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PROCEEDINGS

OF THE

ern ear TEI EATON

ROYAL IRISH ACADEMY.

OSE NORE TORN te

VOL, I.

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DUBLIN:
PRINTED BY R. GRAISBERRY,

PRINTER TO THE ACADEMY.

MDCCCXLI.

SUE

CONTENTS.

VOL. I.
———
1836—1837.
ConrrisuTions to the History of Pyroxylic vias and the derived
Combinations. By Robert J. Kane, M.D. - » » pagel
On the Laws of Reflexion from Metals. By el Mac Cullagh,
Eo Ne 2
On the Affinity of he, Hiberno-Calte, oH Phonican Languages
By Sir William Betham. . . . 8, 63
On the Propagation of Light in unerystalized Media. By the
Rev. Humphrey Lloyd, A.M. . - . 10, 25
On the Composition of Thebaine. By Robert r mune M. De eg 2

On the Seals of Ireland, (Phocide.) By Robert Ball, Esq. . . 17
On Modern and Ancient Ring Money. By Sir William Betham. 20

On the Annals of Kilronan, or Book of i O’ 5 ered ae the
Rev. James H. Todd, AM. . . 22

On the probable Nature of the Light fraeiestieea be the Hibcibit
and by Gold Leaf. By James Mac Cullagh, Esq., A.M. . «© 27

On the Laws of Crystalline Reflexion and “gecgeet oa By James

Mac Cullagh, Esq., ALM... . iver dct Tanenpee:
Notice of the Occurrence of Anatifa Vitrea of Lamar on the se
Coast. By Captain Portlock, R.E. . . = - 30

On Eblanine, a Substance ange Ds Mr. ena By Wiliam
. 33

Gregory, M.D
On the Cabiric Micievies aif Phieniian “Antiquities By Sir
William Betham. hes 34, 63
On an Irish MS. called the Book of Mae Fini By Geonge
Petrie, Esq. ~ ‘
Notice Seeneotne the ene Bovcak of tlie ith January, 1807.
By the Rev. Humphrey Lloyd, A.M. . . 38
Notice of an Irish MS. of the Four aes of the seventh Centary.
By the Rev. James H. Todd, A .
On the Combinations aa from Preset Spirit By! Robert

J. Kane, M.D. : 42, 58

1V CONTENTS.

On the Specific Heats of the Aeriform Fluids. By James
Apjohn, M.D. «. . . . . page 44

On the alleged Discovery of. a MS. Tr aeaen of tie Hide of
the Pheenicians, by Philo Biblius. By the Baronde Donop. . 47

On some remarkable Salts, obtained by the Action of Ferrocyanide
of Potassium on the Sulphovinates and Ace By
William Gregory, M.D. .. . Pree)

On a new Variety of Alumn. By Tae a, M. D. Heese Beco
On some peculiar Habits of Otus Bear wy ates. By Gores Port-

locksBRAB vee oes 52
On some general Properties of the ae Sections. By janes

Booth, Esq. ..- . - 53
On Fluorine. By Geor ee J. Kaos, Bs. ; ae ae Rev. Tice

Knox. . . 54

On an ee etree e, oe ne in certain eae Rocks in
the County of Galway. By Robert Mallet, Esq. . . . - . 56

On Dumasine. By Robert J. Kane, M.D. . . . . 58
On the Chronology of Egypt. By James Mac Cullagh, Esq, 2p cr M. 66
On the Antiquities of Tara Hill. By George Petrie, Esq. 68, 71, 75
On the relative Magnetic Intensity in pee ee nee and

Edinburgh. By A. D. Bache, Esq. . . 71
Notice respecting the ee or Boomerang By Joseph s.
Moore, Esq. . - + - 73
Investigations respecting Equations of the Fifth Degree. By Sit
William R. Hamilton, A.M. 76
On the Possibility of transplanting the Cotes, with’ the View of
relieving Blindness. By Samuel L. Bigger, Esq. . - .- 81
On the Composition of certain essential Oils. By Roheek I.
Kane, M.D. .. . 83

On Atmospheric Electri icity. iB Edward s. Clarks, ath + elee86
On a new Gaseous Compound of Carbon and pai By Ed-

mund Davy, Esq. -... .- aside) RCS
On the Properties of Surfaces of fhe: Second Gu By James
Mac Cullagh, Esq., ALM. .. . Nie: Been es)
On a New Rain-guage. By the Rev. ae ioe) 2s sapeeRees OO
1837—1838.
On the Nature, Age, and Origin of the Sanserit WAENgy and
Language. By the Rev. Charles W.Wall,D.D. . . . 97
Inaugural Address of the President. . . . ae 107-
Memoir of the late President. Px fhe Rey. Joseph H. Singer,
D.D., Secretary... . 121

On the Eugubian Teepeipein By Sir William Pe dcan! bie SUR

On the Antiquity of the aie or asengaid ah, Samuel Fer-
guson, Esq. .....-... - . 180, 133

CONTENTS.

Account of a Charter granted to the ets of ee By the

Rey. James H. Todd, B.D. . . 7 ee pope
Extract from a Letter from M. D’ Abbadie to ‘lip Rev ok -
Lloyd.

On the Diurnal March of ‘he i di Néedle, on tie 31st of
August and 13th of evar 1837. By the Rev. Humphrey
Lloyd, A.M... . as Pe. MB VRE eR Re

Notice ofa remarkable Collection of sigs Circles, Cairns, &ce., in
the Townland of Carrowmore. By George Petrie, Esq. .

On the Medals and Medallists connected with Ireland. BY the
Very Rev. the Dean of St. Patrick’s.

On the Ancient Spat ee of Gaul and the British Islands “By
William West, M.D. .

On the Motion of the Boomerang. By Mr. ‘Carrol arid ee. HL
Lloyd. ; :

On the Amount of Rain j in ie Months of August September, -
October. By the Rev. Thomas Knox.

On some Snow Crystals observed on the 14th of January, 1838.
By W. Thompson and Robert Patterson, Esqrs.

On the annual Decrease of the we in Dublin. BY itis Rev.
Humphrey Lloyd, A.M. - :

Account ofa Cromlech near Bote ae iagned ina Tite fin Dr.
Hibbert Ware to Sir William Betham.

On the Sulphates and Nitrates of gee By Ronee J.
Kane, M.D. . .

On the ae of a new * Voltaic i adbination: By Thanks
Andrews, M.D. .

On a new Optical enc By j ames ee Cullagh, Esq. 5 nN M.

On the Years and Cycles of the ancient Bergan, rl the Rev.
Edward Hincks, D.D. . . - 160,

On a new Compound, SE of wane ire of aes ale
and the Essential Oil of Cinnamon. By James Apjohn, M.D.

On the Declination Instrument employed in the Magnetical Obser-
vatory of Dublin. By the Rev. Humphrey Lloyd.

On an a in the ae rere By E. 8. Clarke,
Esq. . :

On the poe of Ammonia Compousi By Robert J.
Kane, M.D

On ancient Trish ates a? Bells. By Gea ss Petr’ ie, pee

On the Irish Hare. By William Thompson, Esq. shies

On an hitherto unobserved Force of Elevation and aa
By Robert Mallet, Esq. :

‘Remarks on the ‘“ seine cate By Bhd Fer gu
son, Esq.

On the Ammoniacal ad pie Basic Oe iaae of tite e Copper ie
Silver Families. By Robert J. Kane, M.D. .

135

136

138

140

180

182

vi CONTENTS.

Report of the Committee of Antiquities, relative to an ancient Tomb
discovered in the Phenix Park. . . . « ee ea page

On the Action of Arseniuretted Hydrogen on Sulphate of Copper,
and on the Manganese Alumn aaeet by Dr. pole By
Robert Kane, M.D. - . aHReK KS

On Etruscan Hand Mirrors. By Sir William Bashan

On the ancient Tomb recently discovered in the Tumulus in the
Phenix Park. By Sir William Betham. .. . :

On the Fifth Eugubian Table. By Sir William Betham.
Remarks on the “Antiquitates Americane.” By George Downes, Esq.
On the Specific Heats of the Gases. By James Apjohn, M.D.

On the ruined Abbeys in the Province of Connaught By the Rev.
Cesar Otway.

On the Cross and Praia Ni 3 Con By Sir. William Pode
Address of the President. me tad sg

1838—1839.

On the Theory of the Ethers. By Robert J. Kane, M.D.

On the Laws of Crystalline Reflexion. By M. Neumann of Roniger
berg, with Remarks by James Mac Cullagh, LL.D.

Extract of a Letter from Professor Rafn of Copenhagen to George
Downes, Esq. .. - abet

On the Cydippe Pomiformis, a Notice of a Bolina, ‘owe on ‘he
Trish Coast. By Robert Patterson, Esq.

On the Longitude of the eee ee By ‘the ‘2
Thomas R. Robinson, D.D. . iy

On the Structure of ae Verse. By the rome William Benes,
D.D.

spare cs on vthe Dynamics of Light. By Sir William R. Hamilton,
TASS Se Hee 245,

Ona ae and Map of the County of Mey. By William Bald,
Esq., C.E. .

Notice of a Taraalue near Rush, County of Dublin. By Lieut
nant Newenham, R.N.. .

Notice of a singular A ppetenes of the oa biaceved on ‘the
16th December, 1838. By Sir William R. Hamilton, A.M. .

On the Remains of Oxen found in the oe of Ireland. a Robert
Ball, Esq. -

On a Substance eoneewaded with White Precipiat By Robert J.
Kane, M.D... .

Notice of the Aurora of ihe iat Tiel: 1686. ‘By the Rev. i.
Lloyd, Thomas Bergin, Esq., and James Apjohn, M.D. 254, 258,
Extracts of Letters from Professor Rafn to George Downes, Esq. .

On the Models of Achil and Clare Islands, and of the S. W. Dis-
trict of Mayo, &c. By William Bald, LOE ay oie

186
193
194

196
200
202
206

210
211
212

223
229
234
237
238
241
267
245
247
249
253
254

259
260

263

CONTENTS. vil

On the best relative Position of Three Magnets, in a Magnetical
Observatory. By the Rev. Humphrey Lloyd, A.M. . . page 264

On the Direction and Mode of Propagation of the Electric Force
traversing Media, which do not wnderg Electrolyzation. By
George James Knox, Esq. . . . 2) Ceulits Manges ole t4o

Letter from M. D’ Abbadie to the Rev. Beiter Lloyd. ... . 2(2
On two Gold Torques found at Tara. By Bisa Petrie, Esq. . 274

Address of the President. . . : . 276
On the eee of the Water of the Dead ae “By James 3s Apjohn,
BE Deh, 3 et tit (5 tag 287

On the Purple Dye of Fae By William R. Wylde, Esq. . . 293
On a Sepulchral Urn and Stone Coffin found in the Parish of Kil-

bride. By the Rev. Robert Walsh, LL.D. . . 296
On a Compound of Fluorine and Carbon. By George J. Knox
fo MA eee ee TE oe re 299

On the Property of the Light emitted by ee Coke to
blacken Photogenic Paper. By Robert Mallet, Esq... . . 300

Account for the Year ending the 3lst of March, 1839. . . . 302
Description of a Peruvian Mummy. By William R. Wylde, Esq. 305, 312

On a Manuscript Translation of Part of ew ea fineid. By
Joseph Lentaigne, Esq. . . BS 309

On Phosphorescence. By Sir Here Manele Bart. ere neue! = aces ai ohg:

On the original Language of the Pheenicians. BY William
O’Brien, Esq. . . 322

Account of the Cross of pole anid by Profane Mac Cullagh. 326
On the Action of Air and Water onIron. By Robert Mallet, Esq. 329
Account of the Magnetical Ohsenyatory of Dublin. By the Rev.

Humphrey Lloyd, eVien alors eee oe eet eh
On the Insulation of Fluorine, and on a Compound of Fluorine and
Selenium. By George J. Knox, Esq. . . . - . » 335

On the Employment of Rockets to determine the Difference of
Longitudes of Armagh and Dublin. By the Rey. Thomas R.
Robinson, D.D. . . ee 338

‘Researches respecting Vibration, pies Gh. he Theory of
Light. By Sir William R. Hamilton, AMM. .... . . 341

Address of the President. .. . : : 350
List of Subscribers for the Purchase of Gold discs erik at Tara 354

1839—1840.
Ou the Bolina Hibernica. By Robert Patterson, Esq. . . . 357
Notice of a Waterspout observed at Ruling, By the ae
Charles Dickinson, D.D. . . . 358
On 2 Loligo, found on the Shore of Dublin ee By) Fea ‘ Bal,
Esq. . . 362

On Rsnaghact Electricity. es E, s. Clarke, Te ak 364, 378

vill CONTENTS.

On the Irish Coins of Edward IV. By Aquilla Smith, M.D. page 367

Remarks on the Oxidating Power of Glass for Metals. By yee
J. Knox, Esq. 369

Notice of a Gaseous Coaneund of Fiuetine “and Cyanogen By

George J. Knox, Esq. . . . : 371
On the Dynamical Theory of Gacealine Retain ae Refraction.
By James Mac Cullagh, LL.D. . . . . . . . 374

Notice respecting Meteor-paper. By the Rey. amie Tiga A.M. 379
On Porcelain Seals found in Treland. By J. Huband Smith, Esq. . 380
On ancient Irish Seals. By George Petrie, Esq. . . . 382
On the Optical Laws of Quartz. By James Mac Cullagh, LL. D. . 385

An Inquiry into the Period of the first Use of the Zero. By
James O. Halliwell, Esq. . . - . . 386, 417

On the Querns used by the Irish. By J. “Huband inant Esq. . . 390

On the Magnetizing Power of the more refrangible Solar Bee *y
George J. Knox, Esq. and the Rev. Thomas Knox. . . . 393

Report of Council for the past Year. . . . 2 ang OOO
On a new Air Thermometer. By Wrigly Cee ee a) eee 405

On an essential Oil obtained during the Rectification of wae
By James Apjohn, M.D... ; 407

Account for the Year ending 31st ‘of Marchi, 1840, Pale gitar yh. eee I

Remarks on the Indications of the Barometer. ah the rece
of Dublins 5 se : 414

On the Boetian veer Notation. ey ie O. Halliwell, fag 415
On the Animal Remains and Antiquities found at Duns

By William R. Wylde, Esq... . . . . . 420
Remarks on Aristotle’s es of Aine: By Kedadaa
Osborne, M.D. . .. . 427

Notice of an African Gold Ring. By the ner: Jj ames s Todd, B. D. 430

On the Value of the Numerical Coefficient in the Formula for
the Force of Aqueous Vapour in the Atmosphere.* By James

Apjohn, M.D., and the Rev. Humphrey Lloyd, A.M. . . 433
On a Menisarint called the Book of Lismore. By the Rev. sane i
H. Todd, B.D. . ; . « 449, 458

Notes on the Aurora of the oth AGA 1840. ay J ae Ball, Esq.. 451

Notice of Meteor Paper found in Gloucestershire. By the Rev.
Thomas R. Robinson, D.D. . . . ; 454

On the comparative Amount of Rain at Tooaeaes cinty of Tip-
perary, and at Monks’ Eleigh, Suffolk. eh the Rey. Thomas
Knox, and Rey. Henry B. Knox. . . 455

Aecount of Observations of Magnetic Deluna Wada ie Prd
fessors Bache and Lloyd, with the View of determining Differences
of Longitude. By the Rev. Humphrey Lloyd, A. Me. 3c. yee

* The third of the tables of the elastic force of vapour, referred to in this
communication, pp. 443, 444, has been erroneously attributed to Mr. Lubbock.

CONTENTS. ix

On the Eee Power of the Gases. a Thomas Andrews,
M.D. page 465

On a new ibe Os fies Kilbricken Mine, County of Clare. By

James Apjohn, M. iPMAR Mah 469
On a Principle for pode an ever- -basning awe ‘By George

J. Knox, Hsq.. . © . 473
On Fluctuating Functions. By Sir William R, Hamilton, LL. D. . 475
On an Ancient Irish Bell. By George Petrie, Esq. . . . . . 477

OBJECTS EXHIBITED,—pp. 7, 8, 19, 25, 32, 212, 235, 271, 276, 292, 293,
294, 393, 457.

ResoLutions,—pp. 13, 60, 93, 101, 104, 135, 150, 161, 167, 244, 261,
271, 292, 294, 326, 339, 426.

ELEcTIons oF CounciL,—pp. 42, 142, 285, 402.

Exection oF Memsers,—pp. l, 8, 19, 33, 51, 61, 71, 73, 88, 105, 132,
151, 169, 193, 223, 237, 247, 262, 293, 305, 317, 325, 357, 385, 390,
405, 427, 451.

Donations,—pp. 7, 14, 19, 30, 36, 41, 47, 60, 70, 72, 80, 88, 91, 102,
105, 106, 131, 133, 144, 150, 161, 168, 175, 190, 205, 221, 225, 235, 237,
245, 250, 262, 263, 271, 293, 295, 311, °325, 354, 359, 362, 387, 389, 395,
403, 412, 450, 457, 458, 477.

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PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1836—1837. No. 1.

October 24, 1836.

Rev. B. LLOYD, D.D., Provost, T. C.D., President,
in the Chair.

Rev. Edward Marks, Frederick Darley, Esq. » Rev. John
A. Bolster, and Rev. James S. Reid, D.D., were elected
Members of the Academy.

A paper was read, entitled “ Contributions to the History
of Pyroxylic Spirit, and the derived Combinations.” By
Robert J. Kane, M.D. M.R.I.A., Professor of Natural
Philosophy in the Royal Dublin Society.

In this paper Professor Kane stated that he had re-
peated the analysis of pyroxylic spirit and of methylic ether,
and found the composition given by Dumas for these bodies
to be perfectly correct. He likewise re-examined the py-
roxylic spirit, described and analysed by Liebig, having been
presented with a specimen of the original spirit for that pur-
pose by Professor Liebig. The result of his experiments is,
that the pyroxylic spirit of Liebig is quite distinct from that
of Dumas; and that both of these chemists were right in
the analyses which they published.

By treating the pyroxylic spirit of Dumas (methylic alco-
hol) with peroxide of manganese and sulphuric acid, there is
obtained a light colourless liquor boiling at 103° Fahrenheit.

B

2

It is composed of c,H,,0,. It may be considered as tritoxide

of ethyl AE.o. or as corresponding in the methylene series
to the acetal in the alcoholic, being a tribasic formome-
thylic ether; thus,

3Xc,H,O=C,H,,0, three atoms methylic ether.

C,H, 0, one atom formic acid.

- Oo—
C,H, 0; 2=C) Ho;

the density of its vapour is 2,45.

The pyroxylic spirit of Liebig, c,u,,0,, is considered by
Professor Kane to be not a deutoxide of ethyl, but a tri-
basic ether, containing the methylene aldehyd. Thus,

3 XC,H,O=C,H,,0, three atoms methylic ether.

c,H, 0 methylic aldehydene.

C,H, 0, 2—C, Hy, 0,

The analysis of the heavy oily liquor obtained by the ac-
tion of chlorine on methylic alcohol, as pointed out by Du-
mas, is given by Professor Kane as leading to the formula

c,cl,u,0,. The products of its decomposition by ,bases will

form part of a subsequent paper.
An oil which accompanies pyroxylic spirit gave for its
composition C,,H,, 0. isomeric with the resinain of Fremy.
Professor Kane has found pyroxylic spirit to form a
compound with chloride of calcium crystallizing in plates,
(hexagonal,) consisting of one atom of chloride of calcium
with two of the pyroxylic spirit.

A paper was also read, “‘ On the laws of Reflexion from
Metals.” By James Mac Cullagh, M.R.I. A., Professor of
Mathematics in the University of Dublin.

The author observes that the theory of the action of me-
tals upon light is among the desiderata of physical optics,
whatever information we possess upon this subject being

3

derived from the experiments of Sir David Brewster. But,
in the absence of a real theory, it is important that we
should be able to represent the phenomena by means of em-
pirical formule ; and, accordingly, the author has endea-
voured to obtain such formule by a method analogous to
that which Fresnel employed in the case of total reflexion
at the surface of a rarer medium, and which, as is well
known, depends on a peculiar interpretation of the sign

—1. For the case of metallic reflexion, the author as-
sumes that the velocity of propagation in the metal, or the
reciprocal of the refractive index, is of the form
m(cos x + V7 —1sin x)3

without attaching to this form any physical signification,
but using it rather as a means of introducing two constants
(for there must be two constants, m and x, for each metal)
into Fresnel’s formulee for ordinary reflexion, which contain
only one constant, namely, the refractive index.

Then if ¢ be the angle of incidence on the metal, and 2’ the
angle of refraction, we have

sind’ = m(cosy + ¥ —Isin x) sinz, (1)

and therefore we may put

cosi/= m' (cos x’— ¥ — Isiny’) cosi, (2)

if m!* cos ‘t= 1—2m cos2y sin + m'‘sin “2, (3)
2ein Qy sin 2s

and tan2y/= (4)

1—m?cos 2x sin"
Now, first, if the incident light be polarized in the plane
of reflexion, and if the preceding values of sin7’, cos 2’, be
substituted in Fresnel’s expression
sin (¢—2’)
sin (¢-+7’)’
for the amplitude of the reflected vibration, the result may
be reduced to the form tl
a(coso— y¥ —I1 sino), (5)
B2

4

if we put
m
tanyp =o (6)
tand=tan2psin(x +x) (7)
ge 1—sin 2) cos(x +x’) (8)

—~ T+sin 2Wcos(x +x’)

Then according to the interpretation, before alluded to,
of / —1, the angle 8 will denote the change of phase, or
the retardation of the reflected light; and a will be the
amplitude of the reflected vibration, that of the incident vi-
bration being unity. The values of m’,y’, for any angle of
incidence, are found by formule (3), (4), the quantities m, y,
being given for each metal. The angle y’ is very small, and
may in general be neglected.

Secondly, when the incident light is polarized perpendi-
cularly to the plane of reflexion, the expression

tan (¢—7?’)
tan (2 +4’)
treated in the same manner, will become
a’ (cos8’—~ ¥ — 1sind’), (9)
if we make
tanW’=mm’, (10)
tand’ =tan2y’'sin(x— x’), (11)
na 1—sin2y’ oN (12)

1+sin2y’cos(y—x’)’
and here, as before, 0’ will be the retardation of the reflected
light, and a’ the amplitude of its vibration.

The number Maa may be called the modulus, and the

angle yx the characteristic of the metal. The modulus is
something less than the tangent of the angle which Sir David
Brewster has called the maximum polarizing angle. After
two reflexions at this angle a ray originally polarized in a

5

plane inclined 45° to that of reflexion will again be plane
polarized in a plane inclined at a certain angle ¢ (which is
17° for steel) to the plane of reflexion; and we must have
nr
a

ial SS (13)
Also, at the maximum polarizing angle we must have

o’—d= 90°. (14)
And these two conditions will enable us to determine the
constants m and x for any metal, when we know its maximum
polarizing angle and the value of ¢; both of which have been
found for a great number of metals by Sir David Brewster.
The following table is computed for steel, taking m = 33,
y= 54¢,

e+e?

0°) 27°] 27° | .526 | .526 | .526
30 | 25] 31 575 | .475 | .525
45} 19} 38 638 | 407 | .522
60} 13] 54 129 | 208; .5 8
75 | 7 {| 98° | 850] .240 | .545
85 | 24 152 nT AGlap tho
+1 aie a al il i

The most remarkable thing in this table is the last
column, which gives the intensity of the light reflected when
common light is incident. The intensity decreases very
slowly up to a large angle of incidence, (less than 75°,) and
then increases up to 90°, where there is total reflexion. This
singular fact, that the intensity decreases with the obliquity
of incidence, was discovered by Mr. Potter, whose experi-
ments extend as far as an incidence of 70°. Whether the
subsequent increase which appears from the table indicates a
real phenomenon, or arises from an error in the empirical for-_ .
mulz, cannot be determined without more experiments. It
should be observed, however, that in these very oblique inci-
dences Fresnel’s formulz for transparent media do not repre-
sent the actual phenomena for such media, a great quantity

6

of the light being stopped, when the formule give a reflexion
very nearly total.

The value of 8’—6, or the difference of phase, increases
from 0° to 180°. Whena plane-polarized ray is twice reflected
from a metal, it will still be plane-polarized if the sum of the
values of &—8 for the two angles of incidence be equal
to 180°.

It appears from the formule that when the character-
istic y is very small, the value of 8’ will continue very small
up to the neighbourhood of the polarizing angle. It will
pass through 90°, when mm’=1 ; after which the change will
be very rapid, and the value of 8” will soon rise to nearly 180°.
This is exactly the phenomenon which Mr. Airy observed
in the diamond.

Another set of phenomena to which the author has ap-
plied his formule are those of the coloured rings formed be-
tween a glass lens and a metallic reflector; and he has thus
been enabled to account for the singular appearances de-
scribed by M. Arago in the Memoires d Arcueil, tom. 3,
particularly the succession of changes which are observed
when common light is incident, the intrusion of a new ring,
&c. But there is one curious appearance which he does not
find described by any former author. Itis this. Through
the last twenty or thirty degrees of incidence the first dark
ring, surrounding the central spot which is comparatively
bright, remains constantly of the same magnitude; although
the other rings, like Newton's rings formed between two gJass
lenses, dilate greatly with the obliquity of incidence. This
appearance was observed at the same time by Professor
Lloyd. The explanation is easy. It depends simply on this
circumstance, (which is evident from the table,) that the angle
180°—6é’, at these oblique incidences, is nearly proportional
to Cos 2.

As to the index of refraction in metals, the author con-

jectures that it is equal to

7

Rev. Robert Gage exhibited specimens of Coal and
Iron stone, recently found in Rathlin Island, on the North
coast of Ireland.

DONATIONS.

Archeologia ; or Miscellaneous Tracts relating to An-
tiquity, vol. xxvi. Presented by the President and Council
of the Society of Antiquarians of London.

Copy of the Ordnance Survey of the County of Louth,
in 27 sheets, presented by Lieut. Colonel Colby, R. E.

Philosophical Transactions of the Royal Society of Lon-
don, for the years 1834, Part 2; 1835, Parts 1 and 2; and
1836, Part 1. Presented by the Society.

List of the Fellows of the Royal Society. By the same.

Memoir of the Fresh-water Limestone of Burdiehouse, in
the neighbourhood of Edinburgh. By Samuel Hibbert, M. D.,
F.R.S.E. Also, Analysis of Coprolites, and other Organic
Remains, imbedded in the Limestone of Burdiehouse. By
Arthur Connell, Esq., F. R.S.E. Presented by Doctor
Hibbert.

History of the Extinct Volcanos of the Basin of Neuweid,
on the lower Rhine. By Samuel Hibbert, M.D., F.R.S. E.
Presented by the Author.

Memoir on the Theory of Partial Functions. By John
Walsh. Presented by the Author.

An Essay on the Origin and Nature of Tuberculous and
Cancerous Diseases. By Richard Carmichael, M.D.,M.R.LA.
Presented by the Author.

Transactions of the American Philosophical Society.
Vol. v. Part 2. (New Series.) Presented by the Society.

Transactions of the Geological Society of London. Vol.
iii. Part 3. (Second Series.) Presented by the Society.

.

$

November 30. (Stated Meeting.)

Rev. B. LLOYD, D.D., Provost, T.C. D., President,
in the Chair.

William E. Bolton, Esq. and Thomas F. Bergin, Esq.
were elected Members of the Academy.

Sir William Betham exhibited to the Academy a specimen
of the ancient brazen ring money, found in the county of
Monaghan,* and also a piece of cast iron, found with many
others, in boxes, on board a vessel wrecked on the coast of
Cork last summer. This vessel was bound to Africa, where
it is stated the pieces in question pass for money. ‘They
are so similar in shape and size to the ancient specimens,
that there can be no reasonable doubt of the identity of
their uses; and thus the theory advanced in the paper re-
ferred to is strongly confirmed.

Sir William Betham also read an extract of a letter from
a friend, in which it was stated, that gold rings, exactly”
formed like those found in the Irish bogs,—that is, of gold
wire turned into the form of rings, but not united at the
ends;—pass current at this moment as money in Nubia and
Sennaar.

The Dean of St. Patrick’s exhibited two bronze spe-
cimens of the first mentioned articles found in Italy, one of
which was encrusted with crystals of carbonate of lime.

The following papers were read :

1. On the Affinity of the Hiberno-Celtic and Phe-
nician Languages.” By Sir William Betham, M.R.I. A.,
Secretary of Foreign Correspondence.

In this paper the author undertakes to prove that the
names of the divinities, heroes, and nymphs of the Greeks
and Romans, are significant in the Hiberno-Celtic language ;

* See paper read 23rd May and 27th June, page 12.

9

that many of the ancient names of countries, seas, and places
are also significant; and that the same thing is true of the
names of the Etruscans and Pelasgi, as well as of the words of
both these people which have come down to us in the Greek
and Roman writers. From this he infers that the Pelasgi, the
Etruscans, and the Celts were all colonies of the Phoenician
people, and all spoke the language now called Gaelic or
Hiberno-Celtic. He instanced the remarkable fact men-
tioned by Suetonius in his Life of Augustus Cesar, (c. 97,)
where, giving an account of the death of Augustus, and the
omens which preceded it, he says:

‘* Sub idem tempus ictu fulminis ex inscriptione statuze
ejus prima nonninis litera effluxit. Responsum est centum solos
dies posthac victurum, quem numerum C litera notaret; fu-
turumque ut inter deos referretur, quod ASSAR, id est
reliqua pars e Casaris nomine, Etrusca lingua Deus voca-
retur.”

Moy ay is one of the Irish names for God, and not only is
the word itself to be found in the Irish dictionaries and
MSS. but it is compounded of two Irish words meaning the
eternal ruler, or ruler of ages: 007, ages—ayp, ruler.

The author gave many examples of the significance of the
names of the Greek and Roman divinities, and also of the
ancient names of countries, in the Hiberno-Celtic language ;
among them the following :

Aurora—the golden hour, or sunrise.

Bacchus—the lame drunkard.

Diana—the goddess.

Gorgones—the frightful women.

Haruspex—judging from a pang or throe.

fris—the sun and the shower.

Neptune—the king of the waves.

The names of the Nereides denote the flitting aerial
nymphs; the nymph of the sea weed; the silent nymph;
the spark of the wave; the nymph of the deep water, the

~ 10

rock, the estuary, the storm, &c. &c. The word nymph
also means the holy one, or one set apart.

Pluto—the miner, or one who lives in a cave.

Sesostris—the name applied to Rameses the Great by the
Greeks,—implies the fortunate, scientific, and powerful
prince.

Silenus—the staggering drunkard.

Venus—the woman of the community; the courtesan.

Of the names of countries :—

Abyssinia—the country of rain.

Ethiopia—the country of springs or wells.

Assyria—the old country of power.

Egypt—the cultivated valley.

The Euxine—the little sea.

The Adriatic—the sea of enchantment, &c. &c. &c.

The author affirmed that examples of this kind were so
numerous and so striking, that it was impossible to ascribe
them to accidental coincidence; and he inferred from all, that
these names were given by the Pheenicians, and that the
Hiberno-Celtic was the language spoken by that people.

2. “On the Propagation of Light in Uncrystallized
Media.” By the Rev. H. Lloyd, F.R.S., M. R.I.A., Pro-
fessor of Natural Philosophy in the University of Dublin.

The objects of the author have been—1. to simplify and
to develop that part of M. Cauchy’s theory, which relates
to the propagation of light in an ethereal medium of uni-
form density; 2. to extend the same theory to the case
of the ether enclosed in uncrystallized substances, taking
into account the action of the material molecules.

_ Some of the simplifications adopted in the first part of
these inquiries suggest themselves naturally. Thus the axes
of symmetry of the medium are taken as the axes of coordi-
nates, and the direction of propagation is assumed to coin-
cide with one of these axes. By these suppositions the

11

differential equations of motion are reduced to a very simple
form; and it is manifest that the assumptions themselves
involve no real limitation of the problem. The well known
expressions for the component displacements are deduced
by the integration of these equations. The following is that
in the direction of the axis of a:

E=acos(ut—kz+a) ;
in which
oar
se:
7 being the period of vibration, and X the length of the wave.

These quantities are connected by a relation given by the
method of integration.

Qa
VES,
=

The preceding formula, however, is not the most general
form of the expression for the displacement. It is found
that in certain cases the integral becomes

E=ae—™ cos (ut—gz+a).

From this expression it follows that the amplitude of the
displacement, and therefore the intensity of the light, de-
creases in geometrical progression, as the distance in-
creases in arithmetical progression ; and as the constant / is
in general a function of w, or of the colour, the differently
coloured rays will be differently absorbed. The complete
value of & being the sum of a series of terms similar to the
preceding, it is manifest that we have here a satisfactory ac-
count of the apparently irregular distribution of light in the
absorbed spectrum. To explain the absolute deficiency of
the light at certain points, it is only necessary to admit that
the function / varies in certain cases rapidly with moderate
changes in w, and becomes very great for certain definite
values of that quantity. '

The preceding integral has been already obtained by
M. Cauchy, in a valuable memoir recently printed in litho-
graph. The method employed by the author seems, how-

12

wo

ever, to be fundamentally different from that of M. Cauchy ;
and in fact he was led to this form of the integral by other
considerations before he was aware that he had been pre-
ceded in the deduction.

The remainder of the present communication is taken up
with the discussion of the relation between the coefficients
wand *&, which expresses the law of dispersion. Following
M. Cauchy,* the author has transformed this relation by
converting the triple sums into triple integrals; and he has
found that, by applying this transformation at an earlier
stage of the investigation, the resulting relation is deduced
with great simplicity.

The relation between uz and &, for the vibrations in the
plane of the wave, has already yielded to M. Cauchy the
probable result, that the molecules of the ether repel one
another according to the inverse fourth power of the distance.
When this law of force is substituted in the corresponding
relation for the zormal vibration, the author finds that the
u
k
finite ; so that the normal disturbance is propagated énstan-
taneously, and gives rise to no wave. Thus the hypothesis
of transversal vibrations seems to be established on theore-
tical grounds.

The author finally gives reasons for concluding that the
theory, in its present form, is insufficient to explain the phe~
nomena of light in bodies ; and that it becomes necessary in
this case to take into account the action of the material
molecules. This extension of the theory will be given in
a future communication.

resulting value of —, or of the velocity of propagation, is in-

3. “On the Composition of Thebaine.” By Robert J.
Kane, M. D., M.R.I.A., Professor of Natural Philosophy
in the Royal Dublin Society.

* Nouveaux Exercices de Mathematiques. Livraison 7™°.

13

The author gave an account of the analysis of the vege-
table alcaloid thebaine (paramorphine) which had been dis-
covered in opium, and of which the analysis by Pelletier and
Couerbe gave discordant results. With a specimen which
had been prepared by Apothecary Merck of Darmstadt,
Dr. Kane obtained the formula C,, N, H,, O,, (Berzelian
atoms,) and giving the per cent. composition:

25 Carbon <= 74,57.= 1910,925
2 Azote = 6,89 — 177,056
28 Hydrogen= 6,83 — 174,714
3 Oxygen = 11,71 — 300,000

100,00 2562,675

Owing to the circumstance of the salts of this base with the
mineral acids being uncrystallizable, the atomic weight ob-
tained by analysis could not be synthetically confirmed.

Professor Kane read likewise an extract of a letter from
Professor Liebig, of Giessen, communicating some new re-
sults of chemical analysis.

It was resolved, on the recommendation of council, that
the bye-laws relating to the meetings of the Academy and
Council (Chap. IV. Sects. 2 and 6), be altered, and the fol-
lowing substituted :—

(2.) “That a General Meeting of the Academy shall
likewise be held on the second Monday of November and
December, and on the second and fourth Mondays of Ja-
nuary, February, April, May, and June, at 8, p.m. At
these Meetings, such communications as shall have been
approved of by the Committees during the preceding part of
the month, shall be read.”

(6.) “That the Stated Meetings of the Council shall be
held on the first and third Monday of every month, from
November to June, inclusive ; with power to adjourn, from
time to time, at all times of the year. Five to be a quorum.”

14

It was further resolved, on the recommendation of
Council, that the “ Proceedings of the Royal Irish Academy,”
be printed every month during its sittings, for the use of its
members.

** The Proceedings” to be under the management of the
Council, and to contain— =

F Abstracts of the larger papers read to the Academy.

. Minor communications, not intended for the Trans-
bia printed more at length.

3. Notices of the election of Members, of presents re-
ceived, and of all other matters of general interest transacted
at the Meetings of the Academy.

DONATIONS.

A copy of the Ordnance Survey of the County of Done-
gal, in 112 sheets. Presented by Lieut. Colonel Colby.

Flora Batava, No. 107. By H.C. Van Hall. - Pre-
sented by the Author.

Estatutos da Academia Real das Sciencias de Lisboa.
Presented by the Society.

Der erste Unterricht des Taubstummen. Von M. C. G.
Reich. Presented by Henry Holmes Joy, Esq.

Bliche auf die Taubstummenbildung. Von M. C. G.
Reich. Presented by the same.

Astronomical Observations made at the Observatory of
Cambridge, for the year 1835. By George Biddell Airy,
Esq., Astronomer Royal. Presented by the Author.

Stax lectures on the Wave-theory of Light. By the Rev.
H. Lloyd, F.R.S.,&c. Presented by the Author.

Reports of the Committee of the Franklin Institute on the
Explosions of Steam Boilers: in two parts. Presented by
the Franklin Institute of Pennsylvania.

Report of the Managers of the Franklin Institute, in re-
lation to Weights and Measures. Presented by the same.

15

Observations to determine the Magnetic Dip at Baltimore,
Philadelphia, New York, West Point, Providence, Spring-
field, and Albany.’ By A.D. Bache, Professor of Natural
Philosophy and Chemistry, and Edward H. Courtenay, Pro-
fessor of Mathematics, in the University of Pennsylvania.
Presented by the former.

On the relative horizontal Intensities of terrestrial Mag-
netism at several Places in the United States. By the same.

Analysis of some of the Coals of Pennsylvania. By H. D.
Rogers, F. G.S. London, and Professor Bache, &c. Pre-
sented by the latter.

Notes and Diagrams, illustrative of the Directions of the
Forces acting at and near the Surface of the Earth, in diffe-
rent Parts of the Brunswick Tornado of June 19th, 1835.
By A.D. Bache, Professor of Natural Philosophy and Che-
mistry in the University of Pennsylvania.

The same author presented also the following papers to
the Academy:

Remarks on a Method, proposed by Doctor Thomson, for
determining the Proportions of Potassa and Sodain a mixture
of the two Alkalies.

Note relating to the hardening of Lime under Water, by
the Action of Carbonate of Potassa, &c.

On the comparative Corrosion of Iron, Copper, Zinc, §c.
by a saturated Solution of common Salt.

Memoir on the Elastic Force of the Vapour of Mercury at
different Temperatures. By M.Avogadro. (Translated by
Prof. Bache.)

An Essay on Chemical Nomenclature. By J. J. Berzelius.
(Translated from the French, with Notes, by Prof. Bache.)

EMistorical Notes.

Note of the Effect upon the Magnetic Needle of the Aurora
Borealis, visible at Philadelphia on the 17th of May, 1833.

Diagrams for illustrating a Register of the Direction of
the Wind.

16

Experimental Illustrations of the radiating and absorbing
Powers of Surfaces for Heat, &c.

Replies to a Circular in relation to the Occurrence of an
unusual Meteoric Display on the 13th of November, 1834.

Notice of Experiments on Electricity developed by Mag-
netism.

Experiments on the Efficacy of Perkins’s Steam Boilers,
or Circulators.

On the alleged Influence of Colour on the Radiation of
non-luminous Heat.

Safety Apparatus for Steam Boilers.

Observations on the Disturbance in the Direction of the
horizontal Needle during the Aurora of July 10th, 1833.

Report of Experiments on the Navigation of the Chesa-
peake and Delaware Canal by Steam.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.
1836—1837. | No. 2.

December 12.

RICHARD GRIFFITH, Esgq., ‘in the Chair.

A paper was read “On the Seals of Ireland, (Phocide.)”
By Robert Ball, Esq., M.R. 1. A.

The author stated the circumstances by which he was
led to discover that the seal of most frequent occurrence on
the Irish coast was not defined as a British species, together
with the subsequent identification of that animal, by Profes-
sor Nilsson, as the Halichzrus Griseus of his Scandinavian
Fauna, (Phoca Gryphus of Fabricius,) found in the Baltic
and North Sea. He asserted, however, that the habits of
the Halichzrus of this country differed so much from those
ascribed to it in the Baltic, that it appeared to him not un-
likely, on comparison, to prove a distinct species. He showed ’
that the colour of the animal kere varied so much from sex,
age, season, &c. that it could not be considered of any value
as a character of species in the present state of our know-
ledge of the subject. He alluded to the very small size of
the brain compared with that of the genus Phoca, and stated
that the intellectual powers bore the same proportion. Mr.
Ball then proceeded to show that the simple form of the
teeth of Halicherus (approaching closely to those of some
species of Delphinus) furnished sufficient grounds for sepa-
rating it from the genus Phoca ; and observed, that the Hali-

c

18

cherus may always be distinguished from other seals, by
its straight profile, fierce aspect, and greater proportionate
length. He mentioned the fact of his having discovered that
the specimen in the British Museum, solong known as Dono-
van’s Phoca Barbata, (and the long-bodied seal of Parsons,) is
formed of the skin of a Halichzrus improperly stuffed; and
he noticed the mistakes to which this has given origin.

Mr. Ball next gave instances of the occurrence in this
country of the Phoca Vitulina, (P. vartegata Nils.) which he
considered identical with the seal stated by Sir E. Home
(Phil. Trans. 1822) to have been killed in the Orkneys,
though it appears from the cranium figured as if a few teeth
of the P. Groenlandica were inserted into the upper jaw.
The author related some anecdotes of the interesting and
beautiful specimen now in the Zoological Gardens; con-
trasted the species in structure and habits with the Haliche-
rus; and expressed his dissent from the statement put for-
ward in Mr. Bell’s British Quadrupeds, on the authority of
Professor Nilsson, that the oblique position of the molar teeth
in P. Vitulina was a specific character of unerring value. He
has shown, in fact, that the obliquity in question arose from
the insufficient development of the jaws in early life, which
contracted the space for the teeth; and that it disappeared
long before the skull reached its maximum size, and par-
tially occurred in the young Halicherus.

Mr. Ball then alluded to the seal taken in the Severn,
which Professor Nilsson pronounced to be his Phoca Annel-
lata; but which has since been stated, with the Professor’s
concurrence, to be the P. Groenlandica. He expressed
his doubts.as to the justness of this conclusion, observing
that the Groenlandica was a large species, while the Severn
seal was certainly a small one. He further showed that the
form of the inter-maxillary bones, where they joined the
nasal, was quite sufficient to distinguish it from the specimen
figured by Sir E. Home, in the paper before referred to; and

19

he expressed his belief that the species was still to be de-
termined.

The author concluded by stating his belief in the ex-
istence of a fourth seal (probably P. Barbata) on the
southern coasts of Ireland, which he had occasionally seen,
but never had opportunity of closely inspecting ; and finally
exhibited a number of sketches illustrative of his paper,
showing generic and specific distinctions of external forms,
skulls, teeth, czeca, and of the great sinuses of the hepatic
veins.

Professor Kane laid before the Academy, specimens of the
salts of a new acid, called by him “ Xanthomethilic Acid.”

The same gentleman stated some conclusions to which
he had recently arrived, from the examination of pyroacetic
spirit, which he considered to be a new alcohol.

DONATIONS.

Discours sur quelques Progrés des Sciences Mathematiques
en France, depuis 1830. Par le Baron Charles Dupin,
President de Académie. Presented by the Author.

Researches on Heat. (Second Series.) By James D.
Forbes, Esq. F.R.SS.L.& E., F.G.S. Presented by the
Author.

January 9, 1837.

Rev. B. LLOYD, D. D., Provost, T.C.D., President,
in the Chair.

Matthew Barrington. Esq., Arthur E. Gayer, Esq., Sir
John Kingston James, Bart., Francis Barker, M.D., Wil-
liam Gregory M. D., F.R.S.E., Edward A. Clarke, Esq.,
Charles Lambert, Esq., and Thomas Williams, Esq., were
elected Members of the Academy.

c 2

20

The Secretary read a letter from the Secretary of the
Royal Academy of Madrid, returning thanks for a copy of

the Transactions.

Sir William Betham read a letter from the Baron de
Donop, of Saxe Meiningen, on the subject of the alleged
discovery of the MS. Translation of Sanconiathon’s His-
tory of the Pheenicians, by Philo Biblius.*

Sir William Betham read a letter from Sir John Tobin
of Liverpool, respecting the cast-iron ring money, found on
board the wreck of a vessel, and exhibited at the meeting of
the Academy in November :—the following is an extract.

“On the subject of the schooner, Magnificent, which
was lost somewhere near Cork, some time since:—she was
bound to the river Bonney, or New Calabar, which is not
far from the kingdom of Benin. The trade to these rivers
for palm oil and ivory, is cotton goods, gunpowder, muskets,
and a great variety of other articles ;—and among them ma-
nillas, both of iron and a mixed metal of copper and brass,
which is the money that the people of Eboe and Brass Coun-
try, and all the nations in that neighbourhood, go to market
with. On Wednesday next I will send you a manilla of
each kind.”

Sir John Tobin states the price of the copper manillas to
be £105 per ton, and that of the cast iron £22 ; the former
passes, therefore, for about five of the latter. They so per-
fectly resemble the Irish antique, as to be scarcely distin-
guishable except by the difference of the material.

Sir William Betham also read a letter from Captain Ed-
ward Jones to Samuel Hibbert, M.D., which the latter
gentleman transmitted to him, with the sketches there al-
luded to.

* An extract from this letter will be given in the next number of the Proceedings.

ah

a

‘The annexed two sketches are taken from a cast of the
species of money now at the present day passing current
among the Africans. It so strongly resembles what we saw
in Ireland, that I thought you might be interested in a copy
of it. Mr. Dyson, who was for some years a surgeon on
board an African merchantman, brought it with him; and
the first opportunity, I shall make inquiries respecting this ~
and other coin used among the natives. I am told that in
the country they are made of solid gold, as in Ireland.”

Sir William Betham also read an extract from a letter
from Mr. Bonomi to T. C. Croker, Esq.

‘You ask me for a note on the ring money of Africa;
here it is. So little has the interior of the country changed
in that particular since the days of the Pharaohs, that
to this day, among the inhabitants of Sennaar, pieces of
gold in the form of a ring pass current as money. The
rings have a cut in them for the convenience of keeping them
together ; the gold being so pure you easily bend them, and
unite them in the manner ofachain. This money is weighed
as in the days of Joseph.”

These gold rings are so similar in shape to the ancient
rings found in Ireland, that the sketch of one accurately
represents the other.

It is a remarkable fact that the name manzlla, which
these brass and iron articles still bear in Africa, signifies
money in the Celto-Pheenician Irish. Main is ‘ value,’ ‘ worth,’
and aillech is ‘ cattle,’ ‘ household stuff,’ or ‘ any kind of pro-
perty.’ So that in this respect the derivation is similar to
that of pecunia from pecus. The manillas were, no doubt,
introduced into Africa by the same people that brought
them to Ireland; and as the Negro nations have changed
but little, if at all, they still pass as money by their old Phe-
nician name.

22

The Rev. James H. Todd, A. M., M.R.1. A., Fellow of
Trinity College, gave an account of a discovery made by
Mr. John O'Donovan, of a valuable though imperfect copy,
in MS., of the Annals of Kilronan, or Book of the O’Duige-
nans, a work that had hitherto been supposed to be lost.

This MS. was discovered by Mr. O'Donovan while en-
gaged in preparing a catalogue of the Irish MSS. preserved
in the University Library.

The volume is in quarto and, in its original state, con-
sisted entirely of parchment. It is now imperfect both at
the beginning and at the end, and has also some interme-
diate chasms. The first and earliest portion appears to have
been transcribed by one Philip Badley, who states himself
to have been engaged in the task in the year 1580; but two
or three other hands, evidently of the same period, may be
observed throughout the volume, as if two or more scribes
had been simultaneously engaged in its transcription.

The Chronicle in its present state begins with the year
1014 and ends with 1571. The principal chasms are be-
tween the years 1138 and 1170, and also between the years
1316 and 1462. In the former of these chasms, several
leaves of paper have been inserted which are entirely blank.
The latter has also been filled with paper, on which some
very brief entries have been made relating to the years be-
tween 1412 and 1462. Many of these entries, however, re-
cord merely the date, with the lunar and solar cycles, indic-
tion, and Julian period corresponding. ‘Two copies of this
paper portion of the volume are preserved, one of them of a
date perhaps a century later than the other. The older ap-
pears to have been written in the sixteenth, or early in the
seventeenth, century.

Throughout the book several marginal notes occur,
which are for the most part summaries of the text, both
in Irish and English. The greater part of the English
notes are in the hand-writing of Roderick O'Flaherty, the

23

celebrated author of Ogygia. ‘This fact was ascertained
by comparing these entries with the known autograph of
O'Flaherty. The volume, therefore, was formerly in the
possession of that eminent antiquary.

The book is lettered on the back 7?gernachi continuator ;
and has hence been erroneously supposed to be the con-
tinuation of Tigernach’s Annals, drawn up by Augustin Mac
Raith, (Magrath), called by Colgan and others Mac Raidinus,
a canon of the Augustinian monastery of All Saints in Lough
Righ, in the River Shannon, who died A. D. 1405. And as
this chronicle extends to the year 1571, Mr. O’Reilly sup-
posed it to include a continuation of Magrath’s work.* This
error, which the slightest inspection of its contents refutes,
was afterwards pointed out by Mr. O’Reilly himself ;+ and the
comparison of the book with a complete copy of the continua-
tion of Tigernach in the University Library, sets the question
entirely at rest.

Mr. O'Reilly having satisfied himself that this chronicle
was not what it had hitherto been taken for, declares him-
self unable to say what it should be called; but Mr. O’Dono-
van has now proved it to be the ANNaALs or KILRONAN, or
Boox or THE O’DuicENnans, mentioned by the Four Masters
as one of the original sources from which they derived the
materials of their celebrated work.

Mr. Todd then stated that extracts from what is called
the Book of Kilronan, in the hand-writing of Charles O’Conor
of Belanagare, are preserved in the Stowe Library; and that
a quotation from these extracts given by Dr. O’Conor in his
catalogue of the Stowe MSS., was not to be found in the
Dublin MS. of the Kilronan Annals. This fact appeared
at first sight to create a formidable difficulty in the way of

* Transactions of the Hiberno-Celtic Society, in ann. 1405, p. exiii.
f See Mr. Mason’s Catalogue of the Irish MSS. in Trinity College.

24

Mr. O’Donovan’s opinion. The consideration of it, however,
led Mr. Todd to conjecture, that the Book of Kilronan, from
which Charles O’Conor made the extracts in question, could
not be the Annals of Kilronan, which were in the hands of
the Four Masters. Mr. O’Conor describes it as the book of
the church of Kilronan, and from the extracts he has made
from it, it appears to have begun at least with the times of St.
Patrick, whereas the Annals of Kilronan, as described by the
Four Masters, began with the year 900, and are expressly
called by them the Book of the O’Duigenans. The one, there-
fore, was a church book, or chronicle kept by the ecclesiastics
connected with the church of Kilronan, whereas the other was
the family chronicle of the Mac Dermots, compiled by their
family bards, the O’Duigenans, of Kilronan. This conclu-
sion is interesting, as acquainting us with the fact, that the
Book of the Church of Kilronan existed so lately as the year
1728, when O’Conor made the extract from it, which is now
in the Stowe Library, and that it may perhaps exist to this
day unknown, or under some other name.

The discovery of the Book of the O’Duigenans, or An-
nals of Kilronan, will be of great importance, if ever the
liberality of government, or the contributions of individuals,
should supply the means of printing the ancient historical
records of this country. 'Toacomplete edition ofthe Annals
of the Four Masters, it is essential that as many as possible
of the original documents from which they drew their ma-
terials should be in our hands. And this discovery supplies
us with one of these documents, whose existence was hitherto
unknown to Irish antiquarians. Of the ancient annalists,
whose works formed the basis of the Annals of the Four
Masters, there are now not more than two or three that are
not to be found in the Library of the Academy, or in that of

Trinity College.

29

_ Mr. Petrie exhibited a MS. of the four Gospels, in Latin,
of which he had given an account in a paper read some time
since before the Academy. This manuscript is said to have
been that given by St. Patrick to the first Bishop of Clogher.
It is enclosed in a brazen case, of very curious workmanship,
on which the circumstances connected with the gift are re-
presented in highly raised figures.

Professor Lloyd communicated to the Academy the con-
tinuation of his investigations “ On the Propagation of Light
in uncrystallized Media.”

In the first part of this paper, read on a former evening,
the author had expressed his conviction that the problem of
wave-propagation in bodies was incompletely solved, unless
the action of the material molecules be taken into account.
This he has attempted to do in the present continuation,
confining himself to the comparatively simple case in which
the molecules of the ether and of the body are uniformly
diffused.

The differential equations of motion inferred from these
considerations contain, each, the displacements of the mole-
cules of the ether and of the body,—with coefficients depending
on the masses and distances of the molecules, the law of force
to which they are subjected, and the length of the wave.
By a particular method of elimination, these pairs of simul-
taneous equations may be reduced each to a single one, of
the simple form which occurs in the case of a single vibrating
‘medium, the new coefficient being connected with those of
the original equations by an equation of the second degree.
The expression for the displacement, then, is of the same
form as in the case of a single vibrating medium; but
the relation between the coefficients of the time and of the
distance, and consequently the velocity of propagation, will
be very different.

26

The quadratic equation above alluded to expresses the
relation of these coefficients, or, in other words, the relation
between the period of vibration and the length of the wave.
When the action of the molecules of the ether and of the
body, inter se, and on one another, is governed by the same
law, this equation is resolvable into simple factors, one of
which only seems to belong to the problem, the other giving
an expression for the velocity of propagation independent of
the length of the wave. The author accordingly proceeds
to develop the former of these formule, converting the triple
sums which it contains into triple integrals, according to the
method of M. Cauchy.

Among the consequences deducible from this development
is the following:—In the expanded expression for the velocity
of propagation, each term consists of two parts, one of which
is due to the action of the ether, and the other to that of the
body. Itis not improbable that there may be bodies for
which the first or principal term is nearly nothing, the two
parts of which it is composed being of opposite signs, and
nearly equal. In this case the principal part of the expres-
sion for the velccity will be that derived from the second
term; and, if that term be taken as an approximate value, it
will follow that the refractive index of the substance must be
in the sub-duplicate ratio of the length of the wave, nearly.
Now, it is remarkable that this law of dispersion, so unlike
anything observed in transparent media, agrees pretty closely
with the results obtained by Sir David Brewster in some of
the metals. In all these bodies the refractive index (inferred
from the angle of maximum polarization) increases with the
length of the wave. Its values for the red, mean, and blue
ray, in silver, are 3.866, 3.271, 2.824; the ratios of the
second and third to the first being .85 and .73. According
to the law above given, these ratios should be .88 and .79.

27

Professor Mac Cullagh made a verbal communication on
the probable nature of the light transmitted by the diamond
and by gold leaf. He conceives that as there is a change
of phase caused by reflexion from these bodies, so there is
also a change of phase produced by refraction; the change
being different according as the incident light is polarized in
the plane of incidence, or in the perpendicular plane. Con-
sequently, if the incident ray be polarized in any interme-
diate plane, the refracted ray should be elliptically polarized ;
and on examining the light transmitted by gold leaf, this
was found to be the case. Of course the same thing is true
of the light which enters the other metals, and which is sub-
sequently absorbed. ‘The same remark explains the appear-
ance of double refraction in specimens of the diamond which
give only a single image ; and it is likely that other precious
stones will be found to possess similar properties. Mr.
Mac Cullagh has obtained a general formula for the difference
of phase between the two component portions of the refract-
ed light—one polarized in the plane of incidence, and the
other perpendicular to it. He finds from this formula, that
the difference of phase, which is nothing at a perpendicu-
lar incidence, increases until it becomes equal to the charac-
teristic at an incidence of 90°; and when the light emerges
into air, the difference of phase is doubled. The formula
has not yet been submitted to the test of experiment.

Mr. Mac Cullagh then read a paper “on the Laws of
Crystalline Reflexion and Refraction.”

In this paper the solution of the following problem is
given for the first time :—

Supposing aray of light, polarized in a given plane, to fall
on a doubly refracting crystal, it is required to find the plane
of polarization of the reflected ray, and the proportion be-
tween the amplitudes of vibration in the incident, the reflect-
ed, and the two refracted rays.

28

The constructions to which the author has been led by
his theory are extremely simple, and may be explained most
easily by referring to a paper which he has already pub-
lished in the Transactions of the Academy, vol. xvii. pp. 251,
252. To avoid circumlocution, he uses the term transversal,
to denote a right line parallel to the plane of polarization, of
a ray, and perpendicular to the direction of the ray itself.
When the transversal is spoken of as a finite magnitude, its
length is understood to be proportional to the amplitude
of the vibrations in the polarized ray. Let o (as in the
place just referred to) be the point of incidence on the crys-
tal, and or, o1’, the directions of the two refracted rays, the
points T, T’, being on the wave-surface. Corresponding to
the points T and 1’ on the wave-surface, there are two other
points, Pp and M, on a second surface which is reciprocal to the
wave-surface. The points Pp and m are derived from the
points T and 1’ by an easy rule which is given in the place
before cited. Now if we wish to find in what direction the
incident ray must be polarized in order that the ray or’ may
disappear, let us draw, through the point o, a plane a
perpendicular to the plane orp, and parallel to the right
line TP, which joins the corresponding points, T, P. This
plane a will intersect the planes of the incident and re-
flected waves in two right lines, which will be the transversals
of those waves; so that if the incident ray or wave be pola-
rized parallel to the first intersection, the reflected ray will
be polarized parallel to the second intersection, and there
will be only a single refracted ray or. <A right line
drawn through the point o, perpendicular to the plane
oTP, will lie in the plane a, and will be the transversal of the
refracted ray oT; and if, measuring from the point o, the
lengths of the three transversals represent the amplitudes of
the respective vibrations, the transversal of the refracted ray
or will be the diagonal of the parallelogram, whose sides are
the transversals of the incident and reflected rays. The prob-

29

lem is, therefore, completely solved in this case; and it is
obvious, that a construction precisely similar will apply to the
other case, in which or’ is the only refracted ray. The plane
B, which, in this second case, answers to the plane a in the
first case, is perpendicular to the plane or’, and parallel
to the right line T’m.

If the incident ray be polarized in a direction interme-
diate between the two transversal directions which give only
a single refracted ray, the incident vibration may be resolved
into two vibrations parallel to those two transversals. The
reflected vibrations arising from each of the component
incident vibrations are to be found by the foregoing rules,
and then to be compounded.

When the intersection of the planes a and B is perpendi-
cular to the direction of the reflected ray, this ray is polar-
ized parallel to that intersection, whatever be the plane of
polarization of the incident ray. The angle of incidence at
which this takes place is the polarizing angle.

When the refracted ray of or or’ is a normal to the wave-
surface, the plane a or B is the plane of polarization of the
ray. For example, if or be the ordinary ray in a uniaxal
crystal, the plane a contains the ray of and the axis of the
crystal.

The hypotheses from which Mr. Mac Cullagh has obtained
the foregoing laws, are these :-—

1. The density of the ether is the same in all media.

2. The vibrations are parallel to the plane of polarization.

3. The vis viva is preserved.

4. The vibrations are preserved: that is, the resultant of
the incident and reflected vibrations is the same as the resul-
tant of the refracted vibrations.

The author finds that his theory represents very accu-
rately the experiments of Sir David Brewster and M. Seebeck,
on the light reflected in air from a surface of Iceland spar.

30

DONATIONS.

A Description of the Shetland Islands, comprising an
Account of their Geology, Scenery, Antiquities, and Supersti-
tions. By Samuel Hibbert, M.D., F.R.S.E., &c. Pre-
sented by the Author.

Memoir on the Tings of Orkney and Shetland. By the
same Author.

Observations on the Theories which have beeen proposed
to explain the Vitrified Forts of Scotland. By the same
Author.

Flora Batava, No. 108. By H.C. Van Hall. Presented
by the Author.

The American Almanac and Repository of Useful Know-
ledge, for the Year 1837. Presented by the American Phi-
losophical Society.

January 23.
RICHARD GRIFFITH, Esq. in the Chair.

Captain Portlock read a notice of the occurrence of |
Anatifa Vitrea,* of Lamarck, in several localities on the
Irish coast. He commenced by enforcing the great impor-
tance of recording as quickly as possible the first discovery in
a new locality of any species of the animal or vegetable king-
dom, as tending to perfect the Fauna or Flora of the district
in which it is found; and pointed out the value of such local
Faunz and Flore in estimating the relations and mutual de-
pendencies of co-existing animals and plants, and affording
a basis of comparison by which future observers may be
enabled to test the probability of new organic beings occa-

* Lepas fascicularis, of Ellis, Montague, and other authors ; Lepas dilata, of
Donovan.

bl

sionally appearing on the surface of the present earth, in
the same manner as they appear to have occurred at very
distinct epochs in the more ancient world.

Captain Portlock then cited the various authors who
have mentioned this species of the pedunculated division of
Lamarck’s class, Cirrhipeda, beginning with its first disco-
verer, Ellis, who figured and briefly described it in his
Natural History of Zoophytes, published in 1786. It is
there stated to have been obtained in St. George’s Channel.
It was afterwards found on the western coast of England
by Mr. Brier and Mr. Montague, but is still considered
there (as stated by Turton in his Conchological Dictionary)
very rare. The Rev. Dr. Fleming communicated to the
Wernerian Society, between 1811 and 1814, his discovery
of the species in considerable abundance on the coast of the
Zetland Islands. Lamarck formed his species, vitrea, from
a specimen obtained on the shore of Noirmantier, an island
off the coast of Poitou, apparently the first noticed in France.
He had, however, seen a specimen of the Lepas Fascicularis,
sent him by Mr. Leach, and states his opinion that it is only
a variety of vitrea. A cluster of this species of cirrhipedz
having been sent to Captain Portlock by one of the Ordnance
Survey Collectors, from the north coast of Antrim in the
autumn of the last year, he was induced to make further
inquiry as to its previously known existence in Ireland, and
having mentioned the circumstance to Mr. R. Ball, was in-
formed by him of four cases of its occurrence which he had
recorded, viz. on the coast of Youghal in 1819; coast of
Clare, 1823; coast of Clare, 1828; coast of Antrim, 1834.
These localities, therefore, taken with his own, consti-
tute a very wide range, and show that this species, still
considered as very rare on the coast of England, and appa-
rently equally so in France, has been traced round the
western shore from the north to the south of Ireland. Spe-
cimens of Anatifa Levis, Lamarck, (Lepas Anatifera, Linn.,)

32

accompanied those of vitrea. This is a common species all
round the Irish coast. Captain Portlock mentioned that
Mr. Ball had either in possession, or a record of, the follow-
ing species of cirrhipede, as Irish :

Anatifa Sulcata, (Lepas Sulcata, Mont.,) Youghall ; found
also by Mr. O’Kelly, near Kenmare.

Anatifa Striata, Lamarck, (Lepas Anserifera, Linn.,)
Dublin Bay.

Pollicipes Scalpellum, Lamarck, (Lepas Scalpellum,
Mont.,) found by Mr. W. H. Harvey in Dublin Bay.

Cineras Vittata, Leach, Lamarck, (Lepas Membranacea,
Turton,) attached to a plank cast on shore near Malahide.

Otion Cuvieri, Leach, Lamarck, (Lepas Aurita, Linn..,)
attached with a Cineras to a Balanus. The whole constitut-
ing a very large proportion of the pedunculated cirrhipedes,
at present known in Great Britain.

———

Professor Lloyd exhibited to the Academy some modi-
fications which have been recently made in the construction
of the Magneto-electric Machine.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1837. No. 3.

February 13.

Rev. F. SADLEIR, D.D., F.T.C.D., Vice-President,
in the Chair.

Rev. Thomas Knox, George J. Knox, Esq., and Andrew
S. Hart, Esq., F.T.C.D., were elected members of the

Academy.

Doctor Gregory read a paper, entitled, ‘‘ Examination
of Eblanine, a substance discovered by Mr. Scanlan, and
exhibited by him at the Meeting of the British Association.”
By Professor Apjohn and Dr. Gregory.

Eblanine is contained in pyroxilic spirit. It is yellow,
crystalline, fusible at 318°, volatile in a current of air at 300°,
not subliming in a close tube unchanged. It is insoluble in
water and alkalies, soluble with a strong yellow colour in’
alcohol, ether, and concentrated acetic acid. Strong sul-
phuric acid strikes with it a deep bluish purple colour, soon
passing to brownish black. Strong muriatic acid dissolves
it sparingly with a very fine and intense purplish red colour,
which also slowly passes into brownish black. Nitric acid
dissolves it, and from the solution water separates a yellow
solid, which, at a certain temperature, is decomposed sud-
denly with a very feeble explosion. Chlorine converts it
into a dark resinous matter.

D

34

Eblanine is anhydrous, and contains no nitrogen.

The mean of 4 analyses gave as the composition in 100
parts, W

Carbpnj1 7 if.) 86) 7a
Hydrogen,. . . 5:609
Oxygen, . . . 19.116
The composition, calculated according to the formula
C,, H, 0,, would give
Carbon,... TRKie ao. 9
Hydrogen, °. 57) 30)
Oxygen) iiyaey 18:91
But as we have as yet no means of ascertaining the atomic
weight of eblanine, this result must be viewed merely as an
approximation.

Eblanine cannot be confounded with any known sub-
stance, and must rank as a curious addition to the list of
compounds produced in the destructive distillation of wood ;
to which must also be added, aldehyd, a substance lately
discovered by Liebig, but first pointed out as existing in
pyroxilic spirit, by Mr. Scanlan, who obtained it before the
discovery of Liebig was known in Dublin.

Sir William Betham read the first of a series of papers
‘On the Cabiric Mysteries and Phoenician Antiquities.”

In this paper the author stated his conviction that the
Cabiri were a secret society or brotherhood, who concealed
their acquirements in science and the arts from all but the
initiated ; that this society originated with the Phcenicians,
and was for a very long period confined to that people and
their colonies; that the arts of navigation, mining, &c., the
science of astronomy, and indeed all other branches of know-
ledge with which they were acquainted, were enveloped by
them in mystic fables and allegories, to conceal them from
the vulgar; and that from these was derived the whole sys-
tem of mythological theology of the Greeks and ‘Romans.

39

The word Cabiri, in Celto-Phcenician, literally means the
confederacy or brotherhood of science. Cabar is a confede-
racy or secret society, 7, of science. The four degrees or
steps of initiation into this order, were named Axieros, Ax-
tochersa, Axiochersus, and Camillus, or Casmillos. ‘These
were made deities by the Greeks, the Phcenicians themselves
encouraging or perhaps propagating an error, the explana-
tion of which was part of the secrets of the confederacy.
The confederacy itself originated at a very early period of
Pheenician history, and seems to. have partaken of the es-
sence of the policy by which that people aimed to keep the
world in ignorance, and to carry on in secret their extensive
operations in commerce, navigation, and mining; the se-
crets of these arts being enveloped in terrible mysteries,
which deterred the ignorant and unenlightened from inter-
ference. By these means they succeeded in securing to
themselves for ages the exclusive sovereignty of the seas,
the entire commerce, and the greater part of the wealth of
the world.

The discovery of the identity of the Celtic and Pheenician
tongues has led to the exposition of the true meaning of the
names and nature of these imaginary Cabiric deities, which
the author explained as follows :—

Axieros.—The first step.— The initiation by the shedding
of blood.

Axiochersa.—The second degree.— The communication
to the ear of the more important secret of silence.

Axiochersus.—The third degree.— The communication to
the ear of the silent secrecy of experience.

Camillus, or Casmillos—The fourth degree.— The per-
fection of all knowledge.

Vulcan is said to have been the father or founder of the
Cabiri. This name in Celtic signifies the profound metallur-
gist, smith, or worker in metals ; Fol Gaun, or Bal Gaun, the
lord smith. It is also worthy of remark, that in Sanconia-

D2

36

thon’s account of the descent or pedigree from the first man,
Vulcan stands contemporary with Tubal Cain of the Scrip-
tures, who was the “instructor of every artificer in brass
and iron;” and this last name is of the same signification in
the Celto-Phcenician, i.e. the celebrated lord smith, or me-
tallurgist.

The author concluded by observing, that such members
of the Academy as were Freemasons must be struck by ana-
logies which he could not more clearly explain.

DONATIONS.

A copy of the Ordnance Survey of the County of Cavan,
in 46 sheets. Presented by Lieut. Colonel Colby.

Asiatic Researches, Vol. 20, Part I. Presented by Mr.
Princep. :

Anglorum Feria, Englandes Holydayes, §c. Presented
by W. H. Fitch, Esq.

Transactions of the Institution of Civil Engineers, Vol. 1.
Presented by the Council of the Institution of Civil En-
gineers.

Letters on the Conduct of Charles Purton Cooper, Esq.,
Secretary to the Commission of Public Records, and on the
General Management of the Commission. By Mr. Henry
Cole. Presented by C. P. Cooper, Esq.

Letters from Eminent Historical Writers, relating to the
Publications of the Board of Commissioners on the Public
Records. Presented by the same.

Observations, Letters, and Opinions of the Commissioners,
on the Constitution and Duties of the Record Commission.
Presented by the same.

37

February 27.

Rev. B. LLOYD, D. D., Provost, T.C.D., President,
in the Chair.

Mr. Petrie read a paper, being an account of a valuable
Irish MS. belonging to the Earl of Roden, (of which a
transcript has been recently made for the Academy, under
the direction of Mr. Petrie, by Mr. Eugene Curry,) with
a biographical notice of its author.

This MS., which is of great celebrity among Irish scho-
lars and historians, was compiled between the years 1650
and 1664, by Duald Mac Firbis, from various ancient
historical works many of which are now lost, and contains
the most complete historical account of the several tribes
who made settlements in Ireland and Scotland, with ge-
nealogies of all the principal families descended from them.
Its compiler was the last of the hereditary antiquaries of
Lecan Mac Firbis, in the county of Sligo, by whom the ce-
lebrated MS. called the Book of Lecan, now in the Library
of the Academy, was compiled in the fourteenth and fifteenth
centuries; and it is a valuable supplement to the genealogical
portion of that great work, the pedigrees being, in most
instances, continued down to the time of the writer. It also
contains a vast quantity of matter not to be found in any
other works, as historical and topographical poems, &c., but
particularly an account of the Danish and Anglo-Norman
families, which is of inestimable value.

The MS. is a small thick quarto on paper, containing
about 1000 pages, and is wholly in the hand-writing of
Mac Firbis, with the exception of a small portion in the
hand-writing of Michael O’Clery, the chief of the celebrated
annalists popularly called the Four Masters. The transcript
made for the Academy agrees in every respect with the ori-
ginal, with which it has been compared most carefully by

38

Mr. O'Donovan. It is, however, more perfect; as many
chasms caused by stains and other injuries have been sup-
plied from abstracts of the work made by the compiler him-
self, and many corrections and much additional matter found
in those abstracts have been inserted. The Academy’s
transcript may therefore be considered the only perfect copy
of the work now existing.

Professor Lloyd read a note on the Aurora Borealis of
the 18th inst., of which the following is an extract :—

“‘ At a quarter past ten o'clock, on the night of the 18th
inst., my attention was called to a remarkable ruddy ap-
pearance in the eastern part of the sky, which, at first view,
- seemed to arise from the reflexion of a fire. Ona more at-
tentive examination, however, it was soon evident that the
appearance was purely meteoric. It was, in fact, an auroral
phenomenon, though of a very peculiar kind.

“Tt was bright moonlight, and Mars had just appeared
after his occultation by the moon. The sky was entirely
without clouds ; but the northern, eastern, and western seg-
ments were covered with a curtain of diffused Aurora, re-
sembling a luminous vapour. This curtain was lifted from
the horizon on the east and west, and exhibited a deep
blue sky. But the distinguishing appearance was, that
large masses of this light, especially towards the east and
north-east, were of a blood-red colour, which presented a
vivid contrast to the blue of the sky beneath. A large
patch of this red light, about 40° from the horizon to the
eastward, was the most remarkable. It continued distinctly
visible for upwards of half an hour; and its motion was so
rapid that in this time it had advanced from about due east
to a point nearly south-east.

There was a mass of white streamers to the north, which
reached nearly to the zenith, and pointed somewhere be-
tween the magnetic and due north. At half past ten o’clock,

a ey

39

a brilliant and well defined stream of light of the blood-red
colour appeared a little to the south of west, and seemed to
be a disjointed portion of the eastern red mass. A few minutes
after its appearance, a large mass of white auroral light be-
gan to rise rapidly from the northern horizon; at the same
time the northern streamers became much more vivid, and
took a fan-like appearance, converging to a point not far from
the zenith. There was no appearance, however, of Corona.
Shortly after, (about 10%. 40’), a portion of the light of these
streamers, about midway between a Ursz and Polaris, as-
sumed the unusual blood-red tint, and continued of this
colour for several minutes.

** Before 11 o'clock all the peculiar appearances had
nearly gone; and there remained nothing but the faint lu-
minous clouds, with light streamers to the N.N.W. These
streamers were still playing at 12 o’clock, and extended
from the zenith to within about 30° of horizon.

“The thermometer stood at 38° fahr., and the barometer
at 29.786 inches. The wind was dry and piercing.”*

* The following note, by Mr. Bergin, supplies the account of the early part of
the phenomenon :—

“On alighting at the Dunleary station at 7 o’clock, (from the Railway,) we
observed a magnificently coloured crimson Aurora as a broad mass to the westward;
and our first impression for a moment was, that it was the light from one of the en-
gine furnaces reflected from a cloud of steam. It extended from near the horizon
towards the zenith, with frequent flashes or streamers within itself. From the main
mass, round by the north, and onward to the east, the whole sky had a crimson or
carmine tint; and were it not for the brilliant moon (near the full) I do believe
the splendour would have equalled any I have ever heard of. * * * * The Aurora
assumed the general appearance of an arch; the first observed mass to the westward
being one leg which faded away toward the zenith, where there was a steady cir-
cular patch of great brilliancy of colour, and from thence, separated by a small in-
terval, was a faint limb descending to the eastern horizon. * * * * These appear-
ances continued with scarcely any change till near 8 o’clock. About 9 o’clock the
general appearances were much the same, save that the eastern limb of the arch
was not visible, and the western much more intensely coloured, and like a steady
column. * * * * Throughout, its limits had been well defined ; and it was perfectly

transparent, stars of the third, and perhaps the fourth magnitude being seen
through it.”

40

‘

Professor Lloyd read a note on a new electrical phe-
nomenon.

The Rev. J. H. Todd, F.T.C.D., gave a short account
of a MS. of the four Gospels, of the seventh century and in
Irish characters, which is preserved in the Library of his
Grace the Archbishop of Canterbury at Lambeth. The
volume is a small quarto, in the minute hand called Caroline,
common to all Europe in the reign of Charlemagne, but now
used only in Ireland, and known as the Ivish character. The
present volume appears to have belonged to Maelbrigid
Mac Dornan, or Mac Tornan, who was Archbishop of Ar-
magh in the ninth century, and died A. D. 925. By him it
was probably sent as a present to Athelstan, King of the
Anglo-Saxons, who presented it to the city of Canterbury.
These facts are inferred from the following inscription in
Anglo-Saxon characters, (and in a hand of the ninth or be-
ginning of the tenth century,) which occurs on a blank page
immediately following the genealogy in the first chapter of
St. Matthew.

YM MAEIELBRIDVS. MAC.
DVRNANI. ISTVM. TEXTYM.
‘PER. TRIQVADRVM. DO.
DIGNE. DOGMATIZAT.

PM AST. AETHELSTANVS.
ANGLOSEXANA. REX. ET.
RECTOR. DORVERNENSI.
METROPOLI. DAT. PER. ZVVM.

The former part of this inscription Mr. Todd professed
himself unable to translate to his own satisfaction. Textus,
in the Latinity of the middle ages, is a term frequently em-
ployed to denote the Four Gospels; but dogmatizare, in
the same dialect, is generally used in a bad sense, to assert
--erroneous or heretical opinions, a signification which it can-
not well bear here: triguadrus, when used as an adjective,

Al

is equivalent to tripartitus, trisected, and its use as a sub-
stantive is rare.

The mention of Maelbrigid Mac Dornan, in connexion
with the present volume, might be relied upon as sufficient
evidence of its Irish origin; but there is proof of this fact
still more conclusive. In the lower margin of the page,
which contains the account of our Lord being compelled to
bear his cross, (from ver. 24 to 32 inclusive, of the 27th chap-
ter of St. Matthew,) there is the following note in the Irish
language, and in the hand-writing of the original scribe:

mon aryapyra F COJMDIA
| njme Jj calman

The second word is probably a contraction for ayranan ya,
or as it would now be spelt, eayonojn ya; the whole there-
fore, in modern orthography and without contractions, is to
be read as follows:

Mont eayonoyyt 7a Foyt CojMoJa nJME azuy calman.

Great dishonour this to the God of heaven and earth.

The discovery of this MS., and the satisfactory proof

which these facts afford of its Irish origin, are important, as
adding another to the many instances with which we are al-
ready acquainted, of the employment of Irish scribes in the
transcription of the Scriptures during the sixth and seventh
centuries. Itis now well ascertained that almost all the sacred
books so highly venerated by the Anglo-Saxon Church, and
left by her early bishops as heirlooms to their respective
sees, were obtained from Ireland, or written by Irish scribes,

DONATIONS.

The Mining Review, and Journal of Geology, Mineralogy,
and Metallurgy. Conducted by Henry English, Esq.,
F.G.S., &c. No. IX. (New Series.) Presented by the

Editor.

42

March 16. (Stated Meeting.)

Rev. B. LLOYD, D.D., Provost T. C. D., President,
in the Chair.

This being the day of the annual election, the following
Officers and Members of Council were chosen for the en-
suing year:

President—Rev. Bartholomew Lloyd, D. D.

Lreasurer—Thomas Herbert Orpen, M. D.

Secretary—Rev. Joseph Henderson Singer, D. D.

Secretary to Council—Rev. Richard Mac Donnell, D. D.

Secretary of Foreign Correspondence—Sir Wm. Betham.

Librarian—Rey. William Hamilton Drummond, D. D.

Committee of Science.

Rev. Franc Sadleir, D. D., Rev. Richard Mac Donnell,
D. D., Sir William Rowan Hamilton, Rev. Humphrey Lloyd,
James Apjohn, M.D., James Mac Cullagh, Esq., Captain
Portlock, R. E.

Committee of Polite Literature.

The Archbishop of Dublin, Rev. Joseph Henderson
Singer, D.D., Andrew Carmichael, Esq., Samuel Litton,
M.D., Rev. William Hamilton Drummond, D.D., Rev.
Charles Richard Elrington, D. D., William West, M. D.

Committee of Antiquities.

Rey. James Henthorn Todd, Thomas Herbert Orpen,
M. D., Hugh Ferguson, M. D., Sir William Betham, George
Petrie, Esq., Rev. Caesar Otway, Dean of St. Patrick’s.

Professor Kane read a paper, entitled “‘ Researches on
the Combinations derived from Pyroacetic Spirit.”

In order to understand the relation between the following
bodies and pyroacetic spirit, the atomic weight of the latter

45

must be considered as representing four volumes of vapour,
and its formula written c,u,0,. It has been found to give
a series generally analogous to that of ordinary alcohol, and
Professor Kane proposes for it the name Mesitic Alcohol.

By means of sulphuric acid there is obtained a fluid
colourless, of an alliaceous odour, boiling at 276. F. and having
the composition c,H,, to which is given the name Mesity-
lene.

By acting on mesitic alcohol with perchloride of phos-
phorus there is generated phospho-mesitylic acid, and a
compound fluid heavier than water, which has the formula
c, H, cZ; and, by the decomposition of the latter by means of
potash, a body c,u,0. ‘These may be considered either as
containing Mesitylene, or a hypothetic radical Mesityl,
thus:

C,H, +0. Oxide of Mesityl. | c,H,-+-Ho. Hydrate of Mesity-

lene.
c,H,-+cl. Chloride of Mesi- ; c,H,-++-Hcl. Muriate of Mesi-
tyl. tylene.

By the action of phosphorus and iodine on mesitic alcohol,
there is produced an iodide of mesityl, having the formula
C, H, I.

Oxide of Mesityl unites with sulphuric acid in two pro-
portions, forming the sulphate and the bisulphate of mesityl;
both of these are acid, and unite with bases forming well
characterized salts.

The salts of the former are called sulphomesitylates, and
of the latter persulphomesitylates; and a very anomalous
character in these salts is, that the quantity of the inorganic
base is such as could neutralize the whole of the sulphuric
acid which they contain. ‘Thus the sulpho-mesitylate of
lime has the formula

so, +C, H,0 +Cca0-+ HO;

AA

and the persulphomesitylate of lime
2so0, +c, H, 0-+2ca 0+ HO.

When an excess of phosphorus is used in the process
for making iodide of mesityl, there is obtained in the retort
a white matter in silky crystals, which dissolves in water, is
very acid, and forms well characterized salts, which, when
heated, take fire and burn with a well marked flame of phos-
phorus. This acid is termed hypophosphomesitylous acid ;
and the formula of the hypophosphomesitylate of baryta is

P,O0+C,H,O+Ba0-+H0.

In the decomposition of mesitic alcohol by perchloride
of phosphorus there is obtained an acid which gives a soda
salt crystallizing in rhombs which contain water of crystal-
lization. ‘Their formula is

P, 0, +Nao+c,H,0+6nHo0.

Professor Kane stated that he had obtained also thé aldehyd
of the mesityl series, as well as bodies procured by the action
of chlorine and iodine on mesitylene, and the acids which
are generated by the oxidation of mesitic alcohol, the history
of which bodies shall form the subject of another paper.

The empyreumatic oil, which is produced in small quan-
tity when mesitic alcohol is prepared by distilling acetate of
lime, has been submitted to analysis by Professor Kane, and
its composition found to be c,, 4,0. It therefore belongs to
the family of which oil of turpentine is the base, and is po-
lymeric with camphor, and the pinic, sylvic, and copaivic
acids.*

Dr. Apjohn read a paper “‘ On the Specific Heats of the
Aeriform Fluids.”

The first part of this communication was an analysis of,
and some critical remarks upon, the labours of those who

* In this abstract the atomic weights are taken, Hydrogen = 1. Oxygen=8.
Carbon = 6, 13.

45

had preceded the author in the same investigation, parti-
cularly those of Dulong. Dr. Apjohn’s own method was
then detailed. In a paper read by him before the Academy

in April, 1835, the equation* f” = f’ — aud x? was proved

*30
to include the solution of the dew-point aay But the
factor a in this expression, which is obviously equal (when
the a or gas is dry, or in other words, when f”=0) to
me 28
48d °°
gas which is supposed to be the subject of experiment.
Hence if f’ and d be determined for the various aeriform
fluids by observation, their relative capacities for caloric
‘can be compared. Such is the principle of the method.
Two distinct series of experiments were then detailed,
from the second of which, as comprehending those which he
conceives to be most accurate, the author has deduced the
following table of specific heats :

= is the specific heat under a given volume of the

Specific Heats of equal Volumes.

Atmospheric Air,. . . . . 1.000
INieee; iis 28s stuns, GOS
Oxygen, (by aldutselo ae pene s
BIY@TORERg crres. 4s, dines -pyer ee
GasboutevAcibesd «. «. 02... BI9S
Carbonic Oxide ~.. . >. . ~~» ~.996
Witrous Oxide, 0... td's. 1.199.

Dr. Apjohn conceives himself justified in drawing from
his researches the following conclusions :

1°. All gases have not under equal volumes the same
specific heat.

2°, This law is not even true of the simple gases.

*d=t —t’ the difference of the temperatures shown by a wet and dry ther-

mometer, and f" is the elastic force of vapour at temperature t’.

46

3°. There does not appear to be any simple relation be-
tween the specific heats of the gases, and their specific gra-
vities or atomic weights.

A paper was then read “ On some remarkable Salts, ob-
tained by the action of Ferrocyanide of Potassium cn Sulpho-
vinates and Sulphomethylates.”* By William Gregory, M. D.,
F.R.S. E., &c.

The Committee appointed to examine the Treasurer’s
Account reported as follows :

** Kxamined the above Account,t with the vouchers pro-
duced, and found it to be correct ; and we find that there is
a balance in bank of £284 6s. 5d., and in the Treasurer’s
hands £110 16s. 1d., making a total balance of £395 Qs. 6d.
sterling.

** (Signed,)
** Franc SADLEIR,

“C. R. Exrineton.
** Feb. 20th, 1837.”

*‘ The Treasurer reports that there are the following por-
tions of Stock in the Bank of Ireland to the credit of the
Academy :

* £1500 in the 3 per Cent. Consols.

** £1500 in the 33 per Cent. Government Stock, being the
Cunningham Fund.

** (Signed,)

‘FRANC SADLEIR.
“ Feb. 20th, 1837.”

* An abstract of this paper will be given in the next number of the Proceedings.
+ Entered in the Treasurer’s Book.

47

DONATIONS,

Observations on the Evidence taken before the Committee
of the House of Commons, on the Record Commission in 1836,
and the Report so far as it refers to the Irish Records. By
Sir William Betham, Ulster King of Arms, &c. &c. Pre-
sented by the Author.

An Oration on the Important Advantages derivable from
Philosophical Instruction. By Henry W. Dewhurst, Esq.
Presented by the Author.

A Practical Treatise on the Management and Diseases of
Children. By Richard T. Evanson, M.D. Presented by
the Author.

The following is the extract from the letter of the Baron
de Donop to Sir William Betham, referred to in the last
number of the Proceedings:

* Qur literati in Germany have been of late much
excited and interested by the alleged discovery of the MS.
Translation of the History of the Phenicians, by Philo
Biblius, now printing at Bremen. It is generally considered
a modern fabrication ; but at the same time it is not easy
to say by whom. Time will, at no very distant period, de-
cide the question, as upwards of 100 pages of the Greek
text have been already printed.

“For myself, I am inclined to think it genuine. A close
and careful examination of a portion which has appeared at
Hanover, has convinced me that no fabricator could have
formed that work, unless he had been profoundly acquainted
with the writings of Vallancey, O’Connor, your own works,
and those of all others who have asserted the identity of
the Phoenician Punic language with that of Ireland; for it is
that tongue which is recognized in all the names, almost

without exception, which in the mouth of Sanconiathon
ought to be Pheenician.

48

“The most surprizing fact of all is, that in the Chronicles
of O’Connor,* which is a book almost unknown in Germany,
are to be found accordances not to be mistaken. For in-
stance, what the Chronicles call aot-magh, Sanconiathon calls
Ma thai. O’Connor says 00)-maz, a flat country, or region
of plains, and Mathai-Bal is the first king of the Syrian
Pheenician plains of Sidon, according to Sanconiathon. His
name, therefore, is nothing more than Magd-ai-Bal—and, as
in the Chronicles, this aoi-mag is the Sidonian Hamath of the
ancients—the same Mathai-Bal of Sanconiathon, who caused
to be constructed the fortress of Hamath on the plains, to
defend himself against the neighbouring mountaineers.

“* Maol, in the Chronicles, is the name of one of the kings
of the Gael. The same name appears on the famous Lybian
stone of Tucca. Sanconiathon places Be-maol at the head of
the kings of Sidon, and his descendants are called O-Christo-
bi-mal, which is evidently nothing more than ceapt-o-
be-maol.

«Between 1020 and 1008, B. C., the Chronicles mention
Jac-yam, king of Phoenicia, a conqueror, jealous of the dig-
nity of his empire, to whom all the natives of Spain were
tributary. At the same period, according to Sanconiathon,
‘there reigned a king of Pheenicia of the same name, Joram—
the Hiram of Solomon—and that Joram was not only master
of the west, but extended his rule to the Isle of Ceylon.

*‘The most interesting portion of all Sanconiathon, is
the Pheenician periplous, in which is set forth an enumera-
tion of the Phoenician colonies, extending to the Canary
Islands, with their sea and land forces, made by order of

Joram.”

* The Chronicles mentioned by Baron de Donop are the Chronicles by
Mr. Roger O’Connor, which are nothing more than a paraphrastic version of the

Milesian story.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1837. No. 4.

March 16.
(Continued from last Number.)

“On some remarkable Salts, obtained by the action of
Ferrocyanide of Potassium on Sulphovinates and Sulpho-
methylates.” By William Gregory, M.D., F.R.S. E., &c.

When ferrocyanide of potassium is added to sulphovi-
nate of lime, a precipitate appears, which, when heated,
gives off hydrocyanic ether. This salt (called a) contains
iron, calcium, potassium, cyanogen, and the base of ether.

The mother liquid is found to contain a salt B, very so-
luble in water and alcohol, which, also, on being heated,
yields hydrocyanic ether. The ingredients of B are sulphu-
ric acid, potash, ether, and cyanogen.

In order to avoid the confusion which might result from
the use ofa salt of lime, (as Mosander has shown that ferrocy-
anide of potassium produces in the salts of lime, generally,
a precipitate consisting of iron, calcium, potassium, and
cyanogen,) the author next tried sulphovinate of potash.
By the action of ferrocyanide of potassium on this salt he
got a salt c, corresponding to a, but different; and another
salt D, identical with B.

When sulphomethylate of lime was employed, two salts
Eand ¥F were obtained, exactly analogous to a and B: and
by employing sulphomethylate of potash he got G, corres-
' ponding to £, and 4, identical with Fr.

E

50

As it seemed likely that the study of any one of these
reactions would explain all the rest, the author began with
the analysis of cg and u, of which he had a larger supply
than of the others.

G is lemon yellow, transparent, soluble in water, insoluble
in alcohol, crystallizing in square tables much resembling
those of ferrocyanide of potassium. By exposure to a heat
of 212°, it loses 13.5 per cent. water of crystallization, and
becomes opaque. More strongly heated it is decomposed,
giving off hydrocyanate of methylene, = c, H, cy or Me cy.
The analysis corresponds with the formula 4 x cy, 3 Fe cy,
M cy, 8 Aq.

H is white, very soluble in water and alcohol, crystallizing
in square shining tables. It closely resembles sulphome-
thylate of potash, but differs from it in being anhydrous, in
containing cyanogen, and in yielding hydrocyanate of me-
thylene when decomposed by heat. Its analysis agrees with
the formula 6s 0,,3k 0, M0, Mcy.

If 3 equivalents of ferrocyanide of potassium be supposed
to act on 3 of sulphomethylate of potash there is the follow-
ing equation:

3 equiv. Ferrocyanide 3 equiv. Sulpkomethylate
6 K cy, 3 Fe cy + 6s0,8kK0,8mMo0=
1 equiv. @ 1 equiv. H
= 4kcy,3Fecy,Mcy + 6s0,, 3K0, MO, MCy

+2ko. 2.e. 2 equiv. potash. In conformity with this ex-
planation, the liquid in which 4 crystallizes is alkaline.

If this explanation be admitted, it will of course apply,
mutatis mutandis, to the salts a B,cp, EF. ‘The author,
however, is not yet satisfied that the salts which he analyzed
may not have been mixtures, perhaps in definite proportions.
No doubt can be entertained that new salts have been
formed, but the close resemblance between their properties
and those of the salts which yield them, renders the task of
purifying and analyzing them one of great difficulty.

(To be continued.)

April 10.

Rev. B. LLOYD, D.D., Provost T. C. D., President,
in the Chair.

Rev. Charles William Wall, D.D., F..T.C.D., Robert
William Smith, M. D., and William Armstrong, Esq., were
elected Members of the Academy,

A paper was read “On a new variety of Alumn,” by
James Apjohn, M. D., M.R.1.A., Professor of Chemistry
in the Royal College of Surgeons, Ireland.

This paper commenced with a brief description of the
physical characters and chemical properties of the mineral
in question, which was found about 600 miles to the north
of the Cape of Good Hope, near Algoa Bay, where it occurs
in strata whose aggregate thickness is about twenty feet.
The specimen described is composed of transparent threads
or fibres, exhibiting a beautiful silky lustre, and in appear-
ance closely resembling satin-spar or the finer forms of ami-
anthus. In taste, solubility in water, and other properties, it
corresponded with ordinary alumn. It was also easily shown
to contain sulphuric acid and alumina, but in addition it
contained a base which, though precipitated like alumina
by potash, was not redissolved by an excess of the alkali.
This, upon examination, turned out to be protoxide of man-
ganese. There was no alkali, but about one per cent. of
sulphate of magnesia.

In the first attempt at effecting the analysis of the mine-
ral it was found that alumen and protoxide of manganese
could not be separated perfectly by potash, as some of the
oxide was taken up by the alkali, while a considerable quan-
tity of alumen was left behind with the oxide. The author
explained a method of overcoming this difficulty, the parti-
culars of which are given in detail in the paper. The fol-

E2

52

lowing are the results—the numbers in column (2) being the
quotients got by dividing those in column (1) by the oe
tive atomic weights:
i) e@-. @)
Sulphuric Acid, . . . 32.79 .817 4.000
Alumina, .. . . . 10.65 .414 2.026
Oxide of Manganese, . 7.33 .205 1.003
Sulphate of Magnesia, . 1.08
Water of Crystallization, 48.15 5.350 26.315

100

The numbers in column (3) being almost exactly the in-
tegers, 4,2, 1, and 26, show that the substance analyzed is a
true alumn, having, as respects its acid and bases, the same
formula

(3so,, Ad, 0, -+S0,, Mno + 26HO)
with all the known species of that genus, and the same
number of atoms of water with soda alumn. It differs from
all those previously known in containing no alkali, this being
replaced by protoxide of manganese. As an additional pe-
culiarity Dr. A. observed that it did not appear susceptible
of assuming the octohedral form.

The paper concluded with some remarks upon the pro-
bable existence of an alumn containing no metal but manga-
nese, and upon certain difficulties in the doctrines of isomor-
phism, suggested by some of the varieties of this class of salts..

Captain Portlock brought under the notice of the Aca-
demy some peculiar habits of the Otus Brachyotos, or short-
eared owl, lately observed by Captain Neely, whilst collect-
ing for the Ordnance Survey of Ireland.

This species of the sub-genus otus being migratory, is
much rarer than the otus vulgaris, or long-eared owl, and it
differs from it in many striking respects, such as the small
size of the elongated feathers, commonly called ears, which

53

in this species can only be discerned when the bird is living,
and in its tendency to diurnal habits. But in the instance
now recorded it exhibits other peculiarities of habit which
afford a still more remarkable line of distinction. The point
of Magilligan, forming the Derry side of the opening of
Lough Foyle to the sea, is studded at its extremity with nu-
merous sand hillocks, in which the rabbits burrow and the
sheldrakes lay their eggs, as in other similar localities. But
kere a new occupant for the burrows of the rabbits appears in
the otus brachyotos. These birds are regular in their au-
tumnal appearance, and are seen to sit at the openings of the
burrow-holes, and to run into them when disturbed.

Captain Portlock having directed further attention to the
fact, and pointed out the necessity of guarding against any
source of fallacy, the truth of the first statement was fully
established, more than one having been shot on emerging
from the holes, and another actually caught in a trap at the
mouth of a hole when endeavouring to make his escape. This
interesting fact naturally recalls to recollection the stria cuni-
cularicis of America, described by Say; and Captain Port-
lock pointed out the great value of characteristic traits of
- habit in elucidating classification, and suggested the peculiar
importance of those described in his paper, in affording a
link of resemblance between the stria cunicularicis and the
otus brachyotos, and thereby facilitating the determination
of the true place, in natural classification, of the former,
hitherto considered doubtful.

The Secretary communicated the substance of a paper
** On the Conic Sections,” by James Booth, Esq.

The methods hitherto adopted in deducing the central
and focal properties of the conic sections, from arbitrary
definitions having appeared to the author defective in geo-
metrical elegance, he has endeavoured in this paper to derive

dA

them from new definitions, of which the following may be
considered the principal :

1. If two spheres be inscribed in a right cone touching
the plane of a conic section, the points of contact are called
foci.

2. The radical plane of these two “focal spheres” inter-
sects the major axis in a point called the centre.

The property from which the definition of a focus here
given is derived, although known for several years, has not
been hitherto applied further than to show that this point is
identical with the focus as usually defined.

By the help of the above definitions, and of the simplest
elementary principles, the central and focal properties already
known have been deduced, generally in one or two steps,
and several new theorems have been likewise discovered in
the development of the method.

A paper ‘‘ On Fluorine,” by G. J. Knox, Esq., and the
Rev. Thomas Knox, was read by Dr. Apjohn.

The authors, having taken a summary view of all the re-
searches on fluorine up to the date of the commencement of
their experiments in April, 1836, proceeded to describe the
vessels of fluor spar which they used in their first experi-
ments, and exhibited those which were latterly. found best
adapted for examining the gas. ‘These vessels were of fluor
spar lapped with iron wire for the purpose of equalizing the
temperature, so as to prevent the vessels from splitting on
a sudden application of heat. In place of a flat cover for
the vessels, fluor spar receivers were used, the cavities of
which were filled with ground stoppers of the same material.
On moving the receivers over the mouth of the vessel the
stoppers fall in, and their places are occupied by the
gaseous contents of the vessel. On the top of each of the
vessels is placed a flat slab of fluor spar, which answers the
purpose-of a table, upon which the receivers of the gases

59

can be moved. On the slab are four small depressions, in
which are placed the substances upon which the action of
the gas is to be observed, and over which the receivers,
when filled with the gas, can be slid. In opposite sides
of these receivers are drilled holes, into which are fitted,
air tight, clear crystals of fluor spar, through which the
colour of any gas in the receiver may be distinctly observed.
The yessels are supported on a stand over a lamp.

On heating pure fluoride of mercury in these vessels with
dry chlorine they obtained a colourless gas, (as seen through
the fluor,) having a heavy smell not pungent or irritating, and
thereby easily distinguished from chlorine or hydrofluoric
acid. When exposed to the air, it does not fume, as
would be the case were the slightest trace of hydrofluoric
acid present. The inside of the vessel is found coated with
crystals of corrosive sublimate. The gas does not extinguish

ignited phosphorus or red hot iron wire, and consequently
is (as Sir H. Davy conjectured) a supporter of combustion.
It detonates with hydrogen, forming hydrofluoric acid.
Placed over water, the solution (if such) has all the proper-
ties of hydrofluoric acid, i. e. acts on glass, reddens litmus,
and gives precipitates with lime and barytes. Placed over dry
litmus and Brazil wood paper, the former is reddened, and
the latter turned yellow; in no instance are they bleached.
When a receiver of the gas is placed over wet glass, the glass
is strongly acted upon; when the glass is carefully dried,
the action is not so strong as before. When a small piece
of dry glass is placed in a perforation in the interior of the
receiver, the glass is acted upon, but not more so than when
fluoride of mercury alone is in the vessel, from which they
conclude that fluorine does not act on perfectly dry glass.

To ascertain the action of the gas cn metals they found
it necessary to try the separate effects of hydrofluoric acid,
sublimed fluoride of mercury, and bichloride of mercury, in
order to distinguish the action of fluorine from that due

56

to the vapour of these substances. For this purpose bis-
muth and palladium at a moderate heat, and gold at a high
temperature, afforded distinguishing tests. 'To determine
the relative attraction of fluorine for those metals upon
which it does not act except at high temperatures, they used
as positive poles of a battery of sixty pair of plates, mois-
tened fluoride of lead, palladium, platinum, gold, and rho-
dium. The palladium and platinum were always acted
upon, the gold occasionally, and the rhodium never; from
which they suppose that fluorine might be obtained in an
insulated state, by electrolyzing fluoride of lead in a tube of
fluor spar, using rhodium as the positive pole.

They were unable to repeat M. Baudrimont’s experi-
ments in glass or fluor spar vessels. Supposing that the gas
he obtained was an oxide of fluorine, they heated in a dry
glass tube iodic acid and fluoride of mercury; supposing
that since iodine decomposes fluoride of mercury, the oxygen
and fluorine, being set free from their combinations with op-
positely electrical bodies (iodine and mercury), would be in
the most favourable condition for combining. On the appli-
cation of a moderate heat a pale yellow vapour rose in the
tube, which did not act on the glass, and bleached litmus.

Mr. Mallet read a paper “‘ On an hitherto unobserved
Structure discovered in certain Trap Rocks in the County of
Galway.”

The town of Galway is built upon a part of an immense
trap dyke, which extends under the sea and to a consider-
able distance up Lough Corrib. Large excavations for a
dock are now making in this rock at Galway, and afford
a convenient opportunity of examining its structure. It
separates the limestone on the east (which it tilts wp) from
the sienite of Cunnemara on the west, (which it overlies or
mingles with.)

57 a

Many of both adjacent rocks are found in an altered
state imbedded in the trap; which, with the filtering of the
limestone, prove the deposition a true dyke.

The mass of the rock consists of greenstone, sp. gravity
2.87, of a dark green, but frequently veined and mixed with
many other minerals.

In the centre of the exposed portion of the dyke rises a
large vein of nearly white hornstone, presenting very inte-
resting characters. It contains no imbedded minerals, and
is homogeneous in structure, but with a lamellar or pseudo-
crystalline arrangement. Its planes are vertical, and at its
Junction with the trap it is moulded to it, but not adherent,
and appears to have been formed from rocks at a greater
depth than the trap, and ejected through it. The minerals
found imbedded in this trap rock are various; specimens
have been obtained of mica, chlorite, felspar, albite, olivine,
augite, amphibole, epidote, apatite, adularia, chalcedony, sul-
phate oflime, probably anhydrite, baryto-calcite, arragonite,
calcareous spar, fluor spar, galena, iron pyrites, sometimes
magnetic. Epidote is found also on Mutton Island.

The general mass of this trap rock possesses a hidden
nodular structure, only developable by blasting. The no-
dules consist of precisely the same material as their matrix,
and having the same cohesion, they cannot be detached
by the hammer.

The nodules are from eighteen inches in diameter to the
size ofa nut; they are sometimes found pressed together in
masses with flat sides, like bubbles. Crystals occurring at
the surface of a nodule do not pass into the matrix, but are
truncated thereby. In some cases the nodular structure is
gradually obliterated, and the usual homogeneous one re-
places it.

This nodular formation is essentially different from any
hitherto described,—as the orbicular granite of Corsica and
South of France, the. onion stone of the causeway, &c.,

58

in which the nodule and the matrix are of different materials.
The present structure would appear to have been produced
by the ejection of the trap in a fluid state under the sea;
masses of which, cooling in their passage, fell again into the
liquid bed, and being enveloped, were heated nearly to the
temperature of the mass, and so adhered without losing
their outline. Where several fell together, and were exposed
to subsequent pressure, they would present the flattened
appearance before described; and when more deeply en-
veloped, and thus subjected to a higher temperature, the
nodular structure would again vanish by their complete
fusion.

It is even conceivable that the most capriciously varied
parts of this and other trap rocks may owe their origin
to the soldering together of nodules of heterogeneous matter,
projected from different depths, or at different times, or
subjected to successive coolings and heatings.

Professor Kane read a paper entitled ‘“‘ Researches on
the Compounds derived from Pyroacetic Spirit.” (Second
Series.)

When dry chlorine gas is passed into pure mesitylene,
C,H, muriatic acid is given off, and a compound body,
solid, in white prismatic crystals, is formed, giving on analysis
the formula c,u,cl. A yellow substance obtained by the
action of iodine on nascent mesitylene, but in too small
a quantity for analysis, is considered to be c, H, I.

When mesitylene is treated with nitric acid, copious red
fumes are given off, and a very heavy thick fluid obtained,
which gives on analysis the formula c,u,0,.. This fluid ab-
sorbs ammonia, and forms therewith a compound soluble in
water, and giving with most metallic solutions insoluble pre-
cipitates.

If pure mesitic alcohol be heated with nitric acid; there is

— —

59

a very violent reaction, and an explosive decomposition, if
distillation be attempted ; but by diluting with water a heavy
fluid is produced, which gives, on analysis, unsatisfactory re-
sults, owing, in the first place, to its decomposing with an ex-
plosion when heated, and, secondly, to its being always mixed
with some of the substance last described: the results ob-
tained indicate, however, as very probable the formula c,H, NO,.

To connect the above results, Professor Kane proposes
to assume as radical the body c,H,;, to which he gives the
name of pteleyl. Then
C,H, =c,H, +H. Hydruret of pteleyl or mesitylene.
C,H,cl =c,H, -+cl. Chloride of pteleyl.

C,H, =c,H, +1. Iodide of pteleyl.

C,H,0, =C,H,o+Ho. Hydrated oxide of pteleyl, the al-
dehyd of the mesitic series.

C, H, NO,= C,H, o-+no,. Hyponitrate of pteleyl.

The compound heavy liquid produced by the action of
chlorine on mesitic alcohol, was found to differ but little
from the description given by Liebig. Its formula, as given
by Dr. Kane’s analysis, is c,H, 0, c/,; and by the action of
bases it yields a metallic chloride, and a salt of a new acid
named by Professor Kane Pteleic Acid. 'This has not yet
been analyzed, but theory indicates for its composition the
formula c, H, 0,.

By the action of permanganate of potash on mesitic al-
cohol, there is generated a neutral salt of potash containing
an acid, to which is given the nameof the Perpteleic, whose
salts generally decompose themselves with facility into car-
bonates, and a salt of another acid to which the name of the
Acetonic Acid has been applied. 'The constitution of these
last three acids remains yet to be fixed by other experiments,
the author confining himself in the present paper to the
suggestion of that view of their composition, which, in the
absence of positive analyses, seems to him most likely to be
true.

60

Professor Kane exhibited to the Academy a balance
made by a German artist, having some peculiarities of con-
struction and adjustment.

It was resolved, “ that the Council be authorized, if they
deem it expedient, to purchase Mr. Underwood’s collection
of Irish antiquities.”

DONATIONS.

Flora Batava, Nos. 105, 106. By H. C. Van Hall. Pre-
sented by the Author.

History of the Presbyterian Church in Ireland. By
J. Seaton Reid, D.D. Vol. 1. Presented by the Author.

Le Primer Report des Cases et Matters en Ley resolus
et adiudges en Ley Courts del Roy en Ireland. Presented
by the same.

Transactions of the Royal Society of Edinburgh, Vol. 13,
Part Il. Presented by the Society.

Memoirs of the Royal Astronomical Society, Vols. 8 and 9.
Presented by the Society.

Philosophical Transactions of the Royal Society of Lon-
don, 1836, Part II. Presented by the Society.

List of the Fellows of the Royal Society, 80th November,
1836. Presented by the same.

Address delivered at the Anniversary Meeting of the
Royal Society, on Wednesday, November 30th, 1836, by
His Royal Highness the Duke of Sussex, K.G., &c. &c. &e.
the President. Presented by the same.

Supplement to the Account of the Rev. John Flamstead,
First Astronomer Royal. By Francis Baily, Esq., F. R.S.,
&c. &c. &c. Presented by the Author.

General Charte dir Geographischen Verbreitung und
des Ganges der Cholera, 1816—1837. By Emel Isensee.
Presented by the Author.

61

' Neues System zur Ubersicht der inneren Krankheiten des
Menschen. By the same.
Transactions of the Cambridge Philosophical Society, Vol.
6, Part I. Presented by the Society.

A Catalogue of the Collection of British Quadrupeds and
Birds, in the Museum of the Cambridge Philosophical So-
ciety. Presented by the Society.

Discussion of the Magnetical Observations made by Cap-
tam Back, R.N., during his late Arctic Expedition. By
Samuel Hunter Christie, M. A., F.R.S., &c.. Presented by
the Author.

April 24.

Rev. B. LLOYD, D.D., Provost T.C. D., President,
in the Chair.

Charles Graves, Esq., F.T.C.D., and Thomas Wise,
Esq., M. P., were elected members of the Academy.

A paper was read by Professor Kane ‘“ On Dumasine, a
new Fluid Substance isomeric with Camphor.”

This fluid is obtained in very small quantity in the dis-
tillation of acetate of lime for preparing mesitic alcohol. It
boils at 248°, is colourless, and of a powerful resinous smell.

Its composition by analysis is c,,H, 0. Thus:

Experiments. Theory.
Carbon, = 78,82 — 79,30
Hydrogen, = 10,46 — 10,35 100,00
Oxygen, = 10,72 — 10,35

The specific gravity of the vapour of this liquid was
found to be 5,204, air being 1. The theoretical density
from the formula above given, is 5,315, and one atom forms

62
two volumes of vapour. It has, therefore, the same density
as camphor, and like it may be considered as consisting of

1 volume of vapour of oil of turpentine, = 4,7643
3 volume of vapour of oxygen, = 0,5518

1 volume of vapour of dumasine, = 5,3156

Professor Kane read some passages of a letter from
M. Dumas, of which the following is an extract:

«* * * * ‘The researches, of which you have given me
an account,* promise the happiest results for science, I
cannot too much encourage you to complete them; you will
see by the journals that [ have communicated your letter to
the Academy of Sciences, where it met with the most honour-
able reception. Allow me to add, that M. Peligot and my-
self had obtained the carbo-hydrogen, c, H,, as well by sul-
phuric acid as by anhydrous phosphoric acid. We had
found, that potassium gave the product c,4,0, which you
have obtained in another manner, but we were stopped by
the composition of the sulpho-mesitylate of baryta, of which
you have given the explanation. These researches have
been made some time, but other matters caused us to neglect
them, and I do not now regret it, since they are in such
good hands. * * * *”

«<% * = * T announced yesterday to the Academy the
existence of the carbo-vinate of potash, which is

KO Co, + C,H,0 + CO,.

I also obtained, conjointly with M. Peligot, the carbo-methy-
late of baryta, which is

Ba. oco, + C,H, 0 + Co’.

In these bodies the acid changes very readily into carbonic

* On pyroacetic spirit. See Proceedings, pp. 42 and 58.

63

acid and alcohol, or pyroxylic spirit ; and it is remarkable,
that to form them it is sufficient to pass carbonic acid into a
solution of baryta in spirit of wood, or of potash in ordinary
alcohol. Ido not doubt but that similar bodies can be ob-
tained with pyroacetic spirit, but I shall leave to you the
pleasure of isolating them. * * * *”

«© * * * * T shall communicate next Monday to the
Academy, some observations which may interest you more
than any other person;* I mean on compounds very analo-
gous to double chlorides, and which I have obtained by
means of urea and the alcaline chlorides. Such bodies ap-

pear to me decisive on the theory of the amides. * * * *”

Sir William Betham read a paper ‘“ On the Affinity of
the Pheenician and Celtic Languages, and on the Cabiri and
their Mysteries.”

According to Sanconiathon, men in the third generation
from Protogonus began to worship the sun under the name of
Baal Samen. The Irish, and all the other Celtz, worshipped
the sun under the very same title of beal ramajn, the Lord
of Heaven; and the estuary of the Mersey is named stu-
arium Belasamena by Ptolemy.

It is probable, as asserted by many writers, that the
patriarch Noah was deified under the names Deucalion,
Ogyges, Saturn, Janus, &c. &c., for all these names are, in
the Celto-Phcenician, appositely significant of the attributes
of the supreme God: Deucalion signifies the circle of life,
or the sun’s course; Ogyges, the supreme wisdom ; Saturn,
the Lord; and Janus, the ruler of ages.

Sydyk, the 11th from Protogonus, according to Sanco-
niathon, is supposed to have been the patriarch Shem. He
is said to-have been the father of the seven Cabiri.. These

* For Dr. Kane’s researches on the double chlorides and amides of mercury,
see Transactions of the Royal Irish Academy, vol. xvii. p. 423.

64

children were probably the seven sciences personified and
deified. Thus Uranus was astronomy ; Neptune, navigation ;
Pluto, mining ; Jupiter Arotrius, (Ceres or Cybele,) agricul-
ture; Mercury, commerce or trade; Vulcan, mechanics or
metallurgy ; Apollo, music and the fine arts; to which was
added /sculapius, the inventor of medicine. It is remark-
able that Chrysor, or Vulcan, stands in the same generation
from Protogonus as Tubal Cain does from Adam.

The Cabiri were the inventors of navigation, and their
connexion with mining led to the supposition that they were
infernal deities. Phornutus has preserved a curious list of
the titles of Pluto, which he vainly attempted to resolve in
his own language, but which have all reference to mining
and metals in the Phcenician.

The Pelasgi are said by Herodotus to have occupied
Samothrace, and to have established the Cabiric mysteries,
which they afterwards, under the name of Tyrrheni, carried
into Italy. Accordingly we find the whole of Etruria re-
plete with names of Pelasgic or Pheenician origin, thus:

Tyrsenus—The old land—tjp reanaojr.

Tarchon—The head land—cjp cean, or Cantyre.

Attis—Rebuke, repulse—atayr.

Telephus—The land of death, or malaria—collam-ajye.

Auga—A bottom or flat valley.

Perusia—The city on the gentle slope of a river—bjon
way ja.

Ciris—The swift stream—cjpb ujy-ze.

Ttaly—The corn country—je-callam.

Argessa—The country of skilful tillage—ap zaora.

Ausonia—The noble old country—aoyr on ja.

Tyrsenia—The land of old age—cjn peanaoyy.

The island of Crete was one of the chief seats of the
Cabiri, where they bore the names of Curetes, Idzi Dactyli,
and Telchines. Nonnus says they were the sons of Neptune;
and Diodorus that they were allied to the ocean; that they

65

first inhabited Rhodes, and were the children of the sea; that
Neptune was committed to their care when an infant; and
that they brought him up. In other words, the Phcenician
Cabiri, or Mariners, cultivated the science of navigation.

Minos, the king of Crete, became enamoured of Brito-
martis, or Dictynna, and demanded seven youths and seven
virgins annually, from the Athenians, io be devoured by the
Minotaur ;—in plain language to work in the mines. The name
of Minos may be from mjanac a miner, or mjon just, aoy
sage. ‘The Minotaur was from mjana, mines, cojp, pursuit,
search. ‘The devouring by the monster is thus appositely
explained. Britomartis signifies Judgments of life, bpreaca
marc aojy. Dictynna—Hot, fierce fires, dajz cejna.

The Greeks invented the story of Britomartis hiding
herself in fishermen’s nets, in order to account, by a word of
a similar sound in their own language, for the name Dictynna.
This lady is said to have been born in Pheenicia, i.e. the
smelting ore by the blast or bellows was invented there; and
Minos was anxious to avail himself of this invention to
change his ore into metal, which satisfactorily accounts for
this fable.

This personage was also called Laphria, for Minos is
said to have employed her to pronounce his judgments. This
is Labpiad, speech-making, giving sentence. This fact also ac-
counts for the name of Britomartis, the judgments of life.

The initiated of the Cabiri were enjoined to the strictest
secrecy respecting the names of the great Gods. ‘The reason
of this is now obvious. Had they been known, the sources
of the wealth of the Pheenicians would have been revealed.

Sir William Betham then added a short notice of a
Hindoo Legend, from a paper in the Asiatic Researches, by
Captain Wilford, showing that the Cabiric mysteries existed
in India, under the names Cubera or Cuvera, Asyoruca,

_ Asyotcersa, Asyotchrista, Cashmala and Carmala; and that
these deities or genii superintended mining and metals.

66

Professor Mac Cullagh read a paper ‘‘ On the Chronology
of Egypt.”

In this paper the author endeavours to ascertain the
names of the Egyptian sovereigns who were contemporary
with Moses. For this purpose he finds it necessary to de-
termine the interval between two celebrated epochs—the
reign of Menes and the Exodus of the Israelites. He con-
ceives that the former epoch is fixed by the “ old chronicle”
at the distance of 443 years from the beginning of a cynic
(or canicular) cycle ; and he thinks it strange, that this sim-
ple meaning should not have occurred to chronologists, who
have universally supposed the ‘‘ cynic cycle” of the old chro-
nicle to be a series of demi-god kings who derived that ap-
pellation from the dog-headed Anubis. The canicular
cycle is a well-known period of 1460 years, which the Egyp-
tians seem to have used for computing time, as we sometimes
use the Julian period. Cne of these cycles commenced in
the year 2782, before the Christian era; and if we reckon
443 years in advance, we shall have the year B. C. 2339, for
the commencement of the reign of Menes. This date agrees
well with the computation of Josephus, who says that the
interval from Menes to Solomon was upwards of 1300 years.
Again, we are told by Clemens of Alexandria, that the
Exodus of the Israelites took place 345 years before the be-
ginning of a canicular cycle. This is evidently the cycle
which commenced B.C. 1322; and hence we have B.C.
1667 for the date of the Exodus. The interval between
Menes and the Exodus was, therefore, about 670 years.

If, now, we take the catalogue of Eratosthenes, which
commences with Menes, we shall find, at the distance of
670 years from Menes, a king named Achescus Ocaras, who
reigned only one year; preceded bya king named Apappus,
who reigned a hundred years, and succeeded by queen Ni-
tocris who reigned six years. Mr. Mac Cullagh thinks, that
Apappus is the king in whose reign Moses was born; that
Ocaras is he who pursued the Israelites to the Red Sea ;

67

and that Nitocris is the famous queen mentioned by Hero-
dotus. It may be objected, that Eratosthenes gives us the
succession of Theban kings, whereas the Pharaohs of the
Mosaic history reigned in Lower Egypt; but it is remark-
able, that the three sovereigns mentioned above are found
in Manetho’s dynasties among those who reigned at Mem-
phis; and it is singular, that these are the only sovereigns
(except Menes and his immediate successor) in which the
dynasties of Manetho and the catalogue of Eratosthenes
agree. All the other names are different. Of course, the
predecessors of Apappus, at ‘Thebes and at Memphis, were
different; and, thus, we can easily understand how there
arose up at Memphis “anew king who knew not Joseph.”
It would appear, in fact, that Apappus was of a Theban
family, and that he succeeded, for some reason or another,
to the throne of Lower Egypt. He was only six years old
(as we learn from Manetho) when he came to the throne;
and it is natural to suppose, that his chief advisers, as he
grew up, were the courtiers who accompanied the young
king from his own country to Memphis, and who knew no-
thing of Joseph, and cared nothing for his people. Accord-
ingly, when Apappus arrived at manhood, he issued an or-
der, that every male child of the Hebrews should be de-
stroyed, lest they should grow too numerous for the Egyp-
tians; and, under these circumstances, Moses was born in
the twenty-first year of his reign, and was saved by the king’s
young daughter, a girl about ten years’ old. About the
sixtieth year of Apappus, Moses was obliged to fly to the
land of Midian, for having killed an Egyptian; and when,
at length, the king of Egypt died—“after many days,” as it
is in the original—Moses returned in the beginning of the
reign of Ocaras, before whom were performed those signs
and wonders which prepared the way for the departure
of the Israelites. On the night of the Passover, the king
lost his first-born, perhaps his only son; and this may be

68

the reason that he was succeeded by his sister Nitocris. The
short reign of Ocaras (a single year) might be explained by
supposing that he was drowned in the Red Sea; but as there
is nothing in the sacred narrative which obliges us to admit
that the king perished in this manner, we may adopt the
account of Herodotus, that he was murdered by his subjects.
We may imagine that some of his nobles remained with
Pharaoh on the shore; and that when they saw the sea re-
turn and swallow up all that had gone in after the Israelites,
they murdered the king, whose obstinacy had brought such
calamities on his people, and then placed his sister Nitocris
on the throne. As Nitocris was the daughter of Apappus,
there is nothing to prevent us from supposing that the queen,
now ninety years old, was the princess who had saved the
infant Moses. Weary of her life, she lived only to avenge
her brother. For this purpose, says Herodotus, she con-
structed a large subterranean chamber, to which, when it
was finished, she invited the principal agents in her brother’s
death ; and there, by the waters of the Nile admitted through
a secret canal, they were drowned in the midst of the ban-

quet. The queen then threw herself into a room filled with
ashes, where she perished.

Mr. Petrie, by permission of Colonel Colby, read the first
part of a paper “On the Antiquities of Tara Hill,” being
a portion of the memoir written to illustrate the Ordnance
Map of Meath, now on the eve of publication.

The author first gives a detail of the mode of investiga-
tion adopted. An accurate survey and ground plan of the
locality was first procured. Translations were then made by
Mr. O’Donovan of such ancient Irish MSS. as could be
found relating to the subject of inquiry; the different copies,
where such existed, having been carefully compared so as to
obtain the greatest possible accuracy in the text. Those of
chief value, two poems and a prose tract, are compositions

69

of the tenth, eleventh, and twelfth centuries, and are con-
tained in the ancient Irish topographical work called the
Dinseanchus, copies of which are preserved in the books of
Lecan and Ballymote, in the possession of the Academy, as
also in MSS. in the College Library, and in the library of
the Duke of Buckingham at Stowe. Of the poems, one is
the composition of Cinaeth O’Hartigan, who was chief his-
torian of the northern half of Ireland, and according to the
annals of Tighernach, died in 975. The other is the work of
Cuan O’Lochain, who, according to the same authority, was
killed in 1024, having been for the two previous years, chief
poet and lawgiver of Ireland, after the dismemberment of
the monarchy in the person of Maelseachlin the Second.
The prose tract is not of equal antiquity with either of these
pieces, but is more copious in its descriptive details, and is
of a date at least prior to the twelfth century. The writer ap-
pears to have personally examined the monuments remaining
in his time, and often describes their state of preservation
with remarkable exactness.

From a comparison of the accounts given in these docu-
ments with the monuments ascertained by the survey to be
still in existence, not only all the remaining vestiges have
been identified with sufficient certainty to warrant the inser-
tion of their respective names on the map, but the localities
also of several other monuments of less importance, but
which are now wholly effaced, have been so far determined
as to furnish full materials for the construction of a ground
plan, exhibiting a restoration of the whole.

The number of these monuments, and the great extent of
ground which they cover, will be at once evident from an in-
spection of the map; and, as a striking instance of the his-
toric interest possessed by them, it may be shortly stated,
that the strongest evidence has been adduced, from MSS.
~ much more ancient than any hitherto cited on the subject, to
show that a remarkable obeliscal pillar-stone, which now

70

serves as a head-stone to the grave of the rebels who fell here
in 1798, is the so celebrated Lia Fail, or coronation stone of
the Irish kings, which has been generally supposed to have
been carried into Scotland by the Dalriadic Colony in 503,
and thence to have been taken by Edward the First into
England, where a stone alleged to be the same is, it is well
known, still shown under the coronation chair in West-
minster Abbey.

This paper proves, in a very striking manner, the value
and importance of the great national work to which it be-
longs; as, previously to the Survey, no accurate plan or de-
scription of the remarkable ruins of this remotely ancient seat
of the Irish monarchs had ever been attempted, nor any cri-
tical examination instituted with a view to the elucidation
of those Irish MS. records which bear upon the subject.

DONATIONS.

Essai Historique sur la Vie et la Doctrine d’ Ammonius
Saccas, chef d'une des plus célébres Ecoles Philosophiques
d@ Alexandrie. Par L. J. Dehant. Presented by the Royal
Academy of Brussels.

Memoire sur les propriétes et l Analyse de la Phloridzine.
Par L. de Koninck. Presented by the Royal Academy of
Brussels.

Bulletin de ? Academie Royale des Sciences et Belles-letires
de Bruxelles, for the year 1836. (Nos. 1 to 12.) Presented by
the same.

Annuaire de Academie Royale des Sciences et Belles-
lettres de Bruxelles. (Troisiéme Année.) Presented by the
same.

Sur la Latitude de UObservatoire de Bruxelles, par
A. Quetelet. Presented by the Author.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1837. No. 5.

May 8.
Rev. F. SADLEIR, D. D., F. T. C. D., Vice-President,
in the Chair.

Rev. Thomas M‘Neece, F. T. C. D., was elected member of
the Academy.

Mr. Petrie read the continuation of his paper ‘‘ Onthe
Antiquities of Tara Hill.”

Professor Lloyd read the following extract ofa letter from
Mr. Bache, President of Girard College, Philadelphia, re-
lating to a comparison of the Magnetic Intensity in Philadel-
phia, Dublin, and Edinburgh :

“ T availed myself of an opportunity afforded by Professor
Forbes, to observe the horizontal magnetic intensity at Edin-
burgh, in a locality as far from the disturbing action of the
trap rocks, on the north of the town, as was convenient. The
place (Canaan Park) adjoins that in which Mr. Dunlop’s ob-
servations were made. After correcting for rate of chrono-
meter and temperature of needle, &c. I get for Edinburgh
(Dublin being unity) 0.9592. The dip, as determined by ob-
servation of Professor Forbes, (and given in a recent paper on
the diminution of magnetic intensity at different heights,) is
71° 47’. I applied a small correction for the diminished

G

72

magnetic force of the needles, as deduced from observations
of the previous year; this may not be precise, and may
slightly change the number. The two needles gave respec-
tively :
Bar. Cylinder. . Diff.
.9576 . 9607 0031
“Taking your result for Dublin and London, and Captain
Sabine’s for London and Paris, I deduce for the ratio of
Edinburgh and Paris, (the latter being unity) 0.8406,—which
is nearly identical with the direct comparison made by Pro-
fessor Forbes. It disagrees very materially with the result
of Captain Hall, by whom Edinburgh and London were first
compared ; but as the locality of his observations was shown
by Mr. Dunlop to have rendered them inaccurate, they can-
not be said to make against these determinations. I have
not yet had an opportunity to see how far Mr. Dunlop’s
correction would make the three sets coincide.
“* My determinations give:

Philadelphia, . . . 1.0000

Dublin, (Fe | * S300

Edinburgh,. . . . 0.7957
But, of course, the correction for the loss of magnetism
by the needle, if not exact, would affect these results more
than that for the two last named places.”

DONATIONS.

Flora Batava, No. 109. By H. C. Van Hall. Presented
by the Author.

A Copy of the Ordnance Survey of the County of Meath,
in 55 sheets. Presented by Lieutenant-Colonel Colby.

On the Arenarius of Archimedes. By Stephen Peter
Rigaud, M.A., Savilian Professor of Astronomy, Oxford.
Presented by the Author.

Mean Heights of the Barometer and Thermometer, with the
Fall of Rain, at the Observatory, Oxford, during each month
of the years 1828 to 1836. Presented by the same.

al

as

May 22.

Rey. B. LLOYD, D.D., Provost, T. C. D., President,
in the Chair.

Rey. James Horner, D. D., was elected member of the
Academy.

Professor Mac Cullagh read a letter from Joseph S.
Moore, Esq. on the Australian instrument called Ailee or
boomerang, so remarkable for the course that it takes when
thrown in the air. It is a flat piece of wood of a hyperbolic
form, about 23 inches broad, perfectly plane on one side,
and slightly convex on the other. A right line joining its
extremities is about two feet long, and the middle of this
right line is distant about a foot from the middle of the in-
strument or the vertex of the hyperbola. When properly
thrown, it makes a circuit, returns, passes close to the per-
son who threw it, and even goes behind him, and then at-
tempts to return again before it falls to the ground. It is
curious that such a missile should have been invented by
savages, for, as far as we know, it is found only among the
natives of New Holland. It is said to be called ké/ee on the
western, and boomerang on the eastern coast of that country.
Some of these kilees had been sent to Mr. Moore from the
Swan River, and though he was unsuccessful in throwing
them, he succeeded with others which he caused to be made
of the same general form, but much more curved than the
originals. ‘The dimensions given above are those which he
found most convenient. The following is an extract from
Mr. Moore’s letter :

« The natives throw them with the convex edge against
the air; their movement is then from left to right. But the
way in which I have succeeded was by taking the missile by

74

one end, with the concave edge inward, and the plane side
undermost, the plane making an angle of about forty degrees
with the horizon; throwing as if to strike the ground at the
distance of about thirty yards, and giving it, on leaving the
hand, a rapid rotatory as well as progressive motion. In-
stead of striking the ground at which it was aimed, its plane
becomes horizontal at the distance of twenty-five yards, and
so continues for about fifteen yards, when it commences
rising in the air, and moving towards the left ; its plane then
becomes inclined, and continues at an angle of from thirty to
forty degrees, whilst it describes apparently a segment of a
circle to the left. Having, at the distance of sixty or seventy
yards, attained an altitude of from forty to sixty feet, the pro-
jectile returns, descending to the point from which it was
projected, when its plane becoming once more horizontal, it
skims along within a few feet of the ground, and passes close
by the right hand of the person who threw it. On passing,
its plane becomes elevated once more, it rises a second time,
and performs another smaller curve, (fifteen or twenty yards
behind the projector,) in like manner as the first, with this
singular exception, that the second curve is described from
left to right, contrary to the course of its rotation and of the
first curve, which is invariably from right to left.”

In bringing the instrument under the notice of the Aca-
demy, Mr. MacCullagh wished to draw attention to the
theory of its motion. When a body of any form whatsoever
is projected in vacuo, we know that its centre of gravity
must describe a parabola in a vertical plane, while the body
spins about an axis passing through that centre. In the pre-
sent case, therefore, itis clear that the continued swerving from
the vertical plane must be ascribed to the action of the air.
But to compute accurately the mutual action of the air, and
of a body endued, at the same time, with a progressive and
a rotatory motion, is a problem far beyond the present powers
of science. The problem can only be solved approximately ;

15

and, however we may simplify it, the calculations are likely
to be very troublesome. Even the suppositicn of a resist-
ance proportional to the square of the velocity (which is
usually considered as an approximation in questions of this
sort), would lead to complicated results. It may be ob-
served, that the motion of the filce is rudely imitated in
the familiar experiment with a card, cut into the form of
a crescent, and sent off by a fillip, so as to spin in its own
plane.

Mr. Petrie read the concluding portion of his paper ‘‘ On
the Antiquities of Tara Hill.”

In this, as well as in the preceding part, the author has
endeavoured to ascertain from historic evidences, not only
the period to which each of the monuments now remaining
should be referred, but also the date of those of which no
vestiges exist, but whose features and localities are described,
in ancient documents. In this investigation, the author
brought forward a great number of ancient Irish authorities
not hitherto used or translated, of which one of the most
curious and interesting is a description of the banqueting
hall or house of assembly, written by Cinaeth O’Hartigan,
a celebrated poet of the tenth century. From all these docu-
ments it appears, that, with the exception of the original
Tuatha Dedanann cahir, and coronation stone, all the monu-
ments now or formerly existing on Tara Hill may be classed
under two distinct eras, both within the limit of authentic Irish
history. The first and less important class comprises the monu-
ments belonging to the age of the hero Cuchullin, who died in
the early part of the first century ; and of these there are no
remains. The second—to which nearly all the existing monu-
ments belong—extends to the time of the monarch Cormac
Mac Art, in the third century. There are only two or three
monuments of later date. From these facts, the author con-
cludes, that, before the latter period, Tara had attained to

76

no distinguished celebrity as a regal city; and hence its
omission from the map of Ptolemy, who wrote in the century
preceding.

Another fact, derived both from historic evidences and
existing remains, is, that, with the exception of the cahir
erected by the Tuatha Dedananns, all the works appear to
have been of earth and wood; though forts and houses of
uncemented stones are found in other districts of equally
ancient or even earlier date. From the uniform character
which pervades these remains, the author concludes that
they are the monuments’ of one people; and he thinks that
the fact above mentioned may help to elucidate the origin
of that Scotic race, which ruled in Ireland at the period of

their construction.

Sir William Hamilton laid before the Academy an ac-
count of some investigations, in which he had recently been
engaged, respecting Equations of the Fifth Degree. They
related chiefly to three points: first, the argument of Abel
against the possibility of generally and algebraically resolving
such equations; second, the researches of Mr. Jerrard; and
third, the conceivable reduction, in a new way, of the original
problem to a more simple form.

1. The argument of Abel consisted .of two principal
parts; one independent of the degree of the equation, and
the other dependent on that degree. The general principle
was first laid down, by him, that whatever may be the degree
n of any general algebraic equation, if it be possible to ex-
press a root of that equation, in terms of the coefficients, by
any finite combination of rational functions, and of radicals
with prime exponents, then every radical in such an. expres-
sion, when reduced to its most simple form, must be equal
to a rational (though not a symmetric) function of the roots
of the original equation; and must, when considered as ‘such
a function, have exactly as many values, arising from the

77

permutation of those n roots among themselves, as it has
values, when considered as a radical, arising from the intro-
duction of factors which are roots of unity. And in pro-
ceeding to apply this general principle to equations of the
fifth degree, the same illustrious mathematician employed
certain properties of functions of five variables, which may
be condensed into the two following theorems: that, if a
rational function of five independent variables have a prime
power symmetric, without being symmetric itself, it must be
the square root of the product of the ten squares of diffe-
rences of the five variables, or at least that square root mul-
tiplied by some symmetric function; and that, if a rational
function of the same variables have, itself, more than two
values, its square, its cube, and its fifth power have, each,
more than two values also. Sir W. H. conceived that the
reflections into which he had been led, were adapted to re-
move some obscurities and doubts which might remain upon
the mind of a reader of Abel’s argument; he hoped also
that he- had thrown light upon this argument in a new way,
by employing its premisses to deduce, d priori, the known
solutions of quadratic, cubic; and biquadratic equations,
and to show that no new solutions of such equations, with
radicals essentially different from those at present used, re-
main to be discovered : but whether or no he had himself
been useful in this way, he considered Abel’s result as esta-
blished : namely, that it is impossible to express a root of
the general equation of the fifth degree, in terms of the co-
efficients of that equation, by any finite combination of radi-
cals and rational functions.

2. What appeared to him the fallacy in Mr. Jerrard’s very
ingenious attempt to accomplish this impossible object, had
been already laid before the British Association at Bristol,
and was to appear in the forthcoming volume of the reports of
that. Association. Meanwhile, Sir William Hamilton was
anxious to state to the Academy his full conviction, founded

78

both on theoretical reasoning and on actual experiment, that
Mr. Jerrard’s method was adequate to achieve an almost
equally curious and unexpected transformation, namely, the
reduction of the general equation of the fifth degree, with
five coefficients, real or imaginary, to a trinomial form; and
therefore ultimately to that very simple state, in which the
sum of an unknown number, (real or imaginary), and of its
own fifth power, is equalled to a known (real or imaginary)
number. In this manner, the general dependence of the
modulus and amplitude of a root of the general equation of
the fifth degree, on the five moduli and five amplitudes of
the five coefficients of that equation, is reduced to the de-
pendence of the modulus and amplitude of a new (teal or
imaginary) number on the one modulus and one amplitude
of the sum of that number and its own fifth power; a reduc-
tion which Sir William Hamilton regards as very remarkable
in theory, and as not unimportant in practice, since it reduces
the solution of any proposed numerical equation of the fifth
degree, even with imaginary coefficients, to the employment,
without tentation, of the known logarithmic tables, and of
two new tables of double entry, which he has kad the curio-
sity to construct and to apply.

3. It appears possible enough, that this transformation,
deduced from Mr. Jerrard’s principles, conducts to the
simplest of all forms under which the general equation of
the fifth degree can be put; yet, Sir William Hamilton
thinks, that algebraists ought not absolutely to despair of
discovering some new transformation, which shall conduct
to a method of solution more analogous to the known ways
of resolving equations of lower degrees, though not, like
them, dependent entirely upon radicals. He inquires in what
sense it is true, that the general equation of the fifth degree
would be resolved, if, contrary to the theory of Abel, it
were possible to discover, as Mr. Jerrard and others have
sought to do, a reduction of that general equation to the

a7

binomial form, or to the extraction ofa fifth root of an ex-
pression in general imaginary! And he conceives, that the
propriety of considering such extraction as an admitted in-
strument of calculation in elementary algebra, is ultimately
founded on this: that the two real equations,
2 —10a%y?+5ay' =a,
5aty—l0a?y?+y?=),
into which the imaginary equation
(e+ v —1y)* —a+Vv—1b
resolves itself, may be transformed into two others which are
of the forms
57—10 7 nas

ea ae

p°’ =f, and Up

so that each of these two new equations expresses one given
real number as a known rational function of one sought real
number. But, notwithstanding the interest which attaches
to these two particular forms of rational functions, and ge-
nerally to the analogous forms which present themselves in
separating the real and imaginary parts of a radical of the
n degree; Sir William Hamilton does not conceive that
they both possess so eminent a prerogative of simplicity as to
entitle the inverses of them alone to be admitted among the
instruments of elementary algebra, to the exclusion of the
inverses of all other real and rational functions of single real
variables. And he thinks, that since Mr. Jerrard has suc-
ceeded in reducing the general equation of the fifth degree,
with five imaginary coefficients, to the trinomial form above
described, which resolves itself into the two real equations
following,

2— 10a y?+5zry'+r=4,
5a*y—102? y>+y?+y=),
it ought now to be the object of those who interest them-

selves in the improvement of this part of algebra, to inquire,
H

80

whether the dependence of the two real numbers « and y, in
these two last equations, on the two real numbers a and 3},
cannot be expressed by the help of the real inverses of some
new real and rational or even transcendental functions of
single real variables; or, (to express the same thing in a
practical, or in a geometrical form,) to inquire whether the
two sought real numbers cannot be calculated by a finite
number of tables of single entry, or constructed by the help
of a finite number of curves: although the argument of Abel
excludes all hope that this can be accomplished, if we con-
fine ourselves to those particular forms of rational functions
which are connected with the extraction of radicals.

DONATIONS.

Voices from the Time of the Reformation of the Danish
Church. (In Danish.) Presented by the Literary Society of
the Diocese of Funen. 7

Observations on some of the Strata between the Chalk and
Oxford Oolite, in the South-East of England. By William
Henry Fitton, M.D., F.R.S., &c. Presented by the Author.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1837. No. 6.

June 12.

Rey. B. LLOYD, D.D., Provost, T. C. D., President,
in the Chair.

A PAPER was read, entitled, ‘An Inquiry into the Pos-
sibility of transplanting the Cornea, with the view of reliev-
ing Blindness occasioned by Diseases of that Structure.”
By Samuel Lenox Bigger, Esq.

The author stated that his expectation of succeeding in
this operation had been first raised by the partial success
attending an attempt which he had made, while a prisoner
with a nomadic tribe of Arabs,—the subject of the operation
being a gazelle. Having been thus led to inquire what had
been done elsewhere to relieve or cure the opaque state of
the cornea, Mr. Bigger found that the idea of performing the
operation of transplantation had been entertained in Ger-
many alone; that experiments had been made in that
country, by Moesner, Reisinger, Schon, Drolshagen, Dief-
fenbach, and Thomé, with various results ; but that Wutzer
was the only person whose belief in the possibility of the
operation led him to attempt it on the human subject,—an
attempt in which he was unsuccessful, owing to the resist-
ance of his patient.

The author then described the plan of operation which

I

82

he had found most successful, and which had been hitherto
untried. The results of several experiments performed ac-
cording to this plan were then read. In a series of eighteen
experiments, the iris was injured in ten; the crystalline lens
escaped in eleven; union took place between the implanted
portion and the adjacent parts in seventeen, in the space of
forty-eight hours; in twelve, adhesion of the iris took place
to some part of the cicatrix; sixteen were restored to imper-
fect vision ; and in one, slough of the lambeau, and consequent
destruction of the eye, occurred, the portion of cornea to be
inserted having been detained half an hour before it was
attached, in order to try how long it would retain vitality
sufficient to enable it again to take on a vital action.

The author made several experiments with iodine, nitrate
of silver, &c., and found that they were incapable of pro-
ducing any effect on the milky state of the cornea, although
they appeared to diminish the extent of the cicatrix ; cor-
rosive sublimate (in the proportion of from half a grain to
three grains to the ounce of water) was the only medicinal
substance tried which had the power of restoring absolute
clearness to the implanted portion.

The anthor then mentioned the various means he had
employed to produce absorption of the cicatrix, with their
results ; explained his view of the cases in which this opera-
tion might be attempted; and concluded by entreating
those surgeons, who possessed hospitals, not to be too hasty
in rejecting an operation, which, from the experiments de-
tailed, and the living subjects exhibited, was. now proved
to be at least possible.

Mr. Bigger then made an oral communication on a series
of experiments in which he was at present engaged, con-
nected with the operations detailed in his paper.- The
object of these experiments was the removal of small spots
of opaque lymph, where they existed in the centre of the
cornea. ‘The method employed consisted in passing a liga-

83

ture through the opaque spot with a curved needle, which
serves to fix the eye. Another needle is then passed at
right angles to the former, and armed with a very fine liga-
ture, which is allowed to remain loose. The first liga-
ture being then strained; an incision is made equal in
length to the nebulous portion; then raising it by the ligature,
the whole opaque portion may be removed with a sharp
curved scissors, and by drawing the ligature of reserve, the
two fresh incised surfaces brought together.

Professor Kane read a paper “ on the Composition of
certain essential Oils.”

The first object of the author, in commencing the exami-
nation of this subject, was to collect facts towards an ap-
proximate solution of the problem, “‘ whether there can be
found any law connecting the composition of the secretions of
plants of the same genus or natural family.” The three
alcaloids of the genus cinchona, giving the formule

R+0,R+20,R+350,

appear to furnish a glaring instance of the existence of such
a law; but the want of connexion in the composition of the
constituents of opium might be advanced in opposition,
although not quite a parallel case. The family of the
coniferze appear well characterized by the presence of the
hydrocarbon c,4, and its oxides; but the same composition
is found prevailing among the aurantiz, as in oil of lemons,
—the myrti, as in the neutral oil of cloves,—and the lauri,
as in common camphor ; whilst other members of the same
family, as oil of cinnamon, have formule altogether dif-
ferent.

The members of the family of the labiate are characte-
rized by yielding remarkably aromatic oils by distillation ;
and as many of these oils, from their use in medicine, are

12

84

easily procured in commerce, Professor Kane considered
that the determination of the composition of the products of
certain members of a botanical group, whose natural con-
nexion is among the best marked, might tend to throw some
light upon the question at issue. He, therefore, examined
the oils of the origanum vulgare, lavandula spica, mentha
piperita, mentha puleghium, and mentha sativa. Great diffi-
culty was found in obtaining the specimens so absolutely
pure as to fit them for analysis, as all such oils contain small
quantities of solid matters, (camphors of the essential oils,
stearoptens,) which render impure the later products of the
rectification.

Repeated analyses of the oil of the mentha puleghium,
gave for its composition the same formula as for oil of tur-
pentine, or oil of lemons, that is c,u,, or per cent.

Theory. Experiment.
Carbon = 88,45 — 88,56
Hydrogen = 11,55 — 11,87

Its boiling point is about 314° F., the same as that of tur-
pentine.

The oil of mentha sativa, boiling at 320° F., gave, by
several accordant analyses, the formula,

Cz,H,,0 or 7{c,H,}-+0, and per cent.
Theory. Experiment.
Carbon = 85,67 — 83,66
Hydrogen = 11,15 — 11,38
Oxygen = 3,18 — 2,96
The oil of the origanum vulgare, boiling at 324° F., gave
as the result of five analyses, which varied very little from

one another, the formula,

C5) H,,0 or 10{c,u,}+-0, and per cent.

85

Theory. Experiment.

Carbon = 86,48 — 86,33
Hydrogen = 11,27 — 11,44
Oxygen = 2,25 —_ 2,23

These three oils, therefore, have the same hydrogen and
carbon, and differ only in the two latter having absorbed
small, but perfectly definite quantities of oxygen.
Oil of the lavendula spica, boiling at 365° F., gave as
result, the formula cj, 4,,0, or per cent.
Theory. Experiment.

Carbon = 80,35 — 79,45

Hydrogen = 10,90 — 11,30

Oxygen = 8,75 — 9,25

The oil of peppermint had been analyzed by Blanchet

and Sell, who obtained results, giving the formula c,,4,,0,
which has been found above for oil of lavender. As their
analyses were only two in number, and are given in the
Journal de Pharmacie without any explanatory detail, Pro-
fessor Kane thought it not superfluous to add to the above
experiments a confirmation of their results. On purifying oil
of peppermint of commerce, (having selected the foreign oil
that it might be more probably what they had examined,)
Professor Kane found that the more it was rectified and the
earlier condensed the specimens analyzed were, the more
the boiling point approached to 314°, and the composi-
tion to the formula c,u, The difference between this
result and that of Blanchet and Sell is too great to be ex-
plained by an error in the analyses of chemists whose other
labours have shown such accuracy in quantitative research :
Professor Kane accordingly thinks it not improbable, that
there are two oils of peppermint of different compositions,
and he is now occupied in seeking amongst the commercial
samples for that with which the other chemists had been
engaged.

86

Since the paper of which the preceding is an abstract
was read, Professor Kane has examined the English oil of
peppermint, which, when pure, has a density of 0,899, and
boils at 865°. Its composition is

C,,H,,0, or 5{c,H,}-+-H,0, and per cent.

Experiment. Theory.
Carbon = 80,14 — 80,15
Hydrogen= 11,76 — nase 100.
Oxygen = 8,10 — 8,37

This formula differs from Blanchet’s in the hydrogen, which
Blanchet’s formula makes 10,9.

Oil of rosemary has been likewise examined, its density
is 0,85, and it boils at 832°. It gave the formula,

Cy, Hj, 0,=9{c,H,} +H,0, and per cent.

Experiment. Theory.
Carbon = 83,49 — 83,73
Hydrogen= 11,66 — 11,5] 100,00.
Oxygen = 4,85 — 4,86

The foreign oil of peppermint Professor Kane considers
to be a mixture of nearly equal parts of genuine oil and of |
oil of turpentine; and hence the results obtained in its ana-
lysis as detailed above.

A paper ‘‘on Atmospheric Electricity” was then read
by Edward S. Clarke, Esq.

The author having lately erected, at his residence near
Palmerston, an apparatus adapted to observations on this
subject, he exhibited to the Academy a drawing of the in-
strument. He stated, that in bringing the subject under
the notice of the Academy, he had two objects in view,—
the first, to compare the results of his experiments with
those previously obtained by other observers; and the se-
cond, to induce others to erect similar instruments, feeling

87

assured that contemporaneous ecbservations would throw
much light upon the subject.

The more important results obtained by Mr. Clarke dur-
ing the past two months are :

lst: That atmospheric electricity in serene weather is
invariably positive.

2nd. That it is more intense during fogs, especially if
they occur during frosty weather.

ord. That in cloudy weather, (without rain,) the aerial
electricity diminishes in intensity.

4th. That during heavy rain, hail, snow, or sleet, (and
particularly at their commencement,) the atmospheric elec-
tricity is very intense. This electricity is, at first, invariably
negative, but sometimes changes its state frequently during
the storm.

5th. That the periods of its diurnal changes of intensity
vary considerably, the intensity being at a maximum (during
the past two months) each day some time between 73, A. M.,
and 103, a.m. ; becoming almost evanescent at noon; and as-
cending progressively for a few hours previous to sun-set.
It acquires its nocturnal maximum some time between 9 and
12, p. M.; when it again declines gradually until some hours
after sun-rise.

6th. That the nocturnal electricity, with or without dew,
is stronger than the diurnal.

The foregoing observations are for the most part con-
firmed by those of Cavallo. But, the sixth observation does
not agree with those of Canton, Abbé Mazeas, M. De
Saussure, and Mr. Cross; the two former observers not
having observed any electricity at night, and the two latter
finding it weaker than by day. M. De Saussure conceived
the electricity of the evening to be strong in consequence of
the dew acting as a conductor,. whilst the author has ob-
served it very strong when there was no dew. M. De Saus-
sure has likewise stated the maximum of diurnal electricity

88

to occur some hours after noon, it being also strong at noon;
whilst Mr. Clarke usually found it almost evanescent at that
period. These differences, the author conceives, may arise
from difference of climate, or imperfect insulation of the
instruments.

Mr. Clarke believes the electric intensity exhibited by
the various clouds to be in the following order:

The nimbus, the cumulo-stratus, the cumulus, the stratus,
the cirro-stratus, the cirro-cumulus, and the cirrus.

DONATIONS.
Asiatic Researches, Vol. XIX. Part 1. Presented by
the Asiatic Society.

The London Medical and Surgical Journal, for Apvril,
1837. Presented by the Editor.

June 26.

- Rev. B. LLOYD, D.D., Provost, T. C. D., President,
in the Chair.

Matthew O’Conor, Esq., was elected member of the
Academy.

Professor Liebig, of Giessen, was elected honorary
member of the Academy.

A paper was read, “on a new Gaseous Compound of
Carbon and Hydrogen.” By Edmund Davy, Esq., F.R.S.
&c., Professor of Chemistry in the Royal Dublin Society.

This compound was procured by the action of water on
a black substance obtained by exposing a mixture of cream
of tartar and charcoal powder to a strong heat in an iron
bottle. The gas is highly inflammable, and when kindled
in contact with air, it burns with a bright white flame, ap-
parently denser and of greater splendour than even olefiant

89

gas. It forms with oxygen a powerfully explosive mixture,
when the volume of the latter is to that of the former, as
three or four to one. The new gas explodes spontaneously
when brought in contact with chlorine gas; and this effect
is accompanied with the production of flame, and the copious
deposition of carbon: and is quite independent of the action
of light, or the sun’s rays, as it readily takes place in the
dark. Under the ordinary pressure of the atmosphere,
water absorbs about its own bulk of the gas, which is again
liberated by heat, apparently unaltered.

According to Professor Davy’s experiments, the new gas
consists of a volume of hydrogen gas and two volumes of
the vapour of carbon condensed into one volume; and it
requires for its complete combustion two and a half volumes
of oxygen gas. Its specific gravity is 0.917, that of common
air being 1.000. 100 cubic inches of it weigh 28.4378 grains.

The equivalent of the new gas appears to be 13.24, and
the formula by which it is expressed is 2c+H, or c?-+-H.
The name proposed for it is bicarburet of hydrogen, which
simply expresses its chemical constitution.

A paper by Professor Mac Cullagh, ‘ on the Properties
of Surfaces of the second Order,” was read.

Among various other matters, this paper contains a new
class of properties which are analogous to the focal proper-
ties of the conic sections. The author has found that sur-
faces of the second order may be generated by means of a
given point as focus, a given right line as directrix, and a
given plane. In general, every such surface is the locus of
a point, whose distance from the focus bears a given ratio to
its distance from the directrix, the latter distance being
measured parallel to the given plane. This mode of gene-
ration, however, excludes surfaces of revolution about the
major axis, as the corresponding generation of the conic
sections excludes the circle. When the given ratio is not

90

one of equality, the surface has circular sections parallel to
the given plane; when it is a ratio of equality, we get the
hyperbolic paraboloid. All other things remaining the same,
the focus and directrix may be changed without changing
the surface described. If we confine ourselves to the cen-
tral surfaces, the locus of the foci fora’ given surface will be
an ellipse, which may be called the focal ellipse, each focus
having a corresponding directrix perpendicular to the plane
of this ellipse.

If the focal ellipse be made the base of a cone, whose
vertex is at any point v on the surface, the normal at this
point will be one of the principal axes of the cone. But,
as three surfaces, confocal to each other, and therefore
having the same focal ellipse, may be described through a
given point, if we suppose two other such surfaces to pass
through the point v, the normals to these surfaces will be
the other two principal axes of the cone. And if a system
of surfaces, confocal to these three, be circumscribed by
cones having a common vertex at v, the principal axes of
all these cones will be the same as those of the cone which
has the focal ellipse for its bases Indeed, the focal ellipse
(which lies in the plane of the greatest and the middle axes
of the ellipsoids) may, in the confocal system, be considered
as the limit between the ellipsoids and the hyperboloids of
one sheet. There is also, in the plane of the greatest and
least axes of the ellipsoids, a focal hyperbola which is the
limit between the confocal hyperboloids of one and of two
sheets ; and of course, the cone which has this hyperbola
for its base, and v for its vertex, has the same principal
axes as the cones already mentioned. Right lines which
pass, at the same time, through the focal ellipse and the
focal hyperbola, possess remarkable properties.

The foregomg are the leading propositions in Mr.
Mac Cullagh’s paper. There are besides many particular
theorems which could not be noticed within the compass of
an abstract.

91

Mr. Graves, Fellow of Trinity College, mentioned the fol-
lowing theorem of his own, relative to confocal surfaces :—

“If there be two confocal surfaces of the second order,
one of which is circumscribed by. a cone whose plane of
contact touches the other surface in a certain point, the
normal at this point will pass through the vertex of the cone.”

A new rain-gauge was exhibited to the Academy, con-
trived by the Rev. Thomas Knox.

The object of this instrument is to register the amount
of rain that falls when the wind is in different points. Its
construction is very simple. The water,—instead of descend-
ing from the reservoir directly into the tube of registry,—
passes through a lateral tube into an annular-shaped vessel,
divided into eight compartments, each..of which terminates
below in a graduated glass tube. It is obvious, then, that
if the eight tubes be set to correspond with the cardinal and
intermediate points, and that the reservoir be made to re-
volve on a vertical axis by means of a vane, the direction of
which corresponds with that of the lateral tube, the object
proposed will be attained. Mr. Knox has preferred to make
the reservoir fixed, and the system of tubes moveable; but
the result is obviously the same.

The Academy then proceeded to consider the amend-
ments of the by-laws, proposed by the Council; and, after
some discussion, it was resolved that there be an adjourned
meeting at two o’clock, on Friday the 30th of June, for the
further consideration of the subject.

DONATIONS.

A Copy of the Ordnance Survey of the County of Lei-
trim, in 40 sheets. Presented.by Lieutenant-Colonel Colby.

Proceedings and Ordinances of the Privy Council of Eng-
land, Vols. VI. and VII. Presented by the Commissioners
of the Public Records.

92

The ancient Kalendars and Indentaries of the Treasury
of his Majesty's Exchequer, 3 Vols. Presented by the same.

Excerpta é Rotulis Fintum in Turri Londinensi asservatis,
Henrico Tertio Rege, A. D. 1216—1272. Cura Caroli Ro-
berts. Vol. I. A. D. 1246—1272. Presented by the same.

A Brief Description of the Etruscan and Greek Antiqui-
ties, now exhibited at No. 121, Pall Mall. Presented by
Sir William Betham.

An Address to Astronomical Observers, relative to the Im-
provement and Extension of the Astronomical Society's Cata-
logue of 2881 principal Stars. Presented by Francis Baily,
Esq.

On the Atmospheric Tides and Meteorology of Dukhun.
By Lieutenant-Colonel W. H. Sykes, F.R.S., &c. &c.
Presented by the Author.

The same Author presented also the following papers to
the Academy :

On the Geology of a portion of Dukhun, East Indies.

On the Quails and Hemipodii of India.

On the Increase of Wealth and Expenditure in the various
Classes of Society in the United Kingdom, as indicated by
the Returns made to the Tax-office, Exports and Imports,
Savings Banks, §c. §c.

Description of the Wild Dog of the Western Chats.

Some Account of the Kolisurra Silk-worm of the Deccan.

Remarks on the Identity of the Personal Ornaments sculp-
tured on some Figures in the Buddha Cave Temples at Carli,
with those worn by the Brinjaris.

Land Tenures of Dukhun, Parts 1 and 2.

A Catalogue of the Mammalia and Birds observed in
Dukhun, East Indies.

Abstract of the Statistics of Dukhun, (Deccan,) 1827-28.

Description of a new Species of Indian Ants.

Remarks on the Origin of the popular Belief in the Upas,
or Poison Tree of Java.

June 30, (Adjourned Meeting.)

Rev. B. LLOYD, D.D., Provost, T.C.D., President,
in the Chair.

The Academy resumed the consideration of the Amend-
ments in the By-laws, proposed by the Council.

The following laws and amendments were agreed to at
this and at the preceding meeting.

Chap. II. for section 3, substitute the following:

“‘ No balloting for members shall take place except on the
second Monday in the month. The names of the candi-
dates, with the names of the proposer and seconders, shall
be read out by the Secretaries immediately previous to the
ballot.”

In section 6, add, “the names of candidates proposed,
with the names of the proposer and seconders, shall be read
out by the secretaries on the evening of their proposal. ‘The
names to remain a month on the books.”

In section 9, omit the words “ or of the council ;” and in-
troduce the words, “in the face of the Academy,” after the
word ‘ Charter-Book.”

Chap. III. at end, introduce the words, “ and shall have
discharged all arrears due,” after the word “‘ Academy.”

Chap. IV. section 3, the second in the order of Pro-
ceedings shall be “ admission of new members ;” and the
eighth, “ names of candidates proposed read.”

Introduce, as section 4, the following by-laws :

«* All papers shall be read in the order in which permis-
sion shall have been granted by the council,—with this ex-
ception: that if any paper be withheld during the entire even-
ing, it shall not be read but in such order as the council
shall determine.”

‘* No new paper shall be commenced after 10 o'clock.
The time to be occupied in the reading of any one paper

94

each night of meeting shall not exceed half an hour, except
by a vote of the Academy; it being understood, that if a
paper be not finished in one evening, it shall have prece-
dence on the succeeding night.”

Chap. V. section 2, to be altered as follows:

** There shall be two secretaries—of the Academy and of
the council,—who shall attend all the meetings of the Aca-
demy and council, and to each of whom shall be paid a
salary of twenty guineas per annum.”

Section 3 repealed, and the following substituted :

‘“‘'There shall also be a secretary of foreign correspon-
dence.”

Section 4 to be altered as follows:

‘“* There shall also be a treasurer, (to whom a salary of
twenty guineas per annum shall be paid,) who shall attend
each night of meeting.”

Section 5 to be altered as follows :

“* A clerk and assistant librarian shall be elected annu-
ally, who shall not be a member of the Academy, and whose
duty shall be, &c.”

Chap. VI. section 5, repealed.

Chap. VII. section 1, to be altered as follows:

‘The member who proposes any member for admission
shall, previous to the ballot, deposit in the hands of the
treasurer to the Academy the sum of five guineas, as admission
fee of such person; ‘said sum to be returned in case of re-
jection.”

Section 2 to be altered as follows :

“‘ Every member, besides his admission fee, shall pay the
sum of two guineas annually, becoming due on the 16th of
March next after the admission of such member,—except his
election shall have taken place between the Ist of January
and the 16th of March, in which case his first annual sub-
scription will not become due until the 16th of March in the
year following.”

95

Section 4, the following words to be added :

** Any member may compound for future annual pay-
ments by paying the sum of twenty guineas at one payment ;
but any member,” &c.

Chap. VIII.—Section 1 to be altered as follows:

** The key of the library shall be entrusted to no person
but the librarian or assistant librarian, one of whom shall be
always present during library hours.

Section 2, to be altered as follows:

“* The library shall be open every day, Sundays ex-
cepted, throughout the year, (except during Christmas week,
Passion week, and the month of August,) from eleven A. M.,
to four Pp. M.”

Section 3 repealed.

Section 6 repealed.

Section 7 to be altered as follows :

“That members have the privilege of borrowing books
from the library, with certain after-mentioned exceptions ;
and that the sub-librarian, before lending any book or
books, must,” &c.

The following sections to be added :

Section 9.—* No member who is in arrear shall on any
account be allowed the use of the library; and for the better
carrying such law into effect, the names of such defaulters
shall be hung up in the library.”

Section 10.—‘‘ That no manuscript be lent, without the
special permission of the council. That the same rule be
extended to rare and expensive works, (to be marked with an
asterisk in the printed catalogue,) as also to dictionaries and
encyclopedias.”

Section 11.—** That the sub-librarian be desired to exa-
mine the state of the books lent, upon their delivery and
return.

Chap. IX.—Sections 4, 6, 7, and 8, repealed.

Section 12, the commencement to be altered as follows :

96

* That medals be given each year for the best Essays in
some proposed principal subject, or branch of science, polite
literature, or antiquities, which shall be read, &c.”

And at the end, the following clause to be added, ‘‘ The
council shall also have the power of awarding medals for

the best Essays read during the year.”
The following chapter to be added to the by-laws :—

“S

“ Of the Committee of Publication :

**], A committee shall be formed, corresponding to the
committee of publication of the Royal Society.

“92. The committee shall consist of seven members ;
three from the committee of science, and two from each of
the other committees.

«3. It shall be the duty of this committee—

‘1. Toreport to council on all papers offered for pub-
lication in the Transactions.

“*2, To superintend the final correction of the press,
and to see that the printing and engraving are executed
in a manner creditable to the Academy.

‘**3. To arrange all details connected with the printing
and publication of the Transactions and Proceedings of
the Academy.

“4, The committee shall have liberty to call in any
member of the council or Academy to assist them in reading
or judging of any paper.”

The Academy then adjourned to the second Monday in
November.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1837, No. 7.

November 13.

Rev. B. LLOYD, D. D., Provost, T. C. D., President,
in the Chair.

Rosert Suaw, Esq., Bushy Park, was elected an ordinary,
and Captain W. H. Smith, an honorary member of the
Academy.

Rev. Dr. Wall, Senior Fellow of Trinity College, read a
paper on the “ Original State of the Text of the Hebrew
Bible, and on the Nature, Age, and Origin of the Sanscrit
Writing and Language;” but he only touched upon the
first subject as far as was necessary for the introduction of
the second.

All the letters of the Hebrew text, in its original state,
were employed as signs of syllables, beginning with conso-
nants, and ending with vowels. The vowel part of every
syllable being variable, it was left to the judgment of the
reader to determine, for each place of the occurrence of a
letter, the vowel which his knowledge of the language
showed him was required by the context. Even still, near
four-fifths of the vowels must, in reading the présent un-
pointed text, be supplied in a similar manner; the only dif-
ference being, that they are no longer considered to be
included in what the letters express, the powers of those

K

98

letters having been decomposed, in consequence of which
they are now used as consonants. The remaining portion
of the text at present, indeed, exhibits signs for the vowel
as well as the consonantal ingredients of the syllables, three
of the letters, namely, haleph, yod, and waw, being occasion-
ally diverted from their original use to the purpose of vocal
designation, the first of them with the power of A; the se-
cond, as E or I; and the third, as O or U; but where they
are now, or rather where they formerly were so employed,
(for in many places of the Hebrew text, characters are at
present considered as vowel-letters, where the Greek ren-
dering of the proper names clearly shows that they could not
have been read as such at the time when the Septuagint
translation was framed,) they constitute no part of the origi-
nal writing, and were introduced into it by the Jews, after
the Greek version had made them but very slightly ac-
quainted with the value of such signs. Had they previously
become more familiar with the subject, they would of course
have adopted at least five vowel-letters instead of three, and
they would have vocalized the whole of the text, instead of
only about one-fifth part of it. But however imperfectly and
irregularly this vocalization was made,—and the very im-
perfection and irregularity which are observable in it, now
contribute to the proof of its human origin ;—still at the time
of its insertion it was a most providential addition to the sa-
cred text, to preserve the true meaning of the word of God ;
an object which in most, though by no means in all instances,
it has certainly effected.

The correctness of this statement respecting the adven-
titious nature of the Hebrew vowel-letters, is proved by the
very large proportion of the discrepancies between the He-
brew text and Septuagint version, which can be removed by
a different insertion of those letters in the original: and the
proof thus supplied is confirmed by the Samaritan Penta-
teuch, in which, indeed, it is the same set of letters that are

99

employed as vowel signs, but they are inserted in quite a
different manner, the yod and waw much more frequently,
and the haleph, though not very often, yet oftener than in
the Hebrew; whence it is clearly evident, that they were
introduced into this text at a later period, and when the use
of such signs kad become better understood. It is further
to be observed, that the same vocalization also pervades all
the other kinds of Shemitic writing used in Asia, but is
fuller, and, consequently, of later insertion in each of them
than in the Hebrew. Andas it is inconceivable that so very
peculiar a system of vowel signs should have been adopted
by different people independently of each other, the proba-
bility is, that the Jews alone derived it immediately from
their acquaintance with Greek writing, and that the other
Asiatic tribes of the Shemitic class took it from them.

On the other hand, the vocalization of the Abyssinian
syllabary is wholly different from that which is common to
every other species of Shemitic writing, and must have been
derived from immediate observation of the Greek Scriptures ;
as the Ethiopic translation of the Bible affords very decisive
evidence that it was made, not from the Hebrew original,
but from the Septuagint version. Two of the letters, with
their powers, are here subjoined as a specimen :

Pow. to bo bor, oT

ta tine hae e ta en te untc to

PC) Pane eA Man A ane ee |

ki ku ki: ka ke ké ko
The period when the first column of this syllabary was de-
rived from some Shemitic alphabet cannot now be ascer-
tained; but a limit to the age of the system, in its present
improved form, can be deduced from ecclesiastical history ;
for the Abyssinians first received the Scriptures when they
were converted to Christianity by Frumentius, who was
consecrated bishop of Axum in the year of our Lord 335;

100

and there is not the slightest probability of their having
studied the nature of Greek writing before it became to
them the medium of religious instruction.

In order to compare the Abyssinian and Sanscrit sylla-
baries, it is necessary to leave out of consideration the
vowel sounds, in the latter system, of 2 in wine, and of ow in
pound, which do not occur in the Abyssinian language ; as
also the powers 17, rz, li, lt, an, ah, which the Brahmans,
through gross ignorance of the subject, have included among
their vowels. After this reduction, the syllables denoted by
the first of the Sanscrit letters will stand as follows :

a a fa at aa a at

ka ka kz kz ki ku ke ko
Kach of the other letters undergoes similar modifications of
shape for similar alterations of its syllabic powers.

Dr. Wall then proceeded to point out the close corres-
pondence which subsists between the two systems. Of the
many indications of their connexion, only two can be here
noticed. 1. Whenever an Ethiopic letter has no mark added
to it, the syllable it then denotes regularly ends in a short a;
the same rule is also observed in the case of every Sanscrit
letter. 2. Every syllable of the Ethiopic alphabet, as well
as every simple syllable of the Ethiopic language, begins
with a consonantal, and ends with a vocal power: the same
remark applies to every syllable of the Sanscrit syllabary,
but not to every simple syllable of the Sanscrit language.

A connexion between the two alphabets having been
proved, the circumstance last noticed still farther serves to
show the order which holds in that connexion, even without
any reference to what has been already stated upon the
origin of the Ethiopic alphabet. Of the systems compared
together, the Sanscrit syllabary must have been that which
was derived from the other; for it agrees with that other in
a peculiarity suited to the Ethiopic, but not at all adapted

101

to the Sanscrit language, in which there are several syllables
beginning with vowel sounds. To express such syllables the
Brahmans were obliged to adopt the European method, as
soon as their intercourse with the Greeks made them ac-
quainted with it. Their persevering in the use of their syl-
labary after they had acquired vowel letters, shows that they
were incapable of arriving at this improvement by their own
efforts; and they could not have learned it from observation
of any Shemitic writing, as in no kind of that writing are
vowel letters found placed before consonants for the expres-
sion of simple syllables. Thus the writing in the Devanagari
character at present exhibits the very extraordinary phe-
nomenon of two different sorts of alphabets employed toge-
ther; and it could not have been advanced to this state
before the fifth, or perhaps before the sixth century; for
the Pundits must have been long habituated to their sylla-
bary alone, or they would have deserted it as soon as they
came to learn the use of a superior alphabet.

In support of this view of the subject, Dr. Wall adduced
several arguments from history, from astronomy, from the
serious difficulties with which the opinion at present re-
ceived is embarrassed, from the nature of the Sanscrit lan-
guage, and from its grammatic structure.

Dr, Orpen presented the accounts, and petition to Par-
liament.

OrpeRED,—“ That the seal of the Academy be annexed.”

ResoLtvep,—‘‘ That the Academy cannot receive the inti-
mation of the vacancy that has occurred in Council since
their last meeting, by the sudden and lamented death of
their valued friend and associate, Dr. William West, without
placing on record their sincere feelings ofregret, at an event
which has snatched from the successful pursuits of Science,
one whose exertions had been honorably devoted to its cul-
tivation, and had been endeared by his social and amiable

102

qualities to the affections of his personal friends, as much as
to the friends of literature by his labours for its advance-
ment.”

Resotvep,—* That the Council be directed to prepare
and forward through the proper channel, an address to her
Majesty, Queen Victoria, condoling with her on the death
of his late Majesty, King William, congratulating her on
her accessien to the throne, and requesting ber Majesty’s
patronage for the Academy.”

DONATIONS.

Transactions of the American Philosophical Society, held
at Philadelphia, for promoting Useful Knowledge. Vol. V.
New Series. Part 3. Presented by the Society.

Mémoires de la Société Géologique de France. Vols. I.
and II. Parts! and 2. Presented by the Society. |

Bulletin de la Société Géologique de Franee. Tome VIII.
Feuilles 1—20. 5 Numbers. Presented by the same.

General Charte der Geographischen Verbreitung und des
Ganges der Cholera, 1816—37. By Emil Isensee. Pre-
sented by the Author.

Neues System zur Ubersicht der inneren Krankheiten des
Menschen. By the same. Presented by the same.

Transactions of the Royal Society of Literature of the
United Kingdom. Vol. Ill. Part 1. Presented by the
Society. : :
Royal Society of Literature.—Annual Report.—Presi-
dent's Address.—List of Members, 1837. Presented by the
same.

Memorias da Academia R. das Sciencias de Lisboa.
Tomo XII. Parte 1. Presented by the Society.

Transactions of the Statistical Society of London. Vol. I.
Part 1. Presented by the Society.

County Book of Kildare, Lent Asssizes, 1835. Presented
by Jeffries Kingsley, Esq.

103

Astronomische Nachrichten. By H. H. C. Schumacher.
Also Nos. 312—326. Presented by the Author.

Account of some Experiments made in different Parts of
Europe on Terrestrial Magnetical Intensity, particularly with
Reference to the Effect of Height. By James D.Forbes, Esq.,
F.R.SS.L. and E., F.L.S. Presented by the Author.

On the Temperatures and Geological Relations of certain
Hot Springs, particularly those of the Pyrenees ; and on the
Verification of Thermometers. By the same. Presented
by the same.

Note relative to the supposed Origin of the deficient Rays
in the Solar Spectrum: being an Account of an Experiment
made at Edinburgh during the annular Eclipse of 15th May,
1836. By the same. Presented by the same.

Ancient and Modern Alphabets of the popular Hindoo
Languages of the Southern Peninsula of India. By Captain
Henry Harkness, M.R. A.S. Presented by the Author.

Proceedings of the Royal Asiatic Society of Great Bri-
tain and Treland.—Anniversary Meeting, and Fourteenth
Annual Report of the Council, §c. Presented by the So-
ciety.

Researches on Hydrodynamics. By John Scott Russell,
Esq. M.A., F.R.S.E. Presented by the Author,

Histoire des Maladies observées a la grande Armée Fran-
caise, pendant les Campanes de Russie en 1812, et @ Alle-
magne en 1813. Par le Chevalier de Kerckhove dit de
Kirckhoff. Presented by the Author.

Journal of the Franklin Institute of the State of Pensyl-
vania and Mechanics’ Register. Vol. XIX. New Series.
Edited by Thomas P. Jones, M.D. Presented by the
Franklin Institute. |

Report of the Commitiee of the Franklin Institute of the
State of Pennsylvania, for the Promotion of the Mechanic Arts
on the Explosion of Steam Boilers, of Experimenis made at

104

the request of the Treasury Department of the United States.
Part II. Presented by the same.

De l Affinité des Langues Celtiques avec le Sanscrit. Par
Adolphe Pictet. Presented by the Author.

Proceedings of the Geological Society of London, Nos. 47
—51; together with a List of the Society, April 1st, 1837.
Presented by the Society.

The History of the Presbyterian Church in Ireland. Vol.
II. By James Seaton Reid, D.D., M.R.I. A. Presented
by the Author.

Etudes Grammaticales sur la Langue Euskarienne. Par
A. Th. d’Abbadie, et J. Augustin Chaho, de Navarre. Pre-
sented by the former.

Natuur kundige Verhan delingen van de Hollandske
Maatschappij der Wetenschappen te Haarlem. From Vol.
XUI. to XXXII. Presented by the Dutch Society.

Reports of the British Association for the Advancement
of Science. 5 Vols. Presented by the Association.

November 30. (Stated Meeting.)

His Grace the ARCHBISHOP OF DUBLIN, V. P.,
in the Chair.

The Secretary of the Council having officially communi-
cated the decease of the President,

Ir wAs RESOLVED,—“ That no further business should be
proceeded in, until the next Meeting of the Academy, on
Monday, December 11th, when it was resolved, that the
President, in place of Dr. Lloyd, and the new Member of
Council, in place of Dr. West, should be elected.”

Adjourned to Monday, December 11th, 1837.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1837—1838. No. 8.

December 11, 1837.

Rev. F. SADLEIR, D. D., Provost, T. C. D., Vice-Presi-
dent, in the Chair.

Tue Academy having proceeded to ballot for a President,
Sir Wittiam Rowan Hamitton was duly elected.

The Academy having proceeded to ballot for a Member
of Council in the Committee of Polite Literature, the Rev.
Charles Wm. Wall, D. D. was elected.

The Very Rev. James Gregory, Dean of Kildare, John
Finlay, Esq. Barrister, Samson Carter, Esq., and George
Pim, Esq. were elected Members of the Academy.

Adjourned to Monday, January 8th, 1838.

DONATIONS.

fiicerche sulla Struttura del caule nelle Piante Monoco-
tiledont di Guiseppe Meneghini. Presented by Samuel
Litton, M. D., Vice-President.

Astronomische Nachrichten, herausgegeben von H. C.
Schumacher. Vierzehnter Band. From No. 327 to 336,
inclusive. Presented by Professor Schumacher.

On the Elements of the Orbit of Halley's Comet, at its
Appearance in the Years 1835 and 1836. By Lieutenant
W. S. Stratford, R. N. (From the Nautical Almanac for
1839.) Presented by the Author.

L

106

The American Almanac and Repository of Useful Know-
ledge, for the Year 1838. Presented by the American
Philosophical Society.

January 8, 1838.
SIR Wm. R. HAMILTON, A.M., President, in the Chair.

The President, on taking the Chair, delivered an Address
to the Academy.

The Secretary of the Academy read a Memoir of the late
President.

Resotvep,—* That the President and Dr. Singer be
requested to furnish the Academy with copies of their
respective addresses.”

The Academy then proceeded to ballot for a Member of
Council in the Committee of Science, when Dr. Wm. Stokes
was elected.

DONATIONS,

A Treatise on the Diagnosis and Treatment of Diseuses
of the Chest. By Wm. Stokes, M. D., M.R.I. A. Pre-
sented by the Author.

Essays, Anatomical, Zoological, and Miscellaneous. By
A. Jacob, M.D., M.R.I.A. Presented by the Author.

The Anatomy of the Eye, from the Cyclopedia of Ana-
tomy and Physiology. By Dr. Jacob. Presented by the same.

List of Members of the Royal Asiatie Society of Great
Britain and Ireland, 1837. Presented by the Society.

Medical Science and Ethics ; an Introductory Lecture,
delivered at the Bristol Medical School, on Monday, October
2nd, 1837, at the opening of the Winter Session. By W.
Ogilvie Porter, M. D. Presented by the Author.

The Question of Privilege, raised by the Decision in the
Case of Stockdale v. Hansard. By S. A. Ferrall, Esq.,
Barrister at Law. Presented by the Author.

A Complete Set of the Transactions of the Italian Society
of Sciences. 39 vols. 4to. Presented by the Society.

107

INAUGURAL ADDRESS
BY THE PRESIDENT.

My Lorps anp GENTLEMEN OF THE Royat IrIsH ACADEMY,

The position in which your kindness has placed
me, entitles me, perhaps, to address to you a few remarks. Called
by your choice to fill a chair, which Charlemont, and Kirwan, and
others, not less illustrious, have occupied, I cannot suffer this first
occasion of publicly accepting that high trust to pass in silence by,
as if it were to me a thing of course. Nor ought I to forego this
natural opportunity of submitting to you some views respecting the
objects and prospects of this Academy, which, if they shall be
held to have no other interest, may yet be properly put forward
now, as views, by the spirit at least of which I hope that my own
conduct will be regulated, solong as your continuing approbation
shall confirm your recent choice, and shall retain me in the office
of your President.

First, then, you will permit me to thank you for having con-
ferred on me an honour, to my feelings the most agreeable of any
that could have been conferred, by the unsolicited suffrages of any
body of men. Gladly indeed do I acknowledge a belief, which it
would pain me not to entertain, that friendship had, in influencing
your decision, a voice as potent as esteem. An Irishman, and
attached from boyhood to this Academy of Ireland, I see with plea-
sure in your choice a mark of affection returned. But knowing that
the elective act partakes of a judicial character, and that the exer-
cise of friendship has its limits, I must suppose that the same long
attachment to your body, which had won for me your personal
regard, appeared also to you a pledge, more strong than promises
could be, that if any exertions of mine could prevent the interests
of the Academy from suffering through your generous confidence,
those exertions should not be withheld; and that you thought they
might not be entirely unavailing. After every deduction for kind-

ness, there remains a manifestation of esteem, than which I can
5,
wv

108

desire no higher honour, and for which I hope that my conduct
will thank you better than my words.

And yet, Gentlemen, it is to me a painful thought, that the
opportunity for your so soon bestowing this mark of confidence
and esteem has arisen out of the deaths, too rapidly succeeding
each other, of the two last Presidents of our body, who, while they
are on public grounds deplored, and for their private worth weré
honoured and beloved by all of us, must ever be remembered by
me with peculiar loveand honour :—Brinkley, who introduced me to
your notice, by laying on your table long ago my first mathematical
paper; and Lloyd, whoseworks, addressed to the University of Dub-
lin, first opened to me that new world of mind, the application of
algebra to geometry. But of these personal feelings, the occasion
has betrayed me into speaking perhaps too much already. Into
that fault, I trust, I shall not often fall again. I pass to the expo-
sition of views respecting the objects and prospects of our Society.

The Royal Irish Academy was incorporated (as you know) in
1786, having been founded a short time before, for the promotion
generally, but particularly in Ireland, of Science, Polite Literature,
and Antiquities. Its objects were to be the True, the Beautiful,
and.the Old: with which ideas, of the True and Beautiful, is inti-
mately connected the coordinate (and perhaps diviner) idea of the
Good. So comprehensive, therefore, was the original plan of this
Academy, that it was designed to include nearly every object of
human contemplation, and might almost be said to adapt itself to
all conceivable varieties of study; insomuch that scarce any me-
ditation or inquiry is directly and necessarily excluded from a place
among our pleasant labours: and precedents may accordingly
be found, among our records, for almost every kind of contribu-
tion. If only a diligence and patient zeal be shown, such as befit
the high aims of our body ; and if due care be taken, that the spirit
of love be not violated, nor brother offend brother in anything;
no strict nor narrow rules prevent us from receiving whatever may
be offered to our notice, with an indulgent and joyful welcome.
And though we meet only as studious, meditative men, and abstain
from including among our objects any measures of immediate, out-
ward, practical utility, such as improvements in agriculture, or
other useful arts,—a field which had been occupied, in this metro-

109
polis, by another and elder society, before the institution of our
own ; yet no philosopher nor statesman, who has reflected suffi-
ciently on the well-known connexion between theory and practice,
or on the refining and softening tendencies of quiet study, will
think that therefore we must necessarily be useless or unimportant
as a body, to Ireland, or to the Empire.

The object of this Academy being thus seen tobe the encourage-
ment of stupy, we have next to consider the means by which we are
to accomplish, or to tend towards accomplishing that object. Those
means are of many kinds, but they may all be arranged under the two
great heads of inward and outward encouragement ; or, in other
words, stimuli and assistances ; inshort, spuRSand HELPS to study.
The encouragement that is given may act as supplying a motive,
or as removing a hindrance; it may be indirect, or it may be
direct ; invisible or visible; mental or material. Not that these
two great kinds of good and useful action are altogether separated
from each other. On the contrary, they are usually combined ;
and what gives a stimulus, gives commonly a facility too. In our
meetings, for example, the stimulating principle prevails ; yet in
them we are not only caused to feel an increased zxterest in study
generally, through the operation of that social spirit, or spirit of
sympathy, of which I spoke so largely, in the presence of most of
you, at the meeting of the British Association* in this city ; but
also are directly assisted in pursuing our own particular studies, by
having the results of other studious persons early laid before us,
and commented upon, by themselves and by others,’ in a fresh
familiar way. We are not only spurred but helped to study, by
mixing freely with other students.—A library, again, is designed
rather to assts¢ than to stimulate; and yet it is impossible for a
person of ardent mind to contemplate a well selected assemblage of
books, containing what Milton has described as “the precious life-
blood of a master-spirit, embalmed and treasured up on purpose to a
life beyond life,” without feeling a deep desire to add, to the store
already accumulated, some newer treasure of his own. Our

* See the Address printed in the Fifth Report of the British Association for the
Advancement of Science,x—Note by PRESIDENT.

110

library, then, spurs as well as helps.—The prizes which from
time to time we award for successful exertion in the various de-
partments of study, might seem to be stimulants only ; yet if we
were to act sufficiently upon the spirit of precedents, of which we
have several among our past proceedings, and which allow us to
make our awards in part pecuniary, as well as honorary, they might
become important assistances, and not merely excitements to
study; they might serve, for instance, to enrich the private libraries
of the authors on whom they were conferred. Why might we not,
for example, instead of giving one gold medal, which can (accord-
ing to the custom of this country) only be gazed at for a while and
then shut up, allow the author who has been thought worthy of a
prize to select any books for himself, which he might think most
useful for his future researches, within a certain specified limit of
expense ; and then not only purchase those books for him out of
our own prize funds, but also stamp them with the arms of the
Academy, or otherwise testify that they were given to him by us as
areward? Or might not some such presentation of books be at
least combined with the presentation of medals? But the whole
system of prizes will deserve an attentive reconsideration, for which
this is not the proper time nor place; and anything that I may now
have said, or may yet say on that subject, in this address, is to be
looked upon as merely intended to illustrate a few general views
and principles, and not as any proposal of measures for your
adoption; since, upon measures of detail, I have not as yet even
made my own mind up; and am aware that, by the constitution of
our Society, all measures of that kind must first be matured in the
Council, before they are submitted to the Academy at large for
final sanction or rejection.

The publication of our Transactions is another field of action
for our body, and perhaps the most important of all; in which it is
not easy to determine whether the stimulating or the assisting prin-
ciple prevails ; so much both of inducement and of facility do they
give to study and to its communication. It is indeed a high reward
for past, and inducement to future labours, to know that whatever
of value may be elicited by the studies of any members of this
body, (nor are we to be thought to wish to confine the advantage
to them,) is likely or rather is sure to be adopted by the Society at

111

large, and published to the world, at least to the learned world, in
the name and by the order of the whole:—the responsibility for any
errors of detail, and the credit for any merit of originality, remain-
ing still in each case with the author, while the Academy exercises
only a right of preliminary or primd facie examination, and a su-
perintendence of a general kind. Nay, the more rigorous this pre-
liminary examination is, and the more strict this general superin-
tendence, the greater is the compliment paid to the writer whose
productions stand the test; and the more honourable does it become
to any particular essay, to be admitted among the memoirs of a
Society, in proportion as those memoirs are made more select, and
expected and required to be more high. But besides this honorary
stimulus, which we should all in our several spheres exert ourselves
to make more effective, by each endeavouring, according to his
powers, to contribute, or to judge, or to diffuse, there is also a
powerful and direct assistance given to study, by the publishing of
profound intellectual works at the expense of a corporate body,
rather than at the expense of individuals; a course which spares
the private funds of authors and of readers ; and thus procures, for
the collections of learned and studious men, many works of value,
which otherwise might never have appeared. Indeed, the publica-
tion of Transactions has long been regarded by me as the most di-
rect and palpable advantage resulting from the institution of scien-
tific and literary societies like our own ; and, I believe, that I ex-
preessed myself accordingly, on the occasion* to which T lately
alluded. But having then to deal with science only, I felt that it
was unnecessary, and would have been improper for me to have
introduced any view of the connexion and contrast between science
and other studies, which are, not less than science, included among
the objects of this Academy, and may therefore be fitly, if briefly,
brought now before your notice, The union of all studies is in-
deed that at which we aim; but the three great departments, which
our founders distinguished without dividing, may now also with
advantage be distinctly considered, and separated, that they may
may be re-combined ; a clearness of conception being likely to be
thus attained, without any sacrifice of unity.

* See Address, already cited, p. xlvii—Note by PRESIDENT,

112

Directing our attention, therefore, first to science, or the study
of the True,— ;

Inter sylvas Academi querere verum,—

we find that, even when thus narrowed, the field to be examined is
still so wide as to make necessary a minuter distinction ; whether
we would inquire, however briefly, what has been already done by
this Academy, or what may fitly be desired and hopefully proposed
to be done. Were we to rush into this inquiry without any pre-
vious survey of its limits, and, as were natural, allowed ourselves
to begin by considering the actual and possible relation of our
studies to the primal science, or First Philosophy, the Science of
the Mind itself; we might easily be drawn, by the consideration of
this one topic, into a discussion, interesting indeed, and (it might
be) not uninstructive, but of such vast extent as to leave no room
for other topics, which ought even less to be omitted, because they
have hitherto come, and are likely to come hereafter, more often than
it before our notice, in actual contributions to our Transactions.
Indeed I think it prudent at this moment to resist altogether the
temptation of expatiating on this attractive theme, of Philosophy,
eminently so called; and to content myself with remarking, that
as metaphysical investigation has more than once already found
place among the scientific labours of this Academy, so ought it to
take rank among them still, and to reappear in that character, from
time to time, in our pages.

Confining ourselves, therefore, at present ‘to Science, in the
usual acceptation of the term, and inquiring what are its chief di-
visions, in relation mainly to the connected distribution or classifi-
cation of scientific essays in our Transactions, we soon perceive that
three such parts of science may conveniently be distinguished from
each other, and marked out for separate consideration ; namely those
three, which, with some latitude of language, are not uncommonly
spoken of as Mathematics, Physics, and Physiology. The first, or
mathematical part, being understood to include not only the pure
but the mixed mathematics; not only the results of our original
intuitions of time and space, but also the results of the combination
of those intuitions with the not less original notion of cause, and
with the observed laws of nature, so far and no farther than that

113

ever-widening sphere extends, within which observation is subor-
dinate to reasoning ; in short, all those deductive studies, in which
Algebra and Geometry are dominant, though the dynamical and
the physical may enter as elements also. The second, or physical
part of science, embracing all those inductive studies respecting un-
living or unorganized bodies, which proceed mainly through out-
ward observation or experiment, and can as yet make little progress
in “ the high priori road.” And finally, the third, or physiological
part, including all studies of an equally inductive kind, respecting
living or organized bodies. (I do not pretend that this arrange-
ment is the most philosophical that can be imagined, but it may
suffice for our present purpose.)

Tn all these divisions of science, and in several subdivisions of
each, our published Transactions contain many valuable essays ;
and there seems to be no cause for apprehension that in this res-
pect, at least, (if indeed in any other,) the Academy is likely to lose
character. Death has, it is true, removed some mighty names from
among us—elders and chiefs of our society: but the stimulus and
instruction of their example have not been thrown away: an ardent
band of followers has been raised up by themselves to succeed them.
'To keep the trust thus handed down, is an arduous, but noble
charge, from which it is not to be thought that any here will shrink,
whatever his share of that charge may be.

And yet, while Mathematics and Physics seem likely not to be
neglected here, or rather certain to be ardently pursued, it may be
pardoned me if I express a fear and a regret, that Physiology, or
more precisely, the study of the phenomena and laws of life, and
living bodies, has not been represented lately’ in the published
Transactions of our Academy, to a degree correspondent with the
eminence of the existing School of physiological study in Dub-
lin. Our medical men and anatomists, our zoologists and bota~
nists also, will take, I hope, this little hint in good part. They
know how far I am from pretending to criticize their productions,
and that I only wish to have more of their results brought for-
ward here, for the instruction of myself and of others. That is
not, I think, too much to ask from gentlemen who have sub-
scribed the obligation which is signed by every member of this

114

body, and who are qualified, by intellect and education, to take an
enlarged yet not exaggerated view-of the importance of a central
society. I know that many other, and indeed more appropriate
outlets exist, for the publication of curious, isolated, or semi-iso-
lated facts: but it is not so much remarkable facts, as remarkable
views, that I wish to see communicated to us, and through us to
the world; although such views ought, of course, to be illustrated
and confirmed by facts.

It seems possible, that in each of the three great divisions of
science already enumerated, our Transactions may be enriched in
future, through a judicious system of rewards, (of the kinds to
which I lately alluded,) intended to encourage contributions of a
more elaborate kind than usual, from strangers as well as from
members of our body. It has appeared, for example, to some
members of your Council, and to me, that for each of those three
divisions of science a triennial prize might be given; these three
triennial prizes succeeding each other in such rotation, for mathe-
matics, physics, and physiology, that a prize should be awarded
every year, on some one principal class of scientific subjects, for
the best essay which had been communicated for publication, on
any subject of that class, whether by a member or by a stranger,
curing the three preceding years. A plan of this sort has been
lately tried, and (it would seem) with advantage, in the distri-
bution of the Royal Medals entrusted by the late King* to the Royal
Society of London ; and the principle is not unsanctioned by you,
that a greater range of investigation may sometimes be allowed to
the authors of prize-essays, than the terms of an ordinary prize-
question would allow. So that it only remains for your Council to
consider and report to you, as they are likely soon to do, to what
extent this principle may advantageously be pushed, and by what
regulations it may conveniently be carried into effect. In saying
this, I do not presume to pronounce that it is expedient to give up
entirely the system of proposing occasionally prize-questions, of a
much more definite kind than those to which I have been referring

* And continued by her present Majesty : whose gracious intention of becoming
Patroness of the Royal Irish Academy has been made known since the delivery of
this Address.—Note by PRESIDENT.

115

as desirable; but thus much I may venture to lay down, that
original genius in inquirers ought to be as far indulged as it is pos-
sible to indulge it, both in respect of subject and of time; and that
due time ought also to be allowed to those members of a Scientific
Society, on whom is put the important and delicate office of pro-
nouncing an award in its name.

The length at which I have spoken of our relations to Science,
as a Society publishing Transactions, though far from exhausting
that subject, leaves me but little room, in this address, to speak of
our relations to Literature and Antiquities ; subjects to which, in-
deed, I am still less able to do justice, than to that former theme.
But the spirit of many of my recent remarks applies to these other
subjects also; and you will easily make the application, without
any formal commentary from me. A word or two, however, must
be said on some points of distinction and connexion between the
one set of subjects and the other.

As, in Science, or the study of the Zrwe, the highest rank must
be assigned to the science of the investigating Mind itself, and to the
study of those Faculties by which we become cognizant of truth ;
so, in Literature, or the study of the Beautiful, the highest place
belongs to the relation of Beauty to the mind, and the study of
those essential Forms, or innate laws of taste, in and by which,
alone, man is capable of beholding the beautiful. Above all par-
ticular fair things is the Idea of Beauty general : which in proportion
as a man has suffered to possess his spirit, and has, as it were,
won down from heaven to earth, to irradiate him with inward
glory, in the same proportion does he become fitted to be a minister
of the spirit of beauty, in the poetry of life, or of language, or of
the sculptor’s, or the painter’s art. The mathematician himself may
be inspired by this in-dwelling beauty, while he seeks to behold
not only truth but harmony; and thus the profoundest work of a
Lagrange may become a scientific poem. And though I am aware
that little can be communicated by expressions so general (and
some will say so vague) as these, and check myself accordingly,
to introduce some remarks more specific and definite; yet I will
not regret that I have thus for a moment attempted to give words
to that form of emotion, which many here will join with me in
acknowledging to be the ultimate spring of all genuine and genial

116

criticism, in literature and in all the fine arts. For we, in so far
as we are an Academy of Literature, are alsoa Court of Criticism ;—
Criticism which is to Beauty, what Science is to Nature. Between
the divine of genius and the human of enjoyment, we hold a kind
of middle place; creating not, nor merely feeling, but aspiring to
understand: and yet incapable of rightly understanding, unless we
at the same time sympathize.

To express myself then in colder and more technical terms, I
should wish that metaphysico-ethical and metaphysico-zesthetical
éssays,—those which treat generally of the beautiful in action and in
art, and are connected rather with the study of the beauty-loving
mind itself, than of the particular products or objects which that mind
may generate or contemplate,—should be considered as entitled to the
foremost place among our literary memoirs. After these a priort
inquiries into the principLes of beauty, which are rather prepa-
ratory to criticism than criticism itself, or which, at least, deserve
to be called criticism universal, should be ranked, I think, that
important but @ posteriori and inductive species of criticism,
which, from the study of some actual master-pieces, collects certain
great RULES as valid, without deducing them as necessary from
any higher principles. And last, yet still deserving of high honour,
I would rank those researches of peTaiL, those particulars, and
helps, and applications of criticism, which, if they be, in a large
philosophical view, subordinate and subsidiary to principles, and
to rules of universal validity, yet form perhaps the larger part of the
habitual and ordinary studies of men of erudition; such as the
differences and affinities of languages, and the explication of ob-
scure passages in ancient authors. Whatever metaphysical pre-
ference I may feel for inquiries of the two former kinds, no one, I
hope, will misconceive me as speaking of this last class of
researches with any other feelings than those of profound respect,
and of desire and hope to see them cultivated here; nor as present-
ing other than hearty congratulations to the Academy on the fact,
that whereas no single paper on Literature appeared in our last
volume, two memoirs, interesting and erudite, have been presented
to us, and probably are by this time printed, to be in readiness for
our next publication ;—one, on the Punic Passage in Plautus, by a
near-and dear relative of my own; and the other, on the Sanscrit

i17

Language, by a gentleman of great attainments and of high station
in our national University: from which seat of learning, it seems
not too much to hope, that we shall soon receive many other con-
tributions in the department of Polite Literature, as well as in
other departments. It is, of course, understood that the awarding
of prizes is not to be confined to scientific papers, but is to be ex-
tended, as indeed it has always been, under some convenient regu-
lations, to literary and antiquarian papers also.

I was to say a few words respecting that other department of
our Transactions, namely, Antiquities, or the study of the Old;
and if, at this stage of my address, those words must be very few, I
regret this circumstance the less, because I know that the study is
deservedly a favourite here, and that I am surrounded by persons
who are, beyond all comparison, more familiar with the subject
than myself.

In general, I may say, that whether the study of Antiquities be
regarded in its highest aspect, as the guardian of the purity of his-
tory,—the history of nations and of mankind; or as ministering to
literature, by recovering from the wreck of time the fragments of
ancient compositions ; or as indulging a natural and almost filial
curiosity to know the details of the private life of eminent men of
old, and to gaze upon those relics which invest the past with
reality, as the paleontologist from his fossils reconstructs lost
forms of life: in all these various aspects, the study is worthy to
interest any body of learned men, and to occupy a considerable part
of the Transactions of any society so comprehensive as our own.
The historian of the Peloponnesian war was also himself an anti-
quarian ; and prefaced that work which was to be “‘a possession for
ever,’ by an inquiry into the antiquities of Greece. And while he
complained of the curws araratorwpos trois mWorArois in Catnots Ths aAn-
Qetas, that easy search after truth which cost the multitude nothing;
he also claimed to have arrived at an és rexynpiov, a linked chain of
antiquarian proof, by which he could establish his correction of their
errors. Indeed, the uninitiated are apt to doubt,—perhaps too they
may sometimes smile,—when they observe the earnest confidence
which the zealous Antiquary reposes in results deduced from argu-
ments which seem to them to be but slight; nor dare I say that I

118

have never yielded to that sort of sceptical temptation. But
I remember a fact which ought to have given me a lesson, on
the danger of hastily rejecting conclusions which have been ma-
turely considered by others. A learned Chancellor of Ireland,
now no more, assured me often and earnestly, that he gave
no faith to the inductions of astronomers respecting the dis-
tances and sizes of the sun and moon; and hinted that he
disliked our year, for containing the odd fraction ofa day. Yet
this was a man, not only of great private worth, but of great
intellectual power, and eminent in his profession as in the state.
Astronomers and mathematicians, it may be, look sometimes on
other inductions with a not less unfounded incredulity. It is one
of the advantages of an Academy, so constituted as ours is, that it
brings together persons of the most different tastes and the most
varied mental habits, and teaches them an intellectual toleration,
which may ripen into intellectual comprehension. Thus, while
the antiquary catches from the scientific man his ardent desire for
progression, and for that clearer light which is future, the man of
science imbibes something in return, of the antiquarian reverence
for that which remains from the past. The literary man and the
antiquary, again, re-act upon each other, through the connexion of
the Beautiful and the Old, which in conception are distinct, but in
existence are often united. And finally, the scientific man learns
elegance of method from the man of literature, and teaches him pre-
cision in return.

Before I leave the subject of Transactions, I may remark that
their value, both as stimulants and as assistants to study, must
much depend on the rapidity and extent of their circulation, and on
the care that is taken to put them as soonas possible into the hands
or within the reach of studious men abroad. Reciprocally it is of
importance that measures should be taken for obtaining speedy in-
formation here of what is doing by such men in other countries.
On both these points, some reforms have lately been made, but
others still are needed, and will soon be submitted to your Council.
On these and all questions of improvement, I rely upon receiving the
assistance of all those gentlemen who are in authority among us;
but especially am encouraged by the hope of the cordial co-opera-

119

tion of your excellent Vice-President, Professor Lloyd, who has
done so much already for this Academy, in these and in other
respects.

It may deserve consideration, as connected with the last-men-
tioned point, whether Reports upon some foreign memoirs of emi-
nent merit, accompanied by extracts, and, perhaps, translations,
might not sometimes be advantageously called for. There is, I
think, among our early records, some hint that the Academy had
oncea paid Translator. It may or it may not be expedient to revive
the institution of such an office ; or to give direct encouragement to
the exertions of those,* who, without any express reference to our
own body, work in this way for us, while working for the public;
but no one can doubt that it is desirable to diminish the too great
isolatedness which at present exists among the various learned bo-
dies of the world. The Reports of the British Association on the
actual state of science in each of its leading subdivisions, do not
exactly meet the want to which I have alluded; because, upon the
whole, they aim rather at condensing into one view the ultimate
conclusions of scientific men in general, than at diffusing the fame
and light of individual scientific genius, by selecting some few
great foreign works, and making known at home their method
as well as well as their results. Besides we must remember that
far as that colossal Association exceeds the body to which we be-
long, in numbers, wealth, and influence, yet in plan it is less com-
prehensive ; since it restricts itself to science exclusively, while
we aspire, as I have said, to comprehend nearly the whole sphere
of thought,—at least of thought as applied to merely human things:
in making which last reservation, I shall not, I hope, be supposed
wanting in reverence for things more sacred and divine.

With that powerful and good Association, however, we should en-
deavour to continue always on our present, or if possible, on closer
terms of amicable relation. I need not say that we should also
aim to preserve and improve our friendly relations with all the

* For instance, Mr. Richard Taylor, of London, F.S. A., &c., who lately began
to publish Scientific Memoirs, selected and translated from the Transactions of Fo-
reign Academies of Science, and other foreign sources; which valuable publication
is now suspended for want of sufficient support from the public.— Note by PRESIDENT.

120

other Scientific, Literary, and Antiquarian Societies, of these and
of foreign countries. Especially we ought to regard, with a kind
of filial feeling of respect and love, the Royal Society of London—
that central and parent institution, from which so many others
have sprung ; over which Newton once presided ; and in which our
own Brinkley wrote. While feelings of this sort are vigilantly
guarded, and public and private jealousies excluded vigilantly, a
vast and almost irresistible moral weight belongs to companies
like these, of studious men ; and, amid the waves of civil affairs,
the gentle voice of mind makes itself heard at last. Societies such as
ours, if they do their duty well, and fulfil, so far as in them lies,
their own high purpose, become entitled to be regarded as being,
on all purely intellectual and unpolitical questions, hereditary
counsellors of crown and nation. The British Association has al-
ready made applications to government with success, for the ac-
complishment of scientific objects; and I am not without hopes
that our own recent memorial, for the printing, at the public ex- _
pense, of some valuable manuscripts in our possession, adapted to
throw light on history, and interesting in an especial degree to us
as Irishmen, will receive a favourable consideration.

On the present occasion, which to me is solemn, and to you not —
unimportant, I may be pardoned for expressing, in conclusion, the
pleasure which it gives me to believe, that while we cautiously ab-
stain from introducing polemics or politics, or whatever else might
cause an angry feeling in this peaceful and happy society, some great
and fundamental principles, of duty to heaven and to the state, are
universally recognized amongstus. Admitted at an early age to join
your body, I now have known you long, and hope to know you
longer ; but have never seen the day, and trust that I shall never
see it, when piety to God, or loyalty to the Sovereign, shall be out
of fashion here,

MEMOIR OF THE LATE PRESIDENT,

BY THE REV. J. H. SINGER, .D.D.,

SECRETARY OF THE ACADEMY,

Tue lives of men of science are proverbially devoid of incident ;
abstracted from the bustle and business of the great world with-
out, and deriving their happiness as well as their occupation from
the little world within, we but seldom find them influenced by the
vicissitudes that shed the interest of adventure over the course of
the legislator, the diplomatist, or the warrior. Even the steps
that have led the scholar to eminence, the light that first dawned
upon the path of invention, and the process by which conjecture
has been gradually matured to certainty,—even these are too fre-
quently unknown; and though they present the most interesting
problems in intellectual science, are sometimes concealed by the
modesty of him who is their subject, and sometimes forgotten
or dimmed to recollection by the splendour of advancing disco-
very. The life of our late President, though so important in its
relation to the progress of education and science in this country,
furnishes no exception to the general statement we have made ; and
although his mind must have nurtured for years the germs of im-
provement by which his memory has been made illustrious, it was
in the silence and secrecy of his own solitary reflections.
BartHoLomew Luoyp was born in the year 1772, and having
been at an early period of life deprived both of his father and of his
uncle, to whose care he had been committed after his father’s death,
he entered soon upon those struggles with the world in which, by
energy and perseverance, he was to obtain so signal a victory. At
the age of fifteen heentered the University, and by his talents and as-
siduity soon made himself conspicuous, obtaining successively aScho-
larship and Fellowship in 1790, and 1796, on high and distinguished
answering. On the numerous but important duties that devolved
on him as tutor, or on the manner in which he fulfilled them, it is
unnecessary to dilate. The affectionate recollections of his nume-
M

122

rous pupils, many of whom have attained to rank and respectability,
and many of whom surround me, prove equally the interest he took
in their welfare, and his exertions to secure it; while the knowledge he
acquired in Mathematics and Natural Science, evince that his hore
subsecive, were not devoted to personal ease or relaxation. His
character for labour and research was sufficiently developed to
justify his appointment, while a Junior Fellow, to the Professor-
ship of Mathematics, on Dr. Magee, the late Archbishop of Dublin,
retiring from that situation: and some years afterwards, to that of
Natural Philosophy. To the manner in which he filled those im-
portant stations, academic and public opinion has long since given
its approbation ; and it was in full accordance with that opinion,
loudly and unanimously expressed, that when the present Bishop of
Cork was raised to that see, Dr. Lloyd was elevated from among
the Fellows of the University, to preside as Provost over its in-
terests.

This event, hailed by every friend of science and education,
took place in 1831, and perhaps no six years in the history of
any institution can be compared to those which passed under his
brief administration, with regard to substantial improvement,
changes rapid, though well weighed, and reform mild and prudent,
yet searching and effective. Scarcely a portion of the system of
education but was subjected to consideration, and in many in-
stances to changes fully justified by experience ; and while we now
look back with astonishment upon all that the energy and discrimi-
nation of one man could effect, we must not withhold our high
approbation from those, who, unimpeded by any love of system, or
habit, or prejudice, seconded so nobly his exertions: and we may
rejoice that he was enabled to compass such a mass of reform, with-
out experiencing a failure, and without endangering a friendship. On
the regretted death of our President, the justly esteemed Bishop of
Cloyne, the choice of the Academy almost unanimously devolved
on Dr. Lloyd; and he who had shewn himself the active, intelli-
gent, and instructed patron and promoter of every useful science,
himself no mean proficient in all,—he who mainly by his influence
and character had collected -here the representatives of science
from every quarter of the globe, and made the metropolis of Ire-
land, for the season, that of natural knowledge,—he was elected
almost by acclamation to preside over the meetings of the Royal

123

Irish Academy, many of whose members had felt the fostering of
his kindness, and his friendship, and his direction in earlier life.
But for two short years has he presided over this institution, years
marked by unremitting attention upon his part to its interests; and
although its present maturity of usefulness and exertion can scarcely
be traced to his personal influence, over that exertion he carefully
watched, with its progress he sincerely sympathized, and by every
means in his power stimulated and applauded. A large portion of
the morning of his lamented removal was occupied in tracing and
rejoicing over the successive improvements of this Academy ; and
anticipating with melancholy pleasure its still further advancement.
I say melancholy, for with that species of darkened feeling, which
“the shadow of coming events” frequently produces, the Provost
did not expect to witness its growth in prosperity, and he spoke of
it as of a dear friend from whom he must expect to be parted, but
who should have his best and sincerest wishes; as of a child to
whom he would bequeath a legacy of anxious, affectionate, and
longing remembrances. Such we may-feel convinced was the emo-
tion with which our late President regarded this institution, and it
is a claim upon our grateful recollection of departed worth, that so
long as any thing merely earthly occupied his attention, our in-
terests and our welfare were entwined with his latest aspirations.

A few observations upon the claims which our late President, as
a man of letters and science, has upon the gratitude of the lite-
rary and scientific public, will fitly close this brief memorial. When
Dr. Lloyd was called to the Mathematical chair of the University,
that science was at a low ebb in Ireland. The names and examples
of Brinkley and Davenport, and a few others, had failed to produce
any effect, and the misinterpreted and mistaken glory of Newton
had formed here as well as elsewhere a barrier to the progress of his
followers in the sciences he had made illustrious, and prevented
them using for their further development the very instruments he
had himself discovered and employed. This our President had seen,
and over it he had mourned; and the first object of his exertions when
enabled to speak with authority to the Academic youth, was to incite
them to new fields of labour, to point out new regions to investigate
and subdue; he exhibited himself as their fellow-student and
fellow-workman, sharing their difficulties and rejoicing in their

124

triumphs. Nor did he only urge them forward; he held upa torch to
direct their steps, and his elementary works upon Geometrical Ana-
lysis and Mechanics, adopted as the Text-books in the University,
prove how completely he identified himself with the progress of the
student, while at the same time they illustrate the power of that
mind which could grapple with and overcome the most difficult of
all intellectual labours, the rendering familiar and facile the elements
of science. And our President was successful. The mind of our
youth required but to be stimulated and directed. We are now as it
were centuries in advance of what we, a few years ago, viewed as the
limit of attainment, and many, whom to praise would be superfluous,
and whom I would name, but that they are present, form the best
comment on our President’s zeal and foresight.

As Provost, the same great objects were ever present to his mind.
Education, over which he presided, called for his undivided atten-
tion, and he bestowed it ; and by the changes which he effected in
its literary, scientific, and ethical departments, he has acquired for
himself among the friends of the mind of Ireland imperishable glory.
This is not the place to speak in detail of the many improvements he
suggested or adopted; of the different courses of study which he
supplied to the differing inclinations or tendencies of mind; of the
elevation of mental and moral science to the station, which, in such
a country as ours, it should maintain; of the separation of the im-
portant duties of the Professor from the laborious and important,
but subordinate, occupation of the Tutor ; still less of the zeal with
which he watched over the theological course of the University,
and laboured to raise it to meet the exigencies of the times, and
the wants of the people. If the prosperity of a country be in-
separably connected with the education of the higher and middle
classes of the population, and if the progress of science and litera-
ture be the never-failing index of a civilized and moralized popu-
lation, then must the individual who extends or improves education
be ranked among the truest lovers of their country, and the name
of Lloyd will be handed down among the benefactors of Ireland,

Nor was our late President exclusive in his attachment to Science
or to Instruction; while the medical school connected with the Uni-
versity received his fullest consideration, and enjoyed the advantages
of his reforms,—on natural science, in all its branches, he bestowed

125

his attention and his patronage. Of one Society (the Geological)
he was, I believe, one of the original founders, as well as one of its
first Presidents, and always an anxious and zealous member ; under
his auspices was the Magnetic Observatory commenced in the
University, which promises to supply so perfectly a desideratum
in British Science, and which must so powerfully tend not only
to the elucidating of the most recondite and interesting problems
in natural knowledge, but to the practical improvement of many of
the most important instruments of general utility; and the very
latest plan proposed by him to the Board of the University, was
one for extending instruction in natural history, and rendering the
acquisition of information in its varied departments more acces-
sible. To mental science he had paid in early life considerable
attention, and the respect he felt for it is manifest in the creation
of the professorship of Moral Philosophy. All who have heard
him as a preacher in the University must remember the clear and
lucid style, the mild and earnest, and persuasive manner which, in
spite of physical defects, rendered him most attractive in the pul-
pit; and they cannot forget the accuracy of conception, and keen
and discriminating judgment which could penetrate into the depths
of the metaphysics of theology without obscuring the subject, or
dimming its sanctity. Some idea of what he was as a preacher
may be had from the volume of sermons he published on some of
the most abstruse topics in Divinity ; and a specimen of his taste and
judgment in the metaphysics of literature is exhibited in some beau-
tiful but fragmentary dissertations published several years since in
the Dublin Journal of Science. As a writer our President has not
left much; the elementary but admirable works alluded to, the
essays and sermons, I believe, comprise the whole; his business
was not so much to advance science himself as to stimulate and
direct others ; not to press forward in his own person, leaving the
path in darkness, but to hold high the torch for the young aspirant, —
to mark the road. It is, however, an interesting fact, that he has
left a large collection of manuscripts behind, the natural result
of a well-stored, active, and inventive mind, and it is not to be
doubted but that our fellow academic and Vice-President, the heir
of his name and of his talents, will not suffer a grain of his father’s
gold to be lost.

126

In one other point of view might our President be contem-
plated, but it is unnecessary. He could be spoken of as the gen-
tleman and the Christian, as one whose character impressed the
respect, which his manners associated with affection ; as one whose
gentleness, urbanity, and good feeling converted every one that
approached him into a friend, and rendered the intercouse of official
duty a privilegeand a pleasure. Our President’s manners were bene-
volent, because his mind was essentially so; because he anticipated
and provided for the feelings of every one with whom he had inter-
course both on great and small subjects; because, incapable of feel- —
ing jealousy or envy, he was always desirous of bringing every indi-
vidual fully and entirely forward, and as there never was one who
lived more for others and less for himself, so there never has been one
who manifested such a characteristic more decidedly in his manner
and deportment. But it is unnecessary to proceed—more would on
this topic be unnecessary to those who in public and in private have
witnessed or have experienced the influence I have mentioned; and
enough has been said, however feebly, to meet in some degree the
wishes of the Academy, its sense of justice, of gratitude, and of
affection ; that one who shared so materially in the first triumphs of
abstract science in this country should not pass off the stage unno-
ticed and unlamented in this room, dedicated to the pursuit of that
science and that literature which he loved,—that one with whom
every advance of science in Ireland will by impartial posterity be
associated, should from us, his contemporaries, receive some meed
of his renown, and that while our kindred institution, the Univer-
sity, is endeavouring to connect his name imperishably with the
exertions and the rewards of the aspirants after scientific fame, we
who enjoyed his intercourse and can claim his latest recollections,
should add too our mourning tribute of applause to hang upon his
bier.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1838. No. 9.

January 22.

SIR Wm. R. HAMILTON, A.M., President, in the Chair.

A Letrer from Colonel Yorke was read, enclosing a copy
of Lord John Russell’s letter to the Lord Lieutenant, in-
forming his Excellency that the Academy’s address to the
Queen was very graciously received, and that her Majesty
has been pleased to consent to become the Patroness of the
Academy.

Sir William Betham read a paper on the “ Eugubian
Inscriptions” preserved at Gubbio, an Episcopal city in the
Papal states, on seven plates of bronze, which were disco-
vered on excavating the crypt of an ancient temple there in
the year 1444. Five of the inscriptions are in the old Etruscan
character, written from right to left, like the Hebrew and
other Shemitic languages; two, the sixth and seventh, are
in what is now called the Roman character, written from left
to right. Two other plates were found at the same time,
and were sent to Venice in the year 1505, but never re-
turned.

The object of Sir William Betham’s paper was to show
that the ancient Etruscan language was identical with the
Iberno-Celtic, and, that the Irish language, as it is still
spoken in this country, affords the true clue to the interpre-

N

128

tation of these inscriptions, which have baffled the efforts of
so mary learned men.

The author read to the Academy ii translation of the
sixth and seventh tables, (those written in the Roman cha-
racter), which he selected as containing matter of great inte-
rest to the inhabitants of these countries, being a record of
the discovery of the use of the magnetic needle in naviga-
tion, and of the British Islands, by the ancient Etruscans.

The following is an abstract of the facts recorded in these
very ancient documents, according to Sir William Betham’s.
translation of them:

The sixth table commences with an invitation to the
people, to go “to divide and farm the western lands,” and to
proceed to the west, “where are three islands” of rich and
productive soil, with cattle and sheep in abundance, and
large black deer, productive of mines, with fine streams and
every advantage for residence. It then proceeds to state,
that the ships which were fitted out to convey settlers had
been provided with stored food and abundant provisions for
the voyage, with good water zn skins to be served out daily ;
that the skill and seamanship of the commanders and the
men guaranteed their safety ; and that the people might ven-
ture to go, with the most perfect confidence, over the ‘for
ages untracked wilderness of the sea.’ 'Then is depicted the
wretched system of coasting navigation, which confined the
trader to the shores, amidst shoals, rocks, surfs, and other
imminent dangers, all which had been overcome and avoided
by the discovery of the little pointer, (the PIAC LU), by
which they were enabled to cross from coast to coast in ‘ the
same certain and established track ; and the high seas, which
the mariner formerly contemplated with the greatest appre-
hension when out of sight of land, might be crossed with
certainty, avoiding all dangers in deep water. ‘‘ It was be-
come trade's plain, a noble space, an easy space, a shortened
space, tracked space, man’s own space, the means of trade’s

129

"progress, ‘man’s treasury, the source of the increase of man’s -
wealth. Navigation by stored food and the LITTLE POINTER
was made safe and pleasant.”

This passage occurs several times in the inscription.
The “ttle pointer and the stored food are described as the
means by which the three western islands had been dis-
covered.

The events of former voyages are described very em-
phatically: on one occasion, it appears, the ships had gone
so far north that the water skins had been frozen and burst,
and they fell in with what they supposed to be land, but
found, on examination, to their great consternation it was
only ice.

They proceeded with cautious anxiety by means of the
sun by day and the seven (reacd pe, ursa major) by night ;
and at length saw the land of the three islands; on the first
of which they saw sheep.

The concluding passage of the seventh table reminds
the Pheenicians, (for although these people were certainly
resident in Italy, they are throughout called PUND), that
the island country which had been discovered would form
a noble country for trade, protected from hostile aggression
by the sea; and might hereafter become an asylum (in case
their own country should be invaded and conquered by an
enemy of robbing people) to which they might retire in their
ships, and where their friends and colonists would receive
them with joy and gratitude in return for the benefits they
had conferred upon them.

In the last paragraph we are informed that the inscrip-
tion was written after three hundred years from the great
subterraneous noise and commotion, or the earthquake.

Of the former unsuccessful attempts to decipher these
very interesting inscriptions, Sir William Betham referred
to that of Father Gori, published with a fac simile, and that

130

of Lanzi,-in his Saggio di Lingua Etrusca, both of which,
he stated, were unsatisfactory, far-fetched, and absurd.

Mr. Samuel Ferguson read the first part ofa paper “ on
the Antiquity of the Kiliee, or Boomerang,” the object of
which was to show, that the peculiar characteristics of that
instrument belonged to the cateia and aclys of the Latin
classic writers, the latter being, most probably, identical with
the ancyle of the Greeks.

The chief proofs in the case of the cateia turned, Ist, on
the epithet panda applied to it by Silius Italicus, (Punic.
|. iii. v. 278,) and, 2nd, on the description of it given by
Isidore, a writer of the end of the sixth and beginning of
the seventh century, who states concerning it, “Si ab artifice
mittatur rursim redit ad eum qui misit.” (Origin. 1. xviii.
c. 7.)

The chief proofs in the case of the aclys, rested, Ist, on
the identification of the aclys and cateia, by Servius {in
fMneid. 1. vii. v.'730, 741); 2nd, on an inference of its semi-
lunar shape, drawn from Valerius Flaccus, (Argonaut. 1. vi.
v. 99); and 3rd, on the statement of Sidonius Appollinaris,
a writer of the fifth century, who, referring, as it would ap-
pear, to these weapons, describes them as missiles, “ que
feriant bis missa semel.” (Carm. V. v. 402.)

The identity of the aclys and ancyle was inferred from
their apparent etymological relation, and from the statement
of the Scholiast on Euripides—ayxvAa ra axovria, aro Tov
exnykvdacba, (Euripid. Orest. v. 1479).

An investigation of the radical meanings of these names
confirmed the testimonies adduced, by showing that each
was properly descriptive of a curved instrument.

The statement of Isidore, that the cateta and club of
Hercules were the same, was, in like manner, confirmed by
an investigation of the radical meaning of the word clava, and
by the exhibition of drawings of curved clave (almost identi-

131

cal inform with a variety of the Australian instrument) taken
from the antique, one of which appeared to have been in-
tended to represent the Herculean weapon. A further con-
firmation was drawn from the fact, that instruments, formed
on the model of these, were found to exhibit the peculiar
flight of the boomerang. So also of the club or hammer of
Thor, the Hercules of Scandinavian mythology, stated in
the Edda to have possessed similar properties ; instruments
of a +, and hammer shape, being also found to exhibit all
the peculiarities of the Australian weapon. Hence, an
illustration of the crosses on Pagan British coins, and of
the tradition of cruciform missiles still preserved in Irish
romances.

The connexion between the curved club and the boome-
rang being thus established, it was suggested, that some
relationship might be looked for between the Germanic
nations, who still call their club setle and kiele, a name
properly descriptive of a crooked weapon, and the Austra-
lian tribes who call the cognate instrument iéliee.

From the remarkable fact, that the-names of the straight
spear in several of the languages of Europe are either iden-
tical, or radically connected, with these characteristic names
of the crooked missile, it was argued that the boomerang is
a more ancient weapon than the spear.

DONATIONS.

Astronomical Observations made at the Observatory of
Cambridge. By the Rev. James Challis, M. A. Vol. IX.,
for the year 1836. Presented by the Author.

Address of His Royal Highness the Duke of Sussex,
K. G., §c. Sc. §c., the President, read at the Anniversary
Meeting of the Royal Society on Thursday, November 30th,
1837. Presented by the Society.

Guilielmi Gilberti, de Magnete, Magneticisque Corpori-
bus, et de Magno Magnete Tellure ; Physiologia nova, plu-

132

rimis et argumentis, et Experimentis demonstrata. Fol. Lond-
1600. Presented by Aquilla Smith, M. D.

Nouveaux Mémoires de 0 Académie Royale des Sciences
et Belles-Lettres de Bruxelles. Tom. X. Presented by the
Royal Academy of Brussels.

Mémoires Couronnés par l Académie Royale des Sciences
et Belles-Lettres de Bruxelles. Tom. XI. Presented by
the same.

Bulletin de 1 Academie Royale des Sciences et Belles-
Lettres de Bruxelles, 1837. Nos. 1to9. Presented by the
same.

Programme des Questions proposées pour le Concours de
1838, par l Académie Royale des Sciences et Belles-Lettres de
Bruxelles. 3 copies. Presented by the same.

Annales de Observatoire de Bruxelles, publieés aux
frais de ’Etat. Par le directeur, A. Quetelet. Tom. I.
Deuxiéme Partie. Presented by the Author.

Comptes Rendus Hebdomadaires des Séances de l Académie
des Sciences. Par MM. les Secretaires Perpetuels. Deux-
ieme Semestre, 1837. Nos. 1 to 26. Presented by the
Academy.

February 12.

SIR Wm. R. HAMILTON, A. M., President, in the Chair.

The following gentlemen were elected Members of the
Academy :

John Anster, LL.D., Joseph Carson, Esq., F.T.C.,
Mountiford Longfield, LL.D., Robert Caldwell, Esq.,
Alexander Boyle, Esq., Thomas Drummond, Esq., John
Hamilton, Esq., Rev. George Vernon, Rev. Robert Knox,
James Whiteside, Esq.

133

Mr. S. Ferguson read the continuation of his paper on
the Antiquity of the ‘“‘ Boomerang.” The author exhibited
a tabular digest of the significant synonymes of a variety of
words, all of them necessarily involving the idea of curva-
ture. These he arranged according to their palpable re-
semblances ; and gave it as his opinion, that the indices or
characteristic syllables of the classes so resulting were uni-
formly identical with the roots of the names by which the
curved weapon and spear have been known.

Mr. Ferguson stated, that the transit of these names
from the one class of weapons to the other, appears to have
taken place through the medium of the amentum, or attached
sling, by which the spear was originally thrown. He sug-
gested a similar mode of throwing the Australian instrument,
and illustrated it from a British coin of Cunobeline.

From an investigation of the relations observable among
the nations which appear to have used weapons of this de-
scription, the author concluded that the use of them in
Europe was in great measure peculiar to the Gomarite
branch of the Japetian family.

DONATIONS.

Comptes Rendus Hebdomaduaires des Séances de l’ Aca-
demie des Sciénces. Premier Semestre, 1838. Nos. 1, 2, 3,
and Tables Alphabetiques. Jan.—Jun. 1837. Presented by
the Academy.

The Phrenological Journal and Magazine of Moral
Science. Vol. XI. No. 44. New Series, No. 1. Presented
by the Phrenological Society.

Ordnance Survey of the County of Londonderry. Colonel
Colby, R.E., F. R.S. L. and E., M. R. I. A., Superintendant.
Volume the First. 4to. Presented by his Excellency the
Lord Lieutenant. .

The Ordnance Maps of the Counties of Sligo, in 49 sheets:

134
and Longford in 29 sheets: each including the Title and
Index. Presented by His Excellency the Lord Lieu-
tenant.
Flora Batava. 4to, Amst. 1836. Nos. 110, 111. By

Jan Koops and H.C. Van'Hall. Presented by the Au-
thors.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1838. No. 10.

February 26.

SIR Wm. R. HAMILTON, A.M., President, in the Chair.

Tue Rev. Dr. Mac Donnett, Secretary of Council, gave
notice that it was his intention to resign his Office of Secre-
tary, and place in the Council.

A letter was read from Dr. Ferguson, resigning his place
in the Council.

The recommendation of Council to repeal the latter part
of Chap. VIII. sect. 4, of the Statutes of the Academy, from
the words “‘ except by a vote,” to the end, was agreed to.

The Rev. J. H. Todd exhibited the original of a Charter
granted to the Abbey of Mellifont, near Drogheda, in the
county Louth, by John, son of Henry II., afterwards king of
England. The charter was given at Castleknock, but the
year is not specified. It must, however, have been the year
1185, when John, by confirmation of Pope Urban VIII. was
appointed by his father, Lord of Ireland, (Hoved. fol. 359. d.)
whither he accordingly went soon after, accompanied by 400
knights, some archers, and many clerks, (clerici plures,) one
of whom was Giraldus Cambrensis, who tells us of himself
that he was specialius a patre cum filio directus, (Gir. Cambr.
cap. 31, Hoved. fol. 360.) John was not quite a year altoge-
ther in Ireland, having been compelled to abandon the

oO

136

country in consequence of the offence he gave to the chief-
tains of the Pale. The date of the charter is therefore
sufficiently ascertained ; in it John assumes the title of Do-
minus Hibernia, the same which was adopted before by his
father, and held by all the kings of England since that period
to Henry VIII. But it is remarkable that he lays claim to
the exercise of an independent sovereignty ; the object of
the charter being to confirm a previous charter granted by
the king of England. Archdall appears to have seen this
charter, but has given an imperfect and very inaccurate
copy of it, (Monast. Hib. p. 480.)

Mr. Todd also read a letter from Col. Currey of Lismore
Castle, consenting to lend the Academy the ancient MS.
found in 1811, buried under the ruins of the Castle. The
MS., according to Mr. O’Reilly, was written in the latter
end of the 15th century ; the writing is exactly similar to
that of the Book of Fermoy, written in 1487, and both
volumes were probably the work of the same scribe. The
Book of Lismore contains poems and historical treatises
relating to the M‘Carthys,—lives of saints,—the wars of
Callaghan of Cashel,—the adventures of Teige Mac Cein, and
the battle of Druim-damhghoire ; also a very valuable tract
giving an account of the battle of Gabhra.

The thanks of the Academy were voted to Colonel
Currey.

Professor Lloyd, V.P. read the following communication,
contained in a letter from M. Abbadie, detailing the principal
results of his scientific expedition to the Brazils. The letter
is dated the 31st of August, 1837; and Mr. Lloyd regretted
that he had no earlier opportunity of laying it before the
Academy.

TJ availed myself of the departure of a young friend for
Ireland to write to you before my departure for the Brazils,
announcing the purport of my voyage, and sending at the
same time a copy of my remarks on the Euskara language,

137

which I offered to the Royal Irish Academy. I should be
glad to learn that it has proved acceptable, however trifling.

** As I have always remarked that scientific discoveries
are long known either in Ireland or in France, before they
travel from one country to the other, I think it may be
gratifying to you to become acquainted with a few parti-
culars of my voyage.

‘¢ We made three observations every hour, day and night,
from the 11th of February to the end of March. The in-
struments examined were, Ist, the horizontal magnetic
needle; 2nd, the thermometer; 3rd, the barometer, @
niveau constant; 4th, Saussure’s hair hygrometer. The
direction and force of the wind, state of sky, &c. were also
observed.

“The variations of the needle were far greater than in
Paris; the hours of maxima and minima agreeing very well
together, except near the time of the sun’s passage through
the zenith of Olinda, (lat. 8°. 0’. 58”. long. 2" 19" W.) I
then remarked two important phenomena; Ist, the extreme
digressions, A.M. in one sense, became P.M. in the same
direction, when the sun began to culminate in the other
hemisphere, after passing through the zenith. 2ndly, this
remarkable alteration was preceded by sudden and perma-
nent changes in the variation of the needle, amounting to
more than one degree. The first of these variations took
place twelve hours after the sun’s centre had reached a
declination equal to the latitude of the place. All these
sudden changes were accompanied with feeble storms con-
fined to one small part of the horizon. Referring to the
problem as laid down in the Annuaire du Bureau des Longi-
tudes for last year, it would seem that the transition from
the daily variations belonging to the northern hemisphere to
those which characterize the southern part of our globe, is
not on the magnetic equator, but depends on the sun’s path
in the heavens; and the sun acts here not as a source of

02

138

heat, according to Captain Duperrey’s supposition, but as a
source or centre of magnetic attraction, if I may dare say so
in the present uncertain state of science.

“The mean results of the observations made by us on
magnetic intensity of forces, confirm very nearly the ratio
between the equator and our latitudes, as first given by our
distinguished countryman Captain Sabine. The dip was
13°. 9’. but varied a little under the sun’s influence.

““The maxima and minima of the barometer’s range,
confirmed partly M. Boussingalt’s results.

“The mean temperature of the place, as given, Ist, by
the daily observation of the thermometer; 2nd, the heat of
springs; and 3rd, that of the ground at small depths, was
27.5 grades; nevertheless, the bottom of an Artesian well,
200 feet deep, was 24.0 grades, being much colder than at
the surface. ‘This was measured three times, as it seemed
contrary to our received theories on a geocentric focus of
heat.

“M. Selligue of Paris, has succeeded in making a
folding iron barometer, which has been observed every day
after a thorough shaking. It has not altered its primitive
error of .001 metre. I confess that I am rather sanguine
about this instrument, which I shall carry with me to Egypt
and beyond the Red Sea.”

M. Abbadie is at present in Abyssinia, whence he will
proceed along the shores of the Red Sea.

Professor Lloyd communicated to the Academy the
results of his observations on the diurnal march of the
horizontal needle, made on the 31st of August and 13th of
November, 1837.

These observations having been made with the apparatus
of Professor Gauss, Mr. Lloyd commenced by describing
the construction and uses of that apparatus, the principal
parts of which he exhibited to the Academy. He then ex-

139

plained the system of combined observation carried on
under the auspices of that distinguished geometer, at so
many places in Europe, and now, through the instrumen-
tality of the Russian government, extended over the whole
of northern Asia, and reaching even unto China. The
results of this system hitherto obtained are, Ist, that the
direction of the terrestrial magnetic force (estimated in the
horizontal plane) is subject not only to a regular diurnal
change, whose maxima and minima return at fixed hours;
but also to irregular perturbations, which succeed one
another with great rapidity, and which are not periodic.
2ndly. That these irregular movements of the horizontal
needle occur at the same instants of absolute time, and are
similar to one another, at the most distant places at which
observations have been hitherto made. ‘This synchronism
in the movements of the needle, Mr. Lloyd observed, was
so exact, that with the instrumental means now placed at the
disposal of observers by M. Gauss, he had no doubt but that
a very close approximation might be made to the determina-
tion of geographical longitudes.

Professor Lloyd then proceeded to lay before the
Academy the results of the observations made in Dublin
according to the methods described. The first series of such
observations was made every five minutes during the twenty-
four hours, commencing at noon (Gottingen time) on the
3lst of August last. ‘The observations were undertaken in
compliance with the general invitation of Baron Humboldt,
and on the occasion of the scientific expedition of M. Parrot
to the North Cape. The results are laid down in curves,
according to the usual method of graphical representation,
and exhibit a remarkable disturbance occurring between 8
and 11 p. m. (Gottingen time). ‘The observations made at
the same time elsewhere are not yet published; but Mr.
Lloyd has, through the kindness of Baron Humboldt,
received a copy of the observations made at Berlin at the

140

same hours, under the superintendance of M. Encke, and
the agreement is very remarkable.

The second series of observations was made every five
minutes during the twenty-four hours, commencing at noon
(Gottingen time) on the 13th of November last. These ob-
servations were undertaken at the request of Baron Hum-
boldt, and with the view of ascertaining whether there existed
any connexion between these perturbations of the needle, and
the meteoric displays, which have been supposed to recur at
that period in unusual frequency. The observations do not
exhibit any very marked magnetic phenomenon; but on the
following evening (November 14th) the needle was disturbed
in a most unusual manner. It oscillated in very large arcs,
and the maxima and minima of mean position succeeded one
another with great rapidity. The whole range of the dis-
turbance amounted to 1°. 20’.

The nights of the 12th, 13th, and 14th of November
were cloudy in Dublin, and no meteors were observed.

Mr. Petrie gave an account of a very remarkable collec-
tion of stone circles, cairns, &c. situate in the townland of
Carrowmore, in the parish of Kilmacowen, and about two
miles from the town of Sligo. They are of the class popu-
larly called Druidical Temples, and have, in every instance,
one or more Cromlech or Kistvaen within them. In some
instances the circle consists of a single range of stones,
in others of two concentric ranges, and in a few instances of
three such ranges ; and nearly the whole are clustered toge-
ther in an irregularly circular manner, around a great cairn,
or conical heap of stones, which forms the centre of the
group. The circles vary much in diameter, number, and
height of stones, and other particulars; and the Cromlechs
also are of various sizes and forms. Many of these monu-
ments are greatly dilapidated; but there are still existing
vestiges of about sixty circles with Cromlechs, and as it is

141

known that a vast number has been totally destroyed by the
peasantry, there is reason to believe that the collection
could not have been originally much less than double that
number. They are all formed of granite bolders, except the
covering stone and another of the Cromlech in the great
cairn, which are of lime stone.

In all the circles, which have been either wholly or in
part destroyed, human bones, earthen urns, &c. have been
invariably found; and one circular enclosure, outside the
group, and of far greater extent than any of the others, but
evidently of cotemporaneous construction, is filled with
bones of men and animals.

Mr. Petrie stated, that this is the largest collection of
monuments of the kind in the British islands, and probably,
with the exception of the monuments at Carnach in Brittany,
the most remarkable in the world.

From the design observable in their arrangement and
uniformity of construction, he considers them all of cotem-
poraneous age; and from the human remains found in all
of them, he concludes that they are wholly of sepulchral
origin, and erected as monuments to men of various degrees
of rank slain in a battle, the great central cairn being the
sepulchre of the chief, and the great enclosure outside the
group, the burial place of the inferior class. Such monu-
ments, he stated, are found on all the battle fields recorded
in Irish history, as the scenes of contest between the Belgian
or Firvolg and the Tuatha de Danann colonies, and he con-
siders these monuments to be the tombs of the Belgians,
who, after their defeat in the battle of the Southern Moy-
Turey, had retreated to Cuil-Iorra, and were there again
defeated, and their king, Eochy, slain in crossing the strand
of Ballysadare Bay, on which a cairn, rising above high
water, still marks the spot on which he fell.

As monuments of this class are found not only in most
countries of Europe, but also in the Kast, Mr. Petrie thinks

142

their investigation will form an important accessary to the
history of the Indo-European race, and also that such an
investigation will probably destroy the popular theories of
their having been temples and altars of the Druids.

March 16. (Stated Meeting.)

SIR Wm. R. HAMILTON, A. M., President, in the Chair.

This being the day appointed by Charter for the annual
election, the following Officers and Members of Council were
chosen for the ensuing year:

President—Professor Sir Wm. Rowan Hamilton, A. M.

Treasurer—Thomas Herbert Orpen, M.D.

Secretary—Joseph Henderson Singer, D.D.

Secretary to Counci1—Rev. Humphrey Lloyd, A. M.

Secretary"of Foreign Correspondence—Sir Wm. Betham.

Librarian—Reyv. William Hamilton Drummond.

Committee of Science.

Rev. Franc Sadleir, D. D. Provost of Trinity College;
Rev. Humphrey Lloyd, A.M.; James Apjohn, M. D.; James
Mac Cullagh, Esq. A. M.; William Stokes,’ M. D.; Rev.
William Digby Sadleir, A.M.; Robert Ball, Esq.

Committee of Polite Literature.

His Grace the Archbishop of Dublin; Rev. Joseph H.
Singer, D. D.; Andrew Carmichael, Esq. ; Samuel Litton,
M. D.; Rev. William H. Drummond; Rey. Charles Richard
Elrington, D. D.; Rev. Charles William Wall, D. D.

Committee of Antiquities.

Thomas Herbert Orpen, M. D.; Sir William Betham ;
’ George Petrie, Esq.; Rev. Caesar Otway, A.B.; the Very

143

Rev. the Dean of St. Patrick’s; Rev. James Henthorn Todd
B.D.; Henry J. Monck Mason, Esq. LL. D.

The President under his hand and seal appointed the
following Vice-Presidents :

His Grace the Archbishop of Dublin; The Provost ;
Samuel Litton, M.D.; Rev. Humphrey Lloyd.

The Committee appointed to examine the Treasurer's
Accounts reported as follows:

‘‘Examined the above Account,* with the vouchers
produced, and found it to be correct ; and we find that there
is a balance in bank of £229 2s. 5d.; and in the Treasurer’s
hands £178 16s. 11d., making a total balance of £407 19s. 4d.
sterling.

** (Signed,)
‘* Franc SADLEIR,

© SAMUEL Litton.”
“6 Feb. 19th, 1838.”

** The Treasurer reports that there are the following por-
tions of Stock in the Bank of Ireland to the credit of the
Academy :

«© £1500 in 3 per Cent. Consols.

*¢ £1500 in 35 per Cent. Government Stock, being the

Cunningham Fund.
** (Signed,)
‘© FRANC SADLEIR.

“ SAMUEL Litton.
“ Dee. 31, 1837.”

The Dean of St. Patrick’s read a paper giving an account
of the Medals and Medallists connected with Ireland, from
the period of Charles the Second (when the first medal was
struck that had any reference to that kingdom) to the pre-

* Entered in the Treasurer’s Book.

144:

sent time. They were classed according to the different
reigns, and the events which they recorded were noticed.
Some biographical memoirs of the Mossops, father and-son,
were also introduced; individuals of whom but little is known,
even in Dublin, their native city, beyond those works which
have long been admired as worthy of the best days of the
medallic art.

Mr. Todd, for Mr. Petrie, read a paper by the late Dr.
West, “on the Ancient Geography of Gaul and the British
Isles.” The principal object of this paper is to ascertain
whether the Belge were of Teutonic or Celtic origin, and
whether they spoke a Gaelic, or Irish, or a Cumric or Welch
dialect of the Celtic; the author inclined to the opinion
that they were of Celtic origin, and spoke a dialect of the
Cumric, more resembling the Cornish than the Welsh, but
different from the Erse or Gaelic; he brought many curious
and valuable facts to support his theory.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de VAca-
demie des Sciences. Nos. 4, 5, 6,7, 8, for the year 18358.
Avec Tables Alphabetiques. Presented by the Institute.

Transactions of the Cambridge Philosophical Society.
Vol. VI. Part 2. Presented by the Society.

Flora. Batava. By Jan Koops and H. C. Van Hall. Nos.
112 and 113. Presented by the Authors.

Philosophical Transactions of the Royal Society of
London. For the year 1837. Parts 1 and 2. Presented
by the Society.

List of the Fellows of the Royal Society. November 30,
1837. Presented by the same.

Address of his Royal Highness the President of the Royal
Society, held at the Anniversary Meeting, November 30th,
1837. Presented by the same.

Abstracts of the Papers printed in the Philosophical

145

Transactions of the Royal Society of London, from 1830 to
1837, inclusive. Vol. III. 1830 to 1837. Presented by the
same.

Proceedings of the Royal Society of London. Nos. 28,
29, 50. Presented by the same.

Journal of the Royal Asiatic Society of Great Britain
and Ireland. No. 8. Presented by the Society.

Essays on Unexplained Phenomena. By Graham Hutch-
inson. Presented by the Author.

On the Functions of the Cerebellum, by Drs. Gall, Vimont,
and Broussais. Translated from the French by George
Combe. Also, Answers to the Objections urged against
Phrenology by Drs. Roget, Rudolphi, Prichard, and. Tiede-
mann. By George Combe and Dr. A. Combe. 8vo. Edin-
burgh, 1838. Presented by George Combe, Esq.

Bulletin de la Société Geologique de France. Tom. 1X.
Feuilles 1—5, 1837 @ 1838. Presented by the Society.

March 26. (Adjourned Meeting.)
SIR Wma. R. HAMILTON, A. M., President, in the Chair.

A paper, by Mr. Carroll, on the Motion of the Boomerang,
was read. In this paper the author seeks to explain the
properties of the flight of the weapon by assimilating the
effect of the air’s resistance on it to that exerted upon a flat
circular disc.

Professor Lloyd, V. P. made a few observations upon the
same subject, in which he endeavoured to show that the pe-
culiar movement of this projectile was but an extreme case
of acknowledged laws. Whena body moves in a resisting
medium, and when the resultant of all the forces of resis-
tance, which act upon the several portions of its surface, is
not contained in the vertical plane of projection, the body
must deviate from that plane. This is generally the case in

146

the motion of a body in a resisting medium. This effect of
the air’s resistance can be shown to be unusually great in the
case of a body (like the boomerang) composed of two straight
arms united at a large angle, and projected with a revolving
motion ; and hence the large resulting deviation in this case,
amounting (as is known) to 180°. Mr. Lloyd observed,
however, that this anomalous deviation was by no means
peculiar to a projectile of this form; and that there were
even other shapes which exhibited the property in a more
remarkable manner.

The other peculiarity in the hight of the boomerang,
namely, its alternating ascents and descents, were ascribed
by Mr. Lloyd to a nutation in the axis of revolution ; the in-
strument (on account of its flat shape) being compelled to
move in its own plane, which is also the plane of rotation.
The motions of translation and of rotation of a heavy body
in a resisting medium are not independent of one another, as
they are in vacuo ; and hence.the variations of the progres-
sive movement will produce corresponding variations both
in the velocity and direction of the rotation.

Professor Lloyd read a letter from Mr. Knox, detailing
some results of the performance of his rain-guage, during
the months of August, September, and October, and de-
scribing a mode in which these results were graphically
registered. The following is an extract :

“‘ Drawing from a centre eight lines, to correspond with
the cardinal and intermediate points, I take on each line
a space respectively proportional to the amount of rain that
has fallen from that point during any month; connecting the
point so taken, I get a curve (or rather an eight-sided
figure) which exhibits at one view both the amount and
character of the rain during the month. It also enables the
observer to compare one month with another, and likewise.
to get a mean curve for the season, which may be of great
use in determining local climate. It is probable that the

147

mean curve for the three winter months may have the same
character, if not the same magnitude, during different years.
The line for August, for example, has shot down far to the
S.W. which was owing to a few violent thunder storms
from that direction. The curves for September and October
have gone more to the west; and it is probable that in
Spring I shall find the curve extending more to the easterly
side of the compass, as our then prevailing winds are from
that quarter.

‘Another important thing with regard to climate may be
obtained by using this guage in conjunction with Whewell’s
anemometer; for by drawing in the same manner and on
the same paper, the amount of wind from each of the eight
points for any month, we may see at once the comparative
dryness or wetness of any wind, (I mean with regard to razn,
not vapour,) which the mere amount of rain from the dif-
ferent directions would not give.”

The following table exhibits the amount of rain during
the three months above mentioned :

August. | September.| October.

a |

Ss. 0.342 0.862 0.042
S.W. | 1.434 1.226 0.836
W. 0.214 0.954 1.021
N.W.| 0.052 0.572 0.251
N. 0.199 0.515 0.148
N.E. | 0.050 0.248 0.016
KE. 0.026 0.065 0.003

S. E. 0.080 0.195 0.019

Total| 2.397 4.637 2.336

A paper was read “on some Snow Crystals observed on
the 14th of January, 1838,” by William Thompson and
Robert Patterson, Esquires.

The crystals, which form the subject of this paper, were
observed by the authors among the ordinary snow-flakes, in

"148

a shower which fell at Belfast on the 14th of January ; the
crystals appearing to constitute fully one-third of the snow
that fell. Nineteen distinct forms were observed, and are
described in detail in the paper. Most of them are identical
with those delineated by Hooke, Nettis, and Scoresby; there
are some, however, which do not appear to have been before
observed. They all belonged to the ‘ lamellar,” or first of
the genera into which they are divided by Scoresby. The
size of the crystals generally exceeded considerably that
of those observed by the above-mentioned authors; their
average diameter being such that the naked eye could
readily discriminate the various figures, as they lay on a
dark ground. ¢

From the great variety of figures observed in the course
of a very limited time (a single hour) it is inferred by the
authors, in opposition to the opinion of Scoresby, that a
considerable range of temperature is not essential to the
production of very various forms.

The weather for some days previous had been frosty,
and the barometer gradually falling from about noon on the
12th. On the morning succeeding the day in which the
observations were made, there was snow, succeeded by
showers of sleet; and at noon a heavy rain set in, and con-
tinued without intermission the remainder of the day.

The President, in presenting the copy of the Arenarius
of Archimedes, described in the donations of this evening,
stated that he had intended to offer some remarks on that
relic of mathematical antiquity ; but announced that he con-
sidered it unnecessary to do so, on finding that his remarks
had been, to a great extent, anticipated by Professor Rigaud
of Oxford.

Professor Lloyd communicated the results of a paper
*‘on the Annual Decrease of the Dip in Dublin.”
It is well known that the dip has been diminishing in

149

Europe from the time of the earliest observations, and that
the rate of this diminution is not uniform. It is, accord-
ingly, a question of considerable interest and importance to
determine the precise amount of the annual decrease, for a
given epoch, at any station. Conceiving that the observa-
tions of dip in Dublin, though extending over a very limited
time (three years), were yet sufficiently numerous to furnish
a close approximation to this amount, the author has put
them together with that view. The observations are thrown
into five distinct groups, those of the same group having
been made nearly at the same time. The following are the
results :

Date. No. of Obs.) Dip.
I. | Oct. 21, 1833, 1 (0 PBA
II. | Sept. 9, 1834, 10 i
III.) Sept. 18, 1835, 16 MAS Gio.
IV.| April 25, 1836, 8 1 1°23%,,.9.
V. | Aug. 5, 1836, 4 CN ee a

The observations of M. Kupffer clearly show, that the
diminution of the dip is not uniform throughout the year ;
but that from December to May it is nearly stationary, the
whole diminution taking place in the remaining eight months,
For the convenience of calculation, we shall assume that the
diminution takes place at a uniform rate throughout these
eight months. It is evident then, that if 6 denote the wn-
known dip at an assumed epoch, the 1st of January, 1836;
6, the dip observed at any other time; 2 the number of
effective months in the interval; and «, the monthly decrease,
- each of the above results will furnish an equation of condi-
tion of the form

o+ne=sd.
Combining these five equations by the method of least
squares, we obtain two resulting equations which give the
most probable values of d and «. We thus find,
d= 71°. 3.84, eas OCG

150

Hence the annual decrease of the dip in Dublin (or 8.) is
2’, 38.

The close agreement of this result with that recently
deduced by Major Sabine, from his observations at the
Regent’s Park, is very remarkable. From these observa-
tions it appears that the dip has undergone a diminution of
39’ at London, in the interval between August 1821, and
November 1837, an interval of 16} years. The annual de-
crease, therefore, is 2’.40.

RESOLVED, on recommendation of the Council,—‘* That
as a first step towards the attainment of greater regularity
of payment by members in future, the five following de-
faulters, being deeply in arrear, be now excluded from the
Academy, and declared to be no longer members thereof;
but, asa measure of indulgence, that they be not sued at
law for their arrears :

Lied:
Henry Grattan Douglas, M. D., in arrear, 37 16 0
Thomas Little, M.D. . : 37 16 0
John L. Arabin, Esq. — 3312 0
Gerard Macklin, Esq. . : — 27 6 0
William Shaw Mason, Esq. . —— 23 2 0”

ReEsotvep,— That the portion of the By-law, Chapter
VII. Section 4, which forbids the commencement of a new
paper after 10 o'clock, be suspended for the present.”

DONATIONS.

Hortus Mauritianus, Par W. Bojer. 8°. Maurice, 1837.
Presented by Lord Glenelg.

Transactions of the Geological Society of London. Second
Series, Vol. V. Part the First. Presented by the Society.

The Greek Text of the Arenarius of Archimedes, believed
to have been edited by Dr. Moor of Glasgow. Presented,
through the President, by Professor Russell of Edinburgh.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1838. No. ll.

April 9.
SIR Wm. R. HAMILTON, A. M., President, in the Chair.

The following gentlemen ‘were elected members of the
Academy.

Simeon Hardy, Esq., Robert Adams, Esq., Captain
John Pitt Kennedy, George Digges Latouche, Hsq., Jacob
Owens, Esq., Charles T. Webber, Esq., Henry Barry, Esq.,
The Hon. James King, Elliot Warburton, Esq., George
Downes, E'sq., The Venerable the Archdeacon of Raphoe.

Sir William Betham read a letter from Dr. Hibbert
Ware, describing a cromlech near Bombay, in India. The
following are extracts :—

“‘ My chief motive for sending you two sketches of crom-
lechs, recently discovered by my son, Mr. William Hibbert
Ware, Assistant Surgeon, 2nd Foot, or Queen’s Royal, in
the East Indies, has a reference as much to the interest
which such a distant locality attaches to this very early spe-
cies of monument, as to the apparent use to which it is al-
leged to have been subservient. —

“In the admirable history of Ireland by Mr. Thomas
Moore, this interesting writer, while treating of cromlechs,
has adverted to the remarkable circumstance recorded in
Maundrel’s Travels, that a monument of this description was

P

found situated upon the Syrian coast, in the very region of
the Pheenicians themselves. He also alludes to the crom-
lechs which are affirmed, on the authority of Sir Richard
Colt Hoare, to have been discovered so far east as Mala-
bar. I have not the means at present of consulting this last
mentioned author’s History of Ancient Wiltshire, where the
account appears, but, happily, the drawings are copied into
the work of your late friend Mr. Godfrey Higgins, in his
‘Celtic Druids,’ who states, that ‘ it is remarkable Sir Richard
Hoare did not accompany the sketches with any observa-
tions ;’ but he properly adds, that ‘ this author’s character
is too well known to admit a suspicion of their genuineness.
To this remark I heartily subscribe, and if any doubt could
ever have existed on the subject, (of which I am not aware,)
it must be removed by the communication which I now send
you, being an extract of a letter, with drawings, from my
son, Mr. William Hibbert Ware, relative to cromlechs dis-
covered by him near Belgaum. The information is to the
following effect :

*«*T enclose you two sketches of remains which very much
resemble the cromlech of Kits Coty House in Kent. These
I accidentally stumbled upon in the course of a tiger hunt.
Into the composition of each of these monuments four stones
enter, which incline towards one another, and are surmounted
by one large horizontal stone. From an inquiry of the na-
tives, including information which I received upon the spot,
I learn that these remains are tombs of ancient date; and
hence, from analogy, equally reasonable with a supposition
entertained on the round towers of Ireland, it is probable
that such piles in England were erected more as sepulchral
stones than for other uses. It is affirmed, that the present
structures were never raised for religious purposes. The
height of the pile, shewn in sketch fig. 1, is eight feet, the
other dimensions being proportionally represented ; and this
estimation applies also to sketch fig. 2. Their composition
is greenstone.’

a nO Sox RANE WAP Se

“* Such is the information I have received relative to this
very remote locality assignable to the cromlech. Into any
theory of European and oriental intercourse which the fact
may suggest, I have no wish at present to enter.

“It is remarkable that the accounts given of these Indian
monuments, tend to a conclusion similar to that which is

P2

154

derived from the information you were so kind as to send me,
relative to a cromlech being found within a sepulchral cairn
at Phoenix Park, namely, that it was used for purposes of
interment. But the question is, if such a conclusion admit
of an universal application? The cromlech has been found
in the north of Europe, placed on the very summit of a se-
pulchral cairn, as Sjoborg, in his systematic work, has
pointed out, and in this case, it appears more like an occa-
sional appendix to the cairn, destined, from its peculiar
structure, to the celebration of sacrifices in honour of the
dead. Iam satisfied however, that the cromlech original-
ly subsisted most frequently independently of any cairn
whatever ; and if, in this isolated state, human ashes have
occasionally been discovered in connexion with it, other in-
stances might be cited, in which very careful excavations
have not afforded any evidence that this monument had a se-
pulchral use. A safer conclusion, therefore, remains, that
the cromlech was most frequently connected with purposes
of interment, although not necessarily so; and that in gene-
ral it was raised for sacrificial objects.”

Dr. Kane read a paper-on the sulphates and nitrates of
mercury, particularly the basic salts formed by ammonia.

In a former paper Dr. Kane had shewn, that by the ac-
tion of ammonia on the chlorides of mercury, there were
generated compounds involving the radical np, (amidogen,)
and the design of the present paper was to develope the
function of the ammoniacal element of the oxygen salts of that
metal. It was found, however, that from the diversity of the
results of former chemists regarding the common basic salts
of mercury, it became necessary to re-examine them in order
to establish some fixed points.to which the constitution of
the ammoniacal bodies might be referred.

Among the numerous formule which have been assigned
to Turbith mineral, Dr. Kane has found Hg 0, so;-++ 2g 0

155

to be correct, (ag= 101,4,) and there is no other subsulphate ;
the pure turbith, no matter how prepared, possessing that
constitution. By the action of ammonia on persulphate, or
on turbith mineral, there is generated a white powder,
which was submitted to most careful analysis, and gave the
formula Hgo.so; + 2Hg0 ++ Hg.NHy. wasfound. The proof that
the fourth atom of mercury in this body is not an oxide, is full
and positive, and hence Dr. Kane no longer retains the pa-
rallelism of theories used in his former memoir, as the ab-
sence of oxygen may now be considered as fully proved.

The crystallizable nitrate of the red oxide of mercury
has been found no; + 2ug 0 + 240, as the younger Mitsch-
erslich had stated ; and Dr. Kane’ shows that there are two
basic pernitrates, of which the one, yellow, is similar in com-
position to the basic nitrates of copper and bismuth, that is,
HO.NO; + dug 0, and the second, of a brick red colour, he is
disposed to consider as No;-++ Gugo, though it was found
exceedingly difficult to decide whether the compound did
not retain a trace of water.

It is known that for the composition of the white precipi-
tate, which is given by ammonia with pernitrate of mercury,
different results had been obtained by Mitscherslich and Sou-
beiran. These discrepancies have been reconciled by the
discovery that there are at least two, perhaps three precipi-
tates, almost identical in colour and properties, produced in’
this reaction, but which differ remarkably in their chemical
constitution. When the solutions are. cold, and the ammonia
not in excess, the white precipitate. has the composition
NH3.No; ++ 3ugo, the formula obtained by George Mitschers-
lich, but if the liquor be warmed, it becomes Hg.0.NO; ++
2ugo +HgNH. This modification is evidently that which
was analyzed by Soubeiran, for he found’ one atom of acid,
one of ammonia, and four of mercury, which ratio is quite true.
It will be at once’ seen that: the former body corresponds to

156

the yellow basic nitrate, the oxide ofhydrogen being replaced
by the amide of hydrogen. Thus

NH; = NHy.H = AdH.

HO.NO; ~-+ 3Hgo.

HAd.NO; + dHgO.

This view is remarkably corroborated by the fact, that
when a solution of nitrate of ammonia is poured on the yellow
basic nitrate, the white powder is formed, while nitric acid is
set free. Another remarkable case of combination is shewn
by comparing the powder formed by boiling the white preci-
pitate with two of those described: in this paper. Thus
there are

Hg.cl + 2ngo + Hgad.
Hg.SO, ++ 2Hgo + Hgad.
Hg.NOg + 2ug0 + Hgad.
To which may be added, the oxychloride
Hg.cl + 2ugo + Hgo.

When the white ammonia subnitrate is boiled with solu-
tion of ammonia, it dissolves, and a crystalline substance is
deposited of a very interesting nature. Its formula, by ana-
lysis, is

3 (NH4O.NO;) + 4Hg0,
But the circumstances under which it is formed rather in-
dicate for its rational formula the following :
(HgNO, + 2 HgO + HgAd) + 2 (NH,O.NO;) +2 Ho.

George Mitscherslich had already obtained a compound

of a similar nature, being
NH3NO; + 2 HZO = (HENO,g + 2 HgO + HgAd) + NH,O.NO;.

Passing to the nitrates of the black oxide of mercury,
Professor Kane has verified the analysis of George Mits-:
cherslich, of the two crystallized protonitrates; he then shews
that there exists one definite subnitrate of the black oxide,

ia

the yellow powder analyzed by Grouvelle. Dr. Kane finds
that this powder always retains an equivalent of water, that
its formula is Ho.No; +2 Hg».0, and that the grey subnitrates
which have heen noticed by some chemists, are impure mix-
tures of black oxide and the yellow powder. Dr. Kane
considers the nitrates of the black oxide of mercury to be
thus related :

First crystallized, = Hg2.0.No;-+ 2uo.
Yellow powder, = HO.NO; -+ 2HQ.9.0.

Second crystallized, = 2 no; + 3 ug...0-+ 3n0. A doublesalt.

Great difficulty was found in determining what specimen’
of Hahneman’s mercury should be considered as pure and fit
for analysis. Considering that the most important sources of
error tend to throw the value of mercury too high, Dr. Kane
derives his formula from the lowest number which he ob-
tained by analysis, and these numbers were given always
by the blackest and purest looking portions. He finds,
on these grounds, for the ammonia subnitrate of the black
oxide, the formula nH3.No; + 2 Hg.2.0. which is related to
the water subnitrate in a similar manner to what holds in
the corresponding compounds of the red oxide.

Thus, in this paper, two propositions are developed:
Ist. Increased evidence of the formation of metallic amides.
2nd. That ammonia as amide of hydrogen is capable of
replacing oxide of hydrogen in its various functions in the
quicksilver salts.

Professor Apjohn read a paper “on the Properties of
a new Voltaic Combination,” by Thomas Andrews M.D.,
Professor of Chemistry in the Belfast Institution.

The object of the author in this paper is to extend the_
results which he has already obtained on the influence of
voltaic circles upon the solution of the metals in nitric acid to_
the case of concentrated sulphuric acid. When a plate of

158

zinc is heated to the temperature of 240° cent. in sulphuric
acid, of the sp. gr. 1.847, it is dissolved with the rapid dis-
engagement of a mixture of hydrogen and sulphurous acid
gas; but when a similar plate, voltaically associated with a
platina wire, is introduced into the same acid, its rate of so-
lution is reduced to one-third of the other, no gas appears
at the zinc, and sulphurous acid, almost perfectly pure, sepa-
rates at the platina wire. Similar effects occur at other
temperatures, but the proportion between the quantity of
zine dissolved when alone, and when connected with platina,
varies with the temperature. A minute investigation is given
of the. effect of the distance between the metallic surfaces,
and of their relative extent. upon the solution of the zine, and.
the development of the electrical current; from which it
appears that, as'in common cases, the action on the zinc.was
increased hy diminishing the distance between the zinc and
platina in the liquid, but on the contrary, was diminished by
increasing the extent of the platina surface. The latter ano-
malous result is carefully examined and explained.

The influence of the contact of platina with the other
metals, resembles, in general, its effect: upon zinc, except in
the cases of mercury and arsenic, in which the solution does
not appear to be retarded in this way, nor is there almost
any gas evolved from the platina. ,

The general conclusion drawn by the author from all
his experiments is, that the formation ofa voltaic circle gene-
rally diminishes, and never increases chemical action, when
the liquid conductor is an oxy-acid of such a strength, that
the electro-positive metal is oxidized from the decomposi-
tions, not of the water, but of the acid itself.

Professor Mac Cullagh exhibited and described a new op-
tical instrument, intended chiefly for the purpose of making
experiments on the light reflected by metals. The instru-
ment consists of two hollow arms or tubes, moveable about

159

the centre, and in the plane, of a large divided circle, each arm
being provided with a Nicol’s eye-piece, or some equivalent
contrivance for polarizing light in a single plane ; while in one
arm, which is of course crooked, a Fresnel’s rhomb is interpos-
ed between the eye-piece and the centre of the circle. At
this centre is placed a stage for carrying the reflector, with
its plane perpendicular to the plane of the circle, and hav-
ing a motion to and fro for adjustment. Each eye-piece,
as well as the Fresnel’s rhomb, turns freely about the axis
of the arm to which it belongs, and is provided with a
small circle for measuring its angle of rotation. When the
two arms are set at equal angles with the reflector, and the
observer looks. through the crooked arm, he will see a light
admitted through the straight one; and then, by turning the
Fresnel’s rhomb, and the eye-piece next his eye, he will be
able, by means of their combined movements, to find a po-
sition in which the light will entirely disappear. An obser-
vation will then have been made; for the light, before its in-
cidence on the metal, is polarized in a given plane by the first
eye-piece ; but after reflexion from the metal, (as we know
from Sir David Brewster’s experiments,) it is elliptically po-
larized ; and our object is to determine the position and
species of the little ellipse in which the reflected vibration is
supposed to be performed. Now, the axes of this ellipse are
parallel and perpendicular to the principal plane of the
rhomb, when it is in the situation above described, where
the light completely disappears; and the ratio of the axes is
the tangent of the angle which that plane makes with the
principal section of the eye-piece next the eye. The angles
are read off from the divided circles; and thus, for any
angle of incidence, and any plane of primitive polarization,
we can at once ascertain the nature of the reflected elliptic
vibration. Professor Mac Cullagh mentioned, that the in-
strument was made last year with the view of testing certain
formule which he has proposed for the case of metallic re-

160

flexion, and which have been printed in vol. xviii. pp. 70,71,
of the Transactions of the Academy; but that he had not
yet found leisure to make the various adjustments which are
necessary in order to obtain satisfactory results with it. The
instrument is beautifully executed by Mr. Grubb, who him-
self contrived the subordinate mechanism, by which the re-
quisite movements are effected with perfect ease to the
observer.

The President read the first part of a paper by the Rev.
Dr. Hincks, on the Years and Cycles of the ancient
Egyptians.

The author’s object in this paper is to oppose the re-
ceived opinion, that the Egyptian year originally consisted of
360 days, and that at some epoch, on which learned men
are not agreed, five additional days were annexed to it, in
order to approximate more closely to the length of a solar
revolution. His own opinion is contained in the five follow-
ing propositions, which it is the business of his paper to
establish.

Ist. In the early part of the eighteenth century, before
the christian era, there occurred a marked chronological
epoch in Egypt.

2nd. Before this epoch the Egyptians used a year, of
which the commencement took place at a fixed season, and
the average length of which was consequently equal to the
tropical year ; while after this epoch, they used the wander-
ing year of 365 days.

3rd. Between this chronological epoch, and the year of
our Lord, 34, there elapsed six cycles of some sort or
other.

4th. The nature of these cycles was such, that in one
of them, the astronomical phenomenon which marked the
commencement of the old fixed year, travelled forward
through a fifth part of the wandering year, or 73 days; and

161

consequently, that in five such cycles, that phenomenon re-~
turned again to the commencement of the wandering year,
having taken place on every day of it.

5th, Thelength ofeach ofthe smaller cycles was 300 years,
consequently the epoch, when the wandering year was in-
troduced was 1767, B.C.; and the first day of the first year
was the 8th of November in that year, according to the pro-
leptic Julian reckoning.

Of the truth of the first two of these propositions, the
author stated that he had long been convinced ; the last three
were the result of an investigation recently suggested to him
by a reference to a passage in Tacitus, quoted in an article
on the pyramids, in Fraser’s Magazine for November, 1837.

ReEsoLveED,—That the thanks of the Academy be given to
His Excellency, the Lord Lieutenant, for his kindness in
forwarding the work of M. De Jonnés to the Academy.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de [’ Acade-

mie des Sciences ; Premier Semestre, Nos. 9 and 10. Presented
‘by the Institute.

Statistique de la Grande Bretagne et de PIrlande, avec’
une Carte, 1837 et 1838. Par Alex. Moreau de Jonnés.
Presented by the Author, by favour of the Lord Lieutenant.

Proceedings of the Royal Society of London, No. 31.
Presented by the Society.

Transactions of the Agricultural and Horticultural Soci-
ety of India.—1. Report on the Physical Condition of the As-
sam Tea Plant, with reference to Geological Structure, Soils,
and Climate. By John M‘Cleland Esq., Assistant Surgeon,
Bengal Establishment, and Member of the Asiatic and Medical
Societies of Calcutta. Presented by the author.

162

April 23rd, 1838.
SIR Wm. R. HAMILTON, A.M., President, in the Chair.

The President continued the reading of the paper by the
Rev. Dr. Hincks, on the Years and Cycles of the ancient
Egyptians. : 7

Dr. Apjohn communicated a paper upon the subject of
a new and very complicated compound, consisting of iodine,
iodide of potassium, and the essential oil of cinnamon.

This compound he stated to have been first observed in
the winter of 1837, in a solution prescribed by a medical
gentleman of this city, of iodine and iodide of potassium in
cinnamon water. It is best obtained by adding toa gallon of
cinnamon water four ounces of iodide of potassium, and’ forty
grains of iodine, dissolved in a minimum of cold water. Upon
admixture, the solution becomes turbid, and if the tempera-
rature be at or close to 32°, the deposit becomes crystalline,
and slowly subsides. ‘The properties of these crystals were
detailed, and a succinct account given of the different steps
of the process employed for effecting their analysis. .

As the result of a number of experiments, the author ar-.
rived at the following numbers, expressing the composition
of 100 parts of the compound.

Todide of potassium . 12.55
todines® usVitaival., 8s
Oilof cinnamon . . 59.31

100.
The-empirical formula deducible from these results is
IK + I5 + ©%,
in which cz represents Cis Hg 02, the atom of oil of cinnamon,

163

as determined by Dumas; and the most probable rational
formula he stated to be

IK +3 (1+ 7).
Calculating from this formula, its composition would be

Iodide of potassium . 12.26

Todine: «« 4+ ...:«,,.... « 2808
Oil of cinnamon . . 59.66
100.

This compound he considered interesting under many
points of view ; in consequence of its complexity, the peculi-
arities of its properties, and its presenting a case of in-
compatibility which had not been previously suspected.
Also, as suggesting means which would probably lead to
the production of an entire new series of substances hay-
ing an analogous composition.

Dr, Apjohn stated, that this compound had been brought
under his notice by Mr. Moore of Anne-street, and that he
and Mr. Moore had investigated conjointly its properties,
and the best process for obtaining it. Of the specimen exhi-
bited to the Academy, sixty-one grains were obtained from a
single gallon of cinnamon water.

Professor Lloyd read a paper “ on a Declination Instru-
ment, made for the Magnetical Observatory of Dublin.”
The instrument, which was made by Mr. Jones of London,
was laid upon the table of the Academy.

The principle employed in this apparatus is the well
known optical principle of the collimator of Kater. 'The
needle is a rectangular bar, twelve inches in length; it is
provided with three sliding pieces, one of which is at the
middle of the bar, the other two near the ends. To the for-
mer is attached the suspension thread; one of the latter car-
ries an achromatic lens, whose focal length is somewhat less
than the length of the bar; the other, which is to be adjusted

164

to the focus of the lens, contains a cross of wires. The rays
proceeding from the cross are, under these circumstances,
refracted parallel to one another, and to the line connecting
it with the centre of the lens,—which may be denominated
the line of collimation of the instrument. If, then, a teles-
cope be placed so as to receive any portion of this parallel
beam, the cross will be seen in the direction of the line just
mentioned ; and that, independently of the exact adjustment
of the telescope.

The frame-work of the apparatus consists of two pillars

of copper, firmly attached to a massive slab of marble-—
The height of the pillars is eighteen inches; they are con-
nected by two cross pieces of wood, one at the top, and the
other about five inches from the bottom. In the centre of
the top piece is the suspension apparatus, the plan of which
has been adopted from the torsion balance of Coulomb, as
described by M. Pouillet. It is provided with a divided
circle, for the purpose of determining the amount of torsion
of the thread, and of correcting it.
"The magnetic bar, suspended by parallel silk fibres, is
enclosed in.a rectangular wooden box, to preserve it from the
agitation of the air. A glass tube, between the two cross
pieces, surrounds the suspension thread, and completes the
enclosure of the instrument.

_ The box is entirely distinct from the rest of the appara-
tus ; itis made in two halves, which are joined at the sides by
dovetails ; so that it may be put on when the needle has been
fully adjusted. ‘There is a circular window at each end of
the box. That nearest the observer is made of parallel
glass ; and is contained in a frame which has a motion of
rotation in its own plane. By a revolution of 180°, the pris-
matic error, if any, is corrected. The window at the other
end of the box is for the purpose of illummation.: In.
order to determine the internal temperature, the box is
provided with a small thermometer, the bulb of which

165

is within, and the stem (bent at right angles) on the outside
front.

It is intended to employ this apparatus for three pur-
poses; namely, to determine, first, the magnetie declina-
tion; secondly, the periodical and the irregular variations
of the declination; thirdly, the corresponding variations
of the horizontal magnetic force.

In using the instrument in the determination of the declina-
tion, it is to be combined with the theodolite and the transit in-
strument. ‘The transit instrument is to be fixed close to the
southern window of the observatory; there being also an
aperture in the roof for the purpose of adjusting it to the
meridian by means of the pole star and 6 urse minoris. The
centre of the theodolite is placed, as nearly as possible, at the
point where the line of collimation of the transit instrument
intersects that of the magnetic bar. When an observation
is made, the telescope of the theodolite.is directed to the
lens of the magnetic collimator, and the vertical wire of the
latter is made to’ bisect the cross in the focus of the telescope.
When this is done, the line of collimation of the telescope
is parallel to that of the magnetic bar. But as the latter
line may not coincide with the magnetic axis of the bar, a
similar observation is to be made with the bar inverted; and
the mean of the two readings will obviously give the direc-
tion of the magnetic meridian, freed from the error of colli-
mation. ‘To determine the angle between this and the é¢rue
meridian, the transit telescope is to be turned over, and em-
ployed as a collimator. The telescope of the theodolite
being directed to its object glass, the middle wire in the focus
of the transit is to be observed, in the same manner as the wire
of the collimator bar was in the former part of the observa-
tion. The line of collimation of the theodolite telescope is
then in the true meridian; and the angle read = on the
limb is the supplement of the declination. —

Tn observing the diurnal and irregular variations of the

166

declination, the reference to the meridian is not required.
Here, therefore, the theodolite and transit instrument are un-
necessary, and the former will be replaced by a fixed teles-
cope, furnished with a finely divided micrometer scale in its
focus.

A similar apparatus serves for the determination of the
changes in the horizontal magnetic force. It is only neces-
sary to modify a little the suspension arrangement, and to
substitute for the single thread two equidistant threads ; as
in the torsion electrometer of Mr. Snow Harris. The needle
is then to be turned by the force of torsion, into a position
at right angles to the magnetic meridian; in which position
the momentum of the magnetic force is greatest. The
changes of position of the bar (read off as before by a fixed
telescope with a micrometer scale) will enable the observer
to deduce, by an easy formula, the corresponding changes of
the magnetic force. Professor Lloyd then entered into some
details connected with the theory of the instrument as thus
employed; and he showed in what manner it was to be ad-
justed, so that a given variation of the magnetic force might
produce the greatest variation in the position of the bar.

A paper was read by Edward 8S. Clarke, Esq., on an Im-
provement which he had lately made in the Sustaining Bat-
tery, and on the size proper to be given to the zinc element of
sustaining batteries in general.

The author alluded to the decline of voltaic power which
occurs during experiment, and ascribed to M. Becquerel the
credit of having assigned its true cause; referring it, as this
philosopher did, to a transfer of the decomposed substances
to the respective plates, in such a way as to produce secon-
dary currents moving in a direction reverse to the primary
current.

Mr. Clarke also alluded to the fact, that Becquerel was
the first person who, to remedy this evil, adopted, in 1829,

107
the use of a membranous partition, and two different liquids,
to separate the respective metals ; but added, that the form
this philosopher adopted was imperfect, in consequence of
the difficulty of affixing the membranous portion staunchly
to the sides of the square glass box which contained the
two different fluids.

The author, after referring to the sustaining battery of
Professor Daniel and to the modification of that appara-
tus adopted by Mr. Mullins, exhibited to the Academy a
battery which he had devised to remedy a defect affecting
all previous combinations, and in which each surface of the
hollow zinc cylinder had, as first recommended by Mr.
Wollaston, a surface of copper opposed to it. An account
was also given of several experiments which shewed the
advantage of his form in calorific and electro-magnetic ex-
periments. ;

Mr. Clarke’s improvement consists in attaching a ring of
zinc by zinc rivets to the top part of the outside of the hollow
cylinder of zinc used in the arrangement of Mr. Mullins,
and drawing a bladder over this cylinder, to which it is
secured by a cord to the ring ; and in replacing the earthen-
ware jar by a copper cylinder, which is furnished with a
mercury cup, as are also the zinc cylinder and the central
copper. The central copper and the outer copper case are
connected by a wire dipping into the cups. A solution of
sulphate of copper is poured, as well into the outer case of
copper, as into the bladder surrounding the central copper,
and muriate of ammonia into the bladder enlosing the zinc.

The author concluded by detailing some experiments,
tending to shew that, (contrary to the opinions of M. Mari-
anini and Mr. Mullins,) the maximum effect is obtained when
the surface of the zinc element is equal, or nearly so, to that
of the copper.

RESOLVED, on the recommendation of the Council,—That
Q

168

the by-law Chap. 7, Sect. 8, be repealed, and the following
substituted :

‘* The Council shall, from time to time, award medals, or
other honorary rewards, at their discretion.”

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de Acade-
mie des Sciences. Premier Semestre, Nos. 12 and 13. ‘Pre-
sented by the Institute.

Genealogical Tables of the Sovereigns of the World. By
the Rev. William Betham, of Stonham, Suffolk. Presented by
Sir William Betham.

ERRATUM
IN THE LAST NUMBER OF PROCEEDINGS.

Page 149, last line, for 0.27, read 0’.297.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1838. No. 12.

May 14.
SIR Ws. R. HAMILTON, A. M., President, in the Chair.

Henry Watson, Esq., William T. Kent, Esq., and John
Thompson Young, Esq., were elected members of the Royal
Irish Academy.

His Excellency, the Lord Lieutenant, attended the
meeting as a guest.

The President read the conclusion of the paper by
the Rev. Dr. Hincks, “‘on the Years and Cycles of the
ancient Egyptians.”

According to the views advocated in this paper, a lunisolar
cycle of 600 years was in use prior to the deluge, its epochs
being at the autumnal equinox in the years B. C. 3567,
2967, &c. The knowledge of this cycle was preserved by
Noah, and diffused through the different nations at the
dispersion. It was certainly used in Persia and in Egypt.
In the former country, the commencement of the year was
fixed at the vernal equinox by Jamshid; the epoch of this
change being 7th April, 2007 B. C., when 360 years of the
current cycle had elapsed. The Persian years were however
reckoned from the first day of the following cycle, that is,
from 6th Feb. 1767; between which and the era of Yez-
digerd (16th June, A. D. 632) there elapsed exactly 2400

years of 365 days, that being the form of yearintroduced by
R

170

Jamshid. In Egypt, the commencement of the year was
fixed at the time when the inundation of the Nile had
sufficiently abated to allow the operations of agriculture to
commence; and it was observed in the first instance rudely,
by a nilometer, but afterwards with greater accuracy by a
gnomon: the first day of the year being the first day in
which the meridian shadow of an object had attained to a
standard length ; which standard length appears from cal-
culation to have corresponded with a south declination of
about 121°. The solar year, intervening between the suc-
cessive occurrences of this phenomenon, was greater than
the mean tropical year, on account of the changes in the
equation of the sun’s centre, and in the obliquity of the
ecliptic; and is shewn to have been about 1767 B.C.,
neglecting the perturbations caused by the moon and planets,
365, 243246, differing little from 365,2433 ... which would be
its length, if the phenomenon gained a fifth part of a year,
in 300 years of 365 days. The Egyptians, observing this
equality, and being dissatisfied with the year that they for-
merly used, on account of the 366th day, which, occurring
in every fourth or fifth year, disordered their calendar,
resolved that with the next cycle they would limit the year
to 365 days, allowing no more intercalations. This change
they accordingly made, on the 8th Nov. 1767, from which date
they commenced not only a new lunisolar cycle of 600 solar
years, that is 6002 years of 365 days, but also a cycle of the
seasons, consisting of 1500 solar years, or 1501 years of 365
days. The recurrence of either of these cycles was ‘celebrated
as the return of a phoenix; and those mentioned by Tacitus,
as having occurred under Sesostris, Amasis, Ptolemy Philadel-
phus, and Tiberius, are fixed in the autumns of the proleptic
Julian years, 1167, 567 and 267 B. C., and A. D. 34, The
date thus assigned for the reign of Sesostris agrees with that
which Mr. Cullimore has deduced from the astronomical
sculptures on the memnonium. The great period of 3000

171
years being the least common multiple of the two cycles,

is mentioned by Herodotus as the apocatastatic period used
by the Egyptians.

Professor Kane read a paper “‘on the Theory of Ammo-
niacal Compounds.”

In this paper the author first noticed the various hypo-
theses which had been from time to time proposed to explain
the nature of the combinations formed by ammonia, and
adverted particularly to the remarkable fact discovered by
Mitscherlich, of the isomorphism of NH; + Ho with k.o, and
to the principle deduced by Dumas from the properties of
oxamide, that Nnu;, by losing an equivalent of hydrogen,
formed a compound resembling very closely, and capable of
replacing in combination, the simple bodies of the chlorine
group.

In the theory proposed by Dr. Kane, it is laid down as
the fundamental proposition, that ammonia nH; must be
represented as a compound of the body nu, and of hydrogen,
that is, that ammonia, as gas, is amiduret of hydrogen. The
hydrogen of this body, outside the radical, may be replaced
by the various metals, or by radicals of organic origin, and
hence the amide of potassium, of benzoyl, &c. These
amides, resembling remarkably the chlorides, may unite with
chlorides or oxides of the same, or of different metals, and’
hence the most general proposition, that in the great mass
of the various ammoniacal combinations, their real nature
assimilates them to complex metallic compounds, an amide of
hydrogen, or of a metal, having united with a chloride,
oxide, &e. of hydrogen, or of a metal.

Thus sal ammoniac is considered in this theory as a com-
pound of chloride of hydrogen with amide of hydrogen, and
the oxide of hydrogen, united with amide of hydrogen, forms
the basic element of the ordinary ammoniacal salts. In like
manner, chloride of mercury, united with amide of mercury:

R2

172

forms white precipitate, and calomel, united with the cor-
responding amiduret of mercury, forms the black powder de-
scribed by Dr. Kane ina former paper. A great series of salts
can likewise be obtained, which contain oxides of copper, of
nickel, or of zinc, replacing the oxide of hydrogen in the
ordinary ammoniacal salts; and so, in like manner, the amide
of hydrogen, being capable of replacing, and of being replaced
by, oxide of hydrogen in all its functions, there originates
the class of basic salts, in which oxide of hydrogen is
replaced by ammonia, or in which the hyperbasic equi-
valents of oxide are replaced by amides, or partly by amides
and partly by oxides of the same metal, or of hydrogen.

To this class is referred, in great part, by Dr. Kane, the
compounds formed by the absorption of ammoniacal gas, by
chlorides of various bodies; thus, chloride of phosphorus
and amide of hydrogen, chloride of tin and amide of hy-
drogen. In these bodies, the author stated, that one portion
of the ammonia was generally retained more powerfully than
the other, and this fact he considers to result from a dissimi-
larity of function in the various parts, similar to that which
Graham had already pointed out in water. Thus there is

1 — cucl + NH; +2 NH;
2— cucl + NH; -++ NH3. HO
3— cucl +NH;+ 2 HO
4—cucl + Ho 4+ 2HO
where the progress of the replacement is evident.

The compound nux3. Ho. replacing potash, the author con-
ceives that substituting for it metals of the same family, the
bodies NH3. cvo and zno. NH3, should be capable of the same
function ; and he adopts the view suggested by Graham, that
certain compounds of this kind may correspond to the or-
dinary double salts. Thus

CUO. S03 ++ NH3. CuO. S03 ++ 4 NH». H
corresponds to Cw, S03 ~-+- NH3 HO. S03; + 40.H
and. following out this view, along with those already de-

173

scribed, it becomes necessary to look upon the so-called
compound radicals in a new manner.

Assuming as proved, that nu3. Ho replaces Ko,‘and Nu; Hcl
replaces kc/, hence, NHy replaces k.; but NH, is NH)++-H-++H.
That is, a sub-amiduret of hydrogen, compounding to certain
suboxides and sub-chlorides. It may be isolated, but all that
the author asserts is, that wu3-+1Cl acts as K.cl. He considers
it impossible to avoid giving to wH3 + cw cl and NH3 + zn cl
the same rank, and hence the transition to ng NH2 + Hg Cl,
and similar combinations. He conceives that we cannot, in
the present state of our knowledge, assign to the bodies
NH; Cv, or Hg NH» Hg the title of compound radicals, or give
to them specific names, and, therefore, whilst he retains the
word ammonium as convenient, and looks to the isolation of
it, and to its resembling a sub-oxide, and not a metal, he
considers the oxide of ammonium as more properly an oxam-
ide of hydrogen, and sal ammoniac as a chloramide of hydro-
gen, asthe white precipitate is chloramide of mercury, and
so with various other bodies.

In the development of the theory of compound radicals,
which arose from the author’s investigations, two conse-
quences were obtained, viz., that the amide replacing oxide
of hydrogen, the bodies Ho.so; + HO, or cwo. S03 + HO,
assimilate themselves to Ho.s03 4+ NH3, OF Cw0.S03 -—+- NH3,
and thence the water designated saline in Graham’s me-
moir, forms, with the metallic oxide, a compound base, to
which the theory must eventually be applied ; and, secondly,
the further extension of the investigation shews the difficulty
of drawing a line between these and the proper basic salts,
of which a great number has been examined by Dr. Kane,
for the purpose of obtaining evidence on these points, and
the result has been, that such basic salts are constituted on
the same type as the neutral salts of the same family, the
water being replaced by oxide of a metal, and in many cases
the metallic oxide becomes likewise hydrated by combined

174

water; that the equivalents of oxide are not all retained by
the same force, and that if we grant to ammonium the title
of a compound radical, it becomes very difficult to refuse to
the basic salts, as a class, the position or title of neutral salts
of compound bases, of a nature nearly similar.

Mr. Petrie read a paper on “ancient Irish consecrated
Bells.”
In this paper the author has first endeavoured to ascer-
tain the period of the introduction of bells into Ireland, and
states, that though it is possible that they might have been
in use previously to the introduction of Christianity, he has
not found the smallest authority from which it could be
inferred that they were so. He next shews that there is
abundance of evidence to prove, that in and from St. Patrick’s
time, they were generally used for the services of the church,
and that the consecrated bells of the first teachers of
Christianity in Ireland were afterwards applied to various
superstitious purposes, of which he gives a great number of
examples, from the lives of the Irish saints, ancient historical
poems, annals, and other records. These bells were pre-
served in the churches to which they had originally belonged,
and were usually enshrined in cases of the most costly
materials and elaborate workmanship. The author proves that
many of these bells of the earliest Christian times, though '
hitherto unknown to the literary world, still remain in
Ireland; and he exhibited from his own museum a bell, which
is celebrated in Irish history, as one of the chief relics of
the people of the north of Ireland, namely, the Clog-
an-udhachta, or bell of St. Patrick’s will. He afterwards
exhibited drawings of several ancient bells, and among
others, of St. Senanus’s bell, called the golden bell, preserved
in the county of Clare, and the bell of Armagh, now in the
possession of Adam M‘Clean, Esq. of Belfast. This bell is
covered by a case, or shrine, of exquisite beauty of work-

175

manship, and the inscriptions on it shew that it was made at
the expense of Donald Mac Loughlin, King of Ireland, for
Donald [Mac Amalgaid,] Primate of Armagh, at the close of
the eleventh century. Thename of the hereditary keeper of the
bell is also inscribed on the cover, and it is remarkable that
it wasin the possession of one family from the period in
which the case was made until it passed into Mr. M‘Clean’s
hands. The names of the artists who made the case are
also given, from which it is proved to have been of Irish
manufacture.

All these bells are of a quadrangular ‘form, and vary in
height from four to fifteen inches; and that they are of the
antiquity assigned them by popular tradition the author
proves by a chain of historical notices, collected from the
Irish annals and other records.

DONATIONS..

Registrum Vulgariter nuncupatum, “ The Record of
Caernarvon ;” é codice MS. Harleiano 696. descriptum.
Printed by command of Her Majesty, under the direction of
the Commissioners on the Public Records. Presented by
the Commissioners. :

Rotuli Chartarum in Turri Londinensi. Accurante
Thoma Duffus Hardy, 8. 8. A. é Soc. Int. Templ. Lond.
Vol. 1, pars1. Ab anno MC. XCIX. ad annum MC. CXVI.
Printed by command of his Majesty, King William IV., under
the direction of the Commissioners on the Public Records.
Presented by the Commissioners.

General Report of the King in Count Jrom the
Honorable Board of Commissioners on the Public Records,
appointed by His Majesty King William IV., by a Commission
dated the 12th of March, in the first year of his reign; with
an Appendix and Index. Printed by command of His Majesty

176

King William IV., under the direction of the Commissioners
on the Public Records. Presented by the Commissioners.

Catalogue of the Library of the Society of Writers to the
Signet. In four parts, with a General Index. Printed for
the use of the Society. Presented by the Curators of the
Signet Library.

Medical and Physical Researches ; or, Original Memoirs
in Medicine, Surgery, Physiology, Geology, Zoology, and
Comparative Anatomy. By R. Harlan, M.D., F.L.S., Lond.
Presented by the author.

Comptes Rendus Hebdomadaires des Séances de lAca-
demie des Sciences. Par MM. les Secretaires perpetuels.
Premier Semestre, No. 13, 14, 15, 16, for 1838. Presented
by the Academy.

Abhandlungen der Kéniglhichen Akademie der Wissen-
schaften zu Berlin. Ausdem Jahre 1835. Presented by the
Royal Academy of Sciences, Berlin.

Preisfrage der Philosophisch. historischen Klasse der
Kéniglich. Preunischm Akademie der Wissenschaften fir
das Jahr 1839. Twocopies. Presented by the same.

Berichtiiber die zur Bekanntmachung geeigneten Verhand-
lungen der Konigl. Preuss. Akademie der Wissenschaften
zu Berlin. Erster Jahrgang, 1836, and Zweiter Jahrgang,
1837. Presented by the same.

Statique dela France ; publiée par le Ministre de travaux
publics, de Agriculture et du Commerce. Presented by
A. Moreau de Jonnés.

An Original Portrait of Sir, Isaac Newton, painted by
Wills. Presented by Rey. Prof. Lloyd, V. P.

177

May 28, 1838.
SIR Wm. R. HAMILTON, A.M., President, in the Chair.

Mr. Ball read a paper, by Wm. Thompson, V. P. Nat.
Hist. Society of Belfast, ‘on the Irish Hare.” (Lepus Hi-
bernicus.)

This paper commenced with a review of what has been
written on the subject of the Irish hare, from the time it was
brought under the notice of English zoologists in 1833, until
the present period. Mr. Thompson. stated, contrary to
what has been advanced, that the hare of England and
Scotland, and that of Ireland, have long been known to
differ ; and that in 1807 the difference in the fur of the two
species was alluded to as a matter of common notoriety, in
the MS. of the late John Templeton, Esq. He further
stated, that on account of their differing from the Irish
species, a number of hares were, upwards of thirty years
ago, brought from England, and turned out on the largest
of the Copeland Islands, off the county of Down, and that
many years since, the Irish hare was, for a similar reason,
introduced to the island of Islay, off the coast of Scotland.

The Lepus Hibernicus is considered distinct from all
described species. It exhibits, in several respects, characters
intermediate between the British hares, ZL. timidus and L. varia-
bilis, but considered generally, more nearly approximates to
the former animal.

The chief result of detailed measurements is shewn in the
superior length of the ears and tail of L. timidus, compared
with those of Z. Hibernicus. The former, or common hare,
displays greater diversity of colour on the head, ears, and
body, than the Irish species, which again exhibits greater
variety in that of the legs. The most obvious difference in
colour (and which has been unnoticed by authors, )is in the tail,

178

the upper surface of which is black in the LZ. timidus, and
white, tinged with greyish towards the base, in the Irish
species. On looking to their osteology, some slight differ-
ences are observable in the head; the comparatively more
horizontal direction of the lumbar vertebra in the Irish hare
is conspicuous, and likewise the relative shortness of its tail,
which, as first recorded by Mr. Eyton, contains three
vertebra less than that of the English species, 13 only being
possessed by the former, and 16 by the latter animal.

The occasional whiteness of fur in the Irish hare is
believed by the author to be a consequence of age, and not
regulated by the law that is understood to affect the Alpine
hare, which is considered to change its dark summer fur to
white at the commencement of every winter.

The economy and habits of the Irish hare, which generally
correspond with those of the common species, are, together
with a comparative description of form, colour, &c., very
fully detailed in this paper.

Mr. Robert Mallet read a paper “on an hitherto un-
observed Force of Elevation and Degradation.”

The author maintains, that the forces producing geologic
changes are either mechanical or chemical, and that the
reaction of these forces, when co-existent, as is usually the
case, often gives rise to a third order of forces, which may
be denominated molecular forces, or those which, without
altering the atomic composition of bodies, affect the arrange-
ment and aggregation of their particles—modify their specific
gravity—their action on light, heat, electricity, &c., and
produce the varied differences of ductility, hardness, brittle-
ness, &c. &c. While chemical and mechanical forces have
been applied to geology, those of this latter class have been
almost wholly overlooked.

Of the several known molecular forces, those producing
change of volume and of specific gravity are perhaps the

179

most important, (at least to the geologist,) acting through the
medium of heat, chemical combination, and crystallization.
The state of our knowledge of these, as a branch of physics,
is scanty and deficient, and was presented in the form of five
tables, shewing—

Ist. Bodies known to expand in volume by combination.

2nd. Bodies known to expand in volume on changing
their state of aggregation or arrangement.

3rd. Bodies known to contract in volume in combination.

4th. Bodies known to contract in volume in changing their
state of aggregation or arrangement.

5th. Bodies whose volume is /nown to remain unchanged
in combination.

After stating that these tables were only brought forward
as indicative of the class of forces proposed being treated
of, and pointing out some of the very singular facts which
they contain, of alteration of volume, and the immense force
with which it frequently takes place, the author proceeded
to apply the results of his own experimental determinations,
of change of volume, in solutions of chloride of calcium
and sulphate of soda, on mutual decomposition, and of the in-
termediate oxide of iron in passing to peroxide—to the salt
formation of England—and shewing, that if considered as a
chemical deposit, an elevation of the surface, of eight feet
six inches, will have been produced, by reason of this change
of volume only.

A case of observed expansion in volume, by further
oxidation of the blue marl, of the saliferous system, and
its remarkable effects, was brought forward, and analogy
shewn with the indurating marl forming the bottom of Lake
Superior. he effects of these swellings, in all directions
of a mass, in producing consolidation and integration of its
parts, is there pointed out.

The author then proceeds to apply this principle, to ac-
count for the formation of the contemporaneous quartz veins

180

in granite, which he does by shewing that the average
analysis of granite gives more quartz than is necessary to the
definite constitution of its ingredients; that these have crys-
tallized from fusion, in the order quartz, mica, fellspar: and
that by the successive expansion of each set of crystals, the
residual quartz has been pushed from the surfaces of cooling,
towards the central and hottest parts of the mass, there
forming quartz veins.

It is suggested; that the expansion produced by sudden
crystallization (of which instances are not wanting) may give
rise to earthquakes; that the exact filling of whyn dykes,
notwithstanding the contraction on cooling of the dyke and
its walls, must be due to the same cause. The principle is
then carried to the solution of some cases of atmospheric
degradation. The Yorkshire flagstone desquamates pa-
rallel to the wrought surface, and across its lamina. ‘This
arises from induration, and crystallization of its argillo-
calcareous cement, which increases in volume, and splits off
the desquamated portion. The same is the case with the
onion stone of the Causeway—both desquamate by air and
moisture, without the agency of frost. Lastly, it is shewn,
that this expansion in volume does not always necessarily
infer disruption.

The author intends his paper only as an indication of a
wide class of forces, as yet little considered or applied by
the geologist, and which, although from the present condition
of geology as a science they cannot be often estimated, must,
in its future progress, form an important element of connexion
in all its greater problems. :

Mr. Samuel Ferguson read a paper, entitled “ Remarks
on the late Publication of the Society of Northern Anti-
quaries.”

The object of this paper was to add some corroboratory .
evidences to the fact established in the Antiquitates

181

Americane, published by the Royal Society of Northern
Antiquaries, that the Irish had been acquainted with the
continent of North America previous to the time of
Columbus.

From the fact that at least two sorts of dye-woods were
known in Europe by the name of wood of Brazil, before the
discovery of the American continent, the author inferred
that Brazil was the name of an already discovered country,
from which these woods had been brought. But a country
of indefinite magnitude, called the island of Brazil, is found
marked in numerous maps, made before and about the time
of Columbus ; and from the position of this country in the
Atlantic, to the south-west of Ireland, it cannot be identified
with any other part of the world than the continent of North
America. Again, from its being represented as bounded, at
least on two sides, by the sea, and divided by a great river, it
appears to correspond more peculiarly with the southern states
of North America, between the Atlantic and the the river Mis-
sissipi. But this is Irland it Micka, or Great Ireland, the dis-
trict which the northern histories represent as inhabited by a
white Christian people, speaking a language like the Irish;
and logwood, which is often confounded with Brazil wood
by the earlier naturalists, grows as far north as these
latitudes.

Hence it was surmised, that possibly the precious mausur
wood, spoken of in the northern histories as having been
brought by the Scandinavians from America, may have been
one of the dye-woods known in Europe before the time of
Columbus, by the common name of Brazil wood.

Further, in one of the maps referred to, the island of
Brazil is represented south of another island, of indefinite
magnitude, called “ Mons Orins,” which would thus appear
to be referred to the position of the Scandinavian settlement
of Vineland. But in the state of Rhode Island, which the
Northern Antiquaries identify with part of the Vineland of

182

their histories, is a stone, covered with sculptures and
inscriptions of the ante-Columbian era, on which the word
ORINX, or as some read, ORINS, is the only one legible.

Again, the tradition of the island of O’Brazil is still
vividly preserved, both by the Irish and the Welsh, and it _
is by this name the latter indicate the country alleged to have
been discovered by their Madoc. So strong was the belief
in this tradition in Ireland, in the seventeenth century, that a
patent is said to have been taken out for the island, when it
should be discovered, and a pamphlet, purporting to be an ac-
count of its discovery, obtained circulation in London in 1675.

From these considerations the author inferred, that per-
haps the story of St. Brendan, who is said to have spent
seven years in the land of promise, at the other side of the
Atlantic, may not have been altogether without foundation,
and that if so, it is not improbable that Christianity may
have been introduced into the new world by Irish eccle-
siastics of the 6th century.

Professor Kane read a paper “ on the Ammoniacal and
other Basic Compounds of the Copper and Silver Families.”

Having verified Berzelius’ formula for the ammoniacal
sulphate of copper cu soz + 2 NH3 + Ho., Dr. Kane pointed
out, that, from the circumstances of its formation, and others,
the real formula must be (NH3HO + so3) + NH3.cwl; and
that by heat it loses NH3.Ho. and leaves a compound NH3.cu
o + so3.; by still more heat there remains 2 so; + 2 cu o
++ NH3 or CwO.So3. + (NH3.Cu 0) SO3. and by water there is
formed the ordinary basic sulphate cvo.so; + 8 cuo +4 Ho.

Dr. Kane describes likewise a new basic sulphate as so;
+ 8cuo-+ 12Ho0. and he arranges these two salts as

1 = cwo.so3cuo0 + 2(cuo + 2 Ho).
2 = cw0.so3. cu 0 + 6 (cuo +2 HO).
and seeks to establish an analogy with the ordinary salts of

the same family, as
ZnO. SO;HO + 6.HO and cw 0.S03.cu 0 + 6 cuwo

183

Dr. Kane found the ammoniacal chloride of copper te
be cucl +2 Nu; + Ho. or correctly, NH3. Hcl + NH3. Cwo.
By heat nu; Ho is lost, and there remains NH;.Hcucl. By
water there is generated a new basic chloride of copper,
having the formula cucl+4cuo+6Ho,. The common
Brunswick green cu cl-+ 3cuo-+4Ho, Dr. Kane has ob-
tained with 6 Ho in place of 4 Ho. and these oxychlorides he
considers as formed on the type of the ordinary chlorides,
combined with water, or with metallic oxides in other groups.

1—cu. cl +cuo +2 (cwo + 2 Ho)
2—cu cl + 3 (cu 0 + 2 HO)
38—cu cl +cuo + 38(cwo +2 HO).

When No. 2 is heated, it loses all water, but if then put
into contact with water, it regains 4Ho, and becomes perfect
Brunswick green No. 1. cu cl. cwo + 2 (cuo + 2Ho).

The second equivalent of oxide is, in these chlorine
bodies, much less forcibly held than in the sulphates, but
that it is differently related to the acid than the remaining
equivalents of oxide or of water is proved by a great variety
of facts.

The ammoniacal nitrate of copper has the formula cuo
NO; + 2 NH3. or (NH3.HO.) NOs + Cu NH». hence this body
contains, united with the copper, amidogen ; when heated it
explodes, the copper and amidogen burning in the nitrous
oxyde yielded by the nitrate of ammonia. To obtain some
analogical evidence regarding this. body, Dr. Kane re-ex-
amined the ammonia-sulphate and nitrate of silver, and found
George Mitscherlich’s results good. Dr. Kane, however,
writes the formulz .

1 — (NH3.HO), RO3 + Ag.NH»

2 — (NH3.HO) NO; + AY NHpo.
This last salt, when heated, gives a beautiful decomposition ;
the nitrate of ammonia fuses readily, and at a temperature
below that at which it decomposes, the amide of silver is
resolved into ammonia, nitrogen, and metallic silver, which

184

latter being deposited on the sides of the glass, from the
liquid nitrate of ammonia, gives a mirror surface equal to that
obtained by aldehyd.

On analyzing the ammoniacal compounds of nickel, Dr.
Kane found the results of Erdman completely verified; but
from the inferior affinity with which the ammonia was
retained, these compounds did not yield as positive results
as to their influence on theory, as those of the copper class.

A new substance, discovered in the course of these re-
searches, may be termed a fulminating copper. It is a blue
powder, decomposed by heat into metallic copper, water,
ammonia, and nitrogen. Its formula is 3cwo 4+ 2NH3 +6 Ho.

The examination of the zinc compounds has lead to the
discovery of a considerable number of new bodies. The
ammoniacal sulphate of zinc crystallized is

1 — zno.s03 + 2NH3 +3 HO
exposed to the air, it efflorescences losing Ho, and becomes

2 — 2n0.S03 + 2 (NH3.HO).
which, if heated, gives at 212°F.

3 — ZN0.S03 + (NH3-HO.)
but at dull redness loses still wH3.Ho and leaves z0.sS03.
If No. | be exposed longer to a moderate heat it loses
2 uo. and there remains,

4:— zno 80; +2 NH; -+ HO

if this be heated to 300°, it loses (Nu; HO) and there is
5 — Zn0.S03 4+- NH3.

which further gives by heat
6 — 2 (zno.so3) + NH3

from which the ammonia cannot be expelled without decom-
position- 3

Selecting from among these No. 2, for reduction to. its
rational formula, it becomes

(NH3.HO.) S03 + 20. (NH3.HO).

185

- Now the oxide of zinc from the sulphate being redissolved
by potash, there must be formed the similar compound

K.0.S03 ++ Z20,KO.

This cannot be obtained crystallized, for if the liquor be
evaporated there is deposited Ko.so3, and zvo.Ko remains dis-
solved ; from this, by exposure to the air, there are gradually
deposited small crystals, which Dr. Kane considers as being

K0.CO, + 2 0.CO2 + 2 HO.
but by heat there is carbonic acid given off, and a powder
insoluble in water is produced, the composition of which,
from Dr. Kane’s examination, appears to be

; KO.CO2 + ZN0.CO2 + 2 Zno.

It will be recollected, that the bicarbonate of potash is

KO.CO2 + HO.C03.

By treating the ammonia sulphate No. 3 or 5 by water,

there is obtained a basic sulphate, having the formula
Zn0.S03 + 6 zno + 12 Ho.

which, dried and exposed to the air, slakes, and gives
ZnO.S03 + 6 zno + 3 Ho.

This new salt has some remarkable relations to those already

known.

There are two ammonia chlorides of zinc.

No. 1, in pearly scales of a talcy lustre, consists of

zn cl + 2 NH; + HO,
and, when heated, gives off NH3.Ho. leaving NH3.zn cl. a white
powder.

No. 2 is in fine quadrangular prisms, brilliant lustre, con-
sisting of 2 zncl +2Nu3-++ Ho. or, as Dr. Kane considers,
zn.cl + (NH3HCl) +- NH3.zv0. which losing NH3.HO leaves
zncl + NH3zncl. a white mass, fusible, congealing into a
mass like gum, and volatilizable. This gummy mass is like-
wise obtained by heating NH zn cd.

s

186

There is generated by the action of water on these basic
ammoniacal compounds, an oxychloride of zinc of a very re-
markable character: it is—

zncl +6 zno + 12 Ho.
dried, it is reduced at 212° to 90 + and by 300° to 6 Ho.
By 500° all water is driven off, and there remains zn cl + 6
zno which exposed to the air absorbed 3Ho. Hence the
general expression is

zncl+-6zn0 + 3HO + 3HO + 3HO +3 HO
and comparing some similar chlorides, there is,
1 ca.cl + 6 Ho crystallized chloride of calcium.
2 zn cl + 62n 0 — basic chloride of zinc dry.
3H cl-+6HO — strong muriatic acid.
4 zn cl + 62Zn0 + 12 Ho — hydrated oxychloride of zinc.
5H cl-+6HOo + 12 Ho — muriatic acid with a constant
boiling point.
+ Another oxychloride, having the composition
zncl +9 zno + 15 HO

which dried and exposed to air, absorbs 6 Ho. Hence it
may best be considered as i

(zn cl +-6zn0 +120) +3(zn0 HO),
giving ultimately

(zncl 4-6 zn 0 +3 HO +3 (zn0 roe

Mr. Petrie then read the following Report, from the
Committee of Antiquities :—

At a meeting of the council, on Monday last, the Presi-
dent read the following letter, which he received from Mr.
Drummond, the Under Secretary of State.

Dublin Castle, May 19, 1838.
‘© My DEAR SIR,

“‘T am informed, that in levelling a
mound in the Phoenix Park, on the eastern flank of the

187

Hibernian School, an ancient tomb has been discovered,
which is of considerable interest, and fitted to throw much
light on the disputed question of the origin of ‘cromlechs.’
“T beg, therefore, to suggest, that a deputation from the
Royal Irish Academy should visit and examine this tomb.

‘IT am, my dear Sir,
* Very faithfully yours,
“'T., DRUMMOND.
“Sir Wm. Rowan Hamilton,

© be. Bo.”

In consequence of this communication, the council
appointed the Committee of Antiquities as a deputation from
the Academy, to examine and report on the circumstances
connected with this interesting discovery; and the Committee
accordingly, with the President and many other members,
assembled on the spot, on Wednesday last, and made the
examination, and ascertained the particulars of which they
now present their Report.

It appears that some days previously, the workmen em-
ployed in the improvements now making in the Park, under
the direction of the Commissioners of Woods and Forests,
had been removing an ancient tumulus, or sepulchral mound,
situated to the west of the Royal Hibernian School. This
mound was 120 feet in diameter, and 15 in height, and was
popularly known in the neighbouring village of Chapelizod
by the Irish appellation of Cnoc-maraidhe, a name which,
according to the best Irish scholars who have been consulted,
appears to signify the hill of the mariners. This tumulus
appears to be surrounded by several smaller ones, not yet
disturbed.

Within the tumulus, but at the distance of several yards
from the centre, the men discovered four small sepulchral
vases, containing ashes of burned bones. These urns were
enclosed within small stone kists, but were unfortunately

188
broken through want of care in the excavation. One of them,
however, is nearly perfect, having fortunately been saved
by Mr. Larcom, who was riding past the spot shortly after
their discovery.

These urns, which, as usual, are of baked clay, exhibit
a greater degree of taste in art than those commonly found,
particularly in one example, which is unfortunately broken,
and on which the ornaments are in relief.

Subsequently, in the centre of the mound, a tomb was
discovered, and the workmen were stopped from proceeding
further, in order that its examination might be directed by
the deputation from the Academy. That this course was a
judicious one, and led to discoveries interesting to anti-
quarian science, which would not otherwise have been made,
will appear from the following results.

oe =
a nt i
‘i th on |

ff ~ -

The tomb consists of a table, or covering stone, 6 feet
6 inches in length, from 3 feet 6 inches to 3 feet in breadth, and
14 inches in thickness. This stone rested on five supporting
stones, varying from 2 feet 6 inches to 1 foot 3 inches in
breadth, and about 2 feetinheight. Of these supporters there
was one which did not actually touch the covering stone,
a small stone, since removed, having been wedged between
it and the latter ; and there were five other stones, not used
for supports, but as forming the enclosure of the tomb. One

ee ee

189

of these, on the east side, was removed, that the interior
might be examined. The apertures formed by the irregula-
rities in the shapes of these stones were filled up by smaller
stones, placed against them, to prevent the stones and earth
of the tumulus from falling into the tomb. All these stones
are limestone, and, with the exception of the covering slab,
water-worn, and even the latter appears to be partly so.

In the recess thus enclosed, two perfect male human
skeletons were found, and also the tops of the femora of
another, and a single bone of an animal, supposed to be
that of a dog. The heads of the skeletons rested to the
north, and, as the enclosure is not of sufficient extent to
have permitted the bodies to lie at full length, they must
have been bent at the vertebrae, or at the lower joints. In
both skulls the teeth are nearly perfect, but the molars were
more worn in one than in the other.

Immediately under each skull was found collected toge-
ther a considerable quantity of small shells, common on our
coasts, and known to conchologists by the name of Nerita
littoralis. On examination, these shells were found to have
been rubbed down on the valve with a stone, to make a
second hole—for the purpose, as it appeared evident, of their
being strung to form necklaces; and a vegetable fibre,
serving this purpose, was also discovered, a portion of which
was through the shells.

A small fibula of bone, and a knife, or arrow-head, of
flint, were also found.

For the preservation of allthese interesting remains, which
His Excellency the Lord Lieutenant has presented to the
museum of the Academy now forming, the Academy are in-
debted to Mr. Drummond, and to the zealous exertions of
Mr. Larcom, who hashad acase made for their present safety.

How far the discovery of this tomb may contribute to
settle the disputed point among antiquaries, of the original
purpose of the cromlech, or whether this sepulchre properly

190

belongs to that class of monuments generally supposed to
have been altars, or that called kiswaens, which are ac-
knowledged to have been tombs, it is not for this Committee
collectively to express an opinion; but, from the rudeness of
the antiquities discovered within its enclosure, they may
venture to refer the date of its erection to the earliest period
of society in Ireland; and as it has been ascertained that
interments of different ages have been made within the
same tumulus, it may also be inferred, with every appearance
of probability, that the urns found within this mound, from the
superior degree of art exhibited in their ornaments and forma-
tion, should be attributed to a later age than the original
tomb.

The thanks of the Academy were voted to His Excellency
the Lord Lieutenant,

The thanks of the Academy were also voted to Mr.
Drummond and to Mr. Larcom.

DONATIONS.

Memoires de ? Academie Royale des Sciences Morales et
Politiques de V Institut de France. Tome 1, (2 Série.) Pre-
sented by the Academy.

Comptes Rendus Hebdomadaires des Séances de l Acade-
mic des Sciences; Par MM. les WSecretaires Perpetuels.
Premier Semestre. Nos. 17, 18, for 1838. Presented by the
Academy.

Journal of the Statistical Society of London. No. 1,
May 1838. Presented by the Society.

Proceedings of the Royal Society. Nos. 31, 32. Pre-
sented by the Society.

Transactions of the Historical and Literary Committee of
the American Philosophical Society, held at Philadelphia, for
promoting Useful Knowledge. Presented by the Society.

191

Catalogue of Circumpolar Stars, deduced from the obser-
vations of Stephen Groombridge, Esq. F. R.S., 8. R. A. Nap.
&c. §c. Reduced to January Ist, 1810. Kdited by George
Biddell Airy, Esq. A.M. Astronomer Royal. Printed at the
public expense, by the Lords Commissioners of the Admiralty.
Presented by the Lords Commissioners of the Admiralty,

The Ordnance Survey of the County of Roscommon, in
Jifty-eight sheets, including the Title and Index. Presented
by His Excellency the Lord Lieutenant,

FAGRORG

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PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1838. No. 138.

June LI.
SIR Wm. R. HAMILTON, A. M., President, in the Chair.

Godfrey Levinge, Esq., John H. Lecky, Esq., William
Brennan, Esq., and David Aher, Esq., were elected Mem-
bers of the Academy.

Dr. Kane read a notice “On the Action of Arseniu-
retted Hydrogen on Sulphate of Copper, and on the Manga-
nese Alum analysed by Dr. Apjohn.”

The author stated, that on passing dry arseniuret of hy-
drogen over dry sulphate of copper, it is absorbed with the
evolution of considerable heat; much water is evolved, and
a black mass is formed, which consists of sulphuric acid,
arsenic, and copper: the whole of the oxygen of the oxide
of copper being removed with the whole of the hydrogen of
the arseniuret of hydrogen. ‘The re-action is

3 (s03 + cz 0) (3s03 + As2 Cu)
= ==

4s =
(sy + 1) 8 (a0).
The formation of this body, appears to Dr. Kane to render
probable the idea that a quantity of arsenic equal to one-
5,4
3
metals may form compounds similar to oxides, and thus the

third of the double equivalent, i

= 25,13, combining with

body just noticed be a sulphate of that arseniuret of copper,
T

194

S03 + — cu. When this body .is put into contact with

water, sulphate of water is formed, and arseniuret of copper
deposited ; this arseniuret being likewise at once precipi-
tated, when arseniuret of hydrogen is passed into a solution
of sulphate of copper.

Dr. Kane found also, that when arseniuret of hydro-
gen is passed over chloride of copper, chloride of hydrogen
is set free, and the same arseniuret of copper is produced,

2 As 2 As

cl.cu + ai j2 ees 3 cu + clH.

In examining the constitution of the alum, the analysis of
which by Dr. Apjohn, was read to the Academy last winter,
Dr. Kane found that the water had been estimated by that
chemist a little too high; thus Dr. Apjohn gave 48,15, while
the true quantity amounts to 47,60. This small variation,
however, makes, according to Dr. Kane, an important dif-
ference in the theory of the body, as the number of equiva-
lents is reduced to 25 in place of 26: and Dr. Kane looks
upon the salt as composed of —

Sulphate of Manganese mzo.so3.Ho + 6 HO.
Sulphate of Alumina Al, 0; +3580; + 18 HO.

(Mn 0.HO) S03 + (Al, 03 + 3803) +6 HO + 18 Ho.

In a temperature of 212° this salt loses 18 Ho, and by 300°
six of the remaining atoms. The twenty-fifth atom is retained
up to 600°: and Dr. Kane looks upon this salt as a remarkable
case of the replacement of amide of hydrogen by an oxide of
the same class; he further stated that it was by this princi-
ple he was led to the repetition of Dr. Apjohn’s analysis.

Sir William Betham read a paper “on Etruscan Hand
Mirrors,” particularly that figured in Dempster’s posthumous
work De Etruria Regali, Vol. I. Tab. I, p. 78, from the ori-
ginal in the Cospian Museum at Bologna.

195

These mirrors have been found in great numbers in Italy,
as well in the sepulchral chambers of the Etruscans as in
other excavations. One side was polished for the mirror,
the other generally engraved with a representation of some
mythological allegory. That under consideration represented
the birth of Minerva.

The figures and inscriptions are reversed by the engra-
ver in Dempster’s plate.

The author suggests that most of the fables of the Greeks
and Romans are but mutilated versions of the allegorical em-
blems of a previous people, and that people the Etruscans,
who, as well as the Celts, were a Pheenician colony. The
Umbri have long been considered Celts, and if the Etruscans
were the same people, they also were Celts. The former, Sir
William thinks, were called Umbri from their locality, (om,
distant, by, hills); they inhabited the remote hilly country of
Italy.

In this allegory Tinia (Jupiter) is represented ina sitting
posture, with the thunderbolt, and the mystic rod in his
hands; above his head is the infant goddess, with a shield
on her left arm and a spearin her right ; before him stands a
dressed female figure, with arms elevated towards Minerva,
and from her mouth the word THAR, cap, (come,) as if inviting
the new-born deity. Behind this figure is a female nearly
naked, having but a shawl thrown round her middle, and
sandaled. In her left hand she holds an axe with a double
blade, resting on her shoulder ; before her are the words
SETH LANM, pee lanaim, (the hole I cut.) Behind Tinia is
another female figure nearly naked, with her arms around
the body of Jupiter, as if supporting him, and behind her the
word THALNA, tal na, (the axe ;) also a tree with a bird,
perhaps the eagle, upon it.

Sir William suggested this explanation of the allegory :
TI NIA, ei nia, the splendid being ; the great spirit, or Jupiter ;

12

196

IUD BI TER, (ud bi cep), day's great being, is represented as a
king or warrior, who by the axe of Bellona, the goddess or
allegorical representation of experience in war, concieves the
idea of military strategy, wisdom, and discipline, and pro-
duces it from his head ; and Minerva is thus the allegorical
representation of wisdom, firmness, and military discipline,
produced by the axe of Bellona, or experience in war.

The Greeks and Romans, substituting Vulcan’s axe for
Bellona’s, seem to have spoiled the elegance of the allegory,
unless they meant that armour was the perfection of warlike
preparation.

Sir William Betham read a paper ‘‘ on the Ancient Tomb
recently discovered in the Tumulus in the Phcenix Park.”

This paper is here inserted without any alteration or
abridgment.

“When the Report of the Committee of Antiquities on
sepulchral monuments recently discovered in the Phoenix
Park, was read to our last meeting by Mr. Petrie, I ven-
tured to object, at the moment, to the meaning therein as-
signed to the name of the hill Knock-Mary, (cnoc mapawe),
the hill of the Mariners. It struck me that the troubleand ex-
pense of time necessary to construct this monument were not
likely to have been expended on the bodies of two mariners,
and, therefore, 1 suggested, that the meaning was most pro-
bably cnoc ma pug, the hill of the good king, or meap pig, the
fortunate, lively, active, or successful prince ; either of which
characters appeared to me to suggest a more probable origin
ofthe name than that assigned in the Report of the Committee.

“The Rev. Mr. Otway stated, that the name of Knock-
maroon, another hill in the neighbourhood, had referenée to
mariners; and that certain hills in the neighbourhood of
Sligo, which he had recently visited, bore like names, and con-
tained similar monuments, though of much larger dimensions.

“These statements from individuals of acute judgment and

197

correct observation on such subjects, induced me to hesitate
as to the accuracy of my own conclusions, but did not con-
vince me of the correctness of theirs. I have since consi-
dered the subject more at leisure, and am now convinced
that neither of the opinions expressed at our last meeting
was correct.

‘But before I enter upon the question of the meaning of
the name, I shall say a few words on the probable period of
the erection of the monument itself, and of the people con-
cerned in its construction.

‘“‘ The circumstances and manner of its formation, as well
as the urns of unburned clay, the small flint knife, and other
considerations, convince me that the work was not constructed
by the Celtic Irish,—I mean the people whose language is now
called Irish, and spokenamong us,—but by a previous people
who inhabited the island at the first arrival of the Celts, and
were known by the name of Firbolgs, or Belge. The shells
which were found suggest a meaning for this name of that
people, which is, I believe, quite new, at least it is so to me.
The name of Firbolg has generally been rendered reap, a
man, bols, of a bag, pouch, or sack, and also bolg; a boat or
vessel made of the skins of animals, a coracle; but bollog is
also a shell, anda round shell, it is also a skull, or bone of the
head, intimating a similarity between the two things; the
nerite found in this sepulchre are exactly of this character,
and seem to indicate that these people were called, by their
Celtic conquerors, reap bollog, from the circumstance of their
wearing an abundance of those shells by way of ornament.
They also called them bmz vaoipe painted (or parti-coloured)
men, for the reason that they stained their bodies; hence
the name Britain, given to both the islands inhabited by
these people. Their descendants, who by retiring to the
north of Britain, were preserved from the annihilation which
those of the south suffered from the Celts, were called Picts,
or painted men, by the Romans. It may be, that while

198

the southern Britons were extirpated, those who inhabited
the different northern regions of modern Scotland were able
to preserve their independence, and were found by Agricola
under the name of Caledonians, a people who were ofa florid
complexion, and whose other features indicated a German
extraction.

“The Flint knives, daggers, arrow heads, spear heads,
stone hammers, and chisels, which have been found in
Treland, in great quantities, are soexactly similar in formand
character to those found in Funen, in Denmark, and figured
and published by the Northern Antiquarian Society, that
those figures on their plates might be taken as correct repre-
sentations of our Irish articles. A very remarkable instance
is to be found in a flint dagger in our own Museum, which
T now lay before the Academy, with the Danish plate, Den-
mark was the country of the Cimbri, the descendants of
the Caledonians: the Welsh have ever, and still call them-
selves by that name. The places in that part of Scotland, of
which the Picts last retained possession before their extir-
pation by the Scotch from Ireland, still abound in Welsh
denominations, and seem to me to offer unquestionable tes-
timony, when all these circumstances are taken together
with the occurrence of similar monuments in all the British
islands, and in Denmark, that they are of the Belgie or
Firbolg people ; and the Belgze and Cimbri were people of
the same primitive northern race, using stone weapons and
tools; perhaps the first inhabitants of these countries.

“ I now proceed to say a few words on the name of the hill
Knock Mary, and its adjoining neighbour, Knockmaroon.

“« These names being Celtic Irish, and in the language of
the nation which succeeded the people who constructed these
monuments, could have no reference to the individuals
buried, but must have been given to the things themselves,
and consequently must have been of a generic character,
and applicable generally. The Celtic Irish were the people

Sa. ae

199

who used bronze instruments, and consequently a people
more advanced in civilization than the Firbolgs, who built
these monuments and used instruments of flint, the most
primitive of all; they, however, knew the uses for which they
had been constructed, and that they were places or hills of
sepulture, and called them by that name cnoc mapb, or the
hill of the dead, and cnoc mapban, the hill of the dead bodies,
otherwise, the hill of burial.

* I cannot bring myself to believe that these monuments
were the work of the Danes of Dublin, of Christian times,
because the flint knife, and the rude urns of unbaked clay,
are indicative of a much earlier period. The Danes of
Dublin, and the Scandinavians of that period, were too
far advanced in civilization, to justify us in entertaining
such a notion as tenable for a moment; and, therefore, I
would refer this monument to a most remote antiquity, at
least of three thousand years, as certainly the Celtic in-
vasion must have taken place near fifteen hundred years
before our era.

“The character of this monument’of antiquity is alto-
gether similar to the Cromlech, and its undoubted sepul-
chral character would induce the conclusion that all crom-
lechs were sepulchral, and nothing more than chambers of
the dead. New Grange itself would, if denuded, give the
appearance of an immense specimen of the sepulchral
chamber. It might be worthy of consideration, whether
that or some other large tumulus should not have the earth
which conceals its structure removed, and the stones left as
a demonstrative exhibition: for myself, I think it would be
well worth the expense of such an undertaking, if other cir-
cumstances did not make it impracticable.

** The application of the term altar tothe Cromlech I have
long considered very problematical, and Druid’s altar still
more doubtful. Iam now nearly convinced that these monu-
ments are not Druidical or Celtic. We have no evidence

200

from history that the Celts ever sacrificed on such an altar,
or even built one; and it is not probable that Caesar and
other writers who treat of the Celts, would have passed over
so remarkable a fact, especially as Cesar, enters so minutely
into the ceremonies of the Druids and their religious rites.
To enter into this part of the subject fully, would occupy
more time and space, and interfere with other subjects which
are of more pressing interest to me at this time, but I may be
allowed just to observe in this place, for the reasons above
stated, that I consider all cromlechs as denuded sepulchral
chambers, and that they are the works of the Cymbric Belgz.
I think the evidence we possess on the subject, all tends to
induce that conclusion.”

Sir William Betham read “ A Translation of the fifth Eu-
gubian Table,” as numbered by Dempster.

He stated that he considered this Table the first in chro-
nological order, although numbered the fifth ; for as the writ-
ing of the first five Tables was from right to left, so, he con-
ceived, the numbering ought to have been the same way.
Sir William also stated that as he intended to read transla-
tions of all the Tables in succession; he would wish to defer
the printing of those he had read on the 22nd of January,
until the previous Tables had been laid before the Aca-
demy.

These Tables Sir William considers asnarratives of Etrus-
co-Phoenician voyages ; and as the account of Hanno’s voyage
along the west coast of Africa, was placed up in the Temple
of Saturn at Carthage, so he conceives were these fixed up
in the temple at Eugubium, in accordance with the custom
of the Pheenician people. :

The voyage, of which this table is an account, was from
Etruria to Carne, in the island abounding in cattle, (Britain).
It commences with the departure of the expedition, and tells
us that proceeding to the Mouth of the Straits, they encoun-

201

tered an opposing current, which they overcame, and entered
the Port, (Cadiz), where they got a supply of good water.
They sailed again with favourable winds and currents for
some time, when they encountered a foul wind, and having
succeeded in making the land, they again obtained water, and
proceeded on to Carne, where they arrived safely.

The description of the country follows: showers fell fre-
quently, the wind was boisterous, and the sea rough. Nearly
west, about a day’s sail, was another island country which the
men saw on the voyage. The country they were in was
green, fertile, and fit for habitation. The frequent showers
created many brooks and rivers, which watered the country
well. They had plenty of food. They were surprised by an
extraordinarily great fall of the tide, which left the strand
dry ; but it was fortunate, as it enabled them to stop the
leaks of their ship which were bad.

The island is represented as the largest of islands; and
the success of the first attempt is represented as encouraging
to future voyagers, the safety of passing the ocean having
been demonstrated. They had deers’ milk to drink. The
country is described as hilly.

The superiority of their seamen and skill depends on being
well supplied with food; and much is said about the conse-
quences likely to follow the progress they had made in navi-
gation, and their knowledge of tides and currents.

On their return, when they got to the hot climate, they
were attacked with the scurvy, having had no rain for twelve
days ; but the wind was fair, and the sea favourable. They
arrived in safety at the Mouth, and entered the Port, (Cadiz),
where they stopped three days, and obtained a supply of
provisions and water. The ruddy appearance of the Mouth
(Gibraltar) is described, and the favourable current into
the Mediterranean, into which they sailed, and in three days
more arrived at their home in safety.

202

George Downes, Esq., M. A. read a paper entitled“ Some
Remarks on the Antiquitates Americane, lately published in
Copenhagen.”

The author, after remarking that this volume, which had
appeared under the auspices of the Royal Society of Northern
Antiquaries, contained an account of the early discoveries of
the Northmen in America, stated the two-fold nature of his
object :—

Ist. To advert to some leading features of the past re-
searches of the Society in connexion with those discoveries.

2nd. To hazard a conjecture respecting their future re-
searches.

The author observed, in the first place, that the present
account, although not altogether new, was not only more cor-
rect than any other, but supported by evidence, drawn partly
from Icelandic MSS. nearly coeval with the principal events
recorded, which took place about the opening of the eleventh
century, partly from the modern researches of learned Ame-
ricans. He stated that, as Arctic discoverers of America
the Northmen attained as high a latitude as the most distin-
’ guished modern navigators ; and detailed the Icelandic geo-
graphy of the eastern part of North America, from Cumber-
land Island to the Chesapeak. He next adverted to the Irish
part of the same continent, supposed to extend from the
Chesapeak to the Gulf of Mexico, and inwards to the Missis-
sippi. This tract was called Whitemensland, or Great Ire-
land, and was inhabited by an Irish colony prior even to the
Norse ante-Columbian discoverers of America. Evidence
of this fact was adduced from the Antiquitates Americane,
in the form of two traditions :—one held by the Shawanese
Indians who had emigrated from Florida to Ohio; the other
by the Faroese islanders. To this evidence the author ad-
ded a conjecture of his own, founded on the similarity be-
tween the first part of the word Esfotéland (a name of the
Icelandic Vineland, which does not occur in the work,) and
Scotia, an old name of Ireland.

203

After alluding to some passages respecting the mysterious
territory of Great Ireland, as given in the adventures of Thor-
finn Karlsefne, Gudleif Gudlaugson, and Ari Marson, the
author proceeded to animadvert on three inferences deduced
from the Antiquitates Americane, in a paper read at the last
meeting of the Academy.

1. Theexplanation of the surname of Ari Marson—* son
of the sea”—in the ordinary sense of a person of unknown
parentage, arrived by ship from some unknown land, was de-
nied to be tenable, as the genealogy of Marson is given in
both a textual and tabular form. The figurative meaning—
that of one addicted to nautical pursuits, or distinguished for
naval enterprise, was also impugned—as likely to be em-
ployed in the language of the Celts, who were averse from
navigation, but by no means in that of the Icelanders, who
were all sons of the sea, and among whom domiciliation on
board formed even a part of the Viking code of laws. The
author added, that the sculptor Thorwaldsen, and Professor
Finn Magnusen, were both descended from Ari Marson ; and
that the name of an Irish princess, called Ingebierg in Ice-
landic, Ingijbcerg in Farvish, but supposed to be Inivaca,
also appeared in the genealogy.

2. The author next disputed the identity of Brazil wood
with mazer, a wood of New England, the Vineland of the
Northmen, citing Dr. Bancroft’s description of the former.
He denied that Brazil-wood had ever been found in a lati-
tude so far north, and contended that intelligent savages
usually discover the dye-stuffs within their reach, but that
the Skrelings, or Esquimaux, who encountered Thorfinn
Karlsefne, bought red cloth from him with avidity, being
evidently attracted by the novelty and brilliancy of the co-
lour; that the Skrelings were an intelligent race appeared
evident from their possessing a kind of balista, and other
warlike engines unknown to the Northmen. To refute the
possible objection that Brazil wood, if a product of ancient

204

Vineland, might have been used as an ornamental timber,
various passages were translated from the Icelandic, which
were accompanied by the opinion of the editor of the Anti-
guitates Americane, from which it appeared that the mazer
was a kind of maple, a tree which still flourishes in New
England ; and this opinion was further supported by a line
from Spenser’s Fairy Queen, and by the etymological simi-
larity of the word mazer to the Latin acer.

3. In reference to an inscription on the Assonet Rock, in
Massachusetts, the author alluded to the improbability that
Thorfinn Karlsefne—the limit of whose discoveries is sup-
posed to be marked by the rock—would have omitted all men-
tion of his own name in recording them; and showed that
certain letters, on the supposed absence of which another
theory had been formed, were present in the most approved
copies of the inscription, three drawings of which were ex-
hibited to the Academy.

Mr. Downes in the second place, propounded his conjec-
ture respecting the future discoveries of the Northern Anti-
quaries in the field of American research. From the simi-
larity both in spelling and meaning of Haiti, “ highlands,”
(the restored name of St. Domingo, or Hispaniola,) to the Ice-
landic local designation Heiihi, as well as that of Bohio, “ the
house,” (another name of Haiti,) to the Icelandic bud, (the
English “ booth,”) also used as a local designation in that
language, he inferred that the Northmen may have visited
the island ; and he showed, from the northern languages, that
the final d, being mute, occasioned no difficulty. He sup-
ported his conjecture by adducing the authority of Doctor
Barton, cited by an American correspondent of the editor of
the Antiquitates Americanz, as to the existence of rocks simi-
lar to that of Asonet, in the confines of the rivers Lata and
Maragnon, in South America, on which, however, it would be
premature to lay much stress. The probability of a Norse
discovery of the West Indies he maintained from some par-

205

- ticulars, connected with the residence of Ari Marsonin Great
Ireland, which was not far from Haiti.

The author further alluded to the similarity of the Irish
boz, and the Hebrew 3 or in2, to Bohio, and hinted at the
possible Irish or Jewish discovery of the island, should the
former conjecture prove fallacious.

After recommending the Antiquétates Americane to the
Icelandic student, as a most eligible text-book, and a complete
contrast to the Antiquitates Celto-Scandice, the author con-
cluded by expressing his belief, that a closer connexion with
the antiquaries of Copenhagen, and a correspondence with
the learned of America, might lead to such results as would
shed additional lustre on the annals of the Academy.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de V Acade-
mie des Sciences. Par MM. les Secretaires Perpetuels,
Premier Semestre. Nos. 19, 20, 21. Tables Alphabétiques.
Juillet-—Decembre, 1837. Presented by the Academy.

Researches on Heat. Third Series. By James D. Forbes.
Esq. F.R.SS. L. & E., F.G.S. (From the Transactions of the
Royal Society of Edinburgh. Vol. 14.) Presented by the
Author.

The Origin of the Egyptian Language, proved by the
Analysis of that and the Hebrew, in an Introductory Essay.
By Dr. L. Lowe. Presented by the Author.

Journal of the Statistical Society of London. No. 11.
June, 1833, Presented by the Society.

206

June 25, 1838.
SIR Wm. R. HAMILTON, A.M., President, in the Chair.

Dr. Apjohn made some remarks upon the subject of the
Specific Heats of Gases.

The author stated that he had received, some months
since, a memoir on the subject of the specific heats of
gases, by M. Suerman, an eminent Dutch philosopher; upon
examining which, he was not a little surprised to find that the
method of the author was identically the same with that which
he had himself employed, in a paper on the same subject,
which has appeared in the last volume of the Transactions
of the Academy. The following passage of M. Suerman’s
preface, however, completely removed his apprehensions of
having been anticipated—“‘ Tandem opus aggressus, et oc-
cupatus in idonea paranda supellectili diarium accepi Angli-
cum, quo in collegio, quod Dublini habetur, Chemiz Profes-
soris Apjohn continebatur disquisitio, ex eodem illa principio
fluidorum elasticorum calorem specificum derivans. Pri-
mum,—quid sileam?—animo despondebam quum novitatis
colorem quz mihi precipue arridebat, de meo evanescere
viderem proposito.”

This passage, he stated, he had been long anxious to
bring before the Academy, lest, when Suerman’s Thesis came
to be noticed in the British journals, any Member of the
Academy should suppose that he had borrowed his method
from the learned Dutchman, and had done so without
acknowledgment.

Dr. Apjohn then proceeded to remark upon some points,
in reference to which he considered himself as having
been misapprehended by M. Suerman. Thus he is repre-
sented in the following passage, as adopting an erroneous
method of estimating the caloric of elasticity of aqueous
vapour. “ In computando vero formulam quam a claro Gay-

207

Lussac propositam vidimus, errorem effugere studuimus
quem miror, etiam a viris celeberrimis commissum esse.
Ponitur enim et in hac formula, et psychrometrica quam
Dr. Apjohn proposuit, J, sive caloricum vaporis latens, ter-
minus constans. At vero et theoria assumit, et experientia,
quatenus adhuc innotuit, docet, non esse caloris quantitatem
quam durante evaporatione vapor latens reddit, quacumque
temperatura constantem, sed quantitatem calorici, que deter-
minato vaporis pondere continetur, quod in maximo densita-
tis habetur.”

Dr. Apjohn could not admit the applicability of this
extract to himself, and in his vindication referred to the
following passage, which occurs in his first paper on the
Dew-point :—‘ It must of course be admitted, that the ca-
loric of elasticity of vapour varies with the temperature, and
that it is represented by 1129 only at the temperature of
50°, a point chosen by me as being nearly the mean tem-
perature of Dublin. In strictness, the number employed
should be 967 -+ 212 — ¢’, but it would be easy to show that
the uniform use of 1129 cannot give rise to any material
error.” The latter part of this passage, he observed, was
intended only to apply to the meteorological use of his for-
mula, and not at all to it when employed in the investigation
of the question of gaseous specific heat. And had M. Suer-
man repeated the calculation of his experiments he would
have found that he, Dr. A., had, while engaged with the
specific heats of the gases, invariably employed the rigorous
method of estimating the caloric of elasticity of vapour.

Dr. A. then drew attention to a tabular view of his
results compared to those of Suerman, from which it ap-
peared that there was a very close correspondence between
them, a correspondence noticed and admitted by Suerman
jn the following passage: ‘‘ siquidem ad diversissimum atten-
damus apparatum quo usus est, fatendum satis bene sibi con-
venire experimenta D™s- Apjohn, atque nostra. Utraque

208

vero multum distant ab experimentis doctorum Deloroche
atque Berard, ad que nostra propius accedunt ratione flui-
dorum elasticorum elementariorum, experimenta D. Apjohn
ratione aerum compositorum.” ‘The opinion, however, here
expressed cannot, Dr. A. conceived, be considered as well
sustained by the numbers adduced by Suerman. ‘Thus, to
give buta single example, the specific heat of hydrogen com-
pared to that of an equal volume of air, as deduced by
Suerman, was 1.3979, and as deduced, according to Suerman,
by Dr. Apjohn. was 1,8948. Here is a material difference,
quite beyond the probable errors of experiment, in expla-
nation of which Dr.’ Apjohn stated, that 1,8948, and the
other numbers attributed to him by Suerman, were, in
point of fact, not those which flowed from his experiments ;
and at the same time admitted, that when they were so con-
sidered by Suerman, he, Dr. A. himself, was in some degree
to blame. He had published his first results as the specific
heats of equal weights, when they were in reality the specific
heats of equal volumes; but in arriving at them it was neces-
sary to be subjected to a particular correction, which, howe-
ver, materially different in its influence upon them, according
as it is applied to the case of equal volumes or of equal
weights. Of these facts Suerman was not aware, and was
thus prevented from perceiving that the very close corres-
pondence which he recognized between the two series of
results amounted to an almost perfect identity.

This identity, however, Dr. A. stated to be true of them
when viewed relatively but not absolutely. The direct de-
terminations by Suerman of the specific heat of air and of
the different gases, were, Dr. A. alleged, in every instance
greater than those at which he had arrived. This he attri-
buted to three causes: Ist. To Suerman’s estimating the
ealoric of elasticity of vapour higher than Dr. Apjohn had
done. 2nd. To his employing the formula of Gay-Lussac,
which differed from that which Dr, Apjohn had employed in

209

containing as a divisor, not p, but p—f’. But, 3rd, _prin-
cipally to Suerman having in no one instance obtained in his
experiments depressions of such magnitude as those which he
himself had observed. Dr. Apjohn did not explain the cause
of this latter circumstance, as it would have required him to
describe the very elaborate but rather complicated appa-
ratus of M. Suerman, and to enter upon other details of a
critical nature, which he conceived unsuited to a general
meeting.

In conclusion, Dr. Apjohn stated, that M. Suerman had,
in one direction, prosecuted the research in question further
than he himself had done, having experimentally investi-
gated the specific heat of air ata series of pressures less
than that of the atmosphere. M. Poisson had given, in his
Traité de Mecanique, a formula for solving such problems,
derived from analytical considerations, which however was
found by Suerman to lead to numbers quite different from
those to which his experiments had conducted.

To the preceding abstract of his observations, Dr. Apjohn
is desirous of appending the following formule :—

fie _ 30
TS a l
48d p (I)
fh fein 30 ‘
al yee (2)

In each of these a is the specific heat of the gas compared
to that of an equal volume of atmospheric air, f’ the tension
of aqueous vapour of maximum elasticity, at the temperature
shown by a wet thermometer placed in a current of such
gas, and d the depression, or difference between the indica-
tions of the wet and a dry thermometer. Formula (1) is
that which Dr. Apjohn communicated to the Academy in
November, 1834, and which he employed in his researches
on specific heats. Formula (2) is that which has been used
by Suerman, and the investigation of which he attributes to
Gay-Lussac. The former formula had been previously ar-
U

210

rived at by Ivory, (a circumstance to which Dr. Apjohn
has alluded in his first paper on the Dew-point, without,
however, having been at the time aware that Ivory’s result and
his own were perfectly identical,) and the same is probably
true of Dr. August of Berlin, as may be collected from the
following passage of Dr. Suerman’s Thesis, p. 69 :—

“‘ Formulam psychrometricam ex theoria mixtionum aeris
ac vaporis, anno 1834 deduxerat D. Apjohn, iisdem innisus
principiis quibus Gay-Lussac de aere sicco, August et Ivory
de humido, problema solverant, non tamen hos auctores
secutus.”

The Rev. Cesar Otway read a paper “‘ on the Ruined
Abbeys in the Province of Connaught.”

His object was to shew, in the first instance, the differ-
ence between the ancient Irish monastic establishments, and
those subsequent to the Anglo-Norman conquest. He then
called the attention of the Academy to the rapid demolition
of these interesting religious structures by the people, who
make them places of common and much prized sepulture, and
(desiring to mark the places where their friends are buried)
recklessly tear down the quoins, corbells, capitals of pillars,
and all the elaborate ornaments they can lay their hands
on, in order to answer the purpose of head stones.

Mr. Otway suggested the possibility of appointing per-
sons who would act as conservators of these ancient edifices,
and expressed his hope that the clergy might be made instru-
mental in putting a stop to the dilapidations he complained
of. Mr. Otway alluded to the well known Fresco paintings
on the walls of the choir of the Abbey of Knockmoy; and.
having stated that a rapid decay is in progress, whereby
there is a likelihood of these interesting representations be-
ing speedily obliterated, he suggested that some artist (one
who combined the execution of a good draughtsman with
the taste and enterprize of an antiquarian) should be em-

241

ployed to copy them. Mr. Otway then alluded to the pro-
perty which one of the vaults at Knockmoy possesses of
preserving from corruption the bodies therein deposited,
and took occasion to animadvert on the careless and unbe-
coming way in which these depositories of the dead were
left open to public intrusion. Having spoken of Rossreilly
Abbey, near Headford, and exhibited a moss-covered skull
taken from these ruins, he next adverted to the Abbey of
Cong; there also he shewed that the prejudices and super-
stitions of the people are accelerating the demolition of the
building, and, as an instance, he stated how, not long ago,
the tomb alleged to be that of Roderick O’Connor, was
overwhelmed by a person who, in consequence of a dream,
undermined the Abbey-wall to come at hidden treasure.
Mr. Otway concluded his paper with an account of Clare
Island and Abbey, the residence and place of interment of
the famous Grace O’Mealy.

Sir William Betham read a paper on two remarkable
pieces of antiquity preserved at Cong, in the County of
Mayo.

The first, he stated, is a cross, whose perpendicular shaft
is six inches high, the arms one foot six inches, and the
whole five-eighths of an inch thick. Upon the edge is the
following inscription, intimating that this reliquary once
enclosed a portion of the true cross :

HAC. CRVCE. CRVX. TEGITVR. QVA. PASSVS. CONDITOR. ORBIS.

There are several other inscriptions in the Irish charac-
ters and language, of which Sir William also gave readings
and translations; but these he has since withdrawn.

The second reliquary described in this paper, was known
popularly, as the author stated, by the name of the Breast-
plate ; but in his opinion it was undoubtedly a case for a

manuscript copy of the Gospels. Sir William exhibited a
; u2

212

wax model of the front of this reliquary, with a drawing of
the cross, which he presented to the Museum of the Aca-
demy.

Mr. Petrie, by permission of the President, made some
remarks on Sir William Betham’s paper, in which he pointed
out the original uses of these ancient reliquaries, and de-
tailed at considerable length their history, gathered from the
inscriptions found upon them, (of-which he gave translations, )
and from the mention made of them in the Irish Annals and,
other records.

It was resolved, that Mr. Petrie be requested to prepare
a paper for the Transactions of the Academy on the history
of these reliquaries, in order that the valuable information
he had collected respecting them might be preserved, and
made more generally known.

Dr. Coulter exhibited a specimen of the Sphinx porcellus,
taken at Killiney, and stated that this rare insect had pro-
bably never before been found so far north in Ireland.

The reading of papers being concluded, the session was.
closed with the following

ADDRESS BY THE PRESIDENT.

The time has now arrived for terminating the present session ;
and it will, no doubt, be gratifying to you, as it is to me, that our
closing act should be the public presentation of a Medal to one of
our most distinguished Members; that Medal being the first which
has been awarded by your Council in the exercise of the new and
fuller power confided by you lately to them, and in execution of the
plan which was announced to you at the time when you gave them
that enlarged discretion, with respect to the bestowal of honorary
rewards.

That plan, as you may remember, differs little from the scheme
suggested by me in the inaugural address which I had the honor

213

to deliver on the occasion of first taking the chair of this Academy:
the only difference, indeed, so far as science is concerned, being
the subsequent adoption of a suggestion of Professor Lloyd, re-
pecting a change of distribution of those subjects which were in-
cluded by me under the two great heads of Physics and Physio-
logy, but by him under those of Experimental and Observational
Science, or Physics and Natural History. The time for acting
upon this modification has not, however, as yet arrived; and be-
fore the suffrages of your Council were collected, at its last meet-
ing, on the question of the absolute and relative merits of the
various communications which have lately been made to our Trans-
actions, it was resolved to postpone, till after the recess, the con-
sideration of all scientific or other awards, except only that which
should be made for the most important paper in pure or mixed
mathematics, communicated during the three years which ended
in March 1837, and already actually printed. The papers coming
within this definition were few; the authors of taem were only two,
Professor Mac Cullagh and myself. The decision, which in theory
is a decision of the President and Council, and which did in fact
receive my cordial and previously expressed concurence, was in
favour of Mr. Mac Cullagh’s paper ‘‘ On the Laws of Crystalline
Reflexion and Refraction,” contained in the just published part of
the eighteenth volume of the Transactions of this Academy.

It may happen that upon future occasions of this sort, if it shall
again become my duty to present from this Chair those Medals
which may hereafter be awarded, for papers of other triennial cycles,
and upon other subjects, I may not think it necessary or expedient
to occupy your time by any but the briefest statement of the
grounds on which those future awards may have been made. But
‘on the present occasion, which is (to me at least, and in relation
to our new plan) the first occasion of its kind; while the subject
is one of a class to which my own inquiries have been much di-
rected, and upon which, therefore, I may speak with a less risk of
impropriety than upon many others; and while we, as an Aca-
demy, by extra hours and extra nights of attendance, during that
busy session which is now about to close, have earned for ourselves
a little leisure, on this last night of meeting, without interfering (as

214

we hope) with the rights, or even with the convenience of authors ;
I think myself allowed to enter more at large into the merits of the
award, and to lay before you some of the thoughts which the pe-
rusal of the present prize essay has suggested to my own mind.

When ordinary light is reflected at the common boundary of
two transparent and uncrystallized media, as when we see (for ex-
ample) the reflexion of the sun in water, the reflected light differs
from the incident in both direction and intensity, according to laws
which were known to Euclid in so far as they regard direction,
but of which the discovery, in so far as intensity is concerned, was
reserved for the sagacity of Fresnel. In general, the laws which
regulate the changes of the direction of light have been found easier
of discovery than those which regulate its changes of intensity; the
laws of the reflexions and refractions of the lines along which light
is propagated, than the laws of the accompanying determinations or
alterations of its planes of polarisation ; or, to express the same dis-
tinction in the language of the theory of undulations, it has been
found easier to assign the form of the waves which spread from any
origin of disturbance through any given portion of the elastic lumi-
niferous ether, than to assign the directions and relative magnitudes
of the vibrations which constitute those waves, and the laws which
regulate the changes of such vibrations, in the passage from one
medium to another.

The laws which regulate such changes of vibration, produced
by reflexion and refraction, at the boundaries of crystallized
media, have been the special object of Mr. Mac Cullagh’s investi-
gations, in the paper now beforeus. But in investigating them, he
has been obliged to consider also the laws which regulate the vi-
brations of the ether, in the interior of a crystallized body, and
not at its swrface only ; the laws of the propagation as well as
those of the reflexion and refraction of light. His researches are
therefore connected intimately with a wide range of optical pheno-
mena; and the hypotheses on which his formule are founded, and
which seem to have their own correctness proved by the experi-
ments of many kinds with which they have been successfully com-
pared, though liable, of course, like every physical induction, to be
modified in some degree by future observation, appear to be en-

215

titled to assume henceforth a very high rank among the principles
of physical optics.

The method which Mr. Mac Cullagh has adopted may be said
to be in general the method of mathematical induction, as distin-
guished from dynamical deduction. He has not sought to deduce,
from any pre-supposed attractions or repulsions, and arrangements
of the molecules of the ether, any conclusions respecting the vibra-
tions in the interior or at the boundaries of a medium, as necessary
consequences of those dynamical principles or assumptions. But
he has sought to gather from phenomena a system of mathematical
laws by which those phenomena might be expressed and grouped
together, be conceived in connexion with each other, and receive
an inductive unity. He has sought to arrive at laws which might
bear somewhat the same relation to the optical observations already
made, as the laws of Kepler did to the astronomical observations of
his predecessor Tycho Brahe, without seeking yet to deduce these
laws, as Newton did the laws of Kepler, from any higher and
dynamic principle. And though, no doubt, it is to such deduction
that science must continually tend ; and though, in optics, some
progress has been actually made, by Cauchy and by others, toa
dynamical theory of light, as a system of vibrations regulated by
forces of attraction and repulsion ; yet it may well be judged a
matter of congratulation when minds are found endowed with
talents so high as those which Mr. Mac Cullagh possesses, and
willing to apply them to the preparatory but important task of dis-
covering, from the phenomena themselves, the mathematical laws
which connect and represent those phenomena, and are in a manner
intermediate between facts and principles, between appearances and
causes. ;

It was thus, that, in a former paper, Mr. MacCullagh proposed,
as mathematical expressions for the phenomena of Quartz, a system
of differential equations, which are indeed simple in themselves,
and seem to agree well with observation, but have not yet been
shewn to be consistent with dynamic views. And in that later
memoir for which the present prize is awarded, he has, in like
manner, adopted some hypotheses, and rejected others, without
apparently regarding whether and how far it may seem possible

216

at present to reconcile such adoption or such rejection with received
opinions respecting the mechanism of light ; exhibiting thus, a
kind of intellectual courage, in admiring which I am fortified by
the opinion of Sir John Herschel, who lately , in a conversation and
a letter, expressed himself thus to me: ‘‘ The perusal of Mr. Mae
Cullagh’s paper on the Laws of Reflexion and Polarisation in Crys-
tals, has, although cursory, produced a very strong impression on
my mind that the theory of light is on the eve of some considerable
improvement, and that by abandoning for a while the @ preorz or
deductive path, and searching among phenomena for laws simple
in their geometrical enunciation, and of more or less wide applica-
bility, without (for a while) much troubling ourselves how far
those laws may be in apparent accordance with any precon-
ceived notions, or even with what we are used to consider as
general principles in dynamics, it may be possible to unite scat-
tered fragments of knowledge into such groups and masses as
shall afford glimpses of their fitness to combine into a regular
edifice.”

The hypotheses which are the bases of Mr. Mac Cullagh’s
theory of Crystalline Reflexion and Refraction are the following.
He supposes that the form of the wave surface in a doubly-
refracting crystal is that which was assigned by Fresnel, and that
the vibrations are tangential to this surface, but that they are
perpendicular to the ray, and consequently parallel to the plane
of polarisation ; whereas Fresnel supposed them to coincide with
the projection of the ray upon the wave, and consequently to
be perpendicular to the plane of polarisation. Professor Mac
Cullagh supposes also, with Fresnel, that the vis viva is pre-
served, or in other words, that the reflected and refracted
lights are together equal to the incident; but in applying this
principle to investigate the refracted vibrations, he supposes, in
opposition to Fresnel, that the density of the ether is not changed
in passing from one body to another. And he supposes, finally,
that the vibrations in two contiguous transparent media are equi-
valent ; or, in other words, that the resultant of the incident and
reflected vibrations is the same, both in length and direction, as
the resultant of the refracted vibrations ; whereas Fresnel had

21%

supposed only that the vibrations parallel to the separating surface,
but not that the vibrations perpendicular to the same surface were
equivalent.

And here I may be permitted to state, what indeed cannot fail
to be remembered by many here, that when the British Association
for the Advancement of Science met in this city, about three years
ago, (in August, 1835), a communication was made by Mr. Mac
Cullagh to the Mathematical and Physical section, ‘‘on the Laws
of Reflexion and Refraction at the Surface of Crystals,” which
embodied nearly all the principles or hypotheses that I have now
recited, and of which an abstract was printed in the London and
Edinburgh Philosophical Magazine for October, 1835, having
indeed been published even earlier (in September, 1835) by
Mr. Hardy here. The only supposition, which was not either
formally stated or clearly indicated in this abstract, was that of
the preservation of the vis viva; instead of which principle of
Fresnel, Mr. Mac Cullagh was, at one time, inclined to employ a
relation between pressures, proposed by M. Cauchy. Since, there-
fore, the leading principles of the new theory of Reflexion and
Refraction were all made known by Mr. Mac Cullagh so early as
the August of 1835, were printed in Dublin in the September of
that year, and in London in the October following, it will not, per-
haps, be attributed solely to national partiality if we claim for him
the priority of discovery on this curious and important question,
notwithstanding that a very valuable and elaborate memoir on the
same subject, embodying the same results, was communicated, in
December, 1835, to the Academy of Sciences at Berlin, by M. Neu-
mann, and was published in 1837, before the publication (though
after the reading) of that essay of Mr. Mac Cullagh, to which the
present prize is awarded.

It is, however, an interesting circumstance, and one which is
adapted to increase our confidence in these new laws of light, that
they should have been independently and almost simultaneously
discovered in these and in foreign countries ; and it will not, I
trust, be supposed that I desire to depreciate M. Neumann’s admira-
ble essay, if having recalled some facts and dates which bear upon
the question of priority,-I proceed to point out a few of the features

218

of Mr. Mac Cullagh’s briefer paper, which have appeared to me to
deserve a peculiar and special attention. I mean the geometrical
elegance of the principal enunciations, and the philosophical cha-
racter of the interspersed remarks.

As a specimen of the former, I shall select the theorem of the
polar plane. When light in air is incident on a doubly-refracting
crystal, it may be polarised in such a plane, that one of the two.
refracted rays’ shall disappear ; and then the one refracted vibration
which corresponds to the one remaining refracted ray, must (by
the hypotheses or laws already mentioned) be the resultant of the
one incident and one reflected vibration ; and consequently these
three vibrations must be contained in one common plane, which
plane it is therefore an object of interest to assign a simple rule
for constructing. In fact, the refracted vibration is known, in
direction, from the laws of propagation of light in the crystal, and
the hypotheses already mentioned ; if, then, we know how to draw
through its direction the plane just now referred to, we should only
have to examine in what lines this plane intersected the incident
and reflected waves, in order to obtain the direction of the incident
and reflected vibrations, and afterwards (by the rules of statical
composition) the relative magnitudes of all the three vibrations, or
the relative intensities of the incident, reflected, and refracted lights,
Now Mr. Mac Cullagh shows, that the desired construction can be
deduced from the properties of the doubly refracting medium or
wave,.as follows: Let or, op represent in length and in direction
the velocity of the refracted ray, and the slowness of the re-
fracted wave; so that, by what has been before supposed, the
refracted vibration ov is perpendicular to the plane tor ; then,
if a plane be drawn through the vibration ov, parallel to the
line tp, this plane, which Mr. Mac Cullagh calls the polar plane
of the ray or, will be the plane desired; that is, it will contain the
incident and the reflected vibrations, if these be uniradial, or, in
other words, if they have such directions, or correspond to such
polarisations, as to. cause one of the two refracted rays in the crystal
to disappear.

Many elegant geometrical corollaries are drawn, in the Essay,
from this theorem of the polar plane ; but'I shall only mention one,

219

(which includes, as a particular case, the remarkable law for deter-
mining the angle of polarisation of light reflected at the surface of
an ordinary medium, discovered by Sir David Brewster,) namely,
that when the light reflected from the surface of a doubly refract-
ing crystal is completely polarised, or, in other words, when the
reflected vibration has a determined direction, independent of the
direction of the incident vibration, then the reflected ray is per-
pendicular to the intersection of the polar planes of the tivo dif-
Serent refracted rays.
In this and other applications of the theorem of the polar plane
to the case where the incident light is polarised so as to undergo a
double refraction, the obvious manner of proceeding is to decompose
its one biradial vibration into two uniradial vibrations, and to treat
these separately, by applying to each the construction above described.
Yet Mr. Mac Cullagh remarks, that it requires proof that the reflected
and refracted intensities, thus determined, will have their sum ex-
actly equal to the intensity of the incident light ; or, in other words,
that the law of the vis viva will hold good for the resultant vibra-
tions, though we know, by the construction, that it holds good for
each system of uniradial components taken separately. In fact, if the
two separate incident vibrations, which correspond to the two sepa-
rate refracted vibrations, be inclined at an acute angle to each other,
they will generate by their superposition (according to the law of
interference) a compound incident light, of which the intensity ex-
ceeds, by a determined amount, the sum of the two separate or
component intensities ; and it requires proof that the two separate
reflected vibrations will in like manner be inclined to each other at
that precise acuteness of angle which will allow the intensity of the
compound reflected light to exceed, by precisely the same deter-
mined amount, the sum of the two separate intensities, correspond-
ing to the two separate reflected vibrations : (or that the same sort
of equality of differences between incident and reflected resultants
and sums will take place, when the angles are obtuse and not acute ;)
the two refracted vibrations being not in general (in either case)
superposed upon each other. Professor Mac Cullagh has arrived
at an equation of condition, as necessary for the foregoing agree-
ment, which expresses a property of the laws of propagation de-

220

duced from the laws of reflexion and refraction, however singular
it may appear that the latter laws should give any information re-
specting the former ; and he states that he has found this equation
to express rigorously a property of Fresnel’s wave. His demon-
stration of this latter property having not yet been published, I
have been induced to investigate one for myself; and have thus
been conducted to a construction of the condition in question, so
simple that it may perhaps be mentioned here. Let r and w de-
note the planes vor and vor in the figure before referred to, which
may also be called the planes of ray-polarisation and of wave-
polarisation, for the ray oT, or for the corresponding wave; and
let p’, t’, Rn’, w’ be analogous to P, T, R, w, but referred to any other
ray or wave; then the following is the relation to be satisfied:

OT. OP’. cos RW = OT’. OP. cos R'W;

rw’ and r’w denoting here diedral angles. Under this form, it is
easily proved that Fresnel’s wave surface possesses rigorously the
property in question. Mr. Mac Cullagh’s equation has been other-
wise obtained by M. Neumann, namely, as a condition for the pos-
sibility of depressing the equation of the vs viva to the first from
the second degree.

On this and many other points of the investigation, Mr.
Mac Cullagh (as I have already said) has thrown out many inte-
resting and philosophical remarks; for instance, that the perfect
adaptation which thus appears to exist between the laws of the pro-
pagation and those of the reflexion and refraction of light, is a
strong indication that these two sets of laws are derived from some
One common source, in other and more intimate laws not yet dis-
covered ; and that it is allowed to hope that the next step in phy-
sical optics will lead us to those higher and more elementary
principles by which the laws of reflexion and propagation are linked
together as parts of the same system. His remarks on the probable
connexion between the theories of metallic and crystalline reflexion,
and on the hopefulness of ascending to a true theory of light by
the method of mathematical induction from phenomena, (exempli-
fied, as has been seen, in his own papers,) rather than by attempting
prematurely to make deductions from dynamical principles, are
also well worthy of attention, though my own habits of thought

991

Ae

lead me to feel an even stronger interest in dynamic and deductive
researches.

But I have suffered myself to speak at greater length than has
been usually occupied by others before, or is likely to be occupied
by me hereafter on other similar occasions, and certainly at greater
length than was required to justify the award of your Council.
The reasons which I pleaded at the commencement of this address
may, perhaps, serve partly as my excuse for having occupied your
time so long; and some additional indulgence may have been
thought due by those who remember that many years ago, both
here and elsewhere, in public and in private, I expressed strongly
my admiration of the talents of him to whom I have now the
gratifying office of presenting this first public mark of honour from
his scientific brethren and cotemporaries.

[The President then, delivering the Medal to Professor
Mac Cullagh, addressed him as follows :—]

Professor Mac Cullagh,

I present to you this medal, awarded to you by the President
and Council of the Royal Irish Academy. Accept it as a mark of
the interest and intellectual sympathy with which we regard your
researches ; of the pleasure with which we have received the com-
munications wherewith you have already favoured us; and of our
hope to be favoured with other communications hereafter. And
when your genius shall have filled a wider sphere of fame than
that which (though already recognized, and not here only) it has
yet come to occupy, let ¢his attest, that minds were found which
could appreciate and admire you early in this your native country.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de lAca-
demie des Sciences. Par MM. les Secretaires Perpetuels.
Premier Semestre. No. 22, 1838. Tables Alphabetiques,
Juillet, Decembre, 1837. Presented by the Academy.

Journal of the Franklin Institute of the State of Pensyl-
vania, and Mechanics’ Register. Edited by Thomas P, Jones,

222
M. D. New Series, Vol. XX. Presented by the Franklin In-
stitute.

Proceedings of the Numismatic Society, 1836-37. Pre-
sented by the Society.

A Philosophical and Statistical. History of the Inventions
and Customs of Ancient and Modern Nations, in the Manu-
facture and Use of Inebriating Liquors. By Samuel More-
wood, Esq. Presented by the Author.

Two Spear Heads. Presented by Sir William Betham.

A Model in Wax of the ancient Reliquary described in Sir
William Betham’s Paper as “ the Breastplate of Cong,” with
a Drawing of the Crozier. Presented by the same.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

- 1838—1839. No. 14.

November 12.

SIR Wm. R. HAMILTON, President, in the Chair.

Rey. Matthew Horgan; George Alexander Frazer, Esq. ;
Sir Joseph O'Halloran, K. C.B.; and Halliday Bruce,
Esq., were elected Members.

Miss Caroline Herschel was elected an Honorary Mem-
ber.

Sir W. Betham read a paper in answer to certain objec-
tions made to the statements in his former papers on Etruscan
Mirrors, and on the fifth Eugubian Table.

Professor Kane read a note on the Theory of the Ethers.

In a late number of the Annalen der Pharmacie, Professor
Liebig asserted that Dr. Kane should relinquish his claim to
the discovery of the Ethyl Theory, in favour of Berzelius, on
two grounds,—first, that Dr. Kane’s view was not originally
more definite than that of Dumas, and did not possess the
completeness in which it was brought forward by Berzelius ;
and second, that Dr. Kane had taken no part in the subse-
quent discussions about the theory, had on many occasions
shown indifference towards its establishment, and fluctuated
between the old and new views. In the notice submitted to
the Academy, Dr. Kane undertook to show the imcorrect-
ness of Professor Liebig’s observations.

x

224

The idea thrown out by Dumas, to which Liebig alludes,
was, that ether might be considered as a base, and the acid
ethers as salts of that base. This idea Dumas himself, on
further consideration, rejected, and assumed ether to be a
hydrate of olefiant gas, which he made the basic element in
the acid ethers, thus rejecting the form c4H;0 4 acid, and
taking Ho + (cH, + acid,) as the foundation of all his sub-
sequent researches. The sense in which Dumas considered
ether as a base, was the same as that in which chemists re-
gard the vegetable alcalies as bases,—that is, bodies which
neutralize acids and form salts,—without seeking more pro-
foundly into their constitution, or involving any hypothesis ;
whilst the essence of the views propounded by Dr. Kane and
Berzelius consisted in considering ether as the oxide of a pe-
culiar compound radical (Ethyl. Ethereum) cju;. resembling
the ammonium of the ammonia series,—an idea which Dumas
never thought of proposing at all, and indeed one which
the state of science, at the time of his researches on the
ethers, could scarcely permit him to conceive.

So far from the Ether Theory being less complete, as
promulgated by Dr. Kane, than when proposed by Berze-
lius, Dr. Kane asserted the reverse to be really the case,
for it was only after Liebig himself had modified Ber-
zelius’ views, that the continental theory became identi-
cal with that previously brought forward in Dublin,—Ber-
zelius having destroyed the unity of the theory by making
alcohol c.H3;-++- 0, which we now know to be a totally different
substance, and Liebig having shown that it should be con-
sidered, cyH;0 -+ Ho, which it had always been considered in
the theory proposed by Dr. Kane. Thus in the only point
in which the theories differed, the form of Berzelius was the
less complete of the two.

Dr. Kane has, since the promulgation of that theory, been
induced, from the results of researches in other departments,
to suspend his implicit belief in its sufficiency. Having ad-

225

vanced in the history of the ammoniacal combinations an im-
portant stage beyond the ammonium theory of Berzelius, it
becomes of great interest that the nature of the ethers should
be investigated with the aid of the lights furnished by this
novel analogical point of view. This Dr. Kane purposes to
do; and in the mean time, while he looks upon the Ethyl The-
ory as the most consonant to all facts at present known, and
while, consequently, he will use on ordinary occasions its lan-
guage and formule, he holds himself free of all implicit
belief in any theories, which might only serve to embarrass
him in his future investigations.

Dr. Kane grants fully to the continental chemists the
honour of having developed the detailed evidence for the
truth of the Ethyl Theory, so far as it has been proved, and
claims no share whatsoever in that meritorious work. But
he cannot abandon his claim to having been the first to sug-'
gest the theory; and he affirms that in the form in which he
brought it forward, it was not merely more complete than
that of Dumas, but even than that of Berzelius, and in fact
identical with that now held by Liebig, Berzelius, and most
of the continental and British chemists.

DONATIONS.

Transactions of the Royal Academy of Sciences of Cupen-
hagen, Vols. I to VII. Presented by the Society.

Mémoires de ? Academie Imperiale des Sciences de St.
Pétersbourg. 6me Serie. Sciences Mathematiques, Physiques et
Naturelles. 6 Tomes. Presented by the Academy.

Mémoires de Académie Impériale des Sciences de St. Pé-
tersbourg. 6me Serie. Sciences Politiques, Histoire, Philo-
logie. 3 Tomes. Presented by the Academy.

Mémoires présentés a l’ Académie Impériale des Sciences
de St. Pétersbourg par divers Savans, et lus dans ses Assem-
blées. 3 Tomes, et Ire et 2me Livraisons du Tome Quatriéme
Presented by the same.

x 2

226

Recueil des Actes de la Séance Publique de 1 Académie
Impériale des Sciences de St. Pétersburg, tenue le 29 Décem-
ére, 1837. Presented by the same.

Comptes Rendus Hebdomadaires des Seances de ? Acadé-
mie des Sciences. Par MM. les Secretaires Perpetuels. No.
23, 1838; premier Semestre. Nos. 1—16; second Semestre.
Presented by the Academy.

Memoires de la Société Geologique de France. Tome
Troisieme. Premiére Partie. Presented by the Society,

Bulletin de la Société Géologique de France. Tome IX.
Feuilles 6—19. Presented by the Society.

Mémoires de ia Société de Physique et d’ Histoire Natu-
relle de Genéve. Tome VIII. Ire partie. Presented by the
Society.

Abhandlungen der Koniglichen Akademie der Wassens-
chaften zu Berlin. Aus dem Jahre, 1836. Presented by the
Academy.

Bericht iiber die zur Bekanntmachung geeigneten Verhan-
lungen der Konigl. Preuss. Akademie der Wissenschaften zu
Berlin. Aus dem Jahre, 1837. Presented by the same.

Bericht iiber die zur Bekanntmachung geeigneten Ver-
handlungen der Konigl. Preuss. Akademie der Wissenschaf-
ten zu Berlin aus dem Jahre, 1838. Presented by the same.

Discurso Lido em 15 de Maio de 1838, na Sessdo Publica
da Academia Real das Sciencias de Lisboa. Por Joaquim
José da Costa de Macedo. Presented by the Chevalier de
Macedo.

Transactions of the American Philosophical Society.
Vol. VI. Part I. New Series. Presented by the Society.

Journal of the Franklin Institute of the State of Pensyl-
vania. New Series. Vol. XXIJ. Presented by the Franklin
Institute.

Archeologia; or Miscellaneous Tracts relating to Anti-
quity. Published by the Society of Antiquaries of London.
Vol. XXVII. Presented by the Society.

227

Proceedings of the Royal Society. No. 33. Presented by
the Society.

Proceedings of the Geological Society of London. Vol. Il.

‘ No. 56. Presented by the Society.

The Journal of the Royal Asiatic Society of Great Britain
and Ireland. No.9. Presented by the Society.

Catalogue of the Chinese Library of the Royal Asiatic
Society. Presented by the same.

Report of the Seventh Meeting of the British Association
for the Advancement of Science ; held at Liverpool, in Sep-
tember, 1837. Vol. VI. Presented by the Association.

Ordnance Maps of the County of Westmeath, in forty-two
Sheets, including the Title and Index. Presented by his Ex-
cellency the Lord Lieutenant.

Map of the County of Mayo, with Sections, Views, Levels,
Fleights of the Hills, and Mountains, &c. &c.- By William
Bald, F.R.S.E. &c. Civil Engineer. Presented by the Author.

Oversigt over det Kongelige Danske Videnskabernes
Selskabs Forhandlinger og dets Medlemmers Arbeider fra
31 Mai 1836, til 31 December, 1837. Af Etatsraad og
Professor H. C. Orsted. Presented by the Academy of Sci-
ences of Copenhagen.

Observations Ostéologiques sur @ done eil Costal des
Batraciens. Par. Ch. Morren. Presented by the Author.

The same Author presented also the following papers to
the Academy :—

Récherches Physiologiques sur les Hydrophytes de la Bel-
gique. Premier Mémoire: Histoire @un Genre Nouveau
de la Tribu des Confervies, nommé Aphanizomene.

Recherches sur le Mouvement et ? Anatomie du Stylidium
Graminifolium.

Les Siécles et les Légumes, ou quelques Mots sur I’ His-
toire des Jardins Potagers.

De la Spécialité des Cultures propres aux établissements

228

Horticoles de Liége, et de VInfluence de la division du Tra-
vail en Horticulture. : :

Horticulture et Philosophie.

Considérations sur le Mouvement de la Séve des Dicotylé-
dones, communiquées al Académie Royale de Bruselles.

Note sur le Developpement des Tubercles Didymes.

Notes sur la Catalepsie des Dracocephalum Austriacum et
Moldavicum.

Recherches sur la Catalepsie du Dracocephalum Virgi-
manum.

Observations sur ? Anatomie et la Physiologie de la Fleur
du Cereus Grandiftorus.

Observations Anatomiques sur la Congélation des Organes
des Vegetaua.

Notice sur la Circulation observée dans ? Ovule, la Fleur
et le Phoranthe du Figuier.

Note sur V Effet Pernicieux du Duvet du Platine.

Adrien Spiegel. Extrait d’une Histoire inédite de la Bo-
tanique Belge depuis les temps les plus reculés jusqwd nos
jours.

Essais sur 0 Hétérogénie Dominante dans lesquels on
examine V Influence quexerce la lumiére sur la Manifestation
et les developpements des étres organisées dont Vorigine a été
attribuée a cette predendue generation directe, spontanée ou
équivoque.

Développemens et Recherches de Mathematiques élémen-
taires. Par. I. N. Noel. Presented by the Author.

Documents and Records illustrating the History of Scot-
land, and the Transactions between the Crowns of Scotland
and England, preserved in the Treasury of her Majesty's Ex-
chequer. Vol. I. Presented by the Commissioners of the
Public Records of the Kingdom.

Clinical Lectures, delivered during the Sessions of 1834-5°
and 1836-7. By Robert J. Graves, M.D., M.R.LA. Pub-
lished in America. Presented by the Author.

229

Magnetic Observations made during the Voyages of
HI. M. Ships Adventure and Beagle, 1826-1836, discussed by
Major Sabine, R.A., F.R.S. Presented by Major Sabine.

-Flora Batava. By H.C. Van Hall. Nos. 114 and 115.
Presented by the Author.

November 30. (Stated Meeting.)

SIR Wa. R. HAMILTON, A. M., President, in the Chair.

The President read the following letter which had been
addressed to him by M. Neumann of Konigsberg, on some
points connected with the history of the Laws of Crystalline Re-
flexion.

Monsieur,

Le haut prix que j’attache a votre suffrage et a celui
de Villustre Academie, a laquelle vous présidez, et lhonorable
mention, que vous avez voulu faire de mon mémoire sur la théorie
de la lumiére dans la séance de cette Academie du 25 Juin, m’en-
gagent a vous addresser la lettre suivante. Vous avez donné dans
cette séance un jugement dans la question de priorité, qui pouvait
s éléver entre Mr. Mac Cullagh et moi par rapport a la découverte
des lois suivant lesquelles la lumiere est reflechie et refractée par
des milieux crystallins ;—j’ai lhonneur de vous communiquer dans
ce qui suit quelques faits et quelques reflexions fondées sur ces
faits, et qui auraient été peut-étre de quelque influence sur ce juge-
ment. ,

Au commencement de l’année 1833 j’ai communiqué a Mr.
Seebeck de Berlin non seulement l’ensemble des principes de ma
théorie tels qu’ils se trouvent imprimés dans le § 2. de mon mé-
moire, mais j’avais illustré encore ces principes par leur application
aux milieux non crystallins. En méme tems j’ai annonce a Mr.
Seebeck, que les résultats tirés de ces principes par rapport aux

230

milieux crystallins étaient parfaitement d’accord avec ses observa-
tions sur l’angle de polarisation du kalkspath, et je lui fis part de
la formule méme, qui exprime l’inclinaison du plan de polarisation
du rayon polarisé par réflexion vers le plan de reflexion. Sous la
date du 11 Mai, 1833, Mr. Seebeck m’écrivit, que cette formule
aussi s’accordait parfaitement avec ses observations, qu’ il n’avait
pas encore publiées et qu’il avait la complaisance de me communi-
quer en manuscrit. Dans le printems de 1834 le manuscrit de
mon mémoire tel qu'il a paru depuis allait étre achevé; mais un
voyage que je fis dans ce tems et qui m éloigna assez long-tems de
Konigsberg, m’empécha de la publier incessamment. Cependant
javais pris soin d’en faire un abrégé dans lequel je dévéloppai com-
plétement les principes de ma théorie et les résultats auxquels elle
m’avait conduit par rapport aux crystaux 4 un axe.

J’envoyai cet extrait en Mai ou Juin, 1834, par la librairie de
Mr. Schropp de Berlin a Mr. Arago, en le priant de le faire impri-
mer dans les Annales de Chimie et de Physique, ce savant ayant dans
une note publiée dans ce tems marqué un grand intérét pour l’in-
vestigation des lois des intensités du rayon ordinaire et extraordi-
naire, lois qui se trouvaient parmi les résultats mentionnés. Il n’y
a pas de doute, que cet extrait ne soit parvenu dans les mains de
Mr. Arago, entre lesquelles il doit se trouver encore a présent. Du
reste, Mr. Jacobi en avait pris une connaissance detaillée, et 4 Ber-
lin il a été entre les mains de MM. Weiss et Poggendorf.

En passant par Vienne dans l’été de 1834, j’ayais. le plaisir
d’entretenir de mes resultats et de ma méthode Mr. Ettinghausen,
savant trés distingué et trés versé dans les parties les plus épineu-
ses de l’optique. Antérieurement j’avais enseigné mes doctrines
a Mr. Senff maintenant professeur a l’ Université de Dorpat, pendant
le séjour que fit 4 Koenigsberg ce jeune et habile physicien, qui
vient de publier un excellent travail sur les propriétés optiques et
crystallographiques du fer sulfaté.

Il suit de tout ce qui précéde, que déja en 1834, mes resultats
trouvés par rapport aux lois de reflexion et de refraction des erys-
taux n’étaient guéres inconnus aux physiciens de l’ Allemagne, qui
s’occupent de l’optique, et si déslors ils n’ont pas recu une plus
grande publicité, vous voyez, Monsieur, cela tenait aux Annales de
Chimie. La publication de mon mémoire a été rétardée par l'espoir

231

que j'avais concue de pouvoir lui ajouter une partie expérimentelle.
Mais l’exécution des appareils me faisant attendre trop long tems,
jal présenté vers la fin de 1835 a l’Academie de Berlin mon ouvrage
tel qu’ila été imprimé depuis parmi les mémoires de cette Aca-
demie. La partie expérimentelle a été publiée en 1837 dans le vo-
lume42 des Annales de Mr. Poggendorf.

Je vois du discours que vous avez tenu, Monsieur, dans la Sé-
ance de votre Academie du 25 Juin passé, et qui vient de m’étre
communiqué, que c’est déja en Aout, 1835, que Mr, Mac Cullagh a
fait 4 l’Association Britannique une communication sur les lois de
reflexion et refraction par les crystaux, et quia été imprimée dans
le Lond. et Edinb. Phil. Mag., Février 1836, Je crois trés volon-
tiers, que Mr, Mac Cullagh est parvenu aux resultats qui se trouvent
dans cette publication, par ses propres efforts et sans avoir eu con-
nuisance de mes travaux sur ce méme sujet. Toutefois ce ne sont
pas ces resultats qui pourraient étre objet d’une question de prio-
rité. Eneffet dans une note publiée dans les Annales de Mr. Pog-
gendorff, (vol. xxxviii. 1836,) Mr. Seebeck a montré queles formules
auxquelles est parvenu Mr. Mac Cullagh ne sont pas justes, et
qu’elles ne representent pas les lois de reflexion et de refraction par
les crystaux. Dans laméme note Mr. Seebeck a exposé, comment
les lois de reflexion et de refraction des milieux non crystallins con-
formes a cette definition du plan de polarisation, 4 laquelle on est
conduit dans la théorie de la double refraction, peuvent étre dédui-
tes des suppositions faites par Fresnel, avec la seule modification
de Vhomogéneité de l’éthér dans tous les milieux. Mais les sup-
positions de Fresnel ainsi modifiées forment la base principale de
ma méthode, dont j’avais déja fait part 4 Mr. Seebeck depuis plu-
sieurs années. I] est vrai, que dans les deux milieux Fresnel ne
suppose que l’égalité de deux composantes paralléles au plan de
séparation, mais l’égalité de la troisiéme n’ est qu'une simple con-
séquence de celle des deux autres et des autres suppositions. Ce
sont les suppositions de Fresnel modifiées de la dite maniére, qu’a
adoptées Mr. Mac Cullagh, aprés s’étre convaineu par la note de
Mr. Seebeck de la faussete des resultats qu’il avait jusque-la obtenus,
conviction quil’engaga a rejeter tout ce qui n’était pas conforme
4 ces suppositions, et des-lors seulement en 1837, dans le Lond. et
Edinb. Phil. Mag., Mr. Mac Cullagh est. parvenu aux mémes lois de

232

reflexion et de refraction que j’avais eues l’honneur de présenter a
lV’ Academie des Sciences de Berlin en 1835.

Vous voyez par tout ceci, Monsieur, que dés 1833 j’ai été en
pleine possession de la methode, et que dés le commencement de
1834 j’ai été en pleine possession des résultats qu’elle fournit, que
dans ce méme tems j’ai envoyé un abrégé contenant ces resultats et
luen manuscrit par plusieurs savans bien connus 4 Mr. le redac-
teur des Annales de Physique et Chimie pour le publier dans ce
recueil, et qu’d la fin de 1835, j’ai présenté l’ouvrage complet 4
present imprimé 4 l’Academie de Berlin;—vous voyez en méme
tems, que Mr. Mac Cullagh ayant communiqué 4 l’Association Bri-
tanique en 1835 des lois de réflexion et de refractiou crystallin, ces
lois ont été demontrées étre fautives par Mr. Seebeck in 1836, et
que Mr. Mac Cullagh n’est parvenu en 1837 aux vraies lois qu’
aprés avoir pris connaissance du fondement de ma méthode, et s’en
étre servi.

De tout cela resulte, Monsieur, que la priorité de la découverte
des lois de réfiéxion et réfraction par des crystaux n’est pas dou-
teuse, et qu'il n’y a pas de simultaneité entre mes travaux et ceux
de Mr. Mac Cullagh, dont du reste personne ne peut estimer plus
que moi le talent distingué.

Daignez, Monsieur, agréer les assurances de la plus haute con-

~ sideration avec laquelle je suis, &c.

F, E. NEUMANN.
Kéonigsberg, 5 Octobre, 1838.

When this letter was read, Professor Mac Cullagh re-
quested permission to make a few remarks. After express-
ing much regret, that his researches in the theory of light
shouldhave clashed with those of any other person, (though
in the present state of science such collisions were perhaps
inevitable,) he proceeded to say, that he did not think it ne-_
cessary to detain the Academy with a formal reply to the
communication which had just been read; it would be
sufficient for him to observe, in general, that the facts brought
forward by the writer, with reference to the history of his
own investigations, were all, without exception, of a private |

233

nature, not one of them being taken from any published do-
cument; that the first document of the kind, which pro-
fessed to give any account of M. Neumann’s “ method,” or
any statement of the principles employed in it, appeared in
the Annals of Poggendorf, (vol. xl. p. 497,) some months
after Mr. Mac Cullagh had published his ast paper on the
subject in the Philosophical Magazine, (vol. x. p. 43,) and
even after that paper had been noticed in the aforesaid
Annals, (vol. xl. p. 462); that M. Neumann’s Memoir in the
Berlin Transactions was not published until a later period ;
that, therefore, there could be no question about priority of
publication; and that, consequently, if it were to be ima-
gined, for a moment, that either author had borrowed from the
other, the presumption must necessarily be against M. Neu-
mann. With respect to M. Seebeck’s note, it would be enough
to state, that M. Neumann is not mentioned there at all;
that the principles there given by M. Seebeck are not ade-
quate to the general solution of the problem; and that
such of them as differ from those of Fresnel, had been
previously published by Mr. Mac Cullagh. It was clear,
therefore, that Mr. Mac Cullagh owed nothing on the score
of theory to any one but Fresnel. He had, indeed, made one
alteration in his theory as it originally stood; for he had
at first rejected Fresnel’s law of the vis viva, and had been
obliged to restore it afterwards, in order to account for cer-
tain experiments of M. Seebeck, which M.: Seebeck himself,
from want of sufficient principles, had not attempted to ac-
count for; but the real service which M. Seebeck had rendered
him, and for which he had frequently acknowledged his ob-
ligations, was the communication of these experiments, and
not any suggestion of the law of vis viva, which he knew
well enough before. In all this, however, it was plain that
M. Neumann had no concern, unless he chose to say, that
he had appropriated to himself Fresnel’s law of the vis viva,
that he had determined to regard it as the foundation of his

method, (le fondement de sa méthode,) and that thenceforward
no one else (however ignorant of such appropriation) could
have any right to use it.

Having thus endeavoured to prove his claim to priority
of publication, and to establish the independence of his own
researches, which was all that was necessary for self defence,
Mr. Mac Cullagh concluded by saying, that he would there
drop the argument, without discussing his claim to priority in
the abstract, as he had an objection to disputes of such a
kind, and did not wish to pursue them any farther than he
was compelled to do. But if any one thought it worth while
to examine the merits of this second question, he would
find the circumstances relating to it very fully and clearly
stated in the last number of the Proceedings of the Academy,
(page 217 of the present volume,) and would thence be
enabled to form a judgment for himself.

Mr. Downes read an Extract of a Letter from Pro-
fessor Rafn, of Copenhagen, containing the following que-
ries, addressed to the Academy, for the purpose of pro-
curing information available for the Historical Monuments of
Greenland, a work projected by the Society of Northern
Antiquaries :

“]. Arethere any accounts that the District of Majo
[Mayo] in Ireland, or its north-western section, was at the
close of the fourteenth century independent, or had separate
princes?

2, £* Where did these princes reside?

3. ‘We should like to have a catalogue of the princes
of this district from the earliest times.

4, “What harbours are there between Broad Haven
and the hay of Killala?

5. “What is the right name of the north point of the
district Majo? (Cape Binir or Cape Calliugh ?)

6. ‘Is this headland high, and visible from a great dis-
tance ?

235

7. “ Are there dangerous shallows off this Cape, and are
they near the shore, or at some distance?

8. ‘ The same questions are proposed in reference to the
cape, or headland Downpatrick [county Mayo] ?”

In addition. to these queries, written originally in English,
Mr. Downes communicated the substance of a passage in the
Danish part of the letter, of which the following isa transla-
tion :

“‘ Professor Magnusen, and many other distinguished Ice-
landers, are descended from various Irish and Scotch prin-
ces and kings, as will be fully elucidated in the British
and Irish Antiquities ; but a detailed account of the geneé-
alogies requires much and minute preparatory research.
We must try to excite increased interest, otherwise our
great work will never be published: it would extend to
four such volumes as the American Antiquities. Is there
any prospect of an adequate subscription towards the com-
pletion of the work, or must it be given up altogether 2?”

Mr. Downes suggested to the Academy the prcpriety
of contributing liberally to the furtherance of the two above-
mentioned works projected by the Society of Northern
Antiquaries, as likely to be highly interesting to the Academy
and to Ireland in general.

Dr. Barker exhibited to the meeting the production of
carbonic acid in the solid state, as effected by compres-
sion and refrigeration, according to the method discovered
by Thillorier, and with the simplified apparatus of Mr.
Addams.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de l’ Aca-
demie des Sciences. Par MM. les Secretaires Perpetuels.
Second Semestre. Nos. 17, 18. Presented by the Academy.

235

Memoires Couronnes par l Academie Royale des Sciences
et Belles-lettres de Bruxelles.. Tome 12 and 13. Presented
by the Academy.

Bulletin de l Academie Royale des Sciences et Belles-
lettres de Bruxelles. Années 1836 et 1837. Année 1838,
(Nos. 1—8.) Presented by the Academy.

Annuaire de ’ Academie Royale des Sciences et Belles-
lettres de Bruxelles. Troisiéme et Quatrieme Année. Par
A. Quetelet. Presented by the Author.

Annuaire de l Observatoire de Bruxelles, pour ? An. 1838.
Par le Directeur, A. Quetelet. Presented by the Author.

* Sur la Latitude de V Observatoire de Bruxelles. Par A.
Quetelet. Presented by the same.

De 0 Influence des Saisons sur la Mortalité aux différens
Ages, dans Belgique. Par A. Quetelet. Presented by the
Author.

Rapport sur les Observations des Marées, faites en 1835,
en differens Points des Cétes de Belgique. Par Messieurs
Belsaire et Quetelet, Rapporteurs. Presented by the same.

Proceedings of the Royal Society. No. 27. Presented by
the Society.

The American Almanac and Repository of Useful Know-
ledge. For the Year 1839. Presented by the American
Philosophical Society.

Remarks on the Classification of the different Branches
of human Knowledge. By J. W. Lubbock, Esq., F.R.S,
&c. Presented by the Author.

The India Review, and Journal of Foreign Science and
the Arts. Vol. I. Edited by Frederick Corbyn, Esq. Pre-
sented by the Editor.

Reduction of the Observations made by Bradley, at Kew,
and Wanstead, to determine the quantities of Aberration
and Nutation. By Dr. Busch, Assistant Astronomer at
the Royal Observatory of Kénigsberg. Presented by the
Author.

237

December 10.
SIR Wm. R. HAMILTON, A. M., President, in the Chair.

John Herbert Orpen Esq. was elected a member.

Professor Mac Cullagh presented two papyri, the gift of
George James Knox, Esq. by whom they were lately brought
from Upper Egypt.

Resotvep,—That the Council be directed to take the
proper steps to unrol and preserve the papyri.

Mr. Ball read a paper entitled ‘‘ Description of the Cy-
dippe pomiformis, Patterson, (Berde Ovatus, Flem.,) with no-
tice of an apparently undescribed Species of Bolina, also
found on the Coast of Ireland.” By Robert Patterson, Esq.,
Member of the Natural History Society of Belfast.

The ‘author referred to a paper of his published in the
Edinburgh New Philosophical Journal for January 1836,
giving some account of a tentaculated Beroe, taken in abund-
ance by him at Larne Lough, County of Antrim, inthe Spring
of 1835. He then noticed the occurrence, on different occa-
sions in 1836-7, of a BerGe, exhibiting a peculiar ramiform
arrangement of whitish internal vessels, branching off from
near the lower part of the stomach to the several bands of
cilia ; and detailed the observations by which he was enabled
to identify this with the Berde described in Mem. Wer.
Soc., vol. iii. p. 400, by Fleming,—the tentacula having es-
caped the notice of that writer, from the specimen he ex-
amined having been in an exhausted state when these
organs were retracted within the body. The presence of
the tentacula removes the animal from the Genus Berée of
Fleming, to the Pleurobrachia of the same author (Cydippe’
Eschs,) and as the specific name Ovata, under which it was
described in the Hist. of Brit. Animals, has been applied to

a different species, Mr. Patterson proposed that it should be
designated as the Cydippe pomiformis.

The disappearance of the internal ramiform vessels was
next noticed, and the steps by which the writer was enabled
to ascertain that the species now brought forward was iden-
tical with that described by him in 1835; and consequently,
that a BerGe, of the occurrence of which we have no record,
except of one individual taken in 1820, was abundant on
the Irish coast. Particular reference was made to Doctor
Grant’s paper (Zool. Trans. vol. i. p. 9,) on B. Pilens, with
a view to indicate the several points of agreement and of
difference between these, the only two British species of
tentaculated Beroes. The structure of the Cilia, the aqueous
currents at their base, the position and structure of the tenta-
cula, the food of the Berée, its vitality, consistency, want of
phosphorescence, movements, iridescence, times of appear-
ance, and diffusion round» the coast, formed the principal
topics embraced in the remainder of the paper.

The occurrence of the Bolina on different parts of the
Irish coast was mentioned, principally for the purpose of
enabling Mr. Patterson to refer to some points of its economy
for comparison and contrast with the C. pomiformis. He
reserved a detailed account of various particulars concern-
ing it to a future opportunity, when he expected to be able
to exhibit additional figures taken from living specimens,
and more accurately delineated than those at present brought
forward. Meantime, as the animal differed from the two
species of Bolina described by Mutius, he proposed to name
it provisionally Bolina Hibernica.

The President read a paper by the Rev. Dr. Robinson
“on the Longitude of the Armagh Observatory, given by
Chronometers and other Methods.”

After remarking the inconveniences, or uncertainties,
which to a certain extent attend the methods of determining

239

differences of longitudes by signals, geodetic measures, oc-
cultations, and transits, the author passes to the most direct
and natural method, by transport of chronometers. He
says, ‘the determination by chronometers depends on the
perfection of these machines, and in particular on their rate
being unchanged by the agitation of a long journey. This,
strictly speaking, is never the case, though it is sometimes
very nearly accomplished, and its effect will disappear from
the mean of the results obtained in going and returning,
if the circumstances of the two journeys are nearly similar.
Unfortunately it rarely happens, that an astronomer has
the power of making these experiments on a sufficient
scale: but such an opportunity seemed to Sir William
Hamilton, and myself, to present itself in consequence of
Mr. Dent’s chronometric visit to Paris, and the yet more re-
markable notice, read at the Newcastle Meeting of the
British Association, of the chronometric longitude of Sir
Thomas Brisbane’s Observatory. Mr. Dent not merely pro-
mised us every assistance, but when, having obtained the
consent of the authorities of our respective observatories,
we proceeded to make the necessary pecuniary arrange-
ments, he treated the matter as one of science, not of com-
merce, and not only took on himself the expense and risk of
the journey, but came in person.”

Dr. Robinson proceeds to mention the particulars of the
journey, and of the comparisons which were made with the
fifteen chrorometers which Mr. Dent brought with him.
Their rates and errors, as compared with Greenwich time,
had been determined, before starting, for the epoch of the
20th of September, 1838; they were compared with Dublin
time, in the observatory of Trinity College, on the 22nd of
that month, and with Armagh time on the 23rd and 24th; were
again examined in Dublin, on the 25th, and in Greenwich,

on the 27th of September.
Y

240

The fundamental formule employed by Dr. Robinson
are the following :
LIOE—W-+RI;
LIE’ —w —RI;
L being the difference of longitudes between an eastern and
a western station; E the correction of a watch when leaving
the eastern, and w the correction when arriving at the western,
while w’ and E’ are the corrections when leaving the latter
and returning to the former respectively ; 1, 1, the intervals
of time expended in thus going and returning; and R, PR’,
the losing rates corresponding. By supposing r’=r, he
obtains what he considers the true travelling rate, namely,
ice (e'—w')-(&—w)
uy I+r z
and the resulting longitude
Lot fp —w+eE—wr(i-r)?.
The errors are then examined to which these determinations
are liable, and the numerical elements are given, from which
are deduced fifteen values for the longitude of Armagh,
varying between the extremes 26™ 34°, 67, and 26™ 365, 32,
and giving as their general mean, 26™ 35%, 44, with a pro-
bable error less than 0%, 1.

Kclipses and occultations had given 26" 35°, 47; lunar
transits, 26" 358, 64; and a few comparisons, made under
unfavourable circumstances with a single pocket watch, con-
structed by the late Mr. Sharp, had appeared to give 26™
358,09. On the whole, Dr. Robinson is not inclined to
change the quantity which he gave some years ago to Mr.
Stratford, for insertion in the Nautical Almanac, namely,

+ 26™ 35%, 50.
as the west longitude of Armagh from Greenwich.

The same chronometric comparisons appear to require
that the value of the longitude of the Dublin Observatory,

241

as last determined by Dr. Brinkley, namely + 25™ 22, 0,
should be diminished by about a second.

The Rev. Dr. Drummond read “ An Essay on the Struc-
ture of English Verse, by the Rey. William Bruce, D. D.”

This Essay enters into a critical examination of the con-
stituent parts of English verse, commencing with its simplest
elements, and following them up through their various com-
binations. As the melody of a language must depend on
the classes of letters in which it most abounds, the poet
should introduce as many vowels and liquids as possible ;
availing himself of those sounds which are most agreeable
to the ear, and avoiding those which are guttural and harsh,
unless when the latter may be more expressive in making
the sound an echo to the sense. A propensity to imitative
sounds appears through the whole of our language, and, in
general, English has an advantage over the ancient lan-
guages, so far, at least, as expression depends on the ter-
mination of words.

The next element of verse is the syllable ; and this must
be considered as to quantity and quality. According to quan-
tity, syllables are long or short; as to quality, smooth or rough.
Accent affects particular syllables or letters, and the quan-
tity or length depends on the manner of pronouncing the
vowel, and on the number of consonants following it; for
every consonant that is sounded must require some addi-
tional time. Whether the structure of English verse de-
pends on quantity or accent, has long been a subject of
controversy, and able critics are found on each side of the
question. Sheridan affirms, that we have a peculiar advan-
tage in having two sets of feet, the one depending on quan-
tity, the other on accent. After all, it is little more than a
dispute about words ; accent alone will constitute verse, and
there can be no verse without it; in fact its power is such,
that we can hardly deny it to be the governing principle of

¥2

242

English versification. Our accent is different from that of the
Greeks and Romans: ours lays more séress on vowels or syl-
lables, theirs consisted in a depression or elevation of the
voice ; ours produces the effect of quantity, theirs was entirely
distinct from such an effect.

Another stress of the voice, which has great influence on
verse is, EMPHASIS, 7. e. stress with expression. As accent
is the ligament of a word, emphasis is the ligament of a sen-
tence. It combines and points out the words which ex-
press a sentiment; and is produced by a change of tone
adapted to the emotion which the sentiment inspires, not
always elevated, but often (perhaps generally) low. The
quantity of a syllable will often depend on emphasis; and
hence it follows, that every composer of modulated prose or
of verse, should be a good reader, or at least a good judge
of reading, for if he read with one idea of accent and em-
phasis, and his lines are afterwards recited with a different
one, it is plain that the metre will be spoiled.

An essential constituent part of verse is the roor. Our
verse consists of feet, and not merely of.a determinate num-
ber of syllables. The zambus is the foundation of English
heroic verse, but other feet are admissible in particular
places; and though the heroic line is said to consist of ten
syllables, it often comprises many more. This foot was also
the essence of the verse of the ancient tragedy and comedy,
being best adapted to dialogue according to Horace,—alter-
nis aptum sermonibus. It would seem, therefore, that the
ancient drama is peculiarly fit for exact translation into
English.

The excellence of verse consists, like that of beauty, in
uniformity and variety. It supposes a regular order and re-
currence of sounds; but if these be too uniform, it becomes
tiresome,—if continually broken, the metre is confused.

The pause is to be regarded as indispensable to ‘the
structure of verse, particularly the czsural and the final

243

pause,—the former in the middle, the latter at the close of
the line. The former does not always divide the line into
two equal parts, but may be varied according to the taste of
the writer; and in one line may be several pauses, though
one is generally stronger than the rest.

In Latin, the cesural pause is after the second foot; but
in English, the taste of the poet is shown in changing its
place. Expression often requires a deviation from rule, but
care must be taken that the pause shall coincide with tlie
sense, or even help,—certainly not mar it.

The difference between prose, verse, and poetry, is ex-
amined and explained at some length. They all consist of
Jong and short, accented or unaccented syllables. Dionysius
of Halicarnassus, and in our own day, Bishop W. Cleaver,
could find a certain order of feet in Demosthenes and Iso-
crates. The rythm of proseis unfettered, that of verse con-
fined within a certain number of feet. To this, poetry adds
poetical diction and figures. Verse, in the opinion of the
author, is essential to poetry. There may be verse without
poetry, but no poetry without verse; and according to this
decision, neither Fenelon’s Telemachus, nor Macpherson’s:
Ossian is to be considered as genuine poetry. In this,
every thing should be animated and impassioned; not a
single prosaic expression should be admitted into short:
poems; and if in long epic and didactic poems some indul-
gence to such expressions be allowed, it should be compen--
sated by the greatest attention to melodious versification..
With respect to the propriety of introducing the Alexan-
drine into heroic verse, there is a difference of opinion.
Johnson condemns the practice, as violating the prineiple of
verse ; but Dryden, who understood the subject better, says,
i Spencer gave me the boldness to use the Alexandrine. It
adds a certain majesty to the verse, and stops the sense from
overflowing into another line. I have frequently used the
triplet rhymes, because they bound the sense, and therefore

244

I make the last verse of the triplet a Pindaric, (that is an
Alexandrine,’ for besides the majesty it gives, it confines the
sense within the barrier of three lines, which would languish
if lengthened into four.”

After quoting the opinion of Dr. Johnson, of Dryden,
and of a writer in Number XIV. of the Classical Journal,
respecting blank verse, the author gives his own, and com-
mences by stating it as necessary to the perfection of any art,
that it should be difficult, yaXera ra xaXa, and that the great-
er the difficulty, within certain bounds, the more excellent
will be the execution. The facility of writing blank verse
presents such a temptation to run out into long declamatory
sentences, that it seldom gratifies the ear, except in some
select passages, where the poet is inspired by the beauty of
the subject. In rhyme the style is neater and more con-
densed ; the figures and images are more approximated, and
the impression more lively and vigorous. Variety in blank
verse is often, perhaps generally, indulged even to extrava+
gance, while uniformity is the reproach of rhyme.

The author maintains that the heroic hexameter of the
ancients is incompatible with our language; and concludes
with a variety of miscellaneous observations. An appendix
is subjoined, containing notes and examples illustrative of
facts and opinions occurring in the Essay.

The Secretary read the original Resolution of the Aca-
demy, by which the President of the Royal Society is an
Honorary Member, and likewise, the resolution of Council
of the 3rd of December, relating thereto.

It was ordered that the Diploma now read be engrossed
on vellum, and transmitted to the Marquess of Northampton,
President of the Royal Society.

The Academy then adjourned to the 14th January.

245

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de l Acade-
mie des Sciences. Par MM. les Secretaires Perpetuels.
Second Semestre. No. 19, 20. Presented by the Academy.

Statement of the Receipts and Payments of the Royal
Society, between Nov. 29th, 1837, and Nov. 29th, 1838. Pre-
sented by the Society.

Two Papyri, brought from Thebes in Upper Egypt, by
George James Knox, Esq. Presented by Mr. Knox.

January 14, 1839.
SIR Wm. R. HAMILTON, A. M., President, inthe Chair.

Major Henry D. Jones; Charles E. H. Orpen, M.D. ;
Thomas Andrews, M. D.; P. M. Murphy, Esq.; Rev. James
Wills ; Richard Palmer Williams, Esq. ; and Thomas Grubb,
Esq., were elected Members.

His Grace, the Archbishop of Dublin, V. P., having
taken the Chair pro tempore, the President communicated
to the Academy the first part of his researches on the
Dynamics of Light.

William Bald, Esq., Civil Engineer, read a paper en-
titled “ An Account of the Survey and Map of the County
of Mayo.”

The author commenced by giving a brief account of the
origin and progress of the construction of topographical maps
in Europe. In modern times, the first attempt at the con-
struction of topographical maps may be dated from the se-
venteenth century, and was due to the Swedes. Under Charles
the Ninth, a surveying department was organized, placed

246

under the direction of Bureus, and particularly encouraged
by Adolphus. . In 1684, the Swedes had completed the ge-
neral topographical map of Sweden; but it was kept secret,
and at the end of a century, they had only published some
parts of it. These maps were constructed for the purpose
of ameliorating the condition of several provinces of the
kingdom, which had been desolated by war. The Dutch
also commenced early to construct topographical maps.

The measurement of many arcs of the meridian to deter-
mine the figure of the earth, had very much extended geo-
detical operations, and had, in many cases, become the
elements on which topographical maps were based. ‘The
numerous geodetical surveys called into activity the inven-
tive powers of the ablest artists in Europe, and instruments
of extreme accuracy were produced ; and the skill of ob-
serving and determining angles kept pace with those im-
provements connected with this important branch of science.
The repeating principle due to the celebrated Tobias
Meyer, gave birth to Borda’s circle of repetition about 1789,
an instrument which has been connected with the most bril-
liant scientific operations which adorn the annals of the
eighteenth century.

Mr. Bald then showed to the Academy some specimens
of the new map of France, and noticed briefly the trigono-
metrical survey of England—the Down survey of Ireland—
the maritime surveys of Ireland—the county surveys, and
the bog surveys. He made some observations on the great
importance of accurate maps, especially to professional men
engaged in conducting public works, such as roads, canals;
river navigations, harbours, railways, supplying towns with
water, irrigations; to the geologist and miner, exploring
the strata, and mineral wealth of the country ; to the states-
man devising improvements, and developing its resources ;
and to the poor, by affording useful employment to the
working classes.

247

The author then alluded to the map of Egypt, which was
made during the period it was under the dominion of the
French republic, and which received from Buonaparte all
that protection and assistance, which so much distinguished
him on all occasions regarding the advancement of the works
of science. This map was engraved on fifty-three sheets of
copper, and the names are engraved both in Arabic and
French.

After this introductory account of the rise and present
state of the topographical Art, Mr. Bald proceeded to the
details connected with the survey of Mayo.

The instruments used in this survey, were a seven-inch
theodolite ; two five-inch theodolites, by Troughton; a
small theodolite, by Dollond ; and also a five-inch one by
the same artist. In taking the levels over the bogs, two of
Troughton’s best levels were used. The barometers were
made by Mr. Thomas Jones, of London. There were also
two plain tables, a chain for measuring base lines, a sextant
four inches radius, and two sextants, each ten inches radius,
divided to ten seconds for observing altitudes, one of which
was made by Troughton.

The proceedings of the geometrical details of the survey
were then given, and the mode of describing the rise and
fall of the ground, which was shaded on the map with
a depth of colour corresponding to the sines of the angles of
inclination. The irregularities of surface were simply de-
lineated by hatching lines, drawn in the direction of the de-
clivities, forming a series of normals, perpendicular to the
horizontal lines of equal level.

Dr. Smith read a paper (by Lieutenant Newenham;
R.N.), “on a Tumulus or Barrow, near Rush, County of
Dublin.”

The barrow, called Knocklea, or the Giant’s Hill, is

tuated on the edge of the cliff, about midway between the

248

village of Rush, County of Dublin, and the martello tower
to the northward, called Dromanick, and immediately in
front of Sir William Palmer’s residence, Kinure Park.

It appears to have been composed of quantities of boul-
der stones and earth heaped up into a conical form, and
sloping away to the base, which was square, as appears from
the eastern angle, which yet remains perfect. Within the
base of the mound, there was a circle formed of large stones
placed on their ends, and about one hundred paces in cir-
cumference. i

The farmer who rents the land on which it stands has
removed about one-half of the mound, for the sake of the
earth as a manure, and nearly one-half of the circle of stones
on the south side, for the purpose of building a wall, part of
which is erected on the stones forming the western side of
the circle. In the course of his depredations, he discovered
a passage which opened on the south side;* its entrance
was funnel-shaped, and the walls of this passage were
formed of flag stones placed on their ends, and roofed in
with the same. It was about eleven yards long, and one in
width; and led to a low chamber about eight feet long, and
six wide, which was situated nearly in the centre of the
barrow, and formed of stones in the same manner as the
passage.

The farmer removed all the stones forming the western
side of the passage, and in the course of his excavations,
found some human bones on the south side of the chamber,
and within the circle of stones. The lines of stones forming
the sides of the passage appear to continue on through the
mound towards the north side ; and a few feet below the pre-
sent surface of the barrow, a little to the north of the
chamber, there is a bed of periwinkle shells, about eight
inches thick, with some limpet and muscle shells intermixed ;

pee pS sui le
* Mr. Newenham thinks, that, as far as his observation has extended, the en
trance of all barrows is on the south side.

249

and beneath this bed of shells there is a quantity of rich dark
mould, with some reddish earth which has the appearance of.
being burned. A few human bones, and some bones of small
animals, were found in the earth beneath.

Outside the circle of stones, and on the very edge of the
cliff, near the western angle of the mound, there was found
a rudely-formed grave, containing a human skull, with the
bones of the arm, leg and thigh, which apparently had never
been disturbed; the bones of the back, ribs, &c., could not
be discovered.

There are several remains of entrenchments and smaller
mounds in the neighbourhood.

Circles of stones are found enclosing many similar bar-
rows in Ireland. At New Grange, near Dowth, in the
County of Louth, the circumference of one measured about
four hundred paces; and in a barrow near Drogheda, an
engineer officer found a gigantic skeleton, a pair of elks’
horns, and a spear, in an upright position: the horns
were above the skeleton. ‘There are many barrows in the
neighbourhood of Drogheda, which, if opened under the
direction of competent persons, would probably lead to
many very interesting discoveries.

The President gave an account of a singular appearance
of the clouds, observed on the 16th December, 1838, at the
Observatory of Trinity College, Dunsink. ‘They appeared,
for at least the last four hours of day light, to be arranged
in arches which converged very exactly to the N. E. and
S. W. points of the horizon; while the breaks or joints in
these arches were directed, though with less exactness, to
two other horizontal points, which seemed to be always op-
posite to each other, but ranged from N. W. and S. E. to
N. and S. Conjectures were offered with respect to the
cause of this appearance.

250

The following alteration in Chapter VIII. Section 3, of
the By-laws, was recommended by Council :—

** That in the Order of proceedings on the nights of
meeting, the reading of the Minutes shall precede the Ad-
mission of new Members.”

Adopted by the Academy.

The following alteration in Chapter IX. Section 3, of
the By-laws, was recommended by Council, on the sugges-
tion of the Committee of Publication :—

‘“‘ That it is expedient to transfer to the Committees of
Science, Polite Literature, and Antiquities, the duty of re-
porting, in future, on papers offered for publication in the —
Transactions.”

Adopted by the Academy.

It was Resolved,—“ That the mein request, that
any alteration in a By-law, proposed by the Couneil,
shall be stated in full to the Members of the Acade-
my, together. with the existing By-law, so proposed to be
amended.”

The Academy then adjourned to Monday, the 28th of
January.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de l Aca-
demie des Sciences. Par MM. les Secretaires Perpetuels.
Tome Sixiéme; premier Semestre, Janvier— Juin, 1838;
et second Semestre, Nos. 21—25. Presented by the
Academy.

Annales Academix Gandavensis, §c. §c. 1817-1828.
11 Vols. Presented by the Academy.

Amputations dans la Contiguite des Membres. Par le
Docteur Ch. Phillips, de Liége. Presented by the Author.

Notice sur la Vanille Indigéne. Par Ch. Morren. Pre-
sented by the Author.

251

Morphologie des Ascidies. Par M.Ch. Morren. Pre-
sented by the same.

Quelques Remarques sur ? Anatomie de ? Ascaride Lom-
bricoide. Par Ch. Morren. Presented by the same.

Proceedings of the Royal Society. No. 35, 1838. Pre-
sented by the Society.

Address of his Royal Highness the Duke of Sussex,
K.G., §c., the President. Read at the Anniversary Meet-
ing of the Royal Society, on Friday, November 30, 1838.
Presented by the same.

Proceedings of the American Philosophical Society.
Vol. I. No. 4. Presented by the Society.

Eulogy on Nathaniel Bowditch, LL.D., President of the
American Academy of Arts and Sciences ; including an Ana-
lysis of his Scientific Publications. By John Pickering,
Corresponding Secretary of the Academy. Presented by
the same.

An Eulogy on the Life and Character of Nathaniel Bow-
ditch, LL.D., F.R.S. By Daniel Appleton White. Pre-
sented by the same.

A Discourse on the Life and Character of the Honourable
Nathaniel Bowditch, LL.D., F.R.S. By Alexander Young.
Presented by the same.

Religion of the ancient Irish Saints, before A. D. 600.
By Henry J. Monck Mason, LL.D. Presented by the
Author.

Historical Essay on the first Publication of Sir Isaac
Newton’s Principia. By Stephen Peter Rigaud, M.A.,
F.R.S., Hon. M.R.I.A., &c. Presented by the Author.

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SRT: eB RET Soeth aH.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1839. No. 15.

January 28.

SIR Wm. R. HAMILTON, A. M., President, in the Chair.

Mr. Ball read a paper on the Remains of Oxen found in
the Bogs of Ireland.

Having alluded to the occurrence of fossil remains of
oxen in Britain, and the existence of the Auroch or Wild
Ox, in some parks in that country, he remarked on the
old and generally received opinion, that Ireland could not
furnish any evidence of having ever possessed an indigenous
ex; and he stated, that a specimen which he received from
the sub-marine forest, in the Bay of Youghal, seemed to have
been the core of a horn of the fossil ox, often found in Britain,
and supposed to have been the Urus ; but this specimen having
been lost, he alluded to it, to direct the attention of the Aca-
demy to the subject, in the hope of having his view confirmed.
He then entered upon the principal object of his paper, which
was to show, that the remains of oxen found at considerable
depths in bogs in Westmeath, Tyrone, and Longford, be-
longed to a variety or race, differing very remarkably from
any noticed in Cuvier’s “‘ Ossemens Fossiles,” or any other
work with which he was acquainted. He concluded by ex-
pressing a conviction, that Ireland had possessed at least one
native race of oxen, distinguished by the convexity of the
upper part of the forehead, by its great proportionate length,
and by the shortness and downward direction of the horns.
As this fact seems to have escaped altogether the notice of

Z

254

British and continental naturalists, and as analogy in the
case of other Irish mammals justified the view, he urged the
great probability of the race in question proving to be one
peculiar to Ireland.

Mr. Ball exhibited specimens and drawings, and solicited
the co-operation of Members of the Academy, in effecting a
perfect elucidation of the subject, by collecting specimens
from the bogs of the country.

Dr. Kane read an account of a substance which has
hitherto been confounded with white precipitate. It is
formed by precipitating in the cold, a solution of sal-alem-
broth by carbonate of potash, or by boiling true white pre-
cipitate in a strong solution of sal-ammoniac. ‘The compo-
sition of this body is expressed by the formula Hgc/ + NH,
and Dr. Kane considers it as intermediate between true
white precipitate and sal-ammoniac.

This substance was noticed independently by Professor
Woehler, as being found in commerce under the name of
white precipitate. He, however, recommended it to the at-
tention of chemists without analyzing it.

Rev. H. Lloyd, V. P., read a ‘ Note of Observations
made during the remarkable Aurora of the 19th inst.”

Mr. Lloyd commenced by stating, that the approach of
this beautiful phenomenon was indicated in Dublin, at an
early hour, by the disturbance of the magnets in the Ob-
servatory. At five o'clock, both magnetometers testified the
setting in of what Humboldt calls a ‘‘ magnetical hurricane ;”
the disturbance in declination amounting, in the course of a
quarter of an hour, to 20.7 minutes, while the corresponding
change in the intensity of the horizontal component of the
magnetic force, was 0092, or nearly the one-hundredth part
of the whole.

Shortly before 10 o’clock, a broad and brilliant arch was

255°. *

formed, the lower limb of which was beautifully defined.
The remarkable feature in this phenomenon was the éntense
blackness of the sky beneath the arch, as contrasted with
that exterior to it. The darkness of this space was such,
as to resemble a dense cloud, fringed by the auroral light ;
and the doubt was suggested, whether the dark cloud noticed
by many observers, in connexion with aurora, may not have
been an appearance of the same kind, though less regular in its
outline. In the aurora of the 19th, the blackness of the
space enclosed by the arch was certainly not due to the
presence of a cloud, for the stars were distinctly visible in it.
Mr. Lloyd stated, that he was so much interested in this
part of the phenomenon, as to lose the opportunity of ob-
taining a measure of the altitude of the arch.

Soon after 10 o’clock, the arch began to break up into
streamers. Its appearance at this period was such as is
represented in the subjoined sketch.

From this time, until half past eleven o’clock, Mr. Lloyd
took no notes of the appearances, having been engaged in

Ze

256

watching the motions of the magnetometers in the Obser-
vatory-

At half-past eleven o'clock, the streamers were very
splendid, and covered the whole sky, appearing to spring,
however, chiefly from the N. E. They were remarkable for
the intensity of their light ; the irregularity of their forms (sel-
dom affecting the usual rectilinear form ;) and their incessant
dancing motion. At first, the flashes of light appeared
in broad irregular masses, at considerable intervals over the
sky, like scattered clouds illuminated by the moon, except
that their appearance was momentary; or (as they have been
described) like the jets of illuminated vapour, shot from
the boiler of a locomotive engine. About twelve o'clock,
they spread themselves over the face of the sky, and ex-
hibited a nearer approach to their usual form. At this
period, a distinct point of convergence, a little to the S. E.
of the zenith, was occasionally exhibited; and a marked
contortion of the auroral clouds, at this point, showed the
tendency to the formation of the corona. 'There was like-
wise a stationary luminous cloud, to the S. E., which ap-
peared to be connected with the phenomenon.

After twelve o'clock, the brilliancy of the phenomenon
in the upper part of the sky gradually lessened ; but a very
intense auroral light, with streamers, still remained in the
N. W. The atmosphere was remarkably clear, and the stars
very bright; the cloud-like patches of the aurora not
seeming to present any obstacle to the transmitted light.
There was a cold cutting wind, which came in gusts; and
it seemed as if these gusts were simultaneous with the flashes
of the aurora.

Mr. Lloyd then presented a table, exhibiting the results
of observation with the two magnetometers, one of which mea-
sures the changes of declination, and the other those of the
horizontal part of the earth’s magnetic force. The observa-
tions commenced at 10" 25™, and were continued, at intervals

257

of three minutes, for one hour. The table contained the
direct results of observation with the two instruments; the
differences of these results and the means of the day, (or
the disturbances in declination and horizontal force,) esti-
mated in parts of the scale; and the same differences re-
duced to their proper measures. The extreme disturbance
in declination, amounted to 17’.9; and that of the horizon-
tal force to .0127. The changes of the horizontal com-
ponent of the force arising partly from changes of the total
force, and partly from changes of inclination, and the part
due to the latter being, in high magnetic latitudes, much
the greater, it is manifest that the changes of inclina-
tion may be deduced, approximately, from those of the ho-
rizontal force, on the assumption that the actual force re-
mains unvaried. The changes ofinclination, thus deduced,
were given in another column of the table.

The numerical values of the changes of declination and
inclination thus obtained, were laid down in charts, so as to
represent graphically the progress of the disturbance of each
of the elements of the magnetic. direction. In a third chart
the combined effect of the two disturbances was represented,
so as to exhibit the successive positions of the pole of the
needle, supposed free to move in every direction. From this
it appeared, that in the present instance, the effect of the
auroral disturbance upon the resultant directionof the earth’s
magnetic force, has been to impress upon the pole of the
needle a kind of epicycloidal movement. It will remain for
future observations to determine whether or not this is a
general law; the light that such an inquiry must throw on
the nature of the disturbance need not be insisted on.

The aurora appears to have been frequent about this
period. Two days after this observation, on the 21st, at
nine o'clock in the evening, the magnetometers were again
disturbed. The extreme positions observed, occurred at
9 10", and 9" 35"; and in this interval the change of decli-

258

nation amounted to 53’.8, while the change of the horizontal
force was .004. At the time of this observation, the sky was
overcast with light fleecy clouds; but in the course of the
evening the aurora was seen.

The following additional notes were furnished by Mr.
Bergin.

*‘ The aurora was first seen about half past five o’clock
Pp. M. as a luminous arched bank, on the N. W. horizon,
extending about 30° horizontally, and having a versed sine of
about 15° vertical, with occasional very thin, luminous, cloud-
like patches, stretching to the zenith. It was some mi-
nutes before I could be certain, whether it was aurora or
only vapoury clouds. About half an hour afterwards, there
was a very well defined luminous arch over the bank, and
parallel to it, perhaps 10° higher, with motionless stream-
ers from the bank towards the arch. From the summit of the
latter there sprung a vertical arch, (very faint,) which ex-
tended nearly to the zenith, where there was a faint circu-
lar patch (corona?)

“The space between the bank and the horizontal arch
_ was intensely dark ; yet that the darkness was not caused
_ by clouds, was evident, as a few stars were distinctly visible
within this space. At this time there was a very remarka-
ble brush of light, commencing apparently at the centre star
of Orion’s belt, diverging southward for 10° or 12°, and
slightly inclined upwards: this brush was perfectly motion-
less, and remained altogether unchanged during an interval
of five minutes or thereabouts; my attention was then fora
short time directed to the arch, and when I again looked
towards Orion, the brush had entirely disappeared.

** About nine o’clock, the horizontal and vertical arches,
as well as the coronal patch, had quite disappeared; or
rather they had united with the bank first described.

“At half past ten the appearance had again changed,

259

and presented part of an arch based upon the upper part
of another,—this latter throwing out singularly brilliant
coruscating streamers towards the zenith, while it rested on
luminous clouds, near the horizon, somewhat in this manner:

About twelve o’clock I could only see a luminous cloud, not
very extensive, towards the N. W., with the ordinary flashing
and playing masses of light.

“The colour of the aurora, when first seen, was slightly
reddish, afterwards decidedly yellow; the streamers were
occasionally very brilliant and perfectly white.”

The subject of the aurora having been brought before

the Academy, Dr. Apjohn took the opportunity of describ-
ing a very beautiful phenomenon of the kind, which had
been observed on the 16th of last September, at Sunville,
in the county of Limerick. It was first noticed at about
half past eight o’clock in the evening, and did not disappear
for very nearly an hour. It was first seen in the southern
part of the hemisphere, and consisted ofa number of stream-
ers of variable brilliancy, shooting upwards in vertical cir-
cles, or, more strictly speaking, converging towards a point
which appeared a few degrees to the south-east of the
zenith. They did not in any case originate from the hori-

260

zon, but from points having an altitude of about 40°; and

they very frequently extended upwards to their point of
intersection, producing there a light of considerable inten-

sity. The illuminated sector of the sky, supposing it pro-

longed to the horizon, subtended an angle of about 30°.

The most remarkable circumstance connected with this —
aurora was the following. About nine o'clock, it began

to move slowly round, taking an easterly direction; and

when, in the course of fifteen or twenty minutes, it attained

a north-westerly bearing, the sky was lighted up on every

side with singular brilliancy. The appearance which now

presented itself, is best conveyed by stating, that it was pre-

cisely such as would be produced by the extension, at the

same instant, of the aurora already described, through every
point ofazimuth. This magnificent illumination lasted only

about a minute, but left behind it, very nearly due west, a
fasciculus of beams quite similar to those which first attracted
attention.

The night was remarkably fine and still, having been
preceded by a day of unusual warmth and sunshine. The
sky was not destitute of clouds, but they had a considera-
ble elevation, were small and scattered, and were penetrated
by the light of the stars, which were visible in considerable
numbers.

Mr. George Downes read extracts of a second letter
from Professor Rafn, Secretary to the Royal Society of
Northern Antiquaries of Copenhagen. In this letter Pro-
fessor Rafn suggested that, as his researches relative to Ame-
rica appeared to be, as yet, but little known in Ireland, it
might perhaps be advisable, that his “‘ Memoir on the Dis-
covery of America in the tenth Century,” already published
at Copenhagen in the Antiquitates Americane, should be
reprinted in the Transactions of the Academy, with an in-
troduction, which he proposed to furnish, and with some ad-

261

ditional remarks on “ Great Ireland.” Professor Rafn took
occasion also to solicit contributions of books or money, for
a public library which had been established by himself, in
- 1818, at Reikiavik, the capital of Iceland, “ whose inhabi-
tants,” he says, “have but little opportunity of gratifying
their thirst for information.” The library now numbers —
7500 volumes, and possesses a permanent fund of 1500 rixdol-
lars, for which it is partly indebted to “‘some noble-minded
Englishmen.” With reference to the subject of this letter,
Mr. Downes remarked, that the island for which Professor
Rafn felt so much interest, had peculiar claims on the sym-
pathy of Irishmen, as having been, like their own island, a
place of refuge for literature, when banished from the con-
tinent of Europe. He then renewed his application to the
Academy for a contribution to the funds of the Royal So-
ciety of Northern Antiquaries, observing, that they had
shown great readiness to lend their aid in the elucidation of
Irish antiquities, which indeed were intimately connected
with their own ; and that a work, which they now had in con-
templation, was specially devoted to the antiquities of Great
Britain and Ireland ; a work, however, of such magnitude,
that it might never see the light, unless a liberal supply
could be raised for the funds of the Society.
It was RESOLVED, that Mr. Downes be requested to com-
municate with the Council on this subject.

ResoLveD,—on the recommendation of Council, that in
the By-law, Chap. VIII. Sec. 5. the words “ altered or re-
pealed” be inserted after the word “ confirmed.”

The Secretary of Council stated, that the Council, in
consequence of the expressed wish of the Academy, had
resolved, “ that any alterations in By-laws, proposed by the >
Council, shall be stated in full to the Members of the Aca-
demy, together with the existing By-law, so proposed to be
amended ; and that this notice shall be given én print.”

262

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de l Acade-
mie des Sciences. Par. MM. les Sécretaires Perpetuels. -
Second Semestre, Nos. 26 and 27. Presented by the Aca-
demy.

Memorie della Reale Accademia delle Scienze di Torino.
Tome XL. Presented by the Academy.

Transactions of the Society of Civil Engineers. Vol. II.
Presented by the Society.

Report of a Committee of the Royal Society, on the Pro-
priety of recommending to her Majesty's Government, the Es-
tablishment of fixed Magnetic Observatories, and the Equip-
ment of a Naval Expedition for Magnetic Observations in the
Antarctic Seas ; together with the Resolutions adopted on that
Report by the Council of the Royal Society. Present-
ed by the Society.

Rough Sketches, intended to aid in developing the Natural
History of the Seals, (Phocide) of the British Islands. By
R. Ball, Esq. Presented by the Author.

_ The Expediency and Facility of establishing Metrolo-
gical and Monetary Systems throughout India, on a scientific
and permanent Basis, grounded on an analytical Review
of the Weights, Measures, and Coins of India, &c. §c.

By Captain T. B. Jervis. Presented by the Author.

The Indian Review, and Journal of Foreign Science and
the Arts. Edited by Frederick Corbyn, Esq. Vol. II. Pre-
sented by the Editor.

February 11.

SIR Wu. R. HAMILTON, A. M., President, in the Chair.

The Rev. Robert Vickers Dixon, F.T.C., was elected a
Member of the Academy.

263

Mr. George Smith presented to the Academy an ori-
ginal portrait of General Vallancey, by Chinnery.

The thanks of the Academy were voted to Mr. Smith
for his valuable donation.

Mr. William Bald, civil engineer, read a paper, contain-
an account of his models of the Island of Achil, Clare Island,
and the south western district of Mayo, which comprises
the greater part of the barony of Murrisk, and a portion of
the barony of Burrishoole.

After an introduction, in which the author calls atten-
tion to modelling, as the best mode of representing the rise
and fall of ground, and makes some remarks on the unde-
served neglect which the subject has hitherto met with in
this country, he proceeds to state, that his model of Clare
Island was made on a scale of eight inches to the Irish mile ;
and that the models of Achil Island, and Murrisk Barony,
were on scales of four inches to the English mile. The ver-
tical scales were the same as the horizontal. The model
of the barony of Murrisk is at present deposited in the
house of the Royal Dublin Society. The original model
of Clare Island is in the possession of the Royal Society
of Edinburgh; and the model of Achil has been deposit-
ed in the Museum of the College of Edinburgh. The
model of Murrisk represents the area of a country con-
taining nearlytwo hundred square miles ; that of Achil repre-
sents a country containing about fifty-eight square miles ;
and Clare Island is about four English miles long, by two
and a quarter in its greatest breadth. These models were
constructed with a composition of putty, white lead, and
cork. The paper gives an account in detail of the mode of
their construction.

In ascertaining the levels of the country, Mr. Bald re-
commends that lines of equal level be adopted, and also

264

transverse sections made. He states that neither Ben
Nevis in Scotland, Snowdon in Wales, nor Macgillycuddie’s
Reeks in Ireland, have had their heights ascertained by
actual levelling ; and he observes, that were these heights
accurately determined, further knowledge might then be ob-
tained regarding refraction, and the measurement of altitudes
by the barometer. A small map of the island of Inish Turk,
on which are delineated lines of equal level, accompanies
the paper.

In conclusion, Mr. Bald observes, that a model of a
country in the hands of the topographic, military, civil, or
mining engineer, could be applied to a variety of useful
purposes; and particularly that it would enable young men
to shade accurately topographic maps, a thing that has not
yet, to his knowledge, been systematically attended to in any
of the institutions of Great Britain or Ireland.

Rey. H. Lloyd, V. P., read a ‘paper ‘ on the relative
Position of three Magnets, in a Magnetical Observatory.”

Itis a problem of much importance, in connexion with the
arrangement of a magnetical observatory, to determine the
relative position of the magnetical instruments in such a man-
ner, that their mutual action may be either absolutely null,
or at least, readily calculable. Such was stated by the
author to be the object of the investigation now laid before
the Academy.

In the case of two horizontal magnets, one of which (in-
tended for observations of declination) is in the magnetic me-
ridian, and the other (used for observations of horizontal in-
tensity) is in the perpendicular plane, there is nothing to
compensate the action of each magnet on the other. The
best thing that can be done in this case, is to determine the
position of the second magnet in such a manner, that the
direction of its action on the first shall coincide with the
magnetic meridian. In such case, the position of the first

265

magnet will be undisturbed by the second, so as to give the
absolute declination truly; and, as to the variations of the
declination, it is manifest that they will be thereby increased
or diminished in a given ratio; so that the true variations
will be obtained by simply altering the coefficient of the
scale. When the above-mentioned condition is introduced
into the equation which determines the direction of the re-
sultant force exerted by one magnet on another, (the length
of the magnets being supposed small in comparison with
the distance between them,) we find, for the azimuth of the
line connecting the two magnets, referred to the magnetic
meridian,
are (‘an = 73) = 1359 16;

This result has been already obtained by Gauss and Weber.

It is manifest that, in this case, the action of the first
magnet on the second will not take place, either in the mag-
netic meridian, or in the plane perpendicular to it; so that
the second magnet is necessarily disturbed. With two mag-
nets, accordingly, it is impossible to avoid the effects of
mutual action. The case is different, however, when a
third magnet is introduced. It is then possible to annul
completely all action, with the exception of that exerted
on the third magnet by the first and second; and this, in
the case under consideration, is destroyed by the nature of
the suspension.

The third magnet about to be employed in the Dublin
Observatory is intended for the observation of the vertical
component of the. magnetic force. It is a bar supported on
knife-edges, capable of motion in a vertical plane, and
brought into the horizontal position by means of a weight.
The three instruments being in the same horizontal plane,
it is manifest that the action of the first and second on the
third must take place in that plane; and this action can
have no effect in disturbing the magnet, its motion being

266

confined to the vertical plane. It is only necessary to con-
sider, therefore, the action on the first and second magnets.

The author then proceeded to the conditions of equili-
brium of these actions, which were expressed by four
equations, containing four arbitrary angles; so that this
equilibrium is, in general, attainable, by suitably deter-
mining the position of the three magnets, whatever be their
relative intensities.

In practice, however, it will seldom happen, that we can
regard as arbitrary all the four angles which enter these
equations, one or more of them being, in general, determined
by some circumstance connected with the locality. In such
case the complete destruction. of all action is no longer pos-
sible; and we must look for some other solution of the pro-
blem of mutual interference.

Next to the complete destruction of all action, the most
desirable course is to give to the resultant action such
a direction, that its effect may be readily computed and
allowed for. In the case of the declination bar, it is easily
seen that this direction is the magnetic meridian itself;
the mean position of the bar being thereby wnaltered, and
the variations of its position only increased or diminished in
a given ratio. By means of a simple investigation it is
shown, that the same thing is true of the horizontal inten-
sity bar; and that, in order that the variations of declination
may not be mixed up with those of force, the resultant force
exerted upon this magnet by the other two must lie in the
magnetic meridian. 'The problem, therefore, is reduced to
this:—to determine the position of the three magnets
A, B, and C, in such a manner, that the resultant actions ex-
erted upon a and B, respectively, by the other two, shall
lie in the magnetic meridian.

The solution of this problem was shown by the author
to be contained in the two following equations:

267

sin’ (a + 3) [3 sin (uw +v—2a) + sin (w—v)]
+2qsin°B (8sin?u—1) = 0.
sin*(a +) [3 sin (« +v +23) + sin(u—v)]
+6psin® a. sin ucos w= 0.
in which a and 6 denote the angles Bac and <ABc, of the
triangle formed by the lines joining the three magnets;
wand v, the angles which the directions of the magnets,
A and c, make with the line aB; and p and q the ratios of
the forces of the magnets a and B to that of the third mag-
net c, at the unit of distance.

The paper concluded with the application of the for-
mulz to some remarkable cases,—as, when the three mag-
nets are in the same right line; when the line joining two
of them is in the magnetic meridian, or perpendicular to it;
&e.

The Chair having been taken, pro tempore, by his Grace
the Archbishop of Dublin, V. P., the President continued
his account of his researches in the theory of light.

Asa specimen of the problems which he had lately con-
sidered and resolved, the following question was stated :—
An indefinite series of equal and equally distant particles,
. ses M4, Mo, M,--., situated in the axis of x, at the
points....—1,0,+1,...., being supposed to receive,
at the time 0, any very small transversal displacements
= Y-1,0 Yo,0> Yi,09*+*s and any very small transversal

velocities .-. YY oo Y's,09 °°
mine their displacements.--¥_, 45 %,» Yo ++ * for any
other time #; each particle being supposed to attract the
one which immediately precedes or follows it in the series,
with an energy = a”, and to have no sensible influence on
any of the more distant particles. This problem may be
considered as equivalent to that of integrating generally the
equation in mixed differences,

., it is required to deter-

268

Yt =@ (Ye 41,t7 2Y2,t aly Yen) s (1)
which may also be thus written:
Ls (@A,) Ly
(5) tee = SEE Yaw (1)
The general integral required, may be thus written:
WAZ t —l E }
i ears ion ea (a? (y2,0+ tY's,o)3 (2)

an expression which may be developed into the sum of two
series, as follows,
soe
2 Ye Ne Yenrotpoay Oe Yn 2,9 + &e.

Bp qtatyy ; ak e
+ tz, ——. fen.ot Tagen 7 tee of
and may be put under this other form,

2 a 7
Yet = = MALU bir olry ‘fi d0 cos (2/6) cos (2 at sin 0)
Tv

oa) 2
+ = Daeg ag! oly st Py d0 cos(2/0) cosec @ sin (2 at sin@); (2)"
v9 0

the first line of (2)’ or (2)" expressing the effect of the initial
displacements, and the second line expressing the effect of
the initial velocities, for all possible suppositions respecting
these initial data, or. for all possible forms of the two arbi-
trary functions'y, , and 7’, ,.

Supposing now that these arbitrary forms or initial con-
ditions are such, that

Tv - TW. T
Yx,y = NVETS 2x a and y’,,, = — 2ansin~ sin2a-, (3)

for all values of the integer x between the limits 0 and —in,
nm and z being positive and large, but finite integer numbers,

269

and that for all other values of x the functions y, , and 9’, ,
vanish: which is equivalent to supposing that at the origin
of ¢, and for a large number z of wave-lengths (each = x) be-
hind the origin of z, the displacements and velocities of the
particles are such as to agree with the following law of un-
dulatory vibration,

T . 7
Y= 7 Vers (22 a 2 at sin a (3)’

but that all the other particles are, at that moment, at rest :
it is required to determine the motion which will ensue, as
a consequence of these initial conditions. The solution is
expressed by the following formula, which is a rigorous de-
duction from the ae in mixed differences (1) :

. =2( : “yt sinin® cos(2x8 + in0—2at sin 8) Se (4)

Tw
% sin? cos 9—cos —

an expression which tends indefinitely to become

aes 5 vers (22% —2atsin =

— (sin =, oo sin (200— —2aé sin 6) a0, (4

sin 0 (cos 6—cos =)

as the number 2 increases without limit. The approximate
values are discussed, which these rigorous integrals acquire,
when the value of ¢ is large. It is found that a vibration, of
which the phase and the amplitude agree with the law (3)’,
is propagated forward, but not backward, so as to agitate
successively new and more distant particles, (and to leave
successively others at rest, if ¢ be finite,) with a velocity of

. T ° .
progress which is expressed by @ cos a and which is there-
fore less, by a finite though small amount, than the velocity

_of passage a = sin = * of any given phase, from one vibrating

2A

270

particle to another within that extent of the series which is
already fully agitated. In other words, the communicated
vibration does not attain a sensible amplitude, until a finite
interval of time has elapsed from the moment when one
should expect it to begin, judging only by the law of the
propagation of phase through an indefinite series of particles,
which are all in vibration already. A small disturbance, dis-
tinct from the vibration (3)’, is also propagated, backward as
well as forward, with a velocity = a, independent of the
length of the wave. And all these propagations are accom-
panied with a small degree of terminal diffusion, which, after
avery long time, renders all the displacements insensible, if
the number 2, however large, be finite, that is, if the vibra-
tion be originally limited to any finite number of particles.

Dr. Apjohn read a paper by George James Knox, Esq.
on the Direction and Mode of Propagation of the electric
Force traversing Media which do not undergo Electrolyza-
tion.”

In the commencement of this paper, the author details
experiments, which appear to him to justify the inference,
that when an electric circuit is completed through water or
melted phosphorus, the current passes directly through the
substance of these media, but that when, for these, a metal
such as lead is substituted, the electricity moves exclusively
along its surface. He next considers the source and mode
of propagation of the electric force, developed in the pile,
and after a brief review of the theories and experiments of
Davy, Faraday, and Becquerel, arrives at the following con-.
clusion, viz. that an electric current originates in a natural
electro-inductive power of bodies when brought into contact,
which affects the circumambient ether of each particle, and
is continued by alternate states of induction and equilibrium ;
the amplitude of the oscillations of the electrical ether con-

271

stituting the quantity, as their rapidity constitutes the inten-
sity, of the electrical current.

Dr. Aquilla Smith exhibited to the Academy, an ancient
Trish bell, of a square form, found near Fintona in the county

of Tyrone.

Ir WAS RESOLVED, (on the recommendation of Council,)
‘that any Member of the Academy, who proposes the name
ofa candidate, shall give, in writing, the grounds on which he
recommends such candidate for admission; and that such
statement shall be read by the President from the chair pre-
vious to the ballot.”

Ir WAS RESOLVED, (on the recommendation of Council,)
‘that the following shall, in future, be the mode of balloting
in the election of Members :—

‘‘Members balloting are to mark with an asterisk the
name of the candidate or candidates whom they desire to
admit ; to draw a line through the name of the candidate or
candidates whom they wish to reject ; and to leave the name
unmarked when they do not vote at all.”

DONATIONS.

Comptes Rendus Hebdomadaires des Seances del Academie
des Sciences. Par MM. les Secretaires Perpetuels. No. I.
Premier Semestre, 1839. Presented by the Academy.

An original Portrait of General Vallancey, by Chinnery.
Presented by George Smith, Esq.

w®
iad
©

272

February 25.

SIR Wm. R. HAMILTON, A. M., President, in the Chair.

Rev. H. Lloyd read a letter which he had recently re-
ceived from M. D’Abbadie, relating to his scientific expedi-
tion in Africa. The following is an extract.

« Apwa, (AsyssinrA,) July 24th, 1838,

“Our voyage to Abyssinia (my brother accompanied
me) was chiefly undertaken in order to learn the principal
languages of that country, and the best manner of travelling
in it, with a view of returning to Europe, there to prepare a
complete and well directed expedition. We left Cairo in
December 1837, and proceeded by Keneh and Ckosair to
Djiddah, where I took a great deal of pains to correct, by
local information, the nomenclature of places on the Red
Sea. We next proceeded to Massawwa, where I remained
alone for nearly two months, studying the Hababi tongue, a
Semitic language, nearly allied to Ethiopic, and spoken
from Ansky Bay almost as far as Sawakim. The customs
and manners of the Habab tribes afforded me several proofs
of their Arabian origin. On my brother’s return from the
high lands of Abyssinia, I proceeded with him into that
country, carrying our baggage, instruments, &c. Unfor-
tunately we were detained so long on the road, by a chain
of untoward circumstances, that the rainy season set in be-
fore we reached this place. After a forced stay of twenty
days, and a tiresome journey of twenty more, we arrived
safely in Goander, the splendid but fallen capital of Ethio-
pia. Here I made myself master of the Amarfia language,
at least enough to travel without an interpreter, and got
some valuable information on the sources of the White Nile.
Our object being now attained, it was high time to turn
back before the swollen waters of the Tacazay had com-

273

pletely shut up the road towards the sea-coast. But my
brother could never be induced to give up the game that
seemed already within his grasp; and when we parted at
Goander, he was already directing his steps to the unknown
regions of Damoh, Enarea, Kafa, and Djandjow. May the
Almighty God look with favour on the daring and lonely
traveller !

*‘ T need not tell you that all my barometers were shiver-
ed to atoms long before I crossed the mountain passes of
Abyssinia. I was obliged to have recourse to observations
on the temperature of boiling water, for which I was pro-
vided with an excellent and delicate thermometer. As au-
thors do not exactly agree in the manner of calculating these
observations, I shall here insert some of the original entries.
They will throw some light on the long disputed question of
the height of Abyssinian mountains.

Boiling Water. Air.
““ Mountains near Halay (primitive rocks) 29th March,6 a.m. 939.9 14°.4

Adwa id. fs : 5 - 10th May, 8a.m. 94.15 25.3.
Teraséga (east bank of the Tacazay) 19th May, 83 4.M. 95.18 25.8
Tacazay, (closeto the water) . . 20th May, 9am. 97.30 25.0
Amodjagi, (west bank of the Tacazay) 27th May, 6aA.M. 90.80 20.0
Goander, F “ : ; ., oth Juneseevers mM. 993.25 22.2
Kaba, (village near Samen) - - SthJuly, 5a.mM. 91.35 18.3

Ewari, (on Mount Bawhit) trap rocks 7th July, Noon, 89.56 24.1

‘The summit of Mount Bawhit is at least 1800 feet above
the village of Ewari. This Mount Bawhit is, after Amba Hai,
the highest mountain in Abyssinia. When I crossed part of
it, the ground was covered with unmelted hail, which looked
at a distance like snow. This observation conciliates in
some measure the conflicting testimonies of Bruce and

Salt.”
‘¢ ALEXANDRIA, 3lst December, 1838.
‘‘T had deferred closing this, until I could discover some
means of forwarding it to Europe. Unfortunately, after a
long and fruitless delay, | was compelled to be my own mes-

274

senger as far as Egypt. On my way home, I sailed from
Massawwa to Mokha, where I collected several valuable re-
marks on the language and country of the Somali. During
three tedious months on the Red Sea, I succeeded in learn-
the Ilmorma language, which is spoken through immense
tracts of central Africa. Iam now hastening to Europe,
where I shall lay an abstract of my journey before the sci-
entific world.”

Mr. Lloyd made a few remarks on the heights of the
mountains, as determined by the preceding observations.

Mr. Petrie exhibited to the Academy two golden Torques
or collars, found about twenty-five years ago onthe Hill of
Tara, the residence of the Irish monarchs anterior to the
sixth century. The first is five feet seven inches in length,
and weighs 27 oz. 9 dwts. The second is five feet six inches
in length, but weighs only 120z. 6dwts. These Torques
are of a screw or spiral pattern, as will be seen from the
subjoined wood cuts; and though the design is rude, the

workmanship is of great beauty. Torques of similar size
and pattern have been frequently found in Ireland, and

275

are often accompanied by armille or bracelets of the same
description.

The term Torgues, by which antiquarians usually desig-
nate these ornaments, is one of frequent occurrence in the
classic authors. The word is generally derived from the Cel-
tic Tore, a twisted collar, or perhaps, more correctly, a twisted
circular ornament of any kind, as the ancient Irish called a
collar or neck-chain mun-tore. And since the Latin verb ¢or-
queo has no cognate in Greek, it is probably formed from
the same Celtic root.

Collars of this kind seem to have been common to all the
Celtic nations, as we find from ancient writers. Livy tells
us, that Publius Cornelius, in his triumph over the Boii, a
Gallic nation, collected, among the spoils, no less than
1470 Torques: and we find in Propertius, that Virdumarus
king of the Gauls, wore such an ornament. Dio Cassius
notices a Tore of this description, as ornamenting the per-
son of the British Queen Boadicea; and even within a few
centuries of the present time, a Welsh Prince was called Lle-
wellin aur dorchag, or Liewellin of the Golden Tore. The
Torques found in France and Wales are exactly similar to the

276

Irish : a fine one found near Harlech, in the year 1692, is
preserved in the Mostyn family in Flintshire. .

It has been supposed by some antiquarians, that the use
of these ornaments was derived from the Romans. But the
great number discovered in Ireland is opposed to such a
conjecture, and we may with much greater probability refer
them to a Celtic origin. It does not appear that they were
generally worn by the Romans; and the very appellation
Torquatus, which was bestowed on Titus Manlius, from the
Golden Tore taken by him from a Gaul, whom he slew in the
year of Rome 393, and which was continued as a surname in
his family, seems to indicate, that the Zorques was not
familiar to the Romans at the time.

The Rev. H. Lloyd, V. P., laid on the table the séereo-
scope of Professor Wheatstone, and briefly explained the
information which it afforded on the laws of binocular vision.

The President delivered the following Address to the
Academy.

I have now the honour to inform you, that your Council, in the
exercise of the discretion entrusted to them by you, have taken into
their consideration, since the commencement of the present session,
the various papers which had been for a few years past communicated
to our Transactions, on several different subjects, in order to deter-
mine whether any and which of those papers should be distinguished
by the award of a Cunningham Medal: and that the medal for the
most important Paper in Physics, communicated to us during the
three years ending in March, 1838, has been adjudged to Dr. Apjohn,
for his Essay on a New Method of investigating the Specific Heats of
the Gases, published in the First Part of the Eighteenth Volume of
the Transactions of this Academy.

The importance of the study of what are called the imponderable
agents, is known to all physical inquirers. Indeed it would appear,
that as the scientific history of Newton, and of his successors during’

207

the century which followed the publication of his Principles of Natu-
ral Philosophy, is connected mainly with the establishment of the law
of universal gravitation, and with the deduction of its chief conse-
quences; so are the mathematical and physical researches of the
present age likely to be associated, for the most part, with the study
of light and heat and electricity, and of their causes, effects, and con-
nexions. Whatever, then, whether on the practical or on the the-
oretical side, in the inductive or the deductive way, may serve to
extend or to improve the knowledge of these powerful and subtle
agents or states of body, which are always and everywhere present,
but always and everywhere varying, and which seem to be concerned
in all the phenomena of the whole material world, must be received
by scientific men as a welcome and valuable acquisition.

Among researches upon heat, the highest rank is, (I suppose, )
by common assent, assigned to such works as those of Fourier and
Poisson, which bring this part of physics within the domain of ma-
thematical analysis. That such reduction, and to such extent, is pos-
sible, is itself a high fact in the intellectual history of man; and from
the contemplation of this fact, combined with that of the analogous
success which it was allowed to Newton to attain in the study of
universal gravitation, we derive a new encouragement to adopt the
sublime belief, that all physical phenomena could be contemplated
by asufficiently high intelligence as consequences of one harmo-
nious system of intelligible laws, ordained by the Author and Up-
holder of the universe; perhaps as the manifold results of one such
mathematical law.

But if those profound and abstract works, in which so large a part
is occupied by purely mathematical reasoning, suggest more imme-
diately the thought of that great intellectual consummation, we must
not therefore overlook the claims of experimental and practical inqui-
rers, nor forget that they also have an important office to perform in
the progress of human knowledge; and that the materials must be
supplied by them, though others may arrange and refine them. Es-
pecially does it become important to call in the aid of experimental
research, when facts of a primary and (so to speak) a central charac-
ter require to be established ; above all, if the establishment of such
facts has been attempted in vain, or with only doubtful success, by

278

eminent experimentalists already. Now, in the theory of heat, the
research of the specific heats of the gases is one not far removed from
such primary or central position, being no mere question of detail,
but intimately connected with the inquiry into the nature of heat
itself; it is also one which has been agitated by eminent men, and
results have been obtained by some, and disputed by others, of which
it is interesting, in a high degree, to examine the correctness or in-
validity. For a new examination of this kind, conducted by. new
methods of experiment, the present award has been made. Of the
nature and grounds of this award, I now proceed briefly to speak ;
and first, it may be proper that I should remind the Academy of the
meaning of this phrase specific heats, and of the phenomena which
suggest the name and the conception.

When any two equal volumes of water at any two unequal tempera-
tures are mixed together, the mixture acquires, in general, a tempera-
ture whichiseither exactly or atleast very nearly intermediate between
the two original temperatures, being as many degrees of the thermo-
meter below the one, as it is higher than the other. Bat if a pint
of mercury at 60° and a pint of water at 80° be brought in contact
and acquire thereby a common temperature, it is found that this last
is not so low as 70°; and that thus, this passage of heat, from the
warmer water to the colder mercury, has cooled the former less than
it has warmed the latter,- as indicated by the degrees of a thermo-
meter. Phenomena of this kind suggest the conception, that only a
part of the heat contained at any one time, in any particular body,
affects the senses or the thermometer ; and that the remainder of the
heat is insensible, latent, or hidden: so that water, for example,
absorbs or hides more heat than the same bulk of mercury at any
temperature common to both, and that for any given increase of
that temperature (measured by the thermometer) the former absorbs
or renders latent more than the latter, while, on the contrary, in
cooling through any given number of degrees, it sets a greater quan-
tity free. Many other phenomena are made intelligible by such
a conception, and even more immediately suggest it. Thus, if we put
a pound of freshly frozen ice in contact with a pound of water, which
is warmer than it by about 140° of Fahrenheit’s thermometer, the
result will be two pounds of water, not at an intermediate, but at the

279

lower temperature ; the excess of heat of the originally warmer water
having been all employed in the mere act of melting the ice, or having
all become insensible or latent, in the new water formed by melting it.
And the principle that heat is absorbed or rendered latent in the pro-
duction of steam from water, but is given out or set free again when
the former is condensed into the latter, is part of the theory of the
steam-engine. But because this phraseology suggests a view of the
intimate nature of heat, which is at most hypothetical only, it has
by many persons been thought better to use the word specific, in-
stead of latent; and to speak of the specific heats of bodies in a sense
analogous to that in which we speak of their specific gravities, to ex-
press only certain known and measurable properties of these bodies,
in relation to the unknown principle of heat. And thus we say, that
water has a greater specific heat than mercury, implying only that,
whatever be the reason, any given bulk or weight of water produces
a more powerful heating effect than is produced by the same bulk
or weight of mercury, when both are cooled through the same number
of degrees, by contact with a body of a lower temperature.

The specific heats of solids and of liquids are comparatively. easy
of determination; but the great rarity or lightness of the gases
renders the measure of their specific heats more difficult. The
former may be investigated with much accuracy, by the aid of
Laplace’s calorimeter: which is an instrument for measuring (by
weight) the quantity of ice that is melted by the heat produced or
set free in the cooling of a given weight of the proposed solid or
liquid body through a given range of temperature. But in applying
the same method to the latter question, that is to the inquiry into
the heats of the gases, it appears to be difficult to disentangle the
small effect of this sort produced by the cooling of any moderate
bulk of gas from the effect produced by the cooling of the envelope
in which that gas is contained. Several other methods also of inquiry
into this delicate subject, however ingeniously devised and carefully
executed, by men of deservedly high reputation, have been consi-
dered liable to the same or to other objections, and have failed
to inspire any general confidence in their results. It seems, how-
ever, that the problem has been at length, to agreat extent, resolved,
by the employment of that other method, which was invented a

280

few years ago by Dr. Apjohn here, and elsewhere by Dr. Suerman ;*
and which may be said to consist in determining, (indirectly, ) through
the help of a thermometer with moistened bulb, the weight of gas
which is required for the conversion (at a known temperature and
under a known pressure) of a known weight of water into vapour,
by cooling through a number of degrees which is known from obser-
vation of another thermometer.

The general theory of the evaporation hygrometer, or the manner
of employing a thermometer with moistened bulb, to discover the
amount of moisture which is contained at any given time in the
atmosphere, was very well and clearly set forth by Mr. (now Sir
James) Ivory, in Tilloch’s Philosophical Magazine for August, 1822,
The same theory was also discovered by M. August of Berlin, with the
date of whose work upon the subject I am unacquainted, having only
seen the extracts made from it in M. Kupffer’s Meteorological and
Magnetical Observations, (published at St. Petersburgh in 1837,) and
in a recent volume of M. Quetelet’s Correspondence. It appears,
indeed, that M. Gay Lussac had prepared the way for this discovery,
by his researches on the cold of evaporation ; and the laws of the
elastic force of vapour, and of its mixture with the gases, without
which the theory could not have been constructed, are due to the
venerable Dalton. Notwithstanding all that had thus been done, the
subject seems to have attracted little general notice in these coun-
tries, until it was recommended to the attention of scientific men at
the first meeting of the British Association ; and Dr. Apjohn, who
was thus led to examine it anew,f was not aware of the results that
had been already obtained. He thus arrived at a new and indepen-
dent solution, of which he had the satisfaction of testing the correct-
ness, by several different series of experiments; and this success
encouraged him to extend the research, and to apply the same prin-
ciples and methods to other gases, and not to atmospheric air alone.

* Dissertatio Physica Inauguralis de Calore Fluidorum Elasticorum Specifico ;
auctore A. C.G. Suerman: Trajectiad Rhenum, 1836. An excellent work, to which
every student of this subject must refer.

+ It appears that another Member of the Academy, Dr. Henry Hudson, was also
led, by this recommendation, to consider this interesting subject.

281

He perceived that whatever the gas* might be, in a current of which
was placed the thermometer with moistened bulb, the minimum or
stationary temperature of that thermometer must be attained when
just enough of heat was given out in cooling, by each new por-
tion of gas, to cause the evaporation of that new portion of mois-
ture with which this gas was at the same time saturated; and that
thus the amount of depression would vary inversely as the spe-
cific heat of the gas, all other circumstances being the same. He in-
vestigated, however, the allowances that should be made for varia-
tions in such other circumstances, and took all other precautions
which his experience pointed out to be important. The consequence
has been a new determination of the specific heats of several different
gases, on which it seems that much reliance may be placed, from the
nature of the method, and from the agreement of the partial results
with each other, and with those of Dr. Suerman, though some of
these results differ widely from those obtained by methods previously
employed ; the specific heat of hydrogen, for instance, being found by
Apjohn and Suerman, to be, under equal volumes, greater than that
of atmospheric air in the ratio nearly of seven to five ; whereas some
former experimenters had supposed it to be equal or inferior. And by
such results the law which had been thought to be obtained by a former
eminent observer, namely, that all the simple gases have, under equal
volumes, the same specific heat, appears to be overthrown. It is im-
possible not to feel some degree of regret, when we are thus compelled
toabandon a view which hadrecommended itself by its simplicity, and
had been found to be in at least partial accordance with facts; but
besides that the search after truth is the primary duty of science, the
whole tenor of scientific history asssures us, that each new seeming
complexity, or apparent anomaly, which the study of nature presents,
is adapted ultimately to lead to the discovery of some new and
higher simplicity.

A somewhat more distinct conception than the foregoing remarks

* Dr. Suerman states, that M. Gay Lussac perceived that the specific heat of
any gas must be connected with the degree of cold produced by the evaporation of
a liquid placed therein; but the remark appears to have been merely made in pas-

sing, and to have been afterwards neglected and forgotten,

282

may have given, of the nature of Dr. Apjohn’s method, may be at-
tained by a short study of that first experiment described by him, in
which it was found that in a stream of dry hydrogen gas, in which a
thermometer with a dry bulb stood at 68°, the one that had the mois-
tened bulb was cooled to 48° of Fahrenheit; the barometer indi-
cating at the same time an atmospheric pressure of 30.114 inches.
From the stationary state to which the second of these two ther-
mometers had been reduced, it is clear that the continual supply of
heat, required for the continuing evaporation of moisture from the
bulb, was supplied neither from the water with which that bulb was
moistened, nor from the mercury which it contained, but only from
the stream of warmer gas which continued to pass along it; the small
effect of radiation from surrounding bodies being neglected in com-
parison herewith. Each new portion of the current of hydrogen, in
cooling from 68° to 48°, must therefore have given out very nearly
the precise amount of heat absorbed by that new portion of moisture,
which passed at the same time from the state of water fo the state of
vapour, at the temperature of 48°. It is also assumed, apparently
upon good grounds, that after the moist bulb attains its stationary
temperature, the whole (or almost the whole) of the new gas, in be-
coming fully cooled, becomes at the same time fully moistened, or
saturated with the new vapour; this vapour being intimately mixed
with the gas which had assisted to form it; and every cubic inch of
this mixture containing exactly (or almost exactly) as much moisture
as a cubic inch could contain, in the form of vapour, at its own tem-
perature: a quantity which is known from the results of Dalton, re-
specting the elastic force of vapour. From those results it follows,
that in the present case, the temperature of the vapour being 48°, its
elastic force must have been such that it could by itself have sup-
ported the pressure of a column of mercury, 35 hundredths of -an
inch in height ; but the pressure upon the mixture was equivalent to
a column 30 inches and 11 hundredths high; therefore the pressure
which could have been supported by the hydrogen alone, at the same
temperature of 48°, was equivalent to 29 inches and 76 hundredths:
so that, by the known proportionality between density and pressure,
the weight of the gas which was contained in the whole or in any part
of this mixture would have exceeded the weight of the vapour in the

283

ratio of 2976 to 35, or in the ratio nearly of 85 to 1, if the weight of
a cubic inch of hydrogen gas were as great as that of watery vapour,
under a common pressure, and at acommon temperature. But under
such circumstances, a cubic inch of vapour weighs about nine times as
much as a cubic inch of hydrogen; we must therefore divide the
number 85 by 9, and we find that in the present case the mixture con-
tained only about 924 grains of hydrogen for every grain of vapour ;
and thus we learn, from this experiment, that the heat required for
the evaporation of a grain of water at the temperature of 48° might
be (and was in fact) supplied by the cooling of about 94 grains of
hydrogen from 68° to 48°. But in order to produce the same
amount of evaporation by the heat which water would give out, in
cooling through the same range of temperature, it is known from
other experiments that it would be necessary to employ about 56
grains; therefore 94 grains of hydrogen have nearly as much heating
power as 56 grains of water, or one grain of the former contains
almost as much specific heat as six grains of the latter. All this is
stated in round numbers, and with the omission of all lesser correc-
tions, for the sake merely of such members as may not have attended
to the subject, and yet may wish to have a clear, though general no-
tion of it. Those who desire a more exact account will, of course,
turn to the Essay itself.*

With respect to those independent, but analogous researches of

* The formula given by Dr. Apjohn for the general solution of the problem of the

moist bulb hygrometer, in any gaseous atmosphere, is,

pnmie eed yy:

e 30

in which e is the caloric of elasticity of vapour, at the temperature ¢’ of the hygro-
meter; p is the atmospheric pressure ; d is the difference between the tempera-
tures of the dry and wet thermometers: f’ and f” are the elastic forces of the vapour
of water, at the temperature of the hygrometer, and at that other temperature at
which dew would begin to be deposited ; and ais the specific heat of the gas, com-
pared with that of an equal weight of water, and multiplied by the specific gravity
of the same gas, compared with that of atmospheric air. For the case of a current

of dry gas f’ = 0, and

484° p
in which, as also in the other formula, it would be a little more exact to write
p-—f’ instead of p. A correction is given for the case of a mixture of gas with air ; and
the influence of other corrections also is taken into account. Whena is divided by

284

Dr. Suerman,* to which allusion has been made, they seem (as has
been said) to confirm as closely as could be expected, under the differing
circumstances of the experiments, the results of Dr. Apjohn ; of whose
labours, indeed, that eminent foreigner has spoken in the most hand-
some terms, and in favour of whom he has freely waived, upon this
subject, all contest for priority. But even if among the many per-
sons who now are cultivating science in many distant countries, and
whose results are sometimes long in coming to the knowledge of
each other, it should be found that some one has anticipated our
countryman and brother academician in the publication or invention
of the method which I have endeavoured briefly to describe to you, or
if, on the other hand, his own future reflections and experiments, or
those of any other person, shall indicate hereafter the necessity of any
new improvement, your Council still will have no cause to regret that
they have adjudged the present distinction té&a paper which contains
so much of independent thought, and so much of positive merit.

[The President then delivered the Medal to Doctor Apjohn,
addressing him as follows.]

Doctor Apjohn,

In the name of the Royal Irish Academy, I present to you this
Medal, for your investigations respecting the specific heats of the
gases; hoping that it will be received and valued by you, as attesting
our sense of the services which you have already rendered to that
important and delicate department of physical research ; and that it
will also be to you a stimulus and an encouragement to pursue the
same inquiry further’ still, so as to improve still more the results al-
ready obtained, and to establish other new ones ; and thus to connect,
more and more closely, your name and our Transactions with the
history of-this part of Science.

the known number 0,267 the quotient is the specific heat of the gas compared with
that of an equal volume of atmospheric air: and the sensible inequality of the
specific heats so found, for different simple gases, is the chief physical conclusion
of the paper. ;

* Itis proper to remember that Dr. Suerman published his Dissertation without
having seen the last and most correct results of Dr. Apjohn, contained in the

present prize Essay. This remark applies particularly to the specific heat of
hydrogen.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1839. No. 16.

March 16. (Stated Meeting.)
SIR Wa. R. HAMILTON, A. M., President, in the Chair.

This being the day appointed by Charter for the annual
election, the following Officers and Members of Council were
chosen for the ensuing year :

President—Professor Sir Wm. Rowan Hamilton, A. M.

Treasurer—Thomas Herbert Orpen, M. D.

Secretary—Joseph Henderson Singer, D. D.

Secretary to Council—Rey. Humphrey Lloyd, A.M.

Secretary of Foreign Correspondence—Sir Wm. Betham.

Librarian—Reyv. William Hamilton Drummond, D. D.

Commitiee of Science.

Rev. Franc Sadleir, D. D. Provost of Trinity College ;
Rev. Humphrey Lloyd, A.M.; James Apjohn, M.D. ; James
Mac Cullagh, LL.D.; William Stokes, M. D.; Rev. William
Digby Sadleir, A. M.; Robert Ball, Esq.

Committee of Polite Literature.

His Grace the Archbishop of Dublin; Rev. Joseph H.
Singer, D. D.; Samuel Litton, M. D.; Rev. William H.
Drummond, D. D.; Rev. Charles Richard Elrington, D. D. ;
Rev. Charles William Wall, D. D.; Rev. Thomas H.
Porter, D.D.

2B

286

Committee of Antiquities.

Thomas Herbert Orpen, M. D:; Sir William Betham ;
George Petrie, Esq. ; Rev. Caesar Otway, A. B. ; the Very
Rey. the Dean of St. Patrick’s; Rev. James Henthorn Todd,
B. D. ; Henry J. Monck Mason, LL.D.

The President under his hand and seal appointed the
following Vice-Presidents :

His Grace the Archbishop of Dublin; the Provost ;
Samuel Litton, M, D.; Rev. Humphrey Lloyd, A. M.

The Committee appointed to examine the Treasurer’s
Accounts reported as follows :

** We have examined the above Account,* with the
vouchers produced, and have found it to be correct ; and we
find that there is a balance in bank of £160 ; and in the
Treasurer’s hands £112 6s. 10d., making a total balance of
£272 6s. 10d. sterling.

** (Signed,)
** FRANC SADLEIR,
** Samuey Litton.”
** March 9th, 1839.”

“The Treasurer reports that there are the following
portions of Stock in the Bank of Ireland to the credit of the
Academy :

** £1500 in 3 per Cent. Consols.

** £1500 in 33 per Cent. Government Stock, being the
Cunningham Fund.

** (Signed,)
** FRANC SADLEIR,
* Samuet Lirron.”
“ Dec. 31st, 1838.”

* Entered in the Treasurer’s Book.

287

Dr. Apjohn read a paper on the Analysis of the Water
of the Dead Sea.

After some general remarks upon the geographical posi-
tion, extent, and depth of the Dead Sea, the geological
structure of the surrounding country, and the different
statements handed down by the older historians, and to a
certain extent corroborated by modern travellers, in refe-
rence to the excessive density of its waters, and the absence
from them of living things, both animal and vegetable, Dr. Ap- +
john gave ahistorical sketch of the analytical researches, in
reference to this water, of Lavoisier, Marcet, and Klaproth.

The specimen which he examined, he stated to have been
recently brought to this country by George James Knox,
Esq., from Syria, and to have been committed to him for
analysis by the Rev. Thomas Knox, both members of the
Academy, and authors of valuable scientific communica-
tions, read at our meetings, or published in our Transactions.
A number of experiments were now detailed, having for
their object to determine the nature of the saline consti-
tuents of the water, and illustrate its composition and pro-
perties. Its specific gravity was set down as 1153, and its
boiling point as 221°. Its contained salts were enumerated
as sulphate of lime, chloride of calcium, chloride of magne-
sium, bromide of magnesium, chloride of potassium, chloride
of sodium, chloride of manganese, and sulphate of lime; the
chloride of potassium and manganese, and the bromide of
magnesium having, as he thought, up to the time of the
completion of his analysis, been first detected by himself.
It held in solution an unusually small amount of air.

The following is an outline of the method of analysis
employed.

To approximate to the quantity of saline matter, a
known weight of the water was evaporated to dryness, and
finally heated to about 400°. The residuum amounted to

18.91 per cent.
2B2

288

During the evaporation, a portion of the chloride of
magnesium was decomposed, and water being poured on, the
amount of magnesia left undissolved was determined.

To the solution, oxalate of ammonia was added in
excess, by which the lime was obtained ; and, this being
separated, the remainder of the magnesia was insulated in
the usual manner, by boiling with carbonate of potash, eva-
porating to dryness, &c.

To check the determination of the magnesia, the follow-
ing method was taken. A known weight of the water was
boiled with excess of lime, by which the magnesium and
manganese were separated and replaced by calcium. The
amount of this latter metal (the free lime being, of course,
first removed by carbonic acid, boiling, &c.) was then deter-
mined by oxalate of ammonia, and subtracting from it the
calcium of the water as previously determined, the remainder
was the calcium which replaced the magnesium and man-
ganese. This remainder (the manganese being present in
very minute proportion) was found to be almost exactly what
it should be, supposing it to replace nothing but magnesium,
or it was to the magnesium directly determined in the ratio
of the atomic weights of the two metals.

The solution, deprived of magnesia, lime, and manga-
nese, was now evaporated to dryness, and ignited so as to
expel the ammoniacal salts, and the residue gave the mixed
chlorides of potassium and sodium, with a trace of sulphate
of potash. The quantity of chloride of potassium in this
mixture was determined in the usual way, by the bichloride
of platinum, and the difference gave the chloride of sodium.
The numbers thus obtained, some spattering having occurred
during the expulsion of the ammoniacal salts, were looked
upon as only relatively true, and were corrected in the fol-
lowing manner.

The chlorine and bromine having being determined, as
shall be presently described, as also the different metals,

289

with the exception of the alkaline ones, and the bromine
being supposed united with magnesium, and a deduction
made from the calcium for the small amount of sulphate of
lime present, it was easy, by giving to the manganese and
earthy metals their proper proportions of chlorine, to infer
the quantity of this principle united with the potassium and
sodium. Let this quantity, which was found greater than
what resulted from the direct determination of the chlorides
of these metals, be called w, and let m be to min the ratio of
the chloride of potassium to the chloride of sodium, as
already determined. Let x, also, be the true weight of the
chloride of potassium, y the true weight of the chloride of
sodium, a the ratio of the atomic weight of chloride of potas-
sium to chlorine, and 4 that of chloride of sodium to chlorine.
We will thus obviously have the two following equations :
an+by=w; and, nv = my;

from which we readily deduce

mw nw
ma + nb ° A ag ST

From a fresh portion of the water the sulphuric acid was
got by nitrate of barytes, and the sulphate of barytes having
been separated, the chlorine and bromine were thrown down
in union with silver.* To infer, however, from this mixed
precipitate, the chlorine, it was necessary to estimate the
bromine present by a distinct process.

t=

With this view, a strong aqueous solution of chlorine
was mixed with a known weight of the water under analysis,
and the bromine liberated was removed by repeated wash-
ings with ether. From the etherial solution, the bromine mixed
with some chlorine was separated by barytic water, and the
ether being distilled off, the residue was evaporated to dry-
ness, and ignited, so as to reduce any bromate and chlorate

* The excess of silver having been separated from the solution, by chloride of
sodium, the manganese was thrown down by the addition of hydrosulphate of ammo-

nia. This metal was also estimated by the process recommended by Stromeyer.

290

of barytes formed to bromide and chloride of barium.
These salts were dissolved in water, deprived by carbonic
acid and boiling of free barytes; again evaporated to dryness,
ignited, and accurately weighed. Water being poured on,
they were re-dissolved, and converted, by the addition of
nitrate of silver, into a mixture of the bromide and chloride
of silver, which was also accurately weighed. Now, if w be
the weight of the mixed bromide and chloride of barium, w’
that of the mixed bromide and chloride of silver, x the chlo-
rine, y the bromine, m the ratio of the atomic weight of chlo-
ride of barium to chlorine, x that of the atomic weight of
bromide of barium to bromine, m’ the ratio of the atomic
weight of chloride of silver to chlorine, and x’ that of the
atomic weight of bromide of silver to bromine, we will have
the following equations :
mx+ny—w, andm«+rnyrw,

from which we get

, ’
_ mw —_—mw *

~ mn’ — m'n’

Having thus obtained the bromine, the chloride was easily
inferred from the mixed chloride and bromide of silver, al-
ready got by adding nitrate of silver to the water. The
following are the final results.

Chloride of calcium, 2.438)
Chloride of magnesium, 7.370 |
Bromide of magnesium, 0.201

Chloride of potassium, 0.852+= 18.78.

Chloride of sodium, 7.839
Chloride ofmanganese, 0.005
Sulphate of lime, 0.075
Water, 81.220
100.

* This method answers well, the atomic weight of bromine being so much
greater than that of chlorine, and is susceptible of far greater accuracy than any
more direct one, having for its object the insulation of the bromine.

291

When the analysis was completed, with the exception of
the quantitative determination of the bromine, Dr. Apjohn
became aware that in the discovery in the water of the Dead
Sea of the potassium, manganese, and bromine, he had
been anticipated by M. C.G. Gmelin, who has assigned to
it the following composition.

Specific gravity = 1212,

Chloride of calcium, 8.2141)

Chloride of magnesium, 11.7734

Bromide of magnesium, 0.4393 |
Chloride of potassium 1.6738
Chloride of sodium 7.0777 \— 94,5398.
Chloride of manganese 0.2117

Chloride of ammonium, 0.0896

Chloride ofaluminum, 0.0075

Sulphate of lime, 0.05273
Water, 75.4602
100.

After having seen this analysis, Dr. Apjohn stated, that he
again looked for alumina and ammonia, but could not detect
the slightest trace. of either. The quantities, however, of
these principles found by Gmelin were so small, that their
non-appearance in Dr. Apjohn’s analysis cannot be consi-
dered as amaterial discrepancy. But there are other striking
differences.

The density of the specimen examined by Gmelin, and
its percentage of saline matter were considerably higher than
those which belonged to the water analyzed by Dr. Apjohn,
a circumstance easily accounted for, by the fact ofthe latter
having been collected about half a mile from the embou-
chure of the Jordan, and towards the close of the rainy
season. But notwithstanding this, it might have been an-
ticipated, that the results of both for the different salts
should be relatively the same; such, however, is far from

292

being the case. The ratio of the chloride of magnesium to
the chloride of calcium is much greater, and of the chloride
of sodium to the chloride of potassium, much smaller with
Gmelin than with Dr. Apjohn. The quantities also of the
bromide of magnesium and chloride of manganese, as deter-
mined by Gmelin, are, asrespects Dr. Apjohn’s numbers, dis-
proportionately great, and, what is very singular, the amount
ofthe chloride of sodium obtained by Gmelin is absolutely less
than that got by Dr. Apjohn, though the total amount of
saline matter in the water examined by the former, is to that
in the specimen examined by the latter, very nearly in the
ratio of 4 to 3.

It is not easy to explain such discrepancies, but assuming
both analyses as correct, we arrive at the conclusion, that the
waters of the lake in question are subject to a variation of
constitution, affecting not only the relation of the saline
matter to the water, but the proportions also which the
different salts bear to each other.

Mr. Bergin exhibited to the Academy, the results of
some experiments with photogenic paper, prepared after the
method of Mr. Talbot.

Resotvep,—That the Academy do condole with the family
of Dr. Perceval, one of the original Members of the Aca-
demy, and its first Secretary; and that the Secretary be
requested to draw up the expression of its condolence.

ResotveD,—That the thanks of the Academy be given to
the Marquis of Normanby for the manuscript of the late
General Vallancey, presented by him to the Academy;
and that the President be requested to communicate the
same.

293

DONATIONS.

Manuscript Volume of the late General Vallancey. Pre-
sented by the Marquis of Normanby.

The Rights of Animals. By the Rev. W. H. Drummond.
Presented by the Author.

Astronomical Observations made at the Cambridge Obser-
vatory, by the Rev. James Challis, M. A. Presented by the
Author.

Tables of Logarithms. Presented by the publishers,
Messrs. Taylor and Walton of London.

Political Medicine. By T. H. Maunsell, M.D. Pre-
sented by the Author. ;

Comptes Rendus Hebdomadaires des Seances de l’ Acade-
mie des Sciences. Par MM. les Secretaires Perpetuels.
Nos. 2—7. Premier Semestre, 1839. Presented by the
Academy.

April 8.
SIR Wm. R. HAMILTON, A. M., President, in the Chair.

Thomas Rhodes, Esq., and John U. Owen, M. D., were
elected Members of the Academy.

Professor Lloyd laid on the table of the Academy, the
apparatus for experiments on the rectilinear, elliptic, and cir-
cular polarization of light, invented by M. Dove of Berlin ;
also two sets of Fraunhofer’s gratings, presented to him by
Edward Cooper, Esq. M.P., by whom they were brought
from Munich.

Dr. Wilde, a visiter, by permission of the Academy, read
a paper on some Discoveries he had made at Tyre, relating
to the manufacture of the celebrated Purple Dye.

294

Dr. Wilde stated, that having been engaged in investi-
gating the ruins of Tyre, he discovered several circular
apertures or reservoirs cut inthe solid sandstone rock close to
the water’s edge along the southern shores ofthe peninsula.
These in shape resembled a large pot, and varied in size
from two to eight feet, in diameter and from four to five deep ;
some were in clusters, others isolated, and several were con-
nected in pairs by a conduit about afoot deep. Many of
those reservoirs were filled with a breccia solely compos-
sed of broken up shells, bound together by carbonate of
lime, and a small trace of strontian; large heaps of a simi-
lar breccia were found in the vicinity of the pots. This
mass, a portion of which Dr. Wilde exhibited to the Aca-
demy, is exceedingly heavy, of adamantine hardness, and
the shells of which it is composed appear to be all of one spe-
cies, and from the sharpness of their fracture, were evidently
broken by art and not worn or water washed. ‘The portions
of shell were examined by eminent naturalists, and are pro-
nounced to be the murex trunculus, which most concholo-
gists agree was one species from which the Tyrian dye was
obtained, but until now, no proof could be given of its being
the actual shell.

Dr. Wilde is of opinion, that the reservoirs he discover-
ed were the vats or mortars in which the shells were broken
up, in order to obtain the dye (which lies in a sac in the neck
of the mollusc inhabiting them,) and showed that it accu-
rately accords with the description of Pliny, who states, that
the smaller shells (of which those in the specimen are ex-
amples) were broken in “ certain mills.”

Dr. Wilde exhibited some ancient spear heads, the pro-
perty of Lord Lorton, found in the County of Roscommon.

RESOLVED, (on the recommendation of Council,)—That
certain defaulters, owing five years’ subscription and upwards

295

on the 16th of March last, be declared to be no longer
Members of the Academy.

ResoLveD,—That the new device, proposed by Sir W.
Betham for the Seal of the Academy, be adopted, and that
the thanks of the Academy be given to Sir W. Betham.

DONATIONS.

Comptes Rendus Hebdomadaires des Séances de l Acadé-
mie des Sciences. Nos. 8—9, 1839. Presented by the Aca-
demy.

Abhandlungen der Koniglichen Academie der Wissens-
chaften zu Berlin, for 1833. Also, Uber die Landerverwal-
tung unter dem Chalifate, von Joseph von Hammer, 1835.
Presented by the Royal Academy of Berlin.

Statistique de la France 1835. (Commerce Exterieur.)
Presented by Mons. Moreau de Jonnes.

Dr. Walsh's Constantinople. Presented by the Author.

Walsh on-early Christian Coins and Gems. Presented
by the Author. ,

Dr. Walsh’s Journey from Constantinople. Presented
by the Author.

First Annual Report of the Dublin Natural History
Society, 1839. Presented by the Society. m

Catalogue of the Library of the Royal Dublin Society,
1839. Presented by the Society.

Transactions of the Geological Society of London. Vol.
V. Part I. Presented by the Society.

Report on the Geology of Cornwall, Devon, and West
Somerset ; by Henry T. de la Beche, F. R. S. Presented
by the Lords Commissioners of the Treasury.

296

April 22nd, 1839.
SIR Wo. R. HAMILTON, A. M., President, in the Chair.

The Rev. Dr. Walsh read a paper on a Sepulchral Urn
and Stone Coffin found in the Parish of Kilbride, with some
notices of the Parish.

The union of Kilbride, county of Wicklow, consists of
four parishes, forming a triangular area of fifteen miles in
circumference, bounded by the River Ovoca, the sea coast,
and a line drawn from one to the other. The Irish language
is entirely extinct among the peasantry, and though the names
of places and particular objects are very expressive in that
language, they are altogether unintelligible to the people. Not
an individual among them can speak a word of their native

‘tongue. The majority are of the reformed religion, English
colonists located in this maritime district, after the wars of
Elizabeth, Cromwell, and James. They preserve many tradi-
tions of their achievements; one family kept a sword taken
from the last tory seen in the county, whom they killed. It
had six pounds of brass in the hilt, obtained perhaps from the

. copper mines of Cronebane, long before they were regularly ~

worked. The people are serious and religious, and dis-
tinguished for their moral qualities, dishonesty is unknown

among them, and their sobriety is such, that there is not a

public house in the union of fifteen miles in extent, nor

did Dr. Walsh remember to have ever seen in the parish a
drunken man on Sunday.

The land is divided by a ridge of hills rising through the
centre, dividing it into the Vale of Ovoca and the Vale of
Redcross. This ridge affords many lovely prospects from its.
summit. One was compared by Dr. Pococke to the view he
had seen of the Vale of Nazareth, from the ridges of —
Mount Lebanon. The sea shore isa level strand, lined with

297

sand hills, thrown up from the sand constantly dropped
from the great submerged banks which lie along the Wick-
low coast. Those near the mouth of the Ovoca are dis-
tinguished for their fertilizing property. They were found
to contain immense quantities of human bones in a state of
decomposition. Many battles are recorded as fought in this
place, and the hills here seem tumuli raised over the bodies
of the slain.

In other places the sand banks are covered with a rich
sward, which seems to rest upon a soil as firm as any other
land. It-was suggested by a gentleman, to employ the pea-
santry of the neighbourhood in- weaving the sedge, and
other marine plants, into mats and baskets. When they
were cut away for this purpose, the hills, losing the tenacity
they afforded, began to move, and have continued to do so,
changing the whole face of the country, covering up farms
and houses, and converting the townland, like Bannow, into
another Irish Herculaneum.

The ridge of the hill affords many remains of remote an-
tiquity, some are blocks: of stone fifteen feet in length, laid
parallel to each other, resembling burying places made for
men of gigantic stature. Beside one of these, a curious dis-
covery was recently made. A farmer was raising stones ina
wild and solitary part of the mountain, to fill up gaps ; about
two feet below the surface, he turned up a flag, under which
was a stone coffin, containing an urn in an inverted position,
under which were two small bones laid parallel to each other.
The coffin, consisting of six flags, was eighteen inches long,
the sides seven inches high, and ten broad, put together with
neatness, the corners rectangular, and the sides perpendicu-
lar ; the inside perfectly clean, and free from dust or mould.
The urn was four inches deep, swelling in the middle, and
contracting at both ends. It was rudely but neatly sculptured
with great care; the bones were very small, but perfect,
having articulations at both ends, and were pronounced to be

298

joints of human fingers and toes. The urn was procured by
Dr. Walsh, then incumbent of the parish, and was in high
preservation, but when he endeavoured to move the stone
coffin, it broke into fragments, which he gathered up, and
had a good model of it made in wood, by a country carpen-
ter on the spot.

Dr. Walsh concluded his communication in the following
words. ‘ The mode of sepulture by such urns and stone
coffins is too common to trouble the Academy with details of
them. Many are recorded in their own Transactions; but
I cannot find that an urn in a stone coffin, inverted over two
bones of the human fingers, has before been discovered or
described. I have searched various archeological works, and
can find no such thing. It only remains for me, therefore,
to present to the Academy the urn and model of the coffin,
&c. if they deem them worth their acceptance, and leave it to
some more intelligent and industrious member to pursue the

inquiry.”

In a conversation which arose after the reading of this
paper, the Rev. Caesar Otway gave an account ofa visit
which he made, in company with the Dean of St. Patrick’s,
to the same district ; and related some anecdotes of the
opening of tumuli in other parts of Ireland. Mr. Otway
suggested, that a deputation should be sent from the Aca-
demy to superintend the opening of some ancient cairns, with
a view to obtain a more accurate account of their contents,
than can be expected when they are opened accidentally or
by peasants.

Mr. Petrie made some remarks on the historical interest
of the Cairns in Ireland, most of which are noticed in the
Irish annals, and strongly recommended that Mr. Otway’s
suggestion should be acted on.

299

The Secretary of Council read the following notice of a
Compound of Fluorine and Carbon, by George J. Knox, Esq.;
communicated in a letter to Dr. Apjohn.

“When a current of dry chlorine gas is passed over
- fluoride of silver fused in a platinum tube, the extremity of
which fits into a platinum receiver immersed in a freezing
mixture, the fluoride of silver is decomposed, being converted
into chloride of silver, and no solid or liquid substance is
found in the receiver. When, however, in place of chlorine,
the vapour of liquid chloride of carbon (serrulas) is substi-
tuted, the fluoride of silver is decomposed, and the receiver
is found to contain acicular crystals, which are insoluble in
water, acids, and alkalies, sparingly soluble in alcohol and
ether, but very soluble in spirits of turpentine. When heat-
ed ina platinum crucible, they sublime unaltered, emitting a
strong aromatic odour ; their vapour does notaffect the colour
of litmus paper. When a cold glass plate is placed over the
mouth of the platinum crucible, the crystals subliming con-
dense upon the ‘glass, and acting upon it, engrave upon its
surface a beautiful outline of their form. Ignited in a closed
platinum vessel, they are decomposed, depositing charcoal.

‘* When the vapour of chloride of carbon is passed over
iodide and bromide of silver fused in glass tubes, analogous
compounds are formed ; the one in the form of long needles,
the other of feathery crystals. Both sublime unaltered when
heated ; are insoluble in water, acids, alkalies, alcohol, and
ether ; but soluble in warm spirits of turpentine and chloride
of carbon.

‘*T have failed twice in obtaining a sufficient quantity of
the crystals for analysis, and so send you the paper as it is.
The first time I obtained 20 grs. which would have been
enough, but I lavished it in determining its qualities. I had
intended analyzing it by burning it with deutoxide of cop-
per in a leaden tube, estimating the carbonic acid by the in-
creased weight of potash, and throwing down the fluorine

300

from the dissolved contents of the tube by lime. Is this method
preferable to burning it with silica; conveying the fluosilicic
acid into ammonia, and estimating by the weight of silica 2”

The Secretary read a second notice by the same author,
on a supposed fluoride of nitrogen.

“‘ Having transferred a drop of chloride of nitrogen into
a platinum capsule containing a little water, on adding to the
water an aqueous solution of fluoride of silver, a gas was
freely evolved, somewhat resembling chlorine in smell, but
of so pungent a nature, and so exceedingly irritating to the
eyes, that I was unable to approach near enough to deter-
mine any of its properties, although my eyes were protected
by a mask and spectacles. When the gas had all escaped,
the capsule was found to contain chloride of silver, fluoride
of silver and water, and had not been sensibly heated by the
intense chemical action which had taken place.

** Again, on adding to a portion of dry fluoride of silver
contained in a platinum dish, a drop of chloride of nitrogen,
so violent an explosion took place, that the platinum dish
was torn as if it had been made of parchment, and a consi-
derable part of it blown away.”

Mr. Robert Mallet communicated a notice of the dis-
covery of the property of the light emitted by incandescent
coke to blacken photogenic paper; and proposed it as a
substitute for solar light, or that from the oxy-hydrogen
blowpipe with lime.

One of the most important applications of the photogenic
process, as yet suggested, is its adaptation to the self regis-
tering of long continued instrumental observations. Unless,
however, an artificial light, of a simple and inexpensive cha-
racter, can be found to supply the place of solar light at
night, the utility of this application will be much limited.

Few artificial lights emit enough of the chemical rays to

301

act with certainty on the prepared paper; while those which
are known to ‘act well, as the oxyhydrogen lime light, are
expensive, and difficult to manage. A considerable time
since, the author discovered that the light emitted by incan-
descent coke, at the ‘‘'Twyer” (or aperture by which the
blast is admitted) ofa cupola or furnace for melting cast iron,
‘contained the chemical rays in abundance ; and on lately
trying the effect of this light on the prepared paper, he
found it was intensely blackened in about forty-five seconds.
‘In the single experiment made, the heat, which was conside-
rable, was not separated from the light; but the author pur-
posed to make further experiments, in which this precaution
will be attended to.

There is no difficulty to be apprehended in contriving an
apparatus to burn a small quantity of coke at a high tempe-
rature. A diagram of an apparatus for this purpose was
shown. It consists of a vertical tube, nine inches in diameter,
lined with refractory clay, and closed at top and bottom.
There is a grating about one foot from the bottom, a little
above which are two opposite holes, into one of which an air
blast from a revolving fanner is projected through the coke,
with which the whole tube is filled. ‘The flame passes out
at the opposite hole, through a tube so contrived, as to heat
the blast of air to a temperature of 500°, just before it enters
the coke fire.

The light from the former lateral aperture is that pro-
posed to be used, and issues through a plate of mica or
glass opposite to it. This aperture forms part of the con-
ductory tube for the blast, which (by passing into the coke
in a direction opposite to that in which the light is emitted)
keeps the illuminating surface of coke clear from ashes;
these are received below the grating, and by a diversion of
part of the blast, are blown into the chimney which receives
the other products of the combustion.

As the vertical tube is close above, the combustion can-

2c

302

not proceed upwards, while the coke with which it is filled
constantly drops down to supply the place ofthat consumed,
on the principle of the ancient furnaces, called “ athanors”
by the earlier chemists.

The only difficulty to be apprehended in the use of coke,
is the collection of slag, from the fusion of its earthy and
ferruginous constituents; however the author does not con-
sider that this accumulation during the period from sunset to
sunrise, in mid-winter, would materially interfere with its
action.

The Treasurer presented the account for the year ending
March 31, 1839.

OrvzreED to be entered on the minutes, and published in
the Proceedings.

OrperED,—That the Seal of the Academy be affixed to
the Treasurer’s Accounts.

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PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1839. No. 17.

May 13.
SIR Wm. R. HAMILTON, A. M., President, in the Chair.

Edward Conroy, Esq., and Nicholas P. Leader, Ksq.,
were elected Members of the Academy.

Sir James Ivory was elected an Honorary Member of
the Academy.

Dr. Wilde read a paper upon the Peruvian mummy, re-
cently opened in Dublin. He stated that Captain Duniam
a gentleman in the South American trade, having been in-
formed that a colony of Irish had settled on the western
coast some years since, determined on visiting them; and
having been hospitably received, was brought on a day’s
pleasure to a wild spot on the shore, where the party, for
his amusement, commenced digging up several mummies,
the most perfect of which he brought away. In a letter he
says: “ This mummy was dug up from the sloping ground,
about two miles and a-half south-east of the Morro of Arica,
facing to the south-west on the coast of Peru, the soil
sandy, in depth about six inches, under which is a layer of
saltpetre about eight inches thick, and so very hard that it
had to be broken with a pickaxe. Underneath this is a
mixture of saltpetre and sand, out of which the body was
dug. The face was found turned towards the west, or setting

2D

306

sun; and all the utensils, pots, &c. were buried with him,
forming a semicircle in front.”

Tradition reports, that these were the bodies of the an-
cient Peruvians, buried before the invasion of the Spaniards ;
and it is also said, that remains similar to those are found on
the eastern side of the mountains, having their faces turned
to the rising sun, but still in the same sitting posture,

Dr. Wilde then exhibited a drawing by Mr. Wakeman,
showing the state in which the mummy had been received,
and continued: ‘‘ This drawing shows the condition in
which the mummy was found, bound up in a cloak, or
outer garment, fitting so as to give a tolerably accurate
idea of the posture in which it was placed; and over this
was wrought a net of rushes, or other such substance,
with large meshes, in the manner of a purse, wound several
times round the neck and ankles, without covering the head
or feet.”

Dr. Wilde observed, that it was a practice of the ancient
Egyptians to bind their mummies tightly round the neck and
feet, and produced an example in which the diameter of the
neck did not exceed two inches. ‘‘ On cleaning and repair-
ing this outer garment, cloak, or poncho, it was found to be
composed of a complete web of cloth, formed apparently of
the wool of the Lama. In texture it resembles several of
the specimens of the Egyptian linen which I found in the
catacombs at Sakara, the character of which depends upon
the great tightness of the threads of the weft, and looseness
of the warp, arising from the imperfection of the loom, and
use of a ruler instead of a shuttle in weaving—a practice
formerly used in Egypt, (as shown by the plates of Rosel-
lini,)—found still extant in Mexico by Dr. Coulter, and
noticed by myself in Barbary and Judea.”

This garment, which is exceedingly simple in form, con-
sists of a web, doubled and sewn together at the sides, ex-
cept for a short distance at top, where openings were left for

307

the arms. One was also made for the head; but when the
dress was round the mummy no opening could be perceived.
When restored and cleaned, it will serve to illustrate the dress
of the ancient Peruvians, and, with the other utensils found
buried, will furnish data to determine the state of the arts and
condition of this interesting people. These articles consist
of fourteen vessels of burned pottery, of different sizes; pip-
kins, jars with long narrow necks, and globular vessels with
small circular openings—some of remarkably fine workman-
ship, though they do not seem to be made on a wheel—
unglazed, bearing the marks of fire, and probably used as
cooking utensils by the deceased ; remains of a basket of
great beauty, so intricately woven as to be capable of hold-
ing water, and similar to those still in use in the central
parts of Africa; calabashes and rush baskets, interwoven
with coloured worsteds; mats of a similar material, and
most elaborate workmanship; an ancient Mexican pictorial
manuscript or hieroglyphic ; ornamental bags, one contain-
ing the leaves of some vegetable, and a wampum belt. The
variety and brilliancy of the colours are most remarkable ;
mostly all the textures are woollen. A piece of cloth, woven
in stripes of different colours; eight arrows, or bolts; the
model of a painted paddle; a piece of fishing line, cable
laid, showing great art in its construction ; a miniature
stake-net, or fishing trammel, similar to those constructed
for a like purpose in Ireland. These latter articles lead to
the belief that this person was a fisherman.

On the Ist of May the outer garment was removed, in
presence of a number of gentlemen, chiefly members of
the Academy, who had purchased the mummy by sub-
scription. The body was found in a sitting posture—that,
probably, in which the deceased had sat round the coun-
cil fires of his nation. The head is bent forward, ap-
proaching to the knees; the left arm is bent, with the
hand turned in upon the chest; around the fingers is worn

308

a piece of fine fishing-line, and the thumb is turned in on the
hand in a remarkable manner—a custom observed by the
ancient Hebrews, and still adhered to by the religious Jews
of Palestine—namely, to tie the thumb after death into the
cleft, between the fore and middle fingers, lest the extended
thumb should make the chirogram of “ Jehovah,” a name they
feared to write while living, and were unwilling to express
when dead. The hands of Egyptian mummies, which Dr.
Wilde produced, were similarly compressed. The right arm
is concealed under several bags, filled with some substance as
yet unknown; they are large, and similar in construction to
those found outside, but exceeding them in colour. On
these were placed two vessels of highly ornamented pottery.
Vessels of a similar kind are at present used for sipping a
kind of tea with a tube, in the very position this mummy
now presents. The lower parts of the body and hips were
wrapped in folds of striped cloth, which appears to have
been a kilt, a sort of garment worn by the ancient Incas of
Peru. The feet are clad in sandles, fastened on by thongs
of leather. The body was found to be covered with num-
berless minute shining crystals, probably of an animal na-
ture. The head is particularly remarkable from its shape,
and the probable race of mankind to which it belonged.
The hair is divided along the whole length of the head, is
particularly long, and beautifully plaited. Dr. Wilde also
exhibited the head of a young female covered with brown
hair, of great fineness, and likewise beautifully plaited, and
adorned with small golden ornaments attached to the end of
the plaits ; over the face. was tied a mask of skin.

In reference to an observation of Dr. Pettigrew of
London, Dr. Wilde does not think the subject was buried
alive ; and he remarked, that it was in such excellent condi-
tion, and so perfectly dry, as to allow of its being very well
preserved.

Dr. Wilde concluded by mentioning that Mr. Burton

309

had produced two beautiful drawings of the mummy; and
that both Mr. Wakeman and Mr. Burton had presented
their drawings to the subscribers.

The Secretary read a letter from Joseph Lentaigne,
Esq., on the subject of a Manuscript Translation of Part of
Virgil’s Aneid.

“A manuscript, in three volumes, containing the third,
fourth, sixth, eighth, ninth, eleventh, and twelfth books
of the Aineid, in English verse, has been lately placed
in my hands by F. Comyn, Esq., of Woodstock, in the
county of Galway, who discovered it among the books
of one of his ancestors, formerly a physician at the court
of Louis XV. of France. It bears the following date :—
* Ended at St. Germains the 18th day of 7, 1692;”
being two years prior to the commencing of Mr. Dry-
den’s great translation, which (as he informs us) he
was “ three years doing,” and which was completed in
1697. That this manuscript is genuine cannot reason-
ably be doubted. The orthography, the fabric of the
paper upon which it is written, the date of printed papers
used in the binding, and many other circumstances, prove
that it is the production of the period at which it bears
date. The name “ Lauderdail” is written on the fly-leaf,
and is still legible notwithstanding an attempted oblitera-
tion. The author’s name is not given; but the Episode of
Nisus and Euryalus is marked, “ by Mr. Dryden;” that of
Camilla, by “‘ Mr. John Stafford ;” and, at the end, are the
following among other memoranda: — “ Kighty-six errors
since sent to Mr. Dryden, after Bryarly wrote it; 162 errors
corrected since Mr. Bysh wrote this book; 122 errors cor-
rected since Mr. Dallon wrote this book; 486 lines cor-
rected and altered since this book was first sent to Mr.
Dryden.” It is, therefore, most probably the work of se-
veral contributors, but corrected and altered by Lord Lau-

310

derdale, from whom Mr. Dryden acknowledges to have re-
ceived from abroad his lordship’s new translation of Virgil,
two years before he himself engaged in the.same design,
and which he consulted as often as he doubted. of his au-
thor’s sense. This manuscript so nearly resembles the trans-
lation published in 1709, under the name of Lauderdale’s
Virgil, that I am persuaded it is the original of which a
copy was sent to Mr. Dryden, and from which he was ac-
cused, by that nobleman’s friends, of having borrowed not
only single verses, but entire passages. By collating this
manuscript with Mr. Dryden’s version, it is satisfactorily
proved that several verses were so borrowed, with but little
alteration; as thus: AMneid III. 114. “ Ergo agite,” &c.

‘ Let us the land, which fate directs, explore;
Appease the winds, and seek the Cretan shore.
Our way is short; if Jove assists our fleet,
The third day’s dawning lands us safe in Crete.”
MANUSCRIPT.

“ Let us the land, which heav’n appoints, explore ;
Appease the winds, and seek the Gnossian shore.
If Jove assists the passage of our fleet,
The third propitious dawn discovers Crete.”
DRYDEN. -

‘‘Nor are these alterations always in accordance with the
true meaning of the Roman poet. Thus, the lines which
are correctly rendered in the manuscript,

ce ——lIn humble vales they dwelt.
Thence Cybele, the mother of-the gods,
Her tingling cymbals and Idan woods,”

are thus altered by Mr. Dryden :—

‘“‘ In humble vales they built their soft abodes,
Till Cybele, the mother of the gods,
With tingling cymbals charm’d th’ Idzan woods.”
fin. III. 110.

‘* Mr. Stafford’s version of the death of Camilla is the
same as that published under his name in the poetical mis-

dll

cellany, and from it Mr. Dryden has taken six or seven
verses; while the greater part of it has been transferred,
without acknowledgment, into Lauderdale’s Virgil.

“The Episode of Nisus and Euryalus is peculiarly inte-
resting, being from Mr. Dryden’s pen, and varying fre-
quently from the published translation. It contains some
hemistich verses, which the poet, at a later period, con-
demned ; comparing them to “ frogs and serpents in the
Nile, half in life, half mud.”

* T regret that the limits of my paper do not admit of
any extracts from this Episode.”

DONATIONS.

The Silurian System. By R. J. Murchison. In two
Parts. Presented by the Author.

Memoirs of the Royal Astronomical Society. Vol. X.
Presented by the Society.

An Elementary Treatise on the Tides. By J. W. Lub-
bock, Esq. Presented by the Author.

An Inquiry into the Nature of the Numerical Contrac-
tions ; and Notes on Early Calendars. By J. O. Halliwell,
Esq. Presented by the Author.

Transactions of the Cambridge Philosophical Society.
Vol. VI. Part III. Presented by the Society.

Transactions of the Royal Society of London. Parts I.
and II. 1838. Presented by the Society.

Journal of the Franklin Institute, 1838. Presented by
the Institute.

Collectanea de Rebus Albanicis, edited by the Iona Club.
Presented by the Club.

Nouveaux Mémoires de l Académie Royale de Bruxelles.
Années 1837—1838. Tome XI.

Mémoires Couronnes par l Académie Royale de Brucelles.
Tome XIV. Premiere Partie, 1838.

312

Bulletin de UV Académie de Bruxelles. Nos. 9—12.

Annuaire de l Académie de Bruxelles. Cinquieme année.
Presented by the Academy.

Annuaire de 0 Observation de Bruxelles, pour 1839. Par
M. Quetelet.

Resume des Observations Meteorologiques, 1838. Par
M. Quetelet. Presented by the Author.

Comptes Rendus Hebdomadaires des Seances de U Aca-
démie des Sciences. Par MM. les Secretaires Perpetuels.
Nos. 12—17. Premier Semestrie, 1839. Presented by the
Academy.

Eclaircissements sur la destination de trois Zodiaques An-
tiques. Par M. de Briere. Presented by the Author.

The Turkish Empire illustrated. Parts 1—12. Pre-
sented by Dr. Walsh.

Transactions of the Institution of Civil Engineers. Vol.
III. Part I. Presented by the Institution.

May 27, 1839.
SIR Ws. R. HAMILTON, A. M., President, in the Chair.

The thanks of the Academy were- voted to Sir William
Betham for his services as Secretary of Foreign Corres-
pondence ; he having resigned that office, together with his
place in the Council.

Dr. Aquilla Smith was elected to the vacant place in the
Council; and Professor Mac Cullagh was appointed Secre-
tary of Foreign Correspondence.

Dr. Wilde made a second communication on the subject
of the Peruvian Mummy. It appeared that, in accordance
with the wish of the subscribers, a further examination of

313

the mummy had taken place; and the different articles that
had been removed from it and cleaned, were exhibited, as
well as the mummy itself, to the meeting. The pottery-ware
vessels, which were placed underneath the chin, and which
were supposed to have been used for making the infusion of
the yerba de Paraguay, or mattee tea, at present a custom in
that country, are of great beauty in colour, form, and orna-
ment. One of them had the mark of fire on its outer side;
the other, some crystals of salt round its aperture. Two bags
of plain woollen cloth, and sewn up the sides, were found to
contain a quantity of finely ground meal of a brown colour,
still possessing some flavour, and having a saltish taste; and
in one of the bags were also discovered two heads of small
Indian corn, in great preservation. Two other bags of great
beauty of texture, and brilliancy of colour, woven in stripes
of blue and red, contained a quantity of dried leaves sup-
posed to be the cocco, and a small quantity of clay-like
burned substance. Both these bags are of exquisite work-
manship, and bespeak a great perfection of the arts among
this people ; one was adorned with a handsome tassel work
not unlike a lady’s reticule: both were tied at top with a
slip knot. All those substances were no doubt placed to
afford a supply of food for the journey of the deceased to the
land of spirits. ‘The piece of cloth which surrounded all
those, and which was fastened round the neck, was also ex-
hibited, and appeared to be the remains of some old article
of dress belonging to the deceased, from its similarity to the
kilt and apron which surrounded the lower part of the
body. ‘These latter consisted of a broad piece of woollen
cloth of different colours, tied round the loins; and the
apron, which was of different colours, was fastened on the
front of the body by strings which went over the shoulders.
During the examination, a small curious beetle was disco-
vered by Mr. Ball, on which Mr. Curtis, of London, writes,
‘* undoubtedly it is atrue Ptinus of Linneus, althoughit seems
25

314

to be related to mezium sulcatum, figured in the 232nd plate
of my British Insects.” Mr. Curtis states, that Ptint breed
in such situations; and the insect being a perfectly new
species, for which he proposes the name of ptinus mortuorum, .
he thinks it worthy of being described, and offers his ser-
vices for that purpose. The mouth of the mummy was next
examined: the lower lip appears to have been split, pro-
bably after the manner of the natives of Nookta Sound,
spoken of by Captain Cook. The teeth are now exposed to
view ; those of the lower and upper jaw are separated by
some substance placed between. The hair, which has
been cleaned and placed in its proper position, exhibits a
beautiful mode of head adornment ; two large plaits formed
of a number of smaller ones, and tied at the end, hang down
by the side of the face towards either shoulder: it is long,
black, and slightly sprinkled with grey in front. The hair
at back is likewise plaited, having seven plaits on one side, and
eight on the other. The whole is collected in a tie behind,
one lock forming the centre. In the bend of the arm was
found the weight or plummet of a fishing line, (probably that
which was twisted round the fingers of the left hand,) formed
of some metallic substance as yet undecided on. In the
British Museum there is a Peruvian mummy, an enlarged
drawing of which Dr. Wilde exhibited from the work of Dr.
Pettigrew ; in this the hands are extended along the sides of
the face, but the rest of the body is in the position of the
one before the meeting, than which it is much less perfect,
and the head is completely devoid of hair.

Dr. Wilde then read several extracts bearing upon thesub-
ject of Peruvian mummies, and mentioned the name of Mr.
J.R. Pentland, who, in a communication made to Tiedemann,
and translated by Professor Graves, in the Dublin Journal
for July, 1834, gives an account of the ancient graves called
Huxeas, in the Valley of Titicaca; these sepulchres have
the form of high round towers, and in some places are con-

315

structed of enormous masses of masonry, the stones arranged
in a manner similar to the Cyclopean architecture of Greece
and Italy. In all the sepulchres which have been yet dis-
covered, there are remains of food, cooking utensils, and
different articles emblematical of their calling, which was
generally that of fishermen. There is no artificial process
of embalming used, nor were any of the cavities of the body
opened, so that all the interior of this mummy is in a per-
fect state. The nature of the earth, and the peculiar dry-
ness of both it and the atmosphere, are such as to prevent
the putrefactive process; and animals thrown loosely in the
earth are likewise preserved.

The question of the race of mankind to which this mummy
belonged is one of great interest. From the pyramidal form
of the head, and other circumstances, Dr. Wilde conceived it
should be classed among the great Turanian nations, charac-
terized by great breadth of cheek bones,lozenge-shaped faces,
formed by the bases of two triangles meeting on the cheek-
bones, long straight hair, thin scanty beard, olive com-
plexion, confluent features, depth of orbits, eyes wide apart,
and more or less retreating foreheads; peculiarities, several
of which he noticed as exhibited in the head of the mummy,
which he did not think had been altered by artificial pres-
sure, like the head of the modern Peruvian. Humboldt,
Tiedemann, Dr. Pritchard, and Mr. Pentland, agree in giving
this race an Asiatic origin; the last gentleman believing
that the heads were not altered by pressure, and that the
skulls of those ancient Peruvians belonged to a race of
mankind now extinct.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1839. No. 18.

June 10.
SIR Wm. R. HAMILTON, A. M., President, in the Chair.

The following gentlemen were admitted Members of the
Academy: William R. Wilde, Esq., Alexander Parker, Esq.,
and Jonathan Osborne, M. D.

Resotvep,—That the Academy do allow a ballot to take
place at the next Meeting, for W. Longfield, Esq., his name
having been duly proposed within one month before that
night, but too late for the ballot of this evening.

Sir Henry Marsh read a paper “ on Phosphorescence or
” the term phosphorescence being
employed, without implying that the presence of phosphorus |
is necessary to the production of these phenomena.

The chief object of this communication was to bring for-

luminous Appearances ;

ward some interesting facts relative to the evolution of light,
in the living human subject; facts of this nature not having
heretofore been publicly noticed. Indeed so little has this
subject been scientifically investigated, that all such appear-
ances have been referred to supernatural agency, the ulti-
mate and easy refuge of ignorance and superstition.

To render the discussion more complete and intelligible,
Sir H. Marsh introduced the general subject of luminous

2F

318

appearances, as they are observed in the different kingdoms
of nature.

Commencing with unorganized bodies, he particularized
the sun and fixed stars, which are always luminous, but
which derive this property from a source unknown and al-
most beyond conjecture. He then proceeded to the consi-
deration of those bodies, placed under our more immediate
cognizance, which are only occastonally luminous.

The aurora borealis is a beautiful instance of this pro-
perty, clearly ascertained to be of electrical origin, by the
fact that these lights, according to the observations of
Arago and others, disturb the magnetic horizontal needle.
That shooting stars spring from the same source is now uni-
versally conceded.

Some inorganic bodies are rendered luminous, under
various circumstances; the diamond, arragonite, strontia,
marble, calcareous spar, lime, and many other substances
possess this property.

A species of fluor spar, found in the granite rocks of
Siberia, shines in the dark with a remarkable phosphoric
light, which increases when the temperature is raised: by
immersion in boiling mercury it emits such a light that a
book may be read by it at a distance of five inches.

Many bodies may be rendered luminous by friction, by
percussion, or by concussion. Similar effects result from
chemical action and reaction, as in the ordinary process of
combustion. Many salts also, held in solution, exhibit lu-
minous appearances at the time when crystallization is going
forward. And by the agency of electricity many bodies can
be rendered luminous, as proved by transmitting a series of
electric discharges through fragments of chalk, sugar, quartz,
succinic acid. After a few remarks on the important part
which electricity plays in the production of all these effects,
he went on to notice those luminous phenomena so remark-
ably exhibited in organized substances, at the moment of

319

incipient decomposition. Decaying wood, under peculiar
conditions of temperature and humidity, evolves light; and
it is well known that accumulated masses of vegetable mat-
ter, when not sufficiently dried, undergo fermentation, and,
if the process be not interrupted, evolve light and caloric,
and are destroyed by combustion. In recently dead animal
matter the phenomena of phosphorescence is most strikingly
exhibited. Soon after death, fishes become exceedingly lu-
minous. In burial grounds luminous appearances have
often been Seen, and fearful and awful are they to the eye
of superstition. These corpse-lights, as they are called, are
clearly traceable to the same source, and take place during
the earlier stages of disintegration. A very curious, though
not very pleasing appearance of the same kind, and arising
from the same causes, has been observed by many in dis-
secting rooms. The ignis fatuus also is a phenomenon,
which, like those already alluded to, is produced by electri-
city, the result of chemical action in decaying vegetable
matter, when the temperature is in neither extreme, and
humidity sufficient to lend its aid in producing the effect.

Sir H. Marsh then proceeded to the consideration of
phosphorescence, as a function in living vegetables, and de-
scribed the extraordinary and brilliant appearance of phos-
phorescent lichens in the coal mines near Dresden. He
also stated that the flowers of several plants, in serene and
warm summer evenings, disengage light.

It is now known with certainty that light is developed in
living animals, a large proportion of which are inhabitants
of the sea, and from their presence in the water arises the
phosphorescence of the waves, especially in the track of
sailing vessels. The author here enumerated and described
many of the most remarkable marine species of phosphores-
cent animals, and stated that luminous appearances had also
been observed in fresh water animalcula.

He remarked the analogy betweeen luminous and electri-

2F2

320

eal fishes, and proposed the question, whether the vital
property of emitting light was designed for the protection of
these animals, or is it connected with the function of genera-
tion? The property of evolving light is not confined to
aquatic animals; some of the terrestrial mollusca, as the
limax noctilucus, produce a phosphorescent secretion capa-
ble of emitting a light of considerable brilliancy.

Many insects are luminous, as the several species of
elater, the lampyris noctiluca and splendidula, the pausus
spheerocerus, scarabeeus phosphoreus, and the Scolopendra
electrica.

The fulgora lanternaria is one of the most remarkable
of the class, and during the night diffuses so strong a light,
that a few, it is said, being fastened together, are employed
to enlighten the path of the traveller, and to guide his foot
steps during the darkness of night. Having made a few
remarks on the tapetum lucidum existing in the eyes of some
animals, the author proceeded to detail the chief object of
his communication, namely, facts relative to the develop-
ment of light in the living human subject. The first case
that he narrated was that of a young lady in the last stage
of pulmonary consumption. About ten days previously to
her death, there was observed a very extraordinary light
which seemed darting about the face, and illuminating all
around her head, flashing like an aurora borealis: it was
at night, and after a day of extreme nervous agitation pro-
duced by debility and the dread of suffocation. This lumi-
nous appearance commenced suddenly, and was at first
mistaken, by her attendants, for the light of a candle, which
was accordingly removed lest it should disturb the slumbers
of the patient. The peculiar light, however, continued
flitting over her countenance for more than an hour; its hue
was not that of candle light, it was more silvery, like the
reflection of moonlight on water. Three nights afterwards
it re-appeared, and was observed by additional members of

321

her family, at a time when there was no candle in the room,
no moon, nor in fact any visible means of producing light.
The evening before the death of this young lady, the light
was again seen, but it was less brilliant, and lasted only
about twenty minutes.

Phenomena of the same kind were observed around the
person of a man, who died ofa lingering disease, in a remote
part of the south west of Ireland : and a similar case is said
to have been witnessed in Hull.

Sir H. Marsh then related the case of a woman, in the
old Meath Hospital, who laboured under an enormous can-
cerous ulcer of the breast; from the surface and edges of
the sore a quantity of fluid was constantly poured out, which
became so luminous at night, as to be distinctly visible at a
distance of more than twenty feet from her bed.

He suggested a comparison between the condition of a
diseased part emitting light, and that state of the whole
frame which characterizes the disease termed ‘‘ spontaneous

combustion ;”

and mentioned that in one case of spontaneous
combustion, a lambent flame was distinctly seen to issue
from the burning body. A strong analogy doubtless exists
between this state of the living body, and the early state of
decomposition, during which light is emitted.

He then detailed an experiment first performed by
Magendie. Phosphorated oil was injected into the crural
vein of a dog, when immediately its expirations became
luminous, and continued so until the death of the animal.

The author concluded by remarking that the results of
this experiment, and the ascertained presence of phosphorus
in vegetables and animals, would lead to the opinion, that in
some, at least, of the instances of luminous appearances
referred to, phosphorus formed an element in the production
of the effect.

322

W. O’Brien Esq. A.M., read a paper containing an In-
quiry into the original Language of the Phcenicians.

He observes that the explanation given by Bochart and
others of the Punic scene in Plautus, by means of the
Hebrew, is much more natural than that derived from the
Irish by Vallancey, who palmed some words upon that lan-
guage which do not belong to it, and some from the modern
Irish, which are English. He thinks that, even if the ori-
ginal language of the Phcenicians was not the Hebrew, they
must generally have spoken that tongue at the time of the
colonisation of Carthage, since the language of the multitude
must always predominate over that of the few ; and in the
time of Solomon, the Israelites ‘ could not be counted or
numbered for multitude.” Hence he infers that the ancient
language must have been circumscribed within the very nar-
row limits of the few walled cities, and that the greater part
of the adventurers after the first colonisation, must have
spoken the Hebrew language only. Upon these grounds
he concludes, that the Carthaginian language is no more an
indication of the original language of the Phoenicians, than
the English is of that of the ancient Britons or Irish. He
considers, however, that we are not left without another clue
to this language, besides that of the Carthaginians : since,
although languages are obliterated, traces of them remain in
the names of persons, places, rivers, mountains, &c. Thus,
British names survive in England, in spite of the several
conquests by Belge, Romans, Saxons, and Normans: and
although these names are often much corrupted, a philologer
of skill and discretion will be able frequently to see through
the veil, and discover the original word. He shows that this
view exactly corresponds to that taken by the celebrated
Leibnitz, in his work on the origin of nations.

He then proceeds to investigate the roots and meaning of
nearly forty of the names of places and tribes in Palestine.
He professes to admit no derivation, which is barely conjec-

323 |

tural or plausible. One method of confirmation he uses, is,
to trace the assigned roots through several languages and
regions. Thus he traces one of them—zodh-ar, ith-ar—
through vitrum,—«arrirepoc,—margarita—Eridanus—iohar,
(borrowed he says by the Arabians from the Pheenicians)—
Farsidh (Persia), and the names of some of the islands in the
Persian Gulf. He traces zdh-on, iodh-on, the roots of Sidon,
through Chalcedon, Carchedon, Caledonia, and the Germanic
aidstein, whereby he exhibits the meaning of those names
also. He traces the roots of Solyma through the region
inhabited by the Solymi of Homer, the Sulmo of Italy, and
the Saluvii of Gaul, and shows from the accounts concerning
those places, that the roots are equally applicable to them.
The roots of the Hebrew borrowed word glinnim he traces —
through Germany, ancient Britain, Campania, and Liguria.
Another mode of confirmation he uses is the quotation of,
or reference to, various ancient and modern writers, in proof
of the applicability of the terms.

He does not infer from this similarity of language, that
the Irish are descended from a colony of Phoenicians, led—
not from Tyre or Sidon, or any part of Syria, but—from the
shores of the Red Sea, as Irish histories tellus; the greater
part of which histories he imagines to be a tissue of fables,
the rather, as they are at variance with the only authentic
document relating to ancient Ireland, namely, the geography
of Ptolemy. The conclusion he comes to is, that they had a
common origin—that there was an ancient language diffused
over almost the whole of Europe, and a good part of Asia; a
sort of Pelasgic, which is the chief root of the Greek and
Latin, and of most of the modern European languages; and
that this ancient language is preserved in greater purity in
Ireland than in any other country, on account of its insulated
position. He shows that Leibnitz, a man of great sagacity
and philological knowlege, made an observation not very
dissimilar to this. “Tllud autem notatu dignissimum, per

324

magnam continentis nostri partem, linguee cujusdam antique,
latissime fusze, vestigia in linguis hodiernis superesse; cum
multa sint vocabula que inde ab Oceano Britannico ad
usque Japonicum protenduntur.—Itaque lingua Hibernica
refert nobis antiquiores Britannos, et adhuc antiquiores.
Germanos et Gallos. Proinde ex Hibernicé antiquissimi
Celtze in lucem revocabuntur.”—De orig. Gentium. Also,
that a great modern philologer, Adelung, has arrived at
similar results from collating the Parsee, Sanscrit, Greek,
Latin, Sclavonian, and Germanic languages; viz., ‘‘ That
men of the same race peopled all these countries, previously
to any historical record.”

He holds, however, that colonies from Carthage did settle
in Gaul and Britain, though not in Ireland ; that they spoke
the Lybian language only, not the Hebrew ; and that this
language is still in being, though much altered from its origi-
nal, in the languages of Wales, Cornwall, and Bretagne.

It ought to be observed that he claims the settlement,.
incidentally, of some points of great interest to, and much
contested by, antiquarians. 1. The meaning and applica-
tion of the word Caledonia. 2. Of the Greek and Roman
name for Carthage. 3.'The roots and meaning of the Welch
names, Menay and Meneu, words which baffled Lhuyd and
Rowland. 4. The ancient names and uses of Cromlechs.
He holds that their original purpose was that of hearths or
bloomeries for the smelting of metals. That Hedar (of
which he assigns the roots) in Danish Hothr, now Hoath, is
the same word as erath, arath, hearth,—differing from it
only in the transposition of the roots. That chabar is but a
different dialect of the same word, whence the Cabiri, Gue-
bres, derived their name and ceremonies. Also, that the
hearth-stone was deified by the Germans, under the name of
- hertha, not terra mater, as ‘Tacitus says, misinformed by
persons who confounded the Germanic erde and herde, erth
and herth.

325

DONATIONS.

Greenwich Observations, for 1836 and 1837, with Appen-
dix. 4 Vols.

Greenwich Observations. 11 Numbers, from Part V.
1833, to Part V. 1835, inclusive.

Edinburgh Astronomical Observations, for 1834, 1835,
and 1836. 2 Vols. Presented by the Royal Astronomical
Society.

Cicero de Natura Deorum, and Cicero de Divinatione de
Fato. 2 Vols. By Henry E. Allen, Esq. Presented by
the Author.

Three Months in the North. 1 Vol.

Dublin University Prize Poems. 1 Vol.

Letters from Mecklenburgh and Holstein. 1 Vol. By
George Downes, Esq. Presented by the Author.

Bulletin de la Société Géologique de France. Tome IX.
Feuilles 23—32. 1837 4 1839. Presented by the Society.

Reply to Professor Bischof’s Objections to the Chemical
Theory of Volcanoes. By Charles Daubeny, M.D. Pre-
sented by the Author.

Comptes Rendus Hebdomadaires des Seances de l Aca-
démie des Sciences. Par MM. les Secretaires Perpetuels.
Nos. 18—21. Premier Semestre, 1839. Presented by the
Academy.

June 24, 1839.
SIR Wm. R. HAMILTON, A.M., President, in the Chair.

His Excellency the Lord Lieutenant was present at the
meeting.

William Longfield, Esq., was elected a member of the
Academy.

326

Ir was Resotvep,—That the Treasurer be authorized
to sell off stock of the Academy to the amount of £400, if
so much be thought necessary by Council.

Professor Mac Cullagh presented and described to the
Academy an ancient Irish Cross, which formerly belonged to
the abbey of Cong, in the province of Connaught. It is a
most interesting memorial of the period preceding the Eng-
lish invasion, and shows a very high state of art in the
country at the time when it was made, which was the early
part of the twelfth century, in the reign of Therdelach Ua
Conchovar, (or Turlogh O’Conor,) father of Roderick, the
last of the native kings of Ireland. This date is supplied by
the Gaelic inscriptions, extremely clear and well cut, which
cover the silver edges of the cross, and which, besides giving
the names of the king and of contemporary dignitaries of the
church, preserve that of the artist himself, who was an Irish-
man. A Latin inscription informs us that it contains a pre-
cious relic—a portion of the wood of the “ true cross ;” and
this circumstance will account for the veneration in which it
has been held for ages, though, unfortunately, it was not
sufficient to protect it from injury, much of the ornamental
work having been removed, and part of the inscriptions torn
away. Notwithstanding these depredations, however, it is
still a splendid monument of ecclesiastical antiquity.

* In the centre of the arms, at their junction with the shaft,
there is fixed a cruciform piece of oak, marked with the
figure of a cross, and much older, apparently, than the rest
of the wood, which is oak also. This piece bears marks
of the knife, as if it had been taken for the relic; though
it is perhaps too large to be so, and, besides, it does not
appear that the true cross was made of oak. Hereabouts,
however, the relic certainly was; for the place is sur-
mounted by a very conspicuous crystal of quartz—a mode

327

of exhibiting such things that seems to be alluded to by
Chaucer in the Canterbury Tales, where he makes his
** Pardoner” say—

“ Then show I forth my longé crystal stones,

Ycrammeéd full of cloutés and of bones;

Relics they be, as weenen they each one.”

The ‘crystal stone,” indeed, in this instance, is not long,
but round, being in fact a very thick double-convex lens,
with one surface much more convex than the other ; but in
other cases, as on the cwmdachs containing the book of St.
Moling and the book of Dimma, the crystals are oblong, as
described by the poet ; and it is supposed that relics are
always to be found beneath them.

The shape of the crystal is somewhat remarkable. Thin
lenses, such as we have now, were not invented in those
days, nor for a long time after ; and the present specimen
of a thick one, which could be of no use in viewing an object,
unless placed in immediate contact with it, is to be classed
among the lenticular gems of quartz, or rock crystal, which
Dr. Priestly tells us are sometimes to be met with in the
cabinets of the curious, and which, he says, are supposed to
have belonged to the Druids.

The cross, like that of the ‘‘ gentle Pardoner” aforesaid,
is studded “ full of stones,” or rather imitations of them,
disposed at regular distances along the edges, and elsewhere.
The central crystal is surrounded by an elegant ornament in
gold ; and all the rest of the cross, both before and behind,
is richly adorned with an interwoven tracery, of that pecu-
liar kind which the Irish were so fond of. The tracery is of
solid gold ; the inscribed edging is of silver ; and both are
separated from the wooden frame by plates of copper ; the
whole being held together by nails, of which the heads are
little heads of animals. The shaft also terminates below, in
the double head of an animal, which is large, and very finely

328

executed. The end is hollow, to admit a staff, by which the
cross was carried, like the crosier of an archbishop. The
height of the shaft is about two feet and a half, and the span
of the arms about nineteen inches.

Having made the foregoing observations, suggested by
an actual inspection of the cross, Professor Mac Cullagh
said that he would leave it to Mr. Petrie to give a more
minute description of it, as well as to relate its history, how
it was made at Clonmacnoise, and thence migrated to Cong,
with many curious particulars which he had discovered
respecting it by a comparison of existing documents. Mr.
Petrie had been requested by the Academy to draw up a
paper on the subject, (see p. 212) ; and it was to be hoped
that he would soon comply with their desire.

In presenting the cross to the Academy, Professor
Mac Cullagh stated, that his motive for doing so was, by
putting it in the possession of a public body, to save it from
that shameful process of destruction to which every thing
venerable in Ireland has been exposed for centuries, and to
contribute, at the same time, to the formation of a national
collection, the want of which, he had been told, was regarded
by Sir Walter Scott as a disgrace to a country so abounding
in valuable remains. He trusted the time was not far distant
when that reproach would be no longer merited ; when the
relics of antiquity, now scattered over the kingdom, would
find their way to a place where they could be appreciated,
studied, and preserved. He believed, indeed, that there
already existed in the public mind a strong disposition in
favour of such a plan; a disposition that only required to
be awakened into action. For, no sooner had his intention
with respect to the cross become known to a few friends,
than a subscription was set on foot, to procure, for a similar
purpose, the two magnificent torques found thirty years ago
at Tara. These had travelled to England and back again,
and they narrowly escaped being sent out of the country a

329

second time, and for ever. The timely subscription was im-
mediately successful. The torques had been secured for the
Academy ; they were to be presented in the course of the
same evening; and, along with the cross of Cong, they would
help to form the nucleus of the future National Museum.
With such a beginning, it was not too much to expect a
rapid progress ; since matters so attractive and important in
themselves would naturally tend to draw others around them.

The special thanks of the Academy were voted to Pro-
fessor Mac Cullagh for his present of the Cross.

Mr. Mallet gave a notice of the present state of the
investigation, entrusted by the British Association to Pro-
fessor Davy and himself, upon the action of air and water,
whether fresh or salt, and under various modifications, upon
cast and wrought iron. From the press of other papers,
Mr. Mallet was obliged to confine himself to a very brief
notice respecting a new mode of protection which he pro-
posed for iron, when exposed to air and water.

This method is of the electro-chemical class, and is
founded on the fact, that the softer and more carbonaceous
cast irons, such as the Scotch and Irish, are in a positive
condition with respect to the less carbonaceous irons, such
as the Welch, &c., in common use for engineering purposes.

This difference of electrical condition he has found
experimentally to be sufficient to enable protectors of the
former sort of iron to be applied to the surface of the latter,
with the result of largely preventing the corrosion of the
electro-negative metal. This was shown by the exhibition
of the results of experiments which had been several
months in progress. |

It was also stated, that while tin increases the corro-
sion of iron, contrary to the opinion of Sir Humphry Davy,
zinc does not seem to possess a protective power wholly
permanent, at least in salt water, from the formation on its

330

surface, after a lapse of three years or more, of insoluble
crystals of carbonate lime, having the form and hardness of
cale spar, which prevent chemical action on the metal.

The Rev. H. Lloyd, V. P., read a paper descriptive of
the Magnetical Observatory of Dublin, and of the instru-
ments and modes of observation employed there. After
some prefatory remarks on the anomalous movements of the
magnetic declination, and on the establishment of magnetical
stations which took its rise from their study, the author pro-
ceeded to the immediate subject of his communication.

The Magnetical Observatory of Dublin was erected by
order of the Board of Trinity College, the funds being sup-
plied from the College chest. ‘The building was commenced
in the summer of the year 1837, and was completed in the
course of the following year. The structure, which is of the
Doric order, is situated in an open space in the gardens
attached to the College: its dimensions are forty feet in
length, by thirty in depth. It is constructed of Portland
stone, the interior stone of -the building being the argil-
laceous limestone (calpe) of the valley of Dublin; several
specimens of each of these stones had been previously sub-
mitted to a rigid examination, and found to be entirely
devoid of any effect upon the magnetic needle. The interior
walls of the building are studded, for the purpose of main-
taining a uniform temperature, as well as to protect from
damp. The nails employed in the woodwork are of copper,
and the other metallic fastenings (locks, hinges, &c.,) of brass;
no iron whatever being used in any part of the building.

The interior is divided into one principal room and two
smaller rooms; one of the latter serving as a closet, and the
other as a vestibule. The principal room is thirty-six feet
in length, by sixteen in breadth; and has projections in its
longer sides, which increase the breadth of the central part
to twenty feet. ‘This room is lighted by a dome light at top,

331 ‘

and by a window at each end. It contains six stone pillars
for the support of the instruments: these are imbedded in
solid masonry beneath the floor, and the supports of the
floor are framed around them, so that they are completely
insulated.

The elements on which the determination of the earth’s
magnetic force is usually based are, the declination, the in-
clination, and the intensity. Ifa vertical plane be conceived
to pass through the direction of the force, that direction
will be determined when its inclination to the horizon is
given, as well as the angle which the plane itself forms with
the meridian; and if, in addition to these quantities, we like-
wise know the number which expresses the ratio of the in-
tensity of the force to some established unit, it is manifest
that the force is completely determined.

For many purposes, however, and especially in the deli-
cate researches connected with the variations of the magnetic
force, a different system of elements is preferable. If the
intensity be resolved into two portions in the plane of the
magnetic meridian, one of them horizontal and the other
vertical, it is manifest that these two components may be
substituted for the total intensity and the inclination ; while,
at the same time, their changes may be determined with far
greater precision. The former variables are connected with
the latter by the relations

X=RCcOSu, Y=RsInNU;
in which r denotes the intensity, x and y its horizontal
and vertical components, and zw the inclination. It will be
easily seen that the variations of u and R are expressed in
terms of the variations of x and y by the following formule :

du = sinucosu(=— =);

x
OR oy

ox
soe 2 sD)
—— = COS u— + sin u-—.
R x Y

Mr. Lloyd then proceeded to describe the instruments

332

employed in the determination of these elements and their
changes.

The magnet of the declination instrument is a rectangular
bar, fifteen inches long, suspended by parallel silk fibres,
and enclosed in a box to protect it from the agitation of the
air. In addition to the stirrup, by which the bar is sus-
pended, it is likewise furnished with two sliding pieces, one
near each end of the bar. One of these pieces contains an
achromatic lens, and the other a finely divided scale of glass ;
the scale being adjusted to the focus of the lens, it is
manifest that the apparatus constitutes a moving collima-
tor, and that its absolute position at any instant, as well as
its changes of position from one instant to another, may be
read off by a telescope at adistance. The stirrup is so con-
trived as to enable the observer to invert the bar, and thus,
by the mean of the two readings, to determine the point of
the scale corresponding to its magnetic axis.

The framework of the instrument consists of two pillars
of copper, thirty-five inches in height, firmly screwed to a
massive slab of marble. These pillars are connected by
two cross pieces of wood—one at the top, and the other
seven inches from the bottom. In the centre of the top
piece is the suspension apparatus, and a divided circle used
in determining the amount of torsion of the thread. A glass
tube, between this and the middle of the lower cross-piece,
encloses the suspension thread; and a glass cap at top
covers the suspension apparatus, and completes the en-
closure of the instrument.

The box is cylindrical, and has two apertures opposite
to each other. The aperture in front, used for reading, is
covered by a circular piece of parallel glass, attached to a
rectangular frame of wood which moves in dovetails; the
prismatic error of the glass (if any) is corrected by simply
reversing the slider in the dovetails. The opposite aperture
is used for the purpose of illuminating the scale.

333

The apparatus is likewise provided with a brass bar (aiso
furnished with a collimator) for the purpose of determining
the plane of detorsion of the suspension thread ;—a thermo-
meter, the bulb of which enters the box, in order to deter-
mine the interior temperature ;—and a copper ring, used in
checking the vibrations.

The instrument used in determining the horizontal com-
ponent of the magnetic force is a magnet bar suspended by
two parallel wires, and maintained, by the torsion of their
upper extremities, in a position at right angles to the mag-
netic meridian. The directive force due to the mode of
suspension is known, when we know the weight of the sus-
pended body, the interval of the wires, and their length;
and the ratio of this force to the horizontal component of
the magnetic force is given, when we know the angle through
which the upper extremities of the wines have been turned,
in bringing the suspended bar into the perpendicular posi-
tion. The magnet being thus maintained in its position by
the action of two forces, one of which (the torsion force) is
constant, while the other (the magnetic force) is variable, it
is manifest that its place will vary around its mean position;
and that these variations of angle are connected with the
variations of the force, so that when the former are given, the
latter are known. The variations of the angle are read off,
as in the other instrument, by a collimator and divided scale;
and the delicacy of the instrument is such, that (with the
adjustment of the parts at present in use in the Observatory)
we may estimate changes in the horizontal force amounting
to sp4gath part of the whole.

The larger parts of this apparatus,—the box, the frarne-
work, and the support,—are precisely similar to those of
the declination instrument. There are, however, several
differences in the essential parts of the instrument, arising
chiefly from the different nature of the suspension. The

collimator is-attached to the stirrup, and has a motion in
2G

oo4

azimuth, an arrangement which is necessary in the adjust-
ments. The suspending wire passes round a small grooved
wheel, on the axis of which the stirrup rests by inverted Ys;
and the instrument is furnished with a series of such wheels,
of different diameters, for the purpose of varying the interval
of the wires. This interval is altered, at the upper extre-
mity, by means of two screws (one right handed and the
other left handed,) cut in the same cylinder; the wires being
lodged in the intervals of the threads, and their distance re-
gulated by means of a micrometer head.

The third instrument is that used in determining the
changes in the vertical component of the magnetic force. It
is a magnet resting on agate planes, by knife edges, and
brought to the horizontal position by weights. There is a
small cross of wires near each end, and the changes of posi-
tion of the magnet are read off by a pair of microscopes.
From these changes of position, the changes of the ver-
tical force are inferred, when we know the inclination at the
place of observation, the azimuth of the plane in which the
needle moves, and the angle which the line connecting the
centre of gravity and centre of motion makes with the mag-
netic axis of the needle. As the determination of this latter
constant would require that considerable additions should
be made to the apparatus, Mr. Lloyd has preferred to adjust
the weights so that the angle in question shall be nothing.
The weights are small brass screws moving in fixed nuts, one
on each arm; the axis of one of these screws is perpendicular
to the magnetic axis of the bar, and its movement conse-
quently produces the desired adjustment; the other screw
(the heavier) is parallel to the magnetic axis, and serves to
adjust the magnet to the horizontal position. Each of these
adjustments admits of an easy test.

The supports of the magnet, and of the ee are
firmly attached to a massive slab of marble, which is ce-
mented to the stone pillar on which it is placed; and a spirit-

339

level, attached to the base, serves to indicate any change
which may occur in the level of the instrument. The magnet
is of course covered with a box, to protect it from the agita-
tion of the air; and the apparatus is furnished with several
minor pieces, which are employed in the various adjustments.

In addition to these instruments, which are those in con-
stant use, the Observatory is furnished with an inclination
instrument and a pair of needles, made by Gambey; a transit
instrument and large theodolite, used chiefly in determining
the absolute declination; a transit clock and a chronometer ;
and a complete set of meteorological instruments.

Mr. Lloyd closed his communication with a brief account
of the important undertaking in which her Majesty’s Govern-
ment had recently engaged, for the purpose of advancing the
knowledge of Terrestrial Magnetism—an undertaking which
he characterized as the vastest in its design, as it might also
be expected to be the most fruitful in its results, of any which
the British, or any other government, had ever engaged in,
in behalf of science.

The Secretary read the following communications from
George James Knox, Esq., giving an account of his further
researches on Fluorine:

1. On the Insulation of Fluorine.

“In a paper on the Insulation of Fluorine which the Rev.
Thomas Knox and I had the honor of presenting to the
Royal Irish Academy in the year 1837, and which was after-
wards published in their Transactions, (vol. xviii. p. 127,) we
proved that we had obtained fluorine in an insulated state,
by shewing its action upon bismuth, palladium, and gold;
but being unable, from our mode of experimenting, to deter-
mine what the nature of fluorine at ordinary temperatures
might be, i.e. whether it be a solid, a liquid, or a gas, we
suggested that such information might be obtained from the

2@2

306

electrolization of a fluoride, using as the positive electrode
some substance with which this energetic principle should
not enter into chemical combination.

‘‘ Finding that, since the publication of our paper, no per-
son had entered upon this field of investigation, I considered
that the ultimate solution of this problem devolved as a
point of duty upen myself; under which impression I un-
dertook the following experiments.

« A fluorspar stopper was made to fit the mouth of one of
the fluorspar vessels described in our former paper; that
part of the stopper within the vessel being made of the form
of a semi-cone, the vertex of which reached nearly to the
bottom of the vessel. Through the stopper were drilled ver-
tically three small holes, one through its entire length, the
other two through one-third of its length. In the first
was inserted a platinum wire, to be used as the negative
electrode; in one of the two small holes was inserted a thin
platinum wire, bound round a piece of charcoal, intended to
form the positive electrode; in the other hole I put gold
leaf, litmus, or any other substance upon which I wished to
try the action of the gas. Matters being so arranged, the
fluorspar vessel was about half filled with anhydrous hydro-
fluoric acid, the chemical purity of which had been previously
ascertained. The platinum wire forming the negative elec-
trode was raised a little above the bottom of the stopper, in
order to allow the bubbles of hydrogen to rise through the
perforation in the stopper, in place of mixing with the fluo-
rine in the vessel; the wires were then placed in contact
with the poles of a constant battery of sixty pair of plates,
and the action was allowed to continue for the space of two
hours; at the end of which time the litmus was found to be
reddened, and the gold not acted upon, but a large quantity
of subfluoride of iron formed.

“In the next experiment I made use of a piece of char-
coal, from which the iron had been removed by boiling it in

337

nitric acid; in this experiment there was no subfluoride of
iron formed, but the vessel was found to contain fluosilicic
acid gas,

“In a third experiment a piece of charcoal was employed,
which had been previously freed from all metallic impurities
and from silica, by being first boiled in pure nitric acid, and
afterwards in hydrofluoric acid. Employing this purified
charcoal as the positive electrode, I obtained no immediate
action upon the litmus paper; but after the action had conti-
nued for two hours, it was found to be completely bleached,
while the gold had undergone no sensible action. That the
bleaching was not due to the action of the vapour of hydro-
fluoric acid was ascertained, by leaving litmus paper for
several hours in the neck of a platinum retort, from which
hydrofluoric acid was distilling.

“The battery was now kept in action for fifteen hours, at
the end of which time the vessel being examined, the litmus
had disappeared, and the gold leaf showed signs of having
been strongly acted upon, having assumed a dark brownish
colour, and having gathered itself into little balls, as if it
had undergone the action of heat. The platinum wire was
acted upon in those parts where it was in contact with the
charcoal, but no where else.

** When the platinum wire forming the positive electrode
passed through the stopper to the bottom of the vessel, the
hydrogen, in place of rising through the perforation in the
stopper, as in the former instance, rose now into the re-
ceiver, where, upon applying a light, it exploded, showing
that it does not enter into combination with fluorine without
the aid of heat. The presence of the vapour of hydrofluoric
acid in the vessel prevented me from determining by other
experiments how far fluorine was a supporter of combustion.

“To determine the colour of the gas, a stopper of fluorspar
similar to the former was made to fit one of the transparent
fluorspar receivers formerly described. The gas evolved in
the receiver appeared colourless.

338

“« As the action of the gas upon glass could not be deter-
mined, owing to the presence ofthe vapour of hydrofluoric acid,
Ifusedin a bent tube of German glass (such as is used inorganic
analysis) fluoride of lead. The wire holding the charcoal was
made to pass through a cork inserted in one end of the tube,
the other platinum wire merely dipped into the fused fluoride.
On connecting the wires with the battery, strong electrolytic
action commenced, bubbles of gas were evolved rapidly at
the surface of the charcoal, which, on arriving at the surface
of the fused fluoride of lead, acted instantly upon the glass.
The litmus paper was not bleached, nor the gold leaf or
platinum wire acted upon. Whether fluorine would act
upon perfectly dry cold glass remains to be proved.

“ Conclusion.—F luorine then, when obtained in an insulated
state, is a colourless gas, possessing properties analogous in
all respects to those of chlorine; having, like it, strong at-
tractive powers for hydrogen and metals, but inferior to it
in negative electrical energy.”

2, Note on a Compound of Fluorine with Selenium.

*‘ When the vapour of selenium is passed over fluoride of
lead fused in the platinum apparatus employed in obtaining
the fluorides of carbon and cyanogen, a seleniuret of lead is
formed, and erystals similar in form to those of fluoride of
earbon are condensed in the cold receiver. These crystals
are soluble in strong hydrofluoric acid. They sublime un-
altered at a high temperature. They are instantly decom-
posed by water or acids, in which property they resemble the
fluorides of sulphur and phosphorus.”

The President read a paper, by the Rev. Dr. Robinson,
M.R.LA., &c., on the recent Employment of Rockets to
determine the Difference of Longitudes of Armagh and
Dublin, and on the proposed Extension of this Operation to
other British Observatories.

In this paper, after alluding to the recommendation of the

3389

British Association at Edinburgh, and reviewing the history of
the principal operations of the kind which have been hitherto
performed, the author remarks that the Observatory of
Armagh is unfavorably situated for comparison by signals
with that of Dublin, though the distance is but sixty-eight
miles; there being ground about four miles to the south of
Armagh from 700 to 1200 feet of height; and a ridge from
600 to 400 feet high, about fourteen miles north of Dublin.
Lieutenant Larcom investigated all possible stations, giving
for each its distance and azimuth, and the height above its
summit to which the signal should be elevated to make it
visible from both observatories. His help was of essential
importance; and in consequence of the data supplied by
him, the station Slieve Gullion was adopted; which is 1893
feet high, and is distant eighteen miles from Armagh and
fifty-one from Dublin, . At the latter its summit is a few
seconds above the boundary of view, but, at the former, so
much below that boundary, that a height of 800 feet above
the summit would be required to clear it. Rockets were
therefore necessary, and on applying for them to the
Honourable Board of Ordnance, they were supplied from
Woolwich with the utmost liberality.

In the operations alluded to above, the rockets (supplied
by the French Goverment) were what is called 2lbs. and
carried 8 oz. of powder; a very great number of them did
not rise to a sufficient height; and Dr. Robinson thought it
unsafe to use any of less dimensions.

The Ordnance also provided tents for the firing party
and an escort of police was granted by Lieut.-Colonel
M‘Gregor for their protection, which however proved quite
unnecessary.

On the 13th of May they were dispatched to the mountain,
under the orders of Dr. Robinson’s eldest son, and established
there in a few hours by the kind aid of the Rev. Dr. Camp-
bell, Rector of Forkhill, which removed every difficulty ; and

340

though it was very tempestuous, there were fired fourteett
tockets on the 14th, thirteen on the 15th, twenty on the 20th,
twenty onthe 21st, and nine on the 23rd, in all seventy-six.
Of these, sixty-three were observed at Armagh, and fifty-
three at Dublin, but only forty-two were simultaneous. The
explosions were visible to the naked eye at Armagh, and
to an ordinary nightglass at Dublin; they were however
observed, at the latter, by Sir William Hamilton and Mr.
Thompson, his assistant, with the equatorial of five inches
aperture, and the dome clock; at the former by Dr. Robinson
with the finder of his great equatorial (two inches three-fourths
aperture) and its clock, and by Mr. Edmonson, his assistant,
with a telescope (3,2 inches aperture) and the transit clock.
A third observer also (but one not. much practised) observed
them with the west equatorial.

The time at each observatory was determined by a list
of stars previously selected and reduced by the places of
Encke’s Jahrbuch, so that it is conceived there ean be no
uncertainty in the work except what arises from the personal
equations of the observers, which Dr. Robinson hopes to
determine on his way to Birmingham. ‘The numbers of the
stars used on each night are stated, and also the probable
errors of transit and rocket observations; and the probable
mean of the whole work is inferred to give for the difference
of longitudes of the two observatories, 1™ 14%, 425, exceeding
the result of Mr. Dent’s chronometers by 0°, 035.

The prosecution of these observations was interrupted
by the full moon, but the certainty of their result appears
sufficient without resuming them. As however there is a
mountain in Leitrim where the rockets will be visible at once
from Armagh, Dublin, and Mr. Cooper’s Observatory of
Markree, in Sligo, the determination of the latter apppears
sufficiently important to make Dr. Robinson select that
station in case of pursuing the matter any further. But it
is even more important to cross the Channel. These 2lb.

341

tockets rose 800 yards; if fired at Plinlimmon, they will be
visible at Dublin, and probably even at Oxford; on the
other hand, from Knocklaid, near Ballycastle, county Antrim,
they could be seen at points on the west coast of Scotland,
which see Ben Lomond, and can be joined by powder signals
on it with Edinburgh. This however would require a transit
instrument to be established, but the object to be effected is
so important that Dr. Robinson hopes to accomplish it.

The President concluded his account of his First Series
of Researches respecting Vibration, connected with the
Theory of Light. The following is an outline of one of the
investigations which are contained in the Series referred to.

It is proposed to integrate the system of equations in
mixed differences,

D/O#, ,=3,,5(R- A, #, »)3 (1)

in which # is any integer number from 1 to z inclusive;

th is independent of ¢, but dx, , is a function of ¢ and of
? 6?

Eiprere, 49 the form of which function it is the object of the
problem to discover ;
= 1 n 2
R= OSA g 0G ZayilA, a ") ); (2)
@ being any real function of the semi-sum which follows it,
and m being any other real function of the index g +Ag;
while g and g+Ag represent any integer numbers from

negative to positive infinity. The equations to be integrated
may also be thus written:

ZA

= Sete, AC oe

R’ A,%
g,h,t Ag & Eyhyt a

"gh Say g Gane & E atut)? (1)
in which
me ” 2)\. ,
ss ainpectee #QZ 1G, 0) )i 4

the functions to be found by integration are now those of

342

the form a 142 considered as depending on ¢ and on
ft
@ pre, a3 their initial values, and initial rates of increase
oD)
> 7 7 7
(relatively to ¢), namely & of 0 and On 4,02 ate regarded as
arbitrary but given and real functions of wpe o, “a it is
3 3

also supposed, in order to simplify the question, that all the
sums of the forms

a, A a

ae of Aye a a 2B Ati) |
A ie
( a Me, n) ;

are independent of g, and are = 0 when any one of the ex-
ponents a,,...a, is an odd number. These equations are

(3)

analogous to, and include, those which M. Cauchy has con-
sidered in his memoir on the Dispersion of Light, and may
be integrated by a similar analysis.

A particular integral system may in the first place be
found by assuming

Ca hyt XA, , 08 (E, +s it— Son : ©, ii (4)
gee

Zay1 Air = 3 (5)

4

5. wich ai iy Zw H ht thes i (6)

H,,= =,,(R-+R’(A, 2, ,)) vers (s Zt u, A yi 3 ‘ (7)

— A rd
4 = =2, Age ng Ue, i VERS (3, 4,4, aE (7y

the index r being any integer from 1 to.7, and being intro-
duced in order to distinguish among themselves the x dif-
ferent (and in general real) systems of values of s’, and of the
n—1 ratios of A,,-.4,,--A,, which are obtained by resolving

the system of the 7 equations of the form

343

g —_v n 6 ,
Siig acimal eae ae (6)

in which, by (7),

zs rN IT
HS He (7)

It is important to observe, that by the form of these equa-

tions (6)’, (which occur in many researches,) we have the

relation
na

201 A, q A s 0, Oy

if q be different from 2; and that, by (5) and (5)’, we have
also the relations

a ae
21 ar ro 1, (8)
= 1 Ayr Air = 0. (8y

In the particular integral (4), we may consider Usps + ot
n
as arbitrary parameters, of which x_ and « are real and ar-
bitrary, while s*. and a, are real and determined functions ;
3

and hence, by summations relatively to the index 7, and
integrations relatively to the parameters u,, employing also

the relations (5) (5)' (8) (8)’, and Fourier’s theorem ex-
tended to several variables, we deduce this general integral,
applying to all arbitrary real values of the initial data:

c hyt =(11,;\ _du,) ee cos +F, é sin) 3 @l ie, wi (9)

in which
ie By = CAM me eee \" ee (10)
En. zai Las (%, cos ts -+ Y' cae sin ts,)>
(11)

pineal ie ;
= 3914 ee (2, cos ts + z's sin is, |

n ,

g ee SB
= > hoe
ar ry Xa) ran ae 0’ r lh h,0? Fo
| (12)
n a= “ah
Z,= 2 ay1 Sige Fn,0° 2ay1 Ane Fi, 0

UX
ERO = (=)'( (1,2 ma & sah 0 h,0 @I i g,i

rE’ gee) "ue ,
h,0 2 =(5-) (a (G Ae Fy g,h, 0 (=.,1 i gyi
3 “0 | 13)
Vas (-)" (n Ve dx, % gE oy Ux x
£7,0 2Qr. @1J—« g, h, 0 21 i g,i |
f =( : Hl ae d \e sin(3,." Ub. % a
Find = OS ay benee Bayi g,h,0 (j1 t St

This general solution involves multiple integrals, of the
order 2n; but many particular suppositions, respecting the
initial data, conduct to simpler expressions, among which the
following appear worthy of remark.

Suppose that having assumed some particular set
w',.-.w, of values of the » arbitrary quantities Uyy++-U,

v?
we deduce a corresponding set of coefficients H' hy? H ne PY
the formule (7) and (7), and represent by sy 2 and by
Ap Ay ree some one corresponding system of

quantities which satisfy the equations

no s2 <\
@14n1— 45 (5)

N28 2c Nios Q f \\
ec Mamie ass We or oF aeRO (6)

we shall then have, as a particular integral system, that
which is thus denoted:

od A A ry 4 9 ‘
Soht = * 1 Ay C8(e, Fst — Fit a i i)3 (4)

x and ¢«, denoting here any arbitrary real quantities. If

345

therefore we suppose that the initial data ae and &’
are all such as to agree with this particular solution, that is,
if we have, for all values of g and h,

Fao = 1 An O21 2oy 1%; rae (14)

” QUENT AN ° A
S_X_A sin ( €
Gis

= ,
o5h0 = 171° &,1 1% ae i}? (14)

we see, @ priori, that the multiple integrations ought to
admit of being all effected in finite terms, so as to reduce
the general expression (9) to the particular form (4); an
expectation which the calculation, accordingly, @ posterioré,
proves to be correct. An analogous but less simple re-
duction takes place, when we suppose that the initial
equations (14) and (14) hold good, after their second mem-
bers have been multiplied by a discontinuous factor such as

a(1 Ri a “sin(&3, jade. ua) an), (15)
0 k

7

which is = 1, or = 1, or = 0, according as the sum

Za: a, ; 1s < 0,or=0, or>0. It is found that, in this

case, the 2 2n successive integrations (required for the general
solution) can in part be completely effected, and in the
remaining part be reduced to the calculation of a simple
definite integral ; in such a manner that the expression (9)
now reduces itself rigorously to the following :

As si 7
Eke = 2X14), 1 co8(ey +its’, Zot : ©, i) |
1 ° dk pete)
pe xh eae (L,cos 2, anh. sin £,)3 |
in which
L,= Pk cos kx —@ ksinke, |
a tah (17)
M,= Pk sinke + @,k coska, |

346

n =I:
Pee A ,
Sel (4,,8, sinis,. = “is see An)»

4
: (18)
= 2 ry
@, = 2, (Ap, C08 ds, « Za Ane A nr)?
> ns 19
mle tea? )
Pyke ENV DONT Liye Sh aN Ng oe ny ;
ka’, = u,, Ka.=u.,, Co ce? (20)

and $ ,A, are the same functions as before of UsyreeU
;

A remarkable conclusion may now be drawn from these
expressions, by supposing that all the quantities of the
form s” are not only real but positive, so that the functions

cos ¢s_and sin és, are periodic. For in this case the func-
tions cos (¢s_ + ka) and sin (¢s_ = Ax) will vary rapidly, and
pass often through all their fluctuations of value, between

the limits 1 and —1, while & and the other functions of
that variable remain almost unchanged, provided that

eee large, and that the denominator 4? — k” is not
extremely small. We may therefore in general confine
ourselves to the consideration of small values of this deno-
minator; and consequently may put it under the form
2k (k — i’), making k= kin the numerator, except under
the periodical signs, and integrating relatively to & between
any two limits which include %, for example between
—o and +o. And because

ns 4 ah cae
ZoyiAnrdni = bor = 0,

according as 7 = 1 or >1, we may make

PAN c ens
ve =Any sin tS 1 a= AS cos ts,,

Be opera : wa! ped AS Srse7
L,= k A’, Sin (és, ka), M,= k A’, 1 COS (és, kx)

and

,— FX,A 1

S cos (¢, + ts, — Fa) ita gy Sette) | (21)

A

that is, nearly, if x be considerably different from ie P

St =x ia 11 CO8(Ey + ts, — Kx)
co Qly
ds\ ) (
ar 5m (FE 4) §-
We have therefore the approximate expressions:
\ ds
Sones tag OOK yt aie ee Ss ee)
and
Bo ye 0, 4h eS oe (22)
SG Ris dk’
we have also nearly, in general,
=x‘ a’ cos (e+ ts — Fx), if x rp Biss (22)"
Ae g° sh hyl Ge 1 ir Ce = dk?

: : S ds’, .
but the discussion of the case when x is nearly = tris too

long to be cited here. The formula (22) for ce 4, ¢ Coin-

cides with the particular integral (4)'; and the condition
which it involves with respect to x, expresses the law ac-
cording to which this particular integral comes to be
mae true for greater and greater positive values of x and

t, ae *>0,) after having been true only for negative values

ii
of x when ¢ was = 0.

In the particular case » = 3, the foregoing formule
have an immediate dynamical application, and correspond
to the propagation of vibratory motion through a system of
mutually attracting or repelling particles ; and they conduct

348

to this remarkable result, that the velocity with which such
vibration spreads into those portions of the vibratory medium
which were previously undisturbed, is in general different from
the velocity of a passage of a given phase from one particle to
another within that portion of the medium which is already
fully agitated ; since we have

(A)

velocity of transmission of phase = _
but

velocity of propagation of vibratory motion = (B)

ds
Lin
if the rectangular components of the vibrations themselves
be represented by the formule

XA COS (e-+-st—kx), XA» cos (e++st—kx), xa3cos (est —ka), (C)

t being the time, and z being the perpendicular distance of
the vibrating point from some determined plane.

This result, which is believed to be new, includes as a
particular case that which was stated in a former communi-
cation to the Academy, on the 11th of February last,
(Proceedings, No. 15, page 269,) respecting the propa-
gation of transversal vibration along a row of equal
and equidistant particles, of which each attracts the two
that are immediately before and behind it; in which par-

ticular question s was = 2a sin 5° and the velocity of pro-

pagation of vibration was = a cos = Applied to the theory

of light, it appears to show that if the phase of vibration
in an ordinary dispersive medium be represented for some
one colour by

eT E—*) oy

so that \ is the length of an undulation for that colour and

349

for that medium, and if it be permitted to represent dis-
3 : ier oi ere
persion by developing the velocity — of the transmission of
fe

phase in a series of the form
1 2 2 ,
—= Mo —m(F yi +m (> aay — &e., (A)

then the velocity wherewith light of this colour conquers
darkness, in this dispersive medium, by the spreading of
vibration into parts which were not vibrating before, is some-

1 : 2 .
what less than Pi being represented by this other series

— 3M, (= ary + 5M Sher &e. (BY

For other details of this inquiry it is necessary to refer
to the memoir itself, which will be published in the Trans-
actions of the Academy, and will be found to contain many
other investigations respecting vibrating systems, with ap-
plications to the theory of light.

The two golden torques found at Tara, and exhibited
on a former occasion by Mr. Petrie (see ProcrEpines,
p- 274), having been purchased from Messrs. West by sub-
scription, they were this evening presented to the Acatleny
by Mr. Petrie, in the name of the subscribers.

It was Resouvep—That the Subscription List be printed*
in the Procrrepines; and that the marked thanks of the
Academy be given to those gentlemen, who, not being mem-
bers thereof, joined in the subscription.

* Tt will be found under the head of Donations.

350

The President delivered the following Address :

Before the present session closes, as it is now about to do, Iam
to inform you, that your Council have continued to consider the
expediency of awarding any medal or medals, from the resources of
the Cunningham Fund, to any of the papers which had been com-
municated to us for publication, within the last few years, and which
had not previously been so distinguished; adopting still the same
plan of triennial cycles, and the same principles connected with that
plan, which have been announced to you on former occasions ; and
thinking themselves bound to lean rather to the side of caution, than
to that of indulgence, in deliberating on questions of this kind.
The award of a medal, in the name of a learned body, is attended
with a grave responsibility. It does not indeed pronounce, in the
name of the Society, on the rigorous accuracy, or perfect novelty,
of the paper which is thus marked out; but it at least offers the
peculiar thanks of that Society to the author of that paper, and
expresses a desire, on the part of the body, to be connected, to a
peculiar degree, in present observation and in future history, with
the communication for which the honour is awarded. The with-
holding of a medal is, for the converse reason, no expression of
unfavourable opinion, nor any denial of the existence of a large
share of positive merit in the paper or papers which it is thus for-
borne to distinguish : even when the principle of competition does
not happen to come into play, and when no other essay, of the
same class and cycle, is adjudged to have superior pretensions. It
has, however, appeared to your Council, that they were authorized
and bound to award a medal to Mr. Petrie, for his Paper on thes
History and Antiquities of Tara Hill, printed in the Second Part of
the Eighteenth Volume of the Transactions of this Academy; as
being, in their opinion, the most important of those which were
communicated to us, during the three years ending with December,
1838, in the departments of Polite Literature and Antiquities ; and
as possessing also such amount of positive merit and interest as to
entitle it to this mark of distinction. Having attended the discus-
sions which took place in the Committees on the merits of the va-
rious papers, and on Mr. Petrie’s Essay in particular, I shall venture

351

now to lay before you, in the briefest possible manner, a few of the
grounds of this award ; without attempting to offer a complete state-
ment of those grounds, or anything approaching to a full analysis
of the memoir itself, which memoir indeed will very soon, be in
your hands.

Mr. Petrie’s Essay may be considered as consisting of two prin-
cipal parts: the first containing an account of Events connected with
Tara, compiled from Irish manuscripts and illustrative of the His-
tory of Ireland; and the second part being devoted to an identifica-
tion of the existing Remains, including an examination of the various
descriptive notices also contained in ancient Irish manuscripts. The
documents brought forward, possess a great degree of curiosity
and interest; many of them, also, are now for the first time pub-
lished ; and (which is of importance to observe) are given in an
entire, unmutilated form ; accompanied with literal translations, and
with philological and other notes, adapted to increase their value
to the student of the ancient literature and history of Ireland. And
what gives to these literary relics a value and an interest perhaps
greater than, or at least different from, what might attach to them if
considered merely as curious fragments, illustrative of the mode of
thinking and feeling in times long passed away, is the circumstance
that the accuracy of their topographical descriptions has been tested
by recent and careful examination. The resources of the Ordnance
Survey have been called in, to check or to confirm, by appeal to exist-
ing vestiges, the statements still preserved of the writers of former
centuries, respecting the relics of what was even then an ancient and
almost forgotten greatness; the time-worn traces have been mea-
sured, and compared with those old descriptions; and an agreement
has been found, which establishes as well the truly wonderful anti-
quity of the remains still to be found at Tara, on what was once, and
for so many centuries, the royal hill of Ireland, as the correctness
and authenticity of documents, which it has been little the fashion
to esteem.

It is this clear establishment of the authenticity of what had been
commonly thought doubtful, this employment of a manifestly rigorous
method of inquiry in what had seemed to many persons a region of
fancy and of fable, in a word this evident approach to the character
of scientific proof, which has made (I own) a stronger impression on

392

my own mind, and (I believe) on the minds of others too, than even
the literary and antiquarian interest of those curious and valuable
details (such as the Hymn of Patrick, and the particulars respecting
the Lia Fail, or ancient Coronation Stone of Ireland,) brought for-
ward in the present Essay. I shall not venture here to give utterance
to any opinion respecting the extent to which the once common and
still lingering prejudice against the value and authenticity of Irish
Manuscripts, almost against the very existence of any ancient History
or Literature of Ireland, may have been removed or exposed before,
by the labours of other antiquaries. But it may be allowed me to
express a conviction, that it is only by pursuing some such plan as that
exemplified in Mr. Petrie’s Essay, namely, by a diligent examination
of existing Irish Manuscripts, and of existing Irish Remains, and by an
unreserved publication of all which may be found in the one and in
the other, that full historic certainty can be attained, respecting the
ancient state of Ireland. And that if, on the other hand, this dili-
gent search be made, and this full and free publication, they will not
fail to produce a clearness and convergence of opinions, among all
who attend to these subjects ; and will throw such a steady light,
not on Irish History alone, but on other cognate histories, as will
repay the labour and expense required for such an enterprize.

The Royal Irish Academy has already, from its limited means,
contributed much to accomplish this object, or to prepare materials
for accomplishing it. By purchase or transcription, we have gra-
dually collected originals, or carefully collated copies, of many of
the most valuable manuscripts which are extant, in the ancient
Trish language. At ano slight expense, our volumes of Transactions
have been and still continue open to receive such fruits of diligent
and judicious research, in this department of study, as are contained
in the paper on Tara. The sum which, by a recent vote, has been
placed at the disposal of the Council, will enable them to push on
with vigour the printing and engraving of that other elaborate work
of the same author, which was honoured with the award of a medal
here some years ago,—the Essay (by Mr. Petrie) on the Round
Towers of Ireland. And the liberality of Members concurs with
that of extern Subscribers to place, from time to time, upon our
table, such splendid donations of ancient Irish Relics, as the Cross
and the Torques of this evening.

353

It is, however, to the resources of the Nation that we must look,
to aid us in accomplishing what is truly a national object. As it was
long ago pronounced to be a symptom of the health of a State, and
an element in its well-being, that all should interest themselves in
the weal of each, and that if one member suffer, the whole body
should suffer with it; in order that thus whatever injury was
offered to a part might be repelled by the energy of the whole, and
that every limb might be animated by one pervading vigour: so too
it is another fruit and sign of the dignity and happiness of brother-
hood, another opposite and contrast to the misery of savage isola-
tion, when not the present only of a nation’s life, but the past and
future also are regarded with a vivid interest ; and, caring for poste-
rity, men care for their ancestors likewise. Each people owes it to
the human race, to do what in it lies for preserving its own separate
history, and guarding its own annals from decay: and each, accord-
ing to its power, should cheer and help the rest in their exertions to
accomplish this, which is an object common to all. Ireland is rich
in records of an ancient civilization ; and looks with a just hope to
Britain for assistance towards rescuing those records from obli-
vion, and from the risk of perishing obscurely. Though this Aca-
demy possesses many manuscripts, and although many are contained
in the Library of our national University, enough has not been done
until they have been placed beyond all danger of destruction, and
made accessible to students every where, by printing and by publish-
ing them, with notes and with translations, such as can be sup-
plied by some of the few persons who are now versed in the ancient
Irish Language. For doing all this well, opportunities can now be
had, which the lapse of a generation may almost remove, which the
casualties of each year may diminish.

We have had more occasions than one to hear, this evening, of the
assistance recently and wisely given by Government to Science. Nor
ought (I think) the presence of the representative of our Sovereign
and Patron, to restrain me from avowing the hope, in which you all
will join, that our desire, long since expressed, for the publication of
our Irish Records, may after no long time be granted; and that the
State may soon resolve to undertake, or to assist in undertaking, a
task for which the materials and the labourers are ready, but of which

354

the expense, though to a Nation trifling, is too great for an Academy
to bear.

Of the possibility of accomplishing that task, and of the fruit
which may be expected from so doing, if a proof and specimen }
sought, they may be found in that Essay, on the History and Anti-
quities of Tara Hill, for which I now, in the name of this Academy,
present this Medal to its Author.

The President then delivered the Gold Medal to George
Petrie, Esq., R.H.A., M.R.LA., and the Academy adjourned
to November.

DONATIONS.

The Cross of Cong. Presented by Professor Mac Cul-
lagh.

Bulletins de 0 Académie Royale des Sciences et Belles-
Lettres de Bruxelles. Presented by the Academy.

Two golden Torques found at Tara. Presented by the
Subscribers.

LIST? OF SUBSCRIBERS TO THE TORQUES.

The Gentlemen whose names are marked thus *, are not Members of the Academy.

£s. d. £ os. d.

Professor MacCullagh . 1010 0] Rev. Dr. Singer, F.T.C.D. 2 2 0

Robert Callwell, Esq. - 10 10 O| Rev. Dr. Elrington, F.T.C.D. 2 2 0

T. A. Larcom, Esq., R. E. 5 5 0O| Rev. J. H. Todd, F.T.C.D. 5 5 0

William Stokes, M.D. - 5 5 O| Rev. W. D. Sadleir, F.T.C.D. 2 2 0

Aquilla Smith, M.D. - 2 2 0} Rev. C. Graves, F.T.C.D.. 2 2 0

James Pim, Jun., Esq. . 2 2 O]| Rev. R.V. Dixon, F.T.C.D. 1 1 0

Thomas Coulter, M.D. . 2 2 0| A.S. Hart, Esq. F.T.C.D. 2 2 0

George Petrie, Esq. . - 1 1 O| Rev. T. M‘Neece, F.T.C.D. 2 2 0

Samuel Ferguson, Esq. . 1 1 0| Joseph Carson, Esq. F.T.C.D.2 2 0

R. C. Walker, Esq. .« - 1 1 0] The Archbishop of Dublin, 5 0 0

Rev. Cesar Otway, . 1 1 O| The President, : ah eee LO

*Messrs. Hodges and Smith, 4 4 0} George Kennedy,M.D. . 1 1 0
* Messrs. West, . - 5 5 O|}|} Rev. George S. Smith, 22 0
Rev. Professor Tilovt, 10 10 0} Rev. Dr. Drummond, 1 1 0

The Provost, T.C.D. - 5 5 O| J.S. Cooper, Esq. . 1 1 0

Rey. Dr. Wall, F.T.C.D.. 5 5 0O| M. Barrington, Esq. Ped 0

a The names are given in the order of subscription, according to the list kept by
Messrs. Hodges and Smith.

Arthur Hamilton, Esq.
William Edington, Esq.
Rey. Dr. Dickinson,
*Thomas Hutton, Esq. .
John Anster, LL.D.
*Robert Smith, M.D. .
Robert Ball, Esq.
Robert Mallet, Esq. .
F. W. Conway, Esq.
*Edward Clibborn, Esq.
Thomas Bergin, Esq. :
*Reyv. J. Malet, F.T.C.D. .
Thomas Beatty, M.D. é
Professor Butt, ‘
*James Fagan, Esq. . .
Professor Litton, M.D. .
*W. Torrens Mac Cullagh,.
Major Jones, . :
Professor Apjohn, M. D. F
Charies W. Hamilton, Esq.
John Hamilton, Esq.
R. P. Williams, Esq.
M. M. O’Grady, M. D.
Robert Kane, M. D.. :
Wm. Digges La Touche, Esq.
G. Carr, Esq. .
Rev. Dr. M‘Donnell, F. T. C. D.
A. Palmer, M.D.

(aR a Cp Oey eT rr eee enya ay

Ree ORM SE BNE eee EB OR eR ee ee ee ee ee ee 2

(WO)
Or
Or

i

George Pim, F'sq.
George Downes, Esq.
Joseph M. Ferrall, Esq.
J. F. Lynch, Esq. .
Jacob Owen, Esq. .
Thomas Grubb, Esq.

I. M. D’Olier, Esq. .

Charles T. Webber, Esq. .

Alexander Boyle, Esq.

Rev. Dr. Horner, .

Charles P. Croker, M.D.
*George Roe, Esq.

*Sir Philip Crampton, Bart.

Haliday Bruce, Esq.
*James Magee, Esq. .

J. W. Cusack, M.D..

J. A. Nicholson, Esq.

Richard Carmichael, Esq. .

*Daniel Nugent, Esq.

*Captain Battersbee, R.E. .

George James Knox, Esq.

The Dean of St. Patrick’s .

Captain Larcom, R.N.

Thomas Drummond, Esq.

Acheson Lyle, Esq. .
D. H. Kelly, Esq.
R. J. Graves, M.D. .

tu)

°

me eT ek eet Det et ND ete tt

a

————

pes on

ong uaceen ages

‘ytd Fé

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iy

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1839. No. 19.

November 11.
SIR Wo. R. HAMILTON, LL.D., President, in the Chair.

William Hill, Esq., and John A. Bowles, Esq., were
elected Members of the Academy.

Mr. Morrison, by permission of the Academy, read a
statement of the nature and objects of the Institute of Ar-
chitects of Ireland.

Resotvrp,—That the Academy has heard with pleasure
of the establishment of this institution, and shall be always
happy to learn the prosperity of an establishment connected
essentially with the progress of an art so important to the best
interests of society.

——_——

Mr. Ball read a paper “on the Bolina Hibernica,” by
Robert Patterson, Esq., Member of the Natural History
Society of Belfast.

In a note appended to his paper on the Cydippe Pomi-
formis, (Trans. R. I. A., vol. xix., part 1, page 96), the au-
thor had mentioned the occurrence on the Irish coast of a
species of ciliograde, which he had named provisionally Bo-
lina Hibernica. A large number having been taken in the bay

of Bangor, county of Down, on the 11th of July, 1839, the
Qi

358

drawings now brought forward were executed from living
specimens.

The movement of this Beroé was stated to be less viva-
cious than that of the Cydippe pomiformis, and it is much
more susceptible of external injury. The long-continued
action of certain portions of the cilia, after the animal was
broken to pieces, was mentioned ; the variety of aspect pre-
sented by the tentacula described ; and the situation of cer-
tain whitish cords or vessels minutely detailed. The lobes
of the mouth were shown by the figures not to occupy more
than one-fifth of the entire length. The body is transparent,
and, when agitated in the dark, becomes highly luminous—a
property not possessed after death.

In conclusion, the author enumerated the localities in
which it had been hitherto observed, and proposed some
brief specific characters by which it might be distinguished.

Rev. Dr. Dickinson gave a verbal account of a remark-
able waterspout, which he had observed at Killiney during
the last summer.

Towards the end of the month of July, about 10 a.™.,
while standing on the shore of the bay of Killiney, his at-
tention was directed by a friend to a waterspout, distant
about a quarter of a mile from the land. It was not similar
in form to the representations of waterspouts usually given,
and may therefore deserve to be noticed. It was shaped
like a double syphon, the whole being suspended at a con-
siderable elevation in the air ; the longer end of the syphon
reached towards the sea, and appeared to approach it
nearer and nearer, till, at length, its waters were distinctly
seen rushing into the deep. The loop gradually lowered, as
if sinking and lengthening by its own weight, while the up-
per part of the syphon seemed not to lose in elevation. At
length the loop burst, and there were three streams of water
pouring into the sea, two of those streams still continuing

359

united by the arch at the top. The breadth of these streams
gradually diminished till they became invisible, but their
length seemed undiminished as long as they were at all seen.
The quantity of water poured down must have been very
considerable, as the bubbling of the sea beneath could be
distinctly observed.

Dr. Dickinson was informed that a waterspout fell a few
days after inland, towards the Three-Rock mountain. It is
said to have done some injury ; but his informant did not see
it, and he could not, therefore, ascertain its shape.

DONATIONS.

Memoires de Ul Institut de France, Sciences Morales et Po-
litiques. Tom. II., Serie 2. Presented by the Institute.

Comptes Rendus Hebdomadaires des Seances de I Aca-
démie des Sciences. Par MM. les Secretaires Perpetuels.
Nos. 24 and 25. Premier Semestre, 1839; Nos. 1--19.
Deuxieme Semestre, 1839. Presented by the Academy.

Memoires de lV Académie Impériale des Sciences de St.
Petersbourg. Serie 6.

Sciences Mathematiques, §c. Tome IV., Liv. 1 et 2.

Sciences Politiques, §c. Tome IV., Liv. 1, 2, et 3.

Par Divers Savans. Tome IV., Liv. 1 et 2.

Recueil des Actes de l Académie Impériale des Sciences
de St. Petersbourg. 1837.

Presented by the Academy.

Memoires de la Societe Geologique de France. Tom. II.,
Partie 2, Presented by the Society.

Oversight over det Kongelige Danske Videnskabernes
Selskabs Forhandlinger og deis Medlemmers Arbeider i
Aaret. 1838.

Collectanea Meteorologica sub auspiciis Societatis Scienti-
arum Danice edita. 1889.

Presented by the Royal Society of Copenhagen.
212

360

Transactions of the American Philosophical Society,
1839. Vol. VI., Part 2. Presented by the Society.

Proceedings of the American Philosophical Society. No. 7.
Presented by the Society.

Journal of the Franklin Institute, for 1839. Vol. XXIII.
Presented by the Society.

Proceedings of the Royal Society, No. 39. Presented
by the Society.

Transactions of the Royal Society of Edinburgh. Vol.
XIV., Part 1.

Proceedings of the Royal Society of Edinburgh. Nos.
13, 14, and 15.

Presented by the Society.

Proceedings of the Botanical Society of London. Vol. 1.,
Part 1. Presented by the Society.

Proceedings of the Committee of Commerce and Agri-
culture of the Royal Asiatic Society. Presented by the
Society.

Transactions of the Royal Society of Literature. Vol.
III., Part 2. Presented by the Society.

Proceedings of the Numismatic Society of London, for
1837 and 1838. Presented by the Society.

Reports of the British Association for the Meetings held
in Dublin and Newcastle. Presented by the Association.

Ordnance Survey of Kildare. 42 Sheets, &c. Pre-
sented by his Excellency the Lord Lieutenant.

The second, fourth, and fifth Reports of the Commission-
ers for the Improvement of the Navigation of the Shannon.
4 Vols. Presented by the Secretary for Ireland.

A Manuscript, entitled “ Esquisse d'une Histoire primi-
tive des iles Britanniques.” By the Baron De Donop,
Hon. M.R.I.A. Presented by the Author.

On a new Species of Entomostraca. By F. M‘Coy, Esq.
Presented by the author.

361

Derrick’s Letters. Presented by Aquilla Smith, M.D.

A modern Irish Manuscript, containnmg Poems by John
O'Connell, Owen O’Rathaile, and others. Presented by the
Rey. Edward Marks.

A Review of Lyell’s “* Elements of Geology.” Presented
by Dr. Fitton.

Tracts on Docks and Commerce, §c. By Wm. Vaughan,
Esq., F.R.S. Presented by the author.

A Narrative of Captain D. Woodard’s Sufferings and
Escape from the Malays, §c. Presented by William
Vaughan, Esq.

Memoir of Nathaniel Bowditch, LL.D. By his son, N.
J. Bowditch, Esq. Presented by the author.

Report on the Magnetic Isoclinal and Isodynamic Lines
in the British Islands. Presented by the contributors.

The Herald of Peace. Nos. 1—7. Also, a Volume of
Tracts of the Peace Society. Presented by Joshua Abell,
Esq.

Sketch of the Geology of North America. By Charles
Daubeny, M.D., &c. Presented by the author.

Rara Mathematica. Edited by James Orchard Halliwell,
Esq., F.R.S., &c. Presented by the Editor.

Hlalliwell’s Hints to Novices in Manuscript Literature.
Presented by the author.

Dublin Metropolitan Police Report for 1838. Pre-
sented by the Commissioners of Police.

ANTIQUITIES PRESENTED.

The Lower Stone of an ancient Mill. Presented by
Arthur Hatfield, Esq.

A Bronze Belt, of a peculiar form. Presented by
Henry Watson, Esq.

An ancient Spear Head.

362

November 30 (Stated Meeting.)

SIR Wm. R. HAMILTON, LL.D., President, in the Chair.

Mr. Herrick presented to the Academy an ancient wooden
vessel, found at a considerable depth in Meenskehy bog,
near Mill-street, in the county of Cork. Mr. Herrick ob-
served that some gold ornaments, and a brazen spear head,
had been found some years ago in the same locality.

The thanks of the Academy were returned to Mr. Herrick
for his donation.

Mr. Ball read a paper “ on a Species of Loligo, found on
the Shore of Dublin Bay.”

After some general observations on the importance and
interest attached to the study of cephalopodous Mollusca,
the author proceeded to state, that about three years since
the subject of his paper was brought to him, with other
rejectamenta of the sea, collected after a storm, by his
friend, T. W. Warren, Esyg. Finding that it was not of a .
species recorded as British, he endeavoured in vain to trace
a description of it in foreign works; he therefore, but not
without hesitation, presumed it to be nondescript. Its di-
mensions are the following :—

Extreme length, to the end of tentacula, 10.0 inches.

Do. of the body or mantle, 3.1 Pe

Do. of the head, «: ©. <5, . ¥.6 re
Average length ofarms, . . . . . . 28 uy
Geneth of tentacula, yy.) 2.0830 Gwe OO, Vo as
Breadth of hny” Yipee. cere eet OU *¢
Length offin, . . . ewe GA eas Ska i8
Extreme breadth of bag, opine. 7) YL eee
Length of dorsallamina,. . . . + .3.5 4,

Extreme breadth of dorsallamina, . .0.2 ,,

363

Breadth of largest horny hoops of ace-
Prbulaspabout! y, < sits Ac< ooxin <wosdten «0! 2. inches:

Reference to the Diagrams.
1. Figure of Loligo Eblane, half the natural size.
2, Termination of tentacula, with acetabula, natural size.
8. Dorsal lamina, natural size.

4, Beak, natural size.

5, Magnified figure of an acetabulum, or sucker, to show
its peduncle.

6,7. Magnified figures of horny hoops of acetabula.

It was thus shown to be of much shorter proportions
than the Loligo vulgaris. Its body is urn-shaped. The large
fin, which is somewhat inequilateral, approximates to an
ellipse in form, and resembles not a little the fin of Loligo
Brongnartii, as figured by Ferussac, to which it also bears
likeness, in the structure of its five-ribbed dorsal lamina;
but it differs from this animal in its general proportions, and
in the horny hoops of its acetabula, which have in each of the

364

twelve largest in the tentacula about thirty-six sharp and
equal teeth. ‘The general form of the whole animal much re-
sembles Onychoteuthis Leachii—a cephalopod of a different
genus, with which it may be confounded by a casual observer.
Mr. Ball proposed to name the species Loligo Eblanz.*

In addition to the foregoing, the following species of
Loligo have fallen under Mr. Ball’s notice, as occurring in the
Irish seas :—

Loligo sagittata var. differing in the shortness of its ten-
tacula from the figure given by Ferussac. Several speci-
mens were taken off the coast of Cork by George Allman,
Esq.

Loligo vulgaris.

Loligo media.

Loligo media var.—easily distinguished by its greater
proportionate length of body, and by the shortness of its
tentacula, from the true L. media; in the form of the fin ter-
nating its mantle, it strongly resembles Loligo subulata. A
few specimens, obtained on the coast of Down by the late J.

Montgomery, Esq., were submitted to Mr. Ball’s inspection
by W. Thompson, Esq.+

_ Mr. Clarke read a paper “on atmospheric Electricity.”
The author commenced his paper with a description of
the apparatus which he had employed in the experimental
investigation of this subject. He showed the inapplicability
of the electrometers hitherto employed, and exhibited an

* The ancient name of Dublin.

t Since the foregoing was written, Mr. Ball was favoured with an inspection
of Cuttle-fish bones, found at different times on Magilligan Strand, county of Derry,
by Mr. Hyndman, of Belfast. They seem to be those of Sepia rupellaria, figured in
Ferussac’s third plate of Sepia. His attention was also directed to beaks of Cuttle-
fish, found in the stomachs of Delphinus melas and Hyperoodon bidens. They
belonged to a species of Cephalopod he has not yet determined. As he purposes
writing a monograph of the Cephalopoda of the Irish seas, he requests information
on the subject from all who can afford it.

a

365

highly insulated galvanometer, containing about three thou--
sand turns of very fine wire covered with silk, varnished
and baked,—which instrument, although exquisitely sen-
sitive to the feeblest voltaic electricity, was not at all acted
upon by atmospheric electricity of the low tension which
exists during serene weather in this country. Mr. Clarke
added, that although the application of such an instrument
would be a great desideratum in experiments on atmospheric
electricity, and in this point of view had been recommended
by the highest scientific authorities in Europe, yet he had
reason to think that it had never, in any country, been de-
flected by atmospheric electricity in serene weather.

The author then exhibited the electrometer which he
had devised for, and used in his experiments on this subject.
It consisted of a bell of glass, seven inches in diameter,
through the side of which passed a sliding graduated rod,
furnished with a vernier, which indicated the distance, in
hundredths of an inch, through which a single pendent slip
of leaf gold was attracted towards the rod which was in
connexion with the earth. The slip of leaf gold was attached
to a vertical and well insulated rod, which passed through a
collar of leathers, and could therefore be raised or depressed,
as required by the varying intensity, so that the lower end
of the leaf should always, when electrified, be a tangent
to the ball terminating the graduated rod.

The author then alluded to the received opinion, that the
Aurora Borealis is an electric discharge of considerable in-
tensity occurring near the polar regions, at great heights in
the atmosphere, where the air is necessarily rare, and where,
consequently, the electric light (as shown in our artificial
imitation of the phenomenon) must be very much diffused
and ramified. Hoping to throw light upon this subject,
he had made a series of observations on the electric intensity
of the twenty-four hours, commencing at mid-day on the 12th
of November, 1838, and continued at intervals of fifteen

306

minutes,—except during the appearance of the ‘Aurora,
when they were made every five minutes, and even oftener.
The results of these observations were laid down in a chart,
which exhibited the intensity of the electric fluid during
these twenty-four hours, a period including that of the mag-
nificent crimson Aurora, which was observed on the night
of the 12th, and morning of the 13th of November, 1838,
over every portion of the globe. It appeared, by this
chart, that the electric intensity during the existence of this
magnificent display of Auroral light was but little above the
mean electric intensity of that hour during the month; from
which the author inferred that this phenomenon, if at all
electric, occurred at such a distance as to be unable to affect
the apparatus.

The author then proceeded to give an account of the ex-
tended series of experiments which he had undertaken at the
recommendation of the Academy, and which he had continued
during twelve months, at intervals of fifteen minutes, during
at leastten days,and from three to seven nights in each month.
He stated, that when he had undertaken this series of expe-
riments, he had the following objects in view—namely, to
determine the mean amount of electric intensity existing in
this country, at the different hours of day and night, and
the periods of maxima and minima; and, secondly, to en-
deavour to trace the cause of this varying intensity to
the influence of some of the recognised agents in nature,—
such as the variations of atmospheric pressure; the vari-
ations of temperature ; or the varying quantity of vapour in
our atmosphere.

He was happy to announce, that he had not only deter-
mined the mean monthly, and annual force of electricity at
the several hours of the day and night, but also had succeeded
in establishing its dependence upon two, out of the three
agents, with which he had originally proposed to investigate
its connexion. The two with which he has established its

367

connexion and proved its dependence are, temperature, and
the total quantity of moisture present in the air, as shown by
the dew point. Indeed these two phenomena, as the author
remarked, are referribie to each other, the temperature pro-
ducing evaporation, and the force of electricity at any
period being shown to be almost exactly proportional to
the tension of the vapour so produced.

The hour of the first electric minimum was shown to
be about 3 a.M., the electricity increasing with the tem-
perature until 10 a.m., when a slight decrease occurred ;
the electric tension again commences rising at about 11 a. M.;
and continues to increase until about 2" 45™, Pp. m.—all
these movements being in exact proportion to the elevation
of the dew point and temperature. At 3 p.m. the dew point
and temperature begin gradually to lower, as does also the
electricity (but not so quickly); but from 5 to 7 p.., the
electric intensity rises, being acted upon and increased by
the precipitation of the evening dew, which has set free the
latent electricity of the condensed vapour, in conformity
with the experiment of Volta. Again, from 7 p. M., the
electric intensity weakens rapidly, and descends in common
with the dew point and temperature, until they all reach their
minimum about 3 a.m.

Thus the patient investigation of this subject has laid
bare the cause of the varying diurnal intensity of the elec-
tric fluid,—showing it to be the result of evaporation, which,
besides its agency in carrying the electric fluid from our
earth to the upper regions of the air, daily returns it to us
by the conducting power of this vapour, in the direct pro-
portion of its quantity.

Dr. Smith read a paper ‘‘on the Irish Coins of Ed-
ward the Fourth,” the chief object of which was to endea-
vour to fix the dates of the numerous coinages of this reign
with more precision than had been attained before.

568

The coins were divided into four sections, each distin-
guished by its peculiar type,—the Irish, the Anglo-Irish, the
English, and the coins with three crowns on the reverse.

In the first section the author pointed out the distinc-
tions not previously recognised, between the groats and
the pennies of Henry the Sixth, and those of Edward the
Fourth, and showed that some of Edward’s coins have been
heretofore erroneously appropriated to Henry the Sixth.

In the second section proofs were adduced in corrobo-
ration of Mr. Lindsay’s opinion concerning the date (1465)
of the coins engraved in Snelling’s Supplement to Simon,
Pl. I. Figs. 18, 19, and also that the coinage of 1467 was
erroneously described by Simon as having “ a crown on one
side,” instead of “a face and crown.” Two unpublished and
unique specimens of this coinage were described,—the
double groat of Drogheda, the earliest com known from this
mint, in the cabinet of the Rev. Mr. Butler of Trim; and
the half groat of Trim, in the cabinet of the Dean of St. Pa-
trick’s, Some remarks were made on the difference between
the Tower and the Troy pound, which have been frequently
confounded by the writers on Irish coins. _

The coins with the King’s head on the obverse, and a
rose, instead of pellets, in the centre of the reverse, Dr.
Smith considers to have been coined in 1470; and he sup-
ported his opinion by reference to the Act of the first of
Richard the Third, and by other evidence.

In the third section, two unpublished and unique coins
were described ,—the half groat of Drogheda, in the Dean of
St. Patrick’s cabinet ; and the half groat of Trim, in that of the
Rev. Mr. Butler ;—and some reasons were assigned to show
that the letter G, which is found on most of the groats of
Drogheda, Dublin, and Waterford, was the initial of Ger-
myn Lynch, the master of the mint.

In the fourth section Dr. Smith remarked that Sir James
Ware, or the writers since his time, had not given any ex-

369

planation of the meaning of the term “ cross-keele groats;”
and stated his opinion that it was the Irish word cpoé caol,
(cross-keale, or slender cross,) and that it was applied by
the native Irish to distinguish the groats of this period from
the other kinds with a broader cross, which were in circula-
tion. There are many instances of coins being denominated
from some peculiarity of their type, e.g. Angel, Salute,
Harpers, Sc.

Many other points of interest to numismatists were fully
considered in this communication, and accurate drawings of
the coins described were exhibited.

Dr. Apjohn read a note by George J. Knox, Esq., “on
the oxidating Power of Glass for Metals, and on the want
of Transparency in ancient Glass.”

‘In alate work, which treats of the manufacture of glass,
an experiment of Guyton Morveau is mentioned, in which
six per cent. of copper filings having been mixed with
pounded glass, and the compound completely melted, it was
found to have assumed a red colour uniformly diffused
throughout the mass, so deep as to render the glass nearly
opaque. The experiment originated from a workman in the
glasshouse having dipped a heated copper ladle into a pot
of fused glass. The copper ladle was melted ; the casting
and annealing of the plates were proceeded with as usual ;
and on their completion the workmen were surprised to find,
that not only were grains of metallic copper embedded in
the substance of the glass, but bands uniformly coloured of
a fine bright red, were distributed throughout the mass.

“The experiment of Guyton Morveau, being but a repe-
tition of the accidental one made by the workman, seems to
have but little engaged his attention, the colour being con-
ceived to be due to an imperfect state of oxidation, as oxide
of copper imparts to glass a greenish colour.

«Tt appeared to me, at first sight, that the red colour was

370

due to the actual solution of the copper in the metallic state,
the globules of copper imbedded in the mass having been
deposited from a state of solution, upon cooling. To deter-
mine this, I mixed in different proportions with powdered
glass, iron, lead, copper, silver, bismuth, antimony, tin, gold,
platinum, in a minute state of division; and found that glass,
when mixed with iron filings, will oxidate and dissolve
almost as much iron, when mixed with it in the metallic state,
as if it were mixed with it in the state of oxide. Of
copper, only a small proportion is oxidated and dis-
solved, imparting a green colour to the glass, while the rest
remains disseminated throughout the glass in globules of
copper and red streaks, which are probably the protoxide ;
whereas lead (for whose oxide glass has such a strong
affinity) oxidates but a small portion, when mixed with it in
the metallic state, the rest being found imbedded in globules
throughout its mass. Tin, antimony, and bismuth are more
easily oxidized and dissolved than lead. Gold, when fused
with glass, imparts to it a light greenish tinge, increasing in
depth with the relative proportion of silica in the glass,—pro-
ducing a deeper colour with the bisilicate than the silicate of
potash, and still deeper when German glass (which contains a
large proportion of silica) is employed ; globules of gold are
found (as in the analogous cases of lead and copper) dissemi-
nated throughout the mass. If the heat be increased, and
the crucible containing the gold be left for some hours in the
furnace, the glass assumes a pinkish hue, which is the colour
imparted to it by the protoxide of gold. When platinum
sponge is fused with glass, it sinks to the bottom of the cru-
cible unaltered, owing to its infusibility. When charcoal is
heated with glass, a large proportion is oxidated, the remain-
der presenting the appearance of a mechanical mixture.
‘*From these experiments it appears that glass, at high tem-
peratures, not only has the property of oxidating the metals,
and forming a chemical compound with the oxide, but

371

moreover, when the chemical affinity is satisfied, of dissolving
the oxides, and probably the metals themselves when in a
state of fusion; the latter, on the cooling of the glass,
being deposited in globules throughout its interstices, (at
least the appearance presented by the glass seems to favour
such an opinion.)

* The colours produced by the fusion of metals with glass,
being different in many cases from those obtained when their
oxides were employed, and presenting the dull untransparent
appearance which is so remarkable in ancient glass, led me
to suppose that the ancients did not employ any colouring mat-
ter unknown at the present day, but that, being unacquainted
with the mineral acids, they employed the metals either in
the metallic state, in filings, or else in an imperfect state of
oxidation. To determine the probability of this conjecture,
I selected three specimens of mosaic glass, analyzed by
Klaproth ; and substituting for the oxides, in the same rela-
tive proportion, the metals in a minute state of division, I
obtained coloured glasses of nearly the same colour as
the mosaics, while the colours produced when the oxides
were employed were not only perfectly different, but the
glasses were clear and transparent.

“* One of a lively copper red, opaque and very bright,
contained, in 200 grains, silica 142, oxide lead 28, copper
15, iron 2, alumina 5, lime 3.

“ Another, of alight verdigris green, contained, in 200
grains, silica 130, oxide copper 20, lead 15, iron 7, lime
13, alumina 11.

“* A specimen of blue glass contained, in 200 grains, silica
163, oxide iron 19, oxide copper I, alumina 3, lime 4.”

The Secretary read a note by George J. Knox, Esq.,
** on a gaseous Compound of Fluorine and Cyanogen.”

When recently ignited fluoride of silver is mixed with
several times its weight of dry solid cyanogen, and heated

372

in a platinum crucible, which fits to one extremity of a
platinum tube, to the other extremity of which is adapted
a small platinum receiver, (the junction between the
latter being rendered air-tight with caoutchouc, and the
receiver and tube being immersed in a freezing mixture of
ice and snow,) no solid or liquid product is obtained in the
tube or receiver; the fluoride of silver is converted into-
cyanuret of silver; and a gas is evolved, which has a
stronger effect upon the eyes and throat than hydrofluoric
acid, producing sickness, headache, and vertigo. This gas
acts strongly upon glass, reddens litmus, and burns in the
flame of a spirit lamp with a yellowish light. It remains
for a considerable time in the platinum vessel, showing that
its specific gravity is greater than that of atmospheric air.

The same gas is obtained, when a current of gaseous
cyanogen is passed over fluoride of silver fused in the pla-
tinum tube.

PROCEEDINGS

or

THE ROYAL IRISH ACADEMY,

1839. No. 20.

December 9.

SIR Wa. R. HAMILTON, LL.D., President, in the Chaiv.

Mr. Clarke read a supplement to his paper *‘ on Atmos-
pheric Electricity.”

The author gave in this supplement a more detailed
description than he had before done of the mode of insu-
lating the apparatus for experiments on atmospheric elec-
tricity, which he had used in the course of his recent
researches.

He then described an experiment by which he had
shown the absence of decomposing agency in the electricity
of serene weather, and stated his opinion of the cause.

Mr. Clarke next directed attention to the fact, that the
curve representing the diurnal variation of the barometric
column was the reverse of the electric, thermometric, and
hygrometric curves. He considered that such a result was
to be expected; for the barometric column should naturally
be lower from mid-day to 3 P.M. than at midnight, in conse-
quence of the greater quantity of aqueous vapour which ex-
ists in the atmosphere at the former than at the latter
time,—air charged with aqueous vapour being known to be

2%

374

of less specific gravity than dry air. Thus the barometric
and hygrometric curves would be the inverse of each other,
the maxima of the one corresponding to the minima of the
other; and as the author had previously shown that the
hygrometric, thermometric, and electrometric curves were
in accordance, the barometric curve would be the inverse
of the thermometric and electrometric curves also. The
author remarked, that if this character of the horary oscil-
lations of the barometer in Ireland be confirmed by the ex-
periments of other observers, it will either lead to new
views -of this phenomenon generally, or show that the
quantity of aqueous vapour existing in Ireland is so great
as to cause the horary barometric oscillations to present
themselves in a different form from that in which they are
recognised in drier climates.

The author adverted, in the last place, to the hypothesis
of Priestley and Beccaria,—that the upper regions of our
atmosphere were the chief depositories of the electric fluid,—
an opinion which he conceived must fall, if the origin of
atmospheric electricity be due (as his experiments prove) to
the existence of vapour; as these elevated parts of our at-
mosphere are far above the region of permanent vapour,
or even of vapour at all.

Professor Mac Cullagh read a paper “ on the Dynamical
Theory of crystalline Reflexion and Refraction.”

In a former paper, presented to the Academy in January
1837, and printed in volume xviii. of the Transactions, the
author had reduced all the complicated phenomena of
reflexion and refraction at the surfaces of crystals to the
utmost regularity and order, by means of a simple rule,
comprised in his theorem of the polar plane. This rule,
which was verified by its agreement with exact experi-
ments, he had deduced from a set of hypotheses relative to
the vibrations of light in their passage through a given

—— se

375

medium, and out of one medium into another ; but he had
not attempted to account for his hypotheses, nor to connect
them together by any known principles of mechanics ; and
the only evidence in favour of their truth, was the truth
of the results to which they led. He had observed, how-
ever, that these hypotheses were not independent of each
other ; he had ascertained that the laws of reflexion at the
surface of a crystal were connected with the laws of propa-
gation in its interior ; and he had thence been led to con-
clude that all these laws and hypotheses “ had a common
source in other and more intimate laws not yet discovered.”
He became impressed, in short, with the idea “ that the
next step in physical optics would lead to those higher and
more elementary principles by which the laws of reflexion
and the laws of propagation are linked together as parts of
the same system.”

This step the author has now made ; and the present
paper realises the anticipations scattered through the for-
mer. Setting out with the general dynamical theorem
expressed by the ons

VSS dadydz o& te iE nm 5, + ae i) = dxdydz8v, (1)

where &, , 2, are the displacements at the time ¢ of a par-
ticle whose co-ordinates are x,y, %, and where the density
of the ether is supposed to be unity, as being constant for
all media, the author determines the form of the function Vv,
for the particular case of luminiferous vibrations, by means
of the property which may be regarded as distinguishing
them from all others—namely, that they take place entirely
in the surface of the wave. From this property he shows,
in the first place, that v is a function of the three dif-
ferences

dy d& a dé d&_ adn.

dz dy’ du dz’ dy dx’
2K2

376

_and, in the next place, that the only part of it which comes
into play is of the second order, containing the squares and
products of those quantities, with of course six constant
coefficients. Then, supposing the axes of coordinates to
be changed, he proves that the usual formule for the trans-
formation of coordinates apply also to the transformation
of those differences ; so that, by assuming the new axes
properly, the terms in the function v which depend on the
products of the differences may be made to vanish, and v
will then contain only the three squares, each multiplied
by a constant coefficient. The axes of coordinates in this
position are defined to be the principal axes, (commonly
called the axes of elasticity); and when we put, with

reference to these axes,

dn de\, dg dé d& dy
ava a (7 al gia at aay ZL)? @
it turns out that a, b,c, are the three principal velocities of
propagation within the crystal.

To find the laws of propagation in a continuous medium
of indefinite extent, we have only to take the variation of
v from the expression (2), and, after substituting it m the
right-hand member of equation (1), to integrate by parts,
so as to get rid of the differential coefficients of the varia-
tions 0, dn, 6¢. Then equating the quantities by which
these variations are respectively multiplied in the triple
integrals on each side of the equation, we obtain the value
of the force acting on each particle in directions parallel to
the principal axes. The double integrals which remain on
the right-hand side of the equation are to be neglected, as
they belong to the limits which are infinitely distant. ‘The
resolved values of the force thus obtained lead to the pre-
cise laws of double refraction which were discovered by
Fresnel, with this difference only, that the vibrations come
out to be parallel to the plane of polarisation, whereas he
' supposed them to be perpendicular to it.

377

When there are two contiguous media, and the light
passes out of one into the other, suppose out of an ordinary
into an extraordinary one, and we wish to determine the
laws of the reflected and refracted vibrations, it is only
necessary to attend to the double integrals in the equation
of limits ; but the integrations must now be performed
with respect to other coordinates. Taking the separating
surface of the two media for the new plane of zy, the axis
of x being in the plane of incidence, let the principal axis
x of the crystal make with these new axes the angles
a, 8, y, while the principal axes y and <, in like manner,
make with them the angles a’, [3’, y’, anda”, 3”, y”, res-
pectively. Then, marking with accents the quantities
relative to the new coordinates, we have

aha aC we eo su + (%,— ©) cos 8

dz dy” \dz dy’ |
+ (5 - 1) cos y; |
£-£-(8- Seer E-Beme |
+ (F-2) cos y’; i.
SO = (BF) cova! + (T+ 7) cos 8" |
+ (Go ae) esr! |

Now if we take the variations of these expressions, and
substitute them in the value of dv derived from equation
(2), then multiply by da‘dy'dz’, and integrate between the
limits x’ = 0 and 2’= @, neglecting to take account of the
latter limit, as well as of the integrations with respect to
a and 7’, of which both the limits are infinite, we shall get,
in the equation which holds at the separating surface, a
term of the form

378

§§ dx’dy’' (ad — Péy’), (4)

where

se @ ay F) cos a + 6° Agee = cos a’

é
|
ie
Bia. (G-Z) «0 sB+B 2 =) oe | (5)
|

+¢ (F- I cos (3”.
This term, along with a similar but simpler one arising
from the ordinary medium, must be equal to zero ; and as
the variations 6&’ and én’ are independent, this condition
is equivalent to two. Moreover, the quantities &’ and 1
are to be put equal to the corresponding quantities in the
other medium, and thus we have two more conditions,
which are all that are necessary for the solution of the
problem.

The four conditions may be stated by saying, that each
of the quantities P, Q, &’, n’ retains its value in passing out
of one medium into another. Hence it is easy to show
that the vis viva is preserved, and that 2’ likewise retains
its value. These two consequences were used as hypotheses
by the author in his former paper, and accordingly all the
conclusions which he has drawn in that paper will follow
from the present theory also.

It will be perceived that this theory employs the general
processes of analytical mechanics, as delivered by Lagrange.
The first attempt to treat the subject of reflexion and re-
fraction in this manner was made by Mr. Green, in a very
remarkable paper, printed in the Cambridge Transactions,
vol. vii. part 1. After stating the dynamical principle
expressed by equation (1), (though with a different hypo-
thesis respecting the density of the ether,) Mr. Green ob-

379

serves, that, supposing the functionv to be known, “ we
can immediately apply the general method given in the Mé-
canique Analytique, and which appears to be more especially
applicable to problems that relate to the motions of systems
composed of an immense number of particles mutually acting
upon each other.” Such is certainly the great advantage of
starting with that general principle; but the chief difficulty
attending it, namely, the determination of the function v, on
which the success of the investigation essentially depends, has
not been surmounted by Mr. Green, who has consequently
been led to very erroneous results, even in the simple case
of uncrystallized media, to which his researches are exclu-
sively confined. In this case Mr. Mac Cullagh’s theory
confirms the well-known formule of Fresnel, one of which
Mr. Green conceives to be inaccurate, and proposes to
replace by a result of his own, which, however, will not
bear to be tested numerically. The present theory applies
with equal facility to all media, whether crystallized or not,
and is distinguished throughout by the singular elegance
and simplicity of its analytical details ; a circumstance which
the author regards as a strong indication of its truth.

Mr. Lloyd exhibited to the meeting a specimen of a re-
markable substance recently found in the principality of
Carolath, in Silesia. It formed part of a cloth of 200 square
feet in surface now in the possession of the King of Prussia.
No description of this substance has yet been published; but
Major Sabine and Mr. Lloyd were informed by Baron Hum-
boldt (by whom the present specimen was kindly given) that
M. Ehrenberg had examined it microscopically, and had
found it to be an organic substance, consisting partly of ve-
getable and partly of animal matter ;—the vegetable compo-
nent being the conferva rivularis, the animal different species
of Infusoria, of the family known by the name of Bacillaria.

To illustrate the origin of this substance, Mr. Lloyd.

380

read the following note from Major Sabine, respecting a
similar body which has been examined and described by
M. Ehrenberg. ,

“In the year 1686, some workmen who had been fetch-
ing water from a pond seven German miles from Memel,
on returning to their work after dinner, (during which there
had been a snow storm,) found the flat ground around
the pond covered with a coal-black, leafy, or paper-like
mass; and a person, who lived near, said he had seen it
fall like flakes with the snow. On examination, some of
the pieces were found to be as large.as a table, and were
lying upon each other to the depth of the thickness of a
finger. The mass was damp and smelt disagreeably, like
rotten seaweed ; but when dried the smell went off. It tore
fibrously like paper. Specimens were preserved in several
collections, where it was known by the name of Meteor-paper,
and by many was actually supposed to be a meteoric body.
It has been recently examined by M. Ehrenberg, and found
to consist partly of vegetable matter, chiefly conferva cris-
pata, (common in Germany,) and partly of infusoria, of
which M. Ehrenberg was able to recognise twenty-nine
species. Of these, eight species have siliceous coverings,
but the others, which are equally well preserved, were
soft-skinned animals; most of them are known as species
now existing.

“«‘ The Meteor-paper, therefore, as it has been called, was
formed in marshy places; had been raised into the air by
storms of wind ; and had again fallen.

‘Substances of the same nature have been found in Nor-
way, in Silesia, and in the Erz Mountains. In some instances
they are described as leathery; in others as resembling wad-
ding, and being white on the upper side and green beneath.
They have probably all a similar origin.”

Mr. Lloyd also laid on the table of the Academy a spe-
cimen of a very similar substance, which he had received

381

from Sir John Herschel, and which was found investing the
rocks at the mouth of one of the rivers of Southern Africa.
It resembles the other very much in external appearance,
except that the fibres are coarser, and more compactly mat-
ted together. It appears to consist almost entirely of con-
ferve, but apparently of a different species.

A paper was read by Mr. J. Huband Smith, descriptive
of certain porcelain seals, amounting to upwards of a dozen,
found in Ireland within the last six or seven years, and in
places very distant from each other.

He exhibited to the Academy one of these seals, with
impressions of several others in sealing-wax. He stated
that they were all uniform, consisting of an exact cube,
having, by way of handle, some animal (probably an ape)
seated upon it ; and that they were se precisely similar in size
and general appearance as to be undistinguishable, except
by the characters on the under surface. Little is known
respecting these seals beyond the mere fact of their having
been found in this country.

An extract from the Chinese grammar of Abel-Rémusat
showed that the inscriptions on these seals are those of
a very ancient class of Chinese characters, “in use since
the time of Confucius,” who is supposed to have flourished
“in the middle of the sixth century, before J.C.” The
remote period to which these characters are assigned, leaves
open a wide field for conjecture as to the time in which these
porcelain seals found their way into this country.

The situations in which some of them have been found are
remarkable. One was discovered in ploughing a field near
Burrisokane, county of Tipperary, in 1832; another wasfound
last year at Killead, in the county of Down; another in the
bed of the river Boyne, nearClonard, in the county of Meath,
in raising gravel; and a fourth was discovered many years
ago at a short distance from Dublin.

382

From the extreme degree of heat to which they appear
to have been subjected, and the consequent vitrification
which has in some measure taken place, they are quite as ca-
pable of resisting the attacks of time as the glass and porcelain
deities and ornaments found in the mummy cases of Egypt,
and may have lain for an indefinite period beneath the sur-
face of the earth. It is therefore, at least, possible that they
may have arrived hither from the East, along with the wea-
pons, ornaments, and other articles of commerce, which were
brought to these islands by the ships of the great merchant-
princes of antiquity, the Phoenicians, to whom our ports and
harbours were well known.

Mr. Smith then called the attention of the Academy to
the remarkable discovery, by Rosellini, Lord Prudhoe, and
other recent traveilers, of unquestionable Chinese vases in
the tombs of Egypt. He read a passage from Davis’s China,
in which some of them were described; and also an ex-
tract from Wilkinson’s Ancient Egyptians, from which it
appeared that the number of Chinese vases found at Coptos,
Thebes, and elsewhere, amounted to seven or eight, and that
the inscriptions on them had been translated by Chinese
scholars to mean, ‘‘ The flower opens, and lo! another year,”
being a line from an ancient Chinese poem.

From this the trade of China with distant countries, at a
period of the remotest antiquity, being clearly proved, Mr.
Smith submitted to the Academy that a case of strong pro-
bability had been made out, that the porcelain seals found
their way into Ireland at some very distant period. In fact,
if they be not of modern introduction into this country—a
supposition which the situations in which several of them have
been found seems utterly to preclude—their arrival hore
must of necessity have been most ancient.

Mr. Petrie read a paper “on ancient Seals of Irish
Chiefs, and Persons of inferior Rank,” preserved in the col-,

383

lections of Irish Antiquities formed by the Dean of St. Pa-
trick’s, and by himself. He observed that this class of anti-
quities had been but little attended to by Irish antiquaries—
a circumstance which he attributed to the want of general
collections of our national antiquities till a recent period : and
hence, if the question had been asked a short time since,
whether the Irish had the use of signets generally amongst
them or not, it would have been impossible to give a decisive
answer. ‘This question, however, can now be answered in
the affirmative; but the period at which the use of seals
commenced in Ireland is stil! uncertain, as no Irish seals
anterior to the Anglo-Norman invasion have been found ;
or, if found, their discovery has not been recorded. As,
however, it is now certain that seals were used by the
Anglo-Saxons, it is not improbable that their use may have
been introduced into Ireland also—more especially as a re-
markable similarity prevailed between the two countries in
customs and in knowledge of the arts.

The Irish seals hitherto discovered are similar in style
and device to the cotemporary seals of the Anglo-Normans
of similar ranks ; and, like the secular seals of the latter, are
usually of a circular form, whilst the ecclesiastical seals are
usually oval.

The seals which Mr. Petrie described or exhibited to the
meeting were as follows :—

1. A drawing of an impression from the seal of Felim
O’Conor, King of Connaught, as published by Sir James
Ware. The device exhibits the figure of Felim on horse-
back, charging with sword in hand, and the legend reads,

‘Ss, FEDHLIM, REGIS CONACTIZ.”

This prince died in 1265.

2. The seal of Donald Og, the son of Donald Roe
Mac Carthy, King or Prince of Desmond, who died in 1309.
The device is similar to that of the preceding, and the le-
gend reads,

384

‘6s, DONALDI OG FILI. D. ROGH MAC CARTHY.”

This seal is in the collection of the author.

3. The seal of Mac Con, Chief of Hy-Caissin, a territory
in Thomond, possessed by the family of Macnamara. He
died about the year 1350. The device of this seal is also
similar to that of Felim, and the legend reads,

‘© S, MICON DUCIS DE IV. CASSIN.”

This seal is in the collection of the Dean of St. Patrick’s.

4, The seal of Brian O’Brian, Prince of Thomond, who
was killed in the year 1350. The device is a griffin, which
appears to have been the heraldic badge of the O’Briens at
this period ; and the legend reads,

‘6S. BRIAN I BRIAN.”

This seal is also in the collection of the Dean of St. Patrick’s.

5. The seal of Murtagh O’Neill, who, as Mr. Petrie be-
lieves, was the Lord of Clannaboy of this name, whose death
is recorded by the Irish annalists at the year 1471. The
device is the bloody hand of O’Neill, and the legend reads,

‘©S. MAURITIUS UI NIELL.”
This seal is also in the collection of the Dean of St. Patrick’s.

6. The seal of Mac Craith, the son of O’Dafid. The de-
vice is a non-descript animal, and the legend reads,

‘6 S| MAC CRAITH MACI DAFID.”

This seal, which is of the early part of the fourteenth cen-
tury, appears to belong to the O’Daffy’s, a family of the Dal
Cais in Thomond, still in existence. ‘The seal is in the col-
lection of the author.

7. The seal of Brian O’Harny, chief of an ancient family
in Kerry. The device exhibits the helmeted head of a war-
rior, cut on a cornelian, and the legend reads,

‘° S| BRIAN O HARNY.”

This seal is in the collection of the Dean of St. Patrick’s.
The material of all- these seals is silver.

389

January 13, 1840.
SIR Wm. R. HAMILTON, LL. D., President, in the Chair.

Sir Philip Crampton, Bart., William J. Lloyd, Esq.,
and John Mollan, M. D. were elected members of the
Academy.

Professor Mac Cullagh made a communication respecting
the optical Laws of Rock-crystal (Quartz).

In a paper read to the Academy in February 1836, and
published in the Transactions, (vol. xvii. p. 461,) he had
shown how the peculiar properties of that crystal might be
explained, by adding, to the usual equations of vibratory
motion, certain terms depending on differential coefficients
of the third order, and containing only one new constant c.
This hypothesis, which was very simple in itself, not only
involved as consequences all the laws that were previously
known, but led to the discovery of a new one—the law,
namely, by which the ellipticity of the vibrations depends
on the direction of the ray within the crystal. He was not
able, however, to account for his hypothesis, nor has it
since been accounted for by any one.

But the theory developed in the paper which he read at
the last meeting of the Academy, now enables him to assign,
with a high degree of probability, the origin of the addi-
tional terms above-mentioned, and, if not to account for
them mechanically, at least to advance a step higher in the
inquiry. In that theory it was supposed, (and the sup-
position holds good in all known crystals, except quartz,)
that the molecules of the ether vibrate in right lines, the
displacements remaining always parallel to each other as the
wave is propagated ; and it was shown that the function v,
by which the motion is determined, then depends only on
the relative displacements of the molecules. But when this

386

is not the case,—when, as in quartz, each molecule is sup-
posed to vibrate in a curve—then it is natural to conceive
that the function v may depend, not only on the relative
displacements, but also on the relative areas which each
molecule describes about every other more or less advanced
in its vibration. This idea, analytically expressed, intro-
duces a new term v into the value of the function 2v; and,
if the plane of the wave be taken for the plane of zy, it is
easy to show that
=o (ine _ a
~~ \dz ds? dz dz*/"
Now if we integrate by parts the expression

(SS dadydzsv,

so as to get rid of the variations of differential coefficients,
the reduced form of the triple integral will be

3. 3
2c §§§ dedydy ($4 36 — ae 3)

dz°
from which it appears that the quantities
dn BE
es SRE

are to be added to the usual expressions for the force in the
directions of x and y respectively. These are the very
terms in the addition of which the hypothesis before alluded
to consists.

The Secretary read a paper-by James Orchard Halliwell,
Esq. F.R.S., &c., entitled ‘‘ an Inquiry into the Period of
the first Use of the Zero by those Writers who adopted the
Notation of the Boetian numerical Contractions.”

The author referred, at the commencement of this com-
munication, to the opinion which he had formerly expressed
on the nature of the change from the use of the abacus, to
that of local position, and the cipher. This opinion is con-

tained in the following extract: “It would be impossible,
with the few materials yet brought to light, to conjecture with
any great probability, how far these Boetian contractions may
have influenced the introduction, or cooperated with the
Arabic system, to the formation of our present numerical no-
tation. It appears to me highly probable that the two sys-
tems became united; because the middle age forms of the
figure five coincide with the Boetian mark for the same
numeral, and those of two others are very similar. The idea
of local position, again, may have had an independent
European origin; the inconveniences of the abacus on paper
would have suggested it by destroying the distinguishing
boundaries, and inventing an arbitrary hieroglyphic for the
representation of an empty square.”

The author then proceeded to adduce evidence from some
documents recently discovered in support of these views. He
showed from the Mentz MS. in the Arundel collection, in
what manner the mode of operation with the abacus had
been improved, so as to lead naturally to the present system.
He then brought forward some passages from MSS. illustra-
tive of the first employment of the zero; and concluded by ,
adducing an instance from a MS. of the translation of Euclid
by Athelard, of the fourteenth century, belonging to the
Arundel collection, in which the number 15 is written in
these contractions, and without a division.

DONATIONS.

Catalogue des Principales Apparitions des eloiles filantes.
Par A. Quetelet.

Sur Vetat du Magnétisme Terrestre a Bruxelles, pendant
les douze années de 1827 a 1839. Par A. Quetelet.

Sur la Longitude de ? Observatoire Royal de Bruxelles.
Par A. Quetelet.

Presented by the Author.

Asiatic Researches. Vol. XX., Part 2. Presented by
the Asiatic Society of Bengal.

388

The American Almanac for 1840. Presented by the
American Philosophical Society.

Comptes Rendus Hebdomadaires des Séances de UV Aca-
démie des Sciences. Par MM. les Secretaires Perpetuels.
Nos. 20-26. Deuxiéme Semestre. 1839. Presented by
the Academy.

Transits and Calculations of apparent right Ascensions.
1834.

Zenith Distances observed with the Mural Circle, and
Calculations of Geocentric South Polar Distances. 1836 and
1837.

Declinations of the principal fixed Stars, deduced from
Observations made at the Observatory, Cape of Good Hope.
By Thomas Henderson, Esq.

Observations of Halley's Comet, made at the Royal Ob-
servatory, Cape of Good Hope.

Bessel’s Refraction Tables.

Presented by the Lords Commissioners of the Admiralty.

By-Laws of the Institute of Architects of Ireland. Pre-
sented by the Society.

The Mahawanso, with Translation in English. By the
Hon. George Turnour, Esq. Presented by F. B. Norris,
Esq., Surveyor General of Ceylon, per I. S. Cooper, Esq.

Medical Report of the Fever Hospital, for 1837-1838.
Presented by G. A. Kennedy, M.D.

The Dublin Penny Journal. Nos. 67, 104, Vol. If.; Nos.
191, 198, Vol. IV. Presented by P. Dixon Hardy, Esq.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1840. No. 21.

January 27.
SIR Ws. R. HAMILTON, LL.D., President, in the Chair.

Mr. Otway read a letter from the Rev. J. D’Arcy Sirr,
on the ruins of the Abbey of Cong, in the county of Mayo.

Mr. Otway then read the first part of a paper “ on the
Antiquarian Remains of the North-west of Ireland.”

ResotveD,—(on the recommendation of Council,) that
the conditions required previous to the ballot for new Mem-
bers be all complied with at least one week before such
ballot.

ReEsoLvED,—(on the recommendation of Council,) to in-
sert the words ‘‘ ipso facto,” in chap. iv. sect. 3, of By-laws,
previous to the words “‘ be excluded the Academy.”

DONATIONS.

An ancient Irish Hand-mill, or Quern. Presented by
Joseph Huband Smith, Esq.

Theology and Metaphysics of Scripture. By Andrew
Carmichael, Esq. Presented by the Author.

21

390

February 10.
SIR Wn. R. HAMILTON, LL.D., President, in the Chair.

Rev. Maurice M‘Kay, LL.D., Frederick W. Burton,
Esq. R.H.A., Joseph Napier, Esg., and Thomas Hutton,
Esq. F.G.S., were elected Members of the Academy.

ReEsotveD,—To empower the Council, to prepare an
Address of congratulation to Her Majesty, on the occasion
of her marriage, and to affix the seal of the Academy
thereto.

The Academy adjourned.

February 24.
SIR Ws. R. HAMILTON, LL.D., President, in the Chair.

J. Huband Smith, Esq. read a paper “ on the different
kinds of Querns used by the Irish.”

Having lately presented to the Academy, as a contri-
bution to their collection of Irish Antiquities, an oblong
quern, or corn-mill, of the most primitive form, Mr. Smith
now offered some few remarks on this very ancient article of
housewifery.

The circular or rotatory quern, the parent of the modern
millstones, is well known to antiquarians; but the still
earlier and ruder hand-mill of an oblong form, (and which,
therefore, must have been used in a very slow and laborious
process, by pushing the upper stone backwards and for-
wards upon the under,) does not appear to have been
hitherto noticed, being, in fact, very rarely met with ; while
the round quern is of comparatively common occurrence.

391

The word “quern” comes directly from the Saxon or
Teutonic name, with which it is identical. Another simple
and domestic machine, the churn, derives its appellation
doubtless from the same root; the office of both being to
separate,—in the one instance, the meal from the husk, and
in the other, the butter from the milk. It seems more than
probable that the Latin verb “ cerno,” whose primary mean-
ing is to separate or divide, took its rise from the cperation
of these very primitive implements of domestic economy.
The approximation in sound will be apparent, if we pro-
nounce the Latin letter ¢ hard, as some scholars maintain we
should do.

In the Celtic language the quern is denominated “ Bro,”
and inthe Welsh or British, ‘‘ Breyan;” both words having
the same origin as the old French verb “ Broyer,” from
which we derive a verb not in very general use, but yet to
be found in a work of standard authority, the English
translation of the Scriptures, where, as it will be observed,
it is met in conjunction with the operation of reducing
corn to meal: ‘* Though thou shouldest bray a fool ina mor-
tar among wheat with a pestle, yet will not his foolishness
depart from him.” One very ancient form of quern ap-
proaches nearly to the modern mortar, the under stone
being a basin supported upon a tripod.

The quern is also called in Irish cloch-vron, a term which
occurs in the well known Glossary of Cormac Mac Cuillenan,
and has been translated to signify ‘‘ the stone of sorrow,”
having allusion to the laborious and servile occupation which
in ancient times grinding with it was generally esteemed to
be. That such, however, was not always the case, appears
from an anecdote quoted by Mr. Smith from Professor Ten-
nant, respecting Pittacus, king of Mitylene, one of the seven
wise men of Greece, who it seems ‘‘ had been accustomed in
moments of unoccupied languor to resort for amusement to
the grinding mill, that being, as he called it, his best gym-

2L2

392

nasium, or pleasantest exercise in smallest space.” The
memory of this fact is preserved in a song of the Gre-
cian women, called the song of the mill, which began,
** Grind mill, grind! even Pittacus, king of Mitylene, doth
grind !”

In illustration of the use of the quern at an early period,
Mr. Smith cited a notice of it from an ancient Irish poem,
(extracted from the Memoir of Londonderry accompanying
the Ordnance Survey,) by Cuain O’Lochain, who died, ac-
cording to the Annals of Tighernach, in 1024: also an inte-
resting Scandinavian legendary ballad, called the Quern song.
That Shakspeare was acquainted with it, appears from the
allusion in his “ Midsummer Night’s Dream,” where he
speaks of the fairy Puck as labouring in the quern.

Mr. Smith then briefly noticed a few of the many pas-
sages in Scripture referring to the hand-mill, some of which
show it to have been common to the Egyptians and Philis-
tines as wellas the Jews. As to its use in modern times in
Cyprus, Palestine, Hindostan, and generally throughout
the East, he read passages from Shaw’s and Clarke’s
Travels, and from the Journal of Mrs. Farrar, the wife of a
missionary at Nassuck near Bombay. He also noticed an en-
graving in Davis’s China, representing a man working a larger
mill by means of a sort of handspike which he pushes back-
wards.

Mr. Smith then read an extract from Pennant’s Tour to
the Hebrides, referring to the enactment in the reign of
Alexander III. of Scotland, (A.D., 1284,) prohibiting the
use of the quern except during stress of weather, or in
other cases of necessity: notwithstanding which, Pennant
still found it there in 1772.

In Sir Walter Scott’s visit to the Orkneys in 1814, he saw
the quern in the house of an old woman who, practising
the trade of a witch, subsisted by “ selling winds” to the sea-
men of the neighbouring coast. And in the Shetland islands

395

he noticed the rude adaptation of the quern stones to the
purposes of a water-mill.

From a curious book, entitled “the Montgomery Manu-
scripts,” written about 1648, Mr. Smith quoted a description
of a similar attempt in the Barony of Ardes, County of Down,
in Ireland, to convert a hand-mill into one driven by water,
in which ‘ the axle stood upright, and the small stones, or
querns, such as are turned with hands, on the top thereof.
The water-wheel was fixed at the lower end of the axletree,
and did run horizontally among the water, a small force
driving it.”

In conclusion, Mr. Smith pointed out the progressive im-
provement in the form of the quern,—from the pair of rude
oblong stones, which ground the corn by simple tritura-
tion, to the rotatory mortar-shaped quern; thence to the
rounded or rather hemispherical form; and concluding with
the two flattened stones, similar to those used in the water-
mills of the present day.

The Rev. Mr. Todd exhibited to the Meeting a fac si-
mile of a remarkable papyrus roll preserved in the British
Museum.

The Secretary read the following communication, entitled
“* Justification of Mrs. Somerville’s Experiments upon the
magnetizing Power of the more refrangible solar Rays.”* By
George James Knox, Esq. and the Rev. Thomas Knox.

Professor Morichini of Rome was the first to observe
that steel, when exposed to the violet rays of the solar spec-
trum, becomes magnetic. Similar experiments were tried by
Mx. Christie, in 1824; but the most accurate experiments
upon this subject have been performed by Mrs. Somerville,
in 1825, who determined that not only violet, but indigo,
blue and green, develop magnetism in the exposed end of

* Phil. Trans. vol, cxvi. 1826.

594

a needle, while yellow, orange, and red, produce no sen-
sible effect. As many philosophers have failedin repeating
these experiments, we were induced, in the course of the
summer, to undertake the investigation of this subject,
“which has so often disturbed science.” Having procured
several hundred needles, of different lengths and thicknesses,
and having ascertained that they were perfectly free from
magnetism, we enveloped them in white paper, leaving one
of their extreme ends uncovered. ‘Taking advantage of a
favourable day for trying experiments upon the chemical
ray, (known by the few seconds required to blacken chloride
of silver,) we placed the needles at right angles to the mag-
netic meridian, and exposed them for_three hours, from
eleven to one, to the differently refrangible rays of the sun,
under coloured glasses. Those beneath the red, orange,
and yellow, showed no trace of magnetism, while those be-
neath the blue, green, and violet, exhibited, the two first
feeble, but the last strong traces of magnetism.

To determine how far the oxidating power of the violet ray
is concerned in the phenomena, we exposed to the dif-
ferent coloured lights needles whose extremities had been
previously dipped in nitric acid, and found that they became
magnetic (the exposed end having been made a north pole)
in a much shorter time than the others, and that this effect
was produced in a slight degree, under the red (when ex-
posed a sufficient length of time) strongly under white glass,
and so strong under violet glass, that the effect took place
even when the needles were placed in such a position along
the magnetic meridian, as would tend to produce, by the
earth’s influence, a south pole in the exposed extremity.

Conceiving that the mactive state produced in iron (as
observed by Schoenbein) when plunged into nitric acid,
S. G. 1.36, or by being made the positive pole of a battery,
or by any other means (which Dr. Faraday supposed to be
due to a slight oxide formed on the surface, and which may

395

be explained by its electrical state by union with oxygen
becoming disguised, and rendering it until the oxide be
removed incapable of further action) might throw some light
upon the nature of the electrical change produced. Expe-
riments were instituted to this effect, which showed that no
trace of magnetism could be thereby produced.

The President laid before the Academy some supple-
mentary details connected with his ‘‘ Researches respecting
Vibration.”

The President read to the Academy the Address of con-
gratulation to Her Majesty, prepared by Council in pursu-
ance of the resolution of the Academy at its last meeting.

DONATIONS.

Quarterly Journal of the Statistical Society of London.
Vol. II. Part 6. Presented by the Society.

Report of the Committee of Commerce and Agriculture of
the Royal Asiatic Society. 1839. Presented by the Society.

Transactions of the American Philosophical Society.
Vol. VI. Part 3. Presented by the Society.

Proceedings of the American Philosophical Society.
Vol. I. No. 8. Presented by the Society.

Reports of the Council of the Literary and Historical
Society of Quebec, for 1835 and 1839.

Collection de Mémoires et de Relations sur ? Histoire
ancienne du Canada dapres des manuscrits récemment obte-
nus des Archives et Bureaux Publics en France.

- Presented by Robt. Symes, Esq., Secretary of the Society.

The Theory of the Moon. By John W. Lubbock, Esq.
V.P.R.S. &c. Presented by the Author.

Flora Batava. No. 118. 5 plates. By Jan Koops, Pre-
sented by the Author.

396

Ordnance Survey of the County of Mayo, in 125 sheets.
Presented by His Excellency the Lord Lieutenant.

Barlow's Tables of Squares, §c. published under the
Superintendance of the Society for the Diffusion of Useful
Knowledge. Presented by the Society.

Supplement to the Introduction to the Atomic Theory.
By Charles Daubeny, M.D., F.R.S. Presented by the
Author.

March 16. (Stated Meeting.)
SIR Wm. R. HAMILTON, LL.D., President, in the Chair.

A letter from the Secretary of State for the Home De-
partment was communicated by his Excellency the Lord
Lieutenant, informing his Excellency, that the Address of
the President, Council, and Members of the Royal Irish
Academy, had been laid before the Queen, and that Her
Majesty had received the same very graciously.

The Secretary of Council read the following Report,
which was ordered to be entered on the Minutes:

“Tn resigning their office into the hands of the Academy, the
Council have felt it to be their duty, in conformity with the prac-
tice of other kindred societies, to present a brief Report of their
Proceedings, and of the general history of the Academy during the
past year.

“ The Council regret to state that the financial condition of the
Academy has not been an improving one. They believe, however,
that this circumstance (though ’it must create the necessity for
circumspection) will not be regarded as discouraging, when it is
known to have arisen from a cause essentially connected with the
welfare and vitality of the Society. The character of an association
formed for the advancement of any branch of learning, must be

397

judged of by its fruits, and these fruits are, in an eminent and
especial manner, its published memoirs. It is by its Transactions
that it will be estimated beyond the walls of its assembly-room ;
and whatever may be, in other respects, the instruction or the
entertainment derived from its meetings, its Memoirs can alone be
taken to mark its actual progress, and define the limits of its con-
quests in the wide region of the unknown. When, therefore, your
Council state, that it is this very progress which has pressed upon
the funds of the Academy, they believe that it will be granted, that
the circumstance is one rather for congratulation than regret.

‘* The chief source of the expenditure of the Academy is that
arising from the printing of their Transactions. Within the last
few years, however, the papers read to the Academy, and offered
for publication, have greatly increased in number, as well as value;
and, accordingly, the rate of publication of the Transactions, and
the attending expenses, have increased in the same proportion.
This rate, in fact, has of late years much more than doubled ; and
the expenses of printing and engraving have, of course, proportion -
ably augmented.

“‘ The Council have great pleasure in stating, that the publica-
tion of the Proceedings of the Academy, at brief intervals, under
the superintendance of the Committee of Publication, has been
productive of great benefit to the interests of the Academy, by
giving an early publicity to the results of their labours. They are
happy to add, that the new postage regulations have enabled them
to send these Proceedings to all the Societies in Britain with whom
they are in correspondence, as well as to all the non-resident
members.

‘¢ In connexion with the subject of publication, the Council think
it right to mention the steps which have been taken in regard to the
publication of Mr. Petrie’s Essay on the Round Towers of Ireland.
The appearance of this essay having been delayed for many years,
and being earnestly desired by the members of the Academy, the
Council felt that it was incumbent upon them to hasten it as far as
lay in their power. As a preliminary step, a skilful London artist,
Mr. Branston, was brought over to execute the wood-cuts, Mr.
Petrie having agreed, on his part, to make the drawings himself |

398

upon the wood. Notwithstanding the saving of expense thus
attained, the cost of this part of the work (owing to the large
number of illustrations necessary) was considerable, being estimated
at between £300 and £400. The current income not being sufficient
to bear the weight of this charge, the Council applied to the Aca-
demy, and on the 24th of June last, the Academy authorized the
Treasurer to sell stock to the amount of £400.

“‘ Since that time the engravings have been proceeded with,
and part of the sum voted has been already paid. The Committee
of Publication have recently received the assurances of the author,
that the manuscript will be shortly ready for the printer. The

_essay, when printed, will occupy an entire volume of the Transac-
tions; and, from the expectations which have been raised respect-
ing the work, there can be no doubt that the sale will defray a
portion, at least, of the expense incurred.

“To replace the stock above alluded to, as well as to guard
against a progressive diminution of the annual income of the
Academy from the practice of compounding for life, the Council
would suggest, for the consideration of the Council of the ensuing
year, the expediency of investing, in future, the proceeds of the life
subscriptions in the Government funds.

“ The following are. the names of the members which the
Academy has lost by death within the last year :

The Earl of Caledon. John Oldham, Esq.
William Morrison, Esq.

‘The following are the names of the new members added to
the body since the 16th of March, 1839:

John U. Owen, M. D. John A. Bowles, Esq.
Thomas Rhodes, Esq. Sir Philip Crampton, Bart.
Edward Conroy, Esq. William J. Lloyd, Esq.
Nicholas P. Leader, Esq. John Mollan, M. D.
William R. Wilde, Esq. Frederick Burton, Esq.
Alexander Parker, Esq. Joseph Napier, Esq.
Jonathan Osborne, M. D. Thomas Hutton, Esq.
William Longfield, Esq. Rey. Maurice M‘Kay.

William Hill, Esq.

399

“ The subject of members in arrear has come under the consi-
deration of the Council, and, in pursuance of the measures adopted
by the Council of the preceding year, they have recommended to
the Academy a slight alteration in the By-laws relating to de-
faulters, the operation of which will be, that, henceforward, there
will be no members more than two years in arrear, such persons
ceasing, 7pso facto, to be members of the Academy. This modi-
fication of the By-law (which is in conformity with the spirit of the
original) has been adopted by the Academy; and it will have the
effect of removing an apparent opposition between their rules and
usages, besides tending to insure, in future, greater regularity of
payment.

‘* Some objection having been raised to the course recently
adopted by the Academy in reference to the election of new mem-
bers, the Council have prepared an enlarged formula of certificate
for candidates, which, it is hoped, will remove all difficulties, and,
at the same time, convey the required information with regard to
the eligibility of the candidate.

‘‘ It has also been recommended by the Council, and resolved
by the Academy, that the conditions required previous to the ballot
for new members, be all complied with at least one week before
such ballot.

“A charter-book, with the usual obligation engrossed, has
been prepared to receive the signatures of new members on admis-
sion. The Council request that members, who have already
signed in another roll, will write their names also in this book, so
as to render it, as far as possible, a complete record of the history
of the Academy.

‘“* The miscellaneous property of the Academy consists of their
library (including their collection of MSS.) and their (as yet) small
collection of antiquities.

‘** On the subject of the library the Council have to state, that a
Book Committee was appointed at the commencement of the year,
to examine the state of the library generally, and to report thereon
to the Council. The additions made to the library, during the
past year, have been confined chiefly to the regular periodicals.
The collection of MSS. has been enriched by a copy of the Book

400

of Lismore, which was lent by his Grace the Duke of Devonshire,
and transcribed at the expense of the Academy.

“The Council. have the pleasure of stating, that the task of
forming a perfect catalogue of the library has been nearly com-
pleted by the Assistant Librarian, Mr. Clibborn; and they gladly
avail themselves of this opportunity to express their sense of the
value of the services which that gentleman has rendered to the
Academy during this, the first year of his office.

** The Societies whose Transactions enrich the library of the
Academy are:

The Royal Academy of Sciences, Berlin.

The Royal Academy of Sciences, Brussels.

The Royal Society of Sciences, Copenhagen.

The Physical and Natural History Society of Geneva.
The Royal Academy of Sciences, Lisbon.

The Royal Academy of History, Madrid.

The Italian Society of Sciences, Modena.

The Royal Academy of Sciences, Paris.

The Imperial Academy of Sciences, St. Petersburgh.
The American Philosophical Society, Philadelphia.
The Royal Academy of Sciences, Turin.

The Royal Society of London.

The Royal Society of Literature, London.

The Royal Society of Antiquaries, London.

The Royal Astronomical Society of London.

The Geological Society of London.

The Royal Society of Edinburgh.

The Linnean Society.

The Cambridge Philosophical Society.

The Manchester Philosophical Society.

The Asiatic Society of Calcutta.

‘“‘ In addition to this list, the Council have, during the past
year, negotiated an interchange of Transactions with the Gco-
logical Society of France ; the School of Mines of Paris; the

Zoological Society of London; and the Institution of Civil En-
gineers.

401

*“'The Academy having purchased, in the year 1837, a small
collection of antiquities, belonging to Mr. Underwood, the atten-
tion of Council was directed to their arrangement; and, on the
22nd of April last, the sum of £50 was placed at their disposal by
the Academy, for the erection of convenient cases for their recep-
tion. This collection has since received two additions of great
historical interest and high value, namely,—the Cross of Cong,
presented by Professor Mac Cullagh, and two gold Torques, dis-
covered at Tara, presented by a number of gentlemen who sub-
scribed liberally for their purchase. The Council trust that others
will be induced to follow the example set by these public-spirited
individuals, and will contribute to the formation of a collection
illustrative of the national antiquities, the study of which it is one
of the main objects of the Academy to foster and promote.

‘ The medal for the best essay in Polite Literature and Anti-
quities, communicated during the three years preceding the Ist of
January, 1839, has been awarded by the Council (as the members
of the Academy are already aware) to Mr. Petrie, for his paper on
the Antiquities of Tara Hill.

“The Council of the ensuing year will have to consider for
medals, the papers in Mathematics (pure and applied,) and in
Polite Literature, which have been communicated during the three
years previous to the Ist of January, 1840.”

The Auditors appointed by Council to examine the
‘Treasurer’s Accounts reported as follows:

** We have examined the above Account,* with the vouchers
produced, and have found it to be correct ; and we find that there
is a balance in bank of £150; and in the Treasurer’s hands of
£62 8s., making a total balance of £212 8s. sterling.

** (Signed, )
“ FRANC SADLEIR,

“ SAMUEL Litton.”’
“ March 14, 1840.”

* Entered in the Treasurer’s Book,

402

‘“‘ The Treasurer reports that there is £1384 6s. in 3 per Cent.
Consols, and £1500 in 33 per Cent. Government Stock, to the
credit of the Academy in the Bank of Ireland ; the latter being the
Cunningham Fund.

“* (Signed, )
“Tuomas HERBERT ORPEN.”
‘“* March 14, 1840.”

The ballot having closed, the President requested the
Provost and Dr. Litton to assist the Officers in examining
the balloting lists.

The Scrutineers reported that the following Gentlemen
were duly elected Officers and Council for the ensuing
year:

President—Sir William Rowan Hamilton, LL. D.

Treasurer—Thomas Herbert Orpen, M. D.

Secretary to the Academy—Rev. Joseph H. Singer, D.D.

Secretary to the Councit1—James Mac Cullagh, LL. D.

Secretary of Foreign Correspondence—Rev. Humphrey
Lloyd, A. M.

Librarian—Rev. William Hamilton Drummond, D. D.

Clerk and Assistant Librarian—Edward Clibborn.

Committee of Science.

Rey. Franc Sadleir, D. D., Provost of Trinity College ;
Rev. Humphrey Lloyd, A. M.; James Apjohn, M. D.;
James Mac Cullagh, LL. D.; Rev. William Digby Sadleir,
A. M.; Robert Ball, Esq. ; Robert Kane, M. D.

Committee of Polite Literature.

His Grace the Archbishop of Dublin; Rev. Joseph
Henderson Singer, D. D.; Samuel Litton, M. D.; Rev.
William Hamilton Drummond, D. D. ; Rev. Charles Richard
Elrington, D.D.; Rev. Charles William Wall, D.D.; Rev.
Thomas H. Porter, D. D. »

403

Committee of Antiquities.

Thomas Herbert Orpen, M. D.; George Petrie, Esq. |
R.H. A.; Rev. Caesar Otway; Very Rev. the Dean of St.
Patrick’s; Rev. James Henthorn Todd, D. D.; Henry J.
Monck Mason, LL. D.; Aquilla Smith, M. D.

The President then appointed, under his hand and seal,
the following Vice-Presidents :

His Grace the Archbishop of Dublin; the Provost of
Trinity College; the Rev. Humphrey Lloyd; the Very
Rey. the Dean of St. Patrick’s.

DONATIONS.

Philosophical Transactions for 1839. Parts 1 and 2.
Proceedings of the Royal Society. Nos. 37, 38, 39,
_ and 40.

Catalogue of the Scientific Books in the Library of the
Royal Society.

Fellows of the Royal Society. ‘Nov..1839.

List of the various Councils of the Royal Society from
1800 to 1839.

Presented by the Society.

Mecanique Celeste. Translated by Dr. Bowditch. Vol.
IV. Presented by the Translator’s Children.

Transactions of the Cambridge Philosophical Society.
Vol. VII. Part 1. Presented by the Society.

Memorie della Societa Italiana delle Scienze. Tome XXII.
Parte Matematica. Presented by the Society.

Premier Memoire sur les Kaolins ou Argiles a Porcelaine.
Par M. Brongniart. Presented by the Author.

Memoires de la Societe de Physique et d Histoire Natu-
relle de Geneve. Tome VIII. 2me Partie. Presented by

the Society.

404

Comptes Rendus Hebdomadaires des Seances de l’ Academie
des Sciences. Premier Semestre, 1840. Nos. 1—5. Pre-
sented by the Academy.

A few Notes on the History of the Discovery of the Com-
position of Water. By J. O. Halliwell, Esq.

A Catalogue of the Miscellaneous Manuscripts preserved
in the Library of the Royal Society. By J. O. Halliwell,
Esq.

Presented by the Author.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY,

1840. No. 22.

April 13.
SIR Wa. R. HAMILTON, LL.D., President, in the Chair.

Samuel Hanna, M. D., William Torrens M‘Cullagh, Esq.,
George M‘Dowell, Esq., F.T.C., John Ball, Esq., Rev.
Dr. Traill, Robert Alexander Wallace, Esq., and Thomas
Newenham, Esq., were elected Members of the Academy.

Dr. Apjohn, on the part of Surgeon Grimshaw, drew the
attention of the Academy to a modification of the air-ther-
mometer recently devised by the latter gentleman. The
well-known objection to the ordinary air-thermometer he
stated to be, that the air within the ball being in communica-
tion (through the interposed column of fluid) with the external
air, its volume comes to be affected not merely by changes
in the temperature of the surrounding medium, but by the
perpetually occurring variations in the atmospheric pres-
sure. In fact, to render its indications truly thermometric,
they must be reduced by calculation to a constant pressure,
reference being made in every observation to a correct ba-
rometer. Nor did Sir John Leslie, in his differential thermo-
meter, get rid of this difficulty. It is true that all con-

2M

406

nexion of the air within the instrument with the external at-
mosphere is cut off; but when one of the balls is heated,
and the elasticity of the air within it thus augmented, and
the intervening column of fluid driven towards the cool ball,
the elasticity of the ‘air within the latter is also obviously in-
creased by compression. Equal increments of temperature
cannot, therefore, produce equal augmentations of volume,
and, when the stem of such an instrument is divided into
parts of equal capacity, the corresponding temperatures
constitute, not an arithmetical series, but one which in-
creases much more quickly. In fact, if ¢ be the tem-
perature, » the volume of the air in the heated ball, and
v the volume of air in the cool ball, ¢ varies not as 2,
but as .

This source of embarrassment in the air thermometer
Mr. Grimshaw removes by a contrivance, a notion of which
may be simply conveyed by describing his instrument
as a differential thermometer, in the cool ball of which
is placed a barometer, while to the side of the same ball a
little syringe is attached, by means of which air may be
pumped in or out, and the elasticity of the included air thus
rendered invariably the same, before the temperature (exhi-
bited upon the scale of equal parts attached to the stem in
connexion with the hot ball) is registered. ‘Two forms
of this instrument were placed on the table of the Academy,
which, however, Dr. Apjohn stated should be considered
rather as rough models, than as finished instruments. Dr.
Apjohn observed, that Mr. Grimshaw intended attaching
to his thermometer a provision for keeping the barometer
vertical ; and marking upon this latter instrument two addi-
tional points of constant pressure,—one higher, the other
lower, than the atmospheric standard,—by the use of which,
when necessary, the scale of the instrument may be greatly
extended, so as to comprehend with ease the entire of the
atmospheric range of temperature.

407

Dr. Apjohn read a paper on the subject of an essential
oil not long since observed during the rectification of common
whiskey. This substance he received in December, 1838,
from Mr. Scanlan, who had it from Mr. Bowerbank, an emi-
nent London rectifier. Shortly previous to this time, it was
observed by Mr. Eneas Coffey, the inventor of the cele-
brated patent still, in the faint receiver at the extensive
distillery of Sir Felix Booth; and Mr. Scanlan himself, upon
coming over to Dublin, and visiting the establishment of
Mr. Busby, at Blackpitts, recognized this same oil precisely
where it was observed by Mr. Coffey, namely, in the vessel
into which the weak spirit which comes over towards the
close of the distillation is conducted.

Dr. Apjohn stated in detail the properties of this fluid, and
the experiments which he made with the view of determining
its composition. It was burned in the usual way with oxide
of copper, and gave, as the means of three separate experi-
ments, the following results :—

Carbon. .... 68.13

Hydrogen. . . 13.33
Oxygen .... 13.54

100

The most simple formula corresponding nearly with
these results is c; Hg 0, and it was therefore that which he
adopted. Assuming it as the true one, the composition of
the oil would be,—

Oxygen .... 17.95

106

The deficiency in the carbon, experimentally determined,
is not greater than what usually takes place. But the error
2mM2

408

in the hydrogen, though trifling in amount, being upon the
opposite side to that on which it usually occurs, it became
expedient to resort to some method of verification. The
specific gravity of the vapour of the oil was therefore taken
by the well known method of Dumas, and found to be 3.137 :
the formula c;H,0 would make it 3.072. But there is
here so close a correspondence between experiment and
calculation, that no doubt can remain as to the correctness
of the basis on which the latter rests, or that the formula
already arrived at represents correctly the constitution of the
oil.

These experiments were made in the winter of 1839, and
Dr. Apjohn stated that he was then under the impression
that the oil in question was a new substance, or rather one
which had not been previously described. Some months
after, however, upon looking over the second part of Pro-
fessor Graham’s Elements of Chemistry, he was surprised
to find (in a table of the volumes of atoms in the gaseous
state,) mention made of a substance under the designation
of “oil of the ardent spirits from potatoes,” to which was
attributed the very same formula, and density of vapour,
which he had found to belong to the oil of corn whiskey,
given him by Mr. Scanlan. Anxious to investigate the
matter further, and to ascertain whether the two oils were cer-
tainly the same, Dr. Apjohn looked into Dr. Thomson’s fifth
volume on Organic Chemistry, and found there (page 481)
a notice of the potato oil, with a reference to the 30th and
56th volumes of the Annales de Chimie, in the former of
which its origin and properties are described by Pelletan,
and in the latter of which its analysis is given by Dumas.
Upon perusing these papers, his suspicions as to the identity
of the two oils were confirmed. In composition and proper-
ties they are the same; the only difference being, that Pelletan
represents the potato oil as having the specific gravity .821,
whereas Dr. Apjohn found that of the corn oil but .813,—a

409

difference, however, easily explained by the circumstance of
the former chemist not having taken the necessary steps for
purifying perfectly the liquid he examined.

As a very unusual coincidence it may be observed, that
the specific gravity of the vapour of potato oil, as obtained

by Dumas, is 3.147, or but unity in the second place of deci-
~ mals greater than has resulted for the corn spirit oil from Dr.
Apjohn’s experiments. The oil therefore of Pelletan and
Dumas is not, as is generally supposed, peculiar to potato
spirit, but occurs also in that developed by the fermentation
of the cerealia. From this latter source also it admits of
being obtained in great quantity. When first observed by
Mr. Coffey at Sir Felix Booth’s, there was an inch of it in
the faint receiver; and from the diameter of this vessel he
estimated its total amount to be at least fifty gallons. This
is the quantity produced at that establishment every fort-
night, the excise laws compelling the distiller to distil and
brew alternately, and about a week being consumed in each
process.

The whiskey manufactured some years ago contained,
Dr. Apjohn observed, a considerable quantity of this oil, and
owed to its presence a great deal of the pungency of taste
and smell by which it was distinguished. From the nature
of the still at present generally used, but a small por-
tion of this substance passes over ; and hence the reason why
the spirit now made is, as compared with the product
of the old processes, less disagreeable to the palate, and pro-
bably less injurious to the constitution. It is undoubtedly
owing to the same cause, (an improvement in the process
of distillation,) that this oil has at length been noticed in the
distillers’ faints. Upon the old system of manufacture the
greater portion of it was driven over, and was held dissolved
by the spirit into which it was thus introduced ; but with the
modern stills, particularly that devised by Mr. Coffey, no-
thing having so high a boiling point as this oil, can by pos-

410

sibility pass into the part of the apparatus where the spirit
is condensed.

Dr. Apjohn proceeded to observe, that the potato spirit
oil, as it has been hitherto called, has of late attracted much of
the attention of chemists. Pelletan, from some rough expe-
riments upon it with acids, threw out the idea that it was
more analogous to alcohol than to the volatile oils, and this
opinion seems to have been in some measure adopted by
Dumas. More recently M. Auguste Cahours (Annales de
Chimie, January, 1839) has revived this opinion, and con-
cluded it to be one of the groups including alcohol, pyroxilic
spirit, and acetone. He represents it by the formula
Cio Hig Op = Co Hip + 2H 0, which obviously makes it quite
analogous to alcohol in composition. The carbo-hydrogen
Cy Hip he has insulated, by distilling the oil from anhydrous
phosphoric acid. He calls it amilene, and finds the specific
gravity of its vapour to be 4.904, so that an atom of it gives
but one volume of vapour,—a circumstance in which, as Ca-
hours observes, it agrees with Dr. Kane’s mesitylene, but
differs from the carbo-hydrogens C4 4 and C2 Ha which occur
in alcohol and pyroxilic spirit. By acting upon potato spirit
oil, (or, as Cahours calls it, amilic alcohol,) with sulphuric
acid and chlorine, he obtained products corresponding per-
fectly with those ‘yielded by ordinary alcohol when similarly
treated. The amilic ether, or Cjo Hj -+ HO, he did not suc-
ceed in insulating.

Dr. Apjohn observed, in conclusion, that he had been
aware, for more than twelve months, of the identity of the
fluid oil which he had examined with the potato spirit oil of
the French chemists ; but having engaged in the examina-
tion of another oil, of the consistence of butter at ordinary
temperatures, which is well known to exist in corn spirit, it
was his intention, when he had completed his experiments
upon it, to give publicity to what he knew of both oils in the
same paper. In the mean time, however, Liebig and Pelouze

411

published their memoir (Annales de Chimie et de Physique,
tom. 63, p. 113,) upon an oleaginous matter, which comes
over during the distillation of wine, towards the close of the ~
process, and which they showed to bea mixture of what they
denominated cenanthic acid with cenanthic ether. Having pe-
rused this paper, Dr. Apjohn felt satisfied, from the progress
he had already made in the investigation, that the buttery
matter found in small quantity in ordinary whiskey, and
to a much greater amount in the distillers’ faints, was in a
great measure the same with the substance which the che-
mists just named had found to come over during the distil-
lation of wine in the production of brandy. A third oil,
however, different from the cenanthic acid and cenanthic
ether, he soon found to be present; and while occupied in
examining it, his attention was directed by Dr. Kane to
the 2nd part of Poggendorf’s Annalen for 1837, which
contained a paper on the subject of these products, by a
German chemist named Mulder. In this paper it is sa-
tisfactorily shown that the solid oil of malt and corn spirit
is a mixture of the oil of wine of Liebig and Pelouze,
with a third substance, which he called oleum sittieum.
Being thus clearly anticipated as respected the solid oil, Dr.
Apjohn observed that he had no motive for further delay ;
and he accordingly submitted to the Academy the facts from
which he was enabled to conclude that the fluid oil (or amilic
alcohol of Cahours) is not, as is generally thought, peculiar
to potato spirit, but occurs also in that which is manufactured
in this country by the fermentation of a mixture of malted
and unmalted grain.

412

DONATIONS.

Comptes Rendus Hebdomadaires des Seances de 0 Academie
des Sciences. Premier Semestre, 1840. Nos. 6—12. Pre-
sented by the Academy.

Proceedings of the Numismatic Society of London, 1837-
38. Presented by the Society.

The New County Book of Tipperary. By Jeffries Kings-
ley, Esq., M.R.I. A. Presented by the Author.

An Essay on the Mineral Structure of the South of Ire-
land. By Thomas Weaver, Esq., M. R.I. A. &c. Presented
by the Author.

A Letter to the President of the Royal Irish Academy.
By Sir William Betham, M. R. I. A., &c. Presented by the
Author. -
An Essay on the Heat of Vapours and on Astronomical
Refractions. By John William Lubbock, Esq. Presented
by the Author.

Greenwich Observations for 1838. Presented by the
Astronomical Society.

Bulletins de 0 Académie Royale des Sciences et Belles-
Lettres de Bruxelles, année 1839. (Nos. 5 and 6.) Presented
by the Academy.

Annuaire de lV Academie Royale des Sciences et Belles-
Lettres de Bruxelles, pour les Années 1839-40. Par le Di-
recteur A. Quetelet. Presented by the Author.

Notice sur Martin van Marum. Par A. Quetelet. Pre-
sented by the Author.

De la Liberté Physique et Morale. Par L. A. Gruyer.

Examen critique d'un Mémoire de M. P. Leroux, intitulé,
Du Bonheur. Par L. A. Gruyer.

Presented by the Author.

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April 27.

SIR Wm. R. HAMILTON, LL.D., President, in the Chair.

His Grace the Archbishop of Dublin gave a verbal ac-
count of some observations which he had made upon the
weather, in connexion with the prognostic drawn from the
variations of atmospheric pressure, as indicated by the baro-
meter. The sudden changes of the barometer, his Grace
observed, were well known to be connected with correspond-
ing changes of the weather as to rain or drought, and the
great and rapid falls with the sudden approach of a gale of
wind; but it did not seem to be so generally remarked, that
the slow and continuous changes of the height of the mercury
in the barometer were likewise indications of the approach
of a season of long continued wet or dryness. It was to some
connexions of this latter kind, noticed by himself, that he
now drew the attention of the Academy. The first of
these occurred in the early part of the summer of 1818, when,
fromthe slow and gradual rise of the barometer for the space of
ten days, he was led to predict the approach ofa long continued
dry season. The drought which followed was one of the most
remarkable that had occurred in this climate for many years.
The second instance of the same kind observed by his Grace
was in the early part of the spring of the present year. On
the 17th of February the barometer commenced to rise, but
very slowly, and the rise continued for six or seven days; he
was thus led to expect a long continuance of dry weather ;
and the result, as is well known, fully verified the anticipa-
tion, the change being followed by more than three weeks,
during which there was not a single drop of rain, and that
too at a season of the year usually wet.

The Secretary read a notice by Mr. George Knox on the

415

subject of the Contact Theory of Electricity, as connected
with the views suggested in his paper “ on the Direction and
mode of Propagation of the Electric Force, in media not un-
dergoing Electrolyzation.” Mr. Knox referred, at some
length, to the recent experiments of M. Peclet on this sub-
ject, published in the Annales de Chimie.

The Secretary read some memoranda of the native Indian
account of Tabasheer, communicated by William Farran,
Esq.

The Secretary read the continuation ofa paper by James
Orchard Halliwell, Esq., F.R.S., F.S.A., &c. &c., on the
Boetian numerical Notation.

I.

An Inquiry into the Period of the first Use of the Zero
by those Writers who adopted the Notation of the Boetian nu-
merical Contractions.

During the researches made by M. Chasles, of Chartres,
and myself, on the subject of the Boetian numerical contrac-
tions,—the former published in the Transactions of the Brus-
sels Academy, and the Comptes Rendus of the Academy of
Sciences, the latter in an Appendix to the Rara Mathematica,
—we came to no definite conclusion on the nature of the
change from the use of the abacus to that of local position
and the cipher. Some documents recently discovered by me
have strikingly elucidated this point of the inquiry, and as they
develop an entire new view of a system before only conjec-
tural, I have ventured to place the results before the notice
of the Royal Irish Academy, the more especially as the
general objects of that body render the subject more appro-
priate to their views than those of any society in England.

Before I enter into this short discussion, to give the
reader an idea of the state the subject was left in, I will
quote my latest opinion :—

416

Tt would be impossible, with the few materials yet
brought to light, to conjecture with any great probability
how far these Boetian contractions may have influenced the
introduction, or cooperated with the Arabic system to the
formation of our present numerical notation. It appears to
me highly probable that the two systems became united,
because the middle age forms of the figure five coincide
with the Boetian mark for the same numeral, and those of
two others are very similar. The idea of local position,
again, may have had an independent European origin; the
inconveniences of the abacus on paper would have suggested
it by destroying the distinguishing boundaries, and invent-
ing an arbitrary hieroglyphic for the representation of an
empty square.”—Rara Mathematica, p. 111.

Now, from the Mentz MS. in the Arundel Collection, it is
very evident that their mode of operation with the abacus
had received one great improvement on the Greek and
Roman system, the abolishing the necessity of motion, and
only using the table cum pulvere, as a means for distinguish-
ing position. Thus, in the following addition sum, using the
names instead of the cabalistic characters, we have an ex-
ample of their method of proceeding:—

Andras Igin Calcis Andras
Tenis Arbas Ormis Celentis
Celentis Calcis Igin

Thus making a total of — celentis, calcis, zero, igin. Now, it
is evident, that in order to do away with the necessity of
this table, supposing the contractive marks again substituted
for the latter words, we have only to imagine an arbitrary
character for the deficiency under the ormis, and the modus
operandi is synonymous with our own present form.

417

The following are new instances of the appearance of the
zero without its use :—

MS. Hatton. 7, we find the following passage :—“ inscri-
bitur et in ultimo figura 0, sipos nomine. Que licet numerum
nullum significet: tum ad alia quzedam utilis est.”

MS. Lansd. 842,is a contractive mark for a sipos, outside
the drawing of the abacus.

MS. Hatton. 112. The sipos is given with its contrac-
tion, but is only used to fill up the space in the abacus.

Now, at the last page of a very beautiful MS. of the
translation of Euclid, by Athelard, of the fourteenth century,
and in the explicit of the fifteen books, the number 15 is
written in these singular contractions, and without a division.
This MS. is in the Arundel Collection of MSS., and was ac-
cidentally discovered by me when looking into it for an-
other purpose.

The new face thus put upon the question of their gradual
identity with the present system, and the satisfactory evi-
dence that the latter portion of my former conjecture is
correct, is sufficient almost to make me bold enough to
venture on the truth of the previous one. It must be recol-
lected, however, that on the last point one document only
has yet been discovered.

II.

The middle-age Knowledge of the Alabaldine Notation
considered as an Argument in Favour of the early Introduc-
tion of the Boetian Zero into Western Europe.

I beg leave to make the following additional observations
in corroboration of what was stated by me on the same subject
in a paper read before the Academy on the 13th of January.

The recent dispute* between M. Chasles and M. Libri,

__ * An account of the whole discussion may be found in the Comptes Rendus
‘Hebdomadaires of the Academy of Sciences, for the 7th and 14th of October last,
pp. 447-454, and pp. 463-472.

418

before the French Institute, relative to the bearing of certain
points in my Essay on the Boetian contractions, has not es-
tablished a single important fact, save that the knowledge of
local value was apparent in the integral abacal operations of
these contractions. On the question of the period of the
introduction of the Boetian zero, confessedly the most curious
and difficult point to be established, none of the continental
writers, M. Chasles, M. Libri, or M. Vincent, have ven-
tured on more than random conjectures. .

The Boetian fractional notation, or the Alabaldine nota-
tion,” was first explained in the above-mentioned Essay,
previously to which no rational conjectures respecting them
had been made. I amnow enabled to prove that this notation
was not only recognized, but commonly employed throughout
the middle ages.

A passage at the end of the second book of “ Boetii Geo-
metria,” de minutiis,} proves that the system was contempo-
rary with that writer. Bede, in his Treatise on Arithmetic,
has given a whole chapter to it. Next comes the Arundel
MS.{ of the twelfth century, from which I am enabled to
give a most exceedingly curious specimen of their modus
operandi :—

QuestTion.§ It is required to multiply semis (=) into

siliqua is : What is the result 2
IM" \ 144

SoLution. Semis = as . semiuncia, but as = tigin; there-
fore, semis = igin.semiuncia = semiuncia; because igin
is the Boetian unity.

* So called from its presumed inventor.
+ MS. Lansd. 842, B. &c. $ No. 343, in the British Museum.

§ It is almost unnecessary to observe that this is much simplified and abridged
from the MS.

419

Now serupulus = —_ scrupulus; because calcis _. i
: =22m
calcis ‘ caleis — “*
: . serupulus
“. scrupulus = calcis. si! Saeed
calcis

scerupulus Bo f . sas
Bu ee = siliqua .. scrupulus = calcis. siliqua.

caleis
pe . serupulus . , serupulus
and semis. siliqua = semis. ——_——-._ = semiuncia . ——_.—
calcis caleis
= semiuncia. — . scrupulus.
: calcis

igin __ andras.igin _

But, by the integral notati ——
pais ISteaEE nipiahiee calcis andras.calcis

igin andras igin gin Atel
Sm es = 8 8 = semiuncia « duella.
andras_ caleis andras ormis

Therefore,

semis . siliqua = semiuncia . semiuncia . duella. scrupulus.

We have now to reduce the

igin igin- __ igin
andras* andras ~ arbas
and, semis . siligua = sicilius . duella . scrupulus.

semiuncia . semiuncia = = sicilius.

We have thus the required quantity in a very compli-
cated form. To effect the reduction of this is the work of
another long operation, which it is unnecessary to repeat here,
as the above will sufficiently serve for an example of the la-
borious, though ingenious, plan which was pursued.

Gerbert, in his Treatise on Geometry,* makes use of this
notation, and adds, guod abaciste facillimum est.t| ‘The MS.
Burney, 213, in the British Museum contains an express
treatise on it. Added to which, the Alabaldine contractions _
are constantly occurring in mathematical manuscripts, and
till very lately no one had the slightest idea of their true
nature.

* Pezri Thesaurus, t. i. p. ii, col. 13. + Ib. col. 30,

420

That the writers on the Boetian contractions could have
accomplished the solution of intricate fractional questions
(entirely dependent on the principle of local position) without
the knowledge of the zero, or some arbitrary character to
express its situation, appears to me to be quite impossible.
Above all, it must be remembered that the abacus was not
employed with the Alabaldine notation.

A paper was read by William R. Wilde, Esq., on the
animal remains and antiquities recently found at Dunshaugh-
lin, in the county of Meath.

Surgeon Wilde prefaced his observations by stating,
that the communication which he was about to make, on
the subject of the vast collection of bones which were recently
discovered in the county of Meath, was but introductory
to a more detailed description of their zoological and anato-
mical characters which he purposed bringing before the
Academy at a future meeting. But, having had several
opportunities of visiting the spot where these remains were
found, and having collected some information upon: the
subject from the persons who superintended, and others who
were actually engaged in making the excavations, he felt it
necessary to lay before the Academy a popular description
of the place,—in order to show under what circumstances
these bones were found, and to enable the members pre-
sent to form some idea as to the nature of this very re-
markable collection. In addition to this statement of facts,
he would likewise exhibit several of the antiquities found
in connexion with the animal remains, in the hope that the
antiquary and the historian might, from their examination,
be enabled to arrive at some probable conclusion as to the
date of the construction of this place.

The following is an extract of Mr. Wilde’s statement:
“ About a mile to the east of the village of Dunshaughlin,

421

on the townland of ZLagore, and near the margin of a
‘ cut-away’ black bog, is a circular mound, slightly raised
above the surrounding plain, its highest central part being
about eight feet above the margin, and the circumference of
the mound measuring 520 feet. A small stream passes
through this circle ; and the whole bog in which it is situate
occupies a slight concavity of about a mile and half in cir-
cumference, bounded by raised tillage and pasture lands.
Within the memory of some of the old inhabitants of theneigh-
bourhood, this bog was covered with water during the greater
part of the year, and it is so invariably during winter, up to
the present period. A large pond is still in existence in one
of the fields adjoining the mound. (Mr. Wilde exhibited a
map of the mound and the surrounding country.) A few
years ago, some labourers, while clearing the stream-way,
discovered several bones protruding from its sides; and
in May, 1839, the quantity of bones found in the drain was
so great, and their value so well known, that a further exami-
nation was made, when it was discovered that the greater
part of the mound was composed of the remains of animals,
placed there in the following manner:

‘* The circumference of the circle was formed by upright
posts of black oak, measuring from six to eight feet in
height ; these were morticed into beams of a similar ma-
terial, laid flat upon the marl and sand beneath the bog,
and nearly sixteen feet below the present surface. The up-
right posts were held together by connecting cross beams,
and fastened by large iron nails; parts of a second upper
tier of posts were likewise found, resting on the lower ones.
The space thus inclosed was divided into separate compart-
ments, by septa or divisions that intersected one another in
different directions ; these were also formed of oaken beams,
in a state of great preservation, but joined together with
greater accuracy than the former, and in some cases having
their sides grooved or rabitted to admit large pannels driven

2N

422

down between them. The interior of the chambers so formed
were filled with bones, and black moory earth, and the heap of
bones was raised up in some places within a foot of the surface.
It was generally found that the remains of each species of
animal were placed in separate divisions, with but little
intermixture with any other; and the antiquities, &c., were
found along with them, without any order or regularity, but
for the most part near the bottom.”

The most numerous class of bones were those of oxen,
and of these Mr. Wilde exhibited the heads of several
varieties, in a state of great perfection. Some of these were
identical with those which formed the subject of Mr. Ball’s
communication to the Academy, in January, 1839,and which
were discovered in the bogs of Westmeath, Tyrone, and
Longford; others bore a strong resemblance to them.

_ There were other specimens of these oxen which, although
of rather diminutive size, equalled, as to beauty of head and
horn, the modern improved breed of the English short-
horned Durham, and the middle horned Devon and Ayre-
shire,—being distinguished by the peculiarities of the head,
and in particular of the slug or core on which the horn is
moulded, and which had remained quite perfect, although
the cuticular horn had been destroyed.

A fourth variety was that which has been denominated
the true Irish cattle,—the long-horned, or crumple-horned,
the improved large breed of which still exists in some
of the midland counties of Ireland, particularly Roscom-
mon. In this variety there is a very remarkable pro-
jection of the upper portion of the frontal bone between the
horns, which latter turned downwards, and alittle backwards,
somewhat in the manner of the Craven or Lancashire stock.

There were also several heads of the polled or hornless
variety, called in this country mhaol, exhibiting some slight
differences as to the fineness of their heads, but in general
resembling the Galloway and Angus breeds.

423

All these heads differ from those figured in Cuvier’s
Ossemens Fossiles ; and Mr. Wilde regretted that he was at
present unable to draw the necessary comparisons between
the existing breeds and those found at Dunshaughlin, from
the want of a collection of the heads of the former in the
museums of this country, and from our not possessing any
work having accurate plates of the anatomical characters
of the horned cattle, although it is upon such characters that
the zoologist and the cattle-breeder found their distinctions.
A great number of these heads are broken in the centre of
the forehead, as if by some blunt instrument—apparently
the mode of slaughter. It might naturally be expected that
the best breeds and the largest assemblage of these animals
should be found (even at an early period) upon the fertile and
extensive plains of Meath; and the whole collection offers
an incontestible proof, that at a remote period Ireland
possessed not only several varieties of horned cattle, but also
breeds analogous to those most valued in England at the
present day, and lately re-introduced into this country.

The animal, whose remains were found in the greatest
abundance next to the ox, was the pig—several of the heads
of which were produced, of all ages and sizes, but of a
smaller description than those at present bred in this country.

There were one or two specimens of the horse and ass.
The bones of a number of deer were likewise found in the
collection, both male and female. The former, some of the
antlers of which are quite perfect, prove the race to have
been the common deer; and in no instance were the horns of
the Fallow deer found—verifying the general opinion of natu-
ralists, that the latter are an introduced race into this country.
Large quantities of the bones of goats of all ages were dug
up. The head of a four-horned sheep was also discovered
in the same locality, of a peculiar form, to be described here-
after ; this was the only instance of the sheep that Mr.
Wilde had been able to procure.

424

Some of the most remarkable remains found in this in-
closure were those of a very large and powerful dog, appa-
rently belonging to an animal of the grey-hound tribe, but of
enormous size—the heads measuring, in the dry bone, nearly
eleven inches in length, and principally characterized by the
great extent and magnitude of the occipital crest, and the
projecting muzzle. Mr. Wilde stated it as his opinion, that
we had now, for the first time, an opportunity of judging of
the form and characters of the dogs denominated Irish
wolf dogs, to which breed he considered these heads to have
belonged. There were also several foxes, but no wolves.
With these remains were mixed up the shells of limpids and
buccinums; and a few bones of birds; some portions of
burned bones, and large quantities of hazel nuts. Most. of
the bones of the larger ruminants were unbroken ; and up-
wards of 150 cart-loads of bones have been already dug out
of this inclosure, and have been forwarded to Scotland for
manure, none of them being in a fossil state.

Nearly in the centre of the heap, and within two feet of
the surface, were discovered two human skeletons, lying at
length, and without any surrounding wood or stone work, &c.
The superstitions of the people who were employed in making
the excavation, led them to re-deposit ‘them in the neigh-
bourhood, and they cannot now be obtained ; but Mr. Wilde
produced some of the vertebrze, and the frontal bone of one of
these bodies, and remarked upon the similarity of the latter
to other heads found in ancient Irish monuments, and in par-
ticular its striking analogy to those found in the Cromleigh
recently opened in the Phcenix-park.

The antiquities found in this place may be divided into
the warlike, the culinary, and the ornamental. They con-
sisted of zron swords of different lengths, with straight edges
and angular points, and bearing a resemblance to the ancient
Roman swords. Very many knives were found, of different
shapes and sizes, with iron spear, javelin, and dagger blades,

425

and part of the boss or central ornament of a shield ; but no
brazen weapons of any description. Two querns, or ancient
corn mills, were found on the marl, at the bottom of the in-
closure ; sharpening stones; iron chains ; aniron ax; a brazen
pot, and three small brass bowls of most elegant shape and
workmanship ; several articles precisely resembling miniature
frying pans, of about three inches in diameter (perhaps incense
burners) ; circular discs of turned bone, wood, and slate, like
those supposed to have been used at the end of the distaff;
small shears, like the modern sheep shears; brazen, bone, and
iron pins, from four to six inches in length—the former of great
beauty of construction ; brooches, and parts of buckles, con-
taining pieces of enamel and mosaic work ; bracelets; wooden
(yew tree) combs, tooth-picks, etwees, and other articles be-
longing to the toilette. Several of these articles show an
extraordinary state of perfection of the arts at the period
of their construction.

A very curious bone was likewise found, and exhibited to
the meeting, with a number of devices carved on it, as if by
way of practice in engraving; these devices consisted of scrolls
and marks precisely similar to those formed on ancient Irish
crosses, ornaments, and grave-stones. There were no crosses,
beads, or Christian sacred ornaments found in the excavation ;
but a number of pieces of stags’ horns sawn across, and also
pieces of hazel wood, in great quantity, as if laid up for
fire-wood, were found in one spot near the bottom.

On the surface of the mound, but apparently without
any connexion with it, a groat of Robert the Second, of
Scotland, was picked up.

Some of the articles exhibited now belong to the collection
of the Dean of St. Patrick’s; but the greater number were
forwarded for the inspection of the Academy, by Mr.
Barnwall, of Grennanstown, on whose ground the discovery
was made, and to whom Mr. Wilde was indebted for the
bones, and permission to make any researches he might
require.

426

Mr. Wilde concluded by impressing on the Academy the
importance of appointing persons to inquire into this and such
other objects of antiquarian interest as might, from time to
time, come to their knowledge, and thereby preserving them
to the Academy and to science; and he read a letter from Mr.
Barnwall, offering every facility to the Academy, or to any of
its members, to make further investigations into the bone-heap
at Lagore.

The thanks of the Academy were voted to Mr. Barnwall,
for his obliging offer.

Ir was Resouvep, (on the recommendation of Council,)
to omit the words in Chapter II. Sect. 5, of By-laws, fol-
lowing the words “ each candidate proposed.”

DONATIONS.

A Spear Head. Presented by Sir W. Betham.

An Examination of the Ancient Orthography of the Jews,
and of the original State of the Text of the Hebrew Bible.
By Charles W. Wall, D.D.,M.R.I.A. Presented by the
Author.

Ordnance Map of the County of Wicklow, in Forty-nine
sheets, including Title and Index. Presented by His Ex-
cellency the Lord Lieutenant.

Burgh Records of the City of Glasgow. By John Smith,
Esq. Presented by the Author.

Journal of the Franklin Institute. Vol. XXIV. for 1839.
Presented by the Society.

Proceedings of the American Philosophical Society,
Vol. I. Nos. 9 and 10. Presented by the Society.

Quarterly Journal of the Statistical Society of London,
Vol. III. Part 7. Presented by the Society.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1840. No. 23.

May 11.
SIR Ws. R. HAMILTON, LL.D., President, in the Chair.
John Davidson, Esq., James Henry Blake, Esq., Q.C.,

and Abraham Abell, Esq., were elected Members of the
Academy.

A paper was read by Jonathan Osborne, M.D., on Aris-
totle’s History of Animals :

Dr. Osborne commenced by observing, that this work
was composed under circumstances more favourable to the
acquisition of natural Knowledge than any work on the sub-
ject ever published. According to Pliny, some thousands of
men were placed at the disposal of the author, throughout
Greece and Asia,—comprising persons connected with hunt-
ing and fishing, or who had the care of cattle, fish ponds, or
apiaries,—in order that he might obtain information from all
these quarters, ne quid usquam gentium ignoraretur ab eo.
And according to Athenzus, the same prince gave him, on
account of the expenses incurred in composing it, 800 ta-
lents,—a sum, which taken at the lowest, that is, the lesser

20

428

Attic talent, amounts to above £79,000. The work composed
under such auspices, is such as might have been expected.
The extent of the observations is prodigious; and we cannot
read far in any part of it, without being constrained to ex-
claim with Cicero, Quis omnium doctior, quis acutior, quis in
rebus vel inveniendis vel judicandis acrior Aristotele ?

Shortly after the introduction of Greek literature to Eu-
rope, and when this book was first printed, those sciences
which have nature for their object, were in the lowest condi-
tion. There was at that time no taste diffused for the study of
zoology or comparative anatomy; and at later periods, when
the value of these studies came to be better appreciated, the
Aristotelian philosophy; had fallen into disuse. Thus this
work has, from this combination of circumstances, been
passed over; is seldom quoted except at second-hand ; and
no edition of it distinct from the other works of the author,
or illustrated as the subject required, has appeared since
that of Scaliger, published in 1619,—except one, accompanied
by a French translation by Camus, in 1782, which is said to
be incorrect, and is become scarce.

Dr. Osborne proceeded to make a short analysis of the
contents of this work, and showed that Aristotle had antici-
pated Dr. Jenner’s researches respecting the cuckoo, as also
some discoveries with respect to the incubated egg, which
have been published within the last year. His observations
on fish and cetaceous animals are curious in the extreme, as
might be expected from the variety of these animals abound-
‘ing in the Grecian seas. Those on insects it is difficult to ap-
preciate, from uncertainty as to the names. He describes
the economy of bees, as we have it at present; but mistakes
the sex of the queen. He holds the doctrine of spontaneous
generation in those cases, in which he could not detect the
ovary ; an inevitable conclusion arising from the want of the
microscope, to which, and the want of knowledge of pneu-
matic chemistry, his principal errors are to be referred.

429

The various organs are described as modified throughout
the different classes of animals, (beginning with Man, the
BovXevricov wovov) in nearly the same order as that after-
- wards adopted by Cuvier.

As specimens of the interesting matter treated of in the
work, Dr. Osborne selected the animal nature of sponges;
the ages of various animals ; the movements of the nautilus,
(the same doubt existing in the author’s mind as to the
origin of the shell, which has divided the opinions of Messrs.
Blainville, Owen, Gray, and Mad. Power, within the last
year;) the localities of animals, as affording data for ascer-
tainmg the rate at which they have extended themselves
over the globe; particulars relating to artificial incubatien
as practiced in Egypt ; the management of cattle ; a mode
of fattening hogs with rapidity, by commencing with a
fast of three days; the mohair goat located in Cilicia, as
at present; hybernation and migrations of various animals
and fish ; description of the fisher-fish (lophius piscatorius,)
and of the torpedo, with the proof that they catch their
prey in the extraordinary manner described; many inge-
nious modes of taking partridge, and of fishing detailed ; the
friendships which have been perpetuated between different
classes of animals,—as the trochilus and the crocodile,
the pinna muricata and the cancer pinnotheres, the crow
and the heron; their animosities, as between the crow
and owl; the diseases of animals traced throughout the
series, extending even to fish; hydrophobia described, as
being communicated by the bite of the rabid dog to all ani-
mals except man, which appears to be the correct statement
with respect to hot climates, and not (as has been re-
‘presented by some modern travellers,) an entire absence of
the disease.

These detached specimens of the contents of this work fur-
nish, however, a very inadequate idea of its real value. There
are in it whole sections, the separate sentences of which,

202

430

would furnish texts for as many Bridgewater Treatises. The
freshness and originality of the observations taken from na-
ture herself, and not made up from quotations of preceding
writers ; the extent of the views, not bounded by any neces-
sity for complying with preconceived or prevalent notions,
but capacious as the author’s mind itself, and frequently
leading the reader into the most interesting under-currents
of thought branching off from the great fountain ; these are
all merits belonging to the work, but not constituting its chief
value,—which is, that it is a collection of facts, observed
under peculiar advantages, such as have never since oc-

_eurred, and that it is at the present day to be consulted for
new discoveries.

Now that Greece is, for the first time since the revival of
letters, in possession of a government capable of apprecia-
ting scientific investigations, a favourable opportunity offers
for preparing an edition of the work, at once worthy of the
age in which it was composed, and of that in which we live ;
and perhaps some individual may be found, possessing a
competent knowledge of the Greek language, and of zoology
and comparative anatomy, who, after a sufficient examina-
tion of the animals now in Greece, shall undertake the task
of editing and illustrating this great work. Such a perfor-
mance, properly executed, would be the resuscitation of a
body of knowledge, which has lain buried for above 2000
years ; and would certainly be no less acceptable to zoologists
and anatomists than to the cultivators of classical learning.

The Rev. Dr. Todd exhibited to the Academy a gold
ring, the property of William Farren, Esq., which was re-
ceived in barter, from the natives of the western coast of
Africa. The similarity of the twist in this ring to that of
the gold torques found at Tara, and recently presented to
the Academy, renders it extremely worthy of attention.
The following extract of a letter from Mr. Weston, of Lon-

431

don, by whom the gold ring was presented to Mr. Farren,
and which is addressed to that gentleman, was read to the
meeting :—

London, March 31st, 1840.

‘Tn reference to the African gold, or torque as you call it, a
young correspondent of mine, resident at Sierra-Leone, and a mer-
chant there, happens to be at this time in London; from him and
his father I have received many boxes of this pure gold, and he
has furnished me with his own information upon the subject,
which I send you inclosed; he tells me there are large rings or
torques, full the size of those I saw in the library of the Royal Irish
Academy. Recollect the inclosed is written by a man of colour, and
an African by birth, educated in England under my care, and now
a resident in his own country. By this, you will see what some
of these men are capable of.

“I have written to Africa, and desired a large ring may be
procured for you ; I have no doubt this discovery may throw some
new light, as to the existence of a connexion in early days be-
tween Africa and Ireland.”

The following is the letter from the African gentleman
alluded to by Mr. Weston :—

aaa “ 31st March, 1840.
“* My dear Sir,

“In answer to your inquiries relative to the gold rings that are
generally sent from Sierra-Leone, I must first candidly explain
that what little information I may be able to afford, has been de-
rived from the gold strangers or traders that visit the colony, and
not from any personal intimacy with the places where the gold is
procured.

“The gold out of which these rings are ¢7visted, is found in
the countries of Seral-Doolley, Timbuctoo, Seran-Colley, Follah,
Bondou, Kasson, Kaarta, Bambarra, and Timbo, all of which tribes
are distant about 1400 miles from, (in latitude 15° N.) and visit
Sierra-Leone, in hoards of from two to four and five hundred at a

432

time, travelling generally on foot; these journeys take them from
two to four months, and equally long to return to their homes.
They are all of the Mahomedan persuasion, and proficient Arabic
scholars. Their manners are easy and insinuating ; and in conver-
sation, which is always (or generally) done through an interpreter,
they are full of compliments and flattery. Agreeably to the Maho-
medan creed, they use no liquor, wine, or beer of any kind, (not
even ginger beer,) and drink exclusively water, or sugar and water,
They are, for the most part, very uncleanly in their habits, and par-
ticularly so in their dress—oftentimes wearing one apparel without
ever taking it off to cleanse their bodies the whole time they are
away from home ; their clothes are consequently almost in rags be-
fore they put on new ones.

“* The gold is found in veins, and dug up in a solid substance,
resembling the fine roots of trees. It is then purified by a mere
melting process, in crucibles, so as to separate the earthy portion
from the metal itself. The Africans are not capable of amalgama-
ting the gold, this is left for the refiners in England to do.

“In some of the countries already mentioned,—Bondou and
Timbo, more particularly,—they sweep out their huts every morn-
ing, the floors of which are mud; and no person is permitted to stir _
out until this office is performed. In the dust they sweep up, a little
gold is mixed. They then wash the whole in vessels for the purpose,
and the gold naturally sinking to the bottom, is thus separated, and
obtained in small quantities. The twisting is accomplished by
holding both ends of a solid piece of gold between nippers, and
then turning it round until it assumes the appearance in which it is
imported, being exceedingly ductile ; this is not a tedious process.
The rings thus twisted, are sometimes from ¢mwelve to fifteen inches
in circumference, and weighing about fourteen ounces. I however
have heard, that they are made much longer and heavier ; but these
are not, to my knowledge, parted with in the way of trade, but
worn as ornaments round the neck and arms.

“Tn the interior, all transactions are carried on for gold, the
trader being furnished with a pair of scales made of the hard outer
skin of the orange gourd. The weights are the seeds of certain vege-
tables or fruits. They thus pay in gold from two pence to £10, and

433

upwards. This I have often seen, and proved their exactness by
weighing the same pieces in English scales.

“Gold is also found in Central Nigritia, and on the Guinea
coast; this I believe is principally in dust, and obtained by the
same method of washing.

‘<I have seen a piece of gold in its natural rough state ; it was a
solid piece, about five inches long, and of the thickness of a com-
mon writing quill. It was smooth in appearance, but seemingly
composed of a number of layers, compressed together by a natural
mechanical force, with veins like the grain of wood from the root
of a tree.

‘* Tn the countries I have here alluded to, the natives cultivate
farms, but in a very careless and rough manner, merely cutting
down the trees, but never rooting up the stumps or clearing away
the smaller plants, but plant the rice or cassava negligently among
the whole of this stubble, waiting till the rice, &c. may grow, to
distinguish one from the other. They never sow or make use of
the same farm a second time; but the soil is excessively sterile and
sandy. Domestic poultry is plentiful; also sheep, and other
horned cattle. They take great care of their cows, milk forming
a principal luxury in their daily diet.

“The gold strangers invariably visit Sierra~Leone, accompanied
by several slaves, who bring ivory and other articles for barter.
They all represent the countries from which they come, as possess-
ing plenty of gold, but no facilities for procuring it.

“« Salt is considered a great luxury in the interior of Africa, and
eagerly sought after in trading.

“IT remain, my dear Sir,
‘¢ Yours, assuredly,

““W. GABBIDON.”

The Rev. H. Lloyd, V.P., read the following communica-
tion by Dr. Apjohn, on the value of the numerical coefficient,
in the formula for the force of aqueous vapour in the at-
mosphere, as derived from the observations of the wet and
dry thermometers.

434

“If ¢ and ¢’ be the temperatures shown by a dry and wet
thermometer, encompassed by atmospherical air, ¢” the dew-
point, f’ and f” the forces of aqueous vapour at ¢’ and ¢”,
and p the existing pressure,—I have shown (Trans. R. I.
Academy, vol. xvii., p. 285,) that

es tt P is
rae ae

‘In investigating this expression, it is assumed that the
specific heat of air, and the caloric of elasticity of aqueous
vapour, are constant, and represented (within the ordinary
variations of atmospheric temperature and pressure,) the
former by . 267, the latter by 1115. In subsequently apply-
ing this expression to the determination of the specific heats
of the gases, (Trans. R. I. Academy, vol. xviii.) it was ne-
cessary to give it its most general form, when it was found
to become

48a (t—t —f’
a being the specific heat of air, and e the latent heat of
aqueous vapour, both being supposed at the temperature
represented by ¢’, and under the pressure p. I shall here
briefly indicate the steps which conduct to this result.
They are given at length in the Philosophical Magazine, for
October, 1838.

“The two following propositions constitute the basis of
the investigation :

« Ist. When, in the case of the wet thermometer, the
stationary temperature is attained, the caloric which vapo-
rizes the water, is necessarily equal to that which the sur-
sounding gas evolves in descending through ¢ — ¢’ degrees,
2. e. from the proper temperature of the air to that of the
moistened bulb. ;

“2dly. The air so cooled, by successive contacts with
the moistened bulb, is saturated with humidity.

“From these propositions we easily deduce the equation

435

ee me’

f' =f 1€ aa (I)
in which m’ represents the amount of vapour formed by the
caloric’extricated from a given volume of air, in cooling
through ¢ — /’ degrees; and m the maximum amount of va-
pour, which the same volume of air could contain at ¢’. In
this expression /’ may be considered as known, the corres-
ponding temperature ¢’ being the result of observation. In
order, therefore, to render the formula available, it is only
necessary to determine in known terms the values of m’

and m.
“‘ If a be the specific heat of air, and e the caloric of elasti-

city of aqueous vapour at the temperature ¢’, it is easy to see
e : es :
that G grains of air, in cooling through ¢ — ¢’ degrees, evolve

sufficient heat to vaporize exactly ¢ — ¢’ grains of mois-
ture. For m’, therefore, in the formula just given, ¢— ¢’
may be substituted.. Again, m may obviously be replaced
by the maximum amount of moisture capable of being con-

4 AG ; ;
tained in — grains of air at the temperature i’ and pressure p.
a

But to obtain this, it is only necessary to reduce - grains of
air to cubic inches; to multiply the resulting volume by
_/ _ * in order to get the expansive effect of moisture ;
gee

and finally multiply the volume thus obtained by the weight

of a single cubic inch of aqueous vapour. When this is done,
£/
we find m = °625 x fy —-—. Reverting now to equa-
Gx Bese

pp ing subs ton 0 Sak Eh en aoe ES

* In the investigation given in the Philosophical Magazine, this step is omitted.
The omission, however, does not sensibly affect the accuracy of the resulting

formula.

436

tion (1), and writing in it the values just found for m/
and m, we arrive at the final equation
“a 48 a(t—t) p—f’

P ajo ee a)
in which the force of vapour at the dew-point is expressed
in terms of the force of vapour at ¢’, and of the difference
of the temperatures of the wet and dry thermometers.

“This formula is applicable for all vaiues of ¢’ above 32° ;
but when the stationary temperature of the wet thermometer
is lower than the freezing point, it will require modification.

Cont : : :
7 stains of air, we have seen, in cooling through ¢ — ¢’

degrees, convert into vapour ¢ — ¢’ grains of moisture. But
if ¢’ be less than 32°, a greater amount of air will be neces-
sary for accomplishing this, inasmuch as the heat evolved
has first to liquify ice, and then to convert the water jinto
vapour. The additional quantity is obviously represented
ae aH 135 being the caloric of liquidity
of water, and 1179 — ?’ the latent heat of aqueous vapour at
t’. But this fraction, if we substitute 32° for ¢’, (which may
be always done without sensible error) is equal to 0-118.

Hence for values of ¢’ below 32°, - + 0-118 < = 1-118 =

by the fraction

is, in grains, the weight of air which, in cooling through
i — t’ degrees, vaporizes ¢—¢’ grains of moisture. When
this correction is applied, the final equation, applicable to
observations in which the wet thermometer indicates lower
temperatures than 32°, becomes
,__ 4 a(t—?’) g
rsp — SS) yet (mm

** Assuming, as before, the specific heat of air, a, to be
‘267, the value assigned to it by Delaroche and Berard,
and taking for e the value it would have at 50°, upon the hy-
pothesis that 967° is the latent heat of vapour at 212°, and

437

that the sum of its sensible and latent heat is at every tem-
perature a constant quantity,—equation (II) becomes

fl =f’ - 01185 ¢— 1) x2@SL, (IV)
and equation (III) becomes
Sf’ =f’ — 01017 — t) x 2 a : (V)

“The theory which has led to these conclusions is now
universally admitted to be correct; but as doubts may -
be entertained respecting the exactness of the coefficient,
whose value, as has been seen, depends on the numbers by
which a and e are represented, (numbers which are, in all
probability, not as yet known with great precision,) it would
appear desirable to deduce its value directly from experi-
ment. This is the immediate object of the present commu-
nication.

“In my second paper on the dew-point, I have given three
distinct series of experiments, applicable to such a purpose ;—
the first relating to air whose dew-point was determined by
Daniell’s instrument; the second to air perfectly dry; and
the third to air whose dew-point is known with certainty,
and without the aid of any form of condensation hygrome-
ter. From these, in all of which ¢’ is greater than 32°, I
have calculated 54 values of the coefficient, by methods to
the explanation of which I now proceed.

©], Representing the coefficient in question by m, the
hygrometric formula becomes

/

Y Tif ace Oey, P =e

f' =f —mt-t)xX 307°
Now if air, in reference to which ¢ and é’ have been accu-
rately noted, be raised to any higher temperature, and the ob-
servation repeated, we obtain data for determining the value
= Hi if

Pp 30? for

of m. For,” being constant, f’ — m (t —?t’) x

; ; pP—F
one observation, will be equal to r’ — m(t—T’) X a0

438

for another, from which we deduce
a alc aUNA
_@=@- 20) eae
“ The subjoined tables contain the experiments ; and ap-
plying to them the method of calculation just explained, we
obtain eleven values of m.

SERIES 1.
TABLE 1.
No.| ¢ ft 1t—@| p
1 | 49°6 | 44:7 4:9 | 296 ? 1&2. m= ‘0118
2 | 88:5 | 62 26°5 | 29°6 MSc Oe cee - ‘0121
3) 805 |59 | 215 |206 | foe3 12127 0110

1 | 47-2 | 42°5 4-7 | 30:02 Be
2 | 76 57-5 | 18:5 | 30-02 bie. m= -0144

TABLE 3.

No.| ¢ t. 16 — ep L& 2. m= Old
| ——_—|—___|___ DRS Sete care 0122
1 | 48:3 | 43 5:3 | 29°76 RE eke lore 0132
2 | 96 64 32 29:76 2&3 20... 0035.
3} 91 62°5 | 28°5 | 29°76 | 2&4...... 0103
4| 75 56 18 29:76, ,3&4...... 0109

TABLE 4.

No.| ¢ Bt 8p

1| 51°3 | 45-5 | 5:8 | 30:7 | . ae
2'\'8a) >| Boot bes Me is0.7 \iaaNet 770 aye

Mean value of m = ‘01151
“2. In the general formula given above, if f” = 0,

3 : 3
m= ——, X =F . My observations of ¢ and é’ in dry

439

air, which I here subjoin, enabled me, by means of this ex-
pression, to calculate 19 additional values of m.

SEeRtiges 2.

No. t uo|t—t| p m ~
1 51 33°5 | 17:5 | 30°55 | -0122
2 53 345 | 18°5 | 30°35] -0116
3 52 34 18 30°21 | +0118
4 dl 33 18 30°05 | °0115
9) 52 33°4 | 186 | 29°75} 0108
6 53 343 | 18-7 | 29°50} °0118
7 56°5 | 35°8 | 20°7 | 29-70 | °0112
8 58 37 21 29°72 | :0110
9 58:2 | 37 21:2 | 29°77 | :0113

10 58 37 21 30°03 | °0114
11 58 37 21 30°15 | °0113
12 59 37°5 | 21°5 | 30°25} °0112
13 39 38 21 30°26 | °0117
14 61 38:7 | 22°3 | 30°21 | ‘0113
15 58°3 | 37:7 | 20°6 | 80°35 | °0117
16 58 37:5 | 20°5 | 30-45 | °0117
17 56:3 | 36°5 | 19°8 | 30°30} -0117
18 57° | 37 20°5 | 30°20| -0116
19 07'S | 37 20°5 | 30°15] -0116

Mean. = ‘01150

“3. Lastly, if in the formula f” and f’ be known, so also
LS x a. Batam
a alah aaah pe
the case of air saturated with humidity, by being passed
through water, its temperature is its dew-point; so that this
latter is easily and certainly known. Hence, if the tempera-
ture of such air be raised, and a wet and dry thermometer
be observed in it, we have ¢, ¢’ and ¢”; and can therefore, by
the expression just given, calculate the value of m. The
following table includes 24 distinct observations, from which
the values of the coefficient given in the last column have
been thus deduced:

is m, for it is obviously equal to

440

SERIES 3.

No.| ¢ | t'’ |t—@f| p zt m
1| 78 | 62-2 | 15-8 | 30°30| 51:3 | -0110
2|76 | 61:5 | 14-5 |30:30| 51-3 | -O111
3|73 | 60-3 | 12:7 | 30:30! 51-3 | -0108
4|72 | 60. |12 |30-30| 51-3 | -0118
5/69 | 586 | 10-4 |30-30| 51°3 | -0106
6
7
8
9

90°5 | 67 23°5 | 30°15 | 50°8 | ‘0119
§2°2 | 64:3 | 17°9 | 30715] 50°9 | -0123
79 82 17 30°15 | 50°9 | :0110
71°7 | 60 11°7 | 30°15 | 51:2 | -0116
10 | 69 58:9 | 10°1 | 30°15] 51:5 | :0112
11 | 92 69 23 30°42 | 51‘1 0120
12 | 83 65°38 | 17:2 | 30°42 | 54:5 | -0116
13 | 76 63°3 | 12°7 | 30-42 | 54:9 | °0113
14 | 68 60°3 77 | 30°42 | 55 "0112
15 | 98°5 | 71:5 | 27 30°36 | 55:5 | :0117-
16 | 84:6 | 67 17°6 | 30°36 | 56 0115
17 | 77°35 | 64:5 | 13 30°36 | 56°3 | -0112 |
18 | 81 62:2 8°8 | 30°36} 56°5 | ‘0111
19.| 83 66°5 | 16°5 | 30°51 | 56:8 | -0108
20 | 77 65 12° | 30°51 | 57-2 | -0117
21 | 71:3 | 68 83 | 30°51 | 57°5 | -0116
22 | 91°8 | 68-6 | 23:2 | 30°51 | 54°1 "0115
23 | 75°2 | 63:2 | 12 30°51 | 55 0116
24 | 72 62° 10 30°51 | 55:1 0115

Mean = -01140

‘‘ The following, therefore, are the means deducible from
each separate series of observations :
Series]. .: m= ‘01151
Series Qi: . se 10.6, ,O1150
Series3...... ‘01140

3 1
So that the mean of all three is :01147 = e719? OF al-

most exactly the coefficient which I have sake in my
papers on the dew-point.”

Mr. Lloyd then proceeded to offer some remarks upon
Dr. Apjohn’s communication, and upon the most probable
value of the coefficient to be derived from his results.

441

We have here, he said, the results of three distinct series
of experiments, conducted upon different principles, and by
different processes ; and, as we observe, the mean values of the
coefficient thus deduced present the most complete agree-
ment, the greatest difference amounting only to ‘00011. Itis
almost indifferent under these circumstances, which of these
results be adopted; but in order to do complete justice to
the subject, we shall here investigate the most probable value
of the final mean, as given by the calculus of probabilities.

In order to do this, it is necessary to deduce, in the first
instance, the probable error of each mean, as derived from
the results of its own series. This error, it is well known,
is expressed by the formula

_ 455 3 («x — a)?

~ n(m—1) ’
in which & (« — a)? denotes the sum of the squares of the
differences of each partial result and the mean, and the
number of observations. The results of this calculation are
given in the last column of the annexed Table.

Series. n m E
1 11 01151 ‘00031
2 19 °01150 “00005
3 24 ‘01140 “00006

The most probable value of the final mean, will now be
given by the formula

my, Mz M3
mee

rn 1 i?
pu WEE

from which we find m = ‘01145.

In the preceding deduction we have supposed that the
only errors to which the separate values of m are liable are
the errors of observation, in which case the positive and -

442

negative errors would be equally probable. But there is
another class of errors involved, belonging to the Tables of
the elastic force of vapour at different temperatures. In
fact, the value of m being expressed in terms of f, and f
being calculated from the observed value of ¢, by these
Tables, it is obvious that the errors of the Tables will affect
the result. In this point of view, however, there is a very
important difference between the second series of experi-
ments and the other two. The values of m, in the first and
third series, are expressed in terms of the difference of two
values of f ; so that any constané error, in the Tables which
give the values of f, must wholly disappear in the result ;
and any error nearly constant must, for the same reason, be
nearly evanescent. The case is different, however, in the
second series. Here m is expressed in terms of a single
value of f; and the tabular error of that value has therefore
its full effect. Now, that the errors of the Tables are
of the kind alluded to,—i.e. nearly constant within certain
moderate limits of temperature,—will be evident from the
mode in which they are constructed. The value of f is
in all cases calculated from an empirical formula, which
(within the ordinary range of temperature) does not vary
rapidly with moderate changes of ¢; the error in the value
of f, therefore, (i. e. the difference between its value as cal-
culated with the asswmed and with the ¢rwe formula,) may,
therefore, be regarded as nearly the same, for a moderate
range of the variable on which it depends.

It follows from this, that, in the second series, the true
probable error is greater than that deduced from the obser-
vations themselves, and is the resultant of that error and
of the error of the Tables. If this latter error were known
@ priori, the resultant error could be inferred; but as this
is not the case, we have no means of knowing the weight
due to the result of that series, and have, therefore, no rule
to guide us in combining that result with the other two.

443

We are thus compelled in strictness to omit that result alto-
gether in deducing the final mean. Combining, therefore, the
results of the first and third series, according to the method
already laid down, we have

m = .01140 ;

a result which is identical with that of the third series, that
of the first, (on account of its large probable error) not
affecting the fifth place of decimals.*

But the second series of experiments, though it cannot
properly be combined with the others in deducing the mean,
may yet serve another purpose. It may be made, in fact,
a test of the accuracy of the different tables of the elastic
force of vapour, within the range of temperature belonging
to the experiments. With this view, the values of the co-
efficient, m, have been calculated by Dr. Apjohn from his
second series of experiments, by means of three separate
tables of the elastic force of vapour: The first of these
tables is that which has been employed above, as well as in
his papers on the Wet Bulb Hygrometer in the Transactions
of the Academy, and is that calculated by Dr. Anderson
from the experiments of Dalton and Ure. The second
table is that deduced by Mr. Kamtz, from his own experi-
ments; and the third is that given in the Report of the
Committee of Physics and Meteorology of the Royal Society,
and calculated by Mr. Lubbock from a formula of his own.
The results are given in the annexed table.

ES EE Eee

* The errors of observation in the first series, which are so considerable in
comparison with those of the other two, are manifestly owing to the mode of ob-
serving f”. For it is obvious that the rapidly varying temperature of the thermo-
meter in the condensation hygrometer cannot be noted ata precise instant, with
the same certainty as that of a thermometer which has arrived at a stationary
temperature.

4A4

No. | Anderson.| Kamtz. Lubbock.
1 ‘0122 ‘0108 ‘0110
2 ‘0116 0107 ‘0109
3 ‘0118 ‘0107 ‘0110
4 ‘O115 ‘0104 "0107

- 5 0108 0104 ‘0107.
6 ‘0118 ‘0107 0110

7 ‘0112 ‘0102 0105

8 ‘0110 ‘0105 0108

9 ‘0113 ‘0104 ‘0107

10 ‘0114 ‘0104 ‘0107

11 0113 0104 0107

12 "0112 ‘0103 ‘0107

13 ‘O117 ‘0107 O11]

14 ‘01138 ‘0104 ‘0107

15 ‘O117 ‘0108 ‘0110

16 | ‘0117 ‘0107 ‘0110

17 0117 ‘0108 ‘O111

18 ‘0116 ‘0106 -0109

19 ‘0116 ‘0107 ‘0109

Mean = -01150 ‘01055 01084

It will be remarked at once, on the inspection of these
numbers, that the differences of the corresponding results
for the same experiment, as well as those of the means, are
considerably greater than those of different results, as cal-
culated by the same table: plainly proving that the error
due to the imperfection of the tables is greater than the
error arising from observation. If we now take the diffe-
rences between the mean values of m according to each
table, and the final mean already obtained, we find that the
error in the value of m deduced from the first table is only
+ .00010. The same error, in the case of the second table,
is — .00085; and in that of the third, — .00056. The pro-
bable difference, supposing the partial means to be affected
only by the errors of observation, is less than .00008. We
have reason to conclude, therefore, that the second and.
third of these tables are not so correct as the first—at least
for temperatures corresponding to those of the thermometer

445

with the wettened bulb in these experiments; and that the
values which they give for the elastic force of vapour, for
these temperatures, are too low.

(Additional Note by Dr. Apjohn.)

““M. Kupffer has recently been engaged in discussing the
value of m, the coefficient in the hygrometric formula. Ina
note read by him at the Petersburgh Academy, on the 22nd
of last January, and published in the Bulletin Scientifique,
No. 132, after a detailed examination of the experiments
of August, Gay-Lussac, Erman, Bohnenberger, and
Kamtz, he comes to the conclusion, that the theoretic value

48

a : A
of m, or » agrees sufficiently well with that deduced

from the most trust-worthy comparative observations on
the dew-point. The formula which he definitively adopts, is

SJ =f — 267 (¢ —?@);
Jf’ and f” being expressed in tenths of an English inch, and
¢ and ¢’ in degrees of Reaumur’s thermometer. But this, ex-
pressing f’ and f” in inches, and ¢ and 2’ in degrees of Fah-
renheit’s scale, becomes
SJ’ =f — 01142 ¢ — #’);
an expression in which the coefficient is almost identical with
that which has been deduced above from the three series
of experiments to which I have so often referred. This for-
mula, however, M. Kupffer observes, gives results in ac-
cordance with direct observation, only when the table of the
elastic force of vapour drawn up by Kamtz is employed;
from which he infers, that #¢ alone represents with accuracy
the relation between the tension and the temperature of
steam—an opinion from which, notwithstanding the high
authority of M. Kupffer, Iam compelled to differ, on the
grounds already stated by Professor Lloyd.
“‘ There is another statement of less importance made by,

{

446

M. Kupffer, to which also I find it impossible to assent.
He alleges that the dew-point obtained directly by Daniell’s
hygrometer is always lower than the truth; and he as-
cribes this to the bad conducting power of glass, by reason
of which the opposite surfaces of the ball containing the
thermometer will, while refrigeration is proceeding, have
different temperatures, so that when the outer surface has a
dew deposited on it, the temperature of the inner surface,
and that of the ether in contact with it, are sensibly lower.
I do not deny that, theoretically speaking, this must be the
case; but I certainly doubt much whether the cause assigned
can produce any appreciable effect of the kind attributed to
it. On the contrary, according to my experience, the ob-
served is almost invariably higher than the true dew-point.
Such must inevitably be the case when the ether is
poured on too rapidly ; for we have thus a local reduction of
temperature at the surface of the ether in the ball containing
the thermometer, considerably greater than that indicated
by the instrument, as ¢¢ merely shows the mean temperature
of the entire column of fluid in which its bulb is immersed.
In fact, I have frequently observed, under such circum-
stances, a ring of dew to be formed, for example, at 44°,
and to disappear subsequently, though the temperature of
the inner thermometer was kept steadily at this point, or
even carried lower,—showing clearly that partial deposition
may take place before the true dew-point is attained. The
only mode of avoiding this is to pour on the ether very
slowly, so as to produce such a gradual lowering of the
included thermometer, that the entire of the ether in which
it is immersed shall have, at each instant, a temperature which
may be considered uniform throughout. As another cause
why the observed dew-point is higher than the true, I may
mention the augmentation of the humidity of the air in the
vicinity of the instrument, by the pulmonary halitus and
cutaneous perspiration of the observer ; a cause which must

447

‘be admitted to exercise a sensible influence, when it is
considered how close the observer must be to the instru-
ment, and what a considerable length of time is generally
necessary for an observation.

*“ While upon this subject I may observe that Professor
Daniell’s rule,—to take as the dew-point the arithmetic mean
between the temperatures indicated by the included thermo-
meter, at the moment of the deposition of the ring of moisture,
and at the instant of its disappearance, appears to me to be
erroneous. I have just assigned the reasons which induce me
to conclude that the former temperature is (at least in most
instances) above the truth; and it is obvious that the latter
must always be on the same side, for evaporation cannot com-
mence until the temperature of the ball reaches the point of
deposition, and will therefore not be completed until it has
actually got above this point. The observed results, there-
fore, being both above the true dew-point, so also will be
the mean itself.

‘“‘ There is one other topic, suggested by a perusal of M.
Kupffer’s note, to which I am anxious to advert. Upon
ordinary occasions the dew-point formula may be used with-

out the factor © = by which it becomes

f =f — Oli €— 7%).
This is the form to which it is reduced by M. Kupffer; and
though not rigorously exact, the error is generally negligible,
within the ordinary variations of atmospheric temperature
and pressure. In the case of observations on high mountains,
however, it will be indispensable to employ the complete
formula, otherwise the calculated dew-point would be appre-
ciably lower than the truth. In illustration of this point, I
subjoin the particulars of an observation made on the Sugar-
loaf mountain in the vicinity of Bray, the dew-point being
experimentally determined by Daniell’s hygrometer, and

448

calculated by my formula, in its complete and less perfect
form, from the observed temperatures of a wet and dry

thermometer.
(Top of Sugar-loaf, April 23, 1840.)
“t= 60°87 Sos FS 16 Fp coe
t’’ (by Daniell’s hygrometer) = 47.5.
tY (by formula f’= f’ — ‘6114 (¢ — 7’) x = = 46°°8.
t” (by formula f’” = f’ — 0114 (¢ — ¢/) ) = 46°-22.
P — which, in the pre-

ceding observation, = ‘9366, the calculated dew-point comes

* Thus, by neglecting the factor

out 0°°58 too low. This, however, may, under ordinary
circumstances, be considered as an extreme error; for ¢—?’

Dis
30

is seldom so high as 7:6, and scarcely ever so low as

9366, at least in this climate.”

May 29.
REV. H. LLOYD, A.M., Vice-President, in the Chair.

A paper was read by the Secretary, being a continuation
of Mr. George J. Knox’s researches “ on the Direction and
Mode of Propagation of the Electric Force, and on the
Source of Electrical Development.”

In the commencement of this paper the Author describes
some experiments, from which he concludes that all fluids
convey the electric force through their substance; while
with regard to solzds no regular law exists, some conveying
the electric force through their substance, while others con-
vey it along their surface. He next considers the source of
electrical development, and shows that it must originate in

449

contact, and not in chemical action, by a reference to experi-
ments which prove that there is development of electricity
by contact where chemical action could not take place, (as in
the case of gold and platinum,) and by showing that all the
experiments adduced in favour of chemical action, receive
an easy solution on the contact theory. He then shows
how completely the electrical machine illustrates every ano-
malous action in the voltaic pile, when the contact theory,
and his explanation of chemical action by alternate states of
induction and equilibrium, are adopted.

The Author then explains, (as a further proof of the cor-
rectness of his theory of alternate states of induction and
equilibrium,) in what manner, according to this theory, a
current of electricity must, at making and breaking contact,
produce induced currents in opposite directions; and he
concludes with a few remarks upon magnetism considered
as an electrical phenomenon. :

The Rev. Dr. Todd announced to the Academy that
the transcript of the Book of Lismore, borrowed some time
ago by the Council from his Grace the Duke of Devonshire,
was now completed; and he exhibited it, together with the
original, to the meeting.

After some remarks on the beauty of the transcript,
which was made by Mr.'EKugene Curry, and the means
taken to secure its accuracy, Dr. Todd proceeded to give
some account of the original MS.; the circumstances under
which it was discovered in the Castle of Lismore, in 1814;
and its subsequent history. He showed that it received the
name of “the Book of Lismore” merely because it happened
to be found in that Castle, and that it had no connexion
with the Church of Lismore, as the appellation of Book of
Lismore would imply. It was written probably for some
members of the Mac Carthy family, and was a sort of Bzbli-
otheca, or collection of tracts on all such subjects as appeared

450

interesting in religion, legendary lore, and history, in the
fourteenth century, at which period the book was most pro-
bably written.

After describing the various mutilations which the volume
appears to have sustained, Dr. Todd proceeded to describe
its contents, and to make some remarks on the sources of
the different tracts contained in it. These are, Lives of
St. Patrick, St. Columkille, St. Bridget of Kildare, St. Senan
of Scattery Island, St. Finnen of Clonard, and St. Finnchua
of Brigown, all in Irish of great purity and antiquity; the
conquests of Charlemagne, taken from the celebrated ro-
mance of the middle ages, falsely attributed to Tilpin, or
_ Turpin, Archbishop of Rheims; several legends, as the
story of All-hallowtide, of Antichrist, of St. Canice of Agh-
aboe, of David and Solomon, of a Christian and a Jewish
Child, of St. Comgal of Bangor; and the history of the Lom-
bards, from the celebrated work of Paul Warnefrid. Of this
latter tract, which is full of strange tales and legends, Dr.
Todd read a short portion, in an English translation. The
reading of the remainder of the paper was deferred to the
next meeting of the Academy.

DONATIONS.

Annales des Mines. Par les Ingenieurs des Mines.
Troisiéme Série. Tome VII.—X. Ttepented by the School
of Mines.

Journal of the Franklin Institute. Vol. XXIV. for 1839.
Presented by the Society.

Asiatic Researches. Vol. XIX., Part 2. Presented by
the Asiatic Society of Calcutta.

Flora Batava. By Jan Kops. Presented by the Author.

Fisher's Constantinople. Presented by Rey. R. Walsh,
LL.D., M.R.LA.

PROCEEDINGS

OF

THE ROYAL IRISH ACADEMY.

1840. No. 24.

June 8.
SIR Wm. R. HAMILTON, LL.D., President, in the Chair.

George Wilkinson, Esq., and G. Willoughby Hemans,
Esq., were elected Members of the Academy.

The following note, by John Ball, Esq., M.R.LA., on
the Aurora of the 24th of April, was read by the Secretary:

“It being possible that a very brilliant Aurora, which oc-
curred on the night of Friday, April 24, may have been the
subject of observation in different parts of the country, I

offer the following notes, taken at the time, as a contribution
to the facts which it is so desirable to collect together, in re-
ference to these phenomena. Being unprovided with in-
struments, the only point of interest which I was able to
attend to was the period at which the more observable
- rapid changes took place. To fix the position of such changes,
it would have been desirable to note their exact direction
by the compass, which might be done where there are seve-
ral observers ; but my whole attention being directed to the
time, I was unable to effect this. To supply as far as pos-
sible the deficiency, I have endeavoured, by rude outlines,
2a

452

to represent some of the remarkable appearances, the period
of whose occurrence IJ have noted down; and these will pro-
bably enable other observers to recognize the changes suffi-
ciently to allow of a comparison of the observed period of
their occurrence.

‘«‘The time given is, as accurately as I could ascertain it,
Liverpool mean time, which, of course, may easily be re-
duced to Greenwich or Dublin time, by persons anxious to
compare their observations.

** Before 10 o’clock, p.m., I remarked a bank of light in
the northern horizon, which gradually assumed the form of a
very well defined arch, the luminous part being of less
breadth than is usually the case. The arch continued slowly
torise, without exhibiting any appearance of streamers, un-
til some minutes past ten, p.m., when the altitude of its up-
per surface may have been about 10°; it then began to exhi-
bit an appearance resembling the glow above a furnace, and
at 10" 10™ 8* a very brilliant streamer ascended from a lit-
tle to the east of the centre of the arch.

‘The phenomena of streamers were now, for some mi-
nutes, exhibited with great brilliancy. At 10° 12™ 495, a
broad column of bright light was seen’ about the centre of
the arch, as in the subjoined sketch. ;

“Up to this time the arch had preserved its regular form;
but a separation now gradually took place, the bow seeming
as if broken in the middle, and the eastern side remaining

453

throughout the most brilliant. The changes now succeeded
each other so rapidly as to defy observation, the limits of the

dark interior part continually altering, and at one time ap-
pearing as ifhalf the arch were refracted from its place.

‘The arch continued to separate, and, as it were, fall to
pieces, the streamers diminishing in brilliancy until 10" 17™ 58,
when a broad column rose from very near the horizon, on

the eastern side.

|
|

y

Mit

“This column appeared gradually to melt away, when

a yery brilliant streamer arose de) in the same place at
2Q ;

454

10° 17™ 53s, remaining fixed for a few moments; at 10" 18™ 12°
this resolved itself into several bright streamers. I was un-
able, after this period, to fix upon any sufficiently marked
appearances to admit of being noted down; the Aurora, how-
ever, continued for some time longer, till gradually obscured
by a thick fog which came on at this time. Throughout
the whole period, the dark part, through which I observed
stars of the fifth magnitude, was remarkably well defined,
presenting at times the appearance of a mountain range
seen at a distance. i

‘T have offered this very imperfect sketch, in the hope that
this fine Aurora has not escaped the notice of more accurate
and better prepared observers; for, if we were supplied
with a sufficient number even of such rough outlines as the
preceding, we should be better enabled to answer a question
very important to the subject, namely—whether different
observers see the same Aurora at the same time 2?”

Dr. Robinson presented a specimen of Meteor Paper,
similar to that of Carolath, which he had received from the
Countess of Caledon, with a notice of the circumstances of
its formation. It was found, last Spring, covering a consi-
derable tract of meadow land, the property of Lord Radnor,
in Gloucestershire. The tract of country between Les-
blade and Farringdon is flooded by the Isis every Spring,
but not more than usually this season. When the waters
subsided, the surface of the ground was covered with this
substance to such an extent as to make its removal and de-
struction necessary to permit the growth of the grass; some
of the pieces covering ten and twelve acres in continuous and
unbroken sheets. Nothing of the kind had been noticed be-
fore by the oldest farmers. Portions of it were found on land
which had not been under water. It is denser than any which
Dr. Robinson had seen, and contains a larger proportion of
the shields of Infusoria; but the tissue is composed chiefly
of the conferva rivularis.

455

Mr. Farran exhibited to the Academy a Babylonian brick,
with cuneiform characters.

Rev. H. Lloyd, V.P., read the following extract ofa letter
from the Rev. Thomas Knox, accompanying a tabular view
of the results of rain-guages observed at Toomavara, County
of Tipperary, by himself, and at Monks Eleigh, Suffolk, by
the Rev. Henry B. Knox, during the year 1839; together
with plates of the rain curves.

** River Glebe, Nenagh, May 28, 1840.

* T send the combined results, for the year 1839, ofa rain
gauge kept by my cousin Henry and of my own; they are
made on the same principle and construction as that of which
I sent the previous account. As Toomavara is about forty
miles from the west coast of Ireland, and Monks Eleigh, in
Suffolk, (where my cousin Henry resides,) about a similar
distance from the east coast of England, we think the
comparative view of the direction and amount of rain may,
perhaps, prove interesting to the Academy.

*‘ There are a few points to which we wish to draw more
particular attention: In the first place, there is a striking re-
semblance between the mean curve of the twelve months,
and that from Winter to Summer solstice at each place
respectively, so that the latter nearly represents the na-
ture of the yearly rain of the place—I mean with regard to
the point of the compass from which it comes; this you will
see by comparing plates thirteen and eighteen.

** Acain, in the mean for each season, the greatest
amount of rain, at Toomavara, is invariably from S.W.,
whereas, at Monks Eleigh, in Winter it is from W., in
Spring from N., in Summer E., and in Autumn S&S.
Again, when the year is divided into two periods, from
Autumnal to Spring, and from Spring to Autumnal Equinox,
the greatest rain, for each period, is at Toomavara from
the S. W., and at Monks Eleigh from W. During the
entire year, the greatest amount at Toomavara is from

the S. W., but at Monks Eleigh from W.; and, though

456

the gross total of rain at Toomavara is nearly double that
at Monks Eleigh for the year, still the easterly rains at
the latter place are almost equal in amount, and, during
the Summer and Autumn, much more considerable. If, on
an examination of the mean results of many years, the same
directions of rain are found to be nearly the same in amount,
it will render the subject very interesting to meteorologists.

“ T have added also a plate of the years 1838 and
1839, for Toomavara alone; the mode in which the curves
are described is stated in the Proceedings for 1838, No. 10,
p. 146.

‘On some future occasion, we hope to be able to lay be-
fore the Academy the results of many years.”

A Comparative View of the Results of Rain-Guages observed
at Toomavara, County of Tipperary, by Rev. Thomas
Knox, and at Monks Eleigh in Suffolk, by Rev. meen
B. Knox.

12 Months. S. |S. W.| W. |N. W.) N. |N.E.| E. |S. E. || Total.
Decener f 2: ‘469| 1°034| -631] -188| -081| -028| 050) -133|| 2-614
M. E.| -421] 333] -431| -150| -040| -— | -015| -070|| 1-460

Nantan qe ‘155 | +926 |1-080| -096| -061} -050| -010| -010|| 2-388
M.E.| -147| -246| -705| -099) -078| -075| -033| -070|| 1-453:

hae i ‘383 | 1:333 |1-073| -386| -124| -212| -296| -202|| 4-009
Y (M.E| -157| -326] -636| -080| -059/ -080| -194] -213 || 1-745
Neon ie ‘509 | 1-088 |1-188| -340| -218| -136| :312| -388|| 4179
** \M.E.| -251] +345] -128] -229| -099| -020| -040| -110|| 1-222
ee tt 152] -458| -571| -162| -105| -341| -300| -176|| 2-265
pri's** (M.E.| 058| -218] -528| -102| -206| -060| -178| -002/| 1°352
-- jz 110} -461| -205| -070| -172| -032| -045| -312|| 1-407:
Yrr*+ (M.E} 008} — | -003| -031| -593| -352| -043| -— |) 1-030
fees ie *316| 1:371| -255| -055| -036| -499| -200\ -130]) 2-862
"*'* (M.E +176] -200| -290| -517] -636| -172| -645/ -039|| 2-675
ae {2 ‘317 | 1:281| -733] -483| -832| -840| -837| -245|| 5-568
Yer++\M.E.| -207| +113] -282| -224] -140| -051| -719| -383 |) 2-119
eae {z -236| 1:188| -460| -087| -200| -062| -160| -169 |) 2-562
‘*{M.E 044] +176] -246| -207] -186| 520] -100| -0i5 || 1.494

waite T. | +712] 2-428 |1-061| -115| -335| -047| -075| -515 || 5-288
EF em. {Mf B, 442| 431] +662] -593| -291| -213| -228| -287|| 3-147
October, 1: | 306] °848| -724) -399| -905| -810) -187| -201 || 4-380
croper+ \M.E.| -201| 106] -071| -085| 110} -308| -155| -150|| 1-186
.§ T. | 584] +280] -169| -259| -046| -021| -629 |1:042|| 3-030
Novem... {i 7562] °262| -389| -075| -338| -176| -742| -369|| 2-913
ae ie £249 |12-696 [8-150 |2-640 [3-115 /3-078 |3°101 (3°523 | 40 552
*** 1M. E.|2°674 | 2°756 [4.371 |2-392 |2°776 |2-027 |3-092 [1-708 | 21-796

Mean Results, &c. &c. S. |S.W.| W. |N.W.| N. |N.E.| E. | S.E.
: tT. | -336|1-098| -928| -223| -o89| -097| -119| -115

Mean of Winter... { Of -242| -302| -591| -110| -059| -052| -081| -118
i T. | °257| 669] -655| 191] 105| +170] -219/ -292

Do. Spring... +++. x.) -106| -188| -220| -117| -299| +144] -087| -037
T. | +290/1-280| -483} -208| -356| -467| -399| -181

+s Sonia M. E.| +142] 163} -273| -316| -321} -248| -488| -146
T. | -534/1-185 | -651| -258} -429|] -293] -297| -586

Do. Autumn ..... ) MB] -402| -266 | -374| -251] -246| -232| -375| -269

Summer Solstice,

Total from Winter to ( T. 1°720 |5°858 |4°618 |1°245 | -776 |L-278 |1:180 {1-238
Dec. 1838, June 1839

M. E.j1:036 |1-370 |2°142 | -659 {1085 | +740 |1°100| -475

to Winter Solstice,
stunejte, to Dec. 1839 M. E.}2°157 |1°376 |1°906 |1°621 |1°962 |1:409 |2-050 |1°520

Total. fror from sae (t ol 2761 \6°628 |3°315 |1°365 |2°337 |1-940 |2°195 |2:973

Total from Autumnal E la. 2 : ; s : 5
to Spring Equinox, Ae 2°649 |6°611 |5°068 |1-291] *982| :594/1°741 |1-318

Sept. ee March ) vr &./1-489 1-796 nite 810 {1-628 | -602 11-555 | -831

Total from Spring to T. {1°816 |7-058 |3-768 1-118 1-745 |1°875 |1-660 |1-273
Autumnal Equinox,
March to Sept. 1839. ¢ M. E.| :940 1.178 |2°032 |1-488 1-870 1:362 |1°913}| +726

William Pike, Esq. presented to the Academy an Irish
Quern, and some other ancient remains, found at Roughan
Island.

On removing the dam from the millrace, leading from
Roughan lake, near Dungannon, when the water subsided,
an island appeared nearly in the middle of the lake, which,
on examination, appeared to have been artificially formed
of timber and peat. The quern presented was found on
the surface; and numerous fragments of ancient pottery,
and bones, and a few bronze spear heads, were discovered at

the depth of a few inches.

Mr. Patterson exhibited to the Meeting a massive Gold
Ring, (of the form supposed to be the ancient ring-money,)
recently found near Belfast.

The President continued his account of his ‘‘Second Se-
ries of Researches respecting Vibration.”

458

DONATIONS.

Journal of the Royal Asiatic Society. No. XI. Pre-
sented by the Society.

Comptes Rendus Hebdomadaires des Seances de T Aca-
demie des Sciences. Premier Semestre, 1840, Nos. 13—19,
and Index. Presented by the Institute.

A Quern, Fragments of Pottery, and Animal Remains,
Sound on Roughan Island. Presented by Wm. Pike, Esq.

A Letter to the President of the Royal Irish Academy,
in reply to certain Charges made against George Petrie, Esq.
Presented by the Author.

A Manuscript Copy of Keating's History of Ireland, by
Andrew M‘Curtin, dated at Ibrickan, County of Clare, A.D.
1703. Presented by Richard Carmichael, Esq.

A bronze Axe. Presented by the same.

June 22.
SIR Wm. R. HAMILTON, LL.D., President, in the Chair.

The Rev. Dr. Todd continued his account of the contents
of the Book of Lismore.

The tracts next in order in this volume are legends
of ecclesiastical history,—as the legend of the venerable
Bede; of St. Petronilla, the daughter of St. Peter; of the
discovery of the Sybilline Oracle, in a stone coffin at
Rome; of St. Gregory the Great; the heresy of the Em-
press Justina. Then follow tracts on the origin of some
of the minor ceremonies of the mass; an account of the
successors of Charlemagne; the controversy of Archbishop
Lanfranc with the Romans, about Transubstantiation ; a bat-
tle between the priests of Rome and the devil; extracts
from the voyage of Marco Polo, translated into Irish ;
a very ancient tract on the wars of the celebrated Cal-
laghan Cashel, King of Munster, with the Danes, in the
tenth century; a romantic tale, entitled, The Adventures
of Teige, the son of Cian, the son of Oilliol Olum, King of

459

Munster; an account of the battle of Crionna, between Cor-
mac Mac Art and the Ultonians; the adventures of Laogh-
aire, son of a King of Connaught, with the fairies; the
manner in which Connor Mac Nessa, son of a Druid, ob-
tained the crown of Munster; a very curious historical
tale, entitled, The Seige of Druim Damhghaire, now Knock-
long, in the County of Limerick. This tale is of great im-
portance, from its undoubted antiquity, and the topogra-
phical descriptions which it contains of the country about
Fermoy, in the County of Cork.

The last tract in the MS. is one of very great in-
terest: it is in the form of a dialogue between St. Patrick
and the two survivors of Fiana Eireann,—Caoilte Mac Ro-
nain and Oisin, son of Finn Mac Cumhail. It describes
the situation of several hills, mountains, rivers, caverns,
rills, &c., in Ireland, with the derivation of their names.
It is much to be regretted, that this very curious tract
is imperfect, especially as no other copy of it is known
to exist. But for these defects we should probably have
found in this tract notices of almost every monument of note
in ancient Ireland: and, even in its present mutilated state,
it cannot but be regarded as preserving the most ancient tra-
ditions to which we can now have access,—traditions which
were committed to writing at a period when the ancient cus-
toms of the people were unbroken and undisturbed.

Rev. H. Lloyd, V.P., gave an account of a series of ob-
servations of the Magnetic Declination, made by Professor
Bache of Philadelphia and himself, in the hope of deter-
mining thereby differences of longitude.

It is well known that the magnetic declination, at a given
place, is subject to frequent and irregular variations, and
that corresponding changes occur, at the same instant of
time, at very distant places. The first recognition of this
remarkable phenomenon seems to have been made by Arago,
while comparing the observations of declination made by

460

himself, at Paris, in the year 1818, with the contempora-
neous observations of M. Kupffer, at Casan. Not long af-
ter, the subject underwent a fuller investigation in the hands
of Humboldt; and, in the year 1827, an extensive system of
simultaneous observations was organized by that illustrious
philosopher for the purpose of elucidating it. At length,
in 1834, it was taken up by Gauss, and received a much
greater development. Gauss discovered that the irregular
changes of the declination were of continual occurrence;
and that the synchronism, which had been previously ob-
served only in the larger changes, extended to the minutest
movements. In order to investigate the law of these syn-
chronous changes, and the locality and other circumstances
of the acting forces, Gauss arranged the extensive plan of
simultaneous observations at short intervals, which has been
already four years in operation, and in which almost every
country in Europe has been represented by some one or
more observers. 7

Having taken part in this combined system in the year
1837, Prof. Lloyd was led to inquire, in the first place, whe-
ther this irregular fluctuation of the declination might not be
still more rapid than appeared from the observations hither-
to made ; and, secondly, whether these shorter oscillations (if
they existed) corresponded in distant places, and could
therefore be employed to determine differences of longitude.

To investigate the first of these questions, a series of
observations was made in the month of September, 1837, at
very short intervals. The instrument employed was Gauss’s
magnetometer ; and the magnet being ina state of continued
vibration, observations were taken at each succeeding maxi-
mum elongation, and therefore at the interval of a single
oscillation,—which, in the case of the bar employed, was
27°.38. ‘The mean of each successive pair of readings was
then taken, to eliminate the mechanical oscillation, and the
results projected in curves in the usual manner. On an

\

461

examination of these curves it appeared, as had been antici-
pated, that the maxima and minima of the irregular movements
usually succeeded each other with very great rapidity, theit
interval being, on the average, about 40 seconds, and their
magnitude varying in these observations from 10” to 60”.

The observations were resumed on the 23rd of October,
and continued to the 26th, two series of an hour’s duration
being made each day, in the hope of detecting some law go-
verning the movements. No such law however could be traced,
nor did there appear to be any connexion between the curves
representing the march of the changes, at different hours of
the same day, or at the same hour on successive days.

The observed variations in these observations being small,
it was suggested by an experienced friend, to whom Prof.
Lloyd showed the results, that they were not true magnetic
changes, but merely the errors of observation incidental to
vibratory movement. In order to test this supposition, an
unmagnetic bar (the brass detorsion bar of Gauss’s appa-
ratus) was substituted for the magnet, to which it cor-
responded in dimension ; and being provided with a mirror,
was suspended by two parallel threads, and made to vibrate.
The time of vibration was adjusted, by varying the interval
of the threads, so as to differ little from that of the magnet.
The successive elongations were then observed, as in the
case of the magnet, and the means of each pair taken. The.
variations in these means (which could arise from errors of
observation or mechanical changes only) bore no com-
parison whatever in magnitude to the corresponding varia-
tions of position of the magnetic bar, thus showing that the
latter were truly the results ofthe operation of magnetic
forces.

The rapidity with which these changes thus appeared to
follow each other, held out the hope that they might be em-
ployed in determining differences of longitude; and it only
remained to ascertain, for that purpose, whether variations.so

462

inconsiderable in magnitude corresponded at great distances:
If such should prove to be the fact, it would be only neces-
sary to project on a large scale the results of the observations
made about the same absolute time at the two stations, and
to compare the times of the corresponding maxima and
minima. In the observations already referred to, the maxima
and minima succeeded each other (as has been said) at inter-
vals of about forty seconds, and the epoch of their occurrence
was probably known to six or seven seconds. By shorten-
ing still further the interval of observation, it is manifest
that this error may be much diminished. ‘The corresponding
error of the difference of longitude resulting from a single
comparison (supposing the probable error of epoch to be the
same at the two places,) will be greater in the ratio of 2
to 1; but this error, owing to the multitude of the maxima
and minima compared, must necessarily be greatly reduced
in the final mean.

In order to put this question to the test on the largest
scale, it was agreed between Mr. Bache and Mr. Lloyd, to
make a series of corresponding observations in Philadelphia
and in Dublin. Some difficulties occurred in concerting a
plan, and Prof. Bache underwent, in one instance, the labour
of an extensive series of observations, without any counter-
part in Dublin. At length, however, it was agreed to ob-
serve during the week commencing the 11th of November,
1839; the observations being taken during two hours on
each day—namely, from 12 to 1 p.m., and from 8 to 9 p. Mt,
Greenwich mean time.

Prof. Bache’s account of his observations is contained in
the following extract of a letter which accompanied them,
dated November 29, 1839.

“The place of observation is a room in one of the
out buildings for the dwellings of the Professors of the
Girard College. As the materials used in the construc-
tion of the house must produce considerable local attrac-

463

tion, no absolute measures have been attempted. All
moveable magnetic substances were removed from the vici-
nity of the needle. A window near the needle was carefully
closed by a shutter of wood, and by two curtains fastened
to the window frame, and with an interval between them.
There is no fire in the room; and a double door is between
the observing room and an adjoining one where there is a
fire.

** The instrument is one of Gauss’s declination magne-
tometers, made by Meyerstein of Gottingen. The arrange-
ment of it agrees exactly with that described in the Resultate,
which has been followed as nearly as possible. ‘The reading
telescope is supported upon a small wooden shelf fastened
to one of the side walls of the room; the scale is attached
to a wooden frame before the shelf. One of the smallest
divisions of the scale, which is divided by estimation in the
observations to tenths, is 25-975 nearly in value. The
zero of the scale did not vary sensibly in position during the
observations.

‘* The observations were made every eight seconds,.an
assistant striking two seconds before the time of each obser-
vation. The ticks of the half-seconds chronometer being
distinctly audible, the observation was made at the fourth
beat after the signal given by the assistant, and thus the
time was independent of the minute accuracy of the signal.
Checks were adopted to prevent or detect large errors in
giving the signal. The interval of eight seconds is very
nearly one-third of the time of oscillation of the magnet bar.

“‘ The time was observed by a chronometer beating half
seconds. This was compared before and after each set of
magnetic observations with one, and after the morning of the
14th with two chronometers. One of these was carried from
the Girard College‘to the city after each set of observations ;
but the others remained during the night at the Girard
College, and were removed to the city after the morning

464

series, to compare them with the stationary chronometer
belonging to the High School Observatory, the rate of which
was ascertained by observations of transit of the sun and
stars on the 6th, 9th, 11th, 13th, and 16th of November.
Girard College is about 1770 feet west, and 8050 north of
the High School by the city map.”

The Dublin observations were made in the Magnetical
Observatory. The instrument employed is of the form
described some time since to the Academy.* It is a mag-
netic collimator with a graduated scale of glass, each division
of which corresponds to 43/22 of are. The visual angle
under which each division is seen is so considerable, that the
divisions can readily be subdivided into tenths by estimation.
The time of vibration of the magnet is 17°78. The appa-
ratus containing the magnet, as well as the reading telescope,
are supported on stone pillars resting on solid masonry, and

insulated from the floor.

The observations having been undertaken by Prof. Lloyd
without assistance, it was found impracticable to observe at in-
tervals shorter than the time of vibration of the magnet bar,
of which each successive elongation was accordingly noted.
The time shown by the chronometer was usually noted every
tenth or twelfth vibration; and thus the time of the interven-
ing observations could be interpolated with much exactness.
The error of the chronometer was obtained on the nights of
the 11th, 14th, and 19th of November, by transit observa-
tions with the four-foot transit of the Observatory.

Of these observations, those made on Wednesday,
Noy. 13, (8—9) p.m. Greenwich mean time, were the most
favourable for the purpose contemplated. The changes,
though small, (from 5” to 50”,) were marked and rapid, the
intervals of the successive maxima and minima averaging
thirty-six seconds. The epoch of their occurrence seems to
be determinable to between four and five seconds.

* See Proceedings, No. 18, p. 330, e¢ seq.

465

When the two sets of observations were reduced and laid
down in curves, it was found that they presented no simila-
rity; in other words, that there was no correspondence whate-
ver between the smaller changes of the declination at Dublin
and at Philadelphia. 'The determination of differences of
longitude, by means of the magnet, is, therefore, impracti-
cable at such distances; but the attempt has revealed the
important fact, that the irregular changes of declination,
which have exhibited so marked a correspondence at the
most distant stations at which simultaneous observations
have been heretofore made, do not correspond on the Ame-
rican and European Continents. Prof. Lloyd observed that
much light would, erelong, be thrown upon this curious sub-
ject, by a comparison of the observations made at the Mag-
netical Observatory of Toronto, in Upper Canada, with
those of Europe.

A Paper ‘on the Cooling Power of Gases,” by Thomas
Andrews, M.D.,M.R.I.A., was read by Dr. Apjohn.

Leslie observed, long ago, that a heated body cools
more rapidly in hydrogen gas than in atmospheric air; but
Dalton and Davy were the first who attempted to estimate
the cooling powers of the gases, by observing the times
which a thermometer, heated to the same point, took to
cool through the same number of degrees in different gases.
So difficult of execution, however, is this method, that their
results differ, in every respect, most widely from each
other: thus, for example, Davy found that a thermometer
cooled twice as fast in olefiant gas as in nitrous oxide, while
Dalton found the rate of cooling in both these gases to be
the same. 4

The subject appeared to be deserving of further investi-
gation, and the author has endeavoured to pursue it by a
novel method, which may, perhaps, be susceptible of other
applications in inquiries connected with the science of heat.

466

When a fine metallic wire is placed in the circuit of a voltaic
circle, it is well known that it will become heated, and the
temperature which it finally acquires (provided the length
of the wire remain the same, and the action of the battery
continue constant) will depend upon the cooling power of
the medium in which the wire is placed. If the current be
of sufficient intensity to heat the wire to redness in air, the '
variations in its appearance, when placed in other gases,
will exhibit, at a glance, their relative cooling powers.
But, since the conducting power of wires for electricity di-
minishes as their temperature rises, a measure of the effect
may be obtained by ascertaining the changes produced in
the intensity of the current, which will increase or diminish,
according to the greater or less cooling power of the me-
dium in which the wire is placed.

The battery, employed in the following experiments,
consisted of four large cells, on Daniell’s construction,
charged with his standard solutions; and of a small cell,
composed of an exterior cylinder of amalgamated zinc, and
an interior plate of platina, the latter being separated from
the former by a cylindrical membrane, and both immersed in
dilute sulphuric acid. The hydrogen gas, disengaged from
the platina plate, was collected in a graduated tube, and its
volume taken as a measure of the intensity of the current.
A platina wire, about 2°5 inches long, and ;1, in dia-
meter, was stretched in the middle of a wide glass tube, by
means of copper pincers, which were connected by thick
wires of the same metal with the poles of the battery. The
glass tube was so adjusted as to be easily traversed by a cur-
rent of gas, which afterwards escaped from beneath a sur-
face of mercury, and the connecting wires being passed
through collars of caoutchouc, the whole apparatus was ren-
dered perfectly air-tight.

In making the observations, a current of the-gas, care-
fully dried, was passed in great excess through the appara-

467

tus, in order to sweep away, as completely as possible, the
atmospheric air; the current was then arrested, and, the
connexions with the battery being established, the appear-
ance presented by the heated wire was noted, and the inten-"
sity of the current transmitted through it ascertained by co 1
lecting the hydrogen evolved in the small cell during the
space of two minutes. The gas was next displaced by a
current of dry air, and the same experiment repeated.
During these experiments the battery was always in a very
constant state of action. The results are contained in the
following table, in which the second column gives the quan-
tity of hydrogen extricated at each experiment with the
wire in air ; the third with the wire in the gas; and the fourth
column expresses the ratios of these numbers—those in the
second being taken as unit :—

Name af Gas. Sine ta ain) ee wh poe!" | havi ee
Muriatic acid, §. . . 65:9 63:1 0:958
Sulphuric acid, . . . 69°2 66°9 0°967
OREN, hyse ">, in tly he 67'3 67° 0-995
Carbonic oxide, . . . 68:1 68°3 1-003
Wyanocen,. . ... . 66°3 67° 1:010
Carbonicacid, . . . 66°6 67°5 1:013
Deutoxide of nitrogen, 66:2 67°3 1-016
Protoxide of nitrogen, . 68'3 69°6 1-019
OVC oe eo 68°3 69°6 1:019
Olefiantgas, . . .. 68:2 76:2 1-171
iiignoniays 54 Qe % 67°4 75'3 1-118
FAVOR ey 06 oy cnpe) etn 67:0 92°6 1°382

As, however, the law, which connects the intensity of a
voltaic current traversing a wire with the temperature to
which it raises the wire, is unknown, these numbers do not
furnish us with the means of determining the exact variations
of temperature, sustained by the wire which was employed
in these experiments. But, as a term of comparison, it

2R

468

may be mentioned that, when the wire was immersed in
distilled water which prevented its temperature from sensi-
bly rising, the intensity of the current was almost exactly
twice as great as when the wire was allowed to become
heated, in atmospheric air at the ordinary pressure.

The appearances presented by the platina wire corres-
ponded with the foregoing results. In atmospheric air, it
exhibited a bright red heat; in the muriatic and sulphurous
acid gases, the redness was distinctly a shade brighter; in
cyanogen, carbonic oxide, and hydrogen, there was no sen-
sible difference ; in carbonic acid, oxygen, and the deutox-
ide of nitrogen, the wire, so far as the eye could judge, ap-
peared rather duller than in air; while, in olefiant gas and
ammonia, it was only raised to a very obscure red heat, and
in hydrogen, no redness whatever was visible, even in com-
plete darkness. This method may, it is obvious, be ex-
tended to vapours; and, from some trials made with them,
it appeared that the cooling powers of the vapours of alco-
hol and ether are considerably greater than the cooling
power of air, and that of steam very slightly greater. On
the other hand, the cooling power of all gases diminishes as
they become rarefied ; so much so, that the platina wire used
in the preceding experiments reached in vacuum nearly its
point of fusion, while, at the same time, the intensity of the
current considerably diminished.

The gases may be conveniently arranged into the following
groups, in reference to their cooling powers; and it will be
found, on inspecting the table, that those arranged in each
group differ little in this property from each other :—

Group I. Gases whose cooling power is less than that
of atmospheric air :—sulphurous acid, muriatic acid.

Group II. Gases whose cooling power is nearly the
same :—nitrogen, carbonic oxide, cyanogen, carbonic acid,
deutoxide of nitrogen, protoxide of nitrogen, oxygen, va-
pour of water.

469

Group III. Gases whose cooling power is greater :—
olefiant gas, ammonia, vapours of alcohol and ether.
Group IV. Hydrogen.

Dr. Apjohn next drew the attention of the Academy to
a metallic ore recently found at the Kilbricken Lead
Mine, County of Clare, which he had received through a
friend from Mr. M. Taylor, the gentleman who conducts the
mining operations in that district. It occurs in amorphous
masses of a bluish grey colour; has a metallic lustre, and
something between a compact earthy and close foliated struc-
ture. Specific gravity =6:407 ; hardness intermediate be-
tween that of galena and sulphuret of antimony. Subjected
to the action of the blowpipe sulphur is burned off; white
oxide of antimony is deposited upon the charcoal; and a
metallic globule is produced, brittle at first, but which be-
comes malleable lead after having been submitted for some
time to the action of the oxidating flame. In muriatic acid
the ore dissolves, though slowly, with the evolution of sul-
phuretted hydrogen; and the solution, when poured into a
large quantity of boiling water, gives a white precipitate
(oxichloride of antimony.) When this precipitate has sub-
sided, the solution is found to contain nothing but chloride
of lead, with traces of antimony and iron. From these ex-
periments the mineral was concluded to be a combination of
sulphur, lead, and antimony; and to determine the proportions
in which they were associated, the following analytic process
was adopted.

44-52 grains of the ore, previously reduced to a fine
powder, were introduced into a ball, blown upon a tube of
Bohemian glass; and through this a current of dry chlorine
was made to pass, the arrangement of the apparatus being
such, that by a rectangular bend in the portion of the tube
beyond the ball, the chlorine was made to bubble through a

470

dilute solution of tartaric acid. This acid was placed in a
tall flint-glass bottle with narrow neck, the mouth of which
was closed (but not air tight) by a cork which was perforated
so to receive the vertical arm of the bent tube. Upon con-
tact of the chlorine and ore considerable heat was developed.
When, the current of gas being still maintained, this began
to subside, a lighted spirit lamp with circular wick was
placed beneath the ball, and its flame gradually augmented
so as to expel the chlorides of sulphur and antimony, and
finally to fuse the chloride of lead; and a smaller spirit
flame was at the same time made to play on the tube beyond
the ball, so as to cause the volatile chlorides to pass into the
tartaric acid, or at least into the vertical portion of the tube
whose further extremity was immersed in the acid solution.
The tube was now nicked with a file, and broken across
at its point of flexure; and the portion not connected
with the ball was subjected to a stream of distilled water,
so as to wash any chlorides which it might include into the
bottle containing the tartaric acid. This portion of the
tube was now heated to redness, so as to render it perfectly
dry, and then weighed along with the remaining fragment on
which the ball was blown, and which contained the chloride
of lead. The weight of this chloride was thus obtained ;
being obviously equal to the weight last obtained, diminished
by the weight of the ball and tube. It was thus found to
amount to 40°96 grains, equivalent to 30°52 of metallic lead.
The remaining constituents of the ore were now in the tar-
taric acid, the sulphur being partly in the free state, but
chiefly in the form of sulphuric acid. The free sulphur was
first separated, and found to weigh 0°1 grain. To the acid
solution chloride of barium was added, which threw down
the sulphuric acid in the form of sulphate ofbarytes. This,
when well washed, dried, and ignited, weighed 51°87 grains,
equivalent to 7°15 sulphur ; hence 7°15 + 0°10 = 7-25 is the
total amount of the sulphur.

471

Sulphuric acid was next added, to precipitate any ex-
cess of barytes; and, this being separated by filtration, sul-
phuretted hydrogen was passed through the solution, which
threw down the antimony as orange tersulphuret. The
vessel being placed upon the sand bath for about an hour,
so as to expel any excess of sulphuretted hydrogen, the
precipitate was collected on a filter, and exposed for a con-
siderable time to a temperature not exceeding 212°. Being
thus rendered perfectly dry, it was found to weigh 8°85
grains, equivalent to 6°37 metallic antimony.

The solution from which the antimony was separated
was supersaturated with ammonia, and sulphuretted hydro-
gen was again passed through it, which threw down the
iron; upon this precipitate nitro-muriatic acid was digested,
and the unacidified sulphur being separated by a filter, the
acid solution was supersaturated with ammonia, which threw
down peroxide of iron, weighing, when ignited, 0°244 grains,
equivalent to 0°17 grains ofiron. The following, therefore,
are the results of the analysis :

SE okie he ens a AR aD
ead ee er re ae thee Waa Ural
itor ee Ce ere Ord
Antimony ere ee Ore
Moss s - epercplunt Remi mein Le

100 parts therefore of the ore consist of

(1) ayrtagriet@
Sulphur. . . 16°36 . EOt6- . TOOTS -O"lod
Mead. 2. OS'St Ve 0'OG4
PRR Oss Sain 19a Ne Gora fo CORK 18989
Antimony. . 14°39 . O-111 . O-111 . 1000

100

The numbers in column (2) are the quotients obtained by
dividing the corresponding ones in column (1) by the atomic

472

weights of the substances they represent. The numbers in
column (3) are the same as those in (2), with the exception
that the quotients for the lead and iron are added together.
In (4) we have other numbers in the same ratio as the
preceding. A mere inspection of the latter is sufficient
to show that the empirical formula of the mineral is
So Pbg Sb,; and such being the case, there can be no doubt
that the rational formula is
6 (S, Pb) + 83, Sb,

or that it consists of six atoms of sulphuret of lead associated
with one atom of tersulphuret of antimony, a little of the
former metai being replaced by an equivalent quantity of
iron.

The above are the particulars of the analysis which ap-
peared on the whole to have been most successfully per-
formed ; the analysis, however, was repeated three times,
and the results in each instance conducted to the formula
just given. In the first trials, in consequence of strongly
heating the ball traversed by the chlorine from the very
commencement of the experiment, some of the chloride of lead
was volatilized, and Dr. Apjohn was led to conclude the con-
stitution of the mineral to be materially different from what it
afterwards proved to be. The ball should not be heated
until the spontaneous action of the chlorine on the ore has
ceased.

Kilbrickenite, as Dr. Apjohn proposed to call this mineral,
is obviously what Berzelius denominates a sulphur salt, i. e.,
a combination of an electro-negative with an electro-positive
sulphuret. But there are several other ores known to mine-
ralogists composed of the same proximate constituents, or
including sulphuret of lead in association with the sulphuret
of antimony. The subjoined list comprehends those which
have been analysed and described.

473

Zinkenite. . . . . S, Pb+S, Sb.

Plagionite . . . 4(S, Pb)+3 (Ss, Sb).
Jamesonite . . . [5(S, Pb)+S83, Pb.]+4 (S3, Sb)?
Featherore oflead 2 (S, Pb)+8s, Sb.

Boulangerite . . 3(S, Pb)+ S83, Sb.

A mere inspection of the formule is sufficient to show
that each mineral in this list is distinct in composition from
that whose analysis has been given above. There is, however,
an ore possessing a constitution perfectly analogous to the Irish
mineral—namely, the sprédglaserz of Mohs and Werner,
or what Dr. Thomson calls brittle silver glance. The formula
of this mineral Rose has shown to be 6(S, Ag)+S;, Sb;
so that it differs from Kélbrickenite merely in containing
silver instead of lead.

The following note—‘‘ On a principle for producing an
everburning Flame,” by George J. Knox, Esq., was read by
the Secretary :

** A beliefin the discovery of an everburning lamp appears
to have been prevalent in all ages; and tradition informs us
that lamps have been found in tombs, where they have con-
tinued burning for upwards of 1000 years, of which mention
has been made in the works of St. Austin, Plutarch, Pliny,
Ludovicus Vives, Baptista Porta, and Licetus. The
Rosecrucians,* who laid claim to the knowledge of every-
thing mysterious, pretended to have rediscovered the secret
of their construction, which was supposed to have been
buried in the tomb of their founder. Dr. Plott,f in a
treatise which he has written upon this subject, alludes to a
lamp mentioned by St. Austin in his book de Civitate Dei,
which was hung up in the temple of Venus; and to another
found in the tomb of Pallas the Arcadian, who was slain by
Turnus in the Trojan war, which continued to burn after

* Spectator, vol. v. No. 379.
+ Lowthorp’s Abridgment of Phil. Trans. vol. iii. (636).

474

its removal from the tomb and exposure to the air—proving
that these lamps were not supplied from any bituminous
source, or volcanic fire. He considers the requisites for
an everburning lamp to be,—a perpetual wick, which
might be made of gold wire, or asbestus; and a perpetual
supply of fuel, which he imagines the bituminous springs
of Pitchford, in Shropshire, or the inflammable gases is-
suing from fissures in coal mines, would afford. That such
could supply fuel for a flame, so long as the bituminous
spring existed, or the gas continued to exhale from the
mines, is evident; but itno more deserves the appellation of
an everburning lamp, than does a fire arising from any
voleanic source. The desideratum for such a lamp is, that
it should contain, within itself, a renovating principle, such
as, probably, does the luminous atmosphere encompassing

the body of the sun, supposed by Sir William Herschel
to be electrical.

**That electricity was the principle upon which such a
lamp could be constructed having occurred to me some
years ago, I reflected upon the different means by which a
constant light could be produced from this source, and
concluded that, if by an arrangement of metals a thermo-
electric current could be produced of sufficient intensity
to decompose water, the heat produced by the burning of
the two gases arising from the decomposition, would be suf-
ficient, when applied to the alternate metallic junctions, to
continue the electrical current of the thermo-electric pile;
while the gases, which in burning become aqueous vapour,
might be condensed by passing through a long tube, through
which being conveyed to the closed vessel in which the
water had been originally placed, they would again under-
go decomposition, recombination, and condensation. Sucha
thermo-electric arrangement has been discovered by Prof.
Botto of Turin, who has obtained decomposition of water
from a series composed of a great number of wires of

475

platinum and iron. To prevent the apparatus from acquiring
in time the same temperature, the alternate junctions of the
metals, to which the heat is not applied, might be con-
nected with the pedestal upon which the lamp is placed;
and the pedestal be either allowed to rest in a cold situa-
tion, or else be connected by wires with some extensive
cooling surface.”

The President gave an account of some investigations re-
specting Fluctuating Functions, from which the following
are extracts :—

‘* Let Pp, denote any real function 2, continuous or discon-
tinuous, but such that its first and second integrals,

\, dx Py, and ie dv) Pa

are always comprised between given finite limits. Let also

the equation
x 2
(S de) Pa py
0

in which p is some given constant, have infinitely many real
roots, both positive and negative, which are not themselves
comprised between any finite limits, but are such that the
interval between any one and the next greater root is never
greater than some given finite interval. Then,
; b Sf

gaa ) E dx M4 dyPy F,== 0, (A)
if @ and J are any finite values of x, between which the
function Fz is finite.

‘‘ Again, the same things being supposed, let the arbitrary
- function F; vary gradually between the same values of x;
and let Pp, be finite and vary gradually when z is infinitely
small; then

Fy=o7 ¥ dt ‘. dz Pity Fay (y25)> (B)

25s

476

in which
2D 1
a= da y : dt Prr-

‘For the case y=a, we must change @, in (B), to

1
Sie dx \ dt Pixs
oO o

and for the case y= 5, we must change it to

. :
w ee NOTA WOT Pie

“ For values of y >6, or <a, the second member of the
formula (B) vanishes.

“Tf F,, although finite, were to receive any sudden change
for some particular value of y between a and 8, so as to pass
suddenly from the value F" to the value F, we should then
have, for this value of y, ‘

20 b
) ) av\ dX Pix ty Fr=@F +o" Fr.
oO a

By changing P, to cos w, we obtain from (B) the celebrated
theorem of Fourier. Indeed, that great mathematician ap-
pears to have possessed a clear conception of the principles
of fluctuating functions, although he is not known to have
deduced from them consequences so general as the above.

** Again, another celebrated theorem is comprised i in the
following :—

b 2 Cb
Fy=@— P, (\ dx Fob 3 ) CURIE Le Fr) Jeeal®)
a T/L a
in which, the function @ is defined by the conditions

eet
aan dx r= J dx Pr;

nL — x

y is > a, <6; and no real root of the equation
. dz Pz, = 0,
tv)

except the root 0, is included between the negative number
a—y and the positive number b—y, nor are those numbers

ATT

themselves supposed to be roots of that equation, When
these conditions are not satisfied, the theorem (C) takes
other forms, which, with other analogous results, may be
deduced from the same principles.”

Mr. Petrie exhibited an ancient Irish consecrated bell,
recently obtained by the Dean of St. Patrick’s, and which
had been for many generations in the possession of a family
named Hanan, or O’Hanan, in the county of Armagh. This
bell is of the usual quadrangular form, in use amongst the
Irish from the introduction of Christianity into the country
till the close of the eleventh century, but has an approxi-
mation to the round form which became general after the
latter period. The age of this bell can be determined with
perfect accuracy, from the following inscription in the ancient
Irish character which is carved upon it.

+ OR ap Cumapeach me Cililla,
or “ Pray for Cumuscach the son of Ailill.”

The death of this Cumuscach, who was Economist of the
Cathedral of Armagh, is recorded in the Annals of the Four
Masters at the year 904. His mother, who was named
Gormlaith, was a daughter of Murdach King of Ulster.

The Academy then adjourned to Monday the 9th of
November.

DONATIONS.

Archaeologia. Vol. XXVIII. Presented by the Society of
Antiquaries of London. |

Transactions of the Zoological Society of London. Vor
II., Parts 1, 3, 4, and Proceedings, Nos. 4, 5, 6,7. Pre-
sented by the Society.

Cambridge Astronomical Observations for the Year 1838.
By the Rev. James Challis, M.A. Presented by the Author.

478

Annual Report of the Maitland Club for 1840. Present-
ed by John Smith, Esq.

A Letter to Sir W. R. Hamilton, by Sir Wm. Betham.
Presented by the author.

An Essay onthe Study of the Celtic Languages, by A. B.
Chapin, M.A. Presented by the Author.

Two Gold Fibulz, found at Castlebar, and purchased by
Subscription. Presented by the Subscribers. —

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