As in Bagdad during the ninth century, the palmy period of Syrian studies, so in Spain three hundred years later, the work was in its commencement essentially one of interpretation, and the first age of these labours was distinguished by the number of versions which were then produced. From 1182, through the whole of the following century, students laboured in the translation of Moorish books on chemistry. Only towards the close of this period did a tendency become apparent which led in the direction of improvement and innovation. The seed already sown had begun to bear fruit. The material thus derived from Eastern sources was now treated with a new freedom, enriched by the results of original experiment, and edited in forms which betray the influence of scholastic philosophy. The criticism, however, which would determine the precise point when this change began to be operative, and the extent to which it proceeded, attempts what is perhaps an impossible and certainly a difficult task. For it is a remarkable fact that no Arabic texts have been preserved to us which can be regarded as the originals from which these earlier Latin versions were made. This want is probably due to the widespread destruction which overtook the Moorish libraries of Spain.[117] That such originals did at one time exist, however, is made certain by the correspondence which the Latin translations show with those which have come down to us in another language, the Hebrew. The labours of these Latin translators during a hundred years may be found in the manifold collections of chemical treatises, containing some forty or fifty articles apiece, which were arranged and copied out at the beginning of the fourteenth century. These volumes became, after the invention of printing, the chief quarry whence were composed the _Ars Aurifera_; the _Theatrum Chemicum_ of Zetzner, and the _Bibliotheca_ of Manget. We are now in a position to understand, not only the nature and progress of the work in which Michael Scot took part, but the exact development which alchemy had reached in his day, and therefore the relation which his chemical publications bore to the general direction of study in this department of science. The time and care which our survey of the field has demanded need not be thought ill spent. It has prepared the way for a more intelligent appreciation of Scot’s labours as a chemist, and has furnished us with the means of coming to a true judgment regarding their authenticity and value.