CONTENTS. 
I. The Croonian Lecture on the Arrangement and mechanical 
Action of the Muscles of Fishes. By Anthony Carlisle, Esq , 
F. R. S. F. L. S. page 1 
II. The Bakerian Lecture on the Force of Percussion. By William 
Hyde Wollaston, M. D. Sec. R. S. p. 13 
III. Memoire sur les Quantites imaginaires. Par M. Buee. 
Communicated by William Morgan, Esq. F. R. S. p. 23 
IV. Chemical Experiments on Guaiacum. By Mr. William 
Brande. Communicated by Charles Hatchett, Esq. F.R.S. 
p. 89 
V. On the Direction of the Radicle and Germen during the 
Vegetation of Seeds. By Thomas Andrew Knight, Esq. 
F. R. S. Jin a Letter to the Right Hon. Sir Joseph Banks, 
K.B.P.R.S. P - 99 
VI. A third Series of Experiments on an artificial Substance , 
which possesses the principal characteristic Properties of Tannin ; 
with some Remarks on Coal. By Charles Hatchett, Esq. 
F. R. S. p. 109 
VII. The Application of a Method of Differences to the Species 
of Series whose Sums are obtained by Mr. Landen, by the Help 
of impossible Quantities. By Mr. Benjamin Gompertz. 
Communicated by the Rev. Nevil Maskelyne, D. D. Astro- 
nomer Royal , F. R. S. p. 147 
