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The next figure is c, in which the pellet has shot out six of those small bodies of equal length, and set at equal angles ; of this kind I saw a considerable number.
The next step in the crystallisation is d, in which those bodies are lengthened, and have shot out a great many more from their sides, at equal angles, but unequal lengths, growing continually shorter and shorter, till they terminate in a point. I'measured some of these, and found them to be about one quarter of an inch in breadth. I saw but very few of them in perfection, for the collateral shoots were so exquisitely fine, as to be liable to be broken in their fall, or confounded together by the least degree of heat.
Of the next kind, E, I saw a very great number, which being examined by the microscope, plainly appeared to be nothing but the former in disorder. The edges of these were, in general, very irregular, but some of them happened to be so indented, as to look like the jagged leaves of plants.
The next kind, F, had 12 points regularly disposed, and probably might consist of two of the former so joined together, as to cut their angles equally.
I saw but very few figures of 12 points, and those mostly imperfect in one respect or other.
Experiments concerning the Degrees of Heat of boiling Liquors.
By M. FAHRENHEIT. [1724.] M. FAHRENHEIT finding, in the history of the Royal Academy of Sciences, that M. Amontons had, by means of a thermometer of his own invention, discovered that water boils with a fixed degree of heat, was very desirous of making such another thermometer, to view with his own eyes this curious phenomenon of nature, and be convinced of the truth of the experiment.
Having made such a thermometer, the event answered his expectation. The issue of the experiments is exhibited in the following table: the first column shows the several liquors used, the second the degree of heat each liquor acquired by boiling.
The degrees of
heat acquired by
boiling. Spirits of wine
176 Rain water
212 Spirit of nitre
242 Lixivium of pot-ash
240 Oil of vitriol
Volatile oils begin to boil with a low degree of heat; but their heat continually increases by boiling; the reason of which may probably be this, viz. that the more volatile particles fly off, while the resinous ones remain behind.
But fixed oils require so great a degree of heat, that the mercury in the thermometer begins to boil at the same time with them; and hence their degree of heat can scarcely be found with certainty in the manner above mentioned.
Experiments and Observations on the Freezing of Water in
Vacuo. By M. FAHRENHEIT. - [1724.] March 2. 1721, he exposed to the cold a glass ball, about an inch in diameter, exhausted of air, and filled with rain-water almost half full; the temperature of the air in the thermometer was marked at 15 degrees. In an hour after, he found the water still fluid in the ball. He then left the ball exposed all night in the open air, and next day, viz. the third of March, at 5 o'clock in the morning, he found the water still fluid, and the thermometer at the same degree ; the cause of which unexpected phenomenon he attributed to the absence of the air. To discover the truth of this conjecture, he broke the extremity of the tube, that the exhausted ball might be again filled with air ; on which the whole mass of water was suddenly mixed with very thin lamellæ of ice. He broke the ball, and putting some of the ice into some water in a glass cup, he observed it floated.
A little time after, he observed all the water mixed with icy lamellæ ; yet the greatest part of the water still continued fluid between the interstices; the thermometer, put into this mixture, stood at 32 degrees. On repeating the experiment with two other balls, and after preparing them in the manner above mentioned, he exposed them for an hour in the open air, the thermometer being then at 20 degrees; an hour after, he found the water still fluid in both the balls, but after the exhausted ball was again filled with air, the water, as in the former experiment, was very soon mixed with icy lamellæ ; and their production was so instantaneous, that it could hardly be observed with the eye. Before he broke one of the balls, he separated the water in the said cup from the icy lamellæ, on which he broke the ball, and threw the ice into water; the ice, it is true, floated on the water, but he in vain expected the production of the lamellæ in the cup.
Concerning the Difference in the Height of a Human Body,
between Morning and Night. By the Rev. Mr. Wasse.
MR. Wasse having measured a great many sedentary people and day-labourers, of all ages and shapes, found the difference in their height between the morning and night to be near an inch. He tried himself when sitting, and found it in like manner ; particularly, August 21. 1723, he sat down, at 11 in the morning, and fixed an iron pin so as to touch it, and that but barely: Afterwards fatiguing himself for half an hour with a garden-roller, the consequence was, that at 12h 30m he could not reach the nail sitting, by about y of an inch. At two the same day he wanted near of an inch. On the 21st, at 6h 30m in the morning, he touched the nail fully; and after the above-mentioned exercise for only a quarter of an hour, at 7h 14m he fell short almost as much as before. On the 27th, having sat up late with some friends, he was faint, and felt himself heavy on the ground, and without any spring, and at nine next morning he did not reach the nail, though he had used no exercise. He rode out, but could not reach it that day. On the 28th he rode about four miles; and whereas at six that morning he reached the nail, he had lost Do of an inch by eight. Sept. 19th he came from Oxford a little tired, and next morning at eight wanted one half of an inch. After studying closely, though he never stirred from the writing-desk, yet in five or six hours he lost near an inch. All the difference between labourers and sedentary people is, that the former are longer in losing their morning height, and sink rather less in the whole than the latter. When the height is lost, it can be regained by rest that day, or by the use of the cold bath.
The alteration in the human stature, it seems, proceeds from the yielding of the cartilages between the vertebræ, to the weight of the body in an erect posture.
The Specific Gravities of several Bodies. By M. Fauren
HEIT, R.S.S. - [1724.] GOLD 19081 Malacca tin
7364 Mercury 13575 English tin
7313 Lead 11350 White marcasite
10481 Regulus of antimony 6622 8834 Brass
8412 Japanese copper 8799 Rock-crystal
7817 Homogeneous Pyrites 2584
fully saturated with
Spirit of nitre
Alcohol of wine
The same, purer 1563
15714 1409 1293! 1000 913 826 825
Of the Currents at the Straits' Mouth. - [1724.] CAPE SPARTEL, and Cape Trafalgar, from the western ocean, are known to make the Straits' mouth; from whence a current, in the middle of the channel, which is about five leagues broad, between the Barbary and Spanish land, runs at least two miles each hour, as far as Ceuta Point; and there the two coasts opening about 18 leagues distant from each other, the current does not run above one mile an hour, and so continues as far as Cape de Gat, which is 70 leagues up the Mediterranean.'
It is very remarkable, that, in the year 1712, Mons. Du L'Aigle, that fortunate and generous commander of the privateer called the Phoenix of Marseilles, giving chase, near Ceuta Point, to a Dutch ship bound for Holland, he came up with her in the middle of the gut, between
Tangier, and there
gave her one broadside, which directly sunk her, all her men being saved by Mons.Du L'Aigle; and a few days after, the sunk ship, with her cargo of brandy and oil, arose on the shore near Tangier, which is at least four leagues to the westward of the place where she sunk, and directly against the strength of the current; which has persuaded many men that there is a re-currency in the deep water, in the middle of the gut, that sets outwards to the grand ocean, which this acci
much demonstrates ; and, possibly, a great part of the water, which runs into the Straits, returns that way, and along the two coasts before mentioned ; otherwise this ship must of course have been driven towards Ceuta, and so upwards.
The water in the gut must be very deep, several of the commanders of our ships of wa having attempted to sound it with the longest lines they could contrive, but could never find bottom.
An Essay on the Natural History of Whales. By the Hon.
PAUL DUDLEY. — [1725.] The right or whalebone whale is a large fish, measuring 60 or 70 feet in length, and very bulky, having no scales, but a soft fine smooth skin; no fins, but only one on each side, from five feet to eight feet long, which they are not observed to use, but only in turning themselves, unless while young, and carried by the dam on the flukes of their tails ; when with those fins they clasp about her extremity, and so hold them
of a whale is about the size of an ox's eye, and situated in the hinder part of the head on each side, and where the whale is broadest; for his head tapers away forward from his eyes, and his body tapers away backward ; his eyes are more than half way his depth, or nearest his under part; just under his eyes are his two fins before mentioned; he carries his tail horizontally, and with that he sculls himself along.
The scrag-whale is near akin to the finback; but instead of a fin on his back, the ridge of the hinder part of his back is scragged with half a dozen knobs; he is nearest the right whale in figure and for quantity of oil ; his bone is white, but will not split.
The finback-whale is distinguishable from the right whale by having a large fin on his back, from 21 to four feet long. He has also two side fins, as the whalebone-whale, but much longer, measuring six or seven feet. This fish is somewhat longer than the other, but not so bulky; much swifter and very furious when struck, and held with great difficulty ; their oil is not near so much as that of the right whale, and the bone of little profit, being short and knobby. The belly of this whale is white.
The bunch or humpback whale is distinguished from the right whale by having a bunch in the place of the fin in the finback. This bunch is as large as a man's head, and a foot high, shaped like a plug pointing backwards. The bone of this whale is worth but little, though somewhat better than the finback’s. His fins are sometimes 18 feet long, and very white; his oil much as that of the finback. Both the finbacks and humpbacks are shaped in reeves lengthwise, from head to tail, on their bellies and their sides, as far as their fins, which are about half way up
their sides. The spermaceti-whale is a fish much of the same dimension with the other, but of a greyish colour ; whereas the others are black; he has a bunch on his back like the hump