Trademark distinctiveness both concepts, see Apple Corps and its disputes with Apple, Inc. If a court rules that a trademark has become "generic" through common use (such that the mark no longer performs the essential trademark function and the average consumer no longer considers that exclusive rights attach to it), the corresponding registration may also be ruled invalid. For example, the Bayer company's trademark "Aspirin" has been ruled generic in the United States, so other companies may use that name for acetylsalicylic acid as well (although it is still a trademark in Canada). Xerox for photocopiers and Band-Aid for adhesive bandages are
Hippocrates widely considered to be the "Father of Medicine". His contributions revolutionized the practice of medicine; but after his death the advancement stalled. So revered was Hippocrates that his teachings were largely taken as too great to be improved upon and no significant advancements of his methods were made for a long time. The centuries after Hippocrates' death were marked as much by retrograde movement as by further advancement. For instance, "after the Hippocratic period, the practice of taking clinical case-histories died out," according to Fielding Garrison. After Hippocrates, the next significant physician was Galen, a Greek who lived from AD