368 HISTORY OF SCIENCE. 



called " oxygenated muriatic acid." This supposition appeared to be 

 completely confirmed by some of the known properties of chlorine. 

 For example, it was known that when water saturated with chlorine 

 was exposed to the sunshine, oxygen gas was given off and muriatic 

 acid reproduced. 



The principle of giving chemical substances such names as will 

 express their composition was first definitely propounded in 1782 by 

 a French barrister named GUYTON DE MORVEAU, who devoted his 

 leisure to the study of chemistry. Lavoisier at once recognized the 

 value of this principle, and Morveau on his side became a convert to 

 the new anti-phlogistic doctrines of Lavoisier. As might have been 

 expected, the old and accepted phlogistic doctrine was not without 

 defenders, but the obstinacy with which some of these resisted con- 

 viction recalls the pertinacity of the opponents of the Copernican 

 planetary system. Macquer declared that rather than adopt the new 

 ideas he would renounce the science altogether, and other chemists, 

 even in France, offered a strenuous opposition ; but at a meeting of 

 the Academy of Sciences in 1785, Berthollet, one of the most emi- 

 nent of the French chemists, declared himself a convert to Lavoisier. 

 Fourcroy, who was the Professor of Chemistry at the Jardin des 

 Plantes, and others, soon afterwards did the same. Lavoisier, Mor- 

 veau, Berthollet, and Fourcroy combined together in the composition 

 of a treatise on the nomenclature of chemistry, which was published 

 in 1787. Lavoisier and his coadjutors also established a monthly 

 journal, the " Annales de Chemie" in which only the new nomencla- 

 ture was employed. The eminence of the editors and the great value 

 of the papers which appeared in this journal secured for it the atten- 

 tion of chemists everywhere, so that the new nomenclature was soon 

 made known in every civilized country. The English chemists no 

 doubt in some degree affected by the general British determination to 

 oppose all French innovations almost to a man clung to their beloved 

 phlogiston. Cavendish published an able defence of the old theory, 

 but finding that the new opinions were nevertheless gaining ground, 

 he relinquished chemical studies altogether. Priestley died in the phlo- 

 gistic faith, and other British chemists imitated Cavendish by throwing 

 up the study in disgust. One of the stoutest defenders of phlogiston 

 was an English chemist named KIRWAN (1750 1812), a man of de- 

 servedly high reputation. He published a very elaborate defence of 

 the phlogistic doctrines, in which he sought to identify the phlogiston 

 of Stahl with inflammable air (/>., hydrogen gas). According to 

 Kirwan's essay, " inflammable air " is a constituent of charcoal, sul- 

 phur, and all metals, and when these are burnt it escapes from them 

 and enters into new combinations. This modification of the phlogistic 

 theory was at first favourably received by many British and continental 

 chemists ; but Lavoisier and his confederates translated the " Essay on 

 Phlogiston" into French, and published it with a complete refutation 



