CONTENTS 01' VOL. V. — FOURTH SERIES. y 



a^a'l Page 



Proceedings of the Royal Institution 218 



^3^0ticesof the Superposition of certain Minerals in some Mining 



Districts of Germany 227 



On the Presence of Boracic Acid in the Thermal Waters contain- 

 ing Alkaline Sulphurets at D'Olette (Eastern Pyrenees), by 



V i Jules Bonis 229 



On the Presence of Boracic Acid in the Mineral Waters of Wies- 

 baden and Aix laChapelle, by R. Fresenius and R. Wildenstein. 230 

 On the Per-centage of Zinc in Brass and Bronze, and the Sepa- 



P, ; ration of Zinc from Coppv^r, by M. Bobicrre 230 



On the Presence of Sugar in the Urine of Epileptic Patients, by 



MM. Michea and Alvaro Reynoso . ..»....,• • . ■ • >.. 230 



Meteorological Observations for January 1853 ..,;,:. -i.mn3«'^>.;23l 

 li^'i .....,- Table., ,,,....., .^ .,^ „,„> ^^.-/o*. *r>3.k>»"-»^fl.|>j» ^^ 

 0^1 o{}9iooB i mimomWaA iH'ro'd 



XH I. ... NUMBER XXXII.-APRIL. ibbmrT .f : 



^Siir David Brewster on Cavities in Amber containing Gases and ' ' 



Fluids 233 



^^ir David Brewster's Account of a remarkable Fluid Cavity in 



"' Topaz 235 



Mir W. R. Hamilton on Continued Fractions in Quaternions 



(continued) 236 



Dr. Frankland on a New Series of Organic Bodies containing 



Metals 239 



Mr. A. Tylor on Changes of the Sea- Level effected by existing 



Physical Causes during stated Periods of Time 258 



jMr. A. Cayley's Note on the Geometrical Representation of 



the Integraiyi^cr— ^ {x + a) (x i- b) (a^ + cf 281 



(Dr. Mallet's Analysis of a Siliceous Deposit from the hot 



Volcanic Springs of Taupo, New Zealand 285 



Mr. T. K. Abbott on a Geometrical Problem noticed by Mr. 



Sylvester 286 



Prof. Thomson on the Mutual Attraction or Repulsion between 



<^8 two Electrified Spherical Conductors 287 



Dr. Adamson on a proposed Test of the Necessity of Indirect 

 r,f Proof in Geometrical Demonstrations, with Remarks on Me- 

 thods of Demonstration 297 



Mr. J.J. Sylvester, A Proof that all the Invariants to a cubic 

 Ternary Form are Rational Functions of Aronhold's Invari- 

 ants and of a cognate theorem for biquadratic Binary Forms. 299 



Proceedings of the Royal Institution 303 



On a Peculiarity observed in a Luminous Arch, by W. Pringle. 308 

 On the Periods of Revolution of the Satellites of Jupiter and 



K(' Saturn, by A. Quetelet .... 309 



On the Distribution of Gold, by Dr. Percy .u is . .-jjiiily w 310 



Meteorological Observations for February 1853 . . wj . ;^'*i,;,v^i *'311 

 ■ f^ Table ajiMr:* i»ycv/i.-.i.iJ. tebi^'^alb.'* 3kl8 



