Oxygen. Dephlogisticated Air. An essential constituent of all living bodies. Water contains § of its weight of Oxygen, and the atmosphere about per cent. by weight. Sp. Gr. 1.1057. Eq. Wt. 8. Combined with other elementary bodies, it forms oxides. Prof. Faraday * has shown that it is magnetic.

Med. Prop. and Action. Stimulant (?). When pure Oxygen is inhaled. it increases the force and frequency of the pulse, causes exhilaration of spirits, and a gentle diaphoresis. These effects soon pass off. Animals confined in an atmosphere of pure Oxygen soon die, and after death the blood, both arterial and venous, is found of a bright scarlet hue. very liquid, and repidly coagu-lated. (Pereira.) According to Dr. Richardson, Oxygen proves fatal, not by the introduction of a poison into the system, but by a negation or withdrawal of some principle extant in the primitive Oxygen which is essential to life. MM. Demarquay and Leconte. from a series of experiments on the effects of Oxygen on man, have arrived at the following conclusions: - 1. Oxygen applied locally to wounds (by a special apparatus), whether recent or old, causes little pain, but ultimately gives rise to a more or less vivid reaction. It rapidly modifies, and in some cases removes, the inflammatory or con tive redness which surrounds wounds. 2. It may be injected into the mucous or serous cavities without ill effects. In one case, Hydrocele underwent a cure a ter its injection. 3. It may be inhaled in doses of 20 to 40 litres at one time daily, without inducing any accident. 4. Its essential property is to increase the strength, stimulate the assimilatory powers, and develop the appetite. They believe it to be especially indicated in anAemic condition* and certain diatheses, as Diphtheritis, Syphilis, and Diabetes. They believe it to be contia-indicated febrile states, except under certain diathesic conditions, as croup; in deep-seated inflammatory action and visceral lesions; in diseases of the heart and large vessels; in neuralgia unconnected with antenna, and where there is a disposition to hAemorrhage. The value of Oxygmated Water as a therapeutical agent has been examined by M. Ozanum.§ The Water is distilled, and then charged with Oxygen under high pressure. He finds that it improves the condition of the blood in asthma, cyanosis, and other diseases in which that fluid is impaired or deficient. It possesses an oxidizing or metamorphic influence in cases where the organic products are arrested in their development, as Glycosuria, Govt, Uric and Oralic Gravel and perhaps Saofula. It exerts a regulating and exciting action on the brain and thyroid gland, and hence is of use in Goitre and Cretinism.

2040. Therapeutic Uses

In Asphyxia from deficiency of Atmospheric Air, from breathing noxious Vapours, from the Inhalation of Chloroform or Ether,|| and in the Asphyxia of Infants,¶ the inhalation of Oxygen gas has been recommended by various authorities. In some cases it proved successful, but in others it signally failed.

2041. Other Diseases

In Phthisis, Spasmodic Asthma, and other Chronic Pulmonary complaints, the inhalation of Oxygen has been productive of occasional benefit; but no reliance is to be placed upon it. Fourcroy** employed it in twenty cases of Phthisis, and found that in all it was prejudicial, hastening the progress of the disease, and increasing the febrile action. In Constipation depending upon torpid and congested liver, with chronic derangement of the biliary secretion, Dr. S. B. Birch* states, that he has often found the proper exhibition of Oxygen produce an almost immediate effect Dr. J. Hooper records an intractable case of Neuralgia cured by the inhalation of Oxygen on the plan proposed by Dr. Birch: he likewise mentions a case of Asthma in which the same treatment afforded great relief. Local baths of Oxygen gas are highly spoken of by M. Laugier in the treatment of Senile Gangrene. Dr. Ramskill has tried the effect of the inhalation of Oxygen in various chronic forms of Paralysis, Spasm, and Epilepsy. In a case of Epilepsy occurring in connection with Syphilitic Cachexia, the inhalation of Oxygen two or three times a day seemed productive of benefit. The inhalation should be stopped on the accession of giddiness or other uncomfortable symptoms. For children, Dr. Ramskill adopts the plan of making them inhale atmospheric air through a glass inhaling apparatus one-third full of solution of Peroxide of Hydrogen. The solution must be well charged with Oxygen; and to facilitate its being given off, the inhaling apparatus is gently agitated by an attendant during the process, and a hot, moist cloth is kept wrapped round it. The inhalation is continued until some sensible effect is produced on the pulse or the feeling of the patient. The slightest feeling of giddiness is considered a sign of sufficient action. §

* Med. Gaz., Nov. 29, 1850. Brit. Med. Journ., July 14, 1860. Med. Times and Gaz., Feb. 27, and March 26, 1864. § Year-Book of Sydenham Soc., 1862, P 173. || Mr. Robinson, Lancet, 1848.

¶ Chaussier, Hist, de la Soc. Roy. de Med.p. 346.

** Ann. de Chimie, No. iv. 1790.