(b) _Changes in Language._--The evidence of date derived from changes in the language is more difficult to formulate, and the inquiry calls for the most diligent use of scientific method and critical judgment. Its intricacy lies in the character of the documents before us--religious formularies consisting partly of matter established in usage long before they were written down in their present shape, partly of additions made at the time of writing. The best example of this is furnished by the expansion and modernisation of the subject-matter of Table I. into Tables VI. and VII._a_. Hence we frequently meet with forms which had passed out of the language that was spoken at the time they were engraved, side by side with their equivalents in that language. We may distinguish four periods, as follows: 1. The first period is represented, not by any complete table, but by the old unmodernised forms of Tables III. and IV., which show the original guttural plosives unpalatalized, e.g. _kebu_ = Lat. _cibum_. 2. In the second period the gutturals have been palatalized, but there yet is no change of final _s_ to _r_. This is represented by the rest of III. and IV. and by II. (_a_ and _b_). 3. In the third period final _s_ has everywhere become _r_. This appears in V. (i. and ii. and also iii.). Table I. is a copy or redraft made from older documents during this period. This is shown by the occasional appearance of _r_ instead of final _s_. 4. Soon after the dialect had reached its latest form, the Latin alphabet was adopted. Tables VI. and VII._a_ contain an expanded form of the same liturgical direction as Table I. It is probable that further research will amend this classification in detail, but its main lines are generally accepted. (II.) _Actual Date of the Tables._--Only the leading points can be mentioned here. (i.) The Latin alphabet of the latest Tables resembles that of the _Tabula Bantina_, and might have been engraved at almost any time between 150 B.C. and 50 B.C. It is quite likely that the closer relations with Rome, which began after the Social War, led to the adoption of the Latin alphabet. Hence we should infer that the Tables in Umbrian alphabet were at all events older than 90 B.C.