Samworth's Snippets

The history of the microscope, a penny for your thoughts (magnification),

the book 'Freshwater Algae' and seeing algae with ink!


Events in the history of the microscope

It has been known for over 2000 years that glass bends light, but the first accurate lenses were not made until about the year 1300. Around 1600, it was discovered that optical instruments could be made by combining lenses.

Antony van Leeuwenhoek was a Dutch draper and scientist, and one of the pioneers of microscopy in the late 17th century.
He made his own simple microscopes which had a single lens and were hand-held. He made many drawings of what he saw and is thought to have discovered bacteria, although he didn't know what they were.

In the mid 17th century, Robert Hooke drew pictures of cork seen through his microscope. Like Leeuwenhoek, he did not know exactly what he had seen.

All the early microscopists saw quite distorted images due to the low quality of the glass and imperfect shape of their lenses. Lenses improved a lot through the 19th century, and the microscope as we know it was gradually developed.

In 1933, the first electron microscope was built.

Some dates:

1608 Credit for the invention of the microscope given to Zacharias Jansen

1611 Kepler suggests simple microscope

1614 Giovanni du Pont uses a telescope back to front to look at small things

1625 The word microscope first coined by Giovanni Faber

1665 Hooke published a book of his findings, called Micrographia

1826 James Smith produces first microscope with achromatic lenses

1833 Robert Brown identifies cell nucleus
 
 

A penny for your thoughts...

Think of a penny. As you look at it at a magnification of x1 it is less than 2 cm wide .....


 
 

Artistic Algae

I have been mesmerized by the beauty of the photographs in a new book recently. The book is called 'Freshwater Algae: their microscopic world explored' and is by Hilda Canter-Lund and John W G Lund, with the division of labours being photographs and text respectively.

The standard of images throughout the whole book is superb. I choose the word 'images' here quite consciously because in most cases the photographs are more than just well exposed records of the specimens, but rather display fully the true beauty of the algae. One technique that is used extensively to get effect is that of mounting the specimens in Indian ink to show the presence of mucilage which otherwise would have remained invisible. However, I think this technique has more to offer than that explanation would confer.

 Over the last week or so I have slashed the ink around quite liberally (too much on occasion!) and I would fully recommend people to try it with their pond water samples, it is amazing how much algae it shows up. I find that mounting the sample as usual first is best, and then irrigate with ink by using blotting paper or tissue to draw the ink across. By using this method it is more likely that the right density of ink and therefore degree of opacity can be achieved. You may end up with messy slides but it certainly adds another dimension. Shortly I will put some images onto the site showing some of the effects.

For anyone wishing to obtain the very excellent book, the details are as follows;

Freshwater Algae: Their microscopic world explored, Hilda Canter-Lund and John W G Lund, Biopress Ltd,Bristol, 1995.

Editor's note: an illustrated article on the use of Indian Ink to show the mucilage surrounding desmids written by Bill Ells can be found in our on-line library under Pond-life.

Please do not hesitate to contact me if you have any comments or questions - Comments to the author sent via our contacts page quoting page url plus : ('msamworth','')">Mike Samworth.

 

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