REPOET ON THE TRANSACTIONS 



OF THE 



SOCIETY OF PHYSICS AND NATURAL HISTORY, OF GENEVA, 



FROM JULY, 1864, TO JL'XE, 1S65. 



BY M. E. PLANTAMOUR, PEESIDEKT. 



TRANSLATED FOR THE SMITHSONIAN INSTITUTION. 



According to established usage, I proceed, on quitting the presidency, to sub- 

 mit a report ot our transactions during the year which has iust elapsed The 

 statement which I shall read is an abridged reproduction of the proceeclin-s of 

 our meetmgs, though the chronological order has been changed for the purpose 

 of classifying the different communications according to the subject to which 

 they relate. In this classihcation I conform to the customary division between 

 the physical and natural sciences, although the line of demarcation between 

 these two branches of human knowledge is fiir from being distinctly drawn • in 

 not a few cases, in fact, it is somewhat difficult to decide under which of the 

 rin-ef "^^""'''^^ ''"'^''''' researches, relating to physiology or geology, ought to be 



PHYSICAL SCIENCES, 



M. Galopin presented the result of some theoretical researches which he had 

 made on the resistance opposed by fluids to the movement of solid bodies He 

 has been occupied especially with the effect which would be produced by differ- 

 ent solids of revolution moving in the direction of their axis, and he concludes 

 that bodies operate differently, according to their form, in modifying the density 



of the timd. — M. Achard communicated to the society a memoir, (Biblio- 



thequc Umi-crselle, Archives dcs Sciences Phys. et Nat., vol. xxii,) directed to 

 the study of the second principle of the mechanical theory of heat, discussing 

 therein the researches of Rankine and Clusius on this subject. He also madeS 

 report on an improvement applied by M. Foucault to the regulator with centri- 

 fugal force.— M. Lucien de la Rive read a note on an application of the 



calculation of probabilities. He proposes to determine the functions of time ex- 

 pressing the probability of the recurrence of an event a certain number of times 

 withm a given period. General Morin, being present at one of the meet- 

 ings, made a communication on his studies relating to ventilation, and on the 

 results obtained by the processes of ventilation established in the amphitheatres 

 of tlie Conservatory of Arts and Trades, and in some of the hospitals of Paris 



Professor Gautier has continued to keep the society apprised of the researches 

 of foreign astronomers, particularly of the discussions which are taking place in 

 i^ngland on the constitution of the surface of the sun, on the nature of the 

 spots, and on the appearances, likened by some to grains of rice, by others to 

 leaves of the willow At different sittings he analyzed the investigations of M. 

 y\ olf on the spots of the sun ; of M. Webb on the changes which are effected 

 at the surface of the moon ; of ]\I. Quetelet on the proper movement of the stars : 

 of M. Auwers on the orbit of Sirius. He gave an account, also, of the geodesic 



