144 REPORT 1860. 



that the inhalation of oxygen in the pure state, by giving rise to a greater absorption 

 of the gas, sets up an increased oxygenation in the body,- — hypercausis, and inflam- 

 matory conditions, general and local. This view, first promulgated by Dr. Beddoes, 

 and followed up by many contemporary writers, was probably the basis of the 

 chemical nomenclature of disease invented by Baume, in which disorders were 

 divided into those of oxygenation, of calorification, hydrogenizatiou, azotification, 

 and phosphorization, with remedies of the same names for their treatment. 



A second conclusion as to the influence of oxygen on animals, intimated (also 

 from experiment) that oxygen, wheu inhaled in the pure form, is even less active 

 than as it exists diluted in common air ; that, instead of increasing the combustion 

 of the body and its activity, it lessens these, and that animals exposed to it too long 

 die from coma attended with a steady and uudiminishing exhaustion. The idea 

 that less oxygen is absorbed wheu the gas is breathed in the undiluted state was 

 supported by Davy : the statement that the gas destroys by narcotic exhaustion 

 was doubtfully suggested by Priestley, and openly by Broughton. For years this 

 view of the question has been the one most commonly taught in this country. 



The last conclusion that had been drawn from experiment relative to the effects 

 of pure oxygen was, that it has no injurious influence on life. Lavoisier, in his later 

 experiments, seems to have drawn this inference, and Regnault has greatly con- 

 firmed it. 



In 1852, with these conflicting data before him, those of Regnault only excepted, 

 Dr. Richardson commenced an inquiry into the whole subject, which he had con- 

 tinued, with intermissions, to the present time. The author here narrated his earlier 

 experiments, from which he came to the conclusion that animals of active respiration, 

 as dogs, cats, and pigeons, on being subjected to a constant stream of freshly made 

 oxv°'en, become subject to inflammation, owing to the rapid destruction of the 

 tissues, — hypercausis. In further experiments, he found, however, that his rule was 

 not common to all animals ; for rabbits and frogs were kept by him even for weeks 

 in oxygen without apparent injury. On the data, therefore, he gave the following 

 as the first major proposition of his paper: — 



The influence of pure oxygen, as an excitant, differs according to the animal ; 

 beinc most marked in animals of quick respiration and high temperature, and least 

 marked or nil in those of feeble respiration and lower temperature. 



Up to 1856 the author had felt assured that oxygen, when it destroys life in the 

 actively breathing animals, does so by causing a too rapid oxidation of tissue and 

 the so-called inflammatory process ; and he believed that the symptoms of narcotism 

 and paralysis, named by Broughton, were due without doubt to one or other of 

 two possible errors, introduction of carbonic acid, or modifications of the air-pressure 

 exerted on the animal. In 1857 he began to suspect that his view was not strictly 

 correct ; but he had no proof either one way or the other until the present year, 

 when a new observation opened a new phase of the question. Having made on one 

 occasion forty gallons of oxygen, and having, by the side of the reservoir containing 

 the oxygen, another reservoir of equal size filled with water, Dr. Richardson deter- 

 mined, in order to economise both labour and material, to collect the oxygen from 

 the supplying reservoir, after it had passed through the chamber containing the 

 animals. He arranged also to wash the oxygen in alkaline solution until it was 

 free of carbonic acid altogether, to pass it over sulphuric acid to remove any am- 

 monia, and finally to charge the second reservoir with it and to use it again, 

 sending it thus backwards and forwards from one reservoir to the other until it 

 was all used. 



"When the apparatus was complete, he placed four warm-blooded animals, a cat, 

 a dog, a pigeon, and a rabbit, with two frogs, in a large chamber, and at 11 o'clock 

 in the morning commenced the transference of the oxygen, passing it through the 

 chambers at the rate of 2000 cubic inches per hour. In six hours the whole of 

 the primitive oxygen, minus nearly 1000 cubic iuches which had been lost in 

 respiration, was transferred into the second reservoir. The gas was now tested, 

 and havino- been found to give no reaction to lime-water, it was driven back 

 through the chamber and washed again thoroughly with potash, to be received 

 once more into the reservoir number one. As the first charge of oxygen was passing 

 throuo-h the chamber, there were exhibited no signs different from those of excitement, 

 which bad before bee« seen; but as the second cbarge passed through, all the 



