I expect you have found this information:
NAME: Bonham Carter Walter Henry
BIRTH/BAPTISM: 11/08/1866
DEATH/BURIAL:
FATHER: Henry Bonham Carter
MOTHER: Sibella Charlotte Norman
MARRIAGES: 21/04/1898 Anita Florence Heuer
CHILDREN: David William
NOTES:
WC[369]
Solicitor 1890 practising at 4 Regents Street SW, [Messrs Thorold, Brodie & Bonham Carter.]
Secretary of the Nightingale Fund.
From this site:
http://freepages.genealogy.rootsweb.com/~thela mp/List%20of%20People%20for%20The%20NIGHTINGAL E%20FAMILY%20TREE.htm#Bonham%20Carter%20Walter %20Henry
But there are two leads - the name of the solicitors and the Nightingale Fund.
I also found this:
WALTER HENRY BONHAM CARTER b 11 AUG 1866 Paddington, Middlesex, d 9 Apr 1947 Died as result of a car accident, In 1881, attending Winchester College, Hampshire
From
http://www.geocities.com/layedwyer/smith.htm
Hope that helps a bit!