1873 he started to keep a notebook, including gardening notes from the Dell entitled '1873 Calendar of flowering plants at the Dell'. These are now part of the Wallace collection at the Natural History Museum. While living at the Dell, Wallace continued to correspond with Darwin. He also took an interest in topics such as social reform and spiritualism, which latter, particularly, was to lead him into difficulties with the mainstream of the scientific establishment. Unfortunately, Wallace’s young son died and the family stayed in the Dell for only four and a half years. He lived in several places after Grays. The Dell after Wallace Wallace left the Dell in 1876 and the house was sold. The sale particulars describe it as having views that "would well repay a visit". At that time the "unusually attractive" grounds included a fountain and a croquet lawn as well as winding walks and terrace. The house was bought by William Winch Hughes, founder of the Victoria Wine Company. The Dell survives as number 25 College Avenue and is now a Grade II listed building with the date of construction prominently displayed. It was used as a convent by the Sisters of La Sainte-Union des Sacrés-Coeurs order of nuns who had founded the nearby Grays Convent High School. Some rooms in the Dell were used by the school's sixth form. On Saturday 14 September 2002, a green Thurrock Heritage plaque on the building was unveiled by Wallace's grandson Richard to commemorate Wallace's role in developing the theory of natural selection. In April 2013, the house was offered for sale at £1.5m and in 2015 the price was lowered to £700,000. The property was bought by the Navbridge Group and was converted into three flats. Notes Buildings and structures in Thurrock Houses completed in 1872