50 Royal Society. 



tion but not to exclude the air, at the end of eight months 

 the sulphuric acid was found saturated with copper, and the 

 bar covered with a thin crust of black oxide. With nitric 

 acid there was also a considerable deposition of protoxide of 

 copper on the bar, together with a little crystallized sub- 

 nitrate, and a very minute quantity of metallic copper. With 

 the muriatic acid, depositions similar to those with the nitric 

 acid took place, the submuriate being very abundant, and cry- 

 stallizing as in the native specimens of this mineral from Peru. 



The author considers the complicated results produced by 

 the presence of atmospheric air as referrible to electro-che- 

 mical action, arising from the reaction upon each other of 

 the combinations formed. 



A paper was likewise read, entitled, " On the structure of 

 the knee-joint in the Echidna setosa and the Ornithorhynchus 

 paradoxus; by G.Knox, M.D.F.R.S. E., communicated by 

 Sir James MacGregor, F.R.S." 



After a short review of the labours of comparative anato- 

 mists on the animals which are the subject of this memoir, the 

 author describes a peculiarity of structure which was discover- 

 ed by his brother in the knee-joint of the Echidna, consisting 

 of an extension of the ligamentum- adiposum, or re-duplica- 

 tion of the synovial membrane transversely across the whole 

 joint, dividing it into two cavities which have no distinct com- 

 munication with each other. The articular surfaces of the up- 

 per cavity are the patella and the anterior portions of the con- 

 dyles of the os femoris, while the lower are formed by the in- 

 ferior and superior surfaces of these condyles, the upper sur- 

 face of the tibia, and the semi-lunar cartilages. In the Orni- 

 thorhynchus paradoxus, the double fold of the synovial mem- 

 brane extends only half-way across the joint, thus constituting 

 an intermediate link of gradation between the Echidna and 

 Man, in whom the ligamentum adiposum is wholly within the 

 joint. 



Nov. 30.— At the Anniversary Meeting of the Royal So- 

 ciety on St. Andrew's day, — after the names had been read of 

 all Members deceased in the preceding year, and before the 

 Medals were delivered, Mr. Davies Gilbert (President,) ad- 

 dressed the Society to the following effect : 



Among the names now read, that of His Royal Highness 

 the Duke of York demands our first attention. 



We have in common with the whole nation to deplore the 

 loss of an illustrious personage, who has rendered most es- 

 sential services to his country by discharging the duties of a 



high 



