The Penicillin

In 1928 Sir Alexander Fleming observed that the colonies of the bacterium Staphylococcus aureus could be destroyed  by the mold Penicillium notatum, proving that there was an antibacterial agent there in principle. This principle later lead to medicines that could kill certain types of disease-causing bacteria inside the body.

At that time, however, the importance of Alexander Fleming's discovery was not known. Use of penicillin did not begin until the 1940s and Howard Florey and Ernst Chain isolated the active ingredient and developed a powdery form of the medicine.

History of Penicillin

Originally noticed by a French medical student, Ernest Duchesne in 1896. Penicillin was rediscovered by bacteriologist Alexander Fleming working at St. Mary's Hospital in London in 1928. He observed that a plate Staphylococcus has been contaminated by a blue-green mold and that colonies of bacteria adjacent to the mold were being dissolved. Curios, Alexander Fleming grew the mold in a pure culture and found that it produced a substance that killed a number of disease-cause bacteria. Naming the substance penicillin, Dr. Fleming in 1929 published the results of his investigations noting that his discovery might have therapeutic value if it could be produced in quantity. 

Dorothy Crowfoot Hodgkin used x-rays to find the structural layouts of atoms and the overall molecular shape of over 100 molecules including penicillin. Dorothy's discovery of the molecular layout of penicillin helped lead scientists to develop other antibiotics.


The Source of the post is www.about.com

Solar Flares

Who discovered them?

 The two astronomers who saw it were called Carrington and Hodgeson. They were independently studying the Sun using special equipment, which enabled them to make observations in visible light safely. They certainly can't have been making X-ray observations. William Röntgen, the German scientist who would later discover X-rays, was only 6 years old at the time!

What was it that Carrington and Hodgeson had seen? We now know they had observed a very large flare because only the very largest can be seen in visible light. Flares are most easily detected in X-rays or ultraviolet radiation.

Check out these two images of the Sun One is taken in X-rays and one in visible light. Very different things can be seen in each one. That's why it's very important that we look at as many different wavelengths in the electromagnetic spectrum as possible when we study the Sun - if we don't we might miss some vital clue to what's going on.