Cambridge Philosophical Society. — Royal Institution. 387 



and 1823 he published Appendixes to this work. His collection was 

 also further made known by articles in Leonhard's Mineralogical 

 Pocket Book and in the Isis. After his death a new description of 

 this collection M'as announced, but Avhether it appeared I am not 

 able to say. Schlotheim's introduction to his account of his collec- 

 tion contains some extensive geological views. 



It is only justice to M. de Schlotheim to add here what is said of 

 him by M. Adolphe Brongniart, whose own labours on fossil vege- 

 tables have been of such inestimable value to the geologist, and are 

 every year increasing in interest. " Almost half a century," he says, 

 " elapsed, during which no important work appeai'cd on this subject. 

 It was not till ISO* that the ' Flora of the Ancient World,' by M, 

 de Schlotheim, again turned the attention of naturalists to this branch 

 of science. More perfect figures, descriptions given in detail and 

 constructed with the precision of style which belongs to botany, and 

 moreover some attempts at comparison with living vegetables, showed 

 that this part of natural history was susceptible of being treated like 

 the other branches of science : and we may say, that if the author 

 had established a nomenclature for the vegetables which he described, 

 his work would have become the basis of all the succeeding labours 



on the same subject." 



CAMBRIDGE PHILOSOPHICAL SOCIETY. 



Februaiy 1 8th. — Dr. Graham the president, in the chair. The 

 conclusion of a paper by Mr. Rothman was read, " on the ancient 

 climate of Italy and other countries." Also, a paper, by Mr. Potter, 

 " on the determination of the length of an undulation of light by 

 various methods;" and an appendix, by Mr. Green, to a former 

 paper on waves. 



March 4th. — Dr. Graham in the chair. Various presents were 

 announced, and among the rest, as presents from the Natural Hi- 

 story Society of Liverpool, two casts, and several lithographic prints 

 of the footsteps of an unknown animal, found in the sandstone of 

 the promontory of Wirrall, which lies between the mouth of the rivers 

 Mersey and Dee. The most conspicuous of tliese footsteps agree 

 exactly with those found by Professor Kaup, in Saxony, ascribed by 

 him to an animal which he has termed the Chirotherium. After- 

 wards Mr. Hopkins gave an account, illustrated by diagrams, of the 

 geology of the parts of England and France in the neighbourhood of 

 the British Channel. 



March 18th. — Dr. Graham in the chair. A communication was 

 made by Mr. Eamshaw, on the equilibrium of a system of particles. 

 After this the Astronomer Royal gave an account of the mode now 

 employed for observing the diurnal changes of the variation of the 

 magnetic needle. He also urged the importance of having observa- 

 tions corresponding with the simultaneous observations now made 

 in various parts of Europe, undertaken by some persons interested 

 in the subject residing in Cambridge. 



FRIDAY-EVENING MEETINGS AT THE ROYAL INSTITUTION. 

 February 22nd. — Mr. .Johnston on the leading distinctions in the 

 investigation of mental and physical phaenomena. 

 2C2 



