TWO thillgs were necessary to make away with phlogiston; First, a clear knowledge of some of the ordinary gases: secondly, a clear quanti tative Of some of the ordinary (diem ieal transformations. The gases in question are ca•honie acid, oxygen. and air. _\s to quanti tative chendeal kno•ledg,e, it Call, Of cOIIIasv, 110 acquired only by the use of the balance. Ca• •onic acid was known since the time of Belmont yet chemists were not sure but that it might be impure air, until Joseph Black iso lated it and demonstrated its properties in 1755. Bergman completed the study of this gas in 1774. The presence and properties of oxygen were suspected by Boyle, Alayo• ( Ifiliff), Boer Imave. and others; but. it was first iso lated by Priestley:Ind Scheele in 1774. The nitro gen the air isolated by Rutherford in 1772. It must be remarked here that the ap paratus and manipulations. of 'imetimatie chem istry' were gradually perfected by Boyle, llales, Black, and Priestley, the lat ter having invented the method of collecting gases over which possible the isolation of gases that are soluble in water. But the precise demonstration of the composition of gases, the introduction of the systematic use of the ha lance, are due to the founder ci quantitative chemistry—the French physi cist and chemist 1..avoisier.
But before we proceed to narrate the further regress of chemical philosophy, it remains to enumerate hrictiv the most important achieve ments of chemical technology during the reign of phlogiston. in spite of its fundamental error.
chemistry was making fairly rapid progress, and this naturally told on the industries. Boyle and Kunkel improved many metallurgical processes and the manufacture of glass. The manufacture of iron and steel owed valuable improvements to the researches of Bergman. t;a1m, Rittman, and Stahl, Scheele, Ilellot, Alacquer, and others introduced new dyestuffs and im proved many processes of dyeing. The prepara tion of zinc was improved by Alarggratr, and its manufacture on a large scale was commenced at Bristol in 1713. The manufacture of sulphuric acid was commenced by Ward at Richmond; and in 1746 lead ehambers were first introduced by Roebuck. In 1747 discovered sugar in beets; however, the sugar industry was not born until the beginning of the Nineteenth Century. Early in the Eighteenth Century (1703) Bottger was accidentally led to the invention of porce lain, and its manufacture commenced at in 1710; but the processes were kept secret, and the manufacture was confined to 1\leissen until Rerunnur rediscovered them by systematic re search, and finally, in 1760, great porcelain works were established also at Siwres, near Paris. In the course of the period many substances were introduced as therapeutic agents, and Scheele discovered a number of important compounds of carbon.