6o JOURNAL AND PROCEEDINGS. 



Since the atmospheric oxygen is in the form of molecules, it will be 

 impossible for it to bleach any substance which is not capable of 

 breaking up the molecule into its atoms; this, it appears, the 

 coloring matter is not capable of doing, hence no bleaching of it 

 is effected by atmospheric oxygen. We are thus forced to the con- 

 clusion that whatever the constituent of the air is, which causes 

 materials to be bleached, it is not the oxygen contained in it. 

 Nitrogen, water vapor and carbon dioxide, the other chief con- 

 stituents of the atmosphere, from their very nature cannot be looked 

 upon as bleaching agents. 



Nitrogen is too chemically inactive, while water vapor and carbon 

 dioxide are exceedingly stable, and thus will not readily lend them- 

 selves to the reactions necessary to effect the required changes. 



There are a number of other materials, traces of which are 

 present in the air, but of all these the only one which is likely to 

 bring about the changes necessary to effect bleaching is ozone. 

 Ozone is composed of oxygen atoms only, but since it presents 

 properties different from those of oxygen, we must look for an ex- 

 planation of this difference iu the arrangement of the atoms. 



For reasons, which it is unnecessary to give here, we consider 

 the oxygen molecule as made up of two atoms, while the ozone 

 molecule is made up of three. Further, while the oxygen molecule 

 is difficult to decompose, the ozone molecule is quite unstable, so 

 that its atoms readily separate and reunite themselves in molecules 

 of two atoms each or as ordinary oxygen. While passing from one 

 form to the other the oxygen is momentarily in the form of atoms, 

 as it is when it is liberated by chlorine from water, at which time it 

 effected the bleaching usually attributed to chlorine. 



It is one of the principles upon which the science of chemistry 

 is based, that whatever a material will effect at one time it will 

 always effect under like conditions. Since, as we have shown, 

 nascent oxygen will bleach when liberated from water by chlorine 

 it will also do so when liberated from ozone, by whatever agency. 

 The ozone of the air then may be considered as a bleaching agent. 

 The only difficulty in the way of considering it as the substance 

 which bleaches materials exposed to the air is the fact that it is 

 present in such minute quantities that it is almost incredible that it 

 can do all the work usually ascribed to it. 



The sun's rays are also capable of bringing about chemical 



