General physiology : an outline of the science of life / translated and edited by Frederic S. Lee.

  • Verworn, Max, 1863-1921.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: General physiology : an outline of the science of life / translated and edited by Frederic S. Lee. Source: Wellcome Collection.

Provider: This material has been provided by the Gerstein Science Information Centre at the University of Toronto, through the Medical Heritage Library. The original may be consulted at the Gerstein Science Information Centre, University of Toronto.

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    contributions to the physiology of the cell, and in our own time, from this side especially, the physiology of reproduction, fertili- sation, development, and heredity has been taken away from physiology proper, and developed into a fruitful and independent subject.1 The comparative method has not been employed in physiology since Johannes Miiller's time, unless the few researches that have been conducted upon other animals than the usual dogs, rabbits, and frogs are to be considered as comparative. Plant physiology, however, has developed quite independently into a nourishing science; and the distinguished labours of Hofmeister, Nageli, Sachs, Pfeffer, Strasburger, Berthold, and others have made this in recent times the most complete branch of physiology. This is due partly to the fact that all vital relations are much simpler and more easily surveyed in plants than in animals, and partly to the fact that plant physiology has made use of certain acquisitions of science that have thus far found little or no application to the physiology of animals. There are three of the greatest discoveries of this century, from the further expansion of which physiology is justified in still expecting great results. One of these is the law of the conservation of energy, which was definitely expressed by Robert Mayer (1814-1878), and was estab- lished most comprehensively by Helmholtz. Modern chemical investigations had led to a recognition of the law of the conservation of matter, by showing that the quantity of matter, of atoms, in the universe is constant, and that the smallest atom cannot by any agency be destroyed or recreated. The law of the conservation of energy expresses the same fixedness for the sum of the energy of the universe. Energy, like matter, can be neither destroyed nor recreated; when it seems to appear or disappear, it merely passes from one form into another. Among the recognised forms of energy two varieties are distinguished: energy of motion, or kinetic energy, when power is in action, i.e. is pro- ducing motion; and energy of position, or potential energy, when it is latent but under certain conditions can come into action. Thus, e.g., the potential energy that was produced in the Carboniferous age by transformation of the kinetic energy of the sun's rays through the activity of plants and was stored up as chemical affinity in vast strata of coal, passes over into heat upon combustion of the coal. The heat is transformed by steam engines which are heated by the coal, into the energy of 1 Rdsumes of what has been accomplished in this field are given by the following books: Die, Zelle und die Gewebe, by O. Hertwig (1892) [authorised English trans- lation, The Cell: Outlines of General Anatomy and Physiology, 1895]; Gesammelte Abhandlungen iiber EntwicUungsmechanik, by W-. Roux (1895); La structure du protoplasma et les theories sur Vheredite, etc., by Yves Delage (1895) ; [and The Cell in Development and Inheritance, by E. B. Wilson (1896)].