The Third Part of the Prosperity of Germany

the presses required for the extraction of saltpeter from wood, so that it may be clear to everyone that it is agreeable to nature and can be done with the easiest task, that from any wood a juice may be expressed, which through the air is changed into good saltpeter. I did not want to share the circulatory vessels yet, but rather to keep them for my friends for a little while, although they have been added in this third part.

Similarly, it was not advisable for me to reveal to enemies the transformation of animals, and much less that of minerals, into saltpeter. Nevertheless, by my guidance I have accomplished enough that any of the wise may sufficiently understand that what I have exhibited and somewhat opened is possible to be done. I have not openly taught the method of accomplishing these things, lest I steal from others the opportunity to cultivate their own ingenuity in thinking it out: otherwise, it is prohibited to no one to seek fuller information from those who are knowledgeable in these matters.

Since, therefore, the method of extracting saltpeter from stones is considered the most impossible of all for the unskilled in this art, I have decided to describe it for the grace and utility of posterity. The artifice of this consists more in the recognition of the stones than in the extraction of saltpeter from them. For the extraction is completed in no other way than the preparation of lye from common nitrous earth, regarding which