Abstract
Once constituted, scientific facts have a way of roaming about on their own in the world, much divorced from the circumstances of their original constitution. An important part of Latour and Woolgar's discussion in Laboratory Life was to draw attention to how facts are used once they are at the final stage of their constitution. What I propose to do here is to go one step further, and to follow a single fact around in the wild—to tag it, as it were, much as a biologist might tag an animal with a radio collar—and then look to see where it turns up. The fact I have chosen is especially taggable, simply because it happens to be fantastic: I refer to the fact that magnets will lose their power of attraction if they are rubbed with garlic. This fact is also useful because it shows up in authors spanning fifteen centuries, from Plutarch through Rabelais and beyond, and over this time it shows some interesting behaviors. Of course, in the end, the garlic-magnet antipathy was disproved, and so changed its epistemological status, moving from one extreme to the other: from the obviously true to the obviously ridiculous. What struck Rabe-