Tartrelic acid

Most probably both tertralio and tartrelic acids are mere combinations of anhydrous tartaric acid with varied proportions of crystallized tartaric acid. 

If the heat—374 —be carefully maintained for yet a longer time, anhydrous tartaric acid or tartaric anhydride remains in form of a white, porous mass insoluble in water. Adherent tartrelic acid is removed by washing with water till the wash liquor no-longer reddens litmus. By contact with co]d water for a few hours anhydrous tartaric acid resumes its basic water. 

---

See also in sourсe #XX -- [ ]

---