Accidents often promote human knowledge Even better, by making the substance from simple ingredients, at room temperature, the chemists at Sweden's Uppsala University have solved a problem that had out-foxed scientists for nearly two centuries. Even more striking, though, is the mode of its discovery. How did researchers finally crack the problem? Entirely by accident, in fact. It was only when they mistakenly left a reaction bubbling over a long weekend that the experiment proved successful. And so upsalite joins the illustrious list of fortunate accidents. Indeed, the annals of science are littered with blunder, mishap and blind alley made good. Some are breakthroughs of epic proportion - Alexander Fleming stumbling across penicillin because his Staphylococcus cultures were invaded by mould, say, or Wilson Greatbatch fitting the wrong resistor to his heart-recording device and thus creating the pacemaker. Others are more prosaic. Artificial sweeteners were found because a scientist researching coal tar failed to wash his hands before he ate; the humble Post-it note was the brainchild of a failed glue-inventor. As we raise a glass of akvavit to the possibilities of upsalite, then, let's raise one, too, to serendipity. And also - to paraphrase the great microbiologist, Louis Pasteur - to the "prepared mind" that is favoured by chance.