In the QSA rolls for the medical services, roll WO100-227 page 134 is simply titled "X Ray Expert".
There is just one name on the page: Eachus, Thomas Eedis.
The X-ray was a very recent discovery made by Conrad Rontgen in 1895. He immediately realised the X-ray could be useful in medicine. From 1896 medical doctors and scientists began developing the X-ray for doctors to use.
During the war both sides used x-ray machines. There are many hits on-line for "x-ray in the boer war", you can see a picture of an xX-ray machine in use here. Professor JC de Villiers wrote an overview article "The origins and early use of radiology in South Africa" which can be downloaded. However, TE Eachus' name does not figure in these sources or on-line searches connected with the war.
There is indeed a Thomas Eedis Eachus (1878-1931) who was not a doctor but an electrical engineer and I believe is the "X Ray Expert" although no direct evidence has been found to substantiate this. Known as Eedis, he was born in Sydenham, Kent in 1878, his father George Eedes was a civil engineer. Eedes was just 21 when war broke out in 1899. I have not traced his education, the last census before the war in 1891 he is a 13 year old scholar living in Forest Hill, south London. He does not appear to have gained any professional qualifications, nonetheless appears to have been a very competent and successful electrical engineer.
Eedis sailed for the war on 10 March, 1900 aboard SS Avoca with 10 General Hospital, he is described again as "X-ray Expert". He was perhaps working for a company that supplied X-ray machines and was sent out to maintain the machine. He worked in the Cape Colony, Orange Free State and Transvaal. The QSA roll is signed at 9 General Hospital, Bloemfontein in September, 1901. Eedis stayed on into 1902 as he earned a King's South Africa medal, his rank on this roll is "X-ray expert". How wonderful if that was inscribed on the medal.
Back in the UK, in December 1903 at the Enfield Church Day Schools Grand Bazaar he gave a "most attractive as well as instructive" presentation on the use of X-ray "in surgical operations, especially in relation to bullet wounds received in war"; something of which he had first hand knowledge. In 1905 he was granted a patent with a George Howard Nash for "Improvements in Cut-outs for Overhead Electrical Conductors." to make overhead trolley wires safer when they break. Eedes enjoyed sports, he played cricket for Enfield and was a member of the Bush Hill Park Golf Club, Winchmore Hill, London.
By 1911 Eedis is living in St Albans, Hertfordshire working for the Western Power Company. He later worked for the North Metropolitan Electric Power Supply Company.
In February 1917 Eedes was commissioned Temporary Lieutenant in the Royal Naval Reserve for his electrical skills. In April 1918 he was put to work on hydrophone research and development. Again Eedes was working on new technology, the hydrophone had only been invented in 1914. Once more he was successful in his work and was awarded an OBE in 1919 for "carrying out pioneer work in connection in which his electrical knowledge was invaluable". His report in ADM-337/123/244 noted: "Possess tact and firmness. Has greatly helped development of the Special Trawler Flotillas attached to Southern Patrol Force."
In 1929 be became a Joint Managing Director of the newly formed Young Accumulator Company Ltd. The 1935 AGM reported success of the company's "Super Armoured Battery" for use in electric vehicles, the report noted the batteries could be re-charged overnight; sound familiar?
In June 1918 Eedes married Nancy Lilias Bayford, they had one son, George T Eachus who was killed serving in the Royal Navy in 1943.
Eedes died 11, August 1931 in East Molesey, Surrey.