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of Edinburgh, Session 1873 - 74 . 
ozonised oxygen, the heart was found pulsating, and, as in the other 
cases, engorged with venous blood. 
On breathing an atmosphere of ozonised oxygen ourselves, the 
chief effects observed were a suffocating feeling in the chest, a ten- 
dency to breathe slowly, an irritation of the back of the throat and 
of the glottis, and a tingling sensation, referred to the skin of the 
face and the conjunctivas. The pulse became feebler. After breath- 
ing it as long as it was judicious to do, say for five or eight minutes, 
the suffocating feeling became stronger, and we were obliged to 
desist. The experiment was followed by violent irritating cough 
and sneezing, and for five or six hours thereafter by a sensation of 
rawness in the throat and air-passages. 
The action of ozone on several of the chief physiological systems, 
and on various tissues, was also examined. 
1. On the Circulation. — By a suitable apparatus, a frog was im- 
prisoned in a chamber through which a stream of ozonised air, or 
of ozonised oxygen, passed, while at the same time the web was so 
placed under a microscope that the circulation in the smaller ves- 
sels and capillaries could be readily observed. The result was nega- 
tive, inasmuch as no appreciable acceleration or retardation of the 
current of the circulation was seen. 
2. On the Reflex Action of the Spinal Cord. — This function was not 
affected to any appreciable degree. 
3. On Muscular Contractility. — By means of a myographion, the 
work done by the gastrocnemii of frogs, subjected to the action 
of ozone, was noted. The muscles were stimulated by a single 
opening or closing induction shock produced by Du Bois Reymond’s 
apparatus and a Daniell’s cell. The result was that the contractility 
and work-power of the muscle were found unaffected, as far as could 
be appreciated. 
4. On the Blood. — When a thin layer of human blood on a slide 
is exposed to the action of ozone, the coloured corpuscles become 
paler, lose their definite outline, and if exposed for a period of five 
or ten minutes to the action of the current, they are dissolved, and 
a mass of molecular material is seen. The coloured corpuscles of 
the frog show, after the action of ozone, the formation of a nucleus. 
By prolonged exposure many of the nuclei apparently pass out of 
the substance of the corpuscle, numerous free nuclei are seen, and 
