platin 
platin (plat 'in), . Sec //< . 
platina i pla-te'nji), . [= I). O. t>w. Dan. /il<i- 
liini = I- . platiiii; < Sp. iilnliiiii = Pg. jiliiliini 
(XI.. platiint). pUtina, so called from its re- 
semblance to silver, < plata, plate, silver: see 
platt.} 1. Same as platinum: the older name. 
2. T\visi-d silver wire. 3. Ail iron plate 
for gin/ing stuff. 
platinate (plat'i-nat), r. I. Same MjrfoMHiw. 
/'/ii/(w. .V./.. ."itli ser., XXVIII. 454. 
plating (pli'tlng), w. [Verbal n. of plate, r.} 
1. The art or operation of covering articles 
with it thin coating or film of metal, especially 
of overlaying articles made of the baser met- 
als with a thin coating of gold, silver, or nickel. 
It it effected in various ways; sometimes the plating 
metal is attached to and rolled out with the other metal 
by pressure ; sometimes the one metal Is precipitated 
from Us solution upon the other, electrochemical decom- 
position being now much employed for this purpose. See 
iltctrotypt. 
2. A thin coating of one metal laid upon an- 
other. 
plating-hammer (pla'ting-ham"er), u. A steam- 
hammer of from 500 to 700 pounds weight, used 
for bending plates and for other operations in 
armor-plating vessels. 
platinic(pla-tiu'ik),a. [(platinum + -ic.} In 
clit HI., of or pertaining to platinum. 
platiniferous (plat-i-nif'e-rus), a. [< NL. pla- 
tinum + L.ferre =E. bear 1 .'] Producing plati- 
num: as, platiniferous sand. 
platiniridium (plat"iu-i-rid'i-um), n. [NL., < 
platin(um) + iridium.] An alloy of platinum 
and indium, occurring in isometric crystals and 
crystalline grains together with native plati- 
num. 
platinization (plat'i-ni-za'shon), n. The pro- 
cess of platinizing, or the condition of being 
platinized. 
platinize (plat'i-uiz), v. t.; pret. and pp. plati- 
nized, ppr. platinizing. [< platin(um) + -tie.] 
To coat with platinum in a fine state of di- 
vision: as, to platinize the negative plate (sil- 
ver) of a Smee's battery, silver Is platinized by 
dipping it or washing It in a solution ot platinum chlo- 
rld, and then heating it in a closed vessel till the salt de- 
composes. The negative plates of iTquhart's potassium- 
bichromate cell which consist each of a copper plate 
having one face and its edges covered with platinum foil 
soldered to the copper, and Its other face covered with 
lead- have their platinum sides platinized by a deposit 
of metallic platinum, obtained by decomposition of plati- 
num chloric! with the aid of a galvanic current, the lead 
being temporarily covered with an acid-proof varnish or 
cement. Also spelled jilatinue. Platinized glass. See 
glass. 
platinochlorid (plat'i-no-klo'rid), n. [< plati- 
num + chlorid.} A double chlorid containing 
platinum: as, potassium platinochlorid. Ethy- 
lene platinochlorid. See ethylaw. 
platinode (plat'i-nod), u. [< NIj. platinum, plat- 
inum, + Or. utvr, way (see cathode).'] The 
negative or non-oxidizable plate of a voltaic 
cefl, which often consists of a sheet of plati- 
num, as in the Grove cell. 
platinoid (plat 'i-noid). H. [< NL,. platinum + 
Or. firfof, form.] One of the metals with which 
platinum is invariably found associated. The 
platinoids are palladium, rhodium, iridium, os- 
mium, and ruthenium. 
platinotype (plat'i-no-tip), H. [< platinum + 
type.} 1. A process of photographic printing 
in which the paper is coated with a solution of 
platinum chlorid and ferric oxalate. When ex- 
posed to the light under a negative and subsequently im- 
mened In a hot solution of potaaslc oxalatv, the metal Is 
reduced in proportion to the action of the light. The pic- 
ture Is then finished by simply washing in slightly acid- 
ulated water. Some patented platinum processes, as that 
of Plzzlghelll, simplify greatly the operations of develop 
in en t. 
2. A print made by any platinotype process. 
Excellent specimens of ptalinoliipfs were shown. 
Set Ainer., N. 8., LIV. 86. 
platinous (plat'i-nus), a. [< NL. platinum + 
-ocx. ] Containing or consisting of platinum. 
platinum (plat'i-num), n. [= F.platine = Sp. 
Pg. It. platiiin, < XL. platinum (with term, -urn 
added, in analogy with other names of met- 
als), < platinii. < Sp. platina, platina (the orig. 
name): see platina.} Chemical symbol. I't: 
atomic weight, 194.9. An important metal, 
introduced into Europe about the middle of the 
eighteenth century from South America, it does 
not occur as an ore, but alloyed with other metals, espe- 
cially with rhodium, osmium, Irldlum, and palladium, all 
of which, together with iron, copper, and gold, are almost 
always present In It In small quantity In what Is called Its 
native state. Platinum Is surpassed In ductility only by 
gold and silver, and In malleability only by those metals 
and copper. It Is easily rolled Into sheets or drawn Into 
wire. Us speclHc gravity Is 81.6, which Is higher than 
that of any other known substance except osmium and 
4540 
Iridium. It is not oxidized In the air nt uiiy ti-mj>erature, 
and Is not attacked by any of the simple acids. It Is In- 
fusible In the strongest heat of a blnst-funiace, but can 
be incited In the flame of theoxyhydrogen blowpipe or by 
means uf the electric current. It is a rare metal, and the 
regions which supply it are few. Most of the platinum 
of commerce comes from the Urals, South America, and 
Borneo. It Is used chiefly for purposes connected with 
chemical manufacture and analysis, where its resistance 
to heat and acids U of special value. It was used for coin- 
age in Russia from !-> to 1845. Platinum chlorid. 
Same as cldoruplatinic acid (which see, under chloropla- 
tiiuc). Platinum luster. See luetern. 
platinum-black (plat'i-num-blak'), . A black 
dull powder consisting of very finely divided 
metallic platinum. It was first obtained by E. Davy, 
and considered to be a nitrite of platinum ; later It was 
recognized by Liebig as metallic, and prepared by him by 
wanning a solution of platinum chlorid in potash with 
alcohol. According to Liebig, platinum-black absorbs 
more than 800 times its volume of oxygen. It can be pre- 
pared In a variety of ways, and Is used In organic chem- 
istry as an oxidizing agent 
platinum-lamp (plat'i-num-lamp), H. In elect., 
an electric lamp in which the incandescent fil- 
ament is of platinum. 
platitude (plat'i-tud), n. [< F. platitude, flat- 
ness (of taste), vapidness, a flat remark, < pint, 
flat: see pin P.] 1. Flatness; dullness; insi- 
pidity of thought ; triteness. 2. A trite, dull, 
or stupid remark; especially, such a remark 
uttered as if it were a novelty; a truism. 
It does not seem so easy for a preacher to trade upon 
his capacity of reserve, yet even In the clerical profession 
many have gained the reputation of profound divines and 
able judges In the spiritual life by a judicious manage- 
ment of solemn platitudes. 
H. If. Oxenham, Short Studies, p. 76. 
platitudinarian (plat-i-tu-di-na'ri-an), a. and 
n. [< platitude (-din-) + -arian.] I. n. Of the 
nature of or characterized by platitude ; given 
to the utterance of platitudes. 
n. . One who is addicted to or indulges in 
platitudes. 
You have a respect for a political platitudinarian as in- 
sensible as an ox to everything he can't turn into political 
capital. George Eliot, Daniel Deronda, xxli. 
platitudinize (plat-i-tu'di-uiz), r. i. ; pret. and 
pp. platitvdinized, ppr. platitudinizing. [< plati- 
tude (-din-) + -i:e, as in attitudinize.] To utter 
platitudes; make dull, stale, or insipid remarks, 
platitudinous (plat-i-tu'di-nus), a. [< plati- 
tude (-din-) + -OHS.} Relating to or character- 
ized by platitude or platitudes; stale; trite; 
flat; dull; insipid. 
platitudinoU8neS8(plat.-i-tu'di-nus-nes),. The 
state or quality of being platitudinous; dull- 
ness; flatness; staleness; insipidity; triteness. 
platlyt (plat'li), adr. [< ME.^taify; < plaft + 
-ly' 2 .} Flatly; plainly; certainly; surely. 
This synne Is ]>ltl</ agayns the Hooly Ooost. 
Chaucer, Parson's Tale. 
If sou banies bowe the brede of an hare, 
I'latly ge be putte to perpetuell pyne. 
York Playt, p. 328. 
platnesst, > [< /<'< 3 + -ess.} Flatness. 
Palsgrave. 
platode (plat'od), . Same as platoid: corre- 
lated with centode, trematode, and nematode. 
platoid (plat'oid), n. [Irreg.< Gr.jrAari'f, broad, 
flat, + cifof, form.] Broad or flat, as a worm. 
platometer (pla-tom'e-ter), n. [Irreg. < Gr. 
ir/arif , flat, H- fitr/Hiv, measure. ] Same as pla- 
nimcter. 
platometry (pla-tom'et-ri), n. [< Gr. ir/.drof, 
breadth, + -utrpia, < fterpov, measure.] The art 
of measuring the breadth of rivers. Dee, 1570. 
Platonia (pla-to'ni-&), . [NL. (Martins, 1829), 
< Plato, < Gr. ID-druv, the Greek philosopher: 
see Platonic 1 .} A small genus of tropical Amer- 
ican trees, belonging to the natural order Gutti- 
fi-ree and the tribe Moronoliex. It Is chiefly dis- 
tinguished from the other genera of the tribe by the an- 
thers being borne al>ove the middle of the numerous fila- 
ments into which the phalanges of stamens are divided. 
The genus embraces only two (perhaps only one) species, 
large trees with coriaceous, delicately penninerved leaves, 
solitary and showy pink flowers, and five-celled fleshy ed- 
ible berries. The fruit of /'. tn*wni*, called pacoury-uva 
In Brazil, is said to be highly delicious, Its seeds almond- 
s' iivored. 
Platonic 1 (pla-ton'ik), a. and . [Formerly 
also Platoiiiet', PlaUmil'e; = F. Platonique = 
Sj,. PlaUnieo = Pg. It. Ptotonieo, < L. Platnni- 
CIIK, < Gr. n/artiKocof, of or pertaining to Plato, 
< IP.aruv, L. Plato, a Greek philosopher, son of 
Ariston, orig. named Aristocles, and surnamed 
W.druv with ref. to hit* broad shoulders, < v).a- 
n'f, broad : see plat*.} I. a. Pertaining to Plato 
(about 427-347 B. c.), or to his doctrines. 
Reference to the school of Plato and to his followers is 
nine usually expressed by the adjective /'fafonufiV. Plato 
wrote In dialogues, which are equally admirable from a 
literary and from a philosophical point of view. He held 
that the object of philosophy Is beauty: that without a 
Platonism 
deep sense of Ignorance no man can philosophize ; Unit 
judgments of common sense are open to doubt ; that the 
senses may err, and at best can afford only likelihood 
(tinuria); that experience (Sofa), built out of perceptions, 
though safer, does not know the reasons of phenomena ; 
and that man is the measure of things, not in his experi- 
ence of particular facts, as Protagor&s would have it, but 
in his knowledge of reasons, which alone is ennobling. 
Philosophy according to I'lato has three branches dia- 
lectic, physics, and ethics. Dialectic, the art of discus- 
sion, proceeds by definition and division. Division should 
be by dichotomy. He holds strongly to the truth of cog- 
nition ; the process of mind and the process of nature are 
one. Neither the Kleutic doctrine that all Is One, and 
the Many mere illusion, nor the Ueraclltan doetrine that 
there is only a fluid manifold without unity, is the truth ; 
there is a mixed being (M<T>I oixria) : being has an eter- 
nal and an evanescent element, and only a compound of 
these can be an object of science. The One in the Many 
is the Idea, the active force prescribing regularity (as we 
should say, the law of nature), which in supercelestial 
place subsists while individual cases arise and perish. 
The ideas make up an organism, or living system (<,V')- 
They are themselves regulated by an idea of a teleologlcal 
character, the Good, or ultimate purpose of all things, 
Identical with Reason, the true Being (oirut <">i ), the One. 
King of heaven and earth, which, Immutable, draws all 
things toward itself. This Reason is God, who Is related 
to the Ideas as a poet to the Ideals he has created and in- 
tends to embody. That other element which in the ac- 
tual condition of things in this world has not yet been 
eliminated so as to leave pure Reason Is extended quan- 
tity (jmcpov K(U MY A ) f body (<7uMa), nearly Aristotle's 
matter (uA>j). This is the secondary principle (avi-airtof) 
of the universe. God, the father, implants the seed of the 
Good In space, the mother, and without his furl her Inter- 
vention the Cosmos, the only begotten son of God, made 
in his likeness, grows up. This Is a second blessed god. 
Instinct with Reason. Plato was a political philosopher. 
He abhorred alike the sway of oligarchy and of democ- 
racy, and still more the outcome of the latter, the one-man 
power tyranny. He believed in aristocracy supported by 
an iron socialism. The relations of the sexes should be 
so regulated as to stop all increase in the population, 
which should be limited to 5,040 households. Private 
property and family relations should be abolished. Three 
classes should be recognized workmen, soldiers, and law- 
yers. The education of a lawyer should begin with mu- 
sic, gymnastic, and mathematics. In his thirtieth year 
(up to which age he should be seen and not heard) he Is 
to begin the study of dialectic. His education should be 
completed at the age of fifty, when he Is to take his share 
in the government. The above is an outline of the general 
views of Plato ; many of his special opinions are celebrated. 
He strongly maintains the immortality and previous ex- 
istence of the soul. The tie which holds body and soul 
together is music. Virtue is not natural, nor can it be 
commanded by the will, but it is the n ml i of discipline. 
The cardinal virtues are wisdom (<ro4<i), courage (a6pmX 
prudence (aux&poair)]). and justice (MMIOOTWIJ. The un- 
just alone prosper; the perfect man would suffer on the 
cross. Reason resides In the head, desire in the abdo- 
men, prophesy in the liver. Time Is an image of eternity : 
it is produced by circular motions. Nature abhors a 
vacuum. Like attracts like. The constellations and the 
earth are living divinities. Plato was a mathematician, 
and is said to have invented the ancient method of analy- 
sis. His thoughts constantly show the influence of mathe- 
matical studies, and the desire to import mathematically 
distinct conceptions into philosophy. Aristotle, who was 
Plato's scholar, declared that the Platonic Ideas were num- 
bers. Plato no doubt attributed active virtues to the 
ideas of One, Two, Three, and Four. 
Now the first Christians many of them were Platonick 
Philosophers. Selden, Table-Talk, p. 63. 
We are apt to ridicule the sublime Platonic notions they 
had, or personated, In love and friendship. 
Swtft, Conversation. 
Platonic bodies, the five regular geometrical solids which 
Inwrap the center only once namely, the tetrahedron, 
thehexahedronorcube, theoctahedron, thedodecahedron, 
and the Icosahedron. Platonic idea. See idea. Pla- 
tonic love, a pure spiritual affection subsisting between 
the sexes, unmixed with sensual desire, and regarding the 
mind only and its excellences. 
The Court affords little News at present, but that there 
Is a Love called Platonic Love. Hoirett, Letters, I. vi. i:,. 
Platonic year. See year. 
II. . 1. A follower of Plato; a Platonist. 
Other things which he with great palnes hath gathered 
out of the Platoniket, stamped with Zoroasters nanie, are 
many of them dluine. Purchas, lllgrlmage, p. 367. 
2. One who loves with a Platonic affection. 
A talking dull Platonic I shall turn ; 
Learn to be civil when I cease to burn. 
Prior, Ode, St. 5. 
Platonic'-' (pla-ton'ik), n. [< Gr. U/.&TUV, Plato 
(see def.).] Pertaining to the Greek comic 
poet Plato (about 427-388 B. c.) Platonic me- 
ter, in fine. proa., a meter or period consisting of an iambic 
penthemimeres between two dactylic penthemlmeres. 
Platonical (pla-ton'i-kal), a. [< Pln/miii-i + 
-al.} Same as Platonic 1 . Dp. A1ti i rl>nry. Ser- 
mons, I. xi., Pref. 
Platonically (pla-ton'i-kal-i), adr. In n I'la- 
tonir inanniT. Mr //. U'littoii. 
Platonise, Platoniser, . Sec Platni;i-. /'/,/. 
ftmiMr. 
Platonism (pla'to-nizm), n. [< Gr. Il/drur. 
Pinto, + -i;.] 1. The doctrines, opinions, or 
philosophy of Plato, or of the Academic school. 
2. A Platonic saying or proposition. 
The itrikinii Platoninm of Coleridge, 
R. Chtiatr, Addresses, p. lli.".. 
