PROCEEDINGS OF SOCIETIES. 26$ 



is in ye. I have dwelt a little on this principle of connection, in order that I 

 might illustrate both the mode and the importance of taking general and not par- 

 tial views of Nature." 



Resuming the immediate subject of his lecture, Dr. Boisragon proceeded to 

 point out the importance of Meteorology, viewed in connection with the various 

 pursuits and occupations of men, and gave a full and comprehensive definition of 

 the term itself. The chief elements comprised in the science were ranged under 

 three general heads, viz. — air, water, and luminous meteors, connected with the 

 operation of which were to be considered their four chief agents — gravitation, 

 light, heat, and electricity. The peculiar properties of air were described, and 

 many of the phenomena which result from its weight, transparency, electricity, 

 and refraction were briefly adverted to. The effects of heat upon the atmos- 

 phere or air were explained, as were the construction of the various philosophical 

 instruments invented for the purpose of ascertaining and determining temperature. 

 With the description of these instruments the lecturer was compelled to close his 

 discourse, the time allowed having expired. The further discussion of the subject 

 was accordingly postponed till Friday. 



On Friday evening, February 2, Dr. Boisragon delivered his second lecture on 

 Meteorology. After recapitulating the leading points of the first lecture, a brief 

 description was given of the various instruments employed for meteorological 

 observations, and the principles of their construction explained. In speaking of 

 the aethrioscope, the nature of hot and cold pulses was inquired into. " The hot 

 pulse, or aerial wave (observed the lecturer), commences from some body or sub- 

 stance imparting a portion of heat to a contiguous particle of air, which thereupon 

 expands ; the next particle does the same, depriving the former of its heat, which 

 again contracts ; and so on successively, — forming pulses continued into the 

 upper regions, and originating at the surface of the earth. The cold pulses, which 

 are by some thought to be positive cold sent from above, are nothing more than 

 the air deprived of its heat : these also commence at the surface of the earth, 

 being caused by the successive contraction and expansion of the particles of air, as 

 each deprives the particle above it of its caloric." After explaining other phe- 

 nomena incident to the effects of heat upon the atmosphere, Dr. Boisragon 

 proceeded to speak of this powerful agent as producing the operation of land and 

 sea breezes, which was illustrated by an ingenious experiment. Adverting to 

 the affections of the barometer from aerial currents, mention was made of Kir- 

 wan's beautiful theory of partial accumulations of air being caused by the higher 

 column at the Equator gravitating towards the Pole, and thereby influencing the 

 course of the currents described — the objections of Lieut. Morrison to Kirwan's 

 theory were stated, and that gentleman's views of atmospheric electricity briefly 



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