The Physiological Influence of Ozone. 



405 



Filipow* found -weak concentrations had no effect on men or animals, while 

 a higher concentration of ozone caused irritation of the respiratory tract. 



Schultzf confirmed this irritative effect, and found long-continued breathing 

 of ozone caused pathological changes, particularly in the lungs, which were 

 the cause of death. Schultz considered that the ozone passed into the blood 

 and injured the lung secondarily. Bohr and Maar| overthrew this supposi- 

 tion by the ingenious experiment they devised of making one lung breathe 

 ozonised air and the other normal air. They found this lung remained 

 normal while the ozonised lung became cedematous. 



Using a concentration of ozone which produced no visible change in the 

 pulmonary structure, these observers found that it caused a diminished 

 uptake of oxygen; the other lung compensated for the deficiency by an 

 increased uptake. This occurred in both cold-blooded (tortoise) and warm- 

 blooded animals. In the former the initial effect of ozone was occasionally a 

 slightly increased oxygen uptake. If the inhalation of ozone were continuous, 

 the increased uptake by the lung ventilated with normal air finally fell away 

 and became deficient; this occurred sooner in the mammal than in the 

 tortoise. 



The C0 2 output was also diminished, but not so markedly as the oxygen 

 uptake, thus the respiratory quotients often rose over 1. The effect of 

 ozone on the respiratory exchange came on gradually, and with weak 

 concentrations often reached its height after the cessation of the ozone 

 inhalation — there was, in fact, an after-effect which took some little time to 

 pass off. The effect was not modified by a preliminary division of the vagi 

 and pulmonary sympathetic nerves. 



The blood of the ozonised animal had no toxic effect when transfused into 

 another. Bohr concluded that the effect was primarily on the lungs, and as 

 the oxygen uptake was affected more than the C0 2 output, he claimed that 

 his results supported his view that the pulmonary epithelium by its secretory 

 activity controlled the passage of the respiratory gases. Butte and Peyron§ 

 likewise record that ozone when inhaled diminishes the metabolism. 



One of the obstacles in the way of investigation has been the difficulty of 

 obtaining pure ozone free from oxides of nitrogen, and another has been the 

 want of an accurate method of estimating the concentration of ozone. 

 There has been devised lately an ingenious apparatus for producing ozone, 

 which eliminates the production of the oxides of nitrogen, and allows the 



* 'Arch. f. d. Ges. Physiol.,' vol. 34, p. 335. 

 t 'Arch. f. exper. Path.,' 1882, vol. 29, p. 364. 

 \ ' Skand. Arch. f. Physiol.,' 1904, vol. 16, p. 41. 



§ 'Comp. Rend. Soc. Biol.,' vol. 46 ; 'Progres Medical,' 1894, Xo. 30, p. 61. 



