NOTICES AND ABSTRACTS 
OF 
MISCELLANEOUS COMMUNICATIONS TO THE SECTIONS. 
MATHEMATICS AND PHYSICS. 
MATHEMATICS. 
Page 
Rev. Dr. Brycr’s Account of a Treatise on Arithmetic in the Chinese Lan- 
guage, by the Rev. Dr. Moncrierr, late of St. Paul’s College, Hong Kong 1 
Mr. W. GarTLAND on Criteria for real and imaginary Roots of Biquadratic 
MUGUALIONS) asseancccsceseaneeasotincrsencdset bagabotsid ctiseendecpacon sobm onde oar acenneriaoe 2 
Sir WILLIAM R. HAMILTON on Biquaternions ........-.sscesseseeecscneceeeveneenees 2 
J. J. WATERSTON on the Gradient of Density in Saturated Vapours, and its 
Development as a Physical Relation between Bodies of definite Chemical 
Constitution .....ceeee Recidahantae ata ae aig treeh ls cons senestae Masten «aetawcke hivrtes 
Lieut, Heat, Evectriciry, MAGNETISM. 
Sir Davip Brewster’s Notice of a Tree struck by Lightning in Clandeboye 






FISTS ceaeGeoSiGobiboce coke BR UnGoL NBDE CAI GoLE Dob ricca non ARoHeeT bof ts, IeSpRbE Enea tae to ae ace CEIAE 2 
———— Account of a Case of Vision without Retina ............ 3 
——_—_—_—_—— —— On the Form of Images produced by Lenses and 
PeieMgns OL Hit ereMe SIZESl gece casera s-ceccicccessccerecthceitasdesrsseaststietocaeeesoeees 3 
Mr. A. CLAuDET on the Stereoscopometer.........ssseseecseeerees Senpecbcrsagents) i 
; on a Manifold Binocular Camera ..........csseecesscneeneens wiht 0 
Professor Marrrucci on the Laws of Magnetism and Diamagnetism, in a 
Letter to Dr. Faraday...... SHSaSEReE Reeas esi asnci vent aeens arsenic “acaente asst eeag 6 
Captain E. J. Jounson on placing Compasses on Board Iron Ships ......,..... 10 
Professor PowEL. on a peculiarity of Vision ...........++ eMac Spel etealchs dee 11 
————— on Luminous beams .............sseeeeeeeene ehiibabeneannteditaiat 11 
—_—__——_ on Converging Sum-beams: ...0c..0.scssecssedesccsvecsvenssscuers 12 
Mr. W. J. Macavorn RANKINE on the Re-concentration of the Mechanical 
Biter eg On thes Umi versete, cade caceasicdescar ss =psjarsasaniedishapioasqeeahiupmyennsegenacgy ech 12 
Professor C. Piazz1 SMyTH on an Improved Form of Reflecting Instrument 
BEM SCY At SOA ate vedslancscecdeReneaatee anced sateonytelecsastancassusesdscscentgaveuecesess 12 
——_——————— Remarks on the Red Prominences seen during 
_ the Total Solar Eclipse .............c.s00e plesins robin acto sie lee abieeaanmay ts «Saapgene del 13 
Professor Strokes on the Optical Properties of a recently discovered Salt of 
Quinine. .....6,...0.sc0 ee ea ne Lea spaodvan hassel Seconancgmngtone scents tes 15 
Mr. J. P. JouLE and Professor W. THomson on the Thermal Effects of Air 
Pushing through smallsAperiures ysiseesil. ce eaaes We evadetcacsedawecieetss seeeee 16 
Professor W. Tuomson on the Sources of Heat generated by the Galvanic 
ALLER V2 vuctascentriclavs'(Sers ves dtniaeens omeiblerseveln ee snus creer teeae Wr eswitwiunineesewes 16: 

