Gulliver’s Travels vocabulary

I was at the mathematical school, where the master taught his pupils after a method scarce imaginable to us in Europe. The proposition, and demonstration, were fairly written on a thin wafer, with ink composed of a cephalic tincture. This, the student was to swallow upon a fasting stomach, and for three days following, eat nothing but bread and water.

Jonathan Swift. Gulliver's Travels Into Several Remote Regions of the World (1726)