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A

JOURNAL

- OF

NATURAL PHILOSOPHY,
CHEMISTRY,

AND

THE AR TY be:

VOL. XXI.

Jllustrated with Engravings.

BY WILLIAM NICHOLSON.

LONDON: -
PRIINTED BY W. STRATFORD, CROWN COURT, TEMPLE BAR ; FOR

W. NICHOLSON,
CHARLOTTE STREET, BLOOMSBURY ;
AND SOLD BY

J. STRATFORD, No. 112, Horsorn Hirt.

1808.

PREFACE,

Tue Authors of Original Papers and Communications in the
present Volume are, John Gough, Esq.; Dr. Thomas Stewart
Trail; Opsimath; A. Dilethante; Mr. William Cooke; Mr.
William Skrimshire, Jun.; Mr. Robert Bancks; P. Barlow, Esq. ;7
A Correspondent; Dr. Beddoess J. B.; John Bostock, M. D.;
W. Saint, Esq,; Mr. A. Combes; J. A. De Luc, Esq.; William
Walker, Esq.; W. Moore, Esq.; James Woodhouse; Mr. B..
Cook; Mr. J. Acton; 8S. Vince.

__OFf Foreign Works, M. Vauquelin; John Michael Haussmann ;
M. Gueniveau ; M. Berthier; M. V. Auarie; M. Frederic Mohs;
M. Tonnelier; M. P. Turpin; M. Theodore de Saussure; A.
Avogadro; J. C. Delamatherie; Lewis Cordier; J. P. D’ Aubuisson;
Professor Proust; R. J. Hauy. .

And of British Memoirs abridged or extracted, ‘Thomas
Andrew Knight, Esq.; Lord Ribblesdale; Thomas Thomson,
M.D. F.R.S.; Mr. William Hardy; Mr. Henry Ward; Mr.
Martin Furniss; Abraham Parsons, Esq.; Mrs. Hooker; Mr.
William Murdoch; Everard Home, Fsq. F. R. 8.3; Mr. Gilbert
Gilpin; Mr. Christopher Wilson ; J. Witley Boswell, Esq.; Major
Spencer Cochrane; William Hyde Wollaston, M. D. Sec. R. S.;
Mr. George Smart; Mr. Joseph Davis; Mr. S. Mendham; Mr,
Edward Massey; Edmund Turrell; Robert Buchanan; Mr. Joseph
: oe: Mr. William Shipley; Humphry Davy, Esg. Sec. R. 5S.

oe. A. .

The Engravings consist of !. Dr. Trails Mercurial exhausting —
Machine; 2. Problem by J. Gough, Esq.; 3. Mr. Hardy’s Cor-
-rection of Vibration in Time Keepers; 4. Mr. Henry Ward’s
Compensation Pendulum; 5. Mr. Furniss’s Air-tight Door Hinge;
6. Mr. C. Gilpin’s Machine for raising Coals; 7. Mr. C. Wilson’s
secure-Sailing or Life Boat; 8. Mr. J. Boswell’s improved Capstan ;
9. Mr Mendham’s Escapement ; 10. Mr. Davis’s Chimney Brush ;
11, Mr. Davis’s Pannels for Security; 12. M. Tonnelier on the
Meionite; 13. Mr. Massey’s Patent Log ; 14. Mr. Massey’s Sound-
ing Machine ; 15. Diagrams illustrating the Problem respecting the
Radius of Curvature; 16. Instruments for the Construction of im-
proved Chemical Muffles; 17. Mr. Collier’s Ship’s Stove, 18. Mr.
Shipley’s Floating Licht; 19. Mr. Acton’s Improvement in the
Still; 20. Crystals of Carbonate of Lime.
TABLE

TABLE’ O:F CONTENTS
TO THIS TWENTY-FIRST VOLUME.

SEPTEMBER, 1808.

Engravings of the following Objects: 1. Dr. Traill’s Mercurial Exhausting Ma-
chine: 2. Problem by J. Gough, Esq.: 3. Mr. Hardy’s Correction of Vibra-
tion in Timekeepers: 4. Mr. Henry Ward’s Compensation Pendulum:

. 5.-Mr. Furniss’s Air-tight Door Hinge.

I. A Mathematical Problem. by John Gough, Esq. : h

Il. On the Incontrovertibility of Bark into Alburnum. By Thomas Andrew
Knight, Esq. F. R.S. In a Letter to Sir Joseph Banks, K. B. P.R.S. 5

I[I. Account of a Mine of Zinc Ore, and its Application as a Paint. By the
Right Hon. Lord Ribblesdale, of Gisburne Park, Yorkshire = 12

IV. On’Oxalic Acid. By Thomas Thomson, M. D.F.R.S. Ed. Communicated
by Charles Hatehett, Esq. F. RS. - - = . i4

V. Analysis of some Iron Ores in Burgundy and Franche-Comte, to which is
_ added, an Examination of the Pig-Iron, Bar-lron, and Scorie, produced
‘from them. By Mr. Vauquelin. - - 4 92

VI. On the Maddering of Cotton and Linen Thread, and Dyeing them Adria-
nopie Red and other fixed Colours; and on Spontaneous Inflammations: by
John Michael Haussmann - - 2 44

WIJ. Account of Inventions for equalizing the long and short Arcs of Vibration
in Timekeepers ; by Mr. William Hardy, No. 29, Coldbath Square 51
VIN. Description of a Compensation Pendulum for a Clock, or Timepiece,
with Experiments. By Mr. Henry Ward, of Blandford, in Dorsetshire 53

YX. Account of a new air-tight Hinge for a folding Screen, or for a Door; by
Mr, Martin Furniss, No. 128, Strand 4 = 61

X. Description of an exhausting Machine on the Principle of the Torricellian

Vacuum: by Dr. Thomas Stewart ‘Traill - - : 63
XI. Doubts respecting some of the received Doctrines of Chance. Ina Letter
from a Correspondent - - - ; “ 66
MII. Letter from a Correspondent on the late Discovery of Metals in the fixed
Alkalis - - - - i 68
XIII. On the Decomposition of the Alkalis. In a Letter from Mr. William
Cook - - > - - : 69
XIV. On the Quantity of Feculain different Varieties of the Potatoe. By |
Mr. William Skrimshire, Jun. - - - i val
Scientific News = - - ae < a : 77
Account of the Situation of the Instruments employed by Mr. Robert Bancks,
for the Meteorological Journal - - - - 79
Meteorological Journal - ° : x z 80

OCTOBER

GROIN EEN T'S. Vv

OCTOBER, 1808.

En payings of the i hancinae Objects: 1. Mr. Gilpin’s Machine for raising
oals, Ore, &c.: 2. Mr. C. Wilson’s secure Sailing, or Life Boat: 3. Mr.
J. W. Boswell’s Improved Capstan.

I. Method of making a Composition for Painting in Imitation of the ancient
Grecian Manner, with ea ae Mrs. eee *) Rottingdean, near
‘Brighton ~ = - 8¥

IJ. On Oxalic head! By Thomas Thomson, M. D. F.R:S. ar Communicated
by Charles Hatchett, Esq. F.R.S. - 86

Il. An Account of the Application of the Gas from Coal to economical Pur-
poses. By Mr. William res pe aa at a ee) the at as Hon. 2H
Joseph Banks, Bart. K.B. P. R. 5.

LY, Farther Experiments on the Spleen. By Everard Home, Esq. F.R.S. 103

Vz. Account of anew Machine fer raising Coals, or other Articles, from Mines,
by Mr. Gilbert Gilpin, of Old Park Iron Works, near Shifnal 111

‘Vi. Remarks on Se: Covel: Essay on Polygoual Ne by P. Barlow,
Esq. = 118

VII. Some farther Remarks on the Doctrines of Chance, in a Letter from a
Correspondent - - - 5 J

VIII. Description of a secure Sailing Boat, or Life Boat. By Mr. Christopher
Wilson, Richard-street, Commercial Road - - 124

TX. Description of a Capstan, that works without requiring the Messenger or

-Cable coiled round it et be ever surged. ae pe BPN Esq., of
Clifford’s Inn - 133

X. Letter from Dr. Beddoes on certain Points of History, relative to the Com-

ponent Parts of the Alkalis, with Observations cc to the Coinposition of
the Bodies termed Simple - - - 139

XI. Analysis of some nine hs acs a By Mr. Gueniveau, Mine
Engineer - - - 142

XIE. Analysis of a Cabenste of a from ee BY Mr. Berthier, Mine
Engineer - - 150

XI. Chemical Examination of the Stalk of Indian Corn, Tea Mays Lm., to
ascertain whether the Saccharine Matter it contains be capable of Crystal-

lization; by Mr. V. ape, awa Valence, Department of the
Dréme - - - 58:

’ XIV. On the Culture of Spring Wheat, and the Use of Tincture of Opium in
the Diseases of Cattle: by Major Spencer Cochrane, of Muirfield House,

near Haddin North Britain - - - 156
Scientific News —— - - - - 159
Meteorological Journal = = - - - Sia ce,

NOVEMBER,

ti CONTENTS
NOVEMBER, 1808.

Engravings of the following Objects: 1. Mr. Mendham’s Escapement : 2. Mr.
Davis’s Chimney Brush: 3. Mr. Davis’s Pannels for Security: 4. Mr. Tonne-
lier’s Remarks on the _Meionite.

I. Observations on the Exhausting Machine of Dr. Thomas Stewart Traill. By
Mr. Robert Bancks, Mathematical Instrument Maker, in the Strand 161
II. On Superacid and Subacid Salts. By William Hyde Wollaston, M. D.
Sec. R.S. = - . ‘ - * 164
YI. Account of Experiments on Sweeping Chimneys. By Mr. George Smart
170
IV. Description of a Machine for cleansing Chimneys, without the Use of
climbing Boys. By Mr, Joseph Davis, No. 14, Crescent, Kingsland Road
173
YY. Account of an Invention to secure the Pannels of Doors and Window Shut-
ters from being cut out by House-breakers. By Mr. Joseph Davis, No. 14,
Crescent, Kingsland Road - - “ 4 177
VI. Description of anew Watch Escapement. By Mr. S.: Mendham, Counter
Street, Borough « - - = fe 178
VII. On the Fecula of Potatoes, and some other British Vegetables. By Mr.
William Skrimshire, Jun. - - 2 2 182.
VIII. Remarks on Meionite, with some Observations on a Paper by Mr. Fre=
deric Mohs, in which this Substance is considered as a Variety of Feldspar.
By Mr. Tonnelier, Keeper of the Cabinet of Mineralogy to the Council of
Mines - ne 2 ; - - 191
IX. Method of finding the Quantity of Refraction from the Distance and Al-
titude of two known Stars; and of solving by Construction a Problem in Sphe-
rical Trigonometry. In a Letter from a Correspondent “ 201
X. Early Account of an Albiness. Ina Letter from John Bostock, M.D. 203

XI. Remarks.on the Doctrines of Chance, in Answer to Opsimath, in a Letter
| from W. Saint, Esq. . - ; - - 204
MIL. Further Remarks on the Doctrines of Chance. By Opsimath 210

XII. Memoir on the Organ by which the fertilizing Fluid is capable of being
_introduced into the Ovula of Vegetables. By P. Turpin. Read at the Nas
tional Institute, Dec. 4, 1808 - . " = 214

_ XIV. Essay on the Composition of Alcohol and of Sulphuric Ether. By The-
odote de Saussure. Read to the Physical and Mathematical Class of the In-

’ stitute, Aprilthe 6th, 1807 - - 2 a 299
XV. Letter on the Subject of the new Metals. -By Mr. A. Combes 231
XVI. Remarks on Ignition by Compressed Air. In a Letter from J. A. De Luc,
Esq. - - 2 - - > at 4
XVI. On the Disadvantage of Jewelled Holes in Clockwork. Ina Letter from

Mr. W. Walker, to Mr. J. Barraud - * “ 236
Scientific News - > ~ - > 237

Meteorological Journal - ° - ie 240

DECEMBER,

CONTENTS wii
DECEMBER, 1808.

Engravings of the following Objects: 1. Mr. Massey’s Patent Log: 2. Mr.
Massey's Sounding Machine: 3. Diagrams illustrating the Problem respectin
the Radius of Curvature: 4. Implements for the Construction of ingiaovl
Chemical Muffles.

J. Answer to Mr. Barlow’s Remarks on the Essay on. Polygonal Numbers. By
J. Gough, Esq. - = - at - 241,

II. Description and Use of a Sea Log, and Sounding Machine, invented by
Mr. Edward Massey, of Hanley, in Staffordshire - - 245

HII. Observations on the Problem respecting the Radius of Curvature. Ina
Letter from W. Moore, Esq, = ° « > — 256

IV. Essay on the Composition of Alcohol and of Sulphuric Ether. By The-
odore de Saussure ° - : - - 259

Vv. Description of an improved Mode of constructing Muffles for Chemical
Purposes. By Mr. Edmund Turrell, No. 40, Rawstorne-street, Goswell-
street, Road - = - 2 2 273

YI. Consideration on the State in which a Stratum of non-conducting Matter
must be, when interposed between Two Surfaces endued with opposite Elec-
tricities.. By A. Avogadro, Corresponding Member of the Academy of Sci-
ences at Turin - - < - a hicee lou

VIL. Account of an Experiment in wl:ich Potash calcined with Charcoal took
Fire on the Addition of Water, and Ammoniacal Gas was produced, In a
Letter from James Woodhouse, University of Philadelphia, &c. 290

VIII. On the Advantages of employing Coal Gas for lighting small Manufac-
‘tories, and other Purposes. In a Letter from Mr. B. Cook - 291

TX. Extract from a Letter to J. C. Delametherie, on Volcanic Substances. By
Lewis Cordier, Mine Engineer - - - 298

X. Letter to J. C, Delametherie on some Granatoid Lavas. By J. P. D’Aubu-
isson - - - - - - 299

Al. An Examination, of a Stone of the Calcareous Species, called ‘* Thunder
Pick.” By Mr. J, Acton, of Ipswich, communicated by the Author 300

XII. Remarks on a Reyiew of Professor Vince’s Essay on Gravitation. Ina

Letter from the Author - - - > 305
XIII. An Essay on the Sugar of Grapes. By Professor Proust - 306
Scientific News Bs ie Lay es - 316
Meteorological Table « : ° wk - $20

SUPPLEMENT

Viid CONTENTS.
SUPPLEMENT. TO VOL. XXI.

4 ey
Engravings of the following Objects: 1. Mr. Colliers Ship’s Stove: 2. Mr. Ship-
ley’s Floating Light: 3. Mr. Acton’s Improvement in the Still: 4. Crystals of
Carbonate of Lime. °

I. Essay on the Composition of Alcohol and of Sulphuric Ether. By Theodore
de Saussure, . - - 5 - 321

Il. Description of an improved Ship’s Stove. By Mr. Joseph Collier, No. 11,
€rown Street, Soho - - - - - BaT

YI. Account of a Floating Licht calculated to save the Lives of Persons, whe
have the Misfortune to fali overboard in the Night from any Ship. Invented
by Mr. Wm. Shipley, Founder of (he Society for the Encouragement of Arts,
Manufactures, and Commerce - . © 338

IV. An Essay on the Sugar of Grapes. By Professor Proust = 341

V. Account of a simple Improvement in the common Still. In a Letter from
Mr. J. Acton : - ahs . - 358

VI. Description of a new Variety of Carbonate of Lime. By R.J. Hauy 359

VII. Second Letter on the Subject of the New Metals. By Mr. A. Combes
363

VIII. Electro-Chemical Researches, on the Decomposition of the Earths; with
Observations on the Metals obtained from the Alkaline Earths, and on the
Amalgam procured from Ammonia. By Humphry Davy, Esq. Sec. R- §.
M.R.I. A. . - - - - 366

Scientific News, . : Pe eee 4 “389

A
JOURNAL
OF
NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

SEPTEMBER, 1808.

ARTICLE I.

A Mathematical Problem: by Joun Gouan, Esq.

To Mr. NICHOLSON.
SIR, Middleshaw, August 5, 19808.

"Tue insertion of the following problem, with the inves-
tigation of it, in your valuable Journal, will oblige

Yours, ‘&e.
JOHN GOUGH.

Problem. Toa given arc of a Late a, let it be required The problem
‘to add another z, making the sum of the two arcs equal to Proposed.
the tangent of the latter, t, viz. a+zat.

(A) We may show in the following manner, that the Containsn
problem contains nothing absurd in it; but that, on the ‘is absurd.
contrary, there is a value of z to each value of a, which
would fulfil the conditions of the ial were we hut able
to rectify the circle.

(B) Let ABC, PI. I, fig. 6, be the given arc, consist- This assertion
ing of n quadrants, n being any positive number, whole or Poppaeiet
fractional ; to this add the quadrant C P D, in which take

Vout. XXI. No. 91—SxEpr. 1808. B the

9 MATHEMATICAL PROBLEM.

the variable arc C E; and through E, from the centre O,
draw OF, meeting the tangent C T, n F; put CO=r,
O F=s, arc C E=z, corresponding tangent C F=y; then
by the nature of the circle, as s*:r*:: 9:4; but s” is
greater than r*, therefore 7 is greater than 7, consequently
y increases faster than x: moreover, when y=0, a+a2o=d |
+ 0=a, in which case bp. is infinitely greater than y, but
y increases faster than x, and exceeds it infinitely, when
x= the quadrant CPD; consequently, by prime and
ultimate ratios, there is a-point P betwixt C and D, which
cuts off an arc C P, orz, the tangent of which, C T, or
t= the arc AC Pore aeeSe %
The geometri- (C) When AC P=CT, the sector AOP= heh ble
Pin er he COT: ; from each take the common sector C OP, and AX:
sector A OC = the space C P T; hence the problem,
treated geometrically, assumes this form ; to find a point T
in the tangent C F, produced if necessary, from which if
TO be drawn to the centre, it shall give the space C P' T
= the given sector AOC, for this construction will evi-
dently make the tangent C T = the arc ACP.
When a= 0, (D) Ifthe are ABC=0, the sector AO C =9; there-
ree ET fore the space C P T=0, by (C); hence the are C E P=0,
; i.e. when ao, 218 evanescent; consequently, the problem
is impossible, unless ¢ be a finite magnitude.
mnotrestricted (E) It appears from (B) and (D), that z isa real, not an
tooddnum- . . ot . : * =
ae imaginary arc, provided a be a finite magnitude, which may
as be expressed by nQ, Q being a quadrant, and-n a positive
number, either whole or fractional. This conclusion how-
ever is rejected by a celebrated mathematician, who inti-
mates, that n is atv ays an odd number; the passage con=
taininig-his opinion is here quoted.

“ Invenire omnes arcus, qui tangentibus suis sint
wequales. ita in slat |
© Solutio. Primus arcus, hac proprietate prieditns, est
infinite parvus. “J'um in secundo quadrante, quia hie tan-
gentes sunt negative, datur nullus isttusmodi areus;” in
tertio vero quadrante dabitur unus 270° aliquanto minor;
porro dabtintur ejusmodi arcus in quinto, septimo, &¢.”

The reason assigned for » being an odd number in this
quotation 1s deriv red from the su Sig that all the tan-

ee

MATHEMATICAL PROBLEM. — 5

gents, are negative in even quadrants. To examine this
reason on its own principles, let us, “suppose the given are @
-to begin at B in the figure, not at A, as in article (B) + ;
then a= arc BC = a quadrant, and n=1, this makes
C ED the second or an even quadrant: through B and C
draw the tangents BR, TCR, and the angle TRB is
manifestly right; that is, € T is perpendicular to BR, but
B R is a positive tangent, because BC is an odd quadrant,
and T C has been shown to be perpendicular to B R, which
invalidates the reason why n should be odd, because the
relations of perpendicular lines are not the relations of -+
and —, or positive and negative quantities.

(F) Certain mutual relations of a and z may be investi- Mutual rela-
gated in the following manner. Suppose these ares to i ee
so as to preserve the equation a+z=1, and w we have +z

ae

hence d=t—z, but ¢ hs = (+77) x = therefore @ =
vz : CL Ses 5
Po Now when z is less than 7 t* is less than 7”, and @
is less than z; but @ and z begin together by (D), or the
present ticle : therefore, when 7 is a small are, it is gr eater
than a, and z—a is the greatest, when the angle COP=
45°; on the contrary, 3 wel 2z—Q itis finite, and a maxi-
mum, and a is also a maximum, but infinite; hence we
have the following equations, a= (n—1) Xz, toa+-z=nz,
where n is any number, whole or fractional, greater than
unity. |

(G) These things being premised, we may fade by ape 2 found by ap

proximation, @

proximation to any given value of a, thus: put the given are Pon
being given.

at+Q, or ACD= g> r=i,are P D=», its tangent or co-
tangent of z==q; then by the hae ives but by tri-
17v’ 6209

315 ' aate

gonometry txqar ==, ands gq vf a

1382v"" 218440"3 929569 v**

155025 | 6081075 | 638512875. 758 Now Pulse 159
ais. 35, &e. = b,c, d, e, &c. respectively; and we have
tq=gv—v +g bvi—be++gcvi—er® +g dv3—d v8 4
gev’—ev', &c. = 1; and by reverting the series, as in
Emerson’s Algebra, page 171, Problem LXIJ) we get v=
BQ

7

09 |

Example to
the last para-
graph.

» in the last are
ticle is too
great.

a2 found when
z Ri

Example to
the last. para-
graph.

MATHEMATICAL PROBLEM.

14—15 g7 b+-3 24 b’—2%e

a
§

» &e.; but vis the com-

1 Q——e*h 5—Ag*b
dh SRS

‘8 Ag; s* &§
4256 g” sn b—6 g* aM b

i

plement of z; therefore 2e+ -Q—v =1°570796—v nearly.

(H) For example, let a=9%X 3 ; then g= bi xQ=
— ob
15°707963 whence += -063662; 7, =-000266; == "=
f° gi gg ‘
(5 es Zz
"000089. Stopping here we get v = + * 4 = 3 =
°063839; but arc C P= Q-——v = 1'5060957: dividing this
by °017453 the length of a degree to the radius unity, we
get 86° 20’ wht for the angle subtended by the ave C P,

or Zz.

5
(K) Since t= g—v=15° 644121; and goog e422 Xe.

—-063992; we have ¢Xg=1'001098, &c. ; but ¢q=1 uni-
versally, which shows, that g—v exceeds the true value of

1
t, or Ores 62386, &c.; therefore v is a little too jou

vik makes z too little: but Hi is to be scheme, that
the true place of - has been nearly found 1 im an even qua-
drant. Sr
(L) It appears from (F), that we Bac put ¢=n2; more-
over, we have (by trigohometry) gists hence gz2=

i —; put z=Q—2, Q being a quadzant or 1 570796 ; also,
A q=v+bv? +cv'+dv’, &c., as in (G), and we have
Qv—v? +Q bv bert Qevi—ev® me. = 3 : arid by re-

d ; 1 1 2—Q*
ving the wi, we et ot ght Oy

5—4Q*5
TE aia ee

aes vis known, z is given ieee

&e., water n is always greater than unity; but

~ (M) Put 2— 100, ‘then aan 000636, be 5 = "000028 ;

stopping devbi we get v= 000664, sailt s=1 ‘Re or 89°
37 48”. i
(N) When

INCONVERTIBILITY OF BARK INTO ALBURNUM. 5 |

(N) When a is but small, the series given in (G) con-
verges but slowly, in which case the following approxi-
mation may be used. Since a+z=1t, z=t—a, but z=

3 15 t7 t? he _ 13 Os t i t? ae 7
t— te 9 &c. § ne 3 5 7 9 5
=a; put 3xa=p, and we have, by Emerson’s Algebra,

cs Ah) ad
Vinee Me
(P) For example, let a=-009, then p=-027, and p? =

&e.

page 76, t—p + £

-3, and substituting the successive powers of °3, or p*, we
get t='3054157, and z=t—a—="2964157.

(Q) When n, in (L), consists of a unit and a small frac-
tion, we may also approximate to the value of t, by help of
the two values of z, viz. é —, and ee ee &e.3 fan

n 3 5 7
which we get Latch fe ea a , &e. SS ah call the
Serene Ae n

4 io
small fraction,

1 é
»w; and we have by reversion, ?7=3 x

w-+ 5:4 xX w* + 7°86857139 X w* + 10°33714521 XK wt +
12°8037915 x w®, &e.

II.

On the Inconvertibilit, y of Bark into Alburnum. By Tuo-
mas AnpRew Kniaut, Esq. F.R.S. Ina Letter to Sir
Josern Banks, K. B. P.R.S.*

My dear Sir,

In a letter which I had the honour to address to you iM patter that,

the end of last yeart, I endeavoured to prove, that the poenpeeee the
matter, which composes the bark of trees, previously exists ae henalls
in the cells both of their bark and alburnum in a fluid of both bark &

state; and that this fluid, even when extravasated, is capa- sannghmate

* Phil. Trans. for 1808, P.I, p. 103.
+ Phil. Trans. 1807; or Journal, vol. XIX, p, 241.

ble —

6 INCONVERTIBILITY OF BARK INTO ALBURNUM.

ble of changing into a pulpous and cellular, and ultimately
a vascular substance; the direction taken by the vessels be-
ing apparently dependent on the course, which the descend-
ing fluid sap is made to take*. The object of the present.
Always ree Memoir is to prove, that the bark thus formed always re-
mains bark. ‘hains in the state of bark, and that no part of it is ever
transmuted into alburnum, as many very eminent naturalists
have believed.
Experiments \ Having procured, by grafting, several trees of a variety
ea le of the apple and crab tree, the woods of which were distin-
guishable from each other by their colour, I took off, early
Theirbark mu- in the spring, portions of bark of equal length, from
meee moscu- branches of equal size, and I transposed these pieces of
. bark, enclosing a part of the stem of the apple tree with a
covering of the bark of the crab tree, which extended quite
round it, and applying the bark of the apple tree to the
stem of the crab tree in the same manner. Bandages were
then applied to keep the transposed bark and the alburnum
in contact with each other; and the air was excluded by a
plaster composed of bees wax and turpentine, and with i
covering of tempered clay, :
Interior sur- The interior surface of the bark of the crab tree ‘pre-
faces different. sented numerous sinuosities, which corresponded with simi-
‘lar inequalities on the surface of the alburnum, occasioned
by the former existence of many lateral branches. The in-
terior surface of the bark of the apple tree, as well as the
_external surface of the alburnum, was, on the contrary,
Union took _ perfectly smooth and even, A yital union soon took place
pa: between the transposed pieces of bark, and the alburnum
‘and bark of the trees to which they were applied; and in
Alayer of al- the autumn it appeared evident, that a layer of alburnum

Pxtravasated * T had observed this circumstancé in many successive seasons; but I
“anitmal fidids’ was not -by any ‘nieans prepared to belive, that such an aMefizeniént
Mg vaseue contd take place in the coagulum afforded by an extravasated fluid; and

, Jam indebted to Mr, Carisle. fur having pointed out to me many cir-
_ cumstances in the motion and powers of the blood of animals, which in-
“duced me ‘to give credit to the accuracy of my observations; and to that
gentleman and to Mr, Home I have also subsequently to acknowledge

maany obligations, A

3 had

INCONVERTIBILITY OF BARK INTO, ALBURNUM.« 4

XN
had been, iu every instance, formed beneath the transposed burmum form-
pieces of bark, which were then taken off. _ ed beneath.

Examining the organization of the alburnum, which had Alburnum did
been generated beneath the transposed pieces of bark of the Pot adapt its

surface to that
erab tree, and which had formed a perfect union with. the of the foreign
alburnum of the apple tree, I could not discover any traces bark.
of the sinuosities I had noticed ; nor was the uneven: sur-
face of the alburnum of the crab tree more changed. by the
smooth transposed bark of the apple tree. The newly ge-
nerated alburnum, beneath the transposed bark, appeared
periectly similar to that of other parts of the stock, and the
direction of the fibres and vessels did not in any degree.cor-
respond with those of the transposed bark *.

Repeating this experiment, I scraped off the external Surface of the
surface of the alburnum in several spaces, about three lines meg
in diameter, and in these spaces no union took place be-
tween the transposed bark and the alburnum of the stock,
nor was there any alburnum deposited in the abraded
spaces; but the newly generated cortical and alburnous
layers took a circular, and rather elliptical, course round
those spaces, and appeared to have been generated by a de-
scending fluid, which had divided into two currents when it
came into contact with the spaces from which the surface
chad been scraped off, and to have united again unmediately
beneath them.

In each of these experiments, a new cortical and Sid! New cortical &
nous layer was evidently generated ; and apparently by the aca mary
same means that similar substances were generated beneath
a plaster composed of bees wax and turpentine, in former
experiments; and the only obvious difference in the result
appears to be, that the trausposed and newly generated bark
formed a vital union with each other: and it is sufficiently

* Duhamel having taken off, and immediately replaced, similar pieces p.,hamel’s exe
of the Iwrk of young elms, subsequently’ found, that the alburhum, periment de-
which was generated beneath suc! pieces of bark, had not formed any fective.
union with the alburnum of the tree beneath it. But this great natu-
talist did not employ ligatures of sufficient power, to bring the bark
and alburnum into close contact, or the result would have been dif-

ferent.
-+ Phil. Trans. for 1807; or Journal, vol. XIK, p. 243.
evident,

Young shoots
of oak. No
transmutation
of bark into
alburnum,

JRCONVERTIBILITY OF BARK ENTO ALBURNUM.

evident, that if bark of any kind was converted into albur-
num, it must have been that newly generated. For it can
scarcely be supposed, that the bark of a crab tree was
transmuted into the alburnum of an apple tree, or that the
sinuosities of the bark of the crab tree could have been ob-
literated, had such transmutation taken place. There is
not, however, any thing in the preceding cases calculated
to prove, that the newly generated bark was not converted
into alburnum; and the elaborate experiments of Duhamel
sufficiently evince the difficulty of producing any decisive
evidence in this case; nevertheless I trust, that I shall be
able to adduce such facts as, in the aggregate, will be found
nearly conclusive.

Examining almost every day, during the spring and sum-
mer, the progressive formation of alburnum in the young
shoots of an oak coppice, which had been felled two years
preceding, I was wholly unable to discover any thing hke
the transmutation of bark into alburnum. The commence-
ment of the alburnous layers in the oak (quercus robur) is
distinguished by a circular row of very large tubes. These
tubes are of course generated in the spring; and during
their formation, I found the substance through which they
passed to be soft and apparently gelatinous, and much less
tenacious and consistent than the substance of the bark it-
self; and, therefore, if the matter which gave existence to
the alburnum previously composed the bark, it must have
been, during its change of character, nearly in a state of
solution. But it is the transmutation of one organized sub-
stance into the other, and not the identity only of the mat-
ter of both, for which the disciples: of Malpighi contend ;
aud if the fibres and vessels of the bark really became those
of the alburnum, a very great degree of similarity ought to
be found in the organization of those substances, No such

similarity, however, exists; and mot any thing at all corres-

ponding with the circular row of large tubes in the albur-
num of the oak is discoverable in the bark of that tree.
These tubes are also generated within the interior surface of |
the bark, which is well defined; and during their formation
the vessels of the bark are distinctly visible, as different or-

‘gang: and had the one been transmuted into the other, their

progressive

INCONVERTIBILITY OF BARK INTO ALBURNUM. g

progressive changes could not, I think, possibly have escaped

my observation. Nor does the organization of the bark in Barks of wych
other instances in any degree indicate the character of the st Bia a
wood, that is generated beneath it: the bark of the wych tially,

elm (ulmus montana) is extremely rough and fibrous; and

it is often taken from branches of six or eight years old, to

beused instead of cords; that of the ash (fraxinus excel-

sior) on the contrary, when taken from branches of the

same age, breaks almost as readily in any one direction as

in another, andscarcely presents a fibrous texture; yet the

alburnum of these trees is not very dissimilar, and the one but not the al-
is often substituted for the other in the construction of agri- Mele ay Pe
cultural instruments.

Mirbel has endeavoured to account for the dissimilar or- Mirbel’s thes
ganization of the bark, and of the wood into which he a
conceives it to be converted, by supposing, that the cellu-
lar substance of the bark is always springing from the al-
burnum, while the tree is growing; and that it carries with
it part of the tubular substance (tissu tubulaire) of the li-
ber, or interior bark. These parts of the interior bark, which
are thus removed from contact with the alburnum, he con-
ceives to constitute the external bark or cortex, while the
interior part of the liber progressively changes into albur-
num.

But if this theory (which I believe I have accurately Objections to
stated, though I am not quite certain, that I fully compre- this theory.
hend its author*) were well founded, the texture of the
alburnum must surely be much more intricate and inter-
woven than it is, and its tubes would lie less accurately pa-
raliel with each other than they do: and were the fibrous
substance of the bark progressively changing into alburnum,
the bark must of necessity be firmly attached to the albur-
num during the spring and summer by the continuity, and
indeed identity of the vessels and fibres of both these sub-
stances. This, however, is not in any degree the case, and
the bark is in those seasons very easily separated from the
alburnum ; to which it appears to be attached by a substance
that is apparently rather gelatinous than fibrous or vascular:

* Chap. HI, Article 5, Traité @ Anatomie et de Physiologie Véodtale.

and

10 INCONVERTIBILITY OF BARK INTO ALBURNUM.

and the obvious fact, that the adhesion of the cortical ves-
sels and fibres to each other is much more strong than the
adhesion of the bark to the alburnum, affords another cir-
Objection to ‘cumstance almost as inconsistent with the theory of Malpi-
Malpighi. — g@hi, as-with that of Mirbel.
Duhamels ex. Many of the experiments of Duhamel are, however, ap-
periment of parently favourable to the theory of Malpighi, respecting
srl al- she conversion of bark into alburnum; and Mirbel has cited
two, which he appears to think conclusive*. In the first of
these Duhamel shows, that pieces of silver wire, inserted
mm the bark of trees, were subsequently found in their al-
burmnum. But Duhamel himself has shown, with his usual
acuteness and candour, that the evidence afforded by this
experiment is extremely defective; and he declares himself
to be uncertain, that the pieces of wire did not, at their first
msertion, pass between the bark and the alburnum ; in
which case they would necessarily have been covered by
every successive layer of alburnum, without any transmuta-
tion of ‘bark into that substancef.
Hisexperiment In the second experiment cited by Mirbel, Duhamel has
ofa peach bud shown, that when a’bud of the peach tree, with a piece of
aa hiram bark attached to it, is inserted in a plum stock, a layer of
plum stock. wood perfectly similar to that of the peach tree will be
found, in the succeeding winter, beneath the inserted bark.
The statement of Duhamel is perfectly correct: but the
experiment does not by any means prove the conversion of
bark into wood; for if it be difficult to conceive (as he re-
marks) that an inserted piece of bark can deposit a layer of
alburnum, it is at least as difficult to conceive, how the
same piece of bark can be converted into a layer of albur-
num of more than twice its own thickness (and the thick-
ness of the alburnum deposited frequently exceeds that of
the bark in this proportion), without any perceptible dimi-
nution of its own proper substance. The probable opera-
tion of the inserted bud, which is a well organezed plant,
at the period when it becomes capable of being transposed

‘* Chap. HI, Article’5.
+ Physique des Arbres, Lib. 1V, Ch, Hl.

with

INCONVERTIBILITY OF BARK INTO ALBURNUM»

with success, appears also, in this case, to have been over-
looked ; for-I found, that when I destroyed the buds in the
succeeding winter, and left the bark which belonged to
them uninjured, this bark no longer possessed any power
to generate alburnum. It nevertheless continued to live,
though perfectly inactive, till it became covered: by the
successive alburnous layers of the stock; and it was found
many years afterwards enclosed in the wood. It was, how-
ever, still bark, though dry and lifeless, and did not. ap-
pear to have made any progress towards conversion into
wood,

In the course of very numerous experiments, which were
‘made to ascertain the manner in ‘which vessels are formed
in the reproduced bark*, many circumstances came ‘under
‘my observation, which I could adduce ia support of my
opinion, that bark is never transmuted into alburnum; but
T do not think it necessary to trouble you with an aécount
‘of them; for though much deference is certainly due to the
opittions of those naturalists, who have adopted the opposite
‘theory, and to the doubts of Duhamel, Lam not acquainted
with a single experiment, which warrants ‘the conclusions
‘they have drawn; and’ think, that, were bark really trans-
‘muted into alburnum, its progressive changes could only
-haveescaped the eyes of prejudiced ‘or inattentive observers.
“Lathe course of the ensuing 'spring, I hope to address to
you some observations respecting the manner in which the
alburnum is generated.

r ' Lam, my dear Sir,
Your most obliged obedient servant,

A BIS 416 - ‘PHOMAS AND. KNIGHT.
Elton, Dec. 29, 1807.

—“® Phil. Trans, for 1807; or Jourial, vol. XIX, p. 241,

be | Til,

6 |

No facts to
prove, that
bark is con-
verted into al-
burnum.

12 USE OF ZINC ORE AS A PAINT.

TT.

Account of a Mine of Zinc Ore, and its Application as..4
Paint. By the Right Hon. Lord Ripsiespauy, of Gis-
durne Park, Yorkshire *.

SIR,

Ore of zinc as Herewirn I send you a specimen of aiden paint,
awhite painte which, for the sake of humanity, I trust will be found a
complete substitute for that baneful article white lead.

I have used this paint for twelve years upon my house,
paling, doors, &c. [tis of a delicate stone tint, but be-
comes equal 4n colour by time to the best white lead, and
for durability, for never blistering, and for body and ner
sion infinitely superior to it.

If the specimen (which is the average of what may be
ordinarily obtained, although for particular purposes it may
be produced much finer), should meet with the approbation
of the Society of Arts, &c., I shall at any time, with the
greatest pleasure, at their request, render them all the in-
formation upon the subject in my power. I have painted
four or five years ago a vessel, which is now in his Majesty’s

Resists salt wa- service, with this paint, and nothing can exceed the resist-
we ance which this paint makes to all the effects of salt water
to decompose it.
I have the honour to be, with much respect,
Sir,
Your obedient humble servant,

RIBBLESDALE.

Additional Communication by Lord Ribblesdale, on his Ore of
Zine.

Mines. The mines are situate at Mallam Moors, in Craven,
Yorkshire, and in an extent of country of eleven or twelve

* Trans. of the Soc. of Arts for 1807, p. 35. Although this ore of
zine did not appear, upon trial by various persons, fully to answer the
purposes of white lead, as a basis for paint, yet it possessed sufficient
merit, to induce the Society to vote their silver medal to his Lordship.

thousand

/
USE OF ZINC ORE AS A PAINT, 13:

thousand acres of land belonging to his Lordship; where
the mineral is found, there were formerly copper mines.
This article is found in caverns, about eight fathoms from
the surface of the earth. The mineral lies in strata, along
the bottoms of these caverns, which strata are from three to
six feet thick, and the best coloured mineral, or whitest, lies
the lowest. On the upper part of the caverns are beautiful
stalactites of great hardness.
One of the caverns wherein it is found is one hundred
and four yards, another forty-four, and a third eighty -four
yards in length, and about fourteen yards wide.
His Lordship supposes this mineral has been sublimed Siveouditiag
by a volcano, as the stones surrounding it have been vitri- stones tigi 4

fied.

The mineral was first tried as a paint twelve years ago; Tried asa paint
it was previously sold, and continues to be sold to make !* Yeats +80-
brass at Birmingham and other places. He has sold up-
wards of two thousand tons, at from five to ten pounds per Before used for
ton, for making brass, when mixed with copper. _ maiie bias.

His Lordship stated, that it has answered well for house Its excellen-
painting externaily, and the whiteness improves by time; “°*
that it will in painting cover a much larger surface than
white lead paint, and he supposes it will do half as much
more work; that it forms a body on the wood so hard as to
resist the edge of an adze; and that it forms a strong ce-
ment Uebrast two boards painted with it.

\

‘That it will never peel off; that the oil paint on palings
withstands the effect of moisture; and that it will mix as a
basis with all other colours.
His Lordship added, that the price will not exceed that Cheap.
of white lead; on the contrary, he thinks, that, except in
the finest preparations, upon an average it will come consi-
derably low er,
Dear Sir,
PERMIT me again to assure the Society, that the body The ore very
of ‘my pa nt is equal to white lead, and that the ore itsel{ PU
is so pure, and is found in the mine so little mingled with

any

14 / ON OXALIC ACID.
any other substance, that I do not lose two pounds of the,
colour in a ton of the ore.
I remain, dear Sir,
Your very humble servant,

RIBBLESDALE.

i i
On Oxalic Acid. By Tuomas Tuomson, M. D. F.R.S.
Ed. Communicated by Cuarius Hartcuert, LEsq.,
FR. S.*

Ovxanic acid, from the united testimony of Ehrhart,
Oxalic acid Hermbstadt, and Westrumb, appears to have been disco-
discovered by vered by Scheele; but it is to Bergman that we are indebted
Scheele. for the first account of its properties. He published his dis-
sertation on it in 1776, and since that time very little has
been added to the facts contained in his valuable treatise.
Chemists have chiefly directed their attention to the forma-
tion of that acid, and much curious and important infor-
mation has resulted from the experiments of Hermbstadt,
Westrumb, Berthollet, Fourcroy, Vauquelin, &c. but the
properties of the acid itself have been rather neglected.
Pp Aaa My object in the following pages is not to give a complete
paid to its pro- history of the properties of oxalic acid, but merely to state
perties. the resultiof a set of experiments, undertaken with the view
‘of ascertaining different particulars respecting it, which t
conceived to be of importance.

I. Water of Crystallization.

Oxalic acid is usually obtamed in transparent prismatic

crystals more or less regular; these erystals contain a por-

El aston, tion of water, for when moderately heated they effloresce
and lose a part of their weight, which they afterwards reco-

ver when left exposed in a moist place. When cautiously

heated on a sand bath they fall to powder, and lose about a

third of their'weight. But as the acid js itself yolatile, it is

* Philos. Trans, for 1807, p. 63,
not

ON OXALIC ACID. 13

4
not probable that the whole of this loss is water. To ascer-

tain the quantity of water contained in these erystals I had

recourse to the following method.

1. Seventy grains of crystallized oxalic acid were dissolved The acid pre- ®
in 600 grains af water, constituting a solution which weighed eas se
-670 grains. lime,

Fifty grains of pure carbonate of lime, in the state of cal-

careous spar, were dissolved in muriatic acid; this solution
was evaporated to dryness, to get rid of the excess of acid,
and the residue redissolved in water.

Into this muriate of lime the solution of oxalic acid was As the muriatic
dropped by little and little as long as any precipitate fell, as he towit
and the oxalate of lime thus formed was separated by the portions in so-
filter. Pure oxalic acid is not capable of precipitating the lutte,
whole lime from solution of muriate of lime, the muniatic
acid evolved being always sufficient to retain the last por-
tious in solution.

It was necessary to get rid of this excess of acid ; the me- this saturated
thod which appeared the least exceptionable was to saturate >Y wig iigiise
the muriatic acid with ammonia ; accordingly when the ox-
alice acid ceased to occasion any farther precipitate, I cau-
tiously added pure ammonia, till the liquid ceased to pro-
duce any effect upon vegetable blues. A copious additional
precipitate of oxalate of lime was thus obtained. Oxalic
acid was now added again as long as it rendered the liquid
muddy. By thus alternately having recourse to the acid
solution, and to ammonia, and by adding both with great
caution to avoid any excess, [ sohbet in separating the
whole of the lime, without using any sensible excess of ox-
alie acid.

558 grains of the acid solution were employed, a quan-
tity which is equivalent to 58:3 grains of the crystallized
acid,

_ 9, The oxalate of lime, after being well washed and
drained, and exposed for a week to the open air, at a tem-
perature of about 60°, weighed 76 grains; but upon being
left on the sand bath for some hours in a temperature be-
tween 200° and 300’, its weight was reduced to 72 grains.
_3. These 72 grains of dry oxalate of lime were, put into
an open platinum crucible, and gradually heated to redness.

16 ON OXALIC ACID.

By these means they were reduced to 49°5 grains, which:
proved to be carbonate of lime. The crucible was now ex-
posed to a violent heat in a forge. Nothing remained but
a quantity of pure lime weighing 27 grains.

72 dry oxalate 4. From this experiment we learn, that 72 grains of dry

= aig 27 oxalate of lime contain 27 grains of lime. Of consequence,
the oxalic acid in this compound must be 45 grains. But
the weight of crystallized oxalic acid actually used was
58°3 grains, a quantity which exceeds the whole acid’ in
the oxalate by 13°3 grains. These 13°3 grains are the
amount of the water of crystallization, which either did
not unite with the salt, or was driven off by the subsequent

Crystals of ox- exposure to heat. Hence crystallized oxalic acid is com-
alic acid con-
tain ‘23 water.

posed of

Real acid. evve A5° ay i 77
Water....2++- 13°93 : equivalent to ; 93

ey ee,

58°3 100

So that the crystals of oxalic acid contain very nearly the
fourth part of their weight of water *.

If. Alkaline and Earthy Oxalates.

Oxalate of 1. The preceding experiment gives us likewise the com-
vee 4 position of oxalate of lime. This salt, when merely dried
37-5 base. in the open air, still retains a portion of water, which may

This propor- * Vauquelin in a late dissertation on cinchona, marked with that pro-

tion confirmed found skill which characteiizes all the productions of this illustrious

by an experi- chemist, has menuoned incidentally, that the crystals of oxalic acid

ie Vaile contain about half their weight of water. He dissolved 100 parts of
cinchonate of lime in water, and precipitated by means of oxalic acid ; 22
parts of crystallized oxalic acid were necessary ; and the oxalate of lime
formed weighed 27 grains. From this experiment he draws the conclu-
sion which I have stated (See Ann, de Chimie, lix, 164; or our Journal,
vol. XIX, p. 213). But this ingenious chemist does not seem to have
been aware of the real composition of oxalate of lime. 27 grains of
that salt are composed very nearly of 10 grains of lime and 17 grains of
acid, But the weight of the crystals used by Vauquelin was 22; the
difference, 5, is obviously the water of crystallization in 22 grains of
the crystals. But if 22 grains contain 5 of water, it is’ obvious, that 100
contain very nearly 23, So that his experiment in reality cvincides with
mine,

be

ON OXALIC ACID. 17

be driven off by artificial heat. It is necessary to know, Dried with dif.
that it-parts with this water with considerable dithculty, so meulty.

that a long exposure on the sand or steam bath is necessary,

to get it thoroughly dry. It afterwards imbibes a little wa-

ter, if it be left ina moist place. Well dried oxalate we

have seen is a compound of ;

Acid ‘45 or per cent, 62°5 acid.

Base 27 37°5 base.
2 100

Though the oxalate of lime dried spontaneously can Dried slowly at
ci ated rage pe a, als 60° contains
searcely be considered as always im the same state, yet 2S 0-53 water,
the difference in the portion of water which it retains is not
ereat, provided it be dried slowly in the temperature of 60°,
and in a dry place, it may be worth while to state its compo-

sition. It is as follows:

/

Acid 45 or percent 59:2 acid.

Base 27 35°5 base.
Water 4 5*3 water.
70 100:0

When rapidly dried, as by pressing it between the folds Dried rapidly
of filtering paper, it is apt to concrete into hard lumps, ee Page
which retain more moisture. In thisstate I have sometimes
‘seen it retain 10 per cent of water after it appeared dry.

Bergman states the composition of oxalate of lime as Bergman’s
follows: ‘ statement,

PCT ale ala Mate wis\ 6istie eibieye vite ete A8

Bae sis ajo ns tebes #8 sled = 46
Saher sume odisinitinisisia pices G

100*

His method was to dissolve a determinate quantity of cal- pis method.
careous spar in nitric acid, and then to precipitate the lime
by oxalic acid. 100 parts of calcareous spar thus dissolved,
require, according te him, 82 parts of crystallized acid to
) precipitate them. But there must have been some mistake

= Opusce. I, 262.
Vou. XXI.—Sepr. 1808. Cc in

18 ON OXALIC ACID.

in this experiment; for, according to my trials (provided
the nitric acid be carefully naturalized by ammonia as it is
evolved), no less than 117 grains of exalic acid would have
been required, and at least 145 grains of oxalate of lime
would have been obtained instead of the 119, which was the
Cause of his result of Bergman’s experiment. It is. obvious, that Berg-
mistake. man did not precipitate all the lime. He added oxalic acid
till it ceased to produce any effect ou the solution from the
great excess of nitric acid evolved; and then took it for
granted, that all the lime was separated. But had he added
ammonia, he would have got an additional quantity of oxa-
late of lime, and the precipitation would have recommenced
upon adding more oxalic acid. This explanation accounts
In a satisfadtory manner for the difference between Berg-
man’s statement of the composition of oxalate of lime, and
mine.
The preceding 2, "Though the preceding experiment was made with care,
neta venue yet as some of the most important of the following observa-
tions in some measure rest upon the analy sis of oxalate of
lime, 1 thought it worth while to verity that analysis in the
following manner, —

100 grains of crystallized oxalic acid were dissolved in
1000 grains of water, making a solution which weighed
1100 grains.

It is obvious, that every 100 grains of the above solution
contained 9°09 grains of crystals of oxalic acid, equivalent,
according to the preceeding analysis, to 7 grains of real
acid,

- 100 grains of this solution were gradually mixed with
lime water, till the liquid ceased to produce any change on
vegetable blues. The oxalate of lime thus formed, being
well dried, weighed 11'2 grains. Exposed to a violent heat
in a platinain crucible, als salt left 4°2 grains of pure
hi me. Hence it was composed of

7 acid, or per cent 62°5 acid

4°2 lime 37°5 base

11°2 ' 100°0
Thus we have obtained exaétly the same result as in the
former experiment, both as far as relates to the composition
of

ON OXALIC ACID. 19

of oxalate of lime, and likewise to the proportion of water
of crystallization in crystallized oxalic acid.

The lime water necessary to saturate the acid amounted Water dissolves
to 3186 grains, Hence, it contained only ,1,th of its ;¢ lime.
weight of lime.

'3. The oxalates of barytes and strontian are white, taste- Oxalates of ba-
less powders, which may be obtained by mixing oxalate of 'Ytesandstron-
ammonia with the muriates of these alkaline earths. Itis ” -
said, that these earths are capable of forming soluble su-
peroxalates with this acid; but I have not tried the experi-
ment. These oxalates, as well as oxalate of lime, are par-
tially soluble in the strong acids. \

4. Oxalate of magnesia is a soft white powder, bear- Oxalate of
ing a considerable resemblance to oxalate of lime, It Magnesia.
is tasteless, and not sensibly soluble in water; yet when
oxalate of ammonia is mixed with sulphate of magnesia,
no precipitate falls; but if the solution be heated and con-
centrated sufficiently, or if it be evaporated to dryness, and
redissolved in water, in both cases the oxalate of magnesia
separates in the state of an insoluble powder.

5. Oxalate of potash readily crystallizes in flat rhom- Oxalate of
boids, commonly terminated by dihedral summits. The la- Potash.
teral edges of the prism are usually bevilled. The taste of
this salt is cooling and bitter. At the temperature of 60°
it dissolves in thrice its weight of water. When dried on the
sand bath, and afterward exposed in a damp place, it ab-
sorbs. a little moisture from the atmosphere.

This salt combines with an excess of acid, and forms a Salt of sorrel.
- superoxalate, long known by the name of salt of sorrel. It
is very sparingly soluble in water, though more so than tar-
tar. It occurs in commerce in beautiful 4-sided prisms at-
tached to each other. The acid contained in this salt is
very nearly double of what is contained in oxalate of potash.

Suppose 100 parts of potash; if the weight of acid neces-
sary to convert this quantity into oxalate be x, then 2x will
convert it into superoxalate.

6. Oxalate of soda readily crystallizes. Its taste is nearly Oxalate of
the same as that of oxalate of potash. When heated, it °¢
falls to powder, and loses the whole of its water of crystal-
lization. Soda is said to be capable of combining with an

C 2 €XCESS

20

Oxalate of am- .

monia,

Specific gravity
ot solution of
oxalate of am-
monia.

ON OXALIC ACID.

excess of acid, and of forming asuperoxalate, I have not
tried the experiment.
7. Oxalate of ammonia is the most important of ail the
oxalates, being very much employed by chemists to detect
the presence of lime, and to separate it from solutions. lt,
crystallizes in long trasparent prisms, rhomboidal, and
terminated by dihedral summits. The lateral edges are
often truncated, so as to make the prism 6 or 8-sided.
Sometimes the original faces of the prism are nearly ef-
faced. hi

The taste of this salt is bitter and unpleasant, somewhat
like that of sal ammoniac. At the temperature of 60°,
1000 grains of water dissolve only 45 grains of this salt.
Hence, 1000 grains of saturated solution of oxalate of am-
monia contain only 43-2 grains of this salt. The specitic
gravity of this solution is 1°0186. As it may be useful to
know the weight of this salt contained in solutions of dif-
ferent specific gravities, [ have thought it worth while to
construct the following table:

of ammonia in 100|vity of the so-of ammonia im 100] vity of the so-
parts of the solution {lution at 60° || parts of thesolution }i ation at 60°.

Weight of oxalate|Specific gra-| Weight of soe ae

4°32 | 1:0186 | 1°5 | 1:0075
4: | 1°0179 i 1°0054
3°5 1:0160 0°5 | 100380
3° | 10142 0-4 1:0024
25 1-0120 0°3 | 1:0018
Ze 0°0095 0-2 1:0012

01 | 1°0006

Method of dee & To determine the composition .of these salts, I took

termining the
combustion of
the oxalates.

seven different portions of a diluted oxalic acid solution,
each weighing 100 grains, and containing 7 grains of real

~ oxalic acid. 'To each of these portions I added respectively

potash, soda, ammonia, barytes water, strontian water, and
lime water, till it ceased to produce any change. The h-
‘quid was then evaporated to dryness, and the residue, after
being well dried on the steam bath, was weighed. Each
of these salts contained 7 grains of acid; the additional

weight
e

ON OXALIC ACID. 91

weight I ascribed to the base. Hence I had the following
table,which exhibits the weight of each salt obtained, and
its composition deduced from that weight.

Composit on

Salts. Weight |——
obtained jAcid | Base

a eee |

Oxalate of Ammonia 9°4 | 4 | 24

Magnesia*--| 9°5 | 7B MEE a

pe

>

Soda. seven | 7 | AO

A YS a or | 7 \ 49

Potash .----| 15°6 | 7 | 36

i ee |

Strontian --| 17°6 heli 10°6

Barytes ----! 17°70 | 7 {10°0

The composition of these salts reduced to 106 parts is
given in the following table.

Component
parts of the
oxalates.

Ox. of Ox. off Ox. of Ox. of Ox. of Ox. of] Ox of
Am- | Mag-| Soda. |Lime.|Potash|Stron-} Ba-
Monia | nesia. tian. |rytes

Acid |74 45|73 68 63°63|/62'50|44 87|39°77/ 41° 1C

2c Ai SiS a ial, A vai aes
Base | 25°53! 26°32 36:37|37°50|55" 13 60°23'58°84

—— | ——— | —______ } -——_—— ————

otal]i00 |100 |100 |100 {100 |100 {100

But for practical purposes, it is more convenient to consider

* The oxalate of magnesia was obtained by neutralizing the oxalic
acid solution with ammonia, then mixing it with sulphate of magnesia,
evaporating the solution to dryness, and washing the insoluble oxalate of
magnesia with a sufficient quantity of water.

the

13
49

ON OXALIC ACID.

the acid as a constant quantity. The following table is
constructed upon this plan.

Component
parts the acid cd} Base. | Weight
being 100, of Salt.

Oxalateof Ammonia-> |100| 34°12 | 134°12
Magnesia -+ |100| 35°71} 135-71
Soda «+++++ 1100) 57:14] 157°14
——__—. Lime--«+-- |100| 60°00} 160-00
Potash «+++ |100| 122°86] 222°85
—————— Strontian -- /100]151°51 | 251°51
——— - Barytes ---- {1001 142°861 242°86

Oxalates retain 9. Tn the preceding statement, no account has been taken
little if any wa- 4

ter in a mode- Of the water of crystallization, which might still remain at-

ateha, tached to the salts, notwithstanding the heat to which they
were exposed. There is reason to believe, however, that
in most of them this water must ‘be so small, that it may be
overlooked without any great errour. Ovxalates of soda
and of ammonia, I have reason to believe, lose all their
water of crystallization at a moderate heat. This is the
case also with oxalates of lime and barytes; and I presume,
that the oxalates of strontian and magnesia are not excep-

except that of tions; but oxalate of potash retams its water much more

potash. : : AU SG 2 ;
obstinately. I believe that in this salt the weight of acid
and of base are nearly equal, and that when dried in the
temperature of 212°, it still retains nearly 10 per cent of
water ; but I have not been able to establish this opmion by
direct experiment.

"Oxalate of The composition of oxalate of strontian in the preceding

es table was so different from what I expected, that I repeated
the experiment; but the result was the same. This in-
duced me to combine strontian and oxalic acid in the follow-
ing manner: 100 grains of a solution containing 7 grains of
real oxalic acid were neutralized by ammonia, and the ox-
alic acid precipitated by means of muriate of strontian.
The salt obtained weighed 12-3 grains; of course it was
composed of

Acid 7 or 56°9 or 100
Base 5:3 43"1 75°7

ee

12°3 100°0 175°7
Thus

\

ON OXALIC ACID, 93

‘Thus it appears, that there are two oxalates of strontian, Two species.
One with dou-
ry _ ble the base of
water, the second by mixing together oxalate of ammonia the other.

aud wmuriate of strontian. It is remarkable, that the first

the first obtained by saturating oxahe acid with strontian

contains just double the proportion of base contained in the
second.

III. Decomposition of the Oxalates.

1. When oxalic acid, in the state of crystals, is exposed Crystallized
to heat, it is only partially acted upon, a considerable por- pire eg
tion escaping without alteration; but when an alkaline or in oxalates de-
earthy oxalate is heated, the acid remains fixed, till it un- ce ty
dergoes complete decomposition. ‘The new substances into
which the acid is converted, as far as my experience goes,
are always the same, what oxalate soever we employ. They
are five in number; namely, wafer, carbonic acid, carbonic p
oxide, carburetied hidrogen, and charcoal.

2. The water is never quite pure. Though no sensible w,.o,

roducts.

portion of oil can be perceived in it, yet it has always the
peculiar smell of the water obtained during the distillation
of wood; a smell which is usually ascribed to oil. It com-
monly shows traces of the presence of ammonia, changing
vegetable blues to green, and smoking when brought near
muriatic acid; but this minute portion of ammonia is pro-
bably only accidentally present. All the oxalates, which I
‘decomposed by distillation, were obtained by double decom-
position from oxalate of ammonia; and though they were
washed with sufficient care, yet I think it not unlikely, that
a minute portion of oxalate, of ammonia might continue to
adhere. Practical chemists know the extreme difficulty of
removing every trace of a salt, with which aaother has been
mixed.
The carbonic acid remains partly combined with the base, Carbonic acid.
which always becomes a carbonate, and partly makes its es-
cape in the form of gas.
The carbonic oxide and carburetted hidrogen make their cy ponic guides

escape in the form of gas: the charcoal remains in the re- carburetted hi-
oray Uogen, and

, j Shay charcoal.
colour: the quantity of it depends in some measure upon

the heat. Ifthe oxalate was exposed to a very violent heat,

no

tort mixed with the base, to which it communicates a

~

DA ON OXALIC ACID,

f

no charcoal at all remains. Hence it probably acts upon the
carbonic acid united to the base, converting it into carbonie
oxide, as happens when a mixture of a carbonate and char-
coal are heated.

Becomposition 3. 1 was induced to examine this decomposition with con-
of oxalate of

lime attentive- | ¥ s ae i ,
ly examined. nish the means of estimating the composition of oxalre acid ;

and I pitched upon oxalate of lime, as the salt best adapted
for the putpose I had in view. A determinate quantity of
this salt was put into a small retort,’and gradually heated
to redness. This retort was connected with a pneumatic
trough by means of a long glass tube, having a valve at its

siderable attention, because I conceived, that it would fur-

extremity, which allowed gas to issue out, but prevented
any water from entering the tube. The experiment was re-
peated three times. |

100 grs. yield 4, A hundred grains of oxalate of lime, when thus heated,

egie ss yield above sixty cubic inches of a gas, which is always a

a mixture of carbonic acid and ioflammable air, nearly in |
the proportion of one part of the former to three and a half
of the latter; reckoning by bulk. The specifie gravity of
the inflammable gas was 0-908, common air being 1°000;
it burns with a blae flame, and, when mixed with oxigen,
may be kindled by the electric spark. “The louduess of the
report depends upon the proportion of oxigen.

Mixed wih The smallest quantity of oxigen, with which it can be

re ce Ben mixed, so as to burn by the electric spark, is th; the com-

electric spark. bustion is very feeble, and is attended with uo perceptible
report. If the residue be washed in lime water, and mixed
with ith of its bulk of oxigen, it may be kindled a second
time: this may be repeated five times, after which the resi-
due cannot be made to burn. :

The combustion becomes more violent, and the report —

louder, as we increase the proportion of oxigen, aud both
are greatest when the oxigen is double the bulk of the gas.
As we increase the dose of oxigen, the combustion becomes
more and more feeble; and five parts of oxigen and one of
gas form the hmit of combustion on this side: for a mixture
of six parts of oxigen and one of the inflammable air will not
burn.

In

Pol
, ON OXALIC, ACID: 95

_In these experiments the results differ materially from Results differ
i : ; : according to
each other, when the proportion of oxigen used is small the proportions
and when it is great. Jam notable at present to account of oxigen,
for this difference, which holds not only with respect to this
gas, but every compound infiammable gas, which I have
examined. This difference makes it impossible to use
both extremes of the series: I make choice of that in which
the proportion of oxigen is considerable, as upon the whole
more satisfactory. The best proportion is one part of the
gas and two parts of oxigen. .The oxigen ought not to
be pure, but diluted with at least the third of its bulk of
azote, unless the gas be much contaminated with common
alr.
I have elsewhere detailed the method, which I follow in
analyzing gasses of this nature*. The following table ex-
hibits the mean of a considerable number of trials of this
gas with oxigen.

Mean result of

Measures of Measures of -} Carbonic acid | Diminution of the combus-

inflammable air, oxigen con- formed. bulikecy tion
consumed sumed.

—

-

That is to say, 100 cubie inches of the gas, when burnt,
combine with 91 cubic inches of oxigen; there are pro-
duced 93 inches of carbonic acid; and after the combustion
these 93 inches alone remain, the rest. being condensed.
Yfence we conclude, that the other substance produced was
water, ehieyee
This result corresponds almost exactly with what would
have been obtained, 1? we had made the same experiment
_ upon a mixture of 70 measures of carbonic oxide, and 30
measures of carburetted hidrogen, as will appear from the
- following table.

~

~ * See Journal, vol. XVI, ps 247

. : C whonie

~

26 ON OXALIC ACID.

Measures of |Measures off Measure c } ‘tminution
inflammable }oxigen con | -arbonica of
gasconsumed.| svmed. formed. balk.
Carbonic oxide 70 31/5 03 38°5
Carburetted hi- .
drogen ---- 30 60°0 30 60-0
Total --| 100 915 93 98°5

It wasamix- This coincidence is so exact, that I do not hesitate to con-

nce ape clude, that the inflammable gas, which was the subject cf

and 30 carbu- experiment, was in reality a mixture of 70 parts of carbo-

Sei hidro- nic oxide, and 30 of carburetted hidrogen. The specific
eravity indeed, which was 0°908,does not exactly agree with
the specific gravity of such a mixture; for 2} measures of
carbonic oxide, and one measure of carburetted hidrogen,
ought to form a mixture of the specific gravity 0°349, pro-
vided the specific gravity of carbonic oxide be 0°956, and
that of carburetted hidrogeu 0:600; but this objection can-
not be admitted to be of much weight, till the specific gra~_
vity of pure carburetted hidrogen is ascertained with, more
accuracy than has hitherto been done.

Its composi- The results contained in the preceding table enable us

aoe to determine the composition of this inflammable air with
considerable precision; for 100 cubic inches of it require 91
inches of oxtgen, and form 93 cubic inches of carbonic acid.
But it is known, that carbonic acid gas requires for its for~
mation a quantity of oxigen gas equal to its own bulk :’
therefore to form 93 inches of it, 93 inches ‘of oxigen gas
must have been employed; but only 91 were mixed with
thé” gas: therefore the gas itself must have furnished 2
quantity of oxigen, equivalent to the bulk of two cubic
inches, beside all the carbon contained in 93 inches of car-'
bonic acid,

This carbon amounts in weight to »+ 12°09 grains.
Two cubic inches of oxigen weigh+- -68

Total «+++ 12°77

ON OXALIC ACID.

But as 100 cubic inches of the gas weigh 28°15 grains, it
is obvious, that, beside the 12°77 grains which it furnished
to the carbonic acid, it must have contained 15°38 grains
of additional matter; but as the only two products were
carbonic acid and water, it is plain, that the whole of this
additional matter must, by the explosion, have been con-
verted into water. Its constituents of course must have
been’

13°19 oxigen

2°19 hidrogen

15°38
Adding this to the 12°77 crains formerly obtained, we get
the composition of the gas as follows:

Oxigen ++++++ 13°87
Carbon eeese* 12°09
Hidrogen «+++ 2°19

28°15
- which, reduced to 100 parts, becomes

Oxigen ++++++ 49°27
Carbon -eeees 42°95 |
Hidrogen ob ee
100°00
5. The residue which, remained. in the retort, after the
distillation was over, was a gray powder, not unlike pound-
ed clay slate. To ascertain its constituents, it was dissolved
in diluted nitric acid with the necessary precautions; the
loss of weight indicated the quantity of carbonic acid. TH
charcoal remaining undissolved was allowed to subside,
carefully washed by repeated affusions of water, and then
dried in a glass or porcelain capsule. It must not be sepa-
rated by the filter, for it adheres so obstinately, that it can-
not be taken off the paper, nor weighed. The nitric acid
solution was precipitated by carbonate of soda, and the car-
bonate of lime obtained was violently heated in a platinum
crucible. What remained was pure lime.
6. I shall now detail one of my experiments more parti-
cularly,

Constituent
principles.

Residuum,

89 grs. of oxa--

22 ON OXALIC ACID.

late of lime cularly, Ejighty-nine grains of well dried oxalate of lime
tg mare were exposed in a small retort to a heat gradually raised to
redness; the products were the following:
Grains,
45°6 cubic inches of gas* weighing. «+. 14:8
Water -eccsccccccevasccscecevesese G4
Residue in retort..--.sdececscegeees G24

83°60
NC@Gh afateln ste teielere §.4

Total eececseeee 89°0

The loss is obviously owing to the gas, which filled the re-
tort and tube when the experiment was concluded. We
are warranted therefore to add it to the weight of the gase-
ous products obtained,

Now the gas was composed of

Carbonic acid ++ 10°5 cubic inches = 4°9 grains.
Inflammable air 35°1 ++++++-++++ =Q°9

so that one third of the weight was carbonic acid, and two
thirds inflammable air. If we divide the 5:4 grains of loss
in that proportion, we obtain 1°8 grain carbonic acid, and
3°6 grains of inflammable air. Adding these quantities to
the weight obtained, we get for the weight of the whole
gaseous ieciaee

Grains,
eri: pro- Carbonic acid «+++ 6°7
is Inflammable air «+ 13°5_ H
290'°2
“Fhe 62°4 grains of residue in the retort were composed of
Grains.
Residuum, Lime: eceeerveesen 83°4

Carbonic acid ---+ 26°4
Charcoal «escceee 2°6

62°4

* The gas obtained measured 60 cubic inches, but 14°4 inches of these
were found to be common air, which had preyiously filled the retort and
tube; this quantitv was therefore deducted,

Now

ON OXALIC ACID. . 29

Now it is clear, that the 89 grains of oxalate of lime were
composed of

Duis 20,0 6.0 010)2)0,0,0 33°4
ACIE os ccncscoose 55:6

89:0

The acid was completely decomposed and resolved into the -
following products:

Carbonic acid «+++ 33°1 Piaducic of
Inflammable air ++ 13°5 mee grs. of
W ater eoeoeveeseseee 6°4 y g
Charcoal... .-++.«s 96

55°6

Pa

Had the experiment been made upon 100 grains of oxalic
acid instead of 55°6, it is clear, that the proportions would
have been as follows.

¢

Carbonic acide +++ 59°53 Propoitions of
Inflammable air- + 24°28 1€0 parts.
Watered aces chee, EL S4

Charcoul----.--+ 4°68

100°00

The most remarkable circumstance attending the decom-
position. of oxalic acid by heat is the great proportion of
carbonic acid formed; the quantity amounts to 6 tenths of
the whole weight of acid decomposed.

As the composition of all these products of oxalic acid is Constituent
known with considerable accuracy, it is obvious, that they ae Ti ae
furnish us with the means of ascertaining the constituents
of that acid itself,

59°53 grains of carbonic acid are composed of

Grains.
Oxigen seeees 42°36

Carbon e+eeee 16°67

7

59°93

24°28

sO ON OXALIC ACID.

24°28 grains of the inflammable air, according to the ana-
lysis given in a preceding part of this paper, are composed
of
: Grains.
Oxigen evees+ 11:96
Carbon ---++- 10°43
Hidrogen «+++ 1°89

24-28
11°51 grains of water are composed of

Oxigen eeveeeveen 9°87
Hidrogen-.+-+- 1°64

T1511

As for the charcoal, though it probably contains both
exigen and hidrogen as well as carbon, yet as the propor-
tion of the first two ingredients is probably very small, and
as we have no means of estimating them, we must at pre-
sent rest satisfied with considering it as composed of pure
carbon. |

When these different elements are coltected under their
proper heads, we obtain

Oxigen, Carbon. Hidrogen.
In carbonic acid «+ 42°86 16°67
Inflammable air -- 11°96 10°43 1°89
Water -e-eceseee 0°87 1°64
Charcoal «+++eee- 4°68

64°69 31°78 3°53

Elements) | Hence oxalic acid is composed of oxigen +--+ 64:69
eoceeeceeerseeeceseeresoevet 2s ee carbon eese 31°78

eooesesececcesevnes ee oneoreeoveers hidrogen ee 3°53

100°00

/

Confirmed by 7. The result of two other experiments on oxalate of lime
other experi- was yery nearly the same as the preceding. The following
ments, ule

ON OXALIC ACID. 3)

may be stated in round numbers as the mean of the whole.
Oxalic acid is a compound of

aise) sorte’ GA Mean in round
Carbon” +34. . 3" 92 numbers.

Hlidrogen «+--+. 4

——

100

8. The only other analysis of oxalic acid, with which I pjements ac-
am acquainted, has been given by Mr. Fourcroy, as the re- co-ding to

l f hi . igen t i : Gti ith tl > Fourcroy and
sult of his own experiments, in conjunction with those of y uguelih,
Vauquelin*., It is as follows:

Oxigen eserceneen Gof. ,
Carbon ---es-e- 13
Hidrogen +++-+++ 10

——

100

It gave me considerable uneasiness to observe, that my ex-
periments led to conclusions irreconcilable with those of
¢hemists of such eminence and consunmate skill; and it
was not without considerable hesitation, that I ventured to
place any reliance upon them. Iam persuaded, however,
that some mistake“has inadvertently insinuated itself into py45. cateula-
their calculations; since the carbonic acid alone, formed tions errone-
during the distillation of oxalate of lime, contains consi- °"*
derably more carbon than the whole quantity, which they
assign to the oxalic acid decomposed. Mr. Fourcroy in-
forms us, that oxalic acid is converted into carbonic acid
and water, when acted upon by hot nitric acid; and this
decomposition seems to have been the method employed,

to ascertain the proportion of the constituents of oxalic acid;
but the numbers assigned by him do not correspond with
this statement. For 10 parts of hidrogen require 60 of
oxigen to convert them into water, and 13 of carbon require

at least 33 of oxigen. So that instead of 77 parts of oxi-
gen, there would have been required no less than 98, to
convert the hidrogen and carbon into water and carbonic
acid, Itis true, that the surplus of oxigen may be con-

* Systeme de Connois. Chem, VII, 224. Trans. V1, 306.

' ceived

32

Ores, iron, sco-

riz, and fluxes, «

collected for
examination,

Fluor spar em-
ployed asa flux
at Drambon.

~

ANALYSIS OF IRON ORES, &c.

ceived to be furnished by the nitric acid; but if this be ad-
mitted (and I have no doubt from experience, that the nitric
acid actually does communicate oxigen), it is difficult to
see how the constituents of oxalic acid could ‘be deter-
mined by any such decomposition, unless the quantity of
oxigen furnished by the nitric acid were accurately ascer-
tained.

(To be concluded in our next.)

v.

Analysis of some. Iron Ores in Burgundy and Franche-
Comité, to which is added, an Examination of the Pig
Iron, Bar Iron, and Scorie, produced from them. By
Mr. Vavevue in*. ,

Me. Vauquelin, in the year 1805, having visited various
iron works in Burgundy, collected several specimens of
ores, pig iron, bar iron, scoriz, and fluxes, for the purpose
of subjecting them to chemical analysis, in order to ascer=
tain, whether it were possible to know from a comparison
of their composition, what takes place in the processes, to
which irap ores and cast iron are subjected. We shall give
here the leading results of this able chemist’s labours, and
the particulars of some of the processes he employed to ob-
tain these results.

I. Chemical examination of some fluor spars.

The spar employed as a flux at the mine of Drambon, in
the department of Coéte-d’Or, is of a yellowish white, and
tolerably hard. [It dissolves with effervescence in nitric
acid, and leaves a yellowish residuum, amounting to about
a fifth of its weight, which is composed chiefly of fine

* Journal des Mines, No, 119, p. 982. The whole of the paper,
of which this an abridgment, will be found in the Memoirs of the Nae
tional Institute. , x

sand,

ANALYSIS OF IRON ORES, &c. 33

sand, with a minute quantity of alumine and iron. The
solution, which is colourless, gives with ammonia a light,
flocculent, semitranspavent, yellowish white precipitate, in
which was recognized the presence of iron, a little alumine,
and phosphate of lime. It likewise contained some traces
of silex. 2

The spar of Pesme is compact, of a grayish white, and That at Pesme,
dissolves in nitric acid, leaving a residuum of about a twen-
tieth of its weight. A little iron, alumine, and phosphate
of lime, were eee in the solution.

From these two analyses it appears, that the fluors ana- Almost wholly
lysed consist almost wholly of calcareous matter, but that estate AE “tl
of Pesme is much the most pure. They show at the same most pure.
time, that the stones examined contain a small quantity of
phosphate of lime, which certainly does not amount toa five
hundredth part.

‘

Il. Analysis of the scorice of the iron works at Drambon.

Mr. Vauquelin begins with a chemical examination of Scoriz of
these scoriz, rather thar with that of the ores and smelt- Drambon-
ings, because these scorize include more foreign matters ina’

‘ smaller bulk.

They have a shining blackish colour, nearly resembling Physical cha-
certain oxides of manganese. Their weight indicates, that '¢tts.
a considerable quantity of metallic matter is left in them.
Some parts exhibit blebs of different sizes, others are com-
pact. Their fracture is crystallized, either needly or lami-
nar.

Five grammes [77 grains] of scoris, fused twice in suc- Analysed.
cession with an equal weight of caustic potash, communi-
cated to the alkali a very a green colour, when the mass
had been washed with water.

This green colour is known to be an unequivocal proof of Manganese,
the presence of manganese, and it is the best method we can
eniploy, to discover the slightest trace of this metal in any
substance.

All the washings, of the scorize thus treated were added Thisseparated,
together, and boiled, to separate the manganese. In pro-
portion as this effect took place, the Teac lost its green
colour, and the metal floated in it in the form of brown

Vou. XXI—SeEpr. 1808. D flocks,

34 ANALYSIS OF YRON ORES, &c.

flocks, which, when collected, washed, and dried, weighed
2 decig. [S$ grs.] amounting to 4 per cent.

Chrome sus- The alkaline liquor, freed from the manganese and fil-
ia tered, still retained an orange yellow colour, which led Mr.
Vauquelin to suspect the presence of chrome.

Silex and alu- For verifying this suspicion, it was necessary, in order to
or * facilitate the operations necessary for detecting the chrome,

tu separate the alumine and silex, that were in the alkaline
lixivium; and to avoid the presence.of muriatic acid, which
would have thwarted the end he proposed, Mr. Vauquelin
employed very pure nitrate of ammonia, instead of the mu-
9 yiate. Thus he obtained 2 cent. [0°3 gr.] of a mixture of si-
lex and alumine.
Carbonic acid He then saturated the liquor with very pure nitric acid,
Oe boiioe, Sages a little in excess, and boiled it for a quarter of an
hour, in order to dissipate the carbonic acid entirely,
Nitrateofmer- 'To a portion of the hiquor thus prepared he added a few
cared PEER. drops of the solution of nitrate-of mercury at a minimum ;
ric atid. but instead of these giving it a red colour, as is usual with
chrome, they threw down a white precipitate, which at first
he took for muriate of mercury, but it afterward appeared
to be phosphate of mercury.

Seu cw ter Tnstructed by this trial, he added to the remainder of the

threw down _ liquor limewater, which, when the acid was saturated, pro-

aay duced a flocculent precipitate. This had a slight tint of
yellow, which changed to a green on drying, a circumstance
that indicated some foreign matter in the phosphate of
lime. .

‘

Chrome. Desirous of discovering the cause of this colour, he heat-
ed the precipitate red hot in a silver crucible; in conse-
quence of which the green tint, instead of disappearing,
became more intense. He then fused a httle with borax
by the blowpipe, and the fine emerald green colour the salt
assumed confirmed his first suspicion of the existence of
chrome in the scorie from the refining furnace.

Oxide of The remainder of the precipitate, being treated with ni-

chrome with a tric acid, was not entirely dissolved ; a portion bemg left of

ae ON. Sa very deep green colour, which was nothing but oxide of
chrome mixed with a hittle silex, the particles of which being

, brought

ANALYSIS OF IRON ORES, &c. 35

brought together and hardened by the heat, it had lost the
eapacity of being soluble,

The solution was void of colour; and oxalate of ammo- Lime,
nia threw down from it a granylous precipitate, which when
washed and dried weighed 2 decig. [3 grs.], and was true
oxalate of lime.

The liquor from which the oxalate of lime had been pre- Phosphoric
cipitated, as has just been mentioned,. being evaporated to °"
dryuess, and the residuum calcined, yielded au acid, which
had all the properties of the phosphoric.

The first liquor, to which the limewater had been added Chrome,
to precipitate the phosphoric acid, was mixed with nitrate
of mercury recently prepared; when a brown yellow preci-
pitate was formed, which assumed a green tinge by drying
inthe air. The precipitate fused with borax gave it a very
fine green colour, which proved it to be a chromate of mer-
cury with excess of oxide.

Thus the presence both of chrome and phosphoric acid All these must
in the scorize from the refining furnace is demonstrated. ae existe |
‘These matters, as well as those that will be mentioned be- ae in He oi
low, existed in the pig iron, and previously in the ore, for |
nothing was added during the processes of working them,
from which these could ee: been produced.

_ After the chrome, phosphoric acid, manganese, and a Muriatic acid
portion of the silex and alumine, had been separated, OA cain id
Mr. Vauquelin dissolved m munatic acid the ferraginous part.

part, which had then a yellowish red colour, “He observed,

that, notwithstandiag the alkah had taken from it a great

deal of oxide of manganese, a perceptible portion of oxi-

genized muriatic acid was produced, as the dissolution went

on.

A white powder remained at ‘he, bottom of the liquor, silex, -
-which when washed and dried weighed 88 cent. [13:6 er.], or
‘about a fifth of the weight of the scorie. During the evapo-
ration of the liquor, which was carried to dryness, a portion
of the same substance was precipitated, which was freed by
means of muriatic acid from a little iron, that fell down with
at. This contained some traces of chrome, for it communi-
ogated to borax a plain green colour. It was silex. .

- Mr. Vayguelin precipitated the irgn from its solution by Lime.
DQ ammonia,

36

Manganese,
alumin-, and
lime.

Component
parts of the
score.

All these were
in the pig iron,

Ores examin-
ed.

Bog ores of
Drambon,

Chamfont, and
Grosbois.

ANALYSIS OF IRON ones, &c.

ammonia, and added to the filtered solution oxalate of am-
monia, which formed in it a pretty copious precipitate, that
was oxalate of lime.

The iron, while still most and in an attenuated state,
was treated with acetous acid, the mixture evaporated to
dryness, and the residuum redissolved in water. In the
clear and colourless liquor were detected by different means
the presence of oxide of manganese, and of alumine,
which had escaped the action of the alkali in the first ope-
ration, and of a pretty large quantity of lime, which the
volatile alkali had precipitated with the help of the oxide of
iron.

From these experiments, and the results they furnished,

it is evident, that the dross or scoriz of the refining furnace,
on which. they were made, are formed of, Ist, a large quan-
tity of iron oxided at a minimum; 2d, oxide of manganese ;
3d, phosphate of iron; 4th, chrome, probably in the state
of oxide; Sth, silex; 6th, alumine; 7th, lime, part of
which is perhaps combined with phosphoric acid.

It can scarcely be doubted, that all these matters were
contained, at least in part, in the pig iron that furnished
the scorie: the charcoal might have imparted to them at
most some lime, silex, and manganese; but the analysis of
the ores, and of the pig iron itself, will soon instruct us what
we ought to think on this point.

Ill. Examination of the bog ores.

The ores subjected to analysis by Mr. Vauquelin were,
Ist, those employed at the forge of Drambon. These are
in spherical nodules of different sizes, and some irregular

¢

fragments of limestone are observed among them. @d, |

those of Chamfont and Grosbois. These much resemble
the former. Those of Grosbois contain a pretty large quan~
tity of limestone. 3d, that of Chatillon-sur-Seine. This
is of an ochry yellow colour, in grains as small as millet
seed, and no limestone is seen among it, but it contains a

pretty large quantity of clay.

Mr. Vauquelin gives at Jarge his analysis of the ore of
Drambon, observing, that the other ores include the same

principles, though in different proportions; at the same

time

ANALYSIS OF IRON ORES, &c. 37

time the quantities he has assigned to its different compo- Quantities _
nent parts he gives only as approximations. sae Me Sn

Ten grammes [154°5 grs.] of the ore of Drambon, treat- 09,6 of Dram-
ed with caustic potash, assumed a very intense green co- bon.
lour, that communicated itself to the water in which it was
lixiviated. The ore being subjected to the same operation
a second time, it produced a similar effect, but less strik-
ing.

The liquors were boiled, and 3 decig. [4°6 grs.] of man- Manganese,
ganese fell down, containing a little silex, and an atom of ih shbaa
iron.

The solution retained a slight yellow colour, as in that
from the scori#; and Mr. Vauquelin, supposing this colour
to be produced by the same substance, saturated it with ni-
tric acid. With this liquor he mixed a solution of nitrate
of mercury made without heat ; when it became colourless,
and a white precipitate fell down, that did not give any tinge
to glass of borax.

As the liquor contained an excess of acid, it was sus+ Chrome,
pected, that, if any chromate of mercury had been formed,
it was held in solution. Accordingly a few drops of a so-
lution of pure potash were added, and a brown red preci-
pitate was obtained, which, being fused with borax, gave
it a fine emerald green. This indicated, that it was chro- and perhaps
mate of mercury, perhaps with a little phosphate of the ig ici
same metal.

The liquor being still acid, and retaining some mercury
in solution, Mr. Vaugnuelin imagined it still contained
chrome. He therefore added a few drops of nitrate of sil-
ver, in hopes of obtaining a crimson red precipitate; but
what fell down was of an orange yellow, and did not give a
green colour to borax. It was phosphate of silver. Potash Phosphoric .
added to the remaining liquor produced a very bulky, floc- ‘ann
culent, lemon-coloured precipitate. This acquired a green
hue as it dried, and was chromate of mercury, containing Chrome, a'u-
silver, with a small quantity of alumine and silex. APSF ee
_ The mercury was separated from the silver in a gentle
heat by means of muriatic acid, diluted with two parts of
water, that it might not dissolve the muriate of silver. At
once the precipitate became white, and the acid green. The Chrene.

olution

38 ANALYSIS OF IRON OBES, &c. ;

solution being evaporated to dryness left a blackish matter,
whic gave a very iiue green colour to borax,
Ou treating afterward with sulphune aeid, and precipi-
tating by limewater, Mr. Vauquelin obtained 1°5 per cent.
Magnesia. of magucsia. Though this earth was found in the pig iron
from each of the five boy ores, he does wot venture to as«
sert, that it exists in aij: but he observes he has much more
reasou to think, that chrome and phosphorie acid are cen
stanily found in it.

Similarity of Reflecting, that oxide of manganese, chrome, and mag-
eS es

these ores to esia, which he had just obtamed, were found likewise In

meteoric

stones : aerolites, Or meteoric stones, he questioned whether it were

not possidle for iron ores, to have contributed in some way

or other to the formation of these stones. This idea led him

put no nickel to examine, whether nickel likewise did not occur in bog
in them. ores; but his researches were fruitless,

Component Frow what has been said it follows, that the bog ores ana-

et lysed_were composed of, Ist, iron; 2d, manganese; 3d,

: phosphoric acid; 4th, chrome; 5th, magnesia; 6th, silex;

“th, alumine; and 6th, lime. The chrome, phospkori¢

acid, and maguesia, had not before been noticed in these

ores.

lV. Examination of the iron, that. sublimes and collects. é in the
chimneys of the refining furnace.

Tron sublimed This iron is found adhering to the sides of the chimneys
ee poi sated of the refining furn nace in the shape of stalactites, which are
haces, sometimes more than a foot long and three or four inches 1 in
diameter. They are for med af agelutinated grains, red in
their fracture, leaving great intervals between them, and
having but a slight action on the magnet.
ja _.. We shall not give the particulars of Mr. Vauquelin’s ana~
lysis, but he concludes it with the following words.
contains oxide ~ * In this sublimed iron then,. there are axidé of manga-
big oui nese, silex, phosphoric acid, and above all a gyeat deal of
ric acid, and» chrome. ‘These matters therefore have been volatilised by:
much chzome, the caloric, either by being dissolved in this fluid, or by
yielding to the impulse of the current of air; but in either
case they have issued from the Pig iron, during the process

of a (a
V.

ANALYSIS OF IRON ORES, &c. 39

V. Examination of the pig iron of Drambon.

Mr. Vauquelin having found oxide of manganese, chrome, Pig iron of
phosphoric acid, and earths, in the scoriz of the refining Drambon.
furnace, it was natural for bim to infer, that he should find
the same substances in the pig iron; since it is this, that
furnishes these scoria, at least for the most part, in the
process of refining. This fact was fully confirmed by ana-
lysis.

He proceeded in. the following way. Ten gram. [154° Analysed.

-grs.] of gray_pig iron of Drambon reduced to filings were
dissolved in sulphuric acid diluted with six parts of water.

The hidrogen gas evolved during the solution was collected. 4 very fetid
Tt had an Extranely fetid smell, very much resembling that ~ Mikael
of rotten garlic; but still more that of phosphuretted hidro=

gen gas, though it Had icentain pungency, which the phos-

phuretted hidrogen has not. The nature of this gas will be

noticed presently.

_ The residuum was of a very deep black, and diffused an Residuum.
extremely strong smell of phosphorus. It weighed 53

cent. [8°2 grs.] or a little more than a twentieth of the iron

employed.

The upper part of the bottle in which the solution was Oil formed.
made, and the tube through which the hidrogen had passed,
being so greasy that water would not adhere to them, Mr.
Vauquelin suspected, that oil had been formed ; a fact first
announced by Mr. Proust a few years ago ona similar oc-
casion, and which Mr. Vangueiin adds he had himself ob-

served before that, when dissolving certain kinds of tin.”

- To know whether any of this oil remained in the resi- Residuum
duum of the pig iron dissolved in the sulphuric acid, he gee aa
boiled it with highly dephiegmated alcohol, and filtered the ‘a
liquor hot.

This alcohol became milky on the addition of water; and more'oil ob-
being exposed to a gentle heat, drops of oil separated from easine

- it as the alcohol evaporated. This oil was clear and trans«
parent; it hada shight yellow tinge; and its tasie was hot
and a little pungent. It appeared to be of a middle kind
between the volatile and fat oils.

‘ After

40

The residuum
déflagrated
with nitre.

Silex,alumine,
and phosphoric
acid separated,

Chrome.
“a

Lixivium.

Residuum
treated with
muriatic acid.

Tron with silex,

Contents of
the iron.

Probable rea-
son ot our ig-
norance of the
causes of the
badnes sofiron.

ANALYSIS OF IRON ORES, &c.

After the oil it contained ‘was separated from the resi-
duum of the pig iron, this residuum was deflagrated in a
silver crucible with a little very pure nitrate of potash, the
matter was washed with distilled water, and a hght yellow
liquor was obtained. This was mixed with a solution of the
nitrate of ammonia, to precipitate the silex and alumine
presumed to be contained in it; anda small quantity of
these was separated. Limewater added to the filtered li-
quor formed in it a copious precipitate, which had all the
characters of phosphate of lime.

To ascertain whether there were any chrome in this li-
quor, it was first boiled to volatilise the ammonia, and a few
drops of nitrate of mercury were added, which was preci-
pitated of a brown yellow, in consequence of a little lime
remaining. This precipitate however gave a green colour
to borax, which proves, that it contained chrome.

The lixivium from the residuum of the solution calcined
with nitrate of potash then contained phosphoric acid,
chrome, and silex mixed with a httle alumine. 'There was
likewise in it an atom of manganese.

The residuum having been thus treated and lixiviated.
was in the form of a reddish powder, which was. dissolved:
for the greater part by muriatic acid. There remained how-
ever a small quantity of grayish matter, which was silex.
mingled with chrome, for it gave a very decided green co-
lour to borax. ;

The muriatic solution contained a great deal of iron,
It assumed the consistence’ of a jelly on evaporation,
which demonstrates, that it contained silex ; and it is pro-
bable, that-a little chrome and manganese too were con-
cealed jn it.

It appears then, that this pig iron contains, beside car-
buret of iron, phosphuret of iron, manganese, chrome, si-~
lex, and alumine. Next to the iron and carbon, it appeared
to Mr. Vauquelin, that the phosphorus was most abun-
dant. It is then in the residuums of the solations of pig”
and bar iron that we must henceforward look for phospho-
ros, rather than i in the solutions themselves, as has hitherto
been done. Probably the neglect of examining these. resi-
duums with sufficient attention 1s the reason of our re-

maining

ANALYSIS OF IRON ORES, &c. Al.

maining so ignorant of the causes of the bad quality of

iron.

- My. Vauquelin however admits, that there is likewise a Phosphorus,
small quantity of phosphorus converted into acid, and dis-

solved in the liquor, probably in the state of phosphate of

iron, by means of the sulphuric acid. It appears to him,

that, when the sulphuric acid is less diluted with water, a

larger quantity of phosphorus dissolves in the liquor. .To

separate this phosphate of iron, he dilutes the solution with Separation of
seven or eight parts of water, and mixes with it carbonate the phosphate
of potash, till almost the whole of the acid.is saturated, A ii
white precipitate is formed, more or less copious according

to the kind of iron employed; and at the expiration of a

few days it grows yellowish. This precipitate, washed and

dried, he treats with potash in a silver crucible at a red

heat: he then lixiviates the matter with water, and, after

having saturated the liquor with nitric acid, and boiled it to

expel the carbonic acid, he adds limewater, which commonly

forms a white flocculent precipitate, or semitransparent if
phosphoric acid be present.

He has likewise found a large quantity of chrome in the Chrome oxi-
precipitate produced by easlinaeae of potash in the solution genized and
of pig iron by sulphuric acid. It follows therefore, that a palo aan
chrome as well us phosphorus is oxigenized and dissolved in
sulphuric acid. _ |

It is advisable to test the alkaline liquor with nitrate of Cason,

ammonia, previous to saturating it, in order to know whe-
ther it hold any silex or alumine in solution. If it do, a \
sufficient quantity should be added to precipitate these
earths, after which they must be separated by the filter:
for without this precaution they would be precipitated by
the lime, and might be mistaken for phosphate of lime.
Mr. Vauquelin has found very evident traces of this salt in
the pig ion of the works at Drambon, though he employed
‘sulphuric acid diluted with six parts of water to dissolve it:
there was much less however, than remained in the residuum
of the solution. ‘This was the only kind of pig iron he ex-
amined, but he conceives it probable, that all the irons
fr ‘om bog ores contain the same foreign matters.

Vi.

42... [AMALYSIS OF IRON ORES, &c.

VI. Examination of the bar iron of Drambon and Pesmes.

Cold shortiron Mr. Vauquelin dissolved 5 gram. [77°2 grs.] of ‘cold short

sca aac iron of Dranibon in sulphuric acid diluted with five parts of

Hidvogen gas, water. He collected the hidrogen gas, that was evolved of
during the dissolution, and found it to have exactly the
same smell as that of the gas from the pig iron, but not
quite so powerful.

Residuom. The residirum left by these 5 gram. was much less co-
pious than that of the pig iron, and appeared likewise not to
be of so deep a black. While it was wet it emitted a very
strong fetid smell, analogous to that of hidrogen gas. It
weighed 15 cent. [23 grs.], amounting to 3 per cent. The
solution of the irou had the same smell, which was not dis=
sipated but by evaporation.

‘Phosphorus. A few particles of this residuum, thrown on a burning
coal, emitted a white vapour, with a smell resembling that

of arsenic and phosphorus. Heated red hot im a silver crue |

eible, it burned“with flame, and left behind a yellowish
powder. This was mixed with a little caustic potash, cal-
cined, and lixiviated. The liquor being filtered, saturated
with nitric acid, and subjected for a few minutes to heat,
limewater was added, which threw down a white flocculeat
precipitate, consisting chiefly of phosphate of lime, but
with an atom of silex and perhaps of alumine.

It is certain from these experiments, which Mr. Vauque-
lin repeated several times, that the iron of Drambon,
though it is considered as of pretty good quality, contaims
very perceptible traces of phosphorus. He likewise found
some slight traces of it in the solution by sulphuric acid.

Tron of Pesmes Pbe iron of Pesmes aflorded nearly the same results.

ie better qualie The residuum however was less by one half, amounting only
iron is very tough, and is reckoned one of the best in
Franche-Comté.

“os

VII. Of the hidrogen gas. |

The fetid hie Various experiments, which Mr. Vauquelin made by the
drogen gas. help of oxigenized muriatic acid on the hidrogen gas evolved
from

to 13 per cent; and it contained less phosphorus. This

ANALYSIS OF TRON ORES, &e. 43°.

from the pig and bar iron, led him to conclude, that phos-
phorus is the chief cause of its fetid smell.

VIII. Recapitulation and inferences.

‘From the experiments I have relatéd, says Mr. Vatique~ Generai con-
lin, it follows: clusions.

1. That the five sorts of bog ore I analysed are composed
of the same principles, which are, beside iron, silex, alu
mine, lime, oxide of manganese, phosphoric acid, magne»
sia, and chromic acid.

2 That the five sorts of ore having been taken at a_vene
ture from places tolerably distant from each other, itis pros
bable, that all ores of the same kind contain the same
si bstaices.

3. That these ores want only nickel, to contain the same
substances, as the stones that have fallen from the atmos
sphere.

4. That part of these substances remains in the pig iron,
and probably in larger quantity in cast iron, which may be
the cause of its greater hardness and brittleness.

5. That the greater part of these substances is separated
during the refining of the pig iron, when this operation is
well executed; since they are found in the scorix, and in
the sublimed iron that adheres to the insides of the chim-
neys of the reining furnaces.

6. That traces of them however ate found in bar iton of
good quality; and that probably chrome, phosphorus, and
manganese, are the chief causes, that render iron het short
er cold short.

_7. That the process of refining merits the greatest atten- The quality of
tion from iron-niasters; since it appears, that the good qua- apts ar "
lity of iron depends on its skilful execution.

8. That the presence of phosphorus and of chrome is ‘to
be sought for not in the solutions of pig and bar iron alone,
but also in the residuums of their solutions,

9. That by the union of hidrogen and carbon during the
dissolution of iron, and particularly of gray cast iron, an oil
is formed, which, in conjanction with a small quantity of
phosphorus, communicates a fetid smell to the hidrogen gas
that dissolves thein.

va 10. That

ah ON ADRIANOPLE RED, &c.

-10. That itis to these two substances the hidrogen gas
owes its properties of burning with a blue flame, and being
heavier than when pure.

11. Lastly, That the oil.and the phosphorus are separated
from the -hidrogen gas by oxigenized muriatic acid, which
destroys them. .

Vie.

Qn the Maddering of Cotton and Linen Thread, and Dyeing
them Adrianople Reed and other fixed Colours; and on Spon-
taneous Inflammations: by Joun Micnaen HaussMAnn*,

Fixing colours In order to proceed to the dyeing of cotton and linen.
en thread. : é :
thread all sorts of fixed colours, nothing is necessary, but to
fix on the thread, in any manner whatever, mere or less
alumine, after having given it a slight coating of oil. The
complete success of the result however depends on certain
modifications to be observed in the processes.

The various-experiments I had made in the art of dyeing
had rendered me so familiar with trials on a small seale, that
at length I found none of them fail. It is not till since my
paper on maddering was published in the Annales de Chi-

Oils do not re. mie, that I experienced difficulties in the application of oils,

pie Bh eae wheu operating in a larger way. The linseed oil, which had.

solution ofalu- always afforded me a milky mixture in limited proportions

ee with the alkaline solution of alumine, then speedily separ-

ge quanti- , ’ ;

ties. ated, when I was desirous of making a pretty large stock,
and the impregnation of the skeins became impracticable
under these circumstances. It was the same with all the

Fish oil best. other fat oils: fish oil, indeed, continues mixed a pretty long
time, but its smell is too offensive.

Drying oils ‘To remedy the inconvenience of the separation of the oil

petig with suc- +) the alkaline solution of alumine, I had recourse to drying
oils, or those boiled with metallic oxides. Linseed oil,

boiled with ceruse, minium, or litharge, by means of water

* Annales de Chimie, vol. XLVI], p, 233. 7
Ga to

ON ADRIANOPLE RED, &c. 45

to prevent its combustion, dissolves a good portion of oxide
of lead, and continues mixed with the alkaline solution of
alumine in a milky form, as long as is necessary for the im-
pregnation of the skeins. If this mixture be used in the
proportions and manner pointed out in my memoir, and fol-
lowing strictly in every other respect the process as I have
described it, fine and permanent colours cannot fail to be
obtained. However, notwithstanding the simplicity of the But dangerous.
process, I can no longer recommend its use, because it has
exposed me to the danger of a fire, and I will relate in what
way.

-In order to see whether red cotton, which was not oui Cotton thus
ciently fixed, might be rendered so by impregnating it with sree sage

took fire spome
a mixture of an alkaline solution of alumine and boiled lin- subi

seed oil, containing an excess of the oil, drying it, and’then r
boiling it a very jong while in bran water, I mixed the alka-
line: atihien of alumine in the proportion of an eighth, a
twelfth, and a sixteenth of boiled linseed oil. With this
mixture I impregnated a few hanks of dyed cotton, which,
after being left to dry a whole summer’s day in the open
air, were laid on a rush bottomed chair, that stood in the
window of my closet. Finding myself indisposed that day,

‘T went to bed at seven o'clock. My children went into my
Closet for some papers, an hour after I had left it, and per-
ceived no heat or smell in the cotton, to indicate a com-
mencement of burning. All the workmen had gone to bed,
and were fast asleep, when one of the watchmen of the
bleaching ground, seeing a great light in my ‘closet, gave
the alarm of fire, and sell us all we een twelve betel one
o'clock. My sons, knowing that I was not able to get out
of bed, and unwilling to lose time in searching for the key,
broke open the door of the closet, which was in a detached, .
wuinhabited buildiag. They went in, notwithstanding the
thick smoke and insupportable smell of the oily combustion ;
and found the chair with the cotton burning so furiously,
that the flames rose to the ceiling, and had already cracked
the glass, and set fire to the window-frame. They at once
presumed, that this commencement of a fire could proceed
only from the spontaneous inflammation of the cotton im-

pregnated

as ON ADRIANOPLE RED, &e.

premnated with boiled oil, since no one ever went into the
closet with a lighted pipe, or any thing else burning. 7

This not be- As I found, that several persons belonging to the manu-
lieved by ma- : ; : : CAEN
nye factory did not credit this explanation, I again impregnated

Tried again, a few dozen hanks of some old cotton, that had not been
well dyed, in the same manner as I had done the cotton
that was burned. These I set to dry in a simi ar manner in
the open air; and as it threatened to rain, ordered them to
‘be hung upon a line under a penthouse, directing one of the
-watchmen to look at it every quarter of an hour during the
night, and throw it into a bucket of water, as soon as he
perceived it begin to heat. But this man could not believe
the possibility of the cotton’s taking fire of itself, as he af-
terward confessed to me, and walked through the manufac-

Took fireas tory without once looking at the penthouse. At length

before. however he returned to lie down, and found by the great
light he saw, that what I had foretold in case he was negli-
gent had taken place. Finding the cotton as well as the
line was burned, he took the bucket of water to extinguish
_ the posts, which were already on fire.

Experiments . Though these two accidents did not at all surprise me, I

on spontaneous could the less forgive myself for the first, as, in order to pre-

ce DEAF ON vent similar accidents, | had made some experiments on
spontaneous combustions at a public house fifteen years be-
fore. On that occasion I had spoken of the probability of
fires being occasioued by heated substances, or substances
that have a telidency to heat, and which are thoughtlessly

Substances Ji-. Put in places capable of being set on fire. The substances

able to it. I mentioned to those of the company, who were not suffi-
ciently acquainted with the phenomena of spontaneous com-
bustion, were roasted coffee and chocolaie nuts; fermented
plants; ointments made with metallic oxides put hot into
wooden barrels; bales of raw cotton, as well as woollen
yarn or cloth packed up warm, and even linen when ironed,
and put away in drawers yet hot; and lastly substances of
every kind impregnated with boiling oil, as silk or gotton.

iui hecsial I showed them besides, that in all circumstances where the
attraction of oxigen of the atmosphere is rapidly attracted and absorbed
oxigen. . by any cause, the caloric or heat, which serves as a base to
_the.oxigen, and gives it the properties of a gas, is given out

in

i"

a eee

ON ADRIANOPLE RED, &e. ‘a7

‘Ynsach abundance, that, if the absorbing substance be ca-

pable of taking fire, or surrounded by inflammable matters,
spontaneous combustion will'take place.

To confirm what 1 had said of the theory of these sorts Experimentsin

of combustions to those present, who were net familiar with =
chemical operations, I performed the followimg experiments.
3. The inflammation of a mixture of sulphur and iron
filings kneaded with water. 2 That of boiled linseed oil
by highly concentrated nitric acid. 3. That of phosphorus
by atmospheric air, as well as in pure oxigen gas, placed for
this purpose on a china saucer over boiling water, in order to
‘separate its particles by fusion without having recourse to
rubbing it. 4. That of phosphuretted i gas by the
contact of the atmosphere, an imitation of the Jack witha
lantern. 5. The combustion of pyrophorus, thrown imto
‘the open air, and into pure ‘oxigen gas. 6. The reduction
of roasted bran, put hot into a coarse bag, to an ignited
‘coally mass by the action of the atmospheric air,

I was not ignorant, that essential or volatile oils become Attraction of
resinous, and that drying oils boiled with metallic oxides snipe Dy ae
grow thick and even hard by their combination with oxigen; ;

‘and this was the reason why my hanks of cotton impreg-
‘nated with a mixture of boiled linseed oil were exposed a

‘whole day to the air, hung separately on poles: but: I sup- That in the

posed they were then saturated with oxigen, and conse- Cotton suppe-
sed to be satu

“quently incapable of occasioning the least accident. I felt tated with it,

, “my self so secure in this respect, that I] have several times

‘dried a great deal of oiled cotton in hot rooms; and it was
owing to chance alone, that it was never put together, till

/

: ‘the moment when it was washed in order to he dyed. It is Owing in part

‘possible however, that the proportion of a thirty-third part ef perhaps to the

boiled linseed oi! mixed with the alkaline solution of alumine gia ears
yht be insufficient, to excite spontaneous combustion in

, hanks put together after being dried. If therefore a precaution.

“edited Were inclined ‘td employ a mixture of boiled linseed
“oil end the alkaline solution of alumine, on account of the
sino} licity of the process, he should take the precaution, to
ae hanks remain spread separately on the poles, till the
pet of their being washed previous to dyeing; which, in
‘conjunction with the brightening, would remove all the ex-
' CESS

48

ON ADRIANOPLE RED, &c.

_cess of oil, leaving none but what was completely saturated

Simplest
brightening for
Adrianople
red.

Process with-
Out danger.

with oxigen, and then there would be nothing to fear.

Since the publication of my memoir, I have likewise
satisfied myself, that the simplest brightening for Adria-
nople red, by which the brightest and most lasting colours
are procured, consists merely in boiling for a very long
while with bran-water in a covered boiler, with a tube in the
middle of the cover, to let out the steam, and prevent the
burstmg of the vessel. Care muft be taken however, to
change the water as often as it grows red, which wiil be two

or three times in the beginning of the boiling; otherwise

the thread would be continually taking up the mii particles,
which the bran-water had removed, and a bright colour
could not be obtained.

All danger indeed might be avoided, without much de-
viation from the simplicity of my process, whether the hanks
were heaped up or not. Nothing more is necessary for this,
but to give it a coat of olive oil in a very attenuate state, at
two different times, after having well stecped it in an alka-
line lixivium, washed, and dried it. For this purpose a
lixivium of the subearbonate of potash or of- soda is to be
made of the strength of 1° or 13° on the saltpetre areometer.
This must be tried, by mixing with it a few drops of olive
oil, to see whether these produce a milky mixture, or rise
and float uncombined on the top; for as the alkali may
contain more or less foreign matter, the lixiviam must be
weakened, or strengthened by au addition of alkali, as it is
absolutely necessary, that it should assume a milky appear-
ance on the trial with ‘oil, When the lixtvium is of a proper
strength, thirty-two parts are to be mixed with one of olive
oil, at first by little and little, and afterward more quickly,
stirring it continually the whole time. This milky mixture
keeps pretty long, and if the oil begin to rise to the top in |
the form of cream, the mixture must be stirred afresh. The
impregnation of the thread ought to be entrusted to work-
men who are most expert,in this process, because the accu~
rate distribution of the oily parts has great influence on the
evenness of the colour. Each workman should take only asuf-
ficient quantity of the milky mixture in any kind of vessel,

_ #0 as to be able easily to work it with all possible dexterity

as

ON ADRIANOPLE RED, &C.

as many hanks as he can wring out with facility. Thus he
will go on, taking constantly the same number of hanks,
and the same quantity of milky mixture. What he wrings
out he will put into a separate vessel, and restore to it by his
eye the quantity of oil the thread has absorbed, if the trifling
value of this residuum, which will contain but little oil, do
not induce him to throw it away. Theimpregnation may be
performed in the whole quantity of milky mixture, but then
the quantity of olive oil, that the hanks have absorbed, will
continually require to be replaced by the eye, as soon as the
intensity of the milkiness appears to be diminished: the art
of doing this however is easily acquired by practice. After
having dried all the hanks together, they are to be impreg-
nated a second time, in the same manner as before, but
without washing them first: and when they have been again
dried, they may be impregnated without previous washing,
once, twice, or three times, with the pure alkaline solution
of alumine without oil, in the manner described in my mee
moir. When they come to be dyed the colour will be more
or less deep, in proportion to the number of impregnations.
To obtain light tints however, and at the same time even,
it is better to impregnate them three times, weakening the
alkaline solution of alumine proportionally. The thread
might also be impregnated with this' solution, either strong
or weak, three times following, without previous washing ;
which would greatly diminish the number of operations, that
are certainly tedious and troublesome: but in this case the
solution must be examined from time to time, to see whether
what the impregnated and dried thread discharges into it
do not render it too strong.

49

For light tints.

On redyeing red colours, it must be recollected, whether Redyeing reds.

they were brightened by boiling in bran-water, or by means
of soap and alkalis. In the first case tley grow deeper by at-
tracting the colouring particles of the madder; in the second
they are weakened, and lose their excess of alumine, without
which repeated dyeing produces no effect. The removal of
this excess of alumine may be prevented, by substituting for
soap and alkalis, in order to produce crimson tints, a portion
of the alkaline solution of alumine, which is to be added to
the bran-water toward the end of the brightening, The

Vou. XXI—SeErt. 1808. E true

Real Adrian--

50 ; ON ADRIANOPLE RED, &c.

ople reds ree true Adrianople reds become much deeper on dyeing agains
ch by and are then browned by the test of boiling in a lixivium of
lie. wood-ashes. Before they are’redyed, this changes they. very
little. In general reds are browned to more or less disac>
vantage, in proportion to the longer or shorter time they
Turks use fish have been boiled in the brightening. As the real Adrian-
oil. ople reds have a strong smell, the Turks perhaps use fish oil,
which they add directly to the alkaline solution of alumine,
or mix with a very weak lixivium of alkaline carbonate.
Process admins ane processes for Adrianople reds may be infinitely va-
of great varia- yjed; for in whatever manner, and by whatever acid or alka-
Fak line solvents the alumine is fixed ip the thread, after having
given it a slight coating of any kaw of oil, we cannot fail to
obtain reds more or ie bright, in proportion to the care em-
ployed in maddering and hee ob a ¥
Oils mixwith ‘Lhe reason why the oils, which very easily combine with
a weak solution caustic alkalis and form soap, de not mix with concentrated

ee ae lixivia of alkaline carbonates, while with the same lixivia
witha strong. greatly diluted they form a kind of artificial milk, appears
to be the more difficult to explain, as we might at least sup-
pose, that there is a tendency to combination in these milky
mixtures. A simple suspension of the integrant particles
of the oil, that should take place in the diluted lixivium

preferably to the stronger, is not more explicable.
It remains for me to apologize for a misstatement, I had

Mistake cor-

rected. made with regard to the fabrication of the true Adrianople
red cotton used in the manufactories. What was shown to
ine was of very inferior quality; but I have since seen some
of the finest and most ‘permanent dye: hence I conclude,
that the manufacture of the Turks, like that of all other
nations, is according to the price the purchaser will give for
it.
Guerrwbethers I must not omit to observe likewise, that among the cot-
sodatend to ton I had burned, there was some both times, that had been
produce the impregnated with the mixture of weak lixivium of carbo=
spontaneous : 5 ys °
combustion, or nate of soda and boiled linseed oil in the proportvons of an
say” topre- eichth, a twelfth, and a sixteenth part. It remains to be
: proved, whether this cotton will take fire sooner than that,
whiclr is impregnated with a mixture of the alkaline solu-
tion of alumine and boiled linseed oil in the same proportions.

As

y)

Vichaloorts Polos Jontrnal VoldET PL 2. p51.

. 2 3 jr 0): ‘ ‘ ee
5 WM, “A lordyj covet: von of VL rab Ww) Lune Kiipers
. 7

==

if

| in
:

Hi

OM

M” Henry Wards Compensation Penilulur.

| | i l

MM” Furniss
Aur Tight Door Hing v.

MODES OF EQUALIZING ARCS OF VIBRATION, Si

As this last mixture is capable of attracting in some degree
the hamidity of the air, I should rather thiak, that the cot-
ton treated with the first is more liable to take fire*.
- The experiments | have continued to make on the use of !n galling per
<b haps gallate of
alls, i in the manufacture of Adrianople red, lead me to be- A airs.
Jiev e, that the alumine is fixed in the cotton in consequence ed, and after
ng the formation of a gallate of alumine, from which the “ecomposed by
allic acid i (is afterward Pocted by an alkaline carbonate
vious to the dyeing. As soon as I have satisfied myself
f the truth of this supposition, I will not fail to publish an

ecount of 1 my experiments,

—=—=——

eat ie Pe VL.

Pains of icidions Sor equalizing the long and fhort Arcs
| of Vibration in Timekeepers ; by Mr. Witiiam Ha RDY,
° 29 Coldbaih Squarete.

oT HE equalizati ion of the time of different arcs of era- Equalization
E ‘tion, of the balance of a time keeper having lately given rise mths shed
ee ‘to x3) much. diseussion, I beg leave to offer for the approbation ed three ways.
e “of the Society three different modes of obtaining this end.
pe we The first method is by a straight spring placed edgewise ist method.
a “acrossthe diameter of the impelient pallet a, Pi. 11, fig. 2and
3 and screwed at the end opposite to the direction of ibe
wheel, on its approach toward the centre of this pallet; at
e other extremity of this spring is a flat face, or curved
Ie tice, to receive the approaching tooth of the escape

_ wheel, which gives the impulse; this spring acts between
ti yok pins Pedi in the pallet near its end. By reducing
his spring to a certain degree of strength, so that it may

uy ield a little to the force of he wheel j in giving the impulse,

he different vibrations will be performed i in the same time;

ike the proper degree of strength can only I be determined by

repeated tnals. This method possesses besides this farther Advantage.
ay eee, that the acting surfaces are not so liable to bei in-

ee A * Pertiags not, for this very reason. T.

et Transact. of the Society of Arts, vol. XXV, p. 113. The silver
» ae of Phegpovicty was voted to’ Mr, Hardy for this invention. ;
E2 jured

t '
—
tee.

$2

2d method:

3d. method.

MODES OF EQUALIZING ARCS OF VIBRATION,

jured by the drop of the wheel upon the spring, as upon a
solid surface, nor the vibrations of the balance so much dis<
turbed by the impulse.

The second method is by a straight spring be, fig. 1 and 4,
screwed to the under part of the cock, placed edgewise and
diametrically over the cylindrical spring, and having a piece
cut out to clear the arbor of the balance. This straight,
spring is at one extremity fastened to the end of the pendu-
jum-spring, and, at the other extremity, its elasticity is re-
duced so as to yield a little before the pendulum-spring
operates, On the opposite of the cock, where the spring is
screwed, is fixed a stud d projecting downward,and. having a
slit to admit the small piece at the end of the spring 6. On
each side of this slit is an adjusting serew e e, the points of
which face each other, and are placed so as that the spring
may move equally between them from its point of rest. The
action of the spring between the adjusting screws requires
to be somewhat less than the angle of escapement. Let the
balance be made to vibrate, so that the straight spring may
move up to the adjusting screws upon each side, and no far-
ther; being weaker than the pendulum-spring, its exertion
will be less; hence the time of the vibrations will be pro-
longed, but as they increase, the exertion of the pendulum-
spring will commence and progressively accelerate them, and
this acceleration will always be in proportion as the exertion
of the pendulum-spring is to the action of the straight
spring between the two adjusting screws. Thus it will al-
ways counteract the accelerating effect of the escape-wheel
in the small arcs of vibration, so that the whole of them
shall be performed in the same time.

The third method is by connecting a piece of short springs
wire to the pendulum-spring by a small piece f, fig. 5 and
6, with two holes; pinning the two springs together about
half a turn from the stud of the pendulum-spring ; and
clamping the other end of the short spring at its natural
point of rest to a shding piece, g, which projects out from
the pendulum-spring stud. By this manner of fastening,
both springs will act together, and each will retain its na
tural point of rest; but by moving the sliding piece, which
clamps the end of the short spring, and placing the spring

a little

COMPENSATION PENDULUM. 53

a little on the strain, in opposition to each other’s éxertion,
the point of rest of both springs will be destroyed. Thus
by producing this counteracting force in the two springs at
the lowest point of vibration, the accelerating effect of the
escape wheel upon the ‘balance in the small arcs of vibra-
tion will be corrected, whereby the whole of them will vi-
brate in equal time.
a

Extract of a Letter from Captain William Brown, addressed
to Mr. John Nichols, Millpond-bridge, Bermondsey.

Respecting the chronometer which I purchased from Mr, Testimony of
William Hardy last year, the jolting of.the coach in the mP ee
conveyance to Liverpool altered its rate of going to 34’ ‘slow, Hardy’s chros
which rate it continued so exactly, that in making Cape de "°™**"
Verd, on the coast of Africa, (the longitude of which has
been correctly ascertained) in 24 days from, Liverpool, and
carefully measuring my distance from the Cape, I could not
discover it to have deviated from the rate, say 34” slow,
one second in the whole time; and I have every reason to
believe that it continued the same rate, until my misfortune,
when it got immerged in sea-water, having lost my ship on
a slioal five or six leagues from the Riatiaaiae this dange- Dangerous
ous bank not being laid down cotrectly, or the latitude or oe

longitude given in order to avoid it,

VII.

Description of a Compensation Pendulum for a Clock, or
Timepiece, with Experiments. By Mr. Henry Warp,

of Blandford, in Dorsetfhire*.
SIR,

Herewira I send you a new compensation-pendu- New compen-
lum, which I beg you will lay before the Society of Arts for } cy pe
their inspection. I trust their liberality will be equal to ce
advantages that may be seen to result from it, together with
their consideration of the pains I have bestowed in making

* Trans. of the Society of Arts, vol. XXV, P 116. The silyer medal

ef the Society was voted to Mr. Ward, :
at

54

Description of

it.

[ts action.

Smeaton’s ex-
pansion table
used,

COMPENSATION PENDULUM.

it. It has cost me much labour, time, and expense; ins
deed, it has occupied almost the whole of my attention for
the last nine months,

If any objections should be made to it, I will endeavour
to answer them, and make any further experiments re-
quired.

y Tam Sir,
Your obedient servant,

HENRY WARD.
EES eT ee

Ply (i, 2S. 7; a2 Gare two flat rods of iron or steel,
ahout half an inch wide, and an eighth of an inch thick.
kk is a vod of zine interposed between them, and is nearly
a quarter of an inch thick. The corners of the iron rods
are beyilled off, that they may meet with less resistance
from the air; and it likewise gives them a much lighter ap-
pearance. These three rods are kept toge:her by means of
three or four screws //7/, which pass through oblong holes
in the bars hA kk, and screw into the rod 77. The rod hh
is connected to the rod kk by the screw m, which I call the
adjusting screw. ‘This screw turns in the rod hh, passes
through the zine rod kk, and screws into the iron rod 73,
The rod iz has a shoulder at its upper end turned at right
angles, and, bears on the top of the zinc rod kk, and is sup-
ported by it. It is necessary;to have several holes for the
screw m, in order toadjust the compensation. See fig. 8.

Now it is evident, that if amy degree of heat or cold be
applied to this compound rod, the one of zinc expands and
contracts as much as the two iron ones together; the dis-
tance from the point of suspension to the centre of oscilla~
tion therefore must remain the same.

In ‘proportioning the length of the rods, I made use of
Mr. Smeaton’s table of expansion of metals, in the 48th
vol. of the Philosophical Transactions: where he shows, by
experiments made with a pyrometer, that the expansion of
iron is to that of unhammered zinc, with the same degree
of heat, as 151 to 353, and to that of zinc hammered half

an inch per foot, as 151 to 373. This great expanding pror
perty-

COMPENSATION PENDULUM. ae

perty of zinc renders it in theory extremely fit for the pur-
pose of compensation in a pendulum, and I was desirous of
knowing if it would answer in practice, and likewise the
exact proportion, that was requisite to answer the intended
purpose. |

I made two regulators, the sis Bane of which were Two regulators
composed of iron and zinc, as above described; with this Cea ae
difference, however, that one had a detached scapement of !
a particular construction; the zinc rod was not hammered,
the ball of a lenticular form, and weighed twenty pounds,
its are of vibration nearly five degrees. The other had a
simple remontoiring scapement, the zinc rod was hammered
half an inch per foot, the ball, of a spherical form, weighed
forty-six pounds, and vibrated two degrees and three quar-
ters.

These reculators were both need in the same room, and
their cases firmly fixed to the wall; the pendulums were
suspended from a stout brass cock, screwed to the back of “
their respective cases. In the inside of each case, and im-
mediately behind the pendulum rod, was hung a thermo-
meter, for the purpose of comparing the degrees of heat.
1 adjusted them to mean time nearly by corresponding alti-
tudes of the sun. After having compared them together Difference of
for several days, I found, that the one which had the ham- ie

ther greater
mered zinc rod went somewhat faster when the air of than Mr.

the room was heated by a fire in the grate than the other aaa 2 yea
did. Hence I concluded, that the difference of expan-

sion of hammered and unhammered zinc was greater

than Mr. Smeaton made it, at least it appeared so in this

instance.

But to determine whether the length of the hammered Contrivance
zine rod was accurately proportioned to that of the iron '" neeenee ve
ones, without being obliged to wait that length of time Cs zing
that nature would require to produce a sufficient alter- 4:
ation in the temperature of the air, I proceeded to make the
following experiment: I caused to be made a tin tube six
feet long, and two inches and a half diameter at its larger
end, from which it gradually tapered to the other, alicch
was only half an inch diameter. Within the case, and as
far from the pendulum as possible, I placed this tube; the

smaller

56 COMPENSATION PENDULUM.

smaller end was carried through a hole in the top of the
ease, and projected a few inches -ahove it. Yn the lower
end of the tube was inserted the nozzle of a lamp, and im-
mediately under it, in the bottom of the case, was a hole of
an inch diameter to supply the lainp with air. By this
meaus the tube would communicate as much heat to the
internal air, as to raise the thermometer about thirty-five
degrees.

Previous to the lamp being put into the case, I made beth.
pendulums vibrate exactly together, and after an interval
of twenty-four hours, the one with the hammered zinc rod.
had gained, as near as I could judge, one tenth of a second.
The mean height of the thermometer was fifty-three
degrees. J now lighted the lamp, and in about four hours
every part appeared to be thoroughly heated, and the ther-
mometer arrived at its maximum, which was eighty-eight
degrees; at this point it continued with little variation.

The motion While the heat was increasing I found the motion of the

acceleratede pendulum was ‘accelerated. I again made them beat ex-

“y actly together, and in about ten hours.after, the heated pen-

dulum had gained one second; the thermometer in the

other case continuing nearly the same. The lamp was then

taken out,‘and as soon as the parts were cooied, and. both

thermometers showed the same degree, I adjusted the beat

of the pendulums as before, and, at the end of twenty-four

hours, I found the’ pendulum ‘that had‘ been heated kept

precisely the same rate as it did bpiprd atte experiment was

made. edits) Reis ii 4

Thependulum “By this experiment the zine rod was evidently too nis

fan aS and that by a’ considerable quantity. Tbe pendulum was

then taken down, to have more holes made for the adjusting

screw, and after many repeated trials with the lamp and

tube, as before, I found the length of the zinc rod to be 22

Ratioofex- inches, and ‘consequently the length of -the iron ones toge-

pension Le ther 39°2 ++ 22 = 612 inches, or, the expansion and cons

tween iron and

hammered traction, of ivon-to ‘th at of zinc henimoret half an inch
zinc. per foot, as 151 to 420.° *”

When the air Having thus far satisfied myself with the hammered zine

was rarified the rod, | proceeded to make similar trials with, the one that:

eo epee was nahemmngre ;In doing which, circumstance. occurred,,

that,

\

COMPENSATION PENDULUM. 57

that I cannot account for; when the air in the case was rari~”
fied by means of the lamp and tube, the are of vibration
would be about half a degree less than it was before the.
Jamp was applied, which isdirectly contrary to what I should
expect would have taken place. Lafterwards found, that
the other pendulum was affected the same way, but in an’
extreme small degree, which, without doubt, was in conse-
quence of the ball being much heavier, and vibrating a
smaller arc. In taking the rate of the clock when the lamp
was in the case, I at first computed from theory the errour
that would arise by such a d-minution of the arc, and al-
lowed for it accordingly ; but doubting whether the unlock-
ing of the swing wheel might not form a decrease of velo-
city in the pendulum, and have a greater tendency to retard
its motion, I therefore thought the experiment would be
rendered more accurate, if the maintaining power was in-=
creased untilthe are of vibration should be the same. Af> yy, Snieatente
ter several trials, I found the length of the unhammered ratio between
zinc rod to be about twenty-nine inches, which agrees euseesp ON
pretty. nearly with Mr. Smeaton’s experiments; that is, in near the truth.
regard to the relative expansion of iron and unhammered
zinc.
-'The zinc rod of the pendulum, which I here send to the Farther ham.
Society of Arts, was hammered three quarters of an inch ™<Tivg the
zinc makes no
per foot; and by making experiments with it as I had done alteration,
with the other two, I fail the length of it to be twenty-
two inches, which is exactly the same length as the one that
was hammered half an inch per foot, so that it seems no-
thing is gained after hammering it to a certain degree; but
I cannot think, that any rule can be laid down to enable us Quantity of
to judge of the degree of expansion that will take place wrest oh
with a determinate increase of heat, from the quantity that se cig
is extended by the hammer; much depends on the degree
of curvature and polish of the stake and hammer, and pro-
~bably on the heating of the rod at the time; for it 1s neces-
sary to heat it a little hotter than boiling water, otherwise it
will crack in hammering.
In all these experiments it is to be wnderstood, that Ball suspended
the ball of the pendulum was suspended by its centre; by ils centres
pat if the ball be made to Test oa its lower edge, the

expansion

Supposed ob-
jection to zine
unfounded,

Pendulum at
first continually
retarded,

‘Tis common
to others,

Owing to the
effect of the
ballon the
point of con-
tact,

Advantages of
this pendulu: n.

COMPENSATION PENDULUM.

expansion and contraction of it must be taken into consi~
deration.

' Jt has been the opinion of some mechanists, that zinc is
an unfit substance for a compensation-pendulum, because
they have thought it too soft for the purpose, and that af-
ter bang heared or cooled to a considerable degree, it does
not return to its original dimensioas. If that was really
the-ease, no doubt but it would be a general one common
to all metals in a greater or less degree; but from the ex-
periments and observations I have made on zine pendulums,
I am fully satisfied there’ is no foundatiow whatever for
such an opinion. Some time in the latter part of last sum-
mer, | however noticed a circumstance, that made me doubt
the matter—for when J first used my zinc pendulum, I never
could bring the clock to keep the same rate two days toge-
ther, but it was continually retarded, whether I used the
lamp or not; and had I not before observed a similar effect
on a lever pendulum, that was made of brass and steel, I
should have ascribed the cause whotly to the softness of the
zinc rod; but by constantly comparmg its daily rate with
one that bad been going a longer time, I found this retard
ing property gradually wore Bit and in less than a month
would become quite settled to the rate that it would after-
wards keep. By subsequent experiments with the lamp too;
I have constantly found, that all the pendulums J have
hitherto tried kept precisely the same rate, both during the
time they were heated (provided they were properly ad-'
justed) and afterwards, as they had done before. The cause |
of this retardation appears to me to be, that the points of ©
contact of the different pieces, which compose the pendu-
lum, are more closely connected after a little time; than they
are at first; that is, those points of contact do, by the weight
of the ball, yield to each other m a small degree, until
they get a broader bearing.

The advantages of this pendulum are, Ist, that Solas its
simplicity it will never fail to have the desired effect. adly,
_ That no extraordmary care is requisite m executing: it.
’ 3dly, That the compensation may beincreased or didttiniclhed
with the’greatest ease, without stopping the clock more than

@ minute, by makinov fast one ofthe screWs-that keep the

rods

7:

COMPENSATION PENDULUM. A 59

ftods together while the adjusting screw is removing, taking
"care to release it again afterwards; and 4thly, That it can

be manufactared for less expense than any other compen-
- sation pendulum hitherto published.

N. B. The compensation of this pendulum which I now -
send to the Society of Arts is proverly adjusted, at least
very vear the truth. The holes for the adjusting screw are
made at such a distance from each other, that by removing
thescrew one hole, it will produce an-alteration in the go-
ing of the clock of about a quarter of -a second per day
with a change of tairty degrees of Fahrenheit’s thermome-
‘ter.’

a

“SIR,

PERMIT me to state to you the observations I, have
made since my compensation-pendulum was laid before the
Society.

The regulator, with the hammered zine rod, and ball A Pendulum with
forty-six pounds weight, was firmly fixed to a brick wall at ldots
the top of my house. The adjustment of the length of extremity.
the rods, by means of a lamp, was repeated as before.

There was, however, an alteration necessary to be*noticed$

the ball of the pendulum rested on its lower extremity, in-

stead of being suspended by its centre. I prefer this wethod,

as being less hable to errour, if the rods should be affected

by heat or cold. quicker than the ball. The length of the Length of zinge
_ zine rod, as ascertained by the lamp, was now found to be

Bo. inches.

_ The clock was then set to mean time, and suffered to

go without alteration; the result is exhibited in the foNow-
“ing table. :

ae

Pirane of Clock rat

Number of Days

a 18 time of observation. | between the Ob- Daily rate. Hate, of Beings

806 servations, ¢
March 21 0” oO 18 Sob Oo 15
April 8 + 2 8 32 | +o. 18
May 10 + 8° 7 16 + 0°> 80
20 + 21° 5 26 + 1: 10
June 21 | a)

th 50°

«Wy
”

-~

Increased

60

Length of zine
increased,

Rate of goings

| Proper length
of zinc,

COMPENSATION PENDULUM.

Increased the compensation for heat and cold, 6 holes
= 43 inches, or, the length of the zinc rod to 25 inches. The
clock was again set to mean time.

Q”

July 1 0|26/[—0” 36
27|— 9° 3/13|—O° 21
Aug. 9|— 12° O| 7|/—0O 381
16}—14* 2/28]/—o- 34
Sep. 13 | — 24 0/12]—0* 60
25|—35° 5|22/—0° 84
Oct. 17 | — 52° 1

Although a thermometer was attached to the clock, I
could not from a necessary atteudance to business register
it regularly; the difference of its height in March and June
may be taken at about 22 degrees, and in July and Octos
ber 14, without much errour.

On comparing it with the rate of the clock, the compensa-
tion, in the latter case, appears nearly as much too great,
as it was in the first too small. The true length of the
zinc rod ought to be about 23 inches.

The length of the zinc rod, thus ascertained, is 13 inch
more than the experiment by the lamp makes it; indeed, I
have always suspected there might be some errour in that
experiment, on account of the length of the arc of vibration
being affected by it. :

Having no means of finding the time accurately but by
equal altitudes, I could not get so many observations as
might be wished. I trust, however, these will not be found
altogether useless.

T am Sir,
Your obedient servant,

HENRY WARD.

1X.

AIRTIGHT HINGE. ; 61

IX.

Account of a new airtight Hinge for a folding Screen, or for
a Door; by Mr. Martin Furniss, No. 128, Strand*.

SIR,

Tue model I have herewith sent is my invention. I beg Joint for a

: : folding screen,
leave to lay it before the Society for the encouragement of 9; door, ww ex.
Arts, Manufactures, and Commerce, in the hope, that they clude air.
will be pleased to examine it, and find it worthy of some
mark of their approbation. It is a model for putting to-
gether the joints of a folding screen, so as to fold in
_ either direction without admitting the smallest quantity
of air; it may likewise be appropriated to hanging of
doors.
mae “ I am, Sir

Your humble servant,

M. FURNISS.

A Certificate from Messrs. Wilsons, cabinet-makers in Has been tried.
the Strand, testified, that Mr. Furniss’s model for screens or
doors is his own entire invention, and has been executed by
them on a high folding screen for a lady in Baker street,

Portman square.

Reference to the Engraving of Mr. Furniss’s Airtight Hinge |

Sor a Door or Screen.

Pi. Ii, fig. 9. A plan of the joint: A B, two sides of the Description of
Screen with circular ends, joined by a piece of leather sek se
reaching from top to bottom fastened at C, and wrapping
(like the letter S) partly round the curve of one fold of the
screen, and partly round the other to D, where it is also

* Trans. of the Society of Arts, vol. XXV, p.126. Ten guineas
were yoted to Mr, Furniss for thie invention.
. fastened :

63

AIRTIGHT, HINGE,

fastened: EF, a chain formed of brass plates tivetted te-
gether, winding round in a groove from off one fold of the
screen on to the other,the contrary; way to the leather, so as
mutually to keep each other stretched tight, the chain
winding on when the leather winds off, and vice versa;
thus they move smoothly round one another. G, fig. 10,
a piece of brass (left out in the last figure in order to

show the chain) screwed to the centre of each curve of |

the screens which forms the hinge, and by keeping’ the
folds of the sereen at their proper distance secures the
easy actiou of the chains and leather, and prevents their be-
ing overstretecned. HH, a line of green twist fastened
along the bottom of the screen, and passing through a sta-

-ple on the joint at G, serving to keep the screen inated on _

the floor.
Fig. 11 1s an elevation showing the top ae bottom jolt,
with the same letters of reference.

REMARK.

'

It would frequently be a desirable convenience to have
the doors in the interior parts of a house so contrived, as-to
open either mwardly or outwardly. Mr. Furniss’s hinge.
would effectually answer this purpose: but it would be pro-
per to have the opposite edge of the door padded, as it
could not be made to fit ee and there must be~no ledge
for it to abut against. A piece of leather nailed on it, and
then stuffed with wool. or horse-hair, might be so adapted,
as to make this side airtight also, at the same time that it
would open and shut freely. It is probable however, that
some inconvenience might be felt in applying Mr. Fur-
niss’s hinge to a door, particularly if lavge and_ thick,

from the strain upon it by the weight occasioning it to

drag. The best remedy for this would be a couple of

castors in the foot of the door, one near each end. Ca

+.

» io" , @ jo

|
|

+e, Wed

Nicholson’ Phalas. Journal, Vo t.HL, PLL. p62,

Dp» “Gil: Maciel Coeedan G5 Modine ;

ae I

ae TM

Wii a
aun
al

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i Lia laa i =»

| WHIVHNMA

HHAMMGMUPRANETECLCAU TEESE NAT
ail HVUFANEESURANGRE enn i
nia :

Sa i

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Hi
Hi

Hi

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Problem by. J. bough Esq?
R

HAT

= ‘i "| | ‘ : »

EXHAUSTING MACHINEs 63

DF

Description of an exhausting Machine on the Principle of
the Torricellian Vacwum : by Dr. Tuomas STEWART
a !

Se time ago I was engaged in a series of pneumatic Chief defect of
experiments with the air pump, which led me to consider cone oe
of the best means of obtaining a vacuum. The chief im- imperfect.
perfection of an air pump consists in its not being capable

of affording a perfect vacuum. Each stroke of the piston
removes a portion of air in the receiver; but the remaining

air expands, until it occupies the same volume which the

whole of the included air did. The next stroke abstracts

an equal volume of air with the former, but as it is mow -

_-less dense, the real quantity is smaller; and hence every
succeeding stroke removes a less quantity of air than the
preceding. The exhaustion goes on, till the elasticity of

what remains in the receiver is no Jonger able. to open the

valves of the machine, when it has ronda the utmost li-

mit. But even if the machine was constructed in the most

perfect manner possible, it would evidently be impossible

to obtain a complete vacuum on the principle of the air

: pump: for its effect is expressed by a fraction, the value of

which, though constantly increasing, never amounts to

unity: 2. e. aged continually approaching to, it never can

afford a complete vacuum.

Impressed with these objections to the air pump, it oceur- Attempts to
red to me, that, if there was a convenient method of using ae the Tor-
the Torricellian vacuum, it would be preferable to the com- aa a
mon air pump, even when best constructed. After various
attempts, the annexed figure and description will give an
idea of the machine, which I conceive well adapted to answer
the end proposed.

The object in this machine is to procure a vacuum in the Apparatus an
receiver D, by means of mercury, with which the receiver this purpose
is previously filled. A (PI. J, fig. 1) is a circular plate of ou
thick glass, firmly unbedded in the wooden frame C, which

: is

64

Method of us-
ang the ma-

shine.

EXHAUSTING MACHINE.

is supported by the wooden pillars H. The surface of the
plate is to be ground perfectly flat. B is an iron tube, ce-
mented at its upper extremity in a hole dnilled in the plate
A, and having its lower-extremity terminated at the bottom
of the wooden tub E, by a stop cock, which is opened and
shut by the wire F. The length of the tube ought to be
about three feet; its diameter about the size of a common
barometer tube. The receiver is to be ground in the usual
manner to the plate, and to be fitted with an air-tight cover,
I, ground to its upper orifice. K_ jis a stop cock, through
which the external air may be admitted when required. A
slight depression ought to be made in the glass plate about
one inch around G, that the mercury may more readily de-
scend through the tube. The iron tube ought to reach
through the glass plate to the bottom of the slight depres-
sion ; and its inside at the top ts to be furnished witha fe-
male screw, by which the transferrer, or any other appara-
tus to be used within the receiver, may be fixed to the
plate. It is hardly necessary to observe, that the piece of

iron which screws into the upper end of the tube B must

be so perforatéd, as to permit the easy descent of the mer-
cury. The inside of the tub E ought to be coated with
strong varnish, to prevent the loss of mercury through its
joinings, and may have a cover so fitted to it, as to keep
out dust, though not to exclude air. The lower extremity
of the tube B ought for steadiness to be fixed to the bot-
tom of the tub, by a flanch and screws. The edges of C
ought to project about two inches above the glass plate, that
any mercury which falls over may not be lost.

The transferrer, fig. 2, is made like the plate A, and
frame C, fig. 1. The lower rim of uw is intended to rest
upon the edges of C; when the iron screw 6 is fixed in G.
The key of the stop-cock, d, passes through the lower rim,
as in the figure.

To use the exhausting machine, draw off the mercury
which is in the tub E, by the stop-cock L, leaving just as
much as will cover the extremity of the iron tube. Shut
the stop-cock at M, pour in mercury at G to fill the tube,
anoint the glass plate with hog’s lard, place on the receiver,
fill the receiver likewise with mercury, and then place its

cover

EXHAUSTING MACHINE. 65

- gover I on it. On ope eniag M,. the mer cury will descend

by the tube, and leave the receiver exhausted. By shutting

the cock N, the vacuum is rendered more secure.

_A small degree of contrivance will adapt this apparatus Contrivances

to every experiment, which can be performed with the com- pen eho

mon air pump. If we wish to experiment on fluids, they riments, as om
- may be enclosed in a flask of the form of fig. 8. The screw "vids

‘at its bottom must be perforated so as to permit the descent

of the mercury when it is fixed in G. A ground stopper of

glass, e, is to be placed 1 in the neck of the flask, c, after it is

filled with the liquid to be subjected to experiment: the flask

is to be screwed to the plate A, and when the receiver is

exhausted, the stopper is to be withdrawn by the sliding

wire, fig. 4, which with its ground plate is to be substituted

for I. The length of i stopper of the flask will afford

room for the expansion of the liquid.

_ When we wish to exhibit the pressure of the atmosphere Bi geal
by means of the apparatus, fig. 5, fill both jars, and exhaust ae
them; force down the flat button, which is screwed on the end “"°"™
of the sliding wire, till it covers the orifice of the small jar,

_and then let the atmospheric air into the outer receiver, by
the cock K. The small receiver wiil adhere to the plate.

By similar slight changes in the other usual apparatus of
‘an air pump, they may be adapted to the exhausting ma-
chine.

The advantages of an apparatus, such as I have now de- Advantages of
scribed, over the air ‘pump, seem to me - considerable cae ER
consequence.

_1. The vacuum will be much more perfect; being only
affected by the small quantity of air adhering to the mere
cury, or by the conversion of the mercury into vapour,
which is as much as possible obviated by the cock N. -

2. There will be a great saving of manual labour.

3. Exhaustion will be more quickly performed than by
the common pump.

4, It is more simple than the pom, and less liable to be
deranged.

5. The expense of this machine will not exceed, I appre- Not expensive:

hend, that of one of the best air pumps, while it exhausts,
“more perfectly. Where nice chemical experiments are con-
“Vou. XXI—Sepr. 1808. F ducted,

66

Trial of one
rudely exe-
cuted.

Materials,

ON DE MOIVRE’S DOCTRINES OF CHANCE.

ducted, a large supply of mercury is indispensable, for there
is scarcely a gas, which is not more or less absorbable by’
water. The mercury of the exhausting engine will answer
for the mercurial trough in the laboratory, and thus a con~
siderable portion of the expense of the machine ought to
be deducted..

In some experiments I made with a rude miele of the
kind I have described, I found, by anointing the plate and
edge of the receiver with hog's lard, that I could raise a
column of two feet in height in a receiver open at top, and
even could move it along on the surface of the ground plate,
without any mercury running out between the plate and re-
ceiver. .In fitting on the top of the receiver, it may how-
ever be proper to press gently with the hand on the receiver,
till the atmospheric pressure begins to act on if.

N.B. The whole machine, and its auxiliary apparatus,
must be made of glass, wood, and iron or steel, on which
mercury does not act. .

THO. STEWART TRAILL.
Liverpool, May 12, 1808. :

——
Annotation, in Reply to the Doctor's private Letter.

Though mercury has been used for exhaustion by: Dr.
Clare, and Sir A. N. Edelcrantz, in air pumps described
in our Journal, and by others, I have thought Dr. Traill’s»
contrivance sufficiently original, and different from former
apparatus, to be inserted.

W. N.

XI.

Doubts respecting some of the received Doctrines of Chance.
In a Letter from a Correspondent.

To Mr. NICHOLSON.
SIR, Durham, August 9, 1808.

Some received Rifle the following scruples as to the truth of the

doctrines of

elementary ieee of chance hop admitted appear

er

ON DE MOIVRE’S DOCTRINES OF CHANCE. 67

- worthy of a place in your valuable publication, their insér- chance ques-
~ tion will, I hope, elicit from yourself, or some one of your ° “ses
mathematical readers, a few words in reply, to convince or’

to confute a mind on all occasions suspicious of its own de-:

ductions, whenever these deviate from the opinions of others,

old and learned in their walks of science.

The celebrated de Moivre, in his work, Case the first,

assumes the die as a familiar and favourable subject for de-

monstration: let us follow him in sense, though without

the advantage of his identical words, as I have not a copy

at hand.

** Any one undertaking, with a die of 6 sides, to cast an Chance of a
throw with a
ace in one throw, has 4 of the 6 possible chances in his fa- single die.

your, and the Deesian 2 against him; the whole 6

chances being certainty, or at least such i the event of

continued trials.” Granted— |

** Any one undertaking to cast an ace in two throws Chance of two —
of one die, bas for the first probability 1, as proved: threes
should the first fail, then the second eros biy which is
likewise; but the chance of the first failing is $, as that oy

its succeeding is 1; therefore the second ree is only 4 of 2d chance 1

4 for its chance of success, which added to the chance of !s an 2.
casting an ace the first throw, is +++ +o0f S=1+4¥=—4%
+ #5 = 44; the first throw being .9;, the second only 3%.”

This doctrine. cannot grant. Nothing can prevent him Butall the
of the second throw, éxcept his succeeding in the first; beta ey
therefore, either he has no occasion for it, or he has it in all whole.

its full force and virtue of + chance, from which no circum-

stance can deduct. Bubnnise it must be denied, that two

equal chances are twice as good as one; and by summing

up, according to de Moivre’s rules, the probability of casting

an ace in six throws of one die, it will of course be found,
that they are velow &, to which they should of course
amount, being the assumed sum of certainty on the event,
pon an average of trials.

The chance of throwing a head with a halfpenny in two Instance inthe
throws, according to de Mivivic, | is, for the first, 2; forthe Seay. ane
second, only $ of 4: so that the one is twice as good as the

_ other, and together they are 4 short in probability of what~

Was assuined certainty, or ii amount of all chances,

Fr 2 Any

68. ON THE DISCOVERY OF METALS IN THE ALKALIS. |

Any of your correspondents, ‘or yourself, being kind
enough to explain de Moivre to conviction, or my opinion
to Cuntintiliae will, wis I pursue but the truth, equally
oblige, Sir,
Your constant reader, \

and most obedient servant,
OPSIMATH.

» Oe

Letter from a Correspondent on the late Discovery a Metals
im the fixed Alkalis.
SIR,

Assertion of Y our last reminds me of some notes I took at Oxford,
DES ae on attending Dr. Beddoes’s lectures in 1788, wherein he
and alkalis said, that vital air was a part of the alkalis and earths. At
en oxi the same lectures, the strongest electricity was advised, for
wr giving shocks to molten phosphorus, &c. Some years ago,
at a friend’s, I saw a beok with essays by several hands—
Dr. Beddoes and Mr. Davy among others. It is called
Their metallic Contributions, &e. I think ;—be that as it may, a query is
a conjec- started, whether the earths and alkalis hold not oxigen,
and that they may come to class with metals. It is. always
curious to know who has guessed best. If you have the
above book, you may find reasons for opimions then aes
strange, and farther particulars.

A. DILETTANTE,
8th Aug. 1808.

¢

Ee
S REMARK.

Metals long The notion of alkalis being \oxigenated metals capable
ago supposed of being reduced, is much older than the book in question.
ave Di agi The experiments of von Ruprecht and Tondi at Schemnitz,
with the discussions which arose from them among some of

the most eminent chemists, ‘not only in Germany, but in

Italy and France, are fresh in remembrance. It is certain,

that metals more or less resewbling iron, or phosphuret of

iron, were produced, in appearance from barytes, lime, mag-

nesia,

ON THE DECOMPOSITION OF THE ALKALIS. 69

“nesia, and dorax; and though this was at length supposed

to be refuted, as similar grains of metal were obtained

without either of these, yet I believe in this case an alkali an alkali es
was always present.. It must be confessed however, the ies 4
metal produced by the German chemists was extremely dif-

ferent from either of the metallic bases of the alkalis lately

discovered by Mr. Davy.

XIII.

On the Decomposition of the Alkalis. In a Letter from
Mr. Wititam Cooke.

To Mr. NICHOLSON.
SIR, Wolverhampton, 10th July, 1808.

Iw your excellent Journal for January last, under the

head Scientific News, is announced the decomposition of Decomposition
the alkalis, by that eminent chemist, Professor Davy ; of the et
whose very name almost deters one from entertaining a con- histones
trary idea: but the conclusions drawn by him do not appear

to me to arise from the facts adduced. Since that time I

have turned over your Journal, and other publications, in

hopes that some one with more leisure and abilities would

have pointed out, not the want of accuracy in his experi+

ments, but of clearness in the conclusions drawn therefrom;

but not seeing any thing of this kind, I have determined

to devote a few minutes from business to offer the following :

and if it appear worthy of your notice, it is much at your

service, from,

Sir, ™
Your most obedient servant,

, WILLIAM coke

In Volume XIX, page 78, of your Fide ids it appears, Moistened al-
kali placed in
that Mr. Davy made moistened potash, soda, &c. part of a; aldiiee etc:
galvanic circle, in which situation oxigen gas was evolved, and cle.

> ~ a substance

70 ON THE DECOMPOSITION OF THE ALKALIS.

a sifbstance of a metallic appearance remained, which was
denominated the base of potash, &c., and possessed, among
Proverties of others, the following properties. If a globule were thrown
oe ae into water, or upon ice, a bright flame and great heat were
produced, hidrogen gas was evolved, and the alkali found
in solution; if upon moist turmeric paper, the same phe-
nomena appeared, with the acquirement of a rapid motion,
and its course marked with a red or brown stain, proving
the reproduction of the alkali. In all which instances it is
stated, that this metallic body has such an affinity for oxi-
gen, that it instantly decomposes water, absorbing its oxi-
gen (which regenerates alkali) and its hidrogen of course is
Alkali regene- set at liberty. But, if the experiments with metals be faith-
sae de fully reported, alkalis are regenerated from these supposed
oxigen. bases, either by losing or re oxigen.
Matter ofelec- It seems reasonable to conclude, that the matter of pes
py Pah etn tricity is as capable of combining chemically with bodies,
tion. as the matter of heat or light is; and that Mr. Davy has
found the means of uniting another af the simple combusti-
bles with the alkalis.

Sulphuric acid - Perhaps to say concentrated sulphuric acid is a calorated
are nee of oxigat of sulphur may appear barbarous; yet it is impossi-
ble to form it without the union of caloric, or to dilute it
without the loss thereof: therefore, as I cannot find a more
New bodies, expressive name for these new bodies, I will call them elec-
shes) come trated hidrats of potash, soda, &c.; wherein the hidrogen
electricity. has so weak an affinity for the alkalis, that solution decom-
poses them; for on coming into contact with water, they
are so rapidly decomposed, that the matter of electricity
becomes visible, the hidrogen takes the gaseous form, and

of course the alkali remains in solution.
In chemical The importance of accounting for the whole of the sim-
era: ples submitted to chemical experiment cannot be too often
ent pars | enfurced; and that experiments may be depended upon, it
should be ac- js absolutely necessary. © The ovéflooking of this seems to
eye a me the only cause of Mr, Davy’s miftake: for, as the alka-
lis were morstened, and it is the known property of the
galvanic fluid to decompose water, and as one of its com-~
ponent parts was evolved, it was absolutely necessary to
inquire saith the other; more especially, as the body pro=
duced

QUANTITY OF FECULA IN THE POTATO. 71

duced was found to be incompatible with the presence of
water,

_ Thus, if the above arguments be conclusive (but, from
my time being necessarily deveted to business, I have not
opportunity of submitting them to the rigorous test of ex~
periment, as they deserve, or as I could wish), it appears,
that these new substances, instead of being the bases of ale
kalis, are compounds of aliali and hidrogen united by means

of the electric fluid.

—— ee ane aera

ba XIY.

On the Quantity of Fecula in different Varieties of the Po-
tato. By Mr. WiL1iamM SkRimsuire, Jun.

- SIR, Wisbech, Aug. 12, 1808:

Ir the following paper, on the quantity of feeula in the

different varieties of the solanum tuberosum, which was lately

read before a small society of philosophical amateurs in this Philosophical .
town, be deemed worthy a place in your valuable miscellany, caine at Wise
I shall be glad to have it inserted: and shall soon follow ~”

this up by a second communication, on the quantity of fe-

eula procured from some other vegetables of British growth, “

and the economical purposes, to which they may be aps

' plied.

I remain, yours, &c.

W. SKRIMSHIRE, Jun.

In the early part of the present summer I undertook 4 Quantity of fe-
series of experiments, to ascertain the quantity of fecula eve Uihjcy pox
contained in the several varieties of the potato cultivated i in ™ puept
this neighbourhood, which I take the liberty of laying he-
fore the society, for their information, and as a subject well
worthy of a farther investigation.

But as the following experiments were tnade with the Experiment
+ fresh roots, and at a time of the year when most of them sen ig

were in a growing state, the several results gan be viewed
merely

72

Cautions.

Fecula most

abundant in au- -

tumn, partly
changing to
saccharine mat-
ver in spring,

Potato atéracts
moisture from
the atmosphere.

Fecula dried
in a roaster.

Skin of the po-
tato included.

Dr. Pearson’ 5
experiments
with the kid-
mey potato,

QUANTITY OF FECULA IN THE POTATO.

meres approximations toward the truth, or at most, ag
showing’ the relative quantity of fecula, afforded by the dif-
ferent.) varieties which were operated upon,

When experiments are made in the large way, with the

fresh potato, the different degrees of moisture, which the
roots may possess, will materially influence the results ; so
will the form of the grater, and the force which is employed
in grating them. Therefore when great accuracy is required,
the potatoes should be sliced, dried, and ground to meal,
before being subjected to experiment.
Perhaps the greatest quantity of fecula may be procured
in the autumn, as soon as the potatoes are dug up 5 for
those that have been preserved through the winter are so
disposed to vegetate in the spring, that they then contain
more of the saccharine matter than they do in the autumn:
and this is produced at the expense of the fecula, for it is
probable, that, as the fecula absorbs oxigen and hidrogen,
it parts-with a portion of its carbon, and is thereby converted
into sugar.

Another circumstance, which may very much affect the
apparent quantity of fecula, is its precise state of dryness
when weighed; for it quickly attracts moisture from the at-
mosphere, and therefore should always be weighed at a cer-
tain temperature, in a dry room.

In the following experiments, the fecula, after being dried
iu the open air, was placed for some hours in a Rumford
roaster, moderately warm, and weighed as soon as it was
taken out. This perhaps is one reason why my produce is
generally below that of Dr. Pearson, which he communi-
cated to the Board of Agriculture, as well as by his not
using the skin of the potatoes in his experiments, as I did
in those which follow.

From Dr. Pearson’s account we learn, that 3500 grains
of fresh potato root, commonly called the white kidney,
being dried, leave 1000 grains :

That 100 parts of the fresh root, deprived of skin, afford

A Waterserseneses 68 to 72
2s Meal eeoerewmoeasn 32 to 28

tenes

109 100

The

QUANTITY OF FECULA IN THE POTATO, | 73

The meal consists of three substances,
1. Starch or fecula e-+sr+eeneee+s 17 to 15
2. Fibrous matter -++-eeseeeseeese Qto 8
3. Extract or soluble mucilage ---- Gto 5—

32 °+28

Thus 100 parts of fresh root afford from 15 to 17 of fine
dry fecula*.

The following are the results of my experiments made Method in

x ‘ r which Mr.
with five pounds of each variety of the potato, weighed af= Skrimshire’s

ter being washed clean, brushed with a hard brush, and ©*Pcriments
: : ft were mades

wiped dry with aclean linen cloth. The root was afterward

grated in cold water. The whole of the pulp‘and water

was placed in a fine hair sieve to drain, and fresh water

poured over it, stirring up and squeezing it with the hand,

until the water passed through perfectly clear.
By this operation a/most the whole of the fecula or starch

is washed from the fibrous matter, and falls to the bottom

of the vessel in the form of a firm white precipitate. This

-precipitate was again edulcorated with water, and passed

through a fine silk sieve, which separated it still more from

the finer particles of the pulp. The fecula was then al-..

lowed to settle, and being collected was dried by a free exe,

posure to the air, on a clean linen cloth.

1. Captain Hart.

. This is a roundish white potato, with a thin smooth skin, Potato called
of a moderate size; and with but few eyes. When boiled eee
and peeled it appears ofa yellow colour; its consistence is
‘rather close and watery, but it 1s tolerably well flavoured.
A peck weighs from 14 to 15 1b. - ; '

Five pounds weight afford,

Ib. oz. \
Fine fecula very white:-++++eeserees 1 Q
Fecula slightly discoloured....+++++s 3
Pulp dried ---eee sce crececnenevcces 6
} Water, soluble mucilage, and extractive
Matter-coecsesecceereceonseccevere 3 14
5 0

* Repert, Arts, &c, vol. II, p. 382, ; >
2 Rough

74 * QUANTITY OF FECULA‘IN THE POLATO.

2, Rough Red.

Rough red. This is a round red potato, of a moderate size, with a
thin skin, rough with minute fissures and scales. When
boiled it is very mealy, but has rather a strong flavour.

A peck weighs from 13 to 14 lbs.
Five pounds weight afford,

: . Ib. oz, e
Fine Whit teculaice.s oss 0.0 sks mobi bata ris
Fecula discoloured «+ -++seeesessees 32

Pulp GUYS ealaleie)s evetel ei ath calle tet eieioae ; of
Water, soluble mucilage, and extractive
Matterecceervecscccesssescesesoe GO LF

et

o 0

iu

3. White Kidney.

White kidney. This is a clean white potato, of a tolerable size, variously
shaped, generally flattened, and often with an indentation
on one edge, giving it some resemblance to a kidney jn its
form. The skin is rather thick; when boiled it is not very _
mealy, but pleasant flavoured, and a very good potato for
the table.

A peck weighs from 14 to 15 lbs.
Five pounds weight afford,

Tb. oz.
Fecula, the whole of which was of an
indifferent colour®:. “si. vs oe atc pice 93
Pulp dried slightly brownt --+-+--+++ 33

Water, soluble mucilage, and extractive
Mattere cer vcevercccecscccesccsecs A 22

5 0

4. Moulton: White. |
Moulton This is an irregular shaped white potato, of a tolerable
white. size. Itis sometimes flattened like ‘the kidney; and in-

* This I attribute to the potatoes being much grown.

+ The roaster beirg too hot, when the pulp was put in, it was rather

scorched.
; deed

QUANTITY OF FECULA IN THE sali 75

deed its general appearance bears a striking resemblance to
the white kidney potato. Its skin is rather thick. When
boiled it is very mealy, and remarkably well tasted. It is
by far the best potato for the table.

A peck weighs about 16 lbs,
Five pounds weight afford,

Ib. oz.
Fine fecula very white+++++++esseee- 9
Fecula slightly discoloured ++--++..+- Qg
Pulp dried -++sseeeeeeteeceees aie mies 5%

Water, soluble mucilage, and extractive
MBLC RE seve eake\s we etleivia\ slaieiic ceteteie bleje oe 3 144

5 0
5. Yorkshire Kidney.

This is nothing ike the kidney potato, and I think was Yorkshire kid-
misnamed. -It is-a thin, long, white root, with several Dey.
eyes, is very scabby, and has a thick skin. When boiled it
is slightly mealy, but has a strong taste.

A peck weighs from 14 to 15 lbs.

Five pounds weight afford,

Ib, oz.
Fine fecula very white ----- tee ceeeee 83
Fecula slightly discoloured --+-+++e+e 2h
Pulp dried ---..- Ay Plait Meglt A AE

Water, soluble mucilage, and extractive
Matters oc evcccccccsesccssaccsesce 3 145

eee

5 0

6. Hundred Eyes.

This is a long white potato of a midling size. It has nue prided ea
merous eyes, with a narrow transverse depression below each
eye. When boiled it has nd unpleasant taste, but is rather
too close in its consistence to be reckoned a good potato for
the table. 7

A peck weighs from 14 to 15 lbs.
Five

76 QUANTITY. OF .FECULA IN .THE POTATO,

a

j
. Five pounds weight afford,

OF TEE Ib. oz.
Fine white fecula -+-+eeereceesececs 8h
‘PDiscolouredfecula-- eeeeseeeceeseece ee 2
Pulp dried --eeeececceeecepeecccees 63.

Water, soluble mucilage, and extractive
Matters cceccasnces viawsaccoceeneees 4 O+

| ee

5 ®

7. Poor Man’s Profit, or Purple Red.

step This is a large round purple potato, with a thin skin.
b)

ple red, When: boiled itis hard and close, but has no very unplea-
sant taste.

A peck weighs from 15 to 16 lbs.

Five pounds weight afford,

; : } Ib. oz.
' Fine fecula very white «+ sseeeeseeecee 8

4 Very brown fecula+++eeeseserseseeee 4
Pulp dricde+sececrcvccscnccccccces x

Water, soluble mucilage, and extractive
WIATECT oc cc 60.0 whele wicle es «se wm old alslpre 4 Qt
oO
8. Ox Noble.
Oxnoble,

This is a very large, round, white potato; but when it
grows extremely large, it is frequently found hollow. It is
principally used for feeding cattle. When boiled it is close
and watery, with a very strong taste.

If perfectly sound, a peck usually weighs from 15-to 16
Ibs.

Five pounds weight afford,

1 Ib. oz
Fine white fecula eeoceoreocevnesseanevee 4
Fecula slightly discoloured ---++++++- 3 J

Pulp dried ----seeeevecccccccsevces 8
~ Water, soluble mucilage, and extractive
MAttererrersereesesrsecrercoscces 3 153

x VY.

PHENOMENON AT BUSSORA. rid

XY.

Account of a Phenomenon, that occurred at Bussora. From
Travels in Asia and Africa, by the late Avrawam Par-

sons, Esq., Consul and Factor-Marine at Scanderoon.
ome ig ae

‘

Marcr the 15th, 1775. At four this afternoon, the Sudden dark.
sun then shining bright, a total darkness commenced in an Ness
instant, when a dreadful consternation seized every person

in the city of Bussora, the people running backward and

forward in the streets, tumbling over one another, quite dis-

tracted, while those in the houses ran out in amazement,

doubting whether it were an eclipse, or the end of the world.

Soon after the black cioud which had caused this total dark

ness, avproached near the city, preceded by as loud-a noise

as I ever heard in the greatest storm. ‘This was succeeded attended with
by such a vioient whirlwind, mixed with dust, that no maa a violent whirl
in the streets could stand upon his legs; happy were those Wind mixed
who could find, or had already obtained, shelter, while those VW! dust.
who were not so fortunate were obliged to throw themselves

down on the spot, where they ran great risk of being suffo-

cated, as the wind lafted full tweaty minutes, and the total

darkness half an hour. The dust was so subtile, and the

hurricane so furious, that every room in the British factory

was covered with it, notwithstanding we had the precaution

to shut the doors and windows on the first appearance of the

darkness, and to light candles. 4

At half past five the cloud had passed the city, the sun,

instantly shone out, no wind was to be heard, nor dust felt,

but all. was quite serene and calm again; when all vf\us in

the factory went on the terrace, and observed the cloud had

entirely passed over the river, and was then in. Persia,

where it seemed to cover fuil thirty miles in breadth on the The cloud 39
land, but how far in length could not be even guessed at ; miles broad, &
it flew along at an amazing rate, yet was half an hour in half anhourin
passing over the city. It came from the north-west, and Pa5s!%é
went straight forward to the south-east.

The officers of the company’s cruizers came on shore as

‘soon as the cloud had passed their ships, and declared that

the wind was so violent, and the dust so penetrating, that

no man could stand upon the decks; and that after it was

ever, every place below on board the ship was covered with

dust. Such a phenomenon never was known before, in the

memory of the oldest man now living at Bussora,

SCIENTIFIC

78

SCIENTIFIC NEWS.

SCIENTIFIC NEWS.
St. Thomas's and Guy’s Hospitals.

Medical and I HE autumnal Course of Lectures at these adjoining

surgical lec-
tures,

Chemical and
mineralogical
lectures,

w

Hospitals will commence the beginning of October: viz.
At St. Thomas's.

Anatomy and the Operations of Surgery, by Mr. Cute .
and Mr. Cooper.
Principles and Practice of Sareery, by Mr. Cooper. -

At Guy’s.

Practice of Medicine, by Dr. BABINGToN and Dr.
Curry.

Chemistry, by Dr. placerat: Dr. Marcet, and Mr.
ALLEN.

Experimental Philosophy, by Mr.-AtLen. )

Theory of Medicine, and Materia Medica, by Dr. Curry
and Dr. CHoLMELEY.

Midwifery, and Diseases of Women and Children, by
Dr. Harenton.

Physiology, or Laws of the Animal GZconomy, by Dr.
HAitGHTon.

Occasional Clinical Lectures on select Medical Cases, by ©
Dr. Basineton, Dr. Curry, and Dr. Marcet.

Structure and Diseases of the Teeth, by Mr. Fox.

N. B. These several lectures are so arranged, that no two
of them interfere in the hours of attendance; and the whole
is calculated to form a complete course of Medical and
Chirurgical instructions.

London Hospital.

On Monday, the 3d of October, Dr. Buxton commences
a course of Lectures on the Uheory and Practice of Medi-
cine, and one on Materia Medica.

Ee

Mr. ACCU M’s Lectures on Experimental Chemistry whe
Analytical Mineralogy, commence at the Chemical Labo-
ratory, Compton Street, Soho, October the 18th.

The Lectures on Experimental Chemistry comprise the
Practical Operations of the Scientitic Laboratory, General
Rules to be observed in the performance of Experiments,
and Summary Experimental Elucidations of the Science of
Chemical Philosophy.

The Lectures oa Analytical Mineralogy are devoted to the
art of distinguishing minerals, the modes of examining them:
by chemical agencies and general processes of analysis; with
a suminary view of the nature of Mineralogical Science, and
its application to the useful arts and manufactures.

Account

ACCOUNT OF MReBANKS’S INSTRUMENTS. "9

Account of the Situation of the Instruments employed by
Mr. Roserr Banks, for the Meteorological Journal.

“Lue barometer, the height of which is registered every Barometer.
day at 9 A. M., is placed at the height of 27 feet from the

ground. Now we learn from Dr. Young, that the Thames Calculation of
at Buckingham stairs, 154 feet below the pavement in the its height
‘left hand arcade, is 43 feet above the level of the sea, by 5: Gata i
barometrical comparison with the Seine and {the Mediterra-

neap. But he observes, that this calculation probably gives

the height too great. Mr. Brindley, levelling from Boul-

ter’s Loek.to Mortlake, by order of the City of London, in

the year 1770, found the fall upon 41 miles to be 752 feet.

On the Jast 8 miles of this distance, however, the fall was

only 12 feet. Now if we allow the fall from Buckingham

stairs to the Lower Hope to average only 1 foot per mile,

the difference of level will be at least 35 feet. This, added

to 42 feet, the height of the ground where Mr. Banks’s

house stands above the Thames at Buckmgham stairs, and

97 feet, the height of the barometer above the ground, we

‘shall have 104 feet for the height of the barometer above 104 feet.

the level of the sea.

The thermometers hang 5 feet from the ground, against Thermometers,

a wall that has nearly an eastern aspect, and is completely

sheltered from the sun both at its back and front the whole

day, in such a manner that it cannot be affected by its heat,

either direct or reflected. Five are generally employed for
the purpose, because it is well known, if the bulbs be not

of the same size, they are subject to vary a little when the
temperature is taken at any stated hour, some rising or fall-

ing more quickly than others from this circumstance, though

a little sooner or later they would indicate the same height.
For this reason a mean of them is taken.

Under the head of weather, if any rain have fallen during weather.
the day, the word ratw is inserted in the day column. The
_ weather in the night column is noted about eleven o'clock,’
P.M., at which time, if any rain fall, rain is set down; it
it do not rain, yet no stars are to be seen, the word cloudy
_ is inserted; when there is no rain, and a greater or less num-
ber of stars are visible, it is marked as fair.

4

METEOROLOGICAL JOURNAL
For AUGUST, 1808,

Kept by ROSERT BANKS, Mathematical Instrument Maker,
in the STRAND, Lonpon.

Laan THERMOMETER.

JULY S| 2) 3) rere BA ROME-
: Pe We | ar TER.
Day of] “ [ * | & i hapicone ae oer MA
26 | 66 64 Go|ér| eose.| fair | Rain 29°82
27. «| 67 1 63 72) 60 29 83
28 3162) 66162) 29°52
29° |66|63) 70/62] 29°68
30° | 68 }67|73|61] 29°76
31+ 170) 67 172) 62 |. 29°82
AUG. |
1. | 68} 63 75 | 60 29°64
2 169165178: 60} 29°83
3 | 64/64169) 60} 30°09
4 | 67 | 65 | 75 | 60} 30°06
5 68) 71 74:1 64 | 29°88
G~ | 09} 70 76) 62 29°75
7 |68}65 173) 61) 29°86
sg | 66|65 172) 61 29°82
9 }+63)65 171) 60) 29°64
10 }62104171)621 29°78
11: $61} 64170) 59) 29-74
12. }66}06673|621 29-s2
13. | 64} 66 {68160} 99:73
14. | 67}63 |72/)60| ‘99-70
15 | 64163 |}68161| 29-66
16 | 05}63 |69| 60} 29°87
i7° | 64}|64};69160} 29-92
18° | 65!64}70;) 61) 30:03
19, | 64] 54 | 69/58} 30-10
20. | 641/65 [71/58]. 30°15
21 165!66}72}62| 30°17
209° 165|64/71;581 3016
03° | 64162 175)59 1 30°15
24°. | 65°62 172) 58 80°11
25 | 63163168] 564 . 30°11
26 | 64! 62170159.) 29°86

WEATHER.

Night. -Day.
Fair Rain
Rain Fair
Cloudy Rain
Fair Fair
Ditto Ditto |
Rain* Rain
Fair Ditto
Ditto Fair
Ditto Ditto
Ditto Ditto
Ditto Ditto
Ditto Ditto
Ditto Rain
Ditto Ditto
Diito+ Ditto t
Ditto Fair {
Ditto Ditto
Ditto Ditto
Cloudy Rain
Fair Ditto
Cloudy Ditto
Fair Ditto
Cloudy — Fair
Fair Ditto
Ditto Ditto
Ditto - Ditto
Ditto Ditte
Ditto Ditto
Cloudy Ditto
Fair Ditto
Ditto Ditto
Ditto Ditto

* Hard rain, thunder, and vivid lightning all the evening.

+ Thundef at 6-P. M.

t Thunder.

A
JOURNAL
OF
NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

OCTOBER, 1808.

aed

ARTICLE I.

Method of making a Composition for Painting in Imitation
of the ancient Grecian Manner, with Lemarks. By Mrs.
Hooker, of Rottingdean, near Brighton*.

SIR,

af Had the pleasure to communicate to the Society for the First attempt
Encouragement of Arts, Manufactures, and Commerce, in to imitate the
1786, when Miss E. J. Greenland, my method of painting Andee ih
tn imitation of the ancient Grecian manner or encaustic
painting; and in consequence, they did me the honour to
adjudge to me the gold pallet, and also afterward to approve
my account of the result of above fifty experiments per day,
which I made during more than four months in 1792, in
the hope of discovering some means of making wax, gum
mastich, and water unite like a cream, in order to expedite
the formation of the composition for imitating the encaustic
painting, which was published the same year by the Society

* Trans. of the Society of Arts, vol. XXV, p. 45. This lady’s first
account of her method of painting was published in the 10th vol. of the
Trans. of the Society.

Vou. XXI, No. 92—Ocr. 1808. G of

8s ANCYENT GRECIAN OR ENCAUSTIC PAINTING.

of Arts. I now take the liberty of sending them another
copy, but with some alterations and many additions, which
I trust will be found calculated to facilitate and improve
that method of painting, as they have arisen from much ob-
servation and reflection on several pictures I have painted
since I had last the honour of addressing the Society. In
consequence of the application of several gentlemen of the
profession, I have drawn up this paper, which, considering
the former attentions of the Society, I thought it would be
proper for me to offer first to them for their acceptance, but
if they should not think it worthy of communication, [
hope they will pardon the intrusion, and attribute it only to
the sense of gratitude I feel for the honour already confer-
xed on,
Sir,

Your most obedient servant,

EMMA JANE HOOKER.

Method of preparing and applying the composition.

/Methodof pre- Put into a glazed earthen vessel four ounces and a half
paring the : : : :

om position, of gum arabic, and eight ounces, or half a pint (wine mea-

sure) of cold spring water; when the gum is dissolved, stir

in seven ounces of gum mastich, which has been washed,

dried, picked, and beaten fine. Set the earthen vessel

containing the gum-water, and gum mastich, over a slow

fire, continually stirring and beating them hard with a

spoon, in order to dissolve the gum mastich: when suffi-

ciently boiled, it will no longer appear transparent, but will

become opaque, and stiff, like a paste. As soon as this is

the case, and that the gum-water and mastich are quite

boiling, without taking them off the fire, add five ounces

of white wax, broken into small pieces, stirring and beat-«

ing the different ingredients together, till the wax is pers

fectly melted and has boiled. Then take the composition

off the fire, as boiling it longer than necessary would only

harden the wax, and prevent its mixing so well afterwards

with water. When the composition is taken off the fire,

and in the glazed earthen vessel, it should be beaten hard,

and

ANCIENT GRECIAN OR ENCAUSTIC PAINTING. 83

and while hot (but not boiling) mix with it by degrees a
pint (wine measure) or sixteen ounces more of cold spring
water, then strain the composition, as some dirt will boil out
of the gum mastich, and put it into bottles: the composi-
tion, if properly made, should be like a cream, and the cos
lours, when mixed with it, as smooth as with oil.

The method of using it is, to mix with the composition, Method of us
upon an edithen pallet, such colours in powder as are used ‘7S
in painting with oil; and such a quantity of the composi=
tion is to be mixed with the colours, as to render them of
the usual consistency of oil colours; then paint with fair
water. The colours when mixed with the composition may
be laid on either thick or thin, 2s may best suit your sub-
ject; on which account, this composition is very advantage-
ous, where any particular transparency of colouring is re«
quired ; but in most cases it answers best, if the colours be
laid on thick, and they require the same use of the brush,
as if painting with body colours, and the same brushes as
used in oil painting. The colours, if grown dry, when mixed The colouss
with the composition, may be used by putting a little fair pei
water over them; but it is less trouble to put some water ter, when
when the colours are observed to be growing dry. In paint- 8%? 47
mg with this composition the colours blend without difficulty
when wet, and even wheu dry the tints may easily be united
by means of a brush and a very small quantity of fair
water.

When the painting is finished, put some white wax into was tobe aps
‘a glazed earthen vessel over a slow fire, and when melted, plied to the
but not boiling, with a hard brush cover the painting with Senin
the wax, and when cold take a muderately hot iron, such as
is used for ironing linen, and so cold as not to hiss, if
touched with any thing wet, and draw it lightly over the
wax. The painting will appear as if under a cloud till the
wax is perfectly cold, as well as whatever the picture is
painted upon; but if, when so, the painting should not ap-
pear sufficieutly clear, it may be held before the fire, so far
from it as to melt the wax but slowly; or the wax may be
melted by holding a hot peker at such a distance as to melt
it gently, especially such parts of the picture as should not.
Ge appear

84

Wood, can-
vassy paste-

board, or plas-

ANCIENT GRECIAN OR ENCAUSTIC PAINTING.

appear sufficiently trausparent or brilliant; for the oftener :
heat is applied to the picture, the greater will be the trans-
parency and brillianoy of colouring; but the contrary effect
would be produced, if too sudden or too great a degree of
heat was applied, or for too long a time, as it would draw
the wax too much to the surface, and might likewise crack
the paint. Should the coat of wax, put over the painting
when finished, appear in any part uneven, it may be remes=
died by drawing a moderately hot iron over it again as be-
fore mentioned, or even by scraping the wax with a knife:
and should the wax by too great or too long an application
of heat form into bubbles at particular places, by applying
a poker heated, or even a tobacco-pipe made hot, the bub-
bles would subside; or such defects may be removed by
drawing any thing hard over the wax, which would close any
small cavities. When the picture is cold, rub it with a fine
linen cloth.

Paintings may be executed in this manner upon wood
(having first pieces of wood let in behind, across the grain

ter of Paris may of the wood, to prevent its warping), canvass, card, or plas
be painted on tey of Paris. The plaster of Paris would require no other

thus

A composition

preparation than mixing some fine plaster of Paris in pow-«

- der with cold water the thickness of a cream; then put it on

a looking-glass, having first made a frame of bees wax on
the looking-glass the form and thickness you would wish
the plaster of Paris to be of, and when dry take it off, and
there will be a very smooth surface to paint upon. Wood
and canvass are best covered with some gray tint mixed
with the same composition of gum arabic, gum mastich,
and wax, and of the same sort of colours as before men-
tioned, before the design is begun, in order to cover the
grain of the wood or the threads of the canvass,

Paintings may also be done in the same manner with only

without wax. oym-water and gum mastich, prepared the same way as the

mastich and wax; but instead of putting seven ounces of
mastich, and when boiling, adding five ounces of wax, mix
twelve ounces of gum mastich with the gum-water, prepared
as mentioned in the first part of this receipt: before it is put
on the fire, and when sufficiently boiled and beaten, and

a little

ANCIENT GRECIAN OR ENE€AUSTIC PAINTING, 85

a little cold, stir in by degrees twelve ounces, or three quar
ters of a pint (wine measure) of cold spring water, and af-
terward strain it.

It would be equally practicable painting with wax alone, A composition
dissolved in gum-water in the following manner. Take see ced
twelve ounces, or three quarters of a pint (wine measure) of
cold spring water, and four ounces and a half of gum ara-
bic, put them into a glazed earthen vessel, and when the
gum is dissolved, add ejght ounces of white wax. Put the
earthen vessel with the gum-water and wax upon a slow
fire, and stir them till the wax is dissolved, and has boiled
a few minutes: then take them off the fire and throw them
into a basin, as by remaining in the hot earthen vessel the
wax would become rather hard; beat the gum-water and
wax till quite cold. As there is but a small proportion of
water in comparison to the quantity of gum and wax, it
would be necessary in mixing. this composition with the co-
lours, to put also some fair water. Should the composition
be so made as to occasion the ingredients to separate in the
bottle, it will become equally serviceable, if shaken before
used with the colours.

I had lately an opportunity of discovering, that the com- The composi-
position which had remained in a bottle since the year 1792, oy eee
in which time it had grown dry and become as solid a sub- but may he
stance as wax, returned to a creamlike consistence, and be- Soften an
came again in as proper a state to mix with colours, as when brane: =
it was first made, by putting a little cold water upon it,
and suffering it to remain on a short time. [I also lately
found some of the mixture composed of only gum arabic
water and gum mastich, of which I sent a specimen to the
- Society of Arts in 1792; it was become diy, and had much
the appearance and consistency of horn. I found, on let-
ting some cold water remain over it, that it became as fit
fer painting with, as when the composition was first pres

pared,

26 | ON OXALIC ACID.

Il.

On Oxalic Acid. By Tuomas Tyuomson, M.D. F. R. 8.
Ed. Communicated by Cuanies Harcnert, £sq.
£, B.S.

(Concluded from p. 32.)

IV. Composition of Oxalie Acid.

Composition ‘Tue knowledge of the relative weights of the elements

of oxalic acid. hich compose oxalic acid, though of importance, is not
sufficient to convey a clear idea of this compound, and in
what respect it differs from tartaric acid, alcohol, sugar, and
various other bodies possessing very different properties,
though composed of the very same elements in different
proportions.

Elements al- _It has been ascertained, by numerous and decisive expe=

ways combine

jn determinate | ; i i '
proportions _ tions in determinate proportions, which may be represented

oe by number s. For example, the numbers which correspond
numbers. © to the four elements, oxigen, azote, carbon, and hidrogen,
are the following:
Ustance. Oxigeneeccesescosees G
4 ' AZOLE. se eees seoesee ed
Carbon+-eesseeseee ee AS
Hidrogen .-- cower e ce J
Now, in all compounds consisting of these ingredients, the

riments, that elementary bodies always enter into combinas

proportion of the different constituents may always be re-
presented by these numbers, or by multiples of them;
thus, the composition of the following substances may be
thus stated.

| Oxigen. | Hidrogen | Carbon. | Azote.
ae eee Seid Woes SB ee
Compounds of Water. -<---+-. eseeece 6 +1] :
oxigen, Ni'ro- Car i) nie oxide. ce eoeee | 6 +45
gen, carbon, Carbo.icacid.++cess | 2x6 +4°5
end hichogen. Carburetted hidrogen 2X1 +4°5
“Olcfiant BAS soeeeees 1 +4°5

Nitrous gas ..-.-0.- 6
Nitric Se et 2x6 +5

Nitrous oxide cesses { = @

OW GKALIC ACID. 87

From the knowledge of this curious law, it is difficult to Alsi nee

avoid concluding, that each of these elements consists of ANA os
atoms of determinate weight, which combine according to weight of their
certain fixed proportions, and that the numbers above given eek,
represent the relative weights of these atoms respectively.
Thus, an atom of oxigen weiglis six, an atom of hidrogen
one, &c. Water is composed of one atom of oxigen, and
one atom of hidrogen; carbonic acid of two atoms of oxi-
gen, and one of carbon, &c. This curious theory, which
promises to throw an unexpected light on the obscurest
parts of chemistry, belongs to Mr. Dalton. I have else-
where illustrated it at considerable length*.

The same law holds with respect to the salts, The acids The same law
and bases always combine in determinate proportions. We hel
may affix numbers to all the acids and bases, which nume-
bers, or their multiples, will represent all the combinations
into which these bodies enter. Some of these numbers are
given in the following table:

Sulphuric acid: - 33 Barytes--++-+-+ 67
Muriatic acid -+ 18 Sadalk’semiegele vis, D4
Carbonic acid -- 16°5 Lime «+--+» -++ 93
Nitric acid «... 17 Ammonias>-s::-. §

‘These numbers may be conceived to represent the relative
weights of an integrant particle of each of these substances ;
formed on the supposition, that an atom of hidrogen weighs
1. It follows equally from this law, that the acids and Corollary.
bases combine particle with particle, or a certain determi-
nate number of particles of the one with a particle of the
other.

One of the mostimportant points in the investigation of Weight of in-
compound bodies is, to ascertain the number, which denotes cee a eaieet
the weight of an iutegrant particle of each of them, that of of importance,
an atom of hidrogen being one; because this number, ora
multiple of it, represents the weight of each, which enters
into all combinations; and because it enabies us to estuuate
the number of elementary atoms, of which each is composed,

From a careful comparison of the table of oxalates, giveuga
g preceding part of this paper, with the weight of the dif

* See System of Chemistry, 11, 424, &c, Sd Edition,
ferent

88

Integrant par-
ticle of oxalic
acid.

Component
Parts of the
acid according
to this.

Decmoposition
of oxalate of
lime by heat
explained.

ON OXALIC ACID,

ferent bases already determined*, it appears, that the weight
of an integrant particle of oxalic acid must be represented
by the number 39°5. :

Now, what number of atoms of oxigen, carbon, and hi-
drogen, go to constitute an integrant particle of oxalic acid ?
We have assigned the relative weights of each of these
atoms, aud we have ascertained the relative propo-tions of
the respective elements of oxalic acid. From these data it
%s easy to solve the probiem. An integrant particle of oxa-
lic acid consists of g atoms combined together, namely, 4
atoms of oxigen, 3 of carbon, and 2 of hidyogen.

A aioms of oxigen weigh*+-.+--4X%6 = 24
3 atoms of Carbonee+eeseeeeee 3 KX 4:5 = 13S
2 atoms of hidrogen+++++++44-2X1 =2

ae a

Totale esses eeeees 39°5

which together make up the weight of an integrant partiele
of oxalic acid.

According to these proportions, 100 parts of oxalic acid ig
composed of

Oxigen.eseeeerecees 61
ASATDOU c/o eas a sioe a2! 4
PRrOgeH s,» 40:8 eee 'eee 8

i . _—_—_—_—

100 '
numbers which do not indeed exactly correspond with the
result of the preceding analysis, but which approach suffis
ciently near it, to give the reasoning employed considerable
probability at least, if it does not lead to certainty.

We may now examine the decomposition which takes
place, when oxalate of lime is exposed to heat. Let an
atom of oxigen be w, an atom of carbon c, and an atom of
nidrogen, A. An integrant particle of oxalic acid may be
represented by 4w+3c+4+ 2h. We may represent the
composition and weight of an integrant particle of each of
the substances into which oxalic acid is decomposed by
heat, by the following symbols and numbers ;

* For these we hts, and the method of determining them, I refer the
reader to my System of Chem: ry, -d Edi ‘o., UI, 619. The numbeys
which J have tuere as si gned are, i am persuaded, eter too low.

Carbonie

ON OXALI€ ACID. 89

Carbonic acid .--..-2w ec weights» 165
Carburetted hidrogen c+ 2h -+++ ++ 65
Carbonic oxide+-++++ we -seeeee 10°5
Water --cossesse se wth <enace F

AP aCoalli« ese sie 6/9 Ci, iuelssjeuste AS

We may now conceive 3 particles of oxalic acid to be de-
composed at once, and to resolve themselves into these sub-
stances, in the following proportions:

4 particles of carbonic acid-+-+++» = 8wtdAe

2 particles of carburetted hidrogen = 2ce+ 4h

2 particles of carbonic oxide++++++ = Qw+ 2e

2 particles of water ---+++e-+e+*+ = Qw +2h

1 particle of charcoal -+++++++++ = le

Totales-eeerses 12wW+090c+ 6h
8 particles of oxalic acid-++-+++- =12w+Qc+6h

We see that such a decomposition is possible. It remains
only therefore to see, whether the weights of these sub-
Stances, which result from this hypothesis, correspond with
the preceding analysis, Now,

A particles of carbonic acid weigh «+++ 4 % 165 = 66

2 -carburetted hidrogen ** 2% 65 = 13
Q——- - carbonic acid++sessss+. 2 % 105 = 2
QD ——- —-— watereceseecereesecee 2K F == TA
B -———--—-— charcoal-.esesescenees A>) == Ae

4

ee,

We Eatlin to cletelutiotejal evela late) falsetto 118°5

Reducing these proportions to 100 parts of acid, and
joining together the two inflammable gasses, the numbers
come out as follows :

Carbonic acid-++-++ 55°70 we actually obtained 59°53
Inflammable air---+ 28°GG. we eeeeeeccseeere 2498
DUUIAHGE: 2a: 0)s\elclsio cee V1°SI1 eesere cevcee weoe LIS]
Charcoa] +++++++.0+ 3°SO ss ccee cevnee cece 4°68

100°00 100°00

It is impossible to expect exact correspondence between Hypothesis
the theory and analysis, till the numbers representing the eyrcii neanly:
i . weights ~~

90 ON OXALIC ACID.

weights of the elementary atoms be ascertained with more
rigid accuracy, than has hitherto been done. I satisfied my-
self with taking the nearest round numbers, which are suf-
ficient at least to show an evident approximation to the pro-
portions obtained by experiment.

VY. Composition of Sugar, and Formation of Oxalic Acid.

Composition of | When a compound body is decomposed, and resolved into

Erste fore 2 number of new substances, the products are almost al-

exalicacid, | ways simpler, or consist of integrant particles composed of
fewer atoms than the integrant particles of the original
body. Thus, though oxalic acid is composed of 9 atoms,
none of the products evolved, when that acid is decomposed
by heat, contain more than 3 atoms. Hence it is probable,
that sugar is a more compound body than oxalic acid, be-
cause nitric acid resolves it intoa variety of new compounds,
one of which is oxalic acid. It may be worth while to ex-
amine the action of mitric acid on sugar, and the tormaticn
of oxalic acid, more closely than has hitherto been dene, as
the investigation will furnish some data for estimating the
composition of sugar.

200 grainsof ‘Two hundred grains of pure crystallized sugar, being

sugar treated treated with diluted nitric acid in the usual way, yielded

pity hag 200 cubic inches of carbonic acid, 64 cubic inches of nitrous
gas, and 70 cubic inches of azotic yas, But these numbers,
though the result of a good inany experiments, are not to be
considered as very exact. The uncertainty depends upon
the property, which the solution has ef producing more
gas after the sugar is decomposed, at the expense of the
oxalic acid formed. Now it js dificult to stop at the pres
cise point.

116 grains of The whole weight of oxalic acid, which can be obtained

anny from 200 grains of sugar, amounts to 116 grains, If the
experiment be properly conducted, the whole of the sugar
is decomposed, or at least the quantity of residuary matter
issmall, :

From the preceding statement, there is reason to conclude,
that 100 grains of sugar, when decomposed by nitric acid,
yield, :

i, Oxalic

ins

acid, I confess I am disposed to ascribe this surplus to er-
‘Tours in the experiments, and to believe, that the whole of

ON OXALIC ACID, 9 i
, Grains.
i. Oxalic acid crystals 58 grains, or real acid-> 45 Oxalicand care
g. Carbonicacid 100 cubic inches, equivalent to 46°5: pomicaaite.

while there are evolved obviously, by the decomposition of
the nitric acid,
Grains,
1. Azotic gas 35 cubic inches, equivalent to 10°62
2. Nitrous gas 32 cubicinches, equivalent to 10°85

Now, as nitric acid contains no carbon, it is obvious,
that the oxalic acid formed, and the carbonic acid evolved,
must contain the whole carbon contained in 100 grains of
sugar,

Grains.
45 grains of oxalic acid contain of carbon 14°40

46°5 graias of carbonic acid contain of ditto 13°02

Ul teilisiate aiaiadelapeistoleisveiste 27:42
therefore 100 grains of sugar contain 27} grains of carbon. 499 sugar come
The azotic gas and nitrous gas must have been originally tain 27'5 cam
in the state of nitric acid, and must have given out oxigen °°
whey they were evolved. But nitric acid is composed of
Oxigen.
AZOtCs sscrccverccserecccses 10°62 + 25
Nitrous gas seesesseeere sree 1085 + 45

25°S
Therefore they must have parted with 29°5 grains of oxi-
gen. We are at liberty to suppose, that the-whole of this
oxigen went to the formation of carbonic acid. Now, 46°35
grains of carbonic acid are composed of
Grains,
Oxigensseesccssees 38°5
Carbon--++ssssee+2 13°0
465
_ From this it appears, that in the carbonic acid there were A pparent sur.

4 grains of oxigen more than was furnished by the nitric ae of oxis
n.

the oxigen of the carbonic acid was furnished by the nitrie
acid.

92 ON OXALIC ACID.

acid. This bemg admitted, it follows, that the carbon
of the carbonic acid, and the whole constituents of the
oxalic acid, were furnished by the sugar. These are as

follows:
Grains,
Garbone ss os. eeceeoee te eosceneeereseeuse ey fel

Oxigen in 45 grains oxalic acid -..+++ 28°8
Hidrogen in ditto escessssecceccscss 1°83

58°1
If this total be substracted from the 100 grains of sugar
score used, there will be a remainder of 41°9 grains. As this
formed. Quantity of the suyar has disappeared, and is no where to
be found among the products, we must suppose, that it has
assumed the form of water. Now 41:9 grains of water are
composed of
Oxigen-sseesesescoes 359
Hidrogen ++ecsscece §
. 41°9
Adding these quantities to the preceding products, we che
tain the composition of sugar, as follows:

Component Oxigen -+s+ceee os 64°7
Parts of sugar. Carbon e200 86 eevee O7°S
Hidrogenseceeoveee 78

100°0

This cannotbe Though the process of reasoning, which led to this analy=
a: m- sis of sugar, is too hypothetical to be trusted implicitly, yet
‘ I am persuaded, that it is to a certain degree correct, and
that the result obtained does not deviate very far from the
but corrovorae truth. If we compare Lavoisier’s statement of the compos
Br analysis. sition of sugar obtained in a different manner, though by
a mode of reasoning not less hypothetical, we shall be
surprised at its near coincidence with mine. His numberg
are
Oxigensessesersecees G4
Carbon. ovseveseccse’ 98
Hidrogen.cscoscssss §

— Ss

100

ON OXALIC ACID. bu 9S

It is true, that two different hypotheses may lead to the
same result, and yet be both wrong; but this becomes in-
‘finitely improbable in the present case, when we consider,
that the proportion of carbon, which I assign to sugar, must
at all events be nearly correct.

We have no diréct method of determining the weight of Farther argu.
an integrant particle of sugar; but if the accuracy of the an
preceding analysis be admitted, it furnishes us with an in-
direct one, which cannot be rejected; for it is clear, that the
atoms of oxigen, carbon, and hidrogen, will be to each
other respectively, as the numbers % , 2%, £; and these num=
bers reduced to their lowest terms become 5, 3, 4, nearly,
which, being primes with respect to each other, must repre=-
sent the number of atoms, of which an integrant particle of
sugar is composed. Sugar then isa compound of 12 atoms; Integrant par.
namely, five of oxigen, three of carbon, and four of hidro- ticle of sugar.
gen; the weight of an integrant particle of itis 47°5, and
its symboiis 5w +3c 4 4h. It differs from oxalic acid Its difference
merely in containing an additional atom of oxigen and two ee, oxalic
of hidrogen. If we had any method of removing these ea
substances, without altering the proportion of the other con-
stituents, we should obtain a much greater quantity of
oxalic acid from sugar than we can at present; but nitric

_ acid acts by removing one half of the carbon in the form of
carbonic acid; the sugar, deprived of this, resolves itself

into oxalic acid and water. Suppose two particles of sugar Theory of het
acted on at once, the symbol for them will be 10w + 6e¢ + 8h, formation of
Let three atoms of the carbon be removed by the action Cee
of the nitric acid, there will remain 10w+3¢4+ 8h. F
Now

A particle of oxalic acid = 4w+3ec42h

Six particles of water-»> = 60+ +6h

l0w+3c+ 5A,
which is just the quantity of oxalic acid left. This will.
give us some idea of the way in which the formation of
oxalic acid by nitric acid is accomplished.“ And although
the series of changes is probably more complicated, yet
they are ultimately equivalent to the preceding statement.
T allude to the formation of malic acid, which is said to pre- Malic acid.
cede

94 APPLICATION OF THE GAS FROM COAL.

¢ede the oxalic acid, and afterward to be converted into it
by the subsequent action of nitric acid; but on the compo
sition and formation of this latter acid avoid making any.
observations at present, as I propose to make them the sub
ject of a separate dissertation.

—

RON PEDLE ES Et BE OER A SS A

HI.

An Account of the Application of the Gas from Coal to ece«
nomical Purposes. By Mr. Witt1am Murpocn. Com-
municated by the Right Hon. Sir Joseru pat Bart.
K. B. P.R.S.*

Light from — Tue facts and results intended to be communicated in
Co ae this Paper are founded upon observations made, during
the present winter, at the cotton manufactory of Messrs..
Phillips and Lee at Manchester, where the light obtained
by the combustion of the gas from coal is used upon a very
large scale ; the apparatus for its production and application
having been prepared by me at the works of Messrs. Boul-
ton, Watt, and Co. at Soho.
Quantity of The whole of the rooms of this cotton mill, which is, I
ye fala believe, the most extensive in the United Kingdom, as well
son with can. as its counting-houses and store-rooms, and the adjacent >
ac, drecliretnquns of Mr. Lee, are lighted with the gas from
coal. The total quantity of light used during the hours of
burning, has been ascertained, by a comparison of shadows,
to be about equal to the light which 2500 mould candles of
six in the pound would give; each of the candles, with
which the comparison was made consuming at the rate of
4-10ths of an ounce (175 grains) of tallow per hour.
The quantity of light is necessarily liable to some varia-
tion, from the difficulty of adjusting all the flames, so as
Experiment to be perfectly equal at all times; but the admirable preci-
made under gion and exactness, with which the business of this mill is

very favourable : Z i
circumstances, conducted, afforded as excellent an opportunity of making

® Philos. Trans, for 1808, p, 124.
the

con “im
2 >

APPLICATION OF THE GAS FROM COATo 95

the comnarative trials I had in view, as is perhaps likely te

be ever obtained in general practice. Aud the experiments

being made upon so large a scale, and for a considerable

period of time, may, I think, be assumed as a sufficiently

accurate standard for determining the advantages to be ex-~

pected from the use of the gas lights under favourable cir-

cumstances,
It is not my intention, in the present paper, to enter into Method tn

a particular description of the apparatus employed for pro- Niger es
ducing the gas: but I may observe generally, that the coal applied.
is distilled in large iron retorts, which during the winter
season are kept constantly at work, except during the in=
tervals of charging; and that the gas, as it rises from them,
is conveyed by iron pipes into large reservoirs, or gasome-

_ ters, where it is washed and purified, previous to its being
couveyed through other pipes, called mains, to the mill.
These mains branch off into a variety of ramifications (form-
ing a total length of several miles), and diminish in size, as
the quantity of gas required to be passed through them be-~
comes less. The burners, where the gas is consumed, are
connected with the above mains, by short tubes, each of
which is furnished with a cock to regulate the admission of
‘the gas to each burner, and to shut it totally off when re«
quisite. This latter operation may likewise be instantane-
ously performed, throughout the whole of the burners in
each room, by turning a cock, with which each main is pro

' vided, near its entrance into the room.

The burners are of two kinds: the one is upon the prin~ Two kinds of
‘ciple of the Argand lamp, and resembles it in appearance ;D¥ters.
_ the other is a small curved tube with a conical end, having

three circular apertures or perforations, of about a thirtieth
‘of an inch in diameter, one at the pomt of the cone, and
two lateral ones, through which the gas issues, forming
three divergent jets of flame, somewhat like a fleur-de-lis.

The shape and general appearance of this tube, has pro-

_ ured it among the workmen the name of the ‘cockspur

" burner.

_ The number of burners employed in all the buildings 904 bumers,

"amounts to 271 Argands, and 633 cockspurs; each of the

- former giving a light equal to that of four candles of the
description

98 APPLICATION OF THE GAS FROM €0AL.

description abovementioned ; and each of the latter, a light

equal to two and a quarter of the same candles; making
giving light — therefore the total of the gas lght a little more than equal
scans eesene to that of 2500 candles. When thus regulated, the whole
of Gto the lb. of the above burners require an hourly supply of 1250 cu~
<1 aaa bic feet of the gas produced from cannel coal; the superior
from cannel quality and quantity of the gas produced from that material
coal hourly. having given it a decided preference in this situation, over
every other coal, notwithstanding its higher price.

The time during which the gas light is used may, upon
an average of the whole year, be stated at least at two hours
per day of twenty-four hours. In some mills, where there

is over work, it will be three hours; and in the few where
night work is still continued, nearly twelve hours. But
taking two hours per day as the common average through-
out the year, the consumption in Messrs. Philips and Lee’s
This requires mill, will be 1250 X 2 = 2506 cubic feet of gas per day; to
eee as produce which, seven hundred weight of cannel coal is re- -
retorts, quired in the retort. The price of the best Wigan cannel
(the sort used) is 13$d. per cwt. (22s. 6d. per ton), deli«
vered at the mill, or say about eight shillings for the seven
hundred weight. Multiplying by the number of working.
days in the year (313), the annual consumption of cannel

will be 110 tons, and its cost $125. ‘ .
andabove1-sq bout one third of the above quantity, or say forty tons of
as much good good common coal, value ten shillings per ton, is required

common coal for fuel to heat the retorts; the annual amount of which is
to heat them.

£20. :
etude se The 110 tons of cannel coal, when distilled, produce about
coak. 70 tons of good coak, which is sold upon the spot at 1s. 4d.
per cwt. and will therefore amount annually to the sum of
£93.
Tar, The quantity of tar produced from each ton of cannel

coal is from eleven to twelve ale gallons, making a total

annual produce of about 1250 ale gallons, which not hav~

ing been yet sold, I cannot determine its value; but when-

ever it comes to be manufactured in large quantities, it

_ cannot be such as materially to influence the economical
Froduce tri: nae ‘

fue. statement, unless indeed new applications of it should be
discevered,

The

‘APPLICATION CF THE GAS FROM COAL. 97

The quantity of aqueous fluid, that came over in the Aqueous fluid.
course of the observations which I am now giving an account
of, was not exactly ascertained, from some springs having
got into the reservoir ; and as it has not been yet applied to
any useful purpose, I may omit further notice of it in this
statement. .

The interest of the capital expended in the necessary ap- Interest of cas
paratus and buildings, together with what is considered as pie
an ample allowance for wear and tear, is stated by Mr. Lee
at about £550 per annum: in which some allowance is
made for this apparatus being upon a scale adequate to the
supply of a still greater quantity of light, than he has occa-
sion to make use of.

He is of opinion, that the cost of attendance upon candles Attendance
would be as much, if not more, than upon the gas appara- 0t more than

: : : ; , on candles,

tus; so that in forming the comparison, nothing need be ;
stated upon that score, on either side.

The economical statement for one year then stands thus:

Cost of 110 tons of cannel coal .--+++---++ £1295

Expense of the
Ditto of 40 tons of common ditto -++++.+. 20 gas lights,
145

Deduct the value of 70 tons of coak..-.+. 93
The annual expenditure in coal, after de-
‘ducting the value of the coak, and without

allowing any thing for the tar, is therefore 52
»And the interest of capital, and wear and tear

ef apparatus ce ccecrecccesccscecesces 550

making the total expense of the gas apparatus, about £600
per annum. —

That of candles, to give the same light, would be about That of cane
£2000. For each candle consuming at the rate of 4 tenths ‘es
of an ounce of tallow per hour, the 2500 candles, burning
upon an average of the year two hours per day, would, at
one shilling per pound, the present price, amount to nearly
the sum of money abovementioned.
__ If the comparison were made upon an average of three The compari-
hours per day, the advantage would be still more in favour mira
of the gas light; the interest of the capital, and wear and gas where the
Vou. XXJ—Ocr. 1808, H tear

98 APPLICATION OF THE GAS FROM COAL.

light is conti- tear of the apparatus continuing nearly the same as in the
oy ial former case; thus,

1250 X 3 = 3750 cubic feet of gas per day, which would
be produced by 10$ewt. of cannel coals; this, multiplied by
the number of working days, gives 168 tons per annumy
which, valued as before, amounts to «--+++e+e+ £188.

And 60 tons common coal for burning under
the retorts will amount to---eeeseseeeee 30

eae eet

218
Deduct 105 tons of coak at 26s. Sd. seeees 140

Leaving the expenditure in coal, after de-
duction of the coak, and without allow-
ance for the tar, at eeeeeetr eevee seeeoese 78 7

Adding to which the interest and wear and tear of appara-

tus, as before, the total annual cost will not be more than

£650, while that of tallow, rated as before, will be £3000.
Put anincreas- It will readily occur, that the greater number of hours the

ed expense of : i Aiba) ae : ies :
papasiaee, S22 burnt, the greater will be its comparative economy ;

_quired. although in extending it beyond three hours, an inerease of
some parts of the apparatus would be necessary.
Advantage If the economical comparison were made with oils, the ade

paare on dese. vantages would be less than with tallow.

Beginning of | The introduction of this species of light into the establish
Ait aaa ment of Messrs. Philips and Lee has been gradual; begins
ning in the year 1805, with two rooms of the milly the
counting-houses, and Mr. Lee’s dwelling-house., After
which, it was extended through the whole manufactory, as
expeditiously as the apparatus could be prepared..
Inconvenience At first, some inconvenience was experienced from the
ae smell of the unconsumed, or imperfectly purified gas, which
may in a great measure be attributed to the introduction of
successive improvements in the construction of the appara-
tus, as the work proceeded. But since its completion, and
since the persons, to whose care it is confided, have become
familiar with its management, this inconvenience has been
obviated; not only in the mill, but also in Mr. Lee’s house,
which is most brilliantly illuminated with it, to the exclus
sion of every other species of artificial light.

The

APPLICATION OF THE GAS FROM COAL. 09

The peculiar softness and clearness of this light, with its Its advantages
almost unvarying intensity, have brought it into great fa- ga
vour with the work people. And its being free from the
inconvenience and danger, resulting from the sparks and
frequent snufling of candies, is a circumstance of material
importance, as tending to diminish the hazard of fire, to
which cotton mills are known to be much exposed.

The above particulars, it is conceived, contain such infor- Origin of the
mation, as may tend to illustrate the general advantages at- Shea abr
tending the use of the gas light; but nevertheless the Royal
Society may perhaps not deem it uninteresting, to be ap-
prised of the circumstances, which originally gave rise in my
mind to its application, as an economical substitute for oils
and tallow.

It is now nearly sixteen years, since, in a course of expe- In 1792.
riments I was making at Redruth in Cornwail, upon the

_ quantities and qualities of the gasses produced by distillation

from different mineral and vegetable substances, T was in-
duced by some observations I had previously made upon
the burning of coal, to try the combustible preperty of the
gasses produced from it, as well as from peat, wood, and
other inflammable substances. And being struck with the
great quantities of gas which they afforded, as well as with
the brilliancy of the light, and the facility of its production,
PF instituted several experiments, with a view of ascertaining
the cost, at which it might be obtained, compared with that

of equal quantities of light yielded by oils and tallow.

My apparatus consisted of an iron retort, with tinned First experi.
copper and iron tubes, through which the gas was conducted ™-
to a considerable distance; and there, as well as at inter=
mediate points, was burned through apertures of varied
forms and dimensions. The experiments were made upon
coal of different qualities, which I procured from distant
parts of the kingdom, for the purpose of ascertaining which
would give the most economical results. The gas was also
washed with water, and other means were employed to pu-
rify it.
_ In the year 1798, I removed from Cornwall to Messrs. Practically ap-
Boulton, Watt, and Co’s. works for the manufactory of pled sp ltee,

steam engines at the Soho foundry ; and there I constructed

‘ He an

100 APPLICATION OF THE GAS FROM COAL.

an apparatus upon a larger scale, which during many suc-
cessive nights was applied to the lighting of their principal
building, and various new methods were practised of wash-
ing and purifying the gas.
Illumination These experiments were continued with some interrup-
eee tions, until the peace of 1802, when a public display of this
light was made by me in the illumination of Mr. Boulton’s
manufactory at Soho, upon that occasion.
Sinceregularly Since that period, I have, under the sanction of Messrs.
Scie Race Boulton, Watt, and Co. extended the apparatus at Soho
foundry, so as to give light to all the principal shops, where
it isin regular use, to the exclusion of other artificial light ;
but I have preferred giving the results from Messrs. Philips
and Lee’s apparatus, both on acconnt of its greater extent,
and the greater uniformity of the lights, which rendered the
comparison with candles less difficult.
bh i atid At the time I commenced my experiments, I was cer-
the gas long tainly unacquainted with the circumstance of the gas from
known, —_coal having been observed by others to be capable of com-
bustion; but I am since informed, that the current of gas
escaping from Lord Dundonald’s tar ovens had been fre-
quently fired; and I find that Dr. Clayton, in a paper in
volume XLI of the Transactions of the Royal Society, so
long ago as the year 1739, gave an account of some obser-=
vations and experiments made by him, which clearly mani-
fest his knowledge of the inflammable property of the gas,
butfirstappliel which he denominates ‘ the spirit of coals;” but the idea
aris aaa of applying it as an economical substitute for oils and tal-
Mr. Murdoch. low does not appear to have occurred to this gentleman, and
I believe I may, without presuming too much, claim both
the first idea of applying, and the first actual application of

this gas to economical purposes.

em Ge

REMARK.

Intention of As an attempt to light the streets of the metropolis by
applying coal means of coal gas has made much noise, and is meant, as
gas tolightthe f i ;
streets of the it is said, to be brought before parliament next session,
metropolis. whatever tends to elucidate the subject cannot be uninte-
resting. The account here given by Mr. Murdoch, whose

experiments

APPLICATION OF THE GAS FROM COAL. 101

experiments were mentioned in our Journal for June 1805,
is perfectly satisfactory with respect to the application of
coal gas as the material of furnishing hght, and its compa-
rative cheapness and advantages, at least in a coal country :
but it must be obvious, that his calculations are by no means -
adapted to London.

Mr. Murdoch states the annual expense for lighting the Mr Murdoch’s
manufactory of Messrs. Philips and Lee at £600; and ob- peared
serves, that, to produce an equal light by candles would London.
cost £2000. The caunel coal employed however, as being
most profitable though sold at the highest price, costs there
only 22s. 6d. per ton, and the coal for heating the retorts
only 10s. per ton. The coak produced there sells at 26s. 8d.
per ton. Now on inquiry at a very respectable coal mer-
chant’s in London I find, that cannel coal sells here at £4
per ton; the coal for the furnaces may be averaged at 45s.,
and the coak at 50s. It must be observed too, that the ap-=
paratus being manufactured on the spot at Birmingham, it
of course was so much the less expensive. The- statement
for the metropolis therefore would probably stand thus.

Cost of 110 tons of cannel coal at £4 +++++-+. £440 Calculation for

40 tons of common coal at 45s.-+++---. 90 the metropolis

Interest of capital, and wear and tear of appara- for two houis :
tus eeoeesoepveveeveeseeeeoeseoeosese ee teeaeaeeeaoaaesneeve 650

1180
Deduct for 70 tons of coak at 50S.¢+eeeseeeeee 175

1005

Thus the expenditure would be £1005 to procure light
equal to that of as many candles as would come to £2000.
This is the calculation for light for two hours a day. If we
take it for three hours a day, according to Mr. Murdoch’s
second estimate, the calculation will be
MEIRLOMEUOE Cannel Coal «2 6 s.+ aiecte seiceeteas £672 ~~ or if extended

GO tons of common Coal -++r-seeeeeeseeeeees 135 to three,
Apparatus as before oesecsesesssesccescesess 650

1457
Deduct for 105 tons of coak sscccceteseseses 963

| 1194
or £1194 to procure the light of £3000 worth of candles.
ad When

102

Fora ee
time more
vourable.

But various de-
ductions must :
be made.

Estimate with-
out these de-
ductions,

APPLICATION OF THE GAS FROM COAL,

When the gas is applied to lighting the streets by night-
~ however, perhaps we may state the time at an average as
ten hours a day; and the louger the time, as Mr. Murdoch
justly observes, the greater will be the balance in favour of
the gas, since the apparatus will remain nearly the same.
But then, there are several circumstances farther to be taken
into consideration, Though the greater part of the appara-
tus would not be altered, it appears an increase of some
parts would be necessary, if the burning were to be conti-
nued beyond three hours. We must add too to the expen-
diture, the rent of houses in every part of the town for
holding the furnaces and apparatus, the wages of persons
to attend these, aud the salaries of clerks, none of which
were necessary in Mr. Murdoch’s case. Besides, the price
of coal must probably be increased by the additional con-
sumption, and that of coak would certainly fall very greatly,
from the quantity produced beyond the demand for it. The
estimate too must be made in comparison with common
lamp oil, the expense of which may be reckoned at not
more than two thirds the cost of candles, Farther, the eas
lights are said to give double the light of the common street
lamps, and this is certainly an accommodation to the pub-
lic: but then, as the calculation of Mr. Murdoch is found-
ed very properly on the quantity of light given, this will
affect the estimate in a similar ratio, so that the expense of
the oil must be diminished by one half. On these grounds
the estimate would appear somewhat in the following form,
taking it at an average of ten hours every night,

550 tons of cannel coal «++ esse eee e seers es £2900
900 tons of common Coal: tee ascun esses saan DAae
Interest of capital, and wear and tear of appa-
AUIG ,, jwieie pele (5 e)s! aye s-0.n\9\pie ¢iaip igi wis 90m eieleie aan Bea

S Eneeteaed

3450"

Deduct for 350 tons of COAK+ sever eevvcrevas 875

= Dover
The expense of lighting to an equal extent with oil, ac-
cording to the estimation above give , would bv £3333. It
must be observed, Hoping | is | here allowed for the coal-tar,
the

age

*

EXPERIMENTS ON THE SPLEEN.

the produce of which from the above quantity of coal, ac-
cording to Mr. Murdoch, would be about 6900 ale gallons,
or 7000 wine gallous; as he has leit it out of his estimate
from being oi too trifling value. Neither have I taken into
account the expense for rents of houses, salaries, and wages,
with the other circumstances abovementioned, that must af-
fect the profits; though I have said enough to show, that
" these, if any, must differ very widely indeed from the enor-
mous gaius held out to the public, to induce incautious
individuals to embark in the project, when it was first set on
foot.

For farther remarks on the coal gas lights see our Jour-
nal, vol. XVI, p. 73, 83,308. C.

IV.

Farther Experiments on the Spleen. By Everaxp Home,
Esq FBS

‘Tue results of the experiments already brought for-
ward} having established the fact, that fluids received into
the stomach, when the pylorus is closed, pass through the
spleen into the circulation of the blood ; it became an object
to determine, by experiment, whether this takes place, when
the parts are in a natural state.

The ass appeared, on many accounts, the best subject for
this purpose ; and as it is made use of to teach the veteri-
nary pupils the anatomy of that tribe of animals, I applied
to the Professor for permission to make my experiments in
the theatre of the college.

This was granted me in the most obliging manner; the
subjects were also supplied by the College, and Mr. Sewell,
the assistant Professor, gave me his personal aid with a de-
gree of zeal and ability I have rarely met with, and have
much pleasure in acknowledging.

* Philos. Trans. for 1808, p. 133.
+ See our Journal, vol. XX, p. 374.
In

103

Object in view.

The ass a fa-
vourable sub-

ject.

104

Exp. 1.
Tincture of
rhubarb given
diluted with
‘water,

The animal
pithed.

Blood drawn
from the sple-
nic vein and
left auricle.

\

State of the
spleen.

Rhubarb con-
veyed to it,
but not to the
liver.

Rhubarb in the
urine most:
next in infu-
sion of spleen,
then in serum
from splenic
vein, and least
in serum from
left auricle and
infusion of l-
ver,

EXPERIMENTS. ON THE SPLEEN.

In making the following experiments, I had the assist-
ance of Mr. Sewell, Mr. Brodie, Mr. William Brande, and
Mr. Clift.

Experiment 1. An ass, which had been kept twenty-four
hours without hay, to prevent the liquor that was to be
poured into its stomach from being soaked up and retained
there, on the evening of the 3d of December, 1807, had a
drench given it, consisting of half a piut.of the spirituous
tincture ef rhubarb, diluted in half a pint of water. On
the morning of the 4th, this was repeated at eight o'clock,
and again at twelve. At two o’clock the animal was pithed,
so as to destroy its sensibility; and before the circulation
was entirely stopped, six ounces of blood were taken from
the splenic vein into a graduated glass measure, and a simi-
lar quantity was taken from the left auricle of the heart,
into a vessel of the same kind: these were allowed to coagu-
late and separate their serum.

he spleen was large and turgid; upon making sections
of it, the cells were found to be very numerous; and to-
wards the great end and near the edge, they were particu-
cularly distinct to the naked eye. The cut surface had a
strong smell of rhubarb, and when it was applied to white
paper wetted with the alkaline test, an orange tinge was
produced. This was strongly contrasted by a stain made in
the same manner with a section of the liver, which had no
such tinge, nor did the liver give the slightest smell of rhu«
barb.

Infusions were made of the spleen and liver under similar
circumstances; these were strained off into separate glasses,
and tested by the alkali. The urine was tested in the same
way. The serum, from the different portions of blood, was
also poured off ito separate glass vessels, to which the test
was added. In nineteen hours after the blood had been
taken from the veins, they were all compared together. The
urine had so Geep a tinge, that it nearly resembled the pure
tincture of rhubarb in appearance; the others had a tinge,
although in very different degrees; the quantity of rhubarb
they contained was estimated by adding tincture of rhu-
barb to alkaline water so as to produce corresponding tints,
The infusion of spleen had a tint equal to sixty drops of

tincture

EXPERIMENTS ON THE SPLEEN. 103

tincture of rhubarb in two ounces of alkaline water: the
serum of the splenic vein to fifteen drops: the serum from
the left auricle of the heart, to three drops. The infusion
of the liver gave no orange tinge, but had it not been ob-
scured by the red particles of the blood, it must have been
equal to that of the serum from the auricle,

The connecting membrane between the stomach and Connecting

: . membrane be-

spleen was attentively examined, very few absorbent vessels ieee anes
were seen, and these were not in a turgid state, they were mach & spleen
traced to the chain of glands situate near the edge of the seri
spleen, which receive the absorbeuts of the stomach, but
none were detected passing beyond the glands, nor did the
glands admit quicksilver to pass through them towards the
spleen.

Exp. 2. The former experiment was repeated upon ano- Exp.2. |
ther ass, with similar results, but less strongly marked; the ssnobnae ci
cause of this difference was explained by the abdominal vis- degree; per-
eera being in an inflamed state. ; raat Sat

The urine was less impregnated with rhubarb, the infu- viscera.
sion of the spleen had a lighter tinge, and the serum of the
splenic vein had it in a still less degree; but evidently ex-
ceeding that of the serum from the vena cava inferior
opened just below the diaphragm, which was substituted
for the left auricle of the heart, with a view to vary the ex-
periment.

Exp. 3. The same experiment was made on a third ass Exp. 3. Similar.
with similar results.

Exp. 4. An ass that had been kept four days without Exp. 4.
water, and two without solid food, on the evening of the 8th Ce
of January, 1808, had a ball given it, containing half an :
ounce of powdered rhubarb; on the gth, at seven o’clock
in the morning, this was repeated ; a third was given at nine
o'clock, and a ourth at twelve. At two o'clock. the ass was
pithed, and four ounces of blood were taken from the sple-
nic vein, and the same quantity from the left auricle of the
heart.

The spleen was found contracted to half the size of those Spleen much
in the former experiments; when cut into the cells were contacted.
small, and it required a magnifying glass to see them dis-
finctly. The-substance was compact, and bore a near re-=

semblance

‘

106 EXPERIMENTS ON THE SPLEEN.

semblance to a portion of liver; so that in this state the
blood vessels, particularly the veins, must have been much
contracted in their diameters.
Other viscera. he stomach contained about two ounces and a half of
a gelatinous substance mixed with rhubarb, the small in-
testines were nearly empty, but the caecum and colon con-
tained several quarts of water, in which the rhubarb was
more evident both to the sight and smell, than in the sto-
mach.

The absorbent glands upon the edge of the colon were

: ranged in two rows, one on each side of the great vein, and
were exceedingly numerous. In the space between these
rows of glands, in some places twenty trunks of absorbent
vesseis could be readily counted, of a very large size.

Rhubarb in The urine was impregnated with rhubarb, so as to acquire

ae MES an orange tinge from the addition of the test; but the infu-
sion of the spleen, and the serum of the different portions
of blood, did not contain it in sufficient quantity to have the
colour heightened by alkali.

Exp. repeated Eup. 5. The last experiment was repeated upon another

Berean ass. Two ounces of blood were taken from the splenic vein,
two from the large vein of the colon, and two from the infe-
rior vena cava in the lower part of the loins.

The spleen had the same appearance as in the last expe-
riment.

The stomach contained nearly a pint of moderately solid
contents, in which the rhubarb was very evident. The
small intestines were nearly empty; but the caecum and be-

; ginning of the colon contained several quarts of liquid,
strongly impregnated with rhubarb.

The absorbent glands and vessels had the same appearance
as in the former experiment. :

The urine when tested was found impregnated with rhu-
barb.

The proportions of serum of the blood taken from these
different veins, when tested by the alkali, appeared to be
very-much alike; at least that from the splenic vem was
not more tinged than the others.

Spirituous li- Exp. 6. Having been informed by Mr. Sewell}, that spi-
i Aiea rituous liquors, given in large quantities to horses, produce
inflammation

fa
EXPERIMENTS ON THE SPLEEN. 107

inflammation of the brain, and sometimes death; and this of the brain ir
information having been in some measure confirmed by an Beiscs:

ass in a weakly state, that had taken half a pint of the spi-

vituous tincture of rhubarb in the evening, dying in the

night; I thought it right to make a comparative experiment

with the infusion of rhubarb, to determine whether the re-

sult would be the same as with the tincture.

February 9, 1808. An ass had a pint of infusion of rhu- Eup 6.
barb given to it iu the evening; the same dose was repeated. aqueous infu-
at six o'clock in the morning of the 10th; and again at nine aoe rhubarb
o’clock, and at twelve. At two o’clock the animal was
pithed, and two ounces of blood were taken from the splen-
ic vein, two from the vein of the colon, and two from the
inferior vena cava in the lower part of the loins.

The spleen was found turgid, and large; when the cut Rhubarb found
surface was rubbed on white paper, the orange tint was ™ the spleen,
very evident without any test applied to it, particularly so,
when compared with a similar stain made by a section of
the liver, in which there was no such tinge.

In the stomach and duodenum, the rhubarb was found in stomach and
large quantities; but none was met with in the cecum. duodenum,

The urine was impregnated with rhubarb, the orange tint urine,
upon the application of the alkali being very distinct.

Atthe end of twenty hours, the serum of the splenic and scrum.

_vein had a tinge equal to four drops of the tincture of rhu-

barb in two ounces of alkaline water; that of the vein of

_the colon and vena cava was less distinct.

The effects of the infusion of rhubarb on the spleen, the Effectsslighter
serum of the blood, and the urine, corresponded exaétly with a 1 he
that of the tincture in the former experiments, but was in a
jess degree of intensity. .

In the course of these experiments, an attempt was made Quantity of

to ascertain whether the blood in the splenic vein has a AEBS a
parently

‘greater proportion of serum than in the other veins of the greater im

body, and the general results were in favour of such an !ood from
opinion; but it will appear, from what follows, that the es Mire
quautity of serum separated in tweuaty-four hours is by no Mtes in 24
means a juft criterion of the proportion, which the blood pirical cis
contains.
Experiment 1. Three ounces of blood from the arm of a Exp. 1.

“ healthy

108

Exp. 2.

Exp. 3,

Exp. 4.

Most serum
separates from
blood received
into a warm
vessel,

and flowing
freely.

Spleen in two
different states:

EXPERIMENTS ON THE SPLEEN.

healthy person were received into a graduated glass vessel,
previously cooled to the temperature of 32°, three more
into a second glass of the temperature of 50°, and three
into a third at 70°. ‘The three glasses were brought into a
room, the temperature of which varied from 40° to 50°. At
the end of nineteen hours, the serum was found in the fol-
lowing quantities.

In the glass at 32°. 9 drams.
5S ie a
70 10

The blood did not flow so freely into the glass at the
highest temperature, as nto the other two.
Exp. 2. This experiment was repeated, and the serum
examined at the end of forty-three hours.
In the glass at 32° 12 drams.
a0" 11g
70° 13
Exp. 3. It was repeated, and the serum examined at the
end of 67 hours.

In the glass at 32° 11 drams.
50° 11}
/ ean
Erp. 4, It was repeated, and the serum measured at the
end of ninety hours.
In the glass at 32°. 11} drams.
50° 13
70” 102 |

The blood did not flow so readily into the glass at the
highest temperature as into the other two.

From these experiments it appears, that the serum se- ©
parates in larger quantity, when the blood is received into a
vessel at the temperature of 70 degrees, than at 50° or 32°:
this, however, is prevented from taking place by the blood
not flowing readily from the vein.

From the experiments on the spleen contained in this and
the foregoing paper, the following facts appear to have been
ascertained. ,

That the spleen is met with in two very different states,
one

EXPERIMENTS ON THE SPLEEN. 109

one which may be termed the distended, and the other the
contracted; and that in the one its size ig double what it is

“in the other. In the distended state there is a distinct ap-

pearance of cells containing a limpid fluid, distinguishable

by the naked eye; in the contracted, these only become

distinct when seen through a magnifying glass. The dis- dedeudonsnon
tended state takes place when the stomach has received un- drinking.
usual quantities of liquids before the animal’s death; and

the contracted state, when the animal has been kept several

days without any drink before the spleen is examined.

That the trunk of the splenic vein (of the hog) is Splenic vein
more than five times the size of the trunk of the splenic Pani As
arge as the
urtery. artery.
That, when the pylorus is secured, coloured liquids pass Liquids pass
from the cardiac portion of the stomach into the circulation nae the car-
: , ; _, diac portion of
of the biood, and go off by the urine; and while this is the stomach
going on, the spleen is in its most distended state, and the © the spleen,
colouring matter is found in its juices, although it is not to
be detected in those of the liver. The colouring matter
cannot therefore be conveyed to the spleen through the
common absorbents of the stomach, which lead to the tho-
racic duct.

That, when the pylorus is open, the’colouring matter un-
der the circumstances above mentioned is equally detected

in the spleen.

That, when the spleen is in this state, the blood in the Colouring mat-
splenic vein has its serum more strongly impregnated with ee ag

the colouring matter, than that of the blood in the other splenic vein,
veins of the body; and when the stomach is kept without pi
liquids, although colouring matter is carried into the system liquid,

from the intestinal canal by the ordinary channels, no

-particular evidence of it is met with iu the spleen or its

veins. :

That the caecum and the portion of the colon imme= Bjiooq yescels
diately beyond it are found (in the ass) to be at all times occasionally
filled with liquids, even when none has been received into oceans
the stomach for several days, and there is a greater number the colon.
of absorbent vessels for carrying liquids from the colon into
the thoracic duct, than from any other part of the body.

The

110 | EXPERIMENTS ON THE SPLEEN.

The colon is therefore a reservoir, from’ which the blood
vessels are occasionally supplied with liquids.
Mr. Sewell informs me, that the same observation applies
in a still greater degree to the horse.
Liquids drunk, That coloured liquids taken into the human stomach, un-
arse at der some circumstances, begin to pass off by urine in seven-
minutes. teen ininutes, continue to do so for some hours, and then
disappear; they are again met with in the urine, after the
colouring matter is known to have arrived at the great m-
testines, by its passing off by the bowels,
From the above facts, the following conclusions may be
drawn. .
Liquids con- That the liquids received into the stomach, beyond what
pba os are employed for digestion, are not wholly carried out of it
spleen, by the common absorbents of the stomach, or the canal of
the intestines, but are partly conveyed through the medium
of the spleen into the circulation of the liver.
Thecommuni- |The vessels which cominunicate between the stomach and
ape he the spleen have not been discovered; but if it is proved,
vered, that the colouring matter of the contents of the stomach
is met with in greater quantity in the spleen, and in the vein
which goes from that organ to the liver, than in the other
veins of the body, there appears to be no other mode in whieh
it can arrive there, but by means of such vessels; and the
two different states of the spleen, which correspond with the
quantities of liquids that pass from the stomach, are strongly
in favour of the existence of such a channel.
Hence people This communication between the cardiac portion of the
ae hava stomach and the spleen will explain the circumstance of
the spleen and those, who are in the habit of drinking spirituous liquors,
liver diseased. faving the spleen and liver so frequently diseased, and the
diseases of both organs being of the same kind.
Thespleennot his organ is not essential to life, its office being of a se-
essential to life condary kind; but when it is materially diseased, or entirely
co Sa removed, digestion must be disturbed. The extent to which
tion, this takes place cannot be accurately known’ from expert=
ments on quadrupeds, and the instances in which the human
spleen has been removed have not been attended to with
sufficient accuracy, to afford an explanation of the effects

that were produced on the stomach.
V.

MACHINE FOR RAISING. COALS OR ORE. 111

Vv.

Account of an improved Machine for raising Coals, or other
Articles, fron Mines: by Mr. Gitzerr Gixpin, of Old
Park Iron Works, near Shifnal*.

SIR,

"Tue improvement of the machines in use for raising coal Experiments
and ore from the mines has long been a desideratum of the ee ee
Society for the Encouragement of Arts, Manufactures, and quired.
Commerce, and they have repeatedly offered a premium for
this purpose.
Those in general use (from the increased expense of horse Those in com:
labour), are worked by a steam engine, attached to a crank ™°"
of twenty-one inches radius, wedged on a shaft along with
a fly wheel, eleven or twelve feet in diameter, and pinion
wheel, of eleven teeth, which latter works in another of
sixty-four teeth, on the shaft of which is a plain cylindrical
barrel, from four to six feet diameter, and nine or ten feet
long. Some have barrels formed of frustums of cones, (the
perimeters of which are in the proportion of about five to
four), united at their bases, and of various diameters., The
axes of both kinds are placed at right angles with the cen-
tre line of the pit, and at each end a rope of six inches in
circumference is made fast by a staple, which ropes work
(in contrary directions at the same time) over two pulleys,
placed in a frame parallel to each other, and at an equal
distance from the centre of the pit; to the ends of these
ropes the baskets of coal and ore to be raised are hooked.
The simplicity of their general structure is such as, per- pan fee
haps, not to admit of any considerable improvement; but parrel,
the forms of the barrels are very defective.
On putting one of these machines in motion each rope
forms a triangle, the lines thereof from the pulley to the
first and last coil, and the surface of the barrel, forming its

* Trans. of the Society of Arts, vol. XXV, p. 74. Twenty guin as
were voted to Mr, Gilpin as a premium by the Society.
three

112 MACHINE FOR RAISING COALS OR ORE.

Cylindrical three sides. Upon the cylindrical barrel the load always
Fs ab tends, from gravitation, towards the nearest point of con-
tact with the centre of motion of the barrel, and, in gonse-
quence, the ascending rope at first bends around it in reced-
ing coils from the subtending side of the rectangle, dimi-
nishing their distances as they approach the nearest point of
contact, (where the rope crosses the cevtres of the pulley
and barrel at right angles), thereby leaving a great part of
the latter uncovered by the rope, and hence the necessity
of such long ones; afterward coiling hard against itself as
it approaches the other side of the triangle, to its great in-
jury in wear.
Conicalinim- The barrels formed of frustums of cones, united at their
proper propor- bases, the perimeters of which are in‘the proportion of
tions. . :
about five to four, are equally defective, on account of the
rope, for the reason before mentioned, binding hard against
itself, and even sometimes, (in wet weather, when its rigidity
is increased by absorption of water,) folding at first in re=
ceding coils, and afterward so hard against itself as to force
those receding coils to slip suddenly towards the small peri-
meter of the cone, thereby making a large portion of the
rope to descend the pit in an instant, breaking the rope by
Danger. the sudden jerk, and frequently causing the immediate de-
struction of the men who may be ascending the pit at the
time, or dashing to pieces the basket and its contents.
Disadvantages, Beside the unnecessary expense arising from the use of
hempen ropes, and the breakage of chains when applied in
the common way, the forms of the barrels are quite erro-
neous in principle. Some are cylindrical; others formed of
frustums of cones united at their bases, without any deter-
minate proportion in their pertmeters, or regard to the weight
of the rope or chain working thereon, both of which are ab-
solutely necessary to acquire a maximum effect.
Proper propor: The convex surface of a frustum of a cone is equal to
tions, the convex surface of a cylinder of the same altitude, hav=
ing its circumference equal to half the sum of the perime-
ters of the frustum: and circumferences of circles being to
one another as their diameters, the surface of a barrel
formed of two frustums of right cones (united at their
bases), each 64 inches diameter at one end, 32 at the other,
and

MACHINE FOR RAISING COALS OR ORE. 113

and 54 long, which is the size we have adopted here, is
equal to the surface of a plain cylindrical one, 48 inches
diameter, and 108 long. Each will therefore bend the same
length of cordage in a equal number of revolutions, and so
far they are equal to each other; but they vary very con-
siderably in the 120menta required to work them.

Let a = the weight of the basket of coal, and 6 = that of Oa ee
the descending part of the chain; then, on the cylindrical ger:
barrel, when the former is hooked to the end of the latter,
and eased from the bottom of the pit (the opposite chain
being bent on the barrel), @ + 6= the counterpoise re-
quired at 24 inches radius; and when it is wound up to the
top (the descending part of the opposite chain hanging
down the pit), a—6= the counterpoise required at the
same radius.

On the barrel formed of frustums of right cones, when and with two
the load is eased from the bottom of the pit, it and the “tums of

cones.
chain are suspended from one of the smaller perimeters

(the opposite chain being bent on the barrel), ~ + = as

the counterpoise required at 32 inches radius; and when it
is wound to the top of the pit, it is suspended from the
larger perimeter of one frustum, while the descending part
of the opposite chain is hanging down the pit from the smaller

-. b
perimeter of the other, and in that position a ae the

counterpoise required at the same radius.

Consequently, by supposing a, the weight of the basket This applied
of coal, to be 800lbs. and 0b, the weight of the descending mglciis
part of the chain, 400lbs. (these are the weights which we
have adopted here), we have the counterpoise required upon
the cylindrical barrel, at 24 inches radius, 1200lbs. when
the basket of coals is at the bottom of the pit, and 400lbs.
when it is at the top; but upon the barrel formed of frus-
tums of right cones, the counterpoise required at $2 inches
radius is 600!bs. in each position. And as the counterpoise
required is in inverse proportion to the length of the radius
at which it is applied, we have 24:32:: 600: 800lbs. the
counterpoise required upon the barrel formed of frustums

Vou. XXI—OctT. 1808. I of

x

114

Maximum of
effect.

Barrels,

Tron work,

Chains work-
ing in grooves
a recent prac-
tice,

MACHINE FOR RAISING COALS OR OR¥.

of right cones, at 24 inches radius. Again, as the descending
part of a chain + a basket of coal of double its weight, un-
bending out of equidistant grooves from the base of a frus-
tum of a right cone towards its smaller perimeter, balances
in every revolution of the barrel a chain of equal weight +
a basket of coal of double its weight, bending into equidis-
tant grooves from the smaller perimeter of a similar frustum
towards its base, the counterpoise required must be equal in
all parts of the descent.

So that by making the weight of the basket of coal to
that of the chain, and the perimeters of the frustums of
cones, which form the barrel, to each other in the propor-
tion of two to one, a-maximum is obtained, by which a bar=
rel of this description requires one third less momentum, (and
consequently one third less expense), to work it than a cylin-
drical one.

The barrels are made by nailing two or three inch planks
upon wooden or iron curves, as in the common way; and af-
terward folded spirally with wrought iron tire, so as to leave
a vacancy of about half an inch between each fold, for the
lower part of the ellipses of those links of the chain which
work vertically to move in, and keep the coils at an equal
distance from each other.

The wrought iron tire is of two kinds, the one for conical,
and the other for cylindrical barrels; the cross section of
that for the barrel formed of frustums of cones is nearly a
parallelogram 1% inch by ths; out of the upper part of
which about one fourth of an ellipsis is taken, to form a ho-
rizontal bearing for those links of the chain, which lie flat
upon the tire; the cross section of the latter is a rectangle,
1% inch by 22 inch. Both are rolled into their proper form,
and holes of a quarter of aninch diameter punched therein,
at a foot from each other, for the purpose of nailing them to
the planking of the barrels.

As the method of working chains in grooves has only been
in use about three years and a half, it is impossible to give
a certain idea in respect to their durability. In all that time
not a single link has broke, or the least accident occurred
therefrom, though Messrs. T. W. and B. Botfield, have
nearly three thousand feet in daily motion at this manufac-

tory.

MACHINE FOR RAISING COALS OR ORE. 115

tory. The wear has also been so trifling, that I conceive
they will sooner fail from oxidation than attrition: for al-
though the machines for raising coal and ore from the mines
are in use twelve hours in the day, the brown oxide of iron
formed upon the links by exposure to the atmosphere is sel-
dom disturbed by the motion of the chain,

The method of folding wooden barrels with wrought iron Cast iron bar
tire does away the necessity of cast iron ones, and may be tls unneces-
applied to every wooden barrel now in use at a small expense, ki
as may be seen by the estimate which is subjoined.

There are now at work in the mines of this manufactory
four machines, with wooden barrels folded with wrought
iron tire, one cylindrical, and three formed of frustums of
cones, raising upwards of eight hundred tons of coal and
iron ore per week from pits of about eighty yards deep; and _
three others ave in hand.

I look forward with confidence to the general substitution Chains used
of chains for hempen ropes at all our mines and manufac- instead of

‘ cae aie ae ., hempen ropes.
‘tories, a matter of importance to the British empire, as it
will considerabiy lessen the consumption of hemp, and ren-
der it more abundaut for the exigencies of the Navy.

Wishing to give this method of working chains all the
publicity in my power, I will obviate all apparent (for there
are no real) difficulties, which may occur to any person in
their application, on his stating them in a letter post paid
addressed to me here.

I am, Sir,

Your most obedient Servant,

GILBERT GILPIN.

_ Expense of tarred ropes for a machine for raising coal and Comparative .
ore from a pit eighty yards deep, for three years and four eed “as
months.

ON EEE 186 ble

Ten ropes each 110 yards long, 6 inches in cir- Reyes
cumference, and 5lbs. per yard, 5500\lbs. at
Sd. per lb+-sceccecccccccecsoserevesceccs 183 6 §

Deduct 10 worn out ropes 2750lbs, at 1d. Ibes 11 9 2

Net expense of ropes for 3 yearsand4.months £171 17 6
I2 Expense

“116 MACHINE FOR RAISING COALS OR ORE.

Expense of chains for a machine for raising coal and ore

from a pit eighty yards deep.

Chains. Two chains each 110 yards long, formed of 3

inch iron, 28 links to the yard, and weighing

5lbs. per yard, 1100lbs. at 6d. per Ib-----+-» 9710 0
180 yards of wrought iron tire, with the holes —

punched therein weighing 7lbs. per yard, at

1s. 6d. per yard -ecreceerevcccrscscccece 13 10 0
540 nails for the tire, 27lbs. at 6d. per Ib-«--+- 013 6
Workmanship, nailing the tire on the barrel, 180

yards at 22d. per yard-+-seesccceccccocees 117 6

——=

£43 11 O

The above chains and tire have been at work three years
and four months, and do not appear te be one fourth worn.

ee

Ropes retained Messrs. T. W. and B. Botfield annex a certificate, that
sae ao ati they have now at work at their mines four of Mr. Gilpin’s
men’s prejudi- machines, one with a cylindrical barrel, and three formed
ia of frustums of cones; which machines they conceive 'to be
superior to any hitherto known or in use, and producing
their effect at a much less expence. To this Mr. Gilpin
subjoins

You will please to observe, that of the four machines now
in use, two only work with two chains each, and they are
both formed of frustums of cones; the ether two, the one
with a cylindrical barrel, and the other a frustum of a cone,
have each a chain at one end, and a patent flat rope at the
other. We are induced to adopt the latter plan, to do away
by degrees the prejudices, which miners and colliers have
imbibed against chains, from accidents which they have
been witnesses to in the common way of working. Though
the causes of similar accidents are entirely done away by the
new method of working, some little of the old prejudice
remains; a thing not to be wondered at, when we consider
the uninformed state of this description of men, arising
from a life spent in the dark recesses of mines; and, as it

were, cut off from the rest of society.
From

MACHINE FOR RAISING COALS OR ORE. : 117

From the uniformity and safety of the new method, their These wearing
prejudices against chains are, however, rapidly wearing away, rine
and I have no doubt, that in a few years they will even be
preferred. It is certainly more reasonable to suppose, that
this will be the case, from the superiority which iron holds
in point of strength of materials, than that ropes even should
have been known, (at least in the mines,) had the new me-
thod of working chains been in use prior to the introduction

‘

of hemp.

Reference to the Engraving of Mr. Gilbert Gilpin’s im-
proved Machine for raising Coal, Ore, &c. Pl. 3, fig. 1,
2, 3, 4.

Fig. 1. a. A crank to which the connecting rod is fixed Explanation of
to attach the machine to the steam-engine saliich works it. the plate,

b. A wheel of 13 teeth, wedged about the same shaft with
the crank, and which works ‘tty the wheel d.

c. A fly wheel 11 feet in diameter, wedged upon the same
shaft as the wheel 0. ;

d. A wheel of 64 teeth, wedged upon the same shaft as
the barrel, into which the wheel 6 works.

e. A wooden barrel, formed of two frustums of cones
united base to base, and folded spirally with wrought iron
tire, which keeps the links of the chains at right angles with
each other, and with the grooves in the pulleys.

ff. The reeling-post and its lever, for disengaging the bar=
rel from the steam-engine, when the men are to be let
down into the pit by means of the break.

gg. A break wheel, break and lever, for regulating the
velocity of the barrel when disengaged from the steam en-=
gine, and in the act of lowering the miners into the pit.

hh, The frame on which the machine is erected.

ii. Fig, 2. The pit-frame, for supporting the pulleys,

__ k. The pit represented by a circle, part of which is shown
open, and part by dotted lines.

il. Two grooved pulleys, over which the chains, extend-
ing a considerable length from the barrel a work in parallel
lines,

m. The carriage (called a tacking in Shropshire) on which
the

118

On Fermat’s
proposition on
polygonal
numbers.

ON POLYGONAL NUMBERS.

the coal and ore are landed from the chain at the pit head,
moving on four small iron wheels.

nn. Baskets on which the coal and ore are raised from the
pits.

o. The hook which goes into the staple of the basket to
draw it forward when lowering on to tlie tacking.

After the basket is lowered, the tacking is drawn forward
by two girls to the edge of the frame, which is laid level
with the ground on its outside, and near to which the coal
and ore are loaded into waggons, and afterward drawn upon
iron rail-ways to the furnaces, forges, &c.

Fig. 3. A section of a part of the barrel and tire, show-
ing the manner the links of the chain lie on it, on a scale of
3 inches to the foot.

Fig. 4. A section of the pulley, with a link of the chain
lying im it.

In a large machine the barrel is fixed 24 or 25 yards from
the pit.

ih

Remarks on Mr. Goven’s Essay on Polygonal Numbers: by
P. Bartow, Esq.

To the Epitor of the PurLosopHicaL JOURNAL.
SIR,

In your number for July, the first article is an essay by
John Gough, Esq., in which he has attempted the demon-
stration of a very curious and general property of numbers;
but as it appears to want that perspicuity and simplicity,
which are the distinguishing beauty of mathematical rea-
soning, I have drawn together the following observations
upon it; which, if you think proper to insert them, will
give your readers an opportunity of judging of its merits,
more particularly than they may have hitherto done, It will

| : | | also

ON POLYGONAL NUMBERS. 119

a so.afford Mr. G. an opportunity of explaining the ambi- On Fermat’s

guous parts; and will at the same time much oblige proposition on
polygonal
Yours, &e. numbers,
Royal Mil. Academy, P. BARLOW.

Sept. 13, 1808.

The curious theorem, which Mr. Gough has undertaken
to demonstrate, was first announced by Fermat, in one of
his notes at page 180 of his edition of Diophautus; and the
demonstration for the particular case of squares was given
first by Lagrange, in the (Mém. de Berlin, 1770), and af-
terwards in a simpler form by Euler, in the (Acta Petrop,
Ann. 1777), as we are informed by le Gendre, in his Essai
sur la Theorie des Nombres, at page 202; where there is
also given a demonstration for the same particular case. Le
Gendre has likewise in another part extended it to triangu-
lar numbers, and this is the most that has ever been done
by any mathematician. If therefore the ingenious author
of the abovementioned essay has failed in his demonstration,
he has the satisfaction of having failed in an attempt, in
which many of the ablest mathematicians in Europe have
succeeded no better than himself; and if, on the contrary,
he can clear up those parts, which appear at present to be
defective, the greater degree of merit will be due to his in-
»genuity. and ability, of which I have always entertained the
highest opinion: and I feel confident, that he will not mis-
take my intentions in the following criticism, but rather at- |
tribute it to my love for mathematical truth, than to any
invidious desire of criticising his paper.

The first three propositions and their corollaries are in
themselves correct, although I am ata loss to see in what
manner they are intended to be applied to the general de-
monstration. The first part that I shall examine is the con-
clusion drawn at cor. 2, prop, 4, In cor. 1 of the same
prop. it is proved, that e, which is taken to represent any
ageregate of polygonals of the denomination m, is of the

form e=p+m—2.s; and then in cor. 2, having shown
that every natural. number is also of the same form, p +-

m—2.s, the_converse of the prop. is inferred to be true
likewise ;

120

On Fermat’s
proposition on
polygonal -
numbers.

ON POLYGONAL NUMBERS.

likewise; namely, that every number is the aggregate of
polygonals. Now it is easily seen, that this is false reason-
ing. Our author might, with as much propriety, have said,
that every natural number is either even or odd, and every
aggregate of polygonals being also either even or odd, there-
fore every natural number is the aggregate of polygonals:
or, to put it in a stronger light, every natural number 1s of

the form p+ m—2.s; and, every square number being

also of the form p + m— 2. s, therefore every natural num-
ber is a square number. No person can for a moment fail

- of detecting 1 in those two last cases the fallacy of this: rea-

soning, nor of perceiving the strict analogy it bears with
that made use of in the cor. abovementioned, It is to be
observed, that I do not object to the conclusion, but to the
manner of obtaining it; for all that is drawn from the first
four propositions and their corollaries might have been
granted at first as a postulate, if any use could have been
made of it in the general demonstration.

For unity is a polygon of every denomination, and every
natural number is composed of a number of units, there-
fore every natural number is composed of a number of po-
lygons of any denomination m, consequently every natural
number is either a polygon of a given denomination m, or
may be resolved into polygons of that denomination ; the
number of those polygons being unlimited, as in the carolina
alluded to.

The next place, where any conclusion is drawn, is in the
cor. to prop. 6, where it is said, that If e=y +t, can be
resolved into polygons, the number of which = m—/f,
e+ f may be resolved into m polygons of the same deno-
mination. Now either this supposition is necessary to com-
plete the demonstration, or it is not: if it is not necessary,
it ought to have been omitted; if it is necessary, it ought
to have been shown (but it no where is in the demon-
stration) that e—y+t may be resolved into m —S po-
lygons, because the conclusion depends upon this suppo-
sition, and if the supposition is ¢rwe, the conclusion is true;
on the contrary, if the supposition is false, the conclusion
must necessarily be so likewise. This language is at all
events too vague for mathematical reasoning. I am willing

to

ON POLYGONAL NUMBERS. 121

to allow that, if e can be resolved into m/f polygons, On Fermat's
: 4 . proposition on
e+ f may be resolved into m polygons; but if € cannot be 5), eonal
resolved into m—/ polygons, what proof have we, that numbers.
e+ / can be resolved into m polygons? And that there are
many such cases is evident: thus, 14cannot be resolved into
Jess than three or m triangular numbers, nor 23 into less
than four or m squares. :
This ought to be explained, the importance of the pro-
position demands it, the last labours of Euler, Lagrange,
and le Gendre demand it also, and a few more pages may
very well be afforded to complete the demonstration.
The remaining part of the essay goes on to show, how
any given number may be resolved into polygonal numbers
of any given denomination ; but, from the examples there
given, it does not appear to possess any advantage over the
usual method of trials; and even if it did, it is of no use
in demonstrating the proposition, for showing how a thing
is to be done is very different from showing it may always
be done.
Upon the whole therefore we may conclude, that for the
present, the celebrated theorem of Fermat is without a de-
monstration, and that its importance, as containing one of
the most curious properties of numbers, renders it worthy
the attention of mathematicians.

Vil.

Some farther Remarks on the Doctrines of Chance, in @ Let-
ter from a Correspondent.

SIR,

Hlavine observed a letter in the last number of your Certain doc-
valuable publication, from a correspondent who has assumed ae
the signature of Opsimath, in which some doubts are express- 2 farmer conte
ed respecting the elementary Doctrines of Chance, and a Spondent.
request to yourself, or any of your correspondents, either to

confute or to confirm his objections, I have ventured to offer

the following remarks; though certainly with some diffidence,

being

499

‘The case ob-
jected to,

Attempt to de-
fend it.

The areument

pursued,

REMARKS ON THE DOCTRINES OF CHANCEs.

being apprehensive from your having declined favouring us
with your remarks, that your view of the subject might not
be very dissimilar to your correspondent’s.

Opsimath admits de Moivre’s first case, viz. that if any
one were to undertake to throw an ace in one throw with one
die, he would have 1 of all the possible chances in his fa-
vour, and the remaining ¢ against him: but objects to the
second case, viz. that, if he were to undertake to do it in
two throws with one die (or, which is certainly the same
thing, in one throw with 2 dice) that the chances in his fa-
vour are 44 and 34 against it; alleging as a reason, that two
equal chances are twice as good as one, and that of course
it should be 42 instead of 34. This reasoning is correct if
the chances are of equal value: but this I apprehend is not
the case, the second chance being less than the first by the
probability of the first’s succeeding; and as a confirmation
of de Moivre’s doctrine being correct, it appears by the fol-
lowing statement, that of alk the 36 possible combinations
with 2 dice, there are but 11 throws which give an ace or
any other particular number. Let 1 die be called A, the
ether B; then may be thrown with

AB AB A B AB: A’B.oA OR
a oa | ee | ao’ 5 ht 6 1
1 2 2 2 3.2 AQ se 8 6 2
os 2 8 38 a3 5, 8S 6 48
144 2:4 3.4 4 4 - 6-4
iS Q2 5 EN 4 5 Si N85 6 5
1 6 2 6 3 6 a G 5. 6 6 6

and again, as the chance of throwing an ace with one die is
admitted by your correspondent to be 4, and of not doing
it £, the chance of not doing it with either of two dice is
&x% %= 44, and this subtracted from unity, which repre-
sents the certainty of an ace being either thrown or not
thrown, gives 44 as above.

Opsimath farther objects to this statement, and says, if
we proceed according to the above method, the probability
of throwing an ace with one die in 6 throws does not amount
to 2, or a certainty. Nor should it: for were this the case,
he might undertake to pay any sum, provided he did not

. da

REMARKS ON THE DOCTRINES OF CHANCE.

do it in 6 throws with 1 die, or in 1 throw with 6 dice, which
i think he would be very unwilling to do. The fact is, that
out of the 46656 possibie combinations with 6 dice, there
are only 31031 throws that produce an ace, or any other
particular number; which, if he will take the trouble, he
may convince himself of, by trying all the combinations, as
in the preceding statement of the 2 dice, or according to the
method before given, viz.

Probability of not throwing an ace

BURT MMMACI@ Sa. 0100,6, c.ctee ein 9 9.0.06 ¢ 00 & of doing it 3.
with 2 dice 2x45 $2 cevceees aL
with 3 dice £x4x4= TLS eeevecee iO.
with 4 dice 2x2xX2xX4= Pees cetteees | sO7IR
with 5 dice Ks Xexexix BYES seeecees £651.
with 6 dice 2X EX EX EXSK FHA coeeeeee S10gL

123

With respect to throwing a head with a halfpenny in 2 Similarreasone

throws (or with 2 halfpence in 1 throw, being the same
thing) it ought, according to his view of the subject, if I
understand him right, to amount to a certainty; as there
are but two ways in which a halfpenny can be thrown, and
there being two halfpence to do it with. He appears how-
ever to be satisfied with de Moivre’s value of the chance,
viz. 3, which is the true one, for in the 4 ways in which 2
halfpence may be thrown, there are only 3 which give a
head; for with the first
may be thrown a head, and with the second a head,
WCAG, sinless os oteyetata eis wha ea es tail,
tail, se ccetecseeseseees head,
tg] sh seine aioe Ui in old. diece’ otaake

I am, Sir,
Your constant reader,
and most obedient servant,

B. H.
140, Millman Street, Bedford Row,

14 Sept, 1808,

REMARK.

ing applied to
two halfpence.

194 SECURE SAILING OR LIFE BOAT,

REMARK.

The mistake B. H. appears to be led into an errour by supposing, that
eae the chances for throwing an ace in six throws of one die and
several throws 81x throws of another, are’the same thing with the chance of
5 lapedntpleg throwing an ace in six throws of two dice; but this is not
several dice, the fact. Six throws of one die and six throws of another
are clearly equal to twelve throws of one die, and this
chance I apprehend will not be denied to be equal to two.
In throwing two dice thirty-six times, it appears by the ta-,
ble of B. H, himself, which is perfectly accurate, that the
thrower may calculate upon throwing twelve aces, as he
might by throwing one die seventy-two times: but here is
the difference; in throwing one die seventy-two times, he
has a right to reckon on an ace being turned up in twelve
of the throws; in throwing the two dice thirty-six times
however, he can reckon on no more than eleven throws in
which an ace will be turned up, because im one of the
throws two aces will come together, and consequently one
will be lost, which evidently cannot be the case when the
two dice are thrown in succession.
With regard to the throws of a halfpenny the reasoning is
precisely the same ; nor does Opsimath appear more inclined
to acquiesce in the assertion, that the chance of throwing a
head with one halfpenny in two throws is only 3: though he
would probably allow this to be the true value of the chance
of throwing a head at one throw with two halfpence. C,

VIL.

Description of a secure Sailing Boat, or Life Boat. By
Mr. CuristopHeR Witxson, Richard Street, Commercial

Road*.

SIR,
aa built Herewirn you will receive drawings of a neutral
pee built self-balanced boat, with an explanation, which I re-

* Trans. of Soc. of Aits, vol XXV, p. 55. The gold medal was

voted to Mr. Wilson for this invention.
quest

SECURE SAILING OR LIFE BOAT, 125

quest you will have the goodness to lay before the Society
for the Encouragement of Arts, &c., for their inspection
and approbation. I have made the explanation as clear as
Ican. Its construction will obviate the danger of its being Its advantages.
overset by persons crowding on one side, in getting in or out

of the boat; it will facilitate the landing of men on shore or

in boarding ships, and will cary a much greater press of
sail without danger.

As to the building part, I think that may be easily un-
derstood. My boat was made by men that had never before
seen a boat built, and I flatter myself the Society will ap-
prove of it.

T am, Sir,
Your most obedient humble servant,

CHRISTOPHER WILSON.

An Explanation of the Engravings of ihe neutral-built self-
balanced Boat.

By the term neutral is meant, what is neither of the two Method of its |
present modes now in use, i. e. clincher and carvel, but both Copstuction.
united, viz. clincher in the inside and carvel on the outside,
which neutralizes both the two into a third; and as every
thing has a distinguishing name, I have taken the liberty
to present it to the public, under the name of a neutral
boat.

The two modes of clincher and carvel-built have each
their separate advantages and disadvantages in regard to each.
other.

I shall begin with the clincher first. As the sides of the Advanteges of
planks are firmly fastened to each other, by lapping over clincher build-
and rivetting, they are much stronger than if the edges only tne:
butted ; and they have the property of being made tight
without caulking, only in the huddings and keel seams, and
are much lighter than carvel-built boats, and more adapted
for many uses; besides saving the difference between thick
and thin plank. But they have their disadvantages also ; qt; disadvan-
in the first place, both unfair sides and unfair water lines, tages.
which makes them hable to be injured by other bodies they

come

126

Advantages of
carvel huildiag.

Its dicadvan-
tages.

Neutral build-

ing.

SECURE SATLING OR LIFE BOAT.

come in contact with, and have the edges of the planks
broke so as to make a leak*, -which would not happen to
a smooth-sided boat, neither can the uneven side move so
well through the water, on account of its various resist-
ancest. They have also this disadvantage, that if damaged,
they require the skill of a professional workman to repair
them. :

The carvel built boats have the advantage of having
smooth sides and fair water lines, together with having the
planks of an equal thickness all over the boat, which makes
them less liable to receive injuries when meeting with other
bodies, and more adapted to move in the water, by their
fair sides and fair water lines. They are also more readily
repaired: if a professional boat-builder is not at hand, it
can be done by a common shipwright, or any workman that:
is used to wood work. 7

But they have also their disadvantages; in the first in-
stance they are under the necessity of being built of plank
of a great thickness to stand caulking; at the same time
they require larger timbers, which makes them heavy and
unfit for many uses, and also a great consumption of timber
en account of the thickness of the plank necessary. They
are also more subject to leaks from various causes than
clincher-built boats.

We will now look to the neutral system, and see if both
their advantages are not united, and both the disadvantages
got clear of.

Pl. IV, fig. 2, shows the section of the fore part of a
boat. The longitudinal slips are represented lighter colour-
ed, and placed over the joints where the edges of the planks
meet; they must be rivetted on to each adjoining plank,
near the edge, in the same manner as clincher-built vessels,
with a sufficient quantity of blair, made of tar and flocks,
such as is 1n common use in the north of England, (or any

* In the next paragraph but one carvel built boats are said to be more
subject toleaks. C.
++ This does not appear to be the fact. Clincher built vessels are so
superior to others in sailing, that, by an act of parliament passed many
years ago for the prevention of smuggling, they were declared illegal be-
yend eertain dimensions. C,
other

SECURE SAILING OR LIFE BOAT. 197

other caulking), between the slips and pianks, which will
always keep them tight, as long as the boat remains un-
staved, or the planks not worn through. These slips, each
being rivetted to the two adjoining edges of the planks, as
shown in Fig. 4, will make the joint as strong as the joint
of a common clincher-built boat, and as tight, without the .
risk of any external damage. These joints have also this
advantage, that the planks will not have their sides bevelled
off, but be of an equal thickness from edge to edge, which is
not the case in clincher-built vessels, for at the ends they
are half bevelled away, so as not to bear clenching. By
the neutral system two inches in the breadth of each plank
will be saved in the laps, which may be considerable in the
conversion of plank. I set little value on the slips, as there
is always a sufficiency of waste in cutting the planks to a
proper form.
A boat of this construction has all the strength of one
clincher-built, and can be made as light or lighter. It is
free from the disadvantages of irregular outsides, and from
the difficulty of repairing, which in this can be performed
by any common workman in wood, as I have found by ex-
perience. A boat built this way has a fair and smooth out-
side, it has all the advantages of a carvel-built one, at the
same time it is clear of the disadvantages of being loaded
with unnecessary wood, which makes the carvel-work very
heavy, the liability of leaks, and frequent want of caulking.
There is one evil, which both carvel and clincher built Common de-
boats have in common, that of having keel seams, and a ai above as
eel remediede
vacancy between the sand or garboard streak, and the upper
_ part of the keel, which soon gets filled with dirt, and re-
_ mains so, which naturally retains moisture, and speedily
- rots the wood. In this mode that evil is removed, by hay-
ing the midship plank bolted on to the keel, wide enough
to come over each side of the keel to clinch the slips on,
this not only removes the evil, but saves a great deal of
trouble in making the rabbets in the keel, and various be-
vellings in the sand streaks, which must be done by a good
workman. |
These boats require no larger timbers than common
clincher built boats, as the timbers need no greater notches,
but

128

Applicable to
boats, barges,
&e.

SECURE SAILING OR. LIFE BOAT.

but with this difference, that these timbers will catch the
slips that are rivetted over the joints of the planks each way,
and so the timbers and slips will brace one another, and add
an additional strength; but in the clincher built boats, the
timbers catch the laps of the seams only one way, and con-
sequently form no brace whatever.

All I need to-explain farther on the neutral system is its
application, It can be applied to all open boats, of what-
ever form or use, to all coal and other barges, lighters, er °
any vessels used in rivers or canals, and also to all large

cutters and luggers, which are now clincher built.

Explanation of Pl. IV, fig. 1, 2, 3, 4.

Explanation of | Fig. 1, is a bird’s eye view of the boat, showing the pro-

the plate.

jecting balance bodies, or hollow sides a 6, one of which, a,
is left open to show the partitions, which are placed oppo-
site to each timber, and are water tight; by this means, if
one or more should be broken, the rest would keep the ves-
sel buoyant. These partitions gradually lessen towards each.
end, where the planks unite, so as to make a similar ap-
pearance to any other boat when in the water.

Fig. 2, shows the depth and form of the cells or hollows,
as they appear in a section of the boat; also the manner in
which the slips are placed over the joinings, or seams of the
planks. .

Fig. 3, is a perspective view of the boat, in which @ b
show the projecting balance bodies, or hollow sides, which.
would render the boat buoyant if her bottom was staved in.
c, the lower part or body of the boat, from which the pro-
jections commence; d, the keel.

Fig. 4, shows the manner in which the planks or timbers
of the boat are united; ef, are two planks of the boat; g,
the slip of wood placed over them, and secured to them by
the rivets AA.

The section (Fig. 2), will best explain the nature and
utility of the self-balanced boat. The balance bodies form
two separate holds, to put any thing in, such. as provision,
arms, &c., which are wanted to be kept dry, having locker
lids, to open at the top of the different partitions in the
holds, as fancy or utility may require; or part of them

may

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SECURE SAILING OR LIFE BOAT. 129

may be filled with cork shavings, and by that means, if
the boat should happen to fill by any accident, she cannot
sink. ‘

In the boat I have altered for Government, the balance Boats altered

bodies (if the interior of the boat was filled with water) paisiae
would exclude as much water, between the inside of the
boat and the outside, as is equal to a body of water of 1 tun,
17 cwt, 2qrs, which is a great deal more than the weight of
men that will go in her, consequently they can run no risk
whatever of being drowned; and even if she had a hole
through her bottom, she would always keep a sufficient
height out of the water either for rowing or sailing.

But the main object is to make her sail and row much
faster than other boats, and both on calculation and trial my
boat will be found to sail much faster, aad with much less
danger than other boats.

I now come to the advantage of rowing.—As the balance Advantage of
sides project a foot beyond the resisting part in the water, pal *
there is that leverage on the boat (over a common one), and ; ;
also the same in the length of the loom of the oar, that
is in the inside from the gunwale of the boat, which allows
the whole of the oar to be lengthened, and by that means
it describes a larger circle in the water, and makes a longer
pull: the oars for the Government boat I have made are
lengthened from 14 to 18 feet.

The experiment of having two spars fixed at a distance This may be
from a boat’s gunwale, and the oars to work from them, *#ected by
has often been tried and found to answer, but this has a oe a
great advantage over that method.

| There is another advantage or property which this boat Will not roll,
has, she cannot roll at sea, but always keeps a levei position ay rene
aé far as the surface of the sea will allow; she may heel but
not roll, as the balances are always ready to catch either
way, and the opposite one assists the other by its weight out —
of water and gravitation; neither can this boat pitch like
another, for the balance bodies being out of the water, and
the breadth of six feet only m the water, it can only act
witha gravity on the water, equal to a boat of the weight
of six feet but as the resistance of the water upwards equal
to a boat of eight feet wide.
Vou. XXI—Ocr. 1808, K Or

ad

130

Two separate
improvements
of different ape
plication.

Opinions of the
advantages of
this mode.

SECURE SAILING OR LIFE BOAT.

Or 1 may make this mechanical simile: Suppose a work-
man uses a chissel to smooth a surface of wood, by laying
too great a stress on the tool it will go too far into the wood
for him to force it along in the direction wanted, but put
that chissel into a stock like a plane-stock, and set it to the
depth required, then the stock will prevent its going too far
in, and he can work easily though the plane be pressed on
ever so hard. A view of the engraving will elucidate this
comparison, as the balance bodies he parallel with the sur-
face of the water lengthways. The national importance of
such boats 1 leave to the public to decide. I must here ob-
serve, that my plan contains two distinct aud separate im-
provements, viz. my neutral mode of building, and the
application of the balance bodies.

The first improvement relates to the building of boats,
barges, &c., in general. The second is only partial, and
applicable to boats of peculiar descriptions or uses; that is,
all such as are wanted for dispatch, safety, or pleasure, or
occasionally for life boats: as there can be no question of
the self-balanced boats, built upon my plan, rowing and
sailing faster than other boats, and they may be used to go
to sea when others cannot; but the application of tne ba-
lance bodies is not meant as a general one, as it is not fit
for vessels of burden that are sometimes light, and at others
heavy laden, when the difference of the draught of water is
considerable.

CHRISTOPHER WILSON.
ae

CrERTIFICATE.—W) e whose names are hereunto subscribed
have examined the boat building on Mr. Wilson’s plan,
(which he calls the neutral plan) and are of opinion, that it
will be attended with many advantages.

The boats can be built as light as those that are clincher
built, preserving a smooth surface, and will not require
caulking; and they can be easily repaired by any carpen- .
tent oe

The advantage this boat possesses by having air gunwales
are obvious, and from the partial trial we have had of the
boat’s sailing which he has altered, we are of opinion, that

. his

SECURE SAILING OR LIFE BOAT. 131

his improvement in the keel and formation of the boat’s bot-
tom will give her greater stability than other boats of: the
same dimensions, with the properties of sailing well and
drawing very little water. -

MALCOLM COWAN, R.N.

JAMES NICOLSON, R.N.
ES
GENTLEMEN,

PERMIT me to present my thanks and acknowledg-
ments for the truly polite and distinguished manner in which
(though a stranger) you have permitted me to visit your
Committee ; the Society of which the same is formed I hold
in the highest estimation, and have deeply to regret the dis»

tance, that prevents my offering myself a candidate for a
seat among you.
The last time I had the honour of attending your Com-
mittee, Mr. Wilson’s new life boat became the subject of
discussion, the operation of which you did me the .honour
of requesting me t acquaint you of as soon as an opportu-
nity presented itself for a fair trial of her at sea.
About three o’clock in the afternoon of Friday last, the Trial of the
tide being about quarter flood, and the wind at south-west, wage at ade
blowing excessively hard, an object was discovered in the .
offing at about two leagues distance, bearing from the piers
of Newhaven W.S. W., which had the appearance of a
vessel waterlogged, and with only her foremast standing.
This induced Mr, Thomas Tasker (the person whom I ap-
pointed master of the boat, and which I have named the
Adeline) with seven others, to put to sea, with a view of
_ rendering assistance to the supposed distressed vessel, and
: although the breakers were tremendous, and the sea with
out them running very high, the boat under the manage-
ment of the crew beforementioned, ranged as coxswain, six
sitters, and a bowman, went out of the harbour in a very
lively style, and soon came up with the object in pursuit,
which proved to be a beacon, or lighthouse, of a singular
construction, triangularly built, and clench-board covered,
in its floating case, with a mast rigged out in the centre of
, K 2 one

132

Mr. Great-
head’s boats
much inferior.

SECURE SAILING OR LIFE BOAT.

one of the sides, and supposed to have broken adrift -from
the enemy’s coast by the boisterous weather: finding its
magnitude too vast for their strength to tow, and the even-
ing approaching, they returned. Numbers of persons were
assembled on the piers to witness the action, power, and
performance of the boat, who were highly pleased and gra-
tified. I was not present myself, but the next merning one
of the crew was sent to me from Newhaven to this place,
who stated, that. the whole of them were so fully satisfied
with the safety and superior powers of the boat, that they
shall not be afraid to put to sea in any weather, when the
distresses of their fellow creatures claim their exertions and
assistance. They particularly observed, she, with the six
oars manned, pulled extremely light and easy through the
water, and that though the breakers they pulled through,
and the heavy seas they rode over were awful, she did not
ship ten gallons of water the whole trip, neither were the
men wet on the seats. We have now at Newhaven one of
Mr. Greathead’s boats, provided by subscription, but from
the difficulty of getting her to sea, and her weight and con
struct’oa rendering it almost impossible te pull her through
the broken water, it is very improbable she will ever be
used.

My opinion is, that Mr. Wilson’s boat will answer. Its

cost I conceive will exceed £150, including the building

and fitting her out.
T have the honour to subscribe myself with the greatest
respect,
Gentlemen,
Your obliged and most
obedient humble servant,

WILLIAM BALCOMBE LANGRIDGE.

P.S. I should have observed, that the crew pulled her
stern on at every sea, and that such water, as in general fills
over the bow of ordinary boats, is received by the fore part
of her flammings, or floor of extended sides, and sent or
dispersed sideways.

€

1:

IMFROVED CAPSTAN AND WINDLASS. 133

IX.

Description of a Capstan, that works without requiring the
Messenger or Cable cotled round it to be ever furged. By
Jd. Wititey Boswe.t, Esgq., of Clifford’s Inn*.

SIR,

I Request you will lay before the Society of Arts, &c. the pass Pea

model of a capstan contrived by me, which works without guire the mes
requiring the messenger or cable coiled round it to be ever senger or cable
surged, an operation necessary with common capstans, which One Saag
is always attended with delay, and frequently with danger.

Capstans of this kind can be made by a common ship-
wright, and would not be liable to be put out of order.
They also would not occasion any additional friction or wear
to the messenger or cable, in which particulars they would be
superior to the other contrivance hitherto brought forward
for the same purpose; they also would much_ facilitate the
holding on.

The great loss of time and great trouble, which always Reasons for not
attend applications to the Navy Board, prevent my» attempt- tet Bes ~
ing to bring the matter before the public through ‘hat chan-
nel, though I have had the most unequivocal approva‘ion of
the capstan from the two gentlemen of that board best
qualified to judge of it. T mention this, least it aight be
thought, that my not applying there first was from any
doubt of the goodness of the invention. If the Society
should approve of the capstan, I will draw up a more minute
account of it for publication.

I am, Sir,
Your very humble servant,

J. W. BOSWELL.

SiR,
I Have examined your model of a capstan, which is cal- Opinions ree

culated to prevent the surging of the messenger when heav- specting its
merit.
* Trans of Soc. of Arts, vol. XXV, p, 65, For this invention the gold

medal was voted to Mr, Boswell.

ing

134

No friction
between the
turns of the
cable or mes-
senger.

IMPROVED CAPSTAN AND WINDLASS.
ing in the cable, it certainly possesses great merit, and the
idea to me is quite new.
T am, Sir,
Your humble servant,
WILLIAM RULE.

Somerset-place, November 19, 1806,
-To Mr. BoswE.u.

eee SE ae
SIR,

According to your desire, I transcribe the part of the let-
ter from Mr. Peake (Surveyor of the Navy) to me, which
relates to the capstan laid before the Society.

Extract of a Leiter from Henry Peake, Esq.

<* With regard to your ideas on the capstan; I have tried
* all I can to find some objection to it, but confess I
‘© hitherto have been foiled, and shall more readily forward
*¢ it, if it was only to supersede a plan now creeping into’
“‘ the service, more expensive, and much worse than one
“ Jately exploded.”

As you and the members of the Committee have seen the
letter, | imagine further attestation needless relative to it.

I request you will mention, that all friction of the revolu-
tions of the cable (or messenger) in passimg each other be-
tween the barrels of the capstan, must be effectually pre-
vented by the whole thickness of one of the rings that passes
betwixt each crossing. J add this because one of the gen-
tlemen of the Committee wished to be informed on this
point.

Iam, Sir,
Your very respectful humble servant,

J.W. BOSWELL.

SIR,
In obedience to your intimation, that a written explana-

tion of the advantages to be obtained by the use of capstans
made

IMPROVED CAPSFAN AND WINDLASS. 135

made according to the model, which I laid before the So-
ciety for the Encouragement of Arts, &c., would be accept-
able, I send the following, which I hope will make the sub-
ject sufficiently clear.

As few but mariners understand the manner in which Method of

cables are hauled aboard in large ships, it will probably ren- eee
der the object of my- capstan more manifest, to give some‘a ship,
account of this operation.—Cables above a certain diameter
are too inflexible, to adnit of being coiled round a capstan ;
in ships where cables of so large dimensions are necessary,
a smaller cable is employed for this purpose, which is called
the messenger, the two ends of which are made fast together
so as to form an endless rope, which, as the capstan is turned
about, revolves round it in unceasing succession, passing on
its course to the head of the ship, and again returning to the
capstan. To this returning part of the messenger, the great
cable is made fast by a number of small ropes, called nip-
pers, placed at regular intervals; these nippersare applied,
as the cable enters the hawse hole, and are again removed as
it approaches the capstan, after which it 1s lowered into the
cable tier.

The messenger, or any other rope coiled round the cap- Necessity of
stan, must descend a space at every revolution, equal to the 5™8ins-
diameter of the rope or cable used ; this circunistance brings:
the coils in a few turns to the bottom of the capstan, when it
can no longer be turned round, till the coils are loosened and
raised up to its other extremity, after which the motion pro-
ceeds as before. This operation of shifting the place of the
coils of the messenger on the capstan is called surging the
messenger: It always causes considerable delay ; and when Causes delay
the messenger chances to slip in changing its position, which 2%¢ (@78er
sometimes happens, no smal! danger 1s incurred by those who
are employed about the capstan,

The first method that i know of, used to prevent the ne- First attempt
cessity of surging, was by placing a horizontal roller be- eae,
neath the messenger, where it first entered on the capstan,
so supported by a frame, in which it turned on gudgeons,
that the messenger in passing over it was compelled to force
upwards all the coils above the capstan, as it formed a new
coil. ie

This

136

Disadvantages.

Second at-
tempt.
]

IMPROVED CAPSTAN AND WINDLASS.

This violent forcing of the coils upwards along the barrel
of the capstan not only adds considerably to the labour in
turning the capstan, but from the great friction which the
messenger must suffer in the operation, while pressed so hard
against the capstan, (as it must be by the weight of the an-
chor and strain of the men,) could not but cause a very great
wear and injury to the messenger, or other cable wound round
the capstan; and that this wear must occasion an expense of
no small amount, must be manifest on considering the large
sums which the smailest cables used for this purpose cost.

The next method applied to prevent surging was that for
which Mr, Plucknet obtained a patent, the specification of
which may be seen in the Repertory of Arts, No. 46. In
this way a number of upright puppets or lifters, placed round
the capstan, were made to rise In succession, as the capstan
turned round, by a circular inclined plane placed beneath
them, over which their lower extremities moved on friction
wheels; and these puppets, as they rose, forced upwards the
coils of the messenger on the barrel of the capstan.

_ Thissomething This was a superior method to the first, as the operation

better,

Third at-
- tempt.

Friction as
great, and at-
tenued with a
new invonye-
~ nieuce.

of forcing upward the coils was performed more gradually
by it; but still the wear of the messenger from the lateral
friction in rising against the whelps of the capstan remained
undiminished.

The third method used for the same purpose was that pro-
posed by captain Hamilton. It consisted in giving the cap-
stan a conical shape, with an angle so obtuse, that the strain
of the messenger forced the coils te ascend along the sloped
sides of the barrel. The roller first mentioned was some-
times used with this capstan, of which a full account is in-
seried in the Repertory of Arts, vol. 2.

The lateral friction, and wear of the messenger against the
whelvs of the capstan, are equally great in this method as in
the others; and it, besides, has the inconvenience of causing
the coils to become loose as they ascend; for as the upper
part of the barrel is near a third less in diameter than the
lower part, the round of the messenger, that tightly embraced
the lower part, must exceed the circumference of the upper
extremity in the same proportion.

Advantages of In the method of preventing the necessity of surging,

which

ee |

AS wer.

IMPROVED CAPSTAN AND WINDLASS.. 137

which the model I have had the honour of laying before the jhe method
Society represents, none of the lateral friction of the messen- "OW proposed.
ger or cable agaiust the whelps of the capstan, (which all
the other methods of eiiecting the same purpose before men-
tioned labour under,) can possibiy take place, and of course
the wear of the messenger occasioned thereby will be entirely
avoided in it, while it performs its purpose more smoothly,
equally, and with a less moving power than any of them.

My method of preventing the necessity of surging con-
sists in the simple addition of a secund smaller barrei or cap-
stan of less dimensions to the large one; beside which it 1s to
be placed in a similar manner, and which need not in general
exceed the size of a half-barrel cask. The coils of the mes-
senger are to be passed alternately round the large capstan
and this small barrel, but with their direction reversed on the
different barrels, so that they may cross each other in the in-
terval between the barrels, ia order that they may have the
more extensive contact with, and better gripe ow each barrel.
To keep the coils distinct, and prevent their touching each
other in passing from one barrel to the other, projecting
rings are fastened round each barrel, at a distance from each
other equal to ebout two diameters of the messenger and the
_ thickness of the ring. These rings should be so fixed on the
two barrels, that those on one barrel should be exactly op-
posite the middle of the intervals between those on the other
barrel: and this is the only circumstance, which requires
any particular attention in the construction of this capstan.
The rings should project about as much as the cable or mes-
senger from the barrels, which may be formed with whelps,

This describede

and in every other respect, not before mentioned, in the
usual manner for capstan barrels, only that I would’ recom-
mend the whelps to be formed withowt any inclination in-
wards at the top, but to stand upright all round, so as to form
the body of the capstan in the shape of a polygonal prism, if
-the intervals between the whelps are filled up, in order that
the coils may have equal tension at the top and at the bot-
tom of the barrels, and that the defect which conical barrels
‘cause in this respect may be avoided.

’ The small barrel should be furnished with falling palls as
well as the large one; a fixed iron spindle ascending froin
the

138

How lateral
friction is pre-
‘vented, -

May be used

for a small ca-
ble without a
messengers

Applicable to
windlasses.

Farther advan-
tage stated,

e

IMPROVED CAPSTAN AND WINDLASS.

the deck will be the best for it, as it will take up less room.
This spindle may be secured below the deck, so as to bear any
strain, as the small barrel need not be much above half the
height of the large barrel; the capstan bars can easily pass
over it in heaying_ round, when it is thought fit to use cap-
stan bars on the same deck with the small barrel. As two
turns of the messenger round both barrels will be at least
equivalent to three turns round the common capstan, it will
hardly ever be necessary to use more than four turns round
the two barrels.

The circumstance which prevents the lateral friction of
the messenger in my double capstan is, that in it each coil
is kept distinct from the rest, and must pass on to the second
barrel, before 1t can gain the next elevation on the first, by
which no one coil can have any influence in raising or de-
pressing another; and what each separate coil descends ina
single revolution, it regains as much as is necessary in its
passage between the barrels, where in the air, and free from
all contact with any part of the apparatus, it attains higher
elevation without a possibility of friction or wear,

I have described my double capstan, as it is to be used in
large vessels, where messengers are necessary, from the great
size of the cables; but it is obvious that it 1s equally appli-
cable in smaller vessels, as their cables can be managed with
it in the same manner as is directed for the messenger. The
same principle may also be easily applied to windlasses, by
having a sinall horizontal barrel placed parallel to the body
of the windlass, and having both fitted with rings, in the
same way as the capstan already described. The proper
place for the small horizontal barrel is forward, just before
the windlass, and as much below its level as circumstances
will admit; it should be furnished with catch-palls as well
as the windlass.

Beside the advantages already stated, my ee im-
provement to the capstan has others of considerable utility.
Its construction is so very simple, that it is no more liable to
derangement or injury than the capstan itself. Its cost can
be but small, and every part of it can be made by a come
mon ship car penter, and be repaired by hiia at seaif damaged
by shot. It will take up but little room, ‘only that of a ioe

barrel

ON THE BODIES TERMED SIMPLE. ] 39

[ems

barrel cask; and it is of a nature so analogous to that kind
of machinery, to which sailors are accustomed, that 1t can
be readily understood and managed by them.

In order to render the description of my double capstan
more clear, I annex a sketch of it, as fitted up in the man-
ner proposed.

Tam, Sir,
Your very respectful humble servant,

J. WITLEY BOSWELL.

Reference to the Engraving of Mr. Boswell’s improved

Capstan, to prevent the necessity of surging. Plate 4,

Fig. 5.

A Represents the larger or common capstan used-on board Explanation of
ships. the plate. p

B Another capstan of less dimensions, placed in a similar
manner.

C The coils of the messenger passing alternately round
the large and small capstans, but with their direction re-
versed on the different barrels, so that they may cross each
other in the interval between them.

DDD D Projecting rings round each capstan or barrel,
so fixed on the two barrels, that those on one barrel should
be exactly opposite’ the middle of the intervals between
those on the other barrel.

X.

Leiter: from Dr. BEDDOES on certain Points of History, re-
lative to the Component Parts of the Alkalis, with observa-
tions relating to the Composition of the Bodies termed
Simple.

To Mr. NICHOLSON,
Dear Sir,

I Never regarded the base of the alkalis as belonging to Alkalis not

5 ve . : supposed b
the metallic order of combustibles, or projected their re- Dee ike

duction

{40
metallic,
though sub-
Stanees satura.
ted with oxi-
gen.

Arranged with
certain earths
as a distinct
class of bodies,
Query respect-
ing them.

Analysis of
bodies termed
simple sug-
gested.
Klectricity
jong consider-
ed as. the pro-
per mean.

The fusible
combustibles

proper for this.

Tried by Mr,
Davy,

A gas libera-
ted, and again
absorbed. ,

Metals and
other combus
tibles may be

ON THE BODIES TERMED SIMPLE.

duction by galvanism or electricity. But long ago, on con=.
templating all other substances in opposition to oxigen it
very naturally occurred, that, since alkalis and earths would
not burn or absorb oxigen, they might be already saturated
with it. This investigation, caused by Tondi’s paper, would
have been, had it operated at all, a’discouragement to
the idea, which was certainly formed on different grounds,
and existed, I believe, prior to my acquaintance with those
facts. Such as it was conceived, it happened to be long af-
terwards thrown out in an essay on the arrangement of bo-
dies on the principle alluded to above. Asa distinct fourth
class of bodies I had arranged ‘together barytes, strontites,
potash, soda, lime, magnesia, aluming, jargonites, silex, &c.,
adding this query “* Does the mode of unten of their ele-
ments render them nonoxidable? or have they already oxi-
gen or phosoxigen closely combined?” and again “ If fu-

ture experiments should accomplish the oxidation of any of

the bodies of the fourth class, such bodies must be transfer-
red to the third class (termed philoxigenous), Should it be

discovered, that oxigen enters into their composition, the

terms philoxigenous and misoxigenous must be changed*.”’
I had observed, p. 218, that, “ more than mere classifica-
tion, I had it in view to place under the reader's eye certain
probabilities, that might lead to the analysis of different
bodies, at present cousidered as simple.” This application
of electricity is a project, which has lain on the surface of
chemistry for above twenty years. - Thave taken all oppors
tunities, public and private, of pressing its execution. The
bodies I have been accustomed to name as the proper sub-
jects for trial were the fusible combustibles, as sulphur and
phosphorus. A gentleman, illustrious for his late success in
these researches, some time ago mentioned to me his having
made this experiment with galvanism. The result was the
iberation of some vapours or gas, which disappeared again
before the body congealed. The mode of investigation
should, in my opinion, still be prosecuted with a much
higher power than has yet been emyployed.
As an incentive and a clew to experiment (which is the
only use of hypothesis) 1 beg leave to repeat, that metals
* Contributions to phys, and med, Knowledge, p. 223, . 4
an

et

ON THE BODIES TERMED SIMPLE. ‘ 14}

and other combustibles may be formed of hidrogen and azote. pianos
The opinion has gained some countenance from the analogy trogen,
between volatile and fixed alkalis, together with the iden- Some confir-
tification of the base of the fixed with metals. The reported ee ibe tap
amalgamation of the base of volatile alkali with quicksilver
is an important link in the same chain of ideas; though the
amalgamation of charcoal with iron, &c. may be opposed, Baad psp me~
unless charcoal prove a metallic oxide or hidrogenate. i
One cannot proceed far in this train of speculation with-
out getting the prospect of all nature as consisting of two
elements, oxigen and hidrogen.
In respect to heat, hght, electricity, galvanism, and mag- Heat, light,
netism, I see not thesmallest reason to regard these as distinct Meee
substances, or other than as powers or influences, if we are netism, not
not to follow Beikeley. We have no right to consider any erie beg a
property whatever as essential to matter. We have there- powers,
fore no criterion of materiality. Yet it appears to me, that Pethaps gravi-
the absence of gravitation is a much stronger negative ar- tation the only
gument than any positive yet produced: and I have no ae ihe
doubt but all those who have set themselves to weigh caloric,
under the notion of its being a separate substance, have
been miserably disappointed at the result of their experi-
ment; and that, had the result been opposite, they would
have trinmphed, and justly, in this proof; for it must have
been received as decisive. Have not adversaries a right to
retaliate ?
The genius of accurate experimental investigation may be We may be oa
now in the art of striding from inanimate to living nature; neues ae
very soon afterward one may venture to predict, that other knowledge of
influences, offering other means of analysis, will be diseo- oe a
vered, less extensive probably than heat, and more so than jh: induen.
magnetism, and constituting the difference between the par- ces, affordi, :
ticles of matter as they happen to be engaged in one class cin ence
of compounds or the other. The Archaeus, vital principle, discovered,
Mr, Hunter’s materia vitae diffusa, &c., will perhaps come Anticipations

~to be considered as anticipations (clumsy and illogical ones oe
indeed) of such influences,

Lam, dear Sir, Yours respectfully,

10th Sept. 1808, THOMAS BEDDOES.
XI.

Proportion of
the metal in
sulphurets
constant.

Magnetic and
other pyrites.

Some still ad-
mit the pre-
sence of oxi-
gen,

Various speci-
mens examin-
ed,

Sulphuret of
iron,

ON METALLIC SULPHURETS.

XT.

Analysis of some metallic Sulphurets. By Mr. GuEeniveau;
Mine Engineer *.

SEVERAL chemists, particularly Messrs. Proust and
Hatchett, have paid attention to metallic sulphurets. The
first of these gentlemen has shown, that certain metals, as
iron, copper, and lead, combine with sulphur in the metal-

lic state and in a constant proportion. Mr. Hatchett has:

given an analysis of the magnetie pyrites, which he consi-
ders as a sulphuret of iron at a minimum, and ‘that of se-
veral common. pyrites, in which he finds other principles
beside iron and sulphur. The experiments of these two
scientific gentlemen however have not impressed conviction
on the mind of every chemist; and some appear still to ad-
mit the presence of oxigen in sulphurets of iron. They
found their objections chiefly on this, that Mr. Proust em-
ployed the method of synthesis, which always leaves some
uncertainty in the proportions: avd that Mr. Hatchett as-
certained the sulphur only by means of sulphate of barytes,
respecting the composition of which some uncertainty still
remains. Having had occasion to analyse certain metallic
sulphurets, I determined their elements with a great deal
of care, in order to satisfy myself on the points just men-
tioned. m

The specimen of sulphuret of iron, on which I made all
the experiments I am about to describe, was amorphous,

without any mixture of gangue. Its colour was the com-

mon bronze yellow of iron pyrites. Various preliminary ex-
periments convinced me, that this mineral contained no
earthy substance, and no other metal than iron. TI shall
now proceed to describe the methods I employed to deter-
mine with precision the quantities of iron and sulphur they
contained.

* Journal des Mines, vol. XXI, p. 105. A translation of a paper
by Mr. Gueniveau on the Desulphuration of Metals, in the same work,
was given in our Journal for November last, vol. XVIII, p. 197...

I, Lxamination

ON METALLIC SULPHURETS. 145

I. Examination for the iron.

1. I boiled a mixture of nitric and muriatic acids on five Analysed.
grammes [77 ers.] of powdered pyrites. The sulphur was wae ater
‘completely burned, and the solution was complete, except
G-01 of a gramme of silex. The oxide of iron precipitated Precipitated by
by ammonia and heated red hot weighed 3°35 gr. : which in- 4™™monia.

dicate, supposing the proportion to be 148 to 100, 2°25 gr.
of metallic iron, or 45 per cent.
Q. Another experiment made in the same manner yielded This repeated.
me 3°34 gr. of red oxide of iron; which coincides with the
preceding.
3. I roasted 20 gr. [308 grs.] of the same pyrites. After Roasted,
being exposed some hours to a pretty violent heat, the weight
was reduced to 13°24 gr.: so that 100 left only 66-2.

Of this residuum I dissolved 5 gr. in nitromuriatic acid. Residuum dis-
Muriate of barytes producing no precipitate in this solution, at a a
I concluded, that the roasting had been complete, and the No precipitate
pyrites reduced to pure oxide of iron. Besides, on com- Nes 7
paring the weight of the residuum of 5 gr. of pyrites, being
3°31 gr., with that of the oxide of iron obtained by the ex-
periment above, namely 3:34 gr., there can be no doubt,
but the whole of the sulphur and sulphuric acid were vola-
tilized. This new method of computing the quantity of
oxide of iron leaves no doubt respecting the proportion of
metal in the pyrites, being equally indicative of 45 per cent
of metallic iron.

4. I fused the roasted pyrites without any addition in a Roasted pyrites.
crucible lined with charcoal, in order to obtain the metal. fused without
The button amounted to 70°2 per cent, without any scorie, mai
Deducting 3 per cent for the carbon combined with it, we
shall have (8:1 of iron from 100 of roasted pyrites, and from
100 of pyrites in its native state 45°08 of pure iron.

From the four experiments here mentioned it follows, Contained 0-45
that the sulphuret of iron contains 45 hundredths of me- of metallic
tallic iron; and I do not think, that any errour can have”
taken place to the amount of one hundredth.

Il. Examination

144 ON METALLIC SULPHURETS:

Il. Examination for the sulphur.

Dissolved in 1. Having dissolved 5 gr. of iron pyrites in nitromuriatic
eer acid with the assistance of heat, I dropped into the solution
muriate of ba- muriate of barytes, till no more precipitate was formed.
Lepen pase The sulphate of barytes subsided to the bottom of the ves-
tity of sulphur. sel; and, having poured off the clear liquor, I added some
distilled water, in order to wash off any foreign salts. I col-
lected the sulphate on a filter. Having dried it, first with.
a gentle heat, increased afterward to redness, and burned
the filter separately, I found the weight of the sulphate of,
barytes, deducting that of the ashes of the filter, was 19°1

gr., or 382 to 100 of pyrites.

2. It might be suspected, that the preceding result was
too small, on account of the state of ebullition in which I:
had kept the solvent, which might have carried off in vapour
a portion of the sulphuric acid formed. I thought it right.,
therefore, to make another experiment, employing a more
moderate heat.

Treated with Accordingly I treated 2°5 gr. of the same pyrites with di-/

pee pe luted nitric acid, heating it gently. The whole of the sul-

heat. phur however was burned except about 0:03 of a gramme
that remained undecomposed. From this solution I ob-
tained 9°71 gr., or 388 per cent of sulphur of barytes, cor-»
responding to 54°3 of sulphur; and, on taking into the ac-.
count the residuum abovementioned, we shall have 54°8 of
sulphur in a hundred parts.

This result I consider as more accurate than the preced-

ing.
0°55 of sul- The experiments I have related clearly show, that the
phur. sulphuret of iron analysed contained about 45 per cent of

metallic iron, and between 54 2nd 55 per cent of sulphur,
results which differ very little from those of Mr. Hatchett.
It is difficult then to conceive, that iron pyrites contain
oxigen, and thé quantity corresponding to ali the mistakes
that could possibly have taken place cannot be many hune
dredths.

Component

ON METALLIC SULPHURETS.- 145

€omponent parts of iron pyrites.

Metallic iron ceeoeceessresene AS
Sulphur eseeverecceeveve HX

| 100.
Sulphuret of copper.

Messrs. Lelievre and Gillet-Laumont, mine-counsellor S} Sulphuret of
having had the goodness each to present me with a speci= COPP&r
men of sulphuret of copper, I shall proceed to give the re~
sults of my analysis of this mineral.

1. Siberian sulphuret of copper from the collection of
Mr. Lelievre. Spec. gravity 5°22.

Five grammes of this mineral treated with nitromuriati¢ Treated with
eid assisted by heat were reduced to 0°51 of a gr. of sul~ #449 "8!
phur nearly pure. Calcination left only 0-04 gre of oxide,
which was completely redisscived.

The solution precipitated by muriate of barytes let fall Precipitated by
4°01 gr. of sulphate, corresponding to 0°56 of a gr. of sul- es Oh Res
phur. This brings the whole quantity of sulphur to 1:03
gr. The iron was separated from the copper by ammonia.

‘The precipitate, well washed and dried, weighed 0:08 of a gr

The brown. oxide of copper precipitated by potash weighed
4°65 gr., answering to 3°72 gr. of metallic copper.

I convinced myself by various experiments, that the spe- No earth, lead,
eimen subjected to- analysis contained no earthy substance, ee oe
lead, manganese, or antimony. The small quantity of iron 4 tittle oxide
existing im it appeared to me even to be included in. small of iron foreign’
fissures, in which its- oxide is easy to be perceived: it cannot '°*
therefore be considered. as an essential. part of the composi-
tion of sulphuret of copper.

The results of this analysis are

Metallic copper +++seees 7495 Component
Sulphur -++-++eeeseeee 205 parts.
Oxide of iron +++eeeseee 155)

ROSE. 0 we «2:00: 010 019.05 m0r0-0 o? > B25,

100.

The experiments I made in the course of the analysis lead
me to.think, that part of the loss fell on the copper.. Not-
withstanding this however, the proportion of sulphur to

Vou. XXI—Ocr. 1808, L copper

cd

146 ON METALLIC SULPHURETS.

copper differs very little from that of 28 to 100 given by
Mr. Proust.
Fused inchar- "This sulphuret of copper, being sisbyeeted to a very vVio-
ani ti lent fire in a crucible lined with charcoal, was fused, and
lost but 22% per cent of its weight. Its aspect was not al-
tered, only a few small globules of copper were perceptible

toward the bottom of- the button.

2, Siberian sulphuret of copper from the collection of Mr.
Gillet-Laumont.

Another spe- | This specimen, though in appearance very homogeneous,

Sao was notwithstanding mixed with a great deal of quartz. In
some places it struck fire with steel.

‘Analysis, I separated the copper from the iron by sulphuretted hf
drogen. The precipitate, calcined, redissolved, and treated
with caustic potash gave me 3 gr. of oxide of copper from
& of the mineral. J found in it no other metal but copper
and iron.

The results were

Component Metallic copper ++++++++ 47
parts, Sulphur--+eecseeeereoes VG
Siliceous residuum «++-++ 25
NTE saree cla evorsle ew ierete is sie 7

Red oxide of iron cesses 93

SS ee

101°3

Proportions of It is to be observed here, that the presence of the diffe=
Has eal rent substances foreign to the sulphuret of copper did not
fected by fo- affect the proportions of the copper to the sulphur, which
Seccheng is evidently that of 100 to 28.° The iron probably is not

combined with the sulphuret, but with the silex and lime

forms its gangue.

Copper pyrites.

Pyritous cop- I, Copper pyrites of Sainbel from the collection of the
per, Council of Mines. Spec. gravity 4°16.

The specimen I subjected to analysis was amorphous, but

without mixture of gangue. Its colour was a greenish

yellow bronze, J ascertained its composition in twe different

methods.
Ist

——— eee rr S—”—~<C;S7;7T7«3; }PTCté™*#f

————

ON METALLIC SULPHURETS. J47

ist analysis. Five grammes of this mineral, powdered, Treated with
and treated with nitromuriatic acid, were very easily attack- “4% regia
ed by it. The residuum, weighing 1°13 gr., was reduced
to 0.08 of a gr. by calcination; and an addition of fresh acid
left only 0:04 of agr. of quartzose gangue.

Muriate of barytes threw down from the solution a préci- Precipitated
pitate of Sulphate weighing 5°5 gt, corresponding to 0°77 eae er
of a gr. of sulphur. This quantity, added to that already
formed, gives 1°82 gr. for the whole of the sulphur it con-

‘tained. The copper was precipitated by sulphuretted hidro- and then by*

: ere . , sulphuretted
gen, redissolved, and precipitated afresh by caustic potash. pidrogen,

The brown oxide obtained weighed 1°88 gr., and contained
nearly 1°5 gr. of metal.

The potash had dissolved about 0°05 of a gr. of oxide of
zinc. The ved oxide of iron weighed 2°26 gr., correspond~
ing to 1°53 of metallic iron.

Results.
Sulphur eoevseoeesee2ee eee 36°5 Component
Copper-+++eess ds vtimes't 30 parts.

Metallic iron -++e «eee 31

Oxide of ziInC ecsceseeeee J]

Gangue Oe. d.cls slewisielieicreve | f
99°5

2d analysis. The same ae was treated with nitric Treated with
acid assisted by heat. nitric acid,

First residuum, 2°35 gr. reduced to 1°86 gr. by calcina- Residuum cal-
tion. The nitromuriatic acid left of this only 0°23 of agr., Oe ie
containing only 0°04 of a gr. of gangue: aqua regia.

The weight of the sulphur separated from these sesiduums Precipitated by
was 0°93 of agr. The solution gave a precipitate of 5:91 fete of
of sulphate of barytes, pare 0°82 of a gr. of sulphur,
and making the whole amount to 1°75 gr.

The copper was dissolyed by ammonia, and the oxide of Copperdissolvs
iron separated from it by several operations, The oxide of ae .
copper precipitated by potash weighed 1°9 gr., answering to separated;
1°52 gr. of the metal.

The red oxide of iron weighed 2°47 gr., and contained

- 1:66 gr. of pure iron.

J likewise found traces of zinc.
L2 Result,

148 ON METALLIC. SULPHURETS,.

Result.

Sulphur --+-+eecereeeeees. 35
Copper seseseeeeecerees SOF
Metallic iron ....2.seese $3
Some traces of zinc

Gangue secceecescesesen 1

ee

99°5:

Component.
Parts.

If we take a mean of the results of these two analyses, we.

shall have as very probable proportions.

Mean of the Sulphur oor eseeeeeseeees 36
e analyses. Copper e@oeeeeoeeeeeevneven 30
Metallic iron +e+esesceses 32:
Gangue serereeecccscces 1
Zine ceoeeeseoeoeeeee eeee ]
100,

Another spe- Jf. Copper pyrites of Baigorry.

eimen.

For the two following analyses I employed pieces of ore.

that were sufficiently pure, though mixed with quartz.

Treated with Ist analysis. Five grammes reduced to powder were sub-.
jected to the action of nitromuriatic acid. The first resi-.

aqua regia.

duum, weighing 1.72 gr., was reduced to 0°73 of a gr. by

calcination. An addition of acid left only 0°54 of a gr.,.

and of these 0°46 were found to be gangue, after the sul-
phur had been burned.

Precipitated The muriate of barytes precipitated from the solution 374,

b i f :
ear. gr. of sulphate, corresponding to 0°5 of a gr. of sulphur.

The whole of the sulphur therefore was 1°57 gr.
and sulphuret- Sulphuretted hidrogen was employed to separate the cop=
ted hidrogen.

ash, weighed 1°69 gr., and consequently contained 1°35 of

metal. The red oxide of iron obtained weighed 2°19 gr.,.

corresponding to 1°49 gr. of metallic iron,

Result.
Component Sulphur eocecaeascscese 31 “5.
parts. Copperss+eeseececcees o QF

Metallic iron «.-+-++---++ 30
Gangue eaceosereoveeice 8°5.

aa
Analysis ree 2d analysis. I treated 5 gr. of the same substance in the
peated, gece

per. The brown oxide of this metal, precipitated by pot-

‘ON METALLIC SULPHURETS. 149

“same way. I separated by calcination 0°34 of a gr. of sul+
phur. The gangue weighed 0°48 of a gr. The sulphate of
-barytes obtained weighed 8°88 vr., corresponding to 1°24 gr.
‘of sulphur. The whole‘of the sulphur therefore wasi°58 gr.

The brown oxide of copper weighed 1°73 gr.; the red
oxide of iron, 2°16 gr.

Result.
Sulphur ee ee ee ee ee 31°5 Component
Copper ew7wee ea ee ee 6 eee 388 parts.

Metallic iron -+.-e..e+e+ 29
AGANZUC +e eres cecseece 9

Mean proportions.
Mean of the
Sulphur eoeesseeeereee 31S two analyses.

Copper -+«- onee voeeee Ds
Metallic MEOH) aissiee fea sms (25
Gangue oeeres covees ee 9
97°5 |
T have reason to think, that the proportions of sulphur are Sule age
: . complete
rather too small, because all the methods employed never give sacaneal
_ the whole of this combustible. |
When metallic sulphurets are treated with nitric acid di- and cou
luted in water, the sulphur remains mixed with the metals, ana eRe
which become oxided during the evaporation. All the oxi-
gen added diminishes the quantity of the sulphur. By em-
ploying nitromuriatic acid and boiling, this inconvenience is
avoided; but sulphuric acid may be carried of in vapour.
Whatever method we adopt, the quantity of sulphur ob-
tained may always be considered as below what really exists.
Notwithstanding the errours unavoidable in analyses, it is Proportions of
easy to perceive, that the relative quantities of sulphur, cop- a te: Soa:
per, and iron, are nearly the same in the two specimens of nearly uni-
copper pyrites. Setting aside the gangue, and reducing the aus

proportions to hundredth parts of pure ore, we find

_ _ Sulphur. Copper. Tron.
In the copper pyrites of Sainbel 37 30.2 32°3
In that of Baigorry -++-+-++++++ 35 30°5 33

Mr. Proust has shown, that the copper pyrites contains A mixture of

aus e ty Ssul=

sulphuret of copper completely formed, and he considers be ae .
this mineral as a mixture of the two sulphurets of copper

and

150

Analysis of
Mr. Chenevix
nearly similar.

"This confirms
the idea of its
uniformity.

The carbonate
described,

ON METALLIC SULPHURETS.

and iron. This opinion appears to me very probable: though
perhaps we have not sufficient grounds to assert, that the
sulphuret of iron exists in it in the same state of combina-
tion as that, which constitutes native iron pyrites.

Mr. Chenevix obtained from a specimen of copper pyrites
0 per cent of copper, and 53 of oxide of iron, correspond-
ing to 35 of the metal. T likewise found 30 per cent of cop=

per in a piece of yellow ore from Chessy. On comparing

these results with those above given, I was struck with the
proportion that exists between the elements of a mineral
generally considered as varying greatly in its composition.
The difficulty of distinguishing it from iron pyrites may
have contributed to this opinion: but I am inclined to think,
that, when copper pyrites is completely homogeneous, and
not decomposed, its composition is the same, from whatever
ore it be obtained; and that it may be considered as a
mineralogical species, ascertained and determined by che-
mistry.

This however is but a simple conjecture, on which nothing

positive can be said, till we have a greater number of analy-=

ses made on well marked specimens free from any mixture.

<i.

Analysis of a Carbonate of Lime from Pesey; by Mr. Bur-
rHIER, Mine Engineer*.

Tue carbonate of lime from the mine of Pesey is found
in geodes grouped comfusedly with quartz, and sometimes
with lenticular polishing spar. Its specific gravity is 2°97.

Its figure is that of the primitive rhomboid of common
carbonate of lime. Jt may be split with great facility, and
divides in the direction of its longer diagonals. All the faces
are covered with stric in this direction. 3

Its hardness is much greater than that of common car-
bonate of lime, which it scratches. It even scratches arra-
gonite. The pieces found on the heaps of rubbish, that

have remained long exposed to the air, have the brown co- .

* Annales de Chimie, vol. LVIIJ, p. 87,
lour

COMPOUND CARBONATE OF LIME. 151

lour of iron spar, It is sometimes perfectly transparent :
but most commonly it has a slight yellowish tint, becomes
opake, and is covered witha brown oxide, as it is decom-
posed in the damp parts of the mine.

Before the blowpipe it becomes black, and is slightly al-
tered. It scarcely effervesces with acids, unless previously —
powdered.

Having powdered end sifted it, I took 5 grammes (77 Analysed.
grains], on which I poured strong nitric acid. On applying peer
a gentle heat, the effervescence immediately became very
brisk; nitrous gas was evolved; and the powder assumed a
brown colour. Having evaporated to dryness, I poured on _
fresh acid, and repeated the same operation.

I next dissolved the whole in muriatic acid, evaporated With muriatic,
gently to expel the excess of acid, and then dissolved in wa- aac
ter. The solution, which was of a light yellow, was precie potash,
pitated by prussiate of potash. The result was a deep blue
prussiate, which was filtered and washed.

The solution, completely neutralized, was precipitated and by oxalate
by oxalate of ammonia, and yielded oxalate of lime, which, ° *™™0mi
when washed and dried, weighed 3°95 grammes.

Caustic potash threw down from the hquor a copious Caustic potash
white flocculent precipitate, which, when washed, dried, eee
and calcined in a red heat, weighed 0°5 of a gr. This sub- ;
stance, which was of a fine white colour, dissolved entirely
in sulphuric acid, and yielded a bitter salt. Carbonate
of ammonia did not precipitate it; therefore it was magne-
6ia.

The prussiates when dried were strongly calcined, and Iron oxided,
the residuum oxided to a maximum by nitric acid.

The oxides were redissolved in muriatic acid; evaporated dissolved in
gently to neutralize them; and then diluted with a large eiDiaitinies «.
quantity of water. No residuum was left,

This solution was precipitated by carbonate of potash, sa- P'ecipitated by
turated, and afterward filtered. poe

The carbonate deposited on the filter was redissolved ‘in redissolved and
muriatic acid, precipitate’ afresh by carbonate of potash, °°“? Sia
saturated, and filtered. 4

The two filtered liquors being mixed together, they were Liquors evapo-
subjected to evaporation for about two hours, when they mie

deposited

152 COMPOUND CARBONATE OF LIME,

deposited a slightly yellowish white substance, which, when
washed and dried, weighed 0:16. Before the’blowpipe it
immediately became black, and communicated a violet co-
Jour to borax. In nitric acid it redissolved with effervess
cence ; the nitrate grew black on drying; and the residuuin,
treated with muriatic acid, gave out -oxigenized muriatic
acid, and produced a brown colour, which heat removed.
Lastly, prussiate of potash threw down from ‘the muriatic
solution a white precipitate, without any perceptible mix-
comer ture of blue. Thus there can be no doubt, that the carbo-
ate deposited by ebullition was carbonate of manganese.
dan ie the ‘The supernatant liquor contained nothing more. The
carbonate remaining on the filter was red. This was dis-
solved in muriatic acid, and precipitated by prussiate of pots
ash, which produced a blue prussiate of iron, weighing, when
-well washed and dried, 1:9. :
The carbonate Five grammes of the carbonate were calcined ina cruci~=
Seened. ble at a red heat, and lost from 1-8 to 1°85 of water and care
‘bonic acid.
‘This substance therefore contained, im 100 parts,

Component Lime -ccsceccsscerecerees ASS

paris. Magnesia voeerecrccersccess 10
Black oxide of iron +++sses2 8
White oxide of manganese -- 2
Water and carbonic acid »+-- 36°5.

100.

Acompeund “Lhus the four carbonates of lime, magnesia, iron, and

of four caibo- manganese, which sometimes occur separately in nature, are

Area found united together 1 in the substance, of which an analy-

sis has just been given. I do not think there can be any

doubt of the presence of the manganese. In one experiment

1 found four per cent cf this metal in the state of white ox-

ide: but I have preferred giving the pr oportion above, which
consequently 1 is a minimum.

These carbo- if the results ‘here related be exact, we may conclude,

nadie that the carbonates of lime, magnesia, iron, and manganese,

may be found in nature in various proportions; so that it is

no wonder we meet with iron spars without manganese, and

others mixed. with manganese alone, without lime or mags

nesia,

SACCHARINE MATTER OF INDIAN CORN. 15S

gnesia. The analyses of these substances become so much
the more interesting to the metallurgist, and we see clearly
one source of the diiierence, that may exist between iron
spars.

XIII.

Chemical Examination of the Stalk of Indian Corn, Zea
Mays Lin., to ascertain whether the Saccharine Matter it
contains be capable of Crystallization; by Mr. V. AUARIE,
Apothecary at Valence, Depariment of the Dréme*.

le it can be said with truth, that our physical knowledge Analysis of vew
of vegetables is a complete science, their analysis indivi- ape
Alually is far from having attained this desirable end. The ‘i
labours of modern chemists however are paving the way for

it; their numerous scientific discoveries have already illus-

trated this subject, of so much importance to the art of
pharmacy; and other arts, as well as that of physic, are

daily availing themselves of it with success. Still we have

to regret, that the analysis of vegetables is most uncertain,

since the results are too often far from satisfactory, and the
synthetical method is in many cases impracticable.

I. I boiled in a sufficient quantity of water fifteen pounds Stalks of In-
of the stalks of Indian corn, freed from their leaves and ae corn boil
roots, and previously bruised. ‘The decoction after it was pry we
filtered was of a goiden yellow colour, and a saccharine
taste. Part of this decoction was subjected to various expe- The decoction
riments, of which the following were the results, tested with

1. A solution of crystallized acetite of lead rendered the acetite of lead,
@ecoction turbid, and separated its colouring and extractive
part. These had subsided to the bottom of the vessel in the
course of an hour, leaving the liquor very clear, and lighter
coloured.

2. The acidulous oxalate of potash produced a sediment, oxalate of pot-
and left the liquor milky. ig

~* Annales de Chimie, vol. LX, p. 61. Some remarks on the char-
coal both of the stalks and seeds of maize, by proi. Proust, were inserted
jn our Journal, vol, XVIII, p. 239.

3. A

154

‘acetite of am-
monia,

muriatic and
oximuriatic

acid,

potash,
lime-water,

sulphate of
iron,

sulphuret of”
potash,
nitrate of mer-
cury,

and alcohol.

Liquor still
saccharine.

Decoction eva-
porated & ieft
at rest, but no
crystals.

Diluted. clari-
fied, and again
left at rest.
No crystals.

Evaporated &
digested in al-
wohol.

Solution.

SACCHARINE MATTER OF INDIAN CORN.

3. A solution of acetite of ammonia heightened its cos
lour, and produced a scarcely perceptible precipitate.

4. Common muriatic acid occasioned no change: but
oxigenized muriatic acid produced a slight precipitate, with-
out altering the colour of the liquor. ‘This precipitate was
occasioned by the oxigen, which attacked the extractive.
matter, and rendered it insoluble in water.

5. Caustic potash produced no change.

6. Lime-water and prussiate of lime rendered it slightly
turbid.

7. Sulphate of iron had no effect on it, not even altering
its transparency.

8. It was the same with sulphuret of potash.

9. Nitrate of mercury was decomposed, and formed a
coagulum, which subsided to the bottom of the vessel and
was of a deep gray colour.

10. Alcohol produced no satisfactory result.

It is to be observed, that none of the reagents employed
either destroyed or altered the saccharine taste, which conti=

nued in the liquor; nothing being decomposed and precipi= —

tated but the gummy extract.

Uf. The greater part of the decoction was evaporated to
the consistence of a sirup, and afterward set by. Having
been left undisturbed for twenty days at a temperature of
10° [50° F.], it was just the same, without any appearance
of crystals or sediment.

IIf. Having diluted it with twenty times its bulk of wae
ter, clarified it afresh, to separate the mucilage that ap-
peared to prevent its crystallization, and reduced it to a sy=
rupy consistence, [ was not more successful, after leaving it
a proper time at rest.

It was of importance therefore, to separate the extractive
matter from the saccharine part. Accordingly I evaporated
the decoction, thus clarified a second time, to the consistence
of an extract, and digested it in a sufficient quantity of al-=
cohol. Twenty-four hours after I filtered it, when the al-
cohol had dissolved half the matter subjected to its action.

The alcoholic solution had the taste of a very sweet dram,
except that it had no aromatic flavour. Its colour was a
brown yellow.

This

SACCHARINE MATTER OF INDIAN CORN. 153

This solution mixed with water underwent no change, re- No resin.
maining perfectly clear; which is a proof, that the alcohol
had dissolved no resin, and that the saccharine matter only
was in the solution.

After having separated the alcohol in the common way, Not crysalliza-
the substance remained fixed, and would not crystallize. It ~
comported itself like the treacle of the shops.

Not being by any means satisfied with the results above Clarified with
mentioned, I again diluted the sirupy matter, that had been media aus
dissolved by the alcohol, with a sufficient quantity of water ;

I added a little lime and white of egg in the clarification ;
and after filtering and evaporating toa due degree I set it by
for two months in a stove, but without obtaining any crystals. No crystals.

I employed successively ali the processes employed insu- Various me-

gar-houses, without avy success. I carried my experiments ee lhe
so far as to boil it wits charcoal, and after I had clarified it, cess.
I was equally unsuccessful. Tt retained, and stili retains,
for I have left it to the effect of time, its honeylike appear-
ance; yet it possesses all the other cnaracters of the true su-
gar extracted from the sugar-cane of the West Indies.

TV. Thesubstance that remained insoluble in the aleohol Matter insolu-
was completely dissolved in distilled water. Its taste was ery wee
saponaceous and slightly saccharine. After evaporating to
the consisteuce of an extract, it weighed four ounces and
half. One ounce of this was treated with nitric acid, which Treated with
dissolved it in the same manner asit would have done a gum. panes
During the solution a great deal of nitrous gas was evolved, itself as gum.
and at the same time oxalic acid was formed.

The remaining three ounces and half of extract were af- Incinerated.
terward incinerated. “ During the combustion a large quan-
tity of carbonic acid was given out; the matter swelled up,
so that the coal was twenty times the original bulk, and very
porous; the residuum, after incineration, weighed half an
ounce; and this, when dissolved, filtered, and evaporated,
was reduced to two drams.

I found by the processes I employed, that the salt re- Carbonate of
sulting from these operations was carbonate of potash with La ‘i
a little magnesia. nesia.

From all that has been said above it follows :

Ist, That the stalk of Indian corn cannot be employed General con
: . for clusions.

156

ON SPRING WHEAT.

for the extraction of sugar, because the expense would x=
ceed the profit, since a hundred weight yields only about
two pounds of saccharine matter.

2d, That the saccharine matter constantly retams the con=
sistence of treacle, and is incapable of being crystallized by
any known process,

3d, That the gummy extract might be employed in medi-

cine as an attenuant, in consequence of its saponaceous

quality.

XIV.

‘On the Culture of Spring Wheat, and the Use of Tincture of
Opium in the Diseases of Cattle: by Major Spencer
CocuRANE, of Muirfield-Houfe, near Haddington, North-
Britain*.

SiR,

I REQUEST the favour that you will prefent my thanks

to the Society of Arts, &c. for transmitting me the 20th vo-

lume of their Transactions, containing my former experi-

Advantages of ments on the culture of wheat sown in the spring, I have

spring wheat,

Should be
sown on wins
ter furrow,

since had further proofs of the advantage resuiting from that

practice. ,

Notwithstanding the extreme cold weather, which we had
here during the months of March, April, and May, I never
saw my spring wheat look better, particularly four acres,
part of a field of strong clay, which I was prevented from
sowing in October, when 1 sowed my other wheat, by wet
weather commencing.

The whole field consists of twenty acres, and received one
ploughing after drilled beans. I sowed on the 14th of
March the four acres, with four bolls or two quarters of com-
mon wheat, on the same earth or furrow wich the land got.
in the month of October.

In the event of land having been fallowed and sufficiently
cleaned before winter, and wet weather setting in so as to pre-
vent wheat being sown at the usual time, I recommend from
experience, that the wheat be sown in the spring on the win-

* Trans. of Soc. of Arts, vol. xxv. p,29, The silver medal.of the So-

ciety was voted to Major Cochrane,
Aer

ON SPRING WHEAT, Ke; | isk

ter furrow, and that it should by no means be plouglied:
@gain in the spring.

The winter frost meliorates the soil, and I think kills the
annual weeds.. [I have remarked that by adopting this mode,.
the land is much less troubled with them, the weeds having
been a general obje¢tion to spring wheat.

If spring wheat follows turnips, the ground fhould: be
ploughed as soon as possible, if the soil is of a wet nature,
to correct the injury the land may have sustained by leading
off the crop, and by the poaching of carts and horses. Frost
will in some degree correct what should never if possible
happen, wet ploughing.

From,the middle ef February till the 10th of March is Proper time for
the proper time for sowing wheatin the spring, provided the Sowing.
land is sufficiently dry. Then on the first furrow let the
seed properly pickled be sown either by diill or broad cast ;
the. usual practice of water furrowing, to keep the land from
too much rain, being properly attended to.

Smee

On the Ufe of Tar for Cattle swelled by eating Clover.

Cows are frequently seized with violent swellings from Tar cures eat
having been imprudently allowed to eat clover when wet, ees
A gentleman recommended to me, as a cure, an egg-shell clover. *
full of tar, immediately to be put down the creature’s throat.

Th two instances of my own cattle I found it had the effect of |
laying the swelling in a few minutes. A neighbour of mine,
whose cow it was supposed could not live five minutes, was, ‘
on application of the tar, unexpectedly recovered, to the
great joy of the poor man.

On Opium and other Preparations from Poppies.
After I commenced farmer, I unfortunately loft four Opiuma eure

horses, by a disorder very frequent in this country, called f°" "¢ stipes

: 4 in horses.
the bats or gripes; some of them dred in a few hours, and

none of them were ill more than two days. For some
years past I have given my horses in such cases a table 7
spoonful of tincture of opium, or liquid laudanum, and
have since lost none. If the fir dose given in some liquid
does not allay the violent pain and swelling, I administer a
second spoonful, which I have hitherto, in all cases, found

tovhave the desired effect, and generally in a very short time.

If

158

Equally useful
to sheep, with
common salt,

Poppies culti-
vated for the
opium.

ON sPRING WHEAT, &c.

If I find the horse very hot and feverifh, and sweating
profusely, as is usually the case in this disease, I order him
to be bled plentifully, and an ounce or more of nitre to be
mixed, and administered with the landanum, keeping the
horse warm, and letting him be well rubbed round the
belly.

A very considerable farmer near me, who has had a medi-
cal education, told me, a few days ago, that he had not lost
a horse since he gave them laudanum,

. Tén days ago I was equally fortunate in a trial of it on
one of my sheep, which, half an hour after being washed
with the rest of the flock, was taken so extremely ill, and
swelled so much, that my herdsman supposed she could not
live, having lost some of his own, which had apparently

een in the same state. Timmediately ordered half a hand-
ful of common salt to be dissolved in half an English pint
of warm water, into which I put sixty drops of the lauda-
num, and poured it with difficulty down the animal’s throat,
which seemed nearly dead. For the fifst five minutes I had
so little hopes of the sheep’s recovery, that I ordered the
man to get his knife ready to cut her throat; whilft he
sharpened the instrument for such purpose, he observed the
animal to move his jaw to a proper position, which had pre~
viously been much distorted ; the eyes then began to quicken,
and apparently to become at ease. In half an hour after-
wards the sheep got on her legs, and remained standing for
some time; a plentiful evacuation soon took place, the swel-
ling subsided, she continued to recover, and in a few hours
from the first attack began to eat and do well.

My intent in these communications is to render generally
public what I have found so very beneficial. At this time,
when harses and cattle are so extremely high in price, every
thing that can tend to preserve their lives, fhould be made
kuown and put to trial.

a ee

I formerly noticed to you, that I had tried on a small
scale, for several years, the culture of white poppies to pre-=
pare opium from them, and an extract or syrup of poppies:
that I had raised a sufficient supply for myself and friends,
and that my extract was equal in effect to any prepared from

foreign

SCIENTIFIC NEWS- 459

Aoreign opium. I recommend the poppy seeds to be sown
in March, in drills,
Beside the advantages from the poppy heads as a medi- and for oil.

cine, the seeds yield a valuable oil. Two pounds of the

seeds furnish by expression seven ounces of a pure bland

oil, useful for portrait painting and other purposes. It has

- been proved in Holland to be equal in quality to fine salad

or olive oil, and it would probably be advantageous. to pro

pagate largely so valuable a plant*.

I am, Sir, your humble servant,

SPENCER COCHRANE.

SCIENTIFIC NEWS.
Decomposition of the Earths.
Iw a paper lately read before the Royal Society Mr. Davy Metals obtain-

has detailed a number of experiments, made by means of ed from most
Voltaic electricity, on the common and alkaline earths, of the earths.
by which he has succeeded in effecting their decomposi-

tion, and obtaiuing metals from most of these refractory

bodies.

His method of decomposing the alkaline earths is by elec= Revived in al-
trifying mixtures of them and metallic oxides, such as those loys by mixing
of quicksilver, silver, and tin. The common metals and with metallic
the metals of the earths are revived together in alloy. gities:

He has succeeded in obtaining the pure metals of barytes p. . o¢ 4

° Beka 5 = aq
and strontites, by distilling their amalgams: and in the yytes & stron»
same way has procured the metals of lime and of magnesia tites,
nearly pure. Lime and mag

He has obtained marks of the decomposition of alumine 2°! _
and silex, by electrifying mixtures ef these earths and pot- i: and
ash, but has not yet succeeded in obtaining their metals pure. :

Mr. Davy has repeated a remarkable experiment of Hidrogen and
Messrs, Berzelius and Pontin, of Stockholm, from which it nitrogen form
appears, that hidrogen and nitrogen are capable of com- 2% amalgam
bining with quicksilver, and of forming with it a metallic Wi" mercury.
amalgam, which by oxidation produces ammonia.

mes SET Cw aad

Mr. George Singer will commence his lectures at the Lectures on the
Scientific Institution, No. 3, Princes Street, Cavendish 2tures use, &
Square, early in November, with an extensive course, on hg mapncher
the nature, use, and properties, of the atmosphere, an his- *
torical sketch of the progress of atmospherical discovery,
and an experimental elucidation of every interesting pheno-
menon dependent on the agency of air, including pneuma-

i. hydrostatics, natural chemistry, and meteorology, il-
Jugtrated by an extensive and appropriate apparatus.

* On this subject see our Journal, vol, XIX, p. 282.

METEOROLOGICAL JOURNAL,
For SEPTEMBER 1808,

Kept by ROBERT BANCKS, Mathematical Instrument Maker,
f in the StRAND, Lonpon.

| Ser ita wie
AUG.) 3 a 2 | BAROME-
a o| od TER. :
Day of! | a | | = | | Night. Day.
Al al am) |) ee
97 | 61161] 71 | 52| . 29°63 Fair Fair
28 52157 | 67 | 54 29°7 4 Ditto Ditto:
29 | 59/62]|69) 50} 29°93 Ditto Ditto
BO helo 00 7.2 BO AB. Ditto Rain
31 63160168 159| 29°64 | Ditto Ditto.
SEPT
62159167155} 29°66 Cloudy Rain
29 | 611/561 651] 55 29°84 Ditto Ditto:
3 581560165149] 29°86 Fair Ditto
m 1.62:| 57 | 64 1.53 |. 29°83 Ditto Ditto.
5 161157 | 64155] 29°80- | Ditto Ditto:
6 | 59.158 |63) 54} 29°77 Rain Ditto
7 |581|60-|64}57 | 29°82 Ditto Ditto:
gs | 61157 166/55} 29°64 Fair Ditto
9 | 57159 |} 62] 54} 29°38 Rain Ditto
RO! 156 [57 1-60 | 53-1 -. 29°37 Fair* Ditto
11 | 56| 56 | 60154} 29-51 | Ditto ~ Ditto
12 {55156 59154} 29-66 Cloudy Ditto
13°156|58 | OL} 51} 29°74 Ditto Ditto:
14 | 571 581-631 57 f 29°82 Ditto Fair
15 |62]}60|68/56| 30-05 | Pair Ditto:
16° |} 61 (57 | 65) 52’) ©30-26 Ditto Ditto
17 | 60] 58 | 64 | 54) . 30-22 | Ditto Ditto
18 59 | 61 | 66 | 58 29°98 Ditto Rain
19 | 611/59 |65|53 | 29:99 Ditto Ditto:
20 | 58158 |66|] 50| 30-23 Ditto Fair
91° P57) 57 (04) 52 1° 3031 Ditto Ditto:
22 | 56|60}68} 52} 30-15 Cloudy Rain
23 56 | 50 | 64 | 44 29°71 Fair Ditto
a4 | 48]61154)48 | 29:99 | Ditto Fair ©
25 | 52154157549 |. 30°08 Ditto Ditto,

*- Foggy at midnight, tT Thunder at 11 A. My.

~

A

JOURNAL”

NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

NOVEMBER, 1808. a

ARTICLE I.

Observations on the Exhausting Machine of Dr. Tuomas
Srewart TRAIL, by Mr. Ropert Bancxs, Mathema~
tical Instrument Maker, in the Strand.

To Mr. NICHOLSON.
SIR,

ly the present enlightened state of science, it is not to The same
be wondered, that different scientific men should have simi- ae oe
lar ideas, with the hopes of constructing instruments in the eee
utmost state of perfection. Jam led to this reflection by a
description of a machine, in your Journal for last month,
nearly similar in construction to one made by me ten years
ago for Bracey Clark, Esq., a gentleman well known in the
scientific world.

After some ingenious observations by Dr. Traill, on the Air pump.
impossibility of obtaining a perfect vacuum in the air pump
of ordinary construction, he says, p. 63, “ it occurred to
me, that, if there was a convenient method of using the Torricellian
Torricellian vacuum, it would be preferable to the common pie Eake B
air pump, even when best constructed. After various at. © ;
tempts, the annexed figure and description will give an idea

Vou. XXI. No, 93—Nov. 1808. M of

162

Plausible in
theory.

The larger the
apparatus pro-
bably the less
perfect the va-
cuum,

Defect in the
cever,

No gauge.

An apparatus ,
similar to Dr.
Traill’s.

Description of

the parts that
differ,

EXHAUSTING MACHINE BY MERCURY.

of the machine, which I concieve well adapted to answer the
end proposed.”

With all deference to Dr. Traill, I must suppose his. —
ideas are theoretical; and they certainly appear, to those
who have not tried such experiment, admirably, calculated
to produce a perfect vacuum on the Torricellian principle:
but I am inclined to think, that the larger an apparatus of
this kind is, the more imperfect it must be; since every ex-
perienced artist well knows what extreme care is requisite
in making barometers of the best construction, where we
are obliged to boil the mercury to exclude air and vapour ;
and as the same means cannot be applied to the instrument
alluded to, it follows. in consequence, that the air cannot be
completely excluded, by the simple manipulation of filling
with mercury, and permitting its descent.

After Dr. Traill has described the instrument, he directs
the whole to be filled with mercury, and its cover then to
be placed on, Now I believe it is well known from the laws
of repulsion, that it will be impossible to fill the receiver in
such a manner, as to admit the cover to be put into its pro-
per place, and at the same time exclude all the air neces-
sary for a perfect exhaustion, or vacuum. The state of this
vacuum too cannot be determined, without a gauge, for
which there is no provision in the instrument described.

As I have intruded.thus far, I beg to say, that, in the
early part of this year, I made a similar apparatus for J. G.
Children, Esq. F.R.S. as contrived by himself; and as it
appears to have a decided advantage over thatof Dr. Traill,
I trust a brief description of it may be admitted.

It may .be sufficient to say, every part is similar in prin=-
ciple to Dr. Traill’s, but the recipient of small capacity, and .
the cover marked B admirably constructed to remove every .
objection as to the complete filling with mercury. Let fig.
A therefore represent the recipient; B the cap, the under
side conical as shown; C, a cock with a funnel; D, another
cock on the. opposite side of the cap. Now after the receiver
was filled as high as convenient, the cap (or stopper) was.
put into the neck. Mercury was then poured into C through
the funnel, until it passed out at D. (according to ithe, law.
of fluids finding its level), when both the cocks being turned,

communication

EXHAUSTING MACHINE BY MERCURY. 163
‘communication with the atmosphere was cut off. The cock
was then opened at the bottom of the tube E, the mercury
descended, and some sort of vacuum was produced.

In order to see the state of this vacuum, as we had an State of the
iron tube, I suggested a gauge, which was easily intro- pescimgnletis
duced before filling, and floated on the surface of the mer- —
cury within the tube. The index of this gauge, passing
‘ into the vacuum, exhibited the height of the mercury. But
I must confess, though every part was perfectly tight, and
I believe well made, the mercury well dried, and the ma-
chine much agitated in filling, to dislodge the air, it did
not afford the satisfaction sought after. From this failure
I am inclined to think, that so good a vacuum cannot be Not equal to

; . ; that of a gaod
obtained by such a mercurial apparatus, as with a pump of ai; pump.
the best construction, that will indicate an exhaustion to
the 7; of an inch with the nicest test, a siphon gauge.

Should you think these observations worthy a place in
your Journal, they are at your service.

lam,
Your very humble servant,

Sept. 9, 1808. R. BANCKS.

P.S. Could Dr. Trailfs instrument be made perfect,
and to supersede the use of our best pumps in nice experi-
ments, many of those that may be deemed of importance
must be laid aside, from the expense that would be incur- Expensive.
red, as the apparatus could be made only in iron or steel,
and would come much more expensive than it does at pre
sent.

a

ANNOTATION.

IN giving Dr. Traill’s instrament, I never had an idea, The vacuum
that a perfect vacuum would be obiained by it. The great Nikiaeverins
difficulty of freeing the mercury from air, it is probable, must
ever prove an insuperable obstacle to our complete success.

I think farther it is very questionable, whether the contact
between the mercury and the sides of the tube would be so
complete, as perfectly to prevent'any air from insinuating

itself between them, But the grand utility of the machine
: M 2 invented

164 ON SUPERACID AND SUBACID SALTS.

Butitisac- invented by Dr. Traill, as well as of those previously in-

yr seniciab wed vented unknown to him, and here mentioned by Mr. Bancks,

facility. appears to me to consist in the being able by its means to
exhaust the receiver in a very considerable degree, at a sin-
gle operation, and without any labour. This great saving
of time may be an object of importance on some occasions;
as I conceive the exhaustion would be considerable, though
not complete, or even equal to that of an air pump of the
best kind: for nothing in the remarks of Mr. Bancks. con-
tradicts this, and the opinion of Dr. Traill is not merely
theoretical, since he rests it on his own experience, though
he had not the advantage of an able artist,

If.

On Superacid and Subacid Salts. By Wiitiam Uypr
Wortaston. M.D. Sec. R. S*.

Superoxalates In the paper which has just been read to the Societyt,
-haveadouble Dr, Thomson has remarked, that oxalic acid unites to stron-
portion ofacid. +135 as well as to potash in two different proportions, and
that the quantity of acid combined with each of these bases
in their superoxalates is just double of that which is satu-
rated by the same quantity of base in their neutral com-
poundst.
Thesamelaw As I had observed the same law to prevail in various
peal other instances of superacid and subacid salts, I thought it
not unlikely, that this law might obtain generally in such
compounds, and it was my design to have pursued the sub-
ject with the hope of discovering the cause, to which so re-
gular a relation might be ascribed.
Thisioneeese But since the publication of Mr. Dalton’s theory of che-.
of amore ge- mical combination, as explained and illustrated by Dr.
ee om Thomeony, the inquiry which [ had designed appears to be
Dalton. \
* Philos. Trans. for 1807, p. 95.
+ See our Journal, p. 19 and 22 of the present vol.
} Thomson's Chemistry, 3d Edition, Vol. IJ, p. 425.
superfluous,

ON SUPERACID AND SUBACID SALTS. 165

superfluous, as all the facts that I had observed are but par-
ticular instances of the more general observation of Mr.
Dalton, that in all cases the simple elements of bodies are
disposed to unite atom to atom singly, or, if either is in ex-
cess, it exceeds by a ratio to be expressed by some simple
multiple of the number of its atoms.

However, since those who are desirous of ascertaining the A few easy ex-
justness of this observation by experiment may be deterred eee
by the difficulties, that we meet within attempting to deter-
mine with precision the constitution of gaseous bodies, for
the explanation of which Mr. Dalton’s theory was first con-
ceived; and since some persons may imagine, that the re-
sults of former experiments on such bodies do not accord
sufficiently to authorize the adoption of a new hypothesis,
it may be worth while to describe a few experiments, each
of which may be performed with the utmost facility, and
each of which affords the most direct proof of the propor-
tional redundance or deficiency of acid in the several salts.
employed.

Subcarbonate of Potash.

Exp.1. Subcarbonate of potash recently prepared, is Subcarbonate
one instance of an alkali having one half the quantity of °f Po'ash.
acid necessary for its saturation, as may thus be satisfacto-
rily proved.

Let two grains of fully saturated and well crystallized car-
bonate of potash be wrapped ina piece of thin paper, and
passed up into an inverted tube filled with mercury, and let
the gas be extricated from it by a sufficient quantity of mu-
riatic acid, so that the space it occupies may be marked upon
the tube.

Next, let four grains of the same carbonate be exposed for
a short time to a red heat ; and it will be found to have part-
ed with exactly half its gas; forthe gas extricated from it in
the same apparatus will be found to occupy exactly the same
space, as the quantity before obtained from two grains of
fully saturated carbonate.

Subcarbonate of Soda.

Exp.2. A similar experiment may be made with a satu- Subcarbonate
rated Of Soda.

166

Supetsulphate
of potash,

ON SUPERACID AND SUBACID SALTs.]

rated carbonate of soda, and with the same result; for this _
also becomes a true semicarbonate by being exposed for a
short time to a red heat.

Supersulphate of Potash.

By an experiment equally simple, supersulphate of potash
may be shown to contain exactly twice as much acid as is ne-
cessary for the mere saturation of the alkah present.

Exp. 3. Let twenty grains of carbonate of potash (which
would be more than neutralized by ten grains of sul-
phuric acid) be mixed with about. twenty-five grains of that
acid in a covered crucible of platina, or in a glass tube three
quarters of an inch diameter, and five or six inches long.

By heating this mixture till it ceases to boil, and begins to
appear slightly red hot, a part of the redundant acid will be
expelled, and there will remain a determinate quantity form-
ing supersulphate of potash, which when dissolved_in water
will be very nearly neutralized by an addition of twenty
grains more of the same carbonate of potash; but it is ge-
nerally found very slightly acid, in consequence of the small
quantity of sulpburic acid which remains in the vessel in a
gaseous state at a red heat,

In the preceding experiments, the acids are made to ass

sume a determinate proportion to their base, by heat which

Superoxalate
of potash.

cannot destroy them. , In those which follow, the proportion
which a destructible acid shall assume cannot be regulated
by the same means; but the constitution of its compounds,
previously formed, may nevertheless be proved with equal
facility.

Superoxalate of Potash.

Exp. 4. The common superoxalate of potash is a salt
that contains alkali sufficient to saturate exactly half of the
acid present. Hence, if two equal quantities of salt of sors
rel be taken, and if one of them be exposed to a red heat,
the alkali which remains will be found exactly to saturate the
redundant acid of the other portion.

In addition to the preceding compounds, selected as dis-
tinct examples of binacid salts, I have observed one remark-
able instance of a more extended and general prevalence of

the

ON SUPERACID AND SUBACID SALTS. 167

the Jaw under consideration; for when the circumstances are
suchas to admit the union of a further quantity of oxalic
acid with potash, I found a proportion, though different, yet
analogous to the former, regularly to occur.

Quadroxalate of Potash.

In attempting to decompose the preceding superoxalate by Quadroxalate
means of acids, it appeared, that nitric or muriatic acids are % Potsh-
capable of taking only half the alkali, and that the salt
which crystallizes after solution in either of these acids has
accordingly exactly four times as much acid as would satu-
rate the alkali that. remains.

Exp. 5. For the purpose of proving, that the constitu-

tion of this compound has been rightly ascertained, the salt
thus formed should be purified by a second crystallization in
distilled water; after which the alkali of thirty grains must
be obtained by exposure to a red heat, in order to neutralice
the redundant acid contained in ten grains of the same salt.
The quantity of unburned salt contains alkali for oue part
out of four of the acid present, and it requires the alkah of
three equal quantities of the same salt to saturate the three
remaining parts of acid.

The limit to the decomposition of superoxalate of pot- Sulphate of
ash by the above acids is analogous to that which occurs inst 2
when sulphate of potash is decomposed by nitric acid; nitric acid.
for in this case also, no quantity of this acid can take moire
than half the potash, and the remaining salt is converted
into a definite supersulphate, similar to that obtained by heat
in the third experiment.
Itis not improbable, that many other changes in chemis- Many chemi-
try, supposed to be influenced by a general redundance of Miguel ue ane
sume one ingredient, may in fact be limited by a new order this law.
of affinities taking place at some definite proportion to be

expressed by a simple multiple, And though the strong
power of crystallizing in oxalic acid renders the modifica-

tions of which its combinations are susceptible more distinct
than those of other acids, it seems probable, that a similar
play of affinities will arise in solutions, when other acids ex-
geed their base in the same proportion.
In order te determine whether oxalic acid is capable of Potash will not
uniting

s

168 . ON SUPERACID AND SUBACID SALTS.

unite with 2 uniting to potash in a proportion intermediate between the
bi io tony double and quadruple quantity of acid, I neutralized forty-
eight grains of carbonate of potash with thirty grains of oxa-
lic acid, and added sixty grains more of acid, so that I had
two parts of potash of twenty-four grains each, and six
equivalent quantities of oxalic acid of fifteen grains each, in
solution, ready to crystallize together, if disposed to unite,
in the proportion of three to one; but the first portion of
salt that crystallized was the common binoxalate, or salt
of sorrel, and a portion selected from the after crystals
(which differed very discernibly in their form) was found to
contain the quadruple proportion of acid. Henceit is to be
presumed, that if these salts could have been perfectly se-
parated, it would have been found, that the two quantities of
potash were equally divided, and combined in one instance
with two, and in the other with the remaining four of the six
equivalent quantities of acid taken.
Propertions of = "T'o account for this want of disposition to unite in the pro-
acid andalkali. tion ‘of three to one by Mr. Dalton’s theory, I appre-
hend he might consider the neutral salt as consisting of
2 particles potash with 1 acid,
The binoxalate as 1 and 1, or 2 with o.
The quadroxalate as_ 1 and 2, or 2 with 4,
in which cases the ratios which I haye observed of the acids
to each other in these salts would respectively obtain.
Perhaps the But an explanation, which admits the supposition of a
ee aren double share of potash in the neutral salt,is not altogether
ratio of the ele- satisfactory; and I am further inclined to think, that phen
ye our views are sufficiently extended, to enable us to reason
) with precison concerning the proportions of elementary
| atoms, we shall find the arithmetical relation alone will not
be sufficient to explain their mutual action, and that we shall
| be obliged to acquire a geometrical conception of their rela-
. tive arrangement in all the three dimensions of solid exten-
| sion.
| Example. For instance, if we suppose.the limit tothe approach of
particles to be the same in all directions, and hence their
virtual extent to be spherical (which’is the most simple hy-
pothesis) ; in this case, when ‘different sorts combine singly

| there

ON SUPERACID AND SUBAGID SAL'Ts?- 169

there is but one mode of union. If they unite in the pro-
portion of two to one, the two particles will naturally arrange
themselves at opposite poles of that to which they unite.
If there be three, they might be arranged with regularity, at
the angles of an equilateral triangle in a great circle sure
rounding the single spherule; but in this arragement, for
want of similar matter at the poles of this circle, the equi-
librium would be unstable, and would be liable to be de-
ranged by the slightest force of adjacent combinations ; but
when the nuinber of one set of particles exceeds in the pro-
portion of four to one, then, on the contrary, a stable equi-
librium may again take place, if the four particles are situate
at the angles of the four equilateral triangles composing a
regular tetrahedron.

But as this geometrical arrangement of the primary ele- This merely
ments of matter is altogether conjectural, and must rely for Li Gan a
its confirmation or rejection upon future inquiry, | am de-
sirous, that it should not be confounded with the results of
the facts and observations related above, which are sufhi-
ciently distinct and satisfactory with respect to the existence
of the law of simple multiples. It is perhaps too much to
hope, that the geometrical arrangement of primary particles
will ever- be perfectly known; since even admitting that a
very small number of these atoms combining together would
have a tendency to arrange themselves in the manner I have
imagined; yet, until it is ascertained how small a proportion
the primary particles themselves bear to the interval between
them, it may be supposed, that surrounding combinations,
although themselves analogous, might disturb that arrange-
ment, and in this case, the effect of such interference must
also be taken into the account, before any theory of chemi-
eal combination can be rendered complete.

Il.

170

Premiums for
sweeping
chimneys.

Experiments.
Rope stiffened
with whale-
bone.

MACHINE FOR CLEANING CHIMNEYS,

IIT.

Account of Experiments on Sweeping Chimneys, by Mr. Guorce
SMART*.

Tur miseries, to which children employed within the flues:
in cleansing chimnies are liable, induced the Society for the

Encouragement of Arts, &c., to offer premiums in the year

1808, to obviate the necessity of so cruel a practice. In the
year 1806, the gold medal was adjudged to Mr. George Smart,
of the Ordinance Wharf, Westminster-bridge, for the greatest
number of chimneys. cleansed under his direction by mechani-
cal means, and a particular account of the method used by
him for this purpose will be found in the 23d Volume of the
Society’s Transactionst. During the present session, a gold
medal has also been voted to him for the best machine pro-
duced to the Society for the intended purpose; an explana-
tory engraving of which having been given in the volume
above-mentioned, renders one unnecessary here. The follow-
ing communication has been received from him, and a com-
plete machine is preserved in the Society’ s repository for pub-
lic inspection.

SIR,

Since the middle of February last, I haye been trying expe-
riments in chimney-sweeping; my first was, stiffening a rope
with whalebone, but found it would not be portable, and that
it would be otherwise inconvenient, as in passing from one
room to another in the same house, even with the greatest
care, it would be almost impossible to avoid touching the
paper on the staircases, particularly where; they are narrow.
In passing through the street, with such a machine, it would
be also very troublesome.

If the brush is made to fill the flue, which ought to be the

® Transac, ofthe Society of Arts, vol. XXV, p. 97.

+ See also our Journal, vol. VI, p. 255,

I See Journal, vel. VJ, plate 13,
case,

MACHINE FOR CLEANING CHIMNEYSe ; 171

case, a substance of an elastic nature has not power sufficient
when the brush is forty or fifty feet up, especially where there
are sharp turns in the flues; the force apptied to send the
brush up is principally spent in friction on the sides of the
flues, and of course would soon cut through any flexible sube
stance that combines the whalebone, or other elastic sube
stance used.

My next attempt was to join elastic rods together by screws Elastic rods
: - : : : de tid fastened with*
in the joints, but this plan w cule not do in passing sharpel+ ews in the
‘bows, as the joints would be strained, and soon unfit for use, joints.
and a danger of the joints slipping or breaking, which would

leave the brash in the flue.

I then thought of the simple portable machine fF have sent Machine for-
for the inspection of the Society; its cheapness, durability, a describes
and power of execution, will, [ hope, recommend it. J think
with perseverance it will abolish the practice of climbing
boys; I have used it in several lofty chimnies, and am con-
vinced it may in time become general. 1 have also sent a rod
and curtain that may be fixed to any opening of a chimney
piece, from six inches to five feet, without using nails or forks
in the common mode, to the injury of the wainscot or chim-
ney piece.

My method of working the machine is, by first putting up ygethod of
the brush, then pressing forward one tube after another, as using it,
strung upon the rope, till the brush meets with an elbow in the
flue; then it is necessary to tighten the rope by pulling it un-

_der the feet, or by means of asmall pulley, and putting in one
of the small screws to pinch the rope; then make a fresh push,
and by shifting the two serews, the one to relieve the other, it
will pass the elbow, and possess sufficient stiffness to allow the
brush to be forced forward to any height.

I have tried the heath and hair brushes, and find, that if the Brushes.
flue is well filled, it does not require so hard a substance as
heath, as it brings down the mortar with the soot. The
brushes of hair, and those formed from the article of which
carpet brooms or whisks are made, | think will answer the
best for general usg.

This

172

Tried with
success,

Muck used.

Price.

Advant ges.

MACHINE FOR CLEANING CITIMNEYS.

This is to certify, that Mr. George Smart, of Cambden
Town, by means of a machine of his own invention for sweep-
ing chimnies, has made two experiments on my hall and pars
Jour chimnies, to ascertain the practicability of raising the
machine through their various windings. The first of these
flues measures upwards of fifty feet from the hearth, and the
operation was performed with apparent ease, sending down
a quantity of soot, together with some wet mortar, although
the flue had been recently swept by a regular chimney fweep-
er. The other from the hearth measures sixty feet, and al-
though there are no less than three elbows in it, running in
opposite directions, (as the boy informs me), the operation
was performed within rine minutes.

JOHN TROTTER.
Soho Square, May 2, 1803.

Certificates were also received from Mr. H. W. Dietrichsen,
of Pratt place, Camden Town; Mr. Charles Mill, No. 4,
Gloucester place, Camden Town; Mr. John Mason, and the
Rev. Jeremiah Joyce, of Camden Town, testifying that they
had seen Mr. Smart’s machine at work, and that they ap-
proved thereof.

Sir,

T have the pleasure to inform you, that my machine for
sweeping chimnies succeeds far beyond my expectation, and
that I am not able to attend to one half of the orders I could
have for its use.

His Royal Highness the Prince of Wales has directed, that
the chimnies et Carlton-house, also those at the Pavillion,
shall for the future be cleansed by my machines. If have also
had orders to send to different parts of the kingdom my ma-
chines ready made, where they have been the means of pro-
viding a comfortable subsistance for poor persons not capable
of other business. .

The price of a machine to ascend 60 feet, including rod,
curtain, extra brush, and box, is £4 14s. 6d.

There are two particular advantages attending. my ma-
chines; namely, that of sweeping a great number of narrow

flues

aay
P }

MACHINE FOR CLEANING CHIMNEYS.

- flues which no child can get up, and that of extinguishing
chimnies when on fire, by placing a wet cloth over the brush,
and forcing it up the chimney,

The construction of the machine is so fully shown by the
description and engraving of it in page 256, of the 23d vo-
lume of the Society’s Transactions*, thatit will be unneces-
sary to say more upon the subject.

Lam, Sir, your humble servant,
GEORGE SMART.
—=— Ny

When I first mentioned this machine in the Journal, vol. VI,
I promised to see it tried inmy own house. This [ have since
: done, and find no reasun to modify any thing there said, as if
performed its office to my perfect satisfaction.

IV.

Description of a Machine for Cleansing Chimneys, without the
use of climbing Boys. By Mr. Joszepu Davis, No. 14,
Crescent, Kingsland Road+.

Sir,

I Had the pleasure of submitting to your inspection, a mo-
del of a machine for the purpose of cleansing chimneys, on
the 3d of May, 1803,and which I wished to be brought before
the Society of Arts, being convinced, that the approbation of
| so respectable and enlightened a body of men would greatly
_ tend towards the superseding the use of climbing boys; and I
| shall, therefore, feel myself greatly obliged if they would ex-
; ‘amine the machine, and favour me with their opinion on it.

| . I am, Sir, very respectfully yours,

% JOSEPH DAVIS.

' Sar,

| The brush part of the model of my machine for cleansing
chimnies, which Isent youon the 3d of May 1803, not hav-
in * Or vol. VI of our Journal.

| $ Transact. of the Society of Arts, vol. XXV, p. 101. The Society
| voted the silver medal to Mr. Davis, his machine being cone¢ived next
ia merit to Mr, Smart’s, See the preceding Article.

ing

‘hPa

173

Machines for
cleansing
chimneys.

174

Used with suc-
cess.

Its advantages,

Remarks on
the machine,

MACHINE FOR CLEANING CHIMNEYS.
ing any hair init, I am now enabled to forward you one ina
more perfect state, which I had the honour of using in
the presence of his Lordship the Bishop of Durham, at the
Military Hospital, Westminster, on the 11th of June, 1803,
and at the Jennerian Society, in Salisbury square, Fleet
street, on the 22d of the same month, and in the same year;— |
a certificate of which, signed by the gentlemen who were pre-
sent", [ had the pleasure of sending you. I have also sent
three lengths of the rod, (the same as those which were used
at the above places), in order to enable the Committee to judge
with greater ease of the construction. Permit me neverthe-
less to observe, that the principle of my rod is so simple and
secure, that it may be used in almost every chimney with
safety, either by the maid servant, or a boy of twelve years of
age; it is calculated both for private and public use, and a
stranger to the machine, who used it at the Military Hospital,
declared he could sweep any chimney with it, the plan was so |
good. It will also sweep German and other stove pipes, and |
flues of almost every description. If the gentlemen of the
Society will do me the honour to take the machine into their
consideration, I will wait on them by hearing from you, and
explain farther particulars.

I am, Sir, your obedient servant,

Sir, JOSEPH DAVIS.

TI am glad that I have had an opportunity of giving’ my opi- |
nion of your machine for cleansing chimnies, which I have
done by signing the certificate you brought me on Monday last. |
Tam of opinion, that your machine is capable of sweeping a |
very great proportion of the chimneys in London and else+
where ;. perhaps there are not more than one or two ina hun-
dred, which it cannot be raised in. At present, there are (as
is well known to all chimney sweepers) some chimneys so |
small, that boys cannot climb them, so that on the whole I |
imagine, that your machine will sweep about the same num- |
ber of chimneys as are swept by boys, though not exactly the |
very same flues in every instance. qi

I hope in time we shall convince the public, that they can

* B, M, Forster, Joseph J.eaper, and James*Hebdin, Esqts.

MACHINE FOR CLEANING CHIMNEYS. ‘175

‘have their chimneys swept with as much cleanliness, and as
effectually with machines, as they have heretofore had them
done; and I am convinced that they may be swept as cleanly
and effectually as is commonly done with climbing boys, so
that the difference to the families who employ your machine
wilk be, that they have the same comfort of a clean chimney,
and are satisfied, that they no longer use a method which is
full of horrors, and a disgrace toa civilized country.

I remain, Sir,

Your obedient servant,

B. M. FORSTER,
moan eae

Reference to the Engraving of Mr. Davis’s Machine for Cleans-
ing Chimneys, Pl. V, fig. 1,2,3, 4.

Fig. 1 Represents: the upper part of the machine; A A Description of
A A are four brushes for sweeping the four sides of the chim- the fern ws
ney, they are hinged to the bottom of a tube about three inches
diameter; BB show two of the four springs which expand
the machine to chimneys of all sizes. The heads of the
brushes are made about six inches long, and five wide; and
form portions of cylinders, the hair being left longer at the
top than the bottom. ‘The hair at the ends of the brushes
being left still'longer, namely, three inches and a half, for the
purpose of sweeping the corners of the chimney. C represents
the brush at: the top of the machine proper for cleansing the
pot; the machine may be used either with or without it, but it
is very-uscful for cleansing stove pipes, by, being used alone; it
is secured to the top of the rod by means of a spring and
socket, as the rods below mentioned. D D DD, four lines te
draw the brushes near together by a cord E, so that the ma-
chine may be forced up the chimney with greater facility. IT’,
the string to expand the brushes when the machine is at the top
of the flue.

Fig. 2 Shows on a larger scale the top of one of the rods
separate. G, the spring attached to it.

Fig. 3 Explains the manner in which the rods are joined
together. H _ being a brass socket fixed at the lower end of

each

Method of
musing it.

MACHINE FOR CLEANING CHIMNEYS.

eaeh rod; the spring G, and upper erd of the rod fig. 2, are
pressed into this socket so far, that a small point I, on the
upper end of the spring, rises through a small hole in the brass
socket, and retains the lower end in the socket. Each rod is
made of hiccory wood, which being tough and flexible, is parti-
cularly well calculated for this use, bending and adapting it-
self to the different turns it meets with.

Fig. 4 Shows the key to unleck the rods; it issix inches
long, and made from a piece of one of the rods, with a steel
stud K inthe middle, rising a quarter of an inch, and a brass
plate on one side projecting the thickness of the rod to guide
it into the socket, that it may be used without looking at the
rods.

The method of cleansing the chimney is, by first entering
the brush part of the machine, with the brushes closed, and
one of the rods attached to it, up the chimney ; the head of a
second rod is then slided as above mentioned into the socket of
the first rod, and the brush by it forced higher up, a third rod
is then slided into the socket of the second, and this mode con- —
tinued till a sufficient number of rods are added to raise the
brush to the top of the chimney. The string E, extending
from the brush to the bottom of the chimney, being then pul-
led, occasions the four brushes to expand to the width of the
flue, and to bring down with them in their return all the soot
which adhered to the sides of the flue. As the machine is
drawn down, the rods are separated one by one by means of
the key, and laid upon the hearth till the brush part is brought
down, which is then closed and laid with the rods.

The usual precautions must be taken of placing a curtain
before the fire-place, to prevent the soot, while falling, from
flying about the room.

JOSEPH DAVIS.

V;

Wichalsons Philos Journal Vol. ALP US. pl7O.

M- Mendham Ccafe ment

ALA

tl

SECURITY AGAINST HOUSE-BREAKERS. 177

VV.

Account of an Invention to secure the Pannels of Doors and
Window Shutters from being cut out by House-breakers. By
Mr. Joseru Davis, No. 14, Crescent, Kingsland Road*,

Sir,

I HAVE for some time considered, that it would be of Desirable to
great benefit to the public, if a plan could be adopted to pre- Pry bane
vent the pannels of shutters or doors being cut out by house- or shutters
breakers; and having tried a great number of experiments, I 5a ome om
have at length succeeded in accomplishing the one I have the
honour of forwarding to the Society for the Encouragement
of Arts, &c. °

This improvement consists in introducing tempered steel Method of efe
wires through the pannels.and stiles at the distance of three fecting this.
inches, thereby not ouly making a door or shutter far supe-
rior in strength, but calculated to defy the attempts of the
house-breaker in taking out a pannel. ‘This improvement,
though so far seperior to any hitherto known for appearance
and utility, will be attended with less expense. I have sub-
mitted the above plan to Messrs, Paynters, Coleman street,
likewise to Messrs. Moffat and Co. Paternoster row, and to
seyeral gentlemen in that line of business, who all do me the
honour to say, that it far surpasses any thing of the kind, that
they have ever known or conceived, and that it will completely
answer the purpose.

I have also sent the machine on which I bored the pannel,
conceiving it to be an additional recommendatoin; with this
machine, a boy may with ease bore the shutters, &c. which
otherwise might be difficult for a man to accomplish,—~I have
the pleasure most respectfully to subscribe myself,

Sir,
Your very humble servant,

JOSEPH DAVIS.

‘ ® Transactions of the Society of Arts, vol. XXV, p. 101. Ten Gui-
neas were voted to Mr. Davis for this inyention.

You. XXI.—Nov. 1808, N CERTI-

178

Explanation of

the plate,

Principle of a
new €:Cape«
ment,

NEW WATCH ESCAPEMENT.

CErTIFICATE.—We hereby certify, that Mr. Davis’s ime

‘provement on doors and shutters, to prevent the pannels

from being cut out by house-breakers, is the best that we
have ever seen; and we are of opinion, that its being known
will be an advantage to the public, and do therefore recom-
mend it to the Society for the Encouragement of Arts,
Manufactures, and Commerce, for their consideration.

F. Paynter and Co. Coleman street.
E. Cotresacu, Minories.
J. TEASDALE, Paternoster row.
W. Roure.
April 22, 1807.

Reference to the Engraving of Joseph Davis's Invention jor
securing Window and Door Pannels, Pl. V, fig. 5, 6,7.

Fig. 5. Represents a wooden pannel made in the common
way, the dotted lines show the situations of the tempered
steel rods. within the pannel, the holes through which the
rods were introduced on one side being closed up.

Fig. 6. Shows a section of the same, the small dots in the
engraving denoting the place of the rods.

Fig. 7. Shows the instrument on which the bree are
laid to be bored. The borer passes through the holes LM
of the two upright pieces, which keep the borer in a straight
line to act upon the pannel laid upon the frame N.

VI.

Description of anew Watch Escapement. By Mr. S. Munn-
HAM, Counter Street, Borough*.

SIR,

I Beg leave to lay before the Society a model of a new
escapement, the principle of which is, that the balance acts
without friction, and the movement in itself very simple ;

* Trans. of the Society of Arts, vol. XXV, p.108. The silver me-
dal of the society was voted to Mr. Mendham for this escapement.
| ; the

NEW WATCH ESCAPEMENT. 179

the impulse is given without jarring, the inequality of
- power through the train has no perceptible effect on the ba-
lance; and no additional weight, however great, can pro-
duce more than a regular and gentle increase of impetus on
the balance.

I remain, Sir,
Your most obedient servant,

S. MENDHAM.

Sir,

Having attended the Committee upon Mr. Mendham’s Opinion re-
escapement, I think it justice due to a man of genius to SP°uns it
give my opinion farther upon it.

In viewing mechanical improvements, we should not con-
fine our ideas to their present properties, but should consi-
der what improvements the principle will admit of.

As the principles of Mr. Mendham’s escapement, and Compared
that of Mr. Mudge’s, which obtained a bounty from govern- With Mudge’s.
ment, are much the same, I shall compare the one with the
other.

The impulse given to the balance without friction is
exactly the same as Mudge’s. The remontoir is bent up
by the maintaining power in a similar way to that of
Mudge’s, but from the form of the pallet, which is a plain
surface, it is not so perfect. Mudge’s, from the form of
the pallet, bends the remontoir always to the same place,
the other is bent higher or lower according to the force of
the maintaming power, but by forming the pallet like
Mudge’s it would render them alike in this respect. The
only other objection is the spring detent, that detains the
wheel, when it drops from the pallet of the remontoir; it
is the same as that of a detached escapement, consequently
exposed to the whole force of the maintaining power. To
compensate for these objections, the arc of vibration is nat
limited like Mudge’s, which is of great importance, and,
having only one remontoir, it is more simple. It is, there=
fore, superior to Mudge’s in having only one remontoir,
and being unlimited in the arc of vibration; it is superior

eh Beg to

180

Properties of
the inventjon,

NEW WATCH ESCAPEMENT,

to the detached escapement in giving the impulse without
friction.
I am, Sir,
Your very humble servant,

THOMAS RAMSAY.

Reference to the Engraving of Mr. S. Mendham's Escapee
ment, Pl. V. fig. 8, 9, 10,

In the escapement referred to, there are two principal
peculiar properties in the invention, both which I consider
superior to any thing of the kind laid before the public;
first, the balance is kept in motion without any friction
whatever, and in a manner so simple, that even movements
of inferior workmanship must go with great accuracy.

Being not in this line of business, or acquainted with any
persons in the trade, where I might have had an opportu-

nity of examining different escapements, I certainly labour

The impulse

not given bya,

stroke,

’

ander many disadvantages; for since I have been honoured
with the Society’s medal, I have heard of an escapement
by which the balance is kept in motion without friction,
but being limited in the are of vibration, complicated, and
very expensive in the movement, it renders it much inferior
to mine.

In the second place, the balance is kept in action by an
impelling power without any blow whatever; all other es-
capements, which have fallen within my notice, have kept
up the vibration by a direct blow virtually on the balance
itself, which I have always considered to be a great disad-
vantage; for a blow upon any thing of the nature of a spring
produces that kind of shock, which can by no means be
convenient or serviceable in keeping a steady motion, which
is so essentially necessary, but is on the contrary disadvan=
tageous. . ,

¥xplanationof The figure, Plate V, fig. 8, represents the escapement

Ube plate,

without the rest of the train; a a are the two plates of the
frame between which the train runs; 6 is the last, or ba
lance wheel of it, with teeth nearly similar to that of the
balance wheel of an eight-day clock, moving with the flag.

face of the tooth forward against the pallet c of an upright
spindle

NEW WATCH ESCAPEMENT.

gpindle d; e is a locking spring nearly similar to a detached
one, having no extra spring to pass to and fro with. Above
the pallet c, is a very small one, f, which is for the purpose
of unlocking the wheel, which is better shown in fig. 9; at
the lower part of the spindle d, is a hair spring g, so pinned
as to bear the pallet f against the locking spring with suf-
ficient power, so that of its own accord it frees the wheel
and lays the pin 4 which comes through the plate gently up
to the stop, consequently the tooth falls upon the pallet ¢,
but so close home to the centre of the spindle, that it has
no power to pass it of its own accord; the pin / referred to
is fixed to the top extremity of the pallet c, and rises perpen-
dicularly through the plate a some way above the surface.
The balance 2 is fixed on the centre of its spindle, princi-
pally on account of equalizing the weight, beside which it
is the most convenient to be so; it is supported between the
plate a, and the cock k, precisely over the spindle d, conse-
quently the action of each isin the same arch, and the con-
nection is between the pin h of the pallet, and the pin / of
the balance, (a pin fixed in the balance at the same distance
from its centre as the pin h 1s from the centre of the spindle
d, and sufficiently long to-touch the pin h sideways), there
is therefore no friction whatever between them.
Having mentioned the different parts of the escapement,
I shall proceed to explain its action. The immediate course
of vibration is from the spring g. The balance spring is so
placed, that the pin 7 of the balance stands near the pin h
of the pallet. Itis to be remembered, that the tooth of the
wheel rests on the pallet during the vibration of the balance,
so that, when the balance is put in motion, the pin Z comes
in contact with the pin A, which stands perpendicularly
almost imperceptibly fine, and carries it back; as soon as
moved, the tooth of the wheel gives it an extra assistance of
about one fifth of a circle, passes and lays the next tooth
on the lock; on the return of the balance, the spring g ap-
plies all its power in urging the balance forward till it comes
to the stop, the balance then maintains its motion, and the
small pallet f having unlocked the wheel, the tooth falls
again on the great pallet c, and waits the return of the ba-

lance.
° She

18]

Mode of its

182

Assertions ina
foriner paper
verified by fare

ON THE FECULA OF POTATOES, &c.

The balance carrying the piece h back forms a very ad-
mirable banking without any extra apparatus, which is ge-
nerally done by some kind of stop on the hair spring, which
must have an irregular effect; the farther the pin is carried
back, the stronger the spring operates against it, and from
the extent where the piece may be forced back to, there
1s play for near two whole circles of vibration, without any
possibility of upsetting. The balance of the model vibrates
about a circle and one third with extraordinary freedom,
though a course train of four wheels, a large and heavy ba-
lance, with only the power of astout watch spring. I there-
fore think the power necessary to carry a train with this
escapement may be considerably less than any other ofa de-
tached nature.

Fig. 9 represents the axis d shown separately, in order
that the arm and pin A, and hittle pallet f, may be seen more
distinctly.

Fig. 10 shows the balance wheel 6, and the method of
locking and unlocking,

S. MENDHAM.

VIL.

On the Fecula of Potatoes, and some other British Vegeta-
tables. By Mr. WiLLIAM SKRIMSHIRE, Jun.

To Mr. NICHOLSON.
SIR, Wisbech, Oct. 11, 1808.

I Take the li Bru of sending for insertion in your valua-
ble Journal my promised communication on the fecula of
potatoes, and some other vegetables growing ‘in my neigh-
bourhood,

I remain, yours, &c.

Wm. SKRIMSHIRE, Jun.

Since the paper published in the ninety-first number of
the Journal was written, I have verified by the following ex-
periments

ON THE FECULA OF POTATOES, &c. 183

periments two assertions, which were there made, viz. that ther experi-
the quantity of fecula procured from the solanum tubero- ments.
sum 1s inflwenced by the mode of operating, and by the pre-

cise state of dryness of the fecula at the time it is weighed.

In August last, 1000 grains of the young roots of the po- Hundred eyes
tato called hundred eyes, which had not arrived at their full potato.
growth, were grated, and, by the same manipulation as was
employed in the former experiments, ailorded

Grains.
Fine white Ory fecula ++-eessecercecccesoveee g9
MISE LOUTCOMEEINA «ccs cesta c ctiet coe cele cc cee 6
Dry pulp -eeeescccccereccercecsccvevcsces 71
Water, soluble mucilage, and extractive matter 817

ae

1000

ee

The same quantity of these roots being grated and repeat-
edly triturated in a mortar, with frequent eduleoration, and
pressing the pulp with the hands, afforded.

Fine white dry fecula ++-+eeseesseseweeeeeee V1]
Discoloured fecula ---sccccccscccscseoseses FBO
— Dry pulp --ccceceeeeesecscceceecseesecsee 44
Water, soluble mucilage, and extractive matter 825

ee

1000

Thus by greater ‘care and attention bestowed in the last Difference of
process, we gained twenty-six erains more fecula from one ee ne
thousand grains of the fresh root, than we procured ses the care.

first Biethod of operating.

Whien the fine white fecula procured in the last experi- 497 gs. appa-
‘ment was at first separated, it was placed ina window facirig rently dry lost -
the south for two days, exposed to the air, and freqeicnt 16 by heating,
sunshine, until it felt and appeared perfectly dry, it then
weighed 127 grains; but being farther dried upon an iron
plate, with a gentle heat for two hours, and put into the ba-
lance while it was sensibly warm, it weighed 111 grains.

Tt therefore lost 16 grains in weight after it appeared to and then ab-
-be quite dry. It was afterwards placed in a cellar for twelve sorbed 29 from

the air of a cel-
hours, jar.

Lak OW THE FECULA OF POTATOES, &c.

hours, and although it yet appeared dry, it now weighed 130
grains.
Feculaofsome Hence we learn, that dry fecula will absorb more than one
aa baa sixth of its weight from the atmosphere. But it is more
than probable, that this property may vary in the different
species of fecula; for some which was obtained from an
early potato, sudject to a similar experiment at the same
time, did not absorb quite one seventh of its weight from
the atmosphere.
Fecula still left So far is the common process, that is employed for pro-
el fibrous curing the fecula of the potato, from separating the whole
of this principle from the fibrous part of the root, that when
the pulp thus obtained is dried in the air, or by heat artifi-
cially applied, an ounce of it boiled for a few minutes in
twenty-four ounces of water will gelatinize that quantity,
which being sweetened with sugar, and flavoured with a lit-
tle wine and spice, very much resembles sago that is thus
cooked. Indeed it is in my opinion equally palatable and
nutritious with that more costly article of food: for which it
may be economically substituted in every case, and with
every advantage that can be derived from the use cf sago.
cai ae ne For this reason, whenever potato fecula is procured ace
thrown away, Cording to the method formerly described, it will be highly
improvident and wasteful, to throw the pulp away as refuse,
or even to feed pigs with it in its, crude state, as has been re-
commended by some authors; since by being boiled fora
very few minutes only, in a large quantity of water, it is
converted inte the most nutritious food, that any animal can
be fed with, and [have no doubt but it will fatten them as
effectually, and expeditiously, as any other food that is
usually employed for this purpose.
Substitute for If the pulp when first separated, and before it is dried,
rumah were formed into thin cakes, and roasted with a small quan-
tity of oil or butter, in an tron pan, until it is quite brown and
dry, I think it may be used as coffee,.and prove an excellent
substitute for that costly berry. At least it will prove far su-
perior to that execrable trash, which is often vended under
the title of English coffee.
Ihave frequently formed a very grateful and nutritious
beverage from potatoes sliced, roasted to a coffee colour,
then

ON THE FECULA OF POTATOES, &c. 185

‘then ground in a mill, and mixed with a sixteenth part of its
weight of the best Turkey coffee.

That the preparation of vegetable fecula with boiling wa- Useful when
ter will prove the most economical method of fattening pigs, oe pny
I have very little doubt. And ‘perhaps it will be found perhaps other
equally useful when employed for fattening the ruminant #7
animals. However, this isan object worth the attention of
graziers, and others concerned in feeding animals for the

market.

The mode of preparing the food, which I recommend, is Method of pree
as follows. Leet the proper quantity of potatoes be ground, Paring it.
or rather grated ina mill formed for that purpose, in a large
quantity of cold water, which should remain at rest for some
hours, and then be decanted off. The whole sediment, both
pulp and fecula, should be mixed with a proper quantity of
water, and boiled in an iron boiler, frequently stirring it be-
fore it begins to boil. When it has boiled a few minutes,
and is cooled down to a proper temperature to be eaten, it is
fit for use.

Should prejudice prove so inveterate as not to trust to po- Nay pean
tato gruel alone, no one can object to using itas an auxiliary, with other
mixed with barley-meal, boiled potatoes, or pounded linseed sia
cakes,

The increase of nutriment by boiling farinaceous vegeta- Nutriment ix
bles in water is so great, that I cannot refrain from recom- hen by
mending its general use ; being confident, that the advantage i
gained by it will amply compensate fer the labour and ex-
pense attending the operation.

But itis notas a food for quadrupeds alone, that I wish te Recommended
facilitate the introduction of potato fecula. I can safely © ee =e
recommend it as avery palatable and nutritious food for
man. And however the generality of my countrymen may
be disposed to ridicule the notion of being fed upon potato
gruel, I fearlessly recommend the following useful and eco-
nomical preparation of this inestimable root.

The potatoes being grated, or rasped, in a large quantity Useful & ece-
of water, and allowed to stand some hours, the water may hie ns
then be decanted off, and more added, which, atter standing potatoes,

‘an hour or two, may likewise be poured away, and still more
added tf necessary, until it no longer acquires any taste or
colour.

Ss

186

Jelly from it,
soup, & other
preparations,

Useful for the
sick, convales-
cent,
enfeebled, or
children.

Excellent re-
medy for sore
throat.

More elegant
preparation,

Potato starch.

ON THE FECULA OF POTATOES, &c.

colour. The whole fecula and pulp are then to be well
mixed together, formed into small cakes, and dried in the
air, or by a gentle heat. This is a preparation, which will
keep for many years—which no family ought to be without,
and which is in the power of the poorest family to possess.
Half an ounce of this preparation will gelatinize so large
a quantity of boiling water, as to afford a sufficient meal for
any labouring personin health. It may be sweetened either
with molasses or sugar: or being boiled with an onion and
pot herbs, and seasoned with pepper and salt, it wili makea
very palatable, wholesome, and nutritioussoup. But should
the raw flavour of the potato predominate, as will sometimes

happen, when the preparation is newly made, it may be cor=-

rected, and the soup improved, by the addition of a little
mushroom catsup, allspice, anchovy, or red herring.
If this preparation of the potato be boiled with milk,
sweetened with sugar, and flavoured with a little wine or
spice, it forms the most nourishing and restorative food, that
can possibly be administered to the sick and convalescent.
It is so easily digested, that it soon becomes animalized,
even by the impaired functions of a debilitated constitution.
Thus it is peculiarly fitted to the digestive organs of the de-
bauchée, and to the languid powers of infancy. And I have
known infants wholly nourished for months by this prepara-
tion, boiled in milk and water, sweetened with a little sugar,
With a larger proportion of the preparation a stiffjelly may
be formed, which acidulated with lemon juice, or any other

vegetable acid, becomes the best domestic remedy that can

be employed, in every species of sore throat.

» Those who can afford it may have a much more elegant, |

though rather a more expensive article, in the pure fecula
itself, deprived of all the pulp and fibrous part of the po-
tato. This preparation is so easily made, that I hope to see
it introduced into general use. And I do not hesitate to
say, it will be found superior in every respect to salep, sago,
arrow root, or any of the vegetable preparations of that kind,
which have been so pompously advertised, and recommend-
ed to the publie, by those who are interested in the sale of

them.
Indeed it is already generally known to laundresses under
the

on

ute >
o

ON THE FECULA OF POTATOES, &c. 187

the name of potato-starch, and they are no strangers to the
method of procuring it from the fresh root; but they are
not sufficiently aware of the nutritious property which this
substance possesses. And it is principally with the view of
making it more generally known, that I am induced to lay
before the public these experiments and observations*,
It will appear ludicrous to many, to assert in the present The science of
age of the world, that the science of nutrition is yet i its in- pei litle
fancy; but truth obliges us to confess, that such is abso- :
lutely the fact. The cause of our ignorance it is not my
_ intention to investigate.

It is, I believe, a general opinion, that the nutriment of Cookery.
our food, especially the vegetable part of it, 1s greatly in-
ereased by cooking. This is therefore an art, which claims
the attention of the whole human race. It is an art, so inti-
mately connected with the welfare of our species, that it is
absolutely essential to its existence, in a state of civilized
society.

In the present tottering state of the Lavoisierian doctrine Water essen-

_ of chemical science, it is fortunately of no consequence to ere mutri-
our subject, whether water be a compound substance or a *
simple element. And we have no fear of contradiction when
we assert, that it is essential to the nutrition of animals, as

- well as of yegetables.

When water in its simple state is taken into the stomach In its simple
along with our food, its principal effect in assisting digestion *tte assists die
5 : a gestion mechae
is perhaps mechanical only, by giving the food a certain de- nically
gree of consistence, most favourabie for the gastric fluid to
act upon it, and according to Mr. Home’s late important
discovery, the superfluous quantity is conveyed mto the
circulation by the intervention of the spleen*. For as the
whole internal surface of the stomach is endowed with the

*® Many years ago an article was sold in canisters by the name of sago
powder, which I believe was chiiefiy if not solely made from potatoes:
but it fell into disuse, whether from prejudice alone, or from negligence
in preparing it, I cannot say. 1 also remember the fecula of potatoes be-
ing strongly recommended as a substitute fur salep, particulariy as keep-
ing better, as well as for sago, by a writer in the Journal de Méde-
cine. C.

® See Journal, p. 103 of the present vol., and p.347 of vol. KX,
3 power

188 ON THE FECULA OF POTATOES, &c.

power of producing a secretion, which possesses the property
of coagulating albuminous fluids, before the organ is ena<
bled to convert them into chyle, we have some show of rea
son for supposing a certain degree of consistence in the con
tents of the stomach to be most favourable, if not absolutely
necessary, to the healthy action of the digestive organs.
But when che- But when water is gelatinized by its chemical combination’
eure ay with fecula and heat; there is considerable reason to believe,
cula becomes that even the whole of its particles become animalized by

animalized. ‘the efforts of the stomach. ‘The importance of this idea is
such, as to require it to be impressed upon the minds of all,
who wish to study the science of nutrition.

Thosesubstan- If therefore the digestive organs have the power of ani-

ces most use- malizing water, after it has acquired a certain degree of con-
oe bony! cia sistence, by boiling with fariaceous vegetables, or other
ter. substances, we may conclude, that these preparations of ve
getables, which in the process of cooking are enabled to
consolidate or rather to gelatinize the greatest quantity of
water, will be found to afford the largest portion of nutri-
ment, and are consequently the most beneficial to mankind.
Potato fecula It is from these considerations, that I am induced to re-
recommended. commend in the strongest terms of approbation the use of
potato fecula, as being by far the most economical method
of employing this inestimable root.
Conan From what has been said above, concerning the nutriment
starch not to of potato starch, I do not wish it to be understood, that the
be taken as aude
food, common starch of the shops may be administered as food
with impunity. For common starch, after having under-
gone a slight fermentation, which is sometimes produced by
the addition of impure and nauseous ingredients, is still far--
ther contaminated by a metallic oxide, which is probably ini-
mical to the human constitution.
It is for this reason, I wish to retain the name of fecula,
instead of starch, as a generic term for this vegetable prin-
ciple. ,
Fecula from Reflecting upon the nature of this vegetable product, and
various vegetae considering it is equally the produce of seeds and roots, and
bles, ay : ae .
that, if it be procured with care, it is perhaps equally nutri-
tious from whatever plantit is obtamed ; whether it be in the
form of fecula fram the wheat of Great: Britain, or in that
of

ON THE FECULA OF POTATOES, &c. fg

of Cassava from that deadly poison the Jatropha Manihot of
North America; I was induced to suspect, that some other
British vegetables, both indigenous and naturalized, might
be rendered much more serviceable to our species, than they
are at present supposed capable of becoming,

With this view I selected the following,

1. Hsculus Hippocastanum, or Horse Chesnut.

Of the fruit of this tree, fresh-gathered, peeled, and skin= Horsechesnut,
ned,
1000 grains, rasped in water with a coarse file, afford

Grains.
Fine white dry fecula .sssssveeseseeesseeess 200
Discoloured or yellowish fecula--.+-++2++++++ 32
Dry pulp cece c cece sceseeceeserceeeeeerers SQ
Water, soluble mucilage, oil, and extractive mat-

TEL coerce cccsese reser econ pe eget ce roreee 688

eee

1000

ot

Thus we find the fruit of the horse chesnut contains more
than one fifth of its weight of fecula, the whole of which is
converted into animal matter, in the process of digestion!
We may therefore, in a time of scarcity, accept with grati-
tude another rich and wholesome fruit, which has hitherto
been held in little estimation.

And indeed at a time when there is no scarcity, those per=
sons, about whose habitations this handsome tree is found to
flourish, may profitably employ its fruit in the manner here
pojnted out.

2. Quercus Robur, Common Oak.

The acorn affords a considerable quantity of fecula, but 4 coms,

its colour, which is a dirty light brown, similar to powdered
salep, will always detract from its value, and prevent its in-
troduction to general use, so long as a more elegant article
can be procured with equal facility, and at the same ex-
pense. However, I am fully persuaded its colour does not
injure its nutyitive property,

1000

190 ON THE FECULA OF POTATOES, &c.

1000 grains of this fruit fresh gathered, and not quite
ripe, when peeled and skinned, afford
Grains
Dry brown fecula -essseeecsrrecececeseees 165
Dry pulp corer eee eserccceseesrceseeseeeses 150
Water, soluble mucilage, oil, and extractive
Matter cocvescccsreccrrevscrvescvesecse O85

eel

1000

festa

3. Bryonia dioica, Red-berried Bryony, or as it ts vulgarly
. termed, Mandrake.

Root of Red- This plant, which is common in this neighbourhood, has
ee’ a very large, thick, white root, and although it is one of the
most violent drastic cathartics, which this kingdom produces,
it may, by a similar process to what we have before described,
be made to afford a very fine white nutritious fecula, m

great abundance.
1000 grains of the fresh root dug up early in May, afford

Grains.
Dry white fecula eoeeereecece eee ee PERA FS O80 5Q

Discoloured fecula eoeoene eee eeseoece eee eeeete 45
Dry pulp ecsccccceccccccercecvccecescnces 50
Water, soluble mucilage, and extractive matter 855

ood

1000

ore,

4. Arum maculatum, Cuckow-pint, or Wake Robin.

The root of this plant, which is very plentiful in my-
Root of arum, ; Z
cuckow pint, Beighbourhood, although one of the most acrimonious ve-
or wake robin. setables of British growth, may, by particular management,
be converted into a very rich, wholesome, palatable, and pro-
ductive food.

It is excellent, eaten either boiled or roasted, particularly
by the latter mode of cooking. If formed into vermicelli,
itis a beautiful preparation. When dried it may be made
ito bread; and when treated according to the method
above mentioned for procuring fecula,a much greater quan-

tity

ON THE MEIONITE. 19]

tity may be obtained, than from any vegetable hitherto ope-
rated upon*.
1000 grains of the fresh root, dug up early in May, afford

Grains,
Very pure white dry fecula «++sesesseeesers 954
Dry pulp ---cseccoecesccccnvecccsrcescees 28
Water, soluble mucilage, and extractive matter 718

See

1000

——=

The more we reflect upon the general diffusion of this Fecula very
nutritious principle throughout the vegetable kingdom, the generally dif
greater occasion have we to be seriously and unfeignedly
thankful to that Almighty Being, whose extensive benevo-
lence has thus bountifully placed within the reach of man a
sufficiency of nutriment, in every corner of the Earth !

VIII.

Remarks onMeionite, with some Observations on a Paper by
Mr. Freperic Mons, in which this Substance is considered
as a Variety of Feldspar. By Mr. Tonnewier, Keeper
of the Cabinet of Mineralogy to the Council of Minest.

D OES the mineral mentioned by the name of meionite Is meionitea
in the Tableau méthodique of Mr. Haiiy constitute a distinct ae ot
species, or is it merely a variety of some species formerly
known? Such is the question, that suggested itself to me,
on reading a paper by Mr, Frederic Mohs, lately inserted

* The root of this plant has been employed for making starch in the

island of Portland, from time immemorial. Some years ago the Society

of Arts gave a premium toa person of thatisland for an account of the
process, with a specimen of the starch.

t+ Journal des Mines, vol, XX, p, 165.
ia

19%

First noticed
by Romé de
Plsle

as a jacinth
with some
other substane
ees.

hese separae
ted imto four
species by

Blaby,

ON THE MEIONITE.

in the Ephemerides of baron Moll*, and which I shail here
attempt to answer.

For our first knowledge of this substance we are indebted
to Romé de V’Isle. This philosopher, guided by the ana-
logy of the figures of their crystals, has united under the
name of jacinth, in the second edition of his immortal work
on crystallography, severak substances, that now form dis-
tinct species. ‘These however he was far from considering
as the same, though he did not think proper to distinguish
them by different names, which he must have invented for
the purpose. In the description he has given of the second
variety of the jacinth the dioctaedral variety of the meio-
nite is easily recognized, Beside its locality in the lava of
Somma, and the white colour of the mass, which are pointed
out, it is there said, that the two quadrangular pyramids of
the jaciuth, the primitive zircon of Haity, are separated
by a prism of eight unequal faces, alternately hexagons, and
rectangular parallelograms; and that the latter of these,
produced by the truncation of the edges of the prism, some-
times very narrow and scarcely perceptible, and at other
times more or less broad, always answer to the faces of the
pyramids; while the hexagonal sides of the prism are al-
ways intermediate to these faces: circumstances that agree
perfectly with the dioctaedral meionite. See pl. 6. fig. &.

Mr. Haity has made four species of the substances de-
scribed by Romé de I’Isle. | )

1. The zircon (the jacinth and jargon of former miner
alogists), divisible into an octaedron with isosceles triangular
faces, which may be subdivided parallel to planes that would
pass through the summits and edges of the faces.

2. The harmotéme (cross-stone, crucite, andreolite of the’

Hartz, staurolite of Kirwan), divisible into a rectangular oc

taedron, subdivisible on the edges contiguous te the sum+

mit.

3. The idigcrase (vesuvian of Werner, jacinth of volca-
canoes) divisible parallel to the faces and diagonals of a
right prism with square bases, differing little from a cube,

* Ueber Haiiy’s Mejonit, von Friedrich Mohs: in the Efemeriden der
Berg- und Hiittenkunde, herausgegeben von Carl Ehrenbreit Freihergn
von Moll. Band JI, Lieferurg1. Nurnberg, 1806,

4. The

ON THE MEIONITE, 193

4, The meionite (Romé de I’Isle’s white jacinth of Som-
ma), divisible parellel to the faces of a right prism with
square bases. Tig. 4.

In characterising these species the learned author of the on the princi-
Theory of the Structure of Crystals has merely applied the ahaa
general principle, that has served as the base of the classifi- him,
cation of the species in the system published by him. On
this occasion he had followed the same course, as he had
pursued when he separated the heterogeneous substances
of which the former mineralogists composed the species they
termed schoerl, in order to make a proper distribution of
them, or when he demonstrated four distinct species to have
been confounded together under the name of zeolite. In
short, to constitute the species meiomite Mr. Elaity has em- and the results
ployed the means, of which he has so successfully availed cee
himself to effect those useful reforms, for which mineralogy is adopted.
indebted to him, and the result of which has been a more pre-
cise definition of species, witha more regular classification of
subjects. The title that meionite has to be admitted into
the system as a species therefore is equally incontestible
with those of several other species established by the same
gentleman, and generally adopted.

Among those who come to study the mineralogical col- What is the
lection of the council of mines, which adds to the means of Weener's ake
jnformation derivable from the number and variety of its tem? ‘
specimens the advantage of being able to compare the me-
thods of two of our greatest masters, several have put to
me the following question: ‘© What species in Werner’s
system corresponds with that which Haiiy has designated
by the name of meionite?” Hitherto I had been unable to
answer this question, notwithstanding the pains I had taken
to procre the printed or manuscript syllabuses of the
mineralogical lectures delivered at Freyberg. On the one
hand I could uot suppose that the meionite, which is at pre-
sent to be found in all public and private collections, should
be wanting in that of Mr. Werner; and on the other hand,
in th. .eries of famil es g ven by tha: lustrious professor,
into wh ch are adopted withou any change i name several
species established by the celebrated professor of the Museum
of Natural History at Paris, there was no mineral that I

Vou. XXI.—Nov. 1808. O could

194 ON THE MEIONITF.

could take for the substance in question. I remained in
this uncertainty, till I had read the paper of Mr. Mohs, in
He suspects it which we are informed, that Mr. Werner had not yet adopted
to be only a va- the meionite of Haiiy as a distinct species, suspecting it may
riety of feld- | : é - ied -
spar be nothing more than a simple variety of feldspar. Now the
object of this paper is to demonstrate the reality of what is
but a simple conjecture on the part of a naturalist, whe
knows when to doubt, and when to decide. On reading it
with that double attention, which the name of Werner and
the talents of Mr. Mohs would naturally inspire, I felt i
spite of myself the regret of not being able to embrace the
same opinion respecting the nature of the mineral that
forms the subject of the present paper.
They do not Mr. Mohs admits, that the characters taken from figure
agree im AgUres echibit great differences between the meionite and the feld-
spar; and he confesses, that these differences are little capa-
oe ce ble of being reconciled: but, as he thinks it not altogether
to one Sig f impossible, to reduce the forms of the meionite to a very:
mon form. simple form, which he has observed in the series of forms
presented by feldspar, he has flattered himself with beme
able to justify completely the suspicion of Mr. Werner.
The geometrical form in which he gives the proofs alleged
in his paper has enabled me to combat them with the same
weapons. 1 appeal therefore to these geometrical reasons,
which are employed with the more propriety in the present
case, because it is only by the help of the nicest precision,
that an able hand has traced the line of demarcation between
the meionite and other species of the mineral kingdom,
A species can ‘It isa principle generally admitted, even by the confession
ee ak oath of Mr. Mohs*, that in a mineral species there can be but °
andits inte- one primitive form, and one single form for its integrant
ang molecules. To prove therefore, that the meionite cannot
be avariety of feldspar, it is sufficient to demonstrate, that
the primitive forms and integrant molecules of these two
minerals are very different.

ait

* ¢¢ Es ist ein grundsatz dass in einer gattung nur cine kerngestalt, und
nur eine integrirendes molecul, vorkomnien koennen ; und der orictog-
nost....traegt kein bedenl.en diesen grundsatz in seiner yollen allge-
meinheit gelten zu lassen.” Ephemerides of Baron Moll, Vol. II, Part

I, p. 15, 1806.
I. Fchi-

ON TILE MEIONITE. 198

I. Feluspar.

The primitive form of the feldspar, according to Haiiy®, Primitive form

is an oblique angled parallelopipedon, in which the angle of o feldspar.
incidence between M and P is of 90°, that between M and
T of 120°, and that between T and P of 111° 28’ 17” See
in fig. 1 this solid represented in the position given it by Mr.
Mohs himself, as being favourable to the comparison he
makes of the two substances. Mr. Haity observes in his
treatise, it is true, that the sections parallel to M and P are
very clear, and very easy to obtain; while that parallel to T
siinply shows itself by a changeableness of colour in a strong
light. Since the publication of this treatise however, this
gentleman has. obtained from the feldspar, by mechanical
division, nuclei presenting the joint parallel to T in a very,
clear and decided manner, which he has publicly shown in
his late courses of lectures, and some of which he has dis-
tributed among his auditors,

The primitive form of the Feldspar once thorovghly as- Can the forms
certained, it remains to be known, whether, setting out from ofthe meionite

3 : : be produced by
this nucleus, we can obtain by the laws of decrement the any decrement
forms of the meionite. But the mere inspection of the o this:
crystals shows at once the impossibility of this. In fact, the 2
meionite has the four faces of its summit equally inclined
to each other and to the lateral faces, Now this symmetry,
is incompatible with any primitive form but a prism with
square bases, as in the mesotype, or a rectangular octaedron,
as inthe zircon; both which species exhibit forms analogous
tothose of meionite, but with different incidences. It is al-
together the reverse with the forms of the feldspar, which
bear in some sort the impression of the irregularity of their
primitive form in the want of symmetry of the faces arising
on parts similarly situate. The following details appeared to
me necessary, to place this proof in a clearer and stronger

Fig. 3 represents one of the forms of feldspar, in which Two crystals

y most fayoura-
the faces M, P, T of figure 1 are preserved, and the face O ple to the sfip-

F : ae position taken.
results from the decrement -> according to the position the

O02 nucleus

# Traité de Minéralogie, tom. 2, p, 591.

196

These do not
agree,

ON THE MEIONITE.

nucleus has here. Mr. Mohs has chosen this form among
all those of the feldspar, as being the simplest, and best
calculated to lead to the object he had in view, the reduction
of the forms of the meionite to those of the feldspar, On
the other hand fig. 4 represents the dioctaedral meionite. It
now remains, to compare these two forms together; and this,
I must apprise the reader, is the essential point of the dis-
cussion.

Mr. Mohs, having measured the angle of incidence be-
tween T and P in the crystal of feldspar fig. 3, found, that
it agreed manifestly with that between / and M in the dioc-
taedral meionite, fig. 5. In fact we find by calculation a
difference of 21’ only between these angles; the first bemg
111° 28’, the second 111° 49’. But on proceeding with the
comparison, instead of evident resemblances, we have no-
thing but striking differences. For instance, the angle of
incidence Wureoin Zand each of the two sides M, M, is the
same; while that between T and M, fig. 3, differs 8° 32’ from
that between T and P, since it is of 120°. On the other
hand, the angle between O and M is of 116° 21’, and that
between O and the face opposite to P is of 124° 15; yet
each ought to be of 111° 49’ for the form of the meionite to

7 agree with that of the feldspar. It is the same with all the

The mesonite

other faces, that can arise on the edges or angles of the face
T. There are none similarly situate but the faces analo-
gous to M and §, fig. 5, the angles of incidence of which
are 90°and 135°. But this is only an accidental resemblance
owing to the symmetrical position of the lateral faees in the
two nuclei; otherwise we might say, that feldspar is an ore
of oxide of tin, since the same angles of incidence are found
on the prism of the latter. As to the essential difference
between the’ summits of the crystals of feldspar and those
of the serystals of meionite, this is owing, as has already
been’ ‘Observed, toa want of symmetry im the positions of
the bases of the nucleus:with respect to the lateral faces,
which does not allow the faces produced, in consequence of
the laws of decrement, to preserve that regularity with re-
spect to each other, which appears in the terminal faces of

the dicctaedral meionite.
So far then from acknowledging with Mr. Mohs, that we
meet

ON THE MEIONITE. 197

meet with no crystalline face in the meionite, the inclination not deducible
of which does not occur among the forms of feldspar, we Sere eee
will venture to request that gentleman, to endeavour to de- feldspar.
rive the figure of the dioctaedral meionite, represented fig.

5, from the primitive form of the feldspar, so that the angles

of incidence between all the contiguous faces shall agree

exactly ; I say, exactly, for in such cases every thing de-

pends on precision; and he will soon convince himself of

the impossibility of succeeding. Now this consideration This decides
alone is sufficient, to set aside for ever the idea of uniting the ai ac
meionite with the feldspar, and decides the question beyond

dispute.

The author of the memoir, after having asserted, that all Difference as-
the faces of the meionite may exist in the feldspar with the ee Wee org
same inclinations, finding that the angles of incidence men- rours in mea-
tioned by Mr. Haiiy differ evidently from each other, as- S" ing.
cribes this difference to erroursin the goniometer, and a want
of agreement in the data; and he leaves it to the skilful
oryctometer, to remove the difficulty that this want of har-
mony presents. But the crystallographer finds nothing here But the form
to reconcile, since every thing is regular in each of the two ren ae
crystalline forms. The incidences of the faces have that re- and eect
lation to the primitive forms proper to each species, which -he theory.
calculation, agreeing with observation, indicates in a precise
manner by virtue of certain laws of decrement. If the angle
of incidence between T and P approach that between / and
M; if those between O and M and O and P differ from the
latter, as well as from each other; it is because the form of
the integrant molecules and the laws of decrement require
it. These laws have been determined with the more cer.
tainty, as there has been no difficulty in procuring well de-
fined crystals of feldspar and meionite. They who are fully
acquainted with the theory of Haiiy, and at the same time
know the precisian, with which he applies it, see no difficulty
jn the case. They know, that the angles are rigorously de-
termined by calculations founded on certain laws of decre-
ment, the truth of which is in turn confirmed by the agree-
ment of observation with calculation; and they require no
more.

One example will be sufficient, to give an idea of the ac- Ins:ance of the

curacy

198 ON THE MELONITE.

nicety of Mr. curacy of the measures given in the work of Mr. Haiiy. It is
rig elas in p. 39 of the first volume of his Traité de Minéralogie.
Among the number of forms exhibited by sulphuret of iron
Dodecaedral may be observed the dodecaedron with pentagonal faces,
ae of This crystal is divisible parallel to the sides of a cube; which
is the form of its nucleus, and at the same time that of its
integrant molecules, woich perform the functions of sub-
tractive molecules. On each face of the primitive cube two
simultaneous decrements are supposed to take place in the
additional lamin; one of two rows in breadth, setting
out from two opposite edges; and one of two rows in
height, setting out from the other two edges of the same
face. The decrements that take place on the faces contigu-
ous to the nucleus follow the same laws, and in directions
crossing each other, so that the slower decrement on one face
answers to the more rapid decrement on that contiguous to
it. The nature of the decrements, added to the aipetion
of the laminz, gives rise to a new polyedron; the faces of
which, becoming level with each other in pairs, are reduced
to twelve, instead of twenty-four. The sulphuret of iron has
assumed the form of a dodecaedron with pentagonal faces.
But it is possible to conceive an infinite number of these
dodecaedra, by varying the respective angles of incidence of
the contiguous pentagons. What then is the dodecaedron of
Not the regu- the sulphuret of iron? is it the regular pentagonal dodecae-
rssicon dren of geometricians? So two learned natural philosophers,
posed by Wer. Werner and Romé de I’Isle thought: but it is strictly de-
ner andVIsle. monstrated by algebra, that such a polyedren cannot result
from any law of decrement. The angle of incidence be-
tween two contiguous pentagons at a given edge common to
both alone determines all the other angles; and it is demon-
strated algebraically, that, in the case of decrement of which
we are speaking, this angle must be 126° 52° 8”. Now, on
measuring with the goniometer the angle that occurs in the
sulphuret of iron, it is found to be nearly 127°; and from
this agrement of the calculation with what is actually ob-
served I infer, that the existence of the law of decrement is
confirmed. Such is the rigorous method, in which Mr.
Haiiy constantly proceeds, when he applies his theory to the
structure of crystals, to determine species in mineralogy.
Il, Meionite.

ON THE MEIONITR. 199

Il. Meionite. .

Mr. Mohs has attempted to raise doubts respecting the Meionite.
primitive form of the meionite, which he is desirous of as-
similating with that of the feldspar: but recent observations
made on specimens lately brought from Vesuvius, very well
murked and of a good size, have confirmed the angles,
both of the primitive and secondary forms, to be the same
as given by Mr, Haiiy in his Treatise on Mineralogy. This
gentieman, having broken crystals of this substance, has
perceived joints parallel to the base, the position of which
was at first merely conjectured. These joints, it is true,
are not so clear as the lateral joints; but this is agreeable
to the theory, which, giving a more extensive surface to
the bases than to the sides, explains why the sections paral-
lel to the bases are less easy to‘ hit upon than those of the
sides, where the points of contact are fewer. :

I have yet compared the meionite with the feldspar only Other charac-

‘in respect to form; but there are other characters, such as pie
specific gravity, hardness, lustre, fusibilty, &c. The me- Haiiy.

thod of Mr. Haiiy, which is not purely orctometrical, far

from excluding these, calls them in to the assistance of the

- geometrical characters in determining the species. Now

Mr. Mohs says*, if the crystalline forms appear to militate

against the union of the meionite with the feldspar, the

other characters taken together will not allow us to part

them: otherwise the method ceases to be natural, since it

separates what nature has united.

I shall not stop here to discuss the greater or less resem- The resem-
plance ascribed to the physical or chemical characters of ae pe
the meionite with those of feldspar; a resemblance, which asserted.
does not appear to meso great as is said; for on the one
hand the meionite is strongly scratched by many pieces of
feldspar, and on the other, the latter does not melt before
the blowpipe like the former with ebullition accompanied.
by a hissing noise, as has been observed by Mr. Leliévre,
member of the council of mines, who is known to be very

*® Page 16 of the paper already quoted,
‘ expert

900 ON THE MEIONITE.

Theformalone expert in this kind of proof, In the present case, the chae
sufficient to . :
decide the | racter borrowed from the form is sufficient. In fact, ac-
point. cording to Mr. Mohs, only one primitive form can exist in a
species: but the primitive forms of the feldspar and the
meionite are distinguished from each other in all the forms
with which we are acquainted : their dimeusions have been
ascertained by a rigorous theory, the accuracy of which is
proved by the agreement of calculation with experience.
These alone therefore suffice to distinguish the species: if
they did not, they might agree with other species, the forms
of which would be different, and then one species would
have two different forms, which is contrary to the hypothe-
Principle of sis, and implies a contradiction. Here we see clearly what
beard mes distinguishes the method of Mr. Haiy. It is founded on
the smallest member of characters possible. ‘That which is.
taken from geometry, which is precise, is always employed, °
and frequently alone. When the primitive form obtained
by mechanical division is a limit, that is to say, a regular,
or at least a symmetrical solid, some other character must
be added, since it may agree with several species. How-
The geometri- ever, it is not necessary to determine the molecule of a mi-
ve Sor vmieal neral, in order to find to what species it belongs. This is a
to the student. Jabour requisite only to the author of the method, who can-
not employ means too precise for the determination of spe-
cies. He whose object is merely to ascertain the species of
a mineral, will find in the method of Mr. Haiiy more ma-
nageable characters, that will euide him to his end.
Conclusion. From the details into which I have entered it will be evi-
dent to all, who are acquainted with the theory of Mr. Haiy,
that the forms of the meionite are incompatible with those
of feldspar, that the integrant molecules of the two differ
essentially from each other, and, in fine, that these two sub-
stances ought to remain separate in the mineralogical ‘syse
tem,

ON REFRAcTIoN, &c. ~ 201

IX.

Method of finding the Quantity of Refraction from the Dis-
tance and Altitude of two known Stars; and of solving by

- Construction a Problem in Spherical Trigonometry. In a
Letter frum a Correspondent.

To Mr. NICHOLSON.

SIR,
‘Tue following method of finding the quantity of the re- New method
fraction by observing the distance ‘nid altitudes of two known Rrra
stars is, as far as I know, new: and as it seems to possess fraction.
some advantages over the common methods, I will venture
to request its insertion in the Philosophical Journal.

Let Z, Pl. VI, fig. 8, be the zenith, S and X the appa-
rent, s and x the true places of the stars.

Let d be the difference between their trne and appa-
rent distance; then Ss the refraction of the star S —
dX tang. ZS xX cos. MS x cos. M X

S.SX x rad.”

Demonstration.

i grcrident that d{ ——X m+ Sn) Some SE See Demonstration,

cos. £5 X Ss (xm and sn being perpendicular to S X); but

Ss:Xax::tang. ZS:tang. ZX. Xx = 2X tang ZX,

>

tang. ZS
co oe 23 a cos. ZX X tang.
hence by substitution we get d=Ss Ja ae as
ZX + cos. ZS x tang. ZS. Ty ae ae cotang. ZX
" % rad. f Bay ra
tang. M ts tang. MS
ie TE and cos, § = SSS & tang: BS » hence
ove tang. MX + tane. MS
by substitution, d=Ss x PT eee LS. Gime but

sum of tang. : S. of sum::rad.”: 0 of cos. 7. e. tang. MX
ae MS:S.SX%::R’: cos. MX x cos. MS; hence
fl ae

QOD

Choice of the
Stars,

&dvantages of
the method.

Problem. The
sides of a sphe-
tical triangle
given to. find its
angles.

Demonstration,

Extension of
the problem.

ON REFRACTION, &c.

Ss x8. SX x rad.2 :
cos. MX x co. MS x tang. ZS and Bop=
dX tang. ZS x cos. MX x cos. MS
rad7 x S. SX

FD.

The stsrs should be chosen so as to make the angles §
and X acute, as the cos. of an obtuse angle would be ne-
gative. :

The advantages which this method scems to possess over
those which are already in common use, are, ist, that only
one observation is required, as the refraction may vary con--
siderably in the interval between two observations; and 2d,
that it does not require the latitude to be known, and that
the observation may be taken at sea with the instruments al-
ready in common use for lunar observations.

The following method of solving by construction a. pro-
blem in spherical trigonometry may possibly be new, and
worth your insertion.

Given the sides of the spherical triangle ZS X, to find
anangle Z. Let MI and MV (fig. 7) = the secants of
the sides ZS and ZX, including the required /, take the
41M V = the remaining side; let 1Z,ZV = tangents
of the sides ZS and ZX, and the ZIZV will be = the
required Z Z,

Demonstration.

Let M (fig. 6) be the centre of the sphere, jon M Z,MS§,
MX; draw ZT and Z V tangents to ZS and ZX; hence
MT and MV are the secants of those sides, the ZTZV
=S ZX, and the ZM =the side SX. Hence supposing
the triangle T ZV to come into the same plane with TMV,
the two triangles will coimcide with fig. 7.

Q. E. D.
It is evident, that the cases of two sides and an included
angle being given to find the third side, and of two angles
and the side included to find the third angle, may be solved
by a similar construction.
Yours, &c.

J, B.

Nichelsons Philos, Journal; VAXKT PLP. ji.2a2

OS ie cae
Or FOC Mean Toc UMW

A 4ig.4 +

\ Sins
; ; ase! MS |
\ a tit 4 f j8|M /Ss |M
\
\ | |
bs at
\ Zz
3 \

ee

oe
Bf mW UN

FEMALE ALBINO,

X.

Early Account of an Albiness. In a Letter from Joum
Bostock, M.D.

To Mr, NICHOLSON,
SIR,

Ix examining lately one of the eartier volumes of the Phi-
Joso: hical Transactions, I meet with the following account
of an albino, which, as the subject has lately engaged your
attention, I have transcribed for insertion in your Journal.
it may be thought enrieus, both as being perhaps the ear-
liest account on record of this peculiar variety of the hu-
man species, and also as furnishing another example of its
occurrence in a female. It is taken from a paper on mon-
_ gters, In the 25th volume of the Transactions, for the years
1706, and 1707, bearing the following title. ‘ De mon-
‘s stris, quasi monstris, & monstrosis; item de serpentibus,
«© & Phillippensibus, ex M. S. R. P. Geo. Jos. Camelli.
* Communicavit D. Jac. Petiver, Pharmacop. Lond. &

*« §.R.S.” It is divided into sixty-nine sections, each of

which contains a narrative of some uncommon or monstrous
production. The account of the albino is placed under the
head of “ Monstra que existebant, A. D. 1700 in insula
Catanduen.” “ Albinam, Hispanis Albinno, vidi Manil-
‘* Jz; erat puella decennis, (proles Morenorum parentum,
*¢ qui coloris sunt fuliginosi, sed capillitio protenso) albedi-
‘© nis extraordinarie & insolite in admirationem trahentis,
« & monstruosz, capilli aureoli, solem ac lucem invite
« ferens. Causam vulgus non phantasiz sed lune influxui
* tribuit*.”

# <¢ Monsters existing in the year 1700, in the island of Catandu-
anes.

* T saw at Manilla an albiness, called by the Spaniards an albinno. She
was a girl ten years of age, the daughter of negrello parents, who are of a
sooty complexion, with very long hair. ‘She had an extraordinary, un-
common, wonderful, and unnatural white skin, golden hair, and was im-
patient of sunshine or light. The commen people ascribe this not to the
imagination of the mother, but to the influence of the moon.” C.

If

203

Early account
of a female ais
bino.

204

Extraosdinary

ON THE DOCTRINES OF CHANCE.

If we except the concluding hypothesis, the account is
probably correct ; the extraordinary whiteness of the skin,
and the great sensibility to light, are well characterized, and
precisely resemble what fall under our own observation. [t
is indeed upon the antecedent probability of the narration,
and not upon the credibility of the narrator, that we are to
ground our belief; for many of the stories are palpably false
and fabulous. The following may be taken asa specimen.
A white woman brought forth a child the colour of a negro;
the prudent midwife suspecting it to be the effect of. some
unsatisfied longmg of the mother, found upon inquiry, that
she had longed for some sardines (a peculiar kind of fish)
that she had seen eaten by a black woman. Taking there-
fore the bones and remains of the fish, she rubbed them orer
the mouth of the infant, and immediately the dark colour
was removed, and a white complexion produced*.

Lam, Sir,
Your obedient Servant,

Clayton-Square, Liverpocl, J. BOSTOCK.
Ocr. 2d, 1808,

XI.

Remarks on the Doctrines of Chance, in Answer to Opsimath,
in a Letter from W. Saint, Esq.

To Mr. NICHOLSON.
SIR, Woolwich, Sep. 19, 1808.

I Read in the 91st number of your Philosophical Journal
the letter of Opsimath, containing his ‘ scruples as to the

* Tam inclined to think this account not altogether fabulous, though
the assigned cause, and the remedy prescribed, are both palpably absurd.
In some instances of difficult labour, the face of the child is so black, lips
swelled, and nose flattened, that ‘when born it resembles a young negro $
but these appearances soon go off of themelves. Such was probably the
case here; and the sagacious midwife applied her remedy time enough,
to giveit the credit of effecting the removal of what had probably excited
astonishmnet and alarm. C.,

truth

ON THE DOCTRINES OF CHANCE. 905

truth of the elementary doctrines of chance,” should you
think the following remarks upon the subject likely to re-
move the doubts of.your correspondent, you will, by. their
insertion, oblige

Your very humble Servant,

W. SAINT.

Opsimath begins by quoting what he deems to be the Sense of the
sense of the first case of de Moivre in these words, ‘* Any pea ci
“ one undertaking with a die of six sides, to cast an ace in one
“© throw,has 1 of the six possible chances in his favour, and the
“remaining 4 against him; the whole six chances Leing cer-

* tainty or at least such in ihe event of continued trials.” Now
this latter clause of the supposed quotation (I say supposed yy;. cong
quotation, for Opsimath confesses, that he had not a copy of taken.
the work at hand), is not to be found in the first case of de
Moivre, or yet in any other case; neither can it be inferred
from any thing which he has said on the subject throughout
the whole of his work. Indeed had Opsimath proceeded
but a few pages farther than the first case, he would have
seen, that it was impossible for de Moivre to have considered
this as an elementary doctrine of chance, for at Art. 11 he
says, ** Let a be the number of chances for the happening The actuai
** of an event, and 6 the number of chances for its failing, Goctrine of d=
<* then the probability of its happening once in any number of here
“ trials will be —— -$ ital a a

oto t Shay) ape
* number of terms be equal to the number of trials given 2”
the application of which would give 33231 for the probabi-
hty of throwing an ace once in six throws; whereas Opsi-
math infers, and infers justly, from the expression which he
attributes to de Moivre, that £ or certainty would be the
amount of the probability; and this single circumstance,
had Opsimath proceeded so far, would have convinced him,
that he must either have attributed that to de Moivre which
he had never asserted, or else, at least, that he himself
must have misunderstood him.

Since the clause abovementioned appears to have been
the foundation of Opsimath’s scruples, and since this clause

is :

€ inise

&e., till the

206 ON THE DOCTRINES OF CIIANCE.

is not to be found in de Moivre, or I may add is any other
author that I have seen on the Laws of Chance, perhaps to
say any thing farther on the subject may be deemed unne-

cessary.
Lest however thedoubts of Opsimath should not be fully
Farther state. Pemoved, let as proceed with him a little farther.—He goes
ment of on to say, or rather to quote, that “ any one undertaking to
nue *< east an ace in two throws of one die, has for the first proba-
“bility }, as proved: should the first fail, then the second
** remains, which is + likewise; but the chance of the first
failing is 2, as that of its succeeding is 1; therefore the se-
cond throw has only } of 2 for its chance of success, which
added to the chance of casting an ace the first throw, is ++4
“of 2—31; the first throw being 5°, the second only 3%;.”
*« This doctrine,” Opsimath adds, * I cannot grant”—* be-
cause” gays he, “ nothing can prevent him of the second
throw, except his succeeding in the first.” Very true, but
eee ae his succeeding in the first may and certainly will prevent
these. him of the second throw. Opsimath should recollect, that
the probability of the event’s happening is calculated before
either throw is made; and that, till the first throw is made,
it is uncertain whether the second will be required ; and
consequently, that, though the second throw has “ the full
** force and virtue of 2 chance” after the first ts over, yet, be-
fore that event, its value can only be } multiplied by the
probability that the first throw will fail, for on the failure of
the first depends the necessity of the second—that is, since
the probability of the existence of the second throw, if [ may

so term it, is, before the first takes place, only 2; and, should

s¢

ca

©

”

6

at exist, the probability of its producing an ace is only 4;
therefore, before either throw is made, the value of the pro-
bability of the second is only § of 3, that is ,, which, ad-
ded io 1, the probability for the first throw, gives 44 for the
probability on the two,
Atcncred by Should this consideration of the dependence of the second
deducting the event upon the first fail to remove the scruples of Opsimath,
oh lie Ps yet, 1 thiak there will be no difficulty in convincing him
upon the principles, which he has himself admitted, that 34
express the true probability of casting an ace once im two
threws. Since the probability of an event’s happening, to-
; gether

ON THE DOCTRINES G¥ CHANCE. OO7Z

gether with that of its failing, makes certainty, which is re-
presented by unity, or 1, therefore the probability, that there
will be an ace in one or two throws, together with the proba-
bility that there will not be one, is equal tounity. Now the
probability, that there will not be an ace the first throw is %,
and since, whether there be one or not, the second throw will
be equally necessary for determining the probability that there
will not be one in etther throw, therefore this second throw
exists with ‘‘ the full force and virtue of the first, from which
no circumstance can deduct,” viz. the probability in the se-
cond throw will be 2, therefore the probability that there will
not be an ace in either the first or second throw will be 2x #
=$,, and, deducting this from unity, there will remain 34 for

the probability that there w7l/ be an ace in either the first or

second throw, the same as before.

Perhaps there is no branch of the mathematics, which is Lawsofchanoe

founded upon fewer first principles than the Laws of Chance; cop he inn

: ‘ Bt hi very tew prin-
and yet probably there is no subject, the first principles of cipies, yet very
which are so likely to be misapplied, or misunderstood. Qne liable to be
of the principal causes of the errours in our reasoning on this we.
subject, it may safely be affirmed, is the not duly discriminat- chiefly from not
ing between events which are dependent and those which are diseriminating
independent; and this seems to have been the source, whence pendent and
the scruples of Opsimath have originated; scruples, which, it eee muir
may be asserted, have been entertained by almost every one on
his first entrance on this subject. Perhaps, however, what
has been said above may tend to remove these doubts, if not,
we will conclude by advising Opsimath to acquire correct
ideas of the first principles of the Laws of Chance; and if
in his inquiries he be guided by right reasoning, we will assure
him, that there is no subject in which he will find the conclu-
sions more just, natural, or beautiful.

As it often happens, that theory is best understood by prae= Curious ques-
tice, and precept best illustrated by example, I have enclosed LS
the following question, taken from the Mathematical Reposi- trines of
tory, which, as it is rather of a curious nature, you may per- chance.
haps deem worthy of insertion; and as the solution, which I
have given to it, is founded upor the first and most obvious_
principles of the Laws of Chance, it may probably be useful

net

Probability of
the truth ofa
fact related by
two persons,

Cor. 1.

Cor, Zi.

ON THE DOCTRINES OF CHANCE.

not only to Opsimath, but to many other of your correspon-
dents.
Question.

A, with a truths, tells 5 falsehoods, and B with c truths, d
falsehoods, what is the probability of the truth of a circum-
stance in which they both agree?

Solution.

As they are supposed to agree in their relation, they must
either dofh speak truth ur both falsehood. Since then the pro-
bability of an event’s happening is always expressed by the
quotient of the number of times in which it may both happen
and fail, it is evident, that in the present case, the probability
of a circumstance being true, in which both of them agree,
will be expressed by the quotient of the number of times in
which they may agree in telling truth divided by the number
of times in which they may agree in telling both truth and
falsehood. Now the number of times in which they may
agree in telling truth will be the number of combinations of
ain c, viz. a c (for each of the truths a may be told with each
of the truths c); and for the same reason the number of
times in which both of them may agree in telling falsehood,
will be 6d; the true expression therefore for the probability

ac
required will be brew

ac
actbd
, now the probability of A’s telling truth is expressed by

Cor. 1. Let a, b, c, and d be all equal, then will

z
mr ayt which will also = 2; hence the probability of the
trath of acircumstance in the relation of which two persons
agree who are each in the habit of relating truths as often’ as
falsehood, will be the same as if related by either of them se-
parately.

Cor. 2. If abe greater than 6 and c greater than d, then

ac a oh

will Geb be greater than either Tb ae for

a aes ac

a+b an Gthbe end es acta

GeLaane™ since @ 1s greater

than

ON THE DOCTRINES OF CHANCE. ou

than 4, and c greater than d, the denominators a c+-b c and
ac+ad to the common numerator ac will be each of them
greater than a ans d and consequently the value of the frac-

tions less than —{7 ? viz. the probability ofa circumstance

ee
being true in ‘ta relation of which two persons agree, who are
each in the habit of relating more truth than falsehoods, will
be greater than when related by either of them separately.
ac
Cor. 3. Tf a be less Hae and ¢ less than d, then ——— aekbd Co %
os or nee viz. the probability
of the truth of a circumstance in the relation of which two
persons agree, who are each in the habit of relating fewer

truths than falsehoods, will be less than when related by either
of them separately.

will be less ‘baa tier

Cor. 4. Ifa be either greater or less than 6, and c=d, Cor. 4.
; ac ac a
then will ——— geabd= @ckbc mt a kb: viz. the probability
of the ai of a circumstance in the relation of which two
persons agree, the one of whom is in the habit of relating an
equal number of truths and falsehoods, and the other any
number of truths with any other number of falsehoods, will
be the same as if related by that other only.

ac ac

Cor. 5. If d = 0, then yekbad = ae ee coeeiaty, Cor. 5.
viz. the probability of the truth of a Circumstance in the
relation of which two persons agree, the one of whom uni-
formly relates truth, and the other any number of truths with
any number of falsehoods, will always amount to certainty:
as is evident from reflection also, for, in this case, to agree
they must both speak truth.

Cor. 6. Hence also it appears, that the corroborating tes- qo, ¢,
timony of a second person or witness 1s not always an adidi-
tional evidence in favour of the truth of a circumstance re«
lated by the first, for if d be greater than c, b d will be greater
ac

. a
acca zi (or its equal aise
VoL. XXI.—Nov, 1808. P will

than 6 c, and consequently

210

Cor. 7.

Not convinced
by a correspon-
elent’s argu-
ments 5

and why.

ON THE DOCTRINES OF CIIANCE.

ac
will be greater than ——-——; * viz.

Die be the probability of the

*
truth of a circumstance is greater if related by one person only,
thanif related by two, when the second is in the habit o1 relat-
ing a greater number of falsehoods than truths.

Cor. 7. Lastly, if the relations be supposed to be untold, or,
in other words, if 1f be supposed that A and B are each aboué

to relate d circumstance, the probability that they will both »

ac ac
speak truth will be expressed ==——

a+b x &- ‘ge yf = “ac +ad-+ be bd?

a
for the ee of A’s speaking truth would be pang. of
Le
B’s and therefore of both Se
Sar ateb x ctd

lt.

Farther Remarks on the Doctrines of Chance, By Opstmatii-
To Mr. NICHOLSON.

Sir, October 7th, 1808.-

I Beg to thank your correspondent Mr. B. H. for his re-
marks on my letter respecting the Doctrines of Chance,

‘obligingly inserted in your Philosophical Journal for Sep-

tember, although not productive of conviction on my.judg-
ment :—they strictly conform with the systems of de Moivre
and Thomas Simpson, whose publications are the only works
on this subject, which [have seen. Butas I fear not to have

made the path of reasoning, which leads to my deduction, as.

plain as it admits.J shall attempt to do so more effectually now,
provided my humble essay does not intrude on pages dedicated
to the promulgation of so much more valuable information.
The variation of result arises, as Mr. C’s remark observes,
from six successive throws of one die being assumed equal to
i simultaneous throw of 6 dice; which position, in my mind,
it completely subverts, though supported by the atithority of
the above celebrated names. Let us compare 2 throws of 1
halfpenny with 1 throw of 2, as to their chances of a hicad’s
béing

ON THE DOCTRINES OF CHANCE, 911

being thrown, which are less complex, and stand on precisely
the same base with the throwing of 2 dice.

Inthe former case I say, I have % of success as my. first Case of a half
probability; if successful, I dispense with the second throw,P°"%
which is however altogether optional on my part, being my privi-

lege by premises. If unsuccesstulin the first, I of course avail
myself of the second chance, which, when to be exercised, I
cannot estimate in any wise less valuable than its predecessor3
and thus [ have in all 2 one half chances of success equal to
each other, and together equal to assumed certainty on the
average of probability: at least such is my conclusion, for I
cannot lose without first haying had 2 one half chances of
winning.

In the latter case I say, I can only Be by throwing 2 tails
at once: the probability of throwing one ot the halfpence a
tail is evidently 3, and of doing so with the other, were this
iets. $ also; therefore the contingency of throwing both
tails, is $ of $ = %. Now the probabitity of fsiling Z, being
alndaed fei unity, or assumed aggregate of all chances,
leaves 3 for the probability of succeeding. Or otherwise, as
I can win by throwing 2 heads, for which | have } probability,
and also by throwing 1 head, for which [ have } probability,
the amount of probabilities to do one of them, is as before 2

Therefore I estimate 2 throws of one halfpenny, 4 better
than 1 throw of 2 halfpence in the chance of throwing a head.

But if it were required to throw 2 heads instead of 1 in the If required te
above cases, I estimate the chances of 2 successive throws Si ratewryps
one halfpenny, and of 1 simultaneous throw of two halfpence,
perfectly alike, viz. each 1; for in this instance, each of the
2 heads supposed to be thrown at once with the 2 halfpence
- has its value; in the former 1 head is without value at all.

And here stands the deceptive point of distinction, the com-
bination of 2 aces with dice, as pointed out by C.

But reasoning even with the disciples of de Moivre, I can If the value of
not but observe, if they diminish the value of the second throw abet ee
of 1 die, they ought proportionally to increase the value of other ought to
the first; for it strictly yields them a twofold advantage, viz. >° diminished,
i chance of success as admitted, and likewise 2 chance of ano-
ther probability on the failure of that,

P72 - And

812 ON THE DOCTRINES OF CHANCE.

And Mr. B. H. advancing the entire coincidence of probabi-
lity of the 2 dice with one throw, and of the 1 die with 2
throws, as he giyes No. 1 throw, 1, advantage over No. 2
throw, he can not in justice withhold from die A, the same 3y
advantage over die B, when thrown together; which is exartly
the fatal invalidity of its ace, in combination with the ace
of A.

I remain, Sir,

Your obliged, and most obedient Servant,

OPSIMATH.
SC sa
REMARK.

Too many tee NUMEROUS communications of considerable extent, and

Sopa be some of a controversial nature, having been received on the
Doctrines of Chance, it was impracticable for the editor to in-
sert them all, notwithstanding the merit of several, as they
would have occupied a great deal more room than is consist-
ent with the plan of his work. He has however admitted the
letter of Mr. Saint, as containing a curious problem in the
application of the doctrine of chances; and has thought it
right, that Opsimath should again be allowed to speak for him-
self,

The word cer- In answer to the latter gentleman, he would observe, that
pga Horii he appears to be misled: by not adhering to the strict meaning
of the word certainty, and confounding it. with what may pro-
perly be termed the right of expectation. In throwing adie,
there is no reason we can assign, why a deuce, a trois, or any.
other of the sides, should turn up preferably to anace. We
have therefore a right to expect, that an ace will. be turned
up onee in six times. Farther, if I do not throw an ace the
first time, when I have to throw asecond, I have neither more
nor less chance of bringing an ace, than E had the first time.
Thus, if a stake of thirty guineas were deposited, to which the
thrower of an ace would be entitled, I ought to give five gui-
neas for the throw, it being just one fifth of what I should win,
and there being one chance for my winning, and five for my
lusing. If Llost, and chose to throw again, I ought again to

give

ON THE DOCTRINES OF CHANCE.’ : 213

give five guineas for the throw, as my chance would be pre-
cisely the same; and so on for any single throw, however
often I might fail. Still, though previous to my having thrown
at all I should have a right to expect to throw an ace in six
throws, it is not a certainty, for I might very possibly throw Nosum ofcon-
some other number every time. In fact, no sum of contin- pea waned cer-
gencies, make them as great as we please, can ever amount to tainty.
acertainty, unless we take all the chances both for and
against a thing’s happening: And certainty is used with strict
precision in the doctrines of chance, as being the sum, not of
all the chances of saccess alone, or of failure alone, but of
all the chances both of success and failure. Thus if I had a
box capable of throwing ten thousand dice at once, and were
to throw them ten thousand times, however great the probabi-
Hity of bringing an ace out of the hundred millions of faces,
it would be by no means certain; for ten thousand dice admit
of ‘a great variety of combinations, in which no aee appears,
and one or other of these combinations might turn up each
of the ten thousand times. Now, the beauty of the doctrines Doctrines of
of chance consists in this very thing, that they appreciate, not chance esti-
merely what we have a right to expect, in any given instance, iene
but the chance there is of our failing of this expectation, sion.
We have a right to expect an ace in six throws of adie. If
we throw a greater number of times, we have a right to expect
one.sixth of the number will produce aces: and the greater
the number of times, the hearer the number of aces will be
: likely to approach to one sixth of the whole; since it is obvi-
- gus, that there will be the greater chance of more aces than
one turning up in some of the series of six successive throws.
to compensate for those series of six in which none have Oce-
curred. Now these probabilities the doctrines of chance, as
established by some of the ablest mathematicians, calculate
with much precision on solid principles: and it is in this way
we find, that, though we have a right to expect to throw one
ace in six throws of a die, yet the chance of so doing is iar
“worse than certainty.
I cannot conclude without observing, that thereis consi-
derable merit ina student’s refusing implicit reliance on any
name, however great; and suspending his judgment till his
under-

914, NEW ORGAN IN SEEDS.

understanding is convinced; but I trust what has been said
will prove sufficient, to remuve the doubts of Opsimath. C.

XIU.

Memoir on the Organ by which the fertilizing Fluid is capas

ble of being iniroduced into the Ovula of Vegetables, By

: P. Turrin. Read at the National Institute, December
the 4th, 1808*,

Discoveries ow- lx Natural History, as in all ofher sciences, we are somes

al cena times indebted to chance for discoveries, though they more

examination, frequently arise from the deductions of reasoning, and from
observation. It is to the last of these I owe the discovery
of the organ, which will be described in this paper. This
organ, hitherto noticed only in the seeds of the lezuminous
plants by those celebrated botanists Grew, Gleichen, and
Geertner, and in our own days by Mirbel, according to my
researches forms a necessary part of the structure both of
monocotyledonous and dicotyledonous seeds.

Coatsofaseed. Before we proceed let us examine what are the principal
organs, that the two coats of the ovula exhibit; or, as the
readiest way, let us examine the proper coats of @ seed are
rived at maturity.

Base of a seed It is admitted, that the base of the seed, whatever its

a, figure, is always determined by the point which adheres to

Bee the placenta. This point, which has received several names,

such as umbilicus, hilum, aud eye, comprises three distinct ‘

organs, each having a different function to fulfil, yet all hi-
therto confounded by botanists under one term.

The hilum, he first of these organs, to which the name of hnlam is
per fectly adapted, 1s that cicatricula, which 1s most com-
monly called the umbilicus of the seed. The lips of this
cicatricula, which are sometimes very large, as im the sapota
plum, soap-berry, chesnut, and some. legumes, inosculate
with the exterior vessels of the umbilical cord, which, divid»

* Journal de Physique, vol. LXIIT, p. 195,

‘

ing

NEW ORGAN IN SEEDS. 915

ing afterward throughout the whole extent of the outer
coat, constitute its vascular organization.

The second, which I term omphalodes*, is an aperture A ompha-
placed most commonly in the centre of. the hilum, but oe
sometimes toward one of its extremities, and sometimes it is
a longitudinal cleft extending from one end of it to the
other. This organ, wholly negleted by botanists, forms the
passage between two other vascular systems; the first of
which, that is the outermost, after having inosculated. with
the hips of the hilum of the internal membrane, forms its
organization in the same manner as that of the outer coat
already noticed. In fine, as we observe an omphalodes on
the outer integument, we perceive one onthe internal mem-
brane, through which the third vascular systern passes, con~
sisting of the umbilical vessels, by which the embryo was
aiiched to the parent plant pr evious to its fecundation,
and for some time aftert.

The third is the subject of the present inquiry.

All physiologists are aware, that the point by which the Direction of
_ evula adhere to the ovaries marks the direction in which the '° i Fag
radicle will push forth, and this is without exception. For

instance in some families of plants, as the dipsacee, capri-

fohaceze, and jasminez, the ovula are constantly attached

' to the summit of the cavity of the ovaries, and the radicle

is superior: in others, as the campanulacez and composite,

the pomt of adhesion is inferior, and the radicle is the same.

But the better to generalize our ideas, let us rather say, that

the direction of the embryo is always subordinate to that of the

* From the greek o4QaAos, the navel, and odos, a way.

+ Grew appears to be the first, who observed the umbilical vessels of {{mbilical ves-
the embryo. These umbilical vessels, the only ones that deserve the sels.
name, constitute the innermost vascular system, which, after having
passed the coats of the seed by means of the omphalodes, divides into
two branches, each of which inosculates with the lobes of the embryo,
near the point where they unite with the radicle and plumula It is to
be presumed, that these vessels quit the young plant pretty early ; for it
is extremely difficult, to find any traces of them in ripe seeds, except in
those of some of the coniferous plants, the tropeolum, and several of
the legumes, in which the two umbilica] cicatrieule are very evident.

seeds

216

Point of attach-
. ment of the
ovulum,

Fecundation,

Common opi-
nion respecting
it.

Not probable.

Another organ
sought after
and discovered.

This organ al-
ways as near as
possible to the

ey Es

Direction of
the radicle.

NEW ORGAN IN SEEDS.

seeds im the pericarp, and that the point by which these are
attached always determines the direction of the radicle*.

It is known too, that the point of attachment of an ovu-
lum is the umbilicus, with which an mfinite number of vese
sels, destined to form at first the vascular organization of all
parts of the seed, and then to convey nourishment to it
both before and after fecundation, inosculate in the form of
a cord of greater or less length: but how is this fecundation
effected? by what way can it reach and penetrate the ovula.
This is certainly an important question to be solved, and on
which, to this day, scarcely any thing has been said. The
opinion most generally received is, that the prolific vapour
descends from the papillc of the stigma into the placenta,
and transmits the fecundation to the embryo through the
umbilicus. But I would here appeal to reason, and ask
whether it be conceivable, that the same vessels, and the
same aperture on the ovula, can fulfil two such different
functions as those of conveying to the embryo nutrition and
fecundation, the sources of which are so opposite.

Such was the reasoning that induced me, to examine
carefully whether some other organ beside the nourishing
umbilicus did not exist in the ovulum. It was not long be-
fore I discovered what I at first suspected: for on the first
dissection I observed near the cicatricula of the hilum an-
other aperture, which I could not avoid immediately con-
sidering as the organ, by which the intromission of the fers
tilizing vessels must take place.

This organ, as I have satisfied myself by more than twelve
hundred dissections of seeds with one and two cotyledons,
is always placed as close as possible to the hilum at the
time of fecundation; and if it sometimes recede from it af-

* When I say, that the radicle is always directed toward the umbilicus,
J mean the umbilicus of the internal membrane. This membrane, to
which the direction of the embryo is always subordinate, may sometimes
be inverted in the outer integument, as in the lousewort and eyebright:
for as there are seeds inverted in the pericarp, for instance in the plum
and the hazel nut, so it happens, that the interior membrane is inverted
in the outer. This organization requires, that the umbilical cord, after
having passed through the exterior omphalodes, should creep between —
the two coats, to inosculate at the base of the interior membrane, which
in this case is opposite to that of the exterior.
terward

NEW ORGAN IN SEEDS. » 217

terward, it is solely owing to the growth and enlargement
of the seed. Its situation near the point of adhesion is such,
that the fertilizing vessels may enter it by the shortest way.
Thus in the labiati we find it constantly placed toward that
part of the hilum, which faces the centre, and is conse-
quently as near as possible to the style. In the liliaceous
and leguminous plants, and in general all those that pro-
duce capsules in which the seeds adhere laterally, it is su-
perior to the point of adhesion, as we may easily see in the
French bean, or any other pulse. I ought also to observe, ang opposite
that it constantly answers to the pomt of the radicle*, in the point of
every seed in which the internal membrane retains the same richie i230
direction as the outer integument. If on the other hand Two distinct
we consider, that the fertilizing vessels can have no other Sige Tes
communication with the embryo but by the papilla of the ing, the other
stigmata; and if to this be added, that the fecundation is o pemersiye
intended solely for the embryo, and influences it alone,
which it would be easy to prove by a number of facts; we
shali not be surprised, that there are two entrances to the
ovula, the first of which, termed by me the micropylet,
serves to give a passage to the fertilizing vessels, while the
second, being the umbilicus for conveying nourishment,
must be intended for the inosculation of the sapvessels of
the parent plant. The sole function of the latter must be
that of supplying aliment suited to the delicacy of the
young embryo, by furnishing it with juices already in some
sort digested and filtered by the extreme tenuity of these
vessels,
The existence of fertilizing vessels has long been proved, Fertilizing vese
They have engaged the attention of physiologists ever since sels
the establishment of the Linnean system; several have
traced them from the stigmata to the ovula; and they be-

* Every physiologist knows, that the radicle is the part of the em- The radiclz.
‘bryo, in which the vital principle appears strongest. This part, which is
always the first perceived after fecundation, is likewise that which first
lengthens and dilates in germination: accordingly it is toward this, that
“nature has thought proper to carry directly the, fertilizing fluid, placing
it opposite the micropyle, through which the vessels intended for this
function enter .

+ Micropyle, from pesxgos, small, and 7vA%, a gate.
heved,

218

a
The micropyle
mot easily seen
in ripe seeds.

Grew saw it,
but mistook its
office,

and in another
place ascribes a
similar office
to the coats.

Organized be-
tgs have two
lives,

. NEW ORGAN IN SEEDS.

> - F}

lieved, that these vessels, uniting with the umbilical cord,

transmitted the fecundation to the embryo through the um-

bilicus itselfi But as this cord is an assemblave of fertilizing

and nutritive vessels, and as there are two apertures at the

place where it reaches the ovula, is it not more reasonable

to suppose, that it 1s divided there; that the nutritive ves-

sels inosculate with the umbilicus properly so called; and

that the fertilizing vessels pass through the micrepyle, to

communicate immediately to the embryo the vital principle,

or rather that contact, so necessary to the first life of every

organic being *? |

The little perceptibility of the micropyle on seeds arrived

at maturity 1s perhaps one of the causes, why it bas been

overlooked by so many natural philosophers. T said at the

beginning, that 1t had been seen on several of the legumi-
nous seeds by Grew, Gleichen, Geertner, and Mirbel; but

none of these expert observers, except Grew, deemed it of
any importauce. Grew ascribed te it two functions, one of
which has been already refuted by a number of experiments
made on the subject. In the first place he imagined, that

this aperture might serve to facilitate the introduction of air
and moisture into the seeds at the moment of germination.

This notion, which might appear very ingenious and satis-

factory when Grew wrote, 13 inadmissible in the present
state of our knowledge. We now know from a thousand
experiments, that the stepping up of this aperture, and
even that of the emphalodes, with wax or varnish, does not
prevent the developement of the embryo. Grew himself, in

another part of his work, overturns the use he had at first
ascribed to this organ, when he says expressly: “ the bean —
* being enclosed in its skins, it is necessary, that the juices

« intended for its nourishment must pass through them by

‘* filtration, and impart to the embryo only the quantity re-

<< quisite. H the embryo were divested of these, it would

«© draw too much juice; and as it would be without its fi-

* Every organic being has two lives. The first receives its fertilizing
principle and nutrition by means of an umbilicus. The second com-
mences at the moment when the embryo or fetus, having attained its
appojnied degree of maturity, separates from the placenta, and takes ia
aliment at a single mouth orat thousands, rf

“© ters,

NEW ORGAN IN SEFDS. S19

ters, which commonly strain the moisture likea very fine
** cotton, it would perish, from being unabte to feed on teo
“* gross aliment,” It is easy to perceive by this passage,
that Grew contradicts himself, and that, admitting with
more reason the use of the coats, which he very ingeniously
compares to filters, he entirely rejects his firgt opinion of the
functions of the micropyle.

This learned anatonist, having observed the micropyle He like-vise
sup! osed it af-

3 ; : , forded a pas-
organ is constantly placed opposite the point of the radicle, sage to the ras

. 5 . 7 1;
had imagined, that it likewise served to afford this a passage “le.

oily m a smail number of leguminous seeds, in which: this

‘in the process of germination. But how is it to be con- This improba-
ezived, that a radicle twenty or thirty times as large as the ble ita its
aperture of the micropyle can issue threugh it? | Besides, iui
where is the person, that has ever had an opportunity of see-

ing a seed in the state of germination, who has not observed,

that the radicle never emerges from its captivity, till the

coats, being unable longer to contain the embryo, regularly

burst, and thus give a passage first to the radicle, and af-
terward to the entire young plant? Tf’ on the other hand we

add to this refutation, that, in a considerable number of and the flexion
seeds, the interior membrane deseribes a quarter of a circle oe
round itself in the outer integument, as in the commelina cases,

and tradescantia, or a semicircle, asin the eyebright, louse-
wort, and cow-wheat, we shall plainly perceive, that the
micropyle of the interior membrane, to which the point of
the radicle answers, must be a quarter of a circle distant from
the outer micropyle in the former, and half a circle in the
Jatter ; and that from this construction it would be i im possi-
ble for the radicle ever to issue’ by this aperture, since for
this purpose it must wind between the two coats, to come
out at last through the external micropyle, which in seeds
of this kind is always opposite to the micropyle of the inner
membrane, and to the radicle, which is inseparable from
the latter.

If I have been so fortunate as to make known the true A new Jaw in
way of fecundation in the ovula of vegetables, this is not ae of
the only advantage, that vegetable physiology will derive sae
from my labours; for the dissections I have been obliged to
make, to generalize the presence of the mici ‘opyle in all

seeds,

:

220 NEW ORGAN IN SEEDS.

seeds, have enabled me to add a law to carpology, which
I conceive to be of such a nature as to admit no exe
ception. |

Fruits consist Thoroughly to understand this law, it is necessary to

ef four distinct } : weet

parts. recollect, that all fruits are composed of four very distinct
parts, each of whish has its own peculiar system of vessels.:
The first is the pericarp; the second, the outer integument
of the seed; the third, the internal membrane; and the
fourth, theembryo. But I conceive, that, to facilitate the
study of carpology, it will be sufficient to divide fruits into
_ The last three two parts only; the first of these being that envelope of
pt cl eines various forms, and of various substance, which botanists
term the pericarp; and the second, the seed, which is al-
ways united by an umbilical cord to a central receptacle,
detached or adherent, or to the inside of the pericarp.
These two parts, which have been too frequently cons
founded together, may be discriminated in future by inva-
Characters by riable characters easily distinguished. A seed must always
cannot) be attached to an umbilical cord, longer or shorter, and
guished froma always provided with two cicatriculz at its base, one of
patee which is the nutrimental umbilicus, the other the micro=
pyle: but it cannot in any case have a style, since the
styles themselves are nothing more than an elongation of the

Theacom, placenta, or receptacle. Thus the acorn separated from its

chesnu’,and cup, the chesnut divested of its bristly coat, the nut of the

mei ae nelumbium taken out of its receptacle, cannot be seeds

seeds, properly so called, since their coats are terminated - by
styles. It is undoubtedly fur want of knowing this law,
that Geertner, after having described the acorn and chesnut
as pericarps, describes the nut of the nelumbium as a sim-
ple seed *.

Ricapitulation. On considering what has been said in this paper, it ape
pears, that the micropyle is constantly placed near the am-
bilicus at the time of fecundation ; and that, if it afterward
recede from it, this is owing to the dilatation of the seed:

The micropyle * The mycropyle may serve likewise to distinguish the seed from the

distinguistes a ail. The latter, as Mr. Richard has very justly observed, being only

seed from an an expansion of the umbilical cord, which covers the seed wholly or in

c part, cannot have the micropyle, the orifice of which is always in the
proper cuat of the seed.

that

NEW ORGAN IN SEEDS. 99 ji

that in all these seeds, in which the internal membrane
preserves the same direction as the outer integument, its
situation is always opposite to the point of the radicle:
that the umbilical cord, or rather that assemblage of the
nutritive vessels belonging to the coats of the seed and the
embryo, cannot admit iato it the fertilizing vessels: that
the extent of these in the plant is and must be only from
the papillee of the stigmata to the embryo: that, after hav-
ing descended into the placenta, they join the nutritive
vessels, and then proceed withthem, forming a single cord,
to the pomt where the ovulum is attached: lastly, that
at this point there are two apertures, and it appears pro-
bable, that the nutritive vessels pass through the umbilicus,
and the fertilizing vessels through the micropyle.
= ee

Note. When I wrote the above paper, I did not know, Gaur, oy ole
that the organ of which I was speaking had already been served this of
observed by Geoffroy, though it has not been mentioned by ®*™
the authors who succeeded him.

Geoffroy’s paper is inserted among those of the academy His account
of sciences for the year 1711, and is entitled, Observations ‘-
on the Structure and Use of the principal Parts of Flowers.

The author recognises the existence of the micropyle in all
seeds, and ascribes to it the same functions as I have
done, but with some little difference. I conceive I cannot
do better, than describe the passage, in which this gentle-
man, after having attempted to show, that every grain of
the pollen might be a germe, destined to be introduced
into the ovulum, and. there become a young plant, says,
p- 230. “ Pursuing this conjecture, it is not difficult to as-
“© eertain in what way the germe enters into the vesicles:
“ for, beside that the cavity of the pistil reaches from its
“‘ extremity to the embryoes of the seeds, these vesicles
“«« have likewise a small aperture near the place where they
“ are attached, which is at the extremity of the canal of
** the pistil; so that the small particle of dust may natu-
«© rally fall through this little aperture into the cavity of
“* this vesicle, which is the embryo of the seed. This ca-
¢ vity, or kind of cicaticula, is sufficiently evident in most

seeds; it may be seen very easily, without the assistance
sal 3

ON THE COMYOSLETION OF ALCOHOL.

© of a microscope in pease, beans, and French beans.”

Progress made
m vegetable
physiology
since his time.

Proportions of
the elements
ef vegetables
little known.

Fermentation.

Here Geoffroy falls into the same mistake with Grew$
when he adds; ‘* The root of the little germe is quite close
“* to this aperture, and through this same aperture it Issues
* oat, when the seed comes to cerminate.”’

When we reflect on what city says, itis easy to per=
ceive the progress, that has been made teward the know-
ledge of plants within a century. We can no longer sup-
pose with this naturalist, that the Bee of the pollen are
germes, as he says; and still less can we think, that these
particles can ever be introduced nie the ovula by the micro-
pyle. The present state of our knowledge instructs us;
that the particlés of dust contained in the anthers are so
many little bladders fitled with a finid, the only substance
to which we allow a fertilizing qtiality, and the only one ca-
p2die of being conveyed into the embryoes.

We also know, that the canal feund in the centre of the
styles of all the monostyle ovaries, and destitute ofa central
adherent receptacle, cannot in any way promote the process
of fecundation, and is nothing but the cavity of the ovary,
which is prolesged through the style as far as the stigma.

eee = SF

XIV.

Essay on the Composition of Alcohol and of Sulphurie Ether,

By Turovere peSavussure. Readto the Physical and
Mathemotical Class of the Institute April the Oth. 1807*.

Secr. I. Jntroduction.

‘Tue proper methods of arriving at a knowledge of the
proportions of the ultimate clements of vegetables are yet
so uncertain, and so badly determined, that every inquiry
into the subject must furnish useful observations, whatever
be the material to which it is apphed. The theory of fer-
mentation can be known only by an analysis of its products,
and among these alcohol will always hold an important
place. ;

* Journal de Phissique vol. LXIV, p. 316.
The

s

ON THE COMPOSITION OF ALCOHOL.

"The change experienced by fas fluid during its transfor-
-waation into ether has occupied the attention of the ablest
chemists. Some have ascribed to ether moze oxigen aud
Jess carbon than to alcohol*: others have énthribed the op-
posite ‘vpiniont. These contradictory conclusiens are
founded on indirect considerations, and the question must
remain undecided, if it be not subjected to a more profound
examination. This may, be accomplished by two different
processes. One consists in analysing the residuum left by
the alcohol and sulphuric acid after the separation of the
ether: but this residuum, which consists of several different
and very compound substances, requires for its examination
an immense labour abounding with difficulties. The other
process confines itself to the analysis of alcohol and of ether,

and to deducing from théir difference the changes they have 4,

undergone duriug their transformation. I ive chesen the
latter mode: as to the advantage of wii more easy it adds
that of giving us a more absolute knowledge of the compo-
sition of these two substances.

The operation by which I have analysed them consists
principally in changing them, by an addition of oxigen, into
water, and carbonic acid gas, and estimating from ite known
composition of these the quantities of carbon, oxigen, and
hidrogen, contained in alcohol and in ether.

The proportions of the elements of water and carbonic
acid gas have not been ascertained with such precision, as
to leave no uncertainty respecting them; and I will not
venture to affirm, that those I have adopted, and which I
am about to mention, are preferable to any other. It will
be easy in this respect to alter the last terms ef my analyses,
considering, Ist, the volume of the oxigen gas, which I
eaused to disappear by burning a given weight of alcohol
and ef ether; and, 2dly, the volume of carbonic acid gas
produced at the same time. These two terms alone are
the fundamental and important expression of my results.
In ail the subsequent experiments | admit

1, that 100 parts of water contain 88 parts of oxigen by

‘

* Annales de Chimie, vol. XXILM, p. 43.
$ Statéque chimique, par Berthollet, vol. i!, p, 552.
weight,

2953

Conversion of
alcohol into
ether.

Contradictory
Opmions re-
specting it.

Two ways of
coming at the
truth,

Analysis of the
tesiduum of
the ether too
difficult.

Easiest method
to analyse both
ether and alco-

Mode here

pursued.

Elements of
water and car-

" bonic acid net

completely as.
certained,

Pioportions of

2904 ON THE COMPOSITION OF ALCOHOL.

principles _ weight, and 12 parts of hidrogen, neglecting the frac+
adopted in this tions.
paper. 2, that two parts by measure of hidrogen gas saturate one

of oxigen gas, to form water.

3, that 1000 cubic inches of hidrogen gas, the barometer
being at 28 inches, and the thermometer at 10° Reaumur
[54°5° F.], at the point of extreme dryness weigh 34°303
grs*.

4, that 100 cubic inches of oxigen gas, under the same.

circumstances, but at the term of extreme moisture, weigh
912°37 grs.

5, that 1000 cubic inches of carbonic acid gas, under the
same circumstances as the last, weigh 693°71 grs.

6, that carbonic acid gas contains its own bulk of oxigen
gas.

7, that 100 parts by weight We sqsbonsic aeid gas at the
point of extreme humidity, contain 26 parts of carbon, ne-
glecting fractionsf.

Alcohol at The alcohol I employed for this analysis was such as

i eae Lowitz and Richter designate by the name of perfect alco-

of lime. hol, and which they heve instructed us how to prepare. Its:
specific gravity is 0°792 at the temperature of 16° R. [68°:

F.]. I obtained it by distilling common spirit of wine from

half its weight of muriate of lime, dried at a nearly red.

heat, and drawing off only half the liquor. The product

* The French weights and measures are here retained, as they will be
generally throughout this paper. Tr.

100 parts car- + Since oxigen gas does not sensibly alter its volume when converted
bonicacid con- into carbonic acid gas, the difference of weight between the two gasses
tain 26.14 car- in equal bulks must give the quantity of carbon contained in carbonic

bon. acid.
According to my experiments, 100 cubic inches of carbonic acid gas
weigh eoereecee eee rarer sere o rs ss Osteen pers eeoeeeHes 69°371 gts.

100 cubic inches of oxigen gas CorcerseeceseH#eseoes 51°237
Difference.....0..0+0+ 18°154
Consequently 69°371 grains of carbonic acid gas contain 18'134 grains
of carbon; and by the rule of proportion 69°371 : 18°194:: 100:
26°14; so that 100 parts by weight of carbonic acid gas contain 26°14 of

sii
In this paper I have retained the old Paris measures, to render my re-

sults more easily compared with those of others.
Was

\

if

ON THE COMPOSITION OF ALCOHOL. 995

was still a little aqueous, and was farther rectified by dis-' oi
tilling from an equal weight of muriate of lime, and again
drawing off only half.

As we cannot expect to attain the truth in a business of Three process
so much difficulty as that I had undertaken, but by coming ses employed
at the same result in different ways, I employed three dif- eta
ferent processes for decomposing the alcohol. ee.

In the first I burned the alchohol by means of a lamp Fimt.
under a receiver filled with a mixture of oxigen gas and
common air, as Lavoisier did*, and I examined the products
of this combustion. The results obtained by this analysis
were the least accurate.

In the second I effected the decomposition of the alcohol Second.
by the instantaneous detonation of the elastic or gaseous va-
pour of this liquor with oxigen gas in a Volta’s eudiometer.

The third analysis was nade by decomposing the alcohol Third,
ya a redhot tube of porcelain,

Secr. II. Analysis of alcohol by slow combustion in a@ close
vessel.

The lamp I employed for burning the alcohol was a gras ajoohol burn:
duated glass tube closed at its lower extremity. It was 6 ed slowly in a
jaches high, and 3 lines in diameter internally. The wick Ser oe
was a slender cylinder of amianthus, passing through a me-
tal cap, which kept it in the axis of the tube. T had as-
certained by previous observation the weight of alcohol cor-
responding with each division of the tube, so that I could
tell by simple inspection of the column of fiuid in the
lamp, without taking it out’ of the receiver to weigh it, the
weight of alcohol consumed at the instant of its extinction.

I preferred this method to that of Lavoisier, who weighed ‘This method
his lamp before and after the experiment. In this way the eee
lamp could not be taken out of the receiver to weigh it, and Pad
to analyse the air in the receiver, till the latter was cold;
for it was of essential consequence to note the diminution
of the volume of air by the combustion. This cooling re-
quires near an hour; and during this period the high tem-
perature prevailing under the recetver volatilizes a consider-

* Journal de Phisique, vol. XXXI, p, 55. j ;
Vou. XX1L.—Nov. 1808. Q able

226

Process de-
scribed.

»

Gasses from
the combuse
tion of 35°5 grs.
of alcohol.

The carbonic
acid gas tn too
small quanti-
ties to be ab-
sorbed.

Water prefer-
able to mer-
cury because it
absorbs the lit-
tle alcohol eva-
porated.

ON THE COMPOSITION OF ALCOHOL.

able quantity of alcohol, which in Lavoisier’s process was
confounded with the liquid that had disappeared from com-
bustion.

My lamp, on the wick of which was a particle of phos-
phorus, was placed with a thermometer under a receiver
standing in water*, and half filled with common air. To
this I added oxigen gas, and the mixture occupied the space
of 651 cubic inches, the barometer standing at 27 inches,
and Reaumur’s thermometer at 17° [703° F]. Before the
combustion, according to analysis by Volta’s eudiometer, it
contained 228°25 inches of oxigen gas, and 422°75 of nitro-
gen.

The lamp, kindled by a burning glass, consumed 352 grs.
of alcohol. An hour after it was extinguished, the thermo-
meter under the receiver having fallen to 17° [702°], the air
contained in it was reduced to 599 cubic inches; and being
analysed by limewater and Volta’s eudiometer it was found
to consist of

Carbonic acid gas++++++++++ 77°87
Oxigen gasessseeseserceers 98°42
Nitrogen gas ++++++e+seeee+A99'7)

599.

I must remark, that the quantity of carbonic acid gas,
which formed only 0°13 of the residuum, was too small to
be perceptibly absorbed by the water under the receiver at
the high temperature .at which the process was conducted,
and in the short space of time between the combustion and
the examination by the eudiometer. I satisfied myself of
the truth of this by direct experiment. Besides I found an
advantage in substituting water for mercury under the re-
ceiver, as a small quantity of alcohol is always volatilised
without being burned, even while the combustion is going
on. If the receiver be lifted up immediately after the com-
bustion, and while full of vapour, we find this diffuses an
aleoholic smell. This vapour, which does not burn because
it is in great part aqueous, soon condenses in the water.of
the trough; but if it stood over mercury, it would increase

® In Lavoisier’s experiment the receiver stood over mercury.

the

ON THE COMPOSITION OF ALCOHOL. QO°7

the bulk of the air in the receiver in proportion to the alco-
hol it contained, even after cooling.

When the ingenious reasoning of Lavoisier is applied to Calculation for
the results of this experiment, we see, that 352 grs. of alco- the hidrogen,
hol employed for their combustion 129°83 cubic inches of
oxigen gas, and formed 77°37 cubic inches of carbonic acid
gas. The liquid residue of the combustion of the alcohol
was nearly pere water. Thus the oxigen gas I consumed,
deducting the 77°87 cubic inches, that entered into the com-
position of the carbonic acid, was condensed by. the hidro-
gen of the alcohol in the proportion that forms water, Con-
sequently 12)°83—77°87=51°96 cubic inches of oxigen gas
must have condensed 103°92 of hidrogen gas, or double their
volume.

If the weight of the carbon contained in the carbonic Qajculation for

acid gas produced during the combustion be added to the the oxigen.
weight of the volume of hidrogen gas just mentioned, we.
shall find, that the sum of these two elements amounts to
little more than half the weight of the alcohol consumed.
The weight deficient, or the other products of the analysis,
cannot exist in the residual gas, the weight and composition
of which are exactly known: it must therefore be in the
liquid residue, which I have said is nearly pure water, but
which I could not weigh, because it was dispersed in the ap-
paratus. That part of the hidrogen of the alcohol, which
. did not combine with the oxigen added, combined therefore
with the oxigen contained in the liquor itself, to form a
quantity of water, which may be estimated by the deficiency
in weight, On making the calculation accurately, and re-
ducing the analysis to 100 parts of alcohol, we shall find.
them to contain .

Carbon «-esessceeseees> 36°8900

Hidrogen s-esssseeeseee 9365

Oxigen and hidrogen in the
proportions that form water 53.745

100.

228

Proportion of
the elements.

A little azote
likewise.

Three experi-
ments nearly
agreed,

These compar-
ed with Lavoi-
sier’s.

His alcohol
weaker.

Still the differ-
ence great.

ON THE COMPOSITION OF ALCOHOL.
or, by substituting the elements of the water,

Carbon ceoeeeeoeesooecese 36-890
Hidrogen cee ecccerccces 15°814
Oxigen eeceeeveecvoerereene 47°296

100. .

We shall find, that a small quantity of nitrogen must be
incladed in the products of this analysis, for I found am-
monia in the water formed by the combustion of alcohol.
(See Sect. IV.)

I repeated this experiment three times with nearly thea bes
results; whence I imagine I made no mistakes, but such
as arise from the process itself, which is less accurate thant
those I shall hereafter describe. I ought however, to com-
pare this analysis with that of Lavoisier by the same pele
except in a few minutiz of detail.

To reduce our results to. expressions, that may be com-
pared with each other, and freed from the different estima-
tions we have followed with respect to the composition of
water and carbonic acid gas; I must say, that, in the experi-
ment of Lavoisier, the barometer being at 28 inches, and

the thermometer at 10° [54°5° F], 10 grains of alcohol con-

sumed 23°56 cubic inches of oxigen gas, and formed 10°194°
cubic inches of carbonic acid gas; while according to mine,
10 grs. of alcohol consumed 34°111 cubic inches of oxigen
gas, and formed 20-455 cubic inches uf carbonic acid gas,

at a similar pressure and temperature.

Lavoisier has not given the specifie gravity of the alcohol
he employed, I suppose he must have taken the alcohol
considered in his time as the purest, and such as Brisson in-
dicates in his tables, namely at a specific gravity of 0°829.
This denotes 4 mixture of 85°63 parts of perfect alcohol,
and 14°37 of water, according’ to the experiments of Rich-
ter, the accuracy of. which I have verified. But I find, that,
on deducting this proportion of water from Lavoisier’s alco-
hol, and in other respects adopting the results of his experi-
ment, 10 grs. of perfect alcohol would have consumed 27°518
cubic inches of oxigen gas, and formed 11°904 eubic inches
of carbonic acid gas. This correction therefore still Jeaves
a great difference between our observations.

I ought

ON THE COMPOSITION OF ALCOHOL. 299

I ought to remove one objection, that will no doubt be The alcohol
made against the kind of alcohol q analysed, it having been th ge
twice rectified from muriate of lime. Some chemists have muriate of
asserted, that spirit of wine rectified from this salt acquires lime.
properties, by which it approximates to an ether. For this
purpose I examined whether spirit of wine rectified by sim-
ple distillation, and without addition, would furnish by com-
bustion results similar to those of my former analysis, with
the exception of a quantity of water corresponding to that
indicated by the difference of specific gravities.

I rectified common spirit of wine by three successive dis- The experi-
tillations, without adding muriate of lime, and taking only —e
the first product of each distillation. Thus I reduced it to -3248 mien
the specific gravity of 0°8248, at 15° of R. [66° F.}.. The lone.
process was conducted as in the former experiment. The
gas in which the lamp was placed, the barometer at 27
_ anches, and the thermometer at 15°5° [67° F.], occupied the

- space of 638 cubic inches, 204 of which were oxigen gas,

and 434 nitrogen. By the combustion of 33 grains of spi-
yit of wine this was reduced to 598 cubic inches, consist-

ing of |
Carbonic acid gags---+++++++ 62°79
Oxigen gas scccereeeseess OO
Nitrogen ZASsescecseceres -436°09

——————

a
e

598.

From these results we find, that 100 parts of spirit of
wine, of the specific gravity of 0°$248, contain

Carbon @eoereseeevoeseaseoersece 32°24 Proportions.
Hidrogen e@eeoeeteoeveeaenere 8°23 :
Oxigen and hidrogen, in the

proportions that form water 59°53

100,

Richter’s table indicates, that 100 parts of spirit of wine This, allowing
of the density of 0°825 contain 12°8 parts of water. If from a a in
these. results therefore we would deduce the composition of a wash ies
perfect alcohol, we must substitute §9°53—12°8==46°73 for former experi-
59.53 in the preceding analysis, This will reduce the parts ™*":

repre-

230 ON THE COMPOSITION OF ALCOHOL.

representing pure alcohol to 87:2; and, making the calcu-
lation for 100 parts, they will contain

Carbon «sess eeceesseeees 36°97
Hidrogen .+.++--eeeeeeees 15°87
Oxigen e@vceceererovneeeoeonese A716

; 100.

This proves, The conformity of these results, with those of my first
eines analysis, evidently proves, that spirit of wine rectified with-
notaffected the out addition is identical, as to its essential principles, with
alcohol. alcohol that has been rectified only twice from muriate of
lime. Besides, the latter has none of the characteristics of
ether; but retains the properties of alcohol, such as having
a weak smell peculiar to spirit of wine, and not in the least
ethereal. Perfect alcohol combines with water in all pros '
portions, and its combinations with this liquid undergo
changes of density nearly corresponding with those, which
common spirit of wine undergoes*. It has a very small de-
gree of expansibility, not at all approaching to that of ether
the lowest rectified. Perfect alcohol formsa little soot dur-
ing its combustion, but only when it is made to burn with a
thick and stifled flame. Spirit of wine obtained by simple
distillation hkewise furnishes some under the same circum-
stances, buf not so much, because it is less concentrated.
Ether does or does not form soot according as the atmos-
pheric air has more or less access to it during combustion.
The character attempted to be derived from the presence of
soot therefore, for distinguishing these two fluids, is not
essential.
Possiblyit may I will not assert however, that alcohol distilled a greater
pony hire number of times from muriate of lime may not. contain a
or the rectifica- perceptible quantity of ether: for I have observed, after

tion too often
repeated. having twice distilled a pound of alcoliol from an equal

* 1 suppose however, that a sufficient quantity of water is first added
to the perfect alcohol to reduce it to the density of spirit of wine recti-
fied by simple distillation. Compare the changes ‘of the specific gravity.
of perfect alcohol by mixture with water in Die neueren Gegenstande der
Chemie by Richter, with the tables of Blagden and Gilpin in the Philoso-
phical Transactions for 1790 and 1794.

weight

ON THE NEW METALS. t 23]

weight of muriate of lime, that this salt, on being dissolved
_ in water, deposited a black substance on the filter, which
indicated the decomposition of a small quantity of alcohol ;
but this black matter was too little to be weighed, and from
this result and the preceding we may conclude, that the
quantity of alcohol decomposed is so small, as safely to be
neglected.
(To be continued in our next.)

XV.
Letter on the Subject of the new Metals. By Mr. A. CamBbs.

To Mr. NICHOLSON,
Sir, ‘

In your Journal for August is a paper by Mr. W. Cooke, new metal

of Wolverhampton, in which he states it as his opinion, that supposed to be
the new metal, obtained from potash by professor Davy, is a ari
not asimple body, but a compound of hidrogen, electrical

fluid, and potash.

If Mr. W. Cooke had taken the trouble to read the ela- This an unwar-
borate and refined experiments in Mr. Davy’s paper (which ted opt-
he might have done, as it has appeared in your Journal) he Fie
certainly would never have formed socrude and unwarranted
an opinion (which by the by is not original; but has been though not
stated before by Dr, Harrington of Carlisle, in the Gentle- new.
mans’ Magazine for July, except that the Doctor substitutes
the word phlogiston for hidrogen). Mr. W. Cooke would
have seen in Mr. Davy’s paper, that water is not essential to
the production of the inflammable basis of potash; and that,
by burning in air, it does not produce a solution of potash,
or moist potash, asit ought to do on his supposition, but
pure dry solid potash.

Having criticised Mr. W. Cooke’s criticism on Mr. Davy,

I shall beg the liberty of criticising another communication
on the same subject.
In a remark on a letter signed a “ Dilletante,” you say, Assertion, that

(for it seems to come from the editor of the Journal, though the alkalis
Ps have formerly

239 aby ON THE NEW METALS.

been supposed from its want of philosophical precision I suspect it has ano-
pal anesthe ther source) that the alkalis were long ago suspected to be
metallic oxides. This is nottrue. [ have read pretty ex-
tensively in chemistry, without meeting with such a suspi-
cion. That the alkaline earths and common earths were
dephlogisticated metals, has been a very old doctrine; but I
remember no such notion with respect to potash and soda.
I have looked into Dr. Beddoes’s Contributions; but I find
no idea there of the alkalis being metallic oxides; but I
have met with a much mere ingenious suspicion, namely,
that metals are compounds of hidrogen. and azote, which,
since the metallization of ammonia, does not seem so impro-

bable.

I am, Sir, with respect,
Your obedient humble Servant,

. A. COMBES.
Chelsea, Sept. 8, 1808.

EEL

REMARK.

WHEN a man ventures to affert, that a thing * is not

‘the author of true,”’ because he ‘ has not met with it,” he must haye con-
the preceding siderable confidence in the universality of his reading on the
io sa subject, the unremitting attention with which he peruses
authors, and the infallible retentiveness of bis memory.

Admitting however, that Mr. Combes never overlooks a
circumstance slightly or incidentally mentioned in a book

he reads, and that his memory is too tenacious, ever to let

slip what it had once received; it is surely very possible,

that he might have wanted opportunity or inclination to read

every work, that may have fallen into the hands of a reader

much his inferior in talents; and in someof these may have

been suggested: hints, that have hitched in a memory far less

tenacious than his. To speak with “* philosophical preci-

sion” indeed, he should merely have said, that he did not re-

collect ever to have met with such an opinion. I can only say,

as the opinion that, in a book so commonly read as Fourcroy’s Chemistry,
, #mentioned the opinion, that both potash and soda are of a metallic na-

by Fourcro
yeome’Ys sure is mentioned, if not directly, by implication. His

words

ON THE NEW METALS.

words are, in my translation of the last edition, val. II, p.
272, art. barytes*, “ the opinion relative to the pretended
metallic nature of barytes, as well as of the other salifiable,
and particularly earthy bases, will be nothing but a mere hy-
pothesis.”” Now es the term salifiable bases is used by
Fourcroy te signify the earths and alkalis; and as it cannot
by any means in this passage be confined to the earths, since
he immediately particularizes these, as if the opinion of their
metallic nature had been more prevalent, which is undoubt-
edly the fact; he clearly alludes to the opinion, that potash,
soda, and even ammania were of a metallic nature. The
very sljght way in which he records this opinion is owing to
his considering it highly i impr obable.

But the same opinion is given more decidedly and di-
rectly by a writer of our own country, Mr. Robert Kerr.

In his translation of Lavoisier’s Elements of Chemistry,
2d edition, Edinburgh, 1793, p. 217, the following passage
occurs 1 the text.. “ We are probably only acguainted as
*¢ yet with a part of the metallic substances existing in na-
** ture, as ail those which have a stronger affinity to oxigen
‘* than carbon possesses are incapable hitherto of being re-
** duced to the metallic state, and consequently being only
© presented to our observation under the form of oxides, are
*© confounded with earths, It is extremely probable, that
*¢ barytes, which we have just now arranged with earths,
*< is in this situation; for in many experiments it exhibits
‘© properties nearly approaching to those of metallic bodies.
*° It is even possible, that all the substances we call earths
«© may be only metallic oxides, irreducibleby any hither to
«© known process.”

And the translator adds, p- 219, an entirely new section,
sect. 6. On the metallic nature of the earths, in which he
relates the experiments of Ruprecht and Tondi, taken from
*¢ Baron Born’s description of the Cabinet of Mademoiselle
«* Raab;’’ who, as is well known, obtained metallic masses
by treating barytes, magnesia, and lime severally with car-
boniec matter in-a strong heat. This history need not be
here again revived, but it is material to add, that the lumi-
nous speculations of the translator, who expressly, p. 214,

* Original, vol. II. p. 196.
mentions

233

and is advanced
by the transla-
tor of Lavoi-
sier.

254

IGNITION BY COMPRESSED AIR.

mentions the alkalis as being probably metallic substances, -
and those of baron Born, appear to include in a general
way ail that the researches of Davy have realized by the
skilful management of an agent, the chemical power and
habitudes of which were discovered and extensively applied
in, this country within a few weeks after the knowledge of 1t
was transmitted to us. by Volta, one of the patriarchs of elec-
trical knowledge and invention. It is no derogation to the
merits of Davy, that he has explored the processes of na-
ture by simplicity of inyestigation, and clear deductions

grounded upon a knowledge of the anticedent analogies, to

Ignition by
compressed
air.

Theatr not
much con-
densed, for the
piston does not
recaal.

which he has put in no claim, and. upon which it is prabable
he may not at present set any high value,

XVI,

Remarks on Ignition by. compressed Air. In a Letter from
J. A. De Luc, Esq. .

To Mr. NICHOLSON.
SIR, Windsor, 15th Oct. 1808.

if HAVE found ia your No. 89, the following article:
‘* Question respecting the ignition of Tinder by compressed
«« dir.’ In this question, as well as in the reply, the igni-
tion is supposed an effect of the compressien of the air
itself; and this is the object on which | take the liberty of
addressing to you some remarks.

That this effect isnot produced by the compression of air,
is proved by some circumstances of the operation; for in
fact, the air does not arrive to a great density in the instru-
ment. If the original quantity of air remained sensibly in
the barrel; when the piston is let free, it would recoil as
much as it has been forced in, which is far from being the
case. A great part therefore of that air, is forced out in
the operation; and this even is necessary to the effect, for,
if the piston did not reach almost the bottem of the syringe,
the ignition of the tinder would not take place; and such a
motion would be impossible, did all the air, or its greatest
part, remain in the barrel.

It

IGNITION BY COMPRESSED AIR. 935

It is not therefore, the condensation of air, which pro- The cause is
duces the ignition; it is the condensation of the immediate yr ao
cause of heat; sometimes ealled matter of heat, but which,
in all the records of Natural Philosophy, is named fire,
igneous fluid, or their correspondents in all languages an-
cient and modern; and it has always been considered as an
expansible fluid, of great power of expansion, when arrived
toa great density.

This is the cause of our phenomenon; it is produced by as when iron is
the same kind of operation, which brings to a red-heat a slip eee

_of iron very rapidly hammered; and that cause is the cun-
densation of fire. That fluid may be compressed or rarefied
in the same manner as air, by mechanical means. Thus in Similar pheno-
the air pump, which furnishes both examples at once; at peel nea
the same time that the manometer rises or falls, by condens-
ing or rarefying the air in the receiver, the thermometer
rises or falls in it, by the condensation or rarefaction of the

- free fire mixed with the air; and both effects are produced

by lessening or enlarging the space in which fixed quantities

of the respective fluids are contained.

The only difference between the two cases proceeds from A difference in
that of the permeability of bodies to these fluids. The ves- ae siactiie
sels being impermeable to air, and made air-tizht, the con all bodies,
densation or rarefaction of air may be produced as slow/y
as convenient, without changing the effects : whereas no ves- whence rapi-
sel being fire-light, the operation requires a great rapidity, Tty necessary
Ie the same number of strokes of a hammer, which, by ra-
pidly succeeding each other, bring a slip of iron to incan-
descence, were struck at great intervals; or if the piston
which, being rapidly moved up to the bottom of the syringe
here in view, produces the ignition of the tinder, is moved
slowly ; these effects are not produeed: because the con-
densed fire has time to escape through the pores, in the
first case of the iron, and in the latter of the barrel.

- This, Sir, is what appears to me-the cause of the ignition
‘of tinder in that apparatus, which I beg you will consign
in ha very useful repository, if you think proper.
I am, Sir,
Your most obedient humble servant,
3 DE LUC.
XVII.

236 DISADVANTAGE OF JEWELLING CLOCKWORK.

XVII.

On the Disadvantage of Jewelled Holes in Clockwork. Ina
Letter from Mr. W. WALEER, to Mr. J. Barravp.

Dear Sir,

State of th if
Fewelled Nara AM sorry to have delayed so long the account you

efatransit wished of the state in which I twice found the jewelled

clock, holes of my transit clock, when I took it to pieces; as the
vibration had each time fallen off, from being on each side
the perpendicular 2° 10’ 10”, and were then no more than
130° 40°”,

After 15 In July 1805, under your direction, the clock was cleaned,

months goin
and 2 ee and was kept regularly going till Oct. 1806, when I went

rest, from home for two months. On my return on Dec. 6th, I
would not g0. wound it up, but could not make it go even when I added
ae a about two pounds weight more to the clock weight. I theres
jewelled sa el fore took it to pieces, and found the oil very fluid in all the
holes, except those which were jewelled, where it was. almost

black, and very glutinous. It required great force, and some

dexterity, to draw out the spindle that carries the secande

Bip going hand. I set the clock going again on the 7th of Dec., and
it immediately threw out its full vibration on each side=2°

10’ 10”; and continued to go with its usual excellence, till

eae ee towards the end of Oct. 1807, when it again fell off consi-
affected, derably ; and gained very much on its general rate. There-
from, the foule fore, on Nov. oad, 1807, I again took it to pieces; found all
era the jewelled holes extremely foul, black, and clogged; and
separated the jewels, which were strongly adhesive: yet the

oil on the pallets was very fluid, and in a good state in all

the brass holes. Before this cleaning the clock had gradually

thrown out less and less for two months preceding, and was.

at this time no more than 1° 30’ 40” on each side, but on

fresh oil being applied, it immediately became = 2° 10’ 10”

Excellence of on each side; and has gone with such excellence ever since,
oe that I cannot forbear transcribing the latter part of my Jour-
nal;

SCIENTIFIC NEWS. 237

nal; although in many other places, where the observations
have been carefully made, I might have selected you a longer
period ; but the variety of this month in temperature, the
thermometer in the clockcase having been at 16° and at 47°,
is perhaps as severe a test as could be brought forward.

Rate of my transit clock made by Mr. Barraud.

1807.
From Nov. 26 im
To Dec. 9 cove 4 1,3
10 ecos + 1,4
14 evco + 1,3

1808.
Jan, 3 ceee + 1,3
A sese 4 4,1
eee Saas
12 ees + 1,2

These were the only days on which I could get an ob-
servation.
I remain, dear Sir,

Your obliged Friend,
And humble Servant,
W. WALKER.

Manor House, Hayes, Middlesex,
20th JANUARY, 1808.

SCIENTIFIC NEWS.
Wernerian Natural History Society.

At the last meeting of the Wernerian Natural History
Society, (1st August) Dr, James Ogilby of Dublin read a
very interesting account of the Mineralogy of East Lothian, Mineralogy of
which appeared to have been drawn up from a series of ob- East Lothian.
servations made with great skill, and was illustrated by a

“4 sulte

238

Newest floets-
trap formation.

SCIENTIFIC NEWS.

suite of 350 specimens laid upon the table.—As the county
is in general deeply covered with soil, and profusely clothed
with vegetables, the determination of the different forma-
tions must have been a work of considerable labour; and
the skill, judginent, and perseverance of the observer, must
have been frequently. put to the trial. The doctor, after
describing the physiognomy or external aspect of the coun-
ty, gave. particular account of the different formations of
which it is composed. ‘They are as follows :—transition, in-
dependent coal, newest floetztrap, and alluvial. When de-
scribing the different transition rocks, he alludéd particu-
larly to the supposed granite of Fassnett, (described by
Professor Playfair in his Mlustrations of the Huttonian The-
ory *), which he proved to bea stratified bed of transition
greenstone. The description of the rocks of the newest
floetz-trap formation was particularly interesting, not only
on account of the beautiful transitions he pointed out, but
also as it proved the existence of a considerable tract of these
rocks in Scotland, where their occurrence had been dis-
puted. He enumerated and described the following mem-
bers of this formation :—traptuff, amygdaloid, clay-stone,
basalt, porphyry slate, and porpbyry slate inclining to green-
stone. He found the traptuff, which is a coarse mechanical
deposit, forming the Jowest member of the series, and rest=
ing immediately on the coal formation: on this tuff rests
amygdaloid containing fragments: above this amygdaloid is
common amygdaloid free of fragments; this, in its turn, is
covered with basalt : the basalt gradually passes into and is-
covered with porphyry slate: and the porphyry slate, in some
instances, appears to pass into greenstone, which forms the
uppermost portion of the formation :—so that we have thas
a beautiful series of transitions from the coarse mechanical,
to the fine chemical; that is, from traptuff to porphyry slate
incliuing to greenstone. The doctor also remarked, that
the amygdaloid contains crystals of feldspar which have an
earthy aspect; the basalt, crystals of feldspar possessing the
characters of common feldspar; and the porphyry slate,
glassy feldspar ;—facts which coincide with, and are iljus-
trative of the increasing fineness of the sgfution, from the

* Page 828,
oldest

SCIENTIFIC NEWS. ; 239

oldest to the newest members of the formation. In the
course of his paper, the doctor gave distinct and satisfactory
answers to the following queries, which had been proposed
by Professor Jameson: 1. Does the Bass Rock in the Frith
of Forth belong to the newest floetztrap formation? 2.
Does the sienitic greenstone of Fassnett in East Lothian
belong to the transition rocks, or to the newest floetztrap
formation? Are’ the geognostic relations of the porphyry
slate, or clinkstone porphyry, of East Lothian, the same as
in other countries? The docter announced his intention of
reading, at the next meeting of the Society, a description
of the different veins that occur in East Lothian, and of giv-
ing a short statement of the geognostical and economical in-
ferences to be deduced from the appearances which he has
investigated with so much care. It is indeed only by inves-
tigations like those of Dr. Ogilby, that we obtain any cer-
tainty respecting the mineral treasures of a country; and
such alone can afford us data for a legitimate theory of the
formation of the globe.

At the same meeting, a communication from Cel. Monta- New loneies oF

gue was read, describing a new species of fasciola, of a red fasciota occa~
colour, and about an inch long, which sometimes ludges in sbeee age
the trachea of chickens, and which the colonel found to be f
the occasion of the distemper called the gapes, so fatal to
these useful tenants of the poultry yard. The knowledge of
the true cause of this malady will, it is hoped, seen be fol-
lowed by the discovery of a specific cure: in the mean time,
a very siniple popular remedy is employed in Devonshire :
the meat of the chicks (barley or oat meal) is merely mixed
up with urine, in place of water, and this prescription is very
generally attended with the best effects. .

re

To CORRESPONDENTS.

Mr. Gough's answer to Mr. Barlow, aud the communica-
tion from Mr. Moore, in our next.

0's letters will be attended to,
- Weteor~

METEOROLOGICAL JOURNAL -
For OCTOBER 1808,

Kept by ROBERT BANCKS, Mathematical Instrnment Maker,
in the STRAND, Lonpon.

[THERMOMETER ssnone.| WEATHER,

2 ro | TER, a

mT Se $

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® High wind, hard rain at midnight

A :

JOURNAL

OF

NATURAL PHILOSOPHY, CHEMISTRY,

AND

THE ARTS.

DECEMBER, 1808.

ARTICLE I.

Answer to Mr. Bartow’s Remarks on the Essay on Poly-
gonal Numbers. By J. Goucn, Esq.

To Mr. NICHOLSON.
SIR,

My answer to Mr. Barlow’s criticism on the solution of Answer to Mr.
Fermat’s theorem was in the possession of that gentleman, Barlow’s critie
I believe, prior to the date of his letter inserted in your Pi
Journal, Vol. X XI, p. 118. “As Mr. Barlow does not think
proper to make use of my permission to publish the reply,
lam under the necessity of repeating in your present num-
ber arguments, which have been already stated in a private
correspondence.
Mr. B. opens his criticism by admitting the first three 1st objection
propositions, with their corollaries, to be correct; but he answered,
* does not see in what manner they are to be applied to the
general demonstration. ‘This objection may be answered
thus: If the remaining propositions be derived from these
three, or any one of them, the necessity of inserting them
all is established, because the third is derived from the se-
eond, and the use of the first appears in the course of the
Vor. XX1, No. 94.—Dec, 1808, R essay.

242

2d objection
answered,

GN POLYGONAL NUMBERS.

essay. ‘That the propositions following the third are derived
from those which precede them is. a faet, that is proved by
the references; consequently, if my paper contain a gene-
ral demonstration of the theorem proposed, the necessity of
the first three propositions is proved.

Mr. Barlow’s second objection charges me with false lo-
gic: and this gentleman states a sophism, which he consi-
ders to be similar to the argument used in cor. 2, prop. 4;
of the essay on polygonal numbers. He observes, ‘* that
** the author of this essay might, with as much propriety,
*‘ have said, that every natural number is either even or
‘‘ odd, and every aggregate of polygonals being also either
*< even or odd, therefore every natural number is the ag- —
‘* cregate of polygonals.” Mr. B. rests his refutation of the
argument used in cor. 2, prop. 4, on the supposed similarity
of it and the preceding sophism ; if then I can show these
two to be dissimilar, his second objection must be pro-
nounced futile. ‘To do this, I may observe, that numbers,
like most other things, are aggregates of qualities, not sin-
gle qualities, otherwise there could be no more numbers
than qualities; that is,a number, beside being odd or even,
is prime or composié, rational or irrational. This consider-
ation shows the nature of the intended fallacy contained in
the preceeding sophism ; for it maintains two aggregates of
qualities to be the same; because they have one of these
qualities in common, This I presume is an objection, to
which the demonstration in question is not liable: for
equality constitutes identity in numbers; that is, if any one
of two or more equal numbers possess any three of the qua-

-lities pointed out above, or any of the properties contained
‘in the definitions to the 7th Book of the Elements, all the

rest of them possess just the same, neither more nor less
(by axioin Ist of the same book). Now it is shown in the
first corollary to the 4th proposition, that every aggregate
of polygons of the denomination m is of the form p-— *

m— 2.5; where pis limited by 0 and m—3; and s is in-

pane ak hence it follows, that each ageregate of such po-

‘lygons is equal to an assignable value of p+ m—2. 5s.

~~

Moreover it appears from the second corollary to the same
proposition,

ON POLYGONAL NUMBERS.

proposition, that every natural number is of the form p +

m—2.s, limited as above: where s may be found, the
number being given with m and ni ; but this value of s subs
stituted in the form p+ m—2.s, gives an aggregate of
polygons of the denomination 2, ee is true in all cases ;
it is therefore a universal truth not admitting of one excep-
tion. The preceding facts appear to give indisputable ac-
curacy to the following syllogism: every natural number is

equal to an assignable value of the form p+ m—2.s3
and there is an aggregate of polygons of the denomination
m equal to the same value of the same form; therefore every
natural number is an aggregate of such polygons; because
things, which are equal to the same thing, are equal to one
another; Euclid, Axiom 1, Book 1; and equal numbers
have been shown to have the same qualities neither more
nor less. The supposed similarity betwixt my critic’s so«
phism and the preceding mode of argument appears to be
done away; for he proceeds on the supposition, that the
sameness of one quality constitutes identity in numbers;
but the first axiom of the 7th book of Euclid is the founda-
tion of my reasoning; namely, that a perfect agreement in
qualities produces the same thing, namely, identity of nums
bers. My opponent, in fact, does not rely altogether on
the similarity of his intended, and my accidental sophistry ;
for he produces a second sophism, and pronounces it to be
strictly analogous to nine, though it differs in every parti-
cular from his former parody of my supposed mistake,
Mr. B. observes, that “‘ every natural number is of the form

“p+ m—2%s; and, every square number being also ‘of

§* the form p+ m—2.5, therefore every natural number is
s*a square number.” It is true, that every square number

is of the form p + m—2.s; but then s is limited, being

- , a a
of the form s= qi cie yea, where g*= p or the
next greater square when p is not a square, and v is to be
taken so as to make s a whole number; but s is unlimited
in the case of natural numbers; therefore, by the rules of
logic, every square integer may be proved to be a natural
Re number

245

244

3d objection
amswered,

The proposi-
tion shown to
be universal,

ON POLYGONAL NUMBERS.

number, but not every natural number a-square integer.
On the contrary, s is unlimited in the aggregates of poly-
gons, as well as in natural numbers; therefore, my oppo-
nent’s second parody is equally unsuccessful with his first ;
because its imaginary resemblance to my syllogism has
been shown to be spurious. In the conclusion of this ob-
jection it is remarked, that the corollary under consideration
might be assumed as a postulate, i.e. as a self evident
problem; but far from treating it either as postulate or
axiom, he agrees with me in giving it the importance of a
theorem, and demonstrates it accordingly.

Mr. Barlow’s third objection is occasioned by an obvious
mistake on his part: I have said, that, if e = y + ¢ can be
resolved into m—f polyzons, e+ f may be resolved into
m polygons of the same denomination. My critic puts a
construction on this expression, which makes me suppose,
that y + ¢ can be resolved into m—f polygons of the de-
nomination m, in all cases. This is evidently a misconcep-
ton; for, had my opinion agreed with Mr. Barlow’s inter-
pretation of it, why have 1 attempted to demonstrate the |
theorem of Fermat; the truth of which I am supposed to
assert without demonstration in the preceding quotation
from my essay? The genuine meaning of the passage is
obviously this; if. e = y + ¢ can be resolved into m—f po-
lygons in any one case; e -+ f may be resolved into m such
polygons in the same case; which construction of the ex-
pression refutes this part of the criticism.

— All my opponent’s objections have now been controverted ;
but he farther remarks, that there is a diflerence betwixt
doing a thing, and proving that it may be done in all cases.
The justice of this observation obliges me to show, that
wiy essay also contains the principles of the latter demon-
stration. For this: purpose let the reader [ook at example 2,
prop. 7, which will assist him in- the following reasoning.
Ife = y+ m—1, it may be resolved into m polygons. (by
cor. prop. 6): again, if e = y-+ m, it moy be resolved into
two polygons, which are less than m; here f= m— 2, and
e+ fo=y+2m—2 is resolved into m polygons, (cor.
prop. 6): moreover, if e=y4-2m, it consists of three
polygons (by prop. 6, and cor. 1, prop. 2), but three is the

least

SSA LOG AND SOUNDING MACHINE. 945

least value of m; hence all the numbers from y to y +2 m
are properly resolved, except y + 2m—1. Now, let @ be
the index, which resolves y + 2m—2 into polygons; and
the same, a, will resolve y + 2m—1 into m + 1 polygons;
but the next value of a = a + 2—~m (cor. 1, prop. 4); which
will resolve y + 2m—1 into m/polygons, or less, (cor. 2,
prop. 5). In general, if e = y + t can be resolved into m
polyyons by the index a, the next index a 4+ 2+~m, will re-
solye e + 1 into m polygons, or less (cor. 2, prop. 5).

JOHN GOUGH.
Middleshaw, October 15, 1808.

iF:

Description and Use of a Sea Log, and Sounding Machine,
invented by Mr. Enwarp Massey, of Hanley, in Stay=
fordshire. |

To the nautical reader the advantages resulting from A

She ists wre _ An accurate
log, that will give a dead-reckoning free from errour, of jop wanted.
nearly so, must be sufficiently obvious; and to others it would
be superfluous to point them out. The principle, on which
Mr. Massey’s patent log is constructed, is not new; but every
application of it to practice has been found defective, aad
this is the difficulty the patentee has had to surmount. To
understand the manner in which it acts, sée Pl. 7, where a, New log dt"
fig. 1, is that part of the log which régisters the distance scribed,
sailed, and is therefore called the register; it contains within
itself a set of wheel work, which operates upon the fingers of
the several indices, 1, 2, and3. bis thé rotator, a hollow
cylinder, made air-tight, and so nearly of the same specific
gravity as water, as to float when drawn forwards with the
velocity of mere steerage way. On this rotator are fixed
four vanes placed obliquely. It is’ then fastened to the ré-
gister by a cord, c, about six feet long*: to the loop-hole

* This cord is shown scarcely one tenth part of its proper length in the
engraving: it would have been an. unnecessary extension of the plate to
fepresent it otherwise, as it may so readily be conceived,

at

’

246 SEA LOG AND SOUNDING MACHINE.

at the other end of the register is secured another line, e, of
sufficient length to extent i the eddy of the vessel’s
wake.

The finger on the index 1 erblines once while the log moves
forward one mile; that on the index 2 moves once round in
going ten miles; that on the index 3 makes one revolution
when the distance sailed is one hundred miles. When the
machine is to be used, all the fingers of the indices are set
to 0, and both register and rotator committed to the water.

As the vessel moves forward, the log must follow, and
from the obliquity of the vanes it is evident the rotator, 5,
must revolve quicker or slower, correspondent to the ship’s
velocity. This rotatory motion is communicated by the cord
¢.to the universal joint d, connected with the wheels, which
consequently revolve with the rotator and cord, and thus the
actual space passed through, in any given time, is registered
on the indices.

Registers the . - Every, occasional or momentary acceleration or retardc~
easy distance ++ on of the vessel, from irregularity of wind, or other causes,
which are either altogether passed over, or very vaguely
_ guessed at, in general, are accurately registered.on this ma-
as chine, which not only gives the actual rate of sailing, but

the actual distance sailed, since the last inspection.

A very little reflection will convince any observer of the
great superiority of this machine over all others which have
been hitherto introduced.

Former at- It may appear rather presumptuous to criticise the la-
failed, have hours of Smeaton, and many others, whose endeavours were
_ not crowned with complete success: but it is necessary to
point out where their plans failed, in order to prove the
very superior advantages of Massey’s log; for though some
of the machines answered their purposes tolerably well un-
der certain circumstances, none of them were nearly correct
under all circumstances, Some were erroneous when the
ship moved less than four miles in the hour, and others
became so when the rate was increased,
and why. In most of the former inventions, the first mover was a
spiral, or a rotator in the shape of a Y, and was generally
attached to a register kept in the ship; and as it was abso=
lutely necessary, that this first mover should be out of the

wake

Its mode of
action.

SEA: LOG AND SOUNDING MACIINE. 247

wake of the vessel, it had a length of fifty yards of cord, or
more, to carry round with it every time it revolved. The
friction caused by this operation was such as to preclude all
hopes of accuracy ; it was useless in an agitated sea, the
rope was very liable to kink, and in fast sailing the rotator
would sometimes fly out of the water*, These circumstan-
ces rendered it impossible, that the rotator should make the
same number of revolutions in passing through a given
space, under different velocities ; and hence inaccuracy was
unavoidable. To get rid of this friction of the long line,
the rotator has, in some instances, been enclosed in a cylin-
der, and aregister been attached to the outside. But though
the defect of excessive friction was thus surmounted, still
greater inconveniences resulted. It may be sufficient to
mention, that the cylinder, not presenting itself horizontally
in the water, was lable to alter its position whenever the vee ,
locity of the vessel was changed, which caused an eddy, or
dead water, to remain in the cylinder; and, of course, the
rotator was liable to err, in proportion as the cylinder lost
its horizontal position.
» After thus hinting at the imperfections of other previous
methods of constructing loge, it remains to point out
wherein Massey’s plan differs.
» Friction is the principal cause of mechanical theories va- Difference of
rying so widely from actual experiment. In some machines — pias
one third is allowed for its effect, while the operation in
others is nearly suspended, and what appeared very plausi-
ble in theory, is found totally useless in practice. Thus the Friction trifling
friction on a rope long enough to extend beyond the eddy of
the vessel’s wake would, in many circumstances, on the old
plan, totally impede the action of the rotatort. Under this
impression,
* Smeaton, in tMe account of hi$ experiments on Sauniarez’s log, in
the Philosophical Transactions, observes on this subject . ‘* Upon mak-
“ ing up the account of this run, 1 found the number of rotations were
“© less by one full third than they ought to have been, compared with

«© the former observations, which affordéd me a convincing proof, that
‘* this instrument was considerably retarded in quick motions ”

+ Smeaton, in the account of his experiments in the work before
guoted observes: “ During this run, | observed that the resistance of
‘6 the water to the line and plate was very considerable, and increased the

© friction

248

Rotator always
horizontal,

and accurately

adjusted.

General pro-
perties of this
log.

Another ad-
vantage it has
in giving usa

‘SEA LOG AND SOUNDING MACHINE,

impression, the friction in Massey’s patent log is reduced to
almost nothing by the following simple contrivance. The
whole log, consisting of the register, a, connecting cord, c,
and the rotator, 6, is committed to the water, by a log line
of sufficient length to reach beyond the eddy of the vessel’s
wake. As the ship moves forwards, the rotator, and cord,
ec, between it and the register, revolve and set the wheels
into motion; nor has the roughest sea been found to prevept
this action.

The rotator also, in this log, is so constructed as always ta
preserve a horizontal position, by being made nearly of the
sane specific gravity as water; which 1s effected by means
of an air tube passing through its centre: an indispensible
requisite, which no former machine possessed; and for the
want of which, they could not preserve that horizontal posi<
tion in fast and slow sailing, which is absolutely necessary ta
obtain any true result.

Another very important improvement consists in the cons
trivance for regulating the rotator, by which means every ro~
tator revolves once on its axis In passing the same space: as
it was found utterly impossible to construct two rotators so
exactly alike as stated by Smeaton, without means of ads
justment.

To sum up the properties of Massey’s patent log, ina en
words it may be observed,

1, It will give the true distance sailed, from stinceag way;
to any velocity with which the swiftest sailing vessel can
move.

2. It not only gives more accurately than the common
log the rate of sailing, but the actual space sailed through
since the last inspection.

3. It is attended with less trouble than the common log,
and no mistakes can possibly-arise from the result it gives.

It remains to point out one great and desirable advantage,
which may very reasonably be expected to resylt from the
use of this log, and that is, a more complete knowledge of

“ friction of the spindle so much, as to prevent it from beginning to
turn, till the plate had twisted the line to such a degree, that when it
¢¢ did seta going it would frequently run one hundred and fifry or two
S¢ hundred turns at once.” ;

the

SEA LOG AND SOUNDING MACHINE. 249

the currents in various parts of the ocean, which has hitherto knowledge of
been very imperfectly attained; as it was not possible to'"
know, with any certainty, whether the wide difference found

between the real distance, and that given by the common

log, was eaused by the known imperfections of that method

of reckoning, or by the operation of currents,

Dr. Maskelyne, in the same work just quoted, further Remarks on
observes: “ There is another argument which adds much vel
strength to the foregoing ones, and greatly enforces a
uniform and correct ‘length of the loghne, on board all
‘ ships; that in many parts of the ocean, especially be-

«« tween the tropics, and near most head-lands, there are
considerable currents, which must iatroduce a fresh er-

‘* rourinto the reckoning; and if this errour should happen

“* te combine with that already produced by a wrong length

‘* of the logline, as it may as well as not, it is not easy to

** say how far the total errour of the reckoning might go,

*< or to what inconveniencies or dangers the ship might be *
«* exposed on that account. But if the just and proper

** length of the logline were used on board of all ships,

‘* they would be then hable only to the errours of the cur-

** rents themselves; and even these, as far as they are con-

“ stant and regular, might be found out and ascertained,

** from the journals of several ships, which would then agree

“© much nearer with one another.’’ And Smeaton observes, and Mr. Smea-
** that itis for want of a means of measuring the way of a '.
« ship through the water, (and this compared with other

«* check observations,) that the drift and velocities of the

*§ principal currents have not already been determined.”

Butadmitting thecommon logline and glass were perfect-
ty uniform in each ship of a fleet, yet the result would still
be too erroneous to expect this very desirable knowledge of
the currents to be derived from a comparison of the several
journals, Massey’s patent log holds out, however, more
than a probability of effecting this important end. It ap- Reckoning to
pears by a letter from Captain Whittle, of the Lord Nelson, Newfoundland
that he found the distance run from the island of L[la, to St. eit niles,
John’s harbour, Newfoundland, by Massey’s log, to agree
with the known latitudes and longitudes of beth places,
within eight miles. Now had he sailed in company with se-

veral

$

n

é

4

“

a

250

From the com-
mon method
of taking
soundings ma-
ny ships lost.

Causes of its
maccuracices.

New method,

Soundings ta~
ken in 30 fa-

‘thoms without

heaving to,

SEA LOG AND SOUNDING MACHINE.)

veral other ships, supplied withthe same log, which had kept
tolerably well together during the whole voyage, and it had
been found (which is more than probable) that all , their
reckonings corresponded with his; the difference between
the true distance, and the distance given by the log, might
with the greatest propriety be ascribed to the operation of
currents; the existence of »which would consequently be
discovered, as far as related to those seas.

The importance of obtaming true soundings at sea must
be admitted by every seaman; and it 1s rather singular, t that
no other method than the common lead has hitherto been
brought into use; as its imperfections are very generally ac-
Lepadeetmeds

Many vessels have been lost, by depending upon. the
soundings taken in the usual way. ‘The dithculty of ob-
taining the true perpendicular, and the uncertainty as to the
exact moment when the lead strikes the bottom, upon which
the accuracy of the result depends, must always prevent the
possibility of obtaining the true depth, while the ship has
any considerable way upon her. Indeed, it has been acknow-
ledged by experienced seamen, during some experiments,
made at various times, in the river Mersey, that they could
not depend upon the common lead, when going five or six
knots in the hour, in ten or twelve fathoms of water. When
the depth is considerable, the vessel must be hove to, which
is an operation attended with great loss of time, and some-
times considerable injury to the sails; and during a chase,
this inconvenience must be particularly felt.

Massey’s sounding machine is as, great an improvement
upon the common lead, as his patent log is upon the common
log. A rotator on the same principle as that to the log re-
gisters the perpendicular descent of the lead, without any
respect to the length of line paid out, which, in the usual me-
thod of taking soundings, is the chief guide to the mariner
in judgiug of the perpendicular depth, and is apt to deceive
him much..

True soundings may be taken with this machine it in shintis
fathoms water, Ebon the trouble of heaving the vessel to,
although she may be going at the rate of six miles in the
hour. True soundings may also thus be obtained in very

deep

SEA LOG AND SOUNDING MACHINE. 95)

‘deep water, where it.is not possible.to take them by the
common lead.

*’This sounding machine is on the same principle as the Pprineiple of the
log, for it is evident, that, if the end e of the register, a, machiue.
(fig-1) were projected into the water, and suffered to des-

cend, the rotator would follow, and register the exact depth,

as well in a perpendicular, as in a horizontal position.

But though the principle of the two machines is the same,
their construction necessarily differs considerably, as will be
perceived on reference to the plate.

. Fiz. 2 represents the sounding machine. a is the sound- Description of
ing weight, containing a register, 1, 2, with two dials: the we

hand of the dial 1 makes one revolution when the weight

has descended twenty fathoms, the other revolves once when

the descent amounts to five hundred fathoms. A rotator, 4,

similar to that attached to the log, communicates with the

wheel work of the dials 1, 2, by means of the rod ce, on which

there are three universal joints, 3,4, and 5. This rod is

supported during the descent of the weight, by the drop, d,

at the end of which isa fork, 6, and a friction wheel, 7.

--When the machine is to be used, a sounding line is fasten- Method of
ed to the ring, e; and one of the vanes of the rotator is slip- re

ped into the spring 8: the rotator will then be in the position
indicated by the dotted lines, x. Theindices must be set at
0, and the cover or lid, f, be shut. The machine must then
be projected perpendicularly into the sea. As soon as it
reaches the surface, the resistance of the water forces the
dotted rotator,.r, out of the spring 8, and it assumes its
perpendicular direction as represented by the rotator &. As
the machine descends, it is evident the rotator will revolve,
and its motion be communicated freely past the friction
wheel 7, and the universal joint 5, to the wheel work of the
dials 1, 2, and thus indicate the space passed throngh in fa-
thoms. Whenthe machine has arrived at the bottom, the
rotator, as it is no longer buoyed up by the reaction of the
water, will fall to the bottom, quitting the fork of the crop
d, which will also fall from its horizontal position, and in its
descent, by means of the locking rod 9, prevent the rotator
from revolving as the machine is drawn up. When at the

bottom,

tS
Gr
tS

No mistake
can arise from
ite

Farther advan-
tages,

Sounding in
60 or 80 fa-
thoms while
going 3 knots
at hour.

SEA LOG AND SOUNDING MACKINE.

hottom, the rotator will be in the position of the dotted
lines y.

This machine, simple in its construction, and scarcely more
hable to accident than the common lead, ascertains, with
the utmost precision, the perpendicular depth, by the mere
act of descent through the water. No mistake can arise from
that common source of errour, the drift or lee-way of the
ship during the time of descent; nor does an operation of
such importance depend upon the uncertain sensation caused
by the lead ‘striking the bottom, on which the accuracy of
the common log altogether depends, and which, it is well
known, frequently and materially misleads the best seaman :
for though a thousand fathoms of line were paid out, in the
smallest depth of water, no inaccuracy could arise, as the per-
pendicular depth, at the point of heaving, would be regis-
tered on the index. The only inconvenience experienced
would be the additional labour necessary for hauling in the
excess of line. The most inexperienced person may use
this machine, without risk of errour, i the most turbulent
sea, and during the night.

The advantages already enumerated would render the
sounding machine of great importance; but there are other
properties of still more consequence.

To heave a ship to, im order to obtain soundings, on a lee
shore, in stormy weather, is a very disagreeable operation,
attended with much trouble, and loss of way; also with con-
siderable danger to the ship’s sails; indeed, it would often,
under such circumstances, be attended with great hazard to
the safety of the ship. To avoid these unpleasant conse~
quences, the master sometimes adopts a measure, which he
conceives to be the less exceptionable alternative, by run-
ning on. without sounding at all.

To prove how much inconvenience and danger are avoid-
ed by Mzssey’s lead, it is enough to state, that soundings
may be taken in depth from 60 to 80 fathoms, while the ship
is under way, at the rate of three miles an hour; and as th¢
rate of sailing may be still materially reduced, without
entirely stepping the vessel, or altering her course, so may
soundings be had, to any depth required, while she is under
way.

In

@EA LOG AND SOUNDING MACHINE. 953

In. order more clearly to show the superiority of this ma- Its superiority

chine, and make it apparent, that the quantity of stray-line “*°™? a
yeered out does not at all affect the truth of the result: suppose
the common lead thrown from the mizen chains of the ship,
which may be represented: bythe point a of the triangle abc,
{fig. 3), and that the ship has moved forwards through the
space equal to the line 6c, while the lead has descended
through the line ac; it 1s evident, that it is impossible, in
this case, to ascertain the exact depth, as a quantity of line,
equal to a 6, would be paid out, whereas the true depth is
equal only to the line a c, which is much less. But the case
is very different when the patent sounding machine is used,
as the operation ceases when it has reached the bottom; nor
is the stray-line, a b, whatever its length, at all taken into
the account.

~-It has been found extremely difficult, and sometimes im- Takes accu-

possible, to obtain soundings in very deep water with the oa ee
common lead, which may perhaps be thus accounted for.

The common line which is used for sounding, though, if left

to itself, it would sink in water, yet its descent would be

much slower than that of the lead, separately; it conse-

quently follows, that the lead must be so much impeded by

carrying the line with it, that when it does reach the bottom,

there will be scarcely any sensible check to enable the sea-

man to know the precise moment. Indeed, if he can ascer-

_tain even this toa certainty, he still cannot depend upon the

truth of his soundings; for if there be the least drift or cur-

rent, the line itself will assume a curve, similar to. that of

the line of a kite in the air. These two causes-will always

‘operate against the perfection of the common mode of

- sounding.

After so fully describing the principle of the patent
sounding machine, it is scarcely necessary to prove, that it
is liable to neither of the foregoing objections; and it may
be sufficient to say, that, as it will certainly find its way to
the bottom, if a sufficient portion of stray-line be allowed
to guard against its being checked in its progress, and
the certainty of its having reached. the bottom may be as-

certained by the arming, there can be no doubt of the prac-
ticability

254

The rotator
does not im-
pede its des-
cent,

as shown by
experiments.

SEA LOG AND SOUNDING MACHINES

tiealnlity of its obtaining soundings, in any depth, and no
reasonable doubt of their correctness when obtained.

From the construction of this machine, it might be ima-
gined, that the rotator would impede its motion through the
water, and that it could not descend so rapidly as the com=
mon lead; but during repeated trials, in thirteen fathoms
water, in which the rotator was frequently detached, and the
lead suffered to descend alone, there was no difference per-
ceptible in the time of their descent, though an excellent
quarter-second stop watch was used during the experiment,
to detect any change. The following table shows how
very uniformly the times of descent corresponded with
the depths in fathoms, during a series of trials made on
the river Mersey, with the patent lead, weighing fourteen
pounds.

The manner of conducting these experiments was such as.
is deserving of perfect reliance. Two pilots, of well-known
ability and experience, were employed: one threw the lead,
and the other, the moment he found, by the slackening of
ghe rope, that the weight had arrived at the bottom, cried,
“ stop,’ to a third person who held the watch.

_ Time of descent. | Fathoms. Time of descent. Fathoms.
2 seconds 22 7% seconds 112
Qt 3 7% iE.
3 4 7% d12EF
5 8 74 12
53 ———-_ 8} 7 —— 12}
6 —— 10 s§ -—— 13
6 10 8 ——— 132
7 —— 11} 6 10

Taken when under sail, at upwards of five knots in the
hour.

cee

Several captains and masters in the navy have made trial
of the. log and sounding machine, and given very favourable
reports of their performance, Of these the two following
miy be selected as specimens.

Sun

SEA LOG AND SOUNDING MACHINE.

San Jofef, 12th Dee. 1806.

2

0

5

Having several times, and in different depths and rates Testimony of

of sailing, tried Mr. Edward Massey’s patent sounding

the perform-
> ance of the

machine, which is, in my opinion, a most excellent inven- sounding ma-

tion, as correct soundings were gained in fifty-five fathoms,
with a strong breeze, going six knots, by only passing the
lead to the quarter-boat, attaching a hand lead about thirty
fathoms from the machine, (which I think, is in such cases
necessary :) and about ninety fathoms of line out: at an-
other trial, to compare the old with the new method, going
five knots and a half, correct soundings were ascertained by
the machine in fifty-two fathoms, by passing the line to the
main-chains, when we could barely get the depth in the
old way, by carrying the lead to the spritsail-yard, notwith-
standing the immense length of a firft rate, and daylight
in our favour; and not even then, 1f we had not had know-
ledge of the depth nearly, that being a check or caution
not to give too much line off the reel, there being no time
to gather in the slack, which would be the case were we
sounding in an unknown place, by the old method. The
invention is the more valuable, as the process is the most
simple, the whole being understood, by seeing it once
in use.

I therefore consider it a valuable improvement in naviga-
tion ; as in frequent, and various cases, soundings could not
be gained without it. -The advantages are many, suchas in
chase, or being chased ; on a lee-shore, or doubtful of it;
and to save time in running for the desired port*.

R. J. NEVE, Captain.

N. B. It will be necessary in the practice of the new
method of sounding, to have line of different sizes, in pro-
portion to the depth of water; as by the ship passing at the
rate of eighl or ten knots, it will require the best of lines
to haul in the lead, and should be made of a much superior
quality to those at present supphed to the navy.

* The honourable Navy Board have adopted the sounding machine
for the use of his majesty’s navy, and have favoured the inventor with
an order for five hundred machines,

H, MM.

256

and of the loge

RADIUS OF CURVATURE.

H. M. S. San Josef, in Torbay, 12th Dec. 1806:
SIR,

In obedience to your orders, we have been particular in
attending to the use of Mr. Edward Massey’s Patent Log,
and from every opportunity that offered during our cruize
we are strictly of opinion, that it has the merit of accom-
plishing the end for which it is intended.

On some trials made with it, and the common log, they
perfectly agreed, at other times they differed a little, but:
last night bearing up for Torbay, with a run of eighty miles in
squally weather, there was a difference of nine miles: but
agreeably to our reckoning the patent log was perfectly cor-
rect; we therefore consider it an important improvement in
navigation, and the more so, as the instrument is simple
and easy to be generally understood.

The chief things necessary to be observed are to secure
the tow-line as near the surface as possible, to prevent the
machine from quitting the water in an agitated sea, and fast
sailing, and not to be less than sixty fathoms long in a first
rate, to prevent it from being affected by the eddy of the
ship’s wake.

We are, Sir,
Your most obedient humble servants,

R. J.NEVE, Captain,
THOMAS MOORE, Master:
To sir Charles Cotton, bart., viceadmiral of the red, &c.

re er errs Bt eae rn

lo tntichensauaarbetaaadttinat oe

iil.

Observations on the Problem respecting the Radius of Cur-
vature. Ina Letter from W. Moore, Ef.

To Mr. NICHOLSON.
SIR,

Tr the following observations on the problem respecting
the radius of curvature, should be found to deserve a
place in your Philosophical Journal, the insertion of them
will greatly oblige,
' Si,
Your most obedient humble servant,
W. MOORE.

RADIUS OF CURVATURE. 957

An attempt to show, that the nature of the problem re= proplem re-
Specting the radius of curvature does not involve in it the specting the rae
consideration of second fiuxions; but that they are made to pba hes
enter into the definitive expression as a matter of mere con- involve second
venience. ser aagie

Definition. If one end, O, of the thread A LD O, PI. vii,
fig. 4, be first fixed to the point O, in a curve LD O, concave
the same way, and afterward the thread be put about the said
curve so as to touch it in every part: then if the other end, A,
of the thread be tightly moved in the same plane with the
curve L DO, the saidend, A, will describe a curve A BI,
called the involute curve to LD O which is the evolute :
and the right lines D B, OL, are said to be-radii of cure
* yature.

It is evident from the method of generation of the curve
A BI, that if at any point D, in the evolute LD O, the
string should cease to unwind itself and the radius DB con<
tinue to revolve about D, asa centre (see figure 5), the
circle thereby described would have the same degree of cur-
vature as the involute at the point B; and that a tangent
drawn to either curve would be common to both. More=-
over, because the said two curves, viz. the involute and
circle, have the same curvature at the point B, and their con-
tinuations one and the same curve, namely, the circle where
radius is D B; the fluxions of the absciss and ordinate of
the one, will be equal to the fluxions of the absciss and ore
dinate of the other, and consequently the same wili hold of
any other order of fluxions whatever. This being pretrised,
let it be required to find a definitive expression for the ra-
dius of curvature of any curve, as ABI. For which pur-
pose let as usual the absciss and ordinate AC, BC, of the
curve A BI, be denoted by x and y; also A B=Z, and put
BE the corresponding ordinate of the. cirele MBN=w,

Then the triangles Bum, BED, being similar, we have

Bu: Bm::BE: BD; or#:z: eee Sawaal Now this
x”

expression is general; but being in terms of the ordinate of

the circle M B N and unequal to BC, the ordinate of the

circle ; it cannot with convenience be applied te curves

whose equations are generally expressed in terms of their.

VoL. XXI.—-DeEc, 1808, S

938 RADIUS OF CURVATURE,

P b nd yy ° @
oa the otvn ordinates: we must therefore in order to adapt it to

radius of cur- practical purposes find a value for v, in such terms as shall
Sie aig be consonant to the characters in which the equations of
Ruxions, curves are generally written, viz. those expressing the ab-
sciss and ordinate: in order to which, let the above expres«
sion be put again into fluxions, and made equal to nothing
(it being a constant quantity) and we shall havew= hee —

: o) 5% Peer 3 :
mm UI mn PIN
—; =o;and Moen nals tee Fe ae __.; therefore, BD =
x XK B— KB. KM BH HBS
= —5j.——; another general expression in terms of the
& R R— Kx

fluxions of the arc, absciss and ordinate of the involute—
but this, like the other is still inconvenient for practice;
yet the difficulty may be removed very easily by expunging
2: for put z*4)*—% into fluxions, and we get «*+j¥

2%; and g—— so that our last expression becomes
=e
ee) Cae cc » 2% *h\ 2
TD pan i ux War) han a +y ' u the
‘ eee RRL YR He eR

general value for the radius of curvature, when both the absciss
and erdinate flow inconstantly : but as all curves may be genes
rated, either by the uniform increase of the abseiss and incon-
stant variation of the ordinate; or by the uniform flow of the
ordmate aad variable flux of iheabsciss ; weare at hberty to as-
sume the first fluxion of either constant as it may suit our con-
venience ; and thus simplifying the expression, avoid the

trouble which would otherwise arise.—Thus, if.« be sup-.

i p ef y” Q
posed constant, the expression will be GT 3 and if f
3
g
ee -2 a Ser
Q . ——ye. fy — 0
be made constant it becomes, ey
SS toe AP, a) *

It is to be remarked, that all those expressions for the
radius of curvature are strictly true and general; yet being
in terms of quantities whose values would be extremely
difficult to find, are not so applicable to practice as that
containing only the fluxions of the absciss and ordinate.
The entry of second fluxions into the definitive expression,

does

; ON THE COMPOSITION OF ALCOHOL. 259

does not imply, that the nature of the problem necessarily
requires it: it arises from the particular artifice which is em=-
ployed in finding the value of w, the ordinate of the circle;
and is a matter of mere commodiousness, suggesting no
other reason for their appearance, than that of a necessary
consequence of such a particular step.

Royal Military Academy, Woolwich,
Oct. 13th, 1808.

Ty.

Essay on the Composition of Alcohol and of Sulphuric Ethe?.
By THEODORE DE SAUSSURE.

(Continued from p. 231.

Sect. III. Analysis of alcohol by detonating its vapour witk
oxigen gas.

I the preceding analysis I remarked, that alcohol, burn py. whole of
ing ina lamp under a closed receiver, diffuses a vapour, that the alcohol not
has an alcoholic smell; it is very probable therefore, that b¥™ed in the
: é : preceding ex-
the whole of the combustible disappearing from the lamp periments.
does not burn. Accordingly I sought a process, that should Its vapour de-
effect a complete combustion of the alcohol; and this [ tonated.
found in detonating a mixture of vapour of alcohol and
oxigen gas over mercury, by the electric spark, in Volta’s
eudiometer.

This process applied to the analysis of alcohol is some- 7) ;.4 gift
what complex. It requires a knowledge of the weight of cult process.
the vapour of alcohol at a given temperature and pressure,
and the determination of the increase of volume of the oxi-
gen gas by the presence of the vapour. The experiment
must be conducted at a temperature exceeding 15° R. [66°
F.] to obtain sufficiently decisive results; and neither the
thermometer nor the barometer must vary during the course
of it, which requires practice and quickness in several of its

manipulations,
$2 I washed

260 ON THE COMPOSITION OF ALCOHOL.

Method of I washed the inside of a large bladder with alcohol seve-
Fie)» and ral times, letting the alcohol stand in it a long time, to take
vapour of alco- up every thing soluble in it, that this might not affect the
hol. expansibility. When this came out wel pure, the

bladder was three parts filled with atmospheric air, two

ounces of alcohol were poured in, and it was stopped witha

cock. The air contained in it was dilated by the formation ~

of alcoholic vapour. At the expiration of eighteen hours I
fitted to the cock an empty receiver intended to weigh the
air. The cock being turned, the dilated air passed alone,
without any liquid alcohol, into the receiver, which was
weighed before and after, the thermometer being at 17° [68°
F.], and the barometer at 26 inches 9 lines during these ope-
rations and those that followed.
Twice repeat- By this experiment, repeated twice under these circum-<
ed. stances, I found, that 1000 cubic inches of atmospheric air di-
lated by alcoholic vapour weighed 433°76 grains; and 1000
inches of the air employed in the experiment weighed before
the introduction of the alcoho! 424°5 grains.
Dilatation of To measure the dilatation the air had undergone by the al-
the gas calcu coholic vapour, I employed the formula of Mr. Dalton, and
Loni rink passed into a barometer a drop of aleohol, which sunk the
mula. barometer 20°5 lines, expressing the elastic force of the va-

pour in vacuo. Applying this result to the formula P

where p = 26 inches 9 lines, and f= 20°5 lines, “ find,
that, the volume of undilated air being equal to 1, it be=
comes 10682 by the conversion of alcohol into vapour; and
as 1:0682: 1 :: 1000 : 936°14, it may be inferred, that 1000
cubic inches of atmospheric air alcoholized contain 936°14
stent skew of atmospheric air. These weigh 397-4.grains; and as the

chesof alcoho- alcoholic vapour occupies the same space as the air dilated
Waigh 36°98 by it, it follows, that 1000 cubic inches of pure vapour aa

gis. alcohol weigh 433°78 — 397°4 = 36°38 grs.
Vapours dif- I need not remind the reader, that, according to Dalton’s
fuse themselves

a amsbeusal experiments, vapours diffuse themselves in the same quan-
tity whatever tity through every gas, that has no chemical action on
the gas. them*. I chose atmospheric air for finding the weight of
Atmospheric * | kept atmospheric air in. contact with alcohol a long timein a jar
air very slowly over mercury. In five months the air had undergone no sensible change,
altered by al: but in twelve it had lost ‘01 of oxigen gas,

_- gehol. the

ON THE COMPOSITION OF ALCOHON. 261

the vapour, because I could not employ pure oxigen gas in
largequantity otherwise than at the point of extreme moisture;
and if it had got dry, or if the external air had any way
penetrated into the bladder, there would have been some
errour in the calculation of the weight. Trepeated the ex-
periment however with oxigen gas, and found only a trifling
difference, which I ascribe to the causes just mentioned.

To effect the combustion of alcoholic vapour, I prepared Alcoholic va-
alcoholized oxigen gas, by passing some drops of alcohol Po)" wweed
into a jar filled with oxigen gas over mercury. I afterward gas
withdrew the superfluous alcohol, that could not rise in va-
pour, by introducing dry unsized paper, and taking it out
through the mercury, repeating this operation till the paper
came out perfectly dry, and then emptying the dilated gas
into a fresh jar, I had previously satished myself, that une
sized paper would not condense the vapour of alcohol.

This alcoholized oxigen gas was introduced into a Volta’s would not de
eudiometer filled with mercury, but I could not set it on fire tomate by the ©

; ; . _ €lectric spark
by the electric spark. I was equally unsuccessful on adding
pure oxigen gas in various proportions. The alcoholic va- .
pour was too much rarefied in the oxigen gas to take fire. y
When I added a very small portion of hidrogen gas to the withouta mix-
alcoholized oxigen gas, the electric spark produced complete ae i
combustion of the alcoholic vapour. The same effect took ofa hedeleaa
place, when I substituted. an mappreciable quantity of alcohel.
liquid alcohol instead of hidrogen gas. The vesicular va-
pours, produced no doubt by this alcehol, answered the pure
‘pose of hidrogen gas: but in an accurate experiment this
addition of liquid.alcohol was inadmissible, as it was impos-
sible to ascertain its quantity. .

Accordingly to 500 parts by measure of alcoholized oxigen The experi-

s : ‘ ment described,
‘gas [ added 99°2, or near a fitth, of hidrogen gas, and de-
tonated the mixture. The combustion, taking a mean of
three experiments, gave a residuum, which, being analysed
by lime water and by Volta’s eudiometer, contamed 342-59
parts of oxigen gas, and 46°69 of carbonic acid gas. [ omit
the nitrogen, which was found mixed in a smali quantity with
the oxigen gas both before and after the combustion, and
acts no part that can be estimated. I must observe, that,
when I opened the endiometer immediately after the detonae

Home

262

Calculation of
the products.

Elements of
alcohol,

This analysis
more accurate
than the for-
mer. '

Alcohol in
Desens sora
water.

ON THE COMPOSITION OF ALCOHOL,

tion, and while it was full of fumes, these were perfectly-
void of smell.
The 500 parts of alcoholized oxigen gas contained before

the combustion, according to the expansion of alcoholic va-

pour; only 468° 07 parts of oxigen. The alcoholic vapour
therefore and hidrogen gas added occasioned the disappear
ance of 468°07 — 342'59 = 12548 parts of oxigen gas. The
hidrogen gas added condensed half its bulk, or 49°6 parts.
The 500 parts of alcoholic vapour therefore employed in
their combustion 125°48 —.49°6 = 75°88 parts, for ming
46:69 parts of carbonic acid gas, and a certain quantity *
water. | | Ka

If we consider the parts above mentioned as cubic inches,
and to 500 of these substitute their equivalent weight of
alcohol, we find, that 18°19 grs, of alcohol consume in their
combustion 75°88 cubic inches of oxigen gas, forming some
water, and 46°69 cubic inches of pestle acid gas, ‘These
results by a similar calculation to that made for the slow
combustion of alcohol, sect. i, show that 100 parte of this
as eo contain

Carbon FRO Seeserseeeeesoseerecce 43°82
Hidrogen eeeerece oe esos see oe Seoovee8 15°82
Oxigen ®CCoecererteoeoeee0e S82 e288 LE8 41°36

1 00. \

‘These elements may be deduced from the following ex-
pression. Ten grains of alcohol consume for their combus-
tion 38°54 cubic inches of oxigen gas, the thermometer be-
ing at 28 inches and the thermometer at 10° R. [54° 5: F, oh
forming water, and 23°67 cubic inches of carbonic acid gas.

This analysis, in which the whole of the alcohol was con
sumed, must be more accurate than that made by slow com-
bustion, sect. II. I shall presently show, that a small AR:
tity of nitrogen is to be included 1 in both,

Sect. IV. Examination of the water produced by the com=
——- bustion of alcohol.

Boerhaave and Geoffroy observed, that the vapour
formed by the combustion of alcohol was 3 water. Lavoisier
PRAT Fs ciel found

ON THE COMPOSITION OF ALCOHOL, ‘263

found by means of an apparatus invented by Meusnier*,

that the weight of this water exceeded that of the alcohol

consumed. In this process all that is formed is not col-

lected, because this process is conducted in open vessels, in

which the air is continually renewed by a rapid current, that

carries out of the apparatus a considerable portion of the

vapour before it has time to condense. In bu rning 100 parts

of spirit of wine Lavoisier collected about 116 parts of wa-

tert. My analysis, sect. Lif, shows, that this aqueous pro- 100 p. alcohol
duct should amount to 132 parts for 100 of perfect alcohol: produce 192 ,

<8 : 5 . Water.

but Lavoisier did not employ this, which would have af-

forded a reault nearer to mine. As it isimpossible to make

this comparison with accuracy, I contented myself with

examining whether the water produced by this process were

pure.

The water obtained from aicohol by the apparatus of The water
Meusnier, or more simply by burning it in the open air un- ©*4™minec,
der the mouth of a large glass receiver, which condenses
the aqueous vapours on its sides, so that they drop from its
mouth, has not the alcoholic smell observed in the product
of combustion under a close receiver, sect. Il; because in
* ‘the latter the alcoholic vapour is retained, while in the open
air it is dissipated, leaving as a residuum only the less evae
porable fluid with which it was mingled.

This liquor is insipid: it has the same specific gravity 8 Its properties,
distilled water: it does not change the colour of sirup of
violets or of infusion of htmus: it is not precipitated by |
acetate of barites, nitrate of silver, or limewater.

Two ounces of water obtained from the combustion of Residuum left.
alcohol in the open air under the mouth of a glass receiver by it.
were evaporated to dryness, and left as a residuum a thin
transparent varnish, that weighed { of a grain, and attracted
moisture from the air. The solution of this varnish in a
‘small quantity of water was rendered slightly turbid by oxa-
late of potash, The combustion of spirit of wine rectified The same by
without addition afforded the same result. This residuum alcohol rectifi-

* For a description of this apparatus see Lavoisier’s Elémens de Chi-
mnie, vol. II, p. 189, Ist. edit. .

+ Lavoisier’s (posthumous) Mémoires de Chimie, vol. il, p. 281.
appeared
rd

264 ON THE COMPOSITION OF ALCOHOL.

ed without ad- appeared to me owing in partto the lime and potash, which
aio. T have found in the ashes of alcohol by other experiments.
They are held in solution by acetic acid formed by the com-
The watergrew bustion. This water, kept in a phial half filled with it,
mouldy. : : :
after some months deposited a slight mouldiness.
Muriaiicacid At the approach of muriatic acid this fluid diffuses co~
elicitsammo- _. ; eal 5 ‘ sates
~ niacal vapours P!Ous ammoniacal vapours. ‘This efiect is more striking,
from it. when the water has been collected by Meusnier’s apparatus,
because in this process the ammonia, or rather the acetate
of ammonia, has less time to evaporate. That I might not
be mistaken with respect to the nature of these vapours;
and to collect a part of the ammonia, which is volatilized
and lost in the atmosphere in proportion as the water is pro=
With this acid duced; I poured a few drops of muriatic acid into the phial,

it forms mu- . : Sykes . : 5
riate of ammo- W@!ch in Meusnier’s apparatus 1s employed to receive the

nia. liquid formed by the combustion. After having obtained 42 _

oz. of this water, which was thus mixed with muriatic acid,
I subjected it to-spontaneous evaporation in a place where I
could not suspect the presence of any ammoniacal vapours,
and obtained a residuum contaiming 33 grs. of muriate of
ammonia, perfectly characterized by its crystallization and
other properties. It was at first mixed with a small quan-
tity of muriate of lime and muriate of lead*: the deliques-
cent salt was separated by elutriation; and the insoluble
metallic salt by dissolving the residuum in distilled water,
Greater partof J] could not judge by this result of the quantity of nitro-
the ammonia- : : : iets
cal gas lost. $e contained in alcohol, because the vapour of muriatic
acid formed a smoke of muriate ef ammonia, the greater
part of which escaped out of the vessel employed to receive
it.
Theammonia Jt js not probable, that this ammonia was owing to the
not produced fete : i :
by the azote in Combination of the hidrogen of the alcohol with the nitro-
the air. gen of the atmospheric air, for it has been seen, sect. IT,

that the latter was not condensed in the combustion of the

Lead dissolved The worm of my apparatus is of lead. In this case the water pro-
— duced by the combustion of the alcohol held the metal in solution pro-
Fi bably by means of acetic acid. The water thus obtained gave a black
precipitate with hidrosulphuret of potash, even when there was no mu-

riatic acid in the receiver; but it did not produce this effect, when it was

collected from alcohol burned under a glass jar.

alcoho

~—

ON THE COMPOSITION OF ALCOHOL.

265
alcohol. Besides it will be shown by more direct observa-

tions, perfectly free from objection, that alcohol contains

this element.

This result is of importance to the theory of fermenta-

tion.

-Mr. Thenard had remarked*, that the nitrogen, which is AeA ee,
an essential part of yeast, disappears in the vinous fermen- sential part of
tation. This element was not then found among the pro- 7°
ducts of this process, but we shall see, that it enters into the
alcohol.

The ammonia contained in the liquid formed by the com- yy. ammonia
bustion of alcohol appears to me neutralized by acetic acid. neutralized by
I have poured a few drops of potash into two ounces of this ““°"* ae
water. The alkali, which was in excess, was saturated by
carbonic acid, and slightly dried in the open air, I washed
the whole with alcohol, and the decanted liquor afforded by
evaporation a very deliquescent salt, which had all the other
properties of acetate of potash, and weighed 11 grain.

All the trials I have just mentioned of the water obtained The water
from perfect alcohol, repeated with water obtaimed from hee
spirit of wine rectified without muriate of lime, gave the 1 eRe hae
same results. They showed, that it contamed ammonia, 2™monia, ace-
acetic acid, and lime, and probably a little potash: but ali (°; se ie
these substances were in such small quantity, that they potash, but in
could not have much influence on the proportions of oxigen, Be een .
hidrogen, and carbon, assigned to alcohol by my last analy-
sis, sect. III, where I considered the fluid formed by burn-
‘ing it as pure water.

Sect. V. Analysis of alcohol by means of a redhot tube of

porcelain.

Several chemists have noticed with more or less accuracy 4 natysis of al-
the nature of the principal products afforded by alcohol in cohol by pass-
: 5 . ‘od Hot, hey oe through a
passing through a tube of porcelain heated red hot. EY scituahaunre
have observed water, oxicarburetted hidrogen gas, and car- lain tube.
bon; and lastly Mr. Vauquelin mentions a crystallized vo-

latile oilt: but they have not obtained from these products
# Essay on Vinous Fermentation by Thenard: Annales de Chimie vol.
XLIX, p, 294: or our Journal, vol. VI, p. 33.

+ Fourcroy’s Chemistry, vol. VII, p. 155; or English edition, p. 207.
a deter-

266

Pracess de-
scribed,

Results.
Charcoal,

with a little
potash, lime,
and perhaps
silex.

Concrete es-
sential oil,

and a thick

brown oil, both
smelling strong a very

ef benzoin,

ON THE COMPOSITION OF ALCOHOL.

a, determination of the number and proportion of the ele«

ments of alcohol... I have attempted however, to attain a
knowledge of these by the same process.

Through a red hot tube of porcelain, glazed internally, I
distilled 2183 grs. of perfect alcohol. The products passed
from this tube into a glass worm* surrounded with cold wa-
ter, and thence into a small globular receiver, which retained
the liquid products, and allowed the gasses to pass on to the
pneumatic trough. |

The retort, which introduced the alcoholic vapours into
the porcelam tube, was kept at a temperature between 40°
and 50° R. [122° and 144° F.].. The distillation continued
twenty hours. I conducted it slowly, that scarcely any of
the alcohol might escape decomposition in traversing eight
inches of redhot tube. From this process I obtained,

1. In the porcelain tube 4} ers. of charcoal, which sepa
rated in the form of a thin film rolled up like a seroll, and
several inches long. ‘Fhis charcoal, being incinerated ina
platina crucible, left about a grain of ashes, in which I dis~
covered, by lixiviation with water and solution in muriatic
acid, the presence of potash, lime, and an insoluble resi-
duum, which might be silex. Mr. Proust had sk ed found
silex and lime in alcohol.

2. The glass worm was lined with the crystallized essen
tial oil discovered in this process by Mr. Vauquelin. These
crystals presented themselves.to the naked eye in the form
of thin, transparent, white, and yellowish scales: but with
the microscope some of them exhibited quadrilateral prisms
with diedral summits. They are. very soluble in alcohol ;
and the solution becomes milky on the addition of water, if
the alcohol be not too abundant. These crystals, as well as
thick brown oil with which they are mingled, and
which is scarcely volatile at the common temperature, have
a strong smell of benzoin. The weight of these two oils
collected and added together, both in the worm and m the
receiver, amounted to 4 graims. The receiver contained but

half a grain.

* When I used a leaden worm, the liquor passing through it held
some lead. in sobution,

Be I

oe

ON THE COMPOSITION OF ALCONOL 267

- I found in the receiver, beside this small quantity of Water with a
» 196 gis of colourless water, the specific gravity of which Aegean,
was 0°998, indicating a mixture of 1932 ers of water, and
2% grs of alcohol. These 23 grs therefore are to be deducted
from the 2183 subjected to analysis.

The water 1 have just mentioned had a smell both of smelling of
benzoin and of vinegar: it reddened sirup of violets, and isi pd
infusion of litmus: it diffased ammoniacal vapours at the dening biue

tests, and emit-
approach of muriatic acid: it was not precipitated by lime fing ammo
water, or by nitrate of mercury, but was rendered shighily cal vapours,
turbid by nitrate of silver. This circumstance, added to the
smell of benzoia, led me to suspect the presence of benzoic
acid,

To find the quantities of the Fanaheista principles contained Analysea,.
in this water, I added it to a similar Hawes obtained by the
same process in another trial, and divided the mixture into
three parts of 100 grs each.

The first, evaporated to dryness in the temperata: ¢ of the it left on evae
atmosphere, left at the bottom of the vessel a transparent Debt ee
varnish incapable of being weighed. duum,

The second portion was mixed with crystallized carbu- with carbonate
nate of potash, which dissolved in it with effervescence. The RAM eget at.
solution, evaporated to dryness, left a residuum, on which ¢d acctaic,

I poured alcoho]. The decanted liquor left by evaporation

a white salt, which on exposure to the air speedily resolved

itself into a fluid, except an infinitely small quantity of a

salt i in stellar crystals, resulting probably from a union of

the potash with the acid that precipitated the nitrate of sil-

ver. The saline substance that deliquesced was acetate of

potash. Its quantity in the dry state would have been for

. the 196 grs of liquid I examined 0:9 of a grain, which in-

dicates 0°55 of a grain of glacial acetic acid in the whole

aqueous product of this analysis,

_ Lastly, the third portion was mixed with muriatic acid, and with wir
to saturate the ammonia. This mixture furnished by eva- cael ie
poration crystals of muriate of ammonia, but the quantity monia.

was too small to be weighed.

’ From this examination the 193% gers of water obtained Its contents.
from the decomposition of the alcohol by a red hot tube

contained acetic acid in excess, ammonia, and probably ben-
zoic

268 ON THE COMPOSITION OF ALCOHOL.

zoi¢e acid: but as the weight of all three together amounted
to about ;3, only of the fluid that held them in solution, it
may be considered as pure water, without any risk of errour,
in an analysis like the present.
Oxicarburetted 4, The oxicarburetted hidrogen gas, the barometer being
ra th i at 27 inches, and the thermometer at 17° R. [704° F.],
occupied the space of 7199 cubic inches; and weighed, the
day after it was collected, taking a mean between the weight
of the gas that came over at the beginning, middle, and
end of the process, 1786-61 grs*. Though the heat of the
tube did not perceptibly vary, the gas obtained at the be-
ginning of the experiment was lighter, and contained less
earvon, than at the end. This was owing to the charcoal
deposited by the alcohol accumulating gradually m the
tube, and reacting on the fluid that was decomposed in
proportion to this accumulation. However slowly I con
ducted the distillation, I could not prevent the gas from
carrying over with it pretty copious white fumes, the weight
of which I could not directly calculate, and the loss of
which occasioned a deficiency in the results of the analysis.
These fumes smelled of benzoin; and appeared to me to af-
_ ford on condensation similar products with those collected
in the receiver, namely, a great deal of water, and a very
small quantity of oil. The latter could only be in very
small proportion; for, on detonating the gas immediately
after its developement, and while these fumes were sus
pended in it, I did not obtain more carbonic acid gas from
the combustion, than when it was detonated after the fumes
bad been condensed in the water under the jars. The un-

Composition of * At 28 inches of the barometoy therefore, and 10° [544°] of the

the gas affected thermometer, 1000 cubic inches of this gas weigh 266 grs. This result

by the Manner gi Fors a little from that of Mr. Cruikshank, who makes it 237 in the

of conducting as <4 fe :

the process. same circumstances. I have performed this experiment three times, ;
changing the diameter of the tube a little, and likewise its inclination
in the furnace, and each time | found a perceptible difference in the
weight of the gas and its composition. But the sum of all the pro-
ducts, in each of the experiments, afforded similar results for the
composition of alcohol, Thus it appears, that we should be liable to
considerable errour, if we did not compare together all the products of
pach experiment.

certainty

ON THE COMPOSITION OF ALCOHOL. 869.

certainty left by the composition of this vapour however
_ ean affect only an 11th part of the alcohol subjected to ana-
lysis.

On adding together the weights of the immediate pro- Immediate pro-

& ducts of the de-
ducts of the whole process, we find, that 2180°5 grs of al- ete 5
cohol afforded the alcohol.

Gaseessecsccesccess 178661 ers
Water-.-cseseeeeeeee 193°50
WOW echo e 6, ale Sruia 0 uber A

AC vAneGalleiess(<\e\e stele ere 3°25
PGES sia ces sios' eos ace 1

1988°36
Deficiency from fumes, chiefly aque-
OUS eeceeeseeseeeeser ss eoeoepsesees 192°14

or

2180°S

Analysis of the oxicarburetted hidrogen gas.

The 7199 cubic inches of this gas contained no carbonic Analysis of the
acid gas, They were collected in eighteen jars, all of oxicarburetted
: . : . : hidrogen gas.
which were examined eudiometrically. I shall give here
the mean of these eighteen anaiyses, deducting the atmo-
spheric air contained in the vessels previous to the distilla-
tion. With 100 parts of the oxicarburretted hidrogen gas
were mixed 200 of impure oxigen gas, consisting of 190
oxigen and 10 nitrogen. .The mixture inflamed by the elec-
_ tric spark left for a residuum some water, and a mixture of
carbonic acid gas, oxigen gas, and nitrogen gas, occupying
together the space of 156°5 parts. These were washed with
lime water, and analysed afresh by Volta’s eudiometer, add-
‘ing to them hidrogen gas. I thus found, that they con-
tained

Carbonic acid gas-+++++ 78
Cxigen gas eovseeneeso 65:93
Nitrogen gas-+++eesces 12°57

1506°5.
These

70 GN THE COMPOSITION OF ALCOHOL.

19

These results show, that the 12407 parts of oxigen gag,
which disappeared to effect the combustion of 100 parts of
oxicarburetted hidrogen were employed to form 78 parts of
carbonic acid gas, and to burn (124°07 —78) K°2 = 92°14
parts of bidrogen gas belonging to the oxicarburetted hi-
drogen gas. Thus we find, that 100. parts of the latter
contain 2°57 parts of nitrogen gas, If by the rule of pro-
portion we estimate from this the results of 7199 cubic
inches of oxicarburetted hidrogen gas, weighing 1786-61
grs, we shall find, that they would have produced by their
combustion 5615°2 cubic inches of carbonic acid gas, con-
taining 945°59 grs of carbon; that the oxigen gas would
have burned 6633-2 cubic inches of hidrogen gas, weighing
212°44 ors; and lastly, that the whole of the oxicarburetted

Analysis of the hidrogen gas contains 185 cubie inches of nitrogen gas,
O@xicarburetted * 4: ”
istiupen pes. weighing 76°77 ers. ;

If we add together the weight of the elements just cal-

culated, we shall have, in 1786°61 grs of oxicarburetted hi-

drogen gas,

Carbon «eeeeeseeees O45'50
Hidrogen- - eeoeeseen08 212°44
Nitrogen +++sereeeses 7077

1234°80
Deficiency +seeeeeess 55181

—_

1780°61.

The residuum of the combustion of the oxicarburetted
hidrogen gas appeared to me to be nothing but water, ex-
cepting the carbonic acid gas and nitrogen, that have been
mentioned. Thus the deficiency we find on adding toge-
ther the elements of this analysis must be ascribed: to the
elements of water, which existed in the oxicarburetted hi-
drogen gas not in the state of water or aqueous vapour, but
in a state in which they were united and as it were con-
founded with the other principles of this gas. If we substi-
tute for this deficiency therefore the elements of 551°81 grs
of water, we shall find, that the 1786°61 grs of oxicarbu-
retted hidrogen gas are composed of

Carbon

ON THE COMPOSITION OF ALCOHOL. 971

“Carbon ccessevceees 945°59 Its constitnent
Oxigen eseecssseeee 485°59 principles,
Hidrogen .eeee. e+ 278°66
Nitrogen cesceseese 76°77

1786'61*

To come at the whole of the carbon contained in the Carbon in the
2180°5 ors. of alcohol I decomposed, we must add to the a
945°59 grs. of carbon in the inflammable gas the 32 grs.
from the charcoal found in the porcelain tube, and that of 4
grs. of oil which might amount to about 3 grs. These added
together make 951°84; and thus 100 parts of alcohol contain
43°65 of carbon.

To find all the oxigen of the alcohol, we must add to the Onend in the.
285°59 ors. of oxigen belonging to the inflammable gas the “obo
oxigen of 193°5 grs. of water in the receiver adapted to the
worm. Thus the sum of oxigen was equal to 485°59-+ 170°28
=655°87 grs. From 100 parts of alcohol therefore we should
have 30°12 of oxigen.

To obtain the whole of the hidrogen of 2180°5 grs. of alco- Hidrogen in
hol, we must add to the 278°66 of hidrogen found in the oxi- the alcohol.
carburetted hidrogen gas the hidrogen of the 193°5 grs. of
water collected in the receiver, and the hidrogen of 4 grs. of
oil, which might be about 1 grainf. The sum of these is
302°88 grs.; so that 100 parts of alcohol would have furnished
13°89 ers. of hidrogen.

Adding to these elements the quantity of nitrogen I found Nitrogen and
in the inflammable gas, and lastly that of the ashes obtained ashes. —

@ This gas therefore contains in 100 parts by weight,

Carbon @eeomwesneeoae @eeeeogeeeeoe 52°9
ORIEN, So :0r0 jos ciale aisle salma eiiecias) UFR
TAI Q POD | 56 j0:0 ais, ols 4 ale «ej «= wie ve uk DIO

Nitrogen eves sesceerteeseeegease 43

100.

-

““f This oil does not make the five hundredth part of the weight of the
alcohol I decomposed: so that in the present analysis, which is merely
an. approximation, I might have neglected this product; and_there-
fore it is of little consequence, whether the composition.1 ascribe to it

be just.
Z by

272

Sum of these.

Deficiency to
be supplied,

Real propor-
tions of the
elements.

Results ageee
with those in
Sect. 2.

Alcohol recti-
fied alone gave
similar results.

ON THE COMPOSITION OF ALCOHOL.

by the incineration of the charcoal, we find, that 100 parts of
alcohol produced.

Carbone+ecccsscvceses 43 65
Oxigen++cereseveseos 30°12
Hidrogen +e+ees.ceees 13°89.
Nitrogen evsececeeees 3°52
ASHES <csuvesscccsss ('04

———

91 22
Lids slee cece eect 8°78

100.

I noticed at the commencement of this analysis, that this
loss was owing to fumes that contained a great deal of water,
and an infinitely small quantity of oil, carried into the pneus
matic trough by the oxicarburetted hidrogen gas. If for this
loss we substitute 8°78 parts of water, we shall find, that 100
parts of alcohol contain.

Carbon+«sccccscccees 43°65
Oxigensessescesoeees 37°85
Hidrogen se+e+escsees 14°04
Nitrogen seeessesesee 3°52
Ashes ceccesessessesse (04

100°

The results of this analysis are nearly similar to those I ob-
tained by the detonation of the elastic vapour of aicohol in a
Volta’s eudiometer, section III, setting aside the nitrogen,
which I could not calculate in that process, and which re-
mained confounded with the water in the state of ammonia, if
not almost wholly with the 41°36 parts of oxigen, which that
analysis ascribed tothe alcoho]. If from these 41°36 parts of
oxigen we substract the 3°52 of nitrogen we have just found,
the two analyses will agree better than could have been exe
pected from such a complex process.

I analysed by means of a red hot tube spirit of wine recti-
fied by simple distiljation, and found no difference of impor-
tance

IMPROVED MUFFLES, O73

tance between the two results, when I deducted the quantity
of water in this spirit calculated from its specific gravity.

(To be concluded in our next.)

V.

Description of an improved Mode of constructing Muffles for
Chemical Purposes, by Mr. EoDMunp TurRre tt, No. 40,
Rawstorne-Street, Goswell-Sti eet Road*.

Havine experienced much inconvenience in the common Common
mode of mould-
ing mufftes in-
chemists, enamellers, &c., I beg leave to lay before your convenient,

mode of moulding mufiles on wooden blocks, for the use of

praise-worthy Society, an -improved method, possessing the
following advantages: namely,

First, By this new method of moulding muffles, coarser and Advantages of
cheaper materials may be used than can be employed in the pe ela
common mode; and which also gives them the valuable pro-
perty of resisting a greater degree of heat.

Secondly, That much time will be saved by this improved
method of manufacturing them, must be allowed, when the
two modes are compared.

Thirdly, The certainty of making them without cracks or
flaws, and with coarser materials, will appear obvious, when it
is considered, that by this improved method, they are inter-
nally moulded instead of externally; by which means the
strength of the operator may have its full effect, in firmly
compressing the composition into the mould.

In the old mode, the workman, after having spread Disadvantages
the composition upon a cloth, guessing at its thickness, eae ee
bends it over the block in the best way he can; and by thus
disturbing the composition, he must needs make many cracks
and flaws, which can be but imperfectly closed in smoothing
the surface of the muffle while upon the block; the evil con-
sequence attending which is, its being subject to fly or crack

* Transactions of the Society of Arts, for 1807, p. $8. Ten guineas
_ were voted to Mr. Turrell for this invention,

Ne XXI.—Dec. 1808. T when

274

Farther advane
tages of the
new method,

IMPROVED MUIFLES.

when exposed toa great heat ; and it will also be plainly seen;
that, in the old mode, a great disadvantage is felt by the sides
of the muffle, while in its wet state, hanging from its centre,
which also tends to crack it, as there can be nothing applied
to assist it in this case, but by employing a greater proportion
of cohesive clay in the composition, which, however, produces
little if any advantage; whereas in the mode which I have
invented, this fault is entirely obviated, and the composition,
by its contraction in drying, assists the extrication of the muf-
fle from the mould.

Fourthly, With respect to simplicity, this new mode will
be found to possess a very great advantage, for a boy of
twelve years of age may he taught to make them in a very
short time.

The fifth advantage of this improvement, and of equal con-
sideration, is the cheapness of the article; the price of which
has been reduced nearly one third to the consumer; and
when the superior quality of them is taken into consideration,
it may fairly be said to be one half. I mean, when regard is
had to their superior quality; and that the muffles may be
used over again when broken and ground, with a much less
proportion of cohesive clay than in the old mode; and this
T conceive to be no inconsiderable advantage; for it is
well known, that when the old muffles or broken crucibles
ean be used without much fresh clay, they are far superior to
new materials.

Sixthly, The muffles made in the old way are seldom of

‘equal thickness; whereas those made according to the method
‘which I have the honour to present before the Society, will be

Descriptzon of
the method of fig, 1, which m

making the
mufles.

found to possess that necessary quality in perfection; for, if

a hundred are made from the same mould, they will be all of
the same thickness,

Description of the Moulds and Implements.

The first mould for this purpose isa tin one, Plate VII,
ay be made from a piece of tin the size of the
arch, being bent so as to form such a concavity as may best
suit the purpose to which it is to be applied. This being done
two square pieces of tin, aa, must have an arch cut out of

them,

O

09 972

UV,

PM Uf Fl

Yy YY Ypres NB U0 Uf

SOY suospoyoyy

CT Ou

~2

VLE Ee uno

IMPROVED MUFFLES. 275

them, of such a size that the diameter thereof may be about Description of
three fourths of an inch less than the diameter of the concave piesa the .
piece before stated ; these, being soldered to each end of the muffless
first- mentioned piece, will form a stand for the hollow part of

the mould, and the thickness of the muffle moulded in this

will be exactly determined by the edge at each end. A piece

of hollow tin, 6 6, may be soldered along the top edge of the

mould, to form a better resistance to the great pressure with-

in. The next part of this mould is a flat piece of tin, fig. 2,

cut exactly to fit the inside of the mould, the use of which is,

-to furm a solid back to the muffles used for chemical pur-

poses.

‘The second tool for this purpose is a piece of sheet brass,.
fig. 3, about six inches long and one broad, which, being bent
in a semicircular form, and screwed to a piece of wood ex-
tending beyond its breadth about an inch, is used for cutting
the small air holes c (fig. 11), in the aforesaid muffles.

The third is the tool or frame, fig. 4, for preventing the
contraction of the muffles in drying, which is made of fonr
pieces of beech, about three quarters of an inch broad, and
half an inch thick; the length must be adjusted to the mould
of the muffle; two of these being laid parallel within the in-
side of the mould, and being joined across by the other two,
the ends of which should extend so far beyond the outer edges -
of the other two, that they may rest upon the edges of the
muffle mould, and thereby prevent its falling into the mould,

The fourth is the tool for spreading the composition into
the moulds, which is formed of iron or steel, (fig. 5), about
thirteen inches in length, one inch and a half broad, and
about one eighth of an inch thick; its face under 4 being
rounded in such a manner, that its curve may exactly fit the
jnner curve of the muffle mould, (fig. 6, is a section of it),
This should likewise have a point or tongue, extending from
each end, long enough to be bent in the form ofa bricklayer’s
trowel, and by the wooden handles which must be put on,
hanging down, it will be found, that, as it is moved either .
backwards or forwards, it will always present an edge to smooth
the composition, and condense it in the mould.

The fifth is a frame (d @), fig. 15, of which the bottom and

T'2 farthest

276

IMPROVED MUFFLES.

Description of farthest side are only shown, and in which frame ‘the tin

th hod of : : Sots
ett. . mould, fig. 1, is placed, simply constructed by joining two’

makieg_the
mufiles.

pieces of wood, the one as broad as the bottom of the mufile
mould, and having two narrow grooves (ce e), cut init, so that
the edges of the tin mould may be confined therein. The
other board, being joined to this at its edge, should come up
so high asjust to be under the edge of the mould.

The sixth is the tool for cutting the muffes of different
lengths (fig. 7), and is made of a piece of wood, to the end of
which is fixed a thin piece of brass (f), which, extending
about one inch and a quarter beyond the tup of the wood, is
bent at right angles, and made thinner at the end, that it may
the more conveniently cut the muffle. Under this piece of
wood is used another straight piece (g), with two steady pins,
which, being shifted at the will of the workman, will cut them
of any length.

The seventh ia the mould for forming the bottom of the
close muffle (fig. 8), which is made of a mahogany or - oak
plank, about sixteen inches long, ten wide, and about three
eighths of an inch thick; upon this is fixed a ledge on each
side, one inch broad, and nearly half an inch thick, and at
each end a ledge of the same kind is placed, at such a distance
as is best suited to the length of the bottom required. Fig. 9
and 10, are circular moulds for muffle bottoms of dial plates.
Fig. 11, a complete muffle standing on its bottom. Fig. 12, a
roller for rolling the composition in the first mould. Fig. 13,
a tool for making ‘small holes in the muffle.

The usual composition for making muffles is as follows: viz.
two parts pipe clay and one part sand, such as is used by the
bricklayers, sifted, and mixed together to a proper consist-
ence; this is very expensive, on account of the high price of

pipe clay, which is about-ten shillings the hundred weight,

whereas | employ in my improved mode of making them the
coarser kind of Stourbridge clay, which can be had at the
glass-houses, in the ground state, for six sbillings the hundred
weight; and this I sift also, to separate the finer part, which f
employ for making other smaller articles necessary in my bu-
siness ; using ohly the grosser or coarser part for muffles, to
which I add one eighth part only of pipe clay,- mixing them

well

IMPROVED MUFFLES. 377

well together with water, soas to form a mass of a pretty thick Description of
‘ i : i .... the method of

consistence. ‘The tin mould being first greased, I place it in jnaking the
the frame, fig. 15, shown under fig. 1, and having spread the muffies.
composition in the meuld, and smoothed it with the spreader,
fig. 5, till the mould is quite full, the flat piece of tin is then to
be well greased, and thrust in at one end of the mould, and
the back of the muffle is then formed by spreading the com-
position, and firmly pressing it against the part already form-
ed. The next thing to be done is to cut the holes in the sides
of the muffle, which is done by pressing the semicircular cut-
ter, fig. 3, into the sides thereof, while itis yet wet, and bring-
ing the piece out entire: the tin mould must now have the
frame, fig. 4, put on, to keep the sides of the muffle from con-
tracting; and being set up endwise, and a little inclined, it
must be dried in the sun, until it has shrunk sufficiently to
leaye the mould, after which it must be completely dried and
burned in the usual manner.

The composition of the smaller implements, or muffle bot-
toms for dial plates, for the mould figs. 9 and 10, is made of
the finer part of the Stourbridge clay, with a small propor;
tion of pipe clay.

The rings are made from two parts of Dutch black lead
pots powdered, and one part of pipe clay. I have made re-
peated trials of English black lead, in various states, as a
substitute for the Dutch black lead pots, but without finding
it to answer properly.

Should any difficulty appear in any part of my process, I
shall be happy in attending the committees, and performing
the whole operation before them, whenever they shall be
pleased to appoint, when the great simplicity and advantage
_ will appear evident.

I am, my Lords and Gentlemen,
Your most obedient and respectful Servant,
EDMUND TURRELL.
No. 40, Rawstorne-street, Goswell Road,
April 10th, 1806.

To the Mzmpers of the Socizry of Anis, &¢.
Certi-

978 ON ELECTRICAL CHARGES AND DISCHARGES.

Certificates from Messrs. J. Haynes and Son, Westmoreland
Buildings; John Kelly, Hooper-Street, Clerkenwell; John
Foster, Author Street, St.Luke’s; and William Foster, Author
Street, St. Luke’s, states, that they have been in the habit of
using Mr. Turrell’s muffies for upwards of twelve months,
that they are greatly superior to any they have hitherto been
able to procure; and that it is their opinion their durability
may be completely attributed to his improved method of
moulding them.

=e
VIL

Considerations on the State in which a Stratum of nonconduct-
ing Matter must be, when interposed between Two Surfaces
endued with opposite Electricities: by A. AVoGADRO, Cor-
responding Member of the Academy of Sciences at Turin*.

SECTION I.

Suite inf anions "LTuose learned natural philosophers, who have lately
conductor be- studied with so much success the mechanism of the forces,
ee that electricities of the same or opposite kinds exert on each
ficiently exa- other, either in conducting substances,.or through noncon-
mined, ductors, have not paid equal attention to the facts, that may
lead us to some knowledge of’ the state of the insulating
substance} through which these forces act; particularly when
it is interposed between two electricities of opposite kinds,
that mutually support each other by their attraction. Yet
it such facts exist, they might lead us to consequences of
great importance to the theory of electricity, In reality the
circumstances I have just mentioned, the interposition of an
insulating stratum between two bodies endued with opposite
electricities, is of great extent in electrical phenomena: it
not only takes place with respect to substances made to ape
proach each other expressly for this purpose, and in charg-

* Journal de Phisique, vol. LXIII, p. 450.

+ In this paper I employ the term énsulating as synonimous with what
is commonly called nonconducting, or electric per sé.

ing

ON ELECTRICAL CHARGES AND DISCHARGES. 279

ing the Leyden phial, or a plate of a glass, which in fact is Leyden phial.
nothing more than a method of bringing the two coatings

nearer together than could be done in the air: but it intro-

duces itself generally into all the electricity of conducting A general case,
substances, as is easy to be observed; for every electrified

body is surrounded with other bodies more or less distant, on

the surface of which, according to the established princi-

ples, the electricity of the former body can only occasion an

opposite electricity by acting through the intervening stra=

tum of air. We may truly say, therefore, that there is no

electricity but has opposite to it the contrary electricity, with

an intermediate insulating stratum.

On the other hand, were we once convinced of the insula- Fhectricity not
ting stratum in these circumstances being in a peculiar state, sale aes
distinguishing it from a simple medium through which the gravitation.
electric forces exert themselves, it is natural to suppose,
that a more attentive examination of this state would give
us some idea of the manner in which those forces exert
themselves, which the labours of philosophers have hitherte
only confirmed; but which, according to all appearance, are
not to be ascribed to an original property inherent in the
substances that exert them, as has been asserted with great
probability in respect to the Newtonian attraction of matter
in general. —

Now reflecting on certain facts, that Symmer, Cigna, Facts eae
Beccaria, Volta, and others have established by their expe- be Ha neat be
riments, it has seemed to me, that we might deduce from the noncon-
them some inferences relative to the state of the msulating pad
stratum in question. The object of the present paper is to
detail the ideas, which these facts have suggested to me.

Secr. II. The fundamental experiment*, which first Fundamental

* The facts adduced in this and the following section are not new;
neither indeed are the reflections accompanying them wholly my own,
JEpinus, Haiiy, Volta, and others, have already given them at least in
part, and in a form more or Jess resembling that in which I exhibit them;
but perhaps they have not paid them sufficient attention in general. I
have thought it necessary, to resume this subject in a somewhat more
extended way, as an introduction to the ideas that. constitute the princi-
pal object of this memoir, and which I begin to lay before the reader in
section IV.

presents

280 ON ELECTRICAL CHARGES AND DISCHARGES,

experiment presents itself in this branch of electrical science, is the fol-
when two non- ae : . : : :
conductors lowing. When two insulating bodies, or one insulating and
charged with one conducting body, the surfaces of which are endued with
ae opposite electricities, come to be applied to each other by
together, the their surfaces, the electricity of. both seems to disappear.
patiag diss We no longer find any sigus of it, or at least if any sign of
either kind of electricity remain, they may easily be deprived
But itis not of this surplus: but then if we endeavour to separate these
destroyed. 5 :
two bodies, we find, that they adhere together, which proves,
that all their electricity was not really destroyed; andif we
overcome this resistance, and actually separate them, we
shall find, that each of thess bodies again exhibits sigs of -
that kind of electricity, which it possessed before*they were _
brought together. These phenomena however are not to be
observed in all their simplicity, except with insulating bo-
dies of a texture sufficiently thin to be incapable of an elec-
tric charge; and such as have a kind of communication be-
tween their surfaces, as with two ribands for instance, or
two silk stockings, or one of these and a piece of insulated
tin foil. Tshall not here enter into the particulars of these
experiments, which may be seen in Priestley’s History of
Electricity, Mr. Symmer’s communications to the Royal
Society, Mr. Cigna’s paper in the 3d vol. of Miscellanies of
the Royal Society of Turin, &c.
Onlyaparticue Before I introduce this fact into the examination, that
lar case of an constitutes the principal object of this paper, it may not be
acknowledged : Sagi : i
generallaw. miss to show, that it is merely a consequence of the known
principles of electricity, a particular case of a law, the gene-
rality of which is at present acknowledged. ;
The We ear: It is known, that one kind of electricity is capable of be-
the interposed ing so much the more condensed on a surface in proportion
sei Ba to the proximity of another surface endued with the con-
epposite elec- trary electricity, the attraction between the two kinds of
aay electricity in this case surmounting with more advantage the
repulsive power, which opposes this condensation in each
kind of electricity. It js known Ikewise, that for this rea-
Leyden phiat. son the coatings of a Leyden phial cai acquiré mach
greater quantities of electricity than bodies of equal surfa-
ces electrified in the air; and it isa pract:cal truth long
known, and depending on the same principle, that the

phialg,

ON ELECTRICAL CHARGES AND DISCHARGES.

phials, panes of glass, &c., have so much the greater capa+
city for a charge, other circumstances being equal, in pro-
portion as their thickness is less.

This admitted, let us suppose, that the snrfaces of our
two ribands, endued with opposite electricities, are gradu-
ally brought nearer to each other, keeping them parallel.
The repulsive force of each of these two electricities will
render itself so much the more perceptible, and they will
have so much the less teadency to be conveyed away by the
surrounding bedies, as their distance is diminished ; because
the attraction between the two electricities will become so
much the greater: and when at length the surfaces are
brought into contact, the attraction having become as it
were infinite, these electricities will no longer tend to fly
off, but will remain as if they did not exist with respect to
other bodies, whatever intensity they had before, siuce this
intensity was limited, and the repulsion arising from it was
also limited.

Thig may be exhibited in another point of view. When
we charge a plate of glass, the electricity produced on the
interior face of the coating opposite that which is electrified
‘directly has no tendency to fly off, because it is perfectly re-
tained by the attraction of the electricity of the latter coat-
ing; an electricity which, according to the principles of
Coulomb and Haiiy, to produce this effect must be con-
ceived somewhat greater, than that which is produced on
the opposite face gf the plate, The electricity of the face
electrified directly is on the other hand perfectly retained by
that of the opposite face, with respect to the portion equal
to it: and it is only its excess that has a tendency to be dis-
sipated, and requires the resistance of the air to retain it.
Now Haiiy has already observed, that this excess, according
to the theory, must be so much the less, in proportion to the
thinness of the plate; and that it would be nothing, if the
plate were infinitely thin, or in other words nought. Nei-
ther of the two electricities then, that compose the charge,
would any longer tend to fly off; they would become insen-
sible, This is precisely the case of the electricities of our
¢vo mbands, considered as coatings of the stratum of air at

first

261

Case of two
electrified ri-
bards.

Charged plats
of glass.

982 ON ELECTRICAL CHARGES AND DISCHARGES

first interposed between them, and which becomes nought
by their contact. ,
aa There is nothing here at which we need be surprised, ex-
stroyed by the cept, that the two electricities are not destroyed by the con-
eontact, - —_ tact, where nothing appears to prevent their mutual attrac-
tion from exerting itself. But we may suppose, that this
attraction is sufficiently satisfied by the mere contact, that
this contact serves instead of actual communication, and
that it neutralizes the two electricities, as communication
itself would do; for it is sufficiently proved, that this does
not take place, and that the two electricities still belong to
the two faces separately, since they immediately manifest
themselves when the two surfaces are again separated so that
a fresh stratum of air is introduced between them. The
resistance we experience in this act of separation is like-
wise an effect of the two subsisting electricities, the mutual
attraction of which necessarily opposes a separation of the
surfaces, which carries with it that of the electricities.
MAY ae Hem It is easy to perceive however why we cannot observe these
posigerenn be- phenomena between two conducting bodies; for as the con-
N/a il con tact of the two surfaces can never take place accurately and
{ aud instantaneously at every point, the first point of contact
between two bodies of this kind is sufficient to destroy the
whole electricity of the two surfaces, which still retains its
intensity, and is not yet neutralized by contact. The same
thing would take place on the separation of these bodies,
even if we supposed them possessing this electricity, though
imperceptible, in the state of contact. The retention and
apparent reproduction of the electricities therefore cannot
take place, unless one of the two bodies at least is an insu
lator.
Asthe electri: Before I proceed farther I shall observe, that the total
ae berde. LOSS of intensity, which the electricities experience in the
stroyed, none contact in question, has led some to imagine, that the elec-
conductors _tricities really destroyed each other by communication: par-
eee ticularly as they could not conceive what should prevent this
@0 separation. eommunication from taking place: and in consequence they
were obliged to suppose, that insulating bodies had the sin-
cular property of resuming on separation the electricity they
‘had deposited on coming into contact; that they reclaimed
it

ON ELECTRICAL CHARGES AND DISCHARGES. 233

itas it were: and hence the name of claiming electricity
(eleetricitas vindex), which Beccaria gave the electricity
thus apparently reproduced. The adhesion of the two sur-
faces on their contact however had led others to presume,
that the electricity was merely latent, and not annihilated.

This question, which presented no clew to its elucidation, The electricity
and which was reduced almost to a dispute about words, or ee
to a different mode of viewing the same object, while the
phenomenon in consideration was examined separately,
solves itself now we perceive its connection with known prin-
ciples: for it is demonstrated a priori, that the electricity in
this case must lose its intensity, and become imperceptible,
though it is not really destroyed: We may express this

‘state by the term of quiescent electricity, or electricity at
rest.

Secr. III. Let us now pursue the inquiry. I have said, When the in-
that it is only with insulating substances of a thin texture (Crvonins nom
we can observe the phenomena of which I have spoken in thick the phe-
all their simplicity. It is easy to conceive with respect to DOMED? aPpese

3 : : Hs morecomplex.
compact bodies capable of being carged with electricity, as
for instance two plates of glass, that the dependance, which
the electricity of one of the faces has or may have on the
electricity of the face opposite to it, with which it forms or
may form the electric charge of the plate, must necessarily
render more complex the phenomena relative to the state of
rest, and to the revivification of the electricity of the faces,
that are brought into contact or separated. I shall not en- |
ter here into the details the subject would require. Though
several natural philosophers have already engaged in re-
searches of this kind, much remains to be done, toillustrate
it completely*. Nothing more, is necessary for my purpose
“i here,

*The first experiments on quiescent electricity, and its revivification in History of
compact bodies, were made by the Jesuits of Pekin, and communicated the experi-—
to the Academy of Petersburg in 1755. These gave occasion to a paper aan this
by Apinus in the 7th vol. of the New Transactions of that Academy.

Symmer treated the same subject in his fourth paper, read to the Royal
Society in 1759. Lastly Beccaria entered into it very largely in his book
entitled ‘“‘ Observationés atque Experimenta, quibus Electricitas vindex
Jate constituitur, and explicatur. Turin, 1769, Thereader may likewise

see

284

two plate
glass discharg-
ed asa single
ene.

ON ELECTRICAL CHARGES AND DISCHARGES.

here, than to relate the simplest case. Let us snppose, that,
after having charged two plates of glass, those faces are
brought into contact, which are charged with opposite elec-
tricities, bemg previously divested of their coating: and a
communication between their exterior coatings is then esta
blished; in other words, that the two plates thus joined are
discharged as if they were a single plate. The plates thus
joined will no longer give any sign of electricity, and the
two exterior electricities are destroyed by this communica~
tion, as if there were no ethers. As to the interior electri-
cities, it seems at the first view, that they must have been
annihilated at the same time by their mutual communica-
tion, the dependence of each on one of the electricities of
the exterior faces having ceased. But this is not the case:
these two electricities being m contact must merely neutra-
lise each other, according to the principles of quiescent elec-
tricities, by this contact, as soon as the anterior electricities,
having destroyed each other, cease to maintain them sepa-
rately, They become imperceptible in.consequence of this
neutralization only, and ought consequently to oppose each
other like those of the ribands mentioned above, when we
separate the plates again. And this is what experience in
fact demonstrates: for, if we attempt to separate the two
plates after having discharged them together, we find a re-
sistence as much superior to that displayed by insulating be-
dies of a thin texture under similar circumstances, as the
electricities that concurred to form the charge of the two
plates, and which are here couverted into quiescent electri-
cities to be revivified by separation, are superior to those that
could be imparted te the bodies ef a thin texture. And if
we overcome this resistance, and actually separate the two
plates, the two electricities of the interior faces will resume
their intensity, and their tendency to decompose the natu-
ral electric state of the surrounding bodies, and in particular
of the interior face of the coatings with which the exterior
surfaces of the two plates are covered: whence it follows
from the known principles, that the exterior faces of these

see what he says on the subject in his Electricisme artifiziale. The theory

Volta has given of his elcctrophorus and condenser likewise regards the

game subject, J shall have ogcasion to notice these hereafter. }
coating

,

ON ELECTRICAL CHARGES AND DISCHARGES. O84

coatings will give signs of an electricity of the same kind as
that of the interior face corresponding to each plate.

The phenomena exhibited by a compact, charged, insu- One of the un-
lating plate, one of the uncoated faces of which is brought ings Ss a
into contact with a conducting body, depend on the same pe
principles; but they would also require a minute detail to be contact with a
treated fully. To this class of phenomena belong the well conductor.
known effects of Volta’s electrophorus: and the same gen- The electro-
tleman has freed them to a certain degree from the compli- eae
cation respecting the charge of the insulating body, in his
semiconducting plate doubler, the effect of which appears to
me, to belong essentially to the phenomenon of quiescent
and revivified electricity, exhibited between a perfectly con-
ducting substance, and a substance of sufficient conducting
power to exhibit this phenomenon in its simplicity, as inca-
pable of being charged, and yet so bad a conductoras to af-
ferd a charge; while, as we have seen, it cannot take place
between two perfectly conducting bodies. But I cannot
here enter into the particulars, on which the theory of these
two instruments depend. I shall only say, that what Volta
himself, and since Haiiy, have said of it, appears to me es-
sentially to require the principles in question; but as thig
theory could not be completely developed by these gentle-
men, because they had no farther object than to explain the
effects of these instruments, they have not generalized it
sufficiently. In the course of this paper however, J shall
have occasion to touch on some points relating to this sub-
ject.

Sect. IV. Let us now return to the point in question, Charged non
and apply what has been said of the particular case of the CMductor
two plates, at which we had stopped, to the inquiry we had
in view respecting the state of a charged insulating stra-
tum, or that interposed between the opposite electricities,

. For this we want only one more fact,which is equally well es- Two plates
tablished. It is that if, after having charged the pair of plates ae 7 big.
joined together by their uncoated faces, as if they were a charged usa
single one, they be discharged in the usual way, and we after- rn hg
ward endeavour to separate the two plates, we observe the appearances,
phenomena of the revivification of the electricities, similar to ao when charg:
those obtained from two plates charged separately, afterward rts

joined

B86 ON ELECTRICAL-CHARGES AND DISCHARGES.

joined together by those faces that have opposite electricis
ties, and discharged in this state as we have already said.
his proves, that m the combination of two insulating
plates, thus forming but one body, each of the plates takes
its own charge; that it to say, there is formed on the lower
face of the upper plate an electricity opposite to that com-
municated to its upper face; that in like manner an electri-
city is formed on the upper face of the lower plate of the
same kind as that communicated to the upper plate; and
lastly on the lower surface of the lower plate an electricity
opposite to this: and thus the lastmentioned electricity does
not correspond directly to the opposite electricity of the up-=
per face of the upper plate, but depends on it only through
the medium of the intervening electricities of the two inte-
rior faces that are in contact. In fact, since the two plates
when separated after their discharge exhibit the same elec-
tricities, whether they be charged together or separately,
they must be in the same state after the discharge in both
cases: but this supposes likewise the same modification in
the charged state, since the discharge is made precisely in
the same manner, and with the same phenomena, in both
The samewith cases. Tt is unquestionably the same, when more than two
any number of plates are thus combined; each of them must undergo the
si same modification as if it had been charged separately, for
the number makes no difference here.
Onesolid plate Now as any compact plate may be conceived to be divided
therefore May nto as many strata as there are elementary molecules in its
be considered f i :
as a number of thiekness, all these strata must be considered, when the plate
inhnitely thin js charged, as having each its particular charge, so that the
rer face of one, which is charged with either kind of electricity,
is successively in contact with that of another, which is
charged with the opposite electricity: for as to the effect in
question it can make no difference, whether the strata be
simply in contact or adhere together, since in both cases
they form-but one continuous substance.
This the gene- The following is the idea therefore that facts have led us
1al principle. to form of every insulating stratum charged with electricity,
or, which comes to the same thing, taken between two op-
posite electricities: It ought to be conceived of as formed
of an infinite number of strata, all which, however thin they
are,

ON ELECTRICAL CHARGES AND DISCHARGES, 987

are, exhibit on their opposite surfaces electricities of oppo-
site kinds, as well as the assemblage resulting from them.

Coulomb and Haiy have been led to au analogous re- Cou'omb and
sult in their inquiries concerning magnetism, and the electri- mee Hoahed
city of the tourmaline, but they had not extended this idea to tism and the
every charged insulating stratum. It appears however, that seat
the modification of the heated tourmaline is not even a par- line,
ticular case of the general principle we have just admitted:
that this stone is not then simply a charged insulating body,
or a body interposed between two contrary electricities ; but
exhibits on its surface a modification of electricity, which is
perhaps more analogous to the state of a conducting body,
the natural electricity of which is decomposed. But this is
foreign to our purpose.

The addition that has just been made to our ideas respect- ana
ing electricity obliges us to a small modification of our no- ion afte
~ menclature likewise. Hitherto we have considered an elec-
tricity, which is on the surface that serves to limit two differ-
ent bodies, as belonging to the surface of either indiscrimi-
nately. Thus the electricity that is between the interior
surface of a coating, and the surface of a plate of glass te
which the coating is applied, might equally be called the
electricity of the coating, orthe electricity of the face of the
plate. Yet this electricity may have a different relation to
these two surfaces : oue may be that ofa body, through which
the electricity in question supports itself by its attraction for
another electricity of the opposite kind, and in the thickness
ef which it consequently occasions the peculiar modification
we have established: while the other of these surfaces may
be nothing but the mechanical support as it were of the same
electricity, or belong to a body, through which it does not
exert the particular action abovementioned., This is pre-
cisely the difference between the surface of a plate of glass
and that of its coating, or more generally between the sur-
face of the airthat surreunds an electrified conducting body
and the surface of that body: for we see clearly, that a con-
ducting body cannot have two electricities of a different
kind on its surface separated by its thickness alone. It is
improper therefore, to give the same name to these two dif-
ferent conditions. To distinguish them without deviating

more

Charged plate

What takes
place in the
discharge.

The extreme
electricities do
net destroy
each other by
the communi-
cation.

ON ELECTRICAL CHARGES AND DISCHARGES,

more than is necessary from established custom, I shall say,
that.a body is electrified, or endued or animated with electri-
city, when jhe electricity remains on this surface without oc-
casioning in the body to which it belongs the modification I
have spoken of, whéther the body be a conductor or an insu
lator; and with respect to the surface of the body that un-
dergoes this modification, I shall merely say, that the elec-
tricity is applied to it, which can only take place for an in-
sulating body. Thus in a charged plate of glass it is the
coatings that I consider as electrified; but the electricity of
the interior face of each coating is applied to the face it
coats. It may happen, that an electricity at the limits of
two bodies may affect these bodies equally with the modifi-
cation in question; and then this electricity may be consi-
dered at once with respect to each of these bodies as belong-
ing to their contiguous faces, or app'ied to them.

The name of electric charge will continue to indicate, as
it has hitherto done, the state of an msulating stratum inter-
posed between two electricities of opposite kinds, namely,
that to the opposite faces of which these electricities are ap-
plied, a state which is the subject of the present paper.

Sect. V. The facts, that have led us to form an idea of
the electrical charge, necessarily give us likewise more accu-
rate ideas of what passes in discharging a charged insulating
body. It is clear from what we have seen to take place, in
the two plates of glass united, that the discharge only obli-
ges the opposite electricities, which supported each other al-
ternately through each of the strata into which the insulating
body might be conceived to be divided, to become the elec-
tricilies of the faces of these strata, to which they were re-
spectively applied before the discharge, and to rest against
each other in pairs ina state of perfect repose; namely, that
of each face against that of the contiguous face of the next

stratum; so that, instead of an infinite number of charged

but very thin strata, the result is an infinite number of
pairs of electricities neutralized by contact.

What has been said in speaking of two plates might lead
us to suppose, that this transformation, this different arrange-

ment of electricities by pairs, was the consequence of the ~

extreme electricities of the whole stratum, that is te say, the
two

ON ELECTRICAL CHARGES AND DISCHARGES.

two electricities of the interior faces of its coatings, mutually
destroying each other by communication: but this is not
quite accurate. In fact experience teaches us, that there is
a revivification of electricity even between one of the faces of
a plate and its coating, when we come to take it off after
having successively charged and discharged it. Even the
fundamental property of the electrophorus of Volta is con-
nected with this phenomenon, if we consider the electricity
imprinted on the plate as occasioning a charge there, which
is true at least with respect to one part of this electricity ;
and the disk as a coating, by means of which we destroy
this charge in touching it before lifting it up. By this se«
paration the coating or disk is made to exhibit an electricity
of the opposite kind to that which it had when it was in con-
‘tact with the charged insulating plate; and on the contrary
the face of the plate exhibits the same kind of electricity, as
the coating had before the discharge, and which then conse=
quently was only applied to this face. It is clear from this,
that the discharge has not actually taken away the electri-
city, that was applied to this face; and occasioned the charge
of the plate; and that it has done nothing more than oblige
it, from electricity of the coating, which it was before, to
become electricity of the face of the insulating body, and in
this quality rest itself against another contrary electricity,
which was formed by the discharge of the interior surface of
the coating: in the same manner as that of the other strata,
which we conceive in the insulating body, rests after the dis
charge on the electricity that was applied to the face of the
contiguous stratum, and becomes the electricity of this face.
It is the same with the opposite coating. It is then by the
mutual decomposition of the natural electrical state,
which the two coatings are reduced by the transportation of
their preceding electricities to the faces of the insulating
plate, that the discharge is made: to form these two new
electricities, which become quiescent, and are necessary to
place in the same state all the other electricities of the insu-
lating stratum; these two electricities of opposite kinds,
which each of the two coatings acquires at the expense of
the natural state of the other; is the end of that transport-
ation of the fluid, which occasions the shock; and not to

VoL. XXI.—DeEc. 1808. U destroy

289

Electrophorus,.

In the dise

to charge the

electricity from
each side is
transferred in
part tothe
other, and thus
renders it quis
escent:

-

£90 ' UNEXPECTED PRODUCTION OF AMMONIA.

destroy the existing electricities by a communication be=
tween them.
and ae oc Thus, if the preceding considerations have already shown
Saat us, that the discharge does not really destroy all electricity
are increased in insulating bodies once charged, but merely changes per-
see ceptible electricities into quiescent, a result that may appear
singular, the last reflections that have been made Jed us to
a result still less expected, namely, that the discharge m-
creases the number of these electricities by two, to render
them all imperceptible.
The mode in Secr. VI. It remains now to inquire, how far these new
which electri- id £ el, : ‘ iach Hs - of th dif
city-acts may ideas of e ectrical charges and dise arges, or of the modifi-
be the subject cation assumed by an insulating stratum interposed between
of future in- ubayre : i age f
quiry. two electricities of opposite kinds, may facilitate our mves-
tigation of the mode in which electricity acts: but this in-
quiry, which demands farther preliminary reflections on
other points of electrical science, may form the subject of

future communications.

VII.

Account of an Experiment in which Potash calcined with
Charcoal took Fire on the Addition of Water, and Ammo-
niacal Gas was produced. Ina Letter from James Woop-
nousk, University of Philadelphia, &c.

To the Eprror of the PurtosopHicaL JOURNAL.

a SIR, Philadelphia, Sept. 15th, 1808.

Soot and pearl. Havine been engaged in ‘the analysis of soot, I ex-
ash exposed to ,osed half a pound of this substance in powder, mixed with

an intense 3 . ;

heat. two ounces of pearlash, im a covered crucible, to the intense
heat of an_air furnace, for two hours.

When cold When the mixture became cold, it was emptied upon

took freon a plate, and a small quantity of cold water poured upon
Aa it, when it immediately caught fire. Expecting there
Not hidrogen WA2 2 decomposition of water, I placed my nose over the
but ammonia- mixture, in order to smell the hidrogen gas, which I sup

posed

ADVANTAGES OF GAS LIGHTS, 291

posed would be thrown off, but was astonished to find a dis- cal gas evoly«
engagement of amioniacal gas. ig

The_experiment was repeated with common charcoal, with Charcoal gave
exactly the same result. re Sige haa

Azote Is one of the component parts of ammonia. Now, wrence cain ‘.
as this base is not contained in either potash, water, or char- the nitrogen?
coal, whence did it arise, to form the ammoniacal gas?

Is it one of the component parts of potash? or is this sub- Is it a compo-
stance a triple compound, formed of oxigen, azote, and the ae es of
peculiar metal, which Professor Davy has discovered ?

Nascent hidrogen sometimes combines with the azotic por- The ammonia
tion of atmospheric air, and forms ammoniacal gas; but °t from nas.

IM : : : h cent hidrogen
this is not the case in my experiment, for, if the fire of the combining
mixture of charcoal and potash be extinguished by water, with ihe nie

BS ee * : : trogen of the
and it is then immediately placed under a bell glass contain- atmosphere,
ing atmospheric air, the oxigenous part will be absorbed,
and the azotic air, will be left behind.

No carbonic acid will be formed.
I am, Sir,
Your humble servant,

JAMES WOODHOUSE,

Vill.

On the Advantages of employing Coal Gas for Lighting small
Manufactories, and other Purposes. In a Letter from
Mr. B. Cook.

To Mr. NICHOLSON,
SIR,

I Have taken the liberty, from reading in your Journal for Teaco
September, the paper of Mr.Murdock on the gas light, to ad- beneficial to
dress the few following remarks to you. The more the advan- ee ie
tage arising from the use of gas is clearly stated, the more ge- light clearly.
netally and simply it is explained, to induce manufacturers

and others to make use of it, 1 think the better; especially

now, through the present rupture with Russia and the other

U2 _ northern

292 ADVANTAGES OF GAS LIGNTS.

northern powers, the want of importation of tallow has in-
creased to a very considerable heignt the price of candles,
‘soap, &c. ‘The rise of price in candles has of course
been the occasion of an equal rise in oil, as lamps are sub-=
Bie ath aelay stituted in the place of candles.
in this coun- This country produces a vast quantity of coal, in almost
try: every part where it is properly sought for, and if the gas
light was generally introduced into the greatest part of the
large, the middling, and even the smaller sized manufacto-
ries, a natural consequence would be, that coal would be
and if the : clei : :
consumption Consumed in much greater quantities. It might raise the
raised the price price, but it certainly would be a stimulus to men of landed
a iin property, to seek for it, where to the present it has been sup-
@ greater sup- posed a stranger. It would therefore, if the demand was so
Ply. much the greater, be found I am sure in greater quantities
than at the present, as miners would be induced to eek it
évery where. In times like the present, when we are A great
measure hindered from exporting it, it would be an advan-
tage if we could consume it all; and in fact at all times, if
the whole of the coal produced in this country could be
consumed, it would supersede this anxiety for exportation,
hice cient us especially 1f it brought a little higher price.
more generally In your remarks on the paper, you seem to think, that,
used than at was the was used generally in lighting the streets, and add
oe Nit to it, if generally used in manufactories also, the great
quantities of coak produced would be so much more than
the demand for it, that it would sell much lower than the
present market price. This would eertainly be the case,
unless coak could be mtroduced into more general use than
it is at present. But from experience I find, that a fire
made of coak will last muth longer than one made of coal;
for, the gas being extracted, it loses that degree of inflam-
mation, which, at the time it blazes, consumes the coal very
k fast; especially if it is good coal, which contains a large
at least in . . :
stoves in shops quantity of gas. When I speak of coak used in the place
and warerooms. of coal as an advantage, it is in stoves in warehouses and
shops, where stoves are in more general use than fire-places,
These having a quick draught, the coal, especially as I said
before, if good, soon flares away; but if coak is used, that
inflammatory principle being taken away, it glows, casts out
a great

ADVANTAGES OF GAS LIGHTS.’ 293

a great heat, and lasts much longer. I may say two fires of Cook bums
coak will last longer than three made of coal, so that I de (eatin
think that coak, bought at its present price, is equally as
cheap, if not cheaper, than coal. Therefore manufactories It would put
would experience no difficulty from the increase of coak, as Ale
each manufacturer would burn his own coak: it would be hence an ad-
only the coak produced from lighting the streets, that would cen
be required to be sent to market, and that only in the win-
ter quarter; and if no coak was made at the coak works,
and in fact, the demand on those works would in a great
measure be at an end, they would be forced to bring their
coals ta market.
I do not think then the coak made would be so much above The coak
the demand, for it is only in large manufacturing towns, where poe pas
: pe : : ch exceed
coaks are used 1n quantities; and im those towns, if they use the demand,
the gas, they will make perhaps as much coak as they may
want on the spot; they will therefore save all the expense of
the carriage of the conk from the works where it is made.
‘Besides, were they to sell it, they could afford it much
lower on that account; for, when the coak is made at the
works, the gas is all lost, beside the expense attending the
making, and the carriage of it to market. It might there-
fore, if the streets were to be lighted by it, be afforded at a
lower price, if it was found that more was made than could
be used in the regular way, to people who would burn it in
their stoves. It would certainly make a reduction in the pros and therefore
fits calculated to arise by lighting the streets, if it was sold ee ge a
at a lower price; but this I do not think would be the case, ede ace
as the demand, especially in times of good trade, 1s always
preat.

From the tar I conceive a spirit might be made, as a ry, spirit
substitute for the tar spirit brought from Russia, &c., that might pei
would be of vast importance to a great number of manu- Rint that

facturers, [especially japanners, &c., that article having imported.
advanced from perhaps three shillings or three shillings and
sixpence to twenty shillings per gallon since the stoppage of
trade from the north. If this end could be attained, the tar
would always be a source of considerable profit, and make
us independant on any other country for a supply of that

article.
The

coef ADVANTAGES OF GAS LIGHTS.

aaa The general use of gas would give us several great advan
Hee ase off tages: first it would prevent the great demand for tallow ;
gas. and candles would never be so expensive as at the present:
secondly it would in part take the place of oil; and thirdly
it would render soap lower, as the fat used for candies, might
be employed for soap making, saying nothing about the
‘Wse of coal tar. possibility of making spirits from the tar. Besides, if this
could not be done, the tar is a very excellent coating for all
out-door work, such as gates, fencing, and paling; as well
as for boat builders and shipwrights, it being a certain pre-
servative from the worm or the rot in wood exposed to the
air, or lying in the water; by coating the articles once in twa
years well with it. It is infinitely better than the common
paint used now: besides if the thing was general, and such
quantities of tar were made as would be the case, I should
suppose government would recommend its use in the dock
yards in order to encourage its consumption in preference to
that imported; for it is without doubt superior both as a
preventive of decay, and a preservative from the worm in
ships’ bottoms. ‘
All these advantages we have within ourselves, in that ar-
ticle which abounds in such plenty all over this island—coal,
Utility of the I now proceed to state the benefit 1 have derived from the
cerioeang ne use of the gas in my small manufactory, in order that small
facturers. tradesmen may make a comparison themselves, and see what
an advantage they may derive from its use. Mr, Murdock’s
paper is on the great scale, therefore far above the calcula-
tion of the simple mechanic; and it is.to the great number
of these that the thing ought to be made clear. To thema
small saving of ten pounds per annum is of as great conse-
quence as to the wealthy their thousands.
Apparatus on My apparatus is simply a small cast iron pot of about
oP at ee eight gallons, with a cast iron cover, which I lute to it with
sand. Into this pot I put my coal. I pass the gas through
water into the gasometer, or reservoir, which holds about
four hundred gallons; and by means of old gun barrels con-
vey it all round my shops. Now from twenty or twenty-five
pounds of coal I make perhaps six hundred gallons.of gas;
for when my reservoir is full, we are forced to burn away the
overplus in waste, unless we have work to use it as it is made.

But

ADVANTAGES OF GAS LIGHTS. ‘ 95

But in general we go on making and using it, so that I can- Calculation of
not tell to fifty or one hundred gallons: and in fact a great the profit.
deal depends on the coal, some coals making much more than

others. These twenty-five pounds of coal put into the retort,

and say twenty-five pounds more to heat the retort, which is

more than it does take one time with another, but I am wil-

ling to say the utmost, are worth fourpence per day. Froin

this fourpence we burn eighteen or twenty lights during the

winter season. The candles we used were six to the pound,

which on an average one time with another would be about
twopence each, though now nearly twopence halfpenny. Say
eighteen candles at twopence each are three shillings a day,

or eighteen shillings a week ; and that each man burnt his

candle for twenty weeks only in the year, though for the

winter quarter he in general has burnt two instead of one;

making the annual amount eighteen pounds.

Besides, my yearly expense in oil and cotton for solder- yritity of the
ing was full £30, which is entirely saved, as I now do all gas for solder-
my soldering by the gas flame only. My trade is that of a is
manufacturer of toys, in metal and gold. Now in all but-
ton soldering, all the plated articles, in fact all trades in
which the blowpipe is used with oil and cotton, the gas
flame will be found much superior, both as to quickness, and
neatness in the work; for the flame is sharper, and is con-
stantly ready for use, while with oil and cotton the workman
is always forced to wait for his lamp getting up; that is,
until it is sufficiently on fire to do his work. Thus a great
quantity of oil is always burnt away useless; but with the
gas, the moment the stop cock is turned, the lamp is ready,
and not a moment is lost.

You see my weekly expenditure in coal does not exceed Expenditure
two shillings; and if I allow five shillings a week to a man, for gas.
to employ part of his time to attend and make the gas, the
expense will then be seven shillings. The yearly expense,
if I take it at the same the whole year (although for twenty-
five or thirty weeks in the year none will be required as
candles) will only amount to £18 4s. I have, I know, in
- the instance of candles, much underrated the expense, as
also in oil, I have also estimated the expense in coal, &c.,
quite high enough; and the coak I find equally as cheap to

burn

298

Advantageous
On a still smal-
ler scale.

The profit un-
derrated.

ADVANTAGES OF GAS LIGHTS.

burn in my small stoves in the shops as coal; so that I do
not overrate this, when I say £2 10s. for it. The expense
of putting up my apparatus was about £50; but not know-
ing the cheapest and readiest methods to go about it, it cost
me more than it ought by £15. I will say £40, for which
in my statement at the conclusion I shall allow interest.

If erected on a smaller scale, the saving to the manufac-
turer is equally as great; for the poor man, who lights only
six candles, or uses one lamp, if the apparatus is put up
in the cheapest way, will find it cost him only £10 or £12;
which he will nearly if not quite save the first year. And if
the pipes are made of old gun barrels, as mine are, and
once a year, or once in two years, are coated over with the
tar to keep them from rusting, they will last half a cen-
tury. The burst or waste barrels, that used to be sold for
old iron, would then produce a better price to the gun
makers; and the pipes would be better and more durable,
than if made of more shght materials.

You see I have reckoned the five shillings per week for
the man the whole year, as also the same expense for coal
for the whole year, of course that is reckoning more than I
ought by nearly a fourth; but where soldering with the
blowpipe is necessary, gas will be wanting, although in
smaller quantities, in summer as well as winter, and Tam
desirous of overrating the expense, rather than otherwise, for
fear of any accident in a retort being melted, &c.

Now I dothink, the more generally this is made known,
that the industrious tradesman may derive from it the benefit
he ought, the benefit nature has so bountifully supplied this
nation with, the better: especially when candles and oil are
risen to so great a price, which is a very great drawback on
his profits and industry.

If you can extract any thing from the above imperfect de-
scription, that may be of any use, and put it into a shape, so
as to make it worth inserting in your Journal, I should be
glad. You see what my object is: to show to the middling
man as well as the great one, that a considerable saving and
advantage may be derived from the use of gas in his manu-
factory. Ihave said nothing about the greater safety there
is in its use than in that of candles; there being no dauger

to

~_

ADVANTAGES OF GAS LIGHTS.

to be dreaded from snuffs and sparks: a circumstance from
which I should think the Insurance Offices would be great,
advocates for its introduction also.

I will also, if you think proper, send you a plain descrip- Drawing and
tion of a small apparatus sufficiently and easily explained, 4¢scription of

that shall enable any man to put it up himself; for the thing
is so simple, that with a few plain drawings and explanations
almost any man of common abilities may doit. It is often
the case, that things of great advantage and use to the com-.
munity at large are kept back and as secret as possible by

individuals, who have had the good fortune to derive much

advantage from them: butif any thing useful can be intro-

duced for the benefit of mankind, that man is deserving of

thanks, who uses the best means nature has bestowed upon

him to disseminate its usefulness aboad.

Dr. Cr.
Yearly expense in Twenty weeks at eigh-
coalsandman £18 4 teen shillings per week
Tpterest on Forty for candles -+...---£18

Pounds----+»- 2 O Oilandcottonforlamps 30 0
Profits per year.. 30 6 Coaks worth seeeesss 2 10

SS eee

$50 10 £50 10

{ reckon nothing for the tar, setting it against any little
loss or accidents,

Tam, Sir,
Your humble servant,
Caroline Sireet, B. COOK.
Birmingham, Nov. 22d, 1808.
aa
REPLY.

I Shall with great pleasure receive and attend to the draw-
ing and description offered by Mr. Cook, whose clear de-
scriptions of matters of fact possess a value, which needs not

the addition of my suffrage to recommend them,
W. N..

IX.

4

‘208 ON VOLCANIC SUBSTANCES.

TX.

Extract from a Letter to J. C. DELAMETHERIE, on Volcunie
Substances, by Lewis Corpirr, Mine Engineer*.

Work on vol- I Have again visited the mountains of Auvergne, and have

ce finished certain observations and experiments, which will
enable me to present the public with a work on different
volcanic productions. The following are some of their re-
sults.

Titanium in _— **_ All the ferruginous sands of volcanoes capable of be=
voleanic sands ing attracted by the magnet are composed of oxide of iron,
and oxide of titanium.

and mostlavas. <«* The major part of lavas contain a petcepable portion
of oxide of titanium.

Granitoid “© The porous or massive granitoid lavas of the extinct
favas. volcanoes in the exterior of France are composed of feld-
spar, pyroxene, and iitanized iron.” On comparing them
Summit of . with the green granitello which is found on the summit of
sc coal Meisner in Germany, and which Werner places in the first
rank of those rocks that he calls secondary greenstone, they
appear to be perfectly similar. It is no doubt difficult to
conceive, how all the authors who have written on the granie
tello of Meisner could deceive themselves respecting its
composition: and such a mistake is so much the more sur
prising as this rock has given rise to various commentaries.
It is certain however, that it is nut formed of feldspar and
amphibole, as has hitherto been supposed, but of feldspar,
pyroxene, and titanized iron, which are very different. This
discovery adds fresh weight to the opinion advanced by Mr.
Voigt and several German mineralogists respecting the
Probably vole Meisner. It is extremely probable, that the summit of this
rae. mountain is in reality a fragment of volcanic strata,

* Journal de Physique, vol. LXII, p. 235.

+ We mist except those sands however, the base of which is specular”

tron ore; but these are extremely rare.

Xe

ON VOLCANIC SUBSTANCES.

X.

Leiter to J. C. DELAMETHERIE on some Granatoid Lavas,
by J. P. D’AuBuisson*,

if Have read with much pleasure in your number for Sep-

299

Some grani-

tember last the letter of Mr. Cordier, in which this minerale toid lavas come

ogist communicates to you the principal results of his ob-

posed of feld-
Spar and horns

servations and experiments on volcanic products*. To his blende.

third assertion, ‘‘ the porous or massive granitoid lavas of
the extinct volcanoes in the interior of France are composed
of feldspar, pyroxene (augite), and titanized iron,” I can
add, ‘‘ some of the lavas too are composed of amphibole

and feldspar.”

Ihave in my possession a specimen of lava from Cantal, Lava from
which is composed of, 1st, amphibole in long crystals, very Cantal

black, perfectly laminar, and exhibiting in the most distinct
manner the two directions of the laminz, cutting each other
at an angle of about 124°, which, as is well known is the
distinguishing characteristic of the amphibole: dly, feld-
spar in crystals of a vitreous aspect, like that of almost all
voleanic products: 3dly, a blackish gray matter perforated
with numerous small pores. This matter predominates in
the mass; yet in some places the amphibole is more abune
dant. This lava is a true secondary yreenstone; that is to

a true seconds
ary green

say, one of those found in the secondary trapformation, and stone.

which are composed chiefly of amphibole’and feldspar.

If the crystals that constitute the lava of which I speak paces into «
diminished in size so as to be no longer distinguishable by basalt compoe

the eye, and the whole ultimately formed a homogeneous
smass, which certainly happens in various parts of the stream
from which the specimen I possess was broken off, the result
would be a compact black rock, a real basaltes, composed
only of the elements of amphibole and feldspar, the same
greenstone but in a compact state: it would be to it nearly
the same as compact limestone is to granular.

-* Journal de Physique, vol, LXIIJ, p. 385.

¢ See the preceding ayticle,
The

sed of its eles

mentary mole.
cule,

3500

Granitoid of
Meisner.

Augite former-
ly confounded
with amphi-
bole.

Common
stones too
much neglect-

EXAMINATION OF a CALCAREOUS STONE.

The examination of various greenstones of the basaltic
mountains of Germany, of the granitoid of mount Meisner
among others, had formerly led me to a similar conclusion,
and I perceive with satisfaction, that certain greenstones of
Cantal indicatea similar formation. This however does not
prove, that there are no basaltes composed of the elements of
feldspar and augite confusedly united, much in the same
manner as we see certain porphyries with base of petrosilex
are nothing but compact sienites, or formed of feldspar and
amphibole; while others are compact granites, or formed of
the elements of feldspar, quartz, and mica.

The author of the letter finds it difficult to conceive, how
all those, who have written on mount Meisner, should have
been deceived respecting its composition. I will show how
we may readily account for this. Formerly the augite was
considered merely as a variety of amphibole (hornblende).
Werner was the first, at least in Germany, who distinguished
these two substances, which in many respects resemble each
other; but he did not distinguish them till after he had
written on mount Meisner, and said, that the granitoid on
the summit of that mountain was composed of feldspar and
amphibole. Authors have since repeated this assertion, and
continued to give the name of amphibole to what is in reality
augite. Ihave pointed out a mistake of this kind some
years ago; and I have lately mentioned, that part of what
some persons, myself among others, had taken for amphi-
bole, in mount Meisner, was partly feldspar coloured green,
and partly augite; but I did not go so far as to assert, that
this rock contains no amphibole.

XI.

An Examination of a Stone of the Calcareous Species called
‘© Thunder Pick.” By Mr. J. Acton, of Ipswich. Come
municated by the Author.

"Tue great eagerness, with which newly discovered and
rare minerals have been sought after by men of science in
order to their analysis, has occasioned the more common ones

to

EXAMINATION OF A CALCAREOUS STONE. 301

to be in some measure neglected; so that it is not unusual

for persons, who understand the composition of the diamond

or other valuable gems, to walk in their fields, and pick up

many stones, the nature and use of which they are unac-

quainted with, though perhaps in a friable state composing
considerable part of the soil of which they are the proprie-

tors. And I believe in cases where the more common mine- Even those that
rals have formerly undergone examination, such is the pre- ae pica 3
sent improved state of chemistry, and the consequent greater should be exa-
number and purity of tests and reagents, that it will scarcely mbes
be deemed superfluous, to subject them to fresh investiga-

tion; particularly if it be done with an ardent view to inqui-

quiry, and with diligent care and attention to the results.

Influenced by these considerations, I have ventured upon Thunder pick
an analysis of a stone of the calcareous species, frequently “es¢tibed.
met with in this country, and called by the common people
thunder pick, from the supposition of its falling from the
clouds in storms of thunder and lightning. It occurs in
crystals weighing from 10 to 1000 grains, of a conic shape, Crystals.
with a cavity at. the base extending about a fourth part
down the centre of the crystal. Its colour varies from gray, Colour.
brown, brownish red, to almost black, semitransparent,

The nearer they approach to the red colour, the greater is

their transparency. I cannot find they abound in any par- Generally soli.
ticular place, but are generally discovered solitary by the “””
husbandmen when at plough, or turning up the earth by

ditching or otherwise. When scratched with a knife it has Smell.

a strong alliaceous or urinous smell. Its cross fracture is Fracture.
fibrous, with the strie diverging nearly as from a common

centre. Its longitudinal fracture is glittering, with the striz |? |

parallel. It is moderately hard, and of the specific gravity Spec. gravity.
of 2°663. .

a. When heated upon charcoal before the blow-pipe, its Infusible
colour disappears, but it is infusible. _ anes

6. With phosphate of soda it is difficultly soluble and Fusible with
fuses into an enamelled bead. eee a

ce. With borate of soda it dissolves more readily, and fuses with borax,
into a semitranslucid white globule.

d. With caustic soda I could only partially fuse it into a and partially. /
white enamel. eagnsog-

Exp.

302 EXAMINATION OF A CALCAREOUS STONE.

Action of heat Erp. 1. A. One hundred grains of thunder-pick in coarse

bi fragments exposed in a platina crucible two hours and a
half to a moderate heat lost only four grains, but after-
wards exposed to a much higher temperature for an hour
lost 42°90 grains.

B. One hundred grains in one piece exposed in a porce=
jain crucible two hours to nearly a white heat lost 45-90
grains.

A and B. The residue of these two operations, amount-
ing to 112-20 grains, were exposed in a porcelain crucible
for four hours more to an intense white heat. When the
crucible was taken out and examined, only 102 grains
could be collected, as the remainder had united to the cru- :
cible, but from its apparent quantity no loss of any conse-
quence could have been sustamed. The crucible as well as
its Wedgwood cover had suffered a commencement of fu-
sion, and they could not be separated without breaking.

Dissolved in Exp. 2. A. Wishing to ascertain nearly the quantity of

nitric acid. nitric acid requisite to dissolve a certain quantity of thunder
pick, I weighed 100 grains of it in fragments, and intro-
duced to it 100 grains of pure mitric acid of the specific
gravity 1°431, and added more acid by ten grains at a time,
till the whole was dissolved. Having thus found the quan-
tity of acid necessary to dissolve 100 grains of thunder-pick,
I placed it on the balance, and equipoised it on the other
scale; 100 grains of thunder-pick were then conveyed into
the acid, and the weight of the carbonic acid gas was found
to be 42°40 grains.

&nmuriatic. B. I repeated the above experiment, substituting a quan-

tity of muriatic acid of the specific gravity of 1°149 with

100 grains of thunder-pick, and nicely adjusting the ba-
lance as before, found the weight of the carbonic acid gas
given out to be 43 grains.

Oxide of iron C. The nitric solution (A) being now filtered became

& manganese. » early colourless, aud left on the filter the colouring matter
of the thunder-pick. I believe a little oxide of iron and
manganese, which, when dried, weighed 0°40 of a grain.

Carbonate of | D- The filtered solution being treated with carbonate of

lime, potash, carbonate of lime fell down, which when collected
and ignited in a crucible weighed 96 grains.

E.. To

i

EXAMINATION OF A CALCAREOUS STONE. 303

E. To the again filtered liquor was afterwards added
caustic ammonia, when no precipitation ensued; but on
treating again with carbonate of potash, it occasioned a
cloudiness, which fell down, and when collected and ig-
nited weighed 1°50 grains, which dissolved with effervescence
in nitric acid.

_Exp.3. A. To be still further assured of the above ex- Carbonic acia
periments being managed in nearly an accurate manner, [ 885 collected.
put 100 grains of thunder-pick into a small gas bottle, and
poured on a sufficient quantity of nitric acid to dissolve the |
whole. I collected the extricated gas with the mercurial
pneumatic apparatus in nicely graduated jars, amounting
to 91 cubic inches at the temperature 48° and pressure
29°88, which by the usual following calculation gave 92°63
eubic inches at the medium temperature of the air at 60°,
and barometric pressure 30 inches,

Rate of expansion for every degree of the thermometer, ac-
cording to Gay Lussac.

60 mean temp.

480)91°00(0°189 48 actual temp.
i 480 12 =—
——— 12 difference.
4300 2°268 —
3840
4600
A320
280
——s 91
2°26
30 meme 29°80 ee 93°26
29°80 *
746080
83034
18652

3]0)2779:1480

92°63 cubic inches at the corrected:
ems = Lem perature and pressure.

If

304

Medium esti-

mate of the

carbonic acid.
taken as follows;

EXAMINATION OF A CALCAREUUS STONE.

If the quantities of carbonic acid gas produced in the fore-
going experiments be added together, and the average

42°90 .

45°90 i Extricated by heat.

42°40 2 Extricated by nitric and mue-

43°00 riatic acids.
4)174:20

(ere meee a} ees

43°55 Average.

And if it be admitted, accerding to the late accurately
conducted experiments of Messrs. Allen and Pepys, that
100 cubic inches of carbonic acid gas weigh 47°26 grains,
then by the following calculation 43°55 grains will amount
to 92°14 cubic inches, which is within half a cubic inch of
the gas actually produced—

47°26 ——— 1 00 = 43°55

92°63 Gas collected.
100

Como ccees eno

A7‘20)435500(92°14 i Cubic inches by cal-

425384 ——
—''49 Dif.
10160 ——
9452
7080
4726

culation.

23540
18894

4646

pena ee meneageT)

The carbonic acid gas collected in the last experiment
being submitted to the test of limewater, by means of
Pepys’ Eudiometer, from 98 to 99 parts out of 100 were

absorbed.

The following therefore appears to be the result of the
abeve analysis of 100 grams of thunder-pick ;

Average

ae

ON GRAVITATION. be S05

s.

Average of experiments produced—

Carbonic acid gas++++-+++++43'55 ) forming 97°50 ers.
Lime ......... ee eee esse e 53°95 | carbonate of lime.
Oxides of manganese and iron °40
Water and loss --csescccecss 2°10

—

100°00

On adding to the filtered nitric solution of the second No aluming
experiment succinate of ammonia, as a test for alumine,
no cloudiness ensued. ,
Neither was any effect produced on the addition of pruse
state of potash for iron. |
Thad dissolved 200 grains of the thunder-pick in nitric
acid, in order to precipitate it, to say how far it would cor-
roberate the former statements, but being interrupted, I
unwarily added the alcali without previous filtering, and
afterwards a small portion of it ; however I proceeded in
collecting it, and the precipitate, after ignition, weighed
192-70 grains, which is certainly a nearer approximation
than I could have expected under the circumstances.

XII.

Remarks on a Review of Professor Vince’s Essay on Gravi-
tation. Ina Letter from the Author,

To Mr. NICHOLSON.
SIR,

I Shall esteem it a favour if you will insert the following Remarks on
remarks upon the Edinburgh Review (vol. XXV) of my ae eaghe i
Essay on Gravitation. Essay on Grae
The fluxion of the elasticity from the change of distance Vition.

% is no solution of the problem I proposed to answer, i. e.

** to find the effect of the fluid to impel a spherical body of

‘* infinite magnitude, towards the sun.” The reviewer has
ipvestivated a point, which has nothing to do with the pro-

posed inquiry; and so little was he acquainted with the

VoL. XX1,—DeEc. 1808. x subject

Ld

306

ON DIFFERENT SPECIES OF SUGAR.
subject, that he considers the accelerative and moving forces
of, a body as the same thing.
I am, Sir,
Your humble servant,

Cambridge, 24th Nov..1808. S. VINCE.

Some of the hypotheses which have been invented to ac-
count for gravitation are so fraught with absurdity, that it
was not thought necessary even to state them.

XIII.

\

An Essay on the Sugar of Grapes; by Professor Proust*.

Grapes contain Tue grape presents us with a sugar of a new species, the
males existence of which had hitherto been suspected only in con
i junction with those sweet and agreeable substances, that are
known to form the basis of the flavour of our fruits. Be-
fore I proceed to the examination of this product, the mode
of extracting it, its qualities, and the uses to which it may
be applied, it will be proper to lay down some general prin=
Order of the ciples respecting sugar. We must first distinguish its spe-
maeiy cies, take a view of the substances that usually accompany
it, and examine which of the latter it is essentially necessary
to separate from it, in order to apply it to our use, and
which may be suffered to remain without any sensible dimi-
nution of its qualities. This is the order I shall pursue
in my inquiry; and a concise view of these particulars I
trust will be sufficient, to enable us to judge whether the
species of sugar I announce have all the characters of the
genus ; and whether, while it possesses the qualities of be-
ing wholesome and agreeable to the = it be sufficiently
abundant to supply our waats.

On sugar and its species.
Theimmediate Nature, while she deposits in the various parts of the ve-
products of ve- ; ; :
getable structure those compounds, to which we give the

% Abridged from the Journal de Physique, vol. LXII], p, 257.
name

ON DIFFERENT SPECIES OF SUGAR. 307

fame of immediate products, frequently modifies them by getables vari-
slight shades, and varies each in so many different species. Be imodicns
Thus starch, gum, resin, oil, tannin, extractive, &c., while

they retain the principal characters of the genus, to which

they give their names, differ in certain respects, and thus

> give rise to the species which analysis-has discovered.

Sugar too has its species, and of these I purpose first to Sugar has its
speak, as the ideas with which they will furnish us are ne- Priivee dies
cessary to understand what is to be said respecting the sux im consistency,
gar of grapes. If we compare these species with respect to
hardness or consistency, we shall find a striking difference
in this respect. We see, that the product of the sugar cane
is dry, britile, and easily crystallized; while the driest
manna softens with a slight heat, and sticks to the finger
that presses it. We find too, that the syrupy product which
we call mucoso-saccarine is a third species, differing from
the former in uniting the viscosity of a mucilage to the pro-
perty of retaining a softness that no drying can destroy.

The honey, that bees collect from plants, and in which it Honey a com-

ae ; : ia : pound of two
is impossible not to recognise one of their immediate pro- species.
ducts, will give us an instance of two species combined.
That it frequently varies in consistence is well known; and
i#>has been long presumed, that it must contain a portion of
.. erystallizable sugar, which has even been affirmed, though
never proved: but as this conjecture has been confirmed by
the experiments I have lately made, I shali proceed to re-
late them.

The honey collected at Madrid on the heights of Flonda Yellow honey.
is yellow. It has the transparency and tenacity of a turpen-
tine to such a degree, that we may justly say it is to solid
sugar the same thing as’a balsam is to a resin. Alcohol
dissolves it almost entirely: a few particles of wax separate
from it, and it afterward deposits a smali portion of a vis-
cous substance, which is soluble in water, precipitable by
alcohol, aud without any particular taste. This is a true
gum. The white honeys, of which I shall soon speak, like-
wise contain a little.

The colour of the former is certainly owing to an extrac- Owes its co-

: Sagi : lee 5 Iour to extrace
tive principle, which cannot differ much from that of vege- y1..
tables, for the muriate of tin precipitates it in a yellowish

x2 lake

308 ON DIFFERENT SPECIES OF SUGAR.

lake, while with white honey this muriate scarcely gives any-
appearance. :
Does not cry: ‘The alcoholic solution of this honey left to evaporate
ee: spontaneously shows no disposition to afford crystals like
those [ shall soon mention, Perhaps it contains a little so-
lid sugar, which the liquid sugar retains so strongly as to
prevent its separation: but this does not prevent me from
considering this honey as wholly, or nearly so, one of the
two species of sugar, which I purpose to point-out in honeys
in general.
Thick honey | When a honey is very consistent and opake, we find that
SF oriann. in time it separates into two parts: one granular, crystalline,
and opake, that collects at the bottom of the vessel; while
the other, transparent and fluid without the addition of fo-
White honey reign moisture, remainsatthe top. We find too, that white
ae. ™°S' honeys are most liable to this kind of. separation, or that
they contain habitually more candy tiian the yellow.
White honey Presuming, that, though both the species contained in
aoe white honey were soluble in alcohol, that which is fluid
would be less so than the other. I added alcohol to some
white honey of the finest quality from the mountains of
Moya. The result of this operation, conducted with some
precautions which may easily be supposed, preduced thy
separation of a white powder, which subsisted spotaneously,
This powder, separated from the solution and slightly
washed with alcohol, ultimately afforded me a powdery su-
gar, which I left to dry in a moderate temperature. No~
thing more remained, but to purify it afresh, to make it into
A little wax a sirup, and dispose it to crystallize. Its solution in water
5 Sa acai occasioned the separation of some particles of wax; after
which, having boiled it down to the consistency of a thick
Crystallized. sirup, L set it by covered with a paper merely. In less than
two days, which I scarcely expected, it began to cover the
sides of the vessel with white points, whence I judged at
once, that I must not expect a crop of common sugar. In
fact on the fourth day the sirup was converted almost ene -
tirely into granular, hollow crusts, which had risea more
than an inch above its level. These T set by a few days to
drain, in order that its melasses might be separated as much

a

.

ON DIFFERENT SPECIES OF SUGAR. 309

as possible. The following are the qualities of this new
kind of sugar. —

It has a considerable resemblance to the head of a cauli- Qyatities of
flower, is perfectly white, and does not attract moisture. Its the crystals.
sweet, agreeable, and cool taste is less saccharine than that of
common sugar, has ne resemblance to the flavour of honey,
but it leaves on the tongue something [ can t describe of
farinaceous. Itis easy to conceive, that if it were employed
to sweeten any thing, more would be requisite than of honey
or common sugar.

If it be burned it diffuses the smell and usual fumes of
burned sugar. Alcohol dissolves it without any residuum,
and by evaporation it separates afresh into granular concre-
tions. Lastly nitric acid converts it readily into oxalic.

The melasses that drains from it is nothing but the second The auia
kind of honey, of which I shall speak, mixed with a little portion.
gum, which alcohol instantly demonstrates.

The second kind however must not be considered as per= This not free
fectly free from common honey, because the solubility of from solid
tne latter in common honey and in alcohol are two causes, ee
that prevent obtaining-an accurate separation of them, We
may succeed better by leaving a solution of honey in alcohol
to evaporate in the open air, for then the first crystallizes,
and leaves the second tolerably pure. The honey of the
mountains of Moya for instance, which is of a supériet
quality, affords in this way thirty-nine or forty per cent
of crystals, while by washing in alcohol we separate only
five or six and twenty.

The finid honey obtained in this manner is a sugar, that Quatites of the

_ retains a perfect transparency ; and however long we boil it, fluid portion.

its appearance will only be that of a thick turpentine. It at-
iracts moisture, and is the second part of the sugar, which
formed with the first the honey that has just been examined.
i have not examined their proportion in other sorts of
honey, for want of time; but till this inquiry is extended
to more, we may deduce from these facts some useful in-

ferences respecting the nature of sugar.
_ In the first place they show us, that the sugar collected
from flowers by the bees is of two species. They show us
too, that these species, united in honey, and compared with
the

Genera] pro-
perties.

os

310 ' OW DIFFERENT SPECIES OF SUGAR.

the sugar we derive from plants, resemble it likewise in two
points worthy of remark. The first consists in the two de-
grees of consistency; the one sclid, the other soft, which in
like manner divide all the vegetable sugars: the second in
the flavour, which is commonly more sweet or saccharine
in the fluid honeys and sugars, than in those which are
crystallizable.
Waldvcntsa ng The solid sugar of honey is not similar to that of the
tions not com- cane, either in flavour or crystallization : but in both these
mon sugar. —_ qualities it comes so near the sugar of the grape, that I
begin to doubt whether there be much difference between
Their separa- them. Unquestionably it would be an important advan-
tion difficult, tage to society, to be able to separate the two species of
sugar, thnt compose most kinds of honey, in order that
each might be employed exclusively for those purposes, to
which it is best adapted: and though at preseut I see no
hope of succeeding in this but by the mean of spirits of wine,
which would be far from economical, I cannot avoid thinke
but the grape . ;
may render us ing, that the result would be one step toward the emanci-

Te wen pation, for which a great part of Europe is anxious, if the
Q, e f

Indies, sugar of grapes did not offer itself, to hasten a period so do
sirable.
Mianaa. It has long been supposed, that the softness of manna,

Itssoftness not and the readiness with which it grows moist, were owing to
owing toex- an extractive matter; and that this matter, covering the
tractive. PNT ce ; :
qualities in which it resembles sugar, must be the cause of:
its laxative virtue. Ifhowever we examine its solution with
muriate of tin, we find but very little precipitate: and
alcohol dissolves manna completely, contrary to the opinion
of Lemeri. This solution, left exposed to the air, dries into a
porous mass composed of very slender crystalline filaments
and granular particles, which by its lightness resembles a
fine white agaric,
Iisa distince Manna thus refined does not approach the sugar of the
speciesofsu- cane: its moistness gnd faint taste are still the same, It is
par not in its nature therefore, to be any thing but what it has
always appeared to us, that is to say, a species of sugar, the
characteristics of which are softness, an unpleasant taste,
and the medicinal properties for which itis used. ‘To ascer-
tain whether manna likewise haye its two species, and be a
this

ON DIFFERENT SPECIES OF SUGAR.

this respect analoyous to honey and other sugars, it would
‘be necessary to analyse some fat mannas, of the purity of
which we could be certain ; but this is not at present in my
power.

311

A distinguishing character of manna is to form with nitric yields oxalic

acid the two acids afforded by gum, sugar of milk, mucilage
of linseed, &c.; while honey, which approaches manna in
Mlegree of consistency, does not.

Manna abounds in America, according to the report of
travellers. Herrera says: ‘ In the season there falls a large
quantity of a dew, which coagulates like sugar, and the use
of which is so wholesome, that they call it manna.” Is this
our manna? or is ita particular kind of sugar? Father
Picolo, one of the first spiritual conquerors of California,
hk .wise asserts, that it exudes from the shrubs abundantly
in April, May, and June. In Spain manna is so ‘plentiful,
that all Europe might be furnished with it, according to the
veport of two members of the Academy of Physic at Ma-
drid, who were directed to make the inquiry by the Mar-
quis of Ensenada.

There is at present no doubt, that sugar exists im a mul-
titude of vegetables, fruits, roots, and stalks, in the sap of
the palm, birch, maple, bamboo, maize, &c.: but we do
not yet know, whether that of the beet, from which Achard
has professed to manufacture it, and of other vegetables, in
which Margraff discovered it, be really of the same qua-
lity as that of the cane, or a different species; like those
that follow.

It does not appear for instance, that the sugar of the
maple is very similar to that of the cane, The juice of this
tree commonly affords five per cent of solid sugar: it is to
be presumed, that it has likewise its melasses, or sugar of
the second species. Travellers say, that it is three or four
times as long in dissolving as the sugar of the cane; that it
sweetens less; that the latter is preferred to it for chocolate ;
and that a portion of the latter is mixed with it for con-
fectionary. Hence it should seem, that the sugar of the
maple is not so agreeable as that of the cane. .

Weare told too, that in Egypt they extract from the pod
of the carob tree a kind of honey, which is much prized by

th,

and mucous
acids,

but honey does
not.

Abundant in
America,

and in Spain.

Sugar exists im
many plants,

Maple sugar.

Sugar from the
locust tree or
St. John’s
bread.

319 ON DIFFERENT SPECIES OF SUGAR,

the Arabs. I know already, that this sugar is not crystal-
lizable, but of the second species; and it contains an ex
tractive matter, which gives it a high colour, and spoils it
by a particular flavour, which assuredly would not be re-
Vinous and lished by the rudest Bedoween in Europe. Its wine much

ate resembles that of melasses, and where no other was to be
te) m < .
a see had, might be drunk without repugnance. It is very. in-

toxicating. The brandy produced from it I have made
kuown already.

Sugar<in vari- A sugar equally crystallizable with that of the cane, but

ous fruits. very different from it, exists in the gooseberry, the cherry,
and the apricot, the juice of all grapes, and uo doubt
many other fruits. Its crystals are pulverulent, and so
dificult to perceive, that I have not yet been able to observe
their shape. This produces the concretions, that are fo;nd
in raisins.

Sugar of figs, ° Figs appear to contain a great deal of crystallizable
sugar, since I am informed, that thick crusts of it separate
from them in the barrels in which they are kept dry.

of gooseber- The candy that forms among preserved gooseberries and

ries and cher- cherries equally belongs to these fruits, and not to the sugar

Ties, 5 ; :
of thecane. These concretions dissolved in alcohol always
resume the granular form, which is commonly found in
these preserves.

of the apple, The first species of sugar does not appear to be formed

re med- in the apple, quince, or medlar. Their juices afforded me
only the second loaded with gum and extractive colouriog

plum, peach, matter, It is probably the same with plums, peaches, &c.,

XC. for candy is scarcely ever found in their jellies or preserves.

Tn all these fruits however the sacharime product is con-
founded with gum, extractive matter, the malic, citric, and
tartarous acids, sulphate of lime, &c.

The two spe- These facts, which deserve a farther examination in the

cies variously yegeiable kingdom, contribute still more to confirm the

es aid existence of the solid and mucoso-saccharine species of sugar
which appear to divide our fruits in very various propor

tions.
The fluid spe- The fluid sugar, which had received the compound name
eics. of mucoso-saccharine, because it was considered as a mix-
ture of solid sugar and mucilages, was not well understood

by

ON DIFFERENT SPECIES OF SUGAR, 813

by any one before Deyeux: He perceived, that it was a

species of the genus, habitually fluid, and to be classed

among the immediate products. He judged too with rea-p,, pikcone
gon, that of the two species of sugar known it was the only that will fer-
one capable of fermenting by itself, while the other will dese a
not undergo this change unless disposed to it by some fer-

ment.

The labours of Duthrone too has so clearly confirmed oe separate
the existence of this product by the various facts he has cla
collected in his work, as to reuder it no longer disputable, object of the
that the only object of the sugar-makers must be, to sepa- “"8*" Maker.
rate the crystallizable sugar from the fluid: but I shall give
here the results of the analysis I have begun of the sugar-
canes.of Malaga.

Tn the juice of these, when fresh drawn, we find green Juice of Spa
fecula, gum, extract, malic acid, sulphate of lime, and ee
the two species of sugar. All these products, except as to mined.
their varieties, are the same as those met with in most
fruits.

A slice of the cane put into infusion of litmus reddens it Contains an
powerfully : yet its juice is not perceptibly acid to the taste, at
because the acid in it is enly in a very small quantity, and
the sugar covers it ; but in the juice boiled down it is plainly
perceivable. The following are the effects of reagents
on it.

The oxalic acid and barytes form a copious precipitate with sulphate of
it, which proves, that it contains sulphate of lime. Con-—”
centrated solution of platina throws down nothing so that no potash,
it contains no salt with base of potash.

Alcohol poured on the sirup of the cane separates from it gum,
insoluble filaments, which fall to the bottom of the vessel,
and are pure gum. Some time after the gum a small por-
tion of a white powder falls down, which is sulphate of lime.

This single product classes the juice of the cane with that
of most fruits.

The sirup, when freed from the gum and sulphate, forms extractive mat-
copious precipitates with the nitrates of lead and silver. With “™
limewater too a precipitate is formed, and the liquor turned
green. This imdicates the presence of extract, which mu-
riate of tin confirms by precipitating a whitish lake. The

same

S14

and malic
acid,

The use of re-
peatedly ad-
ding potash
and lime in
purifying su-
gar,

net ascertain-

ad.

Infusion of the
fresh cane

yields ammo-
nia.

Boiled down
to muscovado.

tts flavour.

The cane af-
fords half its
weight of juice.

ON DIFFERENT SPECIES OF SUGAR.

same sirup distilled with weak sulphuric acid affords no
signs of vinegar; the acid it coutaius therefore is not vo-
latile,

If this sirup be boiled with chalk, its acid is saturated ;
and from the filtered and concentrated juice alcoho! sepa-
rates malate of lime, but in so smalla quantity, that we
need not be surprised if Macquer and Darget, in the ex-
periments they made at Bercy near Paris, did not perceive
any acid in the juice of the cane. Duthrone, whew he said,
that the repeated employment of potash and lime in the
clarification of sugar must have for its object, to saturate
any thing but acids, was in the right. He even thinks, that
the alkalis combine with some remains of glutinous fecnla,
and thns lessen their too great solubility. Yet as it seems
difficult to conceive, according to our ideas of the proper-
ties of gluten, how it can remain dissolved in so large
quantity in juices void of acid, or deprived of it by the
first saturation, I dare not at present adopt this opinion,
because I do not see clearly what is the use of the alkalis in
the clarification of the juice of the sugar-cane.

The cane cut into thin slices gives out its soluble parts to
water. On concentrating this solution, a little before it
boils a greenish, feculent film separates, which does not
differ from that of gooseberries, grapes, &c., and affords abun-
dance of ammonia on distillation, Duthrone obtained the
same result.

If it be boiled down to the consistence of a thick sirup,
in fifteen or twenty days a congelation like honey will be
produced, sufficiently firm to remain fast in the vessel.
The taste of this muscovado sugar is pleasant: and it has
an aromatic flavour, which may be better recognized in me-
lasses, or still more in rum. The race of this liquor there-
fore isreally that of the cane: it is a product of the plant,
and not a precipitate formed in the preparation, or by any
of the changes to which the juice is exposed before it ar-
rives at the state of melasses.

Aceording to Duthrone, the cane commonly affords half
its weight of juice. This juice marks on Baumé’s areome-
ter from 5° to 14°, a difference depending on the ripeness,
and the influence of other causes, which occasion an increase

or

ON DIFFERENT SPECIES OF SUGAR. 315

er diminution of the products of the cane, as of other

piants. According to him 14° indicate twenty-five pounds

eleven ounces of sugar to a hundred pounds of juice;

and, as in the most favourable circumstances the cane does

not yield above half its weight of juice, a hundred pounds = ae
of the cane cannot produce more than thirteen of raw su- gar, or about
gar. If we speak of refined sugar, this product must be oe apt
reduced at least one third; sce raw sugar appears to con-

tain not much less than this proportion of melasses. The

proportion of dry to liquid sugar however is yet to be ascer=

tamed. No doubt it will vary according to the strength of

the plants, but it deserves to be inquired into, and I shall

attend to it when I resume my examination of the canes of

Malaga. To return to the muscovado, or raw sugar.

When we consider this honeylike mass, such as it is afford-- yryscovado
ed by the evaporation of the juice, that is with its sweet and Jong in use in
agreeable taste modified by the slight bitterness of its ex- ne er
tractive principle, we thay reasonably conjecture, that the
oriental nations, after they had discovered it, and piaced it
among the condiments adapted for seasoning their insipid
rice, would employ it for many centuries in this state,
as they did honey; and we may presume it was from the re-
semblance of honey to the raw sugar then in use, and not to
refined sugar, that some of the ancient naturalists termed
sugar ‘ another kind of honey, that is formed in reeds.’”

Honey itself, the only production that has any real resem-
pblance to muscovado, not being capable of any process of
refinement to improve its qualities, they would naturally
continue long of the opinion, that raw sugar was equally in-
susceptible of that degree of perfection, to which it has
been brought in modern times: and if we consider the
number of ages that elapsed, from the time when corn be-
gan to be the general food of man, to that in which he dis-
‘covered the art of making fermented bread, we shall find
this conjecture respecting raw sugar extremely probable.
Besides, it is proved by the historical researches of Du-
‘throne, that toward the end of the fourteenth century raw
sugar, without any farther purification, was an article of
trade in Egypt, Syria, Cyprus, &c.

But if the refinement of the honey of the cane have hap- part of the

' pily

316

SCIENTIFIC NEWS.

sugar is lost by pily enabled us to enjoy the use of sugar in all its purity,

refining.

Buchanan on
warming
buildings by
steam.

History.

Heads of the
subject.

we must confess, that we do not obtain this advantage with-
out sacrificing a part of the saccarine matter it contains;
for it 1s certain, that, if the melasses, which probably
amount to more thaa a third, could likewise be deprived of
the extractive matter concentrated in it by evaporation, as
well as by the several preparations it undergoes, with the
foreign matters introduced into it by the potash, lime, and
bullock’s blood, we should have im it a sirup, which, not-
withstanding the inconvenience of its fluidity, would be a
very useful substitute for sugar, in all cases where the lux-
ury of our tables does not render the latter. indispensible.
And it would have the farther advantage of sweetening in
smaller quantities: at least I may reasonably inter {his from
the melasses | have separated from raw sugar, the qualities
of which render it far superior to the melasses of our sugar
refiners, as it is not contaminated by any foreign mixture.

(To be conciuded in our next.)
ee
SCIENTIFIC NEWS.

An Essay on the Warming of Mills, and other Buildings, by
Steam. By Rosert Bucwanan, civil Engineer. Glasgow.

Iw this little but valuable pamphlet Mr. Buchanan has
collected the principal facts relative to the application of
steam for the purpose of communicating heat. ‘There are
two peints of view in which this subject may be considered,
safety andeconomy. In large manufactories of combusti-
ble articles the safety arising from the exclusion of coal fires
must be an obvious advantage. How far it may be econo-
mical must depend greatly on local circumstances.

The idea was suggested by Colonel Wm. Cook, m the
Philosophical Transactions for 1745, but it does not appear
to have been applied practically. Mr. Snodgrass first ap-
plied it to the warming of cotton works In 1798; see our
Journal, vol. XVI, p. 326: and his example was followed by
others.

Mr, B. arranges his subject under the following heads:

1. The proportionate size of boilers and quantity of fuel,
2. The

SCIENTIFC NEWS. 317

#. The proportion of steampipe required to heat a given
space. 3. The substance and colour of steampipes. 4.
Their direction and arrangement. 5. The modes of con-
necting them.
1. A cubic foot of boiler will heat about 2000 cubic feet Size of boilers
: : ES and quantity
of space in a cotton mill, where the temperature is in ge- of fuel,
neral from 70° to 80° of Fabrenheit. The boiler is supposed
to be of the shape commonly used for a steam engine, and
25 cubic feet to be equal to a horse’s power. Where the
boiler is separate, and not used for the joint purpose of
working an engine and warming a building, it should ‘be
considerably larger than in this proportion, to avoid the in-
equality of heat incident to a boiler working at its full capa~
city : 25 cubic feet of boiler require about 14lbs. of good
Newcastle coal per hour.
2. Every square foot of exterior surface of steampipe Proportion of
4 ; : ; pipe to spaces
will warm about 200 cubic feet of space in a cotton mill. A
small chapel has been warmed comfortably with half that
proportion. The safety valve in the boiler is supposed to
be loaded about 23 lbs. to the square inch. If the steam
were stronger, it would give more heat, but it would be
difficult to keep the joints of the pipe steam tight.

3. Cast iron pipes give out above twice as much heat as Materials of
copper, or tin, unless the tin be painted black. When the ? a
surfaces are equally dark, and equally rough, there is no
apparent difference. The thicker the pipe the more uniform
the temperature; but on account of the expense they are
generally not more than 2 or 3 of an inch thick.

4. The expansion of cast iron pipes may be estimated at Their arranges
zx of an inch for every 10 feet in length. Vertical pipes, ™°*
being equally heated all round, continue straight ; but hori-
zontal pipes bend, because the upper side is heated most,
and this endangers the joints. Vertical pipes too may be
used as pillars for supporting the floors. In the arrange- -
ment of the pipes two points require considerable attention.

First, conveniently to expel the air; and, secondly, to take
off the water proceeding from the condensation of the steam,
When the steam enters the pipes, it acts as a piston, driving
the air before it. This principle should be kept in view in
fixing on the place of the opening for the escape of the air.

After

318

Mode of con-
necting them.

SCIENTIFIC NEWS.

After the pipes are filled one or more openings will be nes
cessary, to allow a small portion of steam constantly to
escape, to keep up the heat of the pipes. If this be not
done, air will accumulate, and occupy the place of the
steam. It is best to make the condensed water run in the di-
rection of the steam, which will drivé the water before it in a
horizontal pipe, or even in one with a considerable acclivity.
Great care must be taken however, that no water lodges in
the pipes: for, the water remaining in the pipes after they
become cool keeps one part of them cold; the next time the
steam is let into the pipes the regular expansion is prevented,
some part of the pipe cracks, and a violent explosion takes
place, racking the joints to a considerable distance in every
direction. The common arrangement is to have a hori-
zontal pipe going off separately from each vertical pipes
This requires an opening for letting out the air at the end
of each horizontal pipe. A great improvement is first ta
earry the steam to the upper story in a vertical pipe, and
close under the ceiling in a horizontal one neasly to the op-
posite end of the building; thence in a vertical pipe to the
story beneath, and again horizontally under the cieling;
and thus from story to story till it comes to the bottom ;
where the condensed water may be allowed to run off by an
inverted siphon, which will allow the water to escape,
while its pressure confines the steam. The air may be
allowed to escape by a stopcock at the same place.

5. When the joints are formed by bolted flanches, these.
are liable to be broken from inequality of expansion,
or to leak at the bolt-holes. Spigot and faucet joints
do very well in some cases, but sometimes the faucets burst
from the greater expansion of the spigots. If the ends ef
both pipes be included in thimbles, though these are equally
liable to break, the expense is trifling compared with that
of awhole pipe. Fer branch pipes the joinings should be
made. by sadiles and hoops embracing the main pipe.
Where there is much silk of unequal expansion, the joimts
should be secured by a soft stuffing of hemp, or cotton, and
tallow; but inmost cases they may be made with ironi ce-
ment, composed of ion borings 40lbs, sal ammoniac 1b,
sulphur 2!b, well mixed together and beaten like putty.

The

The following is a Tabular View of the Effects of Steam in warming different Buildings.

eee

Cubic feet of

Temppera-
Substancce of Cubie feet of Space warm- | space warm | tures, de-
which the steam- | space in Cubic feet in | ed by 1 cubic _ ed by 1 su- grees of
Buildings. pipes are made. building. boiler. foot of boil- | perficial foot | Fahren-
ehy of steam- heit in
| pipe. winter,
Messrs. H, Houldsworth and Co. Anders- - { ee Sei | |
HOMGMIAS VT, 6} 5 sa voc sie uwsne sees Cast Iron, | lbs Maal Midas abe icc ok iv
Linwo6d, Ditto, .00.ccc.2cceceeeveeerey Cast Iron, 300000 120 | 2500 168
Messrs. Kennedy and Watts, Johnston, -- Cast Iron, 289000 160 1180 160
: Tin-plate not |
eeeeerteeeeeseeseseeeeoneoeteee8e ° 9
Catrine, ; painted, ee et | 200
oe Houldsworth’s Mill, aa Cast Iron, mikes ae 195 |
cnes er, Beseesee speeeet seus Cees ene8
Chapel of Port-Glasgow, .-.. +++. seeee- Cast Iron, | oe 6000 ~ i
Part of Adelphi Cotton Works, «+ e+ ees Cast Iron, [Sees
Tambouring Mill at Anderston, +... +... Cast Iron, | -——— —- 240
dee aay Hing and Sons, eg ‘ Cast Iron, [3 244583 | 12 | 1303 200

METEOROLOGICAL JOURNAL
For NOVEMBER 1808,

Kept by ROBERT BANCKS, Mathematical Instrument Maker,
in the Stranp, Lonpon,

| THER MOMETER.| aie | Heteee
OCT Hb | ea tO
— a v v 1 ‘
Day of} | ai | ee| 2 | 9A. M. | Night. Day.
alae ta
26 | 48 44. | 5Q | 42 29°25 | Rain Rain
97 |44/44150) 44] 29°42 Fair Ditto
28 44) 45 | 50 | 43 29°39 Ditto Ditto
20 | 441/44149)42) 29°66 Cloudy Ditto
30 | 46 | 47. | AS-+-42--"30°03 Ditto Ditto
31 | 44/44] 60/44) 30°34 | Fair Cloudy
NOV.
1 | 48/47 |50|46} 30°26 Ditto Ditto
2 |48|48]51)46} 30715 | Cloudy Ditte
3 47 | 47 | 50} 42 30°04 |. Ditto Ditto
4 44.442 | 47 | 38 30°21 Rain Fair
5 40 | 37 | 41 | 32 29°90 Fair Ditto
6 | 34136 }42k38} 29°88 Ditto Ditto
vs 42} 43 | 43 | 42 29°70 Cloudy Ditto
8 {46/48 150/45 | 29°65 Rain Rain.
Q9 | 47|50| 52/50} 29°56 Cloudy Ditto
10 48 | 48 | 52) 48 29°74 Ditto Fair
11 46} 45 | 481 38 29°84 Fair Rain
12 42) 41 |44]}40] 30°10 Cloudy Fair _
13 40138 | 41 | 32 30°11 Ditto Ditto '
14 | 34137 |38| 34] 30°11 Fair Ditto |
15 40,47 |49 | 42 29°98 Cloudy* Ditto
16 |50|51/}54}49| 29°61 | Dittot Ditto :
17. | 50} 51 }51}46!] 29:97 Raint Rain |
.18 46 | 43 | 48 | 33 28:80 Ditto § Ditto |
19 | 34] 38 | 40) 3 29 31 Cloudy Ditto z,
20 {| 40] 46 | 50 | 45 29°73 Rain -| Ditto
91 |50|46154/40} 29-76 } Fair Fair
22 1411/41 /52)46| 30718 Ditto — Rain 4
23 47 | 50 | 52 46 30°12 Rain Cloudy 4
94 146/45 150144 | 30:19 | Ditto Ditto |
95 |48151/52|46 |) 30°00 | Fair Ditto |
* 11 P.M. Rain and high wind. § Rain and fall of snow. |
+ Ditto ditto. || Preceded by heavy mist,

I Ditto ditto,

A

JOURNAL

OF

NATURAL PHILOSOPHY, CHEMISTRY,

AND

ro

THE ARTS.

SUPPLEMENT TO VOL. XX1.

ARTICLE I.

Essay on the Composition of Alcohol and of Sulphuric Ether.
By TuHEopore DE SAUSSURE.

(Concluded from p. 273.)
Decomposition of Sulphuric Ether.

Sect. VI. Preparation of the Sulphuric Ether employed
in my Experiments. Considerations on the Analysis of
this Fluid.

A HUNDRED parts of sulphuric acid by weight, mixed Preparation of
with a hundred parts of spirit of wine of the shops, the ™¢ ‘the
“specific gravity of which was 0-842 at 16° of Reaumur

[68° F;], afforded me by distillation through a worm 53

_parts of ether not rectified, the specific gravity of which ~

was 0-797.

This ethereous liquor, after mixing it with an alcoholic Rectified,
solution of potash, was distilled nearly to half at a tem-
perature of 35° KR. [11° Fu]. “The ether, freed from
the sulphurous acid, oil, anda part of the alcohol which
were united with it, was of the specific gravity of 740° at
16° R. [638° F.]. This is the rectified ether of the shops.

Vor. XXI.—Suprrement. Y The

322

Washed.

One third
drawn off.

More might
have been ob-
tainede

Results of
burning ina
jamp not accu-
rate.

Its detonation

gives more spe-
cific results than
that of alcohol.

its decomposi-
tion in a red
hot tube not
quite so accu-
Fates

COMPOSITION OF SULPHURIC ETHER.

The ether obtained by this operation was mixed with twice
its weight of water *, to separate still more alcohol from
it: and the ether, after it was decanted, was found to be
reduced by this washing to the specific gravity of 0-726.

This last product subjected to distillation, and only a
third of it drawn off, yielded an ether of the specific gra-
vity of 0-717 at 16° R. [68° F.]. This was the ether I
employed in my experiments.

It is unnecessary to observe, that by repeatedly rectify-
ing, and washing the residuums of the preceding rectifica-
tions, four or five times as much ether of the specific gra-
vity of 0-717 might be obtained, as by confining ourselves
to the first result mentioned above.

It has been seen, that the results of the stow combustion
of alcohol in a lamp in a close vesscl were deficient in pre»
cision. Those I obtained by the slow combustion of ether
were still more so, and therefore I shall not detail them.

The analysis of ether made by detonating its elastic va-
pour appeared to me sufficiently accurate to determine the
proportions of carbon, oxigen, and hidrogen. It is capa-
ble of giving more precise results than those obtained from
alcohol by this process. The alcoholic vapour is so light,
that its specific gravity is difficult to be ascertained. A very
slight errour in determining it makes great differences in the
results of the analysis. The gaseous vapour of ether is
much heavier; all the results are more striking; and small
errours here are less important.

The decomposition of ether by an incandescent porcelain
tube afforded meless precise results than the preceding ope-
ration, and much less accurate than those obtained from al-
cohol by the same means, because the ether in this process
yields thirty times as much oil, with respect to the compo-
sition of which I could only form conjectures. I will re-
late the particulars of this process however; as they will
serve to confirm the analysis of ether by the rapid combus-
tion of its vapour.

* The efficacy of this method has been demonstrated by the

experiments of Gay Lussac, given in Berthollet’s Chemical Statics,
vol, I.

SEct.

COMPOSITION OF SULPHURIC ITHER. 323

Sect. VII. Decomposition of Ether by an incandescent
Porcelain Tube.

Through a porcelain tube glazed within and heated red 1103 grains of
hot I passed 1103 grains of ether. I did not apply fire di- eae en
rectly to the retort, from which the ether was distilled, for hot porcelain
the vicinity of the furnace that heated the tube raised it to one
27° R. [92-79 F.], and this temperature was sufficient to
distil over the whole of the ether in the space of fourteen
hours.

The apparatus for this experiment was in all respects si- as the alcohol
mailar to that employed for the analysis of alcohol, and de. ant
scribed in Sect. V.. The porcelain tube was equal in size,
and exposed to the same degree of heat in the same furnace.

The ether was entirely decomposed: at least no smell of was entirely de-
" ether was perceptible in the vessels, that received the pro- eee
ducts of the operation. It yiclded me,

1, In the middle of the porcelain tube 5 grains of char- chareoal 5%
on which separated in the form of a thin Jeaf or scroll, 2%

This charcoal, being incinerated in a platina crucible, left
no ponderable quantity of ashes.

2, In the glass worm and the upper half of the receiver volatile oif
about three grains of a very inflammable essential oil, cry 3 8'0s,
stallized in shining scales, transparent, and smelling of ben-
goin. Most of these crystals were contaminated by a brown
empyreumatic oil, which they left behind after evaporating
in the common temperature of the air.

3, In the end of the porcelain tube that projected be- another oil 43
yond the farnace, in the worm, and in the receiver, where 8"
it was more abundant, 43 grains of an oil nearly black,
partly fluid, and partly of the consistence of honey. This
had a smell of benzoin mixed with an empyreuma; was
soluble in alcohol, and insoluble in water ; acrid, and, the
lips being touched with it, it gave pain, and caused suppu-
ration. When spread upon paper it dried, and, viewed
through a microscope, exhibited small yellow crystals,
which were not volatile like the preceding in the common
temperature of the atmosphere.

4, Adrop of water, weighing about three grains, found water 2 grains,
in the worm. It was colourless, smelt of benzoin, emitted

w2 vapours

324 COMPOSITION OF SULPHURIC ETHER.

vapours at the approach of muriatic acid, produced no
perceptible’ change in the infusion of litmus, or if it had
any effect it was reddening it. There was no water in the
receiver. ;
osicarburetted 5, Lastly, 3541 cubic inches of oxicarburetted hidro-
hidrogen 948 gen gas, at 27 inches 3 lines of the barometer, and 16° R.
ey [68° F.]. In this there was no mixture of carbonic acid
andathick §a@S3 but there came over with it into the receivers a thick
yellow smoke. yellow smoke, witha strong smell of benzoin and empy-
reuma. ‘This vapour was partly lost in the water of the
trough, on the top of which ag insoluble pellicle was found
floating, after it had stood a few days. When I detonated
this inflammable gas immediately after it was formed, and
while the vapour was suspended in it, it produced more car-
bonic acid gas, than when it was condensed. Every thing
therefore indicates, that this smoke was the vapour of oil.
The easweigh- The gas was not weighed and, analysed till twenty-four
Gea ana- hours after its extrication, and the complete disappearance
of the vapour. ‘That which was formed in the first periods
of the distillation was lighter, and contained less carbon,
than what was produced toward the end, though the heat
of the porcelain tube did not vary. On taking a mean be-
tween three portions of this gas weighed at the beginning,
middle, and end of the process, I found, that 3541 cubic
inches weighed 948 grains *.

Weight and * At 28 inches of the barometer, and 10° of the thermometer

composition of [54 5% F’.}, 1000 cubic inches of oxicarburetted hidrogen gas weigh

oxicarburetted 285 grains. That obtained from a similar distillation by the Dutch

hidrogen vary chemists weighed under the same circumstances 326 grains. That

from several i eae A

circumstances, Which Mr. Cruickshanks produced weighed 297 grains. Accord-
ing to this author, 100 cubic inches of this gas consume 176 of ox-
igen gas in forming 108 of carbonic acid gas. Nothing is more
variable than the weight and composition of this gas according to
the degree of’ fire, the diameter of the incandescent tube, its incli-
nation in the furnace, and the period of the experiment, at which
the gas is collected. I conceive, if this gentleman had weighed
and analysed it at every period of its developement, he would have
found in it less carbon. I speak here of the quantity of carbonic
acid gas produced by the cembustion of the inflammable gas, and
not of the absolute quantity of carbon he ascribes to it: this ap-
peafs less than mine, because he reckons much less carbon in the
carbonic acid,

The

COMPOSITION OF SULPHURIC ETHER.

The immediate products of the decomposition of 1103

grains of ether then are,
Grs.
Oxicarburetted hidrogen gas_ - - - 948
Charcoal a a # i 2 a 5°25
Oil, in part volatile - os - - 46
Water - - - = - - 3
1002°25

Loss owing to the oily smoke carried off
by the gas = = = - - 100°75

ee re

1103.

On analysing the gas in all the receivers by Volta’s eudi-
ometer, and taking a mean of the several analyses, I found,
that 100 parts by measure of this oxicarburetted hidrogen
gas consumed for their combustion 145 parts of oxigen gas,
forming with them water, and 88 parts of carbonic acid gas.

As to nitrogen gas, I found no more after the combus-
tion, than I had added with the oxigen gas which produced
it. Indeed most of my eudiometrical analyses indicated,
that the nitrogen gas introduced previous to the combustion
had undergone a smat! diminution in consequence of the de-
tonation*. The drop of water found in the worm adapted
to the incandescent tube exhibited signs of ammoniacal va-
pour on the approach of muriatic acid: but this test is often
illusory; and besides, as it is impossible for me to affirm,
that my ether contained no alcohol, the existence of nitro-
gen in ether must remain undecided.

325

Immediate pro- .
ducts of. the
ether,

The gas ana-
lysed.

On applying the calculation adopted in § V for the ana- Its composition

lysis of the oxicarburetted hidrogen gas of alcohol to the

* This condensation of nitrogen, according to the experiments, Nitrogen con-
of Humboldt and Gay Lussac, does not take place in the detona-.densed in some

tion of pure hidrogen gas with atmospheric air. In our operations
the circumstances differ, because the hidrogen is more condensed
in the oxicarburetted hidrogen gas of ether, than it is in pure hi-
drogen gas. "This diminution of nitrogen did not appear in the
combustion of the inflammable gas of alcohol, either because this
already contained nitrogen, or because the hidrogen is less con-
densed in the oxicarburetted hidrogen of alcohol than in the oxi-
carburetted: hidrogen. gas of ether, and even than in pure hidrogen

Gas,

results

circumstances,
‘not in others.

326

Ether contains
more carbon
and hidrogen,

COMPCSITION OF SULPHURIC ETHER,

results Wwe have just obtained from the detonation of the
oxicarburetted hidrogen gas of ether, we find, that 100
parts by weight of the latter contain,

Carbon - - - 56°12

Hidrogen - - - 17-43

Oxigen - = - 26°45
100.

The analysis of this gas compared with that of alcohol
is sufficient to give us some idea of the composition of ether,

but less oxigen, and show us, that this liquor contains in an equal weight

thansalcohol,

Vapour of

more carbon and hidrogen, but less oxigen, than alcohol:
for this oxicarburetted hidrogen gas alone constitutes more
than three fourths of the weight of the ether I decomposed.
The other fourth, which I pass by, is almost wholly oil, in
part fixed, in part volatile, which must have some similarity
of composition with theether. But as oil, according to the
analysis of Lavoisigr, contains scarcely any thing but car-
bon and hidrogen, it follows, that, in referring the com-
position of ether to the proportions of the elements of the
gas I have just analysed, we have too little hidrogen and
carbon, and too much oxigen. This will be confirmed by
the following process, which gives more precise results.

Secr. VUTI. Analysis of Ether by the Detonation of tts
Elastic Vapour.

For the preparation of the oxigen gas dilated by the va.

ether detonated pour of cther, and the estimation of the weight of this va~

with oxigen
gas,

Fxpansion of
the vapour.

pour, I adopted the same processes as those I applied to
the vapour of alcohol, § Lif. I think it useless therefore
to repeat-them; but I shall give one example of their re-
sults, the barometer being at 27 inches, and the thermome.
ter at 18° [72°5° F.]. Of five experiments made in a si-
milar way this appeared to me the most accurate, though
their differences were slight.

The elastic force of my ether, or the depression of the
column of mercury by a drop of this fluid introduced into
its vacuum, was 16 inches 9 lines. On applying to this re-
f » we find, that a volume of

sult the formula of Dalton

air

COMPOSITION OF SULPHURIC ETHER.

air equal to unity, into which the ether is introduced, will
eccupy, in consequence of the expansion of the ethereal
vapour, a space equal to 26341. I obtained: the same re-
sult by passing a drop of ether into a receiver full of air
over mercury, and measuring this air both before and after
the dilatation.

A thousand inches of atmospheric air dilated by the va-
pour of ether contained therefore 379-63 cubic inches of
pure atmospheric air, which weighed 161-9 grains.

327

I found by a direct experiment, that 1000 cubic inches 1000 cubic

of atmospheric air dilated by the vapour of ether weighe
816°37 grains. Consequently 1000 cubic inches of pure
ethereal vapour weigh in atmospheric air 816°37—161:9=
654°47 grains, according to the principle, that elastic va-
pour has the same weight in the air and in vacuo. (See
note at the end of this paper.)

d inches weigh
65447 grains.

~~

Oxigen gas dilated as much as it can be in the common Oxigen gas di-

: Bip aa lated as much
temperature by the vapour of ether will not take fire by the a5 posible wiih

electric spark. [he reason is, the vapour of ether is too vapour of ether

abundant, or, in other words, the oxigen gas too muc

ho of alcohol is
not fired by

rarefied. Alcoholized oxigen gas likewise does not take electricity.

fire, but from an opposite cause, the alcoholic vapour be-
ing too much rarefied; for, on adding pure oxigen gas to
the alcoholized oxigen, the vapour does not take fire, be-
cause it is still more rarified; but if pure oxigen gas be
added to the etherised oxigen, the vapour inflames.

I mixed over mercury 100 parts by measure of etherised Vapour of ether

oxigen gas with 504 parts of oxigen gas, and detonated |

fired with a
arge proportion

them by the electric spark. The explosion -burst the eudi- of oxigen.

ometers, which were not very thick. The 604 parts of
aeriform fluid, which before the detonation contained
541-96 parts of oxigen gas, were reduced by their combus-
tion to 344-31 parts, in which a second eudiometrical ana-
lysis showed there were 230-51 parts of carbonic acid gas,
and 113-8 of oxigen gas. The residue of the first operation
contained a dew, which appeared to be aqueous, and was
void of smell.

One hundred parts by measure of vapour of ether there. Produce of

fore consume 428°15 parts of oxigen gas*, leaving asa
residuum

65:447 grains of
vapour of ether.

. * Jf with etherised oxigen gas we mix 4 less quantity of oxigen Soot appears in
: \ gas some ‘cases.

ye

328

Carbon.
~ Hidrogen.

Water.

Its component

ers.

General results.

COMPOSITION OF SULPHURIC ETHER.

residuum water, and 230-51 parts of carbonic acid gar,

Hence we must conclude, that the oxigen gas has burned

395-28 parts of hidrogen gas contained in the ether.
Adinitting the numbers I have given to represent cubic

inches, and substituting for these the corresponding weights,

the barometer being at 27 inches, and the thermometer at
18° [72:5 F.], we find, that 100 cubic inches of ethereal
vapour weigh 65-447 grains, and contain,

1, The carbon of 230-51 cubic inches of carbonic acid
gas, or 38°64 grains of carbon.

2, Hidrogen gas 395-28 cubic inches, weighing 12°62
grains.

3, A quantity of oxigen and hidrogen answering to
14-187 grains of water.

On substituting for the water its elements, and propor-
tioning all the results of the analysis to 100 parts of ether
by weight, we find, that they contain

/ Carbon - s Seer 59:0.4
Hidrogen . - - = 21°86
Oxigen 8 = - 19-1

100.

‘Fhese results are reducible to the following: 10 grains of
ether consume for their combustion 61 cubic inches of ox-
igen gas, at 28 inches of the barometer, and 10° of the
thermometer [54:5 F. J, forming water, and 32°85 cubic
inches of carbonic acid gas.

The analysis I have just related was repeated four times,
and a mean of the four indicates in 100 parts of ether _

Carbon. o

Sa aaah:
Hidrogen - en fine - 22-14
Oxricen ye oy. = = 19°66
MIN a Ae at 4
100.

gas than will consume all the ethereal vapour, or merely sufficient
for this purpose, a black powder, or soot, will be deposited on the
sides of the cudiometer, and some free oxigen gas will remain in
the aeriform residuum of the detonation. ‘This. soot does not ap-
pear, when the etherised oxigen gas is detonated with a quantity |

of oxigen gas much superior to what is requisite for burning the
whole of the ethereal vapour.

Srcr.

COMPOSITION OF SULPHURIC ETHER.

Sect. IX. Examination of the Water produced by the
Combustion of Ether.

Hitherto I have taken it for granted, that the fluid resi- SEAT of
the water

duum of the combustion of ether was water, but without
any other proof, than a very superficial examination of the
slight dew, which is formed in the eudiometer by the in.
flammation of the ethereous vapour. It remains for me to
examine how far this supposition was well founded.

I burned several ounces of ether, in the apparatus in- from severat
vented by Meusnier to obtain the water produced in the ounces of ether.

combustion of alcohol. The water thus obtained from
ether is without colour,. smell, and taste, exeept some
traces of empyreuma, which it loses by exposure to the air.
It has the same specific gravity as distilled water, with which
it mixes without becoming turbid. It is not precipitated
either by nitrate of silver, lime water, or even acetate of
barytes. When [| evaporated one ounce of it to one, fifth
of its former weight, acetate of barytes produced a cloud
in it incapable of beimg weighed.

To estimate the quantity of sulphur contained in sulphu- Examined fog

ric ether by ancther proccess, I dissolyed one ounce of this
liquid in fourteen ounces of water. A stream of oxigen-
ized muriatic acid gas was passed through this solution for
ten hours. The ether was in part decomposed, but the so-
lution containing the products of this decomposition was
rendered but slightly turbid by acetate of barytes, till it
was reduced by evaporation to a gBrter of an ounce. As
the result is so trifling, it is impossible to conceive, that
sulphuric ether can derive any of its essential properties
from the presence of sulphur.

The water obtained from ether by the apparatus of Meus. A little lead-in

: : the water from
nier was rendered turbid and of a decp brown colour by ine worm.

829

sulphur.

the hidrosulphuret of potash. This precipitate arose from -

the lead acquired from the worm of the apparatus.

It emitted copions ammoniacal fumes at the approach of Appearance of
ammonia.

muriatic acid, and it appeared to me, that it changed the
sirup of violets greeninavery slight degree: but this change
of colour certainly did not take piace with the water ob-
tained from the combustion of ether under the mouth of a

5 glass

«

S3 COMPOSITION OF SULPHURIC ETHER,

glass jar. In the latter process the distillation is slower,
because we lose a larger quantity of water raised in va--
pour; and that which is collected, having been longer ex-
posed to the air, suffers more ammonia to fly off.

Further proof One ounce of the water obtained from ether in Meus-

of its PECSENCE. niey’s apparatus, and received in a.bottle into which I had
put a few drops of muriatic acid, in order to saturate the
ammoniacal vapours during distillation, was evaporated to
dryness in the temperature of the atmosphere. The resi.
duum it left was dry and well crystallized muriate of am-
monia, but mixed with a little muriate of lead. The mu-
riate of ammonia, separated from the metallic salt by a
fresh solution and crystallization, weighed one grain and
three tenths. ere thercfore its proportion was greater
than in the water obtained from the combustion of alcohol,

§ IV.
Perhaps the Though itis possible, that ether may contain a little ni-
ammenanot trogen, I doubt whether the ammonia, found in the aque-

whelly from the ‘
ether, ous product of the combustion, come wholly from the ether.

Whatever care I have taken in my eudiometrical trials, I
have not been able to satisfy myself, that the nitrogen gas
is not condensed into ammonia in the combustion of the va-
pour of ether. My results on this point have not been uni-
form. ‘the greater number have indicated- this condensa-
tion, and I am inclined to admit it, because the manipula-
tions and slight errours incident to Volta’s eudiometrical
process have a tendengy to produce the opposite effect, in
other words, to introduce nitrogen gas into the residuum of
the detonation *.

The water eva- + evaporated to dryness, in a very gentle heat, 288 grains

porated lefta of water obtained from ether burned under the mouth of a

figtic residuum. E ‘ 3 A |
glass jar. It left as a residuum a transparent varnish,
weighiag at most an eighth of a grain, and attracting mois~
ture from the air.

* If we operate over mercury, there is always in this metal, and
some interstices of the eudiometer, a little common air, which
mixes with the residuum of the detonation, to fill the vacuum it
produces. When the operation can be performed over water, the |
air contained in this fluid separates from it for the same reason, but f
it is in less quantity than from mercury,

- To

COMPOSITION OF SULPHURIC ETHER. 33}

To find whether the liquid 1 examined contained acetic i eae
ittie acetic

acid, I added a few drops of potash to 288 grains of water acid,
abtained by the same process as the preceding. The solu-
~ tion was saturated with carbonic acid gas, then evaporated
to dryness, and afterward washed with alcohol; when a
white salt was dissolved, weighing 0°7 of a grain, and very
speedily deliquescing. It had all the characters of acetate

of potash.

Thus the experiments I have just related indicate in the All the foreign
water produced from the combustion of ether the presence Maes a
of acetate of ammonia, a portion of sulphuric acid teo Fi
small to be weighed, and a. slight deliquescent varnish, the
nature of which [ could not ascertain. But the weight of
all these substances taken together is so small with respect
to the water holding them in solution, that it can make
very little difference in the proportions of carbon, hidro.

gen, and oxigen, assigned to ether in my last analysis.

Secr. X. Application of the preceding Analyses to the
Inquiry concerning the Changes Alcohol undergoes in tts
Transformation into Ether.

In considering the changes effected in the conversion of Comparison of
-alcohol into ether, I shall regard only the proportions of ae —
oxigen, hidrogen, and carbon, neglecting the nitrogen;
the existence of which in alcohol is certain, but question.
able in ether, though it is demonstrated, that the water
produced by the combustion of ether with the acid of at-
mospheric air contains a perceptible quantity of ammonia.
100 parts of alcohol are composed, 100 parts of ether,

§ V, of § VIII, of -
Carbon = . ~ 43°5 - - 59
Oxigen = - = 38 - - 19
Hidrogen = - - 15 ~ - 22
Nitrogen} My i 3°5 pall: 2

phd ii 100
100

These results show, that in equal weights ether eontains Alcohol loses
° . oxigen in be-
much more carbon and hidrogen, but much less oxigen, cies ee:

than alcohol does. Mr. Berthollet had already considered
ether

332 COMPOSITION OF SULPHURIC ETHER.

ether as a product, that must have more hidrogen and. less
oxigen than alcohol *.
Residuum from The residuum of the mixture of sulphuric acid with al-
caiphude aaa tceleal holds in suspension, after the ethereous fluid is sepa-
and alcohol. rated, a bituminous or resinous matter. + greatly loaded with
carbon. It will be asked, no doubt, how it is possible,
that ether should contain more carbon than alcohol, since
the latter has let fall a portion of this element in its conver-
sion into ether. But it must be remembered, that this re-
siduum contains likewise oxigen and Pawlegsen: which are
found either in the bituminous substance or in the state of
water; and that, if this oxigen and hidrogen be taken from
the alechol in larger proportion than the carbon, the latter
must predominate in the ether.
Two parts of | Lo judge whether my analyses lead to. this conclusion, I
alcohol yield have examined what quantity of ether a determinate weight
one of ether, 0 Om : :
of alcohol would producc; and I found by approximation,
that two parts of alcohol, if wholly decomposed, would
give one of rectified ether. . I obtained this result by the
following operations,
80 p. alcohol, A hundred parts of common spirit of wine of the spe-
Aa cific gravity of 0-845, and containing 80 parts of perfect
acids rotluged alcohol with 20 of water, produced, by mixture with an
tote impure equal weight of sulphuric acid, 60 parts of ‘ethereous fluid
patie not rectified, by stopping ie distillation at the moment
when the sulphurous smell is decidedly perceived, and the
oil begins to appear. I actually collected only 53 parts of
the ethercous fluid, but I found, from the difference in the
weight of the retort, that contained the spirit of wine and
sulphuric acid, taken before and after the distillation, that
60 parts had been produced. It is well known, thata cer-
tain quantity of ether always flies off in vapour during this
process, the weight of which could not be found in any
other way. In the following operations I continued to es-
timate the weight of the product by that of: the residuum.

Statique Chimique, vol. ii, p. 531 and following.
1b: d. and Proust, Mémoires des Savans étrangers, Institut
VO hs 4,

¥
a
i

hat,

’ The

¥ C@MPOSITICN OF SULPHURIC ETHER. 333

The 53 parts of ethereous fluid, which I suppose equal Be ceed
to 60, were mixed with liquid potash, and by the known ~:~’
processes of rectification afforded me 25:25 parts of ether.

The residuum of this rectification, which must be equal Residuum
to 34°75 parts, was separated from the potash by distilla- i ne

tion. It was miscible with water in any proportion, and
_had nearly the specific gravity of common spirit of wine.
I mixed it with ap equal weight of sulphuric acid, and it
: produced 23-25 parts of ethereous fluid, which, having
been mixed with potash and rectified, yielded 10-3 parts of
ether. !

The alcoholic residuem of this rectification was separated and afterward
from the potash, and mixed for the third time with sulphus =e
ric acid. ‘This afforded 3:2 parts of rectified ether. The
80 parts of perfect alcohol therefore produced in all these In all 38+75 of
operations 25-25 + 10:34-3:2 = 38-75 parts ef ether, or PU"? ther
nearly half the weight of thealcoholemployed. Ten parts
of water did not entirely dissolve one of this ether. Its
specific gravity was equal to 0:736 at 16° R. [68° F.]. I
did not wash it with water, but it would certainly have been
lighter, if I:could have obtained the specific gravity of that
which was volatilized. J have taken no account of a small
quantity of spirit of wine, which, according to the obser-
vation of Proust, always remains mingled with the sulphu-
ric acid after the first separation of the ether. I do not
think therefore J shall be far from the truth, if I say, that
200 parts of perfect alcohol produce by their complete de-
composition 100 parts of ether of a density cqual to 0-717
at 16° R. [68° F.].

If we take the difference between 200 parts of alcohol Elements left
and 100 of the ether produced from it, reducing the two ta ages
liquids to their ultimate elements, we shall have a remainder ration of the
equal to 100 parts, which, setting aside the sulphuric acid, pt
express the elements left by the alcohol after the separation
of the ether; and which include
~ Carbon .- - - 28
Oxigen - - - aT
Hidrogen - : 8
Nitrogen

This

334 COMPOSITION OF SULPHURIC. ETHER.

This residuum then must contain a considerable quantity
of carbon, though the ether is more loaded with it than the
alcohol. It will no doubt be remarked, that this residuum
contains oxigen and hidrogen nearly in the proportions that

~~ constitute water, or in that of 7 to 1. We must admit ~
therefore, that 100 parts of ether arc nearly equal. to 200
parts of alcohol, minus 28 parts of carbon, and 65 of
water, the formation of which has been occasioned by the i
suiphuric acid.
Not a perfect The black substance precipitated from the alcohol is not,
separation of ag has been said, pure carbon: nor does it appear, thatthe |)
the products. |. >’, : :
Jiquid formed with the elements of alcohol.by the sulphuric ~
acid is pure water. An imperfect separation of products _
takes place here, as in all decompositions effected between i
substances that have a very movable constitution, and little
disposition to solidity.
The result ap- In this paper I have attained nothing farther than aps
eS eae proximations, but in researches of so difficult a nature,
these results are the only ones we can expect. They can-
_ not acquire great precision, but by repeated analyses suc-

cessively improved.

Note on the Vapour of Ether, § VII, p. 327.

Specific gravity In a paper read to the Society of Natural History and
ci as va- Philosophy at Geneva, December, 1804, I gave the parti-
colars of an experiment made for the purpose of ascertain-

ing directly the specific gravity of the elastic vapour of ether

invacue. ‘The conclusions drawn by de Laplace from the
observations of Watt, my father, and Gay-Lussac, show

decidedly, that the elastic vapour of water is found in the

same quantity in vacuo and in the air at the same temper-

ature; but we cannot apply the same law to ether, except

by analogy, or very indirect experiments. (Sce the expe-

riments of Mr. Dalton.on the evaporation of cther. Man-

chester Memoirs, vol. V, or our Journal, vol. VI, p. 266.)

Experimentto I procured a matras, the. body of which contained 30
nea cubic inches, and the cylindrical neck of which was 32
inches long, and about three lincs in diameter. On, this

neck I measured off. a length of about two inches, and

weighed the quantity of ether reqnisite to fill this length.
The

COMPOSITION OF SULPHURIC ETHER.

To)

The matras was filled with mercury, except aspace equal to
that of the small column, that had been measured, and this
was filled with ether. I then closed for an instant the ori-
fice. of the matras, and inverted it in a basin of mercury,
under which [ opened it. Thus the matras became a kind
of imperfect barometer, terminating above in a hollow ball
void of air, but filled with the vapour of ether. The length
of the column of ether, previously measured, was dimi.
nished above a third by the formation of the vapour I have.
mentioned. ‘This diminution reduced to weight, and com-
pared with the capacity of the body of the matras, gave me
the bulk and weight of the vaponr of ether in vacuo, and
proved, that they were equal, at least as far as could be ex-
pected in an experiment on 30 cubic inches, tothe bulk and
weight of this vapour in atmospheric air, in nitrogen gas,
and in hidrogen gas. The vapour of alcohel is too light,
to afford sufficiently decided results by this process.

In this experiment there are some precautions to be taken, Necgssary pre-
in which however there is no difficulty, 1st, to expel from Cautions.
the surface of the mercury contained in the barometer a
small quantity of liquid ether, which lodges between the
mercury and the inside of the neck when the matras is in-
verted. This may be effected by surrounding it with a cloth
warm enough to reduce this ether ito elastic vapour.—
2dly, it is necessary to estimate by a comparative experi-
ment, made at the same time and in the same place, with a
matras of equal size, the weight of the liquid ether that ad-
heres in small quantity to the inside of the body filled with
vapour. 3dly, in stopping the matras to invert it, the
stopple must not touch the ether. 1 avoided this source of -
errour, by fixing in the neck of the matras, near its orifice,

a tube closed at the bottom, and filled with the ether in.
tended for this experiment.

I found thus, that a cubic foot void of air, or filled with 202. of etnes
air, could contain, ata temperature of 18° R. [72°5° F.], a Ue ee
about two ounces of invisible ether in the state of gas. The i
extraordinary weight of this vapour instructs us how much
ether is lost, by employing large vessels or globes passing
one into another, for the purpose of coudensers and re-
- Ceivers in distilling this fluid.

A know-

336 COMPOSITION OF SULPHURIC ETHER:

Specific gravity A knowledge of the specific gravity of vapours may fur-
of vapours af- (+. d y : . a enw
fords useful Dish considerable resources in chemical analyses: By the
data. help of this datum, and detonating a few cubic inches of

‘oO

the vapour of ether with oxigen gas, I was able to deter-
‘mine with more precision the proportions of oxigen, hidro-
gen, and carbon in ether, than by burning two ounces of
this liquor ina red hot tube. I obtained results nearly as

accurate with the vapour of alcohol.

Vapourofether "Phe yapour of ether may bé employéd with as little exe

employed to as- Meee Aon ‘ 7 f

certain its afi- pense for determining the affinities of this fluid to different

nities to pitch, substances. I introduced over mercury 12 grains of
pounded pitch into 20 measures of atmospheric air dilated by
the vapour of ether, which consisted of 10 measures of air
previous to its dilatation. ‘The 20 méasures occupied a co-
lumn 6 inches high, and 6 lines in diameter; and were re-
duced to eleven measures by the presence of the dry pitch,
which became semifluid in thus condensing almost the whole
of the ethereous vapour.

suet, I obtained a somewhat less condensation with 12 grains
of suet, 20 measures being reduced only to 13. The suet
was softened.

India rubber, Twelve grains of caoutchouc, very minutely divided, re-
duced 20 measures to 15.

camphor, Twelve grains of camphor reduced 20 measures to 16.
The camphor was moistened.

wax, Twelve grains of yellow wax reduced 20 measures to 16.

Pac, The vapour had very little action on gum lac, 12 grains

of this only reducing 20 measures to 19.
and tragacanth. A similar quantity of gum tragacanth produced a con-
densation too small to be measured.

ena

Specific gravity The knowledge of the specific gravities of the vapour of
capo ue Ua water, of alcohol, and of ether, may give us an idea of
of the volatility the law, which the gravities of vapours followin proportion
ce eae to the volatility of the liquids from which they arise. Water
them, at a given temperature is less evaporable than alcohol, and
alcohol than ether. ‘The elastic vapour of water is lighter
than that of alcoho]; and the vapour of alcohol is lighter
than that of ether. The specific gravity of elastic vapours

then,

+

m
evar

Wicholeons Philos Journal VoL EELPLG p.

Wan ope y i rn 2.

| J;

Had
WY

SS
SS

Vy

mene te

HA

cc
|
|

We

AOU NGAALHSAEH

lh Collecrs Shifts Shere re,

IMPROVED SHIP’S STOVE. 337

then, at equal temperatures, appears to be in the ratio of
the volatility of the liquors that furnish them. The most
volatile bodies are those, which, in similar circumstances,
produce the heaviest elastic vapours.

Observations made by several natural philosophers indi- Gasses mix uni-
cate, that gasses of different. natures mix uniformly, and iebsee i, °
do not arrange themselves according to the natural order of ic wane ae
their different specific cravities: but if this observation
were unfounded, if the vapours that emanate from the ter-
restriai globe arranged themselves in the order of their gra-
vities, those that belong to the least volatile bodies, as the
earths and metals, would be those that would occupy the
highest strata of our atmosphere, supposing its temperature

uniform.

II.

Description of an improved Ship’s Stove, by Mr. Josrrr
Cottier, No. 11, Crown Street, Soho*.

SIR,

I HEREWITH send you a model of an improved ship
stove, which may also be employed in drying houses, &c.,
with more safety than those in present use.

I submit it to the inspection of the members of the So-
ciety, who, I make no doubt, will see its advantages, and
am, Sir,

Your humble Servant,
JOSEPH COLLIER.

P.S. The expense of one twelve inches diameter will be
about eight pounds. |

Fig.1, Plate 1X, represents the stove, with the front Description of
partly closed by the circular slide A, which is moved from 2 Ship's stove,
the back by the brasshandle B. C amovable plate attached
to the slide 4, now supported by the latch catching a pin, _

* Transactions of the Society of Arts, vol. xxv, p. 93. Fifteen
guineas were voted to Mr. Collier for this invention,

Vou. XXI.—SurgLemMent. Z by

338

The machine
@escribed.

CONTRIVANCES TO SAVE PEOPLE FROM DROWNING.

by which means it acts as a blower to cause the fire to burn
more briskly, but which slides down also to shut the fire up.

D another plate, now hanging on its latch, but which
can be let down to shut up the ash pit or dish J, which can
be drawn out when the side facings FF are pulledup. &
a circular plate or cap, which slides so as to shut the chim-
ney up close. .

Fig. 2, The body of the stove with the slider 4 moved
round to the back, and thus leaving the fire-place com-
pletely open. ‘

‘%g. 3, The ash-dish shown separate. @

Fig. 4, One of the side facings taken out to show the
figure H, which slides into a hole made in the corner of the
stove to hold it.

Ith.

Account of a Floating Light calculated to save the Lives of
Persons, who have the Misfortune to fall overboard in
the Night from any Ship. Invented by Mr. Wm. Surp-
LEY, Founder of the Society for the Encouragement of
Arts, Manufactures, and Commerce *.

‘Tans floating light consists of a hollow vessel in the
form of a boat, made of tinned iron plate, ab, Fig. 5,
Plate TX, the joints of which are carefully soldered, so as
to. keep out the water. The boat is 27 inches long, 13 broad
in the middle, and 12 deep, and is sufficient to support @
man inthe water. From the gunwale of theboat, oneach
side, projects a handle c d, soldered fast to it for the man
to hold by.

ef is a metal ring connected with the boat by four up-
right pieces, within which is another smaller ring, turning
on pivots, fastened to the ring ef, in the direction of the
boats length; the internal ring supports a small lantern, 2,
by an axis which passes through it, and is pivoted into the
ring at each end, in the direction of the boat’s breadth. By

* Transactions of the Society of Arts, vol. xxv, p. 94. |
means

CONTRIVANCES TO SAVE PEOPLE FROM DROWNING. 339

means of these rings the lantern will remain in a vertical
position, independent of the boat’s motion.

On the first alarm of a man falling overboard in the {Its application.
night, the candle is to be lighted, and the machine lowered
into the sea by the rope; if the man should be ata small
distance from the ship, he may, by means of the rope, be
taken on board immediately on his reaching the machine,
if not, the rope may be secured on the iron reel, to prevent

-its unwinding, and cast off, and the light will direct the
man where to find it, and holding fast by the two handles
it will support him in the water.

Fig. 6, h, is a rope ladder, having a lantern attached to
it, as well to direct the person in the water to the rope lad-
der, as to enable the persons who lower the ladder to let it
down till the cross-bar k reaches the water; /is 4 hook to
hang the floating light upon. Ig. 7, m, is the reel for the
line, by which the floating-light is to ts lowered.

It is proposed, in order to make this float useful, that it The niateip al-
be placed every night under the care of the officets on eee
watch; that its lamp be frequently trimmed and supplied
with fresh oil, and its wick moistened with oil of turpentine,
in order that it may take fire with the least touch of a lamp Directions for
or candle; and whenever the alarm is given of any of the i '¢
sailors falling overboard in the night, the officer on watch
may light the lamp in the lantern belonging to the float as
expeditiously as possible, and let the float down by a small
cord, wound upon an iron reel, into the water, till it has
floated about one second of time, and the float is a little
way out of the perpendicular of the small cord. THe is then
to secure the cord on the reel, to preveut its unwinding, and
toss it overboard. The reel will sink down, and pull the
line almost perpendicular, and thus it will not be liable to
éntangle the person when he swims to the float, who, when

‘he has got hold of the handles of it, may move it very fast
which way he will, only by striking his legs in the same
manner as he does when heswims; and as the light of the
Aamp will be a certain guide for the person fallen overboard
to find the float, so it will also direct them in the ship to
find the man and float: And when the ship has tacked about,

422 and

540

Ready contri-
vance to keep
a person afloat
that cannot
swim.

CONTRIVANCES TO SAVE PEOPLE FROM DROWNING.

and is come to the float, then the following method is pro-
posed to take up the man and float into. the ship: viz. A
lantern, with a rope ladder, may be let down by a cord
from the ship, till a cross-bar below the lantern touches
the water, which may be seen by them in the ship by means
of the light from the bottom of the lantern; and thus the
man in the water may lay hold of the cross-bar, and fix
his feet on one of the steps of the rope ladder, and he may
then lay hold of theiron bar or handle of the float with one
hand, and hang it on thé hook of the rope, above the cross

bar; which being done, the man and float may be both —

safely lifted into the ship.

This ingenious and humane contrivance was presented to
the Society by Mr. Shipley in 1776, and the silver medal,
with a letter of thanks, was voted to him. The machine
has been preserved in their repository, but as they consider
it to be not sufficiently known, they have published the pre.
ceding account in their Transactions for last year. I re.
member observing, in the time of the American war, that
several of our ships kept a small hull of a vessel lashed to
the rails of their stern gallery, or their tafferel, ready to
cut away the moment a man fell overboard. This hull had
a single mast, with a red flag, that the waves might not
conceal it from the sight of tke man in the water; and was
of course much preferable to the common resource, a hen-
coop, or a grating. Such a flag might very easily be added
to Mr. Shipley’s floating light, for use in the day.

While on this subject it may not be amiss to notice the
contrivance, & believe of the lateadmiral Locker, by means
of which a person who cannot swim may assist another in

danger of drowning, and at least keep him afloat, till far. .

ther help can be obtained, If aman tie up his hatin a
handkerchief, with the knots meeting in the centre of the
opening of the crown, he may go into the water safely to
assist another, holding the knots in one hand so as to keep
the hat uprights for the air in the crown of the hat, while
held in this position, will be sufficient to keep two persons
from sinking.

IV. An

)

ON THE SUGAR OF GRAPES, 3A]

IV.
An Essay on the Sugar of Grapes ; By Prorrssor Provsr.
Concluded from page 316.

Arrer observing, that sugar is become an indispensable If the importa-
article of consumption, Professor Proust expatiates on the bate
necessity of finding a substitute for that of the West Indies, that of the
should their intercourse with Spain, France, and other con- ae ay ee
tinental countries be cut off; and for this purpose he recom-

mends the sugar from grapes. This he confesses is not

precisely the same with that of the cane, but may very well

supply its place. Without being refined it will answer

every purpose, in which colour is no object, as for sweet-

ening coffee, chocolate, or dishes made of milk, in phar-

maceutical preparations, &c.

When refined, says Professor Proust, it is perfectly white, Its qualitics,
but will not acquire the solidity of that of the cane, on
account of its granular and porous crystallization; so that
it cannot be made into loaf sugar, unless the art of the
sugar-baker furnish him with resources, which I have
no room to expect from the trials I have made.

Its sweetness is evidently inferior to that of the sugar
from the cane, so that it must be used in larger quantity ;
aud it is not so readily soluble. It dissolves entirely in
spirit of wine; but it separates from it much sooner than
that of the cane, and always in tuberculous, granular
crystals, in which no determinate arrangement of parts can

be perceived.

_ Presuming, that a comparison of the juice of green Contents of the
grapes with that of the perfectly ripe fruit will not be un- “™™PS Juice.
interesting, I shall first give a sketch of the results I

obtained by analysing it. In it are found, 1, tartar; 2,

sulphate of potash; 3, sulphate of lime; 4, citric acid in

abundance; 5, malic acid a very little ; 6, extractive matter ;

and, 7, water.

The citric acid is the chief base of this juice. It con. Would furnish
tains neither gum nor saccharine matter: and in those years “““ °! lemons.
when the dearness of lemons does not allow us to extract

- their

342, ON THE SUGAR OF GRAPES.

their acid in Scheele’s mode, the juice of unripe grape
may be employed for the purpose with more advantage than
has been supposed.

This converted But the warmth of the weather promotes the maturity of

pe vest and this juice; the citric acid gradually di that

gum, : gradually disappears, so tha
scarcely any traces of it ‘can be discovered in the ripe grape;
and the products that occupy its place are the two species
of sugar mixed with a little gum. The elaboration of the
juice therefore consists in transforming this acid into gummy
and saccharine products, in proportion as the fruit ap-
proaches maturity.

The elements of the citric acid do not differ from those of
by parting with sugar and gum, as has been discovered; but, since analysis
paigen has found likewise, that it contains oxigen, or the acidify-

ing principle, in more abundance than the nutritious pro-
ducts that assume its place, does this acid, during the
ripening, merely lose a part of its oxigen, so as to ap~
proach nearer their nature? or does it raise itself to the
or acquiring same point by acquiring a larger proportion of carbon?
aan This admirable metamorphosis passes before our eyes every
year, yet nature has covered it with a veil impenetrable to
them. To return to the fruit of the ripe grape.
Contents of the This juice, as it flows from the fruit in the press, con-
| Tipe juice. tains substances of two kinds, some simply mixed, others
in solution. ‘The parts mixed are, first, the fibrous and
calcareous pulp, which composes the organization of the
berry ; and, secondly, a portion of the fecula, which we
call glutinous, on account of its resemblance to the animal.
ized substance of cheese termed gluten.

These two substances, if diluted, may be separated by
the filtration of the juice, though imperfectly, on account
of its viscosity, and their tenaciousness, which choak up
the filter. But they may he separated much better by heat-
ing the juice to ebullition, because they coagulate, and rise
to the surface. When scummed, and strained through
flannel, the substances remaining dissolved in the clarified
Juice are, .

1, A portion of fecula; 2, crystallizable sugar ; 3, suga
‘not crystallizable; 4, gum; 5, extractive matter, either
white, or tinged red, according to the species of grape.

When

ON THE SUGAR OF GRAPES. 343

When the juice of grapes is boiled down as far as can Its rob,
be done without danger of altering its qualities, it affords a
rob, the quantity of which is proportional to the saccharine
quality of the grape, and varies from 18 to 32} per cent.

It is difficult however to avoid some degree of empyreuma,
particularly if the juice be acidulous. This alteration di-
minishes the quality of fermenting in the rob redissolved in
water, though without annihilating it, as Beccher had
concluded from his experiments. ‘The liquid sugar of the
cane teo, as Duthrone informs us, is much sooner altered

by boiling than the solid sugar.

The rob boiled down to a certain point crystallizes in a Crystallizes.

short time. It congeals into a spongy mass, more or less
moistened with a sirup, that has a tendency to drain off.
Its crystals, when drained, are a mixture of tartar and cry-
stallizable sugar. It was this product, extracted from the
muscat grape of Fuencarral, which, after having under-
gone a few purifications, led me, instructed as I was by
Duthrone’s excellent work on sugar, to treat the juice ef
grapes like that of the sugar-cane,

As the juice contains acids, that hinder the extraction of Mode of ex-
the sugar, the first step is to free it from these. After the ie he
must has been scummed, and while it is nearly boiling, a
lixivium of wood ashes is to be added by little and little, as
long as any effervescence takes place. The acids may be
known to be saturated by tasting the liquor, which will
then have only a saccharine taste. It is then to be boiled
down to about half, and left to cool im vats, or even in the
copper boilers, for there isno danger of verdigrease as in —<
preparing the rob. While it thus stands, the tartar and
citric acid, if there were any, being converted into salts of
difficult solution, subside with the excess of the ashes, and
the sulphate of lime that was in the juice of the grape.

The malic acid, converted into malate of lime, remains in
the liquor in consequence of its great solubility.

The must prepared in this way indicates 25° or 26° on Not to beboiled
the arcometer. If it were boiled down ‘beyond this, the ‘°° ™¥ch-
subsequent clarification would not be so easy, on account Claifcation,
of its thickness. It is then to be beaten up with whites of

ges or bullocks blood, heated, scummed, filtered, and
boiled

o44

Must boiled
down has a
slightacrimony,
and in a little
time becomes
solid.

For this it
should not be
too much
boiled.

ON THE SUGAR OF GRAPES.

boiled down to the consistence of a sirup, whieh may bé
more or Jess thick, according to the use for which it is ins
tended. This rob, divested of its principal acids, answers
as we see to the first product of the cane, saturated and
boiled down to the point ai which it takes the name of
muscovado.

When the must has been thus prepared, it affords us a
coloured sirup, though extracted from white grapes. Its
taste is sweet and pleasant; but if as much as a spoonful be.
swallowed, it affects the throat with that slight impression
of acrimony, which is experienced from yellow honey. It
condenses in eight, fifteen, or twenty days, mose or less,
according to the degree to which it is boiled down, into a
yellow, granular mass, of sufficient consistenty to be
pressed into pots, without flowing out if they be set upside
down. The sirup that has not been most boiled is the first
to become solid. The sugar of grapes appears to require a
certain quantity of water for its crystallization, as it is not
found in sirup too much boiled. Hence this is longer before
it becomes solid, but then it acquires-a consistency more
convenient for carriage. Lastly, in this state the musco-
vado of grapes has the consistency, colour, and appear.
ance of that of the sugar-cane. A vessel that contains but

sixteen pounds of water will hold twenty five of this sugar,

Sugar of the
grape compared
with that of the
cane,

so that its specific gravity is to that of water rather more
than as three to two.

If muscovado of the grape be compared with that of the
sugar-cane, we find, that the latter adds to a slight bitter-
ness a peculiar aroma, the character of which is very
striking in rum: while that of the grape has no sensible
aroma, being a sugar with a flavour of roasted fruit. This
taste, as well asits colour, is owing to the concentrated
extractive matter; which has the common property of its
genus, that of becoming darker coloured, both by simple
exposere to the air, from-which it attracts some principle,
and by being heated. It is this that gives ihe muscovado
of the grape its orange colour; an effect similar to which
is produced in the sugar of the cane, the juice of which is
nearly colourless. If the muscovado of the grape be di
luted with a quantity of water equal to what it has lost, w

oht:

ON THE SUGAR OF GRAPES, 345

obtain a regonerated must far darker coloured than the
fresh: but it is to be observed, that the latter, if a con-
siderable surface of it be exposed to the air, soon acquires
a similar tint. ‘These effects are peculiar to the extractive
principle, the saccharine and gummy being iususceptible
of it. Hence it follows, that the change it experiences
from these causes united must extend to muscovado, and
communicate to it, as to all roasted fruits, more taste and
colour. The following is the proportion of the products
discovered in this muscovado by analysis.

bs, '.02
Crystallizable sugar - == Ss 75 Its component
Fluid sugar = ine 24.7 ears
Gum - é 24 % 5
Malate of lime = E 4
100

The quantity of extractive matter could not be estimated, A little extract.
but it must be very little, since the melasses, notwithstand-
ing its colour, is perfectly transparent. —__

To discover the proportion of the two sugars I employed Proportions of
the following means. I set to drain heaps of muscovado, nie i
evaporated to such a point as experience had taught me was
most favourable for the separation of the sirup, or fluid
sugar. The latter, collected and kept some time secured
against evaporation, has still let fall pulverulent sugar,
and in such a quantity, that, from many experiments of
this kind, I am persuaded the crystallizable sugar is more
than seven eighths of the muscovado. Notwithstanding
this, I have not thought proper to set it down above at
more than three fourths; and this I mention, that more
confidence than it deserves may not be placed in a process
that could not possibly be accurate.

But it is not thus with its other component paris, the gum The gum se
and the malate. If to a hundred parts of muscovado re- rap bysal:
duced to the state of a thin sirup alcohol be gradually and then the
_ added, the gum is first deposited. The fiuid being decanted mnalate,
off, and more alcohol added, the malate will fall down.

As If have frequently repeated this experiment with quantities

of sixteen hundred grains, I have reason to believe, that the

proportion of these is given pretty accurately in the table.
if

8346 ON THE SUGAR OF GRAPES.

Separation of If the alcoholic solutions of the muscovado be kept cos
si get id vered with a paper only, the solid sugar will separate from
rom ealco- , p .

hol imperfect. it by crystallization, but never so completely as to be able

to calculate the quantity, because the fluid sugar retains a

good part. The same thing, as has been seen, takes place ~

with honey thus treated.
Piast the The gum of the grape is without taste or colour, and
grape. does not differ from what I have found in apples, mulber-
ries, medlars, apricots, plums, &c. Jt is one of the nu-
tritious products of vegetables, resembling gum arabic.
Malate of lime lhe malate of lime, we see, is but in small quantity.
= called tothe Tf the mixture of an earthy salt in a substance intended for
food should be thought an inconvenience by those, who have
no idea of the composition of vegetables, I would observe
to them, that this salt exists ina great number of. fruits,
particularly the melon and love-apple; that the sulphate of
lime is found in much larger quantity in most of our pulse,
in wine, in the waters we most prize at Madrid, in several
fruits, in the apple, medlar, quince, potato, &c. without
having the Icast effect on our health.
Sugar of the As a condiment the muscovado of the grape does not
cer aiag sweeten as much as common sugar, on account of the water
¢ommon. of crystallization it contains, and the inferior sweetness of
its crystallizable sugar. To sweeten a pint of water as
much as custom requires, two ounces of the sugar from the
cane are sufficient; but two ounces and half of that of the

grape are necessary; and with these proportions both the

solutions mark the same degree on the areometer.
Cat ink rie: The solution of this muscovado changes neither the in.
ther free acid, fusion of litmus nor solution of isinglass. Muriate of tin
alkali, nor tan- tis : - Hye * i
nei. precipitates from it the colouring principle, as it does that
of the juices of the carrot, melon, grape, sugar-cane, and
all fruits.
It is very well adapted to milk, coffee, and chocolate;
which it sweetens agreeably, without giving them any par-

lis uses.

ticular flavour, that can be disliked, as yellow honey does; .

and the slight-acrimony mentioned in the beginning disap-
pears, because it is only the effect of the extractive matter
too much boiled down,

The

ON THE SUGAR OF GRAPES. 347

The muscovadoes I have examined were extracted from Black grapes

the white grape, called alvilia, and the black, called the 24#erded more
than white, and

Arragon grape. The first afforded twenty-six per cent, scarcely darker

the second thirty. The latter is not perceptibly higher co. Coloured.

Joured than the other, as the skin of the grape alone is co-

loured, if care be taken not to mix with the must the juice

extracted by pressing. It will perhaps excite surprise, that

the must, after being freed from its acids, affords a quantity

of muscovado equal in weight to the rob: but the reason of

this is, that the tartar, the only acid that precipitates with

the lime, and a few particles of calcareous citrate and sul-

phate, are found in it but in very small quantity. Of this Very little tar.

we may judge by the following result, though we may pre. ‘ ™ the grape.

sume there is a little more in the common grape than in the

muscadine. A pound of the latter duly treated with spirit

of wine does not afford more than 48 grains of tartar.

It is not the tartarous acid, but the malic, that gives Their acid the
grapes their sharpness: and this too is but in small quantity, aes
since a pound of the juice of the muscadine grape does not
afford above 40 or 45 grains of malate of lime. Now if
we reckon, that this salt contains one third of its weight
of earth, it will follow, that a pound of the fruit does not
contain much above 30 grains of acid.

Hience we may conclude, that the juice of the grape freed Grape juice
from its tartar, an effect that may be obtained by simply ge peed
boiling it down to one third, is already a muscovado little third almost
- different from that of the cane, which equally contains ma- ee
lic acid, if no lime have been employed in its preparation.

As the sugar of the grape approaches so near that of thedransparent
cane in its qualities, we may understand why the rob of the rie Nae
muscadine, dried and poured on a marble, affords a trans.

parent lozenge, without colour, pleasant to the taste, and
appearing like barley sugar: but it has the defect of soon

growing moist, as the malic acid and liquid sugar occasion

it to deliquesce in a short time.

It is remarkable, that the common people have already The art of su-
approached very near the art of making grape sugar, in there rane
preparation of their rob; but the last step, that remained proached by
for them to take, required a kind of reflection, for which ‘© ee
their education is seldom adapted. At Arganda, near Ma. ee

drid,

S48 ON THE SUGAR OF GRAPES,

drid, and in other places, to prepare their rob they begin
by boiling separately with a certain quantity of lime the
juice of grapes, and that of other fruits they intend to mix
with it. Thus, taught by necessity to free them from the
acids, that would injure the sweetness of the rob, they
employ a process truly chemical, to which theory, so long
preceded by practice, cannot refuse its sanction.
The grapemus- The muscovado of the grape will some day no doubt be
covado an ex- ysed for other purposes beside food, when it is known, that
eelient remedy... i °
for scurvy, in it are united the two vegetable products acknowledged
to be best adapted for effectually remedying those diseases
that are occasioned by the corruption of the blood, or that
impoverishment of the humours called scurvy. The em.
ployment of the two kinds of sugar with a particular view
to ascertain their effects, particularly freed from all the
Galenieal farrago that might weaken their powers, may fur-
nish the physician with means of cure better adapted to his
views, than those imaginary antiscorbutics, that still con.
tinue to usurp the place of efficacious remedies, than those
salads of scurvy grass, brook-lime, and water-cresses, the
heating acrimony of which could not fail to kindle cons
sumptive fires, if the sick to whom they are prescribed were
not protected from these by the dissipation of the qualities
, Of the drugs by our infusions, clarifications, and-sirups.
Let us hear what Tourlet says, speaking of the scurvy:
Generalremee °° Fresh vegetables, pure air, aliments that contain most
dies for scurvy of the mucoso-saccharine principle, always infallibly cure
the scurvy. The mucoso-saccharine principle contained in
most fresh vegetables, in honey, in sugar, and in various
fermentable substances, is of all things best calculated for
assimilation, and consequently for the regeneration of the
fibrine of the blood.
Marea food <¢ Animalized substances are not always the best fitted
not alwaysmost for nutrition: on the contrary, those aremore so, that re.
fFuucritious.
elaborates them, and renders them more capable of being
assimilated with the substance of the individual, who uses
them as foog. Children, for instance, thrive much better
on mucous and fermentable substances, than on such as
are more animalized. Experience, against which there is
no

quire for their animalization a sort of fermentation, which

ON THE SUGAR OF GRAPMR 349

no arguing, has incontrovertibly proved, that the use of
meat is always pernicious to the scorbutic.”’
The refining of grape sugar must differ but little, if at Refining the

all, from that of the muscovado of the cane. Both being eas Bi iy B
composed of two sugars, that require to be separated, no.

thing is required but to boil down the prepared must to a
proper degree of consistency, which every refiner by trade

will discover. ‘The muscovado of the grape, brought to

this point, will condense within a few days into a cellular
granulous mass, the intervals of which will be filled with

fluid, the common effect of that attraction, which induces

the particles of the two sugars to unite with those of their

own kind, and separate into two products. These masses

being drained, the result is sugar in its first stage of refine-

ment and sirup. The latter, exhausted by fresh crystalliza-

tions retains the malate of lime, gum, and extractive prin-

ciple. These four substances equally form the melasses of

the sugar-cane; but that of the grape has not the same un-

pleasant flavour.

The sugar of the grape however does not crystallize like Cannot be .
that of the cane; its grain is pulverulent; and as the masses Bes
it yields have little consistency, it appears to me doubtful,
whether it can ever be brought to such adegrce of hard-
ness as that of the cane: at least it would require manage-
ment, with which I am unacquainted.

If the sugar of the grape in this point of view afford us Dissolved in
a prospect of an important article of trade,» the product of wien oe

its fermentation promises us no lessadvantage. Nature has neously:
given this muscovado'such a tendency to fermentation, that
it requires nearly the addition of as much water as it had
lost, to produce this effect: and in cold countries, where
the warmth necessary to this purpose is deficient, if a little
dried wine-lees be added to this regenerated must, its fer-
mentation will be still more active, and then it will proceed
as briskly as in temperate climes.
One measure of this muscovado dissolved in three of and one part
water forms a liquor of equal density with the juice of the epee :
Arragon grape, which indicates 17° on the areometer.
_ This produces four measures of a wine of the colour of
that of Malaga, and in which a slight flavour of baked
9 fruit

350 ON THE SUGAR OF GRAPES.

fruit is perceptible. It is as strong as the best wine of
Ta Mancha. As it is extremely intoxicating, certainly nei-
ther the beer nor the mead of Russia can be put in compe-
tition with it for strength or goodness. The muscovado of
the grape therefore may furnish the north with a base adap
ted to the manufacture of all sorts of wine.

The skins of If the skins of black grapes be added to this, it ferments

the black grape with equal briskness, and acquires not only their colour,

So eS had a portion of their astringent principle, which in mo-

prove it. 5 ad

derate quantity improves the taste of all wines, and their
quality of keeping.

Valuable theree This muscovado imported from the south into the north

forein north- solves a problem of great importance to cold countries.

ern countries. me .
This is, that with the sugar of the grape wine may in future
be made in Siberia as readily as in the kingdom of Valens
gia. And if this production were considered only as a mas
terial for making brandy, what advantage would it afford
in the ease and safety of conveyance! Would not beer too
be much improved, if its fermentation were promoted by a
portion of this muscovado *?

The

Barley contains * The meal of barley contains but ten or eleven per cent of pro-
little soluble ducts soluble in cold water. ‘These consist in equal parts of gum

mater: and mucoso-saccharine matter, rendered acrid by a little extractive,
and a few flocks of glutine that separate while boiling.
Its farina. The farinaceous part consists in two or three and thirty parts of

starch, and seven or eight and fifty of a granular insipid substance,
which is separable from the starch by washing either in cold or boil-
ing water.

Distilled. By distillation it yields all the products of starch, with some in-
dications ef ammonia. Nitric acid employed without heat extri-
cates from it a very little nitrogen.

Malt contains Barley that has been perfectly malted does not yield as before

more soluble ten or eleven per cent of soluble products, but thirty per cent,

mBEEETy though of the same nature.

and less starch. 1 he farinaceous part consists of seven or eight and fifty parts of |
starch, and twelve or thirteen of the granular substance. The
changes produced in the grain by germination therefore fall on this.
‘The same substance is found in the flour of Indian corn, and cons
stitutes near half its bulk.

Not much As the gummy part has no share in the fermentation, and is still

sugar in it. found in the beer, malted grain contains only about fifteen per

cent

ON THE SUGAR OF GRAPES. $51

The celebrated Glauber asserted in his Prosperitates Gcr= Glawber said
manie, that, if the rob of grapes were sent to countries, the rob of
to which nature has denied the vine, they might make their ae ke hg
Own wines, by adding to this quintessence of wine, as he
termed it, the water of which it had been deprived. And
he said this might be done in all places, and at all seasons.

This idea was certainly ingenious, but he should have Beccher denied
confirmed it by experience. He did not; and was openly
contradicted by Beccher in terms not very civil, who as-
serted, that he had tried the experiment in vain for a whole
year.

Tn defense of Glauber it may be said, that the sugar in It will ferment
the rob, being more or less affected by the reaction of the pacha oa =
tartar and other acids, remains so long inactive, as to lead too. much
to a belief of its fermentable property being extinct. Not. eed.
withstanding this however, it will ferment, and the period
may be accelerated easily by the addition of wine lees. I
have even now some wine from such a fermentation, which
is very strong, and the boiling down has given it a flavour,
that is far from unpleasant. Butin some parts of Germany
the grape has the double inconvenience of being loaded with
tartar, and poor in saccharine matter, since it requires six
tuns of must to make one of gob; probably therefore it
would not be so much disposed to ferment as in hot coun-
tries, in Spain particularly, where the poorest juice of the
grape commonly yields a fourth part of sugar and very lit.

Meacid, ‘

_ It may not be improper to introduce here the remarks I
have had an opportunity of making during the course of a
few summers on the fermentation of clarified must.

When the juice of the grape has been clarified by heat Clarifed must
and filtration alone, if always continues a little foul, be-

cent of saccharine matter. If now we compare barley malt with
the muscovado of the grape with respect to their fermentable parts,
we shail find, that one hundred weight of the latter nearly equal
seven hundred weight of the former. Hence we may judge of the
advantage, that would accrue from employing a portion of this
muscoyado in making beer. -

Water heated to 50° does not dissolve starch: this is the reason
why the water in brewing is seldom allowed to exceed this point.

ios cause

352

ferments
though freed
from fecula.

The cause of
the fermenta-
tion is in the
liquid sugar.

ist stage of
fermentation.

2d stage,

Sd stage.

aoe after it is over.

5
ON THE SUGAR OF GRAPES.

cause it retains in solution a portion ef the fecula that has

*been mentioned, and the nature of which has been come

pletely ascertained by Fabbroni and Thenard. This fecula
is retained there apparently by the intervention of acids,
since we do not find it in the juice, that has been saturated
by the carbonate, and clarified with whites of eggs; in
which way alone it is obtained perfectly clear.

Fabbroni and Thenard have considered this fecula as a
ferment indispensable to the change of the saccharine mat-
ter: but when the juice of the grape has been carefully
freed from it, the fermentation takes place as briskly as in
must not clarified, and we find it pass through all its stages
in the same period, without depositing any thing but tar.
trite of lime.

The true cause of fermentation in juices, whether claris
ficd or not, does not reside in this fecula therefore, but in
the fluid sugar, the only principle of fruits that is truly fers
mentable of itself, and capable of imparting this movement
to solid sugar. Deyeux appears to me to be the first who
observed this difference, and it must be confessed, that all
the phenomena of fermentation tend to confirm his opinion.
Let us take a rapid view of them. ; ;

The first effect of fermentation on a juice that has been
clarified but not saturated is the absorption of thé first pors
tions of carbonic acid, that begins to be evolved. This

product occasions the honied sweetness to be succeeded by

a brisk taste, which, without being spirituous, renders the
must far more pleasant than it was before; and it is in this
state, that children like it so much. ;

The second is the increase of the bulk of the liquor with
a temperature exceeding that of the atmosphere, though
diminished by all the heat the carbonic acid gas carries off,
and the opacity of whey not well clarified.

_At the third period the spirit of wine begins to appear,
and then the presence of this frees the must from its fecula,
and a great. part of its tartar. The gum, extractive matter,
and malic acid subsist amid the fermentation, without tak. .
ing the least part in it, since we find them in the same pro-

If

ON THE SUGAR OF GRAPES. 353

if the wine be filtered when at its greatest degree of opa- Filtering checks
city, its fermentation is perceptibly checked; but it after- ee sag
ward revives, and pursues its course without depositing any again revives,
thing but particles of fecula and pure tartar. This fecula, The fecula.
or second lees of wine, is always loaded with tartar: but
when it has beet copiously washed, we find init all the cha-
racters on which Thenard has insisted, and particularly
those appearances, that have led Berthollet to compare it
with starch. It is perfectly insoluble; grows sour, fer-
ments, and acquires the bad smell of the gluten of wheat;
in a word it becomes cheese. When it is dry it is a litle
transparent, horny, and affords ali the products ef animal.
ized matters. Potash dissolves it, and separates it from the
parts that are purely fibrous. In fine, it is the same thing
as the unciarified must rejects in the first moments of fer-
mentation; and if it do net separate from it at the same
period, it is because its solubility retains it in the liquor,
till the alcohol comes te precipitate it. Other circumstances
confirm the fact, that this fecula is no more necessary to the
transformation of the two sugars into alcohol, than the
former, or than the gum, extractive matter, tartar, &c.
if we take must saturated and clarified with whites of eggs,
fermentation commences in it the uext day. It pursues its
course without depositing any fecula, but tartrite of lime
alone; and without yielding any thing but carbonic acid.

In the space of a month the liquor falls from 17° on the The liquor
areometer to i° or 2°. If we analyse the residuum after iar ae
distillation, we shall find again the gum, malic acid, ex- 3
tractive matter, vinegar, some remains of sugar, and no-
thing more.

' The muscovado brought to 17° by a sufficient quantity Fecula has no-
: : ir p thing to do with
of water ferments completely, changes into wine, and de- ¢. ation.
posits but a few particles of matter. Where then is the
influence of the fecula, the tartar, the acids, and the ex-
tracts? But the best clarified must will no doubt retain a
portion of fecula; and it may be said, that this excites fer-
mentation in the sugar. If this be the case, [ would an-
swer, the fermentation should be weaker in proportion to
the loss of this principle occasioned by the clarification of
the must; but we do not find, that this is at all behind that
Vou. XXI.—SuerLement. 2A which

abt

The fecula al-
tered by fer-
mentation.

Fecula of the
2d stage,

ON .THE SUGAR OF GRAPES.

which retains the whole of its fecula. Hence let as cote
clude, that the fecula is one of those products, which are
not necessary to fermentation, and that one of the first
effects of this change is to free the juices fromit, as it
frees them from the tartar and sulphate: that, if fermen.
tation required some of the other products of vegetation, to
enable it to produce its due effect, if is much more natural
to suppose, that those which their solubility renders injuri-
ous to the sugar would takea part, than an insoluble sub«
stance, which we always find again subsequent as well as
previous to it, and of which not the least traces are to be
found in wine or its products.

he fresh fecula of the grape mixed with a solution of
sugar at 17° is incapable of fermentation, as Berthoilet and.
Thenard have already observed. I have also ascertained
this fact. But if with such a solution of sugar we mix the
same fecula after wine has fermented on it, or after it has
become lees, it will excite a very brisk fermentation in it in
a few hours...

The white and muddy fecula deposited in the second stage
of fermentation does not dissolve in the fermenting liquors 5
it undergoes no decomposition in them; it changes neither

its bulk nor appearance; and there is no trace of it disco-

Does it contain
a principle of
fermentation.

The gluten not
affected by fer-
Mentation.

verable in the wine. Itappears to take no part in the phe-
nomena of fermentation, yet it impresses on crystallizable
sugar the fermentative motion. In this case we see clearly,
that it acts as matter impregnated with a principle which it
transmits. What then is this principle? All that remains
for us is to examine, whether we can divest fecula or lees of
this impregnation, this leaven, which fits them for exciting
fermentation; to.enable us afterward to determine, whether
the lees themselves really possess this property, or whether

_ they act only by virtue of this principle, in which case they

are merely a vehicle. This isa point on which Seguin ap-
pears to be octupied. . |

In several spirituous fermentations, in which I have em-
ployed yeast, or meal, the gluten has always risen to the
top, and adhered in shreds to the mouths of the vessels ;
and I could easily perceive, that it had neither altered its
nature, nor been affected by the changes of the fermenting

medium. |
I have

GN THE SUGAR OF GRAPES. 355

{ have said, that the liquid sugar was fermentable per se. Melasses of the
Melasses from the muscadine grape, separated from its cry- a
stallizable sugar, has not lost the property of fermenting.

Alone and simply dissolved in water, notwithstanding hay-

ing been tortured by a number of evaporations, and treat-
ments with chalk and spirit of wine, and its extractive prins = - -
ciple having acquired an extremely disagreeable acrimony,

it has notwithstanding afforded a strong wine.

I have not yet tried to ferment the crystallizable sugar The crystallized
of the grape, to ascertain whether it be fermentable per se: recites tried
this is a step I mean to take, as soon as [ have a sufficient
quantity ; but lsuspect beforehand, thabit is not any more
than the sugar of the cane.

The tartar is a product of vegetable elaboration, like all Tartar not ne-
those that accompany it in the juice of the grape, but it is eee
not a necessary ingredient of fermentation. If nature had
intended it to concur in its phenomena, she would not have
given it that slight solubility, which occasions its separation
in the beginning, when the sugar would have the most need
of itsinfluence. Glauber was well convinced of this: and
accordingly he recommends the separation of the tartar
from the rob, after diluting it in warm water; ‘‘ for thus,”’
he says, ‘ it will be freed from its acidity, and the wine will
be rendered sweeter.”’ It is surprising that Glauber, whe
had considered the subject so well, did not think of saturat-
ing the must.

The experiments, on which Bullion is desirous of establish- Bullion as-
ing the necessity of tartar, have led him to consequences palpate i
much better calculated to increase the vague ideas respecting
fermentation, of which we have already too many, than to
elucidate its theory. If the tartar contributed to the alter-
ations of the sugar, we must admit, that the part it acts is
purely mechanical, since we find it entire after the formation
of the wine. We cannot avoid surprise at the assertion, that This contro-
must would not ferment without tartar, from one who had daily verted by facts.
before his eyes the fermentation of apples, pears, the sugar.
cane, services, oranges, gooseberries, cherries, and all
kinds of fruit, the juices of which are destitute of tartar ;
as well as that of honey, of sugar assisted by yeast, and of
malted grain. His analyses are not more conclusive. What

2A 2 toe

Tartar added to
the juice of

sour grapes will

not make wine,

or increase the
produce of
Spirite

Price of the
grape muscoe
vwade.

Lime dissolves
im Spirit,

ON THE SUGAR OF GRAPES.

too must be the quality of the grapes, the juice of which
afforded him but four drachms of sugar to the pint? and
this sugar, how could he characterize it as of the same spe-
cies with that of the cane? Farther, on what grounds can
he talk of fermentation, and its produce in spirit, from tri-
als in which we find sugar employed in the proportion of
one pound to fifty quarts of water? The liquorice water,
that children sell by the shell-full, is not poorer stuff.

If it were true, that fermentation caused the tartar to
concur in the production of wine, and even that it could
consume fresh quantities for this purpose, as Bullion asserts,
we ought never toemeet with it in our casks; and the juices
most abundant in tartar, those of the years in which the
grape does not ripen fully, would afford wines most abun-
dant in brandy. If we could believe, that doubling the
guantity of tartar would occasion the produce of spirit to
be half as much more, what better use could we make of
this salt, than adding it to the must in the proportion of
half adrachm to a quart, the dose that he asserts occasioned
his obtaining half as much more brandy?

With regard to the price at which the muscovado of the
grape can be afforded, thirty pounds, under the most un-
favourable circumstances, and making full allowance for
every thing, cost at Madrid 45 reals [20s. 13d.]; but had
every thing been bought at the best hand, and the labora-
tory been a place fitted up for the purpose, the cost would
certainly not have exceeded 30 reals [13s. 53d]: and in
what part of the kingdom of Spain is coarse sugar or even
honey to be bought for a real [5d 3] a pound? Add to this
the tuns of grapes annually wasted in the country. At
Toro, this year, I am told, that the beggars, after being
glutted with grapes that they could not consume, left above
170000 arrobes [about 2125 tuns], or about 50000 ar-
robes [625 tuns} of muscovado. And at Aranda de Duero
2006 cantars [500 galls.| of wine, that could neither be
sold nor consumed, were thrown into the kennels; and
150000 were left in the vineyards.

A fact that should not be omitted is the solution of lime
in spirit, which I believe has not been observed. I distilled
twenty five pints of red wine of la Mancha, adding ahand.

ful

ON THE SUGAR OP GRAPES. 357

ful of quicklime, to obtain at once a product free from the
vinegar, which is always found in the first distillation: but
the brandy came over so strongly imbued with the smell and
taste of the lime, that I was surprised. This spirit in fact
contained lime, as was demonstrated by ail the tests; and
its solution was so far from the effect of some unobserved
circumstances, that, when I redistilled it with a gentle
heat, it rose again with all its disagreeableness, Even now,
after the lapse of three years, the spirit is not altered ; it
precipitates the metallic solutions, and oxalic acid, and re.
stores the blue colour of litmus reddened by anacid. This
solution then is a new point of similitude between the earths
and alkalis. :

I have only to add, that recent trials have taught me no- Purification of

c ° a 5 as the grape juice.
thing more is necessary, to saturate and clarify the juice of
the grape, but to throw some powdered chalk into it, agi-
tate the mixture, and let it,stand till the next day. The fe.
cula and earth will unite; the juice is then to be strained,
boiled, and scummed; and whites of eggs are unnecessary.

Desirous of knowing what degree of boiling down was The least boiled
most favourable for the crystallization, I made five experi- ae he
ments in the following order. Having clarified and satu.
rated some juice, I boiled down cne portion of it so as to
leave but thirty-two hundredth parts of extract; another to
thirty-four hundredths; a third to thirty-five; a fourth to
thirty-six; and a fifth to forty. Of these the last crystal.
lized first, next that of thirty-six, and then that of thirty-
five. Those of thirty-two and thirty-four have not crystal.
lized yet. Hence it is evident, that those sirups, which are
least boiled, are the first to yield their sugar.

Meat-soup contains fifty per cent of a savary extract, Soup.
analogous to the product I have obtained from the fermen.

tation of cheese and gluten. This extract is the condiment,

the perfume, the quintessence of the soup: is that of bones

comparable to it?

¥. Account

Improvernent
in stills.

IMPROVEMENT IN STILLS,

WV

Account of a simple Improvement in the common Still. In
a Leticr from Mr. J. Acron. :

| To Mr. NICHOLSON,
SIR,

I SEND you an outline of an improvement I have added
to my common still and worm tub, which | hare found of
such great utility, that I cannot resist the desire I have of
communicating it. The still holds about nine gallons, and
is used for distilling common water, essential oils, and
water impregnated with them. The tub holds about 36
gallons, and not being near any water, I was accustomed to
have a great dealof trouble in changing that in the tub when
it became hot, which it did very soon after commencin_ the
operation. It was this trouble, that put me to the necessity
of contriving the additional condenser, which, though very
simple, [ have found to answer every purpose I conld wish;
and I can now distil any length of time without the water
in the tub being-scarcely raised a degree in temperature, or
requiring to be changed, as the heat accumulates in the ad.
ditional condenser, and when elevated to about 140° or
150°, passses off by evaporation.

This condenser consists of a trough, a, Plate X, Fig. 1,
three feet long, twelve inches deep, and fifteen inches wide ;
with a pewter pipe, ®, passing through the middle of it, of
about two inches diameter at the largest end, and gradually
tapering to about three quarters of an inch at the smaller
end. It is most likely, that so simple and so useful a con-
trivance must have been thought of before, but never hav.
ing seen or heard of any, I have taken the liberty of troub.
ling you with it, requesting you will exercise your own
judgment as to the propriety of inserting it in your Journal,
as I have so firm a reliance upon the justice of it I cannot
be otherwise than pleased with your decision,

T remain, Dear Sir,
Your obliged and faithful Servant,
Ipswich, J, ACTON.
August 19, 1808,
VI, Description

Nicholsons Philos. Journal, Vol EXT. Pui. p 958.

Pua
io, Abeitiined Cpa of . —Sinae
, = eae Le

HE

THI
WE

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&

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NX
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Qenes

NEW. VARIETY OF CARBONATE OF. LIME, 359

ae

Description of a new Variety of Carbonate of Lime. By
R. J. Havy*.

Iw my Treatise on Mineralogy I described forty-seven de- 71 varieties of
terminate varicties of form in carbonate of lime. Abcut peda: tot
two years after I published in the Annals of the Museum

of Natural History a memoir containing a description of

thirteen more varieties of the same substance, making to-

gether sixty; and since that time I have observed eleven,

equally marked with novelty, so that at present the number

of forms presented by this species amounts to-seventy one.

This number is trifling to what theory demonstrates to be Above 8 mil-
possible, which exceeds eight millions, even supposing we !s Possible,
confine ourselves to the four simplest laws of decrement.

But L am far from considering the formula, that has led me

to this result, as exhibiting the sum of past and future dis.

coveries; and we need not fear being perplexed at some fue but circum-
ture period by our abundance, if we consider, that among ieee
the circumstances capable of determining the production of duction of all
this immense quantity of crystalline forms there are a great 4° Pt
number, that do not existin nature. The formula to which

I allude merely shows us how fertile the laws of the struc-

ture of crystals are in themselves; and teaches us, that

Science has in her hands certain means of determining with

precision all the new forms, that may present themselves to
mineralogists in the course of their researches, however va-

ried they may be, and however little analogy they may bear

- jn appearance to those that are already known. |

The very steps that Science takes in her progress, in prar Only a a
portion as she enriches herself by discovery, indicate, that Se
what does exist is confined to very narrow limits compared re exist.
with what is capable of existing. The new varieties of cars
bonate of lime, that have been found within these few
years, are almost all of them but different combinations of
laws already observed, and the greatest of these combina-
tions does not include above six quantities.

Z

* Journal des Mines, vol. XVIII, p. 299.

360.

Only two-laws
to add to those
before known.

Trihexaedral
carbonate of
lime.

Prismatie hy-
aline quartz.

New variety of:
carbonate of
lime.

Fs ‘figure,

NEW VARIETY OF CARBONATE OF LIME.

In the applications I have made of the theory to these
varieties I have found but two laws to add to the twenty-
one I had mentioned in my treatise as thase, of which I had
then recognised the existence. The first determines in part
the structure of a variety, which I have called trihexae-
dral carbonate of lime, because its figure is that of a six-
sided prism, terminated by right pyramids of the same num-
ber of faces. ‘Three of these faces are parallel to those of
the primitive rhomboid, and the other three, which have
the same inclination, result from a decrement by two rows
in height on the inferior angles e, Fig. 2, Plate X, of the
same rhomboid, so that if this law attained its limits, the
secondary form resulting from it would be similar to the
nucleus. This structure is likewise that of the prismatic
hyaline quartz, which I have described in my Treatise on
Mineralogy, vol. ii, p. 411; but in the quartz crystals the
inclination of the terminal faces to the adjacent sides is
141° 40’, while in the carbonate of lime it is only 135° 5
which arises from the difference that exists between the pri-
mitive forms themselves. JI am indebted to Mr. Heéricart-
Thuri, mine-engineer, for the knowledge of this interest.
ing variety, a specimen of which he has presented to me.

The second law relates ta the variety, that forms the
subject of thisarticle: The crystals, that have enabled me
to determine it, were sent me from Ciermont-Ferrant by
Mr. Augustus Mabru, whose useful researches in the de-
partment of Puy-de-Ddme, as well as those of his worthy
friend Mr. de Laizer, afford new proofs of the mineralogi-
cal treasures contained in that country. I avail myself of
this opportunity, to render them both a public testimony of
my gratitude for their eagerness to impart to me the fruits
ef their discoverics, particularly with respect to the species
sulphate of barytes, of which they have sent me a consi-
derable number of varieties hitherto unknown; and this
pleasure has been greatly enhanced, as the symbols repre-
senting the laws of their structure, given in the letters ac.
companying them, generally announce observers equally
attentive and enlightened. ae

Fig. 3 represents the variety in question. Mr. Mabro
had very justly remarked, that it exhibited a rhomboid with

i : equal

NEW VARIETY OF CARBONATE OF LIME, 361

equal axes, each of the six lower edges of which was re-
placed by a bevel with two facets, s,s”. Hence it follows,
that, if we suppose these facets prolonged till they mect,
so as to conceal the faces g, g, of the equiaxal rhomboid,
the crystal would be a codecaedron with scalene triangles,
analogous to that of the metastatic variety, commonly called
dog-tooth spar; and if we were farther to imagine planes
passing through the edges x, x, &c., these planes would in-
tercept a rhomboid similar to the equiaxal, and which with
respect to the dodecaedron would have the same position, as
the primitive rhomboid has with respect to the metastatic
dodecaedron; so that the equiaxal rhomboid may be consi-
dered as a hypothetical nucleus with respect to the dodeca-
edron before us. We have already an instance of a hypo-
thetical nucleus of the same kind in the paradoxa] carbonate
of lime discovered by the learned Mr. Tonnellier, keeper
of the mineralogical collections of the Council of Mines.
But in the latter variety the hypothetical nucleus is the in-
verse rhomboid; and it is remarkable, that the forms hi-
therto exhibited by these sorts of hypotheses are engrafted,
as it were, on the two secondary rhomboids, the most sim-
ple among those that belong to carbonate of lime.

It was easy to see at once, that the facets s, s”, must de. and structure.’
pend on a law intermediate to the angles E E of the nucleus,
Fig. 2, which is likewise the case with the paradoxal variety.
Now in this there are two lines of particles subtracted from
the edges D D, and only one from the edges BB, which is
the most simple of combinations of this kind: and if we
add the condition, that the hypothetical nucleus is the in-
verse rhomboid, it necessarily follows, that the intermediate
decrement takes place with a single row. In the varicty
discovered by Mr. Mabru the two terms of combination are’
greater by unity than in the preceding, that is, there are
three lines of particles subtracted from the edges D D, and
two from the edges BB; and combining these data with the
condition, that the hypothetical nucleus is the equiaxal
rhomboid, we find, that the intermediate decrement is at
the same time mixed, and takes place by five rows in breadth
and six in height. Any other law would give for the nu-
cleus a rhomboid different from the equiaxal. For instance,

if

862 : NEW VARIETY OF CARBONATE OF LIME,

if we suppose the intermediate decrement to be made by a
single row, the hypothetical nucleus would become a rhom-
boid extremely flattened, in which the great angle of the
rhombus would be 119° instead of 114° 18’, and the great.
est angle of incidence between the faces 160° 26’ instead of
134° 23': and besides, on this supposition the values of the
angles of the dodecaedron would differ very sensibly from
those that give the law of 3, which agree with observation.

Measures of its The following are the measures of the saliant angles.

angles. Between g and g, 134° 23’ 38”; s and s’, 118° 29’ 4”:
sand g, or sand g’, 143° 32’ 39”; s ands, 115° 1/ 44’;
s ands’, 142° 24’ 6”. )

Numerical ear- [ give this variety the name of numerical carbonate of -

ponat. of lime. lime, on account of the properties of the numbers that ex-

press its form; the sum of the exponent of B, which is 2,
and of the exponent of D, which is 3, being equal to the
nuniera¢or of the exponent of EH, which is 5, and their
product being equal to its denominator, 6.

I have likewise investigated the law that would govern
the dodecaedron, if the hypothetical nacleus were substi-

tuted for the true; and I have found, that in this case the
: 5

symbol of the dodecaedron would be pe? a quantity the
exponent of which is double that of H in the preceding
case. _ ?
Possibility of In my Treatise on Mineralogy, vol. ii, p. 15 and follow-
substituting a ing, I have developed the theory respecting the possibility
secondary form eth Paid
to the primitive of thus substituting a secondary form to the primitive ono,
ya so as to derive any other secondary form from it by the laws

of decrement. ‘This view gives an infinite scope, if J may.

be allowed the expression, to the results of that branch of
geometry, which arises from the study of the laws, to which
the wisdom and power of the supreme Being has subjected
the formation of the regular bodies, that people the subter-
ranean world; and our admiration increases, when we sce
this immensity of results end in one common term, the in-
variable form of the particle shawn by the dissection of cry-
This variety Stals. I ought to say here in particular, that none of the
easily dissected. yaricties of carbonate of lime exhibit the rhomboid of
101° 30’ by the help of mechanical division with more fa-
cility, and more neatly, than that which has been described ,

Mr.

ioe g

= PE Ear gee

ON THE NEW METALS, 363

Mr: Mabru found this variety at the foot of Puy-Saint. Where found.

Romain, below the plaster quarries of St. Maurice, about

ten miles south-east of Clermont, in the department of
Puy-de-Dome. Its gangue is a compact carbonate of lime

of a gray colour, mixed with a little argile and oxide of

iron. The largest crystals I have observed, are about

18 mill., or 8 lines [7 lines Eng.] broad. In the same place Size.

is found equiaxal carbonate of lime without any modifi.

cation.

EE
Vil.

Second Letter on the Subject of the New Metals.
By Mr. A. Comses.

To Mr. NICHOLSON.
SIR,

As you have tandidly admitted a letter into your Journal, The question
in which your own statements (as it seems) are censured, eal Secs
you will not, I trust, refuse a place to my reply to your ments.
observations *. It may be considered as presumption in an

obscure individual, to enter into the lists with a veteran in

science; and this would be the case, were the question of

_any other nature than merely concerning historical docu-

ments; upon these topics the mere man of leisure may have

an advantage over the man of business and genius; and to

refer to authorities requires no great intellectual exertion.

I still maintain, in opposition to your opinion, for which Fourcroy’s tes-
on all other occasions I have the highest respect, that the eee Gyhinen
true alkalis ‘‘ were never long ago suspected to be metallic
oxides.”

You mention the testimony of Fourcroy, but the passage _
to which you refer is undoubtedly equivocal.

Mr. Fourcroy says, Systeme des Con. Chem. IT, pag. 196,
¢ opinion sur la pretendue nature mefalligue de la Barite
ainsi que celle des autres bases salifiables surtout terreuses
ne sera qwune hypothese.” Here ‘* des autres” ought,

* See Journal, p. 231—4.
in

364

Mr. Kerr's not
a guess,

Tondi and Ru-
precht’s expe-
riments,

Bir. Kerr.

Kren the

ON THE NEW METALS.

n strict grammatical propriety to be translated ** others,”
and not the other. And Fourcroy throughout his work
never hints at any suspicion of soda, potash, and ammonia
being metallic.

You have quoted Mr. Kerr, but what he has said is not
a suspicion or guess, but a statement of facts, which for
many years have been known to be false, and which he has
never condescended to correct. Magnesia, according to
him, had been proved by Tondi and Ruprecht to be a mMe-
tallic oxide. Soda, he says, appears from some experi-
ments published in the Turin Transactions, to be a modifi-
cation of magnesia, therefore soda must be also a metallic
substance. Now here are no analogies brought: forward,
nothing which can be called an hypothesis, but a mere plain
downright statement of an errour.

I am a litile surprised at the view which you yourself
have taken of Tondi’s and Ruprecht’s experiments. You
state, that alkali was certainly present, but that the alloys
were like phosphurets of iron. You do not refer to what
the sagacious Klaproth has said after a minute examination
of these results, Annales de Chimie, IX, page 287. ** The
pretended reduction of earths into metals, is nothing buta
pure illusion; nor do you notice, that Savaresi, by a
most elaborate and elegant series of experiments, proved,
‘¢ that they could be produced or not at pleasure, not in
consequence of the presence or absence of alkali, or
alkaline earths, but in consequence of the presence or
absence of bone ashes.”” Annales de Chimie, IX, page
156. .
You certainly may find one authority, showing that al-
most every ‘¢ thing is metallic,’? deduced from the very
book which you have already quoted ;” for Mr. Kerr is
disposed to place charcoal, phosphorus, and sulphur,
amongst the metals, for the very reasons why they ought
to be excluded from this class of bodies. He says, ‘* why
should carbon, sulphur, and phosphorus, not be con-
sidered as metals, because their specific gravity, lustre, and
ductility, differ from the bodies called metals, which differ
so much in these respects amongst themselves?”

There are no persons in general more.ready to lay claim

to

‘ON THE NEW METALS. 365

to the foundations of a discovery, if not to the discovery nak admit
itself, than our neighbours on the continent, yet on this cg es
occasion they have been anticipated at home: for.in a report discovery.
of the Polytechnic School, published in the last Number of

the Phil. Magazine, it is said by the editors of the journal

of the Polytechnic School, ‘ that Mr. Gay Lussac, and

Mr. Thenard, had repeated Mr. Davy’s experiments, and

obtained the two new metals, of which the existence had

not been suspected previous to Mr. Davy’s experiments.”’

You say, it is no derogation to Mr. Davy’s merits, that Mr. Davy’s
he has explored the processes of nature by simplicity of in- “°°V°"Y
vestigation, and clear deductions grounded upon a know-
ledge of the antecedent analogies. On the last part of this
proposition I cannot agree with you. It would in my
opinion have been a derogation to his merit, had he been
guided by any analogies so loose as those, whieh might have
Ted him to look for metals in the fixed alkalis. He was on
the contrary enlightened by new principles of research,
arising from the knowledge of the properties of chemical]
decompesition by Voltaic electricity, which your useful
Jabours partly led the way to, and which his discoveries
have made almost universal.

I attended his course of lectures of 1807, and in referring The negative
to my notes I find, that he stated it as a fact, that all bodies os ae
ef known composition attracted by the negative pole in the ble matter.
Voltaic circuit consisted principally of inflammable matter,
and were naturally positive; and that it was probable there.

_ fore, that all bodies of unknown composition attracted by

this pole, and which were naturally positive, might also

- contain inflammable matter.

_ inflammable matter after those ideas in the fixed alkalis,

In his lectures in 1801, he stated, that, in looking for This he lookog
forin alkalls.
he had discovered it, and that he had likewise found what
he had not expected, that it was metallic in its nature.
In this instance sagacious conjecture and sound analogy

_ were followed up by experimental research, and ended in

ba great discovery.

Guesses, except from experimental ingquirers, ought Guesses ia
. . . science
scarcely to be tolerated in science; and to attach import-

ance to them, and to dignify them with approbation, is

merely

366

Decomposition
of the fixed al-
kalis led to

ON THE DECOMPOSITION OF THE EARTHS.

merely to encourage a waste of time and a tendency to
dreaming. Mere barren hypothesis, that neither arise from
facts, nor lead to experiments, are weeds in the field of
science which will always grow sufiiciently without manures

You, 2s an experimental poilosopher and a lover of
truth, ought to endeavour to check their growth; and
should your Journal be made a hotbed for their cultivas
tion, it must inevitably loose its ancient universally ace
knowledged utility and importance.

I am, Sir,
Your obedient humble Servant, |

A. COMBES.
Chelseu,
Nowember 17, 1808.

VIII.

Electro-Chemical Researches, on the Decomposition of the
Earths ; with Observations on the Metals obtained from
the alkaline Earths, and on the Amalgam procured from —
Ammonia. By Uumenry Davy, Esq. Sec. R. Si
DMs Tee hi a *

1. Introduction.

Iw the Philosophical Transactions for 1807, Part I +, and
1808, Part I, I have detailed the general methods of decom.
position by electricity, and stated various new facts obtained
in consequence of the application of them. i

The results of the experiments on potash and soda, as I a

stated in my last communication to the Society, afforded me —

hopes of similar the strongest hopes of being able to effect the decomposi-

results.

tion both of the alkaline and common earths; andthe phe-
nomena obtained in the first imperfect trials madeupon these _

bodies countenanced the ideas, that had obtained from the

* Philosophical Transactions for 1808, Part II, p. 333.

+ See Journal, vol. XVIII, p.321, aud XIX, p. 37.

$ Ibid. Vol. XX, p. 290, 321, P|
earliest

ON THE DECOMPOSITION OF’ THE EARTHS. - 367

earliest periods of chemistry, of their being metallic in their
nature *, .

Many difficulties however occurred in the way of obtain- Many difficul-
ing complete evidence on this subject: and the pursuit of 8 eccuted-
the inquiry has required much labour, and a considerable
devotion of time, and has demanded more refined\and com.
plicated processes, than those which had succeeded with the
fixed alkalis.

* Beccher is the first chemist, as far as my reading informs me, Early notions
whe distinctly pointed out the relations of metals to earthy sub- of the metallic
Ae nature of

stances, see Phys. subt. Lipsie, 4to, p. 61. He was followed by giiths.

Stahl, who has given the doctrine a more perfect form. Beccher’s

idea was that of a universal elementary earth, which, by uniting

- to an inflammable earth, produced all the metals, and under other

modifications formed stones. Stahl admitted distinct earths, which

he supposed might be converted into metals by combining with

phlogiston ; see Stahl Fundament. Chym. p. 9, 4to, and Conspect.

Chem. 1, 77, 4to.—Neuman gives an account of an elaborate

series of unsuccessful experiments which he made to obtain a metal

from quicklime. Lewis’s Neuman’s. Chem. Works, 2d. edit,

yol.i, p. 15. The earlier English chemical philosophers seem to

have adopted the opinion of the possibility of the production of

metals from common earthy substances; see Boyle, vol. i, 4to, p.

564, and Grew, Anatomy of Plants, lec. ii, p. 242. But these

notions were founded upen a kind of alchemical hypothesis of a

general power in nature of transmuting one species of matter

into another. Towards the end of the last century the doc-

trine was advanced in amore philosophical form; Bergman sus-

pected barytes to be a metallic calx, Pref. Sciagrap. Reg. Min.

and Opusc. iv, 212. Baron supported the idea of the probability of

alumine being a metallic substance, see Annales de Chemie, vol. x,

p. 257.—Lavoisier extended these notions, by supposing the other

earths metallic oxides. EJements, 2d edit. Kerr’s translation,

p- 217. The general inquiry was closed by the assertion of Tondi

and Ruprecht, that the earths might be reduced by charcoal; and

the accurate researches of Klaproth and Savaresi, who proved by

the most decisive experiments, that the metals taken for the bases

Of the earths were phosphurets of iron, obtained from the bone

ashes and other materials employed in the experiment, Annales de

Chemie, vol. viii, p. 18, and vol. x, p. 257, 275. Amidst all

these hypotheses, potash and soda were never considered as metallic

in their nature; Lavoisier supposed them to contain azote; nor at

that time were there any analogies, to lead that acute philosophec

to a happier conjecture.
: 5 The

368 ON THE DECOMFOSITION OF THE EARTHS.

sos the in The earths like the fixed alkalis are nouconductors of
fusibility of the electricity ; but the fixed alkalis become conducting by fu-«
oe sion: the infusible nature of the earths, however, retidered
it impossible to operate upon them in this state: the strong
affinity of their bases for oxigen, made it unavailing, to act |
: upon them in solution in water; and the only methods, that
proved successful, were those of operating upon them by
electricity in some of their combinations, or of combihing
them at the moment of their decomposition by electricity in |
tmmetallic alloys, so as to obtain evidences of their nature
and properties. |
A more power- I delayed for some time laying an account of many of the :
2 br ag principal results which I obtained before the Society, in the j
: hopes of being able to render them more distinct and satise
factory ; but finding that for this end a more powerful bat~ |
tery, and more perfect apparatus than I have a prospectef
seeing very soon constructed, will be required, 1 have ven=
tured to bring forwards the investigation in its present im.
perfect state; and I shall prefer the imputation of having
published unfinished Jabours, to that of having concealed
any new facts from the scientific world, which may tend iy ss
assist the progress of chemical knowledge. shee: al

2. Methods employed for decomposing the alkaline Earths.

The alkaline Barytes, strontites, and lime, slightly moistened, were

earths moisten- electrified by iron wires under naphtha, by the same me-
ed, and electri-

Fok siaclesy thods, and with the same powers as those employed for the
naphtha. decomposition * of the fixed alkalis. In these cases, gas was
Inflammable

gas evolved, copiously evolved, which was inflammable; and the earths,
and. metallic where in contact with the negative metallic wires, became
i appcr dark coloured, and exhibited small points having a metallic
lustre, which, when exposed to air, gradually became
white; they became white likewise when plunged under
water, and when examined in this experiment by a magnifier,
a greenish powder seemed to separate from them, and smali

globules of gas were disengaged.
In these cases there was great reason to believe, that the
earths had been decomposed; and that their bases had com-

* See page 4, or Journal, vol. xx, p- 291.. 4
bined

ON THE DECOMPOSITION OF THE EARTHS. 369

dined with the iron, so as'to form alloys decomposible by
the oxigen of air or water; but the indistinctness of the ef
fect, and the complicated circumstances required for it,
were such as to compel me to form other plans of operation:

The strong attraction of potassium for oxigen induced Potassium tried
“te to try whether this body might not detach the oxigen siisen
from the earths, in the same manner as charcoal decom- the earths.
poses the common metallic oxides.

I heated potassium in contact with dry pure lime, barytes, Ineffectual.
strontites, and magnesia, in tubes of plate glass; but as L
_ ‘was obliged to use very small quantities, and as I could not
raise the heat to ignition without fusing the glass, I ob.

tained in this way no’ good results. The potassium ap-
peared to act upon the earths and on the glass, and dark

_ brown substances were obtained, which evolved gas from
water ; but no distinct metallic globules could be procured:
from eke circumstances, and other like circumstances, it
seemed probable, that though potassium may partially de-
oxigenate the earths, yet its affinity for oxigen, at least at
the temperature which I employed, is not sufficient to Bassi ye

pied decomposition.

Ianade mixtures of dry potash in excess and dry barytes, Potash and the
time, strontites, aud magnesia, brought them into Piston or an allen,
and acted upon them in the voltaic circuit in the same man-
ner as:that I employed for obtaining the metals of the
alkalis. My hopes were, that the potassium and the
netals of the earths might be deoxigenated at the same
ime, and enter into combination in alloy.

It ‘this way of opcrating, the results were more distinct The results
: than in the last: metallic substances appeared, less fusible co
than poiassium, which burnt the instant after they had

formed, and which by burning produced a mixture of

potash and the earth employed; I endeavoured to form

them under naphtha, but without mach success. To pro-

duce’ the result at all required a charge by the action of

nitric acid, which the state of the batteries did not permit

me often to employ*; and the metal was generated only in

very

* The power of this combination, though it consisted of one The Voltaic
. - hundred -plates of copper and zine of six inches, and one hundred ene

| Vor. XXI.—Suppcemenr. 2B | alae ain

ae,

370 : ON THE DECOMPOSITION OF THE EARTHS.

very minute films, which could not be detached hy fusion,
and which were instantly destroyed by exposure to air.
As potash I had found in my researches upon potassium, that when
“perleeer ‘des 2 mixture of potash and the oxide of mercury, tin, or
was rapidly de- lead, was electrified in the Voltaic circuit, the decomposi-
composes, tion was very rapid, and an amalgam, or an alloy of potas-
sium was obtained; the attraction between the common
metals and the potassium apparently accelerating the sepa
ration of the oxigen.
the earths were The idea that asimilar kind of action might assist the de~
ca ie composition of the alkaline earths induced me, to‘ electrify
mixtures of these bodies and the oxide of tin, of iron, of
lead, of silver, and of mercury; and these operations were
far more satisfactory than any of the others. ©
Barytes 2 ps A mixture of two thirds of barytes and one third of
Key ofsilver oxide of silver very slightly moistened was electrified by iron
wires ; an effervescence took place at both points of con.
tact, and a minute quantity of a substance, possessing the
whiteness of silver, formed at the negative point. When
the iron wire to which this substance adhered was plunged
into water containing a little alum in solution, gas was dis-
engaged, which proved to be hidrogen; and white clouds,
which were found to be sulphate of barytes, descended
from the point of the wire.

Barytes and A mixture of barytes and red oxide of mercury, in the
red oxide of > :
mercury. “ok all

and fifty of four inches, at this time was not more than equal to

Theatre of the Royal Institution in 1803; and since that time had
been constantly employed in the annual courses of lectures, and
had served, in different parts, for the numerous experiments on the
decomposition of bodies by electricity, detailed in the Bakeriaa
Lectures for 1806 and 1807, and a number of the plates were
destroyed by corrosion. I mention these circumstances, because
_ many chemists have been deterred from pursuing experiments on
the decomposition of the alkalis and the earths, under the idea that
a very powerful combination was required for the effect. This,
however, is far from being the case; all the experiments detailed
in the text may be repeated by means of a Voltaic battery, con-
taining from one hundred to.one hundred and fifty plates of four

‘er six inches.
same

that of a newly constructed apparatus of one hundred and fifty of
four inches. It had been made for the demonstrations in the —

ON THE DECOMPOSITION OF THE EARTHS. S71

same: proportions, was electrified in the same manner. A
small mass of solid anaigan, adhered to the negative wire,
which evidently contained’ a substance, @@hat produced
barytes by exposure to air, with the absorplion of oxigen;
and which occasioned the evolution of hidrogen from water,
leaving pure mercury, and producing a solution of barytes.

Mixtures of lime, strontites, magnesia, and red oxide of ie serontay
Mercury, treated in the same manner, gave similar amal- sole i dl
gams, from which the alkaline earths were regenerated by oxide.
the action of air or water, with like phenomena; but the
quantities of metallic substances obfained were exceedingly
minute; they appeared as mere superficial formations sur-
rounding the point of the wire, nor did they increase after
_ the first few minutes of electrization, even when the process

‘was carried on for some hours.

These experiments were made previous to April, 1808, te new battety

at which time the batteries were so much injured by con-— nicl
stant use, as no longer to form an efficient combination.
The inquiry was suspended for a short time: but in May I
was enabled to resume it, by employing a new and much
more powerful combination, constructed in the Laboratory
of the Royal Institution, and consisting of five hundred
pairs of double plates of six inches square.

When I attempted to obtain amalgams with this appa-
ratus, the transmitting wires being of platina, of about 3’,
of an inch in diameter; the heat generated was so great as.

_ to burn both the mercury and basis of the amalgam at the
moment of its formation; and when, by extending the sur- —
faces of the conductors, this power of ignition was modified,
t still the amalgam was only produced in thin films, and
are not obtain globules sufficiently large to submit to
distillation. When the transmitting wires were of iron of
the same thickness, the iron acquired the temperature of
ignition, and combined with the bases of the earths in pre-
ference to the mercury, and metallic alloys of a dark gray
colour were obtained, which acted on water with the evolu-
tion of hidrogen, and were converted into oxide of iron,
and alkaline earths.
~ While I was engaged in these experiments, in the be- Pomtin and
ginning of June, I received a letter from Professor Ber- tively electrified
2B2 zelius meréury incon-

312

tact with ba-
rytes and lime.

This repeated
with success. |

The same tried
with strontia
and magnesia.

The amalg
might be pi
served some
time under
maphtha.

Sulphate of

ap
ON THE DECOMPOSITION OF THE EARTHS,

zelius of Stockholm, in which he informed me, that, it
conjunction wih Dr. Pontin, ghe had succeeded in decom-
posing barytes™#nd lime, by negatively electrifying mercury »
in contact with them, and that in this way he had obtained
amalgams of the metals of these earths.

I immediately repated these operations with perfect suc-
cess; a globule of mereury, electrified by the power of the —
bat@ry of 500, weakly €harged, was made to act upon a
surface of slightly moistened barytes, fixed upon a plate of
platina. The mercury gradually became Jess fluid, and
after a few minutes was found covered with a white film of
barytes; and when the amalgam was threwn into water,
hidrogen was disengaged, the mercury remained free, and
a solution of barytes was formed.

The result with lime, as these gentlemen had stated, was
precisely analogous. \

That the same happy methods must succeed with pce
tites and magnesia, it was not easy to doubt, pe I quickly
tried the experiment.

From strontites I obtained a very rapid result; ‘bat from
magnesia, in the first trials, no amalgam could be procured.
By continuing the process however for a longer time, and
keeping the earth continually moist, at last a combinatiote
of the basis with mercury was obtained, which slowly pro-
duced magnesia by ssi Ba of oxigen from. air, or by the
action of water. ;

All these amalgams I found nile be preserved for a con-

siderable period under naphtha. Ina length of time, how-
ever, they became covered with a white crust under this
fluid. When exposed to air, a very few minutes only were

required for the oxigenatiOn of the bases of the earths. In
water the amalgam of barytes was most rapidly decom.
posed: that of strontites and that of lime next in order:
but the amalgam from magnesia, as might be expected from
the weak affinity of the earth for water, very slowly
changed ; when a little sulphuric acid was added to the
water, however, the evolution of hidrogen, and the pro-
duction and solution of magnesia were exceedingly rapid,

and the mercury soon remained free,

I was inclined to believe, that one reason why magnesia
; was

on @ DECOMPOSITION OF THE EARTHS. ais

‘was less easy to metallize than the @her alkaline earths magnesia
was its insolubility in water, which would prevent it from i paar a
being presented in the nascent state, detached from itsso.
jution at the negative surface. On this idea I tried the ex-
periment, using moistened sulphate of magnesia, instead of
the pure earth; and J found tliat the amalgam was much
sooner obtained. Here the magnesia was attracted from the
sulphuric acid, and probably deoxigenated and combined
‘with the quicksilver at the same instant.
The amalgams of the other bases of the alkaline earths Salts of the
‘could, I found, be obtained in the same manner from their pasta ig
_ saline compounds.
I tried in this way very successfully muriate and sul-
‘phate of lime, the muriate of strontites and of barytes,
and nitrate of barytes. The earths, separated at the de-
_oxigenating surface, there seemed instantly to undergo de.
‘composition, and, seized upon by the mercury, were in
some measure defetiged from the action of air, and from the
contact of water, and preserved by their seh attraction
— for this metal.

Wn. aittompts to procure the Metals of the alkaline Earths;

and on their Properties. Poy

'» To procure quantities of amalgams sufficient for distilla- Trial to procure
icin I combined the methods I had before employed, with ae
those of Messrs Berzeliug.and Pontin. . ) quantities.

. The earths were slig moistened, and mixed with on
‘third of: red oxide of mercury; the mixture was placed on eB
«plate of platina ;,a cavity was made in the upper part of it
ito receive a globule of mercury, of from 50 to 60 grains
in the weight, the whole was covered by a film of naphtha,
sand the plate was made positive, and the mercury negative,
by @ proper communication with the battery of five hundred.

_ The amalgams obtained in this way were distilled in twbes The amalgams
cof plate glass, or in some cases in tubes ef common glass. nee
These tubes were bent in the middle, and the extremities
were enlarged, and rendered globular by blowing, so as to
serve the purposes of a retort and receiver.

_ The tube, after the amalgam had been introduced, was
filled with’ naphtha, which was afterward expelled by
boiling,

. a i
374 ON THE DECOMPOSITION OF THE Brus.

boiling, through a small orifice in the end corresponding to
the receiver, which was hermetically sealed when the tube
contained nothing but the vapour of naphtha, and the
amalgam.

Part of the I found immediately, that the mercury rose pure by dis«

mercury easily tillation from theamalgam, and it was very easy to separate

distilled off, og
a part of it; but to obtain a complete ee eemaineiui was
very difficult.

but the whole or this nearly a red heat was required, and at a red binet

only with great the bases of the earths instantly acted upon the glass, and

ana became oxigenated, When the tube was large in proportion
to the quantity of amalgam, the vapour of the naphtha fur-
nished oxigen sufficient to destroy part of the bases; and
when a small tube was employed, it was difficult to heat the
part used as a retort sufficient to drive off the whole of the
mercury from thebasis, without raising too highly the tem-
perature of the part serving for the receiver, so as to barst
the tube *. =

¥f at all. In consequence of these difficulties, in a multitude of tri.
als, I obtained only a very few successful results, and in no
case could I be absolutely certain, that there was not a mi-
nute portion f merc ury still in combination with the me-
tals of the orths.

Base of bary- In the best result that I obtained from the distillation of

tes. the amalgam of barytes, the residuum appeared as a white
metal of the colour of silver. It was fixed at all common
temperatures, but became fluid heat below redness, and

‘did not rise in vapour when heated to redness, in a ‘tube of
plate glass, but acted violently: npon the glass, producing a
black mass, which seemed to contain barytes, and a fixed
alkaline basis, in the first degree of oxigenation t,
. When
'* When the quantity of the amalgam was about fifty or sixty
grains, I found that the tube could’not be conveniently less than
one sixth of an inch in diameter, and of the capacity of ‘about
half. a cubie inch.

icles atlatn + From this fact, compared with other facts that have pi
earths probably Stated, p. 369, it may be conjectured, that the basis of barytes has
the most pow- a higher affinity for oxigen than sodium; and hence probably the
aoe ‘bases of the earths will be more powerful instruments for detecting

gon. oxigen, than the bases of the alkalis,
} have

ON THE DECOMPOSITION OF THE EARTHS. Bhs ¥

When exposed to air, it rapidly tarnished, and fell into a
white powder, which was barytes. When this process was
conducted in a small portion of air, the oxigen was found

absorbed,

I —_ tried a number of experiments on the action of potassium Base of potash
on bodies supposed ‘simple -and on the undecormpounded acids. @PPlied to
From the affinity of the metal for oxigen, and of the acid for the
substance formed, I had entertained the greatest hopes of success.
HL would be inconsistent with the object of this paper to enter into a
full detail of the methods of operation; I hope to be able to state
them fully to the Society at a future time, when they shall be elu-
cidated by farther researches ; I shall now merely mention the ge-

_Reral results, to show that I have not been tardy in employing the
means which were in my power, towards'effecting these important
objects,

When potassium was heated in muriatic acid gas, as dry as it muriatic acid
could be obtained by common chemical means, there was a violent £4°s
chemical action with ignition; and when the potassium was in suf-
ficienc quantity, the muriatic acid gas wholly disappeared, and from

one third to one fourth of its ene of hidrogen was evolved, and
. muriate of potash was formed.

On fluoric acid gas, which had been in contact with glass, the Auoric acid gas,
potassium produced a similar effect; but the quantity of hidrogen
generated was only one sixth or one seventh of the volume of gas,
and a white mass was formed, which principally consisted of fiuate
of potash andsilex, but which emitted fumes of fluoric acid when
exposed to air.

When boracic acid, prepared in the usual manner, that had been and boracie
ignited, was heated in a gold tube with potassium, a very minute2eid.

-qitantity of gas only was liberated, which was hidrogen, mixed with. :
‘nitrogen, (the last probably from the common air in the tube); bo-
rate of potash was formed, and a black substance, which became

_ white by exposure to air.

In all these instances there is great reason to believe that the hi- The results no t
drogen was produced from the water adhering to the acids; and the conclusive.
different proportions of it in the different cases are a strong proof
of this opinion. Admitting this idea, it seems, that muriatic acid
“gas must contain at least one eighth or one tenth of its weight of

water; and that the water oxigenates in the experiment a quantity
pf potassium, sufficient to absorb the whole of the acid.

In the cases of fluoric and boracic acids, there is probably a de-

3 composition of these bodies ; the black substance produced from
the boracic acid is similar to ‘that which I had obtained from it by

electricity. The quantities that I have operated upon have been ds
mena. yet

376

Base of stron-
tide

Base of lime.

Base of mag-
nesia.

ON THE DECOMPOSITION OF THE EARTHS.

absorbed, and the nitrogen unaltered; when a portion-of it
was introduced into water, it acted upon it with great vio-
lence and sunk to the bottom, producing in. it barytes; and
hidrogen was generated, The quantitics in which I obtained
it were too minute for me to be able to. examine correctly
either its physical or chemical properties. It sunk rapidly
in water, and even in sulphuric acid, though surrounded by
globules of hidrogen, equal to two or three times its vo-
lume; from which it seems probable, that it cannot be less
than four or five times as heavy as water. It flattened by
pressure, but required a considerable force for this effect.

- The metal from strontites sunk in sulphuric acid, and ex.
hibited the same characters as that from barytes, nani
producing strontites by oxidation.

‘The metal from lime I haye never been able to examine
exposed to airor under naphtha. In the case in which I was
able to distil the quicksilver from it to the greatest extent, the
tube unfortunately broke, while warm, and at the moment
that the air entered, the metal, which had the colour and

lustre of silver, instantly took fire, and burnt with an in.

tense white light into quicklime.
The metal from magnesia seemed to act upon the glass,

even before the whole of the quicksilver was distilled from -

it. In an exper iment in which I stopped the process before
the mercury was entirely driven off, it appeared as a solid,
having the same whiteness and lustre as the other metals of

yet too small, to enable me to separate and examine the products,
and till this is done, no ultimate conclusion can be drawn.

The action of potassium upon muriatic acid gas indicates a much
larger quantity of water in this substance, than the action of elec-

tricity in Dr. Henry’s elaborate experiments; but in the one instance

the acid enters into a solid salt, and in the other it remains aeri-
form; and the difficulty of decomposition by electricity must in-
crease in proportion as the quantity of water diminishes, so that at
the apparent maximum of electrical effect, there is no reason to.
suppose the gas free from water.

Those persons who have supposed hidrogen to be the basis of
muriatic acid may, perhaps, give another solution of the pheno-
mena, and consider the experiment I have detailed as a proof of
this opinion.

the.

:

eS ee

~

a ”)

ON THE DECOMPOSITION OF THE EARTHS.

the earths. It sunk rapidly in water, though surrounded
by globules of gas producing magnesia, and quickly changed
in air, becoming covered with a white crust, and falling into
a fine powder, which proved to be magnesia.

3T7

In several cases in which amalgams of the metals of the Amalgams of

earths, containing only a small quantity of mercury, were
obtained, I exposed them to air on a delicate balance, and
always found, that, during the conversion of metal into earth,
there was a considerable increase of weight. ;

the metals of
the earths.

. I endeavoured to ascertain the proportions of oxigen and Attempts to

ascertain the

basis in barytes and strontites, by heating amalgams of them proportion of

in tubes filled with oxigen, but without success. I satisfied base-

mnyself, however, that when the metals of the earths were
burned in a small quantity of air they absorbed oxigen,
gained weight in the process, and were in the highly caustic
or unslacked state; for they produced strong heat by the
contact of water, and did not effervesce during their solu-
tion in acids.. ;

The evidence for the compostion of the alkaline earths is
. then of the same kind as that for the composition of the com.
mon metallic oxides; and the principles of their decomposi-
~ tion are precisely similar, the inflammable matters in all cases
separating at the negative surface in the Voltaic circuit, and
the oxigen at the positive surface.

' These new substances will demand names ; and on the same New names,

principles as I have named the bases of the fixed alkalis
potassium and sodium, I shall venture to denominate the
metals from the alkaline earths barium, strontium, calcium,
and magnium; the last of these words is undoubtedly ob-
jectionable, but magnesium * has been already applied to
metallic manganese, and would consequently have been an
equivocal term.

AV. Inquiries relative to the Decomposition of Alumine,
. Silex, Zircone, and Glucine.

I tried the methods of electrization and combination with Alumine and

’ quicksilver, and the common metals, by which I had suc.

* Bergman. Opusc, tom. ii, p. 200.
silex;

silex tried’as
3 ; \ the other
ceeded in decomposing the alkaline earths, on alumine and earths,

a)
=~
ie 8)

ON THE DECOMPOSITION OF THE EARTHY.

Silex; but without gaining distinct evidences of their having
undergone any change in the processes.

‘ Obliged to seek for other means of acting upon ere rt
was necessary to consider minutely their relations to other
bodies, and to search for analogies, by which the principles
of research might be guided.

_ Nearly indif- Alumine very slowly finds its point of rest at the negative
cs satlaesd pole, in the electrical circuit; but silex, even when diffused
ties. in its gelatinous state through water, rests indifferently at

- the negative or positive poles.
Aialeions its From this indifference to positive and negative puree

sigma neu-. attractions, following the general order of facts, it might be
pielnadias inferred, that if these bodies be compounds, the electrical
orsaturated energies of their elements are nearly in equilibrium ; and that
oxides. theirstate is either analogous to that of insoluble neutral aaliny
or of oxides nearly saturated with oxigen.
The combinations of silex and alumine with acids and al.
Kalis, as wellas their electrical powers, were not inconsistent
with either of these ideas; for in some respects they resem-
ble in physical characters fluate and phosphate of Jime, as
much as in others they approach to the oxides of zinc and
tin. H)
Experiments to On the idea that silex might be an iasoldlite sedieendios
apeaentlei compound, containing an unknown aeid or earth, or both,
and capable of being resolved into its secondary elements,
in the same manner as sulphate of barytes, or flnate of lime,
I made the following experiments.
Exposed to Two gold cones*, connected by moistened amianthus,
electricity in were filled with pure water, and placed in the electrical cir.
ere cuit, a small quantity of carefully prepared and well washed
silex was introduced into the positive cone; the action was
kept up from a battery of two hundred plates, for some
hours, till nearly half of the fluid in each cone was ex-
hausted; the remainders were examined; the fluid in the
One vessel acid, Cone containing the silex was strongly acid: that in the op-
the other alka- posite cone was strongly alkaline; the two fluids were
ge cd passed through hibulous paper, and mixed together, when a
precipitate fell down, which proved to be silex.

* The same. as those deseribed in Phil. Trans, 1807, p. 63. or
Journal, vol. xvili, p. 325.
On

BN THE DECOMPOSITION OF THE EARTHS. 8379

On the first view of the subject, it appeared probable, that It might be sup-
this silex had been formed by the-union of the acid and the a Mg ge
alkaline matter in the two cones, and that the experiment composed, and
Hemonstrated a decomposition and recomposition of silex ; a
but before’such a conclusion could be made, many points
were to be determined.

It was possible, that the acid might be nitric acid, produced
as in other electrical experiments of a similar nature, and that
' this acid might have dissolved silex, which was precipitated by

the alkaline matter at the other pole, which might be either
potash used for disselving the silex, which had adhered to it,
netwithstanding the processes of lixiviation in acids, or am-
monia produced in consequence ef the presence of the at-
mosphere; or if potash was present; it was likewise possi-
ble, that the silex might have been carried over in solution,
with this alkali, from the positive to the negative surface.

. Minute experiments were instituted and completed in the but this not
same manner as those detailed in the Philosophical Transac- ‘8° "+
tions for 1807, p.7 *, which soon proved, that there was no

‘yeason to suppose, that the sitex had been changed in these
experiments,
~The aeid proved to he nitric acid, which under the elec- The acid was
trical action seemed to have dissolved the silex; the alkali ™™'*
turned out to be principally fixed alkali; and that it was Alkali not from
merely an accidental ingredient, and not a constituent of ‘R¢ S#ex-
the silex, appeared from this circumstance, that when the
same portion of silex was long electrified, by degrees it lost
its power of affording the substance in question +.

This
© *® Journal, vol, xvili, p. 325.
. + If silex, that has been carefully washed, after precipitation Common che-
dy muriatic acid from liquor silicum, be moistened, and acted on of coca
by mercury negatively electrified, the mercury soon cantains a no- bodies imper-
table quantity of potassium. Well washed alumine, that has been fect.
‘precipitated from alum by carbynate of soda, affords by the same
treatment sodium and potassium, so that the powers of electroche-
mical analysis are continually demonstrating the imperfection of the
-common chemical’methods of separating bodies from each other.
The purest boracic acid, which can be obtained from borax by
chemical decomposition, by electrical analysis is shown to contain
eth soda, and the decomposing acid empjoyed in the process; and

hence

$80

Treatett as ine
fiammables sa-
turated with
oxigen.

Silex 1 p. pot-.
ash6 p. kept in
fusion in a pla-
tina crucibie
and electrified.

ON THE DECOMPOSITION OF THE EARTHS.

This result having taken place, the same plan of operation
was not pursued with respect to alumime, which resembles @
saline compound less than silex; and the method which I now
adopted of acting upon these bodies was on the supposition
of their being inflammable substances so highly saturated
with oxigen as to possess little or no positive electricity.

_Alumine and silex have both a strong affinity for potash
and soda; now supposing them to be oxides, it was reason:
able to conclude, that the oxigen, both in the alkalis and
the earths, must be passive as to this power, which must
consequently be referred to their bases, and on this notion
it was possible, that it might be made to assist their decom.
position by electricity. }

After this reasoning, I fused a mixture of one part of si-
lex, and six of potash ina platina crucible, and preserved
the mixture fluid, and in ignition, over a fire of charcoal;
the crucible was rendered positive from the battery of five
hundred, and a rod of platina, rendered negative, was
brought into contact with the alkaline menstruum. At the
moment of contact there was a-most intense light; wher
the rod was plunged into the liquid an effervescence took
place, and globules, which burnt with a brilliant flame,
rose to the surface, and swam upon it in a state of com-

-bustion. In a few minutes, when the mixture was cool,

the platina bar was'removed: after as muchas possible of
the alkali and silcx had been detached from.it by a knife,
there remained brilliant metallic scales round it, which in=
stantly became coyered with a white crust in the air; and
some of whichinflamed spontaneausly. The platina appeared
much corroded, and of adarker tint than belongs to the pure
metal. When it was plunged:into water it strongly effer-
vesced: the fluid that came from it was alkaline; when 2
few. drops of muriatic acid were added to the solution, a
white cloudiness occurred, which various trials et DOE
to depend upon the presence of silex.

“eng the experiment on the action of the boracic acid and po~
tassium, page 375,. may. sei nie bes sagen rnin ~iempatass
its decomposition.

A similar

ON THE DECOMPOSITION OF THE EARTHS. 381

A-similar mixture of potash and alumine was experimented Alumine and —
g ' potash treated
upon in the same manner, and the results were perfectly ana- j,, the same
‘legous; there adhered to the rod of platina a film of a me. manner.
tallic substance, which rapidly decomposed water, and uf-
forded:a solution which deposited alumine by the action of
an acid. . .

tried several forms of this experiment, with the hopes The metal
of being able to obtain a sufficient quantity of the metaHic lar sat aes
matter from the platina, ‘so as to examine it in a separate rate.
state; but I was not successful.) It was always in superfi-
cial scales, which oxidated, becoming white and alkaline,
before it could be detached in the air; it instantly burnt
when heated, and could not be fused ‘under naphtha or oil.

I tried similar experiments with mixtures of soda and Experiments

alumine, and soda and zircone, and- used iron as the nega- ase
tively electrified metal. In all these cases, during the whole zircone and
process of electrization, abundance of globules, which swam some.
in a state of. inflammation on the fused mass, were produced,
And in themixture, when cooled, small laminz of metal were
found of the colour of lead, and less fusible than sodium,
which adhered to the iron; they acted violently upon water,
and produced soda and a white powder, but in quantities
teo small to be minutely examined.

I endeavoured to procure an alloy of potassium, and the Trials to obtain
bases of the earths, from mixtures of potash, silex, and alu- poor od pote
mine, fused by electricity, and acted on by the positive and ash unsuccess-
negative surfaces in the same manner as pure potash, in ex- -
periments for the decomposition of that substance; but I
obtained no good results. When the earths were in qnantities
equal to one fourth or one fifth of the alkali, they rendered it
so highly nonconducting, that it was not easy to affect it by
electricity, and when they were in very minute portions,
the substance produced had the characters of pure potas-
sium.

I heated small globules of potassium, in contact with si- Potassium heat-
lex and alumine, in tubes of plste glass filled with the vapour iat penises
of naphtha: the potassium seemed to act at the same time vapour of
upon the glass and the earths, anda grayish opaque mass, i
not possessed of metallic splendour, was obtained, which .
effervesced in water, depositing white clouds. Here it was

2 possible

3882 ON THE DECOMPOSITION OF THE EARTHS.

possible that the potash had been converted wholly or partly
Inconclusive, into protoxide, by its action upon the: earths; but as no
globule was obtained, and as the plate glass alone might
have produced the effect, no decided inference of the de«
composition of the earths can be.drawn from the»process.
I shall now mention the tase trials that I thade ha Tea
spect to this object.
Amalgam of Potassium, amalgamated with pe one ws thinds of i Re
Lo ae was clectrified negatively under naphtha, in contact with si«
lex, lex very slightly moistened, by the power of five hundred ;
after an hour the result was examined. The potassium was
made to decompose water, and the alkali formed neutral.
ized by acctous acid; a white matter, having all the ap-
pearance of silex precipitated, but.in quantity too small for |
accurate examination. ted i
xlumime, glu- ‘I tried the same method of action upon alumine and glu-
cine, cine, and obtained a cloudiness, more distinct than in the
case of silex, by the action of an acid upon the solution
obtained from the amalgam.
and Ziccone. Zircone exposed in the same manner to the action of elec-
‘tricity, and the attraction of potassium, furnished still more
satisfactory results, for a white and fine powder, soluble ia
sulphuric acid, and which was precipitated from sulphuric
acid by ammonia, separated from the amalgam that had been
ebtained by the action of water.
‘They allappeat From the general tenor of these results, and the compa.
ee bay metallic rison between the different series of experiments, there seems
very great reason to conclude that alumine, zircone, glucine,
and silex are, like the alkaline earths, metallic oxides, for on
no other supposition is it easy to Se the pivabatctia,
that have been detailed.
but the evi- Theevidences of decomposition and composition are not
dence not so however of the same strict nature as those that belong to the
ee fixed alkalis and alkaline earths; for it is possible, that in
the experiments in which the sifee alumine, and zircone
appeared to separate during the oxidation of potassium and.
sodium, their bases might not actually have been in combi-
nation with them, but the earths themselves im union with
the metals ‘of the alkalis, or in mere. mechanical mixture.
And out of an immense number of. experiments, ¥ which I
_ made

SCIENTIFIC NEWS. 383

tmade of the kiud lastdetailed, avery few only gave distinct
indications of the production of any earthy matter; and in
cases when earthy matter did appear, the quantity was such,,
as rendered it:impossible to decide an the species.

Had I been so fortunate as to have obtained more certain
evidences on this subjece, and to have procured the metallic
substances I was in search of, I should have proposed -for
them the names of silicium, alumium, zirconium, and glu-
cium,

- (To beconcludedin our next.)

SCIENTIFIC NEWS.
Wernerian Natural History Society.

Ar the meeting of the Wernerian Natural History Society Wemerian
‘on the 12th of November, the Rev. Andrew Jameson, mi- Society.
nister of St. Mungo, Dumfriesshire, read a paper entitled
Observations on Meteorological Tables, with a description

of a new Anemometer. After some general observations Meteorologica!
on the importance of meteorological observations, and on °Psrvations.
the merits and defects of registers of the weather, &c., he

pointed out what he considered to be the best form of a me-

teorological journal, and then described the external form

and internal structure of an extensive and complete meteor.

ological observatory, and enumerated about twenty differ-

ent. instruments, which ought to find a place in every esta-

blishment of that kind. He remarked, that a daily exami-

nation of the changes which take place in those instruments,

joined with a careful record of the external appearances in

_ the atmosphere, will afford a constant and fascinating em-

ployment to the most zealous observer, and will in time en- Their use.

> able us to form a just theory of meteors; to prognosticate

with considerable accuracy the nature of the coming wea.

ther; and, lastly, enable us to ascertain the climate of dif-

ferent countries, with the view of determining the influence

it exerts on organic bodies. He next described an Anemo-

meter, which, by a very simple and ingenious arrangement

of parts, will enadle the most common observer to ascere

tain the velocity of the wind with perfect accuracy.

) At. the same meeting, the Rev. John Fleming, F.A.S, Mineralogy of
minister of Bressay in Shetland, who has been for some; .. BER

time

384

Mineralogy of time past employed in examining the mineralogy of those .

the Shetland
isles.

SCIENTIFIC NEWS.

remote islands, communicated to the Society an interesting
account of the geognostic relations of the rocks in the

islands of Unst and Papa Stour; in the course of which he

gave answers to the queries formerly published regarding
the serpentine and sandstone of Shetland. After a general
account of the position, extent and external appearance of
the island of Unst, he next described the different rocks of
which it is composed, in the order of their relative antiqui-
ty, and remarked, that their general direction is from S. W.
to N.E. The rocks are gneiss, mica-slate, clay-slate,
limestone, hornblende-rock, potstone, and serpentine.—
The gneiss in some places appeared to alternate with the
oldest mica-slate, and in others to contain beds of horn-
blende-rock. The mica-slate, which is the most abundant
rock inthe island, is traversed by numerous contempora-
neous veins of quartz, and also of feldspar, and passes dis.
tinctly into clay-slate. It contains beds of hornblende-rock
and of limestone. The clay-slate occurs but sparingly in
this island. The potstone usually accompanies the serpen-
tine. The serpentine occurs in great abundance, in beds,
in the oldest clay-slate and newest mica-slate, and hence

must be referred to the oldest or first serpentine formation —

of Werner. Mr. Fleming is also inclined to believe, that
the serpentine of the neighbouring island of Fetlar belongs
to the same formation. The island of Papa Stour, situate
on the west coast of the Mainland, (as the largest of the
islands is called), contains ne primitive rocks; on the con-

trary, it appears to be entirely composed of floetz rocks.
These are, conglomerate, greenstone, claystone, porphy-

ritic stone, hornstone, and sandstone. The sandstone, as
appears from observations made in this island and other
parts of Shetland, would seem to belong to the oldest coal-
formation. The claystone, conglomerate, porphyritic
stone, greenstone, and hornstone (probably clinkstone)
rest on the sandstoue. In some places Mr. Fleming ob.
served the greenstone alternating with the sandstone, hence
he properly concludes, that they belong to the same forma~-
tion. In no place, however, did he observe any of the
other rocks alternating with the sandstone; and therefore
the formation to which they belong remains still somewhat
problematical.

‘ I-N- DoE X,

A.

ACCUM, Mr. his lectures, 78

Achard’s manufacture of sugar from
beat, 311

Acid, oxalic, experiments on, 14, 86

Acton, Mr. J. his examination of a
stone of the calcareous species, called
*Thuncer Pick’, 300—His simple
improvement in the common still,
358

Adrianople red, 44

Air, nature, use, and properties of, 159

Air pumps, 65, 161

Air-tight hinge, 61

Albiness, early account of one, 203

Alburnum, see Bark.

Alcohol, composition of, 222——Analysis
sof, 225, 259, 321

Alkalies, discovery of metals in, 68,
231—Decomposition of, 6S—Com-
ponent parts of, 139

Ammonia, unexpected production of,
290

Analysis of iron ores in Burgundy and
Franche Comté, &c. 52—Of metallic

sulphurets, 142—Of a carbonate of |

lime from Pesey, 150—Of alcohol
and sulphuric ether, 222, 259, 321
—Of the thunder pick, 301—Of
grape sugar, 541

Arcs of vibration, modes of equalizing,
ol

Avogadro, A. on the state in which a

stratum of nonconducting matter
must be, when interposed between

two surfaces endued with opposite
electricities, 278

Auarie, M. his chemical examination °

of the stalk of Indian corn (Zea Mays
of Linnzus) to ascertain whether the
Vou, XXI.

saccharine matter it contains be eapa-
ble of crystallization, 153

Avbuisson, M. de, on some granatoid
Lavas, 299

B.

Bancks, Mr. his observations on the
exhausting machine of Dr, T. S.
Traill, 161

Banks, Sir J. letter to, on the incon-
trovertibility of bark into alburnum,
5—Communication from, on the ap-
plication of coal gas to economical
purposes, 94

Banks, Mr. account of his instruments
employed for the Mcteorological
Journal, 79

Bark not convertible into alburnum, 5

Barlow, P. Esq. on polygonal numbers,
118—Answeied, 241

Baron on aluinine, 2657

Barraud, Mr. 236

B. H. on the doctrines of chance, 121
—Answered, 210

Beccaria, 288

Beccher, on sugar, 343—On the rela-
tion between mietals and earths, 367

Beddoes, Dr. on vital air, 68-——-On cer-
tain points of history relative to the
component parts of the alkalies, with
observations relating to the composi-
tion of the bodies termed simple,
189—On alkalies, 252

Bergman’s experiments on oxalic acid,
14—On barytes, 567

Berthollet’s experiments on oxalic acid,
14—-His analysis of a carbonate of

, lime from Pesey, 150

Berzelius, M. 873

Boat, an improved secure one, for sail-
ing, 124

b Bodies

INDEX.

Bodies termed simple, 139

Born, Baron, 233

Bostock, Dr. on albinos, 203

Boswell, J. W. Esq. his description of
a capstan, that works without ree
quiring the messenger or cable coiled
round it to be ever surged, 153

Botany, important discovery in, relative -

to the generation of vegetables, 214
Botfield, Messrs. T. W. and B. 116
Boyle, 367
Braude, Mr. W. 104
Brodie, Mr, 104
Brown, Capt. W. extract of a letter

from, 53
Buchanan, Mr, R. on the warming of

* mills and other buildings by steam,
316

Cc.

C. on Mr. Furniss’s air-tight hinge, 62

—On Mr. Murdock’s account of the

application of coal gas to economical
purposes, 101—-On the doctrines of

chance, 121, 212—=On the fecula of ‘

potatoes, 187

Calcareous stone, called Thunder Pick,
examined, 300

Capstan, an improved, 133

Carbonate of lime, new variety of, 359

Carbonate, compound, of lime, analysed,
150

Carlisle, Mr. 6

Cattle, diseases of, and remedies, 157

Chance, doctrines of, 66, 121, 204, 210

Chemical muffles, 273

Chimneys, machines for cleaning, 170,
173

Chronometers, improvements in, 51,
53

Cigna, M. 280

Clare, Dr, 66

Clark, B. Esq. 161

Clift, Mr. 104

Glock-work injured by jewelling, 236

Coal gas applied to economical pur-
poses, 94

Cochrane, Major S. on the culture of
spring wheat, and the use of tincture
of opium in diseases of cattle, 156

Collier, Mr. J. his improved ship’s
stove, 337

Combes, Mr. A. on the new metals,
231, 363 5

Combustion, spontaneous, 46

Compensation pendulum, *53

Cooke, Mr. W. on the decomposition
of alkalies, 69—-Observations on his
paper, inserted in the last Vol. on the
new metals, 231

Cook, Col. Wm., 316

‘Cook, Mr. B. on the advantages of em-

ploying coal gas for lighting small
manufactories, and other purposes,
291

Cordier, M. on volcanic substances,
298 ‘

Corny. Indian, chemical examination
of, 153

Coulomb, 281

Curvature, observations on the radius
of, 256

D.

Dalton, Mr. his theory of chemicai
atoms, 87, 164

Darget’s experiments on the sugar-cane,
514

Davis, Mr. his description of a machine
for cleansing chimneys, without the
aid of climbing boys, 173—his in-
vention to secure the pannels of doors
and window shutters from being cut
out by housebreakers, 177

Davy, Mr. on alkalies, 68, 69—On
the decomposition of earths, 159,
866—On the new metals, 231, 365
— His electro-chemical researches om
‘the decomposition of the earths, with
observations on the metals obtained

from

T Nae Xx.

from the alkaline earths, and on the
amalgam procured from ammonia,
566

D’Ambuisson, see Ambuisson.

Decomposition of earths, 366

Delametherie, M. extract of a letter to,
on volcanic substances, 298, 299

De Luc, J. A. Esq. on ignition by com-
pressed air, 234

De Moivre, see Moivre.

Deyeux’ discovery of liquid sugar, 313
—On the fermentation of vegetable
juices, 352

Dilettante, A. on the discovery of me-
tals in alkalies, 68, 232

Diseases of cattle, 157

Drowning, contrivances to prevent,
338 ;

Duhamel’s experiment on the converti-
bility of bark into alburnum, defec-
tive, 7, 10

Duthrone on the several species of
Sugar, &c. £13, ef seq.

Dyeing cotton and linen thread with ”

fixed colours, 44

E,

Farths, decomposition of, and metals
obtained from, 159, S66

Edelcrantz, Sir A. N. 66

Edinburgh Review of Professor Vince's
Essay on Gravitation, remarks on,
305

Ehrhart, 14

Electrical charges and discharges, 278

Encaustic painting, 82

Ensenada, Marquis de, 311

Escapement for watches, 178

Ether, sulphuric, composition of, 222,
259, 322

Exhausting Machine, 63, 161

F.

Fabroni, 352
Fecula, of the potato, 71, 182—Of
wine, 350, &c.

Feldspar, on, 195

Fermat's proposition on polygonal num-
bers, 118

Fleming, Rev. J. 883

Floating light, calculated to save the
lives of persons falling overboard in
the night, 338

Fourcroy’s experiments on oxalic acid,
14—-On the composition of alkalies,
232—.On the new metals, 363

Furniss, M. account of his new air-
tight hinge for a folding skreen, or
fora door, 61 .

G.

Gertner, on the generation of vegeta-
bles, 214

Gas lights, 94, 291

Gay Lussac, his rate of expansion for
every degree of the thermometer, 303

Geoffroy on the structure and use of
the pfincipal parts of flowers, 221

Gilpin, Mr. G. his improved machine
for raising coals or other articles from
mines, 111

Glauber, on the robof grapes, 351

" Gleichen, on the structure of seeds,

214

Gough, J. Esq. a mathematical pro-
blem by, 1—On polygonal numbers,
118, 241 *

Gravitation, S05-

Grape sugar, 306, 316

Greenland, Miss, see Mrs. Hooker.

Grew, on the generation of plants, 215

Gueniveau, M. his analysis of some
metallic sulphurets, 142

H.

Harrington, Dr. on the new metals,
231
Hatchett, C. Esq. communication from,
on oxalic acid, 14, 56—On metallic
sulphurets, 142
b 2 Hardy

INDEX.

Hardy, Mr. his account of inventions
for equalising the long and short arcs
of vibration in time-keepers, 57—
Testimony in favour of the perform-
ance of his chronometer, 53

Hauy, M. on Meionite, 192—-On
feldspar, 195—-On a new variety of
carbonate of lime, 359

Taussmann, J. M. on the maddering of
Cotton and linen threads, and dyeing
them Adrianople red and other fixed
colours, and on spontaneous inflam-
mations, 44

Henry, Dr his electrical experiments
on muriatic acid gas, 376

Héricatt, Thury, M. 360°

Hermbstadt, 14

Herrara, on the manna of America,
Sil

Hinge, air-tight, for screens, &c. 61

Home, E. Esq. on the spleen, 103—
On digestion, 187

‘Hooker, Mrs. her method of makinga
composition for painting in imitation
of the ancient Grecian manner, 81

Housebreakers, security against, 177

I,

Ignition by compressed air, 254

Indian corn, saccharine matter of, 153

Inflammations, spontaneous, 46

Jron ores of Burgundy, &c. analysed,
and their products examined, 32

J.

Jameson, Professor, 239, 383
J.B. on a method of finding the quan-

tity of refraction from the distance -

and altitude of two known stars; and
of solying by construction a problem
in spherical trigonometry, 201

Jewelled clock work disadvantages of,
236

Kerr, Mr. R. his translation of Lavoi-
sier’s Chemistry, 288—His theory of
the new metals, erroneous, 364

Kirwan, Mr: 191 ;

Klaproth on the reduction of earths into
metals, 564, 367

' Knight, T. Esq. on the incontrovert-

ibility of bark into Alburnum, 5

a

Laizer, M. De, 360

Lavas of volcanoes, 298, 299

Lavoisier on metallic substances, 233,
867

Lectures at St. Thomas’s, Guy’s and the
London Hospitals, 78—-On chemis-
try, &c. 78

Lemeri’s opinion on manna, contro-
verted, 310

Life-boat, 124

Lime, carbonate of, new variety of,
359

Lime, compound carbonate of, ana-=
lysed, 150

Locker, Admiral, his contrivance for
assisting persons in danger of drown-
ing, 340

Log, sea, and sounding machine, 245

Lothian, East, mineralogy of, 237

M.

Mabru, M. Augustus, 360

Machine on the principle of the Torris
cellian vacuum, 63, 161_

Machine for raising coals or ore, 111

Macquer’s experiments on the sugar '
cane, 314

Malpighi on the conversion of bark into
alburnum, 10

' Manna, examination of, 310

Margraff's

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a

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ren amy — a 50} bie myn
oa ee Pe Na

INDEX.

Margraff’s discovery of sugar in vege-
tables, 311

Maskelyne, Dr. on log-lines, 249

Massey, Mr. E. his description and use
of asea log and sounding machine,
245

Mathematical problem, 1

Meionite, remarks on, 191, 199

Mendham, Mr. his description of a new
watch escapement, 176

Metallic sulphurets, analysis of, 142

Metals, new, 68, 159, 231, 363

Mcteorological Journal, for August, 79
—For September, 160—For Octo-
ber, 240—-For November, 318

Meteorological observations, 383

Mineralogy of East Lothian, 287—Of
the Shetland Isles, 383

Mirbel, on the structure of seeds, 214

Mirhel’s theory of the convertibility of
bark into alburnum, examined, 9

Mohs, M. on meionite, 191—On feld-
spar, 196

Moivre, De, on the doctrines of chance,
673 see also 121, 204, 210

Moll, Baron, 192

Moore, W. Esq. on the problem re-
specting the radius of curvature, 256
udve, Mr. his escapement for watches,
ih)

Muffies for chemical purposes, im-
proved, 273

Murdoch, Mr. W. on the application
of the gas from coal to economical
purposes, 94

N.

Neve, Capt. R. J. his testimony of the
performance of Mr. Massey’s patent
sounding machine, 255

Neuman’s experiments to obtain a me-
tal from quick-lime, unsuccessful,
367

Nichols, Mr. J. 53

Numbers, polygonal, 118, 241

oO.
Ogilby, Dr. James, on the mineralogy
of East Lothian, 237

Opium, tincture of, reeommended for
diseases of cattle, 157

Opsimath, letter frem, expressive of
doubt as to the validity of De Moi-
vre’s doctrines of chance, 66—An-

swered, 121, 205—Second letter from,
210

Oxalic acid, 14, 86

P;

Painting after the ancient Grecian man
ner, 81 '
Parsons, A. his account of a pheno-
menon that occurred at Bussora, 77
Pearson, Dr. his experiments on pota-
toes, 72

Pendulum, improved, 53

Phenomenon at Bussora, 77

Playfair, Professor, 238

Polygonal numbers, 118, 241

Pontin, M. S/S 4

Poppies, cultivation of in England for
obtaining opium, 158 ‘

Potato, on the fecula in different yari-
eties of, 71, 182

Priestley’s history of electricity, 280

Problem in mathematics, 1

Proust, Professor, on grape sugar, 306,
316——On metallic sulphurets, 142

R.

Radius of curvature, observations on
the problem of, 256

Ramsay, Mr. on Mr. Mendham's new
watch escapement, 179

Red dye of Adrianople, 44

Refraction, method of discovering the
quantity of, 201 s

Ribblesdale, Lord, his account of a
mine of zinc ore, and its application
as a paint, 12 *

Ruprecht’s experiments on the metallic
nature of earths, 68, 234, 364, 367

Ss.

Saccharine matter of Jndian corn, che-
mical examination of, 153
Sailing

INDEX.

Sailing boat, a secure one, 124

Saint, W. Esq. on the doctrines of
chance, 204

Salts, superacid and subacid, 164

Savaresi, on metals obtained from earthy
substances, 367

Saussure, Theodore De, on the com-
position of alcohol and sulphuric
ether, 222, 259, 321

Scheele’s discovery of oxalic acid, 14

Scientific news, 78, 159, 227, 316, 383

Sea log, anew one, described, 245

Seeds, newly discovered organ in, for
conveying the fertilizing fluid into the

_ ovula of vegetables, 214

“Sewell, Mr. 104

Shipley, Mr. W. his floating light, cal-
culated to save the lives of persons
who have the misfortune to fall over-
board in the night from any ship, 338

Simple bodies, 139

Singer, Mr. G. his lectures on the na-
ture, use, and properties of air, 159

‘Bkrimshire, Mr. W. jun. on the quan-
tity of fecula in different varieties of
the potato, 71, 182

Smart, Mr. G. his account of some ex-
periments on sweeping chimneys,
170

Smeaton’s experiments on Saumarez’s
lop, 247, 249

Snodgrass, Mr. his application of the
use of steam to warm his cotton
works, 316

Sounding machine, a new one described,
245

Spherical trigonometry, see Trigonome-
try

Spleen, experiments on (continued
from a former volume), 103

Spring wheat, culture of, 156

Stahl, on the relation of metals to
earthy substances, 567

Steam used for warming buildings, 316

Stills, improvement in, 558

Stone called “ Vhuuder Pick”, ex-
amined, 300

Stove for ships, improved, 337

Sugar, different species of, particularly
that obtained from grapes, 306, 316

Sulphurets, metallic, 142

Sulphuric ether, see Ether —

Symmer, Mr. 280

7

Tar, recommended for cattle swelled by
eating clover, 157 ;

Thenard, M. 352, 365

Thomson, Dr. T. on oxalic acid, 14
86 ’

“¢ Thunder Pick,” the, examined, 800

Timekeepers, 51, 53

Tondi’s experinfents on the metallic na-
ture of earths, 68, 233, 364, 367

Tonnelier, M. on meionite, with some
observations on a papcr, by M. Fre-
derick Mohs, in which this substance
is considered as a variety of feldspar,
191

Torricellian vacuum, see Vacuum

Trigonometry, spherical, method of
solving a problem in, 201

Traill, Dr. T. description of his ex-
hausting machine on the principlag
of the Torricellian vacuum, 63, 161

Turpin, P. on the organ by which the
fertilizing fluid is capable of being in-
troduced into the ovula of vegeta-
bles, 214

Turrell, Mr. his improved mode of con-
structing muffls for chemical pur-
poses, 273

Vv.

Vauquelin’s experiments on oxalic acid,
14——His analysis of some iron ores in
Burgundy and Franche Comté, with
an examination of the pig iron, bar

iron, and scoriz produced from them,

32

Vacuum, Torricellian, an exhausting
machine on the principle of, 65, 161

Vegetables,

Hy t

Ts DE

Vegetables, fecula of, 81, 182

Vegetables, generative organs of, 214

Vibration, modes of equalizing the arcs
of, 31 bf

Vince, Professor, remarks on the re-
view of his essay on gravitation, 305

Volcanic substances, 298, 299

Volta, 279, et seq.

Von Ruprecht, Von, see Ruprecht

Ww.

Walker, Mr. W. on the disadvantage
of jewelled holes in cloek-work, 236

Ward, Mr. H. his description of a com-
pensation pendulum, for a clock or
time-piece, with experiments, 53

Watch cscapement, anew, 178

Wermer, M. 191

Wernerian Scientific Society, 237, 383

Westrumb, 14

Wheat, spring, 156
Whittle, Capt. 249
Wilson, Mr, C. his description of a se-
cure sailing or life boat, 124
Windlass, -an improved,. 133
W.N. in answer to Dr. Traill’s letter
on the use of mercury in air pumps
for exhaustion, 66—Cn the existence
of metals in alkalies, 68, 231, 365——
In reply to Mr. Cook, 297
Wollaston, Dr. on super acid and sub-
acid salts, 164
Woodhouse, James, Esq. his account
of an experiment, in which potash
calcined with charcoal, took fire on
the addition of water, and ammoni-
acal gas was produced, 290

Z.

Zinc ore, its uses as a paint, 12

END OF THE TWENTY-FIRST YOLUME..

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