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Nagai Nagayoshi

Nagai Nagayoshi is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nagai Nagayoshi rather than just read about it. In short: Nagai Nagayoshi (長井 長義; August 8, 1844 – February 10, 1929) was a Japanese doctor of pharmacy and chemist. He is best known for the discovery of ephedrine and methamphetamine.

Nagai Nagayoshi — main illustration
Nagai Nagayoshi — illustration

Key takeaways

  • Nagai Nagayoshi belongs to chemistry; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Nagai Nagayoshi to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Nagai Nagayoshi from memory before moving on to harder problems.

Reference excerpt

Nagai Nagayoshi (長井 長義; August 8, 1844 – February 10, 1929) was a Japanese doctor of pharmacy and chemist. He is best known for the discovery of ephedrine and methamphetamine.

Early life Nagai was born in Myōdō District, Awa Province in what is now Tokushima Prefecture, as the son of a doctor and started studying rangaku medicine at the Dutch Medical School of Nagasaki (Igaku-Denshujo) in 1864. While in Nagasaki, he made the acquaintance of Ōkubo Toshimichi, Itō Hirobumi, and other future leaders of the Meiji government.

Career Nagai continued his studies at Tokyo Imperial University and became the first doctor of pharmacy in Japan. He was sent under government sponsorship to Prussia in 1871 to study at the University of Berlin. He was the only civilian in a group of military students sent to study in Great Britain and France, and he traveled by way of the United States and Great Britain. While in Berlin, he resided at the home of Japanese diplomat Aoki Shūzō. He was influenced by the lectures of von Hofmann, and received a doctorate with a study on eugenol while working as an assistant at von Hofmann's laboratory. He decided to take up organic chemistry in 1873. Nagai returned to Japan in 1883 to take up a position at the Tokyo Imperial University, and became Professor of Chemistry and Pharmacy there in 1893. His research centered on the chemical analysis of various Japanese and Chinese traditional herbal medicines. While in Germany, Nagai married Therese Schumacher, the daughter of a wealthy lumber and mining magnate. On their return to Japan, she became a professor of German language at Japan Women's University, and was active in introducing German foods and culture to Japan. In 1923, Nagai and his wife hosted Albert Einstein and his wife during their visit to Japan. His son, Alexander Nagai, served as a diplomat at the Embassy of Japan in Berlin until the end of World War II. As first president of the Pharmaceutical Society of Japan (PSJ, founded in 1880); Nagai had an important impact on the propagation of chemistry and pharmaceutical sciences in an industrializing Japan.

Death Nagai died in 1929 in Tokyo of acute pneumonia.

Scientific contributions Isolation of ephedrine from Ephedra vulgaris in 1885. Nagai recognized it to be the active component of the plant. Synthesis of methamphetamine from ephedrine in 1893. Methamphetamine was later synthesized in crystalline form in 1919 by Akira Ogata. Isolation of rotenone from Derris elliptica in 1902. Nagayoshi named the substance after the Japanese name for the plant, roten. Synthesis and structural elucidation of ephedrine in 1929.

References Lock, Margaret. East Asian Medicine in Urban Japan: Varieties of Medical Experience. University of California Press; Reprint edition (1984). ISBN 0-520-05231-5 Schultes, Richard Evans, ed. Ethnobotany: The Evolution of a Discipline. Timber Press, Incorporated (2005). ISBN 0-931146-28-3 W Pötsch. Lexikon bedeutender Chemiker (VEB Bibliographisches Institut Leipzig, 1989) ISBN 3-8171-1055-3 Specific

External links Pharmaceutical Society of Japan Museum of the Tokyo Pharmaceutical Association (Japanese)

Illustrations

Nagai Nagayoshi illustration

Worked examples

Example 1 — a first encounter with Nagai Nagayoshi

Start with the simplest possible case. Write down what Nagai Nagayoshi claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nagai Nagayoshi before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nagai Nagayoshi ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nagai Nagayoshi

In research
Nagai Nagayoshi appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Nagai Nagayoshi in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Nagai Nagayoshi is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1844 births, 1929 deaths, 19th-century Japanese chemists, so understanding it makes those chapters shorter.
In everyday life
Look for Nagai Nagayoshi outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Nagai Nagayoshi in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Nagai Nagayoshi means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Nagai Nagayoshi out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nagai Nagayoshi in simple terms?

Nagai Nagayoshi (長井 長義; August 8, 1844 – February 10, 1929) was a Japanese doctor of pharmacy and chemist. He is best known for the discovery of ephedrine and methamphetamine.

Why does Nagai Nagayoshi matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nagai Nagayoshi?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nagai Nagayoshi.

Tags

  • 1844 births
  • 1929 deaths
  • 19th-century Japanese chemists
  • 20th-century Japanese chemists
  • Japanese expatriates in Germany
  • Japanese inventors
  • Japanese organic chemists
  • People of the Meiji era
  • Scientists from Tokushima Prefecture
  • University of Tokyo alumni

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