If such a receipt is valuable as indicating the chemical practice of those days, it is no less interesting as it throws light upon the life and occupations of Scot. He must have set up a complete chemical laboratory at Toledo, with crucibles for the melting of metals, and alembics for the distillation of the substances which his art required him to mix with them. His situation was one very favourable to these pursuits, not only because Spain was one of those countries where the doctrine of alchemy made its greatest progress, and attracted most powerfully the concourse of foreign adepts, but also from the facility with which the necessary _materia chemica_ could there be procured. The _sierras_ of that country were full of mineral wealth of all kinds, especially quicksilver, which was one of the substances most frequently chosen to become the subject of the transmuter’s art. In the _Alpujarras_, a mountainous district lying under the soft climate of Granada, grew plenty of these rare herbs employed in alchemy, as they were also in the medicine of the Arabians. Ibn Beithar of Malaga describes them in his botanical thesaurus, and it is said that after the Moors had lost that fair kingdom their herbalists, even as late as our own times, made yearly journeys from Africa to gather in these hills the plants which ancient science taught them to value highly. But the days of the ‘ultimo sospiro del Moro’ were yet in the far future, and meanwhile Michael Scot in his laboratory at Toledo could easily command all these treasures for the purposes of experiment. Nor was it in vain that he fanned his fires, and watched the metals melt and the menstruum distil in the process of the lesser or greater mystery. If he never saw _Venus_ blush into the true substance of _Sol_, or _Mercury_, the fickle and obstinate, congeal into a veritable _Luna_, his chemical practice, and the records in which he has embodied it, mark none the less true and significant a moment in the history of scientific progress. CHAPTER V THE ASTRONOMICAL WRITINGS OF SCOT