ASTRONOMY AND METEOROLOGY. 303 



mg medicaments and perfumes by the so-called method of atomi- 

 zation, which has come into vogue within the last few.years, would 

 appear to be worthy of the careful study of meteorologists ; the 

 phenomena of transportation exhibited by the " atomizer 11 being 

 evidently akin to those manifested by the fogs and clouds which 

 occur in nature. In order to atomize a substance, it is first dis- 

 solved in water, and this aqueous solution is then, by means of 

 suitably disposed jets of air or steam, driven out of minute orifices 

 in the form of a finely divided spray or mist. This spray is in- 

 haled by the patient, and the physician is thus enabled to apply his 

 therapeutic agents, such as the various astringents and altera- 

 tives, directly to the diseased part of the throat or bronchial 

 tubes. 



Apart from its intrinsic scientific interest, this system of trans- 

 porting drugs by atomization was undoubtedly a very important 

 addition to the methods employed in the art of healing. But, as 

 now appears, it has led to a discovery of still greater consequence, 

 namely, to the production of local anaesthesia by freezing through 

 the agency of certain volatile liquids. 



ROSY AURORA. 



Among the latest explanations of the red glow and splendor of 

 sunrise and sunset which has been given, is that of Dr. E. Lom- 

 mel, in PoggendorfTs " Annalen," in which he shows it to be an 

 effect of diffraction of light, as viewed through a series of dark or 

 partially dark screens. He lays it down as an axiom that a point 

 of white light, viewed through a sufficient number of groups of 

 screens, appears not merely reddish itself, but also is surrounded 

 by a still more strongly red-colored aureole of diffracted light. 

 The lower stratum of the atmosphere is full of minute corpuscular 

 bodies dust, organic and inorganic, carbon or watery particles 

 which serve as dark screens, and when the sun is low, the rays, 

 traversing a long range of atmosphere, undergo diffraction, and 

 by superposition of adjacent points of light the effect of redness 

 is deepened. A mere red glow, without brilliance, is occasioned 

 by solid particles, as we see the sun red when viewing it through 

 smoke ; aqueous vapor, when present in the air, makes a diffused 



reddish light. 



VARIATIONS OF CLIMATE. 



We know little of the weather anterior to the historic period, 

 except what may be inferred from geological traces, and inciden- 

 tal notices bearing on the subject which have casually floated down 

 to us. But enough is known in these ways to decide, that the cli- 

 mate of particular regions has undergone great changes since the 

 creation, and even within the historical period. There is evidence 

 of a marked amelioration of climate, both in North America and 

 Europe, since the discovery of the western continent. While the 

 spread of agriculture and civilization undoubtedly has its effect in 

 this direction, there are also astronomical changes constantly in 

 progress, which control, slowly but irresistibly, the climatic con- 



