"The dogma of the indestructibility of matter is one of the very few which modern has received from ancient science without alteration. From the great Roman poet, Lucretius, who made it the fundamental element of his philosophical system, down to the immortal Lavoisier, who established it on bases considered eternal, this sacred dogma was never touched, and no one ever sought to question it." [THE THEORY OF INTRA-ATOMIC ENERGY AND THE PASSING-AWAY OF MATTER.]
"It will be Dr. Le Bon's title to fame that he was the first to attack the dogma of the indestructibility of matter, and that he has destroyed it within the space of a few years. In 1896 he published a short note which will mark one of the most important dates in the history of science, for it has been the starting-point of the discovery of the dissociation of matter." [The Evolution of Matter, page 33]
See Also
indestructibility of mass
Law of the Permanence of the Properties of Matter
PERMANENCE OF FORM AND MATTER