CEMENT which quickly hardens in water. This is described in the posthumous works of Mr Hooke, and is recommended for gilding live craw fish, carps, &c. without injuring the fish. The cement for this purpose is prepared, by putting some Burgundy pitch into a new earthen pot, and warming the vessel till it receives so much of the pitch as will stick round it, then strewing some finely-powdered amber over the pitch when growing cold, adding a mixture of three pounds of linseed oil, and one of the oil of turpentine, covering the vessel and boiling them for an hour over a gentle fire, and grinding the mixture as it is wanted with as much pumice-stone in fine powder as will reduce it to the consistence of paint. The fish being wiped dry, the mixture is spread upon it; and the gold leaf being then laid on, the fish may be immediately put into water again, without any danger of the gold coming off, for the matter quickly grows hard in the water.