Source identified1
“I measure every grief I meet With analytic eyes; I wonder if it weighs like mine, Or has an easier size.”
Personal grief becomes a lens for noticing other people's suffering, with the speaker comparing losses while admitting that another person's burden cannot be known directly.
Source note: “Griefs,” Poems: Third Series (1896), Project Gutenberg #12242. The poem explores comparison and recognition of suffering rather than offering a clinical scale for grief.