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A 588429 



► 



RETROSPECT 

PHILOSOPHICAL, MECHANICAL, 
CHEMICAL, AND AGRICULTURE 

DISCOVERIES ; 

BEIVO AV 

I 

PERIODICAL AND OTHER PUBLICATIONS, 

£NGLISH AND FOREIQNi 



« • . 



XELATXVB TO 



Arts, Chemistry y Manufactures^ Agriculture, and 

Natural Philosophy ; 

ACCOMPANIED, OCCASIONALLY, WITH 

SlEJif ARXS ON THE MERITS OR DEFECTS OF THE RESPECTIVf 

PAPERS; 



?*v 



AKDy IN SOME CASES, SHEWING TO WHAT OTHER lieEJfUif 

TUKPOSES INTENTIONS MAT BE DIRECTED, J^» 

DISCOVERIES EXTENDED, BEYOND THE 

ORIGINAL VIEWS OF THEIR 

AUTHORS. 



^ 



VOL. VL 

■'I I U LX 



LONDON: 
PRINTED FOR THE PROPRIETORS, 

AH© «OLD BY W. H. WYATT, AT THE REPERTORY Of ARTS AK^I 
PATENT-OFFICE, NO. 9, PICKETT-STREKT, T*MPiB-BA», 



ST- 






I 11 H| <i 



0mm 



PoplcMMlMUler* Prin^rp, Qld Bonr«U-Court, handtm. 



T ' ^ 



' i 



COM-ENTS 



01 TBm 



SIX.TH VOtUMB. 



KATURAL PHILOSOPHY, ARTS, and MANUFACTURES. 

Pagf 
Iftethod of dWiding astronomica! and other inftrutnents, by ociilac i»> 

apectioU) in which the usual toob for graduating are not employed ; 

the whole operation being ^ so contrived, that no error can occur 

bat what is chargeable toviuon, when assisted by tiie best optica) 

means of viewing and measuring minute quantities. By l^lr. Edward 

Troughtoa ------ f 

On an improvement in the maimer of dividing astronomical instr^- 

,ment& By Henry Cavendish, Esq. F. R. S. - - H 

0n a metliod of examining the divisions of astronomical instruments. 

By the Rev. William Lax, A. M. F. R. S. - • IS 

Description of a new cupping instrument. By Robert Healy, 

MB. '• - - - - -Id 

On the parabolic lens of Eospim. By Mr. CoutcB. - - ir 

Beport of anew nangable canal, proposed to be cut from Okeham to 

Stamford, and from thence to the town of Boston. By Thomas 

Telford, esq. -*---!& 

On aerial ua^0ition. By ^CreorgeCavley, bart - - J|t 

Bf aching for b^ing roota for cattle, ardcles for dyei's use, or for culi? 

nar^ purposes. - By Mr. Thomas Newton. - - 2f 

Machine for making slate pencils. By Mr. J« llrockbank. ' - fff 

Sfacliine forq^anufocturing sUk covered wire, and thread covered with 

silk^ By Mr. lliomas Saddingtbn. . . . ||f 

Biethods of nusing the bodies of persons who have sunk under water, 

or of assisting persons in danger in vrater. By John Miller, 

esq. ...... iljlL 

Method of securing the beams of shi^, without wooden Knees mad« 
' of one piece. By Mr.' George Williams. - -5% 

Vaval improvement. By €aptain William Bolt^. * - 3S 

Method of constructing commodious houses with earthen walls. By 

Mr. Robert Salmon. - . . . - d^ 

On Iris seen in the dew, and a lunar Iris, with an annotation. By 

A-M. - - - - - . 4a 

^On the propagation of sound through unelastic iluidsb By Francis 

Ellis, esq. with an observation by Mr. Nicholson. - • 41 

Anthropo telegraph, or oiode of communication in tlie day or night 

by disks. ' By Mr. Knight Spencer. - . -4$ 

Ifomqgraph, or method of cofluattoication by ugnals^ vn sea or land. 

By MnJamesSpratt. •>.-•- Ibid, 



386938 



!▼ CONTENTS. 

ImproYed file for receipts and letters. By Richard White, esq. - 44 

Demonstratiou of the Cotesian Theorem. By Mr. P, Barlow. - 45 

Proposal for an mstitution for obtaining an eqaal temperature in hou?ci. 

By Dr. Pearson. - - _ _ - 4f 

On Dr. Pearson's proposal for obtaining an equal temperature in 

houses. By Ceneps. - - - - _ ibid. 

On the means of counteracting the effects |)roduced by the Forma- 
tion of gasses found in coal mines. - - - 4S^ 
On the method of transforiBing a number from one scale of notation 

to another, and its application to the ride o( duodecimals. By Mr. 

Peter Barlow. - - - - ' - _ 51 

Inqiuries concerning the influence of light on the propagation of sound. 

By Modeste Parolette. - - - - 57 

On th« camera lucida. By Mr. f. Sheldrake. With a remark by 

W.N. ... . . . -. 6« 

Qn the camera Incida. By Mr. B. Bate. ... ibid. 

Ob the use of the camera luada as a substitute for the camera obscura. 

By Mr.T.Sheldrakf. - • . - - - ibid, 

Observations on loaded and unloaded barges, boats, beams, or floating 

bodies descending with streams or currents, and why the heavier 

end will go foremost. By George Orr, esq. • - . - 6t 

On the Volcanoes of JoruUo. By Alexander Humboldt. - - 117 

Report made to the French Institute, on a Memoir of M. Delaroche 

f>n the Air-bladder of Fishes. By ]\|[essrs. Lapecede, Yauquelin, 

andCuvier. - - - - * . IJq 

Ta^le of Kain, that fell at Various places in the year 1809, by the 

"Rtr. J. Blanchard, of Nottingham : with a Meteorological Table 

for the same Year. By Dr. Clarka ofthat Town. - - %f5 

IJn Azimuthal Refraction. By Mr. Charlas William*. -. ' - ttj 

Kcmarks upon Meteorology : with a Specimen of a New Meteoro- 
logical Table. By J. Bostock, M. D. Remarks on Meteorology. 
. By Thomas Foster, Esq. - - - . - iSi 

Qn the Art of Printiiig with Stone, and especially on the Progress 

which this Art has 'made in Germany. By M. Marcel de Scrres. 1381 

On. the power of the Eye, by which it is adjusted to ttie Objects 

distinctly, at diflierent Distances. By Ez. Walker, Esq. . 140 

jKote of a Discorery of Mr. Varca in Magnetism. - - 14!^ 

Sxtract from a Memoir of Messrs. Mouchci, of I'Aigle, in the De- 
' partment de TOrne, on the manufacturfc of Iron and Steel Wire. ibid. 

On the construction of Theatres, so as to render them se-cure against 
,Fire. By Mr. B.Cook. - - - - 145 

Tools to answer the purpose of Files and otlicr Instruments, for 

rarious uses of Stone-ware. By G. Culiiberland, Esq. - - j4f 

An Inquiry, Geometrical and. Asfthmetic^d, into certain Properties 

of Solids in general, and of the five regular Bodies in particular. 

By John Gough, Esq. - - - - 1.^0 

Description of a Clock Escapement, invented by Mr. George Prior, 

Jun, ' ' - - - J 131 

Jpescription of the Frepch Telegraphs used ort the Coast of Flanders, &c. 

with . Observations on tiie sanrp, and a plan of a Poly'.raniuiatic 

Telegraph on a new construction. By Cap. C. W. PdVlcv. - 152 

Account of a Method of dViving or forcing forward Si«ips'"or other 

Vessels by tlie power of Steam Engines. By Mr. Jaraes Linaker. l.'iX 

Op the Composition and Decomposition •( Forces By ]\lr. W. 

If arrat. ' - - - - r 155^ 






COKTBNTS. 



Dtscription of an !Eye Bath, to clear the Eye from extraneous matteri» 
and to assist the Siglit. By Mr. John JJuckelt Ross, 

Kew Theory of the Diurnal Motion of the Earth round its Axis, By 
Professor Wood, Richmond Academy, State of Virginia. ^ 

^n Telegraphic Communications. ' By Richard Loveli Edgeworth, 
• Eaq. . - - - - - - 

Obserrations -on Dr. Bostock's Remarks upon Meteorology. By Luke 
Howard, Esq. - - - • - .. 

On Meteorological Nomenclature, in answer to Luke Hovrard, Esq. 
By J. Bostock, M. D. - - 

Remarks on Mr. Richard Walker's proposed Alteration in the Scales 
of Thermometers. By Londinensis. - - - , 

ll^ote, relative to a Method of constructing wooden Bridges. By M, 
Wiebekrng. - - - - . • 

On Pendulums. By Ez. Walker, Esq. - - - 

^experiments on the comparatiye Powers of the Cylinder and Plate 
Electrical Machines, and on a means of doublings trebling, quadru- 
pling their charging power. By Mr. John Cuthbertson, and Mr, 
C. J. Singer. -----», 

On the Discoveries which Daerfel and Hevelius made in the Theory of 
Comets. By J. C. Buckhardt. - ' - 

On the Action of the Electric Fluid, by which an Iron Cylinder an ^ 
inch and a half tliick was torn asunder -, in a Letter from Mr.**** to 
J. C. Delametherie. - - . 

Kemarks on the preceding Experiment. By J. C. Delanetherie. 

On the Ring of Saturn. By M. Laplace. ... 

Memoir of the Determinatibn of the Obliqalty of the Ecliptic, which 
results from ancient observations. By M. Laplace. 

Proposal tor constructing and putting in its place, an Iron Tunnel un- 
cter the River Thames. By Colonel Lemion. - * - 

pescription of a Metallic Thermometer for indicating the higher De- 
grees of Temperature. By Richard Walker. 

On the Influence of So)ar and Lunar Attraction oa Clouds and Ta* 
pours. By Salem Harris, Esq. - . - 

On prime and ultimate Ratios, with their application to the first Prin- 
ciples oft he fluxionary Calculus. By Mr. W. Marrat. 

On the land winds of Coromandel, and their causes. By W.Roxburgh, 
M. D. - - - . - - 

I^marks on a new principle introduced by Legendre in his elements of 
geometry, by Mr.T. Knight. •- - - - 

iVccount of a new method of increasing the charging capacity of elec- 
trical jars, discovered by J. Wingfield, esq. By J. Cuthbertson. 

Pemonstration ot acurious numerical proposition. By Mr. P. Barlow. 

S^ond vindication of Br. Herschel's theory of coloured rings, in an- 
swer to an anonymous reviewer. - - - - 

J^ physical view of the equatorial regions, from the tenth degree of 
north to the tenth degree of south latitude, drawn up from measures 
and observations made on the spot, between the years 1798 and 
1804. By Mr. Von Humboldt. - - - - 

Historical note on the means employed by astronomers for observing 
the sun. By J. C. Burckhardt. - - - - 

Table of the tides for the year 1811. By Mr, Bouvard. - 

.On ttie application of the barometer for indicating the weather, and for 
measuring of heights in the atmosphere. 

On the barometer. By Richard Walker, esq. - 

^n the baroiaeter. By R. Walker, esq. t ^ ? 



Page 

159 
509 
314 
SIS 

ibid« 
SU 

ibid. 

Sir 

SfS 

ibid. 

srr 

SSt 

sss 

541 

37S 

576 

37« 
ibid. 

580 

Stl 

387 

589 

390 

594 

iUil. 



in CONTBNT». 



P«g« 



ObseiTHtions on tvhdel carmges, roads» and draught of lun-ses, inTesti- 
gstions of' the mechanical mode% of action of , the horse, and of the 
size and breadth of wheels, and descriptions of three new species of 
wheels, contrived to facilitate draught, and to preserve the roads; 
with some remarles on asUes and boxes, and an account of a proposed 
improvement in harness. Bj J. W. Boswell. - - S9H 

Description of a camp telegraph, invented by K. Spencer, esq. - 405 

l|ec(nt state of the iron manufactory in Great Britain. - - 405 

Engraved slates for teaching writing and arithmetic, by Mr. T. Wairen. . 40^ 
Scheme for preserving the lives of persons shipwrecked. - - 409 

Supplement to the first and second part of the paper of experiments^ 
ier iirvestigating the cause of coloured concentric rings between ob> 
ject glasses, and other appearances of a amilar nature. By William 
Herschell, LL.D. F.R.S^ - - - - 468 

tAiocrvatioQs on atmospherical refractioi) as it affects astronomical ob- 
servations; in a Lettet from S. Groombridge, esq. to tlie Rev. Nevii 
Maskelyne» P.D, F. R.S. Astronomer Royal. (^ • 47'tf 

ISstract of a letter from the Rcr. John Brinkiey, B. D. F. R. & An? 
drews professor of astronomy in the University of Dublin, to the 
Bev. NeviJ Maskdyne, D. D, F. R. Si Astronomer Royal, on the 
aanual paraHax of a lynoe. - , - - - ilMd, 

A short account of the improvements gfadually made in determiniag 

theastronoNuealiefracI^. - - - - it»id, 

Bpme particulars respecting the thunder storm at l^ndon, and in its 
Ti<inity, on the SUst o£ August, 1810. By Sir H, C. Eoglefidd, 
hart. F. R.S. and F. S. A. - • - - - . 483 

i>n the mountain barometer. . By Sir H. C, J^glefield, hart - 486 

y^sAs respecting a new theory on orbits of comets. By Mr. W. Crane. 486 

i>n the penetradoa ofbaUs vf^to uniformly resisting substaaccs. Bj 
W*Mpo{«, esq^ - ' ^ • - 487 

REVIEW or SPJICTFICATIONS op PATENTS, 

JUTr. John Leigh Bradbury's for a method of spinning cotton, flax and 

wool. - - • - ' - €6 

|ffr. Fredenc Bartholottiew Folsch*s for several improvaments on cer- 
tain machines, instrumepts, and pens, calculated to promote faci- 
Efy in writing. - - * • - -67 

If r. Edward Manfey^s for a plough. - , - - * 68 

Mr. William Hutton's for a method for making tickles and reaping 

hooks. * - - - . - - -69 

Mr. John Bartoo*^ for a lamp of a new construction. « . / - 70 

Xfr. John t)\xS*a fot snu^rs of a new and improved construe* 

tion, - r - - - - 71 

JfiTr. James Rarron^s for improvements in the apparatus used for rollers 

for window blinds, maps, and other similar objects. * - 7t 

Mr. George Pocock's for his inveni ion of geographical slates for the con- 
struction of maps. - - f. ** - 

Jlllr. John Jones's fpir in^provementsin manufacturing ofskelps for fire 

arms. . - . . . . ibij^ 

Mr. David Meade Randolph's for certain improvements in the con- 
struction of wheel carriages of every description. - - 7^ 

Iff. John Dymbcirs for a method or methods of flax spinning, and of 
preparing or making a species of twist, thread, furniture, cloth, trills, 
or attire, wliich he calls Teiary Tegument^ from si|k, wool, cotton. 



P^ 

flm, Ken)p» or tow, ts well is from a yery gr«at vtn^ety of otlier nrw 

tides, in a combined or uncombined state ; and for a method or me- 
thods^of refabricating or renovating the same, and of produdng or 
reproducing, from tatters in general, anew body. * • 79 

;^Ir. John Manton's for an improved lock for guns and pistols. « QO 

idi. John Wliite's patent for the dbcovery of a s«tbstance> capable 

of being converted into statues, artificial stone, &c. - - '1^ 

Mr. Mare Isambard Brund's patent for cutting veneers or thin boards 
by machinery. ..... IIh4« 

Mr. Augustus Frederick de Heine's patent for improvements on print- 
ing and stamping presses. .... -j^i^ 

Mr. John Manton*s patent fon improving timekeepers - • lOt 

Mr, Phiilis Brown Thompson's patent for umbrellas and parasols. - '163 

ISdr. John Schmidt's patant for a phantasmagoric chronometer, or 

nocturnal dial. .... . . ^9^ 

3^. Charles Le Caan's patent for an apparatus to «heck the action 
, ofcfu'riages. . - - . . xfl$ 

Itf r. Randijph Tsehi^Q^ 6m Boehe's patent for improvements in the 

process of brewing. - . . . . tOS 

Mr. John Frederick Archbold's patent for a method of converting 

salt or sea water into fresh water. ... . ^ff 

Sir. Charles Valentine's patent for a new mode of ornamenting and 

- paii^dng all kinds of japanned and vamuhed wares. - • fUd. 

JlCr. Peter Warbnrtbn's patent for deooratmg ohina, proceluo, earth- 
enware, «nd gloss, with gold, silver, platina, and other metals 109 

Bf essrs. John Marshall, and John Kaylof s patent for manufacturing 

.and making salt. . .' . . . • ifo 

'Vt, John Penwama's patent for a process Ibr giving to statues or other 
omamtntai works in plaster, an appearance nearly resembling the 
finest statuary marble. ... . . 34$' 

Mr. John Thomas Srove's patent for an improved mode of construct- 
ing buildiiws, by which great expcnce, labour, and time aiesavedt 
and thebswlings secured iitom the dry rot, with other advaata^ - M4 

iMr. Jamas Goddard's patent for manniacturing a certain description of 

iroodenboxes,oalled chip or mil boxes. . - . ^45 

Mr. William Dockse^s patent for conMderable improvtments in the 
process of manufiirtming ivory black ; and for pulverising .all arti- - 
cides capable of a more easy separatioQ of their parts or coDstituient 
principles. -.---- S4f^ 

.Mr. John Cruge's pattnt for an improvedkitchen fire-place. • A^B 

Jttr. Richard Witty's patent for making, arran^ng, and comfainingoer- 
tain parts of rotative steam engines, by which means the most com- 
plex parts of the steam engines now in use are dispensed with. - M' 
.Mr. Jamas Hall's patent for making shivers and puUej whoeb of 

earths and minerals. ...... J51 

Mr. John WilUam^s paiOBt for a certain appnratus to be applied to 
And used with whtel carriages, in order to render the same more 
safe and -comouKlions. ... - . - ^jjg 

jMr. William Congreve's patent for a mode of constructioa or arran|(e- 
ment for any boiklnig so as to afford seouHty against fise, with 
other advantages. - ^ - - - — *> S5S 

^r. John Shtet's patent for an impsovement in hanging and -securing 
•grindstones frombreakinginthe middle or the centre. - - S5^ 

IjHr. Joseph Warrau Bavere^s patent for a new and improved.method 
of splitting hides, and-^bAving- leather, conununicated-to him by li 
foreigner* ... . - . 410 



Viii doKTENTS* 

Ifr. J. Vart^?8 patent for certain improvements in the axle-trees of car- 



nages. 



411 



If r. C. Williams's patent for a machine for grinding or cutting malt, 
splitting beans, or any other kind of grain, and various other arti'* 
cles. - . - - * - - 41« 

Mr. E. Shorter** patent for an improved apparatus for working of 

pumps. - - - - * 415 

Mr. J. A. Berolla«*« patemt fdr a warning Watch upon a new construe- 

tion. - - --. - . -^ . 4/4 

Mr. J. Maiben*s patent for an apparatus for making carbonated hydro- 
gen gas, and applying the same in lighting buildings, &c. - 415 

Messrs. Wm. Shakespear and Thomas Osier's patent for a new and ira- 
proTcd methoci or methods ot manufacturing glass or paste drops for 
chatidcliers, lamps, and lustres. - - - - 41T 

Mr. Stephen Hoopar's patent for a thermometer, or machine for ascer- 
taining the heat of bakars' ovens, and various other purposes. - 413 

Mr. John Onion's patdnt for a machine for thrashing corn and other 

grain, on a new construction. - ^ - - ^ - 41^ 

Mr. Frederick Albert Winsor's patent for improvements in his oven 
ateve, orapparatusforcarbonizingallsortsof raw fuel, &c. and for 
extracting the oil, tar, pjrolignous acid, and ammoniacal coal li- 
quids, -and for extracting and refining all the inflammable air or gas. ibid. 

Mr. Joseph Stevenson's patent ibr a machine for filtering and purify. 

ing water. - - - - - - 490 

Mr. Thomas Robinson's patent for a mashing machine. - - 494 

Mr. William Watts's patent for methods of combining and disposing 
. machinery, and applying the different powers of wind, water, and 

cattle thereto, so as to effect improvements on mills. - * 49* 

AGRICULTURE. 

On planting forest and other trees. By A. C. R. of Castle Combe. 81 

On the price of Anglo Merino wool. By Benj. Thompson, of Redbill 

Lodge, Notts. - - - ' - - * tit 

'On the Anglo Merino question. By Agricdla Northumbriensjs. •» ibid. 

Observations on the speculative opinions of Mr. Thompson ; and expe- 
rimental evidence of Mr. Wright and Mr. Hose. By John Hunt> 
of Loughborough • . - - - . ibid. 

On shoeing the ox and the horse. Br Clericus, of Buckinghamshire. 85 

On the drill culture of carrots. By R. S.D. ofWindsor Forest. - ibid. 

On the culture of carrots. By A.N. F. of Worksop. - - ibid. 

On coverings for hay and corn ricks. By Economicus, of Aylesbury. 64 

Hints relating to an improvement on the thrashing machine* By Alex- 
ander Scot^, of Ormiston. - - - . ibid. 

iOft the potatoe curl. By James Inglis, of Parkhoira, near Glasgow. - 85 

An useful premtratory step when thorn hedges are to be planted on 

clay soils. By John Reid, esq. of Castle Hill, near Kilbride. - ibid. 

^imate of the expence of inclosing by hedge and ditch. By R. G. 

of Perth, • - - - - -9^ 

On the expense of inclosing by hedges. By Calculator, of East Lo- 
thian. - - - - - - ' - ibid. 

On the inutility of plucking potatoe blossoms. By the Rev. Charles 

Findlater, of Newlands^ - - • . | ibid. 

Kew plan for coustiQcting roads. By Messrs. Winton and Nisbet, of 

Kdifljburgh. •-*--.-H' 



li)n th« compawtlve Profits of Wiltohire Merino-otosi Sheep. By 

Morrif Birln^ck, of Warborough, in Surrey - " . * *^ 

X}i tlie culture of parsneps io the Island of Jersey, and tlieir utility 

in feeding Cattle. By Charles Le Hardy, Esq. - - . JS4 

On the properties of furze and w^iins. By Major Spencer Cochrane, 

of Marsfieid Houses North Britain - - - - 9Sf 

Circumstances relative to Merino ah^p, chiefty collected from the 
Spanisli ihepherds, who attended flocks to tms country. By^r 
Joseph Banks, K. B. - - . * . .' " * ^^ 

On Sicilian wheat. Queries from Sir John Sinclair, with dnswers, by 

the Prince di Castelcicida. - - ^ ^ - - 285 

Hints regarding a Spanish grain, called Bscanda. ^ Sir John Sin- 
clair, baft. . - - - - - 2tPf 
On the use of barley for horses. I>ra,wn up by order of the Board. - 28S 
On naked barley. By Warren Hastings, esq* • - • 28^ 
On Grecian barley. By Coloiicl Mitfwd. - - %- t90*" 
On the use of soap<mak«iv wastfc ashe3, commonly called soapei^ 
waiste, as a manure. Drawn up by prder of the Board of Agri* 
cnltnre, and published by ifs direction^ • . «. f^x 
Queries regarding experiments with long diing, with answers. By 

T. W.Cokc,esq,M.P. * • - • f9a 

Ob irrigation. By G. R, Eyres, cso. of Lynford Hall, Norfolk. ' • . S9S 
On the mapfe tree. By James Hfallt esq. . - . . • llud. 

On the advantages tti^ bo deriyed from heath in feeding of stock. By 

James Hall, esq* - - - - . 29^ 

Horses and oxen compared. By the Rev. R. Kedington^ <^ Rougham^ 

nearBurV) Sutfoik. - - - • . ^95 

6n oxen. By David Barclay, esq. - ' « - 504 

On horses and oxen compared. By Mr. Whitworth. • • ibid. 

Memoir on seed grain. By Sir Joseph Banks, K. 6. • - ibid. 

Comparative experfments on the culture and application of kohl- 
rabi, drum-headed cabbage, and Swedish turnips. By Mr. John 
Saddingtou, of flnchley. -■ - - . f9^ 

Oa * preparation from bean-stalks, as a substitute for hemp. By tlie 

Ker. James Hall, of Walthamstow, Es&ex» -' - . 299 

.On planting oaks. By William Cougreve, esq. of Aldermarston 

House, inBerkshire. - - - > - . ^90 

Statementofdrilled and broad-cast husbandry. By Messrs. Betchelor, 

ofXidliiigton. - - - - • 301 

Account of land gained from the sea. By Mr. William Laurence. • ibid. 
On the management of cattle in the Highlduds of Scotland. . 30jt 

Oft the mode of preparing Frciiuh vinegar, and- the ditfcrent species of 

the article wliich are raanuiactiired in France. - - 303 

Description of a threslili'ijj milllutcly iuveniecL ByW. B. - 304 

Thought9«0!i the-perlods of so wing i;eeds of different kinds. By A. M. ibid. 
Cheap plan of a sheep-house^ B3' A. S. - - ■ - %q$ 

On the irapropnety of mixing the seeds of grasses, when Land is 

sown down for paKturage. By T.Ir. James Ileadrick. - - ibid. 

Odl the disease in cattle called the blark ^pald. ByW. F» • 30fi 

Ol[>scrvations on the u;se oi lime. ByO — a — s. - \ • 30^ 

Observations on the method of laying down pasture and meadow 

Land, with an account of some pas^ires made with the meadow 

Rescue grass and clovers. By Mr. W. Salisbury, of Brompton. - ihjid. 

An essay on the mathematical construction of a ploogli, wtiich slmlt 

»fier the leakt resistance, and which filial! turn a furrow ^ ] 



offer the leakt resistance, and which ;uiaU turn a furrow ^ the b^t 
manner. - • > - «. « 

b 



.5^ 



On comliiuing two» thrr^, and four of these ploughs t6getfaer» to ai to 

faveonc-tbiirth of the ordinary expence of ploughing. - - ibid., 

On the construction of a d^hanomcter for measuring the relative resis- 

tauces of ploughs. - - - - ibid.. 

'On tlfe construction of a new fashioned roller, and of a nev set of Iiar- 
rovfs foir harrowing aud rolling corn in the spqiig, and in moist laud ^ 
wifliout tlie horses treading it. - - - - ibid. 

On breaking young iiorses and oxen to all linds of work easily, safely, 
and ex|)editionsly. - - - * - - , ibid» 

On ^1ie construction of wheel carriages upon a new principle. By Mr. 

W* Amos. - - - - - - " ibid* 

A letter to Sir John Sinclair, bart. containing a statement of the sys- 
iei9 under which a considerable farm is profitably managed in Hert- 
fordshire. By T. Greg, esq. - - - - 361 

I^Lcmorandum as to spring crops without spring ploughing ; also as to 

arable land. By Mr. D. JVIaynard.of Wliittlestonl, near Cambridge. S69 

£x pe'rimcnt. between spring wheat and barley. By Mr. Adam Ruther- 
ford, of poniugton Park. - - - - 56S 

0*en and raolit&ses. By E. T. Waters, esq. - - • 364 

On Swedish turnips. By A.Bacon, esq. - - - ibid. 

E^pcfiments on weeding broad-cast crops. By Mr. J. Wright, of Pick- . 

worth. - - - - - - - ibid. . 

On spring wheat. By the Rer. Mr. Mounsey, ©f Sproxton, nearMeU 

toii 'Mowbray. - - - • S65 , 

On d rah ling. Fy R. Ramsden BramTey, esq. - - - ibid."' 

Oh courses lif crops, and on feeding. By W. N. - - ibid. 

On bcxagorial or Ficnch barley, and on the Swedish or naked barley. 

By IMr. C. VV. S. pHgct, of Pangbourh. - - . 66f 

Oh polled cattle, by the keeper of a few cows at Cheshunt, Ilerti. * 367 

On giddiness and stfurgcrs in sheep. Byll. G. - - ibid. 

On th^ useof lona dung. By J. Bright ley. - - • ibid. 

On the celebrated florin, or butter grass. - - - . 368 

Op fiorin grass. " - ' • - - - - ' ibid. 

Oh the advantages of feeding horses with steamed potatoes instead of 

corn. - - ... . , ibid*^ 

OK^miut in wheat. "By Mr. BatchelAr, of Lidlington. - - 369 

Msch;ue fof washing potatoes and oiher esculent roots for feeding cat- 
Hie. By Mr. W. LtstcT, of Paddingtoii. ^ -' - • - Ibid. 

On ])lanting larch trees. By .T. C. Ciirwen, esq. M. P. - - Srt ' 

Description of a mctliod of packing plants and trees intended for ex- 

poriaiion." By Mr. W. Salisbury, of Brompton. - - S7t 

On planting ash, chesnut, elm, aud other forest trees. . By W. M. \ 

Thackeray, M.D. of Ctiestcr.* - . - - 37-5 

A detail of experiments to ascertain the daily quantity of brown Mus- 
covado sugar necessary to fatten sheep; to shew its effects and ralud 
when 'SO 'applied, *anrt to demonstrate what substance or substances 
'snfTiciently cheap mi^ht be mixed with it, so as to prevent its 
application to common uses, and yet render it not unpalatable 
norpernicious to animals which feed upon it. By the ilev. Dr. 
'Cartwrijiltt. ' u - . - . . 44^ 

Communication! (respecting what Grasses are more particularly 

adapted for meadow grounds, and what for pasture, and whether 

* it is betJer' always to mow, or pasture the ground, cr to mow and 

pasture it in rotati(»n\ By Mr. William Slickney. - - 44f . 

Communications respecting the comparative benefit or injury to the 

hirmer, froaA rooks, pigeons, &c. By Mr, William islickttcy. - 4§# 



CONTENT*. Xi 

. . " ?«?• 

Further commnnicaUons from Mr. Cramp, of Lewes, respecting the 

produce of liis cow. - - « > 45^ 

Essay on tlie fertilizing effects of Gypsum in the United Slates of ^ 
ikmerica, with a view to elucidate its mysterious operation, and 
to extend its benefits to England, and other parts of the Brilisb 
dominions. By M. A. Fortier^Ui, JM. D. F. R. S. of Pkiladtl- 
phia, - - . - - 45i 

Observations oi> the jQat«ral liistory of marl. By R. G. of S. M, 

near Perth, - . . , ^^ 

On the use of sea sliells as a manure. By Domeaticus; - 4.55 

On Ruta Baga. By a Northumberland Farmer. - • 4^ 

Observations on the raisuig of turnip seed. By J. G. F. . ibi^. 

On the cultgre of flax seed. By a Friend to flax seed. . 457 

A new method of yoking horses in- thraulung machines. By Mr. 

John Gladstone. - . ^ J , jy^^ 

On reaping machines. By A. S. . . ^ 45g 

On horse language. By a Farmer. ^ . . i\^^ 

HORTJCULTURB. * 

On the cultivatipn of crocusses, with a short account of jdifferent 
speacs known at present By A, H. Hawort, Bsq. F. US. and 

n. O. - _ _ 



461 



Observations on the .culture of of the dahlias, in the northern parts" 

?*!. ,?r^?"^*"' ^^- >» *^"^' to R- A. Salisbury, Esq. By 
John Wedgewood, of Staffordshire, Esq, . . 

Hints relatiye to the culture of the early purple brocoli, as practised ia 
X?® J o ®" ^^ ^•°**^^ ^^^* ®^- *t Edmonton. By Mr. John Maker, 

An account of the burr-knot apple. In a letter to Henry GrimstOHfl 

esq. By the Rev. John Simpson. - ". ^^ 

On the horticultural management of the sweet or Spanish chesnut^ ^ 

tree. % tire Right Hoji. Sir Joseph Banks, bart, K. B. 

On the proper construction of hot-bed frames. By T. A. Knight, esq. 
X. Jtv. o. occ. - . , . 

A short account ofa new apple, called the Do wijton Pippin. By IV 

A. Knight, esq. F. R. S. - - . . 4^4 

On the managementof the* onion. By the same. • " 4^5 

An improved method of cultirating tl^e Alpine strawberry. BrUie 
same. ' - . _ __ ' * 

^'r^ S Tc""^"^*"^' ""-^^ ^^^^' ®^ ^' ^ ^^^' '^' 
On the forcing houses of tlic Romans, with a list of fruit? c'ultiyated' 

^^uIT^*''"' ^"^ ^^^ ^°"" °^ hpt-hoiisei. By thi ^ev. Ja^es Wil-" 



4iS 

ibid^ 



ibid. 

467 

ibx(t 



CHEMISTRY ano MIipEim-QQT, 

^emical expetiments on brazil and logwood, Bv Mr ChevMal • ah 

On^the metals of potash and soda, ^Mek J^^l^^'^^n^ "^ 

Onthe action o^hosphonis and o|y muriatic acid'gas upon the alkaHcJ ^ 

By Mcwrs. BouiUlon, I^^nge, and Vogel.* ^ . . ,. 



.,,--v, 






CONTENTS, 



On the double refrac^on of the crystals of sulphate of copper. By Mr. 

Prieur. - - - - - - 9? 

On th« manufacture of charcoal in close Tesselt, and on bringing into 
, use the Various substances that are produced in the operation. Bj 

Messrs. MoHerat. - - - - - HX> 

On aconitumuapellus. By Mr. Philip Anthony Steinacher, - lOX * 

.On Syrian asJcpias, as a ])lam that may be used instead of cotton. 
. By Mr. Sonnini. . - . . - lOt 

Kesearch^s and conjectures upon the formation of-metallic Electricity, 

or ^h J is called galvanism. By B. G. Sage. - - lOS 

'On a substance found in the island of Caprea. By Mr. Laugicr. - 10$ 

On a proeessi by which potash and sodamay be metallised without tlie 

intermedium of iron. By Mr. Curaudau. * • - 106 

Chemical expcriroejits on indigo and \road. By Mr. Chevreul. • 107 

On the relation that exisis between the oxidation of metals and their 

capacity of saturation for aeids. By M. Gay-Lussac. - tl3 

Chemicalanalvsis of a black sand from the river Dee in Aberdeen. 

•hire. By Thomas Thompson, M.D. - - - - 114 

On • new kind of fusion, which explains the Formation of Lithoid 

Lava. By Mr. De Dree. ' - - - -17% 

On Arraconile. Bv Mr. Hauy. - - - - IXT 

On Dusodile, a new Mineral 'Species. By Mr. Louis Cordier. - 178 

On potashed Iron. By Mr. Hassenlratz. - ' - ' - ibid* 

On the "Metals of Potash and Soda. By Mes-srs. Gay-Lussac and 

Thenard - - . - - , ' * - 180 

On Apophplite. By Prof R. J. Hauy. - - • 181 

Oa the. tbrmaticiis in which Flint Slate is found. By Mr. J. J. Omft- 

linsD'H^lloy. - - - - - 183 

On artificial Puazo1?.na, oiTarras. By Mr. Gratien Lenere. - 18S 

•Ixp'^rimentb lelative lo Pcta-h au<^ Soda. Py Mr. Kilter, - ibid. 

Analysis of Scapelite, or Faranthine. By Mr. I^ugier. « 183 

On tlie Chahasic, or cubic Zeolite, of the Island of Feroe. By Mr. 

Vaunuelin. ------ 18f 

On the Properties of the new Alkaline Metals. By F. R. Curaudau. ibid. 
/ Description of a Process for determining the Existence of Alumiue in 

the Stones which have fallen upon the Earth. By Mr. B. G. 

Sage. ----,- i8g 

• n the Unwholesomeness of Tea. By Mr. C. L. Cadet. ^ 18^ 

^Experiments on Sulphur, and on its Decompositlont. By Mr. Carau- 

dan. - - - . - - 191 

On violent Pickle, consii^cred as a Test liquor : and of salting Vege- 
tables to preserve them from distillation. By Mr. Descroixilles> 

the elder. - - _. - . . 19;3 

On Chencvrx*8 experiments on Platina, and on those of Detcostils. 

ByMr.C. L. Berthollet. -- - - - 194 

On the existence of oxalic acid in the Leaves and Stalks of Rhubarb. 

By Mr. bouillon Lagrange. - _ ' - _ 195 

On the use of soda in the soap-works at Marbcillcs. By Mr. Lau- 
ren?. - - , - - - - H9€ 
Observations on Cnraudau's experiments on Sulphur, and its Decom- 

^» osition. Dy MeMrr. Vanquelin and Berthollet. ' - - 198 

On the MiTjeralogicGeograpliy ol the neighbourhood of Paris. By 

Messrs.- f'uvier. and Alcicrjuler Brongniart. - • 2t)f> 

Improved Method of preparing Phosphorus bottles. - - 2<>6 

Desf ription of an iroproved A ppacatus for the Decomposition of Potash 

and Soda. By Mr, William Jon«3. - ' «.• . ibtd« 



'«^ -^tSa^Kx 






«•« 



CONTENTl. Xlll 

On a nrw Scvit for a Thermometer. By Mr. Richard Walker. n fOf 
On Conserve of Grape, and iu AppUcataon to making of Wine. Bj 

Mr. Parineutier. - » - • - • ftOI9 

Observations on Caraudau*t Paper on the Influepce which the form of 
fttills exercises on the products obtained, By liCr. BoqiUon La- 
grange. - •- - t - ' - f^O 

On Horse-Chwnut By Prof. Henry, of Paris. - - ftl 

On artrticial Succinic Acid, Lampapias*8 sulphuretted Alkohol, Fe- 
cula, and Cadet's aqueous Solution of Camphor. By Mr. Tromms-* 
dorff. - - . . , - - ft3 

pn a Composition of Ammonia. By Mr. Berthellet. r - 114 

Pescription of a Method of fitting up in a portable Form the Elpc- 
tric Column lately invented by Mr. J. A. De Luc. Also an 
Account of seveiai experiments made wi)h it. By Mr. B. M. 
Foster. ''.•'- ^- . ^ , ■ , fis 

On the Acids produced by treating Qinger Root with nitric Acid. 

By T. Le Gay Brewerton. - - - - S16 

Chemical Analysis of a black Sand, from the river Dee, in Aberdeen- 
shire, and of a Copper oAe, from Arthrey, in Stirlingshire. By 
Thomas Thompson, M. D. - - - - - ibi<). 

IN'ew Klactro-chemical Researches, on various Objects, particularly 
the metallic bodies from the alkalies and earths, and on.some new 
Combinations of Hydrogen. By Mr. Humphry Davy. - flf 

Analysis of Auvite, Melanite, Staurotide, Labrador, Homiblende 
shorlous Beril, reddish Moravian Tourmalme. By Mr. Klap- 
wroth. -.•..» 2j|f 

Analysis of some Minerals, known by the Name of Talc^ By Dr. 
John. -'---- , fSt 

On the Urine of Camels, and that of Horses ; and on the Uric Acid in 

the Excrements of Birds. By Mr. ChevreuL - - fST 

On the oxydizement of Tron. ' By Mr. Hassenfratz. - - f39 

Oil the coagulatiun of Albumen by Heat, and Acids. By Mr. Thenard S4t 

JKew process for preparing liquid Acetate of Ammonia, or Spirit of 

Mindererus. By Mr. Destouches. ... f4j| 

A continuation of the experiments upon the Decomposition of Sulphur. 

By Mr. Cnraudau. - 1 - - - ^ f4S. 

Aialysis of the Datolite. By Mr.Vanquelin. - - - 244 

On the Diminution of the dilatability of Alkofapl in Thermoneten by 

age. By Mr.'Honore Flaugergucs. - - - ibid. 

Observations on the abov^ paper. By Mr. Cottp. - - ibid* 

Additional observatibhs on the.above subject. By Mr. Honore Flau- 
gergucs. - - - ... ibid. 

Qii the Means of determining the Proportion of Acid and Base which 
enters into the Composition of Sulptiate and AJnmine, and in those 
of Sulphate, Nitrate, and Muriate of Potash. By Mr. buraudau. - t4^ 

Observations on Spiuellc-Pleonaste, orCeylonite, and particularly on 
that found in the Neighbourhood of MontpelHer. By Mr. Marcel 
de Serres. - - -■. .'- f 4S 

On Nodules of Lava found in Clinkstone. - - - - 349 

Remarks on the Report made by Vauquelin and BerthoUet respecting 
the Author's two papers on the Decomposition of Sulphur. By F. 
R.Curandao. -* '• - - " - 25(1 

On the Construction and Effects of Pneumatic Tinder Boxes. By Mr. 

Le Bovier Desmortier. - - ^ - . . 251 

Qii making Syrup, brown or white Sugar from Grapes. By Mr. Focque. 254 

Comparative Examination of AI^ Socotrina and Hepatlca. By Mr. 

' Trommsdorif. ... r - - $$7 



%l^ 



<;ONTSlfrf« 



Pag* 

Descrirtion of an Hjgroneter for Cases, and oftlioManne?of using it, 

Bj M:. Gorton Morveau. .- - - - - 25% 

Cb^pa '»tive Exaroiiation of Aloes, Gamboge, Buphorbimn, Myrrh, 

Fia.ikincense, and Guui Ammoniac By Mr. Heurj Braconnot, -^ S5f 

On Muriate of Tin. By Mr. £. Berard. . . , - f 69 

Olbscrvations on Acetic Acid. By Mr. J. B. Molferat. . - 871 

Jteport.niaoe bj a Committee of the Institute, on Mr. CurandaQ'sIast 

Menx>ir. By Mr. Deyenx. - - - - 27S 

On the Preparation of Uqaid Sugar from Apples or Pears. By Mr* 

Dubuc. - - - ... g74 

Analysis of three Vmds of Pyrites. By Mr. Bucholz, « • 276 

Ona PowHersoId a$I{.eca6uanlia. By Mr. Henri. • * 277 

Anatysis r f Biitis i and Foreign Salt, with a vievr (o their fitness for 

economical purposes. By Dr. V\'iHiam Henry. • - ibid. 

On the LoM of Weight which takes place in cooking Animal Food. - 28^ 

On the art of printing upon Stone. - , , . 284 

l^aperiments on sccot'^rine and hepatic al( es. By Messrs. Bouillon, 

Lagrange, and Vo;^^ 1. - , - - - - . 421 

On cystic oxide, a new species of urinary calculus. By Dr. Wm. 
^ Hyde Wollaston. - - '..'.". " *^^ 

Onoxyrauriatic acid, aod on the elements of muriatic acid ; \vith some 

experiments on sutphur and phosphorus. By Mr. Humphry Davy. ' 4S4 
Observations on the researches q£ Messrs. Gay-Lussac and Thenard» 

relative to the amalgam of ainmonia, by Mr. Davy. > . 4S5 

An examination of ^me observations of Messrs. Gay-Lussac and Tlie- 

nard, on the facts relating to the metals from the alkalies, by ]\Ir. H. 

Dary, . - - - - - -, 4$^ 

Qn potasb and toda prepared by means of alkohol. By Mr. Darcet. - 4^9 

On the formation of acetic ether in tbe cake left in pressing grapei. 

By Mr. Derosne. - - • - - - - 45 j 

Kxanmiatioo of the supposed rice payte of China. By Mr. Klapwroth. 463 

On brown hematites, and maiyh ore of iron, &c. - > 464 

A reply to Ifessrs. Gay-Lnssac and Thenard's answer to the Analytical 

Researches, &c. published in the Journ. dc Physique^ fpr December 

1809. By Mr. Humphry Davy. - ' - - - 498 

Answerby Messrs. Gay-Lnssac and Thenard. - - « 5Q0 

On the change of potassium and fodiiun into fixed alkalies. By 

Messrs. Gay-Lussac and Thenard. ... ^^ 

QMnucalexajitination of tlie indigq and woad plants. By Mr. 
. Chevreul. - - - - - .. 506 

On muriatic acid, ancj pxynuriatic ^fld. By Messrs. Tlienard and 

Gaj^Lussac. - ... - §10 

On the combination of gaseous bodies with one another. By Mr. 

Qay-Lussac. - - • - •511 

Chronological Ust of the meteors which have been succeeded by the 

fall of stones or masses of iron. By Dr. E. F. F. Chladui. - 5t4 

On pichbilende, an ore of Uranium. By Mr. Vauquelin. - • 51Q 

pj^Mnription of Diphroitej a new species of mineral. By Mr. Louis 

Cbrdltr. - - * . • « j^^ 



. ••t„ 






RETEOSIPECT 

Of 

PHILOSOPHICAL* MECHANICAL, 
CHEMICAL AND AGRICULWRAL 

I 

DISCOVERIES. 



snsBeateag 



Ho. XXUl.] Janmry^ Fdtuary^ March. [1810. j 



NATURAL PHILOSOPHY, ARTS, ax d MANUFACTURER 



%letJiod of dividing astrmmicat and other InsintmenU, hy ocular 
Iwpecivm^ in which the usu^l Tools for graduating are not etn^ 
phycd ; the whole Operation being so contriredy Jthat no Error 
can occur but what u chargeable to Vision^ when asuisted by the 
best optical means of viewing and measuring minute Quantities^ 
By Ma. Edward TttouGMTON. — Phil. Trans. Part L I8O9. 

iVb conceive that the inerit of Mr. Trougbton's interesting, and, 
\u a scientific point of view, innportant paper, on dividing astro- 
nomical instruments, will be n^ost readily appreciated by a com* 
parison with the methods previously employed for the same pur* 
jose. We shall, therefore, first present our readers with aii 
account of such as he has noticed in the introductory part of this 
communication. , 

Bird, who was justly esteemed the most accurate divider of the 
age in which he lived, owed his reputation chiefly to his contriv-> 
ance for rendering the usual divisions of the quadrant bisectional, 
and the great care he took in* avoiding the unequal expansion from 
change of temperature; His object wa^s to obtain a point upoa 
t'he arc at the hiighpst bisectional number of divisions from 0^ 
-which. he effected b^ the assistance of a fidely divided scale of 
ecuial parts': this, in his eight feet quadrants, was 1P24K85*^0^. 
** The extent, of tb« b^am compasses, with which be traced the 
arc upon the limb of the instrument to be divided, being set oft 
^])on that arc^ gave the points Of. and So*: whichy bting bkected, 

XO. 53,r— vol. VI. B 



f Mr. Troughton's Method of dioi£ng oiironomkal ImtrumaUi, 

give 30^ more to com|ilete the total arc. A second order ^f bi» 
sections gave points at IS^ distant from > each other ; but that 
which denoted 75^ was most useful. Now from the known 
length of the radius, as measured upon the scale, the length of th^ 
chord of 10*^ 2(/ was computed, taken off from the scale, and pro* 
tracted from 75^ forwards ; and the chord of 4° 40^, being ascer* 
tained in tJhe same manner, was sjst off from JK)^ backwards, meet» 
ing the chord of 10^ 3(/ in the continual bisections of S5* 2f/. 
This point being found, the work was carried on by bisections, 
and the chords, as they became^ sikiall eno4igh, were set off^ 
beyond this point, to supply, the Remainder of the quadrantal 
arc. My brother, from mere want of a scale of equal parts 
upon which he could rely, contrived the ^ means of dividing 
bisectionally without one. Mis method I will briefly state, 
m follow*, in the manner whtch it would apply to divtdtng m 
mural quadrant. The arcs of So^ and 30^ give the total are, as 
before; and let the last arc of 30*^ be bisected, and also the last 
ttrc of 15% and again the last arc of 7*^ 3(/. The two marks, 
next $0^ will now be S2^ 30^ and S6^ 16^ consequently the poiut 
•ought ties between them. Bisections will serve us no longer ; but ' 
if we divide the space equally intil three parts, the most forward 
of the two intermediate marks, will give us 8i°, and if we dividt 
the portion of the arc between this mark and S6^ 15^ also into 
three, the most backward of the two will denote SS"^ 25^ Last- 
ly, if we divide any one of these last spaces into five, and set off 
one of these fifth parts backwards from 85^ 25^ we shall have the 
desired point at 1024 divisions upon the arc from 0% All the 
rest of the divisions which have been made in this operation, 
which I have called marks^ because they should be as faint as 
possible, must be erased ; for my brother would never sufier a 
mark to remain upon the arc to interfere, with his future -bisec* 
tions." 

Ramsben s well known method of dividing by the engine, Mr. 
T. says, is capable of so much accuracy and facility, that its nst 
will never be superseded for small instruments, to which it is a* 
\oBfi applica<ble. And he ventures to predict; that the method of 
HindeliQy, described by Smeaton, in the Philosophical Transact 
tious fii^r 1788, will never be brought into practice for dividing 
^Sttronomical instruments. Mr. Troughtein then continues : 
^' The only method of dividing large instruments, now practised 
lA j^oi^don, that I know of, besi4es my own, has not yet, I beKrve, 
been made public. It consists in dividing by hand with beam 
cowpassies and spring dividers, in the, usual wdy; with the addi* 
tion 9f examining the work by microscopes, and correcting it, as 
it proc^eeda, by pressing forwai^dsor backwards by hand, with a fine 
'conit^ljpoint, those dots whicih appear erroneoai^; and thus d^ijust. 
ing them to Uieir proper places, T^e method admits of consi&ritblt ' 



«'♦. 



Mr* Trmf^aonlu M^fM 4fdmding ustrammkal InstrumentM* Z 

•ccoracy^ providad the operator has a steady hand and a good 
eye ; but his work will ever be irregular and inelegant. He must 
have a circular line.passing through the middle of his dots, to en- 
able him to make and keep them at an equal distance from the 
centre. The bisectioi^l arcs, also, which cut them across, de- 
fem them much ; uid, what is worse, the dots which require cor«> 
section (about two thirds perhaps of the whole,) will become 
larger than the rest, and unequally so in proportion to the num« 
^T of attempts which have been found necessary to adjust them. 
In the course of which operation, some of them grow insufferably 
too- large, and it becomes necessary to reduce them to an equali* 
>y with their neighbours. This is done with the burvusher, and 
causes a hollow in the surface, which has a very disagreeable ap* 
pearapce/' After some further remarks, Mr. T. adds, ^^ I will 
now dismiss this method of dividing, with observing, that it is 
iedious in the extreme ; and, did I not know the contrary beyond 
a doubt, I. should have supposed it to have surpassed the utmost 
limit of human patience." 

In Mr. Troughton's method, which constitutes the object 6{ 
dis paper, the surface of the circle which is to be divided, as 
vrell as both its inner and outer edges, particularly the latter, 
jdbould be turned $a true as possible, and a little convex, hav« 
4ngite radius of curvature not greater than one tenth of an inch* 
The roller with which the primary divisions are effected, is a 
littlexonical, baving the diameter of its upper edge, about '001 of 
4an inch greater than that of its lower edge ; the one es^tremity 
b^g too great, and the other too little ; so that it may easily ba 
luljusted to that position where it will measure the arc exactly, 
or tha( it may be carried several times round the circle without 
the error of a single secoud. Experience taught Mr. T. that the 
proportian between the diameters of the roller ^d circle should 
.be that of 1 to l6, or that the former should make one revolutioi^ 
in the space of $2® 30^; and also that the roller should be divid* 
ed into l6 parts ; the absolute equality of these parts is not an 
easential requisite of the division. By this operation, the circle 
will be divided into ^6 parts^ each of ^^hich will correspond with 
an angle upon the circle of l"" 24^ SS^'' * 5, or one 256th part of 
the circle. This number of principal divisions was chosen on 
lurcount of its being susceptible of constant bisection. Two mi- 
cioscopes are used for making the roller exactly measure the cir- 
cle. In the action of the roller, when used to effect these prima- 
ry divisiotis, there are two circumstances worthy of notice ; vif. 
that the roller, in different parts of its journey round the circle, 
measures it unequally ; and that, notwithstanding the inequality 
of these divisions, it should make a second, third, &c. revoluttno, 
without any sensible deviation from its former track. The for- 
iOtr of Ibtse, Mr, T« accounts for, by the metal being more pa- 



4 3fK Traughiants Met%oi ofiicidxiig astrpnomcd Ingtrimentiii 

Tons in one part than in another, and illustrates iht coirrparatitt 
densities by a ploughed field and a gravel walk ; the latter, he 
thinks, arises from the mutual indentation which takes place in 
the surfaces of the roller and circle. The inequality, however, 
of these first divisions, is not of material consequence, as they da 
not fall in with the ultimate divisions, which lire intended to b^ 
equal to 5^ each ; but it is of some importance that the dots be 
all of the same size, concentric, small, axld round. They shoiild 
also occupy a position very near the extreme border of the circle, 
tti give them the greatest radius possible. The absolute atid 
individual errors of the primary divisions are ascertained by th^ 
following ^ery ingenious method, which constitutes a principal 
part of Mr. Troughton's invention. 

■ " The apparatus (by which the 256 dots have been made) 
must now be taken off, and the circle* mounted in thc^ same man* 
ner, that it will be in the observatory. The two tfiicroscopes 
which have ' divided heads, must also be firmly fixed to the sup- 
port of the instrument, oh opposite sides, and their wires brought 
to bisect the first dot, and the one which should be 1 80 ' distiiut. 
'Kow, the microscopes remaining fixed, turn the circle half 
round or until the first microscope coincides with the opposite 
dot ; and, if the other microscope be exactly at the other ddt, 
, it is obvious that these>dots are ISO^ apart, or in the true diap- 
meter of the circle ; and if they disagree, it is obvious that half 
the quantity by which they disagree, as measured by the divi* 
sions of the micrometer head, is the error pf the opposite divi- 
sion ; for the quantity measured is that by which the greater 
portion of the circle exceeds the less. It is convenient to not^ 
these errors + or — , as the dots are found too forward or t^ 
backward, according to the number of the degree; and for the 
purpose of distinguishing the + and — errors, the heads, at 
mentioned before, are numbered backwards and forwards to fifty, 
One of the microscopes remaining as before, remove the oth^ to 
a position at right angles ; and considering for the present both 
the former dots to be true, examine the others by them ; t. e. as 
l^efore, try by the micrometer how many divisions of the head 
the greater half of the scmi<circle exceeds the less, and note half 
l^he quantity + or — , as before, and do the saine< for the other 
semi-circle:. One of the micrometers must now be set at an 
angle of 46^ with the other, and the half difference of the two 
parts of each of the four quadrants registered^ with their respec* 
tive signs. When the circle is a verticle one, as in the present 
instance, ;t is much the best to proceed so far in the exaiivinatioa 
ivilh it in that position, for fear of any general bending or 
spring of the figure; but for the ej^amination of smaller arcs 
than 45^, it will be perfectly safe, and more convenient to have 
it horiaontal ; because the dividing apparatus- will then carry the, 



Mr. Trougkian'^ ifhtkod efUMing iiatrmomical ImhymintH t 

micrometers, severaf perfomtiont being madle in the plat»^^ 
the Hmb to be seen through at proper intervals. The niieroiW 
ters must now be plated at a distance of i2° $(/, and the half 
differences of the parts of all the arcs of 45^ measured and noted 
as bef<yre; thus descending by biseetioas to 11^ 15^ 5^ $7^ ^(^^t 
and ^^ 48^ 46^^ Half this last «|uantity is too small to allow the 
micrometers to b^ brought near enough; but it will have tha 
desired eflect, if tb/ey are placed at that quantity and its half, 
J. f. '4^ 13' 7^^'5 ; in which case the examination, instead of 
being made at the next, will take place at the aejct division but 
one, to that which is the subject of trial. During the whole of 
the time that the examination is made, all the dots, fxcept the 
one under examination^ are, tor the present, supposed to be in 
their true places; and Uie only thing in this most important 
part of the business, from first to last, is to ascertain with the 
utmost care, in divisions of the micrometer head, how much one 
of the parts in the interval under examination, exceeds the other, 
and carefully to calculate the half of their difference. 

The preceding examination furnishes materials for construct- 
ing a table of apparent errors, from which the. true errors are 
next to be computed by the foUowihg rule : let a be the real error 
of the preceding dot, b that of the fullowing ope, and c the appa- 
rent error, taken from the tabl^ of half differences, of. the dot 

* a- + * 
under investigation ; then is -— 1- c its real error," When a 

and b have both the same sign, their sum, bat when they have 
different signs, their difference with the sign of the griiater is to 
be taken, and the same for this new qnantity and c. Of this 
kind of computation, Mr. T. has added some examples ; of which 
the following is one : 

For the point 45^ of the second quadrant« 
Real error of the first point of the quadrant - . X 8*8 • 

Real error of the last point of the quadrant • — 6*9 

Half difference - - ^ - - , - X 09 

Apparent error of the dot under trial ^ • — S'9 

Real error - - - - • — 8*6 

In this way all the errors are computed and arranged in a 
table, which is to be used in dividing the instrument. 

Mr. Trough ton having now completed the' first two sections 
of h;s method of dividing ; vis. that of making the ^56 dots and 
that of finding the errors of these dots and arranging thc^ in 
tables ; he proceeds to a description of the remaining parts of 
his apparatus for completing the true divisions : but for this des- 
cription as well as that of othf r parts of the apparatus, we must 
refer to the plates annexed to the original, from which it will be 
mpch the best understood. We may observe, however, that in order 



€ Mr. TfmgieoBS Mtiinpl of dividing^ 4u(tvii0mittiImermqfU* 

^d obviate the diiiicuUy oiAWidmg the ruiier with a tiifiicieiit ex. 
^Mtae&s to point out upon the limb of the instruinent «pacee corrcs* 
p^pding to others previously divided upon itsdf, Mr. T* has rc^ 
course to a small sector. . '^ The radius of this sector is about four 
times as great as that of the roller, and upon its arc are divided the 
spaces which must be tranferred to theisstrument. One of the an* 
gular spaces upon the circle will beequal to l6 times its correspond- 
ing space upon the sectorial arc, or 20^ 30^; but this does not 
leprefent any number of equal parts upon the instrument^ whose 

subdivisions aVe to be 5^ each ; for is exactly l6j, 

therefore so many divisions are exactly equal to a mean tpac^ 

between the dots whose errors have been tabulated. Let, tfaere>- 

fore, the arc of the sector be divided into \6 spaces of 1° 2(/ 

eaeh, and let a similar space at each end be divided into eight 

parts of ](/ each: w^ shall then have a scale which fumishea 

the means for making the true divisions, and an immediate 

examination at every bisected point/' 

Having described the sector and other parts of the apparatus 

to be used in dividing, Mr. T. next gives directions for their vse 

in the operation ; and a]80 of the alterations that will be neces^ 

sary when the cirele is to be cfivided upon its edge, or a surface 

at ri^ht angles to the usual plane of division. Mr. Troughtun 

likewise subjoins a method of dividing a ciicle according to the 

centesimal division of the quadrant, now used in France. " '* The 

lOOP of the quadrant may be conveniently subdivided into 10 

each, making 4000 divisions in the whole round. The 256 bt<» 

yectional intervals/ the two tables of errors, and th^ manner of 

proceeding and acting upon them, will be exactly the same as 

before, until we come to cut the divisions ; and for this purpose we 

must have another line divided upon the sector. For one 4000th 

part of the circle being equal to 5^*4 of the usual angular mea- 

1° 24^ 22^' '5 
fg^fe , rz 15* divisions ; and just so many will 

5*4 

be equivalent to one of the intervals of the circle. The valu^ of 

one of the great divisions of the sector wiU be 1° 26^ 24^^, and 

that of the ^ parts, which are to be annexed to the right and 

left as before, will be lO' 48''', therefore divisible by the engine. 

Bothgraduations may also be applied. to the same ciicle with very 

.little little additional expense, provided they be both effected at 

the same time." An apparatus is likewise described by which 

the same method of dividing is equally applicable to straight * 

lines. 

Mr. Troughton affirms that the efTects of temperature, during 

the examination of the larger arcs of the instrument, are of much 

greater importance than most workuien will allow ; and main- 

tains, that, while this is effected it is absolutely necessary that 



JfTr. Trougtai^hi Mtiktd of £vidwg ttitronomical rnstrummh* t 

'^the wMe eirdc ftfaould be of the same beat exactly/' In conlir*' 
mattoQ of this asaeriMm; ha obserrar, *' One d^ree of FahrMH 
belt's thermometer indicates (o small a portion of heat, that, i» 
8Qch places as workmen are usaally obliged to do their business 
b, it is aot very easy to have three Cherniometers attached to 
diffe^en^ parts of a large iostrameut^ shewing an equality of tenn 
jierature within that quantity ; yet so necessaiy is cerrectaess an 
this respect, that if a circle has libe vertex one degree wanner 
than its opposite, and if this difference of temperatu>e be gHdm^ 
ally distribated from top to bottom, the upper serntcircle will 
actually exceed the lower by Qf^ : and, if such should happen to 
be the case while tlie examination pf the first dot of the liiiri 
quadrant is made, the regularity of the whok opecation woul^ 
thereby be destroyed*** 

In offering a conoparative estimate of the different method itu 
trodaced in the preceding parts of his papa*, Mr* T. remarks, ^ I 
inow that thirteen dayis, of eight hours each, are well employed 
in dividing such a cirtle by my method ; aboat fifty-two days 
would be consumed in doing the same thing by Air. Bird's nne. 
thod ; and I thii^ I ^cannot err much when i state the method by 
adjustment, supposing every dot to be tried, and that two»thi«da 
of them want adjusting, to require about one liundred and fifty o^ 
such days* The economy of time (setting aside the decided metuw 
of accuracy, which the above estimate of its application ofiers to 
view, wall, I think, be considered of no little mbment* By the 
rising artist who may aspire at excellence, it will at least, and I 
should hope, with latitude* be felt in the abbreviation of his la- 
bours/* 

Several other illustrations are given of various minor paati* 
culars,i>ut for which we must reler such as are interested la the 
Ittbject to the pa|»er iteelfi 



Observaiiong.'^Thert are but few, if any, instances in whkh a 
greater degree 'of science has been employed, or any mecham- 
rd art cultivated with more assiduity, than in the division of as* 
tronomical instruments ; and with what success, the comparative 
accuracy of ancient and modem obaerv^tiboa is a sufficient testi- 
mony. Hie history of this* art, therefore, becomes highly grati* 
^ng, not only. to the artist an^' astronomer, but to' all who either 
delight in the devdopement of truth, or are intorested in the pro- 
gress dfastroDomical science: heoee^ previous to making any re- 
marks relative to Mr* Troughton's n^eUiod, we shalljMida fewhia- 
U^ricfal notites prior to -the time of Bird's invention. 

It has beinasset^ted, and v/e believe upon good authority, that 
tydbo Brahe and Hevetiuf graduated thm oinca instnimffnu, ■ 



S Mr* Troughtms Method of diving astronfifniCc^^ifistritmenfst 

The latter of these astronomers published bis Mackina CaUstiflm 
1673 ; and Dr. Hook wrote btis ammadveirsioas on that work, ia 
' the following year« 

In this last work th« author ba» given a minute description of 
a quadrant, the divisions of which were formed^ and afterwards 
read off by means of an endless screw^ working in the edge of the 
limb, which, he says^ *^ dties not at all depend upon the care an4 
diligei.ce of the instrument maimer, in dividing, graving, or imo)- 
bering the divisions, for the same screw makes it from end to end/ 
The method the Dr. styled " an explication of the new way 
of dividing f and adds that it " excels all the common ways of 
division :'' from which it may be inferred^ that it was tbe first 
attempt- to apply the endless screw and wheel or arcb] to 
the purpose of forming tbe divisions on astronomical instru- 
ments. The artist was the celebrated Mr. Tompion : but 
this method was not found to approach so near to perfection a» 
the doctor supposed ; for^ after a sufficient tiial in tbe conbtruc* 
tion of the sextant with which Mr. f lahisteud made his obser. 
vations at th^ Royal Observatory^ between tbe years I676. and 
}689t it was laid aside, 'i'bis instrument is described in tbe 
Prolegomena of the 3d volume of Historia Ccelestis, and the des- 
cription is accompanied with a iigure. This section, was aft«r- 
waiVls furnished with diagonal divisiuns, distinguishing tbe arch 
into portions of IC/ each, but at first tbe screw divisions wera 
alone depended upon. I'his additional improvement appears to 
have taken place in 1 6*7 7* 

In l689i Mr. Flamstead completed his mural arc at Green- 
wich, in which he was greatly assisted by tbe ingenious Mr. 
Abraham Sharp, his amanuensis^ who was chiefly employed in 
tbe construction of thejciiural arc ; aad which, in the space of 14 
mouths, he finished so much to tbe salisfactitm of Mr. Flam-, 
stead, that he spoke of him in the highest terms of praise, lliis 
celebrated instrument, of which a figure was given at tbe end of 
the Prolegomena, .was of 6 feet 7\ inches radius ; and the divi- 
sions were formed with great delicacy and exactness. About the 
same time the celebrated Danish astronomer Olaus Koemer, laid 
the foundation of his Observatory^ as appears from tbe account 
given by Peter Horrebow, his historian, inserted in the work, 
entitled Basis Astronomias, published in 174U In the same 
tract there is also given a descriptioa of an instrument, which 
not only answered the purpose of a meridian arc, but, a telescope 
being mounted an its axis, it also furnished the first idea of a 
ti*aiisit instrument. But it is the peculiar method which HQemer 
used in dividing bis instruments which tdeierves the chief notice* 
He began at a. given point, and set off tbe required number of* 
equal parts in regular succession, t9 the extent of his arc* For 
«if(^cting this with as. much accuracy aa possible, lie )kKtA tw<s 






Air, Troug/Uon's Method '(^dividing astronomical Instrmnents. 9 

Miff, but fia^ pointed pieces of steel, together, the distance Ik* 
tween the points of which being equal to one of the i,ntended 
divisions in the limb of tde instrunaent, and being l^lOth or 
l-12th of an inch, would answer to about IC' on an arc of 2^ or 
3 feet radius. These divisions were distinguished on the linib by 
very fine dots, and the whole was properly numbered. The sub- 
division of these arches of 10"^ each, was performed by means of 
a double microscope, carried on the radius of thf instruoienty 
having its common fociis furnished with parallel threads of fuigle 
«ilk, eleven of which were disposed at ten equal intervals, ana 
comprehended together one 10' division, the distance of the near- 
est threads became a visible spate^ answering to one minute 
each, and therefore capable,* of a much further subdivision by 
estimation. Hence the divisions on this instrument were not 
degrees and minutes ; but if exactly equal, they were capable ^of 
answering the same purpose, when their true value was found oy 
comparison with larger instruments. This method of division, 
however, was not so susceptible o( being rendered accurate aji 
that of Dr. Hook, by means of the endless screw. 

Mr. Flamstead's instruments being removed by his executors, 
when Dr. Halley was chosen Astionomer Royal, Mr. Grahanl 
nndertbok to make a new mural Quadrant, about the year 17%5^> 
Tbe division of this iiistiiiment he executed with his own hand, 
and united in it all that was valuable in the different methods of 
his predecessors; it was completed with a degree of contrivance, 
accuracy, and precision, before unknown. What appears to be 
peculiar to it was the adoption of an arc of S6 degrees iii 
piefereoce to that of 90^ not only as a check on the arc of de.* 
grees and minutes, but also as being susceptible of the more sim- 
ple principle of continued bisection. He also rejected the subdi. 
vision by diagonals, and substituted that by the vernier in its 
stead ; and this not only rendered the observations capable of 
being read off with all the precision of which the instrument 
would admit, but likewise caused the two sets of divisions to act 
as checks upon each other. Another circumstance peculiar to 
the construction of this instrument was the adoption of the beam 
compass for transferring and cutting the divisions from the origii^ 
nal divided points. Mr. Graham, however, does not seem to 
have beea aware bow great an error may arise from the, unequal 
expansion of different metals, by a variation of temperature ;*for in 
both this instrument and the zenith sector which he constructed 
for Dr. Bradley with so much care and skill, the radii or frames 
were iron, but the limbs were brass. For some years prior to 
the death of Mr. Graham, in 1751, the principal astronomical 
instruments were divided by Mr. Sisson ; and there can be no 
doubt but he was well acquainted M^ith Mr. G.'s method : it was 
oQt of this school also that the eminent Artiit, Mr. Binly arose^ 

xo. 23,— vol. ru c 



\ Mf. Tfovghtofi^s Method of dividing astronomical Jnsitunienh, 

That the are fixed upon bj 6ird, was the greatest in a qua- 
drant which was capable of continual besection into portions of 
5^ each, may easily be showp thus. A quadrant comprehends 
9(f X 60^ or 90 X 1? = 168O divisions, each of which con- 
tains 5^. Now as every bisectional number is evidently some 
power of 2, the greatest power of this integer contained in 108O 
inust be that answering to the greatest bisectional arc ; henct 
1** =;: 103t4; consequently 10^4 -i- 12 = 85° 2(/ the iarc re- 
quired. 

With respect to the subject of this article, it will be considered 
as both curious and interesting by many, while others will regard 
it as highly important and useful ; and the artist in particular 
teust feel himself greatly indebted to Mr. T. for his ingenuous 
^communication. The advantJ^ges of this method are very obvi- 
ous from Mr. T's comparative estimate which we have trans- 
fecribed ; and on this head he also observes : " 'Ilie number 
X>( persons at all capable of dividing originally has hitherto been 
Very few, the practice of it being so limited, that, in less than 
twice seven years, a man could hardly hope to become a work- 
man in this most difficult art. How far I shall be considered 
as having surmounted these difficulties, I know not ; but if by 
the method here fevealed, I have not rendered original di- 
viding almost equally easy, with what copying was before, I 
have spent much labour, time, and thought in vain. I have no 
doubt, indeed, that any careful workman who can dividfe in com- 
mon, and has the ability to construct an astronomical instrument, 
"Will, by following the steps here marked out, be able to divide it» 
the first time he tries, better than the most experienced work« 
man, by any former method." We freely cIjblss ourselves among 
that number of individuals who not only set a high value upon 
tHe integrity and accuracy which Mr. T. has so long exercised 
in dividing instruments of this kind, but esteem that ingenuous- 
ness and love of science which he has manifested on the present 
occasion; and notwithstanding some slight objections which 
might be urged against his method^ we are persuaded that it is 
^e\\ calculated to facilitate the accurate execution of one of the 
ilicest operations of manual labour. 

We are also happy to observe that Mr. Trough ton's liberal 
communication of his mode of dividing to the public through the 
medium of the Royal Society, has gained him the compliment of 
the Copleian medal from the council of that learned bpdy. 



( n ) 



Vn an Improrement in the Manner of dividwg astronomical Insfni* 
ments. By Henry Catendisii, Esq. F. R. S. Phii, Tram* 
PartIL I8O9. 

Ma. Cavendish's object in this communication is to reiQQyt 
-the principal objection against dividing by the beam compa99 1 
and this he thinks may be effected by employing a comp?iS6 witb 
only one point, and a microscope instead of the other, which noay 
be used without setting the point into the division, and conse- 
quently the danger of bruising it ^ill, by this nieans, be completely 
removed. In this method it is necessary to have a steady suph 
port for the compass, and Mr. C. proposes a frame resting upon 
the surface of the circle, when in^a horizontal position, ai^d made 
to slide round it with an adjusting motion, in order that it m^' bf 
easily brought to any required point. The beam comp«^sa turqs 
about an axis, which passes through one of its extremities^ and is 
£xed CO a point in the frame, without the circle, while the other 
end containing the point rests upon a support that can hie easily 
lowered, sp as to suffer the point either to rest upon the circle, or 
prevent it from touching it, at pleasure. A microscope is made U> 
slide from one end of the compass to the other. The distance 
between the centre of the circle to be divided, and the centre 
^bout which the compass turns, must be varied according to th^ 
magnitude of the arc to be divided ; it is therefore most c^Rve^ 
Dient that the piece which supports the centre d of the compaj^ 
should be made to slide nearer id, or further from the centre of 
the circle ; but its distance from it should not be susceptible qif 
variation by the motion of the frame. The end of the compass 
conUinirhg the point, Mr. C. denotes by^; and observes, " this 
being premised, we will first consider tne manner of dividing by 
continued bisection. Let F and / be two points 00 this limbj, 
which is to be bisected in ^. Take the distance of the microscope 
from the point nearly equal to the chord of/^, and place d s^ 
that the point, and the axis of the microseope shall both be in 
the circle in which the divisions are to be cut. Then slide the 
frame till the wire of the microscope bisects the point F ; ap^ 
having lowered the support at ^, make a faint scrc^tch with the 
point. Havipg done this, turn the beam compass round on th^ 
centre d till the point comes to D (another point in the limb pjf 
the circle,) where it must rest on a support similar to that ^t i, 
9nd having slid the frame, till the wire of the microscope bisects 
. ^he point/, make another faint scratch with the point, which, if 
the distance of the microscope from the point has been well taken, 
will be very near tlie former scratch ; and the point midway 
between them will be the accurate bisection of the. arch F f; but 
it is unnecessary, and better not to attempt to place a point be- 
tween these tvro scratches. Having by the^e n\^ns determiiie^ 



it Mr. CavmdUk's h^acemvU U dmUng aarmmkal Intfwnent^ 

the bisection at ^, we must bisect the arcs F ^ and f <p\n just 
the same manner as before, except that the wire df the micror 
scope must be made to bisect the interval between the two faint 
scratches, instead of bisecting a point.". 

When the arc to be bisected is small, a bent point is to be used : 
«r recourse may be had to Mr. Trough ton's method of bisecting 
an odd number of contiguous divisions. The bisections thus oh^ 
tained are not the real divisions, but only marks from which 
these latter are to be cut. For the purpose of making the real 
divisions, the microscope rnust be placed near the point, and d \ 
caused to become a tangent to the circle at J. " The wire of the 
microscope must then be made to bisect onfe of these marks, and 
a point of division cut with the point, and the process continued 
till the divisions are all made." Some precautions necessary to 
be attended to during the operation, are then added ; and it is 
remarked that the entire arc of a circle cannot be divided to de- 
grees without trisection and quinquesectiop : three methods of 
performing the letter are subjoined ; the first of which is the 
following : ** Let a '» be the arch U) be quinquesected.*, open th^ 
beam compass to the chord of one fifth of this arch ; bring the 
microscope to a, and with the point make the scratch /'j then 
bring the microscope to y, and draw the scratch e; and in th? 
same manner make the scratches c^and6. Then turn the beam 
coinnpass half round, and having brought the microscope to a, 
make the scratch j9 ; and proceeding as before^ make the scratches 
7, I ^nd f . 1 hen the true position of the first quinquesection will 
be between h and /3, distant from & by one fifth of 6 ; and the 
second will be distant from ^ by two fifths of dl, and so on.'' 

Mr. C then furnishes directions for subdividing these arcs, and 
making the true divisions ; and enters into the calculation on the 
comparative accuracy of the different kinds of division, which he 
concludes as follows. 

** It appears therefor^, that in trisecting, the greatest error we 
are liable to, does not exceed that of bisection in a greater pro- 
portion than that of 4 to 3 ; but in quinquesecting the error of the 
two middle points is 2 J times greater than in bisecting. It must 
be considered, however, that in the method of continued bisection, 
the two opposite points must be found by quadrisection ; and the 
error of quinquesection exceeds that of quadrisection in no greater 
proportion than that of 6 to 5 ; so that we may fairly say, that 
if we begin with quinquesection, this method of dividing is not 
greatly inferior, in point of accuracy, to that of continued bisec- 
tion." 

As neither of Mr. C's other methods is superior to this in 
point of accuracy, wo shall not describe them. 

^Observatwns.^^ As we agree in the main with the observations 
contained in Mr. Cavendish's concluding paragraph, we sha}| 



/ 

I 



Mr, Lax^ m examining astronomical Instruments. I $ 

transcribe it. He observed : " It is difficult to form a proper 
jodgment of the conveniences or inconveniences of this method, 
without experience ; but, as far as I can judge, it must have much 
advantage, both in point of accuracy and case,* over that of di- 
viding by the common beam compass ; but it very likely may be 
thou^t that Mr. Troughton's method is better than eith«r» 
Whether it ife, or is not, must b^ left for determination to expe- 
rience, and the judgment of artists. Thus much however, may 
be observed, that this, as wellas his, is free from the difficulty 
and inaccuracy of settmg the point of a compass exactly in the 
centre of a division. It also requires less apparatus than his, and 
is free from any 'danger of error, from the slipping or irregularity 
in the motion of a roller ; in which respect this method, notwith- 
standing the precautions used by him, is perhaps, not entirely 
free from objection ; and what with some artists may be thought 
a considerable advantage, it is free from the danger of mistakes, 
in computing a table f)f errors, and in adjusting a sector accord- 
ing to the numbers of that table." With respect to the compari- 
son here alluded to, between this method, Mr. Troughton's, and 
that by the common beam* compass, there may perhaps be difl'e- 
rent opinions. The superior execution of Mr. Trough con's work, 
however, has decidedly shown the preference which his method 
deserves over that by the common beam compass ; and we think 
that '' future experience and the judgment of ai^ists" will also 
prove its superiority to that proposed by the late Mr. Cavendish, 
especially as this latetr gentleman's process requires the tentative 
quinquesection of an arch. 

* ■■.■■ IIIIM ■■ ■ --- II II I II l l I ,11 . I II I 

Oa a Method of examining the Divisions of astronomical Instrw 
ments. By the Rev. William Lax, A. M. F. R. S. FhiL 
Trans. Part IL iSOp. 

At the commencement of this letter, Mr. Lax states some rea- 
sons for the necessity and importance of this examination, and 
then observes, that the instruments which he uses, for observing 
both the altitude and azimuth, are' circles of one foot radius, and 
divided into parts containing ten minutes each. The apparatus 
by which he conducted this examination is next described. That 
for the azimuth circle consists of an arc of brass, concentric with 
the circle, and a little more than 90^ in length ; on this arc slides 
a strong upright pi'ece of brass, bearing at its upper extremity a 
microscope with a moveable wire in its focus, and inclined to the 
left hand in an angle of about 30 degrees. '* The microscope has 
attached to it, a small graduated circle of brass, and an index, by 
which the seconds, and parts of a second, moved over by the wire 
^re detern(uned." The apparatus for ^e vertical circle, it of a 



} 4 itfr. L<Ufi <m ezimmng asironamkol Imtruma^i* 

similar nature ; but some variations are nefceissary on account of 
its position. The process of the examination is this : ^' The'first 
point to be examined is that of 180^ which must be done in the 
usual way, by bringing the points of and 180^ to the moveable 
wires of the opposite micrometers, and then turning the circle 
half way round, and bisecting the points again with the moveable 
wires ; and lastly, taking half the difference betwixt the wlVes, in 
the two position^ of the circle for the error, at the point of 180^. 
Having now bisected the point^of Zero with the moveable wire of 
the micrometer, which is intended to be used in the rest of the 
process (for we shall have no further occasion for both) we must 
slide the microscope along the arc, till by moving the wire a little 
we can bisect the point of 90^ and then the micrometer must be 
firmly clamped to the arc. The circle must then be turned till 
the point of 180° is brought to the microscope, and that of 90* to 
the micrometer, so that we may be able to bisect each by a slight 
motion of their respective wires. This being done, we must ob- 
serve, from the position of the wires, how much the interval 
betwixt them has increased Or decreased in the measurement of 
the new arc ; and this increase or decrease must be noted down 
with a -f- or — accordingly. In the same manner we must pro- 
ceed through the remaining two arcs of 90°, observing and noting 
dowh the difference belwixt each, and the original arc/' An arq 
of 60° is next to be measured against every succeeding arc of 60°, 
in the circle, exactly in the same manner that the arc of §0° was 
measured against the other three. The arc of 4^° fnust then b£ 
measured with each succeeding arc of the same number of de- 
grees, and this will complete all that is necessary to be done in 
the early part of the njoraing, before the heat of the sun can hav« 
affected the tennperature of the instrument. ' The rest may be per- 
nor n^ed at our leisure. 

This process is also to be continued to all the arcs of 30^, 15% 
5% 3% 1% &c. and thence to all the divisions of the circle. 

^' In order to ascerlain the greatest possible error to which ^e 
are liable in the examination, let $ denote in parts of a second the 
jgreatest ,that can be committed in bisecting any point upon the 
limb ; then, since this error may occur at each end of the arc, 
it 18 evident that e (the greatest error) in the expression deduced 

above ( X^ P e ) will become 2 t, and the expression it- 

»— .p 2 I 

self X4 P e. Hence the possible error will be 4 1—2 f 

n 2 

2 c 2—^1 2 

at 180° ;— -- -f -— - X4 I = ^ « at 90*^ 



2 • 2 ' ' 3 ■ 3 

X4i = 3*33 « a^60»; J X 2 i + ^^ X 4 X 2« = 4ii 

3 



Mr. LoTf on examining a$tronomicai In$tnmeniSm 1 5 

at 140^. The greatest error must therefore be betwixt 90^ and 
130**, and nearer to the extremity of the latter than of the former 
arc. At 105° it will be 5.50 1 ; at 111*' it will be 5.50 i — J. 

1-4 f + -- — X 4 X 2 I = 9'70t ; and at 111° lO' it will 
5 

be 9*70 € — J. r04 f (the excess of the error at 111® ab'ovt 
that ai 112**; +3*35 t rr 12*86 i, which will be foutid to be the 
greatest error betwixt 105° and 120°, and of course the greatest 
in the first semicircle. In the other semicircle, the process being 
the same, the possible errors must necessarily be the same, at 
the same distance from the. first point, reckoning the contrary 
way upon the circle. The magnitude of the quantity e will of 
course vary upon circles of the same radius, according to the ex- 
cellence of the glass employed, and the accuracy of the examine/^ 
tye.'' 

There is, however,, very little probability that the error will 
approach near to this extreme limit ; and its probable amount 
may be greatly diminished, by bisecting the respective points 
several times in the measurement of every arc, and taking an 
arithmetical mean of the different readings^ jf for the true position 
of the wire at the bisected point. 

*' Of the time necessary for the examination, a prtetty correct 
idea may be formed, by considering how many measurements are 
required, and allowing about a minute and a half for each ; t. e. a 
quarter of a ininnte for bringing the extreme points of tbe arc, 
to the micrometer and the microscope, and a minute and a quarter 
for making the several bisections. Now, in dividing tba whole 
circle into arcs of 15° each, it will appear that forty-four mea* 
suivments mast be performed, and to examine every point in each 
arc of 15°, there will be 16 1 required, making in all 3908 mea« 
iSurcments ; and consequently the time necessary for completing 
the whole work will be 5^62 minutes, ot about 98 hours. 

" By this method of examination, we ilaay guard against the 
effects of unequal expansion or contraction, by meant of changes 
of temperature ; and either entirely exclude any error, or render it 
too small to be of any importance. Suppose, f^t instance, that 
the arc determined by observation was 48°, then by measuriiig 
it agftitist tlfe whole circumference increased by an arc of M°, 
we sh^Il obtain a result free from any greater error of unequal 
temperature, than one^eigbth of the increase or decrease of tha 
arc of 24% beyond a due proportion to that of the circle itself.' 






Ohertationsm — That an examination of this nature possesses 
considerable importance in contributing greatly to the accuracy of 
astronpmiical observations, without which they are of little value, 
will be rendered sufficiently evident withoui^n>u£h reflectioii ; and 
Mi;. Lax appears to have conducted the procest with laudable 



'«€ peicriptim of a new cupping Ittitpment^ 

perseverance, ingenuity, and skill. By this means he has ret^. 
dered bis simple instruments capable of answering all the ends of 
the French repeating circle, and even of exceeding it in extent 
of application. His comparison on this head is not unworthy 
the attention of our readers, and is as follows ; '* This expedient 
gives us all the advantages of the French circle of repetition, with- 
out the inconvenience arising from being obliged to turn the in- 
strument, and move the telescope so many times in^the course of 
the observation. Nay, I am persuaded .that the result may bt 
made more accurate in this way, than by the French method ; 
because not only can the object be more frequently observed, but 
the contacts or bisections, it may be presumed, will be more exact 
when the observer is not disturbed by the hurry attendant upon 
the use of the repeating circle ; and with respect to any error 
in the instrument, from whatever cause it may arise, it will be 
as eflectually excluded by the process which I recommend, as by 
moving the telescope around the circle. Besides, this method is 
applicable to either the azimuth or altitude, or indeed any circle 
w)iich turns upon its own axis, whereas the French method can 
never be applied to the azimuth circle, nor to any circle which 
does not turn both upon its own axis, and upon one which is per- 
pendicular to it.'' 



^•srss^mmmmmmmimmmmmnim^m 



Description of a new Cvpping Instrument. By Robert HsAtf, 

M. B.-^PML Mag. No. 142. 

This cupping instrument consists of two parts: one of these is 
a close vessel capable of holding about half a pint, made either of 
very thin copper or tin, having a stop.cock soldered into it and 
extending about half an inch within, for the purpose of prevent* 
ing any liquid 'froni issuing from the vessel, when the cock is 
opened. The other part of the instrument is a cupping glass made 
in the 'usual manner, and adapted to the stop.cock by a coarse 
threaded screw. The method of using the instrument is the fol. 
lowing. The glass is to be unscre\yed, a little air drawn from 
the vessel, and the cock turned to prevent its return. Some 
ether or spirits of wine is then to be put in a wine glass, and the 
mouth of the cock immersed in the liquid to such a depth, that 
about a drachm of the liquid may enter the instruments The ves- 
to! is next to be heated, to convert the liquid it contains into va- 
pour, and then the cock being turned to prevent the influx of 
the external air, it is to be immersed in cold water to condense 
the vapour and form a vacuum, which may thus be obtained in 
a few minutes. The cupping glass is next to be screwed into the 
stop-cock, iuui applied to the wound o^ the lancet, &c. a&d 



Mr. CoufeOe on t^c forabolic fjcns «/* ^p^gj^ 17 

the suction reguUted by tuj^ning the ^ock; or if . necessary, 
by unscrewing one turn of tne glass, and permitting the ail-'tb 
enter the vessel through the thread of the screw. 

Obsefvations.^-W e imagine that a dexterous cupper would per- 
form his operation more conveniently and more economically by 
the usual mode of deploying a spirit lamp or a little tow, ttan by 
an apparatus of a more complicated nature. The idea of a secon- 
dary cavity communicating T)y a stop-cock with a. cupping in« . 
struuifnt, is so far from new, that it occuired nearly 2000 year^ 
ago to Hero of Alexandria, and a figure of fiis cbutrivance is ex. ; 
hibited in the Mathematici vcteres. 



On the parabolic Lens ^f Ruspini. Bi, Mr. Couteljle. ^Amu^i 
de Chimiey vol, LXiX. i 

THfs lens consists pf twf> pieces of glass, united together by a 
hoop of iroii, so as to firm a vessel which will ho)d about tweii- 
ty-one gallons of spirits • Its diameter is about 3 feet 3 inciies, 
and its focal distance about j6 fee|; 4 inches. IThe effects of this 
gl^ss are very great. Mr. Jacquin of Vienna, and some oft^er, 
scientific men, who have witnessed them, say t.bat it burned a di-. 
atnond in a fe^y seconds ; and fused platina in a few minutes, A. 
button made of this iftetal^. which weiglved ^9 j^^P?> ^^s melted 
by it, and made in part to boil. Its focus is ab9ut.4 irehch 
lines in dianieter. • ^ ... . 

The lens and necessary apparatus for placing th^ subject .of 
experiment in a proper situation, are mounted on a strong frame ^ 
and made to move with the sun by means of machinery, regulated 
by a seconds pendulum. Its whole weight is about p60 lb, avoir- 
dupois, and wiien caused to incline towards either the east or 
west, it requires a counterpoise to secure its stability. 

J^bis lens is said to have been made at Gratz, in Styria, for 
some alchemists, bv the celebrated mechanist wLose name it 
l]|ears. It was made by softening the glass by means of heat> an^ 
bending it ove? a parabolic mould ; and as several pieces wer^ 
broken before the method succeeded, the original expense wa;^ 
bjBtw'een ,!^0* and 30 thousand franks, or between 800 and 1200 
guineas. ^Ir. Coutelle purchased it for the f reach goverwenl 
for iisbo florins) or 338/. sterling. 

Observations, — Mr. Trudaiue has given an account^ ^ ibf 
Memoirs of Xhe Parisian Academy, of a lens of similar cqi^ 
strupiipja to this which Mr. Coutelle has described. Its diametc^ 
waji It ffict, its focai length about IT; it conuined 140 pintib 
probably Parisian, of spirit of wine* It must have been ntarl/ 

no. 23.— VOL, VI. D 



Iti Mr. Telfirdrs Report on the Okeham and Boston CamU, 

equal, if not superior to this, in power, its diameter being cotisi^ 
derably larger, although not quite in the same proportion as its 
focal length. Mr. Parker's lens of glass, though smaller, seems 
to have been more powerful, its surfaces having been probably 
much more correptly formed : its diameter was 3 feet, its focal 
, length 6 feet 8 inches,' and this length was generally still short- 
ened by a smaller lens : it weighed 213 pounds.— Sc^ Young's 
philosophy, lit 284-, 406, 407. Since the application of oxygei^ 
gas to the blowpipe, such lenses have excited much less curiosity 
than they formerly pierite^. 



sasB 



J^emfrt of a new navi^abk Omalf proposed to be cut from Okeham to, 
Stanford, and frofn'ihence to the to-wn of Boston, jBy Thomas 
Telford, Esq. PhiL Mag. No 142. 

' The town of Okehai^ being situated upon the summit of the 
ridge of land which occupies that part of the copiitry, and from 
which the adjacent streams dcsceud to the river Welland, affords 
ail opjiorturiity of choosing diftereht lines for a canal navigation 
to that river. The river Wash occupies the valley nearest to 
the town of Okeham, anii as it possessed a sufficiently regular 
descent for the required purpose, Mr. Whitwortb, in aforiper sur- 
vey, was induced to prefer the course of that river for the Hne of 
canal to Us junction with the Welland, about a mile and a half 
below Stamford bridge., In this line an inconvenient circuity 
must take place, before it could reach the town of Stamford, and 
Its whole length from Okeham to that place would be about 19 
tailes ; an^ *' in proceeding from the sea coast to the interior of 
the country, the vessels navigating that line, must either pass at 
the tlistance of about one mile and a half from Stamford ; or hav- 
ing come up to the town, most return the same distance, on the 
same line, to get into the valley of the Wash.*' These circum-. 
Stances induce Mr. Telford to think, that this line should be 
tibantloned, and another adopted in its $tead. That which he 
how proposes, is to coqtinue the head \t\t\ along the above 
mentioned line for about a mile and a quarter from Okeham, an(i 
thence, instead of locking down the Wash valley, carry it through 
Egleton into Gunthorpe, and afte:r passing the above valley, tO: 
extend it through the ridge at Martinthorpe, into the valley of the 
Chater. The line is then to be continued down the north side 
df this valley to the most convenient place for crossing the river 
WeHand below the place where the Chater enters it ; and thence^ 
iiividing as much as possible the high land from the low country, 
t(» the river above Stamford bridge. This line Mr. T thinks will 
\t shorter by 4 miks than the preceding one ; it will be more saW 



itfr. Tdforfs Report on the Okeiam and Boston Canal. Ifi 

t'tsfactory to the principal land holders in the county of Rutland, 
it bears more equally upon the general population of that coun- 
ty, and will more directly fix the intercourse by inland naviga- 
tion through the town of Stamford. , 
. From Stamford the canal is to pioceed down the river Welland 
for about three miles, and then depart from the north bank of 
that river, and after separating the uplands and meadows, and 
passing tt) the westward of I'allington, eastward of Barholm, 
land to the west of Kate's Bridge, it is to enter the Car Dyke, 
and be tamed alon^ that ancient work till it approaches the 
iSoiith Forty-foot drain, which it is to enter opposite to Billingbo- 
rough or HorBliogy and proceed along it to Boston. Mr.Telfotd 
then enumerates several important reasons for preferring this 
line olF inland iiavigation between Stamford and Boston to any 
other; and obviated &ome objections which might be urgetl 
against its adoption by the proprietors of other works, through, 
or near which it '\t to pass. He then obsserves : ** In order to 
render the inland navigation of this district of country, and the 
cohbectibns with the interior districts more perfect, and to afford 
a fair competition of local advantages, I am of opinion that a 
canal should be carried between the Welland and the Nene ; and 
the country appears to be particularly favourable for this junc« 
tion. iThis line should depart from \M6 Welland precisely where 
the branch to Boston does, and in a similar hianner thereto. It 
should be carried in a line dividing the uplaild from the flat coun- 
try, and terminating at oir near Peterboidugh. The country 
through'which the canal would pass is very popiilou^, and requires 
communication : ahd the towns and whole population of the val- 
leys of the Welland and the Nene would thereby have an oppor. 
tunity afforded them to benefit by the navigation o'f all the rivers 
which fall into the great Bay — with the choice of sutH of therii 
a& should best suit their interest and coriveniency.^' 

The whole extent of the line embraces an inland navigation of 
from 60 to 70 miles ; and as a great part of it would be carried 
into effect at a small coinparative expense, it affords a fair pros^ 

pect of ample remuneration foi the adventurer^. 

.... , 

bbiervatioits. — The canals already completed in this ( ountry 
have produced great effects upon its culture and general state, 
as well as upon its manufactures and internal commerce. These, 
and the navigable rivers, render the cafriage of bulky articles 
easier, and consequently compairati'vely lei^s expensive. The con* 
veyance of manure, fuel, and several other articles' ihto districts, 
into which they could not atherwise have been transported, has 
tended greatly to the improvement of th^se particular tracts ; 
and the ease with which the produce of the country can be tran^ 
milted to markets^ otherwise tee distant te lie reaeked, hae also 



.J> 



56 Kfr, Ttifor'd's tleport on the Okeham and Boston CauaL 

liad considerable influenceon those markets, and greatly diminuhed 
oad the number of horses that would be necessary for effecting this 
transportation. It cannot, however, be denied, that in several 
places in England, inland navigation has proved injurious to the 
lands through which it is conducted, by obstructing the free pas- 
sage of the rivers to the sea, and frequently overflowing their 
banks, and damaging or destroying the crops in the low grounds. 
Inconveniences of, this kind are sometimes much greater than any 
coinraercial advantage that can be derived from the use of such 
canals, except by a few individuals more immediately concerned 
m them. Similar occurrences, however, may in general be pre- 
vented by a more minute investigation of the consequences 
that are likely to result from carrying this kind of navi- 
gation into effect, and the expense of carriage greatly reduced 
without endangering the best interests of the several districts 
through which they pass. Mr. Telford's object in choosing the 
present line of canal appeal's to have been not only to avoid any 
inconveniences that might result from its execution, but also lo 
render it as beneficial as possible to the adjoining districts ; and 
this proposed line seexhs well calculated to serve both these 
purposes. 

It has been asserted, and we think very justly, that a general 
canal-scheme would tend to equalize the price of every article m 
different and distant parts of this country more than any other 
means, and that canals, calculated for the navigation of boats as 
small as ten tons would be beneficial for this purpose ; these 
might be made at a v6ry reduced expense. In many of the 
marsh and fen districts, most of the present seAvers would require 
but little comparative labour to render them conducive to this 
cnd^ and when a few of the principal ones were constructed, each 
person possessed of extensive landed property would find it his 
interest to make a smaller one through his estate, capable df 
floating boats of about five or six tons. These would afford a 
ready means of conveying both manure and produce from one 
part to another, and therefore, not only promote the improve^ 
ment of general cultivation, but also greatly reduce the number of 
horses necessai*y for agricultural purposes, and permit the land 
required for their maintenance to be applied to other uses. Ca- , 
nals of this kind, we apprehend, might be easily executed in many 
districtSv adjacent to this line from Okeham to Boston, particu- 
larly in the lower parts of it. Mr. Telford's report received the • 
approbation of the committee, who authorized him to proceed 
with the surveys, sections, &c. for furnishing them with all ne- 
cessary data for an application to Parliament for leave to carry 
their plan into execution. 



• • 



( 91 ) 



On aerial Kavigati^. By Sir Gfioacs Cay^et, Bart* Phif, 
. Joum. Noi. 112 ami 113. 

The former part of this essay, descrilnng the general principle 
of support in ai^ridl navigation, we ha^e already noticed, at page 
427 of our fifth voliiiyrt ^ and the author's object in this continu- 
ation is ** to sheir how this principle must be applied, so as to 
be steady and tnanagisable." 1^6r this purpose, be first considers 
the meatis of descent by the parachute, and shews that the com^ 
nion form of that machine, is nearly the worst pois&ible far efiect- 
ing a steady d<tecent,' the end for which it was intended. He 
also shews that the inverted position is that in which it should 
be used for attaining the desired purpose. '^ This angular form 
with the apex downward, is the chief basis of stability in aerial 
navigation ; but as the sheet which is to suspend the weight at- 
tached to it, in its horieontai path through the air, must present 
a slightly concave surface, in a smail angle with the current *; 
this principle can only be used in the lateral extension of. the 
sheet; and this most effectually prevents any railing of the ma^ 
chine from side to side. Hence, the section of the inverted para* 
chute, may equally well represent the cross seption of a sheet for 
aarial navigation,*' The principle of stability in the direction in 
which the machine moves, must be derived from a ditl'erent source. 
If the machine be projected in a horizontal path, with a velocity 
sufficient to support its weight, it will retain its relative position ; 
like a bird in the act of skimming. '* The stability in this position, 
arising from the centi'e of gravi^ being below the point of sus- 
pension, is aided by a remarkable circumstance, that experiment 
alone could point out. In very acute angles with the current, it 
appears, that the centre of resistance in the sail, does not coincide 
with the centre of its surface, but is considerably in front of it. 
As the obliquity of the current decreases, these centres. approach, 
and coincide when the current becomes perpendicular to the sail* 
Hence any heel of the machine backward or forward, removes the 
centre of support behind or before the point of suspensioa; and 
operates to restore the original position by a power, equal to the 
whole weight of the machine, acting upon a lever equal in length 
to the distance the centra has removed." 

From a variety of experiments which the author has made on 
this subject, he conceives that a rudder, similar to the tail of a 
bird, is' necessary both for the purpose of keeping the machine 
steady, and for causing it to ascend and descend in its path« He 
also observes that, ^* the elevation and depression are not the only 
))tttpbBe8 for wnich the* rudder is designed. This appeniiage must 
lM fsrnished with a vertical Sail, and be capable of turning front 
aide to side, in addition to its other movements, which effects the 
4!otli|pilet6 steerafge of the ves^l.'^ 



22 Sir George Cayley An aerial Naoigdtton. 

All the preceding principles are stated to have been abundantly 
verified by experiment, both upon a small and a large scale ; and 
the only thing in this art Which remains - to be determined, is 
the best niode of producing the propelling power. On thia 
subject, however, Sir Geprge says he is prvparing to resume 
his experiments. As conducive to the illustration of this subject, 
he recui's to the flight oi birds, which be analyzes, taking the 
common rook, as before, as the standard of calculatioof and eluci- 
dating his reasoning by means of a diagram. Fiom the premises 
on this head, he draws these conclusions : '* that very acute 
angles vary little in the degree of resistance they make under a 
sinnlar velocity of current ;*' and *^ that the act of flying, when pro^ 
perly adjusted by the Supreme Author of every power, requires 
less exertions than, from appearance, is supposed." 

It is then asserted that sufficient data have not been obtained, 
, for determining the exact propelling power that will be necessary 
for effecting the purposes of aerial navigation, and that the choice 
rests between the direct beat, overtaking the current, like the 
oar of a boat ; or one applied like the wing of a bird in some 
assigned degree of obliquity. It is also concluded, that the ad> 
vantage in favour of the latter method, if it could conveniently 
be put in practice, is nearly as ten to one. 

The author of this essay then states several mechanical diffi- 
culties, which must be overcome before this art can be reduced 
to practice ; but he. thinks that enough has already been done to 
promise ultiipate success. The first of these difficulties is the 
great power which must be brought into action before the nia- 
chine attains that degree of velocity which is capable of support- 
ing it, upon the principle of the inclined plane ; together with 
the total want of all support during the return of any surface used 
like a wing. The second im{>ediment is the great extent of lever« 
on Bccouut of the distance of the centre of support in large sur- 
faces, if applied in this manner. Another obstacle is the mecha- 
nical skill which is requisite to unite a great extent of surface with 
a sutficieiit strength and lightness of structure, and a firm and 
steady movement in all its parts. With respect to the first of 
these difficulties, it is observed that *' there appears several ways 
of obviating it. ^ There may be two surfaces, each capable of sus- 
taining the weight, and placed one above the other, having such 
a construction as to work up and down in opposition when tkey 
are moved, so that one is always ready to diescend, the moment 
the other ceases. These surfaces may be so made Iby a valve^like 
structure, as to give no opposition in rising up, and only to resist 
in descent.** Rotative flyers, or a number of small wings instead 
of large ones, may also be used ; or light wheels may be employed 
to preserve tha propelling power, till it has dofficiently accwm^ 
lated Co elevate the machine. With respect to the great qnantity 
^power thai wili be requisite at 6rst> it is observed tlwt amaa 



Sir George Cayletf on aeriai NaxdgatioH. ft$ 

can exert more power for a few seconds, than twelve men can be- 
stow for a continuance. And it is then added, '' If expansive 
firsi movers be n>ade use of, they may be so constructed, as to be 
capable of doing more than their constant work ; or their power 
may be made to accumulate for a few moments by the formation 
of a vacuum, or the condensation of air, so that these expedients 
may restore at one time, in addition to the working of the en* 
gine, that which they had previously absorbed from it." The 
length of leverage may be counterbalanced by any elastic agent 
which is brought to oppose it ; such as a spring or a cylin- 
der, with a bag piston. Another prmciple that may be applied 
for this purpose is, a construction for causing the air to counter- 
balance itself : this method is then illustrated by a figure* A 
third principle for this purpose of avoiding leverage, is by a mo« 
lion parallel to itself ; and a fourth is that of placing the hinge 
much below the plane of the wing ; or these two methods may 
be combined and carried to any extent. '* A fifth mode of avoid- 
ing leverage is, by using the continued action of oblique horizontal 
flyers, or an alternate action of the same kind, with surfaces so 
constructed as to accommodate their position lo such alternate 
motion ; the hinge or joint being in these cases vertical." 

Sir George then describes a wing which he had constructed, 
for overcoming these general difficulties, and adds; " This fabric 
contained 54 square feet, and weighed only eleven, pounds. Al- 
though both these wings together did not compose more than 
half the surface necessary for the support of a man in the air, yet 
during their waft they lifted the weight of nine stone." The 
means of communicating motion, and the importance of avoiding 
resistance are next considered ; and it is concluded that a man 
in the posture of sitting to work oars probably receives less pn^- 
portional resistance than a crow in the act of flying. This inge- 
nious writer coasidert it ''of great importance to th's art, to a^ 
certain the real solid of least resistance when the length or breadth 
is limited." Newton's beautiful theerem he thinks of no practical 
vse in this ease ; and he offers some remarks relative to the mpde 
of considering the problem, with a view of exciting the atten- 
tion of those who are more competent to its solution. It is con- 
sidered that the shape of the hinder part of this body, is as im- 
portant as the. fore part in diminishing resistance ; and Sir George 
thinks that the moat useful way of ascertaining this figure is by 
experiment ; and the surest path to pursue in this investigation 
is to follow nature ; he therefore proposes to instance the spindles 
of the trout and woodcock in a future communication. 



Observations. -^Th'is paper is a continuation of that which we 
noticed at page 427 of«ur fifth volume ; and as this essay is not 
completed, we shall only offer a few observations of a general na* 
Hire. Tlic fundfMacntal principles of ^erostatiop hi^ve been long 



24 Sir Giforge CayUy on aerial NavigatiDn* 

and generally known, as well as several speeulutions relative ta 
the theory of it; but the successful applicatiou oi: thcde priocipliis 
to practice is entirely of modern date* I'he rapid progress which 
has be^n made in this art, by ihe iew who have employed th^rn- 
selves on the subject, and the degree of perfection which it has 
now attained, ought to be regarded rather as proofs of what may 
be done, than as the consunimatiou of what may bfs expect* 
ei. The nnsucces^al attempts which have been previously 
made to render aerial navigation serviceable to tnankind, ought 
not to furnish any argun>ent tor its discouragement ; while the 
reflection that many arts aild sciences, from which so much be* 
nefit it now derived, were long in attaining maturity ; that tUi» 
resulted only fVom patient investigation, and reiteoiud experi- 
ments ; and from our acquaintance with the ingeniiity and perse^ 
verance of Sir George Cayley, we have some reason to think that 
the undertaking has fallen into good hands. 

We agree with Sir George, that it wpuid be oi great importapce 
to have the solid of least resistance accurately determined. New- 
ton's determination, though true with respect to light, he thinks 
Is not so relative to air ; each particle is supposed (q hav« free 
egress after it has struck the body, which cannot actually teke 
place in nature. The same objectieo may aiso he urged ^g^iost 
most of the other inquiries on the subject. M* Bougu^r, in ^ 
paper published in the Reyal Acadeny of Sciences a^ Peris, has 
solved this problem in a very geeeral manner, witboflt luippo^i^g 
it to be generated by the revolution of any figure whatever, fh^ 
problem as enumerated and solved by him is this ; Any b^e bf ing 
given, to find the solid that must be formsd upon it, so that 
the impulse upon this solid may be the least possible. |t 
should, however, be the retardivf force, or the i^npulse d*« 
vided by the mass, which ought to be the mijoimmn- It 
would also be proper to investigiste that form which yvould af- 
ford the least possible resistance to a body containing a given 
quantity of matter ; this consideration being applicable to the 
case of a body advancing by means of its own iRom^tua^ 
only. 

We conceive the subject to be such as to justify oiur tra^scrib* 
ing the following remarks on the resistance of fiuids from I)rm 
Young's Natural Philosophy, voU ii, page USQ ; and particularly 
so, as that work may not yet be in the possession of niiany of oar 
readers. 

** The first approximation to a detemunetionof the effect ef thf 
resistance, to a body of a given section termieated by ohliqii^ 
planes, is to suppose each particle of the fluid to impinge once oa 
the surface, and then to retire for ever : on this soppesiUop .the 
resistance ought to vary as the square of the cosine of the iftg]!^ 
of incidence. Another part of the resistance is occasioned h^ thfi 
adhesion of the particles of the fluiil ; thb nej be tupf os^ ti> 



Sir Gtorge Cayley on aerial Navigation* $5 

vary, as the product of tht secant and the sine of tbt angle of in-^ 
cidence ; that is, as its tangent. This portion appears, in fact, to 
be but small ; it may however, be taken into consideration, in order 
to facilitate the computation. A third part depends upon 'the 
form of the posterior surface of the body, and upon the unknowri 
irregularities produced in the motions of the particles of the fluids 
by the difference of the forms of its anterior part." It may be ex- 
pected, that the negative pressure will be nearly uniform, when 
the shape of the posterior part of the body remains unaltered. 
Mr. Romme has remarked, that the facility with which the par- 
ticles of the fluid can escape before the moving body, is propor- 
tional to the angular space of the fluid which remains open to 
admit them, and that therefore the resistance must vary in pro- 
portion to this angle. Without allowing the tf uth of the obser- 
vation in its whole extent, we may with propriety inquire, whe- 
ther or not the portion of the pressure derived from impulse may 
not in part depend on some simple function of the angle of inci- 
dence ; and whether the whole resistance to au oblique surface 
may not be considered as composed of a constant portion, a por- 
tion varying with the tangent pf the angle of incidence, and a third 
portion proportionate to. the square of the cosine, diminished in 
the ratio of a power, or other functipn of the angle of incidence. 
And it will appear upon inquiry, that if We take one fifth of the 
radius, increased by one twenty-fifth of the tangent, and add to it 
four-fifths of the square of the cosine, diminished in the ratio of 
the circumference of a circle, increased by the angle of incidence, 
to the simple circumferencCj we may approach always within about 
One-tiftieth, to the number expressing the oblique resistance, until 
the angle of incidence becomes greater thati 80°. Thus, the di- 
rect resistance being unity, and a the angle of incidence, the ob- 
lique resistance will be -^-f .0 4 f . a + 288 (cos. a)* : (SSQ+o'^. 
A formula, somewhat more accurate than this, deduced from ex- 
periment only, is r-z (cos. a/ -|- -000000421 7 a'** ; the quantity- 
added to the square of the cosine being a little less than the 
millionth of the cube' of the angle of incidence, expressed in de- 
grees." 

With respect to the direct resistance to a sphere, the same au- 
thor has observed, that if we divide the square of tht velocity in 
a second, expressed in feet, by l600, we shall have the resistance 
with tolerable accuracy, in pounds avoirdupois, for a sphere afoot 
in diameter, vol. i. p. 306. Now for a buoyancy of 200 pounds^ 
-we shall require a sphere of ai least 20 feet in diatneter, tht re- 
sistance to which will obviously be 400 times as great as to a 
sphere one foot in diameter : and if this sphere be required to be 
propdlcd with a velocity of ten miles an hour, so as at least to 
remain stationary in a gentle breeze, or as Mr. Rouse calls it, " a 
pleasant brisk gale," the velocity being 14$ feet in a second, wt 

NO. 25.— VOL. VI. B 



26 Mr. Newton'^ Machine for chopping Aoots, 3f(f* 



400 



bave 215 for its square, and 215 X coo^^ 54 pounds. Now £l 
labourer, working without disadvantage, can only exert a force of 
about thirty pounds for a length of time, with a velocity of 3 or 
4 feet in a second ; and if it were required that his relative velocity 
should be ten feet with respect to his fixed point of resistance, 
his force must be reduced to about 12 pounds ; and in order to act 
upon the air, the relative velocity must become still greater ; so 
that with the utmost mechanical advantage, it must require the 
labour of at least five men to keep the balloon stationary in such 
a breeze, and probably at least tep if acting against the air only, 
while its buoyancy would only be calculated to raise one of them. 
Undoubtedly the force of birds is applied under circumstances far 
less disadvantageous ; and there is no reason to think it abso« 
lately impossible that at some future time, a man, with the assist- 
ance of a small balloon, may he able to make bis way very tole* 
t'ably through the air, at least in calm weather. 



Machine for Cutting Roots for Cattle, Jrticlcsfor Dyers* use, or for 
culinary purposes. By Mr, Thomas Newton. Trans, iiociefy 
of Arts y vol. XXVII ^ 

In ttiis machine tfie ii>eat is ()ut into a wooden trough, which 
is the segment of a circle, fixed upon a triangular frame that is 
supported by four legs, about the height of a common work bench. 
A short iron axis is fitted to that angle of the frame which is the 
centre of the circle of which the trough is a segment ; this axis 
is forked at the top, forming a joint to which the end of a lever is 
fastened, having fi\^ knives attached to ity by which the meat is 
chopped. The ends of two pieces of wood are fastened to the iron 
axis by the centre pin of the lever; to the other ends of these an 
iron plate is fixed, which rests upon the edges of the trough, is 
perforated with five narrow openings to receive the five knives fix- 
ed to the lever, and acts as a scraper in clearing the knives from 
the meat which would otherwise adhere to them. Two small up- 
right pieces of wood are fixed into those connected witti the iron 
plate, and the knives are prevented from being lifted quite out of 
the openings of the plate by means of a pin passing thiough these 
two pieces. A spring is fixed to the axis, and exerts its force 
against the under side of the lever, and assists in raising it after 
the stroke. As the lever is capable of revolving horizontally about 
its axis, the article in every part of the trough is exposed to the 
action of the knives. The knives are fastened to the piece of 
wood on the lever by bolts passing through them close undei' and 
above the piece to which they are fixed, and when any of them 
want grinding, they can easily be taken out and replaced. The 
^i^ottom of the trough is fastened by screws, so that when it is 



M/-, Brockbank*i Machine for making Slate Pencils. 27 

\yorn by the action of the knives, it can easily be taken out and 
* planed fiat. The length of each knive is equal to the breadth of 
the trough. 

The advantages of this machine, are stated to be a saving of 
labour, time, and waste of meat. And it is added, that " the spring 
raises the knives, and enables any person to chop at least twenty 
times as much meat in the same time as can be done by the com- 
mon mode." ^ 



Observations,-^ \ very slight inspection of this machine will be 
sufficient to evince its utility. It is well adapted to effect a con- 
siderable saving of labour, particularly in preparing sausage meat; 
yet w« think that Mr. N. over- rates its advantage in this respect, 
by"his statement at the close of the preceding account. 



'«■ 



Machine for making Slate Pencils. By Mr, J. Brockbank, 
Trans, Society of Arts, vol. XXV II. 

Motion is communicated to this machinery, by the revolution 
of a small wat<r wheel, on the axis of which cams are ^xed for 
effecting this purpoee. The upper jaw of a pair of pincers is firm- 
ly fixed to a post, and the extreme part of the lower jaw is con- 
nected with one end of a heavy lever by which the pincers are 
opened ; one of the cams fixed on the axis of the wheel, presses 
upon this part of the pincers in its revolution, and closes them, by 
which means the materials are split into slips or lengths, and pre- 
pared for the next part of the process. The pincers are thus open- 
ed and closed alternately, by the weight of the lever and the mo- 
tion of the cam. Another cam fixed to the same axis, imparts an 
alternating horizontal motion to a frame which rests upon the 
general frame of the machine, and impels the pencil through the 
cutter, which is effected by means of chains connected with a wedge 
and wheel placed upon another axis. The cutting instrument con- 
sists of a tube made sharp at one end, somewhat resembling that 
with which sadlers punch holes in leather. This tube should be 
made of good steel ; and after the pencils have undergone this ope- 
ration of passing through the tube, they are passed through a se« 
Qond to reduce them to a proper size for use. 



■W" 



Observations. -^The nature of this species of manufacture is suchj 
that on a superficial view it may, perhaps, appear to occupy so 
humble a place in the scale of importance, as to have little claim 
to the attention of the public ; but we are persuaded that a more 
intimate acquaintance with the subject, will evince this to be 
much stronger than might at first be supposed. The demand 
for pencils of this. kind is certainly very great, extending almost 
to every village in the kingdom. This demand has hitherto been 



2S Mr, Broclibank*8 Machine, for making Slate Pcncilff 

chiefly supplied by importation under the name of Dutch pen-* 
cils ; and considerable sums have annually been remitted Iroin" 
this country for their purchase. Hence any contrivance for sup-? 
plying this consumption from internal sources, becomes an object 
of some consequence, even in a natiohaK point of view; as it nCC 
only renders us more independant of foreign connexions for an ar- 
ticle which is in constant use, but opens a fresh* field for the ex- 
ercise of British industry, and brings a greater capital into home 
circulation, instead of transmitting it to foreign countries; and, 
therefore, as the materials can be considered as of liitle value, the 
invention ought to be regarded as tending to effect a national saving, 
tiearly equal to the whole priinecost of this article. It appears let 
have been Mr. Brockbank's object to invent some mode of hianu- 
facturmg this sort of pencils, which should , render them equal in' 
cheapness, and superior in other respects, to those obtained from 
foreign markets, When the cheapness of the imported pencils is 
considered, this does not seem an easy task ; yet hjs, having been 
induced by the sale of this article to caus6 the machinery for its 
manufacture to be wbrked by water, which was at first only put 
in motion by hand, is g. sufficient proof that he has obtained the 
former of these objects, and the manner in which this is accom- 
plished, leaves no voom to doubt that the latter has been as com- 
pletely surmounted. The Society rewarded Mr. B. with fifteen 
guineas for this commuication. ' 

Machine for manufactunng Silk covered JVire, and Thread covered 
with Silk. By Mr. Thomas SadAnoton. Trans, Society of 
Arts,'9ol, XXVIL 

Mr. Saddington's design in the invention of this machine, was to 
remedy three material inconveniences, which attended the common 
mode of covering wire, v\2. First: The necessity of having work* 
shop^ in gener:al from twenty to forty yards long, consequently the 
purchase or rent of such premises in London must be very consi- 
derable to the manufacturer. Secondly : The disadvantage of 
having the, wire cut into pieces of the length of the workshops, 
for the purpose of covering it. Thirdly : The irregularity of the 
work so made, unless performed by a very steady hand. All the 
^bovc inconveniences are fully obyiated in the present invention ; 
as the machine may be worked in a small room, and the wire 
may be covered of an entire length bf several thousand yards, if 
required, with a certainty of its being regular throughout the work. 
Besides these advantages, it requires only one person to work it, 
whereas in the common mode, two are absolutely necessary. 
These objects, Mr. Saddington effects by a judicious combination 
of wheels, conical pulleys, spindles, rollers, levers, and werghts, 
iixed iu a proper horiBont«^l anci rectangular frame. This ingeni'p 



3/r. Saddmgton's M^chinc/or covering iVire. ^. 

€us contrivance, however, is too complicated to admit of a per- 
spicuous description without its being more extensive than our li- 
rnits wfll allow ; we must therefore refer such of our readers as are 
interested in matters of this nature, to the original communication 
and descriptive drawings, or to an inspection of the model, which is 
preserved in the Society's Repository. Mr. S's description ',)fthis 
machine is aocompanipd with a table for regulating the numbers 
of revolutions in one inch of wire, and with certificates from seve- 
ral gtntlemen engaged in this kind o I manufacture, expressing their 
great approbation of the machine, the novelty of its principle, and 
the accuracy of its work ; and tlie Society rewarded Mr, Saclding- 
ton's ingenuity with a premium of thirty guineas. 



Methods of raising the Bodies of Persons re ho havesujfk under Watery 
or of assisting Persons in Danger in Water, Bt/ John Millir 
Esq. Trans* Society of Arts, vol. XXVII. 

In this communication, i\Ir. Miller describes three machines 
of his invention, for efFerting these desirable purposes, with the 
mode of their application. That which is intended to be used 
in raising the bodies of persons who have sunk under water, consists 
of a round piece of deal, aboi.t ten feet in length, and two inches 
and a half in diameter. At thirteen inches from each end of this 
bar, a square piece of deal is fixed, and made firm by a bracket. 
From this bar four pointed drugs are siispended at equal distances 
from each other. Each of these drags is loaded with two pounds 
of lead fastened to the lower end of its shaft or stem, for the pur- 
pose of steadying it when in use, and preventing its points from 
entering the ground. The opposite effects ot the bar, and these 
weights keep the drag in a proper position when in action. Each 
drag has a swivel at each end of its shaft, anS its whole length is 
about nineteen inches. About the middle of this shaft, are fixed 
three hooks^ which are subdivided at eight inches from their ends. 
^* The} are curved, ahd their points when turned up again are 
abnut four inches below the level of their tops, and thirteen inches 
Asunder; and the outside point of each subdivision, is thirteen 
inches from its adjoining one. The extreme points are split, and 
formed into a double hook, very sharp, and pointing towards the • 
stem." When suspended from the bar, the hooks of each drag are ' 
within about five inches of each other ; those at the ends are lar- 
ger than the others. The drawing rope passes through the swivels 
of all the drags, and through each end of the bar, at the outside of 
the pieces of wood perpendicularly fastened to it. It is then made 
fast by means of wooden wedges, in such a manner, that the two 
•nd drags may be suspended a few inches below the ends of the 
pieces of cross wood fixed' to the bar: the other drags are also 
fixed at the eame distance from the bar. All the drags are madcf 



so Mr. Millers Methods tf raising the Bodifs 

fast to the drawing rope, at equal intervals from each other, and 
prevented from entangling by means of bored pieces of wood 
of equal' lengths, placed between each adjoining pair of drags, 
on a rope which passes through their bottom swivels. The drag^ 
thus fixed in their proper positions have a free rotary motion ; and 
-being separated from each other, only by what will give way, arc 
^ rendered as undulatory in their progress, as the bottom af the wa- 
ter where they are used. For the purpose of either drawing the 
whole apparatus backwards, or releasing any of the drags which 
may happen to get entangled with any object at the bottom of the 
water, another bar of equal lengtli, hut ot less dianfieter than that 
to which the drags arc fixed, is attached to their lower swivels by 
ropes of a proper length. Directions are given for its use, aniJ re- 
lative to the state in which it should be preserved in readiness, or 
conveyed from, one place to another ; and it is also added, that the 
expense 0/ this apparatus is three guineas. 

Mr. Miller also describes two other machines of his invention, 
as closely connected with the subject of life preservation : the 
former of these, he calls a Reel Safegvard, and the latter a Missile 
Hope, The first of these consists of about thirty-five yards of line 
made fast at. one end to a reel, which is about fix inches in dia- 
meter Bnd ten in length". The other end contains 4 ring large 
enough to admit a strong strap to pass through it* Two straps of 
strong Sadler's web, two inches wide, crossing each other, ^.re 
well sewed together, just above the pit of the stomach, and after 
leaving sufi^cient space for the arms to pass through^ the ends on 
each side are fastened together. A ring is fastened to the ends 
behind the left shoulder, and a buckle and strap eighteen inches 
long, behind the right shoulder. This strap is to be passed through 
the ring on the end of the line, and that behind the left shoulder, 
and then buckled to the size of the wearer. By this means, when 
it is usedfor drawing a person out of the water, he is kept on hia 
hack, and his head above water. I'he cost of this apparatus \^ 
eight shillings and sixpence. 

The Missile rope consists of a similar line rendered buoyant by 
means of pieces of cork fastened to it at intervals of three or four 
feet distant from eacli other. It is made fast at one end to ^ 
wooden reel, of a proper size, on which it is to be kept woui.d in 
readiness for use. The throwing end is made fast to a piece of 
wood, shaped like the but end of an oar. It should be unwound 
before it is thrown, that the corks may not be an obstacle to its 
running off the reel in the throw. The cxpence is stated at seven 
shillings and sixpence. 



Observations — On the important subject of both rescuing per- 
sons who are in danger of drowning, and raising the bodies of 
such as have unfortunately sunk under water, a variety of info r- 



of PcrsoTUi sunk undi r IVatcr. Si 

feiation may be fuund in the different volumes of this work. Dr 
Cogan's drag has been described at page 7^ <^f volume iii ; which 
has for some time past been ehleemed the most efficacious utauy 
in use ; but this drag only exteuds over a space of about eighteen 
inches at one sweep, and therefore requires a considerable time t6^ 
search a large space with certainty. What is denominated the 
bar drag, though of greater extent, is incapable of accommoda- 
ting itself to the unevennei^ses in the bottom ; and consequently 
tvlien hollows occur, these remain untouched, though the most 
likely place for the object to lie. It is also an obvious fact, that, 
on these melancholy occasions, any means, to be effectual, must be 
expeditious ; and it was with this object in view that Mr. Miller 
exerted his ingenuity in devising the present apparatus, for which 
he has obtained the gold medal of the society of arls, and merited 
the. thanks of the public. This machine is expeditious, because ex- 
tensive, and secure because the pliableness of its materials adapts 
it to an uneven surface. Mr, Miller's other contrivances, also ap- 
pear ti) be well calculated to answer the intended purposes. 

As accidents of this nature frequently happen, and often prove 
fatal, itls to be feared, for want of proper treatment, a few general 
remarks on the subject will not be improper. It is certain that in 
drowning there is very often such a suspension of the vital powers, 
as has every appearance of their total extinction; yet they may be 
again set in motion, and the person restored to life, after a much 
longer submersion than has generally been thought capable of 
producing absolute death. The length of time that a person may 
remain under water without being drowned, is very unequal willi 
different individuals; and depends upon the temperature of the 
water, as well as on the particular constitution of the sufferer : in 
general, however, there is less prospect of recovery after an im- 
mersion i)f fifteen minutes. In sueh cases death ensues from im- 
peded respiration, and the consequent cessation of the circulation 
of the blood, by which the body loses its heat, and, with that, 
the vital principle. Dr. Goodwyn observes, that the water pro- 
duces all the changes which take place in drowning, only indirectly, 
by excluding the atmospheric air from the lungs, as they admit 
biita very inconsiderable^ quantity of fluid to pass into them, du- 
ring immersion. Hence, the inflation of the lungs is one of the prin- 
cipal means of restoring life. It is, however, a very common and 
dangerous error, and one which deserves to be particularly noticed, 
to suppose that p«rsons apparently dead by immersion underwater 
are irrecoverable, because life does not soon reappear. We there- 
fore seriously intreat those who are employed m this act of hu- 
manity, to persevere in the application of the most approved reme- 
dies recommended by the Humane Society, for three or four liouii 
at least ; for there are many instances on record of sufferers liavin^^ 



32 Mr. Williains 8 Method of securing tie Beami of Ship^. 

recovered after they had been relinquished by all their medica^ 

and other assistants. 



Method 9f securing the Bedms oftShips^ without wooden Knees made 
jnade of one Piece, By Mr. Gkorge Williams. Trans. Soci^ 
eti/ ofartsy tot. XXVI I ^ 

In this method which Mr. Williams proposes for securing the 
beams of ships, triangular braces of wrought iron are to be screwed 
to the upper side of the beamj and also to the sh^.p's side. These 
braces resea^ble the Roman capital A, and are let into the beam, 
and firmly fixed by three bolts ; one near the angular point, and 
two others in the cross part. The ends of these braces are. turned 
up, and b()lted to the tirabcis of the ship's side, by two bolts 
passing through each end and through the timbers and outside 
planks, which secures the beams from lateral motion. In order to 
secure the beams in a vertical direction, a block is fitted under 
each, and mortised both into the beam and the side of the ship. 
Two iron straps are bolted on each blt>ck ; one end of each of 
these straps is fixed to the deck b.eams by the same bolts as the 
upper brace: the other ends are bolted against the inside planking; 
and an oblique bolt goes through the middle of each strap, the 
block, and the ship's side. 

*' In this method less iron in weight, and fewer bolts ar^ neces- 
sary than in the iron knees before in use : there is also less strain 
upon the bolts : In my method much more room is gained be- 
tween decks for stowage and working the guns, and even a port 
hole may be made under the beam." Mr. W. also gives the fol- 
lowing calculation relative to the saving that will be effected by 
this method in a 7^ gun ship, or East India man, viz. 

Ions. Cut. Qrs. lb. j£. s. d. 

Copper bolts 2 1 3 9 at U. 4{f. per lb. 305 8 0' 
Iron 2- 12 Q.i bids, ptr cut. 145 12 O 

Three men and one boy's time for a month ^5 \7 6 

Timber ^ - ..- - -50 00 



I. 546 17 6 



Observations. — The difficulty of procuring a sufficient number of 
wooden knees of a natural form, has long been felt and acknow- 
ledged, and has induced several ingenious mechanics to devise me- 
thods of either diminishing their number br superseding their use 
altogeiher. Of the inventions for these purposes, we have givert 
a summary at page 368, of our fifth volume. In the mode propo- 
sed by Mr. Williams, we regard the block inserted beneath the 
end of the beam is of considerable utility in preventing vertical mo- 



Cqpiain BoltotCs^ Naval Iwpravemfntr. 3!> 

lion: and if Mr. W. be correct in bis calculation relative to the 
saving which will be effected by his method, he deserves a distin- 
guished rank in the list referred to above. The society bestowed 
their silver inedal on Mr. VV, for bis invention. 



Naval Improvements. By Captain William Bolton. Trans^ 

Society of Arts, vol. XXVII. 

Some doubts having arisen relative to the practicability of rig- 
ging thejury masts, invented by Captain Bolton, and noticed al 
page 309 ^>i our fourth volume^ he has transmitted to the Society 
of Arts, d model completely rigged, in order to remove these 
doubts. From this it appears, in tonsequence of the angle being 
more obtuse, that the rigging so placed will give gi eater security, 
supersede the necessity of cathers pinning, and suffer the lower 
yards to be braced sharper up. 

Another of these improvements is a mode of striking the top 
mast, which Captain Bolton has effected by the mahtier in which 
he has fitted the top-mast rigging, " whicb admits of it being set 
Up, almost instantaneously, at any point the mast shall descend 
to; the advantages of which are many^ more particularly when the 
ships are riding hard in open roadsteds.* 

Captain B. has also presented to the Society a model, illuBtra^ 
tive of a plan for fitting up a ship's lower rigging, which is capa. 
ble of being effected by one man. This improvenient "consists 
simply of ascrew attached to each shroud, and tightened by a nut 
under thie channels, which should be well secured by iron clamps, 
or knees for that purpose ; the expense will be far less than in the 
common mode." 

Captain Bolton also requests that the passage which we have 
quoted in the article above referred to, after the full stop at main top, 
be expunged, and the followir^g one be substituted in its stead. 
^'The square fore top mast passes through a cap made from strong 
plank, into the square holes of which the heads of the two tempo- 
rary masts above mentioned are inserted, and the heel of the top 
mast is fidded on the treble trees, or top, as in common, and the 
mast rigged as usually. The object of the strengthening cap it 
to steady the spars, and also serves to fid the top mast on, if 
thought necessary." 

Obsercatiom. — Our readers will easily recollect our sentiments 
on naval inprovem^ts in general, and as readily perceive their 
importance to a nation like this, wliich reigns the undoubted queen 
of the ocean, and whose flags are constantly displayed in every 
quarter of the world. We considered Captain Bolton's former 
communication relative to jury masts as worthy of being attended 

NO. 23. — VOL. VI. r 



34 Captain Bolton*s Naval Improvemenis. 

to by naval men, and he has not rendered it less so, by this addi-* 
tional information. This method of rigging ships in general, and 
bf securing the shrouds, seems to possess some advantages over the 
common modes, and is at least entitled to the ccuisideraiion of per- 
sons concerned iu adairs of this naXuro: and we trust, in whatever, 
relates to this momentons branch of national economy, that cus- 
tom will yield to ieason, and prejudice give way to ntilty. 



Method of constructing commodious Houses which earthen Walls. By 
Mr. Robert Salmon. Trans, Society of jlrts^ voL XXVII, 

Th£ moulds made use of by Mr. Salmon in this kind of building 
fpr the purposeof ramming the earth in, consists of two planks abou^ 
twelve feet long, twenty inches broad, and one inch thick ; such 
being made in two breadths, and strengthened by several, cross 
pieces. Holes are' made through the top and bottom of tbesc 
pieces and the planks, to Receive iron bolts, which hold -the boards 
■ parallel to each other, and at a proper distance for the thickness 
of the wall; which should be about fourteen or sixteen inches. — -' 
These bolts have a large head at one end, and key passing through 
the other, by" which th6 distance of the pianks from each other 
is preserved. The foundation^ of the wall is to be laid with brick 
or stone, and carried about nine inches or afoot above the ground.' 
The planks are then placed upon this wall and bolted together^ 
having pieces of board put in for ends of the mo»ld : these are 
placed betwecii parallel b6lts, passing through the side planks for 
the purpose. The m<juld being thus ^properly placed upon the 
wall, it is to be filled with earth, and properly .rammed down ; 
after which the bolts are to be taken out, the platiks removed and 
put together again upon another length of the wall,- and thearam- 
med with earth as before. But in this case only, one of the end 
boards is necessary, the bolt at the other end passing through 
the holes in the end of the wall which were occupied by the end- 
bolts in the former leilgth. In this manner straight walls may be 
carried on to any length, and when one course is finished, the 
mould is to be placed upon that course, and another completed^ 
and so on to any height required ; always inserting the lower bolts,- 
of the frame through the holes that were made by the upper bolts 
in the preceding cpurse, in order to insure the upper course being^ 
pUiced directly above the former. When the wall is required to* 
be thinner than usual, blocks of wood may he placed under the 
bolt heads, to diminish the distance between the planks to the pro- 
per thickness the wall is intended to be. 

When the angles of buildings are to be formed, four of these 
planks are put together to form a right-angled mould. For this 
purpose, one end of each Qf the inside planks is furnished wit^ .two' 



Afr. SdtnofCs Mtthodof constructing Walls of Earth, 35 

eye-bolts, through which ^holt being passed, forms a kind of hinge, 
and connects the two moulds together ; and these are kept at 
right angles to each other by means of an iron rod hooked into 
eye-bolls fixed in .the planks at some distance from the angle. The 
outside planks are 6xed together diii'erently. One of them is made 
larger than the other, and this has holes near its end to receive 
bolts fastened to the pnd of the shorter plank, which are secured 
on the outside of the longer b}^ k^ys, as usual. ** In building the 
angle wall, it is necessary thja(t the vertical joints formed between 
each mould should not be over one apother, but arranged in the 
same mannei- as in brick work ; this is accom4')lish<Ki by making 
the lower course of wall upon the brick work only half the length 
of the mould, which is done by pfecing the end board of the mould 
in the middle of it. The next course over this is to be made the 
whole length ofthe mould, the next only half, ^nd soon.'* 

After thus describing the moulds and their general application* 
the following particulars necessary to be attended to in the pro- 
cess appear to be too essential to be omitted, and are therefore, 
transcribed from Afr. S.'s. account of his experience. " Having 
carried oiie course round the building, it frequently hapfiens that 
the top thereof becomes too dry to attach to the next course ; and 
therefore it is adviseable that as soon as the frame is set for th« 
succeeding course, a small quantity of thick grout, composed of 
2-5th lime, and 4-6 ths earth, be poured on the topof each course, im- 
mediately before the first layer of earth be put in. A very small quan- 
tity is sufficient, and will add much , to the strength ofthe work, 
by cementing the courses well together at the joints. The work- 
man should also, with the corner ot his rammer, in ramming 
home to the upright joints, cut down a little of that part of the 
wall, up to which he works ; thii will mak« the upright joints 
kty together, and unite in a solid manner. Having thus proceeded 
and got up the walls, the next thing will be to stop the bolt holes, with 
^prtar, made of l-4ith lime, and 3-4ths earth, the same jas the wall. 
*' The earth proper for this work should be neither ^and nor 
clay, but partaking of both. Clay is particularly objecuonable, 
as is also chalk, or calcareous earth of any sort. Sand is also not 
proper, unless accompanied with some binding quahty : the bold- 
er and coarser the sortof earth, the better. When used, it should 
retain no more, moisture than just to make it adhere together, un* 
der thepressure ofthe thumb a!nd finger. Notwithstanding earths 
bordering on sand appear to make the strongest work, neverthe- 
less good earths may oftei^be found in parts that do not abound 
with sand. Those that abound with a mixture of grit or fine 
gravel are generally the best. Havipg provided proper earth, as 
much should be- put in each layer as to form about an inch and a 
half when compressed by ramming. 
*^Thie rammer should not be more than half an inch wide on the 



36 Mr. SalmorCs Method of constructing Walk of Earth. 

edge, in order that it may more forcibly compress every part of 
the earth, which a flat rammer would not do so well. 

'* In making walls, about three inches in thickness of loose 
earth should be put in each course ; which done, the same, by 
means of a trowel made for the purpose, is drawn back and clear- 
ed from the face of the wall, and the space then filled up with the 
facing composition, forming upon an aver^-ge about one inch in 
thickness ; the whole then is firmly rammed (in which, and proper- 
ly preparing the facing stuff, much depends the perfection of the 
work,) till It is quite hard, when it will be compressed to about 
one inch and a half in thickness, rhe common tacing stuff is com- 
posed of lime one part, and earth, the same sort as used for walling, 
three parts. The lime and earth mixed ancj slacked together, the 
same as for mortar. The more it is slacked and wetted, the bet- 
ter, provided time c^n be allowed for it to dry and pulvei^iije eo Ha 
to be fit for ramming. The better sort of facing stuff may have 
a small quantity more lime in it," • 

Mr. S. then offers some further directicms relative to making 
the foundation of brick or stone ; the proper season for performing 
the work, which is any time when the earth can be procured in 
a state ai sufficient dryness for ramming ; and the method of 
forming the spaces for doors, windt)ws, &c. which is to be done 
either by fixing the cross boards of the moulds at the required 
places, or have rough c^es made purposely the size of the win- 
dow, &c. With respect to finishing, he observes that the walls 
of common, cottages may be washed over with lime and sharp 
sand, which should be made up in small quantities, and used while 
hot. ** For better kind of cottages the better sort of facing stuff, 
and tbenjj as before, the whole lime^whited. Qr if i( be required 
to make the finishing, as perfect as possible, the following is the 
best mode, viz. with water and a brush thoroughly wet, and soak 
the face of the wall for tvvo or three yards in superficie at a time ; 
all which part, during the said wetting, should be continually nib- 
bed an4 worked about with a han^ flout, till such time as the sur- 
face is rubbed smooth and even, by which the facing composition 
will work up as to become a pleasant regular colour, the face smooth 
and hard when dry, and not liable to scale off as a coat of plaster- 
ing would do. The finishing will be still improved by a small 
quantity of Hme being put into the water used for snaking the face, 
and if after the wall is. well soaked and rubbed, as above mentioned; 
there be thrown thereon some of the lime and sand, (such as used 
for lime-whiting) and that also worked into the face ; the face will 
then become as perfect and hard as stucco.'* 

" With regard to the expense of wails of this sort, as labour is 
the principal part of the expense, and as in some placed lal>our is 
dearer than in others, the best mode of estimating at di^erent 
places will be from the quantity that a man should do in a day, 



Mr, Salmon's method of constructing Wdh of Earth* 37 

and which I have found to be 1| yard superficial, in thecommo^i 
day's labour of ten hours. 

" At this place (Woburn) the expense maj^ be estimated as fol- 
lows: 

Labour to makins; facing composition, fitting in and £ s. </• 
ramming 10 a 1<) inch wall, where the earth is at hand 
(labourers being 1*. IQi per day) per yard superfi- 
cial . . . . - . --02C 
Value of lime used in the composition rammed into 
the face of a yard superficial (lime being Hd. per bush- 
el)-". O 

Lime and labour to i ubbing up and finishing the out- 
side face of the wall - - ... - 

Total finished and faced on one side. - - 

If a wall to s| garden or other\yis«, and finished and 
and faced on both sides, then add • «. - O S 



3 
O 3 

2 a 



Total for walls finished on both sides. 



P 3 4 



Otservations. — This mode of building strong and durable houses, 
with no other materials th<m earth, has been practised forages In 
the pr 'vince of Lyons, in France. This art, though at present con- 
fined almost exclusively to the Lyonese in France, appears from 
a passage in Pliny's Natural FJistory, to have been known and 
practised at a very early period of antiquity. M. Goiffin pub- 
lished a treatise on thia kind of building, termed Pist\ in 177?, 
in which he gives it as his opinion, that the art was practised by 
the Romans, and by them introduced into Frante. The abb6 
Rozier also says, that he had found traces of it in Catalonia ; so 
that Spain, as well as France, contains a single province in which 
this ancient manner of building has- been preserved. The cheap- 
ness of materials, and other advantages attendii;i[g this art, when 
properly executed, however, render it worthy of being introduced 
into more general use, particularly in those situations where car- 
riage is difficult. or impracticable; and for msiny farm buildings 
•which require to be of considerable extent, and are therefore pro^ 
portionably expensive. Houses thus built will last a great length 
of time ; for M. Francois Coinlei-aux, who composed a work oa 
this subject, says he had pulled down some of them, which ap- 
peared from the title deeds in the hands of the owners, to be more 
than a century old. MAst of the country houses of the rich 
tra4ers and manufacturers of Lyons are of this kind, covered oh 
the outside with painting in fresco. But as paintiiig of this sort 
is little known or practised in this country, we would recommend 
ifaat instead of it, the walls, if not finished after Mr. Salmon's 



38 • Mr. Salmon's Mdkod of constructing Walls of Earth* 

inethod, be plastered and handsomely pebbled, which would give 
the buildings a more rural and neat appearance : or. when this i^ 
not so much an object, we would sugiiest as a more expeditious, 
and consequently « les? expensive mode of pebbling, that the peb- 
bles be regularly mixed with the outside fac ing stuff*, and this 
used iu a rather larger proportion. The plnstering and rough 
casting or dashing, should not be executed for five or six months 
after the walls« are built, or until th^y are perfectly dry ; and to 
prepare them for plMStering they should be closely indented with 
the point of a hammer or other proper instrument. ^ 

The poor in many parts of this kingdom, and even in this 
(country, suffer greatly from the inclemencies of the weather, owing 
to the ^wretchedness of the hovels which they inhi^bit ; the mode 
of building cott^es is so expensive, and, in many places the dif- 
ficulty of procuring the usual materials for that purpose so great, 
than an improvement on this subject is of great in^poitance, and 
Reserves the encouragement of the public. Most of the attempts 
at building in pise which have, at different times, been mad(! iu 
this country, have been unsuccessftil, either through want of dis- 
crimination in the choice of materials, or of skill in the execution 
of the work. Mr. Salmon, however, has not only completely and 
practically overcome the difficulties attending this mode of con,, 
structing comfortable habitations, but has also much improved 
the machinery necessary in thi^ mode of building ; and as his 
essay on this subject is the result of experience ^nd success, it 
deserves to be taken as a guide by those who wish to put this 
method in execution ; and we should be extremely glad if any ob- 
servations of ours be instrumental in facilitating that object. 

As Mr. S. has not said much relative to the earths pr(»per for 
being used in this modt of building, we shall add a few remarks 
on this head. 

All earths may in general be used that do not possess the lights 
ness of poor lands, nor the stiffness of clay ; earths fit for vege- 
tation ; brick earths ; and strong earths, with a n[iix(ure pfsmall 
gravel, which on that account are improper for nv|king either 
bricks, tiles, or pottery, bu| maEe the best pist*. The following 
appearances indicate tha( th^ earth i(i which they are found 19 
fit for a building. When a picliaxe, spade, or plough brings up 
large luflips of earth at a time; when arable land lies in clods o^" 
lumps ; when field mice have made themselves subterranecHis 
passages in the earth ; all these are favourable sign^« When the 
roads are lower than the adjacent parts, and the sides support 
themselves almost upright, it is a sure sign that buildings of this 
}und may be constructed iu that neighbourhood. Proper earth is. 
found at the bottom of the slopes oi low lands that are cultivated, 
as th# rain constantly \^ashes the go,od earth down to these 



Mr. Salmons Method of constructing Walls ofEaM* Sy 

/)Iaces : it is likewise found on the banks of rivers. Earths may 
also be mixed in order to render them more ^t for this purpose. 
Strong earths must be compounded with light; those in which 
clay abounds with such as are chiefly composed of sand ; and 
those that are rich with others of a poor nsiture. It will not be 
amiss to mix with the earth some small pebbles, gravel, rubbish 
of mortar, or any small mineral substances ; but none of the ani^ 
mal or vegetable kind must be admitted. Such haid substance* 
bind the earth lifmly between them ; so that a well worked earth, 
in which there is a mixture of gravel, becomes so hard at the 
*nd of about two years, that it is nearly as difficult to cut as free- 
»tone. 

Experiment, however, in this case as well as in others, is the 
Surest test; and this may easily be effected by taking a small 
wooden tub or box without a bottom, and having dug a hole in 
the ground, and placed a flat stone at the bottom, put in the tub 
or box, and ram the earth dug out of the hole about the outjside 
df it ; then ram the earth interided for the experiment, into the 
tub, in the same manner as is to be practised in making the wall- 
AVhen the tub is full, let it be taken out, and, being left a short 
time to dry, the compressed earth will easily come out of its case. 
The lump is then to be left till it is completely dry, and if it do 
not crack but increase in fiardness, it is fit fot building. A variety 
of earths, when they occur iii the same neighbourhood, as is somew 
times the case, and also their mixtures, may be tried in this way, 
and thafc whiph is most proper for the purpose chosen. 

It has been stated thai a rammer accustomed to the work, 
with the assistance of his labourer, is capable of raising four 
Square yards or thirty-six Square feet of this kind of wall in one 
4ay, which is considerably more than Mr. S's statement allows 
to be effected in the same time. We however fully agree with Mr. 
S. that the soundness and durability of the work depends in great 
measure upon the perfection of the ramming ; and we conceive 
that it is Indispensibly requisite that this operation be continued 
for every layer of earth, till the impression of the ramming in- 
strument be hardly perceptible. It may also be remarked that 
the ramming would be considerably expedited by the use of two 
rammers : one made of any sort of hard wood with^a face much 
broader than that recommended by Mr. S. to be used till thc^arth 
was tolerably compressed, and then the operation completed with 
an ircin one of the kind mentioned above. Besides the advantage 
of cheapness, this mode of buildmg possesses that of being suscep- 
tible of execution by any common labourer, under the directioa 
ef a judicious superintendant. 

For the Indian method of constructing rural buildings of aimi^ 
hr materials, see our Snd volume, page 32, ' 



( *o ) 



On Iris seen in the Dcx, and a lunar Irisy with a?i A/mot at ion, Tt^ 
A. M. Phil. Journ. No. 1 IJ. 

One morning, as the author of this communication was riding 
across a meadow, he perceived on the grass, on that side of him 
opposite to the sun, a beautiful straig^ht line of prismatic colours, 
constituted by the refraction and reflection of the solar light by 
the dew. The line extended from the observer across the mea- 
dow, and formed an angle of 45**, with the show of a vertical 
object. 

A few weeks prior to this, the same gentleman saw, about nine 
o'clock one frosty evening, a beautiful circle round the mooiK 
which exhibited all the prismatic colours, whenever a fleecy cloud 
kitervened between the observer and it. 

Mr. Nicholson, in his 'annotation, remarks that, " the rainbow 
on the groQnd was observed at the beginning of last century by 
Mr. Langwith, Phil. Trans. No. 269; and Mr. B. Martin in his 
Grammar, p. 213, correctly observes, that its figure will be a hy-^ 
perbola, parabola, or ellipse, according to the sun's height. A. M. 
must have seen one of the legs of a ^urve of one of these de- 
scriptions." 

Observatioms^'-^^yt think with Mr. Nicholson, that his corres- 
pondent must have been mistaken with rctpect to the. figure of 
the iris which he saw in the dew, and conceived to be a str.iight 
line ; as from the circumstances by which it was produced, it 
must have been a part of a curve. This will appear evident if 
we consider the rays of light as constituting a coue, having its 
vertex at the centre of the sun ; and the horizontal plane on which 
this iris was seen, as that by which the con^ of light was cut' 
in forming it. When the centre of the sun was in tbe horizon, 
the section made by the horizontal plane would coincide with the 
axis of the cone, and the section evidently be a triangle. In this 
case, however, no iris could be seen. As the elevation of the sun 
increased, the coincidence, or parallelism of the cutting plane, and 
the axis of the cone would be destroyed, and the section for some 
time make a greater angle with the base than the side of the 
cone ; during which period the iris would be a hyperbola. When the 
elevation has attained that degree at which the horizontal plane 
and the upper side of the cone of light are parallel U^ each other, 
the figure of the section would be a parabola; which would im* 
mediately be succeeded by that of an ellipse. Now as the parabo- 
lic figure can only obtain at the moment that the side of the cone^ 
and the cutting plane were parallel, the probability is exceedingly 



Mr. EUk <m the Propagation of Sound through mdastic Fluids. 41 

great, tbat it was not this figure that was seen by Mr. A. M. , 
As this communication is dated Dec. 14ib, when the son does 
not attain any considerable elevation in the early part of the day, 
and it is observed that the phenomenon had been ** lately" ^een, 
ther* can be little doubt that it constituted a part of ow of the 
]e);s of an hyperbola, and not a sfraight line, as was supposed. 
'1 hat this, however, wa» the particular curve cannot be c<»nchnJed 
with certainty, as the precise time of the observation is not men- 
tioned ; which we conceive at all timfes to be au. essential requi^ 
site in things of this nature. 



a=ss 



On the Propagtifion of Sound through uiielastic Fluid*,. By Fr aK« 
CIS Ellis, £.v^. xvitk an Observation by Mr» Nicholson. Phil* 
Joum. No. 1 13. 

Mr. Ellis states that he was bathing in a warm bath atChel^ 
tenbani, and having immersed his head in the water, he was sur- 
prised by a hoarse jtirring notse passing through both ears ; this 
noise he supp»)ses to have resembled what would have been ex- 
perienced it a sheet of tin had been placed over each ear, and 
Btiuck simultaneously with small hammers. ^On examination, 
he found that the water in the hath was heated by steam, con. 
veyed into it by means of a metallic pipe, which entered the bath 
at one of its angles ; and in which the condensation of the steam 
produced at intervals, a dull clicking sound. I'Vhea only one ear 
was immersed in the watery Mr. E. ascertained that it was ibi^ 
sound which he had previously heard, but altered mod augmented 
by passing through the water of the bath from the tube to his 
ear ; a distance of seven or eight feet. Me also remarks, that, 
when his head was submerged, be had distinct, but simultaneous 
sensations of the jarring sound in each eari. 

Mr. Nicholson observes that this noise was of the same nature 
as that of simmering ; and like that also was produced by the collap* 
sion of the water rushing into the vacuum left by tb«^ bubbles of 
steam. He thinks the different sensations which Mr. Ellis expe« 
rienced arose ffom one of his ears being more favourably situ- 
ated for receiving the impressions of the undulatery hiotiou by 
which the sound was conveyed, and which would consequently 
cause one of tbem to receive a stronger action than the other. 
** If this were the case, the sensation ought to have been single, 
when the face was directly opposed to the steam orifice." 

Obserxati(ms. — That sound is capable of being propagated 

through water, is a fact which has long been known; but difle. 

rent opinions appear to be entertained respecting it. Mr. Ande. 

ron^^in the Philosophical Transactions for 174S, states that sound 

.Sua^.— VOL. VI. o 



4$ Mf\ SpfincerU Anthrppo Tdegrap/i. 

is transmitted but faintly tbraygb water, Mr. Hauksbee, in tbei 
same work, relates an experiment wbich l^e made for tbe purpose 
of aec^i tailing tbis point. He surrounded a gla^s receiver ctuH 
taining a bell with water, and on causing the clapper to strike 
the bell, be found that the sound bad lobt very little of its audi, 
biliiy, Hy the introduction of ^be winter i(ito the vessel that con- 
tained the receiver ; but it wsts much more mellpw, sweet* a-^ 
grave, apd ai least two notes deeper than it was before. Mr. 
Kllis fopnd tbe *' dull clicking sound" of the tu|3e changed into a 
^' harsh snapping noise,'' by passing through the water of the 
bath for the space of seven or eight feet. It ought to be remarked, 
however, that there is ^ considerable difference between Hauks- 
bee's experiment and the circumstance related by Mr. Ellis : in 
the former instance the soui^d was transmitted through both watep 
and air, and the thickness of tbe aqueous stratum bore only a 
small proportion to that of the aeriform medium ; in tbe latter, 
the propagation was wholly through water. That t^is circum- , 
stance gave rise to a difference in ^he sound is evident, from thQ 
different sensations experienced by Mr. £• when one of his ears 
was immersed in the water of the bath, and the other remained 
in the air* 



i. Anthropo Telegraph, cr Mode of Commvnic^wn in the Day or 
I^isht^ hi/ Disks. By 3/r. Knight Spencer. Transx Sodcfu 
qf Arts, vol. XXm. 

2» Homograph^ or Method of Cotnmunicafkm by Signals^ on Sea or 
Land* By, Mr. James Spravt. Ibid. 

1. Mr. Sp|:ncci^'^ porta.ble military telegraph censists of ^, 
pair of disks made of basket work, ^bout \S inches diameter, 
painted white \yith a black ball in the centre, weighing about oae 
pound each, ^nd furnished with handles 6 inches in length. A& 
this is the whole apparatus necessary for day signals, th^ expense 
is very trifling. When they are used, the person denominated 
the telegrapher holds one in each hi^nd, and represents the ten 
numerical characters and other requisite signals by displaying 
them in different po§itip|)s. When the signals are to be mada« 
tbe telegrapher^ with a disk in each hapd, puts himself in the 
position of attention, facing the corresponding station, and hold«> 
ing ^he edges of the disks forward. The numbers l^ 2, 3, are 
represented by stretching out the right arm, so as to make angles 
of about 45**, 90®, and 135° respectively, with the body ; while 
the left arm maintains its position close to the side. Ifae nume» 
rals 4, 5, and 6, are denoted by stretching" the left arm in ^ 
similar manner, while the, j^igh^ remains still. To repregei^t 



Mr, SprM^'s HwnQgrapL 4^ 

ft 8y and 9, both arms are stretched at the same tim^ so as to 
make similar aogles ; and the cipher is signified by placing the 
disks one behind the uther^ and htilding them over the head. 
The period which is to be made at the close ol every number^ is 
expressed by bringing ihe ditik in the right hand in front of the 
breast, and placing that in thie left on the back at the same time^ 
in order that it may be seen both ways from the middle stations* 
The signal of communication i« made by the telcgrapbeF.facmg to 
the right, and displaying one of his disks over tbe other : and that 
of error by a union of the positions denoting 1 and 6*. 

As a proof of its simplicity and the ease with which a perfect 
knowledge of it may be gained, Mr. Spencer observes^ that he 
engaged indiscriminately four privates in the South Glouce&ler 
Militia to assist him in making expernnents, and after one hour's 
drill, they made every signal with the utmost correctness. He 
also adds» " my signals, like those used in the Royal Navy, are 
numerical, and of course without limit as to the extent to which 
they may be carried, and with the assistance of Sir Home Pop* 
ham's numbered Dictionary, now generally adopted, every kind 
of communication may be made, and conversations on any sub* 
ject cariied pu at a distance from one mile to three or more, 
according to the circumstance of situation^ weather, &c. with the 
utmost certainty. and telentyi" 

When the signals are to be mad^ at night, a lantern, glazed 
with green stained glass, and furnished with a reflector about 
five inches in diameter, is fixed to the breast of the telegrapher, 
and a smaller one glazed with common glass, is attached to the 
c^htre of each disk, so that it may hang freely iii all pbsitions of 
the disk required by tbe signals. 

i. The simple contrivance which Mr. Spratt has denominated 
ft Homograph consists iA holding a white handkerchief in diiier- 
ent positions \vith respect to the body of the person who holds it ; 
and these positions repn^sent tbe nine digits, with other signals 
in communicatihg by a numleral intercourse. The number 1 is 
denoted .by holding the handkerchief from the right foot to the 
right hand, the arm making an angle of abctut 45^ with the body ; 
5} from the right shoulder to the right hand in the same position ; 
3 whan hbrizontally ; and 4 when further elevated. To denote 
& it is held horizontally above the head ; and 6, 7 9 8, and 9 
foNow in the reverse order to 1,2, 3, and 4 ; while is expres- 
sed by holding the handkerchief horizontally in front. For re- 
pl«9i^nting 1, 5, 9, and 0» the handkerchief should be held, by the 
diagonal corners, as generally prepared for wearing round the 
neck* Bvt for denoting 2, 3) 4, 6, 7> and. 8, the opposite sides of 
the handkerchief should be gathered in each baud, and the near* 
tst extremity of it held to the point of the shouldec The other 
positions are these: the signal of attention, in which tht handker- 



44 Mr, IVhite's File for Receipts and l^^tters* 

chief should be h^ld by two adjacent cornert and displayed <M 
the right side ; the signal of repeat is performed by holding it iu 
front, folded diagonal wise, with the left hand raised, and the 
right depressed. When the hand;kerchief is fdded about the 
right arm and stretched hori^tontally, it expresses an affirmative; 
about the left, a negative : when the right arm is depressed, it 
denotes an interrogative^ and the left iu the same position, signi- 
fies annub 



Observations. — Each of these methods of maintaining a' com* 
toonteation by means of signals is extremely simple ; bat as only 
doe figure ^an be expressed at once, the operation will necessarily 
be much more tedious than when any number can be denoted by 
a single signal, as Major le Hardy's telegraph, described at page 
334 of our 5th volume. Both these, however, possess the advau^ 
tages of j3ortability and cheapness, and will be found to. answer 
Tery well on a great variety of occasions where the other is in- 
applicablfi The latter of these modes is evidently the most 
Simple, and cati be had it! constant readiness iu all places ; but 
the former is more extensive in it» application, as it may be used 
ht night as well as during the day, which the other cannot* 
£a€b is accompanied by certificates bearing testimony to its 
efficacy and to the real inventor i and each was rewarded witb 
the^Silver Medal of the Society. 



■"gg^g— ■ ' ' ■ ' f 'V i ' ■ ■ J" fi ■ " ■" ■■ ^ ■ "■ "^^ 



Improved File fpr Receipts and Letters* By Richard WHiyD, 
Esq. Trans. Society of Arts^ voL XXV I h 

This invention consists of a metal tube with a c'onvex circular 
plate soldered to the lower end of it^ for the purpose, of prevept^ 
ing. the papers from slipping eflf the file. This plate has a piece 
o/ m^tal fixed to the under side of it^ containing a screwed hole 
to receive the end of the wire which passes, through the tube : the 
other end of the wire is* formed into a hookv and made sharp at 
the point to receive the papers as. usual. When any paper is 
required to be- taken off, those above it are. to be slipped up the 
wire above the top of the tube ; the wire is then to be unscrewed 
and taken out with the papers on it, leaving that wantad the up* 
]2ennt)8t of those on t^e tube, which, renders it easy to be takea 
away at pl.easure^ The wire with the other papers is then to be 
returned to its place« and screwed: f«st, as beibre^ The U^\ •! 
the tube should be made conical, and, its edges sharp, \0 
pass mor« easily through the papers which are- to be: put on t<> f 
iu 



CbsnvatiQns*^^^\try persoa who has made use of a comrno* 



jt#r. 6€irl09^t_ikmon4imti<m of the Coteiian T^ortii^. 4A 

fiaper dh^ has felt the inconveniences which this invention of 
Mr. AVhite is intended to remove ; and as it appears effectual for 
the purpose^ we conceive, that there are few persons much con- 
cerned in filing papers, who will hesitate in adopting hi^simpk 
contrivance^ for which the Society voted Mr^ W. their W#c 
Medal. 



r ■ ^ 



5e 



thmonsiration of tie Cbte&lati Theorem* Hy Mr: P. Barlow, 

Phil. Journ. Noi IO9. 

As this curiocis asd elegant property of the circle has ei^gagf d 
the attention of many celebiated mathematicians, without being 
acconi))anied with that success which -has attended many of their 
oth^r pursuits, we shall present oUr msthcmatical readers witb 
such Bn abstract of this demonstration as may just be sufficient 
to enable them to perceive Mr. B/s method. Mr. Barlow com* 
mences his demonstration With the wellkiiown trigonometrical 
property, that if 

Cos. X r^ p 

Cos. 2x ri ^p* — 1 

Cos. 3x re 4p* — $p 

Cos. 4x =: Sp* r- »p* + 1 

Cos. 5x 2: I6y — 120|^ + 5p 
< it^. &c. 

^ 1 

Theii by making 2p tae y + *, imd mtihipfying each of tht 

y 

mbove fonmaim by twis there letulti 

1 1 

2 COS. X ^ y 4 ^ S C4>8. 4x :=: y*. + -■ 

d cos.JbB » / + -r fl cot. 5r ia y* + ~ 

i 



OrgBiiertiHy • • « co«. mx =! ^* + — 

. ym 

' But mf. the getieral form is only deduced from odsc* ving the* 
laiw of the preceding forms,. Mr. J^Krlow endeavours to obtain it 
hi a- more diMttv manner, bf tmniposing and substituting in tbt 
foUowing^ generai formula ; 

Cos. tix tt S cois* X. ct)rf. (n— '1) jt^— eos. (n-*--2) x^ 
saA d^Mii^ thit he* infers tb«ii' ^ ttia^r conclude with certainty^ 



46 Mr. BdrloTv's Dcmdnstration pf the Cdterian. TM^rdh: 

1 

2 COS. X z= y + 

y 

that 2 cos mx = Y°* + — 

ym 

Prom these the two following equations are easily deduced ; 
viz. 

y' -*- 2y cos. X + 1 == 0, 
and >•*■ --.2 y™ cos. mx -f 1 = X) 

Then by substituting qy for y, ^nd the respective values fornned 
in the above forms for 2 cos. x, abd 2 cos. mx ;^ proceeding^ccor. 
ding to the natdre of eqiratioDs,.and the theory of divisors ; and 
niaking use of r to denote the radius of the circle, Mr. B. obtains^ 
as bis results, the folloAvihg foriiiiilae and diviscrrs, viz, 

C ^* y* — 2 qy r cos. Ox + 1 

Formula (q^ y« — r"'), end divisors ^ "1* ^'""^ ^^ I ^^*- ^"^ + J 
^^ J ^^ I q« y« — 2 qy i cos. 4x -f 1 

> &c. &-C. 

!' 9* y* -^ 2 qy r cos. X + 1 
\qy^^(^ TCOS.3X + i 
I q' y* — 4 qy r cos.- 5x + 1 
&c. &c. 

Then by substitution, and Euclid 13^, ^ the8<,are easily showtt 
to be correspondent to the theorem itself. 

Observations.'^ At the beginning of the article. Mr, Barlow ob- 
serves, that it was by following the hints given by Lagrange|#i 
hb *^ Thione des Fmctions j^milj^iquc,'' relative to Ike probable 
circumstances which led Mr. Cotes to this discovery, that he 
arrived at the present demonstration. Notwithstanding the . 
weight which the opinion of Lagrange on this subject naturally 
possesses, we are, however, incHued tor think it equally probable 
that Cotes discovered the truth of this theorem by some tentative 
method, rather than.conducted-'to it by* any Mgiilar pr#c«ss. He 
would easily perceive that it was truc.for squares and tubes, and it 
'is not unlikely tl^at he tried it for one..oc;two oil the higher powers, 
and finding it answer for these also, he. thence inferred its generali- 
ty. This, however, we offer not as a fact, but as a conjecture. 

1 

With respect to the general equation mx = y" + — , we 

said that Mr. B. had endeavoured to prove it direetly ; and this 
we did because we think it was only an endeavour; as it certainly 
is not coBsistent wiih mathematical accuracy to regard any 
thing as legitimately proved when the thing itsetf- caters into the 
proof. We do no^ urge this as doul^ti^g -tl)e trutt pf wibut Mr^ 
S, has inferred ; as we think the law of the exponents of the . 



Pr. Pearsofi's PropMalfor ohtmning an tqual Ttm^raturc. 4? 

leading forms is sufficiently obvious and certain to warrant tlie 
conclusion, and to have superseded the necessity of an attempt 
to prove the general equation, above quoted, in a piore direct 
manner. Upon* the whole, this demons traiion has afforded us 
jnore satisfaction than any other we had previously read on tlie 
the subject. But as it is one in which only a few of our readers 
will feel interested, we shall not extend our remarks, but refer 
such of them as are, to the following works, where they may ob. 
tain much information relative to the elegant theorem and its 
applications. Demoivre*s Paper, in the Philosophical Transac* 
tions for 1722; Dr. Pemberton's Jipist. dc Cotesii Inventis ;'Dr. 
Smith's Theoremata Lagometrica and Trigonome erica, prefixed 
to Mr. Cotes*s liarmonia Mpusurarum ; Demoivre's Miscellanea 
Analytica ; Warrng's Letter to Dr. Powell ; Sinipdon^ Essays \ 
and Lagrange's work, above mentioned* 

■■■I I ■■' — ■■ M il ■ _ II ^ I M . H y I II I ■ .1 I Mill I 

!• Proposal for an Institution for ohtaimng an equal Tcmp^iaturt is 
Houses. Btf p.r, 'rk^\iiso:i, Piiil. Mag. Nq. 140, 

C. On Dr. Pea kson's proposai Jjtr ehtaining an equal Temperature U 
Houses, Bi/CB.sv.Vii.PkiLMa^.No.1^}. 

1. At the con^menpement of t)iis article, Dr. Pearson refers to 
a paper on the same subject, written by him and publiitbec) ill th^ 
IS^th No. of the Philosophical Magazine. In the paper herere* 
ferred to» after enunoer^ting serine of the partial methods that have 
been adopted for this purpose. Dr. P. observes : " All that is fur- 
ther requisite is, to build a dwelling ho^ise of such 4 nature as to 
unite the advantages of diffusing heat by the several modes of its 
communication ; namely, oscillation, alteration of density ^f por- 
tions of air with which it is in contact, and diffusion by elasticity 
or attraction from panicle to particle of i^ir. The plan for such 
a building must be devised by some ing^pious architect, qnder the 
direction of a medical professional man competept{y informed oa 
the subject of the philosophy which furnishes the principle." I{e 
also offers'his assistance gratuitously both iu contriving and sup- 
porting such an institution. . In the present instance, Dr. P. after 
stating his assurance of the advantages which would result fro{u 
such houses, from the success that has attended the rude contriv- 
ances which have already been employed, mentions several re- 
spectably names to whom he has communicated his ideas on the 
subject. He then disclaims all merit of a new discovery, or even 
' of a revival of an old one, and remarks ** I have much pleasure in 
acquainting^ you at this time, that a few days ago an architect of 
great celebrity, and to whom the British public owes many of its 
naost useful works, «Qsured me that he would shortly produce % 



n 



4S Oil Mammg « miU md mitquahk T€m]ier<Lh4r€^ 

grand plan for axacuting my design for the purpoj>es of healthy 
and conjoin a variety of cofDforti, and even some of the luxuries of 
"(he hot cliiiiates." 
. 2. The author of this comotuinication entertains sanguine hopea 
of such a building as referred to by Dr. Pearson being speedily 
erected in this country, and thinks highly of the advantages that 
would re&dlt from it: butobserves, tliat it wirll detraict greatly frotn» 
the satisfaction which such an institution would he capable of af* 
fording, if it be confined exclusively to the use of the ricli. He 
conceives that *^ the remedy of a mild and equable temperature 
may be compassed by persons in the middle station of life, in their 
own houses, aed at au expense not exceedmg what they would of 
necef|ity expend in applications far less efhcacious. The tirst e»«. 
sential seems to be merely a suite of two air-tight apartments and 
an an ti- room opening into each other^ and having do other com?, 
municationwith ther^&t of the house but through the anti-room." 
These apartments ma^ eusily be made air*tigbt by double win- 
dows, doors fitting close and listed, and being well plastered and pa- 
pered, &c. For maintaining an equable teiuperature he thinks 
^hat stoves of all kinds are inadequate, ^id tha]^ the mostxifectu- 
al means would be by the use of sieam^ 

** All that is wanted is a plain and intelligible description of the^ 
mode of its application, which could be practised, by any ordinary 
workman/' Some hints towards the accomplishment of this ob-* 
ject are then suggested ; a^jt is remarked, *' tha.t the great source 
of harm to persons of tender lungs, is the sudden apd great 
changes of temperature, especially from coU ta heat ; which no 
one who stirs 9ut in an English winter can well avoid," Tbis^^ 
however, may be eftected to a ceruio degree by holding a hand^ 
kerchief to the nos« and mouth, to p)*event the air from passing 
into the lungs in its cold s^te ; but Mr. Ceneps thinks that this 
mode canines the breath too much^ and that it might be better 
accomplished by a kind of n^ask, consisting of a light frame fitting- 
close to the lower part of th,Q face, and covered with three or four 
thicknesses of gause. This would admit a sufficient qna^ntity of 
air for respiration, without exposing the lungs to be si» fyr cooled 
as to render it dangerous to enter a warm room or approach a 
fire. In the use of such masks, he thinks there would be much 
less to laugh at than there was in the first use of umbrellas, as a 
roan's lungs are certainly better worth preserving than his coat* 

Observations. -^The beneficial inliuence of a mild andeqnable tem- 
perature, either as a palliative or a remedy for consumptivepatientt ^^ 
has been too long adnnttedand too frequently experienced to req^pre 
any arguments to be used in its favour ; and the number of voy- 
ages that are annually undertal^en to the south of Europe, by such 
sut^rers, is a sufficient proof of the estimation in which it is hcH. 



On counieractmg the Gasscsfimdin Coal Minek. '4lS 

M this «dvaoUge however could be obtained in nearly an equil 
ikgree by lutiiicial means at bome, much painful anxiety wouU 
i)e avoided, and many comlbrts secured .which cannot be expected 
ia a temporary resideace amongst foreigners. That the kao«ry 
ledge of the present pcinod on the subject is adequate to the ertq- 
tion of a building tbat sbaH afford those adva^tc^es in a high de*- 
grefy cannot be doubted ; and we confess that we are sanguine 
.enough to hope for its . completion at no very distant period df 
t:Qie. We, however, are not without apiprehensjiome tliat it would 
only be accessible to certain dasees, or iliat many would prefer a 
lemporary confinement vt their own residesice, under somewhatt 
less favorable circamfttaiDCJas. With auth, tii:.e bin^ts given by Mr. 
ۥ on account of their simple praciicafcHlity^ deserve particular 
/consideration. Steam appears to he the simplest and most ^fhe^ . 
lual agent to he employed iii maintaining ain equable temperature. 
Mr. C. considers enough as haying been, done to shew ite effectui- 
I al application, and that all that is turn .wanted is the Se^t method 

of using it on a ^mall scale for maintaining the air contained ip a 
given space ^t the inquired temperature : and this we regard' as 
an inquiry which is neither uninteresting to the philai^thropif) 
nor unworthy of tlie philosopher, 

I 

— ... i .>.,.,!■.'■!■'.■ ' . ' 1. , '■■■ ..J ,,■■,„' I. ',.1 ,.,'<■ .'. I..LI I I IJ iiJJL 1> 

I 

On the means of cotaiteracting the Effects produced by the For/nfUigip; 
of the Gasses found in CoaUntifies, FhU. JUag, Hfo. l^l^ 

The author of .this communicition observes, " In endeavour- 
I ing to accomplish the important and desirable object before us, 

we ought to addpt those measures which have a tendency to pre- 
' vent the accun^ulation of noxious gasses ; for whenever they are 

suffered to accuniiil ate, there is continual danger. I do* not know 
of any vehicle, neither do I think it possible to devise one, at all 
comparable to that with which nature has wisely provided us, 
namely, atmospheric air." He th.en urges several objection^ 
against the use of chemical reagents for destroying the Jire»dafffp, 
as well as against' other modes which have been proposed for 
avoiding its effectis, and ihen describeii what he conceives tp 
be a more praciicablM and effectual plan, viz. that of ven.tilst-- 
tion. ** V 

The writer commences Ilis. directions with the first opening of 
a mine ; as gasses of this kmd -are frequently met with in sinking 
shafts, being evolved from fisettres in the strata. ** If two shafts 
are sunk near together, ' thrilling Occasionally through from one 
to the other is of great utility : hut in some instances this is by 
no means sufficient to produce the desired effect. Should this be 
the case, air^pipes of large diameter must be extended frpm ih0. 

ISJO; $3»r— VOL. yi. H •- . i 



5Q Ou €ounUr4ieiiMg theGoiut found in Coal Mtna. 

. hHUitn of the sinking shaft, through tjbe.laftt ikriU into the adk 
joiaiiig shafts in the bottom of which, provided it it not deeper 
than the thrill last made, (in which case a scaffold will be naces- 
sacyX a fire must be constantly kept burning : by this ineaas 
pure air will descend the sinking shaft, carrying with it tke 
extricated gfe^ses up the pipes into the adjoining* thqfiy whose 
column of air will be rarified by the fire/- When a communica- 
tion cannot be formed with another shaft, if wooden air-pipes of 
about 15 inches diameter be put down the sinking shaft, and the 
upper ends of them be made to enter the ash pit of the engine 
boiler, properly constructed for the purpose, all the air required 
for carrying on the combustion must necessarily be foroMl up 
- tlie pipes, from the rarefaction which takes place in both the 
ashpit and the engine chimney : hence a cireulation of fresh air 
is kept up. Another method of effecting Ihe same purpose is by 
means of blast cylinders, which are generally constructed to force 
air down the chifiwey ; but this writer thinks the contrary way 
is preferable. 

The shaft being sunk, he pext describes sach meihods ofven^ 
tilation as are adapted to insure the woriiing of the mine with 
safety. It is customary to begin with driving two parallel headi' 
ings or levels near to each other, intersecting the separation by 
thrillSf as often as is necessary ; always taking care tu stop up 
the last but one in succession. One of these levels is denomi- 
nated th^ oir-ipai^, the other the vMggonJway ; and both should 
be made of a sufficient width and height so as to admit a good 
supply of fresh air to carry ofi*the extricated gasses. In forming 
them, the extent and number of air-ways, the area of the q^ipe, 
and the quantity of gasses likely to be evolved, should al]l be tak? 
en into the account. The sides of these should 'be made smooth 
to prevent as much friction as possible, and to admit of -a 
free passage for the air. They should also be made secure^ to 
prevent the necessity of frequent repairs. The thrills should be 
made as large as the air. ways ; and when they are made up, 
great attention should be paid to their being airtight. ^' Doors 
for the purpose of turning the airs should be well made, very 
tight, and firmly fixed. Great care ought to be taken to pre- 
serve the air-ways, &c. in good repair ; and should any part of 
them give way, no time must be lost in securing them, and 
removing the rubbish, that there be no obstruction to free venti- 
lation." 

Great care should be taken that no candles he iiitrutjed in.to 
old cavities, as numerous accidents have happen,ed from this 
cause ; and where there is any danger of fire-damp, the men 
should never work naked. Should any unforeseen explosion take 
place, those in immediate danger should throw themselves down, 
cover themselves as we4 as they can, aqd proceed to that \^^% 



^ On tounicracting the Gooes Jound in Coai Mines. 51 



^i tbe mine^ whence the air is supplied as quicklyandas near 
the ground as possible. When any one is so unfortunate as to 
fall, either from the want of respirable air, or the choke-damp, 
4;veiy exertion should be used to cause the air to circulate 
through the place, that the snfTerer niay be brought out, and 
tb« resuscitating means resorted to with all possible speed. 

Ohservations, — It alWays gives us pleasure to record the judi- 
cious observuittons of practical men on an important snbject; 
from a conviction that this is the source whence the most inte- 
resting information is to be obtained; and that a variety of r^ 
marks of this nature, if properly modified and arranged, would 
form a code of regulations from which the happiest consequences 
might reiiult. Perhaps no class of men among tbe labouring 
rummuniiy are so ignorant and careless as miners, nor aiiy whoiti 
situation and circumstance^ expose to dangers so imminent, or 
T^tonsequences so fatal. Coufined to a narrow cell, surrdutided 
with damps and darkness, with a mind unaccustomed to range 
beyond the precincts of his iipmediaie object, tbe miner is natu- 
rally wedded to tbe prejudices of habit, and disposed to resist, as 
useless innovations, every theoretical caution for his safety. To 
this cause, as well as to tbe inconvenience and expense attending 
their adupta«n, it is to be ascribed, that artificial reagents hsm 
been used either on 'So limited a scale, or with so little success, 
ki counteracting the effects- of what miners eM fire-damp. But 
wh^e this prejudice militates against the employment of artificial 
means-, 4t ^ro>ws the peculiar necessity of using to the gceateat 
<idv»ntage, those which nature has so abundantly placed within 
^ur p3werc and it is in this point of view that we regard the re* 
ftiiark^ i^ the present paper as highly valuable. They appear to 
4>e th« results of considerable experience and observation, digested 
by a mind accustomed toithink closely on the subject of its pttF* 
suits. T^ moti^^ which /the writer assigns for their publi- 
cation is also highly laudable ; viz. <' a desire of putting a sob- 
jectof much impottanea in a train for investigation i' and' w« 
sincerely hope that his example will be followed by other gentle* 
men, whose experience has enabled them to contribute to the 
> stock of practical information, ?o intimately comiected with tbe 
ibining interests of this country^ and rtbe Avelfare of so great a 
number of their fellow-subjects. 



On the Method of transfomdng a Numbef from one Scale of 
JSoiaiion to another^ and its' application to the Rule of Duodeci' 
m(ds. By Mr. P£t£k Baklo^-— PAi/. Joum. No. 119. 

Iif this paper, Mn Barlow first takes a comparative view of the 



ifi Mr. Bartow on the Trathfptmaiiah of Numief*si ' 

Afferent scales of ooUlion. The division of uutnbers itfto petioii 
<«f Itns, he observer, is of very ancient date ; but its use in otir pre^ 
wnt scale of notatiim is a comparatively late improvement, as is 
-4rrideftt from the Urorks of the Greeks, who " employed twtntif^ 
seven, we may say thirty t^six^ different symbols, with which they 
eould not for a long time express a number greater than 10,000 i 
but they afterwards extended it to the square of this number." Th^ 
advantages of ihih notation consist in giving lo each digit a local as 
veU as a simfrie value, and in their increasing in a ten fold pro- 
fiortiOB. Mr. Barlow, however, thinks that either the radix 6 or 
>1S would have better answered the purpose of no^tion, particu- 
:larly the latter number ; but he does not conceive that even this 
Itttter possesses a sufficient superiority over our present mode of 
division to induce us to wish for a change, lie then proceeds to 
fikt method of transforming a number from one scale to another, 
irhich is to be effected in the following manner. 

** Let r be the radix of any system ; and «, b, c, d, SfC. the 
digits by which any number (N) is expressed in that system; then 
we have N=: r"ii + r*-* 6 + ;*"*c -f t^'d, & + 9- 

Thils 1746 in the decimal scale may be expressed by lO' 1 -f- 
Id* 7 4* 10*'4 + 6, and in the duodenary scale, S467 may be re- 
presented by 12**8 4- 12*'4 -f 1^*'6 + 7; and so on for others 5 
twiiere it will readily be t)bserved that the number of characters 
.iBcloding the O, in any s^ale of notation, will nevet exceed the 
:nitthber that expresses the radix of the system/' After some re«- 
i marks relative to the characters of the different systems, and his 
:adoption-of ^ and 7 to represent 10, aiid 11, in the duodenary 
.scale which requires two additional characters ; Mr. B. observes, if 
fl^. be *^ the radix, and a, 6, c, d, and e, the digits in any other system 
vChen in case of equalitv, we shall have j-^a + r"**A 4- »'"**c + r^*d 
i^. CE rf^af H^ r^^ 1/ -f- )/»^«c^, ^-c; and therefore in con- 
Htei^ting a number from one scale, to another, this equation must 
-beCestablished," and solved. Notwithstanding the apparent un- 
liniitedncsss'of this equation, it is of such a nature as'oniy to admit 
^ofdn6possibl^ answer; and this wiU be best obtained ind^pen- 
'diAitly of algebraie consideration, a^ in the following example. 

. To trauiiforni the jromber 7 '^7 i , in the duodenary scale, into 
the decimal notation. 

* H^re 74671 = 1^7 + 1^*4 + l2*-6 + 12. 7 + 1 

And 1^*7 = 145152 

- -... ia'-4. :=, 6912 , 

12«'6 = 864 

V^ .\ lt'7 . =x . 84 

• '..*.-■ *. 1 ■. •.. :=',••! 



!• » 



Therefore 7467 1 =:, 153013 



Mr. Soiiow OH the t^mrfomoH^n of Ifuufberf* \ 5$ 

From this example it will appear ibut d number may be easily 
transformed from any other scale of notation into the decimal scal« 
to which we are accustomed ; hot when the converse of this ki 
required) the operation is more diihcuU, from our want of readioefig 
in the management of the scale into which it is to be converteil. 
For effecting this purpose, Mr, B< givtsthe following 

Rule. ^' In thifi case the given number is always of the form 
10"^ -f 10" '^6 + I0"'^c» 4-c, and the readiest wmy to transform 
•it is, first to convert earb of the powers of 10, begitiAtng wtth the 
lowest, into the required scale, then eaeh of the given terms in thf 
formula into the same, the sum of which will be the answer. 
When it is only necessary to observe that in mil the operations of 
multiplication and addition, we must divide by the radix of tbo 
system, setting down the overplus^ and carrying the quotient 
instead of dividing by 10, as is done in common arithmetic. 

Example, Let it be required to transform 1728 into the duode- 
nary scale. 

First 10 =2 ^ Also I7ad =: 10' -flO'7 + 1012X8 

10*r: (^X^ = «4 8 = 8=8 

TO' = 84 X <^ = 6V4 10-3 = ♦ X 2= 18 

10*= e^i X 9 = 595* 10*-7 = 84 X 7= 4** 
&c. lO'l =6y4 X 1= 6V4 . 



th^efore 17^8 = 1000 Abs. 



Several other examples are given to bivth this and the former 
case, in order to apply what has been advanced to the multipli* 
cation of feet, inches, and parts, &c. by similar denominations, 
the following rule is given. 

'^ Rule* Transform the numbers of feet, if above J 2, into the 
duodenary scale, and set the inches, parts, &c, as decimals ; then 
multiply as in common arithmetic, except, carrying for every 12, 
instead of every 10, as in common operations. 

Example, — Multiply 3 feet, 5 inches, 7 parts, by 3 feet 1 X 
inches, 2 p^rts. 

Here 3-67 

3>2 

3215 
♦49 



«i*Mii*«dMM 



1 2-8542 = 12 feet,8^ 5^4f^ ^*** .• 



O^jfn^AfioM.-^As the <jreek method of notation, to which Mr. 
Bariow has just referred, is very little known in the country, and 
the sources of iBf9][mation oni the subject are both scarce and dif* 
*^ttlt of access, we shall endeavour to give a brief account of it in 



54 Jdf' bariow <m the Trans/brmcUion oj Numbers. 

this place. The superiority of our present system of arithmetic 
over that of the ancient Greeks is so decided ^ to have long sinc^ 
entirely ^superseded the use of their methods ; t-nd the fragmeirts 
of these which still remain upon record, are either scattered over 
woiks which have not been translated, or contained in others, in 
which the translators, on account of the simplicity, as well as ot 
the familiarity bf the arabic characters to both themselves and 
readers, have generally e^cpressed the equivalents to the Greek 
operations in modern characters. Delambre (incorrectly printed 
in Mr. Barlow's paper, Delambert) is the only person, within the 
sphere of our knowledge, who has undertaken to collect these scat- 
tered remains, and to compose a regular essay on the subject. This 
is printed at' the end of the French translation of the works of 
Archimedes, to which we owe the chief part of our acquaintance 
with these ancient, and, in a comparative point of view, imper- 
fect methods. 

The notation of the Greeks, though much less simple than otirs, 
%yas nevertheless very regular : 

Instead of the characters 1, 2, 3, 4, 5, 6, 7, 8, 9, 

they employed the lettiers *---«/?yif^ffld 
Instead of making use of similar letters 

for expressing the tens; they employed ««x f«y|or4^ 
For the hundreds they used f a r v f' x ^ ^ ^ 

And the thousands were denoted by a^y^e i K "^ ^ 



^ i i t I ^ i 



From these examples of their method it appears that tbey had 
recourse to the unit$ in order to express thousands^ with the only 
difference of writing the iota underneath each letter* The con- 
stant relation which subsisted among the four characters in 
each of these vertical columns constitutes a geotnetlcal progres. 
sion, the common ratio of which is 10. 

Thus, for example a, », p, « or 1, 10, 100, 1000 ; 

and ft X, a, or 2, 20, 200, 2000 ; 

and so on for the rest. 
With these characters, they were able to express any number 
less than 10,0000, or a myriad. Thus %i^B signified 9999^ 

^rvfi expressed 7582 ; and ix denoted 4,001. They also some. 

times expressed a myriad, or 10,000, by putting a dash under the 
*, which of itself denoted 10. 

They also expressed any number ol myriads bj the letter M# 
with the number placed above- it : < 

thus * ^ y * 

^^"' M M M M 

denoted 10000 20000 30000 .40000 d-c' 

and j^j signified S7 myriads or 370000, and to on for other num- 



Mr, Barlougn the Transformation of Nitmhfirs. 55 

Jj.ers.of tbe siime kind ; from which it is evident that th« letter ^/ 
placed beneath any number was ec[uivalent to what we effect by 
prefixing lour cyphers to the right hand of the same number. This 
is ihe not^iio^i employed by Euiorius, in his commentaries K)n 
the works of Archlme^Qs; but it was ill adapted to the purposes of 
.computation. 

Diophantub and Pappus made use of the initials Af v placed after 
tbe number to, express the same thing. Thus abAv,fi}lhi^ 7M9, &c. 
implied 10000, SOOOO, 30000, ^c. respectively ; and ^rojSMv 
,«4^ expressed 437^ myriads, 8097 units, or 43728097. This me- 
thod resembles that which we employ to express numbers conv- 
pounded of ditferent denominations ; as yards, feet, and iaches« 
The same authors ali>o employed a still more simple method, thi^ 
was that of using a point instead of the initial Mv ; thus ^to0. ^^ 
jjenoted 43728pC)7, as before^ The Qreeks were thus enabled t^ 
express any number which did not exceed 9999. 9999^ whicti 
they expressed by j9S4^. V^\A : a unit piorie would have made this 
a myriad of myriads ; or according to pur systenii, 100,000,000 
^ 10000^ or a hundred millions. This aujQl.)€r i.ii^n;iited the no- 
tation of the Greeks, until Archimedes ^ippri^ed it to be taken for 
a new unit ; and the numbers foun^ of tl^ese last, he called num- 
bers of the second order. Jn this manner he expressed all tbe 
numbers which in our systeip require X6' cyphers to express them. 
Then taking for another jiew unit, the unit followed by iS 
noughts, or the 4th power of the myriad, he composed numbers 
of the third order. A uttit^followed by 24 noughts, or the sixth 
power of the myriad, constitutied numbers of the 4th order. Ij^ 
general, l>y taking a unit followed by the 2nth power o.f.the my. 
riad, he formed numbers of tha prder (n+ 1). fox example.; if \ye 
suppose n r= 8, Snzr 16, a unit succeeded by I6 times 4 noughts, 
or 04 noughts, will compose numbers of the ninth order, or (8 + 1), 
,the whole comprising o5 figures. Hence, to express 64 figures, 
Archin\edes required the 8th order of numbers. It is worthy of 
xernark^ ,tl:^at this indefinite method of notation appears to have 
l>een invented by hixp for a particular purpose, and to have been 
used only once-: viz. for expressing the number of grains of sand 
contained in a sphere, .the diatnetjer of wiiich was equal to the 
distance between the earth and the fixed stars. Archimedes also 
invented a method of expressing a geometrical series of which tbe 
.first term was unity and the common ratio 10 : this he effected , 
thus A, ' ' 1^ p, fS *•» '•» &c. 

I, 10, 100, 1000, K)000, 100600, &c. 

Apollonius, , according to the relation of Pappus, made some 
I convenient changes in this system of notation. Instead of tha 
orders or divisions consisting of 8 cyphers, he supposed them to 
be divided into periods of four, figures each. ^ The first period to 
^^ ri^t hand was ^at of units ; the second that of simple myr 



1^6 Mr. Bar low on the Transfurmctum ojf Numbers. 

riads, the third was that of double myriads, or those of the second 
order ; and so on. In general, the nth period of the number con- 
tained myriads of the degree (n—l). Thus the same characters 
occtirred in each period, but with a value always increasing, and 
proportional to the successive powers of the myriad. The same 
author likewise made some further improvements ; for an account 
of which we must refer tbe curious reader to the third volume of 
Wallis's work*. 

The nought was not entirely unemployed by the Greeks ; but 
H is only found in the works of Ptolemy ; where it is used to sup- 
ply the place of a number in the sexagesimal notation, where no 
value occurs^ TIjus, in the table of the declinations of the ecliptic^ 
0% ^y, i/^ signify D^ 24^ 16^^ and ^r^ (/, hi/^ denotes 6^, (/, 31^. 
Among the Greeks, however, the zero was always used singly, and 
liever combined with any other figure, as with us, to change its 

value- 
It only remains fot ua now to give a brief account of their me- 
Ihod of expressing fractions. For this purpose, a dash placed to the 
* right of a number, and towards the top, indicated that the nuipber 
was the denominator of a fraction, the numerator of which was 
unity. Thus /=| ; y=z l ; {^=1 ± ; ^u^zz ^. The fraction 
1 had a particular character ; (, or <, or {f^ or K, When the nu- 
merator was not a unit, the denominator was placed in the manner 

of our exponents. Thus, »«{• or 15^ denoted -jj ; apd gp wa* 

written {p The Greeks appear to have had no mode of ex- 

pressing the parts of a unit in 9 similar manner to our decimal 
fractions. For farther information on this curious subject we 
must refer to Delambre's essay, and the works of WalUs, above 
referred to. 

. We shall now conclude this article with a few words respecting 
Mr. Barlow's paper, This we consider as both ingenious and 
novel ; but neither entirely free from errors nor pregnant with 
utility. The former of these we shall endeavour to correct, as 
well as to state in what we diflfer from the author relative to tbe 
latter. In the first algebraical formula, the 9 appears to have 
been an addition of the printer. In the first example ofduodeci* 
nials, we think Mr. B.-wiil agiee with us, th^it the third productr 
should be ^49 instead of y^9 ; that tbe suQi of tbe products should 
be 1 1 . 7542, and not \% 8542 ; and consequently that the result 
is 13 feet, 7^ 5^^ 4^^^ ^^^^f, instead of 13 feet, «^ 5^% 4f'\ ^^^'^^ 
as given' by him. This mistake has evidently originated with the 
author. NVe do not agree with . Mr. Barlow that his method of 
performing the multiplication of duodecimals \%akmyi preferable 
to the commoii rule : for when the number ef feet does not exceed 
1^, and not parts less than inches enter into eithtr faetm*, the usual 
metbed evidently has the advantage. la -ether-^asee; and especi^ 



Oa the infiuaicc of Lighi on lie propagciian <f Saund. }^t 

illy when a little custom may have rendered the use of th« two 
additional characters and method of transferring the numbers from 
the one scale to the other familiar, our opinion coincides with liis. 



hqitiries cimcernmg the influence ^ lAght 6n the Propagation W" 
Suund* By Mob£ST£ PXeolette.— 7o«r. de Physique^ «xj|; 
LXVIIL 

The subject which Mr. Parolette has chosen as the object of 
ibis inquiry, is the relation which subsists betw«ed the action of 
light and the vibrations of sonorous bodies ; and after some gene- 
ral remarks on the importance of iight as an agent in natural phe- 
nomena axkd its effects on other of our senses besides vision, be 
states the means which first suggested this inquiry, to have been 
the difference he observed in the sound of the wheels of carriages 
before, and After day-breaiu The noise of the wheels appeared to 
acquipe a more soaorous sharpness after the dissipation of tiarkik 
iiess, and seemed to announce the friction of two substances posses- 
sing a greater degree of elasticity than before ; and further obser^ 
vatioDS confirmed the opinion, that light exerted a considerable in- 
fluence on the propagation of sound: The action of the wind 
could not have much influence upon this propagation, even whea 
moving in the same direction, as its velocity is less, and it ope» 
rates only on large masses of the atmosphere. As the propaga.. 
tion of sound is affected by extremely small vibratii ns, Mr. Paro- 
lette thinks it probable that this takes place in particles of a very 
light elastic fluid of a peculiar nature, distinct from the gasses, 
of which, aiccording to our present knowledge, the atmosphere it 
supposed to consist,. He therefore endeavoured to contrive an in- 
strument fur obtaining an accurate measure of the propagation of 
tound, and determining whether his senses had been deceived. 
As it is known tliat the vibrations of elastic fluids are alway ana^ 
logous to those of the particles of the sounding body, and that if 
two strings, belonging to two instruments, be in unison, when the 
One is touched the other will vibrate and emit a perceptible sound, 
Mr. P. thought be could avail himself of these properties in the 
coostruction of his appai^atus and determiDing the object of his 
inquiry. 

In forming tlie apparatus for this purpose^ Mr. Parolette took 
two good violins, furnished with well chosen Naples strings, and 
]iad the pegs made with copper screws, that he might be able to 
regulate the tones with a greater degree of precision. He placed 
tbeee violins on a horisontal plank, which was ten feet long and 
^ight inches widei Having tuned thej»e,two instruments to the 
Paris diapason, he fi^^ed a bit of paper to the second string of not 
of tbem> for the purpose pi $ervin^ for a» index during tb4 course 

310. 23.— VOL. VI. t 



&S On the vffinence of Ugh t on the propagation of^ Sound, 

of Ills experiments. As it was necessary that the distance between 
the^e vio1in& should be suscrptible of vanation^ and also for 
this to be marked with great accuracy on the plank that consti- 
tuted the ba^e of this apparatus, one of them was fixed and the 
other moveable. 7'hat to which the paper was attached was the 
fixed one, and a line correspoodmg to this string was drawn on 
the plank. The other was fixed upon a small wooden frame, 
which was moveable on the plank by means of two grooves; and 
stras drawn backwards and forwards by the application ef a screw 
in the end of the plank upon which ihe instruments rested. The 
frame contained an opening parallel to the second string of the 
moveable violin, which admitted the change of place in the expe- 
riments to be marked on the plauk. The apparatus being thus 
constructed, the second string was pressed till it touched the third, 
and then let go instantaneously. This fingering was done at the 
same place, and in a uniform manner, and produced an oscillato>- 
ry motion, which wsts heard on the corresponding string of the 
other, viol in. The paper showed the vibration of the string at a 
distance, and the violins were separated from each other until the 
agitation of the paper ceased. This point was the limit of the 
vibration, and was marked on the support of the apparatus, and 
numbered 100. The distance between the two marks on the 
plank answering to the two strings, was then divided into 100 
equal parts, and each extreme division into tenths, that thefe 
might be thousandth parts in the scale. The first experiment 
was not only to furnish a standard of comparison for the iscale 
of the apparatus, but also for the difference in the propagation of 
sound, as determined in future experiments. This first experi. 
m'^nt was made on the 14th of May 1803, and accpmpanied witU 
the following meteorological observations ; vis. Fahrenheit's ther- 
mometer 51*8% barometer 30*28 English inches, and tb€rh^gro.r 
meter 39* '^^^ experiment was begun at 20 minutes past noon, 
and repeated several times, and the apparatus always indicated the 
same distance to a few thousandth parts. The whole extent of 
this scale was 7 feet, and this distance was the limit of the 
greatest propagation of sound under the influence of light in the 
apparatus, which the inventor denominates a phonometer. 

After this experiment, it occurred to the mind of Mr. P. that' 
the effects of other causes might be confounded with those of 
light, and that changes in the state of the atmosphere were most 
likely to inftuepce the results of these experiments. He therefore re- 
4>eated the experiment on three different days, and in very different 
states of the atmosphere, and the greatest differeiice of th^ results 
did not exceed three thousandth parts, which Mr. Parole tte thinks 
ought rather to be attributed to the imperfection of the instru^ 
ment than to the different state of the atmosphere. 

Mc P's next object wits to try his instrument in the dark, and 



On ike Influence <^^ Ught on the propagation of Sound. 59 

tjiis be ^id by tbe assistance of a watch lamp of a peculiar con- 
struction, whicb afforded ligbt enough for observing the motion 
of the paper, without lighting the room. Tbe following was the 
state of tbe different instruments ; viz* Thermometer 53*24^, ba- 
rometer 29*79> hygrometer 65, and phonometer 98*1 : the time 
of observation was eleven at night, and the sky covered with 
clouds. Several other comparative experiments were also made 
both in the day and the night, and the results were constantly 
favourable to, the influence of light. The mean term of the de. 
grees of propagation of sound without light waH found to be 0*98 ; 
and the mean difference of this propagation at noon and mid. 
night was two degrees of the scale, answering t<» about \6 lines ; 
when the experiments were made with the greatest caution in 
guarding against any inaceuracy. 

^ight has been considered to be more favourable than day to 
the propagation of sound ; but Mr. P. concludes that this arises 
merely from the absence of noise ; and thinks that the ear pos- 
sesses more aptitude for hearing by day than by night, on account 
of the stimulant action which light exerts on the nervous system ; 
but this will not explain the phenomenon of the paper, which 
depended upon the tremulous motion of the air in the room. He 
then asks, is atmospheric air more dense in li^ht than in dark- 
ness ? Is tliis greater density of the air, or of the elastic fluid 
which is subservient to the propagation of sound, the effect of 
aeriform substance preserved in this state througli the medium of 
light ? This hypothesis, he conceives, would confirm Dr. Priest- 
ley's opinion, that the propagation of sound in different gasses 
was in the ratio of their densities. But Mr. Perolle, whose ex-- 
fieriments are inserted in the 3d volume of the Menioirs of the 
Koyal Academy of Sciences ol Turin, has proved that the propa- 
gation of sound depends upon the patur^ as well as the density of 
th$ different gasses through which it passes. Of these oxygen is 
best adapted to its transmission, it is certain, that during the 
day, the atmosphere is more saturated with oxygen than in the. 
night ; but it remains to be proved that this excess' is sufficient 
to cause such a difference in the propagation of sound during the 
two periods. Rather, may not light be the true cause of this 
increased propagation ih oxygen and nitrous gasses ; as it is 
known that the former has a great capacity for light, and the > 
latter cannot be formed without its presence. As the velocity 
,of light is 900,000 times greater than that of sound, it does not 
appear unreasonable to attribute its effects on the vibrations 
which proceed from sonorous bodies to the mechanical action 
of its particles. Mr. Paroiette thinks that the more deeply nar 
tural phenomena are investigated, the more cleariy we shall per* 
ceive, that the powers by which the universe is moved reside in 
ih« imperceptible particle& of bodies ; and that Uie granil^ results 



So On the Qanera Lueicta. 

df nature eonstitute only ao assemblage of actious, that take* 
place* in its infinitely small parts. 

OA#cn»tfft"o«5.— Whether we consider the nature or effects of 
light, the number of phenomena which it exhibits, or the ad- 
vantages which mankind derive from them, there is no object 
more worthy the attention of the natural philosopher than this \ 
none which acts so considerable a part in the economy of nature^ 
The extreme divisibility of light, and the amazing rapidity of its 
propagation, render any enquiries respecting it both delicate and 
difficult ; and the smallest degree of success in researches of this 
kind strikes the mind as the presage of important discoveries. 
This communication, we understand, is to be regarded as an ac- 
count of the first of a series of enquiries which Mr. Parolette btts ' 
undertaken to pursue. In a note, he observes, ** My object is 
to ascertain the action of light in the various phenomena that 
take place in the elastic finids by which we are surrounded. 
This objject is connected with the mechanism of our sensations, 
en the one hand, while on the other, it embraces the results of 
those first combinations which escape our apprehensions. 

The apparatus with which these experiments were made seems 
lo have been well adapted to the purpose, and Mr. P. has at 
least opened the way to an interesting field of inquiry ; and his 
experiments are such as deserve to be repeated by other philoso- 
pher8« cither with a similar apparatus or some other which their 
ingenuity may devise as more proper for the pbrpose ; at the 
same time we must profess that we entertain some doubt of the 
validity of the inferences which he has drawn from them : it seems 
eanier to suppose that he may have discovered a minute vibration 
more readily in the day time than at night, than to attribute 
llie whole effect to the immediate operation of light in the trans- 
mission of sound. 



Mil 



1, On the Gamer ($ Lucida. B^. Mr. T. Sheldraks. fVitb 
a Remark b^ W^ N.^PhiL Jourri. No. 105. 

% On the Camera Lucida. By Mr. B. Bate.— PAt7. Joum. 

Nv. 107. 

3. On ik$ U$€ of ihe Cmmera Lucida at a subsiUutefor the 
Camerm Obmsura. B;gf Mr. T. Shxldraks.— P^'/» Journ. 
ifo. lU. 

1. Ik this paper, Mr« Sheldrake institotes a kind of iw^irj 
mpeptiUft tJ^e QomptreAiyQ meril? of tiie rtnera locida and 



On ihe Omerm Lueida. ei 

the camera obscura. The first of tbttc^ fa^ sc^rv^ represents 
objects with more brilliancy and distinctness, and either singly or 
in combination^ with perfect truth and correctness of perepective ; 
\nii it places before the eye only a certain portion of the objects 
to be imitated, and a certain portion of the paper on which the 
imitation is to be drawn. The camera obscura fixes upon the 
paper the whole p'icture at one view, so that the artist has only 
to pass his pencil over it to render it permanent; but, under 
some circumstances, tha objects are rather deficient in point of 
brilliancy, and. somewhat distorted from the truth of perpective. 
Mr. S. states, that he has found many inconveniences in using 
the camera lueida, for which he could not find a remedy ; and 
from the masterly drawings that have been made with the ca. 
mera obscura, and the facility of execution obtained by it, he 
thinks that it deserves the pieference. He concludes by observ* 
ing : 'Mt appears then, that a perfect instrument to be used as a 
(delineator is still a desideratum, and will be obtained when tlie 
separate advantages of the camera obscura and the camera 
lueida can be united in the same instrument, and not be dimi- 
nished by any of the inconveniences to which each of theo^ is at 
present subject. 

Mr. Nicholson thinks that it certainly was the intention of 
the inventor of the camera locida, '* that the tracing should be 
made upon that part of the paper where the picture and the 
point of the pencil can both be seen coincident, and ndt that 
a copy should be t£^en in the manner described by Mr. Sbel* 
drake/' This is to be effected by n>eans of the small stop which 
regulates the quantities of light that enter the pupil of the eye 
from both the paper and the prism ; and is easily obtained by a 
little practice. 

3. Mr. Bate conceives Mr. Sheldrake's statement to be too 
unfavoorable to the camera liicida. He thinks that it possesses 
some advantai^es not generally known ; and agrees with Mr^ N. 
relative to the coincidence of the picture and tlie pencil ; but 
thinks that the management of the eye in the use of this instru*^ 
ment has not been described with sufticienf minuteness. He then 
shows Mr. Sheldrake's method of using the camera lueida to be 
imperfect ; and describes his own, which has been attended with 
better success. Mr. B. thinks the young artist may obtain art 
essential benefit from a limited use of the camera lueida, by em- 
ploying it to fix the outlines of one or two objects situated near 
the middle of the view ; and that the accomplished, artist may 
likewise save much time in the delineation of extensive and com* 
plicated subjects, by using this instrument in determining as 
inaiiy points as he deem important. The combined advantages 
attending this instrunMnt, ** and al>ov^ all, the truth of the re- 
.^ctcd image« under every eircamstance, give th|r camera lueida 



6t Mr. On onjloating Bodies* 

a decided superiority over all other known contrivances for the 
same purpose." 

3. Mr, Sheldrake's object in this second communication, is to 
show that the camera lucida is not aa advantageous substitute for 
the camera obscura. He, therefore, illdstrates the use of this lat- 
ter instrument^ and then endeavours to bring the former one to the 
same test. He states that the portability of the camera lucida, 
which might be thought one of its chief advantages, is not so m 
reality ; for it requires to be used upon a table or stand equal in 
size to the camera obscura. The superior brilliancy of objects is 
of no advantage, as this must be destroyed before the pencil with 
which they are to be delineated can be seen. Jhe projection of 
near objects is frequently a great obstacle lo the use of the camera 
lucida, as '* it is indispensibly necessary that the light should fall 
upon the pencil and the paper, or the view and the pencil wilPbe 
seen so very imperfectly, that it will be almost impossible to make 
any kind of sketch, however imperfect, with it." Mr, S. concludes' 
his comparison with observing, that the camera lucida possesses 
no advantage which will induce an artist who uses the camera ob* 
scura, in the prattice of his profession, to abandon this latter la 
order to adopt the former. 

Obseroatiotts. — We noticed the specification of Dr. WoUaston s 
patent for the camera lucida, at page 90 of our 3d volume, and 
stated several reasons which induced us to give the preference to 
the camera obscura, as well as noticed the want of (perspicuity 
and precision in his description of the instrument and manner of 
using it. The defect in this last particular induced both Mr. Shel- 
'drake and us to conceive, that the object was to be seen upon one 
part of the paper, while the drawing was to be made upon another. 
This, however, seems to have been corrected by Mr. Nicholson 
and Mr. Bate ; yet we think that some practice will always be 
required before Dr. Wollaston's instrument can be employed with 
facility. 



Observations on loaded and unloaded Barges f Boats^ Beams^ or floats 
ing Bodies descending wih Sti earns or Currents, and vihy the 
heavier End will go foremost. JBy Geoege .OaR, JS«f. Fhil. 
Mag. No. 141. 

In this communication, Mr. Orr affirms that, when any body 
floats in a fluid, there are always two powers opposed to each 
other ; these are the specific gravity of the fluid, and that of the 
floating body ; and that in proportion to the difference of these 
will the bodies oppose each other. Another of Mr. O's propo- 
sitions is, that ** when water is perfectly at rest^ it has found its 



Mr, Orr onjlooting Bodies* 63 

level, or all its particles gravitate towards the centre of the earth 
in perpendicular and right lines." But on any change of state 
taking place, the particles of. the daid are put in motion, by the 
force of gravitation, and either endeavour to find their level again, 
or continue to move down an inclined plane ; the bodies sus. 
pended in this fluid partaking of the same motion. *' The velo- 
city of a stream, river, or current, and of course of bodies that 
float in them, will be greater or less, as the inclination^ of the 
plane on which they descend departs more or less from the line 
bounding the horizontal plane/' 

The reason that heavy bodies floating with the tide make a 
greater progress than the tide itself, is, that all the particles of 
the floating body act in one mass ; and the less degree of friction 
which takes place^ between a solid and a fluid, than between the 
particles of the fluid. After some remarks on the collision of 
heavier and lighter bodies, and the probable existence of an under 
current from a bay when the wind blows strongly into it, Mr. 
0. observes, '* All pressure on bodies floating with streams must, 
whether the pressure be perpendicular or oblique, increase their 
progress :— *if the pressure be perpendicular, it adds to the weight, 
and consequently to their power of overcoming resistance on the 
part of the fluid : if the pressure be oblique, and in -direction of 
the motion, it will, besides increasing the weight, give impulse/' 
The reason why this effect does not take place at sea, is supposed 
to arise from the opposite inclination of the planes which com- 
pose its surface. Bodies of different shapes, are supposed to 
make different degrees of progress ; and that those used at sea for 
finding the direction of a current, should be conical, with the sharp 
angles at the base rounded off. Mr. O. then enquires, '* lastly ; 
does a body floating down a stream or current, and which has a 
quicker progress than the stream or current, receive any addition 
to its motion from the motion of the fluid V This he thinks 
ought to be answered in the negative. 

\ 

Observaiwn8,''^Mr, Orr informs us, at the commencement of 
this article, that his ** object is an endeavour to attain the truth on 
so interesting a subject;'' and as our object perfectly coincides 
with his, we hope to be exempt froni any accusation of " peevish, 
ness and personality" when we express what, on the present oc- 
casion, appears to us to be " the truth/' We shall, therefore, 
begin our remarks on this paper by observing that it consists of a 
number of notions on the subject, already published by himself 
and others, and noticed at pages 132, 345, and 351 of our fifth 
volume, huddled together with admirable confusion ; and expres* 
sed in language so inaccurate and indefinite, as to be wholly unfit 
for ** the discussion of philosophical subjects.^ This assertion is 
supported by several examples in our quotations in the preceding 



64 If r» brr tmJldaiiMg Bodies. 

abridgement, and others are not wanting to corroborate the ge^ 
neral truth ; such as *^ floating on the surface more or less deep/^ 
Deep on a surface f *^ A cylinder with all its transverse diameters 
equal, the other of a conical fo^m, with its transverse diameters 
or lines all unequal/' Can Mr. O. conceive a cylinder or a cone, 
the diameters of which are not transverse, or do not possess these 
properties ? 

We shall now take a view of this paper independent of its inac. 
curacy of expression. A great part of it is employed in attempts 
ing to prove, what bad either been already demonstrated, or needed 
no proof ; and some of Mr. Orr's other positions appear to be ei^ 
ther defective or false. With respect to what he asserts to be the 
cause of the accelerated motion of loaded barges, we must refer 
to our former remarks on the subject, at page 134 of the dth 
volume of this work. The assertion that '* all pressure on bodies 
floating with streams must, whether the pressure be perpendi* 
cular or oblique, increase their progress,'' is neither ruw nur true. 
The former of these is easily proved by a reference to Captain 
' Barney's paper, noticed in our fifth volume, acd the latter by re^ 
fleeting that (according to Mr. O's expression) the pressure may 
he exerted in a direction oppasiit to that of the motion of the 
floating body, and consequently will rather retard thata increase ita 
progress. Mr. O. is not more correct in his supposed analogy be- 
tween a loaded ship at sea, and a loaded barge floating with the 
current : besides, independent 4)f the failure of this analogy, a 
little reflection ought to convince Mr. O. that the cause to which 
he has attributed the difference in the rates oi sailing between a 
heavy and a light ship, has very little if any influence on the Hub^ 
Ject. Towards the conclusion oi th«8e observations «e meet with 
the following sentence : ** Supposing A barge loaded at one end^ 
and empty at the other, and without a helm, if it floated in a fair 
and regular stream, without Currents, it would certainly proceed 
with its heavy end foremost, for the same reasons that a conical 
piece of wood, or even a cylindrical one loaded at one erid^ would 
go with their heavy end foi^emost in a fluid, tliough originally 
placed in a contrary direction: it would be the same with the 
cone and cylinder, if placed a«;ross a dry inclined plane ; that end 
containing the greatest quantity of matter, from its power of over- 
coming resistance, would always have a tendency to be fort^aost/' 
By *^ a fair and regular stream" we understand Mr. O. to mean 
one of which all the particles move in straight and parallel lines ; 
if so, and a .cylinder with one of its ends somewhat heavier thau 
the other, were placed with its axis exactly in the vertical plane 
of its motion, with the lighter end first, we must ask Mr. 0« 
what force, according to the mechanical laws of nature, could m«> 
duce a reverse of position ? Nor does the analogy which is here^ 
supposed between the motion of a conical body floating dowa st 



Mr. Orr ek jtoatwg Bodies. 6^ 

Ureatnand rollit\g down " a dr^ inclined plane," dt all subsist ; any 
inore than the power of overcoming resistance inherent in the 
greater enJ of the body, arises solelt/ from its containing a greater 
quantity of matter, as Mr. Orr's language indicates. For, let us 
Suppose a conical frustum, the density of which varies in the in- 
verse ration of the magnitude of two indefinitely thin laminoe per* 
jiendicular to its axis ; then it is evident that each of these la- 
iiiiujB will consist of the same quantity of matter, and that if this 
frustum were placed " across," and peitnitted to descend dowr> an 
inclined plane, the greater end \v<)uld experience the greater de-* 
gree of resistance from the medium in which it moved. Now, 
tiircording to the hypothesis of JNlr. O. a^ each end contained an 
tqual quantity of matter, ihatwliich met with the least resistance 
ought to proceed first ; but will this be the case? certainly not. 
The fact is, that while the body rollis, on account of the friction 
of the plane, thfe laJ'ger end will be rimde to descend faster than 
the smaller, and the body will theietore ultimately slide with this 
Hid forehibsrt ; but in the case of the floating bodv, there is no 
rotation, and thuS caus^ of a change of direction must vanish. 

After the perusal of these remarks, we think our readers will 
agree with us, that Mr. Orr does not possess either a 'very accu- 
rate, or a very extensive acquaintance with the subject which he 
has chosen for the exercise of his ingenuity. He seems to be 
more desirous of diflusing around him what he thinks he has acs 
quired, than anxious to grasp ^hat yet lies before him j or irt 
olher words, much fonder of utififig ihati of reading ; tut we cah 
assure him that the former is an ihdispcinsible requisite towards' 
performing the latter with efl'ect ; and we would, therefore, aft 
friends, advise him to niake himself well acquainted with the imi- 
pulsions of wind and water^ and the invariable laws of mechanical 
nature, before he favour the publick vvith atiother communication 
on riiis abStrhse subject. We shall conclude these remarks by. 
observing that Mr. O. in this paper, intimates his. intention of 
attempting to dcmonsttate that it is principally owing to a differ- 
etice of sliapfe that one ship saHs better than another That bo- 
dies containing equal guahlities of matter, but of different shapes, 
receive d.i^'erent degrees of resistance, when moving with equal 
velocities through the same medium, has been b(!th tt70 long and 
too Wf'll khown to herd any demonstration, notwithstanding the 
partial exceptions made by Mi*' llomme : and this we are induced 
to mention with a view of saving Mt. O. either the labour of his 
task, or the moitification arising from its inutility when performed. 
M'e iiiay observe, however, that if he can, in a simple and perspi* 
hmus manner, demonstrate the ffvst form of a ship for bailing, he 
will perform an acceptable service to the public, ahd be justly en* 
titled to all that we, as guardians of science^ have to bestow — our 
approbation and thanks. 

2tOi 23, — TOL. VI. K 



( 66 ) 



REVIEW OF SPECIFICATIONS OF PATENTS. 

I 

PUBLISHED ly THE REPERTORY OF ARTS, MANUFACTURES, &C. 

During the Months of January j February ^ and March^ 1810. 



Jl/r. John Leigh Bradbury* Patent for a Method of spinning 
Cotton f FlaXj and IVooL Dated December 1 SO/. — Repertory of 
ArtSy No. 92. Second Series, 

In the method here described the fly with its arms pointing 
tsp wards,. turns upon a vertical spindle« the bottom of which rests 
upon and turns in a step fixed to the upper side of a rail which 
supports it. This spindle passes through a rail above, which sup- 
ports the fly resting on a masher. The upper part of the spindle 
i3 smaller than the rest, and carries a bobbin, which is supported 
by a shoulder on the spindle, at the lower termination of the 
jimall part. A wharve or pulley is ilxed on the spindle, and aoo- 
tber on the socket of the fly, each of which is turned by a band 
from a separate drum ; the motion of the Hy twists the thread as 
delivered from the rollers of tke machine,, and by means of the 
thread it also turns the bubbiu. The draught or winding up of the 
thread arises from the friction of tlui bobbin against the spindle ; 
and is regulated by the rotary motion of the spindle, as imparted 
by the drum fixed opposite its pulley ; and it may either revolve 
the same way with the fly, or in a contrary direction, or may 
remain stationary, as the quality of ^e thread requires. The pa- 
tentee prefers the vertical positionyand observes ; " The principle 
ofthis improvement, as distinct from the old mode, consists in in- 
verting the fly, and giving it a separate motion from the spindle. 
The improvement arises chiefly frora^ the ibllowing particulars ; 
first, as the fly is the chief agent in twistii«g the thread, it is the 
only part kept in rapid motion ;. consequently there is u great 
saving of power, since, in the old machine, the spindb and fly 
are turned together at the same speed. Secondly, the h^bin, fly, 
and spindle, having their distinct and separate motions, the 
draught or inclination of the thread can be regulated to the ut- 
most exactness, and, when regulated, will remain invariably the 
same at whatever speed the machine shall turn; whereas in the 
old mode, a variation of speed produces a variation of draught, 
thereby breaking the thread and causing much waste. Thirdly,. 
on account of the inverted position of the. fly, the bobbin can be 
taken oflf, and put on with expedition ; whilst, in the old plan it 
was necessary to stop the spindle, and unscrew the fly from the 
topy or to take out the spind^^. By these ini{)rovenients the quan.' 



J 



Mr, FohcVs Patent for cert am I'mprovcmtnti on Pens* 67 

tity'of yam produced by eich spindle is nicarly double to that of 
the old plan, witli the same power, and of any degree of fineness 
required/' 

Obiercafions, — In November, 1805, the Earl of Dondonald ob- 
tained a patent for the same purpose as this of Mr. Bradbury : 
it was described at p^^ge .97. of our third volume. The traverse 
motion of the thread on tlie bobbiM in the present instance is ob* 
tained by a vertical motion of the fly, as in one of the cases of 
Lord DondonaldV invention; but the circumstance of giving to 
each of the parts a distinct and separate motion, appears to be 
neW| and is doubtless a very material improvement, as by it the 
draught may be regelated according to the rate of spinning, and 
much lewer threads broken than in Ihe common way. The rc» 
^version of the tly also is calculated to admit the bobbins to be 
changed with nmch greater facility than before ; and if the pa- 
tentee's concluding statement rel/tive to the quantity of yarn 
produced by each spindle be correct, this is certainly one of the 
most essential improvements that has been introduced into the 
machinery in use for spinning cotton since the inventions of Ark*- 
Wright, unless the one denominated the mule must be excepted; 



s=r 



^ 



Mr. Fredeuick BAaLiioi.oMEw Folscii'* Patent for several 
Imprwct mcnts on art am Machinvs^ Instruments and Pens y calcu^ 
lated to promote Facililj/ in JVriting, Dated May I8O9— iJe^^er- 
t or If of Arts y No, S'2- StCund Scries. 

The patentee states these improvements to be ^hreefold.-«- 
" First, in having a valve acting with a spiral spring, or screw, 
to fix it on the top of the pen, to supply it occasionally with air, 
to force the ink into the socket of the pen. Secondly ; in having 
a small pipe at the bottom of the tube to convey the ink into tb% 
socket of the pen, through which it is forced by the operation of 
the valve at the top of the tube. Thirdly ; in having a plate on 
the front of the socket of the pen, to contain a supply of ink for 
the nib, and to pi event the ink flowing t»)o freely into the rub." 

This pen may be made of any sort of nietal, and consists of 
three parts, viz. a lop, denominated a box; the middle part', 
called the tube, and the lower extremity,- styled. the socket: it is 
thus made in three divisions for the convenience of cleaning when 
necessary, supplying it with ink, and prefixing different nibs to 
the same socket. The top part, or box, has a bottom sc^dered into 
it, with a h<\le through it to admit the air to pass into the upper 
part of the tube. This box ccn tains a -spiral spring, and a small 
rod which passes through the hole in its bottom, and has a valve / 
fixed to it at the inside of the tube. One end of the spring is 



festemd to the bottoro of the box, the other to a kncib wbich 
screws on to the top of the small rod : tbe ipring, therefore, 
presses upwards against the nob, and keeps the valve close lu the 
bottom of the box, to prevent the ink Irom entering it from the 
|uhe. The tube has a small pipe soldered inlo its bottoni to ad- 
roit the iuk to flpw into the socket or lower part, to which it is 
united by means of a socket joint. 'J he tochet is made hoUoWf 
pnd has a small hole'in front, for iulm tting tht^ air and regulating 
.the quantity of ink that it will Ijear. The lower part is made ii> 
the shape of a conmmn pen with a slit nib ; and has a plate sol- 
dered in its tropt- The lo\\^r end of this plate is iitle4- nearly 
close to the^^ hollow of tlie nib, but IcU loose and iu a {-lasting dit 
rectiou towards the point, and below the top of tlie sht up th« 
nib, so that in writing thp nib binding it lets the ink pass freely, 
but not too copiously, to the point of the nib." In scHiie of the 
sockets the lower part is Qiade angular, and the nib has no slit^ 
but a small notch or groove at the end. The tubf also \\\Hy be 
used without a box and spiral spring, by making tiie top pr knob 
to screw on the tube, and having a hole through it within the^ 
screw part of it, which will admit the air by mfbcrewing the top 
a littlft, and answer the purpose ot tho bo:^ and screw. 

»■' I ■ ■ II I ■ I III* 

• . 06»«Tffft'a«#.— Messrs. Folsrh and Howard took out a patent 
for a similar object, about two months prior to the date of this, 
and which we have noticed at page 3S1 of our preceding volume, 
' These imprweniepts we think are justly entitled to the appella- 
tion, and are well calculated to furnish a constant and regular sup- 
ply of ink with very little trouble. Their object is to unite the 
pen and inkstand, or bottle, in one instrument, and thus to aiford 
on many occasions a source of convenience which could nototliei"- 
wise be easily ol^tained. 'i'his object appears to have been inge* 
niou^ly accomplished ; and the only objection to which it seems 
to be exposed, is U)e drying ot the ink when long kf pt in the tube 
'91- socket of thf pen. 



'IT"!^" " '" ■ ' ' " nm^v^^f'^m 



Jfr. Edward Manley'a- PaUntfor aVlough. Dated May I8O9* 
— Repertory of Arts, No, Q3. Second i^Vrief. 

Mr. Manley* denominates this the Expedition Fl&ngh, and states 
that it *^ has this advantage over every other implenjent, that the 
same horse-power hat more than double the eftect in draught, and 
that the work it makes is greatly superior to that of every other 
plough." It is 'Worked by a beam in the common manner, and 
has three different sets of feet, which may be exchanged one for 
another as ciccumstances render it necessary. The number ifi 
paph of these sets vuries according to the extent of the beam,- and 



Mr* Huiton'^ PaitHtfor a^Methoti ofmtdcing Sickles^ Sfc. 6g 

the work to be performed. " The first set, when set shallow in the 
ground, will eitbpr scarify or spine; when set deep, they will 
draw themselves into the giound,. working it up and pulverizing 
it at a great depth. I'he second are used for the purpose of work- ' 
ing the ground finer. The third are used for turning the ground 
.over in single or douhle ridges. The beam or wooden frame in 
which the feet aie fixed, represents that of the common plough, 
' >vith the addiiioR of two arms or side beams to take the side feet, 
and is worked by handles, and set hy a wheel, A foot of the first 
set represents a coitlter, with a sharp pomt, having wings fixed 
behind. A foot of the second set exactly resembles that of the 
first, but is of a smaller size. A foot of tlie third set differs from 
tbe others only,' in that it^has a single or double broad plate &xed 
behind the couUcr." 



Ohservations. — Mr. Manley claims a very great superiority for 
his invention ; as far, however, as we can jud^e from its me- 
chanism, from the plate accompanying the specification, we think 
that the public will find it necessary to make a deduction from 
his statement ; and this deduction wjll perhaps not be a very 
small one when the land is stiff. 



■wwp* y^—^— ■»■— — ^ I'll' " I' *»—*« 



■ ■l II n m 



ilfr- William WuTTO-s.^i Batait for a Method of making Sickles 
. and Reaping-hooka, Dated July ISO^. '^^Repertory of ArtSy 
No, 93. Snutid Series, 

Ik tbe execution of this' method, Mr. Hutton directs that a 
piece of steel be hanmji'red or rolled into a suitable thickness, and 
made into the projjcr form for the blade of the sickle or hook* 
This blade is then to be toothed, and tempered ' according to the 
quality of the steel ; after which it is to be set and ground as 
usual. When the back has been made and fitted to the blade, it 
is to be fixed to it by means of either rivets or screws ; or the 
back may be made double, and the blade driven in between its 
liearly closed edges, and then screwed or riveted in order to fasten 
it more effectually. 

Obscrcaiums, — What advantages this patentee proposes to de- 
rive from his in\'ention, we are at a lo;ss to discover : one disad- 
vantage, however^ is obvious ; viz. the additional labour in the 
construction of sickles according to this mode. The blades may 
perhaj)s be made rather lighter, by Mr. H.'s method than in the 
common way ; but it will be at the expeiwe of strength : tbe 
weight being the siime in both cases. We apprehend that IMr. 
H.'s object is, by making tbe blades only of steel, toetlect a saving 
in the quaptity "of that metal \ but would not this have been 



TO Mr. Barton's Patent for a Lamp of a nca Const motion. 

equally effected by welding the iron and the steel together, of 
which the sickle was to be composed I 



Mr. John BARToy'* Patent for a Lamp of a new Constrvction. 
Dated November iSQ9,~^Repertorif of Arts^ No, 93. Second 
' Seiiet. 

Mh. Barton's method of raising the constant and necessary 
supply of oil, for the purpose of ieeding the wtck of the lamp, is 
by applying the hydrostatic pressure of a fluid of greater specific 
gravity than the combustible substance. 'I'he heavier Auid is 
contained in an exterior reservoir, in which the lamp with its 
contents and appendages is made to float. A communicatio« 
takes place between the two Euids through an aperture at the bot- 
tom of the lamp, and is permitted to flow into it as much as the 
counteracting pressure of the combustible fluid it contains wiU 
allow. By thus making the point at which the wick is placed 
moveable^ by the continual subsidence of the lamp in the exte- 
rior reservoir, as the oil is gradually consumed, common water 
possesses sufficient specific gravity for the heavier body : and the 
patentee conceives that by this and other improvements in the 
construction, he has ** accomplished the end proposed with greater 
advantage or convenience than the same has been hitherto done." 
He then illustrates this prmciple by an example and flgure, and 
afterwards describes one of t^ie lamps which he has e&iistrueted. 
upon iU 

The lawer part of the lamp consists of a cylindrical vessel of > 
thin brass or copper, having its bottom prefixed eith^er by a screw- 
joint, or in the manner of a snuff-box lid, for the convenience of 
cleaning the interior of the vessel. Through the bottom of this 
vessel, there is an aperture of about onc-teruh of an inch in dia- 
meter ; and from the top of it, the tube which contains and feeds 
the burners at its upper extremity issues. Above the vessel is ' 
fixed an air-tight vessel or float, nearly of suflicieut buoyancy to 
support the lamp and its appendages in the heavier fl«id in which 
it floats. * Another float is also fixed near the top of the tube; 
and these together are capable of causing the whole to float in the 
water^ or oth^r fluid employed to effect the hydrostatic pressure. 
The exterior part of the lamp coi>tarns this fluitl^ by wiich a coc^^ 
stant supply of oil is, famished to the bnrr;ers, aud in which the 
lamp floats. The bottom part of this exterior vessel which con.^ 
tains the vessel and oil, represeuts a pedestal, and the up^er part 
a vase ; this cast is to be made of such a size that it may con- 
tain nearly the same quantity of fluid, iudq)endent of the space 
occupied by the float, and the tube passing through it, as the 
vessel into which the combustible fluid is pat. It is al?a remarked. 



Mr. Barton's Fattntfor a Lamp of a new CohsitruGtion* 71 

that the lamp should be so constructed that the height of tbe 
^.'oluain of oil, should be to that of the water by which it is sup^ 
ported, in the inverse ratio of the specific gravities of iht two 
fluids. The tube which contains the oil is made to taper uf •« 
wards : and about one half of iis diameter below its upper extre- 
mity, there is attached a small plate or ledge concave upwards^ 
Hiid projected on each side of the tube, about one half of its dia- 
meter. The intention of this concave plate is to receH't ^the 
small quantity of oil which generally exudes from tbe wick of a 
lamp that is well supplied. Another similar plate, but of larger 
diameter, is fixed a little below this, and the tube is perforated 
with a row of small holes just above this last, to admit the oil 
which it may receive to be brought again into contact with the 
wick, and to permit the external air to paiss through tJbese aper- 
tures for the purpfose of increasing the combustion. 

Observations. -^^V^'iitfex^t and ingenious contrivances have been 
adopted by patentees to answer the end of furnishing a constant 
supply of oil to tl>e wick, without having the light intercepted by 
the vessel that contains the combustible fluid. For three of these 
methods, see our ^nd and 3d voliiiaies, pages Z7 and Sd- llie 
chief objection to these was tbe subsidence of the oil, occasioned 
by the difference between tbe upper and lower surfaces of tbe 
dense fluid diminishing as the oil >vas consumed by burning $ and 
this objection appears to be in a great measure obviated by m«k* 
ing the lamp with its contents float in the beavier ^uid« instead o^ 
being fixed at a certain point above it. 



Mr. John Duff's Patnitfor Snuffers of a new and impnircd Con- 
, itruction. Dated December \^0\)^^ JEiepeHory of' jirts. No* 
93, Second Series, 

In these snutrers,.a scraper turns on two'pivcHs, and » pressed 
rapidly hack by a spring acting against it. This, force operates 
against a prominent peg inserted in a valve as tlic door of the souih- 
fers closes^ which raises the valve and permits tbe snuff tb >pttSft 
into the receiver. This 'valve shuts again by >means of vts 4>w» 
weight ; and the scraper being of the same size as the valve, it 
acts as a second door to Ihe ^-eceiver, iintil it fs drawn back %j 
tbe opening of the snuffers, when the valve resumes its former place. 
One end of a piece of iron is fixed to the scraper, and the other, by 
means of an oval hole^ is held by a peg fixed in one of tbe sbanJK 
of the^ snuffers ; and on account of the shape ** of its aperture, 
draws forward the scraper at the opening of the snuffers* aod 
pushes it backwards as the snuffers close.'' Tbe receiver is emp* 
tied by a door at the end, which is opened by pressing the point nf 



yii Mr. EarrojCs Patent for improttment 8 in tVindoK B finds > 

^ the snuffers upwards or downwards. This djor is fastened by a 
spring on the inside. Two semioval cuts with sharp edges are 
made in the point of the snuffers, for the more effectually removing 
.Bpliuters or thieves from the wick uf candles. 



Mr. Jamzs Bah Ron's Patent for Iwprovanents in the Apparatus 
. vsfdfor Rollers far Wvidkrw-Blinds, Maps, and other similar 0/5- 

jects. Dated December I8O9. Repertory/ nfArts. No. 94. Second 

Series* 

In this improved method, a bracket is fixed to each end of the , 
lath, and the roller suspended by two pivots, either cylindrical or 
conical ; those of the latter kind the patentee prefers, as produ- 
cing less friction. One of these brackets is a spring fastened to 
the top of the laih, for the purpose of retaining the blind at any 
part of the window where it is required. This Spring is regulated 
or niade to act with a greater or less degree of force by a wedge 
inserted between it and the top of the lath, and movecl by means 
of a screw. This spring crtuses the pulley at the extremity ot' the 
roller 16 press agi^inst a metal plate fixed to the underside of the 
latb, and prevents the weight of the blind from running it down. 

The blind is rolled up by pulling a string which winds round a 
small spindle between two circular plates, m the usual way. 

When this string is drawn down, the pressure of the pulley is 
removed, dnd the blind rolls up freely to any required height ; 
but when the force is removed from the string, the spring again 
|>resses the pulley against the plate, and stops all further motion. 
One of the brackets may be made 10 slide outwards, to admit the 
pivot to be withdrawn, and the roller to be taken down for the 
purpose of cleaning or preserving the blinds. In this case the 
bracket is made to slide in between the lath and a metal plate 
attached to it ; and is retained to tfie pla£e by a staple at its outer 
^nd, while the other end has a bracket and a button which slides 
through a slit in the plate, and keeps ^ that end steady. For ad- 
justing the pivots with greater nicety, one of them maybe made 
to screw through the 'brackets, by which means the inaccuracy of 
the workman who mounts the roller can be corrected if necessary^ 

Obseroathns.'^We see fto material objection against the im- 
provements which Mr. Barron has made on this subject: they are 
simple, and if execulcd with care, are capable of answering the pur^ 
IKwe for which they were intended, very well. 



73 



Mn George Pocock's Patent for hit Indention of Geographical 
Slates for the Crnistructhn of Maps. Dated June 1808. Rvpert(/ry 
ofArtHy Ao, 9**} Second Series. 

Tills mvention consists in drawing liiieli of latitude andlongi- . 
tude, or other lines qn slates, to serve as guides to learners .of ' 
geograpliy in sketching the ditfcrent parts of the earth's suiface. 
The method of describing these lines on the slates which the 
patentee has adopted, is that of drawing the longitudinal lines oi 
the globe upon a thin plate of metal, and cutting out the alternate 
spaces. This plate will thc-n serte as a ruler by which thelon»» 
gitudinal lines nmy he traced upon the slate, by a sharp points 
tool, or other proper iostrument. The lines of latitude mftj be' 
described in the same manner by another siiniliar plate. 

The specification is accompanied with a drawing, representing 
the lines which are proper to be indented on a slate for preparing 
a map of the eastern and western hemispheres ; and slates for maps - 
of any particular parts of the world are to be prepared with »p* 
propnate lines^ according to the kind of map required. 

Observ at ions. -^The political and commercial relation which 
subsists between thiscountry and almost all the other parts of 
the globe renders geography a necessary and iudispensiblc part of 
a liberal education. Many experienced teachers of this science 
conceive one of the best methods of impressing the outlines of 
diflercnt countries, as well as the local circumstances of particular 
places on the mind of the youthful student, is to cause hmi to de. 
lineate them in their relative situations. 

For this purpose, outline maps .have been adopted by some, and 
those with the different lines only by others. The idea of trans- 
ferring these to slates was very simple and easy, and is well calcu- 
lated to facilitate the attainn)ent of the desired object, both as it 
will eftect a considerable saving in the expense, and as it admits of 
the wouk being d<efaced and renewed at pleasure, until the requisite 
degree of correctness be accomplished. 



J/r. Joiix 3 O'S t^*s' Patent for Improve/^H'/its in the manufacturinfr of 
S kelps for Fire Arms, Dated November I8O9. Repertortf of Arts ^ 
No, 94 Second Series, 

TuK patentee states that the principle of his invention consists 
in nmkiug plates of iron in a tapetlike form, and of sufHcient size to 
be c ut into several skelps : so that the grain or fibres of the iron 
iQay be drawn transversly in each, instead of longitudinally, as in 
4he present mode. To effect this purpose, he directs that a piece of 

xo. 23r— A'OL. VI. X . ' 



74 Mr. Jones*s Patent for manufacturing S kelps for Fire J rmu 

Von of a wedge like form, proportionate to the length and numbef 
of the skelps intended to be manufactured from it, be bleated to the 
usual' degree, and then rolled by means of the common apparHtus 
used in that operation, so that one edge of the plate may be thicker 
than the other ; their dltl'crence depending upon the kind of skelps 
wanted. This thick edge and taper-like form, he thinks, will be 
best produced by rcducmg the circumference of one and of one or 

* both the rollers us^d in the operation ; or nearly the same effect 
may be produced by a pair of cylindrical rollers, by giving one 
end of the upper roller more play than the other. The plate is 
then to be divided, from the thick edge to the thip, on the contrary 
way, into pieces proper for making the skelps : but in order to 
prevent waste in cutting, the pieces may be cut about the width 
of the muzzle of the skelp ; hence the' plate must be formed ra- 
ther thicker on the thick side, to admit of being widened towards 
that end by means of a tilt Ijammer, or any other method. The 
skelps mayalso be made in different lengths, and welded together 
either in the barrel or skelp form. Barrels manufactured fronn 
skelps of this^ kind are said to be more free from grays or flaws 
than those made in the usual manner ; and this is attributed to a 
greater degree^f pressure while the iron is very hot, which causes 
the pure particles .of the metal to cohere more closely together, 
than can 'be ejected by the strokes of the tilt-hammer under a 
less degree of heat. The grain or fibres of the metal also *^ being 
by this process laid round, parallel to the edge of the breech, 
they partake, in some degree, of the nature of what are termed 
twisted barrels^ gain a considerable addition of strength, and con- 
sequently stand proof with less ri&k of bursting." 



Odservations.^^Severdl patents have been obtained within a 
few years, for manufacturing the bairels of firearms, an may be 
seen by a reference to the different volumes of this work. One of 
these was granted to this patentee in I8O6, for an ingenious method 
of making^ twisted barrels; and upoA which this set forth in th« 
present specification appears to be an improvement, by bringing 
the fibres of the metal into an entire transverse, instead of a spiral 
direction. By this mode of manufacture the gun barrel may be 
regarded as composed of an indefinite number of endless rings of 
very fine wire, connected together into one mass ; and each acted 
upon by the force of the powder at the moment of explosion, in 
the direction of its length ; and every one who is conversant v^ith 
the nature and properties of iron, will readily conceive that this 
mass is capable of sustaining a much greater force, in this way, 
than .when it-tends to separate the fibres of the metal longitudinally. 
Wle ane;.thersforey inclined to think well of this method of manu- 
fi^ptiice,. and conceive that if it were generally acted upon, and 
carefully executed, it is suscfeptible of coi^siderable utility. 



( 75 ) 



Mr, David jMeade Randolph* Patent for certain Improrements 
in the Constructkm of IVhed Carriages vf every Dcscriptiop, 
Dated November I8O9. — Repertory of .Arts y No, 94. Second 
Scries, 

This specification is chiefly occupied by descriptions, of tl^e 
figures by which it >is accompanied, and as it is of coosideraiblQ 
length, and the figures are ninuerous, it would much cxcw^^ the 
limits of this work to give a n^inute description of all the parts; 
we can, therefore, only insert a few of its general principles, 4iad 
refer to the Repertory of Arts for further particulars. 

In a four wheel carnage intended for a mail or. stage coacb^ 
Mr. R. describes a contrivance which serves for a front seat aod 
step alternately. In tl\is coach tiie window also slides back Uorv" 
zontall}, and is furnished with bolts at the bottom, to prevent tue 
door from opening, when both are shut. A hook or joint isiixed 
in the vertical jilane which bisects the fore axletrce, for attacliii>g 
a pair of swingle^trees, by which the hind horses draw. At tnc 
. back of the coach, and at the same distance above the plane of 
the axletrees, whjch makes an angle of three degrees with the 
horizontal plane, as the hook of the seat of the outside passenger 
is placed ; and the inside seats are adjusted to the same inclina;- 
tion. The back part of the body of ihe carriage projects over » 
the heads of the outside passengers, and a curtain of piled silk or 
other proper material descends from the upper, part of the projecr 
tion to defend them from the weather. The fore part of th^ dri» 
^ver*s seat is perpendicularly over the front axletree, " which j 
from the wedge form of ihe platform and body, when the scat 
shall contain two or more, the load is' to be adjusted so, as nearlji 
as may be, to impose upon the hind axletree two-thirds of the 
load in all cases.'^ A check spring is also added to aid the others^ 
and'to limit the repulsive effect of all sudden shocks. When the 
carriage is intended to contain only one seat witjsin, like a post- 
chaise, the bind wheels are made lower in consec^uence of the pole 
being shorter, in order to preserve the three degrecg.of inclination 
as before. The shape adopted for t,hi$ carriage is tha,t of an acorn. 
** The door opens 19 front and directly behind the driver's seat, who 
conveniently opens and shuts the sapie.^ The steps are fixed on 
each side of the door« The construction of the platform and car- 
riage part of these machines, are next explained and illustrated by 
figures. *' Common waggons, with or without springs, to be made 
vitb three perches, and double bodied and heavier carnages, or 
carnages for conveying heaviest loads also, or with only one and 
^ings ; in all cases, rolling different tracts and preserving tlie 
wedge form ; and as far as may be, two-thirds of the several loads 



76 3Ii\ Randolph's Patent for th CosstruCtum ^ffVktd Cwrriegea. 

upon the hind axletree. All such waggons, coaches, or other 
four wheel carriages being dra\»n in like nmnner ; to wit ; a tri* 
angular tractor jointed at each end of the bolster, rising to a line 
with the horse's breast, or a little below it, and swingletrees as 
aforesaid, precisely perpendicularly «>ver the embreu^e of the pole 
by the futchels, thereby providing draft in unison with the lift of 
the front horses by a pole, or a unison of a lift and draft, more 
particularly necessary wLen drawn by a pair of horses only, or 
even by a single horse, which is to be done by the use of a pair of 
shafts instead of a pule/' 

Mr. R. then describes the construction of a particular and novel 
kind of waggons ^nd carts. The carriage part of ihtese, however^ 
does not differ from those already described, but the bodies rest 
and traverse longitudinally upon segments of circles, the radii of 
which are eleven feet each. These segments are supported 
by springs, or are bolted to the axletrees ; and one divided into 
three spaces, into which friction rollers are introduced. To the 
front of these carts or waggons, a vertical segment is tLccd for the 
purpose of attaching a pair of shafts to, which are stayed at the 
point of traction by a strong spring. " for the construction of 
frames and iron rail-way waggons, the front wheels of the front 
carriage roust be six inches diameter, the hind ones adjusted ac- 
cording to the length of the body, so as to elevate the centre, and 
form ^ line of inclination of three degrees, descending from the 
hindmost wheel of the whole series through theii axles, and those 
of the front ones aforesaid." It is also stated that in the cop-- 
struction of such trains or rail-way waggons, the diameter of 
each axletree is * not to be less than pne-eighth of that of the 
wheel ; the bearing of the axletrees in the boxes of the wheels, 
length of naves in the clear, and the bearing of the wheels ou the 
raiUway or road, c^re e^ch to be equal tp, the diameter of theaxle^ 

. As an improvement in the construction of all carriage wheels, 
the patentee observes that all sho^]d have £\n unequal number of 
spokes. A method of constructing wheels with cast iron naves, 
and a double set of felloes, the inner being wood and the outev 
cast iron, is next described tuid illustrated In this constructiop, 
when all the parts are duly prepared, the combination is effected 
by gently screwing the whole together, as far as the accuracy of 
the workmanship may {permit ; leaving it to be consolidated by 
tightening the screws from tiipne to time, as the workings may 
render necessary, until the ends of the \vedge bolts which pass 
through the felloes, be drawn even with ^be external face of the 
cast iron segments or tire of the wheels. A screw with a proper 
bead is inserted on each end of the axletree, to coniine the wheels 
on the same. 
The same principles are applied to the coftstruction of gigs, cur- 



Mr. Rcmdolph^s Patent ffrr the Consttuciiun of Wheel Cani^gcs. 77 

rides, cin(i all oilier tWD-wheeled Carriages, as well as to artillfry 
carriages, and all other* with fi>ur wheels. ^A description is like- 
wise given of a road scraper, or earth porter, adapted .to the pur- 
pose of scraping soft matter, or removing loose earth, after it has 
been prepared fur the purpose by ploughing or digging : for the 
particular shape and constriction of which, as well as of the other 
macliinery described in this specification, we must refer to tiie 
original and the plates. 

Observations. — A variety of essays have been written on the 
theory of wheel carriages, and different opinions maintained rela^ 
tive to the best modes of constructing them, in order that a givca 
weight may be drawn along with the least force possible, t>om« 
have recommended the fore wheels to be made lower than the 
]j.nd ones, some that they be all of equal height, and others that 
the hind wheels be the least ; general practice, however, is in fa» 
vour of the first of these methods. JNlr. Randolph's mode of 
constructian also coincides with it, as he directs, that the plane 
passing through the a3^i«of the two axletrees be always inclined 
forward to the plane of the hori£on in the constant angle of three 
degrees, whatever be the height of the wheels or the length of the 
carriage. We should have been glad if he heul favoured us with 
his reasons for giving the preference to this angle ; 'and stili more 
so if he had deinoti&traied its superiority above all others for an^ 
swering the desirxfd purpose. Mr. Lambert, in an essay on four 
wheeled carriages, published al Leipzic in the 2nd volume of Hin^ 
denburg's Archiv der AJathematik, in 1795, has shewn that the 
thickness of those parts of the axles, upon which the wheels turn, 
should be proportional to the diameter of those wheels, and that 
the centre of gravity of the loaded carriage, should divide the dis- 
tance between these axles in the inverse ratio of the cubes of their 
diameters* It has also been previously observed, as well as in the' 
present case, that about two-thirds of the whole weight should 
rest upon the hind axletree ; hence, according to I^Ambert s states 
ment, the dimeters of the wheels should he nearly to each other, 
iu the ratio of 4 to 5 ; as the cube of the former being 64 and the 
latter 1$5, which are nearly as 1 tb i2, or the distance of the cen- 
tre of grg^yity from the larger wheels, coual to one-third of the 
whole distance. This proportion for the diameters of the wheels, 
however, does not agree with Mr. R's angle of inclination, except 
the distance between the axletrees exceed 9i feet, 'i'lie circum- 
stance of making the wheels to roll in dii^'erent tracts, (the fore 
axletree being shorter than the hind one) has also an evident ten^ 
dency to destroy the angle which be recommends to be constantly 
preserved, wherever there are ruts made by wheels that follow 
the same tract as in the common mode ; for if the fore wheels be 
caused to run in these ruts, the angle of inclinatioa will be in« 



•7 Afr* Randolph's Patent for the Construction (ffVhcd Carriages, 

creased, and if the hind wheels assume the lower path, it will be 
diminished. One of the principal objects to be kept in the con- 
struction of four wheeled carriages is, that each pair of wheels may 
require the same draught ; this, however, wc think Mr, R. can 
not prove to be etlected by his mode of construction ;. since what- 
ever be the line of tract. on of the fore wheels, that of the hind 
wheels (and particularly so when the body of the carnage is sup. 
ported on spriiigs) will be the line joining the centres of the two 
axles ; and this iiuikes an angle of three degrees with the hori- 
zon, and c6nseqijent ly presses the wheels that support the greater 
part of the weight upon an obstacle rather than iifts it over it. 
Another object to be attended to Is, the diminution of friction be- 
tween the wheels and axletrees ; Mr. R. directs that the naves 
be n^ade of cast iron, and the axletrees of either wood or iron. It 
bas been proved by the experiments of Coulomb and others, that 
the least friction is generated when polished iron moves upon 
brass : the axles should therefore be made of polished iron, and 
the bushes in which they move of polished brass ; in order that 
the least r^tardive force may arise from this cause. 

The addition of the check spring which this patentee makes use 
of, we think will prove an advantage, in both regulating the nK)<» 
tions of the others, and assisting in diminishing the draught. Mr, 
Edgeworth, in an essay on this subject, published in the Transac- 
tions of the Royal Irish Academy, for 1788, oUsenres on this 
head : '^ I apprehend that it is not at present commonly imagined 
that springs are advantages for this purpose ; nor would it at first 
sight appear credible, that, upon a ri>agh paved road, such as are 
common in Cheshire and other parts of Englapd, a pair of horses 
could draw a carriage mounted upon springs with greater ease 
and expedition than four could draw the same carriage, if the 
Springs and braces were removed, and the carriage bolted fast down 
to the perch." The reason of this he states to be, that the springs 
allow the wheels to pass more gradually over the obstacles with 
which they meet in their progress along the road. There is ano- 
ther effect however, which appears to have still more influence id 
the progressive motion of such carriages, than this stated by iMr. 
E. their elasticity causes the carriage to bound upward ^very 
moment through a small space. * Thus its gravity is for that mo- 
ment, in a gieat measure counteracted, and the progressive motion 
which it has already acquired, is at liberty to act more freely in 
pushing it forward; for'were it possible to take away the horses 
instantaneously from a carnage mounted oa springs, and 
moving with considerable velocity, it would continue for some 
time to move of itself; the weight in this case acting as a fly 
upon any mechanical engine, by means of which the machine ae* 
cumulates a certain quantity of power, and will keep itself in 
motion for a considerable time after the band is taken away. 



Mr. DumbeWs Patent for a Method of Flax-spimiiH^. 79' 
the weight of all carriages indeed has some efi'ect of this kind, or 
the draught would require an intolerable exertion of force to ketip 
them in motion ; but the effect is much the greatest in those 
with springs. 



Mr. ^mis'Dv'MJiiiLL.sPatcntfor a Method or Methods ofFlax-spln- 
ningy and of prtparing or f/ia/ci/tg a species qfVarist^ Thready Fur* 
7uture^ Cloth, TriUsy or Attire, which he calls Telary Teguments^ 
from Sil/cf Wool, Cotton, Flax, Hempy or Torr, a.i trelt as from a ve- 
ry great Variett/ of other Articles, in a combined or uncombincd 
State ; and for a Method or Methods of rcfahricating or renovatintr 
the same, and of producing or reproducing from Tatters in general 
a new Bod I/, Dated August 1808. — Repertory of Arfs^ No, 
S4. Second Scries, 

Instead of presei*ving the vegetable fibres of the flax to be ma- 
nufactured as long as possible, and spmnmg the same by the com- 
mon methods now in use, this Patentee cuts the matJeriali into 
such lengths as may render them fit for being manufactured by tlie 
machinery in comn)on use for spinning cotton. For the purpose of 
thus preparing the flax or hemp, he ma"kes use of the common agri- 
cultural machine denominated a chaff-cutter ; and in order that the 
bottom and angular parts oi the flax may be properly cut, he caus- 
es it to rest upon a thin layer of straw, rushes, or reeds, or other 
similar substance, which in consequence becomes cut along with 
the flax. These inconveniences may be remedied by making the 
containing box of the cutter of a circular or other curved form ^ or 
by any other suitable means. Mr. D. also further prepares the 
said materials and renders them finer and more soft and flexible 
by pounJing, rolling, steqiing, macerating, or by any other suitable 
means, and then spins them by thesame engines and in the same 
manner as cotton is spun. He also uses the abo^e mentioned 
materials either in a separate or mixed state, as circumstances 
may require. He likewise states that the materials are rendered 
more fit for spinning by being subjected to a " strong pressure, with 
or without the application of Iieat at the same time, by means of 
presses, cylinders, or other instruments." 

With respect to the ref.brication of the different articles, Mr. 
D. divides them into shreds or. stripes, and again cuts those into 
short lengths, and then reduces them into a loose staple fit for 
spinning, by any of the methods before mentioned, -or by any other 
niechanfcal means best suited to each sepafate kind of materials* 

Obsavations. — A very considerable part of that superior degree of 
strength which linen yarn possesses over that fabricated from cot- 
Ion, undoubtedly arises from the greater continuity of the fibres of 



M Mr. Mantous Patent for mi impruced Gun Lock, 

whkh it is composed, Mr. Dumbeirs object is in a >^reat niea^ 
sore to destroy this continuity, for the purpose of subjecting *,he 
materials to a particular mode of manufacture; but it ouglii \^^ \>t 
remarked, that whatever he may gain in facility of extcutiun, will 
be deafly purchased at the expense o( qualitt/. We cannot th^-re- 
fore, but regard this Patentee's process as a retrograde step in 
the progress of improvement ; which is to meliorate the mode of 
manufacture without injuring the quality of the substance manu- 
factured. 

Whether or not the refabrication of the old materials wilt be at 
all beneiicial to the public, is a question which we shall not attempt 
to decide. It is, however, evident, that the yarn produced from 
tbcm< must be of very inferior quality, while the expense of ob- 
taining it will be increased. It will also greatly interfere with 
the manufacture of paper, which has now become almost equally 
as necessaiy as that of cloth, and in which the scarcity of materi<« 
als has been a subject of considerable complaint. 



Mr. John Man ton's Patent for an improved Lock fot 
Guns and Pistols. Dated Decembery 1809. Repertory 
of AriSy No^ 94, Second Series^ 

In this improved lock, the hammer is fixed to the plate by the 
the same screw which fastens the hammer^spring on the inside ; 
and the hammer-spring pin comes through the plate about |ths 
of an inch. There is a small projection in this spring which 
enters into the shank of the hammer, and Causes it to return to 
its jointing with the pan when the lock is brought to half cock* 
The cock is flat on the inside, is about one eighth of an inch 
thick, and passes between the plate and the hammer when it 
comes down. I'he squares of the tumbler are rendered stronger 
and more perfect by a bulge which is left on the bteast of the 
cock. ** When the cock is struck, down, the flint comes in con- 
tact with the hammer face near the end, and forces it down suf-^ 
ficiently to admit the sparks into the pan. The pan is about 
three -fourths •r seven-eighths of an inch long from the outside of 
the plate/' The inside of the pan is round, and of the same size 
X from one end to the other. . The end of t^e» stud in the main 
spring is bevelled to fit under the nib, to prevent it from rising, 
and the. crane of the tumbler has a roller in the end, on which 
this spring operates. The bridle has a strong leg on the inside, 
< and a stud which fits into the plate near the sear nose, to prevent 
it from twisting ; and the sear shank is nearly vertical, instead of 
being horizontal, as usual. The sear spring acts on a shoulder 
left for that purpose ; and the pan is primed from the touch hole, 
by the compression of the air ;n loadiiig. At that end of the 



n planttng Farxht and otktr Trt€s. -, '^^ 

hatnlner fac« nearest the pan, a email groove is sunk iti the 
.bamuier, to carry off any wet that may come down upon it* >. . .^ 
. TliQ patentee states the fol]owing as the principal advant^c|l 
ivhich are derived from t^s improved lock. First; the pan 
being solid with the plate at top, protects the prime. from wcC 
Secondly ; the hammer opening downwards, and the flint acting' 
in a direct line with the pan, the sparks communicate quicker to 
the prime. Thirdly ; the hammer returns to its jointing wit& 
the pan when the lock is brought to half cock, without any addi* 
tional trouble to the user. Fourthly ; the Ibwness and compact*^ 
ness of the lock altogether rendf^r it much less difficult to protect 
from wet, and much less liable to accidents; by catching in 
cover shooting, than locks of the present construction. 

O^^eiTafioRj.— -Different contrivances have been adopted with 
a view of rendering the use of fire-arms more certainly efficacious, 
and less liable to accidents. Mr. George Dodd invented a simple 
gun lock which could not go off at half cock, and by which the 
danger of missing fire, by the tumbler catching at hcflf cock, was 
prevented. See our first volume, page 63. Mr. Noon lately ob>- 
taiued a patent for improvements on fire-arms, the chief of 
which tras that of protecting the powder from getting w«t. 
This was noticed in our fifth volume, page 379^ It WifH readily 
be admitted that these advantages which this pat^bte^ bad spect* 
£ed as resulting from his improvements, are worthy of being 
attended to in the construction of fire-arms ; and,' as fieur as we 
are able to Judge from the description contafined in the .specifica- 
tion and the figures by which it is illustrated, we conceive that 
ihty may be &rly expected, as consequences of the method he 
has adopted. 



i ^ i i I n il I l egBgagMfcR 



AGRICULTURE. 



On planting Forest and other Treeg, By A. C. R., ofCa$^ 
tie Combe. — Agricultural Magazine, No. 30. 

The method of planting recommended in this paper, which is 
seated by the writer to ha<re been f6llowed with much' success/ 
consists in digging each h6l^ for receiving the trees large enough 
4o receive the roots freely, and in then laying the sweard, which 
ts paced off, at the bottom of the hole with the grass upwards^ 
^ad setting the tree upon it, placing the roots straight and regu- 
lar as in their natural growth, upon which moie sweard is to be 
hud with the grass downwards, and the hole filled tip with earths 
On clay ^oHs it is stated to be improper to go bdow the giiotf 

i^o. 2^3. — VOL. vr. K 



M Oil the Anglo'Mcrmo Quesiim* 

ibould, thoagh it be ever so shallow^ and to be hj^tter to raise 
earth a foot or two above the ground upon the roo^ •f the new 
planted trees, than to go beneath the surface of the clay ; and >n 
a few years the extra expense will be amply compensated 
by the flourishing state and healthy appearance of the trees. 

Obsarvations.'^Thes% remarks, though not new, are certainly 
ingenious; ^nd without some attention to the points recom- 
mended, little success can be expected in planting upon clay 
soils. 



On the Pfice of Anglo Merino Wool, By Benj. THOMPSOif, 
of Redhill Lodge^ Notts. — Agricultural Magazine^ No» 
30. 

This paper states the quantity yielded, and the prices obtain* 
ed for fine wools by Lord Manveis and the writer, in the last 
year. The Ry eland sheep of Lord Manvers yielded about two 
pounds four ounces each of wool, which brought 3«. Sd, per 
pound ; the Merino-Ryelands of the first cross yielded not less 
than three, pounds and a half, which was solA for Ss, 6d, per 
pound. The writer's own wool, which was one third part pure 
Merino, one third part Merino-Ryeland, anyone third unmixed 
Ryeland, brought six shillings per pound weighed together ; and 
this was about twenty five shillings for each fleece. Fr(fm these 
•premises the profit of fine wool is inferred to be deserving the 
notice of agriculturists in general. 

OSser^ations, — The price of fine wools has been so exceedingly 
variable for the last eighteen months, that no general conclusion 
ought to be drawn from what they sell for at any particular peri- 
ods ; but it does seem that the woolbuyers are unwilling to give 
a proportional advance for very fine wools, and as long as this 
continues, their production will necesssarily be limited in this 
amnftry* 



On the Anglo'Meriiio Question. By Aoricola Northumbki£N- 

sis. — Agricultural Magazine^ No. 30. 

Obteroations on the speculative ojm'ons of Mr. Thompson ; and 
experimental evidence of' Mr. Wright and Mr. Hose. By John 
HuKt, of Loughborough.^^Agricultural Alagatiney No. 3!l. 

The first of these papers is a continuation of the long pencting 
controversy relating to the superiority of the Leicester and Me* 



On ike CuUwre of Carres. t) 

ri&o brteds^ sheep ; and the latter consists of comments on aa 
account puHlhecl in a Leicester Newspaper, of some experiments, 
conducted by Mr. Wright of Pick worth, to which we^ormerly 
alluded, and which we had hoped would have terminated this 
tedious controversy : they appear, however, to hii\e been con-- 
ducted in a very unsatisfactory maimer; and tiie subject may 
still aiford matter for the Agricultural Magazine, 



On shoeing ^the Ox and the Morse. Btf Clericu8, of Buckirfg* 
hanuhire, Agricultural MagaztnCf No, ^l. 

This paper is a desultory and whiniiig lan^entalioii over the 
difficulty of finding blacksmiths to shoe oxen, in a neighbourhood 
where they are not commonly used, and a complaint cNf the pKJtt^ 
dices entertained against them by the common labourers in hu8bali<- 
dry . — Relative to shoeing the horse,, the writer says, ." one great 
object is to preserve his feet as nearly as possible in .th« state Ju 
which they were found at his first shoeing; . and to suffer. .tht 
smith .to cut not an ounce mora from th^o than ^s absoluteJj 
necessary for fixing opot the shoe/' 

Observations, — It is difficult for us to conceive that the desire 
of seeing himself in print of the most vain author would not have 
been restrained by the most common discretion from sending to 
the press so silly a production. / 



■^!9SafB^*B99B9^B9qq^q!nR^BinBSBBaS9BBB9BB9BS 



On the drill Culture of Carrots. B^ R. S. D. of fFindsor Forest.-rr 

Agricultural Magazincy No, 3\, 

On the Culture of Carrots, tit/ A.^N. F. of Worksop.-^Agricultural 

Magazine, No, 32. 

The fif St of .these papers contains little except common place 
observations ou the benefits to be derived from the culture of the 
carrot, and a suggestion that they might be drilled on light soil 
to advantage, if any method were known of separating tlwB^edfi; 
so that they might be regularly delivered by the machine : and^tl^e 
writer closes by soliciting information on this i^oint. 

The second paper is in reply to these enquiries, and contains 
an account of a ji^ethpd which .had been practice<l with greEtfsuc- 
cess upon a san^y ^pil, tolerably free from couch grass: The fieM 
vifas ploughed in oojQ-bout lands in the month of Maich or April, 
by which an additional depth of soil was given to the line for the 
carrots, and the ,seied was imiiiediately sown by band* upon the 
middle of each la<id, where, being much higher than the furrows 
they were much ^easier- weeded, as well as preserved for winter usfe. 
These row? were at, two feet distance ium e*ch other; arid in Jliiie 



jl4 Hints relating to etn Improvement on the Thrashing Machine^ 

the intervals, which had been kept clean from wee(ls,^were so^n 
\Vitb turnips, and the turnips drawn off* in autunan as wanted for 
fattening sheep. The tops of the carrots were mown off, and be- 
fore winter, part of them were drawn, and laid between two rows 
Itfft standing, the part drawn being regulated by the quantity ne- 
(fessary to fill the interval wiih a single course, and tben the 
whole was covered with soil only, taken from the outer side of the . 
rows, and ridged up. ^Tbis method was found to Keep them per- 
fectly well iu all seasons, t}iough before it was reported to the 
wrhole crop was frequently lo^t, whether housed or not. 

Ohservations. -—Th^ yfcry simple and easy method pointed out 
in the last of these- papery is well deserving the attention of all 
farm^rS) who grow carrots for winter use ; and we are inclined to 
4iiink that the same plan might be advantageously applied to the 
t>reservation of turpips in a severe winter. And though the most 
advantageous plan appears to us bbvious enough, yet we trust we 
-shall' bie' excused for remarking that the turnips need only be drawn 
t)etween'thote rows where the carrots are intended to be stored, and 
may be left to be eaten off by sheep in the other pairts of the field. 

On coteriTff^s for Hay and Com Ricks » By Economic us, ofAylcsr 
. iury.^r'AgncuUural MagaitnCf No. 31. 

The writer remarks the great benefit arising from covering hay 

.^nd corn stacks in unsettled weather, and recommends the use 6f 

oid sail-cloth, as bestfitted for the purpose ; a practice very comr 

mon in Kent and Surry ; and he conceives, that from the increase 

of inland cemmunlcation by canals, it might be obtained at an 

;fasy price in most parts of the country, • • 

Observations. 'r^Thi^TQ can be no doubt of the propriety of this 
recommendation, but the measure has been long adopted by most 
intelligent farmers. 



m^0m^^mm II il |i I ■ ■ 



Hints relating to an IniprovemcrU on the Thrashing Machine. By 
Alexanper Scott, df Ormiston. -^Farmer* s Magazine^ No. 41 . * 

To remedy the inconvenience frequently found to arise from 
Veaking the straw in such a manner as to make it unfit fdr 
thatching, it is pioposed to select all the tallest and best stand- 
ing corn in the field, and bind it regularly with cords to be set 
apart for that purpose; and to annex to the machine a foot- bar 
pr treadle in a coavenitnt position for the person " who feeds the 
/rorn to the machine" to set his foot upon at pleasure, and thi^ 
^fpN^P. t<>; b^ w cpnpt^cted with the feeding rollers, tha^ he cin 



Frtparatorf Siep to ph/dwg Thum Hedget. '- U 

jslcvate or depress the upper one at pleasare,so as to let tbe straw 
pass quickly through the machine, or retard its progress if that 
should he necessary for perfectly getting out the com. 

Observations. — As hitits these remarks may lead to sonie prac« 
tical improvement in the mind of some other agriculturist; but 
we do not expect it from Mr". Scott, unless he is more fortunate 
ill explaining his ideas, than he has been in describing the mod« 
of applying the treadle alluded to. 



a^fmm^^^J^'^mfi'^S^iBBI^mi^Sm 



On the Potatoe Curl. Bj^ James Inglis, of Parkholm, near G/a#- 

gmp.'^Farmers Magazine y No, 4i\. 

The \yriter having communicated his opi^iops on this subject 
in a former iQagazipe, relates the foUowing experiment, which he 
made last summer. He fallowed a small part of a field in 1808» 
and in August sprinkled it oyer with hot Ume shells, in which 
state i^ l^y till tbd following April, when it was planted with 
potatoes. On an a^j^ining par); of the field some potatoes wer« 
planted in rovys, atn4 each set covered wijth ^little soot, and tha 
rest of the field was planted oi> the dupg only which had been 
laid upon the fallow. The result was, that those planted on the 
lime, and with the soot, were entirely free from the curl, while 
^mong those planted with dung, apd the san^e seed, there were 
some hundreds of diseased plants. This experiment is considered 
As clearly to prove, that the disease is local iand^hot hereditary. 

Observ(ftions, — ^The mode in which this experiment has been 
conducted seems decisive of the question which the writer was 
desirous of )jringing tq issue, and affords a useful lesson to those 
who cultivate potatoes on a large scale, by pointing out the 
means of averting one of the diseases most injurious to that ve- 
getable. 



-VArowi 



JTir 



An useful preparatory step when Thorn Hedges are to be planted on 
• Clay Soils, By 5onjr Reid, ES'q, of Castle Hill, near Kilbride. 
Farmer's Magazine, JV^. 41. 

This preparation is to lay an under-^rain of small stones im* 
mediately ben'eath the line in which the sets are plated, so that 
^ey may always have a dry soil for the roots to shoot in. And 
^here old Hedges want improving in such soils, it is recommendr 
^ to pass drains underneath them, at no very great distances^ in 
a <^ross direction. 



86' On ihe,imttilk|f^ofph^eltmg PoUitoe BloHomif 

Observations. '^■^Thtre can be no doubt but that the advantage 
rfisuking .from obtaining a thorn hedge^ in clay and wet soils, in a 
short period, will more than compensate the additional expense 
ot the drain recommended; and there cannot remain the smallest 
doubt of the efficacy of the plan. 



Estimate of the Expense of enclosing by Hedge and Ditch. By 
R. G. of Perth. — Farmet's Magazincy No. 41- 

On the expense tf endomg by Hedges, By Calc[jlato&9 of East 

Lothian, — Farmer's Magazine ^ No. 41. 

These papers consist wholly of calculations relating to the 
subject of them. The result of the first is, that the loss of ground 
by this fence is, in all cases, more thai equivalent to the differ- 
ence of expense of this mode of fencing: and the other also fn- 
vours the same conclusion. 



Observatians. — As these calculations are adapted to a district 
where stone is plentifol, and where hedges are not raised without 
much difficulty, it should be remembered, that though the propo- 
position may ht particularly^ it may h€ not generally , true. 



OT«cae!=m 



Q^^ the inutility of pl,utking Petatoe Blossoms. By the Reverend 
Charlss FiNDLATEa> of Netplands. — Farmers Magazine , 

No.AU 

The theory, " that in regard to animal or vegetable nature, 
the given quantity of the vis vitae, if confined to a single purpose, 
should exert itself more strongly within this limited spHcrt?, than 
when it is allowed to expand over a larger field of occupation," 
having by its plausibility obtained some followers, and various 
facts in the vegetable world appearing to confirm such a suppo- 
sition, such as the disencumbering fruit trees of their superfluous 
-wood by pruning, to the apparent increase of their prolific powers, 
9^d the destroying the seminal parts of tobacco to obtain, the 
more nourishment for the leaves; an anonymous article had ap. 
peared in one of the ear ly^ numbers of the magazine, in which* it 
was asserted that the plucking the blossoms off potatoes ensured a 
greater weight of crop of that oiseful root, and in which the in- 
ference was grounded on the theory we have mentioned, though 
an' experiment was certainly spoken of. Mr. Findlater, however, 
n^t allowing himself to acqniesce in a single analogical inference, 
determined to submit the-queetion to the^test of direct e^erimeat, 
and this paper contains the result of his proceedings. 



New Plan/or constructing Roadt. 87 

-On the 19th at July, in the last summer, he selected six drills 
of potatoes as equal to each other as could be found, and to a 
certain distance plucked off the blossoms of one alternate drill, 
leaving the next untouched; and whatever blossoms had subse- 
quently arisen on the experimental rows were again carefully re- 
moved on the I5th of August, and again at the end of that mouth. 
The quantity of ground appropriated to the experiment was the 
16'Oth part of a Scotch acre ; and when the crop was dug up on 
the 13th of October, and carefully separated, the weight of those 
whose blossoms had been plucked was 6 stone 11 pounds Dutch 
(117 pounds avoirdupois), and the weight of those left untouched, 
6 stone 14 pounds Dutch (120 l-3rd pounds avoirdupois), making 
a difference of 3 pounds Dutch (or 3 pounds 5 ounces avqirdupois), 
in favour of those left untouched, which is nearly as 38 to 37* 

The experiment and the result being thus minutely stated, the 
inference to be drawn from it is left to the reader; and as it was 
made for the sole purpose of ascertaining the difference upon the 
root, no particular attention was paid to the effect upon the stem 
or leaves; but there was no difference to attract the notice of a 
common observer, except the want of blossom on the rows se- 
lected for the experiment. 

06servation$,'-^Though nothing is more desirable in agricul^ 
tural pursuits than to guard against the seductions of analogy, in 
general practice, yet ,we cannot but consider this as a sufficient 
motive for ascertaining' the existence or non-existence of the 
suspected fad by actual experiment. Nor do we think that a 
single experiment should be relied on as decisive on the point, 
particularly when, as in the present case, the difference . of the 
produce on either side is so small as one fortieth part of the 
whole. 



New Flan for cotisiructifig Roads. By Messrs, Winton and 
NisBET, of Edinburgh. '^Farmer^s Magazincy No, 41. 

The plan recommended is, " that two courses of stone, each 
fifteen inches broad and nine inches deep, in blocks from nine 
inches to two, and three or four feet in length as the different 
quarries can conveniently afford, be laid along the road level' with 
the surface, and at such a distance from each 6ther^ as will suit 
the ordinary width of cart and carriage wheels, the stones forming 
these wheel ways to be of granite, or any other stone of a suffix 
cieritiy hard quality.'' It is contended, that if stones be laid in 
this manner, and well secured upon a hard bottom, they will 
resist the friction of the heaviest machines with complete effect for 



SS Mr. ChtvreuCi chemical Experiments on Brazil and Lffgroood. 

klong period of time ; it is, however, necessary that the road shoaW 
be kept smooth aud level with good materials. 

Qbservatioiu. — ^There certainly are situations in which roads 
made in this manner would be f(iund very beneficial ; but we 
conceive the expense of securing the bottom oh which the stones 
must be laid would more than equal the expense of forming the 
best possible road in the usual way. 



CHEMISTRY and MINERALOGY. 



Ckemicai Experiments on Brazil and Logwood,^ Bi/ Mh. Che vkiu i . 
Annates de Chinned voL 66. 

Brazil wood or Fernambue (csesalpinia crista) is of different 
•hades of yellow and red. Yellow brazil was boiled in distilled' 
^aier, the decoction filtred and distilled till only one filth re* 
mained. The liquor rhat passed over contained a little acetit 
4cid, and some volatile oil resembling that from, pepper in smell 
and taste. The residuary liquid deposited, on cooling,' yell^^Vv 
flakes, tbe greatest part of which entered into a brown viscous 
inass, tasting astringent, bitter, and rather acrid* This mass 
being washed with cold water and treated with alkohol at 56^, 
was for the most part dissolved, and it formed a yellow solution, 
^hich on adding water let fall (lakes, soluble in an excess of hot 
water. The solution being heated to drive o& the alkohol, and 
then added to a solution of gelatine, precipitated it abundantly;' 
alkalies changed it, to violet. The viscous mass also yielded oo 
incineration some traces of sulphate of linke. 

The supernatent reduced decoction was very deep yellow, acid; 
and had a bitter and astringent tdste, which was afterwards very 
^arp ; it was covered with an oily iridescent pellicle; it became 
red ou adding sulphuric, nitric, or muriatic acid, and deposited' 
yellow^ bro\v!i flakes ol colaar and tannin ; it turned violet oft 
adding potash, and aminonia was d i:r en gaged ; it threw down 
from gelatine coloured flakes formed of animal niatter, tannin, 
colour, and perhaps some volatile oil. On being evaporated, it 
left a yellow extract inclining to reddish, which on being burned 
left carbonate of lime and a little sulphate. Of course the infu- 
sion of yellow Fernambue contained, 1, volatile oil ; 2, aeetie 
acid ; 3, tannin ; 4, colouring matter ; 5, ammonia ; 6, Tuxic 
(both these last probably united with acetic acid) ; Jf ^ trace oit 
sulphate of lime, and as it should seem, from their being con* 
tained in the extract made for sale, §, sugar, and 9» gttlUeT 
oeid. 



An infusion of (be wp^ mttde in waur sharpened witb pota 
fisib w«9 vt€4etv 9nd let fisilli on adding very dilute sulplHuic acidi 
BMiny yellonvish brown flakes, which iv hen washed with hot wa* 
ter were neither acid mt alkaline, and wer« a coaibin%ttgn ^o£ 
tannin and colout'^. with ptrbapa Simi^ volatile oil, although thtf 
had not tht tharp taate of it» The supernatant l^or. suU.rt* 
tained tiinnin and colour, aS)d yielded .on distiliatipti ti'^aaoiily o£ 
vinegar. \Vhen the acid had been added ill «xc^a,. the preoipi* 
tato contained some of 4t. 

Muriate of Hme threw duwiii in the Course vf s^m^ hwii1i,..l[M 
purplish precipitate trofn tha infusion i thia precipit^e wp^ m^lH 
abundant and deeper coloured when the muriate wai^ pr#vi<H»ljf. 
talcined. Il lipprai^d to consifti of tanhiiiy Cotoafi: ai^dUoie.ifih 
taining soma okuriatic acid ; '. 

- As the tannin could not be separated from the c^^lour hy th^l 
above processes, cold water was (ried, in which tbip briusii 
wood was macerated for 24 hours. The ^Uered infusion vias: ye)r. 
low, and did not coagulate galatine ; but wbeb it was concentraV*^, 
^ by evaporation, it b^^aipa bitter and i^^ringent^ and immedi^ 
Btely coa^lated 'gelatine. That thi( gelajt^ha was not coagulated 
at first is {uirtly owiag Iq the quantity of waler^ as a Combination 
of taiiniA) c^Jnur and gelatinie. ift more soluble than |be combina^ 
tinn of only lantitB an^ gelatine, and al^o partly to th^ action of 
caloric^ for when the watei" which bad been eVafH>rated aWay was 
lidded to the almoat dry residuum, the tiew solution precipitated: 
gelatine. The analogous eircuoistances that take place whefi cet^ 
tain substances that contain tannin are roasted, have bean aecrib-^ 
ed to the formatiRonof lannin by the rnabting, but it is mbri» 
probable that the taniiin is only separated from some combina* 
tion which hindered its action upon gelatine. 

Alkofaol and ether produce fine yelliiw tinctures containing vo^ 
Jatile oil, tannin, and colour,, and whiieh are decomposed by 
. neater. 

As the Colouring matter could not be obtained qliite pufe^ the 

cold UEifasion which contain^ colour united with a little tannin^ 

acetic acidy and volatile oil» and from whence the greatest part of 

tlie two latter might be separated by heat waa examined. &ilr 

pliuriCy nitric, and mnri«tic acid render the infusion red, and stp«h^ 

rate red or brewnish >ellow flakes ; the laat are colour united with. 

tai^nin, and fall because Uie acid takes away the water that held 

tfa^BB 19. aotutioa ; thawed flakei Cental a portion of the acidi anii> 

perhaps some Af the oiL Carbonic acid do^ not redd^ft the info* 

mk^* Potash^ asupaunia, barytcs, and lime render.ij^ violet, and 

unite with the colour and tannin } these cembioationii^ Stre mgrf^ 

salable • than Uiose formed by the acids* GeSa^inous alnmina 

usiiMkwitb the colour, and forms, a /crimson ^e» between tho 

piok foj^ned by the acid* M>d th^ ^ifilet of the alkalies.. . O^ide pf 

ir«» 23.— TOL. VI. V 



90 Mr. ChevreuTt Expmmdih on Brmi and L^gvmd, 

lih ad mininvum, (precipitated by ammonia, and washed uintif 
that which ii taken up by nitric acid does not precipitate the 
solution of silver) forms in a few days a violet lake ; if an excess 
of oxide is used, the infusion is rendered colourless. Oxide of 
tin ad maximum forms a fine pink lake ; so that one oxide acts 
as an acid, the other as an alkali ; and they have the same effect 
upon cochineal; and the case is similar when the two muriates 
of tin, ad minimum and ad maximum, are used in dyeing. Ox« 
ide of iron ad maximum forms a purple lake,- which appears 
black when it is dried. The smallest quantity of carbonate of 
lime changes the infusion violet red; the in^s'^on also stains 
ittarble violet, without causing any effervescence - in these cases 
the colour and tannin seems to combine with the carbonate 
itself, for the tinge is never so violet i» when lime only is used. 
The operation of carbonate' of lime is so strong upoa this infu- 
sion, that common paper, and also the blotting sort, changes the 
infusion red, and are themselves tlnis* tinged purple, unless the 
carbonate is separated by weak nitric acid, and then the infusioir 
is not altered when filtered, and the paper is tinged yellow.- 
Neutral sulphate of soda, sulphate, muriate, at nitrate of potash 
redden the infasion, unless it contains an excess of vinegar, anlt 
provided that the saline solutions are concentrated, and added* 
in sufl^cient quantity. Salts of Hhie,- magnesia, &e.^ act like' 
the alkalies. Acetates of potash; of lime, &c. change the in- 
jffision to pink. The oxklic and* tartarous acids, and' ^vinegar,- 
only weaken the colour of the infusion, at least if they are not 
very strcmg ; they throw down in time a few flakes, scarcely 
coloured. Radical vinegar reddens the infusion, but not so' much" 
as the mineral acids. Sulphuretted hydrogen gas passed through 
the infusion takes away its colour by degrees, and if kept in it- 
close vessel it becomes white in a short time, but resumes ita* 
yifillow colour if it be heated. Sulphuric acid tntns it red, luid' 
alkalies violet, by absorbing the sulphuretted hydrogen and^ 
uniting with the colour. 

To determine whether the sulphuretted hydrogen disoxygenis^d'' 
the colour or not, htharge (finely powdered, and boiled in water 
to expel any air it might retain) was mixed with Che infosion«> 
previously saturated with sulphuretted hydrogen gas, and thfe' 
vessel was closely stopped: when all the sulphuret was decotn. 
posed by the oxide, the liquid again became yellow, and if it vims-^ 
lefl upon tho oxide for some time, it acquired a reddisbtingft 
from the oxide it took up. Hence it appears that sulphuretted * 
hydrogen forms a colouiie^s^ combination with the colouiing 
matter of brasil. Similar phenomena took place with carbonate 
of lead, so that the change was not owing to the bxygen o( JCb« * 
litharge. When an Infusion which has been enllvetied by •aa a|i» 
isA\ il iMed, 4xA is desnlphiirated by earbonate of lead,* it d#es • 



QOk becone of lo detp a yelbw at be£Dre».ms^tbe carbaaiq iin4i 
combiaes with the alkali and .colour, ami cendQvsit .paAen. .Lite. 
mQ$,(toium*iol) also btcMBts white on bttn§ cianbiaed withlaul-. 
pboratied hydrogen* .These cpmhinatioiis jnay? Ue ^preserved • for) 
a long time in close vessels. Sulphuretted hydrogen seems tor 
Ve the first teriii in the action of acids .upci6 Ui^ infusion. < 

. Vauqoelin bas.showa that litmas ifi.ort^naUy red« but isireo«>' 
dered bLoe by an. alkali, a:;d that Uie Jeduess produced.by acids; 
is owing to their saturatiag the alkali. It litmusipaper is dippedi 
iataan infosion of brasil, which contains little or na vuieger, tfaa< 
paper becomi^s purple on both sides ; this effect is evideotly pro^i 
duped partly by the carbonate of lime in thai paper* To avoid, 
which, the paper was dipped into dilute nitric acid, washed, ren«- 
dererl blue again by potash, and again washed to separate. the 
tmcombined alkali ; and in order to obtain the eolour. iua.sthte 
of purity, the precipitate from the alkaline iniiiiion of brazil hy. 
sulphuric acid was used; this precipitate was washed with fa 
qvantity of water, (which, however, did not ap9>ear an ;triaL to 
abstract any sulphuric. acid), in order to get rid o£ the acetic, acid; 
that might proceed from tba decomposition of the acetate o£ pot«> 
ash formed by tbejuoion of the potash employed y(\\h the .tiaeMi 
gar fxistisg.iDthe wood. The washed precipitate beifigitben, 
dissolved is water^and depurated litmua paper dipped 'in.the.:s(du« 
tion, the paper in about five, minutes, accpiired a xeddish.tiiitt aiid> 
the liquid. »be€Jaaie pink by >.coo>biniiig>i)imib 'thcAliosU. unifed 
vaik the litsius : iheoce the. colour when united. niiUs t^oniaihaa & 
strQii0^r atlraotion for alkalies tban.tbe red.eolouir yA UinitU^ and» 
whiekie very retnaikabie, it acts like an aei4« . >' < . : '. 

..incision, of braail being evaporated,, yieldst. a yellow eitsact 
which had. a reddish cast; like many other ..yellow substanices. 
^R^uen itt a condensed state, ^ oxide ofrquicksilvier ad maximum, 
or of iron ad Biaximum, minhim, chromaie of lead,. &c») but oii> 
ila being redissolved in water it yields ayellow solution as before. 
This extract yields on distillation, water containing free acetic 
acid» ammonia in small quantity, reddishand, fawpcplour joil,. a 
solid purp)]r fat substance that seems to be a combination- of oil 
anil.acttkc acid* and charcoal weighing exactly one half .of the 
original weight of the extract. . . 



♦ . 4 



A dry, reddish hrawo, resiidike substance, of a sweet taste 
at £rst, but afterwards astiingeat and sharp, has been sold for 
9<kme tipoe by the name of extract of brazil wood : it appears 
to be produced by evaporating a decoction of the wood. 

This extract is not entirely soluble in water. The solution is 
brown yeUow>; sulphurie, nitric, or muriatic acid render it rather 
paler, and'if more aoid is added, it becomes pink ; it precipitates 
gelatine by the taanin it containsy it yields ammonia whea mixed 



wUk potesfa^ it alio ^oiitaias oil, awl.ftcti i|i allvccspecl* iil» tKr 
MOlvition^oi nu cMcract of bimzilowliioii had been hattolj evapov 
nitody: >e](cep$ tbat it .was sweeter; indeed- it cuntaioe sugilr, it^ 
on adding yeast to tbeeolutioiit and ktUng. ii fenaeiit, aUfiohol. 
vas obtained. 

The exlvact yielded^ on distillation, waier stigbtly acidulated* 
which when Altered was citsine;. had a sweel tatte, pveripitated 
kon of'U blue colour, and emittecl ammonia when potash -was 
dis^oifedin it; henceiit ivas probably galkte of aoomonlat which 
in eertUR circumstances has a saccharine tai^te : along with thia 
came some small dr6pt$ of russet and fawn oil, and a pttrple iied 
aiibliniate formed of th» oil, the acid, and perhaps sooie f okmr* 
ing niat^r. {t left &6 per cent, of very bulky cbavcoa}, which 
burned with flame, and left 6^ of yellowish ash, oontainiog ^^ of 
parbonate and muriate- of potash, with some traco of sulphate 
fuad 4 of carbonate of lime, alumine, red oxide of iron, and 
filica, . - 

Two parts of nitric acdd at 32^ was poursdupon one of extract ; 
maeh nitrous gas was emitted, mixed with prassic aadcArhonic 
licids. To diminish the action of the acid, 2 parts of water were 
added, and after aom^ time, two more of acid, and the ^aiiUatioii 
continued. Wh^q the hquor bucan^e thick,* sosne water vms 
added, which threw f}o^n a puinber of flakes that were redistoltred 
on applying heat Some sand md stofiea were left behind. 

The filtered solution deposited, pn;coo)ing« a<sahttanoe whtek 
^oUeoted on the sides of thjs vessel in the form of €attltfowcrB% 
^hese fia^es were washed with cold water, afid then disaelittd in 
^ot water ; an orange substance (a) being left, pari of whiek 
poUected on the surfiue of the sohition and grew solid when thn 
jkoiling ceasedi The solotion it^lf depoaite4 by cooking, part of 
what it had taken up (kj; that which remained dissolv^ was 
of the same nature as the la^t, but it contained more acid 
'. The Qimngf spbstaoce, o, hada.slightastringenttaale; it dian 
solved ifoicker in nlkohd than, in water, the solution <hd not r«d* 
den litmus paper,. U a^Mi yellow, and hnpama slightly turbid oa 
cooling. Sulphturicy nitmc, and uiunatic acid, i^thouabt diluted, 
l^eripitated it ; >lii;pf water di<(t not render it turbid ; Wttliea ^ct 
alkaline carbonates, instead of precipitating it, rendered it clear 
if turbid ; these precipitates were, the yeKow substance itself. 
The solu^QUipnfecipit^ted ako solution of silver or of tin^ And 
nreiale of lead; red sulphaterof iron was thfow& down in retl 
flakes, bafr not the aplph^ ad miaimiina, and sohition oi gelaainc- 
was immediataly'CoaiEpidkted. Hence this sobstance a is artiiicini 
tannin onited with the bitier yelloi^ matter, and perhaps some 
nitric acid, lor when it was thmWn upon a red hot iron, it be- 
nama carbonised, and afterwards iimehed and took firiei Uke.a 
misUarf of nilrc and charcoal. 



JMr% Oit^riutM $9f0^mmirm BrmU and tt ^gUM u l , gs 

/ Tbe 8«bstaiice6^fori»ed % white aediment, of a ciiit>o tin^t^ it 
tatted somewhat <acuit ^^^ afterwardt astriogcnt- and bUtar. 
When it was flang upon iron of a proper heat, it took fire and 
ocploded : at; a IM bMt it either burned hke wildfire or it tnelted, 
and part of it was soblimed in the form of a yellow powder ; at 
a greater heat, it burned with flame like a resin. ^It disaolved inr 
nitric acid at 3S^ by heat,- and a part was sepfurated by addiog 
water ; the tc^ation, on evaporation, produced a brisk daae aa 
soon aa it got dry, and it yielded much prassic ^cid. A solutioa 
of this substance in water w>s acid, and precipitated gelatine in 
large flakes ; it tlterefore^uiained tannin, and 'also bitter matter 
.wbieh cottkl be separated by adding to the h(>l concentrated 8». 
luc^n, pure poush ; after this addition, on cooling, small needle- 
hke. crystals were deposited, wEkh detonated when heated, and 
were of a deeper orange than the •detonating crystals from indigo: 
from this detonatiRg property it is probable tfaiat the subeUmce ^ 
also contains some nitric acid. So that it contains the same 
principles aa the orange substance a, but in diflinrettt praportionS| 
as the fomaer seems to contain more tannin and lass bitter or 
nitric acid than- the second ; but- it is not ualikejy that the 
fix«t contains some other principles which were not dtacofvered, 
on account of the smallness of the quantity that was operated 
upon.' 

. Two grains of the detonating crystal^ placed in a small mar- 
trass upon hot coals^ gave a report equal to that of a pistol, a 
purple flame that extended 2 metres (yards) from ibe matrass* 
and a white vapoor, part of which remained in the vessel. On 
pouring green sulphate of iron into the veMel, it deposited Prus* 
sian blue, ^om the aciioo 4^ the vapour ; and this deposition 
was still more abundant if some alkaline water was poured inter 
th« matrass, so ^at npt only prussiate of ammonia, but also 
prussic acid was formed during the detonation. These detonating 
crystals render gelattiie f^urbid, evenaflber they have been crystal* 
Used twice, on account of ^beir ^till retain'mg tannin. 

The mother water from whefice th^ ciUtltflpwer4ike flakes had 
been idep^sitedf was evaporated to dryness, and the residuum 
traatad with boilin^^ water. If yielded a yeikw •solution which 
Je^, on being j^ltered, oxalate of lime; the filtered liquor contaiu- 
e4 bitter, tannin, oxalic acid, and much ammonia ; it also coa. 
casaed potash, as appeared on i^eberatipn* 

The extract of braaii did not produce in dyeing such bright 
eoioars as aa iafuMon of the wood . itself, so that the colouring 
nsatter appeared to have been iqored by the evaporation- being 
fioo hasty. 



I ■ ♦ »■ i i II 



f he colouring matter* of logwood app^ra nearly similar 



■ys. 



V • / 



94^ Mr.4^0o^«^^ }afiffSmmt$^tm BnM itid^JLoglDodi: 

tib th«t 'of htfaih ftB'ltinds iaiid'alWttli«8 jmMla^e^tlie ftedie effects 
upon k, %Qt itictallte siib^Mes produce^ other effects^ the cMfte*' 
<if whkh aire iidt v/kAl known. ^. ■ ' . ■ 

Od 'diitillkig an infofion %>f logwood^ It yielded vviktile oil not> 
cmitahihig any acid. The liquor mnaitiing in 'the retort did not- 
pedden litmus, but it pKCtpitated ^ekttne. A few,dro]ps of eok 
]>b«iric, nitric, or nmriatic acid tunwd-it yel)im,''bnt an excess of* 
these acids changed it pink, time and p«^ash -were discovered 
in the extract by incinerating it; and ihe.c^xtrac^ yielded vinegar 
on being distilled with dilute sulphnvtc acid./ > 

If the action of the mtnefal salts, acetates, and vegetable acids 
upon the colour of brazil h considered, it is easy to explain the 
change of colour produced by roitieral acids in- the red infusion 
of brazil or of logwood, for the acid tirstdecompeseA the acctites 
contain^ in the wood, and the aceticFi^aieid that is disengaged 
renders the infusion yellow ; but on adding more naineral acid, it 
acts on the colour and forms a pink combination. The colour 
of the wood, whether yellow or red, may also be explained, for 
saturated acetates form a red combination with the yellow com- 
bination of tannin and coloar ; an<|'weak acetic acid renders the 
latter combiilaticm paler than before.. Now the yellow wood haa. 
an excess of acid, and may therefore be considered as a combina- 
tion of tannin, colour, and acetic acid; but the red wood con- 
tains saturated acetatea instead of free acetic acid; and th4^ 
orange wood, aceii«»acid with more or less neutffil acetate ; > fotf 
a neutral acetate pourednntiran infusion of yellows bflisil, which 
holds^an excess of acetic acid, changes it red' notwitlistanding 
the presence of the acid. 

The colour of some very old biiazil was but little soluble io^ 
water, which arose from the volatile oil being changed into 
resin, and thus, combining strongly with the colour, it hindered' 
the free action of water, or even of the acida. Hence it is pro. 
bable that the colour of red saosders is similar to that (>f brazil,^ 
and is a combrnation of resin and colouring maitter. 

The action of neutral salts, ar those' with a slight excess of 
acid upon the colour at. brazil, seems to depend more on the 
base than on the acid. Thus if two pieces of stuff are treated, 
the one with, common alum, and the other with acetate of alu-- 
mine,' and then dyed with brazil, nearly tlie same colour will be 
produced, notwithstanding aulpharic aeid'fprmsa.puik colour,, 
and acetic acid a yellow one with the infusion* 

Therais reason to believe that many combinations of colour 
and tannin exi^ t in nature, and jthat the yellow colours that pre* 
cipitate glue are of this kind ; hence the usefulness of passing? 
cloths to be dyed through ba^hs of gelatine, and even oi tannin 
'}% evident, for in many cases the eoloat' may not be saturated! 
with that principle. 



Mr^CkmtuVM txfenoktut$ on Bi^izil and Logwood. 9$ 

' At sonie.fatikre. timf the application of these exp^imeats to 
the opeiatioD* of dyemg wiii be giveo, and tU« causes of the difie* 
xences that are observed in the action of the same substances upo& 
4»ra£il and k^wdod will he investigated* 

. Fresh experiaients have lately- been made to separate the colour 
of Bracil fnom the tannin, by means of gelatine. . When acleai 
aolatioa of glae is poured into a' yellow infusion 'of brazil^ it it 
ciianged .to.viokl red, on aceouat ot' the glue containing some alka- 
line salts ; on the «»ther hand, a solution of isinglass renders the 
infusion paler, because it contains an acid^ to get rid of which the 
isinglass was disf»o)v(Hi in water and precipitated by alkohol, 

A yellow iuiuskou oi braail made wildiout heat was then eva? 
porated to dryness, to get rid of seme of . the acetous acid it con-t 
tailed; the t^xtract was then redissolved in water,, and shook up 
akng witli litbaiga to separate the remainder ; the solution being 
a|>aiu evaporated: to diyness and treated with alkohol, did not 
take up any of th^kad ; it was yellodr withareddiah tinge, arising 
Drom some neutral alktdine acetate tha.t it contained. To sepa''ate 
this, the solution was mixed with ^ater, and heated ; to drive off 
the alkohol 4>urified gelation was then added, and the solution eva* 
porated to dryness. On treating this last residuum with alkohol, 
a yellow liquor wa9-nb(^ed which did not contain any tannin, so 
that the pur^ colour of ^ brazil appears to be yellow. When cloth 
was dipped into a solution of the pure colour, it was dyed yellow ; 
and if while moisi it was put into, .water acidulated with sulphuric, 
nitric, er munaticacid, it became pink ; but if put into an alkaline 
water^ it changed to violet. 

If -there is only a very minute quantity oi acetate in « yellow 
iafusion of brazil along with an excess of acetic acid, the action 
of the salt will be very feeble until the acid is taken awi^, and 
then the acetate that remains renders the infusion deeper coloured. 
For the same reason, a drop of a mineral acid weakens the colour 
of the yellow infusion, as it decomposes the acetates of lime, ammo- 
nia, and potash that it contains, and the ac'ctie acid added to 
that already contained in the. wood, reacts upon the colour, and the 
more ao as neutral uiiaeral salts have less action upon the infusion 
than vegetable. 



On tkeMetais of Potash and Sodi'-^Bf Mess. Gay Lussac and 

N TmTtARDJ'^Afm. de Ckim. vol, 66. 

...' '••., •">■ • 

Dav^t concluded from hi| expanmantS; that alkalies arecompo- 
stdof axyi^n and a very inftammaUe metallic substance; but there 
are as many reason^ ;to suppose that these metals are comhina- 
tienaoi the alkali with hydrogen. 

Thtmet^saraohtained by ^vanic procesles in such small quan.L 



96 Oh the Meials of P4ftmhmi4 Sodd. 

ities that tlie discovery of the method tti procuring it, by €CUtinfi( 
he alkali to act upon iron, mutt be regarded at a fortlllMl^ cit 
ciimttance. The process has already been given in ths Retrosptct, 
vol. iv. p. 465, and therefore it need not be repeated. The metal thus 
' obtained may be purified by being paaied through linen under 
naphtha, by the aid of heat and compression. It is then pure, 
and may be preserved in oil. If charcoal, or any thing which con«i 
tains that substance, is employed to obtain the loatal, it retains 
some of the charcoal and varies in its properties. 

The metal of potash resembles lead, but may be moulded by th« 
fingers, and it cuts still more easily than phoephorua. Its specific 
gravity is .874. When ilung on water, it takes fire and moves 
about slowly on the liquid; towards the end a slight explosion 
usually* takes place. 

The metal that was produced in an iron tube, in one of these ex* 
pehments, augmented its weight %84 grammes (about 59 oz. 
Troy), andyiekUdt on water being introduced, 64892 cu)). centim. 
(about 5960 cttb« ia*> of hydrogen, at 6^ therm, cent *(4t° Fahr.) 
and the baium. at 30 inches J6 centimetres. 

This metal combines with many other metals, particularly iron 
and quicksilver. On combining with sulphur or phosphorus, 
heat and light are disengaged, and when*tl|e compounds are flung^ 
into water, tbey yield respectively sulphuretted and pbosphuretted 
hydrogen. 

It burns briskly in oxygen gas, and Is changed into potash.—* 
' In common air it changes of a fine blue, and on being shook it 
melts, forms a brilliant liquid, and takes fire ; the oxygen of the 
air is absorbed and the azute is left. At a high temperature, it 
absorbs a large quantity of hydrogen, and forms a whitish grajr 
solid mass, from whence the hydjogen may be expelled by quick- 
silver or water. At 70* it separates phosphorus, sulphur, or 
. arsenic from their combination with hydrogen^ uniting with thenci» 
and also absorbing d portion of the hydrogen ; this deeompoaition 
is made without fiume even in the case of phoephuretted hydro- 
gen. It burns as quickly in nitrous acid gas or oxymuriatic acid 
gai as in oxygen, but the flame is sometimes prevented from ap- 
pearing by the metal becoming covered with muriate or nitrate c^ 
potash. 

This metal also changes blue, and tak^s fire in nitrons gas, gas- 
eous oxide of azote, sulphurous wid gas, carbonic acid i|rtf and 
gaseous oxide of carbone procured troip a mixture of carbonate 
of barytes with iron. The three last gasses require, however, a 
higher temperature to be decomposed; The nkmoegas and gaseous 
oxide of asote Uave pureasote; thesulphsrous aeid gat yields' 
snlphorat of potash, aad no gastoos residua*) ; the carbonie acid 
gas, and gaseous oxide of carboat yttkl' charcoal and potsilfr, 
without any gas. It has . np actios^ 9p .fittoric acid gts ilnlaaa 



On the Action of Phosphorus, Sfc, on the Alkalies. 97 

heated, and then the metal, burns very briskly, absorbs all tbe gas, 
and is changed into a blackish substance, which does not HTer- 
vesce with water, and which contains fluate of potash, and a little 
charcoal contained in the metal. 

Many experiments have been made with the metal and ratlriatic 
acid gaSy but the gas has not as yet been obtained in a state of 
perfect dryness. On treating calomel with phosphorus in order to 
obtain the acid in that state, a very limpid colourless liquid was 
obtained, which emitted much vapour, and took fire when blotting 
p]^)er was moistened with it. This liquid appeared to be a combi* 
nation of phosphorus, oxygen, and muriatic acid, and of course an- 
alogous to that obtained by treating sulphur with oxymuratic 
acid gas. 

All the preceding experiments may be explained either by 
Davy s hypothesis, or by supposing that the new metal is a hy* 
drogurettof potash ; the following requires the Tatter explanation. 

Metal of potash heated in dry ammoniacal gas over quicksilver, 
is changed into a greenish gray very tusible substance ; the great- 
est part of the gas is absorbed, and about 2.3ds of its bulk of 
hydrogen is left in its stead. If tbe greenish gray substance is 
heated, 2-5 ths of tbe ammoniacal gas that was absorbed are ob- 
tained, and the elements of another fifth ; a few drops of water 
causes the expulsion of the remaining 2-5ths ; no other gas is se- ^ 
paratedf and pure potash remains. The ammonia expelled from 
the greenish gray substance may be again united with the metal, 
and the operation repeated, so that by a given quantity of ammo- 
nia there may be obtained more than its bulk of hydrogen, without 
any loss of the ammonia. It has been already shewn that the me- 
tal does not unite with azote, and if equal quantities of the metal 
are treated with water, or ammoniacal gas, ea<ch portion yields an 
equal bulk of hydrogen, so that the hydrogen must either come 
from the metal, or the \yater contained in the ammoniacal gas, and 
as in the latter this ^as must coutain more than its own weight of 
water, the hydrogen must come froiii the' metal, which is of course 
a combination of potash or of hydrogen. 

06«ervflf?o»«.— IVlr, Davy's observations on this theory of the 
formation of the metal of potash may be found in our volume 
IV. p.'422. 



On the action of Phosphorus and Oxymuriatic Acid Gas upon the Alka- 
lies. — By Messrs. Bouijllon Lagrange andyoGis.L. — Aj,n, de 
Chim, vol. 66. 

SoMEyears ago it was observed, that when a.sojution of caustic 
potash acted upon phosphorus, it emitted at fi^st.alarge quantity 
of phusphuretted hydrogen, andji?ft a blackish residuum ; while the 
^as that was disengaged towards tbe end did not tajl^e fire by oiere 

HO. 33,—VOL. vu . o i . ' 



$8 On ihe action of Phosptoruiy S^e. on tkoAtkaliit. 

contact of air. The late discoveries respecting the alkalies renJcT 
this observation of iniportahce, and it became necessary to repeat 
it with care. 

The phosphorus was first reduced to powder, by melting it in wa- 
' ter, and shaking the vessel till it became solid, which was hastened 
by plunging it into cold water. The water being decanted off the 
powdered pbospl^orusydiluteoxymuriatic acid was poured upon it to 
separate any carbone it might contain, which rendered it white. The 
acid Was then separated, and the phosphorus dried by btotting paper. 

The purity of the alkali was assayed by lime water, and barytes > 
water. Lime water if it has a superfluity of water, is not precipi- 
tated by an alkali that contains a little carbonic acid, because the 
carbonate of lime is retained in solution, which is not the case 
with the carbonate of barytes. It has been long known that caus- 
tic potash precipitates lime water, and that the precipitate is 
soluble in water; whence it was supposed to be pure or caustic lime, 
but it is reatly (inely divided carbonate of lime, which is not taken 
Dp because it contains an excess of alkali ; for if carbonic acid gas 
be passed through lime water, the precipitate thus formed is solu- 
ble in water, although the liquor is neutraT. 

The potash was reduced to powder, and an* equal quantity ef 
pulverized phosphorus added to it, in a glass mortar placed in a 
mixture of snow and common salt to prevent the phosphorus 
fro n taking fire. After a slight trituration, the mixture was intro- 
duced into a luted stone ware retort, and slowly heated. A portion 
of the phosphorus takes fire on account of the air contained in the 
vessel ; but this may be avoided by covering the mixture with 
some powdered potash. 

At the end of the opciration, the inside of the rifttort was covered 
with a metallic looking coating like blacklead ; and it contained a 
black mass which had a slight alkaline taste; this was but slight- 
ly soluble in water, but was all taken up when boiled, except a 
black powder. Nitric acid, by boiling, also dissolved it, and left 
the same black oxide of carbone^ These solutions contained only 
phosphate of potash. 

In one experiment, this black mass had no taste, and was not 
soluble in water, as it was neutral phosphate of potash : but nitric 
acid dissolved it, and separated oxide of'carbotie ; the tube connected 
with the vessel was lined with a grayish mass which took fife by 
contact with water. 

In repeating these experiments, potash and soda were alter- 
nately employed, and the gas that was disengaged was neither acid 
nor alkaline, but had a slight sniell of garlic. It burned with a 
white flame, andyielded on combustion a little phosphoric acid,and 
oxide of phosphorus. It detonated when mixed with oxygen 
gas and set on fire. It did not take fire on being mixed with air» 
oxygen gas, or nitrous gas. It was slightly soluble in water, and 
the solution precipitated nitrate of silver of a blackish colour. . It 
took fire immediately when mixed with oxy muriatic acid gas, B.nd 
then deposited a little oxide of phosphorus ou the bell glass. 



Double Refraction of the Cry^aU of Sulphate of Copper, '59* 

This gas may bejobtaiued with much ease, by putting some dry 
phosphorus into a phial, and sprinkling it with very dry caustic 
potash. On heating the phosphorus, white vapours are disengaged 
and the gas is emitted. If a little water is added, phosphuretted 
hydrogen i« produced as long as any moisture remains, but as soon 
as the matter becomes- dry, the forenientioned gas is emitted. 

1 he following experiment gives s(»me light on these pheno- 
mena: pure potash was ignited by a white heat in a porcelain tube, 
and oxymuriatic acid gas was passed over it ; as soon as the gas 
touched the potash, agreat deal of water in the form of steam was 
produced, which also contained carbonic ocid ; oxymuriatic acid 
gas then passed over, and this also precipitated lime water and 
h^rytes water : towards the end the passage of oxymuriatic acid 
gas ceased, and a mixture of oxygen and carbonic acid gas was 
disengaged. 

The carbonic acid gas that came over during ihe whole opera- 
tion was cloudy, and much too large in quantity to be contained 
in the alkali, which had been previously examined, and which, al- 
though it could not be entirely frefd from the acid, yet it pro,- 
duced only a very slight cloudiness in barytes water. Of course, 
hydrogen and carbone appear to exist in the alkali. 

A small quantity of muriate of potash is sublimed in this pro* 
iCess, which is sometimes of a pale green colour ; the weight of 
this muriate is much less than that of the potash employed. 

An account will hereafter be given of the phenomena that oc- 
cur, when hydrogen an(} oxygen are made to act upon potash. 

D6ierra/»*/w .—The^e experiments are very important, as they 
seem to shew that the alkalies are combinations of hydrogen and 
carbone, which, considering their formation de novo in vegetation, 
is more than probable on the first view of the subject. 

/ 






On ihe double Refraction of the CrystaU of Sulphate of Copper. jBfy 
Mr, pRiRUil.-— J«it. de Chim. vol. ft*. 

The form of the crystals of blue vitriol seemed to indicatte that 
they possessed the property of double refraction, but their general 
want of a sufficient transparency has hitherto prevented it from 
being observed. Crystals, however, have at length been ob-. 
tained sufficiently transparent, and these possess this property in 
a very manifest manner. 

A line joining the two images of a point viewed througn ai 
crystal of blue vitriol, is in a direction nearly perpendicular to thA 
edges of the prismatic envelope of the crystal. 

The slight efflorescence which so soon tarnishes the surface of 
these crystals generally prevents the observation of this property*.!. 



( 100 ) 



•k>«* 



On the manufaduf'e of Charcoal in close Vessels, and on bringing 
into use the various Substances that are produced in the Operation, 
By Messrs. Mollerat. — Ann. deChiinie. vol. 66. 

Thrke brothers have established at Pellerey, near Nulls, Cote 
di'Or, a manufactory on ajarge scale for making charcoal in doser 
vessels. 

The quantity of charcoal they obtained is double that of the 
usual mode, while it requires only one-eighth part of wood tfl be 
consumed in the distillation ; it is also better than the comHony 
as a given quantity evaporates one- tenth more water than the 
other ; hence iron masters may obtain twice as much iron from 
the use of a given quantity of wood, and in addition to this there is 
also prepar«d a number of other articles, of each of which in 
order. 

350 Chiliogrammes (700lb) of wood, yield 25 or 30 of tar, ^ 
which retains so much acid that it is soluble in water; but when 
it is washed, and rendered thick by boiling for some time, it offers 
more resistance to water. If mixed with one-fifth of rosiu it is 
rendered equally fit for the usa of ships, &c. as the common tar. 

Four sorts of vinegar are prepared, all of which are perfectly 
limpid, which do not, like the common, coi^tain any tartar, malic 
acid, resinous or extractive matter, nor indeed any mineral acid, 
lime, copper, or other substances. The simple vinegar marks—. 
2° hyd. for sails, at 12^ therm, cent, it is stronger tasted than 
common vinegar, and produces a , disagreeable irritation. The 
aromatic vinegar is prepared with tarragon, the smell is agree- 
able, but it has the same fault as the former. The vinoljs vinegar 
is formed by addiug some alkohol to simple vinegar ; it has a very 
sensible odour of acetic ether ; the alkohol softens the flavour ia. 
some degree, but the vinegar is still very sharp.' The acid, called 
strong vinegar, is- in feet a very good acetic acid at 10^°*hydr. it 
is very white, cl^ar, and sharp, without the usual burnt flavour, 
and seems to form the basis of the preceding kinds. It can be 
S0I4 for 8 or 9 francs (7«) per lb. which is only half the price of 
that distilled from verdigrease. Although not so agreeable to the 
taste as common vinegar, these new kinds are more elegant to 
the eye, and do not mother. 

Carbqnate of soda, perfectly white and transparent, is niade at 
this manufactoi^ ; the greatest part of this salt that is used does 
not require so much purification, and if the price will allow its 
. Ufiing brought into use, 60'per cent of the expense of carriage 
* i$ay be saved by drying it thoroughly before it is sent ©ff. 
• • The acetate of alumine thai is prepared here is not sufficiently 
pure for the use of dyers, asr it contains the sulphates of lime, anU 



On Awmi^m NapeUus. ICfl 

^f iron, vvhkh last is very prejudicial in dyeing : bnt by using good 
alum in its preparation* this iniglit be avoided. This acetate is 
also turbid, and contains a white deposit probably of alumine^ 
which ought to be avoided. 

Acetate of soda in well formed, very white, and pure crystals. 
It is not of much use, unless physicians should substitute it in 
the place of acetate of petash. 

Acvtate of copper crystallised in small grains, more brilliant 
than. common verdigrease. It is entirely soluble in water, and 
much cheaper than that in present use. > 

Acetate of barytes perfectly pure ; it would be preferable to 
acetdkof limefor preparing acetate of alamine, if it were not too 
dear. 

Muriate ef alumine is said to be preferable to alum in dying, 
but that prepared by Mess. Mollerat is excessively acid, and con* 
tains lime and oxide of iron, which renders it useless in many 
cases. 

Oxide of zinc of a dirty white, and containing oxide of iron, 
and a little carbonic acid, which it appears ta have absorbed after 
it was calcined. 

Carbonate of zinc, rather whiter, but which also contains some 
irou, although the carbonicacid hides its colour. 

Both the two last substances might be used by painters instead 
of white lead. 

Besides the above, the proprietors intend to make white lead, 
and also sugar of lead. 

A cubic metre (yard) of wood yields one hundred litres (quarts) 
of acid liquor, besides the above %5 Or 30 chiliogrammes, (50 or 
^OM.) of thick oil. 



Ohscrfat/'ons.-^The proprietors of this manufactory seem to be 
perfectly awaie of all the several productions which could be pre- 
pared from the refuse of their principal object ; an'd we have no 
doubt but that the substances they procure in this manner will 
amply compensate them for the use of the capital that must be 
invested in building the furnaces. 

The nature of the vessels in which they distil the wood is no| 
mentioned, hut they are probably cast irou retorts, or vessels of 
a similar nature, in which a distillation per latus takes place. The 
application therefore of Lord Dundonald's furnaces for procuring 
coke to this purpose would be sull more advantageous. 



mmaiL 



Qn Jcunitum Ndpellus. By Philip Anthony Stein acum,«— 
Joam. de Pkys. Mar^ 1808. 

FkisK leaves of cultivated aconitum naoellus, (early blue wolfs 
)»ane) treated with water at 45® of temperature, yielded coagu* 



\ 



1 (tt Syrian, Jsclepias^ as a Piant that may he iued instead of Cotton 

lated green fecule. The supernatant liquor had a herhaceoui 
smell, resembling that of cochlearia whe^ it is'ratber withered, 
and which it lo^t entirely on evaporation ; a granular substance 
was separated during this operation. 

This substance being washed, dried, and exposed to the blow- 
pipe did not melt, but became whitish, without either puffing up, 
or decrepitating. Another portion effervesced with dilute sul- 
phuric acid. ' The liquor yielded soft needle-like acidulous vys- 
tals, decomposable by nitrate of lead, and producing a precipitate 
reducible by the blowpipe on charcoal, exhaling at that time a 
phosphoric smell, accompanied with a slight brilliancy. 

The extractive liquor contained a large proportion of mufiate 
of ammonia. Aconitum napellus therefore contains green feculse, 
a atrong snialling gaseous substance, whicn is supposed to be poi. 
sonous, muriate of ammonia, also carbonate and phosphate of lime. 

As the neighbouring plants did not contain any phospbale, 
aconitum possesses the power of forming phosphorus, or its ele- 
ments, and of converting it int* acid. 



On Syrian Jsclcpias, as a Plant that may be used instead of Cotton. 
By Mr, Sonkini.— Jowrw. de Phys, Mar. 1808. 

The interruption of communication with the colonies renders 
it of consequence to turn the attention of farmers to those pro- 
dvctions which may be reared in Europe, and supply the place 
of those now brought from beyond sea. As to cotton, its place 
may be supplied by a very hardy plant, the Syrian asclepias, 
which unites the production of both hemp and cotton, may be 
cultivated on very poor land, and when once it has come to its 
full growth, will require no other culture than to keep it clean. 

This asclepias is to be first raised by^ sowing the seed ; the 
young plants must either be covered with straw, ur leaves in the 
winter, or they must be housed : the second year they may be 
cultivated by their shoots, which are very abundant. The plants 
should be planted out at four feet distance each way. 

This plant has been cultivated for some time in Silesia. ' The 
day's work of land in Silesia contains|l80 sq. rods, or 18,000 sq, 
feet, and holds 4500 plants, each of which yields on an average\ 
20 pods ; 30 pods yield, after the usual loss is deducted, half an 
Quncc of silk, therefore the whole day's work will produce 93 lb, 
and 12 half ounces, worth oqe rixdollar. 8 groats per lb. or 500 
prench livres (about 21/.) for the whole produce. The gathering 
of these pods about the end of October, does not interfere with 
tl^e other hurrying times of a farmer's business. 

The principal produce of the Syrian asclepias, is the silky down 
ty{ the seeds : this down is about an inch, or an inch and quarter 
lon^* La Rouviere, in IjG^^ manufactured several article^ fron^ 



Kesearckes upon tkt Formation of mttatlk Vectridiy. 103 

it, particularly flannel, superior to that of England. It has bteii ) 
said, that these cloths were very liable to cracks, but it is more 
likely that , the then inferior price of cotton was the real cause of 
the down of asclepias being neglected. The difficulties arising 
from the shortness of the down could easily be overcome, now 
cotton is so dear. The down is employed in Silesia to make 
stockings, and other hosiery. It is also mixed with silk, and 
this mixture produces very beautiful stuffs. It is also used there 
to make coverlids, to stuff cushions for sophas, as also for beds, 
chenille, hats, &c. 

When the pods are collected, the stalks are cut down, as close 
to the ground as possible ; and then treated as hemp, either in 
pits or in the dew ; they yield a very fine white thread. In Ame* 
rica these • st^ks are used to make paper, and other articles of 
that kind. 

From the flowers of asclepias^ the Canadians extract good 
brown sugar ; and they are very agreeable to bees. Dr, Barton 
has found that they act as a flytrap, and catch the flies that are 
attracted by their smell, by means of vaives which are very irri. 
table. The young shoots are eaten by the Americans as aspara- 
gus y and the leaves are applied to cold tumours. 

Observations. — The difficulties that the French find in communi. 
eating with their own colonies, in consequence of our naval supe- 
riority, has led them to turn their attention to substitute articles 
that may be grown in Europe, instead of the traasmarine products. 
Although at present the difficulty of introducing new articles into 
trade, has occasioned them to proceed but slowly in this career, 
yet it cannot be doubted but that the use of these articles will go 
oh in a continually accelerated progress, and operate a consider 
rable change in the commerce of the world, by reducing it to much 
narrower limits than at present, and rendering each of the large 
states more independent of foreign commerce than heretofore. 



Researches and Conjectures upon the Formation of metallic Elettricityy 
or "what is called Gakanism. By B. G. Sage. — Journ, de Phy» 
sique, March 1808. 

The emperor Napoleon was so struck with Galv^i's experi« 
ment when repeated in^his presence, that he not only caused a'gold 
medal to be struck in order to commemorate the discovery, but 
also proposed a prize of 60,000 franks^ the contention of which 
produced such interesting results, that the emperor gave two me- 
dals of the value of 3000 franks each, to the authors of these dis- 
coveries. 

A satisfactory theory of galvanism can only be obtained by 



\ 



154 > On the formation qf MttMic EledrkUy, 

employing as few metals as possible to procure it. Zinc, Watef, 
air, and silver are the most useful. The galvanic power of cop* 
per being unity, that of gold is 1|, of silver 2 ; besides 'silver is 
not attacked by pure water, which is an advantage. Round dbci 
of metal are preferable to those'having angles. 

Lassone has sh?wn that zinc is decomposed by water, and be- 
comes covered with a white calx. When filed, it acts upon the 
'file like an acid. The calx of zinc when newly made by defiagra, 
tion, is strongly phosphorescent^ for more than an. hour. Vitriied 
calx of zinc, from the furnaces at Freyberg, yields sparks wb^n 
rubbed with a toothpick. Filings of zinc, imoiersed in water, 
swell, and emit ah inflammable gas. Wl^en Ktnc i^ filed it is 
phosphorescent, but this phosphorescence is still more sensible 
in the oxide as already mentioned, which is as strong as the elec- 
tric light in an exhausted tube. 

When zinc and silver are brought into contact under water, a 
part of the zinc, as was conceived by the Prince Primate, is de^ 
composed, and a caustic calx is produced, whose astringent taste 
nearly resemliles that of corrosive sublimate, and the shocks of 
which produce still more pain in the joints than those of common 
electricity. 

The calx of zinc that produces the effects of the galvanic pile 
is reduced in the air, and yields electricity and a metalliform 
phosphorus. A smell of phosphorus is sensible even in using the 
common electric machine. 

This caustic metallic calx disengaged from zinc, is very differ-* 
ent from the gray calx that is formed at the same time. Mr. 
Davy discovered that when the alkalies are placed in the cirrle, 
a metalliform and very fusible kmd of phosphorus was obtaioed, 
from whence he concluded, that the alkalies are composed of oxy- 
gen and a metallic substance ; but it is more probable that tbe 
calx of zinc is thus reduced ; and that the acid of the calx renders 
the alkali caustic. All metallic calces contain a caustic acid, 
besides that which is necessary to tjie calcination of the metal. 
This acid and the water causes an effervescence when minium is 
reduced by the blowpipe. , . 

Another beautiful experiment of Mr. Davy is, the decompo- 
sition of salts ^y galvanism, in which the acid previously combined 
with the alkali is displaced by' the caustic acid, and is collected at 
the positive pole. 

It may be said that this formation of caustic acid is a mere 
assertion, which may be classed with tlie thousand and one hypo-' 
theses of tbe new doctrine, because iron and silver also produce 
galvanic effects, although in a much weaker degree Rinnaann has 
shewed that it is very difficult to obtain iron perfectly free from 
other substances, and perhaps it contains a salt which #S6tsts in 
produciNg electric eifects. Ztnc and iroB' b#ing the only metallic 



Oh a SyksiancB faund (n tie island of Caprea, lO^ 

Mtbstancts that yield mftumnabie gas on tolutioBy ^ppwt tooiNF 
thii property to a similar principle. 

Sigorffne has 'stown io bis Esiunen fumttmi dt h tUmk modernef 
just puUashed, that ths thldrjr of thi» comfi^itioo of water it in>* 
admiasible, and bats given birtb f(i a saperfetation of hypOflbesi»s» 
Tessier's Eitm mw la iMork des ifois 4lm€n$^ publisbed in lt04» 
cooturs ill tbe same truth'* 



mAMUMbiAi 



O^jerro/itfsi.— This paper bears evident marks of tbe.sMiility 0^ 
the aothar. The aeidum caustitnm of Meyer lids* b^eti' long c6n- 
signed to obliviom among sft^st c^mists^ and i^ ii»i likely toM 
again taken into favour by anyaitempt of Mr« Sttga t^ briag fl^ 
once more upon tbe stage. 

On a Substance found in iht island of Caprea, j^ Sfr. iLAUQisk* 

Ann, de Chitn, vol. LXVI. 

' Thts substanee waa first observed by Mr« Briesloek, on €fa« 
•ides and at tbe bottom of a ea^ in the island of Caprea^ whieir 
is more than an hundred feet deep, and of which the sides i^ra 
nearly perpendicular. It is black, shining, in round lumps, or iti 
a aUdactilical fM-m, and adheres so much to the rock that it ca» 
only be separated by a hammer. Its smell partakes of that of 
tan, castor, and cow's dung. It contained stiff hairs of a fallow 
brown colour 13 cent, lon^, and small white crystals, of a cooling 
tasOe, and wbieb melt upon burning coals like liakpetre. When* 
flnng on tbe fire it softened, and burned like fat. 

Warm water dissolved more than a half of tbfie substanfce, and 
t^ solution lefi„ om evaporaiion, a shavp Mated extntet, of the^ 
same smi^ as before, which attracted moisture, and whon tdiaced 
with sulphuric acid difiused an acid snwll difficult' tor deseribe. 
The watery solution of this extrarc was preerpilated. by the ni* 
trates of stiver and of barytes, muriate of platina,, and by tiacteni 
of nutgalk: no trace of ammonia ' was observable. The dri0i'> 
oxuraat yielded <m distHtotioa ad ammdniacal li^uov, fotid' oi^ 
carbonate of ammonia, and efaansoal coataining m^riarte' of potaMr^. 
and potaah itself, arisiing probably from composed nitrate a/ pietrf^ 
SMh. When disttlled wiOi dihile sOiphvric add, the dried eeetvsKt 
3rieldod some water, oil^ end needki-Hke tiystals, wlneh^ oa beirif 
resoblmed, were evidotfily eoiia)>oeed of pure benzoic acid, nor' 
Uiat tlie attraction this ^tvatt has for t^otstrnw arose faomtiasr. 
contain]^ benaOHt of potash. 

Tfaer vesidoam, whkb did not dhteolve ifn water, yi<Med to alleeu * 
faola-siDMll ^aaotily ol resiiii noe exceeding onei ^ teat of tba* 
cNrigtai^ wviglKL The^ reoMikidev i9«a oaly a mixtufo of haira; * 
«nall pieces of straw, and some fragments of carbomMof'Mnd- 

»o. 23.— TOL. TI. JP 



1^ On tnetallisuig Potash and Soda. 

md of flinty proceeding probably from the rock to which it acU 
hered. 

The benzoic acid found in this substance assiinilates it with 
the dried urine of h^Tbivorous aninsals, but what animal of this 
kind could descend, into this grotto ? . The hairs have the greatest 
resemblance to that of the marmot, or they ma^ be those of bats, 
which abound in Italy, and may perhaps pass the winter in this 
cave. The chemical nature of the urine and dung of bats is un* 
known at present. 

On account of the resemblance in smell between this substance 
and castor, the latter was examined« and found to contain benzoic 
acid in about the same proportion. 

Observationar^lti a future number of the Annales de Cbemie 
are inserted two other papers on this subject, by which we learn 
that this substance arises from the snails that creep into the cave 
and cannot find their way out, and also froni other small animals 
that accidentally get into the cave, and being entrapped, as it were, 
perish : but the apthors of the present paper are not thoroughly 
satisfied of the truth of this representation. 



On a Pfotess by which Potash and Soda may be metdfised vnfhout the 
intermedium oflron^ Sf^c, By Mr, Cvkavdav. — Ann, de Chtm^ 

vol. Lxri. 

If, according to the hypothesis. of Mr. Davy« potash and soda 
are metallic oxides, it is probable that. the calcinations prepara- 
tory to the formation of Prussian blue are nothing but modes of 
combining the n^vf metals with charcoal ; and ipdeed.it has been 
found that the alkalies may be metallised by heating them strong- 
ly with cliarcoal. 

\For this purpose either of Uie following two mixtares may be 
nied. . Four parts of pulverised .animal charcoal with three of. 
calcinedy. but iiot melted, carbonate of soda, the whole .to be mois*. , 
tened with a little linseed oil, or two parts of flour may be mixed 
wiUi one of carbonate of soda, and. some linseed oil; in. neither 
case, should the oil be in sufficient quantity to form a paste* The. 
mnistened powder, is to be introduced into a stone ware or iron, 
rttbrt, and the heat gradually augmented until a fine bke jflame' 
with,a. greenish border appears in the cavity; to this succeeds a very. 
aiiundanl smoke which darkens the. inside of the vetsel» and is in 
fact the new metal. The fire cannot now be augmented, for, at 
this (Murticularte^nperature .the retort begjins to melt: the iron re- 
torts resittrtbfi fire the longest as ithe ajkidi does not act ^upon; 
them Jo.miKfa as apon eattbeni and the hfat also passes through . 
thw easier. 



Experinunis m Indigo and Wtmdl 107 

On- account of this d<^licacy in the operation, three penont are' 
required to perforin it. One introduces a cold- rod of bright iron 
into the hollow part of the vessel, which becomes covered with 
metalloid, and almpst immediately withdraws it and plunges it 
into oil of turpentine kept-co(4 by standing in a tub of water. The 
second blows the /ire and maintains it at an equal height. The 
third collects the metalloid from the n)d8, plunges them in water' 
to cool \hem and separate the alkali that might be formed, and 
cleaus them in order that thB iirst may have them ready for hie 
use. 

The production of this metal does not arise from the disox-' 
genisement of the alkali, but it is a new combination^ in which 
hydrogen is coniamed in a very condensed state. 

During the operation hydrogen and non- metallised alkali are 
volulilised, as also a large quantity of prussic radrcai gas. So 
that either hydrogen is a constituent]iegi)edient of the alkaliee 
whi^h is disposed to separate by mean^ of the charcoal, or else' 
charcoal contains hydrogen. 

Observations.'^n this paper, as in all other continental ess^s, 
the metalloids from the alkalies are considered as hydroguretn; • 
and not vyitlio^^ some reason, wbcui we reflect on the 9niail spe.: 
cific gravity they possess. The experiments on ammonia and. 
quicksilver hav.e shewn how a very small quantity of rasttei^ iB 
capable of altering the properties, of. the substance to which it ia: 
added ; and the presence of water, to afford a. sufficient quanti^; 
of hydrogen is evident from the experiments that have been' re. 
cently made on potash apparently dry. Davy's own experiments 
on muriatic acid also shew in what a latent state a large propor* 
tion of water may be concealed; and we apprehend that the do. 
cimastic experiments of that chemist were not made on a scale* 
sufficiently large to afford accumte results, . . - « 



jaa^ 



Ckemcal Experiments on Indigo and Wood, By Mr. Chevreul. 

Ann, de Chim, vol. LXVL 

An abstract of the first part of this paper, which treats of in* 
digo has been already giyen in the last volume of the Retrospect,] 
p. 12399 from the Journal de Phvsique. The second part treate 
chiefly of woad, and of this an abstract is now presented to pw: 
readers. 

Woad hasia very sensible smell of tobacco, and whe^ the liMPope 
are broke, they are found to contain fragments of leaves* wo<Miy 
and sand. When distilled it yielded a watery liquid that reddened 
litmus, also sulphur dissolved in an oil, carbonate of ammonia, 
come traces of prussiatei yellow oil, smelling l^e distilled .§ni|i[ial 



wvk&UtuMg^nsid ivbich became brown and'cencr^U by the air; |^ 
bulky coal kvhicii 3?ielded alkaline ash«s, and gasses. " Hie tracef 
of prussiate were dt&covered by a paper impregnated with sulphate 
of ire^n ad minimum, whicb, being soaked in t)ie liquor, e^rveseed 
^kb dilute sulpburic acid, and was ebanged purple in spots. 

Twenty grapcunes (twp tbirds of an ounce) of voad being dis- 
tilled wMb four decilitres (a pint) of water^ yielded a scented 
water neitber acid nor alkaline, but containing some sulphur, 
which was probably dissolved by a ' volatile oi^ for when oxy-^ 
muriatic acid was added to this water it precipitated nitrate of 
1>U7tts. The water ^id not blacken metallic solutions, but paper, 
impregnated with carbonate of lead, became black on being sus« 
pendedoverit* 

The woad remaining after this distillation was exhausted by 
means of repeated additioiis of fresh water \ the first washings 
were reddish, the second yellowish : it was reduced by thb means 
to 13*2 gramm(^8. 

The first washings, being diluted with sulphuric acid, yielded 
acetic acid and muriatic acid ; distilled with potash it yielded 
i^mnonia. It reddened litmusi and sulphate of lime was found in 
it; by using nitrate of batytes and oxalate of ammonia, nitrate of 
^ver threw down a precipitate partly solnUe in nitric acid. 
Ammonia only deepened the colour ; muriate of tin and acetate 
of lead. separated colouring extractive matter. Acid sulphate of 
ison also deepened the colour. Nut-galls separated flakes of ve- 
gsto-^ttiimsil matter. ' 

The remainder of the washings was evaporated, brownish pel- 
licle* were deposited, and other flakes remained suspended. It 
was then filtered and again evaporated, and afterwards mixed witl^ 
alkohol^ Tbe alkoholic solution had a sweetish and slightly 
bilter taste ; it became covered with pellicles oi extractive mat- 
ter^ on exposure to the air, and yielded some crystals of nitrate of 
potash. 

The woad that had been washed with water was treated with 
boijiog alkofaol. The first washings w^e deep green, and depo- 
sited, oh cooling, flakes of that wax which accompanies the green 
fecula of vegetables, and which has been found in many barks, 
particularly that of the cherry; \Afler this, the liquor being fil*. 
tered and evaporated, deposited a blue fecula, which was evident- 
ly indigo : the reniain 1x4; liquid retained a portion of thij$ adong 
with some green feculu' ' The second washing w£is not so green*. 
but rather blue. When concentrated in a retort, they deposited 
siiu^ purple scales of indigo j the supei4)£^tent liquor beiAg filter- 
ed and evaporated, deposited, when slowly cooled, smsdl white 
grains adhering tt> the bottom of the retort, and fl,ake8 of tbe 
same substance were suspendjpd in the reniaiuing liquid* Thia 
wlnle matter became blue by contact of airi aud'even under the 



fiquid if it were exposed to the sun, so tbat this singalw tnhu 
stance was probably indigo at a niinimiim of dxidiisenieiit* 

It required a considerable quantity of alkohol to exhaust the 
yoad, which was reduced by this means to il grammes, and 
which were only woody fibres mixed with sand. 

Hence we may conclude that woad yielded to water, '54 per 
cent, composed of sulphur, acetous acid, extractive matter, gum« 
vegeto-animal matter, sQlp^iate of lime, iron, nitrate of potash, 
muriate of potash, and the acetates of potash, lime and ammonia; 
ito alkohol, 1 1 per cent, composed of wax, indigo ad maximum 
and ad minimum, and green fecula ; the remaining 55 per cent 
being woody fibres and sand. 

The iiidigo in woad is probably contained in the plant, for the 
preparation of this dye stufi^ is not likely to have pitiduced it, but 
only to- have oxygenised that contained in the plant, and to have 
jkrmed the acetic acid and ammonia. But to avoid all doubts, 
the plant merely dried was examined. When treated with water, 
it did hot yield any nitre, and it yielded more muriate of potash 
than ther prepared woad balls : the free volatile alkali Uiat it 
Contained restored the blue colour to litmus that had been pre* 
viously reddei^ed by an acid. In other respects it yielded the 
same as woad balls. The plant which had been exhausted by 
water yielded wax, indigo ad maximum, and green fecula to alko- 
hoi. So that indigo exists ready formed in the phuit, and the 
case is evidently the same in the indigofera, in which however it 
IS at the minimum of oxidizement. 

By the observations of LechenauU it appears that at Java, 
they make a kind of indigo which is superior to that formed in 
the usual nnauner by fermentation. The plant is washed to 
separate the dirt, and then boiled in copper pots containing about 
7 or 8 quarts of water, until the water acquires a green colour. 
The water is then poure^d into earthen jars holding about 80 
or 90 quarts, ^nd beat up until the scum appears blueish ; the 
fecVila is then peripitted to subside and afterwards dried. 

Indigo certainly exists m many plants, although it has not 
hitherto been noticed, because its characters have not been suffi- 
ciently laid down. It may be discovered by leaving the expres* 
sed juice of a plant exposed to the air for some days, and then 
evaporating it ; the indigo will be separated as a blue or green 
powder, which will yield a purple smoke when placed on' a hot 
iron. It may also be dissolved in sulphuric acid, with which 
indigo forms a permanent blue solution. 

If the indigo is mixed with green fecula as in wnad, the plant 
must be exhausted by water, and then treated with boiling alko- 
hoL The first solutions contain much of the fecufa, but the 
succeeding ones, which are blueish, contain more of the indigp. 



110 On the relation betweefi the oxidation ofMetali^ 

ii thes^ solutions ai^e evaporiited a^lmost to dryness^ and alkohol 
again added, it will take up the fecula and leave the indigo; 

Indigo ought to be looked for in galega officinalis, (goat's rue) 
from whence Linnaeus says a fine blue colour is extracted; and 
in scabiosa succisa, (Devil's bit) from whence the Swedes pre- 
pare a blue fecula by treating it in the manner of woad. The 
plants which yield permanent green colours probably contain, 
besides indigo, a yellow colouring matter. 

Observatiotis. — In addition to the tuperiar quality of indigo 
which is prepared by boiling, Mr. Chevreul might have added, 
that this process is free from the unwholc^some efHuvia whicl)< 
have been partly the occasion of the culture of indigo having 
been given *«p in the British West Indian colonies, as we are in- 
formed by Edwards, in his history of those colonies, as tlie va- 
pours arising from the putrescent vats in the old method produced 
a great moitality among the negro .workmen employed in the 
manufacture ; the colouring matter is oxygenised in this process; 
by the continual agitation given to the liquid, instead of waiting 
ibr the absorption of the oxygen from the atmosphere whilst the 
liquor remains in a state of repose, and thus infects the air with 
its putrid efHuvia. 



X 



4. ^ 

On the relation that exists hetweai the Oxidation of Metals and 
their capacity of Saturation for Adds, By M. Gay Lussac,— • 
Mem. d'Avreueil, vol, II. 

The object that M« Ga[y Lussac purposes to pursue in this 
memoir, is the demonstration of a principle, that the quantity 
of acid in metallic salts is directly proportionable to the quantity 
of oxygen in their oxides. The results of analysis are not 
sufficiently exact to be employed. The evidences are derived 
from the precipitation of one metal by another. 

When acetate of lead is precipitated by a plate of zinc, the 
metal is thi^own down in its metallic state ; little or no gas is 
produced, and the solution suffers no change as to its neutral 
state. Hence it follows that the 2inc Saturates all the acid of 
the solution when it is combined with all the oxygen of the 
oxide. 

Similar phenomena are observed if sulphate of copper is preci* 
pitated by iron, or acetate of copper bylead, or zinc, or if copper 
precipitates uitrat of mercury, cobalt, or silver. In iall these 
cases the oxygen and acid of the metallic salt precipitated pass 
into thie metal, occasioning the precipitation. Of course the 
Quantity of oxygen in the sailt formed, is th^ sdme as was in that 



and their capacity of duration for Adds. ' 111 

d^ecomposed, and the proportion of metal it contains is inversely 
as the affinity of precipitating metal lor oxygen. 

Some instances occur which present different results. Thus 
the action of zinc on muriate of antimony is attended with the 
evolution of Iiydnigen, becaase this Salt, to remain in solution, 
requires great excess of acid; and muriate of zinc dissolves when 
nearly in the neutral state. 

It is possible that a salt formed by the precipitation of one 
that is neuti'al may possess an excess of acid ; in this case, oxide 
is mixed with the precipitated metal. 

Lastly, the precipitating metal may decompose the acid of the 
salt, and produce a complicated effect. Zinc has this effect on 
nitrate of copper, it throws down the copper, partly in its metallic 
fetate,, and partly in ihe state of oxide. But these particular 
instances do mot oppose the general principle. 

There is every reason lo believe that metals at the maximum^ 
like those already considered, and at what Proust calls the mini, 
mum of oxidation, have their capacity of saturation propor* 
tionable to the oxygen that in tliis state they contain. Only a few 
facts can be brought forward in support of this generalisation^ 
because highly oxidated metals form salts of difficult solubility. 
Mercury converts corrosive sublimate into calomel, and white muri* 
ate of copper is changed by exposure to the air into green muriate, 
and an oxide containing a litile acid, convincing proofs that per* 
oxides require more acid than proloxides. Mild mercury is f(»rm* 
ed by the .repeated distillation of mercury and corrosive sublimate 
without the .emission of either acid or oxygen. Hence it is evi* 
dent that the acid in both salts is proportionable to the oxygen 
in each oxide ; the analyses of Mess. Fourcroy and Thenard con- 
firm this, and the analysis of the muriates of copper by Proust 
and Chenevix lead to a similar conclusion. 

The principle that the acid of a salt is proportionable to the 
oxygen of the oxide is of great importance, as it affords an easy 
method of ascertaining the proportions of metallic salts, which 
in general are very uncertain. The only data necessary are, the 
proportion ^ oxygen, combined with the metal of each salt, and 
the^composition of ojoe salt of each genus. • Tht muriates will 
afford an instance. Muriate of silver contains, silver 100*00: 
oxygen, 7*60; acid, 25*73 ; and J 00 of lead require, according 
to M. Berthier, 7*39 of oxygen ; the proportions therefore of mu- 
riate of lead, according to calculation, are 100*00 lead, 7 '^9 ^^y* 
g^n, 24*68 acid* The proportioii of acid, according to Mr. Kir* 
wan'a experiment) is 24'Q3. t «Agaii» 100 of mercury at the m«3(r 
imum is combiiied with S*21 .p£;oas»ygen; from calculatioa it 
should unite, in corro/si^ie. sublimate > with S8:l6. of^acid;. ^M 
from .the^ e^pf rimeiAjts of : Tbennrd a^d^Fourcroy, this 8alt'€0|i«' 
tains. 27*39 of acid. 



112 On the retoHon between the oxydation qfMetdU^ 

It is curious, that tbougb the acid of the salt is proportionable 
to the oxygen of the oxide^ the proporcion of oxide bears no rela* 
tion to the oxygen of the acid : for when sulphite of lead is eon- 
irerted into a sulphat, the oxide is,'te before, just Ruflicient to sa* 
turate the whole of the acid ; on this circumstance, and on the 
fact that sulphuric acid may be converted into two parts in vo« 
lume of sulphurous gas and one of oxygen gas, the calculation 
for ascertaining the composition of the sulphites principally de» 
pend. The affinity therefore of sulphureous acid is to that of 
sulphuric acid, as the weight of two parts of sulphurous gas, 
plus one of oxygen, is to the weight of two parts of sulphurous 
gas. Hence sulphit of lead appears to be composed of 100*00 
lead, 7'29 oxygen, 30*30 acid. 

The proportion of oxygen in metallic oxides is as easily ascer** 
tained as the proportion of acid in salts. It is only requisite to 
know the quai^tity of acid in each salt, and the composition of 
one salt in each genus to find out the* quantity (of oxygen in all 
oxides. For inUanee, sulphate of lead, from the analysis of M. 
Berthier, is composed of 100-00 lead, 7*29 oxygeii, 3771 acid; 
and sulphate of barytes, according to the same chemist, is com« 
posed of 66*5 barytes, 33*5 acid ; therefore 100 of the metal of 
barytes require 10*77 of oxygen. 

Lead, silver, and mercory, at the minimum, contain very little 
oxygen, and they form with most acids insoluble and neutral 
salts. This insolubility results from the general law, that a 
compound which possesses much of .an insoluble principle, is 
more insoluble than one which contains less. O^^muriate of mer* 
cury is very soluble. If the oxides of all metals were very soluble, 
the salts that they might form would be perfectly neutral. For 
the excess of acid which occurs in some salts is foreign to their 
Saturation : it is only pecessary to prevent the precipitation of 
the oxide by destroying its force of«cohesion. 

In the precipitation of metallic solutions by sulphuretted hy* 
dfogen, either alone or combined with an alkaline base, *tbe 
hydrogen combines with the oxygen of the oxide, and the sulphur 
with the metal ; therefore there should be as many metallic suly 
"pbureta aa there are metallic oxides ; but at the latter are fixed* 
the varietiea of the fbniier should likewise be determinate. 



OAfervo/UHii.— The remarks of Mr. Oay-Laissac on the precil- 
pitation of one meld by aiiothtr, ai^ new and inteneetiiigy and 
we conceive that they fally pr«ve the truth of the prmeifxie 
whieh he endeavours to eetabiith: in respect to sevttral sdits ; bfit 
they affiipd no evidencea that it is a general law, eqCMdly appltea* 
Me in all eases. A great exesption to it appears in the ssb and 
soper acid sails ; M\tam can tha qaantity of acid in a metalHe 
salt be proportional to the Qxygen in the oxide, when the same 



r 



, and their capaciftffor the saturation of Acids, 113 

bxide is capable of combining with different quantities of acid* 
6ome of these sub and super acid salts are so dtbtihct in tbeir 
properties and well defined iu their formation, as not to admit 
of being considered as mer6 mixtures of the neutral salt \«rith ah 
"Excess of acid or base. 

NVhether the principle be Original or not, is another cot^Mdera- 
tion. 'Judging from appearances wie should be inclined to deter* 
mine in the negative, but we are unwilling to make the accusa. 
tiou of plagiarism ; this is certain, that the priority of discovery 
belongs to Mr. Diilton, who, in his Elements of chemical Philo« 
6ophy, referred to by Gay-Lussac before this niemoir was pub* 
lished, has applied the converse principle, viz. that,thei quantity 
bi oxygen in an oxide is proportionable i^o the acid in the-sblt, 
to calculate the proportions of oxygen in potash and soda. And 
that the principle is deducible from Mr. Dalton's general hypo- 
thesis concerning combination in definite proportidns ft evident 
pn the slightest consideration. This gentleman infers,' that a salt 
which contains a metal at the minimum of oxydation is (to use 
his expression) -a binary coriipound of one atom of oxide and ode 
of acid ; now asit is well known that metals at the maximum of 
oxydation require more acid than when at the minimiipi, it fol- 
lows, of course that sa]td in which the metal is in the former 
state, must be ternary compounds of one atom of oxide and two 
atoms of adid. M. .Dalton's hypothesis has the advantage over 
that of Mr. Gay-Lu«sac> it admits of one atom of a body con»- 
hining with one, two, thre*, or more atoms ^f another bo4y for 
ivhich it has an afiinity. The merit of Mr. Gay-Lussac consists 
|>rincipally in advancing a part of Mr. Dalton's hyt)otbe$i8, in a 
more intelligible form, ilinstrating -it by a variety of instances, 
and pointing out its application to the determination, of tJie pro* 
portions of metallic sal tfc4 One v^ry curious fact is mentioned 
in this memoir j which deserves particular attention as connected 
with the important and recondite subject of chemical affinity. 
We refer to the conversion of sulphit of lead intb a sulphat, with- 
out riny changv^ of the saturating power of th6 acid being pro^ 
diiced. li is evident from this that the additional portion of 
oxygen does not a<fect the original affinities which united the 
oxide of lead and sulphureous acid. We have no doubt, if there 
t^rere accnrate data for calculation^ but that ^Iphuret of lead 
would be found to have the same relation to the sulphit'aa the 
SuTphit had to the sulphat ; that is to say, that lead is combined 
With the same quantity of sulphur in the sulph\iret, sulpKit, and 
sulphat. 

The truth 6f ihe hypothesis employed by Mr. Gay-Lussac to 
explain the insolubility of s*alts wtf shall venture to call iti ques* 
tiori, notwithstanding the high authority of Bertbollet, who fir^ 

NO. 23. — VOL. Vl. Q 



k- 



114 * Anafytis of a Uatk jiandL 

advanced itr The facts in opposition to it are as many noa^lf 
as those in its favour, arid ibey ati'ord objections that cannot be 
remoived. In salts, for instance, at tlie luaxiraum of oxydation« 
the attraction of cohesion, as Mr. Gay-Lussac reonarks, is sq^ 
powerful as to require an excess of acid to keep them in solutioi^ 
whilst the salts of the same metals Itiss oxidated are easily solu* 
ble. But the contrary should be expected from the hypothesis, 
as the proportion vi the soluble el^qi'ent is much suialler in thip 
latter case tha^ in the former. To take particular instances ; 
thi" insolubility of sulpbat of b^irytes is not to be compared wit^ 
that of 6u\ph4t of silver, yet, according to Mr. Gay^-Lussac's cal- 
culation, s^lp^at of barytes contains most oxygen and acid ; oii 
the contr^y, muriat of barytes is very soluble, and nmriat of 
silver quite insoluble — facts ^Uogetber inco^ipatible with the 
prin^pfe that a compound vy^ich possesses (tnich of an insoluble 
elem^iiit is more insoluble than on^ which contains less, 

ii J ■■ ■ - ■■* 



^ "p^p w m 



=*-p*r- 



Ckcpticat atialym of a hlaek San^yfrom the River Dec in Aberdeen' 
sJ^ire^ 0d of a C^P^f" 0)re jroin Arthrey ik Sferlingihire, 
By Thomas Tl^0^I^»ON, A/. Z)., Lectvrer on Chemistry, Edin. 
burgh.^Trans. Edtd. Sec. Vo{. VL Farf IL 

The black satid, independent of the quarts felspar and mica with 
. which it it xnhced, consists of two kinds, one of-'whiclli i^ called 
iron sand by Dr. Thompson, and th(e other iserine, ; the iron' sand 
does not exceed one-fourth of the mixture ; it Is disiin^uished 
from iserine by being strongly attracted by the magnet j^ tts spe^* 
cific gravity is 4*766, and that of iserine 4*49 1, or;fr^ from ex* 
traneous matters, 4*964. Du G. obtained from 100 graius of 
iron sand ^ . . . i < 

-of black oxide of iron , . . 

white oxide of titanium . 

arsenic • - • • • 

^ilica an4 alumina « «• f 



9S70 grs, 
12-65 

1*©0 

1*50 



Total ii3-85 



The increase in weight is a^ttrihuted to an absorption of ojcyge^^ 
by the products. Dr. G. conclu^e^ from his experimeiits that 
ircin in most of its ores is comhiped, with between ij i^nd l^P^ 
cent, of pxygen ; this combination he considers as the real pf oloxr 
ide of iron ; he presumes too from analagyi that there is a fifth 
oxide intermediate between tbt green demonstrate^ by I'henardi 
und the red* 



I 

( 



AnaLfsis of a biack Sand, 115 

I)r. G. having found that white oxide of titanium loses | of iu 
weig)it by its conversion into red oxide, and that red oxide wheh 
raised to the state of white oxide increases exactly one^third^of 
^ts weight, is disposed by these 'facts conjointly with th^ exc^|i« 
tion of Vauquelin and Hechl to consider the three known oxides 
as composed of the following proportions of metal MA oxygen. 

Metal. Oxygen. 

1. Blue. 100 16 

2. Red 100 35 

3. White 100 49 

On the suppoMtion th^t the titanium is in the state of red ox. 
tde and that th^ arsenic and s ilex and alumina detected are fo- 
reign to the cothpositidn of the iron sand, Dr. G. infers that thfs 
pre is composed of 9 p^fts of prcrioxide of iroa and one of red 03d« 
ide of titanium* 
' )00 grains of iserine afforded by analysis, 

of o.\ide of titanium' • • « 54*8 
oxide of irwii - - - - 46*0 
oxide of uranium , . - • 4*2 

silica - - T - - l6*^ 
alumina - *^ • * • 3*2 

Total 125- 



Pr. Tfion^son reduces ^bc weight of the products, to nearly that 
pf the original quantity, on the idea that the one is only composej^ 
of protoxides. Excluding silica and alumina, he concludes that 10^ 
parts of iserine contain nearly 48 tichanium, 48 iron, 4 uranium* 

The ore of copper which Dr. T. examined was a species of 
grey sOlphuret that readily tarnishes on exposure to the atmos- 
phere ; from his analysis he considers its composition as folloy^s : 
iton, 51'0Vcopper, 19*2; arsenic, ^5 7 ; sulphur, 14*1. 

From the appearance of the ore he conceives it to be a mix- 
tiire of sulphuret of popper and arsenic pyrites. 



O^ervationSn'^Tht arguments which Dn Thompson employs toi 
prove the existence of a new oxide of iron, are certainly demon* 
strative, if the results of his analysis areallowed to be accural^. 
But their accuracy is doubtfiil, from several sources of error which 
his methods exhibit. For instance, we find that the iron sand 
was heated to redness for two hours in a porcelain cru^rible with 
twice it's weight of carbonat of potash, is it not probable thei^ 
that the silex and alumine which appear amongst the products, 



ix6 Analysis of a hhitk Sand. 

were separated from thecrucible, and not derived from tLe mineral F . 
•—The strong action ot'carbonat of potash upon crucibles of this • 
de^erijltion is too well known to need any comment. Again, we 
perceive that Dr. G. added ammonia to the muriatic solution, to 
throw down the oxide of iron, before he had precipitated any alu- 
mine that might be present j and that he neglected to digest the 
precipitate in caustic potash. May not the increase of weight be 
attributed to alumine, either derived from the crucible or mineral^ 
and thrown down mixed with the oxide of iron by ammonia ? 
Volatile alkali is commonly employed to obtain alumine in its 
pure State, and it id rather strange that Dr. G. did not take in this 
instance t)<e same precautions in estimating the propottioh of 
iron, as he adopted in the Succeeding analysis of isehne* Beeides 
these cfbjections to Dr. Thompson's conclusion, it might perhaps 
be expected that the iron after being J:reated with alkali wt>uld 
afford hydrogen during its solution in muriatic acid^ if it existed 
in the mineral in a state of oxidaticm inferior to that of th^ black 
oxide precipitated by aiUmonia. But on this we lay little stress, 
as the iron niay he said to be converted from the proloxide into 
theblaffk oxide, during the operation by the decomposition of the 
water that the alkali may be supposed to contain. The numbers 
that Dr. G. has given in estimating the proportion of oxygen in 
the different 6xides of t'tanium, perfectly agree with Mr. Dalton's 
very ingenious hypothesis, concerning definite* proportions and 
fcorabinatiotis by multiples. Dr. G. must, we conceive, have had 
this hypothesis in view, for without it's assistance we db not un- 
derstand how these numbers could be obtained froiii the experi- 
ments which he mentions. The estimations in their present stattf 
can be of little Service until established by accurate experiments; 
Though in tlic analysis of iscrine we cannot perceive any new 
cause of error, yet we are inclined to attribute the great increase 
of weight in part to alumine and silex, separated from the cruci-- 
ble ; a new oxide of iron is not t6 be admitted without good evi- 
dence of its existence. We hope Dr. Thomson will repeat the: 
analysis, for though we may doubt his first results, it \Vbuld b€ 
difHcult for Us to refuse our assent to the second experiments of 
o excellent a chemist. 



No. XXIV. uil! be published Augiisi 1, 1810^. 



JtETBOSP'ECT 



OF 



PHILOSOPHICAL; MECHANICAL^ 
CHEMICAL AND AGRICULTURAL 

DISCOVERIES. 



■SB 



■■^— — ■» 



No. XXIV.] 



Aprily Mai/, June, 



Lisio. 



KAT15RAL PHILOSOPHY, ARTS, ani> MANUFACTURES; 



()n the Volcanoes ef JoruUo. Etf Alexander Humboldt.-^ 

Joum.de Phys, vol, LXIX. 

XHE account of these volcatioes, extracted from Mr. Hutn. 
boldt's Essay on New Spain, relates to <me of the inogt es^teiisive 
physical changes that the geological records of our globe exhibit. 
In 17^99 ^ mountain of scorias and asb«s, 517 metres (563 
yitrds) above the old level of the neighbouring plains, waii 
Suddenly formed amidst a great number of burning cones, at 
the distance of thirty six leagues from the sea shore, and 
forty-two leagCicfi from any other volcano. The ' plain^ ok 
which this took place, lies between the hills of Aguasarco shd 
the Pacific Ocean, and is elevated from 750 to 800 met. 
(from 8^0' to SSO yards) above the level of the sea. The strnu 
tnits of the adjaceht basaltic hills are crowned with ever-green 
(oaks, wbicTi, intermixed with thei foliage of laurels, olives, and 
dwarf fan palms, afford a singular contrast with the arid plain, 
^hicU has be*h laid waste by the violence of volcanic fires. Ih 
the month of June, 17^9) the inh^bUants were thrown into the 
greatest consternation by a fearful rumbling noise, accompanied 
by frequetit shocks of an earthquake, which succeeded each pther 
at intervals for the space of fifty or sixty days ; after which they 
Entirely ceased. On the 5Sth of the following September a ter- 
tible subterranean noise wa"^ heard, and the frightened Indians 
fled for safbty to the mountains of Aguasarco. , A space of three er 
fi>ot square miles was floated in the form of a bladder, the bouo* 
No. 24.^^ vox. VI. ft 



J is Mr, Humboldt on the Volcanoes of JorutU, 

daries ci which are still visible by the ruptured strata, aild^ ^ 
about 13 yards above the level of the surrounding t>lai!i, while 
toward the summit it gradually increases to the height of l6(X 
met. or 175 yards. They who witnessed the awful scene from 
the top of Aguasarco, assert, that flames issued from the earth 
for the space of more than half a square league^ accompanied 
with fragments of red hot rocks, and clouds of ashes, resembling 
a stormy sea. The crust of th^ earth was seen to s#eH, and the 
two small rivers of Cuitimba aud San Pedro were precipitated 
into the burning crevices. The decomposition of the water reani- 
mated the flames, which were visible at the city of Pascuoso, si- 
tuated on a wide plain 1400 metres above the level of JoruUo. 
A great number of small cones only two or three yards high were 
raised on the dome of the larger elevation, which the Indians call 
•vens.' The beat of these had greatly dinMnished, according \» 
the testimony of the Indjians^ when Mr. II. visited them; but many 
of the crevices emitted ah aqueous vapou** ; and in these the 
thermometer rose to the height of 95^ (if cent. 203° F.) Each 
^cone is a chimney from which a volume of smoke issues ; and in 
•several a subterranean noise was heard, like that of a boiling \u 
quid at no great depth. Though the 'fire appeared to have lost 
much of its activity, and the volcano and surrounding parts were 
hegiuning to be covered with vegetables, Mr. H. found the heat 
of the air very consideraible, as the thermometer in the shade and 
much above the ground, ro^e to 43^ or 109'4* of Fahrenheit. 
The two small rivers which were lost, are supposed to break out 
iigain in two springs from the clayey dome of the furnaces ; the 
therawl waters of which, possess a temperature of 126* SG^ of 
Fahr. The situation of the new volcano af Jorullo, gives rise to 
a curious geological observation ; that the line of volcanic moun- 
tains in Mexico does not coincide with,* bat is perpendicular \o the 
axis of' the great chain of mountains in that country. This new 
volcano was formed in a continuation of this line, which is com- 
prised in a narrow zone, included between IS^ 59^ and 19^ 12^ of 
oorth latitude. Mr. Humboldt's observations on this chain of vol* 
canic mountains induce him to conclude thai there exists a fissure 
At a great depth below the surface of the eaith, extending from east 
to west, through the space of 1^7 leagues^ from which the voica* 
nic fire has made its way at different times, bursting the outer 
, crust of porphyritic rocks, fronpi the coasts of the Mexican g^lf 
to the shores of the Pacific Ocean.- 



-T 



Obiermlknu^'^lht object of geology is to unfold the structure 
of the globe, to discover by what causes its various parts have 
been arranged ; to ascertain, the source from which the immense 
number of different substances of which it is composed have eri* 
^inated 9tnd their general stratification, and the inequalities which 



Mr. Humboldt on the Volcanoes tifJorullo. 1 19 

■xfiversify its surface have arisen. In the pursuit of this investi- 
gation, however, many diflkulties occur. The mere crusl of the 
earth is all to which our knowledge of hts materials can possibly 
extend ; a small portion of this only is inhabitable, and a 
much smalllcr still in a state of civilization ; our experience 
i« therefore very limited. Numerous facts, however, have been 
collected that most tJecisi-vcly prove tbat the general mass has 
undergone various wvolutioTis, tind that these have not only been 
of gieat antiquity, but of universal extent. There is ample proof 
that its whole surface has been covered with the ocean, and that 
e^•ery part of it has suffered a change ; mountains have been 
raised, islands separated from the main land, and the waters col- 
lected so as 10 leave the elevated parts dry. It is difficult to 
cx)nceive canses adequate to the production of such effects ; and 
opco-ations so immense seem far removed from any means of in« 
vestijgAtio^ we possess. Amidst aJl this unceitainty and apparent 
confusion which surrounds us, one fact o! .great importance seems 
to be clear, that the shell ofour jjlobe has at some remote period 
been in a state of fltjidi,ty, and that from this circumstaDce has 
arisen its present arrangement. Now, as we»re only capable of 
conceiving two natural causes competent to products such effects, 
the enqniTy t:onsequenily rests i>etween thjBSe; and the question 
is; ought the present structorre of thB earth to he regarded us the 
^bult of igneous ftisiop, or of aqueous solution ? On this ground 
two distinct theories have arisen, whiclj were r.gitated witb con- 
siderable warmth in former times, but with a still greater degree 
of &rdot:ir, and a clearer view of the sutject, in the present day. 
These two theories have obtained the appellations of the Plutonic 
and Ntpfunian systems ; the latter of which possesses the greater 
mimber of advocates. These, however, cannot deny that the 
opposite system merits the praise of novelty, boldness of concep- 
tion, and an unliniited extent. It aspires, not only to account 
for the present appearances of tire earth, but to trjice a plan by, 
which the formation ot successive worlds is developed : it at- 
tempts to extend that order and arrangement, that principle of 
balance and restoration manifest in ail the vairious departments 
of nature, to the constitution of the globe itself. With this the- 
ory the Neptiinian forms a striking contrast. It presumes not to 
carry its researches beyond the commencement of the present 
world, nor to. extend them bcybna its termination. According to 
this theory, water is the great agent by which the strata on the 
sur&ce of the earth have been both formed and arranged. It does 
not attempt to deny the existence of subterraneous hres t© a cer- 
tain extent, or that man} of the phenomena which strike us most 
forcibly have been the results of such an agency, and the fact 
stated in the present article is a striking instance, but it denies 
tbat the agency of fire is the general cause of the present geolo. 
jzical appearances of our globe, and further ^^ertS; that^fire can« 



120 M. fylaroch on thf Air Madder 0/ Fishct* 

not exist in the interior of the earth, to an extent sufHcient for tli^ 
production of such effects. While we ascribe the general and r^ 
gular arrangement oj the materials which constitute the exterior 
part of tlie, terraqueous globe to the iniluence of an aqueous agent, 
\ye are perstiaded that many of theif frequent disruptions are the 
effects of igiation. The volcanic islets that have 1 isen above the 
ft,urface of the sea, as those near the Azores, in the Archipelago, 
and on the south side of Iceland, as well as the present instance 
and the appearance of the adjacent country, are strong corrobo- 
rating proofs of the truth of this opinion. There is an apparent 
contradiction in the numbers in the early part of this article, for 
\vhich we are unable to account* 



Report made to the French Institute , on a Metfioir of M. Dela^ 
ROCHE, on the Jir Madder of Fishes, Bj^ Messrs, Lafecede, 
. Vauquelin, and Cuvier. 

As several naturalist^ have of late directed their attention to 
the air-bladder of fishes, whi^h is too different from every Qtheic 
organ, not to excite a considerable degj'ee of curiosity relative to 
both its nature and functions ; yet this attention, in these in* 
qifiries, as in many others ip comparative afiatcmiy, has given 
birth to conjecture and hypothesis, when it should have pro* 
duced exact observation and philosophical deduction. As we 
consider the historical part of the paper to be interesting, we 
aball present our readers with the substance pf it in as few word^ 
as possible. 

' Rondekt, in his Hist, Pise, published in 1554, merely observes, 
that the air-bladder exists more constantly in fre&h water ihaii 
in salt water fishes ; and that it probably assisted them in swim- 
ming. Marcus Aurelius Severinu§ thought the air it contained 
was produced with the animal, from which it may be inferred 
that he bad not perceived any outward communication. Walter 
Needham was the first who undertook any more detailed ^inquiries 
on the subject. These he inserted in a work printed in l66S, in 
which they woyld not have been expected ; namely, in his 3ib^ 
^ioth, de Magnet, He adopted the general idea relative to the 
utility of this bladder in swimming, and explained why flat fishes 
did not need it. He described the two tunics 6i this organ, the 
varieties of its form, and the origin of its canal of communica* 
tion. He shews that the vessels are more than requisite for its 
nutrition, and thinks that some organic functions are exercised 
hy them; he also imagines that the blood they contain has 
some connexion with the air. But as it is difHcult for the air to 
penetrate from without in certain fishes, he conceived it to be se- 
creted there, and te proceed thence into the stomach where it 
assists the process of digestion ;. an\i he poij;its out th^ red bodies 



Jf. Dckrockt on the Air-Madder of Fuhes. ISl 

^hicfa perform this secretion in the snake. BortUi explained, in 
1676^ in. his De Mot. AnimaL^ how the air.bladder is used ia 
swimmiogy and observes, that when the air.bl&dders of lishe^ 
bursty they remain a^ the bottom of the water, as well as those 
which are natuȣiUy destitute of it; and Concludes that it is 
designed for jthe purpose of maintaining an equilibrium between 
the specific gravity of the fish and that of the water; thus, by 
either enUrgiag or compressing its contents, it adds to the faci- 
lity of ascending or desct^nding, as occasion may require. He 
supposes that th^ communication between the air.bladder and 
the stomach must afiPurd the means of either varying nv renewing 
the quantity of air which the former contains ; but he has nei-> 
tber described the varieties of its structure, nor determined in 
what fishes it exists. Redi resumed the observations of Need* 
ham in his Observations sur les Anmaux vivam cofUenus dans Us 
Anmaux viva/is^ published at Florence in l6S4. lie adds some de- 
tails respecting such tishes as hav^ no air-bladders ; and the red 
bodies found in the interiyr of these organs. Ue also states his 
having sought in vain for the canal of c3mmunication in certaia 
sea fishes ; but tliought his want of .success was to be attributed 
to the inaccuracy of his observations, Raif and Wilhughby, Hist* 
pise. 1680, disputed the idea of this air being used in the pro- 
cess of digestion, and reduced the functions .of- the .air-bladder 
to its use in swimming, according 10 the noLiuns of Borelli. The. 
same opinion relative 10 this bl&d4er >was also sup[)orted by Fres-^ 
fOHf in the 19th volume of the Philosophical Transactions; by 
Ptrraulty in his Mccanique des Animaux^ published in 1721 ; and 
by FetU^ in the Memoirs dc VAcademie for 1733. . Perrault, bow. 

, ever, made the important observation, that there are fishes with. 
out any canal^ and that it is in these that tiie red bodies are 
found which are intended for Uie separation of the. air. He like- 
wise adds, that in those whic)i have a canal, tjie air, when com- 
pressed, dcfcs not issue from the bladder : a remark too much 
generalized. Petit, in opposition to this, thought be had disco- 
vered valvuU in the canal of the carp, which admit the air to 
escape, but not to return, Notwithstan^iing PerrauU's pbserva-' 

. tions, Artedit in his Partes Pise, 1738, still ascribed to all air- 
Madders a carial intended for the introduction of air ; hut there is 
no opinion given, respecting their use^ except that by Borelli. 
GouoHy Bhckj and some other authors who have written upon 
the subject add nothmg essential to the details that had previ. 
ously been given. Besides this principal use of the air bladder 
in fishes, some have supposed that it had others which are of an 
accessary naiu.re« Of this opinion was Vitq d*Azyr^ who, in his 
Memoirts PresejU/Sy 177 ^x supposed that the air originates in the 
stomach, and, charged with nutritive particles, thence proceeds 
)Bto the air*. bladder, in order to be absorbed by the vascular &yf>' 
Vfim* Neafl^ the same is the opinion oi Brouumnct^ in Van Posit* 



i22 M. Ddaroche on the Air Madder of fishes, 

circ, Reii>ir,y while Erxlcbpn, in a tnenioir on the subject, printed 
in 177^, is of tlie same opinion relative to the production of the 
air, but coincides with the common notion with respect to its 
nses. , These tliree anatomists, however, do not seem to ha^v^ 
known, that the communication btstween the stomach and the 
air-bladder is frequently wanting. This circumstance is strongly 
insisted upon by Kochlreutcr, in his Nov. Comm, Pdropaht. 1775, 
Having ascertained this, and described the organization of the 
red bodies, he maintained that thft air is separated from the 
blood in the bladder, but he seems to have been unacquainted wiih 
the works of P^rrault and Keedham. Lrskr^ in his Nat, Hid. 
adopted the opinion of Koehlrcuter. Monro, in his work nn 
fishes, has added but little of importance to wliat was previa:' /': 
known on the subject. He made the same distinctiofi with " ;- 
rault, relative to the secretory bodies, and re?niv:;^-t :, ^ \\ ^ 
genus anguilla was an exception to the rule, fi ;• " . '.-.■_ r v. 
the canal and red bodies. Mr, Fischer^ now proie '" r .^^s 
cow, published a dissertation on the suLj'ct, in 1793, :.» vi; . !< 
after noticing the writings of bis predecessors, ai^d gv nc, } ^- 
own experiments on the tench and carp, states it as his Oj.ir!: r-^ 
that besides its ust in swimming, the air-bladder is also a -i.p- 
plenientary organ of respiration ; and destined to absorb tl"? <>xv» 
gen from the atraotpheric air in water, in the same manner as *ie 
supposed the giils to ^l^sorb the oxygen of the water itself by 
decomposing it.. A/, dc Lapecede thinks that the air-bladder of 
certain fishes may be filled with Ih^ gasses resulting from the 
decompositions whieh their respiration occasions ; and mentions 
his having collected hydrogen gas from the air-bladder of 
tencl.es. AL Davermn/y editor of that part of Cuvier's compara- 
tive anatomy relating to the air*bladder of fishes^ adopted, in 
common with M, Cuvier, the opinion of Needham and Koelilreiiter, 
respecting the production of the air in the bladder by secretion. 
He thinks, from the absence of the air-bladder in many sorts of 
fishes, that its functions cannot be very essential to life ; and 
concludes from various comparisons, that it is an organ inti- 
mately connected with loco-motion. He also expresses his sur- 
prise at the discordance obtained from different analysises of the 
air contained in the bladder: Mr. Fourcroy and others having 
obtained little besides azote; M. Configliali obtained 40*0 of 
oxygen ; while others, like Mr. Broadbelt, found the quantity to 
be variable according to circumstances. M. D. concludes by 
suggesting the necessity of philosophers inquiring into the limits 
of these variations with a view of deciding a great number of dis* 
puted questions ; and Messrs. Gceffroy, Vaiiqueliny and Hiot have 
recently made a great number of experiments of this nature. 
Mr. Blot found that the air contained in the bladders of several 
fishes of the Mediterranean varies from pure azote to 87*0 of 
o«cygen, with very little carbonic arid, and without fkoy by4FO« 



Mi Delarocke on the Air-bladder of Fishes. IfS 

gen; he also, in general, found Ibat the quantity of oxygen waf 
greater in proportion to that of the hydrogen as the iish was 
caught at a greater depth. He hkewise remiirked that when fishes 
weie suddenly drawn up from considerablp depth, the air-bladder 
ceasing to be compresbed by the column of water abote, became 
greatly extended ; sometimes so much sn as to be ejected from 
the mouth. The experiments of Messrs. Gcoffroy and Vau« 
quelin published by Biot, tend to the confirmation of his own, 
and agree witli others previously obtained by Fourcroy, who had 
found ahnost pure a2ote in the bladder of the carp ; and also with 
those of Humboldt on the bladder of the gymnotits electiicus, 
which 'consisted of i^6'0 of azote and 40*0 of oxygen. 

This is the substance of the whole knowledge that had been 
acquired On this subject prior to the reading of M. Delaroche's 
memoir to the French Institute. But in order to guide themselves 
iu forming a correct opinion, of his theory, these reporters have 
noticed two memoirs on the same subject since M. Delarocbe's 
was read. One ot' these is by M. Geoffroy, who refers to a 
former memoir in which he has developed anatomically the 
means by which fishes compress^ or dilate their air-bladders in 
order to descend or ascend; and on this subject he is of the sam« 
opinion as Borelli, which is the commonly received opinion. The 
other of these memoirs is by Messrs. Huniboldt and Proven9al, on 
the respiration of fishes. They found the air in the bladders of 
river fishes to vary from QpO.to 87*0 of azote; and have even 
observed as much as 5*0 of carbonic acid. They caused some 
tench to respire hydrogen, yet their air-bladders did not contain 
any of this gas ; but when they respired oxygen, the proportion of 
that substance in the bladder was somewhat increased. They 
also determined that when fishes were deprived of the air-bladder, 
they were still able to raise themselves in the water, though they 
gen«*rally remained at the bottom. 

'^ Thus, in the numerous works we have analysed, almost every 
possible hypothesis has been proposed, attacked, or defended, and 
examples have been given of almost all the combinations of 
organization that could be devised. M. Delaroche had therefore 
only to examine these organizations a little further, in order to 
reduce them to general rules, and to weigh over again the 
arguments advanced for or against every hypothesis.'' It is 
an examination of this performance that constitutes the re* 
maining part of the present report. His residence at Iirica, 
Formentero, and on the coaist of Spain, had furnished him 
with opportunities of examining several kinds of fishes which are 
only to be found in the Mediterranean sea, and he has given nearly 
fifty particular descriptions of the air-bladder of different species, 
sooie of which had not been previously described. He treats 
successively on the anatomical structure of the air bladder^ the 



1 24 JMTv Delaroeke on the Air-bladder of Fuhei. 

soorces of the air which it contains, and the functions whi9h i( 
exercises. He likewise gives a list of those fishes that have it/ 
and of those in which^ it is wanting. " What he says on Xht 
suhject of the canal of communication also presents a great 
nunEiber of novelties. On this head he has madc'sonie very acute 
remarks, and has ascertained that this canal is wanting in the 
greater part of sea fishes. He did not find it in many of the 
jugular or thoiacic classes, which compose nearly three fourth* 
of the total species of the fishes with which we are acquainted." 
M. Delaroche has particularly studied the red bodies with which 
tfee air-bladders of certain fishes aref furnished, and has gives a mi- 
nute description of them in scveial kinds. The authors of this 
report state that they have verified his descriptions as far. as 
opportunities had offered, and that they had generally found them* 
Correct. And though they difler in opinion from the autiiOr of 
these researches, in some respects, and adhere more strictly tor 
the opinion of Borelli respecting the use of the air-bladder, yet 
they think this memoir is worthy of the approbation of the class ; 
and from the great number of new and correct observations it 
contains, respecting the anatomical, structure of the air-bladder 
and the sources of the air, they recommend it to be published 
among the memoirs of Savons Et rangers. 

» 

Observations, — If we consider the vast extent of that depart- 
ment of natural history which is denominated Ickthyolorry, we 
shall readily be convinced that there is no one branch ojf this kind • 
of knowledge with which mankind iji all ages have shown thenri<A 
selves so little acquainted. This, however, will not be matter 
. of surprise when we reflect that the subjects of which it treats' 
exist in an element so different from our own, and at such depths 
that there is reason to suppose gr^at numbers of entire genera 
have never yet either been forced by accident, or dfagged by htb» 
man skill from their natural abodes and brought within the pale, 
of scientific examination. Though, in an uncivilized state of so- 
ciety, fishes constitute a considerable part of human subsistence; 
yet those resorted to are both few in number, and such as are 
most easy to be obtained. Even many ages must' be SHffered Id 
dapse, and nations most have advanced far in th6 paths of know- 
ledge before they extend their inquiries beyond the confines of 
ichthyology, or obtain any considerable acquaintance with the 
inhabitants of the ocean. In the unfathonied depths of that tur- 
bulent and extensive clement, it is not improbable that million* 
reside, which are secluded from human observation, and even of 
the few which the'industry of man has at last drawn from their 
hidden abode, little more is known respecting them than ttieir 
external figure and names. Their foo8, their longevity^ their me*- 
tbpd of propagtting their kindy and the wbok of their mannerr 



itain and Meteorological Tableh 1 45 

ind ccoflomy, remain still among those numberless secrets of 
nature,* \Vhich the ingenuity of man has hitherto been unable to 
f xplore^ The natural history of iishes has therefore seldom been 
ifound interesting, because destitute of that information which it 
is the province of history to convey: and ic will not be hazarding 
too much to assert that it will ever remain more imperfect and 
obscure tban that of quadrupeds and birds^ in proportion as the 
fclement which fishes inhabit is more inaccessible to the cu- 
riosity, and impervious to the researches of .man. On this ac- 
count all inquiries that have a tendency to illustrate this, difficult 
part of natural history ought to be received with candour and 
attention, and valued not only in proportion to their success, bu( 
also to the difficulty of conducting them. 

Among the various organs which constitute the aniiiial econo« 
.my, and perform the functions necessary to the existence of active 
liie, there are some respecting the use of which physiologists 
differ in opinion: of this kind is the air bladder in fishes. This 
sipgular organ^ which belongs only to this class of animals, and 
is not found- in all the species, exhibits so many varieties, as upoa 
a slight if^spection of its general appearance it does dot seem to 
perform the same functions in each individual. In some fishes 
it has a communication with the stomachy in others it id destitute 
of this, and is furnished with bodies of a peculiar nature, of a red 
colour and iamellated structure. There are also some bladders 
that have both these red b()dies.and the canal of communication ; 
and a few are supplied with peculiar muscles, i As the object of 
Mr. Delaroche's labours was to inquire into the nature and uses 
of this singular organ, and the inquiry appears to have been cqn- 
ciucted with greiit ingenuity and ptr^everance, we doubt not that 
his memoir will be perused by the iciiihyological physiologist with 
considerable interest. But as we wished rather to present our 
readers with the brief historical sketch comprised in this article 
than to enter into any particulars on the subject, we must close 
these general remarks, by ol^serving that the observations conr 
. tained iu this report possess marks of that acuteness which has 
already obtained Mr. Cuvier 6uch a degree of celebrity as a na- 
turalist. 



Table of Rainy that fell at various placeB in the y^ar I809> l>y ^^^ 
Jl«?. J. BLANCHAtiD, of Nottingham ; with a Meteorological 
Table for the same year^ by Dr. Clarke, of that Town* — FhU» 
J&um, No. 114. 

O^ the eleven places mentioned in this table, given by Mr. 
Blanchard, the greatest annual quantity of rain fell at Dalton in 
Lancashire, and is stated at &b'Z6 inches. The least quai;itity 

No. 24.-— VOL. VI, s ' 



It6 Rain and Meteorological Tables. 

was at W«st Bridgford, in Noltinghamshire, and was 17*55^ 
incbes. The greatest monthly quantity at Chichester and Chats- 
worth was HI January; at tho former it was 8*44, and at the 
latter 5*22 inches. At Chichester there was no^ie in March; 
and at Chatsworlh the least quantity fell in October, and was 
0-28: the total at the two places being 38 07 and 29'9l inches. 
At London the greatest and least quantities were in July and' 
October; ibe former wag 3.38 and the latter 0*22 : the annual 
quantity was 24*95. The greatest quantities at Horncastle, 
Ferriby, near Kingston-upon-llirH, ^^€alh, near Wakefield, York- 
shire, Lancaster, Dalton^ Bridgford, and Nottingham, fell in 
August; and were respectively 4*53, 5*88, 4-6l, (>*12, 7*25, 375, 
and 4*50. The least quantities at the following places were, at 
Horacastle, in October, 0*75 inches ; at Ferriby, in May, 0*45 ; 
Heath, Manchester, Lancaster, and Dahon, in March, and 0*43, 
0*35, 0*55, and !• 13, respectively; Nottingham, October, 0*31. 
The total quantities were, at Horncastle, 28*38; Ferriby, 27,^7 ; 
Heath, 31*65; Manchester, 29*10; Lancaster, 41*73; Notting- 
ham, 2301. 

Ill Dr. Clarke's meteorological table it is stated that the highest 

observation of the Th^rmoftieter wa« on the 27th of July, and was 

78% wind S. The lowest was en January 22nd, 17% wind N. at 

2 miles distant from the town, it was 14** on the same day. The 

greatest variation in the space of 24 hours, was 18**, June 1st — 

Snd; and the mean annual height 48*''78. The greatest height 

of the Baromettr was June 25lh, 30*45 inchei, wind N. E. 

Lowest, December 17th, 28*25, wind W. Greatest variation 

in 24 boars, January 30th— 31 st, 1-13 inches; and the mean 

annual height 29*74. Dr. C. al-so states that the wind was m 

the N. and N. E. 130 times; E. and SE. 79; S. SW. 197; 

and W. and NW. l65 times in the course of the year. The 

number of fair days >^as 234, and of rainy ones 131. On the-' 

19th of Aprily snow fell to the depth of a foot. 

Obseriatiwfs,'^ At page 350 of our 5th volume, we noticed two 
aimilar tabled by these gentlemen-; and we hope that in future we 
shall have similar tasks to perform. By comparing the twa 
abstracts, it will be seen that the greatest monthly fall of rain in' 
tlie former year was chiefly in October, in the latter, in August: 
aliso, that the total quantities which fell at all the places in lft09» 
considerably exceed those which fell at the same places in the 
preceding year, except at We»t Bridgford; and the observatirtns 
there appear to be incomplete, as the columns for Febxuary and 
May are suppliedv with dashes instead of ^gures, whereas that 
of Chichester for March, where there seems not to have hetst 
any, is occupied by ciphers. There is likewise a considerable 
di^rence between Uie greatest heights of the thermometer, for 



Mr. Williams on Ax'iMtdhal Refraction, \^ 

fine tjjro years, it being 11°. Tbe greatest height of the tbcrmo- 
met-r at Loudon was on the 25th of July, and is stated at 77°; 
but as this observation was made at noon, it is probable that it 
was higher a little later. It is also remarkable that the least 
height or the thermometer at Nottingham, should not only hap- 
4)en on the same day, but be exactly the sante degree, in each 
year. May not this lia-ve been a mistake in, copying? The least 
jheight at noon at London was on the 18lh of January, and was 
26 . There is likewise a difference of 1*06° in the annual meaa 
of the two years. Tbe greatest height of the barometer at Lon. 
don was on the 22ad of July, when it attained to 30*6; and the 
other extreme happened on the same day as ^at Nottmgham« 
when it siink to 28' 3. 

On Azimuthal Refaction, By Mr. Charlss Williams, — Phd* 

Mug. No, 144. 

Os the 28 ih of last February, as Mr. Williams was crossing 
jsome higii fields to the suutb of Primiose Hill, about nine A. M. 
he observed several objects assume a distorted appearance, and 
that the spire of Ibliiigton Church appeared crooked, and in a 
few minutes aftcrwaids about 20 feet of the upper part of it 
.seemed to be separated from tbe rest, and removed to .the right 
Land of it. Mr. W. therefore screwed his tdescopc into an 
adjoining post, but before\he couU adjust it, the Aspire becatne 
indistinct, being wholly envelope^ in the fog. Hfi then dii;ectecl 
the telescope to Hampstea^, the tipper part of which was' visible, 
but a thick fog rested on the bottona of the hill. Having obtained 
a good in^ers.t^tiou, and found the telescope to remain quite 
steady on account of the calmness of the day, he soon observed 
the tower to iecrease in height, and shortly after the upper pari 
appeared separated from tl\e lower, when the latter seemed to 
retire to th]^ left, but the former remained stationary with respect 
to azimuth, but increase^ in altitude; in three or four minutes 
the top was considerably elevated, and appeared as if rising into 
a cloud. The bottom part was about one sixth part of the whole 
diameter of the tower to the left, became hazy, and in that 
situation it disappeared. I'he telescope remained stationary till 
the* tower again became visible, when the two parts appeared to 
be joined, and in nearly the same situation in which the iower part 
was last seen, and continued so till the telescope! was removed* 

Mr. Williams also adds^ that a gentleman stated, that in the 
^course of the same day, ^* one end of a row of houses near Holr 
loway appeared to him at first much higher and afterwards 
much lower than the other, although he did not change his situa- 
tion:— and another, that the top of Primrose Hill, with some 
p£fsous on it, appeared to him separated from t)ie bottom and 



12? Mr. Jfdiiams an Azimuthal Refraction. 

floating in the air, and that he bdd seen a simiiar eflfect on othe)[ 
liills several times before." 



Observations, •'^That the lower part of the atmosphere is 
subject to several variations which are not nisily accounted for, 
has long been known to philosophers. A sudden change in it* 

' temperature, density, or other circumstances may effect changes 
in its refractive powers, and render them liable to great uncer- 
tainty. The cause of this uncertainty, however, appears to be the 
great quantity of vapours, and exhalations of various kinds, which 
are suspended in the air near the eirth's surface, and the different 
yariations to which these are constantly subject. That this is 

'the case seems evident both from the present in^tnnce and 
several others that have been previously recorded. As some of 
these are highly curious circumstances, and. perhaps not very 

^familiar to many of our readers, we shall give a brief account of 
tbe principal; with the respective states 6f the atmosphere at the 
time, as far as was observed, as it is from a combined collection 
of both these kinds of observations that the cause^(>f unusual ap- 
pearances arising from refraction is most likely to be determined. 
M. Picard found that refraction was greater in winter than in 
isummer, and in the night than in the day. He also observed; 
that during the time that the upp(*r limb of the sun appeared in 
the horizon until its lower limb came into the same situation, 
the refraction- had diminished 25''^. Bouguer also observed in Ame- 
rica, that the refraction was greater in the night than irt the tlay 
by about l-6th or l-7th. Dr. Kettkton measured the altitude 
of a hill on a clear day, and repeated the same observations when 
the day was cloudy and the air gross, and found the angle in the 
latter case to be considerably greater. He likewise observed, thiat 

.. the altitudes of some hills which he measured appeared to be 
greater in the morning before sun rise and late in the evening, 
than at noon in a clear day. M, Monnifr observed at Paris, 
during the great frost in 1740, that, when the thermometer was 
10° below the freezing point, the refraction was 10' 15'''^, at an 
elevation of 4° 44:|'; but when the thermometer istood at 24** 
above the freezing point, the refract on at the same altitude was 
reduced to ^^ 20^'', consequently there was a difference of H 55^ 
for a change of 34° of the thermometer ; the mercury in the 
barometer stood at the same altitude at the time of both ob- 
servations. ' 
The variation and uncertainty of the dip of the horizon in 
different states of the air, taken at the same altitude above the 
level of the sea, induced Captain Huddart to make- observations 
on horizontal refraction. In%the course of these h^ often observeid 
that low lands and the extremity of head knds^or points, forming 
an acute angle with the level of the sea, and viewed from B 
distance beyond it^ appeared to be elevated aboy^ the sea with c^ 



i 



Mr, WUUttmson Azimutkal RefracHon" 129 

9pen space between the land and the water. He states, that the 
(nost remarkable appearance of this kind which he witnessed 
was* at Macao, where, lor several days previous to a typhoon, the 
points, of the islands and the low land appeared higher, and 
the spaces between them and the sea greater than any other he, 
had seen. This he thinks, arises from, and is proportional t<^ 
the evaporation going on at the surface of the sea ; and that this 
evaporation causes the maximum density of the atmosphere to be 
at some distance above the surface of the earth, from which alti^ 
^ude it decreases both ways. He states some other observations 
which tend to the confirmationof this theory., in the year 1793f 
when residing at AUenby in Cumberland, Mr. Huddart made 
some observations on the Al^bey Head in Calloway, about seven 
kagues distant, and the window from which the observations were 
made, was about fifty feet above the level of the sea at that time 
of the tide. There was a dry sand between Mr. il. and the head 
land, at the distance of aoout thr^e or four miles from his sitna* 
tion, over which the horizon of the sea was seen ; and this sand 
was then about three or four feet above the level of the water. 
The sharp point of the head. land appeared blunted and elevated 
above the sea, and a part of it entirely insulated, and considerably, 
raised above the watej \^ith an open space between them. A part 
of the Abbey Head ako frequently appears to be fTeparated from the 
rest of the land at a much greater distance from the shore than 
in the present instance.' This observation was made ip the after- 
noon, and when the intermediate sand contained very little mois* 
ture. At another time when the land app<-ared elevated, Mr. H*. 
/directed his t( lescope to a small vessel about eight milts distant, 
which appeared to be elevated c^bove tbe w^ter, and iq have an in- 
verted image below it, the mast of which seemed to penetrate the 
surface of the sea. In this observation the telescope was about 
forty feet above the level of the sea, and the mast of the vessel 
about thirty-five feet. The barometer was at 29'7 iaches, and 
the thermometer 54°. Some other appearances of head lauds, 
and the circumsta^nce of the Portland lights appearing much 
brighter when they are seen near ibe horizon of the sea, are 
stated by Mr. H. in the Philosoohical Transactions for 1797. 

Other appearances also of a different nature from ihese de- 
scribed by Mr. Huddart, are son^etimes found to take place; and 
^he Rev, S. Vince, of Cambridge, had an opportunity of observing 
several of these at Ramsgate, on the Jst «)f>AHgust, 1788, be- 
tween half^ past four in the afternoon and seven in the evening. 
1 he day had been very hot, and the evening was sultry, and the 
^ky clear, except a lew /lying clouds. These pbenomeni^ were 
observed with a telescope, which magnifies between 30 and 40 
^imes, but they \\.ere visible to the naked e^^e. The height above 
fyp level of th^ sea, at w))ich most of the observations werema4^ 



J 30 Mr. Williams on AzinuUhcd Refraction^ 

was about 25 feet ; some of them, however, were made at ^n ei^f 
valion of 80 feet ; but it did not appear that the phenaR»ena were . 
altered by varying the height at which they were observed, flav* 
ing directed the tele&cope at random, with a design of examining 
any objects that might be within the field of view, Mr. V. saw 
the top of a ship's mastfe above the horizon of the seh, and • t-r- 
tically over this vessel, two complete images of the ship v'ith 
their hulls joined, were distinctly visible in the air. The upper 
one of these was erect, and the lower inverted. 'I'^-is appearance 
was so Strang* and unexpected, that he desired a person present 
to look through the telescope and dpscrib* what he suw ; h)> de^ 
scriplion exactly corresponded with what Mr. V. had himself ob- 
served. As the ship receded from the shore, le*^ and less of ^he 
masts became visible, and the images ascended ; but a^ the ship 
did not descend wholly below the hori^^on, he had not an oppor- 
tunity of observing, at what timt and in what manner, the 
images would have vanished. Being deirou? to observe w!ietht»r oi 
iiot tlie same effect was thus produced on other ships at the sduid 
time, Mr. V. directed his telescope to another ship, the huil of 
which was just in the horizon, and beheld a compUte inverted 
image, the main mast of which just touched that of the ship it- 
self. This ship continuing to move on the horiaon, the image 
moved with it without variation. The next ship which was ob- 
served, was so far beyond the horizon, as jnst to prevent her hull 
from being seen, and only a part of the inverted image was seci^ 
abuve it. As the ship descended below the horizon, more of th^ 
image gradually appeared, till at last they separated from each 
other, but no second image was observed as in the first instance, 
when the ship ceased to descend. Another ship \vas also ob^ 
served with its masts just above the horizon, and two well defined 
images appeared above it, as in the first case, but with this dif* 
Terence, that they seemed to be separated at the same time and 
the sfea was distinctly visible between them. As the ship ap- 
proached the horizon, the erect image gradually disappeared, and 
at last vanished ; the image of the sea also vanished afterwards, 
and the inverted image of the vessel continued to descend^ but the 
ship did not approach sufficiently near the horizon to bring the 
extremities of their luasts into apparent contact. The clifis at 
Calais being visible at the time, the professor next directed his te- 
lescope to them, to ascertain if there was any thing peculiar in 
their appearance, when he perceived a'distinct image of the clifis 
above the cliffs themselves, with an image of the sea separating 
them. These images vanished for a short time, but they soon , 
loecame visible again, and assumed exactly the same appearance 
as before, but soon after vanished altogether. A ship with its 
hull beMw the horizon passing these clifis, exhibited an inverted 
image against their surface. Some time after, two partial ele^ 



Mr, Williams oh AztmMal Refraction. 131 

vaiions of the sea were observed in front of these cliifs ; these 
were equally distinct in every part, changed their figure a little, 
ind vanished in the place where ihey were first seen. 

About this time a thick fog came on the, horizon, from the 
other side, rolling with great velocity, curling as it went, like vo- 
lumes of smoke from a chimney. Mr. Vincc, therefore concludes, 
that, at the time of his observations, there was a considerable fog 
on the other side of the horizon. He also observed several partial 
elevations of the sea which moved parallel to the horizon with 
great velocity. From this circumstance he remarks j " 1 conjee^ 
ture therefore, that these appearances were,' in part at leas^v 
caused by the fog on the other side of the horizon. For though 
] did noiy at the same time, see the motion of thes6 images, and 
that of the fog, yet fjom memory I judged the motions to be 
equal : and they were also in the same direction. A fog, which 
by producing an unusual refraction, might form 4JKe66 iniag^^ 
would, by its motion, produce a corresponding motion of ' these 
images." Professor Vince likewise remarks, that there was not 
any' log on the near side of the apparent Ijorizon, nor did the ships 
exhibit Hoy particular appearance. The common refraction at the 
time, appears to have been unusually great ; for the cliffs at Ca. 
lais could be seen from the edges of the water considerably ele- 
vated abt)ve the. horizon, though they freqitently cannot be per- 
ceived in clear weather Irom the highlands in the neighbourhood. 
The French coast also appeared to a much greater distance tharf 
Usual, and particularly towards the east, where the unusual refrac- 
tion was the strongest. J\Ir. V. examined all ships in sight, daily 
for about five weeks afterwards, but did not perceive any similar 
appearances. On the 17th of August, about half an hour after 
three in the afternoon, however, he observed a ship with an in- 
verted image below it, similar to that observed by Mr. lluddart ; 
but their hulls were separated by an image of the sea. At the 
time of this appearance the ship was approaching towards the 
horizon, and as it advanced, the image gradually diminished, and 
totally vanished when the vessel had attained that limit. These 
tffects Mr. Viuce ascribes to a variation in the refractive power 
of the air, and illustrates his explanation by a diagram, for both 
which however, we must refer our curious readers to the Philoso- 
phical Transactions for 1799* 

We shall now conclude thes^ observations with remarking, that, 
from the circumstances attending these appearances, it is evident; 
that. they all took place at tin;>es when the coi^mon atmospherical 
refraction was much greater than it is in general, and that the 
suspension of vapoui in the air was either wholly or in great part 
the cause. Such a concurrence of circumstances, however, seems 
to be necessary to their production, as does not pften happen at 
the ^xnt time and in the same place. There cannot be the least 



132 Dr. Bosfock and Mr, Foster on ^tetcorolo^y. 

doubt, that vertical refraction is subject to considerable vafiatioif 
near the horizon, according to different states of the atmosphere i 
and as these variations may exist under such circumstances ^s t<y 
produce images both erect and inverted, and both above and be- 
low the real object ; we think it is not difficult to conceive sucfcf 
ji horizontal variatioh in the refractive power of the air, as in 
combination with the vertical variation, would produce the ap- 
pearances observT'd by both Mr. Williams ofi the spire of Isling- 
ton Church, and the tower att Hampstead, and by Mr. Huddart 
on the Abbey Head, in Galloway. As it would evidently be of 
great importance in many ca^es to ascertain the nature of a ship,' 
Avhile the top of her nmsts only are visible, we think that the ex-« 
amrnation of vessels at this time of their appearance, is a sub- 
ject which demands the attention of naval commanders. 



■tassssssa^dBaBBBsI 



1. Remai '. ^ upon Mtteorohay : with a specimen of a new Mefeordlo' 
gical laUc, B^ ^* Bostock, M,D, — Phil, Journ, Aos, 11,3 
and lid. 

t. Ranarks on Meteorohgy, By Tpioma? Foster, Esq.^-^ibid* 

Nu. 1 14. 

i. Dr. Rostock remarks that predictive Meteorology is thsii 
toart of the science which is of the greatest importance, botn fromf 
Its connexion with the great operations of nature and its practi- 
cal utility. This part ot the subject he thinks must be founded 
iipon observation ; and notwithstanding it has engaged the attend 
tion of many philosophers for a considerable time past, and se* 
-veral meteorological tables have been published in different partd 
6f the world; the benefit resulting from th^se, has not been equi- 
valent to the trouble ol their formation. He also remarks, that a 
greater degree of this practical knowledge has beeft attained by 
men accustomed to be much in the open air without the aid of 
science, than all the roles of philosophers hdve yet b6en able to 
impart : but the knowledge thus acquired is unfortunately almost 
^Iways confined to the individual who possesses it ; on account of 
his inability to communicate to others the reasons by which his 
own judgments have been formed. Dr. B., however, is of opi- 
^hion, that these two modes of obtaining meteorological knowledgij 
may be combined, and this is the object which he has endeavoured 
to obtain. To this purpose he observes ; " although my mode of 
life, as a resitJent in the midst of a large town (lAvefpooU) had 
been unfavourable to such pursuits, yet I think that I Irave not 
been altogether unsuccessful m my attempt; some points of kn-' 

Jortance 1 consider myself as having ascertained, and many more 
ave suggested themselves, which a longer series of observation* 
must coAfirtn or refute. My plan of observdtion; as it appearsf. 



Br. ^Bostock and IStr. tost^ on Mdeorotog^. 133 

^sHitially consists, first, in ^ayiog a constant attention to atmo- 
^hericai phenomena of al) kinds ; and secondly, in adopting a 
nomenclature, by which these phenon>ena may be accurately 
T-ecorded, and by which the observHtions* made at different tim<es, 
tind at different places, may be compared together/' The meteo- 
rological joiirnajs which have hitherto been published, he consi* 
'^ers as inadequate to this purpose; as what they contain, though 
necessary to be tnown, are by no means tbe most important 
object^ of a\teuti(iii. V.'liat l)r. B. considers "as such, are 
^ist, the nature and thape of the clouds, and the progressive 
cTianges which tliey are ujid^rgnibg ; secondly, the relative state 
of the barometer, whether rising or falling, and with what degree 
^f rapidity ; and thirdly, the relative stat« of tlie windi whetllci 
increasing or idiihinishing, whether it has lately changed Us direc- 
tion, aiid from whiit point it pi«oeeeded before its .clmnge. Th6se 
Arc th^ o4)ject8 to which the attiention should be uniformly di- 
j^ected, and whi^h mav l>e c()hsidered as the basb of all nieteoro^ 
k)gical predictions. Tliere are also a number of accessary. cir« 
•cuoifitaiices that may be occasionally employed. Of th<^» 
ibme 6f tlie tnust important are, tiny sudden or t^markable 
changes ki the temperature or humidit)' of Clie atmosplvere; the 
ilspect of hioiintainA br i>iher distadt objects ; .the appearance of 
(be hbrison as contrasted with the higher regions of the atmo^ 
sphere t tlie «tate df the bir as to fogs, mists, dew, ha^e, $;c. ; 
the electric Mate of tbe air; the manner in which smoke is 
]|ffected in passing from ^ chimney tops; and the state of evapora- 
iion Trom tbe siii-fac^ of the earth." - . . > 

These remarks are followed by a specimen of his diary fur 
Septtmher^ 1809* Of this we shall transcribe the first three day9 
as an example of bis ifiethod, and then give his own explanation 
#f the diary Of which they form a part. 



^* SiPTEMBEli, ISO9. 

J. iE 2572-;-Partially clear, some light (blonds, nearly 



t 

SE 
2 



calm. Continued all day nearly clear and 

29'fia — calm with a gen tie breeze. Evening clearand 
calm; a very pleasant day. Mountains 
clear, but hgbt. No tufts or lines, but 
a few small rouiid, dark clouds; afternoon 
transparient. 

• • 

SE 29 'Co— Uniformly cloudy, gentle breeisc^ After- 
3 wards some break«t, the brcere increased. 

At noon some rain came on for 2 hours. 
Afternoon cleared partially, and wind 
went to E* '1 hen some h«avy brpiea 
'1 3^0. 2-1- — Vol. vi. t 






3. 



E 
6 

E 
5 



E 
3 



^4. Dr. Bostock and Mr. Foster (mMtteorotogf, 

29*50«-CIoud8, and ai| imperfect arc between S 
and W. Evening wind high, partially- 
clear, driving showers in the night. . 

^9'48 Fresk breeze, heavy clouds, tendency to 
rain. Forenoon more clear and less 
windy. Afternoon a heavy shower, then: 
partially clear, and a gentle breeze. 

29'^0 Evening some lightning. I'he state of 
tbf atmnsphere, which produced the 
squall of the 2d, now changed, but 
wind still £. 

This diary consists of two columns, the first for the direction 
aid force of the wind, the second for the height of the barometer, 
and to tliese is appended a large space for occasional remarks. 
For the direction of the wind, I think it sufficiently minute to 
divide the compass into l6 points; N, NNE^ N£, ENE, £, 5cc. 
for the otlier quarters. The fo^ce of the wind is comprehended 
under 8 general terms, which have each their appropriate figure. 
1, calm ; 2, nearly calm ; 3, gentle breeze ; 4, breeze ; 5, fresh 
breeze ; £, windy ; 7» high wind ; 8, violent storm. There are 
some other circumstances connected with the wind, whether the 
force be uniform or whether it be irregular, what is usually called 
squally, whether it be increasing or diminishing at . tbe time of 
observation, whether it blow steadily from one point or veer 
about; whether it shift irregularly or revolve gradually, and 
lastly, whether it appear to extend high into the atmosphere^ 
or only affect the lower stratum/' 

Dr. B.'s next object^n tkt» communication is to explain suck 
terms of his nomenclature as occur in his occasional remiirks* 
The height of the barometer is taken between ei^ht and nine ia 
the morning, and at the same hour in the evening ; but its abso^ 
lute height he (Considers of much less importance, unless it be 
known whether it be rising or fatling at the time of observation. 
The phenomena of the clouds constitute a principal part of Dr. 
B/s system, and a variety of terms are employed to designate 
their, general shape, size, colour, density, height, motion and^ 
cither particulars. Besides these, it' sheuld be observed whether 
their magnitude be increasing or diminishing: whether any 
change be taking place in their distinctive characters, and whe*> 
ther one species of cloud be gradually changing into another; 
and what is their respective relations to the state and directio|i 
ofthewilid. By a transparent oKmoiphere, as mentioned in' the 
riemarks on the first of September in the above specimen of the 
diary, is tb be understood a state 4n which moderately distant 
o1>jects assume a peculiarly beautiful appearance : and this state 
ke illustrates by saying it is like a'picture very highly varaisbtd.* 



Dr. Bostock and Air, Foster on Meteorolo^, 13$ 

iThis transparency seldom lasts more that a few hours, and gene- 
rally takes place before the sun sets, which is frequently atcomf 
panied with the most brilliant colours. This transparent state^ 
Dr* B. regards as one of the most infallible signs of rain : this 
took place in the instance referred to. The particular formation 
of clouds, which is denominated an arcy September 2nd, consists 
of a body of clouds extending in nearly parallel lines through a 
considerable portion* of the visible atmosphere, and converging 
towards a point near the horizon. Tbese lines sometimes ter- 
minate in a similar manner at opposite points of tiie horizon, 
and at others they do not extend beyond the zenith. If this arc 
be composed of parallel lines it is termed a iviear arc ; when it 
consists of rows of small clouds, a mottled arc ; when resembling 
a volume of smoke rising from a chimney, a wreathed arc ; and 
when it has the appearance of feathers, a feathered arc. Indepen- 
dant of any particular shape, it may be either perfect or imper- 
fect, and either increasing or diminishing ; forming a precipitating 
or dissolving arc. It also receives the denptrii nation of Hprment, 
past, or future arc, as it coincides with these different states of the 
wind. A present arc always indicates that the wind will soon 
change from the point which forms its present direction, and 
when it arises from a S* or W« quarter, it will generally proceed 
to the right or left hand, as the barometer is rising or falling at 
the time ; the observer being supposed to face the point of th« 
horizon from which the arc proceeds. When a future arc is 
formed on the left hand of the wind, and the barometer falls, it 
indicates that the wind will move into that point. Dr. B. desig- 
nates that a revolving day^ in which the wind gradually moves 
round through the different points of the compass : as these revo- 
lutions are in the same or a contrary direction to the course of 
the sun, they are denominated direct or reverse. A direct revolu- 
tion often takes place in the most settled state of tbe atmosphere ; 
but a reverse revolution is a very general sign of r^in. When the 
Tvind is €ast, accompanied by a low. and falling barometer, it in- 
dicates that the atmospherical electricity is in what is termed a 
negative state : this is called a negative day ; and in cold weather 
this state is generally either attended or succeeded by the hea- 
viest falls of rain, but in summer by a close, oppressive state of 
the air, and thunder. The usual east winds are generally accom- 
panied by a high baromet<»r, and a strong positive state of elec- 
tricity. By shaded clouds is meant those consisting of rounded 
masses, one side of which is niuch darker than the other. When 
a* part of the horizon is occupied by large rounded clouds which 
appear to be heaped upon each other they are named pUed clouds. 
When the wind changes into a southerly point after the influx of 
^ cold current from the NW. rain generally ensues. When 
plauds sonf ewhat rtsemble bunches of hair they ar6 called Tufts ; 



18 ff I?/'. Bostock and Mr. Foster on MeUor^ogy, 

AXii the larger and more compact masses of this kind are lerme^ 
fi'ocks. Dr. Bostock then concludes bis second papiT with some 
remarks rt'latlve to istorms, and the advantage's that would result 
ifrom a number ot* accurate coipparative obserrations on this 
sulyect ; ard by restating what he considers the first object '\{k 
nieteoFf'logy, and the chief source of its greatest improvement. 

5?. Mr. I'oster fully agrees with Dr. Bostock, that the par- 
ticiUar inodificatipns of the clouds constitute an essential part 
6f meteorology, and expresses his approbation nf tfie plan of the 
^iary. adopted by Dr. B., but thinks that the BomendHturcr pub<*. 
lished a few years since by Mr. Lake Howarcf, of Plaistow, in 
|jis treatise on the various moditication& of clouds, is capable of 
clearly expressing these circumstances. JVJr* F.aIt»o recommend^ 
the following plan for a meteorological dairy. ^' It should consist 
of twelve columns beaded' a^ifol lows ^ 1st column, day of the 
month; 2nd and Srd, the maximum and minimum of tha 
theroioiueter) 4th and 5th^ ditco of barometer; Sth, the quantity 
of rsiu which; ialls ii> the course of the day ; 7th, the quantity 
of evaporation in square inches; 8th, th« stMe of t(ie hygrometer ; 
(Dr tuc's i^ perhaps t\rt best), pth and lOtb, the direction ana 
^rce of the wind; 11 th the modiBcations of c\ouds; and tbe 
)2th should be reserved for the registc;^ of occasional meteoro* 
logical phenomena, such, for an isxample, as tliondcr, storms, 
meteors, &c." ♦ 



. Ohscrvations.'^Tht meteorological student will be glad to 
observe, that the publication of tables and ol)servalionS of this 
nature has Ix^en more frequent of late, than it was a short time 
since. This will appear evident from the content? of our volumes, 
AS it did not fall to our lot to notice one paper on this subject prior 
to page 162 of volume frve ; but several have sinc<N:ome within the^ 
province of our labours. ^ Jn the first instance we stated oux rea- 
sons for asserting that it w'as desirable, tliat accurate tables 
should be kept at a greater variety of places, and air the changes 
in atmospherical piienomena correctly noted as they took place ; 
and we now agree with Dr. Bostock, ** that the lirst object is to 
obtain a fiill historical description of the successive clmnges of 
tbe atmoftphere, to notice the periods of their commencement 
and duration, and the connection which they have one to the 
other. The second great point is to invent some method by 
which these changes may be arcurately recorded.'* lie alstr 
observes, that, according to his view of the subject, tlte science 
6f meteorology must be advanffd, not only by accurate- obser- 
vations of individuals, but by the comparison of v^^rvatiou^ 
made in different places. ' 

• douds are formed of the watery particles exhaled from the 
surface of the earth and waters by the power of tUebuc; aititi 



Dr. Bostock aniiJr. Foster on Meteorology. ISJ 

tlie vapour thus emitted ts^Ay be decomposed in different ways ; as^ 
on its first entering the atmosphere, producing a fog or mist. 
After having ascended through the ^ warm air near the surface of 
ihe earth, and arrived at a colder region, it becomes conder.sed ; 
and thick cloiids are generally th« result. It may also l^e 
uniformly mixed with the mass of the atmosphere^ and travel 
Svitb it to a considerable distance from the source whence it was 
derived, and then either fall in dew or be collected into horizontal 
sheets frequently at<« considerable elevation above the earth's 
surface. The causes of these changes are probably to be found 
hi the state of the superior currents of air, which both impart 
ftnd carry off a considerable quantify of vapour according to the 
different degrees of saturation between these and the lower strata 
over which they pass; but this part of the subject is extremely 
J^elktent in such observations as could be admitted as proper 
4lata in reasoning on this head. It is thought by some pereona 
^hat there are only three simple and distinct modifications of 
clouds; hot as these different aggregates may, according to cir- 
cumstances, pass into each other, and become intermediate or 
con) pounded, it is necessary to admit a greater number of modi* 
/icdtions, apd to give names to some of the most remarkable 
states or appearances.- Some ^i these modifications are tlie 
following. 

1. Cirrus, Parallel^ fiexuous, or diverging fibres, extensible 
in any or in all directions. 

2. Cunmhs, Convex or conical heaps, increasing upward 
from a liorizon^al base. 

' 3. StraiufJ ' A widely extended, continuous, horizontal sbeet, 
increasing fr6m below. 

4. Cin^mCymiUus. Small, well defined, roundish masses, in 
close horizbntal arriingements. 

5. Cirro-stratus. Horizontal or slightly inclined masses, at- 
tenuated towards a. part or the whole of their circurofer«'nces, 
f oncave downward, or undulated, separate, or In groups, consisting 
of small clouds, having these characters. 

6. Cumulo^tratus, A dense cloud with the ba^e of the cu- 
mulus, but its upper part extended into a broad Qat structure. 

7. Cwmtlo-cirrjD-siratus^ vel nimbus. The rain dottd, A cloud 
or system of clouds from which rain is falling. Jt is a hori« 
arontnl sheet, above which the cirrus spreads, while the cun>ulus 
enters it laterally, and from below. 

But for a more detailed account of thest modifications, and 
plates for their illustration, we must refer to Mr. Ha ward's 
paper on the subject in the l6th volume of the Philosophical 
^lagazine. 



( is» ) 



On the Art of Printing with Stone, and especially on tie Progress 
which this Art has made in Germany, Bj/ M. Marcel de 
SfiRRKS. Annates de Chimie. 

Tre art of printing with stone» wfairh in Germany is stiled 
xhemisthe druch rey, or chemical printing, owes its origin to Alois 
Senejeltcr, a native of Prague, in Bohemia. About ten years 
since he obtained from the elector of Bavaria an exclusive pri* 
vilege of exercising this art for the term of 13 years; but be 
mftervrards ceded this privilege to his brothers. Some tim« 
afterwards he also gave up this privilege to jM. Andre, of OOeih' 
bach, who has since exercised it in England, in 1802, Senefelter 
went to Vienna to solicit a fresh privilege, from the Emperor of 
Anstria, which he obtained in the following year, for the spaca 
df ten years. He however soon gave up this also to Messrs; 
Steiner and Krasnitzki, and returned to Bavaria; and, in part* 
Bership with some other persons, opened a stone printing.house 
at Munich, where the art has been brought to its greatest per* 
fection. M. Chauvron was ^he first in France who obtained a 
brevet of invention to print br engrave with stone; and M. 
(juyot has only been engaged in it since his time. 

The processes which are used in printing with stone are very 
sifnple, and consist of three different methods/ Tlifi first of these, 
and that which is chiefly used; is wnat is denominated the 
method io relief. This mode is chiefly employed for music. 
The second method is the hollow method, and is that preferred 
for engravings. The third is the flat method; this is very useful 
for the imitation of drawings, particularly such as are to resemble 
those made with chalk. To print or engrs^ve according to this 
process, a slab of indurated iharle, or any other calcareous stone 
H used, provided it can be easily cut, and takes a good polisht 
ft is aUo of an advantage that the stone be of a fine giain ; and 
the most convenient thickness is from two inches to two inches 
and a half. When the stone is dried and well polished, the first 
operation is to draw the designs, notes, or letters that are intended 
to be printed upon it with a pencil. These are then covered 
with a particular kind of ink, which is considered at Vienna as 
a great secret. This ink, however, appears to be composed of a 
solution of gutn lac in potash^ which is afterwards coloured with 
lamp-black produced from burning wax. When the designs or 
letters^ thus impregnated with this ink are dry, there is passed 
over them nitric acid, more or less diluted according to the degree 
of relief it is intended to produce. The acid attacks those parts 
of the stone which have not been covered with the ink; while the 
drawinc]' ^c. remains untouched* The stone is next wa$lxed with 



Af. Marctl ift Strrei on ihe Art of Printing with Stone, iiy 

Water to render it clean ; the letters &c. are therf covered with 
commou printing ink by means of a printer's ball. A sheet of 
pap«r being put into a frame, and lowered down upon the stone« 
a brass cylinder is passed over the paper, or a copper-press press 
is used. Whtu the required number of copies have been obtained, 
the siab is polished again ; and it will thus serve ivr a consi<ier- 
%ble number of works. 

The hollow method is not much dllTerent from tlvis, except 
that the acid used is much stronger, and the design, by its greater 
action on the stone, is more in relief, and the stone mure hollow. 
This method has the advantage of rftmedying that equality oC 
tone which printing in £t;one generally produces. This method is. 
sometimes u.scd for engravings ; but is necessarily more expensive 
than the former; aud. requires heavier rollers. In the former 
of these methods the nitric -ae^ is mixed with one half water* 
In the third method still less nitric acid is used; but great Care 
must be taken that the stone used is quite fl«it« The design rises' 
k'ss above the other part of the surface than in the other methods^* 
and is scarcely sensible but by the touch. Tht kinds of worki 
that are engraved in stone are, 1. Imitations of wood cuts. 2^ 
Imitations of the dot manner. 3. Drawings. 4. Musical works* 
5.- All kinds of wriiing. 6. Geographical maps. 7- Engravings 
in mezzotinto. 

i he advantages which. result from this noethod of printing are 
stated to be a ||pculiar character that cannot be imitated by th« 
other methods, and what is still more important, the facility with. 
which it may be executed. On this head it is staled that a 
design which would require an artist five or six days to finish 
upon copper, may be efigraved upon stone im one or two. days.' 
In the same time that the copper plJTte printer draws off 6 or 700r 
impressions, the printer oa stone can take off 2,00,0. An en- 
graved copper- plate will seldom yield 1000 impressions ; but the 
stone slab will yield several thousands, and the last will be very 
nearly as good as the first. It has been tried in the printing- 
house at Vienna, to take off 30,000 impressions of the same 
design i and even then the last of these was nearly equal to the 
first. Th^y are 'even said to have carried this number of copiear 
to a greater extent in the printing bank notes. The most 
hidustrious ancb .skilful engraver of music cannot engrave more 
tha.n four pages ^on pewter in one day, while the engraver in 
stone <an complete twice that quantity. ** Every kind of work 
which artists engrave iipon copper or pewter, and vhich the 
printer executes with moveable types, may also be performed by- 
using stoae." There is also said to result a saving of one third^ 
of the expense in comparison of printing upon copper or pewter. 

One ef the chief disadvantages attending this method of print* 
ifng/ ill the difficulty which is expeiienced in attempting to give 






140 • Mr, Walfceron the P'oWerqft/iC Eye, 

either to the chaiacters of the impression or to the strokes of tM 
e&graving, that diversity of tone which imparts so much value tii 
fvorks of this nature. The same inconvenience is also to b* 
found in njusic f)ritited in thiij manner; dud the equal tint which 
is spread over it renders it less let»ible. 

Chauvron, who fir^t established a prifiting-hou^T of this kind at 
Paris, firbt traced the lines upon the stone with resinous ink, and* 
then moistened it with water. This he wiped otf ligliily, which 
soon left the resinous lines quite dry. On applying the printer'^ 
ball in this statt;, tlibse lines only became impregHated with the 
ink, and consequently wer^ the only parts which yielded any imJ 
pression. 'i'hose printers, however, who do not ma^ke 6se of any 
niti^ic acid, always produce a very infeiior kind of work ; its use, 
ther^fore^ cannot be tod stri>ngly rccoiliuieude((. 

• ^•" 

Obsertatioihi^'^lhoMgh this mode of prihting may have its ad-' 
Tantages for some sorts of performance, where appearance can 
be properly sacriticed to facility of execution, and tiie beauty to' 
the cheapness of the article, we by no means think it carf be ap- 
plied with success to the art in general. For, though we a^ie^ 
with the author of this paper that what '* the printed executes 
with moveable types «/cjy also be pertornied by using stone," yet 
only a very small degree of reflection will be necessary to con-, 
vince any one, that it is- much easier to exfciife works of this 
nature, according to the present method of settingj^ie letters, thanr- 
it would be to draw them upon the sarface ef the stone. Betiide? 
this, the present method is capable of a murb gteater degree of 
accuracy than could be etlected by nsiflg stone; as any erroi!'' 
committed in setting the press, may easify be corrected when 
moveable 'types are used ; but in printing of this kind with 
stone, if any mistake took place in-drawing the letters ii must 
he continued through the impression. 



/■' 'l-JL 



On that poxi'Ct of the Eye, by which it i$ adjusted to the Objects dis^ 

thict/y. at difcrcnt DUtar.ces, By Ez. >VALkErv, Esq»-^Phii. 

Mag. No, i42. 

» 

Tins paper is a continuation of one which ve have already 

noticed, vol. iv. p; 33, 308, and those who are -admirers of Mr. 

Walker's former essays, will, without doubt, be equally satisfied 

with this. 1. lie first observes, that the focal distance . of the 

eye becomes in general larger as the age advances. 2. He says 

that " those who have written on the properties of the human 

eye inform us, that " if a good eye views an object at the least. 

distance^ it can be seen distinctly, and then at twice that dis* 

taoce^ and tbeii at an infinite distance, there 13 about the same 



Mr. Walker on ihc Poker of the Eye! 14 1 

siieration made in tbe^gur^ of tbe eye betweeii the two last* 
^#ses, as there is between the two first;'' and having proceeded 
to copy the demciostratioQ, be adds these remarkable words*' 
^* Ilt^ce it Jbay be. deipt»n»trated« that objects at various dis- 
tance may be seen distinctly without any alteiation in the hu« 
piuurs of the eye^ 9T in ijts, otitw^rd form:^ and assuming fiomi 
bis furhier paper, that ,^^ when' a good eye views an object at thd 
l^st . distan<;e; it cuq be seen disiindtly, the rays which entet 
ifae pupil are parallel^ or &uch as diflter veiy little froni'being 
so," he finds no great diiliculiy in deducing his consequence^ 
from these premises. . 3. He describes the circle of dissipation 
which is produced when an object is. viewed within the limits of 
distinct vjsiou; and observes^ after Dr. Jurin, that other ^things 
i>eing e^ualf, its , magnitude will .be proportional to that of the 
pupil. 4» Mr. Walkcir quotes the ituthority of Dr: Matthew 
YoMng^ who asiserts that^ a person, after having been couched, 
could See oistioctly at diilbreot distances, and imagines that whefi 
this power appears to have been lost, as in the case menCibiied by 
Dr. Porterfield, the iris must have been injured in.th^ ppe^'atioti : 
for he says, that ** it is a physical truth, which any one may 
convince himself of by trJ^l, that wo mental exertion can change 
the adjustment of the eye, when every part of the iris is co- 
.^recL" 5. Mr, Adams's authority is adduced in contradiction to 
tbe common, but erroneous opinion, that short-sighted persons ge^ 
/leraUy become less ^hort«.sighted as they advance in age. d. On 
the whole, the author concludes, that the eye is a ' machine of a 
•iixed and determinate fornn its only alteration consisting in the 
dilatatioo &nd contraction of Che pupil. 



•fa*i 



Obs€rvations,-^^\Xe beg not to be considered As addressing anV 
of the remarks which we shall make on this essay to the cozi^ 
sidenilion of Its author ; We arc conscious* of our utter inability tt> 
afford him' any thing like information or iustrnction. If any 
others of. our readers should entertain doubts on this subject, we 
entreat them to take the trouble of making two pin boles, or nai*- 
row slits, in a piece of thick writing-paper, at the distance of 
about one tenth of an inch, and lookiifig through them b^ith at a. 
fine black line drawn on paper^ held with one end nearly in con- 
tact with the facBi aad^ if ^hey aro long-sighted, employing at 
tbe same time their usual spectacles ; they will then see two 
images of the line,.. crossing or meeting in the point of perfect 
vision, and they will easily be able to judge whether or not that 
point is stationary in all pcYssible conditions of the eye. We al^o 
»sfer to p. X52 of our fifth volume, as well as to our accounts of 
Mr. Walter's former papers^ for some further remarks on this 
subject. 

With. respect to the experiments being made ga persaiis wb» 
' No. 24. — Vol. vi. ♦ . u 



— • .' VJ! 



142 Messrs. Mouclel on ike Manufacture vf Tron mid Steel Wire: 

liave been deprived of the crystalline lens by an operation, I>r# 
Thomas Yoiing has advanced many reasons for'believingy that 
the faculties which such persims retain is that of sfifeing objects 
iwith tolerable distinctness at different distances, but by nO' 
means t)f actually changing the refractive powers of the eye. We 
have evefc been iiifortned, but we will not vonch for the truth of 
the fact, that sooie experiments have been lately made on the' 
eyes of the same individual, who appeared, when examined by 
Mr. Ramsden, Sir H. £ngle(ieldy and Mr. Home, to retain the 
faculty of accommodation in great perfection after the operation ; 
and that the eye, which had been deprived of the lens, appeared, 
ivhen Mibjected to the more accurate teets which had been pro- 
loosed by Dr. Yoniig, to be wholly without any power of changing' 
its focal distance, while the perfect eye possessed it to a consider- 
able extent Whatever the actual result of these experiments 
may &ave been, we shtnild hope that an account of them wopkl 
he laid befor6' the pnblid by some of the persons who were coir- 
eerned in making them. 

Note of a Discovery tf Mi*. Vacca, in Magnetmn.-^Phil. Magj 

No. 142; 

'' M^. Leopold Vacca has diHwered » fhelhod of commuai* 
eating magnetism to a bar of iroif^ without ai nmgaet. . 

** He tak^ a bar of iron oC about three feet in lengthy 
which givej no ^ign of po^ssing any magnetic virtue, as lo*i% 
as it lies in a horizontal position ; but it possesses this in a very 
(sensible degree when j^laced perpenditolar. These sign^ . disap* 
pear again whe^ it it is laid down horiisbntally,' ati^ appear again 
when it is lifted vertica%w 

^' A small bar of steel rubbed several thnes .in the satniii^ 
direction, against the extremity of the olhei* bar, wb^h situated: 
vertically, acquires magnetism ; whence the' dkcottrer concluded 
that magnetism may be communicated %& a body, without eitb«r 
a natural or an artificial, magnet.'^ 

Obsertatiom, — Sboulid Mr. Leopdd'Vac^ continue his brilliani 
eareer, with as much success as he has begun it, there is reason^ 
to expect that, in due course of time, he may diicwer that the' 
earth revolves round its own axis in a day., and round the sun 
in a year ; that lightning is electrical, and that water is com^- 
posed of oxygen and hydrogen. 

Extract from the Memoir of Messrs, MovcHEj^y of Vjiigkf in the^ 
Department de VOrne, on the MtmufaCture of Ircn and Sttei 
Wire. Repertory ofjirtSf Nos. 95 and 96 f Second Series. 

T91S is one a€ the most considerable manufactories of th\s 



Mm^s\ Mnutiel miiheMmwfrdwnloflrmimdSied ^vru 148' 

kind in France, and is said to produce a hondrcd thousaiul quin- 
tab of iron .wire aiinually, in cards for \vobl*combing only. This 
is chiefly cotosatned in France, and exported to Spain, Portugal, 
ftaly, and the shores of the Levant It is necessary that 
the atteniinrn of the mamifarturer, in the first instance, be 
directed Itotihe choice of materials; and Messrs. Moucbel, after 
trying a great many specimens,t liave adopted the iron- frooi 
,the ^departments of I'Orne and Hau^e Saone, as being the best 
adapted 'for the pjurpose. The first aifords the best wire fo^screw&i 
nails, anjd pins ; but, by reason of its ductility, that of the fatter 
^pactincat ca^ ha aia,|Ae (extremelj fine, and appears to be mmst 
free from beierogencous particles. The inconvenience oi i>e?ng 
obliged to use iron from ditferent smelting houses, was foand'to 
be extremely prj^judicialto th4 uniformity u^d perfection Ireqtrired 
in the delica^ pfig€e8.ses that are necessary in making iron wiie. 
These manufacturers therefoi^ established a smelting house of 
their ow)ii in the department, of ^aute Saoiie, wh^i>ce the prepared 
iron i& conveyed by meana of rivers ainl canals^ at a ^nialt ex- 
pense, tO! the maf^i^af tory at rAsgle* 

Wh«». the iron has been formed into an irregalar hair of ab'oni' 
sa cen^/mc/j-e ('39371 inches Ei^lisb) in diameter, they begiti'* 
f» draw it into wira. For this purpose they first pass it four 
times through the drawing plate. The fihTtfi which appeikf at the 
utmost extension of the molecules that ale arranged Ijsngth- 
waya^ are removed by heat, sttid the proc.ess fteain repeated threa 
llOM^. Tl>e whole operation is thus repeated five times, and con- 
sequently the wire is passe.d through fifteen numbers ; after whicb 
n single heating ia sufficient to fift it to pass through six others, 
sppd dl)en it is reduced to the thickness of a knitting needle. Steet 
wire heiii|p naueh harder than that made of iron, requieee to be 
passe4 thpough. for^'lour numbers, and to be annealed every se- 
cond time. The wire is drawn with either the pincers or the 
liobbin, which is a cylinder adapted to axle-trees. This last was 
invented hyi th# grandfi^ther of Messrs. Mouchel, and is used Cq 
prevent the marks occ<isiuned by the application of the pincers. 
The degree of heat required in annealing the wire must be regu- 
lated by the diameter; as upon this much of the perfection' of the 
Aia&afaeture depends. When the wire is sufficiently stretched at 
^ach heatingv it assumes a pecfuliar colour, which the workmen 
•re careful to ahserve. , 

For anneaHag the wire, these manufacturers employ a large 
elevated fiirnace, in which the wire is supported in the mid<ue 
ef the flames on bars of cast iron. This furnace is capable of 
containing seveft thoueand pounds weight of wire, so arranged^ 
that the thickest is exposed to the greatest heat; so that the 
whole becomes equally heated in the same time. An incopve? 
lupncei b6w9ver^ is exparieocfd with this furnace^ whieb leaves 



* i. 



■j^: •»■ 



144: Mes^ri.'Mauekel^on t^e Vcnuf fixture (^'Jtrmmid Sftrl fFirt^, 

the heated wire exposed to the' atmospheric air, \vhich oecasions 
both a copsi'derable loss of oxyd, and an expense in ren)ovii)g»t« Ip 
o^der to pi event this» they have invented Uiiother'^rnaee, which- 
]$ roundi and about one metre six decimetres, (near 5 feet 
3 inches English,) in dlameier; and one metre e>gfat dceimetres ' 
(5 feet 10'80'78 inches) in height, exclusive of its parobolic arch 
and chimney. The interior bt,iibis furnace is divided into three 
l^rts ; |he fir«t receives tbe cinders ; the second is the (ire place ; 
£^id the third receives the wire, which is pluced between two 
cylinders, situated within each other, and'niade air tight.' 'Ihe 
diameter' of the larger cylinder is about one metre r6ur centi- 
metres (near ^5 inches,)* and that of the inner one about one 
m^tre (3f).37 V inches;) and the fire circulates about the exterior 
^rface of the former, and within the latter. > Several ;pairs-olk 
cylinders are provided, in order that they may he changed 
every hour, w)iich is eifected by means of a lever, thai enables 
one man to draw them out or push tbeui in at pltsasure. These 
cylinders ^rp not opened till soiiie time after >tbey are drawn 
but of the fire, which prevents the oxidation that would 
iplte 'plac^ if the atmospheric air was admitted while ' the wi*-e 
4vas hot. Tl)is new furnacf is' more expensive than that which 
was previpusly^ised^ hut its advantages more than counter balanco* 
this expense, |i )S used for all wire intended for cards ; uHd the 
large furnace for that of a larger and harder kind ;, but in >t)rtler to 
diminish the formAtion of the o^xjd, tbe'bundles 6( wire, are dipped 
into a (^uaiaity of wet clay, nnd then pat into tbb furnace, and* 
auflfered io dry before the fire is lighted. 

These authors make use of two sorts of drawing plates ; large 
and small ; in the formation of which great care is necessary, as 
much depends upon the ability with which this is' executed. The 
method they employ for this purpose is to put pieces c^ iroit- of ^ 
proper size and qdnlity, into a furnace with cast steel, and inx. 
crease the' beat until the latter is fused-; then the iron is taken, 
out, and the ateel that adheres to it is amalgamated with it by 
gentle blows. , * 

It is then permitted to cool, and the same process repeated se* 
veral times, till the plate has acquired its proper form and liSard* 
ness. It is necessary that these plates should be of considerable 
thickness; and the smallest used bv Messrs. Mouchel are at 
least two centimetres ('TSri-S inches) in thickness.' Aiter the 
vire has undergone the last operation in th^ workshop ol the 
^ire drawer, and is reduced to the required degree of fme^cas, the 
Smallest of which is stated at lQd,000 metres in length tb a chi- 
Jiogram ; or 109,36'()-§- yards to 2lb. 3oc. 5dr. avoirdupois, 
by means of the bobbin, it is subjected to the process oi' dre&-f 
sage or straightening, which is esteemed the .most difhcult and 
4eli6ate of all the operations, fty this it losejB the bend^or^ cur\<t 
it had acquired on the bobbins. For the more i-eadily uuA 






Messrs, MoufJtel on the Mdnvfactttre of Jim and Sf€^ IVirc. 145 . 

effectually performipg this part of the manufacture, Uiese aittbor> 
have also inverted apparatus for both straightening the wirey and , 
(ktcrmlniBg its suppleness. Ikit for a particular description of - 
t{)ese» with other particulars, and a tabl^ oi the prices of the dif- 
ferent sorts and sises of wi^e, we must refer to the }^ limbers of. 
t^e Rq)er|4>a7 of Arts, mexitioned at the head of thi^ article, an4 
the plate by which the memoir ^s accompanied. - 

ObsrrTapions.-^Thost persons who are either engaged or iut^r 
rested in manafac4.u)res of thi^ nature^ y^e conceive would be am- 
ply repaid for their trouble of perusing thin n^emoir. It will be 
^und. tQ c^oitbine ^ much greater degree of. scientific ingenuity, 
i|^)d practical ,e:^perieuce.tlian are usually met with in similar esr 
says, and the success with which t^ese have been exerted \ may. 
^^ily b^inferred from th» tioeness of the wire produced. From 
^e above statoment it appears that a ppuiul avoirdupois of the 
smallest .wire contaips about 49)^53 yards. in :ledgtb. Now^ad^ 
slitting tlie sp^cjlic gravity of this wire to ht 7788, aa4a.pDupd 

wnf coniamTrr-: cubic inches. Therefore .. ^ x r 

f\^ * ' ' • 

■zz 'OOOpOipSSlt) inches for the area of it# section | 



/ 



' I ' ' ' 



'31^159897 

and consequently^ '001593 ^or its diameter. . \ '^. 

Another eirrumstiancip which confifms onr op'rnion relative to 
the formation of the ((rawing |riates, is, that one of' these large 
plalei reduces 1400 chiliograms, from the largest size to that of 
No. 6, which is about the lhicknes« of a knitting needle ; and 4b'0 
chiliograrns are also reduped from this size to the smallest carding'* 
wire, by being passed twelve times successively through a single 
small plate, -i'his we apprehend could not take place, unless they 
were- very perfect. 

p/i the Cortst ruction of T/uatres^ so as to render tlicm secure against 
Fire, Bi/ Mr. B. Cook. JHth Remarks hy the . Cuuductor*—^ 
Phil, Jour n,' ^^c;. 11-^. 

I^Fr, Cook commences this paper with a reference to a former 
letter, in whicTi he recommendec^ the use of iron instead of wood 
for the purposes of building ; and w^ich we have noticed at page 
4-23 of our 6th yolupnc lie then offers some general observations 
tending to shew the necessity of having, public buildings, and es- 
pecially theatres, as secure as possible against fire: which he 
says is to be effected by tlie use ^i iron, wherever it can be 
adopted. Mr. C. then gives a brief description of ^vhat he deems 
a practicable plan for a theatre, with a view of inducing those more 
jiuppdiatcly concerned in the ereciion of buildings of this nature, 



} 4p A/r.' Co^k on tie Comiruetwn (f Theatres. 

t& give the slubjeet doe consideration. All upright and ijw^ 
supporters of the stage, h^ says, should he made of iron cast tight. 
^ttcd and screwed together ; and to make the stage five proof 
from beneath, projecting edges should be cast on the bottom of 
each spar or joist, so tliat when fixed in their proper places for 
supporting tbe ftoor, ti^es or quarries made thin, migh^ be laid 
between the spars, thne Cbrming a solid fire-proof bottom. The-' 
boards of the stage are then to be screwed to the spars, and the. 
same principle acted upon throughout aU the rooms. Tlie doors 
and stairs all to be made of iron in the manner previottsly recom*' 
mended for other purposes, and as little woodf as possible intro^^ 
duced into any part of- the building ; by which means if a fire* 
took place in any one part^ it could not readily comramicat* 
to another. ' ..... 

If^e front of tl*e stage and tbe orchestra, should bt>tH*fte made* 
nf iron, which 'w*)uW affotd an opportnmty <5f easily* m;akitig 
tbem yery hfabdsonae. Jhe flttorof the pit being laid on arches,* 
eouldnot be ilt any danger of fire ; and the seats, or al-l^ast all 
the supporters of theoi as well as the framing of ,th£, V*^^ 
llhottld be iron. The front of the boxes being ca^i ki open work, 
might be made very elegant. And jthe same mode of conktVuction 
feeing keptup'through6ut, beauty and durability niigbrbe uoiteif 
in a very high degree. ^ 

*' The roof should have no wood at all in it, but be qfuxpoeed 
of hollow or solid iron, cast light, ^Md if each piece was *^raduate4 
irom bottom to top» it would still make it more lights aQ.d yet be 
equally strong. A roof of this description well secured t^ge* 
iher with screws and bolts, &c.,. would not be considerably hea«> 
vier than wood, as the iron would possess litrength equal to wood, 
at less than half the thicMess." 

Mr. Cook next enters into a comparison of the advantages and 
disadvantages that might be expected to result from the use of 
tbese twiodrlfrrcnt kinds ctf materials. The two t^iief objectieiisr 
which could be urged against the adoption of iron in the way he 
recommends, are conceived to be, difficulty oi execution, and ex- 
pense of erectitm. With respect \o the f]rst of these, he thicks, 
it is wholly devoid of foundation ; and that there would be no 
difficulty in meeting with men competent to every part of the un, 
dcrtaking : he also adds, " There would be, especially in a theatre, 
the greatest scope for geniiiS'; thus migl^t be construicted the 
most elegant one in the world ; and one, that no accident, no 
misfortune, no incendiary could destroy : that would brave the 
utmost efforts oftime.* With regard to tbe consideration of ex- 
pense, Mr. C. tlinks that it would not deserve to be compared 
with the durability, freedom ftom accidents, and the probability 
of larger ^udijpnces which the adoption of iron would afford : even 
admitting that the additional cost amounted to ten thousandi 






Mr.CookmtheLoiOtruciifmifTheafrei. 147 

jiouilds, it would be trifling when counterbalanced by thest aad 
^be other advantages tbat would result from this mode of coiw 
itruction. 

The author of the remarks subjoined to this paper, after ad- 
Vertir^ to vi hat has been said about the use of incooib^stible ma- 
terials by Mr. Edgewortb and Sir George Cayley, (see page l6d 
of our vol. V.,) obsjerves, that there is one great source of saving 
which has not been taken into the account by writers on this 
lubject ; and this he thinks has arisen from its anaotint not being 
generally known : this is^ the saving of insurance. *' Tbe offices 
were paid forty shillings for every hundred pounds insured, pre* 
vious to the burning of Drury Lane Theatre; and since tht$ 
event, they will not insure at a^ less premium than foar guineas 
pfer cent. Now the proprietors of the theatre lately erected»at 
Covent Garden, state tbe expense of erecting it at 150, OOOl. ; 
.the insurance of wbicli against fire, would- amount to ne has 
than 6, 3001. a year, if, as 1 suppose, scenery and dresses be not 
included in this e^tmate, the insurance would be still more to 
cover tbe whole. And to insure only one third of this, or 
. 50, OOOL, as on the old theatre^ the premium would be 2, |00l. sL 
year.^ Would not the saving of sbcb a sum annually, more than 
repay the additional expenditure for rendering the building proof 

against fire by the general use of iron ?" 

j^ . - ' 

Observations, — At the conclusion of our remarks oti the former 
articles on this Subject, we observed, that the introduction of iron 
instead of wood, where it could be conveniently uSed in buildings 
of this kind, could not be. too strongly recommended ; and we 
Uierefore fully agree with Mr. Cook in the greatest part of 
bis communicatidii. We, however, cannot giv^ cfur assent to the 
assertion, that a building chiefly composed of iron and store, (and 
. such a one w'e understand Mr. C. to mean,) '* would brave tbe 
utmost efforts of time ;" as all the objects with which wp are con- 
stantly surroundtid, clearly demonstrate! that immutability does 
' Hot belong to the ztsorke of man. But, without admitting this per« 
petuity of existence, we conceive that the durability would bel 
sufficiently extensive to warrant the experimen,t. Another cir- 
cumstance which ought perhaps to operate more powerfully in fa< 
TOur of the adoption of iron in buildings of this sort, is the great 
saving Tn the expense of insurance, as estimated by the author of 
the preceding remarks. 

With a view of facilitating the computation of the compara- 
tive expense of iron and wood used for the same purposes in 
buildings, &c. it may be observed, tbat from a variety of experi- 

• nnents stated by Mr. Banks, in his Treatise " on the Power of 
Machines, &c.," it appears that cast iron is from 3| to 4\ times 

. stronger than dry heart of oak of the same dimensions, and fron) 



148 Mr, Cook on the Comirudion of Tkedtfcs. 

5 to 64 times stronger tban deal. Of the different pieces of oalf 
«ne iflch square, and onfi ioo\ lonn, upon which these experiments' 
wer^ made, the worst, when placed in a horizontal position, and* 
supported at both end«f, would bcAr 66O polurds, and the best ^7 A, 
suspended from the middle; the arithmetical mean of whict> i^ 
817: but it will be safer not to estimate this at mbre than 800 
in calculating tb* comparative strength of different pieces. The 
weakest similar pieces of deal, just broke with a weight of 4^0', 
and the strongest with 65O pounds : the meawof wbich is 57^ ; 
but perhaps nk»re than 550 ought not ti> b^ used. The compa- 
rative strength 6f any other piece consisting of similar materials' 
may also be easily tixind by multiplying the breatith by the 
square of the d^'pth, and dividing tW^ product by the length ; ail 
the dimensions being takei^ in inches. Hvnce,' for A beam of tir 
16 16et h>ng,< 6 inches broad, and 9 inches deep, which 'dtre the 
dimensions ^xed by sfatute lor Londort ^fid its neighbotrhood/ 

t. 11 L 6 X S**, 6 X 6*4 .. • . 

we shall have -7: =r -r^ n 2 =: Us comi^rative 

16 X 12 lO X 12 ^ 

r x' 1* 

strength : for the standard experiment this is -^ — f-12lh. 

Therefore, as 1-1 2lh : ^ :: 556' : 13200 lbs. the actual* 

streiigth of the given beam. See alsjo our tiftli volume, p. *?9. 

Likewise!, iron being 6 ti rues as strong as deal, as stated above, 

we have 550 X 6 zz 3300 Jlis. for the weight that would bi*e*ik 

a bar of iron X inch square, and 1 foot in length. Now, in ovdcf 

to find the dimensions of u similar irok bar of the same length' 

8 4 

;*s the d^ai beam, let x denote the breetdlhl then — ,r, or *• x will 

. o 3 

be its depth and, as - : (x X — x') -i- (I6 X 112) ; : 3300 : 



x^ _ . _ _ J. . . / 



1 3^00 or — : — - : : 3300 : 1 3200 ; from which x =: ^ */30 

' . 4' 

. 2= 3-301927 inches, thf breadth ; consequently - X 3-30197 = 

4-4025()9 inches, the deptH of a beam of cast iron capable of bear- 
ing an equal weight with one of deal of the same length, 6* inches 
liruad and 8 inches deep. The solidity of the iron beam is evi- 
dently 3-50l'927 X 4-4025()9 X 1^^ = 27^91 ciibic' inches, 
nearly ; hc^nce, allowing 4 inches to a pouiid, its weight i^ 
nearly 6^S pounds. 

The quantity of iron, however, ^piay He greatly diininisbed 

xv'itlioiit decreasing its strength, by casting the beams hollow ; 

as, when the sai^ie quantity of matter is retained, the strength 

' o[ a tube is increased in a greater ratio tban that of the dm- 

iriCter^. But to what extcnt^is mode of iBereosiog th^ str^iig^k 



v''«.... , e 

Mr. Cumbtrlanas Descnpiion ^7 wis, J^c, 14^ 

bf a tube with the same qufintity, or vrhai is still more to the 
purpose, of retaining the sanie strength with a less quantity, can 
be carried with advantage remains to be determined ; and we 
regard experiment as the only sure test by which it can be 
Ascertained. It wouid not, however, be difficult to calculate 
fronj the principles stated aliove, the dimetisions of a hollow 
rectangular iron beam capable of supporting the same weight, 
with only half the quantity of iron ; hence its weight woali only 
be 349 pounds, which would still add to its strength. The 
same strength may also foe retAiined when cast solid, while the 
weigi^t is decreased about ene third by making the edges para* 
bolic, wheh circumstances will admit. The smaller parts, how- 
ever, must be made solid ; and we ;ipprehend that some difli- 
tulty would be encountered where ceiliiigs were required beneath 
the Hoors supported by irod joists ; yet these would easiljf be 
Overcome, and caniiOt be regarded «8 any formidable obetacie td 
the adoption. 

'-X-J — ILjL — ^ L-Ciij * — [ ■ Kj i m-Lu LLU s^sssassmsas^ 


m 

Jhols to dn'swer the purpose of FiU$ and cthet Jnstrumtfifs f&rra^ 
ruius uses ma(k of Stwie-uare. By G. Cumberland, Esq. 
vsith Oil Anfiofntitm by fV. N.-^PhiL M<tg. No. 114. 

Mr. Cmnberlah<i states^ that it was th^ expense flIHsitig ffotit 

the wear of steel files which first induced him to think of the 

present invention. In searching for a remedy for this inconve* 

uience, it occurred to him, that, as onr stone^wure is so harcTas 

to destroy files^ it might bfe used in the abrasion of s^.veral hard 

substances. And relative to his mode of carrying this idea into 

practice, he Observed j ** the first use I made of the suggestion 

was to fold Up in muslin, cambrick, and Irish linen, separate 

pieces of wet clay, fofcing them by the pressure of the hand into 

the intefstices of the threads^ so as on divesting them of the 

covering to receive a correct mould. These I had well* baked, 

and immediately found I, had procured aft entire new species 6f 

file, capable even of ^^estroyidg steel ; and very useful indeed in 

tutting glass, polishing, and rasping wood^ ivory, and all sorts of 

thetals.'' Ad iA all operations of abradings considerable manual 

labour is req^ir^ in first forming the too!^ Mr. C. was induced 

to think that his invcfition might be of no small importance in 

the arts, both from thb ease with which they are forned, espe. 

cisikly when a press is use^i for the purpose, and the ilrferiof va- 

Ihe of the materitl of which thede tools are composed. He also' 

5ugg6^ts their (ise for grinding speculufldfSy bdt not from expe-' 

rience. 

Alr< Nicholson, in bis annotation, thinks this ingenious hfvclta* 
tion promises to be of considerable utility ; particularly in filiikg 
Nu. 24. — Vol. vx. x ' , 



150 . Mr. Covgh on certain ^oficrtks ofSvlidi* 

" ♦ * ... - 

aud polishing a variety «( bard substances, citl)er witb or wiUv 

nul ii fretting powder. He, however, conceives that many objec- 

'tionsmaybe urged to their use in grinding sp.ecukuus, ** not 

only w'i ill regard to the intended figure, but the naluie of the 

nKiteridl." i 



Olfsnraf ions. -^U Aooh of tliis nature be for.nd en a more, 
extensive trial to answcf the purposes fcr whicl) they. are intend. 
. ed, as well as (hoy appear to liave done with their inventor, there 
can be no doubt that they will piove of considerable ^ri vice in 
the arts ; though we think with Mr. N., that the griuding of 
speculums is not one of the purposes to whleh .they will be.applu^d 
with advantage. 



Ah Inquiry, Gedmetricai and Arithmetical, into certain Properties f*f 
Solids in generah and of the Jive rcvuhir Bod'is in particular^ 
By JoHK GouGH, Esq.^-'Phil. Juvrn. No. 115. 

This paper consists of delinitions, axioms, propositions, ard 
corollaries with their requisite denwnslrations : >wilh the first 
three of which we shall present our mathematical readers, leaving 
the demonstrations to be supplied,, and the corollaries inferred, 
by their own ingenuity, 

Deiinitions. — lit. An edge of a solid is a line terminated 
bv two of its solid angles, and common to two of its adjoining 
faces. 

DeJ. Qnd, From PtippuSy lib. 5. Ordinate plane figures or 
polygons are those vvhich are bounded by equal .right lines con- 
taining equal angles. 

V^f 3rd. Two or more plane figures are said to be of the same 
<lenomination, when each and all of them are bounded by the 
same nuniber of right hues. 

Axio.MS.— Is^ Three plane surfaces cannot contain a solid. 
Ax. '2nd, Any required solid may be cut out of a given solid. 
Propositions. — Ist. J.et r, /, and i be the number of the 
faces, solid angles, and edges of a solid, bourdt- il by polygons of 
, the denomination ?i ; and let ;p denote the number of those poly- 
gons, which hound each solid angle; of ihe body ; then we hav& 

nc pt 

*- 2 - 2- .. ' . '■_■ 

Prop, ^nd» If a solid angle be coi)taicied under p planes ; and a 
solid angle be cut off by any plan^^ .the s<cljou Avill be a plane 
bounded by\p right linesj^andp plane angles. . > . 

Prop. 3rd, If a solid be bounded by surfaces of any kind, a«d. 
Cf li Sy be tl>e number of its faces, ^olid ^^le$, and edge$ ; and 
OM pf its 3oUd .angles be cut otT.by b, surface of any kind^ tlie 



/, 



rr 



Dcsttfpt/dn of Mr. Prior'jiKHock Escd'pcfhcni. f^^ 

increment' of ^c '^together with thfe iticiemeAt of'i =::'tbe int'l*^ 
nientofs. :. i ■ . ' • v ' c-. .' - - .■ • >/ 

Prop, 4th,'l(i\ 55(i1id of any Ivind hav^any mimber of its salid 
angles ciitiilf by asntuice'of iiirv kind, so';i?*to chantie UVe nuhV4 
l)er of its laces : the nic'reiiK-nt t>l' x: toiiel'tiCr AviUi the kicrfetVierif 
of ^ iz: the increnieiil of a*.""" 

Prof/-. t>fh\ f.et r, 1. 1 dttiole tlie"niih*i>j^> affaC'e**, s(»]id\ti>ycs, 
and edges 'of any ^d\x\ whatever, tx^y(S we have the following: gen'e* 
nil expression ; v -|- t — *''"2 n ^v. . ^ ' '. ' "' .'**'*" 

Prwjo. €f/t. iWu solid bomidetl by poh-got^s of' t?he snnrle t5^nel^ 
minution ; put f: equ.il the numi)cr of iidrs ot'einh poh^i^'or?^ 
p rz the rimjLer- of polygoirs which' t(UJ(*h 'tac h " S(Uid itr»gU^? 
then C rz -ip ~- ^p ~f i.\7" •— /r;?; ^ = -U '-^ '^i)) -f* Cn — h'p^^ 
s ~ 'l';//) -f. 5?/? -i- 1!;/ — ^ ;/y5 . •>'.:.•. v c -. 'i 

yVr;;. 7^^'. 'ihe smu of the plane An<^ies- bmind'n^*. tlfe.-i^^ 
enisles of a re»;ular hody zr Hrp — i(vp •L-.'-^j/-^- ^iri -^^/^'t *' '^ 






• Ohsrrtntion s'.-^Oxif math^niaticAl 'readers Hrlll -recufffy 'pe^^i^lVtd 
that this cominunica'ion of \lr. 'Gour^h is iot>feW u fef^tt-utafiV'S 
than u nrnctiriil naliue ; 'aftd th'at it "hear.-^ evidt-nt murl^s'of i«*>ei 
iiuily ni()t ti«\v()rLhy'of'ihe rq)ij"ti\tioi]'of its aiilhoi'. • ' ' '' ^ 



.t- 



g-ii ■.,.■■- '■"" . ■i!'^ jp " ' ' ' ■■•i^.i^.i — " n-j j ■ ! *iii;ui.}"i;' uir'Ti.'v irr > 



Vcsvriftmn.vf a:clock Escapeimnt, rmcfitedin/rMr. .•Q^os.gx. Puioa 
J«//. l)'an\, JSoc^cti^ajyirtsiXdL XSil<'rl, 

Int this escapement a s}5ring detent' Utc^^'s wj^uihst one of Uid 

teeth of the swing wii-eel, and pre\eiits it fro:ii running dowo fj'ji 

the action oftlie uiaintaininr; power, WhW'e anotii^^f Sj)ring deleni 

<Mi the opposite side of the wheeP-vvhen left tit liberty unl(»cks this 

former spring, by acting ngaii^t tlie end of a-small arc conmjcted 

with it, and jeni«>ves it Iroiu the tooth of^tlie wheel against whi^Ji 

it rests. In this contrivance it is necessary that the detent 

spring, the impelling spiing, and the pendulum rod, all be fi.xed 

to one C! ntrc, aiid thu hiLter spring ho so much stronger than i}j6 

former thiU it may always be sufficient to unlock the wheel. 

^Vhcn the pendulum moves towards the left hand, the impelling 

spring unlocks the wheel, and a togth falls against the pallet 

where it remains till the pendohtm returns to its former position. 

** Then moving the impeHing spring, and the wheel being freej 

ll>e weight oii its axis causes it to advuncie while it escapes one 

tooth off the end of the pallet or spring; and Another tooth is 

locked against tho detent spring, 'as before, while the pendultirii 

returns, *and^ the impelling spring again unlocks the detent:- as 

the impelling spring moves- towards the left, the resistance it 

nieets with -from the elasticity of the detent spring in unlocking 

ia returned to "It, so'that trbereis no nwre p'6<vcMost Ibairw^i 



»» 



14?^ Captain Pasle/$ Account ofthc^tnt^ Tdcgrafh 

caused by the pressure of the wheel against the deteot spring, hj 
vfhich means it is fr^() from the loss of maintaining power, 
which is evident in all detached escape nrents \ have seen, bj the 
pendulum or.crutch^ ht, touching a spring, or lifting a lever tq 
regain the position for unlocking the wheel/' 

■ 1 1 II ^mmmmmmt 

0^««T<i^w«*.— Mr Prior states that " this escapement will d« 
ibr a pendulum of any length, and the frictipn is sk* small that it 
does not require any oil, for it may be made as little as the tooth . 
pf tiie wheel can sufficiently touch the impelling spring, and yet 
be properly scaped.-' The sopicty of arts appear also to enter-? 
tain ^ high opinion of its utility^as their silver medal and twenty 
five guineas were yote-d to Mr. Prior for his invention. We, 
iiowfcvef, are by no means so sanguine in our expectations on the 
•anie subject. It is evident from both Mr. Ps description awd ' 
the ^gure by which it is illustrated, that the impelling spring 
must be of sufficient foice to overcome both the elasticity of the 
IJ^tent spring ap<i |he friction of the tooth against its extremity : 
and it ought to be remarkecl that ihe detent spring is removed 
fron^ the tooth by a sliding motion, and \ve tbeiefore apprehend 
not with so little friction as Mr. Prior seems to suppose. He 
states that when the pendulum. an ives *^ at the perpendicular, it 
meets the impelling, spring, and carries it along with it, until 
the tooth of the wheil whicl} rests against it, escapes from the 
^nd of it, and another tooth of the wheel conies to rest against 
the spring detent. The succeeding vibration of the penduhim 
sepeuts the same operation." Now as this united niotion of the 
pendulum and the impelling spring is in a direction contrary to 
that of the elastic tendency of the latter, we are wholly at a loss 
to conceive how this motiop can be effected without considerably 
checking tht vibrations of the penduluiii as th,e moving power. 



Description of thi French Telegraphs used •« the Coast of Fhnders^ 
Sfc* with Observations on thp same, and a plan of a Fol^gravima^ 
tic Teicf^raph on a new construction. Bt/ Capt, C* \V. Pasley, 
Xifthc Roi/al Engineers, Phil. Mag. No. 1 4.5, 

TiJ£ French Telegraphs here described, consist each of an 
upright post, having tliree arms attached ti^ it, all similar to each 
other, and each moveable about a separate axis. One of tli^se 
axes is near the head pi th|^ post ; and the disis^nce between the 
centres of motion of these arms is rather less than double the 
length of each arm* The high&st ot the three armd can exhibit 
fieven distinct signals, but each of the others only six. The tota.^ 
number of combinations which can be made by these three arms 
will, therefore, he three hundred and ninety oue» *' As onl v 

/ 



Captam Pasle/^ Jccount of the Trmch TekgKf^pK ^^^ 

three bodies are employed iti the FVenrh Telegruph, it njay there- 
fore appear saperior to the Admiralty TeUgr-aphs visetil in Kngl^ifid) 
which by the combitiaticmof double that uuiiiber ot'bodies cao 
only iTiuke sixty three distinct signais^'' ' 

Capt, Fu;>ley thinks that the iiiechaaism of tta^ French Teler 
graphs was imperfect, or the niet) cmploy^^d in working tbet^ 
unskilful; as the signals weie made and repeated wjiii an vn. 
laecessary loss of time. He observes that tbc^ arms ^vhich wer^ 
painted black and appeared like a solid siibstance at a distance, 
are made like a Venetian blind, to diminish the action of the wind 
in bad weather. Each arm ha» a counterpoise of thiii materials 
painted white, which only becomes visible when the observer 19 
near the telegiaph. When in use« each arm can be shown in a po«- 
sition on each side of the post inclined to the horizon in an angle 
' of about 4^ degrees, in a hoiizontal position, or at an elevaiiqa 
jDf about 45 degrees above the horizon. The arm fixed near the 
upper part of the post may also be seen vertically, which con^ 
stitutes its seventh position. Mr. P. was informed that the last 
arm is not shown in the vertical position, and if so the numbef 
of distinct signals will be reduced horn 391 to 312. From this 
ilescriptiont it appears, that the French have adopted the priok 
ipiple of motion employed by Capt. P. in h's nolygraminatic Tele* 
graphs, with this difierence, that iiistead of fixing two arms on 
the same centre of motion, they only make use of ^)no. 

Jt 15 then stated, that instead of employing several posts as 
jn Cai't.. P's former invention, a telegnph ot the same description 
may be made with one post, since most of the signals are the 
same in both casts, except in the. latter only the pair of arms at 
the top of the post caQ be seen in their vertipai position, winch 
4dimini&h«s the number of signals. He however thinks that a 
telegraph upon this construction, would still be sufTiciently copious 
jind powerful, and states that if four pair of arms were used, the 
number of distinct conibinatic^ns would be 308,791 • If three 
pair of arms were employed, the number would be i^,.9S5. And 
if only two pair were made chtiice of, the number would' be reduced 
to iiZ7' liven in this reduced state Capt. P. thinks that a 
telegraph of this kind wou|d siill be superior to either those used 
hy the French, or employed by the British Admiralty ; as the 
signals would be equally distinct, and much more numerous. A 
4lisadvantage attends the use of several posts arising from the 
space they must occupy, in order to admit the motion of the 
armSi but this space maybe reduced to about half, by* making 
the posts of unequal lengths, so that each pair of adjacent arms 
sxiay be exhibited above the other. 

Obierv(ffumi.^^\\ii have already givcn,a description of Captain 
.^ii^ley's former inventioa at page 6 of our 4th volume; and 4 



! st Mr. Umbers MMod'offo>yfiyf^foncflrd i/rips, -S (*. 

ivistorical sketch of all the pHncif>al inventions oh thesnhj^rt At 
page 335 of our 5th volume.' We^'tl/Hik that the eh^p^otiuei^t oV 
oee post -irtsteaLdofseyeratl; as atl/>p<ed by the Frenf h, an«d notfr 
proposed by Capt. P. is an imj>n)ve'irient or at least a c()rlvenifn^e'; 
und we are also irtctiried to prefer the \3?<? of doublctit-tbal vf 
single arms'.' By-comparhig •the-'descri)>6:oh coocaMicd wf tl>i* 
arcicle, with that at p^ge 33? ^(A''*i'^\.Vi of thh' ii'Oikl''\t'\v\^ 
'readily be perceived that ibe-presVtiV'FrcHrh telegrai'hs ami Can?. 
iPasley's are modifications of utyfwe^'invesited' by -i^f. C/f/r'pe ih 
1793 This mode of-Capt, P'* is rerUii«?y iW<;«^iiious, a'n^^ a|>* 
parenlly siipple, rut we conceive that it does'^not admit of hu(%. 
n ready application to practic<i as he seem.? to 8Up[>oso; for ^ 
considerable dilficuUy and delaV' will arise indistiir^ifi'&hlng the 
diOcrelU sigitals wlien i hey are tiiimeious. and' aisijMving fo each 
4t8 proper number. ' As this incimi'enie.nce is avoUleii in Mnjof 
L»€ Hardifa iiu'eritioo, di'scribed at page -^3 4- of our*.>th Volmii**, 
^e think that i^\f of our readers, ftfter an accurate coro'pLirison of 
the two. methods, will hesitate 10 'give the pVefer^ence to the 
latter, • 1 - 



'^mti^mtmm^f'^^mmjtm ^ fi ■>< 



Ai'cr.uiit of a Wit hod of d riving or forcing forward S/'tips 0/ ot/t(r 
ViShil< bij tilt poucr if Stawuiiugtms, Jh/ Mr. Jauls Li^'a*- 
KtR. licptrtori/ iff Jrtii» ]!^o. i^O", Second Scries. 

This invention consists of two difierent methods adapted to 
the same purpose of imptlling a vessel in any direction at pleasure. 
The fh'fct of these is that of a^jiplyirg a. bucket, sirniKir to that 
of a lifting pump, which is to be worked by any sufficient poAer 
backwards and forwards in a tul>e or trunk, fixed to the vessf4 
in the direction 'of its required motion, or nearly so. The vessel 
is nioved forward by means of the bucket tfrawin:.' in tht* waier 
at one end of the tube, and delivering it at the other end ; and 
for this purpose the tube and bucket must be provided with 
valves similar to those of a lilting pump. 

The second method consists of an improvement on that in 
whidi a forcing pump has been used. In thv present case the 
water is drawn in by the piston of ihe pump in a direction p^^* 
riillel, or nearly parallel, to the intended motion of the vess* f, 
instead of perpendicular to it; but in a direction the reverse of 
that of the recjuiied motion. By this means the effect of draw- 
ing in the water is combined with tt at of forcing it out in the 
moist favourabh^ direction for giring an impulse to the vessel to 
be moved. ^ • 

Any adequate powder may be used with ^either of these methods j 
and neither this nor its c\ode of application Mr. Linakcr considers 
as any part of his invention ; I^ut he thinks the steam-engine i& 



O/t'tkcCo^iposiiion a/itl Decomposkion-^ Forces* 15^ 

^r^f.u^y: tjm ^e<:t,.p9Wer.U]at.<'ni) b^ applied. Mr. L. also states 
thcii i^ ;^o<i>« «j(()eruu'^i>ts wLif^i hehns made ^vill] a heavy boat' 
thiity <>iH* icet l(/oj:V, w.tb a single Uicket acting, *ii cording to the 
fir«;t ot the two methods, and moved with a power ot eight n^en 
U work it liv liie hand. ih8 in(HH)n of the bo4tt ^Tas at the rate 
of 3i niikji per liour. lie inleis iVum what lie observed in, 
these expt^rlme^ts, that a proper sea-going vehstl might be dri- 
ven by a s»tea|u*engine at the rate of bix nules per bour« 

Ol^rrx'afionx.^^We have alrf^ady stated onr opinion relative to 
tye (»t)j'Ct to be eftVcied by lhi.>< contrivance, in our remarks on' 
M( stirs. 'I'revaliick and l)i(k'.n>on's |)-.itent for machinery for the 
f;u." piirpiise. See page l.Of) of vol. v. A steam-etigine is 
di'emed tiir h<^sl firi-t mover in bolli methods, liiit respecting the' 
best niLM|(- <»i"-iij)pl\ ini; it, there may he veiv iiiflVient opinions. 
.Mr. L. \\\s iiUo out. lined a pat^nt fen* his invention, from the 
^pecincation of which, part of the above coii.munication is an 
exira'ct. 



On tie drutposilim' end Duumty.fjs'ttioi) of Forces. Translated from 
" 'IraitG eiementaire de ^ftati'jiie. Par Gaspard J\Io.\gk," by 
J\/r. W. Maurat. PfhL Ma^. No, W:), 

As this paper is of a geometrical nature, or.r vrant of phijtes 
.necessarily prevents us Uom entering into particulars; we shall 
thereiore confine ourselves to a brief statement of the introduc- 
toiy remark?, axioms, and pn^posilions it lontains, and leave our 
mathematical readers to snpplv the demonstrations for themselves. 
When a force, applied to a deternuned point. of a solid body^ 
draws, or pushes this booy in any direction; the force may be 
considered as if applied to any other point in the bodi/^ in the 
same direction. The force may also he regarded as applied to 
any oihei* point out of the imitf in the same direction ; piovidcd 
ibis point he invariably attached to the body. 

Whatever may be the numlver and direction of forces applied 
at the same time, at thc.same p9int, there alvvuys exists a single 
force wbkh cither can mdye or tends to move it in ti>€ same, 
manner as all the forces togethe^r., .This single force is called the 
re^lfufit, a^d the several for^res >vb.ich com])ose the system, aad 
net together, are called composauts* 'J he operation by which 
the r«sullant of several given c«m^posant forces is obtained is 
called the Cmnposition of Forces, and that by which the compo- 
sants are found ;wben the resultant is known is denominated 
DccowpQsition of Forces, 
. Mioms^-^ I . A point cannot ,910 ve .s^v^ral ways at once. 



lis On the Compoitfion and DceowpesiHon oftarttti 

2. Two eqi;al and opposite for^'es, applied at tfce same tirai? 
t6 the same pdfnt, destroy each other's effects and are m equiUbrio : 
and reciprocally, when two forces are i/i equilihriOf they arc e<|uat 
and opposite. 

3. \i several forces applied to the same point have all the 
same direction, and all act the sanii; /vay, the cflfect produced 
i» the same as would be produced by a single force equal to their 
stim, acting the same way, and in the same direction ; tbis single 
force is therefore the resultant. 

Hence it follows, Jirstt that when two unequal and opposite^ 
forces are applied to the same point at the sao^e time, the re- 
fiultat?t will be in the direction of the greater and equal to their 
difference. And, sccondlif^ when several foices act upcm a point, 
some in one direction, and the others in that Which is opposite ; 
and the sum of those acting each way is obtained, the resultant 
of all these forces is the ditlierence oi these sums, and i» directed 
the same way as the greater. 

PropoHitwtvi*^!, If to the. extremities of an inflexible right 
line, two equal forces be applied, both of which act the same 
way, and the directions of which are parallel to each other: 
then \. Tlie resultant of these forces is parallel to them, and 
passes thr^uu^h the middle of the right Ime. 2. The resultant is 
equal to the sum of these two forcts. 

2. If to the pxtremities of an inflexible right lin«i, two unequal 
forces be applied, having parallel dirertions, and acting th^ samei 
way ? 1. 'I'he resultant is equal to tbdir sum, and its direction ifs 
parallel to that oi the forces. 2. The point at which the re^ 
su'tant is applied divides the right line int«> twoequdl parts which 
are reciprocally proportional to the forces. 

3. Any number of forces, the directions of which arc parallel,- 
and which act the same way, being applied to diffefent points gi- 
ven in position, and connected in an invariable iiiunner; to deter.^ 
mine the resultant ot all these forces* 

4. Two forces applied to the same body cannot have a residtant, 
unless their directions concur in the same point, and are con* 
ti\ined in the same plane. 

5. If the duections «f the two forces applied to two points of 
the same body, are containrd in the same plane, and conftir jn a 
certain point: I. The direction of the resultant of these forces 
will pass through the point of concourse. 2. The direction of 
fhe resultant \8 in the same plane as those of the two forces which 
are its composants. 

Lemma.-i^U a power be applied to the circumference of a circle^ 
moveable about its centre, ^n the direction of a tangent, itbas 
the same tendency to turn the circle about the centre at tvbat. 
ever point it be applied. 

6. When the directions of two Ibree^s are ift tlie eame plane^ 



On th Con^fhUhn trnd^Decomposkhk offarpe^* 157 

•anil concur in the ^ame point, if we take upon these directions 
two right lines proportionul to the forced, and Complete tfi'* 
parallelogram ; the direction of the resultant of these forces will 
be that of the diagonal of the parallelogram. 

7. When the directions ol t^<» forces are comprised iu the 
^ame plane, and concdr ia the saine pointy if two lines be taken 
as before, and the parallelogMm completed ; the resultant of 
, these forces will be represented, in both quantity and direction, by 
the diagonal of the parallelogram. 

8. To determine the resultant of any number of forces, th^ direc- 
tions of which, comprised or not comprised in the satne plane^ 
concur in the same point. 

9. To determine the resultant of any ndmber of forces 
Whose directions, comprised iu the same plane do not concur 
in the ^ame point} whose points of application are connected 
together in an invaLriable manner ; and whose magnitudes are 
represented by given liOeSj situated in their directions. 

10. If three forces have their nwignitudes and directions repre-" 
sented by the three edges of a paratlelopipedori contiguous to 
the same angle^ in such a way that the forces have the same 
ratio to each other a$ these edges ; their resultant will be repre^ 
sented, both iti magnitude and direction, by the diagonal of 
the parallelopipedoD contiguous to that angle. 

Observations. — Siiich of olir mathematical readers ag ate either 
iicquainted with the reputation of the author, or have ^een the 
original work, will not need our recommendation of this article; 
those, however who may not have had an opportunity of peru- 
sing the original, will not cooceiva their time to have been ill 
employed, in reading this translation. M. Molige has treated the 
Subject in a satisfactory manner,. as far as he has carried it. 
Which is far &om the extent of which it is susceptible. This subject 
l)f statical equilibrium has also been treated at considerable length 
in the first book <ni Dr. Gregory's Treatise of Mechanic* ; where 
the analytical method is employed, and all the most, important 
elementary propositionsconnected with the parallelogram of forces 
with their dependent corollaries, are perspicuously demonstrated, 
and compressed into a small Apace. Mr. Gough has likewise de*- 
monstrated,- geometrically, some properties of parallelograms, 
and shewn their application to the moments of forces, in an essay 
published in the 6th number of ibe Mathematical Repository. 
This, we apprehend, Ue did in conseqtience of not knowing that 
it had previously been done by Motigt and Poinsot, Much in- 
formation on this subject may also be obtained from the works 
of other authors ; and we would particularly mention the treatises 
on iriechanics by Legrange and Prony. 

With regard to the different methods of deducing the primary 
No. 24. — VOL. VI. T 






15S On the Co7npo$ition and Decompontion of Forces. 

))ropopa8ition concerning the parallelogram of forces, wc rady 
embrace this opportunity of, observing that some authors have 
commence4 their investigations by means of two equal, forces 
acting ill parallel directions on a straight line ; others, by con- 
sidering three equal forces as acting upon a material point, and 
making angles of 120 degrees with each other ; while a third 
method is that of two 'equal forces acting perpendicularly to each 
other. Monge and Pvinsot have made use of the first of these 
methods. The second, we believe, was first proposed by D'Alcm- 
bertf in the Memoirs of the French Academy for 176.9. It was 
simplified by Francccufy 'in his Mechanics ; and they have been 
followed by Gregory, who has not only rendered the demonstra- 
tion more concise, but also freed it from some objections which 
might be urged against those given by the French authors. The 
late Dr. BjobisoUy by ingeniously uniting the demonstrations of 
Bernouilli, D*Alembert, and Frisi, has, in the article Dynamics, 
Supp. Ency. Britan. deduced the same conclusion by a series of 
dependent propositions, commencing with the case of two equal 
forces acting at right angles to each other. 

The den^pnstrations given by both Monge and Poinsot, 
are simple and conclusive, if the principles upon which they rest 
ran be admitted ; Poinsot's, however, we think, is entitled to 
the preference. This method of commencing with equal and pa- 
rallel forces, acting upon an inflexible right line, seems to be 
objectionable, on the ground that it includes in it the property 
of the straight lever; thence, involving a proposition, which 
ought to be the subject of a subsequent investigation. It is there- 
fore a retrograde step in logical arrangement, to infeK»the nature 
.of statical equilibrium from the property of the lever, when the 
latter- ought certainly to be preceded by the former. In our esti- 
mation, the mode of commencing with the action of three equal 
forces on a material point, the directions of which nrak^ equal an- 
gles with each other, is the most simple and natural ; as it is not 
only free from the objection which has been Urged against the pre^ 
ceding method,b \xi is also independent of any prior consideration, 
and rests upon principles that may. be considered as axiomatical. 
The case in which two equal forces are supposed to act upon a 
-point at right angles to each other, is certainly not so obvious 
a sourte of inference as that in which three equal forces are em. 
ployed, in the manner last stated ; and therefore we are induced 
to prefer the former. Other authors have derived the same con- 
clusions, from the consideration of virtual velocities } but this 
mo^de is strongly objectionable, on account of it8 involving ideas 
that are foreign to the subject. 



I 



( 159 ) 



■HCH 



J)acription of an Eye Bath^ to clear fhe Eye from extraneous Mai-- 
ters,.a/id to assht the Sight. Bit Mr, JoHs Duckett Koss.-r. 
Tra?i. S0ciety of ^rtjf, VuLXXP^lI. 

Tjiis apparatus conbists of a stand or pedestal supporting a 
glass vessel, of either a globular or any other proper form. 'J'his 
la,st has a neck at the lower end, and an apertujc at the top IQ 
fit thie eye. The neck is cemented into a brass tube, screwed into 
an ornamental piece of brass work, in the upper part of the pe- 
destal. This tube contains a common pewter syringe, the end 
of which is cemented into the neck of the glass vessel. " When 
the instrument is used, the glass vessel is to be partly filled with 
water, (or any other liquid with which the eye is to be syringed,) 
so as to cover the orifice of the syringe ; tlie patient then places 
[ his eye over the aperture in the glass vessel, and suddenly lifts 

up the brass slider, to which the handle of the syringe is fixed, so 
a? to force the liquor contained in the syringe through that in 
the glass vessfcl into the eye; the liquor which covers the 
point of the syringe takes otF the force with which the liquor 
would be thrown into the eye, so as to render the operation not 
in the least painful." 

A more commodious but less ornamental form of the same 
apparatus is made by soldering the syringe into a vessel of 
japanned tin that contains the liquid, the globular glass being 
laid loose on the top of it ; and the whole placed upon a table 
-when used. 



Observations ^-^We are always glad to notice the inventions of 
! ingenious men, when their ingenuity has been directed to a prac- 

i" ' tical object in which success must constitute a, general its well as 
an individual benefit ; and this pleasure is more heightened in 
proportion as success seems more certain, when this object 
is more immediately connected with the particular pursuits 
of the inventor. This is the case in the present instance. 
Mr. Ross, being employed in the jewellery business, had fre- 
quently suffered from extraneo\]s substances entering his eyes, 
and therefore ei»deavoured to discover some means of relief under 
such circumstances, when they occurred either to himself or 
ethers ; and his success in the invention of this eye bath, is 
attested by certificates from eight respectable gentlemen, whose 
p-rofessional ability>or practical experience has enabled them to 
think highly of the advantages that will result from Mr. R.*b 
invention ; and the Society of Arts rewarded him with a pre- 
im of fifteen guineas. 



( m ) 



•mmeet 



'ff^^mm 



REVIEW OF SPECIFICATIONS OF PATENTS, 

PPBtlSIIED IN THE REPEBTORT OF ARTS, HANCFACTURS8, Sc^^ 

During the Months of April, M/ry, and June, 1810. 



Mr, JoiiK White's Patent for the Discoveryofa Substance ^capabk 
of being converted into Statues^ artificial Stone, 4'6^ Dated No- 
vember, ISOp. — Repertory of Arts, No/ 95, Second Series, . 

Instead of the clay or other argillaceous earths dug out of 
the ground and usually employed >" the; manufacture of the several 
articles enumerated in the title of ^his specification, Mr. Whit^ 
hiakes use of the alluvial soil, or siltage, taken from the bed 
of the River Tlianies, or from the creeks^ openings, iir cavities, 
in its shores, into which the Waters of the river are suffered to 
flow in London, and its vicinity, and within the flow of the tide. 
By vavi()u8 experiments, Mr. VV« found this soil ." to consist for 
the most part of argillaceous earth, clay, or chalk, and sahd from 
the uplands, along with materials of the nature of pit-coal^ asbes^ 
sand,. and with the remains of organised matters." Sqch parts o^ 
this deposit are to be selected as are most free from worms, and 
aquatic animals. These niatepali are then to be mixed with 
such portions of natural clay or sand, oi either of them, as may 
be deemed necessary, with a view of improving them and ren- 
dering them more fit for the intended purposes; after which they 
are to be made into the required articles by the usoal methods. 

Observations. — -We should imagine that the novelty pointed out 
in the specification of this patent, is by no means the most es- 
sential part o? the manufacture t6 which it relates, the quality 
and quantity of the materials to be mixed with the mud, as well 
as the management of the mass, being prbbft^y of much moit 
importance to the properties of the articles to be fabricated. 



ST 



Mr, Marc Isambard Brunel's Patent for cutting Fencers or 
thin Boards by Machinery. Dated September, 1806". Repertory 
of Arts, No. 95, Second Series, 

. As Mr. Brunei's specification is accompanied with fi\'t figures, 
four of which are very complicated, we cannot attempt any par- 
ticular description of the machinery by which his object is to be 
accomplished; and shall, therefore, only re;i)ark in general terms^, 
that it consists of a plate, steel cutter or saw, put in motion by si 



J 



Mr, De Heinc\ Patent for Improvements on Prestes, l6l; 

suitable power and apparatus, and of a platform upon which the 
wo«d to hf rut is supported and moved. To effect this latter 
purpose it is capable of being moved backward and forward 
on the frame on which it rests, and also in a vertical direction 
by means of four screws, that are used for effecting its elevation 
or depreiuion proportionally to the thickness of the veoears to ' 
he cut. 

Its general mode of operation is the following: The piece or 
pieces of wood to be cut (for more than one may be cut at one 
time,) are- fastened on the platform by means of cement or glue; 
and the slider containing the cutter being put in motion, the work- 
man attending the engine adjusts at first the platform to a , 
proper elevatioui propels the carriage on which it is supported 
by the assistance of a* proper wheel, and guided by the apparent 
jeffect of the cutter, continues to force on the carriage .till the 
veneer is entirely separated. He then moves back the carriage 
by means of the same whcpl, and prepares for another cut by 
.elevating the platform to the thickness of the veneer required, 
and then proceeds as before. 

It is obvious that the cutter requires to be kept perfectly flat 
and true, with respect to the propelling motion of the carnage 
which supports the wood, and the motion of the slider in which 
it is fixed, and also very sharp. For this purpose the inventor 
'^as added to his engine a lap, upon which the cutter is to be 
ground when necessary. 

Ohservathns. '■^This apparatus appears to be well contrived for- 
performing the operation for which it was intended ip a more 
effectual manner than could be diine without some similar ma- 
chinery. Ic is however, of rather a complicated nature, and 
both its first cost, ^nd the expense of keeping it in repair will 
be considerable. 



1/r. AuGtrsTus.ftj^EDRRiCK De Heinf/s Patent for Tmprovemnits 
on Printing and Stamping Presses, pated February 1810.— iif. 
pertory of Arts, No, 96, Second Series. 

In this improved method, instead of applying a screw for the 
power, Mr. de Heine makes use of two sectors, or a sector and a 
cylinder, or a sector and roller, to moveA)ne against the other, by 
means of a single or compound lever. This lever is fixed into a 
moveable spindle, the upper extremity of which is inserted in the 
top of the press frame, and its lower extremity is cut into two op- 
posite sectors with their convexity downwards. The lower end 
bf the spindle works by a smaller part, in a hole in the centre of 
'the piston head, and the upper end meets a screw in the frame by 



l6t Mr, Mantons Vaicnlfor improved Thve^keepcrs, 

which the degree of pressure is regulated. The V^ad of the pis-» 
ton Is also cut into two convex parts, against which the sectors 
of the spindle work when the lever is moved ; and cause the 
piston to be compressed as in the use of the common screw, with 
this difference, thai as the descent of the piston decreases in velo-r 
city the power must increase in the same proportion. . This 
spindle may also be applied to a fly press with very little varia- 
tion. The sectors and the parts which come in contact with them 
must be made of some hard substance ; the patentee prefers steel 
or iron case hardened. The diameter of the moveable spindle, 
and the snegs of the sector may be made of any size, according to 
circumstances. 



Observations. ^^Tht experiments of Ferguson and Coulomb have 
proved that the least friction is generated when polished iron 
moves upon brass ; we would therefore recommend that the con- 
vex pa!;'ts (tf the spindle and piston which come in contact, should 
be made of these metals, instead of iron or steel alone. 



AV- JoHH Manton's Patent for improved Timemkeepers. Dated 
December 1807. — Repertory of ArtSy No, 96, Second Series, 

Mr. Manton's patent improvement consists of an instrun.ent 
or machine for time-keepers to act in vacuo, and this is so con- 
structed that they may be wound up without admitting the ex'ter- 
nal air. The machine which is intended to preserve the time- 
piece in vacuo, consists of a variety of parts, which tlie patentee 
lias separately described by the assistance of a complex Hgure ; 
we, however, shall not follow him through this description but 
rnerely give a general idea of the whole in as few words as possi- 
ble. The time-piece is properly supported above a circular plate 
of brass made perfectly smooth, and a glass receiver placed over 
it. To the low6r side of this plate, two stop cocks are attached 
by means of screws ; one of these is connected vvith an air-pump, 
for the purpose of producing a vacuum beneath the receiver ; and 
the other has a barometrical gauge appended to it, in order to as- 
certain the state of the vacuum in which the time-keeper keeps 
time. An apparatus is also fixed to the under side of the plate, 
by which the time piece can be wound up without adm tiing the 
air to enter beneath the feceiver. When the necessary vacuum 
has been obtained by means of the air pump, both it and the ba- 
rometrical gauge are to be removed, and the other parts of the 
apparatus are inclosed in a small box or case, surmounted by the 
glass receiver. 

The advantages of time-keepers going in vacuo, the patentee 
©^serves, are, " The unusual pressure of the atmosphere will be 



Mn. Thdf)ias<m*6 Put&ntfor Umbrellas and Parasols, 1 6$ 

prevented ; for when the air is heavy, the vibrations of the ba- 
lance or pendulum are retarded ; when the air is light, they are 
accelerated ;, but by these inventions of time-keepers going in va- 
cua, the vibrations of the balance or pendulum 'will be more uni- 
form ; the sea air, damps, and dust, which are so injurious in 
rusting, corroding, and clogging the movements of time-keepers, 
are totally excluded. The oil in vacuo will also be preserved^ 
ii a more uniform fluid state, and not so lia^ble to be glutinous as 
when exposed to atmospheric influence. Great care should be 
tdkeu to have a good air- pump, so as to exhaust the air as much 
as possible ; for the more perfect the vacuum, the more correct 
will be tfee motion of the balance or pendulum. These inventions 
of tinae keepers to go in vacuo, and to be wound up in vacuo 
when required without admitting the external air, will be of great 
advantage in being applied to clocks and watches." 

Observations. — There will doubtless be an advantage in keeping 
tie works free from the contact with damp and other extraneous 
matters, but we think it is not equally clear, whether or not this 
advantage will be equivalent to the trouble and expense of oIj- 
taining it according to the proposed method.- The apparatus isr 
complicated, and several of its parts require to be made with .the 
greatest care, in order to render them air-tight. The first ex- 
pense of the apparatus, the attention necessary to keep it rn good 
order, as well as the diflliculties in using it to persons unaccus- 
tomed to things of this nature, will also be considerable. It may 
also be observed, that even if the patentee were correct in his es- 
timate of the naagnitude of the inconveniences which are avoided 
by his construction, it would be much better to fill the receiver 
containing the watch with nitrogen, then tjt) exhaust it, because 
there would be less chance of error from the intiusion of the com- 
mon air, in case of any accidAtal imperfection in the apparatus. 



Mrs. Phillts Bowm Tiiomasok's Patent for Umbrellas and Para- 
sols. Dated Aprils I8O9. — Repertory of Jrtsy No, 97; Second 
scenes, 

Mas. Thomason's invention is that of causing a part of the 
walking stick or cane, the umbrageous part, the stretchers, and 
other parts of the mechanism of the umbrella or parasol, to be 
concealed or hid by tubes made to slide conveniently upon each 
other, and which, when drawn to their greatest extent, cover the 
above mentioned parts. When the umbrella or paiasol jg j-g. 
quired to be expefflded, the tubes or cases are to be slided upon 
each other towards the ferule, which gives the stretchers {y^ li- 
berty to act and expand the umbrella or parasol. The< oyect of 



l6A Mr, Schnudt*s Parent for a Phantasmagorie Chnmomeleti 

this invention, tlrerefore, is to conceal the umbrella or paraiol utiT- 
der the appearance of a walking stick or cane, when it is not re- 
quired to be used. These tdbes are to be made of any kind of me- 
tal, wood, ivory, or iuiy other substance that may be proper fot 
the purpose. 

Ohervafions.'-^lf the superiority in point of pnrtableness, which^ 
th^se umbrellas appear to possess, were compatible with a suffl- 
ent degree of strength and durability, they would probably be very 
extensively adopted. 



Mr. JoiiK Schmidt's Vatent for a Phantasmagorie Chronometer or 
^Nocturnal Dial, Dated Dectfnber ISOS.'^Repertory of Arts^ 

No, 97 y SccojkI Senes» 

The exterior part of this apparatus consists of a vase or orna- 
mental case of any suitable materials, so constructed as to allow* 
a free communication of the air, yet to prevent the rays of light 
from being visible, and having on one side a. watch with two' 
dials, and on the other a glass or a combination of glasses fixed 
in a, sliding tube. The diameter of this glass is an inch and three 
4)uarterB, and the pins two inches and three quarters; its use 15 
to represent tht nocturnal dial against the whII. A lamp i? 
placed in the bottom of the vase, in such a manner as to be 
capable of being either taken out or of having its position altered 
with respect to the magnifier of the dial. The exterior diat 
plate of the watch fixed in the side of the vase, is that of a 
common time-piece ; but the inner one is made concave instead 
of convex, and, as well as the hands, consists of any kind of 
polished metal. Upon this plate the numbers representing the 
hours are engraved in a reverse manner. It is a little inclinedf 
towards the light and acts as a reflector to the light of the larnp^^ 
which renders it visible against the wall. This reflector or dial 
is supported by an arm fixed upon one of the plites of the vratclK 
A steel centre is fixed upon the cock, and carries two cylinders' 
to which the hands, and the minute and hour wheels are attached:- 
these wheels are double, namely, one on each side of ihe body 
of the watch, and made to act in union with each other by a». 
wheel and pinion. 

Tlie mysterioi^s circulator, which the patentee states may- 
be applied instead of the watch work above described^ or may be' 
used as a separate time piece, or as an orrery/ Consists of the 
work of a horizontal or vertical watch, fixed in a*l>Ox oi; globe re-' 
presenting the earth. A weight is attached to the. hour hand 
wheel, and the box with the watch aitd weight are fixed, to one 
end of a lever, through Which a 9^el axis passes. The other 



Wr. Le Caan*s Patent i& check the Action of Carriages. IbS 

.ttid of the lever carries a box with a ^ufficieDt quantity of lead, 
to counterbalance the watch io every position whcnJn motion, 
and which is to be adjusted l?y trials, as difierent timepieces^ 
require different weights. The wboje of this apparatus resti"^ 
np'^n t^o jewelled fe.upp<»rters or fricti/)n rollers^ screwed upon ^ 
?tan(?, ujnm which is ^Iso fastened tVe support for'the rim, wl)icU 
serves as a djaf upon which the hours anci mmutes are desciibed; 
This rim maV ^e divided into 12 or 24 parts aecordipg to tlife[ 
constrnctiori of the time piece ; tlie 'hours and' miputes* are sbowii* 
by one feand or.U^ or inskad of vvh^ch a* nonius' may be applied tO' 
subdivide the minutes. ' ' '' ' ' ' 

' When this aj)|)aratus is to be used as a nocturnal dial, the 
r^€ector above described is fixed lo t^e sfcel centre, and cbliBTiei^ 
withjp ^hc prnameataj c^se thtj^f ontaip^ the larnj^ an^ 4i>agaififtitj^ 
the hand showing Uijb ^lours is ^ikewi^e ^jved within ,tbe case. 
Mr. Schmidt Las also invented a^j ypp^^ratys, to be fixed ^. the b^ck 
©f the box containing the watch work, for ' representing the in- 
crease and decrease, as well .as the regular reyolution of the moon 
^>':nd tfie'carth :" This motion is effected by a small weight being 
iixed to the axis Cf a pinion with 'six teeth, acfing into a wheel 
with sa teeth. The axis of this last carries another pinion the' 
teeth of which ,act upon a second wheel of 30 teeth, upon the 
axis of which the bent arm that supports the mooii is'fixed. Tnia 
apparatus, turning round with the box or globie po which it is 

attached, causes thr wheel which supports the moon tiiQOve pne 
tooth every day, ^ •/..... . . a , . >. # 

<^crcatwrjft.'^\Ve are persuaded tbat all who read this apecK 
fication with attention, will discover ihuch rno;e ingenuity than 
trtility in the inventit^n which it records; and be inclined rather 
to bestow upon it their approbation than favour it witb their 
patronage. *' ' • ' 



" '■ W — '■ ' M m 



BLWy^'ir-'TB ICgBggEaBgBBI^BgiBgBgMgiP^ 



^ Mr. CjiARtf.s Le Caan's Pxitent for an Apparafui to duck thi 
Actim of Carnages. Dated Februki-^, ^U<fi Hfpertdry of Arts. 
J^o. 97 y Second Series. ' ' ^ T "^ * 

This invention siijiiply consists in a bolt of imn ^xed to thu un- 
te- side of the axletree of the ca rr^age capable of being b1 ided against 
the nave of the wheel when it is required to stop itfrnotionf And 
In order to effect this, two rings of cast iron are fastened to the 
Iv'"'';'^ • *!^.*'^'^*'" projections or raised parts, against whicb 
. the bolt IS driven when it is intended to lock the wheel of the 
carriage. One of these rings is let into th« nave of the wheel 
to steady and hold the other ^ght when the bolt* is driw 



gainst it. 



* * ; 



l6S Mr, De Roche'i Patent for Jm^rwcments in BrewAfg^i 

06scrrff/M?i?5-— ;-ThiB inventiop^ peems to be. o^ne that niay ihave 
been .thought of by many persons previous to'!\Ir, LaCaan, but 
given up in consequence ot' the disproportion which necessarily 
tubsibts between the radius of the a^cletree or ev^en of the nave, 
and that of the wheel. This ratio is frequently as great as that 
<>f JOlb 1 ; and»therefore" the resistance occasioned by the friction 
a the surface of the wheel will evidently be 10 times a$ great as at 
tie bolt. Hence when the friction of the slidiog wheel is'^onsider* 
fcble, either from the weight of the load br the nuiurc of the 
ground, the axletree will be liable to injury from the operation 
of buch a force exerted on the bolt. 



I 



'7_ ■ ' ■ ■ .. » ,. 1,.^ . .. .. I,. I ■iiii^ii 



t« • 



Mr. Ranpolfh TsCHrrFELi db Rocnvs'^ Pate fit for intprwe- 
' ments *in th^ processes of Bre-xing.^ Dated September, iSup, 
Repertory of A* is, No. 9^, Second Serits. ' 

The skins of pale dried malt are separated from it, and roasted 
to a coffee colour. 42 lbs. of these skins by roasting are reduced 
to about SI lbs. and will give a very fine colour to a quarter of 
^It brewed into pprter; a smaller qnatitity oi roasted skins 
give a paler colour, ' 

:' The roasted skins may either be mixed with the ground roalt 
before it is bre\ved,'or they may be infused or boikd m the water 
ind the liquid hltered, before il is used ; or tbej^ may be moistene<t 
with water, and put into heer already brewed^ whi^l^ tjbey will ai 
the game time clarify. . ... 

Vinegar is to be made from ground malt, from.. which the skins 
bave been previously separated : this vinegar will contain less 
Essential oil than a.t present, because this oil resides in.theacro<» 
spire ; this is taken away with the skins. 

Malt wine will "possess the same advantage, and the spirit 
distilled from wash brewed in this manner will be 'more neutral 

or clinf er than -at presMit-;- - -^ '> « < 

.The great difficulty is to prevent the ground malt from clotting 
together; the a^ditioa of the roaete^ husks, or of the radicles di« 
/nipishes tl^f adl^esion ; o|r the gr^tiind malt may be sifted into 
the water, ' ' • . . . . i 



Ob^erxations,''— The usu^\ method of colouring brown beer, when 
jts colour is required to be deeper than can be communicated by 
fijgh drying a portion of the malt, h hy means ot "burnt sugar, 
j^ltbough the method proposed by Nir. de Rqche may at 4*"^^ 
Bight appear cheaper, yet as his colour does not contain any fer? 
inentisscfble substance, we apprehQOCJ a larger proportion of tpalV 
inust be vised to produce a beer of equal sireng^h ; and the diffi* 
cntty oir madhing a farinaceuus powder will be a coosiikrablf 
drawback* ^ 






< t$7 ■)• 



Ja/-. John Fkederick Archbold's Patent for a metft^d f^ cmm 
terliiig salt or aa wifter into fresh water ^ Dated Afrili 18u9w 
. Repertory (f ArU^ No, gi, Second Series^ . . ...... 

. Tiie stiU is biing in a water bath etit of which 'there is no' 
egress except hy a safety valve, by which means a stronger, degree 
of heat can be cornuiuniicated to. the s.till, and kept up hy a small - 
jSre. T1i% bottom of l\\t water bath ' may have a flue^ whicfa;" 
imaking ^om^ .horizontal revolutions may pi^ss out into the ^ 
chimney ; the back of the fireplace may also he a rtarroty boUe^^ ' 
or if on shipboard, the chimney of the ^replace may be made to V 
^sstbrotigh a vessel uptm the dee k, in order to supply warm 
livater, hy iDenns of pipes and cocks, to \ht still aiid bath. From'- 
the fleck of xh^ still, pipes are plated conducting the sieaxb int6 ' 
the cooking vessel*. 

• • The range has two stidingdoors which cover the whole of it$ 
front, and slide forwards being supp<»rted by bolts ruiiping in ' 
v^ bt^ples 6x^ to the sides of ihe fireplace; so that these dibors ' 
either sliut up the fireplace entirely^ or serve as a screen when iC is 
iiied for toisting^ ^ 

The steam tube may pAss througjh the si^ of Xhe ship, and 
alon^ the outside, and then be brought in again, to ilischiirge the 
condensed water ihtb the i-eceiver, ..,..' 

Whed the sea water is distilled, it is passed through a tlUieV^ 
thus made« A cylinder of tin, oi other metal, is filled with 
pounded charcoal^ and cjpsed at ^acii end by a perforated cover* 
One end of thie cas^ is inserted into a cask also partly filled wit£i ' 
pounded charcoal, and thus the water being poured iiito ihe cask 
fitters through tl^ case. 

Ohservatioits — ^Tliis apparatus for distilling water by the inter- 
iiiedium c»f a water bath niust of necessity waste more fuel thaii 
if. the heat were applied immediately to the distiHing vessel. 

JV/r. CiiARtrs VAL^NTiWi's PatetUjor a new wodt ^f ornaments 
ing and. painting all kindle of japanned aud varnished xvarct. 
Dated Mar'ck, ISO^. Repertory o/ Arts^ Nk 56, Second 
Stries, 

, Tub design which it is intended to trahsftr being ehgr^Ved'ijipoxi 
four copper.plates, the sti^origest lights on the phite No. 1. arid ' 
•o' do sbceessively ttritil the darkest shades are engraved' upoia ' 
No; 4. Fine fan tissue or othei* soft paper is next prepared hf ' 
striking a brittle tool over ii with a very strorig sdlutiott of gnm 



/ 






1 08 Mr. Vakntme^s Patent fsr Ornamenting Japanned Tfarts, SfK 

Arabic, isinglass, of similar substaoce, in the proportion of aboat 
k pound to a quart of water. 

; The plate No. 4 is then charged with Frankfort black mixed 
iip ^ith burnt h'nseed oil, and the darkest shade printed up6n the 
prepared pstper rather wet; . The next pla[te is then charged with 
the black \o which some flake white has been a(kied, and an im-> 
pression taken otf oh the already printed paper.- The back of the 
pxint is then damped with a moist spunge,' and the plate No. 2 
being charged with black to which a greater proportion of Aake 
white hati been added, another impression is tak.eu. Lastly, the 
oeepest iigh,ts are put in by charging plate No. I with flake 
xvhite only, and passing the paper again through the press ; the 
print is then left to dry thoroughly. 

After this the back ground i^ to be mixed with (ropal var- 
pish, and the whole of the shadows covered ArVith it evenly^ the 
whole being left to harden for a day or two. The wm)d,« nietal,' 
paper, or composition that is to receive tl>e impicssion is covered 
Tifith a thin coat of copal vami^, and when it is so dry, that the 
iipger wilLleave.a faint impression on the varnish, the prepared 
impression is applied upon it| and gently' pres^sed down with a 
Sponge filled with warm water ; keep the paper wet nntil the gumi 
is dissolved, and then the paper may be easily washed away, and 
when dry the waresr may be varnidhed and stoved as usual. / 

^ . Other colours may be grouad with oilj and used in the sam^ 
manner. 

If only a plain impression is required, the fan paper niay be 
prepared with a weak solution of gum Arabic, of about a quarter 
of a pound to a quart of water, and.an in^pr^ssion-^being taken 
upon it, the printed side may be applied while wet to the varnishedi 
surface of the substance prepared to receite it, and gently pressed 
down with a moist sponge. After a few miuutes, the papei* aiay 
be puVed off, and the impression will be left clear. 

. When strokes are required to appear in jjold ODon any painted 
sijrfacei it must first be gilded, and secured with copal varnish 
left to dry quite h^rd. Then cover it with a Second cdut of*vai'uish, 
$tnd when half dry, the impression taken o.T with printing iiik to 
w^ich some virgin's wax has been added, is transfeired upon it as 
just mentioned. This is then covered with the ground colour mixed 
with varnish, and left to dry in the air. The substance beihg therf ' 
"warmed, and irubbed with cotton, the heat will liquify the ink and 
wax, and thus the ground colour may be rubbed off, so that the gold 
will be laid bare. Wood cuts are best adapted for this purpose. 

, Engraved blocks may also be charged with gold size, and 
printed upon the prepared paper, and by a moist sponge trans^ . 
ferred upon any varnished body; when rather dry, the impression 
iniay be gilt or bronzed. ) 



.. - Mr.. W'nrhurtonh F^€^tfor Detiot^UtnJf China\ ^a ' 16^ 

.. Obsec^aiions.-'^Much iogenuity has been exercised in this 
Hi'ancb of manufacture in order to supercede the use of the penci}^ 
by stencilliag, caulking^ and prints fordied of small pieces of cork 
or other elastic substance, but these improven>ents have not pro< 
duced the full effect that was desired, as they did not traasfer^a 
' painted or gilded surface upon japan wares. 
. Mady attempts have indeed been made to produce the efiect of 
painting by means uf.mea^sotinto printsl l*h^e were sometimes 
applied in a way simihir to those on glass, by steeping them in 
\^rm water, and care/uUy rubbing the pa{»er from it, bat the 
enect was not equal to the trouble. Sometimes the printed paper- 
itself was cemented to tbe jitpan wates,'but tlien thesb could not 
be stoved in a suflicient heat to ensure their durability and 
hardness without cockling the papev. 

On the^ plan proposed by Mr* Valentine, and called by hini 
poHzographic, the paper is caRen uway in an instant, and all the 
colour discharged upon tbe wates< And although the process 
may appear rutber tedious from the number of plates made use 
ot, yet the effect which is produced, and which is nearly equal to 
that of thti pencili amply repays the trouble. 

VVaiuscoitings, walls, and ceilings of drawing rooms may thus 
be ornamented in an elegant and expeditious manner. The prints 
fiiay be u&ed the moment the back ground is dry^ or if they ar« 
kept from the air, they may be applied with equal succesb many 
mouths afterwards, and the paper taken away by the use of a wet 
sponge, 'i he transferred painting itself^ A^^y^ when dry, be var« 
hished and polished, so that its U'ue lustre and beauty will be 
preserved for many ^ears4 



Mr, pETtrt WAiiBtJAtON*s Patent for decorating ch'ma* porcelain^ 
carthniwahe and glass, with goid, silver, plaiina, or other metals. 
Dated FcbhUari/y ISIO. Repertory of Arts, No, i)d, Second 
Series. 

TuiiRi methods are he re ^proposed. The first is, to fill an 
engraved copper plate with oil, and print it upon a substance 
composed of glue and isinglass; called by potters and printers a 
batt ; this impression' iis then 'transferred to the earthen ware or 
glass by pressure, and powdered gold, silver, oi^ piatina is laid . 
Upon it, which adheres only to the impression. 

In the second method^ the design is printed in oil upon sized 
potters' paper, and transferred to the ware by means of flannel,' 
w] other substance fitted for the purpose : the powdered metals 
aie then laid on it. 

The third is, to mix tbe powdered in^tals with oil, and after 
mUng an engraved copper plate v/ithtbe mixture, to take tbe im<- i 
{>res8ion upon si£ed potters' paper, and then tr49sfer. it tg XhP r 



// 



i*70: Messrs. Marshail and HayUr^s Pe^ifor' frtMufaAurtTi^ Sattl 

ware h^ means o^ a rubben The paper is (hen taken off, leaviri^ 
the impression irpnn the ware. 

The oils, batts, and powdered Tnelnls, Birt prepared by thi? uBoal 
nethnds. wbiich are wfell knmvn in the trade. 

Gold atid silver are best done in the first and sebond method, 
for plaiiuH the third is best. Tbenl'etals are to be printed upon- 
tbe glaze «f ibeeartben ware, and aT$ bnrnlid or buvnjsbed in ihe 
(ftnie manner afa if they were l^id on with a pencil. 

OhstTxatiws* All these methods seeiA to bfe'wefll adapted 16' 
the purpose. 

I 

Messrs. JoiiW Ma Rill AH, 0nd John NAYLmV Patent Jor ma* 
nufacturing and mnkinfr salt, Huteri February h lSOt>i Jtfper* 
tory of Arts ^ No. 9?, Second Series* 

Im the common method bf evaporating the brine, the fire ha^ 
access to the entire bottom of the boiler, btrt these patehtees 
, propose to heat only wne or more spots of the boiler, and there- 
fore, as tl*e other parts are not expos<td to fire, they may be mads 
in the, form of shallow ponds of clay lined with tiles, or other 
cheap materials; The circulation of the liquor })roduced by ebul- 
lition will heat these places, and the ^a)t vlil be fornitfd into crys- 
tals chiefly in tbe coolers or cond* nsiprs, as they denOriiinate the 
parts not immediately heated by ti^e (ire. 

OhservattQns. -^^The idea of having only otie part of a boiler 
made proper for the immediate application of the lire. ^n<i forming 
ahe other of cheaper muterials is a very old one.' (Uauber in bis 
Philosophical furnaces, published nearly two cetitttries ago, ap* 
'|»lied it to dislill^tion, uaing a barrel for the body of the still,' 
hen ted by a hollow iron pear c<immunicatihg with the bottom of 
the barrel; and for warm bathi* by a similar contiivance : froni 
this arose the common propositioti of boiling meat by one 
end ot' a guu barrel being inserted into the bStis'o'f the grate^' 
and the othe# into a barrel of water standing before the f/re ; an 
e?cperit1nent in which ,many wiseacres have failed" for want of 
knowing that the gun barrel should Slant iipwards and be insertecf 
tiaaLV tbe bo^ttom ol the cask. Werecolh»tt a stilk nearer approach 
to* the present boilers' havihg been proposed for field breweries to 
' follow an army, ih which the sathe wide wOodeh tub* was to serve 
tis boiler, mash tub^ and cooler, a small part drily of its bottom' 
bedng mad<; M' eoppei^ and intended to be^placed over a temporary 
£te place. 

It is doiibtful> whether the alternate heating anti cooHng of the 
^rine will be favourable to the production of the salt considered " 
>rjfya;xesp4(Ct'l9'ih« qaaiitiiy of «Jue2 that tntest be nseof; • 



{ m > 



ii;.ii',i'., I . ..,■ 



• 
Q»..9 new Jiind,of JFufihn^ tehich twplaias^t he Formation of litApid 

^l^.fir^t Qnly-thoterjDiiuerals • that bore ev'.deut marks ofthftif 
ig{ieop9 <>rigiov j9i:^h »s Abfiidian, scariie, ^nd pttorice 6tob«f yr^pe 
i^\$n}etf^^e4.ii» vok^aic pffoduoi^, • DeHinarest iii%t armnged th(r 
V!BL§^UiUfjAuvergn«,»iiKnig.ti!«9e products ; but it was principally 
Fjiujas ititnd Ddi^miett ..«hn detcrniitied cnncernnig cbeprodoctU^n 
o( ^be^pMxifirak c«Utd-iby Dolotnieu,xom pact lava, -siDcd known by 
ibe pan^ <if Irtboid iuva* -i be. me re adduion of tim lava to tb« 
lis^ f)f ycdcanic lub^aacHS, ifl not Xh^ oivly discovery of con«fc* 
^.u^iK^, for alihadgrb it Jiiail^undf jigone an o|»«rat.(>ri which is usti« 
«|ly condifleftd AS beingt>f a disorgafiisiaf nature, it y^t cotit&ina 
Vttbst^oces is th^. aame^sftatej and in ihe same disposition, as what 
i^e contaified in tba xocka frovi whence it uas f;>rin^d. \Vh«nc« 
U i^^caame.an objectof ioqaiffy .to determine how the substance^ 
tbflit formed tbe isasis.osf ibi& lava .were fnsed» anil yeu their tsu>tvy 
ftppfMwrance rc4aiued;> and Ailsoto iix »poH ihe iiine ^hen ihecrys^ 
tak enclesed in porpkyxiiic lava w^re furlned. * * 

Sijiesttce and Dolomatu endeavoured t<» discover a kind of fa^ 
si4n>^ia which the matter shouid not^lx^rfkiiiccid to'<gla«s or 8Cort% 
but in vain. .J^pailansaaiii was eqaally tinsuccesstul. Ddtomieti 
bOMKever, Was con^^inced irom bis observations, that earthy S4ib« 
$|aoces. suiffrred in the deep lecesses oi the globe, froin some par* 
iicuiar application of caloric, a kind oi fusion in which ihe sub* 
stance act«d a|>on was only, disaggregated, but not ailered, and hft 
iilso thought that the crystals tound in lithoid lava, preexisted* iit 
it before its lit^efaetion. Ihis latte^ opinion tbund but f«w siip* 
|)or.ters» ' * 

• To obtain the proofs of this hypothesis, it was intended to en- 
close pieces of roxk io^bedded in powder of the same, in crucibles^ 
to cover the mass with quartz powdttrtd, or other infusible subJ 
stance, and ta expose the crucibles to a long continued, but mo. 
derate beat. ihe. expentnents were already began, when Sii^ 
3ames Hall's essay on the efiects of heat ni(»diried by Confipi ession; 
appeared; upon reading which, it vyas determined to make use of 
the lights furnished by his experiments, in endeavouring to bring 
tocktf to a kind of fusion, Biunlat to that by which litboid lav^ 
was formed. 

An opfMJsite opinion, which altrtbuted the formation of Hth'nid 
lava,, to (ievitritication, gained giound in the mean time; beifl^ 
supported by Sir Jame* Hall, Dai tigue^, b'leurijiu de iieJleviie, 
fvnd Gregory Watts, in this system it was supoo^ed that hthoid 
hkVH, arose from the gradual coolmg oi vitreous lava, or obsidfan : 
thus entirely depaitiuu urom the system of Polumidii, who held 






i 



|72 Mr. De Dree <m ike Fvmiation rfUtkoid Lscti* 

obsid^.an to be the produce of lithoid lava, whicb, on arriving k% 
tlrt^ crater, and coining in contact with atmospheric air, defla- 
grate^, and becan)e vitrified. 

In order to determine whether lithoid lava was produced by' ft 
particular kind of igneous fusion different from vitrificatioli, or 
by devitrificatioiu the following experimenti tyere made on the 
rocks. which appear to be the original matter of lava, and pAfti* 
cnlarly on two kinds of porphyry, one with a ground oi trap, tb4 
' other of petrosilex. The pieces of rook were^put into a poreelatn 
case, or llessian crucible, imbedded in, and eort«red with'fhe pow« 
der of the same rock, rammed as close as possible. T^hvip^wder 
was then covered with a dake of niica, and the remak^der of the 
vessel filled up with fine quartz sand; .Tbe porcelain cases were 
then closed with stoppers luted by a very fusible glass, and pvj; 
into a compressing apparatus. The crucibles were placed in- 
other crucibles filled with fine quartz aand, and the cover luted hhi 
with clay, and bound with iron, wine* P^rPonveCers were^Wi^tbin 
tlie ipside of the cases or crucibles, except in the two first* expeJ 
riments. The compressing apparatus wfts at first intended-tb' 
prevent the escape of any gaisfous .fluids or to^ pt)e««ii\ aociMk/nft^; 
but as it was found that very little gaseoua matter was e^mtainc'd 
14^ the substances operated Hpoo, the apparatus was sinopMed, 
and as no experiments are here rtelatied,. which ure afi«ctbd.l^. 
f^ompression, it is usi^lesa to describe the Ap para tcm. ^ 

J, Greei* porphyry from Glromanv with crystals of greeilish 
white felspar was exposed for 42 huurs, t6 a heat of about *lb d. 
}kVedgvv. (as the pyrometers which were mrt placed in the hotiesf 
pai-t indicated 14 d ;) the powdered stone was changed into a 
bjack scoria, but the entire piece was net melted. 

^. .Gray petrosijiceojus (felspathous) porphyry with iniletermi-* 
nate crystals of white felspar, and grains of quartz, from the Py- 
renees, was exposed to the same heat, at the same tiipe ; tbc 
powder was only agglutinated, the whole piece was scarcely al-* 
tered. 

3. Serpentine porphyry, exposed for 18 hours, to a heat of 4 
or 46 d., was melted into glass, except the included crystals of 
felspar and quartz* ''^ 

4. Pyreueai) porphyry, same as No. 2, yielded a similar result. 
" 5. Serpentine porphyry, same as No. 3, was melted into black 
glass, except the felspar crystals, which were still lamellar, and 
had not changed their form. 

6. Another variety of serpentine porphyry, was perfectly liqui* 
fwd, botl^the powder and entire piece. 

8. Serpentine porphyry, same as No. 3, was exposed for 25 hours; 
to a heat of 40 to 42 d. ; the powder was melted, and formed a 
kind of&coria, not vitreous; the piece had been softened without 
iieipg melted, and appeared like aemivitrified por^elaip^ 



AQr. De Dree on the Formation ofiithtnd Iavo. If 5 

• 5- porphyry, same as No, 2 , with 1.1 grains of common salt^ 
iiiid 6q of 8ul)»hur .mixed wi^h the powder, was exposed as No. 8; 
the licjuified .{>owder iiad the ap{>earance of jporcellanite lava; the 
piece had been only softened. 

i I. Green porphyry, same as No. ,6, in powder only, and takea 
luddenly from Jthe iire, had become brick red, and was scarcely 
agglutinated, except at the boitqiu, vvbere it was.bl^k. 

12. 3 02. 4* dr. of the s^me porphyry, in powder only, and mixe^ 
with 9 grains of common salt, was exposed as the three forego- 
ing ; and acquired th^e desired degree of liquefaction as the result 
perfectly resembled lava. 

i4. Another variety of serpentine porphyry, containing nodules 
fi£ quartz surrounded with pyrites, was exposed for 36 hours to a 
heat of 5f) d. ; the powder was melted^ and also the upper part of 
the piece, where the powder had become a scoria. 

17. Si-me porphyry as No. 14, was exposed to the heat of a 
forge, about H2 to 133 d., for ^ haurs and a half ; the' large piece 
was entirely melted^ and changed into a stone, in which the cry? 
stals of felspar preserved their lainell^r jtissue. 

19. Granite of Chamouni was oielted in the forge, but the 
felspar and n^ica still retained their granitic disposition. . 

21. Same porphyry as No. J 4, inclosed in junbaked porcelain, 
was melted in the forge into glass, and run through thje numerous * 
cracks of the vessel, 

23. Same porphyry as No. 6, was melted in the forge, and 
partly run through the cracked vessel > the felspar was melted af 
well as the ground. 

2^ Same porphyry as No. $,. gave the s^jx^e prodnc;t si» No. 21, 
although taken on t b,efore it was cooled. 

25. Same porphyry as No. 14, previously dried at a red heat, 
wa^ exposed in unbaked porcelain t,o a heat of about $0 d. in a 
porcelain furnace, for nearly 6 hours.^ the powder was liquefied 
and consolidated into the lithoid state, but thie entire piece wa$ 
.only softened, anii had a porcellanous appearance. 

26 Hornblendic rock, imbedded in previously ignited powder 
of quartZy in the same heat, were liquciied ; som^e had run out of 
the cracked vessel, what remainfd i^ the crucible was lithoid 
Hi^here it was thick, hut res«mbl)?d scoria* where it was thin. 

Several substances exposed in the porcelain furnace at Sevres. 
in double crucibles, were completely vitritied ; the heat inde^a 
wa 110 d. 

33. Pyrenean porphyry* same as Ifo. 2, yielded in the above 
furnace, perfect pbsidiaji, th^ crystals of qii^artz remaining m^- 
jnelted. 

57- A large mass of fissile uorphyritic rock with ' mica, im- 
l^edded in powder of the same, m a crucible inclosed in another 
ipf caist iron, the interstices being filled with sand; which covered 

N9. 24.— .Vol, vu 2 a 



17*6 Mr. Jbe tine dn ike PormHtion of lUioid iMtd. 

taK This incipient crystallizBktiDii produced by the igtieonii h* 
ftion IB perfectly distinct from the devitrilicatioo which succeedt 
Id the titreous fusion, fbr the iirst ' is, as has been just said, a 
ttier^ approximation of similar moleeules which have tiot ceased 
^o exist ic the liquefied matter; the second is a new 'formation 
cf substances- produced in the vitrified substance, all the parts of 
which have beeu entirely cningWd together^ so that the new com- 
pound never, resemblt^s ttbe origioal matter as it was before 
fusion. 
. The iithoid i^vas are.tho^ produced by the igneons ItqueEfaction 
pra^^e/d by the he/at dit«|ig«^e4 l^y chemical. actions in the inte.' 
rior of the earth, and communicated without combustion^ as al&9> 
hy the caaipr<ession effected by the etormoos superiucnnbrnft 
weight. The half meltni state of the interior of the earth, pro- 
posed by Dplomieo^ is favourable to this hypothesis. The crys* 
tals of felspar included in poi:ph>^ry are not altered- by the igneoitts 
liquefaction of their ground, although that ground is . itself fel<< 
Spathop;^^ they even resist the action of vitrification unless the 
temperature is carried to a very great height. Whence it appears* 
that the felspar, anaphigftne (leucite), pyroxerre (augiteX fttni other 
volcanic gems, preexisted ip the lava before its fusion ^ but some 
Crystals found in certain lithoid lavas must be excepted, as they^ 
may have been formed by the abovementioned incipient crystaW 
)i£ation. > I'hey may be kr>f!wn by certain peculiar characters^ 
but the diffei'ence is not alivtfays easy to be discovered. 
. At present the consequences of these experiments are coefincdf 
to the fe»planatioR of the formation of lithoid lavas^ and the pre- 
existence of the crystals found in lava ; but as lava itself ba9 
considerable resembilancte to thet original rocks,, they might be ex« 
|ended to primitive substanqes ; further experiments and obser^ 
i^atioBS .are howevj^r wanting. . 

Sir James Hall^ who commenced^ bis experiments with calca* 
reous spar, has made uae ^i them to confirm the geological 
theory of Dr. Hutton, by, means of suppositions which he cotw 
ceives t0 be possible. - It i^ astonishing that be has not distinctly 
mentioned whether his results a«o$e from igneous liquefaction or 
devitrification ; it is, however, most probable that (he lattei* is hi9 
opinion, as it aigrees better wUh his vef^&rks on. the fusion of whin.* 
stone in the Kdio* Trans, for 1799* But it &^em» more likely 
that the. change of powdered chalk ipto '.gfanttlar marble was 
]iy igneous liquefaction, than that the chalk was iirsi vitcifisd^ 
and then reduced to a hthoid state. 



•«iW 



Observatiansj^^An accoaal; of the expl^nmenti of Sir Jamer 
Halli which paved the way for the above curious facts, was given 
in our second volume, p. ^65 ; the present experiments are stitir 
PM^ important as they seem lio shew that this kind-of JHOipie&t 



Mr. Httuy on Arragomte. 177 

'iksi0a UdLfs place at a iowe;^ temperature tliati has been hitherto^ 
supposed, and does not in lao&t casea require that compression 
which had been c6iueived to be necessary. They aUo point out 
the mode by which the experiments may be advantageously ex- 
tended by persons who have at command furnaces in which a 
moderate but long continued beat is kept up, as the necessary 
apparatus is reduced to such simplicity as not to occasion any 
great expence. To them, therefore, we recommend the prose- 
cution of the inquiry, which is of the utmost consequence in 
geology. 

■w^ga^ttggggBB W i ll i I msasBsasB% ■ i i .ji. iii F"WTfmTi iBaeg 

On jirragonite. By Mr. Hauy. — Jomm. des Mines, Ko, 136.^ 

The arragonitc is distinguishable from calcareous spar by its 
hardness being very superior, and its specifii: gravity 2'9 instead 
of ^'7i a^s also by its internal lustre, which is superior to that of 
calcareous spar and approaches to timt of the diamond. Its 
crystalhne forms are, as is well known, tery diiTerent from those 
of calcareous spar ; audit exhibits only a single image of an 
object m the same circumstancejs as calcareous spar exhibits a 
double image ; and lastly, when arragonite i« exposed to the 
llame of a wax taper, it is converted almost immediately' mto a 
wt^ile powder, which is tbrown around the tlanac, by a kind of 
cxplosi«)n, while caleareous spar remains unaltered, and preserves 
its transparency for a long time. The imperfect varieties of 
these, two substances do nut, however^ exhibit such striking diffe- 
rences. 

The concretions called flos ferri are probably varieties of arra- 
gonite, as is also the hard carbonate of lime, described by Bour- 
lioti as a distinct species, the primitive form of which he sup.^ 
posed to be a rhomboid of 128® and 64** ; but bard carbonate 
has been divided in the direction of the diagonal of the prism of 
128^, so that the angle appears to be an union of two angles of 
64f° each, and thus its primitive form is shewn to be the same 
i;eith that of tlie arragonite. 

The soitnes of satin spar and its not being much altered by the 
Aaxno.of a taper^ ^eetn to shew that it is a tariety of Ihe cotaoion 
earbooate oi lime. 

. if 

OhservatiffnSi^^Tht differeiKes which are to be remarked be* 
fweeti calcare<jus spar, and arragonite, fiotw ill. standing the iden-^ 
tity of their composition, as determined by the most able che- 
mists, are so strikiug, that they cannot be considered in any 
^ther light than as separate species. Hitherto arragonite ba» 
been the oidy mineral which presented an anonialy in its crystal, 
lisfttioe^ bui Qt tate anaXase w oisaoite has beeo^ found to have m 



178 Mr, Hassenf/atz on pofiushcH Irdn» 

different primitive form of its crystals from that of titan6 Oxide 
or rutiie, although their composition is similar. 



On Dusodiie, a new mineral .^nics, Rij Mr. ^01) Is Cordieu. — 

Jouni. dcs Mines, No, \%. 

This substance was found by D6lomieu, in Sicily, and brought 
to Paris about ten years ago. 

It i? compact, and found in ii regular masses which split with 
the greatest ease into very thin leaves, which are very brittle, al- 
tiiough slightly ^exihic. Its specific gravity is J*146. It is 
easily cut. Its colour is gie^^nish gray, ^)r yeHowish gray ; 
it is opake ; and it has a clayey smtll wheii niciisteiied by the 
breath. 

It easily takes fire, and burns with a clear flame, and an un* 
supportrible stench like that exhaled by fetid limestones on ri>b-^ 
bing ; a sirtall piece is sufficient to poison the air of a room for 
more thafi an hour* an earthy residuum of more ihan one third 
oi the original weight is lett. 

When it is soaked in water, the leaves separate, and become 
not only tranalucid, but also perfectly ftexiblei 

Dusodiie iies^ in a thin bed bttween two bedd of secondary 
I'miestonc, at Mellili, near Syracuse. It has been h>ng known in 
that country under tlie name of the foliated bituminous earth of 
JSlellili, or by that of devil's dting ; but both these names being 
improper,^ it may be called dusodiie, whose Greek 6tym^logy ex- 
presses the fetidiiy c( its smell when burning. 

Ohserratiom, — This bitu^minous substance most of course be 
arranged after the species, coal ; it probably contains some sul,- 
phuret, to which its horrid smell when on fue is owing. 



On potashed Iron. Bj/ Mr. Hassenfratz — Jouru. des Mines^ 

Ao. 13/). 

Gay-Lussac and 'Fhehard have decomposed potash b}^ mean^ 
of iron, and obtained alloys, which yield nitrate of potash when 
treated with nitric acid. Now as iron ores are usually smelted 
with charcoal which contains more or less potash, it is pfobable 
that the alkali is reduced in the operation, and combined witlf 
the iioB. Oak charcoal contains aoout 2 parts of salt in lOOO, 
beach 5, elm 20, aspin d, in 2. Qua medium', lOOO parts of 
charcoal contain 7 of salt, so that as 500 of charcoal ar« Usually 
employed to smelt 100 of iron, 2 or 3 per cent of the new metal 
ipav be combined witb the iron produced* 'i his sfmall ploportauri 



Mr. Hassenfratz on poiasked Iron* 179 

would not be of any consequence if it were not known that a 
very minute portion of phosphorus renders iron coldshort, and 
jninute portions of sulphur, or copper, redshort. 

Tlie influence of potassium upon Iron has been uncertain, be- 
cause the quantity of alloy , hitherto examined has been too 
^mall to be forged. When coldsliort iron is purified at Zinswiller 
(Lower Rhine) with lime and potash, it is rendered brittle if too 
great a proportion of these additions zre used. , 

To examine the alloy of potassium and iron by experiments 
made cpfr»n the ajloy itself, a gunbarrel was procured, in which 
the above chemists had frequently repeated their process for re- 
ducinj^ potash, and was still filled on the inside with pota^hed 
iron. This gunbarrel was examined by a sawmaker, Roza, wljo 
is usually employed to examine the specimens of iron and steel 
sent to the board of mines. 

The gunbarrel was heated, and flattened, in which operation a 
piece of superpotashed iron was detached whicli was coldshort, 
and when broke, seemed to consist of a mixture of a brown and 
white raatf'r ; the latter had a metallic appearance, and ham- 
mered easily, when it was separated from the brown substance. 
In 24f hours time, this small piece was covered with the moisture 
it had attracted from the air. 

.The flattenqd gunbarrel was well forged, and spread^as easily 
under the hammer as coldshort iron usually does ; it was bent 
several times backward and forward without the least crack, 

A small bar was bent several times in the cold, but at last it 
})roke. Externally thi§ bar was dead white, like platina ; when 
broke, it showed a white band with a very close grain which en- 
veloped a brown nucleus, quite distinct, and only slightly adhe- 
rent. I'his nucTcus was formed of white and 'brown grains 
formed from that part of the barrel that bad bden most exposed 
to the potash. The external iron was soft, and easily filed or 
bammered in. the cold. 

Another bar was heated to a cherry red and tempered ; the 
tempered surface was blistered like steel, the metal had become 
harder, but still preserved its njalleability, aii^did not crack till- 
it had been bent several times. When broke, it had the same 
appearance as before it was tempered. 

It is, therefore, probable, that iron combines with two propor- 
tions of potassium. One ad minimum, white like platina, easily 
worked vvhether hot or cold, more malleable than iron, acquiring 
hardness by tempering without becoming brittle as steel does; 
whence it should seem, that the potash contained in charcoal has 
a good effect up«n the iron which is smelted by its help. The 
other, ad maximum, is brown mixed with white points, the par. 
tides have but a slight cohesion, it is coldshort, and very pro- 
bably brittle wheq heated. 



}€0 hUssrt. Lussac aud Tkenatd on tke^mdah of Potash and Soda, 

It is not, however tp be supposed that the properties of th0 
alloy of potassium with iron can be rigorously determined by a 
single experiment; new experiments must be made in order tn 



determine the matter. 

5B* 



4 

On the nmtaU of Potash and Soda. By Meisra* Ga v Lussac, and 
Thenard. Journ, des Mifies, No, \^. 

Some parts of this notice were inserted in our last nnmber, 
p. 95» i^oya an extract published in the Annales de Chimie; 
yit therefore omit thos« parts u4jich we have already given. 

The quantity of hydrogen the metal of potash produces when 
it is treated with water is erroneously stated in the Annales. In 
the preseht pnper it is said that an iron tube was fiiled with 
2*284 grammes of the metal, covered with a plate ofglass, and 
thus introduced under a bell glass (jUed with water; aji soon as 
the metal touched the water it was thrown up against the glass 
hut no Hame appeared, and 648*92 centim. cubes of pure hy- 
drogen were emitted. 

The mi&tal of potash heated strongly with iron forms & soft 
alloy. It also unites with quic)i silver, as soon as it comes 
^ cont»ei therewith ; the consistence of th^ alloy varies accord- 
ing to the quantity nf th« quicksilver. Both these alloys de- 
compose ^ater'with more or less rapidity according to the greater 
or less quantity of the new metal. 

The oietal decomposes carbonic acid gas, and gaseous oxide of 
carbone, yielding chaitroal and potash without any gaseous re- 
siduum; nevertheless at a high ten^perature, the new metak can 
))e obtained from the alkalies by means ef charcoal, for white 
vapours are disengaged which have the same smell as the new 
pietal ; but as nothing could be obtained except an effervescent 
charcoal, it was concluded that the gaseous oxide of carbone de« 
stroyed the new metal as it grew cold. Mr. Curadau, however, 
has since shewn that the metal may be collected by presenting a 
cold substance tp the vapours. In this process, however, very 
iittle metal is obtained unless iron be added, or a gun barrel is 
used, and the metal itself is rendered impure by the charcoal. 
Manganese or sine might also be substituted for iron in the pr«. 
paration of the new metal. 

Four parts of metal of potash was heated with 5 of pure vitrified 
boracic acid in a copper tube. No gas was emitted, and the metal 
disappeared, being converted into an olive greenish gray sub- 
stance, which did not effervesce either with water or the acids. 
It contained borate of potash, with a great excess of alkali, and 
an olivt coloured substance not soluble in water. The boracic 
acid is probably decomposed in this operation. 



/ 

Mr. Havy on Apopkyinte, 181 

^Tien merrqrius dulcis was treated with phosphorus with 
mlent to obtain dry muriatic acid, a liquid conipound was 
jtrbtainedf strongly acid, colourless, and very limpid, which smoked 
hy contact of the air. Blotting paper moistened with it took 
fire of itself. This liquor grew thick in a few days, and deposiled 
phosphorus. When it was passed through an ignited tube coik 
iaiiiing iron, no other gas but a little uMiriatic acid was emittedi 
and much muriate and phosphuret of iron *were obtainec|. It is 
probable that tJiis compound may be formed by treating phos- 
phorus with oxymuriatic acid gas, and that this is the reason 
ihat phosphorus takes fire so well in that gas. 

'J he inetal of soda i^ prepared in the same wiiy as that of 
potash, and may be puriiied in the same manner. Its metallrc 
trilliancy is very great, and its colour between that ol lead and 
tin. It is ductile, and mav be kneaded like wax. It does not 
take fire in the air, at 10 or 15^ nor when tlung upon water; but 
it whirls about rapidly on the surface, becomes very hot, and 
is changed into soda, twice as^ much hvdrdgen being dibengaged 
as when the metal of potash is used. The metal of soda melts 
' at 50°, while that of potash melts at 58°; when the two metals 
are alloyed together tljey become more fusibje. Ihre* parts of 
soda metal, and one of that Irom potash melts at 0^, but becomes 
Jess fusible hy augmentinjg the proportion of the metal from soda, 
and more fusible in contrary circumstances, to a certain limit. 
The alloy of 10 parts of metal from potash, and 1 from soda is 
not only liquid at 0^, but it also swims upon naphtha. In all 
cases, if it melts at 0^, it becomes brittle wlien rendered solid by 
cooling. The properties of these alloys explain why these 
metals have been thought to be liquid when pure, unless it may 
he that this liquidity drpeuded upon the greater or less quantity 
of hydrogen that enters into the composition ol the metals of th« 
alkalies, whicti is not unlikelv, as Davy has ob,tain.ed by the pile, 
ii metal of potash fusible at 4^; 



Observation f.-'^The latter pctjc «.. mis essay points out several 
mistakes of Davy, in respect to the consistence of the metaU 
obtained from the alkalies. 



t '• ■ ■■ ■ m ,,r^tnt^rtr — mm m - " " "^M— W— — — — 1— i— — — ^^^^^^^^^ 



On Apophylliie. By Prof. R.J, IIauy. Journ.dts JUims, No. 137, 
It shghtly scratches fluate of lime, and very sensibly carbonate 
of lime. It is easily rendered electric by friction, and the elec. 
tricity is that called the vitreous. Besides its characteristic 
lustre it has a moderate degree of limpidity, without any peculiar 
colodr. 'I'he fracture is conchoidal, and moderately brilliant. 
No. 24.— TOL, yi. 2 p 



1 S2 Mr^ UHalhy^ on the Tofniatwns of Flint Slate. 

Observations, '^The remainder of tbis article is omitted, as it 
may be found in Lucas's Tableau dcs Especes Minerales. Tw^ 
analyses o/ this stone, under its other name of icbthyophthalroitey 
or hsh eye stone, may be found in our work. viz. vol. i. p. 376^ 
and vol. ii, p. 105. 



On the formations in tikich Flint Slate is found. By Mr, J. J. 
Omalius D'lLiLLOY. Journ. des AlineSy No, it>8. 

Flint slate, or keisel-schiefer of Werner, is found abundantly 
in the departments of the Ourthe, the Sartibre anci th** Meuse,and 
in that of Jemappe, in three different depositions, which, howeverj 
all appear to belong to a contemporary formation. 
*■' The most remarkable deposition is of kidneys imbedded in bito- 
miniterous limestone, in a manner similar to common flint in 
beds of chalk": but th^ kidneys are cerierally mere round masses, 
not tubefculated. The bituminoirs Timestone is usually covered 
with a l)td of clay containing numeroifs fragments of the preceding 
kidneys scattered through it, which seem to have been separated 
from the calcareous beds by sonie accident. 

In some of these kidneys the quartz veins which arc a strik- 
ing character of the variety of flint slate, called I.ydian stone, 
are disposed in concentric circles, as in some varieties of onyx. 
' Flint slate also forms beds, and is then muchrtiore slaty, so 
that it might at first be confounded with the black slate of coal 
mines; but it is distinguishable by its hardness, its unfusibility, 
and its not losing the black colour in the fire. The flint slate iii 
these beds is very apt to acquire a grosser texture, and by this 
means pass into the clay slate, or sandstone, which alternate witli 
the beds of bituminous limestone, so that it is only in detached 
places tlTat it preserved its proper characters in perfection. 

Flintslate seems to be a variety of quartz. Brongniart has de- 
scribed it under the name of '^lat}^ jasper, which appears very ap- 
^licabte to that forming beds. Mr. Detbier, however; has found 
in a quarry of black bituminous marble, kidneys of flint slate irf 
hexaedral prisons terminated by a six sided pyramid. Thts& 
crystals are the best formed in places where a mixture of clay 
and sand renders the limestone soft and coarse grained • They 
have the usual blackness and opacity, but their internal lustie is 
bi*illiant and glassy, in these they come near to the quartz hyalin 
of Hauy. So that in tact the same formation exhibits a series 
'which passes imperceptibly from flintslate (quartz jaspe) in beds, 
)iaviiig a dull aspect, through flint slate, (quartz agate) in kidneys? 
y{\i\i a brilliant fracture, to quartz hyalin with a glassy aspect. 



Mr. 1^Ut€r*i Experhntnts rdoiwe to Potash and Soda. 185 



Vji af-tjficial Fuzzotana, or tarras. Bj/ Mr,^ G rati en Lepere.* 

Juurn, de kliys. Apnl, 1 808. 

Ba<;g£, of ^Oottenburgh, first eippIoy«d calcined argillaceous 
Mones instead of tarras, ui the construction of tbelock^ on the ca- 
nal of Tralhatta in Sweden. Many experiments have been made 
in France, which show that slate cajcined, or other argillaceous 
stones, when burned^ may be employed .instead of tarras, or 
j>U22olana iit n^asonry under water, or for terracing the fii^ roofs 
of buildings, and that tbe money sent out of a state for the pur<^ 
chase of these commodities may of course be kept at home. 

• 

Obsa-vations. — This is but one of those numerous political essays 
which have lately appeared in France to encourage the use of 
native articles in preference to foreign ones. The subject, howr 
ever, is of some importance in the arts, and merits the attention 
of speculators, who will certainly find it advantageous to bring 
into the market, Engjlish tarriiS, at a low price. If, however, we 
recollect right, Morveau has shown in a memoir upon mortar, &c. 
(See Repertory of Arts, Ajc, vol. xv. p. 132.) That althougl^ 
these cements grow very hard in tbe air, they cannot be employed 
under w;iter,.an assertion which is entirely contradic^ry to wba£ 
Mr. G. Lepere athrms to have taken place in his' experiments. 



Experiments relative to Potash and Soda, Bj/ Mr, Ritter. Jounu 

dk thysiquCj April, 1808. 

TiiE several metals were tried as to their effects when used a$ 
the negative pole of the galvanic apparatus in the metallisation 
of potash. 

The me talloif substance of potash was obtained perfectly well, 
and quite, pure wben platina, gold, silver, copper, brass, nickel 
reduced per *e by Ricbter, cobalt, niccolane prepared by Richter, 
antimony, chrome, brown suboxide of molybuene prepared from 
molybdtnate of ammonia and which conducts galvanic electricity 
as well as a metal, bismuth; tin, lead, 2iac, charcoal, and plum- 
bago wer« employed. , , . 

Arsenic produced the metalloid sul>stan'ce in blackish globules, 
sometimes quite black. 

, Crystallised oxide of mangajiese did not produce any metalloid, 
but was itself disoxygenised. 

Quicksilver globules placed in an excavation made in potash, 
and connected with the apparatus by an iron wire from the 
negative end, became thick, .and when separated from th« 



184 Mr. Jxitttrs Expcrmeffti rilatke to Potash and SoJa. 

potash, they grew solid: the quicksilver haying amalgamated witfi 
the new fortued metalloid. If this experiment was so conductetf 
as to moderate the heat, the amalgam tVeqnently crystallised upoiy 
the potash, or at lea^t when separated from it, in cubical crystals, 
which formed a kind of paste with the remaining unsaturated 
amalgam ; thi? paste, after sonie time, became grca&y or rather 
BOdpy to the feel. 'I his amalgam is slowly decomposed in oiJ 
of olives, gas is emitted, soap is formed, and pure q«icksilvef is 
left; bttt it may be preserved in naphtha, h does not detonate 
with water, but yields a current of small bubbles -of hydrogen, 
pure quicksilver is left, and the water continues caustic |)olash. 
This amalgam is the easier to be procured because the potash 
may be employed in a very moist state, by which c ire u instance 
'the action of the pile is augmented. On putting the amalgam in 
muriatic acid, although diluted, a very violent emission of hy- 
drogen takes place, but no detonation, and muriate of potash is 
obtained. In the open air, the amalgam becomes covered witU 
a white powder, which deliquesces, and forms a solution of potash, 
in which the quicksilver is left free and pure. It has at first no 
action upon the tongue,, but the taste of potash soon becomes 
apparent, and the emission of gas. If the amalgam is put into 
diluted muriatic acid, in contact with a platina wire, the wire 
yields much hydrogen, which shows that the amalgam is highly 
positive in respect to platina, for plalina in contact with quick- 
silver in the same acid do«»^ not produce any gas, and a very 
small piece of amalgam in contact with {^ large quantity of quick- 
ttilver in muriatic acid, causes t^n emission of gas from the whol6 
surface of ihe quicksilver- 
Water, or still better, muriatic acid, is an excellent method of 
discovering the smallest quantity of' the metalloid in quicksilvf^r,- 
hy reason oY the gas which they disengage. 

Quicksilver that has been united with the new metalloid com. 
bines more easily with platina, iron, or copper than before j 
and these combinations are still more easily made, when the 
metals that amalgamate with difficulty are used to foiirrthe com* 
munication from the quicksilver to the negative pole of the pile-.- 
In this Case the metal is dissolved in the quicksilver as fast as 
the new metalloid substartce is Ibrmed; When arsenic is usedv 
the amalgam adheies strongly with the metal, but so that it may 
be separated by mere rubbing. The union of the quicksilver with 
the new metalloid, does not depend upon the quicksilver combiu- 
ing with the substance that forms the communication with ih6 
pile, because it equally takes place when the communication is- 
lormed by a piece of native oxide of manganese. 

Tellurium being used as the negative pole of the pile, is the only 
one of the metals that does not produce the new metalloid sub« 
stance from potaslu The tell«rium loses its brilliancy, and is 



Mk Rkiers Erptrimenh relative tb Potash and Soda, liS 

H^isibly corroded; and a blackish brown substance is formed at tLe 
place ol' contact between it and the potash. It is therefore pro- 
bable, that tellurium attracts hydrogen more fi^rcibly than is don© 
by potash, and that the blackish brown powder is the hydroguret' 
of the metal. When the tellurium was placed under watt*r, op- 
i^osite .a poesiiive platina wire, no hydrogen was disengaged, a 
thick cH)iid of a flea brown colour was formed, and «^fterwajrds 
deposil-ed ; tlie tellurium became dall, black and corroded as when 
placed opon potash. I'his brown hydroguret of lellurium has a 
strong cohmring. actie^n upon the skin. Telluriilm is thus the 
only m^tal that absorbs all the. hydrogen that is formed at th^' 
negative end of the pile. When it was employed as the positive 
f»ole it cfto^ed all the oxygen formed from the water tt) be separated 
in a g4$eo»s st^te, while the bnlUaiicy of the tellurium was not 
affected in the leabt, in the same manner us when gold, platina^ 
or paUadium were nnployed : but 'nmie of these unite with the 
hydrogen of tlte negative pole in so marked a manner. ^ 

Would it not be pt>$8ible to. separate the oxygen from water by 
means of telliiiium? When that metal, however, was boiled in 
di&tilled water no gas was disengaged, although it became dull,- 
and coloured the hands and ,paper. Perhaps some of the new 
metals fomui in eriidti platina resemble tellurium in theee qualities. 
In geiwral the more oxidizable metals used a« the negative pole, 
produce in equal time more of the metalloid from potash than 
Ibe less oxidizable metals, or rather it is preserved the longestr 
lor as the new substance is very highly positive in resp? ct to 
the most oxidizuble metals, a galvanic chain is formed by the 
new metaHoid, the wire and the moisture of the potash, which 
determines the hydroguret of potash t*) oxidize itself faster than 
it otherwise would, so that less of it is obtained. On a similar 
analogy, when it is desired to precipitate metals by the pile from 
their solutions, it is proper to use a wire made of a more oxidiz- 
ahle metal, and it is even the best to ufee one of the same metal 
as it is meant to precipitate* And for obtaining the metalloid 
from potash, zinc, tin, or lead wire is preferable to those of 
platina or gold ; iron wire is also very proper. If the pile is 
very powerful, the new metal will combine with zinc or lead 
during the operation, as with qiaicksilver, and these alloys appear 
to have their melting point at a lower temperature than the 
pure metals. 

Seebeck, of Jena, is said to have discovered that all the 
eartlis are as combustible by the pile as potash or soda, and that 
the smell of barytes in combustion had a strong resemblance, to 
that of potash when it detonates with water. 

As yet no substances analogous to those procurable from 
potash or soda have been obtained from barytes, strontian, or 
lime> but the phenomena that deceived Mr. Seebeck are explan^ir 



I^ Mr, Laugicrs Analj/su- qfScapolite, or Parant^lheJ 

dble on the following grounds. 1. The great heat produced by 
the pile ; 2. The heut emitted by those earths when moisteneJ 
With water; 3. The different degree of solubility of those suh- 
£fCances in water,- at different temperatures ; 4, The infiinimabilit^ 
of the hydrogen disengaged from the negative pole, and brought 
about by the heat, and electric sparks that are* prodwced ; it 
having been already shewn in ldo6, liow a drop of water may b6 
> set on fire by the negative pole ; 5. And lastly, by the boiling 
of the soldlion that is formed. Kven when potash or ^da ar^ 
used, several phenomena are observed, whieh appear at first to 
Jinse from the decomposition of the metalloids, but which do not: 
As to the odour said to arise from barytes in thes* operations, it 
is owing to some of that earth which is carried up by th^ steam 
of the boiling water, or by the hydrogen and oxygen that arfr 
emitted by the two poles. 

As the three earths here mentioned, are those \Vhich have the 
greatest resemblance to the alkalies,- it ^as iiot thought neces^ 
sy.iy to examine the others at present, urttii str>onger piles cart be 
procured. 

It is probable, from some circumstances, that some new sub-' 
Stances are formed at the j.ositiVe pole, from^pbtash and soda. 

Obstrottiiom. — Wv, Davy has replied to some parts of this pa- 
per, in his Bakerian lecture, just published in the Philosophical 
Transactions for 1810, Part I. The bydrogexiisem'ent of tellui' 
riura by the negative pole, streijgthetis the conjecture of the fo- 
reign chemists, that the pretended metals from potash and soda 
are really hydrogurets. 

The deceptive appearances thiert ocCur when the earths are ex^ 
posed to the pile, are worthy of notice, and may have misled 
Some English chemists, Ml the eageiTness of their chace after dis- 
coveries. 



W|PM— — ^^.i^Wji^w*.— WW.j»WW>WW^.^>—« n i ^W ■» IM K IWWPI— ■»;i«>WT»l— — — 



Analysis of ScapolltCy dr Patanthine, Bi/ Mr, La udiEU.—^ Jaw/7?'. 

de P/ij/s. April, 1 808. 

Ir contains 45 per cent of silica, 33 of aluinine, \7'6 of lime, 
r of oxide of iron and manganese, 1*5 of soda, 0*5 of potash, aad 
1-4 were losU 

These constituent parts are very similar to those , of preh- 
nite fix>m the Cape of Good Hope, as determined by Klaprothl 
'X'he. specific, gravity of the two stones are neaily the saiue, that 
of paranthiue being 274 and of prehnite 2*69. 



< ifiT-v ) 



Pn the Chabasie, or cubic Zeolite^ of the Island of leroc, Bt; Mr, 
Vauquelin. — Journ. de Phj/s. May, 1808. 

Tins stone received its present name from Bosc D' Antic^ 
,who first described il in an essay 'sent to the Society of Natural 
History, at Paris, Rome de Lisle considered it as a kind of zeo- 
lite. 

It contains 43*33 per cent of silica, 22*06 6f alumine, 33*4 of 
lime, 9*34, or perhaps more, of soda mixed vi}th potash, and 21 
of water, besides some traces of iron and manganese, which per- 
haps arise frorii the mixture of some particles of the lava in 
which it is found. 

It is probable that chabasie is attacked by acids, and forms a 
jelly with them ; but the quantity at command did not allow of 
any further experimei^ts. 



^^*n«(Wn 



Q;i the Properties of the nexp Allaline MettU* Btf F. R. Cu- 
VLA.\JX>AV4'^Journ, de PA^s, June» \S0$, 

Several of the plieoomena that accotppany the metallizatioii 
of potash and soda cannot be explained upon the supposition that 
the alkalies are merely disoxyg^nis^d ; neither will this theory 
agree with the properties of oxygen or of jv«nmonia. 

These researches are the more intej-estipg to the author, be- 
<;ause the results of the experiments published by him in the year 
10, announced the decomposition of the alkalies, and might in^ 
deed have led to the prediction uf tbieir being capable of metalli- 
zation. 

, In- respect to the m^feal^ of the alkalies containing carbone as 
cin essential ingredient, the two following experiments sedm deci" 
sive. , 

Silica heated in a glass tube with the alkaline metal, combines 
with^the alkali, and the carbone is left free, and can only be burn-d 
by heating it with access of nir. 

Secondly, a piece of the metal of soda being wrapped up in 
some sheet lead, and immerged in hme watei^, the metal was oxi^ 
^ized, and carbonic acid was formed. 

From these experiments it follows, that the attraction of the 
alkaline metals for oxygen, is a delusive appearance, occasioned 
by the presence of carbone. That carbone may be obtained fjon^ 
these metals. That the lightness of the alkaline metals, is pro- 
bably owing to hydrogen being also combined with the alkalies 
$^ these reductions. And lastly, that the various trials wli^ich 



f S8 Mr. Sage on the Exhtencc of Alunilne in Stones. 

.are made for disoxygenising different sul)slances by means of the 
alkaline metals will always give equivocai results as l<mg as any 
of the elements of these singnlar substances remain unkuowh. 

0/»5e;Tff^io«5.— The caibone which appears from the above ex- 
periments to have been present in the alkaline meuls prepared 
by Mr. Curaudau, was, no doubt, an accidental impurity. The 
experiments themselves are very iniporfictly related, as not ihe 
least attempt seems to Lave been nuide to measure the (Quantity 
of the products. We learn however from tlieni, that the metals 
of the alkahes ran be combined wilh caibooe ; unle^&s it should 
rather be thought, that the traces of that principle proceeded 
^rom the ether, oi more probably oil, by which the metals had 
been defended from tlie air. 



SR 



Description of a Process for detennining the Existence of A famine in 
■ the Stones which haxe falltn upon the Earth* By Mr, B. G* Sage. 
Joum. de Vhysique, June, 1808. 

.Margraft and Bayen analysed stones by the action of sul- 
phuric acid, because they knew that fusion with the alkalies al- 
!tered the nature of the earths ; and this appears to be certain, 
because the most celebrated chenriists, as Klaproth, Fourcroy, 
Yauquelili, have not made any mention of atumine. Whereas on 
on examining the sto;»<?s that fell at L'Aigle, and Salles, near 
Ville Franche in the Lyonnois, by means of sulphuric acid, one 
fourth part of alum was obtained from the formei stone, and one 
eighth from the latter. 

The stone that fell at Salles was powdered, except one eighth 
that resisted the pestle, and being melted with borax, yielded iron, 
which, when passed through the rollers, was as bright as the 
finest steel. The powder, weighing 18 assay cwts., was distilled 
with an equal wei«ht of concentrated sulphuric acid, and yielded 
sulphurous acid with one 30Lh of sulphur. The residuum being 
'^•lixiviated, yielded crystals of sulphate of magnesia, or Kpsom 
salt, and alum tinged green with nickel and iron. As the resi- 
duum was not exhausted, it was distilled again twice with fresh 
Sulphuric acid, until 9 assay cwts. of very white silica or finely 
divided quartz were left. The ley of each residtnim was heated 
separately ; that of the first distillation contained much sulphate 
of magnesia, and but little alum-; that of the second and third 
contained more of the latter salt. On analysing the stone that 
fell at L'Aigle, all the leys were added together, and yielded on 
evaporation, first alum, and afterwards sulphate of magnesia. 

The proportion of magnesia and alumine appears to vary in 



Mr, Cadet on the UnxvhaksbmenessofTed* 189 

t)5^se stones, but»silica or quartz appears always to constitute one 
half of llif ill, and sulphur abput one 30th Dart. 

The existence of alum in lhej>e stones is thus shewn, by the 
same inrtms as it was discovered in hornblande ; and therefore it 
vs evidently necessary that minerals should beexammed by treat* 
ment with sulphuric arid. 

Tlje silica usually cited as a constituent part of stones, may, in 
many cases, be only the product of igneous salts with ba?is of 
hatron decomposed by the potash havinga stronger atiinity witht 
the acids than natron has with them. 

As the brilliancy of the metallic iron contained in these mete- 
oric stones d^d not appear to advantage in their fracture, it was 
tried to turn a cup out of that which fell at Salles, but it chipped 
%o much, that recourse' was obliged to be had to the file, and fric- 
tion upon a eastr iron plate, sprinkled with sand and emery. On 
polibhmg this cup with emery and Veiaetian trjpoli without 
water, for fear of rifsting the iron, the sUmc exhibited irregular 
spotij of a silvety whiteness, intertnixed with very small greenish 
yellow spots, disseminated through an ash gray quartzose mass. 

Obser sat ions. — The treatment of minerals \^ith sulphuric acid, 
has been often practised, and in respect to aluminous and raagoe- 
sian stones, which are not so well prepared by ignition with pot- 
ash, as the siliceous, it seems to havie some advantages; but the 
fusion of the aluminous stones with borax, which acts upon theiri 
in a very elBcacious manner, requires less apparatus and less 
time. 



r^n 



.—/ 



On the Unxbholesomeness of Tea. Bf/ Mr. C. T.. Cadet. — Jourm 

(le Physic[uey June^ 1 80S. 

Tea before it is dri^d, is of a more or lass deep fine gre^n co- 
lour ; its taste is bitter and &tiptic. 1 he teas that are sold, vary 
in tlitjir appearance, as some have passed through boiling water, 
and others are only dried. In general, imperial tea is deep green, 
green tea is puce green, hyson is blueish green, bohea is yellow- 
ish green, peko is almost black, gunpowder tea is grayish green, 
souchong is reddish. The odour of tea is equally various, and 
does not belong to th6 plant itself, being communicated to it by 
other aromatic plants^ as chlorantbus, olea fragiaus, commelina, 
sesaaqua, Arabian jasmine, and curcuma ; besides Florentine ox* 
ris. which the retailers put at the bottom of their canisters. 

The infusion of tea mad6 at 70^ or 80°; which is the most 
usual heat, does not redden infusion of litmus. Mineral acids en- 
liven the colour when they are dilute, and destroy it when the/ 

^'o. 24. — Vol. vi. 2 c 



IpO Mr* Cadet on the Vn-ohoUsoineness of Tea. 

are concentrated. Alkalies turn it brown. It precipitates txlU 
phate of iron black, and it coagulates a solution of glue. 

Decoction of tea has the same properties, and also Jets fall mu- 
cilage, on alkohol being added to it. \Vhen the decoction is very 
strong, it dyes woollen, by the help -of a mordant, of a good nan'^ 
keen colour. 

A tincture of tea made with alkohol, yields ink with sulphate' 
of iroE, and contains a large quantity of resin mixed with extrac- 
tive matter. Half an ounce of tea, yielded a drachm and a hal^ 
of resinous 'extract. This tincture dves silk of a fawn colour. 

Tea appears to contain extractive matter, mucilage, a laige 
proportion of resin, gailic acid, and tannin. I'he two last prin- 
ciples explain the febrifuge quality assigned to tea by some me* 
dical men. It is not necessary to mention the fixed principles of 
tea. When, however, the leaves of tea which had been infused, 
were dried and burned at the flame of a candle, the edge of the flame 
was tinged of a green colour ; nevertheless the niost accurate trial? 
could not discover the least trace of copper, either, in the leaves 
or in iheir ashes: there were only found charcoal, iron, and mu- 
riate of alumine, but no potash, so that if any copper be present, 
it must be too small a proportion to be hurtful. 

Superfine hyson contains the greatest quantity of gallic acid; 
then gunpowder tea, pouchong, souchong, imperial, hysonsekin, 
green, tokai, peko, and lastly bohea. 

Superfine hyson also contains most tannin, then gunpowder tea, 
imperial, and seuchong ; the other sorts do not contain any. 

Superfine hyson is most abundant in resin, then imperial, gun* 
powder tea, souchong, hysonsekin, green, tokai, poucliong, peko,- 
and lastly bohea. 

Peko contains most mucilage,, then pouchong, hysonsekin, 
green, lastly tokai and the other kinds. 

Superfine hyson contains most extractive matter, then imperial 
gunpowder tea, souchong, hysonsekin, green, tokai, pouchong,- 
peko, and lastly bohea. 

Hence it appears that the teas which are most carefully pre- 
pared, contain most of the astringent and resinous principles, and" 
as these teas are carefully roasted, it is probable that the roasting 
developes these principles. Bohea and peko, which are gathered 
in May, and have probably been infused in water before they 
, were dried and rolled, contain very little astringent matter ; but 
the peko contains so much mucilage, that its decoction draws out 
hi threads, like that of linseed. 

Again, for a styptic and astringent drink, hyson o** gunpowder 
tea must be used ; for a slight tonic without any astringency,. 
green tea, or tokai ; for an emollient and detersive, bohea or 
peko. 



Mn Curaudau*s Experiments on Sulphur ^ ire. 1 $ I 

^he leaves of lea when fresh gathered, are of a very disagree* 
Able bitterness ; and have so strong an action upon the nervous 
system, that they even occasion deiirium ; but the preparation 
given to it, and the length of time it is kept beiore it is used, di« 
tninish these deleterious effects, although perhaps they do not en* 
tire I y remove them. 

When a ridiculous Anglomania had possessed the IVench peo- 
ple, they adopted the fashion of druiKing tea, and inimediabely all 
the fine ladies had the vapouis ; the revolution altered t||e fashion, 
and the vapours of the present beauties are now more trequently 
•pretended than leal. 

It would be more political to use the herbs of Europe*, some 
,of which yield agreeable and wholesome beverages ; but if, how* 
ever, fashion must have foreign plants, tht* Sjiauiards could fur- 
nish the capraria biBora, and anserina oi Mexico, or the erythioxy- 
lon of Peru ,* and the Ai^cricans, the ca&sii»e «f the Apalachian 
mountains, the ceaoatlius,^ t4ie nionarda ot Osv/cgo, the psoralia 
of the Jesuits ; or there might be pnjcured from New Holland, 
the leptosperma, or the salsaparilla glyciphylla ; but it would be 
^till better to cultivate at the lale ot France, the precious aya- 
pana, which is superior to aU the ditferent i^inds of tea, in scent, 
and every ather particular. 

«■ i M f. I ■ ■ imn 

t AM 

Ohsercations, — The known aversion of Buonaparte to commerce, 
and his earnest endeavour to provide substitutes for the articles 
hitherto imported into France, were evidently the latent causes 
that induced his obsequious apothecary to compose this paper, in 
,Drder to induce the subjects of his master to forego the use of 
t«a, as it is chiefly procured through the medium of the English 
nation. However much we must, as merchants, deprecate this 
^conduct, we cannot but do justice to the patriotism ot the author, 
or rather of his imperial prompter, ijbere has already been 
given in this work, some exceUent kiuds of British coffee, see vol. 
iv. p. 440 and 470, and numerous papers have lately appeared 
on the manufacture ofsugar, or a syrup, of equal sweetening trom 
European plants. Alttiough a long c<<urbe of years will probably 
elapse before these substances will drive the foreign articles al- 
most entirely out of the shops, yet it is evident that the native 
European products will at lust acquire the preemmence, in spite 
of the great infiuence of the mercantile class. 



Experiments on Sulphury and on its Decomposition, B}f Mr. Ct;- 

RAUDAU.— -/tfii«. de Chim, vol. 67. 

Although those bodies which do not suffer any alteratioa 
from the agents to which they have been submitted, are usually 



192 Mr. Curaudau on Sulphur and it$ Decomposition* 

considered as simple, \et it is to be supposed that the principfe 
into wi)ich the bodies of the njineral kingdom are res/ilved, ar 
compound > ot the same retiiote pnncipies as enter ia^to the com 
poeiuon ot'^ vfgftables and animals, and differ tVoni them only 
by the very ^Tcat contraction which the principles must suffer 
before they can enter into th« composition of minerals. The ap- 
parent indestructibility of the proximate principles of minerals, 
therffwre, aiibes from the diHiculty of making them undergo u 
kind of ietrograd*tion, by their remote printijiles becoming less 
condensed. In reality what other power, but that of the conden- 
sation, and mutual atti'act.on of the principk's iif, minerals, cuulji 
enable them to resist the dilating power of caloric. Fire, in 
consequence of this resistance, can only be used as an interme- 
diate a^'ent for their defitruction. 

Sulphuric acid, strongly impregnated with nitrous gas, renders 
water blue ; from whence it was conchi.ded, that sulpiurr conr 
tained carbone. The solubility of sulphur in oils indicated that 
sulphur might be a compound of carbone and hydrogen. These 
conjectures led to an attempt to separate the supposed principles 
of sulphur, or to combine them with a third principle that might 
form with them a compound already known. For this pur- 
pose, azote appeared very convenient, as it would form prussic 
acid with the principles of sulphur, if they were rightly ascer- 
tai.ied.' 

Four parts of animal charcoal were therefore mixed with two 
of sulphate of potash, and the mixture calcined in an iron tube. 
The mixture was heated to a cherry red, and when* cooled, was 
flung'into a sufiicient quantity of water. The liquor being fil- 
tered was of a green colour verging to blue according to the posi 
tion in which it was beheld. This solution had but a sligh 
smell ot hydroguret ; and its taste, although not (^uite similar 
to that of the prussic radical, lelt on the tongue a ta.ste which 
'resembled it. 

On endeavouring to separate the sulphur, it was found that 
the acids, even the oxymuriatic, scarcely rendered the solution 
turbid but they disengaged a particular and excessive fetid odour. 
In order to discover whether any sulphur was really contained in 
this. solution, a few drops of a solution of sulphate of iron oxid- 
ized ad maximum was added to it. This throw down a blade 
precipitate in abundance, which changed speedily to bliie on a 
further addition of the sulphate. Wlience it was evident that 
the sulphur had combined with the azole of the animal charcoul 
and iornted a compound analogous to prussic radical. 

Sulphuric aCid saturated with nitrous gas added ^ to tlie above 
solution threw down an abundant yellow [)rccij)itate, which had 
the appearance of sulphur, and exhalud the smell of it wh^'n 
burned upon live charcoal. This prtcipitiitc was no other than 



Mr. Descrmzilles on Violet pic/de, Sfc, 19$ 

t9i« radical, which might be changed, at the instant of its forma* 
tion, into Prussian blue, by adding some sulphate of iron. 

This radical, although analogous to the prussic, differed frona 
it by a superior de(»ree of fixity, as it wds not disengHged from 
its solution by the strongest acids, ahhongb they all of them 
decompose prusyiate of potash ijumediately. The superior 6xity 
of this new radical is probably owing to the condensation of 
the hvdr<»gen contamed in the radical being as great as it is ia 
sulphur itHelf ; although azote is able to lessen thi» condensation 
by forming ammonia with hydrogen by the decomposition of 
prussiate of iron. 

The present experiments do not yield any data, as to the 
determining wlu-ther hydrogen or carb^me be the predominant 
ingredient in sdphur, or their relative proportion. But solutions 
of sulphuretted azote of potash all contain an excess of car- 
bone, which falls down, if the liquor is loft exposed to the air; 
from whence it mav be concluded that the azote does not find 
in sulphur the necessary quantity of carbone to convert :t into ^ 
prussic radical. 

In another paper, the elements of phosphorus and iron will be 
given, and the alkaline metals will be treated of, which somie 
affirm nut to contain carbone. 



Observal ions. '^The report made by a committee of the Insti- 
tute appointed to examine this, paper will be found in this iinm- 
her : and tbe observatiods there made absolve us from our task. 
It is only necessary to state in general terras, that the analogies 
upon which Mr. Cura^dau relies, in this or bis other papers on 
different subjects, are very slight, and by no means sufficient for 
the purposes for which he produces them, and that there is a 
total want of that \iccurate statement of weights, &c. wiih- 
put which th« best contrived experiments are of little use. 



O.n violet Pickle y considered as a Test liquor ; and of' salting Vegc» 
tablts to pnservq them for dial'Jlation, Ej/ Mr, Descuoizilles, 
the elder. Ann. de Chun. vol. Gj. 

Syjiup of violet is a very common ^test liquor for either acids 
or alkalies, but it is subject to many inconveniences, for in warm 
weather it terments, the corii Hies out, and the syrup either dries 
up, or the iiifts get into it, are drowned, and alter its properties. 
'lie nee, a brine impregnated with violets was found upon trial to 
be preferable. 

This brine, or violet pickle, was made by pouring upon the 
petals of violets, sUghtly compressed in a pewter vessel, twice 
iheir weighl of boiling water j the vessel being then, covered, wjfs 



194 Mr. Rerthollet on Chencoi^'s Experimenis on Platma. 

kept for some hours at a temperature rather superior to that of 
baths, and afterwards strained through a linen bag, which was 
squeezed very hard. The infusion being then weigiied, one third 
of its weight of fine white kitchen salt was added to it ; by 
which means a fine blue pickle was obtamed, that could be pre^ 
served in all weathers; even m the rays of the sun« and which 
was far preferable as a test liquor to syrup ot violet. Lark- 
spur flowers have also been tried, and succesbfully ; it is probable 
that flags and several other blue flowers would yield a pickle 
equally useful. 

(Common salt may also be used to preserve vegetables. Rou- 
elle p(^rfumed his elaboratory, during his winter course of clie- 
mistry, in 1775, by distilling roses which he had salted in June. 
Salted roses kept for three years have not ytjt lost their perfurue. 
This pickling is performed by rubbing 51b. of roses at a time, 
for 2 or 3 minutes with a lb. of salt, which, extracting the juic.e 
of the flowers, produces a kind of paste that takes up but little 
room. This paste must be kept in a close vessel, and a cool 
place. When it is intended to be distilled, it is diluted with twice 
its weight of pure water, this method of salting vegetables is 
advantageous in bringing flowers, &c. from the places where 
they are ^rown to the elaboratories in town, and in keeping those 
vegetables ready for distillation, the distilled waters of which will 
not keep for any time. 

Ohsercations. — ^This is certainly a very gpod method of pre- 
serving the blue juices of flowers, for the purpose of their being 
used as re- agents ; nor is the method of pickling vegetables les$ 
useful. 



On Chenevix's experimaits. on PUit'wa^ and on those of Dchccstils^ 
By Mr, C. L. Beutiiollet. Ann» de Chim, lol. 67. 

Chenevix has shown, in the Philosophical Transactions, that 
a combination of pUtina and quicksilver in certain proportions, 
can sustain a violent heat without being decomposed, is fusible, 
and has some resemblance to palladium ; but Rose and Gebleii 
announced tha't they had obtained diff'erent results. 

The method, pointed out by Chenevix, as the most proper, is 
to boil quicksilver in nitric acid, and pour the nitr-ate thus ob. 
tained into niuriatic solution of platina; a precipitate is obtained, 
which on being washed, and reduced with borax in a crucible 
lined with charcoal, yielded a metallic button, whose solution in 
nitro muriatic acid was precipitated by green sulphate of iron. 

This experiment was repeated, and a button was obtained, of 
the specific gravity of 17. l)escostils having boiled a mixture of 



Mr. Isdgrctngff on tht Lf fives cfnd Stalks df RUiharh, 193 

grten sulphate of iron, and of solution of platina which contained 
but a \^x'^ small excess of acid, obtained an abundant precipitate ;• 
so that, this property belongs to platina itself: the precipitate, 
however, when quicksilver is employed, is i'usible. 

Descostils then tfe<ited platina with borax in a crucible lined 
with lamp-black, and obtained a button exactly similar to the' 
former. On dissolving this button, boracic acid was obtained. 
Platina therefore combines with the whole, or some part of 
borax, and the alloy has a metallic aspect, is hard, very brittle, 
and crystallized in the internal pan. He has observed similar 
phenomena with other metals. 

The precipitate obtarined in Chenevix's experiment is not 
fusible unless borax or charcoal is employed, so that its fusion 
depends upon these additions, and not by the quicksilver. Che- 
nevix himself had observed that platina might be melted by 
means of borax ; this fusion was probably made in a lined 
crDcible. 

To distinguish the action of the two substances, Descostils* 
treiited platina with charcoal only, and. obtained a button aug- 
mented in weight 3 per cent,* whose specific gravity was 18. Thi* 
carburet is very hard, very brittle, brilliant^ and kmellar in its 
ifnternaT part. 

Platina treated with borax only was not melted. 

Observations. — If we recollect aright, Willis operated the fusion 
6f platina by placing it upon a bed of coal in the bottom of a 
crucibfe, but he attributed the fusion to the bed elevating the 
metal to the hottest part of the crucible. His experiments arc 
Contained in the English translation of CreH's Chemical Journal, 
which was very eanrly discontinued ; but we have not the book at 
Iiand. 

On the existence of oxalic add in the Leaves and Stalks of Rhubarb. 
By Mr. Bouillon Laguanoe. Annales deChimie, vol, 67. 

SCHKELE knew of the existence of oxalate of lime in the root 
of rhubarb; but the juice of the stalks and leav«s have not 
been examined. 

The yjittt of the leaves and stalks is limpid with a yellowish 
cast, its odour approaches to that of melilot ; it is acid, and reddens 
paper and tincture of litmus. The pare and carbonated alkalies 
turn it deep brown, but do not cause a precipitation. Oxalate 
of ammonia produces no change in it ; lime water forms a white 
precipitate, whicn is unsoluble in water, but soluble in acids. Mu- 
riate of hme forms an abundant white precipitate unsoluble in 
water^ but soluble in nitric acid. Acetate of lead yields a 



ig6 Mr. Laurens on the u^e of Soda ill th Soap-works dt Mhrseiilei; 

yellowish white precipitate. The precipitatte from nitrate of 
quickJiilver, or nitrate ot silver is white, and mostly soluble in 
nitric acid. Muriate of tin y^eld^j a yellow precipitate. 

From thfseexperim nts it appears that this plant .contains an 
Hncombined acid analogous to the oxalic, and an extractive matter 
which combines with oxides of tin and lead; but that it docs not 
contain any calca.eous salt. 

liy distillation, the juice yielded a lirtipid aromatic liquors 
This liquor was not acid, it produced only a slight precipitate 
with acetate of It^ad, which was soluble in nitric acid; it did not 
allect lime water, barytes water, or muriate of tin. The re- 
mainder of the juice being evaporated to a syrup, and left foi; 24 
hours, yielded muph crystallised oxalate of potash. The mother 
water was high coloured, and although very acid contained 
scarcely any oxalic acid. The acid being probably the acetic^ 
combined with extractive matter, as in many other plants. 

The mass being evapnrated to dryness, gave to alkohol at 40"* 
hydr. a yellow tint; this tmcture was acid but did not /contain 
oxalic acid. The undissolved residue was acidulous oxalate oi 
potasli, which left on being incinerated nearly pure potash,- 
slightly carbonated, with a small quantity of sulphate and muriate 
of potash. 

Ilence the juice of the stalks and leaves of rhfum palmatuin, 
contains a great quantity of acidulous oxalate of potash, an' 
unprystallisable acid, combined with an extractive colouring mat- 
ter, which has the properties of the malic acid. 

It is therefore no wonder that Scl:eele found oxalate of lime 
in the root of rhubarb, as in many other plants, although in some 
it was n^,essary,to treat them lirst with muriatic acid to dissolve^ 
the salt; and then- to precipitate it by ammonia. 



On the use of Soda in the soap tvorks at Marseilles. Btf Mr. 
Laurens. yJmiahs de Chimie, vol, 6j. 

There exists a great variety ifi the nature of the soda usually 
srold, and the quantities of alkali that it contains At present, 
' the appearance of the soda aad its taste are the ot>ly guides to^ 
the purchaser, who is, however, well aware that it is only the 
pure alkali that contributes to the saponification of the bil ; but 
these criterions are not sufficient. Among the various proceasesi* 
that might be employed to ascertain the quaiitity of pure alkali 
contained in the mass, the following is pnd that may b^ practisec^ 
by any person. A given quantity of the soda is treated with' 
Vr'ater until all the soluble part is dissolved ; to this solution, mu* 
riatic acid (spirit, of salt) is^ to be added until it no* longer catts^- 
an effervescence. The quantity of muriatic acid that must be 



f 



/ 



Jffr. LauratSf on th use of Soda in the Soap-uvrhs at Marseilles. 1^7 

used to saturate diOerent specimens of soda, shows their relative 
quantity x)f alkali : and the real quantity may be known by sa- 
turating a known quantity of pure soda with the same mnriatic* 
acid. It will, however, be fuund that the pi:ce ot 5oda is not 
always regulated by the quantity ot" alkali it Lt)Uidins. 

The sulphuretted j-oda exhibited by analysis, enhances the 
price, and experience shows that it^oes not enter into the com- 
position of soap. The separsktion of -this bulphu raited soda, as 
proposed by Figuier, (see Retrospect, vol. v. p. 293) will by no 
means iHtswer in an econotnical view. 

Although sulphuretted soda does not enter in the composition 
of soap, it produces a chemical phenomenon which is ol gr«fat 
importance in the manufacture of that article, namely, the hydro- 
sulphuretted oxide ot imn which occasions, the pale b'tie colour 
that characterises the best soap. This colmir may be produced 
bv mixing together ^leen sulphate of iron, ^nd a bydroguretted 
ftlkaline sulphurett, formed either from potash or soda. This 
phenomenon is daily observed m the manufactory at Marseilles; 
Jtnd has been produced by addtng hy^roguretted sulphKiret to soap, 
that had as ursual been treated with sulphate of iron*- Some ma- 
nufacturers ascribe a power of destroying this blue colour to certain 
Specimens of soda, hut lliis in fact is meiely owing tosulphurett not 
being Ci>ntained in these specimens, so that ihey will not .produce 
the desired, pale blue colour* ^ 

The different phenomena arising from this celour has a coti- 
siderable influence on. the sale of tlie soap, and merits attention. 
If one part of allialine Lydrogu retted sulphuret and four of 
green sulphate of iron be added to the mass of soap, the 
hydrOsulphuretted oxide of iron loses the blue colour and 
acquires a rust colour. This effect, takes place when the soda 
ased in making soap contains little or no sulphiiret. Two parts of 
sulphate of iron, and one of alkaline hydrognretted sulphuret 
produces a blue colour in the soap, which is altered by the air, so 
that the soap acquires what is called an Isabella coloured mantle. 
Equal parts of hydrognretted sulphuret and of sulphate, cause the 
soap to be less altered by the air. And lastly, two parts of hy- 
droguretted sulphuret and one of sulphate cause the soap^ to be 
still less alterable by the air, and to acquire at last a blueish colour. 
Now as the proportion of sulphuret contained in soda varies ex- 
tremely, the manufacturers are obliged to leel their way by trials; 
but they arfe well aware that an excess of sulphate of iron produces 
that Isabella man lie which they wish to avoid. 

It therefoie appears possible to determine by experiment the 
good or bad qualities of soda in respect to the manufacture of 
uiarbled soap, but this cannot be done without exactly d^tpreciat- 
ing the quantity of sulphate and hydroguretted sulphunt that it 
contains. It is also evidently necessary to abolish the use of 
those drugs, which, although they contain little or. no alkali are 
No. 24. — Vol. yu ' 2 d 



}{!% Vauquelin and Bertholki <m CurwdauU experiments on Su^i^ir^^ 

nevertljeless used to produce the blue colour ; and as this colour 
.(Can be p.oduced with scarcely any expence, the quantity of 
alkim and salts coniained in soda ought to be the only stjandari) 
01 its price. 

The editon^ of the Annalts de Chimie take notice that Vaii- 
quflin had already propo&ed a similar method to determine tb^ 
quantity of alkah in potash, and mentioned that it would als(^ 
serve for soda. 

It is certain, they say, that the hydrogurctted sulphuret j^rodure^ 
p, very sensible effect on the colour ot marbled soap, l'>r it unites 
with iron and oil, and tornis a greenish blue substance, which 
dDc& not dlbi^olve in the soap, but ib merely disserninated through 
it. 11 soipe fnsh made maibled soap is treated with warm 
alkoboi, the undissolved residuum is this combination of oxide of 
iron, ^uiphuretted hydrogen ^nd oil. When ochre is» used to make 
^ed soap, a conibinatmn ot oxide ot iton, and even aUnniiie is ^ 
formed, which does not unite with the soap; but the sulphurettej 
hydrogen does not combine with the iron, because it is not in a 
proper state. 



^■BBBi 



Obseivations on Curuudau's experiments on Svlphur^ and its Decom" 
poitian, Ry. Messrs, Vavquelin aiid Bcrtiiollet. Amu de 
Chnnitt voL (57* 

' ■ 

Thrse experiments of Curaudau would not have been noticed 
if he had not himself loudly pioclaiaied xbeir importance as 
inferior only to the der^?"P^^'^'^*^ <^^ water. 

Curaudau's experiment (described in p. 192 of this number,) was 
repeated with only this variation, that m^tead of iising an iron 
tube some iron filings were mixed with the animal charcoal, and 
sulphate of potash, with an intention to investigate the state of 
the iron after the operation* 

'A liquid like that desrrlbed by Curaudau was obtained by 
elixiviatipi! tjie masb ; the lesidiiuru bein^ well washed was sul- 
phuret of iron, from wrhence muriatic acid disengaged much sul- 
phurated Lydro,gen. 

' The liquid contains potash combined with sulphuretted hydro- 
gen, and \\ith pru&fic acid, hot)] which may he disengaged from 
it m a gaseous state by ndding sulphuric or Hiuriutic acid. It. is 
&ht cuhnired by >( xne suiphuret of jn»n which is slowly deposited. 
If a lAile boiution ci' sulphate of uon ad iimximum is pt-ured 
into this Kquor, there i^*^ lormed a bldck precipitate ol sulphurnted 
iron, produceu by il e sulphiiretied hydioj^en, because the super- 
abunnant potash hinders ihe formation ot puitaiate of iron. But 
Vvhen a large quantity of sulphate is addt^d, tlie sulphuret of iron 

f decomposed by a part of the exccsb ol aCid ; the other pa^^f 






Vauquelin and BertholUl on Curaudau\ eTperimenti <m Sulphur* 199 

saCurates the potash. Prussian blue is formed and the liquor ia 
(Changed from black tb blue. 

Sulphuret of potash was treated with iron without charcoal; 
and it yielded on elixiviation; a liquid which resenibled the former 
in colour, although it did not contain any charcoal, and contained 
hydrosulphiir^tt of potash, but without any prussic acid. 

The pretended recompbsition of ^ulphur by adding sulphuric 
licid impregndt(>d with nitrous gas to the liquid, is iiothing but at 
j»rec]pitatiuti of th^ sulphur cdntamed In the sulphuretted hydrogea; 

IVlalfaerbe many years ago proposed the decomposition of sul- 
|)hate 61 soda, by charcoal and iron. 

As to Curaudau's opinion res)}ec.tihg the cbtidens&tioii of prin- 
ciples that takes place in minerals which he states to have beeii 
adopted by Berthollet; it is difficult to conceive stny resemblapce. 
between their respective idhas. AnU as to the decomposition of 
potash into lime and azote, Curaudau was desired to repeat hici 
experimients before commissaries named for that piirpose, but he 
was hot able to exhibit the ledst signs of thi$ decompositiiin, and 
it was supposed that he was himself convinced of it. But he has 
lately communicated three experiments by which he pretends ta 
confirm his former opinions; 

The !irst he mentions, i's, that when instisad of elixiviatirig the 
residuum of the calciufed mixture of animal charcoal, and sulphate 
of pottsh; it is mixed with one fifth of very dry sulphur, avoiding 
the contact bf air, and heated ; it yields at first much ammonia- 
cal gas, and then carburetted hydrogen gas. The ley made of 
the. cooled residuum, and ten times its weight in water, is darker 
^han in the former experiments^ because it contains iriore carbone. 
it also coiitains very little prussic radical, but oh remaining ex- 
posed to the aii* for some months, it acquires by degrees a greater 
power of forming Prussian blue, so that the principles of sulphur 
Appears to combine with this azote of the atmosphere^ and formd 
prussic radical. 

On repeating this experiment, lill the gas was passed through 
a bottle filled with water, which it impregnated with hydrogu- 
tetted sulphuret of ammonia; the gas itself was chiefly sulphu-^ 
tetted hydrogen, and carbonic acid gas with some carburetted 
hydrogen, and probably a little azote. Some of tlffe sulphur wa4 
sublimed, and the residuum being elixiviated did not yield any 
prussic acid, but hydrosulphuret of potash retaining a very little 
sulphuret of iron. It is strange that Cuiaudau should conceive 
that sulphur is decomposed in this experiment. 

The second experiment ttrbuld show that sulphuric acid im- 
pregnated with ilitrous gas destroy a prussic acid ; this may be, 
but it is foreign to the question. 

hi the third experiment, nitrous gas combined with sulphuric 
iBUrid or nitric acid, precipitates sulphur from a liquor upon wiiidi 



SCO Mesirs, Cuvier and Brongniari on tie 

the other acids, not excepting even oxyznuriatic acid, had noi Wtn^ 
fiible action. But this is incorrect, for the acids disengaged sul- 
phuretted hydrogen, from what Curaudau improperly calls 
azotized sulphuret of potash, and the nitrous gas nnly decompuseji 
the sulphuretted .hydrogen, and precipitates the sulphur. Sul-* 
phurous acid produces a similar effect. Oxymuriatic acid does 
not indeed sepaiate sulphur,, because it is converted into bulphuric 
acid. 



Ohserrat^'ons^^-^These remarks ol Vauqjuelin and Berthollet, are 
fully sufhoent to shew how little foundation Curaudau had for, 
his asseruov^s respecting the decompobixion atid analysis of 
sulphur. 



On the Mineralogic Geography of the imghbonrhood of Paris. By 
- Messrs, CvviiR, and Alexander BauNGNiAitT. Journ. des 
Mines, No, 13 a. 

The country in which the capitil of France is situated is per* 
' Baps the mo*t remarkable o\ an\ bitheito examined; on account 
of the succession of the dili'erent fornuitions, the remarkable organic 
remains "ih .t ihey contain, the ttlternate strata of «^pa shells, and 
those of fresh water, the uuknownland animals, some of immense 
size, which lie in the upper beds, and the very striking traces oC 
a violent ernption from^ the south east which aie exhibited by 
the shape ot the hills and the direction of the valleys. 

The materials which compose the basin of Paris, have beea 
deposited in a large open space, the sides of which are chalk;, 
this earth being the most antient of all the formations here de- 
posited. The formations may be thus enumerated. 

1. Cha^ formation, in beds alternaiing with those of flints^ 
which appear to have be^n formed by successive and nearly pe- 
riodical deposits.' The distance between the beds of flints varies^ 
^ being sometimes two metres, (yards) and at others even still 
further. The chalk coivtains 1 1 per cent of magnesia, and 19! 
of silica, great part of which may be separated by washing in the 
form of sand. It does not contain so many petrifactions as the: 
superincumbent beds of (oarse limestone. The petrifications are 
also entirely different; in paiticular it does not contain any plain 
regular spiral univalves. The upper part of the formation is 
as it were broken, and forms a kind of fragment-stone of chalk,, 
with clay in the interstices. The highest part of this formation 
is 15 metrfs above the Seiner so thai the superiricumbent beds 
are heightened, but they appear to be rendered thinner than usual.. 

In one place this chalk i? nearly naked in some points, being 
only covered with a macly sand, which is almost pure at top^but 

1 . - 



Mineralogk Geograpliy of the neighbmrJiood of Paris. 2C1 

contains in the inferior part o^ tbo Leil tragraents of fine grainecl 
limestone disseminated in it. 1 ho?e fragments contain yellowish . 
white calcareous geodes, with spathose lamina and small ca- 
vities lined with calcareous spar. These p.eodes also icontaia 
numerous spiral univalve shells, which seems to show that they 
do not belong to the chalk formation. One of the geodes con- 
tained a large cavity lined with limpid crystuls of sulphatcd ' 
stontian, or celestine, more than 002 metres long. 

*2. Potters clay formation consi ts of a bed of unctuous tenacious 
day containing silica, but very little lime; it does not etfcrvcsce 
with acids, and is unfusiblie in a porcelain furnace, unless it con- 
tains too much iron. It varies in colour, being either very white, 
gray, yellow, pure slate colour, slate mixed with red, and pure 
Ted, It is used for porcelain, and pottery, but it. sometimes con- 
tains pyrites, small fragments of chalk, and cjrystals of selenite, 
which render it less useful. The bed varies in thickness ffoiu - 
01 or 0*2 metres (3 or 6 inches,), to l6 metres (yard&) or more. 
It does not .contain any organic remains, for the frag Dents oi 
bituminous wood discovered by Dolomieu, were fbund in a part 
which had suft'ered some disorder, so that they were probably en- 
veloped in. the clay posterior to its deposition. The line of separy 
ration between the chalk and clay, is perfectly dis.ti act, and they 
do not pass into one another. 

3. Formation of coarse limestone. The coarse limestone does 
not always lay immediately upon the clay^ but is sometimes sepa- 
rated by a bed of sand. This sand does not conUiio any shells 
*8o far as is hitherto known, but as the lawermost bed of limestone 
is commonly sandy, and always full of shells, it is doubtful whethcK 
the sand belongs to tke 2nd or 3rd formation ; the sand, how- 
ever, procured from the clay, is generally sufficiently pure, and 
refractory although red, or blueish gray, and frequently in very 
large grains. The limestone is divided into several beds which 
pass insensibly into each other ; sometimes several of these beds 
are wanting, or very thin, but their relative order is never changed. 
The very sandy limestone that constitutes the lowest bed is 
sometimes friable; even when solid it falls to powder on exposure 
to the weather. . It contains a green earth analogous to the terre 
-eerte of Verona, ^.nd an immense variety of shells, of which 
upwards of 600 spec leis have been already described, and which 
Lave much less resemblance to the shells now in being, than 
those found ia the superincumbent formatioas. They are for 
the most part ia a very perfect state, well preserved, easily 
ijetached, and many have not even lost their pearly lustre. The. 
superior beds of this fjr)rraatiQn arc not so distinct ; they appear 
to be first a^ soft stratum with a greenish tint; the lower part 
2} as frequently brown impressions of leaves, ^nd stalks of plants,. 
tbeo gray or yellowish beds cQntaining shells, the upper pari o£ 



~.\ ' 



iOf Messrs. CwoUr and Brongniart on, ike 

ivbicfa is used for building ; lastly a thin bed of hard limestone 
containing an immense quantity of tellinae squeezed together; 
Above these come a system of beds of hard calcareous marie, the 
fragments of which are iisUally covered with a yfeUow varnish 
and black dendrites. These beds ai-e separated by beds of soft 
iralcareous miirle, clayey marie, and partly by calcareous 'sand 
Sometimes agglutinated together and cuntainihg bornstone with 
horizontal zones, lo this systfm may also be referred a bed id 
Ivhich crystals of quartz, and inverse - rhomboidal crystals 6f 
calcareous spar ar^ found. No shells whatCfver arc fritxnd in thi^ 
npper part of the coarse limeiltone formation. It is evident that 
the shells in this formation were deposited slowly in a tranquil 
Sea, and that it was either gradually despoiled of its shells, or 
had lost the property of preserving them. 

4. Gypsum formation, consistmg of alternate beds of gy^sunr 
and marie either Calcareous or claye)'^ The hills that contaitf 
h ftffm a long bafiid running S.E. and N.W. and about IS miles 
broad. These hills have a peculiar aspect, and appear like a^ 
Mcdnd hill placed upon the hills of limestone. The centre of this 
band has three masses of gypsum.; the ends and outside have 
only otte, which appears to be the uppermost of the three. - 

Th^ lowest System of gypsum beds consists of thin alternate^ 
strata of gypsum, which is frequently crystallised, solid calcareous 
marie, and very siaty clay marie ; the first contains the large 
crystals of yeUowishr lenticular gypsdm, and the last contains the 
toenilttc; iHo organic remains^ are found in this system. 

The second system only differs in respect to the beds of 
gypsum being ndiich thicker, and the beds, of mark less frequent* 
One of tkese beds is of compact marbled grey clayey marie. It 
contains fossil fish, and in the lower part some $ulpha;ted strong 
tian in scattered kidneys. 

The iippetmost system is much thicker^ sometimel^ 25 metres,- - 
it contains only a few beds of marie, and iti some places lie^ 
alm6st immediately under thfe vegetable mouki ; th^ k)wer bed^ 
of ;this gypsuiB contains fHnts which pass gradually into gypsiimv 
Ihe intermediate beds split into many sided large prisms, the 
epper beds are thin, peneti^ated with marie, and alteri^ate with: 
it; they are usually five in number. Thi^ svtftim cohtaihsr 
skeletons of birds, and unknown quadrupeds ; when found in the 
gypsum, they are solid, and covered with a thin coat of caN 
careous marie, but when found in the marie they are very fri- 
able. It also ccMitains, although but very rarely, fresh water 
shells i if indeed Ol^ly a single one had been found it would suffice 
to show that this formation had been formed in a fresh water lake«r 
Above thi« gypsum are large beds of marie either calcaieous 
or clayey; in the lower part of this system i^ a bed' of white* 
friable calcareous marie which contains $iiic6)us trUiikd df ^il)bi* 



Minerahgic Ge^grapky of tke neigkhmirkood af Paris. W^ 

I 

trees. In one place are found shells of the genera, lymnea an4 
planorbis, similar to those now living in marie ponds. Abave 
|his bed are numerous, and frequently thick beds of marie, in' 
nvfaiciir no petrifications occur. Afterwards there appears a bed 
P'6 metres, (i feet) thick, of .a yellowish slaty marie, containuig 
in its lower part nodules of earthy sulphated strontian, and a 
little above it, a thin bed of small xellinae laying close one against 
%he other. I'his very remarkable bed, which can only be disco^ 
:^ered l^y knowing its exact place in the system, has been found 
to extend, upward^ nf 30 mileti in length, by 12 in hreadth. It if 
the limit between the fresh water and marine shells, all above it 
being of the latter kind, as well as the tellinae it contams. Im<* 
mediately above this becj of tellinae is a very thick bed of green* 
ish clayey marie, used for common pottery, which contains no 
organic remains, but only argillo-calcareous geodes, and nodules 
pf sulphated strontian : it serves ^s a guide to discover tbp bed 
of tellinae just mentioned. The next four or five beds of marie 
are thin, and do not contain organic remams, bat they are co- 
veted with a bed of yellow clayey marie, containing fragments oi 
marine shells, and of the palates of a kind of raia analogous to 
raia aquila. The $i|ceeeding bed<» of marie contain marine 
bivalves, and those immediately under the clayey sand contain 
jtwo very distinct becjs of oysters, separated by a bed of whitish 
marie without shells. The oysters of th«^ lower bed are large an4 
very* thick ; those of the upper bed are divided into several 
strata, they are brown, n|uch snialler ^ud thinner than the for* 
mer : these beds of oysters extend throughout the ^hole of this 
formation, Slaving scarcely ever been missed. The forin^tion 
concludes at its upper part \yit^ a befl of clayey sand, which does 
Ziot contain any shells. 

It might be supposed, that this formation ought to be divided 
into two ; one containing fresh water shells, and the other ma« , 
line shells : but the beds resemble each other so much, and are 
jSo constantly associated, that it is merely sufficient to mention 
the' division. Sometimes the upper marles are wanting, and 
30 lAe times the gypsum is either totally wanting, or reduced tq 
jt very thin beA In the former cases the formation is repre* 
^nted by the green marie accompanied with strontian. . ^ 

5. Formation of sand and marine sandstone. This is but of 
small extent, and appears to be a supplement to the gypseous 
marles, but it does not constantly accompany them, and is fre- 
quently separated by the considerable mass of clayey sand just 
mentioned. It consists of beds of siliceous sand, for the most, 
part pure, and often conglutinated into sandstone, filled with va* 
rious marine shells. 

Here it cannot but be obsetred, on considering the above five 
formations, that at first' there was a sea depositing chalk, ^nd 



S04 Messrs, Cteoier and irongniari on the * 

different kinds of mollusca; this deposition ceased on a sudden, and 
one of sand and clay, without any organic remains^ took place. 
Another tea succeeded, which deposited a prodigious quantity of 
shells of a different kind; by degrees these grew scarcer, the 
place was covered with freah water, and alternate layers of gyp- 
sum and marie were formed, which envelope the remains of fresh- 
water-lake animals, and of those that lived upon its banks. The 
6(a then came a third time, and left a few bivalve and turbinate 
shells, but to these succeeded nothing but ousters. Lastly, the 
productioHb'of the second &ea returned. 

6. Formation of siliceous limestone. This is placed on the 
side of the last, and supplies its pltice in the country to the E. 
and b. E. of Paris. It is composed of distinct lavrrs of lime* 
st^ne, sometimes soft and- white, at others gray, lumpact, very 
fine grained, and penetrated with silica, which has iiaed its ca« 
vities with mamillary stalactites of dii!'crent colours, and very 
short crystals of quartz, usually vvitht>ut the prism, but trans- 
parent. Tiijb limestone yields by calcination very good lime ; it 
does not contain uny organic remains whatever. The stones 
called nieulieres, millstones, are the siliceous skeleton of this 
limestone, and may be imitated by' corroding away the calca- 
reous part by nitric acid : so that this substance has been ex- 
tracted by some uuktiown cause*, and bard porous masses, with- 
out any appearance of stratification, are left, whose cavities are 
still filled with clayey marie. This formation is frequently naked 
upon the surface of the ground, but is sometimes covered with x 
clayey marie, shell-less sandstone, or fresh water deposit 

7. Formation of sandstone without shells, is always the up- 
permost, or uppermost but dne, as it is never covered by any but 
the fi'esh water formation. 'J'he beds are very thick, and mixed 
vfilh beds of sand, which have sometimes been carried away by 
water, so that the superincumbent beds are broken and displaced. 
It does not contain any organic remains ; the sand is generally 
very pure, but is sometimes mixed with clay, or coloured with 
oxide of iron, or carbonate of lime has penetrated it in the 
parts where it is covered with the fresh water deposit. 

8. Formation of fresh water deposit. This always covers the 
others, the rock, of which it consists has the appearance of the 
siliceous limestone, and like that, forms millstones when the sili- 
ceous part only is left. . It contains shells similar to those found 
in our present mi|.rshes, viz. 3 species of lymnea, and planorbes, 
besides those small round and channelled bodies called gyro- 
gonites by Lamarck. The limestone, however hard, is broke 
up by water, and is used as manure. To this formation may 
probably be referred the sand found upon the tills, which con- 
tains silicified plants, as this sand also contains flints filled with 
the same kind of shells. This formation is usually found toward? 



' Minhrdlogical Gtogmpky bj the niighbomiodi of Tarisl ^^ 

£e tops oft. hills and on large plains^ but .seldom .or never in val«: 
ys. It shows that the fresh water formerly existing had the; 
property of depositing beds of hard yellowish limestone, white 
xnarlei anB silica, frequently very pure, whicK even changed thS 
Wganir. bodies living in that water to their own nature ; proper^ 
tifes not pnssesseci by the present fresh Watei*«. - 

9* Formation of mud. 1 his is composed of sand of all co« 
loQrs, marie, or clay, or a mixture of all three, impregnated with 
carbone, which > gives it a brown or black colour, it contains 
rolled pebbles, large trunks of trees, the skeletons of elephants, 
beeves, antelopes, and other large mamtniierous animals. It is 
hot qnly.lound iii the bottom of the present vaUies,' but also in 
places which have since been filled up* It is to these remains of or- 
ganic bodies not entirely decadiposed that the dan^eroiis eiBuviauf 
the formation when ^rst turned up are to be aittributed. Although 
more modern than the others, its deposition was anterior to any 
historical time^ and it may be said, that the old world was very 
different from th^ present, since the woods and animals found 
in this -forthatiiui aie entirely difl'erenU not op'y from the ani- 
mals that now inhabit the same place, but even from ail those 
known at present. 



t • » 



. Observations, '*^h\^ pap«T is more important than the gene i a-: 
lity of those tbjit treat of local subjects, because the chalk basin 
In ^hich Patfis is feitnated, also contains the rival capital, Lon- 
don; the basin appearing to reach from some distance to the 
S; E. of Paris to a line drawn from Dorchester, in Dorsetshire, 
to the coast of Norfolk ; arid thus including the whole S. £. of 
ftur island; and also from the great rarity of the chalk formation- 
of which only another, situated at the southern extremity of 
SSwedeh, and passing. under the Sea to Zealand acid the island of 
Rugen, is known at present. 

. Scarcely any sections of. the country in the neighbourhood of 
London hav^ beeh published, on account of its not containing; 
ores or i^oals, the great objects of miners ; but th« subject is 
Wrthy of aiiention, and might, receive some illustiatioh by com- 
t)aring the fe\y sections that are no# visible in diflerent places, 
and the tCccodiits of the -^trat^ through which welts have beeii 
8Uiik. , 

The alt^rnattoh of fresh arid *alt waiter shells is a[ remnrkable 
fact, as such mutations of lakes have not been observed in mo-' 
ilern times J but there still remains at least one instance of the 
ftilicifyitig lakes in Lough Neagh in Ireland, which seems to be 
gradually losing its petrifying quality. ' * 

f revost and Desmai-est, junior, have since published a paper 
in ^faich they mention the discovery of marine shells and otbef 
'remains of sea* anijnals ifi the lnw^st system of gyp^^um beds ; d<j 

bJo. 24.— Vot. vj. 2 t 



2D6 Mr. Johns' JpparMifat iJ^ DeeomposkAn o/Pdiast M Sddd 
thnt it » only tbe uppermost system that liM been d*poiited 



from a fresh water hike. 

OB 



Improved Method 6f prtpdrin^^ Phosphorus Bottlts, — Phil. JotirH. 

No. 117. 

The phoshonis should be' carefully dried by filtering paper, 
and a tbia ulicc being cot, it shuuld be divided into as many 
pieces as Ibe time will allow, and the piseces introduced into c 
small bottle, with as much lime as will surround it. The fooU 
tia may, when full, and forked, be expoied before a fire hqUI 
some<of the phosphorus has acquired an orange tint ; but if not 
required for immediate use, this heating is not necessary,^ and the 
omission of it will camte the phosphorus to eontinu* longer in a 
serviceable state. 

lime slaked in the air, and then ignited for ^0 hiinutes in # 
Mack lead crucible^ is very proper for the purpose. 

The mouth of the bottle should be closed with the finger at 
soon as tht matth is withdrawUi* 



ImsiBasaBaBsBimasmamsassiaammimiB^^ 



Description of an improved Apparatus for the Decomposition of tol'^ 
ash and Soda, By Mr, WiLLiAJi j6HNS.-rJ*/iJ/. Mag, No^ 
145. 

Ma. Davy enjoying ample resources from the Royil Iilstitu-' 
tiott, has given a method of decomposing potash and scKla by a^ 
bent gunbarrel, which is usually cut to pieces in order to get dui 
the product ^ but this is attended with considerable ej^penses^^ and 
therefore it was desirable to invent an apparatus in which this' 
charge might be avoided. 

The apparatus consists of a beat guhbarrel ;• an open potash' 
tube is ground into the breech end, so as to fit air tight $ tb*' 
bend at the small end of the barrel cdramences exactly at the 
point where it quits the fireplace, and it is cut off aboOt three' 
inches from this bend, and the piece cut ofi* again ground into tbi 
place so as also to fit airtight. A small thin iron tube, open at both 
ends, and made rather conical, is placed in the barrel when used,' 
so thi%t the middle of the tube may come opposite to the la^ men- 
tioned joint; this tube serves to collect the new formed metal* 
loid. To the muzzle of the barrel is screw^ a stop eock, to the 
other end q£ which is lated a glass tube, tht' l^wer end of which 
is immersed in a cop of olive oil. 

The iron turnings being brought tH a white heat^- the potash i^ 
supplied by degrees, when the last portion is added, and becinnt 
red hot; then, and not till then, the stopper is jpii'ux the tttbe>tfa^ 



Mrp W^kefs new Scale for the Thermometer. t07 

Jlttted over. The furnace uaed is a common black lead crucible 
jibout 8 inches diameter, and the fire is blovrn by a pair of daubU 
jbellows aboy t 36 in. by I f . 

This apparatus served twelve times, and wa5 at last melted in 
poe placjc, by the lute having fallen off. |n the last, 140 grains 
i>f metalloid were obtained from 11 drachms of alkali. Common 
caustic potash may be used instead of pure potash, which is eight 
times as dear. In another expieriment, 12 drachms of alkali 
yielded 170 gr. of metalloid. 

Caustic soda used alone did not succeed, but two drachms of 
.soda with 6 of potajsjb. yielded 6'0 g^rainf of a beautiful compound 
nearly ^uid, very brilliant^ and apparently of the same specific 
jgravity as naphtha. From 10 drachms of a mixture of 1 part 
soda, and 7 potash, 15Q grains oi metalloid were obtained, which 
resembled quicksilver, and was equally fluid at a low tempera* 
lure^ but ^onlei op very pui)e .naphtha. 



^sfspacfs^sfggwmafmm'SSSssasaaBsssmmssaBBBmt^ 



Qn a new ^cqlefqr the Thermotneter. B^ Mr^ Richard Wal* 

i^£|i.-ri''iJ^» -A/tf^. No. 146. 

' TiiERK are four different thermometric s.cales in use at this 
^inie. 

* 'Reaumur, by De Luc, 9* 80** 

Celsius, 0"* XOO^ 

De risie 15Q^ 0« 

The centigrade scale no^ used in France, \^ no other tbaa 

Ibat of Celsius, to which d.ecimal divisions have been added* 

Tbe proper place for 0°^ would, considering the thermometer 
as a measure of heat, be most properly placed at the point where 
beat commencejs ; b|it it is probable that this point will neyer 
l>e ascertaibec), and besides, the scale would be encuriibeted with 
a multiplicity of figure^ at, the part which would be in most fre* 
^uent use. 

It has been ascertained by physiologists, that 6^^ Fahr. is that 
poitft Bt which the human body in a state of health, i$ uncon- 
scioas of either heat or cold, in any season of the year, and iu all 
climates ;^ so that any temperature above that pomt, £ives> under 
ordinary circumstances, a sensation of heat, and any temperature 
'below it, a sensation of old. With respect to the divisions, 
those of Fahrenheit seem to be tbe fittest, in which case, the 
freezing point will be —30"', and the boiling point 150®. The only 
possible objection to this scale is the frequent use that it would 
occasion of the plus and minus characters. 



SPS 3fr Walker's nru: ScaUfor the Thermometer. 

For meteorological observations, this scale is peculiarly appro* 
pri'ated, the zero being the mean lempcralure between the great- 
est beat and the greatest cold in the hottest aud coldest climates', 
^blUctiveljr, as well as in temperate cH mates. Thus in Alrica, 
the heat uses to M\^ Fahr., or 112° proposed scale, and in some 
parts of North America the cold u —50*' Fahr. or -^1 13^ pr. sc. 
So also in England the heat rose to 1:26® Fahr. or 6*4° pr. sci 
<>n the a'kernoon of July 13th l80d, and the cold to —2^ Fahr,' 
or —64 pr. sc. on the morning uf Christmas day, 1796. The 
iriean annual temperature of Quito in Peru, is 62** Fahr., and tlie 
limits of the variation arc only 3 or 4** above or below it; ani 
this is considered as the healthiest spot in the world. By a welf 
known provision in the ammal economy, a f«w degrees 6elow ()2^ 
Fahr. is much more uncomfortable than the same difference 
above it. 

Although Fahrenheit's division is here preferred, the mode o( 
decimal divisions seems to be gaining ground, and might be em. 
t)loyed, iti Which case, t*he freezing point of water would be —20*^ 
and there would occasionally be a slight difference, but all the 
three leading' points are constant ; the remainder are n<>t of mucli 
consequence, and the detect is common in every scale ; thus quick- 
silver was really found to freeze at —38^ and two thirds Fahr. 
tut is marked at — 3C)*. 

The original idea was to place 0^ at the utmost degree of na- 
tural cold, and in order to ascertain this point, a table was formed 
from Kirwan's table of the mean annual temperatuie of every la* 
titude, in which the tempeiature of the b'igh latitudes are deduced 
,by inferences drawn from the others, and if- the results of this ta- 
ble are correct, the greatest natural cold is a,t 68^ Fahr,, or 100* 
below the freezing point of water.' If this point was adopted for 
the 0® of the scale, the use of the sign of minus would only be re- 
quired for such intense degrees of artificial cold, a:^ were below 
that point, which so far as has hitherto been produced, are only 
23, namely, — 91** Fahr.; the freezing point of water would be 
marked 100*^ and the boiling 280°. v : > . t • 

0!>serva{ion$. "^If we only consider the thing abstractly^ eithw 
of two pro;^ osed points of 0*^, are more proper than the ai bitrary 
scale of Fahrenheit now in use. We give the preference to the 
first, or that in which the scale commences at 62^ Fahr., and is 
Continued either way, as more agreeable to common language, 
which has two diHerent words to express the upper and lower de- 
grees, and of colirse most agreeable to those dictates of common 
sense which should inipej philosophers to fix aud dt^fine the pre- 
cise limits of comtiion expressions, but by no means to depart 
from them without unavoidable necessity ; and we conceive tlie 
scale would be more generally understood, if the degrees of t&e 

• • • 



Jfr. ParmenHer an the Gonurve ofGr^pc. U0§ 

■ f per scale were denominated those of heat, and the other, thos^ 
t)f cold, so that water might he said to boil at 15Q^ heat, add to 
freeze at 30** cold. 

The second scale l^a^ no other advantage over the common, 
than that th<s use of the sign minus would he less freqaent that^ 
at present, a^ is stated hy ^he author. 

We are averse however to 9^y alteration in matters of mer^ 
convention, from the confusion that it creates ; and as four scales 
are alre^y in use, which occasion labour enough to (persons whq 
read the works of foreign authors we do not consider the benefit to 
arise from the introduction of a new scale, to be by any means 
equivalent to the trouble it will produce. 



On Comerve of Grapes and its jlpplication to making of ll^ne* Bjr , 
Mr. FiiKMENTiER. — AnHuUB de Chimie, vol. 6?, 

To preserve the conserve of grape, twice as much juice of 
grapes is taken as the boiler will bold; the juice is slowly boiled 
Hnd the boiler filled up as fast as the liquor evaporates : when all 
the juice is got in, it .s scummed, and the evaporation, contmued 
potil thf liquor is reduced to three quarters. Tht; iiie is ihen di^ 
minished, and the mass, in order to prevent its acquiring a burnt 
•ta&te, is kept continually stirred with a large slice, ttii the operas 
tion is finished. \{ this slice is hung to the ceiling over the 
boilers, so as to reach to the bottom of it, the stirring will . be 
much less fatiguijag. 

The conserve is properly prepared when it acquires a middling 
brown colour, and when a piece as big as a nut is dropped upon 
a plate, it does not spread upon the pUite. It should indeed be of 
the coriSistence of hon^y, and poured very hot into very clean ves-* 
sels, which are not to be covered untihit is quite cold. 

A very considerable \x^ of (his conserve would be to give the 
requisite degree of strength to the juice of tho6i. gtapes which urc 
too watery to form gopd keepiqg wine, either on account of the 
backwardness of the season, or the mature ol the plant. 

In preparing the conserve, the farmer must beware of employ- 
ing too much Ibeat ; it mus^ be recoljected that sugar candy loses 
its power of crystallization by being kept too 'long over the fire, 
it is indeed by altering the form of the boilers, so as to evaporate 
the superfluous water wi^h the least possible use of heat, that it 
.has been found practicable of late, to obtain more sugar than b^- 
t«)re, with less treacle. 

It would be desirable if the superfluous water could be got rid 
of without the use of fire. Montgolfier says that he has made 
l^xperiments for twelve years on thickening the juices of ft uits. 
If I is process was similar to the graduation of sahae briiies;| and 



SlO Mr^ LagrangifB Ukfrvpiions <m Cvraudmts Papery if^* 

jiiffer oiily in the use of a very simple ventilator, by means of 
"whicli be eaosed SO eubie feet of air per second to pads throngh 
fogots of vine twigs from bottom to top. This quantity dissolve4 
from 1 to 4 grains of water, according to its dryness ; and hence 
a man working the ventilator for 1^ hours, caused the evapora* 
lion of nearly 500lb» of water ; and 4 strong horses in a larger 
Ventilating apparatus, might be made to evaporate (OOOOlb. of 
water in ^4 hours, so that nearly 30p0lb. of conserve of grap^ 
luight be prepared in that time. He also fopnd that each cubie 
ibot of air lost one degree of temperature by dissolyitig a grain of 
iraterl 



O^^erva/ion;.— -This paper is one of the many lately pu|)li8hed| 
in France, to bring forward the produce of Europe instead of the 
transmarine products of the colonies. 

The idea of giaduatiiig the syrup by means of artififtial venti- 
lation, might perhaps be beneficially extended to many similar 
evaporations, and is worthy of the attention of sal^ makers, salt^ 
petremen, and others, in situations where fuel is scarce and XslL 
pour cheap. 



Obserwitians on Curaudau's Paper on tie Influence wkieh thtfim\ 
' cj utilh txercuci on the products obtained. By Mr. Bouillov 
laAOB.A^GZ.''r-^Jnnafesde Ckhnie^ vd* 67. • 

CvHAUDAU says, that although the stills made on the princi- 
ples proposed by Chaptal, pf a lar^e evaporating surface, are the 
best for quick distillation ; yet the coutrary shape, or tall narrow 
stills, vield liquors of much finer flavour. 

The broad low stills proposed by Cbaptal, ^ere impiediately 
adopted b^ the roanafactorers of brandy ; bat the difficulty of 
transpbrttng that liquor by sea, in' consequence of the war, has 
occasioned a preference to be given to spirit of wine, as the small 
bulk of that liquid occasions a saving of fifty per cent. In the car- 
riage, although the mixture of it with water, is by no means so 
'agreeable as real brandy. 

' For the last five or six years, stills superior to those of Chaptal 
have been invented and employed in the south of France, These 
stills mav be divided into two classes. 

The first class comprises the apparatuses invented by Solimani, 
* Fournier, and Isaac Berard, who adopted* the ideas of the ancient 
chemists, of passing the vapour through large serpentine vessels, 
immerged in water of a proper temperature, in order that thcv 
aqueous part of the vapour might be condensed and separated 
from tht spirituous, which is carried into another vessel for con- 
'densation, and is of course founded upon the principle thatalko« 



l^^i Henry on HorM^chesnwt. Sll 

hoi iLtid water condensa at different temperatures. Gay-LussaC 
heA fliiown however, that tH^ attraction between the vapotirs of 
wat^f WKi those of alkohol^ hinder ihdr being completely sepa^' 
tated. 

The seroiid cla^s was originally proposed by Edward Adam, in 
which the preceding principle of the aatients is not only adopted^ 
but also a new one. Ftir a series of stills is heated by the steiafli 
of a single one> the 6rst oh the series, which is passed through 
ihem successively in serpentine tubes. The condensing worm of 
the first still heating the- second 'still, and so on, by which several 
distillations are carried on at once, each yielding a product of 
different strength. 

All the apparatuses are accompanied with a great economy iff 
ihe use of the fuel. In some, the vapours to be cocdensedt ar# 
^ployed to heat the wine that is next to be distilled. In others^ 
ih^ heat that usually escapes, is used for that purposes Thi9dis«< 
peeition obliges the distiller to work night and day, until his msu 
ierials are exhausted* 

lilt elasy to conceive that spirit of £my repaired strength n»y 
De obtained, according to the dis lance that the vapour is obliged 
to-pa^ss, before it arrives at the condensing apparatus* 

It is therefore evident, that Chaptal made a great improventent 
in the art of distillatipn ; and indeed it must be observed^ that 
the distilling of wine is different from that practised by apotheca- 
H^, in which the whole of the vapour that is raised, is required 
•to be condensed* 



■ I'lii II I I < »— 



Obscroaikms.^^Vft shall hereafter have occasion to revert to" 
ibis subjec^t in a future paper, where the form of these Compound 
stills is described more at length. 



On Horu-Chesnut. By Prof. Henry, of Parti, Ann. dt 

Ckim,^ vol. 67. 

ParmentIsr says, that a fecula jrouldfbe prepared from the 
fruit of the horse-cheSnnt, (aeSculuS hippocastanum of Linnaeus,) 
and thstt, if this fecula were carefully washed, to take away the 
bitterness of the parenchyma, it might be used for food. Mar- 
candier affirms, tbat a ky of the fruit is used in Switzerland to 
Wash linen. The fruit has been long knoAn to contain potash, 
which might be obtained from its a&hes. Beauuie published an 
essay on this fruit, but the processes are too. complicated for do* 
inestic use. Parmentier and BoUillou- Lagrange, have compared 
the bark of this tree with quinquina. Zannic belli, an apothecary 
at Vcflite, employed this bark in 17 23^ against intermittent fe- 
vers. 



f !• ^Tof, Henry on HorseAAtimdl 

The bark of horse-cbesnut should be taken oiTbranches of th}^ 
br four years old ; it is blackish externally, and whitish internally,' 
its taste is bitter, but not disagreeable. It is very difficult to piil<^ 
verise, and when fresh powdered, smells like cacao. 

Cold water at 220' or 24"* Reaum. (77'' or 86^ Fahr.) poured 
upon the bark) almost immediately exhibits a violet colour by re« 
flexion, and takes in a few minutes a fawn colour ; the infusioit 
lathers wdU it is bitter^ but not astiingent; it reddens infusion of 
litmus*, and yields a dirty white precipitate with isinglass* Oxa^ 
lie, sulphuric, nitric^ oxymuriatic^ or acetic arid takes away its 
colour, and throws down a little precipitate. Potash or ammonia 
increase its colour, and the surface of the liquor appears deep 
blue. Barytes throws down a precipitate of the colour of lees of 
wine. Sulphate oi iron changes it greenish, and if more of the 
sulphate be added, a greenish precipitate is thrown down. Emc^ 
tic tartar is not decomposed by it, oxalate of ammonia renders 
it turbid, mnriate of barytes yields a fawn yellow precipitate; iu<^ 
trate of quicksilver ad minimum yields much precipitate^ which 
leaves the liquid colourless. Neither decoction of tannin, nor the 
infusion or decoction of quinquina atfect by infusion. 

The decoction of horse-chesnut bark, has the same properties as 
the infusion. If a few grains of subcarboiiate of potash are added 
to the water^ the docoction has a very deep blue colodr by t^l 
fleeted lighti 

Alkohol at 34S'° Cartier digested on the bark for 48"^ hours 
with a moderate heat, yield a tincture with a slight greenish tsnti. 
Water did not render tbis tincture turbid, but changed it to blue. 

Brandy at ^*2° acquired a much deeper colour. 
. Wipe dissolves the extractive principle oi the bark, and be* 
comes blue by reflected light. 

The watery infusion being evaporated to a synip, and left for 
25 days, did not afford any saline matter. During the evapora* 
.tion it became of a deep red, but was still transparent. Towards 
the end, and on cooling, it deposited a secfiment, which was soft 
to the touch and efl'ervesced with acids; this substance appears to 
contain much alumine and a carbt/nate. 

Twenty grammes of this substance b6ihg dried and distilled^ 
yielded Watef, oil, carburetted hydrogen gas, sorne earbonate acid 
gas, carbonate 6f ammonia, and ten gramnies of very friable char- 
coal, which on calcination yield 2-7 gramme^ of ashee^ containing 
a little free alkali, sulphate of potash, auli a Substance uiisoluble 
in acids. 

One hundred gr. of dry bark yield €5 of extract of the consis- 
tence for pills. This extract is reddish brown, and when dissoF- 
ved in water, the liquid i^ blue by reflected light. If the extract 
ii dried Opon plates in a stove ur water bath, it forms hyacinifii' 
colour scales, which attract the moisture pf the air.' 



JW>. Trommsdoffon art^cial Succinic jfdd. tl$ 

,. trhe l)ark of horse-chesnut seems to have no analogy with that 
tof quinquina in a chemical view* 

Observations. '■^Here we have another of theanticoJonial papers^ 
IThe war which the British ministry carried on against the French 
Vspitals, by endeavouring to hinder them from procuring Peru? 
yiau bark, will have at least the good effect of bringing into prac- 
tice some native vegetable substances, v^hicU will either be sub- 
l$tituted for. that expensive drug, or may at least be usea as a sue- 
cedaneum in a scarcity of it. 



" 'vv'iT ,""■";"' .. 



Oh crrtificial Succinic Aiid, Itompailiuss tulphurett^'d Alkohol^ Fecuhy 
and Cadet's aqueous JSUution of Camphor, Bj/ Mr . Tromms- 
doiif. Aiinaies de Chimief voL 67. 

. Succinic acid may be obtiitted by distilling saccholactic acid 
without any addition.. . , 

: Lampadiu6*s sulphuretted alkohol does not contain any car- 
tone, and ought to be called oily hydroguretted sulphuret. It dis- 
solves very speedily eight tiines as much phosphorus. The. solu- 
tion is still liquid, and easily takes lire by contact of air', on be* 
iug distilled, oily hydroguretted sulphuret passes over, and then 
the phosphorus; the sulphuret con lains some phosphorus, for the 
blue iBame is succeeded by that of phosptiorus. 

The. solution of fecuta in boiling water being thickened by ^ 
gentle firei yielded a seiiii transparent horny substance, not at all 
soluble in hot water. '1 his substance heing moistened and leit 
for five months in a wanii place, did not shew any signs of ier- 
mentation. Hence ferula ought not to be emplv*>yed in pharmacy 
for preparing masses of pills, but gum arabic or iugucatith should 
.be used. - It also shews how miich vegetable matters are altered 
even by water. 

The solution of camphoV in distilled water is rendered turbid 
by pure soda, and therefore cannot be used rts ^a test tor potash* 
Vogel observes that this solution is also rendered tuibid by 
^IphatH and nitrate of soda^ muriate of lime, aifd other salts'. 
jBut soda containing some carbonic acid does not alter it, and in 
general the precipitates obtained by alkalies or salts aie very so- 
luble in water, and are taken up again when the solution is exl 
il>osed to the air. Trituration alone wUl eiuible water to take up lb 
grains of camphor pier quart. 



' « 



'On the Qmfposition ofAnmonia, By Mr. Bf.rthollet, Jimior.-> 

Antiales de Vlumiey vol. 67* 

- Thk ohiect of these rcaeairched was to ascertain wlie.her am- 



1 



214 Mr. Tvtiici^B Uethod ofjiiting up an klettrk Cotttmn,^ e, 

ni«nia really contained any oxygen, as Davy had asserted it coD' 
taiued no less than ^0 per cent, oi that gas. 

The expansion oi ammohiacal gas by repeated electric shocks, 
'wliicb separate its elements, was ascertained with the utmosi 
precaution, and 100 ifneasares 6t that gab. were ipuhd to heaug- 
nienied to 294. The expai.ded gas contained 75'5 parts of hy- 
drogen, and 24*5 oi azote. Whence it follows that one Hire 
(quart) ot' aunnoniacal gat, yieldi^ 2 04 Hires of a mixed gas, cora- 
pos'd of I 04 litres ot Lydrogeii, ano 0*5 litres of azote. 

From the data of Biot. and Arrago in their paper on the 
reiructin^ pnviei of gases, it may be deduced that at the freezing 
point of water, and under the pressure oi 0'J(> (30 in ) the litre 
oi hydiOgf u weigh' 0095 grammes, and thai ol azoVe 1 259 g't) 
and iiincLi* nial gab t'i^b gr. ; so that tlie sum ot the weights of 
tt.e hydrogen and azote contained in 6*775 grammeis, or a litre of 
ariimoni'ical gas, is, according to the above stated proportions; 
0'77^ g»ainmes ; which agrees as nearly as possible,* and gives 
the pr< portion by weight as 18*67 oi hydrog^^ and 8ir'13 of 
azote. 

From this accurate expeifimeftt, it fallows, that ammonia fs 
c(>fi;po&ed orly of h>drogen an«l azote, and does no^ contain an^ 
oxvgen, unless at least it can be extracted by some hitherto un- 
discoveicd niethod from those gases which have always be^n looked 
upon as pnie hydiogen and azote. 

1 he mixed ^as collected by passing ammoAia through aH 
ignited tubf oi porcelain, was found to c«>niain the same propor- 
tion of hydrogen and a7ote. In one experiment, 20 litres (quarts/) 
of auiiiioniai gas was decomposed, and evrry precaution taken to 
condense the \\ater thai ought to be lormed if the ammor.iacal 
gns liad contained, as Davy stated, one fifth of oxygen, but no 
^dter was obtained. Neither was any humidity observed in 
the dt coroposiuon of the gas by eieciricity, nor amy signs of 
oxydizeiiient when an iron v. ire v\as used as the conductor, orA 
Ol other i>t which etlectb ought certainly to have been produced 
if the aniiiionial gas contained oxygen. 

OUervafionsj — Mr. Davs has replied to the theory of the French 
chemists, in bis last Hakt^rian lecture, just pBl?lished in the Phi- 
losophical Tranbactioris lor 18-0. 



Ddycriptioti of a Method of filing up in a portable Form the Electric 
Co'umn lately invented by .yJf. J. A. Dl Lue. Also an Jccowit 
of never al t:i:p:rtyie?ih made with it. By Mr. B. JVJ. FoitsT£«- 
FhiL Mug. iSio. ]43. 

In consequence ot the effects produced by Mr. Dc Luc's EI«c- 



\ 



Mr. Forslet^M method of ^ttpig vpan ]E,kctnc Column, Sfc, 215 

l^ric column (which consists of small circular plates of zinc and 
melal paper, alternating in pairs, and connected together by a 
^ilk string passing through them, Mr. Forster was led to make 
soifae experiments op its constiuction and application. 

Two hundred circular plates ot zinc ol about 5.^8ths of an inch 
in (jliameter, and an equal number of discs of Dutch copper leaf 
pasted on pieces of blotting paper doubled, were connected toge- 
ther by meains of a silkjen string passing through them. This 
small combmation acted sufficiently on a very delicate gold leaf 
electrometer to induce Mr. Forster to increase it to 500, using 
silver leaf instead of D^itch metal. The whole wjere enclosed in 
a glass tube, with brass caps, screws, and balls. The series iii 
this state, is termed by Mr. Forster, an Electric Rod. With 
this instrument he pet formed a mimb^r of experiments, 6uch as 
lexhi biting attractions and repuUions on a gold leaf electrometer, 
Dutch leaf, and a ve^y light ivory needle, turning on a point like 
a magnetic needle. And in one case, when the electric rod was 
placed at the bottom of the electrometer, one end being held at 
the same time in the hand, the gold leaf was attracted, which 
shows that the instrument acts through the air. 

It also slightly charged a coated jar. And what* is singular, 
the inside ot the jar, when charged by the zinc bide, gave s gns 
of minus electricity, and the outside of plus^ when excited amber 
^as brought near it. 

The ivory needle vibrated, whjen it was placed bjetween the op- 
posite poles of two rods. ^ 

Three rods combined occasioned a diverging in the pith ball* 
of Cavallo's electrometer, but produced no effect on the tongue, 
as is the case when a single plat€ uf zinc and silver is brought in 
contact with it. 

When three rods \yere combined, and two bells connected witb 
them, having a small brass ball between the bells, suspended by 
silk, a ringing was produced, which continued for a consider^iblc 
time. If a perfect insulator could be Ibund, the ball might pro- 
bably be so adjusted as to occasion a perpetual vibration for 
some years. 



Observaiions. — ^The Electric Column of Mr. De Luc, though 
ijpt novel in its principle, may be considered as an ingenious in. 
strument for indicating the hygrometrical state of the atmos- 
phere. It is only in consequence of a minute quantity of mois- 
ture that it is rendered active for when the paper is thoroughly 
dfied, no ele«^rical effect is produced. 

These experiments of Mr, Forster do not seem to lead to any 
ifaing novel or important. 



•*i 



( v^ > 



mmm 



Qn tie Acids produced by treating Givger Hoot with Nitrie Acid, 
"^ Bj/^. Le Gay Bhewertov. — P/nL J/untal, No. 113. ' ' 

It was announced in the Phil. Jonrn. ^Jo 105, (Retrospect, vol* 
y.) that a new aciil called the zingit)eric acid had been obtained; 
from ginger .Mr. Bi^werton instituted some experiments to exa- 
mine this acid and its comb. nations.' 

- Jam£iica ginger was treated with diluteJ nitric acid, and kept 
at a boiling heat during i2 hours; i$ was then saturated with 
Carbonate of lead, and filtered, and the directions given for obi 
taming' the ncW acid were followed £[& nearly as possible; a 
Whitish salt was obtained in filiform or capillary crystals, which . 
^ere not acid, but nsipid to the taste, ^lightly soluble in water, 
Itnd giving, -with barytic Water and oxalic acid, a dense white 
precipitate insoluble in vinegar. Ihestt properties seemed to 
shew that this/ salt was sulphate of lime. 

The experiments were varied and repeated with similar results; 
and there were no iitdications whatever of the presence of aoy 
tiew acid. ' . • ■ 

When ginger was digested with nitric acid in a more concen- 
trated torni fur some tiriie, then mixed with water, boiled, filtered 
and C(>olecl, prismatic crystals were obtained ; tiaey were intensely 
acid, very soluble in water, and gave with lime water a dense - 
white precipitate, insoluble in vinegar. A part of the fluid also» 
do being artber evaporated,, assumed the appearance of syrupy 
smelled like burnt sugar, was not very acid to the taste, and with 
lime wHwcr, slowly deposited a white flocculent precipitate, sil- 
iiM>st entirely soluble in vinegar : there were also a fevv' prismatic 
crystals visible. These erysrals, Mr. B. conceives, are oxalic 
acid, and the substauce of a syrupy consistence, principally ma- 
lic acid. • . .:.!..- 



uji'.j !l ■ J^yBfr^^ , '*'^ J Uilii 



New eiectro^chemical Researches, on rafious Objects, particularly on 
the metallic Bodies from the Atkabes and Earths, and on soine new 
Combinatums ./ tlydrogenl By Mr, iiujtfPHRT Davy. — FhiL' 
Trans, Fart j] IHIO, 

. Messrs. Gay-Luasac and Thenard suppose potassium and soda 
to be compounds of p'Uash and S'»da with hydrogtl^ and main* 
tain this opmion, by asserliHg that when potassium is heated in 
amiiH nid the ammouiii is absorbed, and hydrogen produced : ott 
heating the olive subsUiDce produced m this experiment, 2-5ths 
6t the ammojHa is ditJeiigagetJ, and the elements, i. e. azote and 
hyd]-»geii, o1 anottier fifth pMrt . by addmg a little water to the 
Residuum, the remaining 2-5 ths of amaionia were obtained, and 



J 



Mr. Davy's nrju Elcctro^chcmical Researrha, HT 

nothing but potash was left. And further, that by reprating thi» » 
i)peration, the^ could produce from a given quantity ot ammonia^ 
ihore than il^ volume of hvdrogpn. 

Ii> proportion, however, as more precautions are taken to pre- 
vent moisture Irom being communicated to the olive substande, 
80 much less ammonia is n-pMuuiced, and ihus as much as 1-1 0th 
of the original quantity was seldom obtained; neither has the hy- 
drogen and nitrogen been procured in the proportion to form 
ammonia, biit the nitrogen has always been in excess, and a 
considerable quantity ot potassium is always revived. 

Bar. 30-2 inches ; therm. 34° Fahr. 3. grains and an half of 
potassium heated in a platina tray in K cub. in. of ammonia in 
U glass retort free from metallic oxides, absorbed 7*5 c. i. and 
'evolved 312 c. i. o( hydrogen. The fusible substance was covered 
"xvith dry quicksilver, and immediatelv introduced into a tube of 
platirik bored from the solid, having a stopcock and adaptor of 
brass, corimcted with the mercurial apparatus; the lube and 
adaptor we^e then exhausted, and filled with hydrogen, of which 
Ibey contained 8 cub. in. On heating the lube slowly to 
Xvbitenpbs, 9 cubVin of gas were given off, and 0*5 c, i. remained 
In the tubf. 0.2 ctib. in. of the gas given off was ammonia, 10 
measures of the permanent gas mixed with 7*5 of oxygen, and 
iacted upon by the electric spark, left a residuum of 7'5. The 
potassium formed, produced, on adding water, 3*3 cub. in. of hy- 
drogen. Whence there is but little difference between the analy- 
sis of ammonia by electricity, or by potassium, but some hydrogen 
app.ears to be lost. 

Bar. as belore : therm. 5^^ Fahr. 3 gr. of potassium treated 
in the same nidnnti, absorbed 6*78 rub. in of ammonia ; and 
2 '48 of hydrogen were generated. The distillation was then per- 
formed, the lube and adnptors being tilled with common air only; 
3 cwU. in. of gas weie evolved, and no doubt the same quantity 
remained in the lub- as ii. tl e former experiment. The evolved 
gas scarcely contained 0*4 cub. in. of ammonia, and the unab- 
sorbable part df^tonated with oxygen in the pi^oportion of 1 1 to 6, 
left as before, 7*5. The regenerated pctabsium produced 2*9 
cub. in. of hydioKen. Here, as before, there is a lobS of hy- 
drogen. 

' When the potassium left in the tube was made to act upon 
Water, a black matter was separated in fine powr^er ; it hHd the 
lustre of plumbago, conducted electricity, took fire at a tempera- 
ture beiovv ignition, absorbed oxygen, and formed pure wat- r 
Svitb it, leaving <>nly mmutply divided'piatina. Of this powoer 
from 4 lo 6 grain- were ii'riiied when 3 or 4 grains of potp^eium 
acted np»' r. .inimonia in a platina vessel, and wa.5 disiilbd in con- 
tact .with LD-.il mrtiil. 

' When an iro» tvhe is en:^)ioyed in tn-atMii! rotassium with 
amtBoma^ liome azote is lo&t; a part of the potassium is changed 



A. 



19 Mr. Dav^i ffea> ElectrOmc/ttmicai Resedrches. 

into potash, and some h)'dr<)gen is produced. In copper tubeii 
more potassiutii is revived ; and the hydrogen bears a small pro- 
portion to thf" azote. In plalina tubes, there is little or no ios^ 
of potassium or azote, but more or less hydrogen disappears. 

5'3 grams of sodium absorbs 9*1 cub. in. of ammonia, an^ 
produced about 4*5 of hydrogen. When distilled, it did not give 
off l-20th of the ammonia that disappeared, but 1^ cub. in. of 
gas were obtained, which consisted or about ^ parts of hydrogen, 
and 1 of nitrogen. Tlie action of sodium upon ammonia is less 
violent than that of potassium, it does not effervesce, hut is silently 
combined with one of the eleraeutb of ammonia, while the other 
escapes in the form of hydrogen. 

Curaudau a(firn^s that the metals of the alkalies are composed 
of the alkalies united with charcoal, and that carbonic acid is 
formed by th^ir combustion, but his metals contained charcoal 
accidentally mixed with them. 

Ritter's argument in favour of potassium and sodium being 
compounds 01 hydiogeiie, is their ex ireiott lightness. — noofteis 
more ecunfy answtnd. Sodium absorbs much more ox^geue than 
potassium, and on the hypothesis of hydro^e nation must contain 
much mortf h^drogene; yel though soda is s^id to be lighter than 
potasb, in the proportion of 13 to 17 nearly, yet sodium is heavier 
than potassium in the proportion of 9 to 7 at least. 

Ritter has observed some curious circumstances relative to telr 
lurium (see p. 1S4) which he conceives to prevent the.metalliza* 
tion of potash, by having a stronger attraction for hydrogeue 
than that alkali. But in reality they contirm the idea of potasr 
sium bting as yet like other metals undeconi pounded. When tel- 
lurium is positive in water, oxygeii in given off; when negative, 
and the buttery contposrcj of more than 300 plates, a purple f)ui4 
separates from it, which renders the water opa(}ue and turbid, 
and a brown powder is deposited; the purple fluid is ^ solution of 
telluretted hydrogen gas in water, which absorbs some oxygen 
from the air in the water, eyolves a little hydrogen, and falls 
djwn as solid hydruret of tellurium. When muriatic or 6|iiphuric 
licid are present in the wuter, the ga? is not taken up. 

Potash, in iis common state of dryness was act^(j upon, hj 
1000 double plates, from negatively electrified tellurium. Ibe 
action was violent, a metallic :iiass not unlike nickel in colour 
wa£ f«rined, which did not inflame nor effervesce with water, but 
changed it of a beautiful purple, and was totally soluble in that 
liquid. The metallic mass was probably a couibiuation of tellu- 
retted hydrogen with oxidized potassium. It effervesced violenti/ 
with dilute muiiatic acid, with a smell resembling that of suU 
phuretted hydrogen, tellurium was formed where it was m contact 
with the air, and muriate of potash remained in solution. 

Tellurium and potassium heated in hydrogen gas, combined 
toother with vivid light and heat, and fqrmed a dark coppef^ 






Mr, X)<iryV new Electro-chemical ResearcJies. 219 

tioloiir alloy with a crystalline fracture, brittle, and not fusibU at 
k red heat. When the tellurium was nearly equal in quantity to 
the potassium, riu hydrogen was evolved by the action of water, 
but the compound of tehurett^d hydrogea and potadh remained 
tiibsolved in the water. 

100 grains of oxide of tellurium, 20 of potash, and 12 of char- 
coal distilled together, yielded much carbonic acid, and an allojr 
bf tellyriHrn and potassium ; a vivid light appeared in the retort 
even before it was red hot. In attempting to* reduce some oxid^ 
of tellurium which iiad probably been prepared with potash, th« 
alkali that adhered to it produced an alloy which was of a gra^ 
colour, very brittle, and more fusible than pure tellurium. 

Telluretted hydrogen gas has nearly the same smell as suU 
phuretted hydrogen, and the analogy of these two substances 
i^ds so great as to lead to a suspicion that tellurium contained 
sulphur, especially as most of the metallic sulphurets which wer^ 
Conductors of electricity, also absorbed hydrogen when made the 
negative Surfaces ; but this idea was after war^ds abandoned. Thfe 
^olbtidli of thi$ gas in water is claret Colour, but it sooti turns 
brown, and deposits tellurium by exposure to air. When newly 
disengaged from an alkaline solution by muriatic acid, it reddens 
fnoisiened litmus, atid after being washed with a little water, it 
loses this property, but it is in this case partially decomposed b^ 
the air in the water; in other respects it resembles a weak acid/ 
Combines with the alkalies, and precipitates most metallic so- 
lutions* It is instantly decomposed by oxymuriatic acid, do*, 
positing a film of telluiium which is soon converted into muriate 
t)f tellurium. It seemed as if tellurium would combine wUh dry 
hydrogen by being strongly lieated in it. 

Arsfenic having an affinity fur hydrogen, it was miade the nega- 
tive surface in water, with 600 double plates, it became dark 
Coloured, threw down a brown powder, but also evolved inflam- 
tiiablcS gas. Wh^n negative in a solution of potash, some gas was 
evolved, the solution became brown, and remained pellucid, but 
an acid rendered it tuibid and precipitated a brown powder. Arse'- 
hic negative in contact with solid potash produced a dark 
gray perfectly metallic alloy of arsenic and potassium, which 
took fire on adding water, yielding arseniuretted Hydrogen, and 
depositing a brown powder. Potassium and arsenic heated in 
hydrogen, were inflamed and yielded a similar alloy. It was at 
first thought that the volatile phosphorus produced by Cadet, by 
distilling acetite of potash with white oxide of arsenic was au 
alloy of potassium and arsenic, but although the potash is dp- 
composed, the volatile substance is nut an alloy of potassium but 
contains charcoal and arsenic, probably with hydrogen; the very 
fetid inflammable gas not absorbable by water which is given otf, 
seems to contain charcoal, arsenic, and hydrogen. 

£asily fusible alloy of tellurium with minute quantity of po- 



C^O Mr^ Dcftvi new ■Ekctro^chemkal Researches* . . 

tassmm aUbve mentioned, lieuled in amaiouia, yielded a dar^ 
brown subhUnce which gave anununia by exposure to air. The 
residual gas contained 4-6ths ot nitrogen a^ote. The residuaj 
gas left in ihe action ot auimonia upon an uHoy of arsenic, aud 
potassium also consisted principally of nitrogen. 

Potassium burned in oxygen gas, upon a piatina ti'ay, absorbs 
J1.20ths of a cubic inch ol oxygen toi every griiin of mutai con- 
sumed, and every grain Of sodium takes up in this manner about ^ 
a cubical inch. The alkalies thus lonned are in a slate of extreme 
' dryness, are only imperiectly fusible at a red heat, and do not, like 
the easily fusible alkalies, give any indications ot luoiscure. 

D'Arcethas shewn that poiaahand soda in their common state 
contain water, and BerthoUel concludes,ihat potash which has been 
fused for some time loses 13*89 pt^i* cent, of water when ii corn-^ 
bines with muriatic acid, and tbat munace of potash contains 
66 6 J per cent of potash, and 33 34 of aiuniiic acid. When po- 
tassium was tiealed with liq*ud inuriatic acid, hydrogen hiilding 
potassium was evolved, and yet 10 parts of poiaosium produced 
17 '5 of dry muriate of ]>otd.'h 5 gr. of potassium abborbedabout 
W cub. in. of dry muriatic acid ga^; 5 of hydrogen were evolved, 
and the platina tray increaaed in weight about V'5 gr. and did 
not lobe any of t-iis weight by beiag i^n U'd. 8 grams of potassium 
absorbed about 22 cub. in. of muriatic acid g^b, ihe tray increased 
in weight 6*5 gr. and about 1-Sth of a grain ol muriate was sub- 
limed. On wabhmg tht; tray, it lo&t about l-3rd K\i a grain, the 
platina having combined with the metal in contact with it. 
Hence the potash in the muiiaie conta.ns 9 per cent, more water 
than that formed by the combustion of pot<tb&iUm, and Bei thoiiei's 
fused potash must contain nearly 23 per cenu of wattr. Jt ap^ 
pears, indeed, that potash kept tor some time in ar^^J heat contains 
l6 or 17 p(^r cent, of water, considtnng the potash trom the coui^ 
bustion of potussmm as the standard. 

Potas&ium and sodium, lannot, tberefore, with propriety, be 
considered as compounds, any more than the other meiaJic 
bodies. 

It has been supposed that nitrogen might possibly consist of 
oxygen and hydrogen, or that it might be composed from water; 
and its formation has often been announced when none of its 
known combinations were concerned: to discover the truth of 
these opinions and assertioils, numerous experiments have been 
made. 

About half a cubic inch of water carefully purged of air, bjr 
the air pump or by binling, was inclosed in a glass tube, and de>. 
composed by means of 500 double plates, so thai about l-8th of 
a cubic inch o\ mixed gasses wt^re produced from 20 to 30 times. 
in every day, and detonated witiiout contact of air, the wires 
bein a hermetically iiiserted into the tube. After ihe first detona- 



Hi' 



J 



Mr. Dcopi/s new EfsctrOmclieniical Uescariiha. fiSX. 

^ioB Uiere was a residuum of l-40th of the volume of thegasses, 
this residuum encreased in the succeeding detonations, and when 
©boyt 50 had been taken, it was about 1-Sth of a cub. in.; 6 
measures of it were found to contain 2*6 ^^ hydrogen, and 3*4 of 
nitrogen. When the apparatus was plunged under oil, the resi- 
duum did not increase so fast as before ; after 340 explosions, only 
0*24 cub. in. of gasses was obtained, b' nieatures of which deto- 
nated with 3 of oxveen left a nsiduuui of less than 1 meas. sa 
that the residual gas was chiefly hydrogen, which njiglit proceed 
from ll.e oxidizement of the platina wires. 

To discover whether nitrous acid could be formed in the elcc- 
triijation of water, slowly distilled water was electrified in platina 
.cones, in a vessel filled with pure oxygen, tl^e cones being con- 
nected by filaments of asbestus, and no arid nor alkali was dis- 
cover<ible ; even wh n nitrogen was present, the production of acid 
or alkaline. n)atter was verj leeble ; but on touching the asbestus 
with unwashed hands, or* introducing the smallesi particle of 
neutrosaline matter, the j)rf;.luction was immediately evident. In. 
other experiments iu wjijch only glas^^, water, quicksilver, and 
platina were present, the gasses produced from the water were 
collected under quicksilver, and the two portions of water com- 
municated directly with each other; tixed alkali was separated, 
and* an acid which rendered nitrate of silver turbid. As perfectly 
dry common salt is not decomposed by silica, perhaps arid 
muriatic acid may exist in glass. 

When platina was melte^ by Voltaip electricity in a mixture 
of steam and oxygen, no nitric arid was produce(J, unless nitrogen 
was also present, and then it was formed. 

Steam, passed through ignited oxide of manganese, produced 
sufficient nitric acid to render the condensed water disagreably 
sour ; it is probable that this methV)d may hereafter be applied 
ttt the manufacture of that acid. No acid was produced by 
passing the steam over red oxide of lead, but the experiment was 
only tried once, and the porcelain tuoe was small. 

In order to examine rigorously Woodhouse's experiment of the 
production of ammonia from a previously ignited mixture of char- 
coal and potash, by the addition of water, one part of pure 
potash, and 4 of charcoal were ignited in an iron tube furnished 
with stop-cocks, and connected* with a pneumatic apparatus. When 
water exhausted of air was brought in contact with this mixture 
when perfectly cool, and afterwards distilled from it by a low- 
heat, it was found to contain ammonia; the quantity or this 
alkali was diminished when the mixture was again ignited, and 
was barely sensible in the foqrth repetition. On adding tresji 
potash, the mixture yielded ammonia for 2 or 3 successive times, 
but when the mixture had ceased to yield ammonia, the power 
was hot restored by cooling in contact with the air. Copbider* 
No. 24. — VOL. VI, 2 G 



/ 



22^ Mr. DcPCy^s new ^lecfrchchemical ^aearcies* 

able more ammonia vfixb produced when a mixture was cooled in 
contact with the atmosphere, than when in contact with tb'd 
gas produced in' the operation, which is agaiiist the opinion that 
nitrogen is produced in ihis( process, bul nothing can be de ter- 
minf^d till the' weights of the products are known. 

About 1;25 Cub. in. of siioW water that had been boiled, being 
frozen and (hawed 16 times successively, ga^ was produced in 
ihe first 3 or 4 freezmgs, but afterwards it did hot seeiii 16 
Increase; at the end l-50th of a cubical inch of common stir re- 
mained. 4 cub. in. of snow water frozeiir 4 times in wrought iroii 
yielded l-20th of its' bulk of gas, which contained l-lOth of 
oxygen, 3 6f hydrogen, and 6 'bf nitrogen. - 

In repeating Kirwari's experiments, 5 cpb. in. of nitrous gas, 
and 5 of sulphuretted hydrops n were mixed' over mercury, bnr* 
29'b in.; thei m. 51'* Fahr. 12 hours elapsed before any change took 
place; a whitish prec'ipit^ite was theifi formed, and deep yellbw liy- 
dro-sulphuret of ammonia with excess of sulphur began to appear 
in drops in tfie inside of the jAr ; after two days, dnly 2 3 of ga^ 
femained; bar. 30 45 in. and therm, 52** Fahr. 3«4ths of the gas 
was nitrous o.^ide, the remainder was ' inflammable; so tliat 
no nitrogen was formed, but only two new compounds, one formed 
of nitrogen and hydrogen, with oxygen and sulphur, the other of 
nitrogen and oXygen in a more condensed state than b^foi*e. ' • 

A Item ptS'Werte also 'hnade to decoibp6uiid nitrogen. With this 
viewy about ^ or 3 grams of potassium on a platina cup^ 
in £ri^out i^ cubic inch of nitrogen, were exposed to the action of 
1000 double' plates, ' an intense white light v/as produced, the 
potassium was volatilized, and the electricity passing through 
its vapour, produced a moHt brilliant flame ; the vapour seemed 
to combine with the platina whrrh was thrown otif in smalt 
Ijlobuks, as when iron is burned in oxygen. - Hydrogen was 
evolved, and sometimes a loss of nitrogen took place, but in. pro^. 
portion a^ the potassiuni was freer from a crust of potash, so 
much less hyirogen was evolved. When great precautions were 
used, the hydrogen did not equal 1 Sth of the volume of gas, an^ 
no nitrogea was lost. The greatest loss of nitrogen was 1-1 1th 
of the quantity used, in this case, the crust of potash was con- 
side able, and hydrogen equal to 1.4th of the nitrogen was pro* 
duced It therefor^ seems probable, that the nitrogen combines 
with nascent hydrogen, and is separated in the gray pyrophoric 
sublinrmce which is always produced when potassium is treated 
wifh amni'^nia by electricity. 

Phofcphiiret of lime conducts electricity, and when placed 
between the wires of the great battery burned with a most 
iniense light. On being igriittd to whiteness in nitrogen, a little 
phosphuretied hydrogen was evolved, but ihe nitrogen was not 
altered. ' ' ' " ' 



t i 



I 

I I 



., ifn Dfftn^s netD Eleetrfy-ckemtcal Retee^ches. 22S 

4 > When a. mix iM re of nitrogen aod o?^y muriatic acid gas was 
j)assed through an ignited porcelain tube, there was a small loss 
of nitrogen, l?ut the, gas came over very cloudv, aqd .the water iii 
the apparatus was found to contain nitrpmuriatic aci^.. 
. The result of th«^se in<|uiri^s do not strengthfn the suspicion 
formerly, entertained of .the decomposition of bitiiogen, by the 
distillation of the oli,ve substance from potassium t^nd ammpnia 
in iron, tub'is, especially as a small quantity ofo;qide might adher^ 
to tl;ie Vk elded parts, the oxyg.en of which would unite ,with hy- 
drogen, from the olive substance, and being condensed in th^ 
^pper p^rt of the tube, would in the end occa.fion the formation 
of ammonia, and probably its absorption, the coi!3equent loss ,of 
nitrogen, and increase pif hydrogei). 6 grains of. pptasj^ium in ail 
;ron tray, jn a tube used imuiedjately after its interiial surface 
had. beep cleaned by, the borer, absorbed nearly l3 cub. in. of 
ammonia, and produced about 5, of hydrogen. , About 1 cub. in. 
of ammonia, 4 of nitrogen and 8 of hydrogen were evolved in the 
first . operation; and 2*5 hydrogen, with I'l^ of qitrogen w^rfc 
given, off iii the second ; the potassium produced generated, only 
3*1 cub, in. of hydrogen, tt is probable that ,th|s apparent loss 
of potassium arose froni,. its becoming alloyed with the iron of 
th^ tube ; ^nd in an experiment of ibis kinl, the tube was lined 
;with a thiii filni^ of potash j and oh be mg iinhiersed in water^ 

yielded 2*3 cub^. tn. of hydrogen. , ,. , 

,, From the loss of weight oc(^ui*riHg in the electrical analysis of 
kmnionia^it w^s concluded that water or oxygen was separated 
in this operation; and lh« production of an amalgam from, ami 
monia, which regenerated anjrnoiua, apparently by oxidatiod, 
coniivmed the existence of oxygen in t)iis substance. Ammonia 
was introduced iqto a glass globe, which had been exhausted afteV 
^ing ^lled 2 or 3 times with ammonia, and on being decomposed 
by electricity, there wbs no loss of weight, nor any deposition of 
hioistufe, but the wires were tariiished, and when brass was lised, 
a small quantity <S olive matter formed on the metal, yet 
although 8 cub. in. of ammonia were decomposed, the oxide 
scarcely affectec( the balance. On reducing the temperature to 
15^ there was a feeble indication of by gronietical moisture. The 
gas increased from lOO to 185 within a range of 5 parts, •Am} the 
hydrogen was to the n«tiogen on the average of 73*74' to 27*26\ 
Now 100 cub. in. of nitrogen dried by long exposure to potash, 
weighed 29^^ gJi^ins, bar. 26'!i in. therm. 61° Fahr. the same 
quantity of hydrogen, 227 gr. and of ammonia, 18*4 gr. whence 
there was. a loss of from i-12th to 1-lBth in the analysis of am- 
monia. This loss of we ght is most probably nothing more than 
is to be expected in such delicate processes. 

The principal difficulty is to determine the nature of the matter 
existihg in ihe amalgahi of ammo.iia, and what is the metallic 



\ . 






1 



2C14 Mr. Davy's iieiv ElectrO'ehemcdi Resedrchesi 

basis of ammonia. The anidl^am seems to preserve a quantity 
of waiter adhering to it, which inr^y be sutficient to oxi>iise Hak 
metal and r^^proju* ^^ the amn onia. The amalgam cannot b^ 
formed from anunonia in .; dry 5.<i«e The amalgams oi potas- 
sium, sodium, or bariu;n, do not prodice it iA ammoniHcai gas^ 
and when heated with murine of ammonia, the alkali is nqt 
metallized, unless the salt is moistt. When ammonia is acted 
upon by metallic amalgams negntively electrified, the effect is less 
distinct than with pure quicksilver. Quicksilver exposed to *2(/* 
Fahr. yielded a more scMid amalgam than uswal, but it decomposed 
as rapidly as the comnion, and yielded more gas, so that once G 
times its volume were obtained. The solid ariialgam of potas- 
sium quicksilver and ammonium, can probabhy be obtained the 
freest from adhering moisture, it decompos s very slpwly^ evenf 
in contact with water, and when well \t'iped it bears- a consider- 
able heat without altfration. When strongly heated in a green 
glass* tube filled with hydrogf^n, ammonia is partly regenerated/but 
with this ammonia there is from 5 to6-10ths of hydrogen pro. 
duced. On account of th^Tvariation in the moisture, it is difficult 
to determine the ratio that would exist between the hydrogen 
and ammonia if no more water were presciit than would be de- 
composed iu oxidising the basis. It was never less than 1 to 2, 
and often more; whence^ supposing ammonia to be an oxide, it 
hutst contain about 48 per cent of oxygen. Even in common* 
air, the amalgam evolves hydrogen and ammonia nearly in those 
proportions, atid il does not appear to absorb oxygen from !he 
air, for although the air to which it had been exposed^ was for- 
merly tound to give less diminution with nitrous gas than before,' 
this differencie might have arisen from tlie mixture of hydrogen. 

If hydrogen be supposed a simple body, and nitrogen an oxide", 
this last Would consist of nearly 48 oxygen and 34 basis ; but if 
liydfogen and nitrogen arfi both oxides of the. same metal, then 
liitrogcii contains less oxygen. But, if \iie facts co?ncerning am- 
monia are considered, abstractedly from tffe other general phe- 
liomena of chemistry, iliey are best explained on the liotiou 
of nitrogen » being a basis which becomes alkaline by one dose of 
hydrogen, and metallic by a greater proportion. 

The proportion of matter added tt) the quicksilver in the 
amalgam was stated as l-r200Qth part, on' the supposition, that 
the quicksilver gave off only 1*5 its volume ofam:iionia, which i^ 
the minioiuiu.. Oin the preceeding statement of 6 times its balk; 
the amalgam will, >n the antiphlogistic hypothesis, contuio about 
l-1600th of ne.w matter, and on the /^A/og^^/c, about i-gOOth. 

As to the metallizatiou of the earths. When iron was nega- 
tively electrified by 10()0 double plates and malted in contact 
with silex, alumine, or glycine slightly moistened and placed ia 



.»|*iB^sp-5r.,:;'?:>^4^. 






■-."tfaE 



A 



Mr, t)axi/snew Eleetro^chemcal Resedrckes, f 25 

fcydrdgen, the iron berame brittle, and whiter, and deposited the 
fcarib on solution in an acid. 

*Fonr grains <»f potassium sublimed through 10 gr. of silex# 
heated to whiteness :n a platimi tube, evolved no other gas, hut 
"what might be referred to moisture adherent to the crust ofpotashc 
The potassium was entirely destroyed, and glass with excess of 
alkali was obtained ; this on being powdered, exhibited dark 
•pecks, of a dull metallic appearance ; on being flung into wat^r^ 
there was only a slight effr^rvescenre, but on adding muriatic acid, 
gas was slowly disengaged, so that it is probable the silex had 
been disoxygenised, and was slowly reproduced. 6 gr. of polasr 
sium, and 4 gr. of silex being employed, a part of the result took 
fire as it was taken out of the tube and left alkali and silex, the 
part that did not take fire was similar to that obtained in the 
preceding experiment. 

Potassium acting upon alumine and glycine, produced more 
hydrogen than could be ascribed to the crust of potash, so that 
it is probable that they contain water, although previously ignited. 
The residuums were dark gray pyrophori, which emitted brilliant 
sparks when burned, and left alkali and earth. They were rapidly 
decomposed by water. When naphtha was introduced into the 
tube in order to prevent their combustion, they were found to be 
very friable mabses, with small • metallic particles which melted 
in boiling naphtha. 

On introducing quicksilver, while the tube was hot, and the 
potassium in excess, amalgams were obtained, but they resembled 
the alkaline amalgams, and although a white matter separated 
from those of glycine and alumine, during the action of muriatic 
lieid upon the atiiaigam, yet the existence of the metals of the 
earths in them was very doubtful. 

Mixtures of the e&rths, potassium and ironfilings being ignited, 
whiter and harder metallic alloys of iron were obtained, which, 
when treated with acids afforded the earths made use of. The 
alloy from silex was brittle and crystaUine, from alumine and 
glycine imperfectly malleable. 

Solid amalgams were obtained by passing potassium through 
lime and magnesia, and that from magnesia was easily deprived 
tf its potassium by means of water; the amalgam was then 
"white, and when exposed to the air, hecan)e covered with a 
dry white powder ; treated withjrnuriatic acid, it yielded hydrogen, 
And produced a solution of magnesia. 

It is probable that these alloys of the common earths may bo 
formed iri metallurgical operations, and that small quantities, nt 
them n^ay Infiueace the pro^perties of the compouud in which 
they exisrt^ thus Berzelius says that copper is hardcoi^d by 



it^-^k: _ ' '■' ^* 



-"H 



5^5 3f/% Dax^ys new Blecira-chimkal ResedrcM. 

If we allow the attraction of acids to salifiable bases to U 
inversely as the quantities of oxygen that they contain, and thai 
this attraction may be measured by the quantitieb of bases whicli 
any-^cid dissolves, it would be easy to infer the compositioD of 
the base. On the faith of the most accurate analyses ot the 
tieutral salts, bavytes must contain 90 5 per rent of metal, btron- 
tites 86, lime 73*3, magnesia 65, and alumine about 56. Bewe- 
lius says he found silicium in cast iron, and that on being oxi- 
dized It took up nearly half its weight of oxygen. On the prin- 
ciple just stated, silicium ought to contain the largest pioportioi^ 
of oxygen, and ammonia should Contain 63 per cent of metallic 
matter, and 47 of oxygen. 

The alkalies, earths, and oxides have been generally cof.MHerej( 
as separate natural orders, but the more the sul»jt'ct i? ♦^nquire*! 
into, the more distinct will the general relatiuti of all uifiallic 
Substances appear. 

Hydrogen combines with the lara^est proportion of ox\^en, and 
^et forms a neutral body, so that it should he tinhui inore ut^, 1y 
positive than any other body, and if an uxai. , not i k^ lobe 
decomposed by simple attraction. As it forms a bubataiuv a[>: 
preaching to an acid when combined with telluriunr^ or 5ui)»hur, 
it is probably neither a gaseous metal, nor simple; nor exists m 
its Common form in amalgam of ammonia. And ,when in lutro* 
inuriatic acid, the nitrous acid is decomposed to form a metallic 
muriate, nitrous gas, a bod} highly oxygenised, is emitted. 

If hydrogen is found to be protoxide ot ammonium, ammonia 
the deutoxide, and nitrogen the tritoxide, the theiwy of chemi&try 
would be simple, and the existing arrangements >vould harmonize 
iK'ith all the new facts; but explanations may be found, which, if 
not so simple, account for the phenomena, with at least equal 
tacility. Hydrogen may be considered as the principle ol in- 
flammability i the cause of metalliaation, and with oxygen the 
only simple body. Metals and inflammables as compounds of 
hydrogen and unknown bases, the earths, fixed alkalies, metallip 
oxides and common acids as t-ompounds of those bases witb^ 
water. 

The properties which seem to be inherent in certain bodiesy^ 
and which are either developed or concealed according to the 
nature of their combinations is a strong argumept in mvour of 
the last notion. So also is the greater facility with which oxides 
are reduced when hydrogen is present; thus,' when fused litharge 
%»^ as electrified by 600 double plates, there was effervescence at 
the positive side, and a black matter formed at the negative, yet 
tio lead was produced ; but when nwistened litharge, or a solution 
of lead was eiaploycd, the metal was rapidly formed- Again, hy- 
drogen and ox^'^en seem in oil ca^eaf to Aeutraiise dach oibe£» 



f 



iir. T^cccyU new E(e(fro*ciemkaI 'Researchei'. 2^7 

and of course should, as is really the case, most distinctly dis* 
play, in combustion, the mutual ^^nergy of the bases. 
' Potassium, sodium, and all metals hitherto tried, evolve the 
same qunrtity of hydrogen, when treated with niuriatic acid ga?», 
*and all form dry muriates, so that if the existence of water in the 
potash f rmed in muriattc acid gas be allowed, it must also exist 
in the oxido^ of metals tormed m similar operations. 

The difficulty of finding any multiple quantity of oxygen which 
may he supposed to exist in hydrogen, that' might be applied ta 
Explain the comp«»siti6n of nitrogen from the same basis, is 
against thte antiphlogistic view of the subject; but the compo- 
sition of the tnetal of ammonia from hydrogen and nitrogen, or 
'of a metallic sulislance, from substances not metallic, is equally 

contrary to the general tertour of chemical reasoning. 

i ■..'...■■ 

I ■ ■ H ill 

The electrisation of sulphur and phosphorus goes far to prove 
that they contain combioed hydrogen. From the phenomena 
they exhibit with pt»tussium; they seem to contain bxyged, parti-* 
tularly the vividrtess of the ignition, but tellurium and arsenic 
Txhibit the same phenomenon.' I'he phenomena in the action 
of potassium upon stilphur and phosphorus, Sulphuretted and 
phosphu retted hydrogen vary 'accoraing to circumstanws, and ^ 
Sometimes potassium 'yields more gas after it has been exposed to 
these bodies "than it would give alone; That sulphur and pbos« 
pborus are nonconductors of electricity is" one evidence of their 
containing oxygen. * Potassium and sodium heated in hydrogen 
inixed with atnibspheric air", iabsorb both oxygen and hydrogen, 
^ivi become nonconductors i 

When sulphuretted hydrogen is decomposed by common elec- 
tricity, its volume is slightly diminislied, and the sulphur is 
whitish ; by Voltaic electricity, its volume is net altered, and the 
^ilpliur is as usuhI ; hence il it weighs 35 gr. per 100 cub. in. it 
will conrain $*27 of hydrogen, and 34*73 of sulohur. When ar- 
' geniur^tted and phosphui^eltcd hydrogen were decomposed by elec- 
tricity, their volume was not changed, the phosphoras however, 
was dark coloured, and the arsenic brown. Wh«m a small qoan». 
tity of potassium a'ts upon these gases, their volume is expanded, 
so that it is pn>bable they contain in equal volumes, more hydro- 
gen than sulphuretted hydrogen. 100 cub. in. of pho^phuretted 
bydrVigen weighs about 10 gr. at a mean temperature and pressure, 
und the same volume of arseniuretted tiydrogen, about 15 grains; 

Ohservaf ions, -^The preceding iidkenan lecture, although it H'ds 
considerably to our knowledge of the subjects oper-ited up«»n, » oes 
fiot altogether remove the dithculty which embarrasses the opmionti 
that may be formed f expecting their composition. 



^ 



ddS Mr. Daa^$ neu> Ettctrohchemical Ruearckti. 

Mr. Davy treats Ritter's argumeut concerning the lightness of 
the new metals^ being io favour of their containing hydrogeni 
with great disdain, and informs us, that '* no one^ is more easily 
answered ;" l|ut it would have been better to have entered some- 
what more psirticularly than he has done, into its confutJitioD. 
According to our conception of Weiss's account of Ritter's disco^ 
veries, of which an abstract w«s given in our last volume, and 
the continuation of it in the present number, Ritter observing 
that the oxides of the common metals are all speciSeally lightfr 
than the metals theuisfJves, as might be conceived from their 
union with a lighter substance, viz. oxygen, was led to suppose, 
that as the tixed alkalies are specifically heavier than the metaU 
produced from them, it was improbable, that they were the ox- 
ides ot those metals, but that the latter were more probably a 
combination of the alkalies with some lighter substance, namely, 
hydrogen. Ap argument which certainlj^ appears, at first sight, 
to possess considerable force : for although the specific gravity 
ef a compound is not exactly the mean of that of its constituent 
ingredients, yet, that a compound should be much denser than 
the densest of \U ingredients, is certainly a very rare case. 

Bat is this rare case that of the supposed compounds in quee-i 
tioo ? is oxyg/en, coiiisidered as a solid, less dense than soda or 
potass ? We answer, probably not. Let the weights m and n of 
two substauces, having the specific gravities a and 6, be mixed 
together, setting aside the consideration of any condensation: 

then the joint bulk of the compound will be — h t ~ \ 

and its specific gravity, being represented by the weight divided 

by the bulk, will be — zz c, and (m + n) ab zz mbQ 

MO -\- na 

4- naCy whence b z^ . Now let its suppose, 

■ ' {m -J- 7/) o — . fttC ^ rf y 

that th® specific gravities of oxygen and hydrogen, as they exist 
ill water, are in the same proportion as in the gaseous state, 4hat 
)s, nearly as 14 to I; then m being 6 , » J, c i, and a zz: I4bp we 

I 20 

liave gSbb zz: 6b + 14, 986 =z 50, * = 77 , and ba zz -z 

zz: 2'S6 for the specific gravity of oxygen : or if we make th^ 

disprofiortion but half as great, and a =;= 73, then 49 bbzzbb + 7^* 

J 3 ]3 

6 zz — , and a zz — zz rS6'. We have, howevier, a more di- 
' 49 7 • ' 

rect mode of computation from the specific gravity of the vitre- 
ous oxide of antimony, which is 4*93, while that of the metal is 
6*^99 the proportion «»f its con)ponent parts being nearly that o( 
100 to 23: her€ m =z IQO, n zz 23, a zz 6 89, and c == 4 95, 



#* 



whence 6 is founxl 2*23. And^n the whole,' allowing fortsome 
.iincerttainty in the elements of the calculation, it .is highly pro. 
bable, that the specific gravity of solid oxygen eugbt to be e»ti« 
inated as being within the limits of 3 and 2*5. But Hassenfraie 
tnakes that of soda only 1*^4 ; and we may fairly set dowu the 
Specific gravity both of potash and of soda as decidedly lower 
than 2, It is true, that there must still be a very considei-able 
condensation during the conversion of .potassium into potass by 
'Combastiofi. Bur where -is the improbability that a great coiu 
idensation should be the effect of a very violent attraction ? 

Mr. Dayy, in eomnioh with the greater m|mber of moderik 

^authors, at'vi'ays lis^s the epithet ^* phlogistic" to denominate the 

theory in which hydn^n is held to be the principle uf intiam. 

ifnabiiity ; but this denomination does not appear to us to be 

Strictly accurate. I'he phlogistic hypothesis properly denotes 

the common theory of combustion of the oldest chemists, in which 

the phenbtnena of inflammatiow, A:c. were explained by the escupe of 

an unponderahle fluid, under the names of light, iire, piilogist«)n, 

or some similar appellation, and which, as Stahl was the iir$t 

elementary aulhor on general chemistry, who shewed the full 

extent of its application, is called frJom him, the theory of Stahl. 

Lavoisier appropriating to himself the discoveries of Hook and 

*Bayen; attempted to overturn this doctrine, and establish his 

own antiphlogistic system on its ruins. One of his opponents, 

Kirwan; took as it were a middle course, and- conceived. hydrogen 

to be the principle of iiifl-ammability ; but although this was in 

'opposition to the antiphlogistic system, it still differed essentially 

from the older Stahlian doctrine, and should not be called by the 

'^ame naUtte*. 



JM i ,i__LlL- ! I ■ "I '■ .Iji H 1 ■! 1. J, .' » .i. .f 



Anaiysis pf Augite^ Mtlanite, Staurotide, Labrador Hornblende, 
shifrloijts ^Beril^ reddish -Muratian Tourmaline , S^ Mr, Klap- 
KOTH. ^^Annales de Chimie, 

Black atrgifte (pyroxene or volcanic schorl) is found in very 
£ne crystals in the fissures of Mont Latin near Home, and in the 

'neighbourhood of Fratcati. It is easy to break, and the tritu- 
rated' powder is greenish gray* its s^cific gravity is 2, and the 

' bldwpipe merely founds the comers and edges. It does not meit 
With twice its weight of carustic potash, but merely forms a 
broMTn mass which gives to water a light green colouri* 
• Til is augite contains 48 per cent of silica, 24 of lime, 8 '75. o£ 
knagnesia, 5 of ahimine, 12: of oxide of iron, 1 of oxide of m^angsi- 
inese, 8k)me traces of potash, and^ r-25 were lost; Mrhich analysis 

^pp roaches. very near to the^tatiementof Vanqueliu. 

■^ '-Melamte ,(black. gatrneO ^ives a brawnish or blackkh. gray 
Ko. 2-i.— Vol, VI. 2 h ^ 






J 

£4. 



!Ufd Mr. Klaprtdh's jlnMym o/Ju^e; iitkmtt. ^i. 

powder. Us 8(»ecific gr -vity is 3'7. It undergoes scares Sttt 
alteriition when ignited in a cracible, but the blowpipe reduces U 
slowly to a pearL It contains 35*5 per cent of silica, 32*5 d 
lime, 6 ot duMiine, 24'25 of oxide (»t iron^ 0*4 of ox\6e oi inatv- 
ganese, and 1*35 were lost; which analysis is conibrmable i& 
that ot Vatjqueiin. 

The analysis lormerlv made of 'pyrop, or Bohemian garnft^ 
has been quoted in several French books^ as being that of meh^ 
Bite. 1 hore has been iound iu Boh«mian garnet 2 per ceni. d 
chromic acid. 

Black staurolite (grenatite) from Saint Gothard is deep brown* 
isb black, in large or titiddie size cryt^taU, ahiiost alHong, which 
are eitrier imbedrled b(»litarily, or intersect each other in the iorm 
of a Sa.nt Andrew'b cro&s. The surlace is fine grained, but al- 
most always scaly ; it id bin slightly briKiaot externally, in tli« 
internal parts, the Instr^ vaiiPS accordiitg to the grain, being 
either "very brilliant, or between resinous and adamantine, its 
specific giavitv is 3*51. it is not changed in colour, weight, or 
form b\ calcination. It was found to contain 37*5 per cent of 
silica. 41 of alumiue, i8 26 of oxide of iron, 0*5 of magnesia, 0*5 
of ox ie of manganese, and 2*25 were. lost. 

Reo staurotide varies from brownish red to reddish brown ; it 
Is usual iv iuirulated in mica slate on Mount St. Gothard, and 
very rarely crossed. Its surface is smooth, and its lustre rather 
resinous. It is trequently crystallized along with kyanite, so 
closely that they appear only one substatKe ; in this ease, the 
i^taurotide is slightly traru^iucid at the end of the prism Its spe- 
cific ^avity is 3*7^)5, ami it contains 2? per cent of silica, 52'2d 
of aiumme, 1&*5 of oxide of iron, 0*25 of oxide of manganese, 
and 2 veie lost. 

Brown staurotide of Quimper in Morbihan, and that of Finis, 
ierre connect the two former varieties. This variety is usually 
found in rectangular or obliquangular crosses; both the prisms 
ilire trequently of the same s ze, but one is sometimes much less/ 
and appears to have been imbedded in the other. 

Lab ador hornblende was formerly confounded l>y. Uaay with 
metalloid oiallage, or bronzite, but he lias siiice made it a dii- 
tin( > .>{>ecies under the name of hyperstene, in reference to its 
superior haidtiess, and specific gravity, when compared with 
borobl^nfie. Its colour is n^aroon brown p, assing to brownish 
blaick, internally it has resplendent spots whose brightness is 
augm'^rred by being poiisbed and whose colour is a medium 
between 0(»pp«r brown, pinchbeck brown, and gold yellow. At 
pi*esent it has only been found in fragments, so that its form is 
uj)known. It has a semimetallic lustre^ is very distinctly lamel- 
lar, ^^^ ^^ fiakes cross each other in two directions, at angles of 
^(f aitti. iOO^ It breaks into l^eof^ «hftpe fragment. It is 






.3>. Kfaproih's Jnah/m ofAvgUe, Melanite^ SfC. tSl 

•pake, aud yields greenish white scrapings. Its specific gravity 
16 3.390. It is not fusible by the blowpipe, but iis seminietallic 
lustie turns blackish. The {lewder of tfaid stone beings; calcined, 
k^fees^one per cent, of iis weight, and becomes of a deep a&h gray 
colour. Jt contains 54*^5 per cent, of silica, 14 of magnesia, 
2' 25 of alumine', 1*5 of lime, 24*5 of oxide j>f iron, I of water, 
6ome traces of oxitte of manganese, and 2*6 .were lost. 

The analysi? of the ^iaagenst«in, orpyenite of Hauy» fo^pd at 
Al ten berg, mixed with quariz and nuca, formerly made, was 
y€sry supeificial, and does- not deserve Twuh consid«*ratioii ; the 
stone has therefore been analysed atres'h, partly tu find it it c»n- 
tained any glycine, because it had lately been called by the name 
4>f chorions beryl. It diHPeis, howevei, vf*ry ranch from beryl, 
which loses one fourth of its weiglit, so that it has a greater ana- 
logy to topaz. Bncholz first discovered that this loss was owing 
to Huoric acid, which has been confirmed by V'anquelin, who 
found 3^5 per cent, of lime in this stone, (the editors of the Aii- 
nales add in a note, that the specimen examined by Vauquelin 
tvas not pure): this has not been observed by others. Bern- 
hardi has made several rnineralogical observations, which concur 
in shewing that it sht-nld rather be called schorlous topaz. 

This stc»ne, heated in a crucible, yielded a whitish vapour, but 
it underwent very litlle change, and lost only one per cent, la 
the porcelain furnace it became gray, dull, and rough on the sur- 
Ikce, with a very considerable l(»ss of weight. On being distilled 
in a luted glass retort, il yielded only clear water, which did 
not redden litmus paper; but on distillation with once and an 
half as much sulphuric acid, the neck of the retort was corroded, 
atid a moist siliceous sublimate was obtained, but not so abtm^ 
dantly as from topaz. On analysis the stone was found to con« 
tain 43 p«^r cent, of silica, 49*6 of aumine, 1 of, oxide of iron ; 
ao that allowine; I. as above, fnr the water, and I'A- for the 
«isiial inevitable loss, it should contain about 4 per cent, of fluoric 
acid. 

Th€ reddish prismatic or needle like stone found in Mount 
Hradisco, near Roczna, in Moravia, imbedded in corppact with- 
t3b gray quartz, or m lepidtilite is peacii flower red, verging in 
«<>me places to greenish yellow, and white gray. As it ks found 
immediately • under the lepidolite, Ebtiier has descrit>ed it under 
the name of crystallized lepidolite ; but as it differs ^y its cbe* 
mical characters, it was afterwards considered as schorlous beryl 
or stangenstem. Hauy arranges it with the red Siberian schorl 
<>r siberite, under the name of tourmaline apyre, as it is not fusi- 
ble by the blowpipe upon charcoal, but merely becomes chalk 
■whitfi. Heated in a crucible, it loses 1*25 per cent of its weight, 
with scarcely any other alteration. It contains 4^*5 per cent, of 
silica, 4i3^25 of alumiue, i*^ gf oxide of mapganese,.0-l of lime. 



■^^ 



232 Dr. John's Analysis of Minerak. 

S of soda, l*Q5 of watt-r, and *2 4 were lost ; hence. Hauy i? coni* 
plettl^ justi^N'd in his classing it with siberite, which, accordiug 
to n i^le analysis by \'&\ qudm, contains 42 per c^nt. of silica^ 
iO r: aluniitit, 7 of slightly ferruginous <^xidc of manganese, iCf 
of soda, while 1 was lost. 



.^^xx. 



Analysis of' some Minerals knotcn hy the Is^ame of Talc. By Dr. 

JoH^i. '^Annalcs de Chimie, loL 67. 

Wii^K INiitchel gav^ the name of magnesia to the carbonate of 
magnesia foynd at Rovina in Moravia, it became necessary to de- 
signate the mineral which Werner had described in his translalioo 
of Cronsledt, by another name, and the name of earthy talc was 
applied to it. Vauquelin has given an analysis of a mineral un. 
der this name, in which he found no traces of magnesia; but as 
the sam^ name frequently denotes different minerals in France and 
Germany, it became necessary to examine the authentic speci- 
mens described by Ileuss, in his new system according to Wer- 
ner. 

White earthy talc, of f reyburgh in Saxony, is little affected by 
the blowpipe, but at length it melts in some degree, and the point 
of the flame in contact with it, is tinged of a fine sapphire blu^ 
colour. Microsmic salt dissolves very little of it. Glass of bo^ 
rax dissolves a very large quantity with great ease. Heated in a 
crucible, it was not altered, but it lost 13'5 per cent of its weight- 
'it is soluble in nitric or muriatic acid, without any efl'ervescence v 
the concentrated solutions take, on cooling, the form of a firm: 
jelly. Concentrated sulphuric acid, forms i combination resem- 
bling starch glue ; when water is added, a solutioiji takes place^ 
and a little sulphate of lime is left. It contains 81*75 of alumine, 
13 5 of water, 0'7q of magnesia, 4 of lime, and 0*4 of potash ; so. 
thai the* e was an excess of 4 part. These results are sur- 
prizing, and t(ie mineral must be looked upon as native alumine, 
even purer tli an that found at Hall. 

Yellow earthy talc of htiefelburg, near Merow/itz, in Bohemia, 
was calcined by the blowpipe to brownish red, but did not melt. 
It dissolved in borax and microscosmic salt ; the pearls were 
transparent, and yellow when hot, but lost their colour by cooling. 
Hiaied in a crucible, it became cinnamon colour, and lost 
5 per cent of its weight. Nitric or muriatic acid act very 
slowly upon this stone. Nitromuriatic acid takes away its colour 
without diminishing its lustre or greasiness. The acids take up- 
a little alumine an<i iron, Siilphuric acid does not diss<»lve it. 
Heated wi»h soda, it forms a grayish substance which does not 
melt in a silver crucible, but is completely ^»luble in water; this 
solution being supersaturated with muriatic acid becaxBe clear,* 



J/r. Buriecjf o» the Profiis of Wilt^ire Menno Crcss'-Sheqy. 23;Sf 

^od when rvapora*ed exhibits the presence of siUca. It.contains 
'jG0*2 per cent (*r silica, 3Q*83 of alu'iin's !i 55 of oxide of iron, 5 
of water, some tiaces ot ii ise, and -42 ^vere lost. 

Ironi these analyses il aj'jien!^, tiiJit neither of these minerals 
can any long'T be let in the niaj.n ^an genus, if any regard is 
to be paid to ihe conbtituont pa! ts of fobSils in their arrange- 
ment. 



OAsTrivz^o//.?.-— ilo'vever swrpU/pd Mr Bucholz, who communi- 
catfJ this |- '.^jt;.-. .nay iMvf l'«en, we see nothing in it to excite 
aiiy w« iiut-r. i i*<- soiifr niHU-Mils of- the class of earths in the 
system ot Werner have always app^-arrd to us a mere mass of the 
mobt inextncabl« cont4isi«ii. Indeed ^ve iiave little or no hesita- 
tion in siying, t4jdt, aLbo'^b our knowledge of stones has been 
gjieatly increased of l^te, the earths, as they are commonly called, 
have been as much neglected, and our knowledge of them has 
been in a reiograde state ever since the method of distinguishing 
them by their habitudes, with the blowpipe and acids, assKetched 
out by.Cron&tedt, has b^en negleeted by the Weruian School. 

'. ""^ ■ ■<" ■ ji i . I I ■■■...■■u .11 ■ .^^ 

AGRICULTURE. 



On the comparafixe Profits of JViltshlre Merino^cross SAcep, By 
JVloKRis BiRKiiECK, «/' IVurborouj^hy iii Surny — ^^ricutiuraf 
Magazine y No, 33. 

Mb.. Birkbeck states, that he exhibited at Lord Somerville't 
j^ttle show last spring, five Wiltshire wethers, and three quarter 
lyieriqo wethers, both of \Vhich lots were taken into keeping on 
the 30th of November, I8O9, and seiit to be exhibtted the *2nd of 
March, 1810; they were all kept on hav, lu.nips, and oilfcake. 
.fhe Wiltshires weighed in November, 8 I7lb., and increased iu 
ihe 13 weeks of the experiment, 182ib, which, at 8d. per lb., 
amounts to 6l. is. 4d., and ^s. 9d. is allowed forHhe growth oi 
wool ; and the cost of iheir U^ud during the time, was 7l* 14s. 2d., 
90 that the loss was ll. 4s. Id. The Merino-cross sheep weighed 
\ii Novemb«»r, i?37lb., and gamed in th** same 13 weeks, 133lb., 
which, at 8d. per lb., amounts to 41. 8s. 4., and IL 5s. is al- 
lowed for the growth o\ wool ; and the cost oi their iood during 
the time, was 4<l. ISs. 2d., lea>ing a profit of I5b. 2d, The mfe-^ 
pence drawn from this experiment, is, that the tood which wa» 
coiisuuied by the large sheep, would i»ave produced /ottr^ww per 
ttstf n*ore in absolute weight of mntion if consumed by the small 
y,heep, besides the ditiereuce in the value of the wool, and the price 



234 Mr. Hardy on the XjrWwti of Turnips in the Island of Jersey. 

of the mutton. The Wiltshire mutton was sold in Newgate mar- 
ket, on the 5lh of March, at 6s. 8d. per stone ; fuad the Merino, 
ihe sa,me duy, at 7^. per stone. 



Observations. ^^This experiment seems to have been made with 
eqaal tdirne s and accuracy, and the inference is ^uUy w.4rrante(l 
by the premises , but it is conceived, that the growth of the Me^ 
rino-cross wool is valued too high at ll. 5$^ since that value 
would e€|ual the value of the produce of pure Mineros. 



On the Culture of Pc^rwips in the Island of Jersey ^ and their Utility 
infetdln^Cattk. B^ Chakl^s {^b IIardt, E.squire* 

The most regular crops in the island of Jersey, are stated to be * 
ebcans and parsnips, which are cttltivated by every farmer, for the 
^ jxnrpose of fattening bis hogs and cattle, and of feeding his milch 
pows, and though parsnips had for a few ^ears given way to po- - 
tatoes, yet further experieiice has bi ought the farmers back again 
to their former practice ; for though the produce of the potatoe 
is greater, and the ex pence of its cultivation less, yet it is not 
found to be really so nptritious as the parsnip. 1 his root thrives 
almost any where, bttt best in a deep stiif ioam, and is generally 
sown after barley ; the soil is either dug with, a ftpade after a 
skimming plough, or stirred with two ploughs of ditferent shapes 
following one another^ for tiie soil ft)r this pi^rpose nnust be stir, 
red from the bottom, and a ph)uoh is made for this sole purpose, 
which will go to- a depth of fttteeii inches. This operation takes 
place iir January or February. The ground tilled m this way, is 
coarsely harrowed, and Leans aie dibbled by women in rows ^ve 
feet asunder, and the parsnip seed is then st»wn broad cast, and 
the whole finely harrowed. In May the ground is carefully 
weeded, both <>y hand and vyith a small weeding fork, and the 
hand-hoe to thin the crop, like turnips, has been used with advan« 
Xage. In the beginning of September the beans are pulled fronj 
the parsnips, and about the latter end, these also begin to be dug 
up, but are only taken as wanted for the cattle, till the ground re- 
quires to be cleared for sowing wheat, which is gienerally by the mid* 
die of December. The unconsumed part of the crop is then brought 
dry under sheds, and will keep good without any care to the tn6 
of March ; but if they are to be kept longer, they are stacked in 
double rows, one over another, with their heads outwards, with 
alternate layers of earth; and this method is always adopted for 
thobe intended for seed, and for culinary purposes : they are not 
injured by frost, and will vegetate alter being frozen. They are 
given raw with advantage to hogs and horned cattle; but the^ 
Tender l^orses langnid, an4 are apt to injure their sight. Cows 



J 



ilff/or Cochrane on the Properties of Furze and tVhms. 2S5 

fi^ upon parsni{>s in the winter months, are said to produce a 
greater quantity of milk and butter, and of better flavour than 
wheii fed upon potatoes, but the leaves must not \t used, as they 
give a very disagreeable taste ; they are considered dangerous 
Food for sows before they farrow, but hogs may be fattened with 
them in about six weeks, and they aie sometimes given to sheep 
for the same purpose. It is a general opinion^ that all cattle may 
be made fit for slaughtering in less time, and with half the quan- 
tity that would be required of potatoes ; the butchers give more 
for them iu proportion to their weight, and they always contain a 
greater quantity of tallow. 



Observations. ''^^Yii^ communication respecting the culture and 
Use of the parsnip, is one of the most valuable which has appeared 
ip the magazine feu* a long time, and is highly deserving the at-^ 
tention of agriculturists in this country, where it might be culti- 
vated with nearly equal advantage, by consulting the difference of 
tlimaie; VVe strongly recommend the trial. 



On the properties of Furze and Whins^ By Major Spencer 
Cochrane, of MarsHeld Home^ North Britain^ — Agricultural 
Magazitiey No* 33* 

The writer^ bonceiving that though the utility of whins or 
furze, as a food for cattle^ has been long knpwn, yet its value as 
a medicine had not been duly appreciated^ stales,, that a relation 
of his, who has been an officei of the army, and now enjoys 
good health, at seventy five years of age, informs him, that his 
feight had been much strengthened by drinking an infusion of 
furze blossoms, dried in the sun in summer; the infusion was 
made from a cup-ful of the blossoms in a teapot, in the sam^ manner 
as tea, and the dose half a tumbler at night, which acted as a diu* 
retic and by perspiration, and when increased, promoted sleep. 
It is also stated, that the same gentleman, when on military 
Service in Ireland, in a poor village, which afforded neither 
bran nor malt for mashes, preserved all the horses of his troop 
by giving them 'furze, cut and beat on a pavement, being at 
first mixed with oats to induce the horses to eat it, at a time 
when an epidemic cold prevailed through«ut the. regiment, and 
desjtroyed many horses in other troops, aud that his was the only 
troop in good condition at the review. 



ObtetvatibtiU'^The utility of furze, both in blossom, and the 
tops of tbfi plaata, bas been ionjg^tiSed as aniedkine in the 



s . 



iSG . 'Major Cochrant m the ProptrtU$ of Futze and WMns^ 

Northern couu lies, as a sudorilic in colu- .^.u iou{e:bs ; und th^ 
inloitnation roainiutucated in il is pa| • • se* . b u>(onhtDiihe 
inference by • aiiai«jgy, that it will pruuucc bituxlar etkctt, when' 
iidmiuistered to hordes; 



ERRATA 
iN OUR La&T numszr. 

1*. i^y I. 29, omit. It should — mixumudi: 
S6, 1 5, for ten re^d fourteen ; 
6, for 12, read 8; 
9 fbr five read sevfcti; 



.. 1. > . .JMi 



-i^^fci^ ji 1 1 ■ 



M^ 



iVb. JtXKviU bef^liihed Niottmb^ 1, 1810« 



** 



RETROSPECT 



*•*:• J 



■ 



OP 



PHILOSOPHICAL, MECHANICAL, 

CHEMICAL AND AGRICULTURAL 

DISCOVERIES. 



iBS-aMi 



± 



- No, XXV.] July^ August^ September, 



mmmmesi 
[ISLO. 



CHEMISTRY and MINERALOGY. 



On the Urine ^Camels, and that of Horses ; atid on the Uric Acid in 
. the Excrenients of' Birds, By Mr, Chevreul. — Amudes de 
Chimief vol bj, 

1M[r. Brandt having announced the discovery of phoephate of 
lime in th«i urine of herbivorous animals, and that of nric acid inf 
^e urine of the camel, it became necessary to examine theM 
statements. 

The urine of the camel, even when quite fresh, contains carbo- 
nate of ammonia, for it e^ervesces with acids, and white vapours 
are produced when a substance impregnated with muriatic acid 
is brought nigh it. When distilled, it grows turbid, deposits m 
Cray, earthy sediment ; and there comes over, carbonate of am. 
nibnia, and a volatile oil, which gives it a peculiar smell, and the 
property of becoming rose-coloured when mixed with sulphuric^ 
nitric, or muriatic acids. 

The tirine remaining in the distilling vessel, was filtered and 
^fivided into two equal portions.* The first was eviaporated to 
the consistence of honey, and formed a very dirty brown ex** 
tract, totally soluble in water. Oil distilling this extract, it 
melted, and there passed over carbonate of ammonia ; pnissiate 
oTamniibnia recognised by suspending a skain of cotton impreg- , 
Bated with green sulphate of iron in. the receiver for a few mi- 
liutas, and then dipping it into water acidulated with sulphuric 
acid» which turned it blue ; citron yellow oil, composed of oil of 
I)ipp'el, prussit acid, and ammonia; brownf yellow oil; asttlphu^ 
reous very bitter charcoal remained, which yielded by elixatioD, 
• ' No. 25.— Vol. vi. 2 i 



238 



Mr. Chtvreul on tie Excrements of Birds, SfC. 
hvdroguretted sulphuret of pofash, and a large quantity of pm-- 
Ste The water employed to wash the volatile prodacts w^; 
examined by solution of silver, and no traces of munat.c acid 
^er™discovered, so that camel's urme does not contam munaf 
of ammonia, or at least a very mmute quantity. 

The arav earthy sediment above mentioned effervesced with 
aciaS was divided into two parts.- One was « kmed and 
dW not S»n effervesce wtti nitric acidl but a small quantity of 
charcoal was %arated. Tha solution was rendered turbid by 
ammonia, and was found to contain silica, magnesia; Ume, and 
sle tram of iron : it is evident that the silica must have been 
some n aces oiir otherwise have been so- 

S inth a?.d The other portiin was digested in-pure potash 
lut)le m tne/c'"- ., , j[ ^ was not rendered turbid by 
^"^runtS^f days w ve e^^^^^^^^ which showed thatthisre- 
acids, until s«'"^> f ^>' „ric acid; This,alkaline liquor super- 

?r t/dwUh aS wa7evi^^^^ ^ dryness, and afterwards 
Saturated wUh acid was V ^^^ ^^^^^^ ^„j ^^ ^ 

mixed with >«'« ^^^^^ ' p7eLt; neither was the magnesia already 
no Pho^Ph^lf ^ 'J^^^Xt fin the state of a phosphate. So that 
discovered ifl ^^\^l°'^'j^ ^{ ^ small quantity of animal matter,' 

£^;rn"f-"-^-«^»^ ^' ^^*^''"" 

and a ""«"*« P^y*';h\he"above substances had been separated by 

TJrine from-which^tne a formed a crystalline mass 

concentration was evaporated uni being poured upon tfils 

on being <=°«l*='l- ,.;f,\twn and o„ /eing distife yielded a spi. 
„ass became redd^hbro^n ana g^^. ^j ^^^^^^^, 

tit impregnated with <=^I°~t ^hi^h remained ^as treated 
from <le--P"^f "^!" to eVpel S alkohol. Dilute sulphuric 
tvith water, and 1>«^*^° ,'° .^^^benzoic acid, which became white 

^id threw 'i-;" - ^ f "^t Set being then distilled, yield- 
on being twice suWimed in ^^^ ^^^^ ^^^^^^ ^.^^ 

ed a small q»^"^f y f 'J":tLf of urea, whieh, on being separated 
acid, yielded crystallized nitrate «^ 'evaporation, redfoily pelli- 
from the liquor, yielded o«^ <=^^^^. J^^, ;, e'xamined. • The' 

cles, of ^l»^<^-''^^'""f ^ f.nhMic extrrct of urine was slightly preci- 
aqtieous solution of a k"f ohc ^^^^^ J.^^ ^^ ^^^J^ /^^ t„ ; 

pit.ted by «ol"l'«". ''f £' but the incinerated extract yielded 
ever obtained by disuHaton, Q also'prussiate andcarbo- 

muriate '>^Pf ^^^ ,S Foce^ds from L decomposition of 
nate of potash. This alkau p 

the benzoate a»d acetate. ^^^^^^ ^^^^ ^.^^^^^^^ . t„ 

The salts not ta^en up ny ^f potash, some ia«rtat« and 

the solutien cetitained mucj sulpn ^. P^^^.^^^ ^^ ^^ ^^^ 

carbonate of the satne alkali. _ii redissolublb in water, sa> 

These salts being calcined v^e^^^^^^^ - ^^.^^ ^^^^ 

that they eontaiued no earthy w""*'- 



Mr, Ctietreiil on the Excrements of Birds, ^c. ^9 

^precipitate lime-water, nor restore the colour of litmus reddened 
, by an acid, so that it does uot contain any urate ofpotafeh, as 
. stated by Brand6. • « 

Hence it appears, that neither uric acid, nor phospliaie of lime 
are fbuml in camel's urine ; but that the reddish, oily Substance 
which is the odorant and colouring • principle of the urine 6T her- 
bivorous animals has been taken for it, as this substance becomes 
red by.combiningiiot only with nitric acid, but also with IJe sul- 
4)lraric or muriatic. The supposed phosphate of limeis'orily a 
.mixture of magnesia and silic«, which retains some alkali ancl 
affioial matter. 

Horses' arine being filtered some time afterit was emitted, left 
>iarbonate4)f Jime, carbonate of magnesia, and a small quantity 0} 
«niaal matter. The stale urine yielded on distillation some car. 
bonate of ammonia, but less -than from camel's urine. Alkohol 
at 40^ took up benzoic acid, acetic ec:d, muriatic acid, potash^ 
lime, magnesia, ammonia, and probably soda ; it left untouched^ 
.sulphate of lime, with a small quantity of muriate of potash ; but 
,no traces of prhosphate of lime were found. 

When hprses' urine is (evmetittd, it does not yield carbonate of 
'lime, nor sulphate of potash, as the acetic acid that is produced 
decomposes the carbonates of- lime and magnesia, and part of tlie 
acetate of lime is also decomposed by the sulphate x>f.potashy by 
jwhich sulphate of lime is produced. 

The excrements :p(- the eagle and vulture, being digested in al- 
icalised water, let'iall, on adding muriatic acid, a crystalline pre- 
-dpitate, which wa$ evidently uric acid, as it left a bulky carbo- 
naceous residuum when distilled, and yielded prussiate of ammo- 
nia and a sublimate similar to that obtained from common uric 
acid ; it was^fhanged by 6xymuriatic acid into oxalic acid \ and 
it dissolved With effervescence in nitric acid, and became of a fine 
.red colour on evaporation, so that it really is uric acid. 



<■= 



On the oxidizement of Iron* By Mr^ Hassenfiiatz.^^««, de 

CMmict voL 67* 

Thb very extraordinary experiments of Mr. Darso, respecting 

- the oxydizement of iron, requiring an examination, they were re- 
peated with the greatest care. 

The iron filings employed were previously examined, and found 
t9 contain only an 'indeterminable quantity of carburet of iron and 
of silica, with some traces of alumine and lime. They were cal- 
cined with the greatest care, and cooted under a bell, then weigh- 
.fBd, and afterwards ground on a porphyry, and a^ain weighed. 

- {[ive grammes of iron-filings werb employed, and the porcelaia 
^apBul« weighed 29 34 gr. 



g4Q ^u-PaumfT<Ktz on ihe oxudizemiefif qfiroit. 

WfiighU Gain. lioitic 

Capfiule »nd filings before calcinsktioo, gn 34*34 >■■' " ■■ rr — • 

after 1| hour's calcination, •, 34-885 Q'54S 

■ ■ I ■ when ground, 34*945 — *r- 

; ■ - after another 2 bourns caleinatioQi 3 5' 1 0*^ 1 5 

when ground, 35*09 




after another $ hour's calcination, 36*53 044 

when ground, 35*52 r-"-r- O'Oi 



after another 4 hour's calcination, 36*3'8 0-86 
when ground^ S6.37 




after another 6 hour's calcination, 36*42 0*05 

- when ground, 36*405 -— — • Q*D15 



after another 4 hour's calcination, 36*4X)5 



m^ 



when ground, 36**39 . *r— ^ 0*014^ 

* after another 3 hour's cajcinfition, 36*39 — r- ?^*r^ 

* - " When ground, 3^*375 r— 0*0 J 5 
' after another 2 hour's calcip^^tion, 36'375 -^ — — r-— . 

* ' i ^ whefi ground, 3jS*3(> -r-r* 0*015 
" " after another four's calcinatiop, 36*36 — — r^ 

Of course 100 parts of iron, could not by this operation be 
pombined with more than 42*224 of oxygen. The oxide cont^iiir 
ed silica, ^lumine, and lime, as the iron : b,ut ijt b^d lost the carr 
bone. 

As Mr. Darso had stirred his filings while tbey were calcining^ 
Bnd al^o blown upon them with a bellows ; 3 grdinnnes of the pre- 
ceding oxide were calcined afresh seven times 9uccessively» in th^ 
strongest heat of a muffle furnace, and afterwards triturated. It 
Was $tirre<) during these ealcinatio^is with n. glass hook fi^e4 al 
the end of a poker, and the air was renewed by means of bj^Jlpw^ 
At tbe end of the fourth calcination, the oxide centred in tKo 
proportion of 45 parts of oxygen, to 100 of iron, b^yoo4 which 
proportion it could not be carjried. Guf niveau has, accQi4ing tQ 
a private communication from him, been able to combine 44 parts 
€rf oxygen with 100 of iron, which, as it is extremely difficult to 
procure iron that does not already contain some carbone and oxy- 
gen, shows that the above result is very near the truth. 

It is therefore probable that some substances got mixed with 
Parso'sQ^i^^ during its preparation, and tberefore Ibe difiR"^ 
respecting the number of oxides of iron remains as before : . a»4 
the next enquiry to be made, is the analysis of the alleged whitA 
pxide to determine whether there be^ ^s is asserted by PrPUst, 
pnly two oxides of iron, one Containing 45 of oxygen with lOO of 
iron, and the other only 30^ 

Observations, — We consider this paper as eaticsly subv^r^iyt 
of. Mr. Darso's experiments, ^nd exhibiting their inaccursMSjs in 
tne most complete manner. , * • . 



( m ) 



On the coaguldiwn of Albumen by Heat^ and Jcids^ Bjf Mr^ 

THiKAUp.-^-^im. de Chim. vol. 67. 

The coaguUtipQ of jJbunien takea place ip vacpo as well 
Its in the atmoa^here ; no gas is disengaged, and no other 
nfteradaii. takes piace bnt thai thcr albumen becomes ifisolubla 
hi water ; as thai unleu water is formed, which is not probable, 
it appears that concrete albunea differs only t'roni the liquid by 
its particles being nearer to each other, a^ thus rendered ibk 
soluble in water. 

Concrete albumen is soluble in very diiuto solution of eaustie 
potash^ and thus re-acquires all iis former properties. When tha 
aikali is saturated by an acid, the solution is scarcely rendered' 
turbid I but if an excess of acid is added, a precipitate is obtained 
similar to that formed by the acid and liquid albumen. And 
this coi^densation of albumen is also evidently shewn by its 
being thrown down in flakes when alkobol is poured into liquid 
albumen. 

« As albumen is coagulated by heat, it seems as if the action of 
water upon it was diminished in proportion to the encreasffd tern-' 
perature ; it is however necessary that the albuminous solution 
should be in a concentrated state, to undergo a sudden c«aV 
gulation, or the excess of water must be previously removed by 
the heat. 

Acids coagulate albumen, but unl/ess they are very concen** 
trated, the coagulation is produced by their combining with it, 
and thus rendering it unsoluble. This coagulum is redissolved on 
saturating the acid with ^n alkali, even with ammonia. The 
least "soluble of these combinations is that formed by nitric acid, 
on which account nitric acid will render a solution of albumen, 
upon which other acids have no effect, turbid. Almost all the > 
xnetalHc solutions are precipitated by albumen. The precipitate is 
always com)K>8ed of acid, oxide and albumen, and ii more or 
less soluble in an excess of albumen; sometimes it is very 
s^oluble in that fluid; hence it is evidently the albumen that 
bolds the small quantity of iron contained in the blood in so« 
Itttion. 



&fsaratians.-^Tht coagulation of albumen by heat has always 
b^n a great stumbling block to chemists; and a variety of dis- 
cajdant opinions have been> formed upon the subject; the expe« 
riinents lately made by Mr. Brandt upon the animal duids, by 
means of a galvanic apparatus, of which an abstract was given " 
Iti vol. V. p. 456, should kt. compared with those related in 
tb« pratent paper* 



( «*« i 



jsassx 



•mmm 



Veto preq^ss for' preparing liqijLid Acetate of Ammonia^ or Spirit pf 
Minder erus. By Mir, DztTOVcnis^^uinjiales de Chimie, vcl, 67. 

Tbs present .processes depend upon the ose of hydrxnneters, 
,¥rhicb fr^uently leaei to errors, as do alsof the use of ^reatgents, to 
indicate the saturation; ^herefotre<the doafade deconoposition 0/ 
fl^ts s^ems to oi&r a pjeferable . method. 

Acetate of lime dissolved in three times its weight of water, 
was taken, and solid cajrbonatte of ammonia was added ; carbooic 
acid vas dii-^gaged, ai^d carried with it some carbonate of am- 
monia, .y^hkh shewed that the lime took less rarbonic acid to 
saturate it tl^tn was contained in the amnu>niacal .carbonate; 
required. The .carbonate of lime was separated by ttf^ ftLtre, and 
the acetate of ammonia exhibited 6*^ hydf. The nndecomposed 
carbonate of ammonia gives a. disagreeable. odour to.tfae .acetate, 
and if it is got rid of by heat, an excess of acid occirrs, th^. 
iaturation of \9rhichy b;^ ^iquid ammonia, it is difficult to perform 
exactly. 

Oxalate ^f ammonia being too dear, the tartArtte in;solutioQ 
was added to a solution ,of acietate of lime; an excessive 
quantity of tartarite of li];ne was thrown down^.sb that it must 
1)6 washed with a quantity of water in order to separate the 
acetate^ which renders the process inconvenient; althongh it be 
exact* ~ ' 

The mixture of acetate of lime with sulphate of ammonia, of 
acetates of barytes and strontian with sulphate, carbonate and 
tartarite of ammonia, and of acetalbe of lead with sulphate, car- 
bonate and tartarite of ammonia were all tried but found to hi^ 
inconvenient, and the following was at length adopted, . 

Three ounces and a half of acetate of potash we're dissolved • 
in one ounce and a half of cold.wat«?r; two ounces of crystallised 
sulphate of ammonia were also . dissolved in four ounces of cold 
water. The two solutions were mixed, sulphate of potash was 
precipitated, and as they had become warm, the mixture was 
allowed to cool, and then filtred ; after which the sulphate was 
washed with two ounces of cold w^ter, and the liquors being 
mixed, eight ounces of saturated acetate of ammonia, shewing 
10** by dr* were obtained, of a very slight amber colour, witboul 
any disagreeable smell, and which could bekept without altering 
The excessively minute quantity of stilphate of potash that may 
remalp united with the acetate, can be of no consequenftct . 

Mr, Deyeux remarks pn this prj^cejs,, that it is U3(b1€SS to 
apply the abstract theory of chemistry to th^ coi^positiOA ^ 



On tie, Decmpcfkkim tf Suipktt* ft4i 

iHCtny me^icaiBents, and that it is frequpotly much better . to 
follow implicitly, the formula of the original proposer, unless it 
contaiii& som^ absurdity* It may be questioned whether the' 
powe^iof tj^is medicine' doe§ not arise from the^suul excess of 
alkali that it. cepta^iis., 

To-^btain a medicine always equal in strength, with as little 
fleparture as jf>©»sible from the original process^ dry carbonate of 
ammonia may :be dissolved ip eigbt ti,m^ its weight, of distilled 
water, and dwiilled vinegaXy shewing 6° hydr. may be added 
uatil.the effervescence rceases. Although this liquid;wiU not be 
exactly, ntutral, it,\iiiOuld be always in the same state of im* 
perfect saturatioii. 



t» 



Obiertations, »^The retnaricH made by Mr^ Deyeux, on the 
paper off •Mr. Destondbes, a\t iso just, that it is useless to «ay^ 
«ny thing 'further, than to allow the merited praise to bis 
simple process, as fulfilling th: intention of the original author- 
Di the most complete manner. 



assssessss^ass^^ 



A continuation of the experiments upon the Decomposition qfSuhhwr^ 
By Mr, CuRAUDAU. — Jou7.i. de Phys, to!. 67. 

.As the experiments mentioned in. the first essay on tliifr 
subject were judged to be incOaclusive, the following new ones 
were made. . • . • . . . > . . 

Instead of elixiviating the residuum of tbe <;alclned animal 
charcoal and sulphate of potash, as in the former experiments j 
it was mixed with one fifth of sulphur, and heated. At. first mucl^! 
ammoniacal gas was emitted, to whiqh. succeeded hydrogen and{ 
caiburetted hydrogen. The residuum being elixiviatcd, the ley 
was darker than before, which shewed tli^t it contained more 
carbone ; it also contained less prussic acid, but on being exposed 
to the air for some months^ the. property of forming Prussiaa 
blue was gradually increased. 

As the residuum did not yield hydrogen before 'the sulphur wa» 
added, that gas must. come from tlie sulphur: the carbone found 
in the ley must also come from the sabie addition ; and the des- 
tructioR of the prufisie radkal 19 fxplanable by the hydrogen of- 
thc sulphur combining with the azote, and forming ammonia 
which escapes. 

A solution of azotised- sulpburet of potash acidulated with 
sulphuric acid, yields with a soluti<ii of sulphate of iron at the 
maximum of oxygenisement, from one fourth to one third more 
Prussian blue than the sulpburet acidulated with sulphuric acid 
saturated with nitrous gas; whereas-the contrary should, on the 



iU Oti the DUddilky of Atkohol k Tiemom^eri hy agt^ 

tfdmfeaon hypothesis of tbd disoxyg^fiisem^t of Che liitroiiii go 

take pla(;e. 

The solutroR of azotised sulphur^ of potash yi^lds^ on being 
iitrongly aeidulated with sulphuric acid saturated with nttrooA 
ga&, ail abundant precipitate of sulphur,- ^hieh it not the casii 
^ith oiher acids. It has been thought that the Oxygen of the 
Aitrotts gas combined with the hydrogen which held th« snlphuf 
In solution, and thus tbr^w down the sulphur. But on thid 
hypothesis, why does not the oxymuriatic at id act in the sam^ 
teanner ? It is therefore probable, that the solution so for froti^ 
holding any excess of hydrogen is in fact deprived even of som<$ 
part of that which constitutes the sulphur, and that the nitrouif' 
gas really acts by hydrogenisiDg thr dishydrogenised carburet of 
auiphur, the water being decomposed in consequence of the joint 
iattractions of the dishydrogenised sulphur for hydrogen, and of 
the nitrous gas for oxygen, to which attractioas succeed ih« 
attraction of sulphur for oxygen. 



M* 



Ob$ercatiom,'^xi the last number, p. 199, the remarks of 
Vaoquelin and Berthollet, on these experiments may be founds 
as they recited them in their confutation of his first paper. 



issstA 



J^ttniym of the DatoUtt. By Mr. VAUQUELiN.^^irvnr. it Fkys. 

vol. 67, 

KLApnoTH has already given an Analysis of this stone. 

The specimen analysed was white, with a slight milky trans* 
]]farency ; it scratched commonjglass ; the fracture was glassy' 
and smooth, very like that of quartz. It was easily acted upon' 
by acids,, and changed into a transparent gelatinous mass. 

The stone was dissolved in muriatic acid, and was found tcr 
contain 37*66 jier cent, of silica, 21*67 of boracic acid, 34 of 
lime, and S.5 of water, and 1M7 were lost in the operation. 

OAie/ra/tW.— This analysis agrees very nearly with that of^ 
Klaproth, which is mentioned, vol. ii. p. 365, \Krhere a further 
account of this new stone may be* found. 

-^ -I I. ■ " ■'.' J'-^. ■' ■*»"^*«P*i*— I - u ' 

1 • On the Diminution of the dilatabiliiy ofAlkohol in Thermometers hu 
age. By Mr. Honors Fi»aug£rgues.— Jiotem. delPhy$. vol. 60. 

2t. Obteroatiom oH the obace paper. By Mr. Cotte.^— JM. 

3'. Additional odservations on the abffoe subject. By Mr* HoKOiiC 
Fl AUG SEGUES. — Jourtt. de Phyt. vol. 67* 

Hallsy and Muschenbr^eck affirmed; that the atkohol used 



On the IMatabiUiy of Alkahol m Thermomeicn ly age. 245 

fffU* making therxnojneters lost a' part of its dilatabilityy by age„ 
Hbut Nollet aod Brisson topported \li^ con^ry opinion on the 
iaith of an experience of more than thirty years. 

But on examining a spirit ' thermometer xnade in'I734yhy 
llr. NoUet, it was foand that it fell down 1^ and a qiiarter 
{below 0^ when kept in mdting ice* 

Another spirit thermometer, made in 17^3 by Mr. Romien, 
.and which is inclosed i« a glass tube, hermetically sealed, fell 
r^wn to 2^ and a quarter below O^on being also kept in melting 
ice. * 

It is intended t(^ preserve these thermometers in order to 
.examine whether the <ilkohol in them will suffer a further dlihi- 
mutioQ of its dilalability : in the mean time it is evident that 
^quicksilver i^ to be preferred )for the construction of these instru* 
iOients. 

Mr. Cotte observes in the above experiments, that at the 
(time mentioned, the 0^ of thermometers was liked by Reaumur 
»and Nollet, at the freeing point of water, which Deluc hits 
ishewn to be eight tenths of a degree above that of meltliYg ice, so 
.that the diminution is in reality very slight, and may be 'ajkChbed 
»to some other cause, especially as the latest made tLerniometer, 
had the greatest difference. That quicksilver is preferabi^^ to 
alkohol is certain^; but this arises from its more equal dilata* 
ibility. • 

In his seqond paper, Mjr. I^auj^ergucs remarks, that allowing 
the first thermometer was made, upon the original princjle Of 
^xing the 0» at the freezing point of water, as is very probable, 
of course the temperature of melting ice would have been ^ O'^'S 
instead of •^— 1***25, so that the alkohol must have lost 12 05 of 
its dilatibility, instead of l^'?i>, as stated in the former ]j^ ;er. 

This loss of dilatability, is therefore neaily similar to that of 
the second thermometer, an^ the difference may arise from their 
respective ages, and also from differences existing in the alkohol, 
«^ it may well be supposed that liquids formed of common spirit 
.of wine mixed with about one fourth part of common water, and 
^coloured with an equally uncertain dose of annatto, are not per- 
/ectly alike. 

OhsevotUkm. There is certainly no occasion to wonder at 
j^o complex a liquor as the tinged spirit used to fill thermometeiS 
being affected by age; of course the observations of Mr. Flaii- 
gergues may be added to those examples that have already 
foccarred oi slow and gradual changes in bodieSi taking iMny 
(years for their coippletion. 



TAo. S^.^TOL. VJ. 2 K 



( «*« ) 



f-r' 



N 



On tht Meam of detefminipg the Proportion ef Acid ondBase^ vi^k 
enters into the Composition qf'Sufphate andjilumine^ and in those af 
Sulphate, Nitrate, and Muriate of' Potash, By Mr. Cvraubav. 
'^Joum, de Physique^ vol, 67* 

The results obtained in the alum manufactory at Vaugirard, 
being very different from those commonly stated, occasioned aa 
examination of the subject.. Instead of ^1 parts of acid forming 
100 of alum, It required 43 or 44, and instead of 10 and a half 
of potash, 100 pans of alum required 15 and a half. It was 
at first conceived, that the surplus acid and potash entered 
into the composition of the insoluble sulphate of alumine utrhick 
was sometimes obtained, as no doubts were entertained of tb« 
exactness of the statements already given of the proportions of 
ingredients in alum, 

in pursuing this enquiry,' very regular crystals of sulphate of 
alumine were obtained, instead of the lamellar, micaceous masses 
Mtherto known, and this pure sulphate was a very excellent re, 
agent for determining the quantity of potash in vegetables, either 
|>efore or ^fter ^heir incineration. 

One hundred grammes of sulphate of potash were dissolved by 
Jjcat in 850 gr. pf a solution of sulphate of aiumine, at 34* cent, 
iherm. and ^02 gr. of very pure alurp weie obtained by cooling 
^he solution. By evaporation, the liquor yielded first 18 gr. and 
then 4 gr. more of alum. ^5 gr. of the above solution of sul- 
j>hate of alurnine yvere th^n ^dded to it, but scarcely any alum 
was separated. 

62 gr.. of potash purified by alkohol were saturated by 48 gr. 
of sulphuric acid at 66°, and the sylphate mixed with 850 gr. 
of the solution of sulphate of alumine, at 34^, and the process 
.carried on as before; but only 408 gr, of alum were obtkined, in- 
stead of 524, which shewed, that the proporti9n of potash and 
acid contained in sulphate of potash, were incorrectly stated at 
€2 per cent, of the alkali. The exactness of these experiment^ 
"were evfdent, from v^ying the quantities of the two sulphates) 
and, it was equally evident, that, knowing the. quantity of alum 
i;iyen by 100 gr. of sulphate of petash ; and, on the other hand, 
.by & giv^n quantity of potash saturated with acid, it was easy to 
^calculate an exact statement of the proportion of the ingredients 
|a the sulphate. 

From the preceding experiments, it appears, that potash ought 

gform 4-5th8 ol the weight of sulphate of potash; but as this de* 
rminatiMi was opposed by the acid not being capable of losing 
/niOjre jUiap 2-3d.s of its iveigbjt ij^ combining with the alkali^ i( tv84 



Atr. durHtiau oh the Camposttion •fSidphatey ifC. iXf 

cBbiieivedy that the potash itself lost some of its wetgttt wheit ' 
tombiaed, on account of its not being, any more than the acid^ 
ift a state of perfect dryness. It is hov7, indeed, agreed, that 
potash purified by alkohol contains water ; Berthollet estitnatet 
the moisture at 15 per C'eiit. aiid Ilardet, from hid iSxperiments^ 
finds twice as much. 

The interesting expcriraerlt of Mr. Berlholl^t, in Which potasli 
was treated with iron filings, is not sufficiently rigorous ; and the 
substances that are employed to discover the water contained iii 
potash ought not to be oxidizable, but' their action should be 
confined to the niere Separation of the water contained in the al- 
kali.' The following appears to be the b^t adapted for this pnr^ 
pose: 

^0 grainnies of potash, ^^bi(^h had be^n prepared in the la- 
boratory of Mr. VauquSlin, were mixed with l6d grammes o^ 
very pure siUca, which had been previously heated for two houri 
in a forge lire ; the mi^cture was put into a glass tube, weighing 
7^ gr. which was placed ia a 6mall cylinder of plate iroii to hin- 
der its beidg melted by the inlniediate adtioti of thd fire. It waA 
then ejttiosied to a vdry moderate heat for an hodr; i& toon as it 
was warm> a copious emission of vapour took place for five or six 
minutes, after which nothing was emitted. The tube had lost 
A gr. and a half of its Weight. The experiment wad frecjuently 
repeated with th<i same result. Hence^ it appearj^, that potasli 
purified by alkohol contains ^7*^ per ceht. of water, add, of 
course, that stilphate of pdtash contain^ d7*7l per cient. bf pot-^ 
ftsh, instead of 5% as stated by Bet'gnianf). 

It is remarkable, that Vaucjueliii's analysis df th^ different 
kinds bf alum, ^hewd, that sulphate of potash is fouhd in them^ 
in thd same prbpdrtibn as is stated dbc^'^cf ; and, it is tb be re« 
gretted, that Vauquelin Shduld have adopted ^ergmatth's statiQ^ 
ment respecting the ingredients of sulphate of potashi 

To ansilyse nitrate of potash, ioo grammes of it were dissolved 
by heat in SOO grammes of solution of sulpliate of alumine ai 
34^ by dr. STG'gr. 6f alum were obtained by cooliiig ; andl^ as eva- 
poration only produced a confused crystallisaiion, 10 gr; of suU 
j)huric acid at 66^ were added, as an excess ojf sulphuric acij is 
heceisaiy to favout tb& crystallisation of alum, wh^n the liquid 
^contains a foi*eign ad^d ; 84 gr. pi alum were imrhediately tfarbWii 
clown. Another hundred grammes of the solutibii of ftulphdtiS ftf 
aluihinCi were added to discover if any altini still remained ih ilte 
liquid, and i2 gr. were obtained, in all 462 gramnies. Which it was 
htcessary td piirify by solution 4iidl crystallisation, on aClcount of 
the a}um having been formed' in a liquid containing a foreign 
acid/ By this ineahs, <^he aluni was reduced tb 4I>^ grammes. 
*ry^ Experiment was frequently repeated. With the same rssult, 
^d^-MiH IOO gr; t)f nitrate of potash j^roducfe 453 of alum^ it 8]^ 



\ ' 



14t OUervaiwm on Spwdle Pkonoite. 

pears^ t&at the aitrate contains 49*7^ of potash and 50-24^f 
nitric acid* 

100 grammeei of dry muriate of potash, treated as in tbe 
preceding paragraph, producied 607 gr* of alum, which was re- 
duced by refining to 59t ; of course, the muriate contained 65' IJ 
of potash, and 34' 83 of acid. This experiment was also repeat- 
td several times with tbe same result. 

. It appears, therefore, that sulpbate of potash contains 4^7*71 
per cent, of potash, and* 42*29 of acid, equivalent in strength to 
00 at 66"^ hydr. 

^ To constitute 100 parts of alum, there is required 4277 of 
sulphuric acid at 66* hydr. 11*01 of potash^ and 10*5 of alu«> 
mine, as stated by Vauquelin. i> 

Very pure alum contains 19*08 per cetit of sulphate of pot* 
ash, 30*92 of sulphate of alamine^ and 50 of water of cpystallisa- 
lion. 

The crystallised sulphate of aluminemay be used to determine 
the quantity of potash contained in' any substance, and its value 
in this respect is the greater, as the product to be weighed is 
9.0S times as heavy aa the dry potash that may be contained in- 
them. . 

QbseroationM.'-^The valae of this paper is considerable, as s 
ipaetliod was long wanted to ascertain the quantity of potash exist- 
mg in vegetable juices and similar subjects* It is a pity- that 
Mr* Curaudau Lad not confined himself to the manufacture of 
alum, and the things connected With it, and had not, by endea- 
vouring to obtain objects beyond bis reach, exposed himself to tbe 
rej^ehensionft of his fellow-chemists, as has been the case with 
respect to his papers on the decomposition of sulphar, apd the 
existence, of carbone in the metalloids formed from tbe alkalies. 

«aBaBBBaHBB9MnMaiWBeBaBaasaaBBaBa>99ss^ 



Observatums on Spndle-TUonagtt^ or Ca/lonite^ and particularly on 
that found in the Neighbourhood of MofitpeNier, By Mr. Mak- 
cxi Dt SmKEs.— -/otrm. de Fhys, voL 67* 

. Tii£ pleonaste was first fonnd in the island of Ceylon, along 
tvith tourmalines, and other crystallised substances with which it 
■pa» confounded; Delametherie, who first arranged it as a p^u« 
iiar species, found it afterwards among the rocks ejected by 
Mount Vesuvius ; Lbermina found it among the same rocks, cuid 
Louis Cordier has observed it in all the vokauie roc%B of Closter- 
slajuck on the banks, of the Rhine. . 

praparnaud found pleonaste in the breccias of^the small Wal' 
fie hill of Montferrier, where it hofi been recognised in ^ tpfhv^ 
jnesenibling a breccia. Hitherto these stones have only be^ 



J 



0» Ifodala of tkroafoHfid in CUd'stonf. 9V§ 

foimd In this breccia ia shapeless and roahded fragments, wbich 
wre slightly altered, or at leabt rendered duller than usual in ito 
colour. The pleonaste is merely accidentally found in this brec- 
cia, and it is also found in the ravines at tliCr bottom of the Jiiil, 
ani^ng the substances which have been rolled down it; 

Pleonaste is also found in some quantity at Soret, on the left 
bank of the Lez, half a league from Montpeliier, on the surface 
of a sand composed of rolled quartz and shells. This sand lies fm 
beds of sandstone, which are very various in their appearance* 
and sometimes covered with shell limestone, containing chiedy 
ostrese, balani, and cardia* The beds of sandstone contain n\i- 
merous concretions in liimps of vari<3u3 ^izels, all lying in tin^ 
' same direction, and indicating a mode of formation like thai of 
common flints. The pleonaste appears to have been brdiigbt 
upon this sand by some accident by means of water. 

This stone has al^o been ^und on the vblcantc bill of ValnM* 
faargues, on the north of Montpeliier, and in a bed of basaltic 
tophus three chiliometer6.(two miles) long, at the bottom of » 
bill near Prades, on the north-east of the above city. 

From the hardness of pleonaste, it does not seem to be a vol* 
canic product, but formed in the humid way, before it was depo- 
sited in the beds wh*jre it is now found* It has not yet been 
found in the lava of the Vivarais, Auvergne, Etna, Eolia» 
Islands, Iceland, and the Isle of France, but only in the cavities of 
' certain rocks of Vesuvius, Somma, Closterslauch, and Campania. 
Kence, it appears to belong to the primitive rocks, especially 
since it is found along with tourmaline in Ceylon. Bui Brong- 
piart follows Werner's opinion, and thinks the pleonaste, as well 
as the coripdon-telesie, belongs to the secondary trap formation, 
which seems, in fact, from the above remarks, to have some 
foundation in respect to the former. An exact account of the 
repository of corindon-telesie (ruby and sapphire) is, however, 
wanting, v^hile corindon-adamanf In, (adamantine spar) is found 
in granite rocks, into which it sometimes enters as a component 
part, like felspar in common granite ; and therefore, it is pro^^ 
bable, that corindon-telesie and* addmantin, as also spinelle- 
pleonaste, belong exclusively to primitive recks, although further 
observations are wanting. 

t 

iiw— nmiiiiM mil iiiiiii i i i ' ' fi'iiii 



'On Nodules of Laxia fmni m Clinkstone, -^Joum* de Fhys. tol. 67* 

The rock Sanadoire, in Auvergne, has been described by se- 
veral naturalists, and, of late, several nodules of lava have heen 
ibupd in masses of clinkstone ; some of these nodules scarcely 
adhere to the mass in which they are found, others adhere more^ 
istrongly, but 6(U1 they are eatkely drifereAt. The sil^ffitCe o£ 



1^59 tUmahh on tit decimposiiim $fSufyiui^. 

those separated by a bammer, is rounded> bat irregular ; it il 
smooth, and covered with a light shining coat, which appears Xjti 
be a very thin pellicle of clii kstone. 

The nodules are of different Jcinds of lava ; the commoneBf va- 
riety is of porbns, stoney lava, of a gtay, or blackj^b gray ground 
colour, with needles of pyroxene, and flakes of felspar ; some are 
i>f black compact lava, which present, vi^hen broken, a multitude 
of small needles of amphibile or pyroxene, so that they might be 
taken for fragments of an am phobolic rock, (common hornblende) 
if some of them did not exhibit unequivDcail marks of the action 
of fire. 

, A large mass of blueish gfay cHhkstoffe^ fri thif iorreht of 
Prent«^arde, which has a le^s polyedric fracture than that of 
Sanadoire, contains gray lava intermixed with very small (*fystals. 

Lava is also found in the clinkstone of La Vedrine; and pro- 
bably in all the clinkst^ii|e rocks of this part of the Mon^ d'Qr. 

Chnkstone has always been considered in France as a kind of 
tava^ and known either by tbe name of greenish petrosiliceou^ 
lava, or greenish basalt in priSmS or tabled, oti account of \\M 
occurrence along with other volcanic substances. The truth of 
this opinion is now proved to a certainty, by the nodules of 
lava that it contains, which necessarily shetvs that the rock itself 
luis been in a state of fusion. 



Observations. — The nodules, which the author, ptdbably Mh 
JDelametlierie, supposes to be lava, are probably only a variety of 
basalt, which frequently accompanies clinkstone. The vesieulai' 
varieties of basalt have been taken for lava by many mineralists 
oi reputation. 



■'■■■ ■* ■ 



JUmarks on the Report made by Vauquetin and BerthoUet respecting 
the Aiiiho/s two Paper it on the Decompositum of Suipkur. Bg 
' F. R. CuRAtJDAU.-^Joiirji. de Vhys^ voL 67. 

. If the report, made by the committee had contained any neW* 
facts in opposition ta those contained in tbe original paper^ ncf 
answer would have been given to it ; but this is not the case, and 
the committee merely argue differently from the same facts, tor 
^ew that the experiments are of no value. 

The experiments which they repeated were not made in a pro-' 
per manner, for they added iron-filings to a mixture, in whic£ 
the iron could have no wfluence in respect to the effect that^as" 
desired. 

If this addition had not been made, the use of an earthen' Ves<>~ 
sel, by simplifying the •xperiroent, would have obliged thecom*^ 
mittee to examiue^why the pnissie radical obtained^ -fk>ra animrf 



Ottihe comtruftion and effecU of PneumaHc Tinder Boxes. 251 

' charcoal and salphate of potash was indestructible by acids, 
nrlieFeas the coiumon prussic ley is decomposed by the weakest 
of them. 

They allow, that the results of the first experi^ient in the sc- 
jcond paper are correctly stated, but they do not draw any infer- 
ences from th^ quantity of hydrogen that is eniuted from a mix- 
ture in which nothing but the sulphur can be supposed to yield it. 
•If they had som^ reasons for keeping silence in respect to this 
convincing experiment, they ought at least to have refuted the 
consequences that were drawn from it. 

. The second experiment, they pass over, as foreign to the ques« 
tion; but it serves to explain the phenomena in the third; re* 
tpecting which, they affirm, that oxymuriatic acid does not pre« 
cipitate .sulphur from the solution, because it convetls the sul- 
phur into sulphuric acid. But this is contrary to experience, for 
if salphuric acid, saturated with nitrous gas, is poured into the 
fiolution, in which, as they pretend, the sulphur is converted into 
sulphuric acid, it is immediately thrown down as plentifully as it 
would have been before the oxymuriatic acid was added. 

The report, therefore, does not overturn the fasts recorded, 
Hud the publicity given to it will eventually be favourable to tht 
eriginal theory. 

The memoir on the decomposition of the alkalies, mentioned ill. 
the report, is not that which was meant to be cited; the latter 
mras published more than six years before the other. 

Observations.'^^Tht reader is referred to pp. 1 91 and 198 of the 
last Nuniber for the original paper and report, to which the above - 
/observations apply, and also to a preceding paper in the pttaoKt 
Number. 



wtmeame 



On the Comtructian und Effects of Fneumatic Tinder Boxes, Eg 
Mr. Le BoviER Desmortiers— .Jotfrn. de Fhys, tot, 67. 

It is far more essential, that the syringe should not be leakj 
at the extremity than that it should not lose at the piston ; for, 
in the latter case, it will still cause the kindling of the agaric tin* 
deu A notch of a quarter of a line in breadth was made in the 
piston, and the agaric was still kindled ; three 'other notches w^re 
^enmade successively in the piston, so that it was divided as if 
»rere into four parU^, and still the same effect was produced, al- 
-though the air passed so freely, that the piston could be pushed 
^own merely by the hand. Pistons, of this kind, made of a solid! 
substance, are preferable to others made of a soft substance. If 
aaotches, indeed, are cut in leather pistons, they soon grow so large 
A^ to let the air pass too freely. ^ 



tST Of$ fhe emt»fructkm mdeffteU rfFnatauOk Tinder Bowe*, 

A single cotcb, equal only to tlie fonr separate notches, in tfcf 
mmwoakrence of tfae piston being cut, the agajri^ (^ 091 tafce 6rc^ 
(OB us>ng the syringe* 

The agajric tinder is prepared by bailing it ia water, and then 
^b-ying it ; after which it is beat, dipped in a solution of saltpetre^ 
moifi then again dried for use. If the ley is too strong, the agaric 
talbes np too mach sa)t, which retards its kindlii^ The best 
sgaric is that which is the driest, the softest^ and the least im- 
fffegnated with saltpetre ; the estcess of this last is discoverable 
hj the cool taste which it produces npoa the tonjgue, or by the 
if»arks which it causes the agarie to throw oat when it is lighted. 
The sparks thus yielded by the agaric tinder, have been consis* 
4nred by s'vo^e persons, as proofs of tlie pheTM>menon being pror 
dnced by electricity ; but they arise frona the saltpetre. Mr. Ve^ 
Delaonay, however, in pushing up the syringe, wijthoul ^ny agaric^ 
Iedt a dozen ti«ies,oh6erved sparks twice. 

if pistons eould he turned oui of aome elastic substance su£&' 
ciciitly compact to be worked in the hithe, it woujd be a great ad«> 
Tautage. It has been tried with eaout chooc previously wanned^ 
i» order to render it still more elastic than it is ; but, on tumt> 
ing this substajice, it iblded up under the chisseU so that it was 
almost torn to rags ; (however, it acted so well, that a Mroke of 
ihree inches was sufficient to kindle the agaric. After a few 
strokes, .the eaont chouc swelled so much, that it could not be 
tnoved without a considerable force ; a drop of oil .removed this 
inconvenience for the moment, but it formed, with the elastic gum^ 
m kind of ^rarnish, which soon made the piston stick still fastejr 
t» 'the tube. These last inconveniences might, perhaps, be 
4nrmded, by garnishing the epd of the piston wi(h caout chouc^ 
and covering that substance over with leather : if this succeedeid^ 
it might be applied to all kinds of pumps. 
-4a'9e9p«et to the cause of the agaric being kindled, it seeme 
€3«ident, that electricity is not the cause thereof, for the syrin^ 
is noft insulated ; ^Uie friction is that of an oily body against me^ 
€al; ^e atmospheric air is not in an electric state so near the 
tiyface4>f the earth, and, i^ it were, only an infinitely small quan«- 
lity of electric fluid could be contained in tlie cubic inch, ot 
iesft, of air which the syringe holds; nor is it easy to kindle 
Agaric by the electric spark. A piece of it was sprinkled over 
urith resin, and a large jar was discharged upon it ; the resin 
iook fire, bi-t not the agaric. It may, indeed, be said, that the 
'olectric spark decomposes the air, and sets .fire to the oxygen, hf 
.which means, the tinder is then kindled, but the decomposition of 
atmospheric air requires a stronger electric power than can be 
supposed to come into action in the syringe. 

As metallic syringes do not allow what passes in their internal 
part to bii stm, three glass syringes w«;re procured^ by /neaotxif 






On the consfrueiitm mdefedi ^Fneumatk Tuider Boxes. ^S% 

Hr. Lati!i;^t, the inventor of glass fltttes. The first, 8 in. lonj 
And 8 lines in diameter, would not set fire to agaric tinder ; the 
second, 9 in. long dnd 6 lines 3-4th8 in diameter, succeeded per- 
fectly, but met with an accident ; the third, 8 in. long and 7 Hneft 
in diameter, was equally proper for the purpose. 

When the syringe was worked, so as to kindle the agaric, A 
vivid Bash was seen, which filled: the whole tube, and was the 
more vivid as the compression was made ' the more quickly. If 
the compression was too slight to kindle the agaric, a slight y^ 
|K)ur only was observable at the upper part of the tube ; this VaiF 
pour I'olled in clouds upon the piston. When it had disappeared, 
it re^appeared again, on drawing out the piston, as long as anjr 
air was in the' tube. This phenomenon could be repeated severajL 
limes successively merely by working the piston with the hand* 
The vapour is so slight, and diaphanotis, that it cannot be s^n ik 
a strong light, but requires a kind of half day-light. 

This vapour seems to he caloric, rendered visible by'the eot^ 
dei^sation of its molecules by the air, in the same manner as air 
bec/omes visible vfhet it passes through liquids ; at least, this ex- 
planation receives some confirmation from the following circum* 
stances. 

Whoa hydrogen, carbonic acid gas, or azote were substituted 
for air, the vapour appeared, but the agaric was not kindled ; 
as the aypte contained a little nitrous gas, the vapour was denser 
than with the others. Oxygen, slightly compressed, produced a 
very rare and fugitive vapour ; but when briskly condensed, so aft 
to kindle the agaric, the tioder, which usually takes fire only at 
one place, was almost entirely burned, although a brass syringe 
^as used, which let air escape so fast^ that the agaric would not 
kindle in commoa. 

The vapour does not proceed from any grease adhering to the 
sides and expanded by heat ; for, 1st, It may be observed, oil -the 
first stroke oF the piston, before the tube becomes greasy ; 2d, It^ 
appears only between the piston and the end of the syringe ; 3d^ 
There is no vapour observable wh^n the piston is leaky, howeyejr 
rapid may be the friction; 4th, The vapour is not always mor^ 
abundant when the piston is 'worked the whole length of the tube, 
tban when the stroke is confined to the upper part'of the syringe j 
5th, When the air is entirely decomposed, no more vapoiir is pro*- 
daced, -until fresh air is adtaittcd- 

The colbur of a bit of muslin, tinged with litmus, which wai 
|ylaced in the syringe instea'd of the agaric, and fastened to the 
bottom by a bit of green wax, was not altered by twenty strokes 
of the piston; another bit being put in, and the edges left loose 
in Che cavity of the syringe, it was not altered in its colour, 
atlthough the edges were burned; lastly, a bit of wet mudin was 

•No.fiS; — rbt. vr. 2 l 



554 Od making Sirup ^ if c, from Grapet. 

not changed in the least, 80 that no acid matter is produced in 
this operation. 

Sometimes, it happens, that the agaric becomes black, but 
does not kindle, and, in this case, a strpng smelling thick vapour 
is thrown out, on working the piston ajfresh, the same as though 
.the agaric bad been kindled, lliis vapour is entirely differepi 
from the other, which appears before the agaiic is affected. 

As- the air, as well as the 6ther gases, seem to be decomposed 
by a rapid compression, it is probable, that the luminous me- 
tedrt seen in storms are not always produced by electricity ; and, 
in fact, Saussare's sftmospheric electrometer has, in several ia- 
stances, given no signs of electricity daring their appearance. In 
particular* a violent high wind occurred in the beginning of 
1803, aad lasted for two hours; it threw down about sixty 
large trees, belonging to the author ; atrcaks of light were ob- 
served twice during this storm, and yet the balls of an electro* 
meter remained the whole time in contact. 



> OUervations. — Syringes, for the purpose here mentioned, have 
been sold for some time in the shops of London. The theory 
generally followed, supposes the agaric to be kindled by the cali^ 
he disengaged in consequence of the sudden compression, the same 
as when iron is ignited by briskly hammering of it. It has been 
observed, some time ago, that a faint light was observable on dis- 
charging a wind*gun in the dark. Both these have some con<- 
nection with the author's hypothesis, but the subject is still too 
dark to be satisfactorily explained beyond all-contradiction. 



BBaBBeBBSaVBHMBBHai 



'On making Sirup^ hrimn or tohite Sugar from Grape$j^^By Mrm 

FocQUE.— JoKHi. de l^hyu vol. 67. 

Miu PARMEKtiER has pubUshcd a method of making sirup 
and marmalade from grapes, but the acid of the grape is left in 
them, so that ibey require the addition of cane sugar, when 
they are used for food, and the birup cannot be kept for any 
time without the addition of brandy. 

On the other hand, the sirup that is prepared from jQice of 
grapes properly saturated, and concentrated to 30"^ Baume's 
hydr. keeps for any length of time, and in about two months 
three quarters of it is crystallised in spherical crystals, which 
are the size ot millet seed, if the vessel has not been moved, 
otherwise they are smaller. 

If the sirup is evaporated on a naked fire, it acquires a reddish 
brown colour, which spoils it for certain purposes ; if a vapour 
bath is used, the sirup is' iinch.yelIow« and yields 75 percent, 
of cryiX&\% of the saiiM colour^ which xnay be refiaed to a whitt 



On making Sirupj t^c.from Orapm. 355 

jiolenr. The addition of brandy, or powder of sugar, to hasten 
the production of these crystals, had no effect. The \nfhite sugar 
made frpm grapes has not the sandy hardness of cane sugar, it is 
pulverulent and soft to the touch, and its taste is also less sweet 
than that of the sirup and crystals used together. 

It is very easy to constroct-a vapour bath by making a bank . 
«f rubbish about three feet high, kept in by hurdles supported by.' 
.stakes; the top of this rubbish should be covered wrth powdered 
charcoal, upon which a tinned copper, or plate tin pan 8- or 10 
feet long, 3 feet 8 inches wide, and 6 inches deep, must be set, 
the sides being supported by four planks; a flat eteam pipe 1S| 
inches wide fronn an adjacent boiler is to be introduced into t,he 
pan by one of its ends, and after running round it, to be carried 
•ut agaia with a sufficient inclination to let the condensed water - 
nin again into ^he hoiler, to which a common still head is to b« 
adapted. For small families it is sufficient to place a shallow 
yan 3 feet wide upon a comnK)n boiler, at a distance Just sufTi* 
cient to let the steam escape under it. 

To make about 100 or 125lb. of sirup, 400lb. of juice of 
grapes must be procured, 30 or 40 quarts of which are -to be 
heated in two parcels, until the hand cannoV be kept in it, and 
then poured into the remainder, after which is to be added 40' . 
quarts of powdered chalk, or wood ashes, previously sifted, and 
washed three times with boiling water. The wood ashes are to 
be preferred, as they do not give a bad taste to the sirup, and 
as chalk contains particles of clay that fall down very slowly, 
it is requisite to filtrate the sirup through a flannel when that 
earth is used. The mixture is to be stirred, and then left to 
settle for a couple of hours. A spoonful of the clear liquid is 
then poured into a cup of milk, which is made to boil ; if the 
fiiilk is tunvR), two or three quarts more chalk are to be added, 
and after some time the ayrup is again tried with milk. When 
the sirup by these additions of chalk will no longer turn milk- 
ofk being boiled therewith, it is ready to be evaporated. 

The trial of the juice with niiik is better than to use litmus 
paper, for when the paper is not altered in colour, there may 
•till be left su^cien-t acid in the liquor to curdle milk. The 
saturated juice after having been left till the next day to settle, is 
to be drawn oflp^ and the sediment drained upon a fine cloth ; after 
mrbich a pail of hot water should be poured in three separate 
parcels upon the sediment, in order to separate all the sugar 
at contains. 

If the colour of the sirup is not esteemed of any conseqtience, 
i^ may be evaporated in a common boiler, observing to skim 
it .vr-ell, until a drop let fall upon a coW pUte, grows bollit leuily 
0olid on cooling not to run upim the plate when the lattei is m- 
cljned ; or a hydrometer may be used. The sirup mus i theu be 
Boured into pots or casJis^ and covered iip^ 



%5S On Making Sirup f Sfcfrpm Graf€$^ 

When the colour of the sirup is of coinseqiience, tbe pressed 
juice must not tie received in vessels that have been used for 
fnaking wine, as the remains of it* would colour the juice, which 
must also be evaporated by means of steam. 

Sirup evaporated to 30 or 3S^ of tbe hydrometer, Bcquire§ in 
a month's time such consistency, that the vessel may be turned 
bottom upwards, without the sirup falling out: some sinip 
evaporated not quite so far, acquired this consistence in 15 oc 
20 day8.« 

The juice of th« white grapes, called at Paris, melier, yields 
22 per cent, of dry saccharine matter, the red grapes IS, and 
the chasselas only 16. In Spain the grapes being richer, yielded 
i$ per cent, of sugar. 

Four hundred lbs. of saturated juice of the grapes usually 
crown about Paris, yielded from 100 to 125lbs. of sirup at 30? 
hydr. in which spherical crystals were afterwards formed ; these 
crystals when drained on a cloth weighed 751b. but on being 
Strongly pressed, their weight was reduced to 60lb. On sub* 

Sitting the crystals to the usual method of refining, they wera 
rther reduced to 40lb. of good clayed (Lisbon) sugar, from 
vhich a loaf weighing l61b. of white sugar was aftexwaidi 
obtained. 

Observations, '^We have several times had occasion to remarfc 
the great efforts made in France to supercede the colonial articles 
t)y those of home produce ; and the present exhibits the intended 
substitute for our West India sugars. The price uf grapes in 
this country renders the process of no use here, but in some of 
our southern colonies, the superior richness of grape iuica 
above that of the sugar cane may eventually render it more 
advantageous to cultivate the vine than canes. The juice of tha 
cane yields on an average about one eighth of its weight ol ^ 
raw sugar; 

The paper by Mr. Parmentier, mentioned above, was abstracted 
l^y us, in our last number, p. 209. 

. The quantity of chalk ordered by Mr. Foeque to be put into 
the juice appears to be very great. lu India about three spoon* 
fuls of lime are added to fourteen gallons of cane juice. In 
i^merica a spoonful of lime is considered sufficient for fifteen 
gallons of sugar-maple juice. According to Mr. Dubuc, apple 
juice requires about one drachm (gros) of chalk, and the juice 
of pears about two drachms per quart. Some error must there*, 
fore exist in this part of the original, especially as he orders the 
"wood^ashes to be elixiviated before they are used, which, taking 
away their alkali^ mu^t render them less useful, and indeed nearly 
useless. 



Examination of Aloe Socotrina and Hepatka, 257 

Pkrmentier orders half an ounce 6f washed woed^ashes, 
dialky or whiting to be added to 25 quarts of the juic^ of 
grapes in tlie south of France, and twice that weight of Jkaiine 
substances to be used in the north, where they do notri -ri per- 
fectly, £0 that it should seem as if 4- oz. of chalk would be tiittfi- 
cteiit, and then a much less quantity of water will be required for 
IJQe purpese of Washing out the saccharine matter from the re- 
^duum* 



Compar4Uioe ExmruKation of jfhe Soeotrina and hepatica* By Mr^ 
TROMMSSiORFF. — Ann. dc Chim. vol. 6S. 

Th«ii£ are four kinds of aloes ; aloe lucida, which is very 
rare ; aloe caballing, which is very inferior and variable in its 
qualities ; aloe Socotrina ; and aloe hepatica : the two latter onlj 
are worth examinijng. 

Four ounces of aloe Socotrina boiled in three lbs. of distilled 
water formed a deep yellow transparent solution, but on cooling 
a yellow powder separated^ and when quite coid^ a yellowish 
brown transparent mass was left, on the liquid part being poured 
ofT. This mass weighed on being dried, one ounce ; it was very 
brittle, bitter, fusible by a slight heat, and insoluble in water, 
hut very soluble in alkohol, or liquid potash* It also burned with 
a vivid flame, whence it was evidently resin that had been taken 
up by the other substances while hot, but separated from thera 
ly cooling. 

The watery solution was deep gold colour, perfectly transpa. 
rent, h^c«ming brpwa by contact of the air, but nut growing 
turbid. It reddened litmus paper ; the alkalies, and alkaline 
carbonates destroyed this property, but. produced no other change. 
Muria.te of iroo ad maximum changed it black ; nitrate of silver 
or lead rendered it slightly turbid, but nitric acid restored th# 
transparency. Sulphuric, nitric and muriatic acids precipitated a 
little yellow resin from it, not e^^ceeding however two per cent, 
gelatine does not produce any. change in it. On being evaporated 
in a water .bath^ it l^t a bitter ipass resembling aloes. The 
powder of uiis mass was soluble in alkohol either hot or cold^ 
but not in ether, which it did not even colour in the least ; it 
was therefore the sappnaceoujs principfe, called by Hermbstaedt, 
seifenstofT, or pfianzenseife, found also in saffron, rhubarb, and^ 
several other vegetables. 

Four ounces of aloe Soootrina were almost cnvnpletely soluble 
in l6 02. of alkohol, a« only 12 gr. of woody fibre were left on, 
ibe filtre^ The solution was deep yellowish red. It was mixed 
with its weight of water, and the alkohol distilled off; the remain* 
^& ^^W4 ^^. i^ot U^bicV but oo beiog evapors^d to dryness mid 



25 i Description of an Htfgrometer/or Gasei. 

redissolved in boiling water, it let fall an ounce of resin on i^ool* 
ing, which corroborated the former txperiment with water. 

Sixteen ounces of aloe hepatica dissolved in water, left on cool- 
ing the solution three ounces of resin* The solution was equalljr 
acid as the former, it was rendered black by muriate of iron ad 
maximum, and made slightly turbid by nitrate of silver or of 
lead. By exlccation it left a mass soluble in water either hot or 
cold, without depositing any resin ; the dry mass vfsa also soluble 
in alkohol but noi in ether. 

The three ounces of resin separated from the solution in water 
left, on being treated with alkobol, two ounces of residuum, which* 
was divided into three parts. One part was distilled, and it 
yielded a fetid oil, ammoniacal liquid, and a bulky charcoal. 
Acetic acid had no action on the second, but the thirrf wai 
totally soluble in boiling caustie potash ; the solution, was not 
rendered turbid by water, while acids separated a spongy brown 
mass rather elastic, which yielded an ammoniacal liquor on being 
distilled ; hence this residuum was probably coagulated vegetable 
albumen. The alkoholic solution left on evaporation a resinous 
mass« insoluble in cold' or hot water, soluble in alkohol, ether, or 
caustic potash, easily fusible, and very inflammable. 

Four ounces of aloe hepatica left four and an half drachms of 
albumen on being treated with alkohoL The sohition itself waf 
evaporated to dryness ; the residuum was totally soluble in water, 
but two drachms and an half of resiD fell down when the water 
cooled* 

Aloe Socotrina may therefore be .distinguished from the hepar 
tica by the former being totally soluble iii alkoloY. 

It also appears from the above experinients, that aloe Socotrina 
contains 75 per cent, of the bitter saponaceous principle, S5 of 
resin, and some traces of gallic acid ; but aloe hepatica contains 
81*^5 of soap, 6*25 of resin, 12*5 of albumen, and some traces 
of gallic acid. 

. The saponaceous principle and the resin appear to be of the 
same nature in both kinds of aloe. 



ObsercaHon$»'^The examination of aloes has lately occupied 
the attention of the most experienced chemists on the continent, 
fts may bo seen by the succeeding papers. Messrs. Bouillou- 
Lagrange, and Yogel take part with the present author against 
Braconnot. ' - 



v^ammamafmmmmmmmammmmmmBmmBOBm 



Description of an Hygrometer for Gaset^ and oftk$ Manntv tfvsing 
it. By itfr.'G VYTON MoB,YEAV.p^^fin. de Chan. wL 6i« 

This is nothing but a sjpmU phial of flint glasS| to which « 



Contpttrative Examnation of MocSfGamb9gt^ S^c, %5Sl 

$topper oF the same is fitted ; the^ whole is then fixed in aa 
apparatus made of ii*on, by means of which it may be passed, 
completely closed, through the quicksilver in a mercurial pneu- 
matic trough, opened at pleasure, and after the enclosed sub- 
stance has remained exposed to the action of the gas for any 
desired time, it may be stopped again and withdrawn. 

When the hygrometric state of a gas is to be examined, the 
phial is detiaLched from the iron collar in which it is screwed, and 
'Weighed; it is then filled with muriate of lime previously melted 
and powdered, and again weighed. It is then introduced into 
l3iegas and left for some hours, after which it is withdrawn and 
Weighed. In some cases, fresh muriate should be added, until it 
no longer acquires any increase of weiglit. 

This instrument must not be confounded with Berthollet's ma- 
nometer^ described by him: in the Memoires d'Arcueil/ 



•^^•m^mw 



Comparative Examination of AloeSf Gamboge, Eiiphorbium, Myrrh, 
Frankincense^ and Gwn Ammoniac. By Mr, Henkt Bracok- 
NOT. — Annales de Chimie^ voL 68. 

The best aloes is brought in bladders from the island of Soco- 
tra, at the entrance of the Red Sea, and is obtained by cutting ' 
the leaves of aloe perfoliata Socotrina transversely, collecting the 
sap that issues from ihem, and drying it in the sun. 

The Socoirine aloe' that was examined was yellowish red,^ 
semi-transparent, and, when broke, there appeared yellow spots 
oii a red.groun(i ; it yielded a fine yellow powder, was very bitter, 
and bad a smell which some persons did not find to be disagree- 
able. It did not become electric by rubbing. A heat of -f 80^ 
Rjeaum. softened it, so that it was'moredifHcuIt to powder ia sum* 
tner than in winter. It melted, puffed up, and took fire on being 
pr«seoted to the flame of a candle. 

80 grammes {about 3 oz.) of aloes being distilled, yielded 8 gr, 
•f water impregnated with an essential oil to which the alces 
owed its smell ; 8*7 gr. of almost colourless water, in which 1 gr. 
of acetic acid, but no ammonia, was discovered on adding quick- 
Itioe ; 5 gr. of heavy red oil soluble in alkohol; a large quantity 
«f oily hydrogen and carbonic acid gas ; there remained *iO gr. of 
Jbardy very balky and spongy charcoal, whicb retained much hy- 
dlrogeii, and did not lose its black colour, brilliancy, nor gi eat 
liardness by an obstinate incineration ; the 7'5 gr. that then re- 
mained did not contain any potash. It was treated with mu- 
riatic acid, from whence ammonia threw down oxide of iron, and ^ 
fiome little phosphate of lime, and carbonate of potash threw 
dowi^^ a few decigrammes of carbonate of lime. By heating nitric 



i6o Comparative EsraminaHoh of jf toes, Gamiogef 4^* 

acid on this charcoal, a small quantity of tanning matter was oth- 
tained. 

Pulverised aloes, ground with cold water, forms a solution that 
lathers on being agitated. 148 gr. of water at -f 32^ Reaum* 
were required to dissolve 4 gr. of aloes, and 6*1 gr. of woody 
fibres was left ; the liquor let fall some part of the dissolved mat* 
ter on cooling. A sirup-like solution is obtainable by employing 
heat, which is spontaneously prtcipitated by cooling, and can even 
be crystallised by evaporation. This watery solution very sensi« 
bly reddens tincture of litmus ; its fine gold colour is deepened by 
the alkalies and lime-water, without any precipitation ; sulphaut 
of iron renders it brown, and throws a brown precipitate ; decoc- 
tion of galUnuts throws down a yellowish flak} precipitate, and 
the supernatant liquor becomes much less bitter and less co- 
loured ; subacetate of lead also precipitates it, aiid the liquor be- 
comes almost colourless. Nitr ate of copper or of lead, and mu* 
riate of tin, produce slight precipitates, which do noi appear to 
be chemical combinations, for muriate of soda, and other neutral 
salts^, produce the same alterations, so that the precipitatioM 
seem to be caused enly by the salt weakening the action of the 
fluid. 

A quart of the solution of aloes, kept for two months and a 
half, in a well-stopped bottle, quite, full, was not altered in its co^ 
lour; another parcel, in a close vessel, only half full, was turned 
very deep red, and was rendered colourless by oxy muriatic acid, 
which threw down a flakey precipitate ; a thiid parcel, in a clost 
vessel, only one-fourth filled, had formed a quantity of mucous 
matter. Both the two last parcels had acquired a sort pf visco- 
sity, and the dec6ction of gall-nuts produced a more abundant 
precipitate in them, than in a fresh solution of aloes> 

Spirit of wine at 38° hydro, speedily and totally tlissolved aloes; 
a few fibres only being left. The filtrated solution was red, aad 
so deep as to be scarcely transparent ; water threw down a pale 
yellow sediment, which turned brown on being dried. The alko- 
faolic solution being evaporated, the least movement, or blowing 
upon the surface, produces a kind of crystallization, which disap* 
pears, but is iramediatly re-produced. 

Olive oil, heated on aloes, had no action upon it ; neither had 
oil of turpentine, although the oil acquired a pale amber colour. 

Solutions of the alkalies dissolve aloes very easily, and mask its 
bitterness ; acids throw down from these solttlions precipitate* 
which grow dark on being dried. 

Volatile alkali forms a de^p red solution of aloes, which, on 
being evaporated, formed acicular crystals, in a resin-like* ntass ; 
lime and water disengaged ammonia from this substance. 

Weak acids have but a slight effect upon aloes. XQ gr. of aloe» 
were treated with 80 gr. of nitric acid at 36* bydr. formed a deej^ 



Coiiiparailve 'Examination ofAtoes^ Gamloge, <$*c; '^ i4i 

V^llow solution, which deposited a yellow ftak'ey substlknce, the : 
liquor was then evaporated to the consistence of honeys diluted * 
tvith water and filtered, about 2*5^ gf. t>f a y^Uo^ substance \ras 
left, which was extremely bitter; but had ail agreeable slrbniatic 
ddour. It melted like hitre, yielded an aromsitic vapour rather • 
bitter; and Idfi miicb charcoal. It afTorded^ by a gentle heat, the 
usual vegetable products, and at last detonated with a purple 
flame, leaving a very bulky charcoal, being one third of the 8ub^ 
stance distilled. It requires 0*023 gr. of water to dissolve 0*2 
gr. of this substance at -f 10^ Reaum^ The solution had the 
colour of £lrterial blbod, it did not crystallize, reddened tincture of 
litmus, and effervesced with the alkaline carboUates. 13 gr. of 
alkohol at 33° hydr.; dissdlved only 0*5 gr. bf the yellow matter, 
and formed a deep red solution. Heated ndineral acids dissolve 
the yellow matter, but it sooii separates front thera. Potash 
forms with it a deep red salt, which detonates like gunpowder^* 
ieiiher by heat» or by cOritadt with live charcoal, leaving slight 
traces of charcbal, ahd a strong smell of Prussic acid; The nttrid - 
acid frdni whi&nce the aloetic acid had been Separated, being satu^ 
rated with potash, depc^sited a ^mall quantity of the red detonat* 
ing salt ; nitrate of lime then threw down 3'5 gr; of oxalate of 
lime ; the supernatant liquor treated with nitrate of lead and suU 
phuric acid, yielded about one gramme of malic acid, partly dry; 

Aloes is not a resin, but a peculiar principle that may be Call* 
•d re^iho-amer (or resino-bitter), which is very abundant among 
*|)lants ; it has been taken for a resin, or for oxygenised extracti^ 
matter. A auquelin has described it in his examination ofquiD- 
qiiina ; it is deposited frbm the decoctions of wormwood, centaq. 
tea, calcitrapa and bbnedicta succory, dandelion, fumitory, and 
bther plants, w^hich kre esteemed febrifuges. Indeed, the febn« 
iuge quality of quinqtiina seems to arise from a combination of * 
resino-bitter witii tanum, or some analogous substance. 

It is singular that aloes ceases to purge when mixed with pow- 
Jder of gallnuts. 

Gamboge is generally supposed to be extracted by incision from 
the bark of cambogia gutta; it is brought *from Siam, China, 
^nd Ceylon^ iu cylindHcal lumpt!, and has only been known 'since 
the beginning of ibe \6ih century. It swells and takes fire at the 
flame Of a candle, it exhales when heated a peculiar smell, a|id 
^rows soft, but is decomposed sooner than it is melted. 60 
grammes being distilled, yielded a brown water 'containing enipy. 
reumatic acetic acid, a little light oil, and much heavy thick 
brb>^n oil t 8 gn of light charcoal were left, which produced at 
last 0*5 gr. of ashes, from whence 002 gr. of poiash partly 
combined with sulphuric acid' were obtained, also 0*04 gr. of 
phosphate of limej 06 gr. of carbonate of lime, aud 3 of quart* 
zose sand holding a little charcoal and some oxide of iroB* Tbo 

Ko, 25.—VOL. VI. 2 ¥ 



tQ2 Compta-atke Examinaiion <f AloUy Gamboge^ 6fC. 

liquid prodact9,did not 4eem to contain any ammonia on bein|p 
titled with iimd and the alkalies. 

20 gr. of gamboge treated with hot alkohol» lett on the iiltre ar 
grayish mass difficult to dry, and when dry it was brittIe,>aBd weigh- 
ed 4igr. lis taste was mawkishyitlet'ton being dissolved in water^ 
only 0*1 gr. of impurities; the solution reddeiitd litmus, and left 
on evaporation, a transparent friable mass like plum-gum. The 
alkoholic solution of gamboge was red^ and left on evaporation,: 
tS gr. of transparent red resin, tasteless, electric by friction,^ 
which exhaled a peculiar scent on- being reduced to a brilliant 
yellow powder. Water added to- the solution, produces only an- 
iiniform yellowish milky liquid; 

ijolution of potash rapidly dissolves gamboge, and forms a> 
deep red, oiUlike liquid, which by evaporation, crystallises like 
the solutions of aloes. The potash is neutralised, and the liquid- 
yields a friable mass on drying. It tastes like rank grease ^ith- 
a slight acrimony, and dissolves in water without rendering it 
turbid; acids coagulate this solution into a firm yellow mass. 
Limewater throws down* an orange precipitate, as do also the 
earthy salts, and those of the white metals. Sulphate oi iron 
is precipitated brown, and nitrate of cepper green. 

10 gr. of gamboge treated with 80 of strong nitric acid, until 
the matter ivas dissolved and reduced to a syrup, the liquid 
yielded, on cooling, a mass of crystals enveloped in a viscous 
substance, which, on being washed with water and dried, weighed 
0*3 grs. The liquor tiiat distilled over, being saturated witb 
ebalk ai|d distilled again, yielded an acidulous liquor, extremely 
penetrating, and biiter ; it was changed yellow by alkalies, and 
'threw down from sulphate of iron a precipitate entirely soluble 
in acids; hence it did not contain any prussic acid; tha 
substance left by the nitric soution was ydlowisb, bitter, 
partly soluble , in boiling water ; this solution grew turbid 
on cooling, and part of the substance could then be sepa* 
rated by filtering. It was of a reddish yellow, it lathered, red- 
: dened tincture of litmus, became deeper coloured on adding an 
alkali, and very slowly precipitated sulphate of iron. It did not 
- melt so easily as gamboge, up(m a live coal, it exhaled an aro-^ 
matic odour, aiidjeft much charcoal. It formed transparent red 
solutions with potash or alkohol. It was soluble, without alte->- 
' ration, in nitric acid, and water produced a white coagulum with 
this solution. 0*4 gr. more of the yellow resin ^were separated 
' from the supernatant nitric acid and water used for washing the 
\ iirst parcel, as also 1 gr. of acidulous oxalate of potash, and 3 gr. 
of bicter matter coo taming iualic acid. 

Oxymuriatic acid gas was passed through gamboge suspended 
in water, more water was then added and the liquor Altered, and 
the sediment washed with boiling water until it no longer red- 
dened tiaclur^ of lituiua. A pale yellow tasteless powder was. 



<jpmparaHx>e Erammation if Aloe*^ Oamboge, 4*c; 9$^ 

ieftf %Thich cFjackled between thi* teeth, it was not soluble in boil* 
,ing water, nor did it melt easily, nor exhale any t^mell Hntil U 
took fire, an^ then it emUled a strong smell ol' muriatic ac^k 
Weak acids had no etiect upon it, bat strong ones produced charr 
fCoal and muriatic acid* It formed with pat^jsh a substance- of ait 
agreeable soapy smell, in the solution of which, nitrate (Jtf silver 
forms a precipitate partly soluble iu nitric[ actd. 6 gu of thif 
yellow substance yielded Qn distillation into water, a liquid wliicii 
fcparated 5*4 gr. of muriate of silver from the nitrate of thaf 
metal, and 2*1 gr. of ebarcoal remained ; hence it contain^ ^2:$ 
per cent. ^ dry muriatic acid, 3^ of charcpal, an^ ^ of ojcygeoi 
liydrogen, and carbone. 

- Muriatic acid heated with thfe resin of gamboge did not prb* 
.tiuce a similar substance, hence it is probable that, the resin i9 dif^ 
liydrogenised by the oxymuriatic acid gas. It is also probab^ 
-Uiat when vegetable substances are discoloured by that gas, i% 
.enters into combination. 

Gamboge is a real gum-resin; it has beeii used as an aJHir 
Arthritic, whence its [French] name of gomme gutte ; at present 
it is only used as a drastic purge. 

' Euphorbium runs naturally from several plants of that geQia$| 
the common was supposed to come fi om the euph, officinalis, bil( 
in garbling a large quantity, some branches wece found whidft 
evidently belonged to the euph. Canariensis* Tbat used was in 
branched te^rs^* spongy^ friable, pale yellow^ scmitransparent Hkt 
bees wax, aiid so' acrid, that on putting a hit on the tongue, the 
inouth was in^mer^iately inflamed, an^ a reaching brought 0||. 
it melts easily, and loses l.-20th of its weight; 4 gr. treated with 
IQO gr. of. water left 3 gr. of insoluble matter ; the ^Iterod 9oh»- 
tion was amber coldur^ and bitter, with a slight acrimony. It 
reddened tine tuTve of litmus, oxalate of potash produced in it n 
precipitate of oxalate of lime ; the white precipitate from nitrate 
of 4ead was soluble in distilled vinegar, as also the yellQw preeijH- 
iate from lime water. 

20' gr. of euphorbittni treeted with 90 gr. of alkohol at 
M^ left 6*4 gr* undissolved. The solution grew turbid in two 
days time> and deposited a gelatinous^ white, granubr matteitt 
which weighed 4*7 gr» but on befug dried and melted, was r0» 
dueed to 3*4 gr. It was ' semitrausparent, might be cut, was 
easily softened by handling, and was entirely vpla^sed upon a red« 
hot iron, exhaliiig the sm^l of bees*wax. This wax still retainei 
some acrimony, but made a- very gopd taper. The residuum that 
did not dissolve in the alkoh(!»l, was boiled with watej-, some 
hranehes on w|iich the eupborbiuni was moulded were left, 
weiring 2^ gr. the watery solution being evaporated, it foriued 
a varnish on the vessel, and left 4' 1 gr. of brittle micaceous 
Bcalee of maldte of lime, 'i his malate wiss mistaken by some 
former cbemisU for gum^ and confounded by Laudet' with the ex- 



I 

ttfi &omp(traiive Examinafion ef Jl&es, Gamhegc^ ^e« 

tractnr* matter. The cle^r alkohoUc 8olution« being evaporat^^i 
left 8*3 gr. which left, on being treated with cold alkohol, 0*4 gr^ 
of wax; the fresh alkobolic solution left on evaporation a resin^ 
from which w^ter extracted 0*4 gr. of malate of pot^isb. The resin 
16 transparent, reddish, f^xccsaively acrid, apd electric by friction \ 
alkalies do not act upon it, for nitric acid did pot repder turbid 
eaustic pptash which had been beat«d upon the resin, but aftef 
some time, a few reddish flakes were separate^. It is soluble '\x\ 
jcold sulphuric acid ; nitric acid softens it, and, t>y heat, a soIu« 
tion was obtained which yielded by evaporation, much yellowish 
resiti-like matter, also a soluble resinor bitter substance aud foq[if 
traces of oxalic acid. 

- Euphorb'iunq, therefore, contains 5 .per cent, of watpr, 1$ ®f 
^ax, 13*5 of woody substance, 20*5 of malatQ of lii^^e, 2 of maf 
late of potash, 37 of resin, and 5 were lost. \% if probable, that 
the jtli^e of our European euphorbias (spurge^) is siuaijar to that 
of the Indian, which is certainly one of tb^ mQ^t yiple^it dra^tic^ 
and epipastics, < . 

• Myrrh is probably obtained by incision from some plants of 
the genus amyris ; the specimen, examined was in transparent red-«> 
dish yellow tears, with a slightly acrid afid bitter aromatic taste, 
In some of the larger lamps, were white nuclei maiked with 
tines, ^ud more or less opake, which burned with much flame, 
-vihW^ the transparent tears burned like gum : some pieces are air 
most colourless, ^nd /soluble in water, being a peculiar kind of 
gum similar to what exists in the m3'rrh. Aiyrrli, therefore, a^t 
pears to be a very variable drug. 

' 30 gr. of myrrh being distilled, gave 10 gr. pf heavy empyr<i!:r 
tnatic broNvn oil, 10 gr. of a red liquid, which turned syrup of vio» 
lets green, and yielded ammopia on adding potash, and acetate of 
potash mixed witli oil by evaporation, the 7' 25 gr. of charcoal 
Htrere lessened in bulk^ compact, and iridescent, and left on ineine« 
ration. 1*6 gr. of white ashes, which yielded to water 0*07 gr. of 
sulphate of potash, holding a little subcarbonate of potash. Th^ 
Veniainder of the ashfes were totally soluble in nitric acid, emit- 
ting carbonic acid gas with a little sulphuretted hydrogen ; anw 
monia did not precipitate the solution, but subcarbonate of potash 
ilung down carbonate of lime. 

• 50 gr. of myrrh, .distilled with watj?r, yielded a little volatile 
■oil ; the remainder of this distillation passed the filtre very slowly, 
^nd, on being evaporated left 23 gr. of J:ransparent reddish bitter 

• gum, reddening .tincture of litmus^ sind v^liich, on being heated 
"^\tYk boiling water, was Xffi\y soluble in part, for it left a gum. 

like mass, insoluble in water or even weak acids ; this mass w£^ 

very bulky, became brittle by drying, and swelled up in boiliiig 

water. On distillation, subacetate of ammonia was obtained, 

' also oil and charcoal, which burned \f i(b much ease. Weak nitric 



9Cid prodoced from it uxsiUc acid mixed with malic acid, aiu) i^ 
yellow bitter substance that did not detonate. The part that was 
taken up ^y the water precipitated oxalate of lime, from oxalate of 
potrashy it did not render lime water turbid, nor idecoction of gal1« . 
nuts, nor liquid oxymunatic acid. Solution of lead, quicksilver, and 
iin threw down very abundant white precipitates from its sola* 
t^ion ; 23 gr* of this gam dissolved in water, yielded, by nitrate o£ 
lead, a reddish semitransparent precipitate, weighing 20*2 gr« 
'which was not divided by boiling water, but oo adding sulphuric 
acid, part was taken np^^but 5*3^ gr. of sulphate of lead, contain* 
4iig 44ofoxide^ was left on the filtre; l6 gr. of the gum was ob« 
^med by evaporating the solution, it contained an excess of acid, 
but as it did not yield either malic or phosplioric acid by trea^ 
inent with alkohol, the liipein the gum wa& probably united with 
^etic acid, and perhaps by carbonic acid ; for, on adding sul* 
l^uric acid, the solution of gum effervesced and let fall sulphate 
0i lime. 1 he remaining 7 gi* of gum were retained by the nitric 
acid, the subacetate of lead, however, especially if a liule alkali 
1)6 addedy precipitated the whole of the gum. The matter left 
when the residuum of myrrh distilled with water was filtred, 
|>eing dried and treated with alkohol left 6 gr. of gum similar ta 
Ihat just described ; the alkohol, on evaporation, yielded 11*6 gr* 
p( brown r^sin, with an aromatic bitter taste, easily softened by 
Jiandling, melting at 4S° Reaum. not electric by .rubbing. It 
•fliffused an aromatic odour when burned, yielded on distillation 
jthe same products as resins, and formed with potash a soap, 
.^hot»e solution in water passed, but still turbid, through the ^Itar, 
33 gr. of niiric acid at 38^ hydr. poured on 53 gr. of the resiji 
turned it bl^icl^; on hea|;ing the acid, 1'5 gr.of a pale yellow resia 
•rose .to the surface; t]xh mass was bitter; partly soluble in watei^ 
and formed ^ soap* V^ith potash that dissolved easily in watei:^ 
■the solution being transparent and red. This yellow resin con* 
tainedmuch charcoal, it w^s soluble in nitric acid, but not aU 
.tered by it, aind resembled that produced from gamboge. T\m 
.pitric liquor that furnished this yellow resin being evaporated to 
.dryness, yielded another gramme of the same. Lime wator, 
.added to the washings, separates 1-2 gr. of oxalate of limewitb 
a little malate; fy^ supernatant liquor contained a yellow bitter 
matter. 

Myrrh, tjierefore, contains about 28 per cent, of a very fa* 
r §ible bitter resin ; and the remainder is a gum that becomes 
; partly insoluble ; on boiling its solution in water, it yields am* 
. monia by distillation, -as also azofe by nitric acid, and deconopQsea 
• the solntioBS of lead, quicksilver, and tin, by uniting with th^ 
•.pxide. 

I . FrankincenUf or Qlibanum^ Js produced from an African tree, 
/ff^ich Lamarck supppsea to be nearly related to amyris Qilead* 



I 

f0$ Cimfon^m ExanA^Hon of Alc$$, Gmnbcge, 9fe^ 

CKtts* It is yelUrw whit^, dry, brittle, slightly acrid, and are? 
Ktttic, in seiu I trans parent masbes of different sizes, covered with 4 
white powder prpduced by the friction of the tears against each 
•tber. It 18 dilSciiiltly fusible, easily inftammaUe, an^ leaves a 
%Khj leash, 

't^ gr. tif fratokincense disti^lfd with water,, gave I gr. of light 
ve*lauie oil, of the celour and soBell of citrons. Distilled^ per de. 
it yielded much bruwn empyreumatic oil* and but little wateiy 
lUii^t, which did not emit ammonia on adding quicklime, but af* 
ioraed white vapours with nitric acid^ 3*55 gr. of chatcoal re* 
mained, which left 0*55 gr. of ashes, containing 005 gr. of pot* 
ash partly united with sulphuric, muriatic, and carbonic acidsi 
0*06 of phosphate of lime; the remainder was carbonate of lime.' 
' 25 gr^ of frankincense being treated with alkokol, 9 gi"* ^^ a 
whitish matter were not dissolved^ This mass, treated with boil- 
ing water, left 1*3 gr. of a soft grayish gum-like mass, which wa« 
indammable, and produced a greenish resin with nitric acid, s<> 
80 that it might be resin that had escaped the action of the al^ 
kohol. The watery solution left, on evaporation, 7*5 gr. of yel- 
lowish transparent, mawkish-tasted gum, easily soluble in water,^ 
inflammable^ leaving a white ash mostly composed of earbonatii 
of lime; the solution of this gum did not redden tincture of lit^ 
mua, It precipitated oxalate of potash, it did not aSect aicetate of 
lead, but precipitated abundantly, nitrate and acetate of lead, an4 
feitrMe of q«ricksilver ;. the precipitates were white, and entirely 
soluble in distilled vinegar;, it also precipitates decoction of gatl^ 
a»lii, which the gum of myrrh does not. Lime water is not at; 
lleied by it« The gum is carbonised by sulphuric acid, bat no, 
Sbcetotis vapours are emitted; perhaps, therefore, it is benzoic 
acid that saturates the lime in this gum. Treated with nitric 
^atid it yields abont one third of saccharolactic or mucous acid, 
t€^ether with a small quantity of oxalic and malic acids. Tber' 
•Alkohui, with which the frankincense had been originally treated^ 
-iteing -evaporated, left 14 gr. of resin, so that 2 gr. probably vo- 
latile oil^ were lost. The resin was reddish yellow, which cracked 
.fts it cooled, was very brittle, tasteless, rendered electric by fric- 
tion,^ and resembled losin. It grew soft in boiling water, but re* 
^ quired a higher temperature to melt it ; the smell when burning 
wah not disagreeable. Boiled to dryness in a solution of caustio 
potash, it left a residuum that formed an emulsion with boiling 
water. It was soluble m cold sulphuric acid, the solution waa 
fed, and yielded a white pi ecjp^tate wilh water ; M it were heatcfq 
'lot some time, water separated a black resin, soluble in nitHc 
Mid, and changed, by it into a br)>wn, astringent, rather bitter 
mass, whose solution m water precipitated gelatine, but n^t suln 
ybuie of it on. Resin of frankincense, treated with 8 times as 
mach nitric aci<l, was changed into the foriijer resinilerm n^atter^ 



Comp^rMtive ExamUatian of Aloes, GanAoge, t^e* VSf^ 

t^t w^^hings did ndt contain any oxalic acid, bat a residuunt^ 
wiiich being treated again with nitric acid, yielded a bitter mat* 
istv, sokble m water acd alkohol, but part of it !$eparated on tl^ft 
^ater being cooled^ and which precipitated several nieiallic solu* 
tioBs,,$e that it had some analogy Co resino- bitter. 

GdMrnammMiac contains seeds which appear co belong to ^ 
&pecies of ftrola. It fdrms irregular masses, rather transparent 
^n the edges, externally yellowish, internally conchoLdal^ shiningi 
-white, sometimes marbled ; it has very little smell in the lump^ 
|>ut is bitter, nauseous, and slightly acrid. It forms a very white 
emulftion wiih water. It lo^es 6* per cent, by a gentle heat. 2S 
gr. of Hmntooi^ yielded, on distillation, 12 gr. of liquids, mostly 
brown ./empyreumatic oil, which exhaled ammonia on adding 
time» and 7'5 gr. of charcoal, that left 5'2 gr. of ashes mixed 
with daiod, containing 0*15 gr.of phosphate of lime, and 0*3 of 
.«f carbonate of lime* 

25 gr. of gum ammoniac, treated with alkohol, left 5*8 gr. of 
a whiie substance, which, on being heated with water, left only 
2*1 gr« of grayish, soft, glutinous substance, insoluble in water oc 
alkohol, turning black when dried, burning easier than gum, an4 
leaving gray ashes ; nitric acid gives a yellow colour, and pro? 
4uces aliitie oxalic acid. The watery solution left, oil evapora- 
tion^ 4,-6 gr. -of transparent, reddish yellow gum, slightly bitter, 
rather brittle, and drying easier than the other gums, it burn- 
ed without any flame^ and left a wl^ite ash soluble with etierves^ 
'Cence in acids. This gum is totally soluble in water, and. its 
•oltttiun scarcely reddens tincture of litmus, it precipitates sub»-> 
cetate of lead, i)ut not acetate or nitrate of lead, hut sitrate c£ 
quicksilver is rendered milky. It does not render lime-water tw? 
•bid, hence as its ashes contain phosphate of. lime, the phosp^onw 
«eems to exist in the gum combined with the other tlenaents that 
fcanstitttle it. Oxalate of ammonia throws down oxalate ai 
.lime ; but the acid with which this lime was combiaedv is uo^ 
kuawn, althoQgh Vauqiaelia supposes it is the acetic acid that 
.saturates the lime in eum Arabic and gum U'agacanth. It doea 
aot alter decoction ofgalUnuts. It yields with nitric add Euuch 
mueons acid, aome oxalic acid, and very little malic acid. . 

The alkoholic •olutiijn of gum aramoaiac evaporated to 4ry 
Bets, left 17*5 gr. of i eddish yellow resin, transparent, brittle, 
when eoU, like wax, internally uDdalated and shining, marked by 
the nail, and softened in the niouih, or by handling. Ithasoo 
.-sensible taste; it has the smell of gum-ammoniac ; x% is not ren-* 
4er€d eleatric by fr^tion. It melts, like wax, at 43% by a stroog^r 
jieatU swells up, exhales a peculiar smell, and leaves a very- 
spongy liglit c<}al. It is soluble even in oold alkali ; tlie solution 
is considerably bitter, as is the alkaline splutioa of resin. Sul* 
r|ibum«ai4.dMsolve$ thi^a^siay ana water decomposss the Jolu;* 



1 



I 



ioi Comparaiict Examination of Ahes, Gamtdge^ S^ci 

fidn ; if heated, hydrogeniscd charcoal is obtained, whicfai nSixf 
being washed, is soluble in nitric acid, and yields, on evaporation^ 
. in astringent matter, which precijntates glue of a brown colour* 
Nitric acid; heated on the resin, first ields white vapours, and 
then comes a sudden rush of red vapours, a yellow resiniform 
•ubstance is produced; ^hicH re.dissolves durii^g the operation. 
On evaporation to dryness, a very pure yellow, easily fusible, resi-' 
no^bitter is obtained, soluble in alkalies, in alkobo!, and in boiling- 
water» from which latter sbme part is separated when it is cooled. 
It is also partly soluble \tt a large quantity of cold water< All 
Its solutions are 6f a vi:ry beautiful yellow,' which stains the 
bands, and are easily fixed upon wool and silk, so as to produce 
most superb dyes, not alterable by o:tymuriatic acid or even \ht 
dilute alkah^s ; and, considering the small quahtity that is re^ 
quhed of this matter^ they are valua'ble even in an economical 
\iew. When mixed with gum, it yields a purer and more solid 
yellow than gamboge. 

Gum.3nimouia6, therefore, contains 18*4 percent, of gum; 7^ 
df resin, 4*4 of glutiniform niiatter, 6 of wst6/,^^and 1*2 was lostr 
it dofes not contain any extractive matter. 

Swartz observed a mixture of ifltiate of quirksiK'^r, and- gum 
Arabic yielded a precipitate, which Jucks attributed to gallit 
acid contained in the gum, and Van Mons to the decona position 
of the nitric acid and of the metallic oxkie; but it is really a 
coml/imition of the gum with the oxide. . Suijfacetate of lead also 
precipitates both gum Arabic ahd gum tragacantb ; the precipi* 
Kates resemble cheese, and leave nletallic lead on being barned. • 

The resins have not yet been caret uUy examined, and mviiy of 
their properties are falsely stated. Rosin, adiled to a Cold dilute 
solution of potash, was perfectly dissolved, the solution was 
soapy, thick, and drawing into threads like white of egg ; ihe 
most dilute acids produce in it abundant white - precipitates ; 
alkalies, and even neutral salts do the same, by abstracting 
the vfaier from it. ■ A large quantity of common waur also- 
'd»conipc8es it; the precipitate is only partly soluble in alkohol; 
the insoluble portion contains resin combined with lime. Mn- 
'riate or lime turns the solution ot this soap into a whitish soap, 
more or less thick, formed also of rosin and lim^. The metallic 
salts also decompose- this soap,« and some of the precipitates 
might be used in painting. . 

' 50 gr. of rosin, treated with potash, yielded, on evaporation, 
69 gr. of brown soap, dry when cold, rather- bit 'er, and perfectly 
similiir to Starjtey's soap, which might be used in domestic aft-- 
l^irs, us it lathers very well, and washes clean, but it leaves 4n 
the linen a slight smell of rosin which goes oif in the oj^enair.- • 

Volatile alkali^ even when dilate; easily, dissolves rosin ^^tUs 






Mr. ISerari on Muriate of l^fu i6$ 

)MiinlblDa4ion, being diluted with water acquires in time thetbick-> 
pess of starch. 

Obser^ativM.-^GreKt praise is due to Mr. Braconnot, for his 
numerous experiments on the gum-^resins, whose nature was not 
f»roperly understood before his investigation of them, especially 
as the subject did not alfow the hope of any brilliant disco* 
« veries being made, and thereihre the labour must have been un* 
^ertdsen through pure lov€ of the science. 
' The solution of resin, in alkalies, has been already known lA 
this country, by the papers of Hatchett, which have been printtd 
in the Philosophical Transactions. ' 

' It appears, from these experiments, that the violent caustic^ 
euphorbium, has been erroneously considered as belonging te 
this class of bodies, since, instead of consisting of resin and gum, 
ms is tb« case of gamboge, myrrh, and frankincense, it consists of 
jissin,^ wax, and the malates of lime and potash, exclusive of some 
woody'fibres ; gum ammoniac also contains a kind of gluten, id 
additioa to resin and gum. Aloes, that is to say, the Socotrine 
species, is considered as a homogeneous substance, which Mr* 
Braconnot calls resino-bitter matter ; but this part of his papeC 
Is disputed by Lagrange and Vogel, as will be seen in our next. 
• The excellent yellow dye, from gum guaiacum, so highly 
praised by the author, is worthy of the attention of artists in the 
iyifing business, as that colour is usually very fugacious. 

Mr. Braconnot has extended his researches on vegetables, and 
another paper on vegetable acids has reached this country, an 
abstract of Vbich will be given hereafter. 



mm 



€S 



Qfi Muriate of Tin* By Mr» £. Berard.— ^iui/e« de Chimie^ 

vol. 68. 

The usual method of making muriate, of tin, or scarlet compo* 
»tlon;which is of so great use in dyeing, is by pouring four parts of 
common muriatic acid (spirit of salt) upon one of tin, and keeping 
the vessel upon a warm sand bath. The operation goes on very 
slow, hydrogen rendered offensive in its smell, from its containing 
some of the metal, is emitted, a large portion of the acid evapo- 
rates, so that fresh must be added fjrom time to time, and the heat 
kept up fdr some days. In' the cold, th<; solution takes a long 
time ; two months are not sufficient : Bay en and Charlard em« 
ployed six months to complete it. 

' Chaptal placed the tin in the water, in which he condensed 
%ke* vapours of muriatic acid during the process of its preparation ; 
the heat that was disengaged by the absorption^ aided the solu* 

NO. 25.-^.VOL. VI. 2 N . . 



170 Mr. Berari on Muritfte 4>f ibk^ * * 

lion, bat only one fourth of ttn is diB9olved) tkod the MJlatioA Up^ 
be finished in some other manner. 

Tin may also be dissolved, by placing it in a divided state in i( 
receiver, into which the vapours of muriate of soda, 4eeoiapaeed 
1^ sulphuric acid, diluted to 4Q° iydr, are distilled. 
. Oxyiquriatic acid gas introduced into a mixture of tin aa4 
common muriatic acid, hastens the solution very much ; and thus 
iMi acid at ^0^ hydr. will dissolve one third its weight of tin. 

Mixtures of muriatic acid, with from one sixth to one tenth q| 
citric acid, act on tin so violently as to throw part of it ot^t of the. 
vessel^ and produce great heat. One part of aquafortis at Z5\ 
Beaume's hydr., and 12 6f muriatic acid at 20^ dissolves one third 
its weight of tin in a short time, and the solution exhibits 45t 
hydr. 

The alternate action of muriatic auction and atntospheric air 
yas tried, by pouring muriatic acid at 20*^ hydr« upon granulee 
of tin, and after somejbours had [elapsed, the acid was pour«d off; 
the granules, then became black, absorbed oxygen from the air» 
so that a t^per was extinguished by dipping it intp the vessel^' 
and became very hot. When the vessel began to cool, the acid[ 
viQ& poured on the metal again, and this repeated from time to 
time* The first time the acid was f)Oured off, it exhibited 25® 
hydr. ; the -second 35 q ; in two days it attained to 45^» It even 
attained this point in one day, and might be got up to 50^ by 
using a row of basins, so that while the air was acting upon somgt, 
of them, the acid was acting upon others. 

Muriatic solution of tin absorbs oxygen very rapidly ; ' when H 
has absorbed this gas, it will take up a fresh quantity of tin. It 
also absorbs oxymuriatic gas. Pelktier proposed the use of this 
impregnated muriate for dyeing, but the dyers will Aot use iIl 
When much oxymuriatic acid gas has been absorbed, the solution 
will dissolve a fresh parcel of tin, which changes its state, and 
renders it caj)able of absorbing oxygen. 

Muriate of tin at 45 S crystallises by evapoi-atiori, especially 
ijf fresh made, or if it has absorbed much oxygen. The mother 
water, even after several crystallisations, is still very dense^ 
particularly if it was evaporated before it was exposed to the air« 
^ It sometimes is fuming, and will yield crystals again On addin^^ 
water. 

A bottle which contained 1 4 parts of water, held 2S of mi^cr, 
water of the first crystallisation, and 31 parts of that after. several 
crystallisations. The mother waters will absorb oxygen fiofn 
the air and yield crystals afresh ; if they are exposed in a thia 
stratum to the air, the muriate crystallises in very thin ui<l' 
light leaves* They absorb oxymuriatic acid gas with coosidal^ 
|;ble heat, and whei^cuoled form a mass of silky crystals. 
Jliuriate of tin may be puri&d. by redissolutioii in .water an4 



Mk Moikrat en Acetic Acid. itfi, 

^Hfftifl^ation, The crystals ate very soluUe in ^old waler, and 
' ^diminished the temperature 9^ Reaum. Tirhen the substancea 
Vete originally at 5% but water did not produce any c6ld oa being 
naixed vrith the mother water. 

As the mother water began to fume when concentrated, it ^as 
^iatilled ; weak muriatic acid canie over Srsl, and then a white 
tiiass or butter of till wai sublimed. I)ry dxy diuriatic gas passed 
ithrough titeniother water, made it fume, and yi^ld crystals oh 
^bt addition of water ; but the Ainiing liquor of Libavius ekhalea 
thicker and more abundant vap<)urs, and is whiter and denser. 

It Appeto tlierefore that the various muriates of tin always 
)Dontain an excess of acid, and- are susceptible of infinite variety^ 
lieace it is ilo wonder that it produces such unciertaib r^^Ults ia 
idyeing. The white crystals, wiell draiiied, seem the most ton* 
ttant, ttkMl daght i6 be the ohly soibt.used in that art^ being mixed 
"With more or less nitric acid, according to the shade that is de* 
•%ired to be obtained. 

Several difficultiesy lio^ever, have occurred in attempung to 
prepare these crystal^ upon a large scale, for the trade ; the 
toanner in which they were overborne, will be explained ia a fu- 
iwre e^say; 

Obietteklons.'^Tht importance of tiii in dyeing scarlet, aiid the 
tlifficttlties attending ife being properly prepared for that purpose, 
are so great, that every step towards the knowledge of the salts 
bf tin, must be esteemed of great consequence in the art of dyeing* 
The experiments of Mr. Beirard are therefore valuable, particular* 
ly his mode of accelerating the action of muriatic acid upon the 
tnetal, by pouring it off, and exposing the tin to the codtact of 
ihe air, as this method niight be applied with advantage to 'some 
bther alow diesolutions, silch as *that of copper in vinegari for tha 
tnanufactare of crystals of Verdigrease, 

'Observaiian$ on- jfcetic Acid, . % Mr. J. B. MoVt&AAT.— i^im. if» 

bhimicy tW. 66. 



♦ • 



T^B density 6i acetic acid is not the measure of its strength^ 
for two specimens of the acid, whose specific gravities were boti^ 
J "069 at 12'^5 Reaum. contained different quantities Of r^l acid'. 

The first was the strongest acetic acid that could be obtaihed^ 
'it C6nXaitaed ^*I25 pet* cent; of acid, and 12'S75 of tiratef ; 100 
ptttU of it saturated 250 of crystallised subcarbonate of soda; it 
^Ma withotit any empyreuma,* crystallized between 10 and 11^ 
Reaum.,' and melted with diflkalty at 1 S"". It distilled very f^s^ 
even widiout boiling. 

The aecond was formed from the first^ by adding a quantity of 



i27$ ObsercatioM im Acetic Add. 

.water by cakulation. It contained 41*275 p«r cent pi acid, an^ 
,:i»87S5 of water. 100 parts of it saturated 1 1 8 of crystallised 
•BuVcarbonate of soda. It did not crystallise, when cookd several 
degrees below the freezing point.' 

It had been previously remarkedy that the above strong acid, 
exhibited only 9^ hydr., whereas another acid at il^'l bydr, was 
BQt crystallisable.even at 49 Reaum., and saturated only 1B6:j25 
ipf subcarbonate of soda, it was therefore conceived, that the acid 
Itself is more dilatable than water, and that a term existed, C43|g» 
nisabie by the hydrometer, at which this superior dilatability 
;Wovild exert itself, so that the strength of the acid would be exhw 
•blted by the inve^ $e. progress of the hydroaietic indications. 

Water therefore. was gradually added to 110 gr. of ibe strong 
acid above described, and its specific gravity .was carefully* ob^ 
.served at each successive step^ as sQon as the acid had- cooled t# 
il^'S Reauniurv 
Water added lo. gr, spec. grav. 1*0742 or 15f -6 hydF. 

ia-5 . V0J7 11- 

., . 10- i-ozpi 11-S_ 

. The acid had now attained its densest state, and the additioB 
of water began to lower its specific gravity, at which tioiQ it eeft^ 
tained 67*25614 per cent, of acid^ and 32*74386 ol^ water, 
t JO-5 10763 10*9 

12* • ^ 10742 10*6 

11*5 1072a - 10-4 

Si- 1*0658 9-4 

11- 3 0637 9*1 

.. 37* 1-063 9* 

Each addition of water raised the temperature of Uje^mixture. 
The^addilion of 29*54 grammes of water to 100 of the strong 
acetic acict, raised the temperature from 12*^5 Reaumf to 13°'5 ; 
a fresh addition of 72*46 of water, carried it up to 15.-5, ^ 

0^«!rt«fw)«<.ii-These experiments are <yntrary to the received 
opinions of the gradual diminution of specific, gravity by the ad* 
dition of water to acids. Berthollet, in a note, says he Bas re* 
peated some of these experiments, and that the resdlts have been 
but slightly different from those of Mr. Mollerat^ who ift alfeady 
Vnown as a manufacturer of charcoal and other producits^ as may 
De seen by an abstract in the present volume of thevBubrospecty 
f. 100. . .. 

i It. id not s^id whether the acetic acid, whose densities wer^ 
examined, was jprepared from, vinegar or wood; we. suppose it 
was made from the latter, as Mr. MoUerat manufacj^rea. whttl^ 
was formerly called the pyrolignic acid under tbattnam^* 



/ 



C •«?» i 



jsm 



jleport made by a Co)nmUee bf the InstitufCf on Mr. Carduddu*s tdst 
Memoir. By Mr, Dbyjbux,— -j^n». de Chim. vol. 6§« 

Ik two papers presented to the Institute, Mr. Curaudau has 
given a vefy positive opinion on the possibility of deeotnpo^ing 
soda, potash, phosphorus, sulphur, atid iron ; aud has mentioned 
'Vtevtnd exj^eriflEieiitSy from whtnce he draws a conclusion, 'that 
chemists may not cmly decompose . iron and sulphur, but' it was 
iJso in their power to proditce them from their elements; ' 

The committee however soon fomid that the author hbd been 
imposed upon by some appearanaes in bis" experiments ; but a^ 
Mr. Curaudlfcu was still unconvinced of his error, he was invited 
pt bfi present at the repetition of the experiments which he con. 
ceived to be.o^' the greatest consequence, to produce, in fact, phos- 
phoniis^ ii:on, and limei from sulphur, potash, and charcoal made 
jOrom horni . 

Tboreiepieriraent did hot succeed, Mrhich he attributed to the 
lurpacjB in. the Medical School not being so powerful as his own. 
The next day Uierefare the eomoiittee met in his laboratory, and 
th^ experioient made vtrith the .materials provided by the institute, 
t{fl#:e^uaUy unsucceesltil ; but .on 'trying it with the saiOfe mate, 
rials which Mr. Curaudau had used in his experiments, much 
fbUBphofeteevt gas wad emitted, phosphorus combinedwith about 
one half of sulphur was colleoted, and- the residuum contained 
lime.andi^^io, as. Jbe had affirmed. ■ , ^ 

On examining the animal coaly however, It was foundT to con. 
;^in.40 pet cefit.' of phosphate of lime,, mixed with a little phos- 
phate of iron, 1 and even more of sand, and 0*69 of carbonate of 
iime;. It wa^theu discovered that the coal had in fact heen made 
^om raspings of horn, ivory, and other substances, thataJabour* 
er had been empUyed to convert! these into toal, and that it had 
l»een trittiuratedlipon a marble slab. 

Mr. Curaddaa was therefore convinced of his error^ and it is io 
be boped that he will no longer, be temf)ted to publish any moi^ 
4i|K>n these di^cult points, which be bdieved himself td^^'hive 
4rea(ted mth auceess^ and in alL cases he is entreated to bestow 
more litCeAtioQ in the reseaii:hes he ^ wishes l;o submit to the ta^ 
ititute. . f '' •* 



«i»< 



, Ob$eroQik»(U*^T\aB vety severe check given to Mr. Curaudaiii 
^U, we hope, render him more cautious in future; there- WtM 
c^rtaidy no precision in his experiments, but the deductions^ 
wei(e dnemn from analogy, and exhibited a picture of chemical 
rASearebes as they wera^onducted before Cramer, Margraff, a«f|; 



'it'i On preparing liquH Sugar from Applet or Peari. 

the other German authors had introduced the same minute att</D« 
lion to the freight of the products, and their agreement witfi 
that of the original materials, as was formerly thought to be he* 
cessary only, in assaying for the value of gold. 

cggatt—eeBBqB i i ■ ■ BSSSmBBBsmsaamsmmmmeamBdmaieeiaaBmi 

On the Pjr^aration of liquid Sugatfrgm Appkif or Peari^ J5y. Mr* 

DuBUC.-^-<f««..<fe Chim.td, 68. 

Si^v&i^iiL establishnieRts have been tncitde m the sonth ol 
France, for making fiugar from grapes, it is therefore desired td 
communicate the same^adranUige to the North of France, al 
apples and pears will prbduce sugar, v/hese ta^e is equsdiy agree- 
able as thfit of gr&pesj and cqiially cheap. 

Eight iiuarts of the full ripe juics of apples called ortrnge^-vrnt 
boiled for a quarter- of an hour, and 40 grammes of powdered 
chaik added to it, and ibe bailing oontinued for lO ttntiutes longer. 
The liquor was , then clajriiied by' the whites* of S «ggs, and the 
liquor was strained twice through flannel, and afterwards reduced 
by boiling, to one half of its former bulk, and the opertftion finish- 
ed by a islow heat until a thick pellicle rose on the surface, and s 
quart of the syrup weighed ISt lb. 10 o<. By this means 3lb. of 
liquid sugar was obtained, very agreeable in taste and smelly 
which ^sweetened water very well^ aad eVett milk witbdat tiifi* 
ling of it. i • 

5 qearts- 6f ttie jjiibe of applto called dous leoaq^ yielded 
by the same process, I21b. 12oz. of liquid sugar; 

8 quarts of the juice of the. sour apples^ tailed Hmit m^tleif 
yielded 21b. lOoz. of good sujgar. 

8 quarts of the juice of the watery lipples' eallifd Grr^M-^^^ yi^^ 

cd dlb. and a Mf- 
25 chiliogr, or 50lb. of the Ahove 4 apples yielded nearly 4^ 

lb. of juice; which took 3oz; of 'Cfaalk, and the white of 6 ^ggsf 

and produced more than 61b. of excellent liquid siigar. 

Ill order to do without whitti of eggs, 901b. of the jaicef 6f the 

above apples were saturated with li drachms o^ chalk, andre^ 

peatedly strained through flannel, but it wae still thick, and dte& 

amaable to the taste. 13 drachms 6f charcoal pdwder w^retbeii 

l^ojed,' and the .whole boiled for about 10 minutses, and thai 

aj^isaiiied twice through a flahnel ; it was then 'cletfr^ but higfaef 

€olo^red than usual ; but it produced very good sugar* 

6 quarts of apple juice, were treated with 7 drachms of chalky 
^nd tm* of baiters' sixxali ctml, pxeviowiyi^AFcbsSied- limit it no Ibn^ 

pit coloured the water. 

1^ A|aar|s^ of apple JAiice of several di^erent kinds, undin-difl^tlit 
fU^ges-of ripenessj of which one third was dtnll soilr, *were S8tu£ 
|»|ed with 12 draehnid of chdk^ and clarified ^ith tk^^wbit^'df 



» 



' On preparing Kf^id Sugar from J]^pHa or Pears. 39^ -^ 

6 <Qg£^? some inalate of lime was deposited in small crystals U^ ^ 
yf^rSi iht end^and separated by passing the syrup very; hot , 
f,})rough . the' fl^ppel j very near 2ib. and a balf of sugio' wer^ • 
pbtained. 

Iplb. of bruised apples, similar to the last, were left to mace^ 
laie for 24 hours, and 4 quar^ of the juice were treated ^jkh 4 
drachms of chalk and the white of an egg ; it yielded lib. 602, 
of liquid sugar, so that the maceration had oeen of senrice. ' 

24lb. of pears, called pilk^Cy yielded 9 quarts of juice, which, 
required IS drachms of chalk, aiui the white of $ eggs, and yield- 
ed about 24oz. of sugar, which was less agreeable to th^ I49t9'< 
than that of nf|e apples, 

6 quarts of juice f^pom one part of ^the above pears^ and fwo of 
ripe apples, orange and girard^ treated with % draohhis of chalk, 
and the w^iites of 2 eggs, yielded 2&>z. pf very fine tasted ^ugar, 
f uperior to the preceding. 

6 qiiarts of juice of an equal quantity of apples and pears treated 
with 10 drachms of chalk, and loz. of prepared chaixroal, depo* 
^ited some nlalate of lime, and yielded a sugar rather darker than 
%he preceding, but very well tasted. 

Cadet de Vaux says that apple juice does not curdle milk, and 
tbat a small quantity of chalk added to it, destroys some part of 
the taccharitie principle ; but S quarts of juice from ripe apples,- 
called 0raff|r^, which was evidently acid, as it cuidled milk, and 
reddened infusion of turnsol and that of violet, was treated with 4 
drachms of chalk, and the white of an egg; it yielded !2^9z^of 
syrop, between 32 and 53^ bydr. which did not curdle milk/ 
Another S quarts of the same juice, evaporated to three fourths 
of its volume, and strained, yielded 23oz. of clear syrup, which 
curdled milk, was browner than- that of the neutralised jniee/ 
aod approached towards treacle in smell and taste. Perhaps* 
the apple called Jean^hure^ used by Mr. Cadet, possesses 
the valuable properties of furnishing good sugar by mere evapo« 
ration. . . 

- It is necessary to observe, that unless the fire is slackened 
towards the end, the syrup grows brown^ and acquires the tast^ 
and smell of btartit sugar. ^ - 

' A cwt of^ apples yield about S4lb-. of }uice, which pt<Mint& 
nearly 12U>. of liquid sugar; supposing, therefore, the avera^ge^ 
price of apples to be 1 fr. 20 cent. (Is.) the cwt. and the charges 
a^nount to 40 cent. (4d.) good sugar may be prepared for 3 or 4^ 
sibls (%d.) per lb. The only extra apparatus necessary is a cou«' 
pje of copper evaporating pans. 

.^VMMM. ■■■•■■■■§ 

" 4Jkgervaiiotn$.*^We- are here positively informed, tbat tntftufac* 
Tories of grape sugar are established in the saulhern parts i^f^ 
jRroBce; which shews that at the present prices the manufactare* 



QfS ' Analyris of three Kinds of Pyrites'. 

i^W answer, and we apprehend that it wBl prove a fbrpiidable 
rival to the caue sugar, even when the seas are opened. As to 
apple aii^ pear sugar^ or rather white treacle, the prospect is not 
so promising* 



iSBsoisam&mssssssssssssissssssssssgssesammmmmammL 



Analyu$ of three kinds of Pyrites, By Mn BvcHOLz.-t< 

Ann, de Chun, vol, 68. 
. The analyses hitherto published of pyrites with a maximiini oi 
sulphur,, are as folbws : 

, Proust, * f 4 

Hatchett, • • 

Gui^iive^u, ,, 



Iron. 


Sulphur. 


4»736 


. 52-64 


5a-24 


. 46-76 


52-76 


. 47-2a' 


52-76 


• 46-6 


hS'69 


. 46ai 


47-93 


. 52-07 


.47-36 


. 52-64 



. Bucholz and Gehlen, artificial, 

Che- usual process is to treat the pyrites with dilute nitric 
acid, but this requires a long time, and much acid ; the following 
method was therefore adopted: 100 grains of the pyrites were 
reduced to powder, and mixed up with half an ounce of 
water in a high vessel l^olding a pint, knd concentrated nitric* 
9cid, prepared according to. Suersen's method, was dropped upon. 
U* . The action of the acid was very violent^ but the pyrites 
wHs completely oxidised in less than half an hour, with the ex* 
l^noe of about 1 1 drachms of the acid. 

: 100 gr. of greyish yellow pyrites, of a euUc ibrm, which 
3^ielded a blackish grey powder, being treated in this mannar left< 
4 gr..Qfj,siIUacovjered with^oxide of iron. The solution wasr 
4iluted,with water, and precipitated by muriatei of barytes; it 
yielded 355 gr. and a half of sulphate of barytes ; now as this 
salt contains, according to \Yithering, Rose, and the author'3 own 
experiments^ 35*2* per cent, of sulphuric acid, and 67*5 of 
barytes ; and on the other hand, the analysis made by Richter, 
Klaprotb, and the author shew that sulphuric acid contains oa 
an average 42*5 per cent, of sulphur, it will follow that this 
pyrites contained very nearly 5i*15 per cent, of sulphur. 

100 gr. of cubical pyrites, with concave surfaces, and tlie 
edges slightly truncated, left 4 gr, and a half of insoluble mattisr 
aod oxide of iron ; the sulphate of barytes weighed 358 gr. $a 
that the pyrites contained 51-77 ptr cent of sulphur. 

1 00 gr. of radiated pyrites left only 2 gr. of insoluble matter, 
and the sulphate of bar}^tes weighed 352 gr. so -that the pyrites 
contained .49*61 per cent of sulphur. 

The average of these aQ^lyses is, 51 pei ceut..pf ^plph^rajid 49 



Analysis of British and Foreign Salif ^c. i7t 

«f iron^ being nearly the same as was given by Hatchett and 
Gueniveau. Proust and the author had used artificial sulphur«t, 
which always contains some sulphurct with excess of sulphur. 

It is evident that the pyrites that have been examined by va-, 
rious. chemists, and in different countries, all belong to the same 
fpecies. 



Ssssmimm 



On a Powder sold as Ipecacuanha. By Mr. Hehri. — dim^.d^ 

Chim. vL 68. 

EoR the last three months the tirug.brokers have hawked about 
Paris, * a powder which they sold as powder of ipecacuanhai 
taken out of an English prize. On examining this powder, 
the presence of emetic tartar was easily discovered by mixing 
it up ^vith a little cold water, and adding some hydro-sulphu- 
iu.:„.i^ted water, which'immediately produced an orange colour ; 20. 
grammes of the powder being calcined, yielded 0*85 gr, of gray/ 
oxide of antimony. It wai^ evidently a mixture of emetic tartar^ 
with some vegetable substance of no sensible qualities . 

It is therefore liecessary to be very cautious of purchasing 
medical articles from drug-brokers. 

The general board of civil hospitals at Paris, prepare under 
their own inspection, the medicines they distribute to the 
]iospitals.N 



Obsercaiions »^^Thert is reason to apprehend that most of the 
|Hilverised drugs, and pharmaceutic preparations sold in this 
country, especially for exportation, are like the above powder,' 
meVe suceedanea, and made up of a few cheap and powerful me*, 
diciues. 



nMaHHHMMHaHHHHMIBHBBBHVeaBBMnHBBBHBaHMHBia 



Analysis •/ British and Foreign Salty with a view to their fitness fyt- 
Economical purposes. - By Dr. William Hsnrt .—-PAi/. Trans. 
1809. 

A DECIDED preference has been given to foreign salt prepared 
in warm climates by the spontaneous evaporation of sea water, as 
8i preserver of animal food, and great quantities of it are imported 
into Great Britain; it was therefbre of importance to determine 
^whether this preference was well founded. And if British manu- 
factured salt was really inferior to foreign salt?* to tiscertain, as 
the basis of all attempts towards its improyement| in what this 
inferiority precisely consists. . 

JJo. 2.— VOL. VI. L 2 



SrS Analysis ^Britiak and Foreign Salty ifd 

Cheshire stefoed^ or lump sait^ is made from brine by a boUing 
heat (i*. «. 5226° Fafir. in faOy satCfrated brine) until 6n]y so mucb 
water is left as is barely sufficient to cover the small fiakey 
crystals that have fallen to the bottom of the boiler. The salt is 
then put into conical wicker baskets, and after being drained, is^ 
dried in stoves, Where it loses about 1 -7th of its weight. - ^ . . 

Cheshire common salt is made from brine boiled until it is 
brought to th; point of saturation, and the evaporation linishedby 
a heat of IffO^ or 170° Fahr. It is in quadrangular hoppers, 
close and hard in their texture ; it is drained but not stoved. 

Cheshire large grained Jlakey salt^ is made from* B»riue evaporated 
at a heat of 130° or 140° Fahr; It is ' rather harder than com- 
mon salt, and approaches to a cubical form. 

Cheshire large grained ojr Jishery. salt is made from Oriiie evapo-* 
rated at a heat ot 100© or 1 lO^ Fahr. the proems lasts for fi 8, 
or even 10 da}S, and the salt forms in large and nearly cubic 
crystaT^. 

Stored salt Is sufficient for dbmestic usies; common salt it 
adapted fof sCrikiog and salting provisioas not intended for sea 
voyages or Warm climated ; for which purposes the large graiaed* 
dr fisfiefysafft is peculiarly fitted- 

On the first -application of heat to the brine, a deposit is 
formed, whic6 is either removed by skimming, or allowed to sub^-. 
side along with the salt fiist formed and then raked nut. Some 
brines scarcely require any of this clearing of the pan ; some part 
ho>^ever sticks to the bottom, and becomes very hard, so that 
the panscale, as it is called, must be removed by violence once ia 
three or four weeks. 

In Scotland the sea water is evaporated from first to laat by a 
boiling heatVso that the salt produced approaches te^the eliaractes 
of stoved salt ; but iu some places the fires being slackened be- 
tween Saturday and Monday, the crystals are considerably ior 
creased in sizre, and the salt is called Sunday salt. 

At LymingUm the sea water is spontaneously evaporated in 
shallow pits to l«6th oliu bulk before it is brought into the boi^i^ 
lers, where the remainder of the water is entirely evaporated, and 
tli0 whole mass of 6alt taken out at once, and removed into 
troughs with holes irt the bottoms, thfough which the Bittern or 
bitter liquor drains into pits. Under the trougba, and in a line 
with the holes, are &ced stakes on which a poition of salt crys* 
tallises. These salt cats, as they are called, weigh about 60 09 
80lb. When the manulacture of salt is suspeaded'by the coldness 
of the weather the bittern is evaporated, during which, some 
common salt is separated aiid reserved for the purpose of concen*- 
trating the brine in summer. The evaporated brine is thei» 
removed into coolers, where, if the weather prove cold- and clear,. 
Kpsom salt crystallises, tht qnaiitity of v^hiah is about l-M^ ^ 



Anat^jtis Of British and Foreign Salt, Sfc, 279 

i(He! boiled liquor, and 4 or 5 tons of it are obtained from a 
fluantity of brine, wbich has yielded 100 tons of common salt and 
<me ton of cat salt. This single Epsom salt being again dit* 
solved and crystallised, is called double £p8oni salt. As Bergman 
had erroneously excluded sulphate of magnesia from the cbmposi- 
iioa of "Sea -water, liis authority has led Aikin to suppose that 
either sulphnric acid, or some sulphate must be added to the 
bittern to manufacture Epso.m sal^t, which i^ not the ca^e. 

In Cheshire the water of the river Mersey is saturated wit^ 

• rock salt, so that 100 tons of brine will yield at least $3 tons of 

common salt, whereas the same iquantity of sea water with an 

equal expenditure of fuel would ^produce only 2 tons l^.cwt. of 

JtalU 

Some attempts have been lately made jto nse rock.salt cr.ushcd 
between iron rollers to the packing of prov^s^ns ; but the results 
are not perfectly known. 

A large proportion of what is sold in London ^s jbay salt is 
Ohetfhtpe lal^ge grain or fishery salt : the foreign hay salt is pre- 
pared by the spontaneous evaporation of sea-water, exposed in 
shallow pits to the sun and air. 

St Ube's bay salt contains 9^0 parts in 1000 of muriate of 
Soda» 4| of sulphate of magnesia, §3-| of sulphate of lime, 3 of 
muriate of magnesia, a trace of muriate of lime, and .0 of insoluble 
matter. 

St. Martinis bay salt contains 9^9 j ^^^* of soda, 6 sulph. of 
jnagnesia, l^i sulph. of lime, 3| mur. of magnesiai a trace of mun 
oflkne, and 12 of insoluble matter. 

Oleron bay salt contains 9^*4^ mur. of soda, 4| sulph. of.mag* 
nesia, 19| sulph. of lime, 2 mur. of magnesia, a trace of mur. of 
iime, and 10 of insoluble matter. 

Scotch common salt contains 935| mur. of soda, l/^l sulph. 
of magnesia, i 5 sulph. of lime, 28 mur. of magnesia, and 4 of in- 
soluble matter : the quantity of muriate of, magnesia is, how* 
aver^ vBTj variaUe, 

Scotch Sunday salt contains ^7)^ niur. of sod^, 4| sulph. of 
magnesia, 12 sulj^b. of hme, llf mur. of^nagnesi^ and 1 of inso<- 
lubk matter. * 

Lymington common salt.contains 937 naur. of soda, 35 sulph. ojf 
jofiagnesift, 15 sulph. of lime, ^1 mur. of .magnesia, and 2'of xnsor 
Idble matter. Here also the qu^mtit^ of muriate of magnesia if 
!i^iable« • 

. .Lymington cat salt contains 9&8 ,mur« of soda,. 5 sulph. <ii 
jmagnesia, 1 sulph. of lime, 5 mur. of magnesia, and I of insoluble 
patter. 

< , Cheshire crushed rock salt contains 933| mur. of soda, 6^ snlph* 
of lime,3-l6ths mur. of magnesia, l-16th mur. of lime, and 10 of 
sAsoluble matter. 

Cheshire fishery salt contains 98€| mur. of soda, 11| sulph. of 



2S0 Jnafysis ofBrUisk and Foreign Saltf tfc» 

lime, I mur. of magnesia^ | mur. of limei and 1 of insoluble 
matter. 

Cheshire common salt contains 983| mur. of soda, 14^ sulph. 
of lime, i mur. of magnesia, \ mur. of lime, and 1 of insoluble 
matter. 

Cheshire stoved salt contains 982f mur. of soda, l^ sulpb. 
of lime, I mur. of magnesia, | mur. of lime, and 1 of insoluble 
inatter. 

The insoluble matter in foreign salt is chiefly argillaceous earth 
coloured by oxide of iron ; in sea salt prepared by rapid evapora* 
lion, it is a mixture of carbonate of lime with carbonate of mag- 
nesia, and a fine silicious sand ; in that from Cheshire brine, it 
is almost entirely carbonate of lime ; in the less pure species of 
rock salt it is chiefly a marly earth with some sulphate of lime, 
and its quantity varies from 10 to 45 parts in a thousand. Go. 
vemment allows 651b. for the legal weight of a bushel of rock 
ealt, instead 561b. 

The earthy muriates seem to be derived from the mother liquor 
that adheres to the salt. They scarcely, form 1- 1000th pari of the 
Cheshire varieties of salt ; and indeed if the brine be evaporated 
to dryness, it does not contain more that 5 parts in 1000 of 
earthy muriates, whereas the entire salt of the sea water con* 
* tains 213. 

That sulphate of lime is found in a larger proportion in baysalt, 
than even in those that are prepared by the rapid evaporation of 
sea-water, seems owing to its being either separated from the lat- 
-ter brii^es in the clearing of the boiler, a process which cannot be 
performed in the clay pits, or to its entering into the composition 
of the panscale. The proportion of it is very variable, de- 
pending upon the period in which the salt was extracted from thjc 
boiler ; for common salt taken out two hours after the first ap- 
plication of heat, contained l6 parts in lOOOof sulpbate of lime>; 
four hours, 11 parts; and Q hours, only Z\ parts. On the other 
band, the contamination of salt with the earthy muriates increases 
as the process advances. 

The several varieties of salt, appear to. contain nearly the same 
quantity of water after they have been dried by a heat of 212^ Fahr« 
Pure transparent rock sail did not lose any of its weight in a low 
red heat, nor did it decrepitate like the artificial varieties when sudw 
denly and strongly heated. The salts that contain muriate of 
magnesia are decomposed and deprived of their acid by a I6w 
red heat ; large grained fishery salt loses about three parts of 
i^ater in 100 dry salt; St. Martin's bay salt the same; Oleron 
bay salt 2| ; "Cheshire common salt 1^ ; Cheshire stoved salt J» 
The loudness of the decrepitation was in the same order, and 
most remarkable in the large graiued varieties. 

The proportion of the other ingredients in the muriate of sode 



Analysis of British and S0reign SaU, Sfe* 2S1 

contained in these salts appeared, from experiments respecting 

the quantity of fused luna cornea that they would produce, to be. 

really the same in all, and the differences existing between them 

for aconomical purposes do not depend upon any difference in 

their chemical compositioh, but on the magnitude of their crystals 

and their degree of compactness and hardness. Quickness of 

solution is, in similar circumstances, proportional to the quantity 

of surface exposed, and therefore since the surfaces of cubes are 

«s the squares of their sides, a salt whose cubic crystals are of 

a given magnitude, will dissolve four times more slowly than one 

urbose cubes have only half that size ; of course the large salt, 

when used for packing provisions, remains permanently between 

the layers, or will be very gradually dissolved by ibe exuding 

fluid ; on the other hand, the smaller grained salts answer equally 

well, if not better, for the purpose of preparing the pickle, or strik* 

ing the meat. 

It was conceived that the hardness and specific gravity of the 
- several varieties of salts might be, in some degree, connected, 
Muschenbroeck makes the specific gravity of artificial muriate? 
of soda to vary from 1918 to 2148, (water being lOOO) the mean 
of which is 2033; Sir Isaac Newton states it at 2143, and 
Hasseufratz at 2200. 

• A piece of foliated rock salt, perfectly transparent, was weighed 
in alkohol, and its specific gravity was found to be 2170 ; a less 
pure specimen, more approaching to a fibrous fracture, had the 
specific gravity of 2125 only. 

The specific gravities of the artificial varieties were investigated 
by using a glass globe, with a long stem or neck ; the globe held' 
16 cubic inches of water each weighing 252^ grains at 60** Fahr* 
and from the line where the water stood in the neck about half * 
an inch from the globe, the stem was graduated upwards into 
100th parts of a cubical inch. Sixteen cubic inches of perfectly 
saturated brine was poured into the vessel, s^id 400 grains of 
the salt to be examined was then added, and the air adherent to 
the salt dislodged by agitation. The 400 grains of the less pure 
rock salt broke down into small fragments, occupied 75-lOOths of 
a cubic inch, hence its specific gravity was 2112 ; stoved salt, 75^^ 
sp. gr. 2112; another sample of stoved salt, 76, sp. gr. 2084; 
common salt 76, sp. gr. 2084 ; grained fishery salt 83, sp* gu 
ISO9 ; another sample the same ; St. Ube's bay salt 32, sp. gr# 
1932. Hence the specific gravity of rock salt appears to be di- 
minished when broke do>yn, probably in consequence of the air 
which the fragments envelop, and which cannot be entirely se- 
parated by agitation. The smaller grained salts are however 
certainly specifically heavier than those which are composed of 
larger and more perfect crystals. 

These experiments show that little or no difference in specific 



282 An/ilysis of British and Foreign, Salt^ Sfc» 

gravity is discoverable between the large grained salt of Britislit 
and that of foreign manufacture, and even if no superiority be 
♦laimed on account of tfie greater chemical purity pf British s^lt, 
it may safely be asserted that the larger grained varieties are 
fully equal to foreign bay satt as to their mech^ical properties, 
and the prejudice in favour of the latter may be discarded a^ 
imaginary, ' 

The method of analysis adopted in examining the several 
varieties of muriate of soda, was to pour 4 oz. measures of al« 
kohol upon 1000 grains of the salt (dried at ISO*^ Fahr. for 2 
hours^ digest th^m for some hours, and wash the undissolved 
portion with four ounce-measures of alkohol ; by this means the 
earthy muriates were separated and their quantity could be as* 
certaified by ulterior experiments, for which w« must x/^v to 
the original. The undissolved residuum was treated with 16 oz, 
of distilled water, and the still ipsolpble mat^ washed with fresh 
additions of water. The solution was precipitate^ by c^rb&nate 
of soda, and the precipitated earths were treated with an excess 
of sulphuric acid, which excess was afterwards got rid of by. 
evaporation to dryness, and the total weight of the sulphates 
ascertained, to which that of the earthy muriates, and xnattet 
insoluble in water being added, the remainder was assumed as 
that of the muriate of soda- contained in the salt that^ was ex* 
amined. 

' Various curious methods are mentioned by which the propoc'* 
tions of the several ingredients were corrected, but they are loo 
long to be here inserted. It is suiScient at present to remark tha| 
the proportion of the. earthy muriates heretofore given is in fact 
only 5-6ths of the real quantity. 

Some brine from North wich pumped out of a mine of rock salt 
into which water had been allowed to flow, and which was of 
covrrse perfectly saturated, had the specific gravity of 1205 
at 5€? Fahr. Eight ounce-measures, evaporated to dryness yielded 
1 230 grains of salt which contained 2 parts in 1000 of caihouate 
of lime and oxide of iron, 5 of the muriates of lime and magnesia 
in nearly equal proportions, 19 of sulphate of lime, and 97^ o£ 
muriate of soda. 

The mother liquor or brine that remauiSt after all the comnioii 
salt which.it is thought worth while to extract is separated, had 
the specific gravity of 1208 : the dry salt from it contained 35 
of muriate of magnesia, 32 of muriate of lime, 6 of sulphate of 
lime, and 9^7 of nluriate of soda. 

The clearings of the brine contained SCO of muriate of soda^ 
41 of carbonate of lime, and 15^ of sulphate bflinie. 

One specimen of panscale contained 950 of muriate of soda, lO 
of carbonate of lime, and 40 of sulphate of lime. This variety 
is for med when |;he brine being perfectly saturated does not dis- 



Anafi/sis of British and Forci^ Saliy ^-c, S8S 

solve the muriate of soda carried down with the sulphate oT 
kxne. 

Aootfaer s|»ecim«n ofpanscale contained 100 of muriate of soda, 
1 10 of carbonate of l^ine, and 790 of sulphate of lime. This 
i$ forn)«d v^ben ihei^rifie is not saturated and of course acts, when 
admitted into the pan, upon the muriate of soda which the pan- 
scale contains^ . 

Salt oil, or mother li<quor of sea water from Scotland, had the 
sptoci^c gravity of IS^f, the dry saJt of it contained 874 of mur 
hate of magnesia, 70 of sulphate of magnesia, and 56 of muriate 
•f sodfei. ' 

Salt brme, or liquor that [drains from Scotch salt, had the spe- 
cific gravity of only 1158. The dty salt of it contained 205 of 
muriate of magnesia,*! 3 5 of sulphate of magnesia, and 660 of 
muriate of sodcu 

The mother liquor, or bittern pan of Lymington had the spe- 
dfic gravity of 12S0; a -quantity of sulphate of magnesia ht«l 
crystalhsed in the bottle. The dry salt contained ()40 of muriate 
(of magjiesia,>2()0 of sulphate of magnesia, and 100 of muriate of 
soda ; so that it dift'ered very mu^rh from the similar fluid sent 
from ScotUnd. 

• Lymington pansc^le contained 29 muriate of magnesia, 1 8 of 
desiccated sulphate of magnesia, 127 of the carbonates of lime 
and magnesia, 2l6 of sulphate of lime, and 6l0 of muriate of 
soda. 

From the very near approximations of the proportions between 
the sulphate of bary tes and ammoniaco-magnesian phosphate ob- 
tained in the analysis of all these products of sea water, to those 
which result from the decomp6sition of two equal quantities of 
sulphate of magnesia, it may be inferred that they contain no 
sulphate of soda, which was particularly searched for, because 
it is stated to be one of ibe ingredients of sea water, by the 
Bishop of Llandaff, and other chemical writers- 

Obferoationsj-^Jht above experimental investigation of the most 
generally useful salt, is highly important in a commercial and po-^ 
litical view, as it tends to exempt us from the tribute we have 
long paid, voluntarily indeed; to foreigners for bay salt, which we 
do not hesitate to say, in more positive terms than the modesty 
of Dr. Htnry would permit him to use when speaking of his own 
experiments, is here demonstratively proved to be injerior to salt 
ctf our own manufacture. 



aavatMBsneB 



Qn tJie Loss o/JFeig/U -which takes place in cmtking jinimal Food.^^ 

PkU. Mag. No. 14S. 

Is whatjfever way the flesh of animals is prepared for food, a 



i84 Thj Jrt of Printi$ig (M Sion^y SfC, 

considerable diminution takes place in its weight. The foHowhig 
experiments were made in a public establishment to serve a pur- 
pose of practical utility. 

28 pieces of beef weighing 2801b. lost in boiling 73lb. 14of . 
or 26f per cent. 

19 pieces of beef weighing ipolb* lost in roasting fillU $oz» 
er 32 per cent, 

9 pieces of beef weighing 90lb. lost in baking 27lb. or 90 
per cent. 

- 27 legs of mutton weighing 260lb. lost in boiling, and by hav.* 
ing the shank-bones taken away, 6Slb. 4oz. ; the shank-bones 
were estimated at 4oz. each, so that the real loss by the boiling 
was 5'5lb. 80Z or 2li per cent. 

35 shoulders of mutton weighing 3501b. lost in roasting 109lb« 
lOoz. or 3 li per cent. 

16 loins of mutton weighing t4llb. lost in roasting 49lb. I4o2« 
or 35| per cent. 

10 necks of mutton, weighing lOOlb. lost in roasting 33lb« 
60Z. or 32i per cent. 

It is therefore more oeconomical to boil than to roast meat ; but 
in whichever way it is dressed, there » lost from 1-5 th t« U3d of 
its weight* 

0&«^iT/z^tOfi«.—- Independent of the smaller loss of weight that 
takes place in the boiling of meat»' it must also be observed that 
the juices of the meat are also rendered edible in the broth fur* 
nished at the same time, by the addition of a few vegetables ; 
whereas in roasting meat, these are evaporated into the air ; it 
must however be confessed, that there is reason to believe the 
roasted meat is the most nutritive. . 



On the jifrt of Printing upon Stone. — Phil, J man* No. 1 Ig* 

It is necessary for the stone to have a close texture, to give a 
clean impression. The ink, which was considered a great secret, is 
inferior to coloured turpentine, copal, or lac varnish. Muriatic acid 
is preferable to the nitric, as it is not only cheaper, but also does 
npt act upqn the resin or wax that forms the varnish. 

In some specimens of marble there are veins that arc^ left un- 
dissolved by the acid. Some pieces of limestone from Clifton, 
near Bath, take a tolerable polish, and readily dissolve* 

The easiest method is that of Chauvron, on stone, or even lead. 

K wetting is not sufficient to prevent the ink from adhering to the. 

block, it may be sponged, and yet enough of the ink will adhere to 

. the figures* ■ 

. Observations.'-^An aceoufit of the origin 4tnd- progreis of this 

art may be seen at p. 138 of the present XQlume* 



( «»5 ) 
AGRICULTURE. 



Circumstances relative to Merino Sheep, cKiefiy collected frtm the 
Spanish Shepherds, who attended Flocks to this Country, By Sir 

' Joseph Banks, JT. B. — Communications to the Board of Agri- 
culture, vol. 6, part 2. , 

It is well known that the care of the king^s Spanish flocks has 
been entrusted to Sir Joseph Banks ; and this situation afforded 
him an opportunity of learning many circumstances relative to 
tiiA management of sheep in Spain, from the shepherds who came 
over with the PatUar flock presented to his majesty by the Spanish, 
junta of government. These circumstances are communicated to 
the Board of Ajgriculture in a letter addressed to Sir John Sinclair, 
the president, and form the article under consideration. 
. It is stated, that a considerable part of Estremadura, Leon, and 
the adjoining provinces, is appropriated to the use of the Spanish 
flocks, which are incorporated under the name of the ^' Mesta," 
and which are driven for pasturage from one part of the country 
to another ; and so careful is the police to guard them from inter- 
ruption, that no other travelling is allowed on the same roads, 
while the sheep are on their journey. The country on which they 
are depastured, in both their summer and winter stations, is sepa- 
rated into divisions, each capable of maintaining al^out a thousand 
sheep ; and every proprietor possesses as many pf tl^ese as will 
maintain his flock. la the winter and spring, the flocks remain 
in Estremadura, but at the approach of summer they travel to 
Leon for the sake of cooler and fresher pastures on the moun- 
tains ; and the shearing takes place during the journey : in Sep- 
tember tliey return. The flock of each proprietor is called a 
Cttvagna, and is separated into sub-divisions of one thousand sheep 
each, to which are allotted Ave shepherds and four dogs, who 
attend their respective divisions during the journey. And it ap- 
pears, that by the laws of the Mesta, the entire management of 
the sheep is confided to the care of the shepherds, -without admit- 
ting any interference on the part of the proprietor, to whom no 
profit accrues except what is derived from the wool, the carcasses 
of the cnlled sheep being consumed by the shepherds, and uq 
account rendered of the skin and tallow. The profit to the pro- 
prietor is estimated at from fi\e to ten per cent. And when the 
flock is increased to the greatest number the allotted space of 
ground will support, it is the business of the mayorel, or principal 
shepherd, to prevent any farther increase by killing the lambs m 

J^o. 26\— Vol. Yi, 2p 



i^6 Sir John Sinclaiic on Sicilian Wheat, if-c. 

aoon as they are brought forth ; and those preserved are made W 
suck of two or three ewes. The "change of pasttive is stated to 
have no influence upon the wool, but is resorted to merely for a 
supply of food. The wool of the dilpBrent iloCks differs much in 
fineness of pile; and the piles of Paular, Negrette, and Escurial^ 
which were reckoned the fhiest, were -withheld from exportation, 
^nd retained for the royal manufactory of Guads^laxara, ever 
since it was first established. ThcPUular flock consisted of 36,000 
sheep, and belonged to the Carthusian monastery of that name^ 
but was purchased by the Prince of the Peace soon after hi» 
advancement to power ; and when his property was confiscated, 
^came into the possession of the government. The number sent to 
the king was about 2000 ;,.which were selected by the shepherde 
fVom eight sXib-divisions, in order to choose young, well shaped, 
and fine-wooled animals ; and nearly one fourth of these died 
before their arrival at Kew. 

Sir Joseph Banks observes^ that though several of the eontineihi 
tal nations have imported Spanish sheep, yet none of them pos^ 
sess the complete and unmixed race of any one cavagna or flock; 
and that this circumstance was never regarded, till the king ob* 
tained from the court of Spain, in 1788, a little dock of 4 rams^ 
3o ewe^^ and a manso (or wedder), which had made a part of the 
Negrette flock ; and which have been kept unmixed with other 
breeds, by the special direction of his majestyr 
* The rest of the communication details the prices which the 
king's Spanish sheep have fetched at the annual auction, einee it» 
establishment in 1 804 ; and some eulogies on the national benefiti 
to be derived from the introduction of the Merino breed int» 
England » 

K 

Observatio7is.'— There is so little novelty in the ciretimstance^ 
respecting the sheep management of Spain, which are detailed in 
this article, that we are at a loss to conje<;ture how Sir Joseph 
Banks should deem them worthy of an q^d'o/eommunicfttioR to 
the president of the Board of Agriculture; though it is easy t» 
account for ikeit publication when' they had been' so ccmimHm^ 
cated ; for something must be given to the public by the- Board, in 
return for an aimyal parhamentary grant of 3000/. out o^ th€ 
Exchequer. 

On Sicilian Wheat, — Queries from Sir Jouir SiNCiAiifc, wUk Am^ 
^iwers by the Phince di CASTELCiCALiir — Commivmcetti^ns i^ 
the Board of Agriculture, vol* 6, part 2* 

^ The object of these queries appears to have been to ascertam 
what kinds of wheat were culti>:Ated in Sicily> 9fDd whether i^ 



Sir John Sinctiti^ on tie S]»ai^^$ Grain tilled Escanda. 96f < 

iRp<ptt)d bci possibU to pr€M:ure from thence a change of seed for the 
life of/Gre»t Britain* The Sicilian Bobli^^maD) to whom tho^ were, 
addre$9edy.sUU«9 that tbe pi*ocl.vi(C^.ot'hiciiy £» always suOi^efitly; 
abundant to allow of much exportation, though probably in a less 
degree than in the time of the Roman Empire. The wheals usually 
Cultivated are divided intoivhiteot *o/fU' heats, w^ich are generally 
sowed in light uplands, and into hard wheats, which are sown oil 
ail soils ; and three varieties of the former, and nine of the latter 
«rd particularly described. The white wheats are not thought to 
be wkH' adapted to the climate of England, though the red wheats 
may succeed very well ; the strong red wheat is supposed to b^ 
thesame which is cultivated in Flanders under the name oi Island 
wSSffT'TTie' only spring wheat cultivated in Sicily (there called 
Tumpnd) ,is j^ red grain and hard, and is sown in March, and th^ 
Jr6dtiCe is generally comiderable. The ports where ir heat and 
flour tnay be en>barfted itj Sicily, .and the prices in the money o{ 
the country, may be learned by a reference to the original article* 

Ohmrtatkmif^To tholgb who advocate the necessity of a changt 
<tf teed oorft, the enquin^ife bf Sir John Sinclair will appear impcnrti- 
ant and utriotic. m But wbethbr An advaatageeus thsm^ can be 
abtaioed from Sicilycao^niy be determined by actual experiments 
We eoUeet from the article that eome sved 6i eadi kind ot SiciliaAi 
%heas> was to bd seitt to the barant^t^ arid a future Volume of the 
]Mpen oithe bimrd«will> doubtless, coataiil an account ofrthi 
iiscciveriesof tlie ^iroftid^inthispai'tiottiar. . [ 



.1 

_ _ - _■ ^..^ _w_^ 



HivU regarding a Spanish Grain called Escanda. By Sir JoifSt 
, ^ Sinclair, Part, — Communicaiions to the Board of Aj^rkulture.^ 
vol, 6, part 2. 

Thi pr^idefifl of the Board of Agriculture obtained his inibrma^ 
lion respecting the existence of this grain from Admiral Apodaca; 
the picsent minister from the Spanish junta, who has promised ta 
iead ever a quantity of the seed. 

The Eseanda is considered peculiar to Asturias, and to be 
vnknown in other provinces; it grows to about the size of common 
wheat;'the ear is thick, long, and quite white ; the grains white and 
rather long, with a very downy point, growing in pairs ; it issowa 
in Deeembeff and is th« iast to ripea, and requires good land, or a 
rich calcareous soil, for it will not grow in places that are sandy. 
The ears are cut off from the stalky which is thrown away on 
account of its harshness; and some gathered it by hand. The 
grains are forced out of the ear with difficulty, sometimes by a mill, 
aind sometimes in a mortar, and are afterwards ground in a com" 
jDon mill into flpur, ai^d the bread is represented to be very whitfi| 

k V % 



i%9 On the Use of Barley jbr Hcnei^ 

dry, and pleasant, and very nourishing, but requires much labouf 
in the kn«.*ading on account of the small quantity of water put tSr 
it; thirty-two pints being sufficient for twobusheb of flour. 



Observations. — As far as we can forma judgment of £«c(iie(2a from 
the imperfect description of the Spanish admiral, it does not 
possess any valuable properties to recommend it to the notice of 
the British farmer;, and though it might perhaps succeed in the 
genialclimate of Devonshire, and in the Southern parts of Ireland^ 
it can never become an object of general culture. 



On the Use of Barley for Horses, Dravm, up by Order of th€ 
Board. — Communications to the Board of Agriculture^ vol. £• 
part 2. 

The practice of giving barley to horses is asserted to have been 
a very ancient practice ; and to prevail at the present day in 
£gypt, in Spain, and in Barbary ; and that the famous horses of 
Arabia have the same food. And the use of it in these countries 
is said not to have arisen from oats bdng unknown. Homes in 
Portugal are also soiled with green barley ; and throughout the 
^hole of Turkey, winter barley is their usual food. And common 
Imriey has been used in the county of Norfolk for the same pur- 
pose ; but this is generally steeped, and spread abroad for a few 
days. 

It is, however, to be remarked, that the barley which is used 
as food for horses in the southern countries of Europe, is not the 
Common spring barley usually cultivated in England, hntfaur or 
'six-rowed barky, which is cultivated in Scotland under the name 
of Bore or Bigg, all the kinds of which will stand the winter; but 
the full six-sided is stated to be the legitimate food for horses. It 
is asserted, that the partial cultivation of this kind of grain is 
solely to be attributed to prejudice, since it is well known that it 
produces more seeds than barley, and is less injurious to the 
ground, and may be sown on the same ground successively > with- 
out either lessening the produce, or impairing the quality, pror 
vided the land is fallowed before winter, and twice ploughed be- 
fore sowing, with a sprinkling of dung. Some Grecian barley 
had been sown by Sir John Sinclair, at Thurso, but the crop was 
inferior to Scotch bigg. 

The sowing of winter barley is strongly recommended, as not 
only proper for soiling horses, but as the sort besta^dapted to the 
spring food of sheep ; and it is added, that the being eaten off by 
sheep at spring* will not prevent a fair produce ; and that^ in oae 
e;Kperimenty it amounted to ireiie quarters per acre. . „. 



The course of husbandry recommended for the introduction of 
spring bartoy is, .1. turnips; 2. barley or oats; 3. clover; 4. 
wheat ; 5. winter tares; and then buck wheat to plough in for 
6. winter barley. 

Ohsej-vations. — ^The studied panegyric of a production, scarcely 
known to the south of the Tweed, sufficiently evinces the nativt 
country of the grain recommended; but the liberal Efiglishmm^ 
will not receive it with counter-prejudice. The winter barley 
forms a very valuable part of spring food for many purposes, and 
may be cultivated with much advantage in all situations where live 
stock are supported with difilculty at that season of the year. Of 
the merit of the corn as a substitute for oats, we are not so firmly 
persuaded as the right honourable president of the Board. 



as-' 



On nakedBarlei/. By Warren Hastings, Esq. — Cwnmurdcatwiu 
' to the Board of AgricutturCy vol. 6. part 2. 

This distinguished character writes to the president of the board 
Aat he has cul titrated naked tarley about twelve years r imvnig 
received the first seeds of it from Mr. Pacey, an eminent farmer ia 
Glocestershire^ under the nanfte of black barley; though;, from fla 
resemblance to wheat, he would rather have called 'it barley wheat; 
but he adopted the Qarno at the head of the communication out of 
deference to the Board of Agriculture. The original stock mm 
53 grains, which were sown in the fruit garden, and the first 
record of its produce was 10^ bushels in 1799$ which had increas* 
cd to 36 bushels in the following year, since which time it has been 
-sown instead of common barley. The quality of the gr^in it 
asserted not to have degenerated, but the assertion is made in 
1809, with a confidence something abated from that of the preced- 
<ingyear; and the only change of soil has been from the higher to 
the lower lands, and vice versa^ on the domain at Daylesford. It 
was sown at the same seasons with other barley, but no trial, to 
ascertain the relative quantity of produce has been made with any 
satisfactory result ; butin 1805 it was believed to be rather superioo. 
Th^ straw is said to be as good, if not better, for cattle, than that of 
common barley, and the weight of an equal measure to exceed in 
the proportion of 5 to 4; and as an exhausting plant it is not 
deemed worse than common barley ; and all the grasses arc found 
to Uirive well under it. Naked barley has not found a purchaser 
when offered in market, but Mr. Hastings cultivates it for the sole 
pui*pose of converting it into malt, for which he considers it parti- 
cularly adapted, as he has seldom ont graii^ to bt defactiva i|i 
Ycgetation at themi^lt-house* 



#96 " C^hhdMt^d m GredianbarTt^. 

The vrritcr concludes by expressing his decided eoniricti^ft of 
Ihc great utility And importance of the graitt, and declares his 
intentionof exteadingfais.culture of it beyond the quantity required 
for his own, that thesurplus may be for sale at the disposal of tbi 
Board, lie considers it to be the corn, which, next to rice, gives 
the greatest height of fiour per acre, and it may be eaten with no 
Other preparation than that of boiling, and requires little or no 
dr&ising at the miily having no husk^ and consequently producing 
IKi bran» 

ObstroatioM, — Attention is never withheld, when the call to 
teceiye information proceeds from Warrm Hastings. We wish, 
however, that he had favoured the public with the Lihnean defini* 
tion of the grain ^^ recommends to general .culture ; as naked 
barley is not sufficiently descriptive of the plant, though it ha> 
xvceH^ ihe authority of the Board of Agricuttuce* But when it 
is more widely cultivated, it will be better known, and we have 
jiohesitation in pronouncing that the desire of extending the culti-' 
vation of it will be bpyond the power of Mr. Hastings to supply 
the s^d. ' 



e«f9BS9»eBES9KesatBaaes«9sa9nfms9Hi^^ 



4^: GiTCMm Bdrlty. By ColovxI' MItfoiip* — C^nmumcati^tm 
: ' to ike Board qJ Agrkukure^ vot* 6. fart 2* 

V^nti circumstances commcmicated in this article were €oUectefl 
from conversations with Mr. Hawkins, who travelled with the )at« 
^Pmfessor Sibthorpe, during his last botanical researches in Greece 
and Turkey. 

^ It is 'Stated, that there are 4wo %at\» c( barley €«hivated in 
• Greece, the flat or two*rowed, our common spring barley;^ 
snd the six-rowed or round-^ared, which is the same as win* 
ter barley or bigg. Both kinds arc used for making bread, 
but the spring barley is preferred : the other is less produce 
five, though specifically heavitr^ The spring barley can only 
be cultivated on the high lands, but the winter barley 80stuA» 
ttll extremes of climate : the latter is the common horse-food, 
and esteemed the best, the former being reckoned to producii 
asthmatic and ricketty disorders; and during three weeks m 
March and April, the horses of the Levant are fed upon greea 
winter bariey. In Attica, the price of barley is half tliat of wheat, 
and the price of oats half that of barley ; one bushel of winter 
barley being reckoned as nourishing to a horse as two of oats. 
The weight of this barley to that of wheat is stated to be as IS 
to 25. 

Colonel Mitford made many attempts to raise Orecian barley 
iatbiscoantryfroA seed brought over by MnHawkins^ buttvm 



Cn the Use rf Sodp^dker$ Wmtt Jlthes as a Manmre. fft 

^ tevetitl yMivs obliji^d to gather it ia an unripe state or aecbunl 
<tf the extreme ^voracity with vrhkh it was devoured by birds, m 
0i>n9e«[uence of becoming ripe earlier than other grain. Afktm 
repeated trials^ he succeeded in obtaining .a crop of the six-rowcd 
Greeian barley, sowed in the same field with common barley^ 
The produce was, as nearly as could* be, the same as our nativit 
grain ; but he thinks 'it loses the power of ripening early, after i^ 
becomes accustomed to the climate by rep<;ated sowings* ' > 



-Iw. 



Obs€rv€ttiom, — It is to be regretted that this account was not 
furnished by Mr. Hawkins hiraselfj instead of being detailed ^X 
second-hand by Colonel Mi tford. It is, however, more accurate 
than could have been expected in an indirect communication : 
^d. as to the qualities of this winter barley as a food for horses, 
^e have the assertion of Colonel Mitford that he has given hisown^ 
horses the common spring barley for many years, without pKH 
ducing any injurious ejects. 



CMtJknae of 8<mfHimker£ Wms$9 A$kes^ commmly ctdiei 

Waste, as a Manure. Drsaxm. up bi^ order of the Board ifAgrif 
culture, and pubUsked by its direct ion^-^ommunicat ions to thtr 
SoardofAgriadinrttviL&^part^ - ■- 

. The^ Board having fovnd that the . produce cf doap-makeiV^ 
waste ashes amounted^ in London, and its immediate neigh* 
bourhood) to more than 20,000 tons per annum, and ', being 
convinced that this quantity of valuable manure w^ould be 
«a object' of coaiiderable importance to the national agncttitai^, 
if brought into more general use, were desirous of giving as muck' 
publicity as possible to their observations on the subject, it ia 
MmaiiEed, that the distinction to be found in soap^ashes dependa 
«pon the sort of alkaline salt used by the soap-boiler ; and that 
wh«a k^ and barilla are used, they are found to be twice ao. 
alrang at die peiuse of common pot-ash, and that from hence aristf 
Che tdbifietent reaultt obtained from the use of them In dtifereat 
pants of the kingdom. The soaper's waste of London is stated to 
cohsispl wholly o^ the le&se ei kelp and barilla, and yielded, whaii 
analized by Mr, Baty, 91 parts out of 100 o£ calcareovs maltter } 
and will consequently be advantageously applied wherever calca^ 
reous matter is wanted in lauds, and will serve the purposea of 
liming ; and the small quantity of alkaline salt and gypsum it 
contains will render it much superior to common calcareous mat* 
ter, as *a top dressing for every kind of grass. This waste haf 
been found to answer best of all manures on a peat moss, in strong 
<;^ldsoils; in Surry^ wh^ut it was applied in the q^uantity of tw» 



I I 



jt9S T, W. Coke J Esq, OK Experiments on long Dung. 

or three cart-loads to the acre ; and in Lancashive it was fotfnd ' 
Tery goo<l and durable on dry pastures : it has also been used with 
success in other parts, and the quantities applied have been as 
▼arious as those of other manures* It is generidly reckoned bettef 
fat pasture than arable, and crops of clover hay are said to have 
been doubled by it ; and is particularly calculated for mixing 
with various composts. The price varies in different parts, ac- 
cording to the demand, and the nature of the materials^ used ; as 
in Surry, about Is. a bushel ; in London, 5s. the cart-load ; ilnd 
in Glocestershire, 8s. the waggon-load ; and in Suffolk, where the 
soap-makers are farmers, th«y will never sell any. The effect 
produced by this manure is asserted to be admirable both on pas- 
ture and arable : it destroys slugs and vermin of every description. 
And the Board ofifer it as their opinion, that the farmers in the 
vicinity of soap-manufactories may avail themselves of these ashes 
as a manure without the smallest apprehension of loss, and with 
the fairest prospect of considerable benefit. 



Ohsetvations, — The recommendation of the Board for the use of 
diese ashes is founded on the soundest chemical principles ; and 
we have no doubt but that the experiments likely to be tried will 
be attended with the expected favourable result. 



Queries regarding Experiments with long Dmg, •with Answers. 
By T. W. Coke, Esq. M.F. — Communications to the Board of 
Agriculture^ vol. 6. part 2. 

Ik reply to the queries on this subject, Mr. Coke states, Uiat 
lie was induced to make experiments with long dung, by Miw 
Davy's lecture on the subject before the Board of Agriculture, in 
I80S ; that the dung was filled into the carts quite fresh, and the 
quantity from eight to ten loads per acre : it was laid on in th« 
beginning of June, and immediately spread and ploughed in, and 
the land sown with turnips, which entirely escaped die fly. Th« 
crop was better than had been produced in the same field for two 
and thirty years, though the manure laid on was not more than 
half the usual quantity. The profit could not be'ascertained be- 
fore the sheep fed on the turnips ivere sent to market.^ 



Observations, — ^The theoretical opinions in favour of long dung^ ' 
which have been too long slighted, are now borne out in practice 
beyond controversy, by this decisive trial of Mr* Coke, of 
I^olkhan^a 



( ^9^ ) 



fm 



BSfil 



m 



Wh Irrigation. By G. R. Eyres, Esq. of Lynford Hally Norfolk^ 
— Communications to the Board of Agriculturey vol. 6. part 2. 

•fhe writer states that he had justcompleated 23 acres of water 
meadow, nearly the whole cf which was in a very unproductive 
State ; part being a tough covert, part a moor oven-un with rushes, 
and thfe remainder gravelly, covered witH fern and bushes, except 
a poftioii of low meadow; From the natural situatioii of the land^ 
part of the water was disposed in catch work^ and the remainder 
formed ihto bods, tht? turf being in the first instance pared eff by 
the breast plough, and laid in again as soon as the beds werd 
formed* As immediate produce was ndt the object in view, little 
attention was paid to that for the first season, the owner consider* 
ing winter waterings for the purpose of procuring early spring feed^ 
to be the grand object of irrigation* ^ The expence was about six-* 
teeii guineas per acre, exclusive of masonry knd carpenter's work 
for the drains, which amounted to about two guineas per acre 
liiore. 'there was a fair promise of a luxuriant crop the 9econ4 
sei^h, lUid the result is to be communicated lo the Board. 

Observdtioia, — ^Thei^ is nothing either of novelty or information 
In this article, biitthe writei' was rewarded with the gold medal 
by the Boatd for introducing irrigation into a part of the country 
where it was wholly unknown. 



On the Maple Tree», By James Hall« Esq* — Commumcatians to 
tke Bomtl of Agriculture^ vol. 6. part 2. 

' Tttfc writer, expressing his stirprize that the cliltivatioa of the 
sugar maple should be so little attended to in the Highlands of 
Scotland, remarks, that it thrives well in many parts of America^ 
where the winters are as cold, and the soil not better \ and that 
it succeeds in hedge-rows in all exposures, and may be propa- 
gated either by seed or slips. But though its growth is rapid, it 
IS twenty yeafs arriving at maturity ; yet, before it is half that 
age, very considerable quantities of juice may be obtained from 
it by boring a hole in the tree, into which a spout is inserted, 
with something placed underneath to receive the juice, which 
may be collected every night ; when it should be strained and 
• boiled in order to produce sugar. The juice of the maplo is said 
to flow four or five weeks annually, and an ordinary tree to pro- 
duce about 20lb. of sugar ; and to afford also a most agreeable 
molasses, and an excellent vmes^ar; the juice hein^ fit for these 
purposes, after it ceases to be so for sugar. It is asserted that tlit 
No. 25.— Vol. vi. 2 q 



29^ Hall m the odxantagH of Heath in feeding of Stock; 

tree is not injurrcl by tapf ^ng ; mmI that tbe leaves are very nutr]« 
tioiis food tor cattle, ou account of the saccharine matter they 
contain. 



aapMsakMN«iW« 



Obietxatians^ — While sugar can be procured with the 6ame faci* 
lity as at present from our West India colonies, it is scarcely 
worth the trouble of cultivating it at home ; should, however^ 
circtimstanccs hitherto unforeseen and unexpected, occur to prc- 
friude a supply from the colonies, then the maple may be advan* 
lag<^usly resorted to as a complete substitute for a foreign pro- 
duce> which is now come into such general use, as to be almost 
reckoned among the necessaries of life. 



riUh 



On the advantages to he derived from Heath in the feeding of Stock, 
JSy James Hall, Esq. — Ccfmnmmcations to the Board of Agr^ 
culture^ vol, 6\ pdit Q» 

In the course of many experiments on furze, broom, rushcsi 
b<'an straw, and other neglected articles, Mr. Hall had disco^ 
vered, that if heath be cut when young and in bloom, and the 
finer parts infused in a tea-pot, it produces a liquid very grateful 
to the taste, well flavoured, and extremely wholesome. And 
being anxious to know how far young heath might be useful t9 
cattle j he tried the experiment on a cow. When first tied up, 
she refused to eat any of the heath, except the very finest part, 
nor did she appear to relish an infusion of it aet bel»ra ber ; b«w« 
ever, hunger induced her first to drink the infusion, and then to 
>eat the heath, and she lived nearly a fortnight on that £Md 6n\y,i 
her milk was much reduced in quantity, but was imfutoved in 
quality; A similar experiment was made on a couple of sheep 
and an old hoi'se, with Jiearly the same efifect. 

Being satisfied from these experiments, thfit cattle may be sup^ 
ported 4br a long time by young heath, Mr. Hall proceeded tp 
ascertain how iiiar the plant was capable of retaining its valuable 
qualities, when dried and laid up. He Therefore cut some at the 
end of summer, and dried it in the shade ; and at the end of two 
years it produced an infusjon equally strong and well flavoured as 
at first ; and the effect was the same at the end of three years. 

It is stated, that if heath be cut when in bloom, and boili^tf 
water-poured on it in a tub, there is produced an infusion, not 
only rich and pleasant, but capable of being made the basis of 
various vajuable liquors ; and that any quantity of young heatk 
ftiay be procured by turning the old, which remains on tbe 
ground ; and the ashes afford an excellent manure, and generally 
cause a fine young crop to spring. up : this may also be cut for 
hay at two or three years old, ^nd may be given to cattle wbea 



Horses and Oxen eomparedy by the Rev. R. KedLngtom,^ 295 

fodder is sciarce ; but when intended for this purpose, it should 
fee carefolly stacked and kept close, otherwise it wiU become less 
Yaluafale. , ^ ' 



OA««T<7^/o;w.-*-Thc certainty that heath maybe relied oi* ad A 
food far cattle is valuable information in many districts, where 
winter food is with difficulty procured. It apj^ars, howcverL 
thai the most ad\'atttagcous mode of using hay made from thii 
plant, would be to give it c^X into chaff, and mixed up with 
other more palatable substances ; for, as Mr. Hall did not pusll 
bis experiment of keeping a cow solely upon heath longer than a 
fortnight, it may be inferred, that had the trial been longer perse*- 
ver«d in, it would have been less successftll. The circumstance 
of heath improving the quality of milk seems an argument forgive 
iug it to cows at the same time with other foodie which would 
prevent a diminution of the quantity. 



B^ses and Owat cmpartd. By the firv. R, Keoinoton^ qf 
Ranghtttn^ near Bury^ Ssi^QlkJ-^Qmw»mcutiQm. to ike Bmrd ^ 
~ Agrlemkwe^ vW. 6. fari % t 

Thts' gentleman first determined to employ oxen ftt the yeat 
1778, but was two years before he could conquer the repugnance 
of his workmen : he persevered and stjcceedccT, One pair of oxen 
was allotted to a farm of 27^cres of light arable land, ^nd 40 
acres of pasture ; and two pair upon another farm of 80 acres o^ 
stronger arable, and 14 acres pasture ; but the oxen of the two 
farms sonaetimes assisted each other, and in this manner performed 
all the work and highway duty for four years, ^he oxen wer^ 
hsniiFilsed with bits in their mouths, and driven in the sam« man- 
ner as horses, and in waggonsund carts went single. Not moi« 
than two were used at any time in a common single plou^ la 
consequence of taking into hand a very extensive farm in 1784| 
Mf, Kedington then used boti^ oxen and horses, and found th^ 
hovses to do quite as much work as the oxen ; bat was obliged in 
a few yearsto part with his oxen, because the ^en food be could 
raise was not more than sufiicient for his sheep ; and he could not 
reconcile himself to diminish the number of his sheep, In 1801, 
Be again reduced the land in his own occupancy to about 90 
aeie» of arable, 70 of pasture, and ^7 of wood ^nd plantations ; 
and he kept four horses, with the intention of gradually exchang- 
ing; them for oxen ; but as few are roared in Suffolk, and thosf 
chiefly by farmers for their own use, he turned his attention to 
bullsy and purchased two of thfce years of age, which had never 
been worked. These he broke in oy first making them .walk till 
they tvcre somewhat tired, a^d then, by the geiitlesl means, thcj^ 

2 Q 2 ' 



296 Sir Joseph Banks* s iMemoir on Seed Grain* 

were harnessed and bridled, with bits in their mouths ; and ^ 
piece of tiiuber, ten or twelve le.»t long, with a strong staple at 
one end, was placed in a field, and the bull fastened to it by very 
long traces, to prevent the log from hurting him ; and two men 
are placed on the sides, with a line fastened to the bit, to prevent 
the bull from turning ; and when he goes tolerably quiet, ahorse 
>s placed before liira, and they draw the load jointly. Thispror 
f;ess, with patience and good usage, was found to be successful ii; 
^U cases, even with animals previously vicious ; and it is asserted, 
that bulls may be broke in to work with as little, if not less trou- 
ble, than coits. This writer is so convinced of the utility of bulb 
Sot work, that he has used them constantly since 1801, and pre? 
fers them to oxen ; and has no hesitation, upon a comparispn ii^ 
pyery poipt of vieyv, that they are to be preferred to horses. He 
concludes by declaring, that jie would i^pt exchange his four bulb 
for "the four best cart-horses in the kingdom. 

Observations, — ^The long experience of Mr. Kedington enables 
bira to give a decided opinion on the comparative merits of horses 
and oxen on light soils, like Suffolk ; but we conceive, an attempt 
te extend his practice to deep soils would only end in disappoint- 
ment ; and we cannot admit of a pxeferei^ce to bvills oy^r oxen. 

0;t Qjsen, jBy Da v;d Barclay, Esq. — Communications to th^ 

Board qf Agriculture^ vol. 6. part 2. 
On Horses and Oxen compared. By Mr^ WhitwQRTH. — Commut 
. nicaiions to the Board of Agriculture^ vol, 6. part 2. 

Thssb two papers arc so similar in their design, that they may, 
with much propriety, be noticed together. The conclusions in both 
are in favour of oxen ; in the former the inferences are the result of 
experience^ in the latter the deductions of just reasoning. In 
Essex, where Mr, Barclay lives, the soil is light,and does not require 
vast powers to turn the furrow. And we cannot again forbear to 
inculcate that the nature of the sqil should form a chief part of the 
consideration whether oxen may be substituted for horses with 
advantage upor the whole. 



Memoir on Seed Grain. By Sir Joseph Banks, K. B. — Cotfwwu- 
nicaiions to the Board of Agriculture, vol. 6. part 2. 

It is the opinion of this learned writer, that the attention of tlie 
Board cannot be more adyantagcJusIy employed for the public, thai^ 
jo discussing the question whether the corn and pube which is lc9^ 



RiT Joseph Banh^s Memoir on Seed Grain* 2j7 

and small in size, and consequently separated trom the rest as not 
marketable, be not quite as proper for seed, and as fully endowed 
"with the properties of the. parent corn, and as likely to produce a. 
superior sample, as the heavy and plump grains. 

Sir Joseph contends (and we think unnecesarily, because theposi* 
tion will not admit of being controverted) that much of the pro.Iuce ' 
Qf the soil now condemned as refuse, being employ<*dfor sced,woul(l 
leave a larger portion of the best corn for animal consumption^ 
** If, says he, we admit the increase usually derived from the culti- 
vation of wheat to be fourteen times the amount of the seed sown, 
we must also agree that one fourteenth part of the very choicest of 
the produce of every good harvest is annually committed to the 
earth ; and inyears of dearth, when speculators increase the breadth 
of their wheat crop, a still larger proportion ; should experiment de- 
cide that we may safdly substitute in the place of this valuable ar* 
tide, the small grains which arc generally destined to the rearing 
of poultry, the gain of the public will be immense, and the loss 
scarcely sensible." And having stated thus much of the theory, 
he proceeds to give an example, and states that in the year 1807, 
which was a most calamitous season for peas, the Earl of Winchel- 
sea had a peck and a half of shrivelled and unsaleable pulse, (the 
refuse of the crop of nine bushels) which in the following spring 
Ijie ordered to be dibbled into as much land as they would cover, 
which was compleated in April, and the work measured six acres 
and thirteen perches ; the crop reaped was 25 J quarters of good 
boiling peas, weighing 18 stone 7lb. to the sack. The advantages 
which would result to the community if this plan became univer- 
sal are then pointed out, and the opinions of Sir John Sinclair in 
his publication on the blight, &c. are brought into review. It is 
stated in that publication, on the authority of an intelligent farmer, 
who had sowed both plump and lean seed, that from their first 
appearance, the corn from the plump seed was much more luxuri- 
ant, and it continued so, as if it had been dunged, and the other 
neglected ; but no account is piven of how long the superiority con« 
tinued ; and asserts, that well filled seeds are better calculated tor 
pushing in search of nutriment, than grain of a meaner quality. 
The reply to this argument is, that a rank and luxuriant crop is 
more likely to run to straw than to grain, and is very frequently 
deficient in produce. 

ObsercatioJis.-^There is certainly some ingenuity in the sugges- 
tion of Sir Joseph Banks ; but that thin and lean grains should 
produce an equally healthful progeny, with the best samples, is 
contrary to the analogy of all other departments of nature. And 
we cannot conceive such a distinction between animals and vege- 
tables, that what is allowed to be inapplicable in the one ciin b^ 

tablished in the otljer, 



,.. ( 29* ) 

\ 

Comparative experiments on the cuHure and appUcaiioH of Kohl* 
rilfij Drum-headed Cabbage^ and Sicedish Turnips. Bjf Mr. 
John Saddlngton, of Fuichley. — Trana.Soc. ofArts, toL 27* 

Tu E land appropriated to these experiments was about two acres 
tnd a hall, which had been previously underd rained; the soil was 
a loam^ with chiy and gravel undfT. In March I8O6, oats were 
sown upon it. at the rate of three buohcls and a half to the acre, 
and the produce was nearly five quarters per acre. Winter tares 
were next sown, which were eaten off by sheep, and a crop of 
■wheat was then taken. The crop being housed, and the stubble 
mowed and cleared off, the land was got ready for turnips m the 
la^t week of August, and three pounds of seed wt re sown upon an 
acre ; and when the plants were just making their appearance, 
two quarters of gypsum were sown by band, to pn venl the fly. 
The crop of turnips proving very valuable, led to the experiment 
T^hich is the subject of the communication. The preference is' 
^ven to kohl rabi over drum-headed cabbage and Swedish turnips, 
beiog found a prolific plant, and nutritious for the feed both of 
slieep and neat cattle, and producing green food from October to 
May. In order, however, to insure a succession of keep, seed 
should be sown in March, April, and May. Th^ plant is de- 
scribed as butting above the ground, with a leaf not unlike beet; 
and It is found td^ stand the severest frosts, even when incisions 
ace made with a knife two or three inches deep. The plants may 
be transplanted the same as cabbage ; and when transplanted at 
eighteen incW asunder, have weighed ten or eleven pound* 
each. 

The mode of culture adopted by Mr. Saddington, for this expe- 
riment, was, to sow kohl rabi seed on the 14th of May, and the 
plants were transplante<l, at twelve inches apart each way, on the 
18th of June ; and averaging the plants at three pounds each, the 

troduce was upwards offiftjf-eight tons per acre. ^In March he 
ad also sown some drum-headed cabbage seed, and the plantft 
'were transplanted the second week in June, upon ridges three 
feet asunder, upon land previously dunged, and the produce was 
not twaity^ix tons"per acre. . The cabbages were much damaged 
by. the caterpillar, which did not touch the kohl rabi on the ad-^ 
joining lands. In June Swedibh turnips were sown, but two thirds 
oi the crop were destroyed by the fly : the Swedish turnips were 
not equal in Wieight to the kohl rabi in any comparison. Beside* 
this superiority in weight, a decided preference is given to the 
kohJ rabi, because there is less waste in eating it upon the ground^ 
inasmuch as it bu|bs above the soil, while the Swedish turnin 






JRrtJ. /* HaM on a Prtjxtrtititnfr^n'BemhStalh for Smp. 559 

btilbs in it^ and "when eattm lovel with the ground, becomes a 
receptacle lor diit, and coi»eqacntiy no longer regarded tfs 
food. ' 



Ofeen'^/on#.— The public are much obliged to Mr. Saddingtoti 
lor recommending the cultivation of so very useful a plant as the 
kohl rabi, by an exprriment so decisireJy conclusive. We havfe 
little hesitation in saying, that when once tried ona farm^ it Wift 
never be-again abandoned, unless circumstances precllide its cuK- 
• tore. The unassuming style of the communication affords, tea, 
« favourable impression of the writer* 

• tWWWMWTj.i i ,j J i i i i i 'i gggaeggBaaeBBagneg^gBigBaagB^^ 

■ 

On a preparation from Bean*9iM0f bb a substitute for Hemp. By 
the Heo* James Hau, rf fFaitkmmtoWf Esse9^ — ZV«w. Soci 
ifArts^ *DoL^7* 

The communication ob this subject statn, that ei^efy hetih 

plant contains from 20 to 35 filaments or fibres, running up on 

the outside, under a thick membrane, from the root to tbe yrttf 

top all round, the one at each of the four corners being rather 

thicker and stronger than the rest ; and that, with the exception 

of the Chinese sea-grass, used at the end of fishing-Klines, these 

lilanients of the bean plant are among the strongest yet discovered; 

and are easily separated from the strawy part, with a little beat«_ 

ing^ rubbing, and shaking, when the plant has been steeped teil 

or twelve days in wafer, or is damp, and in a state approiiching ih 

fermentation ; and, as far as the writer has discovered; washing 

and pulling it through hackles or iron combs, first coarse, and 

then fine, is the easiest way of dressing bean-hemp. A calcul»- 

lion is given, from which it appears, that about two hundred 

weight of'this hemp may be obtained from an acre of beans ; and 

the fibre is thought to be admirably calculated for being con^ 

verted into a thousand articles, where strength and durability t% 

of importance ; as well as, with a little preparation, into paper 

of all kinds. 

In order to ascertain in what degree this species of hemp H 
liable to injury from different situations, and the changes of th^ 
jjttmosphere, Mr. Hall exposed one parcel nearly twelve months ' 
€# all the varieties of the air within doors, and kept another paN 
<!fel constantly under water for the same time j and neither of thesfe 
was fotind to be injured in the least: the chief diflfetencc waai^ 
that the parcel kept under water became the whitest of the twof, 
9Li\d assumed a rich silky gloss, df which the other \was dfestitutt?. 
Jt ie also stated, that it bean-straiy be kept for years under water, 
or quite dry, it produces hemp as good and fircsh as at firbt ; but 
if the straw be sometimes wet, and sometimes dry, tfae'filttmett& 



(500 tf^. Congi^ecty iRsq, on planting OatcSi 

ere apt to be injured. If the straw was scattered tliiri on tt* 
ground, and exposed to the weather for two or three months, it 
was uniformly found that the hemp or fibres are loosened, and 
easily separated from the strawy part without any other process 
than merely beating, rubbing, and shaking them ; but from the 
fermentation that takes place in the strawy part communicating 
itself' to the hemp, it was more or less injuredj but never so muqh 
tis to render it unfit for making paper. The water in which bean* 
straw was steeped, acquired in a few days a blackish colour, but 
cattle drank it greedily, and seemed fattened by it. When straw 
is to be preserved for bean hemp, it is considered proper that the 
beans should be threshed in a mill, and be put into the rollers of 
the mill length-ways, and not across the rollers ; otherwise the 
straw will be very much cut, and the fibres damaged. 

Obseroatiims. — Before we can sanction the discovery of Mr. 
Hall by our recommendation for applying bean-straw to the use 
he points out, it is necessary that the filaments prepared from it 
should be manufactured into various of the articles for which 
hemp is now used. 

On planting Oaks. By W» CoNGUfevE, Esq. of Aldermarston House f 
in Berkshire. — Trans. Soc. of Arts, vol. 27- 

This successful candidate for the gold medal of theSociety states, 
that since the year 1 802 he has planted more than 74- acres in and 
near his park at Aldermarstonwith young oaks; the first plantation 
of which, being twelve acres, made in 1802, arc from six to eight 
feet high; and most of those planted in 1807, about one foot high. 
The whole of the plants are said to be well fenced, and that there i 
are more than three hundred plants upon every acre of ground. 
The acorns were set by women and children with sticks used in bean 
setting, about two inches deep, in rows a yard asunder, and a foot 
between each acorn. Except in the first plantation the land was 
not prepared in any way whatever: where there was* furze and 
heath, the furze was cut down as close as possible, but the heath 
was left as a shelter to the young plants. It was conceived that 
the heat of the sun was very injurious to young plants, and that 
heath or long grass was a great protection to them. In that plan- 
tation which was cultivated, the land had been ploughed two or 
three times, and about a month after the acorns were set, it was 
town with furze seeds> broadcast and harrowed : the furze became 
luxuriant and was cut for fuel, but gave such a' shelter to rabbits, 
that they proved destructive to the young trees, and w^as conse- 
quently obliged to be destroyed: The soil on which all these plan- 
tations are made, is a mixture of gravel and clay, andiu a few places' 



J 



Account of Land gahied from the Sea. 501 

almost entirely clay ; about eighteen acres were heath land^ to- 
tally uncultivated and unproductive. 

Observations, — ^Thesc very extensive plantations of oak well 
merited, the reward of the medal, which they obt-ained. Mr. 
Congreve's agricultural improvements in other respects, as welfas 
in his plantations of oak, need only lo be seen to be duly appre- 
ciated by every one who is a competent judge of the benefits 
which a country gentlenijan can in this way confer upon the 
public. 



Statement of drilled and broad-cast Husbandry, By Messrs. 
Batchelor, of IddlingtoUy — Agricultural Magaxiney No. S6: 

The experiment was made in 1808, on a sandy soil, pn part 
of a field pf 16 acres and a half, after turnips fed off by sheep : of 
this about 10 acres was taken for the trial, and was sown with 
oarley. The drilled barley occupied 5 a. Or. 34r. of ground, and 
had 17 J bushels of seed sown thereon; the broad-past occupied 
6a. 3r, 6p. and had 22 J bushels sown thereon : the drilled crop 
was horse-hoed, and the broad-cast weeded by hand ; and the 
eiqjence of labour on the drilled crop exceeded that of the broad- 
cast by 5s. 8d. an apre, The total produce of the drilled crop was 
27f\vs. 4 bushs. 3 pks. or about 5(ir«. 2 j bushels per acre ; and the 
produce of the broad-cast crop was 26qrs. 3 pecks, or about 
4qrs^ 44 bushels per acre ; th superiority of the drilled barley 
was, therefore, above 6 bushels pi r acre. The time of drilling 
and sowing was the^Slh and 29th March : very little difR:rencc 
was observed, in either crop, during the growth. In the corn 
produced tiiere was not the slightest diftcrence of quality. 

Ob^rvations, — ^This experiment gives a result decidedly in 
favour of the drill husbandry; but it should be recollected, that 
the trial was made on a very light and sandy soil ; and perhaps a 
result equally favourable might hot have beci> obtaiijed on a soil 
of a ditferent nature. 



jiccount of Land gained from the Sea, By Mr, W, LAttRENCE. 

— Agricultural Magazine, No. 36. 

The lands reclaimed from the sea by this writer are about 100 
ncres, and arc situated in Essex, near Maiden. The embank- 
UK-nt is made of spil only, not thrown loosely together, but cor^- 
posed of the earth which was tiiken frotn a ditch on th« land sid* 

fno. 25. — Vol. vi^ ? R 



/ • 



502 On the management of Cattle in the Highlands of Scotland. 

the embankment, and from the sweard and soil taken from off 
the foreland on the sea-side. The earth was thrown together to 
form the wall or embankment, and after every layer, well rammed 
together by the workmen ; and in this manner made so firm and 
consistent, as not to have sunk perceptibly, though several high 
tides have happened since its completion. No gtass seeds were 
sown on the bank when it was first made, because, being so much 
impregnated with salt, it was thought they would be burnt up 
on the bank by the heat of the summer ; but grass seeds will be 
sown at the end of a year, which are expected to produce ttiuch 
good sheep food. 

Observations, — We record with satisfaction, another instance of 
much valuable land being reclaimed from the sea, to the advan- 
tage of the community ; ^nd, we trust, also, to that of the indi- 
vidual who has conducted the undertaking. 



mamesm 



\ 



On the management of Cattle in the Highlands of Scotland.—^ 

y Agricultural Magazine^ No. 37. 

The cows are said to generally produce their first calf at the 
age of four years ; and while the price of cattle was low, it was 
the practice to kill half the number of calves, and to allow one 
calf to suck two cows ; by which means the calves were well 
reared, the cows were kept in better condition, and the surplus 
milk compensated the loss of a calf; a portion being withdrawn 
for butter, and the calf then allowed to take the rest ; but since 
cattle have become more valuable, the system of coupling has 
been given up. The cows calve from the middle of March to the 
middle of June, but the early calves are always esteemed the best. 
In the beginning of November they are deprived of milk, and the 
cows sent to winter pasture \ the calves are put upon fine pasture 
at the same time, where they Remain till the fall of snow, when 
they are housed, and fed till May with oat-straw, hay, potatoes, 
and turnips. For the firet year, the young cattle are generally 
fed on the high grounds, and are afterwards removed to the low 
grounds. From three to five years old, their freight, when lean, 
may be averaged at 70 or 8Q lbs. per quarter, and their price from 
four to seven poitnds. 

Observations. — ^This anonymous account of the mai^ageiiiieQt of 
cattle in the Highlands of Scotland, has been obviously manafac- 
tured from publications to which no reference is made ; though 
it can convoy no information to the Scotchman, it may amu^c the 
reader on the South of the Tweed. 



( 505 ) 



Ott the mode of preparing French Vinegar, and the different specter 
of the article which are manafactured in Trance, — Agricultural 
Magazine, No, 38. 

It is remarked, that although the word Vinegar implies, that 
this acid liquor is usually extracted from wine, yet it is obtained 
from divers other materials ; and even from some in which one 
would not at first suppose there existed any principles capable of 
forming an acid comparable to wine vinegar : it is manufactured 
from perry, cider, beer, mead, milk, and even from grain and 
vegetables. And though good wine is necessary for the produc- 
tion of good vinegar, yet the French most commonly manufacture 
their vinegar from their unsaleable wines. Tlie processes pursued 
in this manufacture are said to be various ; but the general plan 
is, to expose the wine to the contact of the air, and to a heat of 
between 20 and 22 degrees of Reaumur's thermometer,' in tuns 
not entirely filled, and fermented with vine-branches, grapes, 
gooseberries, the lees of sour wine, &c, &c. which materials are 
styled by the makers mother of vinegar. And in order to conceal 
the weakness of the quality, and to improve the acid flavour, 
there is frequently added Indian pepper, and other highly bitter 
drugs, which communicate nothing of acidity, but merely give 
it an ardent flavour. 

The best mode of ascertaining the quality of different vinegars, 
is said to be saturating them with potash : an ounce of genuine 
vinegar being saturated with sixty grains of potash, while the 
same quantity of vinegar, sophisticated with bitter substances, 
only requires twenty-four grains for saturation. And the adulte- 
ration of viaegar with oil of vitriol is said to be more easily disco- 
vejred, since the odour of this 9,cid is immediately perceived, by 
casting the vinegar that contains it upon burning coals. It is 
fi«lded, that several nations, in default of wine, employ divers 
other articles in the manufacture of vinegar, but that liquor of 
this description ought rather to be called alegar than vinegar. 



Ohcrvations, — This poor, unsatisfactory article, is the only 
one we could select from this number of the Magazine, possessing 
any claim to origii\ality ; and what claim of this kind it may 
have, the writer has not the courage to avow his right to it by 
giving his name. The matter it contains is not new to us, though 
y^e cannot imraeiji^tely point out the source from whence it is 
derived* 



2 R 2 



( 304 ) 



Draft and description of a Threshing Mill latelji invented, ffj 

\V. B. — Farmers Masazine. No. 4^. 

This mill is stated to be the invention of a Mr. Monteith, at 
Skirramuir, near Dumblane, in Perthshire. It is almost imposr 
sible to give an intelligible account of this machine, without the 
assistance of the drawing which accompanies the description. The 
principle is, to thresh the corn in a circular box, similar to the 
box which incloses the stone* of a mill for grinding, into which 
the corn is introduced by the hand, through holes in the top of the 
box ; and the threshing is performed by the revolution of four 
radii or spokes, projecting at equal distances from a vertical shaft, 
which passes through the centre of the box, and may be turned by 
water, or by horse machinery. The corn passes through the bot- 
tom of the box, which is formed of wooden ribs, not an inch 
asunder; and the straw is rejected through a hole in the side, by 
the centrifugal motion. The particular machine described is 
turned by water falling through a trough upon boards placed at 
the bottom oCthe shaft, so as to communicate a rotary motion; 
and the effect is' described by the number of sheaves threshed in a 
minute, which is too arbitrary to convey any idea of precision. 

Observations* — Without intending to derogate from the inge- 
nuity of this invention, we agree with the conductor of the Maga- 
zine, in entertaining strong doubts of its utility. If water be used, 
it may be applied more economically ; and it is obvious, that the 
labour must be increased from the want of feeding rollers, and 
that the straw will be, in a manner, beaten to chaff. 



Thoughts on the periods of sowing Seeds of different Kinds. Bjf 

A. M. — Farmers Magazine^ No* 42. 

As it is admitted, that the duly adjusting the periods of sowing 
seeds for different kinds of crops according to the forwardness of 
the season, is of great importance in agriculture, and as the tem- 
perature is far from being the same in different seasons at the sara<J 
period of the year, the writer infers that the seed time ought to 
vary with the season, instead of being confined to any particular 
period ; and he thinks that the best standard for determining the 
most advantageous period is, the budding and leafing of ti*ees. 
The budding and leating of the birqh tree, is said to be considered 
in Sweden as a directory for sowing barley ; and it is'recorded in 
4hc Amonitates academico that the illustrious Linnaeus exhorted hi» 



On the vmpraprieiy of mixing the Seeis of Grasses^ S^c. 30* 

Cotintrymcn to observe ^ith care what time each tree expanfls it«_ 
buds, as infoiTfiation which might lead to the most useful purpose'*. 
For these reasons the prudent husbandman is advised to watch 
the budding of trees, and to collect from this circumstance the 
proper time for sowing, and to make the operations of nature a 
calendar for his own labours; and it is contended that more 
favourable crops, than would otherwise be obtained, will amply 
rew^ard his diliscnce. , 



Observations, — ^There can be no doubt but that nature is our 
safest guide in all labours of agriculture ; and the sugsjestions 
thrown out in this paper for fixing the time of sowing different 
seeds may certainly beobtained by observations cohtinuctl through 
a series of years. The analogy between the budding of trees and 
vegetation of seeds is striking, and we recommend the hint here 
given to the attentive consideration of farmers in general. 



Cheap plan of <i Sheep House, By A. S. — Farmer^ s Magazine'^ 

No. ^2. 

• The sheep house recommended in this paper on account of its 
comparative cheapness is 85 feet long by 15 wide within the walls, 
which are only about three feethigh, of plain rubble work of stom% 
with lime mortar. The doors are at each end, sufficiently high 
Sot a man to carry in a burden of hay. It is thatched in the 
common way, and at each end a circular piece is inclosed by a 
wall, six feet high, to preveht the storms from blowing in at tha 
doors. The cost of such a building is given at 251. 

Observations,: — ^The utility of such a building for sheep in bad 
weather is self-evident, particularly in bleak situations; but there 
are few parts of England (if any) where a sheep-house of this size 
can be constructed under double the estimated expcnce. 



" On the improprieti^ of mixing the Seeds of Grasses, when Land is 
soxon down for Pasturage, By Mr. James Head rick. — 
Fanner's Magazine^ No, 42. 

The contents of this paper are given as the mere ebullitions of 
agriciiltural conversation ; which, however, were deemed worthy 
by Mr. Headrick of being submitted to public notice. It was in- 
sisted, that in laying down land for permanent pasture, so as to 
derive the greatest possible profit from it, all mixture of grasses 
should be avoided ; that the land being sufficiently cleaned* and 
aJiurcd, one field should be fully stocked with white clover ; an«« 



Se6 On the Disease in Cattle catted the Stack SpaW 

ther with perennial rye-graws; another with rib-grass ; another witH 
wild vetches ; and thus each field should be occupied with plant? 
of a different species ; and that the stock should be frequently 
shifted from field to field ; which would m^ke them eat with ^ 
keener appetite, and fatten more rapidly, than when presente4 
with a mixture of grasses, which are never changed : for it may 
be observed, that plants of different species do not thrive so well 
'when mixed in the same field, as when they grow^parately; ^n4 
that, when animals arc put into a field containing a great number 
of plants, there are always some which they prefer, and select in 
preference to others, while those that are n\jccted are trampled 
down and lost : but in the plan proposed therp is no rqpm <bf 
selectipn ; and by the regular change of the species of food, the 
natural appetite for variety receives complete gratification. 

— — ^— M— ■ ^lih 

Obsenations* — We have deviated from our prescribed rules, not 
to notice mere opinions^ unconnected with experiments, because 
we consider the present article furnishes some very useful hints on 
an important subject, which i^ at present but imperfectly under- 
stood. 



On the Disease iu Cattle called the Black Spald. By W. F*— 

Fafvner's Magazine, No. 42. ' 

TiiB black spaldy which is also sometimes called the quarter ill, 
is a disease which very generally proves fatal to cattle ; and no 
certain remedy has yet been discovered for it. It is supposed to 
be occasioned by the accumulation of air underneath the skin, 
which makes a progress from the extremities towards the heart, 
and terminates in death, unless this progress be' arrested. A me- 
thod of cutting the skin, to let the diseased air escape, was recom- 
me.nded in a former volume of the Magazine, and is said to have 
been successfully applied in some cases ; but the writer of this 
article states, that he consi,ders the remedy so precarious, that he 
had recourse to two modes of prevention ; the first, to let blood 
from his young cattle in the autumn, which is considered benefir 
cial at least; and the other, putting a layor of tar acrpss the 

. back, immediately behind the ribs. This method h^.d l^n prac- 
tised with success by Mr. Christison, of Cumbernauld Ho.use ; 

• but two young cattle, which had been neglected, fell victims ta 
the disease. 



Observations, — ^The success of the application of tar as a pre^ 
iFcntive of this fatal disease, does not appear to b« established 
by sufficient experiment to be implicitly relied on ; fpr it is imp<f* 



Obsertattons on faying do-wn Mead&w and Pasture Land, SfC. 30J[ 

sible to say, whetiier the young cattle which were subjected td 
the application, might not have escaped, the disease without it. 
It may, however, deserve consideration, whether a blister appli*^d 
between the diseased part and the heart, might not arrest th« 
progress of the disease. 



Observations on the use^ ofldme. By O — r — s. — Farmer^ s.MagOr 

zincy No. 43. 

The writer, being engaged in the improvement of a farm, iMxtir 
Ittcr-fallowed a park of ten acres, which was considered the worst 
part of the faiin, with considerable care : it was ploughed as de<?p 
ks four horses could penetrate with a large plough ; and one half 
was limed at the rate of from 60 to 70 bolls per acre, the othet 
half being dunged considerably more than usual : t\\e whole wa» 
^own with oats, and with rye-grass and cloVer sefed ; the crop was 
good generally, but the limed half was much superior to the 
dunged. The grass was cut for hay, and the part dressed with 
lime still preserved the superiority both in quantity and quiality ; 
and even during the winter, had a close verdure and healthiness 
upon its surface. 

Observations. — We have ever be^n of opinion, that lime caii 
lievet be employed upon land to so much advantage, as in laying 
down for grass ; and this experiment proves its decided superior-* 
ity to dung for that purpose. 

Observations on the method of laying dovm Pasture and MeddotB 
Land, with an account of some Pastures made ivith the Meadow 
JFescue Grass and Clwers. By Mr. W. Salisbury, ofBromp^ 
ton. — Trans. Soc. of Arts, vol. 27* 

The remark of the late Mr. Curtis, in his well-known work on 
the British grasses, that several of our native grasses are better 
adapted for the purpose of pasture than ray-grass, which is ,the 
species generally used for that purpose, is decidedly confirmed 
by the experience of the present writer, who has paid particular 
attention to this subject ever since the death of his late partner, 
Mr. Curtis. Mr. Salisbury expresses his mortification, that after* 
so much had been written on this interesting subject, and when 
other grass seeds may be obtained, that almost every person should 
be of opinion that they cannot be cultivated to advantage, though 
fie is ready to admit, there is much truth in it, when they are 
f own according to the common practice, which he has convinced 



508 Objurations on laying dovm Meadow and Pasture Land^ S^e, 

bimsoH to be erroneous. He is fully sensible, that many per- 
sons will deem it mailness to sacrifice the benefit of a crop of bar- 
ley or oats, where the land is in fine order, and while a good crop 
Oi s^rass can be had under it ; but to tiiis he replies, that there i» 
no land whatever, when left for a few months in a state of rest, 
but will produce some kind of herbage, good or bad ; and ob- 
scTves, how extremely absurd it is, to endeavour to form clean 
and good pasturage, under a crop that gives as much protection 
toevery noxious weed, as to the young grass itself. VVe^ds, it is 
remarked, arc of two descriptions, and each requires a diifcrent 
mode of extermination : thus, if annual, as the charlock and 
poppy, ihey will flour among the corn, arid the seeds will ripen 
and drop before harvest, and be ready to vegetate as soon as the 
com is removed ; and if perennial, as thistles, docks, couch grass, 
and along tribe of others in this way, they will be found to tako 
such firm possession of the ground, that they will not be got rid 
of without great trouble and expence ; and the subsequent trouble 
and expence of clearting the land, is thought to more than coun- 
terbalance the profit of the corn. 

To fully accomplish the formation of meadows., three things are 
itated to be necessary ; namely, to clean the land, to procure 
good and perfect seeds, adapted to the nature of the soil, and to 
keep the crop clean by eradicating all the weeds, till the grasses 
have grown sufficiently to prevent the introduction of other plants. 
The two first of these requisites being universally known are passed 
over; and the third is detailed, as it has been practised with the 
greatest success by the writer. He states, that grass seeds may 
Ik^ sown with equal advantage both in spring and autumn. In a 
particular instance, the land was sown in the latter end of Au- 
gust, and the seed made use of was one bushel of meadow^ fescue, 
and one of meadow fox-tail grass, with a mixture of fifteen pounds 
of white clover and trefoil : the land was previously cleaned as tar 
• as possible with the plough and hatrow, and the seeds sown and 
covered in the usual way. In the following October, a most 
prodigious crop of annual weeds of many kinds had grown up and 
were in bloom, covering the ground and the sown grasses, the 
-irhole of which were then mown and carried off the land ; and by 
these means all the annual weeds were at once destroyed ; and 
"while the stalks and roots of these were decaying, the sown grasses 
were getting strength, and the few perennial Avceds which were 
among them were drawn by the hand in fine weather. The whole 
was repeatedly rolled, to prevent the worms and frost from throw 
ing the plants out of the ground; and in the following year, thcr-c 
was a remarkably fine field of grass. 

Observations, — The method practised by Mr. Salisbury, of lay- 
ing lauds down to grass, is highly deserving of imitation : it, ^U^ 



New Theory i^tJie Diwnal Motion of tit flarth. 3(S 

Se found as beneficial in practice' as it is correct in i)ieoryv 
The system u&aally practised of sowing clover and rye.grasi 
iiinder barley, when it is intended only for a season .6r two to 
change the course of the cropj, artd to be returned again to arabl^ 
4s soon as the clover is iejcha1dste<l, oV (Overpowered by tlie weed& 
whirih gro\^ aniongit it, ih'ay b^ hs'efully continued in such cases, 
but where land is intjpnded for i^ermanerit pastuni or' meadow, 
the method i-ecotilmended iA tliis eominunicatioxi will produce a 
inuch better turf^ at a considerably less ex peace upon ilit 
whol6,~ahd in a niuch ^Hoirter time ; «nd it appears preferable td 
^ow the grass seeds in aiitumn on accdunt of the greater fa^ilit/ 
bf destroying the anil'usil ^eetis* 



iba 



mam 



NATURAL PHILOSOPHY, ARTS, and MANUFACTURE^ 



JVnu 'theory 6f the Diiirndl Motion Of the Earth roAnd its Aicis.^ Bf 
Professor Wooi>, Richmond j^cademy^ Stati 6f Virginioj-^Fhilm 
Journal f No. US. 

At the commencement of this circuiai* letter, Mr. Wood states 

that he has just published a work entitled " A New Theory of (he' 

l)iumal Itotation of this tlarth, demonstrated upon Mathematical 

{Principles, from the Properties of the Cycloid and Epicycloid ; 

with- an Application of this Theory to the explanation of the 

Various Phenomena of the Winds, Tides, and those ^toney^^nd 

inaetallic ConcretioiiSi which have fallen from Heaven (thift Atmos- 

phere) upon the Surface of the Earth." The idea of this under- 

itaking was nrst suggested by the fact that the velocity pjf the top 

i)f a carriage wheel in motion is greater than that of the bottom ; 

this Mr. W. conceives to be applicable to thai of the earth. TEc 

xiioLion of each ^oint on the earth's surface, except the two poles, 

being compounded of two motions, one a rotary motion about its 

axis, and the« other k progressive motion in its orbit ; Mr. V?» 

supposes that it will ** describe a curve of the cycloidal, or ratb^ 

^picycloidal species, possessing a similar property with the coni* 

itiion cycloid generated by a carriage wheel." This condition 

being once established for any point, a variation in the centrifugal 

force at that point must necessarily follow, and on this principle 

this author accounts for the tides, trade-winds, ^c. In order t^ 

afford a general idea of the principles oh which this theory is 

founded, three of the propositions which are deemed the most ini- 

portant are transcribed from the work referred to ; but as theas 

isahnot be easily understood independent of the diagram by wbicjt^ 

s5^o. 25.— yoL. vx; a s 



^ 1 Pro/eMor fFood on the Diurnal Motion of the £arti. 

they are accompanied, we shall refer to the original for these, uxA 
state the general results which he has deduced from them. In order 
to apply the forqaula derived from the last of these propositions 
jto the motion of the earth, it is supposed ^' to. move along the 
chord of an elliptical arc every twenty-four hoars, instead of the 
arc itself over, which it really moves/' From these premises, it is 
** deduced that the velocity of any point of the equator at noon is 
to the velocity of the same point at midnight as 3718 to 36*02, or 
as U034 to 1. In like manner I have found that the velocity at 
fline o'clock P. M. i& tothe velocity at one o'clock A. M. as 248*9 
to 241*4^ or as 1*032 to J.*' The effect which this difference of 
velocities produces on the force of gravity at the earth's surface 
is then subjected to calculation,- and it is stated that bodies under 
the equator lose a 9375th part of their weight at noon. It i» 
then assorted that the efect produced by this difference of gravity 
upon bodies situated at the surface of the globe is 306 times a« 
great as the effect produced by the attraction of the moon, and 
137^ times as great as that produced by the sun. These are the 
principles employed by Mr. W* to explain the phenomena of the 
tides, trade-winds, and of falling stones. With respect to these 
last, he supposes them to be projected into theataaosphere from 
volcanoes r ^^^ thttt the -point from which they issued had its 
velocity varied during the time of their flight, while the velocity 
impressed upctn them at the moment of their leaving the earth 
remained constant ; and consequently, that they would descend 
at a- greater or less distance East or West f^'om the point of 
projection, according to this variation. 



Observations. "^The first and strongest feeling excited in our 
minds by the perusal of Professor Wood's " New Theory of the 
Diurnal Motion of the Earth/' was that of surprize at its having 

'obtained' a place in this- highly respectable Journal. This feeUrig 
arose from our hope and . belief that Mr. Nicholson's acquaint 

'tance with' suhj.ects of this nature was much too accurate atii 
extensive to have admitted it on account of either its novelty or 
its correctness ; and we conceive that the following reniitrks will 
convince all our mathematical readers that oar sui^rise was odt 
altogetTjer groundless. 

We shall not dwell on Mr. Wood's inaccuracy in confounding 
cycloids with epicycloids and epicycloides with epitrbchoids^^ nor 

-on his error in making the earth turn the wrong way ; since these 
are points, which, however they may betray his want of mathe- 
matical knowledge and astronomical precision, do not immediately 

'affect the argument upon the theory which he has proposed." But 

' the simple statement of the case is tliis : That the velocity of each 
point of the earth's surface, as referred to the quiescent space occn^ 






frofessor JTood on the Diumai tifotiM of Ihc Earth. St t 

<f)ied by the sun and stars, is everj instant varying, cannot p6«sfUy 
be denied by those who admit its annaal ahd dfarnid revaldtionVbut 
it is equally certain that the centniugal forte depe^ndcnt on tfaii 
velocity, is at all times so eqiially compensated by the joint rifanlt 
of two coiK^tant attractive forrt s. differently combined, ibal no iii^ 
dications of its variation can possibly be exhibited in apy cen^ibR 
phenomena. The centrifugal forre of each> pafticle of the ^a/tfi 
produced by its revolution rcivvf\ the sun, is precisely counter- 
acted by the sun's mean attracuon ;'*lhe cep;trifuga1 fbeee derived 
frora its rotation round the earth's axis, v^ c6tfnteracted by i 
certain constant portioii of the force of gravitation ; and honir* 
«v(Br these motions may agree or disagree In direction, their inter* 
ference will not prevent the perfect validity of the coifipensationSy 
which will be singularly combined. At noon, th6 two centfru 
fjigal forces act in coatrary directions, and the centrifugal force^ 
^ependinjg on the annual revolution is subtracted frbnrtbat wbichr 
l>elongs to the diarnaU &nd on the other hand, the solar' attrae^* 
tion now acts in a^cection contrary to that of the gravitation 
^towards the earth. At midnight the two centrifogat forces are 
'United, and so 'are the aittractions. ^nd. thi^ would be eqoall/, 
(true if one of jthe motions were directed froti^ £^ai$t to West* and!' 
iiot both of them from West to' East. It is unnecessary to con- 
iirm this obvious explanation by any abstruse calculations : but 
for a single e^cample we will take a satellite i^evolvii^g rotiod 9^ 
|>lanet with a velocity equal to half of that of the planet in its- 
fiTb'xij and at one fourth of the distande ; the attractive fdrt^*" 
must then be equal, since the fprte is as the square of t%e ve!t>« 
4:ity divided by the radius: at the conjunction of^ th^ sun and ' 
/satellite therefore, the attractions completely' balance each other^ 
consequently the joint centrifbgal forces ought to disappear ; but 
the velocity is only reduced to pne half ; the curvature therefbrci 
n^ust vanish ; and we shall find from the properties oftfae epitro* 
.cboid, that the distance of the centre of curvature does actually, 
iq this caaie, becon^e iniinite. See Dr. Young's Essay on cy- 
.cloidal curves. Prop. 4. Nat. Phil. II. 559. Av\A a similar de» 
moDstratio]^ might easily be extended to all possible cases. 

These circuits tances were certainly of sufficiisdt importancir 
if> have deserved the consideration o( any prf)fmof',\fBioTB lur^ 
jSu^bmitted l;^i,s new theory to the learned in the mat]{;iematical an^ 
physical sciences, and solicited their opi^iion (may we not s^y * 
xfieir condemnation?) of his hypothesis. And were they not dl$^ 
sufHcient, to have induced the learned editor of the Philosophicail 
Journal, to pause before he &ullied the fair reputation of his Vork^ 
hy the insertion of such crude and absurd theories. 

It ought likewise to be remarked, that if Mr, W/s coticlusioo 
relative to the different velocities of any point, of' the equator 
^i f^oon ai>d jmidnight could be admitted, he appears to be eqqally 



Jitf MnEdgoporth at^ TikgrMphic CommunkaHonM. 

^forttt&ate in bis application of it, to the explanation of Aerolithi* 
jf>r falling stones. Many instances might be produced, to whicH 
)iis (beorj seems totally inapplicable; but we sball meptioi^ 
poly opfi ; Qn the 13tb of December, 17^5, a large stone^ 
Weighing 56ilb, felt ^eai ^Vold Cottage^ Yorksbirj^* The three 
prinripal volcanoes ra £|irppe^ ^re £ipft, Vesuvius, and Hecla; 
the ^irect distance between the place where the stone fell and 
ihe last of these, is abo^t £|00 miles; between this place and 
Vesuvius ^Iniost 1200; %nd between it and Mount Etna, near 
)d.50 miles. The difference of longitude between Wold Cottage 
•od Hecla is about 19 degrees ; biptween h and Etna more than 
J 6^ ; and between th^ pla^e of iU lall apd Vesuvius near IS 
degrees. t^oul^ these distances b^ reconclledi Vith Professor 
food's theory, even if ^1 the places lay on the 'same parallel 
of latitude } If the stone were supposed to be p^rojected. from onc^ 
of the Tolc^ic mountains in Aoierica, the hypothesi^ would be 
«till more uutenab}e* 



On Telegraphic Communications* By Richaii]> Lovell Ebgx- 
vroxTH^ Esq.-^PhiL Jaiim. No, 118. 

At. the coipmeiicement of this letter Mr. Edgeworth refers to 
^D essay of his on t^e subjec^, published in the Transactions of 
^e ]^o.)al Iri^h Acadeii^y, at the ^o^clusion of which he ventures 
1^, predict ttie futqre universality of telegrapbic communication,! 
" whenper arts and sciences have civilized mankind.'* He thctf 
Observes/ that among the various inventions for facilftatihg thi^ 
tcode of conveying intelligence he has seen one ideuOminated ^ 
]M>mocraph (see our present volume, page 4^) invented by Lieu, 
tenaor Sprat^ ;^ and states that \i^ )iad actually practised a si* 
ixiilar contrivance Jwelye or thirteen years since. This state- 
ment he affirms is not made with a view of derogating from the 
inerit of that gallan^ biiicer who is the author of the method 
aibove referred to, but with a desire to give bim the advantage 
of what much experience had taught Mr. E. and of which £• 
li^ drawn up a particular aipcouut for the purpose of recommend-^ 
iog tpe practice of it to ^e army. ' From the circumstance of 
IijB^t^Ift ^fT^it having pointed out the convenience of a dark 
object hebin<] the man that makes the signals, it appears that he 
hadconfine<^ his method to' a single post, f^qm xht place whence it 
iqconveyed;liutMr»|J. renqarks, thai the intelUjence may be con-» 
'veyed to any distance by men only, an4 without any other ap^ 
•aratus than a telescope; and that consequently there is not anjr 
bpundsto this mode of communication but the ocean. For thiii 
purpose, however, the signal man must be visible fr^m botli( 
t^ijore s^' behind. In Mr. Spratt's arrangement there is asi^* 



Mr. Edgewori\ 4m l^kgraphtc Commmicathns. 91^ 

^ai to^sTgniiy that the operator is understood ; but Mn £dg«? 
^orth conceives that this is best ascertained by a repetition of 
^he sign4l received ; as this in a long tiipe of comoiiuiication will 
pot occasion any d«lay except at the second station. Mr^ £dge>- 
worth ^also remarks, that either andrograph or. homwtcribe would 
)iave been a mofe proper nam^ for this contrivance than .that oS 
hamo^aph \ and concludes^ with the following observation : ^^ that 
if generals of largp armies would employ the resources of ait 
as well as those of mere physical force, they would s^€ much 
-iinie an|) blood; they ijpoald avoid much disappointment and 
disgrace ; and whether they ultimately failed, or succeeded^ thegr 
would hitve the satisfaction of knowing, that (hey bad laegleeted. 
90 reasonable means, of ensuring success." 

Observations^ — However similar these two metbojs of convey? > 
ipg intelligeqc^, invented by Mr. Edgeworth ^nd Mr. Spratt, 
j^ay be, ther^ c^i> ]it no dqubt that they originated altogether 
indep€ndei)t]y of ea^h other]; aqd consequently ths^t each author 
is entitled to the Qierit of invention. 3ui we conceive that it if 
i)ot he who first conceives the idea of an invention, but he who 
first carries that idea into practic^, ^nd coinmpnicatei his succesii 
to others, that has the greatest claim to public approbation, anc] 
our readers wil) not hesitate (o allow Mr. Spratt t^bis kind of 
priority. At the same time, as there is no reason for doubtii^ 
the truth of I^lr. Edgeworth's assef tion relative to the priority 
qi the inventioQ, there can be v po just reaspn (or withboldin|^ 
from him *his due proportion of meiit on this account; an4 ' 
bpth the ^V^nsi^n of the distance to which intelligence may b« 
conveyed by ibis method, apd the repetition of the signal received 
.ipstead of a separate one being made to denote its being under-r , 
stood, as pointed out by li'lr. £• are certainly in^provements 'on 
the method communicated to the public through thfs medium o^ 
tjie Society of Arts, by Mr. Spratt. 



warn 



wmnamm 



J. Observations on^ Dr. BosxqcK's Remarks upcm Meteorology^ 
By LvKB HpWARD, Esq,'^PhiL Journ. No. H8. ^ , , 

^, On Meteorological Nomenclature^ in anrmr to Li>ki Howaub, 
]^ % J. BosTJocK, ikf. £J.--J6id, No. U9. 

3 .— ^1k the first of' these papers^ Mr. Howard appears to have 
jB^ double object in • view; viz. to defend his nomenclature an^ 
system against the objections offered by Dr. Bostock, and tq 
offer some remarks, relative to tht inaccuracy of the terms use4 
by Dr. B« in his Meteorological Journal. Dr. B.'s observation, to 
Wtiich Mr. H. principally replies is tbis^ '* I am not unavrare^ 



514 Remarks OH Mftrorohgy. 

tbftt a scientific Domenclature for the appearance of clouds has 
been attempted by Mr, Howard, but I hope f shall net be accused 
of presumption, if I give it as my opinion, that his set of names 
is much too confined, to be of any use, and that the hypothesis 
on which he proceeds, is not entirely correct." The noiAencla- 
t«re to which this sentence refers, imposes names on seven 
iliodificatifons of clouds only, (seepage \$7ofcut present volttme) : 
bat these Mr. Howard remaiics are so many genera, some of 
which. comprehend several species, running'* through gradations 
so deUcate, and combinations so varied, that the leisure of a Ipng 
life might nofe more than suffice, accurately to observe and 
describe Shem/' He also adds, that he has not seen any reason 
since 1804, either to augment or diminish the number of these 
modifications : not that he deems the system perfect, but because 
h answers the intended purpose. He likewise thinks a multipli- 
cation of terms in the present «tate of meteorological science not 
at all desirable. With respect to the erroneous hypothesis alluded 
to by Dr, B. it is titated to be that of Dr. Daltbn on the constitu- 
tion of the atmosphere, to which Mr. H. had recourse, in illustrat- 
ing his speculations : and he now refers to the article cloud in 
Dr. Rees's Cyclopiedia, where the natural history is given indc^ 
pendent of hypothesis. 

Mr* Howard ne:xt offers some observations on the terms em- 
ployed by JJr.'libstock, to denote the different appearances of the 
ibloucls, ' the motion of the wind, ^c. and at the same time 
^sw€rs' some objections to his system, urged by Dr. B. in the 
'Annual Review for 1 804. To most of these terms he objects, 
'as being either imperfect or inaccurate ; but as he examines 
.each of them singly, and also discusses some facts to which they 
'relate, the particulars would exceed the limits we can allow the 
present article, and we must, thereforeji refer our curious meteoro*, 
logical readers to the paper itself for these objections. 

2.— Dr. Bostock first expresses his surprise at Mr. Howard's 
strictures on his meteorological observations ; and then observes, 
that he had long been in the habit of making meteorological 
observations when Mr. Howard's Essay on that subject appeared^, 
amd that the first impression it nnia(][^ "P^^^ ^^^ mind was very 
favourable, as many of the terms appeared tg be both charac* 
teristic and judicious. TH«se terms he employ/ed in his own diarv, 
Svith both the desire and expectation of finding thimn materially 
ueeful ; but he states, that he found them on triol tq be inador 
quate to the expression of the di^erent atmospherical appearances^ 
which he thought of sufficient importance to berecoixled; ao^ 
^herefort, after some time he discontinued their use. Whether 
the defect was really in the nomenclature, or in his uoskilfulness 
in its use, he does not attempt to decide ; but thinks that the only 
efiectual method of evincing its minuteness and potnnrthepsioiiy 



s Aemarks an Meieorotogt/, iill 

V^^ilt be for Mr» Howard to produce a specimen of a diary con- 
strue ted after the manner of his ; or so as to afford a couiplctcf 
history of the atoiospherical phenomena of each day ; and avowt 
his confidence)' that Mr. H. vrill readily admit tke utility of saoll 
a series of observation^. With a view of shewing that he is not 
influenced by any selfish desire of making way for his own peculiar 
opinions at the expense of others, Dr. B. asserts his readiness ta 
enter into any plan of co-operation, which may appear to afiford 
the greatest fecility in the execution of his project. 



•aUttm'^^i^ 



Observations .-^Iti the study of the variable phenomena of the' 
atmosphere, and the art of deducing probable conjectures relative 
to the future state of the weather, we conceive that great attentiont 
should be paid to the strength and direction of the winds; to the' 
variations in atmospheric gravity or pressure ; to the degree of 
its temperature, and the changes which it undergoes ; to the state 
of electricity which it exhibits ; to the degree of moisture which 
it contains; and to the visible and various phenomena that are 
supposed to depend upon, and to result from these circonistances^'' 
either separate or in a combined state of operation. The ability 
of foretelling the future state of the weather, which the plough* 
man, the mariner, and the fisherman have attained by experience 
alone, we are inclined to regard as a very favourable indication^' 
of what may be dope by the assistance of philosophical instru- 
ments. It is by means of these,. that the causes, from which the 
variations in the visible phenomena of the atmosphere arise^ * 
must be traced ; and the greater the variety, both of the observa-. 
tions and of the places where they &re made, the greater will be 
the real progress of the science of meteorology, arising from a' 
cafreful comparison of the results. In order to ensure the utmost 
facility, acciiracy, and extent to this progress, a co-operation of' 
all those gentlemen, who may have inclination and opportunities 
for making observations and experiments of this nature, is cer. ' 
%^inly desirable, if not absolutely necessary. Instead, therefore, 
of meteorologists entering into discussions of a controversial aad* 
personal nature, and often exhibiting specimens of that angryr 
discordance visible in the element which constitutes the object- 
of their study, we should be glad to perceive that harmonic order 
pei;vading ail their labours, which the results of their researches 
must ultimately obtain, before they can be admitted as the con- 
:ted and 'connecting links in the chain of mete orologic<\l science'r 



t 3t6 ) 



k 



lemarki oh Mr. Richaud WaIkeiC's propmed Alterationf in iht 
Sc4iie$ of Thtrmamcters. By Lo n Dt n en « is. — PhU. Mag. No. 1 4f . 

The author of this article tliinks that the various improve- 
tnents and suggested reforms in the weights^ m^asures^ and modes 
iif e^tinfating quantities, in hoth this and other countries, hav« 
been chiefly neglected on accoiint of their authors not having 
assigned *' new and appropriate names and characters to the new 
<fenuminations or things, which it was their object to introduce ;*' 
but instead of this, they (lave generally applied the old names to», 
things very difterent from those which they had been previously 
used to designate. It is conceived thdt, if the most precise c«m* 
pou\d words in the Greek ot Latin languages, indicating the diffe- 
rent degrees of heat, were used as new affixes to the number oH 
thermometric di'visrons proposed, instead of eithei" the word 
degrees of th^ characiet ° in use at present, the alteration pro- 
posed by Mt-^ Walker wi^iild, perhaps, te adopted by many. A$ 
distinctive characters for the diflerent (fegrees, the initial Greek 
letters by which they are denoted, mij^ht answer t^e purpose. 
** Negative signs would thus become unnecessary, and no confu- 
sion could arise frc^m their iise; while oh the otber hand, every 
true friend of science and accuracy, witi naturally adhere to the 
divisions in t/^e, At answering their intended ends, although not in 
the best or moSt perfect manner ; and set their (his) face against 
imperfectly contrived changes/' This writer also thinks that a 
material (ircumstabce in. the use of mercurial and spirit 
fherm6meters has been omitted by Mr. W. viz. the difi'eien^ 
periods of time necessary for each to acquire and indicate the 
temperature of aby medium under experiment. 

Ohservationk.'^Tbr a description of Mr. Walker's proposec| 
alteration in the scale of thermometers, we miist refer to page 
^7 of this volum<f. We canilol lielp thinking the plati suggested 
by Londinen^is toO op^roSe and intricate, eiihei' fur v^egance or 
for utility. 

Note^f relative to a method <^' constructiitg icooden Bridgis* Bjr 
M. WiEBEKiNG. — PhiL Mag. No. 148. 

M. Wlebeking, director of roads and bridges to the king of 
Bavaria^ has discovered' a mi&thod of constructing wo(klen' bridges,' 
trfaich in point of strength and solidity, promise a duration or 
teveral centuries. They are also remarkable fot the elegance of 
thmr iorm^ and the width of the arches. A bridjje has btten cojk* 



Note respecting the CoriMtructum. of Wooden Bridges. ZVf 

siructed on the above plan over the river Roth, five leagues from 
Passaii, consisting of a single arch t^vo hundred feet, wide; 
another has been made for a large city, two hundred and eighty*, 
six feet wide. These arches naay be so constructed, as to «diiiit of 
ships df war or merchant vessels passing through them, an apei'* 
, tyre being made la the centre, which can be opened' and shut at 
pleasure. Another advantage possessed by these bridges, is that 
of being speedily taken to pieces, if it be necessary to stop the 
progress ofan-enemy ; the arch may be rwnoved in one day. and 
the abutments «in. another^ without cutting the smallest pieca 
of timber. 

With respect tt) the advantages in ecomuny resulting frdm tb« 
adoption of M. Wiebeking s plan, it has been estimated that a 
stone bridge of similar dimensions to a wooden onn of a given size 
would eost two millions of florins, whereas the latter would cost 
only 50,000 florins; and on the supposition that a wooden 
bridge will only last 100 years, it foUows that, taking the interest 
on the .principal sum: into the. computation, there will result ^ 
saving of eleven millions six hundred and eighty thousand florins/^ 

Obt^roettwHSn'-^li the, circumstances recorded in ^^^ ^^^ ^^ 
correct, tfai^re can be no doubt of the iihportance of Mr. Wiebe**^ 
king's invention : and particularly in many places on the con- 
tinent, where wood is -^ comparatively cheap. But as we ar^ not 
furnished; with auy description of his method* we cannot form 
any opinion relative to the stability of its principles. 



On Pendttlams. By Ez. Walkek, Esq. — PhiL Mag. No. 148. 

INI II. Walker observes ;that, whether any real improvements 
have been made in the inec|ianism of pendulums since the days of 
Harrison, is a question on which there are a variety of opinions. 
With a view of reducing, th^ gridiron pendulum to a more simple 
form, rods of the softer met^l^^have been substituted for those of - 
brass ; but experience has proved that ihey do not long retain the 
same power of expansion and contraction under the pressure of 
the lens. MV. W. also states, that Mr. James Bullock told him/ 
that brass and steel were the only metals, that he could depend 
upon in the construclioq of compound pendulums. The construe* 
tion 4»f the; gridiron pendulum is founded upon the supposition 
that its length is preserved invariable by rods of ditferent pnetals, 
which have their lengths djaly proportioned to their powers of 
expansion and contraction. But several objections hav^ of latt 
heen urged against this mode of compensation.^ " The principal, 
of these objections are.: 1st, The length of the pendulum may be 

X increased by its weight; 2^4^ Where the rods* pass through tbtf 

^jNo. 25.-rVoL. VI. 'ST 



9 IS • tAfr. Ei. Walker on PendMtwm. 

connecting bare there is some friction, which caas«0 them to 
inbve by starts, and not according to the increase and decrease of 
heat ; and 3dly, The difficulty of exactly adjusting the lengths 
of the rods. But there is another source of error in this pen« 
dulom, which has not, I believe, been attended to by writers on 
th\i subject." This source Mr. \V. states to arise from the tno** 
tions of ihe cross bars altering the distance between the centres 
of suspension and oscillation, unless the weights of these bars he 
adjusted to their motions. * , 

- Mr, \V. then employs the method of fluxions in investigating the 
proportional weights of these cross pieces, in order that the dis^ 
tance between thp point of suspension and the centre of gravity 
of the pendulum may remain the same at all ten^peratuits ; and 
concludes that, ^^ if the weights of the crosa pieces be inversely 
as their motions, they wilt not alter the distance of the point of 
suspension from the' centre of gravity." An attention to this 
particnlar, he thinks, would improve, but not perfect the gridiron 
pendulum; and therefore he conceivesjthat a pendulum of a more 
Simple construction, and more easily-adJMStable to different degrees 
of heat and cold, is still a fie si r able object with the astronomer. 
^ The mevcurial pendulani," he asserts, ** is founded upon prin- 
ciples more simple' ai^l correct than *any other compound pen- 
dulum that has yjtt been invented." ^.Tihe objections to which it 
^as liable on account of. its glass rodj are now obviated by the' 
substitution of a steel rod, with a^gUun vessel contadning quick- 
silver attached to it ; -.so 4^hat when the vod expands- dowutv^rds, 
the quicksilver expands in a contrary direction, and vice versa. 
The compensation is to be adjusted by the quantity of quicksilver 
in the tube ; and which, is consequently to .be increased or di' 
mmisbed accordingly. 

This communication is accompanied with a register of the 
going of a clock with a' pendulum of thisltind, from the 27 ih of 
June, 1809, to the 12th of July, 1810 ; from this table it appears 
t))at the greatest daily variation m the rate of going of the clock 
s^dom exceeded one second, and^then only by one or two tenths. 
TThe rate of going was computed from the son's transits over the 
meridian, observed by a transit telescope of 3| feet in length. 

' ' Oft/^rTflf/ow.— Most of our readers, we suppose, are aware that 
the gridiron pendulum was the invention of that very ingenious 
artist, Mr. John Harrison, celebrated for his invention of a 
V^atch for finding the longitude at sea, about the year 1 7^5 : and 
that it consists of five rods' of steel and four of brass, placed iq 
alternate order; the middle rod, by which the pendulum is sus- 
pended, being made of steel. Simple and ingenious;as the con- 
struction of this pendulum w^ at the time of its invention, we 
think that other objections might be urged against it; beside 



e' 






Jl/r. £z« Walker on fmdulum* 319 

those mentioned by Mr. Walker. Tbe chief of these are the 
difficulty of proportioning the thickness of the rods, so that they 
may all. hegin to expand or contract at the same instant ; and 
tlie gieat resistance which it receives from the air. 

The mercurial pendulum^ to which Mr. Walker gives the pre- 
ference of all others, was invented by the ingenious Mr. Graham, 
about t^e year 1715 ; and there ai*e doubtless many strong proofs 
of its practical excellence. We conceive the most forcible objec- 
tion that has been brought against it is, that the expansion of the 
mercury commences sooner than that of the glass rod : and for 
this there is certainly not any remedy provided by attaching the 
glass tube to a steel rod, as mentioned by Mr. W. We should 
certainly be glad to record -Mr. Walker's invention of such a 
pendulum as be thinks so desirable an object to astronomers ; 
while at the same time we may be permitted observe, that we. 
hope it will shortly fall within our province to notice one from 
a different quarter, which has been both invented and .tried for a 
considerable period ; and in which both simplicity and accuracy, 
!are united in a very high degree. 

As we are desirous of making our work the channel of as much, 
practical Infonnatiou as possible, it may not be amiss to notice 
tjie following excellent mode of effecting a compensation, which 
we conceive has not been so much practised as it deserves. It 
is described by M. Thiout, a French writer on clock*making ; 
and was used by an ingenious artist in the north of Englaiid, 
about forty years ago. A bar of the same cqetal and dimensions 
as thi^t which constitutes the rpd of the pendulum is fixed to the 
back of the clock-case. . From the upper end of this bar a part 
prqjects, to which the upper part of the pendulum is connected 
py tiyo fine pliable chains or silken strings, which just below 
pass between two plates of brasS) the lower edges of which will 
always t^ern{)inE|.te the length of the pendulum at its upper extre- 
mity. These pls^tes are supported on a pedestal fix^d to the back, 
pf tl^e plQck-case. The bar rest^ upon a moveable base at the 
lo\yer e^d^ ^^ is inserted in a groove ; by this means it always 
retaii^s the same position. Fnim this construction it is evident, 
tbi^t ^he exipan^ion or contraction of tbe bar and the pendulum 
rod will be ^qual, but in contrary directions. For supposing the 
rod to b^ txpii^nded any given quantity, then as the lower end of 
the bar rests ^pon a &xed point, it will be extended upwards, 
and raise the pendulum just as much as its length was iacrease^ 
by tbe additional temperature; and consequently its length. 
below tbe plates will be the same as before. 

It must not, however, be understood that the bar ^d the pedes* 
tM^ aie tQ be fixed to the back of a common clock-case of wood, 
since this would be merely 1^ substitute the variation of the wood 
ioT that Qf the metal, aud since all wood is liable to great varia*. 



920 Mr. Ez. IValker on PendiUims. 

tton in ito dimensions from moisture ; but the apparatus must be 
fixed by meaoK of stone work, or of some other siibstanlre little 
liable to expansion : and in the arrangement described by Dr. 
Fordycc, Ph. Tran». 1 794, even the expunsioti of the stone is 
compensated by making the 6xed bar a little longer than tlie 
pendulum. ' 

■ ■ I ■'■'' "ii 

« ' • 

Expenments on the comparative pawert of Cylinder and Plate 
' Electrical Machines y and an a mtons of doubling, trebling, qua^ 
' drupling their chargivg poxjoer^ ^ -A/r. John Cuthbkhthon, 

and Mn G. J. Singe it. Contmunicated by Mr, Singer.— 

Phil.Joum. No, 118. 
• Mr. Singer stales that the opinion pf electricians has been 
ninch divided respecting th^ best form of an electrical machine. 
Globes, spheroids, cylinders and plates have been alternately enu 
ployed and recommended by different Experimenters. Only very 
slight effectiB were formerly produced; and " the much im- 
proved construction of the cylinder machine by Mr. Nairne,/ 
the experiments on electrical excitation by Mr. Nicholson, and 
t!ie structure of the unrivalled Harlem apparatus by Mr. Cuth- 
bertson, are the circumstances that have most enlightened this 
subject." The influence which apparently slight causes have 
upon results in experiments of this kind render it necessary, in 
order to obtain any accurate companson, that the two instru- 
ments should be used at the same time, in. the same place, and 
under' similar circumstances; and these were particularly at- 
tended to in these experiments. 

" The instruments employed for comparison w»erc a cylinder 
of T4 inches diameter (with a multiplying wheel, and pulley, 
the proportionate diameters of which were as four to one), and a 
single plate machine of 24 inches diameter, turned by a single 
winch, as usual. The management and excitation of each ma* 
cliine were undertaken by the individual who had constructed it, 
and an equal advantage was thus afforded to both. To insure 
greater accuracy, the results noted were in all cases the mean 
result of repeated experiments : without this precaution, tbe 
sources of anomaly would be much more frequent and numerous.'^ 
These experimenters consider tbe gradual increase of charge 
conveyed to a known pleasure of coated surface, and the liision 
oif certain quantities of wire, as tbe best test of electrieal action ; 
but in the course of their experiments ti>ey bad recourse to every 
known means of ascertaining comparative quantities. In the first 
part of this series of experiment many ditliculties were encoun- 
tered; but aft«fr these were surmounted, the mean result of near a 
hundred trials, tended to prove that the charging power of the 
two machines was precisely equaU ... 



y^ 



/ 



* * 



Comparative Expmments vn electrical MacMnes. 3^1 

In the first of the experiments cited here, a battery ©f 15 
jars, expoeiilg aboat 17 square feet of coated surfare, was charged 
by the cylinders with Cuthbertson's electrometer placed at 13 
grains : the charge was effected by ISO turns of the wheel, 
and 48 inches of iron wire 1- 100th of an inch in diamelttf*, 
ifi ere rendered red-hot and fused into balls. With the same ar- 
rangement, the same effect was produced by 138 turns of the 
plate. And ii^hen the two instruments were used together to 
produce the charge, the same effect was obtained by 6*5 turns of 
each. This is just half the ft umber of turns thatt was required 
by the most favourable action of one, and aHoixIs a complete * 
proof of the similarity of their |>owers. The 48 inches of wire 
that was fused in these experiinenls was also found to be a good 
measure of the force of the charge eniplqyed : for on repeating 
the experiment with 49 inches of the same wire, it was barely 
rendered red-hot. The power i^ecessary to put each machine in 
motion was next tried by suspending weights from their handiles 
in a horizontal position ; and it appeared that the plate required 
8lb6. and the cylinder iOlbs. to produce the same change of 
position. After some alteration, however, had been made in the 
rubber of the C3rlinder, and it had been furnished with new 
siik, it was fouiid that its power had been increased by oiie^ 
third. 

After the experiments had proceeded to this point, Mr, 
Cuthbertsun discovered a method > of improving the , plate ma* 
chine by means of multiplying wheels. A second series of 
experiment^ was then iuscituied, which our limits will not per'- 
niit us to particularize ; but which are stated to have sufhciently 
proved the utility and importance of Mr. Cuthbertson's improve- 
roent, bywtikh the original charging power is quadrupled. 
Messrs. C. and S. think that this principle is capable of being 
carried still farther ; and observe ** it is fair to conclude, that, 
by the proper a,pplication of a moving power, the quantity oi 
electricity given out by any machine in a determinate time may 
be doubled, trebledy quadrupled^ or even increased six or tenfold^ 
The discovery of this principle is therefore of the highest im- 
portance, as it offers the most effectual and ready means of ob- 
taining a very considerable accumulation of the electric fluid ; 
a circumstance of considerable interest in the present state of 
electrical and chemical science. These remarks are succeeded 
by statements relative to the comparative advantages of the two 
machines, which are as follow : 

** The principal advantages in the cylinder are, I st. the posi- 
tive and negati-ve powers are obtained in equal perfection ; 2nd.' 
it has but one rubber to, keep in order ; 3rdly, it is less liable 
from the security of its form to accidental fracture than the 
plate; 4thly, its insulation is more perfect; and dthly, from 



392 Discwerie* in tie Theory ^ Gamtis^ hf Daerfel ani Hevdius. 

the peculiarity of its structure larger multiplying wheels msiy be 
iBinployed, {^q4 th^H ^ CQnsiderc^fa^le 4i(uif)uti(m of its friction be' 
obtained. 

** Th^ advantages of the plate machines are, 1st. they are 
Jess e2(pensive than cylinders of equal power ; 2adly, they oc- 
cupy less room ; 3rdly, may be constructed of a much larger 
size, as instanced by AIr« Cu^hbertson's l^rge niachiue at Har^ 
km ; 4thly, several plates, to act jointly, may be more easily 
fCHxibined, than severa) cy^nders could ; 5tbly, the multiplying 
Bower may be applied to tbent to a much greater ej^tent, than 
It could to cylinders, without rendering the inotioq too rapid ; 
(Sthly, plates of equal diameters n^ay be made to act with a 
uniform and to^ degree o( power, ^ ci^uR>sta^c? aeldoot 
c^t^^t^K^ec^ b^ cylindiyrs,'* * 

Observations, "Tj^^ fully agree with Mr. §i^ger respecting th? 
importance of a ready and effectual means of obtaining a consi- 
Arable accumulation pf the electric f)uid;| more especially iq 
the present state t)f electro-chemical scie^ice, w^^en th^ gepius of 
invention is qn the wing, and, though s^he has already soared ^ 
high, appears • to be hovering only f(>r fre^h powers tq co^iduct 
her to further discoveries. The coinclusion$ at which the^e ^x-. 
perimenters havf arrived, seem to be warranted by their ex- 
periments ; but as Mr. S. observes that ** many experiments 
remain to be made, and when a suilicient number of thest 
kave been completed, 1 shall not delay the communication of 
them to the public/' we shall not protract our rf marks i^t 
present. 
> 

On the Discoveries ichich Daerfel and Hsvstius, made m the 
Theory of Comets. By J. C. BuaCKiiAHBT.«-C9it«atMafice c/ei; 
Terns for 1810. 

Daerfel, rector of Plauen in Saxony, published a smal) 
work on the comet of 1680, which is very scarce ; and it has 
been asserted that Daerfel was acquainted with the true para, 
bolic motion of comets before Newton* The late M. Lalando 
requested an explanation of this subject in Zach*s Journal, but 
he did not receive an answer. Delisle is said to have procured 
a manuscript copy of this work, and made a Latin translation 
of it. 

The Cometogr^phy of H^velius is not so scarce, and has b«en 
employed and cited by Daerfel. Besides, Mess. Lalande and 
Pring6 differ respecting tiie discoveries of that author. Heve*- 
lius took four observations and sought a right line which repre* 
seutedthem; this gives him ttie vdocity of the coqaet for the 



Dlsbffverle* in tie Theory ofOiJmii^, by Dd^fel and HeViUnB. ' 5^' 

tbrce intervals coGtatned bf^ween the four ■ observations ; he iii« 
Ibi-s from it the. diurnal motion for every day, by supposing the 
variations in the. velocity pr^ppitional to the times, and he com 
eludes with comparing this theory with all the observations of 
the comet. Hevellus has also applied this method to all the 
Gome^ts observe^ at that time, and derives the following results, 

1. Comets do not describe a right line, but a curve concave 
towai*dt the sun ; this corve he supposes to be a parabola. 

2. The veloitity of comets varies, but in a regular manner^ 
and proportional to the times. 

3. The greatest velocity takes place at the perihelion. 

4. The velocity is not the same at equal distances before and 
after \he. perihelion; 

3. The velocities of different comets do not follow any fixed 
law. 

Hevelius has not demonstrated the motion of comets m a pa- 
rabola, liut he has conjectured it 'in a happy manner, and that 
eonclusion wa!s the result of great labour. The little agreement 
between this hypothesis and observations induced him to imagine 
that comets soir(etimes quitted their oi:bits towards the' ei^l of 
their courses. 

In Daerfel's work, the first section is occupied with liis ob. 
tervations on the comet of 1680. In the second section he en- 
quires whether" there were two comets or only one, and decides 
for the latter.' An elliptic drbit not agreeing with these observa- 
Aons, be' tried the parabolic hypothesis which Hevelius, had pub* 
V Irsbed in his *C^metography. Daerfel, howpver, employed not 
the calculus,' but contented himself with a construction. In 
otder to correct and ftetfect the theory of Hevelius, this authcnr 
proposed to place the dun in the face of the paral^olas. He states 
that Hevelius had not been explicit respecting the place occu- 
pied by the focus, but adds that- the preceding comets were not 
so favourably situated as thls^ for making the discovery. He' 
observes, ** if this discovery be. found true, it will not be difficult' 
Upr those who are acquainted with conic sections to indicate me- 
tbods of calculation for the theory of comet8> in order to find the 
distance from the vertex of the orbit to the solar focus, and con- 
sequently the ratio of the diurnal motion in the trajectory, the 
distance from the earth, and in certain cases the true distaiicb 
from the sun. 

In the third section, Daerfel shews, contrary to Kepler; that 
comets do not furnish any proof of the ti'Uth of the Copernican 
system, declares for that of ^Tycfao, on the authority of the 
Hible, and asserts that it was only on account of the facility of 
tbe calculus that he adopted the former in what preceded. In the 
next section of his work, this author proves that the apparent 
zuotioD of the comet was not iu a great circle ; and in that which 



^24 Discoveries i^ the TheQrj^ of Sonuis^ by Daerfel andtfevekUs 

succoedsy. be »hcw8 how tf> find the horizontal parallax of the* 
comet by the variation of its pavallax in altitude, and from v^bicti ' 
we may conclude that of the sun trhen the comet approaches 
bear the earth » 

«- From what precedes it appears that Daerfel had made an 
important discovery^ in proving that the sun occupied the face 
of the parabolas described by comets ; and also that there still 
remained anothei' grand step to take, viz. to ^pply the laws oi 
Kepler to the parabolic theory of comets. 



' Ohscrcaiions,-^-tn this paper, however curious and interesting 
as relating to the history of astronomy, it seems to us to be 
somewhat too much M. Burckhardt*s object to establish the 
priority of Jinowkdge respecting the parabolic theory of comentar/ 
motion in favour of Hevelius and Daerfel, wt the expenc^ of the 
well-earned fame of Xew ton. This nc think is more than either 
has been or can be done.. The Cowt7o »t^;7 Aifl , of lie veliui^^ 
above referred to, was publislied in 1 66*8, and copies of it sent to 
Dr. Ilooke and several nembers of the lloyal Society of London; 
and Newton was certainry acquainted with it, as he both refer* 
to it, and quotes from it in that part of the third book of the 
Principia which treats of comets. With Ilevelius and Daerfelj 
the parabolic motion of Comets was naerc conj,ecture,'.arising from> 
accidental circumstances, rather than weJl*grounded or tiemoH', 
strated ktwickclge. Newton seldom stopped at conjectures, and 
when he did he proposed them in the. shape (;>£., queries, rather 
than aflirmed them as facts. He generally brpught theni to tl^e 
test of geomctr}', and either demonstrated their truth,, qr, shewed, 
tiiem to be mere suppositions. Respecting comets^ be first sup.- 
poses (Principia, lib. iii, lem, 4. cur. 3.) that they are " a sprt of 
planets revolving in orbits, .returning into themselves with a per», 
petual uiotibn.*' He then proviis, in Prop. 40, that *Mfcoiaet;5] 
revolve in 01 bits returning into themselves, those orbits will be 
ellipses ; and tbeir periodic .times be to the periodic times of the. 
planeis in the sesquiplicale proportion of their principal axes ;' ; 
and still further, that ** . their orbits will be so near to parabolas 
(in the parts near the perilielion) that parabolas may be used for 
them without error." Hence it is evident that what the roost 
illustrious precursors ol Newton only guessed at, he has demon- 
strated ; and thus laid the foundation of his fame, even ^in this 
respect, on too elevated and permanent a rock to bp eitlier over-*, 
shadowed by prejudice or over^hrawh by envy. 



( IM ) 



1, On the Action of the Electric Fluids by which fm IrmCyUndit 
afyinch and a half thick vms torn ttsunder: in a Letter ffom 

:■ Mr. *** to J. C. Delamei HER-iE.— /jt^iim. de Phyt* vol. 6$^ , 

2. Remarks on the Preceding Experiment. By J. C. DblaHI-^ 

' 1. Thb author ^)f this letter states that be half filled a ne^. 
''lallic cylinder with water. The cylinder was open at one end; 
and in this water he immersed a small leaden rod, which was 
surrounded wUh iron at the place where it entered the cylinder, 
jA order to «(fect ite insulation. He then formed a coummtinica''' 
tiOR between one of the surfaces of a pdwprful. electric battery anp 
the bottom of the cylinder, and also between tbe leaden rod and 
'tile' other surface. The explosions were strong ; the water ofteiv 
violently ^ected ;. atid the rod thrown to a considerable disCnnce ; 
and after several of these explosions the cylinder was tom* This 
vrriter was desirous of trying whether these effects cuuld not ba ' 
parried still farther^ and he made an iron cylinder 27 French 
lines high, and 18 in diameter; with a hole in the centre l£l lines 
deep, and 1| in diaraejter. It was subjected to the same experir 
Bients as the fdrmer, with a battery which had 100 sqilafe feet 
of coated surface*^ and was burst by 70 e.t plosions, 'fbeppening 
was w6ll^ cleaned after every discharge with an iron wire^ an(f watet 
let fall, into it iti drops, to remove the half fused and oxided grainai. 
of lead, and separated by th^ discharge. The c5!linder was then 
irefilted witb fresh water, th^ wires placed in the opening, and the 
apparatus placed in a box. Henley's electrometer indicated a4 
^itensity of 60® or 65° when the discharge was made. It required' 
about a quarter of an hour to charge the battery, and about ^Q 
discharges could be obtained in a day. The ^tfongest effect wa9 
produced when the fluid was 'directed to a single point. And the 
«|Bthor asks, can thet ifiterior burning of metals by the passage of 
the electrical fluid, which .some (Philosophers have long sinde con? 
sifdered as possessing acid properties, now be questioned? lie 
also states, ^hat if his experiments be repeated in vacuo with a 
• sicnple stream of the fluid, the oxided and fuliginous products ' 
%viU ,be equally obtained. This writer likewise hints at, the 
«iEett of the experiment made in water, but admits that this re* 
^ai^s farther examination. 

S. Mr. Delametfaerie thinks that the effects of electricity in 

tearing masses of so much tenacity as iron cylinders, give soipe 

j^robability to the -opinion of those German astronomers who ' 

jpiave thought that^the four new planets, Ceres, Juno, Pallas, apd 

V^sta^ are fragnient^ of a larger planet forme»-ly situated between 

•vo* 25«— TOL. YX. 2 ij 






i26 Jctknof Electricity on an Iron CytinJkf. 

^lan and Jupiter, and rent in pieces by some unknown cadM^« 
He supposes that the centre of this planet was a mass of metat 
in similar circumstanic/e;^ to the preceding cylindei-s ; and that 
either a metallic vein or some otber conducting substance, acted 
upon it in the same manner as the leaden rod, and conducted tha 
electricity from the atmosphere into the metallic mass : he asks^ 
might not » great number of such strong discharges as occur m 
thunder storfns burst this mass ilnto pieces, aOcT project the diffe- 
reat parts to a distance, like tfte snaH. piece of lead in those 
valuable experiments ? This ingenious pi^ii^sopher asserts, that 
thunder storms must produce effects on the interior of ohf 
globe more or less considerable, and refers to kis theory of the 
earth, where the subject is treated. He alscv takes occasion to 
state the theory of the action of electricity on- the isaf th^; buta» 
this theory appears to amount to no more than this viz. that 
the equilibrium of the electric fluid may be distwbed by local 
circumstances, and that the fluid will the» rush to these points 
^hich have been partially deprived of it^ in order to restore the 
the e^uilibriunl, we do not conceive that it contains any thing 
either sufficiently new or interesting, to induce us to enter iuto^ 
particulars on the present occasion. 

f 

Observations. '^Tht experiments on iron cylinders related in the 
first part of this article^ afford another striking proof of the va^l- 
power of the electric fluid when acting in considerable quantities ^ 
btit however curious, interesting, and singular, these effects may 
appear^ there is another circumstance in the second part still 
more so. What we allude to, is the account of the origin and for. 
matien of the fouc new planets, as stated by some of the German 
astronomers, and supported by the editor of the Journal de 
Physique. What real advantages these philosophers propose to 
derive from such a supposition \% not very apparent, nor can we: 
conceive any motive that could induce them to make it ; for if 
it wfere admitted that th« planet vms broken into four pieces,- 
there are still a few questions of considerable moment which it 
would be neces^sary to resolve. How did these four pieces acquire 
their spheroidal form? How did they ^d the ^ way » to tbeir 
respective orbits? What impressed upon them their respective 
orbital velocities and rotary motions I What proportioned these 
motions so exactly to their difierent distances from the suu, and 
other local circumstances, as to ensure the stability of their rela- 
tive equilibrium in the midst of so many soliciting and disturbing 
powers ? How came they to taovt so near to each other, and yet Uy 
be so distinct? It is, therefore, much more natural to suppose tha|* 
the four new placets, as well as the others, derived their existeixc* 
from the time when the whole system was created* . . .^ 



*Wi4 



Tf. r^ .. ( 327 > 



Cr ' . 



T^fi-authur of 4l!i» eesay ass^rU that two <:onditioDs are neces^ 
«aT!y» m order to sustain' tbe ring of Saturn in eq«Hlibrio about 
%l!(at planet. One of ttiese relates to the equiiibrium of its paits \ 
^fae other to its Mspension about the planet. With respect to 
tbe firitt of these he obserVes, that this equilibrium requires that 
the oioledlkB of tho-^tfurfacfeof the ring have no tendency to 
dispersion ; and thiat, supposing this surface fluid, it may maintain 
its figure in virtue of the different forces bywhii^h it is solicited. 
Without this tbe continual effort of the n>decules would end at 
■kngtb in separation, and the ring wo^ld be destroyed, like all this 
Works of nature >^faich 'have-not in themselves a cause of stability 
wifiicient to^resiftt ibe action of ^ contrary forces. He also states 
that he Imt proved, 4k ^he third bot^Ex^f the Meeaniijue C^leste^ 
rtbat this condition can only i>eful^Hed hy a rapid rotary motion 
t!^ the ring in itgiplafte and about its centre, always near that 
of the pynet. ' 4le iias likewise shown that a section .af the ring 
\rf a plane per^iendil^ilar to its plane and paseing through its 
centre, is an ellipse lengthened towards that |>oint. 

^idi respect to the second condition^ if is observed that a 

liollow sphere, and generally a>boHow ellipsoid, the exterior and 

interior surfaces of whieh are «imilar and concentric, would be 

In equtlibrio about Saturn^ whatever point of the concavity was 

4ic<:upied by the centm of tbe planet ; but this equilibrium would 

%e vei^ettnty that is, that being disturbed, it would neither tend 

to resume its primitive » state nor depart ^rther from it; the 

^slightest cause, such as the action of a satellite or of a comet, 

vrould' therefore beaofficient to <precipitaie the ellipsoid upon the 

planet; The indrfferent equilibrium which takes place for a 

lioUow. sphere enveloping Saturn, would not exi&t for a circulav 

jBone surrounding that planet; It has been shown i^ the book 

above referred to, that,' if the 'centre of the circular «ing do not 

Coincide witb that of the planet, they will repel «ach other, and 

the ring will terminate by falling upon the body of Saturn* Tha 

^a'me thing would happen whatever, were ^ht eouatitotion of the 

Hng, if it had no rotary motion \ btft if we conceive that it ia 

^lot similar in all its points, so that its centre of gravity does not 

coincide with that of its figure ; if we further suppose that it may 

4t>e endowed with a rapid rotary motion in its plane, then its cen* 

4,re of gravity would revolve about that of Saturn^ and gravitata 

Cowards that point like a satellite, with this difference, that it 

^^oiyild always Oj^ve in the interior of the |>lanet \ it would tbe/rcj. 



y 



328 JLapiace on tie Sing of Saium* 

ioTtf have a stable state of inotibn. Thus both these ce»« 
ditions concur in showing that the ring has a rapid revoking 
motion in its plane and about its own centre. The time of itft 
rotation ought to be nearly that of the revolution of a satellite 
revolving about Saturn, at the same distance with the ring, and 
ibis duration is abefut ten hours- and a half* - Dr. Herschel ha* 
confirmed this result by his observations ; bnt hoW' are these 
^observations and this theory to be reconciled' 'irith the observa- 
tions of M. Schroeter, in which some points of the ring iwire 
luminous than the rest seemed to remain a long time stationary? 
X^aplace thinks that this may be accomplished ia the fellowiii]^ 
manner : , • u 

. • The ring of Saturn is composed of many cancentric rings $ 
powerful telescopes render two of them distinctly visible^ wiiiefa 
iprradiation confounds into one with weak telescopes. •• Ilk is'«very 
probable that each of .these rings is itself (CompDsed' of many 
9thers« «o that the ring of ^aturn may be regarded at- an aasem- 
l^lage of divers concentric rings; such would be the whole 9i 
the orbits of Jupiter's saielliteSy if each left in its srack a perm»p 
sent light ; the partial rings onght to be like these •rhita^ differ 
rently inelined to the equator of . the planet : and then -their iB** 
cliaiitions and the position of their nodes would change in periods 
of greater or less length, which embrace many years ; their cen* 
tres ought likewise t6 oscillkte about that of Saturn ; all these 
circumstances would cause the apparent figure of the whole > ring 
to vary. • Their rotary motion ^ill not sensibly change that 
£gure, since it. only replaces one luniinons part by another 
i^ituated in the same place.- It 4s very probable that the pheno* 
mena observed by M« Schroeter were owing to variations of this 
kind, Ellt, if a point more or less luminous than the others^ 
§dhere to the surface of one of the partial rings^ it ought to move 
as rapidly as the ring, and to appear to> change its position in 0, 
few hours. It may be believed with great probability, that it 
was a point of this kind that Dr. Herschel observed ; and La* 
place eiurnestly requests those astronomers who are furnished with 
powerful telescopes to turn their attention* to this point. Thi 
variety .of these appearances greatly puzzled geometer^ and 
astronomers before Huygens discovered their cause : the ring at 
llrst appeared to Galilee like two small bodies adhering to the 
^lobe .€tf Saturn ; and Deseartes, who unhappily wished to ex« 
plain all things' on the principles of -to philosophy^ attributed the 
atationary appearance of these pretended satellitea to the'circum<* 
stance, that Saturn always presented the safne face to the centre 
^ his vortex.' It is now known that this conclusion is' contrary 
to the laws of universal gravitation, and this reason is sufficient 
for rejecting the explanation of Descartes, even if the cause of 
these appearance^ were not known. M. Laplace thinks tbaf^ 



.,..« 



^ Laplace on the Ring ^ Saturn* pM 

^jie immobility of Saturn's ring is not the least contrary to 
%bh grancl Iftw of nature, and he does not doubt that the ulteriof 
observations' of astronbrhers fUrhished with powerml telescopes^, 
iiill eonfirm the rMttltfir of the theory' cind the observation's of 
OOr. Herschd. ' ' ♦. . i. 



Observatkmi.^^ln the Memmres de T Acadtnne de Pa? is for the 
ywnr 1 7^79* Lapiat^ suggested 'that the -ring of SatUrii might 
^tooaist of' several divisions or separate rings ; and how, after a 
lapse of nafore than 20 years, during which period, no doubil 
!tha subject has ireqftentiy occBj>ted his attention * and tried the 
atreng'tb <>f his penetrating genius, he > sfiil retains the same 
opinioo und^ some slight modifications. But notwithstanding 
'all'the leariiingand ingenui-ty 'vrhfch this hypothesis evinces, w^ 
think that a< -series- of* accurate observations with the best 
telescopes 4s Btill necessary to its confirniation and establishment^ 
and -we' think-tfaat it maty fairly be inferred that this is also the 
authav's vojAniion'' on tbe ifubject, since he has been so earnest 
iBdkreetiDg the' ilttentibn of astronomers to this point.' Yet;> 
«a every su^^stion^of so distinguished a philosopher as Laplace^ 
fwheup £»r profenndnefti and extent of research on subjects of this 
-nature, ■-■ has * no' rivul- toio^ng \ his 'cotempdraries, deserves ' the 
closest attentS^B, ii^e hope aU who have favourable opportunities 
ier iBafeiDg the requisite observations will not withhold their 
md in deciding the question as far as it. may be practicable. 

» I • ■ • "^ : ' . * • t T.' ■ • • , 4 ' 

Memoir of the Dctermnation of the Obliquitji of the EcUptiCy tohick 

' 'results from ancient observaiiotis, £i/ AT. LAPLAef.-^-Consacn 

sance des TemSf 1811. •'■■..■ .j 

In the introduction to this essay, M. Laplace observes that 
though the successive diminution of obliquity of the ecliptic, as 
^toodexQ times are approached, may no>)7 be incontestible,^ yet we 
always^ee,"\vith extreme interest, the grandinequalities of the sys- 
»jteiu of, the VKorVd gradually, developed with time* Po|terity;''.wbic!i 
\vill l^ea^le to compare -a long ^eeries of very accurate observations 
'With the results of ^theory, will enjoy the sublime spectacle muth 
better .than we can, to whom antiquity has only transmitted 
observations that are very oflen uncertain. But as these obser* 
vationSj submitted tp a sound criiieism, are- able, from the inters 
yaJ vfhich ^^arates us from^ tbem> to diffuse great light over 
toany important elements of astronomy, they deserve the atten. 
tion of genmeXers and astronomers. ' ^ 

i^. ,Xfae author of this memoir divides it into t\yo parts ; viz, ob« 
^xvations anteiior and po.sterior to Our era. In the first of these 
e ej( amines the observations of the Chinese and Greeks, priiH* 



t 



•S^O M. Laplace on the Diminu^Hon of the Obliquity of the EcUpti^f 

t,Q the birth of Christ ; and in the last, those of the Chinese^ 
/Lrabs, and Persians, made since that epo<^h« This necessarily 
)eads him into many details, to give a perspicuous account o^ 
which would occupy much more roam than our limits will allow 
jjis to ^issigQ t9 this arjticle ; w.e sh^; thierefore, -chitefly confine 
ourselves to the results to which his enquiries have 'conducted 
him. M. Laplace has inserted herie, from his Mecaoique Celeste, 
volume iii. bpok^ .vi. chap. ]cvi. a formula, by which the obli«. 
quity of (he ecliptic for ^ very long time m^y be calculated ; and 
as few q( our readers may, perhans, possess either this volume 
of theCo;inaiss^nce|des X^i^^^* ^^ the work from whi/ch t2)e formula 
is taken^ we shall give it .a place {lere. Ju ^he foUowinig expression 
]t denot,es the nuipb.er of >e;ar^ .elapsed between 17 bO and the 
given time, and the obliquity in decimal degrees will be e^rpressed 
by 26^. 0796—3676^^6 f I— jcos. (t.43<^a446)>-103SC/^.4siu. 
j(t 99'^ J 227). Here t === r- J85j0 j(th£t tinn^ between IJbO and the 
most ancient observation on Xhis subject thaj;. ca^i he depended' 
upon, or 11 00 years before our ^ra), which ^yes the cprreitpond- 
ing obliquity of tbe ecliptif equal to :^i$^.516ll .decimal deg^es ; 
or 2(r 5V 53^^ common degrees; U is A^c^^Wy to incjrease this 
result by about 6^^ because th/e obliquijty of the eclipti.c.in J 7^ 
was greater by this quantity than that givep by the preceding 
formula ; thus 1100 year^ before the Christian ^r^..(he oblii|iiM|f 
of the ecliptic ^as £3^ 51^58^^; a result which differs only by 
^ 4f^ from that given by the most ancient observations of the 
shadow of the gnomon at the two solstices.. A m^re perfe<^ 
coincidence could not he desired; seeing the uncertainty which ac-> 
companies observations of this kind, particularly on account 
pf the penumbra which renders the shadow ill defined* 

Observations prior to our Era* 

Pbliqui (y of the . Excea of the 

pate. Otwervert. £cliptic by Ob. Obliquity by the fintoyer 

Krvaiions. Formulet. tbe sec 

^lOOCheou-Kong 23'' 54^ 2^^ ^"^ fil'' SS''^ 2^ 4/^1 

360 Pytheas . SS'' 49' 20^^ 23P W 1^ 3/ 13^" 

S50 Eratosthenes 23^ 46' SJK-' 23^ 43' t9^' ^ 

50 Liean-Hiagn 23*» 4^ 39^ 23*» 44' 4".4 V 34".6 

Observations tiau oar Era^^ 

173 ChineseObser.tS^ 41' 33" 23"* 42' 17'' i-44'*^| 

461 Tsou-chong 23^ 38/ 62"-3 24^ 39^ 53// —1' 0"r 

629 Litchoufoung 23® 40' 4"-l 23'' 38' 17// 1/ 47" 

^80 Albategnius . 23** 35' 41" 23^35' 13/' 2S" 

J 000 Ebn-Junis . 23^ 34 26" 23^ 34/ 50" —24/^ 

J279 Cochcou-king 23' 3^ 2"-4 23* 3^' 22".5 — 20'^ 

f 437 Ulugh Bey , 23^ 31' 48" 23^ 31' 5" ^^ 



a. Laplace on the Diminution of the Obliquify of the Ecliptic, ^ii 

The whole of these observations establish in an incontestibl^ 
tnanner the successive diminution of the obliquity of the ecliptic : 
their agreement with, the formula of th« M4canique Celeste leaves 
no room to doubt that this diminution arises solely from the 
attraction of the planets one upon another, and upon the sun. 
The very small differences which exist between the formulae and 
the observations being alternately positive and negative,, do not 
indicate any change' to be necessary in the values of the masses 
which have "been employed ; these values are such near ap- 
proximations, that in oriler to correct them, it will be neces- 
sary to attend to the new observations with which a series of 
ages may enrich astronomy. 



mmtmti 



Observationt.'^Whtn the construction of astronomical instru- 
ments bad made considerable progress towards its present degree 
of perfection, and observers had acquired more skill and accuracy 
in using t^eni, the successive diminution of the ecliptic in pro- 
pqrtion as modern times are iipproached became incontestably 
proved; and then it ^as inferred that this diminution would 
continue till the ecliptic coincided with the equator. But the 
vast .powers of modern analysis having been snccessfuUy directed 
to this object, it has been demonstrated that the variation in 
the obliquity of the ediptic is confined within certain limits 
which it cannot pass ; and consequently, that the prediction of 
the more early astronomers relative to the future coincidence of 
the ecliptic and equator can never be- /uliilled. Lagrange,^ 
vho directed the whole united force of his ingenuity and analy- 
tical powers to this point, shews that about ^OOO years .since 
this dimmution was nearly at the rate of 3S^^ in a century ; 
that it is at present, and will be for four hundred years to come, at 
the rate of 56" in 100 years ; and that 2000 years from this 
period it will be reduced to 49'' in a century. After the expi. 
ration of a very long period, the diminution in the obliquity 
vrill change to an increase ; but the variation will never exceed 
two degrees. The small differences which appear between the 
results obtained from observations and those given by the formula 
of Laplace, are to be attributed to errors which have entered 
into the former, and >vhich are certainly not more than might 
reasonably have been expected, when the time at which , these 
were made, and the imperfections of astronomical instruments at 
tli09«! periods, are taken into the account. 



( iS2 ) 

V 



*' . . . • '■ I 

Proposal for cmisiructmg and putting in its place f an Iron Tunnel 
under ike Bioer Thames* By Colokel Lsnkon. — Fhzl, Mag.. 
No. 147. . - 

Ix this plan proposed by Colomel Lennoo, jth^ whole tunnel is 
to be composed of a number of cast. iron frames fastened together^ 
by means of exterior and interior flanches .and «crew&. Each o& 
these frames is to be t(:n feet long, eighteen feet. wide within, and 
tweWe feet high at the side, its top being convex and having 
two feet in the middle. The proposed thickness of the metal is 
four' inches at th^ bottom and aides, and three inches at the top. 
Each frame wiJl therefore >^eigh near forty tons. The flanches 
are e^ch to be one foot broad, and four inches thick ; and the. 
screws four ipches in.diameter, with half-inch sheet lead in the 
joints, or' these may be secured by cement. The two adjoining. 
ilanches«t the bottoni are also to be- embraced with damps of 
iron, eafh twelve* inc^s )brbad,,^ix inches thick, and two. feet: 
high.^ t^^olooel Lennoa.observeS| that if the carriage of pieces 
of such ^weight ffom the foundry sEould be found, impracticable,; 
the sides, top, and bottoni might ,be cast in separate pieces,' 
with flanches to join them together ;' these joints may also be. 
89 . disposed that no two •f them should coincide. Tubes of 
a)M>ut eight inches diameter are to be placed in the interior angle 
at the bottom, with proper openings to receive the leakage water, 
which will thu6 be conveyed to one end to b^ pumped out* 

The d€i>tb of. the river at low. water being only about 30 feet, 
19 not Sufficient to Admit of such a tunnel being laid npon the 
botton) without obstructing the cdutfte of the stream or interfer- 
iug with the navigation of the river ; the first step towards ac. 
compUshing this object, would be to excavate the bed of the 
.river entirely across to about l6 feet deep, and between 60 and- 
SO feet in width, and. to render the body of this excavation as 
level and even as possible/ This being doife for the space of 
I^QQ feet or rather more ; the next thing to be d6ne is to screw 
80 of Abe iron frames constructed according tp th^ preceding. 
)Uau together ; and this '* shovid be performed on the bank of 
t)ie river rather below the level of low water, in a situation 
where the tide may have free access to it." 

"If then the ends of these 80 tunnel frames so foined be 
(when empty) close stopped with strong oak plank, and yf.eW se- 
cured so as to render them perfectly water-tight, a machine is 
Jbrthed which on the admissioft of the tide vMl float ; as may be 

S roved by the subjoined calculation, wLich for greater security . 
oes not include the covering at top. At spring, tide, therefore,, 
tbe whole may be floated to the rec[uired situation, and b^^ addi* 



r 

CoL lJtnn6n*s Propasdlfor an Iritn Turinet under the jC^m^f* SSS 

tmnal weights applied sunk in its proper place. But in case of 
any irregularity in its descent, or unevenness of the bottom pre- 
pared to receive it, bj^ removing those additional weights it will 
again become buoyant, when the necessary remedies may be ap- 
plied and obstacles removed. When once properly placed, by 
turning cocks fixed in each end it will soonfiil with water and 
be permanently bedded. 

Calculation of the weight of this tunnel in round numbers : ' 

Cast iron . . * 20,020 cubic feet • . about 4,270 tons 

Lead . ... 560 178 . 

Oak .... 200 ...... . 5 



Tons 4,453 
Water displaced 1 ,850,000 Cubic feet .... 5,16'2 



This tunnel will require to sink it more than • . 709 
Exclusive of the convexity at top Estimated at . 60 

Total . 769" 

Allien this tunoelhas been floated to its destined situation, and 
properly se^rured by anchors and cables, which should be done 
about an hour before low water, at the lowest tide, the sinking 
of it may be effected by means of two short ropes with loops at 
each end passed over each frame, and slightly secured to keep 
them in their places ;^ and a number of boats on each side with 
a sufficient quuntity of ballast so disposed as to adinit of being 
immediately hooked on to the ends of ^ese ropes, hi such a manner 
that both ends of the tunnel may sink exactly trgtther. The 
weights niay be regulated or removed at pleasure as circumstances 
may render necessary ; and the whole of the operation performed 
in the space of two hours, if all the previous arrangements be 
properly made. Or the sinking may be conveniently effected by 
letting 800 or 1000 tons of water into the tunnel : having a pro- 
per pump"fi.\etl at each extremity to pump out a sufficient quantity 
if it should be found requisite to float the tunnel again. 

This part of the tunnel is (hen supposed to occupy about 800 
feet of the middle of the^ river, and to have its upper surface 
rather below the level of the present bed " Then by piling off 
the tide from low water- mark, the ends may be completed either 
by similar frames or arches of stone or brick work, as may be 
deemed most convenient. ** It will then only remain to open a 
communication with the middle part^ by removing the oak 
planking at each end, and pumping out the water ; when by ^y« * 
iog a sufficient qnantity of ballast so as to form a roadway clear 
above the lower flanches^ an^ restoring the banks (p thtir fprxne^ 

No. 25.— VOL. Tl. 2 X 



534 ' CoL JjcnnorCs Proposal for an Jron Tunnel under the Thames. 

state, the tunnel will be immediately ready 'for use." In tb» 
execution of this project, a place should be selected close to losv 
water.nlark, of about 300 yards in length, and blocks laid su{i>- 
cient to support the whole weight, and upon which the whok 
80 frames might be screwed together. This CoL L. asserts 
should be at least 15 feet below the level of the spring tides, in 
order to secure its floating when finished. 

From the vast weight and great length of this tunnel it may 
be objected, that the power of 6'7 screws at each joining would 
be inadequate to hold the whole perfectly together ; but this Col. 
L. endeavours to obviate by the considerations, that it would 
neither be subject to any particular force at its launching, nor to 
any partial bearing on its bed : and therefore concludes, that the 
danger of accident would be small, and the strength of the whole 
sufficiently secured. He conceives that the greatest difficulty 
woultT be experienced in excavating the bed of the river to the 
required depth ; but leaves this subject to more experienced 
engin^rs. NVith respect to the expense, he states that the ma- 
teriab can be procured for about 44,0001. and estimating all 
othei: expences incurred hi the execution, the whole cost would 
be about 66,0001. * 

If it be desiied to have a foot path besides the space allowed 
for two carriages to pass, six feet more width must be allowed^ 
or the whold made 24 feet between the interior flanches. In 
this case however, this writer thinks it would be advisable to 
omit the int€frior tlanthes on the sides, and supply their places 
with plates of cast iron the whole height of the side, and thre« 
or four inches thick, extending from the middle of one frame to 
that of the next, and fastened in the same manner as the other 
joinings. This would greatly increase the strength of the tunnel^ 
and allow nearly a foot more free space within, without adding 
more than twelve or fifteen thousand pounds to the expense stated 
above. 



£>"»' 



OUercations* — Without entering into a minute discussion of 
the practicability of every part of Colonel Lennon's ])roposal, we 
,wiU venture- to state, that we apprehend there would be much 
, greater difficulty than he seems to imagine, in keeping open the 
. whole of the necessary excavation, in a proper state to receive 
.the united tube, when completed. The expence too, we believe, 
would be incomparably greater than his estimate ; and if an iron 
tunnel were ever fixed by any mea,ns, it would probably be ab- 
solutely necessary that jts separate pans should be let down 
into their places ih succession, as \Vell on account of their being 
*mare mana^aWe, as in order that, they might be placed and sup- 
"port^d in such a maoneras hot to pfodute* too great a strain on 
e^ch other. 



Mr. Watktr^s new jnetallk Tkerfh^meter. 355 

It seems somewhat extraordinary that this gentleman should 
be totally unacquainted with the steps that are now taking by the 
Thames Archway Company at Rotherhithe for the execution oi 
this project. In the course of last summer that company offered 
by advertisement considcral^le premiums for plans on 'this sub- 
ject : more than fifty were presented to thera, amongst which 
there were many in principle similar to that proposed by Colonel 
Lennon, and in our opinion, (for we inspected the whole of them,) , 
several superior to his in the mode of execution. 

The result, however, of a very cautious examination of the se* 
▼eral plans by those skilful and experienced gentlemen, Doctor 
Hutton and Mr. Jessop, was the lecommendation of one whose ' 
principle was to form certain lengths of Brick Cylinders and sink 
these lengths separately in the bed of the river, and to unite 
them under water. The excavation in this case, will be made 
in short lengths, and precedes but a short time the sinking of 
the cylinders, and of course may easily be kept open. 

Preparations for this purpose are now going on at Rotherhithe. 



Description of a Metallic Thtrmometerfor indicating the k/gher De- 
grees of' Tetnperaturc, By Richard Wa lkeji. r—iPA«/. Mag. 
No. 148. 

Mr. Walk Ell's object in contriving this new thermometer 
^as to exhibit the degrees of heat in the intermediate space be* 
tween the upper termination of the mercurial thermometer which 
ends at 6*00^, and the commencement of Wedgwood's thermometer, 
the scales of which begins at red heat, or 1077 ** of Tahrenheit ; 
and thus to form a connection between the two. The princi- 
ple of this invention Mr. W. describes in the following terms : 
*' A metallic composition is formed, not fiable to alteration in 
its quality or quantity by repeated exposure to heat, the melting 
point of which id a little below 600^ of Fahrenheit^ and its 
boiling point at 1200^. A case resembling in form the glass 
case for the ordinary thermometer, but somewhat larger, cbntains 
the metallic composition, and the scale consists in a slender 
graduated rod^ equal in height at the commencement of the scale^ 
that is, when the metallic composition is just liquid to' the top 
of the tube ; the graduated rod terminating at the bottom in a 
thin circular, flat plate, which rests or floats as it were upon the 
liquid metal, and in proportion as the latter expands and rises 
in" the tube by heat, the graduated rod is buoyed up, or raised 
above the top of the tube, passing through a perforated cover 
to the maximum, or boiling point." Both the case wh^ch 
contains th^ metal, and the graduated rod, are at present made of 
4)ipe-clay, previously prepared by being exposed to a sufficient 



536 Mr, Walker's nHo metallic Thermometer. 

degree of heat; and the scale of Mf« W/s thermometer 
is a continuation of the scaic of the mercurial tbermoineter. 
Mr. W. aho thinks that the same principle is capable of being 
extended to xanswer for the most intense heat that can be re- 
quired. The influence of the incumbent atmosphere upon the 
liquid metal within the open tube, he thinks, is too inconsideTable 
at the commencement of the scale to deserve notice, and will di- 
minish to nothing at high temperatures ; especially if the whole 
of the liquid in the thermometer be wholly, immersed in that of 
which it is required to indicate the temperature, which should 
always be the same case. 

Mr. Walker likewise thinks that a similar method might be 
employed for ascertaining the expansion of metals by heat. Tbns 
by giving a wire a spiral form for the purpose of comprising a 
considerable length in a small compass, a thermometer might be 
constructed which should be capable of exhibiting single degrees ; 
" using silver lor the lower temperatures, and platioa for the 
higher ; or employing iron wire only, up to its ultimate point of 
expansion in a solid state. 

'Observations, — As Mr. Walker has not made us acquainted 
with the constituent parts of his metallic composition, wcare not 
able to judge whether or not it possesses the requisite qualities 
which are stated at the beginning of the former of the above 
quotations. In a note he observes, " The scale of this new ther- 
mometer is an exact continuation of the scale in the mercurial 
thermometer ; the lower degrees of the former corresponding with 
or indicating like temperatures with, the vppcr degrees of the 
mercurial thermometer." 

Are we to understand Mr. W. to mean that his metallic com- 
position and mercury undergo equal expansions for cqiial tem- 
peratures at the degrees of heat answering to the lower part of 
his scale? That there is a great difference between the increase 
of the most expansive of the metals and mercury in lower tempe- 
ratures, cannot be doubted ; that of zinc to mercury below 212* 
of Fahr. being nearly as .0093 to .02; and the ratio of all the 
others which have yet been accurately determined is still greater. 
It may be concluded from analogy, that the expansion of metals 
is progressively increased with the temperature ; but whether 
in a geometrical progression, as the square of the temperature, or 
as any higher power of the same, does not yet appear to be 
clearly known unless ascertained by Mr. W. by means of his 
new thermometer. 

The great difficulty in the construction of such au instrument 
is the obtaining two fixed points, between which the scale may 
be divided ; and it does not appear that Mr. W. has discovered 
any effectual mode of obviating this difficulty. 



837 






Ort the Influence of Solar and Lunar Attraction on Clouds and T^ 
pours. Bj/ Salem Harris, Esq.-^Fiil. Mag. No. I47. ' 

Th£ author of this con).Q9uiiicalioD Ktates, that on perusing tbs 
theory of the tides, as originally laid down by Kelper and sub^ 
^quently improved by Sir Isaa9 Newton, he waa forcibly struck 
with the idea, that if the sun and moon h^ve such iufhience on 
the, waters as to raise those parts tliat are placed in the focus of 
their attraction, the effects of their influence must be still greater 
on the clouds and vapours contained in the atmospheie. This 
influence, in conjunction with the wind or in opposition to it, he 
thought might be sufBcient to produce those fi^eiquent and appa* ' 
rentiy uncertain changes which are experienced in this country; 
^nd was much surprised that he could not find this subject had 
been treated by. any philosopher. He therefore began to form a . 
journal of the weather ; noting atjeach observation the moon'a 
altitude and azimuth ; the success with which it was tittended he 
relates as. follows : *' and I bad the satisfaction of finding my 
infantide speculation so well grounded, that I observed the wea. 
ther almost invariably thick or rainy, when the wind or moon, 
being at or near the same quarter, were act'ing in conjunction ; 
the latter drawing the clouds, as I imagine, 10 her nearest point 
of the horizon, from whence the former drives .them over its 
surface ; and that it became proportionally clearer as their relative 
change of situation enabled the wind to counterpoise the moon's 
a,ttraction, and prevent those vapours from collecting." In ISO^it 
a voyage across the Atlantic, and a residencefor some months 
at Havannahy enabled «the author to extend his observations to 
the northern- limits of the trade winds, and to the torrid zone, 
both on sea and land. Mr. Harris's principal object in the 
present communication is to give an extract of a few days from 
his journal for each of those different places v/here he made 
his observations ; accompanying them with short comments 
on the nature i)f the country, the prevailing winds, or the periodic 
cal change of seasons. These extracts are : 1. From a. journal 
kept at Wandsworth, near London, in October, 1800; 2. From 
observations between Madeira and the Cape Verd islands, iti , 
March, 1309 ; 3. From a journal kept at Havannah, in Septeoi* 
bei of the same year; and 4. From his journal composed be« 
tween Bermuda and the Western Isles, in the following Novem- 
ber. The first three of these specimens are divided into six ' 
columns each, and headed as follows : l)ap oj the Month ; Time of 
the Day ; Whbd; Moon^s Jzimuth ; Moons jiltitude or Dvpre^^ 
Bum ; Observations. The last has a seventh column subjoined, 
containing the Height, of the Thcrmomeverj at the time of obse^va- . 



3SS On Solar and lamar Attraction. 

tion. Among oth^r misceilaneous observations by wbich these 
specimens, are succeeded^ Mr. 11. says that he considers the 
strength of the wind as material in his theory ; but this is a 
circumstance which did not strike him when he began his obser- 
vatiops ;'^d therefore it is not noticed in the early part of his 
journal* He also states* as his opinion, that tbe power of the 
moon's attraction in assisting or counteracting the eifect of the 
wind, diminishes in pioportion at her distance from tbe horizon 
increases. 

We shall transcribe tbe last two days from the last of Mr. 
H/s extracts, with a view of illustratpg the form of his journal. 



Bay of 
the 



Hot. 
SO, 



Time 
of Day 



Mora. 



Eten. 



£. 

moderate 



NE.byE. 
moderate 



I>ec. 



1. 



Morn. 



Eyrtiu 



mud 



N.N.E. 
modemte 



N. by E. 
moderate 



Jiimuth 



S.W. 



AUHude or 
Depreuiihi 



Observatiofu, 



45«^ Alt. 



N. ,fil^ Depr. 



S^S.W. 



N. 



fiS'^AIt* 
65^ Depr. 



tteighth «f 
Thermemm 



Fine: a fewi 6%"* SO' 
cknids Hliich 
clearing off. 

Very fine: si few] 
clouds to windward 08* 

Mncfa niii be^ 
tv.cen U p.m. of) 
the 29th and l! 
a.^m of this day:| 
the wind and moon' 
hang nearly in diet 
same point (£. by 
N.) and the latter 
on the Iiorizon. 



Very fab* bat ta- 67* 
ther cloudy* parti- 
cularly sear the 
moon* 

Fair; but cknidy 67* S0» 
in most parts of th^ 
horixon, pardciH 
larly from N. to W. 



Observatums^'^JThe circumstance mentioned by Mr. Ilarrxs, at 
the commencement of his essay, relative to his not being abl« 
to find the influence of solar and lunar attraction on the aqueous 
part of the atmosphere, iioticed by ** the philosophical world," 
is to be ascribed to his wantf of information on the subject rather 
than to any other cause. But for this his youth, (being at 
school) and the consequent want of opportunities of becoming 
acquainted with the works of the learned relative to this branch 
of natural phenomena, account sufficiently. And the mode^y 
with which he now i^ers^ a specitnen of his observations * to thi 
ftotice of the pablic is worthy of U)e youthful student of flftture. 



Ou SqIot and Lunar Attraction* 3$S^. 

whose mind is occupied with objects of utilityi and engaged in the 
pursuitof/r/i^ A— not of controversy. On this head, he observes, 
^ I do not pretend to improve, much -less to controvert, the, 
theories of those many learned and 'scientific characters who 
have written upon the nature and variation of the atmosphere;, . 
for my knowledge in every branch of philosophy is very sUgbt; 
but, 1 cannot help thinkings that a little attention to the subject 
which I have noticed, would frequently iiseist an observer of the. 
weather, in foreseeing with additional certainty an approaching, 
change ; and i offer these remarks to the public, with no other, 
view than the possibility of their being investigated, by those 
who possess the knowledge and Uisure requisite in philosophical 
studies, to the advancement ^f science, as well as to the benefit ' 
of those professions, in which a dependence is placed upon the, 
atmosphere/' 

While we thus readily ascribe to the author of thie paper. 
the merit due to his modesty, we would not withhold . from hin^ 
the praise of ingenuous confession ; as we fully agree with liio^ 
that his knowledge, at least of the subject which he has treateti^ 
*^ is very slight/' The following specimens transcribed from his 
essay, we hope will answer a double purpose.: they will 
tend to shew the ground upon which the coincidence^ betweeu his, 
opinion and ours is founded ; and we trust that, should our re>^ 
marks fall under the obser rations of Mr. H. they will also have a 
tendency to induce him to think more closely on the subject, and 
to weigh the perspicuity and accuracy of his expressions with a lit*< 
tie ntiore care before he commits them to the public in any f^turct 
communication* We can likewise assure him, that in makisg 
these remarks we are influenced by a feeling the very reverse of 
acrimony ; our only desire being to.elucidate, or rather to exhibit, 
truth. Mr. IK repnarks, ^' I observed the weather almost iava*. 
liably thick or jainy, when the wind and moon, being at or near 
the same quarter, were acting in conjunction ; the latter drawing 
the clouds, as X imagine, to her nearest point of the horisoa^ 
from whence the former drives them over its surface ; and that it 
became proportionally clearer as their relative change x)f situatioJi 
C4)abled the wind to counterpoise the moon's attraction> and 
j^event those vapuurs from coUecting/* Is not this very obscw# 
and even contradictory?^ A little reflection will induce our 
readers to 9gree w4th ua that it is* ^* Our atmosphere may tofir 
toia at times so little vapour, «• to be incapable of produeiig 
rain^, although the moon and wind were acting, ever so much ia 
onison ; but this can always be ascertained by the state of the 
barometer.'' Those, who make experiments for determining the 
quanti^ of moisture contained in the air at any given time, «ir 
conceive do not make use of a bairoraeter ^r this purpose ; but 
«|f a very difEereivt iostTMinf ntj wlu4;hi Air. H« may, perlkaps, hav^ 



3 Id On Solar And Lunar At{raciiofi. 

lleard desighated by the appellation of a hygrometer, Agdiri^ 
*^ when also the moon's altitade or depression is so great as Uf 
place her nearly in the zenith, or the nadir, her attraction cad 
of course avail but litfle, either in assisting or «ountera€ting Xh^ 
effect of the wind, from whatever point it may happen to blow i 
its power, in short, must diminish in proportion a? her distance 
from the horizon increases." Any person, however, but very mo- 
derately skilled in the resolution or decomposition of force? would 
find no difficulty in shewing that the moon's horizontal attraction 
<)iminishes, not ^^ in proportion as her distance from the horizon 
increases, but as the cosine of her altitude decreases,' 

If we reflect upon the various causes by Which the equilibrium of 
the afhiosphere is disturbed ; the great mobility doe to its flui- 
dity and its spring ; the influence which cold and heat ba^c^ upon 
its elasticity; the almost immense quantity of vapours which it 
alterpately receives and deposits, and the changes which the ro- 
tation of the earth produce in the relative velocity of its mole-*' 
cules ; we shall not be astonished at the inconstancy and variety 
of its motions, which it is extremely difficult to subject to any 
certain laws. Amongst other causes of variation, the attraction 
of the sun and moon must also be admitted. Laplace', hi his 
Systrme du hfonde^ observes that in order to arrive at the ocean 
the action of the sun and moon traverses the atmosphere, which' 
ough( consequently to experience its influence and be subjected 
to motions similar to those of the sea. From this cause result 
winds and oscillations in the barometer, of which the peridds 
are the sameas~those of the flux and reflux of the sea. But these 
winds arc inconsiderable, and almost insensible in our atmosphere, 
otherwise so much agitated : the extent of the oscillations of 
the . barometer is not a millimetre (,0393702' English inches) 
even at the equator where it is greatest. Yet as local circuni-* 
stances cofisiderably augi^ent the oscillations of the sea; they 
equally increase the oscillatio OS of thie barometer. "But the at- 
traction of the sun and moon does not ' produce either in the sea 
or 'the atmosphere, aily constant motion from east to westi those 
motions which are observed in the atmosphere between the tro- 
pjcs, under the name of trade-winds, have therefore another 
canse. The diurnal elevation and depression of the bafofiaeter 
in the torrid zdne, as observed by M. Cassan and others, and 
-Wfakb has been attributed' to the influence of solar and lunar 
attraction, has even been employed by De Lambert^ and other 
philosophers to account for' the various phenomena of the wiuds% 
&c. but notwithstanding the leariiing and ingenuity with which 
it has been supported, it appears to be wholly rifadequate for the 
the purpose. In fact, this variation has no observable relation 
to any iwiar period; consequently it cannot be produced by those 
forces which .occasion the tides, but must be wholly referred to 
meteorological causes. 



Mr,, Marrat on prime and ultimate Ratios. 341 

Mr. Cotte, some years since, published a table m tbe Journal 
fie Physique, from which it appears that the barometer has 
always a tendency to rise from the morning to the evening ; and 
that this tendency is greatest between two o'clock in tl^e after* 
ndon and nine at nig£t, when it attains its greatest elevation^ 
The difference of elevation between two o'clock and nine at night 
as g^^eraily about 'four times as great as that betV^en tWo anj^ 
nine in the morning; and is perhaps owing to the increased 
quantity of vapour in the atmosphere at that time* 

From a series of observations, accompanit^d by an explanatory 
table, published In th^ 7th volume of the Philosophical Maga-^ 
zine, it has been inferred that the sun and moon have a consi- 
derable influence on the pressure of the atmosphere ; the effect 
of which is a tendency of the atmosphere to gain weight while 
the moon is approaching to either' quarter, and to lose it again 
during tbe approach of new and full nioon. The actual change 
which, oh a mean of ten years,- has been supposed to take place 
at London, is stated at 2-lOths of an inch in the height of the 
barometer, and this occurs twice in each moon. The apparent 
influence is likewise said lo be often much greater for a consider- 
able time together. 

For a curious account of the diurnal variations of the barometer 
between the tropics, we must refer to page 15 of our second 
.volume. 



On prime and ultimate Ratios^ with their application to the first 
principles ofthefiuxionary Calculus, Bi/ Mr, W» Marrat. — 
Fhil.Mag. No. 14,9. 

Mr. M. defines ratio to be the relation which two quantities of 
tlie. sahie kind bear to each other; and observes, that the measurQ 
of a ratio is obtained by considering what part or parts one term, 
of the ratio is of the other : thus, if a and /^ denote the terms of a 

ratio, •r expresses the ratio; of which b is called the antecedent^ 

and a the consequent ; or sometimes the terms of a ratio. If these 
terms be equal, the ratio is called a ratio of equality ; if they vary^ 
the ratio may have any magnitude ; and if only one of the terms 

-vary, the measure varies with the varying term. Let -represent 

any ratio, and let a remain constant, while b is variable ; it is 
obvious, that if 6 decrease, the measure of the ratio will increase ; 
and when b is become indefinitely small, the measure of the ratio 
is then indefinitely near to a ; and when b entirely vanishes, thQ 
measure of the ratio is exactly equal to a. 

On the contrary, when b increases, the measure of the ratio 
No. 25. — Vol. ti. 2 t 



}J4l ^r* Marrat on fwne and ultimate Ratio$ 

decreases, Agaii:, U t b remain constant while a is variable ; Acn 

as a inert ases, the measure ot tlie ratio increases ; hut it decreases 

as a decreases *, and when a entirely vanishes, the nuasnrc oi th^ 

1 *r ""I" ft 
ratio is equal to-." JMr.M.tiicn assumes as an example, 

which he treats in the same manner as before; and concludes by 
observing," when x vanishes, the r^tio is equal to a exactly." 

From these illustrations Mr. M. considers it extremely obvious, 
that the measures of such ratios never can attain the limits assigned 
them, but continually approximate towards them, till they differ 
from these limits by less than any assignable difterence, and then 
they may be said to be equal. Ihus, by making use of thesera- 
tics in their ultimate stale, we obtain results indefinitely near the 
truth ; and, in practice, the indefinitely small error may be neg^ 
lecU'd without deviating froni the truth by any sensible magni- 
tude. Ihis, Mr, j\l. thiniis, was all that Newtoii meant in the 
first lemma in the Principia. Reasoning thus, he arrives at the 
following result, " that the conclusion obtained by the method 
of fluxions is not ab&olutely tnte^ nor did Newton ever consider 
them as such ; they are approximations which prodi^cc no sensible 



errors" 



The first method which the ancients employed for finding U^ 
areas of curvilinear spaces y,'m thut i)t' exhaustions. But as this 
method was often long and tedious, Cavalerius invented the me- 
thod of indivisibiei ; but these frequently led into perplexities, 
and sometimes into error. It was to avoid the tediousness of the 
foimer method, and the errors of the latter, that Newton invented 
his metliod oi prifi>e and vltimate ratios. In applying this method 
to the quadrature of all kinds of spaces, its great author supposed 
one or more ot the sides of the figure fo be in motion, and the 
figure to be generated by their extreme points. Mr. M. giv«y 
txampUs of this mode ot generation, as applied to the square and 
rectangle, by supposing them to be generated by the motion o^ 
two right lines, which are also at right angles. Thus, if.r and jf 
denote the sidts of a rectangle, aiui by the motion they become 

a . 

*-|-^> jZ+.j/ ; then the fluxion of the area of this rectangle will be 
•• .... .» 

(x + x).{y + v) — xt/, or xy-^xi/'i' .ry . I lere, by su pposiilg x and 5 

to be in a nascent state, the rectangle j:y may be neglected, with- 
out en^ibh" error-, though the result will not be strictly and geo- 
metricdlly true. 

ObiieiTations* — After perusing this essay with consielerable at^ 
tention, we are lorced to confess ourselves at a lofes to discover 
the object of its publication ; unless we regard it as an attempt X9 
elucidate the elements of the fluxionary calculus ; And in this 
aeiise, whatever may be due to the good intentions of the author^ 



Mr. Penwarne's Patent Jhr improving- Statues. 34$ 

^c certainly can neithcF congratulate him on Ms succpi^s, norad- 
■ iiait several of his conclusions. SVe l)elk;ve tb^t it is allQWc4 tiy 

■ 

must nMthematicians, that it t denott the inrasare of a ratio, and 
the denominator vanish, the measure then becomes equal to infi* 
nlty, OF - ZZQ^^ ^.nd iH>t jequ^l to a> s^ stated by ^^\ M. Agsia^ 
Wtien* <r becom<*8 nothing in the preceding expix*ssion, the measure 
ci the ratio is r =o, and not j as given abyve. In the example 

, when X vanishes, Mr. M. appears to be equally unfortu* 

aate in assigning a for the measure of the ratio iristead of oo. 

Mr. M. observes, that " the conclusions obtained by the roe- 
tiiod of fluxions are not absolutely true"* ; ^ut we would ask, is it 
not " absolutely true^" that whvn ax — X^ is a maximum, orzrja; 
or that the greatest cylinder that can be cut out of a cone is at 
^ of its altitude ? 

PATENTS. 

Jjfr.' JoiiN FeUwarnf/* Patent for a process for giving to^tut$^ 
or other ornamental H^orks, in Flatter, an appearance nearly 
resembling t/iejntst Statuary Mfirble. Dated September ISOp. 
— Repertory of Arts^ No. dS,. Second Series. 

The principle of this invention is, to impregnate the planter of 
.-which the articles are composed with a solution of alum. IlJ 
or4er to etfeci tUii^ purpose, about a pound" of alum is put int^ 
isvery three pints x)! water, and the liquid then raised to a suffi* 
ciept temperature to dissolve the alum it contains. The plaster 
cast, previously dried, and properly tinished, is then imn^erscd 
iu the solution, andsutfered to roiuiia from 13 minutes to baU' aa 
tour; afier which it is tLikeu out, and suspcuKled over the vessel 
containing the solution. It is then suffered to coo) for a fevf 
minutes, and some^ of thq solution is applied to it by' means of s» 
spunge, or linen cloth ; and the operation continued, till the 
alum'' forms a fine crystallization over its surface, of a proper 
thickness ; and then brought to a polish by means„of sand-paper 
^r glass-paper ; and then finished by rubbing with a fine Imea 
irloth, slightly moistened with clean water. Tluj patentee makes 
use of wooden vats, heated by steain, for preparing his liquor, to 
^yoid the tinge which most metallic vessels would impart to it. . 

Mr. P. remarks, in his obsef vations, that he " has the satisfac- 
tion of submitting to the inspection of the public, at his ware- 
iousc,, No. I2f Pickett-street, TemplcTbar, a beautiful imitatioii 

' 2 y 2 



]3M Mr» Groves* s Patent for an improved construction ofBuilMngs* 

of statuary marble, in busts, statues, &c. after the most oele-r 
brated ancient and modem masters :"' that this preparation pos- 
sesses ^^ the beautiful whiteness and transparency of the finest 
statuary marble, at the same time scarcely yielding to it ia 
hardness, and (for purposes of internal decoration) in durability. 
It is jiot affected by the moisture of the dampest apartments ; and 
is even less liable to soil, and as easily cleaned as marble. By 
means of this invention, exact copies of the works of ancient and 
modern sculptors may be obtained, at a price i^ot much exceed- 
ing that of plaster." 

■ »■ ■■ ■ 

Observatwns. — The plaster cast affords a facility of obtaining 
cheap and correct copies of the most valued labours of the sta- 
tuary, which is unequalled by any other ; but its colour, softr 
ncss, and liability to soil, were circumstances that greatly dimir 
nished its value. The method proposed by Mr. P. appears well 
adapted to counteract these effects in a great degree, by adding to 
both the beauty and durability of the statues which are subjected 
to it ; while its cheapness and simpHcity are further jecommen^ 
dations in favour of its adoption. 



Mr. John Thomas Groves'* Patent for antmproved mode of 
constructing Buildings, by which great expenccy labour^ and time 

: ' are saved, and the Building secured from the dry rot, wth other 
advantages. Dated April 1^9^— Rep, of Arts, iVo.98. SecSeries^ 

Mr. Groves commences his specification in the usual way, by 
declaring that his '< said invention is fuHy described in the draw- 
ings hereunto annexed, and the following -description thereof.* 
The drawings consist of fourteen figures, each accompanied 'by a 
descriptive sentence; and to these figures we are under the neces- 
sity of referring our readers ; as no information on the subject can 
certainly bo obtained independent of them ; arid those who learn 
any thing from them will accomplish what w^e have not been able 
to do. We transcribe the two following sentences as a specimen 
of the manner in which the title of the si)ecification and the decla- 
ration at its beginning is fulfilled. 

" Fig. 1: Plan of an internal wall, nine inches thick, shewing 
the. apertures for air. > 

" Fig. 2. Plan of an internal wall, nine inches thick, shewing 
the aperfures for air within the thickness of the floor ; a, apertures 
either six or nine inches high." 

These sentences are multiplied till they equal the number o^ 
figures, that is to 14; but each is expressed in the very same 
words, with the exception of those words which indicate the dif- 
ferent thicknesses of the walls, and that of external being written 
'■ for mtcrnal in some, places. Thus ends the specification ! 



Jfr* Goddar^s Patent for a method of making Chip Soxe$. S4S 

Observations^ — ^Mhen we first read tte title of Mr. Groves's 
{»atent on the wrapper of the Repertory, we were induced to ex** 
pcct that its specification would describe an invention of consider- 
able public utility ; but on opening the l?ook,' we were soon con- 
evinced, that our expectations were much too high, as we found 
nothing described that has any connection with the title. But as 
•Mr. G. has declared that his invention is fully described in his 
specification, and as we have not the least reason for impeaching 
"his veracity, we can only conclude that his inventiony and the 
title of this specification, have not that connection with each other 
which should necessarily subsist. 

We are sorry that our duty again compels us torerert to the 
principle, that the law, which places in the crown the power of 
granting letters patent, as an incitement to the exertions of genius, 
and the public reVard of these exertions when successful,' require* 
that the specification" upon which the patent-right is granted siialt 
describe whatever the title imports, in such a perspicuous and . 
tninute manner, that any competent but common workman may 
execute the design without employing any invention of his own, 
and without any further instruction being necessary than that 
'which the specification furnishes. We, however, who are much, 
accustomed to the contemplation of such things, even were wo 
able to handle the requisite tools, certainly could not construct 
;such a building as the title implies, without further information 
'than is given in the specification ; and therefore think it fair to 
conclude, that no common workman will be found who can. 



Mr. James Goddakd'* Patent for manufacturing a certain de^ 
serif tion of Wooden Boxes, called Chip or Pill Boxes, Dated 
Januarif IS09' — Repertory of Arts, No, QS. Second Series. 

The machinery which constitutes this invention consists of 
several parts, arid is adapted to the purpose of cutting wood into 
chips, veneers, or thin plates or boards, for making boxes, and 
other uses. In this apparatus, a strong frame of wood, or other 
fit materials, supports a moveable piece called the carriage, which 
is moved very" steadily along grooves made in the frame ; and 

- ivhich, on account of both strength and precision, the patentee 
prefers being made of metal. This carriage carries along the 

' knife or cutter, which is made of plate steel, having the edge 

"bevelled on the side farthest from the wood intended to be cut; 
and the line oi' the edge is inclined to that in which it is moved by 

' the carriage (while cutting) in an angle of about 30^ ; which th« 
patentee states, from experience, to be the most useful or best 

" jadaptcd to the required purpose, though the chips may be cut 
Very well with other angles considerably diflferent from this,. Tha 



^4f$ Mr. GoddariTs^ Patent fen- a method qJ mailng CU^ Boxti. 

4rst mentioned horizontal frame also supports a metallic platfoxm 
upon which the wood to be cut is fixed ; and in which a groove if 
Hi^ide, wherein the lowest part of the cuUing-knife moves, and is 
firmly supported, so as to prevent any side nioti^m or shake in the 
$ame. The carriai^e, also, supports a moveable gauge or cutter, 
which cuts cross-wise with respect to the knife, and cuts a line ia 
the face of the wood, which is afterwards shaved off by the knife ; 
by which means the shaving is separated into two or more* pieces 
of the breadth required. The carriage is moved by means of a 
fkmn or strap fixed to it, and to the axle of a wbeel turiuBd by 
winch handles. > 

When the apparatus is to be used, the carriage, with its cvtter 
/Mid gauge, is moved to one end of the frii,me, and tbe wood, being 
£rst properly shaped, is fixed on the platfopm, with its face a 
Iktiie beyond the groove in which the cutter laoves, and is kept ia 
this position by means of screws. The first molion of the cutter 
j»long the platform takes off a slice or shaving, and prepares the 
wood for its future operation. The carriage is then moved bacl^ 
mid the handle by which the screws that regulate the thickness^ ojf 
, ilfae slice to be cut are moved, is turned one or more turns, as^ th^ 
thickness requires ; and the carriage being again brought foiiwardt 
now takes off a shaving orUniform thickneps^ and proportioned to 
^e motion of the. screws. Proceeding in the same manner, tlu9 
-whole of the piece, except a thin portion, may be cut ; and seyiCr 
val of these remains may then be glued together, and cutix^t^ sha^ 
ings.as before, if required. 

Mr. G. also describes a tool for cutting out the tops and hot* 
tems of b^xes, or for other similar uses. But he, in general,, per- 
forms this part of the business by means of a seat and cutting 
launch, worked by a fly-press, in the same manner as lyetat^c 
blanks eire cut out for coins, buttons, and other similar works. 
The pieces are cut. into lengths by gauges, and glued upon cylin- 
ders or blocks in the usual way ; and put to dry in cellsor frames 
which do not require any particular description. 

Observations. — Pcifhaps some of our readers may, at first, (Jiink 
the manufacturing of chip boxes is of too trifling a nature to hav;e 
merited the distinction of a patent ; but when the vast numbers of 
them which are daily used, and therefore the necessity of having 
them afforded as cheep as possible, are taken into, the acco\int, we 
think that any contrivance tending to facilitate this species of 
manufacture deserves encouragement; especially atajtime when 
it has been impossible ,to procure the usual supply ^rom theconti-^ 
nent. The present machinery appears to be well adapted to the 
• purpose for which it was intended ; and easily suited to the nature 
.43f the work to be performed, or to be accommodated to ^he local 
cifcumstanccs^ of the situation. - 



( 34?» 

Iff. William Dockbey's Patent for considerable hnproretPtnU 
in tJie process of moMLfacturing Ivory Black; andforjruherudvg 
^U articles capable •fa more easy separation of' thir parts or 
q»nstituent principles. Dated May ISlO^—Uepcrtoiy ^Artsi 
No, SQ, Second Series, 

TrU in<ventu>n of Mr. Docksey consi^ in rrd lining ih« sel^rrt 
ftrtkles to a fine powder, without the use of those Coasiderabi^ 
qvanttties of water that are now employed. For the manufactuiv 
<if ivory black, he takes .the bones and the Sfloughs of the bams of 
Animals, tLnd calcines them to blackness in air-tt^ht vesselfii 
They are then crushed in their dry state between metal rollers^ 
t^\ they are sufficiently broken to pass through a hopper into th^ 
eye of a mill-stone, by which they are reduced to a fine powder iii 
the same manner as com is reduced to flour. The powder thutf 
obtained is then passed through a dressing machine cohstmcted 
with brushes in the usual way, the meshes of which are aboul 
«ixty^ight to an inch ; the part which passes through is fit fo# 
use, and is damped down with a dmall quantity of wat^r (br sale % 
liie remainder is returned to the hopper and ground again* 
- With respect to flints, potters clay, colouring and glazing 
materials, this patentee pfl<)ses them in a dry or calcined state^ 
linder stampers or heavy hatnmc'rs, till they are sufficiently reduced 
in size to press between metal rollers, after which they undergo 
th« same process of grinding* "and dressing as in the former caeej 
The powder which ha» passed through the dreijsing machine i# 
then mixed with water in, a deep vessel ; by which means the 
coarser parts are again st^parated by subsidence ; the thinner parts 
ef the mixture are then passed thr^mgh a fine lawn or cypres^ 
meve; after which fhe wat^r i« dhiined off, ^ and evaporated by 
beat from the substance ; and the ' powder thus obtained is «f 

superior fiiieneas.' 

— ^ I 

06*pnwifwtt«,-r-This method of manufacturing ivory black* it 
-certainly calculated to save a grieat d*al of the time, labour, and 
cxpence, which -were neeiessary in the processes • previo«sly 
Adopted for the same purpose ; and We think^ with the patentee, 
thst the "Colour will -be better preserved. His mode of separating 
the finer parts of the pulverized eolburinjg or glazing materiak 
-will also bee^ctual-; and the fineness of the powder must^contn« 
iMite to the jdelicacy and beauty of our porcelain manitfactura^ 
-£lut in order tO'eBtiinate the precise value of Mr* Docksey s invent 
tion^ it would be necpsaary to compare it more acctimtely witht 
<lie modeahitbert* employed than we bay« leisvrt to ile tifeprewii»« 



( i4s ) 



mssm 



Mr. low Craig e'j Patent for an imyrofccd Kitcken Tlre-^tace^ 
Dated Febrvary 1 810. — Rep. of Arts, No. 98. Sec. Series. 

Mr. Craige's " invention consists in the application of tb« 
powers of an air furnace to give heat externally, and in using 
tond, iron, or other dense bodies, to receive and retain such heat, 
to be employed for various useful purposes*" To effect this on a 
small scale, a base of stone or brick work is to be constructed, 
about four fc^t long, two feet eight ificbes broad, and twetity 
inches high ; the chimney grate, about eighteen inches wide, and 
six deep, is to be fixed near one end of the front. On this founda« 
tion two sides of artone or brick are to be raised, about nineteen, 
inches from each other, and extending through its whole length ; 
these sides are covered with a pan of cast iron, resting upon rims 
placed upon the sides, which raise the pan aboyt half an inch 
«bove them. The depth of the pan is to be about six inches, 
'' and will be raised above the basis, so as to leave An aperture 
throughout of about an inch and a half/' This aperture te.r|ni- 
nates at the end opposite to that which contains the firergratef in 
A flew leading to the chimney, which should be furnished with a 
damper. A plate, projecting from the lower end of the .pan,. 
iforms the top of the fire^place^; its back and side» are.mad^ of 
brick-work. The door on the front of the fire-place is to.be:about 
.eighteen inches wide and sixteen deep; extending about . four 
inches below the grate in front of the ash-pit ; a grate of about 
five or six inches high is placed in front of the fire-pla^e ; and ar 
^mall door, three inches wide and two deep, opens in the large 
door, to admit air through the ash-pit when this last is shut. If 
wood be used for fuel, the depth of the Ere-place must be increased* 

The following are the purposes to which the patentee proposes 
this improved fire-place to be applied : viz. *' The iron pan being 
filled with dry sand will form a sand bath, with heat sufficient 
According to the depth to which the vessel is placed in for all 
ordinary purposes, and bein^ once .hea^d will retain >he heat 
for considerable time; especially if the doors are kept close shut; 
the plate or front will serve for broiling or frying ; roa9ting nuiy 
be performed to perfection before the door in front, even with th^ 
doors shut ; an oven for baking may be fixed at the flue.'' In 9ome; 
observations by which the specification . is succeeded ,.in thet . 
Repertory, the patentee states the saving of fuel to be full two 
thirds of the quantity now generally used. 

Observations. — As Mr. Craige's specification is not accompanied 
with any illustrative engraving, it is not easy be understand 
the construction of his improved kitchen fire*pjace, nof to ascer^ 
tain its fitness for the intended purpose ; but if it will efiect what 
be asserts, viz. a saving of two thirds of the fuel generally osed^ 
it is certainly worthy of adoption in various parts of this countr j 



Mr.Witt^i fatentfcr'eert'impwrhf^rotatiocSie^ 341 

where fuel is so expensive ; aiul particlarly in the metropolis and 
its vipinity. . i 



Jfr. Richard Wit^ty's Patent for making, arranging, and com" 
bimag certain Farts of rotatvoe Steam Engines, by uhich m eons 
the most complex Farts of the Steam Engines now in use are dis^ 
ptnsed with. Dated Feb. ISlO.^^Repertory of Arts, No. 99^ 
Second Series, ' ^ 

Mr. Witty states that his inveDtion consists in making, 
arranging, and combining the reciprocating rectilinear motioa 
with the rotative in such a manner that his steam cylinders, with 
pistons moving in them .in a rectilineal direction, do at the same 
tame turn upon a horizontal axle or shaft, and partly from .what 
is commonly called the fly*. wheel. By this combination of the 
cylinders upon or in a vertical wheel, he effects a complete 
rotative engine, with pistons moving in straight lines in their 
cylinders without interposing a beam, crank, or other contrivance 
between the rectilineal and the rotative, as in the engines now in 
use ; and which engine, thus combined, performs the filling and 
discharging itself in a superior manner without the aid of valves 
or cocks, consequently the gear, denominated the hand gear, is 
also rendered u^dtaectssary. Mr. W* then shews in what respect 
his invention differs from the rotative steam-engines without 
Veam, crank, &c. made by others. In these last the pistons 
have been made to revolve about a centre ; but in the present 
invention the pistons do not move round a common or concen* 
trie axiS) but in straight lines, like those of a common beam 
^gine, and are at the same time with their cylinders carried 
round upon or in a vertical wheel, which operates as a regulating ^ 
fly-wheel. By this means the pistous acquire a compound mo- 
tion, and describe a curve, varying with the length of the stroke 
and the speed of the engine. 

The patentee describes several varieties in the manner of 
esffecting this, of which the following is one t Pour c^^linders are 
£xed, at right angles to each other, to a hollow nave or axle, by 
laueans of screw bolts ; and the pistons working in those cylin- 
ders are made tight at the extreme ends of the cylinders with 
common packing. Each pair of these pistons is connected 
* together by reciprocatmg rods, which not only unite their forces, 
'km are of essential service in opposing the centrifugal forces to 
each other. These pistons, thus connected together in pairs, 
must be made of such a weight that a vacuum in' one of the 
cylinders may easUy raise them both together in a perpendicular 
^iirection. An axle, which is fixed horizontally is ground dr* 
tight into the hollow nave, like the key of a cock, with two ducts 
or tubes in it ; tine of these tubes is placed at the upper side of 
the. axle, and is coimected with the steam pipe; the other is 

no. 25.— VOL, VI. 2 is 



J4C Mr. Hltt/sFUimf/arcertlMpartiofroffetkeSte'j^E^inetk 

HxmI on the oftposlite side, knd joined to the pi)»e that leads to Ul» 
condenser. Each cylinder is made to communicate thrOugbL 
the hollow shaft where the two ducts in the iix^ axle (which , 
resemble two water ways in a cock) correspond with each other ; 
and, at feach half revolution, the holes in the bottom of the 
cylinders open alternately into these two ducts-. The hollow 
shaft must be rtiade of sufeci^tit length on each sirfe of the wheel 
to admit cff being supported ift brasses and of the application of 
mill-work. The cylinders and pistons being thuis arranged, and 
One pair of them being nearly in a vertical position, if the sleani^ 
be admitted into the upper cylinder, by the proper dact, its ex- 
pansive force will raise this pair of pistons, and destroy the 
equilibrium of the wheel, which will be caused to resolve by 
means of their gravity. In revolving each of the cylhifdefs will* 
be filled with steam from the upper duct, and discharged when 
th^y descend to the lower one. Thus, affcier th« cylinder has 
cleared itself of air at the commencement of its operation, whicte 
may be done in the snme way as with others, the lower cylinder 
will always be under a vacuum, while the upper one connected 
v^ith it will be receiving steam from tfie boiler. Hence the j)is* 
tons will evidently be constantly receding from the centre otf 
one side of the wheel, and approaching the centre on the other. 
With respect to the discharging duct, the patentee observes, ^ I 
make the duct of such a size or capacity, that the cylinders pas* 
it before the pistons are brought home ; so that part of the tie* 
condensed fluid is left in the cylinder^ andy by being pent up by 
the momentum, it returns the impetus as ^oon as the opposite 
cylinder empties itself into the condenser, and this elastic fluid i» 
discharged again into the steam duct, and adds tb the common' 
stock of Steam in the boiler. By making use of this uucoudensed- 
fluid in the manner just described, the motion of the engine is there- 
by made perfectly smooth and easy, and the momentum of the pis- 
tons is employed (if 1 may be allowed the expression) in bolting 
up power, which is thrown into the rotative continuous motion. 

Some other varieties in the mode of obtaining the same object 
are described by the patentee ; one of which is, that of diakin^ 
the cylinders moveable instead of the pistons. The engine i& 
also m(*de to have double effect or power by connecting the 
extreme end of one cylinder with the end of the opposite which 
ift nearest the centre or shaft by means of a pipe, and causing thfe 
piston rods to work through stuffing boxes. But for further 
particulars we must refer to the specification and the pfates by 
Which it is accompanied. 

'the patentee states, in his observations, that it is from actualr 
experioiei^t that he is induced to prefer the invention described in 
the preceding specification, chiefly on account of its siniplicity 
ahd e«kSe of construction ; also that he had found that ^istooe. 



mom Vfi^ gvf^ifur fgc^ty, m^ xmjcb ^t^r, m b ^tr^igjit Im 
tli^n in ftpy fyttmr direction. . He likwie* poA<jews that by thi# 
jsoAite of hai^ging ibe cylinder* upon tte . fli^'^hfi«l, bi» eagipp 
4[j!Qsse9s^ iM 4497fLiit.ftge9 /9f both tb^ r/ectjijin/^ tg^ci rp^^uv^ 
ienginesy and approacbes towards a mhifiitm .of tbie .4i)99<iy0Dt4g^ 
jpfeacb. 



Tr 



. Ob9fi/w^ti<m.'^A eMrsory pery9fkl of tbi» l^ticl$ viU ^vioice ibal; 
Air. W* dQ#» QO.t (mnd hia dai/s tp A^^velty, like mw» patentff^, 
on tbe innovation of fixed principles; bujt 9olely op «9ikkipg Mui 
arranging those parts of bis engine which we have described ; and 
for combining the principles of rectilineal with those of rotary 
potion. . ,0n this bead he asserts, |.h^ he b4§ ^' fprju^d and 
jnade ^ coinpietef simple, and effect^ vis ei^^ini^ or engines/ by 
which the pow^f obtained frpija steam, both l?y expansign j^nd 
/eondensatioby is communicated tp mapbinf ry^ &|e. ^t a compara* 
iively small expence, and, with some advantage in the saving of 
#id.'^ -One circumstance which we regard as favourable to this 

Ertentee's invention, is that his theory appears to have been con- 
med by practice; and an engine of the kind for which tiie 
ftt%e^ was obtained actuafly constructed and at work : and wp 
'imagine that the principle can scarcely ever be' extepded to 
'^inechines of great power ; the weight of the cylinders to be 
my»wi^ and the inequality of the wear of the pistons feeing likely 
"to-be very serious objections. 
* -- ' * 

'jBtr. James Hall's Bttteni for n^aldfig S^v^rs apd Pmtley Wheeb 
f ifEarthi and Minerals, Dtfted November^ 1 HQ^.r^Repi^rtqfv ff 
i Arte. No. }'00. Second Series. •' 

T6e ipaterials used by Mr. Pall ii? foxifjipf^ W? cprnpositin?^ 
*j^re ,cjay or earth th^t contains ^i^ls^ou^, witceous, calicar^9ju#, 
land niagnesian earth, powdered calciue4 i^^on ^!^Q^Cf afi^ pul* 
yerised g^ranite^ or any vitrifiabJe ^tJom, ^vbetb9r jcalcjin^d or not, 
Tbjs' mixture IS to be madp in^Q a p^^t^ wi.tb watejf^ mi ^tof 
^jBJng blended together and tempered into ^p^^s, tp be wwd intp 
fii^ required %rtic]e by ^jjeapg of ^ nwiJd, qx any other method 
^m^loyed 19 jn^king earthen ware ; apid the^ to V baited or ftred 
IP a common poitter's oven, jtill it becpfae sufficiently .firn> ^nd 
jp.ar^ fof fti& intended purpose* Different article^ requir/e diigsrf^t 
'degrees of heat, which an experience*} workman villj^^adily ^^ply ; 
3nd various proportions of the , above mentioned ingredients may 
fji^q h$ j^sed. Ppc of these compositions conpi§ts of seven parts 
pf day, two jpart* of calcined iron ore, and two parts 0/ granite ; 
jQr t\yp pj^rtf of Corneal] stone, or any other vitrifiable eartji naa/ 
■J^ ^u^bstjtuied for this Jalter. Other proportions ire thirty par^ 
it^fajr^ Wi^ twenty parts of calcined iron 'ore, and two of Corni* 



544 Mr.WWmHi^s taUM for Tmprdtmenii m C^^ 

vail stone. Many differtnt metallic ores and oxyds may-lMi 
used instead of the iron ore, and mixed-wiih any stones of the 
kind mentioned above, or with those which contain manganese^ 
and the composition will acquire sufficient hardness for the re* 
quired articles by baking. 

Obseroations.'^There can be doubt hut that Mr. Hall's coropo^ 
sition may be rendered sufficiently hard for the intended purposes, 
yet we apprehend there must be some difficulty in giving it 
the requisite truth of figure. 



P 



Mr. JoHir Williams's Patent for certmn Apparatus tobe appUed 
tOf and used wth^ IVheel Carriages^ in ardir to render the sam 
more safe and commodious, Datec^ fvne^ 1810.— jReper/ory ^ 
Arfs^ No. 100. Second Series. 

I 

This apparatus Mr. Williams denomios^ a preserver ; it emir 
^ists of (wp branphesy the fpretnost of which is made longer tha^ 
the other, anfi ^eir Ipwer extremities lie nearly in the plane oif 
the wheel, Tbe%e branches are connected together by a strengtbeqr 
ing piece, and unite in a ^pket at the top, whi^h contains a hole 
for ^ pin, bolt, pr screw* A proper spiiupe is. oqade fast to the 
<|kxl0-»tre^, and yrhen t)ie preserve^r is in its place, is passed throogli 
the secketf and fixed by a bolt or screw. A pair of these pres^r^ 
ers is to be applied to a two-wheeled carriage ; one near each ex- 
-tremity of the axle»tree. ^ The effect of my said apparlttus, or 
l^dditional pi^rUf, is po preyei^t the great danger iq fi t^q^v^^f^ 
carriage, when, by a fall pf the horse, or any part givifig way» 
the body might be thrown /orward or backward by a motion on 
ih^ axis ; for i|: is the pianifjpst effect of nay said apparatus to rmm 
ceive and support ^he carriage nearly in the horizontal positioiiy 
'without the possibility of any considerable tilt or inclination, ei« 
ther forwards or backwards/' 

This apparatus noay likewise be applied to four-wheeled canit- 
ages for liie purposes of preventing accidents, when a wheel either 
comes off, or is incapable of affording the adequate snpport to tbp 
carriage. Spindles are to be fixed to the axle-trees as before, hat 
below theni instead of above ; apd the brace of the two arms oj: 
branches is to be curved at the bottom, by which means it .actit 
ivhen brought into motion, as a sledge, upon which the ci^iagQ 
will he supported and suffered to move. 

Observaiions.'^The great number of accidents which h^ppezi 
from carriages of the description, for which .these preserv^ 
ers are intended, renders any invention that tends to prevent 
|bexii^ of considerable public importance ; and we think expenencc^^ 



Mr. C(mgreoe*s Fatadfor a Scuriti^ agamit Fhe. 941 

i^l prove that this is not ill adapted for the intended purpose. 
In some observations published on the wrapper of the Repertory, 
Mr. W. recommends, that these preservers be made of well tem^ 
pered steel, which will admit of their being made strong, light, 
and somewhat elastic. They need not be made to we'igh mor^ 
than 30lbs«, per pair, and may be removed at pleasure to any 
axle-tree now in common use by any competent workman. Their 
situation also renders them serviceable in preventing the frequency 
of overturns in light carriages, by diminishing the distance be- 
tween the road and the centre of gravity of the carriage. 



m 



ilr. William Concreve's Pa^enf ^br a Mode of Comtructiou 
qr Arrangement /or any Building so at to cfford Security against 

^ Fire, with other Advantages. Dated February , I8O9. — Reper-^ 
tory of Arts, No. 100. Second Series,. 

- Mr. Congrrve specifies the did^rent parts of his invention in the 
following terms: ^' First, This invention cempreheiids a fire^alarum 
^bich in case of fire breaking out, shall ipstantly give the alarni, 
and ai the same time indicate the precise part oftkt home in which 
the mischief has arisen. Secondly, It comprehends ah apparatus 
for extioguifthing ^re^ which shall be called into action by the 
£r# itself at its 4tst breaking out, and which shall be brought to 
bear upon the precise p^rt where the fiames exist. Thirdly, The 
means of extinction niay be applied in conjunction with the alarm 
or without it. Fourthly, The meaps pf eytinption may be either 
external or in ternaL All which varieties of the combination may 
)>e applied according to the convenience and necessity of the case/' 

In dwelling-houses, where saving of expence may be an object, 
ft good security would be afforded by the fire alarm alone, and 
ifithout prpvifling any particular means of extinction. In large 
bui