Lactic Acid: Wackenroder's Calcium Lactate Split with Oxalic Acid (US Dispensatory 1907)

Wackenroder's lactic acid: skimmed milk, milk sugar, chalk and water kept warm for a month. As the acid forms, the chalk takes it up as calcium lactate. That salt is crystallised and then split with exactly enough oxalic acid to free the lactic acid; the lime falls as calcium oxalate. Source: The Dispensatory of the United States of America (1907), Acidum Lacticum. Pharmacopoeial lactic acid, used as food-grade, as ruled. Unknown: how the free acid is separated afterwards; the Dispensatory does not say, so it is linked to an unknown head. The sulphuric-acid version is a separate blueprint. Picture drawn by Youblob.