APPENDIX — ^ACTION OF DRUGS ON OXIDATION. 649 



Fhilosophical Transactions of the Boyal Society for 1858, 

 pp. 589-625; and to Dr. Harley's paper on the Action of 

 Alkaloids, etc., in the Transactions for 1864, p. 687. 



The object of adding the drug to the blood before arterial- 

 ising, as in 6, and after arterialising, as in 7, is to discover 

 whether it prevents the blood from taking up oxygen in the 

 former experiment, or of giving it off in the latter. Normal 

 blood has the power to produce ozone, or to withdraw it from 

 substances which contain it, and transfer it to others which 

 are easily oxidised. Arterial respiration may be modified, and 

 the process of oxidation diminished, by the action of certain 

 substances which deprive blood of this power. The usual test 

 for ozone is fresh tincture of guaiac (1 part guaiac to 6 of 

 alcohol), which is oxidised by it with extreme rapidity. It 

 shows the progress of the oxidising process with great dis- 

 tinctness by the blue colour which it assumes. A few drops 

 of tincture of guaiac are put upon a piece of porous paper, 

 allowed to become almost quite dry, and a drop of blood or 

 solution of haemoglobin is then placed on it. In a few minutes, 

 the drop becomes surrounded by a blue ring from the forma- 

 tion of ozone and the oxidation of the guaiac in its neighbour- 

 hood. The formation of ozone is independent of the oxygen 

 contained in the haemoglobin ; and carbonic-oxide-hsemoglobin 

 will produce it as well as oxyhaemoglobin, provided air be 

 present. When the haemoglobin itself contains oxygen in the 

 form of oxyhaemoglobin, the presence of air is not necessary 

 to the reaction. The oxidation of guaiac by means of blood 

 alone is, however, not nearly so easily observed as when 

 another substance containing ozone is added to it, such as 

 peroxide of hydrogen or oil of turpentine which has been kept 

 for some time. The haemoglobin takes the ozone from these 

 substances, and yields it up again to the guaiac. 



The method adopted by Binz, in order to test the influence 

 of drugs on this ozonising power of haemoglobin, is to take a 

 mixture of tincture of guaiac with a few drops of ozonised oil 

 of turpentine, and divide it into two parts. A few drops of 

 a solution of the drug to be tested is added to one of them, 

 and a few drops of solution of haemoglobin then dropped into 



