In the autumn of 1928, a Scottish bacteriologist Alexander Fleming was searching for a substance that would kill deadly germs . On his desk were small plates containing the germs. One evening , he forgot to cover one of the plates .When he arrived the next morning , he found a spot of green mold in one plate. This is not strange because the room was rather damp, with only one window .But Fleming did not throw out the spoiled plate ,because something unusual caught his attention.
On the uncovered plate , near the green mold , the germs disappeared .That meant that the mold had killed the germs there. Fleming watched the mold grow for several days. As the green mold spread , it killed more and more germs .
Fleming began to study the mysterious mold .It grew and grew .Then he noticed tiny drops of liquid on the surface of the mold .Perhaps this was the chemical that was destroying the germs.
Fleming drew off the liquid ,drop by drop. He put this liquid in a test tube ,and it killed the germs in the tube .He called the liquid penicillin.
Fleming published his findings in a British medical journal in 1929. But for ten years ,while he continued to experiment with penicillin, his discovery was largely ignored by the medical world .
Then in 1938, a team of British scientists happened to read Fleming ‘s findings in an old medical journal .They made further experiment with the drug .They tested it on animals and then on human beings .In 1941, it was declared safe for use on humans .Soon penicillin was produced in large quantity and was used to treat many infections .
Penicillin is a very powerful drug .It can treat many kinds of infections .However, it has some side effects . Sometimes it causes a skin rash or a light fever .And it can be fatal for people who are sensitive to it .That is why before you take a penicillin shot , the doctor gives you a test shot first .

1928年秋,一位苏格兰细菌学家亚历山大.佛来明在寻找一种能够杀死致命细菌的物质.他在书桌上放了盛着细菌的小盘子.一天晚上,他忘记把盘子盖上盖子了.第二天早上,当他到来的时候,他发现一个盘子里有一点青苔.这并不奇怪,因为房间只有一扇窗户,所以很潮湿.但是佛来明没有扔掉这盘被毁坏的细菌,因为他的注意力被不寻常的情况吸引住了.
在没有盖子的盘子上,那些青苔附近,细菌消失了.这意味着青苔把细菌杀死了. 佛来明对青苔的生长情况观察了几天.随着青苔的扩散,越来越多的细菌被杀死了.
佛来明开始研究这种神秘的青苔.它不断生长.接下来他在青苔表面发现了几小滴液体.也许那就是消灭了细菌的化学物质.
佛来明一滴一滴地把液体吸走.他把这种液体放到一个试管里,里面的细菌被杀死了. 他将这种液体命名为盘尼西林(青霉素).
佛来明于1929年把他的发现发表在英国一家药品杂志上.但是在他继续研究青霉素的10年时间里,他的发现被医药界大大忽略了.
接着在1938年,一组科学家无意中读到了佛来明在旧药学杂志上发表的发现.他们对这种药品进行了进一步的实验.他们先在动物身上试验,然后在人身上试验.1941年,这种药被证明在人身上使用是安全的.很快青霉素就大量生产并用于治疗多种感染.
青霉素是一种非常有效的药品.它可以治疗多种感染.但是它有一些副作用.有时它会引起皮疹或低烧.对它过敏的人使用它产将是致命的.这就是为什么你在注册青霉素前医生要给你进行试敏的原因.