A continuation of the account of the nature causes, symptoms and cure of the distempers that are incident to seafaring people illustrated with some remarkable instances of the sicknesses of the fleet during the last summer, historically related : to which is prefix'd an essay concerning the quantity of blood that is to be evacuated in fevers : being the third part of the work / by William Cockburn ...

Observation V.

John Kock, a Man of three or four and twenty years of Age, complained on May 8th, of a giddiness in his head, a coldness, sudden weakness, and want of appetite; his pulse was low and depress'd yet, in a day or two after, it grew very frequent and strong; he was very hot, had a great drought, and could not sleep.

'Tis plain from this description, that this Man was taken ill of a Fe∣ver, the symptoms of which I have already resolv'd and demonstrated; yet in this case there being an unusual symptom, not yet accounted for, I cannot omit explaining it, how∣ever hard it may be, and maintain my design of plainess, which I have hi∣therto endeavoured. 'Tis known that those who are giddy or vertiginous, have such a sensation, as if every thing they see were turning round, howe∣ver fixt and immoveable it be; and truly this Phaenomenon, tho it may often happen in Fevers, yet either as a symptom of them, or as it is an essen∣tial Disease, has not too often had

the good fortune to be sufficiently explain'd; and if I except two or three, I may venture to say, that a∣mong so many thousand Authors who have written Medicinal Treatises there is not one that has spoken common sense upon this subject; we may hear what a late learned Author, who is thought to speak the fullest and most satisfactorily, says; that the immediate subject of this disease are the animal spi∣rits, the more mediate those parts of the Brain, where imagination and common sense reside, and from whence the nearest way is into the Nervous kind, which are the callous and strious Bodies; for in these parts they love to range and divert themselves as in a spacious field, and pass thro all the pores and thickest passages of the Marrow, with full force like a ray of light: hence it is that, while they glide along in the same Line, from the utmost borders of the Callous Body towards its middle part, they represent pleasant ap∣pearances and imaginations; and whilst they slow, in another line, (perhaps thro other passages, from the middle of the Cal∣lous Body into the gyri of the Brain) they transfer thither the marks of Notions to be laid up for our future remembrance; and, a∣gain,

whilst they pass into the Strious Bodies, and the beginning of the Nerves, they actuate all the moving parts, and carry to them, upon occasions, the instincts of the motions they are to perform▪

But in the Vertigo these equal emanations of the Spirits seem to be intercepted, and variously perverted in different places, because some quantities of the Spirits are obscured, others are determined into other ways, and turned to and frō in so many Vortices one over another. Wherefore confused phantasms, wandring, and &c.

Here is a most poetical flash of a description, but how true, every one must see, that will give himself the trouble to remember the Anatomy of the Brain, and since its make will not at all allow of such a roving and sporting expansion, or so melancholy a circumgyration or turning round, we must seek its cause some where else, and yet this sense is not afford∣ed us from the object it self, which we suppose to be, and often is im∣moveable, and therefore, since this sense is not caused by a turning round of the Animal Spirits, nor by the object that is thought to turn round, it can be no where else than in the

Optick nerve, the Eye it self, or some∣thing that goes to its construction. And first, it is evident that any object will seem to turn round, if the images that come from it fall successively upon different parts of the retina, go∣ing, viz. from the left, while the object is not really moved, and the images that come from it represent always the same distance; I say that object will seem to be turned round from the left to the right; for the images have a contrary posture in the retina, yet this may be done while the motion is only in the Eye, the ob∣ject remaining unmov'd; for whe∣ther the object be moved while the Eye is quiet, or the object be quiet while the Eye is moved, the rays that come from the object, will not fall upon the same part of the bottom of the Eye; and therefore since we judge of the change of place where the object exists, by the change of place upon which the object is de∣scrib'd, 'tis plain that the object which has no motion will seem to move, and may be thought to turn round to the Eyes that are moved▪ Moreover, the object and Eye may be both un∣mov'd;

for if the optick nerve be only moved, the rays will not al∣ways fall upon it in the same situati∣on; and therefore since a direct and oblique falling do not affect the Nerves alike, but excite different sorts of motions; then, the object that is quiet will seem to have chang'd its place, when only the optick nerve is mov'd, the representation of the place where it was being changed. And therefore 'tis evident that any thing that can move the Eye, Optick nerve, or Retina may cause this Gid∣diness, tho the object be not moved. Now there are a thousand things that may produce this effect, but nothing can more readily press upon the Brain than the distended arteries that are next the optick nerve; and since we have seen how the fulness of all the vessels is occasioned by an interruption of perspiration, the cause of our Fe∣vers; there can be no further doubt, but that this fulness may occasion the Retina's being remov'd from its place, together with the optick nerve, so that it cannot receive the rays from the objects at the same part of the bottom of the Eye; and consequently

while the Images change their place in the Retina, the objects are repre∣sented to our mind, as if they were constantly moved. This being pre∣mis'd.

He was let ten ounces of Blood on the 9th, and on the tenth, he had five grains of Tartarum Emeticum, which made him vomit half an hour after he took it. He drunk large draughts of thin water-gruel after every time he vomited till it had done working; which it did very well and made him go twice to stool; next day he began the testaceous powders, and on the fourteenth he had the following purge.

℞. pulv. rad. jalapp. ℈j. resin. jalapp. gr. vii. Crem. Tart. gr. xv. M. ac ca∣piat cum regimine.

It purged him eight times, and he found himself very easie; but since he had no inclination to sleep, I caus'd a doubled linnen wet in vinegar and water to be laid round his head, by which he slept, and awak'd very much refresh'd on the sixteenth.

All this time he drunk water-gruel sharpned with vinegar; and, after his Fever was gone off, the decoctum a∣marum

every morning for four days, and recover'd a pace, 'till, I cannot ••ell by what accident, he died apo∣••lectical, and very suddenly.