https://www.usluck.com/299207/it-may-be-observed-how-long-it-takes-for-a-useful-fact-to-be-enforced-and-practiced-on-ignaz-semmelweis-was-a-hero/ It may be observed how long it takes for a useful fact to be enforced and practiced on. Ignaz Semmelweis was a hero. #History #HistoryMemes #Memes