THE BLOOD. 71 



into an isomeric or polymeric modification-, called by him parahcemo- 

 globin. Oxyhaemoglobin is insoluble in ether, chloroform, benzol, 

 and carbon disulphide. 



A solution of oxyhaemoglobin in water is not precipitated by 

 many metallic salts, but is precipitated by sugar of lead. On heat- 

 ing the watery solution it decomposes at 60 to 70 C., and it splits 

 off albumin and haematin. It is also decomposed by acids, alkalies, 

 and many metallic salts. It gives the ordinary reactions for albu- 

 min with the albumin reagents which first decompose the oxyhaemo- 

 globin with the splitting off of albumin. 



The oxyhsemoglobin may, when it is gradually oxidized, act as 

 an " ozone exciter " by the disjoining of neutral oxygen, making the 

 oxygen active (PFLUGER). It may also have another relation to 

 ozone, since it has the property of an " ozone transmitter " in that 

 it causes the reaction of certain reagents (turpentine) containing 

 ozone upon ozone reagents such as tincture of guaiacum (SCHON- 

 BEIN, His). According to KOWALEWSKY, it is not ozone but an 

 oxidation-product of turpentine that we have to deal with; but this 

 question requires further proof. 



A sufficiently dilute solution of oxyhaemoglobin or arterial blood 

 shows a spectrum with two absorption-bands between the FRATJN- 

 HOFER lines D and E. The one band a, which is narrower but 

 darker and sharper, lies on the line D\ the other, broader, less de- 

 fined and less dark band /?, lies at E. These bands can be detected 

 in a. layer of 1 cm. of a 0.1 p. m. solution of oxyhaemoglobin. In a 

 still weaker dilution the band /? first disappears. By increased con- 

 centration of the solution the two bands become broader, the space 

 between them smaller or entirely obliterated, and at the same time the 

 blue and violet part of the spectrum is darkened. The oxyhaemo- 

 globin may be differentiated from other coloring matters having a 

 similar absorption-spectrum by its behavior towards reducing sub- 

 stances. (See below.) 



A great many methods have been proposed for the preparation 

 of oxyhaemoglobin crystals, but in their chief features they all agree 

 with the following method as suggested by HOPPE-SEYLER : The 

 washed blood-corpuscles (best those from the dog or the horse) are 

 stirred with 2 vols. water and then shaken with ether. After 

 decanting the ether and allowing the ether which is retained by 



