VERTIGO. 



which external objefts appear to move in various direftions, 

 though ftationary, and there is a difficillty of maintaining 

 the ereft pofture, often accompanied with ficknefs. 



Philofophers have differed in their opinions refpefting the 

 caufe of mertigo, when it is produced under various circum- 

 ftances, independently of internal difeafe ; as from fwinging, 

 turning round rapidly, looking from a high ftation, riding 

 acrofs a broad undulating ftrcam, or over a plain covered 

 with fnow, or looking at the walls of a room painted 

 with equal fniall figures, at a whirling wheel, &c. &c. ; cir- 

 cumftances which might appear upon a cafual view not ex- 

 plicable upon one common principle. Dr. Darwin, how- 

 ever, has very mgenioudy explained the origin of giddinefs 

 from thefe various caufes. He obferves, that in learning 

 to walk, we judge of the diftance of the objefts which we ap- 

 proach by the eye, and by obferving their perpendicularity 

 determine our own ; and that at all times we determine our 

 want of perpendicularity, or inclination to fall, by attending 

 to the apparent motion of the objefts within the fphcre of 

 diftinft vifion. Hence, when we are placed upon the fummit 

 of a high cliff or tower, and look down, we become dizzy, be- 

 caufe the objefts below are out of the fphsre of diftinft vifion, 

 and we are obliged to balance ourfelvcs by the lefs accurate 

 feelings of our mufcles. Hence alfo, on going into a room 

 hung with a paper which is covered all over with fimilar 

 fmall black lozenges, many people become giddy ; for the 

 objefts around being fo fmall, that they do not perceive 

 their minute parts, or fo fimilar, that they do not diflinguifh 

 them from one another, they begin to lofe their balance ; 

 for on inclining to one fide or the other, the next and the 

 next lozenge fucceeds on the eye, which they miftake for 

 the firft, and they are not aware that they have any apparent 

 motion ; but if you fix a fheet of paper, or draw any other 

 figure in the midft of the lozenges, the charm ceafes, and no 

 giddinefs is produced. Giddinefs is occafioned in a fimilar 

 way in riding over an extenfive ])lain of fnow or flieet of 

 water, in which no diftinft objedl prefents itfelf by which 

 we can afcertain our perpendicularity. 



But the circnmftance which occafions vertigo in the other 

 cafes, is the difficulty of diftinguifliing our own real motions 

 from the apparent motions of external objcfts ; and the diffi- 

 culty is ftill greater, when both ourfelves and the circum- 

 jacent objefts are in motion. Our daily practice of walk- 

 ing and riding foon inllrudls us with accuracy to difcern 

 the modes of motion, and to afcribe the apparent motion of 

 the ambient objefts to ourfelves ; but thofe which we have 

 not acquired by repeated habit continue to confound us. 

 Hence whirling round, fwinging, fkating on the ice, failing, 

 riding backwards in a coach, and a thoufand other move- 

 ments, produce giddinefs, which, if long enough continued, 

 bring on ficknefs and vomiting. When firfl an European 

 mounts an elephant fixteen feet high, and wliofe mode of 

 motion he is not accuflomed to, the objcfts fcem to undu- 

 late as he pafTesj and he frequently becomes fick and ver- 

 tiginous. And when we firll go on fhip-board, where 

 the movements of ourfelves, and the movements of the large 

 waves are both new to us, the vertigo is r.lmoft unavoidable, 

 with the terrible ficknefs which attends it. Yet in perfons 

 habituated to thefe motions, no vertigo occurs ; even the 

 mofl continued whirling, as praftifed by the dervifcs in 

 Turkey, as a religiouu ceremony, and by European waltzers, 

 may be learnt to be performed without giddinefs. 



Dr. Darwin mentions fcvcral other circumfLinccs, whieh 

 prove that we require experience in the motions of f(u- 

 rounding objefts, even while we are ourfelvcs at reft, in 

 order to determine our own perpendicularity by them. 

 Whence fome people become dizzy at the fight of a whirl- 



ing wheel, or by gazing on the undulations of a river, if 

 no fteady objefts are at the fame time within the fphere 

 of their diftinft vifion. And he mentions the following 

 curious experiment, illuftrating this faft. When a child 

 firfl can ftand creft upon his legs, if you gain his attention 

 to a white handkerchief fleadily extended like a fail, and 

 afterwards make it undulate, he inflantly lofes his perpen- 

 dicularity, and tumbles on the ground. See Zoonomia, 

 vol. i. fetl. 20. 



Vertigo, however, arifing from any of thefe caufes, is 

 not properly the fubjeft of medical treatment ; and it is 

 only when it occurs independently of external circumftances, 

 that it becomes the object of pathological inquiry. It is 

 not in itfelf, indeed, confidered as a diflinift difeafe, but is 

 always fymptomatic of fome other morbid affection, againft 

 which our remedies muft be directed. Whence Dr. CuUen 

 has excluded it altogether from his clafTification of difeafes. 



Vertigo occurs under three different ftates of the confli- 

 tution,or is a fymplom of three different fpecies of difeafe, 

 which it is neceffary to diftinguifh, in order to apply the ap- 

 propriate remedies. The firfl, and the only variety of ver- 

 tigo that is accompanied with danger, is that which arifes 

 from an over-fiilnefs of the vefTels of the head, and which is 

 fometimes the precurfor of apoplexy or palfy. The vertigo 

 from intoxication is probably chiefly produced in this way, 

 though it may be partly explained upon the principle of de- 

 bilitated mufcular energy, by which the perfon is difabled 

 from directing the eye fleadily upon furrounding objecls, 

 and which even occafions double vifion. 



The vertigo originating from a plethoric ftate of the 

 veffels of the brain will be indicated by the prcfence of cer- 

 tain other fymptoms. If it occurs in a perfon of fanguine 

 temperament, of a full habit of body, florid complexion, 

 in the meridian of life, or pafl that period, and in one ac- 

 cuflomed to free living ; and if it it accompanied by occa- 

 fional head-ache, throbbing of the veffels of the head, noife 

 in the ears, and drowfinefs ; little doubt can remain that it 

 originates from a plethoric condition of the veffels, and that 

 the proper remedies will be, the abflradlion of blood, either 

 from the fyflem at large, or by opening the temporal artery 

 or jugular vein, or by the application of leeches to the tem- 

 ples ; at the fame time adniiniflering moderate purgative me- 

 dicines, and enjoining an abftinencc from fermented liquors, 

 and high-feafoned food, as well as great moderation in re- 

 fpeft to the quantity of the latter. If thefe remedies are 

 not reforted to, and thefe precautions not adopted, the re- 

 fult may be a fudden attack of apoplexy, which may prove 

 immediately fatal, or leave behind it a hemiplegia, or palfy of 

 one fide. 



The fecond variety of vertigo, to which we have alluded, 

 is attended with little hazard, though fometimes very dif- 

 treffing. It occurs in an oppofite condition of the body, a 

 flate of nervous debility, and accompanies many of thofe 

 anomalous atfeftions which arc comprehended under the ap- 

 pellations of b\iJii-ria and hypochondriafis. Tliis vertigo oc- 

 curs in perfons of a different temperament from that above 

 defcribed ; in thin and fparc habits, or in thofe of a certain 

 degree of corpulency, but pale and relaxed conflitution. It 

 is accompanied alfo by other fymptoms charafteriftic of the 

 hyflerial and hypochondriacal difeafes ; .ind cannot eafily be 

 millaken for the plethoric vertigo. The cure, of courfe, 

 will depend upon the general features of the whole com- 

 plaint, of which the vertigo is but a paffing fymptom, and we 

 need not here enlarge upon the fubjeA. See Hvi'OCiION- 

 UHiAsis and Hystkria. 



There is a third variety of vcriigo, which is alfo tranfient 



and void of danger ; whicii is a fymplom of indigeftion ; and 



Pi is 



