Germ theory that states that microorganisms, which are too small to be seen without the aid of a microscope, can invade the body and cause certain diseases. in the late 1800's this theory lead to a simple practice that saved thousands of lives in hospitals throughout the country from post-operative infections. this practice was

The practice that has been started because of the germ theory in which happened in the late 1800s was the introduction or proper hand washing in which was essential as the hands is the common route to infection because of the things that we touch and by that proper hand wash has been introduced and set as a practice in order to save thousands of lives.