History of Chemistry, Volume 2 (of 2): From 1850 to 1910

In Short

History of Chemistry, Volume 2 by T. E. Thorpe chronicles the advancements in chemistry from 1850 to 1910. It highlights the work of prominent chemists like Liebig, Wöhler, Dumas, and Bunsen, and their contributions to organic and inorganic chemistry. The book explores the development of theories such as the doctrine of chemical atoms, the periodic law, and the discovery of elements like cæsium, rubidium, and argon. It also delves into the emergence of radioactivity, the study of molecular weights, and the application of spectroscopy. This volume provides a detailed account of the scientific breakthroughs and methodologies that laid the foundation for modern chemistry.

The Story

History of Chemistry, Volume 2 picks up where the first volume left off, beginning in 1850 and continuing through 1910. The narrative unfolds as a series of interconnected discoveries and innovations that collectively advanced the field of chemistry. The book opens with the collaborative work of Justus von Liebig and Friedrich Wöhler, whose investigations into organic compounds and the synthesis of urea marked a turning point in understanding the relationship between organic and inorganic chemistry. Wöhler's synthesis of urea from inorganic materials challenged the prevailing vitalism theory, demonstrating that organic compounds could be created from inorganic sources.

The story then shifts to the contributions of Jean-Baptiste Dumas in France, whose students, including Boullay, Piria, and Wurtz, played pivotal roles in expanding organic chemistry. Dumas's influence is contrasted with Liebig's, highlighting the global nature of scientific progress during this period. The book also explores the work of Robert Bunsen, known for his improvements in analytical chemistry and the invention of the Bunsen burner, which became an essential tool in laboratories worldwide.

A significant portion of the narrative is dedicated to the development of atomic theory and the periodic law. The book discusses the work of John Dalton and how his atomic theory was refined by later chemists, including Graham and Kekulé. The periodic law, formulated by Dmitri Mendeleev, is presented as a unifying principle that organized the elements based on their atomic weights and properties. This law not only explained existing observations but also predicted the existence of undiscovered elements, such as gallium and germanium.

The discovery of new elements and their properties is a recurring theme. Bunsen's application of spectroscopy led to the identification of cæsium and rubidium, while Lord Rayleigh and William Ramsay's work on the density of nitrogen gas resulted in the discovery of argon, the first noble gas. These findings expanded the periodic table and deepened understanding of atomic structure.

The book also delves into the emergence of radioactivity, a phenomenon first observed by Henri Becquerel and further explored by Marie and Pierre Curie. The Curies' discovery of radium and polonium, along with Rutherford's research on radioactive decay, laid the groundwork for nuclear chemistry. The concept of half-life and the transformation of elements through radioactive decay are explained, revealing the dynamic nature of atomic matter.

Another key area of focus is the determination of molecular weights and the study of solutions. The book discusses the methods developed by Raoult and others to measure molecular weights using freezing-point depression and boiling-point elevation. These techniques provided precise ways to determine the molecular structures of compounds, essential for understanding chemical reactions.

The narrative concludes with an exploration of stereochemistry and the work of van 't Hoff and Le Bel, who introduced the concept of chirality and the spatial arrangement of atoms in molecules. This breakthrough explained the existence of enantiomers and their different properties, a fundamental aspect of modern chemistry.

Throughout, the book emphasizes the interconnectedness of these discoveries and the collaborative nature of scientific progress. It highlights how each advancement built upon previous work, creating a cumulative body of knowledge that transformed chemistry into a rigorous and predictive science.

How It Unfolds

The Liebig-Wöhler Collaboration: The book begins by detailing the partnership between Liebig and Wöhler, whose work on organic compounds and the synthesis of urea challenged the vitalism theory and laid the foundation for organic chemistry.

Dumas's Influence in France: The narrative shifts to Dumas's contributions and the impact of his students, who expanded organic chemistry and developed new methodologies.

Bunsen's Analytical Innovations: Bunsen's improvements in analytical chemistry, including the invention of the Bunsen burner and the application of spectroscopy, are highlighted as key advancements.

Atomic Theory and the Periodic Law: The book explores the refinement of atomic theory and the formulation of the periodic law, which organized the elements and predicted new ones.

Discovery of New Elements: The identification of cæsium, rubidium, and argon through spectroscopy and gas density studies expanded the periodic table and deepened understanding of atomic structure.

Emergence of Radioactivity: The discovery of radioactivity by Becquerel and the Curies, along with Rutherford's research, introduced a new field of study and revealed the dynamic nature of atoms.

Molecular Weights and Solutions: The development of methods to determine molecular weights and study solutions provided precise tools for understanding chemical structures and reactions.

Stereochemistry: The work of van 't Hoff and Le Bel on chirality and molecular spatial arrangements explained the existence of enantiomers and their properties.

The People

Justus von Liebig: A pioneering chemist who collaborated with Wöhler and made significant contributions to organic chemistry, particularly in the study of organic compounds and their synthesis.

Friedrich Wöhler: Known for synthesizing urea from inorganic materials, Wöhler challenged the vitalism theory and demonstrated the interconnectedness of organic and inorganic chemistry.

Jean-Baptiste Dumas: A French chemist whose students played crucial roles in advancing organic chemistry, expanding its scope and methodologies.

Robert Bunsen: Famous for inventing the Bunsen burner and applying spectroscopy to discover new elements, Bunsen's work revolutionized analytical chemistry.

John Dalton: His atomic theory provided the foundational framework for understanding atomic structure, which was later refined by subsequent chemists.

Dmitri Mendeleev: Formulated the periodic law, organizing the elements based on atomic weights and properties, and predicted the existence of undiscovered elements.

Lord Rayleigh and William Ramsay: Their work on gas densities led to the discovery of argon, the first noble gas, expanding the periodic table.

Henri Becquerel, Marie Curie, and Pierre Curie: Pioneers in the study of radioactivity, their discoveries of radium and polonium laid the groundwork for nuclear chemistry.

Ernest Rutherford: His research on radioactive decay and atomic structure provided insights into the dynamic nature of atoms and their transformations.

Jacobus Henricus van 't Hoff and Joseph Achille Le Bel: Introduced the concept of chirality and stereochemistry, explaining the spatial arrangements of atoms in molecules and the existence of enantiomers.

In Its Own Voice

On the Synthesis of Urea:

Wöhler succeeded for the first time in preparing the metal aluminium and in effecting the synthesis of urea—one of the first organic compounds to be prepared from inorganic materials.

On the Periodic Law:

The periodic law, based as it is on the solid and wholesome ground of experimental research, has been evolved independently of any conception as to the nature of the elements.

On Radioactivity:

The rate of disintegration of radium is relatively slow; it has been calculated that the time required for half of any given quantity of radium to change completely into other products is about 2000 years.

What It's Really About

This book is fundamentally about the evolution of chemical knowledge and the methodologies that drove scientific progress in the 19th century. It explores how chemists built upon each other's work, often across national boundaries, to create a unified and predictive science. The themes of collaboration, experimentation, and theoretical innovation are central, as are the challenges of understanding atomic and molecular structures. The book also highlights the interplay between theory and practice, showing how new theories like the periodic law and atomic theory were tested and refined through experimental observations. Ultimately, it is a story of human curiosity and the relentless pursuit of understanding the natural world.

Why Read It Today

History of Chemistry, Volume 2 offers a detailed and engaging account of a transformative period in the history of science. Readers interested in the development of modern chemistry will find it fascinating to see how foundational concepts like atomic theory and the periodic law emerged and evolved. The book provides insights into the lives and minds of pioneering chemists, making their discoveries relatable and inspiring. While the language and some concepts may be challenging for those without a background in chemistry, the book's clear explanations and historical context make it accessible to dedicated readers. It is a valuable resource for understanding the roots of contemporary chemistry and the scientific method, offering a deeper appreciation for the discipline's complexity and beauty.