Academy of Science in Paris, 569 



advanced by M. Delarive in opposition to Volta, that the action of 

 the contact was only the result of the difference of the chemical 

 actions of the air and water, and of external agents, on each of the 

 two bodies; and stated, that though he had at first been staggered 

 by it, the consideration that the electric fluid acts as a moving 

 power in producing combinations induced him to retain his original 

 opinion. In order to show the nature of this action in its full extent, 

 he pursued his experiments on mineral substances which are electric 

 conductors, and so little susceptible of atmospheric action, that their 

 constitution sustained no change from being exposed for ages to 

 the inclemency of the seasons. He details his experiments on 

 platina, peroxide of manganese, magnetic oxides of iron, and gold ; 

 from which it appeared that the peroxide of manganese was, as 

 might be expected from its high degree of oxydisation, negative in 

 its contact with all the other bodies. He next examines the causes 

 of the thermo-electric action in closed circles composed either of 

 one or of two different metals, and states, from all his experiments 

 it appears that these phenomena are owing to the difference of the 

 thermo-electric powers of the metals. From some observations 

 made on the relation between the thermo-electric faculties, and the 

 capacity for heat in various metals, it appears that those metals 

 which are most negatively electric have the least specific heat. 

 The memoir concludes with an expose of the electric properties of 

 atoms. M. Becqueril examines the theory of M. Ampere, and also 

 that of M. Begneul, who, from the experiments he had made, con- 

 cluded that the atoms in combination were merely small electric 

 piles, the reciprocal and continuous action of which constitute what 

 we call molecular attraction ; but M. Becqueril considers the 

 question, whether the action of particles of bodies on each other is 

 entirely produced by electric action or by some unknown power, as 

 still undecided. 



ZOOLOGY. 



Sturgeon. On the 24th January M. Cuvier made a very fa- 

 vourable report to the Academy on a work by Messrs. Brandt and 

 Ratzeburg, of Berlin, entitled the Monography of Sturgeon, in which 

 the genus is divided into fourteen species, which are described with 

 great minuteness, and in a manner calculated to be of great ad- 

 vantage to zoologists. 



Teleo-saurus. On the 21st February M. Geoffroy de St. Hilaire 

 presented his two memoirs on the animal, the fossil remains of which 

 were discovered in Normandy in the years 1828, 1829, and 1830, 

 which has been erroneously designated as the fossil crocodile of Caen. 

 He now names it the genus teko-saurus. These memoirs describe, 

 at great length, the difference between this animal arid the crocodile : 

 the scales have no centre ridge, but are placed one over the other 

 like those of fish, whence it is supposed that this animal was more 



