The accounts which have come to us of the men who followed the pursuit of the One Thing are vague, scrappy, and confusing.

Alchemical books abound in quotations from the writings of Geber. Five hundred treatises were attributed to this man during the middle ages, yet we have no certain knowledge of his name, or of the time or place of his birth. Hoefer says he probably lived in the middle of the 8th century, was a native of Mesopotamia, and was named Djabar Al-Konfi. Waite calls him Abou Moussah Djafar al-Sofi. Some of the mediaeval adepts spoke of him as the King of India, others called him a Prince of Persia. Most of the Arabian writers on alchemy and medicine, after the 9th century, refer to Geber as their master.

All the MSS. of writings attributed to Geber which have been examined are in Latin, but the library of Leyden is said to possess some works by him written in Arabic. These MSS. contain directions for preparing many metals, salts, acids, oils, etc., and for performing such operations as distillation, cupellation, dissolution, calcination, and the like.

Of the other Arabian alchemists, the most celebrated in the middle ages were Rhasis, Alfarabi, and Avicenna, who are supposed to have lived in the 9th and 10th centuries.

The following story of Alfarabi's powers is taken from Waite's Lives of the Alchemystical Philosophers: -

  "Alfarabi was returning from a pilgrimage to Mecca, when, passing 
  through Syria, he stopped at the Court of the Sultan, and entered 
  his presence, while he was surrounded by numerous sage persons, 
  who were discoursing with the monarch on the sciences. Alfarabi 
  ... presented himself in his travelling attire, and when the 
  Sultan desired he should be seated, with astonishing philosophical 
  freedom he planted himself at the end of the royal sofa. The 
  Prince, aghast at his boldness, called one of his officers, and in 
  a tongue generally unknown commanded him to eject the intruder. 
  The philosopher, however, promptly made answer in the same tongue: 
  'Oh, Lord, he who acts hastily is liable to hasty repentance.' The 
  Prince was equally astounded to find himself understood by the 
  stranger as by the manner in which the reply was given. Anxious to 
  know more of his guest he began to question him, and soon 
  discovered that he was acquainted with seventy languages. Problems 
  for discussion were then propounded to the philosophers, who had 
  witnessed the discourteous intrusion with considerable indignation 
  and disgust, but Alfarabi disputed with so much eloquence and 
  vivacity that he reduced all the doctors to silence, and they 
  began writing down his discourse. The Sultan then ordered his 
  musicians to perform for the diversion of the company. When they 
  struck up, the philosopher accompanied them on a lute with such 
  infinite grace and tenderness that he elicited the unmeasured 
  admiration of the whole distinguished assembly. At the request of 
  the Sultan he produced a piece of his own composing, sang it, and 
  accompanied it with great force and spirit to the delight of all 
  his hearers. The air was so sprightly that even the gravest 
  philosopher could not resist dancing, but by another tune he as 
  easily melted them to tears, and then by a soft unobtrusive melody 
  he lulled the whole company to sleep."

The most remarkable of the alchemists was he who is generally known as Paracelsus. He was born about 1493, and died about 1540. It is probable that the place of his birth was Einsiedeln, near Zurich. He claimed relationship with the noble family of Bombast von Hohenheim; but some of his biographers doubt whether he really was connected with that family. His name, or at any rate the name by which he was known, was Aureolus Philippus Theophrastus Bombast von Hohenheim. His father in alchemy, Trimethius, Abbot of Spannheim and then of Wurzburg, who was a theologian, a poet, an astronomer, and a necromancer, named him Paracelsus; this name is taken by some to be a kind of Graeco-Latin paraphrase of von Hohenheim (of high lineage), and to mean "belonging to a lofty place"; others say it signifies "greater than Celsus," who was a celebrated Latin writer on medicine of the 1st century. Paracelsus studied at the University of Basle; but, getting into trouble with the authorities, he left the university, and for some years wandered over Europe, supporting himself, according to one account, by "psalm-singing, astrological productions, chiromantic soothsaying, and, it has been said, by necromantic practices." He may have got as far as Constantinople; as a rumour floated about that he received the Stone of Wisdom from an adept in that city. He returned to Basle, and in 1527 delivered lectures with the sanction of the Rector of the university. He made enemies of the physicians by abusing their custom of seeking knowledge only from ancient writers and not from nature; he annoyed the apothecaries by calling their tinctures, decoctions, and extracts, mere soup-messes; and he roused the ire of all learned people by delivering his lectures in German. He was attacked publicly and also anonymously. Of the pamphlets published against him he said, "These vile ribaldries would raise the ire of a turtle-dove." And Paracelsus was no turtle-dove. The following extract from (a translation of) the preface to The Book concerning the Tinctures of the Philosophers written against those Sophists born since the Deluge, shews that his style of writing was abusive, and his opinion of himself, to say the least, not very humble: -

  "From the middle of this age the Monarchy of all the Arts has been 
  at length derived and conferred on me, Theophrastus Paracelsus, 
  Prince of Philosophy and Medicine. For this purpose I have been 
  chosen by God to extinguish and blot out all the phantasies of 
  elaborate and false works, of delusive and presumptuous words, be 
  they the words of Aristotle, Galen, Avicenna, Mesva, or the 
  dogmas of any among their followers. My theory, proceeding as it 
  does from the light of Nature, can never, through its consistency, 
  pass away or be changed; but in the fifty-eighth year after its 
  millennium and a half it will then begin to flourish. The practice 
  at the same time following upon the theory will be proved by 
  wonderful and incredible signs, so as to be open to mechanics and 
  common people, and they will thoroughly understand how firm and 
  immovable is that Paracelsic Art against the triflings of the 
  Sophists; though meanwhile that sophistical science has to have 
  its ineptitude propped up and fortified by papal and imperial 
  privileges.... So then, you wormy and lousy Sophist, since you 
  deem the monarch of Arcana a mere ignorant, fatuous, and prodigal 
  quack, now, in this mid age, I determine in my present treatise to 
  disclose the honourable course of procedure in these matters, the 
  virtues and preparation of the celebrated Tincture of the 
  Philosophers for the use and honour of all who love the truth, and 
  in order that all who despise the true arts may be reduced to 

The turbulent and restless spirit of Paracelsus brought him into open conflict with the authorities of Basle. He fled from that town in 1528, and after many wanderings, he found rest at Salzburg, under the protection of the archbishop. He died at Salzburg in 1541, in his forty-eighth year.

The character and abilities of Paracelsus have been vastly praised by some, and inordinately abused by others. One author says of him: "He lived like a pig, looked like a drover, found his greatest enjoyment in the company of the most dissolute and lowest rabble, and throughout his glorious life he was generally drunk." Another author says: "Probably no physician has grasped his life's task with a purer enthusiasm, or devoted himself more faithfully to it, or more fully maintained the moral worthiness of his calling than did the reformer of Einsiedeln." He certainly seems to have been loved and respected by his pupils and followers, for he is referred to by them as "the noble and beloved monarch," "the German Hemes," and "our dear Preceptor and King of Arts."

There seems no doubt that Paracelsus discovered many facts which became of great importance in chemistry: he prepared the inflammable gas we now call hydrogen, by the reaction between iron filings and oil of vitriol; he distinguished metals from substances which had been classed with metals but lacked the essential metalline character of ductility; he made medicinal preparations of mercury, lead and iron, and introduced many new and powerful drugs, notably laudanum. Paracelsus insisted that medicine is a branch of chemistry, and that the restoration of the body of a patient to a condition of chemical equilibrium is the restoration to health.

Paracelsus trusted in his method; he was endeavouring to substitute direct appeal to nature for appeal to the authority of writers about nature. "After me," he cries, "you Avicenna, Galen, Rhasis, Montagnana and the others. You after me, not I after you. You of Paris, you of Montpellier, you of Swabia, of Meissen and Vienna; you who come from the countries along the Danube and the Rhine; and you, too, from the Islands of the Ocean. Follow me. It is not for me to follow you, for mine is the monarchy." But the work was too arduous, the struggle too unequal. "With few appliances, with no accurate knowledge, with no help from the work of others, without polished and sharpened weapons, and without the skill that comes from long handling of instruments of precision, what could Paracelsus effect in his struggle to wrest her secrets from nature? Of necessity, he grew weary of the task, and tried to construct a universe which should be simpler than that most complex order which refused to yield to his analysis." And so he came back to the universe which man constructs for himself, and exclaimed -

  "Each man has ... all the wisdom and power of the world in 
  himself; he possesses one kind of knowledge as much as another, 
  and he who does not find that which is in him cannot truly say 
  that he does not possess it, but only that he was not capable of 
  successfully seeking for it."

We leave a great genius, with his own words in our ears: "Have no care of my misery, reader; let me bear my burden myself. I have two failings: my poverty and my piety. My poverty was thrown in my face by a Burgomaster who had perhaps only seen doctors attired in silken robes, never basking in tattered rags in the sunshine. So it was decreed I was not a doctor. For my piety I am arraigned by the parsons, for ... I do not at all love those who teach what they do not themselves practise."