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The Philosophical transactions of the Royal society of London, from their commencement in 1665, in the year 1800 (Volume 8) online

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to the focus k, where they will form an inverted image ; and being reflected by
the small speculum cd, they will pass through the perforation of the great
speculum, and falling on the plano-convex glass ef, converge again, and form
an erect image at I ; which being brought very near to the eye, and so con-
siderably magnified, will be distinctly seen through the eye-glass gh.

yin Account of the Standard Measures preserved in the Capitol at Rome. By
Martin Folhes, Esq. V. P. R. S. N° 442, p. 262.

In the wall of the capitol is a fair stone of white marble, of the length of 8
feet 5 inches English, and of the breadth of 1 foot 9-f inches ; on which are
inscribed the standards of several measures with these respective inscriptions :
Piede Ro : Pal. iiii. One. xii. Deti xvi.

Piede Greco.
Canna di Architet. Palmi x.
Staiolo Pal. v. Quar. iii.
Canna di Merca. Palmi otto d'altra misura.
Braccio di Merc. Pal. iii. d'altra misura

Braccio di Tessito di Tela.
Curante Lu. Poeto.
The lines, that represent these measures, are cut in the marble, pretty deep;
but as they have, consequently, a considerable thickness, it is somewhat difii-


cult to be very exact in taking off their dimensions. Mr. Folkes however did
it as nearly as he could, by setting the point of his compasses in the middle of
the cross lines, that are drawn to determine the beginnings and ends of the
measures. The palm of the architects is easier to give than the others, be-
cause the whole canna is inscribed on the stone : this he therefore took off,
and then divided it into 10 equal parts. Afterwards his chief attention was
given to the Roman foot, as of greater consequence than the other measures.
They all however follow, a^Hhey occurred to him, in such parts as the London
foot contains 1000.

The Roman foot 966 +. This is divided on the stone, first into 4 palms, and
then on the upper part into 12 unciae, and on the lower into 16 deti, accord-
ing to the inscription.
The Greek foot 1006 -|-. This is also divided like the Roman.
The canna of the architects 7325. It is divided into 10 palms, each of which,

is therefore 732-i^ of the English foot.
The staiolo, being 5 palms and \, is 4212 —.
The canna de mercanti, divided into 8 palms of another measure, 6 feet 6

inches 4-1-.
The braccio de mercanti, divided into 4 palms of another measure, 2 feet 9

inches -14.
The braccio di tessitor di tela, divided into 3 parts, 2 feet 1 inch^x-

The palm of the architects is assigned by Mr. Greaves 732 of the English
foot ; and the same is given by M. Picart to the Paris foot, as 4944- to 720 ; '
which reduced, becomes 732 -|- of the English foot, as before, and as it came
out from this trial.

The Roman foot is given by Picart, from this very stone, 653 ,V of such
parts, as the Paris foot contains 720 ; that is, by reduction, 967 + of the
English ; and the same by Fabretti, who also measured it on this stone, is
assigned to the palm of the architects, as 2040 to 1545 ; which reduced on the
former measure of the palm, is 966-^ of the English foot. These measures
come out as near as the nature of the standard can possibly allow ; and as it was
somewhat fresher in Picart's time, than it is now, Mr. F. would make no dif-
ference in the proportion he has assigned ; but supposes the Roman foot on
this marble was intended to be such a one, as should contain 967 parts of the
English very nearly,

Mr. Greaves had long before assigned the measure of the Roman foot from
Cossutius's monument, to be 967 of the English, and had preferred that mea-
sure to the others he had taken from the tomb of Statilius, and the Congius of

L 2


Vespasian. And there seems no doubt but Cossutius's foot was the foot in-
tended to be inscribed on this marble ; though that monument is itself now lost.
For the Greek foot, there seems to be no further mystery, than that it was
intended to be made to the Roman, in the proportion collected from Pliny,
which is, that 6'25 Roman feet made 600 Greek ; by which account the Greek
foot should contain 1007 of such parts as the Roman contains 967 ; and the
actual quantity Mr. F. took off, was 1006.

Some Observations, made at fVittemberg in 1734. By John Fred. PFeidler,

F. R. S. N" 442, p. 266.

These observations, like those of former years, by M. Weidler, are chiefly
on the aurora borealis, the weather, &c. ; and no longer useful.

Observations made of the Latitude, Variation of the Magnetic Needle, and
Weather, by Capt. Christopher Middleton, in a Voyage from London to
Hudson's Bay, Anno 1735. N° 442, p. 270.

These observations are nearly alike with those before printed. Vol. vii, p. 465
and 617, of these Abridgments.

An Experiment, to show that some Damps in Mines may be occasioned only by
the burning of Candles under Ground, without the Addition of any noxious
Vapour, even when the Bottom of the Pit has Communication with the out-
ward Air, unless the outward Air be forcibly driven in at the said Com-
munication or Pipe. By the Rev. J. T. Desaguliers, LLD., F. R. S.
N°442, p. 281.

Exper. 1 . — In a cylindric glass-receiver, open at both ends, whose lower end
is plunged in water, and upper end covered with a plate, having a hole of near
an inch bore, a candle of 6 in the pound will not burn quite the time of one
minute, before it goes out.

Exper. 2. — A candle will burn almost as long when the receiver is quite

Exper. 3. — The receiver having the hole of the plate open, and a pipe at
bottom communicating with the external air, will burn but a little longer than
in the first experiment ; and by blowing in at the pipe with your mouth, it will
go out rather sooner.

Exper. 4. — Blow in at the pipe with bellows, and the candle will burn as
long as you will.


A Chemical Experiment, serving to illustrate the Phenomenon of the Inflammable
Air shown by Sir James Lowther, Bart, as described in Phil. Trans. N" 429.
Bi/ Mr. John Maud. N° 442, p. 282.

Sir James Lowther made an experiment on some air which he collected
out of a coal-mine, and brought in bladders, close tied, by sea to town; the
effects of which was, that the air being pressed out of the bladder through
the small orifice of a tobacco-pipe, would catch fire from a lighted candle, and
burn like an inflammable spirit, till it was all consumed.

On considering that the cause was only a great quantity of sulphureous
vapours fluctuating in that air, Mr. M. was naturally induced to make an essay,
by an artificial mixture, to produce the like eflfect. It is very well known (he
observes) to every one versed in chemical affairs, that most metals emit great
quantities of sulphureous vapours, during the effervescence they undergo, in
their solutions in their respective menstrua, or solvents. Of these fumes, iron
emits a great quantity while it is dissolving in oil of vitriol, which are very in- .
flammable, and not easily to be condensed. These fumes Mr. Maud collected
into a bladder with the desired success, and having produced before the Royal
Society two bladders of this fictitious air, at the same time that Sir James
Lowther made trial of his, they both exhibited the same phasnomena. A par
ticular account of the preparation made use of is as follows.

Mr. Maud took jij of oil of vitriol, and mixed it with jviij of common
water, which he put into a glass with a flat bottom, about 10 inches wide, and
3 deep, with a long neck ; to this he added jij of iron filings : there instantly
arose a great heat, with a violent ebullition, and the iron was wrought upon
very fast, with a copious exhalation of fumes. To the end of the neck of the
glass he luted a bladder, void of air, the neck of the bladder being fastened to
a tobacco-pipe ; the fumes arising from the dissolving metal soon puffed up the
bladder to its full extent, when that being taken away, the neck of it being first
tied close with a string, he applied another in the same manner : thus may be
got as many bladders full as you please, while the effervescence lasts. Two of
these bladders were tried before the Society, and exhibited a flame like those of
Sir James Lowther's, very like in the smell, though somewhat different in the
colour of the flame. After Mr. M. had pressed part of the air out of the blad-
der, by drawing back the hand, the flame was sucked into the bladder, which
set on fire what inflammable air remained all at once, and went off like a gun,
with a great explosion.

It is worthy of notice in this experiment, that all the air which filled the


bladders was, as it were, generated de novo out of the mixture, or else re-
covered from being locked up in the body of the metal in an unelastic state.

This experiment will easily explain a very probable cause of earthquakes,
volcanoes, and all fiery eruptions out of the earth ; for nothing more is re-
quisite than iron, a vitriolic acid, and water. Now iron is generally found ac-
companied with sulphur ; and common sulphur may be analized into an inflam-
mable oil, and an acid liquor like oil of vitriol. This acid therefore in the
bowels of the earth, by being diluted with a little water, surrounds the iron
and works upon it in the same manner as described above ; an effervescence and
intesthie heat arise ; the air which comes from the mixture is rarefied, and be-
comes very elastic ; its impetus, as it is the more compressed by the incumbent
weight of earth, is increased even to an unlimited degree ; and at length, like
gunpowder, will remove all obstacles, and exhibit to the spectators above ground
the terrible phaenomena of earthquakes and eruptions. Sometimes these in-
flammable fumes, if very much heated, as soon as they come to the open air,
will catch fire, and so produce those fiery eruptions, of which there are so
many instances in the world.

^n Account of the Storm, Jan. 8, 1734-5. By Mr. Henry Forth.

N° 442, p. 285.

At Darlington, 14 miles south from Durham, lat. 54° 46', the evening be-
fore the 8th of Jan. 1734-5, Mr. Forth's barometer stood at 29 inches, but
had been gradually falling for two days. The wind was then s. w. and of the
second degree of strength ; which increased towards midnight a degree more.
Most of the day there was snow or sleet.

The 8th in the morning he found his glass fallen to 28.38 inches, and at 4
o'clock p. M. down to 28.05 inches, but by 10 in the evening risen again to
28.45 inches. All this while the wind was in the north east, with only a
moderate gale, though attended all day with snow, which at night was 2 inches
and a quarter deep ; and about 8 it began to freeze. As the wind in the
southern parts was all that time in the opposite quarter, Mr. Forth would have
expected an accumulation of the air, and as a consequence the rising of the
barometer, at the time of its falling the lowest. Had the storm been the night
before, when in the northern parts the wind was in the same direction, and had
afterwards fallen, he would then have imputed the fall to the quick return of
the current of air to restore the equilibrium.



Of the Bones of yinimals changed to a Red Colour bi/ Aliment only. By John
Belchier, Surgeon, F. R. S. N" 442, p. 287.

That the circulation of the blood is carried on through the bones, is evident
(Mr. B. observes) from many phaenomena in surgery ; but that it is universally
and intimately distributed through the most solid and compact substance of the
bones, though hitherto by some made a matter of doubt, will appear undeniably
from the instances here produced ; which are the bones of several hogs, of a
different breed, changed to a deep red colour, merely by aliment. And what
makes this still more surprising is, that neither the fleshy nor cartilaginous
parts suffer the least alteration in colour or in taste.

The diet of these hogs was bran, after it had been boiled in a copper with
printed callicoes, in order to clean them from a dirty red colour occasioned by
an infusion of madder root, which is used to fix the colours printed on the
cloth. Some of these colours are made with preparations from iron, others
with a mixture of alum and sugar of lead. The parts printed with the pre-
paration of iron, produce black and purple ; those printed with the mixture of
alum, red of different degrees, according to the strength of the mixture. The
bran having .absorbed the red colour discharged from the cloth, was mixed with
the common food of the hogs, and produced this effect on their bones.

On examining these bones, Mr. B. observes in general the solid parts to be
most tinctured, and the teeth particularly, except the enamelled part, which
is of a different substance ; and on sawing them through, he found the internal
parts equally tinged, except at the ends of the bones, where the substance is
more spongy. And in order to discharge the colour, he macerated them in
water for many weeks together; boiled them often, and steeped them in spirits,
but all proved ineffectual ; nor was the least tincture given to any of the liquids,
on which he made experiments.

^n Observation of a white Liquor resembling Milk, which appeared instead of
Serum separated from the Blood after it had stood some time. By Alexander
Stuart, M. D., F. R. S. N" 442, p. 289.

One John Wicks, a carver, in Bromley-street, about 40 years of age, had
been ill about 3 weeks by a loss of appetite and indigestion, and at last a pain
and distention of his stomach, with a low degree of an inflammatory fever; his
tongue dry, rough, and of a rusty brown colour in the middle, with a white
soft list on each side ; his urine very high coloured, with a large quantity of a
slimy pink-coloured sediment ; his stools very yellow and loose.


Eight ounces of blood being taken away ; instead of serum, nothing appeared
above the coagulum but this white liquor, resembling milk, which Dr. S. poured
off to the quantity of about 4 oz. at first there was no smell perceptible; but in
6 days it began to have the smell of rotten eggs : it stood in a room where there
was a fire, for some hours of the day, for 3 weeks more, in which time it did
not alter its consistence nor smell.

The patient had eaten very little for a week before Dr. S. first saw him ; and
only a little of a calfs foot stewed, the night before, for supper, and no break-
fast that day. He was addicted to drinking strong pale malt liquor every day
he was in health.

If this be chyle, it is a substance very different from milk, which is apt to
turn sour and thick by keeping, and never contracts the putrid smell of rotten
eggs, as this did. Whether it be not chyle turned putrid, and near to puru-
lency, by a long circulation in the blood-vessels, but not converted into blood,
through some defect in the sanguification, is a question which probably cannot
be decided, without more observations and experience.*

The coagulum of the blood was covered with a sizy pellicle, about the thick-
ness of a shilling. The red part was of a grumous, tender, incoherent con-

Though he was much better in a week's time, the Doctor ordered 5 oz. of
blood to be taken away, to see what change had been made ; and he found the
coagulum covered with a sizy pellicle to the thickness of half a crown, the red
part of a due consistence, the serum clear, without any chyle.

The urine became clear, and he recovered in about 2 weeks after the Doctor
had first seen him.

^n Account of what was observed on opening the Corpse of a Person who had
taken several Ounces of crude Mercury internally ; and of a Plum-Stone lodged
in the Coats of the Rectum. By Dr. Madden, of Dublin. N° 442, p. 29 1,

Some time ago Dr. M. was present, with Dr. Robinson, and Mr. Nichols,
surgeon-general at Dublin, at the opening the body of a gentleman in that
town, who for several years had found great difficulty in going to stool. This
disorder increased on him towards the latter end of his life, and he was seized
with a violent distemper, of which Dr. M. says he could give no description,
having never attended him. In order to procure a passage downward, which

* It was probably the albuminous fluid existing in an excessive proportion in the blood ; and if so,
it would have yielded a coagulum had it been exposed to a sufficient degree of heat j but to this
simple test it was not lubjected.


Dr. M. supposed was a principal complaint, he took, by the advice of a physi-
cian, several ounces of crude mercury, at different ti(nes, without any relief,
and at length he died.

On opening the abdomen, which was very much distended, there burst forth
a great quantity of wind, though the guts and stomach were not wounded.
The stomach was empty ; and the inner coat was very much inflamed from one
end to the other. In several places of the small guts, there were scattered
grains of crude mercury, and along with them generally a black gritty powder,
very like ^Ethiops mineral, which was doubtless the mercury changed into that

The colon was distended, at its origin, to twice the thickness of an ordinary
man's arm about the shoulder. This extraordinary thickness extended to about
the length of 10 or J 2 inches ; from hence it gradually decreased, and where it
was attached to the stomach, it was not above a third part of that size. It was
much inflamed at its origin, and contained at least 6 quarts of liquid excrement,
in which was observed crude mercury, as also some of the black powder above-

The colon, where it parted from the stomach, and diverged towards the left
kidney, adhered about the space of 3 inches to the omentum ; and on sepa-
rating the adhesion, there was found an abscess and inflammation, which had
communicated to those parts of the ileon, contiguous to the colon. The colon
had in this place a perforation, about f of an inch in diameter, and 4 smaller
perforations, about the size of a goose quill, through which some excrement
had passed into the abdomen.

The coats of the colon, as it approached the intestinum rectum, became
scirrhous, about the space of 6 inches, and the capacity was gradually smaller.
The valves of the colon about this place were of a reddish colour, and were
more scirrhous than the other parts of the intestine. The coats of the colon,
where it was continued to the rectum, were at least half an inch thick, and its
capacity was not above the fourth part of the natural size.

On cutting the gut horizontally hereabouts, there was perceived a body
which stopped the passage, and seemed to the touch almost of a cartilaginous
consistence. Having opened the gut lengthwise, it was found that it was no
more than 2 of the valvulse conniventes coli become scirrhous, and which pro-
truded downward into the rectum.

There was also found a small plum-stone in this place, which was quite
buried in the tunica villosa, and had made itself a bed between the coats of the
rectum. It had formed a small abscess, which discharged into the cavity of the
pelvis ; but it had no communication with the cavity of the rectum. ..



A Solar Eclipse observed at Rome, May 3, 1734, N.S. By the Abbh de
Revilus, F. R. S. and Andr. Celcius, F. R. S. N° 442, p. 294.

True time.
At lO*^ 22"" 35% A. M. The eclipse had begun a Utile.
] ] 5 O , The greatest obscuration 2 digits.
11 51 O, The end of the eclipse.

The Description and Manner of using an Instrument for measuring the Degrees
of the Expansion of Melals by Heal. By Mr. John Ellicott. N°443, p. 297.

AA, (fig. 6, pi. 4) represents a flat plate of brass, which, for more strength,
is screwed down to a thick piece of mahogany : on this plate are screwed three
pieces of brass, two of which, marked bb, serve as supports for the flat iron
bar c ; and which, on account of its use, is called the standard bar. The upper
part of the third piece of brass is a circle, about 3 inches diameter, divided into
360 equal parts or degrees : within this circle is a moveable plate, divided like-
wise into 360 parts, and a small steel index. The brass circle in the figure is
marked d, and the moveable plate d. On the standard bar is laid the bar of
metal e, on which the experiment is to be made, as e.

F is a lever, 24- inches in length, fastened to an axis, which turns in two
pieces of brass, screwed to one of the supports, marked b : to the end of this
lever is fastened a chain, or silk line, which, after being wound round a small
cylinder, to which the index in the brass circle d is fastened, passes over a
pulley, and has a weight hung to the end of it : on the axis, to which the
lever is fixed, is a pulley, 4- of an inch diameter, to which a piece of watch-
chain is fastened ; the other end of this chain is hooked to a strong spring,
marked g, and bearing against one end of the metal e.

H is a lever, exactly of the same form and dimensions with the former ; but
the chain fastened to the pulley on its axis, is hooked to the standard bar.* The
line fastened to the end of this lever, after being wound round a cylinder, to
which the moveable plate is fixed, passes over a small pulley, and has a weight
hung to the end of it ; or rather the same line passing under a pulley, to which
the weight is hung, has its other end fastened to the lever f : thus one weight
serves for both levers, as in the figure.

From this description it is plain, that whenever the bar e is lengthened, it
gives liberty to the weight to draw the lever f upwards by its action on the

• N. B. The chain to the former pulley being fastened to a spring, and not directly to the metal «,
is only for the more easy shifting the metals.


spring G ; and the index will, at the same time, by means of the silk line, be
carried forward in the circle; and as the bar shortens, it will return back again;
the same motion will be communicated to the standard bar. The lengthening
the bar the iOth of an inch, will carry the index once round the brass circle,
which is divided into 36o degrees; therefore, if the metal lengthens the 7'200th
part of an inch, the index will move one degree.

To make an experiment with this instrument, lay a bar of any kind of metal,
as E, on the standard bar ; then heat the standard bar to any degree of heat
with a lamp, and mark the degree of its expansion, as marked by the moveable
plate : observe also the degree of expansion of the metal k, by the heat com-
municated to it from the standard bar, as marked on the brass circle by the in-
dex : let the instrument stand, till the whole is thoroughly cold ; then remov-
ing the bar e, lay a bar of any other metal in its place, and heat the standard
bar to the same degree of heat as before, which is seen by the moveable plates
marking the same degree of expansion. Then the index will show the degree
of expansion of the second metal, as it did of the first ; and by this means the
degrees of expansion of different metals, by the same degree of heat, may be
exactly estimated.

ji further Account of the Bones of Animals being made Red by Aliment only.
By John Belchier, F. R. S. N° 443, p, 299.

In the former account, p. 7g, concerning the red bones of the hogs, Mr. B.
mentioned, that the colour was occasioned by bran being mixed with their
common food, after it had been used to clean printed callicoes ; the colours of
which were made, some from preparations of iron, which were the blacks and
purples ; others from preparations of alum, and sacc. saturni, which produces
the red colours ; and that madder root was used to fix these colours on the
cloth. To which of these preparations the colour was owing, could not then
be determined. Some were of opinion, that it was entirely occasioned by the
preparations of iron ; others, that it was the whole blended together. But
to clear up this point, Mr. B. made the following experiments. The first was
made on a cock, by mixing some of the madder root with fig-dust, on which
they feed. The cock dying within ]6 days after his first feeding on the mad-
der, he was dissected, and the bones examined, not in the least expectation of
finding them tinged in so small a time ; but they were found universally of a
red colour. So that, from this experiment it appears, that the madder alone
causes tliis alteration. But why the bones only are aflx-cted, must be deter-
mined by future experiments.

Online LibraryRoyal Society (Great Britain)The Philosophical transactions of the Royal society of London, from their commencement in 1665, in the year 1800 (Volume 8) → online text (page 11 of 85)