#321.  Density.. —­ N. density, solidity; solidness &c. adj.;
impenetrability, impermeability; incompressibility; imporosity[obs3]; cohesion &c. 46; constipation, consistence, spissitude|.
     specific gravity; hydrometer, areometer[obs3].
     condensation; caseation[obs3]; solidation[obs3], solidification;
consolidation; concretion, coagulation; petrification &c. (hardening) 323; crystallization, precipitation; deposit, precipitate; inspissation[obs3]; gelation, thickening &c. v.
     indivisibility, indiscerptibility[obs3], insolubility,
indissolvableness.
     solid body, mass, block, knot, lump; concretion, concrete,
conglomerate; cake, clot, stone, curd, coagulum; bone, gristle, cartilage; casein, crassamentum|; legumin[obs3].
     superdense matter, condensed states of matter; dwarf star, neutron
star. 
     V. be dense &c. adj.; become solid, render solid &c. adj.; solidify,
solidate[obs3]; concrete, set, take a set, consolidate, congeal, coagulate; curd, curdle; lopper; fix, clot, cake, candy, precipitate, deposit, cohere, crystallize; petrify &c. (harden) 323.
     condense, thicken, gel, inspissate[obs3], incrassate[obs3]; compress,
squeeze, ram down, constipate. 
     Adj. dense, solid; solidified &c. v.; caseous; pukka[obs3]; coherent,
cohesive &c. 46; compact, close, serried, thickset; substantial, massive, lumpish[obs3]; impenetrable, impermeable, nonporous, imporous[obs3]; incompressible; constipated; concrete &c. (hard) 323; knotted, knotty; gnarled; crystalline, crystallizable; thick, grumous|, stuffy.
     undissolved, unmelted[obs3], unliquefied[obs3], unthawed[obs3].
     indivisible, indiscerptible[obs3], infrangible[obs3],
indissolvable[obs3], indissoluble, insoluble, infusible.

     #322.  Rarity. —­ N. rarity, tenuity; absence of solidity &c. 321;
subtility[obs3]; subtilty[obs3], subtlety; sponginess, compressibility.
     rarefaction, expansion, dilatation, inflation, subtilization[obs3].
     vaporization, evaporation, diffusion, gassification[obs3].
     ether &c. (gas) 334. 
     V. rarefy, expand, dilate, subtilize[obs3]. 
     Adj. rare, subtile, thin, fine, tenuous, compressible, flimsy, slight;
light &c. 320; cavernous, spongy &c. (hollow) 252.
     rarefied &c. v.; unsubstantial; uncompact[obs3], incompressed[obs3];
rarefiable[obs3].

—­ p. 96 —­

     #323.  Hardness. —­ N. hardness &c. adj.; rigidity; renitence[obs3],
renitency; inflexibility, temper, callosity, durity [obs3].
     induration, petrifaction; lapidification[obs3], lapidescence[obs3];
vitrification, ossification; crystallization.
     stone, pebble, flint, marble, rock, fossil, crag, crystal, quartz,
granite, adamant; bone, cartilage; hardware; heart of oak, block, board, deal board; iron, steel; cast iron, decarbonized iron, wrought iron; nail; brick, concrete; cement.