Viz., why the contracted form of Videlicet

I shall be much obliged if any one of your readers can inform me of the principle of the contraction viz. for videlicet, the letter z not being at all a component part of the three final syllables in the full world. [Is not our correspondent a little mistaken in supposing that the last letter in "viz." as originally a letter z? Was it not one of the arbitrary marks of contraction used by the scribes of the middle ages, and being in form something like a "z," came to be represented by the early printers by that letter? In short, the sign3 was a common abbreviation in records for terminations, a…