chemistry

Samuel Lewis Penfield

Samuel Lewis Penfield 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 Samuel Lewis Penfield rather than just read about it. In short: Samuel Lewis Penfield (January 16, 1856 – August 12, 1906) was an American analytic chemist, mineralogist, and crystallographer who first obtained the chemical structures of more than two dozen naturally occurring minerals. Biography Penfield prepared for college at the Catskill Academy and the academy at Wilbraham, Massachusetts.

Key takeaways

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

Reference excerpt

Samuel Lewis Penfield (January 16, 1856 – August 12, 1906) was an American analytic chemist, mineralogist, and crystallographer who first obtained the chemical structures of more than two dozen naturally occurring minerals.

Biography Penfield prepared for college at the Catskill Academy and the academy at Wilbraham, Massachusetts. He matriculated at Yale in the Sheffield Scientific School in 1873, graduating with honors in 1877 and becoming a scientific assistant in chemistry and in mineralology. Except for brief periods abroad, in Germany (where he trained in crystallography), his entire subsequent career was to be at Yale. In early work, He analyzed the then-new so-called Branchville phosphates, fairfieldite and fillowite, as well as samples of chabazite and rhodocrosite from the same locality. He was soon known as expert in analyzing minerals containing fluorine. Penfield became assistant professor of mineralogy in 1888, and was advanced to full professorship in 1893, soon taking charge of the mineralogical department. Among minerals whose chemical composition he was instrumental in elucidating (often in collaboration with others) were the new minerals Nesquehonite, Canfieldite, Pearceite, Clinohedrite, Hancockite, Glaucochroite, Graftonite, as well as known minerals that existed in samples but were unanalyzed: Monazite, Herderite, Howlite, Connellite, Aurichalcite, Argyrodite, Cookeite, and a long list of others, including notably Turquoise in which the occurrence of copper in this phosphate was explained. Of eighteen minerals that he discovered and named, just two were later shown to be duplications of ones previously discovered. Penfield's scientific work may be summarized as comprising mineralogical investigations of great abundance, variety, accuracy, and importance. The thoroughness with which his work was carried out is also particularly striking. In some cases, he was able to predict the existence of minerals not yet discovered. Penfield insisted on careful purification of every mineral he analyzed and gave a full statement in each of his papers of just what purification procedure he used. He often checked his methods by the analysis of material of known composition. His honorary memberships included Fellow of the American Academy of Arts and Sciences (1893), Foreign Correspondent of the Geological Society of London (1896), Member of the National Academy of Sciences (1900), Fellow of the American Association for the Advancement of Science, Corresponding Member of the Royal Society at Göttingen (now Göttingen Academy of Sciences and Humanities), Member of the Scientific Society at Christiania (now the Norwegian Academy of Sciences, 1902), Corresponding Member of the Geological Society at Stockholm, and Foreign Member of the Mineralogical Society of Great Britain (1903). Penfield remained unmarried for twenty years after his graduation from college and lived in an apartment in South Sheffield Hall. He was married in 1897 and died in 1906.

References

Worked examples

Example 1 — a first encounter with Samuel Lewis Penfield

Start with the simplest possible case. Write down what Samuel Lewis Penfield 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 Samuel Lewis Penfield 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 Samuel Lewis Penfield 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 Samuel Lewis Penfield

In research: Samuel Lewis Penfield 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 Samuel Lewis Penfield 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: Samuel Lewis Penfield is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1856 births, 1906 deaths, American chemists, so understanding it makes those chapters shorter.
In everyday life: Look for Samuel Lewis Penfield 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 Samuel Lewis Penfield in 20 minutes

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

Frequently asked questions

What is Samuel Lewis Penfield in simple terms?

Why does Samuel Lewis Penfield 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 Samuel Lewis Penfield?

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 Samuel Lewis Penfield.