History of X-Ray

Wilhelm Conrad Röntgen

The first x-ray
Frau Röntgen's left hand

In October of 1895, Wilhelm Conrad Röntgen (1845-1923) who was professor of physics and the director of the Physical Institute of the University of Wurburg, became interested in the work of Hillorf, Crookes, Hertz, and Lenard. The previous June, he had obtained a Lenard tube from Muller and had already repeated some of the original experiments that Lenard had created. He had observed the effects Lenard had as he produced cathode rays in free air. He became so fascinated that he decided to forego his other studies and concentrate solely on the production of cathode rays. One Friday evening, on November 8, 1895, he worked alone in his laboratory. It was the beginning of the weekend and all of his assistants had gone home. He had set up his experiment using a Crookes tube fitted with an anode and cathode, separated from each other by a few centimeters in the tube. He used a Rhumkoff induction coil to produce a difference of potential of a few thousand volts, knowing that a stream of charged particles would originate in the cathode and would be attracted to the anode.

The laboratory Röntgen worked in that evening was very similar to all other laboratories of those who worked before him, but the conditions that existed that evening varied in three very important ways. His laboratory was dark, his tube was covered with a light-proof cardboard jacket and a screen of fluorescent material laid on a table a few feet away from the apparatus. While passing the discharge, he suddenly noticed a shimmering light on the table top. He could not believe his eyes, so he again repeated the experiment. He released the discharge many times producing the same results each time. Greatly excited, he realized that the green fluorescence was emanating from the screen. He repeated the experiment again, this time moving the screen further and further away and he still received the same results.

Röntgen knew the fluorescence could not be produced by the cathode rays since it was well known that they could not penetrate through the wall of the tube. Visible light could not be the stimulus since the tube was covered with a shield which was opaque to light. He boldly hypothesized that he must have been producing some unknown type of radiation.

Röntgen spent the next eight weeks in his laboratory repeating his experiments. He ate and even slept in his laboratory as he attempted to determine if the rays could penetrate substances besides the air. He placed various objects between the tube and screen and he found that the screen still fluoresced but with different intensities depending on the material being used. When he placed a lead disk, which he was holding, in the cathode ray path he was astonished to find the shadow of the round circle appeared on the screen along with the outline of his thumb and forefinger and within them the bones of his hand! He replaced the screen with a photographic plate and employed his wife Bertha (Frau Röntgen) to place her hand on the photographic plate while he directed the rays at it for fifteen minutes.

Röntgen hurriedly prepared his notes so that his first report "On a New Kind of Rays" could be published in the Proceedings of the Physical Medical Society of Wurburg on December 28, 1895. Not knowing what these emanations were he uses the term x-ray to describe the rays he was producing. Later, in 1896, he accepted the Rumford gold medal of the Royal Society and in 1901 he would be the first to receive the Nobel Prize for physics, but he bequeathed the Nobel prize money to scientific research at Wurzburg.

History of Contact Lenses

Seeing our Way into the Future

Contact lenses – new technology? Hardly! Would you believe, way back in 1508, Leonardo Da Vinci sketched and described several forms of contact lenses? Of course, we all know the results of Da Vinci’s insatiable curiosity – he was dedicated to discovering the mysteries of nature. That’s how he came to create the first record of putting a device on the eye to improve vision. He didn’t realize how “visionary” was his idea!

Although the idea of contact lenses had been developed, the technology had not. Step by step, the process was built through the years, from spectacles to today’s contact lenses. Let’s look at each of those steps.

• 1632 – A French philosopher, René Descartes, added to his deep reasonings, the idea of a corneal contact lens.
• 1704 – A French surgeon, Jean Méry, presented a paper to the French Royal Academy of Sciences, reporting that, by submerging the head of a living cat in water, the irregularities of the surface of the cornea were flattened by the water. We’re not sure how he came up with this idea – and we may not want to know! However, the discovery here was that the living eye could be neutralized, or corrected, and that is an essential part of optical contact systems.
• 1801 – Thomas Young, with his medical education, did experiments with light and glass. His conclusion resulted in the development of Descartes idea – a ¼-inch long, water-filled glass tube, which contained a microscopic lens at the outer end. He used this to correct his own vision.
• 1827 – An English astronomer, Sir John Herschel, introduced the idea of grinding a contact lens to conform exactly to the eye’s surface.
• 1887 – A German glassblower, F.E. Muller, manifested Sir John Herschel’s idea into an actual glass lens that covered the entire eye.
• 1888 – A. Eugen Fick, a Swiss physician, and Edouard Kalt, a French optician, simultaneously, but independently, used contact lenses to correct optical defects.

 The modern-day contact lens is developed

A number of years went by until the technology was developed to create the contact lenses as we know them today. But finally, in 1929, Joseph Dallos, a Hungarian physician, perfected a method of making molds of living eyes and using them to form lenses that fit exactly to the shape of the eye.

Then the United States got into the act – the first hard plastic contact lenses made in America were introduced by William Feinbloom, a New York optometrist. They were quite bothersome and could only be tolerated for about 4 hours at which point they had to be removed to replace the saline solution that filled the space between the eye and the lens.

As time progressed, so did the science of contact lenses. 1950 marked the beginning of the modern-day contact lens. Dr. George Butterfield, an Oregon optometrist, designed a lens that rested right on the cornea and was smaller than the size of the iris. A buffer solution was no longer needed, so the lenses could be worn all day.

Up to this point, contact lenses had been made of hard plastic. Then, in 1960, a revolutionary change came – the soft, water-absorbing plastic contact lens. It was developed by Otto Wichterle, a Czech chemist. He used an unbelievable apparatus to make these lenses – a children’s building set and a phonograph motor! But it worked; and it was so inexpensive that he envisioned they could be worn on a disposable basis.
Technology shifts into high gear

With the United States’ acceptance of commercial distribution of contact lenses in 1971, the industry picked up speed. Nearly every year, there was a new development. Here’s how fast technology was developing new creations:

    1978 – toric contact lens ( for astigmatism)
    1979 – rigid gas permeable (RGP) contact lens
    1980 – tinted daily-wear soft contact lens
    1981 – extended-wear soft contact lens
    1982 – bifocal daily-wear soft contact lens
    1983 – tinted RGP contact lens
    1986 – extended-wear RGP contact lens
    1987 – disposable soft contact lens
    1987 – soft contact lens that changes eye color
    1987 – multipurpose lens care products
    1991 – planned replacement contact lens
    1991 – daily-wear 2-week replacement contact lens
    1992 – disposable tinted contact lens
    1995 – daily disposable contact lens
    1995 – RGP contact lens with low silicone content
    1996 – disposable contact lens with ultra-violet absorber

Now that’s progress! And they’re not done yet. The history of contact lenses is still developing. Today soft and colored contact lenses are used for nearly every vision problem correctable with eyeglasses. Wouldn’t Leonardo Da Vinci be proud!

source :http://www.thehistoryof.net/history-contact-lenses-seeing-our-way-future

History of Condoms

Around the world, between six and nine billion condoms are used each year. Unfortunately, their use is not universally accepted. Experts agree that condom use can dramatically reduce the number of new HIV and STD infections each year. Even the Catholic religion, who has always strictly forbidden their use, has recently announced they are considering allowing them in very special circumstances. Yet, some leaders within the church make accusations that condoms don't work and should not be used. Just a few months ago, Pope Benedict said that HIV and AIDS should be controlled with abstinence only. Have you ever wondered where condoms came from? Are you curious to know when they were first used and who invented them? This brief history lesson will answer those questions and provide you with some interesting trivia for your next dinner party.

1000 BC
As far as anyone can tell, this is roughly when the use of condoms was first recorded in history. Unlike today's latex or polyurethane, the first condoms were made of oiled silk paper, linen sheaths, leather, or very thin hollow horn.

AD 200
Cave paintings dating back to the year 200 depict condom use, the earliest known visual evidence of their use.

 

italian condoms

1500s
An Italian doctor by the name of Gabrielle Fallopius (for whom, coincidentally, the female fallopian tube was named) suggested that linen sheath condoms be used to protect against syphilis, a deadly epidemic at that time in history.

1640s
Reports say farmers in Condom, France began using sheep guts as condoms, possibly the origin of the lambskin condom.

1660s
Allegedly, the name "condom" was coined when Charles II was given oiled sheep intestines to use as condoms by a Dr. Condom. However, some believe the name "condom" came from the Latin word "condus" which means "vessel".

1855
Rubber is introduced as a component of condoms. Men are advised that these rubber condoms can be washed and reused until they crumble.

1912
The introduction of latex makes condoms cheap and disposable. Thus, the single-use condom is born. By World War II, latex condoms are mass produced and given to troops all over the world.

1950s
The latex condom is improved by making them thinner, tighter and lubricated. Also, the reservoir tip is introduced that collects semen in the end, decreasing the risk of leakage and unintentional pregnancy.

1980s
Once a source of embarrassment and absolutely forbidden from being advertised in print or on television, the emergence of HIV as a sexually transmitted disease takes condoms into the mainstream. Experts agree that condoms are the best way outside of abstinence to avoid HIV.

2006
Condom sales reach nine billion worldwide. Experts have found the spermicides that kill sperm to prevent pregnancy also increase the risk of HIV; they agree that condoms with spermicides should never be used. Also, with the emergence of latex allergies, condoms are now available made of polyurethane for those people with latex allergies.