Wiktionary
n. (context informal chemistry English) Any of the traditional methods and techniques of chemistry, especially those of analytical chemistry that use gravimetric analysis or volumetric analysis rather than spectroscopy.
Wikipedia
Wet chemistry is a form of analytical chemistry that uses classical methods such as observation to analyze materials. It is called wet chemistry since most analyzing is done in the liquid phase. Wet chemistry is also called bench chemistry since many tests are performed at lab benches. Wet chemistry is now rarely done manually except for demonstration purposes. This is due to technological advancements in the field of chemistry.
Usage examples of "wet chemistry".
He worked up a wet chemistry method, and the test kits are in the car we came here in.
If I were wrong, doubt would be raised about in-space biological testing, with suspicion transferred to other forms of wet chemistry in microgravity.