of a different quality than that upon which the stub of the check had been filled out, and that the writing on stub and check, respectively, had not been made at the same time. It is evident then that the materials themselves and the changes through which they passed in the process of their improvement, the ink and its constituents, the "hand" of the writer and, as well, the peculiarities of the author's style of thought and expression as evidenced by his other and well-known composition (there is a "gait" of mind as well as of walk)--all become, so to speak, the "water marks" which determine or help to determine, approximately, the time at which a book or writing was made or produced. To illustrate: If the antiquarian should "unearth" a manuscript having evidences of great antiquity and should ascertain that it was written upon "cotton paper" that fact would assure him, without any additional evidence whatever, that the document could not be much, if any, earlier than the ninth century, for it was then that cotton paper began to displace the Egyptian papyrus. Or, if the writing was upon "linen paper" then he would be assured by the same kind of evidence that, probably, it was not made before the fourteenth century when paper made from linen rags first came into more common use. VIII PARCHMENT AND VELLUM The skins of animals--sheep, lambs, and calves, and, sometimes, of antelopes, goats, asses, and swine--have served, and from the earliest use of written language, as the favored and the best material upon which to write. By different modes of treatment the skins of animals were converted into "leather," "parchment," and "vellum," respectively, as the finished product. _Leather_, tanned soft, and usually dyed red or yellow, was the material earliest used by the Hebrews. Upon this they wrote their statutes and religious history, and especially the Scroll of the Law. The Yemanite Rolls (Pentateuch and other writings) are all of red skin; and the Pentateuch rolls for the Jews of a certain section of China are of white leather.[24] According to Ctesias and Herodotus, the royal archives of ancient Persia were written on leather. Extant leather rolls are ascribed to the date of about 2,000 B. C. And there are treasured skin-rolls, in the British Museum and elsewhere, which are believed to have been prepared and inscribed as early as 1,500 B. C.