An historical example of a metaphor used by a scientist:
"The objections opposing, not the inoculation of the tubercle which is undeniable, but its virulence and specificity, have been raised not only against glanders, its first cousin, but also against syphilis, which is more distantly related. The syphilis virus, just like the glanders and tuberculosis viruses, has had its sworn enemies, and the arms used to oppose it were none other than those recuperated by the adversaries of the specificity of tuberculosis. The first line of argument was also to deny inoculability and to oppose negative or contradictory experimental results against positive results."
Jean-Antoine Villemin
Villemin, J. A. (1868/2015). On the virulence and specificity of tuberculosis [De la virulence et de la spécificité de la tuberculose]. The International Journal of Tuberculosis and Lung Disease
