"on the mode of communication of cholera" was a scientific text written by dr. john snow in 1855 about the disease cholera. what are the two primary purposes of this text?

What is the rhyme scheme in this excerpt from longfellow's, "the tide rises, the tide falls? " (10 points) the tide rises, the tide falls, the twilight darkens, the curlew calls; along the sea-sands damp and brown the traveler hastens toward the town, and the tide rises, the tide falls.