He was unable to gain general acceptance of his doctrine of elements; and, strangely enough, the theory which next dominated chemical thought was an alchemical invention, and lacked the lucidity and perspicuity of Boyle's views.
From the Alexandrians the science passed to the Arabs, who made discoveries and improved various methods of separating substances, and afterwards, from the 11th century, became seated in Europe, where the alchemical doctrines were assiduously studied until the 15th and 16th centuries.
Have been some doubt as to the exact nature and import of the alchemical doctrines.
Antimony and its compounds formed the subject of an elaborate treatise ascribed to this last writer, who also contributed to our knowledge of the compounds of zinc, bismuth and arsenic. All the commonly occurring elements and compounds appear to have received notice by the alchemists; but the writings assigned to the alchemical period are generally so vague and indefinite that it is difficult to determine the true value of the results obtained.
Paracelsus (London, 1887); Schubert and Sudhoff, Paracelsus-Forschungen (Frankfurt a.M., 1887-1889); Sudhoff, Versuch einer Kritik der Echtheit der Paracelsischen Schriften (Berlin, 1894); Waite, The Hermetic and Alchemical Writings of Paracelsus (London, 1894).
The history of the alchemical period is treated in more detail in the article Alchemy, and of the iatrochemical in the article Medicine.
And Boniface 1 The alchemical works ascribed to Lull, such as Testamentum, Codicillus seu Testamentum and Experimenta, are of early although uncertain date.
As an outcome of this alchemical doctrine the process of fermentation was supposed to have a purifying and elevating effect on the bodies which had been submitted to its influence.
The great puzzle connected with the name Geber lies in the character of the writings attributed to him, their style and matter differentiating them strongly from those of even the best authors of the later alchemical period, and making it difficult to account for their existence at all.
Was primarily based upon certain experiments on combustion and calcination, and in effect reduced the number of the alchemical principles, while setting up a new one, a principle of combustibility, named phlogiston (from (PXoyun-6s, burnt).