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In the first quarter of the nineteenth century the experimental proof for the interdependence of the composition and properties of chemical compounds resulted in the theory that they are mutually related, so that like composition governs like properties, and conversely.
十九世纪上半叶，化合物的组成和性质相互依赖的实验证明，产生了这样一种理论:它们是相互关联的，因此相似的组成决定相似的性质，反之亦然。