assured Helvetius, that of them he could make as much as twenty tons of gold. Helvetius informs us, that he examined them very attentively; and seeing that they were very brittle, he took the opportunity to scrape off a small portion with his thumb-nail. He then returned them to the stranger, with an entreaty that he would perform the process of transmutation before him. The stranger replied, that he was not allowed to do so, and went away. After his departure, Helvetius procured a crucible and a portion of lead, into which, when in a state of fusion, he threw the stolen grain from the philosopher's stone. He was disappointed to find that the grain evaporated altogether, leaving the lead in its original state.
Some weeks afterwards, when he had almost forgotten the subject, he received another visit from the stranger. He again entreated him to explain the processes by which he pretended to transmute lead. The stranger at last consented, and informed him, that one grain was sufficient; but that it was necessary to envelope it in a ball of wax before throwing it on the molten metal; otherwise its extreme volatility would cause it to go off in vapour. They tried the experiment, and succeeded to their heart's content. Helvetius repeated the experiment alone, and converted six ounces of lead into very pure gold.
The fame of this event spread all over the Hague, and all the notable persons of the town flocked to the study of Helvetius to convince themselves of the fact. Helvetius performed the experiment again, in the presence of the Prince of Orange, and several times afterwards, until he exhausted the whole of the powder he had received from the stranger, from whom it is necessary to state, he never received another visit; nor did he ever discover his name or condition. In the following year, Helvetius published his Golden Calf,[1] in which he detailed the above circumstances.
About the same time, the celebrated Father Kircher published his Subterranean World, in which he called the alchymists a congregation of knaves and impostors, and their science a delusion. He admitted that he had himself been a diligent labourer in the field, and had only come to this conclusion after mature consideration and repeated fruitless experiments. All the alchymists were in arms immediately, to refute this formidable antagonist. One Solomon de Blauenstein was the first to grapple with him, and attempted to convict him of wilful misrepresentation, by recalling to his memory the transmutations by Sendivogius, before the Emperor Frederick III. and the Elector of Mayence, all performed within a recent period. Zwelfer
- ↑ "Vitulus Aureus quem Mundus adorat et orat, in quo tractatur de naturæ miraculo transmutandi metalla." Hagæ, 1667.
