Protoplasmic Theory Of Life

Author : Daniel Liu
Publisher :
ISBN 13 :
Total Pages : 304 pages
Book Rating : 4.:/5 (112 download)

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Download or read book Visions of Life and Matter written by Daniel Liu and published by . This book was released on 2016 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a century, anyone with sympathies towards materialism and reductionism in biology could say that most important stuff in a living organism was [protoplasm], often referred to as "living matter" and the "physical basis of life." By examining the confluence of biology's material and visual cultures of the cell, this dissertation seeks to open the "black box" of the physico-chemical, materialist conception of life as protoplasm. The dissertation argues that the material and ontological foundations of biology changed twice during the century of protoplasm, from the 1840s to the 1930s. The first major change began in 1899, when protoplasm became defined as a colloid - a heterogeneous aggregate whose structure and behavior came from a delicate balance of thermodynamic interactions of their material phases, rather than an assembly of individual molecules. Through colloid chemistry biologists became suspicious of arguments about definite molecular structures in the soft, vital parts of living organisms - and not just because of colloid chemistry's associations with nominalist, energy-centric physics. By the end of the nineteenth century, many biologists had become skeptical of the chemical fixation techniques needed to see sub-cellular structures, and ordinary light microscopes had reached the limits of their theoretical resolving power. The second major change to protoplasm theory came to a head in the 1930s, as biologists sought to use indirect techniques to overcome microscopy's resolution limits, and to visually disaggregate colloids into their component parts. Crucially, these techniques required extensive use of diagrams and schematic illustrations to make visible a "biological microworld" of the molecular "ultrastructure" of cells, both in the imagination and on paper. The second half of the dissertation examines three pioneers in cell ultrastructure research, and their use of polarized light microscopy to create this biological microworld: Herman Ambronn, Albert Frey-Wyssling, and Wilhelm J. Schmidt. By investigating how biologists developed their own theories of living matter, this dissertation shows that they engaged with physics and physical chemistry decades before the post-war biophysics boom, and offers a new history of how biologists began to imagine and explore life at the molecular level.