactivity” Becquerel was awarded half of the Nobel Prize in Physics 1903, the other half being given to Pierre and Marie Curie for “their joint researches on the radiation phenomena discovered by Professor Henri Becquerel.” This is an offprint from Mémoires de l'Académie des Sciences de l'Institut de France 46 (1903). The journal issue could be confused for the offprint, as it contains no articles other than Becquerel’s, but the offprint has the title ‘Recherches sur une Propriété nouvelle de la Matière’, while the journal issue has only the name of the journal on the title (there are a few other differences – see below). While the journal issue is regularly seen on the market, RBH lists no copy of the offprint since 2002 (that copy having been rebound and the wrappers repaired with tape).

“Becquerel was born in Paris and studied civil engineering at the École Polytechnique. Having obtained his diploma in 1877, he opted for a career as a scientist. He did research in optics, took his PhD in 1888, and was elected a member of the Academy of Sciences a year later. In 1892 Becquerel became professor at the Natural History Museum in Paris, like his father and grandfather before him (and later his son after him). In 1895 he was also appointed professor at the École Polytechnique. His speciality (as that of his father and grandfather) was the study of fluorescence and phosphorescence. These are properties of materials to emit light if properly stimulated, usually by irradiation with light of shorter wavelength than that of the emitted light… In the Académie des Sciences Röntgen’s discovery [of X-rays] was discussed in January 1896. It was quite natural for Becquerel to wonder, as Poincaré had suggested, whether X-rays were produced by some kind of phosphorescence.

“Becquerel began investigations with materials which were phosphorescent if exposed to sunlight. Because of its scientific tradition the Museum possessed many samples of such material. This was a decisive advantage which he had over his competitors. His technique was clear and simple. He wrapped a photographic plate in thick black paper, protecting it from light, placed on it the phosphorescent substance, exposed the arrangement for some time to the direct sunlight, and finally developed the plate. Since X-rays were known to traverse the paper, the plate would be blackened if X-rays were produced. At first the results were negative. But when he used a sample of potassium uranyl disulphate K2UO2(SO4)22H2O, he observed an effect which he reported to the Academy on 24 February.

“A week later, on 2 March 1896, Becquerel reported again to the Academy. It is this report that contained the discovery which would make him famous. We first quote from a paragraph dealing with repetitions of his previous experiment:

A photographic plate, gelatine with silver bromide, was enclosed in an opaque frame in black cloth, closed on one side by a sheet of aluminium; if one exposed the frame in full sunshine, even for a whole day, the plate was not fogged; but, if one had fixed on the aluminium sheet, on the outside, a lamella of uranium salt [...] and if one exposed it for several hours to the sun, one recognised, after one had developed the plate in the usual way, that the silhouette of the crystalline lamella appeared in black on the sensitive plate.

“The unexpected discovery is described two paragraphs further down:

I shall insist in particular on the following fact which seems to me very important and outside the phenomena one could expect to observe: The same crystalline lamellas, placed with respect to photographic plates in the same way [...] but kept in the dark, produce again the same photographic prints. Here is how I have been led to make that observation: Of the previous experiments some had been prepared on Wednesday 26th and on Thursday 27th of February and, since on these days the sun had shown itself only intermittently, I had kept the experiments prepared and placed the frames back in the dark into a drawer, leaving the lamellas of uranium salt in place. Since the sun had also not shown itself the following days, I developed the plates, expecting to find very feeble images. The silhouettes appeared, on the contrary, with great intensity.

“Becquerel then went on to describe how he repeated experiments in complete darkness with the same result. Thus besides X-rays (or Röntgen rays) there was yet another kind of new rays, which were emitted seemingly without cause by a certain phosphorescent substance although that substance had not been stimulated to phosphoresce.

“During the course of 1896 Becquerel continued to investigate these rays. Still in March he found that they discharge an electroscope, i.e., they give some electric conductivity to air. He also performed observations, which later turned out to be erroneous, namely, that the rays could be reflected, refracted, and could possess polarization. These erroneous findings seemed to attribute to Becquerel’s rays most of the properties of ordinary light; they seemed to be better understood than Röntgen rays. It can be assumed that for this reason there was little interest in them for the next two years. In May 1896, Becquerel found out that all uranium compounds, phosphorescent or not, which he had studied, emitted rays. He concluded that pure metallic uranium should show the strongest radiation and confirmed that hypothesis by experiment. Becquerel now called his rays uranic rays. At the end of 1896, he reported on the absorbing power of different materials with respect to his rays. Moreover, he stressed the fact that the source of energy, which makes uranium emit rays, was completely unknown.

“We can summarize the events of 1896 in Paris by stating that Becquerel discovered radioactivity. He found it to be a property of the element uranium. It could be detected photographically and electrically. An unknown source of energy had to exist to keep the radiation going” (Brandt, The Harvest of a Century, pp. 10-12).

“Marie Curie’s work, which attracted Becquerel’s attention, brought the Curies within the circle of his acquaintance and turned him back to radioactive studies. He became the intermediary through whom their papers reached the Academy, and they lent him radium preparations from time to time. Toward the end of 1899 (his first report is dated 11 December), he began to investigate the effects on the radiation from radium of magnetic fields in various orientations to the direction of its propagation (in modern terms, the magnetic deflection of the beta rays from short-term decay products in equilibrium with the radium). In this work he united two descriptive traditions, the magneto optics of his own experience and a line of qualitative studies of the discharge of electricity through gases. He soon moved from these to J. J. Thomson’s more radical program of quantitative observations on collimated beams, in which Thomson had shown (1897) that the cathode rays were corpuscular and consisted of streams of swiftly moving, negatively charged particles whose masses were probably subatomic. By 26 March 1900, Becquerel had duplicated those experiments for the radium radiation and had shown that it too consisted of negatively charged ions, moving at 1.6 × 1010 cm./sec. with a ratio of m/e = 10-7 gm./abcoul. Thus Thomson’s ‘corpuscles’ (electrons) constituted a part of the radiations of radioactivity.

“At this period an idea was current, although seldom formally expressed, that radioactivity should be a property only of rare substances like radium, and not of ordinary chemical elements. Perhaps under the impulse of such a notion, Becquerel undertook to remove from uranium a magnetically deviable (or beta) radiation he had recently identified. His method was borrowed from André Debierne, who had found it effective with actinium. To a solution of uranium chloride, he added barium chloride and precipitated the barium as the sulfate. The precipitate entrained something, for the deviable radiation of the uranium was diminished; by a long repetition of such operations he succeeded in July 1900 in reducing that radiation, in one specimen, to one-sixth of its original value. In confirmation of this result, he found that earlier that spring, Crookes had succeeded, by more effective chemical procedures, in separating from uranium the photographically active radiation, which he now attributed to a substance provisionally named uranium X. Something over a year later, Becquerel realized the logical incongruity of these two successes. It had been relatively easy to remove the apparent radioactivity from uranium by chemical purification, yet no one who had investigated uranium over the last five years had ever observed a nonradioactive specimen. It followed, then, that whatever radioactivity was lost in purification must always regenerate itself; and he verified this logical conclusion on his own earlier specimens. The uranium had regained its lost radioactivity, and the barium sulfate precipitates had lost all that they had carried down. The explanations he attempted were thoroughly confusing, but the facts remained.

“These facts were brought squarely to the attention of Ernest Rutherford and Frederick Soddy, who had just succeeded in separating a thorium X analogous to Crookes’s uranium X. Their subsequent tests showed a similar regeneration of the lost radioactivity of the thorium. From this they inferred, and immediately verified, a regeneration of the thorium X in those specimens and then came to realize that this chemically distinct thorium X could have been formed there only by a transformation of the thorium. On the basis of these and similar experiments, in a few months they formulated the transformation theory, which became the basic theory of radioactivity” (DSB).

Becquerel’s memoir appeared in two forms: as Volume 46 of the Mémoires de l'Académie des Sciences de l'Institut de France, with title-page reading “Memoires . . . Tome quarante-sixieme,” and as a separate publication with title reading “Recherches sur une Propriété nouvelle de la Matière.” The journal article is further distinguished from the separate publication by the presence of “T. XLVI” in addition to the signature number on the first leaf of each signature.

Dibner, Heralds of Science 163; Norman 159; PMM 393; Sparrow, Milestones of Science, p. 46 and plate 201 (“As a result of his experiments described in Recherches sur une Propriété nouvelle de la Matière (1903), Becquerel discovered the principle of radioactivity”).

4to (285 x 230 mm), pp. [iv], [1], 2-360, [4, errata & explanation of the plates], with 71 photographic figures on 13 plates. Original printed wrappers.

Item #6153

Price: $9,500.00