In theory, any person charged with a crime is presumed innocent until proved guilty. But, when it comes to substances, people are always prepared to think the worst and never let the facts get in the way of a really good urban myth. For more than a century or two, the world has been fixated with the idea that saltpeter can be used to induce impotence in men. For those of you with an interest in the scientific side of life, saltpeter is better known as potassium nitrate (KNO3) and, for many decades, rumor had it that this dreaded substance was craftily slipped into the food of prison inmates, those lucky enough to serve their country in the armed forces, and young men in single-sex schools and colleges. The result was peace and calm. All those unfortunate sexual urges that might have made it difficult to maintain discipline, were happily damped down.

The truth is rather more boring. Like many other chemical substances, if you were unfortunate enough to eat too much of it, it would make you sick. As a side effect of this sickness, men would tend to lose interest in sex. But the idea that a pinch or two of potassium nitrate added into food by willing accomplices among the kitchen staff would induce impotence is pure fiction. In fact, it’s the literal opposite that’s true.

For centuries, saltpeter has been added to food because it’s a preservative. Before the invention of the refrigerator, kitchens routinely salted meat to keep it edible during the long winter months. Today, the traditional cans of corned beef still contain saltpeter — it has always been man’s friend when used in moderation. Saltpeter first emerged in China about 2,000 years ago. Early experiments saw Chinese chemists getting the best and the worst results, depending on your point of view. The compost heaps containing decomposing organic matter were covered and spiked with dung and urine. When the resulting "mess" was filtered and wood ash added, this was wonderful fertilizer and the basis of fireworks for celebrations. Later, of course, it made explosives for war.

Modern science is a wonderful thing (when it works). It has built bigger and better fireworks and developed viagra as a sure-fire cure for erectile dysfunction. With the spread of refrigerators and the use of radiation to extend the shelf-life of food, there is less need for saltpeter. Indeed, because of the threat of urban terrorism, people who buy large quantities of fertilizer are monitored carefully (and that’s no myth). But, of course, when there are not enough explosions in the bedroom, viagra is the first response for the men affected. The performance of this drug is no myth. In every clinical trial and with now more than a decade of practical experience in the real world, viagra has consistently proved itself able to produce erections hard enough for penetration. So even if modern men were to eat saltpeter in their food (no matter who put it there or why), there would always be a remedy to keep men’s libido on high.