Thomas Shirley, The Angler’s Museum, Londres, John Fielding, 1790, p.24
These cod-baits, or cadis, are to be found in gravelly and stony brooks, or rivulets, under great stones, in small husks composed of gravel and sand. You will observe, that the ripest, and those fittest for use, sticks to the stones. When you have got as many as you want to use, put them into a linen bag, tie themp up, and keep them five or six days, dipping the bag once a day in water, which makes them yellow, tough, and sit for use. This bait is made artificially, and takes as well as the natural being not easily distinguished the one from the other in the water.