Cambridge Philosophical Society. 393 



investigation ; it is to be desired that not only the mean summer and 

 winter lines should he completed, but even those of months, which, 

 together with the observation of periodic phamomena of animal and 

 vegetable life, may lead to many important generalizations. 



Part X. — 1 The Mountain chains of Asia and Europe. 2. A 

 Chart of the Geographical distribution of the Currents of Air, show- 

 ing the course of the perennial, periodical and variable Winds, also 

 the various regions of prevalent Hurricanes. 3. An Ethnographic 

 Map of Europe. With this Part, which concludes the work, are 

 given useful Indices, in which the principal subjects illustrated are 

 arranged under the heads of the four great divisions of the Atlas, 

 viz. Meteorology, Hydrology, Geology, and Zoology- Phytology. 



Before taking leave of the Physical Atlas, we cannot but express 

 a sincere hope that the support which it may receive will be as 

 liberal as the spirit in which it has been executed. 



LXI. Proceedings of Learned Societies. 



CAMBRIDGE PHILOSOPHICAL SOCIETY. 

 [Continued from p. 31 7-] 

 May 22, COME Remarks on the Theory of Matter. By R. L» 

 1848. £3 Ellis, Esq., M.A., Fellow of Trinity College, Cambridge. 



The question to which these remarks principally relate is this : 

 Can all pha:nomena, e. g. those of chemistry, be explained mechani- 

 cally ? The writer, assuming that this question is to be answered 

 negatively, endeavours to determine what principles of causation, 

 beside mechanical force, may be introduced into physical theories, 

 consistently with the doctrine that the secondary qualities of bodies 

 are to be explained by means of the primary. His conclusion is, 

 that we are at liberty, in constructing an hypothesis as to the mode 

 of action of matter on matter, to introduce a new principle of causa- 

 tion (which he calls (force) 2 ), bearing the same relation to force that 

 force does to velocity ; and further, that following the analogy here 

 suggested, we may introduce an indefinite number of such principles, 

 viz. (force) 3 . . . (force)", &c, all essentially distinct from one another, 

 and from those previously recognised. 



But. on the other hand, he conceives that it is necessary to reject 

 any modification of qualitative action ; and that consequently physical 

 science, though it may cease to be wholly mechanical, will yet always 

 continue to be cinematical, in the largest sense of which this word 

 (so far as relates to local motion) can admit. 



June 5. — Methods of Integrating Partial Differential Equations. 

 By Prof. De Morgan. 



This paper contains a sketch of two distinct methods. In the first 

 (r, y, z, p, q, r, s, t, having their usual significations) the given equa- 

 tion is supposed to be of the form <p(x,y, p, q)=0, and this is made 

 the result of elimination between two equations involving a new 

 variable v. From these two, and their four differentials of the first 

 order, p, q, r, s, t are eliminated, and an equation of the first order 



Phil. Mag. S. 3. Vol. 33. No. 223. Nov. 1848. 2 D 



