248 ANNUAL OF SCIENTIFIC DISCOVERY. 



from its solution in potash, and a precipitate of silver is obtained from 

 a solution of nitrate of silver in ammonia. Osann has also given con- 

 siderable attention to ozonized air, and that mixture obtained by pass- 

 ing air over phosphorus, transmitting it first through a solution of 

 iodide of potassium, and then, when freed from ozone in this manner, 

 collecting it in a glass vessel. As soon as this was filled, the opera- 

 tion was discontinued. After about twenty-four hours, the white va- 

 por had disappeared, and the water closing the bell-glass had an acid 

 reaction. Mixed with lime-water no precipitate resulted, but on boil- 

 ing the liquid a white powder separated, whence it follows that this 

 substance is phosphorous acid. It would at the same time follow 

 that there are two modifications of phosphorous acid ; one of which 

 resists combination with water, and the other not. Now, says Osann, 

 if ozone is only a modification of oxygen (active oxygen), it must be 

 distinguished from .the passive modification, as is done for these condi- 

 tions in other bodies. The same would also apply to phosphorous 

 acid, and it would then be worthy of remark, that, in the preparation 

 of ozone by means of oxygen, the phosphorous acid is converted into 

 the passive, and the oxygen into the active modification. 



Connection of Ozone and Diseases. Considerable attention having 

 been drawn, during the summer of 1849, to the subject of the influ- 

 ence of ozone, from a fancied connection between it and the cause of 

 the Asiatic cholera, the following suggestive thoughts have been pub- 

 lished by Robert Hunt, of London. He says, "All living animals and 

 vegetables are constantly throwing off from their bodies organic mat- 

 ter in a condition the most fitted for recombination with the chemical 

 elements of the air. The gaseous exhalations from all dead matter 

 are constantly combined with organic particles in a state of extreme 

 division. Thus, the atmosphere is constantly receiving exhalations 

 from the earth and its inhabitants, which, without a provision for their 

 removal, would speedily become far more injurious to all forms of life 

 than carbonic acid ; though to that alone we have been in the habit of 

 too commonly attributing atmospheric deterioration. Ozone, then, in 

 the opinion of Mr. Hunt, is the great natural agent employed to con- 

 vert all those deleterious exhalations which the air receives into in- 

 nocuous matter. An atmosphere artificially charged with ozone imme- 

 diately deprives the most putrid solid or fluid bodies of all disagreeable 

 smell, and sulphuretted hydrogen is instantly decomposed by it. In 

 fact, its action upon organic matter is far more energetic than that of 

 chlorine. 



" It has been proved that the electrical intensity of the atmosphere 

 was, during the prevalence of the cholera in 1849, diminished in a re- 

 markable manner. At St. Petersburg magnets lost their power, 

 and in Paris electrical machines would not give out sparks during 

 the ascendancy of the cholera in those cities. Quetelet has proved 

 that the electrical intensity of the atmosphere was, during the whole 

 year, about one half that observed during former years, and that from 

 the 1st of January, 1849, up to a certain period, it regularly dimin- 

 ished, and appeared for some time stationary. As electricity is a 

 great cause, ever active, in producing ozone, we might a priori infer 



