An argument for a mathematics program that is more compatible with the nature of the learner is therefore an argument for a greater degree of involvement with manipulative materials and exploitation of appropriate mathematical applications.
The Germ theory of disease, developed in the 1860s and 1870s by Louis Pasteur, states that tiny living beings are the cause of infectious diseases. The theory was developed to explain puerperal fever, or Child bed fever.
Alexander Fleming was an accomplished doctor even before his work with bacteria he even discovered that lysozyme, an enzyme that is present in body fluids such as saliva and tears, had a mild antiseptic effect. In the 19th century, several scientists contributed to the current understanding of the germ theory.