sou 



sou 



Fruit an inverfely heart-fliaped capfuh, compreffed, dilated 

 at the margin, of two cells, each containing an oyA feed ; 

 but it often happens that one of thefe feeds is abortive. 



SOULANCOURT, in Geography, a town of France, 

 in the department of the Upper Marne ; 4 miles E. of 

 Bourniont. 



SOULE, a fmall country of France, fo called before 

 the revolution, fitiiated between Beam and Navarre, of 

 ■which Mauleon was the capital, now in the department of 

 the Lower Pyrenees. , 



SOULLIERES, a town of France, in the department 

 of Mont Blanc ; 20 miles E. of St. Jean de Maurienne. 



SOULONA, a town of Thibet ; 20 miles E.S.E. of 

 Couc<iur-Hotun. 



SOULTZ, a town of France, in the department of the 

 Upper Rhine, and chief place of a canton, in the diftridl of 

 Colmar. The place contains 4298, and the canton 9317 

 inhabitants, on a territory of 875 kiUometres, in 9 com- 

 munes. 



SOULZ-SOUS-FORETS, a town of France, in the 

 department of the Lower Rhine, and chief place of a can- 

 ton, in the diftrift of WilTemboiirg ; 2 miles S. of Wiflem- 

 bourg. The place contains 1269, and the canton 13,768 

 inhabitants, on a territory of 145 kiliometres, in 26 com- 

 munes. 



SOUM, in Agriculture, a term denoting the palturage of 

 a full-grown cow. It is moftly apphed to lands in the 

 moory Hate, and fuch as are under the Iheep-walk fyftem. It 

 nearly anfwers, in fome refpetts, to gaite. It is much ufed 

 in the northern parts of Scotland. In the county of Perth, 

 a horfe is accounted two foums ; in fome places four fheep, 

 but in other places five, are eftimated at one foum ; and of 

 young cattle according to their age. The grafs of a foum, 

 in hilly ground, is valued, on an average, from five to feven 

 ftiUlings, according to its quality. By fome, much cenfure 

 has been bellowed on this mode of afcertaining the value of 

 palture or grafs-land in the Highlands : but in mountainous 

 dillridl;, where the ground has never been meafured, and 

 probably never will, where one mountain is exaftly different 

 from another in the quality and quantity of its produce as 

 a pafture, and where there is even a great diverfity in dif- 

 ferent regions of the fame mountain, it is perhaps not eafy 

 to conceive a better method of afcertaining the value of paf- 

 ture than by the number of cattle it can maintain. Who- 

 ever propofts to explode any old cultom, ought, it is fup- 

 pofed, to fubltitute a better in its place. 



Such old culloms are now, however, a great deal more 

 neglefled and difregarded, even in thefe Highland fituations, 

 than was formerly the cafe ; juil in the fame manner as the 

 term gaile has partially grown into difufe in different dif- 

 trifts in the fonthern parts of the kingdom. 



SOUMENZAC, in Geography, a town of Fr.ince, in 

 the department of the Lot and Garonne ; 7 miles N. W. of 

 Laufiin. N. lat. 44° 41'. E. long. 0° 27'. 



SOUND, Sonus, a perception of the foul, communi- 

 cated by means of the ear ; or the effeft of a collifion of 

 bodies, and a tremulous motion confequent upon it, com- 

 municated thence to the circumambient fluid, and propa- 

 gated through it to the organs of hearing. 



Sound is not fimpiy a vibration or undulation of the air, 

 as fome have called it, for there arc many founds in which 

 the air is not concerned, as when a tuning-fork or any other 

 founding body is held by the teeth : nor is found always a vi- 

 bration or alternation of any kind, for every noife is a found, 

 and a noife, as didmguifhed from a continued found, confifls 

 of a fingle impulfe in one direilion only, fometimcs without 



I 



any alternation ; while a continued found is a fucceffion of 

 fuch impulfes, which, in the organ of hearing at leaft, cannot 

 but be alternate. If thefe fucceffive impulfes form a con- 

 nefted feries, following each other too rapidly to be ieparately 

 diflinguifhed, they conftitute a continued found, like that of 

 the voice in fpeaking ; and if they are equal among them- 

 felves in duration, they produce a mufical or equable 

 found, as that of a vibrating chord or Itring, or of the 

 voice in fuiging. Thus, a quill ftriking againfl a piece of 

 wood caufes a noife, but linking againft the teeth of a wheel 

 or comb, a continued found ; andi if the teeth of the wheel 

 are at equal diftances, and the velocity of the motion is 

 conllant, a mufical note. 



To illultrate the caufe of found, we obferve, firfl, that a 

 motion is necefTary in the fonorous body for the produdion 

 of found. Secondly, that this motion exifts, fiirft, in the 

 fmall and infenfible parts of the fonorous bodies ; and is ex- 

 cited in them by their mutual collifion and percuffion againft 

 each other, which produces that tremulous motion fo obferv- 

 able in bodies that have a clear found, as bells, mufical chords 

 or firings, &c. Thirdly, that this motion is communicated 

 to, or produces a like motion, ufually in the air, or fuch 

 parts of any material fubflance as arc fit to receive and pro- 

 pagate it, inafmuch as no motion of bodies, at a diftance, 

 can afteft our fenfes, without the mediation of other bodies, 

 which receive thofe motions from the fonorous body, and 

 communicate them immediately to the organ. Laltly, that 

 this motion muft be communicated to thofe parts that are 

 the proper and immediate inftruments of hearing. See 

 Ear. 



Further, that motion of a fonorous body which is the 

 immediate caufe of found, may be owing to two different 

 caufes : either the percuffion between it and other hard 

 bodies, as in drums, bells, firings, &c. or the beating and 

 dafhing of the fonorous body and the air immediately 

 againfl each other, as in wiiid-inflruments, flutes, trum- 

 pets, &c. 



But, in both cafes, the motion, which is the confequence 

 of the mutual aftion, and the immediate caufe of the fono- 

 rous motion which the air conveys to the ear, is an invifible, 

 tremulous, or undulating motion, in the fmall and infenfi- 

 ble parts of the body. 



To explain this, all fcnfible bodies are fuppofed to confift 

 of a number of fmall and infenfible parts or corpufcles, 

 which are of the fame nature in all bodies, and are perfeftly 

 hard and incompreffible. 



Of thefe are compofed others, fomcwhat greater, but 

 flill infenfible ; and thefe different, according to the different 

 figures and union of their component parts. Thefe, again, 

 conflitute other maflcs, bigger and more different than the 

 former; and of the various combinations of thefe lalf, are 

 thofe grofs bodies compofed that are vifible, tangible, &c. 

 The firfl and fmallell parts, v.'e have obfer»ed, arc abfo- 

 lutely hard ; the others are compreflible, and are united in 

 fuch manner, that, being comprellcd by an external impulfe, 

 they have an elaitic or rcllitutivc power, by which they re- 

 flore themftlves to their natural ftate. 



A fhock, tlien, being made by one body upon another, 

 the fmall particles, by their elaflic principle, move to and 

 again with a very great velocity, in a tremulous, undulating 

 manner, fomewhat like the vifible motions of groffer fprings ; 

 as we cafily obfcrvc in the firings of mufical inllruments. 

 And this is what we may call the fonorous mclion, which is 

 propagated to the ear ; but obferve, that it is tin* infenfible 

 motion of thofe particles next the fmallell, which is lup- 

 pofed to be the immediate caufe of found ; and, of thefe, 



only 



