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Jan Swammerdam
Jan Swammerdam

Jan Swammerdam (February 12, 1637, Amsterdam - February 17, 1680) was a Dutch biologist and microscopist. Events 1429 - English Forces under Sir John Fastolf defend a supply convoy carrying rations to the army besieging Orleans from attack by the Amsterdam (pronounced) is the capital and largest city of the Netherlands, located in the province of North Holland in the west Events 1500 - Battle of Hemmingstedt. 1600 - Philosopher Giordano Bruno is burned alive at Campo de' Fiori The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands His work on insects demonstrated that the various phases during the life of an insect—egg, larva, pupa, and adult—are different forms of the same animal. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described In most Birds and Reptiles an egg ( Latin ovum) is the Zygote, resulting from Fertilization of the Ovum. A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example A pupa ( Latin pupa for doll pl pupae or pupas) is the life stage of some Insects undergoing transformation As part of his anatomical research, he carried out experiments on muscle contraction. A muscles contraction (also known as a muscle twitch or simply twitch) occurs when a Muscle fibre generates tension through the action of Actin In 1668, he was the first to observe and describe red blood cells. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood He was one of the first people to use the microscope in dissections, and his techniques remained useful for hundreds of years. A microscope ( Greek: ( micron) = small + ( skopein) = to look or see is an instrument for viewing objects that are

Contents

Biography

Swammerdam was born in Amsterdam. His father was an apothecary, and an amateur collector of minerals, coins, fossils, and insects from around the world. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described His mother died in 1661. The same year, when he was 24, Swammerdam entered the University of Leiden to study medicine. Leiden University (Universiteit Leiden located in the city of Leiden, is the oldest University in The Netherlands. After qualifying as a candidate in medicine in 1663, he left for France, spending time in Issy, Saumur and Paris with Melchisédech Thévenot. Issy-les-Moulineaux is a commune in the southwestern suburban area of Paris, France. Saumur is a town and commune in the Maine-et-Loire département of France on the Loire River at, with an approximate Paris (ˈpærɨs in English; in French) is the Capital of France and the country's largest city Melchisédech (or Melchisédec) Thévenot (c 1620 - October 29, 1692) was a French author scientist traveler cartographer He returned to Leiden in September 1665, and earned his M. D. on February 22, 1667.

Once he left university, he spent much of his time pursuing his interest in insects. This choice caused a rift between Swammerdam and his father, who thought his son should practice medicine. The relationship between the two deteriorated; Swammerdam's father cut off his financial support for Swammerdam's entomological studies. As a result, Swammerdam was forced, at least occasionally, to practice medicine in order to finance his own research.

From 1667 through 1674, Swammerdam continued his research and published three books. In 1675, he came under the influence of the Flemish mystic, Antoinette Bourignon, renounced his work, and decided to devote the remainder of his life to spiritual matters. The terms Fleming and Flemings ( Vlaming and Vlamingen in Dutch) denote respectively a person and people and the Flemings or Mysticism (from the Greek grc μυστικός mystikos, an initiate of a Mystery religion) is the pursuit of communion with identity Antoinette Bourignon de la Porte ( January 13, 1616 - October 30, 1680) was a Flemish mystic. Niels Stensen, a gifted anatomist, and once his co-student, invited him to work for the Duke of Tuscany, but Swammerdam refused. Nicolas Steno ( Danish: Niels Stensen; Latinized to Nicolaus Stenonis) ( January 10, 1638 - November 25, There is evidence, however, that he did not completely give up his scientific studies. The papers, which he wished to be published posthumously, appear to have been revised during the last two years of his life. He died at age 43 of malaria. In 1737-1738, a half century after his death, Herman Boerhaave translated Swammerdam's papers into Latin and published them under the title Biblia naturae (Book of Nature). Herman Boerhaave ( Voorhout, December 31, 1668 - Leiden, September 23, 1738) was a Dutch botanist humanist

Research on Insects

Illustration of a Mosquito from Historia
Illustration of a Mosquito from Historia

Knowledge of insects in the 17th century was to a great extent inherited from Aristotle. Aristotle (Greek Aristotélēs) (384 BC – 322 BC was a Greek philosopher a student of Plato and teacher of Alexander the Great. According to this classical paradigm, insects were so insignificant they weren't worthy of the types of investigations done on fish, reptiles, and mammals. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two Reptiles, or members of the class Reptilia are air-breathing Cold-blooded Vertebrates that have skin covered in scales as opposed to hair or feathers Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Much of Swammerdam's entomological work was done to show that the difference between insects and the "higher" animals was one of degree, not kind. Swammerdam is credited with the enhancement of the study of biology due to his work dissecting insects and studying them under microscopes. [1]

Swammerdam's principal interest in this area was demonstrating that insects develop in the same gradual manner as other animals. He wanted to dispel the seventeenth-century notion of metamorphosis—the idea that different life stages of an insect (e. Metamorphosis is a Biological process by which an Animal physically develops after Birth or hatching involving a conspicuous and relatively g. caterpillar and butterfly) represent a sudden change from one type of animal to another. Caterpillars are the Larval form of a member of the order Lepidoptera (the Insect order comprising butterflies and Moths A butterfly is an Insect of the order Lepidoptera. Like all Lepidoptera butterflies are notable for their unusual life cycle with a He garnered evidence against this claim from his dissections. By examining larvae, he identified underdeveloped adult features in pre-adult animals. For example, he noticed that the wings of dragonflies and mayflies exist prior to their final molt. Anisoptera redirects here For the genus of trees see Anisoptera (tree. Mayflies are Insects which belong to the Order Ephemeroptera (from the Greek ephemeros = "short-lived" pteron Ecdysis is the Molting of the Cuticula in Arthropods and related groups ( Ecdysozoa) Swammerdam used these observations to bolster his case for epigenesis in his 1669 publication, Historia Insectorum Generalis (The Natural History of insects). This work also included many descriptions of insect anatomy. It was here that Swammerdam revealed that the "king" bee has ovaries. "Ovaria" redirects here This is also a proposed section and a Synonym of Solanum. Biblia natura published posthumously in 1737, carried the first confirmation that the queen bee is the sole mother of the colony. Despite five intense years of beekeeping, the mode of honey bee reproduction escaped him as he wrote, "I do not believe the male bees actually copulate with the females. Beekeeping (or apiculture, from Latin apis, Bee) is the maintenance of Honey bee colonies commonly in Hives "[2]

In addition to his research on metamorphosis, Swammerdam's entomological work stands out because he was among the first people to study insects in a systematized fashion (i. e. , careful dissection, comparison of different species, and use of the microscope). His anat behavioral descriptions of bees, wasps, ants, dragonflies, snails, worms, and butterflies were major contributions to the nascent field of entomology in the late seventeenth century. Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea A wasp is any Insect of the order Hymenoptera and suborder Apocrita that is neither a Bee nor Ant. Ants are social Insects of the family Formicidae and along with the related families of Wasps and Bees belong to the order Anisoptera redirects here For the genus of trees see Anisoptera (tree. The word snail is a Common name that can be used for almost all members of the Molluscan class Gastropoda which have coiled shells in the Worms (voɐms is a City in Rhineland-Palatinate, Germany, on the Rhine River A butterfly is an Insect of the order Lepidoptera. Like all Lepidoptera butterflies are notable for their unusual life cycle with a Entomology (from Greek grc ἔντομος entomos, "that which is cut in pieces or engraved/segmented" hence "insect" and grc -λογία As a means of recording the passage of Time, the 17th Century was that Century which lasted from 1601 - 1700 in the Gregorian calendar

Besides Historia, he published Miraculum naturae sive uteri muliebris fabrica in 1672 and Ephemeri vita, in 1674. The latter was a study of the mayfly, written at a time when he was becoming increasingly involved in spiritual matters. The work contains long passages on the glory of the creator. His Bybel der Natuure was a collection of his papers and drawings.

Research on Anatomy

Swammerdam's illustration of a nerve-muscle preparation. He placed a frog thigh muscle in a glass syringe with a nerve protruding from a hole in the side of the container. Irritating the nerve caused the muscle to contract, but the level of the water, and thus the volume of the muscle, did not increase.
Swammerdam's illustration of a nerve-muscle preparation. He placed a frog thigh muscle in a glass syringe with a nerve protruding from a hole in the side of the container. Irritating the nerve caused the muscle to contract, but the level of the water, and thus the volume of the muscle, did not increase.

Swammerdam was not a pioneer in the study of anatomy as he was in study of insects, but he nonetheless made important contributions. His use of, and experiments with, frog muscle preparations played a key role in the development of our current understanding of nerve-muscle function. A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the The experiments introduced a new method of studying nerves, the frog nerve-muscle preparation, which was still used centuries later. [1]

In one experiment, Swammerdam removed the heart of a frog and observed that touching certain areas of the brain caused certain muscles to contract. For Swammerdam, this was evidence that the brain, not the circulatory system, was responsible for muscle contraction. This is an article about the rock music band "Circulatory System" A muscles contraction (also known as a muscle twitch or simply twitch) occurs when a Muscle fibre generates tension through the action of Actin

Swammerdam played a key role in the debunking of the balloonist theory, the idea that 'moving spirits' are responsible for muscle contractions. Balloonist theory was a theory in early Neuroscience that attempted to explain Muscle movement by asserting that muscles contract by inflating with air or fluid The idea, supported by the Greek physician Galen, held that nerves were hollow and the movement of spirits through them propelled muscle motion. Galen ( Greek: Γαληνός Galēnos; Latin: Claudius Galenus, Aelius Galenus, Claudius Aelius Galenus, or [1] René Descartes furthered the idea by basing it on a model of hydraulics, suggesting that the spirits were analogous to fluids or gasses and calling them 'animal spirits'. For the mechanical technology see Hydraulic machinery and Hydraulic cylinder Hydraulics is a topic of science and Engineering [1] In the model, which Descartes used to explain reflexes, the spirits would flow from the ventricles of the brain, through the nerves, and to the muscles to animate the latter. A reflex action, also known as a reflex, is an involuntary and almost instant movement in response to stimulus. The ventricular system is a set of structures in the Brain continuous with the Central canal of the Spinal cord. [1] According to this hypothesis, muscles would grow larger when they contract because of the animal spirits flowing into them. To test this idea, Swammerdam placed severed frog thigh muscle in an airtight syringe with a small amount of water in the tip. [1] He could thus determine whether there was a change the volume of the muscle when it contracted by observing a change in the level of the water (image at right). [1] When Swammerdam caused the muscle to contract by irritating the nerve, the water level did not rise but rather was lowered by a minute amount; this showed that no air or fluid could be flowing into the muscle. [1] Swammerdam did not believe the results of his own experiment, suggesting that they were the result of artifact. [1] However, he concluded in his book The Book of Nature II that "motion or irritation of the nerve alone is necessary to produce muscular motion". [1] This idea that nerve stimulation led to movement had important implications for neuroscience by putting forward the idea that behavior is based on stimuli. Neuroscience is a field devoted to the scientific study of the nervous system [1]

Swammerdam also discovered valves in the lymphatic system, which were later dubbed Swammerdam valves.

Contributions to Methodology

Though Swammerdam's work on insects and anatomy was significant, many current histories remember him as much for his methods and skill with microscopes as for his discoveries. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration He developed new techniques for examining, preserving, and dissecting specimens, including wax injection to make viewing blood vessels easier.

Spirituality

Swammerdam's scientific work was deeply influenced by his religious views. For him, studying the Earth's creatures revealed the greatness of God; scientific pursuits were pious activities. His spiritual views not only motivated his work, but also affected his ideas about the natural world. For example, he rejected metamorphosis and spontaneous generation because they represented randomness and haphazardness that was not possible in a world regulated by God. Metamorphosis is a Biological process by which an Animal physically develops after Birth or hatching involving a conspicuous and relatively In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic

His ultimate departure from the scientific scene in 1675 can also be attributed to his religiosity. Perhaps due to the influence of Antoinette Bourignon, Swammerdam came to believe that his scientific work was no longer in the service of God. Antoinette Bourignon de la Porte ( January 13, 1616 - October 30, 1680) was a Flemish mystic. He thought he was conducting investigations into the natural world merely to satisfy his own curiosity. As a result, he subjected himself to the tutelage of Bourignon and, for the most part, renounced scientific study.

External links

Bibliography

Further reading

References and notes

  1. ^ a b c d e f g h i j k Cobb M (2002). "Timeline: Exorcizing the animal spirits: Jan Swammerdam on nerve function" (pdf). Nature Reviews Neuroscience 3 (5): 395–400. doi:10.1038/nrn806. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 11988778.  
  2. ^ Biblia natura, 1737, translated to English as The Book of Nature, 1758, by Swammerdam.
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