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posterior edge of the organ, and the other parts immediately belonging to it, such as the medulla spinalis. There are several pieces or sections taken out of the organ, which expose every thing that has any relation to it. At the upper and lower ends of the figure FF, the organ is entire, the skin only being removed. A A, the body of the animal, near the back, covered by the skin; BB, the belly-fin, covered also by the skin; C, part of the skin removed from the organ, and turned back; DD, the muscles which move the fin laterally, and which immediately cover the small organ; É, the middle muscles of the fin, which lie immediately between the two small organs; FF, the outer surface

of the large organ, as it appears when the skin is removed; G, the small organ, as it appears when the lateral muscles are removed; HH, the cut ends of the muscles of the back, which have been removed to expose the deeper-seated parts; II, the cut ends of the large organ, part of which has also been removed, to expose the deeper-seated parts; K, the cut end of the small organ; L, a part of the large organ, the rest having been removed; M, the cut end of the above section; N, a section of the small organ; OO, the middle partition which divides the two large organs; P, a fatty membrane, which divides the large organ from the small; Q, the airbladder; R, the nerves going to the organ; S, the medulla spinalis; T, the singular nerve.

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Observations made on the Mountain Schehallien, for finding its Attraction. By the Rev. NEVIL MASKELYNE, B. D. F.R.S. and Astronomer Royal.-[1775.]

A COMMITTEE was appointed, of which number I was one, to consider of a proper hill on which to try the experiment, and to prepare every thing necessary for carrying the design

into execution.

Perthshire afforded a remarkable hill, nearly in the centre of Scotland, of sufficient height, tolerably detached from other hills, and considerably larger from east to west than from north to south, called by the people of the low country Maiden-pap, but by the neighbouring inhabitants, Schehallien.

The quantity of attraction of the hill, the grand point to be determined, is measured by the deviation of the plumb-line from the perpendicular, occasioned by the attraction of the hill, or by the angle contained between the actual perpendicular and that which would have obtained if the hill had been away. On the south side of the hill, the plumb-line being carried northward at its lower extremity will occasion the apparent zenith, which is in the direction of the plumbline, continued backwards, to be carried southward, and consequently to approach the equator; and, therefore, the latitude of the place will appear too small by the quantity of the attraction, the distance of the equator from the zenith being equal to the latitude of the place. The contrary happens on the north side of the hill; the lower extremity of the plumbline being there carried southward, will occasion the apparent zenith to be carried northward, or from the equator, and the latitude of the place will appear too great by the quantity of the attraction. Thus the less latitude appearing too small by the attraction on the south side, and the greater latitude appearing too great by the attraction on the north side, the difference of the latitudes will appear too great by the sum of the two contrary attractions; if, therefore, there is an attraction of the hill, the difference of latitude by the celestial observations ought to come out greater than what answers to the distance of the two stations measured trigonometrically, according to the length of a degree of latitude in that parallel, and the observed difference of latitude subtracted from the difference of latitude inferred from the terrestrial operations, will give the sum of the two contrary attractions of the hill. To ascertain the distance between the parallels of latitude passing through the two stations on contrary sides of the hill, a base must be measured in some level spot near the hill, and connected with the two stations by a chain of triangles, the direction of whose sides, with respect to the meridian, should be settled by astronomical observations.

Thus there were three principal operations requisite to be formed: 1. To find by celestial observations the apparent difference of latitude between the two stations, chosen on the north and south sides of the hill. 2. To find the distance

between the parallels of latitude. 3. To determine the figure and dimensions of the hill.

By the calculation of two triangles, formed by the two cairns and the two stations of the observatory, the distance between the parallels of latitude passing through the two stations on each side the hill comes out 4364.4 feet, which, according to M. Bouguer's table of the length of a degree in this latitude of 56° 40', at the rate of 101.64 English feet to one second, answers to an arc of the meridian of 42′′.94. The other series of triangles carried across the hill gives the same distance of the parallels only 10 feet less, and, consequently, the arc of the meridian only of a second less. Thus the difference of latitude found by the astronomical observations comes out greater than the difference of latitude answering to the distance of the parallels, the former being 54".6, the latter only 42".94. The difference 11".6 is to be attributed to the sum of the two contrary attractions of the hill.

The attraction of the hill, computed in a rough manner, on the supposition of its density being equal to the mean density of the earth, and the force of attraction being inversely as the square of the distances, comes out about double this. Whence it should follow, that the density of the hill is about half the mean density of the earth.

Account of a Woman in the Shire of Ross living without Food or Drink. By Dr. MACKENZIE.- [1777.]

fit;

and some JANET M'LEOD, unmarried, aged 33 years months, daughter of Donald McLeod, of Kincardine, Rossshire; in the 15th year of her age had a pretty sharp epileptic she had till then been in perfect health, and continued so till about four years after, when she had a second fit, which lasted a day and night; and a few days afterwards, she was seized with a fever of several weeks' continuance, from which she had a very tedious recovery of several months. She took to her bed, complaining much of her heart and head; and afterwards she never rose out of it except when lifted, seldom spoke a word, and had so little craving for food, that at first her parents could only by compulsion get her to take as much as would support a sucking infant afterwards she gradually fell off from taking even that small quantity; so that, at Whitsuntide, 1763, she totally refused food and drink, and her jaw became so fast locked, that it was with the greatest difficulty her father was able with a knife or other methods to open her teeth so as to

admit a little thin gruel or whey, and of which so much generally ran out at the corners of her mouth, that they could not be sensible that any of it had been swallowed.

About this time, they got a bottle of the water from a medicinal spring in Brea-mer, of which they endeavoured to get her to swallow a part, by pouring some out of a spoon between her lips, her jaws all the while fast locked, but it all ran out. With this, however, they rubbed her throat and jaws, and continued the trial to make her swallow, rubbing her throat with the water that ran out of her mouth for three mornings together. On the third morning, during this operation, she cried, "Give me more water;" when all that remained of the bottle was given her, which she swallowed with ease. These were the only words she spoke for almost a year, and she continued to mutter some more for 12 or 14 days, after which she did not speak, and rejected, as formerly, all sorts of nourishment and drink, till July, 1765, when a sister of hers thought, by some signs she made, that she wanted her jaws opened; which her father effected by putting the handle of a horn-spoon between her teeth. She said then, intelligibly, "Give me a drink ;" and drank at one draught about a pint of water. Her father then asked her, "Why she would not make some signs, though she could not speak, when she wanted a drink?" She answered, "Why should she, when she had no desire ?" At this period they kept the jaws asunder with a bit of wood, imagining she got her speech by her jaws being opened, and continued them thus wedged about 20 days, though in the first four or five days she had wholly lost the power of utterance. they removed the wedge, as it made her lips sore. time she was sensible of every thing done or said about her; and when her eye-lids were opened for her, she knew every body; and when the neighbours in their visits lamented her condition, they could observe a tear stand in her eye.

At last

At this

The situation and appearances of the patient were carefully examined the 21st of October, 1767, by Dr. M., who likewise, in October, 1772, being informed that the patient was recovering, visited her, and found her condition to be as follows: About a year preceding this last date, her parents one day returning from their country labours (having left their daughter, as for some years before, fixed to her bed,) were greatly surprised to find her sitting on her hams, on the side of the house opposite to her bed-place, spinning with her mother's distaff. Dr. M. asked, whether she ever ate or drank? whether she had any of the natural evacuations?

whether she ever spoke or attempted to speak? And was answered, that she sometimes crumbled a bit of oat or barley cake in the palm of her hand, as if to feed a chicken; that she put little crumbs of this into the gap of her teeth, rolled them about for some time in her mouth, and then sucked out of the palm of her hand a little water, whey, or milk; and this, once or twice a day, and even that by compulsion: that the egesta were in proportion to the ingesta; that she never attempted to speak; that her jaws were still fast locked, her hamstrings tight as before, and her eyes shut. On opening her eye-lids Dr. M. found the eye-balls turned up under the edge of the os frontis: her countenance was ghastly, her complexion pale, her skin shrivelled and dry, and her whole person rather emaciated; her pulse with the utmost difficulty to be felt. She seemed sensible and tractable in every thing, except in taking food; for, at his request, she went through her different exercises, spinning on the distaff, and crawling about on her hams; by the wall of the house, with the help of her hands; but when desired to eat, she showed the greatest reluctance, and indeed cried before she yielded; and this was no more than, as he had said, to take a few crumbs, enough to feed a bird, and to suck half a spoonful of milk from the palm of her hand. On the whole, her existence was little less wonderful at this time than when he first saw her, when she had not swallowed the smallest particle of food for years together.

Of Persons who could not distinguish Colours. By Mr. J. HUDDART.-[1777.]

THE chief subject of this paper was one Harris, who lived at Mary-port, in Cumberland, near which place, viz. at Allonby, Mr. Huddart lived. Mr. H. had often heard from others that Harris could discern the form and magnitude of all objects very distinctly, but could not distinguish colours. This report having excited Mr. H.'s curiosity he conversed with him frequently on the subject. The account he gave was this: that he had reason to believe other persons saw something in objects which he could not see; that their language seemed to mark qualities with confidence and precision, which he could only guess at with hesitation, and frequently with error. His first suspicion of this arose when he was about four years old. Having by accident found in the street a child's stocking, he carried it to a neighbouring house to enquire for the owner: he observed the people called it a red stocking, though he did not understand why they gave it that denomination, as

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