h ´ ´´
Plato emergit observatus vitro flavo 11 19 5
Solo tubo optico 11 19 31
Vitro cæruleo 11 19 50
Aristarchus emergit 11 21 3
Gassendus incepit emergere observatus vitro flavo 11 25 36
Observatus solo tubo optico 11 25 52
Observatus vitro cæruleo 11 26 11
Gassendus totus extra umbram 11 28 2
Schicardus incipit emergere 11 45 44
Totus extra umbram 11 47 10
Totum Mare Humorum extra umbram 11 46 50
Menelaus extra umbram 11 55 36
Mare Serenitatis extra umbram 11 59 46
Tycho extra umbra observatus vitro flavo 12 00 33
Solo tubo optico 12 00 52
Vitro cæruleo 12 1 14
Incipit emergere Mare Crisium 12 8 31
Totum Mare Crisium extra umbram 12 16 28
Finis eclipsis 12 28 26
Observatio hæc peracta é cœlo claro; umbra autem terræ ita diluta erat,
ut maculæ in ea conditæ satis dignoscerentur.
CV. _Singular Observations upon the_ Manchenille Apple. _By_ John
Andrew Peyssonnel, _M. D. F.R.S. Translated from the_ French.
[Read Nov. 16, 1758.]
THe cruel effects of the tree called Manchenille are known to all the
world: its milk, which the savages make use of to poison their arrows,
makes the wounds inflicted with them mortal. The rain, which washes
the leaves and branches, causes blisters to rise like boiling oil;
even the shade of the tree makes those who repose under it to swell;
and its fruit is esteemed a deadly poison. I was informed, as a very
extraordinary thing, that a breeding woman was so mad as to eat three
of them, which did her very little harm; and this was looked upon as a
miracle, and a proof of the surprising effects of the imagination and
longings of women with child.
But here is a fact, which will scarce be credited by many persons, who
have frequented these Islands: which I declare to be true.
One Vincent Banchi, of Turin in Piedmont, a strong robust man, and an
old soldier, of about forty-five years of age, belonging to the horse,
was a slave with the Turks eleven years, having been taken prisoner at
the siege of Belgrade. He was overseer of my habitation towards the
month of July of the year 1756. He was one day walking upon the sea
side, and seeing a great number of apples upon the ground, was charmed
with their beautiful colours, and sweet smell, resembling that of the
apple called d’apis: he took and eat of them, without knowing what they
were; he found they had a subacid taste; and having eaten a couple of
dozen of them, he fill’d his pockets, and came home, eating the rest as
he came. The Negroes, that saw him eat this cruel fruit, told him it
was mortal; upon which he ceased to eat them, and threw away the rest.
About four in the afternoon, _viz._ an hour after this repast, his
belly swelled considerably, and he felt as it were a consuming fire
in his bowels. He could not keep himself upright; and at night the
swelling of his belly increased, with the burning sensation of his
bowels. His lips were ulcerated with the milk of the fruit, and he was
seized with cold sweats; but my principal Negro made him a decoction of
the leaves of a _Ricinus_[157] in water, and made him drink plentifully
of it, which brought on a vomiting, followed by a violent purging;
both which continued for four hours, during which it was thought he
would die. At length these symptoms grew less; and my Negroes made him
walk, and stir about by degrees; and soon after they were stopped.
Rice-gruel, which they gave him, put an end to all these disorders; and
in four-and-twenty hours he had no more ailments nor pain; the swelling
of his belly diminished in proportion to his evacuations upwards and
downwards, and he has continued his functions without being any more
sensible of the poison. We see by this, that the effects of the poison
of the Manchenille are different from those of the fish at Guadaloupe,
which I mentioned.
Dec. 2. 1756.
CVI. _Abstract of a Letter from Mr._ William Arderon, _F.R.S. to Mr._
Henry Baker, _F.R.S. on the giving Magnetism and Polarity to Brass.
Communicated by Mr._ Baker.
[Read Nov. 16, 1758.]
Dear Sir,
FOR some time past I have been making experiments on the magnetism of
brass, and amongst many pieces that I have tried, find several that
readily attract the needle; but whether they have had this property
originally, or have received it by hammering, filing, clipping, or any
other such-like cause, I cannot yet determine.
I have a very handsome compass-box made of pure brass, as far as I can
judge: the needle being taken out, and placed upon a pin fixed properly
in a board, and clear of all other magnetics, the box will attract this
needle at half an inch distance; and, if suffered to touch, will draw
it full 90 degrees from the north or south points; and I think those
parts of the box marked north and south attract the strongest. The
cover of the box also attracts the needle nearly as much as the box
itself.
As to your supposition, that iron may be mixed with the brass, I do not
know; but I have been informed it cannot be, as brass fluxes with a
much less degree of heat than iron, and iron naturally swims on fluid
brass. Besides, many of the specimens of brass I have tried were new
as they came from the mill, where they were wrought into plates, and
I presume were not mixed[158]; yet these I have given the magnetic
virtue to, when they had it not; and some pieces of brass, which
naturally attract the needle, seem to the eye as fine a bright yellow
as any other, and are as malleable as any I ever met with.
Pieces of brass without any magnetic power, by properly hammering and
giving them the double touch, after Mr. Mitchel’s method, I have made
attract and repel the needle, as a magnet does, having two regular
poles: and I now send you one such piece of brass, which I have thus
made magnetical. You will also receive a couple of needles, which I
made myself after the late Zachary Williams’s method, and a little
stand whereon to place them, the better to shew how this magnetic bar
attracts and repels the needle when properly applied; for it must be
noted, that in making these experiments it is necessary to employ a
very good needle, about 3-½ inches long, well and tenderly set, and not
covered with glass.
You will observe, when you try this bar, that the same poles repel each
other, and the contrary poles attract; which proves this piece of brass
to be indued with true magnetic virtue and polarity. However it must be
noted, that though the same poles repel each other, yet, like natural
magnets, in contact, or nearly so, they attract each other; therefore
when you would shew the repelling power of this brass bar, you must not
bring it nearer the needle than ²⁄₁₀ of an inch.
Magnetic brass does not attract iron, not even the least particle, so
far as I can find: whether this is owing to the weakness of magnetism
in the brass, or to some other cause, I don’t pretend to know.
I have tried to infuse magnetic virtue into several pieces of copper,
lead and pewter; but all my endeavours have not been able to make them
attract the needle at all. Indeed, when I have held a piece of pewter,
that I have tryed to make magnetical, to the needle, the needle would
tremble, but not approach the pewter.
I send you another piece of brass, whose either end attracts either of
the poles; this I have infused the magnetic virtue into, and can at any
time, so as to attract and repel the needle; but, like steel that is
set a low blue, it loseth that polarity in a few hours; which may arise
for its being too short for its weight, or from its different temper of
hardness or softness.
A third piece I also send you, which with all my endeavours I cannot
make attract the needle in the least; and yet I can perceive no
difference between the appearance of this piece and that of those which
do.
Would some ingenious man pursue these experiments, perhaps we might
have needles made of brass to act as strongly as steel ones do, which
would have the advantage of being less liable to rust at sea than steel
ones are.
But my whole design was to shew, that brass is by no means a proper
metal to make compass-boxes of, or to be employed in any instrument
where magnetism is concerned. For as it is demonstrable, beyond
all contradiction, that some brass is found endued with a power of
attracting the magnetic needle; that other pieces are capable of
receiving it either by accident or design, (let it be from its being
mixed with iron, or any other cause whatever) brass must be a very
improper metal for compass-boxes, as it may occasion many sad and fatal
accidents.
Norwich, Octob. 20th, 1758.
It is well known, that brass has been sometimes found to affect and
disturb the magnetic needle; but, to give magnetism and polarity
to brass, has not, that I have yet heard, been before attempted. I
therefore have taken the liberty to lay the above account before this
Royal Society, and have also brought the pieces of brass mentioned
therein, which have been thus made magnetical.
H. Baker.
London, Nov. 15. 1759.