TO CORRESPONDENTS, 
The Communications from Mr. Bevertry, Mr. Burns, and Mr. Moserey, will 
be -inserted probably in the next Number. 
J. Ns Demonstration “ that no part of a circle is a straight line” is ingenious 
and successful ; but this truth may be allowed to rest upon the terms of the defini- 
tion of a circle, of a curve, and a right line. 
Mr. Dition’s paper is not intended for insertion. 
Mr. MacLeay’s register of the Thermometer at Wick, in the North of 
Scotland, for last year, has been received.—Also, two Communications from 
Mr. MErkxe. 
eee 
PHARMACOPGIA LONDINENSIS, 
Iterum recognita et retractata, 1824, p. 6. 
«“ ACIDUM ACETICUM FORTIUS,” 
vel 
«“ Acidum Aceticum @ Ligno destillatum.” 
URE CONCENTRATED ACETIC ACID, agreeable to the Sample 
furnished at the request of the Committee of the Royal College of 
Physicians, may be had of the Manufacturers, BEAUFOY & CO. Sout 
Lambeth, London, 
4 
ENGRAVINGS IN THE PHILOSOPHICAL MAGAZINE, 
illustrative of the following Subjects: 
Vol. LIII. 1. Dr. Ure’s Experiments on Caloric, Mr. Luckcocx’s 
Paper on the Atomic Philosophy, and Mr. Botron’s on the Purification 
of Coal Gas.—2. Mr. Rennie’s Apparatus employed in his Experiments 
on the Strength of Materials; and the Marquis R1poLrut’s Improvement 
on the Gas Blowpipe—3. Mr. Merxxe’s Paper on Calorific Radiation ; 
Mr. Lowe's on the Purification of Coal Gas ; and Mr, Huegurs’s on ascér- 
taining Distances,—4. Dr. OLInTHUs Grecory’s Paper on the different 
Rates of PennincTon’s Astronomical Clock at the Island of Balta, and at 
Woolwich Common, 
Vol. LIV. 1. Menai Bridge.—2. Mr. Lowe's Mercurial Pendulum.— 
$. Mr. Hare’s Calorimotor, a new Galvanic Instrument.—4. Capt. Sa- 
BINE’S Illustration of Irregularities observed in the Direction of the 
Compass Needles of the Isabella and Alexander; and Mr. Scoressy’s 
Anomaly in the Variation of the Magnetic Needle. 
Vol. LV. 1. Comet’s Path of July 1819.—2. Annular Eclipse of the Sun, 
Sept. 7.—3. Mr. Lane's Instrument for gathering Fruit; Mr. Youne’s 
Mode of preparing Opium from Papaver somniferum; and Captain For- 
man’s Essay on a Property in Light.—4. Mr. Curnpert’s Hydro-pneu- 
matic Apparatus, &c.—5, Capt. FormAn’s Essay on the Reflection, &c. 
of Light; Mr, C. BonnycAstLe on the Influence of Masses of Iron on the 
Compass. 
Vol. LVI. 1. Mrs. Isserson onthe Physiology of Botany.—2. Mr. 
Hat's Percussion Gun-Lock; Dr. Kircuener’s Pancratic Eye-Tube ; 
Mr. Parx’s Mooring Blocks—3, Sections of Mr. MaLam’s Gas-Meter. 
-~*, Discoveries of Captain Panny in the Polar Sea. or 
