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Some curious Facts respecting the Walrus and Seal, discovered by the 

 Examination of Specimens brought to England by the different Ships 

 lately returned from the Polar Circle. By Sir Everard Home, 

 Bart. V.P.R.S. In a Letter addressed to Sir Humphry Davy, 

 Bart. P.R.S. Read March 4, 1824. [Phil. Trans. 1824,^. 233.] 



The first fact stated by Sir Everard Home in this paper is the 

 analogy in structure between the hind foot of the Walrus and the 

 foot of the Fly. In both these is a very similar apparatus for produ- 

 cing a vacuum, so as to enable the animal to proceed upon smooth 

 surfaces against gravity, by the adhesion of the feet thus effected ; 

 there being two cups in the foot of the fly and one in that of the 

 walrus for this purpose. Secondly, he notices the peculiar mode in 

 which the bile in the walrus is collected in a reservoir, and thence 

 forcibly impelled into the duodenum. 



The third new fact which the author adduces, is the peculiar struc- 

 ture of the funis and placenta of the Seal. In this animal the vessels 

 forming the funis are not twisted ; their whole length is nine inches ; 

 after passing three inches from the navel of the foetus they give off 

 anastomosing branches, connected with it by three membranous folds, 

 between which the blood-vessels are conveyed to the placenta. This 

 structure gives uncommon facility to the placenta! circulation, and 

 makes it worth inquiry whether the same peculiarities exist in other 

 marine animals. 



Several illustrative drawings accompany this paper. 



Additional Experiments and Observations on the Application of Elec- 

 trical Combinations to the Preservation of the Copper Sheathing of 

 Ships, and to other purposes. By Sir Humphry Davy, Bart. P.R.S. 

 Read June 17, 1824. [Phil. Trans. 1824, p. 242.] 



Since his former communication the President has had an opportu- 

 nity of prosecuting his researches upon the above subjects, upon an 

 extended scale, and with results perfectly conclusive and satisfactory. 

 He found that sheets of copper defended by from one 100th to one 

 150th part of zinc or iron, exposed for many weeks to the full flow 

 of the tide in Portsmouth harbour, suffered no corrosion, and that 

 even one 1000th part of cast iron exerted great protecting influence. 

 Boats and the sides of ships protected in this way were also similarly 

 preserved. Of the different protecting metals cast iron is most conve- 

 nient, and the plumbaginous substance formed upon it does not impede 

 the electrical action. ThePresident formerly anticipated the deposition 

 of earthy substances upon the negative copper, and this he now found 

 to take place upon sheets of copper exposed about four months to sea- 

 water, and defended by from one 50th to one 80th their surface of 

 zinc and iron. They became coated with carbonate of lime and mag- 

 nesia ; but this effect is easily prevented by duly diminishing the pro- 

 portion of the protecting metal, so as to prevent the excess of negative 

 power in the copper, which then remains bright and clean.. 



