PHYSICS AND NATURAL HISTORY OF GENEVA. 235 



Thus, then, in the report which we are about to present, we 

 comprehend under the same head of Physical Sciences, mechanics, 

 astronomy, physics, both mathematical and experimental, terrestrial 

 and meteorological, as well as chemistry — sciences whose points of 

 contact are so numerous and so multiplex that it is difficult to deter- 

 mine the limits which separate them. Geology, mineralogy, and 

 organic natural history, botany, and zoology, (comprising therein 

 physiology) form the second group, which, under the head of Natural 

 Sciences, constitute likewise an assemblage sufficiently compact, to 

 which palaeontology accedes as a cement binding all the parts together. 

 "We confess that we are at a loss to know to which of these groups 

 statistics should be referred, which, like mathematics, find a place 

 among us. only by virtue of their application, and whose labors, there- 

 fore, ought to be classed, it would seem, according to the nature of the 

 application which is made of them. 



PHYSICAL SCIENCES. 



It is natural to place at the head of the physical sciences that 

 which, lifting the regards of man towards the celestial vault, seems 

 more suited than any other to recall to him the magnificence of the 

 creation and the greatness of its Author. Some years ago, and as- 

 tronomy might have been thought to have uttered its last word. 

 Certain stars*to be discovered in the immensity of the heavens, im- 

 proved methods to be invented for calculating the courses of the 

 celestial bodies — these seemed to be the only lines in which progress 

 was possible after the labors of the Herschels and La Places; but 

 thanks to the improvement of instruments and the perseverance of 

 observers, a new era has dawned for this part of the sciences. New 

 planets, announced, like Neptune, through the potency of the genius of 

 mathematics, or discovered simply by a conscientious exploration of 

 the skies, are constantly ranging themselves in our astronomical cata- 

 logues; a more profound study of the physical properties of the stellar 

 bodies leads to inductions of the highest interest with regard to their 

 physical constitution; and the aid of powerful glasses unveils to us 

 in the fixed stars the nebulae and the comets — appearances till now 

 unknown. 



I have mentioned comets. Of course there was much question in 

 the society respecting that of Donati, which was the great astronom- 

 ical event of the year 1858. Professor Thury was the first who oc- 

 cupied our attention with some observations he had made on that 

 body, the tail of which he had found to be double near the nucleus. 

 Still later, Professor Plantamour communicated a summary of the ob- 

 servations made upon it at the observatory of Geneva, from August 

 28, to October 18. In that interval of time, the number of days of 

 observation was 29, for which the position of the comet was deter- 

 mined by comparison with the neighboring stars. From these obser- 

 vations, and those made by different astronomers, it results that the 

 part of the orbit traversed by the comet before passing to its peri- 

 helion is an ellipsis which would require from 2,100 to 2,400 years as 



