14-8 



tended ; in the viscera of these animals there is, however, a more 

 marked difference. 



The bones of the Sumatran tapir closely resemble those of the 

 American, but the skull of the former has a broader frontal bone, 

 and no middle ridge ; the nasal bones are larger, giving a propor- 

 tionate increased dimension to the nostrils. The skeleton of the 

 tapir differs from that of the rhinoceros in the smaller extent of the 

 scapulae and pelvis. 



The stomach of the Sumatran tapir is shaped like that of the rhi- 

 noceros ; the oesophagus is smooth and cuticular ; the small intestines 

 are 69 feet long ; the length and greatest breadth of the caecum is 1 

 foot ; the length of the colon and rectum is 1 9 feet 6 inches ; the 

 spleen is long and narrow ; the kidneys conglobate ; and the lungs 

 composed of one principal lobe on each side, of considerable length, 

 and two smaller lobes. 



On the Mean Density of the Earth. By Dr. Charles Hutton, F.R.S. 

 Read April 5, 1821. [Phil. Trans. 1821, p. 276.] 



Since the first notice of the determination of the mean density of 

 the earth by Newton, two experimental inquiries only have been 

 undertaken in relation to it ; namely, in the case of the Schehallien 

 experiment by the author and by Dr. Maskelyne ; and by Mr. Ca- 

 vendish, who used a method invented by Mr. Mitchell. 



Dr. Hutton proposes in this paper to show by a statement of, and 

 observations upon, the two methods, that the preference, in point of 

 accuracy, belongs to the mountain experiment over that of the small 

 balls employed by Mr. Cavendish ; and the results of this experi- 

 ment, duly corrected by that of Mr. Playfair's lithological survey of 

 the mountain, give the mean density of the earth equal to 5 times 

 the density of water, and not 4 '5, a number unfairly assumed on 

 some occasions, as the author's final determination. 



In adverting to the advantage that might result from a repetition 

 of the mountain experiment in some other favourable situation, and 

 with improved means, Dr. Hutton suggests the employment of one 

 of the large pyramids of Egypt for the purpose. The mass, he says, 

 is sufficiently large, and the station for the plummet or zenith sec- 

 tor might be taken much nearer the centre of the mass than on a 

 mountain, which would give a larger quantity of deviation of the 

 plummet. 



The regular figure and known composition of the mass would also 

 yield facilities in calculating its attraction ; and, moreover, the devi- 

 ation of the plummet might be observed on all four sides. 



On the Separation of Iron from other Metals. By J. F. W. Herschel, 

 Esq. F.R.S. Read April 5, 1821. [Phil. Trans. 1821, p. 293. 



After adverting to the importance of an easy means of effecting 

 the above purpose in analytical inquiries, and to the insufficiency of 



