Scrounger

From BioShock Wiki

Scrounger is a physical tonic which allows the user to search containers and corpses a second time, yielding different loot. If the user chooses to search again the loot may be worse than the initial search. The user may not then go back and choose to take the initial search results. For that reason, it should be used preferably when the initial search comes up blank or with loot the player doesn't need. Another use for this Gene tonic is when searching for specific ingredients for inventing an item and and unwanted ingredient comes up the first time.

[edit] Game Caption

Splicing Scrounger is like having a sixth sense. You'll spot things you'd otherwise miss and discover things you'd otherwise leave behind. With Scrounger, you'll swear you have X-Ray Vision!

[edit] Location

Receive at research level two for Leadhead Splicers.