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.
By the 1850s, people still didnât know exactly what caused disease. There were many theories, but none were based on scientific principles. In 1858, the German physician Rudolf Virchow offered the first clue with his cell theory. He said the cell, which Dutch inventor Antoni van Leeuwenhoek had seen 200 years earlier, was the basic unit of human life and that disease occurs when the function of cells is disrupted.