Milestones in ChemistryBoyle Began Modern ChemistryBy Ruth A. Sparrow

Early milestones in chemistry were described by Librarian Ruth A. Sparrow inthe first part of Milestones in Chemistry which appeared in the last issue. This seriesdescribes the Museum's collection of first and rare editions of Milestones of Science.—Editor's Note.

The age of modern chemistry beganwith Robert Boyle (1627-1691) , anIrish chemist. Boyle was born in theyear Bacon died, and his place in thehistory of chemistry is that of the firsttrue exponent of Bacon's method. Themost important work of Boyle is TheSceptical Chymist (London, 1661).Of it Dr. Fulton says: ". . . . one of thegreatest books in the history of scien-tific thought. It not only marks thetransition from alchemy to modernchemistry but is a plea, couched inmost modern terms, for the adoptionof the experimental method." Thisfirst edition is so rare that it is liter-ally unobtainable; there are onlytwenty-two copies recorded, and weare indeed fortunate in having such afine copy in our collection. The sec-ond edition (1680) is also a rarity.It contains nearly twice as much ma-terial as the first. It formulates thecorpuscular theory of the constitutionof matter, which finally freed chem-istry from the restrictions of theGreek concept of the four elementsand was the forerunner of Dalton'satomic theory. Sir H. E. Roscoewrites of Boyle: "It was Boyle whofirst felt and taught that chemistrywas not to be the handmaid of anyart or profession, but that it formedan essential part of the great study ofNature, and who showed that fromthis independent point of view alonecould the science attain to vigorousgrowth. He was, in fact, the first truescientific chemist, and with him wemay date the commencement of a newera for our science, when the highestaim of chemical research was acknowl-edged to be what it . is still . upheld to

be; viz, the simple advancement ofnatural knowledge."

Boyle's first work quickly estab-lished a wide reputation for him. Hisexperiments on the air pump led todeductions of the highest scientific im-portance. He first proved that air hadweight, and it was Linus's attackupon his deductions in his Experi-ments Physico-Mechanicall (1660)that brought forth (first appearing inour second edition, 1662) the firststatement of Boyle's law — that thevolume occupied by a gas is the recip-rocal of its pressure.

A contemporary of Boyle was Rob-ert Hooke (1635-1703), an Englishmathematician and natural philoso-pher, who made important observa-tions on combustion. Hooke's only im-portant work to be published duringhis lifetime was Micrographia (Lon-don, 1665). In this he expounds hisdiscovery of the real nature of com-bustion, anticipating Mayow by thir-teen years. He established the cellularstructure of plants, and the opticaldiscoveries he expounded in it greatlyinfluenced Newton.

Our collection now takes a jumpto the late eighteenth century whenwe find the phlogiston theory of Stahlfirmly established. It was due to theinvestigations of Black and Scheeleand others that the foundation of thistheory was destroyed. Joseph Black's(1728-1799) university thesis onExperiments Upon Magnesia Alba(Edinburgh, 1754) announced thediscovery of carbon dioxide. His ex-periments also showed the possibilityof inducing compounds containing theelements magnesium and calcium to

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pass through a cycle of chemicaltransformations.

Henry Cavendish (1731-1810) wasa coworker of Black. His most im-portant work was the first experimen-tal proof of the fact that when inflam-mable air (hydrogen) is burned in or-dinary air, water is produced. Thisled to a bitter controversy, and Lavoi-sier did much to clear it up and ad-vance chemical theory. Experimentson Air (London, 1784-5) was readbefore the Royal Society on January15, 1784, and was a great contribu-tion to the progress of chemistry.

Joseph Priestley's (1733 - 1804)chemical fame rests chiefly on his dis-covery and isolation of oxygen, whichas a follower of the phlogistic doctrinehe called "dephlogisticated air." Untilhis death he adhered to this theory ofcombustion, and The Doctrine of Phlo-giston Established (Northumberland,1800) is one of his most importantand rarest works. It is interesting tonote that this paper bears the imprintof Northumberland, Pennsylvania.Priestley was forced to flee Englandbecause of his politics and with diffi-culty escaped to the United States andmade his home in Pennsylvania wherehe died.

It was left for Antoine Lavoisier(1743-1794), a French chemist, how-ever, to interpret the experiments ofthese men correctly. Lavoisier siftedand collated the facts handed downto him by the phlogiston and gavecorrect explanations for many proces-ses. While he made no independentexperiments, he did however contri-bute several of the greatest treatiseson chemistry. Mithode de Nomencla-ture Chimique (Paris, 1787) first pro-pounded the principles of chemicalnomenclature, and the reform of thelanguage effected by him was an in-dispensable beginning to the reform ofthought. This new terminology wasused without change for over fiftyyears and has hccn the basis of mod-ern nomenclature.

Lavoisier's greatest work is TraiteElementaire de Chimie (Paris, 1789).This is an extremely rare book and issaid to have done for chemistry whatNewton's Principia did for physics.It is truly one of the great classics ofchemical science and forms the foun-dation of modern chemistry. It is herethat Lavoisier expounds his antiphlo-gistic theory and the principle of theindestructibility and conservation ofmatter—the basis of chemical science.It is also the first attempt made toenumerate a list of true chemical ele-ments and their compounds. The year1789, which marked the end of thephlogiston, also proved to be thedownfall of Lavoisier. It was at thetime of the French Revolution, andLavoisier was unfortunately of the oldregime; he was guillotined in 1794.

The death of Lavoisier was merelythe death of a man; his work hadbeen so revolutionary and wide thatchemistry faced the future on a muchstronger foundation. The phlogistictheory had been deposed by the oxy-gen theory.

So chemistry faced the nineteenthcentury, and in the early days of itappeared John Dalton (1766-1844),an Englishman. His NeLU System ofChemical Philosophy (Manchester,1808-1810, 1827) is one of the greatclassics of chemistry. It contains Dal-ton's exposition of the atomic theoryfor the first time. It laid the founda-tion of chemical notation by repre-senting graphically the supposed col-lations of atoms in compound bodies.This system did not come into generaluse owing to the introduction of asimpler one sometime later. At thistime there were thirty-seven elementsknown.

Sir Humphry Davy (1778-1829),an Englishman, was among the firstto investigate the question of the de-composition of water. He delivered aBakerian Lecture before the Royal So-ciety of London in 1806 at the age oftwenty-seven, which established him

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as one of the greatest scientists of hisday. The paper On Some ChemicalAgencies of Electricity (London,1807) exploded several fallacies in thetheory of electrolysis. He outlined theelectrical theory of mass action, witha description of the emergence of ionsfrom the human body under electricalinfluence. He also suggested the useof electricity in atomic disintegration.Berzelius, his greatest rival, describesthis lecture as "the most remarkableof all contributions to the theory ofchemistry." And, although Englandwas at war with France at the time,the Paris Institut awarded Davy aprize of three thousand francs for thisoutstanding contribution.

Joseph Louis Gay-Lussac (1778-1850), French chemist and physicist,discoverer of the law of volume, pub-lished Memoires de Physique at deChimie (Paris, 1807). This appearedin the year previous to the announce-ment of the law and contains manyof his important papers.

It was Amadeo Avogadro (1776-1856), an Italian physicist, who dem-onstrated the connection between Gay-Lussac's law of volumes and Dalton'satomic theory. In Essai d'une Manierede Determiner les Masses Relativesdes Molecules Elementaires des Corps(Paris, 1811), he announced the dis-covery that changes in volume whichtake place when gases combine areexplained by assuming that the mole-cules of elementary gases may becomposed of more than one atom.These conclusions had practically noeffect at the time, and it was morethan fifty years later that they weregiven due recognition.

Joseph Frauenhofer (1787-1826) ,a German physicist, announced thediscovery of absorption lines in thesolar spectrum in 1817. He also an-nounced the generally accepted spec-troscopic scale which eventually ledto the discovery of spectroscopy:Bestimmung des Brechungs-und Farb-

enzerstreunges-VermOgnes (Munich,1817).

One of the pioneers in organicchemistry was Frederich WOhler(1800-1882), a German chemist. , • Heannounced, in Ueber Kunstliche Bild-ung von Harnstoff (1828), the dis-covery of synthesizing of urea fromammonium cyanate simply by heat-ing. This was the first synthesis ofan organic compound and is gen-erally regarded as the beginning ofscientific organic chemistry.

Justus von Liebig (1803-1873), aGerman chemist, is noted chiefly asthe founder of agricultural chemistry.Die Organische Chemie (Braun-schweig, 1840) is the first formaltreatise on organic chemistry in itsapplication to physiology and pathol-ogy. It also introduced the concep-tion of metabolism.

Robert Bunsen (1811-1899), aGerman chemist, created the gas an-alysis methods of today. Gasometry(London, 1857) is a treatise on thephysical and chemical properties ofgases. Bunsen was also the inventorof the burner and the galvanic cellwhich bear his name. He was codis-coverer with Kirchoff of spectrumanalysis.

Gustav Kirchoff (1824-1887), aGerman physical chemist, and Bunseninvestigated the color and position ofthe bright spectral lines. They in-vestigated the early work of Frauen-hofer (1817) and published this class-ical discovery in spectrum analysis,Untersuchungen iiber das Sonnen-spectrum and Derchemischen Ele-mente (Berlin, 1861). This workwas destined to play an importantpart in the determination of the con-stitution of terrestrial and celestialbodies.

New elements were being discov-ered with great rapidity. In the pre-history period there were four ele-ments evident; up to the days of thealchemists only six had been added;

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the alchemists added four new ele-ments; and twenty-eight were addedduring the phlogiston era. The ageof electrochemistry brought to lightsixteen more elements, and with theintroduction of spectroscopy fourmore were added. In 1869 sixty-twoelements were known. That yearDmitri Mendeleef (1834-1907), aRussian chemist, published his firstpaper on the important principles ofthe Periodic Law — Versuch EinesSystem Der Elemente Nach IhnreAtomgewichten and ChemischenFunctionen (German edition, Leip-zig, 1869). The Periodic Law claimsthe properties of elements to be theperiodic functions of their atomicweight. Mendeleef discussed the re-lations of known elements and on thisbasis predicted the finding of furtherelements. In the eighteen years fol-lowing this announcement fourteennew elements were found; in the nextfour, five were located.

Henry Becquerel discovered theprinciple of radioactivity whichopened up an entire new field of ele-ments. From 1898, when the Curiesdiscovered polonium and radium, upto 1927, eleven new elements wereadded. It was generally accepted thatthere could be only ninety-two ele-ments, with uranium as the heaviest,and until about two years ago all ex-cept two had been discovered. Sincethat time, with new methods andequipment, chemistry has made newdiscoveries. An atom-smasher hasbeen perfected. This has made pos-sible the building up of two new ele-ments — numbers ninety-three andninety-four. This has been possibleby the bombardment of uranium by

neutrons. Element number eighty-seven has also been discovered, leav-ing only one of the original ninety-two unfound.

The history of chemistry has beenthe history of civilization. Withoutits advance, life for the most partwould be quite primitive. Chemistryhas utilized all the resources of natureto contribute to the health and wealthof the world. Since the day in 1828when WOhler announced that or-ganic compounds could be made out-side living plants and animals, chem-istry has put to use all its resourcesto make substitutes or new products.Indigo is no longer made from the in-digo plant but from a combination ofchemicals; vanilla is synthetically pre-pared; oil of wintergreen does notcome from the plant but from methyl-salicylate. These are only a few ofthe thousands of uses to which chem-istry has been applied. This branchof chemistry which has been able tobuild up artificially what in the pasthas been regarded as vital products iscalled synthetic chemistry.

Chemistry has also applied itself tothe task of salvaging waste productsand turning them into useful pur-poses. We find that the by-productsof coal, cotton, ore, and countlessother things are the basis for most ofthe common needs of life. Industrialchemistry has advanced so rapidlythat the consumer is scarcely able tokeep up with its pace. Chemistryhad its origin from the knowledge ofsmall mysteries. Chemistry of ourtimes has practically eliminated anymystery that may be attached to it,and the ends to which it may attainare unpredictable.

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