We have three editions of the Merck Index in our collection. Two are in our General collection (13th and 14th editions) and one is in our Reference collection (15th edition).
Students in CH 114 need to use the Merck Index for an assignment each semester. They must use the 13th or 14th editions, but not the 15th edition. In order to accommodate all the students in this class during this assignment, the librarians pull the Merck Index from the General collection and keep it at the 2nd floor circulation desk. Students need to come to the desk to obtain the Index they need to complete their assignment.