228 ANNUAL OF SCIENTIFIC DISCOVERY. 



By dilution of the blood; 3. By the activity of the oxygen; 4. By 

 the presence or absence in the blood of bodies which stop combina- 

 tion. On the point of dilution of oxygen, Dr. Richardson stated 

 that a certain measure of dilution was required not because the body 

 consumed too quickly in pure oxygen, but because neutral oxygen 

 would not combine with the carbon of the blood unless it were diluted. 

 In atmospheric air the dilution is just sufficient to do no more than al- 

 ter combination ; and the quantity of oxygen may be increased with 

 absorption at 60 to 65 Fahr., if the oxygen is raised in amount to 

 three parts of the gas to two of nitrogen. Beyond this, the combining 

 power is reduced, and oxygen not absorbed. Hence animals die in 

 the gas as it approaches the pure state ; they die not by a narcotic 

 process, but by a process of negation. On the point of dilution of the 

 blood, the author said that blood possessing a specific gravity of I'O.JS 

 seemed to have most steady power in absorbing oxygen, as it existed 

 in common air ; by increasing the quantity of water in the blood to a 

 limited extent, say until it lowered the blood to 1'OGO, the absorption 

 of oxygen is increased to a maximum, and after that it is diminished. 

 Below 1'055 the absorption of oxygen steadily declines. In respect 

 to the activity of the oxygen, the most differing results are obtained 

 according to the activity. If the oxygen be made fresh from chlorate of 

 potassa it sustains life even in the pure form, and the activity of the 

 lunctions is increased ; if electric sparks are passed through the gas, 

 or the gas be heated 100, the same is the fact. On the other hand, 

 if the gas is exposed to ammonia, to decomposing animal matter, or 

 even to living animals, over and over again, it loses, even when 

 diluted, its activity, and no longer combines with the blood. In 

 reference to the last point, Dr. Richardson said that there were con- 

 ditions of blood in which the power of absorption was limited. Al- 

 cohol, chloroform, opium, and certain alkaline products formed in the 

 blood in disease, prevented absorption of oxygen, and death not un- 

 commonly took place from this cause. Great increase of water did 

 the same. After this description, Dr. Richardson added that the 

 question had often been put, whether the inhalation of oxygen could 

 be usefully applied in the treatment of disease. Priestley, Beddoes, 

 Hill, and many of those who lived when oxygen was first discov- 

 ered, had formed the most sanguine expectations on this point; 

 they saw before them an elixir, if not tlic elixir vitas. Chaptal, in 

 speaking of the. effects of oxygen in consumption, said of it : it raises 

 hope, but, alas ! it merely spreads flowers on the path to the tomb. 

 Since then various opinions of the extremes! kind have been expressed, 

 the differences having arisen from the entire want of order that has 

 teen followed in the inquiry. One man has used pure oxygen, the 

 other diluted ; the one active, the other negative oxygen. The one 

 has given the gas to anaemic people, whose blood is surcharged with 

 water ; the other to diabetic or choleric persons, whose blood is of 

 high specific gravity : the one has given it heated, the other at the tem- 

 perature of the day. If even a stick of phosphorus were exposed to 

 oxygen under such varying conditions the phenomena obtained would 

 be as variable as those which had been registered in physic regarding 

 oxygen as a remedy. The difficulties of arriving at uniform results 

 had been almost insurmountable from another cause, that of obtaining 



