IIRC, in Dracula, the vampire wasn't so much burned/incinerated by sunlight as had to go out without his powers. I think it was also a special thing for him, and left him vulnerable. I.E. he could only "go human" or "go vampire" at dusk or dawn, and so was stuck either asleep in his box or awake and powerless until the sun went down.
Note that Dracula was also seen to never eat actual food. He also had a huge suite of magical abilities .... he could shrink down to the size of a bug, poof around as a cloud of dust, control animals, turn into a bat or wolf, mesmerize, etc, most of which modern writers only choose a handful of for their own vampire mythos.
Now, mythological vampires run all over the board. What we call a "vampire" was codified by Stoker in Dracula, and that he ripped off from, IIRC, some central european myths mixed together with some home-grown BS and mythology having nothing to do with things we'd call "vampires". Other cultures, of course, had their own types of myths, and they interchanged and interplayed as people moved about, many of them called "vampires" where they intersected, some with different names and similar powers. Alot of it had to do with fears related to the preservation of bodies ... human tissue shrinks after death, giving the fingernails and hair a "longer" appearance (as the skin draws away), so people who dug up corpses occassionally thought that their hair and nails had continued to grow after death, and thus the body LIVED after death ... addionally human bodies tend to soponificate ... which is to say, the fatty tissues sort of solidify and turn themselves into a rendered soap-like substance. This can give corpses a waxy, "preserved" appearance that lasts into periods when the corpse next door might be rendered into bones and mouldy hair, again giving rise to bodies that live beyond death.
Vampires in modern fiction have a few things in common:
1) Sexy ... Anne Rice sort of crowned this and made it a usual modern feature. Death and Sex often go together, and girls do love a bad boy, so the vampire (as a killer monster in a human body) sex symbol sells.
2) Alive ... It's become pretty popular to have vampires be "alive", it seems ... people infected with a virus or cursed or having a "demon soul" or whatever. Usually these people have their vampires eat real food, since it's pretty silly to have a human-sized blood parasite. Blood just isn't that great a medium for energy transfer when digested and most blood parasites are both expandable and much smaller than their prey.
3) Sunlight Burnable ... Again, this wasn't always in the mythology and does seem to be codified from movie-myth. As the living dead, most mythological vampires had a CONNECTION to the night ... either only coming out at night or only revealing their powers at night or only HAVING power at night, etc. I think it's popular because the modern vampire is a modern superman ... stronger, faster, sexier ... this becomes an obvious drawback and method for keeping the Super-Sexy Brigade in check, which serves to make them EVEN SEXIER because they can be tragic figures while kicking butt and looking hot.
People usually play with these, combining and dropping features, putting together their own "logical" and "realistic" vampires, etc. Oddly, "real" mythology is usually the most bizzare ... like variations on some eastern vampires whose HEADS are vampires ... the head pops off and goes rolling about with some entrails attached to it, it climbs around and sucks blood ...
--fje
