CHEMICAL SCIENCE. 239 



lamp, and then introduced into the vapor, litmus paper, held above the 

 rod, becomes at once reddened, and the iodide of potassium paper 

 intensely blue. In the oxidation of ether, at low temperature, ozone is 

 evolved. Essential oils are thickened by long exposure to light and air ; 

 they become ozonized and their properties changed. This was illus- 

 trated by reference to oil of turpentine. Freshly rectified and pure oil of 

 turpentine was proved, by admixture with sulphate of indigo, to have no 

 bleaching power. A small quantity of oil, which had been exposed to 

 air and light, destroyed the color in a few minutes, like chlorine. 



It cannot be doubted that ozone exerts an important influence on 

 the atmosphere, and, therefore, on the health of animals and vege- 

 tables. If it be an allotropic condition of oxygen, it is impossible to 

 say what regulates the conversion of the one condition of the element 

 into another. Chemical agency, electricity, and magnetism, may be 

 the constant sources of its production. Decay, disease, and death, 

 affecting alike animals and plants, may be the means by which ozone 

 is consumed ; but what power is it that regulates the quantity produced, 

 and so adjusts it that it shall conduce to health and life ? This is a 

 profound mystery. It is obvious, from what is already known, that by 

 an over-conversion of oxygen in the atmosphere into this allotropic 

 condition, every living thing would perish ; and it is not improbable 

 that the arterialization of blood may be due, not to oxygen in its ordi- 

 nary, but in its allotropic state. 



The oxidation of the metallic sulphurets by ozone throws a curious 

 light on the probable cause of the destruction of photographic draw- 

 ings. If any sulphuret of silver be left in the finished drawing, the 

 drawing is slowly bleached, and the sulphuret converted into sulphate 

 of silver. In drawings which have been framed, the change is ob- 

 served to commence on the external margin, and slowly spread to tho 

 centre. Medical Gazette, and London Chemist. 



ON THE ORIGIN OF THE OZOXIC ODOR PRODUCED BY THE ATTRITION OP 



SILICEOUS SURFACES. 



AT a meeting of the Franklin Institute, April, 1851, Dr. Hare sub- 

 mitted an apparatus for ascertaining whether the phenomena attending 

 the attrition of pieces of silex, when rubbed together, had anything in 

 common with the supposed new halogen body, ozone. In regard to the 

 odor produced in the manner referred to, nothing can be more unac- 

 countable. That it cannot be due to any organic matter entering into 

 the composition of the quartz, must be evident ; in the first place, 

 because the smell is produced by the purest and most transparent 

 specimens of rock crystal in the regular form, and, in the second place, 

 because ignition to bright redness does not destroy, nor even diminish, 

 the property. One thousand grains of cellular horn-stone or French 

 burr, on ignition, as above stated, lost five grains that is to say, one 

 half per cent, of its weight, without, however, losing the property of 

 producing light or smell. It occurred to me that it might help to 

 remove the mystery were an apparatus constructed by which the attri- 

 tion of siliceous masses might be made more efficaciously than could be 



