Tareas

Antoine Lavoisier
1743 - 1794Born to Wealth.  Antoine-Laurent Lavoisier was born August 26, 1743, the son of a wealthy Paris family.  His father was a lawyer who had married a daughter of the wealthy Punctis family.  Louis XV was the King of France.  Most of Europe, and especially France, was in social upheaval.  Peasants faced continual famines and peasant revolts and mob violence werecommon.  Lavoisier's family were among the upper class so Lavoisier was able to complete a degree in law at the Collège Mazarin in fulfillment of his family's wishes. | |
Science.  Lavoisier never practiced law.  At age 21 began to fulfill his own dream � to study mathematics and science.  He studied astronomy, botany and geology under eminent scientists of the time.  His work with geology and hiswinning essay on the best means of lighting the streets of a large city at night gained him an elected membership at the age of 25 into France's prestigious Academy of Sciences.
Ferme Générale.  In 1768, Priestley bought into the Ferme Générale, a private company that collected taxes for the Crown.  Owners, called 'tax farmers,' were empowered to collect taxes of all kinds, but especially duties onimported goods.  The system was easily and often abused by the tax farmers who enriched themselves and lived in extravagance.  They were the target of popular hatred among the peasants and merchants alike.  All evidence suggests that Lavoisier discharged his duties honestly and without corruption.  Lavoisier seems to have justified his involvement in the Ferme to raise money for the pursuit ofscience.
Marie-Anne Pierrette Paulze.   In 1771, Lavoisier married 13-year old Marie-Anne Pierette Paulze, the daughter of a co-owner of the Ferme.  With time, she proved to be a scientific colleague to her husband by learning English so she could translate the writings of Priestley and others and by developing skills in art and engraving.  Madame Lavoisier drew the sketches of Lavoisier'sapparatuses and laboratory, including all of the drawings in his book, Traité élémentaire de chemie.  She developed a scientific mind and was known to take lively part in discussions of writings on phlogiston and the chemical results of others.
Chemical Revolution.   Over the 20 year period 1770 - 1790, the science of chemistry experienced a revolution so fundamental and so complete that there has beennothing like it since.  The architect of the revolution was one man � Antoine Lavoisier.  Lavoisier believed that weight was conserved through the course of chemical reactions � even those involving gases.  He explained combustion (and respiration) in terms of chemical reactions that involve a component of air which he called oxygen.  His venue for the chemical revolution came in 1775, when he wasappointed Commissioner of the Royal Gunpowder and Saltpeter Administration.  As such, he was able to build a fine laboratory at the Paris Arsenal and make important connections to the scientific community of all of Europe.  One of the first chemists to adopt Lavoisier's theories was Joseph Black who taught them as early as 1784.

Oxygen and the end of Phlogiston.  In 1774, Lavoisier wasrepeating Robert Boyle's tin calx experiments from the previous century.  Boyle knew the tin gained weight as the calx was formed.  The doctrine of Phlogiston explained that phlogiston was released upon calx formation.  While modern scientists recognize the implication that this: phlogiston must have a negative weight, early phlogistonists (Becker, Stahl) were not bothered as they considered phlogistonto be something of a philosophical concept.  Later phlogistonists such as Priestley did consider phlogiston to be a material substance (Cavendish believed it to be his inflammable air, now H2) but because the theory explained so many chemical phenomena, they were able to overlook its shortcomings.  But not Lavoisier!
     Lavoisier heated tin in air in a closed vessel.  The tin increased in...