Compound Microscopes

Factors Affecting Bacterial Growth

admin — Wed, 27 Jun 2007 08:29:29 +0000

Moisture

Water is life, not only for humans, but also for other organisms. Water is necessary for the growth and multiplication of bacteria. Not only is water a major component of the bacterial cell cytoplasm. On an average, 75% to 80% of the bacterial cell is water when examined under a compound microscope, but it also dissolves the food materials in the environment of the bacterial cell so that they can be absorbed.

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Factors Affecting Bacterial Growth

admin — Tue, 26 Jun 2007 00:18:42 +0000

Moisture

Water is life, not only for humans, but also for other organisms. Water is necessary for the growth and multiplication of bacteria. Not only is water a major component of the bacterial cell cytoplasm. On an average, 75% to 80% of the bacterial cell is water when examined under a compound microscope, but it also dissolves the food materials in the environment of the bacterial cell so that they can be absorbed.

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DETERMINING PURITY OF WATER SUPPLY

admin — Sun, 24 Jun 2007 09:27:40 +0000

It was the great bacteriologist Koch who first demonstrated that filtered water would prevent water-borne epidemics. In 1893 he was asked to determine why, when both Hamburg and Altona drank the waters of the river Elbe, the former had a cholera outbreak while the latter remained free from it. Koch was not content with pointing out the fact that Altona filtered its water while Hamburg did not. He first isolated the cholera microbe from the Elbe using a compound microscope. Then he showed it to be present in the water mains and taps of Hamburg, but absent in those of Altona. To clinch the argument, he also showed that the microbe that was examined under a compound microscope, though absent from the filtered Altona water, was present in its unfiltered water.

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MICROBES IN WATER

admin — Sun, 24 Jun 2007 09:26:59 +0000

Water is the great natural diluter. From three fifths to four fifths of the bodies of plant and animal life are made up of water. It is more necessary to life, especially higher life, than more nutritive material. Human beings can survive weeks without food but only days without water.

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WATER FILTERING SYSTEM

admin — Sun, 24 Jun 2007 09:26:13 +0000

The first municipal filtering system in the United States was installed in Scheneetady, N. Y., in 1879. Some years later Lawrence, Mass., developed further the idea of a clean and healthful drinking water. These two cities used filters in which the main constituents were sand and gravel, and the process both mechanical and biological.

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