empirIcal

[Eng. empiric; -al.] The same as EMPIRIC (q. v.). empirical-formula, s. Chem: The empirical formula of a chemical substance states the result of the analysis of the body, showing the relative number of the atoms of each element contained in it. Several substances can have the same empirical formula; thus acetylene, C2H2, and benzene, C6H6, when analyzed give the same percentage of carbon and hydrogen. The numbers of the atoms of hydrogen and carbon con tained in a molecule of the substance are expre ed by their rational formula (q.v.). The relations of the atoms of the elements contained in a molecule to each other are shown by the constitutional formula, thus C3H6O is the rational formula for acetone, CH3COCH3. Propyl aldehyde is written CH3CH2COH, and allyl alcohol, H2C=CH-CH2OH. empirical-laws, s. pl . Laws founded on conformities ascertained to exist, but which have not yet been traced to any broad general principle. em-pir-Ic-al-ly, adv . [ Eng.empirical ; -ly.] *1. Experimentally, by experiment; according te experience. 2. In manner of a quack; without science. em-pir-I-çişm, s. [Eng.empiric; -ism.] 1. Reliance upon experience and observation rather than on theory. "Experience is apt to degenerate to a vulgar and pre sumptuous empiricism."-Knox: E ays, No. 88. 2. The practice of medicine without due profe ional training; quackery, charlatanry. *em-pir-I-çist, s. [English empiric; -ist.] An empiric. *ěm-pir-I-cü-tic, a . [EMPIRIC, a . ] Empirical. "The most sovereign prescription in Galen is but empiricutic."-Shakesp.: Coriolanus , ii. 1. ěm-pis', s. [ Gr.empis =a mosquito, a gnat.] Entom.: A genus of Diptera, the typical one of the family Empide (q. v.). It has a proboscis which is perpendicular or directed backward. *ěm-plā çe-ment, s . [Fr.] 1. Ord. Lang.: The place, ground, or site, as of a building. 2. Mil .: An epaulement, used in field fortification to cover a battery of field guns, usually in conjunction with a line of shelter-trench. "Behind these dark objects on the slopes, so like battery emplacements , may be lurking Krupp cannon." Daily News Correspondence .