Tolman, Hygiene for the Worker. American Book Company.
reports, etc.
American Health Magazine.
Annual Report of Department of Health, City of New York (and other cities).
Bulletins and Publications of Committee of One Hundred on National Health.
School Hygiene, American School Hygiene Association.
Grinnell, Our Army versus a Bacillus. National Geographic Magazine.
XXV. SOME GREAT NAMES IN BIOLOGY
If we were to attempt to group the names associated with the study of biology, we would find that in a general way they were connected either with discoveries of a purely scientific nature or with the benefiting of man's condition by the application of the purely scientific discoveries. The first group are necessary in a science in order that the second group may apply their work. It was necessary for men like Charles Darwin or Gregor Mendel to prove their theories before men like Luther Burbank or any of the men now working in the Department of Agriculture could benefit mankind by growing new varieties of plants. The discovery of scientific truths must be achieved before the men of modern medicine can apply these great truths to the cure or prevention of disease. Since we are most interested in discoveries which touch directly upon human life, the men of whom this chapter treats will be those who, directly or indirectly, have benefited mankind.
The Discoverers of Living Matter.—The names of a number of men living at different periods are associated with our first knowledge of cells. About the middle of the seventeenth century microscopes came into use. Through their use plant cells were first described and pictured as hollow boxes or "cells." But it was not until 1838 that two German friends, Schleiden and Schwann by name, working on plants and animals, discovered that both of these forms of life contained a jellylike substance that later came to be called protoplasm. Another German named Max Schultz in 1861 gave the name protoplasm to all living matter, and a little later still Professor Huxley, a famous Englishman, friend and champion of Charles Darwin, called attention to the physical and chemical qualities of protoplasm so that it came to be known as the chemical and physical basis of life.