chemical 
weights of the resultant ralrinm ntrlxinate and sodium 
chlorid. Chemical equivalent, extinguisher, fer- 
ment, fire-engine, etc. .See the i minis. Chemical 
force, the force which binds together the atoms in a 
molecule, ami causes chemical changes when dissimilar 
molecules nru linuiKlit within the sphere of its action un- 
der proper conditions. Chemical formula, a symbolic 
expression used to represent the composition of a sub- 
stance. In the formulas now generally adopted hychcm 
Ms each elementary substance is indicated by the first let- 
ter or letters of its name, called its chemical symbol ; and 
to express the compounds of the elements, their symbols 
;uv arranged together, each denoting a single atom, and 
M. ill numbers are written after a syml>ol and a little be- 
low (sometimes, and formerly always, above) the line, in- 
dicating h- many atoms of the element exist In the 
compound. Tims, II means 1 atom of hydrogen ; Il._>o 
means 2 atoms of hydrogen united with 1 of oxygen, form- 
inn the compound water; Kilo means 1 atom of potas- 
sium (kalium), 1 of hydrogen, and 1 of oxygen, form- 
ing the compound potassium hydrate; and so on. If a 
number is placed at the beginning of the formula, it 
multiplies the entire formula like an algebraic coetlirH-ii! ; 
thus, -JII-jO int-ans 2 parts or 2 molecules of water. Ho, 
too, a small number placed after a parenthesis multiplies 
the portion included; thus, Ca.-jtl'oA, denotes :s atoms 
of calcium combined with 2 equivalents of the radical 
1'O.j, forming tricalcium phosphate or hone phosphate. 
Chemical formulas are of two kinds, I'mjiiriral and >->ttinit- 
al. An empirical formula expresses simply the relative 
number of atoms of the elements present ; a rational for- 
mula expresses not only the relative number of atoms, but 
also some conception of the mode of union of the atoms, 
the groups of radicals contained in the substance, the 
class to which it belongs, etc. Thus, the empirical for- 
mula of acetic acid is ('.jfl.iOy. Its rational formula (CH^ 
('<>. OH) indicates that it maybe regarded as made up of the 
radicals methyl (<:H :! ), carbonyl (CO), and hydroxyl (OH), 
and so suggests to the chemist many of its properties and 
reactions. See </m/</m: formula, under graphic. Chem- 
ical harmonlcon, hygrometer. See the nouns. 
Chemical kinetics, the science which treats of the phe- 
nomena of Ikxlies or systems of bodies when chemically 
active. Chemical match. See match. Chemical 
paper, paper used or suitable for use in the operations 
of chemistry, as litmus paper, etc. Chemical rays of 
the spectrum. Nee ; vfi. Chemical statics, the 
science which treats of the phenomena exhibited by chem- 
ical Itodies or systems of bodies in equilibrium. 
II. . A substance produced by a chemical 
process ; a chemical agent prepared for scien- 
tific or economic use: as, the manufacture of 
chemical*. 
cheraicaled (kem'i-kald), a. [< chemical, n., + 
-erf 2 .] Treated or impregnated with chemicals. 
[Rare.] 
Washing compounds and soap recommended to be used 
in cold water ... are highly chemicaled. 
Harper's Mag., LX1X 3. 
chemically (kem'i-kal-i), adv. In a chemical 
manner ; according to chemical principles ; in 
a chemical sense; by a chemical process or 
operation : as, a chemically active substance ; 
a surface chemically clean. 
chemick, a. and n. See chemic. 
chemico-algebraic (kem"i-ko-al-je-bra'ik), a. 
Relating at once to the modern theory of chem- 
istry (valency, bonds, etc.) and to the alge- 
braical theory of invariants and other concom- 
itants. 
chemico-electric (kem'i-ko-e-lek'trik), a. De- 
pending on electric activity produced by chemi- 
cal means. 
chemicogalvanic (kem"i-ko-gal-van'ik), a. 
Same as chcmieo-electric. 
chemicograph (kem'i-ko-graf),. [< Nli.chemi- 
cus, chemic, + Gr. yp&peiv, write.] A diagram 
representing the constitution of a chemical 
substance by means of bonds connecting sym- 
bols of the atoms. See bond 1 , 11. 
chemicotechnical (kem'i-ko-tek'ni-kal), a. 
Related to or depending on technical applica- 
tions of chemical science : as, the chemicotech- 
nical industries. 
chemics (kem'iks), n. [PI. of chemic: see -ics. 
Of. Sp. qwimica = Pg. It. chimica ((. NL. 'chimi- 
ca), chemics, chemistry, prop. fern, of the adj. : 
see chemic, a. and .] Chemistry; chemical 
phenomena. [Rare.] 
The laws of Gravitation, Statics, Acoustics, Chrmict, 
etc., etc., . . . these are all reducible to numerical lan- 
guage. Boardman, Creative Week, p. 310. 
chemiglyphic (kem-i-glif'ik), a. [< chemi(c) 
+ Gr. -yAtyeiv, engrave, + -ic.] Engraved by 
chemical action. 
chemin-de- 
ronde (F. pron. 
she - man de - 
r6nd'), n. [P.: 
chemin, road, 
way ; de, of ; 
roinl, round.] In 
medieval milit. 
urcli., a continu- 
ous footway up- 
on the top of the 
ramparts, pro- Chemin-de-ronde. Visigothic wall, Car- 
*li cassonne, France. ( From Viollet-le-Duc's 
tCCtCQ by tllO " Diet, del' Architecture.") 
947 
battlements, and affording means of communi- 
cation between towers and bastions. In tho ear- 
lier castles the system of defense adopted involved almost 
complete separation of each tower or post from the others, 
and tin- <//. >:>/ >l>--i-uti<li: was intercepted by each of these ; 
this caused the loss of many fortresses, a sudden attack 
often shutting up the defenders in their isolated posts. 
The castles of the fourteenth century were free from this 
defect, the ctti'iitin-tte-roiul'' becoming spacious and unin- 
terrupted, so that the garrison could be massed readily at 
any point. 
chemise (she-mez'), . [< F. chemise, < LL. 
riiiiiixia, ML. ctimisa, a shirt, a thin dress: see 
colitis, which is the older form, with the more 
general sense.] 1. A shift or undergarment 
worn by women; a smock. 2. A short, loose- 
fitting gown worn by women in the early part 
of the nineteenth century. 3. la fort. : (a) A 
wall built parallel to and outside of the main 
wall of a fortress, or concentric with and sur- 
rounding a tower, intended to prevent the ap- 
proach of sappers to the foot of the main de- 
fense. A postern in the latter provides for the access 
of defenders to the chemise and of their retreat in case it 
is stormed, (ft) The space between the chemise- 
wall and the main work which it protects, some- 
times covered with a penthouse roof. 4. A 
sleeve or an envelop of sheet-iron placed on a 
mandrel to receive the coils of steel ribbon used 
in making shot-gun barrels. In the Belgian bar- 
rels this sleeve remains to hold the coils in place upon the 
withdrawal of the mandrel. 
5f. Any covering or envelop, especially one of 
flexible material, as the parchment bag 111 which 
seals of wax were inclosed. Fire-chemiset, a piece 
of linen cloth steeped in a composition of petroleum, 
camphor, and other combustible matters, formerly used at 
sea to fire an enemy's vessel. Rectal chemise, an instru- 
ment for tamponing the rectum. It consists of a large 
catheter, the end of which is passed through the middle 
of one or more pieces of cloth, and fastened. It is then 
introduced into the rectum, and the space between the 
catheter and it* envelop is packed withpledgets of cotton. 
chemisette (shem-i-zef), [F., dim. of che- 
mise.] 1. A garment for covering the neck, 
made of some light fabric, as lace, muslin, or 
cambric, and worn under a waist, especially un- 
der one cut low at the throat. 2. In medieval 
fort., a chemise covering a very small part of 
the main wall. 
chemism (kem'izm), n. [< chem(ical) + -ism.] 
Chemical power, influence, or effects. 
The animal organism transfers solar heat and the chem- 
ixiii of the food (protoplasm) to correlated amounts of 
heat, motion, electricity, light (phosphorescence), and 
nerve-force. E. D. Cope, Origin of the Fittest, p. 190. 
chemist (kem'ist), n. [Formerly also spelled 
chymist (= F. chimiste = Sp. quimista, etc.); 
short for alchemist, alchymist : see alchemist, 
and cf. chemic, n.] If. An alchemist. 
The starving chemist in his golden views 
Supremely blest. Pope, Essay on Man, li. 269. 
2. A person versed in chemistry; one whose 
business is to make chemical examinations or 
investigations, or who is engaged in the opera- 
tions of applied chemistry. 3. Loosely, one 
who deals in drugs and medicines. chemist 
and druggist, in Great Britain, one who is registered 
as such under the act of July 31st, 1868, relating to the 
sale of poisons. Chemists and druggists are eligible as 
members of the Pharmaceutical Society, but are not en- 
titled to a place on the register as pharmaceutical chemists. 
Pharmaceutical chemist, a person acquainted with 
the chemistry of drugs; one engaged in the practice of 
chemistry in its relation to pharmacy; in Great Britain, 
a person who. after passing an examination in Latin, 
botany, mat. -via medica, and pharmaceutical and general 
chemistry, with other cognate subjects, is registered as 
such by the Pharmaceutical Society of Great Britain. 
chemisticalt (ke-mis'ti-kal), a. [< chemist + 
-ic-al.] Relating to chemistry. Burton. 
chemistry (kem'is-tri), n. [Also recently chy- 
mistry, by apheresis for earlier alchemistry, al- 
chymistry; now regarded as < chemist + -ry : 
see chemist, alchemy, and alchemistry. Other 
names for the science are chemics and chemy : 
see these words.] The science of the compo- 
sition of material things and the changes which 
they undergo in consequence of changes in 
their ultimate composition, it regards all sub- 
stances as made up of atoms (see atom) which are indivis- 
ible and have certain unchanging properties. An elemen- 
tary substance consists of groups of chemically united 
atoms of the same kind ; a compound substance, of groups 
of chemically united atoms of two or more different Kinds. 
All compound substances, and most elementary ones, con- 
sist of definite groups of chemically united atoms which 
are called molecule*. Each molecule has exactly the same 
chemical composition and properties as the whole mass 
of the substance, and is the smallest mass into which the 
substance can be divided without losing its identity. The 
laws, causes, and effects of changes in the kind, and the num- 
ber and arrangement, of atoms within the molecule are the 
subject-matter of the science. See chemical. Agricultu- 
ral chemistry. See agricultural. Analytical chem- 
istry. See analytical. Applied Chemistry. Same as 
practical chemistry. Medical chemistry, that depart- 
cheng 
ment of chemistry which has direct and intimate relations 
to the medical art, including physiological and pharma- 
c. utiral chemistry. Metallurglc chemistry. ^<< //-/ 
nlluf.iic.- Organic Chemistry, formerl> defined as the 
chemistry of those substances which arc the product* of 
vital force, which are produced by oryani/e.l hriugs, but 
rannot be artiticially prepared ; lint shire many of them 
have been prepared m the laboratory from inorganic 
materials, the term has lost its original mcauinp. and is 
mt\v applied to the chemistry of all the carl>"ii CMMI- 
poiinds. Physiological chemistry, the chemistry of 
the tissues and functions of animals and plants. - Prac- 
tical Chemistry, the application of chemical laws t<i the 
arts; the preparation of chemical con >i omuls, their analy- 
sis, and their use in arts and manufactures. Also called 
i//./,/.../ rii,-i,ii.ffii. Theoretical chemistry, the study 
of the general laws governing chemical action, ami of their 
bearing on tlie theories of matter. - Thermal chemistry, 
or thermo-chemlstry, treats of the pbenomwuruid las 
of the development and disappearance of heat induced by 
chemical reactions. 
chemitype (kem'i-tip), n. [< chcuii(riil) + ti/jie.] 
A process for obtaining casts in relief from en- 
gravings. A polished zinc plate Is covered with an 
etching-ground, on which the design is etched with a 
|toint and bitten in with dilute atjua fortis. The etching- 
ground is then removed, and every particle of the acid well 
cleaned off. The plate is covered with tilings of a fusible 
metal, and heated until the metal has melted and filled 
the engraving. When cold it is scraped away to the level 
of the zinc plate in such a manner that none of it remains 
except what has entered the engraved lines. The plate 
is next submitted to the action of a weak solution of 
muriatic acid ; and, as the one of these metals is negative 
and the other positive, the zinc alone is eaten away by the 
acid, so that the fusible metal which has entered the hol- 
lows of the engraving is left in relief, and may be printed 
from in a press. Chemitype is particularly adapted for 
the production of maps. 
chemitypy (kem'i-ti-pi), n. Same as chemitype. 
chemolysis (ke-mol'i-sis), . [< chem(ic) + Gr. 
/imf, solution, < Mctv, solve.] The analysis or 
separation of a compound into its constituent 
parts by chemical means ; chemical analysis. 
chemolytic (kern - o - lit ' ik), a. [As chemolyxis 
(-lyt-) + -ic.] Of or pertaining to chemolysis, 
or chemical analysis. 
chemosis (ke-mo'sis), n. [NL., < Gr. xfyl, a 
yawning, gaping (see cheme), + -osis.] In 
pathol., infiltration, usually inflammatory, of 
the conjunctiva and of the cellular tissue con- 
necting it with the eyeball, in which the con- 
junctiva rises up to a considerable height 
around the cornea. Also chymosis. 
chemosmosis (kem-os-mo'sis), n. [< chem(ic) + 
osmosis.] Chemical action transmitted through 
an intervening membrane, as parchment, pa- 
per, etc. 
chemosmotic (kem-os-mot'ik), a. [As ckemos- 
mosis (-mot-) + -ic.] Pertaining or relating to 
chemosmosis. 
chemy (kem'i), n. [= F. chimie = Sp. qtiimia = 
G. cnemie, etc., chemistry. < ML. chimia, al- 
chemy, the same, without the prefix (orig. art.), 
as alchimia, alchemy : see alchemy. Cf . chemics 
and chemistry.] Chemistry. Dr. G. Cheyne. 
[Rare.] 
Chen (ken), n. [NL. (Boie, 1822), < Gr. xw = 
L. anger = E. goose, q. v.] A genus of Anse- 
rince; the snow-geese. The lamella; of the bill are 
conspicuous by reason of the divergence of the edges of 
Snow-goose (Cktn hyperboreits), 
the mandibles, and the plumage is generally white, with 
black tips on the wings. C. hyperbornu inhabits north- 
erly regions of both hemispheres. 
Chena (che'n&), . [Hind.] A fresh-water fish 
of the family Ophiocephalida;, Ophiocephalus 
striatus, found especially in swamps and grassy 
tanks in India. It attains a length of 3 feet or 
more. 
chenar-tree, n. See chinar-tree. 
chendi (chen'di), n. [E. Ind.] In India, a 
drink made of the fermented juice of the date- 
palm. Simmonds. 
chenet, . An obsolete form of chiiie 1 . 
chenevixite (shen 'e-vik-sit), n. [After the 
British chemist and mineralogist Richard Chen- 
mix (1774-1830).] An arsemate of copper and 
iron, occurring massive, of a dark-green color. 
cheng (shung), n. Same as sawj/ 2 . 
