S YN 



S YN 



if these letters were interchanged, or if 

 each were made to take the place of the 

 other. 



3. In Mathematical language, the term 

 symmetry denotes that quantities which 

 in any manner have a common relation, 

 should have something common in the 

 symbols of notation ; and analogy is, 

 perhaps, a better word than symmetry. — 

 Pen. Cycl. 



SYMPATHETIC INK. A solution of 

 chloride of cobalt. The characters made 

 on paper with this preparation, when dry^ 

 will be invisible; on being held to the 

 fire, the writing will assume a bright 

 blue or green colour ; as the paper cools, 

 the colour will again disappear, in con- 

 sequence of its absorbing moisture from 

 the air; and the phenomenon may be re- 

 produced many times in succession. 



SYMPATHETIC SOUNDS. A term 

 expressive of that natural relation of 

 sounds which occurs in harmonical com- 

 binations, and is particularly illustrated 

 by the sounds of the ^Eolian harp. The 

 term is also applied to sounds produced 

 in one instrument by sounding another 

 close to it; but these are dependent, not 

 on sympathy, but on the vibrations of the 

 intervening air. 



SYMPIESO'METER {avuirie^ia, to 

 compress, fxetpov, a measure). An in- 

 strument for measuring the weight of 

 the atmosphere by the compression of a 

 column of gas. 



SYN- (o-uv). A Greek preposition, sig- 

 nifying with, together. For the sake of 

 euphony, the final n of the preposition is 

 changed into m before the labials b, m, 

 p> ph, ps, &c., as in symmetry, sym- 

 pathy, &c. ; into s, I, r, before these 

 letters, as in syllable, &c. ; and is entirely 

 omitted when followed by two conso- 

 nants, or a double one, as in syzygy. 



SYNCA'RPIUM {avv, together, Kap- 

 iro^, fruit). The botanical designation 

 of an aggregate fruit, in which the ova- 

 ries cohere into a solid mass, with a 

 slender receptacle, as in magnolia, anona, 

 &c. 



SYNCA'RPOUS {avv, together, Kapiros, 

 fruit). A term applied, in Botany, to 

 those fruits in which the carpels cohere 

 together, as in poppy ; when the carpels 

 are distinct from one another, the fruit is 

 termed apocarpous, as in ranunculus. 



SYNCATEGOREMA'TIC {av-^KaTn- 

 76ptijua, that which is said, or can be 

 said, of a person or thing along with 

 other words). In Logic, syncategore- 

 matic words are such as cannot singly 

 326 



express a term, but only a part of a 

 term; these are adverbs, prepositions, 

 &c., and also nouns in any other case 

 besides the nominative. 



SY'NCHRONOUS {avv, together, xp<J- 

 vos, time). That which occurs in equal 

 times, as the strokes of the pulse ; a term 

 synonymous with isochronous. 



SYNDA'CTYLES {avv, together, d«/c- 

 TvKos, a toe). A group of birds which 

 have the external toe nearly as long as 

 the middle one, and united to it as far as 

 the second joint. The group contains 

 the bee-eaters, the king-fishers, the horn- 

 bills, the motmots, and the todies. 



SYNGENE'SIOUS {avv, together, yi- 

 veaci, growth). A term applied to the 

 anthers of plants which grow together 

 by their margins, as in the Compositae. 

 A more precise term is syn-antherous. 



SYNGNA'THIANS {avv, together, 

 7»/ci0of, a jaw). A family of lophobran- 

 chiate fishes, in which the lengthened 

 jaws are united by a surrounding integu- 

 ment, forming a tubular mouth ; they are 

 named from the genus syngnathus, or the 

 pipe-fish. The name is also applied to an 

 order of myriapodous insects, comprising 

 the Scolopendridae and the Geophilidae. 



SYNODICAL PERIOD {avvoba, a 

 conjunction of paths). The simplest in- 

 stance of a synodical period is afforded 

 by the two hands of a watch : the minute 

 hand revolves in one hour, the hour hand 

 in twelve hours ; but the synodic revo- 

 lution of the two hands is the interval 

 which elapses between any time at which 

 they are together, and the next time at 

 which the same thing takes place. "This 

 term is applied in astronomy to the 

 lunar month, or the period of a revolu- 

 tion of the moon round the earth from 

 one synod, or conjunction with the sun, to 

 another; thus, taking the sun's actual 

 revolution at 365| days, and the moon's 

 at 27^ days, we have 



SYNTAX {avv, together, Tdf<r, ar- 

 rangement). That part of grammar, 

 which shows how individual words, the 

 materials of language (the department of 

 etymology), are to be arranged together, 

 so as to form sentences, or aflSrmations 

 containing sense. 



SYNTHESIS {avvBeai^, a putting to- 

 gether). This term denotes composition^ 

 and expresses a process the very reverse 

 of analysis, or resolution. The term 

 Analysis is given to a species of mathe- 

 matical investigation, which commencing 



