What was the reaction of the soldiers to the senseless massacre at the Somme? Did morale drop significantly? Was the butchery communicated to other units across the western front?

As for the reaction in morale along the front, I know of no other postings here. For the "senseless massacre" allegation, I know of a couple of good articles.

You might like to read this from the FAQ section on "Trench Warfare": "World War I question: large-scale offensives like Verdun and the Somme; fruitlessly wasteful or painful but necessary and even productive?" by /u/DuxBelisarius .

There used to be a poster elos_ with a lot of very valuable World War I answers, but they deleted their account. Luckily, their AskHistorians profile remains. Under '"Stupid Generals"/Lions led by Donkeys/Other' is another valuable posting: "Did General Haig Make a Good Choice By fighting the Battle of the Somme?" .

This is not to discourage discussion, especially not on the question of morale. More questions, data, and debate are welcome.