Law schools often illustrate trade secret discussions with the example of Listerine. In the 1880s, Dr. J.J. Lawrence invented the antiseptic liquid compound Listerine, then licensed its secret formula to J. W. Lambert and the Lambert Pharmacal Co. Warner-Lambert Pharmaceutical Co., successor to Lambert and Lambert Pharmacal, dutifully made royalty payments to the Lawrence family over the next 70 years, despite the fact that Listerine's formula was revealed along the way. But in the 1950s Warner-Lambert (now Pfizer Inc.) decided it had shelled out enough money -- more than $22 million, to be exact -- for a secret formula that wasn't even secret anymore. So it sued for a judgment that it was no longer on the line for the licensing fees. Unfortunately for Pfizer, the courts sided with the Lawrence family, ruling that the contract makes no stipulation about stopping payments if the trade secret is legitimately discovered by others, which it could have done. And anyway, since Pfizer had obtained the formula in the beginning, when it was still secret, it had received a decided marketplace advantage [source: Warner-Lambert Pharmaceutical Company v. John J. Reynolds].