There is a sad story detailed in the Newhampton Road Wesleyan Church Roll of Honour about a Corporal J. Newton Williams of the Royal Welsh Fusiliers (number 266790), as follows:
While training in Southern Ireland he was in involved in an accident which broke his leg. After a long spell of hospital treatment involving six operations he died in Blackrock Hospital 19/04/1919
The only corroboration of this information is his entry on the Commonwealth War Graves Commission site, which includes the fact that he is buried at Beaumaris Cemetery on Anglesey.
Without a first name, I have not been able to find out any further information on this man, including finding his birth records or being able to find him on census returns. I have also not been able to find a medal card for him at the National Archives under his service number, although he might possibly be this man, Newton Williams. If anybody can supply any further information on this man, please get in touch!