This book traces a pivotal path in the history of physics, from gas physics to the birth of statistical mechanics. It begins with foundational studies by Torricelli, Pascal, and Boyle, then moves to atomic theory and the periodic table. A key focus is the 18th-century development of analytical mechanics, from Newton’s Principia (1687) to Lagrange’s Mécanique Analytique (1788). During this period, figures like Leibniz, the Bernoullis, Euler, d'Alembert, and Laplace helped refine the mathematical language of physics.

The book then explores the principle of energy conservation, following the debate on vis viva to Helmholtz’s unifying work. It also examines the establishment of the second law of thermodynamics, from early heat engine studies to the breakthroughs of Carnot and Clausius. The final section delves into the origins of statistical mechanics, beginning with Bernoulli’s kinetic theory of gases, progressing through Clausius and Maxwell, and culminating in Boltzmann’s transition to statistical mechanics, later refined by Gibbs.

A key feature of this volume is its use of primary sources, offering diverse perspectives on the works of these pioneers. It integrates extensive secondary literature, combining established studies with contemporary scholarship to provide a thorough historical account.

Luiz Roberto Evangelista is a Professor of Physics in the Department of Physics at Universidade Estadual de Maringá (Paraná, Brazil). He received his Ph.D. in theoretical physics (field theory and particle physics) from the University of São Paulo, Brazil, in 1988. His research interests include complex fluids, complex systems, and the history of physics, with a focus on the mathematical physics of liquid crystals, normal and anomalous diffusion, adsorption-desorption phenomena, and modern boundary value problems, particularly in applications to liquid-crystalline systems and impedance spectroscopy. He is the author of several books on the history of physics, on the elasticity of liquid crystals, and fractional calculus applied to anomalous diffusion phenomena, including the more recent "Fractional Diffusion Equations and Anomalous Diffusion" (Cambridge University Press, 2018) and "An Introduction to Anomalous Diffusion and Relaxation" (Springer-Nature, 2023).