8io 



THE POPULAR SCIENCE MONTHLY. 



Ozone, or some agent nearly resembling it, is often produced when 

 oil of turpentine is exposed to the air, and this circumstance may per- 





'sis. 



"--=-= r"^ #=^ 



'safc^ 



igisiP^ 



Fig. 3. Ficits Elastica ; a Specimen growing in the Open Air at Paris. 



haps explain the destructive influence which oil of turpentine occasion- 

 ally exercises on India-rubber. 



Exposure to sunlight often causes the destruction of India-rubber, 

 either converting it into a soft and sticky substance, or into a hard 



