text:  Cennino himself speaks of many of his recipes as great secrets; and we are told that Van Eyck only in his old age taught his secret to Antonello--and the whole story goes to show the profound secrecy with which this vehicle was retained; nor is there any reason to doubt that it occasioned the murder of Domenico said to have been perpetrated in 1470 thirty-three years after the writing of Cennino Cennini