Use "placidness" in a sentence

1. And the thought of your letters with so little placidness about them, was with me this afternoon in that terrible house, and it added to the fear of the future that seized me by the throat and would not let me go

2. For some subtle reason the expression of extreme placidness on Ingeborg's face as she lay silently watching the tree-tops and planning what she would do with her baby annoyed the Baroness