274 THE BLOOD. 



decomposed by acids, alkalies, and many metallic salts. It gives the 

 ordinary reactions for proteins with those protein reagents which first 

 decompose the oxy haemoglobin with the splitting off of protein. Oxy- 

 ha3moglobin, like the other blood-pigments, has a direct oxidizing action 

 upon tincture of guaiacum. It has, on the other hand, like all blood- 

 pigments containing iron, the property of an " ozone transmitter " in 

 that it turns tincture of guaiacum blue in the presence of reagents con- 

 taining peroxide, such as old turpentine. 



A sufficiently dilute solution of oxyhsemoglobin or arterial blood 

 shows a spectrum with two absorption-bands between the FRAUNHOFER 

 lines D and E (spectrum plate 1). The one band, a, which is narrower 

 but darker and sharper, lies on the line D; the other, broader, less defined 

 and less dark band, /?, lies at E. The middle of the first band corresponds 

 to a wave-length ^ = 579 and the second ^=542. On dilution the band 

 ft first disappears. By increased concentration 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. Besides these two bands we can also observe by the aid 

 of special appliances (L. LEWIN, MIETHE, and STENGER) the band 

 described by GAMGEE in the ultra-violet portion. This violet band,. 

 X =415, is of importance in the detection of very small quantities of blood. 

 While the two oxyhffimoglobin bands are still detectable in a dilution of 

 1 : 14,700 the violet band may be seen, according to LEWIN, MIETHE and 

 STENGER 1 in a dilution of 1 : 40,000. 



The observation of PIETTRE and VILA that so-called laky blood and oxyhsemo- 

 globin solutions in thick layers also show a third band in the red (A =-634) depends 

 in all probability, as also claimed by VILLB and DERRIEN, upon a partial forma- 

 tion of metha3moglobin which according to ARON 2 exists preformed in all blood- 



A great many methods have been proposed for the preparation of 

 oxyhsemoglobin crystals, but in their chief features they all agree with 

 the following one 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 allow- 

 ing the ether which is retained by the blood solution to evaporate in an 

 open dish in the air, cool the filtered blood solution to C., add while 

 stirring one-fourth vol. of alcohol also cooled, and allow to stand a few 

 days at 5 to 10 C. The crystals which separate may be repeatedly 

 recrystallized by dissolving in water of about 35 C., cooling, and adding 

 cooled alcohol as above. Lastly, they are washed with cooled water 



1 Gamgee, Zeitschr. f. Biol., 34; Lewin, Miethe and Stenger, Pfliiger's Arch., 118; 

 Lewin and Miethe, ibid., 121. 



2 Piettre and Vila, Compt. rend., 140; Ville and Derrien, ibid., 140; Aron, Biochem. 

 Zeitschr., 3. 



