HO 



The author then details at length the methods hy which he 

 effected these comparisons, and gives tables of the various measure- 

 ments, which are afterwards comprised in the following abstract, 

 taking Colonel Lambton's standard, used in the survey of India, as 

 the point of departure, in consequence of its being the shortest. 

 Captain Kater finds the excess on 36 inches to be as follows : 



Sir George Shuckburgh's standard + 000642 



Bird's standard, 1760 + 000659 



General Roy's scale + 001537 



Royal Society's standard + 002007 



Ramsden's bar, used in the trigonometrical survey + 003147 

 The author then proceeds to investigate the effect of these differ- 

 ences on the figure of the earth, and arrives at the conclusion, that 

 the comparison given in the abstract of Colonel Lambton's paper, 

 in the Philosophical Transactions for 1818, namely, -nrs--5-r should be 

 s-o-f-T-r. which agrees very nearly with the deduction of M. Laplace 

 from the lunar irregularities ; with the result of Dr. Young's inves- 

 tigation, by a comparison of the mean with the superficial density of 

 the earth ; and with the conjecture hazarded by the author, from 

 the compression given by the experiments on the length of the pen- 

 dulum at Unst and Portsoy. 



An Account of the Urinary Organs and Urine of Two Species of the 

 genus Ra/iu. By John Davy, M.D. F.R.S. Read January 18, 

 1821. [Phil. Trans. 1821, j>. 95.] 



The species of the genus Rana, adverted to in the title of this 

 paper, are the Rana taurina, or bull frog, and the Bufo fuscus, or 

 brown toad. 



The kidneys of the bull frog are lobulated, and the ureters termi- 

 nate in the rectum, between the orifice of the bladder and the anus ; 

 the bladder is large, and its orifice well calculated to receive the 

 urine as it flows from the ureters, its escape from the rectum being 

 prevented by the sphincter muscle of the anus. In the brown toad 

 the ureters have an analogous termination ; but the bladder when 

 distended resembles two oval bags, freely communicating just over 

 the symphysis pubis, to which they are firmly attached. 



The urine of the bull frog is without action on vegetable colours, 

 and contains urea, with traces of sea salt and a little phosphate of 

 lime. 



The author concludes this paper with some remarks relative to the 

 dissimilarity of the urine in animals, whose diet is similar, and con- 

 siders the nature of that secretion as depending rather upon the in- 

 timate and invisible structure of the kidney than upon the kind of 

 food which they consume. The brown toad and the lizard both live 

 upon flies, but their urine is very different; the parrot eats vegetables 

 only, and the snake feeds exclusively upon animal matter, yet in 

 them the urinary secretion is in all main points alike, uric acid being 

 the predominant ingredient in both. 



