You should do me like this

SELECT * FROM gallery2 WHERE topic_id="885814" UNION SELECT * FROM gallery2 WHERE topic_id="1687525" UNION SELECT * FROM gallery2 WHERE topic_id="810914" UNION SELECT * FROM gallery2 WHERE topic_id="1825637" UNION SELECT * FROM gallery2 WHERE topic_id="1581592" UNION SELECT * FROM gallery2 WHERE topic_id="393804" UNION SELECT * FROM gallery2 WHERE topic_id="699672" UNION SELECT * FROM gallery2 WHERE topic_id="1299841" UNION SELECT * FROM gallery2 WHERE topic_id="199228" UNION SELECT * FROM gallery2 WHERE topic_id="732688" UNION SELECT * FROM gallery2 WHERE topic_id="1055854" UNION SELECT * FROM gallery2 WHERE topic_id="2243" UNION SELECT * FROM gallery2 WHERE topic_id="1744923" UNION SELECT * FROM gallery2 WHERE topic_id="1401165" UNION SELECT * FROM gallery2 WHERE topic_id="1174230" UNION SELECT * FROM gallery2 WHERE topic_id="316658"