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Abū Rqayhān al-Bīrūnī (973 – 1048) sought to prove that Allah created a perfect universe, so he fudged the results to match the results he had expected.
His experiment consisted of heating liquid mercury until it turned into a red powder, and then weighing the powder expecting to confirm that its weight had not changed. He did not know that the red powder was mercury(II) oxide, and did not know that an oxide contains oxygen atoms, which increases its weight. Further heating decompose the red powder into vapors.
He and other Muslims who repeated his findings had no understanding of simple chemistry.
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Abū Rqayhān al-Bīrūnī (973 – 1048) sought to prove that Allah created a perfect universe, so he fudged the results to match the experimental results he had expected.
His experiment [perhaps copying from al-Majriti] consisted of heating liquid mercury until it turned into a red powder, and then weighing the powder expecting to confirm that its weight had not changed.
His scale could only weigh liquids and solids, not vapors. He did not know that the red powder was mercury(II) oxide, and did not even know what an oxide was.
If all of the mercury had converted into red powder, the weight would have increased by about 8%.
The red powder decomposes into mercury vapor and oxygen at a temperature of 500 degrees C. The flame in wood burning stoves under optimum conditions can reach 1980 degrees C, so his apparatus could likely reach the temperature needed to vaporize some of the red powder.
IGNORANCE OF SIMPLE CHEMISTRY
Since he was expecting the weight to stay the same, he fudged the results to show no change in weight, rather than investigating why the weight increased and decreased, as a modern scientist would have done. His method was the exact opposite of the “scientific method”.
Therefore, he failed to discover oxidation. He did not “prove” the law of conservation of mass in chemical reactions. He remained ignorant of proper scientific ways to conduct experiments, and remained ignorant of simple chemistry.
Al-Biruni took a large step backwards, understanding less about chemistry than what the ancient Egyptians had known. [In pre-Islamic times, the Egyptians knew that heating liquid mercury causes it to evaporate away, and used this knowledge in their fire-gilding method of evenly coating an object with a thin layer of gold. Those Egyptians probably also knew that heating liquid mercury to a lower temperature produces a powder.]
The en.wikipedia article on al-Majriti completely botches the explanation of the Mercury(II) oxide experiment.
AL-TUSI REPEATED THE BLUNDER
Al-Tusi (1201 – 1274) borrowed from al-Biruni’s writings about conservation of mass. “A body of matter cannot disappear completely. It only changes its form, condition, composition, colour and other properties and turns into a different complex or elementary matter.”
If al-Tusi actually performed the Mercury(II) oxide experiment, he botched it as badly as al-Biruni had done. Al-Tusi was as ignorant of simple chemistry as al-Biruni had been.
Image by Materialscientist (talk), via Wikimedia Commons.
image credit https://en.wikipedia.org/wiki/File:HgOpowder.jpg