@TillmannTaape I want to translate "terre cendrée" as "ashed earth," largely to make sure that anyone looking in the glossary doesn't confuse "<fr>cendrée</fr> earth" with the entry for "cendrée," which does not apply here. The fact that the A-P picks up the thread of ashes in the very next <ab> seems to support my proposed translation.
70r: ``` <ab>La <m>terre cendrée</m> moule fort net.</ab> <ab>La <m>cendre</m> n'ha pas assés de corps pour soubstenir le<lb/> <m>cuivre</m>.</ab>
<ab><m><fr>Cendrée</fr> earth</m> molds very neatly.</ab> <ab><m>Ashes</m> do not have enough body to withstand <m>copper</m>.</ab> ``` Cendrée in the glossary: - Cendrée (f.) = 40v_3 keep Fr. Here it refers to a separation of a tin alloy, likely referring to a method of melting and purifying metals in ashes (see Cotgrave). Editorial note: Cendrée here likely refers to a method of melting and purifying metals in ashes (see Cotgrave).
I'm slightly hesitant to translate terre cendrée. There are many different uses of cendres/cendrée in the ms, and it's hard to know what he's referring to here.
Speaking of which, looking for cenrdree in the glossary, I saw the following note by @ps2270 under the cendree d'azur entry: "Both the calcine chalk and charcoal that crucibles are made of, and shop sweepings (dross etc) in a goldsmith’s shop and it is purified by this method. (PHS)." I assume that this is in the wrong place and belongs with the entry on cendree above – Please could you check?