Did William Coggeshall Save Lincoln's Life?

[L Verge]

I made a posting early on about checking the history of hand grenades, and it seems to me that the CW era ones were thrown like a dart and had to land on their "noses" in order to explode. Another likelihood that the incident didn't occur. Has anyone found anything on the construction of grenades of that era to dispute it? Coal bombs worked on boats because they reacted to heat. What was the equivalent on land?