Making and Knowing
A minimal edition of BnF Ms Fr 640 in English Translation

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Annotations: Ox Bone and Rock Salt

Powder of ox bone and rock salt

I pulverised them separately and ground them finely on the porphyry as much as I could. Then I mixed all of one with the other and re—ground it on the porphyry. Afterwards I moistened it in paper folded in a moist napkin which is made wet more quickly from the moisture of the night, or the moisture of the cellar. I have never found one which can be removed more cleanly from the mold than this, though it needs to be quite moist. And if you want to cast small works, make it very hot. It came out very cleanly from the doulx tin, like the main one, and has sustained several castings. For tin, I believe that it is not necessary to look further to find a material that takes to powder better, and even for use with fine lead which has almost better results than tinTou. The bone of an ox hoof is always dry, that is why you must mix it with fatty sand, so it will bind like tripoli, salts, felt, ashes and similar materials. If you do not mix ox—hoof bone, it will not turn out from the mold and will not mold cleanly because it crumbles.