341 



that pus does not contain so much potash or muriate of soda as is 

 contained in the above expectorated secretions. 



Dr. Pearson also thinks it much more probable that the circulating 

 and secreted fluids are impregnated with potash, as he has observed, 

 than with soda, as observed by others. 



Finally, we are informed, that expectorated matter contains glo- 

 bules, which have not before been observed, and seem to the author 

 to denote organization. 



On the Attractions of homogeneous Ellipsoids. By James Ivory, A.M. 

 Communicated by Henry Brougham, Esq. F.R.S. Read June 15, 

 1809. [Phil. Trans. 1809, p. 345.] 



The theory of the figures of the planets involves two questions 

 perfectly distinct from each other ; first, the figure which a mass of 

 matter would assume by the mutual attraction of its particles, com- 

 bined with a centrifugal force, arising from rotatory motion ; and 

 secondly, the force with which a body so formed will attract a par- 

 ticle occupying any proposed situation. The latter is the subject of 

 the present inquiry ; and it is also limited to the consideration of 

 homogeneous bodies bounded by finite surfaces of the second order. 



This subject was first partially treated of by Sir Isaac Newton, 

 who, in determining the attraction of spherical bodies, has also treated 

 of other solids, formed by the rotation of curves^ round an axis, and 

 of the attractions they exert upon bodies placed in the line of their 

 axes. MacLaurin was the first who determined the attractions that 

 such spheroids of revolutions exert on particles placed anywhere, 

 either in or within their surfaces. 



Le Gendre extended the same inquiry to particles without the 

 surface of such solids of revolution. 



La Place took a more enlarged view, and extended his researches 

 to all elliptic spheroids, not formed by revolution, but such whose 

 three principal sections are all elliptical; and he arrived at conclusions, 

 with regard to them, similar to those of MacLaurin and Le Gendre. 



But notwithstanding the ingenuity and skill displayed by La Place 

 in this investigation, Mr. Ivory conceived that the inquiry might be 

 simplified, and the results obtained more directly, by a method which 

 forms the subject of the present communication ; which, however, is 

 of a nature not adapted for public reading. 



Observations on Albumen, and some other Animal Fluids ; with Re- 

 marks on their Analysis by electro-chemical Decomposition. By 

 Mr. William Brande, F.R.S. Communicated by the Society for 

 the Improvement of Animal Chemistry. Read June 15, 1809. 

 [Phil. Trans. 1809, p. 373.] 



Mr. Brande's paper consists of two parts ; first, Observations on 

 mucus and on the composition of liquid albumen ; and secondly, On, 

 the composition of some animal fluids containing albumen. 



