 Hey everybody, Dr. O'Hare. This video I want to talk about two historical figures that are very important in microbiology. So we're going to start here with Igna Semmelweis and then we'll also cover Joseph Lister. They were both doing similar things just in different arenas. So Igna Semmelweis, he's credited with being the first physician that believed that hand washing would be important. So let's just put this in historical context. Because now we think about that as just absolutely ridiculous not to wash your hands. But in this time it was believed that diseases were caused by imbalances between good and evil spirits and the body's humors were critically important, miasmas like foul odors and smells were the cause of disease. You have to understand that he was way, way, way ahead of his time. So much so that there's a little legend here, it's hard to tell, but at least once if not two or three times he was actually let go of his position and had to move on because he just wouldn't give up on this idea that washing hands was important. So he began in the 1840s to start washing his hands with chloride of lime, which would be calcium hypochlorite kind of related to bleach. And he saw that prior to doing this people would be working on a dead body and then going to deliver baby and then up to 30% of the moms were getting this perperol fever and were not making it. So the hospital was a super dangerous place to come and have a baby. That's why midwives and doulas were so popular. So when he started washing his hands with this chloride of lime, he saw drastic reductions, but nobody really believed him. So he really was ahead of his time, but that's what I want you to know about him is crediting him with being the father of hand washing if you want to call it that. Now there are some legends that said that he washed his hands in some mercury or mercury based compounds, which sort of ties into this because it is believed that he ended up in an insane asylum and ended up dying in an insane asylum. So you wonder if something he was washing his hands with like potentially mercury could have led to some of that. Mercury is very neurotoxic. I don't know. I'm just kind of sharing some of the stories and legends that I've heard in this field. So that's Ignis Semawais. I hear I just have a picture of proper hand washing. So you can certainly take a look at that. But of course, we now know how critically important it is. So just imagine how far ahead of his time he was in the 1840s. So the other historical figure I want to talk about here. So this would be Joseph Lister. So you may recognize his name from Listerine. So Joseph Lister, seeing what pastor had been up to with the germ theory of disease, seeing that hand washing had been effective, at least in some case reports, and then also seeing that they were using chemicals, specifically carbolic acid, which we now call phenol, was being used. I think they called it creosote, but it was being used to treat sewage, to get rid of the foul smell of sewage. And obviously they thought foul smells were critically important. So he decided what would happen if we use it on wounds directly. So Joseph Lister is giving credit for the first person developing aseptic surgery practices, if you want to call it that. So he had seen how well it worked controlling sewage. So he tried this carbolic acid, this phenol, on wounds directly. So here I have an actual picture of him. This would have been somewhere in the neighborhood of 1865. That machine right there in the middle of the picture is called the carbolic steam spray. He was using carbolic acid and using it in his surgical suites. So Joseph Lister is credited with creating these antiseptic surgical techniques. Again think about the time, the 1860s were looking at the Civil War area. Think about like a battlefield surgeon in the Civil War. He would amputate someone's limb, rub the blood off of his blade onto his boot, and then go to the next, right? You were just as likely to die. Actually every war up to, I believe, World War I, you were more likely to die from infection than you were from actual battlefield wounds. So think about part of the reason why, how easily things were being spread. All right, so that is Ignis Semmelweis, who is credited with being the father of hand washing as an important clinical practice, and Joseph Lister, who moved those same types of techniques into the surgical suite. All right, have a wonderful day, be blessed.