How has leeuwenhoek's microscope improved research in biology?

Answer 1

Antoni va Leeuwenhoek (1632-1723) was a Dutch maker of microscopes who made pioneering discoveries concerning protozoa, red blood cells, capillary systems, and the life cycles of insects.Born in Delft, Holland, Leeuwenhoek received little or no scientific education.However, his incredible discoveries in the field of microscopy granted him the recognition as the father of microscopy.In recognition of his discoveries, he was made a fellow of the Royal Society of England.
He was a scientific amateur and as a hobby he devised single, tiny, double-convex lenses mounted between brass plates and held close to the eye. Leeuwenhoek taught himself how to grind and polish glass into a lens with a magnification of 270X (a power that far exceeded that of early compound microscopes of 20-30X). He used this lens to make the world's first practical microscope.His lens, unlike the lenses of the other microscope of the time, was a more pure glass instead of the poor quality, greenish glass of the day.

He confirmed and further developed the discovery by Italian anatomist Marcello Malpighi regarding capillary systems, demonstrating how the red corpuscles circulated through the capillaries of a rabbit's ear and the web of a frog's foot. In 1674, he gave the first accurate description of red blood corpuscles. In 1676, he then observed and described for the first time what he called animalcules—known today as protozoa and bacteria—in pond water, rainwater, in human saliva. In 1677, he described the spermatozoa of both insects and humans.

Leeuwenhoek also opposed the prevalent theory of spontaneous generation, and through the use of the microscope demonstrated that granary weevils, fleas, and mussels were not created from wheat grains and sand but developed from tiny eggs. He described the life cycle of ants, showing how the larvae and pupae originate from eggs.Leeuwenhoek also observed plant and muscle tissue, and described three types of bacteria: bacilli, cocci, and spirilla. He kept the craft of making his lenses a secret, however, so that not until the improvement of the compound microscope in the 19th century were the next observations of bacteria made.

Leeuwenhoek’s microscope
Leeuwenhoek is known to have made over 500 microscopes, yet fewer than ten have survived to the present day.They all had a basic design of a simply powerful magnifying glass; it was nothing like the compound microscopes of the type use today.Compared to modern microscopes, it was an extremely simple device, using only one lens, mounted in a tiny hole in the brass plate that makes up the body of the instrument.The specimen was mounted on the sharp point that sticks up in front of the lens, and its position and focus could be adjusted by turning the two screws.The entire instrument was only 3-4 inches long and had to be held up close to the eye.
Microscope of Today
During the 18th and 19th centuries, the microscope went through a time of several mechanical improvements that increased the stability and facilitated a smooth focus and magnification.Among other things developed during this time to improve the microscope was the creation of microscope stages and slides in order to place and secure the sample to be examined. Also, the development of objective lenses improved and controlled the magnification and resolution of the sample.All these mechanical improvements were added in conjunction with the new sampling techniques that include the addition of water and chemicals to enhance the view of the sample, as well as to stain the sample lead to the production of a high quality clear image.The ability of this new microscope to create such images caught the attention of the scientific community and society in general. The microscope became very popular once again, but this time it underwent a high-volume, low-cost, mass production.
The microscopes were still popular in the early 1900’s. There was not much change in the fundamental basics of the microscopes during this time, however there was a standardization of the parts as a result of the high demands of supplies during the World War I.Among the first standardizations, we find that most microscopes were made out of cast-iron with a blackened finish and the eyepiece had been standardized into a short tube of 23mm diameter.There were many varieties of microscope manufactured during the 1900’s, but most of them had the same general parts.
In the 20th century new developments and improvements have rendered the discoveries of the 19th century to be very basic.The new microscopes are not only able to use light as a way of reflecting the image of the sample, but they are more versatile and capable of using electrons of high resolution power to examine a sample and reproduce its image.The versatility of the microscopes allows one to observe a sample in a 3-dimensional fashion rather than on a flat pain like the conventional microscopes.Also, the magnification power of these new microscopes is incredible; they can easily reach the 200,000x, or 10,000 times more than the earliest microscopes.