Phosphorus.
Phosphorus, or its Latin equivalent, Lucifer, was the name given by the ancient astronomers to the planet Venus when it appeared as a morning star. When it shone as an evening star they called it Hesperus. Do we invent such seductive names now, or do they only seem attractive to us because they are ancient or foreign?
The phosphorescent properties of certain earths had been occasionally noticed by naturalists, but no observation of the kind has been traced in ancient writings. The earliest allusion to a “fire-stone” known occurs in the work of a gossipy French historian named De Thou. In a history of his own times this writer relates that in 1550, when Henri II made his state entry into Boulogne on the occasion of its restoration to France by the English, a stranger in foreign costume presented the king with a fire-stone which, he said, had been brought from India. De Thou narrates that this wonderful stone glowed with inconceivable splendour, was so hot that it could not be touched without danger, and that if confined in a close space it would spring with force into the air.
Sometime early in the seventeenth century, a shoemaker of Bologna, one Vincent Cascariolo, who, in addition to his ordinary business dabbled in alchemy, discovered a stone in the neighbourhood of his city which was luminous in the dark. The stone, which is now known to have been a sulphate of barium, and which the shoemaker calcined, ground, and formed into little round discs about the size of a shilling, and sold for a fancy price, was called the sun-stone. The discs, exposed to a strong light for a few minutes and then withdrawn into a dark room, gave out the incandescent light which we know so well. The discovery excited keen interest among scientific men all over Europe.
Johann Kunckel.
(From the Collection of Etchings in the Royal Gallery at Berlin.)
About 1668 two alchemists named Bauduin and Frueben, who lived at Grossenhayn in Saxony, conceived the idea of extracting by chemical processes the spirit of the world (Spiritus Mundi). Their notion was to combine earth, air, fire, and water in their alembic, and to obtain the essences of all of these in one distillate. They dissolved lime in nitric acid, evaporated to dryness, exposed the residue to the air, and let it absorb humidity. They then distilled this substance and obtained the humidity in a pure form. History does not tell us what questions they put to their spirit of the world when they had thus caught it. It appears, however, that the stuff attained a great sale. It was supplied at 12 groschen the loth, equal to about 1s. 6d. per ounce, and lords and peasants came after it eagerly. Rain-water would have been just as good, Kunckel, who tells the story, remarks. But one day Bauduin broke one of the vessels in which was contained some of the calcined nitrate of lime, and he observed that this, like the Bologna stone, was luminous in the dark after exposure to sunlight. Bauduin appreciated the importance of his discovery, and, taking some of his earth to Dresden, talked about it there. Kunckel, who was then the Elector’s pharmacist, and keenly interested in new discoveries, heard about this curious substance, and was very curious to find out all he could. He visited Bauduin and tried to draw from him the details of his process. But Bauduin was very shy of Kunckel, and the latter has left an amusing account of an evening he spent with his quarry. Kunckel tried to talk chemistry, but Bauduin would only take interest in music. At last, however, Kunckel induced Bauduin to go out of the room to fetch a concave mirror to see if with that the precious phosphorus (for Bauduin had already appropriated this name to the stuff) would absorb the light. While Bauduin was gone Kunckel managed to nip a morsel with his finger-nail. With this, aided by the fragments of information he had been able to steal from Bauduin’s conversation, he commenced to experiment by treating chalk with nitric acid, and ultimately succeeded in producing the coveted luminous earth. He sent a little lump of it to Bauduin as an acknowledgment of the pleasant musical evening the latter had given him.
It was now 1669. Kunckel was visiting Hamburg, and there he showed to a scientific friend a piece of his “phosphorus.” To his surprise the friend was not at all astonished at it, but told Kunckel that an old doctor in Hamburg had produced something much more wonderful. Brandt was the name of the local alchemist. He had been in business, had failed, and was now practising medicine enough to keep him, but was devoting his heart and soul and all his spare time to the discovery of the philosopher’s stone. The two friends visited Brandt, who showed them the real “phosphor” which he had produced, to which, of course, the other substances compared as dip candles might to the electric light, but nothing would induce the old gentleman to disclose any details of his process. Kunckel wrote to a scientific friend happily named Krafft at Dresden about the new “phosphor.” Honour seems to have been cheap among scientific friends at that time, for Krafft posted off to Hamburg, without saying anything to Kunckel about his intention, caught Brandt in a different humour, or perhaps specially hard-up, and bought his secret for 200 thalers.
According to another story, the German chemist Homberg also succeeded in securing Brandt’s secret by taking to him as a present one of those weather prognosticators in which a figure of a man and another of a woman come out of doors or go in when it is going to be wet or fine, as the case may be; a toy which had just then been invented.