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Encyclopaedia Britannica: A Neglected Phlogistonist "Textbook". Ralph W. Gable. Dauidson College. Dauidson, North Carolina 28036. Chemistry before the...
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JOHN H. WOTlZ

Southern Illinois University Carbondale, Illinois 82901

Encyclopaedia Britannica: A Neglected Phlogistonist "Textbook" Ralph W. Gable Dauidson College Dauidson, North Carolina 28036 Chemistry before the Oxygen Revolution was differentbut how different? It is quite possihle for even a lihrary of modest means to provide an extraordinarily clear first hand vxposition of the state of thisscience immediate~ypreceding the revolution wh~chwas iniriatcd hy Antoine I.avt~isier's "'I'ratlE Elcrncntnrre de Chtmie" I I ). rommonlv considered to he the first modern chemical text'book.' "TraitP" is readilv available in reprints, hut earlier textbooks, with which itmight he cornpired, are not. Such puhlications as the Alembic Club reprints of important works can pro\,itlc studenw with needed eiposure 1,) c&emporary ideas on chcmical problems of previous timw, hut these individual works sufferfrom a lack bf the comprehensive view which is commonly provided by textbooks. Such com~rehensiveapproachesiothc older chemistry are invaluahfe to anyune interested in understanding the true natnre and extent of the centurv. chemical revolution of th;? last of the eiehteenth ~~~~-~ " One accessible example of a pre-Lavoisier phlogistonist chemistrv is found in the first edition of the "Encvclooaedia ~ r i t a n n i c a "(6), antedating "Traite?" hy 18 yeak2-1n attempting to avoid the fragmentation which plagued earlier encyclopedias such as those by Chambers (7) and Diderot (8). it presents its 118 page "chemistry" entry as atexthook would. The two major divisions are "Part I, Theory of Chemistry" and "Part 11, Practice of Chemistry." The point of view is, of course, phlogistonist; although portions, such as the introductory paragraph, have a surprisingly modern ring. ~

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Thpobject ofand chwf md uf chemistry is toseparate thedifferent auhstanre, that rntpr into thenmpasicion of hditr; toexamineroeh ot thrm ialmrt; I*)discover their pmpenies and relations; tn dmmlxae those very substances, if possible; to reunite them again into one body, so as to reproduce the original compound with all its properties; or even to produce new compounds that never existed among the works of nature, from mixtures of other matters differently combined. Elements, or principles, are defined as suhstances which cannot be further resolved into others. Earth, water, air, and fire are then identified as the principal substances of this sort. For though there he reason to think, that these are not the first commnent oarts. . . or the most simole elements. of matter:..vet..as we know bv exoerience. that our senses cannot &ssihlv discover the . ~~,~ ~, principles ui uhirh they themsdves are ctrmpored, it secrna mure rrasonnhlr t*, fix upon thrm and consider thrm as simple homyy neuw bodirs; and the principle*ofche rest, than to tireourmrndiuith vain conjectures about the partsor elements of which they may eonsist. ~

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l'hlogiston is clearly distinguished from "pure and unfixed fire" in several ways. It gives a hods neither heat nor light when united to it. It d(ns not cause a change in the solidity or

fluidity of a hody. It is a part of the composition of a hody and can he conveyed from one hody to another. The author does not claim to "understand" it but accepts i t from a pragmatic pomt of view. By what mechanism then is this fluid, so subtile, so active, so difficult to confine, so capable of penetrating into every other substance in nature, so fixed as to make a component part of the most solid bodies? It is no easy matter to give a satisfactoryanswer to this question. But, without oretendine to mess the cause of the ohenomenon. let us rest cvnlrnr&lwnh thtrendinty ofrh?tact, the kntrul