CHEMICAL SCIENCE. 211 



generating ozone for removing those noxious effluvia which arise 

 from the processes of animal life and putrefaction. 



Mr. Glaisher then proceeded to relate the results of experiments 

 in ozone, made by him in London at the time of the cholera, 1854, 

 which were, that where the test-papers were discolored, there 

 death was extremely rare, and vice versa. 



Does ozone exist in the atmosphere ? That is the question asked 

 by Admiral Berigny, of the French Academy of Sciences, who, 

 after having patiently made what he conceived to be ozonometric 

 observations for the last ten yeai's, and assisted M. Le Verrier in 

 selecting stations for similar observations all over Paris, and in every 

 department of France, has been brought at last to doubt whether 

 the observations are good for anything ; so he beseeches the Acad- 

 emy to appoint a commission to settle definitively, — 1. Whether 

 ozone exists in the atmosphere ? 2. Whether Schonbein's or any- 

 body else's papers prove the jiresence of electrized oxygen? and, 

 lastly, whether an easy and reliable method of detecting it could not 

 be devised ? The Academy ai^pointed a commission composed of 

 Chevreul, Dumas, Pelouze, Foviillet, Boussingault, Le Verrier, Val- 

 liant, Fremy, and E. Becquerel, whose report will no doubt scat- 

 ter popular notions on atmospheric ozone to the winds. 



To say the truth, the evidence in favor of the presence of ozone 

 in the atmosphere is, as M. Fremy showed to the Academy, of 

 the most doubtful character. M. Fremy said that he knew of only 

 one certain test for ozone in the air, and that was the oxidation 

 of silver, by passing a current of moist air over the metal ; and 

 this test he had api3]ied many times without any indication of 

 ozone. We are very fixr from being acquainted, he said, with all 

 the bodies held in susi^ension in the air, and, consequently, igno- 

 rant of the action they may exert on iodide of potassium. May 

 not, he asked, this salt become alkaline, or set free iodine under 

 other influences besides that of ozone ? He did not deny the fact 

 of its presence, but he asked a positive proof of it. Such a proof 

 is required ; for, seeing that ozone is instantly destroyed by or- 

 ganic matters, and absorbed by nitrogen, it is difficult to under- 

 stand how such a body can continue to exist in the air, which con- 

 tains precisely the elements which would at once change the 

 ozone. As regarded the test-papers he asked, what use there 

 could be in a reagent which was affected not only by ozone, but 

 by the oxygen compounds of nitrogen, by oxygenated water, by 

 ammonia, by formic acid, by essential oils, by the acid j^roducts 

 of combustion, by dusts, — in a word, by all sorts of things which 

 are held in suspension in the air. — Dniggists'' Circular, 1866. 



Our actual knowledge of the volumetric relations of oxygen, 

 says M. Soret in a note presented to the French Academy, is lim- 

 ited to the following facts : 1. That ordinary oxygen diminishes 

 in volume when a part is converted into ozone. 2. That when 

 ozonized oxygen is treated with iodide of potassium or other oxi- 

 dizable matter, the ozone disappears without any alteration in the 

 volume of the gas. 3. That under the influence of heat, ozonized 

 oxygen undergoes an expansion equal to the volume that the part 

 absorbable by iodide of potassium would occupy. Regarding a 

 molecule of ordinary oxygen as composed of two atoms of 00, 



