Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/540

506&#93; 5 o6] CHE itjr to these bodies, and under certain circumstances, alone capable of recovering its elasticity, and be- ting again an elastic, thin fluid, and therefore well deserving to be ited among chemical principles, r.nd to possess a rank which has to been denied it." In his admirable work, entided Vegetable j per ive the first traces ie existence of air in those wa- ters called is; and he not remarked that they contain or live times more air than but also Cw.ijrclur- ed, that they owed to it their .ess. The truth itionof this dis- . v to medical purposes, were enforced by the immor- tal Bo-eb.haa.vb, whose reputation, both ician and a philoso- (two great qualifications, not alv; : . had resounded to the remotest parts of the globe. — • Lime, the illustrious ikb. first began to collect and pare the immense store of che- ts, and arrange their rela- tione a new system. Per-, lil t be- i tors of mankind who ft rhe beaten track, he fled from his ' native country, retired to Eng- . and died of a broken heart at London in 1682, His theory, Itowever, the saga- cious and intrepid Stahl, then first physician to the King of Prussia. In the opinion of these two au- . Jire enters into the compo- B of all inflammable bodies, iiiio metals, and most minerals; and in that condensed and fixed they called it phlogiston, or t fire, to distinguish it from ■ audition, when in a free state. They farther believed that phlo- giston is actually a material body, CHE liable to be modified and infta- enced by circumstances ; and that consequently all metals were com- pounds; and water, as containing" no phlogiston, a simple body. Al- though dais vague theory has been strenuously maintained by nearly all the chemists of Europe, for up- wards of a century, and is still sup- ported by Dr. Priestley, and many of his followers in this and other countries, yet, to the honour of our age, and we venture to say, the credit of that voluntary exile, the doctrine of phlogiston is nearly exploded. To proceed in this ex- planation, according to the order of time in which the leading facts were ascertained, we shall first mention, that Dr. Black, our late illustrious professor of chemistry,, in the University of Edinbu. about the middle cf last century observed, that certain substances, such as matble, chalk, and lime- stone, when submitted to the pro- ■ of lire, lost half their former weight; and, when treated with acids, the compound weighed less before. Hence, it became nt, that something was lostj and, from a strict chemical ana- lysis, he proved this something to be a permanently e astic fluid, which he termed jixed air — de- d of which, the residue was caustic, or quick-lime, capable of corroding all animal and vegetable substances. Hitherto, the exist- ence of fixed air, and its combina- tion with bodies, was only conjec- tured, and no philosopher, sinceVAN Helmont's time, had adopted this opinion. Tims, new views were opened in the examination of all matter, and the attention of expe- rimental inquirers was principally directed to the decomposition of s.olid bodies. Dr. Fvuthf.rvobi extended