عند إجراء التجارب، لا بد من تبسيطها قدر الإمكان، وإزالة كل ظرف قد يُعقّد النتائج إزالةً تامة.

“In performing experiments, it is necessary... that they be simplified as much as possible, and that every circumstance that could complicate the results should be completely removed.”Antoine Lavoisier