Chemistry and Physics. 475 



ozone and hydrogen peroxide react thus: O s + H 2 O a = H 2 + (0 2 ) 2 ; 

 whereas on the single bond theory O s -f- (H 2 2 ) 3 = (H. 2 0) 3 + (0,) 3 

 would represent the reaction. In these cases only one atom of 

 the oxygen appears to be active. 80 potassium tetroxide which 

 is ordinarily written K-O-O-O-O-K, actually absorbs oxygen in 

 spite of its large content of this substance, and reduces readily 

 acid solutions of potassium permanganate. None of its oxygen 

 atoms therefore are active, and on treatment with acid it decom- 

 poses into hydrogen peroxide and ordinary oxygen, indigo-sul- 

 phuric acid, if present in the solution, remaining unaffected. 

 Hence the author writes its formula K . O = O . O = O . K. Such 

 substances as these, which are not active oxidizers, the author 

 thinks should not be called peroxides. He has proposed the name 

 "holoxides" for them, to indicate that the oxygen atoms are 

 doubly united in them and exist as a molecule. While water is a 

 compound of one atom of oxygen, hydrogen holoxide is a com- 

 pound of one molecule of oxygen with two atoms of hydrogen. 

 He suggests too that oxygen may be trivalent; and in that case 

 would write the constitution of hydrogen holoxide H-0 = O-H, 

 of potassium holoxide K-0 = 0-0 = 0-K. — Ber. Berl. Chem. 

 Ges., xxvi, 1471, 1476, June, 1893. g. f. b. 



3. On the formation of Ozone at high Temperatures. — The 

 peculiar odor of the oxygen made from a mixture of potassium 

 chlorate and manganese dioxide has long been recognized, and 

 has generally been confounded with that of chlorine. Schonbein, 

 Chevreul, Poggendorff and others mention chlorine as being 

 evolved in this reaction and Marignac says he obtained 3 mgrms. of 

 silver chloride from the oxygen evolved from 50 grams potassium 

 chlorate. Brtjnck, reasoning that if the chlorate really gave off 

 chlorine on heating, free alkali would be formed and should exist 

 in the residue either as such or in the form of potassium manga- 

 nate, has carefully examined this residue and tiuds it to be com- 

 pletely colorless and perfectly neutral. This fact, taken in con- 

 nection with the property possessed by the odorous gas, even 

 after washing with strong potash solution, of bluing paper mois- 

 tened with potassium iodide and starch, led the author to assume 

 thai this gas must be ozone. Experiments made with ozonized 

 oxygen showed that ozone may exist not only at the temperature 

 of decomposition of potassium chlorate but even for a short time 

 at a red heat; only 80 percent of a gas thus prepared being 

 destroyed by passing it through a combustion tube heated to 

 350°. The quantity passing did not materially diminish when 

 the temperature of the tube reached a dull red. Comparative 

 tests were made between oxygen evolved from the chlorate mix- 

 ture and oxygen ozonized in a Siemens tube. Both samples set 

 iodine free from neutral potassium iodide, oxidize alcohol to alde- 

 hyde, lose their properties when passed over manganese dioxide 

 at ordinary temperatures, and are unchanged by washing with 

 strong potash solution. Though these results establish the iden- 

 tity of the odorous gas with ozone, yet it differs in some particu- 



Am. Jocr. Scl— Third Series, Vol. XLYI, No. 276.— Dec, 1893. 

 33 



