silent 
Like starry l 
Which, sparckling on tin; silent waves, docs scenic more 
bright. Spenser, F. Q., II. xii. 78. 
If you find yourself approaching to the silent tomb, Sir, 
think of me. Diclcen*, Martin Chuzzlewit. 
Silent-alarm system. Boejtow-atafiBi telegraph, under 
fire-alarm. Silent letter, a letter of a word which is not 
sounded or pronounced in the enunciation of the word, 
as the 6 in doubt, the c in victual, the d in haiulsume, the 
second of the two like consonants inebb, odd, of, etc. The 
silent letter may be wholly useless, as in the above exam- 
ples, or it may serve as an accidental or conventional index 
of the sound given to some adjacent letter : thus, the e in 
bate, mete, bite, note, mute, etc., is silent, but it indicates 
that the preceding vowel is long ; the c in indict, the g 
in tujn, the I in balm, etc., serve a similar purpose. Silent 
letters are traditional, representing sounds that once ex- 
isted iu the word, either in English or in the original 
tongue (as the p and I in psalm, pronounced in Latin 
ftttlmut, Greek ^aAjios), though often, as in this case, 
artificially restored after having been omitted (AS. sealm, 
HE. salm, saume), or have been foisted in to suit some 
false etymology or erroneous analogy, as the I in could, 
the y in foreign, the p in ptarmigan, ete. The proportion 
of silent letters in the present English spelling is about 
12J per cent. Silent spirit, distilled spirit which is 
nearly or quite destitute of flavor and odor. Compare 
silence, 4. Silent system, a system of prison discipline 
which imposes entire silence among the prisoners, even 
when assembled together. Silent Week, Holy Week. 
Also Still Week. The Silent Sister, an ironical name 
of Ireland. = Syn. 1 and 2. Silent, Taciturn, Dumb, Mute. 
Silent expresses the fact of not speaking, taciturn the 
habitual disposition to refrain from speaking. Dumb 
strictly implies lack of the organs of speech, or defect in 
them, or lack of the power of speaking, while mute im- 
plies some special cause : hence deaf-mute is thought by 
many a better name than deaf-and-dumb person for one 
who does not speak on account of deafness; an idol is 
dumb, not mute. Under figurative extension mute, dumb, 
and silent are often used outside of the lines here indi- 
cated. In such freer use there is an advance in strength 
from silent to mute and from mute to dutnb: as, silent 
from abstraction; mute with astonishment ; struck dumb 
with horror. 
II. H. 1. A sileut period. [Rare.] 
Deep night, dark night, the silent of the night. 
Shot., 2 Hen. VI., I. 4. 19. 
2. A short-circuit switch attached to an elec- 
tric alarm, which when closed prevents the 
alarm from acting. 
If the peg is removed, or axis turned, . . . the short 
circuit is broken, and the current passes through the 
coil. A switch of this kind attached to an alarm is called 
a silent. It. S. Culley, Tract. Teleg., p. 179. 
silentiaryt (si-len'shi-S-ri), n. (X LL. silentia- 
rius, a confidential domestic servant, a privy 
councilor, < L. sileiitium, stillness, silence: see 
silence.'} 1. One appointed to keep silence and 
order, especially in a court of justice or a pub- 
lic assembly. 
The silenlian/, to call attention, strikes one of them 
[columns] with his staff. 
Seebohm, Eng. Vil. Community, p. 240. 
2. A privy councilor; one sworn not to di- 
vulge secrets of state: as. Paul the Silcntiary 
(Paulus Bilentiarius), an officer of Justinian's 
court. 
Afterwards he [the emperor] sent his rescript by Eusta- 
thius, the silentiary, again confirming it. 
Barrow, Pope's Supremacy, vi. 10 (tr. from Bassiauus). 
silentious (si-len'shus), u. [= F. siJeiicieux = 
Sp. Pg. sileiicioso = It. silcn:ioso, < LL. silaitio- 
sus, perfectly still or silent, < L. sileiitium, still- 
ness, silence: see silence."] Habitually silent ; 
taciturn; reticent. [Rare.] Imp. Diet. 
silently (si'lent-li), rfr. In a silent man- 
ner ; without speech or 
noise; not soundingly 
or noisily ; mutely ; qui- 
etly. 
silentness(si'lent-nes), 
. The state or con- 
dition of being silent; 
stillness ; silence. 
The moonlight steeped in 
silentness 
The steady weathercock. 
Coleridge, Ancient Mari- 
[ner, vi. 
Silenus (si-le'nus), . 
[L., < Gr. SFMJ^OC, Si- 
lenus (see def.).] 1. 
In Gr. myth., a divinity 
of Asiatic origin, the 
foster-father of Bac- 
chus, and leader of the 
satyrs, but very fre- 
quently merely one of 
a number of kindred 
attendants in the Dio- 
nysiac thiasus. He was 
represented as a robust, 
full-bearded old man. hairy 
and with pointed ears, frequently in a state of intoxica- 
tion, often riding on an ass and carrying a cantharus or 
other wine-vessel. 
Silenus. Marble in the Glypto- 
thck, Munich. 
The Sileni and Sylvans and Fauns, 
And the Nymphs of the woods and waves. 
Shelley, Hymn of Pan. 
2. In eiitom., a genus of coleopterous insects 
of the family Euenemidse. Same as Aiii'ldf /<<. 
l.ntrcillc. 3. In mammal., a genus of macaques, 
named from Macacus silenus, the wanderoo. 
sileryt (sil'e-ri), u. A variant of cilery, celure. 
Silesia (si-le'shia), n. [< Silesia (G. Xclilisien), 
a province of Prussia and of Austria.]- 1. A 
fine brown holland, originally made in Silesia 
and now produced in England: it is glazed for 
window-shades or roller-blinds. Diet, of Xee- 
dletvork. 2. A thin cotton cloth, commonly 
twilled, used for linings for women's dresses 
and men's garments. [U. S.] 
Silesian (si-le'shan), . and . [< Silesia (see 
def.) +-.] I. a. Pertaining to or character- 
istic of Silesia, a territory divided into the prov- 
inces of Austrian and Prussian Silesia, the lat- 
ter much the larger Silesian bole. See Me- 1 . Si- 
lesian wars, three wars waged by Frederick the<Jreat of 
Prussia against Austria, in 1740-42, 1744-5, and 1756 -B3, 
ostensibly for the possession of Silesia. Each war termi- 
nated favorably for Prussia, and the greater part of Silesia 
was permanently acquired. In the third war, generally 
known as the Seven Years' War, Austria, France, Russia, 
Saxony, and Sweden were allied against Prussia, which re- 
ceived subsidies from Great Britain. 
II. n. A native or an inhabitant of Silesia. 
silex (si'leks), . [= F. silex, siliee = Sp. Pg. 
siliee, silica = It. selce, siliee, flint, < L. silex 
(silic-), flint.] Same as silica. 
silfbergite (silf'berg-lt), . [< Silfbenj (see 
def.) + -i/e 2 .] In mineral., a manganesian 
mineral belonging to the amphibole or horn- 
blende group, found at Vester-Silfberg in Swe- 
den. 
silgreen (sil'gren), n. A dialectal variant of 
senyrcen. 
silhouette (sil-9-et'), i. [= D. Dan. silliouct = 
Sw. G. silhuett, < F. silhouette, a profile portrait 
in black, so called after Etienne de Silhouette, 
French minister of finance in 1759, whose rigid 
public economy, intended to avert national 
bankruptcy, caused his name to be applied to 
things cheap, especially to things made osten- 
tatiously cheap in 
derision of him.] 1. 
Originally, a por- 
trait in black or 
some other uniform 
tint, sometimes va- 
ried as to the hair 
or other parts by 
lighter lines or a 
lightening of shade, 
showing the profile 
as cast by a candle 
on a sheet of paper; 
hence, any opaque 
portrait, design, or 
image in profile. Sil- 
houette portraits were 
very common throughout the early years of the nine- 
teenth century, and are often cut out of black paper. 
As he entered the parlor his eye caught upon two sil- 
houettes, . . . black profiles, with the lights done in gold 
about as poor semblances of humanity as could be con- 
ceived. Mrs. Gaskell, Sylvia's Lovers, xxxiv. 
There was a sticking-plaster silhouette of him in the wid- 
ow's bedroom. Thackeray, Bluebeard's Ghost. 
2. Opaque representation or exhibition in pro- 
file ; the figure made by the shadow or a shad- 
owy outline of an object ; shadow. 
The cat's dark silhouette on the wall 
A couchant tiger's seemed to fall. 
WJdttier, Snow-Bound. 
En or In silhouette, shown in outline, or in uniform solid 
color only. 
In the close foreground is this framing of trees, which 
stand out in silhouette against a bright blue sky. 
Harper's Weekly, XXXIII., Supp., p. 60. 
Silhouette (sil-5-et'), v. t. [< silhouette, n.] To 
represent or exhibit in silhouette; make or 
bring out a shaded profile or outline view of: 
used chiefly or only in the past participle. 
A flock of roosting vultures, silhouetted on the sky, lin- 
ger with half-opened, unwilling wing. 
G. W. Cable, Creoles of Louisiana, i. 
He stood silhouetted against the naming Eastern sky 
alone. S. J. Duncan, A Social Departure, xl. 
Silica (sil'i-ka), . [NL. , < L. silex (silic-), flint : 
see silex.] Silicon dioxid (SiO 2 ), or silicic an- 
hydrid, a white or colorless substance, nearly 
insoluble in water and in all acids except hy- 
drofluoric acid. Silica is extremely hard, and fuses 
with difficulty in the oxyhydrogen flame to a colorless 
amorphous glass. In nature, as quartz, it is universally 
distributed, and is the commonest of minerals ; here be- 
long the varieties rock-crystal, amethyst, chalcedony, 
Silhouette of George Washington. 
silicify 
agate, caruelian, onyx, jasper, Hint, hornstune, etc., which 
differ in degree of crystalli/atinn ami in purity, and lienci' 
in color. Silica in the form of quartz makes the sand of the 
sea-shore, and rock-masses as quartzitc and sandstone. 1 1 
also occurs as the rare mineral tridymite, known only in 
volcanic rocks and in a few meteorites, and as the amor- 
phous opal, which is softer and more soluble than quartz 
and contains more or less water. (See quartz, triili/unti', 
opal, also tismanite, c-ristobalite, melanophloyite.) silica 
also forms the material of the spiculcs of many sponges 
and of the frustules of diatoms ; deposits of the latter are 
not uncommon under peat-swamp*, ami in some regions 
vast beds have been accumulated. (See infumrial earth, 
under infusorial.) Silica combines with bases to form 
compounds called silicates, which constitute the rocky 
crust of the globe. It occurs in solution in the waters 
of many mineral springs, and sometimes is deposited in 
enormous quantities about geyser-basins. From the sili- 
cates taken up by plants silica is often deposited on the 
surface or in the interior of their stems. The value of 
the equisetnm, or scouring-rush, is dme to the silica con- 
tained in it, which sometimes amounts to IS per cent, of 
the fresh plant. Sand is extensively used for the manu- 
facture of glass and mortar. The prominent silicates rec- 
ognized among minerals are the mttasUicatex, salts of meta- 
silicic acid (HoSiO :j ), and vrthosilicales, salts of orthosilicic 
acid ( (I ,>ii i t ). Examples are rhodonite, or manganese 
metasilicate(MnSiO.t), ami willemite, or zinc orthosilicate 
(ZnaSitXi). There are also disilicates, polysilicates, etc., 
but they are rarer, and their nature is less clearly under- 
stood. Seey/oft*. mortar'-, and sandl. Also called silex. 
Infusorial silica. Same as infusorial earth (which 
see, under infusorial). Silica bandage, in sury., a ban- 
dage which is moistened with sodium silicate after having 
been applied. 
Silicate (sil'i-kat), . [<.silic-ic + -ate 1 .'\ A salt 
of silicic acid. Silicates formed by the union of silicic 
acid with the bases alumina, lime, magnesia, potassa, soda, 
ete., constitute by far the greater number of the minerals 
which compose the crust of the globe. Glass is a mix- 
ture of artificial silicates of alkalis and alkaline earths or 
metallic oxids(see f/Jowj). Silicate cotton. BMMtfonl. 
Silicated (sil'i-ka-ted), . [< silicate + -crt'- 2 .] 
Coated, mixed, combined, or impregnated with 
silica Silicated soap, a mixture of sodium silicate 
and hard soap. 
silicatization (sil-i-ka-ti-za'shon), n. [< sili- 
cute + -ize + -ution.'] The process of combin- 
ing with silica so as to change to a silicate. 
[Rare.] 
Silicea (si-lis'e-a), ii.pl. [NL., < L. silex (silic-) , 
flint: see silex.] 1. Silicious sponges. See 
Silicisponi/ise. 2. Sponges, excepting Calcarea; 
all non-calcareous sponges. All the existing horny 
or fibrous sponges are supposed to have been derived from 
Silicea which have lost their spicules. or replaced them by 
a fibrous skeletal support. The Silicea, as a subclass of 
Sponyia, are divided by Von Lendenfeld into three ordeis 
Uexactinellida, ChondroKjxmyue, and Cornacu*ponyiie. 
siliceous, See siliciouis. 
silicic (si-lis'ik). a. [< NL. silica + -/c.] Of or 
pertaining to silica : as, silicic ether Silicic 
acid, an acid obtained by decomposing a silicate soluble 
in water with hydrochloric acid, and dialyzing the liquid 
so obtained. The acid is a colloid, ami is obtained in an 
aqueous solution, which if concentrated sets to a jelly. 
Silicic acid has not yet been obtained in the pure form, 
as it undergoes decomposition into water and silica when 
dried. There are several hypothetical silicic acids, from 
which the several classes of silicates are supposed to be 
formed. Such are orthosilicic acid (HaSiO^), metasilicic 
acid (H 2 SiO ; i), and parasilicic acid (HfjSiOs). None of 
these acids has been isolated. Silicic ether, a com- 
pound of silicic acid with an alky], as methyl silicate 
((CH 3 ) 4 Si0 4 ). 
Silicicalcareous (sil"i-si-kal-ka're-us), . [< 
NL. silica + L. caJcarius, calcareous.] Con- 
sisting of silica and calcareous matter. Also 
xiUeocalcareous. 
siliciceratous (sil"i-si-ser'a-tus), a. f< NL. sili- 
ea + Gr. xfpaf (nepa--), horn.] Consisting of or 
containing mixed silicious spicules and horny 
fibers: applied to a group of sponges, the Hali- 
chondriae. 
silicide (sil'i-sid), . K silic-on + -irfel.] A com- 
pound of silicon with a single other element 
which is relatively electropositive, or with an 
organic radical. Also siliciuret. 
siliciferous (sil-i-sif'e-rus), . [= F. silicifere, 
< NL. silica + ferre"= E. tan".] Bearing or 
containing silica; producing silica, or united 
with a portion of silica. 
silicification (si-lis'^-fi-ka'shon), n. [= F. sili- 
cijication; as silicify + -ation (see -fication).'] 
Conversion into silica. 
The most conspicuous of the chemical changes wrought 
in the gravel, as evidenced by the known changes in the 
substances imbedded in it. is silicification. 
J. D. Whitney, Auriferous Gravels of the Sierra Nevada, 
[p. 327. 
silicify (si-H.s'i-fi), r. ; pret. and pp. silic(fii-a', 
ppr. silicifyiiig. [X NL. silica + facere, make, 
do (see -/}/).] I. trans. To convert into silica, 
as organic matter of any kind, especially wood. 
Silicifled wood, jasperized wood, or agatized 
wood, wood which has been changed into the agate or 
jasper varieties of quartz by a replacement of the cellular 
structure of the wood by silicious waters, sometimes con- 
taining oxids of iron and manganese. Agatized and jas- 
perized wood admitting of a fine polish, and of the richest 
red, yellow, and brown colors, occurs in immense quanti- 
