348 Analysis of Scientific Books. 



of its forming little or no insoluble compound in brine or sea- 

 water, will be preferable to iron for this purpose ; and whether 

 this metal or iron be used, the waste will be much less than if the 

 metal was exposed on the outside : and all difficulties with re- 

 spect to a proper situation in this last case are avoided. 



" The copper used for sheathing should be the purest that 

 can be obtained; and in being applied to the ship, its surface 

 should be preserved as smooth and equable as possible: and the 

 nails used for fastening should likewise be of pure copper ; and a 

 little difference in their thickness and shape will easily com- 

 pensate for their want of hardness. 



" In vessels employed for steam navigation the protecting 

 metal can scarcely be in excess ; as the rapid motion of these 

 ships prevents the chance of any adhesions ; and the wear of the 

 copper by proper protection is diminished more than two-thirds." 



vii. On the Magnetism of Iron arising from its rotation. By Samuel 

 Hunter Christie, Esq., M.A., of Trinity College, Cambridge ; 

 Fellow of the Cambridge Philosophical Society ; of the Royal Mi- 

 litary Academy. Communicated April 20, 1825, by J. F. W. 

 Herschel, Esq., Sec. R. S. 



The principal heads of this paper have already been laid before 

 our readers, (see Vol. xix. p. 264,) and its length prevents our 

 doing further justice to it, in the form of an abstract. 



viii. Some account of the Transit Instrument made by Mr. Dollond, 

 and lately put up at the Cambridge Observatory. Communicated 

 April 13, 1S25. By Robert Woodhouse, A.M. F.R.S. 



ix. On the fossil Elk of Ireland. By Thomas Weaver, Esq., Mem- 

 ber of the Royal Irish Academy, of the Royal Dublin Society, 

 and of the Wernerian and Geological Societies. 



x. Microscopical Observations on the Materials of the Brain, and of 

 the Oca of Animals, to shew the analogy that exists between them. 

 By Sir Everard Home, Bart., V. P. R.S. 



For an account of the contents of these three communications 

 we refer to our account of the proceedings of the Royal Society, 

 at the time they were read. (Vol. xix. p. 268.) 



On New Compounds of Carbon and Hydrogen, and on certain other 

 Products obtained during the Decomposition of Oil by Heat. By 

 M. Faraday, F.R.S. , Corresponding Member of the Royal Aca- 

 demy of Sciences. 



The principal object of this paper is to describe two new com- 

 pounds of carbon and hydrogen. It commences with a descrip- 



