X NOTES BY THE EDITOR. 



that in any ordinary liquid the mean distance between contig- 

 uous molecules, is less than one one-millionth of a centimeter 

 and greater than one two-millionth. 



Dr. Angus Smith, in England, in connection with his work as 

 Inspector under the Alkali Act, has been carrying on chemical 

 examinations of the air and rain in various localities, and collect- 

 ing statistics looking towards the establishment of a new branch 

 of meteorology, chemical climatology. While the methods of 

 analysis are already tolerably satisfactory as far as the determina- 

 tion of the various gases naturally or accidentally present in the 

 air, and of the various saline matters contained in the rain, the 

 great problem bearing upon health -the determination of the 

 amount of organic matter in the atmosphere and its character, 

 whether harmless or injurious is still far from being solved. 



While in technical chemistry there is little to record that is 

 strictly new, attention may be called to the great change wrought 

 in one of the most important of the applications of chemistry 

 to the arts, namely, the manufacture of chlorine. Weldon's pro- 

 cess (see page 166), announced at the meeting of the British Asso- 

 ciation in 1869, is supplanting the old method, to considerable ex- 

 tent, both in England and on the continent. That the process is, 

 however, still imperfect, is evident from the fact that two-thirds 

 of the chlorine in the chlorhydric acid employed goes to waste. 

 The ingenious process of producing chlorine without the use of man- 

 ganese, suggested by Henry Deacon (see page 169), while theoreti- 

 cally excellent, presents practical difficulties which have not been 

 surmounted so as to bring the method into actual use. 



Geology. The most interesting results which have recently 

 been obtained have been the results of the deep-sea dredgings, 

 carried on along the Atlantic coast on both sides of the ocean, 

 with assistance from the governments of Great Britain and the 

 United States. The facts thus obtained in regard to the mode of 

 deposition of calcareous and other sedimentary rock-strata, and 

 in regard to the distribution of animal life, are of the highest 

 importance. It seems that there is no limit to the depth at 

 which animal life can exist; many genera and species, hereto- 

 fore considered extinct, have been found to have living representa- 

 tives ; the influence of warm and cold currents is shown to be very 

 great on the fauna of a given area, so that side by side deposits 

 are forming, one containing the remains of arctic, and another the 

 remains of temperate or even tropical species. A somewhat 



