y[ CONTENTS. 



IX. Researches on Heat. Third Series. ^ 1. On the unequally Polarizahle 

 Nature of different kinds of Heat. § 2. On the Depolarization of Heat. 

 ^ 3. On the Refrangibility of Heat. By James D. Forbes, Esq., 

 F.R.SS. L. 8^ Ed., Professor of Natural Philosophy in the University of 

 Edinburgh, ........... 176 



X. On the Real Nature of Symbolical Algebra. By D. F. Gregory, B A., 



Trin. Coll. Cambridge^ 208 



XI. Investigation of a New Series for the Computation of Logarithms ; with a 

 New Investigation of a Series for the Rectification of the Circle. By 

 James Thomson, LL.D., Professor of Mathematics in the University 

 of Glasgow, ........... 217 



XII. Of the Third Pair of Nerves, being the first of a series of Papers in ex- 

 planation of the difference in the origins of the Nerves of the Encephalon, 

 as compared ivith those which arise from the Spinal Marrow. By Sir 

 Charles Bell, K.H, F.R.SS. L. 8^ Ed., M.D.H.Gott., Sfc. . . 224 



XIII. Of the Origin and Compound Inunctions of the Facial Nerve, or Portio 



dura of the Seventh Nerve ; — being the Second Paper in explanation of 

 the difference between the Nerves of the Encephalon, as contrasted tvith 

 the regidar Series of Spinal Nerves. By Sir Charles Bell, K.H., 

 F.R.SS. L. Sf E., M.D.H.Gott., Sfc 229 



XIV. Of the Fourth and Sixth Nerves of the Brain; — being the concluding 



paper on the distinctions of the Nerves of the Encephalon and Spinal 

 Marrow. By Sir Charles Bell, K.H., F.R.SS.L. ^Ed., M.D.H.Gott., 

 &p 237 



XV. Inquiry whether Sea- Water has its Maximum Density a few Degrees 

 above its Freezing Point, as Pure Water has. By Thomas Charles 

 Hope, M.D., V.P.R.S.Ed., F.R.S., Professor of Chemistry in the Uni- 

 versity of Edinburgh, ......... 242 



XVI. On the Mid-Lothian and East-Lothian Coal-Fields. By David Milne, 



Esq., F. R.S.Ed., F.G.S. 253 



