Book 39: Dirt. When Logan subtitles this book "the ecstatic skin of the earth" he means it in more of a reverential way. He's an arborist and nature writer who wrote this gentle collection of essays reflecting on what we know about the soil we stand on, farm in, and walk through. Some of it contains lessons in history, some is more straightforward soil science, all of it is interesting to read and will make you look more at the world around you when you're outdoors.