This moving artcle comes from the book On the King's Service Inward Glimpses of Men at Arms by Innes Logan.
Innes Logan was Chaplin to the Forces from September 1914 to May 1916. In the aftermath of the Battle of Loos in September 1915, he worked at a Casualty Clearing Station. Here he describes the wounded soldiers writing home to their loved ones.
“Every wounded man has a letter to write or to have written for him, and it was essential that since the people at home knew there was heavy fighting going on all messages should be sent off at once. This is one of the chaplain's voluntary tasks, and we were kept close to it every afternoon for some weeks after the offensive began. For some time the number of letters was about four hundred every day.
A number of men had written farewell letters—very moving they seemed, but I did not think it part of my duty to look too closely at these. They had addressed them and then put them in their pockets, hoping that if they were killed they might be discovered. Some had been finished just before the order to go over the parapet. But the curious thing was that these were sent home, with a few words in a covering note saying they were alive and well, as a sort of keepsake.
In those written after arrival in hospital a sense of gratitude to God was very frequent, and a great longing for home and the children. Some strange phrases were used: a mother would be addressed as 'Dear old face,' or simply 'Old face.' But poets used to write verses to their mistresses' eyebrows, and why not a letter to a mother's face?”