i36 Notices a7id Analyses. 



tructible even by fire, and distributed through air bodies ; and 

 on the generation of Monads. By Dr C. Aug. Sigm. Schultze. 

 4 to. Carlsruhe and Fribourg. 



The aubject of " active molecules," our readers will remember, has 

 already been discussed at some length in a former volume of this 

 Journal (Vol. I. p. 193. See also Additional Notices, L 229, and II. 

 384. ) The author of the work before lis (who seems not to have 

 been aware of Mr Brown's disavowal of the opinion that these 

 |)artieles are endowed with vitality) has arrived at very diiferent 

 results from those of our celebrated botanist. 



\sty He considers that the motion of the molecules is not spontaneous, 

 but depends either upon the evaporation of fluid, imbibition, or the 

 solution of the particles. If they are immersed in a liquid which 

 evaporates slowly, as oil, for example, the motion ceases ; whilst, on 

 the other hand, it is much more rapid in alcohol and ether. From 

 an attentive observation of these motions, M. Schultze has dis- 

 tinguished three kinds, which he refers to three different causes : The 

 first, ascent and descent, is produced by evaporation : the second, 

 oscillation, similar to the supination and pronation of the hand, is 

 owing to the successive imbibition of the molecules : and the third, 

 rotation, to their solution in the fluid. 



Hdy Mr Robert Brown had advanced the opinion, that the mole- 

 cules which he had observed in the pollen of plants are the same 

 as the elementary particles which compose all the organs of animals 

 and vegetables, and correspond to those described by Buffon, Need- 

 ham, Wrisberg, Miiller, and Milne Edwards. M. Schultze opposes 

 this proposition, as it respects organic molecules. These differ in 

 form and size in different animals and in different organs. As to 

 , Mr Brown's supposition that he has discovered molecules constituting 



] .. the elementary parts of inorganic bodies, it appears to M. Schultze 



that they are a more artificial product, and may be procured of any 

 given size by a certain degree of pulverization. 



Discours sur les Revolutions, S^c, Cuvier's Theory of the 

 Earth, 6th French edition, revised and enlarged. Paris, 1830. 

 Edmond d'Ocagne. 8vo. Pp. 408, and six plates. 



In this new edition of the Theory of the Earth, M. Cuvier has availed 

 himself of the notes which have been added by the English and 

 German translators, and has added the results of his own researches 

 since the publication of the first volume of the Ossemens Fossiles, of 

 which this treatise formed the Introduction. It is the intention of 

 M. Cuvier to enlarge upon the subject of this volume in a supplement 

 to his great work, wherein he will discuss the more recent geological 

 hypotheses. 



Memorie delta Reale Accademitty S^c. Transactions of the Royal 

 Academy of Sciences of Turin. Vol. XXXIII. 4to. pp. 735, 

 with 24 plates. 



The following Memoirs, appertaining to natural history, are contained 

 in this volume : — 



The second part of M. Losana's investigations on microscopic ani- 

 malcules. After having described those whose form varies, {poly- 

 morpha,) the author passes to those which undergo no change of 

 ^;^o: .- forjB, (mepomorphat) , He distributes them under nine genera, four 

 of which are described in this volume ; their species amount to 180. 



