This database was initially constructed by creating a union catalogue of the Ferguson collection, the Young collection, the Herzog August Bibliothek Wolfenbuttel, the Duveen collection in Wisconsin, the Bibliotheca Philosophica Hermetica in Amsterdam, the British Library (only some items done to date), the Bibliotheque Nationale in Paris (only a few items done to date), and entries from the National Union Catalogue of USA Libraries, and a few other sources.
There are a number of things one must bear in mind when using this catalogue.
Some of these entries will be incorrect, as I have not been able, except in a small percentage of cases, to examine the book itself. As I have taken information from published catalogues I will have unwittingly imported their inaccuracies. For example, it is my experience that Ferguson's Bibliotheca Chemica, though still accepted today as the prime bibliographic sourcework on alchemical literature, cannot entirely be relied upon. He occasionally makes errors when he tries to give a history of the editions of a work.
Some of this information will be incomplete, as there may be editions of works, or even original works, which have not been identified through my method of uniting the major holdings of alchemical books.
There may be books in this database which are not truly 'alchemical', say works primarily on medicine, or herbs, natural history, metallurgy, mining, or indeed items which more correctly belong to the domain of early chemistry. Different cataloguers use the term 'alchemical' in different ways, and one can in any case argue for ever about such definitions. However, some rogue elements will have crept into this catalogue, which can only be seen not to address alchemy, by examining the work itself and not merely the title. I would appreciate help here - if someone knows a work definitely has little alchemical import please let me know and I will remove it from the list.
There may be redundant or 'ghost' works in this database. Often when the title page does not indicate a printer, place or date of publication, bibliographers and cataloguers zealously try to provide us with the information, and can then create entries for editions which never really existed. Only an examination of the books themselves can clear up such problems.
There are also problems regarding reissues of editions. Sometimes a printer (for various reasons) would take the printed sheets of a book, and reissue them with a different or amended title page. This didn't really produce a new edition of a work, as no editorial changes have been made, but it is impossible to identify such reissues without seeing both works side by side. I have tried to discriminate between reissues, reprints and new editions.
There is a problem in identifying the sequence of translations of various works. It many cases this is straightforward, but with some works it is not easy to tell whether a particular book is, say, a translation into German of a Latin work, without examining the different editions, as the German title may not be a literal translation of the Latin.
The numbering system I have adopted is an attempt to sort out the sequence of editions. The whole number part identifies a unique work, the part after the decimal point indicates the sequence of editions. Thus there are 4642 books in this database at present but 2825 or so unique works. These numbers will not change as I update the catalogue, as I will insert books into the sequence using alphabetical suffixes, and delete numbers if a book is removed from the database. So these numbers can now be used as unique identifiers for pre-1800 alchemy books.
The books in the first part of the catalogue, up to the letter 'L' have been checked against the National Union catalogue and the sequence of editions has been to some extent unravelled. The second half of the catalogue will, consequently have more errors in this regard.
The cut-off date of 1800 is not entirely artificial, as there is an almost complete cessation of alchemical publishing in the 19th century. In a few exceptional cases I have included entries from the 19th century where these continue the tradition of alchemical publication, but a database of modern writings (post-1800) on alchemy has been started as a separate project.
If anyone has done a bibliographic survey of a particular alchemical writer, or knows of any such reliable comprehensive bibliography, please send me a copy or let me know the source, as this sort of material can substantially assist me in solving the problems of making this catalogue. Regarding Paracelsus, note I have not found time to integrate the Sudhoff catalogue with the listing here. It is not that I am unaware of this source - merely that I haven't been able to undertake this task as yet.