R AC 



RAC 



answered by tantus, so much. The com- 

 mon use, however, of the former word 

 renders the latter superfluous. The 

 term quantuplicity, as distinguished from 

 quantity, means the answer to " how 

 many times," as distinguished from 

 "how much;" 



QUA-QUA-VERSAL DIP {qud-qud- 

 versum, on every side). The dip of geo- 

 logical beds to all points of the compass 

 around a centre, as in the case of beds 

 of lava round the crater of a volcano. 



QUART A'TION {quartus, the fourth). 

 An operation by which the quantity of 

 one substance is made equal to a fourth 

 part of the quantity of another: thus, in 

 separating gold from silver, three parts 

 of silver are added to the supposed gold, 

 and they are then fused together, the 

 gold thus becoming at most one-fourth 

 of the mass only. They are then parted 

 by the action of nitric acid. 



QUARTILE. A term formerly em- 

 ployed in Astronomy to denote an aspect 

 of two places when their longitudes differ 

 by 90 degrees, or a fourth part of the 

 circle. 



QUARTINE {quartus, fourth). The 

 name of the fourth membrane or enve- 

 lope of the nucleus in plants, as described 

 by Mirbel. 



QUARTZ. A German provincial term, 

 universally adopted in scientific lan- 

 guage for a simple mineral, composed of 

 pure silex, or earth of flints, extremely 

 abundant in nature, from the common 

 pebble to large mountain veins, and even 

 entire rocks. See Rock Crystal. 



QUARTZITE, or QUARTZ ROCK. 

 An aggregate of grains of quartz, some- 

 times passing into compact quartz. 



QUATE'RN ARY (quaternarius, of the 

 number four). A term applied in che- 



mistry to those compounds which con- 

 tain four elements, as gum, fibrin, &c. 

 The term is also applied to any arrange- 

 ment in which the prevailing number is 

 four, as in the floral envelopes of Cruci- 

 ferous plants, &c. 



QUE'RCITRIN. The yellow colour- 

 ing matter of quercitron bark. As it 

 restores the colour of reddened litmus 

 paper, and combines with and neutralizes 

 bases, it has been considered an acid, 

 and named quercilronic acid. 



QUICKLIME. The protoxide of cal- 

 cium, obtained by exposing carbonate of 

 lime to a strong red heat, so as to expel 

 its carbonic acid. 



QUI'NARY {quinarius, of the number 

 five). A term applied to a system in 

 which the prevailing number is five, as 

 observed in the floral envelopes of most 

 dicotyledonous plants. 



QUINCUNX. In Botany a form of 

 aestivation or vernation, in which there 

 are five leaves, two of which are exterior, 

 two interior, and the fifth covers the in- 

 terior with one margin, while its other 

 margin is covered by the exterior, as in 

 the rose. 



QUINDE'CAGON. A geometrical 

 figure bounded by fifteen sides. 



QUINTILE. A term formerly em- 

 ployed in Astronomy, to denote a dis- 

 tance in longitude of 72 degrees, or a 

 fifth part of the circle. 



QUI'NTINE (quintus, fifth). The fifth 

 membrane or envelope of the nucleus of 

 plants, as described by Mirbel. This is 

 the vesicula amnios of Malpighi, the 

 " additional membrane" of Brown, and 

 the sac of the embryo of Brongniart. 



QUOTIENT or QUOTE {quoties, how 

 often). The result of dividing one num- 

 ber by another. 



R 



RABDO'LOGY {pd/3dov, a rod, \6yot, 

 a description), Rhabdology. A method 

 for performing the arithmetical operations 

 of multiplication and division, by means 

 of an instrument invented by Lord Na- 

 pier, and termed from him Napier's rods 

 or bones. The mode of calculation is 

 tedious, and is now superseded by the 

 use of logarithms. 



RACES OF MAN. Under the terms 

 Caucasian, Mongolian, American, Ethio- 

 pian, and Malay Race, will be found the 



characteristics of these divisions, accord- 

 ing to Blumenbach. The Races are dif- 

 ferent forms of one species, capable 

 of fruitful union, and propagated by 

 generation. 



RA'CEME {racemus, a bunch of 

 grapes). A form of inflorescence, in 

 which all the buds of an elongated 

 branch are developed as flower-buds, 

 and at the same time produce peduncles, 

 as in hyacinth. 



RACE'MIC ACID {racemus, a bunch 



