Possible Clues:

• Did the learned man give away this? No, he swallowed it (6)
• Give charitably - say blood
• Give - present
• Give as a gift as to charity
• Visit a bloodmobile, e.g.
• Do philanthropic work
• The man of learning swallowed this for the present
• Give as gift, say blood
• As there's no give in it, the professor took it as a matter of course
• Give (eg to charity)