Discovery of Penicillin
On Alexander Fleming's desk were some small plates with germs (细菌). One evening, he forgot to cover one of the plates.
When he arrived the next morning, he found a spot of green mold (霉菌) in one plate. This is not strange because the room was very damp(潮湿). But Fleming didn't throw out the spoiled,because something unusual caught his attention. On the uncovered plate, near the green mold, he found no germs. That meant the mold had killed the germs there.Fleming began to study the mold. It grew and grew. Then he noticedvery small drops of liquid on the surface of the mold. Maybe this was the chemical that was killing the germs.
Fleming drew off the liquid with a absorbent tube (吸管), drop by drop.He put this liquid in a clean test tube (试管). When he put the liquid in another test tube with germs, it killed the germs in that tube. He called the liquid penicillin (青霉素).
(责任编辑：威展小王)
