Next week is National Blood Week, and the Blood Transfusion Service is keen to encourage as many people as possible to make a donation.

"We realise that it's often difficult and inconvenient for people to visit our transfusion units," says spokesman Brian Stoker. "Which is why, over the next few days, every household should receive a special blood donation envelope. This is a scheme we pioneered last year, with great success, and we're hopeful that this time around we will do even better."

Bleed into the envelope

Mr Stoker is keen to stress just how easy it is to give blood. There are no doctors or nurses, no expensive equipment or tests. All people will need to do is bleed into the envelope, seal it carefully and label it with the appropriate blood group.

Authorised collectors will then be calling in most areas to pick them up sometime over the weekend. It's quick, clean and completely anonymous. And you can give as little or as much as you like, from the merest pinprick to the full eight pints (further envelopes are available on request).

And as an added incentive, the Blood Transfusion Service is offering tokens for every pint you donate. Collect fifteen and you can exchange them for a free spleen.

Other substances

But Mr Stoker has a word of warning. "Last year one or two jokers thought it would be funny to fill the envelopes with other substances," he explains. "We got envelopes full of soup, salad cream, bolognaise sauce - and one or two more unsavoury fluids. It's not big and it's not clever, so I would like to remind people to be more responsible."

Usually these substitutions are spotted in time, but in one or two well publicised cases it has led to some unfortunate problems.

Most people are probably already aware of the plight of Mr H.P. Bramley of Poole in Dorset. Mr Bramley, whom certain sensationalist newspapers have notoriously labelled 'The Amazing Ketchup Man', was in an accident and was rushed to hospital for an immediate transfusion.

It was a simple enough procedure but distressingly, thanks to the efforts of one thoughtless prankster, Mr Bramley now has at least three pints of tomato sauce coursing through his cardio-vascular system, and as a result he currently finds himself irresistibly drawn to sausages.