Softening wool with urine actually made use of the saponification reaction. Animal wool usually contained grease, and after urine had been left standing for a long time, the urea decomposed, releasing ammonia and producing alkaline substances. Soaking wool in those alkaline substances softened it.
Olive oil, bay laurel oil, and wood ash could also produce a saponification reaction. The famous Marseille soap was made this way. It smelled wonderfully fragrant, though it was rather expensive.
Brera Palace was not far from Sforza's castle. In the fourteenth century, it had still been called Visconti Castle, but it was damaged in a war. In 1447, Francesco Sforza married the daughter of Philippe Visconti, Duke of Milan.
After Francesco became Duke of Milan in 1450, he rebuilt the former Visconti Castle. It was now a public venue that not only displayed artworks, but also had a large garden outside for Milan's residents to stroll and relax in.
But Zabini did not take Georgiana to the castle. He took her to the other side of it, to Milan's "old town."
After Maria Theresa's renovations, it actually looked rather nice. The streets were clean, and there were plenty of ice cream shops. Georgiana took the opportunity to eat several gelatos.
They looked and were shaped no differently from ice cream, but these gelatos were made in small family workshops. Only locals knew which shops were the best.
Zabini bought a whole basketful of strawberry-flavored ones. After casting a Freezing Charm on them, he took her to see Leonardo da Vinci's Last Supper.
It was in the Church of Santa Maria delle Grazie. There were not as many visitors now as there would be in the twentieth century, and when they arrived, there were only a few people there.
Seeing the painting up close was quite