As stated out by iain. Marmite looks and has the consistency of tar. It is very thick and stays in the jar when you turn it upside down.
The marmite company was started in 1902. They manufactured it in Burton On Trent. The location for the company was excellent, it is right next to the A38 so it is easily accesible and it is located nextdoor to the Bass tower. Burton is the centre of all brewing so marmite bought the unused yeast from the brewery which made the company very succesful. They used many different ideas and slogans over the years. including 'a little bovril keeps the doctor away' featuring a bullock standing infront of the doctor. Also a man with blonde hair and a very jolly red cheeked face, bobbing in the sea on a marmite jar. Right up until the most recent slogons 'My mate marmite' and 'I hate Marmite'.
The company still runs in Burton now at the same location under the company bestfoods.

If you drive down the street you can smell the very distinct and strong smell of the marmite and the beer from the bass towers. If you ever have marmite, I suggest you have it with toast or on cheese. mmmmmm .... nice

for more information on the story of marmite ... see:-
http://www.accomodata.com/marmite.htm