Bava Metzia 30: Taking Care with Others' Stuff

Found items of different materials - silver, copper, wood, and so on - can be used by the finder in different ways, depending on the substance. Plus, when can a finder disregard the lost item? Also, the sages' discussion of acting beyond the letter of the law, and why people should do so. Plus, relevance for agunot. Also, a new mishnah - with animals who have moved out of their usual spaces.