672 



ACCOUNT OF THE 



coniequenee of his success in the cr.rc of cases of deafness, 

 arising from obstructions of the eustachian tube, by the 

 operation of perforating the membrane of the tympanum. 



The President, in an appropriate speech, bestowed on 

 Mr. Cooper the encomiums merited by his important im- 

 provement; and noticed, a.t the same time, that, in all 

 piobability, Chcselden wouldiiave been equally fortunate, 

 had he not been prevented by papular prejudice, from try- 

 ing the experiment on a condemned criminal. 



The rneeting of the loth of December was occupied by 

 «n abridged translation of a pamphlet of Mr. Piazzi, on the 

 supposed planet, which he discovered at Palermo, and 

 which he has named Ceres Ferdinandia. Its apparent dia- 

 meter wa^ seven seconds, its distance from the sun is nearly 

 three times that of the earth, and its period somewhat 

 more than five years. It does not, however, appear to be 

 by any means fully ascertained, that it deserves to be 

 considered as a true planet. The paper was communicated 

 by Dr. Maskelyne. 



On the 17th, Mr. Home's account of the anatomy of the 

 ornithorhynchus paradoxus was read. This singular ani- 

 mal appears to form a link between the mammalia and the 

 amphibia ; for while, in its general appearance, and in its 

 sanguiferous system, it reiembl<Sthe mammalia, especially 

 some of the order of bruta, both the absence of mammae, 

 and its internal anatomy render it probable that it is 

 oviparous. Its teeth too, when they are found, are but 

 four in number, and resemble the substance of horn more 

 than of bone. Its food is unknown, but its residence is 

 in the wa,ter. On its hind feet only, besides the five 

 « toes connected by a web, there is a detached process armed 

 ■with a spur. The paper was accompanied with numerous 

 drawings, and a dried specimen of the animal. 



Qn the 24th, a paper on friction, by Mr. Southern, was 

 communicated by Mr. Vince. Mr. Southern made a num- 

 ber of accurate experiments orj the motions of large grind- 

 stones, revolving with great rapidity, and ascertained the 

 power of friction on their axes, from the number of revolu- 

 tions which they performed, when set in motion with vari- 

 ous velocities. He considers the results as fully confirming 

 Mr. Vince's principle, that friction is a uniformly retarding 

 force : although the resistance of the air, and other acciden- 

 tal circumstances, introduced great irregularities into the 

 experiments. He found this force equal to about one foiv 

 tieth of the weight : the steel spindles running on brass, 

 v»ith the interposition of an unctuou? substance. 



The Society adjourned to Thursday the fourteenth of 

 JanHvy. 



3 



14th January, ! R02. A pajier on the propriety of separat- 

 ing geometrical fiom analytical expressions. By Robert 

 Woodhcmse, M.A. of Caius College, Cambridge. 



Mr. Woodhouse refers to his foriner communication, 

 printed in the PhilosophiCcil Transactions in isoi, for the 

 investigations which gave rise to the present discussion. He 

 had there stated the frequent imperfections of geometrical 

 analogy, when inferences are made from one figure to 

 others of a similar kind, and had insisted on the conelii- 

 sivcness of demonstrations, in which imaginary quantities 

 are employed, when understood in their true sense. He 

 nov/ continues the inquiry into the distinguishing characters 

 of geometry and algebra; and while he allows the advan- 

 tage of tlic geometrical method, in simple cases, he giver 

 a preference to algebraical analysis in all problems of a more 

 complicated nature: and endeavours to add still more to 

 the purity of the analytical representation, by banishing 

 from it all expressions, which have any reference to 

 geometry. The computations inserted were not capable of 

 being read to the Society; but the author states, in the con- 

 clusion, that he has deduced, in a manner purely algebrai- 

 cal, the formulas for the sine in terms of the arc, for any 

 multiple of an arc, and for other similar angular functions, 

 which have been usually considered as most intimately 

 connected with geometry. 



aist January. A paper on the (»hen«mena of galvanism. 

 By George Smith Gibbes, M. D. F. R. S. 



Dr, Gibbes begins with reciting some experiments on 

 the oxidation produced during the union of tin foil with 

 mercury, first in the air, and then under water. He as- 

 sumes a different opinion from that of Dr. WoUaston, re- 

 specting the origination of electricity in chemical 

 changes, and maintains, on the contrary, that the electri- 

 cal changes are to be considered as preceding and favour- 

 itvg the chemical. He imagines that the simple contact of 

 various substances produces changes of electrical equili- 

 brium, iind that the action of acids is efTectual in promot- 

 ing these changes, by bringing their surfaces into contact; 

 Dr. Gibbes observes upon Dr. WoUaston's experiment of 

 immersing zinc and silver in an acid solution, that if they 

 are placed in two separate portions of the fluid, and the 

 parts not immersed are brought into contact, there is no 

 emission of gas from the silver ; but that it is copiously pro- 

 duced when the contact takes place in the same fluid. He 

 proceeds to relate some experiments which seem to show a 

 difference between galvanism and electricity, particularly 

 that galvanism does not appear to be attracted by metallic 

 points. He also states an experiment in which a piece of 



