268 Report of Clicmisiry and Experimental Philosophy. 



rine that wc must rest content with mere 

 jjost hoc information. 



Jiedfoid row ; D. UwiNS, M.D. 



Ma'ck '20, J8'.':i. 



*^* 'J'lic Reporter is happy to find that 

 his reconmicndation of wash-leather has 

 been so extensively acted on : he refers 



[April 1, 



Number of this Maiazine; and need only 

 add, that, wlien worn under the hncn, tlie 

 waistcoat shniiM l)e made to double over 

 in front, and fastened on one side by 

 strincs. The fastenini; at the wrist is bet- 

 ter effected by a button. When the lea- 

 ther is worn over the shirt, it may be co- 

 enquirers, as to the mode and limes of vered by a light material, so as to appear 

 wearing it, to a letter in the February like a common under-waistcoat. 



REPORT OF CHEMISTRY AND EXPERIMENTAL PHILOSOPHY. 



'X'HE incessant labours of experimental 

 -*■ philosopliers continue almost daily to 

 deveiope some new fact or principle re- 

 Jatins: to magnetism, that very mysterious 

 accident of certain bodies, which so long 

 liad defied experimental ingenuity to ascer- 

 tain its, principles. Professor Oersted 

 has lately ascertained, by a decisive expe- 

 riment, that a round galvanic conductor 

 of the electric fluid, is in every portion of 

 its surface equally fitted to act on the 

 magnetic needle ; and that this action is 

 not greater at the extremities, or at any 

 other points of the conductor, analogous to 

 poles, as some have supposed. Mr. J. H. 

 Abkaham has also discovered, that the 

 poles of a magnetised steel bar are not ne- 

 cessarily situated at its extremities; but, 

 by a particular mode of touching, (which 

 he has laid before the Royal Society,) he 

 lias been able to produce bars, both of 

 whose ends have similar poles, whilst the 

 middle of these bars exhibit the opposite 

 polarity. The same gcnllemav hits also veri- 

 Jieil the fine discovery of Ulr, Harlow, as to 

 magnetism affecting or residing only in the 

 superficial parts of musses of iroti or steel; 

 and has experimentally proved, tJiat mag- 

 netised flat bars, one-tenth of an inch thick, 

 are equally powerful, with bars of consi- 

 derably larger dimensions and weight, un- 

 der the same extent of surface. 



Hitherto there has been no evidence 

 of the thermometer acquiring warmth 

 from the rays of the moon, thongh col- 

 lected in the focus of a burning mirror, 

 and calculations have been made to prove 

 that they do not excite any. Dr. 

 Howard, of the United Statrs, however, 

 maintains that those calculations and ex- 

 periments are inaccurate. With a ther- 

 mometer of his own constrnctioii, — which 

 he calls Differential, — he has had proofs of 

 the rays of a full moon received on a con- 

 cave muror, a foot in diameter, raising the 

 fluid eight degrees. 



The ear of the human subject, and par- 

 ticularly the mmihranu lympani, or what is 

 conniionly called tho drum of the ear, has 

 hiiely been the subject of minute anato- 

 mical investigation by Sir E. Home ; and 

 by whom it has been discovered, contrary 

 1o former opinion, that this membrane is 

 muscular in its structure, and composed of 

 a series of muscular radii, ail of cqiial 



length, owing to the exactly circular form 

 of this membrane, and meeting in its cen- 

 tre. It is to this exact equality in the 

 lengths of the muscular fibres in the hu- 

 man ear, that Sir Everard attributes its 

 great capability of appreciating musical 

 sounds : he has, on the contrary, fonnd 

 the elephant's car to have an oval mem- 

 brane, with fibres very unequal in length 

 amongst themselves ; and to this circum- 

 stance he attributes the alleged insensi- 

 bility of the elephant to any but low or 

 grave sounds: a circumstance which we 

 do not remember to have heard noticed, 

 some twenty-five years ago, when the 

 sarans of Paris, having a pair of large ele- 

 phants, in whom they hoped to excite amo- 

 rous emotions, that they might breed, en- 

 tertained them with a fine concert of music. 

 In the present instance, one of T-Ir. Broad- 

 wood's pianos was thought sufficient for 

 the experimental entertainment of the 

 elephant, the lion, and the oilier outlandish 

 inhabitants of Exeter 'Change. We here 

 beg respectfully to ask of Dr. WooUaston, 

 whether this discovery, as to eqnal radial 

 fibres, or otherwise, can account for tiiose 

 very ditt'erent capacities for appreciating 

 very high or very low sounds, by particular 

 persons, which he discovered a few years 

 ago, and ably ilhistrated? Whether a 

 round tympanum may not have unequal 

 radii, through the want of concentricity, 

 and how this may aflect the ear's capa- 

 bility ? 



Mr. Phtlip Taylor, an experienced 

 operative chemist in the neighbourliood of 

 London, has lately pnbhshed in the " Phi- 

 losophical Magazine," a valuable series of 

 experiments, in a tabular form, on the 

 heat and expansive force of steam, at all 

 temperatures, from 212" F. to 320-" ; mea- 

 sured in inches height of mercury, support- 

 ed in a barometer tube, viz. from (for 

 the atmospheric pressure,) to l.iO inches; 

 and measured also, in pounds pressure, on 

 a square inch of surface, viz. from to 

 73 lbs. From whence it appears, that an 

 increase of 39° of heat above boiling wa- 

 ter (in the open air) produces the first 

 additional atmosphere of pressure, 24" 

 more produces a second, 18° more pro- 

 duces a third, 15° more a fourth, and a 

 fiutlipr addition of little more than 12° 

 above the last temperature, produces a 



fifth 



