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cellular substance. All the other viscera were in a natural state.


A Method of preparing Specimens of Fish, by drying their Skins, as practised by
John Frid. Gronovius,* M. D. at Ley den. 1S1° 463, p. 57.

There are requisite for this purpose, a pair of scissars, with very fine blades,
and sharp points. Small wooden plates of the lime-tree, or wooden trenchers.
A very fine needle. Slips of parchment as large as the fishes. Minikin or
small pins.

Take hold of the fish with your left hand, so as that the belly may be towards
the hollow of your hand, and its head pointed to your breast. Then with the
needle make a wound behind its head, into which introduce one of the points
of your scissars, cutting gently from thence along to the tail. If you would
preserve the right side, the scissars are to be conducted on the left side of the
fin. This being done from the head to the tail, the scissars are to be pointed
deeper, and the flesh divided quite to the back-bone. Then turn the fish with
its back downward, and its belly upward, and proceed in the same manner,
cutting with the scissars through both head and jaws. Take away the brain and
gills. The fish then easily parts, the intestines appear, which may be easily
taken away. The back-bones are then to be cut asunder, the fish is to be
washed, rubbed till it is dry with a linen cloth, and placed on a board, in such
a manner, that the skin, covered with its scales, may lie uppermost, and all the
fins and tail are to be expanded with pins. Let it then be exposed to the sun,
if in summer, or, if in winter, to the fire, till the skin grows quite dry and
hard, when it must be turned, and the flesh exposed to the sun or fire, till it
also is dry ; and then the skin may be separated from the flesh with very little
trouble, and, being put between papers, must be pressed flat. But as a sort of
glutinous matter, in pressing, is always forced out from between the scales and
the skin, a piece of parchment is to be laid under the fish, which is easily sepa-
rated from the scales, as paper always sticks ; for this reason it is necesary, that
after an hour or two, a fresh piece of parchment should be applied: and thus,
in the space of 24 hours, the fish is prepared.

Account of the Fire-ball seen Dec. II, 1741. By Capt, IVilliam Gordon.

N° 463, p. 58.

On Friday the 1 1th of December 1741, about 1 p.m. coming by water from
the city to Whitehall, and near to Hungerford- stairs, there appeared to Capt.
G. between Vauxhall and Lambeth, a body of fire : it sprung upwards in its
ascent almost perpendicular to the horizon, to the height of about 35", in the

* Dr. John Frid. Gronovius, a physician at Leyden, is chiefly known by his work entitled Zoo-
phylacium, in folio, containing good descriptions, accompanied by figures, of noany- rare and curioii&
animals, particularly fishes, insects, and amphibia. ■ ^ _. . • ,., ; •»'


space of a. few seconds, and nearly in form of a large paper kite, projecting
a long tail towards the north-west, not unlike those of slips of paper set on
fire; in this state it continued so long, that he made the waterman lay his oars
in, that he might the more easily observe whether it was the work of art or
nature, as he was in some doubt. It had from its first appearance expanded
itself considerably, so that the extreme breadth was seemingly equal to the
diameter of a full moon arising from a dusky horizon. In this form it conti-
nued ascending for the space of 2 minutes, gently shooting to the north-east,
till it arose to about 45°; then suddenly quitting its tail, which vanished, colour-
ing the neighbouring clouds with a yellow on their separation, it formed itself
first into a ball of fire; then shooting quickly to the south-east in a stream of
light, disappeared, making a noise like a clap of thunder at some distance, and
leaving behind it a smoky substance in its track.

The weather was moderate and cloudy, wind nearly, west south-west. It
continued in sight upwards of 5 minutes.

Concerning the Fire-ball seen Dec, 11, 1741. By the Rev. Mr. William Gost-
ling, of Canterbury. N° 463, p. 6o.

As the fire-ball appeared at noon-day, and the sun shining, few people saw
it, and they could only guess at the course. The best account he had is at se-
cond-hand, from two farmers who saw it together, and make its course from
north-west by north to south-east by south, and right over Littleborn, which is
the first village in the road from Canterbury to Deal. Their way of telling its
course was by saying, it went from Westbere towards Ratling, and they heard
only one explosion.

Observations on Mr. Sutton's Invention to extract the Jbul ^irfrom the Well and
other parts of Ships, with Critical Remarks on the Use of Windsails. By
William Watson, F. R. S. N" 463, p. 62.

As nothing is more conducive to the health of the human body, than taking
a sufficient quantity of wholesome air into the lungs, so the contrary is attended
with pernicious, and often with destructive consequences.

One of the great uses of air in inspiration is, to cool* the blood passing
through the lungs; where nature has provided, according to the excellent Mal-
pighi, that the blood should be distributed through a vast number of exceed-
ingly fine arteries, which are applied all round the thin vesicles of the lungs;

* A very different theory of respiration has been adopted in later times, founded on a more ac-
curate knowledge of the composition of atmospheric air, and on the changes produced in it and
upon the blood during its inhalation into the lungs.


and by this means the blood is exposed to the air under a prodigious large sur-
face, by which the putrefaction is prevented, which, from the alcalescent qua-
lity of that fluid, would otherwise be speedily destructive.

It has been frequently tried, that if a gallon of air be contained in a bladder,
and by means of a blow-pipe inspired and expired by the lungs of a man, with-
out having any communication with the external air; in the space of a minute,
or little more, it becomes heated, and unfit for respiration ; and without the
addition of fresh air, the person would speedily be suffocated. The diving-bell
is another instance of the same kind, where a constant supply of fresh air must
be had, to keep out the water, and refresh the people included.

Though air is absolutely necessary to our existence, and necessity constrains
us inevitably to breathe in it, it may be made a vehicle of most malignant poi-
sons ; as the famous Grotto del Cani in Italy, poisoning air by charcoal, air
impregnated with the fumes of fermenting vegetable liquors, stagnant air,
either alone or mixed with water, soon becomes pernicious and very offensive ;
as in wells dug for supply of water, and disused for some time ; also in the wells
and in the holds of ships, where what is usually called the bulge-water, if the
ship is tight, and the water not pumped out often, it soon becomes so extremely
poisonous, as frequently to suffocate those seamen, who, as the putnps are sub-
ject to be clogged with filth, venture down to cleanse them; and also to affect
persons at a distance with violent head-achs, cold sweats, and frequent vomit-
ings, which continue more or less, in proportion to the distance from the well
of the ship when the injury was received, and the degree of putrefaction in
the water and air.

The air, in ships particularly, is very liable to be vitiated ; not only from the
bulge-water, but from too many people breathing in the same atmosphere;
especially in ships of war, hospital ships, and those used in the Guinea trade
for negroes, where a number of uncleanly people, being stowed too close toge-
ther, heat the air, make it replete with noxious effluvia, destroy the particles
adapted to cool the lungs, particularly the acid nitrous gas, which is so abun-
dant in cool air, and manifests itself not only by the quantity of nitrous crys-
tallizations, which may be collected from caverns of the earth, especially those
open to a northerly aspect, but by exposing pieces of the flesh of animals fresh
cut, or their blood, by which the colours of their surfaces are soon changed
from a dark deep red, to a more lively and florid one. Air deprived of this va-
luable property, and replete with hurtful ones, not only from the people, but
from the stinking water in the well and lower parts of the ship, must produce
the most putrid, if not pestilential fevers.

Though the equilibrium within places confined is maintained by the external



air, yet unless, by openings properly adapted, the air be suffered to pass freely
through, the external air proves as a stopple to the internal, and only mixes
with the next in contact; as is evident from the common occurrence in privies,
which are scarcely offensive in clear weather, but are much so in foul or windy,
from a diminution of the incumbent pressure, when the vapours that have been
pent up, expand to a considerable distance.

To prevent the above-mentioned inconveniencies, and preserve the health
and lives of that valuable part of the nation, the seafaring people, many schemes
have been thought of; particularly the machines of those two very worthy inge-
nious and industrious members of this Society, the Rev. Dr. Hales and the Rev.
Dr. Desaguliers; the first by an instrument which he calls the ship's lungs, in
his treatise on Ventilators, and the latter by a machine, which is an improve-
ment of the Hessian bellows, Philos. Trans. N° 437 ; but as these have been
laid before the Society by the gentlemen themselves, Mr. W. passes them over,
and proceeds to mention the contrivance commonly made use of, viz. the

These are made of the common sail-cloth, and are usually between 25 and
30 feet long, according to the size of the ship, and are of the form of a cone
ending obtusely. When they are made use of, they are hoisted by ropes to about
two- thirds or more of their height, with their basis distended circularly by
hoops, and their apex hanging downwards in the hatch-ways of the ship; above
each of these, one of the common sails is so disposed, that the greatest part
of the air, rushing against it, is directed into the wind-sail, and conveyed, as
through a funnel, into the upper parts of the body of the ship. These must
be hung up and taken down every time they are used, and the supply by this
method is not constant. Though custom has given a sanction to this device,
it is subject to many inconveniencies: 1st, Each ship having commonly three
of these, one to each mast, the seamen are a considerable time in getting their
apparatus ready, and hoisting them up, to make use of. 2dly, They can only
be used in mild weather. 3dly, Near the equator, where fresh air is most
wanted, there sometimes happen such dead calms, that they are useless, by not
having air enough to distend them. 4thly, The air thus admitted passes only
into the upper and more open parts of the ship, so that the well, &c. receive
no change from it ; and it is observed, that sometimes, on using them after
some discontinuance, they drive offensive air into the cabin, and more airy parts
of the ship, like as the pouring some fresh into stinking water makes more
water stink, though in a less degree. 5thly, They are improper to be used in
the night-time, when the people are sleeping between decks. And, lastly, ad-
mitting they had none of the former inconveniencies, their use must be destruc-


tive in hospital ships; where, though fresh air imperceptibly received is abso-
lutely necessary to preserve the crew, as free as possible, from the infectious
breath and exhalations of the diseased and wounded seamen, yet blasts of wind,
pouring impetuously into the very places where the sick lie, must be attended
with such consequences as are too obvious to mention.

To remedy these inconveniencies, to prevent air proving foul even in the wells
and holds of ships, and to cause imperceptibly a large circulation of fresh air
into every part of the ship at all times, Mr. Sutton has invented the following
scheme, in the preceding N° of the Trans, which is useful not only in these
cases, but, by altering some parts, as particular places require, may be applied
to houses, close parts of prisons, wells at land, privies, hospitals, &c.

Nothing rarefies air so considerably as heat, and whenever it causes a dimi-
nution of the density of the air, that part next in contact will rush in, and be
succeeded by a constant supply, till the air becomes of an equal degree of elas-
ticity. Therefore, if a tube be laid in the well, hold, or any other part of the
ship, and the upper part of this tube be sufficiently heated to rarefy the im-
pending column of air, the equilibrium will be maintained by the putrid air
from the bottom, which being drawn out this way, a supply of fresh air from
the other parts of the ship will succeed in its place; which operation, being
continued, will entirely change the air in all the parts of the ship. This prin-
ciple, exactly conformable to the doctrine of pneumatics, is the basis of Mr.
Sutton's machine, which being put in execution on board the Hulk at Deptford,
before the lords of the Admiralty, commissioners of the navy, the very learned
and ingenious president M. Folkes, Esq. Dr. Mead, &c. performed to their
satisfaction, in bringing air from the bread-room, horlop and well of the ship
at the same time, in such quantity, that large lighted candles being put to the
end of tubes, the flame was immediately sucked out as fast as applied, though
the end of one of the tubes was above 20 yards distant from the fire. The
method is as follows:

To boil the provisions of the ship's company, they have a copper, larger or
smaller in proportion to the size of the ship, and number of the crew : this
copper is fixed in ships in the manner as on land, having under it two holes
divided by an iron grate. The first hole, having an iron door, is for the fire ;
the ashes from the grate drop through into the bottom of the other ; the smoke
passes through a chimney, and is discharged as usual. After the fire is lighted,
it is supported by the air from the parts next the ash-pit ; but having, contrary
to the usual custom, adapted an iron door, like the former, made very tight,
to prevent the ingress of air, the fire would soon be extinguished, if not sup-

4c 2


plied by some other aperture ; in order to which, one or more holes are made
through the brick work in the side of the ash-pit ; and tubes of lead or copper
fitted closely in the holes, and made fast, are laid from thence into the well
and other parts of the ship ; by which means the air next the bottom of the
tubes rushes through them, and the foul air succeeding is transmitted through
the fire, and passes off, without offending, by means of the chimney; and a
supply of fresh air from the other parts of the ship continually fills the place of
the former, the fire requiring a constant support, which support will be want-
ing, not only during the continuance of the fire, but while any warmth remains
in the fire-place, copper, or brick-work, as was observed on board the hulk at
Deptford, where the draught of air through the tube lasted above 12 hours
after the fire was taken away. This being considered, as the dressing the provi-
sions for a number of people will take up some hours every day, the warmth of
the brick-work and flues will continue a draught of air from one day to the
next. Mr. Sutton proposes thus to circulate the air by the same, and no greater
expence of fire than is used for the necessities of the ship. The operation of
the machine will be equally useful in large as small ships ; for the greater the
number of people they have on board, the larger quantity, and longer continu-
ance, of the fire will be necessary to dress the provisions ; and therefore there
will be required a greater quantity of air to support that fire.

There is also, especially in large ships, not only a copper, but also a fire-
grate like those used in kitchens : that the heat and smoke of this also may not
be useless, an iron tube may be fixed behind the grate, and inserted quite
through the deck, so that one end of it will stand about a foot, or little more,
in the chimney above the brick-work, and the other will enter into the hold,
or any other part of the ship ; so that the upper end being heated, the draught
of air will be supplied from below, as in the other case. This likewise was tried
on board the hulk, with an iron tube about 2 inches and a half in diameter, and
the lighted candles held at the bottom of this tube were extinguished as fast as
by any of the other.

It may be objected, that a number of tubes take up too much room, especially
in merchants' ships, and are subject to be broken or injured by loading or un-
loading : to remedy which, it is advisable, that only one tube of a convenient
size be made fast unto the side of the ash-pit, and, as soon as it comes through
the main deck, to compress it, not too close ; and it may be divided into as
many ramifications as may be thought necessary, especially as the bread-room,
store-room, &c. cannot be kept too sweet, a branch for each of these, and
these branches be carried between the beams which support the deck, till they


come to the side of the ship, and there let down likewise between the beams
into the places intended ; by which contrivance their operation will not in the
least be obstructed, and the tubes be secured from any accident.

The simplicity of this machine, it being so little cumbersome, its operation
without any labour to the seamen, the small expence to put it in execution, and
maintain it, besides the before-mentioned considerations, are other arguments
for its general use.

The Method of mahivg Soap-lees and Hard Soap, for Medicinal Uses. By M.
Claud. Joseph Geoffrey, of Paris, F.R.S. N° 463, p. 71.

To make the lye, take, (says Dr. G.) of the best calcined lime, that has
been the least exposed to the air, 5lb ; of good salt of kali or glass-wort of Ali-
cant, pulverized, and passed through a fine sieve, lOlb. Divide the lime and -
the salt of glass-wort, called in England barilla, into 2 equal parts ; then put
the lime, broken into pieces not larger than an egg, into new stone pans, and
cover it with as much salt of glass-wort as is designed for each pan. Pour,
afterwards on these several mixtures hot water, by little and little, to give time
to the lime to open itself, till it turns into a sort of meal, which will happen
after having poured 3 half-pints * into each pan. Then add to it the rest of
the water that is required, stirring this mixture with a stick of white wood ;
when there are 18 or IQ quarts of water in each pan, there is enough for dis-
solving the salts. In this state the pans are left for 12 or 15 hours; after
which this lye is filtrated through brown paper, supported by a coarse cloth,
fixed to the 4 corners of the filtering frame. When the whole mass of the lye
and of the lime is well drained, put it into a clean iron pot, with 10 quarts of
water, to the quantity taken out of each pan, and let it boil an hour ; then
filtrate it a 2d time. Afterwards it is put into another clean iron pot, and as it
evaporates by degrees, it is filled up again with the first lye prepared, without
boiling. Let it continue to evaporate till the 28 quarts of water, that have
been used for making the lye of the mixture that was at first put into each of
the pans, be reduced to 2 quarts and half a pint, or so long till a small salinous
film forms itself on the top of the lye. This liquor turns almost black, because
it corrodes the iron ; but this is no inconvenience, as will appear hereafter. In
this state of concentration, if we let a drop of it, while hot, fall on a piece of
glass, it will be very quickly covered with a fine and greasy film, which makes
it look as if it was congealed. At the bottom of this lye is found a salt in flakes,
which, being melted in a crucible, produces a lapis infernalis of a strong caustic

* The Paris pint is near a quart English. — Orig.


power. We may know also, that the lye has acquired the necessary degree of
concentration, when, becoming more active, we see, that the edge of the pot
that has been wetted by it, turns red, while the lower part of the side all around
down to the surface of the liquor, takes a greenish colour. Then the pot must
be taken from the fire, and the liquor left to cool so far as to be put into glass
bottles without cracking them : the bottles ought to be carefully corked, not
only to prevent the salts contracting a dampness from the air, which would
lessen the degree of forced concentration, which has been acquired by the eva-
poration, but also to preserve what is sulphureous, which would exhale, if the
liquor remained long exposed to the air ; for probably that sort of hepar, formed
by the union of the caustic salt with the sulphur of the ashes of the glass-wort,
ought not to be neglected.

Now, the better to direct those who wish to work after these processes, and
to furnish them with the degrees of concentration this lye is to have, in order to
make with oil a solid soap out of it as speedily as possible, take a glass phial
with a narrow neck, and fill it with clear water up to a mark made on the neck.
That now used by the Dr. being filled up with water to that mark, contains
just 3 oz.: afterwards empty it carefully, and instead of clear water, fill it with
that concentrated lye as far as the foresaid mark, and then weigh it. If the
weight be increased 84- or 9 drs., that is, near 3 drs. in each ounce, this
shows that the lye is neither too much nor too little concentrated. An hydro-
statical balance, a water-poise, and other instruments, might also give this
degree ; but in the country they are not at hand, and he judged it best to
point out only what is most easy Soap-boilers use for this end a fresh egg ;
if one half of it sinks into the lye, they judge the latter to be of the first
strength, that is to say, that this is the lye which they ought to employ last
of all in their manufacture ; if the egg sinks in to 2 thirds, the lye is called
the second ; and, lastly, if the lye covers the whole surface of the egg, it
will be called the first, and will be that with which they begin their opera-
tion or boiling. But this way of trying has not all the exactness which can be
desired, because all hens' eggs have not the same specific gravity. Besides,
as he makes his soap without fire, he must take the lye that is most concen-

Lest the iron, which is corroded by the lye, should enter into the composition
of the soap, we need only evaporate the lyes in earthen pans put over a balneum
mariae : but as this evaporation is slower, it will consume much more coals.
We may even see m tnose pans by different marks, that the liquor approaches
the desired degree of concentration, partly by a piece of wood marked with
notches, partly because if there is the least ferruginous speck in the earth of


those pans, the liquor will penetrate that ferruginous place, and make a spot
there. By using earthen pans you will get a very limpid liquor, and which
will only have a very pale straw-colour, even after its perfect concentration.

The lye prepared in iron, being kept for some time, clears up, and leaves a
black sediment, which is that part of the iron which it has separated by corrod-
ing the sides of the pot. And yet this ferruginous lye, together with the oil,
will form a white soap, if we let that black sediment precipitate. This sediment
is true iron. The Dr. has made himself sure of it, by calcining it in a crucible,
after having inoistened it with oil.

One ounce of concentrated lye to the degree above mentioned, contains 3
drs. 18 grains of salt : when this salt is dissolved again in distilled rain water,
and filtrated, it yields 3 grains of coarse earth, which cannot penetrate the
pores of the filtre.

To use it to make soap, take 1 part of it to 2 parts of the best oil : mix them
gently in a China bowl, stirring them with a spathula of white wood, till both
liquors are come to the consistence of butter that is churning : this thickening

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 65 of 85)