What is undoubtedly the oldest prescription in America is listed under Accession Number 988 at the New York Metropolitan Museum of Arts. Its date is probably not later than 1500 B. C., some time during the nineteenth dynasty. It is written on a small piece of limestone, about three and one-half by three inches in its present somewhat injured condition, carefully smoothed for the purpose, forming what is called an "ostracon." The writing was done with a brush and some sort of black ink or paint, for pens did not come into use in Egypt until the Roman time. The substance employed was well adapted to its purpose, for the writing is still quite plain, except near the edges of the stone where fragmentation has occurred. The inscription is in the old cursive hieratic writing, somewhat similar to that of the Ebers papyrus, which dates from about 1600 B. C.