It's German. More likely Hier ruhet (here lies) Dr. Heinrich Zimmerman, probably starben or gestorben (died), April, date in roman numerals. alt (age) LIX (59) jahr (years), next part makes no sense but it would be a certain number of months probably 6, III t or tage (3 days). You'll have to figure out the roman numerals. I'm not good at that.