GRAVEL. 



yho, like Mr. Smith, and tlie writer of this article, will be 

 4t the pains to trace the blocks of coarfc (bine alluded to, 

 to their natural bed, and to examine the newly cut, or broken 

 faces of them, and their beds and accompanyinfj ilrata, and 

 of comparing them with the heterogeneous mixtures and un- 

 certain and irregular ftratification of the real gravel-rocks, 

 gf wliich there are great tradls in Nottiugharafiiirc, Derby- 

 (hire, Leicefterfliire, Staffordfliirc, Cliefliire, and others of 

 the midland counties, in fome places of immcrife tliicknefs, 

 will fee abundant caufe tor dilUnguilhing even the coarfjft 

 and moll irregular of our grit-ftone ilrata, from the fupcr- 

 ficial gravel-rocks above-mentioned, and, indeed, from allu- 

 vial, or water-worn mixtures of any kind. And fuch ob- 

 fervers will be llruck witl\ furprize, that fuch a regular and 

 conllant law, as feems to have regulated the formation of 

 grains of fdex, of all the fizes mentioned, fhould not have 

 ^een obferved and reforted to, for explainiiig the formation 

 of coarfe as well as line grit-lloncs, and have guarded again!!, 

 our confounding .them v.ith the water-worn gravels. Ac- 

 cumulations of gravel are to be dillinguillied into native and 

 foreign, according as the pebbles and earth afid extraneous 

 bodies among them, can be referred to known and adja- 

 cent flrata, or conllfts of (lones and earths not elfewhere 

 fomid, or but in very diftant countries. Fur it will be found, 

 that except on the fea fliore, where the waves continually 

 carry away, and again throw up the ftones, wliich fall from, 

 or are waihed out of the marine cliffs, that the gravel of no 

 fpot correfponds with the (Irata on which it is lodged, and 

 if in any fituations in land tliis (liould feem to be the cafe, it 

 will probably be found, that thole Ilrata extend far to the 

 eaft or fouth-eall of the place where their alluvial remains 

 are lodged, and the circumllances appear to be explainable, 

 on the principle of a general moving of native alluvia from 

 the fouth-ealt quarter towards the north-well quarter, as 

 obferved in the Philofophical Magazine, vol. xxxv. p. i^j. 

 It is a remarkable faft, that all the very coarfe, and irregular 

 grit-ftone Ilrata, whicli have been noticed by the writer of 

 this article in England, precede or occur beneath a feries of 

 carboniferous Ilrata, or coal-meafures ; the lovvell being 

 found in the firil and third grit rocks of the great Derby- 

 shire denudation, and the others occur, both above and below 

 the grey lime rock, which forms xbe floor and border of 

 the great South-Wales coal-field (Phil. Tranf i8c6), alio 

 the floor and edges of the foreil of Dcrn coal-bafon, 

 -and the weftern edge of the Somcrfet and Glouceller, or 

 Bath coal-field, the northern edge of the Newcal'.le-uuder- 

 line, or pottery coal-field, &c. And which Liti it leems to 

 be that Mr. Kirwan alludes to, under the name of iemipro- 

 tolite in fome of the cafes mentioned pages 257, 293> 300, 

 307, 312, and 336, of his " Geological Eflays :" it is plain, 

 however, that tliefe coarfe grit-ftones, under our coals, do 

 not indicate the near approach of the fundamental rock of 

 granite, as Mr. Kirwan would have us believe. We cannot 

 clofe this article, without again adverting to the importance 

 of accurately dilcriminating the alluvia found on different 

 parts of every country, and of tracing their connection with 

 the regular a' d continuous mafles of Ilrata on which they rcll, 

 and from v/hence they have been torn. Mucli information 

 on the alluvia and ftrata of the midland couiuies of England 

 will be found in Mr. Farcy's Report on Derbyihirc. 



Gl!AV£L Rod, fignifics a concreted or indurated raafs of 

 fandy Gravm;l, (lee that article,) and is carefully to be dillin- 

 guiflied from the coarfe grit-llone Ilrata, whieli it often 

 »;lofely refemblcG. 



Gravel Fofflls, is a term applied to fuch reliquia, or 

 extraneous foliils, as are found in a rounded or worn Hate, or 

 .lodged asiong gravel, or aliavial mixtures, the ruins of 



abraded and worn Ilrata. See our article Coal, where the- 

 dillinctions between this and other claffcs of extraneous 

 foffils arc explaiued. 



GuAVEL, in Mcilidnt, the popular term for the difordcr 

 occafioned by t(ie formation of fmall calculous, or fand-iike 

 concretions in the kidnies and bl.iddcr. It is the Ncphralria 

 anno/a of Sauvagc ; (fee liis Nofol. Method. Clafs VII. 

 Genus XXV fpcc. 2.) and to be diilingniflied from t'le 

 nephralgia calculi.fa of the fame nofologlll, in which larger 

 calculi, or Jlones, are formed and impatted in tiiu kidnies, 

 ureters, or bladder. 



Tlie fymptoms wliich indicate the prefence of gravel in 

 the kidnies, or in the paflages from tlie kidnies to the 

 bladder, called the ureters, are chiefly a fevere pain in the 

 loins, which is often accompanied by a fcnfe of numbncff, 

 extending down the thigiis of the fide affedlcd, with a re- 

 traftion of the tefticle in tlic male, and with a fickncfs of th-.' 

 ftomach, often amounting to vomiting. During the paffagc 

 of the fmall calc lus through tlie canal of the ureter, the 

 diftenfion and irritation occafioned bv the calculus, efpe- 

 cially if its furface (hould be rugged and uneven, excites 

 thofe fymptoms in a more or lefs fevere degree, or for a 

 longer or (horter duration, according to its {\ut and form ; 

 and they fuddenly ceafe when it has entered the bladder. 

 Pain is again excited in the urinary organs, when the cal- 

 culus either lies over the aperture, or enters the canal of the 

 urethra, and a pain and difiiculty of palling the urine ii 

 excited. Tliefe fymptoms, attending the tranfit of a fmall 

 ilone from the kidney, or its expulfion from the bladder, 

 conllituie wliat is nfually called a fit of the gravel. The 

 more common furiiis of the dileafe, however, confill in the 

 formation of a fori of fandy matter, of a red colour, which im- 

 pedes the free paflageof the urine, and occaltons confiderable 

 pain in the attempt, as well as an aching paiii in the loins, 

 through the fympathy of the kidnies with the bladder. A 

 w, itilh mucoiis matter is fometimes difcharged with the 

 urine, under both ihefe forms of the dili rjcr, pr^ babljr 

 from the irritation excited in the fecreting velftls, that open 

 on the internal furf ice of the bladder : the palfage of the 

 fmall calculi occafionally caufes a laceration of the fmall 

 blood-veilels, and bloody urine is therefore difcharged. 



The little calculi, excited in thofe cafes, are lomctimcs of 

 a bright red colour, and confill, as well as tlie red land which 

 palfe.s with the urine, or is depolited from it, of the uric or 

 lithic acid in a concrete llalc. 



The gravel is a difeafe chiefly of advanced life. It is 

 common in gouty habits, in which it otteii alteniutos with 

 the paroxyfms of gout. It has been obferved, too, that it 

 defcends by hereditary tranfmidion, like that difeafe; and 

 that of the children of gouty parents fome have been attack- 

 ed with the gravel, while oihers have had the gout. It i* 

 a curious fail, alfo, that the concretions, called chalk- 

 llones, which are. depolited in the joints in the gout, con- 

 fill of the fame fub'lancc as thefe gravelly concretions, to's 

 the uric acid. It is to be dilUnguiihcd from the ri'.euir.atic 

 affedlion of the loins, called lumbago, by the fickmis wliich 

 attends the more fevere cafes, the numbnefs of the thigh 

 and retradion of the tellitle, as well as by the mucous or 

 bloody urine, the pain and ditBculty of pafling it, and the 

 appearance of the fandy fediment in it. 



Chcmiih-y has enabled th<» phyfician to adminiller great 

 relief to the fufferings occafioned by gravel. The difcovery, 

 by chemical experiments, tliat the fubftance of thele calcu- 

 lous and f ibulous concretions is an acid, and ikerefore capa- 

 ble of folution in or combinauon with alkaline fubllances, 

 led to the adminillration of the alkalies internally, as reme- 

 dies for the difeafe : and, although it has not been fou;id, 



that. 



