Question

Information about discovery of gases and respiration

Answer 1

The beginning of accurate knowledge concerning the physiology of breathing dates back to the 17th century. Before that time, the ideas if vogue about why and how we breathe were as mystical and strange as the conception of the circulation were paradoxical. As a matter of course, the latter directly influenced the former, as we shall see. Hippocrates “counted air as an instrument of the body,” just as food eaten was. Galen, whose influence on medical thought and progress was so tremendous and devastating for many centuries, enunciated the doctrine, which held away until observation began to replace speculation. In the Galenic Doctrine, the movements of respiration served a triple purpose:

                        First:      The air introduced by breathing served to cool and to regulate the innate
                                      heat of the heart; that fire which placed there at the beginning continued there all life long,
                                      and was the one source of the warmth of the body.

Second:  The pumping action of the chest served to introduce into the blood the air, which was necessary 
                          for the generation in the left side of the heart of the vital spirits, which were thence distributed over 
                          the body by the arteries.

Third:    The same action served to get rid of the friligimous, the products of the innate fire burning in the heart. Both
                         the pure air engendering the vital spirits and the foul vapors, the effect of the hearts labors, were supposed to
                         pass by the vein-like artery, the pulmonary vein, the one, one way, the other the other; while blood was
                         supposed to pass trough minute pores in the septum of the heart from the right to the left side, while the vital
                         spirits passed through the same channels in the contrary direction.