Lecture 2 - Weights & Analysis

3 Pages
Unlock Document

History and Philosophy of Science and Technology
Chen- Pang Yeang

HPS211 Lecture 2 MAY17/2012 Weight - Major topic of research during the Chemical Revolution was weight I. Origin of chemistry & alchemy - People interested in the properties of matter - Transformation of matter (i.e. salts/crystals dissolving in acidic water) - Aristotle has a theory for the cause of the transformation of matter  4 elements: Air (wet, hot), Fire (hot, dry), Earth (dry, cold), and water (cold, wet)  Combination of elements indicates a substances’ properties - Alchemy: interested in transformation of matter for not only intellectual reason but also practical reasons  The acts/skills of transforming base metals into gold (precious metal) (i.e. copper into gold)  Alchemists witnessed a lot of matter transformation (i.e. liquid to solid, etc.) Therefore, assumed the possibility of transforming base metals into gold  Alchemical 3 Principles: Mercury, Sulphur, and Salt  Employed for understanding chemical phenomena  Not necessarily in contradiction with Aristotelian elements  Abstract elements – cannot be found in our daily lives  3 principles responsible for the chemical properties of substances  Alchemy far from primitive; associated with magic, charlatan, witchcraft, etc.  Alchemy was very secretive because of its potential gain in revenue and for negative views (i.e. cheating)  Texts about alchemy were written in esoteric texts and practices  In religious (catholic) places, alchemy was called a religious heresy for its seeming association with witchcraft  Also, a threat to monetary order since there’s a possibility of transforming metal into gold.  Alchemy is a secret, private form of inquiry to nature II. Newtonian Chemistry & Phlogiston chemistry - Two alchemists/Scientific Revolutionaries: Robert Boyle and Isaac Newton  Boyle was the founder of Chemistry  Newton was a mathematician and physicist and later became interested in alchemy  They were both interested in WHY matter transform  Reformed alchemy including its means of practice  Reformed from a secretive alchemy to a more open, public kind  Alchemy  “Chymistry”  Chemistry - Copuscular Theory of Chemistry  BOYLE: Properties and transformation of matter determined by motions and configurations of constituent corpuscles  different between iron and gold – atomic configuration. Therefore, if iron`s atomic configuration can be rearranged, it can be turned into gold  NEWTON: Properties and transformation of mattth determined by forces between corpuscles  Newtonian chemistry prevailed in 18 c. in England and France  Explains displacement/ chemical affinity  Chemical Affinity:  Place copper in oil of vitriol (sulphuric acid)  copper dissolves  Place iron in the solvent  iron dissolves, copper deposits  It seems that iron has a stronger affinity that copper to oil of vitriol  Table of Chemical Affinity created by Étienne-François Geoffroy in 1718, Paris  Synthesis of empirical observation  Newtonian Chemistry: Chemical affinity indicates microscopic force – popular in France and England - A different Approach to Chemistry in Germany  Johann Joachim Becher and Georg Ernst Stahl: base study of chemistry not on Newtonian chemistry HPS211 Lecture 2 MAY17/2012  Both believed chemistry to be independent of physics, go back to alchemical system, and came up with the theory of phlogiston  Theory of Phlogiston  Cause of combustion (in general sense)  In combustion, phlogiston releases from matter to air  Combustion stops when matter runs out of phlogiston or when air is saturated with phlogiston  So after combustion, matter loses something  CLIMAX: discovery of “dephlogisticated air” (oxygen) - Joseph Priestley: nonconformist, discovered oxygen, interested in chemical studies  1774: important experimental discovery – discovery of New Air  Sun-burn red “mercury precipitate” in mercury-trough device  Generate a new air  Enable bright candle fire  Mouse survives long  Conclusion: air with greatest capacity for combustion  air with minimum density of phlogiston III. Chemical Revolution - Antoine-Laurent Lavoisier was intrigued with Priestley’s discovery  He refused the theory of phlogiston; his refutation:  From phlogiston theory, metal loses phlogiston after burning. When metal is weighed before and after burning, it gained weight. SO, metal must gain something, not lose something in the process  Metal combines with the new air of “oxygen” (acid generator)  Characteristics of Lavoisier’s Research Style  Highly quantitative, contrasting qualitative phlogiston chemist
More Less

Related notes for HPS211H1

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.