一 門捷列夫週期系辯證地反映了自然“與形而上學相反,辯證法不是把自然界看作什麽彼此隔離,彼此孤立,彼此不相依賴的各個對象或各個现象底偶然堆積,而是把它看作有內在聯系的統一整體,其中各個對象或各個現象是互相密切聯系着,互相依賴着,互相制約着的。”(斯大林)自然界中一切物質的化學結構單元是元素,例如氫、氧、碳、鐵等等。在1661年波義耳確立了化學元素這一概念以後,科學家在整整一個半世紀中把這些多種多樣的元素看作彼此間隔離、孤立、不相依賴的各個對象底偶然堆 A Mendeleev’s cycle dialectically reflects nature as "contrary to metaphysics, dialectics does not see nature as accidental accumulation of objects or phenomena that are isolated from each other, isolated from each other, and from each other, (Stalin) The chemical structure unit of all matter in nature is elements, such as hydrogen, oxygen, carbon, iron and many more. After Boyle established the concept of chemical elements in 1661, scientists saw these various elements for as long as a century after they were isolated, isolated and not dependent on each other.