Chapter 7: Theory of the Four Elements
At the age of 12 he rejected the theory of Four Elements of Aristotle and proved that it is wrong. He remarked : "I wonder how a man like Aristotle could say that in the world there are only four elements - Earth, Water, Fire, and Air. The Earth is not an element. It contains many elements. Each metal, which is in the earth, is an element.
For 1,000 years this theory was never refuted, and remained the corner stone of physics. Imam Jafar al-Sadiq (A.S) proved that Water, Air, and Fire were also not elements, but a mixture of elements. This he said 1,100 years before the European scientists discovered that air was not an element and had separated its constituents. To derive the fact that Air is not an element, but a mixture of elements, was impossible to conclude in the Imam's age and time. He said that there are many elements in the air and that all of them are essential for breathing.
It was only in the 18th century, which was considered the golden age of science, after Lavoisier separated oxygen from the air and demonstrated the important role it plays in breathing and combustion that they accepted that it is not an element. However, even then they were of the opinion that other elements do not play a part in breathing. In the middle of the 19th century scientists changed their views about the part played by other elements in breathing. By that time it was also proved that although oxygen purifies blood, it also burns combustible materials, which come in contact with it. If living beings breath pure oxygen for a long time, their breathing organs would be oxidised. Oxygen does not damage them because it is mixed with other gases. Therefore, they concluded that the presence of other gases which are in very minute quantities in the air is also essential for breathing.
Moreover, oxygen being the heaviest of all other gases in the air would have settled at the bottom and covered the surface of the earth up to a certain depth. As a result, breathing organs of all animals would have been burnt and animal life would have become extinct. Moreover it would have cut off the supply of carbon dioxide, which plants need so badly, and made it impossible for them to grow on the surface of the earth. Presence of other gases in the air does not let oxygen settle down to the bottom and destroy animal and plant life.
At last, after more than 1000 years, the theory of Jafar al-Sadiq (A.S) that presence of all gases in the air is essential for breathing was proved to be correct. He was the first person to discover that oxygen produces acidity.
Time did not allow him to make known to the world further such revelations, but he was indeed proved the pioneer and leader in the scientific study of oxygen.