Here is the solution for the Chemistry Lab level:
  From the starting screen, head left and trip the switch that you find
  there.  This turns off some of the deadly electrical devices and allows
  you to enter a previously inaccessible screen.  Go up the ladder and
  walk to the left, then use the conveyor belt to fall down and collect
  the crowbar.
  Next make your way to the auto ladder.  Use the crowbar and jump on the
  lever three times.
  Go up and collect the jam jar, before returning down and heading right
  to where the other jar is.  Go down two levels and head right.  Use the
  jam jars, and you will be able to read the tiny password and pass through
  the locked door.  Go right.  Collect the hammer and take it up to the
  top level.
  Head left and collect the phial (there's a clue about a "strong aroma"),
  and head down to where the 'test your strength' machine is.  Use the
  potion and the hammer and you will ring the bell, revealing an oil can
  as your prize.  Take this up to the top-right hand screen and use it on
  the pipe and, voila, you have completed the level!