228 Analyses of Books* [Sept. 



III. A Communication of a singular Fact in Natural History . 

 By the Right Hon. the Earl of Morton, FRS. In a Letter 

 addressed to the President. 



Some account of this communication has been already given 

 in the Annals. 



IV. Particulars of a Fact, nearly similar to that related by 

 JLord Morton. Communicated to the President, in a Letter from 

 Daniel Giles, Esq. 



V. The Croonian Lecture. — Microscopical Observations on the 

 following Subjects : On the Brain and Nerves ; showing that the 



Materials of which they are composed exist in the Blood; On 

 the Discovery of Valves in the Branches of the Vas Breve, lying 

 ietween the villous and Muscular Coats of the Stomach ; On the 

 Structure of the Spleen. By Sir Everard Home, Bart. VPRS. 

 This paper cannot of course be rendered intelligible without 

 the plates which accompany it. 



VI. On Two New Compounds of Chlorine and Carbon, and on 

 a new Compound of Iodine, Carbon, and Hydrogen. By Mr. 

 Faraday, Chemical Assistant at the Royal Institution. Commu- 

 nicated by W. T. Brande, Esq. Sec. RS. and Prof, of Chemistry 

 at the Royal Institution. 



This very interesting paper has been given in the present 

 volume of the Annals. 



VII. An Account of the Comparison of various British Stand- 

 ards of linear Measure. By Capt. Henry Kater, FRS.&c. 



The commissioners appointed to consider the subject of 

 weights and measures recommended in the First Report, " for 

 the legal determination of the standard yard, that which was 

 employed by General Roy in the measurement of a base on 

 Hounslow Heath," as a foundation for the trigonometrical ope- 

 rations that have been carried on by the ordnance throughout 

 the country. In consequence of this determination, says Capt. 

 Kater, it became necessary to examine the standard to which the 

 Report alludes, with the intention of subsequently deriving from 

 it a scale of feet and inches. The object of this paper is to detail 

 the experiments for this purpose, and they appear to have been 

 conducted with the usual precaution and ability of their author. 

 Comparative measures of various standards are given in the form 

 of tables ; and the following one contains tjhe results deduced 

 by comparing each standard in succession with that used by 

 Col. Lambton in the Survey of India, an account of whose ope- 

 rations may be found in the Phil. Trans, for 1818. 



Excess of the following standards above Col. Lamhton's standard. On 36 inches. 



Sir G. Shuckburgh's standard + -000642 



Bird's standard of 1760 + '000659 



General Roy's scale + '001537 



Royal Society's standard + '002007 



Ramsden's bar (used in the Trigonometrical Survey 



of Great Britain) + -003147 



