DISSERTATION THIRD:

EXHIBITING A GENERAL VIEW

OF THE

PROGRESS OF CHEMICAL PHILOSOPHY,

FROM THE EARLY AGES TO THE END OF THE

EIGHTEENTH CENTURY.

BY WILLIAM THOMAS BRANDE,

SECRETARY OF THE ROYAL SOCIETY OF LONDON, FELLOW OF THE ROYAL SOCiety of Edinburgh,
PROFESSOR OF CHEMISTRY IN THE ROYAL INSTITUTION OF GREAT BRITAIN, AND

PROFESSOR OF CHEMISTRY AND MATERIA MEDICA TO THE
SOCIETY OF APOTHECARIES OF THE

CITY OF LONDON.

DISSERTATION THIRD.

SECTION I.

GENERAL VIEW OF THE PROGRESS OF CHEMICAL SCIENCE, FROM THE EARLY AGES TO THE END OF THE SEVENTEENTH CENTURY.

THE phenomena of the universe present a series of changes, of which the regularity and harmonious succession excite the surprise of superficial observers, and awaken the admiration and attention of the philosophic mind.

These changes are either accompanied by visible motion susceptible of measurement, and relate to the exterior forms and mechanical characters of bodies, or they depend upon the mutual agencies of the elementary principles of matter, upon its composition, upon its susceptibility of acquiring new properties by entering into new combinations.

The investigation of the former phenomena belongs to the mechanical philosopher; to trace the causes of the latter, and to discover the laws to which they are obedient, is the business of chemical science.1

1 Definitions of Chemistry." La Chymie est un art qui enseigne à separer les differentes substances qui se rencontrent dans un mixte." (L'Emery, Cours de Chymie.)

"Chemistry is that science which examines the constituent parts of bodies, with reference to their nature, proportions, and method of combination." (Bergman, Essay on the Usefulness of Chemistry.)

"Chemistry is the study of the effects of heat and mixture, with a view of discovering their general and subordinate laws, and of improving the useful arts." (Black, Lectures.)

"La Chimie est une science qui apprend à connaitre l'action intime et réciproque de tous les corps de la nature, les uns sur les autres. Par les mots action intime, et reciproque, cette science est distinguée de la

1

Chemistry, considered as a branch of scientific inquiry, is not of ancient date. 1 Founded upon principles deduced from experiment and observation, centuries were

physique experimentale, qui ne considère que les propriétés extérieures des corps doués d'un volume, et d'une masse quon peut mesurer, tandis que la Chimie ne s'attache qu'aux propriétés intérieures, et n'agit que sur des molécules, dont le volum eet la masse ne peuvent pas être soumis aux mesures et aux calculs." (Fourcroy, Systême des Connoissance Chimiques, Vol. I. p. 4.)

"Die Chemie ist eine Wissenschaft die uns die wechselseitige wirkungen der einfachern Stoffe in der Natur, die zusammensetzung der körper aus ihren und nach ihren verschiedenen verhältnissen, und die Art und Weise kennen lehrt, sie zu trennen, oder sie wieder zu neuen Körperarten zu verbinden." (Gren. Systematisches handbuch der Chemie, p. 1. Halle, 1794.)

"Chemistry is that science which treats of those events or changes in natural bodies, which are not accompanied by sensible motions." (Thomson, System of Chemistry, fifth edition, p. 2.)

Most of the substances belonging to our globe are constantly undergoing alterations in sensible qualities, and one variety of matter becomes, as it were, transmuted into another. Such changes, whether natural or artifical, whether slowly or rapidly performed, are called chemical;-thus the gradual and almost imperceptible decay of the leaves and branches of a fallen tree exposed to the atmosphere, and the rapid combustion of wood in our fires, are both chemical operations.

"The object of chemical philosophy is to ascertain the causes of all phenomena of this kind, and to discover the laws by which they are governed." (Davy, Elements of Chemical Philosophy, p. 1.)

In the edition of Johnson's Dictionary, now publishing by the Rev. H. J. Todd, the erroneous and antiquated definition of Boerhaave is very improperly retained. "An art whereby sensible bodies contained in vessels, or capable of being contained therein, are so changed by means of certain instruments, and principally fire, that their several powers and virtues are thereby discovered, with a view to philosophy or medicine."

The derivation of the word Chemistry can scarcely be said to have been ascertained. The most plausible guesses are the following: from w to melt, or xos juice; from kema, an oriental word signifying black; from us, the name of a person eminently skilled in the sciences; from Chemi, the Coptic name of Egypt, where the art is supposed to have had its rise.

According to Bryant (Ancient Mythol.), it is derived from chemia, and that word from Cham.

The Rev. Mr Palmer, Professor of Arabic at Cambridge, has given the following etymology: "Al-chemy, or more properly Al kemy, the knowledge of the substance or composition of bodies, so named from the substantive (Kyamon), that is, the substance or constitution of any thing; from the root (Kama). Golius. Lexicon." (Thomson's Chemistry, 5th edit. p. 4. Note.)

Conversing upon this subject with Dr Thomas Young, he remarked, that the Egyptians probably neither knew nor cared much about the composition of bodies; and that the term Chemistry, as referring to the secret art of transmutation, was probably derived from the Coptic root hhems or chems, signifying obscure, dark. The German word geheim, secret, he said, was perhaps of the same root.

"Hæc ars varia accepit nomina, nam omnium primò dicta fuit rx Tonin, et antiquis illis temporibus per hanc vocem significabant artem vilia metalla in aurum convertendi, et ejus artifices oral vocari Zozimus dicit. Veteres Ægyptios hanc artem Chimoet vocasse Josephus Scaliger ibi ostendit, sed postea Græci hanc artem xguono dixerunt, Arabibus vero, Alchemia." (Boerhaave, Institutiones Chemic.)

1 "Tout ce qu'on a dit de l'antique origine de la Chimie, sur les premiers hommes qui ont travaillé les metaux, taillé et poli les pierres dures, fondu les sables, dissous et crystallisé les sels, ne montre à un esprit exact et sévère qu'une vaine et ridicule pretension, semblable à cette par laquelle on voudrait reconnoître

consumed in their accumulation and systematic arrangement; but, as an art, chemistry is readily traced to periods of remote antiquity; for it is obvious that the chemical changes of matter must have been rendered subservient to the wants of mankind in the earliest ages of the world.

Metallurgy is among the most ancient of the arts, and Tubal Cain, the instructor of workers in iron and brass, has thence been called the inventor of chemistry. Others have preferred the claims of Noah, to whom the invention of wine has been attributed; but these, and other arts alluded to in Sacred Writ, such as dyeing, gilding, and embalming, which have been adduced as instances of chemical knowledge in the time of Moses, prove nothing more than that such processes were practised at that period, independent of each other, and quite unconnected by the slightest reference to general principles. 1

1

It is probable that the early mythological systems of the Egyptians contained some allusions to the chemical changes of matter, and to them the first speculations on the art of transmutation have been attributed. Hermes, or Mercurius Trismegistus, the favourite minister of the Egyptian king Osiris, has been celebrated as the inventor of this art, and the first treatise upon it has been attributed to Zosymus, of Chemnis or Panopolis in Egypt. The inhabitants of Sydon and Tyre, those renowned seats of the commerce of the ancient world, seem to have been skilled in some chemical manufactures; they made glass and artificial gems, and excelled in dyeing purple.

Egypt maintained its superiority in arts until the invasion of Alexandria by the Saracens, when the clebrated library collected by the Ptolemies, with great diligence and at enormous expence, was burned by the orders of Caliph Omar. The alchemical

les élémens de la géométrie dans l'ouvrage grossier du sauvage qui use les fragmens du rocher, qui leur donne des formes à peu près régulières pour les rendre utiles à ses premiers besoins." (Fourcroy, Discours Préliminaire.)

1 "Si l'on examine cependant avec courage et sans préjugé toutes les preuves qu'on a réunies pour etablir l'existence de la Chimie chez les Egyptiens, après avoir reporté son origine aux premiers âges du monde et aux prémiers travaux ou les hommes ont employé le feu comme agent, on reconnaît bientôt que tirées uniquement des products employés dans leurs constructions diverses, elles peuvent toutes annoncer des arts ou des procédés de fabrique plus on moins avancés, mais rien qui tienne à des notions générales tirées de ces arts, comparés rien qui depende d'une doctrine suivie, rien enfin qui puisse donner une idée d'une veritable science." (Fourcroy, Disc. Prél.)

2 "Qui his scriptis parcendum esse negabat, quippe quæ inutilia essent, si eorum dogmata Alcorano congruerent, noxia vero, si ab illo dissentirent." (Bergman, De primordiis Chemiæ.)