138 M. Schonbein on Ozone and Ozonic Actions in Mushrooms. 



more or less, according to the degree of temperature at which 

 the oxygen happens to be disengaged from those compounds. 



The lower that degree, the larger the quantity of mixed with 

 ; though I must not omit to state, that in all cases that quan- 

 tity happens to be exceedingly small in comparison to that of O 

 obtained at the same time. The best means of ascertaining the 

 presence of is the alcoholic solution of guaiacum recently pre- 

 pared. You know that does not in the least change the colour of 



that resiniferous liquid, whilst free or PbO + 0,&c.have thepower 

 of colouring it deep blue. The blue matter is, as I think I have 



proved it, nothing but guaiacum +0. Now if you heat the 

 purest oxide of gold, platinum, silver, mercury, the peroxides of 

 manganese, lead, &c., in fact any substance yielding oxygen, 

 within a small glass tube into which you had previously in- 

 troduced a bit of filtering-paper impregnated with the said 

 guaiacum solution, you will see that bit of paper turn blue as 

 soon as the disengagement of oxygen begins to take place ; and 

 all the circumstances being the same, you will further perceive 

 that the paper is coloured most deeply and rapidly by the 

 oxygen eliminated from that oxy-compound which requires the 

 lowest temperature for yielding part or the whole of its oxygen. 

 Thus the oxygen disengaged from the oxides of gold, pla- 

 tinum and silver, acts more energetically upon the guaiacum 

 solution than does the oxygen eliminated from the oxide of 

 mercury, the peroxide of manganese, &c. I trust these results 

 will be obtained in the Royal Institution just as well as I get 

 them in the laboratory of Bale, or else my discovery will be a very 

 poor thing. As there cannot, I should think, be any doubt that 

 all the oxygen, contained, for instance, in the oxide of silver 

 previously to that compound being decomposed by heat, exists 

 but in one state, be that state what it may, how then does it 

 happen, we may ask, that at the same time two different sorts 



of oxygen, O ond 0, are disengaged from the compound named ? 

 The answer to this question seems to me to be, that one of the 

 two kinds of oxygen eliminated must be engendered at the ex- 

 pense of tlie other ; or to speak more correctly, that during the 

 act of the elimination of oxygen from the oxide of silvei", part of 

 that oxygen suffers a change of condition. Now as the oxides 

 of gold, silver, &c. enjoy the power of colouring blue the 



guaiacum solution, just as free O does, I draw from that fact 

 the conclusion, that the condition of the oxygen contained in 

 the oxides of gold, silver, &c. is the ozonic one; and further 



infer, that by far the greatest portion of that O, under the in- 

 fluence of heat, is transformed into O. Why the whole of the 



