sodium hydroxide Vs carbonate

From: y2kBug (abcd_at_blabla.co.uk)
Date: 01/29/05 

Date: 28 Jan 2005 16:05:59 -0800

Three days a go I bought 500g sodium Hydroxide and 500g sodium
carbonate un-branded

now i can't tel which is which, would someone tell simple way to
identify them

thankss

y2kbug