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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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it, as there was at Cambridge, where it lasted above half an hour, and conse-
quently was not so violent. Some few booths in Sturbridge-fair were blown
down. The course of the storm was from Huntingdon to St. Ives, Erith, be-
tween Wisbeach and Downham to Lynn, and so on to Suetsham. Very few trees
escaped: the barns that stood the storm, had all their roofs more damaged to
the leeward side than to the windward. The storm was succeeded by a pro-
found calm, which lasted about an hour; after which the wind continued pretty
high, till 10 o'clock at night.

Concerning the Remains of a Roman Hypocaustum or Sweating-room, discovered
under-ground at Lincoln, Anno J 739- By Mr. T. Sympson. N°46], p. 855.

Some labourers being employed to dig a cellar in an outhouse, fronting the
west end of the Minster, and adjoining to the Chequer-gate, they found 1 or

3 stone coffins, which had probably lain there ever since the demolition of the
ancient parish church of St. Mary Magdalen, to make way for the foundation
of the cathedral, and its appendages; but going lower, about 10 or 11 feet
deep, they found some building; and at 13 feet they struck into the corner of
a vault. Mr. Sympson took it to be a Roman hypocaustum ; he had the dimen-
sions of it taken, as in the plan, pi. 13, fig. 1, and the profile, fig. 2.

A is the praefurnium, stoking-place, entrance or place where the fornacator,
the stoker, stood to manage the fire. It is 3 feet 6 inches square, its height
not certainly known, because of the rubbish which lay at the bottom.

B, the fornax, furnace, or fire-place, built of brick, and arched over with
the same. Its length from e to g, 5 feet 6 inches ; its height 3 feet at e, but

4 feet at p, rising gradually; 3 feet 6 inches long from e to p, and 1 feet wide
between e and f; 1 feet long from p to g, and but 19 inches wide between p
and G.

c, the alveus, or body of the kiln, 21 feet 4 inches long; 8 feet 4 inches
broad; and 1 feet 4 inches high. The floor is made of a strong cement com-
posed of lime, sand, brick-dust, &c. which the masons of that country call
terrace-mortar. On this floor stand four rows of low pillars, made of brick,
II in a row; the outside rows round, the two inner rows square; the round ones


are about 1 1 inches diameter, the others 8 inches square ; each standing on a
brick II inches square, as at fig. 4, and 2 inches thick; the shaft 2 feet high,
on which lies another brick likewise 2 inches thick, some 17, 18, and others
19 inches square, as at fig. 3, which represents the profile of two square pillars
with the square bricks at top and bottom, which make the whole height of the
alveus 2 feet 4 inches. The pillars, both round and square, are jointed with
mortar, and that very clumsily ; the round pillars being composed of 10 courses
of semicircular bricks, as at fig. 4, A, laid by pairs; the joint of every course
crossing that of the former at right angles, as at fig. 4, c; with so much mor-
tar between, that the two semicircles rather form an oval, and so the pillars
look at first sight as if they were wreathed; the square pillars are composed of
13 courses of bricks, as at fig. 4, b; 8 inches square, as at fig. 4, d; these
bricks being thinner than those which compose the round pillars.

On the top of these pillars rests the testudo or floor of the sudatorium or
sweating-room, fig. 2, hi, which is composed thus: first, there is a floor of
large bricks, 23 inches long, and 21 broad, which lie over the square bricks on
the tops of the pillars, as at fig. 3, the four corners of each brick reaching to
the centres of four adjoining pillars, as at fig. 5, where only one of these larger
bricks is represented, as it bears upon 4 of the su)aller bricks with their pillars
under them. On this course of bricks is a covering of cement 6 inches thick,
and on that is set a tessellated pavement ; the tessellae of the corner uncovered,
K, in fig. 1 and 2, are of a whitish colour.

L and M, in fig. 1 and 2, are two tubuli or flues, 12 inches wide, and 14
deep, for carrying ofi' the smoke; the bottoms of them are even with the bot-
tom of the alveus, and they are carried on the level about 1 5 feet, under an-
other room by the side of the hypocaustum, and then it is presumed they turn
upwards. The walls of this room were plastered, and the plaster painted red,
blue, and other colours, and its floor tessellated white; no figures are discern-
ible in either painting or pavement. This pavement, which is on a level with
the testudo of the hypocaustum, is about 13 feet below the present surface of
the ground, so deep is old Lindum buried in its ruins!

The workmen, in digging up this pavement, struck into the flue m, 3 feet
from the north east corner of the hypocaustum ; and opened it to the very
corner k, which showed one of the round pillars, and thus the whole was dis-
covered. In sinking the hole nk, at 5 or 6 feet depth, they came to the wall,
which was dug up by pieces with the rubbish, before they came to the pavement.
This had been the wall of a room under which the tubuli ran, by the side of,
and not over the alveus, but on the east side of it.

Mr. Sympson got a youth to creep in at the opening made at k, and take the


dimensions of the several parts, who, the alveus being quite black with smoke,
returned like a chimney-sweeper, but could not take the exact measures of the
fornax and praefurnium, on account of rubbish he found in them; therefore
Mr. Sympson, being desirous to inform himself thoroughly of all the parts of
this curious piece of antiquity, with the leave, and at the expence, of the pro-
prietor, caused another hole to be sunk l6 feet deep, and by driving a level op,
fig. 1 and 2, he broke into the middle of the fornax; and, having cleared it of
rubbish, found its dimensions as above, and that the bottom of the narrowest
part between f and g, was raised 18 inches higher than the bottom of the part
between e and f.

The praefurnium was covered over at top with a large flat stone. The fornax,
and the two square pillars in the alveus fronting the opening of the fornax,
were greatly impaired by the fire, which must have been very violent; some
small fragments of wood-coal were thrown out among the rubbish in the bottom
of the fornax; whence probably it was heated with wood.

At the conclusion of the account, Mr. Sympson gives the following remark
on a passage in the second letter from Mr. Baxter to Dr. Harwood, concerning
the hypocausta of the ancients, printed in these Transactions, N° 306. " Mr.
Baxter says, the hypocausis was called alveus and fornax; but, with due defer-
ence to that learned gentleman, says Mr. Sympson, I humbly apprehend them
to have been distinct parts of the whole, which was called hypocausis: the
ground of this conjecture is; in the first place, it would hardly be possible to
make a fire in that part of this hypocaust, which he calls the alveus; much less
to come at it to manage it, being so low, and so crouded with pillars, as to
admit only a slender person to crawl among them, and that not without diffi-
culty. In the next place, the floor does not seem designed for it, nor are there
any appearances of ashes on it ; and further, that the fornax was where he has
placed it in this, appears not only from the structure of that part, but from the
bricks being much burnt, and pieces of wood-coal being found in it; whereas
in the alveus, the bricks are only black with the steam and smoke being drawn
through it by the tubuli." He might have added, that only those pillars in the
alveus, which faced the mouth of the fornax, had suffered much by the fire,
the others not.

That hypocaust, described in N° 306, abovementioned, must have been a
much hotter room than this; for, instead of the flues being carried under an-
other room, the walls of the sweating-room itself were hollow or double, and a
great number of flues carried up between them all round the room. A curious
model of this was to be seen in the museum of the Royal Society.

This hypocaust may serve as a model for malt-kilns, or for drying hops, &c.


Of a Capricorn Beetle,* Jound alive in a Cavity within a sound piece of Wood,
and of the Horn of a Fish struck several Inches into the side of a Ship. By
C. Mortimer, M. D. Seer. R. S. N° 461, p. 801.

About Michaelmas 1 728, Dr. M. went to Portsmouth with some friends, where
having taken a view of his majesty's yard and docks for building ships of war;
and satisfied his curiosity in examining several ingenious contrivances used in
naval architecture; Mr. Bankley, the clerk of the survey, invited him to his house,
where he showed him the insect as represented in fig. 1 and 2, pi. 14. The
people of the yard were much alarmed at it, none knowing what to make of it,
and all imagining it was venomous. On opening the piece of wood, which was
tied together with a packthread. Dr. M. found this animal yet alive, and moving in
a large cavity in the middle of the wood, which appeared otherwise sound, hav-
ing no visible entrance into it. This beetle being turned out on a sheet of
paper, crawled about. Mr. Bankley gave the following account of it: " This
insect was found August 26, 1728, in splitting a piece of exotic wood into two
pieces, cut across the grain 4^ inches thick, taken up in the hold of his ma-
jesty's ship Bredah, when in the dock at Portsmouth, after her return from the
West Indies: it lived upwards of a month afterwards. The hole in which it
was nourished, was 5 inches deep, and 2^ inches by 14- inch broad, in the great
piece; 2 inches deep, and 24 inches by 1^ inch broad, in the smaller piece.
There was not the least sign of any defect on the outside of the wood, but it
appeared very fair and sound ; the inside was porous, having a grain like cedar,
but in colour not unlike yellow sanders."

On examination, Dr.M. found this insect to be a sort of scarabseus called capri-
cornus from its long horns; which in this were very much crumpled, and partly
broken ofl'' against the wood in its confinement; its wings were likewise crum-
pled on the same account. The females of these insects usually lay their eggs
in the crevices of the bark of trees; so it is probable, that as soon as this insect
was hatched in form of a worm, it gnawed its way through the bark into the
wood; and that afterwards the hole it had made in the wood, closed towards
the outside; and the worm, still continuing to gnaw deeper, formed the large
cavity; and then taking its perfect form of a beetle, remained in that hollows
place, where the sap of the tree arising, might have supplied it with nourish-
ment, and even air, since it is known, by various experiments, that air will in-
sinuate itself whereever such fluids, as contain air in them, can penetrate.

• This beetle was a species of the Linnaean genus cerambyx, and perhaps the female of cerambt/x


Dr. M. had seen in the magnificent museum of Sir Hans Sloane, Bart, a piece
of wood, sound without, having a cavity within, wherein was found alive a sort
of beetle, but he thought of a different species. It came from Jamaica, if he re-
membered right.

At the same time, that curious gentleman, Mr. Bankley, showed him the
horn of a fish* that had penetrated above 8 inches into the timber of a ship,
see fig. 3 ; and gave the following account of it : " His majesty's ship Leopard,
having been at the West Indies, and on the coast of Guinea, was ordered by
warrant from the Navy Board, dated Aug. 18, 1/25, to be cleaned and refitted
at Portsmouth for Channel service ; pursuant thereto, she was put into the
great stone- dock ; and, in stripping oflT her sheathing, the shipwrights found
something that was uncommon in her bottom, about 8 feet from her keel, just
before the foremast ; which they searching into, found the bone or part of the
horn of a fish of the figure here described; the outside rough, not unlike seal-
skin, and the end, where it was broken off, showed itself like coarse ivory.
The fish is supposed to have followed the ship, when under sail, because the
sharp end of the horn pointed toward the bow ; it penetrated with that swift-
ness or strength, that it went through the sheathing l inch thick, the plank 3
inches thick, and into the timber 4^ inches."

With what prodigious force must this fish have moved? for had it met the
ship, the motion of the ship would have assisted the penetration of the horn ;
but the direction of it pointing from the stern towards the head, shows that the
fish struck against the ship, either while at anchor, or that it overtook it,
while under sail ; in which case the force of the fish must have been still greater;
and this was probably the case, because nobody in the ship remembered the
shock. Several able workmen on the spot assured Dr. M. that, with a hammer
of a quarter of a hundred weight, they could not drive in a pin of iron, of the
same form and size, into such sort of wood, and to the same depth, in less
than 8 or 9 strokes.

Abstracts of the original Papers communicated to the Royal Society by Sigismond
Augustus Frobenius, M. D. concerning his Spiritus Fini JEthereus. Collected
by C. Mortimer, M. D. Seer. R. S. N° 46j, p. 864.

Dr. Frobenius being dead, and some learned chemists at Paris, in Germany,
and in Italy, having endeavoured in various manners, and with different con-
trivances, to make this ethereal spirit; Dr. M. thought it would be acceptable

• This fish was probably the scomber gladius, Bloch. Xiphias platypteris. Shaw's General


to the curious in England, to give tliem an abstract of the three papers the
Doctor communicated to the Royal Society concerning his Spiritus Vini ^Ethe-
reus. The first he gave in on Feb. \g, 1729-30, along with wliat is printed in
N° 413 of these Transactions, but was desired by the author not to be pub-
lished at that time. In this paper he says, you must " take of oil of vitriol,
and the highest rectified spirit of wine, equal parts by weight, not by measure;
that the oil of vitriol was to be poured by little and little into the spirit of wine,
because they will grow hot on mixing; that they should be shaken often, that
they may mix thoroughly; then to be digested gently in a glass retort, and a
large receiver to be applied and luted on, lest the subtile spirits should fly away:
then distil them in an athanor, in gentle digestion, for 3 days; and pour back
the distilled liquor, till the liquor in the recipient appears double, or of two
sorts. Thus far, he says. Sir Isaac Newton was acquainted with the process."*

He then proceeds almost in the very words of the late Mr. Godfrey [Han-
ckewitz] as printed in the Transaction quoted above.

He concludes, by telling us, that the first part of the process, till we come
to the separation of the two liquors, is mentioned by Caneparius, in his book
de Atramentis, first printed at Venice, and afterwards at London, then by the
great Mr. Boyle, afterwards by Sir Isaac Newton; that Dr. Stahl, and Professor
Hoffman, were the first in Germany who knew the first operation from Kun-
ckel; but neither of them brought it to perfection, or knew the effects of it.-f-
In France M. Homberg undertook an experiment somewhat analogous to this,
with sulphur and oil.

The second paper was communicated on the 12th of February 1740-1, in
Latin, and contains an ample account of the whole process, with improvements
and additions: but as the author in his third paper, given in Feb. IQ, 1740-1,
in English, says that that is the truest and most advantageous process. Dr. M.
presents it as follows, only subjoining the differences and additions in the se-
cond paper, by way of note or explication.

Take 4 lb. in weight of the best oil of vitriol, and as much in weight of the
best alcohol, or the highest rectified spirit of wine.

1. First, pour the alcohol into a chosen glass retort; then pour in, by little
and little, 1 oz. of oil of vitriol; then shake the retort, till the two liquors are
thoroughly mixed, when the retort will begin to grow warm ; then pour in more
of the spirit of vitriol, and shake it again ; then the retort will become very

• So long ago as the time of Rayraund Lully this process was in use; see his Epist. Accursatoriai
p. 327, and Weidenfeld's Secrets of the Adepts, p. 251. — Grig.

+ But Baron •*•», at Vienna, knew the whole process, and it is said Frobenius learned it of him.
— Orig.



hot. Do not poiir in the spirit of vitriol too fast, or too much at a time, lest
the glass retort, by being heated too suddenly, should burst. You must allow
about an hour's time for pouring in the spirit of vitriol, not pouring in above
1 oz. at a time, and always shaking the retort, till the whole quantity of the
ponderous mineral spirit is intimately united with the light inflammable vinous

2. In the next place, examine with your hand the heat of the glass retort,
and have a furnace ready, with the sand in the iron pot, heated exactly to the
same degree as the retort has acquired by the mixture of the 2 liquors ; take
out some of the sand, and, having placed the retort in the middle of the iron
pot, put in the hot sand again round the retort, and apply a capacious receiver
to it ; set it into cold water, and wrap it over with double flannel dipped in
cold water.

Raise the fire gradually,* that the drops may fall so fast, that you may count
5 or 6 between each, and that beside this quick discharge of the drops, the
upper hemisphere of the receiver appear always filled with a white mist or
fumes : continue this heat as long as they emit the scent of true maijoram. -f-

As soon as the smell changes to an acid, suffocating like that of brimstone,
take out the fire, and lift the retort out of the sand, and change the re-
ceiver ; for all that arises afterwards is only a mere gas of brimstone, and of no
use. X

If you do not use the greatest precaution, the liquors in the retort will run
over ; the fire must cease, as soon as the aethereal spirits are gone over ; for
there remains behind an oleum vini, which is extracted by the force of the
acid out of the spirits, which will arise, run over, and often cause ex-
plosions. §

* Force it from the beginning with a pretty strong fire, that not only the spirit of wine be carried
over, but the oil of vitriol along witJi it j which will most certainly happen, if a middle degree of
heat be kept up, between a reverberatory heat, and the other degrees of fire. For the spirit of wine
being mixed with the vitriolic acid in equal weight, but by unequal measure j the spirit taking up
double the room of the oil, does in a wonderful manner make up the deficiency of the highest degree
of heat. — Orig.

f Towards the end, the scent will more resemble that of arrack ; continue this heat for about 3
hours, till the scent becomes offensive, and like that of gas sulphuris. — Orig.

X At this time you will see black froth arising, which will certainly burst the glasses, and destroy
the work, if continued.— Orig.

§ The retort with its receiver being removed, set them by in a cold place ; and when all are
thoroughly cold, separate the receiver from the retort. There will be two different liquors in the
receiver, which pour off through a glass funnel into a glass bottle, which stop up very care-

The liquor will be of two sorts ; that which swims at top, inflammable, of the nature ri <I>A«YirS;


The 2d day, when the glass is cold, infuse the remainder, with half as much
alcohol ;* and distil again as before, and you will have the same. The 3d day
again, with as much, and proceed as at first, it gives it again. Go on as long
as you can obtain any of the aethereal spirit, till all turns to a carbo. Then se-
parate it, and alcalize it with spirits of salt ammoniac made without spirits of
wine, till all effervescence ceases ; and distil it once more e balneo iiiariae. So
is it ready for experiments. -|-

There are more products to be got from this process ; as, 1st. a balsamic oil.
2dly, a terra foliata tartari of a glittering nature, not fusible, as is the com-
mon, prepared with wine-vinegar, and fixed salt, which is of great use in me-
dicine. And, Sdly, a purple earth out of the caput mortuum.

The Doctor proposed at some subsequent meeting, to exhibit 4 other simple

that which sinks to the bottom, like gas sulphuris, a sulphureous acid. Separate the one liquor from
the other, by the separating funnel (pertritoreum). — Orig.

* I suppose he means, pour in half as much fresh alcohol, as you did at first, that is 2lb. weight,
to the liquor remaining in the retort. — Orig.

+ The above-mentioned liquors are to be purified from the strong-smelling sulphur, and superflu-
ous acid, which is performed in the following manner : Pour the liquor, which swam at top, into
a phial ; drop into it, drop by drop successively, a sufficient quantity of spirit of sal ammoniac, pre-
pared either from salt ammoniac with quick-lime, or from salt ammoniac, and salt of tartar, with
conomon water, and not with spirit of wine : every operator knows the quantity ; viz. continue dropping
in of such spirit upon the liquor of the phlogiston, till all effervescence ceases, and all the acid taste,
with the sulphureous smell, vanishes, being precipitated by the volatile alcali to the bottom.

3dly, Let the whole liquor be rectified in a fresh retort by a most gentle heat of a balneum mariae,
or of a sand bath as hot as that of a person in a fever ; and then keep it for chemical uses.

4tlily, The inferior liquor is to be purified as well as that which swam on the top; but it must be
done by oil of tartar per deliquium, till all ebullition entirely ceases. By evaporating all tlie humidity
of tliis liquor, you will have a peculiar tena foliata tartari, which, being reduced into a calx, shines
in the crucible like oriental pearls, or a peacock's tail. This earth has nothing of a pungent taste,
and is to be esteemed as a sheet-anchor in the most ardent fevers.

This earth is of diverse colours, but it is not the common vulgar terra foliata tartari ; for it does
not flow in the fire, nor has the same taste as the common. The common is made by pouring dis-
tilled vinegar on fixed salt of tartar, till an entire saturation is made. The uses of this were formerly
known, and I know not by what fate (says the doctor) it is coming into use again now. I thought
proper to mention the difference of these preparations, because I am able, from innumerable experi-
ments, to demonstrate a real diversity in them. I shall seem to have dwelt loo long on one thing,
but I hope I shall be the less blamed, since I design to show, that there are several ethereal liquors
besides this above described ; for there are not only such (<I>a<ivis-ik«,) or combustible fluids, but there
are likewise saline fluids, and also some quite insipid, being a mixture of combustibles differently gra-
duated, and extracted by no other heat unless their internal fire. In a word, as many spheres as
there are of the elements, so many ethereal, or (if you rather chuse to call them so) aerial liquids,
viz. the aether of the earth, of the water, of the air, and of the fire : which, with the leave of the
Royal Society, I intend shortly to lay before them. — Orig.

3 z 2


sethereal spirits, but of saline origins, equally subtile with this sethereal spirit of

Soon after this the Doctor died, and never discovered any thing relating to
these elementary aethereal liquors ; only in a paper he left in Dr. M.'s hands, he
gave these few hints of their nature.

There are 4 spheres opened, one of the earth, one of the sea, one of the
air, and one of the heaven. Whoever therefore knows how to extract the
essences out of vitriol and nitre, whose centres are salt, (and the surface of the
earth is salt), possesses

1. The salt of the earth. 1. The salt of the sea is made from the sphere
of the sea, and common salt. 3. That of the air is made of sal ammoniac and
salts of vegetables. 4. The essence of fire is made soon and easily from a
concentrated spirit of wine, or of vegetables. Thus the four genuine elements
of nature are obtained.

Of the Fire-ball seen in the Air, and of the Explosion heard, on Dec. 11, 1741.
By LordBeauchamp. N''46l, p. 870.

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 62 of 85)