CHEMICAL SCIENCE. 241 



ware manufactured, the grinding of this material is productive of 

 intolerable foetidity. In an atmosphere thus imbued with foetidity, 

 chemical effects ought to be observable, if there be any connection 

 between the source of this fcetidity and that produced by ozonizing 

 agents. It is long since it occurred to me that as the phenomena of 

 light, under all the various hues which it is capable of producing, are 

 ascribed to the undulatory affections of an ether pervading the uni- 

 verse ; so the still greater variety of odors which influence our olfactory 

 nerves may be due to vibratory agitation of the same medium. Con- 

 sistently it may be conceived that the odor produced during ozonifica- 

 tion, during the attrition of quartz, is due to an odoriferous ethereal 



agitation. 



OBSERVATIONS ON OZONE. 



DR. POLLI forms his ozometer by dipping papers in the following 

 solution : starch, 10 parts ; iodide of potassium, 20 ; water, 400 ; pro- 

 vided they are kept folded up or in close vessels, they preserve their 

 power for months. When one of these slips was suspended by a thread 

 in the air, outside the window, it became strongly colored in a few 

 hours ; while a similar one, suspended within doors, remained white 

 for days, and only began to be colored after several ; and this was the 

 case in whatever part of the house it was suspended, as in well-ven- 

 tilated passages and corridors. The slip exposed out of doors became 

 still more speedily and deeply colored when freely exposed at a distance 

 from the house. To ascertain how far a frequent renewal of the body 

 of ah* might influence the appearance, one of two slips, placed out of 

 doors, was fastened firmly at both ends, and the other allowed to fly 

 about freely. Both became rapidly colored, and with equal intensity. 

 A portion of a slip was introduced within a phial, and a portion 

 allowed to remain externally, the air, however, having access to the 

 former. On exposure to the atmosphere, the portion external to the 

 phial became intensely colored, while that within remained unchanged, 

 so that mere vicinity of another body prevents action. If ozone irri- 

 tates the air-passages, we can see, from the above experiments, the 

 importance of invalids suffering from a delicate state of them, keeping 

 the house, or protecting themselves when they quit it. So, too, some 

 light is thrown upon the injurious operation of drafts and currents of 

 air, by the fact that strips, suspended near cracks and fissures within 

 doors, only become colored opposite those. If slips of paper are cov- 

 ered before exposure with layers of silk, wool, linen and cotton, of the 

 same size and thickness, those covered by the silk, wool, and linen, 

 remain uncolored, while those covered by the cotton become colored. 

 If a piece of linen and a piece of cotton are immersed in a solution of 

 starch and iodide of potassium, and then exposed, the cotton becomes 

 deeply colored, while the linen becomes so only feebly, after a long 

 time. Will this aid in explaining the irritating effect of cotton hand- 

 kerchiefs compared to linen, when applied to the nose and eyes during 

 catarrh? Humidity does not impede the appearance of ozone. The 

 direct rays of the gun favor it. and it is less developed if these are 



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