http://www.1914-1918.net/royalscots.htm  nice booklet available
UK, Soldiers Died in the Great War, 1914-1919 <http://www.ancestry.com/search/db.aspx?dbid=1543&enc=1> 
about David Mitchell Tomlinson 
Name:   David Mitchell Tomlinson   
Death Date:   13 May 1916   
Rank:   Major (T)   
Regiment:   Royal Scots (Lothian Regiment)   
Battalion:   13th Battalion   
Type of Casualty:   Died of wounds
13th battalion Formed at Edinburgh, September 
1914, as part of K2. Moved to Aldershot.
September 1914 : attached to 45th 
Brigade, 15th (Scottish) Division.
Went to billets in Bramshott November 
1914, then Basingstoke February 1915 and on to Chisledon in March.
Landed in France July 1915.
lots of references to the unit and battalions online.
Anyone with a loved one on the CGCW can order a memorial or grave photo for around 5 pounds, all goes to their mission to maintain the graveswordwide. Do you know who has his medals and "dead man's penny"? 
HOPE this helps,
Mary in Oregon (powrie hstorian)