The elements of medical chemistry : embracing only those branches of chemical science which are calculated to illustrate or explain the different objects of medicine, and to furnish a chemical grammar to the author's Pharmacologia . quantity of water or mercury, is pouredinto the funnel, so as to about half fill the ball. When any * This transfer of a liquid from one vessel to another, in consequenceef the formation of an imperfect vacuum, is termed absorption, and is highlyannoying to the inexperienced operator. PARIBUS MEDICAL CHEMISTRY. ioy absorption happens, the fluid rises in the ball, t
The elements of medical chemistry : embracing only those branches of chemical science which are calculated to illustrate or explain the different objects of medicine, and to furnish a chemical grammar to the author's Pharmacologia . quantity of water or mercury, is pouredinto the funnel, so as to about half fill the ball. When any * This transfer of a liquid from one vessel to another, in consequenceef the formation of an imperfect vacuum, is termed absorption, and is highlyannoying to the inexperienced operator. PARIBUS MEDICAL CHEMISTRY. ioy absorption happens, the fluid rises in the ball, till none re-mains in the tube, when a quantity of air immediately rushesin and supplies the partial vacuum in c. On the other handno gas can escape, under ordinary circumstances; becauseany pressure from within is instantly followed by the forma-tion of a high column of liquid in the perpendicular part,which resists the egress of gas. 178. Very useful modifications of this apparatus have beencontrived by Mr. Pepys,* Mr. Knight,f Dr. Murray,!Dr. Hamilton, and Mr. Burkitt-fj There is also an Americaninvention for the same purpose, which has considerable merit. §The arrangement by Mr. Pepys is represented in the The receiver b is surmounted by a vessel c accuratelyground to it, and furnished with a glass valve, which allowsgas to pass freely into the vessel c, but prevents the waterwhich c contains from falling into the receiver b. 179. Rectification. This is the repeated distillation of anydistilled product when it is not perfectly pure. This secondoperation is conducted at a lower temperature, so that themore volatile parts only are raised, and carried over into thereceiver, leaving the impurities behind. 180. Dephlegmation or Concentration. The process ofrectification is distinguished by these terms, when the fluid * Philosophical Magazine, vol. Nicholsons Journal, vol. iii. I Murrays Chemistry, and Hamiltons Translation of Berthollet obDyeing. IJ Nicholso
Size: 1946px × 1284px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectchemistrypharmaceutica, bookyear1825
