66Indian Journal of History of Science,INDIAN 52.1 JOURNAL (2017) 66-77 OF HISTORY OF SCIENCE DOI:10.16943/ijhs/2017/v52i1/41301 Discovery of X-rays and its Impact in India* S C Roy** (Received 05 June 2016) Abstract This paper presents some unknown or less known facts related to the discovery of X-rays. The impact that it made immediately after the discovery of X-rays in 1895, in the scientific community of India has also been presented. Keywords: Discovery of X-rays, J. C. Bose, Mahendra Lal Sircar, Roentgen, X-ray photograph. 1. INTRODUCTION discovery was made before the same Würzburg Society on January 23, 1896. According to the Wilhelm Conrad Roentgen (1845-1923) report published in the Münchener Medicinische has been credited with the discovery of X-rays Wochenschrift of January 29, 1896, the meeting and was awarded the first Nobel Prize in Physics was chaired by the famous anatomist Albert in 1901 based on this discovery. Roentgen’s Rudolf von Kolliker (1817-1905). After the lecture discovery is known to be the result of an accident Roentgen produced an X-ray picture of Kolliker’s while he was experimenting with a discharge tube. hand in a glass plate (Fig. 1). It was Dr. Kolliker The objective of the current article is to present who proposed that the new rays be known less known facts, such as that X-rays were henceforth as Roentgen rays (Grigg, 1965). produced experimentally much before Roentgen’s discovery in 1895 as has been found in literature and also to study the influence of this discovery on the scientific community of India. According to conventional scientific protocol, the date on which the paper has been first submitted for publication is considered as the date of the discovery. According to this, December 28, 1895 is considered as the date of discovery when Roentgen submitted his first “provisorial” communication Uebereineneue Art von Strahlen (On a New Kind of Rays) which was published in Fig.1. First X-ray picture made in public by Roentgen the Proceedings of the Würzburg Physico-Medical during his first oral presentation before the Würzburg Physico-Medical Society on January 23, Society (Sitzungber der WürzburgerPhysik.- 1896. The picture shows the hand of Albert Kolliker MedikGesellschaft). First oral presentation of the who chaired the talk. *The work has been performed under the sponsorship of a project: “History of X-ray Research in British India” by the Indian National Science Academy (INSA), New Delhi. **Indian Science News Association, 92 Acharya Prafulla Chandra Road, Kolkata 700009. E-mail:[email protected] DISCOVERY OF X-RAYS AND ITS IMPACT IN INDIA 67 Like Jagadis Chandra Bose who refused sometime in November 1895. As Bertha to take patent of his microwave discovery, mentioned in her letter, on one evening of Roentgen also refused to take patent of any part November 1895 she became angry with her of his discovery and rejected all commercial husband for the quality of food. In order to soothe proposals connected to this discovery. However, her, Roentgen took her downstairs to his laboratory unlike J.C. Bose he lost all his savings due to post and introduced her to the mysterious new rays. war inflation and suffered financial and other However, it was not mentioned whether her hand difficulties in the last years of his life. with a ring was exposed to this ray (Fig.2.) on the Roentgen’s discovery was shrouded with same day, but according to Edgar Ashworth mystery, stories and controversies which Underwood, Director of Wellcome Historical sometimes reached a stage of humiliation to the Museum the picture of his wife’s hand was taken great scientist. The discovery was accidental. As on November 8, 1895. This date was accepted by we all know, a screen in his laboratory began to Konrad Weiss, the historiographer of Austrian fluoresce even though the running Hittorf Roentgen Society and is accepted as the date of discharge tube (not Crookes tube) was covered the discovery. with dark paper. There is not much difference between Hittorf and Crookes discharge tube except that the vacuum is more in the latter. It is to be remembered in this connection that X-ray tubes that we are talking about were known as cold discharge tubes in which ionization of gas by high voltage was the source of electrons in contrast to modern X-ray tubes which contain a heated filament for producing electrons. It is believed that fluorescence was first noticed (Peh, 1995) by Roentgen’s laboratory assistant Ludwig Zhender in 1890, who while working with the discharge tube covered with black cloth observed the fluorescence in the Fig. 2. X-ray picture taken by Roentgen in 1895 of his wife fluorescent screen placed nearby. Although Bertha Ludwig’s hand. (Courtesy: Prof. Alok Zhender was loyal to Roentgen throughout his life Mukherjee of Jadavpur University, Kolkata) and had not claimed any recognition, but this story was severely distorted to humiliate Roentgen and 2. X-RAYS PRODUCED BEFORE ROENTGEN he was accused of stealing his Diener’s discovery There are evidences that X-rays had been (Grigg, 1965). The exact date of his discovery— produced experimentally before Roentgen’s date when he understood the importance of the in 1895. This is not surprising because the basic penetrating power of this new ray—is not known physical process to generate X-rays is the passage for sure. In accordance with Roentgen’s will all of electricity through gases which had been started his notes were destroyed after his death. From a studying in eighteenth century. Francis Hauksbee letter (Grigg, 1965) written by his wife Anna (estimated to be died in 1713) who was the Curator Bertha Ludwig to one of his cousins Mrs. L.R. of Experiments to the Royal Society, London Grauel of Indianapolis in March 1896, it was found described seeing ‘the shape and figure of all parts that Roentgen first noticed this new radiation 68 INDIAN JOURNAL OF HISTORY OF SCIENCE of his hand’ while working with electricity and However, the first recorded evidence to vacuum (Peh, 1995). Interest in the study of produce Roentgen rays was about hundred years discharge in gases was revived in the middle of before Roentgen by William Morgan (1750-1833), nineteenth century after Faraday’s experiments the Welsh mathematician and Chief Actuary with “radiant matter” and many scientists were of British Equitable Assurance Society. He involved in producing different improvised (Morgan, 1784) reported in the Philosophical discharge tubes to study discharge of gases. Transactions that based on the length of time for Heinrich Geissler, Johann Wilhelm Hittroff, and which mercury was boiled in vacuum—the Sir William Crookes were some of the people who ‘electric’ light turned violet, purple, then beautiful worked with discharge tubes and they had green and finally the light became invisible! His unknowingly exposed to X-rays while working. success was based on the use of an improved vacuum, made possible by ‘boiling mercury’ Interestingly, in 1879 William Crookes which was a method developed by a certain Walsh (1832-1919) produced X-rays when the vacuum (exact identity not known) (Grigg, 1965). Morgan of his discharge tube was high enough as he found also presented this discovery to the Royal Society the photographic plates stored near his work table in 1784 which was witnessed by Richard Price were fogged. Without knowing the real cause of and one of Richard’s friends an American fogging he blamed the manufacturer for supplying ‘electrician’, famous Benjamin Franklin (1706- ‘defective’ plates (Grigg, 1965). 1790)! Philipp Lenard (1862-1947) worked on cathode rays and it is believed that he was very 3. THE FIRST X-RAY ROENTGENOGRAPH: close to the discovery of X-rays. In fact both CLAIMS AND COUNTER-CLAIMS Lenard and Roentgen was nominated for the Nobel The first ‘shadow graph’ or Prize in Physics for the year 1901, and the ‘Roentgenograph’ of metal objects was obtained Committee recommended that the prize should be by accident in 1892 by a Philadelphia divided equally between Roentgen and Lenard. experimentalist Arthur Willis Goodspeed (1860- However, the Royal Academy of Science did not 1943). The story goes like that Bill Jennings was follow this recommendation and decided to award the prize to Roentgen alone. On October 12, 1892 counting his coins after the Bill Jennings’ Carfare Lenard had been able to show for the first time on the Woodland Avenue trolley when Goodspeed that cathode rays can penetrate the aluminium asked Jennings to help in photographing the spark window and can travel a few inches in air by gap of a Ruhmkorff coil. Jennings put his coins observing the fluorescence produced on granules on the top of a plate while assisting in the of potassium phosphate placed outside the tube positioning of the electrodes. The plate was later (Glasser, 1934). After about four years in 1905, found to have black patches. Rounded shadows the Nobel Committee decided to award the Nobel shown in Fig. 3 are the images of coins. They paid Prize to Lenard for his ingenious work on cathode little or no attention to those circular shadows till rays. Lenard, however, considered himself to be the announcement of Roentgen’s discovery was “the mother of X-rays” while Roentgen was “the made when they repeated the experiment and midwife who happened to deliver the child”. There understood the reason. However, Goodspeed are other scientists who are believed to have expressly and repeatedly denied any claims to observed X-rays before Roentgen and we are not priority because at that time he had failed to going into the details of those stories.