sic = Latin: so [scil. as described before]
scil. = scilicet = Latin: as everybody knows, naturally

BTW, some more Latin abbreviations wich are often found in older books, and might come in handy:
v.s. = vide supra = see above
v.i. = vide infra = see below
e.g. = exempli gratia = for instance
l.c. = loco citato = same reference as cited above

... and don't let the sic make you sick
Wilfried