[Trisquel-users] Is there a shut down log, and where can I find it ?

[amenex]

Often, when I shut down or restart Trisquel 7 in my Lenovo T420, a message  
very briefly appears (more properly, blinks) on my screen as white text on a  
black background just before the screen goes blank. It's impossible to read  
it or to photograph it.

Where might I find that message in the system logs, and what name would I  
expect to be used to describe such a log ?

I have installed ksystemlog.