88 PREPARATION AND STUDY OF HEMOGLOBIN CRYSTALS 



crystallizes with extraordinary rapidity. To the blood of a mouse taken 

 from the animal 20 hours after death he added a mixture of equal volumes 

 of alcohol and ether, and obtained, within a few minutes, numerous irreg- 

 ular six-sided plates and also rod-shaped crystals, occasionally in star- 

 shaped groups. From the blood of the dog he always obtained crystals 

 within 15 to 20 minutes after the addition of the mixture of alcohol and 

 ether. From the cat he obtained three-sided prisms, which in most cases 

 appeared a bright red, occasionally a bright yellow, and at times com- 

 pletely colorless. He also obtained crystals after the addition of water, 

 and also after putrefaction had set in. The blood of a hedgehog that had 

 been chloroformed 24 hours previously yielded crystals without treatment, 

 but the crystals were much better when a mixture of alcohol and ether 

 (1 : 4) had been added to the blood. Crystals of the lark he secured by the 

 addition of a mixture of alcohol and water (1:1). Crystals from the horn- 

 fish formed in the blood with or without the addition of water, and in the 

 same way he obtained similar crystals from the blood of the pike. The 

 blood of the herring he states crystallizes extraordinarily quickly, and the 

 crystals almost always appeared colorless and possessed a shimmer similar 

 to mother-of-pearl. From the blood of the raven he obtained crystals only 

 after the blood had stood for 8 days in a cool place, and by the addition of 

 chloroform and ether (1:3); but he failed to obtain crystals by the addi- 

 tion of distilled water, alcohol, gum solution, or sugar solution. The crystals 

 he describes as partly colored bright yellow, partly completely colorless. 

 Similar crystals were obtained from the pigeon by the addition of distilled 

 water. Bojanowski notes from his investigations that the crystals of dif- 

 ferent species have something specific and characteristic about them, so 

 that occasionally he could designate the species from which the crystals 

 were derived. 



The characteristic absorption spectrum of hemoglobin was discovered 

 by Hoppe (Archiv f. path. Anat. u. Physiologie, 1862, xxm, 446; Hoppe- 

 Seyler was known as Hoppe previous to 1864), who states his belief that 

 it is the same for the bloods of all vertebrates. He showed that hematin, 

 which until then had been almost universally regarded as the coloring 

 matter of the blood, is an abnormal constituent, and a product of decom- 

 position of hemoglobin. He identified hemoglobin with the blood crystals 

 described by Himefeld, Reichert, Funke, and others, and he showed that 

 while certain reagents were without effect on hemoglobin, others gave rise 

 to a decomposition into an albuminous substance and hematin. No differ- 

 ence was noted in the spectra of arterial and venous blood, which was 

 doubtless owing to the rapid oxidation of his preparations of venous blood, 

 as he did not know, until some time later, of the difference in the coloring 

 matter of arterial and venous blood and of the rapid oxidation of reduced 

 hemoglobin when exposed to the air. 



In Hoppe-Seyler's second contribution (Archiv f. path. Anat. u. Phy- 

 siologie, 1864, xxix, 233, 567; Centralblatt f. d. med. Wissensch., 1864, u, 

 April 16, 261, 817, 834) he proposed the terms "hemoglobin" and "hemato- 

 globin" to distinguish the coloring matter of the blood. This substance, he 



